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

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
......@@ -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 (IS_ERR(blkg)) {
blkg = ret_blkg;
break;
}
if (pos == blkcg)
return blkg;
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;
}
......
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