Commit Graph

59 Commits (master)

Author SHA1 Message Date
Kevin Wolf a4b740db5e block: Take graph lock for most of .bdrv_open
Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08 17:56:18 +01:00
Kevin Wolf 018f9dea9c block: Mark bdrv_apply_auto_read_only() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_apply_auto_read_only() need to hold a reader lock for the graph
because it calls bdrv_can_set_read_only(), which indirectly accesses the
parents list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-19-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00
Paolo Bonzini e7918e9619 bochs: mark more functions as coroutine_fns and GRAPH_RDLOCK
Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend.  Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-5-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28 09:46:24 +02:00
Kevin Wolf b9b10c35e5 block: Mark public read/write functions GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23 19:49:17 +01:00
Markus Armbruster e2c1c34f13 include/block: Untangle inclusion loops
We have two inclusion loops:

       block/block.h
    -> block/block-global-state.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

       block/block.h
    -> block/block-io.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2023-01-20 07:24:28 +01:00
Vladimir Sementsov-Ogievskiy 8393078032 block: introduce bdrv_open_file_child() helper
Almost all drivers call bdrv_open_child() similarly. Let's create a
helper for this.

The only not updated drivers that call bdrv_open_child() to set
bs->file are raw-format and snapshot-access:
    raw-format sometimes want to have filtered child but
        don't set drv->is_filter to true.
    snapshot-access wants only DATA | PRIMARY

Possibly we should implement drv->is_filter_func() handler, to consider
raw-format as filter when it works as filter.. But it's another story.

Note also, that we decrease assignments to bs->file in code: it helps
us restrict modifying this field in further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Alberto Faria 32cc71def9 block: Change bdrv_{pread,pwrite,pwrite_sync}() param order
Swap 'buf' and 'bytes' around for consistency with
bdrv_co_{pread,pwrite}(), and in preparation to implement these
functions using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pread(child, offset, buf, bytes, flags)
    + bdrv_pread(child, offset, bytes, buf, flags)

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pwrite(child, offset, buf, bytes, flags)
    + bdrv_pwrite(child, offset, bytes, buf, flags)

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pwrite_sync(child, offset, buf, bytes, flags)
    + bdrv_pwrite_sync(child, offset, bytes, buf, flags)

Resulting overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220609152744.3891847-3-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:55 +02:00
Alberto Faria 53fb7844f0 block: Add a 'flags' param to bdrv_{pread,pwrite,pwrite_sync}()
For consistency with other I/O functions, and in preparation to
implement them using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pread(child, offset, buf, bytes)
    + bdrv_pread(child, offset, buf, bytes, 0)

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pwrite(child, offset, buf, bytes)
    + bdrv_pwrite(child, offset, buf, bytes, 0)

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pwrite_sync(child, offset, buf, bytes)
    + bdrv_pwrite_sync(child, offset, buf, bytes, 0)

Resulting overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220609152744.3891847-2-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:55 +02:00
Vladimir Sementsov-Ogievskiy f7ef38dd13 block: use int64_t instead of uint64_t in driver read handlers
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver read handlers parameters which are already 64bit to
signed type.

While being here, convert also flags parameter to be BdrvRequestFlags.

Now let's consider all callers. Simple

  git grep '\->bdrv_\(aio\|co\)_preadv\(_part\)\?'

shows that's there three callers of driver function:

 bdrv_driver_preadv() in block/io.c, passes int64_t, checked by
   bdrv_check_qiov_request() to be non-negative.

 qcow2_load_vmstate() does bdrv_check_qiov_request().

 do_perform_cow_read() has uint64_t argument. And a lot of things in
 qcow2 driver are uint64_t, so converting it is big job. But we must
 not work with requests that don't satisfy bdrv_check_qiov_request(),
 so let's just assert it here.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_\(aio\|co\)_preadv\(_part\)\?\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

The only one such caller:

    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1);
    ...
    ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0);

in tests/unit/test-bdrv-drain.c, and it's OK obviously.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix typos]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29 13:46:31 -05:00
Max Reitz 69dca43d6b block: Use bdrv_default_perms()
bdrv_default_perms() can decide which permission profile to use based on
the BdrvChildRole, so block drivers do not need to select it explicitly.

