// +build linux package devicemapper import ( "syscall" "unsafe" ) func ioctlBlkGetSize64(fd uintptr) (int64, error) { var size int64 if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, BlkGetSize64, uintptr(unsafe.Pointer(&size))); err != 0 { return 0, err } return size, nil } func ioctlBlkDiscard(fd uintptr, offset, length uint64) error { var r [2]uint64 r[0] = offset r[1] = length if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, BlkDiscard, uintptr(unsafe.Pointer(&r[0]))); err != 0 { return err } return nil }