Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265516AbTIDVFI (ORCPT ); Thu, 4 Sep 2003 17:05:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265323AbTIDVFI (ORCPT ); Thu, 4 Sep 2003 17:05:08 -0400 Received: from thebsh.namesys.com ([212.16.7.65]:61917 "HELO thebsh.namesys.com") by vger.kernel.org with SMTP id S265516AbTIDVDF (ORCPT ); Thu, 4 Sep 2003 17:03:05 -0400 Message-ID: <3F57A887.9040706@namesys.com> Date: Fri, 05 Sep 2003 01:03:03 +0400 From: Hans Reiser User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3a) Gecko/20021212 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Mike Fedyk CC: Andrew Morton , reiserfs-list@namesys.com, linux-kernel@vger.kernel.org Subject: Re: precise characterization of ext3 atomicity References: <3F574A49.7040900@namesys.com> <20030904085537.78c251b3.akpm@osdl.org> <3F576176.3010202@namesys.com> <20030904091256.1dca14a5.akpm@osdl.org> <3F57676E.7010804@namesys.com> <20030904181540.GC13676@matchmail.com> <3F578656.60005@namesys.com> <20030904191255.GE13676@matchmail.com> In-Reply-To: <20030904191255.GE13676@matchmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1555 Lines: 60 Mike Fedyk wrote: >On Thu, Sep 04, 2003 at 10:37:10PM +0400, Hans Reiser wrote: > > >>Mike Fedyk wrote: >> >> >> >>>On Thu, Sep 04, 2003 at 08:25:18PM +0400, Hans Reiser wrote: >>> >>> >>> >>> >>>>In data=journal and data=ordered modes ext3 also guarantees that the >>>>metadata will be committed atomically with the data they point to. >>>>However ext3 does not provide user data atomicity guarantees beyond the >>>>scope of a single filesystem disk block (usually 4 kilobytes). If a >>>>single write() spans two disk blocks it is possible that a crash partway >>>>through the write will result in only one of those blocks appearing in >>>>the file after recovery. >>>> >>>> >>>> >>>> >>>And how does reiser4 do this without changing the userspace apps? >>> >>> >>> >>We don't. We just make the hovercraft, we don't force you to go over >>the water..... >> >> > >So by default with no user space modifications, reiser4 will be atomic for >each write() call, and ext3 will if it aligns withing a single page. > >Is that correct? > Yes. > >Then you can go on to specify that you can have larger transactions if you >make some changes to the userspace apps. > > > > or you are a programmer who writes code....;-) It's not that hard to write code....;-) -- Hans - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/