linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Miklos Szeredi <miklos@szeredi.hu>
To: Josh Triplett <josh@joshtriplett.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>,
	io-uring@vger.kernel.org,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Arnd Bergmann <arnd@arndb.de>, Jens Axboe <axboe@kernel.dk>,
	Aleksa Sarai <cyphar@cyphar.com>,
	linux-man <linux-man@vger.kernel.org>,
	Linux API <linux-api@vger.kernel.org>
Subject: Re: [PATCH v5 2/3] fs: openat2: Extend open_how to allow userspace-selected fds
Date: Thu, 23 Apr 2020 09:45:45 +0200	[thread overview]
Message-ID: <CAJfpegtXj4bSbhpx+=z=R0_ZT8uPEJAAev0O+DVg3AX242e=-g@mail.gmail.com> (raw)
In-Reply-To: <20200423073310.GA169998@localhost>

On Thu, Apr 23, 2020 at 9:33 AM Josh Triplett <josh@joshtriplett.org> wrote:

> > What are the plans for those syscalls that don't easily lend
> > themselves to this modification (such as accept(2))?
>
> accept4 has a flags argument with more flags available, so it'd be
> entirely possible to cleanly extend it further without introducing a new
> version.

Variable argument syscalls, you are thinking?

> > I mean, you could open the file descriptor outside of io_uring in such
> > cases, no?
>
> I would prefer to not introduce that limitation in the first place, and
> instead open normal file descriptors.
>
> > The point of O_SPECIFIC_FD is to be able to perform short
> > sequences of open/dosomething/close without having to block and having
> > to issue separate syscalls.
>
> "close" is not a required component. It's entirely possible to use
> io_uring to open a file descriptor, do various things with it, and then
> leave it open for subsequent usage via either other io_uring chains or
> standalone syscalls.

If this use case arraises, we could add an op to dup/move a private
descriptor to a public one.  io_uring can return values, right?

Still not convinced...

Thanks,
Miklos

  reply	other threads:[~2020-04-23  7:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-22  5:19 [PATCH v5 0/3] Support userspace-selected fds Josh Triplett
2020-04-22  5:19 ` [PATCH v5 1/3] fs: Support setting a minimum fd for "lowest available fd" allocation Josh Triplett
2020-04-22  6:06   ` Michael Kerrisk (man-pages)
2020-04-23  1:12   ` Dmitry V. Levin
2020-04-23  4:51     ` Josh Triplett
2020-04-23  9:24   ` Arnd Bergmann
2020-04-22  5:20 ` [PATCH v5 2/3] fs: openat2: Extend open_how to allow userspace-selected fds Josh Triplett
2020-04-22  6:06   ` Michael Kerrisk (man-pages)
2020-04-22  7:55     ` Miklos Szeredi
2020-04-23  0:48       ` Josh Triplett
2020-04-23  4:24         ` Miklos Szeredi
2020-04-23  4:42           ` Josh Triplett
2020-04-23  6:04             ` Miklos Szeredi
2020-04-23  7:33               ` Josh Triplett
2020-04-23  7:45                 ` Miklos Szeredi [this message]
2020-04-23  7:57                   ` Miklos Szeredi
2020-04-23  9:20                     ` Miklos Szeredi
2020-04-23  9:46                       ` Miklos Szeredi
2020-04-23  8:06                   ` Josh Triplett
2020-04-22  5:20 ` [PATCH v5 3/3] fs: pipe2: Support O_SPECIFIC_FD Josh Triplett
2020-04-22  6:06   ` Michael Kerrisk (man-pages)
2020-04-22 15:44   ` Florian Weimer
2020-04-23  0:44     ` Josh Triplett
2020-04-22  6:05 ` [PATCH v5 0/3] Support userspace-selected fds Michael Kerrisk (man-pages)

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='CAJfpegtXj4bSbhpx+=z=R0_ZT8uPEJAAev0O+DVg3AX242e=-g@mail.gmail.com' \
    --to=miklos@szeredi.hu \
    --cc=arnd@arndb.de \
    --cc=axboe@kernel.dk \
    --cc=cyphar@cyphar.com \
    --cc=io-uring@vger.kernel.org \
    --cc=josh@joshtriplett.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-man@vger.kernel.org \
    --cc=mtk.manpages@gmail.com \
    --cc=viro@zeniv.linux.org.uk \
    /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;
as well as URLs for NNTP newsgroup(s).