l2meta_cow_start() and l2meta_cow_end() are not necessarily cluster-aligned if the image has subclusters, so update the calculation of old_start and old_end to guarantee that no two requests try to write on the same cluster.
Signed-off-by: Alberto Garcia <be...@igalia.com> --- block/qcow2-cluster.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 62f2a9fcc0..fb6cf8df17 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1262,8 +1262,8 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset, uint64_t start = guest_offset; uint64_t end = start + bytes; - uint64_t old_start = l2meta_cow_start(old_alloc); - uint64_t old_end = l2meta_cow_end(old_alloc); + uint64_t old_start = start_of_cluster(s, l2meta_cow_start(old_alloc)); + uint64_t old_end = ROUND_UP(l2meta_cow_end(old_alloc), s->cluster_size); if (end <= old_start || start >= old_end) { /* No intersection */ -- 2.20.1