Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:48002 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840Ab3KKTEI (ORCPT ); Mon, 11 Nov 2013 14:04:08 -0500 Message-ID: <52812A63.3000609@RedHat.com> Date: Mon, 11 Nov 2013 14:05:07 -0500 From: Steve Dickson MIME-Version: 1.0 To: "Myklebust, Trond" CC: Linux NFS Mailing List Subject: Re: [PATCH] Adding the nfs4_secure_mounts bool References: <1384037221-7224-1-git-send-email-steved@redhat.com> <52811CBB.3070204@RedHat.com> <607B1346-570D-4CD6-8018-6F9C0A2B5318@netapp.com> <52812539.8030805@RedHat.com> <80321082-AFEF-48DF-A70D-6577974F8F07@netapp.com> In-Reply-To: <80321082-AFEF-48DF-A70D-6577974F8F07@netapp.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 11/11/13 13:53, Myklebust, Trond wrote: > > On Nov 11, 2013, at 13:43, Steve Dickson wrote: > >> >> >> On 11/11/13 13:25, Myklebust, Trond wrote: >>> >>> On Nov 11, 2013, at 13:06, Steve Dickson wrote: >>> >>>> >>>> >>>> On 09/11/13 18:12, Myklebust, Trond wrote: >>>>> One alternative to the above scheme, which I believe that I?ve >>>>> suggested before, is to have a permanent entry in rpc_pipefs >>>>> that rpc.gssd can open and that the kernel can use to detect >>>>> that it is running. If we make it /var/lib/nfs/rpc_pipefs/gssd/clnt00/gssd, >>>>> then AFAICS we don?t need to change nfs-utils at all, since all newer >>>>> versions of rpc.gssd will try to open for read anything of the form >>>>> /var/lib/nfs/rpc_pipefs/*/clntXX/gssd... >>>> >>>> After further review I am going going have to disagree with you on this. >>>> Since all the context is cached on the initial mount the kernel >>> >>> What context? >> The krb5 blob that the kernel is call up to rpc.gssd to get.. Maybe >> I'm using the wrong terminology??? > > That?s only the machine cred. User credentials get allocated and freed all the time. > > When the server reboots, then all GSS contexts need to be re-established, > which can be a lot of call_usermodehelper() upcalls; that?s one of the > reasons why we decided in favour of a gssd daemon in the first place. Just curious... Why is the call_usermodehelper() upcalls more expensive than the rpc_pipefs upcalls? steved.