From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:59679 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752120AbbCWSCu (ORCPT ); Mon, 23 Mar 2015 14:02:50 -0400 Date: Mon, 23 Mar 2015 14:02:45 -0400 From: Vivek Goyal To: Josef Bacik Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, zab@redhat.com, fstests@vger.kernel.org Subject: Re: [dm-devel] [PATCH 1/3] dm: log writes target Message-ID: <20150323180245.GE3172@redhat.com> References: <1426797070-27463-1-git-send-email-jbacik@fb.com> <1426797070-27463-2-git-send-email-jbacik@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1426797070-27463-2-git-send-email-jbacik@fb.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Mar 19, 2015 at 04:31:08PM -0400, Josef Bacik wrote: [..] > + * We log writes only after they have been flushed, this makes the log describe > + * close to the order in which the data hits the actual disk, not its cache. So > + * for example the following sequence (W means write, C means complete) > + * > + * Wa,Wb,Wc,Cc,Ca,FLUSH,FUAd,Cb,CFLUSH,CFUAd > + * > + * Would result in the log looking like this > + * > + * c,a,flush,fuad,b,, > + * A minor nit, Should this sequence be following. c,a,b, flush,fuad,, when flush completed by that time write of b has completed too. So it should be written first? Thanks Vivek