[INET]: Generalise the tcp_listen_ lock routines
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index da07411..f5d6512 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -19,10 +19,14 @@
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
+#include <linux/tcp.h> /* only for TCP_LISTEN, damn :-( */
#include <linux/types.h>
+#include <linux/wait.h>
#include <net/sock.h>
+#include <asm/atomic.h>
+
/* This is for all connections with a full identity, no wildcards.
* New scheme, half the table is for TIME_WAIT, the other half is
* for the rest. I'll experiment with dynamic table growth later.
@@ -192,4 +196,48 @@
extern void inet_put_port(struct inet_hashinfo *table, struct sock *sk);
+extern void inet_listen_wlock(struct inet_hashinfo *hashinfo);
+
+/*
+ * - We may sleep inside this lock.
+ * - If sleeping is not required (or called from BH),
+ * use plain read_(un)lock(&inet_hashinfo.lhash_lock).
+ */
+static inline void inet_listen_lock(struct inet_hashinfo *hashinfo)
+{
+ /* read_lock synchronizes to candidates to writers */
+ read_lock(&hashinfo->lhash_lock);
+ atomic_inc(&hashinfo->lhash_users);
+ read_unlock(&hashinfo->lhash_lock);
+}
+
+static inline void inet_listen_unlock(struct inet_hashinfo *hashinfo)
+{
+ if (atomic_dec_and_test(&hashinfo->lhash_users))
+ wake_up(&hashinfo->lhash_wait);
+}
+
+static inline void __inet_hash(struct inet_hashinfo *hashinfo,
+ struct sock *sk, const int listen_possible)
+{
+ struct hlist_head *list;
+ rwlock_t *lock;
+
+ BUG_TRAP(sk_unhashed(sk));
+ if (listen_possible && sk->sk_state == TCP_LISTEN) {
+ list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
+ lock = &hashinfo->lhash_lock;
+ inet_listen_wlock(hashinfo);
+ } else {
+ sk->sk_hashent = inet_sk_ehashfn(sk, hashinfo->ehash_size);
+ list = &hashinfo->ehash[sk->sk_hashent].chain;
+ lock = &hashinfo->ehash[sk->sk_hashent].lock;
+ write_lock(lock);
+ }
+ __sk_add_node(sk, list);
+ sock_prot_inc_use(sk->sk_prot);
+ write_unlock(lock);
+ if (listen_possible && sk->sk_state == TCP_LISTEN)
+ wake_up(&hashinfo->lhash_wait);
+}
#endif /* _INET_HASHTABLES_H */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 99e4769..bc110cc 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1447,27 +1447,6 @@
extern void tcp_enter_memory_pressure(void);
-extern void tcp_listen_wlock(void);
-
-/* - We may sleep inside this lock.
- * - If sleeping is not required (or called from BH),
- * use plain read_(un)lock(&inet_hashinfo.lhash_lock).
- */
-
-static inline void tcp_listen_lock(void)
-{
- /* read_lock synchronizes to candidates to writers */
- read_lock(&tcp_hashinfo.lhash_lock);
- atomic_inc(&tcp_hashinfo.lhash_users);
- read_unlock(&tcp_hashinfo.lhash_lock);
-}
-
-static inline void tcp_listen_unlock(void)
-{
- if (atomic_dec_and_test(&tcp_hashinfo.lhash_users))
- wake_up(&tcp_hashinfo.lhash_wait);
-}
-
static inline int keepalive_intvl_when(const struct tcp_sock *tp)
{
return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 33d6cbe..06cbc6f 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -15,7 +15,9 @@
#include <linux/config.h>
#include <linux/module.h>
+#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/wait.h>
#include <net/inet_hashtables.h>
@@ -89,3 +91,33 @@
}
EXPORT_SYMBOL(inet_put_port);
+
+/*
+ * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines (wake up each
+ * exclusive lock release). It should be ifdefed really.
+ */
+void inet_listen_wlock(struct inet_hashinfo *hashinfo)
+{
+ write_lock(&hashinfo->lhash_lock);
+
+ if (atomic_read(&hashinfo->lhash_users)) {
+ DEFINE_WAIT(wait);
+
+ for (;;) {
+ prepare_to_wait_exclusive(&hashinfo->lhash_wait,
+ &wait, TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&hashinfo->lhash_users))
+ break;
+ write_unlock_bh(&hashinfo->lhash_lock);
+ schedule();
+ write_lock_bh(&hashinfo->lhash_lock);
+ }
+
+ finish_wait(&hashinfo->lhash_wait, &wait);
+ }
+}
+
+EXPORT_SYMBOL(inet_listen_wlock);
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 0ae738b..1a89a03 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -589,7 +589,7 @@
if (cb->args[0] == 0) {
if (!(r->tcpdiag_states&(TCPF_LISTEN|TCPF_SYN_RECV)))
goto skip_listen_ht;
- tcp_listen_lock();
+ inet_listen_lock(&tcp_hashinfo);
for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
struct sock *sk;
struct hlist_node *node;
@@ -613,7 +613,7 @@
goto syn_recv;
if (tcpdiag_dump_sock(skb, sk, cb) < 0) {
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
goto done;
}
@@ -622,7 +622,7 @@
goto next_listen;
if (tcpdiag_dump_reqs(skb, sk, cb) < 0) {
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
goto done;
}
@@ -636,7 +636,7 @@
cb->args[3] = 0;
cb->args[4] = 0;
}
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
skip_listen_ht:
cb->args[0] = 1;
s_i = num = s_num = 0;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f5373f9..5f9ad95 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -228,62 +228,11 @@
return ret;
}
-/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
- * Look, when several writers sleep and reader wakes them up, all but one
- * immediately hit write lock and grab all the cpus. Exclusive sleep solves
- * this, _but_ remember, it adds useless work on UP machines (wake up each
- * exclusive lock release). It should be ifdefed really.
