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Commit 8edfe2e9 authored by Juergen Gross's avatar Juergen Gross Committed by David S. Miller
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xen/netfront: fix waiting for xenbus state change 



Commit 822fb18a ("xen-netfront: wait xenbus state change when load
module manually") added a new wait queue to wait on for a state change
when the module is loaded manually. Unfortunately there is no wakeup
anywhere to stop that waiting.

Instead of introducing a new wait queue rename the existing
module_unload_q to module_wq and use it for both purposes (loading and
unloading).

As any state change of the backend might be intended to stop waiting
do the wake_up_all() in any case when netback_changed() is called.

Fixes: 822fb18a ("xen-netfront: wait xenbus state change when load module manually")
Cc: <stable@vger.kernel.org> #4.18
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f74dd480

drivers/net/xen-netfront.c

+10 −14
Original line number Diff line number Diff line
@@ -87,8 +87,7 @@ struct netfront_cb { 
/* IRQ name is queue name with "-tx" or "-rx" appended */

#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)



static DECLARE_WAIT_QUEUE_HEAD(module_load_q);

static DECLARE_WAIT_QUEUE_HEAD(module_unload_q);

static DECLARE_WAIT_QUEUE_HEAD(module_wq);



struct netfront_stats {

	u64			packets;
@@ -1332,7 +1331,7 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) 
	netif_carrier_off(netdev);



	xenbus_switch_state(dev, XenbusStateInitialising);

	wait_event(module_load_q,

	wait_event(module_wq,

		   xenbus_read_driver_state(dev->otherend) !=

		   XenbusStateClosed &&

		   xenbus_read_driver_state(dev->otherend) !=
@@ -2010,15 +2009,14 @@ static void netback_changed(struct xenbus_device *dev, 


	dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));



	wake_up_all(&module_wq);



	switch (backend_state) {

	case XenbusStateInitialising:

	case XenbusStateInitialised:

	case XenbusStateReconfiguring:

	case XenbusStateReconfigured:

		break;



	case XenbusStateUnknown:

		wake_up_all(&module_unload_q);

		break;



	case XenbusStateInitWait:
@@ -2034,12 +2032,10 @@ static void netback_changed(struct xenbus_device *dev, 
		break;



	case XenbusStateClosed:

		wake_up_all(&module_unload_q);

		if (dev->state == XenbusStateClosed)

			break;

		/* Missed the backend's CLOSING state -- fallthrough */

	case XenbusStateClosing:

		wake_up_all(&module_unload_q);

		xenbus_frontend_closed(dev);

		break;

	}
@@ -2147,14 +2143,14 @@ static int xennet_remove(struct xenbus_device *dev) 


	if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {

		xenbus_switch_state(dev, XenbusStateClosing);

		wait_event(module_unload_q,

		wait_event(module_wq,

			   xenbus_read_driver_state(dev->otherend) ==

			   XenbusStateClosing ||

			   xenbus_read_driver_state(dev->otherend) ==

			   XenbusStateUnknown);



		xenbus_switch_state(dev, XenbusStateClosed);

		wait_event(module_unload_q,

		wait_event(module_wq,

			   xenbus_read_driver_state(dev->otherend) ==

			   XenbusStateClosed ||

			   xenbus_read_driver_state(dev->otherend) ==