From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932320AbVHHWdG (ORCPT ); Mon, 8 Aug 2005 18:33:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932301AbVHHWcr (ORCPT ); Mon, 8 Aug 2005 18:32:47 -0400 Received: from mail-in-03.arcor-online.net ([151.189.21.43]:50086 "EHLO mail-in-03.arcor-online.net") by vger.kernel.org with ESMTP id S932320AbVHHWc3 (ORCPT ); Mon, 8 Aug 2005 18:32:29 -0400 From: Bodo Eggert Subject: Re: [PATCH] Posix file attribute support on VFAT To: Hiroyuki Machida , hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org Reply-To: 7eggert@gmx.de Date: Tue, 09 Aug 2005 00:32:18 +0200 References: <4zfoZ-5u4-9@gated-at.bofh.it> User-Agent: KNode/0.7.2 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: harvested.in.lkml@posting.7eggert.dyndns.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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? > - 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. -- Ich danke GMX dafür, die Verwendung meiner Adressen mittels per SPF verbreiteten Lügen zu sabotieren.