Return-Path: Received: from rcsinet10.oracle.com ([148.87.113.121]:18011 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932357Ab1COQyq convert rfc822-to-8bit (ORCPT ); Tue, 15 Mar 2011 12:54:46 -0400 Subject: Re: [PATCH] SUNRPC: svc_register error overwritten in next iteration Content-Type: text/plain; charset=us-ascii From: Chuck Lever In-Reply-To: <20110315161301.GA32635@fieldses.org> Date: Tue, 15 Mar 2011 12:54:01 -0400 Cc: roel , Neil Brown , linux-nfs@vger.kernel.org, Andrew Morton , LKML Message-Id: References: <4D7B74C7.7060506@gmail.com> <20110314223645.GL25442@fieldses.org> <13D041DB-A26D-4EC1-A585-7DBA266CF18A@oracle.com> <20110315161301.GA32635@fieldses.org> To: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mar 15, 2011, at 12:13 PM, J. Bruce Fields wrote: > On Tue, Mar 15, 2011 at 11:43:32AM -0400, Chuck Lever wrote: >> >> On Mar 14, 2011, at 6:36 PM, J. Bruce Fields wrote: >> >>> On Sat, Mar 12, 2011 at 02:27:35PM +0100, roel wrote: >>>> The break is in the inner loop, the svc_register() error is overwritten >>>> in the next iteration. Only the error in the last iteration is returned. >>>> >>>> Signed-off-by: Roel Kluin >>>> --- >>>> net/sunrpc/svc.c | 2 ++ >>>> 1 files changed, 2 insertions(+), 0 deletions(-) >>>> >>>> Is this needed? >>>> >>>> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c >>>> index 08e05a8..5fd08c0 100644 >>>> --- a/net/sunrpc/svc.c >>>> +++ b/net/sunrpc/svc.c >>>> @@ -889,6 +889,8 @@ int svc_register(const struct svc_serv *serv, const int family, >>>> if (error < 0) >>>> break; >>> >>> May as well just "goto out" or "return error" here? >>> >>> But: aren't we missing some cleanup? If we succesfully register one >>> program then fail at a second one, don't we need to unregister the >>> first? >> >> Right. I don't understand what is the intended effect here (of the original code): Best effort registration, or "all or none"? > > The current code was failing iff the last registration returns an error. > We list the nfs program before the acl program in this list, so nfsd > registration was failing iff the acl program failed, which makes no > sense whatsoever. > > I think "all or none" would be cleanest. > > If people start complaining that they don't want to run rpcbind/portmap > then we could give them some way of requesting that instead of just > depending on allowing the registration to fail. I thought vs_hidden was set for NFSACL... but maybe I was wrong about that. > For cleanup, we can just unregister everything, right? (No harm in > possibly unregistering something who's registration just failed?) Yes. As a simple hard-headed approach, probably you should walk the passed-in sv_program list again and unregister each item in the list. The downside to this is if the upcall is taking a long time (for instance, if networking is not available). It would double the amount of time for svc_register() to return a failure. However, be prepared: I bet such a change could expose bugs in the NFSD start up stack. :-( Maybe it deserves some soak-time in linux-next. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com