linux-kernel - [PATCH 1/6] blk-mq: make blk_mq_stop_hw_queue() reliably block queue processing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1403104872-22236-2-git-send-email-tj@kernel.org>
Date:	Wed, 18 Jun 2014 11:21:07 -0400
From:	Tejun Heo <tj@...nel.org>
To:	axboe@...nel.dk
Cc:	linux-kernel@...r.kernel.org, kmo@...erainc.com,
	nab@...ux-iscsi.org, Tejun Heo <tj@...nel.org>
Subject: [PATCH 1/6] blk-mq: make blk_mq_stop_hw_queue() reliably block queue processing

blk_mq_stop_hw_queue() has the following two issues.

* BLK_MQ_S_STOPPED should be set before canceling the work items;
  otherwise, a new instance may proceed beyond STOPPED checking
  inbetween.

* cancel_delayed_work() doesn't do anything to work instance already
  executing.  Use cancel_delayed_work_sync() to ensure that the
  currently in-flight one is finished.

Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Nicholas A. Bellinger <nab@...ux-iscsi.org>
---
 block/blk-mq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e11f5f8..4787c3d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -862,9 +862,9 @@ EXPORT_SYMBOL(blk_mq_run_queues);
 
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
 {
-	cancel_delayed_work(&hctx->run_work);
-	cancel_delayed_work(&hctx->delay_work);
 	set_bit(BLK_MQ_S_STOPPED, &hctx->state);
+	cancel_delayed_work_sync(&hctx->run_work);
+	cancel_delayed_work_sync(&hctx->delay_work);
 }
 EXPORT_SYMBOL(blk_mq_stop_hw_queue);
 
-- 
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/