Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752963Ab0GVQG2 (ORCPT ); Thu, 22 Jul 2010 12:06:28 -0400 Received: from mail-iw0-f174.google.com ([209.85.214.174]:59064 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758Ab0GVQGY convert rfc822-to-8bit (ORCPT ); Thu, 22 Jul 2010 12:06:24 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=PSCDcdbA73+xZjwpMSPRwjsQyY28AZyNuH70WIXEpRGSuB6cCy31rf+NbFJPICDaQa BBdtb2wo3r5kyPRsD+zX6YEk1gWp0t2DrPEzMsDXxVByg+LVQXN9bcrEyOR8tRPAZjfK 2cTGnrbgEc+sBW/YVb0caCaLXrYiZ8W9TRows= MIME-Version: 1.0 In-Reply-To: References: <20100715021709.5544.64506.stgit@warthog.procyon.org.uk> <20100715021712.5544.44845.stgit@warthog.procyon.org.uk> <30448.1279800887@redhat.com> Date: Thu, 22 Jul 2010 12:06:22 -0400 Message-ID: Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] From: Greg Freemyer To: Linus Torvalds Cc: 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 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2180 Lines: 59 On Thu, Jul 22, 2010 at 11:47 AM, Linus Torvalds wrote: > On Thu, Jul 22, 2010 at 8:36 AM, Volker Lendecke > wrote: >> >> The nice thing about this is also that if this is supposed >> to be fully usable for Windows clients, the birthtime needs >> to be changeable. That's what NTFS semantics gives you, thus >> Windows clients tend to require it. > > Ok. So it's not really a creation date, exactly the same way ctime > isn't at all a creation date. > > And maybe that actually hints at a better solution: maybe a better > model is to create a new per-thread flag that says "do ctime updates > the way windows does them". > > So instead of adding another "btime" - which isn't actually what even > windows does - just admit that the _real_ issue is that Unix and > Windows semantics are different for the pre-existing "ctime". > > The fact is, windows has "access time", "modification time" and > "creation time" _exactly_ like UNIX. It's just that the ctime has > slightly different semantics in windows vs unix. So quite frankly, > it's totally insane to introduce a "birthtime", when that isn't even > what windows wants, just because people cannot face the actual real > difference. > > Tell me why we shouldn't just do this right? > > ? ? ? ? ? ? ? ?Linus I haven't been keeping up with this thread, but I believe NTFS has a number of timestamps, not just 3. This blog post references 8 in the left hand column. The 4 standard (most common) ones are: File last access File last modified File created MFT last modified My understanding is that "MFT last modified" has semantics very similar to Linux ctime. But there is not a generic equivalent to NTFS created. Thus if trying to have the Linux kernel match NTFS semantics for the benefit of Samba is the goal, it seems a new field should be preferred instead of having linux ctime try to do different jobs. Greg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/