Make pg_stripe_size a per-pool config

This makes sense for some SSDs like Intel D3-4510 because they don't
like overwrites of the same sector:

$ fio -direct=1 -rw=write -bs=4k -size=4k -loops=100000 -iodepth=1
  write: IOPS=3142, BW=12.3MiB/s (12.9MB/s)(97.9MiB/7977msec)

$ fio -direct=1 -rw=write -bs=4k -size=128k -loops=100000 -iodepth=1
  write: IOPS=20.8k, BW=81.4MiB/s (85.3MB/s)(543MiB/6675msec)

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "cpp-btree"]
+	path = cpp-btree
+	url = ../cpp-btree.git
+[submodule "json11"]
+	path = json11
+	url = ../json11.git

GPL-2.0.txt

@@ -0,0 +1,339 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
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+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
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+
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+that everyone understands that there is no warranty for this free
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+  The precise terms and conditions for copying, distribution and
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+
+                    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
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+language.  (Hereinafter, translation is included without limitation in
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+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
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+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
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+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
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+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
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+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
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+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
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+    part thereof, to be licensed as a whole at no charge to all third
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+
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+    when run, you must cause it, when started running for such
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+These requirements apply to the modified work as a whole.  If
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+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
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+
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+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
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+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
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+
+  10. If you wish to incorporate parts of the Program into other free
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+
+                            NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
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+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
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+POSSIBILITY OF SUCH DAMAGES.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.

Make-gen.pl

@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+use strict;
+
+my $deps = {};
+for my $line (split /\n/, `grep '^#include "' *.cpp *.h`)
+{
+    if ($line =~ /^([^:]+):\#include "([^"]+)"/s)
+    {
+        $deps->{$1}->{$2} = 1;
+    }
+}
+
+my $added;
+do
+{
+    $added = 0;
+    for my $file (keys %$deps)
+    {
+        for my $dep (keys %{$deps->{$file}})
+        {
+            if ($deps->{$dep})
+            {
+                for my $subdep (keys %{$deps->{$dep}})
+                {
+                    if (!$deps->{$file}->{$subdep})
+                    {
+                        $added = 1;
+                        $deps->{$file}->{$subdep} = 1;
+                    }
+                }
+            }
+        }
+    }
+} while ($added);
+
+for my $file (sort keys %$deps)
+{
+    if ($file =~ /\.cpp$/)
+    {
+        my $obj = $file;
+        $obj =~ s/\.cpp$/.o/s;
+        print "$obj: $file ".join(" ", sort keys %{$deps->{$file}})."\n";
+        print "\tg++ \$(CXXFLAGS) -c -o \$\@ \$\<\n";
+    }
+}

Makefile

@@ -1,66 +1,169 @@
 BLOCKSTORE_OBJS := allocator.o blockstore.o blockstore_impl.o blockstore_init.o blockstore_open.o blockstore_journal.o blockstore_read.o \
-	blockstore_write.o blockstore_sync.o blockstore_stable.o blockstore_rollback.o blockstore_flush.o crc32c.o ringloop.o timerfd_interval.o
+	blockstore_write.o blockstore_sync.o blockstore_stable.o blockstore_rollback.o blockstore_flush.o crc32c.o ringloop.o
 # -fsanitize=address
 CXXFLAGS := -g -O3 -Wall -Wno-sign-compare -Wno-comment -Wno-parentheses -Wno-pointer-arith -fPIC -fdiagnostics-color=always
-all: $(BLOCKSTORE_OBJS) libfio_blockstore.so osd libfio_sec_osd.so test_blockstore stub_osd stub_bench osd_test
+all: libfio_blockstore.so osd libfio_sec_osd.so libfio_cluster.so stub_osd stub_uring_osd stub_bench osd_test dump_journal qemu_driver.so nbd_proxy
 clean:
 	rm -f *.o
 
-crc32c.o: crc32c.c
+dump_journal: dump_journal.cpp crc32c.o blockstore_journal.h
+	g++ $(CXXFLAGS) -o $@ $< crc32c.o
+
+libblockstore.so: $(BLOCKSTORE_OBJS)
+	g++ $(CXXFLAGS) -o $@ -shared $(BLOCKSTORE_OBJS) -ltcmalloc_minimal -luring
+libfio_blockstore.so: ./libblockstore.so fio_engine.o json11.o
+	g++ $(CXXFLAGS) -shared -o $@ fio_engine.o json11.o ./libblockstore.so -ltcmalloc_minimal -luring
+
+OSD_OBJS := osd.o osd_secondary.o msgr_receive.o msgr_send.o osd_peering.o osd_flush.o osd_peering_pg.o \
+	osd_primary.o osd_primary_subops.o etcd_state_client.o messenger.o osd_cluster.o http_client.o osd_ops.o pg_states.o \
+	osd_rmw.o json11.o base64.o timerfd_manager.o epoll_manager.o
+osd: ./libblockstore.so osd_main.cpp osd.h osd_ops.h $(OSD_OBJS)
+	g++ $(CXXFLAGS) -o $@ osd_main.cpp $(OSD_OBJS) ./libblockstore.so -ltcmalloc_minimal -luring
+
+stub_osd: stub_osd.o rw_blocking.o
+	g++ $(CXXFLAGS) -o $@ stub_osd.o rw_blocking.o -ltcmalloc_minimal
+
+STUB_URING_OSD_OBJS := stub_uring_osd.o epoll_manager.o messenger.o msgr_send.o msgr_receive.o ringloop.o timerfd_manager.o json11.o
+stub_uring_osd: $(STUB_URING_OSD_OBJS)
+	g++ $(CXXFLAGS) -o $@ -ltcmalloc_minimal $(STUB_URING_OSD_OBJS) -luring
+stub_bench: stub_bench.cpp osd_ops.h rw_blocking.o
+	g++ $(CXXFLAGS) -o $@ stub_bench.cpp rw_blocking.o -ltcmalloc_minimal
+osd_test: osd_test.cpp osd_ops.h rw_blocking.o
+	g++ $(CXXFLAGS) -o $@ osd_test.cpp rw_blocking.o -ltcmalloc_minimal
+osd_peering_pg_test: osd_peering_pg_test.cpp osd_peering_pg.o
+	g++ $(CXXFLAGS) -o $@ $< osd_peering_pg.o -ltcmalloc_minimal
+
+libfio_sec_osd.so: fio_sec_osd.o rw_blocking.o
+	g++ $(CXXFLAGS) -ltcmalloc_minimal -shared -o $@ fio_sec_osd.o rw_blocking.o
+
+FIO_CLUSTER_OBJS := cluster_client.o epoll_manager.o etcd_state_client.o \
+	messenger.o msgr_send.o msgr_receive.o ringloop.o json11.o http_client.o osd_ops.o pg_states.o timerfd_manager.o base64.o
+libfio_cluster.so: fio_cluster.o $(FIO_CLUSTER_OBJS)
+	g++ $(CXXFLAGS) -ltcmalloc_minimal -shared -o $@ $< $(FIO_CLUSTER_OBJS) -luring
+
+nbd_proxy: nbd_proxy.o $(FIO_CLUSTER_OBJS)
+	g++ $(CXXFLAGS) -ltcmalloc_minimal -o $@ $< $(FIO_CLUSTER_OBJS) -luring
+
+qemu_driver.o: qemu_driver.c qemu_proxy.h
+	gcc -I qemu/b/qemu `pkg-config glib-2.0 --cflags` \
+		-I qemu/include $(CXXFLAGS) -c -o $@ $<
+
+qemu_driver.so: qemu_driver.o qemu_proxy.o $(FIO_CLUSTER_OBJS)
+	g++ $(CXXFLAGS) -ltcmalloc_minimal -shared -o $@ $< $(FIO_CLUSTER_OBJS) qemu_driver.o qemu_proxy.o -luring
+
+test_blockstore: ./libblockstore.so test_blockstore.cpp timerfd_interval.o
+	g++ $(CXXFLAGS) -o test_blockstore test_blockstore.cpp timerfd_interval.o ./libblockstore.so -ltcmalloc_minimal -luring
+test: test.cpp osd_peering_pg.o
+	g++ $(CXXFLAGS) -o test test.cpp osd_peering_pg.o -luring -lm
+test_allocator: test_allocator.cpp allocator.o
+	g++ $(CXXFLAGS) -o test_allocator test_allocator.cpp allocator.o
+
+crc32c.o: crc32c.c crc32c.h
 	g++ $(CXXFLAGS) -c -o $@ $<
 json11.o: json11/json11.cpp
 	g++ $(CXXFLAGS) -c -o json11.o json11/json11.cpp
+
+# Autogenerated
+
 allocator.o: allocator.cpp allocator.h
 	g++ $(CXXFLAGS) -c -o $@ $<
+base64.o: base64.cpp base64.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore.o: blockstore.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_flush.o: blockstore_flush.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_impl.o: blockstore_impl.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_init.o: blockstore_init.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_journal.o: blockstore_journal.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_open.o: blockstore_open.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_read.o: blockstore_read.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_rollback.o: blockstore_rollback.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_stable.o: blockstore_stable.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_sync.o: blockstore_sync.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+blockstore_write.o: blockstore_write.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+cluster_client.o: cluster_client.cpp cluster_client.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+dump_journal.o: dump_journal.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+epoll_manager.o: epoll_manager.cpp epoll_manager.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+etcd_state_client.o: etcd_state_client.cpp base64.h etcd_state_client.h http_client.h json11/json11.hpp object_id.h osd_id.h osd_ops.h pg_states.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+fio_cluster.o: fio_cluster.cpp cluster_client.h epoll_manager.h etcd_state_client.h fio/fio.h fio/optgroup.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+fio_engine.o: fio_engine.cpp blockstore.h fio/fio.h fio/optgroup.h json11/json11.hpp object_id.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+fio_sec_osd.o: fio_sec_osd.cpp fio/fio.h fio/optgroup.h object_id.h osd_id.h osd_ops.h rw_blocking.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+http_client.o: http_client.cpp http_client.h json11/json11.hpp timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+messenger.o: messenger.cpp json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+msgr_receive.o: msgr_receive.cpp json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+msgr_send.o: msgr_send.cpp json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+nbd_proxy.o: nbd_proxy.cpp cluster_client.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd.o: osd.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_cluster.o: osd_cluster.cpp base64.h blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_flush.o: osd_flush.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_main.o: osd_main.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_ops.o: osd_ops.cpp object_id.h osd_id.h osd_ops.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_peering.o: osd_peering.cpp base64.h blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_peering_pg.o: osd_peering_pg.cpp cpp-btree/btree_map.h object_id.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_peering_pg_test.o: osd_peering_pg_test.cpp cpp-btree/btree_map.h object_id.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_primary.o: osd_primary.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h osd_primary.h osd_rmw.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_primary_subops.o: osd_primary_subops.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h osd_primary.h osd_rmw.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_rmw.o: osd_rmw.cpp malloc_or_die.h object_id.h osd_id.h osd_rmw.h xor.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_rmw_test.o: osd_rmw_test.cpp malloc_or_die.h object_id.h osd_id.h osd_rmw.cpp osd_rmw.h test_pattern.h xor.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_secondary.o: osd_secondary.cpp blockstore.h cpp-btree/btree_map.h epoll_manager.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+osd_test.o: osd_test.cpp object_id.h osd_id.h osd_ops.h rw_blocking.h test_pattern.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+pg_states.o: pg_states.cpp pg_states.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+qemu_proxy.o: qemu_proxy.cpp cluster_client.h etcd_state_client.h http_client.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h qemu_proxy.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
 ringloop.o: ringloop.cpp ringloop.h
 	g++ $(CXXFLAGS) -c -o $@ $<
-timerfd_interval.o: timerfd_interval.cpp timerfd_interval.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-
-%.o: %.cpp allocator.h blockstore_flush.h blockstore.h blockstore_impl.h blockstore_init.h blockstore_journal.h crc32c.h ringloop.h timerfd_interval.h object_id.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-
-libblockstore.so: $(BLOCKSTORE_OBJS)
-	g++ $(CXXFLAGS) -o libblockstore.so -shared $(BLOCKSTORE_OBJS) -ltcmalloc_minimal -luring
-libfio_blockstore.so: ./libblockstore.so fio_engine.cpp json11.o
-	g++ $(CXXFLAGS) -shared -o libfio_blockstore.so fio_engine.cpp json11.o ./libblockstore.so -ltcmalloc_minimal -luring
-
-OSD_OBJS := osd.o osd_secondary.o osd_receive.o osd_send.o osd_peering.o osd_peering_pg.o osd_primary.o osd_rmw.o json11.o timerfd_interval.o
-osd_secondary.o: osd_secondary.cpp osd.h osd_ops.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_receive.o: osd_receive.cpp osd.h osd_ops.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_send.o: osd_send.cpp osd.h osd_ops.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_peering.o: osd_peering.cpp osd.h osd_ops.h osd_peering_pg.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_peering_pg.o: osd_peering_pg.cpp object_id.h osd_peering_pg.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_rmw.o: osd_rmw.cpp osd_rmw.h xor.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd_rmw_test: osd_rmw_test.cpp osd_rmw.cpp osd_rmw.h xor.h
-	g++ $(CXXFLAGS) -o $@ $<
-osd_primary.o: osd_primary.cpp osd.h osd_ops.h osd_peering_pg.h xor.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd.o: osd.cpp osd.h osd_ops.h osd_peering_pg.h ringloop.h
-	g++ $(CXXFLAGS) -c -o $@ $<
-osd: ./libblockstore.so osd_main.cpp osd.h osd_ops.h $(OSD_OBJS)
-	g++ $(CXXFLAGS) -o osd osd_main.cpp $(OSD_OBJS) ./libblockstore.so -ltcmalloc_minimal -luring
-stub_osd: stub_osd.cpp osd_ops.h rw_blocking.o
-	g++ $(CXXFLAGS) -o stub_osd stub_osd.cpp rw_blocking.o -ltcmalloc_minimal
-stub_bench: stub_bench.cpp osd_ops.h rw_blocking.o
-	g++ $(CXXFLAGS) -o stub_bench stub_bench.cpp rw_blocking.o -ltcmalloc_minimal
 rw_blocking.o: rw_blocking.cpp rw_blocking.h
 	g++ $(CXXFLAGS) -c -o $@ $<
-osd_test: osd_test.cpp osd_ops.h rw_blocking.o
-	g++ $(CXXFLAGS) -o osd_test osd_test.cpp rw_blocking.o -ltcmalloc_minimal
-
-libfio_sec_osd.so: fio_sec_osd.cpp osd_ops.h rw_blocking.o
-	g++ $(CXXFLAGS) -ltcmalloc_minimal -shared -o libfio_sec_osd.so fio_sec_osd.cpp rw_blocking.o -luring
-
-test_blockstore: ./libblockstore.so test_blockstore.cpp
-	g++ $(CXXFLAGS) -o test_blockstore test_blockstore.cpp ./libblockstore.so -ltcmalloc_minimal -luring
-test: test.cpp osd_peering_pg.o
-	g++ $(CXXFLAGS) -o test test.cpp osd_peering_pg.o -luring
-test_allocator: test_allocator.cpp allocator.o
-	g++ $(CXXFLAGS) -o test_allocator test_allocator.cpp allocator.o
+stub_bench.o: stub_bench.cpp object_id.h osd_id.h osd_ops.h rw_blocking.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+stub_osd.o: stub_osd.cpp object_id.h osd_id.h osd_ops.h rw_blocking.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+stub_uring_osd.o: stub_uring_osd.cpp epoll_manager.h json11/json11.hpp malloc_or_die.h messenger.h object_id.h osd_id.h osd_ops.h ringloop.h timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+test.o: test.cpp allocator.h blockstore.h blockstore_flush.h blockstore_impl.h blockstore_init.h blockstore_journal.h cpp-btree/btree_map.h crc32c.h malloc_or_die.h object_id.h osd_id.h osd_ops.h osd_peering_pg.h pg_states.h ringloop.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+test_allocator.o: test_allocator.cpp allocator.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+test_blockstore.o: test_blockstore.cpp blockstore.h object_id.h ringloop.h timerfd_interval.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+timerfd_interval.o: timerfd_interval.cpp ringloop.h timerfd_interval.h
+	g++ $(CXXFLAGS) -c -o $@ $<
+timerfd_manager.o: timerfd_manager.cpp timerfd_manager.h
+	g++ $(CXXFLAGS) -c -o $@ $<

README.md

@@ -0,0 +1,387 @@
+## Vitastor
+
+## The Idea
+
+Make Software-Defined Block Storage Great Again.
+
+Vitastor is a small, simple and fast clustered block storage (storage for VM drives),
+architecturally similar to Ceph which means strong consistency, primary-replication, symmetric
+clustering and automatic data distribution over any number of drives of any size
+with configurable redundancy (replication or erasure codes/XOR).
+
+## Features
+
+Vitastor is currently a pre-release, a lot of features are missing and you can still expect
+breaking changes in the future. However, the following is implemented:
+
+- Basic part: highly-available block storage with symmetric clustering and no SPOF
+- Performance ;-D
+- Two redundancy schemes: Replication and XOR n+1 (simplest case of EC)
+- Configuration via simple JSON data structures in etcd
+- Automatic data distribution over OSDs, with support for:
+  - Mathematical optimization for better uniformity and less data movement
+  - Multiple pools
+  - Placement tree
+  - Configurable failure domains
+- Recovery of degraded blocks
+- Rebalancing (data movement between OSDs)
+- Lazy fsync support
+- I/O statistics reporting to etcd
+- Generic user-space client library
+- QEMU driver (built out-of-tree)
+- Loadable fio engine for benchmarks (also built out-of-tree)
+- NBD proxy for kernel mounts
+
+## Roadmap
+
+- Packaging for Debian and, probably, CentOS too
+- OSD creation tool (OSDs currently have to be created by hand)
+- Inode deletion tool (currently you can't delete anything :))
+- Other administrative tools
+- Per-inode I/O and space usage statistics
+- jerasure EC support with any number of data and parity drives in a group
+- Parallel usage of multiple network interfaces
+- Proxmox and OpenNebula plugins
+- iSCSI proxy
+- Inode metadata storage in etcd
+- Snapshots and copy-on-write image clones
+- Operation timeouts and better failure detection
+- Checksums
+- SSD+HDD optimizations, possibly including tiered storage and soft journal flushes
+- RDMA and NVDIMM support
+- Compression (possibly)
+- Read caching using system page cache (possibly)
+
+## Architecture
+
+Similarities:
+
+- Just like Ceph, Vitastor has Pools, PGs, OSDs, Monitors, Failure Domains, Placement Tree.
+- Just like Ceph, Vitastor is transactional (even though there's a "lazy fsync mode" which
+  doesn't implicitly flush every operation to disks).
+- OSDs also have journal and metadata and they can also be put on separate drives.
+- Just like in Ceph, client library attempts to recover from any cluster failure so
+  you can basically reboot the whole cluster and only pause, but not crash, your clients
+  (I consider this a bug if the client crashes in that case).
+
+Some basic terms for people not familiar with Ceph:
+
+- OSD (Object Storage Daemon) is a process that stores data and serves read/write requests.
+- PG (Placement Group) is a container for data that (normally) shares the same replicas.
+- Pool is a container for data that has the same redundancy scheme and placement rules.
+- Monitor is a separate daemon that watches cluster state and handles failures.
+- Failure Domain is a group of OSDs that you allow to fail. It's "host" by default.
+- Placement Tree groups OSDs in a hierarchy to later split them into Failure Domains.
+
+Architectural differences from Ceph:
+
+- Vitastor's primary focus is on SSDs. Proper SSD+HDD optimizations may be added in the future, though.
+- Vitastor OSD is (and will always be) single-threaded. If you want to dedicate more than 1 core
+  per drive you should run multiple OSDs each on a different partition of the drive.
+  Vitastor isn't CPU-hungry though (as opposed to Ceph), so 1 core is sufficient in a lot of cases.
+- Metadata and journal are always kept in memory. Metadata size depends linearly on drive capacity
+  and data store block size which is 128 KB by default. With 128 KB blocks, metadata should occupy
+  around 512 MB per 1 TB (which is still less than Ceph wants). Journal doesn't have to be big,
+  the example test below was conducted with only 16 MB journal. A big journal is probably even
+  harmful as dirty write metadata also take some memory.
+- Vitastor storage layer doesn't have internal copy-on-write or redirect-write. I know that maybe
+  it's possible to create a good copy-on-write storage, but it's much harder and makes performance
+  less deterministic, so CoW isn't used in Vitastor.
+- The basic layer of Vitastor is block storage with fixed-size blocks, not object storage with
+  rich semantics like in Ceph (RADOS).
+- There's a "lazy fsync" mode which allows to batch writes before flushing them to the disk.
+  This allows to use Vitastor with desktop SSDs, but still lowers performance due to additional
+  network roundtrips, so use server SSDs with capacitor-based power loss protection
+  ("Advanced Power Loss Protection") for best performance.
+- PGs are ephemeral. This means that they aren't stored on data disks and only exist in memory
+  while OSDs are running.
+- Recovery process is per-object (per-block), not per-PG. Also there are no PGLOGs.
+- Monitors don't store data. Cluster configuration and state is stored in etcd in simple human-readable
+  JSON structures. Monitors only watch cluster state and handle data movement.
+  Thus Vitastor's Monitor isn't a critical component of the system and is more similar to Ceph's Manager.
+  Vitastor's Monitor is implemented in node.js.
+- PG distribution isn't based on consistent hashes. All PG mappings are stored in etcd.
+  Rebalancing PGs between OSDs is done by mathematical optimization - data distribution problem
+  is reduced to a linear programming problem and solved by lp_solve. This allows for almost
+  perfect (96-99% uniformity compared to Ceph's 80-90%) data distribution in most cases, ability
+  to map PGs by hand without breaking rebalancing logic, reduced OSD peer-to-peer communication
+  (on average, OSDs have fewer peers) and less data movement. It also probably has a drawback -
+  this method may fail in very large clusters, but up to several hundreds of OSDs it's perfectly fine.
+  It's also easy to add consistent hashes in the future if something proves their necessity.
+- There's no separate CRUSH layer. You select pool redundancy scheme, placement root, failure domain
+  and so on directly in pool configuration.
+
+## Understanding Storage Performance
+
+The most important thing for fast storage is latency, not parallel iops.
+
+The best possible latency is achieved with one thread and queue depth of 1 which basically means
+"client load as low as possible". In this case IOPS = 1/latency, and this number doesn't
+scale with number of servers, drives, server processes or threads and so on.
+Single-threaded IOPS and latency numbers only depend on *how fast a single daemon is*.
+
+Why is it important? It's important because some of the applications *can't* use
+queue depth greater than 1 because their task isn't parallelizable. A notable example
+is any ACID DBMS because all of them write their WALs sequentially with fsync()s.
+
+fsync, by the way, is another important thing often missing in benchmarks. The point is
+that drives have cache buffers and don't guarantee that your data is actually persisted
+until you call fsync() which is translated to a FLUSH CACHE command by the OS.
+
+Desktop SSDs are very fast without fsync - NVMes, for example, can process ~80000 write
+operations per second with queue depth of 1 without fsync - but they're really slow with
+fsync because they have to actually write data to flash chips when you call fsync. Typical
+number is around 1000-2000 iops with fsync.
+
+Server SSDs often have supercapacitors that act as a built-in UPS and allow the drive
+to flush its DRAM cache to the persistent flash storage when a power loss occurs.
+This makes them perform equally well with and without fsync. This feature is called
+"Advanced Power Loss Protection" by Intel; other vendors either call it similarly
+or directly as "Full Capacitor-Based Power Loss Protection".
+
+All software-defined storages that I currently know are slow in terms of latency.
+Notable examples are Ceph and internal SDSes used by cloud providers like Amazon, Google,
+Yandex and so on. They're all slow and can only reach ~0.3ms read and ~0.6ms 4 KB write latency
+with best-in-slot hardware.
+
+And that's in the SSD era when you can buy an SSD that has ~0.04ms latency for 100 $.
+
+I use the following 6 commands with small variations to benchmark any storage:
+
+- Linear write:
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4M -iodepth=32 -rw=write -runtime=60 -filename=/dev/sdX`
+- Linear read:
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4M -iodepth=32 -rw=read -runtime=60 -filename=/dev/sdX`
+- Random write latency (this hurts storages the most):
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=1 -fsync=1 -rw=randwrite -runtime=60 -filename=/dev/sdX`
+- Random read latency:
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=1 -rw=randread -runtime=60 -filename=/dev/sdX`
+- Parallel write iops (use numjobs if a single CPU core is insufficient to saturate the load):
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=128 [-numjobs=4 -group_reporting] -rw=randwrite -runtime=60 -filename=/dev/sdX`
+- Parallel read iops (use numjobs if a single CPU core is insufficient to saturate the load):
+  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=128 [-numjobs=4 -group_reporting] -rw=randread -runtime=60 -filename=/dev/sdX`
+
+## Vitastor's Theoretical Maximum Random Access Performance
+
+Replicated setups:
+- Single-threaded (T1Q1) read latency: 1 network roundtrip + 1 disk read.
+- Single-threaded write+fsync latency:
+  - With immediate commit: 2 network roundtrips + 1 disk write.
+  - With lazy commit: 4 network roundtrips + 1 disk write + 1 disk flush.
+- Saturated parallel read iops: min(network bandwidth, sum(disk read iops)).
+- Saturated parallel write iops: min(network bandwidth, sum(disk write iops / number of replicas / write amplification)).
+
+EC/XOR setups:
+- Single-threaded (T1Q1) read latency: 1.5 network roundtrips + 1 disk read.
+- Single-threaded write+fsync latency:
+  - With immediate commit: 3.5 network roundtrips + 1 disk read + 2 disk writes.
+  - With lazy commit: 5.5 network roundtrips + 1 disk read + 2 disk writes + 2 disk fsyncs.
+  - 0.5 in actually (k-1)/k which means that an additional roundtrip doesn't happen when
+    the read sub-operation can be served locally.
+- Saturated parallel read iops: min(network bandwidth, sum(disk read iops)).
+- Saturated parallel write iops: min(network bandwidth, sum(disk write iops * number of data drives / (number of data + parity drives) / write amplification)).
+  In fact, you should put disk write iops under the condition of ~10% reads / ~90% writes in this formula.
+
+Write amplification for 4 KB blocks is usually 3-5 in Vitastor:
+1. Journal block write
+2. Journal data write
+3. Metadata block write
+4. Another journal block write for EC/XOR setups
+5. Data block write
+
+If you manage to get an SSD which handles 512 byte blocks well (Optane?) you may
+lower 1, 3 and 4 to 512 bytes (1/8 of data size) and get WA as low as 2.375.
+
+Lazy fsync also reduces WA for parallel workloads because journal blocks are only
+written when they fill up or fsync is requested.
+
+## Example Comparison with Ceph
+
+Hardware configuration: 4 nodes, each with:
+- 6x SATA SSD Intel D3-4510 3.84 TB
+- 2x Xeon Gold 6242 (16 cores @ 2.8 GHz)
+- 384 GB RAM
+- 1x 25 GbE network interface (Mellanox ConnectX-4 LX), connected to a Juniper QFX5200 switch
+
+CPU powersaving was disabled. Both Vitastor and Ceph were configured with 2 OSDs per 1 SSD.
+
+All of the results below apply to 4 KB blocks.
+
+Raw drive performance:
+- T1Q1 write ~27000 iops (~0.037ms latency)
+- T1Q1 read ~9800 iops (~0.101ms latency)
+- T1Q32 write ~60000 iops
+- T1Q32 read ~81700 iops
+
+Ceph 15.2.4 (Bluestore):
+- T1Q1 write ~1000 iops (~1ms latency)
+- T1Q1 read ~1750 iops (~0.57ms latency)
+- T8Q64 write ~100000 iops, total CPU usage by OSDs about 40 virtual cores on each node
+- T8Q64 read ~480000 iops, total CPU usage by OSDs about 40 virtual cores on each node
+
+T8Q64 tests were conducted over 8 400GB RBD images from all hosts (every host was running 2 instances of fio).
+This is because Ceph has performance penalties related to running multiple clients over a single RBD image.
+
+cephx_sign_messages was set to false during tests, RocksDB and Bluestore settings were left at defaults.
+
+In fact, not that bad for Ceph. These servers are an example of well-balanced Ceph nodes.
+However, CPU usage and I/O latency were through the roof, as usual.
+
+Vitastor:
+- T1Q1 write: 7087 iops (0.14ms latency)
+- T1Q1 read: 6838 iops (0.145ms latency)
+- T2Q64 write: 162000 iops, total CPU usage by OSDs about 3 virtual cores on each node
+- T8Q64 read: 895000 iops, total CPU usage by OSDs about 4 virtual cores on each node
+
+T8Q64 read test was conducted over 1 larger inode (3.2T) from all hosts (every host was running 2 instances of fio).
+Vitastor has no performance penalties related to running multiple clients over a single inode.
+If conducted from one node with all primary OSDs moved to other nodes the result was slightly lower (689000 iops),
+this is because all operations resulted in network roundtrips between the client and the primary OSD.
+When fio was colocated with OSDs (like in Ceph benchmarks above), 1/4 of the read workload actually
+used the loopback network.
+
+Vitastor was configured with: `--disable_data_fsync true --immediate_commit all --flusher_count 8
+  --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096
+  --journal_no_same_sector_overwrites true --journal_sector_buffer_count 1024
+  --journal_size 16777216`.
+
+### NBD
+
+NBD is currently required to mount Vitastor via kernel, but it imposes additional overhead
+due to additional copying between the kernel and userspace. This mostly hurts linear
+bandwidth, not iops.
+
+Vitastor with single-thread NBD on the same hardware:
+- T1Q1 write: 6000 iops (0.166ms latency)
+- T1Q1 read: 5518 iops (0.18ms latency)
+- T1Q128 write: 94400 iops
+- T1Q128 read: 103000 iops
+- Linear write (4M T1Q128): 1266 MB/s (compared to 2600 MB/s via fio)
+- Linear read (4M T1Q128): 975 MB/s (compared to 1400 MB/s via fio)
+
+## Building
+
+- Install Linux kernel 5.4 or newer for io_uring support.
+- Install liburing 0.4 or newer and its headers.
+- Install lp_solve.
+- Install etcd.
+- Install node.js 12 or newer.
+- Install gcc and g++ 9.x.
+- Clone https://yourcmc.ru/git/vitalif/vitastor/ with submodules.
+- Install QEMU 4.x or 5.x, get its source, begin to build it, stop the build and copy headers:
+   - `<qemu>/include` &rarr; `<vitastor>/qemu/include`
+   - Debian:
+      * Use qemu packages from the main repository
+      * `<qemu>/b/qemu/config-host.h` &rarr; `<vitastor>/qemu/b/qemu/config-host.h`
+      * `<qemu>/b/qemu/qapi` &rarr; `<vitastor>/qemu/b/qemu/qapi`
+   - CentOS 8:
+      * Use qemu packages from the Advanced-Virtualization repository. To enable it, run
+        `yum install centos-release-advanced-virtualization.noarch` and then `yum install qemu`
+      * `<qemu>/config-host.h` &rarr; `<vitastor>/qemu/b/qemu/config-host.h`
+      * `<qemu>/qapi` &rarr; `<vitastor>/qemu/b/qemu/qapi`
+   - `config-host.h` and `qapi` are required because they contain generated headers
+- Install fio 3.16, get its source and symlink it into `<vitastor>/fio`. It doesn't currently
+  build with fio 3.20 or newer due to the conflicts between g++ and gcc's atomics. This will
+  be fixed in the future.
+- Build Vitastor with `make -j8`.
+- Copy binaries somewhere.
+
+## Running
+
+Please note that startup procedure isn't currently simple - you specify configuration
+and calculate disk offsets almost by hand. This will be fixed in near future.
+
+- Get some SATA or NVMe SSDs with capacitors (server-grade drives). You can use desktop SSDs
+  with lazy fsync, but prepare for inferior single-thread latency.
+- Get a fast network (at least 10 Gbit/s).
+- Disable CPU powersaving: `cpupower idle-set -D 0 && cpupower frequency-set -g performance`.
+- Install etcd with `--max-txn-ops=100000 --auto-compaction-retention=10 --auto-compaction-mode=revision` options.
+- Create global configuration in etcd: `etcdctl put /vitastor/config/global '{"immediate_commit":"all"}'`
+  (if all your drives have capacitors).
+- Create pool configuration in etcd: `etcdctl put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":256,"failure_domain":"host"}}'`.
+- Calculate offsets for your drives with `node ./mon/simple-offsets.js /dev/sdX`.
+- Make systemd units for your OSDs. Look at `./mon/make-units.sh` for example.
+  Notable configuration variables from the example:
+  - `disable_data_fsync 1` - only safe with server-grade drives with capacitors.
+  - `immediate_commit all` - use this if all your drives are server-grade.
+  - `disable_device_lock 1` - only required if you run multiple OSDs on one block device.
+  - `flusher_count 16` - flusher is a micro-thread that removes old data from the journal.
+    More flushers mean more aggressive journal flushing which allows for more throughput
+    but slightly hurts latency under less load. Flushing will probably be improved in the future
+    because currently high queue depths sometimes lead to performance degradation.
+  - `disk_alignment`, `journal_block_size`, `meta_block_size` should be set to the internal
+    block size of your SSDs which is 4096 on most drives.
+  - `journal_no_same_sector_overwrites true` prevents multiple overwrites of the same journal sector.
+    Some SSDs (like Intel D3-4510) don't like such overwrites so they benefit from this setting.
+    When this setting is set, it is also required to raise `journal_sector_buffer_count` setting,
+    which is the number of dirty journal sectors that may be written to at the same time.
+- `systemctl start vitastor.target` everywhere.
+- Start any number of monitors: `cd mon; node mon-main.js --etcd_url 'http://10.115.0.10:2379,http://10.115.0.11:2379,http://10.115.0.12:2379,http://10.115.0.13:2379' --etcd_prefix '/vitastor' --etcd_start_timeout 5`.
+- At this point, one of the monitors will configure PGs and OSDs will start them.
+- You can check PG states with `etcdctl get --prefix /vitastor/pg/state`. All PGs should become 'active'.
+- Run tests with (for example): `fio -thread -ioengine=./libfio_cluster.so -name=test -bs=4M -direct=1 -iodepth=16 -rw=write -etcd=10.115.0.10:2379/v3 -pool=1 -inode=1 -size=400G`.
+- Upload VM disk image with qemu-img (for example):
+  ```
+  LD_PRELOAD=./qemu_driver.so qemu-img convert -f qcow2 debian10.qcow2 -p
+    -O raw 'vitastor:etcd_host=10.115.0.10\:2379/v3:pool=1:inode=1:size=2147483648'
+  ```
+- Run QEMU with (for example):
+  ```
+  LD_PRELOAD=./qemu_driver.so qemu-system-x86_64 -enable-kvm -m 1024
+    -drive 'file=vitastor:etcd_host=10.115.0.10\:2379/v3:pool=1:inode=1:size=2147483648',format=raw,if=none,id=drive-virtio-disk0,cache=none
+    -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,write-cache=off,physical_block_size=4096,logical_block_size=512
+    -vnc 0.0.0.0:0
+  ```
+
+## Known Problems
+
+- OSDs may currently crash with "can't get SQE, will fall out of sync with EPOLLET"
+  if you try to load them with very long iodepths because io_uring queue (ring) is limited
+  and OSDs don't check if it fills up.
+- Object deletion requests may currently lead to unfound objects on crashes because
+  proper handling of deletions in a cluster requires a "three-phase cleanup process"
+  and it's currently not implemented. In fact, even though deletion requests are
+  implemented, there's no user tool to delete anything from the cluster yet :).
+  Of course I'll create such tool, but its first implementation will be vulnerable to this issue.
+  It's not a big deal though, because you'll be able to just repeat the deletion request
+  in this case.
+
+## Implementation Principles
+
+- I like simple and stupid solutions, so expect Vitastor to stay simple.
+- I also like reinventing the wheel to some extent, like writing my own HTTP client
+  for etcd interaction instead of using prebuilt libraries, because in this case
+  I'm confident about what my code does and what it doesn't do.
+- I don't care about C++ "best practices" like RAII or proper inheritance or usage of
+  smart pointers or whatever and I don't intend to change my mind, so if you're here
+  looking for ideal reference C++ code, this probably isn't the right place.
+- I like node.js better than any other dynamically-typed language interpreter
+  because it's faster than any other interpreter in the world, has neutral C-like
+  syntax and built-in event loop. That's why Monitor is implemented in node.js.
+
+## Author and License
+
+Copyright (c) Vitaliy Filippov (vitalif [at] yourcmc.ru), 2019+
+
+You can also find me in the Russian Telegram Ceph chat: https://t.me/ceph_ru
+
+All server-side code (OSD, Monitor and so on) is licensed under the terms of
+Vitastor Network Public License 1.0 (VNPL 1.0), a copyleft license based on
+GNU GPLv3.0 with the additional "Network Interaction" clause which requires
+opensourcing all programs directly or indirectly interacting with Vitastor
+through a computer network ("Proxy Programs"). Proxy Programs may be made public
+not only under the terms of the same license, but also under the terms of any
+GPL-Compatible Free Software License, as listed by the Free Software Foundation.
+This is a stricter copyleft license than the Affero GPL.
+
+Basically, you can't use the software in a proprietary environment to provide
+its functionality to users without opensourcing all intermediary components
+standing between the user and Vitastor or purchasing a commercial license
+from the author 😀.
+
+Client libraries (cluster_client and so on) are dual-licensed under the same
+VNPL 1.0 and also GNU GPL 2.0 or later to allow for compatibility with GPLed
+software like QEMU and fio.
+
+You can find the full text of VNPL-1.0 in the file [VNPL-1.0.txt](VNPL-1.0.txt).
+GPL 2.0 is also included in this repository as [GPL-2.0.txt](GPL-2.0.txt).

VNPL-1.0.txt

@@ -0,0 +1,645 @@
+                     VITASTOR NETWORK PUBLIC LICENSE
+                       Version 1, 17 September 2020
+
+ Copyright (C) 2020 Vitaliy Filippov <vitalif@yourcmc.ru>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The Vitastor Network Public License is a free, copyleft license for
+software and other kinds of works, specifically designed to ensure
+cooperation with the community in the case of network server software.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+GNU General Public Licenses and Vitastor Network Public License are
+intended to guarantee your freedom to share and change all versions
+of a program--to make sure it remains free software for all its users.
+
+  When we speak of free software, we are referring to freedom, not
+price.  GNU General Public Licenses and Vitastor Network Public License
+are designed to make sure that you have the freedom to distribute copies
+of free software (and charge for them if you wish), that you receive
+source code or can get it if you want it, that you can change the software
+or use pieces of it in new free programs, and that you know you can do these
+things.
+
+  Developers that use GNU General Public Licenses and Vitastor
+Network Public License protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer
+you this License which gives you legal permission to copy, distribute
+and/or modify the software.
+
+  A secondary benefit of defending all users' freedom is that
+improvements made in alternate versions of the program, if they
+receive widespread use, become available for other developers to
+incorporate.  Many developers of free software are heartened and
+encouraged by the resulting cooperation.  However, in the case of
+software used on network servers, this result may fail to come about.
+The GNU General Public License permits making a modified version and
+letting the public access it on a server without ever releasing its
+source code to the public. Even the GNU Affero General Public License
+permits running a modified version in a closed environment where
+public users only interact with it through a closed-source proxy, again,
+without making the program and the proxy available to the public
+for free.
+
+  The Vitastor Network Public License is designed specifically to
+ensure that, in such cases, the modified program and the proxy stays
+available to the community. It requires the operator of a network server to
+provide the source code of the original program and all other programs
+communicating with it running there to the users of that server.
+Therefore, public use of a modified version, on a server accessible
+directly or indirectly to the public, gives the public access to the source
+code of the modified version.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
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+
+  "This License" refers to version 1 of the Vitastor Network Public License.
+
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+
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+
+  12. No Surrender of Others' Freedom.
+
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+
+  13. Remote Network Interaction.
+
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+  14. Revised Versions of this License.
+
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+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
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+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
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+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
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+    it under the terms of the Vitastor Network Public License as published by
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+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
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+Also add information on how to contact you by electronic and paper mail.
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+  If your software can interact with users remotely through a computer
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+solutions will be better for different programs; see section 13 for the
+specific requirements.

allocator.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <stdexcept>
 #include "allocator.h"
 

allocator.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include <stdint.h>

base64.cpp

@@ -0,0 +1,55 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include "base64.h"
+
+std::string base64_encode(const std::string &in)
+{
+    std::string out;
+    unsigned val = 0;
+    int valb = -6;
+    for (unsigned char c: in)
+    {
+        val = (val << 8) + c;
+        valb += 8;
+        while (valb >= 0)
+        {
+            out.push_back("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[(val>>valb) & 0x3F]);
+            valb -= 6;
+        }
+    }
+    if (valb > -6)
+        out.push_back("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[((val<<8)>>(valb+8)) & 0x3F]);
+    while (out.size() % 4)
+        out.push_back('=');
+    return out;
+}
+
+static char T[256] = { 0 };
+
+std::string base64_decode(const std::string &in)
+{
+    std::string out;
+    if (T[0] == 0)
+    {
+        for (int i = 0; i < 256; i++)
+            T[i] = -1;
+        for (int i = 0; i < 64; i++)
+            T[(unsigned char)("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[i])] = i;
+    }
+    unsigned val = 0;
+    int valb = -8;
+    for (unsigned char c: in)
+    {
+        if (T[c] == -1)
+            break;
+        val = (val<<6) + T[c];
+        valb += 6;
+        if (valb >= 0)
+        {
+            out.push_back(char((val >> valb) & 0xFF));
+            valb -= 8;
+        }
+    }
+    return out;
+}

base64.h

@@ -0,0 +1,8 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#pragma once
+#include <string>
+
+std::string base64_encode(const std::string &in);
+std::string base64_decode(const std::string &in);

blockstore.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 blockstore_t::blockstore_t(blockstore_config_t & config, ring_loop_t *ringloop)
@@ -55,6 +58,11 @@ uint64_t blockstore_t::get_block_count()
     return impl->get_block_count();
 }
 
+uint64_t blockstore_t::get_free_block_count()
+{
+    return impl->get_free_block_count();
+}
+
 uint32_t blockstore_t::get_disk_alignment()
 {
     return impl->get_disk_alignment();

blockstore.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #ifndef _LARGEFILE64_SOURCE
@@ -15,7 +18,9 @@
 
 // Memory alignment for direct I/O (usually 512 bytes)
 // All other alignments must be a multiple of this one
+#ifndef MEM_ALIGNMENT
 #define MEM_ALIGNMENT 512
+#endif
 
 // Default block size is 128 KB, current allowed range is 4K - 128M
 #define DEFAULT_ORDER 17
@@ -25,13 +30,14 @@
 #define BS_OP_MIN 1
 #define BS_OP_READ 1
 #define BS_OP_WRITE 2
-#define BS_OP_SYNC 3
-#define BS_OP_STABLE 4
-#define BS_OP_DELETE 5
-#define BS_OP_LIST 6
-#define BS_OP_ROLLBACK 7
-#define BS_OP_SYNC_STAB_ALL 8
-#define BS_OP_MAX 8
+#define BS_OP_WRITE_STABLE 3
+#define BS_OP_SYNC 4
+#define BS_OP_STABLE 5
+#define BS_OP_DELETE 6
+#define BS_OP_LIST 7
+#define BS_OP_ROLLBACK 8
+#define BS_OP_SYNC_STAB_ALL 9
+#define BS_OP_MAX 9
 
 #define BS_OP_PRIVATE_DATA_SIZE 256
 
@@ -39,9 +45,9 @@
 
 Blockstore opcode documentation:
 
-## BS_OP_READ / BS_OP_WRITE
+## BS_OP_READ / BS_OP_WRITE / BS_OP_WRITE_STABLE
 
-Read or write object data.
+Read or write object data. WRITE_STABLE writes a version that doesn't require marking as stable.
 
 Input:
 - oid = requested object
@@ -50,6 +56,7 @@ Input:
   - version == 0: read the last stable version,
   - version == UINT64_MAX: read the last version,
   - otherwise: read the newest version that is <= the specified version
+  - reads aren't guaranteed to return data from previous unfinished writes
   For writes:
   - if version == 0, a new version is assigned automatically
   - if version != 0, it is assigned for the new write if possible, otherwise -EINVAL is returned
@@ -92,7 +99,7 @@ Input:
 - buf = pre-allocated obj_ver_id array <len> units long
 
 Output:
-- retval = 0 or negative error number (-EINVAL)
+- retval = 0 or negative error number (-EINVAL, -ENOENT if no such version or -EBUSY if not synced)
 
 ## BS_OP_SYNC_STAB_ALL
 
@@ -110,6 +117,8 @@ Input:
 - oid.stripe = PG alignment
 - len = PG count or 0 to list all objects
 - offset = PG number
+- oid.inode = min inode number or 0 to list all inodes
+- version = max inode number or 0 to list all inodes
 
 Output:
 - retval = total obj_ver_id count
@@ -175,6 +184,7 @@ public:
     // FIXME rename to object_size
     uint32_t get_block_size();
     uint64_t get_block_count();
+    uint64_t get_free_block_count();
 
     uint32_t get_disk_alignment();
 };

blockstore_flush.cpp

@@ -1,14 +1,19 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 journal_flusher_t::journal_flusher_t(int flusher_count, blockstore_impl_t *bs)
 {
     this->bs = bs;
     this->flusher_count = flusher_count;
+    dequeuing = false;
     active_flushers = 0;
-    sync_threshold = flusher_count == 1 ? 1 : flusher_count/2;
-    journal_trim_interval = sync_threshold;
+    syncing_flushers = 0;
+    flusher_start_threshold = bs->journal_block_size / sizeof(journal_entry_stable);
+    journal_trim_interval = flusher_start_threshold;
     journal_trim_counter = 0;
-    journal_superblock = bs->journal.inmemory ? bs->journal.buffer : memalign(MEM_ALIGNMENT, bs->journal_block_size);
+    journal_superblock = bs->journal.inmemory ? bs->journal.buffer : memalign_or_die(MEM_ALIGNMENT, bs->journal_block_size);
     co = new journal_flusher_co[flusher_count];
     for (int i = 0; i < flusher_count; i++)
     {
@@ -55,17 +60,13 @@ journal_flusher_t::~journal_flusher_t()
 
 bool journal_flusher_t::is_active()
 {
-    return active_flushers > 0 || start_forced && flush_queue.size() > 0 || flush_queue.size() >= sync_threshold;
+    return active_flushers > 0 || dequeuing;
 }
 
 void journal_flusher_t::loop()
 {
-    for (int i = 0; i < flusher_count; i++)
+    for (int i = 0; (active_flushers > 0 || dequeuing) && i < flusher_count; i++)
     {
-        if (!active_flushers && (start_forced ? !flush_queue.size() : (flush_queue.size() < sync_threshold)))
-        {
-            return;
-        }
         co[i].loop();
     }
 }
@@ -83,6 +84,11 @@ void journal_flusher_t::enqueue_flush(obj_ver_id ov)
         flush_versions[ov.oid] = ov.version;
         flush_queue.push_back(ov.oid);
     }
+    if (!dequeuing && flush_queue.size() >= flusher_start_threshold)
+    {
+        dequeuing = true;
+        bs->ringloop->wakeup();
+    }
 }
 
 void journal_flusher_t::unshift_flush(obj_ver_id ov)
@@ -98,14 +104,25 @@ void journal_flusher_t::unshift_flush(obj_ver_id ov)
         flush_versions[ov.oid] = ov.version;
         flush_queue.push_front(ov.oid);
     }
+    if (!dequeuing && flush_queue.size() >= flusher_start_threshold)
+    {
+        dequeuing = true;
+        bs->ringloop->wakeup();
+    }
 }
 
-void journal_flusher_t::force_start()
+void journal_flusher_t::request_trim()
 {
-    start_forced = true;
+    dequeuing = true;
+    trim_wanted++;
     bs->ringloop->wakeup();
 }
 
+void journal_flusher_t::release_trim()
+{
+    trim_wanted--;
+}
+
 #define await_sqe(label) \
     resume_##label:\
         sqe = bs->get_sqe();\
@@ -116,6 +133,7 @@ void journal_flusher_t::force_start()
         }\
         data = ((ring_data_t*)sqe->user_data);
 
+// FIXME: Implement batch flushing
 bool journal_flusher_co::loop()
 {
     // This is much better than implementing the whole function as an FSM
@@ -155,10 +173,9 @@ bool journal_flusher_co::loop()
     else if (wait_state == 18)
         goto resume_18;
 resume_0:
-    if (!flusher->flush_queue.size() ||
-        !flusher->start_forced && !flusher->active_flushers && flusher->flush_queue.size() < flusher->sync_threshold)
+    if (!flusher->flush_queue.size() || !flusher->dequeuing)
     {
-        flusher->start_forced = false;
+        flusher->dequeuing = false;
         wait_state = 0;
         return true;
     }
@@ -173,7 +190,7 @@ resume_0:
         if (repeat_it != flusher->sync_to_repeat.end())
         {
 #ifdef BLOCKSTORE_DEBUG
-            printf("Postpone %lu:%lu v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
+            printf("Postpone %lx:%lx v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
             // We don't flush different parts of history of the same object in parallel
             // So we check if someone is already flushing this object
@@ -186,42 +203,112 @@ resume_0:
         }
         else
             flusher->sync_to_repeat[cur.oid] = 0;
+        if (dirty_end->second.journal_sector >= bs->journal.dirty_start &&
+            (bs->journal.dirty_start >= bs->journal.used_start ||
+            dirty_end->second.journal_sector < bs->journal.used_start))
+        {
+            flusher->enqueue_flush(cur);
+            // We can't flush journal sectors that are still written to
+            // However, as we group flushes by oid, current oid may have older writes to flush!
+            // And it may even block writes if we don't flush the older version
+            // (if it's in the beginning of the journal)...
+            // So first try to find an older version of the same object to flush.
+            bool found = false;
+            while (dirty_end != bs->dirty_db.begin())
+            {
+                dirty_end--;
+                if (dirty_end->first.oid != cur.oid)
+                {
+                    break;
+                }
+                if (!(dirty_end->second.journal_sector >= bs->journal.dirty_start &&
+                    (bs->journal.dirty_start >= bs->journal.used_start ||
+                    dirty_end->second.journal_sector < bs->journal.used_start)))
+                {
+                    found = true;
+                    cur.version = dirty_end->first.version;
+                    break;
+                }
+            }
+            if (!found)
+            {
+                // Try other objects
+                flusher->sync_to_repeat.erase(cur.oid);
+                int search_left = flusher->flush_queue.size() - 1;
 #ifdef BLOCKSTORE_DEBUG
-        printf("Flushing %lu:%lu v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
+                printf("Flusher overran writers (dirty_start=%08lx) - searching for older flushes (%d left)\n", bs->journal.dirty_start, search_left);
+#endif
+                while (search_left > 0)
+                {
+                    cur.oid = flusher->flush_queue.front();
+                    cur.version = flusher->flush_versions[cur.oid];
+                    flusher->flush_queue.pop_front();
+                    flusher->flush_versions.erase(cur.oid);
+                    dirty_end = bs->dirty_db.find(cur);
+                    if (dirty_end != bs->dirty_db.end())
+                    {
+                        if (dirty_end->second.journal_sector >= bs->journal.dirty_start &&
+                            (bs->journal.dirty_start >= bs->journal.used_start ||
+                            dirty_end->second.journal_sector < bs->journal.used_start))
+                        {
+#ifdef BLOCKSTORE_DEBUG
+                            printf("Write %lx:%lx v%lu is too new: offset=%08lx\n", cur.oid.inode, cur.oid.stripe, cur.version, dirty_end->second.journal_sector);
+#endif
+                            flusher->enqueue_flush(cur);
+                        }
+                        else
+                        {
+                            repeat_it = flusher->sync_to_repeat.find(cur.oid);
+                            if (repeat_it == flusher->sync_to_repeat.end())
+                            {
+                                flusher->sync_to_repeat[cur.oid] = 0;
+                                break;
+                            }
+                        }
+                    }
+                    search_left--;
+                }
+                if (search_left <= 0)
+                {
+#ifdef BLOCKSTORE_DEBUG
+                    printf("No older flushes, stopping\n");
+#endif
+                    flusher->dequeuing = false;
+                    wait_state = 0;
+                    return true;
+                }
+            }
+        }
+#ifdef BLOCKSTORE_DEBUG
+        printf("Flushing %lx:%lx v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
         flusher->active_flushers++;
 resume_1:
+        // Find it in clean_db
+        clean_it = bs->clean_db.find(cur.oid);
+        old_clean_loc = (clean_it != bs->clean_db.end() ? clean_it->second.location : UINT64_MAX);
         // Scan dirty versions of the object
         if (!scan_dirty(1))
         {
             wait_state += 1;
             return false;
         }
-        if (copy_count == 0 && clean_loc == UINT64_MAX && !has_delete && !has_empty)
+        // Writes and deletes shouldn't happen at the same time
+        assert(!(copy_count > 0 || has_writes) || !has_delete);
+        if (copy_count == 0 && !has_writes && !has_delete || has_delete && old_clean_loc == UINT64_MAX)
         {
             // Nothing to flush
-            flusher->active_flushers--;
-            repeat_it = flusher->sync_to_repeat.find(cur.oid);
-            if (repeat_it != flusher->sync_to_repeat.end() && repeat_it->second > cur.version)
-            {
-                // Requeue version
-                flusher->unshift_flush({ .oid = cur.oid, .version = repeat_it->second });
-            }
-            flusher->sync_to_repeat.erase(repeat_it);
-            wait_state = 0;
-            goto resume_0;
+            bs->erase_dirty(dirty_start, std::next(dirty_end), clean_loc);
+            goto trim_journal;
         }
-        // Find it in clean_db
-        clean_it = bs->clean_db.find(cur.oid);
-        old_clean_loc = (clean_it != bs->clean_db.end() ? clean_it->second.location : UINT64_MAX);
         if (clean_loc == UINT64_MAX)
         {
-            if (copy_count > 0 && has_delete || old_clean_loc == UINT64_MAX)
+            if (old_clean_loc == UINT64_MAX)
             {
                 // Object not allocated. This is a bug.
                 char err[1024];
                 snprintf(
-                    err, 1024, "BUG: Object %lu:%lu v%lu that we are trying to flush is not allocated on the data device",
+                    err, 1024, "BUG: Object %lx:%lx v%lu that we are trying to flush is not allocated on the data device",
                     cur.oid.inode, cur.oid.stripe, cur.version
                 );
                 throw std::runtime_error(err);
@@ -287,9 +374,8 @@ resume_1:
             data->iov = (struct iovec){ it->buf, (size_t)it->len };
             data->callback = simple_callback_w;
             my_uring_prep_writev(
-                sqe, bs->data_fd_index, &data->iov, 1, bs->data_offset + clean_loc + it->offset
+                sqe, bs->data_fd, &data->iov, 1, bs->data_offset + clean_loc + it->offset
             );
-            sqe->flags |= IOSQE_FIXED_FILE;
             wait_count++;
         }
         // Sync data before writing metadata
@@ -321,9 +407,8 @@ resume_1:
             data->iov = (struct iovec){ meta_old.buf, bs->meta_block_size };
             data->callback = simple_callback_w;
             my_uring_prep_writev(
-                sqe, bs->meta_fd_index, &data->iov, 1, bs->meta_offset + meta_old.sector
+                sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + meta_old.sector
             );
-            sqe->flags |= IOSQE_FIXED_FILE;
             wait_count++;
         }
         if (has_delete)
@@ -333,6 +418,7 @@ resume_1:
         else
         {
             clean_disk_entry *new_entry = (clean_disk_entry*)(meta_new.buf + meta_new.pos*bs->clean_entry_size);
+            assert(new_entry->oid.inode == 0 || new_entry->oid == cur.oid);
             new_entry->oid = cur.oid;
             new_entry->version = cur.version;
             if (!bs->inmemory_meta)
@@ -344,9 +430,8 @@ resume_1:
         data->iov = (struct iovec){ meta_new.buf, bs->meta_block_size };
         data->callback = simple_callback_w;
         my_uring_prep_writev(
-            sqe, bs->meta_fd_index, &data->iov, 1, bs->meta_offset + meta_new.sector
+            sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + meta_new.sector
         );
-        sqe->flags |= IOSQE_FIXED_FILE;
         wait_count++;
     resume_7:
         if (wait_count > 0)
@@ -389,8 +474,9 @@ resume_1:
         }
         // Update clean_db and dirty_db, free old data locations
         update_clean_db();
+    trim_journal:
         // Clear unused part of the journal every <journal_trim_interval> flushes
-        if (!((++flusher->journal_trim_counter) % flusher->journal_trim_interval))
+        if (!((++flusher->journal_trim_counter) % flusher->journal_trim_interval) || flusher->trim_wanted > 0)
         {
             flusher->journal_trim_counter = 0;
             if (bs->journal.trim())
@@ -408,8 +494,7 @@ resume_1:
                 ((journal_entry_start*)flusher->journal_superblock)->crc32 = je_crc32((journal_entry*)flusher->journal_superblock);
                 data->iov = (struct iovec){ flusher->journal_superblock, bs->journal_block_size };
                 data->callback = simple_callback_w;
-                my_uring_prep_writev(sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset);
-                sqe->flags |= IOSQE_FIXED_FILE;
+                my_uring_prep_writev(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset);
                 wait_count++;
             resume_13:
                 if (wait_count > 0)
@@ -421,7 +506,8 @@ resume_1:
         }
         // All done
 #ifdef BLOCKSTORE_DEBUG
-        printf("Flushed %lu:%lu v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
+        printf("Flushed %lx:%lx v%lu (%d copies, wr:%d, del:%d), %ld left\n", cur.oid.inode, cur.oid.stripe, cur.version,
+            copy_count, has_writes, has_delete, flusher->flush_queue.size());
 #endif
         flusher->active_flushers--;
         repeat_it = flusher->sync_to_repeat.find(cur.oid);
@@ -449,19 +535,25 @@ bool journal_flusher_co::scan_dirty(int wait_base)
     copy_count = 0;
     clean_loc = UINT64_MAX;
     has_delete = false;
-    has_empty = false;
+    has_writes = false;
     skip_copy = false;
     clean_init_bitmap = false;
     while (1)
     {
-        if (dirty_it->second.state == ST_J_STABLE && !skip_copy)
+        if (!IS_STABLE(dirty_it->second.state))
+        {
+            char err[1024];
+            snprintf(
+                err, 1024, "BUG: Unexpected dirty_entry %lx:%lx v%lu state during flush: %d",
+                dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version, dirty_it->second.state
+            );
+            throw std::runtime_error(err);
+        }
+        else if (IS_JOURNAL(dirty_it->second.state) && !skip_copy)
         {
             // First we submit all reads
-            if (dirty_it->second.len == 0)
-            {
-                has_empty = true;
-            }
-            else
+            has_writes = true;
+            if (dirty_it->second.len != 0)
             {
                 offset = dirty_it->second.offset;
                 end_offset = dirty_it->second.offset + dirty_it->second.len;
@@ -475,23 +567,22 @@ bool journal_flusher_co::scan_dirty(int wait_base)
                     {
                         submit_offset = dirty_it->second.location + offset - dirty_it->second.offset;
                         submit_len = it == v.end() || it->offset >= end_offset ? end_offset-offset : it->offset-offset;
-                        it = v.insert(it, (copy_buffer_t){ .offset = offset, .len = submit_len, .buf = memalign(MEM_ALIGNMENT, submit_len) });
+                        it = v.insert(it, (copy_buffer_t){ .offset = offset, .len = submit_len, .buf = memalign_or_die(MEM_ALIGNMENT, submit_len) });
                         copy_count++;
                         if (bs->journal.inmemory)
                         {
                             // Take it from memory
-                            memcpy(v.back().buf, bs->journal.buffer + submit_offset, submit_len);
+                            memcpy(it->buf, bs->journal.buffer + submit_offset, submit_len);
                         }
                         else
                         {
                             // Read it from disk
                             await_sqe(0);
-                            data->iov = (struct iovec){ v.back().buf, (size_t)submit_len };
+                            data->iov = (struct iovec){ it->buf, (size_t)submit_len };
                             data->callback = simple_callback_r;
                             my_uring_prep_readv(
-                                sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset + submit_offset
+                                sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset + submit_offset
                             );
-                            sqe->flags |= IOSQE_FIXED_FILE;
                             wait_count++;
                         }
                     }
@@ -501,30 +592,22 @@ bool journal_flusher_co::scan_dirty(int wait_base)
                 }
             }
         }
-        else if (dirty_it->second.state == ST_D_STABLE && !skip_copy)
+        else if (IS_BIG_WRITE(dirty_it->second.state) && !skip_copy)
         {
             // There is an unflushed big write. Copy small writes in its position
+            has_writes = true;
             clean_loc = dirty_it->second.location;
             clean_init_bitmap = true;
             clean_bitmap_offset = dirty_it->second.offset;
             clean_bitmap_len = dirty_it->second.len;
             skip_copy = true;
         }
-        else if (dirty_it->second.state == ST_DEL_STABLE && !skip_copy)
+        else if (IS_DELETE(dirty_it->second.state) && !skip_copy)
         {
             // There is an unflushed delete
             has_delete = true;
             skip_copy = true;
         }
-        else if (!IS_STABLE(dirty_it->second.state))
-        {
-            char err[1024];
-            snprintf(
-                err, 1024, "BUG: Unexpected dirty_entry %lu:%lu v%lu state during flush: %d",
-                dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version, dirty_it->second.state
-            );
-            throw std::runtime_error(err);
-        }
         dirty_start = dirty_it;
         if (dirty_it == bs->dirty_db.begin())
         {
@@ -560,7 +643,7 @@ bool journal_flusher_co::modify_meta_read(uint64_t meta_loc, flusher_meta_write_
     if (wr.it == flusher->meta_sectors.end())
     {
         // Not in memory yet, read it
-        wr.buf = memalign(MEM_ALIGNMENT, bs->meta_block_size);
+        wr.buf = memalign_or_die(MEM_ALIGNMENT, bs->meta_block_size);
         wr.it = flusher->meta_sectors.emplace(wr.sector, (meta_sector_t){
             .offset = wr.sector,
             .len = bs->meta_block_size,
@@ -573,9 +656,8 @@ bool journal_flusher_co::modify_meta_read(uint64_t meta_loc, flusher_meta_write_
         data->callback = simple_callback_r;
         wr.submitted = true;
         my_uring_prep_readv(
-            sqe, bs->meta_fd_index, &data->iov, 1, bs->meta_offset + wr.sector
+            sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + wr.sector
         );
-        sqe->flags |= IOSQE_FIXED_FILE;
         wait_count++;
     }
     else
@@ -591,7 +673,7 @@ void journal_flusher_co::update_clean_db()
     if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
     {
 #ifdef BLOCKSTORE_DEBUG
-        printf("Free block %lu\n", old_clean_loc >> bs->block_order);
+        printf("Free block %lu (new location is %lu)\n", old_clean_loc >> bs->block_order, clean_loc >> bs->block_order);
 #endif
         bs->data_alloc->set(old_clean_loc >> bs->block_order, false);
     }
@@ -638,14 +720,14 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
         });
     sync_found:
         cur_sync->ready_count++;
-        if (cur_sync->ready_count >= flusher->sync_threshold || !flusher->flush_queue.size())
+        flusher->syncing_flushers++;
+        if (flusher->syncing_flushers >= flusher->flusher_count || !flusher->flush_queue.size())
         {
             // Sync batch is ready. Do it.
             await_sqe(0);
             data->iov = { 0 };
             data->callback = simple_callback_w;
-            my_uring_prep_fsync(sqe, fsync_meta ? bs->meta_fd_index : bs->data_fd_index, IORING_FSYNC_DATASYNC);
-            sqe->flags |= IOSQE_FIXED_FILE;
+            my_uring_prep_fsync(sqe, fsync_meta ? bs->meta_fd : bs->data_fd, IORING_FSYNC_DATASYNC);
             cur_sync->state = 1;
             wait_count++;
         resume_1:
@@ -665,6 +747,7 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
             wait_state = 2;
             return false;
         }
+        flusher->syncing_flushers--;
         cur_sync->ready_count--;
         if (cur_sync->ready_count == 0)
         {

blockstore_flush.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 struct copy_buffer_t
 {
     uint64_t offset, len;
@@ -45,8 +48,8 @@ class journal_flusher_co
     std::map<object_id, uint64_t>::iterator repeat_it;
     std::function<void(ring_data_t*)> simple_callback_r, simple_callback_w;
 
-    bool skip_copy, has_delete, has_empty;
-    spp::sparse_hash_map<object_id, clean_entry>::iterator clean_it;
+    bool skip_copy, has_delete, has_writes;
+    blockstore_clean_db_t::iterator clean_it;
     std::vector<copy_buffer_t> v;
     std::vector<copy_buffer_t>::iterator it;
     int copy_count;
@@ -73,9 +76,10 @@ public:
 // Journal flusher itself
 class journal_flusher_t
 {
-    bool start_forced = false;
+    int trim_wanted = 0;
+    bool dequeuing;
     int flusher_count;
-    int sync_threshold;
+    int flusher_start_threshold;
     journal_flusher_co *co;
     blockstore_impl_t *bs;
     friend class journal_flusher_co;
@@ -84,6 +88,7 @@ class journal_flusher_t
     void* journal_superblock;
 
     int active_flushers;
+    int syncing_flushers;
     std::list<flusher_sync_t> syncs;
     std::map<object_id, uint64_t> sync_to_repeat;
 
@@ -95,7 +100,8 @@ public:
     ~journal_flusher_t();
     void loop();
     bool is_active();
-    void force_start();
+    void request_trim();
+    void release_trim();
     void enqueue_flush(obj_ver_id oid);
     void unshift_flush(obj_ver_id oid);
 };

blockstore_impl.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 blockstore_impl_t::blockstore_impl_t(blockstore_config_t & config, ring_loop_t *ringloop)
@@ -5,9 +8,9 @@ blockstore_impl_t::blockstore_impl_t(blockstore_config_t & config, ring_loop_t *
     assert(sizeof(blockstore_op_private_t) <= BS_OP_PRIVATE_DATA_SIZE);
     this->ringloop = ringloop;
     ring_consumer.loop = [this]() { loop(); };
-    ringloop->register_consumer(ring_consumer);
+    ringloop->register_consumer(&ring_consumer);
     initialized = 0;
-    zero_object = (uint8_t*)memalign(MEM_ALIGNMENT, block_size);
+    zero_object = (uint8_t*)memalign_or_die(MEM_ALIGNMENT, block_size);
     data_fd = meta_fd = journal.fd = -1;
     parse_config(config);
     try
@@ -36,7 +39,7 @@ blockstore_impl_t::~blockstore_impl_t()
     delete data_alloc;
     delete flusher;
     free(zero_object);
-    ringloop->unregister_consumer(ring_consumer);
+    ringloop->unregister_consumer(&ring_consumer);
     if (data_fd >= 0)
         close(data_fd);
     if (meta_fd >= 0 && meta_fd != data_fd)
@@ -98,10 +101,19 @@ void blockstore_impl_t::loop()
     {
         // try to submit ops
         unsigned initial_ring_space = ringloop->space_left();
+        // FIXME: rework this "sync polling"
         auto cur_sync = in_progress_syncs.begin();
         while (cur_sync != in_progress_syncs.end())
         {
-            continue_sync(*cur_sync++);
+            if (continue_sync(*cur_sync) != 2)
+            {
+                // List is unmodified
+                cur_sync++;
+            }
+            else
+            {
+                cur_sync = in_progress_syncs.begin();
+            }
         }
         auto cur = submit_queue.begin();
         int has_writes = 0;
@@ -115,19 +127,13 @@ void blockstore_impl_t::loop()
             if (PRIV(op)->wait_for)
             {
                 check_wait(op);
-#ifdef BLOCKSTORE_DEBUG
-                if (PRIV(op)->wait_for)
-                {
-                    printf("still waiting for %d\n", PRIV(op)->wait_for);
-                }
-#endif
                 if (PRIV(op)->wait_for == WAIT_SQE)
                 {
                     break;
                 }
                 else if (PRIV(op)->wait_for)
                 {
-                    if (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_DELETE)
+                    if (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_WRITE_STABLE || op->opcode == BS_OP_DELETE)
                     {
                         has_writes = 2;
                     }
@@ -136,12 +142,12 @@ void blockstore_impl_t::loop()
             }
             unsigned ring_space = ringloop->space_left();
             unsigned prev_sqe_pos = ringloop->save();
-            int dequeue_op = 0;
+            bool dequeue_op = false;
             if (op->opcode == BS_OP_READ)
             {
                 dequeue_op = dequeue_read(op);
             }
-            else if (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_DELETE)
+            else if (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_WRITE_STABLE)
             {
                 if (has_writes == 2)
                 {
@@ -151,6 +157,16 @@ void blockstore_impl_t::loop()
                 dequeue_op = dequeue_write(op);
                 has_writes = dequeue_op ? 1 : 2;
             }
+            else if (op->opcode == BS_OP_DELETE)
+            {
+                if (has_writes == 2)
+                {
+                    // Some writes could not be submitted
+                    break;
+                }
+                dequeue_op = dequeue_del(op);
+                has_writes = dequeue_op ? 1 : 2;
+            }
             else if (op->opcode == BS_OP_SYNC)
             {
                 // wait for all small writes to be submitted
@@ -166,16 +182,33 @@ void blockstore_impl_t::loop()
             }
             else if (op->opcode == BS_OP_STABLE)
             {
+                if (has_writes == 2)
+                {
+                    // Don't submit additional flushes before completing previous LISTs
+                    break;
+                }
                 dequeue_op = dequeue_stable(op);
             }
             else if (op->opcode == BS_OP_ROLLBACK)
             {
+                if (has_writes == 2)
+                {
+                    // Don't submit additional flushes before completing previous LISTs
+                    break;
+                }
                 dequeue_op = dequeue_rollback(op);
             }
             else if (op->opcode == BS_OP_LIST)
             {
-                process_list(op);
-                dequeue_op = true;
+                // Block LIST operation by previous modifications,
+                // so it always returns a consistent state snapshot
+                if (has_writes == 2 || inflight_writes > 0)
+                    has_writes = 2;
+                else
+                {
+                    process_list(op);
+                    dequeue_op = true;
+                }
             }
             if (dequeue_op)
             {
@@ -205,7 +238,7 @@ void blockstore_impl_t::loop()
         {
             live = true;
         }
-        queue_stall = !live && !ringloop->get_loop_again();
+        queue_stall = !live && !ringloop->has_work();
         live = false;
     }
 }
@@ -245,19 +278,9 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
         if (ringloop->space_left() < PRIV(op)->wait_detail)
         {
             // stop submission if there's still no free space
-            return;
-        }
-        PRIV(op)->wait_for = 0;
-    }
-    else if (PRIV(op)->wait_for == WAIT_IN_FLIGHT)
-    {
-        auto dirty_it = dirty_db.find((obj_ver_id){
-            .oid = op->oid,
-            .version = PRIV(op)->wait_detail,
-        });
-        if (dirty_it != dirty_db.end() && IS_IN_FLIGHT(dirty_it->second.state))
-        {
-            // do not submit
+#ifdef BLOCKSTORE_DEBUG
+            printf("Still waiting for %lu SQE(s)\n", PRIV(op)->wait_detail);
+#endif
             return;
         }
         PRIV(op)->wait_for = 0;
@@ -267,8 +290,12 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
         if (journal.used_start == PRIV(op)->wait_detail)
         {
             // do not submit
+#ifdef BLOCKSTORE_DEBUG
+            printf("Still waiting to flush journal offset %08lx\n", PRIV(op)->wait_detail);
+#endif
             return;
         }
+        flusher->release_trim();
         PRIV(op)->wait_for = 0;
     }
     else if (PRIV(op)->wait_for == WAIT_JOURNAL_BUFFER)
@@ -278,6 +305,9 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
             journal.sector_info[next].dirty)
         {
             // do not submit
+#ifdef BLOCKSTORE_DEBUG
+            printf("Still waiting for a journal buffer\n");
+#endif
             return;
         }
         PRIV(op)->wait_for = 0;
@@ -286,6 +316,9 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
     {
         if (!data_alloc->get_free_count() && !flusher->is_active())
         {
+#ifdef BLOCKSTORE_DEBUG
+            printf("Still waiting for free space on the data device\n");
+#endif
             return;
         }
         PRIV(op)->wait_for = 0;
@@ -299,17 +332,17 @@ void blockstore_impl_t::check_wait(blockstore_op_t *op)
 void blockstore_impl_t::enqueue_op(blockstore_op_t *op, bool first)
 {
     if (op->opcode < BS_OP_MIN || op->opcode > BS_OP_MAX ||
-        ((op->opcode == BS_OP_READ || op->opcode == BS_OP_WRITE) && (
+        ((op->opcode == BS_OP_READ || op->opcode == BS_OP_WRITE || op->opcode == BS_OP_WRITE_STABLE) && (
             op->offset >= block_size ||
             op->len > block_size-op->offset ||
             (op->len % disk_alignment)
         )) ||
-        readonly && op->opcode != BS_OP_READ ||
-        first && op->opcode == BS_OP_WRITE)
+        readonly && op->opcode != BS_OP_READ && op->opcode != BS_OP_LIST ||
+        first && (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_WRITE_STABLE))
     {
         // Basic verification not passed
         op->retval = -EINVAL;
-        op->callback(op);
+        std::function<void (blockstore_op_t*)>(op->callback)(op);
         return;
     }
     if (op->opcode == BS_OP_SYNC_STAB_ALL)
@@ -350,21 +383,21 @@ void blockstore_impl_t::enqueue_op(blockstore_op_t *op, bool first)
             }
         };
     }
-    if (op->opcode == BS_OP_WRITE && !enqueue_write(op))
+    if ((op->opcode == BS_OP_WRITE || op->opcode == BS_OP_WRITE_STABLE || op->opcode == BS_OP_DELETE) && !enqueue_write(op))
     {
-        op->callback(op);
+        std::function<void (blockstore_op_t*)>(op->callback)(op);
         return;
     }
-    if (0 && op->opcode == BS_OP_SYNC && immediate_commit)
+    if (op->opcode == BS_OP_SYNC && immediate_commit == IMMEDIATE_ALL)
     {
         op->retval = 0;
-        op->callback(op);
+        std::function<void (blockstore_op_t*)>(op->callback)(op);
         return;
     }
     // Call constructor without allocating memory. We'll call destructor before returning op back
     new ((void*)op->private_data) blockstore_op_private_t;
     PRIV(op)->wait_for = 0;
-    PRIV(op)->sync_state = 0;
+    PRIV(op)->op_state = 0;
     PRIV(op)->pending_ops = 0;
     if (!first)
     {
@@ -377,82 +410,201 @@ void blockstore_impl_t::enqueue_op(blockstore_op_t *op, bool first)
     ringloop->wakeup();
 }
 
+static bool replace_stable(object_id oid, uint64_t version, int search_start, int search_end, obj_ver_id* list)
+{
+    while (search_start < search_end)
+    {
+        int pos = search_start+(search_end-search_start)/2;
+        if (oid < list[pos].oid)
+        {
+            search_end = pos;
+        }
+        else if (list[pos].oid < oid)
+        {
+            search_start = pos+1;
+        }
+        else
+        {
+            list[pos].version = version;
+            return true;
+        }
+    }
+    return false;
+}
+
 void blockstore_impl_t::process_list(blockstore_op_t *op)
 {
-    // Count objects
     uint32_t list_pg = op->offset;
     uint32_t pg_count = op->len;
-    uint64_t parity_block_size = op->oid.stripe;
-    if (pg_count != 0 && (parity_block_size < MIN_BLOCK_SIZE || list_pg >= pg_count))
+    uint64_t pg_stripe_size = op->oid.stripe;
+    uint64_t min_inode = op->oid.inode;
+    uint64_t max_inode = op->version;
+    // Check PG
+    if (pg_count != 0 && (pg_stripe_size < MIN_BLOCK_SIZE || list_pg >= pg_count))
     {
         op->retval = -EINVAL;
         FINISH_OP(op);
         return;
     }
-    uint64_t stable_count = 0;
-    if (pg_count > 0)
-    {
-        for (auto it = clean_db.begin(); it != clean_db.end(); it++)
-        {
-            uint32_t pg = (it->first.inode + it->first.stripe / parity_block_size) % pg_count;
-            if (pg == list_pg)
-            {
-                stable_count++;
-            }
-        }
-    }
-    else
-    {
-        stable_count = clean_db.size();
-    }
-    uint64_t total_count = stable_count;
-    for (auto it = dirty_db.begin(); it != dirty_db.end(); it++)
-    {
-        if (!pg_count || ((it->first.oid.inode + it->first.oid.stripe / parity_block_size) % pg_count) == list_pg)
-        {
-            if (IS_STABLE(it->second.state))
-            {
-                stable_count++;
-            }
-            total_count++;
-        }
-    }
-    // Allocate memory
-    op->version = stable_count;
-    op->retval = total_count;
-    op->buf = malloc(sizeof(obj_ver_id) * total_count);
-    if (!op->buf)
+    // Copy clean_db entries (sorted)
+    int stable_count = 0, stable_alloc = clean_db.size() / (pg_count ? pg_count : 1);
+    obj_ver_id *stable = (obj_ver_id*)malloc(sizeof(obj_ver_id) * stable_alloc);
+    if (!stable)
     {
         op->retval = -ENOMEM;
         FINISH_OP(op);
         return;
     }
-    obj_ver_id *vers = (obj_ver_id*)op->buf;
-    int i = 0;
-    for (auto it = clean_db.begin(); it != clean_db.end(); it++)
     {
-        if (!pg_count || ((it->first.inode + it->first.stripe / parity_block_size) % pg_count) == list_pg)
+        auto clean_it = clean_db.begin(), clean_end = clean_db.end();
+        if ((min_inode != 0 || max_inode != 0) && min_inode <= max_inode)
         {
-            vers[i++] = {
-                .oid = it->first,
-                .version = it->second.version,
-            };
+            clean_it = clean_db.lower_bound({
+                .inode = min_inode,
+                .stripe = 0,
+            });
+            clean_end = clean_db.upper_bound({
+                .inode = max_inode,
+                .stripe = UINT64_MAX,
+            });
         }
-    }
-    int j = stable_count;
-    for (auto it = dirty_db.begin(); it != dirty_db.end(); it++)
-    {
-        if (!pg_count || ((it->first.oid.inode + it->first.oid.stripe / parity_block_size) % pg_count) == list_pg)
+        for (; clean_it != clean_end; clean_it++)
         {
-            if (IS_STABLE(it->second.state))
+            if (!pg_count || ((clean_it->first.inode + clean_it->first.stripe / pg_stripe_size) % pg_count) == list_pg)
             {
-                vers[i++] = it->first;
-            }
-            else
-            {
-                vers[j++] = it->first;
+                if (stable_count >= stable_alloc)
+                {
+                    stable_alloc += 32768;
+                    stable = (obj_ver_id*)realloc(stable, sizeof(obj_ver_id) * stable_alloc);
+                    if (!stable)
+                    {
+                        op->retval = -ENOMEM;
+                        FINISH_OP(op);
+                        return;
+                    }
+                }
+                stable[stable_count++] = {
+                    .oid = clean_it->first,
+                    .version = clean_it->second.version,
+                };
             }
         }
     }
+    int clean_stable_count = stable_count;
+    // Copy dirty_db entries (sorted, too)
+    int unstable_count = 0, unstable_alloc = 0;
+    obj_ver_id *unstable = NULL;
+    {
+        auto dirty_it = dirty_db.begin(), dirty_end = dirty_db.end();
+        if ((min_inode != 0 || max_inode != 0) && min_inode <= max_inode)
+        {
+            dirty_it = dirty_db.lower_bound({
+                .oid = {
+                    .inode = min_inode,
+                    .stripe = 0,
+                },
+                .version = 0,
+            });
+            dirty_end = dirty_db.upper_bound({
+                .oid = {
+                    .inode = max_inode,
+                    .stripe = UINT64_MAX,
+                },
+                .version = UINT64_MAX,
+            });
+        }
+        for (; dirty_it != dirty_end; dirty_it++)
+        {
+            if (!pg_count || ((dirty_it->first.oid.inode + dirty_it->first.oid.stripe / pg_stripe_size) % pg_count) == list_pg)
+            {
+                if (IS_DELETE(dirty_it->second.state))
+                {
+                    // Deletions are always stable, so try to zero out two possible entries
+                    if (!replace_stable(dirty_it->first.oid, 0, 0, clean_stable_count, stable))
+                    {
+                        replace_stable(dirty_it->first.oid, 0, clean_stable_count, stable_count, stable);
+                    }
+                }
+                else if (IS_STABLE(dirty_it->second.state))
+                {
+                    // First try to replace a clean stable version in the first part of the list
+                    if (!replace_stable(dirty_it->first.oid, dirty_it->first.version, 0, clean_stable_count, stable))
+                    {
+                        // Then try to replace the last dirty stable version in the second part of the list
+                        if (stable[stable_count-1].oid == dirty_it->first.oid)
+                        {
+                            stable[stable_count-1].version = dirty_it->first.version;
+                        }
+                        else
+                        {
+                            if (stable_count >= stable_alloc)
+                            {
+                                stable_alloc += 32768;
+                                stable = (obj_ver_id*)realloc(stable, sizeof(obj_ver_id) * stable_alloc);
+                                if (!stable)
+                                {
+                                    if (unstable)
+                                        free(unstable);
+                                    op->retval = -ENOMEM;
+                                    FINISH_OP(op);
+                                    return;
+                                }
+                            }
+                            stable[stable_count++] = dirty_it->first;
+                        }
+                    }
+                }
+                else
+                {
+                    if (unstable_count >= unstable_alloc)
+                    {
+                        unstable_alloc += 32768;
+                        unstable = (obj_ver_id*)realloc(unstable, sizeof(obj_ver_id) * unstable_alloc);
+                        if (!unstable)
+                        {
+                            if (stable)
+                                free(stable);
+                            op->retval = -ENOMEM;
+                            FINISH_OP(op);
+                            return;
+                        }
+                    }
+                    unstable[unstable_count++] = dirty_it->first;
+                }
+            }
+        }
+    }
+    // Remove zeroed out stable entries
+    int j = 0;
+    for (int i = 0; i < stable_count; i++)
+    {
+        if (stable[i].version != 0)
+        {
+            stable[j++] = stable[i];
+        }
+    }
+    stable_count = j;
+    if (stable_count+unstable_count > stable_alloc)
+    {
+        stable_alloc = stable_count+unstable_count;
+        stable = (obj_ver_id*)realloc(stable, sizeof(obj_ver_id) * stable_alloc);
+        if (!stable)
+        {
+            if (unstable)
+                free(unstable);
+            op->retval = -ENOMEM;
+            FINISH_OP(op);
+            return;
+        }
+    }
+    // Copy unstable entries
+    for (int i = 0; i < unstable_count; i++)
+    {
+        stable[j++] = unstable[i];
+    }
+    free(unstable);
+    op->version = stable_count;
+    op->retval = stable_count+unstable_count;
+    op->buf = stable;
     FINISH_OP(op);
 }

blockstore_impl.h

@@ -1,14 +1,15 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include "blockstore.h"
-#include "timerfd_interval.h"
 
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <malloc.h>
 #include <linux/fs.h>
 
 #include <vector>
@@ -16,43 +17,40 @@
 #include <deque>
 #include <new>
 
-#include "sparsepp/sparsepp/spp.h"
+#include "cpp-btree/btree_map.h"
 
+#include "malloc_or_die.h"
 #include "allocator.h"
 
 //#define BLOCKSTORE_DEBUG
 
 // States are not stored on disk. Instead, they're deduced from the journal
-// FIXME: Rename to BS_ST_*
 
-#define ST_J_IN_FLIGHT 1
-#define ST_J_SUBMITTED 2
-#define ST_J_WRITTEN 3
-#define ST_J_SYNCED 4
-#define ST_J_STABLE 5
+#define BS_ST_SMALL_WRITE 0x01
+#define BS_ST_BIG_WRITE 0x02
+#define BS_ST_DELETE 0x03
 
-#define ST_D_IN_FLIGHT 15
-#define ST_D_SUBMITTED 16
-#define ST_D_WRITTEN 17
-#define ST_D_META_WRITTEN 19
-#define ST_D_META_SYNCED 20
-#define ST_D_STABLE 21
+#define BS_ST_WAIT_BIG 0x10
+#define BS_ST_IN_FLIGHT 0x20
+#define BS_ST_SUBMITTED 0x30
+#define BS_ST_WRITTEN 0x40
+#define BS_ST_SYNCED 0x50
+#define BS_ST_STABLE 0x60
 
-#define ST_DEL_IN_FLIGHT 31
-#define ST_DEL_SUBMITTED 32
-#define ST_DEL_WRITTEN 33
-#define ST_DEL_SYNCED 34
-#define ST_DEL_STABLE 35
+#define BS_ST_INSTANT 0x100
 
-#define ST_CURRENT 48
+#define IMMEDIATE_NONE 0
+#define IMMEDIATE_SMALL 1
+#define IMMEDIATE_ALL 2
 
