net: introduce upper device lists and remove dev->master

Jiri Pirko says:

====================
This is a V6 of a repost of my previous patchset:
"[patch net-next v2 00/15] net: introduce upper device lists and remove dev->master" from Aug 14

The discussion around
"[net-next] bonding: don't allow the master to become its slave"
forced me to think about upper<->lower device connections.

This patchset adds a possibility to record upper device linkage.
All upper<->lower devices are converted to use this mechanism right after.
That leads to dev->master removal because this info becomes redundant since
"master links" have the same value.

After all changes, there is no longer possible to do things as:
"bond->someotherdevice->samebond"

Also I think that drivers like cxgb3, qlcnic, qeth would benefit by this
in future by being able to get more appropriate info about l3 addresses.

v5->v6:
- netdev_has_upper_dev() - added statement to comment that this is looking at
  the immediate upper devices only.
- renamed "RTNL semaphore" -> "RTNL lock" in all comments
- renamed __netdev_has_upper_dev() to __netdev_search_upper_dev() to emhasize
  the difference to netdev_has_upper_dev()

v4->v5:
- fixed missed typo in drivers/infiniband/hw/nes/nes_cm.c

v3->v4:
- comments in __netdev_upper_dev_link() squashed into one line
- kfree_rcu used instead of call_rcu in netdev_upper_dev_unlink()

v2->v3:
- removed recursion in __netdev_has_upper_dev()
- refreshed bits to be applicable on current net-next

v1->v2:
- s/unique/master/ better naming + stays closer to the past
- fixed vlan err goto
- original patch 15 (WARN_ON change) is squashed into the first patch
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/infiniband/hw/nes/nes.c

@@ -135,6 +135,7 @@ static int nes_inetaddr_event(struct notifier_block *notifier,
 	struct net_device *event_netdev = ifa->ifa_dev->dev;
 	struct nes_device *nesdev;
 	struct net_device *netdev;
+	struct net_device *upper_dev;
 	struct nes_vnic *nesvnic;
 	unsigned int is_bonded;
 
@@ -145,8 +146,9 @@ static int nes_inetaddr_event(struct notifier_block *notifier,
 				nesdev, nesdev->netdev[0]->name);
 		netdev = nesdev->netdev[0];
 		nesvnic = netdev_priv(netdev);
+		upper_dev = netdev_master_upper_dev_get(netdev);
 		is_bonded = netif_is_bond_slave(netdev) &&
-			    (netdev->master == event_netdev);
+			    (upper_dev == event_netdev);
 		if ((netdev == event_netdev) || is_bonded) {
 			if (nesvnic->rdma_enabled == 0) {
 				nes_debug(NES_DBG_NETDEV, "Returning without processing event for %s since"
@@ -179,9 +181,9 @@ static int nes_inetaddr_event(struct notifier_block *notifier,
 					/* fall through */
 				case NETDEV_CHANGEADDR:
 					/* Add the address to the IP table */
-					if (netdev->master)
+					if (upper_dev)
 						nesvnic->local_ipaddr =
-							((struct in_device *)netdev->master->ip_ptr)->ifa_list->ifa_address;
+							((struct in_device *)upper_dev->ip_ptr)->ifa_list->ifa_address;
 					else
 						nesvnic->local_ipaddr = ifa->ifa_address;
 

drivers/infiniband/hw/nes/nes_cm.c

@@ -1340,7 +1340,7 @@ static int nes_addr_resolve_neigh(struct nes_vnic *nesvnic, u32 dst_ip, int arpi
 	}
 
 	if (netif_is_bond_slave(nesvnic->netdev))
-		netdev = nesvnic->netdev->master;
+		netdev = netdev_master_upper_dev_get(nesvnic->netdev);
 	else
 		netdev = nesvnic->netdev;
 

drivers/net/bonding/bond_3ad.c

@@ -1127,7 +1127,7 @@ static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
 				// INFO_RECEIVED_LOOPBACK_FRAMES
 				pr_err("%s: An illegal loopback occurred on adapter (%s).\n"
 				       "Check the configuration to verify that all adapters are connected to 802.3ad compliant switch ports\n",
-				       port->slave->dev->master->name, port->slave->dev->name);
+				       port->slave->bond->dev->name, port->slave->dev->name);
 				return;
 			}
 			__update_selected(lacpdu, port);
@@ -1306,7 +1306,7 @@ static void ad_port_selection_logic(struct port *port)
 		}
 		if (!curr_port) { // meaning: the port was related to an aggregator but was not on the aggregator port list
 			pr_warning("%s: Warning: Port %d (on %s) was related to aggregator %d but was not on its port list\n",
-				   port->slave->dev->master->name,
+				   port->slave->bond->dev->name,
 				   port->actor_port_number,
 				   port->slave->dev->name,
 				   port->aggregator->aggregator_identifier);
@@ -1386,7 +1386,7 @@ static void ad_port_selection_logic(struct port *port)
 				 port->aggregator->aggregator_identifier);
 		} else {
 			pr_err("%s: Port %d (on %s) did not find a suitable aggregator\n",
-			       port->slave->dev->master->name,
+			       port->slave->bond->dev->name,
 			       port->actor_port_number, port->slave->dev->name);
 		}
 	}
@@ -1463,7 +1463,7 @@ static struct aggregator *ad_agg_selection_test(struct aggregator *best,
 
 	default:
 		pr_warning("%s: Impossible agg select mode %d\n",
-			   curr->slave->dev->master->name,
+			   curr->slave->bond->dev->name,
 			   __get_agg_selection_mode(curr->lag_ports));
 		break;
 	}
@@ -1571,7 +1571,7 @@ static void ad_agg_selection_logic(struct aggregator *agg)
 		// check if any partner replys
 		if (best->is_individual) {
 			pr_warning("%s: Warning: No 802.3ad response from the link partner for any adapters in the bond\n",
-				   best->slave ? best->slave->dev->master->name : "NULL");
+				   best->slave ? best->slave->bond->dev->name : "NULL");
 		}
 
 		best->is_active = 1;
@@ -1898,7 +1898,7 @@ int bond_3ad_bind_slave(struct slave *slave)
 
 	if (bond == NULL) {
 		pr_err("%s: The slave %s is not attached to its bond\n",
-		       slave->dev->master->name, slave->dev->name);
+		       slave->bond->dev->name, slave->dev->name);
 		return -1;
 	}
 
