From 31088a113c2a948856ed2047d8c21c217b13e85d Mon Sep 17 00:00:00 2001 From: Veaceslav Falico Date: Wed, 25 Sep 2013 09:20:12 +0200 Subject: [PATCH] net: add for_each iterators through neighbour lower link's private Add a possibility to iterate through netdev_adjacent's private, currently only for lower neighbours. Add both RCU and RTNL/other locking variants of iterators, and make the non-rcu variant to be safe from removal. CC: "David S. Miller" CC: Eric Dumazet CC: Jiri Pirko CC: Alexander Duyck Signed-off-by: Veaceslav Falico Signed-off-by: David S. Miller --- include/linux/netdevice.h | 17 +++++++++++ net/core/dev.c | 60 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 76 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 75d5beac463..168974e40cf 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2833,6 +2833,23 @@ extern struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *d updev; \ updev = netdev_all_upper_get_next_dev_rcu(dev, &(iter))) +extern void *netdev_lower_get_next_private(struct net_device *dev, + struct list_head **iter); +extern void *netdev_lower_get_next_private_rcu(struct net_device *dev, + struct list_head **iter); + +#define netdev_for_each_lower_private(dev, priv, iter) \ + for (iter = (dev)->adj_list.lower.next, \ + priv = netdev_lower_get_next_private(dev, &(iter)); \ + priv; \ + priv = netdev_lower_get_next_private(dev, &(iter))) + +#define netdev_for_each_lower_private_rcu(dev, priv, iter) \ + for (iter = &(dev)->adj_list.lower, \ + priv = netdev_lower_get_next_private_rcu(dev, &(iter)); \ + priv; \ + priv = netdev_lower_get_next_private_rcu(dev, &(iter))) + extern struct net_device *netdev_master_upper_dev_get(struct net_device *dev); extern struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev); extern int netdev_upper_dev_link(struct net_device *dev, diff --git a/net/core/dev.c b/net/core/dev.c index c69ab74fb20..0aa844aae40 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4466,7 +4466,8 @@ struct net_device *netdev_master_upper_dev_get(struct net_device *dev) } EXPORT_SYMBOL(netdev_master_upper_dev_get); -/* netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list +/** + * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list * @dev: device * @iter: list_head ** of the current position * @@ -4491,6 +4492,63 @@ struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev, } EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu); +/** + * netdev_lower_get_next_private - Get the next ->private from the + * lower neighbour list + * @dev: device + * @iter: list_head ** of the current position + * + * Gets the next netdev_adjacent->private from the dev's lower neighbour + * list, starting from iter position. The caller must hold either hold the + * RTNL lock or its own locking that guarantees that the neighbour lower + * list will remain unchainged. + */ +void *netdev_lower_get_next_private(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *lower; + + lower = list_entry(*iter, struct netdev_adjacent, list); + + if (&lower->list == &dev->adj_list.lower) + return NULL; + + if (iter) + *iter = lower->list.next; + + return lower->private; +} +EXPORT_SYMBOL(netdev_lower_get_next_private); + +/** + * netdev_lower_get_next_private_rcu - Get the next ->private from the + * lower neighbour list, RCU + * variant + * @dev: device + * @iter: list_head ** of the current position + * + * Gets the next netdev_adjacent->private from the dev's lower neighbour + * list, starting from iter position. The caller must hold RCU read lock. + */ +void *netdev_lower_get_next_private_rcu(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *lower; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); + + if (&lower->list == &dev->adj_list.lower) + return NULL; + + if (iter) + *iter = &lower->list; + + return lower->private; +} +EXPORT_SYMBOL(netdev_lower_get_next_private_rcu); + /** * netdev_master_upper_dev_get_rcu - Get master upper device * @dev: device -- 2.43.2