From 65d3618ccfe686e8d7b3f01a838d0578182406df Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Thu, 30 Oct 2008 08:53:02 +0100
Subject: block: add comment in blk_rq_timed_out() about why next can not be 0

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
 block/blk-timeout.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 116bbf394fb5..99c3efc706b7 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -132,7 +132,12 @@ void blk_rq_timed_out_timer(unsigned long data)
 		}
 	}
 
-	if (next_set && !list_empty(&q->timeout_list))
+	/*
+	 * next can never be 0 here with the list non-empty, since we always
+	 * bump ->deadline to 1 so we can detect if the timer was ever added
+	 * or not. See comment in blk_add_timer()
+	 */
+	if (next)
 		mod_timer(&q->timeout, round_jiffies_up(next));
 
 	spin_unlock_irqrestore(q->queue_lock, flags);
-- 
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