Test: replace EPOLLIN with blocking sockets + io_uring reads

2020-03-01 17:23:14 +03:00
262 changed files with 5840 additions and 42286 deletions
--- a/.dockerignore
+++ b/.dockerignore
@ -1,19 +0,0 @@
 .git
 build
 packages
 mon/node_modules
 *.o
 *.so
 osd
 stub_osd
 stub_uring_osd
 stub_bench
 osd_test
 dump_journal
 nbd_proxy
 rm_inode
 fio
 qemu
 rpm/*.Dockerfile
 debian/*.Dockerfile
 Dockerfile
--- a/.gitignore
+++ b/.gitignore
@ -1,18 +0,0 @@
 *.o
 *.so
 package-lock.json
 fio
 qemu
 osd
 stub_osd
 stub_uring_osd
 stub_bench
 osd_test
 osd_peering_pg_test
 dump_journal
 nbd_proxy
 rm_inode
 test_allocator
 test_blockstore
 test_shit
 osd_rmw_test
--- a/.gitmodules
+++ b/.gitmodules
@ -1,6 +0,0 @@
 [submodule "cpp-btree"]
 	path = cpp-btree
 	url = ../cpp-btree.git
 [submodule "json11"]
 	path = json11
 	url = ../json11.git
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -1,7 +0,0 @@
 cmake_minimum_required(VERSION 2.8)
 project(vitastor)
 set(VERSION "0.6.10")
 add_subdirectory(src)
--- a/GPL-2.0.txt
+++ b/GPL-2.0.txt
@ -1,339 +0,0 @@
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--- a/27
+++ b/27
@ -1,27 +0,0 @@
 Copyright (c) Vitaliy Filippov (vitalif [at] yourcmc.ru), 2019+
 All server-side code (OSD, Monitor and so on) is licensed under the terms of
 Vitastor Network Public License 1.1 (VNPL 1.1), 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 and expressly designed to be used in conjunction
 with it ("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.
 Please note that VNPL doesn't require you to open the code of proprietary
 software running inside a VM if it's not specially designed to be used with
 Vitastor.
 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 1.1 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-1.1 in the file [VNPL-1.1.txt](VNPL-1.1.txt).
 GPL 2.0 is also included in this repository as [GPL-2.0.txt](GPL-2.0.txt).
--- a/64
+++ b/64
@ -0,0 +1,64 @@
 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
 # -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 osd_test
 clean:
 	rm -f *.o
 crc32c.o: crc32c.c
 	g++ $(CXXFLAGS) -c -o $@ $<
 json11.o: json11/json11.cpp
 	g++ $(CXXFLAGS) -c -o json11.o json11/json11.cpp
 allocator.o: allocator.cpp allocator.h
 	g++ $(CXXFLAGS) -c -o $@ $<
 ringloop.o: ringloop.cpp ringloop.h
 	g++ $(CXXFLAGS) -c -o $@ $<
 timerfd_interval.o: timerfd_interval.cpp timerfd_interval.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
 	g++ $(CXXFLAGS) -c -o $@ $<
 osd_receive.o: osd_receive.cpp osd.h osd_ops.h
 	g++ $(CXXFLAGS) -c -o $@ $<
 osd_send.o: osd_send.cpp osd.h osd_ops.h
 	g++ $(CXXFLAGS) -c -o $@ $<
 osd_peering.o: osd_peering.cpp osd.h osd_ops.h osd_peering_pg.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
 	g++ $(CXXFLAGS) -c -o $@ $<
 osd.o: osd.cpp osd.h osd_ops.h osd_peering_pg.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
 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
--- a/README-ru.md
+++ b/README-ru.md
@ -1,660 +0,0 @@
 ## Vitastor
 [Read English version](README.md)
 ## Идея
 Я всего лишь хочу сделать качественную блочную SDS!
 Vitastor - распределённая блочная SDS, прямой аналог Ceph RBD и внутренних СХД популярных
 облачных провайдеров. Однако, в отличие от них, Vitastor быстрый и при этом простой.
 Только пока маленький :-).
 Архитектурная схожесть с Ceph означает заложенную на уровне алгоритмов записи строгую консистентность,
 репликацию через первичный OSD, симметричную кластеризацию без единой точки отказа
 и автоматическое распределение данных по любому числу дисков любого размера с настраиваемыми схемами
 избыточности - репликацией или с произвольными кодами коррекции ошибок.
 ## Возможности
 Vitastor на данный момент находится в статусе предварительного выпуска, расширенные
 возможности пока отсутствуют, а в будущих версиях вероятны "ломающие" изменения.
 Однако следующее уже реализовано:
 - Базовая часть - надёжное кластерное блочное хранилище без единой точки отказа
 - Производительность ;-D
 - Несколько схем отказоустойчивости: репликация, XOR n+1 (1 диск чётности), коды коррекции ошибок
  Рида-Соломона на основе библиотеки jerasure с любым числом дисков данных и чётности в группе
 - Конфигурация через простые человекочитаемые JSON-структуры в etcd
 - Автоматическое распределение данных по OSD, с поддержкой:
  - Математической оптимизации для лучшей равномерности распределения и минимизации перемещений данных
  - Нескольких пулов с разными схемами избыточности
  - Дерева распределения, выбора OSD по тегам / классам устройств (только SSD, только HDD) и по поддереву
  - Настраиваемых доменов отказа (диск/сервер/стойка и т.п.)
 - Восстановление деградированных блоков
 - Ребаланс, то есть перемещение данных между OSD (дисками)
 - Поддержка "ленивого" fsync (fsync не на каждую операцию)
 - Сбор статистики ввода/вывода в etcd
 - Клиентская библиотека режима пользователя для ввода/вывода
 - Драйвер диска для QEMU (собирается вне дерева исходников QEMU)
 - Драйвер диска для утилиты тестирования производительности fio (также собирается вне дерева исходников fio)
 - NBD-прокси для монтирования образов ядром ("блочное устройство в режиме пользователя")
 - Утилита для удаления образов/инодов (vitastor-cli rm-data)
 - Пакеты для Debian и CentOS
 - Статистика операций ввода/вывода и занятого места в разрезе инодов
 - Именование инодов через хранение их метаданных в etcd
 - Снапшоты и copy-on-write клоны
 - Сглаживание производительности случайной записи в SSD+HDD конфигурациях
 - Поддержка RDMA/RoCEv2 через libibverbs
 - CSI-плагин для Kubernetes
 - Базовая поддержка OpenStack: драйвер Cinder, патчи для Nova и libvirt
 - Слияние снапшотов (vitastor-cli {snap-rm,flatten,merge})
 - Консольный интерфейс для управления образами (vitastor-cli {ls,create,modify})
 - Плагин для Proxmox
 ## Планы развития
 - Поддержка удаления снапшотов (слияния слоёв)
 - Более корректные скрипты разметки дисков и автоматического запуска OSD
 - Другие инструменты администрирования
 - Плагины для OpenNebula и других облачных систем
 - iSCSI-прокси
 - Более быстрое переключение при отказах
 - Фоновая проверка целостности без контрольных сумм (сверка реплик)
 - Контрольные суммы
 - Поддержка SSD-кэширования (tiered storage)
 - Поддержка NVDIMM
 - Web-интерфейс
 - Возможно, сжатие
 - Возможно, поддержка кэширования данных через системный page cache
 ## Архитектура
 Так же, как и в Ceph, в Vitastor:
 - Есть пулы (pools), PG, OSD, мониторы, домены отказа, дерево распределения (аналог crush-дерева).
 - Образы делятся на блоки фиксированного размера (объекты), и эти объекты распределяются по OSD.
 - У OSD есть журнал и метаданные и они тоже могут размещаться на отдельных быстрых дисках.
 - Все операции записи тоже транзакционны. В Vitastor, правда, есть режим отложенного/ленивого fsync
  (коммита), в котором fsync не вызывается на каждую операцию записи, что делает его более
  пригодным для использования на "плохих" (десктопных) SSD. Однако все операции записи
  в любом случае атомарны.
 - Клиентская библиотека тоже старается ждать восстановления после любого отказа кластера, то есть,
  вы тоже можете перезагрузить хоть весь кластер разом, и клиенты только на время зависнут,
  но не отключатся.
 Некоторые базовые термины для тех, кто не знаком с Ceph:
 - OSD (Object Storage Daemon) - процесс, который хранит данные на одном диске и обрабатывает
  запросы чтения/записи от клиентов.
 - Пул (Pool) - контейнер для данных, имеющих одну и ту же схему избыточности и правила распределения по OSD.
 - PG (Placement Group) - группа объектов, хранимых на одном и том же наборе реплик (OSD).
  Несколько PG могут храниться на одном и том же наборе реплик, но объекты одной PG
  в норме не хранятся на разных наборах OSD.
 - Монитор - демон, хранящий состояние кластера.
 - Домен отказа (Failure Domain) - группа OSD, которым вы разрешаете "упасть" всем вместе.
  Иными словами, это группа OSD, в которые СХД не помещает разные копии одного и того же
  блока данных. Например, если домен отказа - сервер, то на двух дисках одного сервера
  никогда не окажется 2 и более копий одного и того же блока данных, а значит, даже
  если в этом сервере откажут все диски, это будет равносильно потере только 1 копии
  любого блока данных.
 - Дерево распределения (Placement Tree / CRUSH Tree) - иерархическая группировка OSD
  в узлы, которые далее можно использовать как домены отказа. То есть, диск (OSD) входит в
  сервер, сервер входит в стойку, стойка входит в ряд, ряд в датацентр и т.п.
 Чем Vitastor отличается от Ceph:
 - Vitastor в первую очередь сфокусирован на SSD. Также Vitastor, вероятно, должен неплохо работать
  с комбинацией SSD и HDD через bcache, а в будущем, возможно, будут добавлены и нативные способы
  оптимизации под SSD+HDD. Однако хранилище на основе одних лишь жёстких дисков, вообще без SSD,
  не в приоритете, поэтому оптимизации под этот кейс могут вообще не состояться.
 - OSD Vitastor однопоточный и всегда таким останется, так как это самый оптимальный способ работы.
  Если вам не хватает 1 ядра на 1 диск, просто делите диск на разделы и запускайте на нём несколько OSD.
  Но, скорее всего, вам хватит и 1 ядра - Vitastor не так прожорлив к ресурсам CPU, как Ceph.
 - Журнал и метаданные всегда размещаются в памяти, благодаря чему никогда не тратится лишнее время
  на чтение метаданных с диска. Размер метаданных линейно зависит от размера диска и блока данных,
  который задаётся в конфигурации кластера и по умолчанию составляет 128 КБ. С блоком 128 КБ метаданные
  занимают примерно 512 МБ памяти на 1 ТБ дискового пространства (и это всё равно меньше, чем нужно Ceph-у).
  Журнал вообще не должен быть большим, например, тесты производительности в данном документе проводились
  с журналом размером всего 16 МБ. Большой журнал, вероятно, даже вреден, т.к. "грязные" записи (записи,
  не сброшенные из журнала) тоже занимают память и могут немного замедлять работу.
 - В Vitastor нет внутреннего copy-on-write. Я считаю, что реализация CoW-хранилища гораздо сложнее,
  поэтому сложнее добиться устойчиво хороших результатов. Возможно, в один прекрасный день
  я придумаю красивый алгоритм для CoW-хранилища, но пока нет - внутреннего CoW в Vitastor не будет.
  Всё это не относится к "внешнему" CoW (снапшотам и клонам).
 - Базовый слой Vitastor - простое блочное хранилище с блоками фиксированного размера, а не сложное
  объектное хранилище с расширенными возможностями, как в Ceph (RADOS).
 - В Vitastor есть режим "ленивых fsync", в котором OSD группирует запросы записи перед сбросом их
  на диск, что позволяет получить лучшую производительность с дешёвыми настольными SSD без конденсаторов
  ("Advanced Power Loss Protection" / "Capacitor-Based Power Loss Protection").
  Тем не менее, такой режим всё равно медленнее использования нормальных серверных SSD и мгновенного
  fsync, так как приводит к дополнительным операциям передачи данных по сети, поэтому рекомендуется
  всё-таки использовать хорошие серверные диски, тем более, стоят они почти так же, как десктопные.
 - PG эфемерны. Это означает, что они не хранятся на дисках и существуют только в памяти работающих OSD.
 - Процессы восстановления оперируют отдельными объектами, а не целыми PG.
 - PGLOG-ов нет.
 - "Мониторы" не хранят данные. Конфигурация и состояние кластера хранятся в etcd в простых человекочитаемых
  JSON-структурах. Мониторы Vitastor только следят за состоянием кластера и управляют перемещением данных.
  В этом смысле монитор Vitastor не является критичным компонентом системы и больше похож на Ceph-овский
  менеджер (MGR). Монитор Vitastor написан на node.js.
 - Распределение PG не основано на консистентных хешах. Вместо этого все маппинги PG хранятся прямо в etcd
  (ибо нет никакой проблемы сохранить несколько сотен-тысяч записей в памяти, а не считать каждый раз хеши).
  Перераспределение PG по OSD выполняется через математическую оптимизацию,
  а конкретно, сведение задачи к ЛП (задаче линейного программирования) и решение оной с помощью утилиты
  lp_solve. Такой подход позволяет обычно выравнивать распределение места почти идеально - равномерность
  обычно составляет 96-99%, в отличие от Ceph, где на голом CRUSH-е без балансировщика обычно выходит 80-90%.
  Также это позволяет минимизировать объём перемещения данных и случайность связей между OSD, а также менять
  распределение вручную, не боясь сломать логику перебалансировки. В таком подходе есть и потенциальный
  недостаток - есть предположение, что в очень большом кластере он может сломаться - однако вплоть до
  нескольких сотен OSD подход точно работает нормально. Ну и, собственно, при необходимости легко
  реализовать и консистентные хеши.
 - Отдельный слой, подобный слою "CRUSH-правил", отсутствует. Вы настраиваете схемы отказоустойчивости,
  домены отказа и правила выбора OSD напрямую в конфигурации пулов.
 ## Понимание сути производительности систем хранения
 Вкратце: для быстрой хранилки задержки важнее, чем пиковые iops-ы.
 Лучшая возможная задержка достигается при тестировании в 1 поток с глубиной очереди 1,
 что приблизительно означает минимально нагруженное состояние кластера. В данном случае
 IOPS = 1/задержка. Ни числом серверов, ни дисков, ни серверных процессов/потоков
 задержка не масштабируется... Она зависит только от того, насколько быстро один
 серверный процесс (и клиент) обрабатывают одну операцию.
 Почему задержки важны? Потому, что некоторые приложения *не могут* использовать глубину
 очереди больше 1, ибо их задача не параллелизуется. Важный пример - это все СУБД
 с поддержкой консистентности (ACID), потому что все они обеспечивают её через
 журналирование, а журналы пишутся последовательно и с fsync() после каждой операции.
 fsync, кстати - это ещё одна очень важная вещь, про которую почти всегда забывают в тестах.
 Смысл в том, что все современные диски имеют кэши/буферы записи и не гарантируют, что
 данные реально физически записываются на носитель до того, как вы делаете fsync(),
 который транслируется в команду сброса кэша операционной системой.
 Дешёвые SSD для настольных ПК и ноутбуков очень быстрые без fsync - NVMe диски, например,
 могут обработать порядка 80000 операций записи в секунду с глубиной очереди 1 без fsync.
 Однако с fsync, когда они реально вынуждены писать каждый блок данных во флеш-память,
 они выжимают лишь 1000-2000 операций записи в секунду (число практически постоянное
 для всех моделей SSD).
 Серверные SSD часто имеют суперконденсаторы, работающие как встроенный источник
 бесперебойного питания и дающие дискам успеть сбросить их DRAM-кэш в постоянную
 флеш-память при отключении питания. Благодаря этому диски с чистой совестью
 *игнорируют fsync*, так как точно знают, что данные из кэша доедут до постоянной
 памяти.
 Все наиболее известные программные СХД, например, Ceph и внутренние СХД, используемые
 такими облачными провайдерами, как Amazon, Google, Яндекс, медленные в смысле задержки.
 В лучшем случае они дают задержки от 0.3мс на чтение и 0.6мс на запись 4 КБ блоками
 даже при условии использования наилучшего возможного железа.
 И это в эпоху SSD, когда вы можете пойти на рынок и купить там SSD, задержка которого
 на чтение будет 0.1мс, а на запись - 0.04мс, за 100$ или даже дешевле.
 Когда мне нужно быстро протестировать производительность дисковой подсистемы, я
 использую следующие 6 команд, с небольшими вариациями:
 - Линейная запись:
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4M -iodepth=32 -rw=write -runtime=60 -filename=/dev/sdX`
 - Линейное чтение:
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4M -iodepth=32 -rw=read -runtime=60 -filename=/dev/sdX`
 - Запись в 1 поток (T1Q1):
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=1 -fsync=1 -rw=randwrite -runtime=60 -filename=/dev/sdX`
 - Чтение в 1 поток (T1Q1):
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=1 -rw=randread -runtime=60 -filename=/dev/sdX`
 - Параллельная запись (numjobs используется, когда 1 ядро CPU не может насытить диск):
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=128 [-numjobs=4 -group_reporting] -rw=randwrite -runtime=60 -filename=/dev/sdX`
 - Параллельное чтение (numjobs - аналогично):
  `fio -ioengine=libaio -direct=1 -invalidate=1 -name=test -bs=4k -iodepth=128 [-numjobs=4 -group_reporting] -rw=randread -runtime=60 -filename=/dev/sdX`
 ## Теоретическая максимальная производительность Vitastor
 При использовании репликации:
 - Задержка чтения в 1 поток (T1Q1): 1 сетевой RTT + 1 чтение с диска.
 - Запись+fsync в 1 поток:
  - С мгновенным сбросом: 2 RTT + 1 запись.
  - С отложенным ("ленивым") сбросом: 4 RTT + 1 запись + 1 fsync.
 - Параллельное чтение: сумма IOPS всех дисков либо производительность сети, если в сеть упрётся раньше.
 - Параллельная запись: сумма IOPS всех дисков / число реплик / WA либо производительность сети, если в сеть упрётся раньше.
 При использовании кодов коррекции ошибок (EC):
 - Задержка чтения в 1 поток (T1Q1): 1.5 RTT + 1 чтение.
 - Запись+fsync в 1 поток:
  - С мгновенным сбросом: 3.5 RTT + 1 чтение + 2 записи.
  - С отложенным ("ленивым") сбросом: 5.5 RTT + 1 чтение + 2 записи + 2 fsync.
 - Под 0.5 на самом деле подразумевается (k-1)/k, где k - число дисков данных,
  что означает, что дополнительное обращение по сети не нужно, когда операция
  чтения обслуживается локально.
 - Параллельное чтение: сумма IOPS всех дисков либо производительность сети, если в сеть упрётся раньше.
 - Параллельная запись: сумма IOPS всех дисков / общее число дисков данных и чётности / WA либо производительность сети, если в сеть упрётся раньше.
  Примечание: IOPS дисков в данном случае надо брать в смешанном режиме чтения/записи в пропорции, аналогичной формулам выше.
 WA (мультипликатор записи) для 4 КБ блоков в Vitastor обычно составляет 3-5:
 1. Запись метаданных в журнал
 2. Запись блока данных в журнал
 3. Запись метаданных в БД
 4. Ещё одна запись метаданных в журнал при использовании EC
 5. Запись блока данных на диск данных
 Если вы найдёте SSD, хорошо работающий с 512-байтными блоками данных (Optane?),
 то 1, 3 и 4 можно снизить до 512 байт (1/8 от размера данных) и получить WA всего 2.375.
 Кроме того, WA снижается при использовании отложенного/ленивого сброса при параллельной
 нагрузке, т.к. блоки журнала записываются на диск только когда они заполняются или явным
 образом запрашивается fsync.
 ## Пример сравнения с Ceph
 Железо - 4 сервера, в каждом:
 - 6x SATA SSD Intel D3-4510 3.84 TB
 - 2x Xeon Gold 6242 (16 cores @ 2.8 GHz)
 - 384 GB RAM
 - 1x 25 GbE сетевая карта (Mellanox ConnectX-4 LX), подключённая к свитчу Juniper QFX5200
 Экономия энергии CPU отключена. В тестах и Vitastor, и Ceph развёрнуто по 2 OSD на 1 SSD.
 Все результаты ниже относятся к случайной нагрузке 4 КБ блоками (если явно не указано обратное).
 Производительность голых дисков:
 - T1Q1 запись ~27000 iops (задержка ~0.037ms)
 - T1Q1 чтение ~9800 iops (задержка ~0.101ms)
 - T1Q32 запись ~60000 iops
 - T1Q32 чтение ~81700 iops
 Ceph 15.2.4 (Bluestore):
 - T1Q1 запись ~1000 iops (задержка ~1ms)
 - T1Q1 чтение ~1750 iops (задержка ~0.57ms)
 - T8Q64 запись ~100000 iops, потребление CPU процессами OSD около 40 ядер на каждом сервере
 - T8Q64 чтение ~480000 iops, потребление CPU процессами OSD около 40 ядер на каждом сервере
 Тесты в 8 потоков проводились на 8 400GB RBD образах со всех хостов (с каждого хоста запускалось 2 процесса fio).
 Это нужно потому, что в Ceph несколько RBD-клиентов, пишущих в 1 образ, очень сильно замедляются.
 Настройки RocksDB и Bluestore в Ceph не менялись, единственным изменением было отключение cephx_sign_messages.
 На самом деле, результаты теста не такие уж и плохие для Ceph (могло быть хуже).
 Собственно говоря, эти серверы как раз хорошо сбалансированы для Ceph - 6 SATA SSD как раз
 утилизируют 25-гигабитную сеть, а без 2 мощных процессоров Ceph-у бы не хватило ядер,
 чтобы выдать пристойный результат. Собственно, что и показывает жор 40 ядер в процессе
 параллельного теста.
 Vitastor:
 - T1Q1 запись: 7087 iops (задержка 0.14ms)
 - T1Q1 чтение: 6838 iops (задержка 0.145ms)
 - T2Q64 запись: 162000 iops, потребление CPU - 3 ядра на каждом сервере
 - T8Q64 чтение: 895000 iops, потребление CPU - 4 ядра на каждом сервере
 - Линейная запись (4M T1Q32): 2800 МБ/с
 - Линейное чтение (4M T1Q32): 1500 МБ/с
 Тест на чтение в 8 потоков проводился на 1 большом образе (3.2 ТБ) со всех хостов (опять же, по 2 fio с каждого).
 В Vitastor никакой разницы между 1 образом и 8-ю нет. Естественно, примерно 1/4 запросов чтения
 в такой конфигурации, как и в тестах Ceph выше, обслуживалась с локальной машины. Если проводить
 тест так, чтобы все операции всегда обращались к первичным OSD по сети - тест сильнее упирался
 в сеть и результат составлял примерно 689000 iops.
 Настройки Vitastor: `--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`.
 ### EC/XOR 2+1
 Vitastor:
 - T1Q1 запись: 2808 iops (задержка ~0.355ms)
 - T1Q1 чтение: 6190 iops (задержка ~0.16ms)
 - T2Q64 запись: 85500 iops, потребление CPU - 3.4 ядра на каждом сервере
 - T8Q64 чтение: 812000 iops, потребление CPU - 4.7 ядра на каждом сервере
 - Линейная запись (4M T1Q32): 3200 МБ/с
 - Линейное чтение (4M T1Q32): 1800 МБ/с
 Ceph:
 - T1Q1 запись: 730 iops (задержка ~1.37ms latency)
 - T1Q1 чтение: 1500 iops с холодным кэшем метаданных (задержка ~0.66ms), 2300 iops через 2 минуты прогрева (задержка ~0.435ms)
 - T4Q128 запись (4 RBD images): 45300 iops, потребление CPU - 30 ядер на каждом сервере
 - T8Q64 чтение (4 RBD images): 278600 iops, потребление CPU - 40 ядер на каждом сервере
 - Линейная запись (4M T1Q32): 1950 МБ/с в пустой образ, 2500 МБ/с в заполненный образ
 - Линейное чтение (4M T1Q32): 2400 МБ/с
 ### NBD
 NBD расшифровывается как "сетевое блочное устройство", но на самом деле оно также
 работает просто как аналог FUSE для блочных устройств, то есть, представляет собой
 "блочное устройство в пространстве пользователя".
 NBD - на данный момент единственный способ монтировать Vitastor ядром Linux.
 NBD немного снижает производительность, так как приводит к дополнительным копированиям
 данных между ядром и пространством пользователя. Тем не менее, способ достаточно оптимален,
 а производительность случайного доступа вообще затрагивается слабо.
 Vitastor с однопоточной NBD прокси на том же стенде:
 - T1Q1 запись: 6000 iops (задержка 0.166ms)
 - T1Q1 чтение: 5518 iops (задержка 0.18ms)
 - T1Q128 запись: 94400 iops
 - T1Q128 чтение: 103000 iops
 - Линейная запись (4M T1Q128): 1266 МБ/с (в сравнении с 2800 МБ/с через fio)
 - Линейное чтение (4M T1Q128): 975 МБ/с (в сравнении с 1500 МБ/с через fio)
 ## Установка
 ### Debian
 - Добавьте ключ репозитория Vitastor:
  `wget -q -O - https://vitastor.io/debian/pubkey | sudo apt-key add -`
 - Добавьте репозиторий Vitastor в /etc/apt/sources.list:
  - Debian 11 (Bullseye/Sid): `deb https://vitastor.io/debian bullseye main`
  - Debian 10 (Buster): `deb https://vitastor.io/debian buster main`
 - Для Debian 10 (Buster) также включите репозиторий backports:
  `deb http://deb.debian.org/debian buster-backports main`
 - Установите пакеты: `apt update; apt install vitastor lp-solve etcd linux-image-amd64 qemu`
 ### CentOS
 - Добавьте в систему репозиторий Vitastor:
  - CentOS 7: `yum install https://vitastor.io/rpms/centos/7/vitastor-release-1.0-1.el7.noarch.rpm`
  - CentOS 8: `dnf install https://vitastor.io/rpms/centos/8/vitastor-release-1.0-1.el8.noarch.rpm`
 - Включите EPEL: `yum/dnf install epel-release`
 - Включите дополнительные репозитории CentOS:
  - CentOS 7: `yum install centos-release-scl`
  - CentOS 8: `dnf install centos-release-advanced-virtualization`
 - Включите elrepo-kernel:
  - CentOS 7: `yum install https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm`
  - CentOS 8: `dnf install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm`
 - Установите пакеты: `yum/dnf install vitastor lpsolve etcd kernel-ml qemu-kvm`
 ### Установка из исходников
 - Установите ядро 5.4 или более новое, для поддержки io_uring. Желательно 5.8 или даже новее,
  так как в 5.4 есть как минимум 1 известный баг, ведущий к зависанию с io_uring и контроллером HP SmartArray.
 - Установите liburing 0.4 или более новый и его заголовки.
 - Установите lp_solve.
 - Установите etcd, версии не ниже 3.4.15. Более ранние версии работать не будут из-за различных багов,
  например [#12402](https://github.com/etcd-io/etcd/pull/12402). Также вы можете взять версию 3.4.13 с
  этим конкретным исправлением из ветки release-3.4 репозитория https://github.com/vitalif/etcd/.
 - Установите node.js 10 или новее.
 - Установите gcc и g++ 8.x или новее.
 - Склонируйте данный репозиторий с подмодулями: `git clone https://yourcmc.ru/git/vitalif/vitastor/`.
 - Желательно пересобрать QEMU с патчем, который делает необязательным запуск через LD_PRELOAD.
  См `patches/qemu-*.*-vitastor.patch` - выберите версию, наиболее близкую вашей версии QEMU.
 - Установите QEMU 3.0 или новее, возьмите исходные коды установленного пакета, начните его пересборку,
  через некоторое время остановите её и скопируйте следующие заголовки:
   - `<qemu>/include` &rarr; `<vitastor>/qemu/include`
   - Debian:
      * Берите qemu из основного репозитория
      * `<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:
      * Берите qemu из репозитория Advanced-Virtualization. Чтобы включить его, запустите
        `yum install centos-release-advanced-virtualization.noarch` и далее `yum install qemu`
      * `<qemu>/config-host.h` &rarr; `<vitastor>/qemu/b/qemu/config-host.h`
      * Для QEMU 3.0+: `<qemu>/qapi` &rarr; `<vitastor>/qemu/b/qemu/qapi`
      * Для QEMU 2.0+: `<qemu>/qapi-types.h` &rarr; `<vitastor>/qemu/b/qemu/qapi-types.h`
   - `config-host.h` и `qapi` нужны, т.к. в них содержатся автогенерируемые заголовки
 - Установите fio 3.7 или новее, возьмите исходники пакета и сделайте на них симлинк с `<vitastor>/fio`.
 - Соберите и установите Vitastor командой `mkdir build && cd build && cmake .. && make -j8 && make install`.
  Обратите внимание на переменную cmake `QEMU_PLUGINDIR` - под RHEL её нужно установить равной `qemu-kvm`.
 ## Запуск
 Внимание: процедура пока что достаточно нетривиальная, задавать конфигурацию и смещения
 на диске нужно почти вручную. Это будет исправлено в ближайшем будущем.
 - Желательны SATA SSD или NVMe диски с конденсаторами (серверные SSD). Можно использовать и
  десктопные SSD, включив режим отложенного fsync, но производительность однопоточной записи
  в этом случае пострадает.
 - Быстрая сеть, минимум 10 гбит/с
 - Для наилучшей производительности нужно отключить энергосбережение CPU: `cpupower idle-set -D 0 && cpupower frequency-set -g performance`.
 - На хостах мониторов:
  - Пропишите нужные вам значения в файле `/usr/lib/vitastor/mon/make-units.sh`
  - Создайте юниты systemd для etcd и мониторов: `/usr/lib/vitastor/mon/make-units.sh`
 - Пропишите etcd_address и osd_network в `/etc/vitastor/vitastor.conf`. Например:
  ```
  {
    "etcd_address": ["10.200.1.10:2379","10.200.1.11:2379","10.200.1.12:2379"],
    "osd_network": "10.200.1.0/24"
  }
  ```
 - Создайте юниты systemd для OSD: `/usr/lib/vitastor/make-osd.sh /dev/disk/by-partuuid/XXX [/dev/disk/by-partuuid/YYY ...]`
 - Вы можете менять параметры OSD в юнитах systemd или в `vitastor.conf`. Смысл некоторых параметров:
  - `disable_data_fsync 1` - отключает fsync, используется с SSD с конденсаторами.
  - `immediate_commit all` - используется с SSD с конденсаторами.
    Внимание: если установлено, также нужно установить его в то же значение в etcd в /vitastor/config/global
  - `disable_device_lock 1` - отключает блокировку файла устройства, нужно, только если вы запускаете
    несколько OSD на одном блочном устройстве.
  - `flusher_count 256` - "flusher" - микропоток, удаляющий старые данные из журнала.
    Не волнуйтесь об этой настройке, 256 теперь достаточно практически всегда.
  - `disk_alignment`, `journal_block_size`, `meta_block_size` следует установить равными размеру
    внутреннего блока SSD. Это почти всегда 4096.
  - `journal_no_same_sector_overwrites true` запрещает перезапись одного и того же сектора журнала подряд
    много раз в процессе записи. Большинство (99%) SSD не нуждаются в данной опции. Однако выяснилось, что
    диски, используемые на одном из тестовых стендов - Intel D3-S4510 - очень сильно не любят такую
    перезапись, и для них была добавлена эта опция. Когда данный режим включён, также нужно поднимать
    значение `journal_sector_buffer_count`, так как иначе Vitastor не хватит буферов для записи в журнал.
 - Запустите все etcd: `systemctl start etcd`
 - Создайте глобальную конфигурацию в etcd: `etcdctl --endpoints=... put /vitastor/config/global '{"immediate_commit":"all"}'`
  (если все ваши диски - серверные с конденсаторами).
 - Создайте пулы: `etcdctl --endpoints=... put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":256,"failure_domain":"host"}}'`.
  Для jerasure EC-пулов конфигурация должна выглядеть так: `2:{"name":"ecpool","scheme":"jerasure","pg_size":4,"parity_chunks":2,"pg_minsize":2,"pg_count":256,"failure_domain":"host"}`.
 - Запустите все OSD: `systemctl start vitastor.target`
 - Ваш кластер должен быть готов - один из мониторов должен уже сконфигурировать PG, а OSD должны запустить их.
 - Вы можете проверить состояние PG прямо в etcd: `etcdctl --endpoints=... get --prefix /vitastor/pg/state`. Все PG должны быть 'active'.
 ### Задать имя образу
 ```
 etcdctl --endpoints=<etcd> put /vitastor/config/inode/<pool>/<inode> '{"name":"<name>","size":<size>[,"parent_id":<parent_inode_number>][,"readonly":true]}'
 ```
 Например:
 ```
 etcdctl --endpoints=http://10.115.0.10:2379/v3 put /vitastor/config/inode/1/1 '{"name":"testimg","size":2147483648}'
 ```
 Если вы зададите parent_id, то образ станет CoW-клоном, т.е. все новые запросы записи пойдут в новый инод, а запросы
 чтения будут проверять сначала его, а потом родительские слои по цепочке вверх. Чтобы случайно не перезаписать данные
 в родительском слое, вы можете переключить его в режим "только чтение", добавив флаг `"readonly":true` в его запись
 метаданных. В таком случае родительский образ становится просто снапшотом.
 Таким образом, для создания снапшота вам нужно просто переименовать предыдущий inode (например, из testimg в testimg@0),
 сделать его readonly и создать новый слой с исходным именем образа (testimg), ссылающийся на только что переименованный
 в качестве родительского.
 ### Запуск тестов с fio
 Пример команды для запуска тестов:
 ```
 fio -thread -ioengine=libfio_vitastor.so -name=test -bs=4M -direct=1 -iodepth=16 -rw=write -etcd=10.115.0.10:2379/v3 -image=testimg
 ```
 Если вы не хотите обращаться к образу по имени, вместо `-image=testimg` можно указать номер пула, номер инода и размер:
 `-pool=1 -inode=1 -size=400G`.
 ### Загрузить образ диска ВМ в/из Vitastor
 Используйте qemu-img и строку `vitastor:etcd_host=<HOST>:image=<IMAGE>` в качестве имени файла диска. Например:
 ```
 qemu-img convert -f qcow2 debian10.qcow2 -p -O raw 'vitastor:etcd_host=10.115.0.10\:2379/v3:image=testimg'
 ```
 Обратите внимание, что если вы используете немодифицированный QEMU, потребуется установить переменную окружения
 `LD_PRELOAD=/usr/lib/x86_64-linux-gnu/qemu/block-vitastor.so`.
 Если вы не хотите обращаться к образу по имени, вместо `:image=<IMAGE>` можно указать номер пула, номер инода и размер:
 `:pool=<POOL>:inode=<INODE>:size=<SIZE>`.
 ### Запустить ВМ
 Для запуска QEMU используйте опцию `-drive file=vitastor:etcd_host=<HOST>:image=<IMAGE>` (аналогично qemu-img)
 и физический размер блока 4 KB.
 Например:
 ```
 qemu-system-x86_64 -enable-kvm -m 1024
  -drive 'file=vitastor:etcd_host=10.115.0.10\:2379/v3:image=testimg',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
 ```
 Обращение по номерам (`:pool=<POOL>:inode=<INODE>:size=<SIZE>` вместо `:image=<IMAGE>`) работает аналогично qemu-img.
 ### Удалить образ
 Используйте утилиту vitastor-cli rm-data. Например:
 ```
 vitastor-cli rm-data --etcd_address 10.115.0.10:2379/v3 --pool 1 --inode 1 --parallel_osds 16 --iodepth 32
 ```
 ### NBD
 Чтобы создать локальное блочное устройство, используйте NBD. Например:
 ```
 vitastor-nbd map --etcd_address 10.115.0.10:2379/v3 --image testimg
 ```
 Команда напечатает название устройства вида /dev/nbd0, которое потом можно будет форматировать
 и использовать как обычное блочное устройство.
 Для обращения по номеру инода, аналогично другим командам, можно использовать опции
 `--pool <POOL> --inode <INODE> --size <SIZE>` вместо `--image testimg`.
 ### Kubernetes
 У Vitastor есть CSI-плагин для Kubernetes, поддерживающий RWO-тома.
 Для установки возьмите манифесты из директории [csi/deploy/](csi/deploy/), поместите
 вашу конфигурацию подключения к Vitastor в [csi/deploy/001-csi-config-map.yaml](001-csi-config-map.yaml),
 настройте StorageClass в [csi/deploy/009-storage-class.yaml](009-storage-class.yaml)
 и примените все `NNN-*.yaml` к вашей инсталляции Kubernetes.
 ```
 for i in ./???-*.yaml; do kubectl apply -f $i; done
 ```
 После этого вы сможете создавать PersistentVolume. Пример смотрите в файле [csi/deploy/example-pvc.yaml](csi/deploy/example-pvc.yaml).
 ### OpenStack
 Чтобы подключить Vitastor к OpenStack:
 - Установите пакеты vitastor-client, libvirt и QEMU из DEB или RPM репозитория Vitastor
 - Примените патч `patches/nova-21.diff` или `patches/nova-23.diff` к вашей инсталляции Nova.
  nova-21.diff подходит для Nova 21-22, nova-23.diff подходит для Nova 23-24.
