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_htb.c b/net/sched/sch_htb.c
index 30f9da7..ed92836 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1127,10 +1127,9 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
};
__u32 qlen = 0;
- if (!cl->level && cl->leaf.q) {
- qlen = cl->leaf.q->q.qlen;
- qs.backlog = cl->leaf.q->qstats.backlog;
- }
+ if (!cl->level && cl->leaf.q)
+ qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);
+
cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),
INT_MIN, INT_MAX);
cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),