Searched hist:"4 c2e5f8f" (Results 1 – 3 of 3) sorted by relevance
| /openbmc/qemu/tests/qemu-iotests/ |
| H A D | 039.out | 4c2e5f8f Thu Apr 03 06:47:50 CDT 2014 Kevin Wolf <kwolf@redhat.com> qcow2: Flush metadata during read-only reopen
If lazy refcounts are enabled for a backing file, committing to this
backing file may leave it in a dirty state even if the commit succeeds.
The reason is that the bdrv_flush() call in bdrv_commit() doesn't flush
refcount updates with lazy refcounts enabled, and qcow2_reopen_prepare()
doesn't take care to flush metadata.
In order to fix this, this patch also fixes qcow2_mark_clean(), which
contains another ineffective bdrv_flush() call beause lazy refcounts are
disabled only afterwards. All existing callers of qcow2_mark_clean()
either don't modify refcounts or already flush manually, so that this
fixes only a latent, but not yet actually triggerable bug.
Another instance of the same problem is live snapshots. Again, a real
corruption is prevented by an explicit flush for non-read-only images in
external_snapshot_prepare(), but images using lazy refcounts stay dirty.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
|
| H A D | 039 | 4c2e5f8f Thu Apr 03 06:47:50 CDT 2014 Kevin Wolf <kwolf@redhat.com> qcow2: Flush metadata during read-only reopen
If lazy refcounts are enabled for a backing file, committing to this
backing file may leave it in a dirty state even if the commit succeeds.
The reason is that the bdrv_flush() call in bdrv_commit() doesn't flush
refcount updates with lazy refcounts enabled, and qcow2_reopen_prepare()
doesn't take care to flush metadata.
In order to fix this, this patch also fixes qcow2_mark_clean(), which
contains another ineffective bdrv_flush() call beause lazy refcounts are
disabled only afterwards. All existing callers of qcow2_mark_clean()
either don't modify refcounts or already flush manually, so that this
fixes only a latent, but not yet actually triggerable bug.
Another instance of the same problem is live snapshots. Again, a real
corruption is prevented by an explicit flush for non-read-only images in
external_snapshot_prepare(), but images using lazy refcounts stay dirty.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
|
| /openbmc/qemu/block/ |
| H A D | qcow2.c | 4c2e5f8f Thu Apr 03 06:47:50 CDT 2014 Kevin Wolf <kwolf@redhat.com> qcow2: Flush metadata during read-only reopen
If lazy refcounts are enabled for a backing file, committing to this
backing file may leave it in a dirty state even if the commit succeeds.
The reason is that the bdrv_flush() call in bdrv_commit() doesn't flush
refcount updates with lazy refcounts enabled, and qcow2_reopen_prepare()
doesn't take care to flush metadata.
In order to fix this, this patch also fixes qcow2_mark_clean(), which
contains another ineffective bdrv_flush() call beause lazy refcounts are
disabled only afterwards. All existing callers of qcow2_mark_clean()
either don't modify refcounts or already flush manually, so that this
fixes only a latent, but not yet actually triggerable bug.
Another instance of the same problem is live snapshots. Again, a real
corruption is prevented by an explicit flush for non-read-only images in
external_snapshot_prepare(), but images using lazy refcounts stay dirty.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
|