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>

1 files changed, 7 insertions, 6 deletions

diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index 0363bb95cc7d..a085dbcf5c7f 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -48,7 +48,6 @@
 #include <net/dn_neigh.h>
 #include <net/dn_route.h>
 
-static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev);
 static int dn_neigh_construct(struct neighbour *);
 static void dn_long_error_report(struct neighbour *, struct sk_buff *);
 static void dn_short_error_report(struct neighbour *, struct sk_buff *);
@@ -93,6 +92,13 @@ static const struct neigh_ops dn_phase3_ops = {
         .queue_xmit =           dev_queue_xmit
 };
 
+static u32 dn_neigh_hash(const void *pkey,
+                         const struct net_device *dev,
+                         __u32 hash_rnd)
+{
+        return jhash_2words(*(__u16 *)pkey, 0, hash_rnd);
+}
+
 struct neigh_table dn_neigh_table = {
         .family =                       PF_DECnet,
         .entry_size =                   sizeof(struct dn_neigh),
@@ -122,11 +128,6 @@ struct neigh_table dn_neigh_table = {
         .gc_thresh3 =                   1024,
 };
 
-static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
-{
-        return jhash_2words(*(__u16 *)pkey, 0, dn_neigh_table.hash_rnd);
-}
-
 static int dn_neigh_construct(struct neighbour *neigh)
 {
         struct net_device *dev = neigh->dev;