From: "J. Bruce Fields" Subject: Re: rfc: [patch] change attribute for ext3 Date: Wed, 13 Sep 2006 21:24:49 -0400 Message-ID: <20060914012449.GC22224@fieldses.org> References: <20060913164202.GA14838@openx1.frec.bull.fr> <20060913193130.GJ6441@schatzie.adilger.int> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexandre Ratchov , linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org Return-path: Received: from mail.fieldses.org ([66.93.2.214]:56739 "EHLO pickle.fieldses.org") by vger.kernel.org with ESMTP id S1751317AbWINBYw (ORCPT ); Wed, 13 Sep 2006 21:24:52 -0400 To: Andreas Dilger Content-Disposition: inline In-Reply-To: <20060913193130.GJ6441@schatzie.adilger.int> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, Sep 13, 2006 at 01:31:30PM -0600, Andreas Dilger wrote: > On Sep 13, 2006 18:42 +0200, Alexandre Ratchov wrote: > > The patch also adds a new ``st_change_attribute'' field in the stat > > structure, and modifies the stat(2) syscall accordingly. Currently the > > change is only visible on i386 and x86_64 archs. > > Is this really necessary for knfsd? Of course knfsd is completely in kernel, so it doesn't care about the userspace interface. But I think that a change attribute is potentially an *extremely* useful thing, and for more than just nfs servers. Lots of userspace programs also need to know whether a file has changed since they last examined it, and also suffer from the limitations of using ctime or mtime as an imperfect approximation to a real change attribute. But it would make sense to split the user space changes into a second patch and possibly apply it later. --b.