[022/105] staging: hv: Fix GARP not sent after Quick Migration

Greg KH
2011-04-12T14:56:57Z

From: Haiyang Zhang <haiyangz@microsoft.com>

commit c996edcf1c451b81740abbcca5257ed7e353fcc6 upstream.

After Quick Migration, the network is not immediately operational in the
current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, I added
another netif_notify_peers() into a scheduled work, otherwise GARP packet will
not be sent after quick migration, and cause network disconnection.

Thanks to Mike Surcouf <mike@surcouf.co.uk> for reporting the bug and
testing the patch.

Reported-by: Mike Surcouf <mike@surcouf.co.uk>
Tested-by: Mike Surcouf <mike@surcouf.co.uk>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/staging/hv/netvsc_drv.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

--- a/drivers/staging/hv/netvsc_drv.c
+++ b/drivers/staging/hv/netvsc_drv.c
@@ -46,6 +46,7 @@ struct net_device_context {
/* point back to our device context */
struct vm_device *device_ctx;
unsigned long avail;
+ struct work_struct work;
};

struct netvsc_driver_context {
@@ -225,6 +226,7 @@ static void netvsc_linkstatus_callback(s
unsigned int status)
{
struct vm_device *device_ctx = to_vm_device(device_obj);
+ struct net_device_context *ndev_ctx;
struct net_device *net = dev_get_drvdata(&device_ctx->device);

if (!net) {
@@ -237,6 +239,8 @@ static void netvsc_linkstatus_callback(s
netif_carrier_on(net);
netif_wake_queue(net);
netif_notify_peers(net);
+ ndev_ctx = netdev_priv(net);
+ schedule_work(&ndev_ctx->work);
} else {
netif_carrier_off(net);
netif_stop_queue(net);
@@ -336,6 +340,25 @@ static const struct net_device_ops devic
.ndo_set_mac_address = eth_mac_addr,
};

+/*
+ * Send GARP packet to network peers after migrations.
+ * After Quick Migration, the network is not immediately operational in the
+ * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
+ * another netif_notify_peers() into a scheduled work, otherwise GARP packet
+ * will not be sent after quick migration, and cause network disconnection.
+ */
+static void netvsc_send_garp(struct work_struct *w)
+{
+ struct net_device_context *ndev_ctx;
+ struct net_device *net;
+
+ msleep(20);
+ ndev_ctx = container_of(w, struct net_device_context, work);
+ net = dev_get_drvdata(&ndev_ctx->device_ctx->device);
+ netif_notify_peers(net);
+}
+
+
static int netvsc_probe(struct device *device)
{
struct driver_context *driver_ctx =
@@ -364,6 +387,7 @@ static int netvsc_probe(struct device *d
net_device_ctx->device_ctx = device_ctx;
net_device_ctx->avail = ring_size;
dev_set_drvdata(device, net);
+ INIT_WORK(&net_device_ctx->work, netvsc_send_garp);

/* Notify the netvsc driver of the new device */
ret = net_drv_obj->base.OnDeviceAdd(device_obj, &device_info);