netdev: add netdev_continue_rcu

This adds an RCU macro for continuing search, useful for some
network devices like vlan.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 465add6c43e3..083b5989cecb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1079,6 +1079,8 @@ extern rwlock_t				dev_base_lock;		/* Device list lock */
                 list_for_each_entry_safe(d, n, &(net)->dev_base_head, dev_list)
 #define for_each_netdev_continue(net, d)                \
                 list_for_each_entry_continue(d, &(net)->dev_base_head, dev_list)
+#define for_each_netdev_continue_rcu(net, d)            \
+        list_for_each_entry_continue_rcu(d, &(net)->dev_base_head, dev_list)
 #define net_device_entry(lh)    list_entry(lh, struct net_device, dev_list)
 
 static inline struct net_device *next_net_device(struct net_device *dev)
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 5710f43bbc9e..1bf0f708c4fc 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -262,6 +262,20 @@ static inline void list_splice_init_rcu(struct list_head *list,
                 (pos) = rcu_dereference((pos)->next))
 
 /**
+ * list_for_each_entry_continue_rcu - continue iteration over list of given type
+ * @pos:        the type * to use as a loop cursor.
+ * @head:       the head for your list.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * Continue to iterate over list of given type, continuing after
+ * the current position.
+ */
+#define list_for_each_entry_continue_rcu(pos, head, member)             \
+        for (pos = list_entry_rcu(pos->member.next, typeof(*pos), member); \
+             prefetch(pos->member.next), &pos->member != (head);        \
+             pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
+
+/**
  * hlist_del_rcu - deletes entry from hash list without re-initialization
  * @n: the element to delete from the hash list.
  *