While flash memory has been widely adopted for storage systems for various embedded systems, issues on performance and reliability have started receiving growing attention in recent years. How to provide efficient roll back and quick mounting for flash-memory file systems has become important research topics in recent years, in addition to the work on effective garbage collection and superb run-time performance. Such an observation motivates our work on the investigation of efficient initialization and crash recovery of flash-memory file systems based on log structures. A methodology is proposed for the acceleration of mounting and crash recovery for log-based file systems. A system prototype based on a well-known flash-memory file system YAFFS was implemented with performance evaluation. The experimental results show that the proposed methodology can reduce the mounting time significantly, regardless of whether the file system is properly unmounted.