 - Скопируйте `patches/cinder-vitastor.py` в инсталляцию Cinder как `cinder/volume/drivers/vitastor.py`
 - Создайте тип томов в cinder.conf (см. ниже)
 - Обязательно заблокируйте доступ от виртуальных машин к сети Vitastor (OSD и etcd), т.к. Vitastor (пока) не поддерживает аутентификацию
 - Перезапустите Cinder и Nova
 Пример конфигурации Cinder:
 ```
 [DEFAULT]
 enabled_backends = lvmdriver-1, vitastor-testcluster
 # ...
 [vitastor-testcluster]
 volume_driver = cinder.volume.drivers.vitastor.VitastorDriver
 volume_backend_name = vitastor-testcluster
 image_volume_cache_enabled = True
 volume_clear = none
 vitastor_etcd_address = 192.168.7.2:2379
 vitastor_etcd_prefix =
 vitastor_config_path = /etc/vitastor/vitastor.conf
 vitastor_pool_id = 1
 image_upload_use_cinder_backend = True
 ```
 Чтобы помещать в Vitastor Glance-образы, нужно использовать
 [https://docs.openstack.org/cinder/pike/admin/blockstorage-volume-backed-image.html](образы на основе томов Cinder),
 однако, поддержка этой функции ещё не проверялась.
 ### Proxmox
 Чтобы подключить Vitastor к Proxmox Virtual Environment (поддерживаются версии 6.4 и 7.1):
 - Добавьте соответствующий Debian-репозиторий Vitastor в sources.list на хостах Proxmox
  (buster для 6.4, bullseye для 7.1)
 - Установите пакеты vitastor-client, pve-qemu-kvm, pve-storage-vitastor (* или см. сноску) из репозитория Vitastor
 - Определите тип хранилища в `/etc/pve/storage.cfg` (см. ниже)
 - Обязательно заблокируйте доступ от виртуальных машин к сети Vitastor (OSD и etcd), т.к. Vitastor (пока) не поддерживает аутентификацию
 - Перезапустите демон Proxmox: `systemctl restart pvedaemon`
 Пример `/etc/pve/storage.cfg` (единственная обязательная опция - vitastor_pool, все остальные
 перечислены внизу для понимания значений по умолчанию):
 ```
 vitastor: vitastor
    # Пул, в который будут помещаться образы дисков
    vitastor_pool testpool
    # Путь к файлу конфигурации
    vitastor_config_path /etc/vitastor/vitastor.conf
    # Адрес(а) etcd, нужны, только если не указаны в vitastor.conf
    vitastor_etcd_address 192.168.7.2:2379/v3
    # Префикс ключей метаданных в etcd
    vitastor_etcd_prefix /vitastor
    # Префикс имён образов
    vitastor_prefix pve/
    # Монтировать образы через NBD прокси, через ядро (нужно только для контейнеров)
    vitastor_nbd 0
 ```
 \* Примечание: вместо установки пакета pve-storage-vitastor вы можете вручную скопировать файл
 [patches/PVE_VitastorPlugin.pm](patches/PVE_VitastorPlugin.pm) на хосты Proxmox как
 `/usr/share/perl5/PVE/Storage/Custom/VitastorPlugin.pm`.
 ## Известные проблемы
 - Запросы удаления объектов могут в данный момент приводить к "неполным" объектам в EC-пулах,
  если в процессе удаления произойдут отказы OSD или серверов, потому что правильная обработка
  запросов удаления в кластере должна быть "трёхфазной", а это пока не реализовано. Если вы
  столкнётесь с такой ситуацией, просто повторите запрос удаления.
 ## Принципы реализации
 - Я люблю архитектурно простые решения. Vitastor проектируется именно так и я намерен
  и далее следовать данному принципу.
 - Если вы пришли сюда за идеальным кодом на C++, вы, вероятно, не по адресу. "Общепринятые"
  практики написания C++ кода меня не очень волнуют, так как зачастую, опять-таки, ведут к
  излишним усложнениям и код получается красивый... но медленный.
 - По той же причине в коде иногда можно встретить велосипеды типа собственного упрощённого
  HTTP-клиента для работы с etcd. Зато эти велосипеды маленькие и компактные и не требуют
  использования десятка внешних библиотек.
 - node.js для монитора - не случайный выбор. Он очень быстрый, имеет встроенную событийную
  машину, приятный нейтральный C-подобный язык программирования и развитую инфраструктуру.
 ## Автор и лицензия
 Автор: Виталий Филиппов (vitalif [at] yourcmc.ru), 2019+
 Заходите в Telegram-чат Vitastor: https://t.me/vitastor
 Лицензия: VNPL 1.1 на серверный код и двойная VNPL 1.1 + GPL 2.0+ на клиентский.
 VNPL - "сетевой копилефт", собственная свободная копилефт-лицензия
 Vitastor Network Public License 1.1, основанная на GNU GPL 3.0 с дополнительным
 условием "Сетевого взаимодействия", требующим распространять все программы,
 специально разработанные для использования вместе с Vitastor и взаимодействующие
 с ним по сети, под лицензией VNPL или под любой другой свободной лицензией.
 Идея VNPL - расширение действия копилефта не только на модули, явным образом
 связываемые с кодом Vitastor, но также на модули, оформленные в виде микросервисов
 и взаимодействующие с ним по сети.
 Таким образом, если вы хотите построить на основе Vitastor сервис, содержаший
 компоненты с закрытым кодом, взаимодействующие с Vitastor, вам нужна коммерческая
 лицензия от автора 😀.
 На Windows и любое другое ПО, не разработанное *специально* для использования
 вместе с Vitastor, никакие ограничения не накладываются.
 Клиентские библиотеки распространяются на условиях двойной лицензии VNPL 1.0
 и также на условиях GNU GPL 2.0 или более поздней версии. Так сделано в целях
 совместимости с таким ПО, как QEMU и fio.
 Вы можете найти полный текст VNPL 1.1 в файле [VNPL-1.1.txt](VNPL-1.1.txt),
 а GPL 2.0 в файле [GPL-2.0.txt](GPL-2.0.txt).
--- a/README.md
+++ b/README.md
@ -1,608 +0,0 @@
 ## Vitastor
 [Читать на русском](README-ru.md)
 ## 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
 - Multiple redundancy schemes: Replication, XOR n+1, Reed-Solomon erasure codes
  based on jerasure library with any number of data and parity drives in a group
 - 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, OSD selection by tags (device classes) and placement root
  - 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
 - Inode removal tool (vitastor-cli rm-data)
 - Packaging for Debian and CentOS
 - Per-inode I/O and space usage statistics
 - Inode metadata storage in etcd
 - Snapshots and copy-on-write image clones
 - Write throttling to smooth random write workloads in SSD+HDD configurations
 - RDMA/RoCEv2 support via libibverbs
 - CSI plugin for Kubernetes
 - Basic OpenStack support: Cinder driver, Nova and libvirt patches
 - Snapshot merge tool (vitastor-cli {snap-rm,flatten,merge})
 - Image management CLI (vitastor-cli {ls,create,modify})
 - Proxmox storage plugin
 ## Roadmap
 - Snapshot deletion (layer merge) support
 - Better OSD creation and auto-start tools
 - Other administrative tools
 - Plugins for OpenNebula, Proxmox and other cloud systems
 - iSCSI proxy
 - Faster failover
 - Scrubbing without checksums (verification of replicas)
 - Checksums
 - Tiered storage
 - NVDIMM support
 - Web GUI
 - 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 (T1Q1, 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 (T1Q1):
  `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 and random access (unless indicated otherwise).
 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
 - Linear write (4M T1Q32): 2800 MB/s
 - Linear read (4M T1Q32): 1500 MB/s
 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`.
 ### EC/XOR 2+1
 Vitastor:
 - T1Q1 write: 2808 iops (~0.355ms latency)
 - T1Q1 read: 6190 iops (~0.16ms latency)
 - T2Q64 write: 85500 iops, total CPU usage by OSDs about 3.4 virtual cores on each node
 - T8Q64 read: 812000 iops, total CPU usage by OSDs about 4.7 virtual cores on each node
 - Linear write (4M T1Q32): 3200 MB/s
 - Linear read (4M T1Q32): 1800 MB/s
 Ceph:
 - T1Q1 write: 730 iops (~1.37ms latency)
 - T1Q1 read: 1500 iops with cold cache (~0.66ms latency), 2300 iops after 2 minute metadata cache warmup (~0.435ms latency)
 - T4Q128 write (4 RBD images): 45300 iops, total CPU usage by OSDs about 30 virtual cores on each node
 - T8Q64 read (4 RBD images): 278600 iops, total CPU usage by OSDs about 40 virtual cores on each node
 - Linear write (4M T1Q32): 1950 MB/s before preallocation, 2500 MB/s after preallocation
 - Linear read (4M T1Q32): 2400 MB/s
 ### 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 2800 MB/s via fio)
 - Linear read (4M T1Q128): 975 MB/s (compared to 1500 MB/s via fio)
 ## Installation
 ### Debian
 - Trust Vitastor package signing key:
  `wget -q -O - https://vitastor.io/debian/pubkey | sudo apt-key add -`
 - Add Vitastor package repository to your /etc/apt/sources.list:
  - Debian 11 (Bullseye/Sid): `deb https://vitastor.io/debian bullseye main`
  - Debian 10 (Buster): `deb https://vitastor.io/debian buster main`
 - For Debian 10 (Buster) also enable backports repository:
  `deb http://deb.debian.org/debian buster-backports main`
 - Install packages: `apt update; apt install vitastor lp-solve etcd linux-image-amd64 qemu`
 ### CentOS
 - Add Vitastor package repository:
  - CentOS 7: `yum install https://vitastor.io/rpms/centos/7/vitastor-release-1.0-1.el7.noarch.rpm`
  - CentOS 8: `dnf install https://vitastor.io/rpms/centos/8/vitastor-release-1.0-1.el8.noarch.rpm`
 - Enable EPEL: `yum/dnf install epel-release`
 - Enable additional CentOS repositories:
  - CentOS 7: `yum install centos-release-scl`
  - CentOS 8: `dnf install centos-release-advanced-virtualization`
 - Enable elrepo-kernel:
  - CentOS 7: `yum install https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm`
  - CentOS 8: `dnf install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm`
 - Install packages: `yum/dnf install vitastor lpsolve etcd kernel-ml qemu-kvm`
 ### Building from Source
 - Install Linux kernel 5.4 or newer, for io_uring support. 5.8 or later is highly recommended because
  there is at least one known io_uring hang with 5.4 and an HP SmartArray controller.
 - Install liburing 0.4 or newer and its headers.
 - Install lp_solve.
 - Install etcd, at least version 3.4.15. Earlier versions won't work because of various bugs,
  for example [#12402](https://github.com/etcd-io/etcd/pull/12402). You can also take 3.4.13
  with this specific fix from here: https://github.com/vitalif/etcd/, branch release-3.4.
 - Install node.js 10 or newer.
 - Install gcc and g++ 8.x or newer.
 - Clone https://yourcmc.ru/git/vitalif/vitastor/ with submodules.
 - Install QEMU 3.0+, 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`
      * For QEMU 3.0+: `<qemu>/qapi` &rarr; `<vitastor>/qemu/b/qemu/qapi`
      * For QEMU 2.0+: `<qemu>/qapi-types.h` &rarr; `<vitastor>/qemu/b/qemu/qapi-types.h`
   - `config-host.h` and `qapi` are required because they contain generated headers
 - You can also rebuild QEMU with a patch that makes LD_PRELOAD unnecessary to load vitastor driver.
  See `patches/qemu-*.*-vitastor.patch`.
 - Install fio 3.7 or later, get its source and symlink it into `<vitastor>/fio`.
 - Build & install Vitastor with `mkdir build && cd build && cmake .. && make -j8 && make install`.
  Pay attention to the `QEMU_PLUGINDIR` cmake option - it must be set to `qemu-kvm` on RHEL.
 ## 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`.
 - On the monitor hosts:
  - Edit variables at the top of `/usr/lib/vitastor/mon/make-units.sh` to desired values.
  - Create systemd units for the monitor and etcd: `/usr/lib/vitastor/mon/make-units.sh`
 - Put etcd_address and osd_network into `/etc/vitastor/vitastor.conf`. Example:
  ```
  {
    "etcd_address": ["10.200.1.10:2379","10.200.1.11:2379","10.200.1.12:2379"],
    "osd_network": "10.200.1.0/24"
  }
  ```
 - Create systemd units for your OSDs: `/usr/lib/vitastor/mon/make-osd.sh /dev/disk/by-partuuid/XXX [/dev/disk/by-partuuid/YYY ...]`
 - You can change OSD configuration in units or in `vitastor.conf`. Notable configuration variables:
  - `disable_data_fsync 1` - only safe with server-grade drives with capacitors.
  - `immediate_commit all` - use this if all your drives are server-grade.
    If all OSDs have it set to all then you should also put the same value in etcd into /vitastor/config/global
  - `disable_device_lock 1` - only required if you run multiple OSDs on one block device.
  - `flusher_count 256` - flusher is a micro-thread that removes old data from the journal.
    You don't have to worry about this parameter anymore, 256 is enough.
  - `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.
    Most (99%) SSDs don't need this option. But Intel D3-4510 does because it doesn't like when you
    overwrite the same sector twice in a short period of time. The setting forces Vitastor to never
    overwrite the same journal sector twice in a row which makes D3-4510 almost happy. Not totally
    happy, because overwrites of the same block can still happen in the metadata area... 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.
 - Create global configuration in etcd: `etcdctl --endpoints=... put /vitastor/config/global '{"immediate_commit":"all"}'`
  (if all your drives have capacitors).
 - Create pool configuration in etcd: `etcdctl --endpoints=... put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"replicated","pg_size":2,"pg_minsize":1,"pg_count":256,"failure_domain":"host"}}'`.
  For jerasure pools the configuration should look like the following: `2:{"name":"ecpool","scheme":"jerasure","pg_size":4,"parity_chunks":2,"pg_minsize":2,"pg_count":256,"failure_domain":"host"}`.
 - At this point, one of the monitors will configure PGs and OSDs will start them.
 - You can check PG states with `etcdctl --endpoints=... get --prefix /vitastor/pg/state`. All PGs should become 'active'.
 ### Name an image
 ```
 etcdctl --endpoints=<etcd> put /vitastor/config/inode/<pool>/<inode> '{"name":"<name>","size":<size>[,"parent_id":<parent_inode_number>][,"readonly":true]}'
 ```
 For example:
 ```
 etcdctl --endpoints=http://10.115.0.10:2379/v3 put /vitastor/config/inode/1/1 '{"name":"testimg","size":2147483648}'
 ```
 If you specify parent_id the image becomes a CoW clone. I.e. all writes go to the new inode and reads first check it
 and then upper layers. You can then make parent readonly by updating its entry with `"readonly":true` for safety and
 basically treat it as a snapshot.
 So to create a snapshot you basically rename the previous upper layer (for example from testimg to testimg@0), make it readonly
 and create a new top layer with the original name (testimg) and the previous one as a parent.
 ### Run fio benchmarks
 fio command example:
 ```
 fio -thread -ioengine=libfio_vitastor.so -name=test -bs=4M -direct=1 -iodepth=16 -rw=write -etcd=10.115.0.10:2379/v3 -image=testimg
 ```
 If you don't want to access your image by name, you can specify pool number, inode number and size
 (`-pool=1 -inode=1 -size=400G`) instead of the image name (`-image=testimg`).
 ### Upload VM image
 Use qemu-img and `vitastor:etcd_host=<HOST>:image=<IMAGE>` disk filename. For example:
 ```
 qemu-img convert -f qcow2 debian10.qcow2 -p -O raw 'vitastor:etcd_host=10.115.0.10\:2379/v3:image=testimg'
 ```
 Note that the command requires to be run with `LD_PRELOAD=/usr/lib/x86_64-linux-gnu/qemu/block-vitastor.so qemu-img ...`
 if you use unmodified QEMU.
 You can also specify `:pool=<POOL>:inode=<INODE>:size=<SIZE>` instead of `:image=<IMAGE>`
 if you don't want to use inode metadata.
 ### Start a VM
 Run QEMU with `-drive file=vitastor:etcd_host=<HOST>:image=<IMAGE>` and use 4 KB physical block size.
 For example:
 ```
 qemu-system-x86_64 -enable-kvm -m 1024
  -drive 'file=vitastor:etcd_host=10.115.0.10\:2379/v3:image=testimg',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
 ```
 You can also specify `:pool=<POOL>:inode=<INODE>:size=<SIZE>` instead of `:image=<IMAGE>`,
 just like in qemu-img.
 ### Remove inode
 Use vitastor-rm / vitastor-cli rm-data. For example:
 ```
 vitastor-cli rm-data --etcd_address 10.115.0.10:2379/v3 --pool 1 --inode 1 --parallel_osds 16 --iodepth 32
 ```
 ### NBD
 To create a local block device for a Vitastor image, use NBD. For example:
 ```
 vitastor-nbd map --etcd_address 10.115.0.10:2379/v3 --image testimg
 ```
 It will output the device name, like /dev/nbd0 which you can then format and mount as a normal block device.
 Again, you can use `--pool <POOL> --inode <INODE> --size <SIZE>` insteaf of `--image <IMAGE>` if you want.
 ### Kubernetes
 Vitastor has a CSI plugin for Kubernetes which supports RWO volumes.
 To deploy it, take manifests from [csi/deploy/](csi/deploy/) directory, put your
 Vitastor configuration in [csi/deploy/001-csi-config-map.yaml](001-csi-config-map.yaml),
 configure storage class in [csi/deploy/009-storage-class.yaml](009-storage-class.yaml)
 and apply all `NNN-*.yaml` manifests to your Kubernetes installation:
 ```
 for i in ./???-*.yaml; do kubectl apply -f $i; done
 ```
 After that you'll be able to create PersistentVolumes. See example in [csi/deploy/example-pvc.yaml](csi/deploy/example-pvc.yaml).
 ### OpenStack
 To enable Vitastor support in an OpenStack installation:
 - Install vitastor-client, patched QEMU and libvirt packages from Vitastor DEB or RPM repository
 - Use `patches/nova-21.diff` or `patches/nova-23.diff` to patch your Nova installation.
  Patch 21 fits Nova 21-22, patch 23 fits Nova 23-24.
 - Install `patches/cinder-vitastor.py` as `..../cinder/volume/drivers/vitastor.py`
 - Define a volume type in cinder.conf (see below)
 - Block network access from VMs to Vitastor network (to OSDs and etcd), because Vitastor doesn't support authentication (yet)
 - Restart Cinder and Nova
 Cinder volume type configuration example:
 ```
 [DEFAULT]
 enabled_backends = lvmdriver-1, vitastor-testcluster
 # ...
 [vitastor-testcluster]
 volume_driver = cinder.volume.drivers.vitastor.VitastorDriver
 volume_backend_name = vitastor-testcluster
 image_volume_cache_enabled = True
 volume_clear = none
 vitastor_etcd_address = 192.168.7.2:2379
 vitastor_etcd_prefix =
 vitastor_config_path = /etc/vitastor/vitastor.conf
 vitastor_pool_id = 1
 image_upload_use_cinder_backend = True
 ```
 To put Glance images in Vitastor, use [https://docs.openstack.org/cinder/pike/admin/blockstorage-volume-backed-image.html](volume-backed images),
 although the support has not been verified yet.
 ### Proxmox
 To enable Vitastor support in Proxmox Virtual Environment (6.4 and 7.1 are supported):
 - Add the corresponding Vitastor Debian repository into sources.list on Proxmox hosts
  (buster for 6.4, bullseye for 7.1)
 - Install vitastor-client, pve-qemu-kvm, pve-storage-vitastor (* or see note) packages from Vitastor repository
 - Define storage in `/etc/pve/storage.cfg` (see below)
 - Block network access from VMs to Vitastor network (to OSDs and etcd), because Vitastor doesn't support authentication (yet)
 - Restart pvedaemon: `systemctl restart pvedaemon`
 `/etc/pve/storage.cfg` example (the only required option is vitastor_pool, all others
 are listed below with their default values):
 ```
 vitastor: vitastor
    # pool to put new images into
    vitastor_pool testpool
    # path to the configuration file
    vitastor_config_path /etc/vitastor/vitastor.conf
    # etcd address(es), required only if missing in the configuration file
    vitastor_etcd_address 192.168.7.2:2379/v3
    # prefix for keys in etcd
    vitastor_etcd_prefix /vitastor
    # prefix for images
    vitastor_prefix pve/
    # use NBD mounter (only required for containers)
    vitastor_nbd 0
 ```
 \* Note: you can also manually copy [patches/PVE_VitastorPlugin.pm](patches/PVE_VitastorPlugin.pm) to Proxmox hosts
 as `/usr/share/perl5/PVE/Storage/Custom/VitastorPlugin.pm` instead of installing pve-storage-vitastor.
 ## Known Problems
 - Object deletion requests may currently lead to 'incomplete' objects in EC pools
  if your OSDs crash during deletion because proper handling of object cleanup
  in a cluster should be "three-phase" and it's currently not implemented.
  Just repeat the removal request again in this case.
 ## Implementation Principles
 - I like architecturally simple solutions. Vitastor is and will always be designed
  exactly like that.
 - 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+
 Join Vitastor Telegram Chat: https://t.me/vitastor
 All server-side code (OSD, Monitor and so on) is licensed under the terms of
 Vitastor Network Public License 1.1 (VNPL 1.1), 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 and expressly designed to be used in conjunction
 with it ("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.
 Please note that VNPL doesn't require you to open the code of proprietary
 software running inside a VM if it's not specially designed to be used with
 Vitastor.
 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 1.1 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-1.1 in the file [VNPL-1.1.txt](VNPL-1.1.txt).
 GPL 2.0 is also included in this repository as [GPL-2.0.txt](GPL-2.0.txt).
--- a/VNPL-1.1.txt
+++ b/VNPL-1.1.txt
@ -1,648 +0,0 @@
                     VITASTOR NETWORK PUBLIC LICENSE
                     Version 1.1,  6 February 2021
 Copyright (C) 2021 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.
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 or that patent license was granted, prior to 28 March 2007.
  Nothing in this License shall be construed as excluding or limiting
 any implied license or other defenses to infringement that may
 otherwise be available to you under applicable patent law.
  12. No Surrender of Others' Freedom.
  If conditions are imposed on you (whether by court order, agreement or
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 License and any other pertinent obligations, then as a consequence you may
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 License would be to refrain entirely from conveying the Program.
  13. Remote Network Interaction.
  A "Proxy Program" means a separate program which is specially designed to
 be used in conjunction with the covered work and interacts with it directly
 or indirectly through any kind of API (application programming interfaces),
 a computer network, an imitation of such network, or another Proxy Program
 itself.
  Notwithstanding any other provision of this License, if you provide any user
 with an opportunity to interact with the covered work through a computer
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 you must prominently offer that user an opportunity to receive the
 Corresponding Source of the covered work and all Proxy Programs from a
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 Free Software License, as described by the Free Software Foundation
 in their "GPL-Compatible License List".
  14. Revised Versions of this License.
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 the Vitastor Network Public License from time to time.  Such new versions
 will be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
  Each version is given a distinguishing version number.  If the
 Program specifies that a certain numbered version of the Vitastor Network
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version. If the Program does not specify a version
 number of the Vitastor Network Public License, you may choose any version
 ever published.
  Later license versions may give you additional or different
 permissions.  However, no additional obligations are imposed on any
 author or copyright holder as a result of your choosing to follow a
 later version.
  15. Disclaimer of Warranty.
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 APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
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 ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  16. Limitation of Liability.
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                     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
 state 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 Vitastor Network Public License as published by
    the Vitastor Author, either version 1 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
    Vitastor Network Public License for more details.
 Also add information on how to contact you by electronic and paper mail.
  If your software can interact with users remotely through a computer
 network, you should also make sure that it provides a way for users to
 get its source.  For example, if your program is a web application, its
 interface could display a "Source" link that leads users to an archive
 of the code.  There are many ways you could offer source, and different
 solutions will be better for different programs; see section 13 for the
 specific requirements.
--- a/src/allocator.cpp
+++ b/src/allocator.cpp
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #include <stdexcept>
 #include "allocator.h"
@ -13,19 +10,19 @@ allocator::allocator(uint64_t blocks)
    {
        throw std::invalid_argument("blocks");
    }
-    uint64_t p2 = 1;
+    uint64_t p2 = 1, total = 1;
    total = 0;
    while (p2 * 64 < blocks)
    {
        total += p2;
        p2 = p2 * 64;
        total += p2;
    }
    total -= p2;
    total += (blocks+63) / 64;
-    mask = new uint64_t[total];
+    mask = new uint64_t[2 + total];
    size = free = blocks;
    last_one_mask = (blocks % 64) == 0
        ? UINT64_MAX
-        : ((1l << (blocks % 64)) - 1);
+        : ~(UINT64_MAX << (64 - blocks % 64));
    for (uint64_t i = 0; i < total; i++)
    {
        mask[i] = 0;
@ -37,21 +34,6 @@ allocator::~allocator()
    delete[] mask;
 }
 bool allocator::get(uint64_t addr)
 {
    if (addr >= size)
    {
        return false;
    }
    uint64_t p2 = 1, offset = 0;
    while (p2 * 64 < size)
    {
        offset += p2;
        p2 = p2 * 64;
    }
    return ((mask[offset + addr/64] >> (addr % 64)) & 1);
 }
 void allocator::set(uint64_t addr, bool value)
 {
    if (addr >= size)
@ -114,10 +96,6 @@ uint64_t allocator::find_free()
    uint64_t p2 = 1, offset = 0, addr = 0, f, i;
    while (p2 < size)
    {
        if (offset+addr >= total)
        {
            return UINT64_MAX;
        }
        uint64_t m = mask[offset + addr];
        for (i = 0, f = 1; i < 64; i++, f <<= 1)
        {
@ -132,6 +110,11 @@ uint64_t allocator::find_free()
            return UINT64_MAX;
        }
        addr = (addr * 64) | i;
        if (addr >= size)
        {
            // No space
            return UINT64_MAX;
        }
        offset += p2;
        p2 = p2 * 64;
    }
@ -142,35 +125,3 @@ uint64_t allocator::get_free_count()
 {
    return free;
 }
 void bitmap_set(void *bitmap, uint64_t start, uint64_t len, uint64_t bitmap_granularity)
 {
    if (start == 0)
    {
        if (len == 32*bitmap_granularity)
        {
            *((uint32_t*)bitmap) = UINT32_MAX;
            return;
        }
        else if (len == 64*bitmap_granularity)
        {
            *((uint64_t*)bitmap) = UINT64_MAX;
            return;
        }
    }
    unsigned bit_start = start / bitmap_granularity;
    unsigned bit_end = ((start + len) + bitmap_granularity - 1) / bitmap_granularity;
    while (bit_start < bit_end)
    {
        if (!(bit_start & 7) && bit_end >= bit_start+8)
        {
            ((uint8_t*)bitmap)[bit_start / 8] = UINT8_MAX;
            bit_start += 8;
        }
        else
        {
            ((uint8_t*)bitmap)[bit_start / 8] |= 1 << (bit_start % 8);
            bit_start++;
        }
    }
 }
--- a/src/allocator.h
+++ b/src/allocator.h
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #pragma once
 #include <stdint.h>
@ -8,7 +5,6 @@
 // Hierarchical bitmap allocator
 class allocator
 {
    uint64_t total;
    uint64_t size;
    uint64_t free;
    uint64_t last_one_mask;
@ -16,10 +12,7 @@ class allocator
 public:
    allocator(uint64_t blocks);
    ~allocator();
    bool get(uint64_t addr);
    void set(uint64_t addr, bool value);
    uint64_t find_free();
    uint64_t get_free_count();
 };
 void bitmap_set(void *bitmap, uint64_t start, uint64_t len, uint64_t bitmap_granularity);
--- a/blockstore.cpp
+++ b/blockstore.cpp
@ -0,0 +1,61 @@
 #include "blockstore_impl.h"
 blockstore_t::blockstore_t(blockstore_config_t & config, ring_loop_t *ringloop)
 {
    impl = new blockstore_impl_t(config, ringloop);
 }
 blockstore_t::~blockstore_t()
 {
    delete impl;
 }
 void blockstore_t::loop()
 {
    impl->loop();
 }
 bool blockstore_t::is_started()
 {
    return impl->is_started();
 }
 bool blockstore_t::is_stalled()
 {
    return impl->is_stalled();
 }
 bool blockstore_t::is_safe_to_stop()
 {
    return impl->is_safe_to_stop();
 }
 void blockstore_t::enqueue_op(blockstore_op_t *op)
 {
    impl->enqueue_op(op, false);
 }
 void blockstore_t::enqueue_op_first(blockstore_op_t *op)
 {
    impl->enqueue_op(op, true);
 }
 std::unordered_map<object_id, uint64_t> & blockstore_t::get_unstable_writes()
 {
    return impl->unstable_writes;
 }
 uint32_t blockstore_t::get_block_size()
 {
    return impl->get_block_size();
 }
 uint64_t blockstore_t::get_block_count()
 {
    return impl->get_block_count();
 }
 uint32_t blockstore_t::get_disk_alignment()
 {
    return impl->get_disk_alignment();
 }
--- a/src/blockstore.h
+++ b/src/blockstore.h
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #pragma once
 #ifndef _LARGEFILE64_SOURCE
@ -9,38 +6,32 @@
 #include <stdint.h>
 #include <string>
 #include <map>
 #include <unordered_map>
 #include <functional>
 #include "object_id.h"
 #include "ringloop.h"
 #include "timerfd_manager.h"
 // 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
 #define MIN_BLOCK_SIZE 4*1024
 #define MAX_BLOCK_SIZE 128*1024*1024
 #define DEFAULT_BITMAP_GRANULARITY 4096
 #define BS_OP_MIN 1
 #define BS_OP_READ 1
 #define BS_OP_WRITE 2
-#define BS_OP_WRITE_STABLE 3
+#define BS_OP_SYNC 3
-#define BS_OP_SYNC 4
+#define BS_OP_STABLE 4
-#define BS_OP_STABLE 5
+#define BS_OP_DELETE 5
-#define BS_OP_DELETE 6
+#define BS_OP_LIST 6
-#define BS_OP_LIST 7
+#define BS_OP_ROLLBACK 7
-#define BS_OP_ROLLBACK 8
+#define BS_OP_SYNC_STAB_ALL 8
-#define BS_OP_SYNC_STAB_ALL 9
+#define BS_OP_MAX 8
 #define BS_OP_MAX 9
 #define BS_OP_PRIVATE_DATA_SIZE 256
@ -48,9 +39,9 @@
 Blockstore opcode documentation:
-## BS_OP_READ / BS_OP_WRITE / BS_OP_WRITE_STABLE
+## BS_OP_READ / BS_OP_WRITE
-Read or write object data. WRITE_STABLE writes a version that doesn't require marking as stable.
+Read or write object data.
 Input:
 - oid = requested object
@ -59,15 +50,12 @@ 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
 - offset, len = offset and length within object. length may be zero, in that case
  read operation only returns the version / write operation only bumps the version
 - buf = pre-allocated buffer for data (read) / with data (write). may be NULL if len == 0.
 - bitmap = pointer to the new 'external' object bitmap data. Its part which is respective to the
  write request is copied into the metadata area bitwise and stored there.
