This is an RFC patch series that impements NOVA (NOn-Volatile memory Accelerated file system), a new file system built for PMEM. NOVA's goal is to provide a high-performance, full-featured, production-ready file system tailored for byte-addressable non-volatile memories (e.g., NVDIMMs and Intel's soon-to-be-released 3DXpoint DIMMs). It combines design elements from many other file systems to provide a combination of high-performance, strong consistency guarantees, and comprehensive data protection. NOVA supports DAX-style mmap, and making DAX perform well is a first-order priority in NOVA's design. NOVA was developed at the Non-Volatile Systems Laboratory in the Computer Science and Engineering Department at the University of California, San Diego. Its primary authors are Andiry Xu <jix024@xxxxxxxxxxxx>, Lu Zhang <luzh@xxxxxxxxxxxx>, and Steven Swanson <swanson@xxxxxxxxxxxx>. NOVA is stable enough to run complex applications, but there is substantial work left to do. This RFC is intended to gather feedback to guide its development toward eventual inclusion upstream. The patches are relative Linux 4.12. Overview ======== NOVA is primarily a log-structured file system, but rather than maintain a single global log for the entire file system, it maintains separate logs for each file (inode). NOVA breaks the logs into 4KB pages, they need not be contiguous in memory. The logs only contain metadata. File data pages reside outside the log, and log entries for write operations point to data pages they modify. File modification uses copy-on-write (COW) to provide atomic file updates. For file operations that involve multiple inodes, NOVA use small, fixed-sized redo logs to atomically append log entries to the logs of the inodes involved. This structure keeps logs small and makes garbage collection very fast. It also enables enormous parallelism during recovery from an unclean unmount, since threads can scan logs in parallel. NOVA replicates and checksums all metadata structures and protects file data with RAID-4-style parity. It supports checkpoints to facilitate backups. Documentation/filesystems/NOVA.txt contains some lower-level implementation and usage information. A more thorough discussion of NOVA's goals and design is avaialable in two papers: NOVA: A Log-structured File system for Hybrid Volatile/Non-volatile Main Memories http://cseweb.ucsd.edu/~swanson/papers/FAST2016NOVA.pdf Jian Xu and Steven Swanson Published in FAST 2016 Hardening the NOVA File System http://cseweb.ucsd.edu/~swanson/papers/TechReport2017HardenedNOVA.pdf UCSD-CSE Techreport CS2017-1018 Jian Xu, Lu Zhang, Amirsaman Memaripour, Akshatha Gangadharaiah, Amit Borase, Tamires Brito Da Silva, Andy Rudoff, Steven Swanson -steve --- Steven Swanson (16): NOVA: Documentation NOVA: Superblock and fs layout NOVA: PMEM allocation system NOVA: Inode operations and structures NOVA: Log data structures and operations NOVA: Lite-weight journaling for complex ops NOVA: File and directory operations NOVA: Garbage collection NOVA: DAX code NOVA: File data protection NOVA: Snapshot support NOVA: Recovery code NOVA: Sysfs and ioctl NOVA: Read-only pmem devices NOVA: Performance measurement NOVA: Build infrastructure Documentation/filesystems/00-INDEX | 2 Documentation/filesystems/nova.txt | 771 +++++++++++++++++ MAINTAINERS | 8 README.md | 173 ++++ arch/x86/include/asm/io.h | 1 arch/x86/mm/fault.c | 11 arch/x86/mm/ioremap.c | 25 - drivers/nvdimm/pmem.c | 14 fs/Kconfig | 2 fs/Makefile | 1 fs/nova/Kconfig | 15 fs/nova/Makefile | 9 fs/nova/balloc.c | 827 +++++++++++++++++++ fs/nova/balloc.h | 118 +++ fs/nova/bbuild.c | 1602 ++++++++++++++++++++++++++++++++++++ fs/nova/checksum.c | 912 ++++++++++++++++++++ fs/nova/dax.c | 1346 ++++++++++++++++++++++++++++++ fs/nova/dir.c | 760 +++++++++++++++++ fs/nova/file.c | 943 +++++++++++++++++++++ fs/nova/gc.c | 739 +++++++++++++++++ fs/nova/inode.c | 1467 +++++++++++++++++++++++++++++++++ fs/nova/inode.h | 389 +++++++++ fs/nova/ioctl.c | 185 ++++ fs/nova/journal.c | 474 +++++++++++ fs/nova/journal.h | 61 + fs/nova/log.c | 1411 ++++++++++++++++++++++++++++++++ fs/nova/log.h | 333 +++++++ fs/nova/mprotect.c | 604 ++++++++++++++ fs/nova/mprotect.h | 190 ++++ fs/nova/namei.c | 919 +++++++++++++++++++++ fs/nova/nova.h | 1137 ++++++++++++++++++++++++++ fs/nova/nova_def.h | 154 +++ fs/nova/parity.c | 411 +++++++++ fs/nova/perf.c | 594 +++++++++++++ fs/nova/perf.h | 96 ++ fs/nova/rebuild.c | 847 +++++++++++++++++++ fs/nova/snapshot.c | 1407 ++++++++++++++++++++++++++++++++ fs/nova/snapshot.h | 98 ++ fs/nova/stats.c | 685 +++++++++++++++ fs/nova/stats.h | 218 +++++ fs/nova/super.c | 1222 +++++++++++++++++++++++++++ fs/nova/super.h | 216 +++++ fs/nova/symlink.c | 153 +++ fs/nova/sysfs.c | 543 ++++++++++++ include/linux/io.h | 2 include/linux/mm.h | 2 include/linux/mm_types.h | 3 kernel/memremap.c | 24 + mm/memory.c | 2 mm/mmap.c | 1 mm/mprotect.c | 13 51 files changed, 22129 insertions(+), 11 deletions(-) create mode 100644 Documentation/filesystems/nova.txt create mode 100644 README.md create mode 100644 fs/nova/Kconfig create mode 100644 fs/nova/Makefile create mode 100644 fs/nova/balloc.c create mode 100644 fs/nova/balloc.h create mode 100644 fs/nova/bbuild.c create mode 100644 fs/nova/checksum.c create mode 100644 fs/nova/dax.c create mode 100644 fs/nova/dir.c create mode 100644 fs/nova/file.c create mode 100644 fs/nova/gc.c create mode 100644 fs/nova/inode.c create mode 100644 fs/nova/inode.h create mode 100644 fs/nova/ioctl.c create mode 100644 fs/nova/journal.c create mode 100644 fs/nova/journal.h create mode 100644 fs/nova/log.c create mode 100644 fs/nova/log.h create mode 100644 fs/nova/mprotect.c create mode 100644 fs/nova/mprotect.h create mode 100644 fs/nova/namei.c create mode 100644 fs/nova/nova.h create mode 100644 fs/nova/nova_def.h create mode 100644 fs/nova/parity.c create mode 100644 fs/nova/perf.c create mode 100644 fs/nova/perf.h create mode 100644 fs/nova/rebuild.c create mode 100644 fs/nova/snapshot.c create mode 100644 fs/nova/snapshot.h create mode 100644 fs/nova/stats.c create mode 100644 fs/nova/stats.h create mode 100644 fs/nova/super.c create mode 100644 fs/nova/super.h create mode 100644 fs/nova/symlink.c create mode 100644 fs/nova/sysfs.c -- Signature
