1. docker
  2. Commit 919d08347a22bfe1034a5da40f2d767ccfcdba97
Browse code

Use loopback types and constants from x/sys/unix to implement pkg/loopback without cgo

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

Tobias Klauser authored on 2019/08/09 22:38:32
Showing 4 changed files
pkg/loopback/attach_loopback.go
History View file @ 919d083
... ... 
@@ -1,4 +1,4 @@
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-// +build linux,cgo
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+// +build linux
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 package loopback // import "github.com/docker/docker/pkg/loopback"
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... ... 
@@ -116,10 +116,10 @@ func AttachLoopDevice(sparseName string) (loop *os.File, err error) {
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 	}
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 	// Set the status of the loopback device
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-	loopInfo := &loopInfo64{
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-		loFileName: stringToLoopName(loopFile.Name()),
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-		loOffset:   0,
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-		loFlags:    LoFlagsAutoClear,
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+	loopInfo := &unix.LoopInfo64{
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+		File_name: stringToLoopName(loopFile.Name()),
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+		Offset:    0,
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+		Flags:     LoFlagsAutoClear,
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 	}
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 	if err := ioctlLoopSetStatus64(loopFile.Fd(), loopInfo); err != nil {
pkg/loopback/ioctl.go
History View file @ 919d083
... ... 
@@ -1,4 +1,4 @@
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-// +build linux,cgo
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+// +build linux
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 package loopback // import "github.com/docker/docker/pkg/loopback"
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... ... 
@@ -17,32 +17,32 @@ func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
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 }
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 func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {
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-	return unix.IoctlSetInt(int(loopFd), LoopSetFd, int(sparseFd))
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+	return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_FD, int(sparseFd))
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 }
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-func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *loopInfo64) error {
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-	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, LoopSetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
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+func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *unix.LoopInfo64) error {
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+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_SET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
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 		return err
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 	}
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 	return nil
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 }
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 func ioctlLoopClrFd(loopFd uintptr) error {
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-	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, LoopClrFd, 0); err != 0 {
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+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_CLR_FD, 0); err != 0 {
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 		return err
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 	}
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 	return nil
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 }
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-func ioctlLoopGetStatus64(loopFd uintptr) (*loopInfo64, error) {
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-	loopInfo := &loopInfo64{}
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+func ioctlLoopGetStatus64(loopFd uintptr) (*unix.LoopInfo64, error) {
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+	loopInfo := &unix.LoopInfo64{}
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-	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, LoopGetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
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+	if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_GET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
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 		return nil, err
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 	}
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 	return loopInfo, nil
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 }
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 func ioctlLoopSetCapacity(loopFd uintptr, value int) error {
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-	return unix.IoctlSetInt(int(loopFd), LoopSetCapacity, value)
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+	return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_CAPACITY, value)
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 }
pkg/loopback/loop_wrapper.go
History View file @ 919d083
... ... 
@@ -1,52 +1,24 @@
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-// +build linux,cgo
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+// +build linux
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 package loopback // import "github.com/docker/docker/pkg/loopback"
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-/*
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-#include <linux/loop.h> // FIXME: present only for defines, maybe we can remove it?
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-
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-#ifndef LOOP_CTL_GET_FREE
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-  #define LOOP_CTL_GET_FREE 0x4C82
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-#endif
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-
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-#ifndef LO_FLAGS_PARTSCAN
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-  #define LO_FLAGS_PARTSCAN 8
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-#endif
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-
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-*/
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-import "C"
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-
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-type loopInfo64 struct {
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-	loDevice         uint64 /* ioctl r/o */
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-	loInode          uint64 /* ioctl r/o */
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-	loRdevice        uint64 /* ioctl r/o */
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-	loOffset         uint64
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-	loSizelimit      uint64 /* bytes, 0 == max available */
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-	loNumber         uint32 /* ioctl r/o */
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-	loEncryptType    uint32
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-	loEncryptKeySize uint32 /* ioctl w/o */
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-	loFlags          uint32 /* ioctl r/o */
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-	loFileName       [LoNameSize]uint8
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-	loCryptName      [LoNameSize]uint8
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-	loEncryptKey     [LoKeySize]uint8 /* ioctl w/o */
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-	loInit           [2]uint64
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-}
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+import "golang.org/x/sys/unix"
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 // IOCTL consts
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 const (
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-	LoopSetFd       = C.LOOP_SET_FD
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-	LoopCtlGetFree  = C.LOOP_CTL_GET_FREE
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-	LoopGetStatus64 = C.LOOP_GET_STATUS64
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-	LoopSetStatus64 = C.LOOP_SET_STATUS64
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-	LoopClrFd       = C.LOOP_CLR_FD
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-	LoopSetCapacity = C.LOOP_SET_CAPACITY
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+	LoopSetFd       = unix.LOOP_SET_FD
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+	LoopCtlGetFree  = unix.LOOP_CTL_GET_FREE
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+	LoopGetStatus64 = unix.LOOP_GET_STATUS64
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+	LoopSetStatus64 = unix.LOOP_SET_STATUS64
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+	LoopClrFd       = unix.LOOP_CLR_FD
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+	LoopSetCapacity = unix.LOOP_SET_CAPACITY
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 )
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 // LOOP consts.
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 const (
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-	LoFlagsAutoClear = C.LO_FLAGS_AUTOCLEAR
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-	LoFlagsReadOnly  = C.LO_FLAGS_READ_ONLY
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-	LoFlagsPartScan  = C.LO_FLAGS_PARTSCAN
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-	LoKeySize        = C.LO_KEY_SIZE
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-	LoNameSize       = C.LO_NAME_SIZE
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+	LoFlagsAutoClear = unix.LO_FLAGS_AUTOCLEAR
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+	LoFlagsReadOnly  = unix.LO_FLAGS_READ_ONLY
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+	LoFlagsPartScan  = unix.LO_FLAGS_PARTSCAN
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+	LoKeySize        = unix.LO_KEY_SIZE
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+	LoNameSize       = unix.LO_NAME_SIZE
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 )
pkg/loopback/loopback.go
History View file @ 919d083
... ... 
@@ -16,7 +16,7 @@ func getLoopbackBackingFile(file *os.File) (uint64, uint64, error) {
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 		logrus.Errorf("Error get loopback backing file: %s", err)
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 		return 0, 0, ErrGetLoopbackBackingFile
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 	}
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-	return loopInfo.loDevice, loopInfo.loInode, nil
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+	return loopInfo.Device, loopInfo.Inode, nil
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 }
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 // SetCapacity reloads the size for the loopback device.