diff options
Diffstat (limited to 'block/blk-throttle.c')
| -rw-r--r-- | block/blk-throttle.c | 58 |
1 files changed, 4 insertions, 54 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 9c8a12477e13..153ba509446b 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -54,7 +54,6 @@ struct throtl_grp { */ unsigned long disptime; - atomic_t ref; unsigned int flags; /* Two lists for READ and WRITE */ @@ -80,8 +79,6 @@ struct throtl_grp { /* Some throttle limits got updated for the group */ int limits_changed; - - struct rcu_head rcu_head; }; struct throtl_data @@ -151,45 +148,6 @@ static inline unsigned int total_nr_queued(struct throtl_data *td) return td->nr_queued[0] + td->nr_queued[1]; } -static inline struct throtl_grp *throtl_ref_get_tg(struct throtl_grp *tg) -{ - atomic_inc(&tg->ref); - return tg; -} - -static void throtl_free_tg(struct rcu_head *head) -{ - struct throtl_grp *tg = container_of(head, struct throtl_grp, rcu_head); - struct blkio_group *blkg = tg_to_blkg(tg); - - free_percpu(blkg->stats_cpu); - kfree(blkg->pd); - kfree(blkg); -} - -static void throtl_put_tg(struct throtl_grp *tg) -{ - struct blkio_group *blkg = tg_to_blkg(tg); - - BUG_ON(atomic_read(&tg->ref) <= 0); - if (!atomic_dec_and_test(&tg->ref)) - return; - - /* release the extra blkcg reference this blkg has been holding */ - css_put(&blkg->blkcg->css); - - /* - * A group is freed in rcu manner. But having an rcu lock does not - * mean that one can access all the fields of blkg and assume these - * are valid. For example, don't try to follow throtl_data and - * request queue links. - * - * Having a reference to blkg under an rcu allows acess to only - * values local to groups like group stats and group rate limits - */ - call_rcu(&tg->rcu_head, throtl_free_tg); -} - static void throtl_init_blkio_group(struct blkio_group *blkg) { struct throtl_grp *tg = blkg_to_tg(blkg); @@ -204,14 +162,6 @@ static void throtl_init_blkio_group(struct blkio_group *blkg) tg->bps[WRITE] = -1; tg->iops[READ] = -1; tg->iops[WRITE] = -1; - - /* - * Take the initial reference that will be released on destroy - * This can be thought of a joint reference by cgroup and - * request queue which will be dropped by either request queue - * exit or cgroup deletion path depending on who is exiting first. - */ - atomic_set(&tg->ref, 1); } static void throtl_link_blkio_group(struct request_queue *q, @@ -648,7 +598,7 @@ static void throtl_add_bio_tg(struct throtl_data *td, struct throtl_grp *tg, bio_list_add(&tg->bio_lists[rw], bio); /* Take a bio reference on tg */ - throtl_ref_get_tg(tg); + blkg_get(tg_to_blkg(tg)); tg->nr_queued[rw]++; td->nr_queued[rw]++; throtl_enqueue_tg(td, tg); @@ -681,8 +631,8 @@ static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg, bio = bio_list_pop(&tg->bio_lists[rw]); tg->nr_queued[rw]--; - /* Drop bio reference on tg */ - throtl_put_tg(tg); + /* Drop bio reference on blkg */ + blkg_put(tg_to_blkg(tg)); BUG_ON(td->nr_queued[rw] <= 0); td->nr_queued[rw]--; @@ -880,7 +830,7 @@ throtl_destroy_tg(struct throtl_data *td, struct throtl_grp *tg) * Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. */ - throtl_put_tg(tg); + blkg_put(tg_to_blkg(tg)); td->nr_undestroyed_grps--; } |
