Merge branch 'enslavement-extack'

David Ahern says:

====================
net: Plumb extack error reporting to enslavements

Another round of extending extack error reporting, this time for
enslavements through ndo_add_slave and notifiers.

v2
- changed how the messages are added to bonding driver per Jiri's request
- fixed spectrum message for LAG overflow per Ido's comment
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -1217,14 +1217,15 @@ static enum netdev_lag_tx_type bond_lag_tx_type(struct bonding *bond)
 	}
 }
 
-static int bond_master_upper_dev_link(struct bonding *bond, struct slave *slave)
+static int bond_master_upper_dev_link(struct bonding *bond, struct slave *slave,
+				      struct netlink_ext_ack *extack)
 {
 	struct netdev_lag_upper_info lag_upper_info;
 	int err;
 
 	lag_upper_info.tx_type = bond_lag_tx_type(bond);
 	err = netdev_master_upper_dev_link(slave->dev, bond->dev, slave,
-					   &lag_upper_info);
+					   &lag_upper_info, extack);
 	if (err)
 		return err;
 	rtmsg_ifinfo(RTM_NEWLINK, slave->dev, IFF_SLAVE, GFP_KERNEL);
@@ -1328,7 +1329,8 @@ void bond_lower_state_changed(struct slave *slave)
 }
 
 /* enslave device <slave> to bond device <master> */
-int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
+int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
+		 struct netlink_ext_ack *extack)
 {
 	struct bonding *bond = netdev_priv(bond_dev);
 	const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
@@ -1346,12 +1348,14 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 
 	/* already in-use? */
 	if (netdev_is_rx_handler_busy(slave_dev)) {
+		NL_SET_ERR_MSG(extack, "Device is in use and cannot be enslaved");
 		netdev_err(bond_dev,
 			   "Error: Device is in use and cannot be enslaved\n");
 		return -EBUSY;
 	}
 
 	if (bond_dev == slave_dev) {
+		NL_SET_ERR_MSG(extack, "Cannot enslave bond to itself.");
 		netdev_err(bond_dev, "cannot enslave bond to itself.\n");
 		return -EPERM;
 	}
@@ -1362,6 +1366,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 		netdev_dbg(bond_dev, "%s is NETIF_F_VLAN_CHALLENGED\n",
 			   slave_dev->name);
 		if (vlan_uses_dev(bond_dev)) {
+			NL_SET_ERR_MSG(extack, "Can not enslave VLAN challenged device to VLAN enabled bond");
 			netdev_err(bond_dev, "Error: cannot enslave VLAN challenged slave %s on VLAN enabled bond %s\n",
 				   slave_dev->name, bond_dev->name);
 			return -EPERM;
@@ -1381,6 +1386,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 	 * enslaving it; the old ifenslave will not.
 	 */
 	if (slave_dev->flags & IFF_UP) {
+		NL_SET_ERR_MSG(extack, "Device can not be enslaved while up");
 		netdev_err(bond_dev, "%s is up - this may be due to an out of date ifenslave\n",
 			   slave_dev->name);
 		return -EPERM;
@@ -1421,6 +1427,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 						 bond_dev);
 		}
 	} else if (bond_dev->type != slave_dev->type) {
+		NL_SET_ERR_MSG(extack, "Device type is different from other slaves");
 		netdev_err(bond_dev, "%s ether type (%d) is different from other slaves (%d), can not enslave it\n",
 			   slave_dev->name, slave_dev->type, bond_dev->type);
 		return -EINVAL;
@@ -1428,6 +1435,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 
 	if (slave_dev->type == ARPHRD_INFINIBAND &&
 	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
+		NL_SET_ERR_MSG(extack, "Only active-backup mode is supported for infiniband slaves");
 		netdev_warn(bond_dev, "Type (%d) supports only active-backup mode\n",
 			    slave_dev->type);
 		res = -EOPNOTSUPP;
@@ -1443,6 +1451,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 				bond->params.fail_over_mac = BOND_FOM_ACTIVE;
 				netdev_warn(bond_dev, "Setting fail_over_mac to active for active-backup mode\n");
 			} else {
+				NL_SET_ERR_MSG(extack, "Slave device does not support setting the MAC address, but fail_over_mac is not set to active");
 				netdev_err(bond_dev, "The slave device specified does not support setting the MAC address, but fail_over_mac is not set to active\n");
 				res = -EOPNOTSUPP;
 				goto err_undo_flags;
@@ -1709,7 +1718,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 		goto err_detach;
 	}
 
