From: "Denis V. Lunev" <d...@openvz.org>
We should check for (res & BDRV_BLOCK_ZERO) only. The situation when we
will have !(res & BDRV_BLOCK_DATA) and will not have BDRV_BLOCK_ZERO is
not possible for images with bdi.unallocated_blocks_are_zero == true.
For those images where it's false, however, it can happen and we must
not consider the data zeroed then or we would corrupt the image.
Signed-off-by: Denis V. Lunev <d...@openvz.org>
CC: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 62febfc..a6012dc 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2412,7 +2412,7 @@ static bool is_zero_cluster(BlockDriverState *bs, int64_t
start)
BlockDriverState *file;
int64_t res = bdrv_get_block_status_above(bs, NULL, start,
s->cluster_sectors, &nr, &file);
- return res >= 0 && ((res & BDRV_BLOCK_ZERO) || !(res & BDRV_BLOCK_DATA));
+ return res >= 0 && (res & BDRV_BLOCK_ZERO);
}
static bool is_zero_cluster_top_locked(BlockDriverState *bs, int64_t start)
--
1.8.3.1
