From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konstantin Khlebnikov , "David S. Miller" Subject: [PATCH 4.17 030/101] net_sched: blackhole: tell upper qdisc about dropped packets Date: Fri, 20 Jul 2018 14:13:36 +0200 Message-Id: <20180720121424.239595632@linuxfoundation.org> In-Reply-To: <20180720121422.837870592@linuxfoundation.org> References: <20180720121422.837870592@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konstantin Khlebnikov [ Upstream commit 7e85dc8cb35abf16455f1511f0670b57c1a84608 ] When blackhole is used on top of classful qdisc like hfsc it breaks qlen and backlog counters because packets are disappear without notice. In HFSC non-zero qlen while all classes are inactive triggers warning: WARNING: ... at net/sched/sch_hfsc.c:1393 hfsc_dequeue+0xba4/0xe90 [sch_hfsc] and schedules watchdog work endlessly. This patch return __NET_XMIT_BYPASS in addition to NET_XMIT_SUCCESS, this flag tells upper layer: this packet is gone and isn't queued. Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_blackhole.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/sch_blackhole.c +++ b/net/sched/sch_blackhole.c @@ -21,7 +21,7 @@ static int blackhole_enqueue(struct sk_b struct sk_buff **to_free) { qdisc_drop(skb, sch, to_free); - return NET_XMIT_SUCCESS; + return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; } static struct sk_buff *blackhole_dequeue(struct Qdisc *sch)