-#define IS_IN_FLIGHT(st) (st == ST_J_IN_FLIGHT || st == ST_D_IN_FLIGHT || st == ST_DEL_IN_FLIGHT || st == ST_J_SUBMITTED || st == ST_D_SUBMITTED || st == ST_DEL_SUBMITTED)
-#define IS_STABLE(st) (st == ST_J_STABLE || st == ST_D_STABLE || st == ST_DEL_STABLE || st == ST_CURRENT)
-#define IS_SYNCED(st) (IS_STABLE(st) || st == ST_J_SYNCED || st == ST_D_META_SYNCED || st == ST_DEL_SYNCED)
-#define IS_JOURNAL(st) (st >= ST_J_SUBMITTED && st <= ST_J_STABLE)
-#define IS_BIG_WRITE(st) (st >= ST_D_SUBMITTED && st <= ST_D_STABLE)
-#define IS_DELETE(st) (st >= ST_DEL_SUBMITTED && st <= ST_DEL_STABLE)
-#define IS_UNSYNCED(st) (st >= ST_J_SUBMITTED && st <= ST_J_WRITTEN || st >= ST_D_SUBMITTED && st <= ST_D_META_WRITTEN || st >= ST_DEL_SUBMITTED && st <= ST_DEL_WRITTEN)
+#define BS_ST_TYPE_MASK 0x0F
+#define BS_ST_WORKFLOW_MASK 0xF0
+#define IS_IN_FLIGHT(st) (((st) & 0xF0) <= BS_ST_SUBMITTED)
+#define IS_STABLE(st) (((st) & 0xF0) == BS_ST_STABLE)
+#define IS_SYNCED(st) (((st) & 0xF0) >= BS_ST_SYNCED)
+#define IS_JOURNAL(st) (((st) & 0x0F) == BS_ST_SMALL_WRITE)
+#define IS_BIG_WRITE(st) (((st) & 0x0F) == BS_ST_BIG_WRITE)
+#define IS_DELETE(st) (((st) & 0x0F) == BS_ST_DELETE)
 
 #define BS_SUBMIT_GET_SQE(sqe, data) \
     BS_SUBMIT_GET_ONLY_SQE(sqe); \
@@ -124,8 +122,6 @@ struct __attribute__((__packed__)) dirty_entry
 
 // Suspend operation until there are more free SQEs
 #define WAIT_SQE 1
-// Suspend operation until version <wait_detail> of object <oid> is written
-#define WAIT_IN_FLIGHT 2
 // Suspend operation until there are <wait_detail> bytes of free space in the journal on disk
 #define WAIT_JOURNAL 3
 // Suspend operation until the next journal sector buffer is free
@@ -139,7 +135,7 @@ struct fulfill_read_t
 };
 
 #define PRIV(op) ((blockstore_op_private_t*)(op)->private_data)
-#define FINISH_OP(op) PRIV(op)->~blockstore_op_private_t(); op->callback(op)
+#define FINISH_OP(op) PRIV(op)->~blockstore_op_private_t(); std::function<void (blockstore_op_t*)>(op->callback)(op)
 
 struct blockstore_op_private_t
 {
@@ -147,12 +143,13 @@ struct blockstore_op_private_t
     int wait_for;
     uint64_t wait_detail;
     int pending_ops;
+    int op_state;
 
     // Read
     std::vector<fulfill_read_t> read_vec;
 
     // Sync, write
-    uint64_t min_used_journal_sector, max_used_journal_sector;
+    uint64_t min_flushed_journal_sector, max_flushed_journal_sector;
 
     // Write
     struct iovec iov_zerofill[3];
@@ -161,9 +158,13 @@ struct blockstore_op_private_t
     std::vector<obj_ver_id> sync_big_writes, sync_small_writes;
     int sync_small_checked, sync_big_checked;
     std::list<blockstore_op_t*>::iterator in_progress_ptr;
-    int sync_state, prev_sync_count;
+    int prev_sync_count;
 };
 
+// https://github.com/algorithm-ninja/cpp-btree
+// https://github.com/greg7mdp/sparsepp/ was used previously, but it was TERRIBLY slow after resizing
+// with sparsepp, random reads dropped to ~700 iops very fast with just as much as ~32k objects in the DB
+typedef btree::btree_map<object_id, clean_entry> blockstore_clean_db_t;
 typedef std::map<obj_ver_id, dirty_entry> blockstore_dirty_db_t;
 
 #include "blockstore_init.h"
@@ -177,29 +178,30 @@ class blockstore_impl_t
     uint32_t block_size;
     uint64_t meta_offset;
     uint64_t data_offset;
-    uint64_t cfg_journal_size;
+    uint64_t cfg_journal_size, cfg_data_size;
     // Required write alignment and journal/metadata/data areas' location alignment
-    uint32_t disk_alignment = 512;
+    uint32_t disk_alignment = 4096;
     // Journal block size - minimum_io_size of the journal device is the best choice
-    uint64_t journal_block_size = 512;
+    uint64_t journal_block_size = 4096;
     // Metadata block size - minimum_io_size of the metadata device is the best choice
-    uint64_t meta_block_size = 512;
+    uint64_t meta_block_size = 4096;
     // Sparse write tracking granularity. 4 KB is a good choice. Must be a multiple of disk_alignment
     uint64_t bitmap_granularity = 4096;
     bool readonly = false;
+    // By default, Blockstore locks all opened devices exclusively. This option can be used to disable locking
+    bool disable_flock = false;
     // It is safe to disable fsync() if drive write cache is writethrough
     bool disable_data_fsync = false, disable_meta_fsync = false, disable_journal_fsync = false;
     // Enable if you want every operation to be executed with an "implicit fsync"
-    // FIXME Not implemented yet
-    bool immediate_commit = false;
+    // Suitable only for server SSDs with capacitors, requires disabled data and journal fsyncs
+    int immediate_commit = IMMEDIATE_NONE;
     bool inmemory_meta = false;
     int flusher_count;
     /******* END OF OPTIONS *******/
 
     struct ring_consumer_t ring_consumer;
 
-    // Another option is https://github.com/algorithm-ninja/cpp-btree
-    spp::sparse_hash_map<object_id, clean_entry> clean_db;
+    blockstore_clean_db_t clean_db;
     uint8_t *clean_bitmap = NULL;
     blockstore_dirty_db_t dirty_db;
     std::list<blockstore_op_t*> submit_queue; // FIXME: funny thing is that vector is better here
@@ -216,7 +218,6 @@ class blockstore_impl_t
     int data_fd;
     uint64_t meta_size, meta_area, meta_len;
     uint64_t data_size, data_len;
-    int meta_fd_index, data_fd_index, journal_fd_index;
 
     void *metadata_buffer = NULL;
 
@@ -225,6 +226,7 @@ class blockstore_impl_t
 
     bool live = false, queue_stall = false;
     ring_loop_t *ringloop;
+    int inflight_writes = 0;
 
     bool stop_sync_submitted;
 
@@ -265,7 +267,7 @@ class blockstore_impl_t
     bool enqueue_write(blockstore_op_t *op);
     int dequeue_write(blockstore_op_t *op);
     int dequeue_del(blockstore_op_t *op);
-    void ack_write(blockstore_op_t *op);
+    int continue_write(blockstore_op_t *op);
     void release_journal_sectors(blockstore_op_t *op);
     void handle_write_event(ring_data_t *data, blockstore_op_t *op);
 
@@ -278,11 +280,15 @@ class blockstore_impl_t
 
     // Stabilize
     int dequeue_stable(blockstore_op_t *op);
+    int continue_stable(blockstore_op_t *op);
+    void mark_stable(const obj_ver_id & ov);
     void handle_stable_event(ring_data_t *data, blockstore_op_t *op);
     void stabilize_object(object_id oid, uint64_t max_ver);
 
     // Rollback
     int dequeue_rollback(blockstore_op_t *op);
+    int continue_rollback(blockstore_op_t *op);
+    void mark_rolled_back(const obj_ver_id & ov);
     void handle_rollback_event(ring_data_t *data, blockstore_op_t *op);
     void erase_dirty(blockstore_dirty_db_t::iterator dirty_start, blockstore_dirty_db_t::iterator dirty_end, uint64_t clean_loc);
 
@@ -317,5 +323,6 @@ public:
 
     inline uint32_t get_block_size() { return block_size; }
     inline uint64_t get_block_count() { return block_count; }
+    inline uint64_t get_free_block_count() { return data_alloc->get_free_count(); }
     inline uint32_t get_disk_alignment() { return disk_alignment; }
 };

blockstore_init.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 blockstore_init_meta::blockstore_init_meta(blockstore_impl_t *bs)
@@ -55,8 +58,7 @@ int blockstore_init_meta::loop()
                 bs->meta_len - metadata_read > bs->metadata_buf_size ? bs->metadata_buf_size : bs->meta_len - metadata_read,
             };
             data->callback = [this](ring_data_t *data) { handle_event(data); };
-            my_uring_prep_readv(sqe, bs->meta_fd_index, &data->iov, 1, bs->meta_offset + metadata_read);
-            sqe->flags |= IOSQE_FIXED_FILE;
+            my_uring_prep_readv(sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + metadata_read);
             bs->ringloop->submit();
             submitted = (prev == 1 ? 2 : 1);
             prev = submitted;
@@ -109,13 +111,13 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
                 {
                     // free the previous block
 #ifdef BLOCKSTORE_DEBUG
-                    printf("Free block %lu\n", clean_it->second.location >> bs->block_order);
+                    printf("Free block %lu (new location is %lu)\n", clean_it->second.location >> block_order, done_cnt+i >> block_order);
 #endif
                     bs->data_alloc->set(clean_it->second.location >> block_order, false);
                 }
                 entries_loaded++;
 #ifdef BLOCKSTORE_DEBUG
-                printf("Allocate block (clean entry) %lu: %lu:%lu v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
+                printf("Allocate block (clean entry) %lu: %lx:%lx v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
 #endif
                 bs->data_alloc->set(done_cnt+i, true);
                 bs->clean_db[entry->oid] = (struct clean_entry){
@@ -126,7 +128,7 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
             else
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("Old clean entry %lu: %lu:%lu v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
+                printf("Old clean entry %lu: %lx:%lx v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
 #endif
             }
         }
@@ -203,11 +205,7 @@ int blockstore_init_journal::loop()
         goto resume_7;
     printf("Reading blockstore journal\n");
     if (!bs->journal.inmemory)
-    {
-        submitted_buf = memalign(MEM_ALIGNMENT, 2*bs->journal.block_size);
-        if (!submitted_buf)
-            throw std::bad_alloc();
-    }
+        submitted_buf = memalign_or_die(MEM_ALIGNMENT, 2*bs->journal.block_size);
     else
         submitted_buf = bs->journal.buffer;
     // Read first block of the journal
@@ -217,8 +215,7 @@ int blockstore_init_journal::loop()
     data = ((ring_data_t*)sqe->user_data);
     data->iov = { submitted_buf, bs->journal.block_size };
     data->callback = simple_callback;
-    my_uring_prep_readv(sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset);
-    sqe->flags |= IOSQE_FIXED_FILE;
+    my_uring_prep_readv(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset);
     bs->ringloop->submit();
     wait_count = 1;
 resume_1:
@@ -256,8 +253,7 @@ resume_1:
             GET_SQE();
             data->iov = (struct iovec){ submitted_buf, 2*bs->journal.block_size };
             data->callback = simple_callback;
-            my_uring_prep_writev(sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset);
-            sqe->flags |= IOSQE_FIXED_FILE;
+            my_uring_prep_writev(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset);
             wait_count++;
             bs->ringloop->submit();
         resume_6:
@@ -269,8 +265,7 @@ resume_1:
             if (!bs->disable_journal_fsync)
             {
                 GET_SQE();
-                my_uring_prep_fsync(sqe, bs->journal_fd_index, IORING_FSYNC_DATASYNC);
-                sqe->flags |= IOSQE_FIXED_FILE;
+                my_uring_prep_fsync(sqe, bs->journal.fd, IORING_FSYNC_DATASYNC);
                 data->iov = { 0 };
                 data->callback = simple_callback;
                 wait_count++;
@@ -321,7 +316,7 @@ resume_1:
                 if (journal_pos < bs->journal.used_start)
                     end = bs->journal.used_start;
                 if (!bs->journal.inmemory)
-                    submitted_buf = memalign(MEM_ALIGNMENT, JOURNAL_BUFFER_SIZE);
+                    submitted_buf = memalign_or_die(MEM_ALIGNMENT, JOURNAL_BUFFER_SIZE);
                 else
                     submitted_buf = bs->journal.buffer + journal_pos;
                 data->iov = {
@@ -329,8 +324,7 @@ resume_1:
                     end - journal_pos < JOURNAL_BUFFER_SIZE ? end - journal_pos : JOURNAL_BUFFER_SIZE,
                 };
                 data->callback = [this](ring_data_t *data1) { handle_event(data1); };
-                my_uring_prep_readv(sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset + journal_pos);
-                sqe->flags |= IOSQE_FIXED_FILE;
+                my_uring_prep_readv(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset + journal_pos);
                 bs->ringloop->submit();
             }
             while (done.size() > 0)
@@ -345,8 +339,7 @@ resume_1:
                         GET_SQE();
                         data->iov = { init_write_buf, bs->journal.block_size };
                         data->callback = simple_callback;
-                        my_uring_prep_writev(sqe, bs->journal_fd_index, &data->iov, 1, bs->journal.offset + init_write_sector);
-                        sqe->flags |= IOSQE_FIXED_FILE;
+                        my_uring_prep_writev(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset + init_write_sector);
                         wait_count++;
                         bs->ringloop->submit();
                     resume_7:
@@ -360,8 +353,7 @@ resume_1:
                             GET_SQE();
                             data->iov = { 0 };
                             data->callback = simple_callback;
-                            my_uring_prep_fsync(sqe, bs->journal_fd_index, IORING_FSYNC_DATASYNC);
-                            sqe->flags |= IOSQE_FIXED_FILE;
+                            my_uring_prep_fsync(sqe, bs->journal.fd, IORING_FSYNC_DATASYNC);
                             wait_count++;
                             bs->ringloop->submit();
                         }
@@ -409,8 +401,9 @@ resume_1:
     }
     // Trim journal on start so we don't stall when all entries are older
     bs->journal.trim();
+    bs->journal.dirty_start = bs->journal.next_free;
     printf(
-        "Journal entries loaded: %lu, free journal space: %lu bytes (%lu..%lu is used), free blocks: %lu / %lu\n",
+        "Journal entries loaded: %lu, free journal space: %lu bytes (%08lx..%08lx is used), free blocks: %lu / %lu\n",
         entries_loaded,
         (bs->journal.next_free >= bs->journal.used_start
             ? bs->journal.len-bs->journal.block_size - (bs->journal.next_free-bs->journal.used_start)
@@ -446,7 +439,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
         {
             journal_entry *je = (journal_entry*)(buf + proc_pos - done_pos + pos);
             if (je->magic != JOURNAL_MAGIC || je_crc32(je) != je->crc32 ||
-                je->type < JE_SMALL_WRITE || je->type > JE_DELETE || started && je->crc32_prev != crc32_last)
+                je->type < JE_MIN || je->type > JE_MAX || started && je->crc32_prev != crc32_last)
             {
                 if (pos == 0)
                 {
@@ -460,10 +453,15 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                     break;
                 }
             }
-            if (je->type == JE_SMALL_WRITE)
+            if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_small_write oid=%lu:%lu ver=%lu offset=%u len=%u\n", je->small_write.oid.inode, je->small_write.oid.stripe, je->small_write.version, je->small_write.offset, je->small_write.len);
+                printf(
+                    "je_small_write%s oid=%lx:%lx ver=%lu offset=%u len=%u\n",
+                    je->type == JE_SMALL_WRITE_INSTANT ? "_instant" : "",
+                    je->small_write.oid.inode, je->small_write.oid.stripe, je->small_write.version,
+                    je->small_write.offset, je->small_write.len
+                );
 #endif
                 // oid, version, offset, len
                 uint64_t prev_free = next_free;
@@ -481,7 +479,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                 if (location != je->small_write.data_offset)
                 {
                     char err[1024];
-                    snprintf(err, 1024, "BUG: calculated journal data offset (%lu) != stored journal data offset (%lu)", location, je->small_write.data_offset);
+                    snprintf(err, 1024, "BUG: calculated journal data offset (%08lx) != stored journal data offset (%08lx)", location, je->small_write.data_offset);
                     throw std::runtime_error(err);
                 }
                 uint32_t data_crc32 = 0;
@@ -516,7 +514,9 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                 if (data_crc32 != je->small_write.crc32_data)
                 {
                     // journal entry is corrupt, stop here
-                    // interesting thing is that we must clear the corrupt entry if we're not readonly
+                    // interesting thing is that we must clear the corrupt entry if we're not readonly,
+                    // because we don't write next entries in the same journal block
+                    printf("Journal entry data is corrupt (data crc32 %x != %x)\n", data_crc32, je->small_write.crc32_data);
                     memset(buf + proc_pos - done_pos + pos, 0, bs->journal.block_size - pos);
                     bs->journal.next_free = prev_free;
                     init_write_buf = buf + proc_pos - done_pos;
@@ -525,14 +525,14 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                 }
                 auto clean_it = bs->clean_db.find(je->small_write.oid);
                 if (clean_it == bs->clean_db.end() ||
-                    clean_it->second.version < je->big_write.version)
+                    clean_it->second.version < je->small_write.version)
                 {
                     obj_ver_id ov = {
                         .oid = je->small_write.oid,
                         .version = je->small_write.version,
                     };
                     bs->dirty_db.emplace(ov, (dirty_entry){
-                        .state = ST_J_SYNCED,
+                        .state = (BS_ST_SMALL_WRITE | BS_ST_SYNCED),
                         .flags = 0,
                         .location = location,
                         .offset = je->small_write.offset,
@@ -541,16 +541,27 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                     });
                     bs->journal.used_sectors[proc_pos]++;
 #ifdef BLOCKSTORE_DEBUG
-                    printf("journal offset %lu is used by %lu:%lu v%lu\n", proc_pos, ov.oid.inode, ov.oid.stripe, ov.version);
+                    printf(
+                        "journal offset %08lx is used by %lx:%lx v%lu (%lu refs)\n",
+                        proc_pos, ov.oid.inode, ov.oid.stripe, ov.version, bs->journal.used_sectors[proc_pos]
+                    );
 #endif
                     auto & unstab = bs->unstable_writes[ov.oid];
                     unstab = unstab < ov.version ? ov.version : unstab;
+                    if (je->type == JE_SMALL_WRITE_INSTANT)
+                    {
+                        bs->mark_stable(ov);
+                    }
                 }
             }
-            else if (je->type == JE_BIG_WRITE)
+            else if (je->type == JE_BIG_WRITE || je->type == JE_BIG_WRITE_INSTANT)
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_big_write oid=%lu:%lu ver=%lu loc=%lu\n", je->big_write.oid.inode, je->big_write.oid.stripe, je->big_write.version, je->big_write.location);
+                printf(
+                    "je_big_write%s oid=%lx:%lx ver=%lu loc=%lu\n",
+                    je->type == JE_BIG_WRITE_INSTANT ? "_instant" : "",
+                    je->big_write.oid.inode, je->big_write.oid.stripe, je->big_write.version, je->big_write.location
+                );
 #endif
                 auto clean_it = bs->clean_db.find(je->big_write.oid);
                 if (clean_it == bs->clean_db.end() ||
@@ -562,7 +573,7 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                         .version = je->big_write.version,
                     };
                     bs->dirty_db.emplace(ov, (dirty_entry){
-                        .state = ST_D_META_SYNCED,
+                        .state = (BS_ST_BIG_WRITE | BS_ST_SYNCED),
                         .flags = 0,
                         .location = je->big_write.location,
                         .offset = je->big_write.offset,
@@ -576,116 +587,63 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                     bs->journal.used_sectors[proc_pos]++;
                     auto & unstab = bs->unstable_writes[ov.oid];
                     unstab = unstab < ov.version ? ov.version : unstab;
+                    if (je->type == JE_BIG_WRITE_INSTANT)
+                    {
+                        bs->mark_stable(ov);
+                    }
                 }
             }
             else if (je->type == JE_STABLE)
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_stable oid=%lu:%lu ver=%lu\n", je->stable.oid.inode, je->stable.oid.stripe, je->stable.version);
+                printf("je_stable oid=%lx:%lx ver=%lu\n", je->stable.oid.inode, je->stable.oid.stripe, je->stable.version);
 #endif
                 // oid, version
                 obj_ver_id ov = {
                     .oid = je->stable.oid,
                     .version = je->stable.version,
                 };
-                auto it = bs->dirty_db.find(ov);
-                if (it == bs->dirty_db.end())
-                {
-                    // journal contains a legitimate STABLE entry for a non-existing dirty write
-                    // this probably means that journal was trimmed between WRITE and STABLE entries
-                    // skip it
-                }
-                else
-                {
-                    while (1)
-                    {
-                        it->second.state = (it->second.state == ST_D_META_SYNCED
-                            ? ST_D_STABLE
-                            : (it->second.state == ST_DEL_SYNCED ? ST_DEL_STABLE : ST_J_STABLE));
-                        if (it == bs->dirty_db.begin())
-                            break;
-                        it--;
-                        if (it->first.oid != ov.oid || IS_STABLE(it->second.state))
-                            break;
-                    }
-                    bs->flusher->enqueue_flush(ov);
-                }
-                auto unstab_it = bs->unstable_writes.find(ov.oid);
-                if (unstab_it != bs->unstable_writes.end() && unstab_it->second <= ov.version)
-                {
-                    bs->unstable_writes.erase(unstab_it);
-                }
+                bs->mark_stable(ov);
             }
             else if (je->type == JE_ROLLBACK)
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_rollback oid=%lu:%lu ver=%lu\n", je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version);
+                printf("je_rollback oid=%lx:%lx ver=%lu\n", je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version);
 #endif
                 // rollback dirty writes of <oid> up to <version>
-                auto it = bs->dirty_db.lower_bound((obj_ver_id){
+                obj_ver_id ov = {
                     .oid = je->rollback.oid,
-                    .version = UINT64_MAX,
-                });
-                if (it != bs->dirty_db.begin())
-                {
-                    uint64_t max_unstable = 0;
-                    auto rm_start = it;
-                    auto rm_end = it;
-                    it--;
-                    while (it->first.oid == je->rollback.oid &&
-                        it->first.version > je->rollback.version &&
-                        !IS_IN_FLIGHT(it->second.state) &&
-                        !IS_STABLE(it->second.state))
-                    {
-                        if (it->first.oid != je->rollback.oid)
-                            break;
-                        else if (it->first.version <= je->rollback.version)
-                        {
-                            if (!IS_STABLE(it->second.state))
-                                max_unstable = it->first.version;
-                            break;
-                        }
-                        else if (IS_STABLE(it->second.state))
-                            break;
-                        // Remove entry
-                        rm_start = it;
-                        if (it == bs->dirty_db.begin())
-                            break;
-                        it--;
-                    }
-                    if (rm_start != rm_end)
-                    {
-                        bs->erase_dirty(rm_start, rm_end, UINT64_MAX);
-                    }
-                    auto unstab_it = bs->unstable_writes.find(je->rollback.oid);
-                    if (unstab_it != bs->unstable_writes.end())
-                    {
-                        if (max_unstable == 0)
-                            bs->unstable_writes.erase(unstab_it);
-                        else
-                            unstab_it->second = max_unstable;
-                    }
-                }
+                    .version = je->rollback.version,
+                };
+                bs->mark_rolled_back(ov);
             }
             else if (je->type == JE_DELETE)
             {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_delete oid=%lu:%lu ver=%lu\n", je->del.oid.inode, je->del.oid.stripe, je->del.version);
+                printf("je_delete oid=%lx:%lx ver=%lu\n", je->del.oid.inode, je->del.oid.stripe, je->del.version);
 #endif
-                // oid, version
-                obj_ver_id ov = {
-                    .oid = je->del.oid,
-                    .version = je->del.version,
-                };
-                bs->dirty_db.emplace(ov, (dirty_entry){
-                    .state = ST_DEL_SYNCED,
-                    .flags = 0,
-                    .location = 0,
-                    .offset = 0,
-                    .len = 0,
-                    .journal_sector = proc_pos,
-                });
-                bs->journal.used_sectors[proc_pos]++;
+                auto clean_it = bs->clean_db.find(je->del.oid);
+                if (clean_it == bs->clean_db.end() ||
+                    clean_it->second.version < je->del.version)
+                {
+                    // oid, version
+                    obj_ver_id ov = {
+                        .oid = je->del.oid,
+                        .version = je->del.version,
+                    };
+                    bs->dirty_db.emplace(ov, (dirty_entry){
+                        .state = (BS_ST_DELETE | BS_ST_SYNCED),
+                        .flags = 0,
+                        .location = 0,
+                        .offset = 0,
+                        .len = 0,
+                        .journal_sector = proc_pos,
+                    });
+                    bs->journal.used_sectors[proc_pos]++;
+                    // Deletions are treated as immediately stable, because
+                    // "2-phase commit" (write->stabilize) isn't sufficient for them anyway
+                    bs->mark_stable(ov);
+                }
             }
             started = true;
             pos += je->size;

blockstore_init.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 class blockstore_init_meta

blockstore_journal.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 blockstore_journal_check_t::blockstore_journal_check_t(blockstore_impl_t *bs)
@@ -6,18 +9,26 @@ blockstore_journal_check_t::blockstore_journal_check_t(blockstore_impl_t *bs)
     sectors_required = 0;
     next_pos = bs->journal.next_free;
     next_sector = bs->journal.cur_sector;
+    first_sector = -1;
     next_in_pos = bs->journal.in_sector_pos;
     right_dir = next_pos >= bs->journal.used_start;
 }
 
 // Check if we can write <required> entries of <size> bytes and <data_after> data bytes after them to the journal
-int blockstore_journal_check_t::check_available(blockstore_op_t *op, int required, int size, int data_after)
+int blockstore_journal_check_t::check_available(blockstore_op_t *op, int entries_required, int size, int data_after)
 {
+    int required = entries_required;
     while (1)
     {
-        int fits = (bs->journal.block_size - next_in_pos) / size;
+        int fits = bs->journal.no_same_sector_overwrites && bs->journal.sector_info[next_sector].written
+            ? 0
+            : (bs->journal.block_size - next_in_pos) / size;
         if (fits > 0)
         {
+            if (first_sector == -1)
+            {
+                first_sector = next_sector;
+            }
             required -= fits;
             next_in_pos += fits * size;
             sectors_required++;
@@ -38,19 +49,40 @@ int blockstore_journal_check_t::check_available(blockstore_op_t *op, int require
             right_dir = false;
         }
         next_in_pos = 0;
-        if (bs->journal.sector_info[next_sector].usage_count > 0 ||
-            bs->journal.sector_info[next_sector].dirty)
+        next_sector = ((next_sector + 1) % bs->journal.sector_count);
+        if (next_sector == first_sector)
         {
-            next_sector = ((next_sector + 1) % bs->journal.sector_count);
+            // next_sector may wrap when all sectors are flushed and the incoming batch is too big
+            // This is an error condition, we can't wait for anything in this case
+            throw std::runtime_error(
+                "Blockstore journal_sector_buffer_count="+std::to_string(bs->journal.sector_count)+
+                " is too small for a batch of "+std::to_string(entries_required)+" entries of "+std::to_string(size)+" bytes"
+            );
         }
         if (bs->journal.sector_info[next_sector].usage_count > 0 ||
             bs->journal.sector_info[next_sector].dirty)
         {
             // No memory buffer available. Wait for it.
-#ifdef BLOCKSTORE_DEBUG
-            printf("next journal buffer %d is still dirty=%d used=%d\n", next_sector,
-                bs->journal.sector_info[next_sector].dirty, bs->journal.sector_info[next_sector].usage_count);
-#endif
+            int used = 0, dirty = 0;
+            for (int i = 0; i < bs->journal.sector_count; i++)
+            {
+                if (bs->journal.sector_info[i].dirty)
+                {
+                    dirty++;
+                    used++;
+                }
+                if (bs->journal.sector_info[i].usage_count > 0)
+                {
+                    used++;
+                }
+            }
+            // In fact, it's even more rare than "ran out of journal space", so print a warning
+            printf(
+                "Ran out of journal sector buffers: %d/%lu buffers used (%d dirty), next buffer (%ld) is %s and flushed %lu times\n",
+                used, bs->journal.sector_count, dirty, next_sector,
+                bs->journal.sector_info[next_sector].dirty ? "dirty" : "not dirty",
+                bs->journal.sector_info[next_sector].usage_count
+            );
             PRIV(op)->wait_for = WAIT_JOURNAL_BUFFER;
             return 0;
         }
@@ -74,7 +106,7 @@ int blockstore_journal_check_t::check_available(blockstore_op_t *op, int require
                 : bs->journal.used_start - bs->journal.next_free)
         );
         PRIV(op)->wait_for = WAIT_JOURNAL;
-        bs->flusher->force_start();
+        bs->flusher->request_trim();
         PRIV(op)->wait_detail = bs->journal.used_start;
         return 0;
     }
@@ -83,14 +115,21 @@ int blockstore_journal_check_t::check_available(blockstore_op_t *op, int require
 
 journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type, uint32_t size)
 {
-    if (journal.block_size - journal.in_sector_pos < size)
+    if (journal.block_size - journal.in_sector_pos < size ||
+        journal.no_same_sector_overwrites && journal.sector_info[journal.cur_sector].written)
     {
         assert(!journal.sector_info[journal.cur_sector].dirty);
         // Move to the next journal sector
+        journal.sector_info[journal.cur_sector].written = false;
         if (journal.sector_info[journal.cur_sector].usage_count > 0)
         {
             // Also select next sector buffer in memory
             journal.cur_sector = ((journal.cur_sector + 1) % journal.sector_count);
+            assert(!journal.sector_info[journal.cur_sector].usage_count);
+        }
+        else
+        {
+            journal.dirty_start = journal.next_free;
         }
         journal.sector_info[journal.cur_sector].offset = journal.next_free;
         journal.in_sector_pos = 0;
@@ -116,6 +155,7 @@ journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type,
 void prepare_journal_sector_write(journal_t & journal, int cur_sector, io_uring_sqe *sqe, std::function<void(ring_data_t*)> cb)
 {
     journal.sector_info[cur_sector].dirty = false;
+    journal.sector_info[cur_sector].written = true;
     journal.sector_info[cur_sector].usage_count++;
     ring_data_t *data = ((ring_data_t*)sqe->user_data);
     data->iov = (struct iovec){
@@ -126,9 +166,8 @@ void prepare_journal_sector_write(journal_t & journal, int cur_sector, io_uring_
     };
     data->callback = cb;
     my_uring_prep_writev(
-        sqe, journal.fd_index, &data->iov, 1, journal.offset + journal.sector_info[cur_sector].offset
+        sqe, journal.fd, &data->iov, 1, journal.offset + journal.sector_info[cur_sector].offset
     );
-    sqe->flags |= IOSQE_FIXED_FILE;
 }
 
 journal_t::~journal_t()
@@ -149,8 +188,8 @@ bool journal_t::trim()
     auto journal_used_it = used_sectors.lower_bound(used_start);
 #ifdef BLOCKSTORE_DEBUG
     printf(
-        "Trimming journal (used_start=%lu, next_free=%lu, first_used=%lu, usage_count=%lu)\n",
-        used_start, next_free,
+        "Trimming journal (used_start=%08lx, next_free=%08lx, dirty_start=%08lx, new_start=%08lx, new_refcount=%ld)\n",
+        used_start, next_free, dirty_start,
         journal_used_it == used_sectors.end() ? 0 : journal_used_it->first,
         journal_used_it == used_sectors.end() ? 0 : journal_used_it->second
     );
@@ -181,7 +220,7 @@ bool journal_t::trim()
         return false;
     }
 #ifdef BLOCKSTORE_DEBUG
-    printf("Journal trimmed to %lu (next_free=%lu)\n", used_start, next_free);
+    printf("Journal trimmed to %08lx (next_free=%08lx)\n", used_start, next_free);
 #endif
     return true;
 }

blockstore_journal.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include "crc32c.h"
@@ -12,12 +15,16 @@
 // Journal entries
 // Journal entries are linked to each other by their crc32 value
 // The journal is almost a blockchain, because object versions constantly increase
+#define JE_MIN         0x01
 #define JE_START       0x01
 #define JE_SMALL_WRITE 0x02
 #define JE_BIG_WRITE   0x03
 #define JE_STABLE      0x04
 #define JE_DELETE      0x05
 #define JE_ROLLBACK    0x06
+#define JE_SMALL_WRITE_INSTANT 0x07
+#define JE_BIG_WRITE_INSTANT   0x08
+#define JE_MAX         0x08
 
 // crc32c comes first to ease calculation and is equal to crc32()
 struct __attribute__((__packed__)) journal_entry_start
@@ -125,26 +132,32 @@ struct journal_sector_info_t
 {
     uint64_t offset;
     uint64_t usage_count;
+    bool written;
     bool dirty;
 };
 
 struct journal_t
 {
-    int fd, fd_index;
+    int fd;
     uint64_t device_size;
     bool inmemory = false;
     void *buffer = NULL;
 
-    uint64_t block_size = 512;
+    uint64_t block_size;
     uint64_t offset, len;
+    // Next free block offset
     uint64_t next_free = 0;
+    // First occupied block offset
     uint64_t used_start = 0;
+    // End of the last block not used for writing anymore
+    uint64_t dirty_start = 0;
     uint32_t crc32_last = 0;
 
     // Current sector(s) used for writing
     void *sector_buf = NULL;
     journal_sector_info_t *sector_info = NULL;
     uint64_t sector_count;
+    bool no_same_sector_overwrites = false;
     int cur_sector = 0;
     int in_sector_pos = 0;
 
@@ -160,7 +173,7 @@ struct blockstore_journal_check_t
 {
     blockstore_impl_t *bs;
     uint64_t next_pos, next_sector, next_in_pos;
-    int sectors_required;
+    int sectors_required, first_sector;
     bool right_dir; // writing to the end or the beginning of the ring buffer
 
     blockstore_journal_check_t(blockstore_impl_t *bs);

blockstore_open.cpp

@@ -1,3 +1,7 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include <sys/file.h>
 #include "blockstore_impl.h"
 
 static uint32_t is_power_of_two(uint64_t value)
@@ -34,10 +38,23 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     {
         disable_journal_fsync = true;
     }
+    if (config["disable_device_lock"] == "true" || config["disable_device_lock"] == "1" || config["disable_device_lock"] == "yes")
+    {
+        disable_flock = true;
+    }
+    if (config["immediate_commit"] == "all")
+    {
+        immediate_commit = IMMEDIATE_ALL;
+    }
+    else if (config["immediate_commit"] == "small")
+    {
+        immediate_commit = IMMEDIATE_SMALL;
+    }
     metadata_buf_size = strtoull(config["meta_buf_size"].c_str(), NULL, 10);
     cfg_journal_size = strtoull(config["journal_size"].c_str(), NULL, 10);
     data_device = config["data_device"];
     data_offset = strtoull(config["data_offset"].c_str(), NULL, 10);
+    cfg_data_size = strtoull(config["data_size"].c_str(), NULL, 10);
     meta_device = config["meta_device"];
     meta_offset = strtoull(config["meta_offset"].c_str(), NULL, 10);
     block_size = strtoull(config["block_size"].c_str(), NULL, 10);
@@ -45,6 +62,8 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     journal_device = config["journal_device"];
     journal.offset = strtoull(config["journal_offset"].c_str(), NULL, 10);
     journal.sector_count = strtoull(config["journal_sector_buffer_count"].c_str(), NULL, 10);
+    journal.no_same_sector_overwrites = config["journal_no_same_sector_overwrites"] == "true" ||
+        config["journal_no_same_sector_overwrites"] == "1" || config["journal_no_same_sector_overwrites"] == "yes";
     journal.inmemory = config["inmemory_journal"] != "false";
     disk_alignment = strtoull(config["disk_alignment"].c_str(), NULL, 10);
     journal_block_size = strtoull(config["journal_block_size"].c_str(), NULL, 10);
@@ -66,7 +85,7 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     }
     if (!disk_alignment)
     {
-        disk_alignment = 512;
+        disk_alignment = 4096;
     }
     else if (disk_alignment % MEM_ALIGNMENT)
     {
@@ -74,7 +93,7 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     }
     if (!journal_block_size)
     {
-        journal_block_size = 512;
+        journal_block_size = 4096;
     }
     else if (journal_block_size % MEM_ALIGNMENT)
     {
@@ -82,7 +101,7 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     }
     if (!meta_block_size)
     {
-        meta_block_size = 512;
+        meta_block_size = 4096;
     }
     else if (meta_block_size % MEM_ALIGNMENT)
     {
@@ -128,6 +147,22 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
     {
         metadata_buf_size = 4*1024*1024;
     }
+    if (meta_device == "")
+    {
+        disable_meta_fsync = disable_data_fsync;
+    }
+    if (journal_device == "")
+    {
+        disable_journal_fsync = disable_meta_fsync;
+    }
+    if (immediate_commit != IMMEDIATE_NONE && !disable_journal_fsync)
+    {
+        throw std::runtime_error("immediate_commit requires disable_journal_fsync");
+    }
+    if (immediate_commit == IMMEDIATE_ALL && !disable_data_fsync)
+    {
+        throw std::runtime_error("immediate_commit=all requires disable_journal_fsync and disable_data_fsync");
+    }
     // init some fields
     clean_entry_bitmap_size = block_size / bitmap_granularity / 8;
     clean_entry_size = sizeof(clean_disk_entry) + clean_entry_bitmap_size;
@@ -140,10 +175,6 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
 
 void blockstore_impl_t::calc_lengths()
 {
-    // register fds
-    data_fd_index = ringloop->register_fd(data_fd);
-    meta_fd_index = meta_fd == data_fd ? data_fd_index : ringloop->register_fd(meta_fd);
-    journal.fd_index = journal_fd_index = journal.fd == meta_fd ? meta_fd_index : ringloop->register_fd(journal.fd);
     // data
     data_len = data_size - data_offset;
     if (data_fd == meta_fd && data_offset < meta_offset)
@@ -155,6 +186,15 @@ void blockstore_impl_t::calc_lengths()
         data_len = data_len < journal.offset-data_offset
             ? data_len : journal.offset-data_offset;
     }
+    if (cfg_data_size != 0)
+    {
+        if (data_len < cfg_data_size)
+        {
+            throw std::runtime_error("Data area ("+std::to_string(data_len)+
+                " bytes) is less than configured size ("+std::to_string(cfg_data_size)+" bytes)");
+        }
+        data_len = cfg_data_size;
+    }
     // meta
     meta_area = (meta_fd == data_fd ? data_size : meta_size) - meta_offset;
     if (meta_fd == data_fd && meta_offset <= data_offset)
@@ -256,6 +296,10 @@ void blockstore_impl_t::open_data()
     {
         throw std::runtime_error("data_offset exceeds device size = "+std::to_string(data_size));
     }
+    if (!disable_flock && flock(data_fd, LOCK_EX|LOCK_NB) != 0)
+    {
+        throw std::runtime_error(std::string("Failed to lock data device: ") + strerror(errno));
+    }
 }
 
 void blockstore_impl_t::open_meta()
@@ -273,11 +317,14 @@ void blockstore_impl_t::open_meta()
         {
             throw std::runtime_error("meta_offset exceeds device size = "+std::to_string(meta_size));
         }
+        if (!disable_flock && flock(meta_fd, LOCK_EX|LOCK_NB) != 0)
+        {
+            throw std::runtime_error(std::string("Failed to lock metadata device: ") + strerror(errno));
+        }
     }
     else
     {
         meta_fd = data_fd;
-        disable_meta_fsync = disable_data_fsync;
         meta_size = 0;
         if (meta_offset >= data_size)
         {
@@ -295,12 +342,15 @@ void blockstore_impl_t::open_journal()
         {
             throw std::runtime_error("Failed to open journal device");
         }
-        check_size(journal.fd, &journal.device_size, "metadata device");
+        check_size(journal.fd, &journal.device_size, "journal device");
+        if (!disable_flock && flock(journal.fd, LOCK_EX|LOCK_NB) != 0)
+        {
+            throw std::runtime_error(std::string("Failed to lock journal device: ") + strerror(errno));
+        }
     }
     else
     {
         journal.fd = meta_fd;
-        disable_journal_fsync = disable_meta_fsync;
         journal.device_size = 0;
         if (journal.offset >= data_size)
         {

blockstore_read.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_t offset, uint64_t len,
@@ -8,12 +11,10 @@ int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_
         // Zero-length version - skip
         return 1;
     }
-    if (IS_IN_FLIGHT(item_state))
+    else if (IS_IN_FLIGHT(item_state))
     {
-        // Pause until it's written somewhere
-        PRIV(op)->wait_for = WAIT_IN_FLIGHT;
-        PRIV(op)->wait_detail = item_version;
-        return 0;
+        // Write not finished yet - skip
+        return 1;
     }
     else if (IS_DELETE(item_state))
     {
@@ -31,15 +32,15 @@ int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_
     PRIV(op)->pending_ops++;
     my_uring_prep_readv(
         sqe,
-        IS_JOURNAL(item_state) ? journal_fd_index : data_fd_index,
+        IS_JOURNAL(item_state) ? journal.fd : data_fd,
         &data->iov, 1,
         (IS_JOURNAL(item_state) ? journal.offset : data_offset) + offset
     );
-    sqe->flags |= IOSQE_FIXED_FILE;
     data->callback = [this, op](ring_data_t *data) { handle_read_event(data, op); };
     return 1;
 }
 
+// FIXME I've seen a bug here so I want some tests
 int blockstore_impl_t::fulfill_read(blockstore_op_t *read_op, uint64_t &fulfilled, uint32_t item_start, uint32_t item_end,
     uint32_t item_state, uint64_t item_version, uint64_t item_location)
 {
@@ -52,8 +53,20 @@ int blockstore_impl_t::fulfill_read(blockstore_op_t *read_op, uint64_t &fulfille
         while (1)
         {
             for (; it != PRIV(read_op)->read_vec.end(); it++)
+            {
                 if (it->offset >= cur_start)
+                {
                     break;
+                }
+                else if (it->offset + it->len > cur_start)
+                {
+                    cur_start = it->offset + it->len;
+                    if (cur_start >= item_end)
+                    {
+                        goto endwhile;
+                    }
+                }
+            }
             if (it == PRIV(read_op)->read_vec.end() || it->offset > cur_start)
             {
                 fulfill_read_t el = {
@@ -72,9 +85,12 @@ int blockstore_impl_t::fulfill_read(blockstore_op_t *read_op, uint64_t &fulfille
             }
             cur_start = it->offset + it->len;
             if (it == PRIV(read_op)->read_vec.end() || cur_start >= item_end)
+            {
                 break;
+            }
         }
     }
+endwhile:
     return 1;
 }
 
@@ -134,63 +150,67 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
             dirty_it--;
         }
     }
-    if (clean_it != clean_db.end() && fulfilled < read_op->len)
+    if (clean_it != clean_db.end())
     {
         if (!result_version)
         {
             result_version = clean_it->second.version;
         }
-        if (!clean_entry_bitmap_size)
+        if (fulfilled < read_op->len)
         {
-            if (!fulfill_read(read_op, fulfilled, 0, block_size, ST_CURRENT, 0, clean_it->second.location))
+            if (!clean_entry_bitmap_size)
             {
-                // need to wait. undo added requests, don't dequeue op
-                PRIV(read_op)->read_vec.clear();
-                return 0;
-            }
-        }
-        else
-        {
-            uint64_t meta_loc = clean_it->second.location >> block_order;
-            uint8_t *clean_entry_bitmap;
-            if (inmemory_meta)
-            {
-                uint64_t sector = (meta_loc / (meta_block_size / clean_entry_size)) * meta_block_size;
-                uint64_t pos = (meta_loc % (meta_block_size / clean_entry_size));
-                clean_entry_bitmap = (uint8_t*)(metadata_buffer + sector + pos*clean_entry_size + sizeof(clean_disk_entry));
+                if (!fulfill_read(read_op, fulfilled, 0, block_size, (BS_ST_BIG_WRITE | BS_ST_STABLE), 0, clean_it->second.location))
+                {
+                    // need to wait. undo added requests, don't dequeue op
+                    PRIV(read_op)->read_vec.clear();
+                    return 0;
+                }
             }
             else
             {
-                clean_entry_bitmap = (uint8_t*)(clean_bitmap + meta_loc*clean_entry_bitmap_size);
-            }
-            uint64_t bmp_start = 0, bmp_end = 0, bmp_size = block_size/bitmap_granularity;
-            while (bmp_start < bmp_size)
-            {
-                while (!(clean_entry_bitmap[bmp_end >> 3] & (1 << (bmp_end & 0x7))) && bmp_end < bmp_size)
+                uint64_t meta_loc = clean_it->second.location >> block_order;
+                uint8_t *clean_entry_bitmap;
+                if (inmemory_meta)
                 {
-                    bmp_end++;
+                    uint64_t sector = (meta_loc / (meta_block_size / clean_entry_size)) * meta_block_size;
+                    uint64_t pos = (meta_loc % (meta_block_size / clean_entry_size));
+                    clean_entry_bitmap = (uint8_t*)(metadata_buffer + sector + pos*clean_entry_size + sizeof(clean_disk_entry));
                 }
-                if (bmp_end > bmp_start)
+                else
                 {
-                    // fill with zeroes
-                    fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
-                        bmp_end * bitmap_granularity, ST_DEL_STABLE, 0, 0);
+                    clean_entry_bitmap = (uint8_t*)(clean_bitmap + meta_loc*clean_entry_bitmap_size);
                 }
-                bmp_start = bmp_end;
-                while (clean_entry_bitmap[bmp_end >> 3] & (1 << (bmp_end & 0x7)) && bmp_end < bmp_size)
+                uint64_t bmp_start = 0, bmp_end = 0, bmp_size = block_size/bitmap_granularity;
+                while (bmp_start < bmp_size)
                 {
-                    bmp_end++;
-                }
-                if (bmp_end > bmp_start)
-                {
-                    if (!fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
-                        bmp_end * bitmap_granularity, ST_CURRENT, 0, clean_it->second.location + bmp_start * bitmap_granularity))
+                    while (!(clean_entry_bitmap[bmp_end >> 3] & (1 << (bmp_end & 0x7))) && bmp_end < bmp_size)
                     {
-                        // need to wait. undo added requests, don't dequeue op
-                        PRIV(read_op)->read_vec.clear();
-                        return 0;
+                        bmp_end++;
+                    }
+                    if (bmp_end > bmp_start)
+                    {
+                        // fill with zeroes
+                        fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
+                            bmp_end * bitmap_granularity, (BS_ST_DELETE | BS_ST_STABLE), 0, 0);
                     }
                     bmp_start = bmp_end;
+                    while (clean_entry_bitmap[bmp_end >> 3] & (1 << (bmp_end & 0x7)) && bmp_end < bmp_size)
+                    {
+                        bmp_end++;
+                    }
+                    if (bmp_end > bmp_start)
+                    {
+                        if (!fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
+                            bmp_end * bitmap_granularity, (BS_ST_BIG_WRITE | BS_ST_STABLE), 0,
+                            clean_it->second.location + bmp_start * bitmap_granularity))
+                        {
+                            // need to wait. undo added requests, don't dequeue op
+                            PRIV(read_op)->read_vec.clear();
+                            return 0;
+                        }
+                        bmp_start = bmp_end;
+                    }
                 }
             }
         }
@@ -198,7 +218,7 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
     else if (fulfilled < read_op->len)
     {
         // fill remaining parts with zeroes
-        fulfill_read(read_op, fulfilled, 0, block_size, ST_DEL_STABLE, 0, 0);
+        fulfill_read(read_op, fulfilled, 0, block_size, (BS_ST_DELETE | BS_ST_STABLE), 0, 0);
     }
     assert(fulfilled == read_op->len);
     read_op->version = result_version;

blockstore_rollback.cpp

@@ -1,7 +1,14 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
 {
+    if (PRIV(op)->op_state)
+    {
+        return continue_rollback(op);
+    }
     obj_ver_id* v;
     int i, todo = op->len;
     for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
@@ -14,8 +21,13 @@ int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
         });
         if (dirty_it == dirty_db.begin())
         {
+            if (v->version == 0)
+            {
+                // Already rolled back
+                // FIXME Skip this object version
+            }
         bad_op:
-            op->retval = -EINVAL;
+            op->retval = -ENOENT;
             FINISH_OP(op);
             return 1;
         }
@@ -31,7 +43,9 @@ int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
                 if (!IS_SYNCED(dirty_it->second.state) ||
                     IS_STABLE(dirty_it->second.state))
                 {
-                    goto bad_op;
+                    op->retval = -EBUSY;
+                    FINISH_OP(op);
+                    return 1;
                 }
                 if (dirty_it == dirty_db.begin())
                 {
@@ -60,39 +74,12 @@ int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
         journal.sector_info[journal.cur_sector].dirty)
     {
         if (cur_sector == -1)
-            PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+            PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
         cur_sector = journal.cur_sector;
         prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
     }
     for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
     {
-        // FIXME This is here only for the purpose of tracking unstable_writes. Remove if not required
-        // FIXME ...aaaand this is similar to blockstore_init.cpp - maybe dedup it?
-        auto dirty_it = dirty_db.lower_bound((obj_ver_id){
-            .oid = v->oid,
-            .version = UINT64_MAX,
-        });
-        uint64_t max_unstable = 0;
-        while (dirty_it != dirty_db.begin())
-        {
-            dirty_it--;
-            if (dirty_it->first.oid != v->oid)
-                break;
-            else if (dirty_it->first.version <= v->version)
-            {
-                if (!IS_STABLE(dirty_it->second.state))
-                    max_unstable = dirty_it->first.version;
-                break;
-            }
-        }
-        auto unstab_it = unstable_writes.find(v->oid);
-        if (unstab_it != unstable_writes.end())
-        {
-            if (max_unstable == 0)
-                unstable_writes.erase(unstab_it);
-            else
-                unstab_it->second = max_unstable;
-        }
         journal_entry_rollback *je = (journal_entry_rollback*)
             prefill_single_journal_entry(journal, JE_ROLLBACK, sizeof(journal_entry_rollback));
         journal.sector_info[journal.cur_sector].dirty = false;
@@ -103,21 +90,117 @@ int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
         if (cur_sector != journal.cur_sector)
         {
             if (cur_sector == -1)
-                PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+                PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
             cur_sector = journal.cur_sector;
             prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
         }
     }
-    PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
+    PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
     PRIV(op)->pending_ops = s;
+    PRIV(op)->op_state = 1;
+    inflight_writes++;
     return 1;
 }
 
+int blockstore_impl_t::continue_rollback(blockstore_op_t *op)
+{
+    if (PRIV(op)->op_state == 2)
+        goto resume_2;
+    else if (PRIV(op)->op_state == 3)
+        goto resume_3;
+    else if (PRIV(op)->op_state == 5)
+        goto resume_5;
+    else
+        return 1;
+resume_2:
+    // Release used journal sectors
+    release_journal_sectors(op);
+resume_3:
+    if (!disable_journal_fsync)
+    {
+        io_uring_sqe *sqe = get_sqe();
+        if (!sqe)
+        {
+            return 0;
+        }
+        ring_data_t *data = ((ring_data_t*)sqe->user_data);
+        my_uring_prep_fsync(sqe, journal.fd, IORING_FSYNC_DATASYNC);
+        data->iov = { 0 };
+        data->callback = [this, op](ring_data_t *data) { handle_rollback_event(data, op); };
+        PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
+        PRIV(op)->pending_ops = 1;
+        PRIV(op)->op_state = 4;
+        return 1;
+    }
+resume_5:
+    obj_ver_id* v;
+    int i;
+    for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
+    {
+        mark_rolled_back(*v);
+    }
+    journal.trim();
+    inflight_writes--;
+    // Acknowledge op
+    op->retval = 0;
+    FINISH_OP(op);
+    return 1;
+}
+
+void blockstore_impl_t::mark_rolled_back(const obj_ver_id & ov)
+{
+    auto it = dirty_db.lower_bound((obj_ver_id){
+        .oid = ov.oid,
+        .version = UINT64_MAX,
+    });
+    if (it != dirty_db.begin())
+    {
+        uint64_t max_unstable = 0;
+        auto rm_start = it;
+        auto rm_end = it;
+        it--;
+        while (it->first.oid == ov.oid &&
+            it->first.version > ov.version &&
+            !IS_IN_FLIGHT(it->second.state) &&
+            !IS_STABLE(it->second.state))
+        {
+            if (it->first.oid != ov.oid)
+                break;
+            else if (it->first.version <= ov.version)
+            {
+                if (!IS_STABLE(it->second.state))
+                    max_unstable = it->first.version;
+                break;
+            }
+            else if (IS_STABLE(it->second.state))
+                break;
+            // Remove entry
+            rm_start = it;
+            if (it == dirty_db.begin())
+                break;
+            it--;
+        }
+        if (rm_start != rm_end)
+        {
+            erase_dirty(rm_start, rm_end, UINT64_MAX);
+        }
+        auto unstab_it = unstable_writes.find(ov.oid);
+        if (unstab_it != unstable_writes.end())
+        {
+            if (max_unstable == 0)
+                unstable_writes.erase(unstab_it);
+            else
+                unstab_it->second = max_unstable;
+        }
+    }
+}
+
 void blockstore_impl_t::handle_rollback_event(ring_data_t *data, blockstore_op_t *op)
 {
     live = true;
     if (data->res != data->iov.iov_len)
     {
+        inflight_writes--;
         throw std::runtime_error(
             "write operation failed ("+std::to_string(data->res)+" != "+std::to_string(data->iov.iov_len)+
             "). in-memory state is corrupted. AAAAAAAaaaaaaaaa!!!111"
@@ -126,37 +209,11 @@ void blockstore_impl_t::handle_rollback_event(ring_data_t *data, blockstore_op_t
     PRIV(op)->pending_ops--;
     if (PRIV(op)->pending_ops == 0)
     {
-        // Release used journal sectors
-        release_journal_sectors(op);
-        obj_ver_id* v;
-        int i;
-        for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
+        PRIV(op)->op_state++;
+        if (!continue_rollback(op))
         {
-            // Erase dirty_db entries
-            auto rm_end = dirty_db.lower_bound((obj_ver_id){
-                .oid = v->oid,
-                .version = UINT64_MAX,
-            });
-            rm_end--;
-            auto rm_start = rm_end;
-            while (1)
-            {
-                if (rm_end->first.oid != v->oid)
-                    break;
-                else if (rm_end->first.version <= v->version)
-                    break;
-                rm_start = rm_end;
-                if (rm_end == dirty_db.begin())
-                    break;
-                rm_end--;
-            }
-            if (rm_end != rm_start)
-                erase_dirty(rm_start, rm_end, UINT64_MAX);
+            submit_queue.push_front(op);
         }
-        journal.trim();
-        // Acknowledge op
-        op->retval = 0;
-        FINISH_OP(op);
     }
 }
 
@@ -173,11 +230,13 @@ void blockstore_impl_t::erase_dirty(blockstore_dirty_db_t::iterator dirty_start,
 #endif
             data_alloc->set(dirty_it->second.location >> block_order, false);
         }
-#ifdef BLOCKSTORE_DEBUG
-        printf("remove usage of journal offset %lu by %lu:%lu v%lu\n", dirty_it->second.journal_sector,
-            dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version);
-#endif
         int used = --journal.used_sectors[dirty_it->second.journal_sector];
+#ifdef BLOCKSTORE_DEBUG
+        printf(
+            "remove usage of journal offset %08lx by %lx:%lx v%lu (%d refs)\n", dirty_it->second.journal_sector,
+            dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version, used
+        );
+#endif
         if (used == 0)
         {
             journal.used_sectors.erase(dirty_it->second.journal_sector);

blockstore_stable.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 // Stabilize small write:
@@ -40,6 +43,10 @@
 
 int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
 {
+    if (PRIV(op)->op_state)
+    {
+        return continue_stable(op);
+    }
     obj_ver_id* v;
     int i, todo = 0;
     for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
@@ -51,7 +58,7 @@ int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
             if (clean_it == clean_db.end() || clean_it->second.version < v->version)
             {
                 // No such object version
-                op->retval = -EINVAL;
+                op->retval = -ENOENT;
                 FINISH_OP(op);
                 return 1;
             }
@@ -60,10 +67,10 @@ int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
                 // Already stable
             }
         }
-        else if (IS_UNSYNCED(dirty_it->second.state))
+        else if (!IS_SYNCED(dirty_it->second.state))
         {
             // Object not synced yet. Caller must sync it first
-            op->retval = EAGAIN;
+            op->retval = -EBUSY;
             FINISH_OP(op);
             return 1;
         }
@@ -98,18 +105,13 @@ int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
         journal.sector_info[journal.cur_sector].dirty)
     {
         if (cur_sector == -1)
-            PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+            PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
         cur_sector = journal.cur_sector;
         prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
     }
     for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
     {
-        auto unstab_it = unstable_writes.find(v->oid);
-        if (unstab_it != unstable_writes.end() &&
-            unstab_it->second <= v->version)
-        {
-            unstable_writes.erase(unstab_it);
-        }
+        // FIXME: Only stabilize versions that aren't stable yet
         journal_entry_stable *je = (journal_entry_stable*)
             prefill_single_journal_entry(journal, JE_STABLE, sizeof(journal_entry_stable));
         journal.sector_info[journal.cur_sector].dirty = false;
@@ -120,21 +122,108 @@ int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
         if (cur_sector != journal.cur_sector)
         {
             if (cur_sector == -1)
-                PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+                PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
             cur_sector = journal.cur_sector;
             prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
         }
     }
-    PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
+    PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
     PRIV(op)->pending_ops = s;
+    PRIV(op)->op_state = 1;
+    inflight_writes++;
     return 1;
 }
 
+int blockstore_impl_t::continue_stable(blockstore_op_t *op)
+{
+    if (PRIV(op)->op_state == 2)
+        goto resume_2;
+    else if (PRIV(op)->op_state == 3)
+        goto resume_3;
+    else if (PRIV(op)->op_state == 5)
+        goto resume_5;
+    else
+        return 1;
+resume_2:
+    // Release used journal sectors
+    release_journal_sectors(op);
+resume_3:
+    if (!disable_journal_fsync)
+    {
+        io_uring_sqe *sqe = get_sqe();
+        if (!sqe)
+        {
+            return 0;
+        }
+        ring_data_t *data = ((ring_data_t*)sqe->user_data);
+        my_uring_prep_fsync(sqe, journal.fd, IORING_FSYNC_DATASYNC);
+        data->iov = { 0 };
+        data->callback = [this, op](ring_data_t *data) { handle_stable_event(data, op); };
+        PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
+        PRIV(op)->pending_ops = 1;
+        PRIV(op)->op_state = 4;
+        return 1;
+    }
+resume_5:
+    // Mark dirty_db entries as stable, acknowledge op completion
+    obj_ver_id* v;
+    int i;
+    for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
+    {
+        // Mark all dirty_db entries up to op->version as stable
+        mark_stable(*v);
+    }
+    inflight_writes--;
+    // Acknowledge op
+    op->retval = 0;
+    FINISH_OP(op);
+    return 1;
+}
+
+void blockstore_impl_t::mark_stable(const obj_ver_id & v)
+{
+    auto dirty_it = dirty_db.find(v);
+    if (dirty_it != dirty_db.end())
+    {
+        while (1)
+        {
+            if ((dirty_it->second.state & BS_ST_WORKFLOW_MASK) == BS_ST_SYNCED)
+            {
+                dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_STABLE;
+            }
+            else if (IS_STABLE(dirty_it->second.state))
+            {
+                break;
+            }
+            if (dirty_it == dirty_db.begin())
+            {
+                break;
+            }
+            dirty_it--;
+            if (dirty_it->first.oid != v.oid)
+            {
+                break;
+            }
+        }
+#ifdef BLOCKSTORE_DEBUG
+        printf("enqueue_flush %lx:%lx v%lu\n", v.oid.inode, v.oid.stripe, v.version);
+#endif
+        flusher->enqueue_flush(v);
+    }
+    auto unstab_it = unstable_writes.find(v.oid);
+    if (unstab_it != unstable_writes.end() &&
+        unstab_it->second <= v.version)
+    {
+        unstable_writes.erase(unstab_it);
+    }
+}
+
 void blockstore_impl_t::handle_stable_event(ring_data_t *data, blockstore_op_t *op)
 {
     live = true;
     if (data->res != data->iov.iov_len)
     {
+        inflight_writes--;
         throw std::runtime_error(
             "write operation failed ("+std::to_string(data->res)+" != "+std::to_string(data->iov.iov_len)+
             "). in-memory state is corrupted. AAAAAAAaaaaaaaaa!!!111"
@@ -143,53 +232,10 @@ void blockstore_impl_t::handle_stable_event(ring_data_t *data, blockstore_op_t *
     PRIV(op)->pending_ops--;
     if (PRIV(op)->pending_ops == 0)
     {
-        // Release used journal sectors
-        release_journal_sectors(op);
-        // Mark dirty_db entries as stable, acknowledge op completion
-        obj_ver_id* v;
-        int i;
-        for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
+        PRIV(op)->op_state++;
+        if (!continue_stable(op))
         {
-            // Mark all dirty_db entries up to op->version as stable
-            auto dirty_it = dirty_db.find(*v);
-            if (dirty_it != dirty_db.end())
-            {
-                while (1)
-                {
-                    if (dirty_it->second.state == ST_J_SYNCED)
-                    {
-                        dirty_it->second.state = ST_J_STABLE;
-                    }
-                    else if (dirty_it->second.state == ST_D_META_SYNCED)
-                    {
-                        dirty_it->second.state = ST_D_STABLE;
-                    }
-                    else if (dirty_it->second.state == ST_DEL_SYNCED)
-                    {
-                        dirty_it->second.state = ST_DEL_STABLE;
-                    }
-                    else if (IS_STABLE(dirty_it->second.state))
-                    {
-                        break;
-                    }
-                    if (dirty_it == dirty_db.begin())
-                    {
-                        break;
-                    }
-                    dirty_it--;
-                    if (dirty_it->first.oid != v->oid)
-                    {
-                        break;
-                    }
-                }
-#ifdef BLOCKSTORE_DEBUG
-                printf("enqueue_flush %lu:%lu v%lu\n", v->oid.inode, v->oid.stripe, v->version);
-#endif
-                flusher->enqueue_flush(*v);
-            }
+            submit_queue.push_front(op);
         }
-        // Acknowledge op
-        op->retval = 0;
-        FINISH_OP(op);
     }
 }

blockstore_sync.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 #define SYNC_HAS_SMALL 1
@@ -11,7 +14,7 @@
 
 int blockstore_impl_t::dequeue_sync(blockstore_op_t *op)
 {
-    if (PRIV(op)->sync_state == 0)
+    if (PRIV(op)->op_state == 0)
     {
         stop_sync_submitted = false;
         PRIV(op)->sync_big_writes.swap(unsynced_big_writes);
@@ -21,11 +24,11 @@ int blockstore_impl_t::dequeue_sync(blockstore_op_t *op)
         unsynced_big_writes.clear();
         unsynced_small_writes.clear();
         if (PRIV(op)->sync_big_writes.size() > 0)
-            PRIV(op)->sync_state = SYNC_HAS_BIG;
+            PRIV(op)->op_state = SYNC_HAS_BIG;
         else if (PRIV(op)->sync_small_writes.size() > 0)
-            PRIV(op)->sync_state = SYNC_HAS_SMALL;
+            PRIV(op)->op_state = SYNC_HAS_SMALL;
         else
-            PRIV(op)->sync_state = SYNC_DONE;
+            PRIV(op)->op_state = SYNC_DONE;
         // Always add sync to in_progress_syncs because we clear unsynced_big_writes and unsynced_small_writes
         PRIV(op)->prev_sync_count = in_progress_syncs.size();
         PRIV(op)->in_progress_ptr = in_progress_syncs.insert(in_progress_syncs.end(), op);
@@ -38,7 +41,7 @@ int blockstore_impl_t::dequeue_sync(blockstore_op_t *op)
 int blockstore_impl_t::continue_sync(blockstore_op_t *op)
 {
     auto cb = [this, op](ring_data_t *data) { handle_sync_event(data, op); };
-    if (PRIV(op)->sync_state == SYNC_HAS_SMALL)
+    if (PRIV(op)->op_state == SYNC_HAS_SMALL)
     {
         // No big writes, just fsync the journal
         for (; PRIV(op)->sync_small_checked < PRIV(op)->sync_small_writes.size(); PRIV(op)->sync_small_checked++)
@@ -54,17 +57,17 @@ int blockstore_impl_t::continue_sync(blockstore_op_t *op)
             // Write out the last journal sector if it happens to be dirty
             BS_SUBMIT_GET_ONLY_SQE(sqe);
             prepare_journal_sector_write(journal, journal.cur_sector, sqe, cb);
-            PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
+            PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
             PRIV(op)->pending_ops = 1;
-            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_SENT;
+            PRIV(op)->op_state = SYNC_JOURNAL_WRITE_SENT;
             return 1;
         }
         else
         {
-            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_DONE;
+            PRIV(op)->op_state = SYNC_JOURNAL_WRITE_DONE;
         }
     }
-    if (PRIV(op)->sync_state == SYNC_HAS_BIG)
+    if (PRIV(op)->op_state == SYNC_HAS_BIG)
     {
         for (; PRIV(op)->sync_big_checked < PRIV(op)->sync_big_writes.size(); PRIV(op)->sync_big_checked++)
         {
@@ -78,21 +81,20 @@ int blockstore_impl_t::continue_sync(blockstore_op_t *op)
         if (!disable_data_fsync)
         {
             BS_SUBMIT_GET_SQE(sqe, data);
-            my_uring_prep_fsync(sqe, data_fd_index, IORING_FSYNC_DATASYNC);
-            sqe->flags |= IOSQE_FIXED_FILE;
+            my_uring_prep_fsync(sqe, data_fd, IORING_FSYNC_DATASYNC);
             data->iov = { 0 };
             data->callback = cb;
-            PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 0;
+            PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
             PRIV(op)->pending_ops = 1;
-            PRIV(op)->sync_state = SYNC_DATA_SYNC_SENT;
+            PRIV(op)->op_state = SYNC_DATA_SYNC_SENT;
             return 1;
         }
         else
         {
-            PRIV(op)->sync_state = SYNC_DATA_SYNC_DONE;
+            PRIV(op)->op_state = SYNC_DATA_SYNC_DONE;
         }
     }
-    if (PRIV(op)->sync_state == SYNC_DATA_SYNC_DONE)
+    if (PRIV(op)->op_state == SYNC_DATA_SYNC_DONE)
     {
         for (; PRIV(op)->sync_small_checked < PRIV(op)->sync_small_writes.size(); PRIV(op)->sync_small_checked++)
         {
@@ -122,19 +124,25 @@ int blockstore_impl_t::continue_sync(blockstore_op_t *op)
             journal.sector_info[journal.cur_sector].dirty)
         {
             if (cur_sector == -1)
-                PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+                PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
             cur_sector = journal.cur_sector;
             prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
         }
         while (it != PRIV(op)->sync_big_writes.end())
         {
-            journal_entry_big_write *je = (journal_entry_big_write*)
-                prefill_single_journal_entry(journal, JE_BIG_WRITE, sizeof(journal_entry_big_write));
+            journal_entry_big_write *je = (journal_entry_big_write*)prefill_single_journal_entry(
+                journal, (dirty_db[*it].state & BS_ST_INSTANT) ? JE_BIG_WRITE_INSTANT : JE_BIG_WRITE,
+                sizeof(journal_entry_big_write)
+            );
             dirty_db[*it].journal_sector = journal.sector_info[journal.cur_sector].offset;
             journal.sector_info[journal.cur_sector].dirty = false;
             journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
 #ifdef BLOCKSTORE_DEBUG
-            printf("journal offset %lu is used by %lu:%lu v%lu\n", dirty_db[*it].journal_sector, it->oid.inode, it->oid.stripe, it->version);
+            printf(
+                "journal offset %08lx is used by %lx:%lx v%lu (%lu refs)\n",
+                dirty_db[*it].journal_sector, it->oid.inode, it->oid.stripe, it->version,
+                journal.used_sectors[journal.sector_info[journal.cur_sector].offset]
+            );
 #endif
             je->oid = it->oid;
             je->version = it->version;
@@ -147,37 +155,36 @@ int blockstore_impl_t::continue_sync(blockstore_op_t *op)
             if (cur_sector != journal.cur_sector)
             {
                 if (cur_sector == -1)
-                    PRIV(op)->min_used_journal_sector = 1 + journal.cur_sector;
+                    PRIV(op)->min_flushed_journal_sector = 1 + journal.cur_sector;
                 cur_sector = journal.cur_sector;
                 prepare_journal_sector_write(journal, cur_sector, sqe[s++], cb);
             }
         }
-        PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
+        PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
         PRIV(op)->pending_ops = s;
-        PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_SENT;
+        PRIV(op)->op_state = SYNC_JOURNAL_WRITE_SENT;
         return 1;
     }
-    if (PRIV(op)->sync_state == SYNC_JOURNAL_WRITE_DONE)
+    if (PRIV(op)->op_state == SYNC_JOURNAL_WRITE_DONE)
     {
         if (!disable_journal_fsync)
         {
             BS_SUBMIT_GET_SQE(sqe, data);
-            my_uring_prep_fsync(sqe, journal_fd_index, IORING_FSYNC_DATASYNC);
-            sqe->flags |= IOSQE_FIXED_FILE;
+            my_uring_prep_fsync(sqe, journal.fd, IORING_FSYNC_DATASYNC);
             data->iov = { 0 };
             data->callback = cb;
             PRIV(op)->pending_ops = 1;
-            PRIV(op)->sync_state = SYNC_JOURNAL_SYNC_SENT;
+            PRIV(op)->op_state = SYNC_JOURNAL_SYNC_SENT;
             return 1;
         }
         else
         {
-            PRIV(op)->sync_state = SYNC_DONE;
+            PRIV(op)->op_state = SYNC_DONE;
         }
     }
-    if (PRIV(op)->sync_state == SYNC_DONE)
+    if (PRIV(op)->op_state == SYNC_DONE)
     {
-        ack_sync(op);
+        return ack_sync(op);
     }
     return 1;
 }
@@ -198,17 +205,17 @@ void blockstore_impl_t::handle_sync_event(ring_data_t *data, blockstore_op_t *op
         // Release used journal sectors
         release_journal_sectors(op);
         // Handle states
-        if (PRIV(op)->sync_state == SYNC_DATA_SYNC_SENT)
+        if (PRIV(op)->op_state == SYNC_DATA_SYNC_SENT)
         {
-            PRIV(op)->sync_state = SYNC_DATA_SYNC_DONE;
+            PRIV(op)->op_state = SYNC_DATA_SYNC_DONE;
         }
-        else if (PRIV(op)->sync_state == SYNC_JOURNAL_WRITE_SENT)
+        else if (PRIV(op)->op_state == SYNC_JOURNAL_WRITE_SENT)
         {
-            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_DONE;
+            PRIV(op)->op_state = SYNC_JOURNAL_WRITE_DONE;
         }
-        else if (PRIV(op)->sync_state == SYNC_JOURNAL_SYNC_SENT)
+        else if (PRIV(op)->op_state == SYNC_JOURNAL_SYNC_SENT)
         {
-            PRIV(op)->sync_state = SYNC_DONE;
+            PRIV(op)->op_state = SYNC_DONE;
             ack_sync(op);
         }
         else
@@ -220,7 +227,7 @@ void blockstore_impl_t::handle_sync_event(ring_data_t *data, blockstore_op_t *op
 
 int blockstore_impl_t::ack_sync(blockstore_op_t *op)
 {
-    if (PRIV(op)->sync_state == SYNC_DONE && PRIV(op)->prev_sync_count == 0)
+    if (PRIV(op)->op_state == SYNC_DONE && PRIV(op)->prev_sync_count == 0)
     {
         // Remove dependency of subsequent syncs
         auto it = PRIV(op)->in_progress_ptr;
@@ -232,14 +239,14 @@ int blockstore_impl_t::ack_sync(blockstore_op_t *op)
         {
             auto & next_sync = *it++;
             PRIV(next_sync)->prev_sync_count -= done_syncs;
-            if (PRIV(next_sync)->prev_sync_count == 0 && PRIV(next_sync)->sync_state == SYNC_DONE)
+            if (PRIV(next_sync)->prev_sync_count == 0 && PRIV(next_sync)->op_state == SYNC_DONE)
             {
                 done_syncs++;
                 // Acknowledge next_sync
                 ack_one_sync(next_sync);
             }
         }
-        return 1;
+        return 2;
     }
     return 0;
 }
@@ -250,20 +257,47 @@ void blockstore_impl_t::ack_one_sync(blockstore_op_t *op)
     for (auto it = PRIV(op)->sync_big_writes.begin(); it != PRIV(op)->sync_big_writes.end(); it++)
     {
 #ifdef BLOCKSTORE_DEBUG
-        printf("Ack sync big %lu:%lu v%lu\n", it->oid.inode, it->oid.stripe, it->version);
+        printf("Ack sync big %lx:%lx v%lu\n", it->oid.inode, it->oid.stripe, it->version);
 #endif
         auto & unstab = unstable_writes[it->oid];
         unstab = unstab < it->version ? it->version : unstab;
-        dirty_db[*it].state = ST_D_META_SYNCED;
+        auto dirty_it = dirty_db.find(*it);
+        dirty_it->second.state = ((dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_SYNCED);
+        if (dirty_it->second.state & BS_ST_INSTANT)
+        {
+            mark_stable(dirty_it->first);
+        }
+        dirty_it++;
+        while (dirty_it != dirty_db.end() && dirty_it->first.oid == it->oid)
+        {
+            if ((dirty_it->second.state & BS_ST_WORKFLOW_MASK) == BS_ST_WAIT_BIG)
+            {
+                dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_IN_FLIGHT;
+            }
+            dirty_it++;
+        }
     }
     for (auto it = PRIV(op)->sync_small_writes.begin(); it != PRIV(op)->sync_small_writes.end(); it++)
     {
 #ifdef BLOCKSTORE_DEBUG
-        printf("Ack sync small %lu:%lu v%lu\n", it->oid.inode, it->oid.stripe, it->version);
+        printf("Ack sync small %lx:%lx v%lu\n", it->oid.inode, it->oid.stripe, it->version);
 #endif
         auto & unstab = unstable_writes[it->oid];
         unstab = unstab < it->version ? it->version : unstab;
-        dirty_db[*it].state = dirty_db[*it].state == ST_DEL_WRITTEN ? ST_DEL_SYNCED : ST_J_SYNCED;
+        if (dirty_db[*it].state == (BS_ST_DELETE | BS_ST_WRITTEN))
+        {
+            dirty_db[*it].state = (BS_ST_DELETE | BS_ST_SYNCED);
+            // Deletions are treated as immediately stable
+            mark_stable(*it);
+        }
+        else /* (BS_ST_INSTANT?) | BS_ST_SMALL_WRITE | BS_ST_WRITTEN */
+        {
+            dirty_db[*it].state = (dirty_db[*it].state & ~BS_ST_WORKFLOW_MASK) | BS_ST_SYNCED;
+            if (dirty_db[*it].state & BS_ST_INSTANT)
+            {
+                mark_stable(*it);
+            }
+        }
     }
     in_progress_syncs.erase(PRIV(op)->in_progress_ptr);
     op->retval = 0;

blockstore_write.cpp

@@ -1,9 +1,13 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "blockstore_impl.h"
 
 bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
 {
     // Check or assign version number
     bool found = false, deleted = false, is_del = (op->opcode == BS_OP_DELETE);
+    bool is_inflight_big = false;
     uint64_t version = 1;
     if (dirty_db.size() > 0)
     {
@@ -17,6 +21,9 @@ bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
             found = true;
             version = dirty_it->first.version + 1;
             deleted = IS_DELETE(dirty_it->second.state);
+            is_inflight_big = (dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_BIG_WRITE
+                ? !IS_SYNCED(dirty_it->second.state)
+                : ((dirty_it->second.state & BS_ST_WORKFLOW_MASK) == BS_ST_WAIT_BIG);
         }
     }
     if (!found)
@@ -38,7 +45,7 @@ bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
     else if (op->version < version)
     {
         // Invalid version requested
-        op->retval = -EINVAL;
+        op->retval = -EEXIST;
         return false;
     }
     if (deleted && is_del)
@@ -47,18 +54,36 @@ bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
         op->retval = 0;
         return false;
     }
-    // Immediately add the operation into dirty_db, so subsequent reads could see it
+    if (is_inflight_big && !is_del && !deleted && op->len < block_size &&
+        immediate_commit != IMMEDIATE_ALL)
+    {
+        // Issue an additional sync so that the previous big write can reach the journal
+        blockstore_op_t *sync_op = new blockstore_op_t;
+        sync_op->opcode = BS_OP_SYNC;
+        sync_op->callback = [this, op](blockstore_op_t *sync_op)
+        {
+            delete sync_op;
+        };
+        enqueue_op(sync_op);
+    }
 #ifdef BLOCKSTORE_DEBUG
-    printf("%s %lu:%lu v%lu\n", is_del ? "Delete" : "Write", op->oid.inode, op->oid.stripe, op->version);
+    if (is_del)
+        printf("Delete %lx:%lx v%lu\n", op->oid.inode, op->oid.stripe, op->version);
+    else
+        printf("Write %lx:%lx v%lu offset=%u len=%u\n", op->oid.inode, op->oid.stripe, op->version, op->offset, op->len);
 #endif
+    // No strict need to add it into dirty_db here, it's just left
+    // from the previous implementation where reads waited for writes
     dirty_db.emplace((obj_ver_id){
         .oid = op->oid,
         .version = op->version,
     }, (dirty_entry){
         .state = (uint32_t)(
             is_del
-                ? ST_DEL_IN_FLIGHT
-                : (op->len == block_size || deleted ? ST_D_IN_FLIGHT : ST_J_IN_FLIGHT)
+                ? (BS_ST_DELETE | BS_ST_IN_FLIGHT)
+                : (op->opcode == BS_OP_WRITE_STABLE ? BS_ST_INSTANT : 0) | (op->len == block_size || deleted
+                    ? (BS_ST_BIG_WRITE | BS_ST_IN_FLIGHT)
+                    : (is_inflight_big ? (BS_ST_SMALL_WRITE | BS_ST_WAIT_BIG) : (BS_ST_SMALL_WRITE | BS_ST_IN_FLIGHT)))
         ),
         .flags = 0,
         .location = 0,
@@ -72,11 +97,21 @@ bool blockstore_impl_t::enqueue_write(blockstore_op_t *op)
 // First step of the write algorithm: dequeue operation and submit initial write(s)
 int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
 {
+    if (PRIV(op)->op_state)
+    {
+        return continue_write(op);
+    }
     auto dirty_it = dirty_db.find((obj_ver_id){
         .oid = op->oid,
         .version = op->version,
     });
-    if (dirty_it->second.state == ST_D_IN_FLIGHT)
+    assert(dirty_it != dirty_db.end());
+    if ((dirty_it->second.state & BS_ST_WORKFLOW_MASK) == BS_ST_WAIT_BIG)
+    {
+        // Don't dequeue
+        return 0;
+    }
+    else if ((dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_BIG_WRITE)
     {
         blockstore_journal_check_t space_check(this);
         if (!space_check.check_available(op, unsynced_big_writes.size() + 1, sizeof(journal_entry_big_write), JOURNAL_STABILIZE_RESERVATION))
@@ -100,7 +135,7 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         }
         BS_SUBMIT_GET_SQE(sqe, data);
         dirty_it->second.location = loc << block_order;
-        dirty_it->second.state = ST_D_SUBMITTED;
+        dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_SUBMITTED;
 #ifdef BLOCKSTORE_DEBUG
         printf("Allocate block %lu\n", loc);
 #endif
@@ -122,18 +157,25 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         data->iov.iov_len = op->len + stripe_offset + stripe_end; // to check it in the callback
         data->callback = [this, op](ring_data_t *data) { handle_write_event(data, op); };
         my_uring_prep_writev(
-            sqe, data_fd_index, PRIV(op)->iov_zerofill, vcnt, data_offset + (loc << block_order) + op->offset - stripe_offset
+            sqe, data_fd, PRIV(op)->iov_zerofill, vcnt, data_offset + (loc << block_order) + op->offset - stripe_offset
         );
-        sqe->flags |= IOSQE_FIXED_FILE;
         PRIV(op)->pending_ops = 1;
-        PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 0;
-        // Remember big write as unsynced
-        unsynced_big_writes.push_back((obj_ver_id){
-            .oid = op->oid,
-            .version = op->version,
-        });
+        PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
+        if (immediate_commit != IMMEDIATE_ALL)
+        {
+            // Remember big write as unsynced
+            unsynced_big_writes.push_back((obj_ver_id){
+                .oid = op->oid,
+                .version = op->version,
+            });
+            PRIV(op)->op_state = 3;
+        }
+        else
+        {
+            PRIV(op)->op_state = 1;
+        }
     }
-    else
+    else /* if ((dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_SMALL_WRITE) */
     {
         // Small (journaled) write
         // First check if the journal has sufficient space
@@ -145,10 +187,11 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         }
         // There is sufficient space. Get SQE(s)
         struct io_uring_sqe *sqe1 = NULL;
-        if ((journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_small_write) &&
+        if (immediate_commit != IMMEDIATE_NONE ||
+            (journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_small_write) &&
             journal.sector_info[journal.cur_sector].dirty)
         {
-            // Write current journal sector only if it's dirty and full
+            // Write current journal sector only if it's dirty and full, or in the immediate_commit mode
             BS_SUBMIT_GET_SQE_DECL(sqe1);
         }
         struct io_uring_sqe *sqe2 = NULL;
@@ -158,24 +201,32 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         }
         // Got SQEs. Prepare previous journal sector write if required
         auto cb = [this, op](ring_data_t *data) { handle_write_event(data, op); };
-        if (sqe1)
+        if (immediate_commit == IMMEDIATE_NONE)
         {
-            prepare_journal_sector_write(journal, journal.cur_sector, sqe1, cb);
-            // FIXME rename to min/max _flushing
-            PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
-            PRIV(op)->pending_ops++;
-        }
-        else
-        {
-            PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 0;
+            if (sqe1)
+            {
+                prepare_journal_sector_write(journal, journal.cur_sector, sqe1, cb);
+                PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
+                PRIV(op)->pending_ops++;
+            }
+            else
+            {
+                PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
+            }
         }
         // Then pre-fill journal entry
-        journal_entry_small_write *je = (journal_entry_small_write*)
-            prefill_single_journal_entry(journal, JE_SMALL_WRITE, sizeof(journal_entry_small_write));
+        journal_entry_small_write *je = (journal_entry_small_write*)prefill_single_journal_entry(
+            journal, op->opcode == BS_OP_WRITE_STABLE ? JE_SMALL_WRITE_INSTANT : JE_SMALL_WRITE,
+            sizeof(journal_entry_small_write)
+        );
         dirty_it->second.journal_sector = journal.sector_info[journal.cur_sector].offset;
         journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
 #ifdef BLOCKSTORE_DEBUG
-        printf("journal offset %lu is used by %lu:%lu v%lu\n", dirty_it->second.journal_sector, dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version);
+        printf(
+            "journal offset %08lx is used by %lx:%lx v%lu (%lu refs)\n",
+            dirty_it->second.journal_sector, dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version,
+            journal.used_sectors[journal.sector_info[journal.cur_sector].offset]
+        );
 #endif
         // Figure out where data will be
         journal.next_free = (journal.next_free + op->len) <= journal.len ? journal.next_free : journal_block_size;
@@ -187,6 +238,12 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
         je->crc32_data = crc32c(0, op->buf, op->len);
         je->crc32 = je_crc32((journal_entry*)je);
         journal.crc32_last = je->crc32;
+        if (immediate_commit != IMMEDIATE_NONE)
+        {
+            prepare_journal_sector_write(journal, journal.cur_sector, sqe1, cb);
+            PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
+            PRIV(op)->pending_ops++;
+        }
         if (op->len > 0)
         {
             // Prepare journal data write
@@ -199,9 +256,8 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
             data2->iov = (struct iovec){ op->buf, op->len };
             data2->callback = cb;
             my_uring_prep_writev(
-                sqe2, journal_fd_index, &data2->iov, 1, journal.offset + journal.next_free
+                sqe2, journal.fd, &data2->iov, 1, journal.offset + journal.next_free
             );
-            sqe2->flags |= IOSQE_FIXED_FILE;
             PRIV(op)->pending_ops++;
         }
         else
@@ -209,22 +265,119 @@ int blockstore_impl_t::dequeue_write(blockstore_op_t *op)
             // Zero-length overwrite. Allowed to bump object version in EC placement groups without actually writing data
         }
         dirty_it->second.location = journal.next_free;
-        dirty_it->second.state = ST_J_SUBMITTED;
+        dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_SUBMITTED;
         journal.next_free += op->len;
         if (journal.next_free >= journal.len)
         {
             journal.next_free = journal_block_size;
         }
-        // Remember small write as unsynced
-        unsynced_small_writes.push_back((obj_ver_id){
-            .oid = op->oid,
-            .version = op->version,
-        });
+        if (immediate_commit == IMMEDIATE_NONE)
+        {
+            // Remember small write as unsynced
+            unsynced_small_writes.push_back((obj_ver_id){
+                .oid = op->oid,
+                .version = op->version,
+            });
+        }
         if (!PRIV(op)->pending_ops)
         {
-            ack_write(op);
+            PRIV(op)->op_state = 4;
+            continue_write(op);
+        }
+        else
+        {
+            PRIV(op)->op_state = 3;
         }
     }
+    inflight_writes++;
+    return 1;
+}
+
+int blockstore_impl_t::continue_write(blockstore_op_t *op)
+{
+    io_uring_sqe *sqe = NULL;
+    journal_entry_big_write *je;
+    auto dirty_it = dirty_db.find((obj_ver_id){
+        .oid = op->oid,
+        .version = op->version,
+    });
+    assert(dirty_it != dirty_db.end());
+    if (PRIV(op)->op_state == 2)
+        goto resume_2;
+    else if (PRIV(op)->op_state == 4)
+        goto resume_4;
+    else
+        return 1;
+resume_2:
+    // Only for the immediate_commit mode: prepare and submit big_write journal entry
+    sqe = get_sqe();
+    if (!sqe)
+    {
+        return 0;
+    }
+    je = (journal_entry_big_write*)prefill_single_journal_entry(
+        journal, op->opcode == BS_OP_WRITE_STABLE ? JE_BIG_WRITE_INSTANT : JE_BIG_WRITE,
+        sizeof(journal_entry_big_write)
+    );
+    dirty_it->second.journal_sector = journal.sector_info[journal.cur_sector].offset;
+    journal.sector_info[journal.cur_sector].dirty = false;
+    journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
+#ifdef BLOCKSTORE_DEBUG
+    printf(
+        "journal offset %08lx is used by %lx:%lx v%lu (%lu refs)\n",
+        journal.sector_info[journal.cur_sector].offset, op->oid.inode, op->oid.stripe, op->version,
+        journal.used_sectors[journal.sector_info[journal.cur_sector].offset]
+    );
+#endif
+    je->oid = op->oid;
+    je->version = op->version;
+    je->offset = op->offset;
+    je->len = op->len;
+    je->location = dirty_it->second.location;
+    je->crc32 = je_crc32((journal_entry*)je);
+    journal.crc32_last = je->crc32;
+    prepare_journal_sector_write(journal, journal.cur_sector, sqe,
+        [this, op](ring_data_t *data) { handle_write_event(data, op); });
+    PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
+    PRIV(op)->pending_ops = 1;
+    PRIV(op)->op_state = 3;
+    return 1;
+resume_4:
+    // Switch object state
+#ifdef BLOCKSTORE_DEBUG
+    printf("Ack write %lx:%lx v%lu = %d\n", op->oid.inode, op->oid.stripe, op->version, dirty_it->second.state);
+#endif
+    bool imm = (dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_BIG_WRITE
+        ? (immediate_commit == IMMEDIATE_ALL)
+        : (immediate_commit != IMMEDIATE_NONE);
+    if (imm)
+    {
+        auto & unstab = unstable_writes[op->oid];
+        unstab = unstab < op->version ? op->version : unstab;
+    }
+    dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK)
+        | (imm ? BS_ST_SYNCED : BS_ST_WRITTEN);
+    if (imm && ((dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_DELETE || (dirty_it->second.state & BS_ST_INSTANT)))
+    {
+        // Deletions are treated as immediately stable
+        mark_stable(dirty_it->first);
+    }
+    if (immediate_commit == IMMEDIATE_ALL)
+    {
+        dirty_it++;
+        while (dirty_it != dirty_db.end() && dirty_it->first.oid == op->oid)
+        {
+            if ((dirty_it->second.state & BS_ST_WORKFLOW_MASK) == BS_ST_WAIT_BIG)
+            {
+                dirty_it->second.state = (dirty_it->second.state & ~BS_ST_WORKFLOW_MASK) | BS_ST_IN_FLIGHT;
+            }
+            dirty_it++;
+        }
+    }
+    inflight_writes--;
+    // Acknowledge write
+    op->retval = op->len;
+    FINISH_OP(op);
     return 1;
 }
 
