Fix a Distributed File Systems Race Condition

Consider the following rules for a shared-resource system:

There are n shared data resources and m clients where n and m are positive integers. The resources are accessed via a network connection. The clients may read and write to the shared resources and may only execute one operation at a time. Clients read and write requests are served sequentially as they are received.

Propose rule changes and possible additional operations on resources besides read or write that would ensure the following:

No clients modifications can be overwritten by another clients out-of-date revisions.

It may help to add new operations in addition to read and write, as well as enforce rules on the order in which a client can execute operations. Please provide a scenario, incorporating the operations and rules, on how the system works.