Per-block-group journaling for improving fsync response time

The journaling is indispensable to the file systems of battery-backed consumer devices. It can cope with sudden power failures guaranteeing the file system consistency. However, the current compound transaction scheme can incur significantly long latencies for fsync system calls. This paper proposes a new more fine-grained journaling scheme called per-block-group journaling. Experiments show that the proposed scheme can reduce the average response time of fsync by up to 75%.