Patent ID: 7886291

Claim:
A layered computing system discriminating a priority among a plurality of enabled layers identified by a layer type, the types of layers recognized by the system including an application layer type, said system comprising: a processor; data and program storage accessible by said processor, said storage comprising one or more data storage devices; an operating system stored to said storage; and computer readable instructions located to said program storage, wherein said instructions are configured to be executed by said processor to perform the functions of: (i) receiving from an application a request to perform a file operation, that request containing a file reference appropriate to a file system, (ii) identifying a set of enabled layers, wherein each layer in the set of enabled layers comprises a filesystem layer, (iii) determining a priority for searching the enabled layers and a base filesystem, wherein the determined priority ranks layers identified as one type over other layers identified by a second type, (iv) performing a search for a file object corresponding to the file reference, the search performed in order of the determined priority, (v) making a first determination that, in performing the search, a file object is not found corresponding to the file reference, (vi) making a second determination that the request was a write request, (vii) in response to the first and second determinations, returning a virtual file handle or a base file handle to a new file object in the layer having priority.