Commit a0be450e authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller
Browse files

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: default avatarStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 545a8e79

drivers/net/hyperv/hyperv_net.h

+0 −3
Original line number Diff line number Diff line
@@ -708,9 +708,6 @@ struct net_device_context { 
	u32 speed;

	struct netvsc_ethtool_stats eth_stats;



	/* the device is going away */

	bool start_remove;



	/* State to manage the associated VF interface. */

	struct net_device __rcu *vf_netdev;

drivers/net/hyperv/netvsc.c

+0 −4
Original line number Diff line number Diff line
@@ -605,7 +605,6 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device, 
{

	struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;

	struct net_device *ndev = hv_get_drvdata(device);

	struct net_device_context *net_device_ctx = netdev_priv(ndev);

	struct vmbus_channel *channel = device->channel;

	u16 q_idx = 0;

	int queue_sends;
@@ -639,7 +638,6 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device, 
		wake_up(&net_device->wait_drain);



	if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&

	    !net_device_ctx->start_remove &&

	    (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER ||

	     queue_sends < 1))

		netif_tx_wake_queue(netdev_get_tx_queue(ndev, q_idx));
@@ -1326,8 +1324,6 @@ int netvsc_device_add(struct hv_device *device, 
	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is

	 * populated.

	 */

	wmb();



	rcu_assign_pointer(net_device_ctx->nvdev, net_device);



	/* Connect with the NetVsp */

drivers/net/hyperv/netvsc_drv.c

+10 −24
Original line number Diff line number Diff line
@@ -760,7 +760,7 @@ static int netvsc_set_channels(struct net_device *net, 
	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 @@ static int netvsc_set_channels(struct net_device *net, 
			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 @@ static int netvsc_set_channels(struct net_device *net, 
	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 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) 
	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 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) 
	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 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) 


	rndis_filter_device_add(hdev, &device_info);



	ndevctx->start_remove = false;



	if (was_running)

		ret = netvsc_open(ndev);
@@ -1245,10 +1239,10 @@ static void netvsc_link_change(struct work_struct *w) 
	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 @@ static int netvsc_probe(struct hv_device *dev, 


	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 @@ static int netvsc_remove(struct hv_device *dev) 


	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);

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