Merge commit 'v2.6.34-rc1' into perf/urgent

Conflicts:
	tools/perf/util/probe-event.c

Merge reason: Pick up -rc1 and resolve the conflict as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

6 files changed, 315 insertions, 170 deletions

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 3a66546cad0..e35d907fba2 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -47,6 +47,10 @@ static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
 #define dprintk(args...)
 #endif
 
+/* Maybe we'll add some more in the future. */
+#define LLC_CMSG_PKTINFO	1
+
+
 /**
  *	llc_ui_next_link_no - return the next unused link number for a sap
  *	@sap: Address of sap to get link number from.
@@ -136,6 +140,7 @@ static struct proto llc_proto = {
 	.name	  = "LLC",
 	.owner	  = THIS_MODULE,
 	.obj_size = sizeof(struct llc_sock),
+	.slab_flags = SLAB_DESTROY_BY_RCU,
 };
 
 /**
@@ -192,10 +197,8 @@ static int llc_ui_release(struct socket *sock)
 		llc->laddr.lsap, llc->daddr.lsap);
 	if (!llc_send_disc(sk))
 		llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
-	if (!sock_flag(sk, SOCK_ZAPPED)) {
-		llc_sap_put(llc->sap);
+	if (!sock_flag(sk, SOCK_ZAPPED))
 		llc_sap_remove_socket(llc->sap, sk);
-	}
 	release_sock(sk);
 	if (llc->dev)
 		dev_put(llc->dev);
@@ -255,7 +258,14 @@ static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 	if (!sock_flag(sk, SOCK_ZAPPED))
 		goto out;
 	rc = -ENODEV;
-	llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
+	if (sk->sk_bound_dev_if) {
+		llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
+		if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
+			dev_put(llc->dev);
+			llc->dev = NULL;
+		}
+	} else
+		llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
 	if (!llc->dev)
 		goto out;
 	rc = -EUSERS;
@@ -306,7 +316,25 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 		goto out;
 	rc = -ENODEV;
 	rtnl_lock();
-	llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd, addr->sllc_mac);
+	if (sk->sk_bound_dev_if) {
+		llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
+		if (llc->dev) {
+			if (!addr->sllc_arphrd)
+				addr->sllc_arphrd = llc->dev->type;
+			if (llc_mac_null(addr->sllc_mac))
+				memcpy(addr->sllc_mac, llc->dev->dev_addr,
+				       IFHWADDRLEN);
+			if (addr->sllc_arphrd != llc->dev->type ||
+			    !llc_mac_match(addr->sllc_mac,
+					   llc->dev->dev_addr)) {
+				rc = -EINVAL;
+				dev_put(llc->dev);
+				llc->dev = NULL;
+			}
+		}
+	} else
+		llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd,
+					   addr->sllc_mac);
 	rtnl_unlock();
 	if (!llc->dev)
 		goto out;
@@ -322,7 +350,6 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 		rc = -EBUSY; /* some other network layer is using the sap */
 		if (!sap)
 			goto out;
-		llc_sap_hold(sap);
 	} else {
 		struct llc_addr laddr, daddr;
 		struct sock *ask;
@@ -591,6 +618,20 @@ static int llc_wait_data(struct sock *sk, long timeo)
 	return rc;
 }
 
+static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct llc_sock *llc = llc_sk(skb->sk);
+
+	if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
+		struct llc_pktinfo info;
+
+		info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
+		llc_pdu_decode_dsap(skb, &info.lpi_sap);
+		llc_pdu_decode_da(skb, info.lpi_mac);
+		put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
+	}
+}
+
 /**
  *	llc_ui_accept - accept a new incoming connection.
  *	@sock: Socket which connections arrive on.
@@ -812,6 +853,8 @@ copy_uaddr:
 		memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 		msg->msg_namelen = sizeof(*uaddr);
 	}
+	if (llc_sk(sk)->cmsg_flags)
+		llc_cmsg_rcv(msg, skb);
 	goto out;
 }
 
