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>
This commit is contained in:
Vlad Yasevich 2014-05-16 17:04:53 -04:00 committed by David S. Miller
parent 29e9824278
commit 4085ebe8c3
2 changed files with 60 additions and 0 deletions

View File

@ -3077,6 +3077,14 @@ void *netdev_lower_get_next_private_rcu(struct net_device *dev,
priv; \
priv = netdev_lower_get_next_private_rcu(dev, &(iter)))
void *netdev_lower_get_next(struct net_device *dev,
struct list_head **iter);
#define netdev_for_each_lower_dev(dev, ldev, iter) \
for (iter = &(dev)->adj_list.lower, \
ldev = netdev_lower_get_next(dev, &(iter)); \
ldev; \
ldev = netdev_lower_get_next(dev, &(iter)))
void *netdev_adjacent_get_private(struct list_head *adj_list);
void *netdev_lower_get_first_private_rcu(struct net_device *dev);
struct net_device *netdev_master_upper_dev_get(struct net_device *dev);
@ -3092,6 +3100,8 @@ void netdev_upper_dev_unlink(struct net_device *dev,
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname);
void *netdev_lower_dev_get_private(struct net_device *dev,
struct net_device *lower_dev);
int dev_get_nest_level(struct net_device *dev,
bool (*type_check)(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);

View File

@ -4622,6 +4622,32 @@ void *netdev_lower_get_next_private_rcu(struct net_device *dev,
}
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
@ -5072,6 +5098,30 @@ 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)(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;