Re: [PATCH v4 07/10] qcow2-refcount: check_refcounts_l2(): check reserved bits

[Vladimir Sementsov-Ogievskiy]

14.09.2021 20:15, Hanna Reitz wrote:
> On 14.09.21 14:24, Vladimir Sementsov-Ogievskiy wrote:
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > Reviewed-by: Eric Blake <eblake@redhat.com>
> > Tested-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> > Reviewed-by: Hanna Reitz <hreitz@redhat.com>
> > ---
> >   block/qcow2.h          |  1 +
> >   block/qcow2-refcount.c | 12 +++++++++++-
> >   2 files changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/block/qcow2.h b/block/qcow2.h
> > index c0e1e83796..b8b1093b61 100644
> > --- a/block/qcow2.h
> > +++ b/block/qcow2.h
> > @@ -587,6 +587,7 @@ typedef enum QCow2MetadataOverlap {
> >   #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
> >   #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
> > +#define L2E_STD_RESERVED_MASK 0x3f000000000001feULL
> >   #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
> > diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> > index 9a5ae3cac4..5d57e677bc 100644
> > --- a/block/qcow2-refcount.c
> > +++ b/block/qcow2-refcount.c
> > @@ -1682,8 +1682,18 @@ static int check_refcounts_l2(BlockDriverState *bs, 
> > BdrvCheckResult *res,
> >           int csize;
> >           l2_entry = get_l2_entry(s, l2_table, i);
> >           l2_bitmap = get_l2_bitmap(s, l2_table, i);
> > +        QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);

Oh :(

> Hm, with l2_bitmap being declared next to l2_entry, this is now the patch that 
> adds a declaration after a statement here.
>
> (The possible resolutions seem to be the same, either move the declaration up 
> to the function’s root block, or move l2_entry and l2_bitmap’s declarations 
> here...)
>
> (I don’t think we need a v5 for this, it should be fine if you tell me which 
> way you prefer.)

I'd keep type here:

QCow2ClusterType type;

l2_entry = ...
l2_bitmap = ...
type = qcow2_get_cluster_type(bs, l2_entry);


--
Best regards,
Vladimir