@@ -91,6 +91,10 @@
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))
@@ -2869,6 +2869,7 @@ 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);
@@ -4570,6 +4570,27 @@ 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
*
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 <nikolay@redhat.com> Suggested-by: Jay Vosburgh <fubar@us.ibm.com> Suggested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> --- drivers/net/bonding/bonding.h | 4 ++++ include/linux/netdevice.h | 1 + net/core/dev.c | 21 +++++++++++++++++++++ 3 files changed, 26 insertions(+)