igmp: RCU conversion of in_dev->mc_list
in_dev->mc_list is protected by one rwlock (in_dev->mc_list_lock).
This can easily be converted to a RCU protection.
Writers hold RTNL, so mc_list_lock is removed, not replaced by a
spinlock.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Cypher Wu <cypher.w@gmail.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index ccd5b07..380ba6b 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -52,9 +52,8 @@
atomic_t refcnt;
int dead;
struct in_ifaddr *ifa_list; /* IP ifaddr chain */
- rwlock_t mc_list_lock;
- struct ip_mc_list *mc_list; /* IP multicast filter chain */
- int mc_count; /* Number of installed mcasts */
+ struct ip_mc_list __rcu *mc_list; /* IP multicast filter chain */
+ int mc_count; /* Number of installed mcasts */
spinlock_t mc_tomb_lock;
struct ip_mc_list *mc_tomb;
unsigned long mr_v1_seen;