From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denys Vlasenko Subject: Re: [PATCH] Make /proc/net a symlink on /proc/self/net Date: Sun, 23 Mar 2008 14:00:41 +0100 Message-ID: <200803231400.41397.vda.linux@googlemail.com> References: <47CE8FF7.7000701@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Andrew Morton , David Miller , Linux Netdev List , Linux Kernel Mailing List , "Eric W. Biederman" , Alexey Dobriyan To: Pavel Emelyanov Return-path: Received: from fg-out-1718.google.com ([72.14.220.155]:38210 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755883AbYCWNCJ (ORCPT ); Sun, 23 Mar 2008 09:02:09 -0400 Received: by fg-out-1718.google.com with SMTP id l27so2438695fgb.17 for ; Sun, 23 Mar 2008 06:02:08 -0700 (PDT) In-Reply-To: <47CE8FF7.7000701@openvz.org> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Wednesday 05 March 2008 13:20, Pavel Emelyanov wrote: > Current /proc/net is done with so called "shadows", but current > implementation is broken and has little chances to get fixed. > > The problem is that dentries subtree of /proc/net directory has > fancy revalidation rules to make processes living in different > net namespaces see different entries in /proc/net subtree, but > currently, tasks see in the /proc/net subdir the contents of any > other namespace, depending on who opened the file first. > > The proposed fix is to turn /proc/net into a symlink, which points > to /proc/self/net, which in turn shows what previously was in > /proc/net - the network-related info, from the net namespace the > appropriate task lives in. > > # ls -l /proc/net > lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net This broke tools which read /proc/net/dev. Under non-root, they are no longer working. This is a regression. -- vda