Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 27 Feb 2003 14:37:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 27 Feb 2003 14:37:54 -0500 Received: from daimi.au.dk ([130.225.16.1]:29352 "EHLO daimi.au.dk") by vger.kernel.org with ESMTP id ; Thu, 27 Feb 2003 14:37:03 -0500 Message-ID: <3E5E6B39.3DD1C6A@daimi.au.dk> Date: Thu, 27 Feb 2003 20:47:05 +0100 From: Kasper Dupont Organization: daimi.au.dk X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.4.18-19.7.xsmp i686) X-Accept-Language: en MIME-Version: 1.0 To: Dominik Kubla CC: Horst von Brand , Miles Bader , DervishD , Linux-kernel Subject: Re: About /etc/mtab and /proc/mounts References: <200302271600.h1RG0Cdh011948@eeyore.valparaiso.cl> <200302271740.06139.dominik@kubla.de> Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2367 Lines: 41 Dominik Kubla wrote: > > So there are quite some differences between the Linux proc file and > the Solaris mntfs filesystem. If these differences justify us doing it the > same way is debateable. > > The strongest argument i see is: It's already been done this way by one > major Unix version, so why should Linux reinvent the wheel. Again. The reason for implementing that would IMHO not be to just get the features that solaris has, but rather to get rid of /etc/mtab. I guess we all agree, that a kernel implementation, that being a misc char device or a proc pseudo file would be better than the current /etc/mtab file. But I think a kernel implementation is also the most tricky. Bind mounting /proc/mounts onto /etc/mtab would to some extent resemble the solaris implementation, but there are noticable differences. I think one major question is if we can actually make a kernel implementation that without help from userspace will provide all the information that we have usually gotten from /etc/mtab. If that is possible, I think we should aim for that and thereby make /etc/mtab obsolete. Then we can eventually replace /etc/mtab with a symlink pointing to /proc/mtab, /proc/self/mtab, or /proc/1/mtab. The fact that solaris makes a snapshot of the mountpoints might be convenient, but really not that important. The correct size reported by stat is also just a convenience. The exact reporting of mtime is as already pointed out of real value to some applications. And the ioctl to get major and minor is certainly helpful if the device field is reused for other purposes in the case of bind mounts and loopback mounts. Does solaris actually have those features, and what does mnttab report in those cases? And while we are discussing bind mounts, there is one feature that I have sometimes missed: A possibility to directly mount a subdirectory of a filesystem without having to mount the root of that filesystem first and use a bindmount afterwards. -- Kasper Dupont -- der bruger for meget tid p? usenet. For sending spam use mailto:aaarep@daimi.au.dk for(_=52;_;(_%5)||(_/=5),(_%5)&&(_-=2))putchar(_); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/