From: Max Reitz <mre...@redhat.com>
Using s->snapshots_size instead of snapshots_size for the metadata
overlap check in qcow2_write_snapshots leads to the detection of an
overlap with the main qcow2 image header when deleting the last
snapshot, since s->snapshots_size has not yet been updated and is
therefore non-zero. However, the offset returned by qcow2_alloc_clusters
will be zero since snapshots_size is zero. Therefore, an overlap is
detected albeit no such will occur.
This patch fixes this by replacing s->snapshots_size by snapshots_size
when calling qcow2_pre_write_overlap_check.
Signed-off-by: Max Reitz <mre...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
block/qcow2-snapshot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 7d14420..5e8a779 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -192,7 +192,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
/* The snapshot list position has not yet been updated, so these clusters
* must indeed be completely free */
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, offset,
- s->snapshots_size);
+ snapshots_size);
if (ret < 0) {
return ret;
}
--
1.8.3.1
