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authorSabrina Dubroca <sd@queasysnail.net>2016-08-12 16:10:33 +0200
committerDavid S. Miller <davem@davemloft.net>2016-08-13 15:15:54 -0700
commit952fcfd08c8109951622579d0ae7b9cd6cafd688 (patch)
tree16e787138d3da28899e3a0028962928c79a4af07
parente20038724552cd05e351cd7d7526d646953d26b7 (diff)
downloadlwn-952fcfd08c8109951622579d0ae7b9cd6cafd688.tar.gz
lwn-952fcfd08c8109951622579d0ae7b9cd6cafd688.zip
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>
-rw-r--r--drivers/net/macsec.c2
-rw-r--r--drivers/net/macvlan.c2
-rw-r--r--include/linux/netdevice.h3
-rw-r--r--net/8021q/vlan.c2
-rw-r--r--net/core/dev.c10
5 files changed, 7 insertions, 12 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,
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index cd9b53834bf6..3234fcdea317 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1315,7 +1315,7 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
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 076df5360ba5..3a788bf0affd 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3891,8 +3891,7 @@ void netdev_default_l2upper_neigh_destroy(struct net_device *dev,
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 82a116ba590e..8de138d3306b 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -169,7 +169,7 @@ int register_vlan_dev(struct net_device *dev)
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 4ce07dc25573..dd6ce598de89 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6045,8 +6045,7 @@ void *netdev_lower_dev_get_private(struct net_device *dev,
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 @@ int dev_get_nest_level(struct net_device *dev,
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);