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: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rusty Russell 2011-12-29 00:42:38 +00:00 committed by David S. Miller
parent 346f870b8a
commit b2baed69e6

View File

@ -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);