[azure][PATCH v1 5/9] UBUNTU: SAUCE: netvsc: add some rtnl_dereference annotations

[Marcelo Henrique Cerri]

From: stephen hemminger <stephen at networkplumber.org>

BugLink: http://bugs.launchpad.net/bugs/1708469

In a couple places RTNL is held, and the netvsc_device pointer
is acquired without annotation.

Signed-off-by: Stephen Hemminger <sthemmin at microsoft.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from net-next commit 79e8cbe7a789a0863cc6cd874872b4dd63ec5947)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/net/hyperv/netvsc.c     | 5 +++--
 drivers/net/hyperv/netvsc_drv.c | 7 ++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index de3aa1cb2611..ca7d07f8e4f1 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -44,7 +44,7 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 {
 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
 	struct hv_device *dev = net_device_ctx->device_ctx;
-	struct netvsc_device *nv_dev = net_device_ctx->nvdev;
+	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
 	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
 
 	memset(init_pkt, 0, sizeof(struct nvsp_message));
@@ -569,7 +569,8 @@ void netvsc_device_remove(struct hv_device *device)
 {
 	struct net_device *ndev = hv_get_drvdata(device);
 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
-	struct netvsc_device *net_device = net_device_ctx->nvdev;
+	struct netvsc_device *net_device
+		= rtnl_dereference(net_device_ctx->nvdev);
 	int i;
 
 	netvsc_disconnect_vsp(device);
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c506033c0c1b..0c79a73bf37a 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -77,7 +77,7 @@ static void netvsc_set_multicast_list(struct net_device *net)
 static int netvsc_open(struct net_device *net)
 {
 	struct net_device_context *ndev_ctx = netdev_priv(net);
-	struct netvsc_device *nvdev = ndev_ctx->nvdev;
+	struct netvsc_device *nvdev = rtnl_dereference(ndev_ctx->nvdev);
 	struct rndis_device *rdev;
 	int ret = 0;
 
@@ -1396,7 +1396,7 @@ static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
 			continue;	/* not a netvsc device */
 
 		net_device_ctx = netdev_priv(dev);
-		if (net_device_ctx->nvdev == NULL)
+		if (!rtnl_dereference(net_device_ctx->nvdev))
 			continue;	/* device is removed */
 
 		if (rtnl_dereference(net_device_ctx->vf_netdev) == vf_netdev)
@@ -1625,7 +1625,8 @@ static int netvsc_remove(struct hv_device *dev)
 	 * removed. Also blocks mtu and channel changes.
 	 */
 	rtnl_lock();
-	rndis_filter_device_remove(dev, ndev_ctx->nvdev);
+	rndis_filter_device_remove(dev,
+				   rtnl_dereference(ndev_ctx->nvdev));
 	rtnl_unlock();
 
 	unregister_netdev(net);
-- 
2.7.4