From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932803AbWF1NmI (ORCPT ); Wed, 28 Jun 2006 09:42:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932805AbWF1NmH (ORCPT ); Wed, 28 Jun 2006 09:42:07 -0400 Received: from yzordderrex.netnoteinc.com ([212.17.35.167]:37853 "EHLO yzordderrex.lincor.com") by vger.kernel.org with ESMTP id S932803AbWF1NmG (ORCPT ); Wed, 28 Jun 2006 09:42:06 -0400 Message-ID: <44A28646.4020408@draigBrady.com> Date: Wed, 28 Jun 2006 14:38:14 +0100 From: =?ISO-8859-1?Q?P=E1draig_Brady?= User-Agent: Mozilla Thunderbird 1.0.8 (X11/20060502) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Erik Paulson CC: linux-kernel@vger.kernel.org Subject: Re: file changes without updating mtime References: <20060627181010.GE25040@cobalt.cs.wisc.edu> In-Reply-To: <20060627181010.GE25040@cobalt.cs.wisc.edu> X-Enigmail-Version: 0.92.1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Perhaps you could create a filesystem wrapper module or Linux Security module or equivalent to intercept write/truncate etc. to invalidate an extended attribute containing a checksum. This extended attribute could be updated from userspace periodically, and your userspace program would compare those checksums. That would be generally useful. For example rsync could use it to very quickly determine if it needed to sync file contents. See also http://lkml.org/lkml/2006/5/17/138 Note also files mounted loopback and modified don't have their mtime updated either. Perhaps the patch referenced above addresses that? Pádraig.