From: Linus Torvalds <torvalds@linux-foundation.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>,
Johannes Berg <johannes@sipsolutions.net>,
Oliver Giles <ohw.giles@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: Splicing to/from a tty
Date: Wed, 20 Jan 2021 15:40:29 -0800 [thread overview]
Message-ID: <CAHk-=widQ+oLHbm=wSrewpLgXJg_FWCZV3BERmaEAx+ZCMfmZg@mail.gmail.com> (raw)
In-Reply-To: <20210120231439.GE740243@zeniv-ca>
On Wed, Jan 20, 2021 at 3:14 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> Umm... Why do we clear FMODE_PWRITE there [seq_open - ed], anyway?
I think it's pointless and historical, and comes from "several /proc
files supported the simple single-write model, nothing ever supported
moving around and writing".
The seq_file stuff was always about reading, and then the writing part
was generally random special-case hacks on the side.
So I think that "clear PWRITE" thing is to make sure we get sane error
cases if somebody tries something funny, knowing that none of the
hacky stuff support it.
And then the very special kernfs thing adds it back in, because it
does in fact allow seeking writes.
Linus
next prev parent reply other threads:[~2021-01-21 6:44 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-16 7:35 Splicing to/from a tty Oliver Giles
2021-01-16 16:46 ` Johannes Berg
2021-01-17 6:12 ` Oliver Giles
2021-01-18 8:53 ` Christoph Hellwig
2021-01-18 8:58 ` Johannes Berg
2021-01-18 19:26 ` Linus Torvalds
2021-01-18 19:45 ` Al Viro
2021-01-18 19:49 ` Linus Torvalds
2021-01-18 19:56 ` Al Viro
2021-01-24 19:11 ` Linus Torvalds
2021-01-25 9:16 ` [PATCH] fs/pipe: allow sendfile() to pipe again Johannes Berg
2021-01-25 10:16 ` Christoph Hellwig
2021-01-25 20:34 ` Linus Torvalds
2021-01-26 6:07 ` Splicing to/from a tty Al Viro
2021-01-26 6:08 ` [PATCH 1/3] do_splice_to(): move the logics for limiting the read length in Al Viro
2021-01-26 6:09 ` [PATCH 2/3] take the guts of file-to-pipe splice into a helper function Al Viro
2021-01-26 6:09 ` [PATCH 3/3] teach sendfile(2) to handle send-to-pipe directly Al Viro
2021-01-26 18:57 ` Linus Torvalds
2021-01-26 19:33 ` Al Viro
2021-01-26 18:49 ` Splicing to/from a tty Linus Torvalds
2021-01-26 19:42 ` Al Viro
2021-01-18 19:34 ` Al Viro
2021-01-18 19:46 ` Linus Torvalds
2021-01-18 19:54 ` Al Viro
2021-01-20 16:26 ` Al Viro
2021-01-20 19:11 ` Al Viro
2021-01-20 19:27 ` Linus Torvalds
2021-01-20 22:25 ` David Laight
2021-01-20 23:02 ` Al Viro
2021-01-20 23:14 ` Al Viro
2021-01-20 23:40 ` Linus Torvalds [this message]
2021-01-21 0:38 ` Al Viro
2021-01-21 1:04 ` Linus Torvalds
2021-01-21 1:45 ` Al Viro
2021-01-21 3:38 ` Linus Torvalds
2021-01-21 6:05 ` Willy Tarreau
2021-01-21 8:04 ` Johannes Berg
2021-01-21 10:08 ` David Laight
2021-01-18 8:16 ` Christoph Hellwig
2021-01-18 19:36 ` Linus Torvalds
2021-01-18 20:24 ` Linus Torvalds
2021-01-18 21:35 ` Linus Torvalds
2021-01-18 21:54 ` Linus Torvalds
2021-01-18 22:03 ` Linus Torvalds
2021-01-18 22:20 ` Linus Torvalds
2021-01-19 1:38 ` Linus Torvalds
2021-01-19 11:53 ` Greg Kroah-Hartman
2021-01-19 16:56 ` Robert Karszniewicz
2021-01-19 17:10 ` Robert Karszniewicz
2021-01-19 22:09 ` Oliver Giles
2021-01-19 17:25 ` Linus Torvalds
2021-01-19 20:24 ` Linus Torvalds
2021-01-19 20:38 ` Christoph Hellwig
2021-01-20 1:25 ` Oliver Giles
2021-01-20 4:44 ` Linus Torvalds
2021-01-20 8:15 ` Oliver Giles
2021-01-21 1:18 ` tty splice branch (was "Re: Splicing to/from a tty") Linus Torvalds
2021-01-21 8:44 ` Greg Kroah-Hartman
2021-01-21 8:50 ` Jiri Slaby
2021-01-21 8:58 ` Jiri Slaby
2021-01-21 17:52 ` Linus Torvalds
2021-01-21 8:58 ` Greg Kroah-Hartman
2021-01-21 17:03 ` Splicing to/from a tty Robert Karszniewicz
2021-01-21 18:43 ` Linus Torvalds
2021-01-19 11:52 ` Greg Kroah-Hartman
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='CAHk-=widQ+oLHbm=wSrewpLgXJg_FWCZV3BERmaEAx+ZCMfmZg@mail.gmail.com' \
--to=torvalds@linux-foundation.org \
--cc=gregkh@linuxfoundation.org \
--cc=hch@lst.de \
--cc=johannes@sipsolutions.net \
--cc=linux-kernel@vger.kernel.org \
--cc=ohw.giles@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.