From c06bc5a3fb42304d815a2dc41e324b5a97c9f7da Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Sun, 27 Jun 2021 14:11:12 -0700 Subject: [PATCH] block/mq-deadline: Remove a WARN_ON_ONCE() call The purpose of the WARN_ON_ONCE() statement in dd_insert_request() is to verify that dd_prepare_request() cleared rq->elv.priv[0]. Since dd_prepare_request() is called during request initialization but not if a request is requeued, a warning is triggered if a request is requeued. Fix this by removing the WARN_ON_ONCE() statement. This patch suppresses the following kernel warning: WARNING: CPU: 28 PID: 432 at block/mq-deadline-main.c:740 dd_insert_request+0x4d4/0x5b0 Workqueue: kblockd blk_mq_requeue_work Call Trace: dd_insert_requests+0xfa/0x130 blk_mq_sched_insert_request+0x22c/0x240 blk_mq_requeue_work+0x21c/0x2d0 process_one_work+0x4c2/0xa70 worker_thread+0x2e5/0x6d0 kthread+0x21c/0x250 ret_from_fork+0x1f/0x30 Reported-by: Sachin Sant Fixes: 08a9ad8bf607 ("block/mq-deadline: Add cgroup support") Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20210627211112.12720-1-bvanassche@acm.org Signed-off-by: Jens Axboe --- block/mq-deadline-main.c | 1 - 1 file changed, 1 deletion(-) diff --git a/block/mq-deadline-main.c b/block/mq-deadline-main.c index 9db6da9ef4c6..6f612e6dc82b 100644 --- a/block/mq-deadline-main.c +++ b/block/mq-deadline-main.c @@ -740,7 +740,6 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, dd_count(dd, inserted, prio); blkcg = dd_blkcg_from_bio(rq->bio); ddcg_count(blkcg, inserted, ioprio_class); - WARN_ON_ONCE(rq->elv.priv[0]); rq->elv.priv[0] = blkcg; if (blk_mq_sched_try_insert_merge(q, rq, &free)) {