public inbox for linux-block@vger.kernel.org
 help / color / mirror / Atom feed
From: Jens Axboe <axboe@kernel.dk>
To: Damien Le Moal <Damien.LeMoal@wdc.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	xfs <linux-xfs@vger.kernel.org>
Subject: Re: Block device direct read EIO handling broken?
Date: Mon, 5 Aug 2019 14:28:48 -0700	[thread overview]
Message-ID: <f3f98663-8f92-c933-c7c0-8db6635e6112@kernel.dk> (raw)
In-Reply-To: <BYAPR04MB5816C3B24310C1E18F9E024CE7DA0@BYAPR04MB5816.namprd04.prod.outlook.com>

On 8/5/19 2:27 PM, Damien Le Moal wrote:
> On 2019/08/06 6:26, Jens Axboe wrote:
>>> In any case, looking again at this code, it looks like there is a
>>> problem with dio->size being incremented early, even for fragments
>>> that get BLK_QC_T_EAGAIN, because dio->size is being used in
>>> blkdev_bio_end_io(). So an incorrect size can be reported to user
>>> space in that case on completion (e.g. large asynchronous no-wait dio
>>> that cannot be issued in one go).
>>>
>>> So maybe something like this ? (completely untested)
>>
>> I think that looks pretty good, I like not double accounting with
>> this_size and dio->size, and we retain the old style ordering for the
>> ret value.
> 
> Do you want a proper patch with real testing backup ? I can send that
> later today.

Yeah that'd be great, I like your approach better.

-- 
Jens Axboe


  reply	other threads:[~2019-08-05 21:28 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-05 18:15 Block device direct read EIO handling broken? Darrick J. Wong
2019-08-05 18:31 ` Jens Axboe
2019-08-05 20:31   ` Jens Axboe
2019-08-05 20:54     ` Jens Axboe
2019-08-05 21:08     ` Damien Le Moal
2019-08-05 21:25       ` Jens Axboe
2019-08-05 21:27         ` Damien Le Moal
2019-08-05 21:28           ` Jens Axboe [this message]
2019-08-05 21:59             ` Damien Le Moal
2019-08-05 22:05               ` Damien Le Moal
2019-08-06  0:05                 ` Damien Le Moal
2019-08-06  0:23                   ` Dave Chinner
2019-08-06 11:32                     ` Damien Le Moal
2019-08-06  4:09                   ` Jens Axboe
2019-08-06  7:05                     ` Damien Le Moal
2019-08-06 13:34                       ` Jens Axboe
2019-08-07  9:42                         ` Damien Le Moal
2019-08-06 13:23                     ` Damien Le Moal

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=f3f98663-8f92-c933-c7c0-8db6635e6112@kernel.dk \
    --to=axboe@kernel.dk \
    --cc=Damien.LeMoal@wdc.com \
    --cc=darrick.wong@oracle.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox