net: sched: introduce and use qstats read helpers
Classful qdiscs can't access directly the child qdiscs backlog
length: if such qdisc is NOLOCK, per CPU values should be
accounted instead.
Most qdiscs no not respect the above. As a result, qstats fetching
for most classful qdisc is currently incorrect: if the child qdisc is
NOLOCK, it always reports 0 len backlog.
This change introduces a pair of helpers to safely fetch
both backlog and qlen and use them in stats class dumping
functions, fixing the above issue and cleaning a bit the code.
DRR needs also to access the child qdisc queue length, so it
needs custom handling.
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>
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 206e4db..c704199 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -895,7 +895,7 @@ static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
sch = dev_queue->qdisc_sleeping;
if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
- gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0)
+ qdisc_qstats_copy(d, sch) < 0)
return -1;
return 0;
}