1 files changed, 142 insertions, 135 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 44981906fb91..6a1045da48d2 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -35,7 +35,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
         struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 
         if (tb != NULL) {
-                tb->ib_net       = hold_net(net);
+                write_pnet(&tb->ib_net, hold_net(net));
                 tb->port      = snum;
                 tb->fastreuse = 0;
                 INIT_HLIST_HEAD(&tb->owners);
@@ -51,7 +51,7 @@ void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket
 {
         if (hlist_empty(&tb->owners)) {
                 __hlist_del(&tb->node);
-                release_net(tb->ib_net);
+                release_net(ib_net(tb));
                 kmem_cache_free(cachep, tb);
         }
 }
@@ -110,33 +110,29 @@ void __inet_inherit_port(struct sock *sk, struct sock *child)
 
 EXPORT_SYMBOL_GPL(__inet_inherit_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)
-        __acquires(hashinfo->lhash_lock)
+static inline int compute_score(struct sock *sk, struct net *net,
+                                const unsigned short hnum, const __be32 daddr,
+                                const int dif)
 {
-        write_lock(&hashinfo->lhash_lock);
-
-        if (atomic_read(&hashinfo->lhash_users)) {
-                DEFINE_WAIT(wait);
+        int score = -1;
+        struct inet_sock *inet = inet_sk(sk);
 
-                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);
+        if (net_eq(sock_net(sk), net) && inet->num == hnum &&
+                        !ipv6_only_sock(sk)) {
+                __be32 rcv_saddr = inet->rcv_saddr;
+                score = sk->sk_family == PF_INET ? 1 : 0;
+                if (rcv_saddr) {
+                        if (rcv_saddr != daddr)
+                                return -1;
+                        score += 2;
+                }
+                if (sk->sk_bound_dev_if) {
+                        if (sk->sk_bound_dev_if != dif)
+                                return -1;
+                        score += 2;
                 }
-
-                finish_wait(&hashinfo->lhash_wait, &wait);
         }
+        return score;
 }
 
 /*
@@ -145,72 +141,48 @@ void inet_listen_wlock(struct inet_hashinfo *hashinfo)
  * remote address for the connection. So always assume those are both
  * wildcarded during the search since they can never be otherwise.
  */
-static struct sock *inet_lookup_listener_slow(struct net *net,
-                                              const struct hlist_head *head,
-                                              const __be32 daddr,
-                                              const unsigned short hnum,
-                                              const int dif)
-{
-        struct sock *result = NULL, *sk;
-        const struct hlist_node *node;
-        int hiscore = -1;
-
-        sk_for_each(sk, node, head) {
-                const struct inet_sock *inet = inet_sk(sk);
-
-                if (net_eq(sock_net(sk), net) && inet->num == hnum &&
-                                !ipv6_only_sock(sk)) {
-                        const __be32 rcv_saddr = inet->rcv_saddr;
-                        int score = sk->sk_family == PF_INET ? 1 : 0;
-
-                        if (rcv_saddr) {
-                                if (rcv_saddr != daddr)
-                                        continue;
-                                score += 2;
-                        }
-                        if (sk->sk_bound_dev_if) {
-                                if (sk->sk_bound_dev_if != dif)
-                                        continue;
-                                score += 2;
-                        }
-                        if (score == 5)
-                                return sk;
-                        if (score > hiscore) {
-                                hiscore = score;
-                                result  = sk;
-                        }
-                }
-        }
-        return result;
-}
 
-/* Optimize the common listener case. */
+
 struct sock *__inet_lookup_listener(struct net *net,
                                     struct inet_hashinfo *hashinfo,
                                     const __be32 daddr, const unsigned short hnum,
                                     const int dif)
 {
-        struct sock *sk = NULL;
-        const struct hlist_head *head;
-
-        read_lock(&hashinfo->lhash_lock);
-        head = &hashinfo->listening_hash[inet_lhashfn(net, hnum)];
-        if (!hlist_empty(head)) {
-                const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
-
-                if (inet->num == hnum && !sk->sk_node.next &&
-                    (!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
-                    (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
-                    !sk->sk_bound_dev_if && net_eq(sock_net(sk), net))
-                        goto sherry_cache;
-                sk = inet_lookup_listener_slow(net, head, daddr, hnum, dif);
+        struct sock *sk, *result;
+        struct hlist_nulls_node *node;
+        unsigned int hash = inet_lhashfn(net, hnum);
+        struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
+        int score, hiscore;
+
+        rcu_read_lock();
+begin:
+        result = NULL;
+        hiscore = -1;
+        sk_nulls_for_each_rcu(sk, node, &ilb->head) {
+                score = compute_score(sk, net, hnum, daddr, dif);
+                if (score > hiscore) {
+                        result = sk;
+                        hiscore = score;
+                }
         }
-        if (sk) {
-sherry_cache:
-                sock_hold(sk);
+        /*
+         * 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) != hash + LISTENING_NULLS_BASE)
+                goto begin;
+        if (result) {
+                if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
+                        result = NULL;
+                else if (unlikely(compute_score(result, net, hnum, daddr,
+                                  dif) < hiscore)) {
+                        sock_put(result);
+                        goto begin;
+                }
         }
-        read_unlock(&hashinfo->lhash_lock);
-        return sk;
+        rcu_read_unlock();
+        return result;
 }
 EXPORT_SYMBOL_GPL(__inet_lookup_listener);
 
