block: release q->elevator_lock in ioc_qos_write

The ioc_qos_write method acquires q->elevator_lock to protect
updates to blk-wbt parameters. Once these updates are complete,
the lock should be released before returning from ioc_qos_write.

However, in one code path, the release of q->elevator_lock was
mistakenly omitted, potentially leading to a lock leak. This commit
fixes the issue by ensuring that q->elevator_lock is properly
released in all return paths of ioc_qos_write.

Fixes: 245618f8e4 ("block: protect wbt_lat_usec using q->elevator_lock")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202503171650.cc082b66-lkp@intel.com
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250319105518.468941-2-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Nilay Shroff 2025-03-19 16:23:45 +05:30 committed by Jens Axboe
parent 989bcd623a
commit 89ed5fa3b5

View File

@ -3348,6 +3348,7 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
wbt_enable_default(disk);
blk_mq_unquiesce_queue(disk->queue);
mutex_unlock(&disk->queue->elevator_lock);
blk_mq_unfreeze_queue(disk->queue, memflags);
blkg_conf_exit(&ctx);