public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>,
	[email protected], Josef Grieb <[email protected]>
Subject: Re: [PATCH 5.11] io_uring: NULL files dereference by SQPOLL
Date: Sat, 7 Nov 2020 15:28:43 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 11/7/20 2:54 PM, Pavel Begunkov wrote:
> On 07/11/2020 21:18, Pavel Begunkov wrote:
>> On 07/11/2020 21:16, Pavel Begunkov wrote:
>>> SQPOLL task may find sqo_task->files == NULL, so
>>> __io_sq_thread_acquire_files() would left it unset and so all the
>>> following fails, e.g. attempts to submit. Fail if sqo_task doesn't have
>>> files.
>>
>> Josef, could you try this one?
> 
> Hmm, as you said it happens often... IIUC there is a drawback with
> SQPOLL -- after the creator process/thread exits most of subsequent
> requests will start failing.
> I'd say from application correctness POV such tasks should exit
> only after their SQPOLL io_urings got killed.

I don't think there's anything wrong with that - if you submit requests
and exit before they have completed, then you by definition are not
caring about the result of them.

-- 
Jens Axboe


  reply	other threads:[~2020-11-07 22:28 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-07 21:16 [PATCH 5.11] io_uring: NULL files dereference by SQPOLL Pavel Begunkov
2020-11-07 21:18 ` Pavel Begunkov
2020-11-07 21:54   ` Pavel Begunkov
2020-11-07 22:28     ` Jens Axboe [this message]
2020-11-07 22:47       ` Pavel Begunkov
2020-11-07 23:18         ` Jens Axboe
2020-11-08  2:09           ` Josef
2020-11-08  6:50             ` Josef
2020-11-08 11:39               ` Pavel Begunkov
2020-11-08 11:31             ` Pavel Begunkov
2020-11-08 11:24           ` Pavel Begunkov
2020-11-07 22:30 ` Jens Axboe
2020-11-07 22:49   ` Pavel Begunkov
2020-11-07 23:17     ` Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2020-11-08 12:55 Pavel Begunkov
2020-11-09 14:21 ` Jens Axboe

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 \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /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