HashTag: Fast Lookup in a Persistent Memory Filesystem

Persistent Memory (PM) offers byte-addressability and persistence on the memory bus, and delivers dramatic performance improvements over traditional storage media. While many filesystems have been optimized for PM, a large fraction of processing time is generally spent locating the required data in PM due to the standard use of extent-trees for location indexing. This paper presents HashTag, a cache of PM locations for use in PM filesystems with support for snapshot creation. We evaluate HashTag across a range of configurations to determine the impact of various location caching options on filesystem performance. These lessons can inform the design of future caching solutions in PM filesystems. (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms. 

Resources 

The paper can be found at: https://ieeexplore.ieee.org/document/9926368