@@ -1030,6 +1073,12 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 			goto out;
 		llc->rw = opt;
 		break;
+	case LLC_OPT_PKTINFO:
+		if (opt)
+			llc->cmsg_flags |= LLC_CMSG_PKTINFO;
+		else
+			llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
+		break;
 	default:
 		rc = -ENOPROTOOPT;
 		goto out;
@@ -1083,6 +1132,9 @@ static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
 		val = llc->k;				break;
 	case LLC_OPT_RX_WIN:
 		val = llc->rw;				break;
+	case LLC_OPT_PKTINFO:
+		val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
+		break;
 	default:
 		rc = -ENOPROTOOPT;
 		goto out;
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index c6bab39b018..a8dde9b010d 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -468,6 +468,19 @@ static int llc_exec_conn_trans_actions(struct sock *sk,
 	return rc;
 }
 
+static inline bool llc_estab_match(const struct llc_sap *sap,
+				   const struct llc_addr *daddr,
+				   const struct llc_addr *laddr,
+				   const struct sock *sk)
+{
+	struct llc_sock *llc = llc_sk(sk);
+
+	return llc->laddr.lsap == laddr->lsap &&
+		llc->daddr.lsap == daddr->lsap &&
+		llc_mac_match(llc->laddr.mac, laddr->mac) &&
+		llc_mac_match(llc->daddr.mac, daddr->mac);
+}
+
 /**
  *	__llc_lookup_established - Finds connection for the remote/local sap/mac
  *	@sap: SAP
@@ -484,23 +497,35 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
 					     struct llc_addr *laddr)
 {
 	struct sock *rc;
-	struct hlist_node *node;
-
-	read_lock(&sap->sk_list.lock);
-	sk_for_each(rc, node, &sap->sk_list.list) {
-		struct llc_sock *llc = llc_sk(rc);
-
-		if (llc->laddr.lsap == laddr->lsap &&
-		    llc->daddr.lsap == daddr->lsap &&
-		    llc_mac_match(llc->laddr.mac, laddr->mac) &&
-		    llc_mac_match(llc->daddr.mac, daddr->mac)) {
-			sock_hold(rc);
+	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
+
+	rcu_read_lock();
+again:
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
+		if (llc_estab_match(sap, daddr, laddr, rc)) {
+			/* Extra checks required by SLAB_DESTROY_BY_RCU */
+			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
+				goto again;
+			if (unlikely(llc_sk(rc)->sap != sap ||
+				     !llc_estab_match(sap, daddr, laddr, rc))) {
+				sock_put(rc);
+				continue;
+			}
 			goto found;
 		}
 	}
 	rc = NULL;
+	/*
+	 * 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 (unlikely(get_nulls_value(node) != slot))
+		goto again;
 found:
-	read_unlock(&sap->sk_list.lock);
+	rcu_read_unlock();
 	return rc;
 }
 
@@ -516,6 +541,53 @@ struct sock *llc_lookup_established(struct llc_sap *sap,
 	return sk;
 }
 
+static inline bool llc_listener_match(const struct llc_sap *sap,
+				      const struct llc_addr *laddr,
+				      const struct sock *sk)
+{
+	struct llc_sock *llc = llc_sk(sk);
+
+	return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
+		llc->laddr.lsap == laddr->lsap &&
+		llc_mac_match(llc->laddr.mac, laddr->mac);
+}
+
+static struct sock *__llc_lookup_listener(struct llc_sap *sap,
+					  struct llc_addr *laddr)
+{
+	struct sock *rc;
+	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
+
+	rcu_read_lock();
+again:
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
+		if (llc_listener_match(sap, laddr, rc)) {
+			/* Extra checks required by SLAB_DESTROY_BY_RCU */
+			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
+				goto again;
+			if (unlikely(llc_sk(rc)->sap != sap ||
+				     !llc_listener_match(sap, laddr, rc))) {
+				sock_put(rc);
+				continue;
+			}
+			goto found;
+		}
+	}
+	rc = NULL;
+	/*
+	 * 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 (unlikely(get_nulls_value(node) != slot))
+		goto again;
+found:
+	rcu_read_unlock();
+	return rc;
+}
+
 /**
  *	llc_lookup_listener - Finds listener for local MAC + SAP
  *	@sap: SAP
@@ -529,24 +601,12 @@ struct sock *llc_lookup_established(struct llc_sap *sap,
 static struct sock *llc_lookup_listener(struct llc_sap *sap,
 					struct llc_addr *laddr)
 {
-	struct sock *rc;
-	struct hlist_node *node;
+	static struct llc_addr null_addr;
+	struct sock *rc = __llc_lookup_listener(sap, laddr);
 
