[PATCH 4.19 115/140] sch_cake: Correctly update parent qlen when splitting GSO packets

[Greg Kroah-Hartman]

From: Toke HÃiland-JÃrgensen <toke@xxxxxxxxxx>

[ Upstream commit 8c6c37fdc20ec9ffaa342f827a8e20afe736fb0c ]

To ensure parent qdiscs have the same notion of the number of enqueued
packets even after splitting a GSO packet, update the qdisc tree with the
number of packets that was added due to the split.

Reported-by: Pete Heist <pete@xxxxxxxxxx>
Tested-by: Pete Heist <pete@xxxxxxxxxx>
Signed-off-by: Toke HÃiland-JÃrgensen <toke@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/sched/sch_cake.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 9fd37d91b5ed0..e4cf72b0675e1 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1666,7 +1666,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) {
 		struct sk_buff *segs, *nskb;
 		netdev_features_t features = netif_skb_features(skb);
-		unsigned int slen = 0;
+		unsigned int slen = 0, numsegs = 0;
 
 		segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
 		if (IS_ERR_OR_NULL(segs))
@@ -1682,6 +1682,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			flow_queue_add(flow, segs);
 
 			sch->q.qlen++;
+			numsegs++;
 			slen += segs->len;
 			q->buffer_used += segs->truesize;
 			b->packets++;
@@ -1695,7 +1696,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		sch->qstats.backlog += slen;
 		q->avg_window_bytes += slen;
 
-		qdisc_tree_reduce_backlog(sch, 1, len);
+		qdisc_tree_reduce_backlog(sch, 1-numsegs, len-slen);
 		consume_skb(skb);
 	} else {
 		/* not splitting */
-- 
2.20.1