Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx2.netapp.com ([216.240.18.37]:40748 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753223Ab1JFDo5 convert rfc822-to-8bit (ORCPT ); Wed, 5 Oct 2011 23:44:57 -0400 Subject: Re: [nfsv4] back channel flags, CREATE_SESSION, BIND_CONN_TO_SESSION From: Trond Myklebust To: "Matt W. Benjamin" Cc: nfsv4 , linux-nfs , nfs-ganesha-devel Date: Wed, 05 Oct 2011 23:44:56 -0400 In-Reply-To: <1317871693.14305.5.camel@lade.trondhjem.org> References: <800236997.158.1317856908314.JavaMail.root@thunderbeast.private.linuxbox.com> <1317871693.14305.5.camel@lade.trondhjem.org> Content-Type: text/plain; charset="UTF-8" Message-ID: <1317872696.14918.1.camel@lade.trondhjem.org> Mime-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, 2011-10-05 at 23:28 -0400, Trond Myklebust wrote: > On Wed, 2011-10-05 at 19:21 -0400, Matt W. Benjamin wrote: > > Currently, the Linux and I believe also the CITI Windows client always propose channels in both directions. The Linux mainline Linux client doesn't know how to BIND_CONN_TO_SESSION, so trivially it won't negotiate any back channel if a server didn't agree to both directions today, either. I've experimentally implemented a "fallback" model in a Linux client and (partly in a) Ganesha server. I'd appreciate any feedback on the idea. > > Yep. As I said, why should we bother adding support for servers that > don't? I can function perfectly well without pNFS support or delegation > support in such a case. Performance will suck, but why do I care? To put it in more basic terms: what you are proposing will add development costs to the client and and an extra code burden to maintain long term. So what is in it for me? -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com