[RFC v2 19/24] net: wipe the setting of deactived queues

[Pavel Begunkov <asml.silence@gmail.com>]

From: Jakub Kicinski <kuba@kernel.org>

Clear out all settings of deactived queues when user changes
the number of channels. We already perform similar cleanup
for shapers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 net/core/dev.c           |  5 +++++
 net/core/dev.h           |  2 ++
 net/core/netdev_config.c | 13 +++++++++++++
 3 files changed, 20 insertions(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index 8e9af8469421..01264c284c84 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3188,6 +3188,8 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
 		if (dev->num_tc)
 			netif_setup_tc(dev, txq);
 
+		netdev_queue_config_update_cnt(dev, txq,
+					       dev->real_num_rx_queues);
 		net_shaper_set_real_num_tx_queues(dev, txq);
 
 		dev_qdisc_change_real_num_tx(dev, txq);
@@ -3233,6 +3235,9 @@ int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
 						  rxq);
 		if (rc)
 			return rc;
+
+		netdev_queue_config_update_cnt(dev, dev->real_num_tx_queues,
+					       rxq);
 	}
 
 	dev->real_num_rx_queues = rxq;
diff --git a/net/core/dev.h b/net/core/dev.h
index f51b66403466..a33d8a507bed 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -101,6 +101,8 @@ void __netdev_queue_config(struct net_device *dev, int rxq,
 			   struct netdev_queue_config *qcfg, bool pending);
 int netdev_queue_config_revalidate(struct net_device *dev,
 				   struct netlink_ext_ack *extack);
+void netdev_queue_config_update_cnt(struct net_device *dev, unsigned int txq,
+				    unsigned int rxq);
 
 /* netdev management, shared between various uAPI entry points */
 struct netdev_name_node {
diff --git a/net/core/netdev_config.c b/net/core/netdev_config.c
index ede02b77470e..c5ae39e76f40 100644
--- a/net/core/netdev_config.c
+++ b/net/core/netdev_config.c
@@ -64,6 +64,19 @@ int netdev_reconfig_start(struct net_device *dev)
 	return -ENOMEM;
 }
 
+void netdev_queue_config_update_cnt(struct net_device *dev, unsigned int txq,
+				    unsigned int rxq)
+{
+	size_t len;
+
+	if (rxq < dev->real_num_rx_queues) {
+		len = (dev->real_num_rx_queues - rxq) * sizeof(*dev->cfg->qcfg);
+
+		memset(&dev->cfg->qcfg[rxq], 0, len);
+		memset(&dev->cfg_pending->qcfg[rxq], 0, len);
+	}
+}
+
 void __netdev_queue_config(struct net_device *dev, int rxq,
 			   struct netdev_queue_config *qcfg, bool pending)
 {
-- 
2.49.0