@@ -223,35 +195,65 @@ struct sock * __inet_lookup_established(struct net *net,
         INET_ADDR_COOKIE(acookie, saddr, daddr)
         const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
         struct sock *sk;
-        const struct hlist_node *node;
+        const struct hlist_nulls_node *node;
         /* Optimize here for direct hit, only listening connections can
          * have wildcards anyways.
          */
         unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
-        struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
-        rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
+        unsigned int slot = hash & (hashinfo->ehash_size - 1);
+        struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
 
-        prefetch(head->chain.first);
-        read_lock(lock);
-        sk_for_each(sk, node, &head->chain) {
+        rcu_read_lock();
+begin:
+        sk_nulls_for_each_rcu(sk, node, &head->chain) {
                 if (INET_MATCH(sk, net, hash, acookie,
-                                        saddr, daddr, ports, dif))
-                        goto hit; /* You sunk my battleship! */
+                                        saddr, daddr, ports, dif)) {
+                        if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
+                                goto begintw;
+                        if (unlikely(!INET_MATCH(sk, net, hash, acookie,
+                                saddr, daddr, ports, dif))) {
+                                sock_put(sk);
+                                goto begin;
+                        }
+                        goto out;
+                }
         }
+        /*
+         * 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 begin;
 
+begintw:
         /* Must check for a TIME_WAIT'er before going to listener hash. */
-        sk_for_each(sk, node, &head->twchain) {
+        sk_nulls_for_each_rcu(sk, node, &head->twchain) {
                 if (INET_TW_MATCH(sk, net, hash, acookie,
-                                        saddr, daddr, ports, dif))
-                        goto hit;
+                                        saddr, daddr, ports, dif)) {
+                        if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) {
+                                sk = NULL;
+                                goto out;
+                        }
+                        if (unlikely(!INET_TW_MATCH(sk, net, hash, acookie,
+                                 saddr, daddr, ports, dif))) {
+                                sock_put(sk);
+                                goto begintw;
+                        }
+                        goto out;
+                }
         }
+        /*
+         * 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 begintw;
         sk = NULL;
 out:
-        read_unlock(lock);
+        rcu_read_unlock();
         return sk;
-hit:
-        sock_hold(sk);
-        goto out;
 }
 EXPORT_SYMBOL_GPL(__inet_lookup_established);
 
@@ -270,16 +272,15 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row,
         struct net *net = sock_net(sk);
         unsigned int hash = inet_ehashfn(net, daddr, lport, saddr, inet->dport);
         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
-        rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
+        spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
         struct sock *sk2;
-        const struct hlist_node *node;
+        const struct hlist_nulls_node *node;
         struct inet_timewait_sock *tw;
 
-        prefetch(head->chain.first);
-        write_lock(lock);
+        spin_lock(lock);
 
         /* Check TIME-WAIT sockets first. */
-        sk_for_each(sk2, node, &head->twchain) {
+        sk_nulls_for_each(sk2, node, &head->twchain) {
                 tw = inet_twsk(sk2);
 
                 if (INET_TW_MATCH(sk2, net, hash, acookie,
@@ -293,7 +294,7 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row,
         tw = NULL;
 
