blk-mq: cleanup disk sysfs registration

Pass a gendisk to the sysfs register/unregister functions and give
them descriptive names.  Also move the unregistration helper next
to the one doing the registration.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220628171850.1313069-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-sysfs.c

@@ -203,22 +203,6 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 	return ret;
 }
 
-void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
-{
-	struct blk_mq_hw_ctx *hctx;
-	unsigned long i;
-
-	lockdep_assert_held(&q->sysfs_dir_lock);
-
-	queue_for_each_hw_ctx(q, hctx, i)
-		blk_mq_unregister_hctx(hctx);
-
-	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
-	kobject_del(q->mq_kobj);
-
-	q->mq_sysfs_init_done = false;
-}
-
 void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
 {
 	kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
@@ -251,16 +235,16 @@ void blk_mq_sysfs_init(struct request_queue *q)
 	}
 }
 
-int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
+int blk_mq_sysfs_register(struct gendisk *disk)
 {
+	struct request_queue *q = disk->queue;
 	struct blk_mq_hw_ctx *hctx;
 	unsigned long i, j;
 	int ret;
 
-	WARN_ON_ONCE(!q->kobj.parent);
 	lockdep_assert_held(&q->sysfs_dir_lock);
 
-	ret = kobject_add(q->mq_kobj, &dev->kobj, "%s", "mq");
+	ret = kobject_add(q->mq_kobj, &disk_to_dev(disk)->kobj, "mq");
 	if (ret < 0)
 		goto out;
 
@@ -288,6 +272,23 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 	return ret;
 }
 
+void blk_mq_sysfs_unregister(struct gendisk *disk)
+{
+	struct request_queue *q = disk->queue;
+	struct blk_mq_hw_ctx *hctx;
+	unsigned long i;
+
+	lockdep_assert_held(&q->sysfs_dir_lock);
+
+	queue_for_each_hw_ctx(q, hctx, i)
+		blk_mq_unregister_hctx(hctx);
+
+	kobject_uevent(q->mq_kobj, KOBJ_REMOVE);
+	kobject_del(q->mq_kobj);
+
+	q->mq_sysfs_init_done = false;
+}
+
 void blk_mq_sysfs_unregister_hctxs(struct request_queue *q)
 {
 	struct blk_mq_hw_ctx *hctx;

block/blk-mq.h

@@ -118,7 +118,8 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  */
 extern void blk_mq_sysfs_init(struct request_queue *q);
 extern void blk_mq_sysfs_deinit(struct request_queue *q);
-extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
+int blk_mq_sysfs_register(struct gendisk *disk);
+void blk_mq_sysfs_unregister(struct gendisk *disk);
 int blk_mq_sysfs_register_hctxs(struct request_queue *q);
 void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);

block/blk-sysfs.c

@@ -812,18 +812,17 @@ struct kobj_type blk_queue_ktype = {
  */
 int blk_register_queue(struct gendisk *disk)
 {
-	int ret;
-	struct device *dev = disk_to_dev(disk);
 	struct request_queue *q = disk->queue;
+	int ret;
 
 	mutex_lock(&q->sysfs_dir_lock);
 
-	ret = kobject_add(&q->kobj, &dev->kobj, "%s", "queue");
+	ret = kobject_add(&q->kobj, &disk_to_dev(disk)->kobj, "queue");
 	if (ret < 0)
 		goto unlock;
 
 	if (queue_is_mq(q))
-		__blk_mq_register_dev(dev, q);
+		blk_mq_sysfs_register(disk);
 	mutex_lock(&q->sysfs_lock);
 
 	mutex_lock(&q->debugfs_mutex);
@@ -919,7 +918,7 @@ void blk_unregister_queue(struct gendisk *disk)
 	 * structures that can be modified through sysfs.
 	 */
 	if (queue_is_mq(q))
-		blk_mq_unregister_dev(disk_to_dev(disk), q);
+		blk_mq_sysfs_unregister(disk);
 	blk_crypto_sysfs_unregister(q);
 
 	mutex_lock(&q->sysfs_lock);

include/linux/blk-mq.h

@@ -691,7 +691,6 @@ struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q,
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 		struct request_queue *q);
-void blk_mq_unregister_dev(struct device *, struct request_queue *);
 void blk_mq_destroy_queue(struct request_queue *);
 
 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);