From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Jones <davej@redhat.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: VFS deadlock ?
Date: Fri, 22 Mar 2013 00:20:31 +0000 [thread overview]
Message-ID: <20130322002030.GI21522@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20130322001257.GH21522@ZenIV.linux.org.uk>
On Fri, Mar 22, 2013 at 12:12:57AM +0000, Al Viro wrote:
> See the posting upthread. We could try to kludge around that as well
> (e.g. have d_ancestor() compare ->d_inode instead of dentries themselves),
> but I really think it's a lousy idea only inviting further abuse.
>
> What we should do, IMO, is to turn /proc/<pid>/net into a honest symlink -
> to ../nets/<netns ID>/net. Hell, might even make it a magical symlink
> instead...
BTW, the root cause is that what used to be /proc/net became per-process.
So Eric (IIRC) had added /proc/<pid>/net. Only they are not really per-process
- they are per-netns. And instead of putting those per-ns trees elsewhere and
having /proc/<pid>/net resolve to the right one, we got them as directories,
with each entry hardlinked between all /proc/<pid>/net for processes from
the same netns. Including the subdirectory ones. Oops...
Another variant is to keep cross-hardlinks for non-directories and duplicate
directory dentries/inodes as we do for /proc/<pid>/net themselves.
next prev parent reply other threads:[~2013-03-22 0:20 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 19:06 Dave Jones
2013-03-21 19:21 ` Al Viro
2013-03-21 20:31 ` Dave Jones
2013-03-21 19:29 ` Al Viro
2013-03-21 20:15 ` Linus Torvalds
2013-03-21 20:26 ` Dave Jones
2013-03-21 20:32 ` Linus Torvalds
2013-03-21 20:36 ` Dave Jones
2013-03-21 20:47 ` Al Viro
2013-03-21 21:02 ` Dave Jones
2013-03-21 21:18 ` Linus Torvalds
2013-03-21 21:26 ` Al Viro
2013-03-21 21:41 ` Dave Jones
2013-03-21 21:47 ` Linus Torvalds
2013-03-21 21:55 ` Al Viro
2013-03-21 21:57 ` Linus Torvalds
2013-03-21 22:03 ` Al Viro
2013-03-21 21:52 ` Al Viro
2013-03-21 22:12 ` Dave Jones
2013-03-21 22:29 ` Dave Jones
2013-03-21 22:53 ` Linus Torvalds
2013-03-21 23:07 ` Dave Jones
2013-03-21 23:36 ` Al Viro
2013-03-21 23:58 ` Linus Torvalds
2013-03-22 0:01 ` Linus Torvalds
2013-03-22 0:12 ` Al Viro
2013-03-22 0:20 ` Al Viro [this message]
2013-03-22 0:22 ` Linus Torvalds
2013-03-22 1:22 ` Al Viro
2013-03-22 1:33 ` Linus Torvalds
2013-03-22 1:40 ` Al Viro
2013-03-22 4:37 ` [CFT] " Al Viro
2013-03-22 4:55 ` Linus Torvalds
2013-03-22 5:18 ` Al Viro
2013-03-22 5:33 ` Linus Torvalds
2013-03-22 6:09 ` Al Viro
2013-03-22 6:22 ` Al Viro
2013-03-22 16:23 ` Dave Jones
2013-03-22 19:43 ` Linus Torvalds
2013-03-22 21:28 ` Al Viro
2013-03-22 22:57 ` Eric W. Biederman
2013-03-22 5:19 ` Linus Torvalds
2013-03-22 0:08 ` Al Viro
2013-03-22 0:15 ` Linus Torvalds
2013-03-22 0:19 ` Linus Torvalds
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