From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265096AbUFRK0B (ORCPT ); Fri, 18 Jun 2004 06:26:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265100AbUFRK0B (ORCPT ); Fri, 18 Jun 2004 06:26:01 -0400 Received: from linuxhacker.ru ([217.76.32.60]:3006 "EHLO shrek.linuxhacker.ru") by vger.kernel.org with ESMTP id S265096AbUFRKV7 (ORCPT ); Fri, 18 Jun 2004 06:21:59 -0400 Date: Fri, 18 Jun 2004 13:15:20 +0300 From: Oleg Drokin To: Helge Hafting Cc: Petter Larsen , linux-kernel@vger.kernel.org, ext3 Subject: Re: mode data=journal in ext3. Is it safe to use? Message-ID: <20040618101520.GA2389@linuxhacker.ru> References: <40FB8221D224C44393B0549DDB7A5CE83E31B1@tor.lokal.lan> <1087322976.1874.36.camel@pla.lokal.lan> <200406160734.i5G7YZwV002051@car.linuxhacker.ru> <1087460837.2765.31.camel@pla.lokal.lan> <20040617170939.GO2659@linuxhacker.ru> <40D2B8C3.8090908@hist.no> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40D2B8C3.8090908@hist.no> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello! On Fri, Jun 18, 2004 at 11:41:23AM +0200, Helge Hafting wrote: > >If you can reproduce a garbage in files in ordered journal mode, that > >would be a > >bug that should be fixed then. > Hard to _produce_, but consider: > 1. Write data to an existing file > 2. Sync metadata > 3. data is forced out because of ordered mode, a powerout crash happens > in the middle of this. The file now has a block with a mix of new > and old, Well, this is not much worse than having two blocks, one from old file and one from new after a crash. > it may even be unreadable due to a bad sector checksum. Well, in data journaled mode you may get unreadable journal, is this much better? (Also original question was about CF flash media, so no bad sector problems I presume). > With data journalling you either get the old data (because the crash > happened > during a write to the journal) or new data (crash happened during data > write, Well, while with data journaling mode your granularity is one block, with data ordered it is one sector. > the data is restored from the good copy in the journal.) Bye, Oleg