[PATCH net-next 0/2] netvsc: transparent VF related cleanups

[PATCH net-next 0/2] netvsc: transparent VF related cleanups

[Stephen Hemminger]

The first gets rid of unnecessary ref counting, and second
allows removing hv_netvsc driver even if VF present.

Stephen Hemminger (2):
  netvsc: cleanup datapath switch
  netvsc: allow driver to be removed even if VF is present

 drivers/net/hyperv/netvsc_drv.c | 55 ++++++++++++-----------------------------
 1 file changed, 16 insertions(+), 39 deletions(-)

-- 
2.11.0

[PATCH net-next 1/2] netvsc: cleanup datapath switch

[Stephen Hemminger]

Use one routine for datapath up/down. Don't need to reopen
the rndis layer.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 38 +++++++-------------------------------
 1 file changed, 7 insertions(+), 31 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index fac44c5c8d0d..128165e49c9a 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1842,11 +1842,13 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
 	return NOTIFY_OK;
 }
 
-static int netvsc_vf_up(struct net_device *vf_netdev)
+/* VF up/down change detected, schedule to change data path */
+static int netvsc_vf_changed(struct net_device *vf_netdev)
 {
 	struct net_device_context *net_device_ctx;
 	struct netvsc_device *netvsc_dev;
 	struct net_device *ndev;
+	bool vf_is_up = netif_running(vf_netdev);
 
 	ndev = get_netvsc_byref(vf_netdev);
 	if (!ndev)
@@ -1857,34 +1859,9 @@ static int netvsc_vf_up(struct net_device *vf_netdev)
 	if (!netvsc_dev)
 		return NOTIFY_DONE;
 
-	/* Bump refcount when datapath is acvive - Why? */
-	rndis_filter_open(netvsc_dev);
-
-	/* notify the host to switch the data path. */
-	netvsc_switch_datapath(ndev, true);
-	netdev_info(ndev, "Data path switched to VF: %s\n", vf_netdev->name);
-
-	return NOTIFY_OK;
-}
-
-static int netvsc_vf_down(struct net_device *vf_netdev)
-{
-	struct net_device_context *net_device_ctx;
-	struct netvsc_device *netvsc_dev;
-	struct net_device *ndev;
-
-	ndev = get_netvsc_byref(vf_netdev);
-	if (!ndev)
-		return NOTIFY_DONE;
-
-	net_device_ctx = netdev_priv(ndev);
-	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
-	if (!netvsc_dev)
-		return NOTIFY_DONE;
-
-	netvsc_switch_datapath(ndev, false);
-	netdev_info(ndev, "Data path switched from VF: %s\n", vf_netdev->name);
-	rndis_filter_close(netvsc_dev);
+	netvsc_switch_datapath(ndev, vf_is_up);
+	netdev_info(ndev, "Data path switched %s VF: %s\n",
+		    vf_is_up ? "to" : "from", vf_netdev->name);
 
 	return NOTIFY_OK;
 }
@@ -2094,9 +2071,8 @@ static int netvsc_netdev_event(struct notifier_block *this,
 	case NETDEV_UNREGISTER:
 		return netvsc_unregister_vf(event_dev);
 	case NETDEV_UP:
-		return netvsc_vf_up(event_dev);
 	case NETDEV_DOWN:
-		return netvsc_vf_down(event_dev);
+		return netvsc_vf_changed(event_dev);
 	default:
 		return NOTIFY_DONE;
 	}
-- 
2.11.0

[PATCH net-next 2/2] netvsc: allow driver to be removed even if VF is present

[Stephen Hemminger]

If VF is attached then can still allow netvsc driver module to
be removed. Just have to make sure and do the cleanup.

Also, avoid extra rtnl round trip when calling unregister.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 128165e49c9a..97ed4bdc439f 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1834,9 +1834,6 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
 
 	netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
 
-	/* Prevent this module from being unloaded while VF is registered */
-	try_module_get(THIS_MODULE);
-
 	dev_hold(vf_netdev);
 	rcu_assign_pointer(net_device_ctx->vf_netdev, vf_netdev);
 	return NOTIFY_OK;
@@ -1880,10 +1877,11 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
 
 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
 
+	netdev_rx_handler_unregister(vf_netdev);
 	netdev_upper_dev_unlink(vf_netdev, ndev);
 	RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
 	dev_put(vf_netdev);
-	module_put(THIS_MODULE);
+
 	return NOTIFY_OK;
 }
 
@@ -1987,11 +1985,11 @@ static int netvsc_probe(struct hv_device *dev,
 
 static int netvsc_remove(struct hv_device *dev)
 {
-	struct net_device *net;
 	struct net_device_context *ndev_ctx;
+	struct net_device *vf_netdev;
+	struct net_device *net;
 
 	net = hv_get_drvdata(dev);
-
 	if (net == NULL) {
 		dev_err(&dev->device, "No net device to remove\n");
 		return 0;
@@ -2008,12 +2006,15 @@ static int netvsc_remove(struct hv_device *dev)
 	 * removed. Also blocks mtu and channel changes.
 	 */
 	rtnl_lock();
+	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
+	if (vf_netdev)
+		netvsc_unregister_vf(vf_netdev);
+
 	rndis_filter_device_remove(dev,
 				   rtnl_dereference(ndev_ctx->nvdev));
+	unregister_netdevice(net);
 	rtnl_unlock();
 
-	unregister_netdev(net);
-
 	hv_set_drvdata(dev, NULL);
 
 	free_percpu(ndev_ctx->vf_stats);
-- 
2.11.0

Re: [PATCH net-next 0/2] netvsc: transparent VF related cleanups

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Thu, 31 Aug 2017 16:16:11 -0700

> The first gets rid of unnecessary ref counting, and second
> allows removing hv_netvsc driver even if VF present.

Series applied.