[netdevice] Stop link block timer when device is closed

A running link block timer holds a reference to the network device and
will prevent it from being freed until the timer expires.  It is
impossible for free_netdev() to be called while the timer is still
running: the call to stop_timer() therein is therefore a no-op.

Stop the link block timer when the device is closed, to allow a
link-blocked device to be freed immediately upon unregistration of the
device.  (Since link block state is updated in response to received
packets, the state is effectively undefined for a closed device: there
is therefore no reason to leave the timer running.)

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/net/netdevice.c b/src/net/netdevice.c
index 07961bf2..91517821 100644
--- a/src/net/netdevice.c
+++ b/src/net/netdevice.c
@@ -656,7 +656,7 @@ static void free_netdev ( struct refcnt *refcnt ) {
 	struct net_device *netdev =
 		container_of ( refcnt, struct net_device, refcnt );
 
-	stop_timer ( &netdev->link_block );
+	assert ( ! timer_running ( &netdev->link_block ) );
 	netdev_tx_flush ( netdev );
 	netdev_rx_flush ( netdev );
 	clear_settings ( netdev_settings ( netdev ) );
@@ -879,6 +879,9 @@ void netdev_close ( struct net_device *netdev ) {
 	/* Close the device */
 	netdev->op->close ( netdev );
 
+	/* Stop link block timer */
+	stop_timer ( &netdev->link_block );
+
 	/* Flush TX and RX queues */
 	netdev_tx_flush ( netdev );
 	netdev_rx_flush ( netdev );