From: Greg Freemyer Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] Date: Thu, 22 Jul 2010 14:45:07 -0400 Message-ID: References: <20100715021709.5544.64506.stgit@warthog.procyon.org.uk> <20100715021712.5544.44845.stgit@warthog.procyon.org.uk> <30448.1279800887@redhat.com> <20100722162712.GB10352@jeremy-laptop> <4C488C41.60002@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Linus Torvalds , Jan Engelhardt , Jeremy Allison , Volker.Lendecke@sernet.de, David Howells , linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org To: Benny Halevy Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:54970 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756634Ab0GVSpJ (ORCPT ); Thu, 22 Jul 2010 14:45:09 -0400 In-Reply-To: <4C488C41.60002@panasas.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jul 22, 2010 at 2:21 PM, Benny Halevy wrote: > On Jul. 22, 2010, 20:24 +0300, Linus Torvalds wrote: >> On Thu, Jul 22, 2010 at 10:03 AM, Jan Engelhardt wrote: >>> >>> I beg to differ. ctime is not completely useless. It reflects changes on >>> the inode for when you don't you change the content. >> >> Uh. Yes. Except that why is file metadata really different from file >> data? Most people really don't care. And a lot of people have asked >> for creation dates - and I seriously doubt that Windows people >> complain a lot about the fact that there you have mtime for metadata >> changes too. >> >> The point being that Unix ctime semantics certainly have well-defined >> semantics, but they are in no way "better" than having a real creation >> time, and are often worse. > > Yeah, having create time would be important. > That said, having a non user-settable modify timestamp is crucial > for quickly determining whether a file has changed. How would "cp --archive" and a host of backup/restore tools work without user-settable modify timestamps? Or are you proposing another timestamp? I do computer forensics, I like timestamps, but enough is enough. Greg