Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751980AbXB1VJi (ORCPT ); Wed, 28 Feb 2007 16:09:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751973AbXB1VJi (ORCPT ); Wed, 28 Feb 2007 16:09:38 -0500 Received: from mx1.redhat.com ([66.187.233.31]:33270 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbXB1VJh (ORCPT ); Wed, 28 Feb 2007 16:09:37 -0500 Message-ID: <45E5EF89.4050707@redhat.com> Date: Wed, 28 Feb 2007 16:09:29 -0500 From: Peter Staubach User-Agent: Thunderbird 1.5.0.9 (X11/20061215) MIME-Version: 1.0 To: Miklos Szeredi CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [patch 01/22] update ctime and mtime for mmaped write References: <20070227231442.627972152@szeredi.hu> <20070227231544.519463073@szeredi.hu> <45E58EB8.6030502@redhat.com> <45E5BA2E.8060003@redhat.com> <45E5DF8E.80109@redhat.com> 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 Content-Length: 970 Lines: 23 Miklos Szeredi wrote: >> What happens if the application overwrites what it had written some >> time later? Nothing. The page is already read-write, the pte dirty, >> so even though the file was clearly modified, there's absolutely no >> way in which this can be used to force an update to the timestamp. >> > > Which, I realize now, actually means, that the patch is wrong. Msync > will have to write protect the page table entries, so that later > dirtyings may have an effect on the timestamp. I thought that PeterZ's changes were to write-protect the page after cleaning it so that future modifications could be detected and tracked accordingly? Does the right thing not happen already? Thanx... ps - 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/