Lockify: Understanding Linux Distributed Lock Management Overheads in Shared Storage

This paper presents Lockify, a novel distributed lock manager (DLM) for shared-disk file systems. Our key observation in shared-storage scenarios is that, for file or directory creation, lock acquisition overhead in the Linux kernel DLM increases with the number of clients, even in low-contention scenarios. Lockify minimizes this lock acquisition latency by avoiding unnecessary communication with remote directory nodes through self-owner notifications and asynchronous ownership management. We implement Lockify in the Linux kernel and evaluate its performance on real-world workloads using two representative shared-disk file systems, GFS2 and OCFS2. Our experimental results demonstrate that Lockify improves overall throughput by ~6.4× compared to the kernel DLM and O2CB, consistently across different numbers of clients.