target/linux/generic/backport-4.19/391-v5.1-sch_cake-Correctly-update-parent-qlen-when-splitting.patch

   1 From 8c6c37fdc20ec9ffaa342f827a8e20afe736fb0c Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
   3 Date: Wed, 9 Jan 2019 17:09:44 +0100
   4 Subject: [PATCH] sch_cake: Correctly update parent qlen when splitting GSO
   5  packets
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 To ensure parent qdiscs have the same notion of the number of enqueued
  11 packets even after splitting a GSO packet, update the qdisc tree with the
  12 number of packets that was added due to the split.
  13
  14 Reported-by: Pete Heist <pete@heistp.net>
  15 Tested-by: Pete Heist <pete@heistp.net>
  16 Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
  17 Signed-off-by: David S. Miller <davem@davemloft.net>
  18 Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
  19 ---
  20  net/sched/sch_cake.c | 5 +++--
  21  1 file changed, 3 insertions(+), 2 deletions(-)
  22
  23 --- a/net/sched/sch_cake.c
  24 +++ b/net/sched/sch_cake.c
  25 @@ -1666,7 +1666,7 @@ static s32 cake_enqueue(struct sk_buff *
  26         if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) {
  27                 struct sk_buff *segs, *nskb;
  28                 netdev_features_t features = netif_skb_features(skb);
  29 -               unsigned int slen = 0;
  30 +               unsigned int slen = 0, numsegs = 0;
  31
  32                 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
  33                 if (IS_ERR_OR_NULL(segs))
  34 @@ -1682,6 +1682,7 @@ static s32 cake_enqueue(struct sk_buff *
  35                         flow_queue_add(flow, segs);
  36
  37                         sch->q.qlen++;
  38 +                       numsegs++;
  39                         slen += segs->len;
  40                         q->buffer_used += segs->truesize;
  41                         b->packets++;
  42 @@ -1695,7 +1696,7 @@ static s32 cake_enqueue(struct sk_buff *
  43                 sch->qstats.backlog += slen;
  44                 q->avg_window_bytes += slen;
  45
  46 -               qdisc_tree_reduce_backlog(sch, 1, len);
  47 +               qdisc_tree_reduce_backlog(sch, 1-numsegs, len-slen);
  48                 consume_skb(skb);
  49         } else {
  50                 /* not splitting */