net: add adj_list to save only neighbours

Currently, we distinguish neighbours (first-level linked devices) from
non-neighbours by the neighbour bool in the netdev_adjacent. This could be
quite time-consuming in case we would like to traverse *only* through
neighbours - cause we'd have to traverse through all devices and check for
this flag, and in a (quite common) scenario where we have lots of vlans on
top of bridge, which is on top of a bond - the bonding would have to go
through all those vlans to get its upper neighbour linked devices.

This situation is really unpleasant, cause there are already a lot of cases
when a device with slaves needs to go through them in hot path.

To fix this, introduce a new upper/lower device lists structure -
adj_list, which contains only the neighbours. It works always in
pair with the all_adj_list structure (renamed from upper/lower_dev_list),
i.e. both of them contain the same links, only that all_adj_list contains
also non-neighbour device links. It's really a small change visible,
currently, only for __netdev_adjacent_dev_insert/remove(), and doesn't
change the main linked logic at all.

Also, add some comments a fix a name collision in
netdev_for_each_upper_dev_rcu() and rework the naming by the following
rules:

netdev_(all_)(upper|lower)_*

If "all_" is present, then we work with the whole list of upper/lower
devices, otherwise - only with direct neighbours. Uninline functions - to
get better stack traces.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 7 insertions, 5 deletions

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index f428ef57..8524e33 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -1019,7 +1019,7 @@ static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
 
 	/* loop through vlans and send one packet for each */
 	rcu_read_lock();
-	netdev_for_each_upper_dev_rcu(bond->dev, upper, iter) {
+	netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
 		if (upper->priv_flags & IFF_802_1Q_VLAN)
 			alb_send_lp_vid(slave, mac_addr,
 					vlan_dev_vlan_id(upper));
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 55bbb8b..91c4ab8 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2267,7 +2267,7 @@ static bool bond_has_this_ip(struct bonding *bond, __be32 ip)
 		return true;
 
 	rcu_read_lock();
-	netdev_for_each_upper_dev_rcu(bond->dev, upper, iter) {
+	netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
 		if (ip == bond_confirm_addr(upper, 0, ip)) {
 			ret = true;
 			break;
@@ -2342,10 +2342,12 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 		 *
 		 * TODO: QinQ?
 		 */
-		netdev_for_each_upper_dev_rcu(bond->dev, vlan_upper, vlan_iter) {
+		netdev_for_each_all_upper_dev_rcu(bond->dev, vlan_upper,
+						  vlan_iter) {
 			if (!is_vlan_dev(vlan_upper))
 				continue;
-			netdev_for_each_upper_dev_rcu(vlan_upper, upper, iter) {
+			netdev_for_each_all_upper_dev_rcu(vlan_upper, upper,
+							  iter) {
 				if (upper == rt->dst.dev) {
 					vlan_id = vlan_dev_vlan_id(vlan_upper);
 					rcu_read_unlock();
@@ -2358,7 +2360,7 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 		 * our upper vlans, then just search for any dev that
 		 * matches, and in case it's a vlan - save the id
 		 */
-		netdev_for_each_upper_dev_rcu(bond->dev, upper, iter) {
+		netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
 			if (upper == rt->dst.dev) {
 				/* if it's a vlan - get its VID */
 				if (is_vlan_dev(upper))