From: Mingming Cao Subject: Re: [PATCH 1/5] fallocate() implementation in i86, x86_64 and powerpc Date: Wed, 09 May 2007 10:07:25 -0700 Message-ID: <1178730446.3815.8.camel@dyn9047017103.beaverton.ibm.com> References: <20070329115126.GB7374@amitarora.in.ibm.com> <20070329101010.7a2b8783.akpm@linux-foundation.org> <20070330071417.GI355@devserv.devel.redhat.com> <20070417125514.GA7574@amitarora.in.ibm.com> <20070418130600.GW5967@schatzie.adilger.int> <20070420135146.GA21352@amitarora.in.ibm.com> <20070420145918.GY355@devserv.devel.redhat.com> <20070424121632.GA10136@amitarora.in.ibm.com> <20070426175056.GA25321@amitarora.in.ibm.com> <20070426180332.GA7209@amitarora.in.ibm.com> <20070509160102.GA30745@amitarora.in.ibm.com> Reply-To: cmm@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: torvalds@osdl.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, xfs@oss.sgi.com, suparna@in.ibm.com To: "Amit K. Arora" Return-path: Received: from e34.co.us.ibm.com ([32.97.110.152]:39029 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755011AbXEIRHa (ORCPT ); Wed, 9 May 2007 13:07:30 -0400 In-Reply-To: <20070509160102.GA30745@amitarora.in.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, 2007-05-09 at 21:31 +0530, Amit K. Arora wrote: > I have the updated patches ready which take care of Andrew's comments. > Will run some tests and post them soon. > > But, before submitting these patches, I think it will be better to finalize > on certain things which might be worth some discussion here: > > 1) Should the file size change when preallocation is done beyond EOF ? > - Andreas and Chris Wedgwood are in favor of not changing the > file size in this case. I also tend to agree with them. Does anyone > has an argument in favor of changing the filesize ? > If not, I will remove the code which changes the filesize, before I > resubmit the concerned ext4 patch. > If we chose not to update the file size beyong EOF, then for filesystem without fallocate() support (ext2,3 currently), posix_fallocate() will follow the hard way(zero-out) to do preallocation. Then we will get different behavior on filesystems w/o fallocate() support. It make sense to be consistent, IMO. My point of view, preallocation is just a efficient way to allocating blocks for files without zero-out, other than this, the new behavior should be consistent with the old way: file size update,mtime/ctime, ENOSPC etc. Mingming