From: Zheng Liu Subject: Re: [PATCH 5/5] libext2fs: avoid 32-bit overflow in ext2fs_initialize with a 512M cluster size Date: Wed, 16 Jan 2013 09:49:14 +0800 Message-ID: <20130116014914.GA20060@gmail.com> References: <20130114211014.GA22642@thunk.org> <1358210232-30578-1-git-send-email-tytso@mit.edu> <1358210232-30578-5-git-send-email-tytso@mit.edu> <20130115153331.GE19209@gmail.com> <20130115191030.GC17719@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List To: Theodore Ts'o Return-path: Received: from mail-pb0-f47.google.com ([209.85.160.47]:63107 "EHLO mail-pb0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756394Ab3APBf1 (ORCPT ); Tue, 15 Jan 2013 20:35:27 -0500 Received: by mail-pb0-f47.google.com with SMTP id wz17so397688pbc.20 for ; Tue, 15 Jan 2013 17:35:27 -0800 (PST) Content-Disposition: inline In-Reply-To: <20130115191030.GC17719@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jan 15, 2013 at 02:10:30PM -0500, Theodore Ts'o wrote: > On Tue, Jan 15, 2013 at 11:33:31PM +0800, Zheng Liu wrote: > > > > FWIW, I wonder why we need to add such complex logical to handle a > > corner case. I guess no one wants to use a 512MB cluster. So changing > > max cluster size from 512MB to 256MB is very simple and straightfoward. > > I agree that it seems very unlikely that there would be much interest > in using a 512MB cluster. However, we would still need to do the > check in the case of a 16k block size (on an PowerPC or Itanium > system) at a 256MB or 128MB cluster. So part of this check would be > needed anyway. Yeah, I see. Thanks for the explanation. Regards, - Zheng