block/rq_qos: add rq_qos_merge()

Add a merge hook for rq_qos.  This will be used by io.weight.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 9 insertions, 0 deletions

diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 2300e038b9fa..8e426a8505b6 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -35,6 +35,7 @@ struct rq_qos {
 struct rq_qos_ops {
         void (*throttle)(struct rq_qos *, struct bio *);
         void (*track)(struct rq_qos *, struct request *, struct bio *);
+        void (*merge)(struct rq_qos *, struct request *, struct bio *);
         void (*issue)(struct rq_qos *, struct request *);
         void (*requeue)(struct rq_qos *, struct request *);
         void (*done)(struct rq_qos *, struct request *);
@@ -135,6 +136,7 @@ void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
+void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
 
 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
@@ -185,6 +187,13 @@ static inline void rq_qos_track(struct request_queue *q, struct request *rq,
                 __rq_qos_track(q->rq_qos, rq, bio);
 }
 
+static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
+                                struct bio *bio)
+{
+        if (q->rq_qos)
+                __rq_qos_merge(q->rq_qos, rq, bio);
+}
+
 void rq_qos_exit(struct request_queue *);
 
 #endif