Merge http://sucs.org/~rohan/git/gfs2-3.0-nmw

[pandora-kernel.git] / net / ipv4 / protocol.c

diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
index f2d2973..9ae5c01 100644 (file)
--- a/net/ipv4/protocol.c
+++ b/net/ipv4/protocol.c
@@ -28,8 +28,7 @@
 #include <linux/spinlock.h>
 #include <net/protocol.h>
 
-const struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp;
-static DEFINE_SPINLOCK(inet_proto_lock);
+const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
 
 /*
  *     Add a protocol handler to the hash tables
@@ -37,20 +36,10 @@ static DEFINE_SPINLOCK(inet_proto_lock);
 
 int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-       int hash, ret;
+       int hash = protocol & (MAX_INET_PROTOS - 1);
 
-       hash = protocol & (MAX_INET_PROTOS - 1);
-
-       spin_lock_bh(&inet_proto_lock);
-       if (inet_protos[hash]) {
-               ret = -1;
-       } else {
-               inet_protos[hash] = prot;
-               ret = 0;
-       }
-       spin_unlock_bh(&inet_proto_lock);
-
-       return ret;
+       return !cmpxchg((const struct net_protocol **)&inet_protos[hash],
+                       NULL, prot) ? 0 : -1;
 }
 EXPORT_SYMBOL(inet_add_protocol);
 
@@ -60,18 +49,10 @@ EXPORT_SYMBOL(inet_add_protocol);
 
 int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-       int hash, ret;
-
-       hash = protocol & (MAX_INET_PROTOS - 1);
+       int ret, hash = protocol & (MAX_INET_PROTOS - 1);
 
-       spin_lock_bh(&inet_proto_lock);
-       if (inet_protos[hash] == prot) {
-               inet_protos[hash] = NULL;
-               ret = 0;
-       } else {
-               ret = -1;
-       }
-       spin_unlock_bh(&inet_proto_lock);
+       ret = (cmpxchg((const struct net_protocol **)&inet_protos[hash],
+                      prot, NULL) == prot) ? 0 : -1;
 
        synchronize_net();