@@ -233,6 +386,7 @@ void blockstore_impl_t::handle_write_event(ring_data_t *data, blockstore_op_t *o
     live = true;
     if (data->res != data->iov.iov_len)
     {
+        inflight_writes--;
         // FIXME: our state becomes corrupted after a write error. maybe do something better than just die
         throw std::runtime_error(
             "write operation failed ("+std::to_string(data->res)+" != "+std::to_string(data->iov.iov_len)+
@@ -243,88 +397,118 @@ void blockstore_impl_t::handle_write_event(ring_data_t *data, blockstore_op_t *o
     if (PRIV(op)->pending_ops == 0)
     {
         release_journal_sectors(op);
-        ack_write(op);
+        PRIV(op)->op_state++;
+        if (!continue_write(op))
+        {
+            submit_queue.push_front(op);
+        }
     }
 }
 
 void blockstore_impl_t::release_journal_sectors(blockstore_op_t *op)
 {
-    // Release used journal sectors
-    if (PRIV(op)->min_used_journal_sector > 0 &&
-        PRIV(op)->max_used_journal_sector > 0)
+    // Release flushed journal sectors
+    if (PRIV(op)->min_flushed_journal_sector > 0 &&
+        PRIV(op)->max_flushed_journal_sector > 0)
     {
-        uint64_t s = PRIV(op)->min_used_journal_sector;
+        uint64_t s = PRIV(op)->min_flushed_journal_sector;
         while (1)
         {
             journal.sector_info[s-1].usage_count--;
-            if (s == PRIV(op)->max_used_journal_sector)
+            if (s != (1+journal.cur_sector) && journal.sector_info[s-1].usage_count == 0)
+            {
+                // We know for sure that we won't write into this sector anymore
+                uint64_t new_ds = journal.sector_info[s-1].offset + journal.block_size;
+                if (new_ds >= journal.len)
+                {
+                    new_ds = journal.block_size;
+                }
+                if ((journal.dirty_start + (journal.dirty_start >= journal.used_start ? 0 : journal.len)) <
+                    (new_ds + (new_ds >= journal.used_start ? 0 : journal.len)))
+                {
+                    journal.dirty_start = new_ds;
+                }
+            }
+            if (s == PRIV(op)->max_flushed_journal_sector)
                 break;
             s = 1 + s % journal.sector_count;
         }
-        PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 0;
+        PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
     }
 }
 
-void blockstore_impl_t::ack_write(blockstore_op_t *op)
-{
-    // Switch object state
-    auto & dirty_entry = dirty_db[(obj_ver_id){
-        .oid = op->oid,
-        .version = op->version,
-    }];
-#ifdef BLOCKSTORE_DEBUG
-    printf("Ack write %lu:%lu v%lu = %d\n", op->oid.inode, op->oid.stripe, op->version, dirty_entry.state);
-#endif
-    if (dirty_entry.state == ST_J_SUBMITTED)
-    {
-        dirty_entry.state = ST_J_WRITTEN;
-    }
-    else if (dirty_entry.state == ST_D_SUBMITTED)
-    {
-        dirty_entry.state = ST_D_WRITTEN;
-    }
-    else if (dirty_entry.state == ST_DEL_SUBMITTED)
-    {
-        dirty_entry.state = ST_DEL_WRITTEN;
-    }
-    // Acknowledge write without sync
-    op->retval = op->len;
-    FINISH_OP(op);
-}
-
 int blockstore_impl_t::dequeue_del(blockstore_op_t *op)
 {
     auto dirty_it = dirty_db.find((obj_ver_id){
         .oid = op->oid,
         .version = op->version,
     });
+    assert(dirty_it != dirty_db.end());
     blockstore_journal_check_t space_check(this);
     if (!space_check.check_available(op, 1, sizeof(journal_entry_del), 0))
     {
         return 0;
     }
-    BS_SUBMIT_GET_ONLY_SQE(sqe);
+    io_uring_sqe *sqe = NULL;
+    if (immediate_commit != IMMEDIATE_NONE ||
+        (journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_del) &&
+        journal.sector_info[journal.cur_sector].dirty)
+    {
+        // Write current journal sector only if it's dirty and full, or in the immediate_commit mode
+        BS_SUBMIT_GET_SQE_DECL(sqe);
+    }
+    auto cb = [this, op](ring_data_t *data) { handle_write_event(data, op); };
     // Prepare journal sector write
-    journal_entry_del *je = (journal_entry_del*)
-        prefill_single_journal_entry(journal, JE_DELETE, sizeof(struct journal_entry_del));
+    if (immediate_commit == IMMEDIATE_NONE)
+    {
+        if (sqe)
+        {
+            prepare_journal_sector_write(journal, journal.cur_sector, sqe, cb);
+            PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
+            PRIV(op)->pending_ops++;
+        }
+        else
+        {
+            PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 0;
+        }
+    }
+    // Pre-fill journal entry
+    journal_entry_del *je = (journal_entry_del*)prefill_single_journal_entry(
+        journal, JE_DELETE, sizeof(struct journal_entry_del)
+    );
     dirty_it->second.journal_sector = journal.sector_info[journal.cur_sector].offset;
     journal.used_sectors[journal.sector_info[journal.cur_sector].offset]++;
 #ifdef BLOCKSTORE_DEBUG
-    printf("journal offset %lu is used by %lu:%lu v%lu\n", dirty_it->second.journal_sector, dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version);
+    printf(
+        "journal offset %08lx is used by %lx:%lx v%lu (%lu refs)\n",
+        dirty_it->second.journal_sector, dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version,
+        journal.used_sectors[journal.sector_info[journal.cur_sector].offset]
+    );
 #endif
     je->oid = op->oid;
     je->version = op->version;
     je->crc32 = je_crc32((journal_entry*)je);
     journal.crc32_last = je->crc32;
-    auto cb = [this, op](ring_data_t *data) { handle_write_event(data, op); };
-    prepare_journal_sector_write(journal, journal.cur_sector, sqe, cb);
-    PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_journal_sector = 1 + journal.cur_sector;
-    PRIV(op)->pending_ops = 1;
-    dirty_it->second.state = ST_DEL_SUBMITTED;
-    // Remember small write as unsynced
-    unsynced_small_writes.push_back((obj_ver_id){
-        .oid = op->oid,
-        .version = op->version,
-    });
+    dirty_it->second.state = BS_ST_DELETE | BS_ST_SUBMITTED;
+    if (immediate_commit != IMMEDIATE_NONE)
+    {
+        prepare_journal_sector_write(journal, journal.cur_sector, sqe, cb);
+        PRIV(op)->min_flushed_journal_sector = PRIV(op)->max_flushed_journal_sector = 1 + journal.cur_sector;
+        PRIV(op)->pending_ops++;
+        // Remember small write as unsynced
+        unsynced_small_writes.push_back((obj_ver_id){
+            .oid = op->oid,
+            .version = op->version,
+        });
+    }
+    if (!PRIV(op)->pending_ops)
+    {
+        PRIV(op)->op_state = 4;
+        continue_write(op);
+    }
+    else
+    {
+        PRIV(op)->op_state = 3;
+    }
     return 1;
 }

cluster_client.cpp

@@ -0,0 +1,745 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "cluster_client.h"
+
+cluster_client_t::cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd, json11::Json & config)
+{
+    this->ringloop = ringloop;
+    this->tfd = tfd;
+
+    msgr.osd_num = 0;
+    msgr.tfd = tfd;
+    msgr.ringloop = ringloop;
+    msgr.repeer_pgs = [this](osd_num_t peer_osd)
+    {
+        if (msgr.osd_peer_fds.find(peer_osd) != msgr.osd_peer_fds.end())
+        {
+            // peer_osd just connected
+            continue_ops();
+        }
+        else if (unsynced_writes.size())
+        {
+            // peer_osd just dropped connection
+            for (auto op: syncing_writes)
+            {
+                for (auto & part: op->parts)
+                {
+                    if (part.osd_num == peer_osd && part.done)
+                    {
+                        // repeat this operation
+                        part.osd_num = 0;
+                        part.done = false;
+                        assert(!part.sent);
+                        op->done_count--;
+                    }
+                }
+            }
+            for (auto op: unsynced_writes)
+            {
+                for (auto & part: op->parts)
+                {
+                    if (part.osd_num == peer_osd && part.done)
+                    {
+                        // repeat this operation
+                        part.osd_num = 0;
+                        part.done = false;
+                        assert(!part.sent);
+                        op->done_count--;
+                    }
+                }
+                if (op->done_count < op->parts.size())
+                {
+                    cur_ops.insert(op);
+                }
+            }
+            continue_ops();
+        }
+    };
+    msgr.exec_op = [this](osd_op_t *op)
+    {
+        // Garbage in
+        printf("Incoming garbage from peer %d\n", op->peer_fd);
+        msgr.stop_client(op->peer_fd);
+        delete op;
+    };
+    msgr.use_sync_send_recv = config["use_sync_send_recv"].bool_value() ||
+        config["use_sync_send_recv"].uint64_value();
+
+    st_cli.tfd = tfd;
+    st_cli.on_load_config_hook = [this](json11::Json::object & cfg) { on_load_config_hook(cfg); };
+    st_cli.on_change_osd_state_hook = [this](uint64_t peer_osd) { on_change_osd_state_hook(peer_osd); };
+    st_cli.on_change_hook = [this](json11::Json::object & changes) { on_change_hook(changes); };
+    st_cli.on_load_pgs_hook = [this](bool success) { on_load_pgs_hook(success); };
+
+    log_level = config["log_level"].int64_value();
+    st_cli.parse_config(config);
+    st_cli.load_global_config();
+
+    if (ringloop)
+    {
+        consumer.loop = [this]()
+        {
+            msgr.read_requests();
+            msgr.send_replies();
+            this->ringloop->submit();
+        };
+        ringloop->register_consumer(&consumer);
+    }
+}
+
+cluster_client_t::~cluster_client_t()
+{
+    if (ringloop)
+    {
+        ringloop->unregister_consumer(&consumer);
+    }
+}
+
+void cluster_client_t::stop()
+{
+    while (msgr.clients.size() > 0)
+    {
+        msgr.stop_client(msgr.clients.begin()->first);
+    }
+}
+
+void cluster_client_t::continue_ops(bool up_retry)
+{
+    for (auto op_it = cur_ops.begin(); op_it != cur_ops.end(); )
+    {
+        if ((*op_it)->up_wait)
+        {
+            if (up_retry)
+            {
+                (*op_it)->up_wait = false;
+                continue_rw(*op_it++);
+            }
+            else
+                op_it++;
+        }
+        else
+            continue_rw(*op_it++);
+    }
+}
+
+static uint32_t is_power_of_two(uint64_t value)
+{
+    uint32_t l = 0;
+    while (value > 1)
+    {
+        if (value & 1)
+        {
+            return 64;
+        }
+        value = value >> 1;
+        l++;
+    }
+    return l;
+}
+
+void cluster_client_t::on_load_config_hook(json11::Json::object & config)
+{
+    bs_block_size = config["block_size"].uint64_value();
+    bs_disk_alignment = config["disk_alignment"].uint64_value();
+    bs_bitmap_granularity = config["bitmap_granularity"].uint64_value();
+    if (!bs_block_size)
+    {
+        bs_block_size = DEFAULT_BLOCK_SIZE;
+    }
+    if (!bs_disk_alignment)
+    {
+        bs_disk_alignment = DEFAULT_DISK_ALIGNMENT;
+    }
+    if (!bs_bitmap_granularity)
+    {
+        bs_bitmap_granularity = DEFAULT_BITMAP_GRANULARITY;
+    }
+    uint32_t block_order;
+    if ((block_order = is_power_of_two(bs_block_size)) >= 64 || bs_block_size < MIN_BLOCK_SIZE || bs_block_size >= MAX_BLOCK_SIZE)
+    {
+        throw std::runtime_error("Bad block size");
+    }
+    if (config["immediate_commit"] == "all")
+    {
+        // Cluster-wide immediate_commit mode
+        immediate_commit = true;
+    }
+    else if (config.find("client_dirty_limit") != config.end())
+    {
+        client_dirty_limit = config["client_dirty_limit"].uint64_value();
+    }
+    if (!client_dirty_limit)
+    {
+        client_dirty_limit = DEFAULT_CLIENT_DIRTY_LIMIT;
+    }
+    up_wait_retry_interval = config["up_wait_retry_interval"].uint64_value();
+    if (!up_wait_retry_interval)
+    {
+        up_wait_retry_interval = 500;
+    }
+    else if (up_wait_retry_interval < 50)
+    {
+        up_wait_retry_interval = 50;
+    }
+    msgr.peer_connect_interval = config["peer_connect_interval"].uint64_value();
+    if (!msgr.peer_connect_interval)
+    {
+        msgr.peer_connect_interval = DEFAULT_PEER_CONNECT_INTERVAL;
+    }
+    msgr.peer_connect_timeout = config["peer_connect_timeout"].uint64_value();
+    if (!msgr.peer_connect_timeout)
+    {
+        msgr.peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT;
+    }
+    st_cli.start_etcd_watcher();
+    st_cli.load_pgs();
+}
+
+void cluster_client_t::on_load_pgs_hook(bool success)
+{
+    for (auto pool_item: st_cli.pool_config)
+    {
+        pg_counts[pool_item.first] = pool_item.second.real_pg_count;
+    }
+    for (auto op: offline_ops)
+    {
+        execute(op);
+    }
+    offline_ops.clear();
+    continue_ops();
+}
+
+void cluster_client_t::on_change_hook(json11::Json::object & changes)
+{
+    for (auto pool_item: st_cli.pool_config)
+    {
+        if (pg_counts[pool_item.first] != pool_item.second.real_pg_count)
+        {
+            // At this point, all pool operations should have been suspended
+            // And now they have to be resliced!
+            for (auto op: cur_ops)
+            {
+                if (INODE_POOL(op->inode) == pool_item.first)
+                {
+                    op->needs_reslice = true;
+                }
+            }
+            for (auto op: unsynced_writes)
+            {
+                if (INODE_POOL(op->inode) == pool_item.first)
+                {
+                    op->needs_reslice = true;
+                }
+            }
+            for (auto op: syncing_writes)
+            {
+                if (INODE_POOL(op->inode) == pool_item.first)
+                {
+                    op->needs_reslice = true;
+                }
+            }
+            pg_counts[pool_item.first] = pool_item.second.real_pg_count;
+        }
+    }
+    continue_ops();
+}
+
+void cluster_client_t::on_change_osd_state_hook(uint64_t peer_osd)
+{
+    if (msgr.wanted_peers.find(peer_osd) != msgr.wanted_peers.end())
+    {
+        msgr.connect_peer(peer_osd, st_cli.peer_states[peer_osd]);
+    }
+}
+
+/**
+ * How writes are synced when immediate_commit is false
+ *
+ * 1) accept up to <client_dirty_limit> write operations for execution,
+ *    queue all subsequent writes into <next_writes>
+ * 2) accept exactly one SYNC, queue all subsequent SYNCs into <next_writes>, too
+ * 3) "continue" all accepted writes
+ *
+ * "Continue" WRITE:
+ * 1) if the operation is not a copy yet - copy it (required for replay)
+ * 2) if the operation is not sliced yet - slice it
+ * 3) if the operation doesn't require reslice - try to connect & send all remaining parts
+ * 4) if any of them fail due to disconnected peers or PGs not up, repeat after reconnecting or small timeout
+ * 5) if any of them fail due to other errors, fail the operation and forget it from the current "unsynced batch"
+ * 6) if PG count changes before all parts are done, wait for all in-progress parts to finish,
+ *    throw all results away, reslice and resubmit op
+ * 7) when all parts are done, try to "continue" the current SYNC
+ * 8) if the operation succeeds, but then some OSDs drop their connections, repeat
+ *    parts from the current "unsynced batch" previously sent to those OSDs in any order
+ *
+ * "Continue" current SYNC:
+ * 1) take all unsynced operations from the current batch
+ * 2) check if all affected OSDs are still alive
+ * 3) if yes, send all SYNCs. otherwise, leave current SYNC as is.
+ * 4) if any of them fail due to disconnected peers, repeat SYNC after repeating all writes
+ * 5) if any of them fail due to other errors, fail the SYNC operation
+ */
+
+void cluster_client_t::execute(cluster_op_t *op)
+{
+    if (!bs_disk_alignment)
+    {
+        // We're offline
+        offline_ops.push_back(op);
+        return;
+    }
+    op->retval = 0;
+    if (op->opcode != OSD_OP_SYNC && op->opcode != OSD_OP_READ && op->opcode != OSD_OP_WRITE ||
+        (op->opcode == OSD_OP_READ || op->opcode == OSD_OP_WRITE) && (!op->inode || !op->len ||
+        op->offset % bs_disk_alignment || op->len % bs_disk_alignment))
+    {
+        op->retval = -EINVAL;
+        std::function<void(cluster_op_t*)>(op->callback)(op);
+        return;
+    }
+    if (op->opcode == OSD_OP_SYNC)
+    {
+        execute_sync(op);
+        return;
+    }
+    if (op->opcode == OSD_OP_WRITE && !immediate_commit)
+    {
+        if (next_writes.size() > 0)
+        {
+            assert(cur_sync);
+            next_writes.push_back(op);
+            return;
+        }
+        if (queued_bytes >= client_dirty_limit)
+        {
+            // Push an extra SYNC operation to flush previous writes
+            next_writes.push_back(op);
+            cluster_op_t *sync_op = new cluster_op_t;
+            sync_op->is_internal = true;
+            sync_op->opcode = OSD_OP_SYNC;
+            sync_op->callback = [](cluster_op_t* sync_op) {};
+            execute_sync(sync_op);
+            return;
+        }
+        queued_bytes += op->len;
+    }
+    cur_ops.insert(op);
+    continue_rw(op);
+}
+
+void cluster_client_t::continue_rw(cluster_op_t *op)
+{
+    pool_id_t pool_id = INODE_POOL(op->inode);
+    if (!pool_id)
+    {
+        op->retval = -EINVAL;
+        std::function<void(cluster_op_t*)>(op->callback)(op);
+        return;
+    }
+    if (st_cli.pool_config.find(pool_id) == st_cli.pool_config.end() ||
+        st_cli.pool_config[pool_id].real_pg_count == 0)
+    {
+        // Postpone operations to unknown pools
+        return;
+    }
+    if (op->opcode == OSD_OP_WRITE && !immediate_commit && !op->is_internal)
+    {
+        // Save operation for replay when PG goes out of sync
+        // (primary OSD drops our connection in this case)
+        cluster_op_t *op_copy = new cluster_op_t();
+        op_copy->is_internal = true;
+        op_copy->orig_op = op;
+        op_copy->opcode = op->opcode;
+        op_copy->inode = op->inode;
+        op_copy->offset = op->offset;
+        op_copy->len = op->len;
+        op_copy->buf = malloc_or_die(op->len);
+        op_copy->iov.push_back(op_copy->buf, op->len);
+        op_copy->callback = [](cluster_op_t* op_copy)
+        {
+            if (op_copy->orig_op)
+            {
+                // Acknowledge write and forget the original pointer
+                op_copy->orig_op->retval = op_copy->retval;
+                std::function<void(cluster_op_t*)>(op_copy->orig_op->callback)(op_copy->orig_op);
+                op_copy->orig_op = NULL;
+            }
+        };
+        void *cur_buf = op_copy->buf;
+        for (int i = 0; i < op->iov.count; i++)
+        {
+            memcpy(cur_buf, op->iov.buf[i].iov_base, op->iov.buf[i].iov_len);
+            cur_buf += op->iov.buf[i].iov_len;
+        }
+        unsynced_writes.push_back(op_copy);
+        cur_ops.erase(op);
+        cur_ops.insert(op_copy);
+        op = op_copy;
+    }
+    if (!op->parts.size())
+    {
+        // Slice the operation into parts
+        slice_rw(op);
+    }
+    if (!op->needs_reslice)
+    {
+        // Send unsent parts, if they're not subject to change
+        for (auto & op_part: op->parts)
+        {
+            if (!op_part.sent && !op_part.done)
+            {
+                try_send(op, &op_part);
+            }
+        }
+    }
+    if (!op->sent_count)
+    {
+        if (op->done_count >= op->parts.size())
+        {
+            // Finished successfully
+            // Even if the PG count has changed in meanwhile we treat it as success
+            // because if some operations were invalid for the new PG count we'd get errors
+            cur_ops.erase(op);
+            op->retval = op->len;
+            std::function<void(cluster_op_t*)>(op->callback)(op);
+            continue_sync();
+            return;
+        }
+        else if (op->retval != 0 && op->retval != -EPIPE)
+        {
+            // Fatal error (not -EPIPE)
+            cur_ops.erase(op);
+            if (!immediate_commit && op->opcode == OSD_OP_WRITE)
+            {
+                for (int i = 0; i < unsynced_writes.size(); i++)
+                {
+                    if (unsynced_writes[i] == op)
+                    {
+                        unsynced_writes.erase(unsynced_writes.begin()+i, unsynced_writes.begin()+i+1);
+                        break;
+                    }
+                }
+            }
+            bool del = op->is_internal;
+            std::function<void(cluster_op_t*)>(op->callback)(op);
+            if (del)
+            {
+                if (op->buf)
+                    free(op->buf);
+                delete op;
+            }
+            continue_sync();
+            return;
+        }
+        else
+        {
+            // -EPIPE or no error - clear the error
+            op->retval = 0;
+            if (op->needs_reslice)
+            {
+                op->parts.clear();
+                op->done_count = 0;
+                op->needs_reslice = false;
+                continue_rw(op);
+            }
+        }
+    }
+}
+
+void cluster_client_t::slice_rw(cluster_op_t *op)
+{
+    // Slice the request into individual object stripe requests
+    // Primary OSDs still operate individual stripes, but their size is multiplied by PG minsize in case of EC
+    auto & pool_cfg = st_cli.pool_config[INODE_POOL(op->inode)];
+    uint64_t pg_block_size = bs_block_size * (
+        pool_cfg.scheme == POOL_SCHEME_REPLICATED ? 1 : pool_cfg.pg_minsize
+    );
+    uint64_t first_stripe = (op->offset / pg_block_size) * pg_block_size;
+    uint64_t last_stripe = ((op->offset + op->len + pg_block_size - 1) / pg_block_size - 1) * pg_block_size;
+    op->retval = 0;
+    op->parts.resize((last_stripe - first_stripe) / pg_block_size + 1);
+    int iov_idx = 0;
+    size_t iov_pos = 0;
+    int i = 0;
+    for (uint64_t stripe = first_stripe; stripe <= last_stripe; stripe += pg_block_size)
+    {
+        pg_num_t pg_num = (op->inode + stripe/pool_cfg.pg_stripe_size) % pool_cfg.real_pg_count + 1;
+        uint64_t begin = (op->offset < stripe ? stripe : op->offset);
+        uint64_t end = (op->offset + op->len) > (stripe + pg_block_size)
+            ? (stripe + pg_block_size) : (op->offset + op->len);
+        op->parts[i] = {
+            .parent = op,
+            .offset = begin,
+            .len = (uint32_t)(end - begin),
+            .pg_num = pg_num,
+            .sent = false,
+            .done = false,
+        };
+        int left = end-begin;
+        while (left > 0 && iov_idx < op->iov.count)
+        {
+            if (op->iov.buf[iov_idx].iov_len - iov_pos < left)
+            {
+                op->parts[i].iov.push_back(op->iov.buf[iov_idx].iov_base + iov_pos, op->iov.buf[iov_idx].iov_len - iov_pos);
+                left -= (op->iov.buf[iov_idx].iov_len - iov_pos);
+                iov_pos = 0;
+                iov_idx++;
+            }
+            else
+            {
+                op->parts[i].iov.push_back(op->iov.buf[iov_idx].iov_base + iov_pos, left);
+                iov_pos += left;
+                left = 0;
+            }
+        }
+        assert(left == 0);
+        i++;
+    }
+}
+
+bool cluster_client_t::try_send(cluster_op_t *op, cluster_op_part_t *part)
+{
+    auto & pool_cfg = st_cli.pool_config[INODE_POOL(op->inode)];
+    auto pg_it = pool_cfg.pg_config.find(part->pg_num);
+    if (pg_it != pool_cfg.pg_config.end() &&
+        !pg_it->second.pause && pg_it->second.cur_primary)
+    {
+        osd_num_t primary_osd = pg_it->second.cur_primary;
+        auto peer_it = msgr.osd_peer_fds.find(primary_osd);
+        if (peer_it != msgr.osd_peer_fds.end())
+        {
+            int peer_fd = peer_it->second;
+            part->osd_num = primary_osd;
+            part->sent = true;
+            op->sent_count++;
+            part->op = {
+                .op_type = OSD_OP_OUT,
+                .peer_fd = peer_fd,
+                .req = { .rw = {
+                    .header = {
+                        .magic = SECONDARY_OSD_OP_MAGIC,
+                        .id = op_id++,
+                        .opcode = op->opcode,
+                    },
+                    .inode = op->inode,
+                    .offset = part->offset,
+                    .len = part->len,
+                } },
+                .callback = [this, part](osd_op_t *op_part)
+                {
+                    handle_op_part(part);
+                },
+            };
+            part->op.iov = part->iov;
+            msgr.outbox_push(&part->op);
+            return true;
+        }
+        else if (msgr.wanted_peers.find(primary_osd) == msgr.wanted_peers.end())
+        {
+            msgr.connect_peer(primary_osd, st_cli.peer_states[primary_osd]);
+        }
+    }
+    return false;
+}
+
+void cluster_client_t::execute_sync(cluster_op_t *op)
+{
+    if (immediate_commit)
+    {
+        // Syncs are not required in the immediate_commit mode
+        op->retval = 0;
+        std::function<void(cluster_op_t*)>(op->callback)(op);
+    }
+    else if (cur_sync != NULL)
+    {
+        next_writes.push_back(op);
+    }
+    else
+    {
+        cur_sync = op;
+        continue_sync();
+    }
+}
+
+void cluster_client_t::continue_sync()
+{
+    if (!cur_sync || cur_sync->parts.size() > 0)
+    {
+        // Already submitted
+        return;
+    }
+    cur_sync->retval = 0;
+    std::set<osd_num_t> sync_osds;
+    for (auto prev_op: unsynced_writes)
+    {
+        if (prev_op->done_count < prev_op->parts.size())
+        {
+            // Writes not finished yet
+            return;
+        }
+        for (auto & part: prev_op->parts)
+        {
+            if (part.osd_num)
+            {
+                sync_osds.insert(part.osd_num);
+            }
+        }
+    }
+    if (!sync_osds.size())
+    {
+        // No dirty writes
+        finish_sync();
+        return;
+    }
+    // Check that all OSD connections are still alive
+    for (auto sync_osd: sync_osds)
+    {
+        auto peer_it = msgr.osd_peer_fds.find(sync_osd);
+        if (peer_it == msgr.osd_peer_fds.end())
+        {
+            // SYNC is pointless to send to a non connected OSD
+            return;
+        }
+    }
+    syncing_writes.swap(unsynced_writes);
+    // Post sync to affected OSDs
+    cur_sync->parts.resize(sync_osds.size());
+    int i = 0;
+    for (auto sync_osd: sync_osds)
+    {
+        cur_sync->parts[i] = {
+            .parent = cur_sync,
+            .osd_num = sync_osd,
+            .sent = false,
+            .done = false,
+        };
+        send_sync(cur_sync, &cur_sync->parts[i]);
+        i++;
+    }
+}
+
+void cluster_client_t::finish_sync()
+{
+    int retval = cur_sync->retval;
+    if (retval != 0)
+    {
+        for (auto op: syncing_writes)
+        {
+            if (op->done_count < op->parts.size())
+            {
+                cur_ops.insert(op);
+            }
+        }
+        unsynced_writes.insert(unsynced_writes.begin(), syncing_writes.begin(), syncing_writes.end());
+        syncing_writes.clear();
+    }
+    if (retval == -EPIPE)
+    {
+        // Retry later
+        cur_sync->parts.clear();
+        cur_sync->retval = 0;
+        cur_sync->sent_count = 0;
+        cur_sync->done_count = 0;
+        return;
+    }
+    std::function<void(cluster_op_t*)>(cur_sync->callback)(cur_sync);
+    if (!retval)
+    {
+        for (auto op: syncing_writes)
+        {
+            assert(op->sent_count == 0);
+            if (op->is_internal)
+            {
+                if (op->buf)
+                    free(op->buf);
+                delete op;
+            }
+        }
+        syncing_writes.clear();
+    }
+    cur_sync = NULL;
+    queued_bytes = 0;
+    std::vector<cluster_op_t*> next_wr_copy;
+    next_wr_copy.swap(next_writes);
+    for (auto next_op: next_wr_copy)
+    {
+        execute(next_op);
+    }
+}
+
+void cluster_client_t::send_sync(cluster_op_t *op, cluster_op_part_t *part)
+{
+    auto peer_it = msgr.osd_peer_fds.find(part->osd_num);
+    assert(peer_it != msgr.osd_peer_fds.end());
+    part->sent = true;
+    op->sent_count++;
+    part->op = {
+        .op_type = OSD_OP_OUT,
+        .peer_fd = peer_it->second,
+        .req = {
+            .hdr = {
+                .magic = SECONDARY_OSD_OP_MAGIC,
+                .id = op_id++,
+                .opcode = OSD_OP_SYNC,
+            },
+        },
+        .callback = [this, part](osd_op_t *op_part)
+        {
+            handle_op_part(part);
+        },
+    };
+    msgr.outbox_push(&part->op);
+}
+
+void cluster_client_t::handle_op_part(cluster_op_part_t *part)
+{
+    cluster_op_t *op = part->parent;
+    part->sent = false;
+    op->sent_count--;
+    int expected = part->op.req.hdr.opcode == OSD_OP_SYNC ? 0 : part->op.req.rw.len;
+    if (part->op.reply.hdr.retval != expected)
+    {
+        // Operation failed, retry
+        printf(
+            "Operation failed on OSD %lu: retval=%ld (expected %d), dropping connection\n",
+            part->osd_num, part->op.reply.hdr.retval, expected
+        );
+        msgr.stop_client(part->op.peer_fd);
+        if (part->op.reply.hdr.retval == -EPIPE)
+        {
+            op->up_wait = true;
+            if (!retry_timeout_id)
+            {
+                retry_timeout_id = tfd->set_timer(up_wait_retry_interval, false, [this](int)
+                {
+                    retry_timeout_id = 0;
+                    continue_ops(true);
+                });
+            }
+        }
+        if (!op->retval || op->retval == -EPIPE)
+        {
+            // Don't overwrite other errors with -EPIPE
+            op->retval = part->op.reply.hdr.retval;
+        }
+    }
+    else
+    {
+        // OK
+        part->done = true;
+        op->done_count++;
+    }
+    if (op->sent_count == 0)
+    {
+        if (op->opcode == OSD_OP_SYNC)
+        {
+            assert(op == cur_sync);
+            finish_sync();
+        }
+        else
+        {
+            continue_rw(op);
+        }
+    }
+}

cluster_client.h

@@ -0,0 +1,102 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include "messenger.h"
+#include "etcd_state_client.h"
+
+#define MIN_BLOCK_SIZE 4*1024
+#define MAX_BLOCK_SIZE 128*1024*1024
+#define DEFAULT_BLOCK_SIZE 128*1024
+#define DEFAULT_DISK_ALIGNMENT 4096
+#define DEFAULT_BITMAP_GRANULARITY 4096
+#define DEFAULT_CLIENT_DIRTY_LIMIT 32*1024*1024
+
+struct cluster_op_t;
+
+struct cluster_op_part_t
+{
+    cluster_op_t *parent;
+    uint64_t offset;
+    uint32_t len;
+    pg_num_t pg_num;
+    osd_num_t osd_num;
+    osd_op_buf_list_t iov;
+    bool sent;
+    bool done;
+    osd_op_t op;
+};
+
+struct cluster_op_t
+{
+    uint64_t opcode; // OSD_OP_READ, OSD_OP_WRITE, OSD_OP_SYNC
+    uint64_t inode;
+    uint64_t offset;
+    uint64_t len;
+    int retval;
+    osd_op_buf_list_t iov;
+    std::function<void(cluster_op_t*)> callback;
+protected:
+    void *buf = NULL;
+    cluster_op_t *orig_op = NULL;
+    bool is_internal = false;
+    bool needs_reslice = false;
+    bool up_wait = false;
+    int sent_count = 0, done_count = 0;
+    std::vector<cluster_op_part_t> parts;
+    friend class cluster_client_t;
+};
+
+class cluster_client_t
+{
+    timerfd_manager_t *tfd;
+    ring_loop_t *ringloop;
+
+    uint64_t bs_block_size = 0;
+    uint64_t bs_disk_alignment = 0;
+    uint64_t bs_bitmap_granularity = 0;
+    std::map<pool_id_t, uint64_t> pg_counts;
+    bool immediate_commit = false;
+    // FIXME: Implement inmemory_commit mode. Note that it requires to return overlapping reads from memory.
+    uint64_t client_dirty_limit = 0;
+    int log_level;
+    int up_wait_retry_interval = 500; // ms
+
+    uint64_t op_id = 1;
+    etcd_state_client_t st_cli;
+    osd_messenger_t msgr;
+    ring_consumer_t consumer;
+    // operations currently in progress
+    std::set<cluster_op_t*> cur_ops;
+    int retry_timeout_id = 0;
+    // unsynced operations are copied in memory to allow replay when cluster isn't in the immediate_commit mode
+    // unsynced_writes are replayed in any order (because only the SYNC operation guarantees ordering)
+    std::vector<cluster_op_t*> unsynced_writes;
+    std::vector<cluster_op_t*> syncing_writes;
+    cluster_op_t* cur_sync = NULL;
+    std::vector<cluster_op_t*> next_writes;
+    std::vector<cluster_op_t*> offline_ops;
+    uint64_t queued_bytes = 0;
+
+public:
+    cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd, json11::Json & config);
+    ~cluster_client_t();
+    void execute(cluster_op_t *op);
+    void stop();
+
+protected:
+    void continue_ops(bool up_retry = false);
+    void on_load_config_hook(json11::Json::object & config);
+    void on_load_pgs_hook(bool success);
+    void on_change_hook(json11::Json::object & changes);
+    void on_change_osd_state_hook(uint64_t peer_osd);
+    void continue_rw(cluster_op_t *op);
+    void slice_rw(cluster_op_t *op);
+    bool try_send(cluster_op_t *op, cluster_op_part_t *part);
+    void execute_sync(cluster_op_t *op);
+    void continue_sync();
+    void finish_sync();
+    void send_sync(cluster_op_t *op, cluster_op_part_t *part);
+    void handle_op_part(cluster_op_part_t *part);
+};

cpp-btree

@@ -0,0 +1 @@
+Subproject commit 5dc108754ad40d3b1d024f9bd7cca0595ef1a1db

dump_journal.cpp

@@ -0,0 +1,173 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#define _LARGEFILE64_SOURCE
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <malloc.h>
+#include <linux/fs.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include "blockstore_impl.h"
+#include "crc32c.h"
+
+struct journal_dump_t
+{
+    char *journal_device;
+    uint32_t journal_block;
+    uint64_t journal_offset;
+    uint64_t journal_len;
+    uint64_t journal_pos;
+    int fd;
+
+    void dump_block(void *buf);
+};
+
+int main(int argc, char *argv[])
+{
+    if (argc < 5)
+    {
+        printf("USAGE: %s <journal_file> <journal_block_size> <offset> <size>\n", argv[0]);
+        return 1;
+    }
+    journal_dump_t self;
+    self.journal_device = argv[1];
+    self.journal_block = strtoul(argv[2], NULL, 10);
+    self.journal_offset = strtoull(argv[3], NULL, 10);
+    self.journal_len = strtoull(argv[4], NULL, 10);
+    if (self.journal_block < MEM_ALIGNMENT || (self.journal_block % MEM_ALIGNMENT) ||
+        self.journal_block > 128*1024)
+    {
+        printf("Invalid journal block size\n");
+        return 1;
+    }
+    self.fd = open(self.journal_device, O_DIRECT|O_RDONLY);
+    if (self.fd == -1)
+    {
+        printf("Failed to open journal\n");
+        return 1;
+    }
+    void *data = memalign(MEM_ALIGNMENT, self.journal_block);
+    self.journal_pos = 0;
+    while (self.journal_pos < self.journal_len)
+    {
+        int r = pread(self.fd, data, self.journal_block, self.journal_offset+self.journal_pos);
+        assert(r == self.journal_block);
+        uint64_t s;
+        for (s = 0; s < self.journal_block; s += 8)
+        {
+            if (*((uint64_t*)(data+s)) != 0)
+                break;
+        }
+        if (s == self.journal_block)
+        {
+            printf("offset %08lx: zeroes\n", self.journal_pos);
+            self.journal_pos += self.journal_block;
+        }
+        else if (((journal_entry*)data)->magic == JOURNAL_MAGIC)
+        {
+            printf("offset %08lx:\n", self.journal_pos);
+            self.dump_block(data);
+        }
+        else
+        {
+            printf("offset %08lx: no magic in the beginning, looks like random data (pattern=%lx)\n", self.journal_pos, *((uint64_t*)data));
+            self.journal_pos += self.journal_block;
+        }
+    }
+    free(data);
+    close(self.fd);
+    return 0;
+}
+
+void journal_dump_t::dump_block(void *buf)
+{
+    uint32_t pos = 0;
+    journal_pos += journal_block;
+    int entry = 0;
+    bool wrapped = false;
+    while (pos < journal_block)
+    {
+        journal_entry *je = (journal_entry*)(buf + pos);
+        if (je->magic != JOURNAL_MAGIC || je->type < JE_MIN || je->type > JE_MAX)
+        {
+            break;
+        }
+        const char *crc32_valid = je_crc32(je) == je->crc32 ? "(valid)" : "(invalid)";
+        printf("entry % 3d: crc32=%08x %s prev=%08x ", entry, je->crc32, crc32_valid, je->crc32_prev);
+        if (je->type == JE_START)
+        {
+            printf("je_start start=%08lx\n", je->start.journal_start);
+        }
+        else if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
+        {
+            printf(
+                "je_small_write%s oid=%lx:%lx ver=%lu offset=%u len=%u loc=%08lx",
+                je->type == JE_SMALL_WRITE_INSTANT ? "_instant" : "",
+                je->small_write.oid.inode, je->small_write.oid.stripe,
+                je->small_write.version, je->small_write.offset, je->small_write.len,
+                je->small_write.data_offset
+            );
+            if (journal_pos + je->small_write.len > journal_len)
+            {
+                // data continues from the beginning of the journal
+                journal_pos = journal_block;
+                wrapped = true;
+            }
+            if (journal_pos != je->small_write.data_offset)
+            {
+                printf(" (mismatched, calculated = %lu)", journal_pos);
+            }
+            journal_pos += je->small_write.len;
+            if (journal_pos >= journal_len)
+            {
+                journal_pos = journal_block;
+                wrapped = true;
+            }
+            uint32_t data_crc32 = 0;
+            void *data = memalign(MEM_ALIGNMENT, je->small_write.len);
+            assert(pread(fd, data, je->small_write.len, journal_offset+je->small_write.data_offset) == je->small_write.len);
+            data_crc32 = crc32c(0, data, je->small_write.len);
+            free(data);
+            printf(
+                " data_crc32=%08x%s", je->small_write.crc32_data,
+                (data_crc32 != je->small_write.crc32_data) ? " (invalid)" : " (valid)"
+            );
+            printf("\n");
+        }
+        else if (je->type == JE_BIG_WRITE || je->type == JE_BIG_WRITE_INSTANT)
+        {
+            printf(
+                "je_big_write%s oid=%lx:%lx ver=%lu loc=%08lx\n",
+                je->type == JE_BIG_WRITE_INSTANT ? "_instant" : "",
+                je->big_write.oid.inode, je->big_write.oid.stripe, je->big_write.version, je->big_write.location
+            );
+        }
+        else if (je->type == JE_STABLE)
+        {
+            printf("je_stable oid=%lx:%lx ver=%lu\n", je->stable.oid.inode, je->stable.oid.stripe, je->stable.version);
+        }
+        else if (je->type == JE_ROLLBACK)
+        {
+            printf("je_rollback oid=%lx:%lx ver=%lu\n", je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version);
+        }
+        else if (je->type == JE_DELETE)
+        {
+            printf("je_delete oid=%lx:%lx ver=%lu\n", je->del.oid.inode, je->del.oid.stripe, je->del.version);
+        }
+        pos += je->size;
+        entry++;
+    }
+    if (wrapped)
+    {
+        journal_pos = journal_len;
+    }
+}

epoll_manager.cpp

@@ -0,0 +1,90 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include <sys/epoll.h>
+#include <sys/poll.h>
+#include <unistd.h>
+
+#include "epoll_manager.h"
+
+#define MAX_EPOLL_EVENTS 64
+
+epoll_manager_t::epoll_manager_t(ring_loop_t *ringloop)
+{
+    this->ringloop = ringloop;
+
+    epoll_fd = epoll_create(1);
+    if (epoll_fd < 0)
+    {
+        throw std::runtime_error(std::string("epoll_create: ") + strerror(errno));
+    }
+
+    tfd = new timerfd_manager_t([this](int fd, bool wr, std::function<void(int, int)> handler) { set_fd_handler(fd, wr, handler); });
+
+    handle_epoll_events();
+}
+
+epoll_manager_t::~epoll_manager_t()
+{
+    if (tfd)
+    {
+        delete tfd;
+        tfd = NULL;
+    }
+    close(epoll_fd);
+}
+
+void epoll_manager_t::set_fd_handler(int fd, bool wr, std::function<void(int, int)> handler)
+{
+    if (handler != NULL)
+    {
+        bool exists = epoll_handlers.find(fd) != epoll_handlers.end();
+        epoll_event ev;
+        ev.data.fd = fd;
+        ev.events = (wr ? EPOLLOUT : 0) | EPOLLIN | EPOLLRDHUP | EPOLLET;
+        if (epoll_ctl(epoll_fd, exists ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev) < 0)
+        {
+            throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
+        }
+        epoll_handlers[fd] = handler;
+    }
+    else
+    {
+        if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, NULL) < 0 && errno != ENOENT)
+        {
+            throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
+        }
+        epoll_handlers.erase(fd);
+    }
+}
+
+void epoll_manager_t::handle_epoll_events()
+{
+    io_uring_sqe *sqe = ringloop->get_sqe();
+    if (!sqe)
+    {
+        throw std::runtime_error("can't get SQE, will fall out of sync with EPOLLET");
+    }
+    ring_data_t *data = ((ring_data_t*)sqe->user_data);
+    my_uring_prep_poll_add(sqe, epoll_fd, POLLIN);
+    data->callback = [this](ring_data_t *data)
+    {
+        if (data->res < 0)
+        {
+            throw std::runtime_error(std::string("epoll failed: ") + strerror(-data->res));
+        }
+        handle_epoll_events();
+    };
+    ringloop->submit();
+    int nfds;
+    epoll_event events[MAX_EPOLL_EVENTS];
+    do
+    {
+        nfds = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, 0);
+        for (int i = 0; i < nfds; i++)
+        {
+            auto & cb = epoll_handlers[events[i].data.fd];
+            cb(events[i].data.fd, events[i].events);
+        }
+    } while (nfds == MAX_EPOLL_EVENTS);
+}

epoll_manager.h

@@ -0,0 +1,23 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include <map>
+
+#include "ringloop.h"
+#include "timerfd_manager.h"
+
+class epoll_manager_t
+{
+    int epoll_fd;
+    ring_loop_t *ringloop;
+    std::map<int, std::function<void(int, int)>> epoll_handlers;
+public:
+    epoll_manager_t(ring_loop_t *ringloop);
+    ~epoll_manager_t();
+    void set_fd_handler(int fd, bool wr, std::function<void(int, int)> handler);
+    void handle_epoll_events();
+
+    timerfd_manager_t *tfd;
+};

etcd_state_client.cpp

@@ -0,0 +1,556 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "osd_ops.h"
+#include "pg_states.h"
+#include "etcd_state_client.h"
+#include "http_client.h"
+#include "base64.h"
+
+json_kv_t etcd_state_client_t::parse_etcd_kv(const json11::Json & kv_json)
+{
+    json_kv_t kv;
+    kv.key = base64_decode(kv_json["key"].string_value());
+    std::string json_err, json_text = base64_decode(kv_json["value"].string_value());
+    kv.value = json_text == "" ? json11::Json() : json11::Json::parse(json_text, json_err);
+    if (json_err != "")
+    {
+        printf("Bad JSON in etcd key %s: %s (value: %s)\n", kv.key.c_str(), json_err.c_str(), json_text.c_str());
+        kv.key = "";
+    }
+    return kv;
+}
+
+void etcd_state_client_t::etcd_txn(json11::Json txn, int timeout, std::function<void(std::string, json11::Json)> callback)
+{
+    etcd_call("/kv/txn", txn, timeout, callback);
+}
+
+void etcd_state_client_t::etcd_call(std::string api, json11::Json payload, int timeout, std::function<void(std::string, json11::Json)> callback)
+{
+    std::string etcd_address = etcd_addresses[rand() % etcd_addresses.size()];
+    std::string etcd_api_path;
+    int pos = etcd_address.find('/');
+    if (pos >= 0)
+    {
+        etcd_api_path = etcd_address.substr(pos);
+        etcd_address = etcd_address.substr(0, pos);
+    }
+    std::string req = payload.dump();
+    req = "POST "+etcd_api_path+api+" HTTP/1.1\r\n"
+        "Host: "+etcd_address+"\r\n"
+        "Content-Type: application/json\r\n"
+        "Content-Length: "+std::to_string(req.size())+"\r\n"
+        "Connection: close\r\n"
+        "\r\n"+req;
+    http_request_json(tfd, etcd_address, req, timeout, callback);
+}
+
+void etcd_state_client_t::parse_config(json11::Json & config)
+{
+    this->etcd_addresses.clear();
+    if (config["etcd_address"].is_string())
+    {
+        std::string ea = config["etcd_address"].string_value();
+        while (1)
+        {
+            int pos = ea.find(',');
+            std::string addr = pos >= 0 ? ea.substr(0, pos) : ea;
+            if (addr.length() > 0)
+            {
+                if (addr.find('/') < 0)
+                    addr += "/v3";
+                this->etcd_addresses.push_back(addr);
+            }
+            if (pos >= 0)
+                ea = ea.substr(pos+1);
+            else
+                break;
+        }
+    }
+    else if (config["etcd_address"].array_items().size())
+    {
+        for (auto & ea: config["etcd_address"].array_items())
+        {
+            std::string addr = ea.string_value();
+            if (addr != "")
+            {
+                if (addr.find('/') < 0)
+                    addr += "/v3";
+                this->etcd_addresses.push_back(addr);
+            }
+        }
+    }
+    this->etcd_prefix = config["etcd_prefix"].string_value();
+    if (this->etcd_prefix == "")
+    {
+        this->etcd_prefix = "/vitastor";
+    }
+    else if (this->etcd_prefix[0] != '/')
+    {
+        this->etcd_prefix = "/"+this->etcd_prefix;
+    }
+    this->log_level = config["log_level"].int64_value();
+}
+
+void etcd_state_client_t::start_etcd_watcher()
+{
+    std::string etcd_address = etcd_addresses[rand() % etcd_addresses.size()];
+    std::string etcd_api_path;
+    int pos = etcd_address.find('/');
+    if (pos >= 0)
+    {
+        etcd_api_path = etcd_address.substr(pos);
+        etcd_address = etcd_address.substr(0, pos);
+    }
+    etcd_watches_initialised = 0;
+    etcd_watch_ws = open_websocket(tfd, etcd_address, etcd_api_path+"/watch", ETCD_SLOW_TIMEOUT, [this](const http_response_t *msg)
+    {
+        if (msg->body.length())
+        {
+            std::string json_err;
+            json11::Json data = json11::Json::parse(msg->body, json_err);
+            if (json_err != "")
+            {
+                printf("Bad JSON in etcd event: %s, ignoring event\n", json_err.c_str());
+            }
+            else
+            {
+                if (data["result"]["created"].bool_value())
+                {
+                    etcd_watches_initialised++;
+                }
+                if (etcd_watches_initialised == 4)
+                {
+                    etcd_watch_revision = data["result"]["header"]["revision"].uint64_value();
+                }
+                // First gather all changes into a hash to remove multiple overwrites
+                json11::Json::object changes;
+                for (auto & ev: data["result"]["events"].array_items())
+                {
+                    auto kv = parse_etcd_kv(ev["kv"]);
+                    if (kv.key != "")
+                    {
+                        changes[kv.key] = kv.value;
+                    }
+                }
+                for (auto & kv: changes)
+                {
+                    if (this->log_level > 0)
+                    {
+                        printf("Incoming event: %s -> %s\n", kv.first.c_str(), kv.second.dump().c_str());
+                    }
+                    parse_state(kv.first, kv.second);
+                }
+                // React to changes
+                if (on_change_hook != NULL)
+                {
+                    on_change_hook(changes);
+                }
+            }
+        }
+        if (msg->eof)
+        {
+            etcd_watch_ws = NULL;
+            if (etcd_watches_initialised == 0)
+            {
+                // Connection not established, retry in <ETCD_SLOW_TIMEOUT>
+                tfd->set_timer(ETCD_SLOW_TIMEOUT, false, [this](int)
+                {
+                    start_etcd_watcher();
+                });
+            }
+            else
+            {
+                // Connection was live, retry immediately
+                start_etcd_watcher();
+            }
+        }
+    });
+    etcd_watch_ws->post_message(WS_TEXT, json11::Json(json11::Json::object {
+        { "create_request", json11::Json::object {
+            { "key", base64_encode(etcd_prefix+"/config/") },
+            { "range_end", base64_encode(etcd_prefix+"/config0") },
+            { "start_revision", etcd_watch_revision+1 },
+            { "watch_id", ETCD_CONFIG_WATCH_ID },
+        } }
+    }).dump());
+    etcd_watch_ws->post_message(WS_TEXT, json11::Json(json11::Json::object {
+        { "create_request", json11::Json::object {
+            { "key", base64_encode(etcd_prefix+"/osd/state/") },
+            { "range_end", base64_encode(etcd_prefix+"/osd/state0") },
+            { "start_revision", etcd_watch_revision+1 },
+            { "watch_id", ETCD_OSD_STATE_WATCH_ID },
+        } }
+    }).dump());
+    etcd_watch_ws->post_message(WS_TEXT, json11::Json(json11::Json::object {
+        { "create_request", json11::Json::object {
+            { "key", base64_encode(etcd_prefix+"/pg/state/") },
+            { "range_end", base64_encode(etcd_prefix+"/pg/state0") },
+            { "start_revision", etcd_watch_revision+1 },
+            { "watch_id", ETCD_PG_STATE_WATCH_ID },
+        } }
+    }).dump());
+    etcd_watch_ws->post_message(WS_TEXT, json11::Json(json11::Json::object {
+        { "create_request", json11::Json::object {
+            { "key", base64_encode(etcd_prefix+"/pg/history/") },
+            { "range_end", base64_encode(etcd_prefix+"/pg/history0") },
+            { "start_revision", etcd_watch_revision+1 },
+            { "watch_id", ETCD_PG_HISTORY_WATCH_ID },
+        } }
+    }).dump());
+}
+
+void etcd_state_client_t::load_global_config()
+{
+    etcd_call("/kv/range", json11::Json::object {
+        { "key", base64_encode(etcd_prefix+"/config/global") }
+    }, ETCD_SLOW_TIMEOUT, [this](std::string err, json11::Json data)
+    {
+        if (err != "")
+        {
+            printf("Error reading OSD configuration from etcd: %s\n", err.c_str());
+            tfd->set_timer(ETCD_SLOW_TIMEOUT, false, [this](int timer_id)
+            {
+                load_global_config();
+            });
+            return;
+        }
+        if (!etcd_watch_revision)
+        {
+            etcd_watch_revision = data["header"]["revision"].uint64_value();
+        }
+        json11::Json::object global_config;
+        if (data["kvs"].array_items().size() > 0)
+        {
+            auto kv = parse_etcd_kv(data["kvs"][0]);
+            if (kv.value.is_object())
+            {
+                global_config = kv.value.object_items();
+            }
+        }
+        on_load_config_hook(global_config);
+    });
+}
+
+void etcd_state_client_t::load_pgs()
+{
+    json11::Json::array txn = {
+        json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", base64_encode(etcd_prefix+"/config/pools") },
+            } }
+        },
+        json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", base64_encode(etcd_prefix+"/config/pgs") },
+            } }
+        },
+        json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", base64_encode(etcd_prefix+"/pg/history/") },
+                { "range_end", base64_encode(etcd_prefix+"/pg/history0") },
+            } }
+        },
+        json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", base64_encode(etcd_prefix+"/pg/state/") },
+                { "range_end", base64_encode(etcd_prefix+"/pg/state0") },
+            } }
+        },
+        json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", base64_encode(etcd_prefix+"/osd/state/") },
+                { "range_end", base64_encode(etcd_prefix+"/osd/state0") },
+            } }
+        },
+    };
+    json11::Json::object req = { { "success", txn } };
+    json11::Json checks = load_pgs_checks_hook != NULL ? load_pgs_checks_hook() : json11::Json();
+    if (checks.array_items().size() > 0)
+    {
+        req["compare"] = checks;
+    }
+    etcd_txn(req, ETCD_SLOW_TIMEOUT, [this](std::string err, json11::Json data)
+    {
+        if (err != "")
+        {
+            printf("Error loading PGs from etcd: %s\n", err.c_str());
+            tfd->set_timer(ETCD_SLOW_TIMEOUT, false, [this](int timer_id)
+            {
+                load_pgs();
+            });
+            return;
+        }
+        if (!data["succeeded"].bool_value())
+        {
+            on_load_pgs_hook(false);
+            return;
+        }
+        for (auto & res: data["responses"].array_items())
+        {
+            for (auto & kv_json: res["response_range"]["kvs"].array_items())
+            {
+                auto kv = parse_etcd_kv(kv_json);
+                parse_state(kv.key, kv.value);
+            }
+        }
+        on_load_pgs_hook(true);
+    });
+}
+
+void etcd_state_client_t::parse_state(const std::string & key, const json11::Json & value)
+{
+    if (key == etcd_prefix+"/config/pools")
+    {
+        for (auto & pool_item: this->pool_config)
+        {
+            pool_item.second.exists = false;
+        }
+        for (auto & pool_item: value.object_items())
+        {
+            pool_id_t pool_id = stoull_full(pool_item.first);
+            if (!pool_id || pool_id >= POOL_ID_MAX)
+            {
+                printf("Pool ID %s is invalid (must be a number less than 0x%x), skipping pool\n", pool_item.first.c_str(), POOL_ID_MAX);
+                continue;
+            }
+            if (pool_item.second["pg_size"].uint64_value() < 1 ||
+                pool_item.second["scheme"] == "xor" && pool_item.second["pg_size"].uint64_value() < 3)
+            {
+                printf("Pool %u has invalid pg_size, skipping pool\n", pool_id);
+                continue;
+            }
+            if (pool_item.second["pg_minsize"].uint64_value() < 1 ||
+                pool_item.second["pg_minsize"].uint64_value() > pool_item.second["pg_size"].uint64_value() ||
+                pool_item.second["pg_minsize"].uint64_value() < (pool_item.second["pg_size"].uint64_value() - 1))
+            {
+                printf("Pool %u has invalid pg_minsize, skipping pool\n", pool_id);
+                continue;
+            }
+            if (pool_item.second["pg_count"].uint64_value() < 1)
+            {
+                printf("Pool %u has invalid pg_count, skipping pool\n", pool_id);
+                continue;
+            }
+            if (pool_item.second["name"].string_value() == "")
+            {
+                printf("Pool %u has empty name, skipping pool\n", pool_id);
+                continue;
+            }
+            if (pool_item.second["scheme"] != "replicated" && pool_item.second["scheme"] != "xor")
+            {
+                printf("Pool %u has invalid coding scheme (only \"xor\" and \"replicated\" are allowed), skipping pool\n", pool_id);
+                continue;
+            }
+            if (pool_item.second["max_osd_combinations"].uint64_value() > 0 &&
+                pool_item.second["max_osd_combinations"].uint64_value() < 100)
+            {
+                printf("Pool %u has invalid max_osd_combinations (must be at least 100), skipping pool\n", pool_id);
+                continue;
+            }
+            auto & parsed_cfg = this->pool_config[pool_id];
+            parsed_cfg.exists = true;
+            parsed_cfg.id = pool_id;
+            parsed_cfg.name = pool_item.second["name"].string_value();
+            parsed_cfg.scheme = pool_item.second["scheme"] == "replicated" ? POOL_SCHEME_REPLICATED : POOL_SCHEME_XOR;
+            parsed_cfg.pg_size = pool_item.second["pg_size"].uint64_value();
+            parsed_cfg.pg_minsize = pool_item.second["pg_minsize"].uint64_value();
+            parsed_cfg.pg_count = pool_item.second["pg_count"].uint64_value();
+            parsed_cfg.failure_domain = pool_item.second["failure_domain"].string_value();
+            parsed_cfg.pg_stripe_size = pool_item.second["pg_stripe_size"].uint64_value();
+            if (!parsed_cfg.pg_stripe_size)
+            {
+                parsed_cfg.pg_stripe_size = DEFAULT_PG_STRIPE_SIZE;
+            }
+            parsed_cfg.max_osd_combinations = pool_item.second["max_osd_combinations"].uint64_value();
+            if (!parsed_cfg.max_osd_combinations)
+            {
+                parsed_cfg.max_osd_combinations = 10000;
+            }
+            for (auto & pg_item: parsed_cfg.pg_config)
+            {
+                if (pg_item.second.target_set.size() != parsed_cfg.pg_size)
+                {
+                    printf("Pool %u PG %u configuration is invalid: osd_set size %lu != pool pg_size %lu\n",
+                        pool_id, pg_item.first, pg_item.second.target_set.size(), parsed_cfg.pg_size);
+                    pg_item.second.pause = true;
+                }
+            }
+        }
+    }
+    else if (key == etcd_prefix+"/config/pgs")
+    {
+        for (auto & pool_item: this->pool_config)
+        {
+            for (auto & pg_item: pool_item.second.pg_config)
+            {
+                pg_item.second.exists = false;
+            }
+        }
+        for (auto & pool_item: value["items"].object_items())
+        {
+            pool_id_t pool_id = stoull_full(pool_item.first);
+            if (!pool_id || pool_id >= POOL_ID_MAX)
+            {
+                printf("Pool ID %s is invalid in PG configuration (must be a number less than 0x%x), skipping pool\n", pool_item.first.c_str(), POOL_ID_MAX);
+                continue;
+            }
+            for (auto & pg_item: pool_item.second.object_items())
+            {
+                pg_num_t pg_num = stoull_full(pg_item.first);
+                if (!pg_num)
+                {
+                    printf("Bad key in pool %u PG configuration: %s (must be a number), skipped\n", pool_id, pg_item.first.c_str());
+                    continue;
+                }
+                auto & parsed_cfg = this->pool_config[pool_id].pg_config[pg_num];
+                parsed_cfg.exists = true;
+                parsed_cfg.pause = pg_item.second["pause"].bool_value();
+                parsed_cfg.primary = pg_item.second["primary"].uint64_value();
+                parsed_cfg.target_set.clear();
+                for (auto & pg_osd: pg_item.second["osd_set"].array_items())
+                {
+                    parsed_cfg.target_set.push_back(pg_osd.uint64_value());
+                }
+                if (parsed_cfg.target_set.size() != pool_config[pool_id].pg_size)
+                {
+                    printf("Pool %u PG %u configuration is invalid: osd_set size %lu != pool pg_size %lu\n",
+                        pool_id, pg_num, parsed_cfg.target_set.size(), pool_config[pool_id].pg_size);
+                    parsed_cfg.pause = true;
+                }
+            }
+        }
+        for (auto & pool_item: this->pool_config)
+        {
+            int n = 0;
+            for (auto pg_it = pool_item.second.pg_config.begin(); pg_it != pool_item.second.pg_config.end(); pg_it++)
+            {
+                if (pg_it->second.exists && pg_it->first != ++n)
+                {
+                    printf(
+                        "Invalid pool %u PG configuration: PG numbers don't cover whole 1..%lu range\n",
+                        pool_item.second.id, pool_item.second.pg_config.size()
+                    );
+                    for (pg_it = pool_item.second.pg_config.begin(); pg_it != pool_item.second.pg_config.end(); pg_it++)
+                    {
+                        pg_it->second.exists = false;
+                    }
+                    n = 0;
+                    break;
+                }
+            }
+            pool_item.second.real_pg_count = n;
+        }
+    }
+    else if (key.substr(0, etcd_prefix.length()+12) == etcd_prefix+"/pg/history/")
+    {
+        // <etcd_prefix>/pg/history/%d/%d
+        pool_id_t pool_id = 0;
+        pg_num_t pg_num = 0;
+        char null_byte = 0;
+        sscanf(key.c_str() + etcd_prefix.length()+12, "%u/%u%c", &pool_id, &pg_num, &null_byte);
+        if (!pool_id || pool_id >= POOL_ID_MAX || !pg_num || null_byte != 0)
+        {
+            printf("Bad etcd key %s, ignoring\n", key.c_str());
+        }
+        else
+        {
+            auto & pg_cfg = this->pool_config[pool_id].pg_config[pg_num];
+            pg_cfg.target_history.clear();
+            pg_cfg.all_peers.clear();
+            // Refuse to start PG if any set of the <osd_sets> has no live OSDs
+            for (auto hist_item: value["osd_sets"].array_items())
+            {
+                std::vector<osd_num_t> history_set;
+                for (auto pg_osd: hist_item.array_items())
+                {
+                    history_set.push_back(pg_osd.uint64_value());
+                }
+                pg_cfg.target_history.push_back(history_set);
+            }
+            // Include these additional OSDs when peering the PG
+            for (auto pg_osd: value["all_peers"].array_items())
+            {
+                pg_cfg.all_peers.push_back(pg_osd.uint64_value());
+            }
+            // Read epoch
+            pg_cfg.epoch = value["epoch"].uint64_value();
+            if (on_change_pg_history_hook != NULL)
+            {
+                on_change_pg_history_hook(pool_id, pg_num);
+            }
+        }
+    }
+    else if (key.substr(0, etcd_prefix.length()+10) == etcd_prefix+"/pg/state/")
+    {
+        // <etcd_prefix>/pg/state/%d/%d
+        pool_id_t pool_id = 0;
+        pg_num_t pg_num = 0;
+        char null_byte = 0;
+        sscanf(key.c_str() + etcd_prefix.length()+10, "%u/%u%c", &pool_id, &pg_num, &null_byte);
+        if (!pool_id || pool_id >= POOL_ID_MAX || !pg_num || null_byte != 0)
+        {
+            printf("Bad etcd key %s, ignoring\n", key.c_str());
+        }
+        else if (value.is_null())
+        {
+            this->pool_config[pool_id].pg_config[pg_num].cur_primary = 0;
+            this->pool_config[pool_id].pg_config[pg_num].cur_state = 0;
+        }
+        else
+        {
+            osd_num_t cur_primary = value["primary"].uint64_value();
+            int state = 0;
+            for (auto & e: value["state"].array_items())
+            {
+                int i;
+                for (i = 0; i < pg_state_bit_count; i++)
+                {
+                    if (e.string_value() == pg_state_names[i])
+                    {
+                        state = state | pg_state_bits[i];
+                        break;
+                    }
+                }
+                if (i >= pg_state_bit_count)
+                {
+                    printf("Unexpected pool %u PG %u state keyword in etcd: %s\n", pool_id, pg_num, e.dump().c_str());
+                    return;
+                }
+            }
+            if (!cur_primary || !value["state"].is_array() || !state ||
+                (state & PG_OFFLINE) && state != PG_OFFLINE ||
+                (state & PG_PEERING) && state != PG_PEERING ||
+                (state & PG_INCOMPLETE) && state != PG_INCOMPLETE)
+            {
+                printf("Unexpected pool %u PG %u state in etcd: primary=%lu, state=%s\n", pool_id, pg_num, cur_primary, value["state"].dump().c_str());
+                return;
+            }
+            this->pool_config[pool_id].pg_config[pg_num].cur_primary = cur_primary;
+            this->pool_config[pool_id].pg_config[pg_num].cur_state = state;
+        }
+    }
+    else if (key.substr(0, etcd_prefix.length()+11) == etcd_prefix+"/osd/state/")
+    {
+        // <etcd_prefix>/osd/state/%d
+        osd_num_t peer_osd = std::stoull(key.substr(etcd_prefix.length()+11));
+        if (peer_osd > 0)
+        {
+            if (value.is_object() && value["state"] == "up" &&
+                value["addresses"].is_array() &&
+                value["port"].int64_value() > 0 && value["port"].int64_value() < 65536)
+            {
+                this->peer_states[peer_osd] = value;
+            }
+            else
+            {
+                this->peer_states.erase(peer_osd);
+            }
+            if (on_change_osd_state_hook != NULL)
+            {
+                on_change_osd_state_hook(peer_osd);
+            }
+        }
+    }
+}

etcd_state_client.h

@@ -0,0 +1,83 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include "osd_id.h"
+#include "http_client.h"
+#include "timerfd_manager.h"
+
+#define ETCD_CONFIG_WATCH_ID 1
+#define ETCD_PG_STATE_WATCH_ID 2
+#define ETCD_PG_HISTORY_WATCH_ID 3
+#define ETCD_OSD_STATE_WATCH_ID 4
+
+#define MAX_ETCD_ATTEMPTS 5
+#define ETCD_SLOW_TIMEOUT 5000
+#define ETCD_QUICK_TIMEOUT 1000
+
+#define DEFAULT_PG_STRIPE_SIZE 4*1024*1024
+
+struct json_kv_t
+{
+    std::string key;
+    json11::Json value;
+};
+
+struct pg_config_t
+{
+    bool exists;
+    osd_num_t primary;
+    std::vector<osd_num_t> target_set;
+    std::vector<std::vector<osd_num_t>> target_history;
+    std::vector<osd_num_t> all_peers;
+    bool pause;
+    osd_num_t cur_primary;
+    int cur_state;
+    uint64_t epoch;
+};
+
+struct pool_config_t
+{
+    bool exists;
+    pool_id_t id;
+    std::string name;
+    uint64_t scheme;
+    uint64_t pg_size, pg_minsize;
+    uint64_t pg_count;
+    uint64_t real_pg_count;
+    std::string failure_domain;
+    uint64_t max_osd_combinations;
+    uint64_t pg_stripe_size;
+    std::map<pg_num_t, pg_config_t> pg_config;
+};
+
+struct etcd_state_client_t
+{
+    std::vector<std::string> etcd_addresses;
+    std::string etcd_prefix;
+    int log_level = 0;
+    timerfd_manager_t *tfd = NULL;
+
+    int etcd_watches_initialised = 0;
+    uint64_t etcd_watch_revision = 0;
+    websocket_t *etcd_watch_ws = NULL;
+    std::map<pool_id_t, pool_config_t> pool_config;
+    std::map<osd_num_t, json11::Json> peer_states;
+
+    std::function<void(json11::Json::object &)> on_change_hook;
+    std::function<void(json11::Json::object &)> on_load_config_hook;
+    std::function<json11::Json()> load_pgs_checks_hook;
+    std::function<void(bool)> on_load_pgs_hook;
+    std::function<void(pool_id_t, pg_num_t)> on_change_pg_history_hook;
+    std::function<void(osd_num_t)> on_change_osd_state_hook;
+
+    json_kv_t parse_etcd_kv(const json11::Json & kv_json);
+    void etcd_call(std::string api, json11::Json payload, int timeout, std::function<void(std::string, json11::Json)> callback);
+    void etcd_txn(json11::Json txn, int timeout, std::function<void(std::string, json11::Json)> callback);
+    void start_etcd_watcher();
+    void load_global_config();
+    void load_pgs();
+    void parse_state(const std::string & key, const json11::Json & value);
+    void parse_config(json11::Json & config);
+};

fio_cluster.cpp

@@ -0,0 +1,338 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+// FIO engine to test cluster I/O
+//
+// Random write:
+//
+// fio -thread -ioengine=./libfio_cluster.so -name=test -bs=4k -direct=1 -fsync=16 -iodepth=16 -rw=randwrite \
+//     -etcd=127.0.0.1:2379 [-etcd_prefix=/vitastor] -pool=1 -inode=1 -size=1000M
+//
+// Linear write:
+//
+// fio -thread -ioengine=./libfio_cluster.so -name=test -bs=128k -direct=1 -fsync=32 -iodepth=32 -rw=write \
+//     -etcd=127.0.0.1:2379 [-etcd_prefix=/vitastor] -pool=1 -inode=1 -size=1000M
+//
+// Random read (run with -iodepth=32 or -iodepth=1):
+//
+// fio -thread -ioengine=./libfio_cluster.so -name=test -bs=4k -direct=1 -iodepth=32 -rw=randread \
+//     -etcd=127.0.0.1:2379 [-etcd_prefix=/vitastor] -pool=1 -inode=1 -size=1000M
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+
+#include <vector>
+#include <unordered_map>
+
+#include "epoll_manager.h"
+#include "cluster_client.h"
+extern "C" {
+#define CONFIG_HAVE_GETTID
+#define CONFIG_PWRITEV2
+#include "fio/fio.h"
+#include "fio/optgroup.h"
+}
+
+struct sec_data
+{
+    ring_loop_t *ringloop = NULL;
+    epoll_manager_t *epmgr = NULL;
+    cluster_client_t *cli = NULL;
+    bool last_sync = false;
+    /* The list of completed io_u structs. */
+    std::vector<io_u*> completed;
+    uint64_t op_n = 0, inflight = 0;
+    bool trace = false;
+};
+
+struct sec_options
+{
+    int __pad;
+    char *etcd_host = NULL;
+    char *etcd_prefix = NULL;
+    uint64_t pool = 0;
+    uint64_t inode = 0;
+    int cluster_log = 0;
+    int trace = 0;
+};
+
+static struct fio_option options[] = {
+    {
+        .name   = "etcd",
+        .lname  = "etcd address",
+        .type   = FIO_OPT_STR_STORE,
+        .off1   = offsetof(struct sec_options, etcd_host),
+        .help   = "etcd address in the form HOST:PORT[/PATH]",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name   = "etcd",
+        .lname  = "etcd key prefix",
+        .type   = FIO_OPT_STR_STORE,
+        .off1   = offsetof(struct sec_options, etcd_prefix),
+        .help   = "etcd key prefix, by default /vitastor",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name   = "pool",
+        .lname  = "pool number for the inode",
+        .type   = FIO_OPT_INT,
+        .off1   = offsetof(struct sec_options, pool),
+        .help   = "pool number for the inode to run tests on",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name   = "inode",
+        .lname  = "inode to run tests on",
+        .type   = FIO_OPT_INT,
+        .off1   = offsetof(struct sec_options, inode),
+        .help   = "inode to run tests on (1 by default)",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name   = "cluster_log_level",
+        .lname  = "cluster log level",
+        .type   = FIO_OPT_BOOL,
+        .off1   = offsetof(struct sec_options, cluster_log),
+        .help   = "Set log level for the Vitastor client",
+        .def    = "0",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name   = "osd_trace",
+        .lname  = "OSD trace",
+        .type   = FIO_OPT_BOOL,
+        .off1   = offsetof(struct sec_options, trace),
+        .help   = "Trace OSD operations",
+        .def    = "0",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
+    {
+        .name = NULL,
+    },
+};
+
+static int sec_setup(struct thread_data *td)
+{
+    sec_data *bsd;
+
+    bsd = new sec_data;
+    if (!bsd)
+    {
+        td_verror(td, errno, "calloc");
+        return 1;
+    }
+    td->io_ops_data = bsd;
+
+    if (!td->files_index)
+    {
+        add_file(td, "osd_cluster", 0, 0);
+        td->o.nr_files = td->o.nr_files ? : 1;
+        td->o.open_files++;
+    }
+
+    return 0;
+}
+
+static void sec_cleanup(struct thread_data *td)
+{
+    sec_data *bsd = (sec_data*)td->io_ops_data;
+    if (bsd)
+    {
+        delete bsd->cli;
+        delete bsd->epmgr;
+        delete bsd->ringloop;
+        bsd->cli = NULL;
+        bsd->epmgr = NULL;
+        bsd->ringloop = NULL;
+    }
+}
+
+/* Connect to the server from each thread. */
+static int sec_init(struct thread_data *td)
+{
+    sec_options *o = (sec_options*)td->eo;
+    sec_data *bsd = (sec_data*)td->io_ops_data;
+
+    json11::Json cfg = json11::Json::object {
+        { "etcd_address", std::string(o->etcd_host) },
+        { "etcd_prefix", std::string(o->etcd_prefix ? o->etcd_prefix : "/vitastor") },
+        { "log_level", o->cluster_log },
+    };
+
+    if (o->pool)
+        o->inode = (o->inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (o->pool << (64-POOL_ID_BITS));
+    if (!(o->inode >> (64-POOL_ID_BITS)))
+    {
+        td_verror(td, EINVAL, "pool is missing");
+        return 1;
+    }
+    bsd->ringloop = new ring_loop_t(512);
+    bsd->epmgr = new epoll_manager_t(bsd->ringloop);
+    bsd->cli = new cluster_client_t(bsd->ringloop, bsd->epmgr->tfd, cfg);
+
+    bsd->trace = o->trace ? true : false;
+
+    return 0;
+}
+
+/* Begin read or write request. */
+static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
+{
+    sec_options *opt = (sec_options*)td->eo;
+    sec_data *bsd = (sec_data*)td->io_ops_data;
+    int n = bsd->op_n;
+
+    fio_ro_check(td, io);
+    if (io->ddir == DDIR_SYNC && bsd->last_sync)
+    {
+        return FIO_Q_COMPLETED;
+    }
+
+    io->engine_data = bsd;
+    cluster_op_t *op = new cluster_op_t;
+
+    switch (io->ddir)
+    {
+    case DDIR_READ:
+        op->opcode = OSD_OP_READ;
+        op->inode = opt->inode;
+        op->offset = io->offset;
+        op->len = io->xfer_buflen;
+        op->iov.push_back(io->xfer_buf, io->xfer_buflen);
+        bsd->last_sync = false;
+        break;
+    case DDIR_WRITE:
+        op->opcode = OSD_OP_WRITE;
+        op->inode = opt->inode;
+        op->offset = io->offset;
+        op->len = io->xfer_buflen;
+        op->iov.push_back(io->xfer_buf, io->xfer_buflen);
+        bsd->last_sync = false;
+        break;
+    case DDIR_SYNC:
+        op->opcode = OSD_OP_SYNC;
+        bsd->last_sync = true;
+        break;
+    default:
+        io->error = EINVAL;
+        return FIO_Q_COMPLETED;
+    }
+
+    op->callback = [io, n](cluster_op_t *op)
+    {
+        io->error = op->retval < 0 ? -op->retval : 0;
+        sec_data *bsd = (sec_data*)io->engine_data;
+        bsd->inflight--;
+        bsd->completed.push_back(io);
+        if (bsd->trace)
+        {
+            printf("--- %s n=%d retval=%d\n", io->ddir == DDIR_READ ? "READ" :
+                (io->ddir == DDIR_WRITE ? "WRITE" : "SYNC"), n, op->retval);
+        }
+        delete op;
+    };
+
+    if (opt->trace)
+    {
+        if (io->ddir == DDIR_SYNC)
+        {
+            printf("+++ SYNC # %d\n", n);
+        }
+        else
+        {
+            printf("+++ %s # %d 0x%llx+%llx\n",
+                io->ddir == DDIR_READ ? "READ" : "WRITE",
+                n, io->offset, io->xfer_buflen);
+        }
+    }
+
+    io->error = 0;
+    bsd->inflight++;
+    bsd->op_n++;
+    bsd->cli->execute(op);
+
+    if (io->error != 0)
+        return FIO_Q_COMPLETED;
+    return FIO_Q_QUEUED;
+}
+
+static int sec_getevents(struct thread_data *td, unsigned int min, unsigned int max, const struct timespec *t)
+{
+    sec_data *bsd = (sec_data*)td->io_ops_data;
+    while (true)
+    {
+        bsd->ringloop->loop();
+        if (bsd->completed.size() >= min)
+            break;
+        bsd->ringloop->wait();
+    }
+    return bsd->completed.size();
+}
+
+static struct io_u *sec_event(struct thread_data *td, int event)
+{
+    sec_data *bsd = (sec_data*)td->io_ops_data;
+    if (bsd->completed.size() == 0)
+        return NULL;
+    /* FIXME We ignore the event number and assume fio calls us exactly once for [0..nr_events-1] */
+    struct io_u *ev = bsd->completed.back();
+    bsd->completed.pop_back();
+    return ev;
+}
+
+static int sec_io_u_init(struct thread_data *td, struct io_u *io)
+{
+    io->engine_data = NULL;
+    return 0;
+}
+
+static void sec_io_u_free(struct thread_data *td, struct io_u *io)
+{
+}
+
+static int sec_open_file(struct thread_data *td, struct fio_file *f)
+{
+    return 0;
+}
+
+static int sec_invalidate(struct thread_data *td, struct fio_file *f)
+{
+    return 0;
+}
+
+struct ioengine_ops ioengine = {
+    .name               = "vitastor_cluster",
+    .version            = FIO_IOOPS_VERSION,
+    .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
+    .setup              = sec_setup,
+    .init               = sec_init,
+    .queue              = sec_queue,
+    .getevents          = sec_getevents,
+    .event              = sec_event,
+    .cleanup            = sec_cleanup,
+    .open_file          = sec_open_file,
+    .invalidate         = sec_invalidate,
+    .io_u_init          = sec_io_u_init,
+    .io_u_free          = sec_io_u_free,
+    .option_struct_size = sizeof(struct sec_options),
+    .options            = options,
+};
+
+static void fio_init fio_sec_register(void)
+{
+    register_ioengine(&ioengine);
+}
+
+static void fio_exit fio_sec_unregister(void)
+{
+    unregister_ioengine(&ioengine);
+}

fio_engine.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 // FIO engine to test Blockstore
 //
 // Initialize storage for tests:
@@ -23,6 +26,7 @@
 
