block/blk-rq-qos: cleanup rq_qos_add()

Now that there is no caller of rq_qos_add(), remove it, and also rename
rq_qos_add_frozen() back to rq_qos_add().

Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>

Author: hailan94

block/blk-iocost.c

@@ -2925,7 +2925,7 @@ static int blk_iocost_init(struct gendisk *disk)
 	 * called before policy activation completion, can't assume that the
 	 * target bio has an iocg associated and need to test for NULL iocg.
 	 */
-	ret = rq_qos_add_frozen(&ioc->rqos, disk, RQ_QOS_COST, &ioc_rqos_ops);
+	ret = rq_qos_add(&ioc->rqos, disk, RQ_QOS_COST, &ioc_rqos_ops);
 	if (ret)
 		goto err_free_ioc;
 

block/blk-iolatency.c

@@ -764,8 +764,8 @@ static int blk_iolatency_init(struct gendisk *disk)
 	if (!blkiolat)
 		return -ENOMEM;
 
-	ret = rq_qos_add_frozen(&blkiolat->rqos, disk, RQ_QOS_LATENCY,
-				&blkcg_iolatency_ops);
+	ret = rq_qos_add(&blkiolat->rqos, disk, RQ_QOS_LATENCY,
+			 &blkcg_iolatency_ops);
 	if (ret)
 		goto err_free;
 	ret = blkcg_activate_policy(disk, &blkcg_policy_iolatency);

block/blk-rq-qos.c

@@ -322,8 +322,8 @@ void rq_qos_exit(struct request_queue *q)
 	mutex_unlock(&q->rq_qos_mutex);
 }
 
-int rq_qos_add_frozen(struct rq_qos *rqos, struct gendisk *disk,
-		      enum rq_qos_id id, const struct rq_qos_ops *ops)
+int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
+	       const struct rq_qos_ops *ops)
 {
 	struct request_queue *q = disk->queue;
 
@@ -343,37 +343,6 @@ int rq_qos_add_frozen(struct rq_qos *rqos, struct gendisk *disk,
 	return 0;
 }
 
-int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
-		const struct rq_qos_ops *ops)
-{
-	struct request_queue *q = disk->queue;
-	unsigned int memflags;
-
-	lockdep_assert_held(&q->rq_qos_mutex);
-
-	rqos->disk = disk;
-	rqos->id = id;
-	rqos->ops = ops;
-
-	/*
-	 * No IO can be in-flight when adding rqos, so freeze queue, which
-	 * is fine since we only support rq_qos for blk-mq queue.
-	 */
-	memflags = blk_mq_freeze_queue(q);
-
-	if (rq_qos_id(q, rqos->id))
-		goto ebusy;
-	rqos->next = q->rq_qos;
-	q->rq_qos = rqos;
-	blk_queue_flag_set(QUEUE_FLAG_QOS_ENABLED, q);
-
-	blk_mq_unfreeze_queue(q, memflags);
-	return 0;
-ebusy:
-	blk_mq_unfreeze_queue(q, memflags);
-	return -EBUSY;
-}
-
 void rq_qos_del(struct rq_qos *rqos)
 {
 	struct request_queue *q = rqos->disk->queue;

block/blk-rq-qos.h

@@ -87,8 +87,6 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
 
 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
 		const struct rq_qos_ops *ops);
-int rq_qos_add_frozen(struct rq_qos *rqos, struct gendisk *disk,
-		      enum rq_qos_id id, const struct rq_qos_ops *ops);
 void rq_qos_del(struct rq_qos *rqos);
 
 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);

block/blk-wbt.c

@@ -966,7 +966,7 @@ static int wbt_init(struct gendisk *disk, struct rq_wb *rwb)
 	 * Assign rwb and add the stats callback.
 	 */
 	mutex_lock(&q->rq_qos_mutex);
-	ret = rq_qos_add_frozen(&rwb->rqos, disk, RQ_QOS_WBT, &wbt_rqos_ops);
+	ret = rq_qos_add(&rwb->rqos, disk, RQ_QOS_WBT, &wbt_rqos_ops);
 	mutex_unlock(&q->rq_qos_mutex);
 	if (ret)
 		return ret;