_LINUX_IOC_READ    64 compat/linux/linux_ioctl.h 	_LINUX_IOC(_LINUX_IOC_READ,(type),(nr),sizeof(size))
_LINUX_IOC_READ    68 compat/linux/linux_ioctl.h 	_LINUX_IOC(_LINUX_IOC_READ|_LINUX_IOC_WRITE,(type),(nr),sizeof(size))