[IPSEC] xfrm: Undo afinfo lock proliferation

The number of locks used to manage afinfo structures can easily be reduced
down to one each for policy and state respectively.  This is based on the
observation that the write locks are only held by module insertion/removal
which are very rare events so there is no need to further differentiate
between the insertion of modules like ipv6 versus esp6.

The removal of the read locks in xfrm4_policy.c/xfrm6_policy.c might look
suspicious at first.  However, after you realise that nobody ever takes
the corresponding write lock you'll feel better :)

As far as I can gather it's an attempt to guard against the removal of
the corresponding modules.  Since neither module can be unloaded at all
we can leave it to whoever fixes up IPv6 unloading :)

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 6 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 8604c747bca5..c0465284dfac 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -17,8 +17,6 @@
 static struct dst_ops xfrm4_dst_ops;
 static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
 
-static struct xfrm_type_map xfrm4_type_map = { .lock = RW_LOCK_UNLOCKED };
-
 static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
 {
         return __ip_route_output_key((struct rtable**)dst, fl);
@@ -237,9 +235,7 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl)
 
 static inline int xfrm4_garbage_collect(void)
 {
-        read_lock(&xfrm4_policy_afinfo.lock);
         xfrm4_policy_afinfo.garbage_collect();
-        read_unlock(&xfrm4_policy_afinfo.lock);
         return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
 }
 
@@ -299,8 +295,6 @@ static struct dst_ops xfrm4_dst_ops = {
 
 static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
         .family =               AF_INET,
-        .lock =                 RW_LOCK_UNLOCKED,
-        .type_map =             &xfrm4_type_map,
         .dst_ops =              &xfrm4_dst_ops,
         .dst_lookup =           xfrm4_dst_lookup,
         .find_bundle =          __xfrm4_find_bundle,