net: remove type_check from dev_get_nest_level()

The idea for type_check in dev_get_nest_level() was to count the number
of nested devices of the same type (currently, only macvlan or vlan
devices).
This prevented the false positive lockdep warning on configurations such
as:

eth0 <--- macvlan0 <--- vlan0 <--- macvlan1

However, this doesn't prevent a warning on a configuration such as:

eth0 <--- macvlan0 <--- vlan0
eth1 <--- vlan1 <--- macvlan1

In this case, all the locks end up with a nesting subclass of 1, so
lockdep thinks that there is still a deadlock:

- in the first case we have (macvlan_netdev_addr_lock_key, 1) and then
  take (vlan_netdev_xmit_lock_key, 1)
- in the second case, we have (vlan_netdev_xmit_lock_key, 1) and then
  take (macvlan_netdev_addr_lock_key, 1)

By removing the linktype check in dev_get_nest_level() and always
incrementing the nesting depth, lockdep considers this configuration
valid.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 2043e8c97a81..351e701eb043 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3201,7 +3201,7 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
 	dev_hold(real_dev);
 
-	macsec->nest_level = dev_get_nest_level(real_dev, netif_is_macsec) + 1;
+	macsec->nest_level = dev_get_nest_level(real_dev) + 1;
 	netdev_lockdep_set_classes(dev);
 	lockdep_set_class_and_subclass(&dev->addr_list_lock,
 				       &macsec_netdev_addr_lock_key,