From: Jan Kara jack@suse.cz
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@vger.kernel.org Tested-by: "yukuai (C)" yukuai3@huawei.com Signed-off-by: Jan Kara jack@suse.cz Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20220401102752.8599-7-jack@suse.cz Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -553,6 +553,7 @@ static void bfq_pd_init(struct blkg_poli */ bfqg->bfqd = bfqd; bfqg->active_entities = 0; + bfqg->online = true; bfqg->rq_pos_tree = RB_ROOT; }
@@ -599,7 +600,6 @@ struct bfq_group *bfq_find_set_group(str struct bfq_entity *entity;
bfqg = bfq_lookup_bfqg(bfqd, blkcg); - if (unlikely(!bfqg)) return NULL;
@@ -961,6 +961,7 @@ 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 @@ -901,6 +901,8 @@ 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;