From: Jason Wang <jasowang@redhat.com>
Date: Mon, 30 Dec 2013 03:34:40 +0000 (+0800)
Subject: virtio-net: fix refill races during restore
X-Git-Tag: upstream/snapshot3+hdmi~3699^2~18
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6cd4ce0099da7702f885b6fa9ebb49e3831d90b4;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

virtio-net: fix refill races during restore

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>
---

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d208f86..5d77644 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1797,16 +1797,17 @@ 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);