On Sat, Aug 22, 2020 at 08:12:18AM +0100, Christoph Hellwig wrote:
> > diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
> > index acb9b737fe6b..48a64fa49f91 100644
> > --- a/fs/xfs/xfs_ondisk.h
> > +++ b/fs/xfs/xfs_ondisk.h
> > @@ -15,6 +15,18 @@
> > "XFS: offsetof(" #structname ", " #member ") is wrong, " \
> > "expected " #off)
> >
> > +#define XFS_CHECK_VALUE(value, expected) \
> > + BUILD_BUG_ON_MSG((value) != (expected), \
> > + "XFS: value of " #value " is wrong, expected " #expected)
> > +
> > +static inline void __init
> > +xfs_check_limits(void)
> > +{
> > + /* make sure timestamp limits are correct */
> > + XFS_CHECK_VALUE(XFS_INO_TIME_MIN, -2147483648LL);
> > + XFS_CHECK_VALUE(XFS_INO_TIME_MAX, 2147483647LL);
>
> I have to admit I don't get why you'd define a constant and then
> check that it has the value you defined it to. Seems a little cargo
> cult.
Testing the timestamp min/max is more important for bigtime, since the
supported ranges are not conveniently aligned with S32_MIN/MAX. But it
felt strange to build-check bigtime without doing the same for !bigtime,
so I included it here for completeness.
--D
