1 files changed, 44 insertions, 16 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 7f18262e2326..1db253e36045 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -59,9 +59,6 @@ int sysctl_tcp_limit_output_bytes __read_mostly = 131072;
  */
 int sysctl_tcp_tso_win_divisor __read_mostly = 3;
 
-int sysctl_tcp_mtu_probing __read_mostly = 0;
-int sysctl_tcp_base_mss __read_mostly = TCP_BASE_MSS;
-
 /* By default, RFC2861 behavior.  */
 int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
 
@@ -948,7 +945,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
         skb_orphan(skb);
         skb->sk = sk;
-        skb->destructor = tcp_wfree;
+        skb->destructor = skb_is_tcp_pure_ack(skb) ? sock_wfree : tcp_wfree;
         skb_set_hash_from_sk(skb, sk);
         atomic_add(skb->truesize, &sk->sk_wmem_alloc);
 
@@ -1350,11 +1347,12 @@ void tcp_mtup_init(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct inet_connection_sock *icsk = inet_csk(sk);
+        struct net *net = sock_net(sk);
 
-        icsk->icsk_mtup.enabled = sysctl_tcp_mtu_probing > 1;
+        icsk->icsk_mtup.enabled = net->ipv4.sysctl_tcp_mtu_probing > 1;
         icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) +
                                icsk->icsk_af_ops->net_header_len;
-        icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
+        icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, net->ipv4.sysctl_tcp_base_mss);
         icsk->icsk_mtup.probe_size = 0;
 }
 EXPORT_SYMBOL(tcp_mtup_init);
@@ -2019,7 +2017,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                 if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now)))
                         break;
 
-                if (tso_segs == 1) {
+                if (tso_segs == 1 || !max_segs) {
                         if (unlikely(!tcp_nagle_test(tp, skb, mss_now,
                                                      (tcp_skb_is_last(sk, skb) ?
                                                       nonagle : TCP_NAGLE_PUSH))))
@@ -2032,7 +2030,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                 }
 
                 limit = mss_now;
-                if (tso_segs > 1 && !tcp_urg_mode(tp))
+                if (tso_segs > 1 && max_segs && !tcp_urg_mode(tp))
                         limit = tcp_mss_split_point(sk, skb, mss_now,
                                                     min_t(unsigned int,
                                                           cwnd_quota,
@@ -2775,15 +2773,11 @@ void tcp_send_fin(struct sock *sk)
         } else {
                 /* Socket is locked, keep trying until memory is available. */
                 for (;;) {
-                        skb = alloc_skb_fclone(MAX_TCP_HEADER,
-                                               sk->sk_allocation);
+                        skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
                         if (skb)
                                 break;
                         yield();
                 }
-
-                /* Reserve space for headers and prepare control bits. */
-                skb_reserve(skb, MAX_TCP_HEADER);
                 /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
                 tcp_init_nondata_skb(skb, tp->write_seq,
                                      TCPHDR_ACK | TCPHDR_FIN);
@@ -2939,6 +2933,25 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 }
 EXPORT_SYMBOL(tcp_make_synack);
 
+static void tcp_ca_dst_init(struct sock *sk, const struct dst_entry *dst)
+{
+        struct inet_connection_sock *icsk = inet_csk(sk);
+        const struct tcp_congestion_ops *ca;
+        u32 ca_key = dst_metric(dst, RTAX_CC_ALGO);
+
+        if (ca_key == TCP_CA_UNSPEC)
+                return;
+
+        rcu_read_lock();
+        ca = tcp_ca_find_key(ca_key);
+        if (likely(ca && try_module_get(ca->owner))) {
+                module_put(icsk->icsk_ca_ops->owner);
+                icsk->icsk_ca_dst_locked = tcp_ca_dst_locked(dst);
+                icsk->icsk_ca_ops = ca;
+        }
+        rcu_read_unlock();
+}
+
 /* Do all connect socket setups that can be done AF independent. */
 static void tcp_connect_init(struct sock *sk)
 {
@@ -2964,6 +2977,8 @@ static void tcp_connect_init(struct sock *sk)
         tcp_mtup_init(sk);
         tcp_sync_mss(sk, dst_mtu(dst));
 
+        tcp_ca_dst_init(sk, dst);
+
         if (!tp->window_clamp)
                 tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
         tp->advmss = dst_metric_advmss(dst);
@@ -3034,7 +3049,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct tcp_fastopen_request *fo = tp->fastopen_req;
-        int syn_loss = 0, space, err = 0;
+        int syn_loss = 0, space, err = 0, copied;
         unsigned long last_syn_loss = 0;
         struct sk_buff *syn_data;
 
@@ -3072,11 +3087,16 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
                 goto fallback;
         syn_data->ip_summed = CHECKSUM_PARTIAL;
         memcpy(syn_data->cb, syn->cb, sizeof(syn->cb));
-        if (unlikely(memcpy_fromiovecend(skb_put(syn_data, space),
-                                         fo->data->msg_iter.iov, 0, space))) {
+        copied = copy_from_iter(skb_put(syn_data, space), space,
+                                &fo->data->msg_iter);
+        if (unlikely(!copied)) {
                 kfree_skb(syn_data);
                 goto fallback;
         }
+        if (copied != space) {
+                skb_trim(syn_data, copied);
+                space = copied;
+        }
 
         /* No more data pending in inet_wait_for_connect() */
         if (space == fo->size)
@@ -3244,6 +3264,14 @@ void tcp_send_ack(struct sock *sk)
         skb_reserve(buff, MAX_TCP_HEADER);
         tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK);
 
+        /* We do not want pure acks influencing TCP Small Queues or fq/pacing
+         * too much.
+         * SKB_TRUESIZE(max(1 .. 66, MAX_TCP_HEADER)) is unfortunately ~784
+         * We also avoid tcp_wfree() overhead (cache line miss accessing
+         * tp->tsq_flags) by using regular sock_wfree()
+         */
+        skb_set_tcp_pure_ack(buff);
+
         /* Send it off, this clears delayed acks for us. */
         skb_mstamp_get(&buff->skb_mstamp);
         tcp_transmit_skb(sk, buff, 0, sk_gfp_atomic(sk, GFP_ATOMIC));