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  1. 04 6月, 2019 5 次提交
    • K
      block: Add BlockBackend.ctx · d861ab3a
      由 Kevin Wolf 提交于 
      This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).

The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      d861ab3a
    • K
      block: Add Error to blk_set_aio_context() · 97896a48
      由 Kevin Wolf 提交于 
      Add an Error parameter to blk_set_aio_context() and use
bdrv_child_try_set_aio_context() internally to check whether all
involved nodes can actually support the AioContext switch.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      97896a48
    • J
      block/linux-aio: Drop unused BlockAIOCB submission method · 2b02fd81
      由 Julia Suvorova 提交于 
      Callback-based laio_submit() and laio_cancel() were left after
rewriting Linux AIO backend to coroutines in hope that they would be
used in other code that could bypass coroutines. They can be safely
removed because they have not been used since that time.
Signed-off-by: NJulia Suvorova <jusual@mail.ru>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      2b02fd81
    • M
      block/io: Delay decrementing the quiesce_counter · 5cb2737e
      由 Max Reitz 提交于 
      When ending a drained section, bdrv_do_drained_end() currently first
decrements the quiesce_counter, and only then actually ends the drain.

The bdrv_drain_invoke(bs, false) call may cause graph changes.  Say the
graph change involves replacing an existing BB's ("blk") BDS
(blk_bs(blk)) by @bs.  Let us introducing the following values:
- bs_oqc = old_quiesce_counter
  (so bs->quiesce_counter == bs_oqc - 1)
- obs_qc = blk_bs(blk)->quiesce_counter (before bdrv_drain_invoke())

Let us assume there is no blk_pread_unthrottled() involved, so
blk->quiesce_counter == obs_qc (before bdrv_drain_invoke()).

Now replacing blk_bs(blk) by @bs will reduce blk->quiesce_counter by
obs_qc (making it 0) and increase it by bs_oqc-1 (making it bs_oqc-1).

bdrv_drain_invoke() returns and we invoke bdrv_parent_drained_end().
This will decrement blk->quiesce_counter by one, so it would be -1 --
were there not an assertion against that in blk_root_drained_end().

We therefore have to keep the quiesce_counter up at least until
bdrv_drain_invoke() returns, so that bdrv_parent_drained_end() does the
right thing for the parents @bs got during bdrv_drain_invoke().

But let us delay it even further, namely until bdrv_parent_drained_end()
returns, because then it mirrors bdrv_do_drained_begin(): There, we
first increment the quiesce_counter, then begin draining the parents,
and then call bdrv_drain_invoke().  It makes sense to let
bdrv_do_drained_end() unravel this exactly in reverse.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      5cb2737e
    • V
      block: avoid recursive block_status call if possible · 69f47505
      由 Vladimir Sementsov-Ogievskiy 提交于 
      drv_co_block_status digs bs->file for additional, more accurate search
for hole inside region, reported as DATA by bs since 5daa74a6.

This accuracy is not free: assume we have qcow2 disk. Actually, qcow2
knows, where are holes and where is data. But every block_status
request calls lseek additionally. Assume a big disk, full of
data, in any iterative copying block job (or img convert) we'll call
lseek(HOLE) on every iteration, and each of these lseeks will have to
iterate through all metadata up to the end of file. It's obviously
ineffective behavior. And for many scenarios we don't need this lseek
at all.

However, lseek is needed when we have metadata-preallocated image.

So, let's detect metadata-preallocation case and don't dig qcow2's
protocol file in other cases.

The idea is to compare allocation size in POV of filesystem with
allocations size in POV of Qcow2 (by refcounts). If allocation in fs is
significantly lower, consider it as metadata-preallocation case.

102 iotest changed, as our detector can't detect shrinked file as
metadata-preallocation, which don't seem to be wrong, as with metadata
preallocation we always have valid file length.

Two other iotests have a slight change in their QMP output sequence:
Active 'block-commit' returns earlier because the job coroutine yields
earlier on a blocking operation. This operation is loading the refcount
blocks in qcow2_detect_metadata_preallocation().
Suggested-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      69f47505
  3. 29 5月, 2019 17 次提交
  5. 20 5月, 2019 7 次提交
    • M
      block/file-posix: Unaligned O_DIRECT block-status · 9c3db310
      由 Max Reitz 提交于 
      Currently, qemu crashes whenever someone queries the block status of an
unaligned image tail of an O_DIRECT image:
$ echo > foo
$ qemu-img map --image-opts driver=file,filename=foo,cache.direct=on
Offset          Length          Mapped to       File
qemu-img: block/io.c:2093: bdrv_co_block_status: Assertion `*pnum &&
QEMU_IS_ALIGNED(*pnum, align) && align > offset - aligned_offset'
failed.

