[PATCH 6.1.y] block: fix resource leak in blk_register_queue() error path

[Robert Garcia]

From: Zheng Qixing <zhengqixing@xxxxxxxxxx>

[ Upstream commit 40f2eb9b531475dd01b683fdaf61ca3cfd03a51e ]

When registering a queue fails after blk_mq_sysfs_register() is
successful but the function later encounters an error, we need
to clean up the blk_mq_sysfs resources.

Add the missing blk_mq_sysfs_unregister() call in the error path
to properly clean up these resources and prevent a memory leak.

Fixes: 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism")
Signed-off-by: Zheng Qixing <zhengqixing@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250412092554.475218-1-zhengqixing@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
[ Minor context change fixed. ]
Signed-off-by: Robert Garcia <rob_garcia@xxxxxxx>
---
 block/blk-sysfs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index c74e8273511a..c2418e9fb45a 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -867,6 +867,8 @@ int blk_register_queue(struct gendisk *disk)
 	elv_unregister_queue(q);
 	disk_unregister_independent_access_ranges(disk);
 	mutex_unlock(&q->sysfs_lock);
+	if (queue_is_mq(q))
+		blk_mq_sysfs_unregister(disk);
 	mutex_unlock(&q->sysfs_dir_lock);
 	kobject_del(&q->kobj);
 
-- 
2.34.1