Re: [Qemu-devel] [Qemu-block] [PATCH v5 10/12] block: Introduce BlockDriver.bdrv_drain callback

[Jeff Cody]

On Wed, Oct 21, 2015 at 10:06:47AM +0800, Fam Zheng wrote:
> Drivers can have internal request sources that generate IO, like the
> need_check_timer in QED. Since we want quiesced periods that contain
> nested event loops in block layer, we need to have a way to disable such
> event sources.
> 
> Block drivers must implement the "bdrv_drain" callback if it has any
> internal sources that can generate I/O activity, like a timer or a
> worker thread (even in a library) that can schedule QEMUBH in an
> asynchronous callback.
> 
> Update the comments of bdrv_drain and bdrv_drained_begin accordingly.
> 
> Signed-off-by: Fam Zheng <address@hidden>



Reviewed-by: Jeff Cody <address@hidden>