From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christian Brauner <brauner@kernel.org>,
linux-fsdevel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Jann Horn <jannh@google.com>
Subject: Re: [PATCH RFC 0/4] fs: port files to rcuref_long_t
Date: Sat, 5 Oct 2024 23:51:52 +0100 [thread overview]
Message-ID: <20241005225152.GC4017910@ZenIV> (raw)
In-Reply-To: <CAHk-=wgKmjuc8T_9mc7hWpBp1m_E+wkri-jFAD67AqkHZQjWPQ@mail.gmail.com>
On Sat, Oct 05, 2024 at 03:43:16PM -0700, Linus Torvalds wrote:
> Come on - the only possible reason for two billion files is a bad
> user. Do we care what error return an attacker gets? No. We're not
> talking about breaking existing programs.
Umm... It can be a bad failure mode of a buggy program, really
unpleasant to debug if the pile of references kept growing on stdin
of that sucker, which just happens to be controlling tty of your
login session; fork(2) starting to fail for everything that has it
opened is not fun.
That's really nit-picking though, since
> So I don't think that's actually the important thing here. If we keep
> it a 'long', I won't lose any sleep over it.
... exactly.
> But using the rcuref code doesn't work (regardless of whether 32-bit
> or 'long' ref), because of the memory ordering issues.
*nod*
next prev parent reply other threads:[~2024-10-05 22:51 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-05 19:16 [PATCH RFC 0/4] fs: port files to rcuref_long_t Christian Brauner
2024-10-05 19:16 ` [PATCH RFC 1/4] fs: protect backing files with rcu Christian Brauner
2024-10-05 19:16 ` [PATCH RFC 2/4] types: add rcuref_long_t Christian Brauner
2024-10-05 19:16 ` [PATCH RFC 3/4] rcuref: add rcuref_long_*() helpers Christian Brauner
2024-10-05 19:16 ` [PATCH RFC 4/4] fs: port files to rcuref_long_t Christian Brauner
2024-10-05 21:42 ` [PATCH RFC 0/4] " Linus Torvalds
2024-10-05 22:01 ` Al Viro
2024-10-05 22:14 ` Linus Torvalds
2024-10-05 22:28 ` Al Viro
2024-10-05 22:43 ` Linus Torvalds
2024-10-05 22:51 ` Al Viro [this message]
2024-10-06 9:55 ` Christian Brauner
2024-10-05 22:01 ` Linus Torvalds
2024-10-06 10:21 ` Christian Brauner
2024-10-06 18:09 ` Linus Torvalds
2024-10-07 7:37 ` Christian Brauner
2024-10-06 9:48 ` Christian Brauner
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