[PATCH v3 0/4] Add xxhash and zstd modules

[Nick Terrell]

Hi all,

This patch set adds xxhash, zstd compression, and zstd decompression
modules. It also adds zstd support to BtrFS and SquashFS.

Each patch has relevant summaries, benchmarks, and tests.

Best,
Nick Terrell

Changelog:

v1 -> v2:
- Make pointer in lib/xxhash.c:394 non-const (1/4)
- Use div_u64() for division of u64s (2/4)
- Reduce stack usage of ZSTD_compressSequences(), ZSTD_buildSeqTable(),
  ZSTD_decompressSequencesLong(), FSE_buildDTable(), FSE_decompress_wksp(),
  HUF_writeCTable(), HUF_readStats(), HUF_readCTable(),
  HUF_compressWeights(), HUF_readDTableX2(), and HUF_readDTableX4() (2/4)
- No zstd function uses more than 400 B of stack space (2/4)

v2 -> v3:
- Work around gcc-7 bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388
  (2/4)
- Fix bug in dictionary compression from upstream commit cc1522351f (2/4)
- Port upstream BtrFS commits e1ddce71d6, 389a6cfc2a, and 6acafd1eff (3/4)
- Change default compression level for BtrFS to 3 (3/4)

Nick Terrell (4):
  lib: Add xxhash module
  lib: Add zstd modules
  btrfs: Add zstd support
  squashfs: Add zstd support

 fs/btrfs/Kconfig           |    2 +
 fs/btrfs/Makefile          |    2 +-
 fs/btrfs/compression.c     |    1 +
 fs/btrfs/compression.h     |    6 +-
 fs/btrfs/ctree.h           |    1 +
 fs/btrfs/disk-io.c         |    2 +
 fs/btrfs/ioctl.c           |    6 +-
 fs/btrfs/props.c           |    6 +
 fs/btrfs/super.c           |   12 +-
 fs/btrfs/sysfs.c           |    2 +
 fs/btrfs/zstd.c            |  435 ++++++
 fs/squashfs/Kconfig        |   14 +
 fs/squashfs/Makefile       |    1 +
 fs/squashfs/decompressor.c |    7 +
 fs/squashfs/decompressor.h |    4 +
 fs/squashfs/squashfs_fs.h  |    1 +
 fs/squashfs/zstd_wrapper.c |  150 ++
 include/linux/xxhash.h     |  236 +++
 include/linux/zstd.h       | 1157 +++++++++++++++
 include/uapi/linux/btrfs.h |    8 +-
 lib/Kconfig                |   11 +
 lib/Makefile               |    3 +
 lib/xxhash.c               |  500 +++++++
 lib/zstd/Makefile          |   18 +
 lib/zstd/bitstream.h       |  374 +++++
 lib/zstd/compress.c        | 3479 ++++++++++++++++++++++++++++++++++++++++++++
 lib/zstd/decompress.c      | 2526 ++++++++++++++++++++++++++++++++
 lib/zstd/entropy_common.c  |  243 ++++
 lib/zstd/error_private.h   |   53 +
 lib/zstd/fse.h             |  575 ++++++++
 lib/zstd/fse_compress.c    |  795 ++++++++++
 lib/zstd/fse_decompress.c  |  332 +++++
 lib/zstd/huf.h             |  212 +++
 lib/zstd/huf_compress.c    |  770 ++++++++++
 lib/zstd/huf_decompress.c  |  960 ++++++++++++
 lib/zstd/mem.h             |  151 ++
 lib/zstd/zstd_common.c     |   75 +
 lib/zstd/zstd_internal.h   |  250 ++++
 lib/zstd/zstd_opt.h        | 1014 +++++++++++++
 39 files changed, 14382 insertions(+), 12 deletions(-)
 create mode 100644 fs/btrfs/zstd.c
 create mode 100644 fs/squashfs/zstd_wrapper.c
 create mode 100644 include/linux/xxhash.h
 create mode 100644 include/linux/zstd.h
 create mode 100644 lib/xxhash.c
 create mode 100644 lib/zstd/Makefile
 create mode 100644 lib/zstd/bitstream.h
 create mode 100644 lib/zstd/compress.c
 create mode 100644 lib/zstd/decompress.c
 create mode 100644 lib/zstd/entropy_common.c
 create mode 100644 lib/zstd/error_private.h
 create mode 100644 lib/zstd/fse.h
 create mode 100644 lib/zstd/fse_compress.c
 create mode 100644 lib/zstd/fse_decompress.c
 create mode 100644 lib/zstd/huf.h
 create mode 100644 lib/zstd/huf_compress.c
 create mode 100644 lib/zstd/huf_decompress.c
 create mode 100644 lib/zstd/mem.h
 create mode 100644 lib/zstd/zstd_common.c
 create mode 100644 lib/zstd/zstd_internal.h
 create mode 100644 lib/zstd/zstd_opt.h

--
2.9.3