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  1. 01 7月, 2014 1 次提交
    • C
      qemu-img create: add 'nocow' option · 4ab15590
      由 Chunyan Liu 提交于 
      Add 'nocow' option so that users could have a chance to set NOCOW flag to
newly created files. It's useful on btrfs file system to enhance performance.

Btrfs has low performance when hosting VM images, even more when the guest
in those VM are also using btrfs as file system. One way to mitigate this bad
performance is to turn off COW attributes on VM files. Generally, there are
two ways to turn off NOCOW on btrfs: a) by mounting fs with nodatacow, then
all newly created files will be NOCOW. b) per file. Add the NOCOW file
attribute. It could only be done to empty or new files.

This patch tries the second way, according to the option, it could add NOCOW
per file.

For most block drivers, since the create file step is in raw-posix.c, so we
can do setting NOCOW flag ioctl in raw-posix.c only.

But there are some exceptions, like block/vpc.c and block/vdi.c, they are
creating file by calling qemu_open directly. For them, do the same setting
NOCOW flag ioctl work in them separately.

[Fixed up 082.out due to the new 'nocow' creation option
--Stefan]
Signed-off-by: NChunyan Liu <cyliu@suse.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      4ab15590
  3. 26 6月, 2014 1 次提交
  5. 16 6月, 2014 3 次提交
  7. 04 6月, 2014 1 次提交
    • S
      qed: use BlockDriverState's AioContext · a8c868c3
      由 Stefan Hajnoczi 提交于 
      Drop the assumption that we're using the main AioContext.  Convert
qemu_bh_new() to aio_bh_new() and qemu_aio_wait() to aio_poll() so we're
using the BlockDriverState's AioContext.

Implement .bdrv_detach/attach_aio_context() interfaces to move the
QED_F_NEED_CHECK timer from the old AioContext to the new one.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      a8c868c3
  9. 22 4月, 2014 1 次提交
  11. 19 3月, 2014 1 次提交
  13. 13 3月, 2014 1 次提交
    • K
      block: Update image size in bdrv_invalidate_cache() · 3456a8d1
      由 Kevin Wolf 提交于 
      After migration has completed, we call bdrv_invalidate_cache() so that
drivers which cache some data drop their stale copy of the data and
reread it from the image file to get a new version of data that the
source modified while the migration was running.

Reloading metadata from the image file is useless, though, if the size
of the image file stays stale (this is a value that is cached for all
image formats in block.c). Reads from (meta)data after the old EOF
return only zeroes, causing image corruption.

We need to update bs->total_sectors in all layers that could potentially
have changed their size (i.e. backing files are not a concern - if they
are changed, we're in bigger trouble)
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      3456a8d1
  15. 22 2月, 2014 3 次提交
  17. 01 2月, 2014 1 次提交
  19. 25 1月, 2014 1 次提交
  21. 22 1月, 2014 1 次提交
  23. 03 12月, 2013 2 次提交
  25. 28 11月, 2013 1 次提交
  27. 12 9月, 2013 4 次提交
  29. 06 9月, 2013 3 次提交
  31. 23 8月, 2013 1 次提交
  33. 28 6月, 2013 1 次提交
    • P
      block: change default of .has_zero_init to 0 · 3ac21627
      由 Peter Lieven 提交于 
      .has_zero_init defaults to 1 for all formats and protocols.

this is a dangerous default since this means that all
new added drivers need to manually overwrite it to 0 if
they do not ensure that a device is zero initialized
after bdrv_create().

if a driver needs to explicitly set this value to
1 its easier to verify the correctness in the review process.

during review of the existing drivers it turned out
that ssh and gluster had a wrong default of 1.
both protocols support host_devices as backend
which are not by default zero initialized. this
wrong assumption will lead to possible corruption
if qemu-img convert is used to write to such a backend.

vpc and vmdk also defaulted to 1 altough they support
fixed respectively flat extends. this has to be addresses
in separate patches. both formats as well as the mentioned
ssh and gluster are turned to the default of 0 with this
patch for safety.

a similar problem with the wrong default existed for
iscsi most likely because the driver developer did
oversee the default value of 1.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      3ac21627
  35. 23 3月, 2013 1 次提交
  37. 15 3月, 2013 1 次提交
  39. 26 1月, 2013 1 次提交
  41. 19 12月, 2012 3 次提交
  43. 15 11月, 2012 1 次提交
  45. 24 9月, 2012 1 次提交
  47. 29 8月, 2012 1 次提交
  49. 10 8月, 2012 2 次提交
  51. 09 7月, 2012 1 次提交
  53. 15 6月, 2012 1 次提交
    • K
      qemu-img check -r for repairing images · 4534ff54
      由 Kevin Wolf 提交于 
      The QED block driver already provides the functionality to not only
detect inconsistencies in images, but also fix them. However, this
functionality cannot be manually invoked with qemu-img, but the
check happens only automatically during bdrv_open().

This adds a -r switch to qemu-img check that allows manual invocation
of an image repair.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      4534ff54