1. A method comprising: receiving, by a file system driver stored in a computational device, a request to provide access to a snapshot of a rewritable file system at a selected point in time, wherein a plurality of tokens corresponding to a plurality of data units are stored in the rewritable file system, and wherein an ordering relationship is maintained among the plurality of tokens; determining a token corresponding to the selected point in time based on the ordering relationship; generating a virtual subdirectory name corresponding to the determined token; creating a virtual subdirectory with the generated virtual subdirectory name, wherein the virtual subdirectory is a subdirectory of a root directory; and accessing, the snapshot, via the subdirectory.