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From: Omar Sandoval <osandov@osandov.com>
To: Jens Axboe <axboe@fb.com>, linux-block@vger.kernel.org
Cc: kernel-team@fb.com
Subject: [PATCH v2 3/3] block: fix leak of q->rq_wb
Date: Tue, 28 Mar 2017 16:12:17 -0700	[thread overview]
Message-ID: <a1688be84c82d71a04e9a0cb0b9c38e02fd921a3.1490742717.git.osandov@fb.com> (raw)
In-Reply-To: <91d938665e5386f10f8756ee8c7ef3e6496ea260.1490742717.git.osandov@fb.com>
In-Reply-To: <91d938665e5386f10f8756ee8c7ef3e6496ea260.1490742717.git.osandov@fb.com>

From: Omar Sandoval <osandov@fb.com>

CONFIG_DEBUG_TEST_DRIVER_REMOVE found a possible leak of q->rq_wb when a
request queue is reregistered. This has been a problem since wbt was
introduced, but the WARN_ON(!list_empty(&stats->callbacks)) in the
blk-stat rework exposed it. Fix it by cleaning up wbt when we unregister
the queue.

Fixes: 87760e5eef35 ("block: hook up writeback throttling")
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 block/blk-sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 833fb7f9ce9d..45854266e398 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -795,7 +795,6 @@ static void blk_release_queue(struct kobject *kobj)
 	struct request_queue *q =
 		container_of(kobj, struct request_queue, kobj);
 
-	wbt_exit(q);
 	if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
 		blk_stat_remove_callback(q, q->poll_cb);
 	blk_stat_free_callback(q->poll_cb);
@@ -938,6 +937,9 @@ void blk_unregister_queue(struct gendisk *disk)
 
 	queue_flag_clear_unlocked(QUEUE_FLAG_REGISTERED, q);
 
+	wbt_exit(q);
+
+
 	if (q->mq_ops)
 		blk_mq_unregister_dev(disk_to_dev(disk), q);
 
-- 
2.12.1

  parent reply	other threads:[~2017-03-28 23:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-28 23:12 [PATCH v2 1/3] block: warn if sharing request queue across gendisks Omar Sandoval
2017-03-28 23:12 ` [PATCH v2 2/3] blk-mq: fix leak of q->stats Omar Sandoval
2017-03-28 23:12 ` Omar Sandoval [this message]
2017-03-29 14:10 ` [PATCH v2 1/3] block: warn if sharing request queue across gendisks Jens Axboe
2017-03-29 17:06   ` Omar Sandoval

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