hsr: rename debugfs file when interface name is changed

hsr interface has own debugfs file, which name is same with interface name.
So, interface name is changed, debugfs file name should be changed too.

Fixes: fc4ecaeebd26 ("net: hsr: add debugfs support for display node list")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/hsr/hsr_debugfs.c b/net/hsr/hsr_debugfs.c
index a7462a7..d5f709b 100644
--- a/net/hsr/hsr_debugfs.c
+++ b/net/hsr/hsr_debugfs.c
@@ -65,6 +65,19 @@ hsr_node_table_open(struct inode *inode, struct file *filp)
 	return single_open(filp, hsr_node_table_show, inode->i_private);
 }
 
+void hsr_debugfs_rename(struct net_device *dev)
+{
+	struct hsr_priv *priv = netdev_priv(dev);
+	struct dentry *d;
+
+	d = debugfs_rename(hsr_debugfs_root_dir, priv->node_tbl_root,
+			   hsr_debugfs_root_dir, dev->name);
+	if (IS_ERR(d))
+		netdev_warn(dev, "failed to rename\n");
+	else
+		priv->node_tbl_root = d;
+}
+
 static const struct file_operations hsr_fops = {
 	.open	= hsr_node_table_open,
 	.read	= seq_read,
diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
index 4908963..ea23eb7 100644
--- a/net/hsr/hsr_main.c
+++ b/net/hsr/hsr_main.c
@@ -45,6 +45,9 @@ static int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
 	case NETDEV_CHANGE:	/* Link (carrier) state changes */
 		hsr_check_carrier_and_operstate(hsr);
 		break;
+	case NETDEV_CHANGENAME:
+		hsr_debugfs_rename(dev);
+		break;
 	case NETDEV_CHANGEADDR:
 		if (port->type == HSR_PT_MASTER) {
 			/* This should not happen since there's no
diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h
index 55d2057..8d885bc 100644
--- a/net/hsr/hsr_main.h
+++ b/net/hsr/hsr_main.h
@@ -184,11 +184,15 @@ static inline u16 hsr_get_skb_sequence_nr(struct sk_buff *skb)
 }
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
+void hsr_debugfs_rename(struct net_device *dev);
 void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev);
 void hsr_debugfs_term(struct hsr_priv *priv);
 void hsr_debugfs_create_root(void);
 void hsr_debugfs_remove_root(void);
 #else
+static inline void void hsr_debugfs_rename(struct net_device *dev)
+{
+}
 static inline void hsr_debugfs_init(struct hsr_priv *priv,
 				    struct net_device *hsr_dev)
 {}