block: fix error unwinding in blk_register_queue

blk_register_queue fails to handle errors from blk_mq_sysfs_register,
leaks various resources on errors and accidentally sets queue refs percpu
refcount to percpu mode on kobject_add failure.  Fix all that by
properly unwinding on errors.

Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Christoph Hellwig

block/blk-sysfs.c

@@ -823,13 +823,15 @@ int blk_register_queue(struct gendisk *disk)
 	int ret;
 
 	mutex_lock(&q->sysfs_dir_lock);
-
 	ret = kobject_add(&q->kobj, &disk_to_dev(disk)->kobj, "queue");
 	if (ret < 0)
-		goto unlock;
+		goto out_unlock_dir;
 
-	if (queue_is_mq(q))
-		blk_mq_sysfs_register(disk);
+	if (queue_is_mq(q)) {
+		ret = blk_mq_sysfs_register(disk);
+		if (ret)
+			goto out_del_queue_kobj;
+	}
 	mutex_lock(&q->sysfs_lock);
 
 	mutex_lock(&q->debugfs_mutex);
@@ -841,17 +843,17 @@ int blk_register_queue(struct gendisk *disk)
 
 	ret = disk_register_independent_access_ranges(disk);
 	if (ret)
-		goto put_dev;
+		goto out_debugfs_remove;
 
 	if (q->elevator) {
 		ret = elv_register_queue(q, false);
 		if (ret)
-			goto put_dev;
+			goto out_unregister_ia_ranges;
 	}
 
 	ret = blk_crypto_sysfs_register(disk);
 	if (ret)
-		goto put_dev;
+		goto out_elv_unregister;
 
 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
 	wbt_enable_default(q);
@@ -862,8 +864,6 @@ int blk_register_queue(struct gendisk *disk)
 	if (q->elevator)
 		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 	mutex_unlock(&q->sysfs_lock);
-
-unlock:
 	mutex_unlock(&q->sysfs_dir_lock);
 
 	/*
@@ -882,13 +882,17 @@ int blk_register_queue(struct gendisk *disk)
 
 	return ret;
 
-put_dev:
+out_elv_unregister:
 	elv_unregister_queue(q);
+out_unregister_ia_ranges:
 	disk_unregister_independent_access_ranges(disk);
+out_debugfs_remove:
+	blk_debugfs_remove(disk);
 	mutex_unlock(&q->sysfs_lock);
-	mutex_unlock(&q->sysfs_dir_lock);
+out_del_queue_kobj:
 	kobject_del(&q->kobj);
-
+out_unlock_dir:
+	mutex_unlock(&q->sysfs_dir_lock);
 	return ret;
 }