linux/lib/zstd/zstd_decompress_module.c
Nick Terrell 65d1f5507e zstd: Import upstream v1.5.7
In addition to keeping the kernel's copy of zstd up to date, this update
was requested by Intel to expose upstream's APIs that allow QAT to accelerate
the LZ match finding stage of Zstd.

This patch is imported from the upstream tag v1.5.7-kernel [0], which is signed
with upstream's signing key EF8FE99528B52FFD [1]. It was imported from upstream
using this command:

  export ZSTD=/path/to/repo/zstd/
  export LINUX=/path/to/repo/linux/
  cd "$ZSTD/contrib/linux-kernel"
  git checkout v1.5.7-kernel
  make import LINUX="$LINUX"

This patch has been tested on x86-64, and has been boot tested with
a zstd compressed kernel & initramfs on i386 and aarch64. I benchmarked
the patch on x86-64 with gcc-14.2.1 on an Intel i9-9900K by measruing the
performance of compressed filesystem reads and writes.

Component,  Level,  Size delta, C. time delta,  D. time delta
Btrfs    ,      1,      +0.00%,         -6.1%,          +1.4%
Btrfs    ,      3,      +0.00%,         -9.8%,          +3.0%
Btrfs    ,      5,      +0.00%,         +1.7%,          +1.4%
Btrfs    ,      7,      +0.00%,         -1.9%,          +2.7%
Btrfs    ,      9,      +0.00%,         -3.4%,          +3.7%
Btrfs    ,     15,      +0.00%,         -0.3%,          +3.6%
SquashFS ,      1,      +0.00%,           N/A,          +1.9%

The major changes that impact the kernel use cases for each version are:

v1.5.7: https://github.com/facebook/zstd/releases/tag/v1.5.7
* Add zstd_compress_sequences_and_literals() for use by Intel's QAT driver
  to implement Zstd compression acceleration in the kernel.
* Fix an underflow bug in 32-bit builds that can cause data corruption when
  processing more than 4GB of data with a single `ZSTD_CCtx` object, when an
  input crosses the 4GB boundry. I don't believe this impacts any current kernel
  use cases, because the `ZSTD_CCtx` is typically reconstructed between
  compressions.
* Levels 1-4 see 5-10% compression speed improvements for inputs smaller than
  128KB.

v1.5.6: https://github.com/facebook/zstd/releases/tag/v1.5.6
* Improved compression ratio for the highest compression levels. I don't expect
  these see much use however, due to their slow speeds.

v1.5.5: https://github.com/facebook/zstd/releases/tag/v1.5.5
* Fix a rare corruption bug that can trigger on levels 13 and above.
* Improve compression speed of levels 5-11 on incompressible data.

v1.5.4: https://github.com/facebook/zstd/releases/tag/v1.5.4
* Improve copmression speed of levels 5-11 on ARM.
* Improve dictionary compression speed.

Signed-off-by: Nick Terrell <terrelln@fb.com>
2025-03-13 13:25:58 -07:00

141 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/zstd.h>
#include "common/zstd_deps.h"
/* Common symbols. zstd_compress must depend on zstd_decompress. */
unsigned int zstd_is_error(size_t code)
{
return ZSTD_isError(code);
}
EXPORT_SYMBOL(zstd_is_error);
zstd_error_code zstd_get_error_code(size_t code)
{
return ZSTD_getErrorCode(code);
}
EXPORT_SYMBOL(zstd_get_error_code);
const char *zstd_get_error_name(size_t code)
{
return ZSTD_getErrorName(code);
}
EXPORT_SYMBOL(zstd_get_error_name);
/* Decompression symbols. */
size_t zstd_dctx_workspace_bound(void)
{
return ZSTD_estimateDCtxSize();
}
EXPORT_SYMBOL(zstd_dctx_workspace_bound);
zstd_dctx *zstd_create_dctx_advanced(zstd_custom_mem custom_mem)
{
return ZSTD_createDCtx_advanced(custom_mem);
}
EXPORT_SYMBOL(zstd_create_dctx_advanced);
size_t zstd_free_dctx(zstd_dctx *dctx)
{
return ZSTD_freeDCtx(dctx);
}
EXPORT_SYMBOL(zstd_free_dctx);
zstd_ddict *zstd_create_ddict_byreference(const void *dict, size_t dict_size,
zstd_custom_mem custom_mem)
{
return ZSTD_createDDict_advanced(dict, dict_size, ZSTD_dlm_byRef,
ZSTD_dct_auto, custom_mem);
}
EXPORT_SYMBOL(zstd_create_ddict_byreference);
size_t zstd_free_ddict(zstd_ddict *ddict)
{
return ZSTD_freeDDict(ddict);
}
EXPORT_SYMBOL(zstd_free_ddict);
zstd_dctx *zstd_init_dctx(void *workspace, size_t workspace_size)
{
if (workspace == NULL)
return NULL;
return ZSTD_initStaticDCtx(workspace, workspace_size);
}
EXPORT_SYMBOL(zstd_init_dctx);
size_t zstd_decompress_dctx(zstd_dctx *dctx, void *dst, size_t dst_capacity,
const void *src, size_t src_size)
{
return ZSTD_decompressDCtx(dctx, dst, dst_capacity, src, src_size);
}
EXPORT_SYMBOL(zstd_decompress_dctx);
size_t zstd_decompress_using_ddict(zstd_dctx *dctx,
void *dst, size_t dst_capacity, const void* src, size_t src_size,
const zstd_ddict* ddict)
{
return ZSTD_decompress_usingDDict(dctx, dst, dst_capacity, src,
src_size, ddict);
}
EXPORT_SYMBOL(zstd_decompress_using_ddict);
size_t zstd_dstream_workspace_bound(size_t max_window_size)
{
return ZSTD_estimateDStreamSize(max_window_size);
}
EXPORT_SYMBOL(zstd_dstream_workspace_bound);
zstd_dstream *zstd_init_dstream(size_t max_window_size, void *workspace,
size_t workspace_size)
{
if (workspace == NULL)
return NULL;
(void)max_window_size;
return ZSTD_initStaticDStream(workspace, workspace_size);
}
EXPORT_SYMBOL(zstd_init_dstream);
size_t zstd_reset_dstream(zstd_dstream *dstream)
{
return ZSTD_DCtx_reset(dstream, ZSTD_reset_session_only);
}
EXPORT_SYMBOL(zstd_reset_dstream);
size_t zstd_decompress_stream(zstd_dstream *dstream, zstd_out_buffer *output,
zstd_in_buffer *input)
{
return ZSTD_decompressStream(dstream, output, input);
}
EXPORT_SYMBOL(zstd_decompress_stream);
size_t zstd_find_frame_compressed_size(const void *src, size_t src_size)
{
return ZSTD_findFrameCompressedSize(src, src_size);
}
EXPORT_SYMBOL(zstd_find_frame_compressed_size);
size_t zstd_get_frame_header(zstd_frame_header *header, const void *src,
size_t src_size)
{
return ZSTD_getFrameHeader(header, src, src_size);
}
EXPORT_SYMBOL(zstd_get_frame_header);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Zstd Decompressor");