sch_cake: Correctly update parent qlen when splitting GSO packets

[ 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@heistp.net>
Tested-by: Pete Heist <pete@heistp.net>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 9fd37d91b5ed0e7588d786ae176d885a072dce37..e4cf72b0675e17ae441f1685a9cc605ce17fff40 100644 (file)
--- 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 */