Disk block controller and file system which supports large files by

Abstract

A disk block controller and file system support large extended files by using special logical blocks which contain a number of sequential physical disk blocks. The disk block controller includes a file creation support unit, an extended management unit, a first and second management units, and an allocation unit. The file creation support unit separates free physical disk blocks into a region with a small number of sequential empty physical disk block spaces and a region with a large number of sequential empty physical disk block spaces, and allocates these regions to different parts of the disk. The extended management unit manages a start and sequential block numbers for sequential empty physical disk blocks having specified entries and is utilized for extended files whose logical block size is an integral multiple of a physical block. The first and second management units manages start and sequential block numbers for sequential empty physical disk block spaces that are not covered by the extended management unit. The allocation unit finds sequential empty physical disk blocks whose sequential block number is greater than the number requested according to the management data provided by the second management unit and is used for allocating as many sequential empty physical blocks as requested.