1. A method of operating a primary data processor and a secondary data processor for access to a file system in data storage, said method comprising: the primary data processor pre-allocating data blocks of the data storage to the file system before the pre-allocated data blocks are needed by the secondary data processor for extending the file system, and the secondary data processor using at least some of the pre-allocated data blocks for extending the file system, wherein the primary data processor pre-allocates an initial chunk size of data blocks when the file system is created, and upon expiration of a release timeout duration from the pre-allocation of the initial chunk size, the secondary data processor releases to the primary data processor an excess of the pre-allocated data blocks over a release threshold.