elv_iosched_store(): fix strstrip() misuse
KOSAKI Motohiro [Fri, 9 Oct 2009 06:48:08 +0000 (08:48 +0200)]
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

index 1975b61..a847046 100644 (file)
@@ -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;