[PATCH] block layer: elv_iosched_show should get elv_list_lock

elv_iosched_show function iterates other elv_list, hence
elv_list_lock should be got.

Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Signed-off-by: Vasily Tarasov <jens.axboe@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/elevator.c b/block/elevator.c
index d8030a84773a..8ccd163254b8 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -1085,7 +1085,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
         struct list_head *entry;
         int len = 0;
 
-        spin_lock_irq(q->queue_lock);
+        spin_lock_irq(&elv_list_lock);
         list_for_each(entry, &elv_list) {
                 struct elevator_type *__e;
 
@@ -1095,7 +1095,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
                 else
                         len += sprintf(name+len, "%s ", __e->elevator_name);
         }
-        spin_unlock_irq(q->queue_lock);
+        spin_unlock_irq(&elv_list_lock);
 
         len += sprintf(len+name, "\n");
         return len;