From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261386AbVELTVb (ORCPT ); Thu, 12 May 2005 15:21:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261421AbVELTVb (ORCPT ); Thu, 12 May 2005 15:21:31 -0400 Received: from mail.ccur.com ([208.248.32.212]:38981 "EHLO flmx.iccur.com") by vger.kernel.org with ESMTP id S261386AbVELTV1 (ORCPT ); Thu, 12 May 2005 15:21:27 -0400 Subject: NFS: msync required for data writes to server? From: Linda Dunaphant Reply-To: linda.dunaphant@ccur.com To: trond.myklebust@fys.uio.no Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: CCUR Message-Id: <1115925686.6319.3.camel@lindad> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-1) Date: Thu, 12 May 2005 15:21:26 -0400 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 12 May 2005 19:21:27.0268 (UTC) FILETIME=[CB18FA40:01C55727] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Trond, On our 2.6.9 based systems, data written using mmap(MAP_SHARED) on a NFS client is *never* being pushed out to the server if an explicit msync call is not issued before the munmap. On 11/12/04, there was a message thread concerning NFS corruption when using mmap/munmap: http://marc.theaimsgroup.com/?l=linux-nfs&m=110028817508318&w=2 In this thread you stated: mmap() offers absolutely NO guarantees that the file will be synced to disk on close. Use msync(MS_SYNC) if you want such a guarantee. Are you saying that the data will *never* be written to the server? Could you please clarify your position on this further? Thanks! Linda