From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263743AbUESFHa (ORCPT ); Wed, 19 May 2004 01:07:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263790AbUESFHa (ORCPT ); Wed, 19 May 2004 01:07:30 -0400 Received: from ASYNC13-9.NET.CS.CMU.EDU ([128.2.188.77]:60290 "EHLO mentor.odyssey.cs.cmu.edu") by vger.kernel.org with ESMTP id S263743AbUESFH3 (ORCPT ); Wed, 19 May 2004 01:07:29 -0400 Date: Wed, 19 May 2004 01:08:01 -0400 To: Andrea Arcangeli Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: invalidate_inode_pages2 Message-ID: <20040519050801.GA9605@mentor.odyssey.cs.cmu.edu> Mail-Followup-To: Andrea Arcangeli , Andrew Morton , linux-kernel@vger.kernel.org References: <20040519001520.GO3044@dualathlon.random> <20040518172718.773d32c1.akpm@osdl.org> <20040519005106.GP3044@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040519005106.GP3044@dualathlon.random> User-Agent: Mutt/1.5.5.1+cvs20040105i From: Jan Harkes Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 19, 2004 at 02:51:06AM +0200, Andrea Arcangeli wrote: > On Tue, May 18, 2004 at 05:27:18PM -0700, Andrew Morton wrote: > > Andrea Arcangeli wrote: > > > > > > Something broke in invalidate_inode_pages2 between 2.4 and 2.6, this > > > causes malfunctions with mapped pages in 2.6. > > > > What is the malfunction? > > From Olaf Kirch > > - single application on NFS client opens file and maps it. > No-one else has this file open. File contains "zappa\n", > and the test app stats it once a second and reports size and > contents. > len=6, data=7a 61 70 70 61 0a > - on the NFS server, I do "echo frobnorz > file" > - after a while, the test app on the client reports > len=10, data=7a 61 70 70 61 0a I'm mostly just curious, what exactly happens when a second process opens and mmaps the file at this point? Will it also see the new length with the old data, or will that invalidate the mapping and pull the new data off of the server? Also what happens if the process had a shared mapping and dirtied the page (f.i. it wrote a byte to to offset 0) but the update hasn't yet been written back, will it end up committing the (stale) data from the local copy of the page but with the updated length=10 back to the server? Jan