Subject: Re: [PATCH] 9p: disconnect channel when PCI device is removed

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Sun, 15 Apr 2012 17:57:26 +0530

Sasha Levin <[email-masked]> writes:

> When a virtio_9p pci device is being removed, we should close down any
> active channels and free up resources, we're not supposed to BUG() if there's
> still an open channel since it's a valid case when removing the PCI device.
>
> Otherwise, removing the PCI device with an open channel would cause the
> following BUG():
>
...

> diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
> index 3d43206..5af18d1 100644
> --- a/net/9p/trans_virtio.c
> +++ b/net/9p/trans_virtio.c
> @@ -615,7 +615,8 @@ static void p9_virtio_remove(struct virtio_device *vdev)
>  {
>  	struct virtio_chan *chan = vdev->priv;
>
> -	BUG_ON(chan->inuse);
> +	if (chan->inuse)
> +		p9_virtio_close(chan->client);
>  	vdev->config->del_vqs(vdev);
>
>  	mutex_lock(&virtio_9p_lock);

But an umount should have resulted in p9_virtio_close ? How are you
removing the device ? Are you removing the device with file system
mounted  ?. In that case may be we should return EBUSY ?

-aneesh