From: Ake Koomsin Date: Wed, 17 Oct 2018 10:44:12 +0000 (+0900) Subject: virtio_net: avoid using netif_tx_disable() for serializing tx routine X-Git-Tag: v4.14.79~15 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=574af67123c3da1e094813d122baa6cd37ccc4af;p=users%2Fjedix%2Flinux-maple.git virtio_net: avoid using netif_tx_disable() for serializing tx routine [ 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 Acked-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 910c46b477699..f528e9ac3413b 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1872,8 +1872,9 @@ 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)) { @@ -1909,7 +1910,9 @@ 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; }