[PATCH v3 net-next 07/12] tcp: move increment of num_retrans
From: <hidden>
Date: 2025-09-27 08:48:24
Also in:
bpf, linux-doc, linux-kselftest
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Chia-Yu Chang <redacted> Before this patch, num_retrans = 0 for the first SYN/ACK and the first retransmitted SYN/ACK; however, an upcoming change will need to differentiate between those two conditions. This patch moves the increment of num_tranns before rtx_syn_ack() so we can distinguish between these two cases when making SYN/ACK. Signed-off-by: Chia-Yu Chang <redacted> --- net/ipv4/tcp_output.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 6e6fea8f295b..ef008736e3a9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c@@ -4593,6 +4593,7 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) /* Paired with WRITE_ONCE() in sock_setsockopt() */ if (READ_ONCE(sk->sk_txrehash) == SOCK_TXREHASH_ENABLED) WRITE_ONCE(tcp_rsk(req)->txhash, net_tx_rndhash()); + WRITE_ONCE(req->num_retrans, req->num_retrans + 1); res = af_ops->send_synack(sk, NULL, &fl, req, NULL, TCP_SYNACK_NORMAL, NULL); if (!res) {
@@ -4606,7 +4607,8 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req) tcp_sk_rw(sk)->total_retrans++; } trace_tcp_retransmit_synack(sk, req); - WRITE_ONCE(req->num_retrans, req->num_retrans + 1); + } else { + WRITE_ONCE(req->num_retrans, req->num_retrans - 1); } return res; }
--
2.34.1