Return-Path: Received: from Mycroft.westnet.com ([216.187.52.7]:36312 "EHLO mycroft.westnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555Ab0GVToN (ORCPT ); Thu, 22 Jul 2010 15:44:13 -0400 Content-Type: text/plain; charset=us-ascii Message-ID: <19528.39283.469638.12844@stoffel.org> Date: Thu, 22 Jul 2010 15:18:11 -0400 From: "John Stoffel" To: Jeremy Allison Cc: Trond Myklebust , Linus Torvalds , 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 Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] In-Reply-To: <20100722180204.GA32008@samba1> 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> <1279817930.3621.14.camel@heimdal.trondhjem.org> <20100722180204.GA32008@samba1> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 >>>>> "Jeremy" == Jeremy Allison writes: Jeremy> On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote: >> >> That would make it impossible to export the filesystem with NFSv2 and >> v3. They do rely on ctime checking for certain operations (e.g. deciding >> when to invalidate access and acl caches). NFSv4 needs this too if the >> filesystem has no dedicated change attribute. >> >> Still, I suppose the market for exporting the same filesystem with both >> NFS and Samba is limited... Jeremy> Ask NetApp about that :-). They have built a rather large Jeremy> business on just that fact :-). And it does work, as long as you also go with either unix or windows semantics for the security and permissions bits. If you try to use the mixed-mode, you're in for a world of hurt. Oh yeah, Netapp still uses dump/restore for it's backups. :] Though whether it's still dependent on the optimization of ctime being used to know whether to just dump the inode only or not, I can't say. John