Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932254AbWHJVBE (ORCPT ); Thu, 10 Aug 2006 17:01:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932344AbWHJVBA (ORCPT ); Thu, 10 Aug 2006 17:01:00 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:33670 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932254AbWHJVAc (ORCPT ); Thu, 10 Aug 2006 17:00:32 -0400 Message-ID: <44DB9E6C.9070808@garzik.org> Date: Thu, 10 Aug 2006 17:00:28 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.4 (X11/20060614) MIME-Version: 1.0 To: Andrew Morton CC: Badari Pulavarty , cmm@us.ibm.com, linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 1/5] Forking ext4 filesystem from ext3 filesystem References: <1155172622.3161.73.camel@localhost.localdomain> <20060809233914.35ab8792.akpm@osdl.org> <44DB8036.5020706@us.ibm.com> <44DB936D.2080909@garzik.org> <20060810132720.4d9fced4.akpm@osdl.org> In-Reply-To: <20060810132720.4d9fced4.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.3 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 861 Lines: 28 Andrew Morton wrote: > On Thu, 10 Aug 2006 16:13:33 -0400 > Jeff Garzik wrote: > >> The sooner we kill buffer heads and use submit_bio(), the better :) > > A buffer_head is a caching entity and a bio is an IO container. They're > quite separate concepts. Yeah, sorry, I meant direct pagecache I/O. I forgot that bio doesn't handle caching. > A buffer_head is the kernel's sole abstraction of a disk block. > Filesystems use disk blocks a lot, and they need such an abstraction. IMO Al Viro work has shown that you can do pagecache I/O without needing such a heavyweight system. Jeff - 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/