From: Jan Kara <jack@xxxxxxx> commit 09f871868080c33992cd6a9b72a5ca49582578fa upstream. 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@xxxxxxxxxxxxxxx Tested-by: "yukuai (C)" <yukuai3@xxxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/r/20220401102752.8599-7-jack@xxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/bfq-cgroup.c | 3 ++- block/bfq-iosched.h | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -555,6 +555,7 @@ static void bfq_pd_init(struct blkg_poli */ bfqg->bfqd = bfqd; bfqg->active_entities = 0; + bfqg->online = true; bfqg->rq_pos_tree = RB_ROOT; } @@ -601,7 +602,6 @@ struct bfq_group *bfq_find_set_group(str struct bfq_entity *entity; bfqg = bfq_lookup_bfqg(bfqd, blkcg); - if (unlikely(!bfqg)) return NULL; @@ -969,6 +969,7 @@ static void bfq_pd_offline(struct blkg_p put_async_queues: bfq_put_async_queues(bfqd, bfqg); + bfqg->online = false; spin_unlock_irqrestore(&bfqd->lock, flags); /* --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -926,6 +926,8 @@ 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;
