From e001bfad913bf119fb67c1e8dd2d4ec1f5d392fa Mon Sep 17 00:00:00 2001 From: dingtianhong Date: Fri, 13 Dec 2013 10:19:55 +0800 Subject: [PATCH] bonding: create bond_first_slave_rcu() The bond_first_slave_rcu() will be used to instead of bond_first_slave() in rcu_read_lock(). According to the Jay Vosburgh's suggestion, the struct netdev_adjacent should hide from users who wanted to use it directly. so I package a new function to get the first slave of the bond. Suggested-by: Nikolay Aleksandrov Suggested-by: Jay Vosburgh Suggested-by: Veaceslav Falico Signed-off-by: Ding Tianhong Signed-off-by: David S. Miller --- drivers/net/bonding/bonding.h | 4 ++++ include/linux/netdevice.h | 1 + net/core/dev.c | 21 +++++++++++++++++++++ 3 files changed, 26 insertions(+) diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h index 8283cbdec50a..8f0d6d0c383b 100644 --- a/drivers/net/bonding/bonding.h +++ b/drivers/net/bonding/bonding.h @@ -101,6 +101,10 @@ netdev_adjacent_get_private(bond_slave_list(bond)->prev) : \ NULL) +/* Caller must have rcu_read_lock */ +#define bond_first_slave_rcu(bond) \ + netdev_lower_get_first_private_rcu(bond->dev) + #define bond_is_first_slave(bond, pos) (pos == bond_first_slave(bond)) #define bond_is_last_slave(bond, pos) (pos == bond_last_slave(bond)) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 5260d2eae2e6..2c74d20dad34 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2907,6 +2907,7 @@ void *netdev_lower_get_next_private_rcu(struct net_device *dev, priv = netdev_lower_get_next_private_rcu(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); struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev); int netdev_upper_dev_link(struct net_device *dev, struct net_device *upper_dev); diff --git a/net/core/dev.c b/net/core/dev.c index c95d664b2b42..9d4369ece679 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4543,6 +4543,27 @@ void *netdev_lower_get_next_private_rcu(struct net_device *dev, } EXPORT_SYMBOL(netdev_lower_get_next_private_rcu); +/** + * netdev_lower_get_first_private_rcu - Get the first ->private from the + * lower neighbour list, RCU + * variant + * @dev: device + * + * Gets the first netdev_adjacent->private from the dev's lower neighbour + * list. The caller must hold RCU read lock. + */ +void *netdev_lower_get_first_private_rcu(struct net_device *dev) +{ + struct netdev_adjacent *lower; + + lower = list_first_or_null_rcu(&dev->adj_list.lower, + struct netdev_adjacent, list); + if (lower) + return lower->private; + return NULL; +} +EXPORT_SYMBOL(netdev_lower_get_first_private_rcu); + /** * netdev_master_upper_dev_get_rcu - Get master upper device * @dev: device -- 2.20.1