 #include "blockstore.h"
 extern "C" {
+#define CONFIG_HAVE_GETTID
 #define CONFIG_PWRITEV2
 #include "fio/fio.h"
 #include "fio/optgroup.h"
@@ -100,7 +104,7 @@ static void bs_cleanup(struct thread_data *td)
                 bsd->ringloop->loop();
                 if (bsd->bs->is_safe_to_stop())
                     goto safe;
-            } while (bsd->ringloop->get_loop_again());
+            } while (bsd->ringloop->has_work());
             bsd->ringloop->wait();
         }
     safe:
@@ -289,7 +293,7 @@ static int bs_invalidate(struct thread_data *td, struct fio_file *f)
 }
 
 struct ioengine_ops ioengine = {
-    .name               = "microceph_blockstore",
+    .name               = "vitastor_blockstore",
     .version            = FIO_IOOPS_VERSION,
     .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
     .setup              = bs_setup,

fio_sec_osd.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 // FIO engine to test Blockstore through Secondary OSD interface
 //
 // Prepare storage like in fio_engine.cpp, then start OSD with ./osd, then test it
@@ -5,7 +8,7 @@
 // Random write:
 //
 // fio -thread -ioengine=./libfio_sec_osd.so -name=test -bs=4k -direct=1 -fsync=16 -iodepth=16 -rw=randwrite \
-//     -host=127.0.0.1 -port=11203 [-single_primary=1] -size=1000M
+//     -host=127.0.0.1 -port=11203 [-block_size_order=17] [-single_primary=1] -size=1000M
 //
 // Linear write:
 //
@@ -28,6 +31,7 @@
 #include "rw_blocking.h"
 #include "osd_ops.h"
 extern "C" {
+#define CONFIG_HAVE_GETTID
 #define CONFIG_PWRITEV2
 #include "fio/fio.h"
 #include "fio/optgroup.h"
@@ -52,6 +56,7 @@ struct sec_options
     int port = 0;
     int single_primary = 0;
     int trace = 0;
+    int block_order = 17;
 };
 
 static struct fio_option options[] = {
@@ -73,6 +78,15 @@ static struct fio_option options[] = {
         .category = FIO_OPT_C_ENGINE,
         .group  = FIO_OPT_G_FILENAME,
     },
+    {
+        .name   = "block_size_order",
+        .lname  = "Blockstore block size order",
+        .type   = FIO_OPT_INT,
+        .off1   = offsetof(struct sec_options, block_order),
+        .help   = "Blockstore block size order (size = 2^order)",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
     {
         .name   = "single_primary",
         .lname  = "Single Primary",
@@ -139,6 +153,8 @@ static int sec_init(struct thread_data *td)
 {
     sec_options *o = (sec_options*)td->eo;
     sec_data *bsd = (sec_data*)td->io_ops_data;
+    bsd->block_order = o->block_order == 0 ? 17 : o->block_order;
+    bsd->block_size = 1 << o->block_order;
 
     struct sockaddr_in addr;
     int r;
@@ -192,7 +208,7 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
     case DDIR_READ:
         if (!opt->single_primary)
         {
-            op.hdr.opcode = OSD_OP_SECONDARY_READ;
+            op.hdr.opcode = OSD_OP_SEC_READ;
             op.sec_rw.oid = {
                 .inode = 1,
                 .stripe = io->offset >> bsd->block_order,
@@ -213,7 +229,7 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
     case DDIR_WRITE:
         if (!opt->single_primary)
         {
-            op.hdr.opcode = OSD_OP_SECONDARY_WRITE;
+            op.hdr.opcode = OSD_OP_SEC_WRITE;
             op.sec_rw.oid = {
                 .inode = 1,
                 .stripe = io->offset >> bsd->block_order,
@@ -368,7 +384,7 @@ static int sec_invalidate(struct thread_data *td, struct fio_file *f)
 }
 
 struct ioengine_ops ioengine = {
-    .name               = "microceph_secondary_osd",
+    .name               = "vitastor_secondary_osd",
     .version            = FIO_IOOPS_VERSION,
     .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
     .setup              = sec_setup,

http_client.cpp

@@ -0,0 +1,691 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include <netinet/tcp.h>
+#include <sys/epoll.h>
+
+#include <net/if.h>
+#include <arpa/inet.h>
+#include <ifaddrs.h>
+
+#include <ctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include "json11/json11.hpp"
+#include "http_client.h"
+#include "timerfd_manager.h"
+
+#define READ_BUFFER_SIZE 9000
+
+static int extract_port(std::string & host);
+static std::string strtolower(const std::string & in);
+static std::string trim(const std::string & in);
+static std::string ws_format_frame(int type, uint64_t size);
+static bool ws_parse_frame(std::string & buf, int & type, std::string & res);
+
+// FIXME: Use keepalive
+struct http_co_t
+{
+    timerfd_manager_t *tfd;
+
+    int request_timeout = 0;
+    std::string host;
+    std::string request;
+    std::string ws_outbox;
+    std::string response;
+    bool want_streaming;
+
+    http_response_t parsed;
+    uint64_t target_response_size = 0;
+
+    int state = 0;
+    int peer_fd = -1;
+    int timeout_id = -1;
+    int epoll_events = 0;
+    int sent = 0;
+    std::vector<char> rbuf;
+    iovec read_iov, send_iov;
+    msghdr read_msg = { 0 }, send_msg = { 0 };
+
+    std::function<void(const http_response_t*)> callback;
+
+    websocket_t ws;
+
+    int onstack = 0;
+    bool ended = false;
+
+    ~http_co_t();
+    inline void stackin() { onstack++; }
+    inline void stackout() { onstack--; if (!onstack && ended) end(); }
+    inline void end() { ended = true; if (!onstack) { delete this; } }
+    void start_connection();
+    void handle_events();
+    void handle_connect_result();
+    void submit_read();
+    void submit_send();
+    bool handle_read();
+    void post_message(int type, const std::string & msg);
+};
+
+#define HTTP_CO_CONNECTING 1
+#define HTTP_CO_SENDING_REQUEST 2
+#define HTTP_CO_REQUEST_SENT 3
+#define HTTP_CO_HEADERS_RECEIVED 4
+#define HTTP_CO_WEBSOCKET 5
+#define HTTP_CO_CHUNKED 6
+
+#define DEFAULT_TIMEOUT 5000
+
+void http_request(timerfd_manager_t *tfd, const std::string & host, const std::string & request,
+    const http_options_t & options, std::function<void(const http_response_t *response)> callback)
+{
+    http_co_t *handler = new http_co_t();
+    handler->request_timeout = options.timeout < 0 ? 0 : (options.timeout == 0 ? DEFAULT_TIMEOUT : options.timeout);
+    handler->want_streaming = options.want_streaming;
+    handler->tfd = tfd;
+    handler->host = host;
+    handler->request = request;
+    handler->callback = callback;
+    handler->ws.co = handler;
+    handler->start_connection();
+}
+
+void http_request_json(timerfd_manager_t *tfd, const std::string & host, const std::string & request,
+    int timeout, std::function<void(std::string, json11::Json r)> callback)
+{
+    http_request(tfd, host, request, { .timeout = timeout }, [callback](const http_response_t* res)
+    {
+        if (res->error_code != 0)
+        {
+            callback("Error code: "+std::to_string(res->error_code)+" ("+std::string(strerror(res->error_code))+")", json11::Json());
+            return;
+        }
+        if (res->status_code != 200)
+        {
+            callback("HTTP "+std::to_string(res->status_code)+" "+res->status_line+" body: "+trim(res->body), json11::Json());
+            return;
+        }
+        std::string json_err;
+        json11::Json data = json11::Json::parse(res->body, json_err);
+        if (json_err != "")
+        {
+            callback("Bad JSON: "+json_err+" (response: "+trim(res->body)+")", json11::Json());
+            return;
+        }
+        callback(std::string(), data);
+    });
+}
+
+websocket_t* open_websocket(timerfd_manager_t *tfd, const std::string & host, const std::string & path,
+    int timeout, std::function<void(const http_response_t *msg)> callback)
+{
+    std::string request = "GET "+path+" HTTP/1.1\r\n"
+        "Host: "+host+"\r\n"
+        "Upgrade: websocket\r\n"
+        "Connection: upgrade\r\n"
+        "Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==\r\n"
+        "Sec-WebSocket-Version: 13\r\n"
+        "\r\n";
+    http_co_t *handler = new http_co_t();
+    handler->request_timeout = timeout < 0 ? -1 : (timeout == 0 ? DEFAULT_TIMEOUT : timeout);
+    handler->want_streaming = false;
+    handler->tfd = tfd;
+    handler->host = host;
+    handler->request = request;
+    handler->callback = callback;
+    handler->ws.co = handler;
+    handler->start_connection();
+    return &handler->ws;
+}
+
+void websocket_t::post_message(int type, const std::string & msg)
+{
+    co->post_message(type, msg);
+}
+
+void websocket_t::close()
+{
+    co->end();
+}
+
+http_co_t::~http_co_t()
+{
+    if (timeout_id >= 0)
+    {
+        tfd->clear_timer(timeout_id);
+        timeout_id = -1;
+    }
+    if (peer_fd >= 0)
+    {
+        tfd->set_fd_handler(peer_fd, false, NULL);
+        close(peer_fd);
+        peer_fd = -1;
+    }
+    if (parsed.headers["transfer-encoding"] == "chunked")
+    {
+        int prev = 0, pos = 0;
+        while ((pos = response.find("\r\n", prev)) >= prev)
+        {
+            uint64_t len = strtoull(response.c_str()+prev, NULL, 16);
+            parsed.body += response.substr(pos+2, len);
+            prev = pos+2+len+2;
+        }
+    }
+    else
+    {
+        std::swap(parsed.body, response);
+    }
+    parsed.eof = true;
+    callback(&parsed);
+}
+
+void http_co_t::start_connection()
+{
+    stackin();
+    int port = extract_port(host);
+    struct sockaddr_in addr;
+    int r;
+    if ((r = inet_pton(AF_INET, host.c_str(), &addr.sin_addr)) != 1)
+    {
+        parsed.error_code = ENXIO;
+        stackout();
+        end();
+        return;
+    }
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port ? port : 80);
+    peer_fd = socket(AF_INET, SOCK_STREAM, 0);
+    if (peer_fd < 0)
+    {
+        parsed.error_code = errno;
+        stackout();
+        end();
+        return;
+    }
+    fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL, 0) | O_NONBLOCK);
+    if (request_timeout > 0)
+    {
+        timeout_id = tfd->set_timer(request_timeout, false, [this](int timer_id)
+        {
+            if (response.length() == 0)
+            {
+                parsed.error_code = ETIME;
+            }
+            end();
+        });
+    }
+    epoll_events = 0;
+    // Finally call connect
+    r = ::connect(peer_fd, (sockaddr*)&addr, sizeof(addr));
+    if (r < 0 && errno != EINPROGRESS)
+    {
+        parsed.error_code = errno;
+        stackout();
+        end();
+        return;
+    }
+    tfd->set_fd_handler(peer_fd, true, [this](int peer_fd, int epoll_events)
+    {
+        this->epoll_events |= epoll_events;
+        handle_events();
+    });
+    state = HTTP_CO_CONNECTING;
+    stackout();
+}
+
+void http_co_t::handle_events()
+{
+    stackin();
+    while (epoll_events)
+    {
+        if (state == HTTP_CO_CONNECTING)
+        {
+            handle_connect_result();
+        }
+        else
+        {
+            epoll_events &= ~EPOLLOUT;
+            if (epoll_events & EPOLLIN)
+            {
+                submit_read();
+            }
+            else if (epoll_events & (EPOLLRDHUP|EPOLLERR))
+            {
+                end();
+                break;
+            }
+        }
+    }
+    stackout();
+}
+
+void http_co_t::handle_connect_result()
+{
+    stackin();
+    int result = 0;
+    socklen_t result_len = sizeof(result);
+    if (getsockopt(peer_fd, SOL_SOCKET, SO_ERROR, &result, &result_len) < 0)
+    {
+        result = errno;
+    }
+    if (result != 0)
+    {
+        parsed.error_code = result;
+        stackout();
+        end();
+        return;
+    }
+    int one = 1;
+    setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
+    tfd->set_fd_handler(peer_fd, false, [this](int peer_fd, int epoll_events)
+    {
+        this->epoll_events |= epoll_events;
+        handle_events();
+    });
+    state = HTTP_CO_SENDING_REQUEST;
+    submit_send();
+    stackout();
+}
+
+void http_co_t::submit_read()
+{
+    stackin();
+    int res;
+    if (rbuf.size() != READ_BUFFER_SIZE)
+    {
+        rbuf.resize(READ_BUFFER_SIZE);
+    }
+    read_iov = { .iov_base = rbuf.data(), .iov_len = READ_BUFFER_SIZE };
+    read_msg.msg_iov = &read_iov;
+    read_msg.msg_iovlen = 1;
+    res = recvmsg(peer_fd, &read_msg, 0);
+    if (res < 0)
+    {
+        res = -errno;
+    }
+    if (res == -EAGAIN)
+    {
+        epoll_events = epoll_events & ~EPOLLIN;
+    }
+    else if (res <= 0)
+    {
+        // < 0 means error, 0 means EOF
+        if (!res)
+            epoll_events = epoll_events & ~EPOLLIN;
+        end();
+    }
+    else
+    {
+        response += std::string(rbuf.data(), res);
+        handle_read();
+    }
+    stackout();
+}
+
+void http_co_t::submit_send()
+{
+    stackin();
+    int res;
+again:
+    if (sent < request.size())
+    {
+        send_iov = (iovec){ .iov_base = (void*)(request.c_str()+sent), .iov_len = request.size()-sent };
+        send_msg.msg_iov = &send_iov;
+        send_msg.msg_iovlen = 1;
+        res = sendmsg(peer_fd, &send_msg, MSG_NOSIGNAL);
+        if (res < 0)
+        {
+            res = -errno;
+        }
+        if (res == -EAGAIN)
+        {
+            res = 0;
+        }
+        else if (res < 0)
+        {
+            stackout();
+            end();
+            return;
+        }
+        sent += res;
+        if (state == HTTP_CO_SENDING_REQUEST)
+        {
+            if (sent >= request.size())
+            {
+                state = HTTP_CO_REQUEST_SENT;
+            }
+            else
+                goto again;
+        }
+        else if (state == HTTP_CO_WEBSOCKET)
+        {
+            request = request.substr(sent);
+            sent = 0;
+            goto again;
+        }
+    }
+    stackout();
+}
+
+bool http_co_t::handle_read()
+{
+    stackin();
+    if (state == HTTP_CO_REQUEST_SENT)
+    {
+        int pos = response.find("\r\n\r\n");
+        if (pos >= 0)
+        {
+            if (timeout_id >= 0)
+            {
+                tfd->clear_timer(timeout_id);
+                timeout_id = -1;
+            }
+            state = HTTP_CO_HEADERS_RECEIVED;
+            parse_http_headers(response, &parsed);
+            if (parsed.status_code == 101 &&
+                parsed.headers.find("sec-websocket-accept") != parsed.headers.end() &&
+                parsed.headers["upgrade"] == "websocket" &&
+                parsed.headers["connection"] == "upgrade")
+            {
+                // Don't care about validating the key
+                state = HTTP_CO_WEBSOCKET;
+                request = ws_outbox;
+                ws_outbox = "";
+                sent = 0;
+                submit_send();
+            }
+            else if (parsed.headers["transfer-encoding"] == "chunked")
+            {
+                state = HTTP_CO_CHUNKED;
+            }
+            else if (parsed.headers["connection"] != "close")
+            {
+                target_response_size = stoull_full(parsed.headers["content-length"]);
+                if (!target_response_size)
+                {
+                    // Sorry, unsupported response
+                    stackout();
+                    end();
+                    return false;
+                }
+            }
+        }
+    }
+    if (state == HTTP_CO_HEADERS_RECEIVED && target_response_size > 0 && response.size() >= target_response_size)
+    {
+        stackout();
+        end();
+        return false;
+    }
+    if (state == HTTP_CO_CHUNKED && response.size() > 0)
+    {
+        int prev = 0, pos = 0;
+        while ((pos = response.find("\r\n", prev)) >= prev)
+        {
+            uint64_t len = strtoull(response.c_str()+prev, NULL, 16);
+            if (!len)
+            {
+                // Zero length chunk indicates EOF
+                parsed.eof = true;
+                break;
+            }
+            if (response.size() < pos+2+len+2)
+            {
+                break;
+            }
+            parsed.body += response.substr(pos+2, len);
+            prev = pos+2+len+2;
+        }
+        if (prev > 0)
+        {
+            response = response.substr(prev);
+        }
+        if (parsed.eof)
+        {
+            stackout();
+            end();
+            return false;
+        }
+        if (want_streaming && parsed.body.size() > 0)
+        {
+            callback(&parsed);
+            parsed.body = "";
+        }
+    }
+    if (state == HTTP_CO_WEBSOCKET && response.size() > 0)
+    {
+        while (ws_parse_frame(response, parsed.ws_msg_type, parsed.body))
+        {
+            callback(&parsed);
+            parsed.body = "";
+        }
+    }
+    stackout();
+    return true;
+}
+
+void http_co_t::post_message(int type, const std::string & msg)
+{
+    stackin();
+    if (state == HTTP_CO_WEBSOCKET)
+    {
+        request += ws_format_frame(type, msg.size());
+        request += msg;
+        submit_send();
+    }
+    else
+    {
+        ws_outbox += ws_format_frame(type, msg.size());
+        ws_outbox += msg;
+    }
+    stackout();
+}
+
+uint64_t stoull_full(const std::string & str, int base)
+{
+    if (isspace(str[0]))
+    {
+        return 0;
+    }
+    char *end = NULL;
+    uint64_t r = strtoull(str.c_str(), &end, base);
+    if (end != str.c_str()+str.length())
+    {
+        return 0;
+    }
+    return r;
+}
+
+void parse_http_headers(std::string & res, http_response_t *parsed)
+{
+    int pos = res.find("\r\n");
+    pos = pos < 0 ? res.length() : pos+2;
+    std::string status_line = res.substr(0, pos);
+    int http_version;
+    char *status_text = NULL;
+    sscanf(status_line.c_str(), "HTTP/1.%d %d %ms", &http_version, &parsed->status_code, &status_text);
+    if (status_text)
+    {
+        parsed->status_line = status_text;
+        // %ms = allocate a buffer
+        free(status_text);
+        status_text = NULL;
+    }
+    int prev = pos;
+    while ((pos = res.find("\r\n", prev)) >= prev)
+    {
+        if (pos == prev)
+        {
+            res = res.substr(pos+2);
+            break;
+        }
+        std::string header = res.substr(prev, pos-prev);
+        int p2 = header.find(":");
+        if (p2 >= 0)
+        {
+            std::string key = strtolower(header.substr(0, p2));
+            int p3 = p2+1;
+            while (p3 < header.length() && isblank(header[p3]))
+                p3++;
+            parsed->headers[key] = key == "connection" || key == "upgrade" || key == "transfer-encoding"
+                ? strtolower(header.substr(p3)) : header.substr(p3);
+        }
+        prev = pos+2;
+    }
+}
+
+static std::string ws_format_frame(int type, uint64_t size)
+{
+    // Always zero mask
+    std::string res;
+    int p = 0;
+    res.resize(2 + (size >= 126 ? 2 : 0) + (size >= 65536 ? 6 : 0) + /*mask*/4);
+    res[p++] = 0x80 | type;
+    if (size < 126)
+        res[p++] = size | /*mask*/0x80;
+    else if (size < 65536)
+    {
+        res[p++] = 126 | /*mask*/0x80;
+        res[p++] = (size >> 8) & 0xFF;
+        res[p++] = (size >> 0) & 0xFF;
+    }
+    else
+    {
+        res[p++] = 127 | /*mask*/0x80;
+        res[p++] = (size >> 56) & 0xFF;
+        res[p++] = (size >> 48) & 0xFF;
+        res[p++] = (size >> 40) & 0xFF;
+        res[p++] = (size >> 32) & 0xFF;
+        res[p++] = (size >> 24) & 0xFF;
+        res[p++] = (size >> 16) & 0xFF;
+        res[p++] = (size >>  8) & 0xFF;
+        res[p++] = (size >>  0) & 0xFF;
+    }
+    res[p++] = 0;
+    res[p++] = 0;
+    res[p++] = 0;
+    res[p++] = 0;
+    return res;
+}
+
+static bool ws_parse_frame(std::string & buf, int & type, std::string & res)
+{
+    uint64_t hdr = 2;
+    if (buf.size() < hdr)
+    {
+        return false;
+    }
+    type = buf[0] & ~0x80;
+    bool mask = !!(buf[1] & 0x80);
+    hdr += mask ? 4 : 0;
+    uint64_t len = ((uint8_t)buf[1] & ~0x80);
+    if (len == 126)
+    {
+        hdr += 2;
+        if (buf.size() < hdr)
+        {
+            return false;
+        }
+        len = ((uint64_t)(uint8_t)buf[2] << 8) | ((uint64_t)(uint8_t)buf[3] << 0);
+    }
+    else if (len == 127)
+    {
+        hdr += 8;
+        if (buf.size() < hdr)
+        {
+            return false;
+        }
+        len = ((uint64_t)(uint8_t)buf[2] << 56) |
+            ((uint64_t)(uint8_t)buf[3] << 48) |
+            ((uint64_t)(uint8_t)buf[4] << 40) |
+            ((uint64_t)(uint8_t)buf[5] << 32) |
+            ((uint64_t)(uint8_t)buf[6] << 24) |
+            ((uint64_t)(uint8_t)buf[7] << 16) |
+            ((uint64_t)(uint8_t)buf[8] << 8) |
+            ((uint64_t)(uint8_t)buf[9] << 0);
+    }
+    if (buf.size() < hdr+len)
+    {
+        return false;
+    }
+    if (mask)
+    {
+        for (int i = 0; i < len; i++)
+            buf[hdr+i] ^= buf[hdr-4+(i & 3)];
+    }
+    res += buf.substr(hdr, len);
+    buf = buf.substr(hdr+len);
+    return true;
+}
+
+std::vector<std::string> getifaddr_list(bool include_v6)
+{
+    std::vector<std::string> addresses;
+    ifaddrs *list, *ifa;
+    if (getifaddrs(&list) == -1)
+    {
+        throw std::runtime_error(std::string("getifaddrs: ") + strerror(errno));
+    }
+    for (ifa = list; ifa != NULL; ifa = ifa->ifa_next)
+    {
+        if (!ifa->ifa_addr)
+        {
+            continue;
+        }
+        int family = ifa->ifa_addr->sa_family;
+        if ((family == AF_INET || family == AF_INET6 && include_v6) &&
+            (ifa->ifa_flags & (IFF_UP | IFF_RUNNING | IFF_LOOPBACK)) == (IFF_UP | IFF_RUNNING))
+        {
+            void *addr_ptr;
+            if (family == AF_INET)
+                addr_ptr = &((sockaddr_in *)ifa->ifa_addr)->sin_addr;
+            else
+                addr_ptr = &((sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
+            char addr[INET6_ADDRSTRLEN];
+            if (!inet_ntop(family, addr_ptr, addr, INET6_ADDRSTRLEN))
+            {
+                throw std::runtime_error(std::string("inet_ntop: ") + strerror(errno));
+            }
+            addresses.push_back(std::string(addr));
+        }
+    }
+    freeifaddrs(list);
+    return addresses;
+}
+
+static int extract_port(std::string & host)
+{
+    int port = 0;
+    int pos = 0;
+    if ((pos = host.find(':')) >= 0)
+    {
+        port = strtoull(host.c_str() + pos + 1, NULL, 10);
+        if (port >= 0x10000)
+        {
+            port = 0;
+        }
+        host = host.substr(0, pos);
+    }
+    return port;
+}
+
+static std::string strtolower(const std::string & in)
+{
+    std::string s = in;
+    for (int i = 0; i < s.length(); i++)
+    {
+        s[i] = tolower(s[i]);
+    }
+    return s;
+}
+
+static std::string trim(const std::string & in)
+{
+    int begin = in.find_first_not_of(" \n\r\t");
+    if (begin == -1)
+        return "";
+    int end = in.find_last_not_of(" \n\r\t");
+    return in.substr(begin, end+1-begin);
+}

http_client.h

@@ -0,0 +1,59 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+#include <string>
+#include <vector>
+#include <map>
+#include <functional>
+#include "json11/json11.hpp"
+
+#define WS_CONTINUATION 0
+#define WS_TEXT 1
+#define WS_BINARY 2
+#define WS_CLOSE 8
+#define WS_PING 9
+#define WS_PONG 10
+
+class timerfd_manager_t;
+
+struct http_options_t
+{
+    int timeout;
+    bool want_streaming;
+};
+
+struct http_response_t
+{
+    bool eof = false;
+    int error_code = 0;
+    int status_code = 0;
+    std::string status_line;
+    std::map<std::string, std::string> headers;
+    int ws_msg_type = -1;
+    std::string body;
+};
+
+struct http_co_t;
+
+struct websocket_t
+{
+    http_co_t *co;
+    void post_message(int type, const std::string & msg);
+    void close();
+};
+
+void parse_http_headers(std::string & res, http_response_t *parsed);
+
+std::vector<std::string> getifaddr_list(bool include_v6 = false);
+
+uint64_t stoull_full(const std::string & str, int base = 10);
+
+void http_request(timerfd_manager_t *tfd, const std::string & host, const std::string & request,
+    const http_options_t & options, std::function<void(const http_response_t *response)> callback);
+
+void http_request_json(timerfd_manager_t *tfd, const std::string & host, const std::string & request,
+    int timeout, std::function<void(std::string, json11::Json r)> callback);
+
+websocket_t* open_websocket(timerfd_manager_t *tfd, const std::string & host, const std::string & path,
+    int timeout, std::function<void(const http_response_t *msg)> callback);

json11

@@ -0,0 +1 @@
+Subproject commit 97f06cb20c1e136fd37d58fb40f57dd8f8a3a4a7

lambda_size.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <iostream>
 #include <functional>
 #include <array>

malloc_or_die.h

@@ -0,0 +1,50 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include <malloc.h>
+
+inline void* memalign_or_die(size_t alignment, size_t size)
+{
+    void *buf = memalign(alignment, size);
+    if (!buf)
+    {
+        printf("Failed to allocate %lu bytes\n", size);
+        exit(1);
+    }
+    return buf;
+}
+
+inline void* malloc_or_die(size_t size)
+{
+    void *buf = malloc(size);
+    if (!buf)
+    {
+        printf("Failed to allocate %lu bytes\n", size);
+        exit(1);
+    }
+    return buf;
+}
+
+inline void* realloc_or_die(void *ptr, size_t size)
+{
+    void *buf = realloc(ptr, size);
+    if (!buf)
+    {
+        printf("Failed to allocate %lu bytes\n", size);
+        exit(1);
+    }
+    return buf;
+}
+
+inline void* calloc_or_die(size_t nmemb, size_t size)
+{
+    void *buf = calloc(nmemb, size);
+    if (!buf)
+    {
+        printf("Failed to allocate %lu bytes\n", size * nmemb);
+        exit(1);
+    }
+    return buf;
+}

messenger.cpp

@@ -0,0 +1,412 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/epoll.h>
+#include <netinet/tcp.h>
+
+#include "messenger.h"
+
+osd_op_t::~osd_op_t()
+{
+    assert(!bs_op);
+    assert(!op_data);
+    if (rmw_buf)
+    {
+        free(rmw_buf);
+    }
+    if (buf)
+    {
+        // Note: reusing osd_op_t WILL currently lead to memory leaks
+        // So we don't reuse it, but free it every time
+        free(buf);
+    }
+}
+
+osd_messenger_t::~osd_messenger_t()
+{
+    while (clients.size() > 0)
+    {
+        stop_client(clients.begin()->first);
+    }
+}
+
+void osd_messenger_t::connect_peer(uint64_t peer_osd, json11::Json peer_state)
+{
+    if (wanted_peers.find(peer_osd) == wanted_peers.end())
+    {
+        wanted_peers[peer_osd] = (osd_wanted_peer_t){
+            .address_list = peer_state["addresses"],
+            .port = (int)peer_state["port"].int64_value(),
+        };
+    }
+    else
+    {
+        wanted_peers[peer_osd].address_list = peer_state["addresses"];
+        wanted_peers[peer_osd].port = (int)peer_state["port"].int64_value();
+    }
+    wanted_peers[peer_osd].address_changed = true;
+    if (!wanted_peers[peer_osd].connecting &&
+        (time(NULL) - wanted_peers[peer_osd].last_connect_attempt) >= peer_connect_interval)
+    {
+        try_connect_peer(peer_osd);
+    }
+}
+
+void osd_messenger_t::try_connect_peer(uint64_t peer_osd)
+{
+    auto wp_it = wanted_peers.find(peer_osd);
+    if (wp_it == wanted_peers.end())
+    {
+        return;
+    }
+    if (osd_peer_fds.find(peer_osd) != osd_peer_fds.end())
+    {
+        wanted_peers.erase(peer_osd);
+        return;
+    }
+    auto & wp = wp_it->second;
+    if (wp.address_index >= wp.address_list.array_items().size())
+    {
+        return;
+    }
+    wp.cur_addr = wp.address_list[wp.address_index].string_value();
+    wp.cur_port = wp.port;
+    wp.connecting = true;
+    try_connect_peer_addr(peer_osd, wp.cur_addr.c_str(), wp.cur_port);
+}
+
+void osd_messenger_t::try_connect_peer_addr(osd_num_t peer_osd, const char *peer_host, int peer_port)
+{
+    struct sockaddr_in addr;
+    int r;
+    if ((r = inet_pton(AF_INET, peer_host, &addr.sin_addr)) != 1)
+    {
+        on_connect_peer(peer_osd, -EINVAL);
+        return;
+    }
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(peer_port ? peer_port : 11203);
+    int peer_fd = socket(AF_INET, SOCK_STREAM, 0);
+    if (peer_fd < 0)
+    {
+        on_connect_peer(peer_osd, -errno);
+        return;
+    }
+    fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL, 0) | O_NONBLOCK);
+    int timeout_id = -1;
+    if (peer_connect_timeout > 0)
+    {
+        timeout_id = tfd->set_timer(1000*peer_connect_timeout, false, [this, peer_fd](int timer_id)
+        {
+            osd_num_t peer_osd = clients[peer_fd].osd_num;
+            stop_client(peer_fd);
+            on_connect_peer(peer_osd, -EIO);
+            return;
+        });
+    }
+    r = connect(peer_fd, (sockaddr*)&addr, sizeof(addr));
+    if (r < 0 && errno != EINPROGRESS)
+    {
+        close(peer_fd);
+        on_connect_peer(peer_osd, -errno);
+        return;
+    }
+    assert(peer_osd != this->osd_num);
+    clients[peer_fd] = (osd_client_t){
+        .peer_addr = addr,
+        .peer_port = peer_port,
+        .peer_fd = peer_fd,
+        .peer_state = PEER_CONNECTING,
+        .connect_timeout_id = timeout_id,
+        .osd_num = peer_osd,
+        .in_buf = malloc_or_die(receive_buffer_size),
+    };
+    tfd->set_fd_handler(peer_fd, true, [this](int peer_fd, int epoll_events)
+    {
+        // Either OUT (connected) or HUP
+        handle_connect_epoll(peer_fd);
+    });
+}
+
+void osd_messenger_t::handle_connect_epoll(int peer_fd)
+{
+    auto & cl = clients[peer_fd];
+    if (cl.connect_timeout_id >= 0)
+    {
+        tfd->clear_timer(cl.connect_timeout_id);
+        cl.connect_timeout_id = -1;
+    }
+    osd_num_t peer_osd = cl.osd_num;
+    int result = 0;
+    socklen_t result_len = sizeof(result);
+    if (getsockopt(peer_fd, SOL_SOCKET, SO_ERROR, &result, &result_len) < 0)
+    {
+        result = errno;
+    }
+    if (result != 0)
+    {
+        stop_client(peer_fd);
+        on_connect_peer(peer_osd, -result);
+        return;
+    }
+    int one = 1;
+    setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
+    cl.peer_state = PEER_CONNECTED;
+    tfd->set_fd_handler(peer_fd, false, [this](int peer_fd, int epoll_events)
+    {
+        handle_peer_epoll(peer_fd, epoll_events);
+    });
+    // Check OSD number
+    check_peer_config(cl);
+}
+
+void osd_messenger_t::handle_peer_epoll(int peer_fd, int epoll_events)
+{
+    // Mark client as ready (i.e. some data is available)
+    if (epoll_events & EPOLLRDHUP)
+    {
+        // Stop client
+        printf("[OSD %lu] client %d disconnected\n", this->osd_num, peer_fd);
+        stop_client(peer_fd);
+    }
+    else if (epoll_events & EPOLLIN)
+    {
+        // Mark client as ready (i.e. some data is available)
+        auto & cl = clients[peer_fd];
+        cl.read_ready++;
+        if (cl.read_ready == 1)
+        {
+            read_ready_clients.push_back(cl.peer_fd);
+            if (ringloop)
+                ringloop->wakeup();
+            else
+                read_requests();
+        }
+    }
+}
+
+void osd_messenger_t::on_connect_peer(osd_num_t peer_osd, int peer_fd)
+{
+    auto & wp = wanted_peers.at(peer_osd);
+    wp.connecting = false;
+    if (peer_fd < 0)
+    {
+        printf("Failed to connect to peer OSD %lu address %s port %d: %s\n", peer_osd, wp.cur_addr.c_str(), wp.cur_port, strerror(-peer_fd));
+        if (wp.address_changed)
+        {
+            wp.address_changed = false;
+            wp.address_index = 0;
+            try_connect_peer(peer_osd);
+        }
+        else if (wp.address_index < wp.address_list.array_items().size()-1)
+        {
+            // Try other addresses
+            wp.address_index++;
+            try_connect_peer(peer_osd);
+        }
+        else
+        {
+            // Retry again in <peer_connect_interval> seconds
+            wp.last_connect_attempt = time(NULL);
+            wp.address_index = 0;
+            tfd->set_timer(1000*peer_connect_interval, false, [this, peer_osd](int)
+            {
+                try_connect_peer(peer_osd);
+            });
+        }
+        return;
+    }
+    printf("Connected with peer OSD %lu (fd %d)\n", peer_osd, peer_fd);
+    wanted_peers.erase(peer_osd);
+    repeer_pgs(peer_osd);
+}
+
+void osd_messenger_t::check_peer_config(osd_client_t & cl)
+{
+    osd_op_t *op = new osd_op_t();
+    op->op_type = OSD_OP_OUT;
+    op->peer_fd = cl.peer_fd;
+    op->req = {
+        .show_conf = {
+            .header = {
+                .magic = SECONDARY_OSD_OP_MAGIC,
+                .id = this->next_subop_id++,
+                .opcode = OSD_OP_SHOW_CONFIG,
+            },
+        },
+    };
+    op->callback = [this](osd_op_t *op)
+    {
+        osd_client_t & cl = clients[op->peer_fd];
+        std::string json_err;
+        json11::Json config;
+        bool err = false;
+        if (op->reply.hdr.retval < 0)
+        {
+            err = true;
+            printf("Failed to get config from OSD %lu (retval=%ld), disconnecting peer\n", cl.osd_num, op->reply.hdr.retval);
+        }
+        else
+        {
+            config = json11::Json::parse(std::string((char*)op->buf), json_err);
+            if (json_err != "")
+            {
+                err = true;
+                printf("Failed to get config from OSD %lu: bad JSON: %s, disconnecting peer\n", cl.osd_num, json_err.c_str());
+            }
+            else if (config["osd_num"].uint64_value() != cl.osd_num)
+            {
+                err = true;
+                printf("Connected to OSD %lu instead of OSD %lu, peer state is outdated, disconnecting peer\n", config["osd_num"].uint64_value(), cl.osd_num);
+            }
+        }
+        if (err)
+        {
+            osd_num_t osd_num = cl.osd_num;
+            stop_client(op->peer_fd);
+            on_connect_peer(osd_num, -1);
+            delete op;
+            return;
+        }
+        osd_peer_fds[cl.osd_num] = cl.peer_fd;
+        on_connect_peer(cl.osd_num, cl.peer_fd);
+        delete op;
+    };
+    outbox_push(op);
+}
+
+void osd_messenger_t::cancel_osd_ops(osd_client_t & cl)
+{
+    for (auto p: cl.sent_ops)
+    {
+        cancel_op(p.second);
+    }
+    cl.sent_ops.clear();
+    for (auto op: cl.outbox)
+    {
+        cancel_op(op);
+    }
+    cl.outbox.clear();
+    if (cl.write_op)
+    {
+        cancel_op(cl.write_op);
+        cl.write_op = NULL;
+    }
+}
+
+void osd_messenger_t::cancel_op(osd_op_t *op)
+{
+    if (op->op_type == OSD_OP_OUT)
+    {
+        op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
+        op->reply.hdr.id = op->req.hdr.id;
+        op->reply.hdr.opcode = op->req.hdr.opcode;
+        op->reply.hdr.retval = -EPIPE;
+        // Copy lambda to be unaffected by `delete op`
+        std::function<void(osd_op_t*)>(op->callback)(op);
+    }
+    else
+    {
+        // This function is only called in stop_client(), so it's fine to destroy the operation
+        delete op;
+    }
+}
+
+void osd_messenger_t::stop_client(int peer_fd)
+{
+    assert(peer_fd != 0);
+    auto it = clients.find(peer_fd);
+    if (it == clients.end())
+    {
+        return;
+    }
+    uint64_t repeer_osd = 0;
+    osd_client_t cl = it->second;
+    if (cl.peer_state == PEER_CONNECTED)
+    {
+        if (cl.osd_num)
+        {
+            // Reload configuration from etcd when the connection is dropped
+            printf("[OSD %lu] Stopping client %d (OSD peer %lu)\n", osd_num, peer_fd, cl.osd_num);
+            repeer_osd = cl.osd_num;
+        }
+        else
+        {
+            printf("[OSD %lu] Stopping client %d (regular client)\n", osd_num, peer_fd);
+        }
+    }
+    clients.erase(it);
+    tfd->set_fd_handler(peer_fd, false, NULL);
+    if (cl.osd_num)
+    {
+        osd_peer_fds.erase(cl.osd_num);
+        // Cancel outbound operations
+        cancel_osd_ops(cl);
+    }
+    if (cl.read_op)
+    {
+        delete cl.read_op;
+        cl.read_op = NULL;
+    }
+    for (auto rit = read_ready_clients.begin(); rit != read_ready_clients.end(); rit++)
+    {
+        if (*rit == peer_fd)
+        {
+            read_ready_clients.erase(rit);
+            break;
+        }
+    }
+    for (auto wit = write_ready_clients.begin(); wit != write_ready_clients.end(); wit++)
+    {
+        if (*wit == peer_fd)
+        {
+            write_ready_clients.erase(wit);
+            break;
+        }
+    }
+    free(cl.in_buf);
+    close(peer_fd);
+    if (repeer_osd)
+    {
+        repeer_pgs(repeer_osd);
+    }
+}
+
+void osd_messenger_t::accept_connections(int listen_fd)
+{
+    // Accept new connections
+    sockaddr_in addr;
+    socklen_t peer_addr_size = sizeof(addr);
+    int peer_fd;
+    while ((peer_fd = accept(listen_fd, (sockaddr*)&addr, &peer_addr_size)) >= 0)
+    {
+        assert(peer_fd != 0);
+        char peer_str[256];
+        printf("[OSD %lu] new client %d: connection from %s port %d\n", this->osd_num, peer_fd,
+            inet_ntop(AF_INET, &addr.sin_addr, peer_str, 256), ntohs(addr.sin_port));
+        fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL, 0) | O_NONBLOCK);
+        int one = 1;
+        setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
+        clients[peer_fd] = {
+            .peer_addr = addr,
+            .peer_port = ntohs(addr.sin_port),
+            .peer_fd = peer_fd,
+            .peer_state = PEER_CONNECTED,
+            .in_buf = malloc_or_die(receive_buffer_size),
+        };
+        // Add FD to epoll
+        tfd->set_fd_handler(peer_fd, false, [this](int peer_fd, int epoll_events)
+        {
+            handle_peer_epoll(peer_fd, epoll_events);
+        });
+        // Try to accept next connection
+        peer_addr_size = sizeof(addr);
+    }
+    if (peer_fd == -1 && errno != EAGAIN)
+    {
+        throw std::runtime_error(std::string("accept: ") + strerror(errno));
+    }
+}

messenger.h

@@ -0,0 +1,303 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+
+#include <set>
+#include <map>
+#include <deque>
+#include <vector>
+
+#include "malloc_or_die.h"
+#include "json11/json11.hpp"
+#include "osd_ops.h"
+#include "timerfd_manager.h"
+#include "ringloop.h"
+
+#define OSD_OP_IN 0
+#define OSD_OP_OUT 1
+
+#define CL_READ_HDR 1
+#define CL_READ_DATA 2
+#define CL_READ_REPLY_DATA 3
+#define CL_WRITE_READY 1
+#define CL_WRITE_REPLY 2
+#define OSD_OP_INLINE_BUF_COUNT 16
+
+#define PEER_CONNECTING 1
+#define PEER_CONNECTED 2
+
+#define DEFAULT_PEER_CONNECT_INTERVAL 5
+#define DEFAULT_PEER_CONNECT_TIMEOUT 5
+
+// Kind of a vector with small-list-optimisation
+struct osd_op_buf_list_t
+{
+    int count = 0, alloc = OSD_OP_INLINE_BUF_COUNT, done = 0;
+    iovec *buf = NULL;
+    iovec inline_buf[OSD_OP_INLINE_BUF_COUNT];
+
+    inline osd_op_buf_list_t()
+    {
+        buf = inline_buf;
+    }
+
+    inline osd_op_buf_list_t(const osd_op_buf_list_t & other)
+    {
+        buf = inline_buf;
+        append(other);
+    }
+
+    inline osd_op_buf_list_t & operator = (const osd_op_buf_list_t & other)
+    {
+        reset();
+        append(other);
+        return *this;
+    }
+
+    inline ~osd_op_buf_list_t()
+    {
+        if (buf && buf != inline_buf)
+        {
+            free(buf);
+        }
+    }
+
+    inline void reset()
+    {
+        count = 0;
+        done = 0;
+    }
+
+    inline iovec* get_iovec()
+    {
+        return buf + done;
+    }
+
+    inline int get_size()
+    {
+        return count - done;
+    }
+
+    inline void append(const osd_op_buf_list_t & other)
+    {
+        if (count+other.count > alloc)
+        {
+            if (buf == inline_buf)
+            {
+                int old = alloc;
+                alloc = (((count+other.count+15)/16)*16);
+                buf = (iovec*)malloc(sizeof(iovec) * alloc);
+                if (!buf)
+                {
+                    printf("Failed to allocate %lu bytes\n", sizeof(iovec) * alloc);
+                    exit(1);
+                }
+                memcpy(buf, inline_buf, sizeof(iovec) * old);
+            }
+            else
+            {
+                alloc = (((count+other.count+15)/16)*16);
+                buf = (iovec*)realloc(buf, sizeof(iovec) * alloc);
+                if (!buf)
+                {
+                    printf("Failed to allocate %lu bytes\n", sizeof(iovec) * alloc);
+                    exit(1);
+                }
+            }
+        }
+        for (int i = 0; i < other.count; i++)
+        {
+            buf[count++] = other.buf[i];
+        }
+    }
+
+    inline void push_back(void *nbuf, size_t len)
+    {
+        if (count >= alloc)
+        {
+            if (buf == inline_buf)
+            {
+                int old = alloc;
+                alloc = ((alloc/16)*16 + 1);
+                buf = (iovec*)malloc(sizeof(iovec) * alloc);
+                if (!buf)
+                {
+                    printf("Failed to allocate %lu bytes\n", sizeof(iovec) * alloc);
+                    exit(1);
+                }
+                memcpy(buf, inline_buf, sizeof(iovec)*old);
+            }
+            else
+            {
+                alloc = alloc < 16 ? 16 : (alloc+16);
+                buf = (iovec*)realloc(buf, sizeof(iovec) * alloc);
+                if (!buf)
+                {
+                    printf("Failed to allocate %lu bytes\n", sizeof(iovec) * alloc);
+                    exit(1);
+                }
+            }
+        }
+        buf[count++] = { .iov_base = nbuf, .iov_len = len };
+    }
+
+    inline void eat(int result)
+    {
+        while (result > 0 && done < count)
+        {
+            iovec & iov = buf[done];
+            if (iov.iov_len <= result)
+            {
+                result -= iov.iov_len;
+                done++;
+            }
+            else
+            {
+                iov.iov_len -= result;
+                iov.iov_base += result;
+                break;
+            }
+        }
+    }
+};
+
+struct blockstore_op_t;
+
+struct osd_primary_op_data_t;
+
+struct osd_op_t
+{
+    timespec tv_begin;
+    uint64_t op_type = OSD_OP_IN;
+    int peer_fd;
+    osd_any_op_t req;
+    osd_any_reply_t reply;
+    blockstore_op_t *bs_op = NULL;
+    void *buf = NULL;
+    void *rmw_buf = NULL;
+    osd_primary_op_data_t* op_data = NULL;
+    std::function<void(osd_op_t*)> callback;
+
+    osd_op_buf_list_t iov;
+
+    ~osd_op_t();
+};
+
+struct osd_client_t
+{
+    sockaddr_in peer_addr;
+    int peer_port;
+    int peer_fd;
+    int peer_state;
+    int connect_timeout_id = -1;
+    osd_num_t osd_num = 0;
+
+    void *in_buf = NULL;
+
+    // Read state
+    int read_ready = 0;
+    osd_op_t *read_op = NULL;
+    iovec read_iov;
+    msghdr read_msg;
+    int read_remaining = 0;
+    int read_state = 0;
+    osd_op_buf_list_t recv_list;
+
+    // Incoming operations
+    std::vector<osd_op_t*> received_ops;
+
+    // Outbound operations
+    std::deque<osd_op_t*> outbox;
+    std::map<int, osd_op_t*> sent_ops;
+
+    // PGs dirtied by this client's primary-writes
+    std::set<pool_pg_num_t> dirty_pgs;
+
+    // Write state
+    osd_op_t *write_op = NULL;
+    msghdr write_msg;
+    int write_state = 0;
+    osd_op_buf_list_t send_list;
+};
+
+struct osd_wanted_peer_t
+{
+    json11::Json address_list;
+    int port;
+    time_t last_connect_attempt;
+    bool connecting, address_changed;
+    int address_index;
+    std::string cur_addr;
+    int cur_port;
+};
+
+struct osd_op_stats_t
+{
+    uint64_t op_stat_sum[OSD_OP_MAX+1] = { 0 };
+    uint64_t op_stat_count[OSD_OP_MAX+1] = { 0 };
+    uint64_t op_stat_bytes[OSD_OP_MAX+1] = { 0 };
+    uint64_t subop_stat_sum[OSD_OP_MAX+1] = { 0 };
+    uint64_t subop_stat_count[OSD_OP_MAX+1] = { 0 };
+};
+
+struct osd_messenger_t
+{
+    timerfd_manager_t *tfd;
+    ring_loop_t *ringloop;
+
+    // osd_num_t is only for logging and asserts
+    osd_num_t osd_num;
+    // FIXME: make receive_buffer_size configurable
+    int receive_buffer_size = 64*1024;
+    int peer_connect_interval = DEFAULT_PEER_CONNECT_INTERVAL;
+    int peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT;
+    int log_level = 0;
+    bool use_sync_send_recv = false;
+
+    std::map<osd_num_t, osd_wanted_peer_t> wanted_peers;
+    std::map<uint64_t, int> osd_peer_fds;
+    uint64_t next_subop_id = 1;
+
+    std::map<int, osd_client_t> clients;
+    std::vector<int> read_ready_clients;
+    std::vector<int> write_ready_clients;
+    std::vector<std::function<void()>> set_immediate;
+
+    // op statistics
+    osd_op_stats_t stats;
+
+public:
+    void connect_peer(uint64_t osd_num, json11::Json peer_state);
+    void stop_client(int peer_fd);
+    void outbox_push(osd_op_t *cur_op);
+    std::function<void(osd_op_t*)> exec_op;
+    std::function<void(osd_num_t)> repeer_pgs;
+    void handle_peer_epoll(int peer_fd, int epoll_events);
+    void read_requests();
+    void send_replies();
+    void accept_connections(int listen_fd);
+    ~osd_messenger_t();
+
+protected:
+    void try_connect_peer(uint64_t osd_num);
+    void try_connect_peer_addr(osd_num_t peer_osd, const char *peer_host, int peer_port);
+    void handle_connect_epoll(int peer_fd);
+    void on_connect_peer(osd_num_t peer_osd, int peer_fd);
+    void check_peer_config(osd_client_t & cl);
+    void cancel_osd_ops(osd_client_t & cl);
+    void cancel_op(osd_op_t *op);
+
+    bool try_send(osd_client_t & cl);
+    void handle_send(int result, int peer_fd);
+
+    bool handle_read(int result, int peer_fd);
+    bool handle_finished_read(osd_client_t & cl);
+    void handle_op_hdr(osd_client_t *cl);
+    bool handle_reply_hdr(osd_client_t *cl);
+    void handle_reply_ready(osd_op_t *op);
+};

mon/PGUtil.js

@@ -0,0 +1,112 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+module.exports = {
+    scale_pg_count,
+};
+
+function scale_pg_count(prev_pgs, prev_pg_history, new_pg_history, new_pg_count)
+{
+    const old_pg_count = prev_pgs.length;
+    // Add all possibly intersecting PGs into the history of new PGs
+    if (!(new_pg_count % old_pg_count))
+    {
+        // New PG count is a multiple of the old PG count
+        const mul = (new_pg_count / old_pg_count);
+        for (let i = 0; i < new_pg_count; i++)
+        {
+            const old_i = Math.floor(new_pg_count / mul);
+            new_pg_history[i] = JSON.parse(JSON.stringify(prev_pg_history[1+old_i]));
+        }
+    }
+    else if (!(old_pg_count % new_pg_count))
+    {
+        // Old PG count is a multiple of the new PG count
+        const mul = (old_pg_count / new_pg_count);
+        for (let i = 0; i < new_pg_count; i++)
+        {
+            new_pg_history[i] = {
+                osd_sets: [],
+                all_peers: [],
+                epoch: 0,
+            };
+            for (let j = 0; j < mul; j++)
+            {
+                new_pg_history[i].osd_sets.push(prev_pgs[i*mul]);
+                const hist = prev_pg_history[1+i*mul+j];
+                if (hist && hist.osd_sets && hist.osd_sets.length)
+                {
+                    Array.prototype.push.apply(new_pg_history[i].osd_sets, hist.osd_sets);
+                }
+                if (hist && hist.all_peers && hist.all_peers.length)
+                {
+                    Array.prototype.push.apply(new_pg_history[i].all_peers, hist.all_peers);
+                }
+                if (hist && hist.epoch)
+                {
+                    new_pg_history[i].epoch = new_pg_history[i].epoch < hist.epoch ? hist.epoch : new_pg_history[i].epoch;
+                }
+            }
+        }
+    }
+    else
+    {
+        // Any PG may intersect with any PG after non-multiple PG count change
+        // So, merge ALL PGs history
+        let all_sets = {};
+        let all_peers = {};
+        let max_epoch = 0;
+        for (const pg of prev_pgs)
+        {
+            all_sets[pg.join(' ')] = pg;
+        }
+        for (const pg in prev_pg_history)
+        {
+            const hist = prev_pg_history[pg];
+            if (hist && hist.osd_sets)
+            {
+                for (const pg of hist.osd_sets)
+                {
+                    all_sets[pg.join(' ')] = pg;
+                }
+            }
+            if (hist && hist.all_peers)
+            {
+                for (const osd_num of hist.all_peers)
+                {
+                    all_peers[osd_num] = Number(osd_num);
+                }
+            }
+            if (hist && hist.epoch)
+            {
+                max_epoch = max_epoch < hist.epoch ? hist.epoch : max_epoch;
+            }
+        }
+        all_sets = Object.values(all_sets);
+        all_peers = Object.values(all_peers);
+        for (let i = 0; i < new_pg_count; i++)
+        {
+            new_pg_history[i] = { osd_sets: all_sets, all_peers, epoch: max_epoch };
+        }
+    }
+    // Mark history keys for removed PGs as removed
+    for (let i = new_pg_count; i < old_pg_count; i++)
+    {
+        new_pg_history[i] = null;
+    }
+    if (old_pg_count < new_pg_count)
+    {
+        for (let i = new_pg_count-1; i >= 0; i--)
+        {
+            prev_pgs[i] = prev_pgs[Math.floor(i/new_pg_count*old_pg_count)];
+        }
+    }
+    else if (old_pg_count > new_pg_count)
+    {
+        for (let i = 0; i < new_pg_count; i++)
+        {
+            prev_pgs[i] = prev_pgs[Math.round(i/new_pg_count*old_pg_count)];
+        }
+        prev_pgs.splice(new_pg_count, old_pg_count-new_pg_count);
+    }
+}

mon/afr.js

@@ -0,0 +1,159 @@
+// Functions to calculate Annualized Failure Rate of your cluster
+// if you know AFR of your drives, number of drives, expected rebalance time
+// and replication factor
+// License: VNPL-1.0 (see README.md for details)
+
+const { sprintf } = require('sprintf-js');
+
+module.exports = {
+    cluster_afr_fullmesh,
+    failure_rate_fullmesh,
+    cluster_afr,
+    print_cluster_afr,
+    c_n_k,
+};
+
+print_cluster_afr({ n_hosts: 4, n_drives: 6, afr_drive: 0.03, afr_host: 0.05, capacity: 4000, speed: 0.1, replicas: 2 });
+print_cluster_afr({ n_hosts: 4, n_drives: 3, afr_drive: 0.03, capacity: 4000, speed: 0.1, replicas: 2 });
+print_cluster_afr({ n_hosts: 4, n_drives: 3, afr_drive: 0.03, afr_host: 0.05, capacity: 4000, speed: 0.1, replicas: 2 });
+print_cluster_afr({ n_hosts: 4, n_drives: 3, afr_drive: 0.03, capacity: 4000, speed: 0.1, ec: [ 2, 1 ] });
+print_cluster_afr({ n_hosts: 4, n_drives: 3, afr_drive: 0.03, afr_host: 0.05, capacity: 4000, speed: 0.1, ec: [ 2, 1 ] });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, capacity: 8000, speed: 0.02, replicas: 2 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, afr_host: 0.05, capacity: 8000, speed: 0.02, replicas: 2 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, capacity: 8000, speed: 0.02, replicas: 3 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, afr_host: 0.05, capacity: 8000, speed: 0.02, replicas: 3 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, capacity: 8000, speed: 0.02, replicas: 3, pgs: 100 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, afr_host: 0.05, capacity: 8000, speed: 0.02, replicas: 3, pgs: 100 });
+print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, afr_host: 0.05, capacity: 8000, speed: 0.02, replicas: 3, pgs: 100, degraded_replacement: 1 });
+
+/******** "FULL MESH": ASSUME EACH OSD COMMUNICATES WITH ALL OTHER OSDS ********/
+
+// Estimate AFR of the cluster
+// n - number of drives
+// afr - annualized failure rate of a single drive
+// l - expected rebalance time in days after a single drive failure
+// k - replication factor / number of drives that must fail at the same time for the cluster to fail
+function cluster_afr_fullmesh(n, afr, l, k)
+{
+    return 1 - (1 - afr * failure_rate_fullmesh(n-(k-1), afr*l/365, k-1)) ** (n-(k-1));
+}
+
+// Probability of at least <f> failures in a cluster with <n> drives with AFR=<a>
+function failure_rate_fullmesh(n, a, f)
+{
+    if (f <= 0)
+    {
+        return (1-a)**n;
+    }
+    let p = 1;
+    for (let i = 0; i < f; i++)
+    {
+        p -= c_n_k(n, i) * (1-a)**(n-i) * a**i;
+    }
+    return p;
+}
+
+/******** PGS: EACH OSD ONLY COMMUNICATES WITH <pgs> OTHER OSDs ********/
+
+// <n> hosts of <m> drives of <capacity> GB, each able to backfill at <speed> GB/s,
+// <k> replicas, <pgs> unique peer PGs per OSD
+//
+// For each of n*m drives: P(drive fails in a year) * P(any of its peers fail in <l*365> next days).
+// More peers per OSD increase rebalance speed (more drives work together to resilver) if you
+// let them finish rebalance BEFORE replacing the failed drive.
+// At the same time, more peers per OSD increase probability of any of them to fail!
+//
+// Probability of all except one drives in a replica group to fail is (AFR^(k-1)).
+// So with <x> PGs it becomes ~ (x * (AFR*L/365)^(k-1)). Interesting but reasonable consequence
+// is that, with k=2, total failure rate doesn't depend on number of peers per OSD,
+// because it gets increased linearly by increased number of peers to fail
+// and decreased linearly by reduced rebalance time.
+function cluster_afr_pgs({ n_hosts, n_drives, afr_drive, capacity, speed, replicas, pgs = 1, degraded_replacement })
+{
+    pgs = Math.min(pgs, (n_hosts-1)*n_drives/(replicas-1));
+    const l = capacity/(degraded_replacement ? 1 : pgs)/speed/86400/365;
+    return 1 - (1 - afr_drive * (1-(1-(afr_drive*l)**(replicas-1))**pgs)) ** (n_hosts*n_drives);
+}
+
+function cluster_afr_pgs_ec({ n_hosts, n_drives, afr_drive, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, degraded_replacement })
+{
+    const ec_total = ec_data+ec_parity;
+    pgs = Math.min(pgs, (n_hosts-1)*n_drives/(ec_total-1));
+    const l = capacity/(degraded_replacement ? 1 : pgs)/speed/86400/365;
+    return 1 - (1 - afr_drive * (1-(1-failure_rate_fullmesh(ec_total-1, afr_drive*l, ec_parity))**pgs)) ** (n_hosts*n_drives);
+}
+
+// Same as above, but also take server failures into account
+function cluster_afr_pgs_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, replicas, pgs = 1, degraded_replacement })
+{
+    let otherhosts = Math.min(pgs, (n_hosts-1)/(replicas-1));
+    pgs = Math.min(pgs, (n_hosts-1)*n_drives/(replicas-1));
+    let pgh = Math.min(pgs*n_drives, (n_hosts-1)*n_drives/(replicas-1));
+    const ld = capacity/(degraded_replacement ? 1 : pgs)/speed/86400/365;
+    const lh = n_drives*capacity/pgs/speed/86400/365;
+    const p1 = ((afr_drive+afr_host*pgs/otherhosts)*lh);
+    const p2 = ((afr_drive+afr_host*pgs/otherhosts)*ld);
+    return 1 - ((1 - afr_host * (1-(1-p1**(replicas-1))**pgh)) ** n_hosts) *
+        ((1 - afr_drive * (1-(1-p2**(replicas-1))**pgs)) ** (n_hosts*n_drives));
+}
+
+function cluster_afr_pgs_ec_hosts({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, ec: [ ec_data, ec_parity ], pgs = 1, degraded_replacement })
+{
+    const ec_total = ec_data+ec_parity;
+    const otherhosts = Math.min(pgs, (n_hosts-1)/(ec_total-1));
+    pgs = Math.min(pgs, (n_hosts-1)*n_drives/(ec_total-1));
+    const pgh = Math.min(pgs*n_drives, (n_hosts-1)*n_drives/(ec_total-1));
+    const ld = capacity/(degraded_replacement ? 1 : pgs)/speed/86400/365;
+    const lh = n_drives*capacity/pgs/speed/86400/365;
+    const p1 = ((afr_drive+afr_host*pgs/otherhosts)*lh);
+    const p2 = ((afr_drive+afr_host*pgs/otherhosts)*ld);
+    return 1 - ((1 - afr_host * (1-(1-failure_rate_fullmesh(ec_total-1, p1, ec_parity))**pgh)) ** n_hosts) *
+        ((1 - afr_drive * (1-(1-failure_rate_fullmesh(ec_total-1, p2, ec_parity))**pgs)) ** (n_hosts*n_drives));
+}
+
+// Wrapper for 4 above functions
+function cluster_afr(config)
+{
+    if (config.ec && config.afr_host)
+    {
+        return cluster_afr_pgs_ec_hosts(config);
+    }
+    else if (config.ec)
+    {
+        return cluster_afr_pgs_ec(config);
+    }
+    else if (config.afr_host)
+    {
+        return cluster_afr_pgs_hosts(config);
+    }
+    else
+    {
+        return cluster_afr_pgs(config);
+    }
+}
+
+function print_cluster_afr(config)
+{
+    console.log(
+        `${config.n_hosts} nodes with ${config.n_drives} ${sprintf("%.1f", config.capacity/1000)}TB drives`+
+        `, capable to backfill at ${sprintf("%.1f", config.speed*1000)} MB/s, drive AFR ${sprintf("%.1f", config.afr_drive*100)}%`+
+        (config.afr_host ? `, host AFR ${sprintf("%.1f", config.afr_host*100)}%` : '')+
+        (config.ec ? `, EC ${config.ec[0]}+${config.ec[1]}` : `, ${config.replicas} replicas`)+
+        `, ${config.pgs||1} PG per OSD`+
+        (config.degraded_replacement ? `\n...and you don't let the rebalance finish before replacing drives` : '')
+    );
+    console.log('-> '+sprintf("%.7f%%", 100*cluster_afr(config))+'\n');
+}
+
+/******** UTILITY ********/
+
+// Combination count
+function c_n_k(n, k)
+{
+    let r = 1;
+    for (let i = 0; i < k; i++)
+    {
+        r *= (n-i) / (i+1);
+    }
+    return r;
+}

mon/lp-optimizer.js

@@ -0,0 +1,688 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+// Data distribution optimizer using linear programming (lp_solve)
+
+const child_process = require('child_process');
+
+const NO_OSD = 'Z';
+
+async function lp_solve(text)
+{
+    const cp = child_process.spawn('lp_solve');
+    let stdout = '', stderr = '', finish_cb;
+    cp.stdout.on('data', buf => stdout += buf.toString());
+    cp.stderr.on('data', buf => stderr += buf.toString());
+    cp.on('exit', () => finish_cb && finish_cb());
+    cp.stdin.write(text);
+    cp.stdin.end();
+    if (cp.exitCode == null)
+    {
+        await new Promise(ok => finish_cb = ok);
+    }
+    if (!stdout.trim())
+    {
+        return null;
+    }
+    let score = 0;
+    let vars = {};
+    for (const line of stdout.split(/\n/))
+    {
+        let m = /^(^Value of objective function: (-?[\d\.]+)|Actual values of the variables:)\s*$/.exec(line);
+        if (m)
+        {
+            if (m[2])
+            {
+                score = m[2];
+            }
+            continue;
+        }
+        else if (/This problem is (infeasible|unbounded)/.exec(line))
+        {
+            return null;
+        }
+        let [ k, v ] = line.trim().split(/\s+/, 2);
+        if (v)
+        {
+            vars[k] = v;
+        }
+    }
+    return { score, vars };
+}
+
+async function optimize_initial({ osd_tree, pg_count, pg_size = 3, pg_minsize = 2, max_combinations = 10000, parity_space = 1 })
+{
+    if (!pg_count || !osd_tree)
+    {
+        return null;
+    }
+    const all_weights = Object.assign({}, ...Object.values(osd_tree));
+    const total_weight = Object.values(all_weights).reduce((a, c) => Number(a) + Number(c), 0);
+    const all_pgs = Object.values(random_combinations(osd_tree, pg_size, max_combinations));
+    const pg_per_osd = {};
+    for (const pg of all_pgs)
+    {
+        for (let i = 0; i < pg.length; i++)
+        {
+            const osd = pg[i];
+            pg_per_osd[osd] = pg_per_osd[osd] || [];
+            pg_per_osd[osd].push((i >= pg_minsize ? parity_space+'*' : '')+"pg_"+pg.join("_"));
+        }
+    }
+    const pg_effsize = Math.min(pg_minsize, Object.keys(osd_tree).length)
+        + Math.max(0, Math.min(pg_size, Object.keys(osd_tree).length) - pg_minsize) * parity_space;
+    let lp = '';
+    lp += "max: "+all_pgs.map(pg => 'pg_'+pg.join('_')).join(' + ')+";\n";
+    for (const osd in pg_per_osd)
+    {
+        if (osd !== NO_OSD)
+        {
+            let osd_pg_count = all_weights[osd]/total_weight*pg_effsize*pg_count;
+            lp += pg_per_osd[osd].join(' + ')+' <= '+osd_pg_count+';\n';
+        }
+    }
+    for (const pg of all_pgs)
+    {
+        lp += 'pg_'+pg.join('_')+" >= 0;\n";
+    }
+    lp += "sec "+all_pgs.map(pg => 'pg_'+pg.join('_')).join(', ')+";\n";
+    const lp_result = await lp_solve(lp);
+    if (!lp_result)
+    {
+        console.log(lp);
+        throw new Error('Problem is infeasible or unbounded - is it a bug?');
+    }
+    const int_pgs = make_int_pgs(lp_result.vars, pg_count);
+    const eff = pg_list_space_efficiency(int_pgs, all_weights, pg_minsize, parity_space);
+    const res = {
+        score: lp_result.score,
+        weights: lp_result.vars,
+        int_pgs,
+        space: eff * pg_effsize,
+        total_space: total_weight,
+    };
+    return res;
+}
+
+function make_int_pgs(weights, pg_count)
+{
+    const total_weight = Object.values(weights).reduce((a, c) => Number(a) + Number(c), 0);
+    let int_pgs = [];
+    let pg_left = pg_count;
+    let weight_left = total_weight;
+    for (const pg_name in weights)
+    {
+        let n = Math.round(weights[pg_name] / weight_left * pg_left);
+        for (let i = 0; i < n; i++)
+        {
+            int_pgs.push(pg_name.substr(3).split('_'));
+        }
+        weight_left -= weights[pg_name];
+        pg_left -= n;
+    }
+    return int_pgs;
+}
+
+function calc_intersect_weights(pg_size, pg_count, prev_weights, all_pgs)
+{
+    const move_weights = {};
+    if ((1 << pg_size) < pg_count)
+    {
+        const intersect = {};
+        for (const pg_name in prev_weights)
+        {
+            const pg = pg_name.substr(3).split(/_/);
+            for (let omit = 1; omit < (1 << pg_size); omit++)
+            {
+                let pg_omit = [ ...pg ];
+                let intersect_count = pg_size;
+                for (let i = 0; i < pg_size; i++)
+                {
+                    if (omit & (1 << i))
+                    {
+                        pg_omit[i] = '';
+                        intersect_count--;
+                    }
+                }
+                pg_omit = pg_omit.join(':');
+                intersect[pg_omit] = Math.max(intersect[pg_omit] || 0, intersect_count);
+            }
+        }
+        for (const pg of all_pgs)
+        {
+            let max_int = 0;
+            for (let omit = 1; omit < (1 << pg_size); omit++)
+            {
+                let pg_omit = [ ...pg ];
+                for (let i = 0; i < pg_size; i++)
+                {
+                    if (omit & (1 << i))
+                    {
+                        pg_omit[i] = '';
+                    }
+                }
+                pg_omit = pg_omit.join(':');
+                max_int = Math.max(max_int, intersect[pg_omit] || 0);
+            }
+            move_weights['pg_'+pg.join('_')] = pg_size-max_int;
+        }
+    }
+    else
+    {
+        const prev_pg_hashed = Object.keys(prev_weights).map(pg_name => pg_name.substr(3).split(/_/).reduce((a, c) => { a[c] = 1; return a; }, {}));
+        for (const pg of all_pgs)
+        {
+            if (!prev_weights['pg_'+pg.join('_')])
+            {
+                let max_int = 0;
+                for (const prev_hash in prev_pg_hashed)
+                {
+                    const intersect_count = pg.reduce((a, osd) => a + (prev_hash[osd] ? 1 : 0), 0);
+                    if (max_int < intersect_count)
+                    {
+                        max_int = intersect_count;
+                        if (max_int >= pg_size)
+                        {
+                            break;
+                        }
+                    }
+                }
+                move_weights['pg_'+pg.join('_')] = pg_size-max_int;
+            }
+        }
+    }
+    return move_weights;
+}
+
+function add_valid_previous(osd_tree, prev_weights, all_pgs)
+{
+    // Add previous combinations that are still valid
+    const hosts = Object.keys(osd_tree).sort();
+    const host_per_osd = {};
+    for (const host in osd_tree)
+    {
+        for (const osd in osd_tree[host])
+        {
+            host_per_osd[osd] = host;
+        }
+    }
+    skip_pg: for (const pg_name in prev_weights)
+    {
+        const seen_hosts = {};
+        const pg = pg_name.substr(3).split(/_/);
+        for (const osd of pg)
+        {
+            if (!host_per_osd[osd] || seen_hosts[host_per_osd[osd]])
+            {
+                continue skip_pg;
+            }
+            seen_hosts[host_per_osd[osd]] = true;
+        }
+        if (!all_pgs[pg_name])
+        {
+            all_pgs[pg_name] = pg;
+        }
+    }
+}
+
+// Try to minimize data movement
+async function optimize_change({ prev_pgs: prev_int_pgs, osd_tree, pg_size = 3, pg_minsize = 2, max_combinations = 10000, parity_space = 1 })
+{
+    if (!osd_tree)
+    {
+        return null;
+    }
+    const pg_effsize = Math.min(pg_minsize, Object.keys(osd_tree).length)
+        + Math.max(0, Math.min(pg_size, Object.keys(osd_tree).length) - pg_minsize) * parity_space;
+    const pg_count = prev_int_pgs.length;
+    const prev_weights = {};
+    const prev_pg_per_osd = {};
+    for (const pg of prev_int_pgs)
+    {
+        const pg_name = 'pg_'+pg.join('_');
+        prev_weights[pg_name] = (prev_weights[pg_name]||0) + 1;
+        for (let i = 0; i < pg.length; i++)
+        {
+            const osd = pg[i];
+            prev_pg_per_osd[osd] = prev_pg_per_osd[osd] || [];
+            prev_pg_per_osd[osd].push([ pg_name, (i >= pg_minsize ? parity_space : 1) ]);
+        }
+    }
+    // Get all combinations
+    let all_pgs = random_combinations(osd_tree, pg_size, max_combinations);
+    add_valid_previous(osd_tree, prev_weights, all_pgs);
+    all_pgs = Object.values(all_pgs);
+    const pg_per_osd = {};
+    for (const pg of all_pgs)
+    {
+        const pg_name = 'pg_'+pg.join('_');
+        for (let i = 0; i < pg.length; i++)
+        {
+            const osd = pg[i];
+            pg_per_osd[osd] = pg_per_osd[osd] || [];
+            pg_per_osd[osd].push([ pg_name, (i >= pg_minsize ? parity_space : 1) ]);
+        }
+    }
+    // Penalize PGs based on their similarity to old PGs
+    const move_weights = calc_intersect_weights(pg_size, pg_count, prev_weights, all_pgs);
+    // Calculate total weight - old PG weights
+    const all_pg_names = all_pgs.map(pg => 'pg_'+pg.join('_'));
+    const all_pgs_hash = all_pg_names.reduce((a, c) => { a[c] = true; return a; }, {});
+    const all_weights = Object.assign({}, ...Object.values(osd_tree));
+    const total_weight = Object.values(all_weights).reduce((a, c) => Number(a) + Number(c), 0);
+    // Generate the LP problem
+    let lp = '';
+    lp += 'max: '+all_pg_names.map(pg_name => (
+        prev_weights[pg_name] ? `${pg_size+1}*add_${pg_name} - ${pg_size+1}*del_${pg_name}` : `${pg_size+1-move_weights[pg_name]}*${pg_name}`
+    )).join(' + ')+';\n';
+    for (const osd in pg_per_osd)
+    {
+        if (osd !== NO_OSD)
+        {
+            const osd_sum = (pg_per_osd[osd]||[]).map(([ pg_name, space ]) => (
+                prev_weights[pg_name] ? `${space} * add_${pg_name} - ${space} * del_${pg_name}` : `${space} * ${pg_name}`
+            )).join(' + ');
+            const rm_osd_pg_count = (prev_pg_per_osd[osd]||[])
+                .reduce((a, [ old_pg_name, space ]) => (a + (all_pgs_hash[old_pg_name] ? space : 0)), 0);
+            const osd_pg_count = all_weights[osd]*pg_effsize/total_weight*pg_count - rm_osd_pg_count;
+            lp += osd_sum + ' <= ' + osd_pg_count + ';\n';
+        }
+    }
+    let pg_vars = [];
+    for (const pg_name of all_pg_names)
+    {
+        if (prev_weights[pg_name])
+        {
+            pg_vars.push(`add_${pg_name}`, `del_${pg_name}`);
+            // Can't add or remove less than zero
+            lp += `add_${pg_name} >= 0;\n`;
+            lp += `del_${pg_name} >= 0;\n`;
+            // Can't remove more than the PG already has
+            lp += `add_${pg_name} - del_${pg_name} >= -${prev_weights[pg_name]};\n`;
+        }
+        else
+        {
+            pg_vars.push(pg_name);
+            lp += `${pg_name} >= 0;\n`;
+        }
+    }
+    lp += 'sec '+pg_vars.join(', ')+';\n';
+    // Solve it
+    const lp_result = await lp_solve(lp);
+    if (!lp_result)
+    {
+        console.log(lp);
+        throw new Error('Problem is infeasible or unbounded - is it a bug?');
+    }
+    // Generate the new distribution
+    const weights = { ...prev_weights };
+    for (const k in prev_weights)
+    {
+        if (!all_pgs_hash[k])
+        {
+            delete weights[k];
+        }
+    }
+    for (const k in lp_result.vars)
+    {
+        if (k.substr(0, 4) === 'add_')
+        {
+            weights[k.substr(4)] = (weights[k.substr(4)] || 0) + Number(lp_result.vars[k]);
+        }
+        else if (k.substr(0, 4) === 'del_')
+        {
+            weights[k.substr(4)] = (weights[k.substr(4)] || 0) - Number(lp_result.vars[k]);
+        }
+        else if (k.substr(0, 3) === 'pg_')
+        {
+            weights[k] = Number(lp_result.vars[k]);
+        }
+    }
+    for (const k in weights)
+    {
+        if (!weights[k])
+        {
+            delete weights[k];
+        }
+    }
+    const int_pgs = make_int_pgs(weights, pg_count);
+    // Align them with most similar previous PGs
+    const new_pgs = align_pgs(prev_int_pgs, int_pgs);
+    let differs = 0, osd_differs = 0;
+    for (let i = 0; i < pg_count; i++)
+    {
+        if (new_pgs[i].join('_') != prev_int_pgs[i].join('_'))
+        {
+            differs++;
+        }
+        for (let j = 0; j < pg_size; j++)
+        {
+            if (new_pgs[i][j] != prev_int_pgs[i][j])
+            {
+                osd_differs++;
+            }
+        }
+    }
+    return {
+        prev_pgs: prev_int_pgs,
+        score: lp_result.score,
+        weights,
+        int_pgs: new_pgs,
+        differs,
+        osd_differs,
+        space: pg_effsize * pg_list_space_efficiency(new_pgs, all_weights, pg_minsize, parity_space),
+        total_space: total_weight,
+    };
+}
+
+function print_change_stats(retval, detailed)
+{
+    const new_pgs = retval.int_pgs;
+    const prev_int_pgs = retval.prev_pgs;
+    if (prev_int_pgs)
+    {
+        if (detailed)
+        {
+            for (let i = 0; i < new_pgs.length; i++)
+            {
+                if (new_pgs[i].join('_') != prev_int_pgs[i].join('_'))
+                {
+                    console.log("pg "+i+": "+prev_int_pgs[i].join(' ')+" -> "+new_pgs[i].join(' '));
+                }
+            }
+        }
+        console.log(
+            "Data movement: "+retval.differs+" pgs, "+
+            retval.osd_differs+" pg*osds = "+Math.round(retval.osd_differs / prev_int_pgs.length / 3 * 10000)/100+" %"
+        );
+    }
+    console.log(
+        "Total space (raw): "+Math.round(retval.space*100)/100+" TB, space efficiency: "+
+        Math.round(retval.space/(retval.total_space||1)*10000)/100+" %"
+    );
+}
+
+function align_pgs(prev_int_pgs, int_pgs)
+{
+    const aligned_pgs = [];
+    put_aligned_pgs(aligned_pgs, int_pgs, prev_int_pgs, (pg) => [ pg.join(':') ]);
+    put_aligned_pgs(aligned_pgs, int_pgs, prev_int_pgs, (pg) => [ pg[0]+'::'+pg[2], ':'+pg[1]+':'+pg[2], pg[0]+':'+pg[1]+':' ]);
+    put_aligned_pgs(aligned_pgs, int_pgs, prev_int_pgs, (pg) => [ pg[0]+'::', ':'+pg[1]+':', '::'+pg[2] ]);
+    const free_slots = prev_int_pgs.map((pg, i) => !aligned_pgs[i] ? i : null).filter(i => i != null);
+    for (const pg of int_pgs)
+    {
+        if (!free_slots.length)
+        {
+            throw new Error("Can't place unaligned PG");
+        }
+        aligned_pgs[free_slots.shift()] = pg;
+    }
+    return aligned_pgs;
+}
+
+function put_aligned_pgs(aligned_pgs, int_pgs, prev_int_pgs, keygen)
+{
+    let prev_indexes = {};
+    for (let i = 0; i < prev_int_pgs.length; i++)
+    {
+        for (let k of keygen(prev_int_pgs[i]))
+        {
+            prev_indexes[k] = prev_indexes[k] || [];
+            prev_indexes[k].push(i);
+        }
+    }
+    PG: for (let i = int_pgs.length-1; i >= 0; i--)
+    {
+        let pg = int_pgs[i];
+        let keys = keygen(int_pgs[i]);
+        for (let k of keys)
+        {
+            while (prev_indexes[k] && prev_indexes[k].length)
+            {
+                let idx = prev_indexes[k].shift();
+                if (!aligned_pgs[idx])
+                {
+                    aligned_pgs[idx] = pg;
+                    int_pgs.splice(i, 1);
+                    continue PG;
+                }
+            }
+        }
+    }
+}
+
+// Convert multi-level osd_tree = { level: number|string, id?: string, size?: number, children?: osd_tree }[]
+// levels = { string: number }
+// to a two-level osd_tree suitable for all_combinations()
+function flatten_tree(osd_tree, levels, failure_domain_level, osd_level, domains = {}, i = { i: 1 })
+{
+    osd_level = levels[osd_level] || osd_level;
+    failure_domain_level = levels[failure_domain_level] || failure_domain_level;
+    for (const node of osd_tree)
+    {
+        if ((levels[node.level] || node.level) < failure_domain_level)
+        {
+            flatten_tree(node.children||[], levels, failure_domain_level, osd_level, domains, i);
+        }
+        else
+        {
+            domains['dom'+(i.i++)] = extract_osds([ node ], levels, osd_level);
+        }
+    }
+    return domains;
+}
+
+function extract_osds(osd_tree, levels, osd_level, osds = {})
+{
+    for (const node of osd_tree)
+    {
+        if ((levels[node.level] || node.level) >= osd_level)
+        {
+            osds[node.id] = node.size;
+        }
+        else
+        {
+            extract_osds(node.children||[], levels, osd_level, osds);
+        }
+    }
+    return osds;
+}
+
+function random_combinations(osd_tree, pg_size, count)
+{
+    let seed = 0x5f020e43;
+    let rng = () =>
+    {
+        seed ^= seed << 13;
+        seed ^= seed >> 17;
+        seed ^= seed << 5;
+        return seed + 2147483648;
+    };
+    const hosts = Object.keys(osd_tree).sort();
+    const osds = Object.keys(osd_tree).reduce((a, c) => { a[c] = Object.keys(osd_tree[c]).sort(); return a; }, {});
+    const r = {};
+    // Generate random combinations including each OSD at least once
+    for (let h = 0; h < hosts.length; h++)
+    {
+        for (let o = 0; o < osds[hosts[h]].length; o++)
+        {
+            const pg = [ osds[hosts[h]][o] ];
+            const cur_hosts = [ ...hosts ];
+            cur_hosts.splice(h, 1);
+            for (let i = 1; i < pg_size && i < hosts.length; i++)
+            {
+                const next_host = rng() % cur_hosts.length;
+                const next_osd = rng() % osds[cur_hosts[next_host]].length;
+                pg.push(osds[cur_hosts[next_host]][next_osd]);
+                cur_hosts.splice(next_host, 1);
+            }
+            while (pg.length < pg_size)
+            {
+                pg.push(NO_OSD);
+            }
+            r['pg_'+pg.join('_')] = pg;
+        }
+    }
+    // Generate purely random combinations
+    restart: while (count > 0)
+    {
+        let host_idx = [];
+        for (let i = 0; i < pg_size && i < hosts.length; i++)
+        {
+            let start = i > 0 ? host_idx[i-1]+1 : 0;
+            if (start >= hosts.length)
+            {
+                continue restart;
+            }
+            host_idx[i] = start + rng() % (hosts.length-start);
+        }
+        let pg = host_idx.map(h => osds[hosts[h]][rng() % osds[hosts[h]].length]);
+        while (pg.length < pg_size)
+        {
+            pg.push(NO_OSD);
+        }
+        r['pg_'+pg.join('_')] = pg;
+        count--;
+    }
+    return r;
+}
+
+// Super-stupid algorithm. Given the current OSD tree, generate all possible OSD combinations
+// osd_tree = { failure_domain1: { osd1: size1, ... }, ... }
+// ordered = return combinations without duplicates having different order
+function all_combinations(osd_tree, pg_size, ordered, count)
+{
+    const hosts = Object.keys(osd_tree).sort();
+    const osds = Object.keys(osd_tree).reduce((a, c) => { a[c] = Object.keys(osd_tree[c]).sort(); return a; }, {});
+    while (hosts.length < pg_size)
+    {
+        osds[NO_OSD] = [ NO_OSD ];
+        hosts.push(NO_OSD);
+    }
+    let host_idx = [];
+    let osd_idx = [];
+    for (let i = 0; i < pg_size; i++)
+    {
+        host_idx.push(i);
+        osd_idx.push(0);
+    }
+    const r = [];
+    while (!count || count < 0 || r.length < count)
+    {
+        r.push(host_idx.map((hi, i) => osds[hosts[hi]][osd_idx[i]]));
+        let inc = pg_size-1;
+        while (inc >= 0)
+        {
+            osd_idx[inc]++;
+            if (osd_idx[inc] >= osds[hosts[host_idx[inc]]].length)
+            {
+                osd_idx[inc] = 0;
+                inc--;
+            }
+            else
+            {
+                break;
+            }
+        }
+        if (inc < 0)
+        {
+            // no osds left in the current host combination, select the next one
+            inc = pg_size-1;
+            same_again: while (inc >= 0)
+            {
+                host_idx[inc]++;
+                for (let prev_host = 0; prev_host < inc; prev_host++)
+                {
+                    if (host_idx[prev_host] == host_idx[inc])
+                    {
+                        continue same_again;
+                    }
+                }
+                if (host_idx[inc] < (ordered ? hosts.length-(pg_size-1-inc) : hosts.length))
+                {
+                    while ((++inc) < pg_size)
+                    {
+                        host_idx[inc] = (ordered ? host_idx[inc-1]+1 : 0);
+                    }
+                    break;
+                }
+                else
+                {
+                    inc--;
+                }
+            }
+            if (inc < 0)
+            {
+                break;
+            }
+        }
+    }
+    return r;
+}
+
+function pg_weights_space_efficiency(weights, pg_count, osd_sizes)
+{
+    const per_osd = {};
+    for (const pg_name in weights)
+    {
+        for (const osd of pg_name.substr(3).split(/_/))
+        {
+            per_osd[osd] = (per_osd[osd]||0) + weights[pg_name];
+        }
+    }
+    return pg_per_osd_space_efficiency(per_osd, pg_count, osd_sizes);
+}
+
+function pg_list_space_efficiency(pgs, osd_sizes, pg_minsize, parity_space)
+{
+    const per_osd = {};
+    for (const pg of pgs)
+    {
+        for (let i = 0; i < pg.length; i++)
+        {
+            const osd = pg[i];
+            per_osd[osd] = (per_osd[osd]||0) + (i >= pg_minsize ? (parity_space||1) : 1);
+        }
+    }
+    return pg_per_osd_space_efficiency(per_osd, pgs.length, osd_sizes);
+}
+
+function pg_per_osd_space_efficiency(per_osd, pg_count, osd_sizes)
+{
+    // each PG gets randomly selected in 1/N cases
+    // & there are x PGs per OSD
+    // => an OSD is selected in x/N cases
+    // => total space * x/N <= OSD size
+    // => total space <= OSD size * N/x
+    let space;
+    for (let osd in per_osd)
+    {
+        if (osd in osd_sizes)
+        {
+            const space_estimate = osd_sizes[osd] * pg_count / per_osd[osd];
+            if (space == null || space > space_estimate)
+            {
+                space = space_estimate;
+            }
+        }
+    }
+    return space == null ? 0 : space;
+}
+
+module.exports = {
+    NO_OSD,
+
+    optimize_initial,
+    optimize_change,
+    print_change_stats,
+    pg_weights_space_efficiency,
+    pg_list_space_efficiency,
+    pg_per_osd_space_efficiency,
+    flatten_tree,
+
+    lp_solve,
+    make_int_pgs,
+    align_pgs,
+    random_combinations,
+    all_combinations,
+};

mon/make-units.sh

@@ -0,0 +1,136 @@
+#!/bin/bash
+# Example startup script generator
+# Of course this isn't a production solution yet, this is just for tests
+# Copyright (c) Vitaliy Filippov, 2019+
+# License: MIT
+
+IP=`ip -json a s | jq -r '.[].addr_info[] | select(.broadcast == "10.115.0.255") | .local'`
+
+[ "$IP" != "" ] || exit 1
+
+useradd vitastor
+chmod 755 /root
+
+BASE=${IP/*./}
+BASE=$(((BASE-10)*12))
+
+cat >/etc/systemd/system/vitastor.target <<EOF
+[Unit]
+Description=vitastor target
+[Install]
+WantedBy=multi-user.target
+EOF
+
+i=1
+for DEV in `ls /dev/disk/by-id/ | grep ata-INTEL_SSDSC2KB`; do
+    dd if=/dev/zero of=/dev/disk/by-id/$DEV bs=1048576 count=$(((427814912+1048575)/1048576+2))
+    dd if=/dev/zero of=/dev/disk/by-id/$DEV bs=1048576 count=$(((427814912+1048575)/1048576+2)) seek=$((1920377991168/1048576))
+cat >/etc/systemd/system/vitastor-osd$((BASE+i)).service <<EOF
+[Unit]
+Description=Vitastor object storage daemon osd.$((BASE+i))
+After=network-online.target local-fs.target time-sync.target
+Wants=network-online.target local-fs.target time-sync.target
+PartOf=vitastor.target
+
+[Service]
+LimitNOFILE=1048576
+LimitNPROC=1048576
+LimitMEMLOCK=infinity
+ExecStart=/root/vitastor/osd \\
+    --etcd_address $IP:2379/v3 \\
+    --bind_address $IP \\
+    --osd_num $((BASE+i)) \\
+    --disable_data_fsync 1 \\
+    --disable_device_lock 1 \\
+    --immediate_commit all \\
+    --flusher_count 8 \\
+    --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096 \\
+    --journal_no_same_sector_overwrites true \\
+    --journal_sector_buffer_count 1024 \\
+    --journal_offset 0 \\
+    --meta_offset 16777216 \\
+    --data_offset 427814912 \\
+    --data_size $((1920377991168-427814912)) \\
+    --data_device /dev/disk/by-id/$DEV
+WorkingDirectory=/root/vitastor
+ExecStartPre=+chown vitastor:vitastor /dev/disk/by-id/$DEV
+User=vitastor
+PrivateTmp=false
+TasksMax=infinity
+Restart=always
+StartLimitInterval=0
+StartLimitIntervalSec=0
+RestartSec=10
+
+[Install]
+WantedBy=vitastor.target
+EOF
+    systemctl enable vitastor-osd$((BASE+i))
+    i=$((i+1))
+cat >/etc/systemd/system/vitastor-osd$((BASE+i)).service <<EOF
+[Unit]
+Description=Vitastor object storage daemon osd.$((BASE+i))
+After=network-online.target local-fs.target time-sync.target
+Wants=network-online.target local-fs.target time-sync.target
+PartOf=vitastor.target
+
+[Service]
+LimitNOFILE=1048576
+LimitNPROC=1048576
+LimitMEMLOCK=infinity
+ExecStart=/root/vitastor/osd \\
+    --etcd_address $IP:2379/v3 \\
+    --bind_address $IP \\
+    --osd_num $((BASE+i)) \\
+    --disable_data_fsync 1 \\
+    --immediate_commit all \\
+    --flusher_count 8 \\
+    --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096 \\
+    --journal_no_same_sector_overwrites true \\
+    --journal_sector_buffer_count 1024 \\
+    --journal_offset 1920377991168 \\
+    --meta_offset $((1920377991168+16777216)) \\
+    --data_offset $((1920377991168+427814912)) \\
+    --data_size $((1920377991168-427814912)) \\
+    --data_device /dev/disk/by-id/$DEV
+WorkingDirectory=/root/vitastor
+ExecStartPre=+chown vitastor:vitastor /dev/disk/by-id/$DEV
+User=vitastor
+PrivateTmp=false
+TasksMax=infinity
+Restart=always
+StartLimitInterval=0
+StartLimitIntervalSec=0
+RestartSec=10
+
+[Install]
+WantedBy=vitastor.target
+EOF
+    systemctl enable vitastor-osd$((BASE+i))
+    i=$((i+1))
+done
+
+exit
+
+node mon-main.js --etcd_url 'http://10.115.0.10:2379,http://10.115.0.11:2379,http://10.115.0.12:2379,http://10.115.0.13:2379' --etcd_prefix '/vitastor' --etcd_start_timeout 5
+
+podman run -d --network host --restart always -v /var/lib/etcd0.etcd:/etcd0.etcd --name etcd quay.io/coreos/etcd:v3.4.13 etcd -name etcd0 \
+    -advertise-client-urls http://10.115.0.10:2379 -listen-client-urls http://10.115.0.10:2379 \
+    -initial-advertise-peer-urls http://10.115.0.10:2380 -listen-peer-urls http://10.115.0.10:2380 \
+    -initial-cluster-token vitastor-etcd-1 -initial-cluster etcd0=http://10.115.0.10:2380,etcd1=http://10.115.0.11:2380,etcd2=http://10.115.0.12:2380,etcd3=http://10.115.0.13:2380 \
+    -initial-cluster-state new --max-txn-ops=100000 --auto-compaction-retention=10 --auto-compaction-mode=revision
+
+etcdctl --endpoints http://10.115.0.10:2379 put /vitastor/config/global '{"immediate_commit":"all"}'
+
+etcdctl --endpoints http://10.115.0.10:2379 put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":48,"failure_domain":"host"}}'
+
+#let pgs = {};
+#for (let n = 0; n < 48; n++) { let i = n/2 | 0; pgs[1+n] = { osd_set: [ (1+i%12+(i/12 | 0)*24), (1+12+i%12+(i/12 | 0)*24) ], primary: (1+(n%2)*12+i%12+(i/12 | 0)*24) }; };
+#console.log(JSON.stringify({ items: { 1: pgs } }));
+#etcdctl --endpoints http://10.115.0.10:2379 put /vitastor/config/pgs ...
+
+#    --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096 \\
+#    --data_offset 427814912 \\
+
+#    --disk_alignment 4096 --journal_block_size 512 --meta_block_size 512 \\
+#    --data_offset 433434624 \\

