1 files changed, 160 insertions, 365 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ab450c099aa..9d2118e5fbc 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -279,15 +279,22 @@
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
+#include <net/busy_poll.h>
 
 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
 
+int sysctl_tcp_min_tso_segs __read_mostly = 2;
+
+int sysctl_tcp_autocorking __read_mostly = 1;
+
 struct percpu_counter tcp_orphan_count;
 EXPORT_SYMBOL_GPL(tcp_orphan_count);
 
+long sysctl_tcp_mem[3] __read_mostly;
 int sysctl_tcp_wmem[3] __read_mostly;
 int sysctl_tcp_rmem[3] __read_mostly;
 
+EXPORT_SYMBOL(sysctl_tcp_mem);
 EXPORT_SYMBOL(sysctl_tcp_rmem);
 EXPORT_SYMBOL(sysctl_tcp_wmem);
 
@@ -374,13 +381,13 @@ void tcp_init_sock(struct sock *sk)
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	skb_queue_head_init(&tp->out_of_order_queue);
+	__skb_queue_head_init(&tp->out_of_order_queue);
 	tcp_init_xmit_timers(sk);
 	tcp_prequeue_init(tp);
 	INIT_LIST_HEAD(&tp->tsq_node);
 
 	icsk->icsk_rto = TCP_TIMEOUT_INIT;
-	tp->mdev = TCP_TIMEOUT_INIT;
+	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
 
 	/* So many TCP implementations out there (incorrectly) count the
 	 * initial SYN frame in their delayed-ACK and congestion control
@@ -409,10 +416,6 @@ void tcp_init_sock(struct sock *sk)
 
 	icsk->icsk_sync_mss = tcp_sync_mss;
 
-	/* Presumed zeroed, in order of appearance:
-	 *	cookie_in_always, cookie_out_never,
-	 *	s_data_constant, s_data_in, s_data_out
-	 */
 	sk->sk_sndbuf = sysctl_tcp_wmem[1];
 	sk->sk_rcvbuf = sysctl_tcp_rmem[1];
 
@@ -436,6 +439,8 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 	struct sock *sk = sock->sk;
 	const struct tcp_sock *tp = tcp_sk(sk);
 
+	sock_rps_record_flow(sk);
+
 	sock_poll_wait(file, sk_sleep(sk), wait);
 	if (sk->sk_state == TCP_LISTEN)
 		return inet_csk_listen_poll(sk);
@@ -496,7 +501,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 			mask |= POLLIN | POLLRDNORM;
 
 		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
-			if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
+			if (sk_stream_is_writeable(sk)) {
 				mask |= POLLOUT | POLLWRNORM;
 			} else {  /* send SIGIO later */
 				set_bit(SOCK_ASYNC_NOSPACE,
@@ -507,7 +512,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
 				 * wspace test but before the flags are set,
 				 * IO signal will be lost.
 				 */
-				if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
+				if (sk_stream_is_writeable(sk))
 					mask |= POLLOUT | POLLWRNORM;
 			}
 		} else
@@ -616,19 +621,58 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
 		tp->snd_up = tp->write_seq;
 }
 
-static inline void tcp_push(struct sock *sk, int flags, int mss_now,
-			    int nonagle)
+/* If a not yet filled skb is pushed, do not send it if
+ * we have data packets in Qdisc or NIC queues :
+ * Because TX completion will happen shortly, it gives a chance
+ * to coalesce future sendmsg() payload into this skb, without
+ * need for a timer, and with no latency trade off.
+ * As packets containing data payload have a bigger truesize
+ * than pure acks (dataless) packets, the last checks prevent
+ * autocorking if we only have an ACK in Qdisc/NIC queues,
+ * or if TX completion was delayed after we processed ACK packet.
+ */
+static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
+				int size_goal)
 {
-	if (tcp_send_head(sk)) {
-		struct tcp_sock *tp = tcp_sk(sk);
+	return skb->len < size_goal &&
+	       sysctl_tcp_autocorking &&
+	       skb != tcp_write_queue_head(sk) &&
+	       atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
+}
+
+static void tcp_push(struct sock *sk, int flags, int mss_now,
+		     int nonagle, int size_goal)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	if (!tcp_send_head(sk))
+		return;
 
