4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ake Koomsin ake@igel.co.jp
[ Upstream commit 05c998b738fdd3e5d6a257bcacc8f34b6284d795 ]
Commit 713a98d90c5e ("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 713a98d90c5e ("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 --- drivers/net/virtio_net.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1872,8 +1872,9 @@ static void virtnet_freeze_down(struct v /* 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)) { @@ -1909,7 +1910,9 @@ static int virtnet_restore_up(struct vir } }
+ netif_tx_lock_bh(vi->dev); netif_device_attach(vi->dev); + netif_tx_unlock_bh(vi->dev); return err; }