void unlink_file_vma(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;

	if (file) {
		struct address_space *mapping = file->f_mapping;
		i_mmap_lock_write(mapping);
		__remove_shared_vm_struct(vma, file, mapping);
		i_mmap_unlock_write(mapping);
	}
}
void unlink_file_vma(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;

	if (file) {
		struct address_space *mapping = file->f_mapping;
		i_mmap_lock_write(mapping);
		__remove_shared_vm_struct(vma, file, mapping);
		i_mmap_unlock_write(mapping);
	}
}