diff options
Diffstat (limited to 'net/ipv4/inet_timewait_sock.c')
-rw-r--r-- | net/ipv4/inet_timewait_sock.c | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 9bcd8f7234ec..6d592f8555fb 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -87,19 +87,11 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw, refcnt += inet_twsk_bind_unhash(tw, hashinfo); spin_unlock(&bhead->lock); -#ifdef SOCK_REFCNT_DEBUG - if (atomic_read(&tw->tw_refcnt) != 1) { - pr_debug("%s timewait_sock %p refcnt=%d\n", - tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt)); - } -#endif - while (refcnt) { - inet_twsk_put(tw); - refcnt--; - } + BUG_ON(refcnt >= atomic_read(&tw->tw_refcnt)); + atomic_sub(refcnt, &tw->tw_refcnt); } -static noinline void inet_twsk_free(struct inet_timewait_sock *tw) +void inet_twsk_free(struct inet_timewait_sock *tw) { struct module *owner = tw->tw_prot->owner; twsk_destructor((struct sock *)tw); @@ -118,6 +110,18 @@ void inet_twsk_put(struct inet_timewait_sock *tw) } EXPORT_SYMBOL_GPL(inet_twsk_put); +static void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, + struct hlist_nulls_head *list) +{ + hlist_nulls_add_head_rcu(&tw->tw_node, list); +} + +static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, + struct hlist_head *list) +{ + hlist_add_head(&tw->tw_bind_node, list); +} + /* * Enter the time wait state. This is called with locally disabled BH. * Essentially we whip up a timewait bucket, copy the relevant info into it @@ -146,26 +150,21 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, spin_lock(lock); /* - * Step 2: Hash TW into TIMEWAIT chain. - * Should be done before removing sk from established chain - * because readers are lockless and search established first. + * Step 2: Hash TW into tcp ehash chain. + * Notes : + * - tw_refcnt is set to 3 because : + * - We have one reference from bhash chain. + * - We have one reference from ehash chain. + * We can use atomic_set() because prior spin_lock()/spin_unlock() + * committed into memory all tw fields. */ - inet_twsk_add_node_rcu(tw, &ehead->twchain); + atomic_set(&tw->tw_refcnt, 1 + 1 + 1); + inet_twsk_add_node_rcu(tw, &ehead->chain); - /* Step 3: Remove SK from established hash. */ + /* Step 3: Remove SK from hash chain */ if (__sk_nulls_del_node_init_rcu(sk)) sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - /* - * Notes : - * - We initially set tw_refcnt to 0 in inet_twsk_alloc() - * - We add one reference for the bhash link - * - We add one reference for the ehash link - * - We want this refcnt update done before allowing other - * threads to find this tw in ehash chain. - */ - atomic_add(1 + 1 + 1, &tw->tw_refcnt); - spin_unlock(lock); } EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); @@ -490,7 +489,9 @@ void inet_twsk_purge(struct inet_hashinfo *hashinfo, restart_rcu: rcu_read_lock(); restart: - sk_nulls_for_each_rcu(sk, node, &head->twchain) { + sk_nulls_for_each_rcu(sk, node, &head->chain) { + if (sk->sk_state != TCP_TIME_WAIT) + continue; tw = inet_twsk(sk); if ((tw->tw_family != family) || atomic_read(&twsk_net(tw)->count)) |