Dr. Charles P. Wright
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I am currently a Research Staff Member at the IBM T. J. Watson Research Center working in the Network Server Systems Software group.

Previously, I was a Ph.D. student at The State University of New York at Stony Brook majoring in Computer Science affiliated with the File Systems and Storage Lab, with Erez Zadok as my advisor. My primary interest was in data and operating system security. My disseratation topic was extending transactional semantics (atomicity, consistency, isolation, and durability) to the file system. I defended my dissertation and graduated in May 2006.

I graduated with a B.S. from SUNY Stony Brook in May 2003 (Summa Cum Laude) majoring in Computer Science and Applied Mathematics and Statistics. I obtained a 4.0 GPA in both of my majors, and received departmental honors in Computer Science. My honors project was NCryptfs: A Secure and Convenient Cryptographic File System, with Erez Zadok acting as my advisor.

I also received an M.S. in Computer Science from SUNY Stony Brook in May 2003. My thesis was Operating Systems Support for Extensible Secure File Systems.

Research Interests

My area of interest is operating systems with a focus on file systems. Data is the central part of most computer systems, and file systems are tasked with most data management. Through these projects I have gained extensive experience with Linux kernel internals, the VFS, and storage technologies.

Within this field I want to investigate how file systems can be made more secure, yet remain a convenient and fast interface for programmers, system administrators, and users. To these ends I am leading several projects:

• Amino: a system that extends transaction semantics (atomicity, consistency, isolation, and durability) to applications that use the POSIX interface. Amino is built on top of Sleepycat's Berkeley Database using a user-level ptrace monitor. Amino provides end-to-end transactions for file system operations and also application data structures. I am currently developing this project into my thesis.
  Abstract (PDF)
• Unionfs: a fan-out unification file system that supports Unix semantics. We have released Unionfs for Linux 2.4 and 2.6 under the GPL, and it is available for download. Unionfs is in use by more than a dozen other distributions (including Knoppix and SLAX), and has been downloaded by thousands of users.
  
• Auto-pilot: a suite for benchmarking systems software. Auto-pilot includes a scripting language for defining benchmarks, a tools to statistically analyze, and a Gnuplot front-end for graphing the results. We have used Auto-pilot for benchmarking dozens of file systems, and it has saved us quite a bit of time.
  This work appeared in the FREENIX track of Annual USENIX Technical Conference in April 2005.
• nCryptfs: a next generation cryptographic file system. nCryptfs aims to balance the competing concerns of security and convenience. nCryptfs supports multiple ciphers, authentication methods, and key timeouts with transparent process suspension and resumption.
  This work appeared in the Annual USENIX Technical Conference in June 2003.

• Avfs: an on-access anti-virus file system. By scanning on page reads and writes, Avfs detects a virus before it is committed to stable storage or returned to the user. Avfs uses a state-oriented design for improved performance, as well as improving the scalability of the ClamAV open-source virus scanner.
  This work appeared will appear the 2004 USENIX Security Symposium in August 2004.
• Tracefs: Tracefs is a stackable file system that records file system operations, including mmap reads and writes. Tracefs allows arbitrarily complex expressions to determine what should be traced, and a rich set of output filters to perform transformations on the traced output.
  This work appeared at the Third USENIX Conference on File and Storage Technologies (FAST '04).
• Versionfs: A Versatile and User-Oriented File System. Versionfs transparently creates backups when a file is modified using copy-on-change. Versionfs allows the user to select a variety of retention policies to determine what versions to save (based on time, extension, space usage, and number of versions) . Versionfs has multiple storage policies that determine how a file is stored: full backups, compressed backups, or block differences.
  This work appeared at the Third USENIX Conference on File and Storage Technologies (FAST '04).
• OS Performance Profiling: Modern Operating Systems consist of a number of components that despite having different purposes strongly influence each other. Unfortunately, existing OS profiling systems concentrate on some particular OS component or profile only CPU or I/O activity. Therefore, the information collected is often not sufficient to discover and easily understand possible OS performance problems. In this project we investigate techniques that allow to capture, visualize, and analyze statistical information about the OS operation as a whole, as well as several OSs that communicate over the network.
• Cosy: a project aimed at improving system performance through system call composition. This is somewhat similar to compound operations in NFSv4.
  This work appeared at the Ninth Workshop on Hot Topics in Operating Systems (HotOS-IX).
• Elastic Quotas: a novel method for disk space management. Elastic quotas allow a user to exceed their persistent disk space quota while disk space is available. The user guarantees that the system will be able to reclaim this additional space when resources become scarce.
  This work appeared at the 2004 NASA/IEEE Conference on Mass Storage Systems and Technologies.