tcp: Honor the eor bit in tcp_mtu_probe

Avoid SKB coalescing if eor bit is set in one of the relevant
SKBs.

Fixes: c134ecb878 ("tcp: Make use of MSG_EOR in tcp_sendmsg")
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilya Lesokhin 2018-02-12 12:57:04 +02:00 committed by David S. Miller
parent fb23403536
commit 808cf9e38c
1 changed files with 25 additions and 0 deletions

View File

@ -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 {