Il 18/09/2012 11:40, Kevin Wolf ha scritto: >>> >> Note that after completing the refactoring, we'll only have one combined >>> >> bdrv_close/delete function and so there won't be BlockDriverStates >>> >> that are closed. In this case, I think it's quite obvious that not >>> >> closing >>> >> the filters wouldn't make any sense. >> > >> > Does that mean that any I/O throttling must be applied again on every >> > medium change? That would be a behavioral change. > Hm, I guess so, at least on the lowest level. The only thing I know for > certain is that maintaining compatibility for the old commands will be > fun, but if possible at all we shouldn't let that compromise our design.
Yeah, originally we had the idea of a "proxy" driver where you could stack all your persistent filters. The proxy driver would be needed of course for removable media, but it could also subsume things like bdrv_swap and bdrv_append. Paolo
