From 89ed5fa3b5419f04452051fbcb6d3e5b801cdb1b Mon Sep 17 00:00:00 2001 From: Nilay Shroff Date: Wed, 19 Mar 2025 16:23:45 +0530 Subject: [PATCH] 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: 245618f8e45f ("block: protect wbt_lat_usec using q->elevator_lock") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202503171650.cc082b66-lkp@intel.com Signed-off-by: Nilay Shroff Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20250319105518.468941-2-nilay@linux.ibm.com Signed-off-by: Jens Axboe --- block/blk-iocost.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 38e7bf3c3b4f..56e6fb51316d 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -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);