From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752171Ab0CHAJQ (ORCPT ); Sun, 7 Mar 2010 19:09:16 -0500 Received: from mail.parknet.co.jp ([210.171.160.6]:47975 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002Ab0CHAJM (ORCPT ); Sun, 7 Mar 2010 19:09:12 -0500 From: OGAWA Hirofumi To: "H. Peter Anvin" Cc: Andrew Morton , Daniel Taylor , linux-kernel@vger.kernel.org Subject: Re: [PATCH] msdos: add support for large disks References: <3E0C3AE547FA504DA5E89EA5A24AC85803E2BD2D@wdscexbe01.sc.wdc.com> <20100301141335.395dc4c3.akpm@linux-foundation.org> <873a0h1p2c.fsf@devron.myhome.or.jp> <876358iehd.fsf@devron.myhome.or.jp> <4B9430B6.701@zytor.com> Date: Mon, 08 Mar 2010 09:09:08 +0900 In-Reply-To: <4B9430B6.701@zytor.com> (H. Peter Anvin's message of "Sun, 07 Mar 2010 15:03:18 -0800") Message-ID: <87pr3fd68r.fsf@devron.myhome.or.jp> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "H. Peter Anvin" writes: > On 03/07/2010 02:59 AM, OGAWA Hirofumi wrote: >> This part is broken. If "size" is smaller than minimum blocksize (note, >> "size" is number of 512b, not number of blocksize), we can't read any >> block after all (it is handled as outside of i_size by bdev). >> >> Peter (or someone) know what do we want to in here? This is on extended > > partition itself (e.g. if sda1 sda2, it's the size of sda2) > > We should presumably set it to one logical sector, regardless of size. > Either that, or the offset of the lowest contained partition. It means, min(size, max(logical_sector_size / 512, 2)); or like this? ("size" is "nr_sects(part) * (logical_sector_size/512)") This should keep old logic, i.e. if partition is bigger than 1kb, it uses 1kb for (probably) LILO mentioned by comment. >> [BTW, it seems subtypes stuff is not thinking about sector size> 512b...] > > Much else isn't, either. With the exception of some MO disks, it was > nearly unheard of for 20 years. Yes. So, well, if someone know the spec of those subtypes, let us know. Thanks. -- OGAWA Hirofumi