From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCHSET pata-2.6] ide: rq->buffer, data, special and misc cleanups Date: Mon, 13 Apr 2009 03:54:38 -0400 Message-ID: <49E2EFBE.5000709@garzik.org> References: <49D1D7A3.40303@panasas.com> <49D1DCE2.1050201@kernel.org> <49D214E7.2040908@panasas.com> <20090413163957P.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:53259 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbZDMHyx (ORCPT ); Mon, 13 Apr 2009 03:54:53 -0400 In-Reply-To: <20090413163957P.fujita.tomonori@lab.ntt.co.jp> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: FUJITA Tomonori Cc: bharrosh@panasas.com, tj@kernel.org, petkovbb@gmail.com, bzolnier@gmail.com, linux-kernel@vger.kernel.org, axboe@kernel.dk, linux-ide@vger.kernel.org FUJITA Tomonori wrote: > On Tue, 31 Mar 2009 16:04:39 +0300 > Boaz Harrosh wrote: > >>> I >>> just don't think bvec should be used outside of block/fs interface. >>> As I wrote before, non-FS users have no reason to worry about bio. >>> All it should think about is the requst it needs to issue and the >>> memory area it's gonna use as in/out buffers. bio just doesn't have a >>> place there. >>> >> I don't understand what happens to all the people that start to work on the block >> layer, they start getting defensive about bio being private to the request >> level. But the Genie is out of the bag already (I know cats and bottles). >> bio is already heavily used above the block layer from directly inside filesystems >> to all kind of raid engines, DM MD managers, multi paths, integrity information ... >> >> Because bio is exactly that Ideal page carrier you are talking about. > > Wrong. multi path doesn't use bio. md accesses to the bio internal > (it's not nice) and has the own way to carry pages. dm has the own > mechanism on the top of bio. And bio doesn't work nicely for file > systems such as btrfs, which handle multiple devices. > > Please stop your wrong argument 'bio is the ideal page carrier'. What is the multi-device problem with bio? The idea behind bio is to be the ideal page carrier :) It sounds like bio needs revision, not abandonment. Jeff