[RESEND PATCH v2 1/7] block: invoke blk_mq_exit_sched no matter whether have .exit_sched

[Yufen Yu <yuyufen@huawei.com>]

We will register debugfs for scheduler no matter whether it have
defined callback funciton .exit_sched. So, blk_mq_exit_sched()
is always needed to unregister debugfs. Also, q->elevator should
be set as NULL after exiting scheduler.

For now, since all register scheduler have defined .exit_sched,
it will not cause any actual problem. But It will be more reasonable
to do this change.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/blk-sysfs.c | 1 -
 block/elevator.c  | 3 +--
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 7dda709f3ccb..ee2cd4d1054c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -883,7 +883,6 @@ static void blk_exit_queue(struct request_queue *q)
 	if (q->elevator) {
 		ioc_clear_queue(q);
 		__elevator_exit(q, q->elevator);
-		q->elevator = NULL;
 	}
 
 	/*
diff --git a/block/elevator.c b/block/elevator.c
index 90ed7a28c21d..7d76b61e157a 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -191,8 +191,7 @@ static void elevator_release(struct kobject *kobj)
 void __elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
 	mutex_lock(&e->sysfs_lock);
-	if (e->type->ops.exit_sched)
-		blk_mq_exit_sched(q, e);
+	blk_mq_exit_sched(q, e);
 	mutex_unlock(&e->sysfs_lock);
 
 	kobject_put(&e->kobj);
-- 
2.25.4