[PATCH 4.19 292/321] net: sched: fix `tc -s class show` no bstats on class with nolock subqueues

Greg Kroah-Hartman
2019-12-03T22:57:52Z

From: Dust Li <dust.li@linux.alibaba.com>

[ Upstream commit 14e54ab9143fa60794d13ea0a66c792a2046a8f3 ]

When a classful qdisc's child qdisc has set the flag
TCQ_F_CPUSTATS (pfifo_fast for example), the child qdisc's
cpu_bstats should be passed to gnet_stats_copy_basic(),
but many classful qdisc didn't do that. As a result,
`tc -s class show dev DEV` always return 0 for bytes and
packets in this case.

Pass the child qdisc's cpu_bstats to gnet_stats_copy_basic()
to fix this issue.

The qstats also has this problem, but it has been fixed
in 5dd431b6b9 ("net: sched: introduce and use qstats read...")
and bstats still remains buggy.

Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sched/sch_mq.c | 3 ++-
net/sched/sch_mqprio.c | 4 ++--
net/sched/sch_multiq.c | 2 +-
net/sched/sch_prio.c | 2 +-
4 files changed, 6 insertions(+), 5 deletions(-)

--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -242,7 +242,8 @@ static int mq_dump_class_stats(struct Qd
struct netdev_queue *dev_queue = mq_queue_get(sch, cl);

sch = dev_queue->qdisc_sleeping;
- if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
+ if (gnet_stats_copy_basic(&sch->running, d, sch->cpu_bstats,
+ &sch->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0)
return -1;
return 0;
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -559,8 +559,8 @@ static int mqprio_dump_class_stats(struc
struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);

sch = dev_queue->qdisc_sleeping;
- if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
- d, NULL, &sch->bstats) < 0 ||
+ if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
+ sch->cpu_bstats, &sch->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL,
&sch->qstats, sch->q.qlen) < 0)
return -1;
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -343,7 +343,7 @@ static int multiq_dump_class_stats(struc

cl_q = q->queues[cl - 1];
if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
- d, NULL, &cl_q->bstats) < 0 ||
+ d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
return -1;

--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -396,7 +396,7 @@ static int prio_dump_class_stats(struct

cl_q = q->queues[cl - 1];
if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
- d, NULL, &cl_q->bstats) < 0 ||
+ d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
return -1;