btrfs: Add zstd support to grub btrfs

Hi all,

This patch set imports the upstream zstd library, adds zstd support to the btrfs module, and adds a test case. I've also tested the patch set by storing my boot partition in btrfs with and without zstd compression and rebooting.

Best,
Nick Terrell

Changelog:

v1 -> v2:
- Switch to upstream zstd-1.3.6 and drop all the local patches.
- Fix comments from Daniel Kiper.

v2 -> v3:
- Remove an extra file accidentally included in the first patch.
- Use grub_error() to set grub_errno in grub_btrfs_zstd_decompress().
- Fix style and formatting comments.

v3 -> v4:
- Put zstd in its own module.
- Update commit messages.
- Use attribute unused.
- Rebase on top of RAID patchset.

v4 -> v5:
- Add change lists to the top of the commit messages.
- Add a header to zstd's moudle.c file.
- Clarify where zstd's dependencies are coming from.
- Add module.c to Makefile.util.def.
- Clarify some error logging.
- Explain why I changed lzo's include.

v5 -> v6:
- Formatting changes

v6 -> v7:
- 2 spaces for first indent, not 4.

Nick Terrell (2):
Import upstream zstd-1.3.6
btrfs: Add zstd support to grub btrfs

 Makefile.util.def                    |   11 +-
 grub-core/Makefile.core.def          |   17 +-
 grub-core/fs/btrfs.c                 |  119 +-
 grub-core/lib/zstd/bitstream.h       |  458 ++++
 grub-core/lib/zstd/compiler.h        |  133 ++
 grub-core/lib/zstd/cpu.h             |  215 ++
 grub-core/lib/zstd/debug.c           |   44 +
 grub-core/lib/zstd/debug.h           |  123 +
 grub-core/lib/zstd/entropy_common.c  |  236 ++
 grub-core/lib/zstd/error_private.c   |   48 +
 grub-core/lib/zstd/error_private.h   |   76 +
 grub-core/lib/zstd/fse.h             |  708 ++++++
 grub-core/lib/zstd/fse_decompress.c  |  309 +++
 grub-core/lib/zstd/huf.h             |  334 +++
 grub-core/lib/zstd/huf_decompress.c  | 1096 +++++++++
 grub-core/lib/zstd/mem.h             |  374 ++++
 grub-core/lib/zstd/module.c          |   21 +
 grub-core/lib/zstd/xxhash.c          |  876 ++++++++
 grub-core/lib/zstd/xxhash.h          |  305 +++
 grub-core/lib/zstd/zstd.h            | 1516 +++++++++++++
 grub-core/lib/zstd/zstd_common.c     |   81 +
 grub-core/lib/zstd/zstd_decompress.c | 3108 ++++++++++++++++++++++++++
 grub-core/lib/zstd/zstd_errors.h     |   92 +
 grub-core/lib/zstd/zstd_internal.h   |  257 +++
 tests/btrfs_test.in                  |    1 +
 tests/util/grub-fs-tester.in         |    2 +-
 26 files changed, 10556 insertions(+), 4 deletions(-)
 create mode 100644 grub-core/lib/zstd/bitstream.h
 create mode 100644 grub-core/lib/zstd/compiler.h
 create mode 100644 grub-core/lib/zstd/cpu.h
 create mode 100644 grub-core/lib/zstd/debug.c
 create mode 100644 grub-core/lib/zstd/debug.h
 create mode 100644 grub-core/lib/zstd/entropy_common.c
 create mode 100644 grub-core/lib/zstd/error_private.c
 create mode 100644 grub-core/lib/zstd/error_private.h
 create mode 100644 grub-core/lib/zstd/fse.h
 create mode 100644 grub-core/lib/zstd/fse_decompress.c
 create mode 100644 grub-core/lib/zstd/huf.h
 create mode 100644 grub-core/lib/zstd/huf_decompress.c
 create mode 100644 grub-core/lib/zstd/mem.h
 create mode 100644 grub-core/lib/zstd/module.c
 create mode 100644 grub-core/lib/zstd/xxhash.c
 create mode 100644 grub-core/lib/zstd/xxhash.h
 create mode 100644 grub-core/lib/zstd/zstd.h
 create mode 100644 grub-core/lib/zstd/zstd_common.c
 create mode 100644 grub-core/lib/zstd/zstd_decompress.c
 create mode 100644 grub-core/lib/zstd/zstd_errors.h
 create mode 100644 grub-core/lib/zstd/zstd_internal.h

--
2.17.1