- */
-
-void tcp_listen_wlock(void)
-{
- write_lock(&tcp_hashinfo.lhash_lock);
-
- if (atomic_read(&tcp_hashinfo.lhash_users)) {
- DEFINE_WAIT(wait);
-
- for (;;) {
- prepare_to_wait_exclusive(&tcp_hashinfo.lhash_wait,
- &wait, TASK_UNINTERRUPTIBLE);
- if (!atomic_read(&tcp_hashinfo.lhash_users))
- break;
- write_unlock_bh(&tcp_hashinfo.lhash_lock);
- schedule();
- write_lock_bh(&tcp_hashinfo.lhash_lock);
- }
-
- finish_wait(&tcp_hashinfo.lhash_wait, &wait);
- }
-}
-
-static __inline__ void __tcp_v4_hash(struct sock *sk, const int listen_possible)
-{
- struct hlist_head *list;
- rwlock_t *lock;
-
- BUG_TRAP(sk_unhashed(sk));
- if (listen_possible && sk->sk_state == TCP_LISTEN) {
- list = &tcp_hashinfo.listening_hash[inet_sk_listen_hashfn(sk)];
- lock = &tcp_hashinfo.lhash_lock;
- tcp_listen_wlock();
- } else {
- sk->sk_hashent = inet_sk_ehashfn(sk, tcp_hashinfo.ehash_size);
- list = &tcp_hashinfo.ehash[sk->sk_hashent].chain;
- lock = &tcp_hashinfo.ehash[sk->sk_hashent].lock;
- write_lock(lock);
- }
- __sk_add_node(sk, list);
- sock_prot_inc_use(sk->sk_prot);
- write_unlock(lock);
- if (listen_possible && sk->sk_state == TCP_LISTEN)
- wake_up(&tcp_hashinfo.lhash_wait);
-}
-
static void tcp_v4_hash(struct sock *sk)
{
if (sk->sk_state != TCP_CLOSE) {
local_bh_disable();
- __tcp_v4_hash(sk, 1);
+ __inet_hash(&tcp_hashinfo, sk, 1);
local_bh_enable();
}
}
@@ -297,7 +246,7 @@
if (sk->sk_state == TCP_LISTEN) {
local_bh_disable();
- tcp_listen_wlock();
+ inet_listen_wlock(&tcp_hashinfo);
lock = &tcp_hashinfo.lhash_lock;
} else {
struct inet_ehash_bucket *head = &tcp_hashinfo.ehash[sk->sk_hashent];
@@ -624,7 +573,7 @@
inet_bind_hash(sk, tb, port);
if (sk_unhashed(sk)) {
inet_sk(sk)->sport = htons(port);
- __tcp_v4_hash(sk, 0);
+ __inet_hash(&tcp_hashinfo, sk, 0);
}
spin_unlock(&head->lock);
@@ -641,7 +590,7 @@
tb = inet_sk(sk)->bind_hash;
spin_lock_bh(&head->lock);
if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
- __tcp_v4_hash(sk, 0);
+ __inet_hash(&tcp_hashinfo, sk, 0);
spin_unlock_bh(&head->lock);
return 0;
} else {
@@ -1479,7 +1428,7 @@
newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
tcp_initialize_rcv_mss(newsk);
- __tcp_v4_hash(newsk, 0);
+ __inet_hash(&tcp_hashinfo, newsk, 0);
__inet_inherit_port(&tcp_hashinfo, sk, newsk);
return newsk;
@@ -2102,12 +2051,12 @@
void *rc;
struct tcp_iter_state* st = seq->private;
- tcp_listen_lock();
+ inet_listen_lock(&tcp_hashinfo);
st->state = TCP_SEQ_STATE_LISTENING;
rc = listening_get_idx(seq, &pos);
if (!rc) {
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
local_bh_disable();
st->state = TCP_SEQ_STATE_ESTABLISHED;
rc = established_get_idx(seq, pos);
@@ -2140,7 +2089,7 @@
case TCP_SEQ_STATE_LISTENING:
rc = listening_get_next(seq, v);
if (!rc) {
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
local_bh_disable();
st->state = TCP_SEQ_STATE_ESTABLISHED;
rc = established_get_first(seq);
@@ -2168,7 +2117,7 @@
}
case TCP_SEQ_STATE_LISTENING:
if (v != SEQ_START_TOKEN)
- tcp_listen_unlock();
+ inet_listen_unlock(&tcp_hashinfo);
break;
case TCP_SEQ_STATE_TIME_WAIT:
case TCP_SEQ_STATE_ESTABLISHED:
@@ -2431,7 +2380,6 @@
EXPORT_SYMBOL(ipv4_specific);
EXPORT_SYMBOL(inet_bind_bucket_create);
EXPORT_SYMBOL(tcp_hashinfo);
-EXPORT_SYMBOL(tcp_listen_wlock);
EXPORT_SYMBOL(tcp_prot);
EXPORT_SYMBOL(tcp_unhash);
EXPORT_SYMBOL(tcp_v4_conn_request);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 362ef5a..93a66b9a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -229,7 +229,7 @@
if (sk->sk_state == TCP_LISTEN) {
list = &tcp_hashinfo.listening_hash[inet_sk_listen_hashfn(sk)];
lock = &tcp_hashinfo.lhash_lock;
- tcp_listen_wlock();
+ inet_listen_wlock(&tcp_hashinfo);
} else {
sk->sk_hashent = tcp_v6_sk_hashfn(sk);
list = &tcp_hashinfo.ehash[sk->sk_hashent].chain;
