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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.c39
1 files changed, 24 insertions, 15 deletions
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 1f5d508bb18..d38ca7c77b9 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -427,31 +427,40 @@ void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo,
struct inet_timewait_sock *tw;
struct sock *sk;
struct hlist_nulls_node *node;
- int h;
+ unsigned int slot;
- local_bh_disable();
- for (h = 0; h <= hashinfo->ehash_mask; h++) {
- struct inet_ehash_bucket *head =
- inet_ehash_bucket(hashinfo, h);
- spinlock_t *lock = inet_ehash_lockp(hashinfo, h);
+ for (slot = 0; slot <= hashinfo->ehash_mask; slot++) {
+ struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
+restart_rcu:
+ rcu_read_lock();
restart:
- spin_lock(lock);
- sk_nulls_for_each(sk, node, &head->twchain) {
-
+ sk_nulls_for_each_rcu(sk, node, &head->twchain) {
tw = inet_twsk(sk);
if (!net_eq(twsk_net(tw), net) ||
tw->tw_family != family)
continue;
- atomic_inc(&tw->tw_refcnt);
- spin_unlock(lock);
+ if (unlikely(!atomic_inc_not_zero(&tw->tw_refcnt)))
+ continue;
+
+ if (unlikely(!net_eq(twsk_net(tw), net) ||
+ tw->tw_family != family)) {
+ inet_twsk_put(tw);
+ goto restart;
+ }
+
+ rcu_read_unlock();
inet_twsk_deschedule(tw, twdr);
inet_twsk_put(tw);
-
- goto restart;
+ goto restart_rcu;
}
- spin_unlock(lock);
+ /* If the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (get_nulls_value(node) != slot)
+ goto restart;
+ rcu_read_unlock();
}
- local_bh_enable();
}
EXPORT_SYMBOL_GPL(inet_twsk_purge);