mon/mon-main.js

@@ -0,0 +1,25 @@
+#!/usr/bin/node
+
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+const Mon = require('./mon.js');
+
+const options = {};
+
+for (let i = 2; i < process.argv.length; i++)
+{
+    if (process.argv[i].substr(0, 2) == '--')
+    {
+        options[process.argv[i].substr(2)] = process.argv[i+1];
+        i++;
+    }
+}
+
+if (!options.etcd_url)
+{
+    console.error('USAGE: '+process.argv[0]+' '+process.argv[1]+' --etcd_url "http://127.0.0.1:2379,..." --etcd_prefix "/vitastor" --etcd_start_timeout 5 [--verbose 1]');
+    process.exit();
+}
+
+new Mon(options).start().catch(e => { console.error(e); process.exit(); });

mon/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "vitastor-mon",
+  "version": "1.0.0",
+  "description": "Vitastor SDS monitor service",
+  "main": "mon-main.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "Vitaliy Filippov",
+  "license": "UNLICENSED",
+  "dependencies": {
+    "sprintf-js": "^1.1.2",
+    "ws": "^7.2.5"
+  }
+}

mon/simple-offsets.js

@@ -0,0 +1,56 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: MIT
+
+// Simple tool to calculate journal and metadata offsets for a single device
+// Will be replaced by smarter tools in the future
+
+const child_process = require('child_process');
+
+async function run()
+{
+    const options = {
+        object_size: 128*1024,
+        bitmap_granularity: 4096,
+        journal_size: 16*1024*1024,
+        device_block_size: 4096,
+        journal_offset: 0,
+        device_size: 0,
+    };
+    for (let i = 2; i < process.argv.length; i++)
+    {
+        if (process.argv[i].substr(0, 2) == '--')
+        {
+            options[process.argv[i].substr(2)] = process.argv[i+1];
+            i++;
+        }
+    }
+    const device_size = Number(options.device_size || await system("blockdev --getsize64 "+options.device));
+    if (!device_size)
+    {
+        process.stderr.write('Failed to get device size\n');
+        process.exit(1);
+    }
+    options.journal_offset = Math.ceil(options.journal_offset/options.device_block_size)*options.device_block_size;
+    const meta_offset = options.journal_offset + Math.ceil(options.journal_size/options.device_block_size)*options.device_block_size;
+    const entries_per_block = Math.floor(options.device_block_size / (24 + options.object_size/options.bitmap_granularity/8));
+    const object_count = Math.floor((device_size-meta_offset)/options.object_size);
+    const meta_size = Math.ceil(object_count / entries_per_block) * options.device_block_size;
+    const data_offset = meta_offset + meta_size;
+    const meta_size_fmt = (meta_size > 1024*1024*1024 ? Math.round(meta_size/1024/1024/1024*100)/100+" GB"
+        : Math.round(meta_size/1024/1024*100)/100+" MB");
+    process.stdout.write(
+        `Metadata size: ${meta_size_fmt}\n`+
+        `Options for the OSD:\n`+
+        `    --journal_offset ${options.journal_offset}\n`+
+        `    --meta_offset ${meta_offset}\n`+
+        `    --data_offset ${data_offset}\n`+
+        (options.device_size ? `    --data_size ${device_size-data_offset}\n` : '')
+    );
+}
+
+function system(cmd)
+{
+    return new Promise((ok, no) => child_process.exec(cmd, { maxBuffer: 64*1024*1024 }, (err, stdout, stderr) => (err ? no(err) : ok(stdout))));
+}
+
+run().catch(console.error);

mon/stable-stringify.js

@@ -0,0 +1,78 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: MIT
+
+function stableStringify(obj, opts)
+{
+    if (!opts)
+        opts = {};
+    if (typeof opts === 'function')
+        opts = { cmp: opts };
+    let space = opts.space || '';
+    if (typeof space === 'number')
+        space = Array(space+1).join(' ');
+    const cycles = (typeof opts.cycles === 'boolean') ? opts.cycles : false;
+    const cmp = opts.cmp && (function (f)
+    {
+        return function (node)
+        {
+            return function (a, b)
+            {
+                let aobj = { key: a, value: node[a] };
+                let bobj = { key: b, value: node[b] };
+                return f(aobj, bobj);
+            };
+        };
+    })(opts.cmp);
+    const seen = new Map();
+    return (function stringify (parent, key, node, level)
+    {
+        const indent = space ? ('\n' + new Array(level + 1).join(space)) : '';
+        const colonSeparator = space ? ': ' : ':';
+        if (node === undefined)
+        {
+            return;
+        }
+        if (typeof node !== 'object' || node === null)
+        {
+            return JSON.stringify(node);
+        }
+        if (node instanceof Array)
+        {
+            const out = [];
+            for (let i = 0; i < node.length; i++)
+            {
+                const item = stringify(node, i, node[i], level+1) || JSON.stringify(null);
+                out.push(indent + space + item);
+            }
+            return '[' + out.join(',') + indent + ']';
+        }
+        else
+        {
+            if (seen.has(node))
+            {
+                if (cycles)
+                    return JSON.stringify('__cycle__');
+                throw new TypeError('Converting circular structure to JSON');
+            }
+            else
+                seen.set(node, true);
+            const keys = Object.keys(node).sort(cmp && cmp(node));
+            const out = [];
+            for (let i = 0; i < keys.length; i++)
+            {
+                const key = keys[i];
+                const value = stringify(node, key, node[key], level+1);
+                if (!value)
+                    continue;
+                const keyValue = JSON.stringify(key)
+                    + colonSeparator
+                    + value;
+                out.push(indent + space + keyValue);
+            }
+            seen.delete(node);
+            return '{' + out.join(',') + indent + '}';
+        }
+    })({ '': obj }, '', obj, 0);
+}
+
+module.exports = stableStringify;

mon/test-nonuniform.js

@@ -0,0 +1,130 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+// Interesting real-world example coming from Ceph with EC and compression enabled.
+// EC parity chunks can't be compressed as efficiently as data chunks,
+// thus they occupy more space (2.26x more space) in OSD object stores.
+// This leads to really uneven OSD fill ratio in Ceph even when PGs are perfectly balanced.
+// But we support this case with the "parity_space" parameter in optimize_initial()/optimize_change().
+
+const LPOptimizer = require('./lp-optimizer.js');
+
+const osd_tree = {
+    ripper5: {
+        osd0: 3.493144989013672,
+        osd1: 3.493144989013672,
+        osd2: 3.454082489013672,
+        osd12: 3.461894989013672,
+    },
+    ripper7: {
+        osd4: 3.638690948486328,
+        osd5: 3.638690948486328,
+        osd6: 3.638690948486328,
+    },
+    ripper4: {
+        osd9: 3.4609375,
+        osd10: 3.4609375,
+        osd11: 3.4609375,
+    },
+    ripper6: {
+        osd3: 3.5849609375,
+        osd7: 3.5859336853027344,
+        osd8: 3.638690948486328,
+        osd13: 3.461894989013672
+    },
+};
+
+const prev_pgs = [[12,7,5],[6,11,12],[3,6,9],[10,0,5],[2,5,13],[9,8,6],[3,4,12],[7,4,12],[12,11,13],[13,6,0],[4,13,10],[9,7,6],[7,10,0],[10,8,0],[3,10,2],[3,0,4],[6,13,0],[13,10,0],[13,10,5],[8,11,6],[3,9,2],[2,8,5],[8,9,5],[3,12,11],[0,7,4],[13,11,1],[11,3,12],[12,8,10],[7,5,12],[2,13,5],[7,11,0],[13,2,6],[0,6,8],[13,1,6],[0,13,4],[0,8,10],[4,10,0],[8,12,4],[8,12,9],[12,7,4],[13,9,5],[3,2,11],[1,9,7],[1,8,5],[5,12,9],[3,5,12],[2,8,10],[0,8,4],[1,4,11],[7,10,2],[12,13,5],[3,1,11],[7,1,4],[4,12,8],[7,0,9],[11,1,8],[3,0,5],[11,13,0],[1,13,5],[12,7,10],[12,8,4],[11,13,5],[0,11,6],[2,11,3],[13,1,11],[2,7,10],[7,10,12],[7,12,10],[12,11,5],[13,12,10],[2,3,9],[4,3,9],[13,2,5],[7,12,6],[12,10,13],[9,8,1],[13,1,5],[9,5,12],[5,11,7],[6,2,9],[8,11,6],[12,5,8],[6,13,1],[7,6,11],[2,3,6],[8,5,9],[1,13,6],[9,3,2],[7,11,1],[3,10,1],[0,11,7],[3,0,5],[1,3,6],[6,0,9],[3,11,4],[8,10,2],[13,1,9],[12,6,9],[3,12,9],[12,8,9],[7,5,0],[8,12,5],[0,11,3],[12,11,13],[0,7,11],[0,3,10],[1,3,11],[2,7,11],[13,2,6],[9,12,13],[8,2,4],[0,7,4],[5,13,0],[13,12,9],[1,9,8],[0,10,3],[3,5,10],[7,12,9],[2,13,4],[12,7,5],[9,2,7],[3,2,9],[6,2,7],[3,1,9],[4,3,2],[5,3,11],[0,7,6],[1,6,13],[7,10,2],[12,4,8],[13,12,6],[7,5,11],[6,2,3],[2,7,6],[2,3,10],[2,7,10],[11,12,6],[0,13,5],[10,2,4],[13,0,11],[7,0,6],[8,9,4],[8,4,11],[7,11,2],[3,4,2],[6,1,3],[7,2,11],[8,9,4],[11,4,8],[10,3,1],[2,10,13],[1,7,11],[13,11,12],[2,6,9],[10,0,13],[7,10,4],[0,11,13],[13,10,1],[7,5,0],[7,12,10],[3,1,4],[7,1,5],[3,11,5],[7,5,0],[1,3,5],[10,5,12],[0,3,9],[7,1,11],[11,8,12],[3,6,2],[7,12,9],[7,11,12],[4,11,3],[0,11,13],[13,2,5],[1,5,8],[0,11,8],[3,5,1],[11,0,6],[3,11,2],[11,8,12],[4,1,3],[10,13,4],[13,9,6],[2,3,10],[12,7,9],[10,0,4],[10,13,2],[3,11,1],[7,2,9],[1,7,4],[13,1,4],[7,0,6],[5,3,9],[10,0,7],[0,7,10],[3,6,10],[13,0,5],[8,4,1],[3,1,10],[2,10,13],[13,0,5],[13,10,2],[12,7,9],[6,8,10],[6,1,8],[10,8,1],[13,5,0],[5,11,3],[7,6,1],[8,5,9],[2,13,11],[10,12,4],[13,4,1],[2,13,4],[11,7,0],[2,9,7],[1,7,6],[8,0,4],[8,1,9],[7,10,12],[13,9,6],[7,6,11],[13,0,4],[1,8,4],[3,12,5],[10,3,1],[10,2,13],[2,4,8],[6,2,3],[3,0,10],[6,7,12],[8,12,5],[3,0,6],[13,12,10],[11,3,6],[9,0,13],[10,0,6],[7,5,2],[1,3,11],[7,10,2],[2,9,8],[11,13,12],[0,8,4],[8,12,11],[6,0,3],[1,13,4],[11,8,2],[12,3,6],[4,7,1],[7,6,12],[3,10,6],[0,10,7],[8,9,1],[0,10,6],[8,10,1]]
+    .map(pg => pg.map(n => 'osd'+n));
+
+const by_osd = {};
+
+for (let i = 0; i < prev_pgs.length; i++)
+{
+    for (let j = 0; j < prev_pgs[i].length; j++)
+    {
+        by_osd[prev_pgs[i][j]] = by_osd[prev_pgs[i][j]] || [];
+        by_osd[prev_pgs[i][j]][j] = (by_osd[prev_pgs[i][j]][j] || 0) + 1;
+    }
+}
+
+/*
+
+This set of PGs was balanced by hand, by heavily tuning OSD weights in Ceph:
+
+{
+  osd0: 4.2,
+  osd1: 3.5,
+  osd2: 3.45409,
+  osd3: 4.5,
+  osd4: 1.4,
+  osd5: 1.4,
+  osd6: 1.75,
+  osd7: 4.5,
+  osd8: 4.4,
+  osd9: 2.2,
+  osd10: 2.7,
+  osd11: 2,
+  osd12: 3.4,
+  osd13: 3.4,
+}
+
+EC+compression is a nightmare in Ceph, yeah :))
+
+To calculate the average ratio between data chunks and parity chunks we
+calculate the number of PG chunks for each chunk role for each OSD:
+
+{
+  osd12: [ 18, 22, 17 ],
+  osd7: [ 35, 22, 8 ],
+  osd5: [ 6, 17, 27 ],
+  osd6: [ 13, 12, 28 ],
+  osd11: [ 13, 26, 20 ],
+  osd3: [ 30, 20, 10 ],
+  osd9: [ 8, 12, 26 ],
+  osd10: [ 15, 23, 20 ],
+  osd0: [ 22, 22, 14 ],
+  osd2: [ 22, 16, 16 ],
+  osd13: [ 29, 19, 13 ],
+  osd8: [ 20, 18, 12 ],
+  osd4: [ 8, 10, 28 ],
+  osd1: [ 17, 17, 17 ]
+}
+
+And now we can pick a pair of OSDs and determine the ratio by solving the following:
+
+osd5 = 23*X + 27*Y = 3249728140
+osd13 = 48*X + 13*Y = 2991675992
+
+=>
+
+osd5 - 27/13*osd13 = 23*X - 27/13*48*X = -76.6923076923077*X = -2963752766.46154
+
+=>
+
+X = 38644720.1243731
+Y = (osd5-23*X)/27 = 87440725.0792377
+Y/X = 2.26268232239284 ~= 2.26
+
+Which means that parity chunks are compressed ~2.26 times worse than data chunks.
+
+Fine, let's try to optimize for it.
+
+*/
+
+async function run()
+{
+    const all_weights = Object.assign({}, ...Object.values(osd_tree));
+    const total_weight = Object.values(all_weights).reduce((a, c) => Number(a) + Number(c), 0);
+    const eff = LPOptimizer.pg_list_space_efficiency(prev_pgs, all_weights, 2, 2.26);
+    const orig = eff*4.26 / total_weight;
+    console.log('Original efficiency was: '+Math.round(orig*10000)/100+' %');
+
+    let prev = await LPOptimizer.optimize_initial({ osd_tree, pg_size: 3, pg_count: 256, parity_space: 2.26 });
+    LPOptimizer.print_change_stats(prev);
+
+    let next = await LPOptimizer.optimize_change({ prev_pgs, osd_tree, pg_size: 3, max_combinations: 10000, parity_space: 2.26 });
+    LPOptimizer.print_change_stats(next);
+}
+
+run().catch(console.error);

mon/test-optimize-undersized.js

@@ -0,0 +1,74 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+const LPOptimizer = require('./lp-optimizer.js');
+
+const crush_tree = [
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 1, size: 3 },
+            { level: 3, id: 2, size: 3 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 3, size: 3 },
+            { level: 3, id: 4, size: 3 },
+        ] },
+    ] },
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 5, size: 3 },
+            { level: 3, id: 6, size: 3 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 7, size: 3 },
+            { level: 3, id: 8, size: 3 },
+        ] },
+    ] },
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 9, size: 3 },
+            { level: 3, id: 10, size: 3 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 11, size: 3 },
+            { level: 3, id: 12, size: 3 },
+        ] },
+    ] },
+];
+
+const osd_tree = LPOptimizer.flatten_tree(crush_tree, {}, 1, 3);
+console.log(osd_tree);
+
+async function run()
+{
+    const cur_tree = {};
+    console.log('Empty tree:');
+    let res = await LPOptimizer.optimize_initial({ osd_tree: cur_tree, pg_size: 3, pg_count: 256 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nAdding 1st failure domain:');
+    cur_tree['dom1'] = osd_tree['dom1'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nAdding 2nd failure domain:');
+    cur_tree['dom2'] = osd_tree['dom2'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nAdding 3rd failure domain:');
+    cur_tree['dom3'] = osd_tree['dom3'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nRemoving 3rd failure domain:');
+    delete cur_tree['dom3'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nRemoving 2nd failure domain:');
+    delete cur_tree['dom2'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nRemoving 1st failure domain:');
+    delete cur_tree['dom1'];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree: cur_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+}
+
+run().catch(console.error);

mon/test-optimize.js

@@ -0,0 +1,115 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+const LPOptimizer = require('./lp-optimizer.js');
+
+const osd_tree = {
+    100: {
+        7: 3.63869,
+    },
+    300: {
+        10: 3.46089,
+        11: 3.46089,
+        12: 3.46089,
+    },
+    400: {
+        1: 3.49309,
+        2: 3.49309,
+        3: 3.49309,
+    },
+    500: {
+        4: 3.58498,
+//        8: 3.58589,
+        9: 3.63869,
+    },
+    600: {
+        5: 3.63869,
+        6: 3.63869,
+    },
+/*    100: {
+        1: 2.72800,
+    },
+    200: {
+        2: 2.72900,
+    },
+    300: {
+        3: 1.87000,
+    },
+    400: {
+        4: 1.87000,
+    },
+    500: {
+        5: 3.63869,
+    },*/
+};
+
+const crush_tree = [
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 1, size: 3 },
+            { level: 3, id: 2, size: 2 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 3, size: 4 },
+            { level: 3, id: 4, size: 4 },
+        ] },
+    ] },
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 5, size: 4 },
+            { level: 3, id: 6, size: 1 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 7, size: 3 },
+            { level: 3, id: 8, size: 5 },
+        ] },
+    ] },
+    { level: 1, children: [
+        { level: 2, children: [
+            { level: 3, id: 9, size: 5 },
+            { level: 3, id: 10, size: 2 },
+        ] },
+        { level: 2, children: [
+            { level: 3, id: 11, size: 3 },
+            { level: 3, id: 12, size: 3 },
+        ] },
+    ] },
+];
+
+async function run()
+{
+    let res;
+
+    // Test: add 1 OSD of almost the same size. Ideal data movement could be 1/12 = 8.33%. Actual is ~13%
+    // Space efficiency is ~99% in all cases.
+
+    console.log('256 PGs, size=2');
+    res = await LPOptimizer.optimize_initial({ osd_tree, pg_size: 2, pg_count: 256 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nAdding osd.8');
+    osd_tree[500][8] = 3.58589;
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree, pg_size: 2 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nRemoving osd.8');
+    delete osd_tree[500][8];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree, pg_size: 2 });
+    LPOptimizer.print_change_stats(res, false);
+
+    console.log('\n256 PGs, size=3');
+    res = await LPOptimizer.optimize_initial({ osd_tree, pg_size: 3, pg_count: 256 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nAdding osd.8');
+    osd_tree[500][8] = 3.58589;
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+    console.log('\nRemoving osd.8');
+    delete osd_tree[500][8];
+    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree, pg_size: 3 });
+    LPOptimizer.print_change_stats(res, false);
+
+    console.log('\n256 PGs, size=3, failure domain=rack');
+    res = await LPOptimizer.optimize_initial({ osd_tree: LPOptimizer.flatten_tree(crush_tree, {}, 1, 3), pg_size: 3, pg_count: 256 });
+    LPOptimizer.print_change_stats(res, false);
+}
+
+run().catch(console.error);

msgr_receive.cpp

@@ -0,0 +1,307 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "messenger.h"
+
+void osd_messenger_t::read_requests()
+{
+    for (int i = 0; i < read_ready_clients.size(); i++)
+    {
+        int peer_fd = read_ready_clients[i];
+        auto & cl = clients[peer_fd];
+        if (cl.read_remaining < receive_buffer_size)
+        {
+            cl.read_iov.iov_base = cl.in_buf;
+            cl.read_iov.iov_len = receive_buffer_size;
+            cl.read_msg.msg_iov = &cl.read_iov;
+            cl.read_msg.msg_iovlen = 1;
+        }
+        else
+        {
+            cl.read_iov.iov_base = 0;
+            cl.read_iov.iov_len = cl.read_remaining;
+            cl.read_msg.msg_iov = cl.recv_list.get_iovec();
+            cl.read_msg.msg_iovlen = cl.recv_list.get_size();
+        }
+        if (ringloop && !use_sync_send_recv)
+        {
+            io_uring_sqe* sqe = ringloop->get_sqe();
+            if (!sqe)
+            {
+                read_ready_clients.erase(read_ready_clients.begin(), read_ready_clients.begin() + i);
+                return;
+            }
+            ring_data_t* data = ((ring_data_t*)sqe->user_data);
+            data->callback = [this, peer_fd](ring_data_t *data) { handle_read(data->res, peer_fd); };
+            my_uring_prep_recvmsg(sqe, peer_fd, &cl.read_msg, 0);
+        }
+        else
+        {
+            int result = recvmsg(peer_fd, &cl.read_msg, 0);
+            if (result < 0)
+            {
+                result = -errno;
+            }
+            handle_read(result, peer_fd);
+        }
+    }
+    read_ready_clients.clear();
+}
+
+bool osd_messenger_t::handle_read(int result, int peer_fd)
+{
+    bool ret = false;
+    auto cl_it = clients.find(peer_fd);
+    if (cl_it != clients.end())
+    {
+        auto & cl = cl_it->second;
+        if (result <= 0 && result != -EAGAIN)
+        {
+            // this is a client socket, so don't panic on error. just disconnect it
+            if (result != 0)
+            {
+                printf("Client %d socket read error: %d (%s). Disconnecting client\n", peer_fd, -result, strerror(-result));
+            }
+            stop_client(peer_fd);
+            return false;
+        }
+        if (result == -EAGAIN || result < cl.read_iov.iov_len)
+        {
+            cl.read_ready--;
+            if (cl.read_ready > 0)
+                read_ready_clients.push_back(peer_fd);
+        }
+        else
+        {
+            read_ready_clients.push_back(peer_fd);
+        }
+        if (result > 0)
+        {
+            if (cl.read_iov.iov_base == cl.in_buf)
+            {
+                // Compose operation(s) from the buffer
+                int remain = result;
+                void *curbuf = cl.in_buf;
+                while (remain > 0)
+                {
+                    if (!cl.read_op)
+                    {
+                        cl.read_op = new osd_op_t;
+                        cl.read_op->peer_fd = peer_fd;
+                        cl.read_op->op_type = OSD_OP_IN;
+                        cl.recv_list.push_back(cl.read_op->req.buf, OSD_PACKET_SIZE);
+                        cl.read_remaining = OSD_PACKET_SIZE;
+                        cl.read_state = CL_READ_HDR;
+                    }
+                    while (cl.recv_list.done < cl.recv_list.count && remain > 0)
+                    {
+                        iovec* cur = cl.recv_list.get_iovec();
+                        if (cur->iov_len > remain)
+                        {
+                            memcpy(cur->iov_base, curbuf, remain);
+                            cl.read_remaining -= remain;
+                            cur->iov_len -= remain;
+                            cur->iov_base += remain;
+                            remain = 0;
+                        }
+                        else
+                        {
+                            memcpy(cur->iov_base, curbuf, cur->iov_len);
+                            curbuf += cur->iov_len;
+                            cl.read_remaining -= cur->iov_len;
+                            remain -= cur->iov_len;
+                            cur->iov_len = 0;
+                            cl.recv_list.done++;
+                        }
+                    }
+                    if (cl.recv_list.done >= cl.recv_list.count)
+                    {
+                        if (!handle_finished_read(cl))
+                        {
+                            goto fin;
+                        }
+                    }
+                }
+            }
+            else
+            {
+                // Long data
+                cl.read_remaining -= result;
+                cl.recv_list.eat(result);
+                if (cl.recv_list.done >= cl.recv_list.count)
+                {
+                    handle_finished_read(cl);
+                }
+            }
+            if (result >= cl.read_iov.iov_len)
+            {
+                ret = true;
+            }
+        }
+    }
+fin:
+    for (auto cb: set_immediate)
+    {
+        cb();
+    }
+    set_immediate.clear();
+    return ret;
+}
+
+bool osd_messenger_t::handle_finished_read(osd_client_t & cl)
+{
+    cl.recv_list.reset();
+    if (cl.read_state == CL_READ_HDR)
+    {
+        if (cl.read_op->req.hdr.magic == SECONDARY_OSD_REPLY_MAGIC)
+            return handle_reply_hdr(&cl);
+        else
+            handle_op_hdr(&cl);
+    }
+    else if (cl.read_state == CL_READ_DATA)
+    {
+        // Operation is ready
+        cl.received_ops.push_back(cl.read_op);
+        set_immediate.push_back([this, op = cl.read_op]() { exec_op(op); });
+        cl.read_op = NULL;
+        cl.read_state = 0;
+    }
+    else if (cl.read_state == CL_READ_REPLY_DATA)
+    {
+        // Reply is ready
+        handle_reply_ready(cl.read_op);
+        cl.read_op = NULL;
+        cl.read_state = 0;
+    }
+    else
+    {
+        assert(0);
+    }
+    return true;
+}
+
+void osd_messenger_t::handle_op_hdr(osd_client_t *cl)
+{
+    osd_op_t *cur_op = cl->read_op;
+    if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ)
+    {
+        if (cur_op->req.sec_rw.len > 0)
+            cur_op->buf = memalign_or_die(MEM_ALIGNMENT, cur_op->req.sec_rw.len);
+        cl->read_remaining = 0;
+    }
+    else if (cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+        cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
+    {
+        if (cur_op->req.sec_rw.len > 0)
+            cur_op->buf = memalign_or_die(MEM_ALIGNMENT, cur_op->req.sec_rw.len);
+        cl->read_remaining = cur_op->req.sec_rw.len;
+    }
+    else if (cur_op->req.hdr.opcode == OSD_OP_SEC_STABILIZE ||
+        cur_op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK)
+    {
+        if (cur_op->req.sec_stab.len > 0)
+            cur_op->buf = memalign_or_die(MEM_ALIGNMENT, cur_op->req.sec_stab.len);
+        cl->read_remaining = cur_op->req.sec_stab.len;
+    }
+    else if (cur_op->req.hdr.opcode == OSD_OP_READ)
+    {
+        cl->read_remaining = 0;
+    }
+    else if (cur_op->req.hdr.opcode == OSD_OP_WRITE)
+    {
+        if (cur_op->req.rw.len > 0)
+            cur_op->buf = memalign_or_die(MEM_ALIGNMENT, cur_op->req.rw.len);
+        cl->read_remaining = cur_op->req.rw.len;
+    }
+    if (cl->read_remaining > 0)
+    {
+        // Read data
+        cl->recv_list.push_back(cur_op->buf, cl->read_remaining);
+        cl->read_state = CL_READ_DATA;
+    }
+    else
+    {
+        // Operation is ready
+        cl->received_ops.push_back(cur_op);
+        set_immediate.push_back([this, cur_op]() { exec_op(cur_op); });
+        cl->read_op = NULL;
+        cl->read_state = 0;
+    }
+}
+
+bool osd_messenger_t::handle_reply_hdr(osd_client_t *cl)
+{
+    auto req_it = cl->sent_ops.find(cl->read_op->req.hdr.id);
+    if (req_it == cl->sent_ops.end())
+    {
+        // Command out of sync. Drop connection
+        printf("Client %d command out of sync: id %lu\n", cl->peer_fd, cl->read_op->req.hdr.id);
+        stop_client(cl->peer_fd);
+        return false;
+    }
+    osd_op_t *op = req_it->second;
+    memcpy(op->reply.buf, cl->read_op->req.buf, OSD_PACKET_SIZE);
+    cl->sent_ops.erase(req_it);
+    if ((op->reply.hdr.opcode == OSD_OP_SEC_READ || op->reply.hdr.opcode == OSD_OP_READ) &&
+        op->reply.hdr.retval > 0)
+    {
+        // Read data. In this case we assume that the buffer is preallocated by the caller (!)
+        assert(op->iov.count > 0);
+        cl->recv_list.append(op->iov);
+        delete cl->read_op;
+        cl->read_op = op;
+        cl->read_state = CL_READ_REPLY_DATA;
+        cl->read_remaining = op->reply.hdr.retval;
+    }
+    else if (op->reply.hdr.opcode == OSD_OP_SEC_LIST && op->reply.hdr.retval > 0)
+    {
+        assert(!op->iov.count);
+        delete cl->read_op;
+        cl->read_op = op;
+        cl->read_state = CL_READ_REPLY_DATA;
+        cl->read_remaining = sizeof(obj_ver_id) * op->reply.hdr.retval;
+        op->buf = memalign_or_die(MEM_ALIGNMENT, cl->read_remaining);
+        cl->recv_list.push_back(op->buf, cl->read_remaining);
+    }
+    else if (op->reply.hdr.opcode == OSD_OP_SHOW_CONFIG && op->reply.hdr.retval > 0)
+    {
+        assert(!op->iov.count);
+        delete cl->read_op;
+        cl->read_op = op;
+        cl->read_state = CL_READ_REPLY_DATA;
+        cl->read_remaining = op->reply.hdr.retval;
+        op->buf = malloc_or_die(op->reply.hdr.retval);
+        cl->recv_list.push_back(op->buf, op->reply.hdr.retval);
+    }
+    else
+    {
+        // It's fine to reuse cl->read_op for the next reply
+        handle_reply_ready(op);
+        cl->recv_list.push_back(cl->read_op->req.buf, OSD_PACKET_SIZE);
+        cl->read_remaining = OSD_PACKET_SIZE;
+        cl->read_state = CL_READ_HDR;
+    }
+    return true;
+}
+
+void osd_messenger_t::handle_reply_ready(osd_op_t *op)
+{
+    // Measure subop latency
+    timespec tv_end;
+    clock_gettime(CLOCK_REALTIME, &tv_end);
+    stats.subop_stat_count[op->req.hdr.opcode]++;
+    if (!stats.subop_stat_count[op->req.hdr.opcode])
+    {
+        stats.subop_stat_count[op->req.hdr.opcode]++;
+        stats.subop_stat_sum[op->req.hdr.opcode] = 0;
+    }
+    stats.subop_stat_sum[op->req.hdr.opcode] += (
+        (tv_end.tv_sec - op->tv_begin.tv_sec)*1000000 +
+        (tv_end.tv_nsec - op->tv_begin.tv_nsec)/1000
+    );
+    set_immediate.push_back([this, op]()
+    {
+        // Copy lambda to be unaffected by `delete op`
+        std::function<void(osd_op_t*)>(op->callback)(op);
+    });
+}

msgr_send.cpp

@@ -0,0 +1,186 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "messenger.h"
+
+void osd_messenger_t::outbox_push(osd_op_t *cur_op)
+{
+    assert(cur_op->peer_fd);
+    auto & cl = clients.at(cur_op->peer_fd);
+    if (cur_op->op_type == OSD_OP_OUT)
+    {
+        clock_gettime(CLOCK_REALTIME, &cur_op->tv_begin);
+    }
+    else
+    {
+        // Check that operation actually belongs to this client
+        bool found = false;
+        for (auto it = cl.received_ops.begin(); it != cl.received_ops.end(); it++)
+        {
+            if (*it == cur_op)
+            {
+                found = true;
+                cl.received_ops.erase(it, it+1);
+                break;
+            }
+        }
+        if (!found)
+        {
+            delete cur_op;
+            return;
+        }
+    }
+    cl.outbox.push_back(cur_op);
+    if (!ringloop)
+    {
+        while (cl.write_op || cl.outbox.size())
+        {
+            try_send(cl);
+        }
+    }
+    else if (cl.write_op || cl.outbox.size() > 1 || !try_send(cl))
+    {
+        if (cl.write_state == 0)
+        {
+            cl.write_state = CL_WRITE_READY;
+            write_ready_clients.push_back(cur_op->peer_fd);
+        }
+        ringloop->wakeup();
+    }
+}
+
+bool osd_messenger_t::try_send(osd_client_t & cl)
+{
+    int peer_fd = cl.peer_fd;
+    if (!cl.write_op)
+    {
+        // pick next command
+        cl.write_op = cl.outbox.front();
+        cl.outbox.pop_front();
+        cl.write_state = CL_WRITE_REPLY;
+        if (cl.write_op->op_type == OSD_OP_IN)
+        {
+            // Measure execution latency
+            timespec tv_end;
+            clock_gettime(CLOCK_REALTIME, &tv_end);
+            stats.op_stat_count[cl.write_op->req.hdr.opcode]++;
+            if (!stats.op_stat_count[cl.write_op->req.hdr.opcode])
+            {
+                stats.op_stat_count[cl.write_op->req.hdr.opcode]++;
+                stats.op_stat_sum[cl.write_op->req.hdr.opcode] = 0;
+                stats.op_stat_bytes[cl.write_op->req.hdr.opcode] = 0;
+            }
+            stats.op_stat_sum[cl.write_op->req.hdr.opcode] += (
+                (tv_end.tv_sec - cl.write_op->tv_begin.tv_sec)*1000000 +
+                (tv_end.tv_nsec - cl.write_op->tv_begin.tv_nsec)/1000
+            );
+            if (cl.write_op->req.hdr.opcode == OSD_OP_READ ||
+                cl.write_op->req.hdr.opcode == OSD_OP_WRITE)
+            {
+                stats.op_stat_bytes[cl.write_op->req.hdr.opcode] += cl.write_op->req.rw.len;
+            }
+            else if (cl.write_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
+            {
+                stats.op_stat_bytes[cl.write_op->req.hdr.opcode] += cl.write_op->req.sec_rw.len;
+            }
+            cl.send_list.push_back(cl.write_op->reply.buf, OSD_PACKET_SIZE);
+            if (cl.write_op->req.hdr.opcode == OSD_OP_READ ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_LIST ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SHOW_CONFIG)
+            {
+                cl.send_list.append(cl.write_op->iov);
+            }
+        }
+        else
+        {
+            cl.send_list.push_back(cl.write_op->req.buf, OSD_PACKET_SIZE);
+            if (cl.write_op->req.hdr.opcode == OSD_OP_WRITE ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_STABILIZE ||
+                cl.write_op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK)
+            {
+                cl.send_list.append(cl.write_op->iov);
+            }
+        }
+    }
+    cl.write_msg.msg_iov = cl.send_list.get_iovec();
+    cl.write_msg.msg_iovlen = cl.send_list.get_size();
+    if (ringloop && !use_sync_send_recv)
+    {
+        io_uring_sqe* sqe = ringloop->get_sqe();
+        if (!sqe)
+        {
+            return false;
+        }
+        ring_data_t* data = ((ring_data_t*)sqe->user_data);
+        data->callback = [this, peer_fd](ring_data_t *data) { handle_send(data->res, peer_fd); };
+        my_uring_prep_sendmsg(sqe, peer_fd, &cl.write_msg, 0);
+    }
+    else
+    {
+        int result = sendmsg(peer_fd, &cl.write_msg, MSG_NOSIGNAL);
+        if (result < 0)
+        {
+            result = -errno;
+        }
+        handle_send(result, peer_fd);
+    }
+    return true;
+}
+
+void osd_messenger_t::send_replies()
+{
+    for (int i = 0; i < write_ready_clients.size(); i++)
+    {
+        int peer_fd = write_ready_clients[i];
+        if (!try_send(clients[peer_fd]))
+        {
+            write_ready_clients.erase(write_ready_clients.begin(), write_ready_clients.begin() + i);
+            return;
+        }
+    }
+    write_ready_clients.clear();
+}
+
+void osd_messenger_t::handle_send(int result, int peer_fd)
+{
+    auto cl_it = clients.find(peer_fd);
+    if (cl_it != clients.end())
+    {
+        auto & cl = cl_it->second;
+        if (result < 0 && result != -EAGAIN)
+        {
+            // this is a client socket, so don't panic. just disconnect it
+            printf("Client %d socket write error: %d (%s). Disconnecting client\n", peer_fd, -result, strerror(-result));
+            stop_client(peer_fd);
+            return;
+        }
+        if (result >= 0)
+        {
+            cl.send_list.eat(result);
+            if (cl.send_list.done >= cl.send_list.count)
+            {
+                // Done
+                cl.send_list.reset();
+                if (cl.write_op->op_type == OSD_OP_IN)
+                {
+                    delete cl.write_op;
+                }
+                else
+                {
+                    cl.sent_ops[cl.write_op->req.hdr.id] = cl.write_op;
+                }
+                cl.write_op = NULL;
+                cl.write_state = cl.outbox.size() > 0 ? CL_WRITE_READY : 0;
+            }
+        }
+        if (cl.write_state != 0)
+        {
+            write_ready_clients.push_back(peer_fd);
+        }
+    }
+}

nbd_proxy.cpp

@@ -0,0 +1,673 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+// Similar to qemu-nbd, but sets timeout and uses io_uring
+
+#include <linux/nbd.h>
+#include <sys/ioctl.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include "epoll_manager.h"
+#include "cluster_client.h"
+
+const char *exe_name = NULL;
+
+class nbd_proxy
+{
+protected:
+    uint64_t inode = 0;
+
+    ring_loop_t *ringloop = NULL;
+    epoll_manager_t *epmgr = NULL;
+    cluster_client_t *cli = NULL;
+    ring_consumer_t consumer;
+
+    std::vector<iovec> send_list, next_send_list;
+    std::vector<void*> to_free;
+    int nbd_fd = -1;
+    void *recv_buf = NULL;
+    int receive_buffer_size = 9000;
+    nbd_request cur_req;
+    cluster_op_t *cur_op = NULL;
+    void *cur_buf = NULL;
+    int cur_left = 0;
+    int read_state = 0;
+    int read_ready = 0;
+    msghdr read_msg = { 0 }, send_msg = { 0 };
+    iovec read_iov = { 0 };
+
+public:
+    static json11::Json::object parse_args(int narg, const char *args[])
+    {
+        json11::Json::object cfg;
+        int pos = 0;
+        for (int i = 1; i < narg; i++)
+        {
+            if (!strcmp(args[i], "-h") || !strcmp(args[i], "--help"))
+            {
+                help();
+            }
+            else if (args[i][0] == '-' && args[i][1] == '-')
+            {
+                const char *opt = args[i]+2;
+                cfg[opt] = !strcmp(opt, "json") || i == narg-1 ? "1" : args[++i];
+            }
+            else if (pos == 0)
+            {
+                cfg["command"] = args[i];
+                pos++;
+            }
+            else if (pos == 1 && (cfg["command"] == "map" || cfg["command"] == "unmap"))
+            {
+                int n = 0;
+                if (sscanf(args[i], "/dev/nbd%d", &n) > 0)
+                    cfg["dev_num"] = n;
+                else
+                    cfg["dev_num"] = args[i];
+                pos++;
+            }
+        }
+        return cfg;
+    }
+
+    void exec(json11::Json cfg)
+    {
+        if (cfg["command"] == "map")
+        {
+            start(cfg);
+        }
+        else if (cfg["command"] == "unmap")
+        {
+            if (cfg["dev_num"].is_null())
+            {
+                fprintf(stderr, "device name or number is missing\n");
+                exit(1);
+            }
+            unmap(cfg["dev_num"].uint64_value());
+        }
+        else if (cfg["command"] == "list" || cfg["command"] == "list-mapped")
+        {
+            auto mapped = list_mapped();
+            print_mapped(mapped, !cfg["json"].is_null());
+        }
+        else
+        {
+            help();
+        }
+    }
+
+    static void help()
+    {
+        printf(
+            "Vitastor NBD proxy\n"
+            "(c) Vitaliy Filippov, 2020 (VNPL-1.0 or GNU GPL 2.0+)\n\n"
+            "USAGE:\n"
+            "  %s map --etcd_address <etcd_address> --pool <pool> --inode <inode> --size <size in bytes>\n"
+            "  %s unmap /dev/nbd0\n"
+            "  %s list [--json]\n",
+            exe_name, exe_name, exe_name
+        );
+        exit(0);
+    }
+
+    void unmap(int dev_num)
+    {
+        char path[64] = { 0 };
+        sprintf(path, "/dev/nbd%d", dev_num);
+        int r, nbd = open(path, O_RDWR);
+        if (nbd < 0)
+        {
+            perror("open");
+            exit(1);
+        }
+        r = ioctl(nbd, NBD_DISCONNECT);
+        if (r < 0)
+        {
+            perror("NBD_DISCONNECT");
+            exit(1);
+        }
+        close(nbd);
+    }
+
+    void start(json11::Json cfg)
+    {
+        // Check options
+        if (cfg["etcd_address"].string_value() == "")
+        {
+            fprintf(stderr, "etcd_address is missing\n");
+            exit(1);
+        }
+        if (!cfg["size"].uint64_value())
+        {
+            fprintf(stderr, "device size is missing\n");
+            exit(1);
+        }
+        inode = cfg["inode"].uint64_value();
+        uint64_t pool = cfg["pool"].uint64_value();
+        if (pool)
+        {
+            inode = (inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (pool << (64-POOL_ID_BITS));
+        }
+        if (!(inode >> (64-POOL_ID_BITS)))
+        {
+            fprintf(stderr, "pool is missing\n");
+            exit(1);
+        }
+        // Initialize NBD
+        int sockfd[2];
+        if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockfd) < 0)
+        {
+            perror("socketpair");
+            exit(1);
+        }
+        fcntl(sockfd[0], F_SETFL, fcntl(sockfd[0], F_GETFL, 0) | O_NONBLOCK);
+        nbd_fd = sockfd[0];
+        load_module();
+        if (!cfg["dev_num"].is_null())
+        {
+            if (run_nbd(sockfd, cfg["dev_num"].int64_value(), cfg["size"].uint64_value(), NBD_FLAG_SEND_FLUSH, 30) < 0)
+            {
+                perror("run_nbd");
+                exit(1);
+            }
+        }
+        else
+        {
+            // Find an unused device
+            int i = 0;
+            while (true)
+            {
+                int r = run_nbd(sockfd, i, cfg["size"].uint64_value(), NBD_FLAG_SEND_FLUSH, 30);
+                if (r == 0)
+                {
+                    printf("/dev/nbd%d\n", i);
+                    break;
+                }
+                else if (r == -1 && errno == ENOENT)
+                {
+                    fprintf(stderr, "No free NBD devices found\n");
+                    exit(1);
+                }
+                else if (r == -2 && errno == EBUSY)
+                {
+                    i++;
+                }
+                else
+                {
+                    printf("%d %d\n", r, errno);
+                    perror("run_nbd");
+                    exit(1);
+                }
+            }
+        }
+        if (cfg["foreground"].is_null())
+        {
+            daemonize();
+        }
+        // Create client
+        ringloop = new ring_loop_t(512);
+        epmgr = new epoll_manager_t(ringloop);
+        cli = new cluster_client_t(ringloop, epmgr->tfd, cfg);
+        // Initialize read state
+        read_state = CL_READ_HDR;
+        recv_buf = malloc_or_die(receive_buffer_size);
+        cur_buf = &cur_req;
+        cur_left = sizeof(nbd_request);
+        consumer.loop = [this]()
+        {
+            submit_read();
+            submit_send();
+            ringloop->submit();
+        };
+        ringloop->register_consumer(&consumer);
+        // Add FD to epoll
+        epmgr->tfd->set_fd_handler(sockfd[0], false, [this](int peer_fd, int epoll_events)
+        {
+            read_ready++;
+            submit_read();
+        });
+        while (1)
+        {
+            ringloop->loop();
+            ringloop->wait();
+        }
+    }
+
+    void load_module()
+    {
+        if (access("/sys/module/nbd", F_OK))
+        {
+            return;
+        }
+        int r;
+        if ((r = system("modprobe nbd")) != 0)
+        {
+            if (r < 0)
+                perror("Failed to load NBD kernel module");
+            else
+                fprintf(stderr, "Failed to load NBD kernel module\n");
+            exit(1);
+        }
+    }
+
+    void daemonize()
+    {
+        if (fork())
+            exit(0);
+        setsid();
+        if (fork())
+            exit(0);
+        chdir("/");
+        close(0);
+        close(1);
+        close(2);
+        open("/dev/null", O_RDONLY);
+        open("/dev/null", O_WRONLY);
+        open("/dev/null", O_WRONLY);
+    }
+
+    json11::Json::object list_mapped()
+    {
+        const char *self_filename = exe_name;
+        for (int i = 0; exe_name[i] != 0; i++)
+        {
+            if (exe_name[i] == '/')
+                self_filename = exe_name+i+1;
+        }
+        char path[64] = { 0 };
+        json11::Json::object mapped;
+        int dev_num = -1;
+        int pid;
+        while (true)
+        {
+            dev_num++;
+            sprintf(path, "/sys/block/nbd%d", dev_num);
+            if (access(path, F_OK) != 0)
+                break;
+            sprintf(path, "/sys/block/nbd%d/pid", dev_num);
+            std::string pid_str = read_file(path);
+            if (pid_str == "")
+                continue;
+            if (sscanf(pid_str.c_str(), "%d", &pid) < 1)
+            {
+                printf("Failed to read pid from /sys/block/nbd%d/pid\n", dev_num);
+                continue;
+            }
+            sprintf(path, "/proc/%d/cmdline", pid);
+            std::string cmdline = read_file(path);
+            std::vector<const char*> argv;
+            int last = 0;
+            for (int i = 0; i < cmdline.size(); i++)
+            {
+                if (cmdline[i] == 0)
+                {
+                    argv.push_back(cmdline.c_str()+last);
+                    last = i+1;
+                }
+            }
+            if (argv.size() > 0)
+            {
+                const char *pid_filename = argv[0];
+                for (int i = 0; argv[0][i] != 0; i++)
+                {
+                    if (argv[0][i] == '/')
+                        pid_filename = argv[0]+i+1;
+                }
+                if (!strcmp(pid_filename, self_filename))
+                {
+                    json11::Json::object cfg = nbd_proxy::parse_args(argv.size(), argv.data());
+                    if (cfg["command"] == "map")
+                    {
+                        cfg.erase("command");
+                        cfg["pid"] = pid;
+                        mapped["/dev/nbd"+std::to_string(dev_num)] = cfg;
+                    }
+                }
+            }
+        }
+        return mapped;
+    }
+
+    void print_mapped(json11::Json mapped, bool json)
+    {
+        if (json)
+        {
+            printf("%s\n", mapped.dump().c_str());
+        }
+        else
+        {
+            for (auto & dev: mapped.object_items())
+            {
+                printf("%s\n", dev.first.c_str());
+                for (auto & k: dev.second.object_items())
+                {
+                    printf("%s: %s\n", k.first.c_str(), k.second.string_value().c_str());
+                }
+                printf("\n");
+            }
+        }
+    }
+
+    std::string read_file(char *path)
+    {
+        int fd = open(path, O_RDONLY);
+        if (fd < 0)
+        {
+            if (errno == ENOENT)
+                return "";
+            auto err = "open "+std::string(path);
+            perror(err.c_str());
+            exit(1);
+        }
+        std::string r;
+        while (true)
+        {
+            int l = r.size();
+            r.resize(l + 1024);
+            int rd = read(fd, (void*)(r.c_str() + l), 1024);
+            if (rd <= 0)
+            {
+                r.resize(l);
+                break;
+            }
+            r.resize(l + rd);
+        }
+        close(fd);
+        return r;
+    }
+
+protected:
+    int run_nbd(int sockfd[2], int dev_num, uint64_t size, uint64_t flags, unsigned timeout)
+    {
+        // Check handle size
+        assert(sizeof(cur_req.handle) == 8);
+        char path[64] = { 0 };
+        sprintf(path, "/dev/nbd%d", dev_num);
+        int r, nbd = open(path, O_RDWR), qd_fd;
+        if (nbd < 0)
+        {
+            return -1;
+        }
+        r = ioctl(nbd, NBD_SET_SOCK, sockfd[1]);
+        if (r < 0)
+        {
+            goto end_close;
+        }
+        r = ioctl(nbd, NBD_SET_BLKSIZE, 4096);
+        if (r < 0)
+        {
+            goto end_unmap;
+        }
+        r = ioctl(nbd, NBD_SET_SIZE, size);
+        if (r < 0)
+        {
+            goto end_unmap;
+        }
+        ioctl(nbd, NBD_SET_FLAGS, flags);
+        if (timeout >= 0)
+        {
+            r = ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout);
+            if (r < 0)
+            {
+                goto end_unmap;
+            }
+        }
+        // Configure request size
+        sprintf(path, "/sys/block/nbd%d/queue/max_sectors_kb", dev_num);
+        qd_fd = open(path, O_WRONLY);
+        if (qd_fd < 0)
+        {
+            goto end_unmap;
+        }
+        write(qd_fd, "32768", 5);
+        close(qd_fd);
+        if (!fork())
+        {
+            // Run in child
+            close(sockfd[0]);
+            r = ioctl(nbd, NBD_DO_IT);
+            if (r < 0)
+            {
+                fprintf(stderr, "NBD device terminated with error: %s\n", strerror(errno));
+                kill(getppid(), SIGTERM);
+            }
+            close(sockfd[1]);
+            ioctl(nbd, NBD_CLEAR_QUE);
+            ioctl(nbd, NBD_CLEAR_SOCK);
+            exit(0);
+        }
+        close(sockfd[1]);
+        close(nbd);
+        return 0;
+    end_close:
+        r = errno;
+        close(nbd);
+        errno = r;
+        return -2;
+    end_unmap:
+        r = errno;
+        ioctl(nbd, NBD_CLEAR_SOCK);
+        close(nbd);
+        errno = r;
+        return -3;
+    }
+
+    void submit_send()
+    {
+        if (!send_list.size() || send_msg.msg_iovlen > 0)
+        {
+            return;
+        }
+        io_uring_sqe* sqe = ringloop->get_sqe();
+        if (!sqe)
+        {
+            return;
+        }
+        ring_data_t* data = ((ring_data_t*)sqe->user_data);
+        data->callback = [this](ring_data_t *data) { handle_send(data->res); };
+        send_msg.msg_iov = send_list.data();
+        send_msg.msg_iovlen = send_list.size();
+        my_uring_prep_sendmsg(sqe, nbd_fd, &send_msg, MSG_ZEROCOPY);
+    }
+
+    void handle_send(int result)
+    {
+        send_msg.msg_iovlen = 0;
+        if (result < 0 && result != -EAGAIN)
+        {
+            fprintf(stderr, "Socket disconnected: %s\n", strerror(-result));
+            exit(1);
+        }
+        int to_eat = 0;
+        while (result > 0 && to_eat < send_list.size())
+        {
+            if (result >= send_list[to_eat].iov_len)
+            {
+                free(to_free[to_eat]);
+                result -= send_list[to_eat].iov_len;
+                to_eat++;
+            }
+            else
+            {
+                send_list[to_eat].iov_base += result;
+                send_list[to_eat].iov_len -= result;
+                break;
+            }
+        }
+        if (to_eat > 0)
+        {
+            send_list.erase(send_list.begin(), send_list.begin() + to_eat);
+            to_free.erase(to_free.begin(), to_free.begin() + to_eat);
+        }
+        for (int i = 0; i < next_send_list.size(); i++)
+        {
+            send_list.push_back(next_send_list[i]);
+        }
+        next_send_list.clear();
+        if (send_list.size() > 0)
+        {
+            ringloop->wakeup();
+        }
+    }
+
+    void submit_read()
+    {
+        if (!read_ready || read_msg.msg_iovlen > 0)
+        {
+            return;
+        }
+        io_uring_sqe* sqe = ringloop->get_sqe();
+        if (!sqe)
+        {
+            return;
+        }
+        ring_data_t* data = ((ring_data_t*)sqe->user_data);
+        data->callback = [this](ring_data_t *data) { handle_read(data->res); };
+        if (cur_left < receive_buffer_size)
+        {
+            read_iov.iov_base = recv_buf;
+            read_iov.iov_len = receive_buffer_size;
+        }
+        else
+        {
+            read_iov.iov_base = cur_buf;
+            read_iov.iov_len = cur_left;
+        }
+        read_msg.msg_iov = &read_iov;
+        read_msg.msg_iovlen = 1;
+        my_uring_prep_recvmsg(sqe, nbd_fd, &read_msg, 0);
+    }
+
+    void handle_read(int result)
+    {
+        read_msg.msg_iovlen = 0;
+        if (result < 0 && result != -EAGAIN)
+        {
+            fprintf(stderr, "Socket disconnected: %s\n", strerror(-result));
+            exit(1);
+        }
+        if (result == -EAGAIN || result < read_iov.iov_len)
+        {
+            read_ready--;
+        }
+        if (read_ready > 0)
+        {
+            ringloop->wakeup();
+        }
+        void *b = recv_buf;
+        while (result > 0)
+        {
+            if (read_iov.iov_base == recv_buf)
+            {
+                int inc = result >= cur_left ? cur_left : result;
+                memcpy(cur_buf, b, inc);
+                cur_left -= inc;
+                result -= inc;
+                cur_buf += inc;
+                b += inc;
+            }
+            else
+            {
+                assert(result <= cur_left);
+                cur_left -= result;
+                result = 0;
+            }
+            if (cur_left <= 0)
+            {
+                handle_finished_read();
+            }
+        }
+    }
+
+    void handle_finished_read()
+    {
+        if (read_state == CL_READ_HDR)
+        {
+            int req_type = be32toh(cur_req.type);
+            if (be32toh(cur_req.magic) != NBD_REQUEST_MAGIC ||
+                req_type != NBD_CMD_READ && req_type != NBD_CMD_WRITE && req_type != NBD_CMD_FLUSH)
+            {
+                printf("Unexpected request: magic=%x type=%x, terminating\n", cur_req.magic, req_type);
+                exit(1);
+            }
+            uint64_t handle = *((uint64_t*)cur_req.handle);
+#ifdef DEBUG
+            printf("request %lx +%x %lx\n", be64toh(cur_req.from), be32toh(cur_req.len), handle);
+#endif
+            void *buf = NULL;
+            cluster_op_t *op = new cluster_op_t;
+            if (req_type == NBD_CMD_READ || req_type == NBD_CMD_WRITE)
+            {
+                op->opcode = req_type == NBD_CMD_READ ? OSD_OP_READ : OSD_OP_WRITE;
+                op->inode = inode;
+                op->offset = be64toh(cur_req.from);
+                op->len = be32toh(cur_req.len);
+                buf = malloc_or_die(sizeof(nbd_reply) + op->len);
+                op->iov.push_back(buf + sizeof(nbd_reply), op->len);
+            }
+            else if (req_type == NBD_CMD_FLUSH)
+            {
+                op->opcode = OSD_OP_SYNC;
+                buf = malloc_or_die(sizeof(nbd_reply));
+            }
+            op->callback = [this, buf, handle](cluster_op_t *op)
+            {
+#ifdef DEBUG
+                printf("reply %lx e=%d\n", handle, op->retval);
+#endif
+                nbd_reply *reply = (nbd_reply*)buf;
+                reply->magic = htobe32(NBD_REPLY_MAGIC);
+                memcpy(reply->handle, &handle, 8);
+                reply->error = htobe32(op->retval < 0 ? -op->retval : 0);
+                auto & to_list = send_msg.msg_iovlen > 0 ? next_send_list : send_list;
+                if (op->retval < 0 || op->opcode != OSD_OP_READ)
+                    to_list.push_back({ .iov_base = buf, .iov_len = sizeof(nbd_reply) });
+                else
+                    to_list.push_back({ .iov_base = buf, .iov_len = sizeof(nbd_reply) + op->len });
+                to_free.push_back(buf);
+                delete op;
+                ringloop->wakeup();
+            };
+            if (req_type == NBD_CMD_WRITE)
+            {
+                cur_op = op;
+                cur_buf = buf + sizeof(nbd_reply);
+                cur_left = op->len;
+                read_state = CL_READ_DATA;
+            }
+            else
+            {
+                cur_op = NULL;
+                cur_buf = &cur_req;
+                cur_left = sizeof(nbd_request);
+                read_state = CL_READ_HDR;
+                cli->execute(op);
+            }
+        }
+        else
+        {
+            cli->execute(cur_op);
+            cur_op = NULL;
+            cur_buf = &cur_req;
+            cur_left = sizeof(nbd_request);
+            read_state = CL_READ_HDR;
+        }
+    }
+};
+
+int main(int narg, const char *args[])
+{
+    setvbuf(stdout, NULL, _IONBF, 0);
+    setvbuf(stderr, NULL, _IONBF, 0);
+    exe_name = args[0];
+    nbd_proxy *p = new nbd_proxy();
+    p->exec(nbd_proxy::parse_args(narg, args));
+    return 0;
+}

object_id.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #pragma once
 
 #include <stdint.h>

osd.cpp

@@ -1,5 +1,7 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <sys/socket.h>
-#include <sys/epoll.h>
 #include <sys/poll.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
@@ -7,71 +9,100 @@
 
 #include "osd.h"
 
-static const char* osd_op_names[] = {
-    "",
-    "read",
-    "write",
-    "sync",
-    "stabilize",
-    "rollback",
-    "delete",
-    "sync_stab_all",
-    "list",
-    "show_config",
-    "primary_read",
-    "primary_write",
-    "primary_sync",
-};
-
 osd_t::osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringloop)
 {
     this->config = config;
     this->bs = bs;
     this->ringloop = ringloop;
-    this->tick_tfd = new timerfd_interval(ringloop, 3, [this]()
-    {
-        for (int i = 0; i <= OSD_OP_MAX; i++)
-        {
-            if (op_stat_count[i] != 0)
-            {
-                printf("avg latency for op %d (%s): %ld us\n", i, osd_op_names[i], op_stat_sum[i]/op_stat_count[i]);
-                op_stat_count[i] = 0;
-                op_stat_sum[i] = 0;
-            }
-        }
-        for (int i = 0; i <= OSD_OP_MAX; i++)
-        {
-            if (subop_stat_count[i] != 0)
-            {
-                printf("avg latency for subop %d (%s): %ld us\n", i, osd_op_names[i], subop_stat_sum[i]/subop_stat_count[i]);
-                subop_stat_count[i] = 0;
-                subop_stat_sum[i] = 0;
-            }
-        }
-        if (send_stat_count != 0)
-        {
-            printf("avg latency to send stabilize subop: %ld us\n", send_stat_sum/send_stat_count);
-            send_stat_count = 0;
-            send_stat_sum = 0;
-        }
-    });
+
     this->bs_block_size = bs->get_block_size();
     // FIXME: use bitmap granularity instead
     this->bs_disk_alignment = bs->get_disk_alignment();
 
-    bind_address = config["bind_address"];
-    if (bind_address == "")
-        bind_address = "0.0.0.0";
-    bind_port = strtoull(config["bind_port"].c_str(), NULL, 10);
-    if (!bind_port || bind_port > 65535)
-        bind_port = 11203;
+    parse_config(config);
+
+    epmgr = new epoll_manager_t(ringloop);
+    this->tfd = epmgr->tfd;
+
+    this->tfd->set_timer(print_stats_interval*1000, true, [this](int timer_id)
+    {
+        print_stats();
+    });
+
+    c_cli.tfd = this->tfd;
+    c_cli.ringloop = this->ringloop;
+    c_cli.exec_op = [this](osd_op_t *op) { exec_op(op); };
+    c_cli.repeer_pgs = [this](osd_num_t peer_osd) { repeer_pgs(peer_osd); };
+
+    init_cluster();
+
+    consumer.loop = [this]() { loop(); };
+    ringloop->register_consumer(&consumer);
+}
+
+osd_t::~osd_t()
+{
+    ringloop->unregister_consumer(&consumer);
+    delete epmgr;
+    close(listen_fd);
+}
+
+void osd_t::parse_config(blockstore_config_t & config)
+{
+    // Initial startup configuration
+    json11::Json json_config = json11::Json(config);
+    st_cli.parse_config(json_config);
+    etcd_report_interval = strtoull(config["etcd_report_interval"].c_str(), NULL, 10);
+    if (etcd_report_interval <= 0)
+        etcd_report_interval = 30;
     osd_num = strtoull(config["osd_num"].c_str(), NULL, 10);
     if (!osd_num)
         throw std::runtime_error("osd_num is required in the configuration");
-    run_primary = config["run_primary"] == "true" || config["run_primary"] == "1" || config["run_primary"] == "yes";
-    if (run_primary)
-        init_primary();
+    c_cli.osd_num = osd_num;
+    run_primary = config["run_primary"] != "false" && config["run_primary"] != "0" && config["run_primary"] != "no";
+    // Cluster configuration
+    bind_address = config["bind_address"];
+    if (bind_address == "")
+        bind_address = "0.0.0.0";
+    bind_port = stoull_full(config["bind_port"]);
+    if (bind_port <= 0 || bind_port > 65535)
+        bind_port = 0;
+    if (config["immediate_commit"] == "all")
+        immediate_commit = IMMEDIATE_ALL;
+    else if (config["immediate_commit"] == "small")
+        immediate_commit = IMMEDIATE_SMALL;
+    if (config.find("autosync_interval") != config.end())
+    {
+        autosync_interval = strtoull(config["autosync_interval"].c_str(), NULL, 10);
+        if (autosync_interval > MAX_AUTOSYNC_INTERVAL)
+            autosync_interval = DEFAULT_AUTOSYNC_INTERVAL;
+    }
+    if (config.find("client_queue_depth") != config.end())
+    {
+        client_queue_depth = strtoull(config["client_queue_depth"].c_str(), NULL, 10);
+        if (client_queue_depth < 128)
+            client_queue_depth = 128;
+    }
+    recovery_queue_depth = strtoull(config["recovery_queue_depth"].c_str(), NULL, 10);
+    if (recovery_queue_depth < 1 || recovery_queue_depth > MAX_RECOVERY_QUEUE)
+        recovery_queue_depth = DEFAULT_RECOVERY_QUEUE;
+    if (config["readonly"] == "true" || config["readonly"] == "1" || config["readonly"] == "yes")
+        readonly = true;
+    print_stats_interval = strtoull(config["print_stats_interval"].c_str(), NULL, 10);
+    if (!print_stats_interval)
+        print_stats_interval = 3;
+    c_cli.peer_connect_interval = strtoull(config["peer_connect_interval"].c_str(), NULL, 10);
+    if (!c_cli.peer_connect_interval)
+        c_cli.peer_connect_interval = DEFAULT_PEER_CONNECT_INTERVAL;
+    c_cli.peer_connect_timeout = strtoull(config["peer_connect_timeout"].c_str(), NULL, 10);
+    if (!c_cli.peer_connect_timeout)
+        c_cli.peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT;
+    log_level = strtoull(config["log_level"].c_str(), NULL, 10);
+    c_cli.log_level = log_level;
+}
 
+void osd_t::bind_socket()
+{
     listen_fd = socket(AF_INET, SOCK_STREAM, 0);
     if (listen_fd < 0)
     {
@@ -88,13 +119,27 @@ osd_t::osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringlo
         throw std::runtime_error("bind address "+bind_address+(r == 0 ? " is not valid" : ": no ipv4 support"));
     }
     addr.sin_family = AF_INET;
-    addr.sin_port = htons(bind_port);
 
+    addr.sin_port = htons(bind_port);
     if (bind(listen_fd, (sockaddr*)&addr, sizeof(addr)) < 0)
     {
         close(listen_fd);
         throw std::runtime_error(std::string("bind: ") + strerror(errno));
     }
+    if (bind_port == 0)
+    {
+        socklen_t len = sizeof(addr);
+        if (getsockname(listen_fd, (sockaddr *)&addr, &len) == -1)
+        {
+            close(listen_fd);
+            throw std::runtime_error(std::string("getsockname: ") + strerror(errno));
+        }
+        listening_port = ntohs(addr.sin_port);
+    }
+    else
+    {
+        listening_port = bind_port;
+    }
 
     if (listen(listen_fd, listen_backlog) < 0)
     {
@@ -104,56 +149,10 @@ osd_t::osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringlo
 
     fcntl(listen_fd, F_SETFL, fcntl(listen_fd, F_GETFL, 0) | O_NONBLOCK);
 
-    epoll_fd = epoll_create(1);
-    if (epoll_fd < 0)
+    epmgr->set_fd_handler(listen_fd, false, [this](int fd, int events)
     {
-        close(listen_fd);
-        throw std::runtime_error(std::string("epoll_create: ") + strerror(errno));
-    }
-    epoll_fd_index = ringloop->register_fd(epoll_fd);
-
-    epoll_event ev;
-    ev.data.fd = listen_fd;
-    ev.events = EPOLLIN | EPOLLET;
-    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, listen_fd, &ev) < 0)
-    {
-        close(listen_fd);
-        close(epoll_fd);
-        throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
-    }
-
-    consumer.loop = [this]() { loop(); };
-    ringloop->register_consumer(consumer);
-}
-
-osd_t::~osd_t()
-{
-    delete tick_tfd;
-    ringloop->unregister_consumer(consumer);
-    close(epoll_fd);
-    close(listen_fd);
-}
-
-osd_op_t::~osd_op_t()
-{
-    if (bs_op)
-    {
-        delete bs_op;
-    }
-    if (op_data)
-    {
-        free(op_data);
-    }
-    if (rmw_buf)
-    {
-        free(rmw_buf);
-    }
-    if (buf)
-    {
-        // Note: reusing osd_op_t WILL currently lead to memory leaks
-        // So we don't reuse it, but free it every time
-        free(buf);
-    }
+        c_cli.accept_connections(listen_fd);
+    });
 }
 
 bool osd_t::shutdown()
@@ -168,191 +167,12 @@ bool osd_t::shutdown()
 
 void osd_t::loop()
 {
-    if (!wait_state)
-    {
-        handle_epoll_events();
-        wait_state = 1;
-    }
     handle_peers();
-    read_requests();
-    send_replies();
+    c_cli.read_requests();
+    c_cli.send_replies();
     ringloop->submit();
 }
 
-void osd_t::handle_epoll_events()
-{
-    io_uring_sqe *sqe = ringloop->get_sqe();
-    if (!sqe)
-    {
-        throw std::runtime_error("can't get SQE, will fall out of sync with EPOLLET");
-    }
-    ring_data_t *data = ((ring_data_t*)sqe->user_data);
-    data->allow_cancel = true;
-    my_uring_prep_poll_add(sqe, epoll_fd_index, POLLIN);
-    sqe->flags |= IOSQE_FIXED_FILE;
-    data->callback = [this](ring_data_t *data)
-    {
-        if (data->res < 0 && data->res != -ECANCELED)
-        {
-            throw std::runtime_error(std::string("epoll failed: ") + strerror(-data->res));
-        }
-        handle_epoll_events();
-    };
-    ringloop->submit();
-    // FIXME With SQ thread we have no guarantee that epoll request will be submitted right here...
-    int nfds;
-    epoll_event events[MAX_EPOLL_EVENTS];
-restart:
-    nfds = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, 0);
-    for (int i = 0; i < nfds; i++)
-    {
-        if (events[i].data.fd == listen_fd)
-        {
-            // Accept new connections
-            sockaddr_in addr;
-            socklen_t peer_addr_size = sizeof(addr);
-            int peer_fd;
-            while ((peer_fd = accept(listen_fd, (sockaddr*)&addr, &peer_addr_size)) >= 0)
-            {
-                char peer_str[256];
-                printf("osd: new client %d: connection from %s port %d\n", peer_fd, inet_ntop(AF_INET, &addr.sin_addr, peer_str, 256), ntohs(addr.sin_port));
-                fcntl(peer_fd, F_SETFL, fcntl(listen_fd, F_GETFL, 0) | O_NONBLOCK);
-                int one = 1;
-                setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
-                clients[peer_fd] = {
-                    .peer_addr = addr,
-                    .peer_port = ntohs(addr.sin_port),
-                    .peer_fd = peer_fd,
-                    .peer_fd_index = ringloop->register_fd(peer_fd),
-                    .peer_state = PEER_CONNECTED,
-                };
-                // Add FD to epoll
-                epoll_event ev;
-                ev.data.fd = peer_fd;
-                ev.events = EPOLLIN | EPOLLRDHUP | EPOLLET;
-                if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, peer_fd, &ev) < 0)
-                {
-                    throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
-                }
-                // Try to accept next connection
-                peer_addr_size = sizeof(addr);
-            }
-            if (peer_fd == -1 && errno != EAGAIN)
-            {
-                throw std::runtime_error(std::string("accept: ") + strerror(errno));
-            }
-        }
-        else
-        {
-            auto & cl = clients[events[i].data.fd];
-            if (cl.peer_state == PEER_CONNECTING)
-            {
-                // Either OUT (connected) or HUP
-                handle_connect_result(cl.peer_fd);
-            }
-            else if (events[i].events & EPOLLRDHUP)
-            {
-                // Stop client
-                printf("osd: client %d disconnected\n", cl.peer_fd);
-                stop_client(cl.peer_fd);
-            }
-            else
-            {
-                // Mark client as ready (i.e. some data is available)
-                cl.read_ready++;
-                if (cl.read_ready == 1)
-                {
-                    read_ready_clients.push_back(cl.peer_fd);
-                    ringloop->wakeup();
-                }
-            }
-        }
-    }
-    if (nfds > 0)
-    {
-        goto restart;
-    }
-}
-
-void osd_t::cancel_osd_ops(osd_client_t & cl)
-{
-    for (auto p: cl.sent_ops)
-    {
-        cancel_op(p.second);
-    }
-    cl.sent_ops.clear();
-    for (auto op: cl.outbox)
-    {
-        cancel_op(op);
-    }
-    cl.outbox.clear();
-    if (cl.write_op)
-    {
-        cancel_op(cl.write_op);
-        cl.write_op = NULL;
-    }
-}
-
-void osd_t::cancel_op(osd_op_t *op)
-{
-    if (op->op_type == OSD_OP_OUT)
-    {
-        op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
-        op->reply.hdr.id = op->req.hdr.id;
-        op->reply.hdr.opcode = op->req.hdr.opcode;
-        op->reply.hdr.retval = -EPIPE;
-        op->callback(op);
-    }
-    else
-    {
-        delete op;
-    }
-}
-
-void osd_t::stop_client(int peer_fd)
-{
-    auto it = clients.find(peer_fd);
-    if (it == clients.end())
-    {
-        return;
-    }
-    auto & cl = it->second;
-    if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, peer_fd, NULL) < 0)
-    {
-        throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
-    }
-    if (cl.osd_num)
-    {
-        // Cancel outbound operations
-        cancel_osd_ops(cl);
-        osd_peer_fds.erase(cl.osd_num);
-        repeer_pgs(cl.osd_num, false);
-        peering_state |= OSD_PEERING_PEERS;
-    }
-    if (cl.read_op)
-    {
-        delete cl.read_op;
-    }
-    for (auto rit = read_ready_clients.begin(); rit != read_ready_clients.end(); rit++)
-    {
-        if (*rit == peer_fd)
-        {
-            read_ready_clients.erase(rit);
-            break;
-        }
-    }
-    for (auto wit = write_ready_clients.begin(); wit != write_ready_clients.end(); wit++)
-    {
-        if (*wit == peer_fd)
-        {
-            write_ready_clients.erase(wit);
-            break;
-        }
-    }
-    clients.erase(it);
-    close(peer_fd);
-}
-
 void osd_t::exec_op(osd_op_t *cur_op)
 {
     clock_gettime(CLOCK_REALTIME, &cur_op->tv_begin);
@@ -362,23 +182,36 @@ void osd_t::exec_op(osd_op_t *cur_op)
         delete cur_op;
         return;
     }
-    cur_op->send_list.push_back(cur_op->reply.buf, OSD_PACKET_SIZE);
+    inflight_ops++;
     if (cur_op->req.hdr.magic != SECONDARY_OSD_OP_MAGIC ||
         cur_op->req.hdr.opcode < OSD_OP_MIN || cur_op->req.hdr.opcode > OSD_OP_MAX ||
-        (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_READ || cur_op->req.hdr.opcode == OSD_OP_SECONDARY_WRITE) &&
-        (cur_op->req.sec_rw.len > OSD_RW_MAX || cur_op->req.sec_rw.len % OSD_RW_ALIGN || cur_op->req.sec_rw.offset % OSD_RW_ALIGN) ||
-        (cur_op->req.hdr.opcode == OSD_OP_READ || cur_op->req.hdr.opcode == OSD_OP_WRITE) &&
-        (cur_op->req.rw.len > OSD_RW_MAX || cur_op->req.rw.len % OSD_RW_ALIGN || cur_op->req.rw.offset % OSD_RW_ALIGN))
+        ((cur_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+            cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+            cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE) &&
+            (cur_op->req.sec_rw.len > OSD_RW_MAX ||
+            cur_op->req.sec_rw.len % bs_disk_alignment ||
+            cur_op->req.sec_rw.offset % bs_disk_alignment)) ||
+        ((cur_op->req.hdr.opcode == OSD_OP_READ ||
+            cur_op->req.hdr.opcode == OSD_OP_WRITE ||
+            cur_op->req.hdr.opcode == OSD_OP_DELETE) &&
+            (cur_op->req.rw.len > OSD_RW_MAX ||
+            cur_op->req.rw.len % bs_disk_alignment ||
+            cur_op->req.rw.offset % bs_disk_alignment)))
     {
         // Bad command
-        cur_op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
-        cur_op->reply.hdr.id = cur_op->req.hdr.id;
-        cur_op->reply.hdr.opcode = cur_op->req.hdr.opcode;
-        cur_op->reply.hdr.retval = -EINVAL;
-        outbox_push(this->clients[cur_op->peer_fd], cur_op);
+        finish_op(cur_op, -EINVAL);
+        return;
+    }
+    if (readonly &&
+        cur_op->req.hdr.opcode != OSD_OP_SEC_READ &&
+        cur_op->req.hdr.opcode != OSD_OP_SEC_LIST &&
+        cur_op->req.hdr.opcode != OSD_OP_READ &&
+        cur_op->req.hdr.opcode != OSD_OP_SHOW_CONFIG)
+    {
+        // Readonly mode
+        finish_op(cur_op, -EROFS);
         return;
     }
-    inflight_ops++;
     if (cur_op->req.hdr.opcode == OSD_OP_TEST_SYNC_STAB_ALL)
     {
         exec_sync_stab_all(cur_op);
@@ -399,8 +232,84 @@ void osd_t::exec_op(osd_op_t *cur_op)
     {
         continue_primary_sync(cur_op);
     }
+    else if (cur_op->req.hdr.opcode == OSD_OP_DELETE)
+    {
+        continue_primary_del(cur_op);
+    }
     else
     {
         exec_secondary(cur_op);
     }
 }
+
+void osd_t::reset_stats()
+{
+    c_cli.stats = { 0 };
+    prev_stats = { 0 };
+    memset(recovery_stat_count, 0, sizeof(recovery_stat_count));
+    memset(recovery_stat_bytes, 0, sizeof(recovery_stat_bytes));
+}
+
+void osd_t::print_stats()
+{
+    for (int i = 0; i <= OSD_OP_MAX; i++)
+    {
+        if (c_cli.stats.op_stat_count[i] != prev_stats.op_stat_count[i])
+        {
+            uint64_t avg = (c_cli.stats.op_stat_sum[i] - prev_stats.op_stat_sum[i])/(c_cli.stats.op_stat_count[i] - prev_stats.op_stat_count[i]);
+            uint64_t bw = (c_cli.stats.op_stat_bytes[i] - prev_stats.op_stat_bytes[i]) / print_stats_interval;
+            if (c_cli.stats.op_stat_bytes[i] != 0)
+            {
+                printf(
+                    "[OSD %lu] avg latency for op %d (%s): %lu us, B/W: %.2f %s\n", osd_num, i, osd_op_names[i], avg,
+                    (bw > 1024*1024*1024 ? bw/1024.0/1024/1024 : (bw > 1024*1024 ? bw/1024.0/1024 : bw/1024.0)),
+                    (bw > 1024*1024*1024 ? "GB/s" : (bw > 1024*1024 ? "MB/s" : "KB/s"))
+                );
+            }
+            else
+            {
+                printf("[OSD %lu] avg latency for op %d (%s): %lu us\n", osd_num, i, osd_op_names[i], avg);
+            }
+            prev_stats.op_stat_count[i] = c_cli.stats.op_stat_count[i];
+            prev_stats.op_stat_sum[i] = c_cli.stats.op_stat_sum[i];
+            prev_stats.op_stat_bytes[i] = c_cli.stats.op_stat_bytes[i];
+        }
+    }
+    for (int i = 0; i <= OSD_OP_MAX; i++)
+    {
+        if (c_cli.stats.subop_stat_count[i] != prev_stats.subop_stat_count[i])
+        {
+            uint64_t avg = (c_cli.stats.subop_stat_sum[i] - prev_stats.subop_stat_sum[i])/(c_cli.stats.subop_stat_count[i] - prev_stats.subop_stat_count[i]);
+            printf("[OSD %lu] avg latency for subop %d (%s): %ld us\n", osd_num, i, osd_op_names[i], avg);
+            prev_stats.subop_stat_count[i] = c_cli.stats.subop_stat_count[i];
+            prev_stats.subop_stat_sum[i] = c_cli.stats.subop_stat_sum[i];
+        }
+    }
+    for (int i = 0; i < 2; i++)
+    {
+        if (recovery_stat_count[0][i] != recovery_stat_count[1][i])
+        {
+            uint64_t bw = (recovery_stat_bytes[0][i] - recovery_stat_bytes[1][i]) / print_stats_interval;
+            printf(
+                "[OSD %lu] %s recovery: %.1f op/s, B/W: %.2f %s\n", osd_num, recovery_stat_names[i],
+                (recovery_stat_count[0][i] - recovery_stat_count[1][i]) * 1.0 / print_stats_interval,
+                (bw > 1024*1024*1024 ? bw/1024.0/1024/1024 : (bw > 1024*1024 ? bw/1024.0/1024 : bw/1024.0)),
+                (bw > 1024*1024*1024 ? "GB/s" : (bw > 1024*1024 ? "MB/s" : "KB/s"))
+            );
+            recovery_stat_count[1][i] = recovery_stat_count[0][i];
+            recovery_stat_bytes[1][i] = recovery_stat_bytes[0][i];
+        }
+    }
+    if (incomplete_objects > 0)
+    {
+        printf("[OSD %lu] %lu object(s) incomplete\n", osd_num, incomplete_objects);
+    }
+    if (degraded_objects > 0)
+    {
+        printf("[OSD %lu] %lu object(s) degraded\n", osd_num, degraded_objects);
+    }
+    if (misplaced_objects > 0)
+    {
+        printf("[OSD %lu] %lu object(s) misplaced\n", osd_num, misplaced_objects);
+    }
+}

osd.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include <sys/types.h>
@@ -15,171 +18,86 @@
 
 #include "blockstore.h"
 #include "ringloop.h"
-#include "timerfd_interval.h"
-#include "osd_ops.h"
+#include "timerfd_manager.h"
+#include "epoll_manager.h"
 #include "osd_peering_pg.h"
+#include "messenger.h"
+#include "etcd_state_client.h"
 
-#include "sparsepp/sparsepp/spp.h"
+#define OSD_LOADING_PGS 0x01
+#define OSD_PEERING_PGS 0x04
+#define OSD_FLUSHING_PGS 0x08
+#define OSD_RECOVERING 0x10
 
-#define OSD_OP_IN 0
-#define OSD_OP_OUT 1
+#define IMMEDIATE_NONE 0
+#define IMMEDIATE_SMALL 1
+#define IMMEDIATE_ALL 2
 
-#define CL_READ_OP 1
-#define CL_READ_DATA 2
-#define CL_READ_REPLY_DATA 3
-#define CL_WRITE_READY 1
-#define CL_WRITE_REPLY 2
-#define MAX_EPOLL_EVENTS 64
-#define OSD_OP_INLINE_BUF_COUNT 16
-
-#define PEER_CONNECTING 1
-#define PEER_CONNECTED 2
-#define OSD_PEERING_PEERS 1
-#define OSD_PEERING_PGS 2
+#define MAX_AUTOSYNC_INTERVAL 3600
+#define DEFAULT_AUTOSYNC_INTERVAL 5
+#define MAX_RECOVERY_QUEUE 2048
+#define DEFAULT_RECOVERY_QUEUE 4
 
 //#define OSD_STUB
 
-struct osd_op_buf_list_t
-{
-    int count = 0, alloc = 0, sent = 0;
-    iovec *buf = NULL;
-    iovec inline_buf[OSD_OP_INLINE_BUF_COUNT];
-
-    ~osd_op_buf_list_t()
-    {
-        if (buf && buf != inline_buf)
-        {
-            free(buf);
-        }
-    }
-
-    inline iovec* get_iovec()
-    {
-        return (buf ? buf : inline_buf) + sent;
-    }
-
-    inline int get_size()
-    {
-        return count - sent;
-    }
-
-    inline void push_back(void *nbuf, size_t len)
-    {
-        if (count >= alloc)
-        {
-            if (!alloc)
-            {
-                alloc = OSD_OP_INLINE_BUF_COUNT;
-                buf = inline_buf;
-            }
-            else if (buf == inline_buf)
-            {
-                int old = alloc;
-                alloc = ((alloc/16)*16 + 1);
-                buf = (iovec*)malloc(sizeof(iovec) * alloc);
-                memcpy(buf, inline_buf, sizeof(iovec)*old);
-            }
-            else
-            {
-                alloc = ((alloc/16)*16 + 1);
-                buf = (iovec*)realloc(buf, sizeof(iovec) * alloc);
-            }
-        }
-        buf[count++] = { .iov_base = nbuf, .iov_len = len };
-    }
-};
-
-struct osd_primary_op_data_t;
-
-struct osd_op_t
-{
-    timespec tv_begin;
-    timespec tv_send;
-    int op_type = OSD_OP_IN;
-    int peer_fd;
-    osd_any_op_t req;
-    osd_any_reply_t reply;
-    blockstore_op_t *bs_op = NULL;
-    void *buf = NULL;
-    void *rmw_buf = NULL;
-    osd_primary_op_data_t* op_data = NULL;
-    std::function<void(osd_op_t*)> callback;
-
-    osd_op_buf_list_t send_list;
-
-    ~osd_op_t();
-};
-
-struct osd_peer_def_t
-{
-    osd_num_t osd_num = 0;
-    std::string addr;
-    int port = 0;
-    time_t last_connect_attempt = 0;
-};
-
-struct osd_client_t
-{
-    sockaddr_in peer_addr;
-    int peer_port;
-    int peer_fd, peer_fd_index;
-    int peer_state;
-    std::function<void(osd_num_t, int)> connect_callback;
-    osd_num_t osd_num = 0;
-
-    // Read state
-    int read_ready = 0;
-    osd_op_t *read_op = NULL;
-    int read_reply_id = 0;
-    iovec read_iov;
-    msghdr read_msg;
-    void *read_buf = NULL;
-    int read_remaining = 0;
-    int read_state = 0;
-
-    // Outbound operations sent to this client (which is probably an OSD peer)
-    std::map<int, osd_op_t*> sent_ops;
-
-    // Outbound messages (replies or requests)
-    std::deque<osd_op_t*> outbox;
-
-    // PGs dirtied by this client's primary-writes
-    std::set<pg_num_t> dirty_pgs;
-
-    // Write state
-    osd_op_t *write_op = NULL;
-    msghdr write_msg;
-    int write_state = 0;
-};
-
-struct osd_rmw_stripe_t;
-
 struct osd_object_id_t
 {
     osd_num_t osd_num;
     object_id oid;
 };
 
+struct osd_recovery_op_t
+{
+    int st = 0;
+    bool degraded = false;
+    object_id oid = { 0 };
+    osd_op_t *osd_op = NULL;
+};
+
 class osd_t
 {
     // config
 
+    blockstore_config_t config;
+    int etcd_report_interval = 30;
+
+    bool readonly = false;
     osd_num_t osd_num = 1; // OSD numbers start with 1
     bool run_primary = false;
-    std::vector<osd_peer_def_t> peers;
-    blockstore_config_t config;
     std::string bind_address;
     int bind_port, listen_backlog;
+    // FIXME: Implement client queue depth limit
     int client_queue_depth = 128;
     bool allow_test_ops = true;
+    int print_stats_interval = 3;
+    int immediate_commit = IMMEDIATE_NONE;
+    int autosync_interval = DEFAULT_AUTOSYNC_INTERVAL; // sync every 5 seconds
+    int recovery_queue_depth = DEFAULT_RECOVERY_QUEUE;
+    int log_level = 0;
 
-    // peer OSDs
+    // cluster state
 
-    std::map<uint64_t, int> osd_peer_fds;
-    std::vector<pg_t> pgs;
+    etcd_state_client_t st_cli;
+    osd_messenger_t c_cli;
+    int etcd_failed_attempts = 0;
+    std::string etcd_lease_id;
+    json11::Json self_state;
+    bool loading_peer_config = false;
+    std::set<pool_pg_num_t> pg_state_dirty;
+    bool pg_config_applied = false;
+    bool etcd_reporting_pg_state = false;
+    bool etcd_reporting_stats = false;
+
+    // peers and PGs
+
+    std::map<pool_id_t, pg_num_t> pg_counts;
+    std::map<pool_pg_num_t, pg_t> pgs;
+    std::set<pool_pg_num_t> dirty_pgs;
+    std::set<osd_num_t> dirty_osds;
+    uint64_t misplaced_objects = 0, degraded_objects = 0, incomplete_objects = 0;
     int peering_state = 0;
-    unsigned pg_count = 0;
-    uint64_t next_subop_id = 1;
+    std::map<object_id, osd_recovery_op_t> recovery_ops;
+    osd_op_t *autosync_op = NULL;
 
