virtio_net: avoid using netif_tx_disable() for serializing tx routine

[ Upstream commit 05c998b738 ]

Commit 713a98d90c ("virtio-net: serialize tx routine during reset")
introduces netif_tx_disable() after netif_device_detach() in order to
avoid use-after-free of tx queues. However, there are two issues.

1) Its operation is redundant with netif_device_detach() in case the
   interface is running.
2) In case of the interface is not running before suspending and
   resuming, the tx does not get resumed by netif_device_attach().
   This results in losing network connectivity.

It is better to use netif_tx_lock_bh()/netif_tx_unlock_bh() instead for
serializing tx routine during reset. This also preserves the symmetry
of netif_device_detach() and netif_device_attach().

Fixes commit 713a98d90c ("virtio-net: serialize tx routine during reset")
Signed-off-by: Ake Koomsin <ake@igel.co.jp>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ake Koomsin
2018-11-04 14:51:53 +01:00
committed by Greg Kroah-Hartman
parent c75d697c81
commit e30293d0a0
+4 -1
View File
@@ -2162,8 +2162,9 @@ static void virtnet_freeze_down(struct virtio_device *vdev)
/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);
netif_tx_lock_bh(vi->dev);
netif_device_detach(vi->dev);
netif_tx_disable(vi->dev);
netif_tx_unlock_bh(vi->dev);
cancel_delayed_work_sync(&vi->refill);
if (netif_running(vi->dev)) {
@@ -2199,7 +2200,9 @@ static int virtnet_restore_up(struct virtio_device *vdev)
}
}
netif_tx_lock_bh(vi->dev);
netif_device_attach(vi->dev);
netif_tx_unlock_bh(vi->dev);
return err;
}