From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 8 Feb 2001 06:33:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 8 Feb 2001 06:33:21 -0500 Received: from [194.213.32.137] ([194.213.32.137]:3076 "EHLO bug.ucw.cz") by vger.kernel.org with ESMTP id ; Thu, 8 Feb 2001 06:33:08 -0500 Message-ID: <20010208004938.E189@bug.ucw.cz> Date: Thu, 8 Feb 2001 00:49:38 +0100 From: Pavel Machek To: Andreas Dilger , Jeffrey Keller Cc: sct@redhat.com, linux-kernel@vger.kernel.org Subject: Re: Reasons to honor readonly mount requests In-Reply-To: <3A7B7F8C.67C2B603@commerceflow.com> <200102030359.f133xrM02216@webber.adilger.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93i In-Reply-To: <200102030359.f133xrM02216@webber.adilger.net>; from Andreas Dilger on Fri, Feb 02, 2001 at 08:59:53PM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > I understand that both ext3fs and > > reiserfs will try to fix corrupt filesystems (or at least filesystems > > with unprocessed log entries) in-place even if they're mounted > > read-only. Clearly, virtual replay means more work, but -- just for > > fun -- here are some cases in which it might matter: > > > > 1. You want the disk image untouched for forensic analysis or data > > recovery. > > 2. You don't trust the disk to do writes properly. > > 3. You don't trust the driver to do writes properly. > > 4. You want to test a newer or unstable FS implementation w/ option to > > go back to the older one. > > Excluding the root fs (which probably isn't involved in these sorts of > things anyways), you can always turn off the "RECOVERY" flag on the > filesystem and mount ext3 as ext2, which will not do any recovery. _If_ you happen to realize that mount -o ro -t ext3 is not really read only. sct know it may write to filesystem, now I know it; but I believe that if you asked Joe Admin "Linux writes to partition mounted read-only in some cases; is it a bug?" he would say "YES!" Pavel -- I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care." Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/