All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>,
	Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	Tejun Heo <tj@kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
	Israel Rukshin <israelr@mellanox.com>,
	Max Gurtovoy <maxg@mellanox.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH v5] blk-mq: Avoid that a completion can be ignored for BLK_EH_RESET_TIMER
Date: Thu, 12 Apr 2018 15:21:37 +0200	[thread overview]
Message-ID: <20180412132137.GB5476@lst.de> (raw)
In-Reply-To: <20180411021104.GC4494@ming.t460p>

On Wed, Apr 11, 2018 at 10:11:05AM +0800, Ming Lei wrote:
> On Tue, Apr 10, 2018 at 03:01:57PM -0600, Bart Van Assche wrote:
> > The blk-mq timeout handling code ignores completions that occur after
> > blk_mq_check_expired() has been called and before blk_mq_rq_timed_out()
> > has reset rq->aborted_gstate. If a block driver timeout handler always
> > returns BLK_EH_RESET_TIMER then the result will be that the request
> > never terminates.
> 
> Under this situation:
> 
> IMO, if this request has been handled by driver's irq handler, and if
> driver's .timeout still returns BLK_EH_RESET_TIMER, it is driver's bug,
> and the correct return value should be BLK_EH_HANDLED.

We have plenty drivers that do that, so we'll need to audit all the
drivers first.  I guess a start would be to find a way that disables
timeouts entirely.

  parent reply	other threads:[~2018-04-12 13:21 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10 21:01 [PATCH v5] blk-mq: Avoid that a completion can be ignored for BLK_EH_RESET_TIMER Bart Van Assche
2018-04-11  2:11 ` Ming Lei
2018-04-11 13:10   ` Sagi Grimberg
2018-04-11 13:36   ` Bart Van Assche
2018-04-11 13:36     ` Bart Van Assche
2018-04-12 13:21   ` Christoph Hellwig [this message]
2018-04-11 13:19 ` Sagi Grimberg
2018-04-11 13:34   ` Bart Van Assche
2018-04-11 13:34     ` Bart Van Assche
2018-04-11 14:32     ` Sagi Grimberg
2018-04-11 14:34       ` Bart Van Assche
2018-04-11 14:34         ` Bart Van Assche
2018-04-12  5:32   ` Christoph Hellwig
2018-04-12 13:23 ` Christoph Hellwig
2018-04-14  0:06 ` Ming Lei

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180412132137.GB5476@lst.de \
    --to=hch@lst.de \
    --cc=axboe@kernel.dk \
    --cc=bart.vanassche@wdc.com \
    --cc=israelr@mellanox.com \
    --cc=linux-block@vger.kernel.org \
    --cc=maxg@mellanox.com \
    --cc=ming.lei@redhat.com \
    --cc=sagi@grimberg.me \
    --cc=stable@vger.kernel.org \
    --cc=tj@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.