Re: [Qemu-devel] [PATCH v2 2/9] block: vhdx - add header update capability.

[Jeff Cody <jcody@redhat.com>]

On Mon, Aug 05, 2013 at 05:05:36PM +0200, Kevin Wolf wrote:
> Am 01.08.2013 um 05:23 hat Jeff Cody geschrieben:
> > This adds the ability to update the headers in a VHDX image, including
> > generating a new MS-compatible GUID.
> > 
> > As VHDX depends on uuid.h, VHDX is now a configurable build option.  If
> > VHDX support is enabled, that will also enable uuid as well.  The
> > default is to have VHDX enabled.
> > 
> > To enable/disable VHDX:  --enable-vhdx, --disable-vhdx
> > 
> > Signed-off-by: Jeff Cody <jcody@redhat.com>
> 
> I knew I'd forget to mention something I had seen...
> 
> > +    /* overwrite the actual VHDXHeader portion */
> > +    memcpy(buffer, inactive_header, sizeof(VHDXHeader));
> > +    inactive_header->checksum = vhdx_update_checksum(buffer,
> > +                                                     VHDX_HEADER_SIZE, 4);
> 
> This I would prefer as offsetof(VHDXHeader, checksum) instead of a magic
> number 4.

Who doesn't like a little bit of magic? :)  OK, I'll use offsetof()
(I'll also look through the rest of my patches for similar occurrences
as well).

Jeff