+/**
+ * xprt_register_transport - register a transport implementation
+ * @transport: transport to register
+ *
+ * If a transport implementation is loaded as a kernel module, it can
+ * call this interface to make itself known to the RPC client.
+ *
+ * Returns:
+ * 0: transport successfully registered
+ * -EEXIST: transport already registered
+ * -EINVAL: transport module being unloaded
+ */
+int xprt_register_transport(struct xprt_class *transport)
+{
+ struct xprt_class *t;
+ int result;
+
+ result = -EEXIST;
+ spin_lock(&xprt_list_lock);
+ list_for_each_entry(t, &xprt_list, list) {
+ /* don't register the same transport class twice */
+ if (t->ident == transport->ident)
+ goto out;
+ }
+
+ result = -EINVAL;
+ if (try_module_get(THIS_MODULE)) {
+ list_add_tail(&transport->list, &xprt_list);
+ printk(KERN_INFO "RPC: Registered %s transport module.\n",
+ transport->name);
+ result = 0;
+ }
+
+out:
+ spin_unlock(&xprt_list_lock);
+ return result;
+}
+EXPORT_SYMBOL_GPL(xprt_register_transport);
+
+/**
+ * xprt_unregister_transport - unregister a transport implementation
+ * @transport: transport to unregister
+ *
+ * Returns:
+ * 0: transport successfully unregistered
+ * -ENOENT: transport never registered
+ */
+int xprt_unregister_transport(struct xprt_class *transport)
+{
+ struct xprt_class *t;
+ int result;
+
+ result = 0;
+ spin_lock(&xprt_list_lock);
+ list_for_each_entry(t, &xprt_list, list) {
+ if (t == transport) {
+ printk(KERN_INFO
+ "RPC: Unregistered %s transport module.\n",
+ transport->name);
+ list_del_init(&transport->list);
+ module_put(THIS_MODULE);
+ goto out;
+ }
+ }
+ result = -ENOENT;
+
+out:
+ spin_unlock(&xprt_list_lock);
+ return result;
+}
+EXPORT_SYMBOL_GPL(xprt_unregister_transport);
+