Commit 55f9eca4 authored by Cong Wang's avatar Cong Wang Committed by Paolo Abeni
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sch_qfq: make qfq_qlen_notify() idempotent 



qfq_qlen_notify() always deletes its class from its active list
with list_del_init() _and_ calls qfq_deactivate_agg() when the whole list
becomes empty.

To make it idempotent, just skip everything when it is not in the active
list.

Also change other list_del()'s to list_del_init() just to be extra safe.

Reported-by: default avatarGerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-5-xiyou.wangcong@gmail.com


Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 51eb3b65

net/sched/sch_qfq.c

+5 −2
Original line number Diff line number Diff line
@@ -347,7 +347,7 @@ static void qfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl) 
	struct qfq_aggregate *agg = cl->agg;





	list_del(&cl->alist); /* remove from RR queue of the aggregate */

	list_del_init(&cl->alist); /* remove from RR queue of the aggregate */

	if (list_empty(&agg->active)) /* agg is now inactive */

		qfq_deactivate_agg(q, agg);

}
@@ -474,6 +474,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, 
	gnet_stats_basic_sync_init(&cl->bstats);

	cl->common.classid = classid;

	cl->deficit = lmax;

	INIT_LIST_HEAD(&cl->alist);



	cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,

				      classid, NULL);
@@ -982,7 +983,7 @@ static struct sk_buff *agg_dequeue(struct qfq_aggregate *agg, 
	cl->deficit -= (int) len;



	if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */

		list_del(&cl->alist);

		list_del_init(&cl->alist);

	else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) {

		cl->deficit += agg->lmax;

		list_move_tail(&cl->alist, &agg->active);
@@ -1415,6 +1416,8 @@ static void qfq_qlen_notify(struct Qdisc *sch, unsigned long arg) 
	struct qfq_sched *q = qdisc_priv(sch);

	struct qfq_class *cl = (struct qfq_class *)arg;



	if (list_empty(&cl->alist))

		return;

	qfq_deactivate_class(q, cl);

}