Moving bfqq to it's parent bfqg is pointless.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
block/bfq-cgroup.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 09ff0bb1042c..5e65b0407e85 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -645,6 +645,14 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
struct bfq_group *bfqg)
{
struct bfq_entity *entity = &bfqq->entity;
+ struct bfq_group *old_parent = bfq_group(bfqq);
+
+ /*
+ * No point to move bfqq to the same group, which can happen when
+ * root group is offlined
+ */
+ if (old_parent == bfqg)
+ return;
/*
* Get extra reference to prevent bfqq from being freed in
@@ -666,7 +674,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
bfq_deactivate_bfqq(bfqd, bfqq, false, false);
else if (entity->on_st_or_in_serv)
bfq_put_idle_entity(bfq_entity_service_tree(entity), entity);
- bfqg_and_blkg_put(bfqq_group(bfqq));
+ bfqg_and_blkg_put(old_parent);
if (entity->parent &&
entity->parent->last_bfqq_created == bfqq)
--
2.31.1
