From:   Michal Wilczynski <redacted>
Date:   Thu, 27 Oct 2022 15:00:43 +0200

Intel 100G card internal firmware hierarchy for Hierarchicial QoS is very
rigid and can't be easily removed. This requires an ability to export
default hierarchy to allow user to modify it. Currently the driver is
only able to create the 'leaf' nodes, which usually represent the vport.
This is not enough for HQoS implemented in Intel hardware.

Introduce new function devl_rate_node_create() that allows for creation
of the devlink-rate nodes from the driver.

I would swap the order of paragraphs above.

[...]

One space to much before `char *node_name`

[...]
 

+/**
+ * devl_rate_node_create - create devlink rate node
+ * @devlink: devlink instance
+ * @priv: driver private data
+ * @node_name: name of the resulting node
+ * @parent_name: name of the parent node
+ *
+ * Create devlink rate object of type node
+ */
+int devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name, char *parent_name)
+{
+	struct devlink_rate *rate_node;
+	struct devlink_rate *parent;
+
+	rate_node = devlink_rate_node_get_by_name(devlink, node_name);
+	if (!IS_ERR(rate_node))
+		return -EEXIST;
+
+	rate_node = kzalloc(sizeof(*rate_node), GFP_KERNEL);
+	if (!rate_node)
+		return -ENOMEM;
+
+	if (parent_name) {
+		parent = devlink_rate_node_get_by_name(devlink, parent_name);
+		if (IS_ERR(parent))
+			return -ENODEV;

`rate_node` is leaked on error path

+		rate_node->parent = parent;
+		refcount_inc(&rate_node->parent->refcnt);
+	}
+
+	rate_node->type = DEVLINK_RATE_TYPE_NODE;
+	rate_node->devlink = devlink;
+	rate_node->priv = priv;
+
+	rate_node->name = kzalloc(DEVLINK_RATE_NAME_MAX_LEN, GFP_KERNEL);
+	if (!rate_node->name)
+		return -ENOMEM;
+
+	strscpy(rate_node->name, node_name, DEVLINK_RATE_NAME_MAX_LEN);

Again a memleak on error path.
It looks also that we could use kstrndup() instead of kzalloc+strscpy combo.
Finally, I would centralize memory allocation failures.

+
+	refcount_set(&rate_node->refcnt, 1);
+	list_add(&rate_node->list, &devlink->rate_list);
+	devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devl_rate_node_create);
+

[...]

--PK