netvsc: uses RCU instead of removal flag
It is cleaner to use RCU protected pointer (nvdev_ctx->nvdev)
to indicate device is in removed state, rather than having a separate
boolean flag. By using the pointer the context can be checked
by static checkers and dynamic lockdep.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index d8a70d0..eb7ae79 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -760,7 +760,7 @@
if (count > net->num_tx_queues || count > net->num_rx_queues)
return -EINVAL;
- if (net_device_ctx->start_remove || !nvdev || nvdev->destroy)
+ if (!nvdev || nvdev->destroy)
return -ENODEV;
if (nvdev->nvsp_version < NVSP_PROTOCOL_VERSION_5)
@@ -776,7 +776,6 @@
return ret;
}
- net_device_ctx->start_remove = true;
rndis_filter_device_remove(dev, nvdev);
ret = netvsc_set_queues(net, dev, count);
@@ -785,8 +784,6 @@
else
netvsc_set_queues(net, dev, nvdev->num_chn);
- net_device_ctx->start_remove = false;
-
if (was_running)
ret = netvsc_open(net);
@@ -860,7 +857,7 @@
bool was_running;
int ret;
- if (ndevctx->start_remove || !nvdev || nvdev->destroy)
+ if (!nvdev || nvdev->destroy)
return -ENODEV;
was_running = netif_running(ndev);
@@ -875,7 +872,6 @@
device_info.num_chn = nvdev->num_chn;
device_info.max_num_vrss_chns = nvdev->num_chn;
- ndevctx->start_remove = true;
rndis_filter_device_remove(hdev, nvdev);
/* 'nvdev' has been freed in rndis_filter_device_remove() ->
@@ -888,8 +884,6 @@
rndis_filter_device_add(hdev, &device_info);
- ndevctx->start_remove = false;
-
if (was_running)
ret = netvsc_open(ndev);
@@ -1245,10 +1239,10 @@
unsigned long flags, next_reconfig, delay;
rtnl_lock();
- if (ndev_ctx->start_remove)
+ net_device = rtnl_dereference(ndev_ctx->nvdev);
+ if (!net_device)
goto out_unlock;
- net_device = rtnl_dereference(ndev_ctx->nvdev);
rdev = net_device->extension;
next_reconfig = ndev_ctx->last_reconfig + LINKCHANGE_INT;
@@ -1509,8 +1503,6 @@
hv_set_drvdata(dev, net);
- net_device_ctx->start_remove = false;
-
INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
INIT_WORK(&net_device_ctx->work, do_set_multicast);
@@ -1579,26 +1571,20 @@
ndev_ctx = netdev_priv(net);
- /* Avoid racing with netvsc_change_mtu()/netvsc_set_channels()
- * removing the device.
- */
- rtnl_lock();
- ndev_ctx->start_remove = true;
- rtnl_unlock();
+ netif_device_detach(net);
cancel_delayed_work_sync(&ndev_ctx->dwork);
cancel_work_sync(&ndev_ctx->work);
- /* Stop outbound asap */
- netif_tx_disable(net);
-
- unregister_netdev(net);
-
/*
* Call to the vsc driver to let it know that the device is being
- * removed
+ * removed. Also blocks mtu and channel changes.
*/
+ rtnl_lock();
rndis_filter_device_remove(dev, ndev_ctx->nvdev);
+ rtnl_unlock();
+
+ unregister_netdev(net);
hv_set_drvdata(dev, NULL);