-	res = bond_master_upper_dev_link(bond, new_slave);
+	res = bond_master_upper_dev_link(bond, new_slave, extack);
 	if (res) {
 		netdev_dbg(bond_dev, "Error %d calling bond_master_upper_dev_link\n", res);
 		goto err_unregister;
@@ -3492,7 +3501,7 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
 	switch (cmd) {
 	case BOND_ENSLAVE_OLD:
 	case SIOCBONDENSLAVE:
-		res = bond_enslave(bond_dev, slave_dev);
+		res = bond_enslave(bond_dev, slave_dev, NULL);
 		break;
 	case BOND_RELEASE_OLD:
 	case SIOCBONDRELEASE:

drivers/net/bonding/bond_options.c

@@ -1383,7 +1383,7 @@ static int bond_option_slaves_set(struct bonding *bond,
 	switch (command[0]) {
 	case '+':
 		netdev_dbg(bond->dev, "Adding slave %s\n", dev->name);
-		ret = bond_enslave(bond->dev, dev);
+		ret = bond_enslave(bond->dev, dev, NULL);
 		break;
 
 	case '-':

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -4019,14 +4019,21 @@ static int mlxsw_sp_lag_index_get(struct mlxsw_sp *mlxsw_sp,
 static bool
 mlxsw_sp_master_lag_check(struct mlxsw_sp *mlxsw_sp,
 			  struct net_device *lag_dev,
-			  struct netdev_lag_upper_info *lag_upper_info)
+			  struct netdev_lag_upper_info *lag_upper_info,
+			  struct netlink_ext_ack *extack)
 {
 	u16 lag_id;
 
-	if (mlxsw_sp_lag_index_get(mlxsw_sp, lag_dev, &lag_id) != 0)
+	if (mlxsw_sp_lag_index_get(mlxsw_sp, lag_dev, &lag_id) != 0) {
+		NL_SET_ERR_MSG(extack,
+			       "spectrum: Exceeded number of supported LAG devices");
 		return false;
-	if (lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH)
+	}
+	if (lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH) {
+		NL_SET_ERR_MSG(extack,
+			       "spectrum: LAG device using unsupported Tx type");
 		return false;
+	}
 	return true;
 }
 
@@ -4231,6 +4238,7 @@ static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev,
 {
 	struct netdev_notifier_changeupper_info *info;
 	struct mlxsw_sp_port *mlxsw_sp_port;
+	struct netlink_ext_ack *extack;
 	struct net_device *upper_dev;
 	struct mlxsw_sp *mlxsw_sp;
 	int err = 0;
@@ -4238,6 +4246,7 @@ static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev,
 	mlxsw_sp_port = netdev_priv(dev);
 	mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	info = ptr;
+	extack = netdev_notifier_info_to_extack(&info->info);
 
 	switch (event) {
 	case NETDEV_PRECHANGEUPPER:
@@ -4245,25 +4254,43 @@ static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev,
 		if (!is_vlan_dev(upper_dev) &&
 		    !netif_is_lag_master(upper_dev) &&
 		    !netif_is_bridge_master(upper_dev) &&
-		    !netif_is_ovs_master(upper_dev))
+		    !netif_is_ovs_master(upper_dev)) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Unknown upper device type");
 			return -EINVAL;
+		}
 		if (!info->linking)
 			break;
-		if (netdev_has_any_upper_dev(upper_dev))
+		if (netdev_has_any_upper_dev(upper_dev)) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Enslaving a port to a device that already has an upper device is not supported");
 			return -EINVAL;
+		}
 		if (netif_is_lag_master(upper_dev) &&
 		    !mlxsw_sp_master_lag_check(mlxsw_sp, upper_dev,
-					       info->upper_info))
+					       info->upper_info, extack))
 			return -EINVAL;
-		if (netif_is_lag_master(upper_dev) && vlan_uses_dev(dev))
+		if (netif_is_lag_master(upper_dev) && vlan_uses_dev(dev)) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Master device is a LAG master and this device has a VLAN");
 			return -EINVAL;
+		}
 		if (netif_is_lag_port(dev) && is_vlan_dev(upper_dev) &&
-		    !netif_is_lag_master(vlan_dev_real_dev(upper_dev)))
+		    !netif_is_lag_master(vlan_dev_real_dev(upper_dev))) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Can not put a VLAN on a LAG port");
 			return -EINVAL;
-		if (netif_is_ovs_master(upper_dev) && vlan_uses_dev(dev))
+		}
+		if (netif_is_ovs_master(upper_dev) && vlan_uses_dev(dev)) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Master device is an OVS master and this device has a VLAN");
 			return -EINVAL;
-		if (netif_is_ovs_port(dev) && is_vlan_dev(upper_dev))
+		}
+		if (netif_is_ovs_port(dev) && is_vlan_dev(upper_dev)) {
+			NL_SET_ERR_MSG(extack,
+				       "spectrum: Can not put a VLAN on an OVS port");
 			return -EINVAL;
+		}
 		break;
 	case NETDEV_CHANGEUPPER:
 		upper_dev = info->upper_dev;

drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c

@@ -178,7 +178,7 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev,
 	if (err)
 		goto err1;
 
-	err = netdev_master_upper_dev_link(dev, real_dev, NULL, NULL);
+	err = netdev_master_upper_dev_link(dev, real_dev, NULL, NULL, extack);
 	if (err)
 		goto err2;
 

drivers/net/hyperv/netvsc_drv.c

@@ -1748,7 +1748,7 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
 		goto rx_handler_failed;
 	}
 
-	ret = netdev_upper_dev_link(vf_netdev, ndev);
+	ret = netdev_upper_dev_link(vf_netdev, ndev, NULL);
 	if (ret != 0) {
 		netdev_err(vf_netdev,
 			   "can not set master device %s (err = %d)\n",

drivers/net/ipvlan/ipvlan_main.c

@@ -584,7 +584,7 @@ int ipvlan_link_new(struct net *src_net, struct net_device *dev,
 	if (err < 0)
 		goto remove_ida;
 
-	err = netdev_upper_dev_link(phy_dev, dev);
+	err = netdev_upper_dev_link(phy_dev, dev, extack);
 	if (err) {
 		goto unregister_netdev;
 	}

drivers/net/macsec.c

@@ -3244,7 +3244,7 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 				       &macsec_netdev_addr_lock_key,
 				       macsec_get_nest_level(dev));
 
-	err = netdev_upper_dev_link(real_dev, dev);
+	err = netdev_upper_dev_link(real_dev, dev, extack);
 	if (err < 0)
 		goto unregister;
 

drivers/net/macvlan.c

@@ -1344,7 +1344,8 @@ static int macvlan_changelink_sources(struct macvlan_dev *vlan, u32 mode,
 }
 
 int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[])
+			   struct nlattr *tb[], struct nlattr *data[],
+			   struct netlink_ext_ack *extack)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
 	struct macvlan_port *port;
@@ -1433,7 +1434,7 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 		goto destroy_macvlan_port;
 
 	dev->priv_flags |= IFF_MACVLAN;
-	err = netdev_upper_dev_link(lowerdev, dev);
+	err = netdev_upper_dev_link(lowerdev, dev, extack);
 	if (err)
 		goto unregister_netdev;
 
@@ -1456,7 +1457,7 @@ static int macvlan_newlink(struct net *src_net, struct net_device *dev,
 			   struct nlattr *tb[], struct nlattr *data[],
 			   struct netlink_ext_ack *extack)
 {
-	return macvlan_common_newlink(src_net, dev, tb, data);
+	return macvlan_common_newlink(src_net, dev, tb, data, extack);
 }
 
 void macvlan_dellink(struct net_device *dev, struct list_head *head)

drivers/net/macvtap.c

@@ -105,7 +105,7 @@ static int macvtap_newlink(struct net *src_net, struct net_device *dev,
 	/* Don't put anything that may fail after macvlan_common_newlink
 	 * because we can't undo what it does.
 	 */
-	err = macvlan_common_newlink(src_net, dev, tb, data);
+	err = macvlan_common_newlink(src_net, dev, tb, data, extack);
 	if (err) {
 		netdev_rx_handler_unregister(dev);
 		return err;

