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>
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 2043e8c..351e701 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3201,7 +3201,7 @@
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,
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index cd9b538..3234fcd 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1315,7 +1315,7 @@
vlan->dev = dev;
vlan->port = port;
vlan->set_features = MACVLAN_FEATURES;
- vlan->nest_level = dev_get_nest_level(lowerdev, netif_is_macvlan) + 1;
+ vlan->nest_level = dev_get_nest_level(lowerdev) + 1;
vlan->mode = MACVLAN_MODE_VEPA;
if (data && data[IFLA_MACVLAN_MODE])
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 076df53..3a788bf 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3891,8 +3891,7 @@
extern u8 netdev_rss_key[NETDEV_RSS_KEY_LEN] __read_mostly;
void netdev_rss_key_fill(void *buffer, size_t len);
-int dev_get_nest_level(struct net_device *dev,
- bool (*type_check)(const struct net_device *dev));
+int dev_get_nest_level(struct net_device *dev);
int skb_checksum_help(struct sk_buff *skb);
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
netdev_features_t features, bool tx_path);
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 82a116b..8de138d 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -169,7 +169,7 @@
if (err < 0)
goto out_uninit_mvrp;
- vlan->nest_level = dev_get_nest_level(real_dev, is_vlan_dev) + 1;
+ vlan->nest_level = dev_get_nest_level(real_dev) + 1;
err = register_netdevice(dev);
if (err < 0)
goto out_uninit_mvrp;
diff --git a/net/core/dev.c b/net/core/dev.c
index 4ce07dc..dd6ce59 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6045,8 +6045,7 @@
EXPORT_SYMBOL(netdev_lower_dev_get_private);
-int dev_get_nest_level(struct net_device *dev,
- bool (*type_check)(const struct net_device *dev))
+int dev_get_nest_level(struct net_device *dev)
{
struct net_device *lower = NULL;
struct list_head *iter;
@@ -6056,15 +6055,12 @@
ASSERT_RTNL();
netdev_for_each_lower_dev(dev, lower, iter) {
- nest = dev_get_nest_level(lower, type_check);
+ nest = dev_get_nest_level(lower);
if (max_nest < nest)
max_nest = nest;
}
- if (type_check(dev))
- max_nest++;
-
- return max_nest;
+ return max_nest + 1;
}
EXPORT_SYMBOL(dev_get_nest_level);