From eb130dbfc40eabcd4e10797310bda6b9f6dd7e76 Mon Sep 17 00:00:00 2001
From: Keith Busch <keith.busch@intel.com>
Date: Thu, 8 Jan 2015 08:59:53 -0700
Subject: blk-mq: End unstarted requests on a dying queue

Requests that haven't been started prior to a queue dying can be ended
in error without waiting for them to start and time out.

Signed-off-by: Keith Busch <keith.busch@intel.com>

Added code comment to explain why this is done.

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 78324a2..2f95747 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -625,8 +625,17 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
 {
 	struct blk_mq_timeout_data *data = priv;
 
-	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
+		/*
+		 * If a request wasn't started before the queue was
+		 * marked dying, kill it here or it'll go unnoticed.
+		 */
+		if (unlikely(blk_queue_dying(rq->q))) {
+			rq->errors = -EIO;
+			blk_mq_complete_request(rq);
+		}
 		return;
+	}
 	if (rq->cmd_flags & REQ_NO_TIMEOUT)
 		return;
 
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