Commit 3c96cb32 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

blkcg: drop stuff unused after per-queue policy activation update 



* All_q_list is unused.  Drop all_q_{mutex|list}.

* @for_root of blkg_lookup_create() is always %false when called from
  outside blk-cgroup.c proper.  Factor out __blkg_lookup_create() so
  that it doesn't check whether @q is bypassing and use the
  underscored version for the @for_root callsite.

* blkg_destroy_all() is used only from blkcg proper and @destroy_root
  is always %true.  Make it static and drop @destroy_root.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a2b1693b

block/blk-cgroup.c

+20 −41
Original line number Diff line number Diff line
@@ -25,8 +25,6 @@ 
#define MAX_KEY_LEN 100



static DEFINE_MUTEX(blkcg_pol_mutex);

static DEFINE_MUTEX(all_q_mutex);

static LIST_HEAD(all_q_list);



struct blkio_cgroup blkio_root_cgroup = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT };

EXPORT_SYMBOL_GPL(blkio_root_cgroup);
@@ -179,9 +177,8 @@ struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg, 
}

EXPORT_SYMBOL_GPL(blkg_lookup);



struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,

				       struct request_queue *q,

				       bool for_root)

static struct blkio_group *__blkg_lookup_create(struct blkio_cgroup *blkcg,

						struct request_queue *q)

	__releases(q->queue_lock) __acquires(q->queue_lock)

{

	struct blkio_group *blkg;
@@ -189,13 +186,6 @@ struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, 
	WARN_ON_ONCE(!rcu_read_lock_held());

	lockdep_assert_held(q->queue_lock);



	/*

	 * This could be the first entry point of blkcg implementation and

	 * we shouldn't allow anything to go through for a bypassing queue.

	 */

	if (unlikely(blk_queue_bypass(q)) && !for_root)

		return ERR_PTR(blk_queue_dead(q) ? -EINVAL : -EBUSY);



	blkg = __blkg_lookup(blkcg, q);

	if (blkg)

		return blkg;
@@ -223,6 +213,18 @@ struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, 
out:

	return blkg;

}



struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,

				       struct request_queue *q)

{

	/*

	 * This could be the first entry point of blkcg implementation and

	 * we shouldn't allow anything to go through for a bypassing queue.

	 */

	if (unlikely(blk_queue_bypass(q)))

		return ERR_PTR(blk_queue_dead(q) ? -EINVAL : -EBUSY);

	return __blkg_lookup_create(blkcg, q);

}

EXPORT_SYMBOL_GPL(blkg_lookup_create);



static void blkg_destroy(struct blkio_group *blkg)
@@ -249,12 +251,10 @@ static void blkg_destroy(struct blkio_group *blkg) 
/**

 * blkg_destroy_all - destroy all blkgs associated with a request_queue

 * @q: request_queue of interest

 * @destroy_root: whether to destroy root blkg or not

 *

 * Destroy blkgs associated with @q.  If @destroy_root is %true, all are

 * destroyed; otherwise, root blkg is left alone.

 * Destroy all blkgs associated with @q.

 */

void blkg_destroy_all(struct request_queue *q, bool destroy_root)

static void blkg_destroy_all(struct request_queue *q)

{

	struct blkio_group *blkg, *n;
@@ -263,10 +263,6 @@ void blkg_destroy_all(struct request_queue *q, bool destroy_root) 
	list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {

		struct blkio_cgroup *blkcg = blkg->blkcg;



		/* skip root? */

		if (!destroy_root && blkg->blkcg == &blkio_root_cgroup)

			continue;



		spin_lock(&blkcg->lock);

		blkg_destroy(blkg);

		spin_unlock(&blkcg->lock);
@@ -274,7 +270,6 @@ void blkg_destroy_all(struct request_queue *q, bool destroy_root) 


	spin_unlock_irq(q->queue_lock);

}

EXPORT_SYMBOL_GPL(blkg_destroy_all);



static void blkg_rcu_free(struct rcu_head *rcu_head)

