From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1N0BnI-0007Tm-Fp for mharc-grub-devel@gnu.org; Tue, 20 Oct 2009 06:18:20 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N0BnG-0007TP-Oi for grub-devel@gnu.org; Tue, 20 Oct 2009 06:18:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N0BnC-0007Sp-Sx for grub-devel@gnu.org; Tue, 20 Oct 2009 06:18:18 -0400 Received: from [199.232.76.173] (port=47750 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N0BnC-0007Se-OK for grub-devel@gnu.org; Tue, 20 Oct 2009 06:18:14 -0400 Received: from xvm-190-8.ghst.net ([217.70.190.8]:56994 helo=aybabtu.com) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1N0BnC-00078G-8K for grub-devel@gnu.org; Tue, 20 Oct 2009 06:18:14 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1N0Bn8-0002tH-Vh for grub-devel@gnu.org; Tue, 20 Oct 2009 12:18:11 +0200 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1N0Bn8-000157-Ca for grub-devel@gnu.org; Tue, 20 Oct 2009 12:18:10 +0200 Date: Tue, 20 Oct 2009 12:18:10 +0200 From: Robert Millan To: The development of GRUB 2 Message-ID: <20091020101810.GA3952@thorin> References: <20091016205258.GA8496@thorin> <4AD8E0CF.9080509@gmail.com> <20091016215343.GA9378@thorin> <4AD8F11D.1030007@gmail.com> <20091017112545.GA3556@thorin> <4AD9ADE9.3020004@gmail.com> <20091017120013.GA4040@thorin> <4AD9B3FB.9000904@gmail.com> <20091018154608.GA27494@thorin> <4ADB4293.6070703@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4ADB4293.6070703@gmail.com> Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) Subject: Re: [PATCH] Refuse to install on XFS destroying its superblock X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Oct 2009 10:18:19 -0000 On Sun, Oct 18, 2009 at 06:30:11PM +0200, Vladimir 'phcoder' Serbinenko wrote: > Robert Millan wrote: > > On Sat, Oct 17, 2009 at 02:09:31PM +0200, Vladimir 'phcoder' Serbinenko wrote: > > > >>>> The danger is that fs_probe may reject filesystem as valid just because > >>>> it's newer than expected. > >>>> > >>>> > >>> What do you mean with "reject filesystem as valid"? > >>> > >>> > >>> > >> Sorry for being unclear. I just meant that if some XFS structures are > >> updated then our xfs driver won't recognise it as xfs > >> > > > > What do you mean with "updated"? You mean a new implementation of XFS? Or > > the same instance of XFS that has been modified after use? > > > > > I mean next version on XFS Sorry, but what did you expect? You want to prevent PEBCAK using heuristic. There's no way we can tell if those 512 bytes are valuable data, only the user can. And even if you try to err on the safest side, there's no garantee that newer versions of XFS, or other filesystems that don't even exist yet will be detectable by us no matter what we do. Why don't we just take a backup like someone suggested a while ago? I think there was even a patch. This way if valuable data is lost, user can restore it (and while at it, learnt his lesson that filesystems and embedded code aren't really supposed to be mixed in the same place). -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."