drivers/net/team/team.c

@@ -1112,7 +1112,7 @@ static int team_upper_dev_link(struct team *team, struct team_port *port)
 
 	lag_upper_info.tx_type = team->mode->lag_tx_type;
 	err = netdev_master_upper_dev_link(port->dev, team->dev, NULL,
-					   &lag_upper_info);
+					   &lag_upper_info, NULL);
 	if (err)
 		return err;
 	port->dev->priv_flags |= IFF_TEAM_PORT;
@@ -1914,7 +1914,8 @@ static int team_netpoll_setup(struct net_device *dev,
 }
 #endif
 
-static int team_add_slave(struct net_device *dev, struct net_device *port_dev)
+static int team_add_slave(struct net_device *dev, struct net_device *port_dev,
+			  struct netlink_ext_ack *extack)
 {
 	struct team *team = netdev_priv(dev);
 	int err;

drivers/net/usb/qmi_wwan.c

@@ -221,7 +221,7 @@ static int qmimux_register_device(struct net_device *real_dev, u8 mux_id)
 	/* Account for reference in struct qmimux_priv_priv */
 	dev_hold(real_dev);
 
-	err = netdev_upper_dev_link(real_dev, new_dev);
+	err = netdev_upper_dev_link(real_dev, new_dev, NULL);
 	if (err)
 		goto out_unregister_netdev;
 

drivers/net/vrf.c

@@ -764,18 +764,22 @@ static void cycle_netdev(struct net_device *dev)
 	}
 }
 
-static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
+static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
+			    struct netlink_ext_ack *extack)
 {
 	int ret;
 
 	/* do not allow loopback device to be enslaved to a VRF.
 	 * The vrf device acts as the loopback for the vrf.
 	 */
-	if (port_dev == dev_net(dev)->loopback_dev)
+	if (port_dev == dev_net(dev)->loopback_dev) {
+		NL_SET_ERR_MSG(extack,
+			       "Can not enslave loopback device to a VRF");
 		return -EOPNOTSUPP;
+	}
 
 	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
-	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
+	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
 	if (ret < 0)
 		goto err;
 
@@ -788,12 +792,19 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 	return ret;
 }
 
-static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
+static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
+			 struct netlink_ext_ack *extack)
 {
-	if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
+	if (netif_is_l3_master(port_dev)) {
+		NL_SET_ERR_MSG(extack,
+			       "Can not enslave an L3 master device to a VRF");
+		return -EINVAL;
+	}
+
+	if (netif_is_l3_slave(port_dev))
 		return -EINVAL;
 
-	return do_vrf_add_slave(dev, port_dev);
+	return do_vrf_add_slave(dev, port_dev, extack);
 }
 
 /* inverse of do_vrf_add_slave */

include/linux/if_macvlan.h

@@ -72,7 +72,8 @@ static inline void macvlan_count_rx(const struct macvlan_dev *vlan,
 extern void macvlan_common_setup(struct net_device *dev);
 
 extern int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
-				  struct nlattr *tb[], struct nlattr *data[]);
+				  struct nlattr *tb[], struct nlattr *data[],
+				  struct netlink_ext_ack *extack);
 
 extern void macvlan_count_rx(const struct macvlan_dev *vlan,
 			     unsigned int len, bool success,

include/linux/netdevice.h

@@ -1246,7 +1246,8 @@ struct net_device_ops {
 						     u32 flow_id);
 #endif
 	int			(*ndo_add_slave)(struct net_device *dev,
-						 struct net_device *slave_dev);
+						 struct net_device *slave_dev,
+						 struct netlink_ext_ack *extack);
 	int			(*ndo_del_slave)(struct net_device *dev,
 						 struct net_device *slave_dev);
 	netdev_features_t	(*ndo_fix_features)(struct net_device *dev,
@@ -2309,7 +2310,8 @@ int register_netdevice_notifier(struct notifier_block *nb);
 int unregister_netdevice_notifier(struct notifier_block *nb);
 
 struct netdev_notifier_info {
-	struct net_device *dev;
+	struct net_device	*dev;
+	struct netlink_ext_ack	*extack;
 };
 
 struct netdev_notifier_change_info {
@@ -2334,6 +2336,7 @@ static inline void netdev_notifier_info_init(struct netdev_notifier_info *info,
 					     struct net_device *dev)
 {
 	info->dev = dev;
+	info->extack = NULL;
 }
 
 static inline struct net_device *
@@ -2342,6 +2345,12 @@ netdev_notifier_info_to_dev(const struct netdev_notifier_info *info)
 	return info->dev;
 }
 
