From: Alex Tomas Subject: Re: [dm-devel] Re: jbd2 inside a device mapper module Date: Tue, 30 Dec 2008 09:55:57 +0300 Message-ID: <4959C5FD.3050305@sun.com> References: <20081225143535.GA4127@blitiri.com.ar> <20081227200127.GX5000@webber.adilger.int> <46A00B48CC54E4468EF6911F877AC4CA01DDBB66@blrx3m10.blr.amer.dell.com> <20081229210537.GN4127@blitiri.com.ar> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Cc: Shyam_Iyer@Dell.com, dm-devel@redhat.com, linux-ext4@vger.kernel.org, tytso@MIT.EDU, linux-kernel@vger.kernel.org To: Alberto Bertogli Return-path: Received: from gmp-eb-inf-1.sun.com ([192.18.6.21]:48822 "EHLO gmp-eb-inf-1.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbYL3HJC (ORCPT ); Tue, 30 Dec 2008 02:09:02 -0500 In-reply-to: <20081229210537.GN4127@blitiri.com.ar> Sender: linux-ext4-owner@vger.kernel.org List-ID: one good thing about JBD is that you can't update target block and csum atomically. so, either you use some form of COW or you use journalling. given we already have JBD it'd make sense to use it? thanks, Alex Alberto Bertogli wrote: > I think I'll go with the "two metadatas" approach and see how it goes. > Worst case scenario is that I have to drop that code, which means to be > back where I am now, only with one less option. > > Thanks, > Alberto >