public inbox for [email protected]
 help / color / mirror / Atom feed
From: Josh Triplett <[email protected]>
To: Jens Axboe <[email protected]>
Cc: [email protected], [email protected]
Subject: Re: [PATCHSET v2 0/6] Support selectable file descriptors
Date: Wed, 4 Mar 2020 11:03:41 -0800	[thread overview]
Message-ID: <20200304190341.GB16251@localhost> (raw)
In-Reply-To: <[email protected]>

On Wed, Mar 04, 2020 at 11:00:10AM -0700, Jens Axboe wrote:
> One of the fabled features with chains has long been the desire to
> support things like:
> 
> <open fileX><read from fileX><close fileX>
> 
> in a single chain. This currently doesn't work, since the read/close
> depends on what file descriptor we get on open.
> 
> The original attempt at solving this provided a means to pass
> descriptors between chains in a link, this version takes a different
> route. Based on Josh's support for O_SPECIFIC_FD, we can instead control
> what fd value we're going to get out of open (or accept). With that in
> place, we don't need to do any magic to make this work. The above chain
> then becomes:
> 
> <open fileX with fd Y><read from fd Y><close fd Y>
> 
> which is a lot more useful, and allows any sort of weird chains without
> needing to nest "last open" file descriptors.
> 
> Updated the test program to use this approach:
> 
> https://git.kernel.dk/cgit/liburing/plain/test/orc.c?h=fd-select
> 
> which forces the use of fd==89 for the open, and then uses that for the
> read and close.
> 
> Outside of this adaptation, fixed a few bugs and cleaned things up.

I posted one comment about an issue in patch 6.

Patches 2-5 look great; for those:
Reviewed-by: Josh Triplett <[email protected]>

Thanks for picking this up and running with it!

  parent reply	other threads:[~2020-03-04 19:03 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-04 18:00 [PATCHSET v2 0/6] Support selectable file descriptors Jens Axboe
2020-03-04 18:00 ` [PATCH 1/6] fs: openat2: Extend open_how to allow userspace-selected fds Jens Axboe
2020-03-04 18:00 ` [PATCH 2/6] io_uring: move CLOSE req->file checking into handler Jens Axboe
2020-03-04 18:00 ` [PATCH 3/6] io_uring: move read/write side file based prep into op handler Jens Axboe
2020-03-04 18:00 ` [PATCH 4/6] io_uring: support deferred retrival of file from fd Jens Axboe
2020-03-04 18:00 ` [PATCH 5/6] net: allow specific fd selection for __sys_accept4_file() Jens Axboe
2020-03-04 18:00 ` [PATCH 6/6] io_uring: allow specific fd for IORING_OP_ACCEPT Jens Axboe
2020-03-04 19:02   ` Josh Triplett
2020-03-04 19:09     ` Jens Axboe
2020-03-04 19:51       ` Josh Triplett
2020-03-04 19:03 ` Josh Triplett [this message]
2020-03-04 19:10   ` [PATCHSET v2 0/6] Support selectable file descriptors Jens Axboe
2020-03-04 19:28     ` Jeff Layton
2020-03-04 19:50       ` Jens Axboe
2020-03-04 19:56     ` Josh Triplett
2020-03-04 20:00       ` Jens Axboe
2020-03-04 20:09         ` Josh Triplett
2020-03-04 20:14           ` Jens Axboe
2020-03-09 20:33 ` Stefan Metzmacher

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=20200304190341.GB16251@localhost \
    [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