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authorJason Wang <jasowang@redhat.com>2013-07-04 11:22:57 +0930
committerRusty Russell <rusty@rustcorp.com.au>2013-07-04 11:25:06 +0930
commit9b9cd8024a2882e896c65222aa421d461354e3f2 (patch)
tree16d4ce44ff3f326828e32c2b7c2073f12f37d9b1 /drivers/net/virtio_net.c
parent0d69a65e97fc8090ee83c8639137b4b5c8ece237 (diff)
downloadlinux-9b9cd8024a2882e896c65222aa421d461354e3f2.tar.gz
virtio-net: fix the race between channels setting and refill
Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues
which are being used) tries to refill on demand when changing the number of
channels by call try_refill_recv() directly, this may race:

- the refill work who may do the refill in the same time
- the try_refill_recv() called in bh since napi was not disabled

Which may led guest complain during setting channels:

virtio_net virtio0: input.1:id 0 is not a head!

Solve this issue by scheduling a refill work which can guarantee the
serialization of refill.

Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 655bb25eed2b..6ddd77ece5d5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -900,7 +900,6 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 	struct scatterlist sg;
 	struct virtio_net_ctrl_mq s;
 	struct net_device *dev = vi->dev;
-	int i;
 
 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
 		return 0;
@@ -914,10 +913,8 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 			 queue_pairs);
 		return -EINVAL;
 	} else {
-		for (i = vi->curr_queue_pairs; i < queue_pairs; i++)
-			if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
-				schedule_delayed_work(&vi->refill, 0);
 		vi->curr_queue_pairs = queue_pairs;
+		schedule_delayed_work(&vi->refill, 0);
 	}
 
 	return 0;