The latest production release of the project Littlefs 2.10 has been announced. Littlefs is a compact file system designed for built-in devices and microcontrollers. Originally developed by ARM for the MBED OS operating system, Littlefs has now become a separate project. The file system code is written in SI and distributed under the BSD license. The reference implementation of Littlefs is provided as a SI-library, which serves as the foundation for various related projects including a fuse module and bindings for different programming languages.
Key features of Littlefs include:
- Low resource requirements and support for operation in a limited amount of RAM. The implementation uses statically defined buffers and avoids recursive calls, ensuring that RAM usage and file system structures on the drive remain constant regardless of the data stored.
- Built-in wear leveling mechanisms for flash storage devices, which help optimize the use of blocks and evenly distribute operations on the flash memory.
- High resistance to failures, with the file system maintaining data integrity even in the event of unexpected interruptions such as power outages. Littlefs employs the Copy-on-write (cow) mechanism to prevent data loss and corruption.
- Atomicity of operations such as deletion and renaming, ensuring consistency in file updates even in the face of sudden power loss. Changes are only committed to the disk after a sync or close operation.
- Support for posix-like functions for file and directory manipulation.
File contents are represented by COW-list CTZ, providing efficient complexity levels for adding and reading data. Block allocation is managed through scanning the file system for utilized blocks, stored in a bit vector format. In case of block write errors, data is transferred to a new block to maintain data integrity.
The latest version of Littlefs introduces several changes and improvements, further enhancing its functionality and reliability for embedded systems.