@@ -1973,7 +1973,7 @@ void bond_3ad_unbind_slave(struct slave *slave)
 	// if slave is null, the whole port is not initialized
 	if (!port->slave) {
 		pr_warning("Warning: %s: Trying to unbind an uninitialized port on %s\n",
-			   slave->dev->master->name, slave->dev->name);
+			   slave->bond->dev->name, slave->dev->name);
 		return;
 	}
 
@@ -2009,7 +2009,7 @@ void bond_3ad_unbind_slave(struct slave *slave)
 
 				if ((new_aggregator->lag_ports == port) && new_aggregator->is_active) {
 					pr_info("%s: Removing an active aggregator\n",
-						aggregator->slave->dev->master->name);
+						aggregator->slave->bond->dev->name);
 					// select new active aggregator
 					 select_new_active_agg = 1;
 				}
@@ -2040,15 +2040,15 @@ void bond_3ad_unbind_slave(struct slave *slave)
 					ad_agg_selection_logic(__get_first_agg(port));
 			} else {
 				pr_warning("%s: Warning: unbinding aggregator, and could not find a new aggregator for its ports\n",
-					   slave->dev->master->name);
+					   slave->bond->dev->name);
 			}
 		} else { // in case that the only port related to this aggregator is the one we want to remove
 			select_new_active_agg = aggregator->is_active;
 			// clear the aggregator
 			ad_clear_agg(aggregator);
 			if (select_new_active_agg) {
 				pr_info("%s: Removing an active aggregator\n",
-					slave->dev->master->name);
+					slave->bond->dev->name);
 				// select new active aggregator
 				ad_agg_selection_logic(__get_first_agg(port));
 			}
@@ -2076,7 +2076,7 @@ void bond_3ad_unbind_slave(struct slave *slave)
 					ad_clear_agg(temp_aggregator);
 					if (select_new_active_agg) {
 						pr_info("%s: Removing an active aggregator\n",
-							slave->dev->master->name);
+							slave->bond->dev->name);
 						// select new active aggregator
 						ad_agg_selection_logic(__get_first_agg(port));
 					}
@@ -2184,7 +2184,7 @@ static int bond_3ad_rx_indication(struct lacpdu *lacpdu, struct slave *slave, u1
 
 		if (!port->slave) {
 			pr_warning("%s: Warning: port of slave %s is uninitialized\n",
-				   slave->dev->name, slave->dev->master->name);
+				   slave->dev->name, slave->bond->dev->name);
 			return ret;
 		}
 
@@ -2240,7 +2240,7 @@ void bond_3ad_adapter_speed_changed(struct slave *slave)
 	// if slave is null, the whole port is not initialized
 	if (!port->slave) {
 		pr_warning("Warning: %s: speed changed for uninitialized port on %s\n",
-			   slave->dev->master->name, slave->dev->name);
+			   slave->bond->dev->name, slave->dev->name);
 		return;
 	}
 
@@ -2268,7 +2268,7 @@ void bond_3ad_adapter_duplex_changed(struct slave *slave)
 	// if slave is null, the whole port is not initialized
 	if (!port->slave) {
 		pr_warning("%s: Warning: duplex changed for uninitialized port on %s\n",
-			   slave->dev->master->name, slave->dev->name);
+			   slave->bond->dev->name, slave->dev->name);
 		return;
 	}
 
@@ -2297,7 +2297,7 @@ void bond_3ad_handle_link_change(struct slave *slave, char link)
 	// if slave is null, the whole port is not initialized
 	if (!port->slave) {
 		pr_warning("Warning: %s: link status changed for uninitialized port on %s\n",
-			   slave->dev->master->name, slave->dev->name);
+			   slave->bond->dev->name, slave->dev->name);
 		return;
 	}
 

drivers/net/bonding/bond_alb.c

@@ -507,7 +507,7 @@ static void rlb_update_client(struct rlb_client_info *client_info)
 				 client_info->mac_dst);
 		if (!skb) {
 			pr_err("%s: Error: failed to create an ARP packet\n",
-			       client_info->slave->dev->master->name);
+			       client_info->slave->bond->dev->name);
 			continue;
 		}
 
@@ -517,7 +517,7 @@ static void rlb_update_client(struct rlb_client_info *client_info)
 			skb = vlan_put_tag(skb, client_info->vlan_id);
 			if (!skb) {
 				pr_err("%s: Error: failed to insert VLAN tag\n",
-				       client_info->slave->dev->master->name);
+				       client_info->slave->bond->dev->name);
 				continue;
 			}
 		}
@@ -1043,7 +1043,7 @@ static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[])
 	if (dev_set_mac_address(dev, &s_addr)) {
 		pr_err("%s: Error: dev_set_mac_address of dev %s failed!\n"
 		       "ALB mode requires that the base driver support setting the hw address also when the network device's interface is open\n",
-		       dev->master->name, dev->name);
+		       slave->bond->dev->name, dev->name);
 		return -EOPNOTSUPP;
 	}
 	return 0;