+static inline struct netlink_ext_ack *
+netdev_notifier_info_to_extack(const struct netdev_notifier_info *info)
+{
+	return info->extack;
+}
+
 int call_netdevice_notifiers(unsigned long val, struct net_device *dev);
 
 
@@ -3910,10 +3919,12 @@ void *netdev_adjacent_get_private(struct list_head *adj_list);
 void *netdev_lower_get_first_private_rcu(struct net_device *dev);
 struct net_device *netdev_master_upper_dev_get(struct net_device *dev);
 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev);
-int netdev_upper_dev_link(struct net_device *dev, struct net_device *upper_dev);
+int netdev_upper_dev_link(struct net_device *dev, struct net_device *upper_dev,
+			  struct netlink_ext_ack *extack);
 int netdev_master_upper_dev_link(struct net_device *dev,
 				 struct net_device *upper_dev,
-				 void *upper_priv, void *upper_info);
+				 void *upper_priv, void *upper_info,
+				 struct netlink_ext_ack *extack);
 void netdev_upper_dev_unlink(struct net_device *dev,
 			     struct net_device *upper_dev);
 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname);

include/net/bonding.h

@@ -596,7 +596,8 @@ void bond_destroy_sysfs(struct bond_net *net);
 void bond_prepare_sysfs_group(struct bonding *bond);
 int bond_sysfs_slave_add(struct slave *slave);
 void bond_sysfs_slave_del(struct slave *slave);
-int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev);
+int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
+		 struct netlink_ext_ack *extack);
 int bond_release(struct net_device *bond_dev, struct net_device *slave_dev);
 u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb);
 int bond_set_carrier(struct bonding *bond);

net/8021q/vlan.c

@@ -138,7 +138,7 @@ int vlan_check_real_dev(struct net_device *real_dev,
 	return 0;
 }
 
-int register_vlan_dev(struct net_device *dev)
+int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack)
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev = vlan->real_dev;
@@ -174,7 +174,7 @@ int register_vlan_dev(struct net_device *dev)
 	if (err < 0)
 		goto out_uninit_mvrp;
 
-	err = netdev_upper_dev_link(real_dev, dev);
+	err = netdev_upper_dev_link(real_dev, dev, extack);
 	if (err)
 		goto out_unregister_netdev;
 
@@ -270,7 +270,7 @@ static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
 	vlan->flags = VLAN_FLAG_REORDER_HDR;
 
 	new_dev->rtnl_link_ops = &vlan_link_ops;
-	err = register_vlan_dev(new_dev);
+	err = register_vlan_dev(new_dev, NULL);
 	if (err < 0)
 		goto out_free_newdev;
 

net/8021q/vlan.h

@@ -107,7 +107,7 @@ void vlan_dev_get_realdev_name(const struct net_device *dev, char *result);
 int vlan_check_real_dev(struct net_device *real_dev,
 			__be16 protocol, u16 vlan_id);
 void vlan_setup(struct net_device *dev);
-int register_vlan_dev(struct net_device *dev);
+int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack);
 void unregister_vlan_dev(struct net_device *dev, struct list_head *head);
 bool vlan_dev_inherit_address(struct net_device *dev,
 			      struct net_device *real_dev);

net/8021q/vlan_netlink.c

@@ -160,7 +160,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 	if (err < 0)
 		return err;
 
