From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1420C43387 for ; Mon, 14 Jan 2019 12:50:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFA7B20656 for ; Mon, 14 Jan 2019 12:50:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbfANMuV (ORCPT ); Mon, 14 Jan 2019 07:50:21 -0500 Received: from mx2.suse.de ([195.135.220.15]:36078 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726449AbfANMuU (ORCPT ); Mon, 14 Jan 2019 07:50:20 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 829F3AE86; Mon, 14 Jan 2019 12:50:18 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id D078A1E157A; Mon, 14 Jan 2019 13:50:17 +0100 (CET) Date: Mon, 14 Jan 2019 13:50:17 +0100 From: Jan Kara To: Geert Uytterhoeven Cc: Andreas Dilger , Jan Kara , Theodore Tso , Ext4 Developers List , Linux Kernel Mailing List Subject: Re: Preserving a rev 0.0 ext2 filesystem Message-ID: <20190114125017.GI13316@quack2.suse.cz> References: <3A06C183-19FF-48B3-9C49-60353BEC9DB8@dilger.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 14-01-19 11:23:30, Geert Uytterhoeven wrote: > Thanks, since ext2 also has the ext2_update_dynamic_rev() function, I > assumed it would be called as well. But indeed, mounting the old file > system using the real ext2 driver retains its revision. Thanks for trying that out and I'm glad that it still works ;) > JFYI, this is what was changed by mounting and unmounting it using the > ext2 driver: > > --- ramdisk.orig 2019-01-14 09:23:15.578434706 +0100 > +++ ramdisk.mounted-by-ext2 2019-01-14 09:23:16.362434253 +0100 > @@ -3,7 +3,7 @@ > 00000400 f8 00 00 00 78 05 00 00 00 00 00 00 20 00 00 00 |....x....... ...| > 00000410 09 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 |................| > 00000420 00 20 00 00 00 20 00 00 f8 00 00 00 f7 5e a3 32 |. ... .......^.2| > -00000430 9e 5e a3 32 03 00 14 00 53 ef 01 00 01 00 00 00 |.^.2....S.......| > +00000430 84 46 3c 5c 04 00 14 00 53 ef 01 00 01 00 00 00 |.F<\....S.......| > 00000440 53 5d a3 32 00 4e ed 00 00 00 00 00 00 00 00 00 |S].2.N..........| > 00000450 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > 00000460 00 00 00 00 00 00 00 00 87 6b 6d 86 4c 96 11 d0 |.........km.L...| > > Which is just the last write time, and mount count, as expected. > Interestingly, the last mount time was not updated. Yeah, that looks like a bug that got introduced in 269c8db30cf5b6 "ext2: Set the write time in ext2_sync_fs()" in 2010. I'll fix it. Thanks for report. Honza -- Jan Kara SUSE Labs, CR