Re: [PATCH] SUNRPC: svc_register error overwritten in next iteration

From: "J. Bruce Fields" <bfields@fieldses.org>
To: Chuck Lever <chuck.lever@oracle.com>
Cc: roel <roel.kluin@gmail.com>, Neil Brown <neilb@suse.de>,
	linux-nfs@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] SUNRPC: svc_register error overwritten in next iteration
Date: Tue, 15 Mar 2011 17:34:06 -0400	[thread overview]
Message-ID: <20110315213406.GB2292@fieldses.org> (raw)
In-Reply-To: <20110315165739.GB32635@fieldses.org>

On Tue, Mar 15, 2011 at 12:57:39PM -0400, J. Bruce Fields wrote:
> On Tue, Mar 15, 2011 at 12:54:01PM -0400, Chuck Lever wrote:
> > 
> > On Mar 15, 2011, at 12:13 PM, J. Bruce Fields wrote:
> > > 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.
> 
> Oh, I forgot about that.
> 
> But, checking....  Actually, it looks like it's not set for NFSACL--from
> a quick grep, it appears that only the callback server sets it.
> 
> > > 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.
> 
> There are so many to expose.
> 
> > :-(  Maybe it deserves some soak-time in linux-next.
> 
> Sure.

(Roel Kluin, could you revise and resubmit that?  I'd do it in two
patches: first just fix the bug you found, but just use a "goto out" or
a "return" instead; then fix the lack of cleanup if you can.)

--b.

> 
> --b.
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