 Output:
 - retval = number of bytes actually read/written or negative error number (-EINVAL or -ENOSPC)
@ -104,7 +92,7 @@ Input:
 - buf = pre-allocated obj_ver_id array <len> units long
 Output:
- retval = 0 or negative error number (-EINVAL, -ENOENT if no such version or -EBUSY if not synced)
+- retval = 0 or negative error number (-EINVAL)
 ## BS_OP_SYNC_STAB_ALL
@ -122,8 +110,6 @@ 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
@ -145,7 +131,6 @@ struct blockstore_op_t
    uint32_t offset;
    uint32_t len;
    void *buf;
    void *bitmap;
    int retval;
    uint8_t private_data[BS_OP_PRIVATE_DATA_SIZE];
@ -159,7 +144,7 @@ class blockstore_t
 {
    blockstore_impl_t *impl;
 public:
-    blockstore_t(blockstore_config_t & config, ring_loop_t *ringloop, timerfd_manager_t *tfd);
+    blockstore_t(blockstore_config_t & config, ring_loop_t *ringloop);
    ~blockstore_t();
    // Event loop
@ -180,21 +165,16 @@ public:
    // Submission
    void enqueue_op(blockstore_op_t *op);
-    // Simplified synchronous operation: get object bitmap & current version
+    // Insert operation into the beginning of the queue
-    int read_bitmap(object_id oid, uint64_t target_version, void *bitmap, uint64_t *result_version = NULL);
+    // Intended for the OSD syncer "thread" to be able to stabilize something when the journal is full
    void enqueue_op_first(blockstore_op_t *op);
-    // Get per-inode space usage statistics
+    // Unstable writes are added here (map of object_id -> version)
-    std::map<uint64_t, uint64_t> & get_inode_space_stats();
+    std::unordered_map<object_id, uint64_t> & get_unstable_writes();
    // Print diagnostics to stdout
    void dump_diagnostics();
    // FIXME rename to object_size
    uint32_t get_block_size();
    uint64_t get_block_count();
    uint64_t get_free_block_count();
-    uint64_t get_journal_size();
+    uint32_t get_disk_alignment();
    uint32_t get_bitmap_granularity();
 };
--- a/src/blockstore_flush.cpp
+++ b/src/blockstore_flush.cpp
@ -1,27 +1,16 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #include "blockstore_impl.h"
-journal_flusher_t::journal_flusher_t(blockstore_impl_t *bs)
+journal_flusher_t::journal_flusher_t(int flusher_count, blockstore_impl_t *bs)
 {
    this->bs = bs;
-    this->max_flusher_count = bs->max_flusher_count;
+    this->flusher_count = flusher_count;
    this->min_flusher_count = bs->min_flusher_count;
    this->cur_flusher_count = bs->min_flusher_count;
    this->target_flusher_count = bs->min_flusher_count;
    dequeuing = false;
    trimming = false;
    active_flushers = 0;
-    syncing_flushers = 0;
+    sync_threshold = flusher_count == 1 ? 1 : flusher_count/2;
-    // FIXME: allow to configure flusher_start_threshold and journal_trim_interval
+    journal_trim_interval = sync_threshold;
-    flusher_start_threshold = bs->journal_block_size / sizeof(journal_entry_stable);
+    journal_trim_counter = 0;
-    journal_trim_interval = 512;
+    journal_superblock = bs->journal.inmemory ? bs->journal.buffer : memalign(MEM_ALIGNMENT, bs->journal_block_size);
-    journal_trim_counter = bs->journal.flush_journal ? 1 : 0;
+    co = new journal_flusher_co[flusher_count];
-    trim_wanted = bs->journal.flush_journal ? 1 : 0;
+    for (int i = 0; i < flusher_count; i++)
    journal_superblock = bs->journal.inmemory ? bs->journal.buffer : memalign_or_die(MEM_ALIGNMENT, bs->journal_block_size);
    co = new journal_flusher_co[max_flusher_count];
    for (int i = 0; i < max_flusher_count; i++)
    {
        co[i].bs = bs;
        co[i].flusher = this;
@ -66,36 +55,23 @@ journal_flusher_t::~journal_flusher_t()
 bool journal_flusher_t::is_active()
 {
-    return active_flushers > 0 || dequeuing;
+    return active_flushers > 0 || start_forced && flush_queue.size() > 0 || flush_queue.size() >= sync_threshold;
 }
 void journal_flusher_t::loop()
 {
-    target_flusher_count = bs->write_iodepth*2;
+    for (int i = 0; i < flusher_count; i++)
    if (target_flusher_count < min_flusher_count)
        target_flusher_count = min_flusher_count;
    else if (target_flusher_count > max_flusher_count)
        target_flusher_count = max_flusher_count;
    if (target_flusher_count > cur_flusher_count)
        cur_flusher_count = target_flusher_count;
    else if (target_flusher_count < cur_flusher_count)
    {
-        while (target_flusher_count < cur_flusher_count)
+        if (!active_flushers && (start_forced ? !flush_queue.size() : (flush_queue.size() < sync_threshold)))
        {
-            if (co[cur_flusher_count-1].wait_state)
+            return;
                break;
            cur_flusher_count--;
        }
    }
    for (int i = 0; (active_flushers > 0 || dequeuing) && i < cur_flusher_count; i++)
        co[i].loop();
    }
 }
 void journal_flusher_t::enqueue_flush(obj_ver_id ov)
 {
 #ifdef BLOCKSTORE_DEBUG
    printf("enqueue_flush %lx:%lx v%lu\n", ov.oid.inode, ov.oid.stripe, ov.version);
 #endif
    auto it = flush_versions.find(ov.oid);
    if (it != flush_versions.end())
    {
@ -107,18 +83,10 @@ 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 || trim_wanted > 0))
    {
        dequeuing = true;
        bs->ringloop->wakeup();
    }
 }
-void journal_flusher_t::unshift_flush(obj_ver_id ov, bool force)
+void journal_flusher_t::unshift_flush(obj_ver_id ov)
 {
 #ifdef BLOCKSTORE_DEBUG
    printf("unshift_flush %lx:%lx v%lu\n", ov.oid.inode, ov.oid.stripe, ov.version);
 #endif
    auto it = flush_versions.find(ov.oid);
    if (it != flush_versions.end())
    {
@ -128,128 +96,15 @@ void journal_flusher_t::unshift_flush(obj_ver_id ov, bool force)
    else
    {
        flush_versions[ov.oid] = ov.version;
        if (!force)
        flush_queue.push_front(ov.oid);
    }
-    if (force)
+}
-        flush_queue.push_front(ov.oid);
+
-    if (force || !dequeuing && (flush_queue.size() >= flusher_start_threshold || trim_wanted > 0))
+void journal_flusher_t::force_start()
 {
-        dequeuing = true;
+    start_forced = true;
    bs->ringloop->wakeup();
 }
 }
 void journal_flusher_t::remove_flush(object_id oid)
 {
 #ifdef BLOCKSTORE_DEBUG
    printf("undo_flush %lx:%lx\n", oid.inode, oid.stripe);
 #endif
    auto v_it = flush_versions.find(oid);
    if (v_it != flush_versions.end())
    {
        flush_versions.erase(v_it);
        for (auto q_it = flush_queue.begin(); q_it != flush_queue.end(); q_it++)
        {
            if (*q_it == oid)
            {
                flush_queue.erase(q_it);
                break;
            }
        }
    }
 }
 void journal_flusher_t::request_trim()
 {
    dequeuing = true;
    trim_wanted++;
    bs->ringloop->wakeup();
 }
 void journal_flusher_t::mark_trim_possible()
 {
    if (trim_wanted > 0)
    {
        dequeuing = true;
        journal_trim_counter++;
        bs->ringloop->wakeup();
    }
 }
 void journal_flusher_t::release_trim()
 {
    trim_wanted--;
 }
 void journal_flusher_t::dump_diagnostics()
 {
    const char *unflushable_type = "";
    obj_ver_id unflushable = { 0 };
    // Try to find out if there is a flushable object for information
    for (object_id cur_oid: flush_queue)
    {
        obj_ver_id cur = { .oid = cur_oid, .version = flush_versions[cur_oid] };
        auto dirty_end = bs->dirty_db.find(cur);
        if (dirty_end == bs->dirty_db.end())
        {
            // Already flushed
            continue;
        }
        auto repeat_it = sync_to_repeat.find(cur.oid);
        if (repeat_it != sync_to_repeat.end())
        {
            // Someone is already flushing it
            unflushable_type = "locked,";
            unflushable = cur;
            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))
        {
            // Object is more recent than possible to flush
            bool found = try_find_older(dirty_end, cur);
            if (!found)
            {
                unflushable_type = "dirty,";
                unflushable = cur;
                break;
            }
        }
        unflushable_type = "ok,";
        unflushable = cur;
        break;
    }
    printf(
        "Flusher: queued=%ld first=%s%lx:%lx trim_wanted=%d dequeuing=%d trimming=%d cur=%d target=%d active=%d syncing=%d\n",
        flush_queue.size(), unflushable_type, unflushable.oid.inode, unflushable.oid.stripe,
        trim_wanted, dequeuing, trimming, cur_flusher_count, target_flusher_count,
        active_flushers, syncing_flushers
    );
 }
 bool journal_flusher_t::try_find_older(std::map<obj_ver_id, dirty_entry>::iterator & dirty_end, obj_ver_id & cur)
 {
    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;
        }
    }
    return found;
 }
 #define await_sqe(label) \
    resume_##label:\
@ -261,7 +116,6 @@ bool journal_flusher_t::try_find_older(std::map<obj_ver_id, dirty_entry>::iterat
        }\
        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
@ -300,24 +154,11 @@ bool journal_flusher_co::loop()
        goto resume_17;
    else if (wait_state == 18)
        goto resume_18;
    else if (wait_state == 19)
        goto resume_19;
    else if (wait_state == 20)
        goto resume_20;
    else if (wait_state == 21)
        goto resume_21;
 resume_0:
-    if (flusher->flush_queue.size() < flusher->min_flusher_count && !flusher->trim_wanted ||
+    if (!flusher->flush_queue.size() ||
-        !flusher->flush_queue.size() || !flusher->dequeuing)
+        !flusher->start_forced && !flusher->active_flushers && flusher->flush_queue.size() < flusher->sync_threshold)
    {
-stop_flusher:
+        flusher->start_forced = false;
        if (flusher->trim_wanted > 0 && flusher->journal_trim_counter > 0)
        {
            // Attempt forced trim
            flusher->active_flushers++;
            goto trim_journal;
        }
        flusher->dequeuing = false;
        wait_state = 0;
        return true;
    }
@ -332,7 +173,7 @@ stop_flusher:
        if (repeat_it != flusher->sync_to_repeat.end())
        {
 #ifdef BLOCKSTORE_DEBUG
-            printf("Postpone %lx:%lx v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
+            printf("Postpone %lu:%lu 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
@ -345,100 +186,42 @@ stop_flusher:
        }
        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 = flusher->try_find_older(dirty_end, cur);
            if (!found)
            {
                // Try other objects
                flusher->sync_to_repeat.erase(cur.oid);
                int search_left = flusher->flush_queue.size() - 1;
 #ifdef BLOCKSTORE_DEBUG
-                printf("Flusher overran writers (%lx:%lx v%lu, dirty_start=%08lx) - searching for older flushes (%d left)\n",
+        printf("Flushing %lu:%lu v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
                    cur.oid.inode, cur.oid.stripe, cur.version, 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())
                            {
                                if (repeat_it->second < cur.version)
                                    repeat_it->second = cur.version;
                            }
                            else
                            {
                                flusher->sync_to_repeat[cur.oid] = 0;
                                break;
                            }
                        }
                    }
                    search_left--;
                }
                if (search_left <= 0)
                {
 #ifdef BLOCKSTORE_DEBUG
                    printf("No older flushes, stopping\n");
 #endif
                    goto stop_flusher;
                }
            }
        }
 #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;
        }
-        // Writes and deletes shouldn't happen at the same time
+        if (copy_count == 0 && clean_loc == UINT64_MAX && !has_delete && !has_empty)
        assert(!has_writes || !has_delete);
        if (!has_writes && !has_delete || has_delete && old_clean_loc == UINT64_MAX)
        {
            // Nothing to flush
-            bs->erase_dirty(dirty_start, std::next(dirty_end), clean_loc);
+            flusher->active_flushers--;
-            goto release_oid;
+            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;
        }
        // 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 (old_clean_loc == UINT64_MAX)
+            if (copy_count > 0 && has_delete || old_clean_loc == UINT64_MAX)
            {
                // Object not allocated. This is a bug.
                char err[1024];
                snprintf(
-                    err, 1024, "BUG: Object %lx:%lx v%lu that we are trying to flush is not allocated on the data device",
+                    err, 1024, "BUG: Object %lu:%lu 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);
@ -487,18 +270,18 @@ resume_1:
        {
            new_clean_bitmap = (bs->inmemory_meta
                ? meta_new.buf + meta_new.pos*bs->clean_entry_size + sizeof(clean_disk_entry)
-                : bs->clean_bitmap + (clean_loc >> bs->block_order)*(2*bs->clean_entry_bitmap_size));
+                : bs->clean_bitmap + (clean_loc >> bs->block_order)*bs->clean_entry_bitmap_size);
            if (clean_init_bitmap)
            {
                memset(new_clean_bitmap, 0, bs->clean_entry_bitmap_size);
-                bitmap_set(new_clean_bitmap, clean_bitmap_offset, clean_bitmap_len, bs->bitmap_granularity);
+                bitmap_set(new_clean_bitmap, clean_bitmap_offset, clean_bitmap_len);
            }
        }
        for (it = v.begin(); it != v.end(); it++)
        {
            if (new_clean_bitmap)
            {
-                bitmap_set(new_clean_bitmap, it->offset, it->len, bs->bitmap_granularity);
+                bitmap_set(new_clean_bitmap, it->offset, it->len);
            }
            await_sqe(4);
            data->iov = (struct iovec){ it->buf, (size_t)it->len };
@ -532,7 +315,6 @@ resume_1:
                wait_state = 5;
                return false;
            }
            // zero out old metadata entry
            memset(meta_old.buf + meta_old.pos*bs->clean_entry_size, 0, bs->clean_entry_size);
            await_sqe(15);
            data->iov = (struct iovec){ meta_old.buf, bs->meta_block_size };
@ -544,39 +326,17 @@ resume_1:
        }
        if (has_delete)
        {
            clean_disk_entry *new_entry = (clean_disk_entry*)(meta_new.buf + meta_new.pos*bs->clean_entry_size);
            if (new_entry->oid.inode != 0 && new_entry->oid != cur.oid)
            {
                printf("Fatal error (metadata corruption or bug): tried to delete metadata entry %lu (%lx:%lx v%lu) while deleting %lx:%lx\n",
                    clean_loc >> bs->block_order, new_entry->oid.inode, new_entry->oid.stripe,
                    new_entry->version, cur.oid.inode, cur.oid.stripe);
                exit(1);
            }
            // zero out new metadata entry
            memset(meta_new.buf + meta_new.pos*bs->clean_entry_size, 0, bs->clean_entry_size);
        }
        else
        {
            clean_disk_entry *new_entry = (clean_disk_entry*)(meta_new.buf + meta_new.pos*bs->clean_entry_size);
            if (new_entry->oid.inode != 0 && new_entry->oid != cur.oid)
            {
                printf("Fatal error (metadata corruption or bug): tried to overwrite non-zero metadata entry %lu (%lx:%lx v%lu) with %lx:%lx v%lu\n",
                    clean_loc >> bs->block_order, new_entry->oid.inode, new_entry->oid.stripe, new_entry->version,
                    cur.oid.inode, cur.oid.stripe, cur.version);
                exit(1);
            }
            new_entry->oid = cur.oid;
            new_entry->version = cur.version;
            if (!bs->inmemory_meta)
            {
                memcpy(&new_entry->bitmap, new_clean_bitmap, bs->clean_entry_bitmap_size);
            }
            // copy latest external bitmap/attributes
            if (bs->clean_entry_bitmap_size)
            {
                void *bmp_ptr = bs->clean_entry_bitmap_size > sizeof(void*) ? dirty_end->second.bitmap : &dirty_end->second.bitmap;
                memcpy((void*)(new_entry+1) + bs->clean_entry_bitmap_size, bmp_ptr, bs->clean_entry_bitmap_size);
            }
        }
        await_sqe(6);
        data->iov = (struct iovec){ meta_new.buf, bs->meta_block_size };
@ -626,35 +386,13 @@ resume_1:
        }
        // Update clean_db and dirty_db, free old data locations
        update_clean_db();
 #ifdef BLOCKSTORE_DEBUG
        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
    release_oid:
        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 }, false);
        }
        flusher->sync_to_repeat.erase(repeat_it);
    trim_journal:
        // Clear unused part of the journal every <journal_trim_interval> flushes
-        if (!((++flusher->journal_trim_counter) % flusher->journal_trim_interval) || flusher->trim_wanted > 0)
+        if (!((++flusher->journal_trim_counter) % flusher->journal_trim_interval))
        {
            flusher->journal_trim_counter = 0;
-            new_trim_pos = bs->journal.get_trim_pos();
+            if (bs->journal.trim())
            if (new_trim_pos != bs->journal.used_start)
            {
-            resume_19:
+                // Update journal "superblock"
                // Wait for other coroutines trimming the journal, if any
                if (flusher->trimming)
                {
                    wait_state = 19;
                    return false;
                }
                flusher->trimming = true;
                // First update journal "superblock" and only then update <used_start> in memory
                await_sqe(12);
                *((journal_entry_start*)flusher->journal_superblock) = {
                    .crc32 = 0,
@ -662,8 +400,7 @@ resume_1:
                    .type = JE_START,
                    .size = sizeof(journal_entry_start),
                    .reserved = 0,
-                    .journal_start = new_trim_pos,
+                    .journal_start = bs->journal.used_start,
                    .version = JOURNAL_VERSION,
                };
                ((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 };
@ -676,34 +413,20 @@ resume_1:
                    wait_state = 13;
                    return false;
                }
                if (!bs->disable_journal_fsync)
                {
                    await_sqe(20);
                    my_uring_prep_fsync(sqe, bs->journal.fd, IORING_FSYNC_DATASYNC);
                    data->iov = { 0 };
                    data->callback = simple_callback_w;
                resume_21:
                    if (wait_count > 0)
                    {
                        wait_state = 21;
                        return false;
                    }
                }
                bs->journal.used_start = new_trim_pos;
 #ifdef BLOCKSTORE_DEBUG
                printf("Journal trimmed to %08lx (next_free=%08lx)\n", bs->journal.used_start, bs->journal.next_free);
 #endif
                flusher->trimming = false;
            }
            if (bs->journal.flush_journal && !flusher->flush_queue.size())
            {
                assert(bs->journal.used_start == bs->journal.next_free);
                printf("Journal flushed\n");
                exit(0);
            }
        }
        // All done
 #ifdef BLOCKSTORE_DEBUG
        printf("Flushed %lu:%lu v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
        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;
    }
@ -722,53 +445,44 @@ bool journal_flusher_co::scan_dirty(int wait_base)
    copy_count = 0;
    clean_loc = UINT64_MAX;
    has_delete = false;
-    has_writes = false;
+    has_empty = false;
    skip_copy = false;
    clean_init_bitmap = false;
    while (1)
    {
-        if (!IS_STABLE(dirty_it->second.state))
+        if (dirty_it->second.state == ST_J_STABLE && !skip_copy)
        {
            char err[1024];
            snprintf(
                err, 1024, "BUG: Unexpected dirty_entry %lx:%lx v%lu unstable state during flush: 0x%x",
                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
-            has_writes = true;
+            if (dirty_it->second.len == 0)
-            if (dirty_it->second.len != 0)
+            {
                has_empty = true;
            }
            else
            {
                offset = dirty_it->second.offset;
                end_offset = dirty_it->second.offset + dirty_it->second.len;
                it = v.begin();
-                while (end_offset > offset)
+                while (1)
                {
                    for (; it != v.end(); it++)
-                        if (it->offset+it->len > offset)
+                        if (it->offset >= offset)
                            break;
-                    // If all items end before offset or if the found item starts after end_offset, just insert the buffer
+                    if (it == v.end() || it->offset > offset && it->len > 0)
                    // If (offset < it->offset < end_offset) insert (offset..it->offset) part
                    // If (it->offset <= offset <= it->offset+it->len) then just skip to it->offset+it->len
                    if (it == v.end() || it->offset > offset)
                    {
                        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_or_die(MEM_ALIGNMENT, submit_len) });
+                        it = v.insert(it, (copy_buffer_t){ .offset = offset, .len = submit_len, .buf = memalign(MEM_ALIGNMENT, submit_len) });
                        copy_count++;
                        if (bs->journal.inmemory)
                        {
                            // Take it from memory
-                            memcpy(it->buf, bs->journal.buffer + submit_offset, submit_len);
+                            memcpy(v.back().buf, bs->journal.buffer + submit_offset, submit_len);
                        }
                        else
                        {
                            // Read it from disk
                            await_sqe(0);
-                            data->iov = (struct iovec){ it->buf, (size_t)submit_len };
+                            data->iov = (struct iovec){ v.back().buf, (size_t)submit_len };
                            data->callback = simple_callback_r;
                            my_uring_prep_readv(
                                sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset + submit_offset
@ -777,27 +491,35 @@ bool journal_flusher_co::scan_dirty(int wait_base)
                        }
                    }
                    offset = it->offset+it->len;
-                    if (it == v.end())
+                    if (it == v.end() || offset >= end_offset)
                        break;
                }
            }
        }
-        else if (IS_BIG_WRITE(dirty_it->second.state) && !skip_copy)
+        else if (dirty_it->second.state == ST_D_STABLE && !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 (IS_DELETE(dirty_it->second.state) && !skip_copy)
+        else if (dirty_it->second.state == ST_DEL_STABLE && !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())
        {
@ -833,7 +555,7 @@ 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_or_die(MEM_ALIGNMENT, bs->meta_block_size);
+        wr.buf = memalign(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,
@ -863,10 +585,7 @@ 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 from %lx:%lx v%lu (new location is %lu)\n",
+        printf("Free block %lu\n", old_clean_loc >> bs->block_order);
            old_clean_loc >> bs->block_order,
            cur.oid.inode, cur.oid.stripe, cur.version,
            clean_loc >> bs->block_order);
 #endif
        bs->data_alloc->set(old_clean_loc >> bs->block_order, false);
    }
@ -874,11 +593,6 @@ void journal_flusher_co::update_clean_db()
    {
        auto clean_it = bs->clean_db.find(cur.oid);
        bs->clean_db.erase(clean_it);
 #ifdef BLOCKSTORE_DEBUG
        printf("Free block %lu from %lx:%lx v%lu (delete)\n",
            clean_loc >> bs->block_order,
            cur.oid.inode, cur.oid.stripe, cur.version);
 #endif
        bs->data_alloc->set(clean_loc >> bs->block_order, false);
        clean_loc = UINT64_MAX;
    }
@ -900,7 +614,7 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
        goto resume_1;
    else if (wait_state == wait_base+2)
        goto resume_2;
-    if (!(fsync_meta ? bs->disable_meta_fsync : bs->disable_data_fsync))
+    if (!(fsync_meta ? bs->disable_meta_fsync : bs->disable_journal_fsync))
    {
        cur_sync = flusher->syncs.end();
        while (cur_sync != flusher->syncs.begin())
@ -918,11 +632,7 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
        });
    sync_found:
        cur_sync->ready_count++;
-        flusher->syncing_flushers++;
+        if (cur_sync->ready_count >= flusher->sync_threshold || !flusher->flush_queue.size())
    resume_1:
        if (!cur_sync->state)
        {
            if (flusher->syncing_flushers >= flusher->cur_flusher_count || !flusher->flush_queue.size())
        {
            // Sync batch is ready. Do it.
            await_sqe(0);
@ -931,24 +641,23 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
            my_uring_prep_fsync(sqe, fsync_meta ? bs->meta_fd : bs->data_fd, IORING_FSYNC_DATASYNC);
            cur_sync->state = 1;
            wait_count++;
-            resume_2:
+        resume_1:
            if (wait_count > 0)
            {
-                    wait_state = 2;
+                wait_state = 1;
                return false;
            }
            // Sync completed. All previous coroutines waiting for it must be resumed
            cur_sync->state = 2;
            bs->ringloop->wakeup();
        }
            else
            {
        // Wait until someone else sends and completes a sync.
-                wait_state = 1;
+    resume_2:
        if (!cur_sync->state)
        {
            wait_state = 2;
            return false;
        }
        }
        flusher->syncing_flushers--;
        cur_sync->ready_count--;
        if (cur_sync->ready_count == 0)
        {
@ -957,3 +666,35 @@ bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
    }
    return true;
 }
 void journal_flusher_co::bitmap_set(void *bitmap, uint64_t start, uint64_t len)
 {
    if (start == 0)
    {
        if (len == 32*bs->bitmap_granularity)
        {
            *((uint32_t*)bitmap) = UINT32_MAX;
            return;
        }
        else if (len == 64*bs->bitmap_granularity)
        {
            *((uint64_t*)bitmap) = UINT64_MAX;
            return;
        }
    }
    unsigned bit_start = start / bs->bitmap_granularity;
    unsigned bit_end = ((start + len) + bs->bitmap_granularity - 1) / bs->bitmap_granularity;
    while (bit_start < bit_end)
    {
        if (!(bit_start & 7) && bit_end >= bit_start+8)
        {
            ((uint8_t*)bitmap)[bit_start / 8] = UINT8_MAX;
            bit_start += 8;
        }
        else
        {
            ((uint8_t*)bitmap)[bit_start / 8] |= 1 << (bit_start % 8);
            bit_start++;
        }
    }
 }
--- a/src/blockstore_flush.h
+++ b/src/blockstore_flush.h
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 struct copy_buffer_t
 {
    uint64_t offset, len;
@ -48,8 +45,8 @@ 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_writes;
+    bool skip_copy, has_delete, has_empty;
-    blockstore_clean_db_t::iterator clean_it;
+    spp::sparse_hash_map<object_id, clean_entry>::iterator clean_it;
    std::vector<copy_buffer_t> v;
    std::vector<copy_buffer_t>::iterator it;
    int copy_count;
@ -59,8 +56,6 @@ class journal_flusher_co
    uint64_t clean_bitmap_offset, clean_bitmap_len;
    void *new_clean_bitmap;
    uint64_t new_trim_pos;
    // local: scan_dirty()
    uint64_t offset, end_offset, submit_offset, submit_len;
@ -69,6 +64,7 @@ class journal_flusher_co
    bool modify_meta_read(uint64_t meta_loc, flusher_meta_write_t &wr, int wait_base);
    void update_clean_db();
    bool fsync_batch(bool fsync_meta, int wait_base);
    void bitmap_set(void *bitmap, uint64_t start, uint64_t len);
 public:
    journal_flusher_co();
    bool loop();
@ -77,39 +73,29 @@ public:
 // Journal flusher itself
 class journal_flusher_t
 {
-    int trim_wanted = 0;
+    bool start_forced = false;
-    bool dequeuing;
+    int flusher_count;
-    int min_flusher_count, max_flusher_count, cur_flusher_count, target_flusher_count;
+    int sync_threshold;
    int flusher_start_threshold;
    journal_flusher_co *co;
    blockstore_impl_t *bs;
    friend class journal_flusher_co;
    int journal_trim_counter, journal_trim_interval;
    bool trimming;
    void* journal_superblock;
    int active_flushers;
    int syncing_flushers;
    std::list<flusher_sync_t> syncs;
    std::map<object_id, uint64_t> sync_to_repeat;
    std::map<uint64_t, meta_sector_t> meta_sectors;
    std::deque<object_id> flush_queue;
    std::map<object_id, uint64_t> flush_versions;
    bool try_find_older(std::map<obj_ver_id, dirty_entry>::iterator & dirty_end, obj_ver_id & cur);
 public:
-    journal_flusher_t(blockstore_impl_t *bs);
+    journal_flusher_t(int flusher_count, blockstore_impl_t *bs);
    ~journal_flusher_t();
    void loop();
    bool is_active();
-    void mark_trim_possible();
+    void force_start();
    void request_trim();
    void release_trim();
    void enqueue_flush(obj_ver_id oid);
-    void unshift_flush(obj_ver_id oid, bool force);
+    void unshift_flush(obj_ver_id oid);
    void remove_flush(object_id oid);
    void dump_diagnostics();
 };
--- a/blockstore_impl.cpp
+++ b/blockstore_impl.cpp
@ -0,0 +1,458 @@
 #include "blockstore_impl.h"
 blockstore_impl_t::blockstore_impl_t(blockstore_config_t & config, ring_loop_t *ringloop)
 {
    assert(sizeof(blockstore_op_private_t) <= BS_OP_PRIVATE_DATA_SIZE);
    this->ringloop = ringloop;
    ring_consumer.loop = [this]() { loop(); };
    ringloop->register_consumer(ring_consumer);
    initialized = 0;
    zero_object = (uint8_t*)memalign(MEM_ALIGNMENT, block_size);
    data_fd = meta_fd = journal.fd = -1;
    parse_config(config);
    try
    {
        open_data();
        open_meta();
        open_journal();
        calc_lengths();
        data_alloc = new allocator(block_count);
    }
    catch (std::exception & e)
    {
        if (data_fd >= 0)
            close(data_fd);
        if (meta_fd >= 0 && meta_fd != data_fd)
            close(meta_fd);
        if (journal.fd >= 0 && journal.fd != meta_fd)
            close(journal.fd);
        throw;
    }
    flusher = new journal_flusher_t(flusher_count, this);
 }
 blockstore_impl_t::~blockstore_impl_t()
 {
    delete data_alloc;
    delete flusher;
    free(zero_object);
    ringloop->unregister_consumer(ring_consumer);
    if (data_fd >= 0)
        close(data_fd);
    if (meta_fd >= 0 && meta_fd != data_fd)
        close(meta_fd);
    if (journal.fd >= 0 && journal.fd != meta_fd)
        close(journal.fd);
    if (metadata_buffer)
        free(metadata_buffer);
    if (clean_bitmap)
        free(clean_bitmap);
 }
 bool blockstore_impl_t::is_started()
 {
    return initialized == 10;
 }
 bool blockstore_impl_t::is_stalled()
 {
    return queue_stall;
 }
 // main event loop - produce requests
 void blockstore_impl_t::loop()
 {
    // FIXME: initialized == 10 is ugly
    if (initialized != 10)
    {
        // read metadata, then journal
        if (initialized == 0)
        {
            metadata_init_reader = new blockstore_init_meta(this);
            initialized = 1;
        }
        if (initialized == 1)
        {
            int res = metadata_init_reader->loop();
            if (!res)
            {
                delete metadata_init_reader;
                metadata_init_reader = NULL;
                journal_init_reader = new blockstore_init_journal(this);
                initialized = 2;
            }
        }
        if (initialized == 2)
        {
            int res = journal_init_reader->loop();
            if (!res)
            {
                delete journal_init_reader;
                journal_init_reader = NULL;
                initialized = 10;
                ringloop->wakeup();
            }
        }
    }
    else
    {
        // try to submit ops
        unsigned initial_ring_space = ringloop->space_left();
        auto cur_sync = in_progress_syncs.begin();
        while (cur_sync != in_progress_syncs.end())
        {
            continue_sync(*cur_sync++);
        }
        auto cur = submit_queue.begin();
        int has_writes = 0;
        while (cur != submit_queue.end())
        {
            auto op_ptr = cur;
            auto op = *(cur++);
            // FIXME: This needs some simplification
            // Writes should not block reads if the ring is not full and reads don't depend on them
            // In all other cases we should stop submission
            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)
                    {
                        has_writes = 2;
                    }
                    continue;
                }
            }
            unsigned ring_space = ringloop->space_left();
            unsigned prev_sqe_pos = ringloop->save();
            int dequeue_op = 0;
            if (op->opcode == BS_OP_READ)
            {
                dequeue_op = dequeue_read(op);
            }
            else if (op->opcode == BS_OP_WRITE || op->opcode == BS_OP_DELETE)
            {
                if (has_writes == 2)
                {
                    // Some writes could not be submitted
                    break;
                }
                dequeue_op = dequeue_write(op);
                has_writes = dequeue_op ? 1 : 2;
            }
            else if (op->opcode == BS_OP_SYNC)
            {
                // wait for all small writes to be submitted
                // wait for all big writes to complete, submit data device fsync
                // wait for the data device fsync to complete, then submit journal writes for big writes
                // then submit an fsync operation
                if (has_writes)
                {
                    // Can't submit SYNC before previous writes
                    continue;
                }
                dequeue_op = dequeue_sync(op);
            }
            else if (op->opcode == BS_OP_STABLE)
            {
                dequeue_op = dequeue_stable(op);
            }
            else if (op->opcode == BS_OP_ROLLBACK)
            {
                dequeue_op = dequeue_rollback(op);
            }
            else if (op->opcode == BS_OP_LIST)
            {
                process_list(op);
                dequeue_op = true;
            }
            if (dequeue_op)
            {
                submit_queue.erase(op_ptr);
            }
            else
            {
                ringloop->restore(prev_sqe_pos);
                if (PRIV(op)->wait_for == WAIT_SQE)
                {
                    PRIV(op)->wait_detail = 1 + ring_space;
                    // ring is full, stop submission
                    break;
                }
            }
        }
        if (!readonly)
        {
            flusher->loop();
        }
        int ret = ringloop->submit();
        if (ret < 0)
        {
            throw std::runtime_error(std::string("io_uring_submit: ") + strerror(-ret));
        }
        if ((initial_ring_space - ringloop->space_left()) > 0)
        {
            live = true;
        }
        queue_stall = !live && !ringloop->get_loop_again();
        live = false;
    }
 }
 bool blockstore_impl_t::is_safe_to_stop()
 {
    // It's safe to stop blockstore when there are no in-flight operations,
    // no in-progress syncs and flusher isn't doing anything
    if (submit_queue.size() > 0 || in_progress_syncs.size() > 0 || !readonly && flusher->is_active())
    {
        return false;
    }
    if (unsynced_big_writes.size() > 0 || unsynced_small_writes.size() > 0)
    {
        if (!readonly && !stop_sync_submitted)
        {
            // We should sync the blockstore before unmounting
            blockstore_op_t *op = new blockstore_op_t;
            op->opcode = BS_OP_SYNC;
            op->buf = NULL;
            op->callback = [](blockstore_op_t *op)
            {
                delete op;
            };
            enqueue_op(op);
            stop_sync_submitted = true;
        }
        return false;
    }
    return true;
 }
 void blockstore_impl_t::check_wait(blockstore_op_t *op)
 {
    if (PRIV(op)->wait_for == WAIT_SQE)
    {
        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
            return;
        }
        PRIV(op)->wait_for = 0;
    }
    else if (PRIV(op)->wait_for == WAIT_JOURNAL)
    {
        if (journal.used_start == PRIV(op)->wait_detail)
        {
            // do not submit
            return;
        }
        PRIV(op)->wait_for = 0;
    }
    else if (PRIV(op)->wait_for == WAIT_JOURNAL_BUFFER)
    {
        int next = ((journal.cur_sector + 1) % journal.sector_count);
        if (journal.sector_info[next].usage_count > 0 ||
            journal.sector_info[next].dirty)
        {
            // do not submit
            return;
        }
        PRIV(op)->wait_for = 0;
    }
    else if (PRIV(op)->wait_for == WAIT_FREE)
    {
        if (!data_alloc->get_free_count() && !flusher->is_active())
        {
            return;
        }
        PRIV(op)->wait_for = 0;
    }
    else
    {
        throw std::runtime_error("BUG: op->wait_for value is unexpected");
    }
 }
 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->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)
    {
        // Basic verification not passed
        op->retval = -EINVAL;
        op->callback(op);
        return;
    }
    if (op->opcode == BS_OP_SYNC_STAB_ALL)
    {
        std::function<void(blockstore_op_t*)> *old_callback = new std::function<void(blockstore_op_t*)>(op->callback);
        op->opcode = BS_OP_SYNC;
        op->callback = [this, old_callback](blockstore_op_t *op)
        {
            if (op->retval >= 0 && unstable_writes.size() > 0)
            {
                op->opcode = BS_OP_STABLE;
                op->len = unstable_writes.size();
                obj_ver_id *vers = new obj_ver_id[op->len];
                op->buf = vers;
                int i = 0;
                for (auto it = unstable_writes.begin(); it != unstable_writes.end(); it++, i++)
                {
                    vers[i] = {
                        .oid = it->first,
                        .version = it->second,
                    };
                }
                unstable_writes.clear();
                op->callback = [this, old_callback](blockstore_op_t *op)
                {
                    obj_ver_id *vers = (obj_ver_id*)op->buf;
                    delete[] vers;
                    op->buf = NULL;
                    (*old_callback)(op);
                    delete old_callback;
                };
                this->enqueue_op(op);
            }
            else
            {
                (*old_callback)(op);
                delete old_callback;
            }
        };
    }
    if (op->opcode == BS_OP_WRITE && !enqueue_write(op))
    {
        op->callback(op);
        return;
    }
    if (0 && op->opcode == BS_OP_SYNC && immediate_commit)
    {
        op->retval = 0;
        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)->pending_ops = 0;
    if (!first)
    {
        submit_queue.push_back(op);
    }
    else
    {
        submit_queue.push_front(op);
    }
    ringloop->wakeup();
 }
 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))
    {
        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)
    {
        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)
        {
            vers[i++] = {
                .oid = it->first,
                .version = it->second.version,
            };
        }
    }
    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)
        {
            if (IS_STABLE(it->second.state))
            {
                vers[i++] = it->first;
            }
            else
            {
                vers[j++] = it->first;
            }
        }
    }
    FINISH_OP(op);
 }
--- a/src/blockstore_impl.h
+++ b/src/blockstore_impl.h
@ -1,16 +1,14 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (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 <time.h>
 #include <unistd.h>
 #include <malloc.h>
 #include <linux/fs.h>
 #include <vector>
@ -18,49 +16,43 @@
 #include <deque>
 #include <new>
-#include "cpp-btree/btree_map.h"
+#include "sparsepp/sparsepp/spp.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 BS_ST_SMALL_WRITE 0x01
+#define ST_J_IN_FLIGHT 1
-#define BS_ST_BIG_WRITE 0x02
+#define ST_J_SUBMITTED 2
-#define BS_ST_DELETE 0x03
+#define ST_J_WRITTEN 3
 #define ST_J_SYNCED 4
 #define ST_J_STABLE 5
-#define BS_ST_WAIT_DEL 0x10
+#define ST_D_IN_FLIGHT 15
-#define BS_ST_WAIT_BIG 0x20
+#define ST_D_SUBMITTED 16
-#define BS_ST_IN_FLIGHT 0x30
+#define ST_D_WRITTEN 17
-#define BS_ST_SUBMITTED 0x40
+#define ST_D_META_WRITTEN 19
-#define BS_ST_WRITTEN 0x50
+#define ST_D_META_SYNCED 20
-#define BS_ST_SYNCED 0x60
+#define ST_D_STABLE 21
 #define BS_ST_STABLE 0x70
-#define BS_ST_INSTANT 0x100
+#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 IMMEDIATE_NONE 0
+#define ST_CURRENT 48
 #define IMMEDIATE_SMALL 1
 #define IMMEDIATE_ALL 2
-#define BS_ST_TYPE_MASK 0x0F
+#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 BS_ST_WORKFLOW_MASK 0xF0
+#define IS_STABLE(st) (st == ST_J_STABLE || st == ST_D_STABLE || st == ST_DEL_STABLE || st == ST_CURRENT)
-#define IS_IN_FLIGHT(st) (((st) & 0xF0) <= BS_ST_SUBMITTED)
+#define IS_SYNCED(st) (IS_STABLE(st) || st == ST_J_SYNCED || st == ST_D_META_SYNCED || st == ST_DEL_SYNCED)
-#define IS_STABLE(st) (((st) & 0xF0) == BS_ST_STABLE)
+#define IS_JOURNAL(st) (st >= ST_J_SUBMITTED && st <= ST_J_STABLE)
-#define IS_SYNCED(st) (((st) & 0xF0) >= BS_ST_SYNCED)
+#define IS_BIG_WRITE(st) (st >= ST_D_SUBMITTED && st <= ST_D_STABLE)
-#define IS_JOURNAL(st) (((st) & 0x0F) == BS_ST_SMALL_WRITE)
+#define IS_DELETE(st) (st >= ST_DEL_SUBMITTED && st <= ST_DEL_STABLE)
-#define IS_BIG_WRITE(st) (((st) & 0x0F) == BS_ST_BIG_WRITE)
+#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 IS_DELETE(st) (((st) & 0x0F) == BS_ST_DELETE)
 #define BS_SUBMIT_CHECK_SQES(n) \
    if (ringloop->space_left() < (n))\
    {\
        /* Pause until there are more requests available */\
        PRIV(op)->wait_for = WAIT_SQE;\
        return 0;\
    }
 #define BS_SUBMIT_GET_SQE(sqe, data) \
    BS_SUBMIT_GET_ONLY_SQE(sqe); \
@ -86,25 +78,7 @@
 #include "blockstore_journal.h"
-// "VITAstor"
+// 24 bytes + block bitmap per "clean" entry on disk with fixed metadata tables
 #define BLOCKSTORE_META_MAGIC 0x726F747341544956l
 #define BLOCKSTORE_META_VERSION 1
 // metadata header (superblock)
 // FIXME: After adding the OSD superblock, add a key to metadata
 // and journal headers to check if they belong to the same OSD
 struct __attribute__((__packed__)) blockstore_meta_header_t
 {
    uint64_t zero;
    uint64_t magic;
    uint64_t version;
    uint32_t meta_block_size;
    uint32_t data_block_size;
    uint32_t bitmap_granularity;
 };
 // 32 bytes = 24 bytes + block bitmap (4 bytes by default) + external attributes (also bitmap, 4 bytes by default)
 // per "clean" entry on disk with fixed metadata tables
 // FIXME: maybe add crc32's to metadata
 struct __attribute__((__packed__)) clean_disk_entry
 {
@ -120,7 +94,7 @@ struct __attribute__((__packed__)) clean_entry
    uint64_t location;
 };
-// 64 = 24 + 40 bytes per dirty entry in memory (obj_ver_id => dirty_entry)
+// 56 = 24 + 32 bytes per dirty entry in memory (obj_ver_id => dirty_entry)
 struct __attribute__((__packed__)) dirty_entry
 {
    uint32_t state;
@ -129,7 +103,6 @@ struct __attribute__((__packed__)) dirty_entry
    uint32_t offset;   // data offset within object (stripe)
    uint32_t len;      // data length
    uint64_t journal_sector; // journal sector used for this entry
    void* bitmap;   // either external bitmap itself when it fits, or a pointer to it when it doesn't
 };
 // - Sync must be submitted after previous writes/deletes (not before!)