The blkverify driver now no longer shares the WRITE permission for the
image to verify.  We thus have to adjust two places in
test-block-iothread not to take it.  (Note that in theory, blkverify
should behave like quorum in this regard and share neither WRITE nor
RESIZE for both of its children.  In practice, it does not really
matter, because blkverify is used only for debugging, so we might as
well keep its permissions rather liberal.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-30-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz 8b1869daad block: Make format drivers use child_of_bds
Commonly, they need to pass the BDRV_CHILD_IMAGE set as the
BdrvChildRole; but there are exceptions for drivers with external data
files (qcow2 and vmdk).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-26-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz 258b776515 block: Add BdrvChildRole to BdrvChild
For now, it is always set to 0.  Later patches in this series will
ensure that all callers pass an appropriate combination of flags.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz d67066d8bc block: Add BlockDriver.is_format
We want to unify child_format and child_file at some point.  One of the
important things that set format drivers apart from other drivers is
that they do not expect other format nodes under them (except in the
backing chain), i.e. we must not probe formats inside of formats.  That
means we need something on which to distinguish format drivers from
others, and hence this flag.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Nir Soffer 1bbbf32d5f block: Use QEMU_IS_ALIGNED
Replace instances of:

    (n & (BDRV_SECTOR_SIZE - 1)) == 0

And:

   (n & ~BDRV_SECTOR_MASK) == 0

With:

    QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)

Which reveals the intent of the code better, and makes it easier to
locate the code checking alignment.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827185913.27427-2-nsoffer@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-16 14:48:30 +02:00
Markus Armbruster a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Paolo Bonzini 7d37435bd5 avoid TABs in files that only contain a few
Most files that have TABs only contain a handful of them.  Change
them to spaces so that we don't confuse people.

disas, standard-headers, linux-headers and libdecnumber are imported
from other projects and probably should be exempted from the check.
Outside those, after this patch the following files still contain both
8-space and TAB sequences at the beginning of the line.  Many of them
have a majority of TABs, or were initially committed with all tabs.

    bsd-user/i386/target_syscall.h
    bsd-user/x86_64/target_syscall.h
    crypto/aes.c
    hw/audio/fmopl.c
    hw/audio/fmopl.h
    hw/block/tc58128.c
    hw/display/cirrus_vga.c
    hw/display/xenfb.c
    hw/dma/etraxfs_dma.c
    hw/intc/sh_intc.c
    hw/misc/mst_fpga.c
    hw/net/pcnet.c
    hw/sh4/sh7750.c
    hw/timer/m48t59.c
    hw/timer/sh_timer.c
    include/crypto/aes.h
    include/disas/bfd.h
    include/hw/sh4/sh.h
    libdecnumber/decNumber.c
    linux-headers/asm-generic/unistd.h
    linux-headers/linux/kvm.h
    linux-user/alpha/target_syscall.h
    linux-user/arm/nwfpe/double_cpdo.c
    linux-user/arm/nwfpe/fpa11_cpdt.c
    linux-user/arm/nwfpe/fpa11_cprt.c
    linux-user/arm/nwfpe/fpa11.h
    linux-user/flat.h
    linux-user/flatload.c
    linux-user/i386/target_syscall.h
    linux-user/ppc/target_syscall.h
    linux-user/sparc/target_syscall.h
    linux-user/syscall.c
    linux-user/syscall_defs.h
    linux-user/x86_64/target_syscall.h
    slirp/cksum.c
    slirp/if.c
    slirp/ip.h
    slirp/ip_icmp.c
    slirp/ip_icmp.h
    slirp/ip_input.c
    slirp/ip_output.c
    slirp/mbuf.c
    slirp/misc.c
    slirp/sbuf.c
    slirp/socket.c
    slirp/socket.h
    slirp/tcp_input.c
    slirp/tcpip.h
    slirp/tcp_output.c
    slirp/tcp_subr.c
    slirp/tcp_timer.c
    slirp/tftp.c
    slirp/udp.c
    slirp/udp.h
    target/cris/cpu.h
    target/cris/mmu.c
    target/cris/op_helper.c
    target/sh4/helper.c
    target/sh4/op_helper.c
    target/sh4/translate.c
    tcg/sparc/tcg-target.inc.c
    tests/tcg/cris/check_addo.c
    tests/tcg/cris/check_moveq.c
    tests/tcg/cris/check_swap.c
    tests/tcg/multiarch/test-mmap.c
    ui/vnc-enc-hextile-template.h
    ui/vnc-enc-zywrle.h
    util/envlist.c
    util/readline.c

