GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-29 10:01:25 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

[INET]: Generalise the tcp_listen_ lock routines

Browse source 
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo 2005-08-09 20:08:09 -07:00 • committed by David S. Miller
parent 6e04e02165
commit f3f05f7046
6 changed files with 94 additions and 87 deletions
Download patch file Download diff file Expand all files Collapse all files

70
net/ipv4/tcp_ipv4.c
View file

@ -228,62 +228,11 @@ fail:
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 @@ void tcp_unhash(struct sock *sk)
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 @@ ok:
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 @@ ok:
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 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
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 @@ static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
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 @@ static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
}
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 @@ void __init tcp_v4_init(struct net_proto_family *ops)
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);