From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755988Ab2BMV5B (ORCPT ); Mon, 13 Feb 2012 16:57:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:17171 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754207Ab2BMV5A (ORCPT ); Mon, 13 Feb 2012 16:57:00 -0500 Date: Mon, 13 Feb 2012 16:56:50 -0500 From: Vivek Goyal To: Phillip Susi Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, dm-devel@redhat.com, Karel Zak , maxim.patlasov@gmail.com Subject: Re: [PATCH 0/2] block: online resize of disk partitions Message-ID: <20120213215650.GE3130@redhat.com> References: <1329161438-12602-1-git-send-email-vgoyal@redhat.com> <4F3981FE.7090601@ubuntu.com> <20120213215039.GD3130@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120213215039.GD3130@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 13, 2012 at 04:50:39PM -0500, Vivek Goyal wrote: [..] > > as well as to allow for the > > possibility of extending the interface in the future to allow changing > > the start as well as the length. > > Even if we allow changing start at some point of time, then IOCTL can > remain the same and just the implementation will change in a backward > compatible manner. Old tools still will continue to work as they have > always been, and new ones can start passing "start" too. Let me thake that back. Changes will not be backward compatible as if old tools run on new kernel specifying start as 0, then change will fail on newer kernels which might allow changing start too. Do you really expect that changing start will really be useful? If yes, then it does make a case for not leaving "start" undefined. Thanks Vivek