     // Unstable writes
     std::map<osd_object_id_t, uint64_t> unstable_writes;
@@ -191,53 +109,69 @@ class osd_t
     int inflight_ops = 0;
     blockstore_t *bs;
     uint32_t bs_block_size, bs_disk_alignment;
-    uint64_t parity_block_size = 4*1024*1024; // 4 MB by default
     ring_loop_t *ringloop;
-    timerfd_interval *tick_tfd;
+    timerfd_manager_t *tfd = NULL;
+    epoll_manager_t *epmgr = NULL;
 
-    int wait_state = 0;
-    int epoll_fd = 0, epoll_fd_index = -1;
+    int listening_port = 0;
     int listen_fd = 0;
     ring_consumer_t consumer;
 
-    std::unordered_map<int,osd_client_t> clients;
-    std::vector<int> read_ready_clients;
-    std::vector<int> write_ready_clients;
-    uint64_t op_stat_sum[OSD_OP_MAX+1] = { 0 };
-    uint64_t op_stat_count[OSD_OP_MAX+1] = { 0 };
-    uint64_t subop_stat_sum[OSD_OP_MAX+1] = { 0 };
-    uint64_t subop_stat_count[OSD_OP_MAX+1] = { 0 };
-    uint64_t send_stat_sum = 0;
-    uint64_t send_stat_count = 0;
+    // op statistics
+    osd_op_stats_t prev_stats;
+    const char* recovery_stat_names[2] = { "degraded", "misplaced" };
+    uint64_t recovery_stat_count[2][2] = { 0 };
+    uint64_t recovery_stat_bytes[2][2] = { 0 };
 
-    // methods
+    // cluster connection
+    void parse_config(blockstore_config_t & config);
+    void init_cluster();
+    void on_change_osd_state_hook(osd_num_t peer_osd);
+    void on_change_pg_history_hook(pool_id_t pool_id, pg_num_t pg_num);
+    void on_change_etcd_state_hook(json11::Json::object & changes);
+    void on_load_config_hook(json11::Json::object & changes);
+    json11::Json on_load_pgs_checks_hook();
+    void on_load_pgs_hook(bool success);
+    void bind_socket();
+    void acquire_lease();
+    json11::Json get_osd_state();
+    void create_osd_state();
+    void renew_lease();
+    void print_stats();
+    void reset_stats();
+    json11::Json get_statistics();
+    void report_statistics();
+    void report_pg_state(pg_t & pg);
+    void report_pg_states();
+    void apply_pg_count();
+    void apply_pg_config();
 
     // event loop, socket read/write
     void loop();
-    void handle_epoll_events();
-    void read_requests();
-    void handle_read(ring_data_t *data, int peer_fd);
-    void handle_op_hdr(osd_client_t *cl);
-    void handle_reply_hdr(osd_client_t *cl);
-    bool try_send(osd_client_t & cl);
-    void send_replies();
-    void handle_send(ring_data_t *data, int peer_fd);
-    void outbox_push(osd_client_t & cl, osd_op_t *op);
 
     // peer handling (primary OSD logic)
-    void connect_peer(osd_num_t osd_num, const char *peer_host, int peer_port, std::function<void(osd_num_t, int)> callback);
-    void handle_connect_result(int peer_fd);
-    void cancel_osd_ops(osd_client_t & cl);
-    void cancel_op(osd_op_t *op);
-    void stop_client(int peer_fd);
-    osd_peer_def_t parse_peer(std::string peer);
-    void init_primary();
+    void parse_test_peer(std::string peer);
     void handle_peers();
-    void repeer_pgs(osd_num_t osd_num, bool is_connected);
-    void start_pg_peering(int i);
+    void repeer_pgs(osd_num_t osd_num);
+    void start_pg_peering(pg_t & pg);
+    void submit_sync_and_list_subop(osd_num_t role_osd, pg_peering_state_t *ps);
+    void submit_list_subop(osd_num_t role_osd, pg_peering_state_t *ps);
+    void discard_list_subop(osd_op_t *list_op);
+    bool stop_pg(pg_t & pg);
+    void finish_stop_pg(pg_t & pg);
+
+    // flushing, recovery and backfill
+    void submit_pg_flush_ops(pg_t & pg);
+    void handle_flush_op(bool rollback, pool_id_t pool_id, pg_num_t pg_num, pg_flush_batch_t *fb, osd_num_t peer_osd, int retval);
+    void submit_flush_op(pool_id_t pool_id, pg_num_t pg_num, pg_flush_batch_t *fb, bool rollback, osd_num_t peer_osd, int count, obj_ver_id *data);
+    bool pick_next_recovery(osd_recovery_op_t &op);
+    void submit_recovery_op(osd_recovery_op_t *op);
+    bool continue_recovery();
+    pg_osd_set_state_t* change_osd_set(pg_osd_set_state_t *st, pg_t *pg);
 
     // op execution
     void exec_op(osd_op_t *cur_op);
+    void finish_op(osd_op_t *cur_op, int retval);
 
     // secondary ops
     void exec_sync_stab_all(osd_op_t *cur_op);
@@ -246,18 +180,37 @@ class osd_t
     void secondary_op_callback(osd_op_t *cur_op);
 
     // primary ops
+    void autosync();
     bool prepare_primary_rw(osd_op_t *cur_op);
     void continue_primary_read(osd_op_t *cur_op);
     void continue_primary_write(osd_op_t *cur_op);
+    void cancel_primary_write(osd_op_t *cur_op);
     void continue_primary_sync(osd_op_t *cur_op);
-    void finish_primary_op(osd_op_t *cur_op, int retval);
-    void handle_primary_subop(osd_op_t *cur_op, int ok, uint64_t version);
-    void submit_primary_subops(int submit_type, int read_pg_size, const uint64_t* osd_set, osd_op_t *cur_op);
+    void continue_primary_del(osd_op_t *cur_op);
+    bool check_write_queue(osd_op_t *cur_op, pg_t & pg);
+    void remove_object_from_state(object_id & oid, pg_osd_set_state_t *object_state, pg_t &pg);
+    bool remember_unstable_write(osd_op_t *cur_op, pg_t & pg, pg_osd_set_t & loc_set, int base_state);
+    void handle_primary_subop(osd_op_t *subop, osd_op_t *cur_op);
+    void handle_primary_bs_subop(osd_op_t *subop);
+    void add_bs_subop_stats(osd_op_t *subop);
+    void pg_cancel_write_queue(pg_t & pg, osd_op_t *first_op, object_id oid, int retval);
+    void submit_primary_subops(int submit_type, uint64_t op_version, int pg_size, const uint64_t* osd_set, osd_op_t *cur_op);
+    void submit_primary_del_subops(osd_op_t *cur_op, uint64_t *cur_set, uint64_t set_size, pg_osd_set_t & loc_set);
     void submit_primary_sync_subops(osd_op_t *cur_op);
     void submit_primary_stab_subops(osd_op_t *cur_op);
+
+    inline pg_num_t map_to_pg(object_id oid, uint64_t pg_stripe_size)
+    {
+        uint64_t pg_count = pg_counts[INODE_POOL(oid.inode)];
+        if (!pg_count)
+            pg_count = 1;
+        return (oid.inode + oid.stripe / pg_stripe_size) % pg_count + 1;
+    }
+
 public:
     osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringloop);
     ~osd_t();
+    void force_stop(int exitcode);
     bool shutdown();
 };
 

osd_client.cpp

@@ -1,40 +0,0 @@
-void slice()
-{
-    // Slice the request into blockstore requests to individual objects
-    // Primary OSD still operates individual stripes, except they're twice the size of the blockstore's stripe.
-    std::vector read_parts;
-    int block = bs->get_block_size();
-    uint64_t stripe1 = cur_op->req.rw.offset / block / 2;
-    uint64_t stripe2 = (cur_op->req.rw.offset + cur_op->req.rw.len + block*2 - 1) / block / 2 - 1;
-    for (uint64_t s = stripe1; s <= stripe2; s++)
-    {
-        uint64_t start = s == stripe1 ? cur_op->req.rw.offset - stripe1*block*2 : 0;
-        uint64_t end = s == stripe2 ? cur_op->req.rw.offset + cur_op->req.rw.len - stripe2*block*2 : block*2;
-        if (start < block)
-        {
-            read_parts.push_back({
-                .role = 1,
-                .oid = {
-                    .inode = cur_op->req.rw.inode,
-                    .stripe = (s << STRIPE_ROLE_BITS) | 1,
-                },
-                .version = UINT64_MAX,
-                .offset = start,
-                .len = (block < end ? block : end) - start,
-            });
-        }
-        if (end > block)
-        {
-            read_parts.push_back({
-                .role = 2,
-                .oid = {
-                    .inode = cur_op->req.rw.inode,
-                    .stripe = (s << STRIPE_ROLE_BITS) | 2,
-                },
-                .version = UINT64_MAX,
-                .offset = (start > block ? start-block : 0),
-                .len = end - (start > block ? start-block : 0),
-            });
-        }
-    }
-}

osd_cluster.cpp

@@ -0,0 +1,791 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include "osd.h"
+#include "base64.h"
+#include "etcd_state_client.h"
+
+// Startup sequence:
+//   Start etcd watcher -> Load global OSD configuration -> Bind socket -> Acquire lease -> Report&lock OSD state
+//   -> Load PG config -> Report&lock PG states -> Load peers -> Connect to peers -> Peer PGs
+// Event handling
+//   Wait for PG changes -> Start/Stop PGs when requested
+//   Peer connection is lost -> Reload connection data -> Try to reconnect
+void osd_t::init_cluster()
+{
+    if (!st_cli.etcd_addresses.size())
+    {
+        if (run_primary)
+        {
+            // Test version of clustering code with 1 pool, 1 PG and 2 peers
+            // Example: peers = 2:127.0.0.1:11204,3:127.0.0.1:11205
+            std::string peerstr = config["peers"];
+            while (peerstr.size())
+            {
+                int pos = peerstr.find(',');
+                parse_test_peer(pos < 0 ? peerstr : peerstr.substr(0, pos));
+                peerstr = pos < 0 ? std::string("") : peerstr.substr(pos+1);
+            }
+            if (st_cli.peer_states.size() < 2)
+            {
+                throw std::runtime_error("run_primary requires at least 2 peers");
+            }
+            pgs[{ 1, 1 }] = (pg_t){
+                .state = PG_PEERING,
+                .pg_cursize = 0,
+                .pool_id = 1,
+                .pg_num = 1,
+                .target_set = { 1, 2, 3 },
+                .cur_set = { 0, 0, 0 },
+            };
+            report_pg_state(pgs[{ 1, 1 }]);
+            pg_counts[1] = 1;
+        }
+        bind_socket();
+    }
+    else
+    {
+        st_cli.tfd = tfd;
+        st_cli.log_level = log_level;
+        st_cli.on_change_osd_state_hook = [this](osd_num_t peer_osd) { on_change_osd_state_hook(peer_osd); };
+        st_cli.on_change_pg_history_hook = [this](pool_id_t pool_id, pg_num_t pg_num) { on_change_pg_history_hook(pool_id, pg_num); };
+        st_cli.on_change_hook = [this](json11::Json::object & changes) { on_change_etcd_state_hook(changes); };
+        st_cli.on_load_config_hook = [this](json11::Json::object & cfg) { on_load_config_hook(cfg); };
+        st_cli.load_pgs_checks_hook = [this]() { return on_load_pgs_checks_hook(); };
+        st_cli.on_load_pgs_hook = [this](bool success) { on_load_pgs_hook(success); };
+        peering_state = OSD_LOADING_PGS;
+        st_cli.load_global_config();
+    }
+    if (run_primary && autosync_interval > 0)
+    {
+        this->tfd->set_timer(autosync_interval*1000, true, [this](int timer_id)
+        {
+            autosync();
+        });
+    }
+}
+
+void osd_t::parse_test_peer(std::string peer)
+{
+    // OSD_NUM:IP:PORT
+    int pos1 = peer.find(':');
+    int pos2 = peer.find(':', pos1+1);
+    if (pos1 < 0 || pos2 < 0)
+        throw new std::runtime_error("OSD peer string must be in the form OSD_NUM:IP:PORT");
+    std::string addr = peer.substr(pos1+1, pos2-pos1-1);
+    std::string osd_num_str = peer.substr(0, pos1);
+    std::string port_str = peer.substr(pos2+1);
+    osd_num_t peer_osd = strtoull(osd_num_str.c_str(), NULL, 10);
+    if (!peer_osd)
+        throw new std::runtime_error("Could not parse OSD peer osd_num");
+    else if (st_cli.peer_states.find(peer_osd) != st_cli.peer_states.end())
+        throw std::runtime_error("Same osd number "+std::to_string(peer_osd)+" specified twice in peers");
+    int port = strtoull(port_str.c_str(), NULL, 10);
+    if (!port)
+        throw new std::runtime_error("Could not parse OSD peer port");
+    st_cli.peer_states[peer_osd] = json11::Json::object {
+        { "state", "up" },
+        { "addresses", json11::Json::array { addr } },
+        { "port", port },
+    };
+    c_cli.connect_peer(peer_osd, st_cli.peer_states[peer_osd]);
+}
+
+json11::Json osd_t::get_osd_state()
+{
+    std::vector<char> hostname;
+    hostname.resize(1024);
+    while (gethostname(hostname.data(), hostname.size()) < 0 && errno == ENAMETOOLONG)
+        hostname.resize(hostname.size()+1024);
+    hostname.resize(strnlen(hostname.data(), hostname.size()));
+    json11::Json::object st;
+    st["state"] = "up";
+    if (bind_address != "0.0.0.0")
+        st["addresses"] = json11::Json::array { bind_address };
+    else
+        st["addresses"] = getifaddr_list();
+    st["host"] = std::string(hostname.data(), hostname.size());
+    st["port"] = listening_port;
+    st["primary_enabled"] = run_primary;
+    st["blockstore_enabled"] = bs ? true : false;
+    return st;
+}
+
+json11::Json osd_t::get_statistics()
+{
+    json11::Json::object st;
+    timespec ts;
+    clock_gettime(CLOCK_REALTIME, &ts);
+    char time_str[50] = { 0 };
+    sprintf(time_str, "%ld.%03ld", ts.tv_sec, ts.tv_nsec/1000000);
+    st["time"] = time_str;
+    st["blockstore_ready"] = bs->is_started();
+    if (bs)
+    {
+        st["size"] = bs->get_block_count() * bs->get_block_size();
+        st["free"] = bs->get_free_block_count() * bs->get_block_size();
+    }
+    st["host"] = self_state["host"];
+    json11::Json::object op_stats, subop_stats;
+    for (int i = 0; i <= OSD_OP_MAX; i++)
+    {
+        op_stats[osd_op_names[i]] = json11::Json::object {
+            { "count", c_cli.stats.op_stat_count[i] },
+            { "usec", c_cli.stats.op_stat_sum[i] },
+            { "bytes", c_cli.stats.op_stat_bytes[i] },
+        };
+    }
+    for (int i = 0; i <= OSD_OP_MAX; i++)
+    {
+        subop_stats[osd_op_names[i]] = json11::Json::object {
+            { "count", c_cli.stats.subop_stat_count[i] },
+            { "usec", c_cli.stats.subop_stat_sum[i] },
+        };
+    }
+    st["op_stats"] = op_stats;
+    st["subop_stats"] = subop_stats;
+    st["recovery_stats"] = json11::Json::object {
+        { recovery_stat_names[0], json11::Json::object {
+            { "count", recovery_stat_count[0][0] },
+            { "bytes", recovery_stat_bytes[0][0] },
+        } },
+        { recovery_stat_names[1], json11::Json::object {
+            { "count", recovery_stat_count[0][1] },
+            { "bytes", recovery_stat_bytes[0][1] },
+        } },
+    };
+    return st;
+}
+
+void osd_t::report_statistics()
+{
+    if (etcd_reporting_stats)
+    {
+        return;
+    }
+    etcd_reporting_stats = true;
+    json11::Json::array txn = { json11::Json::object {
+        { "request_put", json11::Json::object {
+            { "key", base64_encode(st_cli.etcd_prefix+"/osd/stats/"+std::to_string(osd_num)) },
+            { "value", base64_encode(get_statistics().dump()) },
+        } }
+    } };
+    for (auto & p: pgs)
+    {
+        auto & pg = p.second;
+        if (pg.state & (PG_OFFLINE | PG_STARTING))
+        {
+            // Don't report statistics for offline PGs
+            continue;
+        }
+        json11::Json::object pg_stats;
+        pg_stats["object_count"] = pg.total_count;
+        pg_stats["clean_count"] = pg.clean_count;
+        pg_stats["misplaced_count"] = pg.misplaced_objects.size();
+        pg_stats["degraded_count"] = pg.degraded_objects.size();
+        pg_stats["incomplete_count"] = pg.incomplete_objects.size();
+        pg_stats["write_osd_set"] = pg.cur_set;
+        txn.push_back(json11::Json::object {
+            { "request_put", json11::Json::object {
+                { "key", base64_encode(st_cli.etcd_prefix+"/pg/stats/"+std::to_string(pg.pool_id)+"/"+std::to_string(pg.pg_num)) },
+                { "value", base64_encode(json11::Json(pg_stats).dump()) },
+            } }
+        });
+    }
+    st_cli.etcd_txn(json11::Json::object { { "success", txn } }, ETCD_SLOW_TIMEOUT, [this](std::string err, json11::Json res)
+    {
+        etcd_reporting_stats = false;
+        if (err != "")
+        {
+            printf("[OSD %lu] Error reporting state to etcd: %s\n", this->osd_num, err.c_str());
+            // Retry indefinitely
+            tfd->set_timer(ETCD_SLOW_TIMEOUT, false, [this](int timer_id)
+            {
+                report_statistics();
+            });
+        }
+        else if (res["error"].string_value() != "")
+        {
+            printf("[OSD %lu] Error reporting state to etcd: %s\n", this->osd_num, res["error"].string_value().c_str());
+            force_stop(1);
+        }
+    });
+}
+
+void osd_t::on_change_osd_state_hook(osd_num_t peer_osd)
+{
+    if (c_cli.wanted_peers.find(peer_osd) != c_cli.wanted_peers.end())
+    {
+        c_cli.connect_peer(peer_osd, st_cli.peer_states[peer_osd]);
+    }
+}
+
+void osd_t::on_change_etcd_state_hook(json11::Json::object & changes)
+{
+    // FIXME apply config changes in runtime (maybe, some)
+    apply_pg_count();
+    apply_pg_config();
+}
+
+void osd_t::on_change_pg_history_hook(pool_id_t pool_id, pg_num_t pg_num)
+{
+    auto pg_it = pgs.find({
+        .pool_id = pool_id,
+        .pg_num = pg_num,
+    });
+    if (pg_it != pgs.end() && pg_it->second.epoch > pg_it->second.reported_epoch &&
+        st_cli.pool_config[pool_id].pg_config[pg_num].epoch >= pg_it->second.epoch)
+    {
+        pg_it->second.reported_epoch = st_cli.pool_config[pool_id].pg_config[pg_num].epoch;
+        object_id oid = { 0 };
+        bool first = true;
+        for (auto op: pg_it->second.write_queue)
+        {
+            if (first || oid != op.first)
+            {
+                oid = op.first;
+                first = false;
+                continue_primary_write(op.second);
+            }
+        }
+    }
+}
+
+void osd_t::on_load_config_hook(json11::Json::object & global_config)
+{
+    blockstore_config_t osd_config = this->config;
+    for (auto & cfg_var: global_config)
+    {
+        if (this->config.find(cfg_var.first) == this->config.end())
+        {
+            if (cfg_var.second.is_string())
+            {
+                osd_config[cfg_var.first] = cfg_var.second.string_value();
+            }
+            else
+            {
+                osd_config[cfg_var.first] = cfg_var.second.dump();
+            }
+        }
+    }
+    parse_config(osd_config);
+    bind_socket();
+    st_cli.start_etcd_watcher();
+    acquire_lease();
+}
+
+// Acquire lease
+void osd_t::acquire_lease()
+{
+    // Maximum lease TTL is (report interval) + retries * (timeout + repeat interval)
+    st_cli.etcd_call("/lease/grant", json11::Json::object {
+        { "TTL", etcd_report_interval+(MAX_ETCD_ATTEMPTS*(2*ETCD_QUICK_TIMEOUT)+999)/1000 }
+    }, ETCD_QUICK_TIMEOUT, [this](std::string err, json11::Json data)
+    {
+        if (err != "" || data["ID"].string_value() == "")
+        {
+            printf("Error acquiring a lease from etcd: %s\n", err.c_str());
+            tfd->set_timer(ETCD_QUICK_TIMEOUT, false, [this](int timer_id)
+            {
+                acquire_lease();
+            });
+            return;
+        }
+        etcd_lease_id = data["ID"].string_value();
+        create_osd_state();
+    });
+    printf("[OSD %lu] reporting to etcd at %s every %d seconds\n", this->osd_num, config["etcd_address"].c_str(), etcd_report_interval);
+    tfd->set_timer(etcd_report_interval*1000, true, [this](int timer_id)
+    {
+        renew_lease();
+    });
+}
+
+// Report "up" state once, then keep it alive using the lease
+// Do it first to allow "monitors" check it when moving PGs
+void osd_t::create_osd_state()
+{
+    std::string state_key = base64_encode(st_cli.etcd_prefix+"/osd/state/"+std::to_string(osd_num));
+    self_state = get_osd_state();
+    st_cli.etcd_txn(json11::Json::object {
+        // Check that the state key does not exist
+        { "compare", json11::Json::array {
+            json11::Json::object {
+                { "target", "CREATE" },
+                { "create_revision", 0 },
+                { "key", state_key },
+            }
+        } },
+        { "success", json11::Json::array {
+            json11::Json::object {
+                { "request_put", json11::Json::object {
+                    { "key", state_key },
+                    { "value", base64_encode(self_state.dump()) },
+                    { "lease", etcd_lease_id },
+                } }
+            },
+        } },
+        { "failure", json11::Json::array {
+            json11::Json::object {
+                { "request_range", json11::Json::object {
+                    { "key", state_key },
+                } }
+            },
+        } },
+    }, ETCD_QUICK_TIMEOUT, [this](std::string err, json11::Json data)
+    {
+        if (err != "")
+        {
+            etcd_failed_attempts++;
+            printf("Error creating OSD state key: %s\n", err.c_str());
+            if (etcd_failed_attempts > MAX_ETCD_ATTEMPTS)
+            {
+                // Die
+                throw std::runtime_error("Cluster connection failed");
+            }
+            // Retry
+            tfd->set_timer(ETCD_QUICK_TIMEOUT, false, [this](int timer_id)
+            {
+                create_osd_state();
+            });
+            return;
+        }
+        if (!data["succeeded"].bool_value())
+        {
+            // OSD is already up
+            auto kv = st_cli.parse_etcd_kv(data["responses"][0]["response_range"]["kvs"][0]);
+            printf("Key %s already exists in etcd, OSD %lu is still up\n", kv.key.c_str(), this->osd_num);
+            int64_t port = kv.value["port"].int64_value();
+            for (auto & addr: kv.value["addresses"].array_items())
+            {
+                printf("  listening at: %s:%ld\n", addr.string_value().c_str(), port);
+            }
+            force_stop(0);
+            return;
+        }
+        if (run_primary)
+        {
+            st_cli.load_pgs();
+        }
+    });
+}
+
+// Renew lease
+void osd_t::renew_lease()
+{
+    st_cli.etcd_call("/lease/keepalive", json11::Json::object {
+        { "ID", etcd_lease_id }
+    }, ETCD_QUICK_TIMEOUT, [this](std::string err, json11::Json data)
+    {
+        if (err == "" && data["result"]["TTL"].string_value() == "")
+        {
+            // Die
+            throw std::runtime_error("etcd lease has expired");
+        }
+        if (err != "")
+        {
+            etcd_failed_attempts++;
+            printf("Error renewing etcd lease: %s\n", err.c_str());
+            if (etcd_failed_attempts > MAX_ETCD_ATTEMPTS)
+            {
+                // Die
+                throw std::runtime_error("Cluster connection failed");
+            }
+            // Retry
+            tfd->set_timer(ETCD_QUICK_TIMEOUT, false, [this](int timer_id)
+            {
+                renew_lease();
+            });
+        }
+        else
+        {
+            etcd_failed_attempts = 0;
+            report_statistics();
+        }
+    });
+}
+
+void osd_t::force_stop(int exitcode)
+{
+    if (etcd_lease_id != "")
+    {
+        st_cli.etcd_call("/kv/lease/revoke", json11::Json::object {
+            { "ID", etcd_lease_id }
+        }, ETCD_QUICK_TIMEOUT, [this, exitcode](std::string err, json11::Json data)
+        {
+            if (err != "")
+            {
+                printf("Error revoking etcd lease: %s\n", err.c_str());
+            }
+            printf("[OSD %lu] Force stopping\n", this->osd_num);
+            exit(exitcode);
+        });
+    }
+    else
+    {
+        printf("[OSD %lu] Force stopping\n", this->osd_num);
+        exit(exitcode);
+    }
+}
+
+json11::Json osd_t::on_load_pgs_checks_hook()
+{
+    assert(this->pgs.size() == 0);
+    json11::Json::array checks = {
+        json11::Json::object {
+            { "target", "LEASE" },
+            { "lease", etcd_lease_id },
+            { "key", base64_encode(st_cli.etcd_prefix+"/osd/state/"+std::to_string(osd_num)) },
+        }
+    };
+    return checks;
+}
+
+void osd_t::on_load_pgs_hook(bool success)
+{
+    if (!success)
+    {
+        printf("Error loading PGs from etcd: lease expired\n");
+        force_stop(1);
+    }
+    else
+    {
+        peering_state &= ~OSD_LOADING_PGS;
+        apply_pg_count();
+        apply_pg_config();
+    }
+}
+
+void osd_t::apply_pg_count()
+{
+    for (auto & pool_item: st_cli.pool_config)
+    {
+        if (pool_item.second.real_pg_count != 0 &&
+            pool_item.second.real_pg_count != pg_counts[pool_item.first])
+        {
+            // Check that all pool PGs are offline. It is not allowed to change PG count when any PGs are online
+            // The external tool must wait for all PGs to come down before changing PG count
+            // If it doesn't wait, a restarted OSD may apply the new count immediately which will lead to bugs
+            // So an OSD just dies if it detects PG count change while there are active PGs
+            int still_active = 0;
+            for (auto & kv: pgs)
+            {
+                if (kv.first.pool_id == pool_item.first && (kv.second.state & PG_ACTIVE))
+                {
+                    still_active++;
+                }
+            }
+            if (still_active > 0)
+            {
+                printf("[OSD %lu] PG count change detected, but %d PG(s) are still active. This is not allowed. Exiting\n", this->osd_num, still_active);
+                force_stop(1);
+                return;
+            }
+        }
+        this->pg_counts[pool_item.first] = pool_item.second.real_pg_count;
+    }
+}
+
+void osd_t::apply_pg_config()
+{
+    bool all_applied = true;
+    for (auto & pool_item: st_cli.pool_config)
+    {
+        auto pool_id = pool_item.first;
+        for (auto & kv: pool_item.second.pg_config)
+        {
+            pg_num_t pg_num = kv.first;
+            auto & pg_cfg = kv.second;
+            bool take = pg_cfg.exists && pg_cfg.primary == this->osd_num &&
+                !pg_cfg.pause && (!pg_cfg.cur_primary || pg_cfg.cur_primary == this->osd_num);
+            auto pg_it = this->pgs.find({ .pool_id = pool_id, .pg_num = pg_num });
+            bool currently_taken = pg_it != this->pgs.end() && pg_it->second.state != PG_OFFLINE;
+            if (currently_taken && !take)
+            {
+                // Stop this PG
+                stop_pg(pg_it->second);
+            }
+            else if (take)
+            {
+                // Take this PG
+                std::set<osd_num_t> all_peers;
+                for (osd_num_t pg_osd: pg_cfg.target_set)
+                {
+                    if (pg_osd != 0)
+                    {
+                        all_peers.insert(pg_osd);
+                    }
+                }
+                for (osd_num_t pg_osd: pg_cfg.all_peers)
+                {
+                    if (pg_osd != 0)
+                    {
+                        all_peers.insert(pg_osd);
+                    }
+                }
+                for (auto & hist_item: pg_cfg.target_history)
+                {
+                    for (auto pg_osd: hist_item)
+                    {
+                        if (pg_osd != 0)
+                        {
+                            all_peers.insert(pg_osd);
+                        }
+                    }
+                }
+                if (currently_taken)
+                {
+                    if (pg_it->second.state & (PG_ACTIVE | PG_INCOMPLETE | PG_PEERING))
+                    {
+                        if (pg_it->second.target_set == pg_cfg.target_set)
+                        {
+                            // No change in osd_set; history changes are ignored
+                            continue;
+                        }
+                        else
+                        {
+                            // Stop PG, reapply change after stopping
+                            stop_pg(pg_it->second);
+                            all_applied = false;
+                            continue;
+                        }
+                    }
+                    else if (pg_it->second.state & PG_STOPPING)
+                    {
+                        // Reapply change after stopping
+                        all_applied = false;
+                        continue;
+                    }
+                    else if (pg_it->second.state & PG_STARTING)
+                    {
+                        if (pg_cfg.cur_primary == this->osd_num)
+                        {
+                            // PG locked, continue
+                        }
+                        else
+                        {
+                            // Reapply change after locking the PG
+                            all_applied = false;
+                            continue;
+                        }
+                    }
+                    else
+                    {
+                        throw std::runtime_error("Unexpected PG "+std::to_string(pg_num)+" state: "+std::to_string(pg_it->second.state));
+                    }
+                }
+                auto & pg = this->pgs[{ .pool_id = pool_id, .pg_num = pg_num }];
+                pg = (pg_t){
+                    .state = pg_cfg.cur_primary == this->osd_num ? PG_PEERING : PG_STARTING,
+                    .scheme = pool_item.second.scheme,
+                    .pg_cursize = 0,
+                    .pg_size = pool_item.second.pg_size,
+                    .pg_minsize = pool_item.second.pg_minsize,
+                    .pool_id = pool_id,
+                    .pg_num = pg_num,
+                    .reported_epoch = pg_cfg.epoch,
+                    .target_history = pg_cfg.target_history,
+                    .all_peers = std::vector<osd_num_t>(all_peers.begin(), all_peers.end()),
+                    .target_set = pg_cfg.target_set,
+                };
+                this->pg_state_dirty.insert({ .pool_id = pool_id, .pg_num = pg_num });
+                pg.print_state();
+                if (pg_cfg.cur_primary == this->osd_num)
+                {
+                    // Add peers
+                    for (auto pg_osd: all_peers)
+                    {
+                        if (pg_osd != this->osd_num && c_cli.osd_peer_fds.find(pg_osd) == c_cli.osd_peer_fds.end())
+                        {
+                            c_cli.connect_peer(pg_osd, st_cli.peer_states[pg_osd]);
+                        }
+                    }
+                    start_pg_peering(pg);
+                }
+                else
+                {
+                    // Reapply change after locking the PG
+                    all_applied = false;
+                }
+            }
+        }
+    }
+    report_pg_states();
+    this->pg_config_applied = all_applied;
+}
+
+void osd_t::report_pg_states()
+{
+    if (etcd_reporting_pg_state || !this->pg_state_dirty.size() || !st_cli.etcd_addresses.size())
+    {
+        return;
+    }
+    std::vector<std::pair<pool_pg_num_t,bool>> reporting_pgs;
+    json11::Json::array checks;
+    json11::Json::array success;
+    json11::Json::array failure;
+    for (auto it = pg_state_dirty.begin(); it != pg_state_dirty.end(); it++)
+    {
+        auto pg_it = this->pgs.find(*it);
+        if (pg_it == this->pgs.end())
+        {
+            continue;
+        }
+        auto & pg = pg_it->second;
+        reporting_pgs.push_back({ *it, pg.history_changed });
+        std::string state_key_base64 = base64_encode(st_cli.etcd_prefix+"/pg/state/"+std::to_string(pg.pool_id)+"/"+std::to_string(pg.pg_num));
+        if (pg.state == PG_STARTING)
+        {
+            // Check that the PG key does not exist
+            // Failed check indicates an unsuccessful PG lock attempt in this case
+            checks.push_back(json11::Json::object {
+                { "target", "VERSION" },
+                { "version", 0 },
+                { "key", state_key_base64 },
+            });
+        }
+        else
+        {
+            // Check that the key is ours
+            // Failed check indicates success for OFFLINE pgs (PG lock is already deleted)
+            // and an unexpected race condition for started pgs (PG lock is held by someone else)
+            checks.push_back(json11::Json::object {
+                { "target", "LEASE" },
+                { "lease", etcd_lease_id },
+                { "key", state_key_base64 },
+            });
+        }
+        if (pg.state == PG_OFFLINE)
+        {
+            success.push_back(json11::Json::object {
+                { "request_delete_range", json11::Json::object {
+                    { "key", state_key_base64 },
+                } }
+            });
+        }
+        else
+        {
+            json11::Json::array pg_state_keywords;
+            for (int i = 0; i < pg_state_bit_count; i++)
+            {
+                if (pg.state & pg_state_bits[i])
+                {
+                    pg_state_keywords.push_back(pg_state_names[i]);
+                }
+            }
+            success.push_back(json11::Json::object {
+                { "request_put", json11::Json::object {
+                    { "key", state_key_base64 },
+                    { "value", base64_encode(json11::Json(json11::Json::object {
+                        { "primary", this->osd_num },
+                        { "state", pg_state_keywords },
+                        { "peers", pg.cur_peers },
+                    }).dump()) },
+                    { "lease", etcd_lease_id },
+                } }
+            });
+            if (pg.history_changed)
+            {
+                // Prevent race conditions (for the case when the monitor is updating this key at the same time)
+                pg.history_changed = false;
+                std::string history_key = base64_encode(st_cli.etcd_prefix+"/pg/history/"+std::to_string(pg.pool_id)+"/"+std::to_string(pg.pg_num));
+                json11::Json::object history_value = {
+                    { "epoch", pg.epoch },
+                    { "all_peers", pg.all_peers },
+                    { "osd_sets", pg.target_history },
+                };
+                checks.push_back(json11::Json::object {
+                    { "target", "MOD" },
+                    { "key", history_key },
+                    { "result", "LESS" },
+                    { "mod_revision", st_cli.etcd_watch_revision+1 },
+                });
+                success.push_back(json11::Json::object {
+                    { "request_put", json11::Json::object {
+                        { "key", history_key },
+                        { "value", base64_encode(json11::Json(history_value).dump()) },
+                    } }
+                });
+            }
+        }
+        failure.push_back(json11::Json::object {
+            { "request_range", json11::Json::object {
+                { "key", state_key_base64 },
+            } }
+        });
+    }
+    pg_state_dirty.clear();
+    etcd_reporting_pg_state = true;
+    st_cli.etcd_txn(json11::Json::object {
+        { "compare", checks }, { "success", success }, { "failure", failure }
+    }, ETCD_QUICK_TIMEOUT, [this, reporting_pgs](std::string err, json11::Json data)
+    {
+        etcd_reporting_pg_state = false;
+        if (!data["succeeded"].bool_value())
+        {
+            // One of PG state updates failed, put dirty flags back
+            for (auto pp: reporting_pgs)
+            {
+                this->pg_state_dirty.insert(pp.first);
+                if (pp.second)
+                {
+                    auto pg_it = this->pgs.find(pp.first);
+                    if (pg_it != this->pgs.end())
+                    {
+                        pg_it->second.history_changed = true;
+                    }
+                }
+            }
+            for (auto & res: data["responses"].array_items())
+            {
+                if (res["kvs"].array_items().size())
+                {
+                    auto kv = st_cli.parse_etcd_kv(res["kvs"][0]);
+                    if (kv.key.substr(st_cli.etcd_prefix.length()+10) == st_cli.etcd_prefix+"/pg/state/")
+                    {
+                        pool_id_t pool_id = 0;
+                        pg_num_t pg_num = 0;
+                        char null_byte = 0;
+                        sscanf(kv.key.c_str() + st_cli.etcd_prefix.length()+10, "%u/%u%c", &pool_id, &pg_num, &null_byte);
+                        if (null_byte == 0)
+                        {
+                            auto pg_it = pgs.find({ .pool_id = pool_id, .pg_num = pg_num });
+                            if (pg_it != pgs.end() && pg_it->second.state != PG_OFFLINE && pg_it->second.state != PG_STARTING)
+                            {
+                                // Live PG state update failed
+                                printf("Failed to report state of pool %u PG %u which is live. Race condition detected, exiting\n", pool_id, pg_num);
+                                force_stop(1);
+                                return;
+                            }
+                        }
+                    }
+                }
+            }
+            // Retry after a short pause (hope we'll get some updates and update PG states accordingly)
+            tfd->set_timer(500, false, [this](int) { report_pg_states(); });
+        }
+        else
+        {
+            // Success. We'll get our changes back via the watcher and react to them
+            for (auto pp: reporting_pgs)
+            {
+                auto pg_it = this->pgs.find(pp.first);
+                if (pg_it != this->pgs.end())
+                {
+                    if (pg_it->second.state == PG_OFFLINE)
+                    {
+                        // Remove offline PGs after reporting their state
+                        this->pgs.erase(pg_it);
+                    }
+                }
+            }
+            // Push other PG state updates, if any
+            report_pg_states();
+            if (!this->pg_state_dirty.size())
+            {
+                // Update statistics
+                report_statistics();
+            }
+        }
+    });
+}

osd_flush.cpp

@@ -0,0 +1,300 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include "osd.h"
+
+#define FLUSH_BATCH 512
+
+void osd_t::submit_pg_flush_ops(pg_t & pg)
+{
+    pg_flush_batch_t *fb = new pg_flush_batch_t();
+    pg.flush_batch = fb;
+    auto it = pg.flush_actions.begin(), prev_it = pg.flush_actions.begin();
+    bool first = true;
+    while (it != pg.flush_actions.end())
+    {
+        if (!first && (it->first.oid.inode != prev_it->first.oid.inode ||
+            (it->first.oid.stripe & ~STRIPE_MASK) != (prev_it->first.oid.stripe & ~STRIPE_MASK)) &&
+            fb->rollback_lists[it->first.osd_num].size() >= FLUSH_BATCH ||
+            fb->stable_lists[it->first.osd_num].size() >= FLUSH_BATCH)
+        {
+            // Stop only at the object boundary
+            break;
+        }
+        it->second.submitted = true;
+        if (it->second.rollback)
+        {
+            fb->flush_objects++;
+            fb->rollback_lists[it->first.osd_num].push_back((obj_ver_id){
+                .oid = it->first.oid,
+                .version = it->second.rollback_to,
+            });
+        }
+        if (it->second.make_stable)
+        {
+            fb->flush_objects++;
+            fb->stable_lists[it->first.osd_num].push_back((obj_ver_id){
+                .oid = it->first.oid,
+                .version = it->second.stable_to,
+            });
+        }
+        prev_it = it;
+        first = false;
+        it++;
+    }
+    for (auto & l: fb->rollback_lists)
+    {
+        if (l.second.size() > 0)
+        {
+            fb->flush_ops++;
+            submit_flush_op(pg.pool_id, pg.pg_num, fb, true, l.first, l.second.size(), l.second.data());
+        }
+    }
+    for (auto & l: fb->stable_lists)
+    {
+        if (l.second.size() > 0)
+        {
+            fb->flush_ops++;
+            submit_flush_op(pg.pool_id, pg.pg_num, fb, false, l.first, l.second.size(), l.second.data());
+        }
+    }
+}
+
+void osd_t::handle_flush_op(bool rollback, pool_id_t pool_id, pg_num_t pg_num, pg_flush_batch_t *fb, osd_num_t peer_osd, int retval)
+{
+    pool_pg_num_t pg_id = { .pool_id = pool_id, .pg_num = pg_num };
+    if (pgs.find(pg_id) == pgs.end() || pgs[pg_id].flush_batch != fb)
+    {
+        // Throw the result away
+        return;
+    }
+    if (retval != 0)
+    {
+        if (peer_osd == this->osd_num)
+        {
+            throw std::runtime_error(
+                std::string(rollback
+                    ? "Error while doing local rollback operation: "
+                    : "Error while doing local stabilize operation: "
+                ) + strerror(-retval)
+            );
+        }
+        else
+        {
+            printf("Error while doing flush on OSD %lu: %d (%s)\n", osd_num, retval, strerror(-retval));
+            auto fd_it = c_cli.osd_peer_fds.find(peer_osd);
+            if (fd_it != c_cli.osd_peer_fds.end())
+            {
+                c_cli.stop_client(fd_it->second);
+            }
+            return;
+        }
+    }
+    fb->flush_done++;
+    if (fb->flush_done == fb->flush_ops)
+    {
+        // This flush batch is done
+        std::vector<osd_op_t*> continue_ops;
+        auto & pg = pgs[pg_id];
+        auto it = pg.flush_actions.begin(), prev_it = it;
+        auto erase_start = it;
+        while (1)
+        {
+            if (it == pg.flush_actions.end() ||
+                it->first.oid.inode != prev_it->first.oid.inode ||
+                (it->first.oid.stripe & ~STRIPE_MASK) != (prev_it->first.oid.stripe & ~STRIPE_MASK))
+            {
+                pg.ver_override.erase((object_id){
+                    .inode = prev_it->first.oid.inode,
+                    .stripe = (prev_it->first.oid.stripe & ~STRIPE_MASK),
+                });
+                auto wr_it = pg.write_queue.find((object_id){
+                    .inode = prev_it->first.oid.inode,
+                    .stripe = (prev_it->first.oid.stripe & ~STRIPE_MASK),
+                });
+                if (wr_it != pg.write_queue.end())
+                {
+                    continue_ops.push_back(wr_it->second);
+                    pg.write_queue.erase(wr_it);
+                }
+            }
+            if ((it == pg.flush_actions.end() || !it->second.submitted) &&
+                erase_start != it)
+            {
+                pg.flush_actions.erase(erase_start, it);
+            }
+            if (it == pg.flush_actions.end())
+            {
+                break;
+            }
+            prev_it = it;
+            if (!it->second.submitted)
+            {
+                it++;
+                erase_start = it;
+            }
+            else
+            {
+                it++;
+            }
+        }
+        delete fb;
+        pg.flush_batch = NULL;
+        if (!pg.flush_actions.size())
+        {
+            pg.state = pg.state & ~PG_HAS_UNCLEAN;
+            report_pg_state(pg);
+        }
+        for (osd_op_t *op: continue_ops)
+        {
+            continue_primary_write(op);
+        }
+        if (pg.inflight == 0 && (pg.state & PG_STOPPING))
+        {
+            finish_stop_pg(pg);
+        }
+    }
+}
+
+void osd_t::submit_flush_op(pool_id_t pool_id, pg_num_t pg_num, pg_flush_batch_t *fb, bool rollback, osd_num_t peer_osd, int count, obj_ver_id *data)
+{
+    osd_op_t *op = new osd_op_t();
+    // Copy buffer so it gets freed along with the operation
+    op->buf = malloc_or_die(sizeof(obj_ver_id) * count);
+    memcpy(op->buf, data, sizeof(obj_ver_id) * count);
+    if (peer_osd == this->osd_num)
+    {
+        // local
+        clock_gettime(CLOCK_REALTIME, &op->tv_begin);
+        op->bs_op = new blockstore_op_t({
+            .opcode = (uint64_t)(rollback ? BS_OP_ROLLBACK : BS_OP_STABLE),
+            .callback = [this, op, pool_id, pg_num, fb](blockstore_op_t *bs_op)
+            {
+                add_bs_subop_stats(op);
+                handle_flush_op(bs_op->opcode == BS_OP_ROLLBACK, pool_id, pg_num, fb, this->osd_num, bs_op->retval);
+                delete op->bs_op;
+                op->bs_op = NULL;
+                delete op;
+            },
+            .len = (uint32_t)count,
+            .buf = op->buf,
+        });
+        bs->enqueue_op(op->bs_op);
+    }
+    else
+    {
+        // Peer
+        int peer_fd = c_cli.osd_peer_fds[peer_osd];
+        op->op_type = OSD_OP_OUT;
+        op->iov.push_back(op->buf, count * sizeof(obj_ver_id));
+        op->peer_fd = peer_fd;
+        op->req = {
+            .sec_stab = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = c_cli.next_subop_id++,
+                    .opcode = (uint64_t)(rollback ? OSD_OP_SEC_ROLLBACK : OSD_OP_SEC_STABILIZE),
+                },
+                .len = count * sizeof(obj_ver_id),
+            },
+        };
+        op->callback = [this, pool_id, pg_num, fb, peer_osd](osd_op_t *op)
+        {
+            handle_flush_op(op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK, pool_id, pg_num, fb, peer_osd, op->reply.hdr.retval);
+            delete op;
+        };
+        c_cli.outbox_push(op);
+    }
+}
+
+bool osd_t::pick_next_recovery(osd_recovery_op_t &op)
+{
+    for (auto pg_it = pgs.begin(); pg_it != pgs.end(); pg_it++)
+    {
+        if ((pg_it->second.state & (PG_ACTIVE | PG_HAS_DEGRADED)) == (PG_ACTIVE | PG_HAS_DEGRADED))
+        {
+            for (auto obj_it = pg_it->second.degraded_objects.begin(); obj_it != pg_it->second.degraded_objects.end(); obj_it++)
+            {
+                if (recovery_ops.find(obj_it->first) == recovery_ops.end())
+                {
+                    op.degraded = true;
+                    op.oid = obj_it->first;
+                    return true;
+                }
+            }
+        }
+    }
+    for (auto pg_it = pgs.begin(); pg_it != pgs.end(); pg_it++)
+    {
+        if ((pg_it->second.state & (PG_ACTIVE | PG_HAS_MISPLACED)) == (PG_ACTIVE | PG_HAS_MISPLACED))
+        {
+            for (auto obj_it = pg_it->second.misplaced_objects.begin(); obj_it != pg_it->second.misplaced_objects.end(); obj_it++)
+            {
+                if (recovery_ops.find(obj_it->first) == recovery_ops.end())
+                {
+                    op.degraded = false;
+                    op.oid = obj_it->first;
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+void osd_t::submit_recovery_op(osd_recovery_op_t *op)
+{
+    op->osd_op = new osd_op_t();
+    op->osd_op->op_type = OSD_OP_OUT;
+    op->osd_op->req = {
+        .rw = {
+            .header = {
+                .magic = SECONDARY_OSD_OP_MAGIC,
+                .id = 1,
+                .opcode = OSD_OP_WRITE,
+            },
+            .inode = op->oid.inode,
+            .offset = op->oid.stripe,
+            .len = 0,
+        },
+    };
+    op->osd_op->callback = [this, op](osd_op_t *osd_op)
+    {
+        // Don't sync the write, it will be synced by our regular sync coroutine
+        if (osd_op->reply.hdr.retval < 0)
+        {
+            // Error recovering object
+            if (osd_op->reply.hdr.retval == -EPIPE)
+            {
+                // PG is stopped or one of the OSDs is gone, error is harmless
+            }
+            else
+            {
+                throw std::runtime_error("Failed to recover an object");
+            }
+        }
+        // CAREFUL! op = &recovery_ops[op->oid]. Don't access op->* after recovery_ops.erase()
+        op->osd_op = NULL;
+        recovery_ops.erase(op->oid);
+        delete osd_op;
+        continue_recovery();
+    };
+    exec_op(op->osd_op);
+}
+
+// Just trigger write requests for degraded objects. They'll be recovered during writing
+bool osd_t::continue_recovery()
+{
+    while (recovery_ops.size() < recovery_queue_depth)
+    {
+        osd_recovery_op_t op;
+        if (pick_next_recovery(op))
+        {
+            recovery_ops[op.oid] = op;
+            submit_recovery_op(&recovery_ops[op.oid]);
+        }
+        else
+            return false;
+    }
+    return true;
+}

osd_id.h

@@ -1,4 +1,27 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #pragma once
 
+#define POOL_SCHEME_REPLICATED 1
+#define POOL_SCHEME_XOR 2
+#define POOL_ID_MAX 0x10000
+#define POOL_ID_BITS 16
+#define INODE_POOL(inode) (pool_id_t)((inode) >> (64 - POOL_ID_BITS))
+
+// Pool ID is 16 bits long
+typedef uint32_t pool_id_t;
+
 typedef uint64_t osd_num_t;
 typedef uint32_t pg_num_t;
+
+struct pool_pg_num_t
+{
+    pool_id_t pool_id;
+    pg_num_t pg_num;
+};
+
+inline bool operator < (const pool_pg_num_t & a, const pool_pg_num_t & b)
+{
+    return a.pool_id < b.pool_id || a.pool_id == b.pool_id && a.pg_num < b.pg_num;
+}

osd_main.cpp

@@ -1,14 +1,28 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "osd.h"
 
 #include <signal.h>
 
-void handle_sigint(int sig)
+static osd_t *osd = NULL;
+static bool force_stopping = false;
+
+static void handle_sigint(int sig)
 {
+    if (osd && !force_stopping)
+    {
+        force_stopping = true;
+        osd->force_stop(0);
+        return;
+    }
     exit(0);
 }
 
 int main(int narg, char *args[])
 {
+    setvbuf(stdout, NULL, _IONBF, 0);
+    setvbuf(stderr, NULL, _IONBF, 0);
     if (sizeof(osd_any_op_t) > OSD_PACKET_SIZE ||
         sizeof(osd_any_reply_t) > OSD_PACKET_SIZE)
     {
@@ -25,9 +39,11 @@ int main(int narg, char *args[])
         }
     }
     signal(SIGINT, handle_sigint);
+    signal(SIGTERM, handle_sigint);
     ring_loop_t *ringloop = new ring_loop_t(512);
+    // FIXME: Create Blockstore from on-disk superblock config and check it against the OSD cluster config
     blockstore_t *bs = new blockstore_t(config, ringloop);
-    osd_t *osd = new osd_t(config, bs, ringloop);
+    osd = new osd_t(config, bs, ringloop);
     while (1)
     {
         ringloop->loop();

osd_ops.cpp

@@ -0,0 +1,22 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "osd_ops.h"
+
+const char* osd_op_names[] = {
+    "",
+    "read",
+    "write",
+    "write_stable",
+    "sync",
+    "stabilize",
+    "rollback",
+    "delete",
+    "sync_stab_all",
+    "list",
+    "show_config",
+    "primary_read",
+    "primary_write",
+    "primary_sync",
+    "primary_delete",
+};

osd_ops.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #pragma once
 
 #include "object_id.h"
@@ -10,21 +13,25 @@
 #define OSD_PACKET_SIZE             0x80
 // Opcodes
 #define OSD_OP_MIN                  1
-#define OSD_OP_SECONDARY_READ       1
-#define OSD_OP_SECONDARY_WRITE      2
-#define OSD_OP_SECONDARY_SYNC       3
-#define OSD_OP_SECONDARY_STABILIZE  4
-#define OSD_OP_SECONDARY_ROLLBACK   5
-#define OSD_OP_SECONDARY_DELETE     6
-#define OSD_OP_TEST_SYNC_STAB_ALL   7
-#define OSD_OP_SECONDARY_LIST       8
-#define OSD_OP_SHOW_CONFIG          9
-#define OSD_OP_READ                 10
-#define OSD_OP_WRITE                11
-#define OSD_OP_SYNC                 12
-#define OSD_OP_MAX                  12
+#define OSD_OP_SEC_READ             1
+#define OSD_OP_SEC_WRITE            2
+#define OSD_OP_SEC_WRITE_STABLE     3
+#define OSD_OP_SEC_SYNC             4
+#define OSD_OP_SEC_STABILIZE        5
+#define OSD_OP_SEC_ROLLBACK         6
+#define OSD_OP_SEC_DELETE           7
+#define OSD_OP_TEST_SYNC_STAB_ALL   8
+#define OSD_OP_SEC_LIST             9
+#define OSD_OP_SHOW_CONFIG          10
+#define OSD_OP_READ                 11
+#define OSD_OP_WRITE                12
+#define OSD_OP_SYNC                 13
+#define OSD_OP_DELETE               14
+#define OSD_OP_MAX                  14
 // Alignment & limit for read/write operations
-#define OSD_RW_ALIGN                512
+#ifndef MEM_ALIGNMENT
+#define MEM_ALIGNMENT               512
+#endif
 #define OSD_RW_MAX                  64*1024*1024
 
 // common request and reply headers
@@ -57,6 +64,7 @@ struct __attribute__((__packed__)) osd_op_secondary_rw_t
     // object
     object_id oid;
     // read/write version (automatic or specific)
+    // FIXME deny values close to UINT64_MAX
     uint64_t version;
     // offset
     uint32_t offset;
@@ -130,7 +138,10 @@ struct __attribute__((__packed__)) osd_op_secondary_list_t
     osd_op_header_t header;
     // placement group total number and total count
     pg_num_t list_pg, pg_count;
-    uint64_t parity_block_size;
+    // size of an area that maps to one PG continuously
+    uint64_t pg_stripe_size;
+    // inode range (used to select pools)
+    uint64_t min_inode, max_inode;
 };
 
 struct __attribute__((__packed__)) osd_reply_secondary_list_t
@@ -142,6 +153,7 @@ struct __attribute__((__packed__)) osd_reply_secondary_list_t
 };
 
 // read or write to the primary OSD (must be within individual stripe)
+// FIXME: allow to return used block bitmap (required for snapshots)
 struct __attribute__((__packed__)) osd_op_rw_t
 {
     osd_op_header_t header;
@@ -169,6 +181,7 @@ struct __attribute__((__packed__)) osd_reply_sync_t
     osd_reply_header_t header;
 };
 
+// FIXME it would be interesting to try to unify blockstore_op and osd_op formats
 union osd_any_op_t
 {
     osd_op_header_t hdr;
@@ -196,3 +209,5 @@ union osd_any_reply_t
     osd_reply_sync_t sync;
     uint8_t buf[OSD_PACKET_SIZE];
 };
+
+extern const char* osd_op_names[];

osd_peering.cpp

@@ -1,289 +1,234 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <netinet/tcp.h>
 #include <sys/epoll.h>
 
 #include <algorithm>
 
+#include "base64.h"
 #include "osd.h"
 
-void osd_t::init_primary()
-{
-    // Initial test version of clustering code requires exactly 2 peers
-    // FIXME Hardcode
-    std::string peerstr = config["peers"];
-    while (peerstr.size())
-    {
-        int pos = peerstr.find(',');
-        peers.push_back(parse_peer(pos < 0 ? peerstr : peerstr.substr(0, pos)));
-        peerstr = pos < 0 ? std::string("") : peerstr.substr(pos+1);
-        for (int i = 0; i < peers.size()-1; i++)
-            if (peers[i].osd_num == peers[peers.size()-1].osd_num)
-                throw std::runtime_error("same osd number "+std::to_string(peers[i].osd_num)+" specified twice in peers");
-    }
-    if (peers.size() < 2)
-        throw std::runtime_error("run_primary requires at least 2 peers");
-    pgs.push_back((pg_t){
-        .state = PG_OFFLINE,
-        .pg_cursize = 0,
-        .pg_num = 1,
-        .target_set = { 1, 2, 3 },
-        .cur_set = { 1, 0, 0 },
-    });
-    pg_count = 1;
-    peering_state = OSD_PEERING_PEERS;
-}
-
-osd_peer_def_t osd_t::parse_peer(std::string peer)
-{
-    // OSD_NUM:IP:PORT
-    int pos1 = peer.find(':');
-    int pos2 = peer.find(':', pos1+1);
-    if (pos1 < 0 || pos2 < 0)
-        throw new std::runtime_error("OSD peer string must be in the form OSD_NUM:IP:PORT");
-    osd_peer_def_t r;
-    r.addr = peer.substr(pos1+1, pos2-pos1-1);
-    std::string osd_num_str = peer.substr(0, pos1);
-    std::string port_str = peer.substr(pos2+1);
-    r.osd_num = strtoull(osd_num_str.c_str(), NULL, 10);
-    if (!r.osd_num)
-        throw new std::runtime_error("Could not parse OSD peer osd_num");
-    r.port = strtoull(port_str.c_str(), NULL, 10);
-    if (!r.port)
-        throw new std::runtime_error("Could not parse OSD peer port");
-    return r;
-}
-
-void osd_t::connect_peer(osd_num_t osd_num, const char *peer_host, int peer_port, std::function<void(osd_num_t, int)> callback)
-{
-    struct sockaddr_in addr;
-    int r;
-    if ((r = inet_pton(AF_INET, peer_host, &addr.sin_addr)) != 1)
-    {
-        callback(osd_num, -EINVAL);
-        return;
-    }
-    addr.sin_family = AF_INET;
-    addr.sin_port = htons(peer_port ? peer_port : 11203);
-    int peer_fd = socket(AF_INET, SOCK_STREAM, 0);
-    if (peer_fd < 0)
-    {
-        callback(osd_num, -errno);
-        return;
-    }
-    fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL, 0) | O_NONBLOCK);
-    r = connect(peer_fd, (sockaddr*)&addr, sizeof(addr));
-    if (r < 0 && errno != EINPROGRESS)
-    {
-        close(peer_fd);
-        callback(osd_num, -errno);
-        return;
-    }
-    clients[peer_fd] = (osd_client_t){
-        .peer_addr = addr,
-        .peer_port = peer_port,
-        .peer_fd = peer_fd,
-        .peer_state = PEER_CONNECTING,
-        .connect_callback = callback,
-        .osd_num = osd_num,
-    };
-    osd_peer_fds[osd_num] = peer_fd;
-    // Add FD to epoll (EPOLLOUT for tracking connect() result)
-    epoll_event ev;
-    ev.data.fd = peer_fd;
-    ev.events = EPOLLOUT | EPOLLIN | EPOLLRDHUP | EPOLLET;
-    if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, peer_fd, &ev) < 0)
-    {
-        throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
-    }
-}
-
-void osd_t::handle_connect_result(int peer_fd)
-{
-    auto & cl = clients[peer_fd];
-    osd_num_t osd_num = cl.osd_num;
-    auto callback = cl.connect_callback;
-    int result = 0;
-    socklen_t result_len = sizeof(result);
-    if (getsockopt(peer_fd, SOL_SOCKET, SO_ERROR, &result, &result_len) < 0)
-    {
-        result = errno;
-    }
-    if (result != 0)
-    {
-        stop_client(peer_fd);
-        callback(osd_num, -result);
-        return;
-    }
-    int one = 1;
-    setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
-    // Disable EPOLLOUT on this fd
-    cl.peer_fd_index = ringloop->register_fd(peer_fd);
-    cl.connect_callback = NULL;
-    cl.peer_state = PEER_CONNECTED;
-    epoll_event ev;
-    ev.data.fd = peer_fd;
-    ev.events = EPOLLIN | EPOLLRDHUP | EPOLLET;
-    if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, peer_fd, &ev) < 0)
-    {
-        throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
-    }
-    callback(osd_num, peer_fd);
-}
-
 // Peering loop
 void osd_t::handle_peers()
 {
-    if (peering_state & OSD_PEERING_PEERS)
-    {
-        for (int i = 0; i < peers.size(); i++)
-        {
-            if (osd_peer_fds.find(peers[i].osd_num) == osd_peer_fds.end() &&
-                time(NULL) - peers[i].last_connect_attempt > 5) // FIXME hardcode 5
-            {
-                peers[i].last_connect_attempt = time(NULL);
-                connect_peer(peers[i].osd_num, peers[i].addr.c_str(), peers[i].port, [this](osd_num_t osd_num, int peer_fd)
-                {
-                    // FIXME: Check peer config after connecting
-                    if (peer_fd < 0)
-                    {
-                        printf("Failed to connect to peer OSD %lu: %s\n", osd_num, strerror(-peer_fd));
-                        return;
-                    }
-                    printf("Connected with peer OSD %lu (fd %d)\n", clients[peer_fd].osd_num, peer_fd);
-                    int i;
-                    for (i = 0; i < peers.size(); i++)
-                    {
-                        if (osd_peer_fds.find(peers[i].osd_num) == osd_peer_fds.end())
-                            break;
-                    }
-                    if (i >= peers.size())
-                    {
-                        // Connected to all peers
-                        peering_state = peering_state & ~OSD_PEERING_PEERS;
-                    }
-                    repeer_pgs(osd_num, true);
-                });
-            }
-        }
-    }
     if (peering_state & OSD_PEERING_PGS)
     {
-        bool still_doing_pgs = false;
-        for (int i = 0; i < pgs.size(); i++)
+        bool still = false;
+        for (auto & p: pgs)
         {
-            if (pgs[i].state == PG_PEERING)
+            if (p.second.state == PG_PEERING)
             {
-                if (!pgs[i].peering_state->list_ops.size())
+                if (!p.second.peering_state->list_ops.size())
                 {
-                    pgs[i].calc_object_states();
+                    p.second.calc_object_states(log_level);
+                    report_pg_state(p.second);
+                    incomplete_objects += p.second.incomplete_objects.size();
+                    misplaced_objects += p.second.misplaced_objects.size();
+                    // FIXME: degraded objects may currently include misplaced, too! Report them separately?
+                    degraded_objects += p.second.degraded_objects.size();
+                    if ((p.second.state & (PG_ACTIVE | PG_HAS_UNCLEAN)) == (PG_ACTIVE | PG_HAS_UNCLEAN))
+                        peering_state = peering_state | OSD_FLUSHING_PGS;
+                    else if (p.second.state & PG_ACTIVE)
+                        peering_state = peering_state | OSD_RECOVERING;
                 }
                 else
                 {
-                    still_doing_pgs = true;
+                    still = true;
                 }
             }
         }
-        if (!still_doing_pgs)
+        if (!still)
         {
             // Done all PGs
             peering_state = peering_state & ~OSD_PEERING_PGS;
         }
     }
-}
-
-void osd_t::repeer_pgs(osd_num_t osd_num, bool is_connected)
-{
-    // Re-peer affected PGs
-    // FIXME: We shouldn't rely just on target_set. Other OSDs may also contain PG data.
-    osd_num_t real_osd = (is_connected ? osd_num : 0);
-    for (int i = 0; i < pgs.size(); i++)
+    if ((peering_state & OSD_FLUSHING_PGS) && !readonly)
     {
-        bool repeer = false;
-        for (int r = 0; r < pgs[i].target_set.size(); r++)
+        bool still = false;
+        for (auto & p: pgs)
         {
-            if (pgs[i].target_set[r] == osd_num &&
-                pgs[i].cur_set[r] != real_osd)
+            if ((p.second.state & (PG_ACTIVE | PG_HAS_UNCLEAN)) == (PG_ACTIVE | PG_HAS_UNCLEAN))
             {
-                pgs[i].cur_set[r] = real_osd;
-                repeer = true;
-                break;
+                if (!p.second.flush_batch)
+                {
+                    submit_pg_flush_ops(p.second);
+                }
+                still = true;
             }
         }
-        if (repeer)
+        if (!still)
         {
-            // Repeer this pg
-            printf("Repeer PG %d because of OSD %lu\n", i, osd_num);
-            start_pg_peering(i);
-            peering_state |= OSD_PEERING_PGS;
+            peering_state = peering_state & ~OSD_FLUSHING_PGS | OSD_RECOVERING;
+        }
+    }
+    if ((peering_state & OSD_RECOVERING) && !readonly)
+    {
+        if (!continue_recovery())
+        {
+            peering_state = peering_state & ~OSD_RECOVERING;
+        }
+    }
+}
+
+void osd_t::repeer_pgs(osd_num_t peer_osd)
+{
+    // Re-peer affected PGs
+    for (auto & p: pgs)
+    {
+        bool repeer = false;
+        if (p.second.state & (PG_PEERING | PG_ACTIVE | PG_INCOMPLETE))
+        {
+            for (osd_num_t pg_osd: p.second.all_peers)
+            {
+                if (pg_osd == peer_osd)
+                {
+                    repeer = true;
+                    break;
+                }
+            }
+            if (repeer)
+            {
+                // Repeer this pg
+                printf("[PG %u] Repeer because of OSD %lu\n", p.second.pg_num, peer_osd);
+                start_pg_peering(p.second);
+            }
         }
     }
 }
 
 // Repeer on each connect/disconnect peer event
-void osd_t::start_pg_peering(int pg_idx)
+void osd_t::start_pg_peering(pg_t & pg)
 {
-    auto & pg = pgs[pg_idx];
     pg.state = PG_PEERING;
+    this->peering_state |= OSD_PEERING_PGS;
+    report_pg_state(pg);
+    // Reset PG state
+    pg.cur_peers.clear();
     pg.state_dict.clear();
-    pg.obj_states.clear();
+    incomplete_objects -= pg.incomplete_objects.size();
+    misplaced_objects -= pg.misplaced_objects.size();
+    degraded_objects -= pg.degraded_objects.size();
+    pg.incomplete_objects.clear();
+    pg.misplaced_objects.clear();
+    pg.degraded_objects.clear();
+    pg.flush_actions.clear();
     pg.ver_override.clear();
-    pg.pg_cursize = 0;
-    for (int role = 0; role < pg.cur_set.size(); role++)
+    if (pg.flush_batch)
     {
+        delete pg.flush_batch;
+    }
+    pg.flush_batch = NULL;
+    for (auto p: pg.write_queue)
+    {
+        cancel_primary_write(p.second);
+    }
+    pg.write_queue.clear();
+    uint64_t pg_stripe_size = st_cli.pool_config[pg.pool_id].pg_stripe_size;
+    for (auto it = unstable_writes.begin(); it != unstable_writes.end(); )
+    {
+        // Forget this PG's unstable writes
+        if (INODE_POOL(it->first.oid.inode) == pg.pool_id && map_to_pg(it->first.oid, pg_stripe_size) == pg.pg_num)
+            unstable_writes.erase(it++);
+        else
+            it++;
+    }
+    dirty_pgs.erase({ .pool_id = pg.pool_id, .pg_num = pg.pg_num });
+    // Drop connections of clients who have this PG in dirty_pgs
+    if (immediate_commit != IMMEDIATE_ALL)
+    {
+        std::vector<int> to_stop;
+        for (auto & cp: c_cli.clients)
+        {
+            if (cp.second.dirty_pgs.find({ .pool_id = pg.pool_id, .pg_num = pg.pg_num }) != cp.second.dirty_pgs.end())
+            {
+                to_stop.push_back(cp.first);
+            }
+        }
+        for (auto peer_fd: to_stop)
+        {
+            c_cli.stop_client(peer_fd);
+        }
+    }
+    // Calculate current write OSD set
+    pg.pg_cursize = 0;
+    pg.cur_set.resize(pg.target_set.size());
+    pg.cur_loc_set.clear();
+    for (int role = 0; role < pg.target_set.size(); role++)
+    {
+        pg.cur_set[role] = pg.target_set[role] == this->osd_num ||
+            c_cli.osd_peer_fds.find(pg.target_set[role]) != c_cli.osd_peer_fds.end() ? pg.target_set[role] : 0;
         if (pg.cur_set[role] != 0)
         {
             pg.pg_cursize++;
+            pg.cur_loc_set.push_back({
+                .role = (uint64_t)role,
+                .osd_num = pg.cur_set[role],
+                .outdated = false,
+            });
+        }
+    }
+    if (pg.target_history.size())
+    {
+        // Refuse to start PG if no peers are available from any of the historical OSD sets
+        // (PG history is kept up to the latest active+clean state)
+        for (auto & history_set: pg.target_history)
+        {
+            bool found = false;
+            for (auto history_osd: history_set)
+            {
+                if (history_osd != 0 && c_cli.osd_peer_fds.find(history_osd) != c_cli.osd_peer_fds.end())
+                {
+                    found = true;
+                    break;
+                }
+            }
+            if (!found)
+            {
+                pg.state = PG_INCOMPLETE;
+                report_pg_state(pg);
+                return;
+            }
         }
     }
     if (pg.pg_cursize < pg.pg_minsize)
     {
         pg.state = PG_INCOMPLETE;
+        report_pg_state(pg);
+        return;
     }
+    std::set<osd_num_t> cur_peers;
+    for (auto pg_osd: pg.all_peers)
+    {
+        if (pg_osd == this->osd_num || c_cli.osd_peer_fds.find(pg_osd) != c_cli.osd_peer_fds.end())
+        {
+            cur_peers.insert(pg_osd);
+        }
+        else if (c_cli.wanted_peers.find(pg_osd) == c_cli.wanted_peers.end())
+        {
+            c_cli.connect_peer(pg_osd, st_cli.peer_states[pg_osd]);
+        }
+    }
+    pg.cur_peers.insert(pg.cur_peers.begin(), cur_peers.begin(), cur_peers.end());
     if (pg.peering_state)
     {
-        // Adjust the peering operation that's still in progress
-        for (auto it = pg.peering_state->list_ops.begin(); it != pg.peering_state->list_ops.end(); it++)
+        // Adjust the peering operation that's still in progress - discard unneeded results
+        for (auto it = pg.peering_state->list_ops.begin(); it != pg.peering_state->list_ops.end();)
         {
-            int role;
-            for (role = 0; role < pg.cur_set.size(); role++)
-            {
-                if (pg.cur_set[role] == it->first)
-                    break;
-            }
-            if (pg.state == PG_INCOMPLETE || role >= pg.cur_set.size())
+            if (pg.state == PG_INCOMPLETE || cur_peers.find(it->first) == cur_peers.end())
             {
                 // Discard the result after completion, which, chances are, will be unsuccessful
-                auto list_op = it->second;
-                if (list_op->peer_fd == 0)
-                {
-                    // Self
-                    list_op->bs_op->callback = [list_op](blockstore_op_t *bs_op)
-                    {
-                        if (list_op->bs_op->buf)
-                            free(list_op->bs_op->buf);
-                        delete list_op;
-                    };
-                }
-                else
-                {
-                    // Peer
-                    list_op->callback = [](osd_op_t *list_op)
-                    {
-                        delete list_op;
-                    };
-                }
+                discard_list_subop(it->second);
                 pg.peering_state->list_ops.erase(it);
                 it = pg.peering_state->list_ops.begin();
             }
+            else
+                it++;
         }
-        for (auto it = pg.peering_state->list_results.begin(); it != pg.peering_state->list_results.end(); it++)
+        for (auto it = pg.peering_state->list_results.begin(); it != pg.peering_state->list_results.end();)
         {
-            int role;
-            for (role = 0; role < pg.cur_set.size(); role++)
-            {
-                if (pg.cur_set[role] == it->first)
-                    break;
-            }
-            if (pg.state == PG_INCOMPLETE || role >= pg.cur_set.size())
+            if (pg.state == PG_INCOMPLETE || cur_peers.find(it->first) == cur_peers.end())
             {
                 if (it->second.buf)
                 {
@@ -292,6 +237,8 @@ void osd_t::start_pg_peering(int pg_idx)
                 pg.peering_state->list_results.erase(it);
                 it = pg.peering_state->list_results.begin();
             }
+            else
+                it++;
         }
     }
     if (pg.state == PG_INCOMPLETE)
@@ -301,107 +248,297 @@ void osd_t::start_pg_peering(int pg_idx)
             delete pg.peering_state;
             pg.peering_state = NULL;
         }
-        printf("PG %d is incomplete\n", pg.pg_num);
         return;
     }
     if (!pg.peering_state)
     {
         pg.peering_state = new pg_peering_state_t();
+        pg.peering_state->pool_id = pg.pool_id;
+        pg.peering_state->pg_num = pg.pg_num;
     }
-    auto ps = pg.peering_state;
-    for (int role = 0; role < pg.cur_set.size(); role++)
+    for (osd_num_t peer_osd: cur_peers)
     {
-        osd_num_t role_osd = pg.cur_set[role];
-        if (!role_osd)
+        if (pg.peering_state->list_ops.find(peer_osd) != pg.peering_state->list_ops.end() ||
+            pg.peering_state->list_results.find(peer_osd) != pg.peering_state->list_results.end())
         {
             continue;
         }
-        if (ps->list_ops.find(role_osd) != ps->list_ops.end() ||
-            ps->list_results.find(role_osd) != ps->list_results.end())
-        {
-            continue;
-        }
-        if (role_osd == this->osd_num)
-        {
-            // Self
-            osd_op_t *op = new osd_op_t();
-            op->op_type = 0;
-            op->peer_fd = 0;
-            op->bs_op = new blockstore_op_t();
-            op->bs_op->opcode = BS_OP_LIST;
-            op->bs_op->oid.stripe = parity_block_size;
-            op->bs_op->len = pg_count,
-            op->bs_op->offset = pg.pg_num-1,
-            op->bs_op->callback = [ps, op, role_osd](blockstore_op_t *bs_op)
-            {
-                if (op->bs_op->retval < 0)
-                {
-                    throw std::runtime_error("local OP_LIST failed");
-                }
-                printf(
-                    "Got object list from OSD %lu (local): %d object versions (%lu of them stable)\n",
-                    role_osd, bs_op->retval, bs_op->version
-                );
-                ps->list_results[role_osd] = {
-                    .buf = (obj_ver_id*)op->bs_op->buf,
-                    .total_count = (uint64_t)op->bs_op->retval,
-                    .stable_count = op->bs_op->version,
-                };
-                ps->list_done++;
-                ps->list_ops.erase(role_osd);
-                delete op;
-            };
-            bs->enqueue_op(op->bs_op);
-            ps->list_ops[role_osd] = op;
-        }
-        else
-        {
-            // Peer
-            auto & cl = clients[osd_peer_fds[role_osd]];
-            osd_op_t *op = new osd_op_t();
-            op->op_type = OSD_OP_OUT;
-            op->send_list.push_back(op->req.buf, OSD_PACKET_SIZE);
-            op->peer_fd = cl.peer_fd;
-            op->req = {
-                .sec_list = {
-                    .header = {
-                        .magic = SECONDARY_OSD_OP_MAGIC,
-                        .id = this->next_subop_id++,
-                        .opcode = OSD_OP_SECONDARY_LIST,
-                    },
-                    .list_pg = pg.pg_num,
-                    .pg_count = pg_count,
-                    .parity_block_size = parity_block_size,
-                },
-            };
-            op->callback = [this, ps, role_osd](osd_op_t *op)
-            {
-                if (op->reply.hdr.retval < 0)
-                {
-                    printf("Failed to get object list from OSD %lu (retval=%ld), disconnecting peer\n", role_osd, op->reply.hdr.retval);
-                    ps->list_ops.erase(role_osd);
-                    stop_client(op->peer_fd);
-                    delete op;
-                    return;
-                }
-                printf(
-                    "Got object list from OSD %lu: %ld object versions (%lu of them stable)\n",
-                    role_osd, op->reply.hdr.retval, op->reply.sec_list.stable_count
-                );
-                ps->list_results[role_osd] = {
-                    .buf = (obj_ver_id*)op->buf,
-                    .total_count = (uint64_t)op->reply.hdr.retval,
-                    .stable_count = op->reply.sec_list.stable_count,
-                };
-                // set op->buf to NULL so it doesn't get freed
-                op->buf = NULL;
-                ps->list_done++;
-                ps->list_ops.erase(role_osd);
-                delete op;
-            };
-            outbox_push(cl, op);
-            ps->list_ops[role_osd] = op;
-        }
+        submit_sync_and_list_subop(peer_osd, pg.peering_state);
     }
     ringloop->wakeup();
 }
+
+void osd_t::submit_sync_and_list_subop(osd_num_t role_osd, pg_peering_state_t *ps)
+{
+    // Sync before listing, if not readonly
+    if (readonly)
+    {
+        submit_list_subop(role_osd, ps);
+    }
+    else if (role_osd == this->osd_num)
+    {
+        // Self
+        osd_op_t *op = new osd_op_t();
+        op->op_type = 0;
+        op->peer_fd = 0;
+        clock_gettime(CLOCK_REALTIME, &op->tv_begin);
+        op->bs_op = new blockstore_op_t();
+        op->bs_op->opcode = BS_OP_SYNC;
+        op->bs_op->callback = [this, ps, op, role_osd](blockstore_op_t *bs_op)
+        {
+            if (bs_op->retval < 0)
+            {
+                printf("Local OP_SYNC failed: %d (%s)\n", bs_op->retval, strerror(-bs_op->retval));
+                force_stop(1);
+                return;
+            }
+            add_bs_subop_stats(op);
+            delete op->bs_op;
+            op->bs_op = NULL;
+            delete op;
+            ps->list_ops.erase(role_osd);
+            submit_list_subop(role_osd, ps);
+        };
+        bs->enqueue_op(op->bs_op);
+        ps->list_ops[role_osd] = op;
+    }
+    else
+    {
+        // Peer
+        auto & cl = c_cli.clients.at(c_cli.osd_peer_fds[role_osd]);
+        osd_op_t *op = new osd_op_t();
+        op->op_type = OSD_OP_OUT;
+        op->peer_fd = cl.peer_fd;
+        op->req = {
+            .sec_sync = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = c_cli.next_subop_id++,
+                    .opcode = OSD_OP_SEC_SYNC,
+                },
+            },
+        };
+        op->callback = [this, ps, role_osd](osd_op_t *op)
+        {
+            if (op->reply.hdr.retval < 0)
+            {
+                // FIXME: Mark peer as failed and don't reconnect immediately after dropping the connection
+                printf("Failed to sync OSD %lu: %ld (%s), disconnecting peer\n", role_osd, op->reply.hdr.retval, strerror(-op->reply.hdr.retval));
+                ps->list_ops.erase(role_osd);
+                c_cli.stop_client(op->peer_fd);
+                delete op;
+                return;
+            }
+            delete op;
+            ps->list_ops.erase(role_osd);
+            submit_list_subop(role_osd, ps);
+        };
+        c_cli.outbox_push(op);
+        ps->list_ops[role_osd] = op;
+    }
+}
+
+void osd_t::submit_list_subop(osd_num_t role_osd, pg_peering_state_t *ps)
+{
+    if (role_osd == this->osd_num)
+    {
+        // Self
+        osd_op_t *op = new osd_op_t();
+        op->op_type = 0;
+        op->peer_fd = 0;
+        clock_gettime(CLOCK_REALTIME, &op->tv_begin);
+        op->bs_op = new blockstore_op_t();
+        op->bs_op->opcode = BS_OP_LIST;
+        op->bs_op->oid.stripe = st_cli.pool_config[ps->pool_id].pg_stripe_size;
+        op->bs_op->oid.inode = ((uint64_t)ps->pool_id << (64 - POOL_ID_BITS));
+        op->bs_op->version = ((uint64_t)(ps->pool_id+1) << (64 - POOL_ID_BITS)) - 1;
+        op->bs_op->len = pg_counts[ps->pool_id];
+        op->bs_op->offset = ps->pg_num-1;
+        op->bs_op->callback = [this, ps, op, role_osd](blockstore_op_t *bs_op)
+        {
+            if (op->bs_op->retval < 0)
+            {
+                throw std::runtime_error("local OP_LIST failed");
+            }
+            add_bs_subop_stats(op);
+            printf(
+                "[PG %u] Got object list from OSD %lu (local): %d object versions (%lu of them stable)\n",
+                ps->pg_num, role_osd, bs_op->retval, bs_op->version
+            );
+            ps->list_results[role_osd] = {
+                .buf = (obj_ver_id*)op->bs_op->buf,
+                .total_count = (uint64_t)op->bs_op->retval,
+                .stable_count = op->bs_op->version,
+            };
+            ps->list_ops.erase(role_osd);
+            delete op->bs_op;
+            op->bs_op = NULL;
+            delete op;
+        };
+        bs->enqueue_op(op->bs_op);
+        ps->list_ops[role_osd] = op;
+    }
+    else
+    {
+        // Peer
+        osd_op_t *op = new osd_op_t();
+        op->op_type = OSD_OP_OUT;
+        op->peer_fd = c_cli.osd_peer_fds[role_osd];
+        op->req = {
+            .sec_list = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = c_cli.next_subop_id++,
+                    .opcode = OSD_OP_SEC_LIST,
+                },
+                .list_pg = ps->pg_num,
+                .pg_count = pg_counts[ps->pool_id],
+                .pg_stripe_size = st_cli.pool_config[ps->pool_id].pg_stripe_size,
+                .min_inode = ((uint64_t)(ps->pool_id) << (64 - POOL_ID_BITS)),
+                .max_inode = ((uint64_t)(ps->pool_id+1) << (64 - POOL_ID_BITS)) - 1,
+            },
+        };
+        op->callback = [this, ps, role_osd](osd_op_t *op)
+        {
+            if (op->reply.hdr.retval < 0)
+            {
+                printf("Failed to get object list from OSD %lu (retval=%ld), disconnecting peer\n", role_osd, op->reply.hdr.retval);
+                ps->list_ops.erase(role_osd);
+                c_cli.stop_client(op->peer_fd);
+                delete op;
+                return;
+            }
+            printf(
+                "[PG %u] Got object list from OSD %lu: %ld object versions (%lu of them stable)\n",
+                ps->pg_num, role_osd, op->reply.hdr.retval, op->reply.sec_list.stable_count
+            );
+            ps->list_results[role_osd] = {
+                .buf = (obj_ver_id*)op->buf,
+                .total_count = (uint64_t)op->reply.hdr.retval,
+                .stable_count = op->reply.sec_list.stable_count,
+            };
+            // set op->buf to NULL so it doesn't get freed
+            op->buf = NULL;
+            ps->list_ops.erase(role_osd);
+            delete op;
+        };
+        c_cli.outbox_push(op);
+        ps->list_ops[role_osd] = op;
+    }
+}
+
+void osd_t::discard_list_subop(osd_op_t *list_op)
+{
+    if (list_op->peer_fd == 0)
+    {
+        // Self
+        list_op->bs_op->callback = [list_op](blockstore_op_t *bs_op)
+        {
+            if (list_op->bs_op->buf)
+                free(list_op->bs_op->buf);
+            delete list_op->bs_op;
+            list_op->bs_op = NULL;
+            delete list_op;
+        };
+    }
+    else
+    {
+        // Peer
+        list_op->callback = [](osd_op_t *list_op)
+        {
+            delete list_op;
+        };
+    }
+}
+
+bool osd_t::stop_pg(pg_t & pg)
+{
+    if (pg.peering_state)
+    {
+        // Stop peering
+        for (auto it = pg.peering_state->list_ops.begin(); it != pg.peering_state->list_ops.end();)
+        {
+            discard_list_subop(it->second);
+        }
+        for (auto it = pg.peering_state->list_results.begin(); it != pg.peering_state->list_results.end();)
+        {
+            if (it->second.buf)
+            {
+                free(it->second.buf);
+            }
+        }
+        delete pg.peering_state;
+        pg.peering_state = NULL;
+    }
+    if (!(pg.state & PG_ACTIVE))
+    {
+        return false;
+    }
+    pg.state = pg.state & ~PG_ACTIVE | PG_STOPPING;
+    if (pg.inflight == 0 && !pg.flush_batch)
+    {
+        finish_stop_pg(pg);
+    }
+    else
+    {
+        report_pg_state(pg);
+    }
+    return true;
+}
+
+void osd_t::finish_stop_pg(pg_t & pg)
+{
+    pg.state = PG_OFFLINE;
+    report_pg_state(pg);
+}
+
+void osd_t::report_pg_state(pg_t & pg)
+{
+    pg.print_state();
+    this->pg_state_dirty.insert({ .pool_id = pg.pool_id, .pg_num = pg.pg_num });
+    if (pg.state == PG_ACTIVE && (pg.target_history.size() > 0 || pg.all_peers.size() > pg.target_set.size()))
+    {
+        // Clear history of active+clean PGs
+        pg.history_changed = true;
+        pg.target_history.clear();
+        pg.all_peers = pg.target_set;
+        pg.cur_peers = pg.target_set;
+    }
+    else if (pg.state == (PG_ACTIVE|PG_LEFT_ON_DEAD))
+    {
+        // Clear history of active+left_on_dead PGs, but leave dead OSDs in all_peers
+        pg.history_changed = true;
+        pg.target_history.clear();
+        std::set<osd_num_t> dead_peers;
+        for (auto pg_osd: pg.all_peers)
+        {
+            dead_peers.insert(pg_osd);
+        }
+        for (auto pg_osd: pg.cur_peers)
+        {
+            dead_peers.erase(pg_osd);
+        }
+        for (auto pg_osd: pg.target_set)
+        {
+            if (pg_osd)
+            {
+                dead_peers.insert(pg_osd);
+            }
+        }
+        pg.all_peers.clear();
+        pg.all_peers.insert(pg.all_peers.begin(), dead_peers.begin(), dead_peers.end());
+        pg.cur_peers.clear();
+        for (auto pg_osd: pg.target_set)
+        {
+            if (pg_osd)
+            {
+                pg.cur_peers.push_back(pg_osd);
+            }
+        }
+    }
+    if (pg.state == PG_OFFLINE && !this->pg_config_applied)
+    {
+        apply_pg_config();
+    }
+    report_pg_states();
+}

osd_peering_pg.cpp

@@ -1,159 +1,420 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "osd_peering_pg.h"
 