{
@@ -492,7 +487,7 @@ int blkg_conf_prep(struct blkio_cgroup *blkcg, 
	spin_lock_irq(disk->queue->queue_lock);



	if (blkcg_policy_enabled(disk->queue, pol))

		blkg = blkg_lookup_create(blkcg, disk->queue, false);

		blkg = blkg_lookup_create(blkcg, disk->queue);

	else

		blkg = ERR_PTR(-EINVAL);
@@ -625,20 +620,9 @@ done: 
 */

int blkcg_init_queue(struct request_queue *q)

{

	int ret;



	might_sleep();



	ret = blk_throtl_init(q);

	if (ret)

		return ret;



	mutex_lock(&all_q_mutex);

	INIT_LIST_HEAD(&q->all_q_node);

	list_add_tail(&q->all_q_node, &all_q_list);

	mutex_unlock(&all_q_mutex);



	return 0;

	return blk_throtl_init(q);

}



/**
@@ -662,12 +646,7 @@ void blkcg_drain_queue(struct request_queue *q) 
 */

void blkcg_exit_queue(struct request_queue *q)

{

	mutex_lock(&all_q_mutex);

	list_del_init(&q->all_q_node);

	mutex_unlock(&all_q_mutex);



	blkg_destroy_all(q, true);



	blkg_destroy_all(q);

	blk_throtl_exit(q);

}
@@ -741,7 +720,7 @@ int blkcg_activate_policy(struct request_queue *q, 
	spin_lock_irq(q->queue_lock);



	rcu_read_lock();

	blkg = blkg_lookup_create(&blkio_root_cgroup, q, true);

	blkg = __blkg_lookup_create(&blkio_root_cgroup, q);

	rcu_read_unlock();



	if (IS_ERR(blkg)) {

block/blk-cgroup.h

+1 −5
Original line number Diff line number Diff line
@@ -115,7 +115,6 @@ extern int blkcg_activate_policy(struct request_queue *q, 
				 const struct blkio_policy_type *pol);

extern void blkcg_deactivate_policy(struct request_queue *q,

				    const struct blkio_policy_type *pol);

extern void blkg_destroy_all(struct request_queue *q, bool destroy_root);



void blkcg_print_blkgs(struct seq_file *sf, struct blkio_cgroup *blkcg,

		       u64 (*prfill)(struct seq_file *, void *, int),
@@ -334,8 +333,6 @@ static inline int blkcg_activate_policy(struct request_queue *q, 
					const struct blkio_policy_type *pol) { return 0; }

static inline void blkcg_deactivate_policy(struct request_queue *q,

					   const struct blkio_policy_type *pol) { }

static inline void blkg_destroy_all(struct request_queue *q,

				    bool destory_root) { }



static inline void *blkg_to_pdata(struct blkio_group *blkg,

				struct blkio_policy_type *pol) { return NULL; }
@@ -354,8 +351,7 @@ extern struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio); 
extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,

				       struct request_queue *q);

struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,

				       struct request_queue *q,

				       bool for_root);

				       struct request_queue *q);

#else

struct cgroup;

static inline struct blkio_cgroup *

block/blk-throttle.c

+1 −1
Original line number Diff line number Diff line
@@ -285,7 +285,7 @@ static struct throtl_grp *throtl_lookup_create_tg(struct throtl_data *td, 
	} else {

		struct blkio_group *blkg;



		blkg = blkg_lookup_create(blkcg, q, false);

		blkg = blkg_lookup_create(blkcg, q);



		/* if %NULL and @q is alive, fall back to root_tg */

		if (!IS_ERR(blkg))

block/cfq-iosched.c

+1 −1
Original line number Diff line number Diff line
@@ -1348,7 +1348,7 @@ static struct cfq_group *cfq_lookup_create_cfqg(struct cfq_data *cfqd, 
	} else {

		struct blkio_group *blkg;



		blkg = blkg_lookup_create(blkcg, q, false);

		blkg = blkg_lookup_create(blkcg, q);

		if (!IS_ERR(blkg))

			cfqg = blkg_to_cfqg(blkg);

	}

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