fq_codel: fix memory limitation drift

memory_usage must be decreased in dequeue_func(), not in
fq_codel_dequeue(), otherwise packets dropped by Codel algo
are missing this decrease.

Also we need to clear memory_usage in fq_codel_reset()

Fixes: 95b58430abe7 ("fq_codel: add memory limitation per queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index bb8bd9314629..6883a8971562 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -262,6 +262,7 @@ static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx)
         if (flow->head) {
                 skb = dequeue_head(flow);
                 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
+                q->memory_usage -= skb->truesize;
                 sch->q.qlen--;
                 sch->qstats.backlog -= qdisc_pkt_len(skb);
         }
@@ -318,7 +319,6 @@ begin:
                         list_del_init(&flow->flowchain);
                 goto begin;
         }
-        q->memory_usage -= skb->truesize;
         qdisc_bstats_update(sch, skb);
         flow->deficit -= qdisc_pkt_len(skb);
         /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
@@ -355,6 +355,7 @@ static void fq_codel_reset(struct Qdisc *sch)
         }
         memset(q->backlogs, 0, q->flows_cnt * sizeof(u32));
         sch->q.qlen = 0;
+        q->memory_usage = 0;
 }
 
 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {