Re: [PATCH v3 02/11] xfs: reserve v5 superblock read-only compat. feature bit for finobt

Dave Chinner
2014-02-11T06:08:11Z

On Tue, Feb 04, 2014 at 12:49:33PM -0500, Brian Foster wrote:
> Reserve a v5 read-only compatibility feature bit for the finobt and
> create the xfs_sb_version_hasfinobt() helper to determine whether
> an fs has the feature enabled.
>
> The finobt does not change existing on-disk structures, but must
> remain consistent with the ialloc btree. Modifications from older
> kernels would violate that constrant. Therefore, we restrict older
> kernels to read-only mounts of finobt-enabled filesystems.
>
> Note that this does not yet enable the ability to rw mount a finobt
> fs (by setting the feature bit in the XFS_SB_FEAT_RO_COMPAT_ALL
> mask).
>
> Signed-off-by: Brian Foster <bfoster@redhat.com>

Looks good.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

--
Dave Chinner
david@fromorbit.com