1 files changed, 16 insertions, 3 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4af1f5dae9d3..8a645f304e6c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1288,6 +1288,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *buff;
         int nsize, old_factor;
+        long limit;
         int nlen;
         u8 flags;
 
@@ -1298,8 +1299,16 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
         if (nsize < 0)
                 nsize = 0;
 
-        if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf &&
-                     tcp_queue != TCP_FRAG_IN_WRITE_QUEUE)) {
+        /* tcp_sendmsg() can overshoot sk_wmem_queued by one full size skb.
+         * We need some allowance to not penalize applications setting small
+         * SO_SNDBUF values.
+         * Also allow first and last skb in retransmit queue to be split.
+         */
+        limit = sk->sk_sndbuf + 2 * SKB_TRUESIZE(GSO_MAX_SIZE);
+        if (unlikely((sk->sk_wmem_queued >> 1) > limit &&
+                     tcp_queue != TCP_FRAG_IN_WRITE_QUEUE &&
+                     skb != tcp_rtx_queue_head(sk) &&
+                     skb != tcp_rtx_queue_tail(sk))) {
                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG);
                 return -ENOMEM;
         }
@@ -1311,6 +1320,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
         buff = sk_stream_alloc_skb(sk, nsize, gfp, true);
         if (!buff)
                 return -ENOMEM; /* We'll just try again later. */
+        skb_copy_decrypted(buff, skb);
 
         sk->sk_wmem_queued += buff->truesize;
         sk_mem_charge(sk, buff->truesize);
@@ -1865,6 +1875,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
         buff = sk_stream_alloc_skb(sk, 0, gfp, true);
         if (unlikely(!buff))
                 return -ENOMEM;
+        skb_copy_decrypted(buff, skb);
 
         sk->sk_wmem_queued += buff->truesize;
         sk_mem_charge(sk, buff->truesize);
@@ -2042,7 +2053,7 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len)
                 if (len <= skb->len)
                         break;
 
-                if (unlikely(TCP_SKB_CB(skb)->eor))
+                if (unlikely(TCP_SKB_CB(skb)->eor) || tcp_has_tx_tstamp(skb))
                         return false;
 
                 len -= skb->len;
@@ -2134,6 +2145,7 @@ static int tcp_mtu_probe(struct sock *sk)
         sk_mem_charge(sk, nskb->truesize);
 
         skb = tcp_send_head(sk);
+        skb_copy_decrypted(nskb, skb);
 
         TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
         TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
@@ -2158,6 +2170,7 @@ static int tcp_mtu_probe(struct sock *sk)
                          * we need to propagate it to the new skb.
                          */
                         TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor;
+                        tcp_skb_collapse_tstamp(nskb, skb);
                         tcp_unlink_write_queue(skb, sk);
                         sk_wmem_free_skb(sk, skb);
                 } else {