static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct file *file = vma->vm_file;
	struct shm_file_data *sfd = shm_file_data(file);

	return sfd->vm_ops->fault(vma, vmf);
}
static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct file *file = vma->vm_file;
	struct shm_file_data *sfd = shm_file_data(file);

	return sfd->vm_ops->fault(vma, vmf);
}