Function fs_ioc_enable_verity 

pub(super) fn fs_ioc_enable_verity<H: FsVerityHashValue>(
    fd: impl AsFd,
) -> Result<(), EnableVerityError>

Enable fsverity on the target file. This is a thin safe wrapper for the underlying base ioctl and hence all constraints apply such as requiring the file descriptor to already be O_RDONLY etc.