diff options
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e9f985e42405..b2bca373f8be 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2027,6 +2027,24 @@ static inline void tcp_mtu_check_reprobe(struct sock *sk) } } +static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len) +{ + struct sk_buff *skb, *next; + + skb = tcp_send_head(sk); + tcp_for_write_queue_from_safe(skb, next, sk) { + if (len <= skb->len) + break; + + if (unlikely(TCP_SKB_CB(skb)->eor)) + return false; + + len -= skb->len; + } + + return true; +} + /* Create a new MTU probe if we are ready. * MTU probe is regularly attempting to increase the path MTU by * deliberately sending larger packets. This discovers routing @@ -2099,6 +2117,9 @@ static int tcp_mtu_probe(struct sock *sk) return 0; } + if (!tcp_can_coalesce_send_queue_head(sk, probe_size)) + return -1; + /* We're allowed to probe. Build it now. */ nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC, false); if (!nskb) @@ -2134,6 +2155,10 @@ static int tcp_mtu_probe(struct sock *sk) /* We've eaten all the data from this skb. * Throw it away. */ TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; + /* If this is the last SKB we copy and eor is set + * we need to propagate it to the new skb. + */ + TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor; tcp_unlink_write_queue(skb, sk); sk_wmem_free_skb(sk, skb); } else { |