Overriding queryset for inline admin

I'm having some trouble overriding the queryset for my inline admin.

Here's a bog-standard parent admin and inline admin:

class MyInlineAdmin(admin.TabularInline):
    model = MyInlineModel
    def queryset(self, request):
        qs = super(MyInlineAdmin, self).queryset(request)
        return qs

class ParentAdmin(admin.ModelAdmin):
    inlines = [MyInlineAdmin]
admin.site.register(ParentAdminModel, ParentAdmin)

Now I can do qs.filter(user=request.user) or qs.filter(date__gte=datetime.today()) no problem.

But what I need is either the MyInlineModel instance or the ParentAdminModel instance (not the model!), as I need to filter my queryset based on that.

Is it possible to get something like self.instance or obj (like in get_readonly_fields() or get_formset()) inside the queryset() method?

Hope this makes sense. Any help is much appreciated.