func NewFiemapFile(f *os.File) FiemapFile {
	return FiemapFile{f}
}
NewFiemapFile : return a new FibmapFile
package sparse
import (
	"os"
	"syscall"
	"unsafe"
)
const (
	FiemapSize = 32  
	ExtentSize = 56  
	FS_IOC_FIEMAP = 3223348747
	FIEMAP_MAX_OFFSET            = ^uint64(0)
	FIEMAP_FLAG_SYNC             = 0x0001  
	FIEMAP_FLAG_XATTR            = 0x0002  
	FIEMAP_FLAG_CACHE            = 0x0004  
	FIEMAP_FLAGS_COMPAT          = (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
	FIEMAP_EXTENT_LAST           = 0x0001  
	FIEMAP_EXTENT_UNKNOWN        = 0x0002  
	FIEMAP_EXTENT_DELALLOC       = 0x0004  
	FIEMAP_EXTENT_ENCODED        = 0x0008  
	FIEMAP_EXTENT_DATA_ENCRYPTED = 0x0080  
	FIEMAP_EXTENT_NOT_ALIGNED    = 0x0100  
	FIEMAP_EXTENT_DATA_INLINE    = 0x0200  
	FIEMAP_EXTENT_DATA_TAIL      = 0x0400  
	FIEMAP_EXTENT_UNWRITTEN      = 0x0800  
	FIEMAP_EXTENT_MERGED         = 0x1000  
	FIEMAP_EXTENT_SHARED         = 0x2000  
	FALLOC_FL_KEEP_SIZE    = 0x01  
	FALLOC_FL_PUNCH_HOLE   = 0x02  
	FALLOC_FL_NO_HIDE_STAE = 0x04  
)
type fiemap struct {
	Start         uint64  
	Length        uint64  
	Flags         uint32  
	MappedExtents uint32  
	ExtentCount   uint32  
	Reserved      uint32
}
type Extent struct {
	Logical    uint64  
	Physical   uint64  
	Length     uint64  
	Reserved64 [2]uint64
	Flags      uint32  
	Reserved   [3]uint32
}
type FiemapFile struct {
	*os.File
}