From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753986Ab1ACK0r (ORCPT ); Mon, 3 Jan 2011 05:26:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:17726 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482Ab1ACK0p (ORCPT ); Mon, 3 Jan 2011 05:26:45 -0500 Subject: Re: [PATCH] Update atime from future. From: Steven Whitehouse To: yangsheng Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org In-Reply-To: <1293631121-12667-1-git-send-email-sickamd@gmail.com> References: <1293631121-12667-1-git-send-email-sickamd@gmail.com> Content-Type: text/plain; charset="UTF-8" Organization: Red Hat UK Ltd Date: Mon, 03 Jan 2011 10:27:48 +0000 Message-ID: <1294050468.2429.2.camel@dolmen> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Wed, 2010-12-29 at 21:58 +0800, yangsheng wrote: > Signed-off-by: sickamd@gmail.com > --- > fs/inode.c | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index da85e56..6c8effd 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1469,7 +1469,13 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, > return 1; > > /* > - * Is the previous atime value older than a day? If yes, > + * Is the previous atime value in future? If yes, > + * update atime: > + */ > + if ((long)(now.tv_sec - inode->i_atime.tv_sec) < 0) > + return 1; > + /* > + * Is the previous atime value old than a day? If yes, > * update atime: > */ > if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60) I don't think this is a good plan for cluster filesystems, since if the times on the nodes are not exactly synchronised (we do highly recommend people run ntp or similar) then this might lead to excessive atime updating. The current behaviour is to ignore atimes which are in the future for exactly this reason, Steve.