From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754851AbZEKOAY (ORCPT ); Mon, 11 May 2009 10:00:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752573AbZEKOAI (ORCPT ); Mon, 11 May 2009 10:00:08 -0400 Received: from host-216-57-134-2.customer.veroxity.net ([216.57.134.2]:29135 "EHLO mars.virtualiron.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752300AbZEKOAH (ORCPT ); Mon, 11 May 2009 10:00:07 -0400 X-Greylist: delayed 668 seconds by postgrey-1.27 at vger.kernel.org; Mon, 11 May 2009 10:00:07 EDT Date: Mon, 11 May 2009 09:45:34 -0400 From: Konrad Rzeszutek To: device-mapper development , tj@kernel.org Cc: Kay Sievers , jeff@garzik.org, linux-scsi@vger.kernel.org, Mauelshagen@redhat.com, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, jens.axboe@oracle.com, martin.petersen@oracle.com Subject: Re: [dm-devel] Re: [PATCH 1/3] block: add alt_size Message-ID: <20090511134534.GA32678@mars.virtualiron.com> References: <1241828002-12742-1-git-send-email-tj@kernel.org> <1241828002-12742-2-git-send-email-tj@kernel.org> <4A058D5C.6030206@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A058D5C.6030206@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org .. snip .. > > Also, values with magic block counts, while there is no way to get the > > blocksize with the same interface, are pretty weird. I think the > > current "size" attribute is just a bug. > > Logical block size is fixed at 512 bytes. Offset and size are always > represented in multiples of 512 bytes and only get converted to > hardware block size in the lld. That interpretation is at odds with the work that Martin Peterson is doing with the 4K support. In the e-mail titled: "Re: [PATCH 4 of 8] sd: Physical block size and alignment support", Message-ID: he says: " Konrad> about what a 'logical block', and 'physical block' is Konrad> vs. 'hardware sector' ? Well, another item on my todo list is to kill the notion of hardware sector completely. The protocols have been referring to logical blocks for ages. It hasn't been a big problem until now because logical block size has been equal to the hardware sector size. That's no longer a valid assumption. " Are the ATA/SCSI/etc specs at odds with each other about this?