Return-Path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:44078 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759399Ab0GVRd1 convert rfc822-to-8bit (ORCPT ); Thu, 22 Jul 2010 13:33:27 -0400 In-Reply-To: <20100722171224.GA8630@merit.edu> 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> <20100722171224.GA8630@merit.edu> From: Linus Torvalds Date: Thu, 22 Jul 2010 10:32:31 -0700 Message-ID: Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] To: Jim Rees Cc: Jeremy Allison , Volker.Lendecke@sernet.de, David Howells , Jan Engelhardt , 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 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Thu, Jul 22, 2010 at 10:12 AM, Jim Rees wrote: > > I believe it was done that way so "dump" could backup just the inode and not > the data if only the inode had changed. ?Full history here: > > http://blog.plover.com/Unix/ctime.html Yes, the dump reasoning makes sense, and that history also shows that originally chmod just changed mtime (since that's the _sane_ thing to do). So if it wasn't for dump - that nobody uses any more and that was considered a hack even back when and never supported things like xattrs etc - unix probably wouldn't have a ctime at all (or would have implemented a "creation time" because people would have asked for it). So I'm sure there are reasons for ctime. That just doesn't mean that it's really "good", the same way there were reasons to name "creat()" without the "e". Linus