From: Theodore Tso Subject: Re: The meaning of data=ordered as it relates to delayed allocation Date: Mon, 19 Jan 2009 07:45:13 -0500 Message-ID: <20090119124513.GC7598@mit.edu> References: <20090119044345.GB9482@skywalker> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: "Aneesh Kumar K.V" Return-path: Received: from THUNK.ORG ([69.25.196.29]:56136 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759439AbZASMpQ (ORCPT ); Mon, 19 Jan 2009 07:45:16 -0500 Content-Disposition: inline In-Reply-To: <20090119044345.GB9482@skywalker> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Jan 19, 2009 at 10:13:45AM +0530, Aneesh Kumar K.V wrote: > > So I wonder if we should either: > > > > (a) make data=ordered force block allocation and writeback --- which > > should just be a matter of disabling the > > redirty_page_for_writepage() code path in ext4_da_writepage() > > We can't do that because we cannot do block allocation there. So we need > to redirty the page that have unmapped buffer_heads. What is preventing us from doing block allocation from ext4_da_writepage()? - Ted