From: Florian Weimer <fweimer@redhat•com>
To: Christian Brauner <christian@brauner•io>
Cc: linux-ia64@vger•kernel.org, linux-sh@vger•kernel.org,
linux-kernel@vger•kernel.org, dhowells@redhat•com,
linux-kselftest@vger•kernel.org, sparclinux@vger•kernel.org,
shuah@kernel•org, linux-arch@vger•kernel.org,
linux-s390@vger•kernel.org, miklos@szeredi•hu, x86@kernel•org,
torvalds@linux-foundation•org, linux-mips@vger•kernel.org,
linux-xtensa@linux-xtensa•org, tkjos@android•com, arnd@arndb•de,
jannh@google•com, linux-m68k@lists•linux-m68k.org,
viro@zeniv•linux.org.uk, tglx@linutronix•de, ldv@altlinux•org,
linux-arm-kernel@lists•infradead.org,
linux-parisc@vger•kernel.org, linux-api@vger•kernel.org,
oleg@redhat•com, linux-alpha@vger•kernel.org,
linux-fsdevel@vger•kernel.org, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 1/2] open: add close_range()
Date: Tue, 21 May 2019 15:10:11 +0200 [thread overview]
Message-ID: <87h89o9cng.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <20190521130438.q3u4wvve7p6md6cm@brauner.io> (Christian Brauner's message of "Tue, 21 May 2019 15:04:39 +0200")
* Christian Brauner:
>> Solaris has an fdwalk function:
>>
>> <https://docs.oracle.com/cd/E88353_01/html/E37843/closefrom-3c.html>
>>
>> So a different way to implement this would expose a nextfd system call
>
> Meh. If nextfd() then I would like it to be able to:
> - get the nextfd(fd) >= fd
> - get highest open fd e.g. nextfd(-1)
The highest open descriptor isn't istering for fdwalk because nextfd
would just fail.
> But then I wonder if nextfd() needs to be a syscall and isn't just
> either:
> fcntl(fd, F_GET_NEXT)?
> or
> prctl(PR_GET_NEXT)?
I think the fcntl route is a bit iffy because you might need it to get
the *first* valid descriptor.
>> to userspace, so that we can use that to implement both fdwalk and
>> closefrom. But maybe fdwalk is just too obscure, given the existence of
>> /proc.
>
> Yeah we probably don't need fdwalk.
Agreed. Just wanted to bring it up for completeness. I certainly don't
want to derail the implementation of close_range.
Thanks,
Florian
next prev parent reply other threads:[~2019-05-21 13:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-21 11:34 [PATCH 1/2] open: add close_range() Christian Brauner
2019-05-21 11:34 ` [PATCH 2/2] tests: add close_range() tests Christian Brauner
2019-05-21 12:09 ` [PATCH 1/2] open: add close_range() Florian Weimer
2019-05-21 13:04 ` Christian Brauner
2019-05-21 13:10 ` Florian Weimer [this message]
2019-05-21 13:18 ` Christian Brauner
2019-05-21 13:23 ` Christian Brauner
2019-05-21 15:00 ` Al Viro
2019-05-21 16:30 ` David Howells
2019-05-21 16:41 ` Christian Brauner
2019-05-21 20:23 ` Linus Torvalds
2019-05-22 8:12 ` Christian Brauner
2019-05-21 19:20 ` Al Viro
2019-05-21 19:59 ` Matthew Wilcox
2019-05-21 16:53 ` Christian Brauner
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=87h89o9cng.fsf@oldenburg2.str.redhat.com \
--to=fweimer@redhat$(echo .)com \
--cc=arnd@arndb$(echo .)de \
--cc=christian@brauner$(echo .)io \
--cc=dhowells@redhat$(echo .)com \
--cc=jannh@google$(echo .)com \
--cc=ldv@altlinux$(echo .)org \
--cc=linux-alpha@vger$(echo .)kernel.org \
--cc=linux-api@vger$(echo .)kernel.org \
--cc=linux-arch@vger$(echo .)kernel.org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-fsdevel@vger$(echo .)kernel.org \
--cc=linux-ia64@vger$(echo .)kernel.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-kselftest@vger$(echo .)kernel.org \
--cc=linux-m68k@lists$(echo .)linux-m68k.org \
--cc=linux-mips@vger$(echo .)kernel.org \
--cc=linux-parisc@vger$(echo .)kernel.org \
--cc=linux-s390@vger$(echo .)kernel.org \
--cc=linux-sh@vger$(echo .)kernel.org \
--cc=linux-xtensa@linux-xtensa$(echo .)org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=miklos@szeredi$(echo .)hu \
--cc=oleg@redhat$(echo .)com \
--cc=shuah@kernel$(echo .)org \
--cc=sparclinux@vger$(echo .)kernel.org \
--cc=tglx@linutronix$(echo .)de \
--cc=tkjos@android$(echo .)com \
--cc=torvalds@linux-foundation$(echo .)org \
--cc=viro@zeniv$(echo .)linux.org.uk \
--cc=x86@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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