From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932386AbVHIAaf (ORCPT ); Mon, 8 Aug 2005 20:30:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932389AbVHIAaf (ORCPT ); Mon, 8 Aug 2005 20:30:35 -0400 Received: from NS6.Sony.CO.JP ([137.153.0.32]:24200 "EHLO ns6.sony.co.jp") by vger.kernel.org with ESMTP id S932386AbVHIAae (ORCPT ); Mon, 8 Aug 2005 20:30:34 -0400 Message-ID: <42F7F998.7080400@sm.sony.co.jp> Date: Tue, 09 Aug 2005 09:32:24 +0900 From: "Machida, Hiroyuki" User-Agent: Mozilla Thunderbird 1.0.2 (Windows/20050317) X-Accept-Language: ja, en-us, en MIME-Version: 1.0 To: 7eggert@gmx.de CC: hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Posix file attribute support on VFAT References: <4zfoZ-5u4-9@gated-at.bofh.it> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bodo Eggert wrote: > Hiroyuki Machida wrote: > > >>For newly created and/or modified files/dirs, system can utilize >>full posix attributes, because memory resident inode storage can >>hold those. After umount-mount cycle, system may lose some >>attributes to preserve VFAT format. > > > Inodes may be reclaimed, therefore you might also lose some attributes at > runtime. For your users, that will look like a heisenbug. A similar bug > has been reported for procfs. Is your implementation affected? Yes. Thank you, pointed it out. So I need to select 1) restric attribute even in mamory or 2) pinn inode in memory during mount (I think it's not good idea) I'll revise the patch with 1). >>- Special file >> To distinguish special files, look if this fat dir entry >> has ATTR_SYS, first. If it has ATTR_SYS, then check >> 1st. LSB bit in ctime_cs, refered as "special file flag". >> If set, this file is created under VFAT with "posix_attr". >> Look up TYPE field to decide special file type. >> This spcial file detection mothod has some flaw to make >> potential confusion. E.g. some system file created under >> dos/win may be treated as special file. However in most case, >> user don't create system file under dos/win. > > > You can add additional magic, e.g.: nodes must be empty, except for symlinks > which must be not larger than 4KB (current PATH_MAX?). This will get rid > of io.sys, logo.sys etc.\. If you want to be really sure, prepend a magic > code to the on-disk representation of symlinks. Please confirm my understanding. You sugessted that symlink should not have ATTR_SYS, to prevent some over 4KB files created in DOS/WIN to be treated as symlinks? -- Hiroyuki Machida machida@sm.sony.co.jp SSW Dept. HENC, Sony Corp.