From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267360AbUHDRbX (ORCPT ); Wed, 4 Aug 2004 13:31:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267363AbUHDRbX (ORCPT ); Wed, 4 Aug 2004 13:31:23 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:12229 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S267360AbUHDRbT (ORCPT ); Wed, 4 Aug 2004 13:31:19 -0400 Date: Wed, 4 Aug 2004 19:31:11 +0200 From: Jens Axboe To: Andi Kleen Cc: "David S. Miller" , linux-kernel@vger.kernel.org Subject: Re: block layer sg, bsg Message-ID: <20040804173111.GB5978@suse.de> References: <2ppN4-1wi-11@gated-at.bofh.it> <2pvps-5xO-33@gated-at.bofh.it> <2pvz2-5Lf-19@gated-at.bofh.it> <2pwbQ-68b-43@gated-at.bofh.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 04 2004, Andi Kleen wrote: > "David S. Miller" writes: > > > > Or use a more portable well-defined type which does not change > > size nor layout between 32-bit and 64-bit environments. > > That is usually a mistake. People get the more subtle issues > like long long handling wrong, and then it is impossible to fix it > anymore in a compat layer (examples are ipsec and iptables, which > cannot be emulated on x86-64 because of that) > > So please never pass any structures with read/write/netlink. Which basically brings us back to SG_IO, or (alternatively) SG_IO_WRITE and SG_IO_READ ioctls. I doubt that is really worth it, however. There's just not a huge need to do it. -- Jens Axboe