Re: [PATCH 02/14] nfsd: Add missing gen_confirm in nfsd4_setclientid()

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Jul 15, 2015 at 04:47:48PM -0400, J. Bruce Fields wrote:
> On Mon, Jul 13, 2015 at 05:29:41PM +0800, Kinglong Mee wrote:
> > Commit 294ac32e99 "nfsd: protect clid and verifier generation with client_lock"
> > have moved gen_confirm() to gen_clid().
> 
> This means the statement in that earlier commit is wrong:
> 
> 	
> 	With this, there's no need to keep two counters as they'd always
> 	be in sync anyway, so just use the clientid_counter for both.
> 
> Looks to me like this may need a separate counter to eliminate the
> possibibility of returning the same confirm twice for a one clientid?

(but frankly I can never completely review changes to the
setclientid/setclientid_confirm behavior without rereading RFC 7530
16.33.5 every time, which is a slog.  Might help to contrive a pynfs
test derived from that text which tests for this particular behavior.)

> 
> --b.
> 
> > 
> > After it, setclientid will return a bad reply with all zero confirms
> > after copy_clid().
> > 
> > Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
> > ---
> >  fs/nfsd/nfs4state.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index e0a4556..b1f84fc 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -3042,10 +3042,11 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> >  	unconf = find_unconfirmed_client_by_name(&clname, nn);
> >  	if (unconf)
> >  		unhash_client_locked(unconf);
> > -	if (conf && same_verf(&conf->cl_verifier, &clverifier))
> > +	if (conf && same_verf(&conf->cl_verifier, &clverifier)) {
> >  		/* case 1: probable callback update */
> >  		copy_clid(new, conf);
> > -	else /* case 4 (new client) or cases 2, 3 (client reboot): */
> > +		gen_confirm(new, nn);
> > +	} else /* case 4 (new client) or cases 2, 3 (client reboot): */
> >  		gen_clid(new, nn);
> >  	new->cl_minorversion = 0;
> >  	gen_callback(new, setclid, rqstp);
> > -- 
> > 2.4.3