Commit a8688821 authored by Cong Wang's avatar Cong Wang Committed by Jakub Kicinski
Browse files

tcp: refactor tcp_read_skb() a bit 



As tcp_read_skb() only reads one skb at a time, the while loop is
unnecessary, we can turn it into an if. This also simplifies the
code logic.

Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c457985a

net/ipv4/tcp.c

+9 −17
Original line number Diff line number Diff line
@@ -1761,25 +1761,17 @@ int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor) 
	if (sk->sk_state == TCP_LISTEN)

		return -ENOTCONN;



	while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {

		int used;

	skb = tcp_recv_skb(sk, seq, &offset);

	if (!skb)

		return 0;



	__skb_unlink(skb, &sk->sk_receive_queue);

	WARN_ON(!skb_set_owner_sk_safe(skb, sk));

		used = recv_actor(sk, skb);

		if (used <= 0) {

			if (!copied)

				copied = used;

			break;

		}

		seq += used;

		copied += used;



		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {

	copied = recv_actor(sk, skb);

	if (copied > 0) {

		seq += copied;

		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)

			++seq;

			break;

		}

		break;

	}

	consume_skb(skb);

	WRITE_ONCE(tp->copied_seq, seq);