On Fri, Apr 12, 2013 at 12:27 PM, Paolo Bonzini <pbonz...@redhat.com> wrote: > Il 12/04/2013 12:04, Kevin Wolf ha scritto: >> Or actually, if you want to avoid .bdrv_drain for now, the patch that I >> started when I thought a bit about this, had a default .bdrv_drain >> implementation that just forwarded the request to bs->file if it wasn't >> implemented by a block driver. For the QED case, this would work. > > It's similar to bdrv_co_flush. Drain bs first, then bs->backing_hd > (this is not needed in bdrv_co_flush), then bs->file, then the driver > can do it on other files.
Thanks for explaining Kevin. I didn't check whether bdrv_states included all BlockDriverStates. The simplest solution is to put all BlockDriverStates on a global list. A .bdrv_drain() interface is more flexible but I don't see a need for it yet. Stefan
