1. A mass storage memory system, comprising: re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells; a controller that receives files of data individually via a first host-system-accessible interface of the mass storage memory system, where the files are identified by unique identifiers, wherein the received file data is stored in one or more of the blocks of memory cells and indexed based on the unique identifiers; wherein the controller assigns a plurality of logical block addresses to the received file data and updates directory and file allocation table (“FAT”) entries that are used by a host and that are stored in the one or more of the blocks of memory cells such that the file data received via the first host-system-accessible interface is accessible via a second host-system-accessible interface of the mass storage memory system; wherein the first host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a first address space; and wherein the second host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a second address space distinct from the first address space.