Re: [Qemu-devel] [PATCH v13 4/6] qapi: introduce PreallocMode and a new PreallocMode full.

[Hu Tao]

On Tue, Sep 02, 2014 at 03:51:23PM -0600, Eric Blake wrote:
> On 08/29/2014 02:33 AM, Hu Tao wrote:
> > This patch prepares for the subsequent patches.
> > 
> > Signed-off-by: Hu Tao <address@hidden>
> > ---
> >  block/qcow2.c              | 23 +++++++++++++++--------
> >  qapi/block-core.json       | 16 ++++++++++++++++
> >  tests/qemu-iotests/049.out |  2 +-
> >  3 files changed, 32 insertions(+), 9 deletions(-)
> > 
> 
> > @@ -1958,6 +1958,13 @@ static int qcow2_create(const char *filename, 
> > QemuOpts *opts, Error **errp)
> >          flags |= BLOCK_FLAG_LAZY_REFCOUNTS;
> >      }
> >  
> > +    if (prealloc && prealloc != PREALLOC_MODE_METADATA) {

This one reads as 'support PREALLOC_MODE_METADATA' only,

> 
> I find it a bit awkward that you are checking for PREALLOC_MODE_OFF
> implicitly ('prealloc &&') vs. checking for prealloc mode METADATA
> explicitly.  Since there are only three modes, would it be any simpler
> to just have written:
> 
> if (prealloc == PREALLOC_MODE_FULL) {

and this one reads as 'does't support PREALLOC_MODE_FULL'.  Althrough
they are the same, but I'd prefer the former one. Anyway, the check is
removed in patch 6.

Regards,
Hu

> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>