Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull zstd support from Chris Mason:
 "Nick Terrell's patch series to add zstd support to the kernel has been
  floating around for a while. After talking with Dave Sterba, Herbert
  and Phillip, we decided to send the whole thing in as one pull
  request.

  zstd is a big win in speed over zlib and in compression ratio over
  lzo, and the compression team here at FB has gotten great results
  using it in production. Nick will continue to update the kernel side
  with new improvements from the open source zstd userland code.

  Nick has a number of benchmarks for the main zstd code in his lib/zstd
  commit:

      I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB
      of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel
      Core i7 processor, 16 GB of RAM, and a SSD. I benchmarked using
      `silesia.tar` [3], which is 211,988,480 B large. Run the following
      commands for the benchmark:

        sudo modprobe zstd_compress_test
        sudo mknod zstd_compress_test c 245 0
        sudo cp silesia.tar zstd_compress_test

      The time is reported by the time of the userland `cp`.
      The MB/s is computed with

        1,536,217,008 B / time(buffer size, hash)

      which includes the time to copy from userland.
      The Adjusted MB/s is computed with

        1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

      The memory reported is the amount of memory the compressor
      requests.

        | Method   | Size (B) | Time (s) | Ratio | MB/s    | Adj MB/s | Mem (MB) |
        |----------|----------|----------|-------|---------|----------|----------|
        | none     | 11988480 |    0.100 |     1 | 2119.88 |        - |        - |
        | zstd -1  | 73645762 |    1.044 | 2.878 |  203.05 |   224.56 |     1.23 |
        | zstd -3  | 66988878 |    1.761 | 3.165 |  120.38 |   127.63 |     2.47 |
        | zstd -5  | 65001259 |    2.563 | 3.261 |   82.71 |    86.07 |     2.86 |
        | zstd -10 | 60165346 |   13.242 | 3.523 |   16.01 |    16.13 |    13.22 |
        | zstd -15 | 58009756 |   47.601 | 3.654 |    4.45 |     4.46 |    21.61 |
        | zstd -19 | 54014593 |  102.835 | 3.925 |    2.06 |     2.06 |    60.15 |
        | zlib -1  | 77260026 |    2.895 | 2.744 |   73.23 |    75.85 |     0.27 |
        | zlib -3  | 72972206 |    4.116 | 2.905 |   51.50 |    52.79 |     0.27 |
        | zlib -6  | 68190360 |    9.633 | 3.109 |   22.01 |    22.24 |     0.27 |
        | zlib -9  | 67613382 |   22.554 | 3.135 |    9.40 |     9.44 |     0.27 |

      I benchmarked zstd decompression using the same method on the same
      machine. The benchmark file is located in the upstream zstd repo
      under `contrib/linux-kernel/zstd_decompress_test.c` [4]. The
      memory reported is the amount of memory required to decompress
      data compressed with the given compression level. If you know the
      maximum size of your input, you can reduce the memory usage of
      decompression irrespective of the compression level.

        | Method   | Time (s) | MB/s    | Adjusted MB/s | Memory (MB) |
        |----------|----------|---------|---------------|-------------|
        | none     |    0.025 | 8479.54 |             - |           - |
        | zstd -1  |    0.358 |  592.15 |        636.60 |        0.84 |
        | zstd -3  |    0.396 |  535.32 |        571.40 |        1.46 |
        | zstd -5  |    0.396 |  535.32 |        571.40 |        1.46 |
        | zstd -10 |    0.374 |  566.81 |        607.42 |        2.51 |
        | zstd -15 |    0.379 |  559.34 |        598.84 |        4.61 |
        | zstd -19 |    0.412 |  514.54 |        547.77 |        8.80 |
        | zlib -1  |    0.940 |  225.52 |        231.68 |        0.04 |
        | zlib -3  |    0.883 |  240.08 |        247.07 |        0.04 |
        | zlib -6  |    0.844 |  251.17 |        258.84 |        0.04 |
        | zlib -9  |    0.837 |  253.27 |        287.64 |        0.04 |

  I ran a long series of tests and benchmarks on the btrfs side and the
  gains are very similar to the core benchmarks Nick ran"

* 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  squashfs: Add zstd support
  btrfs: Add zstd support
  lib: Add zstd modules
  lib: Add xxhash module

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/zstd/error_private.h b/lib/zstd/error_private.h
new file mode 100644
index 000000000000..1a60b31f706c
--- /dev/null
+++ b/lib/zstd/error_private.h
@@ -0,0 +1,53 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of https://github.com/facebook/zstd.
+ * An additional grant of patent rights can be found in the PATENTS file in the
+ * same directory.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ */
+
+/* Note : this module is expected to remain private, do not expose it */
+
+#ifndef ERROR_H_MODULE
+#define ERROR_H_MODULE
+
+/* ****************************************
+*  Dependencies
+******************************************/
+#include <linux/types.h> /* size_t */
+#include <linux/zstd.h>  /* enum list */
+
+/* ****************************************
+*  Compiler-specific
+******************************************/
+#define ERR_STATIC static __attribute__((unused))
+
+/*-****************************************
+*  Customization (error_public.h)
+******************************************/
+typedef ZSTD_ErrorCode ERR_enum;
+#define PREFIX(name) ZSTD_error_##name
+
+/*-****************************************
+*  Error codes handling
+******************************************/
+#define ERROR(name) ((size_t)-PREFIX(name))
+
+ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
+
+ERR_STATIC ERR_enum ERR_getErrorCode(size_t code)
+{
+	if (!ERR_isError(code))
+		return (ERR_enum)0;
+	return (ERR_enum)(0 - code);
+}
+
+#endif /* ERROR_H_MODULE */