-		if (!(flags & MSG_MORE) || forced_push(tp))
-			tcp_mark_push(tp, tcp_write_queue_tail(sk));
+	skb = tcp_write_queue_tail(sk);
+	if (!(flags & MSG_MORE) || forced_push(tp))
+		tcp_mark_push(tp, skb);
 
-		tcp_mark_urg(tp, flags);
-		__tcp_push_pending_frames(sk, mss_now,
-					  (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
+	tcp_mark_urg(tp, flags);
+
+	if (tcp_should_autocork(sk, skb, size_goal)) {
+
+		/* avoid atomic op if TSQ_THROTTLED bit is already set */
+		if (!test_bit(TSQ_THROTTLED, &tp->tsq_flags)) {
+			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
+			set_bit(TSQ_THROTTLED, &tp->tsq_flags);
+		}
+		/* It is possible TX completion already happened
+		 * before we set TSQ_THROTTLED.
+		 */
+		if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
+			return;
 	}
+
+	if (flags & MSG_MORE)
+		nonagle = TCP_NAGLE_CORK;
+
+	__tcp_push_pending_frames(sk, mss_now, nonagle);
 }
 
 static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
@@ -786,14 +830,24 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
 	xmit_size_goal = mss_now;
 
 	if (large_allowed && sk_can_gso(sk)) {
-		xmit_size_goal = ((sk->sk_gso_max_size - 1) -
-				  inet_csk(sk)->icsk_af_ops->net_header_len -
-				  inet_csk(sk)->icsk_ext_hdr_len -
-				  tp->tcp_header_len);
+		u32 gso_size, hlen;
+
+		/* Maybe we should/could use sk->sk_prot->max_header here ? */
+		hlen = inet_csk(sk)->icsk_af_ops->net_header_len +
+		       inet_csk(sk)->icsk_ext_hdr_len +
+		       tp->tcp_header_len;
+
+		/* Goal is to send at least one packet per ms,
+		 * not one big TSO packet every 100 ms.
+		 * This preserves ACK clocking and is consistent
+		 * with tcp_tso_should_defer() heuristic.
+		 */
+		gso_size = sk->sk_pacing_rate / (2 * MSEC_PER_SEC);
+		gso_size = max_t(u32, gso_size,
+				 sysctl_tcp_min_tso_segs * mss_now);
 
-		/* TSQ : try to have two TSO segments in flight */
-		xmit_size_goal = min_t(u32, xmit_size_goal,
-				       sysctl_tcp_limit_output_bytes >> 1);
+		xmit_size_goal = min_t(u32, gso_size,
+				       sk->sk_gso_max_size - 1 - hlen);
 
 		xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
 
@@ -921,7 +975,8 @@ new_segment:
 wait_for_sndbuf:
 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 wait_for_memory:
-		tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+		tcp_push(sk, flags & ~MSG_MORE, mss_now,
+			 TCP_NAGLE_PUSH, size_goal);
 
 		if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
 			goto do_error;
@@ -931,7 +986,7 @@ wait_for_memory:
 
 out:
 	if (copied && !(flags & MSG_SENDPAGE_NOTLAST))
-		tcp_push(sk, flags, mss_now, tp->nonagle);
+		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
 	return copied;
 
 do_error:
@@ -989,7 +1044,8 @@ void tcp_free_fastopen_req(struct tcp_sock *tp)
 	}
 }
 
-static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *size)
+static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
+				int *copied, size_t size)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	int err, flags;
@@ -1004,11 +1060,12 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *size)
 	if (unlikely(tp->fastopen_req == NULL))
 		return -ENOBUFS;
 	tp->fastopen_req->data = msg;
+	tp->fastopen_req->size = size;
 
