From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.105.134] helo=mgw-mx09.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1LoXOr-0002ZN-AG for linux-mtd@lists.infradead.org; Tue, 31 Mar 2009 06:24:47 +0000 Subject: Re: ubifs version 1 compatibility From: Artem Bityutskiy To: Hamish Moffatt In-Reply-To: <20090326131550.GA15665@cloud.net.au> References: <20090326051508.GA4760@cloud.net.au> <1238049297.3321.20.camel@localhost.localdomain> <20090326074443.GA7842@cloud.net.au> <1238061023.3321.67.camel@localhost.localdomain> <20090326120431.GA13745@cloud.net.au> <1238069525.3321.83.camel@localhost.localdomain> <20090326131550.GA15665@cloud.net.au> Content-Type: text/plain; charset="UTF-8" Date: Tue, 31 Mar 2009 09:23:38 +0300 Message-Id: <1238480618.20906.6.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2009-03-27 at 00:15 +1100, Hamish Moffatt wrote: > On Thu, Mar 26, 2009 at 02:12:05PM +0200, Artem Bityutskiy wrote: > > On Thu, 2009-03-26 at 23:04 +1100, Hamish Moffatt wrote: > > > On Thu, Mar 26, 2009 at 11:50:23AM +0200, Artem Bityutskiy wrote: > > > > On Thu, 2009-03-26 at 18:44 +1100, Hamish Moffatt wrote: > > > > makes it very difficult to turn old image into new one. This will > > > > basically mean we need: > > > > > > > > 1. extract files from the old image > > > > 2. feed them to mkfs.ubifs. > > > > > > > > > Maybe before upgrade we could run mkfs.ubifs using the contents of the > > > > > existing volume to create the new format, unmount it and ubiupdatevol it.. > > > > > > > > The easiest way to do this is to boot the old kernel, > > > > e.g. in vmware, extract the files using the nandsim technique: > > > > http://www.linux-mtd.infradead.org/faq/ubifs.html#L_ubifs_nandsim > > > > > > > > then feed them to mkfs.ubifs. > > > > > > Well I have these files on embedded devices out in the real world. The > > > volume is storing user data, so I need to do this change in-place. > > > > Let me make sure I understand the need. > > > > So you have devises with v1 format in the wild. You want to upgrade > > those devices. While upgrading, you will re-write some UBI volumes, but > > after upgrade the user-data volume should contains exactly the same data > > as before the upgrade, right? > > Yes, that's what I need. I see. Well, because most of the UBIFS functionality is in the kernel, it might probably be possible to teach the kernel UBIFS implementation to automatically re-format the file-system if it finds v.1 layout. However, this is not a very simple task, and I am not sure I have time to implement this, sorry :-( -- Best regards, Artem Bityutskiy (Битюцкий Артём)