From 9b9cd8024a2882e896c65222aa421d461354e3f2 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 4 Jul 2013 11:22:57 +0930 Subject: [PATCH] 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 Cc: Rusty Russell Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: Rusty Russell --- drivers/net/virtio_net.c | 5 +---- 1 file changed, 1 insertion(+), 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; -- 2.39.5