netdev - [PATCH net-next 4/6] tcp: tcp_sendmsg() only deals with CHECKSUM

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Date:   Mon, 19 Feb 2018 11:56:50 -0800
From:   Eric Dumazet <edumazet@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Neal Cardwell <ncardwell@...gle.com>,
        Yuchung Cheng <ycheng@...gle.com>,
        Soheil Hassas Yeganeh <soheil@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Oleksandr Natalenko <oleksandr@...alenko.name>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: [PATCH net-next 4/6] tcp: tcp_sendmsg() only deals with CHECKSUM_PARTIAL

We no longer have skbs with skb->ip_summed == CHECKSUM_NONE
in TCP write queues.

We can remove dead code in tcp_sendmsg().

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/ipv4/tcp.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 7c41402718876ef8adc7dc90cd51994e6a4fded9..a33539798bf61b99760b8f5923e3df14cd7400a7 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1254,14 +1254,10 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 
 	while (msg_data_left(msg)) {
 		int copy = 0;
-		int max = size_goal;
 
 		skb = tcp_write_queue_tail(sk);
-		if (skb) {
-			if (skb->ip_summed == CHECKSUM_NONE)
-				max = mss_now;
-			copy = max - skb->len;
-		}
+		if (skb)
+			copy = size_goal - skb->len;
 
 		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
 			bool first_skb;
@@ -1290,7 +1286,6 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 
 			skb_entail(sk, skb);
 			copy = size_goal;
-			max = size_goal;
 
 			/* All packets are restored as if they have
 			 * already been sent. skb_mstamp isn't set to
@@ -1374,7 +1369,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 			goto out;
 		}
 
-		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
+		if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
 			continue;
 
 		if (forced_push(tp)) {
-- 
2.16.1.291.g4437f3f132-goog