From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 1 Sep 2001 10:42:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 1 Sep 2001 10:42:31 -0400 Received: from asterix.hrz.tu-chemnitz.de ([134.109.132.84]:22484 "EHLO asterix.hrz.tu-chemnitz.de") by vger.kernel.org with ESMTP id ; Sat, 1 Sep 2001 10:42:23 -0400 Date: Sat, 1 Sep 2001 16:42:38 +0200 From: Ingo Oeser To: Alexander Viro Cc: Bryan Henderson , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [RFD] readonly/read-write semantics Message-ID: <20010901164238.P9870@nightmaster.csn.tu-chemnitz.de> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: ; from viro@math.psu.edu on Sat, Sep 01, 2001 at 12:23:05AM -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 01, 2001 at 12:23:05AM -0400, Alexander Viro wrote: > > 2) I'd like to see a readonly mount state defined as "the filesystem will > > not change. Period." Not for system calls in progress, not for cache > > synchronization, not to set an "unmounted" flag, not for writes that are > > queued in the device driver or device. (That last one may stretch > > feasability, but it's a worthy goal anyway). > > It doesn't work. Think of r/o mounting of remote filesystem. Do you > suggest that it should make it impossible to change from other clients? It's sufficient for local file systems. Or see it this way: The machine, that mounted it r/o will NOT write to it until it is mounted r/w again. I also like the "kill/finish all outstanding writes" idea (kill or finish should depend on the MNT_FORCE option). Once we've implemented it, forcible unmount becomes trivial ;-) Forcible unmount is high on the wish list of several admins I know. Regards Ingo Oeser