On 7/17/20 3:23 AM, yangerkun wrote: > Once .queue_rq return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE, we will > insert the rq back to list, and will return false since '(!list_empty)' > always be true. The latter check seems unused. This check is already gone in for-5.9/block -- Jens Axboe