The just distribution of scarce goods is not rationing.
Typically, free market results do not guarantee fair income distribution or allocation of resources. Therefore this is why in many states the goverments intervenes in the economy, to perform a subsequent redistribution.
Rationing is not related to this idea. Moreover, it is triggered by an undesirable market result that take place when the amount demanded exceeds the amount supplied at the established price level, and some consumers are not able to purchase the desired good and in turn to satisfy their underlying need. A rationing mechanism can be imposed to limit the amount of consumption that each person can have access to. But this tecnique, although it palliates a market flow, it does not guarantee a fair redistribution, because in many cases it is based on first come-first served or other arbitrary mechanisms, instead of being based on willingness to pay, income, preferences or any other rationalized mechanism.