IPv6: convert addrconf hash list to RCU

Convert from reader/writer lock to RCU and spinlock for addrconf
hash list.

Adds an additional helper macro for hlist_for_each_entry_continue_rcu
to handle the continue case.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 2c9b46cff3d7..004908b104d5 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -428,5 +428,18 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev,
                 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
                 pos = rcu_dereference_raw(pos->next))
 
+/**
+ * hlist_for_each_entry_continue_rcu - iterate over a hlist continuing after current point
+ * @tpos:       the type * to use as a loop cursor.
+ * @pos:        the &struct hlist_node to use as a loop cursor.
+ * @member:     the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue_rcu(tpos, pos, member)            \
+        for (pos = rcu_dereference((pos)->next);                        \
+             pos && ({ prefetch(pos->next); 1; }) &&                    \
+             ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; });  \
+             pos = rcu_dereference(pos->next))
+
+
 #endif  /* __KERNEL__ */
 #endif
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 498401541519..22a00b1d2c38 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -64,6 +64,7 @@ struct inet6_ifaddr {
 #endif
 
         int                     dead;
+        struct rcu_head         rcu;
 };
 
 struct ip6_sf_socklist {