+ struct rpc_clnt *client;
+
+ if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
+ return -EINVAL;
+ if (cb->cb_minorversion) {
+ args.bc_xprt = clp->cl_cb_xprt;
+ args.protocol = XPRT_TRANSPORT_BC_TCP;
+ }
+ /* Create RPC client */
+ client = rpc_create(&args);
+ if (IS_ERR(client)) {
+ dprintk("NFSD: couldn't create callback client: %ld\n",
+ PTR_ERR(client));
+ return PTR_ERR(client);
+ }
+ cb->cb_client = client;
+ return 0;
+
+}
+
+static void warn_no_callback_path(struct nfs4_client *clp, int reason)
+{
+ dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
+ (int)clp->cl_name.len, clp->cl_name.data, reason);
+}
+
+static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
+{
+ struct nfs4_client *clp = calldata;
+
+ if (task->tk_status)
+ warn_no_callback_path(clp, task->tk_status);
+ else
+ atomic_set(&clp->cl_cb_conn.cb_set, 1);
+}
+
+static const struct rpc_call_ops nfsd4_cb_probe_ops = {
+ .rpc_call_done = nfsd4_cb_probe_done,
+};
+
+static struct rpc_cred *callback_cred;
+
+int set_callback_cred(void)
+{
+ if (callback_cred)
+ return 0;
+ callback_cred = rpc_lookup_machine_cred();
+ if (!callback_cred)
+ return -ENOMEM;
+ return 0;
+}
+
+
+void do_probe_callback(struct nfs4_client *clp)
+{
+ struct nfs4_cb_conn *cb = &clp->cl_cb_conn;