-	read_lock(&sap->sk_list.lock);
-	sk_for_each(rc, node, &sap->sk_list.list) {
-		struct llc_sock *llc = llc_sk(rc);
+	if (!rc)
+		rc = __llc_lookup_listener(sap, &null_addr);
 
-		if (rc->sk_type == SOCK_STREAM && rc->sk_state == TCP_LISTEN &&
-		    llc->laddr.lsap == laddr->lsap &&
-		    (llc_mac_match(llc->laddr.mac, laddr->mac) ||
-		     llc_mac_null(llc->laddr.mac))) {
-			sock_hold(rc);
-			goto found;
-		}
-	}
-	rc = NULL;
-found:
-	read_unlock(&sap->sk_list.lock);
 	return rc;
 }
 
@@ -647,15 +707,22 @@ static int llc_find_offset(int state, int ev_type)
  *	@sap: SAP
  *	@sk: socket
  *
- *	This function adds a socket to sk_list of a SAP.
+ *	This function adds a socket to the hash tables of a SAP.
  */
 void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
 {
+	struct llc_sock *llc = llc_sk(sk);
+	struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
+	struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr);
+
 	llc_sap_hold(sap);
-	write_lock_bh(&sap->sk_list.lock);
 	llc_sk(sk)->sap = sap;
-	sk_add_node(sk, &sap->sk_list.list);
-	write_unlock_bh(&sap->sk_list.lock);
+
+	spin_lock_bh(&sap->sk_lock);
+	sap->sk_count++;
+	sk_nulls_add_node_rcu(sk, laddr_hb);
+	hlist_add_head(&llc->dev_hash_node, dev_hb);
+	spin_unlock_bh(&sap->sk_lock);
 }
 
 /**
@@ -663,14 +730,18 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
  *	@sap: SAP
  *	@sk: socket
  *
- *	This function removes a connection from sk_list.list of a SAP if
+ *	This function removes a connection from the hash tables of a SAP if
  *	the connection was in this list.
  */
 void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
 {
-	write_lock_bh(&sap->sk_list.lock);
-	sk_del_node_init(sk);
-	write_unlock_bh(&sap->sk_list.lock);
+	struct llc_sock *llc = llc_sk(sk);
+
+	spin_lock_bh(&sap->sk_lock);
+	sk_nulls_del_node_init_rcu(sk);
+	hlist_del(&llc->dev_hash_node);
+	sap->sk_count--;
+	spin_unlock_bh(&sap->sk_lock);
 	llc_sap_put(sap);
 }
 
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
index ff4c0ab96a6..78167e81dfe 100644
--- a/net/llc/llc_core.c
+++ b/net/llc/llc_core.c
@@ -23,7 +23,7 @@
 #include <net/llc.h>
 
 LIST_HEAD(llc_sap_list);
-DEFINE_RWLOCK(llc_sap_list_lock);
+DEFINE_SPINLOCK(llc_sap_list_lock);
 
 /**
  *	llc_sap_alloc - allocates and initializes sap.
@@ -33,40 +33,19 @@ DEFINE_RWLOCK(llc_sap_list_lock);
 static struct llc_sap *llc_sap_alloc(void)
 {
 	struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
+	int i;
 
 	if (sap) {
 		/* sap->laddr.mac - leave as a null, it's filled by bind */
 		sap->state = LLC_SAP_STATE_ACTIVE;
-		rwlock_init(&sap->sk_list.lock);
+		spin_lock_init(&sap->sk_lock);
+		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
+			INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
 		atomic_set(&sap->refcnt, 1);
 	}
 	return sap;
 }
 
-/**
- *	llc_add_sap - add sap to station list
- *	@sap: Address of the sap
- *
- *	Adds a sap to the LLC's station sap list.
- */
-static void llc_add_sap(struct llc_sap *sap)
-{
-	list_add_tail(&sap->node, &llc_sap_list);
-}
-
-/**
- *	llc_del_sap - del sap from station list
- *	@sap: Address of the sap
- *
- *	Removes a sap to the LLC's station sap list.
- */
-static void llc_del_sap(struct llc_sap *sap)
-{
-	write_lock_bh(&llc_sap_list_lock);
-	list_del(&sap->node);
-	write_unlock_bh(&llc_sap_list_lock);
-}
-
 static struct llc_sap *__llc_sap_find(unsigned char sap_value)
 {
 	struct llc_sap* sap;
@@ -90,13 +69,13 @@ out:
  */
 struct llc_sap *llc_sap_find(unsigned char sap_value)
 {
-	struct llc_sap* sap;
+	struct llc_sap *sap;
 
