From: Steven Whitehouse Subject: Re: [PATCH] Update atime from future. Date: Mon, 03 Jan 2011 10:27:48 +0000 Message-ID: <1294050468.2429.2.camel@dolmen> References: <1293631121-12667-1-git-send-email-sickamd@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org To: yangsheng Return-path: In-Reply-To: <1293631121-12667-1-git-send-email-sickamd@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.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.