blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/

commit beab17fc2a507e85dd18b3cef83820c5770c5f34 upstream.

io.weight is gonna be another rq_qos cgroup mechanism.  Let's rename
RQ_QOS_CGROUP which is being used by io.latency to RQ_QOS_LATENCY in
preparation.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
[Jiufei: remove unused function rq_qos_id_to_name()]
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

block/blk-iolatency.c

@@ -693,7 +693,7 @@ int blk_iolatency_init(struct request_queue *q)
 		return -ENOMEM;
 
 	rqos = &blkiolat->rqos;
-	rqos->id = RQ_QOS_CGROUP;
+	rqos->id = RQ_QOS_LATENCY;
 	rqos->ops = &blkcg_iolatency_ops;
 	rqos->q = q;
 

block/blk-rq-qos.h

@@ -9,7 +9,7 @@
 
 enum rq_qos_id {
 	RQ_QOS_WBT,
-	RQ_QOS_CGROUP,
+	RQ_QOS_LATENCY,
 };
 
 struct rq_wait {
@@ -65,7 +65,7 @@ static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
 
 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
 {
-	return rq_qos_id(q, RQ_QOS_CGROUP);
+	return rq_qos_id(q, RQ_QOS_LATENCY);
 }
 
 static inline void rq_wait_init(struct rq_wait *rq_wait)