Commit b2baed69 authored by Rusty Russell's avatar Rusty Russell Committed by David S. Miller
Browse files

virtio_net: set/cancel work on ndo_open/ndo_stop 



Michael S. Tsirkin noticed that we could run the refill work after
ndo_close, which can re-enable napi - we don't disable it until
virtnet_remove.  This is clearly wrong, so move the workqueue control
to ndo_open and ndo_stop (aka. virtnet_open and virtnet_close).

One subtle point: virtnet_probe() could simply fail if it couldn't
allocate a receive buffer, but that's less polite in virtnet_open() so
we schedule a refill as we do in the normal receive path if we run out
of memory.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 346f870b

drivers/net/virtio_net.c

+13 −4
Original line number Diff line number Diff line
@@ -440,7 +440,13 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) 
	return err;

}



/* Returns false if we couldn't fill entirely (OOM). */

/*

 * Returns false if we couldn't fill entirely (OOM).

 *

 * Normally run in the receive path, but can also be run from ndo_open

 * before we're receiving packets, or from refill_work which is

 * careful to disable receiving (using napi_disable).

 */

static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)

{

	int err;
@@ -721,6 +727,10 @@ static int virtnet_open(struct net_device *dev) 
{

	struct virtnet_info *vi = netdev_priv(dev);



	/* Make sure we have some buffers: if oom use wq. */

	if (!try_fill_recv(vi, GFP_KERNEL))

		schedule_delayed_work(&vi->refill, 0);



	virtnet_napi_enable(vi);

	return 0;

}
@@ -774,6 +784,8 @@ static int virtnet_close(struct net_device *dev) 
{

	struct virtnet_info *vi = netdev_priv(dev);



	/* Make sure refill_work doesn't re-enable napi! */

	cancel_delayed_work_sync(&vi->refill);

	napi_disable(&vi->napi);



	return 0;
@@ -1100,7 +1112,6 @@ static int virtnet_probe(struct virtio_device *vdev) 


unregister:

	unregister_netdev(dev);

	cancel_delayed_work_sync(&vi->refill);

free_vqs:

	vdev->config->del_vqs(vdev);

free_stats:
@@ -1139,9 +1150,7 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) 
	/* Stop all the virtqueues. */

	vdev->config->reset(vdev);





	unregister_netdev(vi->dev);

	cancel_delayed_work_sync(&vi->refill);



	/* Free unused buffers in both send and recv, if any. */

	free_unused_bufs(vi);

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