Commit 808cf9e3 authored by Ilya Lesokhin's avatar Ilya Lesokhin Committed by David S. Miller
Browse files

tcp: Honor the eor bit in tcp_mtu_probe 



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

Fixes: c134ecb8 ("tcp: Make use of MSG_EOR in tcp_sendmsg")
Signed-off-by: default avatarIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fb234035

net/ipv4/tcp_output.c

+25 −0
Original line number Diff line number Diff line
@@ -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 {