On Wed, 06/24 10:47, Fam Zheng wrote: > On Tue, 06/16 17:07, Stefan Hajnoczi wrote: > > On Tue, Jun 02, 2015 at 11:21:51AM +0800, Fam Zheng wrote: > > > +/** > > > + * bdrv_lock: > > > + * > > > + * Begin a temporary exclusive accessing by locking the BDS. > > > + */ > > > +void bdrv_lock(BlockDriverState *bs); > > > + > > > +/** > > > + * bdrv_unlock: > > > + * > > > + * End a exclusive accessing. > > > + */ > > > +void bdrv_unlock(BlockDriverState *bs); > > > > This documentation is missing important points: > > > > 1. Does AioContext need to be held by the caller? (Yes) > > Yes. > > > > > 2. Is this about thread safety? (No, it's about exclusive access to a > > BDS *within* the AioContext.) > > As it has to quiesce iothreads as well (for now it's even more urgent than
s/iothreads/ioeventfd/ > exclusive access within the same AioContext), I'd rather take it as yes. > > Paolo, please correct me. > > BTW, is there any semantics in here that we can use for multiqueue block > layer? > > Fam > >