From cc56694f132a8f5fa9334e3afe990de8c3378866 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Mon, 17 Dec 2018 09:46:00 +0800
Subject: blk-mq-debugfs: support rq_qos

blk-mq-debugfs has been proved as very helpful for debug some
tough issues, such as IO hang.

We have seen blk-wbt related IO hang several times, even inside
Red Hat BZ, there is such report not sovled yet, so this patch
adds support debugfs on rq_qos.

Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-rq-qos.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'block/blk-rq-qos.c')

diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
index e932ef9d2718..d169d7188fa6 100644
--- a/block/blk-rq-qos.c
+++ b/block/blk-rq-qos.c
@@ -264,6 +264,8 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data,
 
 void rq_qos_exit(struct request_queue *q)
 {
+	blk_mq_debugfs_unregister_queue_rqos(q);
+
 	while (q->rq_qos) {
 		struct rq_qos *rqos = q->rq_qos;
 		q->rq_qos = rqos->next;
-- 
cgit