diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 484554900f7d..4091e978aef2 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -58,7 +58,21 @@ static inline struct rb_node *rb_first(const struct rb_root *root)
 		n = n->rb_left;
 	return n;
 }
-extern struct rb_node *rb_last(const struct rb_root *);
+
+/*
+ * This function returns the last node (in sort order) of the tree.
+ */
+static inline struct rb_node *rb_last(const struct rb_root *root)
+{
+	struct rb_node	*n;
+
+	n = root->rb_node;
+	if (!n)
+		return NULL;
+	while (n->rb_right)
+		n = n->rb_right;
+	return n;
+}
 
 /* Postorder iteration - always visit the parent after its children */
 extern struct rb_node *rb_first_postorder(const struct rb_root *);
diff --git a/lib/rbtree.c b/lib/rbtree.c
index b946eb4b759d..18d42bcf4ec9 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -460,19 +460,6 @@ void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
 }
 EXPORT_SYMBOL(__rb_insert_augmented);
 
-struct rb_node *rb_last(const struct rb_root *root)
-{
-	struct rb_node	*n;
-
-	n = root->rb_node;
-	if (!n)
-		return NULL;
-	while (n->rb_right)
-		n = n->rb_right;
-	return n;
-}
-EXPORT_SYMBOL(rb_last);
-
 struct rb_node *rb_next(const struct rb_node *node)
 {
 	struct rb_node *parent;
diff --git a/rust/helpers/rbtree.c b/rust/helpers/rbtree.c
index d0e452234632..2a0eabbb4160 100644
--- a/rust/helpers/rbtree.c
+++ b/rust/helpers/rbtree.c
@@ -12,3 +12,8 @@ struct rb_node *rust_helper_rb_first(const struct rb_root *root)
 {
 	return rb_first(root);
 }
+
+struct rb_node *rust_helper_rb_last(const struct rb_root *root)
+{
+	return rb_last(root);
+}