From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262267AbVG2Ari (ORCPT ); Thu, 28 Jul 2005 20:47:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262256AbVG2Arc (ORCPT ); Thu, 28 Jul 2005 20:47:32 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:30713 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S262255AbVG2ArV (ORCPT ); Thu, 28 Jul 2005 20:47:21 -0400 Message-ID: <42E97C7D.9040804@mvista.com> Date: Thu, 28 Jul 2005 17:46:53 -0700 From: Mark Bellon User-Agent: Mozilla Thunderbird 1.0.6-1.1.fc3 (X11/20050720) X-Accept-Language: en-us, en MIME-Version: 1.0 CC: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] disk quotas fail when /etc/mtab is symlinked to /proc/mounts References: <42E97236.6080404@mvista.com> <20050728172302.1b04511a.akpm@osdl.org> <42E9787D.2020700@mvista.com> In-Reply-To: <42E9787D.2020700@mvista.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mark Bellon wrote: > Andrew Morton wrote: > >> Mark Bellon wrote: >> >> >>> If /etc/mtab is a regular file all of the mount options (of a file >>> system) are written to /etc/mtab by the mount command. The quota >>> tools look there for the quota strings for their operation. If, >>> however, /etc/mtab is a symlink to /proc/mounts (a "good thing" in >>> some environments) the tools don't write anything - they assume the >>> kernel will take care of things. >>> >>> While the quota options are sent down to the kernel via the mount >>> system call and the file system codes handle them properly >>> unfortunately there is no code to echo the quota strings into >>> /proc/mounts and the quota tools fail in the symlink case. >>> >> >> >> hm. Perhaps others with operational experience in that area can >> comment. >> >> > OK. > >> >> >>> The attached patchs modify the EXT[2|3] and [X|J]FS codes to add the >>> necessary hooks. The show_options function of each file system in >>> these patches currently deal with only those things that seemed >>> related to quotas; especially in the EXT3 case more can be done >>> (later?). >>> >> >> >> It seems sad to do it in each filesystem. Is there no way in which >> we can >> do this for all filesystems, in a single place in the VFS? >> >> > Each file system must be able to echo it's own FS specific options, > hence the show_options hook (XFS is a good example). EXT3 has it's own > form of journalled quota file options, hence the need for the specific > hook. > > The "older style" (e.g. "usrquota", "grpquota", "quota") could be done > generically but a FS might want any number of quota options. The few > lines of code in each file system didn't seem so bad especially if the > show_function start echoing more. Followup comment/through... If we want /proc/mounts to really replace /etc/mtab in the general case, always using it as a symlink, the file system codes will all need the show_options hook - they will need to echo all of their private options duplicating, as closely as possible, what would have been written to the /etc/mtab regular file. mark mark