nfsd: return CLID_INUSE for unexpected SETCLIENTID_CONFIRM case

Somebody with a Solaris client was hitting this case.  We haven't
figured out why yet, and don't have a reproducer.  Meanwhile Frank
noticed that RFC 7530 actually recommends CLID_INUSE for this case.
Unlikely to help the original reporter, but may as well fix it.

Reported-by: Frank Filz <ffilzlnx@mindspring.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 416f32e34a33..08746ec1d44a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3111,10 +3111,11 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
         /*
          * We try hard to give out unique clientid's, so if we get an
          * attempt to confirm the same clientid with a different cred,
-         * there's a bug somewhere.  Let's charitably assume it's our
-         * bug.
+         * the client may be buggy; this should never happen.
+         *
+         * Nevertheless, RFC 7530 recommends INUSE for this case:
          */
-        status = nfserr_serverfault;
+        status = nfserr_clid_inuse;
         if (unconf && !same_creds(&unconf->cl_cred, &rqstp->rq_cred))
                 goto out;
         if (conf && !same_creds(&conf->cl_cred, &rqstp->rq_cred))