block: exit elv_iosched_show early when I/O schedulers are not supported

If the tag_set has BLK_MQ_F_NO_SCHED flag set we will never show any
scheduler, so exit early.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/block/elevator.c b/block/elevator.c
index d0e48839f676414fb3143669e8abc7d614a0c8b7..92096e5aabd36b971e03004573b2414304b81b37 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -777,7 +777,7 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
        struct elevator_type *__e;
        int len = 0;
 
-       if (!queue_is_mq(q))
+       if (!elv_support_iosched(q))
                return sprintf(name, "none\n");
 
        if (!q->elevator)
@@ -791,8 +791,7 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
                        len += sprintf(name+len, "[%s] ", elv->elevator_name);
                        continue;
                }
-               if (elv_support_iosched(q) &&
-                   elevator_match(__e, __e->elevator_name,
+               if (elevator_match(__e, __e->elevator_name,
                                   q->required_elevator_features))
                        len += sprintf(name+len, "%s ", __e->elevator_name);
        }