[PATCH v4 0/2] btrfs: Add zstd support to grub btrfs

[Nick Terrell]

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.

The fist patch imports the files needed to support zstd decompression from
zstd-1.3.6 as-is. It is a very large patch. In case it doesn't make it,
I've included the commit hash and the script I used to download the files.

Upstream zstd commit hash: 4fa456d7f12f8b27bd3b2f5dfd4f46898cb31c24
Upstream zstd commit name: Merge pull request #1354 from facebook/dev

```
#!/bin/sh -e

curl -L -O 
https://github.com/facebook/zstd/releases/download/v1.3.6/zstd-1.3.6.tar.gz
curl -L -O 
https://github.com/facebook/zstd/releases/download/v1.3.6/zstd-1.3.6.tar.gz.sha256
sha256sum --check zstd-1.3.6.tar.gz.sha256
tar xzf zstd-1.3.6.tar.gz

SRC_LIB="zstd-1.3.6/lib"
DST_LIB="grub-core/lib/zstd"
rm -rf $DST_LIB
mkdir -p $DST_LIB
cp $SRC_LIB/zstd.h $DST_LIB/
cp $SRC_LIB/common/*.[hc] $DST_LIB/
cp $SRC_LIB/decompress/*.[hc] $DST_LIB/
rm $DST_LIB/{pool.[hc],threading.[hc]}
rm -rf zstd-1.3.6*
echo SUCCESS!
```

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.

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

 Makefile.util.def                    |   10 +-
 grub-core/Makefile.core.def          |   17 +-
 grub-core/fs/btrfs.c                 |  108 +-
 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          |    3 +
 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, 10526 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