tree 392958b989076df7e09dee397a50b4d327ce9ebf
parent 10f08a0a3435afea441db8d0981dbad49042c7cf
author Kevin Wolf <kwolf@redhat.com> 1399371102 +0200
committer Stefan Hajnoczi <stefanha@redhat.com> 1399661851 +0200

block: Fix open flags with BDRV_O_SNAPSHOT

The immediately visible effect of this patch is that it fixes committing
a temporary snapshot to its backing file. Previously, it would fail with
a "permission denied" error because bdrv_inherited_flags() forced the
backing file to be read-only, ignoring the r/w reopen of bdrv_commit().

The bigger problem this revealed is that the original open flags must
actually only be applied to the temporary snapshot, and the original
image file must be treated as a backing file of the temporary snapshot
and get the right flags for that.

Reported-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>