@ -151,6 +124,8 @@ 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
@ -164,7 +139,7 @@ struct fulfill_read_t
 };
 #define PRIV(op) ((blockstore_op_private_t*)(op)->private_data)
-#define FINISH_OP(op) PRIV(op)->~blockstore_op_private_t(); std::function<void (blockstore_op_t*)>(op->callback)(op)
+#define FINISH_OP(op) PRIV(op)->~blockstore_op_private_t(); op->callback(op)
 struct blockstore_op_private_t
 {
@ -172,29 +147,23 @@ 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
-    int min_flushed_journal_sector, max_flushed_journal_sector;
+    uint64_t min_used_journal_sector, max_used_journal_sector;
    // Write
    struct iovec iov_zerofill[3];
    // Warning: must not have a default value here because it's written to before calling constructor in blockstore_write.cpp O_o
    uint64_t real_version;
    timespec tv_begin;
    // Sync
    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;
 };
 // 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"
@ -208,46 +177,34 @@ class blockstore_impl_t
    uint32_t block_size;
    uint64_t meta_offset;
    uint64_t data_offset;
-    uint64_t cfg_journal_size, cfg_data_size;
+    uint64_t cfg_journal_size;
    // Required write alignment and journal/metadata/data areas' location alignment
-    uint32_t disk_alignment = 4096;
+    uint32_t disk_alignment = 512;
    // Journal block size - minimum_io_size of the journal device is the best choice
-    uint64_t journal_block_size = 4096;
+    uint64_t journal_block_size = 512;
    // Metadata block size - minimum_io_size of the metadata device is the best choice
-    uint64_t meta_block_size = 4096;
+    uint64_t meta_block_size = 512;
    // 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"
-    // Suitable only for server SSDs with capacitors, requires disabled data and journal fsyncs
+    // FIXME Not implemented yet
-    int immediate_commit = IMMEDIATE_NONE;
+    bool immediate_commit = false;
    bool inmemory_meta = false;
-    // Maximum and minimum flusher count
+    int flusher_count;
    unsigned max_flusher_count, min_flusher_count;
    // Maximum queue depth
    unsigned max_write_iodepth = 128;
    // Enable small (journaled) write throttling, useful for the SSD+HDD case
    bool throttle_small_writes = false;
    // Target data device iops, bandwidth and parallelism for throttling (100/100/1 is the default for HDD)
    int throttle_target_iops = 100;
    int throttle_target_mbs = 100;
    int throttle_target_parallelism = 1;
    // Minimum difference in microseconds between target and real execution times to throttle the response
    int throttle_threshold_us = 50;
    /******* END OF OPTIONS *******/
    struct ring_consumer_t ring_consumer;
-    blockstore_clean_db_t clean_db;
+    // Another option is https://github.com/algorithm-ninja/cpp-btree
    spp::sparse_hash_map<object_id, clean_entry> clean_db;
    uint8_t *clean_bitmap = NULL;
    blockstore_dirty_db_t dirty_db;
-    std::vector<blockstore_op_t*> submit_queue;
+    std::list<blockstore_op_t*> submit_queue; // FIXME: funny thing is that vector is better here
    std::vector<obj_ver_id> unsynced_big_writes, unsynced_small_writes;
-    int unsynced_big_write_count = 0;
+    std::list<blockstore_op_t*> in_progress_syncs; // ...and probably here, too
    allocator *data_alloc = NULL;
    uint8_t *zero_object;
@ -259,17 +216,14 @@ class blockstore_impl_t
    int data_fd;
    uint64_t meta_size, meta_area, meta_len;
    uint64_t data_size, data_len;
    uint64_t data_device_sect, meta_device_sect, journal_device_sect;
    void *metadata_buffer = NULL;
    struct journal_t journal;
    journal_flusher_t *flusher;
    int write_iodepth = 0;
    bool live = false, queue_stall = false;
    ring_loop_t *ringloop;
    timerfd_manager_t *tfd;
    bool stop_sync_submitted;
@ -289,11 +243,6 @@ class blockstore_impl_t
    void open_data();
    void open_meta();
    void open_journal();
    uint8_t* get_clean_entry_bitmap(uint64_t block_loc, int offset);
    // Journaling
    void prepare_journal_sector_write(int sector, blockstore_op_t *op);
    void handle_journal_write(ring_data_t *data, uint64_t flush_id);
    // Asynchronous init
    int initialized;
@ -313,27 +262,27 @@ class blockstore_impl_t
    // Write
    bool enqueue_write(blockstore_op_t *op);
    void cancel_all_writes(blockstore_op_t *op, blockstore_dirty_db_t::iterator dirty_it, int retval);
    int dequeue_write(blockstore_op_t *op);
    int dequeue_del(blockstore_op_t *op);
-    int continue_write(blockstore_op_t *op);
+    void ack_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);
    // Sync
-    int continue_sync(blockstore_op_t *op, bool queue_has_in_progress_sync);
+    int dequeue_sync(blockstore_op_t *op);
-    void ack_sync(blockstore_op_t *op);
+    void handle_sync_event(ring_data_t *data, blockstore_op_t *op);
    int continue_sync(blockstore_op_t *op);
    void ack_one_sync(blockstore_op_t *op);
    int ack_sync(blockstore_op_t *op);
    // Stabilize
    int dequeue_stable(blockstore_op_t *op);
-    int continue_stable(blockstore_op_t *op);
+    void handle_stable_event(ring_data_t *data, blockstore_op_t *op);
    void mark_stable(const obj_ver_id & ov, bool forget_dirty = false);
    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 handle_rollback_event(ring_data_t *data, blockstore_op_t *op);
    void mark_rolled_back(const obj_ver_id & ov);
    void erase_dirty(blockstore_dirty_db_t::iterator dirty_start, blockstore_dirty_db_t::iterator dirty_end, uint64_t clean_loc);
    // List
@ -341,7 +290,7 @@ class blockstore_impl_t
 public:
-    blockstore_impl_t(blockstore_config_t & config, ring_loop_t *ringloop, timerfd_manager_t *tfd);
+    blockstore_impl_t(blockstore_config_t & config, ring_loop_t *ringloop);
    ~blockstore_impl_t();
    // Event loop
@ -360,23 +309,12 @@ public:
    bool is_stalled();
    // Submission
-    void enqueue_op(blockstore_op_t *op);
+    void enqueue_op(blockstore_op_t *op, bool first = false);
    // Simplified synchronous operation: get object bitmap & current version
    int read_bitmap(object_id oid, uint64_t target_version, void *bitmap, uint64_t *result_version = NULL);
    // Unstable writes are added here (map of object_id -> version)
    std::unordered_map<object_id, uint64_t> unstable_writes;
    // Space usage statistics
    std::map<uint64_t, uint64_t> inode_space_stats;
    // Print diagnostics to stdout
    void dump_diagnostics();
    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; }
    inline uint32_t get_bitmap_granularity() { return disk_alignment; }
    inline uint64_t get_journal_size() { return journal.len; }
 };
--- a/src/blockstore_init.cpp
+++ b/src/blockstore_init.cpp
@ -1,22 +1,5 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #include "blockstore_impl.h"
 #define GET_SQE() \
    sqe = bs->get_sqe();\
    if (!sqe)\
        throw std::runtime_error("io_uring is full during initialization");\
    data = ((ring_data_t*)sqe->user_data)
 static bool iszero(uint64_t *buf, int len)
 {
    for (int i = 0; i < len; i++)
        if (buf[i] != 0)
            return false;
    return true;
 }
 blockstore_init_meta::blockstore_init_meta(blockstore_impl_t *bs)
 {
    this->bs = bs;
@ -24,7 +7,7 @@ blockstore_init_meta::blockstore_init_meta(blockstore_impl_t *bs)
 void blockstore_init_meta::handle_event(ring_data_t *data)
 {
-    if (data->res < 0)
+    if (data->res <= 0)
    {
        throw std::runtime_error(
            std::string("read metadata failed at offset ") + std::to_string(metadata_read) +
@ -42,12 +25,6 @@ int blockstore_init_meta::loop()
 {
    if (wait_state == 1)
        goto resume_1;
    else if (wait_state == 2)
        goto resume_2;
    else if (wait_state == 3)
        goto resume_3;
    else if (wait_state == 4)
        goto resume_4;
    printf("Reading blockstore metadata\n");
    if (bs->inmemory_meta)
        metadata_buffer = bs->metadata_buffer;
@ -55,98 +32,22 @@ int blockstore_init_meta::loop()
        metadata_buffer = memalign(MEM_ALIGNMENT, 2*bs->metadata_buf_size);
    if (!metadata_buffer)
        throw std::runtime_error("Failed to allocate metadata read buffer");
-    // Read superblock
+    while (1)
-    GET_SQE();
+    {
    data->iov = { metadata_buffer, bs->meta_block_size };
    data->callback = [this](ring_data_t *data) { handle_event(data); };
    my_uring_prep_readv(sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset);
    bs->ringloop->submit();
    submitted = 1;
    resume_1:
        if (submitted)
        {
            wait_state = 1;
            return 1;
        }
    if (iszero((uint64_t*)metadata_buffer, bs->meta_block_size / sizeof(uint64_t)))
    {
        {
            blockstore_meta_header_t *hdr = (blockstore_meta_header_t *)metadata_buffer;
            hdr->zero = 0;
            hdr->magic = BLOCKSTORE_META_MAGIC;
            hdr->version = BLOCKSTORE_META_VERSION;
            hdr->meta_block_size = bs->meta_block_size;
            hdr->data_block_size = bs->block_size;
            hdr->bitmap_granularity = bs->bitmap_granularity;
        }
        if (bs->readonly)
        {
            printf("Skipping metadata initialization because blockstore is readonly\n");
        }
        else
        {
            printf("Initializing metadata area\n");
            GET_SQE();
            data->iov = (struct iovec){ metadata_buffer, bs->meta_block_size };
            data->callback = [this](ring_data_t *data) { handle_event(data); };
            my_uring_prep_writev(sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset);
            bs->ringloop->submit();
            submitted = 1;
        resume_3:
            if (submitted > 0)
            {
                wait_state = 3;
                return 1;
            }
            zero_on_init = true;
        }
    }
    else
    {
        blockstore_meta_header_t *hdr = (blockstore_meta_header_t *)metadata_buffer;
        if (hdr->zero != 0 ||
            hdr->magic != BLOCKSTORE_META_MAGIC ||
            hdr->version != BLOCKSTORE_META_VERSION)
        {
            printf(
                "Metadata is corrupt or old version.\n"
                " If this is a new OSD please zero out the metadata area before starting it.\n"
                " If you need to upgrade from 0.5.x please request it via the issue tracker.\n"
            );
            exit(1);
        }
        if (hdr->meta_block_size != bs->meta_block_size ||
            hdr->data_block_size != bs->block_size ||
            hdr->bitmap_granularity != bs->bitmap_granularity)
        {
            printf(
                "Configuration stored in metadata superblock"
                " (meta_block_size=%u, data_block_size=%u, bitmap_granularity=%u)"
                " differs from OSD configuration (%lu/%u/%lu).\n",
                hdr->meta_block_size, hdr->data_block_size, hdr->bitmap_granularity,
                bs->meta_block_size, bs->block_size, bs->bitmap_granularity
            );
            exit(1);
        }
    }
    // Skip superblock
    bs->meta_offset += bs->meta_block_size;
    prev_done = 0;
    done_len = 0;
    done_pos = 0;
    metadata_read = 0;
    // Read the rest of the metadata
    while (1)
    {
    resume_2:
        if (submitted)
        {
            wait_state = 2;
            return 1;
        }
        if (metadata_read < bs->meta_len)
        {
-            GET_SQE();
+            sqe = bs->get_sqe();
            if (!sqe)
            {
                throw std::runtime_error("io_uring is full while trying to read metadata");
            }
            data = ((ring_data_t*)sqe->user_data);
            data->iov = {
                metadata_buffer + (bs->inmemory_meta
                    ? metadata_read
@ -154,14 +55,7 @@ resume_1:
                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); };
            if (!zero_on_init)
            my_uring_prep_readv(sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + metadata_read);
            else
            {
                // Fill metadata with zeroes
                memset(data->iov.iov_base, 0, data->iov.iov_len);
                my_uring_prep_writev(sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + metadata_read);
            }
            bs->ringloop->submit();
            submitted = (prev == 1 ? 2 : 1);
            prev = submitted;
@ -193,21 +87,6 @@ resume_1:
        free(metadata_buffer);
        metadata_buffer = NULL;
    }
    if (zero_on_init && !bs->disable_meta_fsync)
    {
        GET_SQE();
        my_uring_prep_fsync(sqe, bs->meta_fd, IORING_FSYNC_DATASYNC);
        data->iov = { 0 };
        data->callback = [this](ring_data_t *data) { handle_event(data); };
        submitted = 1;
        bs->ringloop->submit();
    resume_4:
        if (submitted > 0)
        {
            wait_state = 4;
            return 1;
        }
    }
    return 0;
 }
@ -218,7 +97,7 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
        clean_disk_entry *entry = (clean_disk_entry*)(entries + i*bs->clean_entry_size);
        if (!bs->inmemory_meta && bs->clean_entry_bitmap_size)
        {
-            memcpy(bs->clean_bitmap + (done_cnt+i)*2*bs->clean_entry_bitmap_size, &entry->bitmap, 2*bs->clean_entry_bitmap_size);
+            memcpy(bs->clean_bitmap + (done_cnt+i)*bs->clean_entry_bitmap_size, &entry->bitmap, bs->clean_entry_bitmap_size);
        }
        if (entry->oid.inode > 0)
        {
@ -229,20 +108,13 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
                {
                    // free the previous block
 #ifdef BLOCKSTORE_DEBUG
-                    printf("Free block %lu from %lx:%lx v%lu (new location is %lu)\n",
+                    printf("Free block %lu\n", clean_it->second.location >> bs->block_order);
                        clean_it->second.location >> block_order,
                        clean_it->first.inode, clean_it->first.stripe, clean_it->second.version,
                        done_cnt+i);
 #endif
                    bs->data_alloc->set(clean_it->second.location >> block_order, false);
                }
                else
                {
                    bs->inode_space_stats[entry->oid.inode] += bs->block_size;
                }
                entries_loaded++;
 #ifdef BLOCKSTORE_DEBUG
-                printf("Allocate block (clean entry) %lu: %lx:%lx v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
+                printf("Allocate block (clean entry) %lu: %lu:%lu 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){
@ -253,7 +125,7 @@ void blockstore_init_meta::handle_entries(void* entries, unsigned count, int blo
            else
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf("Old clean entry %lu: %lx:%lx v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
+                printf("Old clean entry %lu: %lu:%lu v%lu\n", done_cnt+i, entry->oid.inode, entry->oid.stripe, entry->version);
 #endif
            }
        }
@ -274,6 +146,14 @@ blockstore_init_journal::blockstore_init_journal(blockstore_impl_t *bs)
    };
 }
 bool iszero(uint64_t *buf, int len)
 {
    for (int i = 0; i < len; i++)
        if (buf[i] != 0)
            return false;
    return true;
 }
 void blockstore_init_journal::handle_event(ring_data_t *data1)
 {
    if (data1->res <= 0)
@ -298,6 +178,12 @@ void blockstore_init_journal::handle_event(ring_data_t *data1)
    submitted_buf = NULL;
 }
 #define GET_SQE() \
    sqe = bs->get_sqe();\
    if (!sqe)\
        throw std::runtime_error("io_uring is full while trying to read journal");\
    data = ((ring_data_t*)sqe->user_data)
 int blockstore_init_journal::loop()
 {
    if (wait_state == 1)
@ -316,7 +202,11 @@ int blockstore_init_journal::loop()
        goto resume_7;
    printf("Reading blockstore journal\n");
    if (!bs->journal.inmemory)
-        submitted_buf = memalign_or_die(MEM_ALIGNMENT, 2*bs->journal.block_size);
+    {
        submitted_buf = memalign(MEM_ALIGNMENT, 2*bs->journal.block_size);
        if (!submitted_buf)
            throw std::bad_alloc();
    }
    else
        submitted_buf = bs->journal.buffer;
    // Read first block of the journal
@ -335,7 +225,7 @@ resume_1:
        wait_state = 1;
        return 1;
    }
-    if (iszero((uint64_t*)submitted_buf, bs->journal.block_size / sizeof(uint64_t)))
+    if (iszero((uint64_t*)submitted_buf, 3))
    {
        // Journal is empty
        // FIXME handle this wrapping to journal_block_size better (maybe)
@ -350,7 +240,6 @@ resume_1:
            .size = sizeof(journal_entry_start),
            .reserved = 0,
            .journal_start = bs->journal.block_size,
            .version = JOURNAL_VERSION,
        };
        ((journal_entry_start*)submitted_buf)->crc32 = je_crc32((journal_entry*)submitted_buf);
        if (bs->readonly)
@ -401,21 +290,11 @@ resume_1:
        je_start = (journal_entry_start*)submitted_buf;
        if (je_start->magic != JOURNAL_MAGIC ||
            je_start->type != JE_START ||
-            je_crc32((journal_entry*)je_start) != je_start->crc32 ||
+            je_start->size != sizeof(journal_entry_start) ||
-            je_start->size != sizeof(journal_entry_start) && je_start->size != JE_START_LEGACY_SIZE)
+            je_crc32((journal_entry*)je_start) != je_start->crc32)
        {
            // Entry is corrupt
-            fprintf(stderr, "First entry of the journal is corrupt\n");
+            throw std::runtime_error("first entry of the journal is corrupt");
            exit(1);
        }
        if (je_start->size == JE_START_LEGACY_SIZE || je_start->version != JOURNAL_VERSION)
        {
            fprintf(
                stderr, "The code only supports journal version %d, but it is %lu on disk."
                    " Please use the previous version to flush the journal before upgrading OSD\n",
                JOURNAL_VERSION, je_start->size == JE_START_LEGACY_SIZE ? 0 : je_start->version
            );
            exit(1);
        }
        next_free = journal_pos = bs->journal.used_start = je_start->journal_start;
        if (!bs->journal.inmemory)
@ -438,7 +317,7 @@ resume_1:
                if (journal_pos < bs->journal.used_start)
                    end = bs->journal.used_start;
                if (!bs->journal.inmemory)
-                    submitted_buf = memalign_or_die(MEM_ALIGNMENT, JOURNAL_BUFFER_SIZE);
+                    submitted_buf = memalign(MEM_ALIGNMENT, JOURNAL_BUFFER_SIZE);
                else
                    submitted_buf = bs->journal.buffer + journal_pos;
                data->iov = {
@ -521,22 +400,10 @@ resume_1:
            }
        }
    }
-    for (auto ov: double_allocs)
+    // Trim journal on start so we don't stall when all entries are older
-    {
+    bs->journal.trim();
        auto dirty_it = bs->dirty_db.find(ov);
        if (dirty_it != bs->dirty_db.end() &&
            IS_BIG_WRITE(dirty_it->second.state) &&
            dirty_it->second.location == UINT64_MAX)
        {
            printf("Fatal error (bug): %lx:%lx v%lu big_write journal_entry was allocated over another object\n",
                dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version);
            exit(1);
        }
    }
    bs->flusher->mark_trim_possible();
    bs->journal.dirty_start = bs->journal.next_free;
    printf(
-        "Journal entries loaded: %lu, free journal space: %lu bytes (%08lx..%08lx is used), free blocks: %lu / %lu\n",
+        "Journal entries loaded: %lu, free journal space: %lu bytes (%lu..%lu 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)
@ -572,7 +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_MIN || je->type > JE_MAX || started && je->crc32_prev != crc32_last)
+                je->type < JE_SMALL_WRITE || je->type > JE_DELETE || started && je->crc32_prev != crc32_last)
            {
                if (pos == 0)
                {
@ -586,15 +453,10 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                    break;
                }
            }
-            if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
+            if (je->type == JE_SMALL_WRITE)
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf(
+                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);
                    "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;
@ -612,7 +474,7 @@ 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 (%08lx) != stored journal data offset (%08lx)", location, je->small_write.data_offset);
+                    snprintf(err, 1024, "BUG: calculated journal data offset (%lu) != stored journal data offset (%lu)", location, je->small_write.data_offset);
                    throw std::runtime_error(err);
                }
                uint32_t data_crc32 = 0;
@ -647,9 +509,7 @@ 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;
@ -658,83 +518,33 @@ 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->small_write.version)
+                    clean_it->second.version < je->big_write.version)
                {
                    obj_ver_id ov = {
                        .oid = je->small_write.oid,
                        .version = je->small_write.version,
                    };
                    void *bmp = NULL;
                    void *bmp_from = (void*)je + sizeof(journal_entry_small_write);
                    if (bs->clean_entry_bitmap_size <= sizeof(void*))
                    {
                        memcpy(&bmp, bmp_from, bs->clean_entry_bitmap_size);
                    }
                    else
                    {
                        // FIXME Using large blockstore objects will result in a lot of small
                        // allocations for entry bitmaps. This can only be fixed by using
                        // a patched map with dynamic entry size, but not the btree_map,
                        // because it doesn't keep iterators valid all the time.
                        bmp = malloc_or_die(bs->clean_entry_bitmap_size);
                        memcpy(bmp, bmp_from, bs->clean_entry_bitmap_size);
                    }
                    bs->dirty_db.emplace(ov, (dirty_entry){
-                        .state = (BS_ST_SMALL_WRITE | BS_ST_SYNCED),
+                        .state = ST_J_SYNCED,
                        .flags = 0,
                        .location = location,
                        .offset = je->small_write.offset,
                        .len = je->small_write.len,
                        .journal_sector = proc_pos,
                        .bitmap = bmp,
                    });
                    bs->journal.used_sectors[proc_pos]++;
 #ifdef BLOCKSTORE_DEBUG
-                    printf(
+                    printf("journal offset %lu is used by %lu:%lu v%lu\n", proc_pos, ov.oid.inode, ov.oid.stripe, ov.version);
                        "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, true);
                }
            }
-            }
+            else if (je->type == JE_BIG_WRITE)
            else if (je->type == JE_BIG_WRITE || je->type == JE_BIG_WRITE_INSTANT)
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf(
+                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);
                    "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 >> bs->block_order
                );
 #endif
                auto dirty_it = bs->dirty_db.upper_bound((obj_ver_id){
                    .oid = je->big_write.oid,
                    .version = UINT64_MAX,
                });
                if (dirty_it != bs->dirty_db.begin() && bs->dirty_db.size() > 0)
                {
                    dirty_it--;
                    if (dirty_it->first.oid == je->big_write.oid &&
                        dirty_it->first.version >= je->big_write.version &&
                        (dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_DELETE)
                    {
                        // It is allowed to overwrite a deleted object with a
                        // version number smaller than deletion version number,
                        // because the presence of a BIG_WRITE entry means that
                        // its data and metadata are already flushed.
                        // We don't know if newer versions are flushed, but
                        // the previous delete definitely is.
                        // So we forget previous dirty entries, but retain the clean one.
                        // This feature is required for writes happening shortly
                        // after deletes.
                        erase_dirty_object(dirty_it);
                    }
                }
                auto clean_it = bs->clean_db.find(je->big_write.oid);
                if (clean_it == bs->clean_db.end() ||
                    clean_it->second.version < je->big_write.version)
@ -744,121 +554,124 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                        .oid = je->big_write.oid,
                        .version = je->big_write.version,
                    };
-                    void *bmp = NULL;
+                    bs->dirty_db.emplace(ov, (dirty_entry){
-                    void *bmp_from = (void*)je + sizeof(journal_entry_big_write);
+                        .state = ST_D_META_SYNCED,
                    if (bs->clean_entry_bitmap_size <= sizeof(void*))
                    {
                        memcpy(&bmp, bmp_from, bs->clean_entry_bitmap_size);
                    }
                    else
                    {
                        // FIXME Using large blockstore objects will result in a lot of small
                        // allocations for entry bitmaps. This can only be fixed by using
                        // a patched map with dynamic entry size, but not the btree_map,
                        // because it doesn't keep iterators valid all the time.
                        bmp = malloc_or_die(bs->clean_entry_bitmap_size);
                        memcpy(bmp, bmp_from, bs->clean_entry_bitmap_size);
                    }
                    auto dirty_it = bs->dirty_db.emplace(ov, (dirty_entry){
                        .state = (BS_ST_BIG_WRITE | BS_ST_SYNCED),
                        .flags = 0,
                        .location = je->big_write.location,
                        .offset = je->big_write.offset,
                        .len = je->big_write.len,
                        .journal_sector = proc_pos,
-                        .bitmap = bmp,
+                    });
                    }).first;
                    if (bs->data_alloc->get(je->big_write.location >> bs->block_order))
                    {
                        // This is probably a big_write that's already flushed and freed, but it may
                        // also indicate a bug. So we remember such entries and recheck them afterwards.
                        // If it's not a bug they won't be present after reading the whole journal.
                        dirty_it->second.location = UINT64_MAX;
                        double_allocs.push_back(ov);
                    }
                    else
                    {
 #ifdef BLOCKSTORE_DEBUG
-                        printf(
+                    printf("Allocate block %lu\n", je->big_write.location >> bs->block_order);
                            "Allocate block (journal) %lu: %lx:%lx v%lu\n",
                            je->big_write.location >> bs->block_order,
                            ov.oid.inode, ov.oid.stripe, ov.version
                        );
 #endif
                    bs->data_alloc->set(je->big_write.location >> bs->block_order, true);
                    }
                    bs->journal.used_sectors[proc_pos]++;
 #ifdef BLOCKSTORE_DEBUG
                    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_BIG_WRITE_INSTANT)
                    {
                        bs->mark_stable(ov, true);
                    }
                }
            }
            else if (je->type == JE_STABLE)
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_stable oid=%lx:%lx ver=%lu\n", je->stable.oid.inode, je->stable.oid.stripe, je->stable.version);
+                printf("je_stable oid=%lu:%lu 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,
                };
-                bs->mark_stable(ov, true);
+                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);
                }
            }
            else if (je->type == JE_ROLLBACK)
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_rollback oid=%lx:%lx ver=%lu\n", je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version);
+                printf("je_rollback oid=%lu:%lu ver=%lu\n", je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version);
 #endif
                // rollback dirty writes of <oid> up to <version>
-                obj_ver_id ov = {
+                auto it = bs->dirty_db.lower_bound((obj_ver_id){
                    .oid = je->rollback.oid,
-                    .version = je->rollback.version,
+                    .version = UINT64_MAX,
-                };
+                });
-                bs->mark_rolled_back(ov);
+                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;
                    }
                }
            }
            else if (je->type == JE_DELETE)
            {
 #ifdef BLOCKSTORE_DEBUG
-                printf("je_delete oid=%lx:%lx ver=%lu\n", je->del.oid.inode, je->del.oid.stripe, je->del.version);
+                printf("je_delete oid=%lu:%lu ver=%lu\n", je->del.oid.inode, je->del.oid.stripe, je->del.version);
 #endif
                bool dirty_exists = false;
                auto dirty_it = bs->dirty_db.upper_bound((obj_ver_id){
                    .oid = je->del.oid,
                    .version = UINT64_MAX,
                });
                if (dirty_it != bs->dirty_db.begin())
                {
                    dirty_it--;
                    dirty_exists = dirty_it->first.oid == je->del.oid;
                }
                auto clean_it = bs->clean_db.find(je->del.oid);
                bool clean_exists = (clean_it != bs->clean_db.end() &&
                    clean_it->second.version < je->del.version);
                if (!clean_exists && dirty_exists)
                {
                    // Clean entry doesn't exist. This means that the delete is already flushed.
                    // So we must not flush this object anymore.
                    erase_dirty_object(dirty_it);
                }
                else if (clean_exists || dirty_exists)
                {
                // 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),
+                    .state = ST_DEL_SYNCED,
                    .flags = 0,
                    .location = 0,
                    .offset = 0,
@ -866,11 +679,6 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
                    .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, true);
                }
                // Ignore delete if neither preceding dirty entries nor the clean one are present
            }
            started = true;
            pos += je->size;
@ -881,35 +689,3 @@ int blockstore_init_journal::handle_journal_part(void *buf, uint64_t done_pos, u
    bs->journal.next_free = next_free;
    return 1;
 }
 void blockstore_init_journal::erase_dirty_object(blockstore_dirty_db_t::iterator dirty_it)
 {
    auto oid = dirty_it->first.oid;
    bool exists = !IS_DELETE(dirty_it->second.state);
    auto dirty_end = dirty_it;
    dirty_end++;
    while (1)
    {
        if (dirty_it == bs->dirty_db.begin())
        {
            break;
        }
        dirty_it--;
        if (dirty_it->first.oid != oid)
        {
            dirty_it++;
            break;
        }
    }
    auto clean_it = bs->clean_db.find(oid);
    uint64_t clean_loc = clean_it != bs->clean_db.end()
        ? clean_it->second.location : UINT64_MAX;
    if (exists && clean_loc == UINT64_MAX)
    {
        bs->inode_space_stats[oid.inode] -= bs->block_size;
    }
    bs->erase_dirty(dirty_it, dirty_end, clean_loc);
    // Remove it from the flusher's queue, too
    // Otherwise it may end up referring to a small unstable write after reading the rest of the journal
    bs->flusher->remove_flush(oid);
 }
--- a/src/blockstore_init.h
+++ b/src/blockstore_init.h
@ -1,13 +1,9 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #pragma once
 class blockstore_init_meta
 {
    blockstore_impl_t *bs;
    int wait_state = 0, wait_count = 0;
    bool zero_on_init = false;
    void *metadata_buffer = NULL;
    uint64_t metadata_read = 0;
    int prev = 0, prev_done = 0, done_len = 0, submitted = 0;
@ -37,7 +33,6 @@ class blockstore_init_journal
    bool started = false;
    uint64_t next_free;
    std::vector<bs_init_journal_done> done;
    std::vector<obj_ver_id> double_allocs;
    uint64_t journal_pos = 0;
    uint64_t continue_pos = 0;
    void *init_write_buf = NULL;
@ -50,7 +45,6 @@ class blockstore_init_journal
    std::function<void(ring_data_t*)> simple_callback;
    int handle_journal_part(void *buf, uint64_t done_pos, uint64_t len);
    void handle_event(ring_data_t *data);
    void erase_dirty_object(blockstore_dirty_db_t::iterator dirty_it);
 public:
    blockstore_init_journal(blockstore_impl_t* bs);
    int loop();
--- a/blockstore_journal.cpp
+++ b/blockstore_journal.cpp
@ -0,0 +1,186 @@
 #include "blockstore_impl.h"
 blockstore_journal_check_t::blockstore_journal_check_t(blockstore_impl_t *bs)
 {
    this->bs = bs;
    sectors_required = 0;
    next_pos = bs->journal.next_free;
    next_sector = bs->journal.cur_sector;
    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)
 {
    while (1)
    {
        int fits = (bs->journal.block_size - next_in_pos) / size;
        if (fits > 0)
        {
            required -= fits;
            next_in_pos += fits * size;
            sectors_required++;
        }
        else if (bs->journal.sector_info[next_sector].dirty)
        {
            // sectors_required is more like "sectors to write"
            sectors_required++;
        }
        if (required <= 0)
        {
            break;
        }
        next_pos = next_pos + bs->journal.block_size;
        if (next_pos >= bs->journal.len)
        {
            next_pos = bs->journal.block_size;
            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 (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
            PRIV(op)->wait_for = WAIT_JOURNAL_BUFFER;
            return 0;
        }
    }
    if (data_after > 0)
    {
        next_pos = next_pos + data_after;
        if (next_pos > bs->journal.len)
        {
            next_pos = bs->journal.block_size + data_after;
            right_dir = false;
        }
    }
    if (!right_dir && next_pos >= bs->journal.used_start-bs->journal.block_size)
    {
        // No space in the journal. Wait until used_start changes.
