blob: 35b03d1f14aeecf63f6db52f39854587e6b53022 [file] [log] [blame]
// +build linux
package loopback // import "github.com/docker/docker/pkg/loopback"
import (
"unsafe"
"golang.org/x/sys/unix"
)
func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
// The ioctl interface for /dev/loop-control (since Linux 3.1) is a bit
// off compared to what you'd expect: instead of writing an integer to a
// parameter pointer like unix.IoctlGetInt() expects, it returns the first
// available loop device index directly.
ioctlReturn, _, err := unix.Syscall(unix.SYS_IOCTL, fd, LoopCtlGetFree, 0)
if err != 0 {
return 0, err
}
return int(ioctlReturn), nil
}
func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {
return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_FD, int(sparseFd))
}
func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *unix.LoopInfo64) error {
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_SET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return err
}
return nil
}
func ioctlLoopClrFd(loopFd uintptr) error {
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_CLR_FD, 0); err != 0 {
return err
}
return nil
}
func ioctlLoopGetStatus64(loopFd uintptr) (*unix.LoopInfo64, error) {
loopInfo := &unix.LoopInfo64{}
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_GET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return nil, err
}
return loopInfo, nil
}
func ioctlLoopSetCapacity(loopFd uintptr, value int) error {
return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_CAPACITY, value)
}