From: Nilay Shroff Date: Wed, 19 Mar 2025 10:53:45 +0000 (+0530) Subject: block: release q->elevator_lock in ioc_qos_write X-Git-Tag: v6.15-rc1~166^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=89ed5fa3b5419f04452051fbcb6d3e5b801cdb1b;p=thirdparty%2Flinux.git 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 --- diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 38e7bf3c3b4f3..56e6fb51316d9 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);