This is because bdrv_co_block_status() checks that the result returned
by the driver's implementation is aligned to the request_alignment, but
file-posix can fail to do so, which is actually mentioned in a comment
there: "[...] possibly including a partial sector at EOF".

Fix this by rounding up those partial sectors.

There are two possible alternative fixes:
(1) We could refuse to open unaligned image files with O_DIRECT
    altogether.  That sounds reasonable until you realize that qcow2
    does necessarily not fill up its metadata clusters, and that nobody
    runs qemu-img create with O_DIRECT.  Therefore, unpreallocated qcow2
    files usually have an unaligned image tail.

(2) bdrv_co_block_status() could ignore unaligned tails.  It actually
    throws away everything past the EOF already, so that sounds
    reasonable.
    Unfortunately, the block layer knows file lengths only with a
    granularity of BDRV_SECTOR_SIZE, so bdrv_co_block_status() usually
    would have to guess whether its file length information is inexact
    or whether the driver is broken.

Fixing what raw_co_block_status() returns is the safest thing to do.

There seems to be no other block driver that sets request_alignment and
does not make sure that it always returns aligned values.

Cc: qemu-stable@nongnu.org
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      9c3db310
    • K
      blockjob: Propagate AioContext change to all job nodes · 9ff7f0df
      由 Kevin Wolf 提交于 
      Block jobs require that all of the nodes the job is using are in the
same AioContext. Therefore all BdrvChild objects of the job propagate
.(can_)set_aio_context to all other job nodes, so that the switch is
checked and performed consistently even if both nodes are in different
subtrees.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      9ff7f0df
    • K
      block: Add blk_set_allow_aio_context_change() · 980b0f94
      由 Kevin Wolf 提交于 
      Some users (like block jobs) can tolerate an AioContext change for their
BlockBackend. Add a function that tells the BlockBackend that it can
allow changes.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      980b0f94
    • K
      block: Implement .(can_)set_aio_ctx for BlockBackend · 38475269
      由 Kevin Wolf 提交于 
      bdrv_try_set_aio_context() currently fails if a BlockBackend is attached
to a node because it doesn't implement the BdrvChildRole callbacks for
AioContext management.

We can allow changing the AioContext of monitor-owned BlockBackends as
long as no device is attached to them.

When setting the AioContext of the root node of a BlockBackend, we now
need to pass blk->root as an ignored child because we don't want the
root node to recursively call back into BlockBackend and execute
blk_do_set_aio_context() a second time.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      38475269
    • A
      block: Use BDRV_REQUEST_MAX_BYTES instead of BDRV_REQUEST_MAX_SECTORS · 41ae31e3
      由 Alberto Garcia 提交于 
      There are a few places in which we turn a number of bytes into sectors
in order to compare the result against BDRV_REQUEST_MAX_SECTORS
instead of using BDRV_REQUEST_MAX_BYTES directly.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      41ae31e3
    • A
      qcow2: Define and use QCOW2_COMPRESSED_SECTOR_SIZE · b6c24694
      由 Alberto Garcia 提交于 
      When an L2 table entry points to a compressed cluster the space used
by the data is specified in 512-byte sectors. This size is independent
from BDRV_SECTOR_SIZE and is specific to the qcow2 file format.

The QCOW2_COMPRESSED_SECTOR_SIZE constant defined in this patch makes
this explicit.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      b6c24694
    • M
      block/file-posix: Truncate in xfs_write_zeroes() · 50ba5b2d
      由 Max Reitz 提交于 
      XFS_IOC_ZERO_RANGE does not increase the file length:
$ touch foo
$ xfs_io -c 'zero 0 65536' foo
$ stat -c "size=%s, blocks=%b" foo
size=0, blocks=128

We do want writes beyond the EOF to automatically increase the file
length, however.  This is evidenced by the fact that iotest 061 is
broken on XFS since qcow2's check implementation checks for blocks
beyond the EOF.
Reported-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      50ba5b2d
  7. 13 5月, 2019 1 次提交
  9. 10 5月, 2019 6 次提交
  11. 07 5月, 2019 4 次提交