Re: [Qemu-devel] [PATCH v4 18/20] vpc: Switch to .bdrv_co_block_status()

[Eric Blake]

On 11/30/2017 06:22 AM, Vladimir Sementsov-Ogievskiy wrote:
> 12.10.2017 21:59, Eric Blake wrote:
> > We are gradually moving away from sector-based interfaces, towards
> > byte-based.  Update the vpc driver accordingly.  Drop the now-unused
> > get_sector_offset().
> >
> > Signed-off-by: Eric Blake <address@hidden>
> >
> > ---

> > -    offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 
> > false, NULL);
> > -    start = offset;
> > -    allocated = (offset != -1);
> > +    image_offset = get_image_offset(bs, offset, false, NULL);
> > +    start = image_offset & BDRV_BLOCK_OFFSET_MASK;
>
> why do you do so? round down to sector boundary? does it mean,
> that *map will corresponds not to offset, but to some previous byte?

Ouch, leftovers from before the interface change in v4.  Will fix.


> >           }
> > -        offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 
> > false,
> > -                                  NULL);
> > +        image_offset = get_image_offset(bs, offset, false, NULL);
> >       } while (offset == -1);
>
> image_offset here?

Yes.  (Does it show that for non-typical formats, I only compile-tested 
instead of actually running iotests on the format?)

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org