Low level FS implementation

A document that outlines the design and implementation details of a custom file system (FS).

Components

• Partitioning: Storage is divided into superblocks, bitmaps (inode and block), inode tables, and data blocks. The superblock tracks metadata and extents (start and size) of each component.
• Inodes and Extents:
  • Inodes store file metadata and up to 11 direct extents.
  • Files exceeding 11 extents use an indirect block to track additional extents.
• File Operations:
  • Allocation: Bitmaps identify free inodes or blocks.
  • Truncation/Deletion: Updates bitmaps and compacts directory entries to reclaim space efficiently.
  • Path Resolution: Navigates directories to locate inodes for target files.

Performance

Memory management algorithms (FIFO, LRU, CLOCK, MRU, and RAND) are compared across workloads like blocked, matmul, and repeat loop:

• Blocked Access: High hit rates for LRU, FIFO, and CLOCK due to focused memory access.
• Matmul: Increased evictions from interruptions in access patterns.
• Repeat Loop: Larger memory reduces evictions significantly.
• Simple Loop: Low hit rates due to constant data swapping.

The project was implemented in C.