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xen/netfront: fix waiting for xenbus state change

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commit 8edfe2e992b75aee3da9316e9697c531194c2f53 upstream.

Commit 822fb18a82aba ("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: 822fb18a82aba ("xen-netfront: wait xenbus state change when load module manually")
Cc: <stable@vger.kernel.org> #4.18
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Juergen Gross 2018-09-07 14:21:30 +02:00 committed by Greg Kroah-Hartman
parent 1cd01dba13
commit a739cb3e04
1 changed files with 10 additions and 14 deletions
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24
drivers/net/xen-netfront.c
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@ -86,8 +86,7 @@ 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;
@ -1336,11 +1335,11 @@ 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,
xenbus_read_driver_state(dev->otherend) !=
XenbusStateClosed &&
xenbus_read_driver_state(dev->otherend) !=
XenbusStateUnknown);
wait_event(module_wq,
xenbus_read_driver_state(dev->otherend) !=
XenbusStateClosed &&
xenbus_read_driver_state(dev->otherend) !=
XenbusStateUnknown);
return netdev;
exit:
@ -2025,15 +2024,14 @@ 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:
@ -2049,12 +2047,10 @@ 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;
}
@ -2162,14 +2158,14 @@ 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) ==