        printf(
            "Ran out of journal space (free space: %lu bytes)\n",
            (bs->journal.next_free >= bs->journal.used_start
                ? bs->journal.len-bs->journal.block_size - (bs->journal.next_free-bs->journal.used_start)
                : bs->journal.used_start - bs->journal.next_free)
        );
        PRIV(op)->wait_for = WAIT_JOURNAL;
        bs->flusher->force_start();
        PRIV(op)->wait_detail = bs->journal.used_start;
        return 0;
    }
    return 1;
 }
 journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type, uint32_t size)
 {
    if (journal.block_size - journal.in_sector_pos < size)
    {
        assert(!journal.sector_info[journal.cur_sector].dirty);
        // Move to the next journal sector
        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);
        }
        journal.sector_info[journal.cur_sector].offset = journal.next_free;
        journal.in_sector_pos = 0;
        journal.next_free = (journal.next_free+journal.block_size) < journal.len ? journal.next_free + journal.block_size : journal.block_size;
        memset(journal.inmemory
            ? journal.buffer + journal.sector_info[journal.cur_sector].offset
            : journal.sector_buf + journal.block_size*journal.cur_sector, 0, journal.block_size);
    }
    journal_entry *je = (struct journal_entry*)(
        (journal.inmemory
            ? journal.buffer + journal.sector_info[journal.cur_sector].offset
            : journal.sector_buf + journal.block_size*journal.cur_sector) + journal.in_sector_pos
    );
    journal.in_sector_pos += size;
    je->magic = JOURNAL_MAGIC;
    je->type = type;
    je->size = size;
    je->crc32_prev = journal.crc32_last;
    journal.sector_info[journal.cur_sector].dirty = true;
    return je;
 }
 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].usage_count++;
    ring_data_t *data = ((ring_data_t*)sqe->user_data);
    data->iov = (struct iovec){
        (journal.inmemory
            ? journal.buffer + journal.sector_info[cur_sector].offset
            : journal.sector_buf + journal.block_size*cur_sector),
        journal.block_size
    };
    data->callback = cb;
    my_uring_prep_writev(
        sqe, journal.fd, &data->iov, 1, journal.offset + journal.sector_info[cur_sector].offset
    );
 }
 journal_t::~journal_t()
 {
    if (sector_buf)
        free(sector_buf);
    if (sector_info)
        free(sector_info);
    if (buffer)
        free(buffer);
    sector_buf = NULL;
    sector_info = NULL;
    buffer = NULL;
 }
 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,
        journal_used_it == used_sectors.end() ? 0 : journal_used_it->first,
        journal_used_it == used_sectors.end() ? 0 : journal_used_it->second
    );
 #endif
    if (journal_used_it == used_sectors.end())
    {
        // Journal is cleared to its end, restart from the beginning
        journal_used_it = used_sectors.begin();
        if (journal_used_it == used_sectors.end())
        {
            // Journal is empty
            used_start = next_free;
        }
        else
        {
            used_start = journal_used_it->first;
            // next_free does not need updating here
        }
    }
    else if (journal_used_it->first > used_start)
    {
        // Journal is cleared up to <journal_used_it>
        used_start = journal_used_it->first;
    }
    else
    {
        // Can't trim journal
        return false;
    }
 #ifdef BLOCKSTORE_DEBUG
    printf("Journal trimmed to %lu (next_free=%lu)\n", used_start, next_free);
 #endif
    return true;
 }
--- a/src/blockstore_journal.h
+++ b/src/blockstore_journal.h
@ -1,34 +1,23 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #pragma once
 #include "crc32c.h"
 #include <set>
 #define MIN_JOURNAL_SIZE 4*1024*1024
 #define JOURNAL_MAGIC 0x4A33
 #define JOURNAL_VERSION 1
 #define JOURNAL_BUFFER_SIZE 4*1024*1024
 // We reserve some extra space for future stabilize requests during writes
 // FIXME: This value should be dynamic i.e. Blockstore ideally shouldn't allow
 // writing more than can be stabilized afterwards
 #define JOURNAL_STABILIZE_RESERVATION 65536
 // 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
@ -39,9 +28,7 @@ struct __attribute__((__packed__)) journal_entry_start
    uint32_t size;
    uint32_t reserved;
    uint64_t journal_start;
    uint64_t version;
 };
 #define JE_START_LEGACY_SIZE 24
 struct __attribute__((__packed__)) journal_entry_small_write
 {
@ -58,9 +45,6 @@ struct __attribute__((__packed__)) journal_entry_small_write
    // data_offset is its offset within journal
    uint64_t data_offset;
    uint32_t crc32_data;
    // small_write and big_write entries are followed by the "external" bitmap
    // its size is dynamic and included in journal entry's <size> field
    uint8_t bitmap[];
 };
 struct __attribute__((__packed__)) journal_entry_big_write
@ -75,9 +59,6 @@ struct __attribute__((__packed__)) journal_entry_big_write
    uint32_t offset;
    uint32_t len;
    uint64_t location;
    // small_write and big_write entries are followed by the "external" bitmap
    // its size is dynamic and included in journal entry's <size> field
    uint8_t bitmap[];
 };
 struct __attribute__((__packed__)) journal_entry_stable
@ -143,52 +124,29 @@ inline uint32_t je_crc32(journal_entry *je)
 struct journal_sector_info_t
 {
    uint64_t offset;
-    uint64_t flush_count;
+    uint64_t usage_count;
    bool written;
    bool dirty;
    uint64_t submit_id;
 };
 struct pending_journaling_t
 {
    uint64_t flush_id;
    int sector;
    blockstore_op_t *op;
 };
 inline bool operator < (const pending_journaling_t & a, const pending_journaling_t & b)
 {
    return a.flush_id < b.flush_id || a.flush_id == b.flush_id && a.op < b.op;
 }
 struct journal_t
 {
    int fd;
    uint64_t device_size;
    bool inmemory = false;
    bool flush_journal = false;
    void *buffer = NULL;
-    uint64_t block_size;
+    uint64_t block_size = 512;
    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;
    std::vector<int> submitting_sectors;
    std::set<pending_journaling_t> flushing_ops;
    uint64_t submit_id = 0;
    // Used sector map
    // May use ~ 80 MB per 1 GB of used journal space in the worst case
@ -196,20 +154,13 @@ struct journal_t
    ~journal_t();
    bool trim();
    uint64_t get_trim_pos();
    void dump_diagnostics();
    inline bool entry_fits(int size)
    {
        return !(block_size - in_sector_pos < size ||
            no_same_sector_overwrites && sector_info[cur_sector].written);
    }
 };
 struct blockstore_journal_check_t
 {
    blockstore_impl_t *bs;
    uint64_t next_pos, next_sector, next_in_pos;
-    int sectors_to_write, first_sector;
+    int sectors_required;
    bool right_dir; // writing to the end or the beginning of the ring buffer
    blockstore_journal_check_t(blockstore_impl_t *bs);
@ -217,3 +168,5 @@ struct blockstore_journal_check_t
 };
 journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type, uint32_t size);
 void prepare_journal_sector_write(journal_t & journal, int sector, io_uring_sqe *sqe, std::function<void(ring_data_t*)> cb);
--- a/src/blockstore_open.cpp
+++ b/src/blockstore_open.cpp
@ -1,7 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 #include <sys/file.h>
 #include "blockstore_impl.h"
 static uint32_t is_power_of_two(uint64_t value)
@ -38,28 +34,10 @@ 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["flush_journal"] == "true" || config["flush_journal"] == "1" || config["flush_journal"] == "yes")
    {
        // Only flush journal and exit
        journal.flush_journal = 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);
@ -67,23 +45,12 @@ 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);
    meta_block_size = strtoull(config["meta_block_size"].c_str(), NULL, 10);
    bitmap_granularity = strtoull(config["bitmap_granularity"].c_str(), NULL, 10);
-    max_flusher_count = strtoull(config["max_flusher_count"].c_str(), NULL, 10);
+    flusher_count = strtoull(config["flusher_count"].c_str(), NULL, 10);
    if (!max_flusher_count)
        max_flusher_count = strtoull(config["flusher_count"].c_str(), NULL, 10);
    min_flusher_count = strtoull(config["min_flusher_count"].c_str(), NULL, 10);
    max_write_iodepth = strtoull(config["max_write_iodepth"].c_str(), NULL, 10);
    throttle_small_writes = config["throttle_small_writes"] == "true" || config["throttle_small_writes"] == "1" || config["throttle_small_writes"] == "yes";
    throttle_target_iops = strtoull(config["throttle_target_iops"].c_str(), NULL, 10);
    throttle_target_mbs = strtoull(config["throttle_target_mbs"].c_str(), NULL, 10);
    throttle_target_parallelism = strtoull(config["throttle_target_parallelism"].c_str(), NULL, 10);
    throttle_threshold_us = strtoull(config["throttle_threshold_us"].c_str(), NULL, 10);
    // Validate
    if (!block_size)
    {
@ -93,29 +60,21 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
    {
        throw std::runtime_error("Bad block size");
    }
-    if (!max_flusher_count)
+    if (!flusher_count)
    {
-        max_flusher_count = 256;
+        flusher_count = 32;
    }
    if (!min_flusher_count || journal.flush_journal)
    {
        min_flusher_count = 1;
    }
    if (!max_write_iodepth)
    {
        max_write_iodepth = 128;
    }
    if (!disk_alignment)
    {
-        disk_alignment = 4096;
+        disk_alignment = 512;
    }
    else if (disk_alignment % MEM_ALIGNMENT)
    {
-        throw std::runtime_error("disk_alignment must be a multiple of "+std::to_string(MEM_ALIGNMENT));
+        throw std::runtime_error("disk_alingment must be a multiple of "+std::to_string(MEM_ALIGNMENT));
    }
    if (!journal_block_size)
    {
-        journal_block_size = 4096;
+        journal_block_size = 512;
    }
    else if (journal_block_size % MEM_ALIGNMENT)
    {
@ -123,7 +82,7 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
    }
    if (!meta_block_size)
    {
-        meta_block_size = 4096;
+        meta_block_size = 512;
    }
    else if (meta_block_size % MEM_ALIGNMENT)
    {
@ -135,7 +94,7 @@ void blockstore_impl_t::parse_config(blockstore_config_t & config)
    }
    if (!bitmap_granularity)
    {
-        bitmap_granularity = DEFAULT_BITMAP_GRANULARITY;
+        bitmap_granularity = 4096;
    }
    else if (bitmap_granularity % disk_alignment)
    {
@ -169,41 +128,9 @@ 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");
    }
    if (!throttle_target_iops)
    {
        throttle_target_iops = 100;
    }
    if (!throttle_target_mbs)
    {
        throttle_target_mbs = 100;
    }
    if (!throttle_target_parallelism)
    {
        throttle_target_parallelism = 1;
    }
    if (!throttle_threshold_us)
    {
        throttle_threshold_us = 50;
    }
    // init some fields
    clean_entry_bitmap_size = block_size / bitmap_granularity / 8;
-    clean_entry_size = sizeof(clean_disk_entry) + 2*clean_entry_bitmap_size;
+    clean_entry_size = sizeof(clean_disk_entry) + clean_entry_bitmap_size;
    journal.block_size = journal_block_size;
    journal.next_free = journal_block_size;
    journal.used_start = journal_block_size;
@ -224,15 +151,6 @@ 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)
@ -257,7 +175,7 @@ void blockstore_impl_t::calc_lengths()
    }
    // required metadata size
    block_count = data_len / block_size;
-    meta_len = (1 + (block_count - 1 + meta_block_size / clean_entry_size) / (meta_block_size / clean_entry_size)) * meta_block_size;
+    meta_len = ((block_count - 1 + meta_block_size / clean_entry_size) / (meta_block_size / clean_entry_size)) * meta_block_size;
    if (meta_area < meta_len)
    {
        throw std::runtime_error("Metadata area is too small, need at least "+std::to_string(meta_len)+" bytes");
@ -270,7 +188,7 @@ void blockstore_impl_t::calc_lengths()
    }
    else if (clean_entry_bitmap_size)
    {
-        clean_bitmap = (uint8_t*)malloc(block_count * 2*clean_entry_bitmap_size);
+        clean_bitmap = (uint8_t*)malloc(block_count * clean_entry_bitmap_size);
        if (!clean_bitmap)
            throw std::runtime_error("Failed to allocate memory for the metadata sparse write bitmap");
    }
@ -295,9 +213,9 @@ void blockstore_impl_t::calc_lengths()
    }
 }
-static void check_size(int fd, uint64_t *size, uint64_t *sectsize, std::string name)
+void check_size(int fd, uint64_t *size, std::string name)
 {
-    int sect;
+    int sectsize;
    struct stat st;
    if (fstat(fd, &st) < 0)
    {
@ -306,21 +224,14 @@ static void check_size(int fd, uint64_t *size, uint64_t *sectsize, std::string n
    if (S_ISREG(st.st_mode))
    {
        *size = st.st_size;
        if (sectsize)
        {
            *sectsize = st.st_blksize;
        }
    }
    else if (S_ISBLK(st.st_mode))
    {
-        if (ioctl(fd, BLKGETSIZE64, size) < 0 ||
+        if (ioctl(fd, BLKSSZGET, &sectsize) < 0 ||
-            ioctl(fd, BLKSSZGET, &sect) < 0)
+            ioctl(fd, BLKGETSIZE64, size) < 0 ||
            sectsize != 512)
        {
-            throw std::runtime_error("failed to get "+name+" size or block size: "+strerror(errno));
+            throw std::runtime_error(name+" sector is not equal to 512 bytes");
        }
        if (sectsize)
        {
            *sectsize = sect;
        }
    }
    else
@ -336,22 +247,11 @@ void blockstore_impl_t::open_data()
    {
        throw std::runtime_error("Failed to open data device");
    }
-    check_size(data_fd, &data_size, &data_device_sect, "data device");
+    check_size(data_fd, &data_size, "data device");
    if (disk_alignment % data_device_sect)
    {
        throw std::runtime_error(
            "disk_alignment ("+std::to_string(disk_alignment)+
            ") is not a multiple of data device sector size ("+std::to_string(data_device_sect)+")"
        );
    }
    if (data_offset >= data_size)
    {
        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()
@ -364,33 +264,22 @@ void blockstore_impl_t::open_meta()
        {
            throw std::runtime_error("Failed to open metadata device");
        }
-        check_size(meta_fd, &meta_size, &meta_device_sect, "metadata device");
+        check_size(meta_fd, &meta_size, "metadata device");
        if (meta_offset >= meta_size)
        {
            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;
-        meta_device_sect = data_device_sect;
+        disable_meta_fsync = disable_data_fsync;
        meta_size = 0;
        if (meta_offset >= data_size)
        {
            throw std::runtime_error("meta_offset exceeds device size = "+std::to_string(data_size));
        }
    }
    if (meta_block_size % meta_device_sect)
    {
        throw std::runtime_error(
            "meta_block_size ("+std::to_string(meta_block_size)+
            ") is not a multiple of data device sector size ("+std::to_string(meta_device_sect)+")"
        );
    }
 }
 void blockstore_impl_t::open_journal()
@ -402,16 +291,12 @@ void blockstore_impl_t::open_journal()
        {
            throw std::runtime_error("Failed to open journal device");
        }
-        check_size(journal.fd, &journal.device_size, &journal_device_sect, "journal device");
+        check_size(journal.fd, &journal.device_size, "metadata 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;
-        journal_device_sect = meta_device_sect;
+        disable_journal_fsync = disable_meta_fsync;
        journal.device_size = 0;
        if (journal.offset >= data_size)
        {
@ -429,11 +314,4 @@ void blockstore_impl_t::open_journal()
        if (!journal.sector_buf)
            throw std::bad_alloc();
    }
    if (journal_block_size % journal_device_sect)
    {
        throw std::runtime_error(
            "journal_block_size ("+std::to_string(journal_block_size)+
            ") is not a multiple of journal device sector size ("+std::to_string(journal_device_sect)+")"
        );
    }
 }
--- a/src/blockstore_read.cpp
+++ b/src/blockstore_read.cpp
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (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,
@ -11,10 +8,12 @@ int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_
        // Zero-length version - skip
        return 1;
    }
-    else if (IS_IN_FLIGHT(item_state))
+    if (IS_IN_FLIGHT(item_state))
    {
-        // Write not finished yet - skip
+        // Pause until it's written somewhere
-        return 1;
+        PRIV(op)->wait_for = WAIT_IN_FLIGHT;
        PRIV(op)->wait_detail = item_version;
        return 0;
    }
    else if (IS_DELETE(item_state))
    {
@ -40,7 +39,6 @@ int blockstore_impl_t::fulfill_read_push(blockstore_op_t *op, void *buf, uint64_
    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)
 {
@ -53,20 +51,8 @@ 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 = {
@ -85,30 +71,12 @@ 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;
 }
 uint8_t* blockstore_impl_t::get_clean_entry_bitmap(uint64_t block_loc, int offset)
 {
    uint8_t *clean_entry_bitmap;
    uint64_t meta_loc = block_loc >> block_order;
    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) + offset);
    }
    else
        clean_entry_bitmap = (uint8_t*)(clean_bitmap + meta_loc*2*clean_entry_bitmap_size + offset);
    return clean_entry_bitmap;
 }
 int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
 {
    auto clean_it = clean_db.find(read_op->oid);
@ -127,7 +95,7 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
        read_op->version = 0;
        read_op->retval = read_op->len;
        FINISH_OP(read_op);
-        return 2;
+        return 1;
    }
    uint64_t fulfilled = 0;
    PRIV(read_op)->pending_ops = 0;
@ -149,11 +117,6 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
                if (!result_version)
                {
                    result_version = dirty_it->first.version;
                    if (read_op->bitmap)
                    {
                        void *bmp_ptr = (clean_entry_bitmap_size > sizeof(void*) ? dirty_it->second.bitmap : &dirty_it->second.bitmap);
                        memcpy(read_op->bitmap, bmp_ptr, clean_entry_bitmap_size);
                    }
                }
                if (!fulfill_read(read_op, fulfilled, dirty.offset, dirty.offset + dirty.len,
                    dirty.state, dirty_it->first.version, dirty.location + (IS_JOURNAL(dirty.state) ? 0 : dirty.offset)))
@ -170,22 +133,15 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
            dirty_it--;
        }
    }
-    if (clean_it != clean_db.end())
+    if (clean_it != clean_db.end() && fulfilled < read_op->len)
    {
        if (!result_version)
        {
            result_version = clean_it->second.version;
            if (read_op->bitmap)
            {
                void *bmp_ptr = get_clean_entry_bitmap(clean_it->second.location, clean_entry_bitmap_size);
                memcpy(read_op->bitmap, bmp_ptr, clean_entry_bitmap_size);
        }
        }
        if (fulfilled < read_op->len)
        {
        if (!clean_entry_bitmap_size)
        {
-                if (!fulfill_read(read_op, fulfilled, 0, block_size, (BS_ST_BIG_WRITE | BS_ST_STABLE), 0, clean_it->second.location))
+            if (!fulfill_read(read_op, fulfilled, 0, block_size, ST_CURRENT, 0, clean_it->second.location))
            {
                // need to wait. undo added requests, don't dequeue op
                PRIV(read_op)->read_vec.clear();
@ -194,7 +150,18 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
        }
        else
        {
-                uint8_t *clean_entry_bitmap = get_clean_entry_bitmap(clean_it->second.location, 0);
+            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));
            }
            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)
            {
@ -205,8 +172,8 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
                if (bmp_end > bmp_start)
                {
                    // fill with zeroes
-                        assert(fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
+                    fulfill_read(read_op, fulfilled, bmp_start * bitmap_granularity,
-                            bmp_end * bitmap_granularity, (BS_ST_DELETE | BS_ST_STABLE), 0, 0));
+                        bmp_end * bitmap_granularity, ST_DEL_STABLE, 0, 0);
                }
                bmp_start = bmp_end;
                while (clean_entry_bitmap[bmp_end >> 3] & (1 << (bmp_end & 0x7)) && bmp_end < bmp_size)
@ -216,8 +183,7 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
                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,
+                        bmp_end * bitmap_granularity, ST_CURRENT, 0, clean_it->second.location + bmp_start * bitmap_granularity))
                            clean_it->second.location + bmp_start * bitmap_granularity))
                    {
                        // need to wait. undo added requests, don't dequeue op
                        PRIV(read_op)->read_vec.clear();
@ -228,11 +194,10 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
            }
        }
    }
    }
    else if (fulfilled < read_op->len)
    {
        // fill remaining parts with zeroes
-        assert(fulfill_read(read_op, fulfilled, 0, block_size, (BS_ST_DELETE | BS_ST_STABLE), 0, 0));
+        fulfill_read(read_op, fulfilled, 0, block_size, ST_DEL_STABLE, 0, 0);
    }
    assert(fulfilled == read_op->len);
    read_op->version = result_version;
@ -246,10 +211,10 @@ int blockstore_impl_t::dequeue_read(blockstore_op_t *read_op)
        }
        read_op->retval = read_op->len;
        FINISH_OP(read_op);
-        return 2;
+        return 1;
    }
    read_op->retval = 0;
-    return 2;
+    return 1;
 }
 void blockstore_impl_t::handle_read_event(ring_data_t *data, blockstore_op_t *op)
@ -268,50 +233,3 @@ void blockstore_impl_t::handle_read_event(ring_data_t *data, blockstore_op_t *op
        FINISH_OP(op);
    }
 }
 int blockstore_impl_t::read_bitmap(object_id oid, uint64_t target_version, void *bitmap, uint64_t *result_version)
 {
    auto dirty_it = dirty_db.upper_bound((obj_ver_id){
        .oid = oid,
        .version = UINT64_MAX,
    });
    if (dirty_it != dirty_db.begin())
        dirty_it--;
    if (dirty_it != dirty_db.end())
    {
        while (dirty_it->first.oid == oid)
        {
            if (target_version >= dirty_it->first.version)
            {
                if (result_version)
                    *result_version = dirty_it->first.version;
                if (bitmap)
                {
                    void *bmp_ptr = (clean_entry_bitmap_size > sizeof(void*) ? dirty_it->second.bitmap : &dirty_it->second.bitmap);
                    memcpy(bitmap, bmp_ptr, clean_entry_bitmap_size);
                }
                return 0;
            }
            if (dirty_it == dirty_db.begin())
                break;
            dirty_it--;
        }
    }
    auto clean_it = clean_db.find(oid);
    if (clean_it != clean_db.end())
    {
        if (result_version)
            *result_version = clean_it->second.version;
        if (bitmap)
        {
            void *bmp_ptr = get_clean_entry_bitmap(clean_it->second.location, clean_entry_bitmap_size);
            memcpy(bitmap, bmp_ptr, clean_entry_bitmap_size);
        }
        return 0;
    }
    if (result_version)
        *result_version = 0;
    if (bitmap)
        memset(bitmap, 0, clean_entry_bitmap_size);
    return -ENOENT;
 }
--- a/blockstore_rollback.cpp
+++ b/blockstore_rollback.cpp
@ -0,0 +1,187 @@
 #include "blockstore_impl.h"
 int blockstore_impl_t::dequeue_rollback(blockstore_op_t *op)
 {
    obj_ver_id* v;
    int i, todo = op->len;
    for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
    {
        // Check that there are some versions greater than v->version (which may be zero),
        // check that they're unstable, synced, and not currently written to
        auto dirty_it = dirty_db.lower_bound((obj_ver_id){
            .oid = v->oid,
            .version = UINT64_MAX,
        });
        if (dirty_it == dirty_db.begin())
        {
        bad_op:
            op->retval = -EINVAL;
            FINISH_OP(op);
            return 1;
        }
        else
        {
            dirty_it--;
            if (dirty_it->first.oid != v->oid || dirty_it->first.version < v->version)
            {
                goto bad_op;
            }
            while (dirty_it->first.oid == v->oid && dirty_it->first.version > v->version)
            {
                if (!IS_SYNCED(dirty_it->second.state) ||
                    IS_STABLE(dirty_it->second.state))
                {
                    goto bad_op;
                }
                if (dirty_it == dirty_db.begin())
                {
                    break;
                }
                dirty_it--;
            }
        }
    }
    // Check journal space
    blockstore_journal_check_t space_check(this);
    if (!space_check.check_available(op, todo, sizeof(journal_entry_rollback), 0))
    {
        return 0;
    }
    // There is sufficient space. Get SQEs
    struct io_uring_sqe *sqe[space_check.sectors_required];
    for (i = 0; i < space_check.sectors_required; i++)
    {
        BS_SUBMIT_GET_SQE_DECL(sqe[i]);
    }
    // Prepare and submit journal entries
    auto cb = [this, op](ring_data_t *data) { handle_rollback_event(data, op); };
    int s = 0, cur_sector = -1;
    if ((journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_rollback) &&
        journal.sector_info[journal.cur_sector].dirty)
    {
        if (cur_sector == -1)
            PRIV(op)->min_used_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;
        je->oid = v->oid;
        je->version = v->version;
        je->crc32 = je_crc32((journal_entry*)je);
        journal.crc32_last = je->crc32;
        if (cur_sector != journal.cur_sector)
        {
            if (cur_sector == -1)
                PRIV(op)->min_used_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)->pending_ops = s;
    return 1;
 }
 void blockstore_impl_t::handle_rollback_event(ring_data_t *data, blockstore_op_t *op)
 {
    live = true;
    if (data->res != data->iov.iov_len)
    {
        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"
        );
    }
    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++)
        {
            // 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);
        }
        journal.trim();
        // Acknowledge op
        op->retval = 0;
        FINISH_OP(op);
    }
 }
 void blockstore_impl_t::erase_dirty(blockstore_dirty_db_t::iterator dirty_start, blockstore_dirty_db_t::iterator dirty_end, uint64_t clean_loc)
 {
    auto dirty_it = dirty_end;
    while (dirty_it != dirty_start)
    {
        dirty_it--;
        if (IS_BIG_WRITE(dirty_it->second.state) && dirty_it->second.location != clean_loc)
        {
 #ifdef BLOCKSTORE_DEBUG
            printf("Free block %lu\n", dirty_it->second.location >> block_order);
 #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];
        if (used == 0)
        {
            journal.used_sectors.erase(dirty_it->second.journal_sector);
        }
    }
    dirty_db.erase(dirty_start, dirty_end);
 }
--- a/blockstore_stable.cpp
+++ b/blockstore_stable.cpp
@ -0,0 +1,195 @@
 #include "blockstore_impl.h"
 // Stabilize small write:
 // 1) Copy data from the journal to the data device
 // 2) Increase version on the metadata device and sync it
 // 3) Advance clean_db entry's version, clear previous journal entries
 //
 // This makes 1 4K small write+sync look like:
 // 512b+4K (journal) + sync + 512b (journal) + sync + 4K (data) [+ sync?] + 512b (metadata) + sync.
 // WA = 2.375. It's not the best, SSD FTL-like redirect-write could probably be lower
 // even with defragmentation. But it's fixed and it's still better than in Ceph. :)
 // except for HDD-only clusters, because each write results in 3 seeks.
 // Stabilize big write:
 // 1) Copy metadata from the journal to the metadata device
 // 2) Move dirty_db entry to clean_db and clear previous journal entries
 //
 // This makes 1 128K big write+sync look like:
 // 128K (data) + sync + 512b (journal) + sync + 512b (journal) + sync + 512b (metadata) + sync.
 // WA = 1.012. Very good :)
 // Stabilize delete:
 // 1) Remove metadata entry and sync it
 // 2) Remove dirty_db entry and clear previous journal entries
 // We have 2 problems here:
 // - In the cluster environment, we must store the "tombstones" of deleted objects until
 //   all replicas (not just quorum) agrees about their deletion. That is, "stabilize" is
 //   not possible for deletes in degraded placement groups
 // - With simple "fixed" metadata tables we can't just clear the metadata entry of the latest
 //   object version. We must clear all previous entries, too.
 // FIXME Fix both problems - probably, by switching from "fixed" metadata tables to "dynamic"
 // AND We must do it in batches, for the sake of reduced fsync call count
 // AND We must know what we stabilize. Basic workflow is like:
 // 1) primary OSD receives sync request
 // 2) it submits syncs to blockstore and peers
 // 3) after everyone acks sync it acks sync to the client
 // 4) after a while it takes his synced object list and sends stabilize requests
 //    to peers and to its own blockstore, thus freeing the old version
 int blockstore_impl_t::dequeue_stable(blockstore_op_t *op)
 {
    obj_ver_id* v;
    int i, todo = 0;
    for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
    {
        auto dirty_it = dirty_db.find(*v);
        if (dirty_it == dirty_db.end())
        {
            auto clean_it = clean_db.find(v->oid);
            if (clean_it == clean_db.end() || clean_it->second.version < v->version)
            {
                // No such object version
                op->retval = -EINVAL;
                FINISH_OP(op);
                return 1;
            }
            else
            {
                // Already stable
            }
        }
        else if (IS_UNSYNCED(dirty_it->second.state))
        {
            // Object not synced yet. Caller must sync it first
            op->retval = EAGAIN;
            FINISH_OP(op);
            return 1;
        }
        else if (!IS_STABLE(dirty_it->second.state))
        {
            todo++;
        }
    }
    if (!todo)
    {
        // Already stable
        op->retval = 0;
        FINISH_OP(op);
        return 1;
    }
    // Check journal space
    blockstore_journal_check_t space_check(this);
    if (!space_check.check_available(op, todo, sizeof(journal_entry_stable), 0))
    {
        return 0;
    }
    // There is sufficient space. Get SQEs
    struct io_uring_sqe *sqe[space_check.sectors_required];
    for (i = 0; i < space_check.sectors_required; i++)
    {
        BS_SUBMIT_GET_SQE_DECL(sqe[i]);
    }
    // Prepare and submit journal entries
    auto cb = [this, op](ring_data_t *data) { handle_stable_event(data, op); };
    int s = 0, cur_sector = -1;
    if ((journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_stable) &&
        journal.sector_info[journal.cur_sector].dirty)
    {
        if (cur_sector == -1)
            PRIV(op)->min_used_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);
        }
        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;
        je->oid = v->oid;
        je->version = v->version;
        je->crc32 = je_crc32((journal_entry*)je);
        journal.crc32_last = je->crc32;
        if (cur_sector != journal.cur_sector)
        {
            if (cur_sector == -1)
                PRIV(op)->min_used_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)->pending_ops = s;
    return 1;
 }
 void blockstore_impl_t::handle_stable_event(ring_data_t *data, blockstore_op_t *op)
 {
    live = true;
    if (data->res != data->iov.iov_len)
    {
        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"
        );
    }
    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++)
        {
            // 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);
            }
        }
        // Acknowledge op
        op->retval = 0;
        FINISH_OP(op);
    }
 }
--- a/blockstore_sync.cpp
+++ b/blockstore_sync.cpp
@ -0,0 +1,269 @@
 #include "blockstore_impl.h"
 #define SYNC_HAS_SMALL 1
 #define SYNC_HAS_BIG 2
 #define SYNC_DATA_SYNC_SENT 3
 #define SYNC_DATA_SYNC_DONE 4
 #define SYNC_JOURNAL_WRITE_SENT 5
 #define SYNC_JOURNAL_WRITE_DONE 6
 #define SYNC_JOURNAL_SYNC_SENT 7
 #define SYNC_DONE 8
 int blockstore_impl_t::dequeue_sync(blockstore_op_t *op)
 {
    if (PRIV(op)->sync_state == 0)
    {
        stop_sync_submitted = false;
        PRIV(op)->sync_big_writes.swap(unsynced_big_writes);
        PRIV(op)->sync_small_writes.swap(unsynced_small_writes);
        PRIV(op)->sync_small_checked = 0;
        PRIV(op)->sync_big_checked = 0;
        unsynced_big_writes.clear();
        unsynced_small_writes.clear();
        if (PRIV(op)->sync_big_writes.size() > 0)
            PRIV(op)->sync_state = SYNC_HAS_BIG;
        else if (PRIV(op)->sync_small_writes.size() > 0)
            PRIV(op)->sync_state = SYNC_HAS_SMALL;
        else
            PRIV(op)->sync_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);
    }
    continue_sync(op);
    // Always dequeue because we always add syncs to in_progress_syncs
    return 1;
 }
 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)
    {
        // No big writes, just fsync the journal
        for (; PRIV(op)->sync_small_checked < PRIV(op)->sync_small_writes.size(); PRIV(op)->sync_small_checked++)
        {
            if (IS_IN_FLIGHT(dirty_db[PRIV(op)->sync_small_writes[PRIV(op)->sync_small_checked]].state))
            {
                // Wait for small inflight writes to complete
                return 0;
            }
        }
        if (journal.sector_info[journal.cur_sector].dirty)
        {
            // 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)->pending_ops = 1;
            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_SENT;
            return 1;
        }
        else
        {
            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_DONE;
        }
    }
    if (PRIV(op)->sync_state == SYNC_HAS_BIG)
    {
        for (; PRIV(op)->sync_big_checked < PRIV(op)->sync_big_writes.size(); PRIV(op)->sync_big_checked++)
        {
            if (IS_IN_FLIGHT(dirty_db[PRIV(op)->sync_big_writes[PRIV(op)->sync_big_checked]].state))
            {
                // Wait for big inflight writes to complete
                return 0;
            }
        }
        // 1st step: fsync data
        if (!disable_data_fsync)
        {
            BS_SUBMIT_GET_SQE(sqe, data);
            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)->pending_ops = 1;
            PRIV(op)->sync_state = SYNC_DATA_SYNC_SENT;
            return 1;
        }
        else
        {
            PRIV(op)->sync_state = SYNC_DATA_SYNC_DONE;
        }
    }
    if (PRIV(op)->sync_state == SYNC_DATA_SYNC_DONE)
    {
        for (; PRIV(op)->sync_small_checked < PRIV(op)->sync_small_writes.size(); PRIV(op)->sync_small_checked++)
        {
            if (IS_IN_FLIGHT(dirty_db[PRIV(op)->sync_small_writes[PRIV(op)->sync_small_checked]].state))
            {
                // Wait for small inflight writes to complete
                return 0;
            }
        }
        // 2nd step: Data device is synced, prepare & write journal entries
        // Check space in the journal and journal memory buffers
        blockstore_journal_check_t space_check(this);
        if (!space_check.check_available(op, PRIV(op)->sync_big_writes.size(), sizeof(journal_entry_big_write), 0))
        {
            return 0;
        }
        // Get SQEs. Don't bother about merging, submit each journal sector as a separate request
        struct io_uring_sqe *sqe[space_check.sectors_required];
        for (int i = 0; i < space_check.sectors_required; i++)
        {
            BS_SUBMIT_GET_SQE_DECL(sqe[i]);
        }
        // Prepare and submit journal entries
        auto it = PRIV(op)->sync_big_writes.begin();
        int s = 0, cur_sector = -1;
        if ((journal_block_size - journal.in_sector_pos) < sizeof(journal_entry_big_write) &&
            journal.sector_info[journal.cur_sector].dirty)
        {
            if (cur_sector == -1)
                PRIV(op)->min_used_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));
            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);
 #endif
            je->oid = it->oid;
            je->version = it->version;
            je->offset = dirty_db[*it].offset;
            je->len = dirty_db[*it].len;
            je->location = dirty_db[*it].location;
            je->crc32 = je_crc32((journal_entry*)je);
            journal.crc32_last = je->crc32;
            it++;
            if (cur_sector != journal.cur_sector)
            {
                if (cur_sector == -1)
                    PRIV(op)->min_used_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)->pending_ops = s;
        PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_SENT;
        return 1;
    }
    if (PRIV(op)->sync_state == SYNC_JOURNAL_WRITE_DONE)
    {
        if (!disable_journal_fsync)
        {
            BS_SUBMIT_GET_SQE(sqe, data);
            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;
            return 1;
        }
        else
        {
            PRIV(op)->sync_state = SYNC_DONE;
        }
    }
    if (PRIV(op)->sync_state == SYNC_DONE)
    {
        ack_sync(op);
    }
    return 1;
 }
 void blockstore_impl_t::handle_sync_event(ring_data_t *data, blockstore_op_t *op)
 {
    live = true;
    if (data->res != data->iov.iov_len)
    {
        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"
        );
    }
    PRIV(op)->pending_ops--;
    if (PRIV(op)->pending_ops == 0)
    {
        // Release used journal sectors
        release_journal_sectors(op);
        // Handle states
        if (PRIV(op)->sync_state == SYNC_DATA_SYNC_SENT)
        {
            PRIV(op)->sync_state = SYNC_DATA_SYNC_DONE;
        }
        else if (PRIV(op)->sync_state == SYNC_JOURNAL_WRITE_SENT)
        {
            PRIV(op)->sync_state = SYNC_JOURNAL_WRITE_DONE;
        }
        else if (PRIV(op)->sync_state == SYNC_JOURNAL_SYNC_SENT)
        {
            PRIV(op)->sync_state = SYNC_DONE;
            ack_sync(op);
        }
        else
        {
            throw std::runtime_error("BUG: unexpected sync op state");
        }
    }
 }
 int blockstore_impl_t::ack_sync(blockstore_op_t *op)
 {
    if (PRIV(op)->sync_state == SYNC_DONE && PRIV(op)->prev_sync_count == 0)
    {
        // Remove dependency of subsequent syncs
        auto it = PRIV(op)->in_progress_ptr;
        int done_syncs = 1;
        ++it;
        // Acknowledge sync
        ack_one_sync(op);
        while (it != in_progress_syncs.end())
        {
            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)
            {
                done_syncs++;
                // Acknowledge next_sync
                ack_one_sync(next_sync);
            }
        }
        return 1;
    }
    return 0;
 }
 void blockstore_impl_t::ack_one_sync(blockstore_op_t *op)
 {
    // Handle states
    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);
 #endif
        auto & unstab = unstable_writes[it->oid];
        unstab = unstab < it->version ? it->version : unstab;
        dirty_db[*it].state = ST_D_META_SYNCED;
    }
    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);
 #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;
    }
    in_progress_syncs.erase(PRIV(op)->in_progress_ptr);
    op->retval = 0;
    FINISH_OP(op);
 }
--- a/blockstore_write.cpp
+++ b/blockstore_write.cpp
@ -0,0 +1,328 @@
 #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);
    uint64_t version = 1;
    if (dirty_db.size() > 0)
    {
        auto dirty_it = dirty_db.upper_bound((obj_ver_id){
            .oid = op->oid,
            .version = UINT64_MAX,
        });
        dirty_it--; // segfaults when dirty_db is empty
        if (dirty_it != dirty_db.end() && dirty_it->first.oid == op->oid)
        {
            found = true;
            version = dirty_it->first.version + 1;
            deleted = IS_DELETE(dirty_it->second.state);
        }
    }
    if (!found)
    {
        auto clean_it = clean_db.find(op->oid);
        if (clean_it != clean_db.end())
        {
            version = clean_it->second.version + 1;
        }
        else
        {
            deleted = true;
        }
    }
    if (op->version == 0)
    {
        op->version = version;
    }
    else if (op->version < version)
    {
        // Invalid version requested
        op->retval = -EINVAL;
        return false;
    }
    if (deleted && is_del)
    {
        // Already deleted
        op->retval = 0;
        return false;
    }
    // Immediately add the operation into dirty_db, so subsequent reads could see it
 #ifdef BLOCKSTORE_DEBUG
    printf("%s %lu:%lu v%lu\n", is_del ? "Delete" : "Write", op->oid.inode, op->oid.stripe, op->version);
 #endif
    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)
        ),
        .flags = 0,
        .location = 0,
        .offset = is_del ? 0 : op->offset,
        .len = is_del ? 0 : op->len,
        .journal_sector = 0,
    });
    return true;
 }
 // First step of the write algorithm: dequeue operation and submit initial write(s)
 int blockstore_impl_t::dequeue_write(blockstore_op_t *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)
    {
        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))
        {
            return 0;
        }
        // Big (redirect) write
        uint64_t loc = data_alloc->find_free();
        if (loc == UINT64_MAX)
        {
            // no space
            if (flusher->is_active())
            {
                // hope that some space will be available after flush
                PRIV(op)->wait_for = WAIT_FREE;
                return 0;
            }
            op->retval = -ENOSPC;
            FINISH_OP(op);
            return 1;
        }
        BS_SUBMIT_GET_SQE(sqe, data);
        dirty_it->second.location = loc << block_order;
        dirty_it->second.state = ST_D_SUBMITTED;
 #ifdef BLOCKSTORE_DEBUG
        printf("Allocate block %lu\n", loc);
 #endif
        data_alloc->set(loc, true);
        uint64_t stripe_offset = (op->offset % bitmap_granularity);
        uint64_t stripe_end = (op->offset + op->len) % bitmap_granularity;
        // Zero fill up to bitmap_granularity
        int vcnt = 0;
        if (stripe_offset)
        {
            PRIV(op)->iov_zerofill[vcnt++] = (struct iovec){ zero_object, stripe_offset };
        }
        PRIV(op)->iov_zerofill[vcnt++] = (struct iovec){ op->buf, op->len };
        if (stripe_end)
        {
            stripe_end = bitmap_granularity - stripe_end;
            PRIV(op)->iov_zerofill[vcnt++] = (struct iovec){ zero_object, stripe_end };
        }
        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, PRIV(op)->iov_zerofill, vcnt, data_offset + (loc << block_order) + op->offset - stripe_offset
        );
        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,
        });
    }
    else
    {
        // Small (journaled) write
        // First check if the journal has sufficient space
        blockstore_journal_check_t space_check(this);
        if (unsynced_big_writes.size() && !space_check.check_available(op, unsynced_big_writes.size(), sizeof(journal_entry_big_write), 0)
            || !space_check.check_available(op, 1, sizeof(journal_entry_small_write), op->len + JOURNAL_STABILIZE_RESERVATION))
        {
            return 0;
        }
        // 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) &&
            journal.sector_info[journal.cur_sector].dirty)
        {
            // Write current journal sector only if it's dirty and full
            BS_SUBMIT_GET_SQE_DECL(sqe1);
        }
        struct io_uring_sqe *sqe2 = NULL;
        if (op->len > 0)
        {
            BS_SUBMIT_GET_SQE_DECL(sqe2);
        }
        // Got SQEs. Prepare previous journal sector write if required
        auto cb = [this, op](ring_data_t *data) { handle_write_event(data, op); };
        if (sqe1)
        {
            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;
        }
        // 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));
        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);
 #endif
        // Figure out where data will be
        journal.next_free = (journal.next_free + op->len) <= journal.len ? journal.next_free : journal_block_size;
        je->oid = op->oid;
        je->version = op->version;
        je->offset = op->offset;
        je->len = op->len;
        je->data_offset = journal.next_free;
        je->crc32_data = crc32c(0, op->buf, op->len);
        je->crc32 = je_crc32((journal_entry*)je);
        journal.crc32_last = je->crc32;
        if (op->len > 0)
        {
            // Prepare journal data write
            if (journal.inmemory)
            {
                // Copy data
                memcpy(journal.buffer + journal.next_free, op->buf, op->len);
            }
            ring_data_t *data2 = ((ring_data_t*)sqe2->user_data);
            data2->iov = (struct iovec){ op->buf, op->len };
            data2->callback = cb;
            my_uring_prep_writev(
                sqe2, journal.fd, &data2->iov, 1, journal.offset + journal.next_free
            );
            PRIV(op)->pending_ops++;
        }
        else
        {
            // 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;
        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 (!PRIV(op)->pending_ops)
        {
            ack_write(op);
        }
    }
    return 1;
 }
 void blockstore_impl_t::handle_write_event(ring_data_t *data, blockstore_op_t *op)
 {
    live = true;
    if (data->res != data->iov.iov_len)
    {
        // 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)+
            "). in-memory state is corrupted. AAAAAAAaaaaaaaaa!!!111"
        );
    }
    PRIV(op)->pending_ops--;
    if (PRIV(op)->pending_ops == 0)
    {
        release_journal_sectors(op);
        ack_write(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)
    {
        uint64_t s = PRIV(op)->min_used_journal_sector;
        while (1)
        {
            journal.sector_info[s-1].usage_count--;
            if (s == PRIV(op)->max_used_journal_sector)
                break;
            s = 1 + s % journal.sector_count;
        }
        PRIV(op)->min_used_journal_sector = PRIV(op)->max_used_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,
    });
    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);
    // Prepare journal sector write
    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);
 #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,
    });
    return 1;
 }
--- a/copy-fio-includes.sh
+++ b/copy-fio-includes.sh
@ -1,13 +0,0 @@
 #!/bin/bash
 gcc -I. -E -o fio_headers.i src/fio_headers.h
 rm -rf fio-copy
 for i in `grep -Po 'fio/[^"]+' fio_headers.i | sort | uniq`; do
    j=${i##fio/}
    p=$(dirname $j)
    mkdir -p fio-copy/$p
    cp $i fio-copy/$j
 done
 rm fio_headers.i
--- a/copy-qemu-includes.sh
+++ b/copy-qemu-includes.sh
@ -1,18 +0,0 @@
 #!/bin/bash
 #cd qemu
 #debian/rules b/configure-stamp
 #cd b/qemu; make qapi
 gcc -I qemu/b/qemu `pkg-config glib-2.0 --cflags` \
    -I qemu/include -E -o qemu_driver.i src/qemu_driver.c
 rm -rf qemu-copy
 for i in `grep -Po 'qemu/[^"]+' qemu_driver.i | sort | uniq`; do
    j=${i##qemu/}
    p=$(dirname $j)
    mkdir -p qemu-copy/$p
    cp $i qemu-copy/$j
 done
 rm qemu_driver.i
--- a/1
+++ b/1
@ -1 +0,0 @@
 Subproject commit 5dc108754ad40d3b1d024f9bd7cca0595ef1a1db
--- a/src/crc32c.c
+++ b/src/crc32c.c
--- a/src/crc32c.h
+++ b/src/crc32c.h
@ -8,10 +8,4 @@
 // unsigned __int64 _mm_crc32_u64 (unsigned __int64 crc, unsigned __int64 v)
 // unsigned int _mm_crc32_u8 (unsigned int crc, unsigned char v)
 #ifdef __cplusplus
 extern "C" {
 #endif
 uint32_t crc32c(uint32_t crc, const void *buf, size_t len);
 #ifdef __cplusplus
 };
 #endif
--- a/csi/.dockerignore
+++ b/csi/.dockerignore
@ -1,2 +0,0 @@
 vitastor-csi
 Dockerfile
--- a/csi/Dockerfile
+++ b/csi/Dockerfile
@ -1,32 +0,0 @@
 # Compile stage
 FROM golang:buster AS build
 ADD go.sum go.mod /app/
 RUN cd /app; CGO_ENABLED=1 GOOS=linux GOARCH=amd64 go mod download -x
 ADD . /app
 RUN perl -i -e '$/ = undef; while(<>) { s/\n\s*(\{\s*\n)/$1\n/g; s/\}(\s*\n\s*)else\b/$1} else/g; print; }' `find /app -name '*.go'`
 RUN cd /app; CGO_ENABLED=1 GOOS=linux GOARCH=amd64 go build -o vitastor-csi
 # Final stage
 FROM debian:buster
 LABEL maintainers="Vitaliy Filippov <vitalif@yourcmc.ru>"
 LABEL description="Vitastor CSI Driver"
 ENV NODE_ID=""
 ENV CSI_ENDPOINT=""
 RUN apt-get update && \
    apt-get install -y wget && \
    wget -q -O /etc/apt/trusted.gpg.d/vitastor.gpg https://vitastor.io/debian/pubkey.gpg && \
    (echo deb http://vitastor.io/debian buster main > /etc/apt/sources.list.d/vitastor.list) && \
    (echo deb http://deb.debian.org/debian buster-backports main > /etc/apt/sources.list.d/backports.list) && \
    (echo "APT::Install-Recommends false;" > /etc/apt/apt.conf) && \
    apt-get update && \
    apt-get install -y e2fsprogs xfsprogs vitastor kmod && \
    apt-get clean && \
    (echo options nbd nbds_max=128 > /etc/modprobe.d/nbd.conf)
 COPY --from=build /app/vitastor-csi /bin/
 ENTRYPOINT ["/bin/vitastor-csi"]
--- a/csi/Makefile
+++ b/csi/Makefile
@ -1,9 +0,0 @@
 VERSION ?= v0.6.10
 all: build push
 build:
 	@docker build --rm -t vitalif/vitastor-csi:$(VERSION) .