 	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
 	err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
 				    msg->msg_namelen, flags);
-	*size = tp->fastopen_req->copied;
+	*copied = tp->fastopen_req->copied;
 	tcp_free_fastopen_req(tp);
 	return err;
 }
@@ -1028,7 +1085,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
 	flags = msg->msg_flags;
 	if (flags & MSG_FASTOPEN) {
-		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn);
+		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
 		if (err == -EINPROGRESS && copied_syn > 0)
 			goto out;
 		else if (err)
@@ -1051,7 +1108,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	if (unlikely(tp->repair)) {
 		if (tp->repair_queue == TCP_RECV_QUEUE) {
 			copied = tcp_send_rcvq(sk, msg, size);
-			goto out;
+			goto out_nopush;
 		}
 
 		err = -EINVAL;
@@ -1118,6 +1175,13 @@ new_segment:
 					goto wait_for_memory;
 
 				/*
+				 * All packets are restored as if they have
+				 * already been sent.
+				 */
+				if (tp->repair)
+					TCP_SKB_CB(skb)->when = tcp_time_stamp;
+
+				/*
 				 * Check whether we can use HW checksum.
 				 */
 				if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
@@ -1205,7 +1269,8 @@ wait_for_sndbuf:
 			set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 wait_for_memory:
 			if (copied)
-				tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+				tcp_push(sk, flags & ~MSG_MORE, mss_now,
+					 TCP_NAGLE_PUSH, size_goal);
 
 			if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
 				goto do_error;
@@ -1216,7 +1281,8 @@ wait_for_memory:
 
 out:
 	if (copied)
-		tcp_push(sk, flags, mss_now, tp->nonagle);
+		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
+out_nopush:
 	release_sock(sk);
 	return copied + copied_syn;
 
@@ -1405,7 +1471,7 @@ static void tcp_service_net_dma(struct sock *sk, bool wait)
 	do {
 		if (dma_async_is_tx_complete(tp->ucopy.dma_chan,
 					      last_issued, &done,
-					      &used) == DMA_SUCCESS) {
+					      &used) == DMA_COMPLETE) {
 			/* Safe to free early-copied skbs now */
 			__skb_queue_purge(&sk->sk_async_wait_queue);
 			break;
@@ -1413,7 +1479,7 @@ static void tcp_service_net_dma(struct sock *sk, bool wait)
 			struct sk_buff *skb;
 			while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
 			       (dma_async_is_complete(skb->dma_cookie, done,
-						      used) == DMA_SUCCESS)) {
+						      used) == DMA_COMPLETE)) {
 				__skb_dequeue(&sk->sk_async_wait_queue);
 				kfree_skb(skb);
 			}
@@ -1551,6 +1617,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	struct sk_buff *skb;
 	u32 urg_hole = 0;
 
+	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
+	    (sk->sk_state == TCP_ESTABLISHED))
+		sk_busy_loop(sk, nonblock);
+
 	lock_sock(sk);
 
 	err = -ENOTCONN;
@@ -1599,11 +1669,11 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		    (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
 		    !sysctl_tcp_low_latency &&
 		    net_dma_find_channel()) {
-			preempt_enable_no_resched();
+			preempt_enable();
 			tp->ucopy.pinned_list =
 					dma_pin_iovec_pages(msg->msg_iov, len);
 		} else {
-			preempt_enable_no_resched();
+			preempt_enable();
 		}
 	}
 #endif
@@ -2162,7 +2232,7 @@ adjudge_to_death:
 	/*	This is a (useful) BSD violating of the RFC. There is a
 	 *	problem with TCP as specified in that the other end could
 	 *	keep a socket open forever with no application left this end.
-	 *	We use a 3 minute timeout (about the same as BSD) then kill
+	 *	We use a 1 minute timeout (about the same as BSD) then kill
 	 *	our end. If they send after that then tough - BUT: long enough
 	 *	that we won't make the old 4*rto = almost no time - whoops
 	 *	reset mistake.
@@ -2272,7 +2342,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 
 	sk->sk_shutdown = 0;
 	sock_reset_flag(sk, SOCK_DONE);
-	tp->srtt = 0;
+	tp->srtt_us = 0;
 	if ((tp->write_seq += tp->max_window + 2) == 0)
 		tp->write_seq = 1;
 	icsk->icsk_backoff = 0;
@@ -2440,10 +2510,11 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 	case TCP_THIN_DUPACK:
 		if (val < 0 || val > 1)
 			err = -EINVAL;
-		else
+		else {
 			tp->thin_dupack = val;
 			if (tp->thin_dupack)
 				tcp_disable_early_retrans(tp);
+		}
 		break;
 
