Re: [Qemu-block] [PATCH v10 01/16] block: Pause all jobs during bdrv_reopen_multiple()

[Kevin Wolf]

Am 10.10.2016 um 18:41 hat Paolo Bonzini geschrieben:
> On 10/10/2016 17:37, Kevin Wolf wrote:
> > > +    while ((job = block_job_next(job))) {
> > > +        AioContext *aio_context = blk_get_aio_context(job->blk);
> > > +
> > > +        aio_context_acquire(aio_context);
> > > +        block_job_pause(job);
> > > +        aio_context_release(aio_context);
> > > +    }
> > > +
> > >      bdrv_drain_all();
> >
> > We already have a bdrv_drain_all() here, which does the same thing (and
> > more) internally, except that it resumes all jobs before it returns.
> > Maybe what we should do is split bdrv_drain_all() in a begin/end pair,
> > too.
> 
> Hey, haven't I just suggested the same? :)  I swear I hadn't read this
> before.
> 
> > The other point I'm wondering now is whether bdrv_drain_all() should
> > have the aio_disable/enable_external() pair that bdrv_drain() has.
> 
> bdrv_drain_all need not have it, but its start/end replacement should.

Doesn't need it because it holds the AioContext lock?

Kevin