Message ID | 1508207915.31614.87.camel@edumazet-glaptop3.roam.corp.google.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net-next] tcp: fix tcp_xmit_retransmit_queue() after rbtree introduction | expand |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Mon, 16 Oct 2017 19:38:35 -0700 > From: Eric Dumazet <edumazet@google.com> > > I tried to hard avoiding a call to rb_first() (via tcp_rtx_queue_head) > in tcp_xmit_retransmit_queue(). But this was probably too bold. > > Quoting Yuchung : > > We might miss re-arming the RTO if tp->retransmit_skb_hint is not NULL. > This can happen when RACK marks the first packet lost again and resets > tp->retransmit_skb_hint for example (tcp_rack_mark_skb_lost()) > > Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: Yuchung Cheng <ycheng@google.com> Applied.
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 6c74f2a3977876e691e7355045d4a84a98af1e30..53dc1267c85e668d9a6d5d60d24e6101f7a9c56b 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2921,7 +2921,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) void tcp_xmit_retransmit_queue(struct sock *sk) { const struct inet_connection_sock *icsk = inet_csk(sk); - struct sk_buff *skb, *rtx_head = NULL, *hole = NULL; + struct sk_buff *skb, *rtx_head, *hole = NULL; struct tcp_sock *tp = tcp_sk(sk); u32 max_segs; int mib_idx; @@ -2929,11 +2929,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk) if (!tp->packets_out) return; - skb = tp->retransmit_skb_hint; - if (!skb) { - rtx_head = tcp_rtx_queue_head(sk); - skb = rtx_head; - } + rtx_head = tcp_rtx_queue_head(sk); + skb = tp->retransmit_skb_hint ?: rtx_head; max_segs = tcp_tso_segs(sk, tcp_current_mss(sk)); skb_rbtree_walk_from(skb) { __u8 sacked;