Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932311AbWJVJLq (ORCPT ); Sun, 22 Oct 2006 05:11:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932314AbWJVJLp (ORCPT ); Sun, 22 Oct 2006 05:11:45 -0400 Received: from mail.parknet.jp ([210.171.160.80]:45572 "EHLO parknet.jp") by vger.kernel.org with ESMTP id S932311AbWJVJLo (ORCPT ); Sun, 22 Oct 2006 05:11:44 -0400 X-AuthUser: hirofumi@parknet.jp To: Nick Piggin Cc: Andrew Morton , Damien Wyart , linux-kernel Subject: Re: 2.6.19-rc2-mm2 : empty files on vfat file system References: <20061021104454.GA1996@localhost.localdomain> <87lkn9x0ly.fsf@duaron.myhome.or.jp> <20061021173849.GA1999@localhost.localdomain> <20061021131932.09801b4a.akpm@osdl.org> <873b9htne9.fsf@duaron.myhome.or.jp> <20061022015028.GB17694@wotan.suse.de> From: OGAWA Hirofumi Date: Sun, 22 Oct 2006 18:11:36 +0900 In-Reply-To: <20061022015028.GB17694@wotan.suse.de> (Nick Piggin's message of "Sun\, 22 Oct 2006 03\:50\:28 +0200") Message-ID: <87lkn8sojb.fsf@duaron.myhome.or.jp> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1457 Lines: 37 Nick Piggin writes: > On Sun, Oct 22, 2006 at 05:38:38AM +0900, OGAWA Hirofumi wrote: >> >> As I said in this thread, generic_cont_expand() uses "to == from". >> Should we fix generic_cont_expand() instead? I don't know the >> background of this patch. > > OK I have to write an RFC for various fs developers, so I'll be sure > to include you. > > We want to be able to pass in a short (possibly zero) commit_write > length if the page data can not be fully copied. Thanks. So, if the range is zero, what should fs driver do? > generic_cont_expand seems to be using that as a shorthand for > "update the i_size but don't mark anything uptdoate"? If so, I think > it would be nice to fix it. Why does it even need to go through the > prepare/commit? It's not only for updating ->i_size. __generic_cont_expand() is used for expanding ->i_size by trucate(2). In FAT case, it needs to fill the hole by zero and dirty it before write new ->i_size. The ->prepare_write() does it, and ->commit_write() writes ->i_size and dirty inode in __generic_cont_expand(). Anyway, if it's required, maybe we would be able to change __generic_cont_expand(). -- OGAWA Hirofumi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/