Track whether bfq_group is still online. We cannot rely on blkcg_gq->online because that gets cleared only after all policies are offlined and we need something that gets updated already under bfqd->lock when we are cleaning up our bfq_group to be able to guarantee that when we see online bfq_group, it will stay online while we are holding bfqd->lock lock.
CC: stable@vger.kernel.org Tested-by: "yukuai (C)" yukuai3@huawei.com Signed-off-by: Jan Kara jack@suse.cz --- block/bfq-cgroup.c | 3 ++- block/bfq-iosched.h | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 9352f3cc2377..879380c2bc7e 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -557,6 +557,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd) */ bfqg->bfqd = bfqd; bfqg->active_entities = 0; + bfqg->online = true; bfqg->rq_pos_tree = RB_ROOT; }
@@ -603,7 +604,6 @@ struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct bfq_entity *entity;
bfqg = bfq_lookup_bfqg(bfqd, blkcg); - if (unlikely(!bfqg)) return NULL;
@@ -979,6 +979,7 @@ static void bfq_pd_offline(struct blkg_policy_data *pd)
put_async_queues: bfq_put_async_queues(bfqd, bfqg); + bfqg->online = false;
spin_unlock_irqrestore(&bfqd->lock, flags); /* diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index a56763045d19..4664e2f3e828 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -928,6 +928,8 @@ struct bfq_group {
/* reference counter (see comments in bfq_bic_update_cgroup) */ int ref; + /* Is bfq_group still online? */ + bool online;
struct bfq_entity entity; struct bfq_sched_data sched_data;