-	read_lock_bh(&llc_sap_list_lock);
+	rcu_read_lock_bh();
 	sap = __llc_sap_find(sap_value);
 	if (sap)
 		llc_sap_hold(sap);
-	read_unlock_bh(&llc_sap_list_lock);
+	rcu_read_unlock_bh();
 	return sap;
 }
 
@@ -117,7 +96,7 @@ struct llc_sap *llc_sap_open(unsigned char lsap,
 {
 	struct llc_sap *sap = NULL;
 
-	write_lock_bh(&llc_sap_list_lock);
+	spin_lock_bh(&llc_sap_list_lock);
 	if (__llc_sap_find(lsap)) /* SAP already exists */
 		goto out;
 	sap = llc_sap_alloc();
@@ -125,9 +104,9 @@ struct llc_sap *llc_sap_open(unsigned char lsap,
 		goto out;
 	sap->laddr.lsap = lsap;
 	sap->rcv_func	= func;
-	llc_add_sap(sap);
+	list_add_tail_rcu(&sap->node, &llc_sap_list);
 out:
-	write_unlock_bh(&llc_sap_list_lock);
+	spin_unlock_bh(&llc_sap_list_lock);
 	return sap;
 }
 
@@ -142,8 +121,14 @@ out:
  */
 void llc_sap_close(struct llc_sap *sap)
 {
-	WARN_ON(!hlist_empty(&sap->sk_list.list));
-	llc_del_sap(sap);
+	WARN_ON(sap->sk_count);
+
+	spin_lock_bh(&llc_sap_list_lock);
+	list_del_rcu(&sap->node);
+	spin_unlock_bh(&llc_sap_list_lock);
+
+	synchronize_rcu();
+
 	kfree(sap);
 }
 
diff --git a/net/llc/llc_output.c b/net/llc/llc_output.c
index 754f4fedc85..b38a1079a98 100644
--- a/net/llc/llc_output.c
+++ b/net/llc/llc_output.c
@@ -33,48 +33,19 @@
 int llc_mac_hdr_init(struct sk_buff *skb,
 		     const unsigned char *sa, const unsigned char *da)
 {
-	int rc = 0;
+	int rc = -EINVAL;
 
 	switch (skb->dev->type) {
-#ifdef CONFIG_TR
-	case ARPHRD_IEEE802_TR: {
-		struct net_device *dev = skb->dev;
-		struct trh_hdr *trh;
-
-		skb_push(skb, sizeof(*trh));
-		skb_reset_mac_header(skb);
-		trh = tr_hdr(skb);
-		trh->ac = AC;
-		trh->fc = LLC_FRAME;
-		if (sa)
-			memcpy(trh->saddr, sa, dev->addr_len);
-		else
-			memset(trh->saddr, 0, dev->addr_len);
-		if (da) {
-			memcpy(trh->daddr, da, dev->addr_len);
-			tr_source_route(skb, trh, dev);
-			skb_reset_mac_header(skb);
-		}
-		break;
-	}
-#endif
+	case ARPHRD_IEEE802_TR:
 	case ARPHRD_ETHER:
-	case ARPHRD_LOOPBACK: {
-		unsigned short len = skb->len;
-		struct ethhdr *eth;
-
-		skb_push(skb, sizeof(*eth));
-		skb_reset_mac_header(skb);
-		eth = eth_hdr(skb);
-		eth->h_proto = htons(len);
-		memcpy(eth->h_dest, da, ETH_ALEN);
-		memcpy(eth->h_source, sa, ETH_ALEN);
+	case ARPHRD_LOOPBACK:
+		rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa,
+				     skb->len);
+		if (rc > 0)
+			rc = 0;
 		break;
-	}
 	default:
-		printk(KERN_WARNING "device type not supported: %d\n",
-		       skb->dev->type);
-		rc = -EINVAL;
+		WARN(1, "device type not supported: %d\n", skb->dev->type);
 	}
 	return rc;
 }
diff --git a/net/llc/llc_proc.c b/net/llc/llc_proc.c
index be47ac427f6..7af1ff2d1f1 100644
--- a/net/llc/llc_proc.c
+++ b/net/llc/llc_proc.c
@@ -32,21 +32,23 @@ static void llc_ui_format_mac(struct seq_file *seq, u8 *addr)
 
