tcp: use correct counters in CA_CWR state too (c60ce4e2) · Commits · 戴 / test

As CWR is stronger than CA_Disorder state, we can miscount SACK/Reno failure into other timeouts. Not a bad problem as it can happen only due to ECN, FRTO detecting spurious RTO or xmit error which are the only callers of tcp_enter_cwr. And even then losses and RTO must still follow thereafter to actually end up into the relevant code paths. Compile tested. Signed-off-by:

Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp_timer.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -367,18 +367,19 @@ void tcp_retransmit_timer(struct sock *sk)
		if (icsk->icsk_retransmits == 0) {
		int mib_idx;

		if (icsk->icsk_ca_state == TCP_CA_Disorder) {
		if (tcp_is_sack(tp))
		mib_idx = LINUX_MIB_TCPSACKFAILURES;
		else
		mib_idx = LINUX_MIB_TCPRENOFAILURES;
		} else if (icsk->icsk_ca_state == TCP_CA_Recovery) {
		if (icsk->icsk_ca_state == TCP_CA_Recovery) {
		if (tcp_is_sack(tp))
		mib_idx = LINUX_MIB_TCPSACKRECOVERYFAIL;
		else
		mib_idx = LINUX_MIB_TCPRENORECOVERYFAIL;
		} else if (icsk->icsk_ca_state == TCP_CA_Loss) {
		mib_idx = LINUX_MIB_TCPLOSSFAILURES;
		} else if ((icsk->icsk_ca_state == TCP_CA_Disorder) \|\|
		tp->sacked_out) {
		if (tcp_is_sack(tp))
		mib_idx = LINUX_MIB_TCPSACKFAILURES;
		else
		mib_idx = LINUX_MIB_TCPRENOFAILURES;
		} else {
		mib_idx = LINUX_MIB_TCPTIMEOUTS;
		}

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