Yu Kuai Signed-off-by: Jens Axboe Signed-off-by: Robert Garcia --- block/blk-cgroup.c | 6 ------ block/blk-cgroup.h | 6 ++++++ block/blk-throttle.c | 6 +----- block/blk-throttle.h | 18 +++++++++++------- 4 files changed, 18 insertions(+), 18 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 5a5525d10a5e..3f7cb9d891aa 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -110,12 +110,6 @@ static struct cgroup_subsys_state *blkcg_css(void) return task_css(current, io_cgrp_id); } -static bool blkcg_policy_enabled(struct request_queue *q, - const struct blkcg_policy *pol) -{ - return pol && test_bit(pol->plid, q->blkcg_pols); -} - static void blkg_free_workfn(struct work_struct *work) { struct blkcg_gq *blkg = container_of(work, struct blkcg_gq, diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index b9e3265c1eb3..112bf11d0fad 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -455,6 +455,12 @@ static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) bio_issue_as_root_blkg(rq->bio) == bio_issue_as_root_blkg(bio); } +static inline bool blkcg_policy_enabled(struct request_queue *q, + const struct blkcg_policy *pol) +{ + return pol && test_bit(pol->plid, q->blkcg_pols); +} + void blk_cgroup_bio_start(struct bio *bio); void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta); #else /* CONFIG_BLK_CGROUP */ diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 4aa66c07d2e8..bdf363868ac0 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1209,17 +1209,13 @@ static int blk_throtl_init(struct gendisk *disk) INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); throtl_service_queue_init(&td->service_queue); - /* - * Freeze queue before activating policy, to synchronize with IO path, - * which is protected by 'q_usage_counter'. - */ blk_mq_freeze_queue(disk->queue); blk_mq_quiesce_queue(disk->queue); q->td = td; td->queue = q; - /* activate policy */ + /* activate policy, blk_throtl_activated() will return true */ ret = blkcg_activate_policy(disk, &blkcg_policy_throtl); if (ret) { q->td = NULL; diff --git a/block/blk-throttle.h b/block/blk-throttle.h index 1a36d1278eea..e1b5343cd43f 100644 --- a/block/blk-throttle.h +++ b/block/blk-throttle.h @@ -154,7 +154,13 @@ void blk_throtl_cancel_bios(struct gendisk *disk); static inline bool blk_throtl_activated(struct request_queue *q) { - return q->td != NULL; + /* + * q->td guarantees that the blk-throttle module is already loaded, + * and the plid of blk-throttle is assigned. + * blkcg_policy_enabled() guarantees that the policy is activated + * in the request_queue. + */ + return q->td != NULL && blkcg_policy_enabled(q, &blkcg_policy_throtl); } static inline bool blk_should_throtl(struct bio *bio) @@ -162,11 +168,6 @@ static inline bool blk_should_throtl(struct bio *bio) struct throtl_grp *tg; int rw = bio_data_dir(bio); - /* - * This is called under bio_queue_enter(), and it's synchronized with - * the activation of blk-throtl, which is protected by - * blk_mq_freeze_queue(). - */ if (!blk_throtl_activated(bio->bi_bdev->bd_queue)) return false; @@ -192,7 +193,10 @@ static inline bool blk_should_throtl(struct bio *bio) static inline bool blk_throtl_bio(struct bio *bio) { - + /* + * block throttling takes effect if the policy is activated + * in the bio's request_queue. + */ if (!blk_should_throtl(bio)) return false; -- 2.34.1[PATCH 6.12.y] blk-throttle: fix access race during throttle policy activationRobert Garcia undefinedstable@vger.kernel.org, Han Guangjiang undefined undefined undefined undefined undefined undefined undefined undefined undefined undefinedƒ