From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264188AbUDGUBJ (ORCPT ); Wed, 7 Apr 2004 16:01:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264196AbUDGUBJ (ORCPT ); Wed, 7 Apr 2004 16:01:09 -0400 Received: from fw.osdl.org ([65.172.181.6]:65427 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S264188AbUDGUBG (ORCPT ); Wed, 7 Apr 2004 16:01:06 -0400 Date: Wed, 7 Apr 2004 13:03:08 -0700 From: Andrew Morton To: Andy Isaacson Cc: bug-coreutils@gnu.org, linux-kernel@vger.kernel.org Subject: Re: dd PATCH: add conv=direct Message-Id: <20040407130308.7c7ec8dc.akpm@osdl.org> In-Reply-To: <20040407194727.GE2814@hexapodia.org> References: <20040406220358.GE4828@hexapodia.org> <20040406173326.0fbb9d7a.akpm@osdl.org> <20040407173116.GB2814@hexapodia.org> <20040407111841.78ae0021.akpm@osdl.org> <20040407192432.GD2814@hexapodia.org> <20040407123455.0de9ffa9.akpm@osdl.org> <20040407194727.GE2814@hexapodia.org> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andy Isaacson wrote: > > I claim that O_DIRECT on of= is important because you just plain *can > not* do the minimal-sized IDE block scrub without it. I don't yet see a > similar benefit to O_DIRECT on if= side. If you want a block scrubber then write a block scrubber. If you want to add O_DIRECT support to dd then it should be implemented properly, and that means implementing it for both read and write. In fact the user should be able to specify the read-O_DIRECT and the write-O_DIRECT independently - if for no other reason than that the source and dest filesytems may not both support O_DIRECT.