Commit 28fc591f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: move the bio cgroup associatation helpers to blk-cgroup.c 



Keep the cgroup code together.

Acked-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a18b9b15

block/bio.c

+0 −75
Original line number Diff line number Diff line
@@ -1627,81 +1627,6 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) 
}

EXPORT_SYMBOL(bioset_init_from_src);



#ifdef CONFIG_BLK_CGROUP

/**

 * bio_associate_blkg_from_css - associate a bio with a specified css

 * @bio: target bio

 * @css: target css

 *

 * Associate @bio with the blkg found by combining the css's blkg and the

 * request_queue of the @bio.  An association failure is handled by walking up

 * the blkg tree.  Therefore, the blkg associated can be anything between @blkg

 * and q->root_blkg.  This situation only happens when a cgroup is dying and

 * then the remaining bios will spill to the closest alive blkg.

 *

 * A reference will be taken on the blkg and will be released when @bio is

 * freed.

 */

void bio_associate_blkg_from_css(struct bio *bio,

				 struct cgroup_subsys_state *css)

{

	struct request_queue *q = bio->bi_disk->queue;

	struct blkcg_gq *blkg = q->root_blkg;



	if (bio->bi_blkg)

		blkg_put(bio->bi_blkg);



	rcu_read_lock();

	if (css && css->parent)

		blkg = blkg_lookup_create(css_to_blkcg(css), q);

	bio->bi_blkg = blkg_tryget_closest(blkg);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);



/**

 * bio_associate_blkg - associate a bio with a blkg

 * @bio: target bio

 *

 * Associate @bio with the blkg found from the bio's css and request_queue.

 * If one is not found, bio_lookup_blkg() creates the blkg.  If a blkg is

 * already associated, the css is reused and association redone as the

 * request_queue may have changed.

 */

void bio_associate_blkg(struct bio *bio)

{

	struct cgroup_subsys_state *css;



	rcu_read_lock();



	if (bio->bi_blkg)

		css = &bio_blkcg(bio)->css;

	else

		css = blkcg_css();



	bio_associate_blkg_from_css(bio, css);



	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(bio_associate_blkg);



/**

 * bio_clone_blkg_association - clone blkg association from src to dst bio

 * @dst: destination bio

 * @src: source bio

 */

void bio_clone_blkg_association(struct bio *dst, struct bio *src)

{

	if (src->bi_blkg) {

		if (dst->bi_blkg)

			blkg_put(dst->bi_blkg);

		blkg_get(src->bi_blkg);

		dst->bi_blkg = src->bi_blkg;

	}

}

EXPORT_SYMBOL_GPL(bio_clone_blkg_association);

#endif /* CONFIG_BLK_CGROUP */



static void __init biovec_init_slabs(void)

{

	int i;

block/blk-cgroup.c

+101 −2
Original line number Diff line number Diff line
@@ -328,7 +328,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, 
 * Returns the blkg or the closest blkg if blkg_create() fails as it walks

 * down from root.

 */

struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,

static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,

				      struct request_queue *q)

{

	struct blkcg_gq *blkg;
@@ -377,7 +377,7 @@ struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, 
 * This looks up or creates the blkg representing the unique pair

 * of the blkcg and the request_queue.

 */

struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,

static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,

				    struct request_queue *q)

{

	struct blkcg_gq *blkg = blkg_lookup(blkcg, q);
@@ -1727,6 +1727,105 @@ void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta) 
	atomic64_add(delta, &blkg->delay_nsec);

}



/**

 * blkg_tryget_closest - try and get a blkg ref on the closet blkg

 * @blkg: blkg to get

 *

 * This needs to be called rcu protected.  As the failure mode here is to walk

 * up the blkg tree, this ensure that the blkg->parent pointers are always

 * valid.  This returns the blkg that it ended up taking a reference on or %NULL

 * if no reference was taken.

