On Tue, Apr 5, 2011 at 5:49 AM, Takuma Umeya <tumeya@xxxxxxxxxx> wrote:
> When virtio device is removed, dev_index does not get decremented.
> The next device hotplug event results in consuming the next pci to
> the one that is suppose to be available.
>
> Signed-off-by: Takuma Umeya <tumeya@xxxxxxxxxx>
>
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index efb35aa..67fe71d 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -216,6 +216,7 @@ EXPORT_SYMBOL_GPL(register_virtio_device);
> void unregister_virtio_device(struct virtio_device *dev)
> {
> device_unregister(&dev->dev);
> + dev_index--;
I don't think there is any guarantee that virtio devices are
added/removed in first-in-last-out order.
That means I could add a virtio-net device (index 0) followed by a
virtio-blk device (index 1). Now I remove the virtio-net device
(index 0) which causes me to decrement dev_index and hand index 1 out
again to the next device. This leaves us with virtio-blk (index 1)
and the new device with index 1, which is not unique.
Perhaps I missed a constraint which prevents this from occurring?
Stefan
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