From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030515AbWBIDOp (ORCPT ); Wed, 8 Feb 2006 22:14:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030528AbWBIDOp (ORCPT ); Wed, 8 Feb 2006 22:14:45 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:22948 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1030515AbWBIDOo (ORCPT ); Wed, 8 Feb 2006 22:14:44 -0500 To: Al Viro Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 8/8] fix handling of st_nlink on procfs root References: <20060209021749.GM27946@ftp.linux.org.uk> From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 08 Feb 2006 20:14:03 -0700 In-Reply-To: <20060209021749.GM27946@ftp.linux.org.uk> (Al Viro's message of "Thu, 9 Feb 2006 02:17:49 +0000") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Al Viro writes: > On Wed, Feb 08, 2006 at 06:04:36PM -0700, Eric W. Biederman wrote: >> There are some other similar problems still in /proc. >> >> In my pid namespace work I have some managed to clean most of >> this up, and finally split proc into two filesystems. >> >> The only was I was able to get the union to work was >> to let lookup return files in an internal mount. >> >> The only problem was that /proc/irq/.. != /proc/ > > That's not the only problem here, unfortunately. Well at the moment it seems to be. Basically a case of everything seems to work but the semantics are weird and ugly, and not worth doing if the legacy semantics are not maintained. >> I will finish all of this up shortly but do you know a good >> way to do a union mount when we mount proc? > > Not transparently; mount(2) should _not_ mount two filesystems at once. > Note that you'll run into serious problems as soon as you try to mount/umount/ > mount --move the stuff there. And doing unionfs approach will cause > fsckloads of fun issues with lifetimes. :) Do you know if there is anything in what autofs does for mounts that could be reused. To a certain extent it would work find if I had a mount point and all of the legacy directories were symlinks to it. Anyway there are lots of possibilities and I will work something out before it makes into the stable kernel. I keep having the feeling that I might just wind up with everything making sense under proc as I create more namespaces :) Eric