4.9-stable review patch. If anyone has any objections, please let me know.
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From: Juergen Gross jgross@suse.com
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
--- drivers/net/xen-netfront.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-)
--- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -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; @@ -1350,11 +1349,11 @@ static struct net_device *xennet_create_ 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: @@ -2039,15 +2038,14 @@ static void netback_changed(struct xenbu
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: @@ -2063,12 +2061,10 @@ static void netback_changed(struct xenbu 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; } @@ -2176,14 +2172,14 @@ static int xennet_remove(struct xenbus_d
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) ==