ipv6: mcast: RCU conversion

ipv6_sk_mc_lock rwlock becomes a spinlock.

readers (inet6_mc_check()) now takes rcu_read_lock() instead of read
lock. Writers dont need to disable BH anymore.

struct ipv6_mc_socklist objects are reclaimed after one RCU grace
period.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index f95ff8d9aa47..04977eefb0ee 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -89,10 +89,11 @@ struct ip6_sf_socklist {
 struct ipv6_mc_socklist {
         struct in6_addr         addr;
         int                     ifindex;
-        struct ipv6_mc_socklist *next;
+        struct ipv6_mc_socklist __rcu *next;
         rwlock_t                sflock;
         unsigned int            sfmode;         /* MCAST_{INCLUDE,EXCLUDE} */
         struct ip6_sf_socklist  *sflist;
+        struct rcu_head         rcu;
 };
 
 struct ip6_sf_list {