From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030484AbWF1ImR (ORCPT ); Wed, 28 Jun 2006 04:42:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030486AbWF1ImR (ORCPT ); Wed, 28 Jun 2006 04:42:17 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:60390 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1030484AbWF1ImQ (ORCPT ); Wed, 28 Jun 2006 04:42:16 -0400 Subject: Re: [PATCH 00/20] Mount writer count and read-only bind mounts (v3) From: Arjan van de Ven To: Andrew Morton Cc: Dave Hansen , linux-kernel@vger.kernel.org, herbert@13thfloor.at, viro@ftp.linux.org.uk, serue@us.ibm.com In-Reply-To: <20060627191727.406b0e18.akpm@osdl.org> References: <20060627221436.77CCB048@localhost.localdomain> <20060627183822.667d9d49.akpm@osdl.org> <1151459436.24103.70.camel@localhost.localdomain> <20060627191727.406b0e18.akpm@osdl.org> Content-Type: text/plain Date: Wed, 28 Jun 2006 10:42:07 +0200 Message-Id: <1151484127.3153.8.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2006-06-27 at 19:17 -0700, Andrew Morton wrote: > On Tue, 27 Jun 2006 18:50:36 -0700 > Dave Hansen wrote: > > > > > Since the last revision, the locking in faccessat() and > > > > mnt_is_readonly() has been changed to fix a race which might have > > > > caused a false-negative mount-is-readonly return when faccessat() > > > > is called while another two processes are racing to make a mount > > > > readonly. > > > > > > > umm, what's it all for? > > > > Mostly for vserver, for now. They allow a filesystem to be r/w, but > > have r/o views into it. This is really handy so that every vserver can > > use a common install but still allow the administrator to update it. > > OK. That makes it one of those features which stays in -mm until we work > out what we're going to do about containers/vserver/etc. > > Unless there's something else which needs it? in a previous life we repeatedly had customers who really wanted this. It's more than just containers; it's chroots too (arguably that's containers as well but a lot more common deployed today) but also things where the customer wanted to mount a part of a network mount as /usr, but read only just to be sure....