Re: [PATCH net 1/1] net: tcp: Increase TCPABORTONLINGER when send RST by linger2 in keepalive timer

[David Miller <davem@davemloft.net>]

From: gfree.wind@foxmail.com
Date: Sun,  9 Apr 2017 20:44:41 +0800

> From: Gao Feng <fgao@ikuai8.com>
> 
> It should increase TCPABORTONLINGER counter when send RST caused by
> linger2 in keepalive timer.
> 
> Signed-off-by: Gao Feng <fgao@ikuai8.com>
> ---
>  net/ipv4/tcp_timer.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
> index b2ab411..5c01f21 100644
> --- a/net/ipv4/tcp_timer.c
> +++ b/net/ipv4/tcp_timer.c
> @@ -650,6 +650,8 @@ static void tcp_keepalive_timer (unsigned long data)
>  				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
>  				goto out;
>  			}
> +		} else {
> +			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONLINGER);
>  		}
>  		tcp_send_active_reset(sk, GFP_ATOMIC);
>  		goto death;

I think this else clause is completely unnecessary.  Just do it right above
the tcp_send_active_reset() call and at the same indentation level.

Alternatively, if you are trying to only bump the counter when tp->linger2 is
>= 0, then you attached the else clause to the wrong if() test.

Thank you.