         /* And established part... */
-        sk_for_each(sk2, node, &head->chain) {
+        sk_nulls_for_each(sk2, node, &head->chain) {
                 if (INET_MATCH(sk2, net, hash, acookie,
                                         saddr, daddr, ports, dif))
                         goto not_unique;
@@ -306,9 +307,9 @@ unique:
         inet->sport = htons(lport);
         sk->sk_hash = hash;
         WARN_ON(!sk_unhashed(sk));
-        __sk_add_node(sk, &head->chain);
+        __sk_nulls_add_node_rcu(sk, &head->chain);
+        spin_unlock(lock);
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
-        write_unlock(lock);
 
         if (twp) {
                 *twp = tw;
@@ -324,7 +325,7 @@ unique:
         return 0;
 
 not_unique:
-        write_unlock(lock);
+        spin_unlock(lock);
         return -EADDRNOTAVAIL;
 }
 
@@ -338,8 +339,8 @@ static inline u32 inet_sk_port_offset(const struct sock *sk)
 void __inet_hash_nolisten(struct sock *sk)
 {
         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
-        struct hlist_head *list;
-        rwlock_t *lock;
+        struct hlist_nulls_head *list;
+        spinlock_t *lock;
         struct inet_ehash_bucket *head;
 
         WARN_ON(!sk_unhashed(sk));
@@ -349,18 +350,17 @@ void __inet_hash_nolisten(struct sock *sk)
         list = &head->chain;
         lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 
-        write_lock(lock);
-        __sk_add_node(sk, list);
+        spin_lock(lock);
+        __sk_nulls_add_node_rcu(sk, list);
+        spin_unlock(lock);
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
-        write_unlock(lock);
 }
 EXPORT_SYMBOL_GPL(__inet_hash_nolisten);
 
 static void __inet_hash(struct sock *sk)
 {
         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
-        struct hlist_head *list;
-        rwlock_t *lock;
+        struct inet_listen_hashbucket *ilb;
 
         if (sk->sk_state != TCP_LISTEN) {
                 __inet_hash_nolisten(sk);
@@ -368,14 +368,12 @@ static void __inet_hash(struct sock *sk)
         }
 
         WARN_ON(!sk_unhashed(sk));
-        list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
-        lock = &hashinfo->lhash_lock;
+        ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
 
-        inet_listen_wlock(hashinfo);
-        __sk_add_node(sk, list);
+        spin_lock(&ilb->lock);
+        __sk_nulls_add_node_rcu(sk, &ilb->head);
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
-        write_unlock(lock);
-        wake_up(&hashinfo->lhash_wait);
+        spin_unlock(&ilb->lock);
 }
 
 void inet_hash(struct sock *sk)
@@ -390,27 +388,23 @@ EXPORT_SYMBOL_GPL(inet_hash);
 
 void inet_unhash(struct sock *sk)
 {
-        rwlock_t *lock;
         struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+        spinlock_t *lock;
+        int done;
 
         if (sk_unhashed(sk))
-                goto out;
+                return;
 
-        if (sk->sk_state == TCP_LISTEN) {
-                local_bh_disable();
-                inet_listen_wlock(hashinfo);
-                lock = &hashinfo->lhash_lock;
-        } else {
+        if (sk->sk_state == TCP_LISTEN)
+                lock = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)].lock;
+        else
                 lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
-                write_lock_bh(lock);
-        }
 
-        if (__sk_del_node_init(sk))
+        spin_lock_bh(lock);
+        done =__sk_nulls_del_node_init_rcu(sk);
+        if (done)
                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
-        write_unlock_bh(lock);
-out:
-        if (sk->sk_state == TCP_LISTEN)
-                wake_up(&hashinfo->lhash_wait);
+        spin_unlock_bh(lock);
 }
 EXPORT_SYMBOL_GPL(inet_unhash);
 
@@ -449,7 +443,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
                          * unique enough.
                          */
                         inet_bind_bucket_for_each(tb, node, &head->chain) {
-                                if (tb->ib_net == net && tb->port == port) {
+                                if (ib_net(tb) == net && tb->port == port) {
                                         WARN_ON(hlist_empty(&tb->owners));
                                         if (tb->fastreuse >= 0)
                                                 goto next_port;
@@ -524,3 +518,16 @@ int inet_hash_connect(struct inet_timewait_death_row *death_row,
 }
 
 EXPORT_SYMBOL_GPL(inet_hash_connect);
+
+void inet_hashinfo_init(struct inet_hashinfo *h)
+{
+        int i;
+
+        for (i = 0; i < INET_LHTABLE_SIZE; i++) {
+                spin_lock_init(&h->listening_hash[i].lock);
+                INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].head,
+                                      i + LISTENING_NULLS_BASE);
+                }
+}
+
+EXPORT_SYMBOL_GPL(inet_hashinfo_init);