1 files changed, 87 insertions, 30 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index f6c17e75f20e..691ccf8049a4 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -151,33 +151,94 @@ out:
 }
 EXPORT_SYMBOL_GPL(xprt_unregister_transport);
 
-/**
- * xprt_load_transport - load a transport implementation
- * @transport_name: transport to load
- *
- * Returns:
- * 0:		transport successfully loaded
- * -ENOENT:	transport module not available
- */
-int xprt_load_transport(const char *transport_name)
+static void
+xprt_class_release(const struct xprt_class *t)
 {
-	struct xprt_class *t;
-	int result;
+	module_put(t->owner);
+}
+
+static const struct xprt_class *
+xprt_class_find_by_ident_locked(int ident)
+{
+	const struct xprt_class *t;
+
+	list_for_each_entry(t, &xprt_list, list) {
+		if (t->ident != ident)
+			continue;
+		if (!try_module_get(t->owner))
+			continue;
+		return t;
+	}
+	return NULL;
+}
+
+static const struct xprt_class *
+xprt_class_find_by_ident(int ident)
+{
+	const struct xprt_class *t;
 
-	result = 0;
 	spin_lock(&xprt_list_lock);
+	t = xprt_class_find_by_ident_locked(ident);
+	spin_unlock(&xprt_list_lock);
+	return t;
+}
+
+static const struct xprt_class *
+xprt_class_find_by_netid_locked(const char *netid)
+{
+	const struct xprt_class *t;
+	unsigned int i;
+
 	list_for_each_entry(t, &xprt_list, list) {
-		if (strcmp(t->name, transport_name) == 0) {
-			spin_unlock(&xprt_list_lock);
-			goto out;
+		for (i = 0; t->netid[i][0] != '\0'; i++) {
+			if (strcmp(t->netid[i], netid) != 0)
+				continue;
+			if (!try_module_get(t->owner))
+				continue;
+			return t;
 		}
 	}
+	return NULL;
+}
+
+static const struct xprt_class *
+xprt_class_find_by_netid(const char *netid)
+{
+	const struct xprt_class *t;
+
+	spin_lock(&xprt_list_lock);
+	t = xprt_class_find_by_netid_locked(netid);
+	if (!t) {
+		spin_unlock(&xprt_list_lock);
+		request_module("rpc%s", netid);
+		spin_lock(&xprt_list_lock);
+		t = xprt_class_find_by_netid_locked(netid);
+	}
 	spin_unlock(&xprt_list_lock);
-	result = request_module("xprt%s", transport_name);
-out:
-	return result;
+	return t;
+}
+
+/**
+ * xprt_find_transport_ident - convert a netid into a transport identifier
+ * @netid: transport to load
+ *
+ * Returns:
+ * > 0:		transport identifier
+ * -ENOENT:	transport module not available
+ */
+int xprt_find_transport_ident(const char *netid)
+{
+	const struct xprt_class *t;
+	int ret;
+
+	t = xprt_class_find_by_netid(netid);
+	if (!t)
+		return -ENOENT;
+	ret = t->ident;
+	xprt_class_release(t);
+	return ret;
 }
-EXPORT_SYMBOL_GPL(xprt_load_transport);
+EXPORT_SYMBOL_GPL(xprt_find_transport_ident);
 
 static void xprt_clear_locked(struct rpc_xprt *xprt)
 {
@@ -1896,21 +1957,17 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net)
 struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
 {
 	struct rpc_xprt	*xprt;
-	struct xprt_class *t;
+	const struct xprt_class *t;
 
-	spin_lock(&xprt_list_lock);
-	list_for_each_entry(t, &xprt_list, list) {
-		if (t->ident == args->ident) {
-			spin_unlock(&xprt_list_lock);
-			goto found;
-		}
+	t = xprt_class_find_by_ident(args->ident);
+	if (!t) {
+		dprintk("RPC: transport (%d) not supported\n", args->ident);
+		return ERR_PTR(-EIO);
 	}
-	spin_unlock(&xprt_list_lock);
-	dprintk("RPC: transport (%d) not supported\n", args->ident);
-	return ERR_PTR(-EIO);
 
-found:
 	xprt = t->setup(args);
+	xprt_class_release(t);
+
 	if (IS_ERR(xprt))
 		goto out;
 	if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)