Re: [PATCH 2/2] virtio: fix double free_irq

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 23, 2009 at 02:10:31PM +0930, Rusty Russell wrote:
> On Wed, 22 Jul 2009 01:29:25 am Michael S. Tsirkin wrote:
> > -	if (info->vector != VIRTIO_MSI_NO_VECTOR)
> > +	if (info->vector != VIRTIO_MSI_NO_VECTOR) {
> >  		free_irq(vp_dev->msix_entries[info->vector].vector, vq);
> > +		--vp_dev->msix_used_vectors;
> > +	}
> >
> 
> This only works because the only current caller of vp_del_vq is vp_del_vqs, so 
> msix_used_vectors will be 0 after all the queues have been freed.
> 
> Make up your mind.  Either find_vq allocates and del_vq frees, or it's find_vqs 
> and del_vqs.  I suggest the former, and setting the value VIRTIO_MSI_NO_VECTOR  
> to indicate it's already freed.

Hmm, there's nowhere to set this value: del_vq does kfree on info.
But I think I see a solution. Cleaned up patch RSN.

> I think with some cleanups, that loop in vp_free_vectors might go away, too.

Hmm, I don't see how, yet.
It's there to free the common vectors: config and shared vq vector.

> Rusty.
> 
> 
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