mkfs: add a formatting option for exchange-range Allow users to enable the logged file mapping exchange intent items on a filesystem, which in turn enables XFS_IOC_EXCHANGE_RANGE and online repair of metadata that lives in files, e.g. directories and xattrs. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>