1. A method implemented at least in part by a computer, the method comprising: at a data access component, receiving a write request directed at a storage container, the write request involving storage locations of data represented by a token, the token previously issued by an offload provider responsible for ensuring that the data represented by the token is not allowed to change while the token is valid; in response to receiving the write request, performing an action, the action depending on implementation of the offload provider, the action including one or more of: invalidating the token, copying the data affected by the write request to another storage location, copying the data affected by the write request to other memory that includes volatile and/or nonvolatile elements in conjunction with updating the token to reference the other memory, unsparing shared storage locations used to store the data, and causing the write request to write to a new storage location that does not affect the data represented by the token.