-	return register_vlan_dev(dev);
+	return register_vlan_dev(dev, extack);
 }
 
 static inline size_t vlan_qos_map_size(unsigned int n)

net/batman-adv/hard-interface.c

@@ -738,7 +738,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 	bat_priv = netdev_priv(hard_iface->soft_iface);
 
 	ret = netdev_master_upper_dev_link(hard_iface->net_dev,
-					   soft_iface, NULL, NULL);
+					   soft_iface, NULL, NULL, NULL);
 	if (ret)
 		goto err_dev;
 

net/batman-adv/soft-interface.c

@@ -867,7 +867,8 @@ static int batadv_softif_init_late(struct net_device *dev)
  * Return: 0 if successful or error otherwise.
  */
 static int batadv_softif_slave_add(struct net_device *dev,
-				   struct net_device *slave_dev)
+				   struct net_device *slave_dev,
+				   struct netlink_ext_ack *extack)
 {
 	struct batadv_hard_iface *hard_iface;
 	struct net *net = dev_net(dev);

net/bridge/br_device.c

@@ -320,12 +320,13 @@ void br_netpoll_disable(struct net_bridge_port *p)
 
 #endif
 
-static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
+static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
+			struct netlink_ext_ack *extack)
 
 {
 	struct net_bridge *br = netdev_priv(dev);
 
-	return br_add_if(br, slave_dev);
+	return br_add_if(br, slave_dev, extack);
 }
 
 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)

net/bridge/br_if.c

@@ -480,7 +480,8 @@ netdev_features_t br_features_recompute(struct net_bridge *br,
 }
 
 /* called with RTNL */
-int br_add_if(struct net_bridge *br, struct net_device *dev)
+int br_add_if(struct net_bridge *br, struct net_device *dev,
+	      struct netlink_ext_ack *extack)
 {
 	struct net_bridge_port *p;
 	int err = 0;
@@ -500,16 +501,22 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 		return -EINVAL;
 
 	/* No bridging of bridges */
-	if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
+	if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
+		NL_SET_ERR_MSG(extack,
+			       "Can not enslave a bridge to a bridge");
 		return -ELOOP;
+	}
 
 	/* Device is already being bridged */
 	if (br_port_exists(dev))
 		return -EBUSY;
 
 	/* No bridging devices that dislike that (e.g. wireless) */
-	if (dev->priv_flags & IFF_DONT_BRIDGE)
+	if (dev->priv_flags & IFF_DONT_BRIDGE) {
+		NL_SET_ERR_MSG(extack,
+			       "Device does not allow enslaving to a bridge");
 		return -EOPNOTSUPP;
+	}
 
 	p = new_nbp(br, dev);
 	if (IS_ERR(p))
@@ -540,7 +547,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 
 	dev->priv_flags |= IFF_BRIDGE_PORT;
 
-	err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL);
+	err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 	if (err)
 		goto err5;
 

net/bridge/br_ioctl.c

@@ -98,7 +98,7 @@ static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
 		return -EINVAL;
 
 	if (isadd)
-		ret = br_add_if(br, dev);
+		ret = br_add_if(br, dev, NULL);
 	else
 		ret = br_del_if(br, dev);
 

net/bridge/br_private.h

@@ -566,7 +566,8 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
 void br_port_carrier_check(struct net_bridge_port *p);
 int br_add_bridge(struct net *net, const char *name);
 int br_del_bridge(struct net *net, const char *name);
-int br_add_if(struct net_bridge *br, struct net_device *dev);
+int br_add_if(struct net_bridge *br, struct net_device *dev,
+	      struct netlink_ext_ack *extack);
 int br_del_if(struct net_bridge *br, struct net_device *dev);
 int br_min_mtu(const struct net_bridge *br);
 netdev_features_t br_features_recompute(struct net_bridge *br,

net/core/dev.c

@@ -163,7 +163,6 @@ static struct list_head offload_base __read_mostly;
 
 static int netif_rx_internal(struct sk_buff *skb);
 static int call_netdevice_notifiers_info(unsigned long val,
-					 struct net_device *dev,
 					 struct netdev_notifier_info *info);
 static struct napi_struct *napi_by_id(unsigned int napi_id);
 
@@ -1339,10 +1338,11 @@ EXPORT_SYMBOL(netdev_features_change);
 void netdev_state_change(struct net_device *dev)
 {
 	if (dev->flags & IFF_UP) {
-		struct netdev_notifier_change_info change_info;
+		struct netdev_notifier_change_info change_info = {
+			.info.dev = dev,
+		};
 
