TRANSACTIONAL FLASH FILE SYSTEM FOR MICROCONTROLLERS AND EMBEDDED SYSTEMS

摘要

A transactional file system for a flash memory is based on persistent data structures that preferably are versloned trees. Only two copies of each tree are maintained: a read-write current version and a read-only previous version. Each internal node of each tree includes a spare pointer. Internal nodes are modifies by changing their spare pointers. Tentative changes to the current versions are marked using commit andabort flags in the internal nodes, and corresponding indications are logged. The tentative changes are committed or aborted in accordance with the logged indications. Awitness marker in the log and a witness heqder eleswhare in the flash memory are used at boot time to identify the log.