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From: Tejun Heo <tj@kernel.org>
To: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, 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 v4] blk-mq: Fix race conditions in request timeout handling
Date: Tue, 10 Apr 2018 07:20:28 -0700	[thread overview]
Message-ID: <20180410142028.GM3126663@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20180410013455.7448-1-bart.vanassche@wdc.com>

Hello, Bart.

On Mon, Apr 09, 2018 at 06:34:55PM -0700, Bart Van Assche wrote:
> Since the request state can be updated from two different contexts,
> namely regular completion and request timeout, this race cannot be
> fixed with RCU synchronization only. Fix this race as follows:

Well, it can be and the patches have been posted months ago.  It just
needed a repro case to confirm the fix, which we now seem to have.

Switching to another model might be better but let's please do that
with the right rationales.  A good portion of this seems to be built
on misunderstandings.

Thanks.

-- 
tejun

  parent reply	other threads:[~2018-04-10 14:20 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10  1:34 [PATCH v4] blk-mq: Fix race conditions in request timeout handling Bart Van Assche
2018-04-10  7:59 ` jianchao.wang
2018-04-10 10:04   ` Ming Lei
2018-04-10 12:04     ` Shan Hai
2018-04-10 13:01   ` Bart Van Assche
2018-04-10 14:32     ` jianchao.wang
2018-04-10  8:41 ` Ming Lei
2018-04-10 12:58   ` Bart Van Assche
2018-04-10 13:55     ` Ming Lei
2018-04-10 14:09       ` Bart Van Assche
2018-04-10 14:30         ` Ming Lei
2018-04-10 15:02           ` Bart Van Assche
2018-04-10 15:25             ` Ming Lei
2018-04-10 15:30               ` tj
2018-04-10 15:38                 ` Ming Lei
2018-04-10 15:40                   ` tj
2018-04-10 21:33                     ` tj
2018-04-10 21:46                       ` Bart Van Assche
2018-04-10 21:54                         ` tj
2018-04-11 12:50                           ` Bart Van Assche
2018-04-11 14:16                             ` tj
2018-04-11 18:38                             ` Martin Steigerwald
2018-04-11 14:24                           ` Sagi Grimberg
2018-04-11 14:43                             ` tj
2018-04-11 16:16                             ` Israel Rukshin
2018-04-11 17:07                               ` tj
2018-04-11 21:31                                 ` tj
2018-04-12  8:59                                   ` Israel Rukshin
2018-04-12 13:35                                     ` tj
2018-04-15 12:28                                       ` Israel Rukshin
2018-04-18 16:34                           ` Bart Van Assche
2018-04-10  9:55 ` Christoph Hellwig
2018-04-10 13:26   ` Bart Van Assche
2018-04-10 14:50     ` hch
2018-04-10 14:41   ` Jens Axboe
2018-04-10 14:20 ` Tejun Heo [this message]
2018-04-10 14:30   ` Bart Van Assche
2018-04-10 14:33     ` tj

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