This paper presents a scalable page cache called ScaleCache for improving SSD scalability. Specifically, we first propose a concurrent data structure of page cache based on XArray (ccXArray) to enable access and update the page cache concurrently. Second, we introduce a direct page flush (dflush) which directly flushes pages to storage devices in a parallel and opportunistic manner. We implement ScaleCache with two techniques in the Linux kernel and evaluate it on a 64-core machine with eight NVMe SSDs. Our evaluations show that ScaleCache improves the performance of Linux file systems by up to 6.81× and 4.50× compared with the existing scheme and scalable scheme for multiple SSDs, respectively.

This paper introduces a novel file system, ScaleDFS, designed to accelerate decentralized file sharing for a private network, leveraging the potential of scaling file management based on directed acyclic graph (DAG) on modern hardware. Specifically, in ScaleDFS, we first design a DAG builder that parallelizes the construction of DAG nodes for a file while preserving critical orders to speed up the uploading process. Second, we introduce a DAG reader that retrieves leaf DAG nodes in parallel without graph traversal assisted by a devised DAG cache to accelerate the downloading process. Finally, we present a DAG remover that rapidly identifies obsolete DAG nodes/data and removes them in parallel to mitigate the garbage collection overhead without compromising consistency. We implement ScaleDFS based on IPFS and demonstrate that ScaleDFS outperforms IPFS by up to 3.7×, 1.8×, and 12.6× in realistic file, private blockchain, and gateway workloads, respectively.