loop

Documentation

Index

• Constants
• func GetMaxLoopDevices() int
• type Device
  • func (loop *Device) AttachFromFile(image *os.File, mode int, number *int) error
  • func (loop *Device) AttachFromPath(image string, mode int, number *int) error
  • func (loop *Device) Close() error
• type Info64
  • func GetStatusFromFd(fd uintptr) (*Info64, error)
  • func GetStatusFromPath(path string) (*Info64, error)

Constants

const (
	FlagsReadOnly  = 1
	FlagsAutoClear = 4
	FlagsPartScan  = 8
	FlagsDirectIO  = 16
)

Loop device flags values

const (
	CryptNone      = 0
	CryptXor       = 1
	CryptDes       = 2
	CryptFish2     = 3
	CryptBlow      = 4
	CryptCast128   = 5
	CryptIdea      = 6
	CryptDummy     = 9
	CryptSkipJack  = 10
	CryptCryptoAPI = 18
	CryptMax       = 20
)

Loop device encryption types

const (
	CmdSetFd       = 0x4C00
	CmdClrFd       = 0x4C01
	CmdSetStatus   = 0x4C02
	CmdGetStatus   = 0x4C03
	CmdSetStatus64 = 0x4C04
	CmdGetStatus64 = 0x4C05
	CmdChangeFd    = 0x4C06
	CmdSetCapacity = 0x4C07
	CmdSetDirectIO = 0x4C08
)

Loop device IOCTL commands

const (
	CmdCtlAdd     = 0x4C80
	CmdCtlRemove  = 0x4C81
	CmdCtlGetFree = 0x4C82
)

Loop control device IOCTL commands

Functions

func GetMaxLoopDevices

func GetMaxLoopDevices() int

GetMaxLoopDevices Return the maximum number of loop devices allowed

Types

type Device

type Device struct {
	MaxLoopDevices int
	Shared         bool
	Info           *Info64
	// contains filtered or unexported fields
}

Device describes a loop device

func (*Device) AttachFromFile

func (loop *Device) AttachFromFile(image *os.File, mode int, number *int) error

AttachFromFile attempts to find a suitable loop device to use for the specified image. It runs through /dev/loopXX, up to MaxLoopDevices to find a free loop device, or to share a loop device already associated to file (if shared loop devices are enabled). If a usable loop device is found, then loop.Fd is set and no error is returned. If a usable loop device is not found, and this is due to a transient EAGAIN / EBUSY error, then it will retry up to maxRetries times, retryInterval apart, before returning an error.

func (*Device) AttachFromPath

func (loop *Device) AttachFromPath(image string, mode int, number *int) error

AttachFromPath finds a free loop device, opens it, and stores file descriptor of opened image path

func (*Device) Close

func (loop *Device) Close() error

Close closes the loop device.

type Info64

type Info64 struct {
	Device         uint64
	Inode          uint64
	Rdevice        uint64
	Offset         uint64
	SizeLimit      uint64
	Number         uint32
	EncryptType    uint32
	EncryptKeySize uint32
	Flags          uint32
	FileName       [64]byte
	CryptName      [64]byte
	EncryptKey     [32]byte
	Init           [2]uint64
}

Info64 contains information about a loop device.

func GetStatusFromFd

func GetStatusFromFd(fd uintptr) (*Info64, error)

GetStatusFromFd gets info status about an opened loop device

func GetStatusFromPath

func GetStatusFromPath(path string) (*Info64, error)

GetStatusFromPath gets info status about a loop device from path