From 8c279598585e4992a41016bb973993ed15888cb3 Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Fri, 9 Oct 2009 08:48:08 +0200
Subject: [PATCH] elv_iosched_store(): fix strstrip() misuse

elv_iosched_store() ignore the return value of strstrip().  It makes small
inconsistent behavior.

This patch fixes it.

 <before>
 ====================================
 # cd /sys/block/{blockdev}/queue

 case1:
 # echo "anticipatory" > scheduler
 # cat scheduler
 noop [anticipatory] deadline cfq

 case2:
 # echo "anticipatory " > scheduler
 # cat scheduler
 noop [anticipatory] deadline cfq

 case3:
 # echo " anticipatory" > scheduler
 bash: echo: write error: Invalid argument

 <after>
 ====================================
 # cd /sys/block/{blockdev}/queue

 case1:
 # echo "anticipatory" > scheduler
 # cat scheduler
 noop [anticipatory] deadline cfq

 case2:
 # echo "anticipatory " > scheduler
 # cat scheduler
 noop [anticipatory] deadline cfq

 case3:
 # echo " anticipatory" > scheduler
 noop [anticipatory] deadline cfq

Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
 block/elevator.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/elevator.c b/block/elevator.c
index 1975b619c86d..a847046c6e53 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -1059,9 +1059,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
 		return count;
 
 	strlcpy(elevator_name, name, sizeof(elevator_name));
-	strstrip(elevator_name);
-
-	e = elevator_get(elevator_name);
+	e = elevator_get(strstrip(elevator_name));
 	if (!e) {
 		printk(KERN_ERR "elevator: type %s not found\n", elevator_name);
 		return -EINVAL;