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>
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 7d08fd1..37845da 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -138,13 +138,22 @@
* neighbour table manipulation
*/
+struct neigh_hash_table {
+ struct neighbour **hash_buckets;
+ unsigned int hash_mask;
+ __u32 hash_rnd;
+ struct rcu_head rcu;
+};
+
struct neigh_table {
struct neigh_table *next;
int family;
int entry_size;
int key_len;
- __u32 (*hash)(const void *pkey, const struct net_device *);
+ __u32 (*hash)(const void *pkey,
+ const struct net_device *dev,
+ __u32 hash_rnd);
int (*constructor)(struct neighbour *);
int (*pconstructor)(struct pneigh_entry *);
void (*pdestructor)(struct pneigh_entry *);
@@ -165,9 +174,7 @@
unsigned long last_rand;
struct kmem_cache *kmem_cachep;
struct neigh_statistics __percpu *stats;
- struct neighbour **hash_buckets;
- unsigned int hash_mask;
- __u32 hash_rnd;
+ struct neigh_hash_table __rcu *nht;
struct pneigh_entry **phash_buckets;
};
@@ -237,6 +244,7 @@
struct neigh_seq_state {
struct seq_net_private p;
struct neigh_table *tbl;
+ struct neigh_hash_table *nht;
void *(*neigh_sub_iter)(struct neigh_seq_state *state,
struct neighbour *n, loff_t *pos);
unsigned int bucket;