The following have only TABs:

    bsd-user/i386/target_signal.h
    bsd-user/sparc64/target_signal.h
    bsd-user/sparc64/target_syscall.h
    bsd-user/sparc/target_signal.h
    bsd-user/sparc/target_syscall.h
    bsd-user/x86_64/target_signal.h
    crypto/desrfb.c
    hw/audio/intel-hda-defs.h
    hw/core/uboot_image.h
    hw/sh4/sh7750_regnames.c
    hw/sh4/sh7750_regs.h
    include/hw/cris/etraxfs_dma.h
    linux-user/alpha/termbits.h
    linux-user/arm/nwfpe/fpopcode.h
    linux-user/arm/nwfpe/fpsr.h
    linux-user/arm/syscall_nr.h
    linux-user/arm/target_signal.h
    linux-user/cris/target_signal.h
    linux-user/i386/target_signal.h
    linux-user/linux_loop.h
    linux-user/m68k/target_signal.h
    linux-user/microblaze/target_signal.h
    linux-user/mips64/target_signal.h
    linux-user/mips/target_signal.h
    linux-user/mips/target_syscall.h
    linux-user/mips/termbits.h
    linux-user/ppc/target_signal.h
    linux-user/sh4/target_signal.h
    linux-user/sh4/termbits.h
    linux-user/sparc64/target_syscall.h
    linux-user/sparc/target_signal.h
    linux-user/x86_64/target_signal.h
    linux-user/x86_64/termbits.h
    pc-bios/optionrom/optionrom.h
    slirp/mbuf.h
    slirp/misc.h
    slirp/sbuf.h
    slirp/tcp.h
    slirp/tcp_timer.h
    slirp/tcp_var.h
    target/i386/svm.h
    target/sparc/asi.h
    target/xtensa/core-dc232b/xtensa-modules.inc.c
    target/xtensa/core-dc233c/xtensa-modules.inc.c
    target/xtensa/core-de212/core-isa.h
    target/xtensa/core-de212/xtensa-modules.inc.c
    target/xtensa/core-fsf/xtensa-modules.inc.c
    target/xtensa/core-sample_controller/core-isa.h
    target/xtensa/core-sample_controller/xtensa-modules.inc.c
    target/xtensa/core-test_kc705_be/core-isa.h
    target/xtensa/core-test_kc705_be/xtensa-modules.inc.c
    tests/tcg/cris/check_abs.c
    tests/tcg/cris/check_addc.c
    tests/tcg/cris/check_addcm.c
    tests/tcg/cris/check_addoq.c
    tests/tcg/cris/check_bound.c
    tests/tcg/cris/check_ftag.c
    tests/tcg/cris/check_int64.c
    tests/tcg/cris/check_lz.c
    tests/tcg/cris/check_openpf5.c
    tests/tcg/cris/check_sigalrm.c
    tests/tcg/cris/crisutils.h
    tests/tcg/cris/sys.c
    tests/tcg/i386/test-i386-ssse3.c
    ui/vgafont.h

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181213223737.11793-3-pbonzini@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:56 +01:00
Kevin Wolf eaa2410f1e block: Require auto-read-only for existing fallbacks
Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
since 2.11, expecting users to provide an explicit read-only=on option.

Now that we have auto-read-only=on, enable these drivers to make use of
the option.

This is the only use of bdrv_set_read_only(), so we can make it a bit
more specific and turn it into a bdrv_apply_auto_read_only() that is
more convenient for drivers to use.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
Kevin Wolf 398e6ad014 block: Deprecate bdrv_set_read_only() and users
bdrv_set_read_only() is used by some block drivers to override the
read-only option given by the user. This is not how read-only images
generally work in QEMU: Instead of second guessing what the user really
meant (which currently includes making an image read-only even if the
user didn't only use the default, but explicitly said read-only=off), we
should error out if we can't provide what the user requested.