 static struct sock *llc_get_sk_idx(loff_t pos)
 {
-	struct list_head *sap_entry;
 	struct llc_sap *sap;
-	struct hlist_node *node;
 	struct sock *sk = NULL;
-
-	list_for_each(sap_entry, &llc_sap_list) {
-		sap = list_entry(sap_entry, struct llc_sap, node);
-
-		read_lock_bh(&sap->sk_list.lock);
-		sk_for_each(sk, node, &sap->sk_list.list) {
-			if (!pos)
-				goto found;
-			--pos;
+	int i;
+
+	list_for_each_entry_rcu(sap, &llc_sap_list, node) {
+		spin_lock_bh(&sap->sk_lock);
+		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) {
+			struct hlist_nulls_head *head = &sap->sk_laddr_hash[i];
+			struct hlist_nulls_node *node;
+
+			sk_nulls_for_each(sk, node, head) {
+				if (!pos)
+					goto found; /* keep the lock */
+				--pos;
+			}
 		}
-		read_unlock_bh(&sap->sk_list.lock);
+		spin_unlock_bh(&sap->sk_lock);
 	}
 	sk = NULL;
 found:
@@ -57,10 +59,23 @@ static void *llc_seq_start(struct seq_file *seq, loff_t *pos)
 {
 	loff_t l = *pos;
 
-	read_lock_bh(&llc_sap_list_lock);
+	rcu_read_lock_bh();
 	return l ? llc_get_sk_idx(--l) : SEQ_START_TOKEN;
 }
 
+static struct sock *laddr_hash_next(struct llc_sap *sap, int bucket)
+{
+	struct hlist_nulls_node *node;
+	struct sock *sk = NULL;
+
+	while (++bucket < LLC_SK_LADDR_HASH_ENTRIES)
+		sk_nulls_for_each(sk, node, &sap->sk_laddr_hash[bucket])
+			goto out;
+
+out:
+	return sk;
+}
+
 static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct sock* sk, *next;
@@ -73,25 +88,23 @@ static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 		goto out;
 	}
 	sk = v;
-	next = sk_next(sk);
+	next = sk_nulls_next(sk);
 	if (next) {
 		sk = next;
 		goto out;
 	}
 	llc = llc_sk(sk);
 	sap = llc->sap;
-	read_unlock_bh(&sap->sk_list.lock);
-	sk = NULL;
-	for (;;) {
-		if (sap->node.next == &llc_sap_list)
-			break;
-		sap = list_entry(sap->node.next, struct llc_sap, node);
-		read_lock_bh(&sap->sk_list.lock);
-		if (!hlist_empty(&sap->sk_list.list)) {
-			sk = sk_head(&sap->sk_list.list);
-			break;
-		}
-		read_unlock_bh(&sap->sk_list.lock);
+	sk = laddr_hash_next(sap, llc_sk_laddr_hashfn(sap, &llc->laddr));
+	if (sk)
+		goto out;
+	spin_unlock_bh(&sap->sk_lock);
+	list_for_each_entry_continue_rcu(sap, &llc_sap_list, node) {
+		spin_lock_bh(&sap->sk_lock);
+		sk = laddr_hash_next(sap, -1);
+		if (sk)
+			break; /* keep the lock */
+		spin_unlock_bh(&sap->sk_lock);
 	}
 out:
 	return sk;
@@ -104,9 +117,9 @@ static void llc_seq_stop(struct seq_file *seq, void *v)
 		struct llc_sock *llc = llc_sk(sk);
 		struct llc_sap *sap = llc->sap;
 
-		read_unlock_bh(&sap->sk_list.lock);
+		spin_unlock_bh(&sap->sk_lock);
 	}
-	read_unlock_bh(&llc_sap_list_lock);
+	rcu_read_unlock_bh();
 }
 
 static int llc_seq_socket_show(struct seq_file *seq, void *v)
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 008de1fc42c..ad6e6e1cf22 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -297,6 +297,17 @@ static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb,
 	llc_sap_state_process(sap, skb);
 }
 
