[PATCH] net/sched: hhf: clear heavy-hitter state on reset

[Samuel Moelius]

HHF reset does not clear the classifier state used to identify heavy
hitters.  Packets after reset can therefore be scheduled using flow
history from before the reset.

The reset operation should return the qdisc to an empty state.

Clear the heavy-hitter classifier tables when HHF is reset.

Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@xxxxxxxxxxxxxxx>
---
 net/sched/sch_hhf.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index 96021f52d835..1698c1b54dec 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -461,12 +461,34 @@ static struct sk_buff *hhf_dequeue(struct Qdisc *sch)
 	return skb;
 }
 
+static void hhf_reset_classifier(struct hhf_sched_data *q)
+{
+	int i;
+
+	for (i = 0; i < HH_FLOWS_CNT; i++) {
+		struct hh_flow_state *flow, *next;
+		struct list_head *head = &q->hh_flows[i];
+
+		list_for_each_entry_safe(flow, next, head, flowchain) {
+			list_del(&flow->flowchain);
+			kfree(flow);
+		}
+	}
+	WRITE_ONCE(q->hh_flows_current_cnt, 0);
+
+	for (i = 0; i < HHF_ARRAYS_CNT; i++)
+		bitmap_zero(q->hhf_valid_bits[i], HHF_ARRAYS_LEN);
+	q->hhf_arrays_reset_timestamp = hhf_time_stamp();
+}
+
 static void hhf_reset(struct Qdisc *sch)
 {
+	struct hhf_sched_data *q = qdisc_priv(sch);
 	struct sk_buff *skb;
 
 	while ((skb = hhf_dequeue(sch)) != NULL)
 		rtnl_kfree_skbs(skb, skb);
+	hhf_reset_classifier(q);
 }
 
 static void hhf_destroy(struct Qdisc *sch)
-- 
2.43.0