From: Jens Axboe <jens.axboe@oracle.com>
Date: Thu, 30 Oct 2008 07:53:02 +0000 (+0100)
Subject: block: add comment in blk_rq_timed_out() about why next can not be 0
X-Git-Tag: v2.6.29-rc1~569^2~38
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=65d3618ccfe686e8d7b3f01a838d0578182406df;p=linux-2.6-omap-h63xx.git

block: add comment in blk_rq_timed_out() about why next can not be 0

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

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 116bbf394fb..99c3efc706b 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);