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Commit 4085ebe8 authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

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: default avatarVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 29e98242

include/linux/netdevice.h

+10 −0
Original line number Diff line number Diff line
@@ -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);

net/core/dev.c

+50 −0
Original line number Diff line number Diff line
@@ -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;