Commit 6bcfd7f8 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

tcp: fix RFS vs lockless listeners

Before recent TCP listener patches, we were updating listener
sk->sk_rxhash before the cloning of master socket.

children sk_rxhash was therefore correct after the normal 3WHS.

But with lockless listener, we no longer dirty/change listener sk_rxhash
as it would be racy.

We need to correctly update the child sk_rxhash, otherwise first data
packet wont hit correct cpu if RFS is used.

Fixes: 079096f1 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: default avatarEric Dumazet <>
Reported-by: default avatarWillem de Bruijn <>
Cc: Tom Herbert <>
Acked-by: default avatarTom Herbert <>
Signed-off-by: default avatarDavid S. Miller <>
parent 5010ea59
......@@ -225,6 +225,7 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb,
child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst);
if (child) {
atomic_set(&req->rsk_refcnt, 1);
sock_rps_save_rxhash(child, skb);
inet_csk_reqsk_queue_add(sk, req, child);
} else {
......@@ -768,6 +768,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
if (!child)
goto listen_overflow;
sock_rps_save_rxhash(child, skb);
tcp_synack_rtt_meas(child, req);
inet_csk_reqsk_queue_drop(sk, req);
inet_csk_reqsk_queue_add(sk, req, child);
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