From 4085ebe8c31face855fd01ee40372cb4aab1df3a Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 16 May 2014 17:04:53 -0400 Subject: 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 Signed-off-by: David S. Miller --- net/core/dev.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index ed928e846559..6ee3ac25ed72 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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; -- cgit v1.2.3-59-g8ed1b