virtio-net: fix refill races during restore

[ Upstream commit 6cd4ce0099da7702f885b6fa9ebb49e3831d90b4 ]

During restoring, try_fill_recv() was called with neither napi lock nor napi
disabled. This can lead two try_fill_recv() was called in the same time. Fix
this by refilling before trying to enable napi.

Fixes 0741bcb5584f9e2390ae6261573c4de8314999f2
(virtio: net: Add freeze, restore handlers to support S4).

Cc: Amit Shah <amit.shah@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 68692af1f488229315acd9ba44bd3e1bc57b26e5..a0c05e07feeb7d8ae7d020291342d4f2c2a7ba78 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1745,16 +1745,17 @@ static int virtnet_restore(struct virtio_device *vdev)
        if (err)
                return err;
 
-       if (netif_running(vi->dev))
+       if (netif_running(vi->dev)) {
+               for (i = 0; i < vi->curr_queue_pairs; i++)
+                       if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+                               schedule_delayed_work(&vi->refill, 0);
+
                for (i = 0; i < vi->max_queue_pairs; i++)
                        virtnet_napi_enable(&vi->rq[i]);
+       }
 
        netif_device_attach(vi->dev);
 
-       for (i = 0; i < vi->curr_queue_pairs; i++)
-               if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
-                       schedule_delayed_work(&vi->refill, 0);
-
        mutex_lock(&vi->config_lock);
        vi->config_enable = true;
        mutex_unlock(&vi->config_lock);