This adds deprecation warnings to all callers of bdrv_set_read_only() so
that the behaviour can be corrected after the usual deprecation period.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 13:35:59 +01:00
Jeff Cody e2b8247a32 block: do not set BDS read_only if copy_on_read enabled
A few block drivers will set the BDS read_only flag from their
.bdrv_open() function.  This means the bs->read_only flag could
be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ
flag check occurs prior to the call to bdrv->bdrv_open().

This adds an error return to bdrv_set_read_only(), and an error will be
return if we try to set the BDS to read_only while copy_on_read is
enabled.

This patch also changes the behavior of vvfat.  Before, vvfat could
override the drive 'readonly' flag with its own, internal 'rw' flag.

For instance, this -drive parameter would result in a writable image:

"-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on"

This is not correct.  Now, attempting to use the above -drive parameter
will result in an error (i.e., 'rw' is incompatible with 'readonly=on').

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Jeff Cody fe5241bfe3 block: add bdrv_set_read_only() helper function
We have a helper wrapper for checking for the BDS read_only flag,
add a helper wrapper to set the read_only flag as well.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Kevin Wolf 862f215fab block: Request child permissions in format drivers
This makes use of the .bdrv_child_perm() implementation for formats that
we just added. All format drivers expose the permissions they actually
need nows, so that they can be set accordingly and updated when parents
are attached or detached.

The only format not included here is raw, which was already converted
with the other filter drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf 4e4bf5c42c block: Attach bs->file only during .bdrv_open()
The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.

This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.

For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.

This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Kevin Wolf a03ef88f77 block: Convert bdrv_co_preadv/pwritev to BdrvChild
This is the final patch for converting the common I/O path to take
a BdrvChild parameter instead of BlockDriverState.

The completion of this conversion means that all users that perform I/O
on an image need to actually hold a reference (in the form of BdrvChild,
possible as part of a BlockBackend) to that image. This also protects
against inconsistent use of BlockBackend vs. BlockDriverState functions
because direct use of a BlockDriverState isn't possible any more and
blk->root is private for block-backends.c.

In addition, we can now distinguish different users in the I/O path,
and the future op blockers work is going to add assertions based on
permissions stored in BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf cf2ab8fc34 block: Convert bdrv_pread(v) to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Eric Blake 5411541270 block: Use bool as appropriate for BDS members
Using int for values that are only used as booleans is confusing.
While at it, rearrange a couple of members so that all the bools
are contiguous.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake a5b8dd2ce8 block: Move request_alignment into BlockLimit
It makes more sense to have ALL block size limit constraints
in the same struct.  Improve the documentation while at it.

Simplify a couple of conditionals, now that we have audited and
documented that request_alignment is always non-zero.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake a65064816d block: Set request_alignment during .bdrv_refresh_limits()
We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Add a .bdrv_refresh_limits() to all four of our legacy devices
that will always be sector-only (bochs, cloop, dmg, vvfat), in
spite of their recent conversion to expose a byte interface.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:25 +02:00
Paolo Bonzini 58369e22cf qemu-common: stop including qemu/bswap.h from qemu-common.h
Move it to the actual users.  There are still a few includes of
qemu/bswap.h in headers; removing them is left for future work.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:28 +02:00
Kevin Wolf 3b8fd33011 bochs: Implement .bdrv_co_preadv() interface
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-12 15:22:08 +02:00
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Peter Maydell 80c71a241a block: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-20 13:36:23 +01:00
Kevin Wolf 9a4f4c3156 block: Convert bs->file to BdrvChild
This patch removes the temporary duplication between bs->file and
bs->file_child by converting everything to BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16 15:34:29 +02:00
Markus Armbruster 02c4f26b15 block: Use g_new() & friends to avoid multiplying sizes
g_new(T, n) is safer than g_malloc(sizeof(*v) * n) for two reasons.
One, it catches multiplication overflowing size_t.  Two, it returns
T * rather than void *, which lets the compiler catch more type
errors.

