This patch moves common code between rht_ptr and rht_ptr_exclusive
into __rht_ptr. It also adds a new helper rht_ptr_rcu exclusively
for the RCU case. This way rht_ptr becomes a lock-only construct
so we can use the lighter rcu_dereference_protected primitive.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>