Re: [Qemu-devel] [PATCH 02/10] block: add .bdrv_co_is_allocated()

[Paolo Bonzini]

On 11/14/2011 09:10 AM, Zhi Yong Wu wrote:
> > >  No, they are necessary.  They are executed when bdrv_is_allocated_co_entry
> > >  calls qemu_coroutine_yield.
> Right, But i don't think that they are necessary.
>
> after bdrv_is_allocated_co_entry has basically completed all main
> task, it call qemu_coroutine_yield to wake up this current process; At
> that point, it is equal to the setting of data.done. Why need you
> still the three lines of codes below?

Any function _called_ by the driver's is_allocated member could call 
qemu_coroutine_yield, for example bdrv_read.

Paolo