XFS_IPRESERVE_DM_FIELDS
xfs_iflags_set(ip, XFS_IPRESERVE_DM_FIELDS);
if (xfs_iflags_test(ip, XFS_IPRESERVE_DM_FIELDS))
xfs_iflags_clear(ip, XFS_IPRESERVE_DM_FIELDS);
if (xfs_iflags_test(ip, XFS_IPRESERVE_DM_FIELDS)) {