From: Ted Ts'o Subject: Re: Regular ext4 error warning with HD in USB dock Date: Sat, 8 Jan 2011 17:00:59 -0500 Message-ID: <20110108220059.GV21922@thunk.org> References: <201012280953.46149.kernel@kolivas.org> <20101228025343.GD10149@thunk.org> <20101228081917.GA1351@bitwizard.nl> <4D1F6244.7050203@redhat.com> <20110107052613.GE2857@thunk.org> <20110108080520.GE12433@bitwizard.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Amir Goldstein , Ric Wheeler , Con Kolivas , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org To: Rogier Wolff Return-path: Received: from thunk.org ([69.25.196.29]:36121 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751641Ab1AHWBJ (ORCPT ); Sat, 8 Jan 2011 17:01:09 -0500 Content-Disposition: inline In-Reply-To: <20110108080520.GE12433@bitwizard.nl> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, Jan 08, 2011 at 09:05:20AM +0100, Rogier Wolff wrote: > Although those two numbers are equal right now, there is no reason to > assume that they will remain so in the future. So if the superblock > size (or the offset) changes in the future, it's much better to have > programmed this so that it will keep on working as opposed to getting > to deal with ugly bugs in code that hasn't changed in years... No. The superblock nor its offset will never change. It's like the syscall ABI, only worse. If we changed it would break *everybody*. Fortunately there is a huge amount of space left over in the 1024 byte superblock. - Ted