 	case TCP_REPAIR:
@@ -2624,6 +2695,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
 		else
 			tp->tsoffset = val - tcp_time_stamp;
 		break;
+	case TCP_NOTSENT_LOWAT:
+		tp->notsent_lowat = val;
+		sk->sk_write_space(sk);
+		break;
 	default:
 		err = -ENOPROTOOPT;
 		break;
@@ -2711,8 +2786,8 @@ void tcp_get_info(const struct sock *sk, struct tcp_info *info)
 
 	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
 	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
-	info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
-	info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
+	info->tcpi_rtt = tp->srtt_us >> 3;
+	info->tcpi_rttvar = tp->mdev_us >> 2;
 	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
 	info->tcpi_snd_cwnd = tp->snd_cwnd;
 	info->tcpi_advmss = tp->advmss;
@@ -2722,6 +2797,11 @@ void tcp_get_info(const struct sock *sk, struct tcp_info *info)
 	info->tcpi_rcv_space = tp->rcvq_space.space;
 
 	info->tcpi_total_retrans = tp->total_retrans;
+
+	info->tcpi_pacing_rate = sk->sk_pacing_rate != ~0U ?
+					sk->sk_pacing_rate : ~0ULL;
+	info->tcpi_max_pacing_rate = sk->sk_max_pacing_rate != ~0U ?
+					sk->sk_max_pacing_rate : ~0ULL;
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);
 
@@ -2837,9 +2917,20 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 	case TCP_USER_TIMEOUT:
 		val = jiffies_to_msecs(icsk->icsk_user_timeout);
 		break;
+
+	case TCP_FASTOPEN:
+		if (icsk->icsk_accept_queue.fastopenq != NULL)
+			val = icsk->icsk_accept_queue.fastopenq->max_qlen;
+		else
+			val = 0;
+		break;
+
 	case TCP_TIMESTAMP:
 		val = tcp_time_stamp + tp->tsoffset;
 		break;
+	case TCP_NOTSENT_LOWAT:
+		val = tp->notsent_lowat;
+		break;
 	default:
 		return -ENOPROTOOPT;
 	}
@@ -2875,249 +2966,9 @@ int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
 EXPORT_SYMBOL(compat_tcp_getsockopt);
 #endif
 
-struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
-	netdev_features_t features)
-{
-	struct sk_buff *segs = ERR_PTR(-EINVAL);
-	struct tcphdr *th;
-	unsigned int thlen;
-	unsigned int seq;
-	__be32 delta;
-	unsigned int oldlen;
-	unsigned int mss;
-	struct sk_buff *gso_skb = skb;
-	__sum16 newcheck;
-	bool ooo_okay, copy_destructor;
-
-	if (!pskb_may_pull(skb, sizeof(*th)))
-		goto out;
-
-	th = tcp_hdr(skb);
-	thlen = th->doff * 4;
-	if (thlen < sizeof(*th))
-		goto out;
-
-	if (!pskb_may_pull(skb, thlen))
-		goto out;
-
-	oldlen = (u16)~skb->len;
-	__skb_pull(skb, thlen);
-
-	mss = skb_shinfo(skb)->gso_size;
-	if (unlikely(skb->len <= mss))
-		goto out;
-
-	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
-		/* Packet is from an untrusted source, reset gso_segs. */
-		int type = skb_shinfo(skb)->gso_type;
-
-		if (unlikely(type &
-			     ~(SKB_GSO_TCPV4 |
-			       SKB_GSO_DODGY |
-			       SKB_GSO_TCP_ECN |
-			       SKB_GSO_TCPV6 |
-			       SKB_GSO_GRE |
-			       SKB_GSO_UDP_TUNNEL |
-			       0) ||
-			     !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
-			goto out;
-
-		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
-
-		segs = NULL;
-		goto out;
-	}
-
-	copy_destructor = gso_skb->destructor == tcp_wfree;
-	ooo_okay = gso_skb->ooo_okay;
-	/* All segments but the first should have ooo_okay cleared */
-	skb->ooo_okay = 0;
-
-	segs = skb_segment(skb, features);
-	if (IS_ERR(segs))
-		goto out;
-
-	/* Only first segment might have ooo_okay set */
-	segs->ooo_okay = ooo_okay;
-
-	delta = htonl(oldlen + (thlen + mss));
-
-	skb = segs;
-	th = tcp_hdr(skb);
-	seq = ntohl(th->seq);
-
-	newcheck = ~csum_fold((__force __wsum)((__force u32)th->check +
-					       (__force u32)delta));
-
-	do {
-		th->fin = th->psh = 0;
-		th->check = newcheck;
-
-		if (skb->ip_summed != CHECKSUM_PARTIAL)
-			th->check =
-			     csum_fold(csum_partial(skb_transport_header(skb),
-						    thlen, skb->csum));
-
-		seq += mss;
-		if (copy_destructor) {
-			skb->destructor = gso_skb->destructor;
-			skb->sk = gso_skb->sk;
-			/* {tcp|sock}_wfree() use exact truesize accounting :
-			 * sum(skb->truesize) MUST be exactly be gso_skb->truesize
-			 * So we account mss bytes of 'true size' for each segment.
-			 * The last segment will contain the remaining.
-			 */
-			skb->truesize = mss;
-			gso_skb->truesize -= mss;
-		}
-		skb = skb->next;
-		th = tcp_hdr(skb);
-
-		th->seq = htonl(seq);
-		th->cwr = 0;
-	} while (skb->next);
-
-	/* Following permits TCP Small Queues to work well with GSO :
-	 * The callback to TCP stack will be called at the time last frag
-	 * is freed at TX completion, and not right now when gso_skb
-	 * is freed by GSO engine
-	 */
-	if (copy_destructor) {
-		swap(gso_skb->sk, skb->sk);
-		swap(gso_skb->destructor, skb->destructor);
-		swap(gso_skb->truesize, skb->truesize);
-	}
-
-	delta = htonl(oldlen + (skb->tail - skb->transport_header) +
-		      skb->data_len);
-	th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
-				(__force u32)delta));
-	if (skb->ip_summed != CHECKSUM_PARTIAL)
-		th->check = csum_fold(csum_partial(skb_transport_header(skb),
-						   thlen, skb->csum));
-
-out:
-	return segs;
-}
-EXPORT_SYMBOL(tcp_tso_segment);
-
-struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
-{
-	struct sk_buff **pp = NULL;
-	struct sk_buff *p;
-	struct tcphdr *th;
-	struct tcphdr *th2;
-	unsigned int len;
-	unsigned int thlen;
-	__be32 flags;
-	unsigned int mss = 1;
-	unsigned int hlen;
-	unsigned int off;
-	int flush = 1;
-	int i;
-
-	off = skb_gro_offset(skb);
-	hlen = off + sizeof(*th);
-	th = skb_gro_header_fast(skb, off);
-	if (skb_gro_header_hard(skb, hlen)) {
-		th = skb_gro_header_slow(skb, hlen, off);
-		if (unlikely(!th))
-			goto out;
-	}
-
-	thlen = th->doff * 4;
-	if (thlen < sizeof(*th))
-		goto out;
-
-	hlen = off + thlen;
-	if (skb_gro_header_hard(skb, hlen)) {
-		th = skb_gro_header_slow(skb, hlen, off);
-		if (unlikely(!th))
-			goto out;
-	}
-
-	skb_gro_pull(skb, thlen);
-
-	len = skb_gro_len(skb);
-	flags = tcp_flag_word(th);
-
-	for (; (p = *head); head = &p->next) {
-		if (!NAPI_GRO_CB(p)->same_flow)
-			continue;
-
-		th2 = tcp_hdr(p);
-
-		if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
-			NAPI_GRO_CB(p)->same_flow = 0;
-			continue;
-		}
-
-		goto found;
-	}
-
-	goto out_check_final;
-
-found:
-	flush = NAPI_GRO_CB(p)->flush;
-	flush |= (__force int)(flags & TCP_FLAG_CWR);
-	flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
-		  ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
-	flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
-	for (i = sizeof(*th); i < thlen; i += 4)
-		flush |= *(u32 *)((u8 *)th + i) ^
-			 *(u32 *)((u8 *)th2 + i);
-
-	mss = skb_shinfo(p)->gso_size;
-
-	flush |= (len - 1) >= mss;
-	flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
-
-	if (flush || skb_gro_receive(head, skb)) {
-		mss = 1;
-		goto out_check_final;
-	}
-
-	p = *head;
-	th2 = tcp_hdr(p);
-	tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
-
-out_check_final:
-	flush = len < mss;
-	flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH |
-					TCP_FLAG_RST | TCP_FLAG_SYN |
-					TCP_FLAG_FIN));
-
-	if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
-		pp = head;
-
-out:
-	NAPI_GRO_CB(skb)->flush |= flush;
-
-	return pp;
-}
-EXPORT_SYMBOL(tcp_gro_receive);
-
-int tcp_gro_complete(struct sk_buff *skb)
-{
-	struct tcphdr *th = tcp_hdr(skb);
-
-	skb->csum_start = skb_transport_header(skb) - skb->head;
-	skb->csum_offset = offsetof(struct tcphdr, check);
-	skb->ip_summed = CHECKSUM_PARTIAL;
-
-	skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
-
-	if (th->cwr)
-		skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
-
-	return 0;
-}
-EXPORT_SYMBOL(tcp_gro_complete);
-
 #ifdef CONFIG_TCP_MD5SIG
-static unsigned long tcp_md5sig_users;
-static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool;
-static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
+static struct tcp_md5sig_pool __percpu *tcp_md5sig_pool __read_mostly;
+static DEFINE_MUTEX(tcp_md5sig_mutex);
 
