From: Ming Lei <ming.lei@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org,
Bart Van Assche <bart.vanassche@wdc.com>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
Israel Rukshin <israelr@mellanox.com>,
Max Gurtovoy <maxg@mellanox.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] blk-mq: fix race between complete and BLK_EH_RESET_TIMER
Date: Thu, 12 Apr 2018 06:43:45 +0800 [thread overview]
Message-ID: <20180411224344.GA31433@ming.t460p> (raw)
In-Reply-To: <20180411213007.GR793541@devbig577.frc2.facebook.com>
On Wed, Apr 11, 2018 at 02:30:07PM -0700, Tejun Heo wrote:
> Hello, Ming.
>
> On Thu, Apr 12, 2018 at 04:55:29AM +0800, Ming Lei wrote:
> ...
> > + spin_lock_irqsave(req->q->queue_lock, flags);
> > + if (blk_mq_rq_state(req) != MQ_RQ_COMPLETE_IN_RESET) {
> > + blk_mq_rq_update_aborted_gstate(req, 0);
> > + blk_add_timer(req);
>
> Nothing prevents the above blk_add_timer() racing against the next
> recycle instance of the request, so this still leaves a small race
> window.
OK.
But this small race window can be avoided by running blk_add_timer(req)
before blk_mq_rq_update_aborted_gstate(req, 0), can't it?
--
Ming
next prev parent reply other threads:[~2018-04-11 22:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-11 20:55 [PATCH] blk-mq: fix race between complete and BLK_EH_RESET_TIMER Ming Lei
2018-04-11 21:30 ` Tejun Heo
2018-04-11 22:43 ` Ming Lei [this message]
2018-04-11 22:47 ` Tejun Heo
2018-04-11 23:05 ` Ming Lei
2018-04-12 13:57 ` Tejun Heo
2018-04-13 15:38 ` Ming Lei
2018-04-11 22:49 ` Bart Van Assche
2018-04-11 23:06 ` Ming Lei
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