Re: [Qemu-devel] [PATCH v2 4/9] block: vhdx - log support struct and defines

[Jeff Cody <jcody@redhat.com>]

On Wed, Aug 07, 2013 at 05:22:45PM +0200, Kevin Wolf wrote:
> Am 01.08.2013 um 05:23 hat Jeff Cody geschrieben:
> > This adds some magic number defines, and internal structure
> > definitions for VHDX log replay support.
> > 
> > Signed-off-by: Jeff Cody <jcody@redhat.com>
> > ---
> >  block/vhdx.h | 21 ++++++++++++++++++++-
> >  1 file changed, 20 insertions(+), 1 deletion(-)
> > 
> > diff --git a/block/vhdx.h b/block/vhdx.h
> > index c8d8593..2db6615 100644
> > --- a/block/vhdx.h
> > +++ b/block/vhdx.h
> > @@ -151,7 +151,10 @@ typedef struct QEMU_PACKED VHDXRegionTableEntry {
> >  
> >  
> >  /* ---- LOG ENTRY STRUCTURES ---- */
> > +#define VHDX_LOG_MIN_SIZE (1024*1024)
> 
> There should be spaces around the operator.
> 

OK.  Checkpatch.pl missed this, I guess it doesn't check macros?

> Also, VHDX_LOG_ENTRY_MIN_SIZE? I thought at first that this was the
> minimum size of the whole log (or does that happen to be the same and I
> just missed it in the spec?)
>

This is indeed the minimum size for the entire log - once you get to
patch 7, you'll see it used.  But an interesting thing about this, is
the original 0.95 spec said that 1MB was also the minimum log *entry*
size as well.  But that was incorrect, and the 1.00 spec notes that a
log entry size min is 4KB (same as the log sector size).

Jeff