Optimizing memory usage and system performance in a file system requiring entire blocks to be erased for rewriting data

摘要

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).

主权项

1. A method of supporting a file system on a storage medium containing a plurality of blocks, wherein rewriting a portion of a block requires erasure of data in at least another portion of said block, said method comprising:
storing in a nonvolatile memory data indicating whether each of said plurality of blocks is used to store a linear file, wherein the linear file is entirely stored in a single contiguous block of memory lying within the bounds of a sector; and wherein each of said plurality of blocks is not used for storing another file if data in said non-volatile memory indicates that the block is used to store a linear file.