[PATCH] elevator: elv_list_lock does not need irq disabling

It's never grabbed from irq context, so just make it plain spin_lock().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/elevator.c

@@ -134,13 +134,13 @@ static struct elevator_type *elevator_get(const char *name)
 {
 	struct elevator_type *e;
 
-	spin_lock_irq(&elv_list_lock);
+	spin_lock(&elv_list_lock);
 
 	e = elevator_find(name);
 	if (e && !try_module_get(e->elevator_owner))
 		e = NULL;
 
-	spin_unlock_irq(&elv_list_lock);
+	spin_unlock(&elv_list_lock);
 
 	return e;
 }
@@ -965,10 +965,11 @@ void elv_unregister_queue(struct request_queue *q)
 int elv_register(struct elevator_type *e)
 {
 	char *def = "";
-	spin_lock_irq(&elv_list_lock);
+
+	spin_lock(&elv_list_lock);
 	BUG_ON(elevator_find(e->elevator_name));
 	list_add_tail(&e->list, &elv_list);
-	spin_unlock_irq(&elv_list_lock);
+	spin_unlock(&elv_list_lock);
 
 	if (!strcmp(e->elevator_name, chosen_elevator) ||
 			(!*chosen_elevator &&
@@ -998,9 +999,9 @@ void elv_unregister(struct elevator_type *e)
 		read_unlock(&tasklist_lock);
 	}
 
-	spin_lock_irq(&elv_list_lock);
+	spin_lock(&elv_list_lock);
 	list_del_init(&e->list);
-	spin_unlock_irq(&elv_list_lock);
+	spin_unlock(&elv_list_lock);
 }
 EXPORT_SYMBOL_GPL(elv_unregister);
 
@@ -1118,7 +1119,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 	struct list_head *entry;
 	int len = 0;
 
-	spin_lock_irq(&elv_list_lock);
+	spin_lock(&elv_list_lock);
 	list_for_each(entry, &elv_list) {
 		struct elevator_type *__e;
 
@@ -1128,7 +1129,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 		else
 			len += sprintf(name+len, "%s ", __e->elevator_name);
 	}
-	spin_unlock_irq(&elv_list_lock);
+	spin_unlock(&elv_list_lock);
 
 	len += sprintf(len+name, "\n");
 	return len;