From 4cda75275f9f89f9485b0ca4d6950c95258a9bce Mon Sep 17 00:00:00 2001
From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Tue, 10 Mar 2020 17:53:35 +0100
Subject: [PATCH] net: sched: make newly activated qdiscs visible
In their .attach callback, mq[prio] only add the qdiscs of the currently
active TX queues to the device's qdisc hash list.
If a user later increases the number of active TX queues, their qdiscs
are not visible via eg. 'tc qdisc show'.
Add a hook to netif_set_real_num_tx_queues() that walks all active
TX queues and adds those which are missing to the hash list.
CC: Eric Dumazet <edumazet@google.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
CC: Cong Wang <xiyou.wangcong@gmail.com>
CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/sch_generic.h | 6 ++++++
net/core/dev.c | 1 +
net/sched/sch_generic.c | 21 +++++++++++++++++++++
3 files changed, 28 insertions(+)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 151208704ed2..7bfc45c5b602 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -153,6 +153,11 @@ static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
return !READ_ONCE(qdisc->q.qlen);
}
+static inline bool qdisc_hashed(struct Qdisc *qdisc)
+{
+ return hash_hashed(&qdisc->hash);
+}
+
static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK) {
@@ -629,6 +634,7 @@ void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
int dev_qdisc_change_tx_queue_len(struct net_device *dev);
+void dev_qdisc_set_real_num_tx_queues(struct net_device *dev);
void dev_init_scheduler(struct net_device *dev);
void dev_shutdown(struct net_device *dev);
void dev_activate(struct net_device *dev);
diff --git a/net/core/dev.c b/net/core/dev.c
index 25dab1598803..ccc03abeee52 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2875,6 +2875,7 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
netif_setup_tc(dev, txq);
dev->real_num_tx_queues = txq;
+ dev_qdisc_set_real_num_tx_queues(dev);
if (disabling) {
synchronize_net();
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 6c9595f1048a..36a40ebcf0ee 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1268,6 +1268,27 @@ int dev_qdisc_change_tx_queue_len(struct net_device *dev)
return ret;
}
+void dev_qdisc_set_real_num_tx_queues(struct net_device *dev)
+{
+#ifdef CONFIG_NET_SCHED
+ struct Qdisc *sch = dev->qdisc;
+ unsigned int ntx;
+
+ if (!sch)
+ return;
+
+ ASSERT_RTNL();
+
+ for (ntx = 0; ntx < dev->real_num_tx_queues; ntx++) {
+ struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
+ struct Qdisc *qdisc = dev_queue->qdisc;
+
+ if (qdisc && !qdisc_hashed(qdisc))
+ qdisc_hash_add(qdisc, false);
+ }
+#endif
+}
+
static void dev_init_scheduler_queue(struct net_device *dev,
struct netdev_queue *dev_queue,
void *_qdisc)