ipv6 anycast: Convert ipv6_sk_ac_lock to spinlock.

Since all users are write-lock, it does not make sense to use
rwlock here.  Use simple spinlock.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 757a810d8f15a5270bbcdf1f734768371d892e73..921b8b398a8caa4cc3cbc562957a7285a88069b0 100644 (file)
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -47,7 +47,7 @@
 static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
 
 /* Big ac list lock for all the sockets */
-static DEFINE_RWLOCK(ipv6_sk_ac_lock);
+static DEFINE_SPINLOCK(ipv6_sk_ac_lock);
 
 
 /*
@@ -128,10 +128,10 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 
        err = ipv6_dev_ac_inc(dev, addr);
        if (!err) {
-               write_lock_bh(&ipv6_sk_ac_lock);
+               spin_lock_bh(&ipv6_sk_ac_lock);
                pac->acl_next = np->ipv6_ac_list;
                np->ipv6_ac_list = pac;
-               write_unlock_bh(&ipv6_sk_ac_lock);
+               spin_unlock_bh(&ipv6_sk_ac_lock);
                pac = NULL;
        }
 
@@ -152,7 +152,7 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
        struct ipv6_ac_socklist *pac, *prev_pac;
        struct net *net = sock_net(sk);
 
-       write_lock_bh(&ipv6_sk_ac_lock);
+       spin_lock_bh(&ipv6_sk_ac_lock);
        prev_pac = NULL;
        for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
                if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
@@ -161,7 +161,7 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
                prev_pac = pac;
        }
        if (!pac) {
-               write_unlock_bh(&ipv6_sk_ac_lock);
+               spin_unlock_bh(&ipv6_sk_ac_lock);
                return -ENOENT;
        }
        if (prev_pac)
@@ -169,7 +169,7 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
        else
                np->ipv6_ac_list = pac->acl_next;
 
-       write_unlock_bh(&ipv6_sk_ac_lock);
+       spin_unlock_bh(&ipv6_sk_ac_lock);
 
        rcu_read_lock();
        dev = dev_get_by_index_rcu(net, pac->acl_ifindex);
@@ -192,10 +192,10 @@ void ipv6_sock_ac_close(struct sock *sk)
        if (!np->ipv6_ac_list)
                return;
 
-       write_lock_bh(&ipv6_sk_ac_lock);
+       spin_lock_bh(&ipv6_sk_ac_lock);
        pac = np->ipv6_ac_list;
        np->ipv6_ac_list = NULL;
-       write_unlock_bh(&ipv6_sk_ac_lock);
+       spin_unlock_bh(&ipv6_sk_ac_lock);
 
        prev_index = 0;
        rcu_read_lock();