Perhaps a conversion to g_malloc_n() would be neater in places, but
that's merely four years old, and we can't use such newfangled stuff.

This commit only touches allocations with size arguments of the form
sizeof(T), plus two that use 4 instead of sizeof(uint32_t).  We can
make the others safe by converting to g_malloc_n() when it becomes
available to us in a couple of years.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-20 11:51:28 +02:00
Kevin Wolf 7bf665ee35 bochs: Handle failure for potentially large allocations
Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the bochs block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-08-15 15:07:15 +02:00
Max Reitz e1b42f456f block/bochs: Fix error handling for seek_to_sector()
Currently, seek_to_sector() returns -1 both for errors and unallocated
sectors, resulting in silent errors. As 0 is an invalid offset of data
clusters (bitmap_offset is greater than 0 because s->data_offset is
greater than 0), just return 0 for unallocated sectors and -errno in
case of error. This should then be propagated by bochs_read(), the sole
user of seek_to_sector().

That function also has a case of "return -1 in case of error", which is
fixed by this patch as well.

bochs_read() is called by bochs_co_read() which passes the return value
through, therefore it is indeed correct for bochs_read() to return
-errno.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30 14:46:17 +02:00
Kevin Wolf 715c3f60ef bochs: Fix catalog size check
The old check was off by a factor of 512 and didn't consider cases where
we don't get an exact division. This could lead to an out-of-bounds
array access in seek_to_sector().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2014-04-11 13:59:49 +02:00
Kevin Wolf 28ec11bc88 bochs: Fix memory leak in bochs_open() error path
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2014-04-11 13:59:49 +02:00
Kevin Wolf a9ba36a45d bochs: Fix bitmap offset calculation
32 bit truncation could let us access the wrong offset in the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Kevin Wolf 8e53abbc20 bochs: Check extent_size header field (CVE-2014-0142)
This fixes two possible division by zero crashes: In bochs_open() and in
seek_to_sector().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Kevin Wolf e3737b820b bochs: Check catalog_size header field (CVE-2014-0143)
It should neither become negative nor allow unbounded memory
allocations. This fixes aborts in g_malloc() and an s->catalog_bitmap
buffer overflow on big endian hosts.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Kevin Wolf 246f65838d bochs: Use unsigned variables for offsets and sizes (CVE-2014-0147)
Gets us rid of integer overflows resulting in negative sizes which
aren't correctly checked.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Kevin Wolf 3dd8a6763b bochs: Unify header structs and make them QEMU_PACKED
This is an on-disk structure, so offsets must be accurate.

Before this patch, sizeof(bochs) != sizeof(header_v1), which makes the
memcpy() between both invalid. We're lucky enough that the destination
buffer happened to be the larger one, and the memcpy size to be taken
from the smaller one, so we didn't get a buffer overflow in practice.

This patch unifies the both structures, eliminating the need to do a
memcpy in the first place. The common fields are extracted to the top
level of the struct and the actually differing part gets a union of the
two versions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Paolo Bonzini 76abe4071d block: do not abuse EMEDIUMTYPE
Returning "Wrong medium type" for an image that does not have a valid
header is a bit weird.  Improve the error by mentioning what format
was trying to open it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:24 +01:00
Max Reitz 015a1036a7 bdrv: Use "Error" for opening images
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:47 +02:00
Kevin Wolf 1a86938f04 block: Add options QDict to .bdrv_open()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Kevin Wolf 5b7d7dfd19 bochs: Fix bdrv_open() error handling
Return -errno instead of -1 on errors. While touching the
code, fix a memory leak.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01 14:58:28 +01:00
Stefan Weil 15bac0d54f block: Use error code EMEDIUMTYPE for wrong format in some block drivers
This improves error reports for bochs, cow, qcow, qcow2, qed and vmdk
when a file with the wrong format is selected.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:35 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Paolo Bonzini 2914caa088 block: take lock around bdrv_read implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_read implementations to take the mutex.

Drivers that implement bdrv_read rather than bdrv_co_readv can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.

raw-win32 does not need the lock, because it cannot yield.
nbd also doesn't probably, but better be safe.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00