net: sched: introduce and use qdisc tree flush/purge helpers

The same code to flush qdisc tree and purge the qdisc queue
is duplicated in many places and in most cases it does not
respect NOLOCK qdisc: the global backlog len is used and the
per CPU values are ignored.

This change addresses the above, factoring-out the relevant
code and using the helpers introduced by the previous patch
to fetch the correct backlog len.

Fixes: c5ad119fb6c0 ("net: sched: pfifo_fast use skb_array")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 12 deletions

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index a946a419d717..d2ab463f22ae 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -845,16 +845,6 @@ qdisc_peek_len(struct Qdisc *sch)
 }
 
 static void
-hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
-{
-	unsigned int len = cl->qdisc->q.qlen;
-	unsigned int backlog = cl->qdisc->qstats.backlog;
-
-	qdisc_reset(cl->qdisc);
-	qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
-}
-
-static void
 hfsc_adjust_levels(struct hfsc_class *cl)
 {
 	struct hfsc_class *p;
@@ -1076,7 +1066,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
 	list_add_tail(&cl->siblings, &parent->children);
 	if (parent->level == 0)
-		hfsc_purge_queue(sch, parent);
+		qdisc_purge_queue(parent->qdisc);
 	hfsc_adjust_levels(parent);
 	sch_tree_unlock(sch);
 
@@ -1112,7 +1102,7 @@ hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
 	list_del(&cl->siblings);
 	hfsc_adjust_levels(cl->cl_parent);
 
-	hfsc_purge_queue(sch, cl);
+	qdisc_purge_queue(cl->qdisc);
 	qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
 
 	sch_tree_unlock(sch);