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[RFC,net-next,4/6] net: Do not intialize kobject for lightweight netdevs

Message ID 20170506160734.47084-5-dsahern@gmail.com
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

David Ahern May 6, 2017, 4:07 p.m. UTC 
Lightweight netdevices are not added to sysfs; bypass kobject
initialization.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/linux/netdevice.h |  3 +++
 net/core/dev.c            |  9 ++++++---
 net/core/net-sysfs.c      | 14 +++++++++++---
 3 files changed, 20 insertions(+), 6 deletions(-)

Comments

Florian Fainelli May 8, 2017, 5:26 p.m. UTC | #1 
On 05/06/2017 09:07 AM, David Ahern wrote:
> Lightweight netdevices are not added to sysfs; bypass kobject
> initialization.

I was wondering if we actually needed a flag to tell: this is a
lightweight device, but still let it show up in /sys. All use cases that
I have in mind (getting the physical port name etc. etc) can be done via
netlink which is not restricted even with LWT devices, so this sounds
reasonable. In case we need to revisit that, we can always add more
flags to control the lightweight devices creation and how this
percolates through the networking stack.

Thanks!
diff mbox

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 08151fd34973..4ddd0ac7e1cb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4282,6 +4282,9 @@  static inline const char *netdev_reg_state(const struct net_device *dev)
 
 static inline struct kobject *netdev_kobject(struct net_device *dev)
 {
+	if (netif_is_lwd(dev))
+		return NULL;
+
 	return &dev->dev.kobj;
 }
 
diff --git a/net/core/dev.c b/net/core/dev.c
index 48a0252037d5..52bb01041d12 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7993,7 +7993,8 @@  void free_netdev(struct net_device *dev)
 	dev->reg_state = NETREG_RELEASED;
 
 	/* will free via device release */
-	put_device(&dev->dev);
+	if (!netif_is_lwd(dev))
+		put_device(&dev->dev);
 }
 EXPORT_SYMBOL(free_netdev);
 
@@ -8179,8 +8180,10 @@  int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	netdev_adjacent_add_links(dev);
 
 	/* Fixup kobjects */
-	err = device_rename(&dev->dev, dev->name);
-	WARN_ON(err);
+	if (!netif_is_lwd(dev)) {
+		err = device_rename(&dev->dev, dev->name);
+		WARN_ON(err);
+	}
 
 	/* Add the device back in the hashes */
 	list_netdevice(dev);
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 9df53b688f5b..725348cdeb3b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1559,18 +1559,22 @@  EXPORT_SYMBOL(of_find_net_device_by_node);
  */
 void netdev_unregister_kobject(struct net_device *ndev)
 {
+	struct kobject *kobj = netdev_kobject(ndev);
 	struct device *dev = &(ndev->dev);
 
 	if (!atomic_read(&dev_net(ndev)->count))
 		dev_set_uevent_suppress(dev, 1);
 
-	kobject_get(&dev->kobj);
+	if (kobj)
+		kobject_get(kobj);
 
-	remove_queue_kobjects(ndev);
+	if (!netif_is_lwd(ndev))
+		remove_queue_kobjects(ndev);
 
 	pm_runtime_set_memalloc_noio(dev, false);
 
-	device_del(dev);
+	if (!netif_is_lwd(ndev))
+		device_del(dev);
 }
 
 /* Create sysfs entries for network device. */
@@ -1580,6 +1584,9 @@  int netdev_register_kobject(struct net_device *ndev)
 	const struct attribute_group **groups = ndev->sysfs_groups;
 	int error = 0;
 
+	if (netif_is_lwd(ndev))
+		goto pm;
+
 	device_initialize(dev);
 	dev->class = &net_class;
 	dev->platform_data = ndev;
@@ -1614,6 +1621,7 @@  int netdev_register_kobject(struct net_device *ndev)
 		return error;
 	}
 
+pm:
 	pm_runtime_set_memalloc_noio(dev, true);
 
 	return error;