sch_qfq: make qfq_qlen_notify() idempotent

commit 55f9eca4bfe30a15d8656f915922e8c98b7f0728 upstream.

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: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-5-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Cong Wang
2025-04-03 14:10:26 -07:00
committed by Greg Kroah-Hartman
parent 9030a91235
commit 3626915603

View File

@@ -352,7 +352,7 @@ 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);
}
@@ -482,6 +482,7 @@ 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);
@@ -990,7 +991,7 @@ 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);
@@ -1421,6 +1422,8 @@ 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);
}