Re: [Qemu-block] [PATCH 11/22] qcow2-bitmap: add qcow2_store_persistent_bitmaps()

[Vladimir Sementsov-Ogievskiy]

On 07.10.2016 22:24, Max Reitz wrote:
> On 30.09.2016 12:53, Vladimir Sementsov-Ogievskiy wrote:
> > Realize block bitmap stroing interface, to allow qcow2 images store

[snip]

> > +        uint64_t end = MIN(bm_size, sector + dsc);
> > +        uint64_t write_size =
> > +            bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector);
> > +
> > +        int64_t off = qcow2_alloc_clusters(bs, cl_size);
> > +        if (off < 0) {
> > +            ret = off;
> > +            goto finish;
> > +        }
> > +        bitmap_table[cluster] = off;
> > +
> > +        bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end);
> s/end/end - sector/?

o_0 terrible mistake, thank you.

> > +        if (write_size < cl_size) {
> > +            memset(buf + write_size, 0, cl_size - write_size);
> > +        }
> > +
> I guess there should be a metadata overlap check here.

What is the general rule of checking it? Should I check it before all my 
extension related writes?


--
Best regards,
Vladimir