4.17-stable review patch. If anyone has any objections, please let me know.
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From: Xiao Liang xiliang@redhat.com
[ Upstream commit 822fb18a82abaf4ee7058793d95d340f5dab7bfc ]
When loading module manually, after call xenbus_switch_state to initializes the state of the netfront device, the driver state did not change so fast that may lead no dev created in latest kernel. This patch adds wait to make sure xenbus knows the driver is not in closed/unknown state.
Current state: [vm]# ethtool eth0 Settings for eth0: Link detected: yes [vm]# modprobe -r xen_netfront [vm]# modprobe xen_netfront [vm]# ethtool eth0 Settings for eth0: Cannot get device settings: No such device Cannot get wake-on-lan settings: No such device Cannot get message level: No such device Cannot get link status: No such device No data available
With the patch installed. [vm]# ethtool eth0 Settings for eth0: Link detected: yes [vm]# modprobe -r xen_netfront [vm]# modprobe xen_netfront [vm]# ethtool eth0 Settings for eth0: Link detected: yes
Signed-off-by: Xiao Liang xiliang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/xen-netfront.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -87,6 +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);
struct netfront_stats { @@ -1330,6 +1331,11 @@ 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); return netdev;
exit: