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path: root/net/ipv4/inet_timewait_sock.c
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Diffstat (limited to 'net/ipv4/inet_timewait_sock.c')
-rw-r--r--net/ipv4/inet_timewait_sock.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index b563e0c46bac..c3ea4906d237 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -97,7 +97,7 @@ static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
* Essentially we whip up a timewait bucket, copy the relevant info into it
* from the SK, and mess with hash chains and list linkage.
*/
-void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
+void inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
struct inet_hashinfo *hashinfo)
{
const struct inet_sock *inet = inet_sk(sk);
@@ -119,18 +119,6 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
spin_lock(lock);
- /*
- * Step 2: Hash TW into tcp ehash chain.
- * Notes :
- * - tw_refcnt is set to 4 because :
- * - We have one reference from bhash chain.
- * - We have one reference from ehash chain.
- * - We have one reference from timer.
- * - One reference for ourself (our caller will release it).
- * We can use atomic_set() because prior spin_lock()/spin_unlock()
- * committed into memory all tw fields.
- */
- refcount_set(&tw->tw_refcnt, 4);
inet_twsk_add_node_rcu(tw, &ehead->chain);
/* Step 3: Remove SK from hash chain */
@@ -138,8 +126,19 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
spin_unlock(lock);
+
+ /* tw_refcnt is set to 3 because we have :
+ * - one reference for bhash chain.
+ * - one reference for ehash chain.
+ * - one reference for timer.
+ * We can use atomic_set() because prior spin_lock()/spin_unlock()
+ * committed into memory all tw fields.
+ * Also note that after this point, we lost our implicit reference
+ * so we are not allowed to use tw anymore.
+ */
+ refcount_set(&tw->tw_refcnt, 3);
}
-EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
+EXPORT_SYMBOL_GPL(inet_twsk_hashdance);
static void tw_timer_handler(struct timer_list *t)
{
@@ -271,14 +270,14 @@ restart:
continue;
tw = inet_twsk(sk);
if ((tw->tw_family != family) ||
- atomic_read(&twsk_net(tw)->count))
+ refcount_read(&twsk_net(tw)->count))
continue;
if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt)))
continue;
if (unlikely((tw->tw_family != family) ||
- atomic_read(&twsk_net(tw)->count))) {
+ refcount_read(&twsk_net(tw)->count))) {
inet_twsk_put(tw);
goto restart;
}