 push:
 	@docker push vitalif/vitastor-csi:$(VERSION)
--- a/csi/deploy/000-csi-namespace.yaml
+++ b/csi/deploy/000-csi-namespace.yaml
@ -1,5 +0,0 @@
 ---
 apiVersion: v1
 kind: Namespace
 metadata:
  name: vitastor-system
--- a/csi/deploy/001-csi-config-map.yaml
+++ b/csi/deploy/001-csi-config-map.yaml
@ -1,9 +0,0 @@
 ---
 apiVersion: v1
 kind: ConfigMap
 data:
  vitastor.conf: |-
    {"etcd_address":"http://192.168.7.2:2379","etcd_prefix":"/vitastor"}
 metadata:
  namespace: vitastor-system
  name: vitastor-config
--- a/csi/deploy/002-csi-nodeplugin-rbac.yaml
+++ b/csi/deploy/002-csi-nodeplugin-rbac.yaml
@ -1,37 +0,0 @@
 ---
 apiVersion: v1
 kind: ServiceAccount
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin
 ---
 kind: ClusterRole
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin
 rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get"]
  # allow to read Vault Token and connection options from the Tenants namespace
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]
  - apiGroups: [""]
    resources: ["configmaps"]
    verbs: ["get"]
 ---
 kind: ClusterRoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin
 subjects:
  - kind: ServiceAccount
    name: vitastor-csi-nodeplugin
    namespace: vitastor-system
 roleRef:
  kind: ClusterRole
  name: vitastor-csi-nodeplugin
  apiGroup: rbac.authorization.k8s.io
--- a/csi/deploy/003-csi-nodeplugin-psp.yaml
+++ b/csi/deploy/003-csi-nodeplugin-psp.yaml
@ -1,72 +0,0 @@
 ---
 apiVersion: policy/v1beta1
 kind: PodSecurityPolicy
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin-psp
 spec:
  allowPrivilegeEscalation: true
  allowedCapabilities:
    - 'SYS_ADMIN'
  fsGroup:
    rule: RunAsAny
  privileged: true
  hostNetwork: true
  hostPID: true
  runAsUser:
    rule: RunAsAny
  seLinux:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  volumes:
    - 'configMap'
    - 'emptyDir'
    - 'projected'
    - 'secret'
    - 'downwardAPI'
    - 'hostPath'
  allowedHostPaths:
    - pathPrefix: '/dev'
      readOnly: false
    - pathPrefix: '/run/mount'
      readOnly: false
    - pathPrefix: '/sys'
      readOnly: false
    - pathPrefix: '/lib/modules'
      readOnly: true
    - pathPrefix: '/var/lib/kubelet/pods'
      readOnly: false
    - pathPrefix: '/var/lib/kubelet/plugins/csi.vitastor.io'
      readOnly: false
    - pathPrefix: '/var/lib/kubelet/plugins_registry'
      readOnly: false
    - pathPrefix: '/var/lib/kubelet/plugins'
      readOnly: false
 ---
 kind: Role
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin-psp
 rules:
  - apiGroups: ['policy']
    resources: ['podsecuritypolicies']
    verbs: ['use']
    resourceNames: ['vitastor-csi-nodeplugin-psp']
 ---
 kind: RoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-nodeplugin-psp
 subjects:
  - kind: ServiceAccount
    name: vitastor-csi-nodeplugin
    namespace: vitastor-system
 roleRef:
  kind: Role
  name: vitastor-csi-nodeplugin-psp
  apiGroup: rbac.authorization.k8s.io
--- a/csi/deploy/004-csi-nodeplugin.yaml
+++ b/csi/deploy/004-csi-nodeplugin.yaml
@ -1,140 +0,0 @@
 ---
 kind: DaemonSet
 apiVersion: apps/v1
 metadata:
  namespace: vitastor-system
  name: csi-vitastor
 spec:
  selector:
    matchLabels:
      app: csi-vitastor
  template:
    metadata:
      namespace: vitastor-system
      labels:
        app: csi-vitastor
    spec:
      serviceAccountName: vitastor-csi-nodeplugin
      hostNetwork: true
      hostPID: true
      priorityClassName: system-node-critical
      # to use e.g. Rook orchestrated cluster, and mons' FQDN is
      # resolved through k8s service, set dns policy to cluster first
      dnsPolicy: ClusterFirstWithHostNet
      containers:
        - name: driver-registrar
          # This is necessary only for systems with SELinux, where
          # non-privileged sidecar containers cannot access unix domain socket
          # created by privileged CSI driver container.
          securityContext:
            privileged: true
          image: k8s.gcr.io/sig-storage/csi-node-driver-registrar:v2.2.0
          args:
            - "--v=5"
            - "--csi-address=/csi/csi.sock"
            - "--kubelet-registration-path=/var/lib/kubelet/plugins/csi.vitastor.io/csi.sock"
          env:
            - name: KUBE_NODE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
            - name: registration-dir
              mountPath: /registration
        - name: csi-vitastor
          securityContext:
            privileged: true
            capabilities:
              add: ["SYS_ADMIN"]
            allowPrivilegeEscalation: true
          image: vitalif/vitastor-csi:v0.6.10
          args:
            - "--node=$(NODE_ID)"
            - "--endpoint=$(CSI_ENDPOINT)"
          env:
            - name: NODE_ID
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: CSI_ENDPOINT
              value: unix:///csi/csi.sock
          imagePullPolicy: "IfNotPresent"
          ports:
          - containerPort: 9898
            name: healthz
            protocol: TCP
          livenessProbe:
            failureThreshold: 5
            httpGet:
              path: /healthz
              port: healthz
            initialDelaySeconds: 10
            timeoutSeconds: 3
            periodSeconds: 2
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
            - mountPath: /dev
              name: host-dev
            - mountPath: /sys
              name: host-sys
            - mountPath: /run/mount
              name: host-mount
            - mountPath: /lib/modules
              name: lib-modules
              readOnly: true
            - name: vitastor-config
              mountPath: /etc/vitastor
            - name: plugin-dir
              mountPath: /var/lib/kubelet/plugins
              mountPropagation: "Bidirectional"
            - name: mountpoint-dir
              mountPath: /var/lib/kubelet/pods
              mountPropagation: "Bidirectional"
        - name: liveness-probe
          securityContext:
            privileged: true
          image: quay.io/k8scsi/livenessprobe:v1.1.0
          args:
            - "--csi-address=$(CSI_ENDPOINT)"
            - "--health-port=9898"
          env:
            - name: CSI_ENDPOINT
              value: unix://csi/csi.sock
          volumeMounts:
          - mountPath: /csi
            name: socket-dir
      volumes:
        - name: socket-dir
          hostPath:
            path: /var/lib/kubelet/plugins/csi.vitastor.io
            type: DirectoryOrCreate
        - name: plugin-dir
          hostPath:
            path: /var/lib/kubelet/plugins
            type: Directory
        - name: mountpoint-dir
          hostPath:
            path: /var/lib/kubelet/pods
            type: DirectoryOrCreate
        - name: registration-dir
          hostPath:
            path: /var/lib/kubelet/plugins_registry/
            type: Directory
        - name: host-dev
          hostPath:
            path: /dev
        - name: host-sys
          hostPath:
            path: /sys
        - name: host-mount
          hostPath:
            path: /run/mount
        - name: lib-modules
          hostPath:
            path: /lib/modules
        - name: vitastor-config
          configMap:
            name: vitastor-config
--- a/csi/deploy/005-csi-provisioner-rbac.yaml
+++ b/csi/deploy/005-csi-provisioner-rbac.yaml
@ -1,102 +0,0 @@
 ---
 apiVersion: v1
 kind: ServiceAccount
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-provisioner
 ---
 kind: ClusterRole
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-external-provisioner-runner
 rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["list", "watch", "create", "update", "patch"]
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "update", "delete", "patch"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims/status"]
    verbs: ["update", "patch"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: ["snapshot.storage.k8s.io"]
    resources: ["volumesnapshots"]
    verbs: ["get", "list"]
  - apiGroups: ["snapshot.storage.k8s.io"]
    resources: ["volumesnapshotcontents"]
    verbs: ["create", "get", "list", "watch", "update", "delete"]
  - apiGroups: ["snapshot.storage.k8s.io"]
    resources: ["volumesnapshotclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["volumeattachments"]
    verbs: ["get", "list", "watch", "update", "patch"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["volumeattachments/status"]
    verbs: ["patch"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["csinodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: ["snapshot.storage.k8s.io"]
    resources: ["volumesnapshotcontents/status"]
    verbs: ["update"]
  - apiGroups: [""]
    resources: ["configmaps"]
    verbs: ["get"]
 ---
 kind: ClusterRoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-provisioner-role
 subjects:
  - kind: ServiceAccount
    name: vitastor-csi-provisioner
    namespace: vitastor-system
 roleRef:
  kind: ClusterRole
  name: vitastor-external-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
 ---
 kind: Role
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-external-provisioner-cfg
 rules:
  - apiGroups: [""]
    resources: ["configmaps"]
    verbs: ["get", "list", "watch", "create", "update", "delete"]
  - apiGroups: ["coordination.k8s.io"]
    resources: ["leases"]
    verbs: ["get", "watch", "list", "delete", "update", "create"]
 ---
 kind: RoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  name: vitastor-csi-provisioner-role-cfg
  namespace: vitastor-system
 subjects:
  - kind: ServiceAccount
    name: vitastor-csi-provisioner
    namespace: vitastor-system
 roleRef:
  kind: Role
  name: vitastor-external-provisioner-cfg
  apiGroup: rbac.authorization.k8s.io
--- a/csi/deploy/006-csi-provisioner-psp.yaml
+++ b/csi/deploy/006-csi-provisioner-psp.yaml
@ -1,60 +0,0 @@
 ---
 apiVersion: policy/v1beta1
 kind: PodSecurityPolicy
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-provisioner-psp
 spec:
  allowPrivilegeEscalation: true
  allowedCapabilities:
    - 'SYS_ADMIN'
  fsGroup:
    rule: RunAsAny
  privileged: true
  runAsUser:
    rule: RunAsAny
  seLinux:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  volumes:
    - 'configMap'
    - 'emptyDir'
    - 'projected'
    - 'secret'
    - 'downwardAPI'
    - 'hostPath'
  allowedHostPaths:
    - pathPrefix: '/dev'
      readOnly: false
    - pathPrefix: '/sys'
      readOnly: false
    - pathPrefix: '/lib/modules'
      readOnly: true
 ---
 kind: Role
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  namespace: vitastor-system
  name: vitastor-csi-provisioner-psp
 rules:
  - apiGroups: ['policy']
    resources: ['podsecuritypolicies']
    verbs: ['use']
    resourceNames: ['vitastor-csi-provisioner-psp']
 ---
 kind: RoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
  name: vitastor-csi-provisioner-psp
  namespace: vitastor-system
 subjects:
  - kind: ServiceAccount
    name: vitastor-csi-provisioner
    namespace: vitastor-system
 roleRef:
  kind: Role
  name: vitastor-csi-provisioner-psp
  apiGroup: rbac.authorization.k8s.io
--- a/csi/deploy/007-csi-provisioner.yaml
+++ b/csi/deploy/007-csi-provisioner.yaml
@ -1,159 +0,0 @@
 ---
 kind: Service
 apiVersion: v1
 metadata:
  namespace: vitastor-system
  name: csi-vitastor-provisioner
  labels:
    app: csi-metrics
 spec:
  selector:
    app: csi-vitastor-provisioner
  ports:
    - name: http-metrics
      port: 8080
      protocol: TCP
      targetPort: 8680
 ---
 kind: Deployment
 apiVersion: apps/v1
 metadata:
  namespace: vitastor-system
  name: csi-vitastor-provisioner
 spec:
  replicas: 3
  selector:
    matchLabels:
      app: csi-vitastor-provisioner
  template:
    metadata:
      namespace: vitastor-system
      labels:
        app: csi-vitastor-provisioner
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: app
                    operator: In
                    values:
                      - csi-vitastor-provisioner
              topologyKey: "kubernetes.io/hostname"
      serviceAccountName: vitastor-csi-provisioner
      priorityClassName: system-cluster-critical
      containers:
        - name: csi-provisioner
          image: k8s.gcr.io/sig-storage/csi-provisioner:v2.2.0
          args:
            - "--csi-address=$(ADDRESS)"
            - "--v=5"
            - "--timeout=150s"
            - "--retry-interval-start=500ms"
            - "--leader-election=true"
            #  set it to true to use topology based provisioning
            - "--feature-gates=Topology=false"
            # if fstype is not specified in storageclass, ext4 is default
            - "--default-fstype=ext4"
            - "--extra-create-metadata=true"
          env:
            - name: ADDRESS
              value: unix:///csi/csi-provisioner.sock
          imagePullPolicy: "IfNotPresent"
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
        - name: csi-snapshotter
          image: k8s.gcr.io/sig-storage/csi-snapshotter:v4.0.0
          args:
            - "--csi-address=$(ADDRESS)"
            - "--v=5"
            - "--timeout=150s"
            - "--leader-election=true"
          env:
            - name: ADDRESS
              value: unix:///csi/csi-provisioner.sock
          imagePullPolicy: "IfNotPresent"
          securityContext:
            privileged: true
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
        - name: csi-attacher
          image: k8s.gcr.io/sig-storage/csi-attacher:v3.1.0
          args:
            - "--v=5"
            - "--csi-address=$(ADDRESS)"
            - "--leader-election=true"
            - "--retry-interval-start=500ms"
          env:
            - name: ADDRESS
              value: /csi/csi-provisioner.sock
          imagePullPolicy: "IfNotPresent"
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
        - name: csi-resizer
          image: k8s.gcr.io/sig-storage/csi-resizer:v1.1.0
          args:
            - "--csi-address=$(ADDRESS)"
            - "--v=5"
            - "--timeout=150s"
            - "--leader-election"
            - "--retry-interval-start=500ms"
            - "--handle-volume-inuse-error=false"
          env:
            - name: ADDRESS
              value: unix:///csi/csi-provisioner.sock
          imagePullPolicy: "IfNotPresent"
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
        - name: csi-vitastor
          securityContext:
            privileged: true
            capabilities:
              add: ["SYS_ADMIN"]
          image: vitalif/vitastor-csi:v0.6.10
          args:
            - "--node=$(NODE_ID)"
            - "--endpoint=$(CSI_ENDPOINT)"
          env:
            - name: NODE_ID
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: CSI_ENDPOINT
              value: unix:///csi/csi-provisioner.sock
          imagePullPolicy: "IfNotPresent"
          volumeMounts:
            - name: socket-dir
              mountPath: /csi
            - mountPath: /dev
              name: host-dev
            - mountPath: /sys
              name: host-sys
            - mountPath: /lib/modules
              name: lib-modules
              readOnly: true
            - name: vitastor-config
              mountPath: /etc/vitastor
      volumes:
        - name: host-dev
          hostPath:
            path: /dev
        - name: host-sys
          hostPath:
            path: /sys
        - name: lib-modules
          hostPath:
            path: /lib/modules
        - name: socket-dir
          emptyDir: {
            medium: "Memory"
          }
        - name: vitastor-config
          configMap:
            name: vitastor-config
--- a/csi/deploy/008-csi-driver.yaml
+++ b/csi/deploy/008-csi-driver.yaml
@ -1,11 +0,0 @@
 ---
 # if Kubernetes version is less than 1.18 change
 # apiVersion to storage.k8s.io/v1betav1
 apiVersion: storage.k8s.io/v1
 kind: CSIDriver
 metadata:
  namespace: vitastor-system
  name: csi.vitastor.io
 spec:
  attachRequired: true
  podInfoOnMount: false
--- a/csi/deploy/009-storage-class.yaml
+++ b/csi/deploy/009-storage-class.yaml
@ -1,19 +0,0 @@
 ---
 apiVersion: storage.k8s.io/v1
 kind: StorageClass
 metadata:
  namespace: vitastor-system
  name: vitastor
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
 provisioner: csi.vitastor.io
 volumeBindingMode: Immediate
 parameters:
  etcdVolumePrefix: ""
  poolId: "1"
  # you can choose other configuration file if you have it in the config map
  #configPath: "/etc/vitastor/vitastor.conf"
  # you can also specify etcdUrl here, maybe to connect to another Vitastor cluster
  # multiple etcdUrls may be specified, delimited by comma
  #etcdUrl: "http://192.168.7.2:2379"
  #etcdPrefix: "/vitastor"
--- a/csi/deploy/example-pvc.yaml
+++ b/csi/deploy/example-pvc.yaml
@ -1,12 +0,0 @@
 ---
 apiVersion: v1
 kind: PersistentVolumeClaim
 metadata:
  name: test-vitastor-pvc
 spec:
  storageClassName: vitastor
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
--- a/csi/go.mod
+++ b/csi/go.mod
@ -1,35 +0,0 @@
 module vitastor.io/csi
 go 1.15
 require (
 	github.com/container-storage-interface/spec v1.4.0
 	github.com/coreos/bbolt v0.0.0-00010101000000-000000000000 // indirect
 	github.com/coreos/etcd v3.3.25+incompatible // indirect
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf // indirect
 	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
 	github.com/dustin/go-humanize v1.0.0 // indirect
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/gorilla/websocket v1.4.2 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
 	github.com/jonboulle/clockwork v0.2.2 // indirect
 	github.com/kubernetes-csi/csi-lib-utils v0.9.1
 	github.com/soheilhy/cmux v0.1.5 // indirect
 	github.com/tmc/grpc-websocket-proxy v0.0.0-20201229170055-e5319fda7802 // indirect
 	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
 	go.etcd.io/bbolt v0.0.0-00010101000000-000000000000 // indirect
 	go.etcd.io/etcd v3.3.25+incompatible
 	golang.org/x/net v0.0.0-20201202161906-c7110b5ffcbb
 	google.golang.org/grpc v1.33.1
 	k8s.io/klog v1.0.0
 	k8s.io/utils v0.0.0-20210305010621-2afb4311ab10
 )
 replace github.com/coreos/bbolt => go.etcd.io/bbolt v1.3.5
 replace go.etcd.io/bbolt => github.com/coreos/bbolt v1.3.5
 replace google.golang.org/grpc => google.golang.org/grpc v1.25.1
--- a/csi/go.sum
+++ b/csi/go.sum
@ -1,448 +0,0 @@
 cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 cloud.google.com/go v0.38.0/go.mod h1:990N+gfupTy94rShfmMCWGDn0LpTmnzTp2qbd1dvSRU=
 cloud.google.com/go v0.44.1/go.mod h1:iSa0KzasP4Uvy3f1mN/7PiObzGgflwredwwASm/v6AU=
 cloud.google.com/go v0.44.2/go.mod h1:60680Gw3Yr4ikxnPRS/oxxkBccT6SA1yMk63TGekxKY=
 cloud.google.com/go v0.45.1/go.mod h1:RpBamKRgapWJb87xiFSdk4g1CME7QZg3uwTez+TSTjc=
 cloud.google.com/go v0.46.3/go.mod h1:a6bKKbmY7er1mI7TEI4lsAkts/mkhTSZK8w33B4RAg0=
 cloud.google.com/go v0.51.0/go.mod h1:hWtGJ6gnXH+KgDv+V0zFGDvpi07n3z8ZNj3T1RW0Gcw=
 cloud.google.com/go/bigquery v1.0.1/go.mod h1:i/xbL2UlR5RvWAURpBYZTtm/cXjCha9lbfbpx4poX+o=
 cloud.google.com/go/datastore v1.0.0/go.mod h1:LXYbyblFSglQ5pkeyhO+Qmw7ukd3C+pD7TKLgZqpHYE=
 cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
 cloud.google.com/go/storage v1.0.0/go.mod h1:IhtSnM/ZTZV8YYJWCY8RULGVqBDmpoyjwiyrjsg+URw=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78/go.mod h1:LmzpDX56iTiv29bbRTIsUNlaFfuhWRQBWjQdVyAevI8=
 github.com/Azure/go-autorest/autorest v0.9.0/go.mod h1:xyHB1BMZT0cuDHU7I0+g046+BFDTQ8rEZB0s4Yfa6bI=
 github.com/Azure/go-autorest/autorest v0.9.6/go.mod h1:/FALq9T/kS7b5J5qsQ+RSTUdAmGFqi0vUdVNNx8q630=
 github.com/Azure/go-autorest/autorest/adal v0.5.0/go.mod h1:8Z9fGy2MpX0PvDjB1pEgQTmVqjGhiHBW7RJJEciWzS0=
 github.com/Azure/go-autorest/autorest/adal v0.8.2/go.mod h1:ZjhuQClTqx435SRJ2iMlOxPYt3d2C/T/7TiQCVZSn3Q=
 github.com/Azure/go-autorest/autorest/date v0.1.0/go.mod h1:plvfp3oPSKwf2DNjlBjWF/7vwR+cUD/ELuzDCXwHUVA=
 github.com/Azure/go-autorest/autorest/date v0.2.0/go.mod h1:vcORJHLJEh643/Ioh9+vPmf1Ij9AEBM5FuBIXLmIy0g=
 github.com/Azure/go-autorest/autorest/mocks v0.1.0/go.mod h1:OTyCOPRA2IgIlWxVYxBee2F5Gr4kF2zd2J5cFRaIDN0=
 github.com/Azure/go-autorest/autorest/mocks v0.2.0/go.mod h1:OTyCOPRA2IgIlWxVYxBee2F5Gr4kF2zd2J5cFRaIDN0=
 github.com/Azure/go-autorest/autorest/mocks v0.3.0/go.mod h1:a8FDP3DYzQ4RYfVAxAN3SVSiiO77gL2j2ronKKP0syM=
 github.com/Azure/go-autorest/logger v0.1.0/go.mod h1:oExouG+K6PryycPJfVSxi/koC6LSNgds39diKLz7Vrc=
 github.com/Azure/go-autorest/tracing v0.5.0/go.mod h1:r/s2XiOKccPW3HrqB+W0TQzfbtp2fGCgRFtBroKn4Dk=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/NYTimes/gziphandler v0.0.0-20170623195520-56545f4a5d46/go.mod h1:3wb06e3pkSAbeQ52E9H9iFoQsEEwGN64994WTCIhntQ=
 github.com/PuerkitoBio/purell v1.0.0/go.mod h1:c11w/QuzBsJSee3cPx9rAFu61PvFxuPbtSwDGJws/X0=
 github.com/PuerkitoBio/urlesc v0.0.0-20160726150825-5bd2802263f2/go.mod h1:uGdkoq3SwY9Y+13GIhn11/XLaGBb4BfwItxLd5jeuXE=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
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 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
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 k8s.io/kube-openapi v0.0.0-20200805222855-6aeccd4b50c6/go.mod h1:UuqjUnNftUyPE5H64/qeyjQoUZhGpeFDVdxjTeEVN2o=
 k8s.io/utils v0.0.0-20200729134348-d5654de09c73/go.mod h1:jPW/WVKK9YHAvNhRxK0md/EJ228hCsBRufyofKtW8HA=
 k8s.io/utils v0.0.0-20210305010621-2afb4311ab10 h1:u5rPykqiCpL+LBfjRkXvnK71gOgIdmq3eHUEkPrbeTI=
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 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 sigs.k8s.io/structured-merge-diff/v4 v4.0.1/go.mod h1:bJZC9H9iH24zzfZ/41RGcq60oK1F7G282QMXDPYydCw=
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--- a/csi/src/config.go
+++ b/csi/src/config.go
@ -1,22 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package vitastor
 const (
    vitastorCSIDriverName    = "csi.vitastor.io"
    vitastorCSIDriverVersion = "0.6.10"
 )
 // Config struct fills the parameters of request or user input
 type Config struct
 {
    Endpoint string
    NodeID   string
 }
 // NewConfig returns config struct to initialize new driver
 func NewConfig() *Config
 {
    return &Config{}
 }
--- a/csi/src/controllerserver.go
+++ b/csi/src/controllerserver.go
@ -1,530 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package vitastor
 import (
    "context"
    "encoding/json"
    "strings"
    "bytes"
    "strconv"
    "time"
    "fmt"
    "os"
    "os/exec"
    "io/ioutil"
    "github.com/kubernetes-csi/csi-lib-utils/protosanitizer"
    "k8s.io/klog"
    "google.golang.org/grpc/codes"
    "google.golang.org/grpc/status"
    "go.etcd.io/etcd/clientv3"
    "github.com/container-storage-interface/spec/lib/go/csi"
 )
 const (
    KB int64 = 1024
    MB int64 = 1024 * KB
    GB int64 = 1024 * MB
    TB int64 = 1024 * GB
    ETCD_TIMEOUT time.Duration = 15*time.Second
 )
 type InodeIndex struct
 {
    Id uint64 `json:"id"`
    PoolId uint64 `json:"pool_id"`
 }
 type InodeConfig struct
 {
    Name string `json:"name"`
    Size uint64 `json:"size,omitempty"`
    ParentPool uint64 `json:"parent_pool,omitempty"`
    ParentId uint64 `json:"parent_id,omitempty"`
    Readonly bool `json:"readonly,omitempty"`
 }
 type ControllerServer struct
 {
    *Driver
 }
 // NewControllerServer create new instance controller
 func NewControllerServer(driver *Driver) *ControllerServer
 {
    return &ControllerServer{
        Driver: driver,
    }
 }
 func GetConnectionParams(params map[string]string) (map[string]string, []string, string)
 {
    ctxVars := make(map[string]string)
    configPath := params["configPath"]
    if (configPath == "")
    {
        configPath = "/etc/vitastor/vitastor.conf"
    }
    else
    {
        ctxVars["configPath"] = configPath
    }
    config := make(map[string]interface{})
    if configFD, err := os.Open(configPath); err == nil
    {
        defer configFD.Close()
        data, _ := ioutil.ReadAll(configFD)
        json.Unmarshal(data, &config)
    }
    // Try to load prefix & etcd URL from the config
    var etcdUrl []string
    if (params["etcdUrl"] != "")
    {
        ctxVars["etcdUrl"] = params["etcdUrl"]
        etcdUrl = strings.Split(params["etcdUrl"], ",")
    }
    if (len(etcdUrl) == 0)
    {
        switch config["etcd_address"].(type)
        {
        case string:
            etcdUrl = strings.Split(config["etcd_address"].(string), ",")
        case []string:
            etcdUrl = config["etcd_address"].([]string)
        }
    }
    etcdPrefix := params["etcdPrefix"]
    if (etcdPrefix == "")
    {
        etcdPrefix, _ = config["etcd_prefix"].(string)
        if (etcdPrefix == "")
        {
            etcdPrefix = "/vitastor"
        }
    }
    else
    {
        ctxVars["etcdPrefix"] = etcdPrefix
    }
    return ctxVars, etcdUrl, etcdPrefix
 }
 // Create the volume
 func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest) (*csi.CreateVolumeResponse, error)
 {
    klog.Infof("received controller create volume request %+v", protosanitizer.StripSecrets(req))
    if (req == nil)
    {
        return nil, status.Errorf(codes.InvalidArgument, "request cannot be empty")
    }
    if (req.GetName() == "")
    {
        return nil, status.Error(codes.InvalidArgument, "name is a required field")
    }
    volumeCapabilities := req.GetVolumeCapabilities()
    if (volumeCapabilities == nil)
    {
        return nil, status.Error(codes.InvalidArgument, "volume capabilities is a required field")
    }
    etcdVolumePrefix := req.Parameters["etcdVolumePrefix"]
    poolId, _ := strconv.ParseUint(req.Parameters["poolId"], 10, 64)
    if (poolId == 0)
    {
        return nil, status.Error(codes.InvalidArgument, "poolId is missing in storage class configuration")
    }
    volName := etcdVolumePrefix + req.GetName()
    volSize := 1 * GB
    if capRange := req.GetCapacityRange(); capRange != nil
    {
        volSize = ((capRange.GetRequiredBytes() + MB - 1) / MB) * MB
    }
    // FIXME: The following should PROBABLY be implemented externally in a management tool
    ctxVars, etcdUrl, etcdPrefix := GetConnectionParams(req.Parameters)
    if (len(etcdUrl) == 0)
    {
        return nil, status.Error(codes.InvalidArgument, "no etcdUrl in storage class configuration and no etcd_address in vitastor.conf")
    }
    // Connect to etcd
    cli, err := clientv3.New(clientv3.Config{
        DialTimeout: ETCD_TIMEOUT,
        Endpoints: etcdUrl,
    })
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "failed to connect to etcd at "+strings.Join(etcdUrl, ",")+": "+err.Error())
    }
    defer cli.Close()
    var imageId uint64 = 0
    for
    {
        // Check if the image exists
        ctx, cancel := context.WithTimeout(context.Background(), ETCD_TIMEOUT)
        resp, err := cli.Get(ctx, etcdPrefix+"/index/image/"+volName)
        cancel()
        if (err != nil)
        {
            return nil, status.Error(codes.Internal, "failed to read key from etcd: "+err.Error())
        }
        if (len(resp.Kvs) > 0)
        {
            kv := resp.Kvs[0]
            var v InodeIndex
            err := json.Unmarshal(kv.Value, &v)
            if (err != nil)
            {
                return nil, status.Error(codes.Internal, "invalid /index/image/"+volName+" key in etcd: "+err.Error())
            }
            poolId = v.PoolId
            imageId = v.Id
            inodeCfgKey := fmt.Sprintf("/config/inode/%d/%d", poolId, imageId)
            ctx, cancel := context.WithTimeout(context.Background(), ETCD_TIMEOUT)
            resp, err := cli.Get(ctx, etcdPrefix+inodeCfgKey)
            cancel()
            if (err != nil)
            {
                return nil, status.Error(codes.Internal, "failed to read key from etcd: "+err.Error())
            }
            if (len(resp.Kvs) == 0)
            {
                return nil, status.Error(codes.Internal, "missing "+inodeCfgKey+" key in etcd")
            }
            var inodeCfg InodeConfig
            err = json.Unmarshal(resp.Kvs[0].Value, &inodeCfg)
            if (err != nil)
            {
                return nil, status.Error(codes.Internal, "invalid "+inodeCfgKey+" key in etcd: "+err.Error())
            }
            if (inodeCfg.Size < uint64(volSize))
            {
                return nil, status.Error(codes.Internal, "image "+volName+" is already created, but size is less than expected")
            }
        }
        else
        {
            // Find a free ID
            // Create image metadata in a transaction verifying that the image doesn't exist yet AND ID is still free
            maxIdKey := fmt.Sprintf("%s/index/maxid/%d", etcdPrefix, poolId)
            ctx, cancel := context.WithTimeout(context.Background(), ETCD_TIMEOUT)
            resp, err := cli.Get(ctx, maxIdKey)
            cancel()
            if (err != nil)
            {
                return nil, status.Error(codes.Internal, "failed to read key from etcd: "+err.Error())
            }
            var modRev int64
            var nextId uint64
            if (len(resp.Kvs) > 0)
            {
                var err error
                nextId, err = strconv.ParseUint(string(resp.Kvs[0].Value), 10, 64)
                if (err != nil)
                {
                    return nil, status.Error(codes.Internal, maxIdKey+" contains invalid ID")
                }
                modRev = resp.Kvs[0].ModRevision
                nextId++
            }
            else
            {
                nextId = 1
            }
            inodeIdxJson, _ := json.Marshal(InodeIndex{
                Id: nextId,
                PoolId: poolId,
            })
            inodeCfgJson, _ := json.Marshal(InodeConfig{
                Name: volName,
                Size: uint64(volSize),
            })
            ctx, cancel = context.WithTimeout(context.Background(), ETCD_TIMEOUT)
            txnResp, err := cli.Txn(ctx).If(
                clientv3.Compare(clientv3.ModRevision(fmt.Sprintf("%s/index/maxid/%d", etcdPrefix, poolId)), "=", modRev),
                clientv3.Compare(clientv3.CreateRevision(fmt.Sprintf("%s/index/image/%s", etcdPrefix, volName)), "=", 0),
                clientv3.Compare(clientv3.CreateRevision(fmt.Sprintf("%s/config/inode/%d/%d", etcdPrefix, poolId, nextId)), "=", 0),
            ).Then(
                clientv3.OpPut(fmt.Sprintf("%s/index/maxid/%d", etcdPrefix, poolId), fmt.Sprintf("%d", nextId)),
                clientv3.OpPut(fmt.Sprintf("%s/index/image/%s", etcdPrefix, volName), string(inodeIdxJson)),
                clientv3.OpPut(fmt.Sprintf("%s/config/inode/%d/%d", etcdPrefix, poolId, nextId), string(inodeCfgJson)),
            ).Commit()
            cancel()
            if (err != nil)
            {
                return nil, status.Error(codes.Internal, "failed to commit transaction in etcd: "+err.Error())
            }
            if (txnResp.Succeeded)
            {
                imageId = nextId
                break
            }
            // Start over if the transaction fails
        }
    }
    ctxVars["name"] = volName
    volumeIdJson, _ := json.Marshal(ctxVars)
    return &csi.CreateVolumeResponse{
        Volume: &csi.Volume{
            // Ugly, but VolumeContext isn't passed to DeleteVolume :-(
            VolumeId: string(volumeIdJson),
            CapacityBytes: volSize,
        },
    }, nil
 }
 // DeleteVolume deletes the given volume
 func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error)
 {
    klog.Infof("received controller delete volume request %+v", protosanitizer.StripSecrets(req))
    if (req == nil)
    {
        return nil, status.Error(codes.InvalidArgument, "request cannot be empty")
    }
    ctxVars := make(map[string]string)
    err := json.Unmarshal([]byte(req.VolumeId), &ctxVars)
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "volume ID not in JSON format")
    }
    volName := ctxVars["name"]
    _, etcdUrl, etcdPrefix := GetConnectionParams(ctxVars)
    if (len(etcdUrl) == 0)
    {
        return nil, status.Error(codes.InvalidArgument, "no etcdUrl in storage class configuration and no etcd_address in vitastor.conf")
    }
    cli, err := clientv3.New(clientv3.Config{
        DialTimeout: ETCD_TIMEOUT,
        Endpoints: etcdUrl,
    })
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "failed to connect to etcd at "+strings.Join(etcdUrl, ",")+": "+err.Error())
    }
    defer cli.Close()
    // Find inode by name
    ctx, cancel := context.WithTimeout(context.Background(), ETCD_TIMEOUT)
    resp, err := cli.Get(ctx, etcdPrefix+"/index/image/"+volName)
    cancel()
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "failed to read key from etcd: "+err.Error())
    }
    if (len(resp.Kvs) == 0)
    {
        return nil, status.Error(codes.NotFound, "volume "+volName+" does not exist")
    }
    var idx InodeIndex
    err = json.Unmarshal(resp.Kvs[0].Value, &idx)
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "invalid /index/image/"+volName+" key in etcd: "+err.Error())
    }
    // Get inode config
    inodeCfgKey := fmt.Sprintf("%s/config/inode/%d/%d", etcdPrefix, idx.PoolId, idx.Id)
    ctx, cancel = context.WithTimeout(context.Background(), ETCD_TIMEOUT)
    resp, err = cli.Get(ctx, inodeCfgKey)
    cancel()
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "failed to read key from etcd: "+err.Error())
    }
    if (len(resp.Kvs) == 0)
    {
        return nil, status.Error(codes.NotFound, "volume "+volName+" does not exist")
    }
    var inodeCfg InodeConfig
    err = json.Unmarshal(resp.Kvs[0].Value, &inodeCfg)
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "invalid "+inodeCfgKey+" key in etcd: "+err.Error())
    }
    // Delete inode data by invoking vitastor-cli
    args := []string{
        "rm-data", "--etcd_address", strings.Join(etcdUrl, ","),
        "--pool", fmt.Sprintf("%d", idx.PoolId),
        "--inode", fmt.Sprintf("%d", idx.Id),
    }
    if (ctxVars["configPath"] != "")
    {
        args = append(args, "--config_path", ctxVars["configPath"])
    }
    c := exec.Command("/usr/bin/vitastor-cli", args...)
