[PATCH 1/2] virtio_net: fix for stuck when change rx ring size with dev down
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2022-08-11 08:03:06
Also in:
virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
When dev is set to DOWN state, napi has been disabled, if we modify the ring size at this time, we should not call napi_disable() again, which will cause stuck. And all operations are under the protection of rtnl_lock, so there is no need to consider concurrency issues. Reported-by: Kangjie Xu <redacted> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio_net.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 816c613c22f7..17687eb3f0bd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -1892,11 +1892,13 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) static int virtnet_rx_resize(struct virtnet_info *vi, struct receive_queue *rq, u32 ring_num) { + bool running = netif_running(vi->dev); int err, qindex; qindex = rq - vi->rq; - napi_disable(&rq->napi); + if (running) + napi_disable(&rq->napi); err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf); if (err)
@@ -1905,7 +1907,8 @@ static int virtnet_rx_resize(struct virtnet_info *vi, if (!try_fill_recv(vi, rq, GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); - virtnet_napi_enable(rq->vq, &rq->napi); + if (running) + virtnet_napi_enable(rq->vq, &rq->napi); return err; }
--
2.31.0