udp: secondary hash on (local port, local address)
Extends udp_table to contain a secondary hash table.
socket anchor for this second hash is free, because UDP
doesnt use skc_bind_node : We define an union to hold
both skc_bind_node & a new hlist_nulls_node udp_portaddr_node
udp_lib_get_port() inserts sockets into second hash chain
(additional cost of one atomic op)
udp_lib_unhash() deletes socket from second hash chain
(additional cost of one atomic op)
Note : No spinlock lockdep annotation is needed, because
lock for the secondary hash chain is always get after
lock for primary hash chain.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index af72de1..5f04216 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -163,7 +163,7 @@
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2))
{
- struct udp_hslot *hslot;
+ struct udp_hslot *hslot, *hslot2;
struct udp_table *udptable = sk->sk_prot->h.udp_table;
int error = 1;
struct net *net = sock_net(sk);
@@ -222,6 +222,13 @@
sk_nulls_add_node_rcu(sk, &hslot->head);
hslot->count++;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+
+ hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
+ spin_lock(&hslot2->lock);
+ hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
+ &hslot2->head);
+ hslot2->count++;
+ spin_unlock(&hslot2->lock);
}
error = 0;
fail_unlock:
@@ -1062,14 +1069,22 @@
{
if (sk_hashed(sk)) {
struct udp_table *udptable = sk->sk_prot->h.udp_table;
- struct udp_hslot *hslot = udp_hashslot(udptable, sock_net(sk),
- udp_sk(sk)->udp_port_hash);
+ struct udp_hslot *hslot, *hslot2;
+
+ hslot = udp_hashslot(udptable, sock_net(sk),
+ udp_sk(sk)->udp_port_hash);
+ hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
spin_lock_bh(&hslot->lock);
if (sk_nulls_del_node_init_rcu(sk)) {
hslot->count--;
inet_sk(sk)->inet_num = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+
+ spin_lock(&hslot2->lock);
+ hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
+ hslot2->count--;
+ spin_unlock(&hslot2->lock);
}
spin_unlock_bh(&hslot->lock);
}
@@ -1857,7 +1872,7 @@
if (!CONFIG_BASE_SMALL)
table->hash = alloc_large_system_hash(name,
- sizeof(struct udp_hslot),
+ 2 * sizeof(struct udp_hslot),
uhash_entries,
21, /* one slot per 2 MB */
0,
@@ -1869,17 +1884,23 @@
*/
if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
- sizeof(struct udp_hslot), GFP_KERNEL);
+ 2 * sizeof(struct udp_hslot), GFP_KERNEL);
if (!table->hash)
panic(name);
table->log = ilog2(UDP_HTABLE_SIZE_MIN);
table->mask = UDP_HTABLE_SIZE_MIN - 1;
}
+ table->hash2 = table->hash + (table->mask + 1);
for (i = 0; i <= table->mask; i++) {
INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
table->hash[i].count = 0;
spin_lock_init(&table->hash[i].lock);
}
+ for (i = 0; i <= table->mask; i++) {
+ INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
+ table->hash2[i].count = 0;
+ spin_lock_init(&table->hash2[i].lock);
+ }
}
void __init udp_init(void)