bfq: Track whether bfq_group is still online (28a8060a) · Commits · e / devices / android_kernel_fairphone_FP5

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

+2 −1

Original line number	Diff line number	Diff line
		@@ -536,6 +536,7 @@ 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;
		}

		@@ -582,7 +583,6 @@ 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;

		@@ -944,6 +944,7 @@ 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);
		/*

block/bfq-iosched.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -896,6 +896,8 @@ 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;