i_e2fs_nblock_high
nblock |= (uint64_t)ip->i_e2fs_nblock_high << 32;
ip->i_e2fs_nblock_high = (nblock >> 32) & 0xffff;
ip->i_e2fs_nblock_high = (EXT2_DBTOFSB(fs, nblock) >> 32) & 0xffff;