[PATCH NET-PREV 22/51] vxlan: Use __register_netdevice in .newlink

[Kirill Tkhai <tkhai@ya.ru>]

The objective is to conform .newlink with its callers,
which already assign nd_lock (and matches master nd_lock
if there is one).

Also, use __unregister_netdevice() since we know
there is held lock in that path.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
---
 drivers/net/vxlan/vxlan_core.c |   36 +++++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index b041ddc2ab34..369f7b667424 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -3950,7 +3950,7 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 			return err;
 	}
 
-	err = register_netdevice(dev);
+	err = __register_netdevice(dev);
 	if (err)
 		goto errout;
 	unregister = true;
@@ -4001,7 +4001,7 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev,
 		__vxlan_fdb_free(f);
 unregister:
 	if (unregister)
-		unregister_netdevice(dev);
+		__unregister_netdevice(dev);
 	return err;
 }
 
@@ -4604,22 +4604,37 @@ struct net_device *vxlan_dev_create(struct net *net, const char *name,
 				    u8 name_assign_type,
 				    struct vxlan_config *conf)
 {
+	struct net_device *dev, *lowerdev = NULL;
 	struct nlattr *tb[IFLA_MAX + 1];
-	struct net_device *dev;
+	struct nd_lock *nd_lock;
 	int err;
 
 	memset(&tb, 0, sizeof(tb));
 
+	if (conf->remote_ifindex) {
+		lowerdev = __dev_get_by_index(net, conf->remote_ifindex);
+		if (!lowerdev)
+			return ERR_PTR(-ENODEV);
+	}
+
 	dev = rtnl_create_link(net, name, name_assign_type,
 			       &vxlan_link_ops, tb, NULL);
 	if (IS_ERR(dev))
 		return dev;
 
-	err = __vxlan_dev_create(net, dev, conf, NULL);
-	if (err < 0) {
-		free_netdev(dev);
-		return ERR_PTR(err);
+	if (lowerdev) {
+		lock_netdev(lowerdev, &nd_lock);
+		attach_nd_lock(dev, nd_lock);
+	} else {
+		err = -ENOMEM;
+		if (!attach_new_nd_lock(dev))
+			goto err_free;
+		lock_netdev(dev, &nd_lock);
 	}
+	err = __vxlan_dev_create(net, dev, conf, NULL);
+	if (err < 0)
+		goto err_detach;
+	unlock_netdev(nd_lock);
 
 	err = rtnl_configure_link(dev, NULL, 0, NULL);
 	if (err < 0) {
@@ -4631,6 +4646,13 @@ struct net_device *vxlan_dev_create(struct net *net, const char *name,
 	}
 
 	return dev;
+
+err_detach:
+	detach_nd_lock(dev);
+	unlock_netdev(nd_lock);
+err_free:
+	free_netdev(dev);
+	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(vxlan_dev_create);