 static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool)
 {
@@ -3132,30 +2983,14 @@ static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool __percpu *pool)
 	free_percpu(pool);
 }
 
-void tcp_free_md5sig_pool(void)
-{
-	struct tcp_md5sig_pool __percpu *pool = NULL;
-
-	spin_lock_bh(&tcp_md5sig_pool_lock);
-	if (--tcp_md5sig_users == 0) {
-		pool = tcp_md5sig_pool;
-		tcp_md5sig_pool = NULL;
-	}
-	spin_unlock_bh(&tcp_md5sig_pool_lock);
-	if (pool)
-		__tcp_free_md5sig_pool(pool);
-}
-EXPORT_SYMBOL(tcp_free_md5sig_pool);
-
-static struct tcp_md5sig_pool __percpu *
-__tcp_alloc_md5sig_pool(struct sock *sk)
+static void __tcp_alloc_md5sig_pool(void)
 {
 	int cpu;
 	struct tcp_md5sig_pool __percpu *pool;
 
 	pool = alloc_percpu(struct tcp_md5sig_pool);
 	if (!pool)
-		return NULL;
+		return;
 
 	for_each_possible_cpu(cpu) {
 		struct crypto_hash *hash;
@@ -3166,53 +3001,27 @@ __tcp_alloc_md5sig_pool(struct sock *sk)
 
 		per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash;
 	}
-	return pool;
+	/* before setting tcp_md5sig_pool, we must commit all writes
+	 * to memory. See ACCESS_ONCE() in tcp_get_md5sig_pool()
+	 */
+	smp_wmb();
+	tcp_md5sig_pool = pool;
+	return;
 out_free:
 	__tcp_free_md5sig_pool(pool);
-	return NULL;
 }
 
-struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *sk)
+bool tcp_alloc_md5sig_pool(void)
 {
-	struct tcp_md5sig_pool __percpu *pool;
-	bool alloc = false;
-
-retry:
-	spin_lock_bh(&tcp_md5sig_pool_lock);
-	pool = tcp_md5sig_pool;
-	if (tcp_md5sig_users++ == 0) {
-		alloc = true;
-		spin_unlock_bh(&tcp_md5sig_pool_lock);
-	} else if (!pool) {
-		tcp_md5sig_users--;
-		spin_unlock_bh(&tcp_md5sig_pool_lock);
-		cpu_relax();
-		goto retry;
-	} else
-		spin_unlock_bh(&tcp_md5sig_pool_lock);
-
-	if (alloc) {
-		/* we cannot hold spinlock here because this may sleep. */
-		struct tcp_md5sig_pool __percpu *p;
-
-		p = __tcp_alloc_md5sig_pool(sk);
-		spin_lock_bh(&tcp_md5sig_pool_lock);
-		if (!p) {
-			tcp_md5sig_users--;
-			spin_unlock_bh(&tcp_md5sig_pool_lock);
-			return NULL;
-		}
-		pool = tcp_md5sig_pool;
-		if (pool) {
-			/* oops, it has already been assigned. */
-			spin_unlock_bh(&tcp_md5sig_pool_lock);
-			__tcp_free_md5sig_pool(p);
-		} else {
-			tcp_md5sig_pool = pool = p;
-			spin_unlock_bh(&tcp_md5sig_pool_lock);
-		}
+	if (unlikely(!tcp_md5sig_pool)) {
+		mutex_lock(&tcp_md5sig_mutex);
+
+		if (!tcp_md5sig_pool)
+			__tcp_alloc_md5sig_pool();
+
+		mutex_unlock(&tcp_md5sig_mutex);
 	}
-	return pool;
+	return tcp_md5sig_pool != NULL;
 }
 EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
 
@@ -3229,28 +3038,15 @@ struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
 	struct tcp_md5sig_pool __percpu *p;
 
 	local_bh_disable();
-
-	spin_lock(&tcp_md5sig_pool_lock);
-	p = tcp_md5sig_pool;
+	p = ACCESS_ONCE(tcp_md5sig_pool);
 	if (p)
-		tcp_md5sig_users++;
-	spin_unlock(&tcp_md5sig_pool_lock);
-
-	if (p)
-		return this_cpu_ptr(p);
+		return __this_cpu_ptr(p);
 
 	local_bh_enable();
 	return NULL;
 }
 EXPORT_SYMBOL(tcp_get_md5sig_pool);
 
-void tcp_put_md5sig_pool(void)
-{
-	local_bh_enable();
-	tcp_free_md5sig_pool();
-}
-EXPORT_SYMBOL(tcp_put_md5sig_pool);
-
 int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
 			const struct tcphdr *th)
 {
@@ -3356,13 +3152,13 @@ static int __init set_thash_entries(char *str)
 }
 __setup("thash_entries=", set_thash_entries);
 
-void tcp_init_mem(struct net *net)
+static void tcp_init_mem(void)
 {
 	unsigned long limit = nr_free_buffer_pages() / 8;
 	limit = max(limit, 128UL);
-	net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
-	net->ipv4.sysctl_tcp_mem[1] = limit;
-	net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;
+	sysctl_tcp_mem[0] = limit / 4 * 3;
+	sysctl_tcp_mem[1] = limit;
+	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
 }
 
 void __init tcp_init(void)
@@ -3396,10 +3192,9 @@ void __init tcp_init(void)
 					&tcp_hashinfo.ehash_mask,
 					0,
 					thash_entries ? 0 : 512 * 1024);
-	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
+	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
 		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
-		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
-	}
+
 	if (inet_ehash_locks_alloc(&tcp_hashinfo))
 		panic("TCP: failed to alloc ehash_locks");
 	tcp_hashinfo.bhash =
@@ -3425,7 +3220,7 @@ void __init tcp_init(void)
 	sysctl_tcp_max_orphans = cnt / 2;
 	sysctl_max_syn_backlog = max(128, cnt / 256);
 
-	tcp_init_mem(&init_net);
+	tcp_init_mem();
 	/* Set per-socket limits to no more than 1/128 the pressure threshold */
 	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
 	max_wshare = min(4UL*1024*1024, limit);