From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753888Ab3BNCsj (ORCPT ); Wed, 13 Feb 2013 21:48:39 -0500 Received: from fn.samba.org ([216.83.154.106]:38486 "EHLO mail.samba.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752275Ab3BNCsi (ORCPT ); Wed, 13 Feb 2013 21:48:38 -0500 Message-ID: <1360810114.1727.306.camel@jesse> Subject: Read support for fat_fallocate()? (was [v2] fat: editions to support fat_fallocate()) From: Andrew Bartlett To: Namjae Jeon Cc: hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org, Ravishankar N , Amit Sahrawat Date: Thu, 14 Feb 2013 13:48:34 +1100 References: <1350138661-2454-1-git-send-email-linkinjeon@gmail.com> Organization: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4 (3.4.4-2.fc17) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (apologies for the duplicate mail, I typo-ed the maintainers address) G'day, I've been looking into the patch "[v2] fat: editions to support fat_fallocate()" and I wonder if there is a way we can split this issue in two, so that we get at least some of the patch into the kernel. https://lkml.org/lkml/2012/10/13/75 https://patchwork.kernel.org/patch/1589161/ What I'm wanting to discuss (and perhaps implement, with you if possible) is splitting this patch into writing to existing pre-allocated files, and creating a new pre-allocation. If Windows does, as you claim, simply read preallocations as zero, and writes to them normally and without error, then Linux should do the same. Here of course I'm assuming that Windows is not preallocating, but instead simply trying to recover gracefully and safely from a simple 'file system corruption', where the sectors are allocated but not used. The bulk of this patch is implementing this transparent recovery, and it seem relatively harmless to include this into the kernel. Then vendors doing TV streaming, or in my case copies of large files onto Samba-mounted USB FAT devices, can add only the smaller patch to implement fallocate, at their own risk and fully knowing that it will be regarded as corrupt on Linux. If accepted read support will, over a period of years, trickle down to other Linux users, broadening the base that can still read these 'corrupt' drives, no matter the cause. I hope you agree that this is a practical way forward, and I look forward to working with you on this. Thanks, Andrew Bartlett -- Andrew Bartlett http://samba.org/~abartlet/ Authentication Developer, Samba Team http://samba.org