Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750821AbVKHETs (ORCPT ); Mon, 7 Nov 2005 23:19:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750877AbVKHETr (ORCPT ); Mon, 7 Nov 2005 23:19:47 -0500 Received: from smtp.osdl.org ([65.172.181.4]:4766 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750821AbVKHETq (ORCPT ); Mon, 7 Nov 2005 23:19:46 -0500 Date: Mon, 7 Nov 2005 20:19:34 -0800 From: Andrew Morton To: OGAWA Hirofumi Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 7/6] fat: Support a truncate() for expanding size Message-Id: <20051107201934.4c01a472.akpm@osdl.org> In-Reply-To: <87ek5rx1ur.fsf@devron.myhome.or.jp> References: <87hdaotlci.fsf@devron.myhome.or.jp> <87d5lctl5y.fsf@devron.myhome.or.jp> <878xw0tl3r.fsf_-_@devron.myhome.or.jp> <874q6otl0q.fsf_-_@devron.myhome.or.jp> <87zmogs6cs.fsf_-_@devron.myhome.or.jp> <87vez4s6b7.fsf_-_@devron.myhome.or.jp> <87r79ss658.fsf_-_@devron.myhome.or.jp> <20051107170626.4d08e8d6.akpm@osdl.org> <87ek5rx1ur.fsf@devron.myhome.or.jp> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2106 Lines: 66 OGAWA Hirofumi wrote: > > Andrew Morton writes: > > > OGAWA Hirofumi wrote: > >> > >> +static int fat_cont_expand(struct inode *inode, loff_t size) > > > > Is it not possible to extend generic_cont_expand() so that fatfs can use it? > > The generic_cont_expand() is too generic. But can it be fixed?? > If "size" is block boundary, generic_cont_expand() expands the > ->i_size to "size + 1", after it, the caller of it will truncate to > "size" by vmtruncate(). Something like this? --- devel/fs/buffer.c~a 2005-11-07 20:17:49.000000000 -0800 +++ devel-akpm/fs/buffer.c 2005-11-07 20:18:59.000000000 -0800 @@ -2160,7 +2160,7 @@ int block_read_full_page(struct page *pa * truncates. Uses prepare/commit_write to allow the filesystem to * deal with the hole. */ -int generic_cont_expand(struct inode *inode, loff_t size) +static int __generic_cont_expand(struct inode *inode, loff_t size, int dont_do_that) { struct address_space *mapping = inode->i_mapping; struct page *page; @@ -2182,9 +2182,8 @@ int generic_cont_expand(struct inode *in ** skip the prepare. make sure we never send an offset for the start ** of a block */ - if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { + if (!dont_do_that && (offset & (inode->i_sb->s_blocksize - 1)) == 0) offset++; - } index = size >> PAGE_CACHE_SHIFT; err = -ENOMEM; page = grab_cache_page(mapping, index); @@ -2202,6 +2201,16 @@ out: return err; } +int generic_cont_expand(struct inode *inode, loff_t size) +{ + return __generic_cont_expand(inode, size, 0); +} + +int generic_cont_expand_dont_do_that(struct inode *inode, loff_t size) +{ + return __generic_cont_expand(inode, size, 1); +} + /* * For moronic filesystems that do not allow holes in file. * We may have to extend the file. _ - 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/