A file system which ensures that some of the (desired) files (“linear files”) are stored in corresponding exclusive blocks (i.e., a block that stores data corresponding to one file only). Due to such a feature, rewriting of data corresponding to other files would not cause data corresponding to linear files to be relocated/rewritten. Such a feature may provide reliable and steady retrieval of data of the corresponding file from a flash memory organized as sectors. According to another aspect, some of the files (“non-linear files”) are stored in non-exclusive blocks (i.e., multiple files can share the same block or the same file can span multiple blocks without contiguity).