On Tue, May 06, 2014 at 01:29:48AM -0700, Christoph Hellwig wrote:
> > +/*
> > + * The first XFS version we support is a v4 superblock with V2 directories.
> > + */
> > +static inline bool xfs_sb_good_v4_features(struct xfs_sb *sbp)
> > {
> > + if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
> > + return false;
> >
> > + /* check for unknown features in the fs */
> > + if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
>
> Given that sb_versionnum is a __uint16_t and XFS_SB_VERSION_OKBITS is
> 0xffff this will never evaluate to false and a sane compiler should warn
> about it. How about remove this check and XFS_SB_VERSION_OKBITS?
It gets changed later to this:
#define XFS_SB_VERSION_OKBITS \
((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
~XFS_SB_VERSION_SHAREDBIT)
So we don't ever consider the shared bit valid. IOWs, it's not
0xffff ;)
> The various has_ macros are a bit confusing to me, as some explicitly
> check for 5 superblocks, and some assume the caller handles them in
> some way, but I think this is something we can leave for later cleanups.
>
> > * For example, for a bit defined as XFS_SB_VERSION2_FUNBIT, has a macro:
> > *
> > - * SB_VERSION_HASFUNBIT(xfs_sb_t *sbp)
> > + * SB_VERSION_HASFUNBIT(struct xfs_sb *sbp)
>
> > * ((xfs_sb_version_hasmorebits(sbp) &&
> > * ((sbp)->sb_features2 & XFS_SB_VERSION2_FUNBIT)
> > */
>
> This should be updated to the lowe case convention inlines we've used
> for a long time. Or just removed as new features should go into v5
> superblocks..
I'll update it.
> Modulo these minor bits:
>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Thanks!
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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