From: "J. Bruce Fields" Subject: Re: [PATCH] NFS: Change default behavior when "sec=" is not specified by user Date: Tue, 1 Sep 2009 14:50:11 -0400 Message-ID: <20090901185011.GC27726@fieldses.org> References: <20090901143012.3978.11441.stgit@matisse.1015granger.net> <20090901150545.GA22846@fieldses.org> <7C5C14D9-F315-4DF8-A2F4-C7F0981AC968@oracle.com> <20090901151830.GC22846@fieldses.org> <18678BB3-52C6-4376-BBD1-50B8947BAAC7@oracle.com> <20090901160914.GG22846@fieldses.org> <73E8EAAF-9164-4F78-A9D4-1CC86A6A6255@oracle.com> <20090901163846.GJ22846@fieldses.org> <4A9D690E.2050704@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Chuck Lever , trond.myklebust@fys.uio.no, linux-nfs@vger.kernel.org To: Peter Staubach Return-path: Received: from fieldses.org ([174.143.236.118]:49618 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715AbZIASuR (ORCPT ); Tue, 1 Sep 2009 14:50:17 -0400 In-Reply-To: <4A9D690E.2050704@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Sep 01, 2009 at 02:33:50PM -0400, Peter Staubach wrote: > Chuck Lever wrote: > > > > On Sep 1, 2009, at 12:38 PM, J. Bruce Fields wrote: > > > >> On Tue, Sep 01, 2009 at 12:29:30PM -0400, Chuck Lever wrote: > >>> On Sep 1, 2009, at 12:09 PM, J. Bruce Fields wrote: > >>>> And, sure, that'd be OK with me, and would probably be better than > >>>> adding another exception, so I'm OK with skipping #3. (We definitely > >>>> shouldn't omit #2, though.) > >>> > >>> Seems straightforward enough, but... Why are we doing this again? It > >>> still seems like non-standard behavior. Are we simply attempting to > >>> avoid the case where folks would get the "nobody" behavior unexpectedly > >>> because of a mountd bug, or is there more to it? > >> > >> That's all there is to it. As I said: > >> > >>>>>>>> 2. In the absence of sec=, we should probably *not* choose > >>>>>>>> AUTH_NULL. (All mountd's before 1.1.3 list AUTH_NULL first on > >>>>>>>> the returned list, so users with older servers may wonder why a > >>>>>>>> client upgrade is making files they create suddenly be owned by > >>>>>>>> nobody.) http://marc.info/?l=linux-nfs&m=125089022306281&w=2 > >> > >>> I'm just thinking of what the documenting comment might say, and perhaps > >>> some explanation added to nfs(5). > >> > >> "As a special case, to work around bugs in some older servers, the > >> client will never automatically negotiate auth_null; if auth_null is > >> desired, an explicit "sec=null" on the commandline is required." > >> > >> Or something like that. > > > > OK, one more corner case. > > > > What if the mount doesn't specify "sec=" and the only flavor in the > > server's auth list is AUTH_NULL? Seems like we should allow that one. > > > > Some servers will accept any flavor of incoming RPC security > and just use AUTH_NULL in this situation. It really shouldn't > matter what the client sends, as long as the server is just > going to map all requests to nobody/nobody anyway... OK, but let's not pile on more workarounds than we have to. I don't see any reason that we really need to do anything special for servers that are broken in *that* particular way.... --b.