blk-iolatency: pass a gendisk to blk_iolatency_init

Pass the gendisk to blk_iolatency_init as part of moving the blk-cgroup
infrastructure to be gendisk based.
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/20220921180501.1539876-9-hch@lst.de
[axboe: missed inline for blk_iolatency_init() and !CONFIG_BLK_CGROUP_IOLATENCY]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-cgroup.c

@@ -1265,7 +1265,7 @@ int blkcg_init_disk(struct gendisk *disk)
 	if (ret)
 		goto err_ioprio_exit;
 
-	ret = blk_iolatency_init(q);
+	ret = blk_iolatency_init(disk);
 	if (ret)
 		goto err_throtl_exit;
 

block/blk-iolatency.c

@@ -756,8 +756,9 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
 	}
 }
 
-int blk_iolatency_init(struct request_queue *q)
+int blk_iolatency_init(struct gendisk *disk)
 {
+	struct request_queue *q = disk->queue;
 	struct blk_iolatency *blkiolat;
 	struct rq_qos *rqos;
 	int ret;

block/blk.h

@@ -389,9 +389,9 @@ static inline struct bio *blk_queue_bounce(struct bio *bio,
 }
 
 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
-extern int blk_iolatency_init(struct request_queue *q);
+int blk_iolatency_init(struct gendisk *disk);
 #else
-static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
+static inline int blk_iolatency_init(struct gendisk *disk) { return 0; };
 #endif
 
 #ifdef CONFIG_BLK_DEV_ZONED