-void pg_t::remember_object(pg_obj_state_check_t &st, std::vector<obj_ver_role> &all)
+struct obj_ver_role
 {
-    auto & pg = *this;
-    // Remember the decision
-    uint64_t state = 0;
-    if (st.n_roles == pg.pg_cursize)
+    object_id oid;
+    uint64_t version;
+    uint64_t osd_num;
+    bool is_stable;
+};
+
+inline bool operator < (const obj_ver_role & a, const obj_ver_role & b)
+{
+    // ORDER BY inode ASC, stripe & ~STRIPE_MASK ASC, version DESC, role ASC, osd_num ASC
+    return a.oid.inode < b.oid.inode || a.oid.inode == b.oid.inode && (
+        (a.oid.stripe & ~STRIPE_MASK) < (b.oid.stripe & ~STRIPE_MASK) ||
+        (a.oid.stripe & ~STRIPE_MASK) == (b.oid.stripe & ~STRIPE_MASK) && (
+            a.version > b.version ||
+            a.version == b.version && (
+                a.oid.stripe < b.oid.stripe ||
+                a.oid.stripe == b.oid.stripe && a.osd_num < b.osd_num
+            )
+        )
+    );
+}
+
+struct obj_piece_ver_t
+{
+    uint64_t max_ver = 0;
+    uint64_t stable_ver = 0;
+    uint64_t max_target = 0;
+};
+
+struct pg_obj_state_check_t
+{
+    pg_t *pg;
+    bool replicated = false;
+    std::vector<obj_ver_role> list;
+    int list_pos;
+    int obj_start = 0, obj_end = 0, ver_start = 0, ver_end = 0;
+    object_id oid = { 0 };
+    uint64_t max_ver = 0;
+    uint64_t last_ver = 0;
+    uint64_t target_ver = 0;
+    uint64_t n_copies = 0, has_roles = 0, n_roles = 0, n_stable = 0, n_mismatched = 0;
+    uint64_t n_unstable = 0, n_invalid = 0;
+    pg_osd_set_t osd_set;
+    int log_level;
+
+    void walk();
+    void start_object();
+    void handle_version();
+    void finish_object();
+};
+
+void pg_obj_state_check_t::walk()
+{
+    pg->clean_count = 0;
+    pg->total_count = 0;
+    pg->state = 0;
+    for (list_pos = 0; list_pos < list.size(); list_pos++)
     {
-        if (st.n_matched == pg.pg_cursize)
-            state = OBJ_CLEAN;
+        if (oid.inode != list[list_pos].oid.inode ||
+            oid.stripe != (list[list_pos].oid.stripe & ~STRIPE_MASK))
+        {
+            if (oid.inode != 0)
+            {
+                finish_object();
+            }
+            start_object();
+        }
+        handle_version();
+    }
+    if (oid.inode != 0)
+    {
+        finish_object();
+    }
+    if (pg->state & PG_HAS_INVALID)
+    {
+        // Stop PGs with "invalid" objects
+        pg->state = PG_INCOMPLETE | PG_HAS_INVALID;
+        return;
+    }
+    if (pg->pg_cursize < pg->pg_size)
+    {
+        pg->state |= PG_DEGRADED;
+    }
+    pg->state |= PG_ACTIVE;
+    if (pg->state == PG_ACTIVE && pg->cur_peers.size() < pg->all_peers.size())
+    {
+        pg->state |= PG_LEFT_ON_DEAD;
+    }
+}
+
+void pg_obj_state_check_t::start_object()
+{
+    obj_start = list_pos;
+    oid = { .inode = list[list_pos].oid.inode, .stripe = list[list_pos].oid.stripe & ~STRIPE_MASK };
+    last_ver = max_ver = list[list_pos].version;
+    target_ver = 0;
+    ver_start = list_pos;
+    has_roles = n_copies = n_roles = n_stable = n_mismatched = 0;
+    n_unstable = n_invalid = 0;
+}
+
+void pg_obj_state_check_t::handle_version()
+{
+    if (!target_ver && last_ver != list[list_pos].version && (n_stable > 0 || n_roles >= pg->pg_minsize))
+    {
+        // Version is either stable or recoverable
+        target_ver = last_ver;
+        ver_end = list_pos;
+    }
+    if (!target_ver)
+    {
+        if (last_ver != list[list_pos].version)
+        {
+            ver_start = list_pos;
+            has_roles = n_copies = n_roles = n_stable = n_mismatched = 0;
+            last_ver = list[list_pos].version;
+        }
+        unsigned replica = (list[list_pos].oid.stripe & STRIPE_MASK);
+        n_copies++;
+        if (replicated && replica > 0 || replica >= pg->pg_size)
+        {
+            n_invalid++;
+        }
         else
         {
-            state = OBJ_MISPLACED;
-            pg.state = pg.state | PG_HAS_MISPLACED;
+            if (list[list_pos].is_stable)
+            {
+                n_stable++;
+            }
+            if (replicated)
+            {
+                int i;
+                for (i = 0; i < pg->cur_set.size(); i++)
+                {
+                    if (pg->cur_set[i] == list[list_pos].osd_num)
+                    {
+                        break;
+                    }
+                }
+                if (i == pg->cur_set.size())
+                {
+                    n_mismatched++;
+                }
+            }
+            else
+            {
+                if (pg->cur_set[replica] != list[list_pos].osd_num)
+                {
+                    n_mismatched++;
+                }
+                if (!(has_roles & (1 << replica)))
+                {
+                    has_roles = has_roles | (1 << replica);
+                    n_roles++;
+                }
+            }
         }
     }
-    else if (st.n_roles < pg.pg_minsize)
+    if (!list[list_pos].is_stable)
     {
-        printf("Object is unfound: inode=%lu stripe=%lu version=%lu/%lu\n", st.oid.inode, st.oid.stripe, st.target_ver, st.max_ver);
+        n_unstable++;
+    }
+}
+
+void pg_obj_state_check_t::finish_object()
+{
+    if (!target_ver && (n_stable > 0 || n_roles >= pg->pg_minsize))
+    {
+        // Version is either stable or recoverable
+        target_ver = last_ver;
+        ver_end = list_pos;
+    }
+    obj_end = list_pos;
+    // Remember the decision
+    uint64_t state = 0;
+    if (n_invalid > 0)
+    {
+        // It's not allowed to change the replication scheme for a pool other than by recreating it
+        // So we must bring the PG offline
         state = OBJ_INCOMPLETE;
-        pg.state = pg.state | PG_HAS_UNFOUND;
+        pg->state |= PG_HAS_INVALID;
+        pg->total_count++;
+        return;
+    }
+    if (n_unstable > 0)
+    {
+        pg->state |= PG_HAS_UNCLEAN;
+        std::unordered_map<obj_piece_id_t, obj_piece_ver_t> pieces;
+        for (int i = obj_start; i < obj_end; i++)
+        {
+            auto & pcs = pieces[(obj_piece_id_t){ .oid = list[i].oid, .osd_num = list[i].osd_num }];
+            if (!pcs.max_ver)
+            {
+                pcs.max_ver = list[i].version;
+            }
+            if (list[i].is_stable && !pcs.stable_ver)
+            {
+                pcs.stable_ver = list[i].version;
+            }
+            if (list[i].version <= target_ver && !pcs.max_target)
+            {
+                pcs.max_target = list[i].version;
+            }
+        }
+        for (auto pp: pieces)
+        {
+            auto & pcs = pp.second;
+            if (pcs.stable_ver < pcs.max_ver)
+            {
+                auto & act = pg->flush_actions[pp.first];
+                // osd_set doesn't include rollback/stable states, so don't include them in the state code either
+                if (pcs.max_ver > target_ver)
+                {
+                    act.rollback = true;
+                    act.rollback_to = pcs.max_target;
+                }
+                if (pcs.stable_ver < (pcs.max_ver > target_ver ? pcs.max_target : pcs.max_ver))
+                {
+                    act.make_stable = true;
+                    act.stable_to = pcs.max_ver > target_ver ? pcs.max_target : pcs.max_ver;
+                }
+            }
+        }
+    }
+    if (!target_ver)
+    {
+        return;
+    }
+    if (!replicated && n_roles < pg->pg_minsize)
+    {
+        if (log_level > 1)
+        {
+            printf("Object is incomplete: inode=%lu stripe=%lu version=%lu/%lu\n", oid.inode, oid.stripe, target_ver, max_ver);
+        }
+        state = OBJ_INCOMPLETE;
+        pg->state = pg->state | PG_HAS_INCOMPLETE;
+    }
+    else if ((replicated ? n_copies : n_roles) < pg->pg_cursize)
+    {
+        if (log_level > 1)
+        {
+            printf("Object is degraded: inode=%lu stripe=%lu version=%lu/%lu\n", oid.inode, oid.stripe, target_ver, max_ver);
+        }
+        state = OBJ_DEGRADED;
+        pg->state = pg->state | PG_HAS_DEGRADED;
+    }
+    else if (n_mismatched > 0)
+    {
+        if (log_level > 1 && (replicated || n_roles >= pg->pg_cursize))
+        {
+            printf("Object is misplaced: inode=%lu stripe=%lu version=%lu/%lu\n", oid.inode, oid.stripe, target_ver, max_ver);
+        }
+        state |= OBJ_MISPLACED;
+        pg->state = pg->state | PG_HAS_MISPLACED;
+    }
+    if (log_level > 1 && ((replicated ? n_copies : n_roles) < pg->pg_cursize || n_mismatched > 0))
+    {
+        if (log_level > 2)
+        {
+            for (int i = obj_start; i < obj_end; i++)
+            {
+                printf("v%lu present on: osd %lu, role %ld%s\n", list[i].version, list[i].osd_num,
+                    (list[i].oid.stripe & STRIPE_MASK), list[i].is_stable ? " (stable)" : "");
+            }
+        }
+        else
+        {
+            for (int i = ver_start; i < ver_end; i++)
+            {
+                printf("Target version present on: osd %lu, role %ld%s\n", list[i].osd_num,
+                    (list[i].oid.stripe & STRIPE_MASK), list[i].is_stable ? " (stable)" : "");
+            }
+        }
+    }
+    pg->total_count++;
+    if (state != 0 || ver_end < obj_end)
+    {
+        osd_set.clear();
+        for (int i = ver_start; i < ver_end; i++)
+        {
+            osd_set.push_back((pg_obj_loc_t){
+                .role = (list[i].oid.stripe & STRIPE_MASK),
+                .osd_num = list[i].osd_num,
+                .outdated = false,
+            });
+        }
+    }
+    if (ver_end < obj_end)
+    {
+        // Check for outdated versions not present in the current target OSD set
+        for (int i = ver_end; i < obj_end; i++)
+        {
+            int j;
+            for (j = 0; j < osd_set.size(); j++)
+            {
+                if (osd_set[j].osd_num == list[i].osd_num)
+                {
+                    break;
+                }
+            }
+            if (j >= osd_set.size() && pg->cur_set[list[i].oid.stripe & STRIPE_MASK] != list[i].osd_num)
+            {
+                osd_set.push_back((pg_obj_loc_t){
+                    .role = (list[i].oid.stripe & STRIPE_MASK),
+                    .osd_num = list[i].osd_num,
+                    .outdated = true,
+                });
+                if (!(state & (OBJ_INCOMPLETE | OBJ_DEGRADED)))
+                {
+                    state |= OBJ_MISPLACED;
+                    pg->state = pg->state | PG_HAS_MISPLACED;
+                }
+            }
+        }
+    }
+    if (target_ver < max_ver)
+    {
+        pg->ver_override[oid] = target_ver;
+    }
+    if (state == 0)
+    {
+        pg->clean_count++;
     }
     else
     {
-        printf("Object is degraded: inode=%lu stripe=%lu version=%lu/%lu\n", st.oid.inode, st.oid.stripe, st.target_ver, st.max_ver);
-        state = OBJ_DEGRADED;
-        pg.state = pg.state | PG_HAS_DEGRADED;
-    }
-    if (st.n_copies > pg.pg_size)
-    {
-        state |= OBJ_OVERCOPIED;
-        pg.state = pg.state | PG_HAS_UNCLEAN;
-    }
-    if (st.n_stable < st.n_copies)
-    {
-        state |= OBJ_NEEDS_STABLE;
-        pg.state = pg.state | PG_HAS_UNCLEAN;
-    }
-    if (st.target_ver < st.max_ver || st.has_old_unstable)
-    {
-        state |= OBJ_NEEDS_ROLLBACK;
-        pg.state = pg.state | PG_HAS_UNCLEAN;
-        pg.ver_override[st.oid] = st.target_ver;
-    }
-    if (st.is_buggy)
-    {
-        state |= OBJ_BUGGY;
-        // FIXME: bring pg offline
-        throw std::runtime_error("buggy object state");
-    }
-    if (state != OBJ_CLEAN)
-    {
-        st.osd_set.clear();
-        for (int i = st.ver_start; i < st.ver_end; i++)
-        {
-            st.osd_set.push_back((pg_obj_loc_t){
-                .role = (all[i].oid.stripe & STRIPE_MASK),
-                .osd_num = all[i].osd_num,
-                .stable = all[i].is_stable,
-            });
-        }
-        std::sort(st.osd_set.begin(), st.osd_set.end());
-        auto it = pg.state_dict.find(st.osd_set);
-        if (it == pg.state_dict.end())
+        auto it = pg->state_dict.find(osd_set);
+        if (it == pg->state_dict.end())
         {
             std::vector<uint64_t> read_target;
-            read_target.resize(pg.pg_size);
-            for (int i = 0; i < pg.pg_size; i++)
+            if (replicated)
             {
-                read_target[i] = 0;
+                for (auto & o: osd_set)
+                {
+                    if (!o.outdated)
+                    {
+                        read_target.push_back(o.osd_num);
+                    }
+                }
+                while (read_target.size() < pg->pg_size)
+                {
+                    // FIXME: This is because we then use .data() and assume it's at least <pg_size> long
+                    read_target.push_back(0);
+                }
             }
-            for (auto & o: st.osd_set)
+            else
             {
-                read_target[o.role] = o.osd_num;
+                read_target.resize(pg->pg_size);
+                for (int i = 0; i < pg->pg_size; i++)
+                {
+                    read_target[i] = 0;
+                }
+                for (auto & o: osd_set)
+                {
+                    if (!o.outdated)
+                    {
+                        read_target[o.role] = o.osd_num;
+                    }
+                }
             }
-            pg.state_dict[st.osd_set] = {
+            pg->state_dict[osd_set] = {
                 .read_target = read_target,
-                .osd_set = st.osd_set,
+                .osd_set = osd_set,
                 .state = state,
                 .object_count = 1,
             };
-            it = pg.state_dict.find(st.osd_set);
+            it = pg->state_dict.find(osd_set);
         }
         else
         {
             it->second.object_count++;
         }
-        pg.obj_states[st.oid] = &it->second;
-        if (st.target_ver < st.max_ver)
+        if (state & OBJ_INCOMPLETE)
         {
-            pg.ver_override[st.oid] = st.target_ver;
+            pg->incomplete_objects[oid] = &it->second;
         }
-        if (state & (OBJ_NEEDS_ROLLBACK | OBJ_NEEDS_STABLE))
+        else if (state & OBJ_DEGRADED)
         {
-            spp::sparse_hash_map<obj_piece_id_t, obj_piece_ver_t> pieces;
-            for (int i = st.obj_start; i < st.obj_end; i++)
-            {
-                auto & pcs = pieces[(obj_piece_id_t){ .oid = all[i].oid, .osd_num = all[i].osd_num }];
-                if (!pcs.max_ver)
-                {
-                    pcs.max_ver = all[i].version;
-                }
-                if (all[i].is_stable && !pcs.stable_ver)
-                {
-                    pcs.stable_ver = all[i].version;
-                }
-            }
-            for (auto pp: pieces)
-            {
-                auto & pcs = pp.second;
-                if (pcs.stable_ver < pcs.max_ver)
-                {
-                    auto & act = obj_stab_actions[pp.first];
-                    if (pcs.max_ver > st.target_ver)
-                    {
-                        act.rollback = true;
-                        act.rollback_to = st.target_ver;
-                    }
-                    else if (pcs.max_ver < st.target_ver && pcs.stable_ver < pcs.max_ver)
-                    {
-                        act.rollback = true;
-                        act.rollback_to = pcs.stable_ver;
-                    }
-                    if (pcs.max_ver >= st.target_ver && pcs.stable_ver < st.target_ver)
-                    {
-                        act.make_stable = true;
-                        act.stable_to = st.target_ver;
-                    }
-                }
-            }
+            pg->degraded_objects[oid] = &it->second;
+        }
+        else
+        {
+            pg->misplaced_objects[oid] = &it->second;
         }
     }
-    else
-        pg.clean_count++;
-    pg.total_count++;
 }
 
 // FIXME: Write at least some tests for this function
-void pg_t::calc_object_states()
+void pg_t::calc_object_states(int log_level)
 {
-    auto & pg = *this;
     // Copy all object lists into one array
-    std::vector<obj_ver_role> all;
-    auto ps = pg.peering_state;
+    pg_obj_state_check_t st;
+    st.log_level = log_level;
+    st.pg = this;
+    st.replicated = (this->scheme == POOL_SCHEME_REPLICATED);
+    auto ps = peering_state;
+    epoch = 0;
     for (auto it: ps->list_results)
     {
         auto nstab = it.second.stable_count;
         auto n = it.second.total_count;
         auto osd_num = it.first;
-        uint64_t start = all.size();
-        all.resize(start + n);
+        uint64_t start = st.list.size();
+        st.list.resize(start + n);
         obj_ver_id *ov = it.second.buf;
         for (uint64_t i = 0; i < n; i++, ov++)
         {
-            all[start+i] = {
+            if ((ov->version >> (64-PG_EPOCH_BITS)) > epoch)
+            {
+                epoch = (ov->version >> (64-PG_EPOCH_BITS));
+            }
+            st.list[start+i] = {
                 .oid = ov->oid,
                 .version = ov->version,
                 .osd_num = osd_num,
@@ -165,101 +426,33 @@ void pg_t::calc_object_states()
     }
     ps->list_results.clear();
     // Sort
-    std::sort(all.begin(), all.end());
+    std::sort(st.list.begin(), st.list.end());
     // Walk over it and check object states
-    pg.clean_count = 0;
-    pg.total_count = 0;
-    pg.state = 0;
-    int replica = 0;
-    pg_obj_state_check_t st;
-    for (int i = 0; i < all.size(); i++)
+    st.walk();
+    if (this->state & (PG_DEGRADED|PG_LEFT_ON_DEAD))
     {
-        if (st.oid.inode != all[i].oid.inode ||
-            st.oid.stripe != (all[i].oid.stripe & ~STRIPE_MASK))
-        {
-            if (st.oid.inode != 0)
-            {
-                // Remember object state
-                st.obj_end = st.ver_end = i;
-                remember_object(st, all);
-            }
-            st.obj_start = st.ver_start = i;
-            st.oid = { .inode = all[i].oid.inode, .stripe = all[i].oid.stripe & ~STRIPE_MASK };
-            st.max_ver = st.target_ver = all[i].version;
-            st.has_roles = st.n_copies = st.n_roles = st.n_stable = st.n_matched = 0;
-            st.is_buggy = st.has_old_unstable = false;
-        }
-        else if (st.target_ver != all[i].version)
-        {
-            if (st.n_stable > 0 || st.n_roles >= pg.pg_minsize)
-            {
-                // Last processed version is either recoverable or stable, choose it as target and skip previous versions
-                st.ver_end = i;
-                i++;
-                while (i < all.size() && st.oid.inode == all[i].oid.inode &&
-                    st.oid.stripe == (all[i].oid.stripe & ~STRIPE_MASK))
-                {
-                    if (!all[i].is_stable)
-                    {
-                        st.has_old_unstable = true;
-                    }
-                    i++;
-                }
-                st.obj_end = i;
-                i--;
-                continue;
-            }
-            else
-            {
-                // Last processed version is unstable and unrecoverable
-                // We'll know that because target_ver < max_ver
-                st.ver_start = i;
-                st.target_ver = all[i].version;
-                st.has_roles = st.n_copies = st.n_roles = st.n_stable = st.n_matched = 0;
-            }
-        }
-        replica = (all[i].oid.stripe & STRIPE_MASK);
-        st.n_copies++;
-        if (replica >= pg.pg_size)
-        {
-            // FIXME In the future, check it against the PG epoch number to handle replication factor/scheme changes
-            st.is_buggy = true;
-        }
-        else
-        {
-            if (all[i].is_stable)
-            {
-                st.n_stable++;
-            }
-            if (pg.cur_set[replica] == all[i].osd_num)
-            {
-                st.n_matched++;
-            }
-            if (!(st.has_roles & (1 << replica)))
-            {
-                st.has_roles = st.has_roles | (1 << replica);
-                st.n_roles++;
-            }
-        }
+        assert(epoch != ((1ul << PG_EPOCH_BITS)-1));
+        epoch++;
     }
-    if (st.oid.inode != 0)
-    {
-        // Remember object state
-        st.obj_end = st.ver_end = all.size();
-        remember_object(st, all);
-    }
-    if (pg.pg_cursize < pg.pg_size)
-    {
-        pg.state = pg.state | PG_DEGRADED;
-    }
-    printf(
-        "PG %u is active%s%s%s%s%s (%lu objects)\n", pg.pg_num,
-        (pg.state & PG_DEGRADED) ? " + degraded" : "",
-        (pg.state & PG_HAS_UNFOUND) ? " + has_unfound" : "",
-        (pg.state & PG_HAS_DEGRADED) ? " + has_degraded" : "",
-        (pg.state & PG_HAS_MISPLACED) ? " + has_misplaced" : "",
-        (pg.state & PG_HAS_UNCLEAN) ? " + has_unclean" : "",
-        pg.total_count
-    );
-    pg.state = pg.state | PG_ACTIVE;
+}
+
+void pg_t::print_state()
+{
+    printf(
+        "[PG %u] is %s%s%s%s%s%s%s%s%s%s%s%s%s (%lu objects)\n", pg_num,
+        (state & PG_STARTING) ? "starting" : "",
+        (state & PG_OFFLINE) ? "offline" : "",
+        (state & PG_PEERING) ? "peering" : "",
+        (state & PG_INCOMPLETE) ? "incomplete" : "",
+        (state & PG_ACTIVE) ? "active" : "",
+        (state & PG_STOPPING) ? "stopping" : "",
+        (state & PG_DEGRADED) ? " + degraded" : "",
+        (state & PG_HAS_INCOMPLETE) ? " + has_incomplete" : "",
+        (state & PG_HAS_DEGRADED) ? " + has_degraded" : "",
+        (state & PG_HAS_MISPLACED) ? " + has_misplaced" : "",
+        (state & PG_HAS_UNCLEAN) ? " + has_unclean" : "",
+        (state & PG_HAS_INVALID) ? " + has_invalid" : "",
+        (state & PG_LEFT_ON_DEAD) ? " + left_on_dead" : "",
+        total_count
+    );
 }

osd_peering_pg.h

@@ -1,43 +1,24 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <map>
+#include <unordered_map>
 #include <vector>
 #include <algorithm>
 
+#include "cpp-btree/btree_map.h"
+
 #include "object_id.h"
 #include "osd_ops.h"
+#include "pg_states.h"
 
-#include "sparsepp/sparsepp/spp.h"
-
-// Placement group states
-// Exactly one of these:
-#define PG_OFFLINE (1<<0)
-#define PG_PEERING (1<<1)
-#define PG_INCOMPLETE (1<<2)
-#define PG_ACTIVE (1<<3)
-// Plus any of these:
-#define PG_DEGRADED (1<<4)
-#define PG_HAS_UNFOUND (1<<5)
-#define PG_HAS_DEGRADED (1<<6)
-#define PG_HAS_MISPLACED (1<<7)
-#define PG_HAS_UNCLEAN (1<<8)
-
-// FIXME: Safe default that doesn't depend on parity_block_size of pg_parity_size
-#define STRIPE_MASK ((uint64_t)4096 - 1)
-
-// OSD object states
-#define OBJ_CLEAN 0x01
-#define OBJ_MISPLACED 0x02
-#define OBJ_DEGRADED 0x03
-#define OBJ_INCOMPLETE 0x04
-#define OBJ_NEEDS_STABLE 0x10000
-#define OBJ_NEEDS_ROLLBACK 0x20000
-#define OBJ_OVERCOPIED 0x40000
-#define OBJ_BUGGY 0x80000
+#define PG_EPOCH_BITS 48
 
 struct pg_obj_loc_t
 {
     uint64_t role;
     osd_num_t osd_num;
-    bool stable;
+    bool outdated;
 };
 
 typedef std::vector<pg_obj_loc_t> pg_osd_set_t;
@@ -64,28 +45,10 @@ struct osd_op_t;
 struct pg_peering_state_t
 {
     // osd_num -> list result
-    spp::sparse_hash_map<osd_num_t, osd_op_t*> list_ops;
-    spp::sparse_hash_map<osd_num_t, pg_list_result_t> list_results;
-    int list_done = 0;
-};
-
-struct pg_obj_state_check_t
-{
-    int obj_start = 0, obj_end = 0, ver_start = 0, ver_end = 0;
-    object_id oid = { 0 };
-    uint64_t max_ver = 0;
-    uint64_t target_ver = 0;
-    uint64_t n_copies = 0, has_roles = 0, n_roles = 0, n_stable = 0, n_matched = 0;
-    bool is_buggy = false, has_old_unstable = false;
-    pg_osd_set_t osd_set;
-};
-
-struct obj_ver_role
-{
-    object_id oid;
-    uint64_t version;
-    uint64_t osd_num;
-    bool is_stable;
+    std::unordered_map<osd_num_t, osd_op_t*> list_ops;
+    std::unordered_map<osd_num_t, pg_list_result_t> list_results;
+    pool_id_t pool_id = 0;
+    pg_num_t pg_num = 0;
 };
 
 struct obj_piece_id_t
@@ -94,60 +57,67 @@ struct obj_piece_id_t
     uint64_t osd_num;
 };
 
-struct obj_piece_ver_t
-{
-    uint64_t max_ver = 0;
-    uint64_t stable_ver = 0;
-};
-
-struct obj_stab_action_t
+struct flush_action_t
 {
     bool rollback = false, make_stable = false;
     uint64_t stable_to = 0, rollback_to = 0;
+    bool submitted = false;
+};
+
+struct pg_flush_batch_t
+{
+    std::map<osd_num_t, std::vector<obj_ver_id>> rollback_lists;
+    std::map<osd_num_t, std::vector<obj_ver_id>> stable_lists;
+    int flush_ops = 0, flush_done = 0;
+    int flush_objects = 0;
 };
 
 struct pg_t
 {
-    int state;
-    uint64_t pg_cursize = 3, pg_size = 3, pg_minsize = 2;
-    pg_num_t pg_num;
+    int state = 0;
+    uint64_t scheme = 0;
+    uint64_t pg_cursize = 0, pg_size = 0, pg_minsize = 0;
+    pool_id_t pool_id = 0;
+    pg_num_t pg_num = 0;
     uint64_t clean_count = 0, total_count = 0;
+    // epoch number - should increase with each non-clean activation of the PG
+    uint64_t epoch = 0, reported_epoch = 0;
+    // target history and all potential peers
+    std::vector<std::vector<osd_num_t>> target_history;
+    std::vector<osd_num_t> all_peers;
+    bool history_changed = false;
+    // peer list from the last peering event
+    std::vector<osd_num_t> cur_peers;
     // target_set is the "correct" peer OSD set for this PG
     std::vector<osd_num_t> target_set;
     // cur_set is the current set of connected peer OSDs for this PG
     // cur_set = (role => osd_num or UINT64_MAX if missing). role numbers begin with zero
     std::vector<osd_num_t> cur_set;
+    // same thing in state_dict-like format
+    pg_osd_set_t cur_loc_set;
     // moved object map. by default, each object is considered to reside on the cur_set.
     // this map stores all objects that differ.
     // it may consume up to ~ (raw storage / object size) * 24 bytes in the worst case scenario
     // which is up to ~192 MB per 1 TB in the worst case scenario
     std::map<pg_osd_set_t, pg_osd_set_state_t> state_dict;
-    spp::sparse_hash_map<object_id, pg_osd_set_state_t*> obj_states;
-    std::map<obj_piece_id_t, obj_stab_action_t> obj_stab_actions;
-    spp::sparse_hash_map<object_id, uint64_t> ver_override;
+    btree::btree_map<object_id, pg_osd_set_state_t*> incomplete_objects, misplaced_objects, degraded_objects;
+    std::map<obj_piece_id_t, flush_action_t> flush_actions;
+    btree::btree_map<object_id, uint64_t> ver_override;
     pg_peering_state_t *peering_state = NULL;
+    pg_flush_batch_t *flush_batch = NULL;
 
+    int inflight = 0; // including write_queue
     std::multimap<object_id, osd_op_t*> write_queue;
 
-    void calc_object_states();
-    void remember_object(pg_obj_state_check_t &st, std::vector<obj_ver_role> &all);
+    void calc_object_states(int log_level);
+    void print_state();
 };
 
 inline bool operator < (const pg_obj_loc_t &a, const pg_obj_loc_t &b)
 {
-    return a.role < b.role || a.role == b.role && a.osd_num < b.osd_num ||
-        a.role == b.role && a.osd_num == b.osd_num && a.stable < b.stable;
-}
-
-inline bool operator < (const obj_ver_role & a, const obj_ver_role & b)
-{
-    // ORDER BY inode ASC, stripe & ~STRIPE_MASK ASC, version DESC, osd_num ASC
-    return a.oid.inode < b.oid.inode || a.oid.inode == b.oid.inode && (
-        (a.oid.stripe & ~STRIPE_MASK) < (b.oid.stripe & ~STRIPE_MASK) ||
-        (a.oid.stripe & ~STRIPE_MASK) == (b.oid.stripe & ~STRIPE_MASK) && (
-            a.version > b.version || a.version == b.version && a.osd_num < b.osd_num
-        )
-    );
+    return a.outdated < b.outdated ||
+        a.outdated == b.outdated && a.role < b.role ||
+        a.outdated == b.outdated && a.role == b.role && a.osd_num < b.osd_num;
 }
 
 inline bool operator == (const obj_piece_id_t & a, const obj_piece_id_t & b)
@@ -172,7 +142,6 @@ namespace std
                 // Copy-pasted from spp::hash_combine()
                 seed ^= (e.role + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
                 seed ^= (e.osd_num + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
-                seed ^= ((e.stable ? 1 : 0) + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
             }
             return seed;
         }

osd_peering_pg_test.cpp

@@ -0,0 +1,57 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#define _LARGEFILE64_SOURCE
+
+#include "osd_peering_pg.h"
+#define STRIPE_SHIFT 12
+
+/**
+ * TODO tests for object & pg state calculation.
+ *
+ * 1) pg=1,2,3. objects:
+ *    v1=1s,2s,3s -> clean
+ *    v1=1s,2s,3 v2=1s,2s,_ -> degraded + needs_rollback
+ *    v1=1s,2s,_ -> degraded
+ *    v1=1s,2s,3s v2=1,6,_ -> degraded + needs_stabilize
+ *    v1=2s,1s,3s -> misplaced
+ *    v1=4,5,6 -> misplaced + needs_stabilize
+ *    v1=1s,2s,6s -> misplaced
+ * 2) ...
+ */
+int main(int argc, char *argv[])
+{
+    pg_t pg = {
+        .state = PG_PEERING,
+        .pg_num = 1,
+        .target_set = { 1, 2, 3 },
+        .cur_set = { 1, 2, 3 },
+        .peering_state = new pg_peering_state_t(),
+    };
+    for (uint64_t osd_num = 1; osd_num <= 3; osd_num++)
+    {
+        pg_list_result_t r = {
+            .buf = (obj_ver_id*)malloc_or_die(sizeof(obj_ver_id) * 1024*1024*8),
+            .total_count = 1024*1024*8,
+            .stable_count = (uint64_t)(1024*1024*8 - (osd_num == 1 ? 10 : 0)),
+        };
+        for (uint64_t i = 0; i < r.total_count; i++)
+        {
+            r.buf[i] = {
+                .oid = {
+                    .inode = 1,
+                    .stripe = (i << STRIPE_SHIFT) | (osd_num-1),
+                },
+                .version = (uint64_t)(osd_num == 1 && i >= r.total_count - 10 ? 2 : 1),
+            };
+        }
+        pg.peering_state->list_results[osd_num] = r;
+    }
+    pg.calc_object_states(0);
+    printf("deviation variants=%ld clean=%lu\n", pg.state_dict.size(), pg.clean_count);
+    for (auto it: pg.state_dict)
+    {
+        printf("dev: state=%lx\n", it.second.state);
+    }
+    return 0;
+}

osd_primary.h

@@ -0,0 +1,41 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#pragma once
+
+#include "osd.h"
+#include "osd_rmw.h"
+
+#define SUBMIT_READ 0
+#define SUBMIT_RMW_READ 1
+#define SUBMIT_WRITE 2
+
+struct unstable_osd_num_t
+{
+    osd_num_t osd_num;
+    int start, len;
+};
+
+struct osd_primary_op_data_t
+{
+    int st = 0;
+    pg_num_t pg_num;
+    object_id oid;
+    uint64_t target_ver;
+    uint64_t fact_ver = 0;
+    uint64_t scheme = 0;
+    int n_subops = 0, done = 0, errors = 0, epipe = 0;
+    int degraded = 0, pg_size, pg_minsize;
+    osd_rmw_stripe_t *stripes;
+    osd_op_t *subops = NULL;
+    uint64_t *prev_set = NULL;
+    pg_osd_set_state_t *object_state = NULL;
+
+    // for sync. oops, requires freeing
+    std::vector<unstable_osd_num_t> *unstable_write_osds = NULL;
+    pool_pg_num_t *dirty_pgs = NULL;
+    int dirty_pg_count = 0;
+    osd_num_t *dirty_osds = NULL;
+    int dirty_osd_count = 0;
+    obj_ver_id *unstable_writes = NULL;
+};

osd_primary_subops.cpp

@@ -0,0 +1,575 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include "osd_primary.h"
+
+void osd_t::autosync()
+{
+    // FIXME Autosync based on the number of unstable writes to prevent
+    // "journal_sector_buffer_count is too low for this batch" errors
+    if (immediate_commit != IMMEDIATE_ALL && !autosync_op)
+    {
+        autosync_op = new osd_op_t();
+        autosync_op->op_type = OSD_OP_IN;
+        autosync_op->req = {
+            .sync = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = 1,
+                    .opcode = OSD_OP_SYNC,
+                },
+            },
+        };
+        autosync_op->callback = [this](osd_op_t *op)
+        {
+            if (op->reply.hdr.retval < 0)
+            {
+                printf("Warning: automatic sync resulted in an error: %ld (%s)\n", -op->reply.hdr.retval, strerror(-op->reply.hdr.retval));
+            }
+            delete autosync_op;
+            autosync_op = NULL;
+        };
+        exec_op(autosync_op);
+    }
+}
+
+void osd_t::finish_op(osd_op_t *cur_op, int retval)
+{
+    inflight_ops--;
+    if (cur_op->op_data)
+    {
+        if (cur_op->op_data->pg_num > 0)
+        {
+            auto & pg = pgs[{ .pool_id = INODE_POOL(cur_op->op_data->oid.inode), .pg_num = cur_op->op_data->pg_num }];
+            pg.inflight--;
+            assert(pg.inflight >= 0);
+            if ((pg.state & PG_STOPPING) && pg.inflight == 0 && !pg.flush_batch)
+            {
+                finish_stop_pg(pg);
+            }
+        }
+        assert(!cur_op->op_data->subops);
+        assert(!cur_op->op_data->unstable_write_osds);
+        assert(!cur_op->op_data->unstable_writes);
+        assert(!cur_op->op_data->dirty_pgs);
+        free(cur_op->op_data);
+        cur_op->op_data = NULL;
+    }
+    if (!cur_op->peer_fd)
+    {
+        // Copy lambda to be unaffected by `delete op`
+        std::function<void(osd_op_t*)>(cur_op->callback)(cur_op);
+    }
+    else
+    {
+        // FIXME add separate magic number
+        auto cl_it = c_cli.clients.find(cur_op->peer_fd);
+        if (cl_it != c_cli.clients.end())
+        {
+            cur_op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
+            cur_op->reply.hdr.id = cur_op->req.hdr.id;
+            cur_op->reply.hdr.opcode = cur_op->req.hdr.opcode;
+            cur_op->reply.hdr.retval = retval;
+            c_cli.outbox_push(cur_op);
+        }
+        else
+        {
+            delete cur_op;
+        }
+    }
+}
+
+void osd_t::submit_primary_subops(int submit_type, uint64_t op_version, int pg_size, const uint64_t* osd_set, osd_op_t *cur_op)
+{
+    bool wr = submit_type == SUBMIT_WRITE;
+    osd_primary_op_data_t *op_data = cur_op->op_data;
+    osd_rmw_stripe_t *stripes = op_data->stripes;
+    bool rep = op_data->scheme == POOL_SCHEME_REPLICATED;
+    // Allocate subops
+    int n_subops = 0, zero_read = -1;
+    for (int role = 0; role < pg_size; role++)
+    {
+        if (osd_set[role] == this->osd_num || osd_set[role] != 0 && zero_read == -1)
+        {
+            zero_read = role;
+        }
+        if (osd_set[role] != 0 && (wr || !rep && stripes[role].read_end != 0))
+        {
+            n_subops++;
+        }
+    }
+    if (!n_subops && (submit_type == SUBMIT_RMW_READ || rep))
+    {
+        n_subops = 1;
+    }
+    else
+    {
+        zero_read = -1;
+    }
+    osd_op_t *subops = new osd_op_t[n_subops];
+    op_data->fact_ver = 0;
+    op_data->done = op_data->errors = 0;
+    op_data->n_subops = n_subops;
+    op_data->subops = subops;
+    int i = 0;
+    for (int role = 0; role < pg_size; role++)
+    {
+        // We always submit zero-length writes to all replicas, even if the stripe is not modified
+        if (!(wr || !rep && stripes[role].read_end != 0 || zero_read == role))
+        {
+            continue;
+        }
+        osd_num_t role_osd_num = osd_set[role];
+        if (role_osd_num != 0)
+        {
+            int stripe_num = rep ? 0 : role;
+            if (role_osd_num == this->osd_num)
+            {
+                clock_gettime(CLOCK_REALTIME, &subops[i].tv_begin);
+                subops[i].op_type = (uint64_t)cur_op;
+                subops[i].bs_op = new blockstore_op_t({
+                    .opcode = (uint64_t)(wr ? (rep ? BS_OP_WRITE_STABLE : BS_OP_WRITE) : BS_OP_READ),
+                    .callback = [subop = &subops[i], this](blockstore_op_t *bs_subop)
+                    {
+                        handle_primary_bs_subop(subop);
+                    },
+                    .oid = {
+                        .inode = op_data->oid.inode,
+                        .stripe = op_data->oid.stripe | stripe_num,
+                    },
+                    .version = op_version,
+                    .offset = wr ? stripes[stripe_num].write_start : stripes[stripe_num].read_start,
+                    .len = wr ? stripes[stripe_num].write_end - stripes[stripe_num].write_start : stripes[stripe_num].read_end - stripes[stripe_num].read_start,
+                    .buf = wr ? stripes[stripe_num].write_buf : stripes[stripe_num].read_buf,
+                });
+#ifdef OSD_DEBUG
+                printf(
+                    "Submit %s to local: %lx:%lx v%lu %u-%u\n", wr ? "write" : "read",
+                    op_data->oid.inode, op_data->oid.stripe | stripe_num, op_version,
+                    subops[i].bs_op->offset, subops[i].bs_op->len
+                );
+#endif
+                bs->enqueue_op(subops[i].bs_op);
+            }
+            else
+            {
+                subops[i].op_type = OSD_OP_OUT;
+                subops[i].peer_fd = c_cli.osd_peer_fds.at(role_osd_num);
+                subops[i].req.sec_rw = {
+                    .header = {
+                        .magic = SECONDARY_OSD_OP_MAGIC,
+                        .id = c_cli.next_subop_id++,
+                        .opcode = (uint64_t)(wr ? (rep ? OSD_OP_SEC_WRITE_STABLE : OSD_OP_SEC_WRITE) : OSD_OP_SEC_READ),
+                    },
+                    .oid = {
+                        .inode = op_data->oid.inode,
+                        .stripe = op_data->oid.stripe | stripe_num,
+                    },
+                    .version = op_version,
+                    .offset = wr ? stripes[stripe_num].write_start : stripes[stripe_num].read_start,
+                    .len = wr ? stripes[stripe_num].write_end - stripes[stripe_num].write_start : stripes[stripe_num].read_end - stripes[stripe_num].read_start,
+                };
+#ifdef OSD_DEBUG
+                printf(
+                    "Submit %s to osd %lu: %lx:%lx v%lu %u-%u\n", wr ? "write" : "read", role_osd_num,
+                    op_data->oid.inode, op_data->oid.stripe | stripe_num, op_version,
+                    subops[i].req.sec_rw.offset, subops[i].req.sec_rw.len
+                );
+#endif
+                if (wr)
+                {
+                    if (stripes[stripe_num].write_end > stripes[stripe_num].write_start)
+                    {
+                        subops[i].iov.push_back(stripes[stripe_num].write_buf, stripes[stripe_num].write_end - stripes[stripe_num].write_start);
+                    }
+                }
+                else
+                {
+                    if (stripes[stripe_num].read_end > stripes[stripe_num].read_start)
+                    {
+                        subops[i].iov.push_back(stripes[stripe_num].read_buf, stripes[stripe_num].read_end - stripes[stripe_num].read_start);
+                    }
+                }
+                subops[i].callback = [cur_op, this](osd_op_t *subop)
+                {
+                    int fail_fd = subop->req.hdr.opcode == OSD_OP_SEC_WRITE &&
+                        subop->reply.hdr.retval != subop->req.sec_rw.len ? subop->peer_fd : -1;
+                    handle_primary_subop(subop, cur_op);
+                    if (fail_fd >= 0)
+                    {
+                        // write operation failed, drop the connection
+                        c_cli.stop_client(fail_fd);
+                    }
+                };
+                c_cli.outbox_push(&subops[i]);
+            }
+            i++;
+        }
+    }
+}
+
+static uint64_t bs_op_to_osd_op[] = {
+    0,
+    OSD_OP_SEC_READ,            // BS_OP_READ = 1
+    OSD_OP_SEC_WRITE,           // BS_OP_WRITE = 2
+    OSD_OP_SEC_WRITE_STABLE,    // BS_OP_WRITE_STABLE = 3
+    OSD_OP_SEC_SYNC,            // BS_OP_SYNC = 4
+    OSD_OP_SEC_STABILIZE,       // BS_OP_STABLE = 5
+    OSD_OP_SEC_DELETE,          // BS_OP_DELETE = 6
+    OSD_OP_SEC_LIST,            // BS_OP_LIST = 7
+    OSD_OP_SEC_ROLLBACK,        // BS_OP_ROLLBACK = 8
+    OSD_OP_TEST_SYNC_STAB_ALL,  // BS_OP_SYNC_STAB_ALL = 9
+};
+
+void osd_t::handle_primary_bs_subop(osd_op_t *subop)
+{
+    osd_op_t *cur_op = (osd_op_t*)subop->op_type;
+    blockstore_op_t *bs_op = subop->bs_op;
+    int expected = bs_op->opcode == BS_OP_READ || bs_op->opcode == BS_OP_WRITE
+        || bs_op->opcode == BS_OP_WRITE_STABLE ? bs_op->len : 0;
+    if (bs_op->retval != expected && bs_op->opcode != BS_OP_READ)
+    {
+        // die
+        throw std::runtime_error(
+            "local blockstore modification failed (opcode = "+std::to_string(bs_op->opcode)+
+            " retval = "+std::to_string(bs_op->retval)+")"
+        );
+    }
+    add_bs_subop_stats(subop);
+    subop->req.hdr.opcode = bs_op_to_osd_op[bs_op->opcode];
+    subop->reply.hdr.retval = bs_op->retval;
+    if (bs_op->opcode == BS_OP_READ || bs_op->opcode == BS_OP_WRITE || bs_op->opcode == BS_OP_WRITE_STABLE)
+    {
+        subop->req.sec_rw.len = bs_op->len;
+        subop->reply.sec_rw.version = bs_op->version;
+    }
+    delete bs_op;
+    subop->bs_op = NULL;
+    handle_primary_subop(subop, cur_op);
+}
+
+void osd_t::add_bs_subop_stats(osd_op_t *subop)
+{
+    // Include local blockstore ops in statistics
+    uint64_t opcode = bs_op_to_osd_op[subop->bs_op->opcode];
+    timespec tv_end;
+    clock_gettime(CLOCK_REALTIME, &tv_end);
+    c_cli.stats.op_stat_count[opcode]++;
+    if (!c_cli.stats.op_stat_count[opcode])
+    {
+        c_cli.stats.op_stat_count[opcode] = 1;
+        c_cli.stats.op_stat_sum[opcode] = 0;
+        c_cli.stats.op_stat_bytes[opcode] = 0;
+    }
+    c_cli.stats.op_stat_sum[opcode] += (
+        (tv_end.tv_sec - subop->tv_begin.tv_sec)*1000000 +
+        (tv_end.tv_nsec - subop->tv_begin.tv_nsec)/1000
+    );
+    if (opcode == OSD_OP_SEC_READ || opcode == OSD_OP_SEC_WRITE)
+    {
+        c_cli.stats.op_stat_bytes[opcode] += subop->bs_op->len;
+    }
+}
+
+void osd_t::handle_primary_subop(osd_op_t *subop, osd_op_t *cur_op)
+{
+    uint64_t opcode = subop->req.hdr.opcode;
+    int retval = subop->reply.hdr.retval;
+    int expected = opcode == OSD_OP_SEC_READ || opcode == OSD_OP_SEC_WRITE
+        || opcode == OSD_OP_SEC_WRITE_STABLE ? subop->req.sec_rw.len : 0;
+    osd_primary_op_data_t *op_data = cur_op->op_data;
+    if (retval != expected)
+    {
+        printf("%s subop failed: retval = %d (expected %d)\n", osd_op_names[opcode], retval, expected);
+        if (retval == -EPIPE)
+        {
+            op_data->epipe++;
+        }
+        op_data->errors++;
+    }
+    else
+    {
+        op_data->done++;
+        if (opcode == OSD_OP_SEC_READ || opcode == OSD_OP_SEC_WRITE || opcode == OSD_OP_SEC_WRITE_STABLE)
+        {
+            uint64_t version = subop->reply.sec_rw.version;
+#ifdef OSD_DEBUG
+            uint64_t peer_osd = c_cli.clients.find(subop->peer_fd) != c_cli.clients.end()
+                ? c_cli.clients[subop->peer_fd].osd_num : osd_num;
+            printf("subop %lu from osd %lu: version = %lu\n", opcode, peer_osd, version);
+#endif
+            if (op_data->fact_ver != 0 && op_data->fact_ver != version)
+            {
+                throw std::runtime_error(
+                    "different fact_versions returned from "+std::string(osd_op_names[opcode])+
+                    " subops: "+std::to_string(version)+" vs "+std::to_string(op_data->fact_ver)
+                );
+            }
+            op_data->fact_ver = version;
+        }
+    }
+    if ((op_data->errors + op_data->done) >= op_data->n_subops)
+    {
+        delete[] op_data->subops;
+        op_data->subops = NULL;
+        op_data->st++;
+        if (cur_op->req.hdr.opcode == OSD_OP_READ)
+        {
+            continue_primary_read(cur_op);
+        }
+        else if (cur_op->req.hdr.opcode == OSD_OP_WRITE)
+        {
+            continue_primary_write(cur_op);
+        }
+        else if (cur_op->req.hdr.opcode == OSD_OP_SYNC)
+        {
+            continue_primary_sync(cur_op);
+        }
+        else if (cur_op->req.hdr.opcode == OSD_OP_DELETE)
+        {
+            continue_primary_del(cur_op);
+        }
+        else
+        {
+            throw std::runtime_error("BUG: unknown opcode");
+        }
+    }
+}
+
+void osd_t::cancel_primary_write(osd_op_t *cur_op)
+{
+    if (cur_op->op_data && cur_op->op_data->subops)
+    {
+        // Primary-write operation is waiting for subops, subops
+        // are sent to peer OSDs, so we can't just throw them away.
+        // Mark them with an extra EPIPE.
+        cur_op->op_data->errors++;
+        cur_op->op_data->epipe++;
+        cur_op->op_data->done--; // Caution: `done` must be signed because may become -1 here
+    }
+    else
+    {
+        finish_op(cur_op, -EPIPE);
+    }
+}
+
+static bool contains_osd(osd_num_t *osd_set, uint64_t size, osd_num_t osd_num)
+{
+    for (uint64_t i = 0; i < size; i++)
+    {
+        if (osd_set[i] == osd_num)
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+void osd_t::submit_primary_del_subops(osd_op_t *cur_op, osd_num_t *cur_set, uint64_t set_size, pg_osd_set_t & loc_set)
+{
+    osd_primary_op_data_t *op_data = cur_op->op_data;
+    bool rep = op_data->scheme == POOL_SCHEME_REPLICATED;
+    int extra_chunks = 0;
+    // ordered comparison for EC/XOR, unordered for replicated pools
+    for (auto & chunk: loc_set)
+    {
+        if (!cur_set || (rep ? !contains_osd(cur_set, set_size, chunk.osd_num) : chunk.osd_num != cur_set[chunk.role]))
+        {
+            extra_chunks++;
+        }
+    }
+    op_data->n_subops = extra_chunks;
+    op_data->done = op_data->errors = 0;
+    if (!extra_chunks)
+    {
+        return;
+    }
+    osd_op_t *subops = new osd_op_t[extra_chunks];
+    op_data->subops = subops;
+    int i = 0;
+    for (auto & chunk: loc_set)
+    {
+        if (!cur_set || (rep ? !contains_osd(cur_set, set_size, chunk.osd_num) : chunk.osd_num != cur_set[chunk.role]))
+        {
+            int stripe_num = op_data->scheme == POOL_SCHEME_REPLICATED ? 0 : chunk.role;
+            if (chunk.osd_num == this->osd_num)
+            {
+                clock_gettime(CLOCK_REALTIME, &subops[i].tv_begin);
+                subops[i].op_type = (uint64_t)cur_op;
+                subops[i].bs_op = new blockstore_op_t({
+                    .opcode = BS_OP_DELETE,
+                    .callback = [subop = &subops[i], this](blockstore_op_t *bs_subop)
+                    {
+                        handle_primary_bs_subop(subop);
+                    },
+                    .oid = {
+                        .inode = op_data->oid.inode,
+                        .stripe = op_data->oid.stripe | stripe_num,
+                    },
+                    // Same version as write
+                    .version = op_data->fact_ver,
+                });
+                bs->enqueue_op(subops[i].bs_op);
+            }
+            else
+            {
+                subops[i].op_type = OSD_OP_OUT;
+                subops[i].peer_fd = c_cli.osd_peer_fds.at(chunk.osd_num);
+                subops[i].req.sec_del = {
+                    .header = {
+                        .magic = SECONDARY_OSD_OP_MAGIC,
+                        .id = c_cli.next_subop_id++,
+                        .opcode = OSD_OP_SEC_DELETE,
+                    },
+                    .oid = {
+                        .inode = op_data->oid.inode,
+                        .stripe = op_data->oid.stripe | stripe_num,
+                    },
+                    // Same version as write
+                    .version = op_data->fact_ver,
+                };
+                subops[i].callback = [cur_op, this](osd_op_t *subop)
+                {
+                    int fail_fd = subop->reply.hdr.retval != 0 ? subop->peer_fd : -1;
+                    handle_primary_subop(subop, cur_op);
+                    if (fail_fd >= 0)
+                    {
+                        // delete operation failed, drop the connection
+                        c_cli.stop_client(fail_fd);
+                    }
+                };
+                c_cli.outbox_push(&subops[i]);
+            }
+            i++;
+        }
+    }
+}
+
+void osd_t::submit_primary_sync_subops(osd_op_t *cur_op)
+{
+    osd_primary_op_data_t *op_data = cur_op->op_data;
+    int n_osds = op_data->dirty_osd_count;
+    osd_op_t *subops = new osd_op_t[n_osds];
+    op_data->done = op_data->errors = 0;
+    op_data->n_subops = n_osds;
+    op_data->subops = subops;
+    for (int i = 0; i < n_osds; i++)
+    {
+        osd_num_t sync_osd = op_data->dirty_osds[i];
+        if (sync_osd == this->osd_num)
+        {
+            clock_gettime(CLOCK_REALTIME, &subops[i].tv_begin);
+            subops[i].op_type = (uint64_t)cur_op;
+            subops[i].bs_op = new blockstore_op_t({
+                .opcode = BS_OP_SYNC,
+                .callback = [subop = &subops[i], this](blockstore_op_t *bs_subop)
+                {
+                    handle_primary_bs_subop(subop);
+                },
+            });
+            bs->enqueue_op(subops[i].bs_op);
+        }
+        else
+        {
+            subops[i].op_type = OSD_OP_OUT;
+            subops[i].peer_fd = c_cli.osd_peer_fds.at(sync_osd);
+            subops[i].req.sec_sync = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = c_cli.next_subop_id++,
+                    .opcode = OSD_OP_SEC_SYNC,
+                },
+            };
+            subops[i].callback = [cur_op, this](osd_op_t *subop)
+            {
+                int fail_fd = subop->reply.hdr.retval != 0 ? subop->peer_fd : -1;
+                handle_primary_subop(subop, cur_op);
+                if (fail_fd >= 0)
+                {
+                    // sync operation failed, drop the connection
+                    c_cli.stop_client(fail_fd);
+                }
+            };
+            c_cli.outbox_push(&subops[i]);
+        }
+    }
+}
+
+void osd_t::submit_primary_stab_subops(osd_op_t *cur_op)
+{
+    osd_primary_op_data_t *op_data = cur_op->op_data;
+    int n_osds = op_data->unstable_write_osds->size();
+    osd_op_t *subops = new osd_op_t[n_osds];
+    op_data->done = op_data->errors = 0;
+    op_data->n_subops = n_osds;
+    op_data->subops = subops;
+    for (int i = 0; i < n_osds; i++)
+    {
+        auto & stab_osd = (*(op_data->unstable_write_osds))[i];
+        if (stab_osd.osd_num == this->osd_num)
+        {
+            clock_gettime(CLOCK_REALTIME, &subops[i].tv_begin);
+            subops[i].op_type = (uint64_t)cur_op;
+            subops[i].bs_op = new blockstore_op_t({
+                .opcode = BS_OP_STABLE,
+                .callback = [subop = &subops[i], this](blockstore_op_t *bs_subop)
+                {
+                    handle_primary_bs_subop(subop);
+                },
+                .len = (uint32_t)stab_osd.len,
+                .buf = (void*)(op_data->unstable_writes + stab_osd.start),
+            });
+            bs->enqueue_op(subops[i].bs_op);
+        }
+        else
+        {
+            subops[i].op_type = OSD_OP_OUT;
+            subops[i].peer_fd = c_cli.osd_peer_fds.at(stab_osd.osd_num);
+            subops[i].req.sec_stab = {
+                .header = {
+                    .magic = SECONDARY_OSD_OP_MAGIC,
+                    .id = c_cli.next_subop_id++,
+                    .opcode = OSD_OP_SEC_STABILIZE,
+                },
+                .len = (uint64_t)(stab_osd.len * sizeof(obj_ver_id)),
+            };
+            subops[i].iov.push_back(op_data->unstable_writes + stab_osd.start, stab_osd.len * sizeof(obj_ver_id));
+            subops[i].callback = [cur_op, this](osd_op_t *subop)
+            {
+                int fail_fd = subop->reply.hdr.retval != 0 ? subop->peer_fd : -1;
+                handle_primary_subop(subop, cur_op);
+                if (fail_fd >= 0)
+                {
+                    // sync operation failed, drop the connection
+                    c_cli.stop_client(fail_fd);
+                }
+            };
+            c_cli.outbox_push(&subops[i]);
+        }
+    }
+}
+
+void osd_t::pg_cancel_write_queue(pg_t & pg, osd_op_t *first_op, object_id oid, int retval)
+{
+    auto st_it = pg.write_queue.find(oid), it = st_it;
+    finish_op(first_op, retval);
+    if (it != pg.write_queue.end() && it->second == first_op)
+    {
+        it++;
+    }
+    else
+    {
+        // Write queue doesn't match the first operation.
+        // first_op is a leftover operation from the previous peering of the same PG.
+        return;
+    }
+    while (it != pg.write_queue.end() && it->first == oid)
+    {
+        finish_op(it->second, retval);
+        it++;
+    }
+    if (st_it != it)
+    {
+        pg.write_queue.erase(st_it, it);
+    }
+}

osd_receive.cpp

@@ -1,206 +0,0 @@
-#include "osd.h"
-
-void osd_t::read_requests()
-{
-    for (int i = 0; i < read_ready_clients.size(); i++)
-    {
-        int peer_fd = read_ready_clients[i];
-        auto & cl = clients[peer_fd];
-        io_uring_sqe* sqe = ringloop->get_sqe();
-        if (!sqe)
-        {
-            read_ready_clients.erase(read_ready_clients.begin(), read_ready_clients.begin() + i);
-            return;
-        }
-        ring_data_t* data = ((ring_data_t*)sqe->user_data);
-        if (!cl.read_buf)
-        {
-            // no reads in progress
-            // so this is either a new command or a reply to a previously sent command
-            if (!cl.read_op)
-            {
-                cl.read_op = new osd_op_t;
-                cl.read_op->peer_fd = peer_fd;
-            }
-            cl.read_op->op_type = OSD_OP_IN;
-            cl.read_buf = &cl.read_op->req.buf;
-            cl.read_remaining = OSD_PACKET_SIZE;
-            cl.read_state = CL_READ_OP;
-        }
-        cl.read_iov.iov_base = cl.read_buf;
-        cl.read_iov.iov_len = cl.read_remaining;
-        cl.read_msg.msg_iov = &cl.read_iov;
-        cl.read_msg.msg_iovlen = 1;
-        data->callback = [this, peer_fd](ring_data_t *data) { handle_read(data, peer_fd); };
-        my_uring_prep_recvmsg(sqe, cl.peer_fd_index, &cl.read_msg, 0);
-        sqe->flags |= IOSQE_FIXED_FILE;
-    }
-    read_ready_clients.clear();
-}
-
-void osd_t::handle_read(ring_data_t *data, int peer_fd)
-{
-    int res = data->res;
-    auto cl_it = clients.find(peer_fd);
-    if (cl_it != clients.end())
-    {
-        auto & cl = cl_it->second;
-        if (res == -EAGAIN)
-        {
-            cl.read_ready--;
-            if (cl.read_ready > 0)
-                read_ready_clients.push_back(peer_fd);
-            return;
-        }
-        else if (res < 0)
-        {
-            // this is a client socket, so don't panic. just disconnect it
-            printf("Client %d socket read error: %d (%s). Disconnecting client\n", peer_fd, -res, strerror(-res));
-            stop_client(peer_fd);
-            return;
-        }
-        read_ready_clients.push_back(peer_fd);
-        if (res > 0)
-        {
-            cl.read_remaining -= res;
-            cl.read_buf += res;
-            if (cl.read_remaining <= 0)
-            {
-                cl.read_buf = NULL;
-                if (cl.read_state == CL_READ_OP)
-                {
-                    if (cl.read_op->req.hdr.magic == SECONDARY_OSD_REPLY_MAGIC)
-                    {
-                        handle_reply_hdr(&cl);
-                    }
-                    else
-                    {
-                        handle_op_hdr(&cl);
-                    }
-                }
-                else if (cl.read_state == CL_READ_DATA)
-                {
-                    // Operation is ready
-                    exec_op(cl.read_op);
-                    cl.read_op = NULL;
-                    cl.read_state = 0;
-                }
-                else if (cl.read_state == CL_READ_REPLY_DATA)
-                {
-                    // Reply is ready
-                    auto req_it = cl.sent_ops.find(cl.read_reply_id);
-                    osd_op_t *request = req_it->second;
-                    cl.sent_ops.erase(req_it);
-                    cl.read_reply_id = 0;
-                    cl.read_state = 0;
-                    // Measure subop latency
-                    timespec tv_end;
-                    clock_gettime(CLOCK_REALTIME, &tv_end);
-                    subop_stat_count[request->req.hdr.opcode]++;
-                    subop_stat_sum[request->req.hdr.opcode] += (
-                        (tv_end.tv_sec - request->tv_begin.tv_sec)*1000000 +
-                        (tv_end.tv_nsec - request->tv_begin.tv_nsec)/1000
-                    );
-                    request->callback(request);
-                }
-            }
-        }
-    }
-}
-
-void osd_t::handle_op_hdr(osd_client_t *cl)
-{
-    osd_op_t *cur_op = cl->read_op;
-    if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_READ)
-    {
-        if (cur_op->req.sec_rw.len > 0)
-            cur_op->buf = memalign(512, cur_op->req.sec_rw.len);
-        cl->read_remaining = 0;
-    }
-    else if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_WRITE)
-    {
-        if (cur_op->req.sec_rw.len > 0)
-            cur_op->buf = memalign(512, cur_op->req.sec_rw.len);
-        cl->read_remaining = cur_op->req.sec_rw.len;
-    }
-    else if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_STABILIZE ||
-        cur_op->req.hdr.opcode == OSD_OP_SECONDARY_ROLLBACK)
-    {
-        if (cur_op->req.sec_stab.len > 0)
-            cur_op->buf = memalign(512, cur_op->req.sec_stab.len);
-        cl->read_remaining = cur_op->req.sec_stab.len;
-    }
-    else if (cur_op->req.hdr.opcode == OSD_OP_READ)
-    {
-        if (cur_op->req.rw.len > 0)
-            cur_op->buf = memalign(512, cur_op->req.rw.len);
-        cl->read_remaining = 0;
-    }
-    else if (cur_op->req.hdr.opcode == OSD_OP_WRITE)
-    {
-        if (cur_op->req.rw.len > 0)
-            cur_op->buf = memalign(512, cur_op->req.rw.len);
-        cl->read_remaining = cur_op->req.rw.len;
-    }
-    if (cl->read_remaining > 0)
-    {
-        // Read data
-        cl->read_buf = cur_op->buf;
-        cl->read_state = CL_READ_DATA;
-    }
-    else
-    {
-        // Operation is ready
-        cl->read_op = NULL;
-        cl->read_state = 0;
-        exec_op(cur_op);
-    }
-}
-
-void osd_t::handle_reply_hdr(osd_client_t *cl)
-{
-    osd_op_t *cur_op = cl->read_op;
-    auto req_it = cl->sent_ops.find(cur_op->req.hdr.id);
-    if (req_it == cl->sent_ops.end())
-    {
-        // Command out of sync. Drop connection
-        printf("Client %d command out of sync: id %lu\n", cl->peer_fd, cur_op->req.hdr.id);
-        stop_client(cl->peer_fd);
-        return;
-    }
-    osd_op_t *op = req_it->second;
-    memcpy(op->reply.buf, cur_op->req.buf, OSD_PACKET_SIZE);
-    if (op->reply.hdr.opcode == OSD_OP_SECONDARY_READ &&
-        op->reply.hdr.retval > 0)
-    {
-        // Read data. In this case we assume that the buffer is preallocated by the caller (!)
-        assert(op->buf);
-        cl->read_state = CL_READ_REPLY_DATA;
-        cl->read_reply_id = op->req.hdr.id;
-        cl->read_buf = op->buf;
-        cl->read_remaining = op->reply.hdr.retval;
-    }
-    else if (op->reply.hdr.opcode == OSD_OP_SECONDARY_LIST &&
-        op->reply.hdr.retval > 0)
-    {
-        op->buf = memalign(512, sizeof(obj_ver_id) * op->reply.hdr.retval);
-        cl->read_state = CL_READ_REPLY_DATA;
-        cl->read_reply_id = op->req.hdr.id;
-        cl->read_buf = op->buf;
-        cl->read_remaining = sizeof(obj_ver_id) * op->reply.hdr.retval;
-    }
-    else
-    {
-        cl->read_state = 0;
-        cl->sent_ops.erase(req_it);
-        // Measure subop latency
-        timespec tv_end;
-        clock_gettime(CLOCK_REALTIME, &tv_end);
-        subop_stat_count[op->req.hdr.opcode]++;
-        subop_stat_sum[op->req.hdr.opcode] += (
-            (tv_end.tv_sec - op->tv_begin.tv_sec)*1000000 +
-            (tv_end.tv_nsec - op->tv_begin.tv_nsec)/1000
-        );
-        op->callback(op);
-    }
-}

osd_rmw.cpp

@@ -1,7 +1,11 @@
-#include <malloc.h>
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
+#include <string.h>
 #include <assert.h>
 #include "xor.h"
 #include "osd_rmw.h"
+#include "malloc_or_die.h"
 
 static inline void extend_read(uint32_t start, uint32_t end, osd_rmw_stripe_t & stripe)
 {
@@ -55,6 +59,11 @@ static inline void cover_read(uint32_t start, uint32_t end, osd_rmw_stripe_t & s
 
 void split_stripes(uint64_t pg_minsize, uint32_t bs_block_size, uint32_t start, uint32_t end, osd_rmw_stripe_t *stripes)
 {
+    if (end == 0)
+    {
+        // Zero length request - offset doesn't matter
+        return;
+    }
     end = start+end;
     for (int role = 0; role < pg_minsize; role++)
     {
@@ -66,7 +75,7 @@ void split_stripes(uint64_t pg_minsize, uint32_t bs_block_size, uint32_t start,
     }
 }
 
-void reconstruct_stripe(osd_rmw_stripe_t *stripes, int pg_size, int role)
+void reconstruct_stripe_xor(osd_rmw_stripe_t *stripes, int pg_size, int role)
 {
     int prev = -2;
     for (int other = 0; other < pg_size; other++)
@@ -79,18 +88,21 @@ void reconstruct_stripe(osd_rmw_stripe_t *stripes, int pg_size, int role)
             }
             else if (prev >= 0)
             {
+                assert(stripes[role].read_start >= stripes[prev].read_start &&
+                    stripes[role].read_start >= stripes[other].read_start);
                 memxor(
-                    stripes[prev].read_buf + (stripes[prev].read_start - stripes[role].read_start),
-                    stripes[other].read_buf + (stripes[other].read_start - stripes[other].read_start),
+                    stripes[prev].read_buf + (stripes[role].read_start - stripes[prev].read_start),
+                    stripes[other].read_buf + (stripes[role].read_start - stripes[other].read_start),
                     stripes[role].read_buf, stripes[role].read_end - stripes[role].read_start
                 );
                 prev = -1;
             }
             else
             {
+                assert(stripes[role].read_start >= stripes[other].read_start);
                 memxor(
                     stripes[role].read_buf,
-                    stripes[other].read_buf + (stripes[other].read_start - stripes[role].read_start),
+                    stripes[other].read_buf + (stripes[role].read_start - stripes[other].read_start),
                     stripes[role].read_buf, stripes[role].read_end - stripes[role].read_start
                 );
             }
@@ -143,7 +155,7 @@ void* alloc_read_buffer(osd_rmw_stripe_t *stripes, int read_pg_size, uint64_t ad
         }
     }
     // Allocate buffer
-    void *buf = memalign(MEM_ALIGNMENT, buf_size);
+    void *buf = memalign_or_die(MEM_ALIGNMENT, buf_size);
     uint64_t buf_pos = add_size;
     for (int role = 0; role < read_pg_size; role++)
     {
@@ -156,10 +168,11 @@ void* alloc_read_buffer(osd_rmw_stripe_t *stripes, int read_pg_size, uint64_t ad
     return buf;
 }
 
-void* calc_rmw_reads(void *write_buf, osd_rmw_stripe_t *stripes, uint64_t *osd_set, uint64_t pg_size, uint64_t pg_minsize, uint64_t pg_cursize)
+void* calc_rmw(void *request_buf, osd_rmw_stripe_t *stripes, uint64_t *read_osd_set,
+    uint64_t pg_size, uint64_t pg_minsize, uint64_t pg_cursize, uint64_t *write_osd_set, uint64_t chunk_size)
 {
     // Generic parity modification (read-modify-write) algorithm
-    // Reconstruct -> Read -> Calc parity -> Write
+    // Read -> Reconstruct missing chunks -> Calc parity chunks -> Write
     // Now we always read continuous ranges. This means that an update of the beginning
     // of one data stripe and the end of another will lead to a read of full paired stripes.
     // FIXME: (Maybe) read small individual ranges in that case instead.
@@ -174,64 +187,89 @@ void* calc_rmw_reads(void *write_buf, osd_rmw_stripe_t *stripes, uint64_t *osd_s
             stripes[role].write_end = stripes[role].req_end;
         }
     }
-    for (int role = 0; role < pg_minsize; role++)
-    {
-        cover_read(start, end, stripes[role]);
-    }
-    int has_parity = 0;
+    int write_parity = 0;
     for (int role = pg_minsize; role < pg_size; role++)
     {
-        if (osd_set[role] != 0)
+        if (write_osd_set[role] != 0)
         {
-            has_parity++;
+            write_parity = 1;
             stripes[role].write_start = start;
             stripes[role].write_end = end;
         }
-        else
-            stripes[role].missing = true;
+    }
+    if (write_parity)
+    {
+        for (int role = 0; role < pg_minsize; role++)
+        {
+            cover_read(start, end, stripes[role]);
+        }
+    }
+    if (write_osd_set != read_osd_set)
+    {
+        pg_cursize = 0;
+        // Object is degraded/misplaced and will be moved to <write_osd_set>
+        for (int role = 0; role < pg_size; role++)
+        {
+            if (write_osd_set[role] != read_osd_set[role] && write_osd_set[role] != 0)
+            {
+                // We need to get data for any moved / recovered chunk
+                // And we need a continuous write buffer so we'll only optimize
+                // for the case when the whole chunk is ovewritten in the request
+                if (stripes[role].req_start != 0 ||
+                    stripes[role].req_end != chunk_size)
+                {
+                    stripes[role].read_start = 0;
+                    stripes[role].read_end = chunk_size;
+                    // Warning: We don't modify write_start/write_end here, we do it in calc_rmw_parity()
+                }
+            }
+            if (read_osd_set[role] != 0)
+            {
+                pg_cursize++;
+            }
+        }
     }
     if (pg_cursize < pg_size)
     {
-        if (has_parity == 0)
+        // Some stripe(s) are missing, so we need to read parity
+        for (int role = 0; role < pg_size; role++)
         {
-            // Parity is missing, we don't need to read anything
-            for (int role = 0; role < pg_minsize; role++)
+            if (read_osd_set[role] == 0)
             {
-                stripes[role].read_end = 0;
-            }
-        }
-        else
-        {
-            // Other stripe(s) are missing
-            for (int role = 0; role < pg_minsize; role++)
-            {
-                if (osd_set[role] == 0 && stripes[role].read_end != 0)
+                stripes[role].missing = true;
+                if (stripes[role].read_end != 0)
                 {
-                    stripes[role].missing = true;
-                    for (int r2 = 0; r2 < pg_size; r2++)
+                    int found = 0;
+                    for (int r2 = 0; r2 < pg_size && found < pg_minsize; r2++)
                     {
-                        // Read the non-covered range of <role> from all other stripes to reconstruct it
-                        if (r2 != role && osd_set[r2] != 0)
+                        // Read the non-covered range of <role> from at least <minsize> other stripes to reconstruct it
+                        if (read_osd_set[r2] != 0)
                         {
                             extend_read(stripes[role].read_start, stripes[role].read_end, stripes[r2]);
+                            found++;
                         }
                     }
+                    if (found < pg_minsize)
+                    {
+                        // FIXME Object is incomplete - refuse partial overwrite
+                        assert(0);
+                    }
                 }
             }
         }
     }
     // Allocate read buffers
-    void *rmw_buf = alloc_read_buffer(stripes, pg_size, has_parity * (end - start));
-    // Position parity & write buffers
+    void *rmw_buf = alloc_read_buffer(stripes, pg_size, (write_parity ? pg_size-pg_minsize : 0) * (end - start));
+    // Position write buffers
     uint64_t buf_pos = 0, in_pos = 0;
     for (int role = 0; role < pg_size; role++)
     {
         if (stripes[role].req_end != 0)
         {
-            stripes[role].write_buf = write_buf + in_pos;
+            stripes[role].write_buf = request_buf + in_pos;
             in_pos += stripes[role].req_end - stripes[role].req_start;
         }
-        else if (role >= pg_minsize && osd_set[role] != 0)
+        else if (role >= pg_minsize && write_osd_set[role] != 0 && end != 0)
         {
             stripes[role].write_buf = rmw_buf + buf_pos;
             buf_pos += end - start;
@@ -321,47 +359,94 @@ static void xor_multiple_buffers(buf_len_t *xor1, int n1, buf_len_t *xor2, int n
     }
 }
 
-void calc_rmw_parity(osd_rmw_stripe_t *stripes, int pg_size)
+void calc_rmw_parity_xor(osd_rmw_stripe_t *stripes, int pg_size, uint64_t *read_osd_set, uint64_t *write_osd_set, uint32_t chunk_size)
 {
-    if (stripes[pg_size-1].missing)
-    {
-        // Parity OSD is unavailable
-        return;
-    }
+    int pg_minsize = pg_size-1;
     for (int role = 0; role < pg_size; role++)
     {
         if (stripes[role].read_end != 0 && stripes[role].missing)
         {
-            // Reconstruct missing stripe (EC k+1)
-            reconstruct_stripe(stripes, pg_size, role);
+            // Reconstruct missing stripe (XOR k+1)
+            reconstruct_stripe_xor(stripes, pg_size, role);
             break;
         }
     }
-    // Calculate new parity (EC k+1)
-    int parity = pg_size-1, prev = -2;
-    auto wr_end = stripes[parity].write_end;
-    auto wr_start = stripes[parity].write_start;
-    for (int other = 0; other < pg_size-1; other++)
+    uint32_t start = 0, end = 0;
+    if (write_osd_set[pg_minsize] != 0 || write_osd_set != read_osd_set)
     {
-        if (prev == -2)
+        // Required for the next two if()s
+        for (int role = 0; role < pg_minsize; role++)
         {
-            prev = other;
-        }
-        else
-        {
-            int n1 = 0, n2 = 0;
-            buf_len_t xor1[3], xor2[3];
-            if (prev == -1)
+            if (stripes[role].req_end != 0)
             {
-                xor1[n1++] = { .buf = stripes[parity].write_buf, .len = wr_end-wr_start };
+                start = !end || stripes[role].req_start < start ? stripes[role].req_start : start;
+                end = std::max(stripes[role].req_end, end);
+            }
+        }
+    }
+    if (write_osd_set != read_osd_set)
+    {
+        for (int role = 0; role < pg_minsize; role++)
+        {
+            if (write_osd_set[role] != read_osd_set[role] && write_osd_set[role] != 0 &&
+                (stripes[role].req_start != 0 || stripes[role].req_end != chunk_size))
+            {
+                // Copy modified chunk into the read buffer to write it back
+                memcpy(
+                    stripes[role].read_buf + stripes[role].req_start,
+                    stripes[role].write_buf,
+                    stripes[role].req_end - stripes[role].req_start
+                );
+                stripes[role].write_buf = stripes[role].read_buf;
+                stripes[role].write_start = 0;
+                stripes[role].write_end = chunk_size;
+            }
+        }
+    }
+    if (write_osd_set[pg_minsize] != 0 && end != 0)
+    {
+        // Calculate new parity (XOR k+1)
+        int parity = pg_minsize, prev = -2;
+        for (int other = 0; other < pg_minsize; other++)
+        {
+            if (prev == -2)
+            {
+                prev = other;
             }
             else
             {
-                get_old_new_buffers(stripes[prev], wr_start, wr_end, xor1, n1);
-                prev = -1;
+                int n1 = 0, n2 = 0;
+                buf_len_t xor1[3], xor2[3];
+                if (prev == -1)
+                {
+                    xor1[n1++] = { .buf = stripes[parity].write_buf, .len = end-start };
+                }
+                else
+                {
+                    get_old_new_buffers(stripes[prev], start, end, xor1, n1);
+                    prev = -1;
+                }
+                get_old_new_buffers(stripes[other], start, end, xor2, n2);
+                xor_multiple_buffers(xor1, n1, xor2, n2, stripes[parity].write_buf, end-start);
+            }
+        }
+    }
+    if (write_osd_set != read_osd_set)
+    {
+        for (int role = pg_minsize; role < pg_size; role++)
+        {
+            if (write_osd_set[role] != read_osd_set[role] && (start != 0 || end != chunk_size))
+            {
+                // Copy new parity into the read buffer to write it back
+                memcpy(
+                    stripes[role].read_buf + start,
+                    stripes[role].write_buf,
+                    end - start
+                );
+                stripes[role].write_buf = stripes[role].read_buf;
+                stripes[role].write_start = 0;
+                stripes[role].write_end = chunk_size;
             }
-            get_old_new_buffers(stripes[other], wr_start, wr_end, xor2, n2);
-            xor_multiple_buffers(xor1, n1, xor2, n2, stripes[parity].write_buf, wr_end-wr_start);
         }
     }
 }

osd_rmw.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include <stdint.h>
@@ -25,12 +28,13 @@ struct osd_rmw_stripe_t
 
 void split_stripes(uint64_t pg_minsize, uint32_t bs_block_size, uint32_t start, uint32_t len, osd_rmw_stripe_t *stripes);
 
-void reconstruct_stripe(osd_rmw_stripe_t *stripes, int pg_size, int role);
+void reconstruct_stripe_xor(osd_rmw_stripe_t *stripes, int pg_size, int role);
 
 int extend_missing_stripes(osd_rmw_stripe_t *stripes, osd_num_t *osd_set, int minsize, int size);
 
 void* alloc_read_buffer(osd_rmw_stripe_t *stripes, int read_pg_size, uint64_t add_size);
 
-void* calc_rmw_reads(void *write_buf, osd_rmw_stripe_t *stripes, uint64_t *osd_set, uint64_t pg_size, uint64_t pg_minsize, uint64_t pg_cursize);
+void* calc_rmw(void *request_buf, osd_rmw_stripe_t *stripes, uint64_t *read_osd_set,
+    uint64_t pg_size, uint64_t pg_minsize, uint64_t pg_cursize, uint64_t *write_osd_set, uint64_t chunk_size);
 
-void calc_rmw_parity(osd_rmw_stripe_t *stripes, int pg_size);
+void calc_rmw_parity_xor(osd_rmw_stripe_t *stripes, int pg_size, uint64_t *read_osd_set, uint64_t *write_osd_set, uint32_t chunk_size);

osd_rmw_test.cpp

@@ -1,17 +1,151 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <string.h>
 #include "osd_rmw.cpp"
 #include "test_pattern.h"
 
