Commit 8c546287 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: merge blkg_lookup_create and __blkg_lookup_create 



No good reason to keep these two functions split.

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 28fc591f

block/blk-cgroup.c

+18 −31
Original line number Diff line number Diff line
@@ -316,30 +316,35 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, 
}



/**

 * __blkg_lookup_create - lookup blkg, try to create one if not there

 * blkg_lookup_create - lookup blkg, try to create one if not there

 * @blkcg: blkcg of interest

 * @q: request_queue of interest

 *

 * Lookup blkg for the @blkcg - @q pair.  If it doesn't exist, try to

 * create one.  blkg creation is performed recursively from blkcg_root such

 * that all non-root blkg's have access to the parent blkg.  This function

 * should be called under RCU read lock and @q->queue_lock.

 * should be called under RCU read lock and takes @q->queue_lock.

 *

 * Returns the blkg or the closest blkg if blkg_create() fails as it walks

 * down from root.

 */

static 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;

	unsigned long flags;



	WARN_ON_ONCE(!rcu_read_lock_held());

	lockdep_assert_held(&q->queue_lock);



	blkg = __blkg_lookup(blkcg, q, true);

	blkg = blkg_lookup(blkcg, q);

	if (blkg)

		return blkg;



	spin_lock_irqsave(&q->queue_lock, flags);

	blkg = __blkg_lookup(blkcg, q, true);

	if (blkg)

		goto found;



	/*

	 * Create blkgs walking down from blkcg_root to @blkcg, so that all

	 * non-root blkgs have access to their parents.  Returns the closest
@@ -362,34 +367,16 @@ static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, 
		}



		blkg = blkg_create(pos, q, NULL);

		if (IS_ERR(blkg))

			return ret_blkg;

		if (pos == blkcg)

			return blkg;

		if (IS_ERR(blkg)) {

			blkg = ret_blkg;

			break;

		}

		if (pos == blkcg)

			break;

	}



/**

 * blkg_lookup_create - find or create a blkg

 * @blkcg: target block cgroup

 * @q: target request_queue

 *

 * This looks up or creates the blkg representing the unique pair

 * of the blkcg and the request_queue.

 */

static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,

				    struct request_queue *q)

{

	struct blkcg_gq *blkg = blkg_lookup(blkcg, q);



	if (unlikely(!blkg)) {

		unsigned long flags;



		spin_lock_irqsave(&q->queue_lock, flags);

		blkg = __blkg_lookup_create(blkcg, q);

found:

	spin_unlock_irqrestore(&q->queue_lock, flags);

	}



	return blkg;

}