    var stderr bytes.Buffer
    c.Stdout = nil
    c.Stderr = &stderr
    err = c.Run()
    stderrStr := string(stderr.Bytes())
    if (err != nil)
    {
        klog.Errorf("vitastor-cli rm-data failed: %s, status %s\n", stderrStr, err)
        return nil, status.Error(codes.Internal, stderrStr+" (status "+err.Error()+")")
    }
    // Delete inode config in etcd
    ctx, cancel = context.WithTimeout(context.Background(), ETCD_TIMEOUT)
    txnResp, err := cli.Txn(ctx).Then(
        clientv3.OpDelete(fmt.Sprintf("%s/index/image/%s", etcdPrefix, volName)),
        clientv3.OpDelete(fmt.Sprintf("%s/config/inode/%d/%d", etcdPrefix, idx.PoolId, idx.Id)),
    ).Commit()
    cancel()
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "failed to delete keys in etcd: "+err.Error())
    }
    if (!txnResp.Succeeded)
    {
        return nil, status.Error(codes.Internal, "failed to delete keys in etcd: transaction failed")
    }
    return &csi.DeleteVolumeResponse{}, nil
 }
 // ControllerPublishVolume return Unimplemented error
 func (cs *ControllerServer) ControllerPublishVolume(ctx context.Context, req *csi.ControllerPublishVolumeRequest) (*csi.ControllerPublishVolumeResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ControllerUnpublishVolume return Unimplemented error
 func (cs *ControllerServer) ControllerUnpublishVolume(ctx context.Context, req *csi.ControllerUnpublishVolumeRequest) (*csi.ControllerUnpublishVolumeResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ValidateVolumeCapabilities checks whether the volume capabilities requested are supported.
 func (cs *ControllerServer) ValidateVolumeCapabilities(ctx context.Context, req *csi.ValidateVolumeCapabilitiesRequest) (*csi.ValidateVolumeCapabilitiesResponse, error)
 {
    klog.Infof("received controller validate volume capability request %+v", protosanitizer.StripSecrets(req))
    if (req == nil)
    {
        return nil, status.Errorf(codes.InvalidArgument, "request is nil")
    }
    volumeID := req.GetVolumeId()
    if (volumeID == "")
    {
        return nil, status.Error(codes.InvalidArgument, "volumeId is nil")
    }
    volumeCapabilities := req.GetVolumeCapabilities()
    if (volumeCapabilities == nil)
    {
        return nil, status.Error(codes.InvalidArgument, "volumeCapabilities is nil")
    }
    var volumeCapabilityAccessModes []*csi.VolumeCapability_AccessMode
    for _, mode := range []csi.VolumeCapability_AccessMode_Mode{
        csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
        csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER,
    } {
        volumeCapabilityAccessModes = append(volumeCapabilityAccessModes, &csi.VolumeCapability_AccessMode{Mode: mode})
    }
    capabilitySupport := false
    for _, capability := range volumeCapabilities
    {
        for _, volumeCapabilityAccessMode := range volumeCapabilityAccessModes
        {
            if (volumeCapabilityAccessMode.Mode == capability.AccessMode.Mode)
            {
                capabilitySupport = true
            }
        }
    }
    if (!capabilitySupport)
    {
        return nil, status.Errorf(codes.NotFound, "%v not supported", req.GetVolumeCapabilities())
    }
    return &csi.ValidateVolumeCapabilitiesResponse{
        Confirmed: &csi.ValidateVolumeCapabilitiesResponse_Confirmed{
            VolumeCapabilities: req.VolumeCapabilities,
        },
    }, nil
 }
 // ListVolumes returns a list of volumes
 func (cs *ControllerServer) ListVolumes(ctx context.Context, req *csi.ListVolumesRequest) (*csi.ListVolumesResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // GetCapacity returns the capacity of the storage pool
 func (cs *ControllerServer) GetCapacity(ctx context.Context, req *csi.GetCapacityRequest) (*csi.GetCapacityResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ControllerGetCapabilities returns the capabilities of the controller service.
 func (cs *ControllerServer) ControllerGetCapabilities(ctx context.Context, req *csi.ControllerGetCapabilitiesRequest) (*csi.ControllerGetCapabilitiesResponse, error)
 {
    functionControllerServerCapabilities := func(cap csi.ControllerServiceCapability_RPC_Type) *csi.ControllerServiceCapability
    {
        return &csi.ControllerServiceCapability{
            Type: &csi.ControllerServiceCapability_Rpc{
                Rpc: &csi.ControllerServiceCapability_RPC{
                    Type: cap,
                },
            },
        }
    }
    var controllerServerCapabilities []*csi.ControllerServiceCapability
    for _, capability := range []csi.ControllerServiceCapability_RPC_Type{
        csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME,
        csi.ControllerServiceCapability_RPC_LIST_VOLUMES,
        csi.ControllerServiceCapability_RPC_EXPAND_VOLUME,
        csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
    } {
        controllerServerCapabilities = append(controllerServerCapabilities, functionControllerServerCapabilities(capability))
    }
    return &csi.ControllerGetCapabilitiesResponse{
        Capabilities: controllerServerCapabilities,
    }, nil
 }
 // CreateSnapshot create snapshot of an existing PV
 func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateSnapshotRequest) (*csi.CreateSnapshotResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // DeleteSnapshot delete provided snapshot of a PV
 func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteSnapshotRequest) (*csi.DeleteSnapshotResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ListSnapshots list the snapshots of a PV
 func (cs *ControllerServer) ListSnapshots(ctx context.Context, req *csi.ListSnapshotsRequest) (*csi.ListSnapshotsResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ControllerExpandVolume resizes a volume
 func (cs *ControllerServer) ControllerExpandVolume(ctx context.Context, req *csi.ControllerExpandVolumeRequest) (*csi.ControllerExpandVolumeResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // ControllerGetVolume get volume info
 func (cs *ControllerServer) ControllerGetVolume(ctx context.Context, req *csi.ControllerGetVolumeRequest) (*csi.ControllerGetVolumeResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
--- a/csi/src/grpc.go
+++ b/csi/src/grpc.go
@ -1,137 +0,0 @@
 /*
 Copyright 2017 The Kubernetes Authors.
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
 package vitastor
 import (
    "fmt"
    "net"
    "os"
    "strings"
    "sync"
    "github.com/golang/glog"
    "golang.org/x/net/context"
    "google.golang.org/grpc"
    "github.com/container-storage-interface/spec/lib/go/csi"
    "github.com/kubernetes-csi/csi-lib-utils/protosanitizer"
 )
 // Defines Non blocking GRPC server interfaces
 type NonBlockingGRPCServer interface {
    // Start services at the endpoint
    Start(endpoint string, ids csi.IdentityServer, cs csi.ControllerServer, ns csi.NodeServer)
    // Waits for the service to stop
    Wait()
    // Stops the service gracefully
    Stop()
    // Stops the service forcefully
    ForceStop()
 }
 func NewNonBlockingGRPCServer() NonBlockingGRPCServer {
    return &nonBlockingGRPCServer{}
 }
 // NonBlocking server
 type nonBlockingGRPCServer struct {
    wg     sync.WaitGroup
    server *grpc.Server
 }
 func (s *nonBlockingGRPCServer) Start(endpoint string, ids csi.IdentityServer, cs csi.ControllerServer, ns csi.NodeServer) {
    s.wg.Add(1)
    go s.serve(endpoint, ids, cs, ns)
    return
 }
 func (s *nonBlockingGRPCServer) Wait() {
    s.wg.Wait()
 }
 func (s *nonBlockingGRPCServer) Stop() {
    s.server.GracefulStop()
 }
 func (s *nonBlockingGRPCServer) ForceStop() {
    s.server.Stop()
 }
 func (s *nonBlockingGRPCServer) serve(endpoint string, ids csi.IdentityServer, cs csi.ControllerServer, ns csi.NodeServer) {
    proto, addr, err := ParseEndpoint(endpoint)
    if err != nil {
        glog.Fatal(err.Error())
    }
    if proto == "unix" {
        addr = "/" + addr
        if err := os.Remove(addr); err != nil && !os.IsNotExist(err) {
            glog.Fatalf("Failed to remove %s, error: %s", addr, err.Error())
        }
    }
    listener, err := net.Listen(proto, addr)
    if err != nil {
        glog.Fatalf("Failed to listen: %v", err)
    }
    opts := []grpc.ServerOption{
        grpc.UnaryInterceptor(logGRPC),
    }
    server := grpc.NewServer(opts...)
    s.server = server
    if ids != nil {
        csi.RegisterIdentityServer(server, ids)
    }
    if cs != nil {
        csi.RegisterControllerServer(server, cs)
    }
    if ns != nil {
        csi.RegisterNodeServer(server, ns)
    }
    glog.Infof("Listening for connections on address: %#v", listener.Addr())
    server.Serve(listener)
 }
 func ParseEndpoint(ep string) (string, string, error) {
    if strings.HasPrefix(strings.ToLower(ep), "unix://") || strings.HasPrefix(strings.ToLower(ep), "tcp://") {
        s := strings.SplitN(ep, "://", 2)
        if s[1] != "" {
            return s[0], s[1], nil
        }
    }
    return "", "", fmt.Errorf("Invalid endpoint: %v", ep)
 }
 func logGRPC(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
    glog.V(3).Infof("GRPC call: %s", info.FullMethod)
    glog.V(5).Infof("GRPC request: %s", protosanitizer.StripSecrets(req))
    resp, err := handler(ctx, req)
    if err != nil {
        glog.Errorf("GRPC error: %v", err)
    } else {
        glog.V(5).Infof("GRPC response: %s", protosanitizer.StripSecrets(resp))
    }
    return resp, err
 }
--- a/csi/src/identityserver.go
+++ b/csi/src/identityserver.go
@ -1,60 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package vitastor
 import (
    "context"
    "github.com/kubernetes-csi/csi-lib-utils/protosanitizer"
    "k8s.io/klog"
    "github.com/container-storage-interface/spec/lib/go/csi"
 )
 // IdentityServer struct of Vitastor CSI driver with supported methods of CSI identity server spec.
 type IdentityServer struct
 {
    *Driver
 }
 // NewIdentityServer create new instance identity
 func NewIdentityServer(driver *Driver) *IdentityServer
 {
    return &IdentityServer{
        Driver: driver,
    }
 }
 // GetPluginInfo returns metadata of the plugin
 func (is *IdentityServer) GetPluginInfo(ctx context.Context, req *csi.GetPluginInfoRequest) (*csi.GetPluginInfoResponse, error)
 {
    klog.Infof("received identity plugin info request %+v", protosanitizer.StripSecrets(req))
    return &csi.GetPluginInfoResponse{
        Name:          vitastorCSIDriverName,
        VendorVersion: vitastorCSIDriverVersion,
    }, nil
 }
 // GetPluginCapabilities returns available capabilities of the plugin
 func (is *IdentityServer) GetPluginCapabilities(ctx context.Context, req *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error)
 {
    klog.Infof("received identity plugin capabilities request %+v", protosanitizer.StripSecrets(req))
    return &csi.GetPluginCapabilitiesResponse{
        Capabilities: []*csi.PluginCapability{
            {
                Type: &csi.PluginCapability_Service_{
                    Service: &csi.PluginCapability_Service{
                        Type: csi.PluginCapability_Service_CONTROLLER_SERVICE,
                    },
                },
            },
        },
    }, nil
 }
 // Probe returns the health and readiness of the plugin
 func (is *IdentityServer) Probe(ctx context.Context, req *csi.ProbeRequest) (*csi.ProbeResponse, error)
 {
    return &csi.ProbeResponse{}, nil
 }
--- a/csi/src/nodeserver.go
+++ b/csi/src/nodeserver.go
@ -1,279 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package vitastor
 import (
    "context"
    "os"
    "os/exec"
    "encoding/json"
    "strings"
    "bytes"
    "google.golang.org/grpc/codes"
    "google.golang.org/grpc/status"
    "k8s.io/utils/mount"
    utilexec "k8s.io/utils/exec"
    "github.com/container-storage-interface/spec/lib/go/csi"
    "github.com/kubernetes-csi/csi-lib-utils/protosanitizer"
    "k8s.io/klog"
 )
 // NodeServer struct of Vitastor CSI driver with supported methods of CSI node server spec.
 type NodeServer struct
 {
    *Driver
    mounter mount.Interface
 }
 // NewNodeServer create new instance node
 func NewNodeServer(driver *Driver) *NodeServer
 {
    return &NodeServer{
        Driver: driver,
        mounter: mount.New(""),
    }
 }
 // NodeStageVolume mounts the volume to a staging path on the node.
 func (ns *NodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error)
 {
    return &csi.NodeStageVolumeResponse{}, nil
 }
 // NodeUnstageVolume unstages the volume from the staging path
 func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error)
 {
    return &csi.NodeUnstageVolumeResponse{}, nil
 }
 func Contains(list []string, s string) bool
 {
    for i := 0; i < len(list); i++
    {
        if (list[i] == s)
        {
            return true
        }
    }
    return false
 }
 // NodePublishVolume mounts the volume mounted to the staging path to the target path
 func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error)
 {
    klog.Infof("received node publish volume request %+v", protosanitizer.StripSecrets(req))
    targetPath := req.GetTargetPath()
    // Check that it's not already mounted
    free, error := mount.IsNotMountPoint(ns.mounter, targetPath)
    if (error != nil)
    {
        if (os.IsNotExist(error))
        {
            error := os.MkdirAll(targetPath, 0777)
            if (error != nil)
            {
                return nil, status.Error(codes.Internal, error.Error())
            }
            free = true
        }
        else
        {
            return nil, status.Error(codes.Internal, error.Error())
        }
    }
    if (!free)
    {
        return &csi.NodePublishVolumeResponse{}, nil
    }
    ctxVars := make(map[string]string)
    err := json.Unmarshal([]byte(req.VolumeId), &ctxVars)
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, "volume ID not in JSON format")
    }
    volName := ctxVars["name"]
    _, etcdUrl, etcdPrefix := GetConnectionParams(ctxVars)
    if (len(etcdUrl) == 0)
    {
        return nil, status.Error(codes.InvalidArgument, "no etcdUrl in storage class configuration and no etcd_address in vitastor.conf")
    }
    // Map NBD device
    // FIXME: Check if already mapped
    args := []string{
        "map", "--etcd_address", strings.Join(etcdUrl, ","),
        "--etcd_prefix", etcdPrefix,
        "--image", volName,
    };
    if (ctxVars["configPath"] != "")
    {
        args = append(args, "--config_path", ctxVars["configPath"])
    }
    if (req.GetReadonly())
    {
        args = append(args, "--readonly", "1")
    }
    c := exec.Command("/usr/bin/vitastor-nbd", args...)
    var stdout, stderr bytes.Buffer
    c.Stdout, c.Stderr = &stdout, &stderr
    err = c.Run()
    stdoutStr, stderrStr := string(stdout.Bytes()), string(stderr.Bytes())
    if (err != nil)
    {
        klog.Errorf("vitastor-nbd map failed: %s, status %s\n", stdoutStr+stderrStr, err)
        return nil, status.Error(codes.Internal, stdoutStr+stderrStr+" (status "+err.Error()+")")
    }
    devicePath := strings.TrimSpace(stdoutStr)
    // Check existing format
    diskMounter := &mount.SafeFormatAndMount{Interface: ns.mounter, Exec: utilexec.New()}
    existingFormat, err := diskMounter.GetDiskFormat(devicePath)
    if (err != nil)
    {
        klog.Errorf("failed to get disk format for path %s, error: %v", err)
        // unmap NBD device
        unmapOut, unmapErr := exec.Command("/usr/bin/vitastor-nbd", "unmap", devicePath).CombinedOutput()
        if (unmapErr != nil)
        {
            klog.Errorf("failed to unmap NBD device %s: %s, error: %v", devicePath, unmapOut, unmapErr)
        }
        return nil, err
    }
    // Format the device (ext4 or xfs)
    fsType := req.GetVolumeCapability().GetMount().GetFsType()
    isBlock := req.GetVolumeCapability().GetBlock() != nil
    opt := req.GetVolumeCapability().GetMount().GetMountFlags()
    opt = append(opt, "_netdev")
    if ((req.VolumeCapability.AccessMode.Mode == csi.VolumeCapability_AccessMode_MULTI_NODE_READER_ONLY ||
        req.VolumeCapability.AccessMode.Mode == csi.VolumeCapability_AccessMode_SINGLE_NODE_READER_ONLY) &&
        !Contains(opt, "ro"))
    {
        opt = append(opt, "ro")
    }
    if (fsType == "xfs")
    {
        opt = append(opt, "nouuid")
    }
    readOnly := Contains(opt, "ro")
    if (existingFormat == "" && !readOnly)
    {
        args := []string{}
        switch fsType
        {
            case "ext4":
                args = []string{"-m0", "-Enodiscard,lazy_itable_init=1,lazy_journal_init=1", devicePath}
            case "xfs":
                args = []string{"-K", devicePath}
        }
        if (len(args) > 0)
        {
            cmdOut, cmdErr := diskMounter.Exec.Command("mkfs."+fsType, args...).CombinedOutput()
            if (cmdErr != nil)
            {
                klog.Errorf("failed to run mkfs error: %v, output: %v", cmdErr, string(cmdOut))
                // unmap NBD device
                unmapOut, unmapErr := exec.Command("/usr/bin/vitastor-nbd", "unmap", devicePath).CombinedOutput()
                if (unmapErr != nil)
                {
                    klog.Errorf("failed to unmap NBD device %s: %s, error: %v", devicePath, unmapOut, unmapErr)
                }
                return nil, status.Error(codes.Internal, cmdErr.Error())
            }
        }
    }
    if (isBlock)
    {
        opt = append(opt, "bind")
        err = diskMounter.Mount(devicePath, targetPath, fsType, opt)
    }
    else
    {
        err = diskMounter.FormatAndMount(devicePath, targetPath, fsType, opt)
    }
    if (err != nil)
    {
        klog.Errorf(
            "failed to mount device path (%s) to path (%s) for volume (%s) error: %s",
            devicePath, targetPath, volName, err,
        )
        // unmap NBD device
        unmapOut, unmapErr := exec.Command("/usr/bin/vitastor-nbd", "unmap", devicePath).CombinedOutput()
        if (unmapErr != nil)
        {
            klog.Errorf("failed to unmap NBD device %s: %s, error: %v", devicePath, unmapOut, unmapErr)
        }
        return nil, status.Error(codes.Internal, err.Error())
    }
    return &csi.NodePublishVolumeResponse{}, nil
 }
 // NodeUnpublishVolume unmounts the volume from the target path
 func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error)
 {
    klog.Infof("received node unpublish volume request %+v", protosanitizer.StripSecrets(req))
    targetPath := req.GetTargetPath()
    devicePath, refCount, err := mount.GetDeviceNameFromMount(ns.mounter, targetPath)
    if (err != nil)
    {
        if (os.IsNotExist(err))
        {
            return nil, status.Error(codes.NotFound, "Target path not found")
        }
        return nil, status.Error(codes.Internal, err.Error())
    }
    if (devicePath == "")
    {
        return nil, status.Error(codes.NotFound, "Volume not mounted")
    }
    // unmount
    err = mount.CleanupMountPoint(targetPath, ns.mounter, false)
    if (err != nil)
    {
        return nil, status.Error(codes.Internal, err.Error())
    }
    // unmap NBD device
    if (refCount == 1)
    {
        unmapOut, unmapErr := exec.Command("/usr/bin/vitastor-nbd", "unmap", devicePath).CombinedOutput()
        if (unmapErr != nil)
        {
            klog.Errorf("failed to unmap NBD device %s: %s, error: %v", devicePath, unmapOut, unmapErr)
        }
    }
    return &csi.NodeUnpublishVolumeResponse{}, nil
 }
 // NodeGetVolumeStats returns volume capacity statistics available for the volume
 func (ns *NodeServer) NodeGetVolumeStats(ctx context.Context, req *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // NodeExpandVolume expanding the file system on the node
 func (ns *NodeServer) NodeExpandVolume(ctx context.Context, req *csi.NodeExpandVolumeRequest) (*csi.NodeExpandVolumeResponse, error)
 {
    return nil, status.Error(codes.Unimplemented, "")
 }
 // NodeGetCapabilities returns the supported capabilities of the node server
 func (ns *NodeServer) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error)
 {
    return &csi.NodeGetCapabilitiesResponse{}, nil
 }
 // NodeGetInfo returns NodeGetInfoResponse for CO.
 func (ns *NodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error)
 {
    klog.Infof("received node get info request %+v", protosanitizer.StripSecrets(req))
    return &csi.NodeGetInfoResponse{
        NodeId: ns.NodeID,
    }, nil
 }
--- a/csi/src/server.go
+++ b/csi/src/server.go
@ -1,36 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package vitastor
 import (
    "k8s.io/klog"
 )
 type Driver struct
 {
    *Config
 }
 // NewDriver create new instance driver
 func NewDriver(config *Config) (*Driver, error)
 {
    if (config == nil)
    {
        klog.Errorf("Vitastor CSI driver initialization failed")
        return nil, nil
    }
    driver := &Driver{
        Config: config,
    }
    klog.Infof("Vitastor CSI driver initialized")
    return driver, nil
 }
 // Start server
 func (driver *Driver) Run()
 {
    server := NewNonBlockingGRPCServer()
    server.Start(driver.Endpoint, NewIdentityServer(driver), NewControllerServer(driver), NewNodeServer(driver))
    server.Wait()
 }
--- a/csi/vitastor-csi.go
+++ b/csi/vitastor-csi.go
@ -1,39 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
 package main
 import (
    "flag"
    "fmt"
    "os"
    "k8s.io/klog"
    "vitastor.io/csi/src"
 )
 func main()
 {
    var config = vitastor.NewConfig()
    flag.StringVar(&config.Endpoint, "endpoint", "", "CSI endpoint")
    flag.StringVar(&config.NodeID, "node", "", "Node ID")
    flag.Parse()
    if (config.Endpoint == "")
    {
        config.Endpoint = os.Getenv("CSI_ENDPOINT")
    }
    if (config.NodeID == "")
    {
        config.NodeID = os.Getenv("NODE_ID")
    }
    if (config.Endpoint == "" && config.NodeID == "")
    {
        fmt.Fprintf(os.Stderr, "Please set -endpoint and -node / CSI_ENDPOINT & NODE_ID env vars\n")
        os.Exit(1)
    }
    drv, err := vitastor.NewDriver(config)
    if (err != nil)
    {
        klog.Fatalln(err)
    }
    drv.Run()
 }
--- a/debian/build-vitastor-bullseye.sh
+++ b/debian/build-vitastor-bullseye.sh
@ -1,7 +0,0 @@
 #!/bin/bash
 cat < vitastor.Dockerfile > ../Dockerfile
 cd ..
 mkdir -p packages
 sudo podman build --build-arg REL=bullseye -v `pwd`/packages:/root/packages -f Dockerfile .
 rm Dockerfile
--- a/debian/build-vitastor-buster.sh
+++ b/debian/build-vitastor-buster.sh
@ -1,7 +0,0 @@
 #!/bin/bash
 cat < vitastor.Dockerfile > ../Dockerfile
 cd ..
 mkdir -p packages
 sudo podman build --build-arg REL=buster -v `pwd`/packages:/root/packages -f Dockerfile .
 rm Dockerfile
--- a/debian/changelog
+++ b/debian/changelog
@ -1,27 +0,0 @@
 vitastor (0.6.10-1) unstable; urgency=medium
  * RDMA support
  * Bugfixes
 -- Vitaliy Filippov <vitalif@yourcmc.ru>  Sat, 01 May 2021 18:46:10 +0300
 vitastor (0.6.0-1) unstable; urgency=medium
  * Snapshots and Copy-on-Write clones
  * Image metadata in etcd (name, size)
  * Image I/O and space statistics in etcd
  * Write throttling for smoothing random write workloads in SSD+HDD configurations
 -- Vitaliy Filippov <vitalif@yourcmc.ru>  Sun, 11 Apr 2021 00:49:18 +0300
 vitastor (0.5.1-1) unstable; urgency=medium
  * Add jerasure support
 -- Vitaliy Filippov <vitalif@yourcmc.ru>  Sat, 05 Dec 2020 17:02:26 +0300
 vitastor (0.5-1) unstable; urgency=medium
  * First packaging for Debian
 -- Vitaliy Filippov <vitalif@yourcmc.ru>  Thu, 05 Nov 2020 02:20:59 +0300
--- a/debian/compat
+++ b/debian/compat
@ -1 +0,0 @@
 13
--- a/debian/control
+++ b/debian/control
@ -1,55 +0,0 @@
 Source: vitastor
 Section: admin
 Priority: optional
 Maintainer: Vitaliy Filippov <vitalif@yourcmc.ru>
 Build-Depends: debhelper, liburing-dev (>= 0.6), g++ (>= 8), libstdc++6 (>= 8), linux-libc-dev, libgoogle-perftools-dev, libjerasure-dev, libgf-complete-dev, libibverbs-dev
 Standards-Version: 4.5.0
 Homepage: https://vitastor.io/
 Rules-Requires-Root: no
 Package: vitastor
 Architecture: amd64
 Depends: vitastor-osd, vitastor-mon, vitastor-client, vitastor-client-dev, vitastor-fio
 Description: Vitastor, a fast software-defined clustered block storage
 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).
 Package: vitastor-osd
 Architecture: amd64
 Depends: ${shlibs:Depends}, ${misc:Depends}, vitastor-client (= ${binary:Version})
 Description: Vitastor, a fast software-defined clustered block storage - object storage daemon
 Vitastor object storage daemon, i.e. server program that stores data.
 Package: vitastor-mon
 Architecture: amd64
 Depends: ${misc:Depends}, nodejs (>= 10), node-sprintf-js, node-ws (>= 7), lp-solve
 Description: Vitastor, a fast software-defined clustered block storage - monitor
 Vitastor monitor, i.e. server program responsible for watching cluster state and
 scheduling cluster-level operations.
 Package: vitastor-client
 Architecture: amd64
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Description: Vitastor, a fast software-defined clustered block storage - client
 Vitastor client library and command-line interface.
 Package: vitastor-client-dev
 Section: devel
 Architecture: amd64
 Depends: ${misc:Depends}, vitastor-client (= ${binary:Version})
 Description: Vitastor, a fast software-defined clustered block storage - development files
 Vitastor library headers for development.
 Package: vitastor-fio
 Architecture: amd64
 Depends: ${shlibs:Depends}, ${misc:Depends}, vitastor-client (= ${binary:Version}), fio (= ${dep:fio})
 Description: Vitastor, a fast software-defined clustered block storage - fio drivers
 Vitastor fio drivers for benchmarking.
 Package: pve-storage-vitastor
 Architecture: amd64
 Depends: ${shlibs:Depends}, ${misc:Depends}, vitastor-client (= ${binary:Version})
 Description: Vitastor Proxmox Virtual Environment storage plugin
 Vitastor storage plugin for Proxmox Virtual Environment.
--- a/debian/copyright
+++ b/debian/copyright
@ -1,21 +0,0 @@
 Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 Upstream-Name: vitastor
 Upstream-Contact: Vitaliy Filippov <vitalif@yourcmc.ru>
 Source: https://vitastor.io
 Files: *
 Copyright: 2019+ Vitaliy Filippov <vitalif@yourcmc.ru>
 License: Multiple licenses VNPL-1.1 and/or GPL-2.0+
 All server-side code (OSD, Monitor and so on) is licensed under the terms of
 Vitastor Network Public License 1.1 (VNPL 1.1), a copyleft license based on
 GNU GPLv3.0 with the additional "Network Interaction" clause which requires
 opensourcing all programs directly or indirectly interacting with Vitastor
 through a computer network and expressly designed to be used in conjunction
 with it ("Proxy Programs"). Proxy Programs may be made public not only under
 the terms of the same license, but also under the terms of any GPL-Compatible
 Free Software License, as listed by the Free Software Foundation.
 This is a stricter copyleft license than the Affero GPL.
 .
 Client libraries (cluster_client and so on) are dual-licensed under the same
 VNPL 1.1 and also GNU GPL 2.0 or later to allow for compatibility with GPLed
 software like QEMU and fio.