+void dump_stripes(osd_rmw_stripe_t *stripes, int pg_size);
+void test1();
+void test4();
+void test5();
+void test6();
+void test7();
+void test8();
+void test9();
+
+/***
+
+Cases:
+
+1. split(offset=128K-4K, len=8K)
+   = [ [ 128K-4K, 128K ], [ 0, 4K ], [ 0, 0 ] ]
+
+2. read(offset=128K-4K, len=8K, osd_set=[1,0,3])
+   = { read: [ [ 0, 128K ], [ 0, 4K ], [ 0, 4K ] ] }
+
+3. cover_read(0, 128K, { req: [ 128K-4K, 4K ] })
+   = { read: [ 0, 128K-4K ] }
+
+4. write(offset=128K-4K, len=8K, osd_set=[1,0,3])
+   = {
+     read: [ [ 0, 128K ], [ 4K, 128K ], [ 4K, 128K ] ],
+     write: [ [ 128K-4K, 128K ], [ 0, 4K ], [ 0, 128K ] ],
+     input buffer: [ write0, write1 ],
+     rmw buffer: [ write2, read0, read1, read2 ],
+   }
+   + check write2 buffer
+
+5. write(offset=0, len=128K+64K, osd_set=[1,0,3])
+   = {
+     req: [ [ 0, 128K ], [ 0, 64K ], [ 0, 0 ] ],
+     read: [ [ 64K, 128K ], [ 64K, 128K ], [ 64K, 128K ] ],
+     write: [ [ 0, 128K ], [ 0, 64K ], [ 0, 128K ] ],
+     input buffer: [ write0, write1 ],
+     rmw buffer: [ write2, read0, read1, read2 ],
+   }
+
+6. write(offset=0, len=128K+64K, osd_set=[1,2,3])
+   = {
+     req: [ [ 0, 128K ], [ 0, 64K ], [ 0, 0 ] ],
+     read: [ [ 0, 0 ], [ 64K, 128K ], [ 0, 0 ] ],
+     write: [ [ 0, 128K ], [ 0, 64K ], [ 0, 128K ] ],
+     input buffer: [ write0, write1 ],
+     rmw buffer: [ write2, read1 ],
+   }
+
+7. calc_rmw(offset=128K-4K, len=8K, osd_set=[1,0,3], write_set=[1,2,3])
+   = {
+     read: [ [ 0, 128K ], [ 0, 128K ], [ 0, 128K ] ],
+     write: [ [ 128K-4K, 128K ], [ 0, 4K ], [ 0, 128K ] ],
+     input buffer: [ write0, write1 ],
+     rmw buffer: [ write2, read0, read1, read2 ],
+   }
+   then, after calc_rmw_parity_xor(): {
+     write: [ [ 128K-4K, 128K ], [ 0, 128K ], [ 0, 128K ] ],
+     write1==read1,
+   }
+   + check write1 buffer
+   + check write2 buffer
+
+8. calc_rmw(offset=0, len=128K+4K, osd_set=[0,2,3], write_set=[1,2,3])
+   = {
+     read: [ [ 0, 0 ], [ 4K, 128K ], [ 0, 0 ] ],
+     write: [ [ 0, 128K ], [ 0, 4K ], [ 0, 128K ] ],
+     input buffer: [ write0, write1 ],
+     rmw buffer: [ write2, read1 ],
+   }
+   + check write2 buffer
+
+9. object recovery case:
+   calc_rmw(offset=0, len=0, read_osd_set=[0,2,3], write_osd_set=[1,2,3])
+   = {
+     read: [ [ 0, 128K ], [ 0, 128K ], [ 0, 128K ] ],
+     write: [ [ 0, 0 ], [ 0, 0 ], [ 0, 0 ] ],
+     input buffer: NULL,
+     rmw buffer: [ read0, read1, read2 ],
+   }
+   then, after calc_rmw_parity_xor(): {
+     write: [ [ 0, 128K ], [ 0, 0 ], [ 0, 0 ] ],
+     write0==read0,
+   }
+   + check write0 buffer
+
+***/
+
 int main(int narg, char *args[])
+{
+    // Test 1
+    test1();
+    // Test 4
+    test4();
+    // Test 5
+    test5();
+    // Test 6
+    test6();
+    // Test 7
+    test7();
+    // Test 8
+    test8();
+    // Test 9
+    test9();
+    // End
+    printf("all ok\n");
+    return 0;
+}
+
+void dump_stripes(osd_rmw_stripe_t *stripes, int pg_size)
+{
+    printf("request");
+    for (int i = 0; i < pg_size; i++)
+    {
+        printf(" {%uK-%uK}", stripes[i].req_start/1024, stripes[i].req_end/1024);
+    }
+    printf("\n");
+    printf("read");
+    for (int i = 0; i < pg_size; i++)
+    {
+        printf(" {%uK-%uK}", stripes[i].read_start/1024, stripes[i].read_end/1024);
+    }
+    printf("\n");
+    printf("write");
+    for (int i = 0; i < pg_size; i++)
+    {
+        printf(" {%uK-%uK}", stripes[i].write_start/1024, stripes[i].write_end/1024);
+    }
+    printf("\n");
+}
+
+void test1()
 {
     osd_num_t osd_set[3] = { 1, 0, 3 };
     osd_rmw_stripe_t stripes[3] = { 0 };
-    // Test 1
+    // Test 1.1
     split_stripes(2, 128*1024, 128*1024-4096, 8192, stripes);
     assert(stripes[0].req_start == 128*1024-4096 && stripes[0].req_end == 128*1024);
     assert(stripes[1].req_start == 0 && stripes[1].req_end == 4096);
     assert(stripes[2].req_end == 0);
-    // Test 2
+    // Test 1.2
     for (int i = 0; i < 3; i++)
     {
         stripes[i].read_start = stripes[i].req_start;
@@ -20,18 +154,26 @@ int main(int narg, char *args[])
     assert(extend_missing_stripes(stripes, osd_set, 2, 3) == 0);
     assert(stripes[0].read_start == 0 && stripes[0].read_end == 128*1024);
     assert(stripes[2].read_start == 0 && stripes[2].read_end == 4096);
-    // Test 3
+    // Test 1.3
     stripes[0] = { .req_start = 128*1024-4096, .req_end = 128*1024 };
     cover_read(0, 128*1024, stripes[0]);
     assert(stripes[0].read_start == 0 && stripes[0].read_end == 128*1024-4096);
+}
+
+void test4()
+{
+    osd_num_t osd_set[3] = { 1, 0, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
     // Test 4.1
-    memset(stripes, 0, sizeof(stripes));
     split_stripes(2, 128*1024, 128*1024-4096, 8192, stripes);
     void* write_buf = malloc(8192);
-    void* rmw_buf = calc_rmw_reads(write_buf, stripes, osd_set, 3, 2, 2);
+    void* rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 2, osd_set, 128*1024);
     assert(stripes[0].read_start == 0 && stripes[0].read_end == 128*1024);
     assert(stripes[1].read_start == 4096 && stripes[1].read_end == 128*1024);
     assert(stripes[2].read_start == 4096 && stripes[2].read_end == 128*1024);
+    assert(stripes[0].write_start == 128*1024-4096 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 4096);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
     assert(stripes[0].read_buf == rmw_buf+128*1024);
     assert(stripes[1].read_buf == rmw_buf+128*1024*2);
     assert(stripes[2].read_buf == rmw_buf+128*1024*3-4096);
@@ -43,24 +185,32 @@ int main(int narg, char *args[])
     set_pattern(stripes[0].read_buf, 128*1024, PATTERN1); // old data
     set_pattern(stripes[1].read_buf, 128*1024-4096, UINT64_MAX); // didn't read it, it's missing
     set_pattern(stripes[2].read_buf, 128*1024-4096, 0); // old parity = 0
-    calc_rmw_parity(stripes, 3);
+    calc_rmw_parity_xor(stripes, 3, osd_set, osd_set, 128*1024);
     check_pattern(stripes[2].write_buf, 4096, PATTERN0^PATTERN1); // new parity
     check_pattern(stripes[2].write_buf+4096, 128*1024-4096*2, 0); // new parity
     check_pattern(stripes[2].write_buf+128*1024-4096, 4096, PATTERN0^PATTERN1); // new parity
     free(rmw_buf);
     free(write_buf);
+}
+
+void test5()
+{
+    osd_num_t osd_set[3] = { 1, 0, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
     // Test 5.1
-    memset(stripes, 0, sizeof(stripes));
     split_stripes(2, 128*1024, 0, 64*1024*3, stripes);
     assert(stripes[0].req_start == 0 && stripes[0].req_end == 128*1024);
     assert(stripes[1].req_start == 0 && stripes[1].req_end == 64*1024);
     assert(stripes[2].req_end == 0);
     // Test 5.2
-    write_buf = malloc(64*1024*3);
-    rmw_buf = calc_rmw_reads(write_buf, stripes, osd_set, 3, 2, 2);
+    void *write_buf = malloc(64*1024*3);
+    void *rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 2, osd_set, 128*1024);
     assert(stripes[0].read_start == 64*1024 && stripes[0].read_end == 128*1024);
     assert(stripes[1].read_start == 64*1024 && stripes[1].read_end == 128*1024);
     assert(stripes[2].read_start == 64*1024 && stripes[2].read_end == 128*1024);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 64*1024);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
     assert(stripes[0].read_buf == rmw_buf+128*1024);
     assert(stripes[1].read_buf == rmw_buf+64*3*1024);
     assert(stripes[2].read_buf == rmw_buf+64*4*1024);
@@ -69,15 +219,22 @@ int main(int narg, char *args[])
     assert(stripes[2].write_buf == rmw_buf);
     free(rmw_buf);
     free(write_buf);
+}
+
+void test6()
+{
+    osd_num_t osd_set[3] = { 1, 2, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
     // Test 6.1
-    memset(stripes, 0, sizeof(stripes));
     split_stripes(2, 128*1024, 0, 64*1024*3, stripes);
-    osd_set[1] = 2;
-    write_buf = malloc(64*1024*3);
-    rmw_buf = calc_rmw_reads(write_buf, stripes, osd_set, 3, 2, 3);
+    void *write_buf = malloc(64*1024*3);
+    void *rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 3, osd_set, 128*1024);
     assert(stripes[0].read_end == 0);
     assert(stripes[1].read_start == 64*1024 && stripes[1].read_end == 128*1024);
     assert(stripes[2].read_end == 0);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 64*1024);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
     assert(stripes[0].read_buf == 0);
     assert(stripes[1].read_buf == rmw_buf+128*1024);
     assert(stripes[2].read_buf == 0);
@@ -86,8 +243,121 @@ int main(int narg, char *args[])
     assert(stripes[2].write_buf == rmw_buf);
     free(rmw_buf);
     free(write_buf);
-    osd_set[1] = 0;
-    // End
-    printf("all ok\n");
-    return 0;
+}
+
+void test7()
+{
+    osd_num_t osd_set[3] = { 1, 0, 3 };
+    osd_num_t write_osd_set[3] = { 1, 2, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
+    // Test 7.1
+    split_stripes(2, 128*1024, 128*1024-4096, 8192, stripes);
+    void *write_buf = malloc(8192);
+    void *rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 2, write_osd_set, 128*1024);
+    assert(stripes[0].read_start == 0 && stripes[0].read_end == 128*1024);
+    assert(stripes[1].read_start == 0 && stripes[1].read_end == 128*1024);
+    assert(stripes[2].read_start == 0 && stripes[2].read_end == 128*1024);
+    assert(stripes[0].write_start == 128*1024-4096 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 4096);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
+    assert(stripes[0].read_buf == rmw_buf+128*1024);
+    assert(stripes[1].read_buf == rmw_buf+128*1024*2);
+    assert(stripes[2].read_buf == rmw_buf+128*1024*3);
+    assert(stripes[0].write_buf == write_buf);
+    assert(stripes[1].write_buf == write_buf+4096);
+    assert(stripes[2].write_buf == rmw_buf);
+    // Test 7.2
+    set_pattern(write_buf, 8192, PATTERN0);
+    set_pattern(stripes[0].read_buf, 128*1024, PATTERN1); // old data
+    set_pattern(stripes[1].read_buf, 128*1024, UINT64_MAX); // didn't read it, it's missing
+    set_pattern(stripes[2].read_buf, 128*1024, 0); // old parity = 0
+    calc_rmw_parity_xor(stripes, 3, osd_set, write_osd_set, 128*1024);
+    assert(stripes[0].write_start == 128*1024-4096 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 128*1024);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
+    assert(stripes[1].write_buf == stripes[1].read_buf);
+    check_pattern(stripes[1].write_buf, 4096, PATTERN0);
+    check_pattern(stripes[1].write_buf+4096, 128*1024-4096, PATTERN1);
+    check_pattern(stripes[2].write_buf, 4096, PATTERN0^PATTERN1); // new parity
+    check_pattern(stripes[2].write_buf+4096, 128*1024-4096*2, 0); // new parity
+    check_pattern(stripes[2].write_buf+128*1024-4096, 4096, PATTERN0^PATTERN1); // new parity
+    free(rmw_buf);
+    free(write_buf);
+}
+
+void test8()
+{
+    osd_num_t osd_set[3] = { 0, 2, 3 };
+    osd_num_t write_osd_set[3] = { 1, 2, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
+    // Test 8.1
+    split_stripes(2, 128*1024, 0, 128*1024+4096, stripes);
+    void *write_buf = malloc(128*1024+4096);
+    void *rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 2, write_osd_set, 128*1024);
+    assert(stripes[0].read_start == 0 && stripes[0].read_end == 0);
+    assert(stripes[1].read_start == 4096 && stripes[1].read_end == 128*1024);
+    assert(stripes[2].read_start == 0 && stripes[2].read_end == 0);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 4096);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024);
+    assert(stripes[0].read_buf == NULL);
+    assert(stripes[1].read_buf == rmw_buf+128*1024);
+    assert(stripes[2].read_buf == NULL);
+    assert(stripes[0].write_buf == write_buf);
+    assert(stripes[1].write_buf == write_buf+128*1024);
+    assert(stripes[2].write_buf == rmw_buf);
+    // Test 8.2
+    set_pattern(write_buf, 128*1024+4096, PATTERN0);
+    set_pattern(stripes[1].read_buf, 128*1024-4096, PATTERN1);
+    calc_rmw_parity_xor(stripes, 3, osd_set, write_osd_set, 128*1024);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 128*1024); // recheck again
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 4096);     // recheck again
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 128*1024); // recheck again
+    assert(stripes[0].write_buf == write_buf);                               // recheck again
+    assert(stripes[1].write_buf == write_buf+128*1024);                      // recheck again
+    assert(stripes[2].write_buf == rmw_buf);                                 // recheck again
+    check_pattern(stripes[2].write_buf, 4096, 0); // new parity
+    check_pattern(stripes[2].write_buf+4096, 128*1024-4096, PATTERN0^PATTERN1); // new parity
+    free(rmw_buf);
+    free(write_buf);
+}
+
+void test9()
+{
+    osd_num_t osd_set[3] = { 0, 2, 3 };
+    osd_num_t write_osd_set[3] = { 1, 2, 3 };
+    osd_rmw_stripe_t stripes[3] = { 0 };
+    // Test 9.0
+    split_stripes(2, 128*1024, 64*1024, 0, stripes);
+    assert(stripes[0].req_start == 0 && stripes[0].req_end == 0);
+    assert(stripes[1].req_start == 0 && stripes[1].req_end == 0);
+    assert(stripes[2].req_start == 0 && stripes[2].req_end == 0);
+    // Test 9.1
+    void *write_buf = NULL;
+    void *rmw_buf = calc_rmw(write_buf, stripes, osd_set, 3, 2, 3, write_osd_set, 128*1024);
+    assert(stripes[0].read_start == 0 && stripes[0].read_end == 128*1024);
+    assert(stripes[1].read_start == 0 && stripes[1].read_end == 128*1024);
+    assert(stripes[2].read_start == 0 && stripes[2].read_end == 128*1024);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 0);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 0);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 0);
+    assert(stripes[0].read_buf == rmw_buf);
+    assert(stripes[1].read_buf == rmw_buf+128*1024);
+    assert(stripes[2].read_buf == rmw_buf+128*1024*2);
+    assert(stripes[0].write_buf == NULL);
+    assert(stripes[1].write_buf == NULL);
+    assert(stripes[2].write_buf == NULL);
+    // Test 9.2
+    set_pattern(stripes[1].read_buf, 128*1024, 0);
+    set_pattern(stripes[2].read_buf, 128*1024, PATTERN1);
+    calc_rmw_parity_xor(stripes, 3, osd_set, write_osd_set, 128*1024);
+    assert(stripes[0].write_start == 0 && stripes[0].write_end == 128*1024);
+    assert(stripes[1].write_start == 0 && stripes[1].write_end == 0);
+    assert(stripes[2].write_start == 0 && stripes[2].write_end == 0);
+    assert(stripes[0].write_buf == rmw_buf);
+    assert(stripes[1].write_buf == NULL);
+    assert(stripes[2].write_buf == NULL);
+    check_pattern(stripes[0].read_buf, 128*1024, PATTERN1);
+    check_pattern(stripes[0].write_buf, 128*1024, PATTERN1);
+    free(rmw_buf);
 }

osd_secondary.cpp

@@ -1,64 +1,59 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include "osd.h"
 
 #include "json11/json11.hpp"
 
 void osd_t::secondary_op_callback(osd_op_t *op)
 {
-    inflight_ops--;
-    auto cl_it = clients.find(op->peer_fd);
-    if (cl_it != clients.end())
+    if (op->req.hdr.opcode == OSD_OP_SEC_READ ||
+        op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+        op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
     {
-        op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
-        op->reply.hdr.id = op->req.hdr.id;
-        op->reply.hdr.opcode = op->req.hdr.opcode;
-        op->reply.hdr.retval = op->bs_op->retval;
-        if (op->req.hdr.opcode == OSD_OP_SECONDARY_READ ||
-            op->req.hdr.opcode == OSD_OP_SECONDARY_WRITE)
-        {
-            op->reply.sec_rw.version = op->bs_op->version;
-        }
-        else if (op->req.hdr.opcode == OSD_OP_SECONDARY_DELETE)
-        {
-            op->reply.sec_del.version = op->bs_op->version;
-        }
-        if (op->req.hdr.opcode == OSD_OP_SECONDARY_READ &&
-            op->reply.hdr.retval > 0)
-        {
-            op->send_list.push_back(op->buf, op->reply.hdr.retval);
-        }
-        else if (op->req.hdr.opcode == OSD_OP_SECONDARY_LIST)
-        {
-            // allocated by blockstore
-            op->buf = op->bs_op->buf;
-            if (op->reply.hdr.retval > 0)
-            {
-                op->send_list.push_back(op->buf, op->reply.hdr.retval * sizeof(obj_ver_id));
-            }
-            op->reply.sec_list.stable_count = op->bs_op->version;
-        }
-        auto & cl = cl_it->second;
-        outbox_push(cl, op);
+        op->reply.sec_rw.version = op->bs_op->version;
     }
-    else
+    else if (op->req.hdr.opcode == OSD_OP_SEC_DELETE)
     {
-        delete op;
+        op->reply.sec_del.version = op->bs_op->version;
     }
+    if (op->req.hdr.opcode == OSD_OP_SEC_READ &&
+        op->bs_op->retval > 0)
+    {
+        op->iov.push_back(op->buf, op->bs_op->retval);
+    }
+    else if (op->req.hdr.opcode == OSD_OP_SEC_LIST)
+    {
+        // allocated by blockstore
+        op->buf = op->bs_op->buf;
+        if (op->bs_op->retval > 0)
+        {
+            op->iov.push_back(op->buf, op->bs_op->retval * sizeof(obj_ver_id));
+        }
+        op->reply.sec_list.stable_count = op->bs_op->version;
+    }
+    int retval = op->bs_op->retval;
+    delete op->bs_op;
+    op->bs_op = NULL;
+    finish_op(op, retval);
 }
 
 void osd_t::exec_secondary(osd_op_t *cur_op)
 {
     cur_op->bs_op = new blockstore_op_t();
     cur_op->bs_op->callback = [this, cur_op](blockstore_op_t* bs_op) { secondary_op_callback(cur_op); };
-    cur_op->bs_op->opcode = (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_READ ? BS_OP_READ
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_WRITE ? BS_OP_WRITE
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_SYNC ? BS_OP_SYNC
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_STABILIZE ? BS_OP_STABLE
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_ROLLBACK ? BS_OP_ROLLBACK
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_DELETE ? BS_OP_DELETE
-        : (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_LIST ? BS_OP_LIST
-        : -1)))))));
-    if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_READ ||
-        cur_op->req.hdr.opcode == OSD_OP_SECONDARY_WRITE)
+    cur_op->bs_op->opcode = (cur_op->req.hdr.opcode == OSD_OP_SEC_READ ? BS_OP_READ
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE ? BS_OP_WRITE
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE ? BS_OP_WRITE_STABLE
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_SYNC ? BS_OP_SYNC
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_STABILIZE ? BS_OP_STABLE
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK ? BS_OP_ROLLBACK
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_DELETE ? BS_OP_DELETE
+        : (cur_op->req.hdr.opcode == OSD_OP_SEC_LIST ? BS_OP_LIST
+        : -1))))))));
+    if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+        cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+        cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
     {
         cur_op->bs_op->oid = cur_op->req.sec_rw.oid;
         cur_op->bs_op->version = cur_op->req.sec_rw.version;
@@ -69,7 +64,7 @@ void osd_t::exec_secondary(osd_op_t *cur_op)
         cur_op->bs_op->retval = cur_op->bs_op->len;
 #endif
     }
-    else if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_DELETE)
+    else if (cur_op->req.hdr.opcode == OSD_OP_SEC_DELETE)
     {
         cur_op->bs_op->oid = cur_op->req.sec_del.oid;
         cur_op->bs_op->version = cur_op->req.sec_del.version;
@@ -77,8 +72,8 @@ void osd_t::exec_secondary(osd_op_t *cur_op)
         cur_op->bs_op->retval = 0;
 #endif
     }
-    else if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_STABILIZE ||
-        cur_op->req.hdr.opcode == OSD_OP_SECONDARY_ROLLBACK)
+    else if (cur_op->req.hdr.opcode == OSD_OP_SEC_STABILIZE ||
+        cur_op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK)
     {
         cur_op->bs_op->len = cur_op->req.sec_stab.len/sizeof(obj_ver_id);
         cur_op->bs_op->buf = cur_op->buf;
@@ -86,18 +81,21 @@ void osd_t::exec_secondary(osd_op_t *cur_op)
         cur_op->bs_op->retval = 0;
 #endif
     }
-    else if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_LIST)
+    else if (cur_op->req.hdr.opcode == OSD_OP_SEC_LIST)
     {
         if (cur_op->req.sec_list.pg_count < cur_op->req.sec_list.list_pg)
         {
             // requested pg number is greater than total pg count
+            printf("Invalid LIST request: pg count %u < pg number %u\n", cur_op->req.sec_list.pg_count, cur_op->req.sec_list.list_pg);
             cur_op->bs_op->retval = -EINVAL;
             secondary_op_callback(cur_op);
             return;
         }
-        cur_op->bs_op->oid.stripe = cur_op->req.sec_list.parity_block_size;
+        cur_op->bs_op->oid.stripe = cur_op->req.sec_list.pg_stripe_size;
         cur_op->bs_op->len = cur_op->req.sec_list.pg_count;
         cur_op->bs_op->offset = cur_op->req.sec_list.list_pg - 1;
+        cur_op->bs_op->oid.inode = cur_op->req.sec_list.min_inode;
+        cur_op->bs_op->version = cur_op->req.sec_list.max_inode;
 #ifdef OSD_STUB
         cur_op->bs_op->retval = 0;
         cur_op->bs_op->buf = NULL;
@@ -114,15 +112,10 @@ void osd_t::exec_show_config(osd_op_t *cur_op)
 {
     // FIXME: Send the real config, not its source
     std::string cfg_str = json11::Json(config).dump();
-    cur_op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
-    cur_op->reply.hdr.id = cur_op->req.hdr.id;
-    cur_op->reply.hdr.opcode = cur_op->req.hdr.opcode;
-    cur_op->reply.hdr.retval = cfg_str.size()+1;
-    cur_op->buf = malloc(cfg_str.size()+1);
+    cur_op->buf = malloc_or_die(cfg_str.size()+1);
     memcpy(cur_op->buf, cfg_str.c_str(), cfg_str.size()+1);
-    auto & cl = clients[cur_op->peer_fd];
-    cur_op->send_list.push_back(cur_op->buf, cur_op->reply.hdr.retval);
-    outbox_push(cl, cur_op);
+    cur_op->iov.push_back(cur_op->buf, cfg_str.size()+1);
+    finish_op(cur_op, cfg_str.size()+1);
 }
 
 void osd_t::exec_sync_stab_all(osd_op_t *cur_op)

osd_send.cpp

@@ -1,133 +0,0 @@
-#include "osd.h"
-
-void osd_t::outbox_push(osd_client_t & cl, osd_op_t *cur_op)
-{
-    assert(cur_op->peer_fd);
-    if (cur_op->op_type == OSD_OP_OUT)
-    {
-        clock_gettime(CLOCK_REALTIME, &cur_op->tv_begin);
-    }
-    cl.outbox.push_back(cur_op);
-    if (cl.write_op || cl.outbox.size() > 1 || !try_send(cl))
-    {
-        if (cl.write_state == 0)
-        {
-            cl.write_state = CL_WRITE_READY;
-            write_ready_clients.push_back(cur_op->peer_fd);
-        }
-        ringloop->wakeup();
-    }
-}
-
-bool osd_t::try_send(osd_client_t & cl)
-{
-    int peer_fd = cl.peer_fd;
-    io_uring_sqe* sqe = ringloop->get_sqe();
-    if (!sqe)
-    {
-        return false;
-    }
-    ring_data_t* data = ((ring_data_t*)sqe->user_data);
-    if (!cl.write_op)
-    {
-        // pick next command
-        cl.write_op = cl.outbox.front();
-        cl.outbox.pop_front();
-        cl.write_state = CL_WRITE_REPLY;
-        clock_gettime(CLOCK_REALTIME, &cl.write_op->tv_send);
-        if (cl.write_op->op_type == OSD_OP_IN)
-        {
-            // Measure execution latency
-            timespec tv_end = cl.write_op->tv_send;
-            op_stat_count[cl.write_op->req.hdr.opcode]++;
-            op_stat_sum[cl.write_op->req.hdr.opcode] += (
-                (tv_end.tv_sec - cl.write_op->tv_begin.tv_sec)*1000000 +
-                (tv_end.tv_nsec - cl.write_op->tv_begin.tv_nsec)/1000
-            );
-        }
-    }
-    cl.write_msg.msg_iov = cl.write_op->send_list.get_iovec();
-    cl.write_msg.msg_iovlen = cl.write_op->send_list.get_size();
-    data->callback = [this, peer_fd](ring_data_t *data) { handle_send(data, peer_fd); };
-    my_uring_prep_sendmsg(sqe, cl.peer_fd_index, &cl.write_msg, 0);
-    sqe->flags |= IOSQE_FIXED_FILE;
-    return true;
-}
-
-void osd_t::send_replies()
-{
-    for (int i = 0; i < write_ready_clients.size(); i++)
-    {
-        int peer_fd = write_ready_clients[i];
-        if (!try_send(clients[peer_fd]))
-        {
-            write_ready_clients.erase(write_ready_clients.begin(), write_ready_clients.begin() + i);
-            return;
-        }
-    }
-    write_ready_clients.clear();
-}
-
-void osd_t::handle_send(ring_data_t *data, int peer_fd)
-{
-    int res = data->res;
-    auto cl_it = clients.find(peer_fd);
-    if (cl_it != clients.end())
-    {
-        auto & cl = cl_it->second;
-        if (res < 0 && res != -EAGAIN)
-        {
-            // this is a client socket, so don't panic. just disconnect it
-            printf("Client %d socket write error: %d (%s). Disconnecting client\n", peer_fd, -res, strerror(-res));
-            stop_client(peer_fd);
-            return;
-        }
-        if (res >= 0)
-        {
-            osd_op_t *cur_op = cl.write_op;
-            while (res > 0 && cur_op->send_list.sent < cur_op->send_list.count)
-            {
-                iovec & iov = cur_op->send_list.buf[cur_op->send_list.sent];
-                if (iov.iov_len <= res)
-                {
-                    res -= iov.iov_len;
-                    cur_op->send_list.sent++;
-                }
-                else
-                {
-                    iov.iov_len -= res;
-                    iov.iov_base += res;
-                    break;
-                }
-            }
-            if (cur_op->send_list.sent >= cur_op->send_list.count)
-            {
-                // Done
-                if (cur_op->req.hdr.opcode == OSD_OP_SECONDARY_STABILIZE)
-                {
-                    timespec tv_end;
-                    clock_gettime(CLOCK_REALTIME, &tv_end);
-                    send_stat_count++;
-                    send_stat_sum += (
-                        (tv_end.tv_sec - cl.write_op->tv_send.tv_sec)*1000000 +
-                        (tv_end.tv_nsec - cl.write_op->tv_send.tv_nsec)/1000
-                    );
-                }
-                if (cur_op->op_type == OSD_OP_IN)
-                {
-                    delete cur_op;
-                }
-                else
-                {
-                    cl.sent_ops[cl.write_op->req.hdr.id] = cl.write_op;
-                }
-                cl.write_op = NULL;
-                cl.write_state = cl.outbox.size() > 0 ? CL_WRITE_READY : 0;
-            }
-        }
-        if (cl.write_state != 0)
-        {
-            write_ready_clients.push_back(peer_fd);
-        }
-    }
-}

osd_test.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -19,6 +22,8 @@
 
 int connect_osd(const char *osd_address, int osd_port);
 
+uint64_t test_read(int connect_fd, uint64_t inode, uint64_t stripe, uint64_t version, uint64_t offset, uint64_t len);
+
 uint64_t test_write(int connect_fd, uint64_t inode, uint64_t stripe, uint64_t version, uint64_t pattern);
 
 void* test_primary_read(int connect_fd, uint64_t inode, uint64_t offset, uint64_t len);
@@ -29,6 +34,8 @@ void test_primary_sync(int connect_fd);
 
 void test_sync_stab_all(int connect_fd);
 
+void test_list_stab(int connect_fd);
+
 int main0(int narg, char *args[])
 {
     int connect_fd;
@@ -94,7 +101,16 @@ int main2(int narg, char *args[])
     return 0;
 }
 
-int main(int narg, char *args[])
+int main3(int narg, char *args[])
+{
+    int connect_fd;
+    connect_fd = connect_osd("127.0.0.1", 11203);
+    test_list_stab(connect_fd);
+    close(connect_fd);
+    return 0;
+}
+
+int main4(int narg, char *args[])
 {
     int connect_fd;
     // Cluster write (sync not implemented yet)
@@ -106,6 +122,15 @@ int main(int narg, char *args[])
     return 0;
 }
 
+int main(int narg, char *args[])
+{
+    int connect_fd;
+    connect_fd = connect_osd("192.168.7.2", 43051);
+    test_read(connect_fd, 1, 1039663104, UINT64_MAX, 0, 128*1024);
+    close(connect_fd);
+    return 0;
+}
+
 int connect_osd(const char *osd_address, int osd_port)
 {
     struct sockaddr_in addr;
@@ -148,7 +173,7 @@ bool check_reply(int r, osd_any_op_t & op, osd_any_reply_t & reply, int expected
         printf("bad reply: magic, id or opcode does not match request\n");
         return false;
     }
-    if (reply.hdr.retval != expected)
+    if (expected >= 0 && reply.hdr.retval != expected)
     {
         printf("operation failed, retval=%ld\n", reply.hdr.retval);
         return false;
@@ -156,13 +181,73 @@ bool check_reply(int r, osd_any_op_t & op, osd_any_reply_t & reply, int expected
     return true;
 }
 
+uint64_t test_read(int connect_fd, uint64_t inode, uint64_t stripe, uint64_t version, uint64_t offset, uint64_t len)
+{
+    osd_any_op_t op;
+    osd_any_reply_t reply;
+    op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
+    op.hdr.id = 1;
+    op.hdr.opcode = OSD_OP_SEC_READ;
+    op.sec_rw.oid = {
+        .inode = inode,
+        .stripe = stripe,
+    };
+    op.sec_rw.version = version;
+    op.sec_rw.offset = offset;
+    op.sec_rw.len = len;
+    void *data = memalign(MEM_ALIGNMENT, op.sec_rw.len);
+    write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE);
+    int r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
+    if (!check_reply(r, op, reply, op.sec_rw.len))
+    {
+        free(data);
+        return 0;
+    }
+    r = read_blocking(connect_fd, data, len);
+    if (r != len)
+    {
+        free(data);
+        perror("read data");
+        return 0;
+    }
+    free(data);
+    printf("Read %lx:%lx v%lu = v%lu\n", inode, stripe, version, reply.sec_rw.version);
+    op.hdr.opcode = OSD_OP_SEC_LIST;
+    op.sec_list.list_pg = 1;
+    op.sec_list.pg_count = 1;
+    op.sec_list.pg_stripe_size = 4*1024*1024;
+    write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE);
+    r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
+    if (reply.hdr.retval < 0 || !check_reply(r, op, reply, reply.hdr.retval))
+    {
+        return 0;
+    }
+    data = memalign(MEM_ALIGNMENT, sizeof(obj_ver_id)*reply.hdr.retval);
+    r = read_blocking(connect_fd, data, sizeof(obj_ver_id)*reply.hdr.retval);
+    if (r != sizeof(obj_ver_id)*reply.hdr.retval)
+    {
+        free(data);
+        perror("read data");
+        return 0;
+    }
+    obj_ver_id *ov = (obj_ver_id*)data;
+    for (int i = 0; i < reply.hdr.retval; i++)
+    {
+        if (ov[i].oid.inode == inode && (ov[i].oid.stripe & ~(4096-1)) == (stripe & ~(4096-1)))
+        {
+            printf("list: %lx:%lx v%lu stable=%d\n", ov[i].oid.inode, ov[i].oid.stripe, ov[i].version, i < reply.sec_list.stable_count ? 1 : 0);
+        }
+    }
+    return 0;
+}
+
 uint64_t test_write(int connect_fd, uint64_t inode, uint64_t stripe, uint64_t version, uint64_t pattern)
 {
     osd_any_op_t op;
     osd_any_reply_t reply;
     op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
     op.hdr.id = 1;
-    op.hdr.opcode = OSD_OP_SECONDARY_WRITE;
+    op.hdr.opcode = OSD_OP_SEC_WRITE;
     op.sec_rw.oid = {
         .inode = inode,
         .stripe = stripe,
@@ -170,7 +255,7 @@ uint64_t test_write(int connect_fd, uint64_t inode, uint64_t stripe, uint64_t ve
     op.sec_rw.version = version;
     op.sec_rw.offset = 0;
     op.sec_rw.len = 128*1024;
-    void *data = memalign(512, op.sec_rw.len);
+    void *data = memalign(MEM_ALIGNMENT, op.sec_rw.len);
     for (int i = 0; i < (op.sec_rw.len)/sizeof(uint64_t); i++)
         ((uint64_t*)data)[i] = pattern;
     write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE);
@@ -205,7 +290,7 @@ void* test_primary_read(int connect_fd, uint64_t inode, uint64_t offset, uint64_
     op.rw.inode = inode;
     op.rw.offset = offset;
     op.rw.len = len;
-    void *data = memalign(512, len);
+    void *data = memalign(MEM_ALIGNMENT, len);
     write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE);
     int r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
     if (!check_reply(r, op, reply, len))
@@ -233,7 +318,7 @@ void test_primary_write(int connect_fd, uint64_t inode, uint64_t offset, uint64_
     op.rw.inode = inode;
     op.rw.offset = offset;
     op.rw.len = len;
-    void *data = memalign(512, len);
+    void *data = memalign(MEM_ALIGNMENT, len);
     set_pattern(data, len, pattern);
     write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE);
     write_blocking(connect_fd, data, len);
@@ -265,3 +350,40 @@ void test_sync_stab_all(int connect_fd)
     int r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
     assert(check_reply(r, op, reply, 0));
 }
+
+void test_list_stab(int connect_fd)
+{
+    osd_any_op_t op;
+    osd_any_reply_t reply;
+    op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
+    op.hdr.id = 1;
+    op.hdr.opcode = OSD_OP_SEC_LIST;
+    op.sec_list.pg_count = 0;
+    assert(write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE) == OSD_PACKET_SIZE);
+    int r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
+    assert(check_reply(r, op, reply, -1));
+    int total_count = reply.hdr.retval;
+    int stable_count = reply.sec_list.stable_count;
+    obj_ver_id *data = (obj_ver_id*)malloc(total_count * sizeof(obj_ver_id));
+    assert(data);
+    assert(read_blocking(connect_fd, data, total_count * sizeof(obj_ver_id)) == (total_count * sizeof(obj_ver_id)));
+    int last_start = stable_count;
+    for (int i = stable_count; i <= total_count; i++)
+    {
+        // Stabilize in portions of 32 entries
+        if (i - last_start >= 32 || i == total_count)
+        {
+            op.hdr.opcode = OSD_OP_SEC_STABILIZE;
+            op.sec_stab.len = sizeof(obj_ver_id) * (i - last_start);
+            assert(write_blocking(connect_fd, op.buf, OSD_PACKET_SIZE) == OSD_PACKET_SIZE);
+            assert(write_blocking(connect_fd, data + last_start, op.sec_stab.len) == op.sec_stab.len);
+            r = read_blocking(connect_fd, reply.buf, OSD_PACKET_SIZE);
+            assert(check_reply(r, op, reply, 0));
+            last_start = i;
+        }
+    }
+    obj_ver_id *data2 = (obj_ver_id*)malloc(sizeof(obj_ver_id) * 32);
+    assert(data2);
+    free(data2);
+    free(data);
+}

pg_states.cpp

@@ -0,0 +1,38 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#include "pg_states.h"
+
+const int pg_state_bit_count = 14;
+
+const int pg_state_bits[14] = {
+    PG_STARTING,
+    PG_PEERING,
+    PG_INCOMPLETE,
+    PG_ACTIVE,
+    PG_STOPPING,
+    PG_OFFLINE,
+    PG_DEGRADED,
+    PG_HAS_INCOMPLETE,
+    PG_HAS_DEGRADED,
+    PG_HAS_MISPLACED,
+    PG_HAS_UNCLEAN,
+    PG_HAS_INVALID,
+    PG_LEFT_ON_DEAD,
+};
+
+const char *pg_state_names[14] = {
+    "starting",
+    "peering",
+    "incomplete",
+    "active",
+    "stopping",
+    "offline",
+    "degraded",
+    "has_incomplete",
+    "has_degraded",
+    "has_misplaced",
+    "has_unclean",
+    "has_invalid",
+    "left_on_dead",
+};

pg_states.h

@@ -0,0 +1,37 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+// Placement group states
+// STARTING -> [acquire lock] -> PEERING -> INCOMPLETE|ACTIVE -> STOPPING -> OFFLINE -> [release lock]
+// Exactly one of these:
+#define PG_STARTING (1<<0)
+#define PG_PEERING (1<<1)
+#define PG_INCOMPLETE (1<<2)
+#define PG_ACTIVE (1<<3)
+#define PG_STOPPING (1<<4)
+#define PG_OFFLINE (1<<5)
+// Plus any of these:
+#define PG_DEGRADED (1<<6)
+#define PG_HAS_INCOMPLETE (1<<7)
+#define PG_HAS_DEGRADED (1<<8)
+#define PG_HAS_MISPLACED (1<<9)
+#define PG_HAS_UNCLEAN (1<<10)
+#define PG_HAS_INVALID (1<<11)
+#define PG_LEFT_ON_DEAD (1<<12)
+
+// Lower bits that represent object role (EC 0/1/2... or always 0 with replication)
+// 12 bits is a safe default that doesn't depend on pg_stripe_size or pg_block_size
+#define STRIPE_MASK ((uint64_t)4096 - 1)
+
+// OSD object states
+#define OBJ_DEGRADED 0x02
+#define OBJ_INCOMPLETE 0x04
+#define OBJ_MISPLACED 0x08
+#define OBJ_NEEDS_STABLE 0x10000
+#define OBJ_NEEDS_ROLLBACK 0x20000
+
+extern const int pg_state_bits[];
+extern const char *pg_state_names[];
+extern const int pg_state_bit_count;

qemu_driver.c

@@ -0,0 +1,400 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+// QEMU block driver
+
+#define _GNU_SOURCE
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "block/block_int.h"
+#include "block/qdict.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/uri.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "qemu/option.h"
+#include "qemu/cutils.h"
+
+#include "qemu_proxy.h"
+
+typedef struct VitastorClient
+{
+    void *proxy;
+    char *etcd_host;
+    char *etcd_prefix;
+    uint64_t inode;
+    uint64_t pool;
+    uint64_t size;
+    int readonly;
+    QemuMutex mutex;
+} VitastorClient;
+
+typedef struct VitastorRPC
+{
+    BlockDriverState *bs;
+    Coroutine *co;
+    QEMUIOVector *iov;
+    int ret;
+    int complete;
+} VitastorRPC;
+
+static char *qemu_rbd_next_tok(char *src, char delim, char **p)
+{
+    char *end;
+    *p = NULL;
+    for (end = src; *end; ++end)
+    {
+        if (*end == delim)
+            break;
+        if (*end == '\\' && end[1] != '\0')
+            end++;
+    }
+    if (*end == delim)
+    {
+        *p = end + 1;
+        *end = '\0';
+    }
+    return src;
+}
+
+static void qemu_rbd_unescape(char *src)
+{
+    char *p;
+    for (p = src; *src; ++src, ++p)
+    {
+        if (*src == '\\' && src[1] != '\0')
+            src++;
+        *p = *src;
+    }
+    *p = '\0';
+}
+
+// vitastor[:key=value]*
+// vitastor:etcd_host=127.0.0.1:inode=1:pool=1
+static void vitastor_parse_filename(const char *filename, QDict *options, Error **errp)
+{
+    const char *start;
+    char *p, *buf;
+
+    if (!strstart(filename, "vitastor:", &start))
+    {
+        error_setg(errp, "File name must start with 'vitastor:'");
+        return;
+    }
+
+    buf = g_strdup(start);
+    p = buf;
+
+    // The following are all key/value pairs
+    while (p)
+    {
+        char *name, *value;
+        name = qemu_rbd_next_tok(p, '=', &p);
+        if (!p)
+        {
+            error_setg(errp, "conf option %s has no value", name);
+            break;
+        }
+        qemu_rbd_unescape(name);
+        value = qemu_rbd_next_tok(p, ':', &p);
+        qemu_rbd_unescape(value);
+        if (!strcmp(name, "inode") || !strcmp(name, "pool") || !strcmp(name, "size"))
+        {
+            unsigned long long num_val;
+            if (parse_uint_full(value, &num_val, 0))
+            {
+                error_setg(errp, "Illegal %s: %s", name, value);
+                goto out;
+            }
+            qdict_put_int(options, name, num_val);
+        }
+        else
+        {
+            qdict_put_str(options, name, value);
+        }
+    }
+    if (!qdict_get_try_int(options, "inode", 0))
+    {
+        error_setg(errp, "inode is missing");
+        goto out;
+    }
+    if (!(qdict_get_try_int(options, "inode", 0) >> (64-POOL_ID_BITS)) &&
+        !qdict_get_try_int(options, "pool", 0))
+    {
+        error_setg(errp, "pool number is missing");
+        goto out;
+    }
+    if (!qdict_get_try_int(options, "size", 0))
+    {
+        error_setg(errp, "size is missing");
+        goto out;
+    }
+    if (!qdict_get_str(options, "etcd_host"))
+    {
+        error_setg(errp, "etcd_host is missing");
+        goto out;
+    }
+
+out:
+    g_free(buf);
+    return;
+}
+
+static int vitastor_file_open(BlockDriverState *bs, QDict *options, int flags, Error **errp)
+{
+    VitastorClient *client = bs->opaque;
+    int64_t ret = 0;
+    client->etcd_host = g_strdup(qdict_get_try_str(options, "etcd_host"));
+    client->etcd_prefix = g_strdup(qdict_get_try_str(options, "etcd_prefix"));
+    client->inode = qdict_get_int(options, "inode");
+    client->pool = qdict_get_int(options, "pool");
+    if (client->pool)
+        client->inode = (client->inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (client->pool << (64-POOL_ID_BITS));
+    client->size = qdict_get_int(options, "size");
+    client->readonly = (flags & BDRV_O_RDWR) ? 1 : 0;
+    client->proxy = vitastor_proxy_create(bdrv_get_aio_context(bs), client->etcd_host, client->etcd_prefix);
+    //client->aio_context = bdrv_get_aio_context(bs);
+    bs->total_sectors = client->size / BDRV_SECTOR_SIZE;
+    qdict_del(options, "etcd_host");
+    qdict_del(options, "etcd_prefix");
+    qdict_del(options, "inode");
+    qdict_del(options, "pool");
+    qdict_del(options, "size");
+    qemu_mutex_init(&client->mutex);
+    return ret;
+}
+
+static void vitastor_close(BlockDriverState *bs)
+{
+    VitastorClient *client = bs->opaque;
+    vitastor_proxy_destroy(client->proxy);
+    qemu_mutex_destroy(&client->mutex);
+    g_free(client->etcd_host);
+    if (client->etcd_prefix)
+        g_free(client->etcd_prefix);
+}
+
+static int vitastor_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
+{
+    bsz->phys = 4096;
+    bsz->log = 4096;
+    return 0;
+}
+
+static int coroutine_fn vitastor_co_create_opts(
+#if QEMU_VERSION_MAJOR >= 4
+    BlockDriver *drv,
+#endif
+    const char *url, QemuOpts *opts, Error **errp)
+{
+    QDict *options;
+    int ret;
+
+    options = qdict_new();
+    vitastor_parse_filename(url, options, errp);
+    if (*errp)
+    {
+        ret = -1;
+        goto out;
+    }
+
+    // inodes don't require creation in Vitastor. FIXME: They will when there will be some metadata
+
+    ret = 0;
+out:
+    qobject_unref(options);
+    return ret;
+}
+
+static int coroutine_fn vitastor_co_truncate(BlockDriverState *bs, int64_t offset,
+#if QEMU_VERSION_MAJOR >= 4
+    bool exact,
+#endif
+    PreallocMode prealloc, Error **errp)
+{
+    VitastorClient *client = bs->opaque;
+
+    if (prealloc != PREALLOC_MODE_OFF)
+    {
+        error_setg(errp, "Unsupported preallocation mode '%s'", PreallocMode_str(prealloc));
+        return -ENOTSUP;
+    }
+
+    // TODO: Resize inode to <offset> bytes
+    client->size = offset / BDRV_SECTOR_SIZE;
+
+    return 0;
+}
+
+static int vitastor_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+    bdi->cluster_size = 4096;
+    return 0;
+}
+
+static int64_t vitastor_getlength(BlockDriverState *bs)
+{
+    VitastorClient *client = bs->opaque;
+    return client->size;
+}
+
+static void vitastor_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    bs->bl.request_alignment = 4096;
+    bs->bl.min_mem_alignment = 4096;
+    bs->bl.opt_mem_alignment = 4096;
+}
+
+static int64_t vitastor_get_allocated_file_size(BlockDriverState *bs)
+{
+    return 0;
+}
+
+static void vitastor_co_init_task(BlockDriverState *bs, VitastorRPC *task)
+{
+    *task = (VitastorRPC) {
+        .co     = qemu_coroutine_self(),
+        .bs     = bs,
+    };
+}
+
+static void vitastor_co_generic_bh_cb(int retval, void *opaque)
+{
+    VitastorRPC *task = opaque;
+    task->ret = retval;
+    task->complete = 1;
+    if (qemu_coroutine_self() != task->co)
+    {
+        aio_co_wake(task->co);
+    }
+}
+
+static int coroutine_fn vitastor_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *iov, int flags)
+{
+    VitastorClient *client = bs->opaque;
+    VitastorRPC task;
+    vitastor_co_init_task(bs, &task);
+    task.iov = iov;
+
+    qemu_mutex_lock(&client->mutex);
+    vitastor_proxy_rw(0, client->proxy, client->inode, offset, bytes, iov->iov, iov->niov, vitastor_co_generic_bh_cb, &task);
+    qemu_mutex_unlock(&client->mutex);
+
+    while (!task.complete)
+    {
+        qemu_coroutine_yield();
+    }
+
+    return task.ret;
+}
+
+static int coroutine_fn vitastor_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *iov, int flags)
+{
+    VitastorClient *client = bs->opaque;
+    VitastorRPC task;
+    vitastor_co_init_task(bs, &task);
+    task.iov = iov;
+
+    qemu_mutex_lock(&client->mutex);
+    vitastor_proxy_rw(1, client->proxy, client->inode, offset, bytes, iov->iov, iov->niov, vitastor_co_generic_bh_cb, &task);
+    qemu_mutex_unlock(&client->mutex);
+
+    while (!task.complete)
+    {
+        qemu_coroutine_yield();
+    }
+
+    return task.ret;
+}
+
+static int coroutine_fn vitastor_co_flush(BlockDriverState *bs)
+{
+    VitastorClient *client = bs->opaque;
+    VitastorRPC task;
+    vitastor_co_init_task(bs, &task);
+
+    qemu_mutex_lock(&client->mutex);
+    vitastor_proxy_sync(client->proxy, vitastor_co_generic_bh_cb, &task);
+    qemu_mutex_unlock(&client->mutex);
+
+    while (!task.complete)
+    {
+        qemu_coroutine_yield();
+    }
+
+    return task.ret;
+}
+
+static QemuOptsList vitastor_create_opts = {
+    .name = "vitastor-create-opts",
+    .head = QTAILQ_HEAD_INITIALIZER(vitastor_create_opts.head),
+    .desc = {
+        {
+            .name = BLOCK_OPT_SIZE,
+            .type = QEMU_OPT_SIZE,
+            .help = "Virtual disk size"
+        },
+        { /* end of list */ }
+    }
+};
+
+static const char *vitastor_strong_runtime_opts[] = {
+    "inode",
+    "pool",
+    "etcd_host",
+    "etcd_prefix",
+
+    NULL
+};
+
+static BlockDriver bdrv_vitastor = {
+    .format_name                    = "vitastor",
+    .protocol_name                  = "vitastor",
+
+    .instance_size                  = sizeof(VitastorClient),
+    .bdrv_parse_filename            = vitastor_parse_filename,
+
+    .bdrv_has_zero_init             = bdrv_has_zero_init_1,
+#if QEMU_VERSION_MAJOR >= 4
+    .bdrv_has_zero_init_truncate    = bdrv_has_zero_init_1,
+#endif
+    .bdrv_get_info                  = vitastor_get_info,
+    .bdrv_getlength                 = vitastor_getlength,
+    .bdrv_probe_blocksizes          = vitastor_probe_blocksizes,
+    .bdrv_refresh_limits            = vitastor_refresh_limits,
+
+    // FIXME: Implement it along with per-inode statistics
+    //.bdrv_get_allocated_file_size   = vitastor_get_allocated_file_size,
+
+    .bdrv_file_open                 = vitastor_file_open,
+    .bdrv_close                     = vitastor_close,
+
+    // Option list for the create operation
+    .create_opts                    = &vitastor_create_opts,
+
+    // For qmp_blockdev_create(), used by the qemu monitor / QAPI
+    // Requires patching QAPI IDL, thus unimplemented
+    //.bdrv_co_create                 = vitastor_co_create,
+
+    // For bdrv_create(), used by qemu-img
+    .bdrv_co_create_opts            = vitastor_co_create_opts,
+
+    .bdrv_co_truncate               = vitastor_co_truncate,
+
+    .bdrv_co_preadv                 = vitastor_co_preadv,
+    .bdrv_co_pwritev                = vitastor_co_pwritev,
+    .bdrv_co_flush_to_disk          = vitastor_co_flush,
+
+#if QEMU_VERSION_MAJOR >= 4
+    .strong_runtime_opts            = vitastor_strong_runtime_opts,
+#endif
+};
+
+static void vitastor_block_init(void)
+{
+    bdrv_register(&bdrv_vitastor);
+}
+
+block_init(vitastor_block_init);

qemu_proxy.cpp

@@ -0,0 +1,130 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+// C-C++ proxy for the QEMU driver
+// (QEMU headers don't compile with g++)
+
+#include <sys/epoll.h>
+
+#include "cluster_client.h"
+
+typedef void* AioContext;
+#include "qemu_proxy.h"
+
+extern "C"
+{
+    // QEMU
+    typedef void IOHandler(void *opaque);
+    void aio_set_fd_handler(AioContext *ctx, int fd, int is_external, IOHandler *fd_read, IOHandler *fd_write, void *poll_fn, void *opaque);
+}
+
+struct QemuProxyData
+{
+    int fd;
+    std::function<void(int, int)> callback;
+};
+
+class QemuProxy
+{
+    std::map<int, QemuProxyData> handlers;
+
+public:
+
+    timerfd_manager_t *tfd;
+    cluster_client_t *cli;
+    AioContext *ctx;
+
+    QemuProxy(AioContext *ctx, const char *etcd_host, const char *etcd_prefix)
+    {
+        this->ctx = ctx;
+        json11::Json cfg = json11::Json::object {
+            { "etcd_address", std::string(etcd_host) },
+            { "etcd_prefix", std::string(etcd_prefix ? etcd_prefix : "/vitastor") },
+        };
+        tfd = new timerfd_manager_t([this](int fd, bool wr, std::function<void(int, int)> callback) { set_fd_handler(fd, wr, callback); });
+        cli = new cluster_client_t(NULL, tfd, cfg);
+    }
+
+    ~QemuProxy()
+    {
+        cli->stop();
+        delete cli;
+        delete tfd;
+    }
+
+    void set_fd_handler(int fd, bool wr, std::function<void(int, int)> callback)
+    {
+        if (callback != NULL)
+        {
+            handlers[fd] = { .fd = fd, .callback = callback };
+            aio_set_fd_handler(ctx, fd, false, &QemuProxy::read_handler, wr ? &QemuProxy::write_handler : NULL, NULL, &handlers[fd]);
+        }
+        else
+        {
+            handlers.erase(fd);
+            aio_set_fd_handler(ctx, fd, false, NULL, NULL, NULL, NULL);
+        }
+    }
+
+    static void read_handler(void *opaque)
+    {
+        QemuProxyData *data = (QemuProxyData *)opaque;
+        data->callback(data->fd, EPOLLIN);
+    }
+
+    static void write_handler(void *opaque)
+    {
+        QemuProxyData *data = (QemuProxyData *)opaque;
+        data->callback(data->fd, EPOLLOUT);
+    }
+};
+
+extern "C" {
+
+void* vitastor_proxy_create(AioContext *ctx, const char *etcd_host, const char *etcd_prefix)
+{
+    QemuProxy *p = new QemuProxy(ctx, etcd_host, etcd_prefix);
+    return p;
+}
+
+void vitastor_proxy_destroy(void *client)
+{
+    QemuProxy *p = (QemuProxy*)client;
+    delete p;
+}
+
+void vitastor_proxy_rw(int write, void *client, uint64_t inode, uint64_t offset, uint64_t len,
+    iovec *iov, int iovcnt, VitastorIOHandler cb, void *opaque)
+{
+    QemuProxy *p = (QemuProxy*)client;
+    cluster_op_t *op = new cluster_op_t;
+    op->opcode = write ? OSD_OP_WRITE : OSD_OP_READ;
+    op->inode = inode;
+    op->offset = offset;
+    op->len = len;
+    for (int i = 0; i < iovcnt; i++)
+    {
+        op->iov.push_back(iov[i].iov_base, iov[i].iov_len);
+    }
+    op->callback = [cb, opaque](cluster_op_t *op)
+    {
+        cb(op->retval, opaque);
+        delete op;
+    };
+    p->cli->execute(op);
+}
+
+void vitastor_proxy_sync(void *client, VitastorIOHandler cb, void *opaque)
+{
+    QemuProxy *p = (QemuProxy*)client;
+    cluster_op_t *op = new cluster_op_t;
+    op->opcode = OSD_OP_SYNC;
+    op->callback = [cb, opaque](cluster_op_t *op)
+    {
+        cb(op->retval, opaque);
+        delete op;
+    };
+    p->cli->execute(op);
+}
+
+}

qemu_proxy.h

@@ -0,0 +1,29 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+#ifndef VITASTOR_QEMU_PROXY_H
+#define VITASTOR_QEMU_PROXY_H
+
+#ifndef POOL_ID_BITS
+#define POOL_ID_BITS 16
+#endif
+#include <stdint.h>
+#include <sys/uio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Our exports
+typedef void VitastorIOHandler(int retval, void *opaque);
+void* vitastor_proxy_create(AioContext *ctx, const char *etcd_host, const char *etcd_prefix);
+void vitastor_proxy_destroy(void *client);
+void vitastor_proxy_rw(int write, void *client, uint64_t inode, uint64_t offset, uint64_t len,
+    struct iovec *iov, int iovcnt, VitastorIOHandler cb, void *opaque);
+void vitastor_proxy_sync(void *client, VitastorIOHandler cb, void *opaque);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

ringloop.cpp

@@ -1,19 +1,17 @@
-#include <set>
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
 
 #include "ringloop.h"
 
 ring_loop_t::ring_loop_t(int qd)
 {
-    io_uring_params params = { 0 };
-    params.flags = IORING_SETUP_SQPOLL;
-    params.sq_thread_idle = 10;
-    int ret = io_uring_queue_init_params(qd, &ring, &params);
+    int ret = io_uring_queue_init(qd, &ring, 0);
     if (ret < 0)
     {
         throw std::runtime_error(std::string("io_uring_queue_init: ") + strerror(-ret));
     }
-    ring_data_total = free_ring_data_ptr = *ring.cq.kring_entries;
-    ring_datas = (ring_data_t*)malloc(sizeof(ring_data_t) * free_ring_data_ptr);
+    free_ring_data_ptr = *ring.cq.kring_entries;
+    ring_datas = (struct ring_data_t*)malloc(sizeof(ring_data_t) * free_ring_data_ptr);
     free_ring_data = (int*)malloc(sizeof(int) * free_ring_data_ptr);
     if (!ring_datas || !free_ring_data)
     {
@@ -21,9 +19,9 @@ ring_loop_t::ring_loop_t(int qd)
     }
     for (int i = 0; i < free_ring_data_ptr; i++)
     {
-        ring_datas[i] = { 0 };
         free_ring_data[i] = i;
     }
+    wait_sqe_id = 1;
 }
 
 ring_loop_t::~ring_loop_t()
@@ -33,110 +31,10 @@ ring_loop_t::~ring_loop_t()
     io_uring_queue_exit(&ring);
 }
 
-void ring_loop_t::drain_events(void *completions_ptr)
+void ring_loop_t::register_consumer(ring_consumer_t *consumer)
 {
-    std::set<ring_data_t*> & completions = *((std::set<ring_data_t*> *)completions_ptr);
-    if (free_ring_data_ptr < ring_data_total)
-    {
-        // Try to cancel requests that are allowed to be canceled by the caller (epoll, timerfd and similar)
-        for (int i = 0; i < ring_data_total; i++)
-        {
-            if (ring_datas[i].allow_cancel)
-            {
-                // allow_cancel may only be true while the operation is inflight
-                io_uring_sqe *sqe = get_sqe();
-                if (!sqe)
-                {
-                    throw std::runtime_error("can't get SQE to cancel operation");
-                }
-                ring_data_t *data = (ring_data_t*)sqe->user_data;
-                data->callback = NULL;
-                ring_datas[i].res = -ECANCELED;
-                my_uring_prep_cancel(sqe, &ring_datas[i], 0);
-                // It seems (FIXME) cancel operations don't always get completions
-                completions.insert(data);
-            }
-        }
-        if (completions.size() > 0)
-        {
-            submit();
-        }
-    }
-    int inflight = ring_data_total - free_ring_data_ptr;
-    while (completions.size() < inflight)
-    {
-        io_uring_cqe *cqe;
-        while (!io_uring_peek_cqe(&ring, &cqe))
-        {
-            ring_data_t *d = (ring_data_t*)cqe->user_data;
-            d->res = cqe->res;
-            d->allow_cancel = false;
-            completions.insert(d);
-            io_uring_cqe_seen(&ring, cqe);
-        }
-        if (completions.size() < inflight)
-        {
-            wait();
-        }
-    }
-}
-
-void ring_loop_t::run_completions(void *completions_ptr)
-{
-    std::set<ring_data_t*> & completions = *((std::set<ring_data_t*> *)completions_ptr);
-    // Call event callbacks
-    for (ring_data_t *d: completions)
-    {
-        free_ring_data[free_ring_data_ptr++] = d - ring_datas;
-        if (d->callback)
-            d->callback(d);
-    }
-}
-
-int ring_loop_t::register_fd(int fd)
-{
-    std::set<ring_data_t*> completions;
-    drain_events((void*)&completions);
-    // Modify registered files
-    int idx = reg_fds.size();
-    reg_fds.push_back(fd);
-    if (registered)
-    {
-        io_uring_unregister_files(&ring);
-    }
-    int ret = io_uring_register_files(&ring, reg_fds.data(), reg_fds.size());
-    if (ret != 0)
-    {
-        throw std::runtime_error(std::string("io_uring_register_files_update: ") + strerror(-ret));
-    }
-    registered = 1;
-    run_completions((void*)&completions);
-    return idx;
-}
-
-void ring_loop_t::unregister_fd(int fd_index)
-{
-    std::set<ring_data_t*> completions;
-    drain_events((void*)&completions);
-    // Modify registered files
-    reg_fds.erase(reg_fds.begin()+fd_index, reg_fds.begin()+fd_index+1);
-    if (registered)
-    {
-        io_uring_unregister_files(&ring);
-    }
-    int ret = io_uring_register_files(&ring, reg_fds.data(), reg_fds.size());
-    if (ret != 0)
-    {
-        throw std::runtime_error(std::string("io_uring_register_files_update: ") + strerror(-ret));
-    }
-    run_completions((void*)&completions);
-}
-
-int ring_loop_t::register_consumer(ring_consumer_t & consumer)
-{
-    consumer.number = consumers.size();
+    unregister_consumer(consumer);
     consumers.push_back(consumer);
-    return consumer.number;
 }
 
 void ring_loop_t::wakeup()
@@ -144,34 +42,43 @@ void ring_loop_t::wakeup()
     loop_again = true;
 }
 
-void ring_loop_t::unregister_consumer(ring_consumer_t & consumer)
+void ring_loop_t::unregister_consumer(ring_consumer_t *consumer)
 {
-    if (consumer.number >= 0 && consumer.number < consumers.size())
+    for (int i = 0; i < consumers.size(); i++)
     {
-        consumers[consumer.number].loop = NULL;
-        consumer.number = -1;
+        if (consumers[i] == consumer)
+        {
+            consumers.erase(consumers.begin()+i, consumers.begin()+i+1);
+            break;
+        }
     }
 }
 
 void ring_loop_t::loop()
 {
-    io_uring_cqe *cqe;
+    struct io_uring_cqe *cqe;
     while (!io_uring_peek_cqe(&ring, &cqe))
     {
-        ring_data_t *d = (ring_data_t*)cqe->user_data;
-        d->res = cqe->res;
-        d->allow_cancel = false;
-        io_uring_cqe_seen(&ring, cqe);
-        free_ring_data[free_ring_data_ptr++] = d - ring_datas;
+        struct ring_data_t *d = (struct ring_data_t*)cqe->user_data;
         if (d->callback)
+        {
+            d->res = cqe->res;
             d->callback(d);
+        }
+        free_ring_data[free_ring_data_ptr++] = d - ring_datas;
+        io_uring_cqe_seen(&ring, cqe);
+    }
+    while (get_sqe_queue.size() > 0)
+    {
+        (get_sqe_queue[0].second)();
+        get_sqe_queue.erase(get_sqe_queue.begin());
     }
     do
     {
         loop_again = false;
         for (int i = 0; i < consumers.size(); i++)
         {
-            consumers[i].loop();
+            consumers[i]->loop();
         }
     } while (loop_again);
 }

ringloop.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #pragma once
 
 #ifndef _LARGEFILE64_SOURCE
@@ -107,53 +110,55 @@ static inline void my_uring_prep_cancel(struct io_uring_sqe *sqe, void *user_dat
 struct ring_data_t
 {
     struct iovec iov; // for single-entry read/write operations
-    bool allow_cancel;
     int res;
     std::function<void(ring_data_t*)> callback;
 };
 
 struct ring_consumer_t
 {
-    int number;
     std::function<void(void)> loop;
 };
 
 class ring_loop_t
 {
-    std::vector<ring_consumer_t> consumers;
+    std::vector<std::pair<int,std::function<void()>>> get_sqe_queue;
+    std::vector<ring_consumer_t*> consumers;
     struct ring_data_t *ring_datas;
     int *free_ring_data;
-    unsigned free_ring_data_ptr, ring_data_total;
+    int wait_sqe_id;
+    unsigned free_ring_data_ptr;
     bool loop_again;
     struct io_uring ring;
-    int registered = 0;
-    std::vector<int> reg_fds;
-    void drain_events(void *completions_ptr);
-    void run_completions(void *completions_ptr);
-
 public:
     ring_loop_t(int qd);
     ~ring_loop_t();
-    int register_consumer(ring_consumer_t & consumer);
-    void unregister_consumer(ring_consumer_t & consumer);
-
-    int register_fd(int fd);
-    void unregister_fd(int fd_index);
+    void register_consumer(ring_consumer_t *consumer);
+    void unregister_consumer(ring_consumer_t *consumer);
 
     inline struct io_uring_sqe* get_sqe()
     {
         if (free_ring_data_ptr == 0)
-        {
             return NULL;
-        }
         struct io_uring_sqe* sqe = io_uring_get_sqe(&ring);
         if (sqe)
-        {
-            ring_data_t *data = ring_datas + free_ring_data[--free_ring_data_ptr];
-            io_uring_sqe_set_data(sqe, data);
-        }
+            io_uring_sqe_set_data(sqe, ring_datas + free_ring_data[--free_ring_data_ptr]);
         return sqe;
     }
+    inline int wait_sqe(std::function<void()> cb)
+    {
+        get_sqe_queue.push_back({ wait_sqe_id, cb });
+        return wait_sqe_id++;
+    }
+    inline void cancel_wait_sqe(int wait_id)
+    {
+        for (int i = 0; i < get_sqe_queue.size(); i++)
+        {
+            if (get_sqe_queue[i].first == wait_id)
+            {
+                get_sqe_queue.erase(get_sqe_queue.begin()+i, get_sqe_queue.begin()+i+1);
+            }
+        }
+    }
     inline int submit()
     {
         return io_uring_submit(&ring);
@@ -167,7 +172,7 @@ public:
     {
         return free_ring_data_ptr;
     }
-    inline bool get_loop_again()
+    inline bool has_work()
     {
         return loop_again;
     }

rw_blocking.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -51,6 +54,40 @@ int write_blocking(int fd, void *write_buf, size_t remaining)
     return done;
 }
 
+int readv_blocking(int fd, iovec *iov, int iovcnt)
+{
+    int v = 0;
+    int done = 0;
+    while (v < iovcnt)
+    {
+        ssize_t r = readv(fd, iov, iovcnt);
+        if (r < 0)
+        {
+            if (errno != EAGAIN && errno != EPIPE)
+            {
+                perror("writev");
+                exit(1);
+            }
+            continue;
+        }
+        while (v < iovcnt)
+        {
+            if (iov[v].iov_len > r)
+            {
+                iov[v].iov_len -= r;
+                iov[v].iov_base += r;
+                break;
+            }
+            else
+            {
+                v++;
+            }
+        }
+        done += r;
+    }
+    return done;
+}
+
 int writev_blocking(int fd, iovec *iov, int iovcnt)
 {
     int v = 0;

rw_blocking.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #pragma once
 
 #include <unistd.h>
@@ -5,4 +8,5 @@
 
 int read_blocking(int fd, void *read_buf, size_t remaining);
 int write_blocking(int fd, void *write_buf, size_t remaining);
+int readv_blocking(int fd, iovec *iov, int iovcnt);
 int writev_blocking(int fd, iovec *iov, int iovcnt);

stub_bench.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 /**
  * Stub benchmarker
  */
@@ -25,20 +28,37 @@ int connect_stub(const char *server_address, int server_port);
 
 void run_bench(int peer_fd);
 
+static uint64_t read_sum = 0, read_count = 0;
 static uint64_t write_sum = 0, write_count = 0;
 static uint64_t sync_sum = 0, sync_count = 0;
 
 void handle_sigint(int sig)
 {
-    printf("4k randwrite: %lu us avg\n", write_sum/write_count);
-    printf("sync: %lu us avg\n", sync_sum/sync_count);
+    printf("4k randread: %lu us avg\n", read_count ? read_sum/read_count : 0);
+    printf("4k randwrite: %lu us avg\n", write_count ? write_sum/write_count : 0);
+    printf("sync: %lu us avg\n", sync_count ? sync_sum/sync_count : 0);
     exit(0);
 }
 
 int main(int narg, char *args[])
 {
+    if (narg < 2)
+    {
+        printf("USAGE: %s SERVER_IP [PORT]\n", args[0]);
+        return 1;
+    }
+    int port = 11203;
+    if (narg >= 3)
+    {
+        port = atoi(args[2]);
+        if (port <= 0 || port >= 65536)
+        {
+            printf("Bad port number\n");
+            return 1;
+        }
+    }
     signal(SIGINT, handle_sigint);
-    int peer_fd = connect_stub("127.0.0.1", 11203);
+    int peer_fd = connect_stub(args[1], port);
     run_bench(peer_fd);
     close(peer_fd);
     return 0;
@@ -98,14 +118,41 @@ void run_bench(int peer_fd)
     osd_any_reply_t reply;
     void *buf = NULL;
     int r;
+    iovec iov[2];
     timespec tv_begin, tv_end;
     clock_gettime(CLOCK_REALTIME, &tv_begin);
     while (1)
     {
+        // read
+        op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
+        op.hdr.id = 1;
+        op.hdr.opcode = OSD_OP_SEC_READ;
+        op.sec_rw.oid.inode = 3;
+        op.sec_rw.oid.stripe = (rand() << 17) % (1 << 29); // 512 MB
+        op.sec_rw.version = 0;
+        op.sec_rw.len = 4096;
+        op.sec_rw.offset = (rand() * op.sec_rw.len) % (1 << 17);
+        r = write_blocking(peer_fd, op.buf, OSD_PACKET_SIZE) == OSD_PACKET_SIZE;
+        if (!r)
+            break;
+        buf = malloc(op.sec_rw.len);
+        iov[0] = { reply.buf, OSD_PACKET_SIZE };
+        iov[1] = { buf, op.sec_rw.len };
+        r = readv_blocking(peer_fd, iov, 2) == (OSD_PACKET_SIZE + op.sec_rw.len);
+        free(buf);
+        if (!r || !check_reply(OSD_PACKET_SIZE, op, reply, op.sec_rw.len))
+            break;
+        clock_gettime(CLOCK_REALTIME, &tv_end);
+        read_count++;
+        read_sum += (
+            (tv_end.tv_sec - tv_begin.tv_sec)*1000000 +
+            tv_end.tv_nsec/1000 - tv_begin.tv_nsec/1000
+        );
+        tv_begin = tv_end;
         // write
         op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
         op.hdr.id = 1;
-        op.hdr.opcode = OSD_OP_SECONDARY_WRITE;
+        op.hdr.opcode = OSD_OP_SEC_WRITE;
         op.sec_rw.oid.inode = 3;
         op.sec_rw.oid.stripe = (rand() << 17) % (1 << 29); // 512 MB
         op.sec_rw.version = 0;
@@ -113,9 +160,9 @@ void run_bench(int peer_fd)
         op.sec_rw.offset = (rand() * op.sec_rw.len) % (1 << 17);
         buf = malloc(op.sec_rw.len);
         memset(buf, rand() % 255, op.sec_rw.len);
-        r = write_blocking(peer_fd, op.buf, OSD_PACKET_SIZE) == OSD_PACKET_SIZE;
-        if (r)
-            r = write_blocking(peer_fd, buf, op.sec_rw.len) == op.sec_rw.len;
+        iov[0] = { op.buf, OSD_PACKET_SIZE };
+        iov[1] = { buf, op.sec_rw.len };
+        r = writev_blocking(peer_fd, iov, 2) == (OSD_PACKET_SIZE + op.sec_rw.len);
         free(buf);
         if (!r)
             break;
@@ -128,6 +175,7 @@ void run_bench(int peer_fd)
             (tv_end.tv_sec - tv_begin.tv_sec)*1000000 +
             tv_end.tv_nsec/1000 - tv_begin.tv_nsec/1000
         );
+        tv_begin = tv_end;
         // sync/stab
         op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
         op.hdr.id = 1;
@@ -138,11 +186,12 @@ void run_bench(int peer_fd)
         r = read_blocking(peer_fd, reply.buf, OSD_PACKET_SIZE);
         if (!check_reply(r, op, reply, 0))
             break;
-        clock_gettime(CLOCK_REALTIME, &tv_begin);
+        clock_gettime(CLOCK_REALTIME, &tv_end);
         sync_count++;
         sync_sum += (
-            (tv_begin.tv_sec - tv_end.tv_sec)*1000000 +
-            tv_begin.tv_nsec/1000 - tv_end.tv_nsec/1000
+            (tv_end.tv_sec - tv_begin.tv_sec)*1000000 +
+            tv_end.tv_nsec/1000 - tv_begin.tv_nsec/1000
         );
+        tv_begin = tv_end;
     }
 }

stub_osd.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 /**
  * Stub "OSD" to test & compare network performance with sync read/write and io_uring
  *
@@ -130,7 +133,7 @@ void run_stub(int peer_fd)
         reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
         reply.hdr.id = op.hdr.id;
         reply.hdr.opcode = op.hdr.opcode;
-        if (op.hdr.opcode == OSD_OP_SECONDARY_READ)
+        if (op.hdr.opcode == OSD_OP_SEC_READ)
         {
             reply.hdr.retval = op.sec_rw.len;
             buf = malloc(op.sec_rw.len);
@@ -141,7 +144,7 @@ void run_stub(int peer_fd)
             if (r < op.sec_rw.len)
                 break;
         }
-        else if (op.hdr.opcode == OSD_OP_SECONDARY_WRITE)
+        else if (op.hdr.opcode == OSD_OP_SEC_WRITE || op.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
         {
             buf = malloc(op.sec_rw.len);
             r = read_blocking(peer_fd, buf, op.sec_rw.len);

stub_uring_osd.cpp

@@ -0,0 +1,131 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
+/**
+ * Stub "OSD" implemented on top of osd_messenger to test & compare
+ * network performance with sync read/write and io_uring
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include <stdexcept>
+
+#include "ringloop.h"
+#include "epoll_manager.h"
+#include "messenger.h"
+
+int bind_stub(const char *bind_address, int bind_port);
+
+void stub_exec_op(osd_messenger_t *msgr, osd_op_t *op);
+
+int main(int narg, char *args[])
+{
+    ring_consumer_t looper;
+    ring_loop_t *ringloop = new ring_loop_t(512);
+    epoll_manager_t *epmgr = new epoll_manager_t(ringloop);
+    osd_messenger_t *msgr = new osd_messenger_t();
+    msgr->osd_num = 1351;
+    msgr->tfd = epmgr->tfd;
+    msgr->ringloop = ringloop;
+    msgr->repeer_pgs = [](osd_num_t) {};
+    msgr->exec_op = [msgr](osd_op_t *op) { stub_exec_op(msgr, op); };
+    // Accept new connections
+    int listen_fd = bind_stub("0.0.0.0", 11203);
+    epmgr->set_fd_handler(listen_fd, false, [listen_fd, msgr](int fd, int events)
+    {
+        msgr->accept_connections(listen_fd);
+    });
+    looper.loop = [msgr, ringloop]()
+    {
+        msgr->read_requests();
+        msgr->send_replies();
+        ringloop->submit();
+    };
+    ringloop->register_consumer(&looper);
+    printf("stub_uring_osd: waiting for clients\n");
+    while (true)
+    {
+        ringloop->loop();
+        ringloop->wait();
+    }
+    delete msgr;
+    delete epmgr;
+    delete ringloop;
+    return 0;
+}
+
+int bind_stub(const char *bind_address, int bind_port)
+{
+    int listen_backlog = 128;
+
+    int listen_fd = socket(AF_INET, SOCK_STREAM, 0);
+    if (listen_fd < 0)
+    {
+        throw std::runtime_error(std::string("socket: ") + strerror(errno));
+    }
+    int enable = 1;
+    setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable));
+
+    sockaddr_in addr;
+    int r;
+    if ((r = inet_pton(AF_INET, bind_address, &addr.sin_addr)) != 1)
+    {
+        close(listen_fd);
+        throw std::runtime_error("bind address "+std::string(bind_address)+(r == 0 ? " is not valid" : ": no ipv4 support"));
+    }
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(bind_port);
+
+    if (bind(listen_fd, (sockaddr*)&addr, sizeof(addr)) < 0)
+    {
+        close(listen_fd);
+        throw std::runtime_error(std::string("bind: ") + strerror(errno));
+    }
+
+    if (listen(listen_fd, listen_backlog) < 0)
+    {
+        close(listen_fd);
+        throw std::runtime_error(std::string("listen: ") + strerror(errno));
+    }
+
+    fcntl(listen_fd, F_SETFL, fcntl(listen_fd, F_GETFL, 0) | O_NONBLOCK);
+
+    return listen_fd;
+}
+
+void stub_exec_op(osd_messenger_t *msgr, osd_op_t *op)
+{
+    op->reply.hdr.magic = SECONDARY_OSD_REPLY_MAGIC;
+    op->reply.hdr.id = op->req.hdr.id;
+    op->reply.hdr.opcode = op->req.hdr.opcode;
+    if (op->req.hdr.opcode == OSD_OP_SEC_READ)
+    {
+        op->reply.hdr.retval = op->req.sec_rw.len;
+        op->buf = malloc(op->req.sec_rw.len);
+        op->iov.push_back(op->buf, op->req.sec_rw.len);
+    }
+    else if (op->req.hdr.opcode == OSD_OP_SEC_WRITE || op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
+    {
+        op->reply.hdr.retval = op->req.sec_rw.len;
+    }
+    else if (op->req.hdr.opcode == OSD_OP_TEST_SYNC_STAB_ALL)
+    {
+        op->reply.hdr.retval = 0;
+    }
+    else
+    {
+        printf("client %d: unsupported stub opcode: %lu\n", op->peer_fd, op->req.hdr.opcode);
+        op->reply.hdr.retval = -EINVAL;
+    }
+    msgr->outbox_push(op);
+}

test.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #define _LARGEFILE64_SOURCE
 #include <sys/types.h>
 #include <sys/ioctl.h>
@@ -13,6 +16,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <liburing.h>
+#include <math.h>
 
 #include <sys/socket.h>
 #include <sys/epoll.h>
@@ -61,24 +65,6 @@ static void test_write(struct io_uring *ring, int fd)
     free(buf);
 }
 
-class obj_ver_hash
-{
-public:
-    size_t operator()(const obj_ver_id &s) const
-    {
-        size_t seed = 0;
-        spp::hash_combine(seed, s.oid.inode);
-        spp::hash_combine(seed, s.oid.stripe);
-        spp::hash_combine(seed, s.version);
-        return seed;
-    }
-};
-
-inline bool operator == (const obj_ver_id & a, const obj_ver_id & b)
-{
-    return a.oid == b.oid && a.version == b.version;
-}
-
 int main00(int argc, char *argv[])
 {
     // queue with random removal: vector is best :D
@@ -170,9 +156,9 @@ int main0(int argc, char *argv[])
     // btree_map 5M entries monotone -> 0.458s, random -> 5.429s
     // absl::btree_map 5M entries random -> 5.09s
     // sparse_hash_map 5M entries -> 2.193s, random -> 2.586s
-    //btree::btree_map<obj_ver_id, dirty_entry> dirty_db;
+    btree::btree_map<obj_ver_id, dirty_entry> dirty_db;
     //std::map<obj_ver_id, dirty_entry> dirty_db;
-    spp::sparse_hash_map<obj_ver_id, dirty_entry, obj_ver_hash> dirty_db;
+    //spp::sparse_hash_map<obj_ver_id, dirty_entry, obj_ver_hash> dirty_db;
     for (int i = 0; i < 5000000; i++)
     {
         dirty_db[(obj_ver_id){
@@ -182,7 +168,7 @@ int main0(int argc, char *argv[])
             },
             .version = 1,
         }] = (dirty_entry){
-            .state = ST_D_META_SYNCED,
+            .state = ST_D_SYNCED,
             .flags = 0,
             .location = (uint64_t)i << 17,
             .offset = 0,
@@ -337,87 +323,253 @@ int main04(int argc, char *argv[])
     return 0;
 }
 
-int main05(int argc, char *argv[])
+uint64_t jumphash(uint64_t key, int count)
 {
-    // FIXME extract this into a test
-    pg_t pg = {
-        .state = PG_PEERING,
-        .pg_num = 1,
-        .target_set = { 1, 2, 3 },
-        .cur_set = { 1, 2, 3 },
-        .peering_state = new pg_peering_state_t(),
-    };
-    for (uint64_t osd_num = 1; osd_num <= 3; osd_num++)
+    uint64_t b = 0;
+    uint64_t seed = key;
+    for (int j = 1; j < count; j++)
     {
-        pg_list_result_t r = {
-            .buf = (obj_ver_id*)malloc(sizeof(obj_ver_id) * 1024*1024*8),
-            .total_count = 1024*1024*8,
-            .stable_count = (uint64_t)(1024*1024*8 - (osd_num == 1 ? 10 : 0)),
-        };
-        for (uint64_t i = 0; i < r.total_count; i++)
+        seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+        if (seed < (UINT64_MAX / (j+1)))
         {
-            r.buf[i] = {
-                .oid = {
-                    .inode = 1,
-                    .stripe = (i << STRIPE_SHIFT) | (osd_num-1),
-                },
-                .version = (uint64_t)(osd_num == 1 && i >= r.total_count - 10 ? 2 : 1),
-            };
+            b = j;
         }
-        pg.peering_state->list_results[osd_num] = r;
     }
-    pg.calc_object_states();
-    printf("deviation variants=%ld clean=%lu\n", pg.state_dict.size(), pg.clean_count);
-    for (auto it: pg.state_dict)
+    return b;
+}
+
+void jumphash_prepare(int count, uint64_t *out_weights, uint64_t *in_weights)
+{
+    if (count <= 0)
     {
-        printf("dev: state=%lx\n", it.second.state);
+        return;
+    }
+    uint64_t total_weight = in_weights[0];
+    out_weights[0] = UINT64_MAX;
+    for (int j = 1; j < count; j++)
+    {
+        total_weight += in_weights[j];
+        out_weights[j] = UINT64_MAX / total_weight * in_weights[j];
+    }
+}
+
+uint64_t jumphash_weights(uint64_t key, int count, uint64_t *prepared_weights)
+{
+    uint64_t b = 0;
+    uint64_t seed = key;
+    for (int j = 1; j < count; j++)
+    {
+        seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+        if (seed < prepared_weights[j])
+        {
+            b = j;
+        }
+    }
+    return b;
+}
+
+void jumphash3(uint64_t key, int count, uint64_t *weights, uint64_t *r)
+{
+    r[0] = 0;
+    r[1] = 1;
+    r[2] = 2;
+    uint64_t total_weight = weights[0]+weights[1]+weights[2];
+    uint64_t seed = key;
+    for (int j = 3; j < count; j++)
+    {
+        seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+        total_weight += weights[j];
+        if (seed < UINT64_MAX*1.0*weights[j]/total_weight)
+            r[0] = j;
+        else
+        {
+            seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+            if (seed < UINT64_MAX*1.0*weights[j]/total_weight)
+                r[1] = j;
+            else
+            {
+                seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+                if (seed < UINT64_MAX*1.0*weights[j]/total_weight)
+                    r[2] = j;
+            }
+        }
+    }
+}
+
+uint64_t crush(uint64_t key, int count, uint64_t *weights)
+{
+    uint64_t b = 0;
+    uint64_t seed = 0;
+    uint64_t max = 0;
+    for (int j = 0; j < count; j++)
+    {
+        seed = (key + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+        seed ^= (j + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+        seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+        seed = -log(((double)seed) / (1ul << 32) / (1ul << 32)) * weights[j];
+        if (seed > max)
+        {
+            max = seed;
+            b = j;
+        }
+    }
+    return b;
+}
+
+void crush3(uint64_t key, int count, uint64_t *weights, uint64_t *r, uint64_t total_weight)
+{
+    uint64_t seed = 0;
+    uint64_t max = 0;
+    for (int k1 = 0; k1 < count; k1++)
+    {
+        for (int k2 = k1+1; k2 < count; k2++)
+        {
+            if (k2 == k1)
+            {
+                continue;
+            }
+            for (int k3 = k2+1; k3 < count; k3++)
+            {
+                if (k3 == k1 || k3 == k2)
+                {
+                    continue;
+                }
+                seed = (key + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+                seed ^= (k1 + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+                seed ^= (k2 + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+                seed ^= (k3 + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+                seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+                //seed = ((double)seed) / (1ul << 32) / (1ul << 32) * (weights[k1] + weights[k2] + weights[k3]);
+                seed = ((double)seed) / (1ul << 32) / (1ul << 32) * (1 -
+                    (1 - 1.0*weights[k1]/total_weight)*
+                    (1 - 1.0*weights[k2]/total_weight)*
+                    (1 - 1.0*weights[k3]/total_weight)
+                ) * UINT64_MAX;
+                if (seed > max)
+                {
+                    r[0] = k1;
+                    r[1] = k2;
+                    r[2] = k3;
+                    max = seed;
+                }
+            }
+        }
     }
-    return 0;
 }
 
 int main(int argc, char *argv[])
 {
-    timeval fill_start, fill_end, filter_end;
-    spp::sparse_hash_map<object_id, clean_entry> clean_db;
-    //std::map<object_id, clean_entry> clean_db;
-    //btree::btree_map<object_id, clean_entry> clean_db;
-    gettimeofday(&fill_start, NULL);
-    printf("filling\n");
-    uint64_t total = 1024*1024*8*4;
-    clean_db.resize(total);
-    for (uint64_t i = 0; i < total; i++)
+    int host_count = 6;
+    uint64_t host_weights[] = {
+        34609*3,
+        34931*3,
+        35850+36387+35859,
+        36387,
+        36387*2,
+        36387,
+    };
+    /*int osd_count[] = { 3, 3, 3, 1, 2 };
+    uint64_t osd_weights[][3] = {
+        { 34609, 34609, 34609 },
+        { 34931, 34931, 34931 },
+        { 35850, 36387, 35859 },
+        { 36387 },
+        { 36387, 36387 },
+    };*/
+    uint64_t total_weight = 0;
+    for (int i = 0; i < host_count; i++)
     {
-        clean_db[(object_id){
-            .inode = 1,
-            //.stripe = (i << STRIPE_SHIFT),
-            .stripe = (((367*i) % total) << STRIPE_SHIFT),
-        }] = (clean_entry){
-            .version = 1,
-            .location = i << DEFAULT_ORDER,
-        };
+        total_weight += host_weights[i];
     }
-    gettimeofday(&fill_end, NULL);
-    // no resize():
-    // spp = 17.87s (seq), 41.81s (rand), 3.29s (seq+resize), 8.3s (rand+resize), ~1.3G RAM in all cases
-    // std::unordered_map = 6.14 sec, ~2.3G RAM
-    // std::map = 13 sec (seq), 5.54 sec (rand), ~2.5G RAM
-    // cpp-btree = 2.47 sec (seq) ~1.2G RAM, 20.6 sec (pseudo-random 367*i % total) ~1.5G RAM
-    printf("filled %.2f sec\n", (fill_end.tv_sec - fill_start.tv_sec) + (fill_end.tv_usec - fill_start.tv_usec) / 1000000.0);
-    for (int pg = 0; pg < 100; pg++)
+    uint64_t host_weights_prepared[host_count];
+    jumphash_prepare(host_count, host_weights_prepared, host_weights);
+    uint64_t total_pgs[host_count] = { 0 };
+    int pg_count = 256;
+    double uniformity[pg_count] = { 0 };
+    for (uint64_t pg = 1; pg <= pg_count; pg++)
     {
-        obj_ver_id* buf1 = (obj_ver_id*)malloc(sizeof(obj_ver_id) * ((total+99)/100));
-        int j = 0;
-        for (auto it: clean_db)
-            if ((it.first % 100) == pg)
-                buf1[j++] = { .oid = it.first, .version = it.second.version };
-        free(buf1);
-        printf("filtered %d\n", j);
+        uint64_t r[3];
+
+/*
+        // Select first host
+        //r[0] = jumphash_weights(pg, host_count, host_weights_prepared);
+        r[0] = crush(pg, host_count, host_weights);
+        // Select second host
+        uint64_t seed = pg;
+        r[1] = r[0];
+        while (r[1] == r[0])
+        {
+            seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+            //r[1] = jumphash_weights(seed, host_count, host_weights_prepared);
+            r[1] = crush(seed, host_count, host_weights);
+        }
+        // Select third host
+        seed = pg;
+        r[2] = r[0];
+        while (r[2] == r[0] || r[2] == r[1])
+        {
+            seed = 2862933555777941757ull*seed + 3037000493ull; // LCPRNG
+            //r[2] = jumphash_weights(seed, host_count, host_weights_prepared);
+            r[2] = crush(seed, host_count, host_weights);
+        }
+*/
+
+/*
+        // Select second host
+        uint64_t host_weights1[host_count];
+        for (int i = 0; i < r[0]; i++)
+            host_weights1[i] = host_weights[i];
+        for (int i = r[0]+1; i < host_count; i++)
+            host_weights1[i-1] = host_weights[i];
+        r[1] = crush(pg, host_count-1, host_weights1);
+        // Select third host
+        for (int i = r[1]+1; i < host_count-1; i++)
+            host_weights1[i-1] = host_weights[i];
+        r[2] = crush(pg, host_count-2, host_weights1);
+        // Transform numbers
+        r[2] = r[2] >= r[1] ? 1+r[2] : r[2];
+        r[2] = r[2] >= r[0] ? 1+r[2] : r[2];
+        r[1] = r[1] >= r[0] ? 1+r[1] : r[1];
+*/
+
+        crush3(pg, host_count, host_weights, r, total_weight);
+        uint64_t shift = (2862933555777941757ull*pg + 3037000493ull) % host_count;
+        if (shift == 1)
+        {
+            uint64_t tmp;
+            tmp = r[0];
+            r[0] = r[1];
+            r[1] = r[2];
+            r[2] = tmp;
+        }
+        else if (shift == 2)
+        {
+            uint64_t tmp;
+            tmp = r[0];
+            r[0] = r[2];
+            r[2] = r[1];
+            r[1] = tmp;
+        }
+
+        total_pgs[r[0]]++;
+        total_pgs[r[1]]++;
+        total_pgs[r[2]]++;
+
+        double u = 0;
+        for (int i = 0; i < host_count; i++)
+        {
+            double d = abs(1 - total_pgs[i]/3.0/pg * total_weight/host_weights[i]);
+            u += d;
+        }
+        uniformity[pg-1] = u/host_count;
+
+        printf("pg %lu: hosts %lu, %lu, %lu ; avg deviation = %.2f\n", pg, r[0], r[1], r[2], u/host_count);
     }
-    gettimeofday(&filter_end, NULL);
-    // spp = 42.15 sec / 60 sec (rand)
-    // std::unordered_map = 43.7 sec
-    // std::map = 156.13 sec
-    // cpp-btree = 21.87 sec (seq), 44.33 sec (rand)
-    printf("100 times filter %.2f sec\n", (filter_end.tv_sec - fill_end.tv_sec) + (filter_end.tv_usec - fill_end.tv_usec) / 1000000.0);
+    printf("total PGs: ");
+    for (int i = 0; i < host_count; i++)
+    {
+        printf(i > 0 ? ", %lu (%.2f)" : "%lu (%.2f)", total_pgs[i], total_pgs[i]/3.0/pg_count * total_weight/host_weights[i]);
+    }
+    printf("\n");
     return 0;
 }

test_allocator.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <stdio.h>
 #include "allocator.h"
 

test_blockstore.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #include <malloc.h>
 #include "timerfd_interval.h"
 #include "blockstore.h"
@@ -115,7 +118,7 @@ int main(int narg, char *args[])
         }
     };
 
-    ringloop->register_consumer(main_cons);
+    ringloop->register_consumer(&main_cons);
     while (1)
     {
         ringloop->loop();

test_pattern.h

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 (see README.md for details)
+
 #pragma once
 
 #include <assert.h>

timerfd_interval.cpp

@@ -1,3 +1,6 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.0 or GNU GPL-2.0+ (see README.md for details)
+
 #include <sys/timerfd.h>
 #include <sys/poll.h>
 #include <unistd.h>
@@ -20,15 +23,14 @@ timerfd_interval::timerfd_interval(ring_loop_t *ringloop, int seconds, std::func
         throw std::runtime_error(std::string("timerfd_settime: ") + strerror(errno));
     }
     consumer.loop = [this]() { loop(); };
-    ringloop->register_consumer(consumer);
-    timerfd_index = ringloop->register_fd(timerfd);
+    ringloop->register_consumer(&consumer);
     this->ringloop = ringloop;
     this->callback = cb;
 }
 
 timerfd_interval::~timerfd_interval()
 {
-    ringloop->unregister_consumer(consumer);
+    ringloop->unregister_consumer(&consumer);
     close(timerfd);
 }
 
@@ -45,12 +47,10 @@ void timerfd_interval::loop()
         return;
     }
     struct ring_data_t *data = ((ring_data_t*)sqe->user_data);
-    my_uring_prep_poll_add(sqe, timerfd_index, POLLIN);
-    sqe->flags |= IOSQE_FIXED_FILE;
-    data->allow_cancel = true;
+    my_uring_prep_poll_add(sqe, timerfd, POLLIN);
     data->callback = [&](ring_data_t *data)
     {
-        if (data->res < 0 && data->res != -ECANCELED)
+        if (data->res < 0)
         {
             throw std::runtime_error(std::string("waiting for timer failed: ") + strerror(-data->res));
         }