+static inline bool llc_dgram_match(const struct llc_sap *sap,
+				   const struct llc_addr *laddr,
+				   const struct sock *sk)
+{
+     struct llc_sock *llc = llc_sk(sk);
+
+     return sk->sk_type == SOCK_DGRAM &&
+	  llc->laddr.lsap == laddr->lsap &&
+	  llc_mac_match(llc->laddr.mac, laddr->mac);
+}
+
 /**
  *	llc_lookup_dgram - Finds dgram socket for the local sap/mac
  *	@sap: SAP
@@ -309,25 +320,68 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
 				     const struct llc_addr *laddr)
 {
 	struct sock *rc;
-	struct hlist_node *node;
-
-	read_lock_bh(&sap->sk_list.lock);
-	sk_for_each(rc, node, &sap->sk_list.list) {
-		struct llc_sock *llc = llc_sk(rc);
-
-		if (rc->sk_type == SOCK_DGRAM &&
-		    llc->laddr.lsap == laddr->lsap &&
-		    llc_mac_match(llc->laddr.mac, laddr->mac)) {
-			sock_hold(rc);
+	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
+
+	rcu_read_lock_bh();
+again:
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
+		if (llc_dgram_match(sap, laddr, rc)) {
+			/* Extra checks required by SLAB_DESTROY_BY_RCU */
+			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
+				goto again;
+			if (unlikely(llc_sk(rc)->sap != sap ||
+				     !llc_dgram_match(sap, laddr, rc))) {
+				sock_put(rc);
+				continue;
+			}
 			goto found;
 		}
 	}
 	rc = NULL;
+	/*
+	 * 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 (unlikely(get_nulls_value(node) != slot))
+		goto again;
 found:
-	read_unlock_bh(&sap->sk_list.lock);
+	rcu_read_unlock_bh();
 	return rc;
 }
 
+static inline bool llc_mcast_match(const struct llc_sap *sap,
+				   const struct llc_addr *laddr,
+				   const struct sk_buff *skb,
+				   const struct sock *sk)
+{
+     struct llc_sock *llc = llc_sk(sk);
+
+     return sk->sk_type == SOCK_DGRAM &&
+	  llc->laddr.lsap == laddr->lsap &&
+	  llc->dev == skb->dev;
+}
+
+static void llc_do_mcast(struct llc_sap *sap, struct sk_buff *skb,
+			 struct sock **stack, int count)
+{
+	struct sk_buff *skb1;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		skb1 = skb_clone(skb, GFP_ATOMIC);
+		if (!skb1) {
+			sock_put(stack[i]);
+			continue;
+		}
+
+		llc_sap_rcv(sap, skb1, stack[i]);
+		sock_put(stack[i]);
+	}
+}
+
 /**
  * 	llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
  *	@sap: SAP
@@ -340,32 +394,31 @@ static void llc_sap_mcast(struct llc_sap *sap,
 			  const struct llc_addr *laddr,
 			  struct sk_buff *skb)
 {
-	struct sock *sk;
+	int i = 0, count = 256 / sizeof(struct sock *);
+	struct sock *sk, *stack[count];
 	struct hlist_node *node;
+	struct llc_sock *llc;
+	struct hlist_head *dev_hb = llc_sk_dev_hash(sap, skb->dev->ifindex);
 
-	read_lock_bh(&sap->sk_list.lock);
-	sk_for_each(sk, node, &sap->sk_list.list) {
-		struct llc_sock *llc = llc_sk(sk);
-		struct sk_buff *skb1;
+	spin_lock_bh(&sap->sk_lock);
+	hlist_for_each_entry(llc, node, dev_hb, dev_hash_node) {
 
-		if (sk->sk_type != SOCK_DGRAM)
-			continue;
+		sk = &llc->sk;
 
-		if (llc->laddr.lsap != laddr->lsap)
+		if (!llc_mcast_match(sap, laddr, skb, sk))
 			continue;
 
-		if (llc->dev != skb->dev)
-			continue;
-
-		skb1 = skb_clone(skb, GFP_ATOMIC);
-		if (!skb1)
-			break;
-
 		sock_hold(sk);
-		llc_sap_rcv(sap, skb1, sk);
-		sock_put(sk);
+		if (i < count)
+			stack[i++] = sk;
+		else {
+			llc_do_mcast(sap, skb, stack, i);
+			i = 0;
+		}
 	}
-	read_unlock_bh(&sap->sk_list.lock);
+	spin_unlock_bh(&sap->sk_lock);
+
+	llc_do_mcast(sap, skb, stack, i);
 }