Re: [Qemu-devel] [PATCH 3/5] dma-helpers: rewrite completion/cancellation

[Paolo Bonzini]

On 09/09/2011 03:34 PM, Kevin Wolf wrote:
> So the release that we avoid is the release in the callback that may or
> may not be called indirectly by bdrv_aio_cancel. We always call
> dma_complete at the end of dma_aio_cancel so that it will be properly freed.
>
> > In fact it may be worse than just the qemu_aio_release: if the driver is
> > waiting for the request to complete, it will write over the bounce
> > buffer after dma_bdrv_unmap has been called.
>
> How that? dma_bdrv_unmap is called only afterwards, isn't it?

I had missed your point completely. :)  Yes, the above should work.

Paolo