bdrv_append() cares about isolation of the node that it modifies, but not about activity in some subtree below it. Instead of using the recursive bdrv_requests_pending(), directly check bs->in_flight, which considers only the node in question.
Signed-off-by: Kevin Wolf <kw...@redhat.com> Reviewed-by: Max Reitz <mre...@redhat.com> Acked-by: Fam Zheng <f...@redhat.com> --- block.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 9e538a5..5189c7c 100644 --- a/block.c +++ b/block.c @@ -2897,8 +2897,8 @@ static void change_parent_backing_link(BlockDriverState *from, */ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) { - assert(!bdrv_requests_pending(bs_top)); - assert(!bdrv_requests_pending(bs_new)); + assert(!atomic_read(&bs_top->in_flight)); + assert(!atomic_read(&bs_new->in_flight)); bdrv_ref(bs_top); -- 1.8.3.1