Fix -snapshot deleting images on disk change

Block device change command did not copy BDRV_O_SNAPSHOT flag. Thus
the new image did not have this flag and the file got deleted during
opening.

Fix by copying BDRV_O_SNAPSHOT flag.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 199630b62ec7cc5efd6f860ff545b449c7b5cdb8)

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/block.c b/block.c
index 49e6cbcd52..452ae94eea 100644
--- a/block.c
+++ b/block.c
@@ -1811,6 +1811,11 @@ int bdrv_can_snapshot(BlockDriverState *bs)
     return 1;
 }
 
+int bdrv_is_snapshot(BlockDriverState *bs)
+{
+    return !!(bs->open_flags & BDRV_O_SNAPSHOT);
+}
+
 BlockDriverState *bdrv_snapshots(void)
 {
     BlockDriverState *bs;