From: Alex Tomas Subject: Re: booked-page-flag.patch Date: Fri, 16 Feb 2007 00:07:55 +0300 Message-ID: References: <20070215004504.023a90f0.akpm@linux-foundation.org> <45D495EA.3060200@redhat.com> <20070215125654.b0f18ab3.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alex Tomas , Eric Sandeen , "Theodore Ts'o" , "linux-ext4@vger.kernel.org" To: Andrew Morton Return-path: Received: from [80.71.245.246] ([80.71.245.246]:59517 "EHLO nsold.rialcom.ru" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1161297AbXBOVHz (ORCPT ); Thu, 15 Feb 2007 16:07:55 -0500 In-Reply-To: <20070215125654.b0f18ab3.akpm@linux-foundation.org> (Andrew Morton's message of "Thu\, 15 Feb 2007 12\:56\:54 -0800") Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org >>>>> Andrew Morton (AM) writes: AM> If the page doesn't have buffer-heads, set PG_private and clear page->private AM> If the page does have buffer_heads, use BH_Delay. I did exactly this way in the first version, but later got feeling that the community'd discard "ugly hack". one more question: how much of it you want in VFS? ->get_block(with BH_Delay) can be used to signal filesystem that no actual allocation is required. so, aware filesystem can just reserve space. then ->writepages() should walk through the pages like it does currently, collect contiugous sequences and again call ->get_block(w/o BH_Delay) with b_size covering all contiguous pages ... thanks, Alex