-		change_info.flags_changed = 0;
-		call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
+		call_netdevice_notifiers_info(NETDEV_CHANGE,
 					      &change_info.info);
 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
 	}
@@ -1563,9 +1563,10 @@ EXPORT_SYMBOL(dev_disable_lro);
 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
 				   struct net_device *dev)
 {
-	struct netdev_notifier_info info;
+	struct netdev_notifier_info info = {
+		.dev = dev,
+	};
 
-	netdev_notifier_info_init(&info, dev);
 	return nb->notifier_call(nb, val, &info);
 }
 
@@ -1690,11 +1691,9 @@ EXPORT_SYMBOL(unregister_netdevice_notifier);
  */
 
 static int call_netdevice_notifiers_info(unsigned long val,
-					 struct net_device *dev,
 					 struct netdev_notifier_info *info)
 {
 	ASSERT_RTNL();
-	netdev_notifier_info_init(info, dev);
 	return raw_notifier_call_chain(&netdev_chain, val, info);
 }
 
@@ -1709,9 +1708,11 @@ static int call_netdevice_notifiers_info(unsigned long val,
 
 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
 {
-	struct netdev_notifier_info info;
+	struct netdev_notifier_info info = {
+		.dev = dev,
+	};
 
-	return call_netdevice_notifiers_info(val, dev, &info);
+	return call_netdevice_notifiers_info(val, &info);
 }
 EXPORT_SYMBOL(call_netdevice_notifiers);
 
@@ -6276,9 +6277,19 @@ static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
 
 static int __netdev_upper_dev_link(struct net_device *dev,
 				   struct net_device *upper_dev, bool master,
-				   void *upper_priv, void *upper_info)
-{
-	struct netdev_notifier_changeupper_info changeupper_info;
+				   void *upper_priv, void *upper_info,
+				   struct netlink_ext_ack *extack)
+{
+	struct netdev_notifier_changeupper_info changeupper_info = {
+		.info = {
+			.dev = dev,
+			.extack = extack,
+		},
+		.upper_dev = upper_dev,
+		.master = master,
+		.linking = true,
+		.upper_info = upper_info,
+	};
 	int ret = 0;
 
 	ASSERT_RTNL();
@@ -6296,12 +6307,7 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 	if (master && netdev_master_upper_dev_get(dev))
 		return -EBUSY;
 
-	changeupper_info.upper_dev = upper_dev;
-	changeupper_info.master = master;
-	changeupper_info.linking = true;
-	changeupper_info.upper_info = upper_info;
-
-	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
+	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
 					    &changeupper_info.info);
 	ret = notifier_to_errno(ret);
 	if (ret)
@@ -6312,7 +6318,7 @@ static int __netdev_upper_dev_link(struct net_device *dev,
 	if (ret)
 		return ret;
 
-	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
+	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
 					    &changeupper_info.info);
 	ret = notifier_to_errno(ret);
 	if (ret)
@@ -6337,9 +6343,11 @@ static int __netdev_upper_dev_link(struct net_device *dev,
  * returns zero.
  */
 int netdev_upper_dev_link(struct net_device *dev,
-			  struct net_device *upper_dev)
+			  struct net_device *upper_dev,
+			  struct netlink_ext_ack *extack)
 {
-	return __netdev_upper_dev_link(dev, upper_dev, false, NULL, NULL);
+	return __netdev_upper_dev_link(dev, upper_dev, false,
+				       NULL, NULL, extack);
 }
 EXPORT_SYMBOL(netdev_upper_dev_link);
 
@@ -6358,10 +6366,11 @@ EXPORT_SYMBOL(netdev_upper_dev_link);
  */
 int netdev_master_upper_dev_link(struct net_device *dev,
 				 struct net_device *upper_dev,
-				 void *upper_priv, void *upper_info)
+				 void *upper_priv, void *upper_info,
+				 struct netlink_ext_ack *extack)
 {
 	return __netdev_upper_dev_link(dev, upper_dev, true,
-				       upper_priv, upper_info);
+				       upper_priv, upper_info, extack);
 }
 EXPORT_SYMBOL(netdev_master_upper_dev_link);
 
