NFSD: Adjust cb_shutdown tracepoint

Show when the upper layer requested a shutdown. RPC tracepoints can
already show when rpc_shutdown_client() is called.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4callback.c

@@ -1233,6 +1233,9 @@ void nfsd4_destroy_callback_queue(void)
 /* must be called under the state lock */
 void nfsd4_shutdown_callback(struct nfs4_client *clp)
 {
+	if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
+		trace_nfsd_cb_shutdown(clp);
+
 	set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
 	/*
 	 * Note this won't actually result in a null callback;
@@ -1278,7 +1281,6 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 	 * kill the old client:
 	 */
 	if (clp->cl_cb_client) {
-		trace_nfsd_cb_shutdown(clp);
 		rpc_shutdown_client(clp->cl_cb_client);
 		clp->cl_cb_client = NULL;
 		put_cred(clp->cl_cb_cred);