public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Josef <[email protected]>, [email protected]
Cc: [email protected]
Subject: Re: io_uring file descriptor address already in use error
Date: Tue, 25 Aug 2020 09:12:17 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAAss7+o=0zd9JQj+B0Fe1cONCtMJdKkfQuT+Hzx9X9jRigrfZQ@mail.gmail.com>

On 8/25/20 9:00 AM, Josef wrote:
> Hi,
> 
> I found a bug submitting a server socket poll in io_uring. The file
> descriptor is not really closed when calling close(2), if I bind a new
> socket with the same address & port I'll get an "Already in use" error
> message
> 
> example to reproduce it
> https://gist.github.com/1Jo1/3ace601884b86f7495fd5241190494dc

Not sure this is an actual bug, but depends on how you look at it. Your
poll command has a reference to the file, which means that when you close
it here:

    assert(close(sock_listen_fd1) == 0); 

then that's not the final close. If you move the io_uring_queue_exit()
before that last create_server_socket() it should work, since the poll
will have been canceled (and hence the file closed) at that point.

That said, I don't believe we actually need the file after arming the
poll, so we could potentially close it once we've armed it. That would
make your example work.

-- 
Jens Axboe


  reply	other threads:[~2020-08-25 15:12 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-25 15:00 io_uring file descriptor address already in use error Josef
2020-08-25 15:12 ` Jens Axboe [this message]
2020-08-25 15:17   ` Jens Axboe
2020-08-25 15:48     ` Jens Axboe
2020-08-25 16:38       ` Josef
2020-08-25 16:47         ` Jens Axboe
2020-08-26  3:01           ` Josef
2020-08-26 13:44             ` Jens Axboe
2020-08-26 18:25               ` Josef
2020-08-26 18:39                 ` 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