@@ -6376,20 +6385,24 @@ EXPORT_SYMBOL(netdev_master_upper_dev_link);
 void netdev_upper_dev_unlink(struct net_device *dev,
 			     struct net_device *upper_dev)
 {
-	struct netdev_notifier_changeupper_info changeupper_info;
+	struct netdev_notifier_changeupper_info changeupper_info = {
+		.info = {
+			.dev = dev,
+		},
+		.upper_dev = upper_dev,
+		.linking = false,
+	};
 
 	ASSERT_RTNL();
 
-	changeupper_info.upper_dev = upper_dev;
 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
-	changeupper_info.linking = false;
 
-	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
+	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
 				      &changeupper_info.info);
 
 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
 
-	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
+	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
 				      &changeupper_info.info);
 }
 EXPORT_SYMBOL(netdev_upper_dev_unlink);
@@ -6405,11 +6418,13 @@ EXPORT_SYMBOL(netdev_upper_dev_unlink);
 void netdev_bonding_info_change(struct net_device *dev,
 				struct netdev_bonding_info *bonding_info)
 {
-	struct netdev_notifier_bonding_info	info;
+	struct netdev_notifier_bonding_info info = {
+		.info.dev = dev,
+	};
 
 	memcpy(&info.bonding_info, bonding_info,
 	       sizeof(struct netdev_bonding_info));
-	call_netdevice_notifiers_info(NETDEV_BONDING_INFO, dev,
+	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
 				      &info.info);
 }
 EXPORT_SYMBOL(netdev_bonding_info_change);
@@ -6535,11 +6550,13 @@ EXPORT_SYMBOL(dev_get_nest_level);
 void netdev_lower_state_changed(struct net_device *lower_dev,
 				void *lower_state_info)
 {
-	struct netdev_notifier_changelowerstate_info changelowerstate_info;
+	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
+		.info.dev = lower_dev,
+	};
 
 	ASSERT_RTNL();
 	changelowerstate_info.lower_state_info = lower_state_info;
-	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE, lower_dev,
+	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
 				      &changelowerstate_info.info);
 }
 EXPORT_SYMBOL(netdev_lower_state_changed);
@@ -6830,11 +6847,14 @@ void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
 
 	if (dev->flags & IFF_UP &&
 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
-		struct netdev_notifier_change_info change_info;
-
-		change_info.flags_changed = changes;
-		call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
-					      &change_info.info);
+		struct netdev_notifier_change_info change_info = {
+			.info = {
+				.dev = dev,
+			},
+			.flags_changed = changes,
+		};
+
+		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
 	}
 }
 

net/core/rtnetlink.c

@@ -1957,7 +1957,8 @@ static int do_setvfinfo(struct net_device *dev, struct nlattr **tb)
 	return err;
 }
 
-static int do_set_master(struct net_device *dev, int ifindex)
+static int do_set_master(struct net_device *dev, int ifindex,
+			 struct netlink_ext_ack *extack)
 {
 	struct net_device *upper_dev = netdev_master_upper_dev_get(dev);
 	const struct net_device_ops *ops;
@@ -1982,7 +1983,7 @@ static int do_set_master(struct net_device *dev, int ifindex)
 			return -EINVAL;
 		ops = upper_dev->netdev_ops;
 		if (ops->ndo_add_slave) {
-			err = ops->ndo_add_slave(upper_dev, dev);
+			err = ops->ndo_add_slave(upper_dev, dev, extack);
 			if (err)
 				return err;
 		} else {
@@ -2115,7 +2116,7 @@ static int do_setlink(const struct sk_buff *skb,
 	}
 
 	if (tb[IFLA_MASTER]) {
-		err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]));
+		err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
 		if (err)
 			goto errout;
 		status |= DO_SETLINK_MODIFIED;
@@ -2753,7 +2754,8 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 				goto out_unregister;
 		}
 		if (tb[IFLA_MASTER]) {
-			err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]));
+			err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]),
+					    extack);
 			if (err)
 				goto out_unregister;
 		}

net/openvswitch/vport-netdev.c

@@ -108,7 +108,8 @@ struct vport *ovs_netdev_link(struct vport *vport, const char *name)
 
 	rtnl_lock();
 	err = netdev_master_upper_dev_link(vport->dev,
-					   get_dpdev(vport->dp), NULL, NULL);
+					   get_dpdev(vport->dp),
+					   NULL, NULL, NULL);
 	if (err)
 		goto error_unlock;