 */

static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg)

{

	struct blkcg_gq *ret_blkg = NULL;



	WARN_ON_ONCE(!rcu_read_lock_held());



	while (blkg) {

		if (blkg_tryget(blkg)) {

			ret_blkg = blkg;

			break;

		}

		blkg = blkg->parent;

	}



	return ret_blkg;

}



/**

 * bio_associate_blkg_from_css - associate a bio with a specified css

 * @bio: target bio

 * @css: target css

 *

 * Associate @bio with the blkg found by combining the css's blkg and the

 * request_queue of the @bio.  An association failure is handled by walking up

 * the blkg tree.  Therefore, the blkg associated can be anything between @blkg

 * and q->root_blkg.  This situation only happens when a cgroup is dying and

 * then the remaining bios will spill to the closest alive blkg.

 *

 * A reference will be taken on the blkg and will be released when @bio is

 * freed.

 */

void bio_associate_blkg_from_css(struct bio *bio,

				 struct cgroup_subsys_state *css)

{

	struct request_queue *q = bio->bi_disk->queue;

	struct blkcg_gq *blkg = q->root_blkg;



	if (bio->bi_blkg)

		blkg_put(bio->bi_blkg);



	rcu_read_lock();

	if (css && css->parent)

		blkg = blkg_lookup_create(css_to_blkcg(css), q);

	bio->bi_blkg = blkg_tryget_closest(blkg);

	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);



/**

 * bio_associate_blkg - associate a bio with a blkg

 * @bio: target bio

 *

 * Associate @bio with the blkg found from the bio's css and request_queue.

 * If one is not found, bio_lookup_blkg() creates the blkg.  If a blkg is

 * already associated, the css is reused and association redone as the

 * request_queue may have changed.

 */

void bio_associate_blkg(struct bio *bio)

{

	struct cgroup_subsys_state *css;



	rcu_read_lock();



	if (bio->bi_blkg)

		css = &bio_blkcg(bio)->css;

	else

		css = blkcg_css();



	bio_associate_blkg_from_css(bio, css);



	rcu_read_unlock();

}

EXPORT_SYMBOL_GPL(bio_associate_blkg);



/**

 * bio_clone_blkg_association - clone blkg association from src to dst bio

 * @dst: destination bio

 * @src: source bio

 */

void bio_clone_blkg_association(struct bio *dst, struct bio *src)

{

	if (src->bi_blkg) {

		if (dst->bi_blkg)

			blkg_put(dst->bi_blkg);

		blkg_get(src->bi_blkg);

		dst->bi_blkg = src->bi_blkg;

	}

}

EXPORT_SYMBOL_GPL(bio_clone_blkg_association);



static int __init blkcg_init(void)

{

	blkcg_punt_bio_wq = alloc_workqueue("blkcg_punt_bio",

include/linux/blk-cgroup.h

+0 −30
Original line number Diff line number Diff line
@@ -183,10 +183,6 @@ extern bool blkcg_debug_stats; 


struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,

				      struct request_queue *q, bool update_hint);

struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,

				      struct request_queue *q);

struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,

				    struct request_queue *q);

int blkcg_init_queue(struct request_queue *q);

void blkcg_exit_queue(struct request_queue *q);
@@ -480,32 +476,6 @@ static inline bool blkg_tryget(struct blkcg_gq *blkg) 
	return blkg && percpu_ref_tryget(&blkg->refcnt);

}



/**

 * blkg_tryget_closest - try and get a blkg ref on the closet blkg

 * @blkg: blkg to get

 *

 * This needs to be called rcu protected.  As the failure mode here is to walk

 * up the blkg tree, this ensure that the blkg->parent pointers are always

 * valid.  This returns the blkg that it ended up taking a reference on or %NULL

 * if no reference was taken.

 */

static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg)

{

	struct blkcg_gq *ret_blkg = NULL;



	WARN_ON_ONCE(!rcu_read_lock_held());



	while (blkg) {

		if (blkg_tryget(blkg)) {

			ret_blkg = blkg;

			break;

		}

		blkg = blkg->parent;

	}



	return ret_blkg;

}



/**

 * blkg_put - put a blkg reference

 * @blkg: blkg to put