From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263886AbTEGQQQ (ORCPT ); Wed, 7 May 2003 12:16:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263970AbTEGQQP (ORCPT ); Wed, 7 May 2003 12:16:15 -0400 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:10244 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id S263886AbTEGQQO (ORCPT ); Wed, 7 May 2003 12:16:14 -0400 Date: Wed, 7 May 2003 09:28:30 -0700 (PDT) From: Linus Torvalds To: Jens Axboe cc: Bartlomiej Zolnierkiewicz , Linux Kernel Subject: Re: [PATCH] 2.5 ide 48-bit usage In-Reply-To: <20030507084920.GA823@suse.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 May 2003, Jens Axboe wrote: > > I did a patch for 2.4 some weeks ago that added (what I consider) proper > 48-bit lba usage to ide-disk. Ok, let me disagree a bit. At least if I read the patch correctly, theer's no way for upper layers to say "I want 48-bit addressing" - it's just turned on automatically for high sectors (or big transfers). Well, you can mark the drive itself as wanting 48-bit transfers, but you can't do it on a per-request basis. And I think this is 100% equivalent to the 6 vs 10 vs 16-byte SCSI command issue, and I really think it should b esolved the same way. Namely, you should be able to (on a "struct request" level) explicitly say that you want the big requests, and then the default prep_fn() would do roughly what you do now by default. That way something like a SG_IO interface could force one mode or the other on a per-request basis. Comments? Linus