moby/pkg/loopback/ioctl.go
Vincent Batts af59752712 loopback: separate loop logic from devicemapper
The loopback logic is not technically exclusive to the devicemapper
driver. This reorganizes the code such that the loopback code is usable
outside of the devicemapper package and driver.

Signed-off-by: Vincent Batts <vbatts@redhat.com>
2015-12-18 10:57:43 -05:00

53 lines
1.3 KiB
Go

// +build linux
package loopback
import (
"syscall"
"unsafe"
)
func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
index, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, LoopCtlGetFree, 0)
if err != 0 {
return 0, err
}
return int(index), nil
}
func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetFd, sparseFd); err != 0 {
return err
}
return nil
}
func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *loopInfo64) error {
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return err
}
return nil
}
func ioctlLoopClrFd(loopFd uintptr) error {
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopClrFd, 0); err != 0 {
return err
}
return nil
}
func ioctlLoopGetStatus64(loopFd uintptr) (*loopInfo64, error) {
loopInfo := &loopInfo64{}
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopGetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return nil, err
}
return loopInfo, nil
}
func ioctlLoopSetCapacity(loopFd uintptr, value int) error {
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, loopFd, LoopSetCapacity, uintptr(value)); err != 0 {
return err
}
return nil
}