blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()

Because this helper is only used by iocost and iolatency, while they
don't have debugfs entries.

Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: hailan94

block/blk-mq-debugfs.c

@@ -734,16 +734,6 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
 	return "unknown";
 }
 
-void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
-{
-	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
-
-	if (!rqos->disk->queue->debugfs_dir)
-		return;
-	debugfs_remove_recursive(rqos->debugfs_dir);
-	rqos->debugfs_dir = NULL;
-}
-
 static void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 {
 	struct request_queue *q = rqos->disk->queue;

block/blk-mq-debugfs.h

@@ -34,7 +34,6 @@ void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
 void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
 
 void blk_mq_debugfs_register_rq_qos(struct request_queue *q);
-void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos);
 #else
 static inline void blk_mq_debugfs_register(struct request_queue *q)
 {
@@ -78,9 +77,6 @@ static inline void blk_mq_debugfs_register_rq_qos(struct request_queue *q)
 {
 }
 
-static inline void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
-{
-}
 #endif
 
 #if defined(CONFIG_BLK_DEV_ZONED) && defined(CONFIG_BLK_DEBUG_FS)

block/blk-rq-qos.c

@@ -371,8 +371,4 @@ void rq_qos_del(struct rq_qos *rqos)
 	if (!q->rq_qos)
 		blk_queue_flag_clear(QUEUE_FLAG_QOS_ENABLED, q);
 	blk_mq_unfreeze_queue(q, memflags);
-
-	mutex_lock(&q->debugfs_mutex);
-	blk_mq_debugfs_unregister_rqos(rqos);
-	mutex_unlock(&q->debugfs_mutex);
 }