blk-rq-qos: constify rq_qos_ops

These op vectors are constant, so mark them const.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-15-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-iocost.c

@@ -2832,7 +2832,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
 	kfree(ioc);
 }
 
-static struct rq_qos_ops ioc_rqos_ops = {
+static const struct rq_qos_ops ioc_rqos_ops = {
 	.throttle = ioc_rqos_throttle,
 	.merge = ioc_rqos_merge,
 	.done_bio = ioc_rqos_done_bio,

block/blk-iolatency.c

@@ -650,7 +650,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
 	kfree(blkiolat);
 }
 
-static struct rq_qos_ops blkcg_iolatency_ops = {
+static const struct rq_qos_ops blkcg_iolatency_ops = {
 	.throttle = blkcg_iolatency_throttle,
 	.done_bio = blkcg_iolatency_done_bio,
 	.exit = blkcg_iolatency_exit,

block/blk-rq-qos.c

@@ -296,7 +296,7 @@ void rq_qos_exit(struct request_queue *q)
 }
 
 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
-		struct rq_qos_ops *ops)
+		const struct rq_qos_ops *ops)
 {
 	struct request_queue *q = disk->queue;
 

block/blk-rq-qos.h

@@ -25,7 +25,7 @@ struct rq_wait {
 };
 
 struct rq_qos {
-	struct rq_qos_ops *ops;
+	const struct rq_qos_ops *ops;
 	struct request_queue *q;
 	enum rq_qos_id id;
 	struct rq_qos *next;
@@ -86,7 +86,7 @@ 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,
-		struct rq_qos_ops *ops);
+		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

@@ -898,7 +898,7 @@ static const struct blk_mq_debugfs_attr wbt_debugfs_attrs[] = {
 };
 #endif
 
-static struct rq_qos_ops wbt_rqos_ops = {
+static const struct rq_qos_ops wbt_rqos_ops = {
 	.throttle = wbt_wait,
 	.issue = wbt_issue,
 	.track = wbt_track,