net neigh: RCU conversion of neigh hash table

David

This is the first step for RCU conversion of neigh code.

Next patches will convert hash_buckets[] and "struct neighbour" to RCU
protected objects.

Thanks

[PATCH net-next] net neigh: RCU conversion of neigh hash table

Instead of storing hash_buckets, hash_mask and hash_rnd in "struct
neigh_table", a new structure is defined :

struct neigh_hash_table {
       struct neighbour        **hash_buckets;
       unsigned int            hash_mask;
       __u32                   hash_rnd;
       struct rcu_head         rcu;
};

And "struct neigh_table" has an RCU protected pointer to such a
neigh_hash_table.

This means the signature of (*hash)() function changed: We need to add a
third parameter with the actual hash_rnd value, since this is not
anymore a neigh_table field.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>