From 48311f46853c0361f9fba7e0e6bb1652d633c049 Mon Sep 17 00:00:00 2001 From: Veaceslav Falico Date: Wed, 28 Aug 2013 23:25:07 +0200 Subject: [PATCH] net: add netdev_upper_get_next_dev_rcu(dev, iter) This function returns the next dev in the dev->upper_dev_list after the struct list_head **iter position, and updates *iter accordingly. Returns NULL if there are no devices left. Caller must hold RCU read lock. CC: "David S. Miller" CC: Eric Dumazet CC: Jiri Pirko CC: Alexander Duyck CC: Cong Wang Signed-off-by: Veaceslav Falico Signed-off-by: David S. Miller --- net/core/dev.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 749925a040a4..6fbb0c90849b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4468,6 +4468,31 @@ struct net_device *netdev_master_upper_dev_get(struct net_device *dev) } EXPORT_SYMBOL(netdev_master_upper_dev_get); +/* netdev_upper_get_next_dev_rcu - Get the next dev from upper list + * @dev: device + * @iter: list_head ** of the current position + * + * Gets the next device from the dev's upper list, starting from iter + * position. The caller must hold RCU read lock. + */ +struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *upper; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); + + if (&upper->list == &dev->upper_dev_list) + return NULL; + + *iter = &upper->list; + + return upper->dev; +} +EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu); + /** * netdev_master_upper_dev_get_rcu - Get master upper device * @dev: device -- 2.20.1