--- a/debian/fio_version
+++ b/debian/fio_version
@ -1 +0,0 @@
 dep:fio=3.16-1
--- a/debian/install
+++ b/debian/install
@ -1,4 +0,0 @@
 VNPL-1.1.txt usr/share/doc/vitastor
 GPL-2.0.txt usr/share/doc/vitastor
 README.md usr/share/doc/vitastor
 README-ru.md usr/share/doc/vitastor
--- a/debian/libvirt.Dockerfile
+++ b/debian/libvirt.Dockerfile
@ -1,40 +0,0 @@
 # Build patched libvirt for Debian Buster or Bullseye/Sid inside a container
 # cd ..; podman build --build-arg REL=bullseye -v `pwd`/packages:/root/packages -f debian/libvirt.Dockerfile .
 ARG REL=
 FROM debian:$REL
 ARG REL=
 WORKDIR /root
 RUN if [ "$REL" = "buster" -o "$REL" = "bullseye" ]; then \
        echo "deb http://deb.debian.org/debian $REL-backports main" >> /etc/apt/sources.list; \
        echo >> /etc/apt/preferences; \
        echo 'Package: *' >> /etc/apt/preferences; \
        echo "Pin: release a=$REL-backports" >> /etc/apt/preferences; \
        echo 'Pin-Priority: 500' >> /etc/apt/preferences; \
    fi; \
    grep '^deb ' /etc/apt/sources.list | perl -pe 's/^deb/deb-src/' >> /etc/apt/sources.list; \
    echo 'APT::Install-Recommends false;' >> /etc/apt/apt.conf; \
    echo 'APT::Install-Suggests false;' >> /etc/apt/apt.conf
 RUN apt-get update; apt-get -y install devscripts
 RUN apt-get -y build-dep libvirt0
 RUN apt-get -y install libglusterfs-dev
 RUN apt-get --download-only source libvirt
 ADD patches/libvirt-5.0-vitastor.diff patches/libvirt-7.0-vitastor.diff patches/libvirt-7.5-vitastor.diff patches/libvirt-7.6-vitastor.diff /root
 RUN set -e; \
    mkdir -p /root/packages/libvirt-$REL; \
    rm -rf /root/packages/libvirt-$REL/*; \
    cd /root/packages/libvirt-$REL; \
    dpkg-source -x /root/libvirt*.dsc; \
    D=$(ls -d libvirt-*/); \
    V=$(ls -d libvirt-*/ | perl -pe 's/libvirt-(\d+\.\d+).*/$1/'); \
    cp /root/libvirt-$V-vitastor.diff $D/debian/patches; \
    echo libvirt-$V-vitastor.diff >> $D/debian/patches/series; \
    cd $D; \
    V=$(head -n1 debian/changelog | perl -pe 's/^.*\((.*?)(~bpo[\d\+]*)?(\+deb[u\d]+)?\).*$/$1/')+vitastor2; \
    DEBEMAIL="Vitaliy Filippov <vitalif@yourcmc.ru>" dch -D $REL -v $V 'Add Vitastor support'; \
    DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage --jobs=auto -sa; \
    rm -rf /root/packages/libvirt-$REL/$D
--- a/debian/patched-qemu.Dockerfile
+++ b/debian/patched-qemu.Dockerfile
@ -1,61 +0,0 @@
 # Build patched QEMU for Debian Buster or Bullseye/Sid inside a container
 # cd ..; podman build --build-arg REL=bullseye -v `pwd`/packages:/root/packages -f debian/patched-qemu.Dockerfile .
 ARG REL=
 FROM debian:$REL
 ARG REL=
 WORKDIR /root
 RUN if [ "$REL" = "buster" -o "$REL" = "bullseye" ]; then \
        echo "deb http://deb.debian.org/debian $REL-backports main" >> /etc/apt/sources.list; \
        echo >> /etc/apt/preferences; \
        echo 'Package: *' >> /etc/apt/preferences; \
        echo "Pin: release a=$REL-backports" >> /etc/apt/preferences; \
        echo 'Pin-Priority: 500' >> /etc/apt/preferences; \
    fi; \
    grep '^deb ' /etc/apt/sources.list | perl -pe 's/^deb/deb-src/' >> /etc/apt/sources.list; \
    echo 'APT::Install-Recommends false;' >> /etc/apt/apt.conf; \
    echo 'APT::Install-Suggests false;' >> /etc/apt/apt.conf
 RUN apt-get update
 RUN apt-get -y install qemu fio liburing1 liburing-dev libgoogle-perftools-dev devscripts
 RUN apt-get -y build-dep qemu
 # To build a custom version
 #RUN cp /root/packages/qemu-orig/* /root
 RUN apt-get --download-only source qemu
 ADD patches/qemu-5.0-vitastor.patch patches/qemu-5.1-vitastor.patch patches/qemu-6.1-vitastor.patch src/qemu_driver.c /root/vitastor/patches/
 RUN set -e; \
    apt-get install -y wget; \
    wget -q -O /etc/apt/trusted.gpg.d/vitastor.gpg https://vitastor.io/debian/pubkey.gpg; \
    (echo deb http://vitastor.io/debian $REL main > /etc/apt/sources.list.d/vitastor.list); \
    (echo "APT::Install-Recommends false;" > /etc/apt/apt.conf) && \
    apt-get update; \
    apt-get install -y vitastor-client vitastor-client-dev quilt; \
    mkdir -p /root/packages/qemu-$REL; \
    rm -rf /root/packages/qemu-$REL/*; \
    cd /root/packages/qemu-$REL; \
    dpkg-source -x /root/qemu*.dsc; \
    if ls -d /root/packages/qemu-$REL/qemu-5.0*; then \
        D=$(ls -d /root/packages/qemu-$REL/qemu-5.0*); \
        cp /root/vitastor/patches/qemu-5.0-vitastor.patch $D/debian/patches; \
        echo qemu-5.0-vitastor.patch >> $D/debian/patches/series; \
    elif ls /root/packages/qemu-$REL/qemu-6.1*; then \
        D=$(ls -d /root/packages/qemu-$REL/qemu-6.1*); \
        cp /root/vitastor/patches/qemu-6.1-vitastor.patch $D/debian/patches; \
        echo qemu-6.1-vitastor.patch >> $D/debian/patches/series; \
    else \
        cp /root/vitastor/patches/qemu-5.1-vitastor.patch /root/packages/qemu-$REL/qemu-*/debian/patches; \
        P=`ls -d /root/packages/qemu-$REL/qemu-*/debian/patches`; \
        echo qemu-5.1-vitastor.patch >> $P/series; \
    fi; \
    cd /root/packages/qemu-$REL/qemu-*/; \
    quilt push -a; \
    quilt add block/vitastor.c; \
    cp /root/vitastor/patches/qemu_driver.c block/vitastor.c; \
    quilt refresh; \
    V=$(head -n1 debian/changelog | perl -pe 's/^.*\((.*?)(~bpo[\d\+]*)?\).*$/$1/')+vitastor1; \
    DEBEMAIL="Vitaliy Filippov <vitalif@yourcmc.ru>" dch -D $REL -v $V 'Plug Vitastor block driver'; \
    DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage --jobs=auto -sa; \
    rm -rf /root/packages/qemu-$REL/qemu-*/
--- a/debian/pve-storage-vitastor.install
+++ b/debian/pve-storage-vitastor.install
@ -1 +0,0 @@
 patches/PVE_VitastorPlugin.pm usr/share/perl5/PVE/Storage/Custom/VitastorPlugin.pm
--- a/debian/raw.h
+++ b/debian/raw.h
@ -1,19 +0,0 @@
 /* Removed in Linux 5.14 */
 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 #ifndef __LINUX_RAW_H
 #define __LINUX_RAW_H
 #include <linux/types.h>
 #define RAW_SETBIND	_IO( 0xac, 0 )
 #define RAW_GETBIND	_IO( 0xac, 1 )
 struct raw_config_request 
 {
 	int	raw_minor;
 	__u64	block_major;
 	__u64	block_minor;
 };
 #endif /* __LINUX_RAW_H */
--- a/debian/rules
+++ b/debian/rules
@ -1,10 +0,0 @@
 #!/usr/bin/make -f
 export DH_VERBOSE = 1
 %:
 	dh $@
 override_dh_installdeb:
 	cat debian/fio_version >> debian/vitastor-fio.substvars
 	[ -f debian/qemu_version ] && (cat debian/qemu_version >> debian/vitastor-qemu.substvars) || true
 	dh_installdeb
--- a/debian/source/format
+++ b/debian/source/format
@ -1 +0,0 @@
 3.0 (quilt)
--- a/debian/vitastor-client-dev.install
+++ b/debian/vitastor-client-dev.install
@ -1,2 +0,0 @@
 usr/include
 usr/lib/*/pkgconfig
--- a/debian/vitastor-client.install
+++ b/debian/vitastor-client.install
@ -1,6 +0,0 @@
 usr/bin/vita
 usr/bin/vitastor-cli
 usr/bin/vitastor-rm
 usr/bin/vitastor-nbd
 usr/lib/*/libvitastor*.so*
 mon/make-osd.sh /usr/lib/vitastor
--- a/debian/vitastor-fio.install
+++ b/debian/vitastor-fio.install
@ -1 +0,0 @@
 usr/lib/*/libfio*.so*
--- a/debian/vitastor-mon.install
+++ b/debian/vitastor-mon.install
@ -1 +0,0 @@
 mon usr/lib/vitastor
--- a/debian/vitastor-osd.install
+++ b/debian/vitastor-osd.install
@ -1,2 +0,0 @@
 usr/bin/vitastor-osd
 usr/bin/vitastor-dump-journal
--- a/debian/vitastor.Dockerfile
+++ b/debian/vitastor.Dockerfile
@ -1,55 +0,0 @@
 # Build Vitastor packages for Debian Buster or Bullseye/Sid inside a container
 # cd ..; podman build --build-arg REL=bullseye -v `pwd`/packages:/root/packages -f debian/vitastor.Dockerfile .
 ARG REL=
 FROM debian:$REL
 ARG REL=
 WORKDIR /root
 RUN if [ "$REL" = "buster" -o "$REL" = "bullseye" ]; then \
        echo "deb http://deb.debian.org/debian $REL-backports main" >> /etc/apt/sources.list; \
        echo >> /etc/apt/preferences; \
        echo 'Package: *' >> /etc/apt/preferences; \
        echo "Pin: release a=$REL-backports" >> /etc/apt/preferences; \
        echo 'Pin-Priority: 500' >> /etc/apt/preferences; \
    fi; \
    grep '^deb ' /etc/apt/sources.list | perl -pe 's/^deb/deb-src/' >> /etc/apt/sources.list; \
    echo 'APT::Install-Recommends false;' >> /etc/apt/apt.conf; \
    echo 'APT::Install-Suggests false;' >> /etc/apt/apt.conf
 RUN apt-get update
 RUN apt-get -y install fio liburing1 liburing-dev libgoogle-perftools-dev devscripts
 RUN apt-get -y build-dep fio
 RUN apt-get --download-only source fio
 RUN apt-get update && apt-get -y install libjerasure-dev cmake libibverbs-dev
 ADD . /root/vitastor
 RUN set -e -x; \
    mkdir -p /root/fio-build/; \
    cd /root/fio-build/; \
    rm -rf /root/fio-build/*; \
    dpkg-source -x /root/fio*.dsc; \
    mkdir -p /root/packages/vitastor-$REL; \
    rm -rf /root/packages/vitastor-$REL/*; \
    cd /root/packages/vitastor-$REL; \
    cp -r /root/vitastor vitastor-0.6.10; \
    cd vitastor-0.6.10; \
    ln -s /root/fio-build/fio-*/ ./fio; \
    FIO=$(head -n1 fio/debian/changelog | perl -pe 's/^.*\((.*?)\).*$/$1/'); \
    ls /usr/include/linux/raw.h || cp ./debian/raw.h /usr/include/linux/raw.h; \
    sh copy-fio-includes.sh; \
    rm fio; \
    mkdir -p a b debian/patches; \
    mv fio-copy b/fio; \
    diff -NaurpbB a b > debian/patches/fio-headers.patch || true; \
    echo fio-headers.patch >> debian/patches/series; \
    rm -rf a b; \
    echo "dep:fio=$FIO" > debian/fio_version; \
    cd /root/packages/vitastor-$REL; \
    tar --sort=name --mtime='2020-01-01' --owner=0 --group=0 --exclude=debian -cJf vitastor_0.6.10.orig.tar.xz vitastor-0.6.10; \
    cd vitastor-0.6.10; \
    V=$(head -n1 debian/changelog | perl -pe 's/^.*\((.*?)\).*$/$1/'); \
    DEBFULLNAME="Vitaliy Filippov <vitalif@yourcmc.ru>" dch -D $REL -v "$V""$REL" "Rebuild for $REL"; \
    DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage --jobs=auto -sa; \
    rm -rf /root/packages/vitastor-$REL/vitastor-*/
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@ -1,9 +0,0 @@
 # Build Docker image with Vitastor packages
 FROM debian:bullseye
 ADD vitastor.list /etc/apt/sources.list.d
 ADD vitastor.gpg /etc/apt/trusted.gpg.d
 ADD vitastor.pref /etc/apt/preferences.d
 ADD apt.conf /etc/apt/
 RUN apt-get update && apt-get -y install vitastor qemu-system-x86 qemu-system-common && apt-get clean
--- a/docker/apt.conf
+++ b/docker/apt.conf
@ -1 +0,0 @@
 APT::Install-Recommends false;
--- a/docker/vitastor.gpg
+++ b/docker/vitastor.gpg
--- a/docker/vitastor.list
+++ b/docker/vitastor.list
@ -1 +0,0 @@
 deb http://vitastor.io/debian bullseye main
--- a/docker/vitastor.pref
+++ b/docker/vitastor.pref
@ -1,3 +0,0 @@
 Package: *
 Pin: origin "vitastor.io"
 Pin-Priority: 1000
--- a/src/fio_engine.cpp
+++ b/src/fio_engine.cpp
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 // FIO engine to test Blockstore
 //
 // Initialize storage for tests:
@ -25,15 +22,17 @@
 //     -bs_config='{"data_device":"./test_data.bin"}' -size=1000M
 #include "blockstore.h"
-#include "epoll_manager.h"
+extern "C" {
-#include "fio_headers.h"
+#define CONFIG_PWRITEV2
 #include "fio/fio.h"
 #include "fio/optgroup.h"
 }
 #include "json11/json11.hpp"
 struct bs_data
 {
    blockstore_t *bs;
    epoll_manager_t *epmgr;
    ring_loop_t *ringloop;
    /* The list of completed io_u structs. */
    std::vector<io_u*> completed;
@ -101,12 +100,11 @@ static void bs_cleanup(struct thread_data *td)
                bsd->ringloop->loop();
                if (bsd->bs->is_safe_to_stop())
                    goto safe;
-            } while (bsd->ringloop->has_work());
+            } while (bsd->ringloop->get_loop_again());
            bsd->ringloop->wait();
        }
    safe:
        delete bsd->bs;
        delete bsd->epmgr;
        delete bsd->ringloop;
        delete bsd;
    }
@ -132,8 +130,7 @@ static int bs_init(struct thread_data *td)
        }
    }
    bsd->ringloop = new ring_loop_t(512);
-    bsd->epmgr = new epoll_manager_t(bsd->ringloop);
+    bsd->bs = new blockstore_t(config, bsd->ringloop);
    bsd->bs = new blockstore_t(config, bsd->ringloop, bsd->epmgr->tfd);
    while (1)
    {
        bsd->ringloop->loop();
@ -292,7 +289,7 @@ static int bs_invalidate(struct thread_data *td, struct fio_file *f)
 }
 struct ioengine_ops ioengine = {
-    .name               = "vitastor_blockstore",
+    .name               = "microceph_blockstore",
    .version            = FIO_IOOPS_VERSION,
    .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
    .setup              = bs_setup,
--- a/src/fio_sec_osd.cpp
+++ b/src/fio_sec_osd.cpp
@ -1,6 +1,3 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 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
@ -8,7 +5,7 @@
 // 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 [-block_size_order=17] [-single_primary=1] -size=1000M
+//     -host=127.0.0.1 -port=11203 [-single_primary=1] -size=1000M
 //
 // Linear write:
 //
@ -28,10 +25,13 @@
 #include <vector>
 #include <unordered_map>
 #include "addr_util.h"
 #include "rw_blocking.h"
 #include "osd_ops.h"
-#include "fio_headers.h"
+extern "C" {
 #define CONFIG_PWRITEV2
 #include "fio/fio.h"
 #include "fio/optgroup.h"
 }
 struct sec_data
 {
@ -52,7 +52,6 @@ struct sec_options
    int port = 0;
    int single_primary = 0;
    int trace = 0;
    int block_order = 17;
 };
 static struct fio_option options[] = {
@ -74,15 +73,6 @@ 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",
@ -141,7 +131,6 @@ static void sec_cleanup(struct thread_data *td)
    if (bsd)
    {
        close(bsd->connect_fd);
        delete bsd;
    }
 }
@ -150,17 +139,18 @@ 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;
-    sockaddr addr;
+    struct sockaddr_in addr;
-    if (!string_to_addr(std::string(o->host ? o->host : "127.0.0.1"), false, o->port > 0 ? o->port : 11203, &addr))
+    int r;
    if ((r = inet_pton(AF_INET, o->host ? o->host : "127.0.0.1", &addr.sin_addr)) != 1)
    {
-        fprintf(stderr, "server address: %s is not valid\n", o->host ? o->host : "127.0.0.1");
+        fprintf(stderr, "server address: %s%s\n", o->host ? o->host : "127.0.0.1", r == 0 ? " is not valid" : ": no ipv4 support");
        return 1;
    }
    addr.sin_family = AF_INET;
    addr.sin_port = htons(o->port ? o->port : 11203);
-    bsd->connect_fd = socket(addr.sa_family, SOCK_STREAM, 0);
+    bsd->connect_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (bsd->connect_fd < 0)
    {
        perror("socket");
@ -202,7 +192,7 @@ 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_SEC_READ;
+            op.hdr.opcode = OSD_OP_SECONDARY_READ;
            op.sec_rw.oid = {
                .inode = 1,
                .stripe = io->offset >> bsd->block_order,
@ -223,7 +213,7 @@ 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_SEC_WRITE;
+            op.hdr.opcode = OSD_OP_SECONDARY_WRITE;
            op.sec_rw.oid = {
                .inode = 1,
                .stripe = io->offset >> bsd->block_order,
@ -271,18 +261,15 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
    bsd->op_n++;
    bsd->queue[n] = io;
-    iovec iov[2] = { { .iov_base = op.buf, .iov_len = OSD_PACKET_SIZE } };
+    if (write(bsd->connect_fd, op.buf, OSD_PACKET_SIZE) != OSD_PACKET_SIZE)
-    int iovcnt = 1, wtotal = OSD_PACKET_SIZE;
+    {
        perror("write");
        exit(1);
    }
    if (io->ddir == DDIR_WRITE)
    {
-        iov[1] = { .iov_base = io->xfer_buf, .iov_len = io->xfer_buflen };
+        // Send data
-        wtotal += io->xfer_buflen;
+        write_blocking(bsd->connect_fd, io->xfer_buf, io->xfer_buflen);
        iovcnt++;
    }
    if (writev_blocking(bsd->connect_fd, iov, iovcnt) != wtotal)
    {
        perror("writev");
        exit(1);
    }
    if (io->error != 0)
@ -311,7 +298,6 @@ static int sec_getevents(struct thread_data *td, unsigned int min, unsigned int
            exit(1);
        }
        io_u* io = it->second;
        bsd->queue.erase(it);
        if (io->ddir == DDIR_READ)
        {
            if (reply.hdr.retval != io->xfer_buflen)
@ -379,7 +365,7 @@ static int sec_invalidate(struct thread_data *td, struct fio_file *f)
 }
 struct ioengine_ops ioengine = {
-    .name               = "vitastor_secondary_osd",
+    .name               = "microceph_secondary_osd",
    .version            = FIO_IOOPS_VERSION,
    .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
    .setup              = sec_setup,
--- a/1
+++ b/1
@ -1 +0,0 @@
 Subproject commit 55363fc2653b8802637a3d2e73a06839a72c585d
--- a/lambda_size.cpp
+++ b/lambda_size.cpp
@ -0,0 +1,48 @@
 #include <iostream>
 #include <functional>
 #include <array>
 #include <cstdlib> // for malloc() and free()
 using namespace std;
 // replace operator new and delete to log allocations
 void* operator new(std::size_t n)
 {
    cout << "Allocating " << n << " bytes" << endl;
    return malloc(n);
 }
 void operator delete(void* p) throw()
 {
    free(p);
 }
 class test
 {
 public:
    std::string s;
    void a(std::function<void()> & f, const char *str)
    {
        auto l = [this, str]() { cout << str << " ? " << s << " from this\n"; };
        cout << "Assigning lambda3 of size " << sizeof(l) << endl;
        f = l;
    }
 };
 int main()
 {
    std::array<char, 16> arr1;
    auto lambda1 = [arr1](){};
    cout << "Assigning lambda1 of size " << sizeof(lambda1) << endl;
    std::function<void()> f1 = lambda1;
    std::array<char, 17> arr2;
    auto lambda2 = [arr2](){};
    cout << "Assigning lambda2 of size " << sizeof(lambda2) << endl;
    std::function<void()> f2 = lambda2;
    test t;
    std::function<void()> f3;
    t.s = "str";
    t.a(f3, "huyambda");
    f3();
 }
--- a/mon/PGUtil.js
+++ b/mon/PGUtil.js
@ -1,104 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 module.exports = {
    scale_pg_count,
 };
 function add_pg_history(new_pg_history, new_pg, prev_pgs, prev_pg_history, old_pg)
 {
    if (!new_pg_history[new_pg])
    {
        new_pg_history[new_pg] = {
            osd_sets: {},
            all_peers: {},
            epoch: 0,
        };
    }
    const nh = new_pg_history[new_pg], oh = prev_pg_history[old_pg];
    nh.osd_sets[prev_pgs[old_pg].join(' ')] = prev_pgs[old_pg];
    if (oh && oh.osd_sets && oh.osd_sets.length)
    {
        for (const pg of oh.osd_sets)
        {
            nh.osd_sets[pg.join(' ')] = pg;
        }
    }
    if (oh && oh.all_peers && oh.all_peers.length)
    {
        for (const osd_num of oh.all_peers)
        {
            nh.all_peers[osd_num] = Number(osd_num);
        }
    }
    if (oh && oh.epoch)
    {
        nh.epoch = nh.epoch < oh.epoch ? oh.epoch : nh.epoch;
    }
 }
 function finish_pg_history(merged_history)
 {
    merged_history.osd_sets = Object.values(merged_history.osd_sets);
    merged_history.all_peers = Object.values(merged_history.all_peers);
 }
 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 to the history of new PGs
    if (!(new_pg_count % old_pg_count))
    {
        // New PG count is a multiple of old PG count
        for (let i = 0; i < new_pg_count; i++)
        {
            add_pg_history(new_pg_history, i, prev_pgs, prev_pg_history, i % old_pg_count);
            finish_pg_history(new_pg_history[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++)
        {
            for (let j = 0; j < mul; j++)
            {
                add_pg_history(new_pg_history, i, prev_pgs, prev_pg_history, i+j*new_pg_count);
            }
            finish_pg_history(new_pg_history[i]);
        }
    }
    else
    {
        // Any PG may intersect with any PG after non-multiple PG count change
        // So, merge ALL PGs history
        let merged_history = {};
        for (let i = 0; i < old_pg_count; i++)
        {
            add_pg_history(merged_history, 1, prev_pgs, prev_pg_history, i);
        }
        finish_pg_history(merged_history[1]);
        for (let i = 0; i < new_pg_count; i++)
        {
            new_pg_history[i] = { ...merged_history[1] };
        }
    }
    // Mark history keys for removed PGs as removed
    for (let i = new_pg_count; i < old_pg_count; i++)
    {
        new_pg_history[i] = null;
    }
    // Just for the lp_solve optimizer - pick a "previous" PG for each "new" one
    if (old_pg_count < new_pg_count)
    {
        for (let i = old_pg_count; i < new_pg_count; i++)
        {
            prev_pgs[i] = prev_pgs[i % old_pg_count];
        }
    }
    else if (old_pg_count > new_pg_count)
    {
        prev_pgs.splice(new_pg_count, old_pg_count-new_pg_count);
    }
 }
--- a/mon/afr.js
+++ b/mon/afr.js
@ -1,89 +0,0 @@
 // 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-1.1 (see https://yourcmc.ru/git/vitalif/vitastor/src/branch/master/README.md for details) or AGPL-3.0
 // Author: Vitaliy Filippov, 2020+
 module.exports = {
    cluster_afr_fullmesh,
    failure_rate_fullmesh,
    cluster_afr,
    c_n_k,
 };
 /******** "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 (~50 for 100 PG-per-OSD in a big cluster)
 //
 // 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 (degraded_replacement=false).
 // At the same time, more peers per OSD increase probability of any of them to fail!
 // osd_rm=true means that failed OSDs' data is rebalanced over all other hosts,
 // not over the same host as it's in Ceph by default (dead OSDs are marked 'out').
 //
 // 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({ n_hosts, n_drives, afr_drive, afr_host, capacity, speed, ec, ec_data, ec_parity, replicas, pgs = 1, osd_rm, degraded_replacement, down_out_interval = 600 })
 {
    const pg_size = (ec ? ec_data+ec_parity : replicas);
    pgs = Math.min(pgs, (n_hosts-1)*n_drives/(pg_size-1));
    const host_pgs = Math.min(pgs*n_drives, (n_hosts-1)*n_drives/(pg_size-1));
    const resilver_disk = n_drives == 1 || osd_rm ? pgs : (n_drives-1);
    const disk_heal_time = (down_out_interval + capacity/(degraded_replacement ? 1 : resilver_disk)/speed)/86400/365;
    const host_heal_time = (down_out_interval + n_drives*capacity/pgs/speed)/86400/365;
    const disk_heal_fail = ((afr_drive+afr_host/n_drives)*disk_heal_time);
    const host_heal_fail = ((afr_drive+afr_host/n_drives)*host_heal_time);
    const disk_pg_fail = ec
        ? failure_rate_fullmesh(ec_data+ec_parity-1, disk_heal_fail, ec_parity)
        : disk_heal_fail**(replicas-1);
    const host_pg_fail = ec
        ? failure_rate_fullmesh(ec_data+ec_parity-1, host_heal_fail, ec_parity)
        : host_heal_fail**(replicas-1);
    return 1 - ((1 - afr_drive * (1-(1-disk_pg_fail)**pgs)) ** (n_hosts*n_drives))
        * ((1 - afr_host * (1-(1-host_pg_fail)**host_pgs)) ** n_hosts);
 }
 /******** 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;
 }
--- a/mon/afr_test.js
+++ b/mon/afr_test.js
@ -1,28 +0,0 @@
 const { sprintf } = require('sprintf-js');
 const { cluster_afr } = require('./afr.js');
 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, afr_host: 0, 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, afr_host: 0, capacity: 4000, speed: 0.1, ec: true, ec_data: 2, ec_parity: 1 });
 print_cluster_afr({ n_hosts: 4, n_drives: 3, afr_drive: 0.03, afr_host: 0.05, capacity: 4000, speed: 0.1, ec: true, ec_data: 2, ec_parity: 1 });
 print_cluster_afr({ n_hosts: 10, n_drives: 10, afr_drive: 0.1, afr_host: 0, 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, afr_host: 0, 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, afr_host: 0, 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 });
 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 ${config.ec_data}+${config.ec_parity}` : `, ${config.replicas} replicas`)+
        `, ${config.pgs||1} PG per OSD`+
        (config.degraded_replacement ? `\n...and you don't let the rebalance finish before replacing drives` : '')
    );
    console.log('-> '+sprintf("%.7f%%", 100*cluster_afr(config))+'\n');
 }
--- a/mon/lp-optimizer.js
+++ b/mon/lp-optimizer.js
@ -1,729 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 // Data distribution optimizer using linear programming (lp_solve)
 const child_process = require('child_process');
 const NO_OSD = 'Z';
 async function lp_solve(text)
 {
    const cp = child_process.spawn('lp_solve');
    let stdout = '', stderr = '', finish_cb;
    cp.stdout.on('data', buf => stdout += buf.toString());
    cp.stderr.on('data', buf => stderr += buf.toString());
    cp.on('exit', () => finish_cb && finish_cb());
    cp.stdin.write(text);
    cp.stdin.end();
    if (cp.exitCode == null)
    {
        await new Promise(ok => finish_cb = ok);
    }
    if (!stdout.trim())
    {
        return null;
    }
    let score = 0;
    let vars = {};
    for (const line of stdout.split(/\n/))
    {
        let m = /^(^Value of objective function: (-?[\d\.]+)|Actual values of the variables:)\s*$/.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, round_robin = false })
 {
    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, parity_space > 1));
    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, round_robin);
    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 shuffle(array)
 {
    for (let i = array.length - 1, j, x; i > 0; i--)
    {
        j = Math.floor(Math.random() * (i + 1));
        x = array[i];
        array[i] = array[j];
        array[j] = x;
    }
 }
 function make_int_pgs(weights, pg_count, round_robin)
 {
    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 cur_pg = pg_name.substr(3).split('_');
        let n = Math.round(weights[pg_name] / weight_left * pg_left);
        for (let i = 0; i < n; i++)
        {
            int_pgs.push([ ...cur_pg ]);
            if (round_robin)
            {
                cur_pg.push(cur_pg.shift());
            }
        }
        weight_left -= weights[pg_name];
        pg_left -= n;
    }
    shuffle(int_pgs);
    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;
    }
    // FIXME: use parity_chunks with parity_space instead of pg_minsize
    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, parity_space > 1);
    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;
 }
 // ordered = don't treat (x,y) and (y,x) as equal
 function random_combinations(osd_tree, pg_size, count, ordered)
 {
    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);
            }
            const cyclic_pgs = [ pg ];
            if (ordered)
            {
                for (let i = 1; i < pg.size; i++)
                {
                    cyclic_pgs.push([ ...pg.slice(i), ...pg.slice(0, i) ]);
                }
            }
            for (const pg of cyclic_pgs)
            {
                while (pg.length < pg_size)
                {
                    pg.push(NO_OSD);
                }
                r['pg_'+pg.join('_')] = pg;
            }
        }
    }
    // Generate purely random combinations
    while (count > 0)
    {
        let host_idx = [];
        const cur_hosts = [ ...hosts.map((h, i) => i) ];
        const max_hosts = pg_size < hosts.length ? pg_size : hosts.length;
        if (ordered)
        {
            for (let i = 0; i < max_hosts; i++)
            {
                const r = rng() % cur_hosts.length;
                host_idx[i] = cur_hosts[r];
                cur_hosts.splice(r, 1);
            }
        }
        else
        {
            for (let i = 0; i < max_hosts; i++)
            {
                const r = rng() % (cur_hosts.length - (max_hosts - i - 1));
                host_idx[i] = cur_hosts[r];
                cur_hosts.splice(0, r+1);
            }
        }
        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,
 };
--- a/mon/make-osd.sh
+++ b/mon/make-osd.sh
@ -1,62 +0,0 @@
 #!/bin/bash
 # Very simple systemd unit generator for vitastor-osd services
 # Not the final solution yet, mostly for tests
 # Copyright (c) Vitaliy Filippov, 2019+
 # License: MIT
 # USAGE:
 # 1) Put etcd_address and osd_network into /etc/vitastor/vitastor.conf. Example:
 #    {
 #        "etcd_address":["http://10.200.1.10:2379/v3","http://10.200.1.11:2379/v3","http://10.200.1.12:2379/v3"],
 #        "osd_network":"10.200.1.0/24"
 #    }
 # 2) Run ./make-osd.sh /dev/disk/by-partuuid/xxx [ /dev/disk/by-partuuid/yyy]...
 set -e -x
 # Create OSDs on all passed devices
 for DEV in $*; do
 OSD_NUM=$(vitastor-cli alloc-osd)
 echo Creating OSD $OSD_NUM on $DEV
 OPT=$(vitastor-cli simple-offsets --format options $DEV | tr '\n' ' ')
 META=$(vitastor-cli simple-offsets --format json $DEV | jq .data_offset)
 dd if=/dev/zero of=$DEV bs=1048576 count=$(((META+1048575)/1048576)) oflag=direct
 cat >/etc/systemd/system/vitastor-osd$OSD_NUM.service <<EOF
 [Unit]
 Description=Vitastor object storage daemon osd.$OSD_NUM
 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=/usr/bin/vitastor-osd \\
    --osd_num $OSD_NUM \\
    --disable_data_fsync 1 \\
    --immediate_commit all \\
    --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096 \\
    --journal_no_same_sector_overwrites true \\
    --journal_sector_buffer_count 1024 \\
    $OPT
 WorkingDirectory=/
 ExecStartPre=+chown vitastor:vitastor $DEV
 User=vitastor
 PrivateTmp=false
 TasksMax=infinity
 Restart=always
 StartLimitInterval=0
 RestartSec=10
 [Install]
 WantedBy=vitastor.target
 EOF
 systemctl enable vitastor-osd$OSD_NUM
 done
--- a/mon/make-units.sh
+++ b/mon/make-units.sh
@ -1,86 +0,0 @@
 #!/bin/bash
 # Very simple systemd unit generator for etcd & vitastor-mon services
 # Not the final solution yet, mostly for tests
 # Copyright (c) Vitaliy Filippov, 2019+
 # License: MIT
 # USAGE: ./make-units.sh
 IP_SUBSTR="10.200.1."
 ETCD_HOSTS="etcd0=http://10.200.1.10:2380,etcd1=http://10.200.1.11:2380,etcd2=http://10.200.1.12:2380"
 # determine IP
 IP=`ip -json a s | jq -r '.[].addr_info[] | select(.local | startswith("'$IP_SUBSTR'")) | .local'`
 [ "$IP" != "" ] || exit 1
 ETCD_NUM=${ETCD_HOSTS/$IP*/}
 [ "$ETCD_NUM" != "$ETCD_HOSTS" ] || exit 1
 ETCD_NUM=$(echo $ETCD_NUM | tr -d -c , | wc -c)
 # etcd
 useradd etcd
 mkdir -p /var/lib/etcd$ETCD_NUM.etcd
 cat >/etc/systemd/system/etcd.service <<EOF
 [Unit]
 Description=etcd for vitastor
 After=network-online.target local-fs.target time-sync.target
 Wants=network-online.target local-fs.target time-sync.target
 [Service]
 Restart=always
 ExecStart=/usr/local/bin/etcd -name etcd$ETCD_NUM --data-dir /var/lib/etcd$ETCD_NUM.etcd \\
    --advertise-client-urls http://$IP:2379 --listen-client-urls http://$IP:2379 \\
    --initial-advertise-peer-urls http://$IP:2380 --listen-peer-urls http://$IP:2380 \\
    --initial-cluster-token vitastor-etcd-1 --initial-cluster $ETCD_HOSTS \\
    --initial-cluster-state new --max-txn-ops=100000 --max-request-bytes=104857600 \\
    --auto-compaction-retention=10 --auto-compaction-mode=revision
 WorkingDirectory=/var/lib/etcd$ETCD_NUM.etcd
 ExecStartPre=+chown -R etcd /var/lib/etcd$ETCD_NUM.etcd
 User=etcd
 PrivateTmp=false
 TasksMax=infinity
 Restart=always
 StartLimitInterval=0
 RestartSec=10
 [Install]
 WantedBy=local.target
 EOF
 systemctl daemon-reload
 systemctl enable etcd
 systemctl start etcd
 useradd vitastor
 chmod 755 /root
 # Vitastor target
 cat >/etc/systemd/system/vitastor.target <<EOF
 [Unit]
 Description=vitastor target
 [Install]
 WantedBy=multi-user.target
 EOF
 # Monitor unit
 ETCD_MON=$(echo $ETCD_HOSTS | perl -pe 's/:2380/:2379/g; s/etcd\d*=//g;')
 cat >/etc/systemd/system/vitastor-mon.service <<EOF
 [Unit]
 Description=Vitastor monitor
 After=network-online.target local-fs.target time-sync.target
 Wants=network-online.target local-fs.target time-sync.target
 [Service]
 Restart=always
 ExecStart=node /usr/lib/vitastor/mon/mon-main.js --etcd_url '$ETCD_MON' --etcd_prefix '/vitastor' --etcd_start_timeout 5
 WorkingDirectory=/
 User=vitastor
 PrivateTmp=false
 TasksMax=infinity
 Restart=always
 StartLimitInterval=0
 RestartSec=10
 [Install]
 WantedBy=vitastor.target
 EOF
--- a/mon/merge.js
+++ b/mon/merge.js
@ -1,23 +0,0 @@
 const fsp = require('fs').promises;
 async function merge(file1, file2, out)
 {
    if (!out)
    {
        console.error('USAGE: nodejs merge.js layer1 layer2 output');
        process.exit();
    }
    const layer1 = await fsp.readFile(file1);
    const layer2 = await fsp.readFile(file2);
    const zero = Buffer.alloc(4096);
    for (let i = 0; i < layer2.length; i += 4096)
    {
        if (zero.compare(layer2, i, i+4096) != 0)
        {
            layer2.copy(layer1, i, i, i+4096);
        }
    }
    await fsp.writeFile(out, layer1);
 }
 merge(process.argv[2], process.argv[3], process.argv[4]);
--- a/mon/mon-main.js
+++ b/mon/mon-main.js
@ -1,26 +0,0 @@
 #!/usr/bin/node
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (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] === '-h' || process.argv[i] === '--help')
    {
        console.error('USAGE: '+process.argv[0]+' '+process.argv[1]+' [--verbose 1]'+
            ' [--etcd_address "http://127.0.0.1:2379,..."] [--config_file /etc/vitastor/vitastor.conf]'+
            ' [--etcd_prefix "/vitastor"] [--etcd_start_timeout 5]');
        process.exit();
    }
    else if (process.argv[i].substr(0, 2) == '--')
    {
        options[process.argv[i].substr(2)] = process.argv[i+1];
        i++;
    }
 }
 new Mon(options).start().catch(e => { console.error(e); process.exit(1); });
--- a/mon/mon.js
+++ b/mon/mon.js
--- a/mon/package.json
+++ b/mon/package.json
@ -1,15 +0,0 @@
 {
  "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"
  }
 }
--- a/mon/simple-offsets.js
+++ b/mon/simple-offsets.js
@ -1,96 +0,0 @@
 // 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 fs = require('fs').promises;
 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,
        format: 'text',
    };
    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.device)
    {
        process.stderr.write('USAGE: nodejs '+process.argv[1]+' --device /dev/sdXXX\n');
        process.exit(1);
    }
    options.device_size = Number(options.device_size);
    let device_size = options.device_size;
    if (!device_size)
    {
        const st = await fs.stat(options.device);
        options.device_block_size = st.blksize;
        if (st.isBlockDevice())
            device_size = Number(await system("/sbin/blockdev --getsize64 "+options.device))
        else
            device_size = st.size;
    }
    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 + 2*options.object_size/options.bitmap_granularity/8));
    const object_count = Math.floor((device_size-meta_offset)/options.object_size);
    const meta_size = Math.ceil(1 + 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");
    if (options.format == 'text' || options.format == 'options')
    {
        if (options.format == 'text')
        {
            process.stderr.write(
                `Metadata size: ${meta_size_fmt}\n`+
                `Options for the OSD:\n`
            );
        }
        process.stdout.write(
            (options.device_block_size != 4096 ?
                `    --meta_block_size ${options.device}\n`+
                `    --journal_block-size ${options.device}\n` : '')+
            `    --data_device ${options.device}\n`+
            `    --journal_offset ${options.journal_offset}\n`+
            `    --meta_offset ${meta_offset}\n`+
            `    --data_offset ${data_offset}\n`+
            (options.device_size ? `    --data_size ${device_size-data_offset}\n` : '')
        );
    }
    else if (options.format == 'env')
    {
        process.stdout.write(
            `journal_offset=${options.journal_offset}\n`+
            `meta_offset=${meta_offset}\n`+
            `data_offset=${data_offset}\n`+
            `data_size=${device_size-data_offset}\n`
        );
    }
    else
        process.stdout.write('Unknown format: '+options.format);
 }
 function system(cmd)
 {
    return new Promise((ok, no) => child_process.exec(cmd, { maxBuffer: 64*1024*1024 }, (err, stdout, stderr) => (err ? no(err.message) : ok(stdout))));
 }
 run().catch(err => { console.error(err); process.exit(1); });
--- a/mon/stable-stringify.js
+++ b/mon/stable-stringify.js
@ -1,78 +0,0 @@
 // 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;
--- a/mon/test-nonuniform.js
+++ b/mon/test-nonuniform.js
@ -1,130 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (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);
--- a/mon/test-optimize-simple.js
+++ b/mon/test-optimize-simple.js
@ -1,25 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (see README.md for details)
 const LPOptimizer = require('./lp-optimizer.js');
 async function run()
 {
    const osd_tree = { a: { 1: 1 }, b: { 2: 1 }, c: { 3: 1 } };
    let res;
    console.log('16 PGs, size=3');
    res = await LPOptimizer.optimize_initial({ osd_tree, pg_size: 3, pg_count: 16 });
    LPOptimizer.print_change_stats(res, false);
    console.log('\nReduce PG size to 2');
    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs.map(pg => pg.slice(0, 2)), osd_tree, pg_size: 2 });
    LPOptimizer.print_change_stats(res, false);
    console.log('\nRemove OSD 3');
    delete osd_tree['c'];
    res = await LPOptimizer.optimize_change({ prev_pgs: res.int_pgs, osd_tree, pg_size: 2 });
    LPOptimizer.print_change_stats(res, false);
 }
 run().catch(console.error);
--- a/mon/test-optimize-undersized.js
+++ b/mon/test-optimize-undersized.js
@ -1,74 +0,0 @@
 // Copyright (c) Vitaliy Filippov, 2019+
 // License: VNPL-1.1 (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);
--- a/Show More
+++ b/Show More
		`@ -1 +0,0 @@`
			`Subproject commit 5dc108754ad40d3b1d024f9bd7cca0595ef1a1db`
		`@ -1 +0,0 @@`
			`patches/PVE_VitastorPlugin.pm usr/share/perl5/PVE/Storage/Custom/VitastorPlugin.pm`
		`@ -1,2 +0,0 @@`
			`usr/bin/vitastor-osd`
			`usr/bin/vitastor-dump-journal`
		`@ -1 +0,0 @@`
			`Subproject commit 55363fc2653b8802637a3d2e73a06839a72c585d`