blkcg: Make blkg_root_lookup() work for queues in bypass mode

For legacy queues the only call of blkg_root_lookup() happens after
bypass mode has been enabled. Since blkg_lookup() returns NULL for
queues in bypass mode, modify the blkg_root_lookup() such that it
no longer depends on bypass mode. Rename the function into
blk_queue_root_blkg() as suggested by Tejun.

Suggested-by: Tejun Heo <tj@kernel.org>
Fixes: 6bad9b210a ("blkcg: Introduce blkg_root_lookup()")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bart Van Assche 2018-08-10 13:28:07 -07:00 committed by Jens Axboe
parent 46451874c7
commit b86d865cb1
2 changed files with 6 additions and 11 deletions

View file

@ -813,7 +813,7 @@ static void __blk_release_queue(struct work_struct *work)
blk_exit_queue(q);
}
WARN(blkg_root_lookup(q),
WARN(blk_queue_root_blkg(q),
"request queue %p is being released but it has not yet been removed from the blkcg controller\n",
q);

View file

@ -342,20 +342,14 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
}
/**
* blkg_lookup - look up blkg for the specified request queue
* blk_queue_root_blkg - return blkg for the (blkcg_root, @q) pair
* @q: request_queue of interest
*
* Lookup blkg for @q at the root level. See also blkg_lookup().
*/
static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q)
static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
{
struct blkcg_gq *blkg;
rcu_read_lock();
blkg = blkg_lookup(&blkcg_root, q);
rcu_read_unlock();
return blkg;
return q->root_blkg;
}
/**
@ -881,7 +875,8 @@ static inline bool blk_cgroup_congested(void) { return false; }
static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { }
static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
static inline struct blkcg_gq *blkg_root_lookup(struct request_queue *q) { return NULL; }
static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
{ return NULL; }
static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
static inline void blkcg_drain_queue(struct request_queue *q) { }
static inline void blkcg_exit_queue(struct request_queue *q) { }