From e1738bd9cecc5c867b0e2996470c1ff20f66ba79 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <eric.dumazet@gmail.com> Date: Fri, 29 Jul 2011 19:22:42 +0000 Subject: [PATCH] sch_sfq: fix sfq_enqueue() commit 8efa88540635 (sch_sfq: avoid giving spurious NET_XMIT_CN signals) forgot to call qdisc_tree_decrease_qlen() to signal upper levels that a packet (from another flow) was dropped, leading to various problems. With help from Michal Soltys and Michal Pokrywka, who did a bisection. Bugzilla ref: https://bugzilla.kernel.org/show_bug.cgi?id=39372 Debian ref: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=631945 Reported-by: Lucas Bocchi <lucas.bocchi@gmail.com> Reported-and-bisected-by: Michal Pokrywka <wolfmoon@o2.pl> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Michal Soltys <soltys@ziu.info> Acked-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/sched/sch_sfq.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 4536ee64383e..4f5510e2bd6f 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -410,7 +410,12 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) /* Return Congestion Notification only if we dropped a packet * from this flow. */ - return (qlen != slot->qlen) ? NET_XMIT_CN : NET_XMIT_SUCCESS; + if (qlen != slot->qlen) + return NET_XMIT_CN; + + /* As we dropped a packet, better let upper stack know this */ + qdisc_tree_decrease_qlen(sch, 1); + return NET_XMIT_SUCCESS; } static struct sk_buff *