MetaCache: Efficient Metadata Caching in Linux file system
  Nowadays, Linux file systems have to manage millions of tiny files for different applications, and face with higher metadata operations. So how to provide such high metadata performance with such enormous number of files and large scale directories is a big challenge for Linux file system. We viewed that metadata lookup operations dominate metadata workload and incur low metadata performance. In this paper, we present a metadata cache to accelerate metadata access for Linux file system. Through this optimization, the Linux file system (such as EXT2, EXT4, BTRFS, etc.) can gain improvement in read rates as well as write rates. 
Tanmay Agrawal, Ashay Shirwadkar, Pratik Gaikar, Kushagra Verma
cs.SY