net: Find the nesting level of a given device by type.
Multiple devices in the kernel can be stacked/nested and they
need to know their nesting level for the purposes of lockdep.
This patch provides a generic function that determines a nesting
level of a particular device by its type (ex: vlan, macvlan, etc).
We only care about nesting of the same type of devices.
For example:
eth0 <- vlan0.10 <- macvlan0 <- vlan1.20
The nesting level of vlan1.20 would be 1, since there is another vlan
in the stack under it.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index ed928e8..6ee3ac2 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4623,6 +4623,32 @@
EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
/**
+ * netdev_lower_get_next - Get the next device from the lower neighbour
+ * list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold RTNL lock or
+ * its own locking that guarantees that the neighbour lower
+ * list will remain unchainged.
+ */
+void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
+{
+ struct netdev_adjacent *lower;
+
+ lower = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+ if (&lower->list == &dev->adj_list.lower)
+ return NULL;
+
+ *iter = &lower->list;
+
+ return lower->dev;
+}
+EXPORT_SYMBOL(netdev_lower_get_next);
+
+/**
* netdev_lower_get_first_private_rcu - Get the first ->private from the
* lower neighbour list, RCU
* variant
@@ -5072,6 +5098,30 @@
}
EXPORT_SYMBOL(netdev_lower_dev_get_private);
+
+int dev_get_nest_level(struct net_device *dev,
+ bool (*type_check)(struct net_device *dev))
+{
+ struct net_device *lower = NULL;
+ struct list_head *iter;
+ int max_nest = -1;
+ int nest;
+
+ ASSERT_RTNL();
+
+ netdev_for_each_lower_dev(dev, lower, iter) {
+ nest = dev_get_nest_level(lower, type_check);
+ if (max_nest < nest)
+ max_nest = nest;
+ }
+
+ if (type_check(dev))
+ max_nest++;
+
+ return max_nest;
+}
+EXPORT_SYMBOL(dev_get_nest_level);
+
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
const struct net_device_ops *ops = dev->netdev_ops;