From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756785Ab2JWHT1 (ORCPT ); Tue, 23 Oct 2012 03:19:27 -0400 Received: from mail.parknet.co.jp ([210.171.160.6]:53765 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756770Ab2JWHTX (ORCPT ); Tue, 23 Oct 2012 03:19:23 -0400 From: OGAWA Hirofumi To: Namjae Jeon Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Ravishankar N , Amit Sahrawat , linux-fsdevel Subject: Re: [PATCH v2] fat: editions to support fat_fallocate() References: <1350138661-2454-1-git-send-email-linkinjeon@gmail.com> <87lif958lb.fsf@devron.myhome.or.jp> <87txtu206u.fsf@devron.myhome.or.jp> <878vazl6tw.fsf@devron.myhome.or.jp> Date: Tue, 23 Oct 2012 16:19:14 +0900 In-Reply-To: (Namjae Jeon's message of "Tue, 23 Oct 2012 00:10:03 +0900") Message-ID: <877gqhk64t.fsf@devron.myhome.or.jp> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.2.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Namjae Jeon writes: >> Does this break the linux fat driver doesn't know about this >> fallocate()? If so, it sounds like to be easy to break existent >> drivers. > Yes, it will break linux drivers without fallocate support. When we > try to write to fallocated file using old drivers, it will cause write > error and make FS read-only. > When fallocate was implemented in other filesystem, maybe,, was there > similar issue and concern ? I guess it is not similar. Because other FS can change the spec (e.g. it can be possible to use feature compat flag for it). -- OGAWA Hirofumi