The qcow2_make_empty() function is reached during 'qemu-img commit',
in order to clear out ALL clusters of an image. However, if the
image cannot use the fast code path (true if the image is format
0.10, or if the image contains a snapshot), the cluster size is
larger than 512, and the image is larger than 2G in size, then our
choice of sector_step causes problems. Since it is not cluster
aligned, but qcow2_discard_clusters() silently ignores an unaligned
head or tail, we are leaving clusters allocated.
Enhance the testsuite to expose the flaw, and patch the problem by
ensuring our step size is aligned.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The previous commit removed the last usage of ${tmp} inside the tests
themselves; the only remaining users are sourced by check. So we can now
drop this variable from the tests.
Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Bo Tu <tubo@linux.vnet.ibm.com>
Message-id: 1460472980-26319-4-git-send-email-silbe@linux.vnet.ibm.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add a test for qemu-img commit on backing chains with more than two
images. This test also checks whether the top image is emptied (unless
this is prevented by specifying either -d or -b) and does therefore not
work for qed and vmdk which requires it to be separate from 020.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1414159063-25977-14-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
