From: Florian Weimer <fweimer@redhat.com>
To: Christian Brauner <christian@brauner.io>
Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
jannh@google.com, oleg@redhat.com, tglx@linutronix.de,
torvalds@linux-foundation.org, arnd@arndb.de, shuah@kernel.org,
dhowells@redhat.com, tkjos@android.com, ldv@altlinux.org,
miklos@szeredi.hu, linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org,
linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
x86@kernel.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 13:10 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 16:53 ` Christian Brauner
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
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