Setting the QCOW_OFLAG_ZERO bit of the L2 entry is forbidden if an
image has subclusters. Instead, the individual 'all zeroes' bits must
be used.
Signed-off-by: Alberto Garcia <be...@igalia.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
block/qcow2-refcount.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 770c5dbc83..696e4dad07 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1686,8 +1686,13 @@ static int check_refcounts_l2(BlockDriverState *bs,
BdrvCheckResult *res,
int ign = active ? QCOW2_OL_ACTIVE_L2 :
QCOW2_OL_INACTIVE_L2;
- l2_entry = QCOW_OFLAG_ZERO;
- set_l2_entry(s, l2_table, i, l2_entry);
+ if (has_subclusters(s)) {
+ set_l2_entry(s, l2_table, i, 0);
+ set_l2_bitmap(s, l2_table, i,
+ QCOW_L2_BITMAP_ALL_ZEROES);
+ } else {
+ set_l2_entry(s, l2_table, i, QCOW_OFLAG_ZERO);
+ }
ret = qcow2_pre_write_overlap_check(bs, ign,
l2e_offset, l2_entry_size(s), false);
if (ret < 0) {
--
2.20.1
