xfs_bmbt_block_len
blocklen -= xfs_bmbt_block_len(mp);
((char *)block + xfs_bmbt_block_len(mp) +
return xfs_bmbt_block_len(mp) +
((char *)block + xfs_bmbt_block_len(mp) +
((char *)block + xfs_bmbt_block_len(mp) +
2 * xfs_bmbt_block_len(mp));