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>
(cherry picked from commit 4c2e5f8f46)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Test 039 had $TEST_IMG with duplicate double quotes - remove duplicate.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
A lot of image filename and paths are used unquoted. Quote these to
make sure that directories / filenames with spaces are not problematic.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch adds the support for reporting the image end offset (in
bytes). This is particularly useful after a conversion (or a rebase)
where the destination is a block device in order to find the first
unused byte at the end of the image.
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When the qemu-io --nocache option is used the 039 test case cannot abort
QEMU at a point where the image is dirty. Skip the test case.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This tests establishes the basic post-conditions of the qcow2 lazy
refcounts features:
1. If the image was closed normally, it is marked clean.
2. If an allocating write was performed and the image was not closed
normally, then it is marked dirty.
a. Written data can be read back successfully.
b. The image file can be repaired and will be marked clean again.
c. The image file is automatically repaired when opened read/write.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
