Commit 7a998933 authored by zhang kai's avatar zhang kai Committed by Zhengchao Shao
Browse files

tcp: tcp_mark_head_lost is only valid for sack-tcp 

stable inclusion
from stable-v4.19.318
commit 552970cb728120695820ef9decb0933b3f9ce774
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAMPH5

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=552970cb728120695820ef9decb0933b3f9ce774



---------------------------

[ Upstream commit 636ef28d ]

so tcp_is_sack/reno checks are removed from tcp_mark_head_lost.

Signed-off-by: default avatarzhang kai <zhangkaiheb@126.com>
Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Stable-dep-of: a6458ab7fd4f ("UPSTREAM: tcp: fix DSACK undo in fast recovery to call tcp_try_to_open()")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZhengchao Shao <shaozhengchao@huawei.com>
parent 8b4c3288

net/ipv4/tcp_input.c

+7 −25
Original line number Diff line number Diff line
@@ -2189,8 +2189,7 @@ static bool tcp_time_to_recover(struct sock *sk, int flag) 
}



/* Detect loss in event "A" above by marking head of queue up as lost.

 * For non-SACK(Reno) senders, the first "packets" number of segments

 * are considered lost. For RFC3517 SACK, a segment is considered lost if it

 * For RFC3517 SACK, a segment is considered lost if it

 * has at least tp->reordering SACKed seqments above it; "packets" refers to

 * the maximum SACKed segments to pass before reaching this limit.

 */
@@ -2198,10 +2197,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head) 
{

	struct tcp_sock *tp = tcp_sk(sk);

	struct sk_buff *skb;

	int cnt, oldcnt, lost;

	unsigned int mss;

	int cnt;

	/* Use SACK to deduce losses of new sequences sent during recovery */

	const u32 loss_high = tcp_is_sack(tp) ?  tp->snd_nxt : tp->high_seq;

	const u32 loss_high = tp->snd_nxt;



	WARN_ON(packets > tp->packets_out);

	skb = tp->lost_skb_hint;
@@ -2224,26 +2222,11 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head) 
		if (after(TCP_SKB_CB(skb)->end_seq, loss_high))

			break;



		oldcnt = cnt;

		if (tcp_is_reno(tp) ||

		    (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))

		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)

			cnt += tcp_skb_pcount(skb);



		if (cnt > packets) {

			if (tcp_is_sack(tp) ||

			    (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) ||

			    (oldcnt >= packets))

				break;



			mss = tcp_skb_mss(skb);

			/* If needed, chop off the prefix to mark as lost. */

			lost = (packets - oldcnt) * mss;

			if (lost < skb->len &&

			    tcp_fragment(sk, TCP_FRAG_IN_RTX_QUEUE, skb,

					 lost, mss, GFP_ATOMIC) < 0)

		if (cnt > packets)

			break;

			cnt = packets;

		}



		tcp_skb_mark_lost(tp, skb);
@@ -2871,8 +2854,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una, 
			if (tcp_try_undo_partial(sk, prior_snd_una))

				return;

			/* Partial ACK arrived. Force fast retransmit. */

			do_lost = tcp_is_reno(tp) ||

				  tcp_force_fast_retransmit(sk);

			do_lost = tcp_force_fast_retransmit(sk);

		}

		if (tcp_try_undo_dsack(sk)) {

			tcp_try_keep_open(sk);