[PATCH] staging: erofs: use the new LZ4_decompress_safe_partial()

From: Gao Xiang
Date: Wed Nov 07 2018 - 22:46:37 EST


LZ4_decompress_safe_partial() can now decode exactly the nb of bytes
requested after the upstreamed commit 2209fda323e2 ("lib/lz4: update LZ4
decompressor module"), remove the erofs hacked lz4 decompression code.

A more cleaned compressor wrapper will be introduced in the subsequent
patches in order to prepare for supporting multiple compression algorithms.

Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
---

Hi Chao,
Could you please kindly confirm (review) this before merging into the staging tree?

Thanks,
Gao Xiang

drivers/staging/erofs/Makefile | 2 +-
drivers/staging/erofs/lz4defs.h | 227 ------------------------------
drivers/staging/erofs/unzip_lz4.c | 251 ----------------------------------
drivers/staging/erofs/unzip_vle_lz4.c | 25 +++-
4 files changed, 24 insertions(+), 481 deletions(-)
delete mode 100644 drivers/staging/erofs/lz4defs.h
delete mode 100644 drivers/staging/erofs/unzip_lz4.c

diff --git a/drivers/staging/erofs/Makefile b/drivers/staging/erofs/Makefile
index 9a766eb7ed75..c91b65223f99 100644
--- a/drivers/staging/erofs/Makefile
+++ b/drivers/staging/erofs/Makefile
@@ -9,5 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
ccflags-y += -I$(src)/include
erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
-erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o unzip_vle_lz4.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_vle_lz4.o

diff --git a/drivers/staging/erofs/lz4defs.h b/drivers/staging/erofs/lz4defs.h
deleted file mode 100644
index 00a0b58a0871..000000000000
--- a/drivers/staging/erofs/lz4defs.h
+++ /dev/null
@@ -1,227 +0,0 @@
-#ifndef __LZ4DEFS_H__
-#define __LZ4DEFS_H__
-
-/*
- * lz4defs.h -- common and architecture specific defines for the kernel usage
-
- * LZ4 - Fast LZ compression algorithm
- * Copyright (C) 2011-2016, Yann Collet.
- * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- * You can contact the author at :
- * - LZ4 homepage : http://www.lz4.org
- * - LZ4 source repository : https://github.com/lz4/lz4
- *
- * Changed for kernel usage by:
- * Sven Schmidt <4sschmid@xxxxxxxxxxxxxxxxxxxxxxxxx>
- */
-
-#include <asm/unaligned.h>
-#include <linux/string.h> /* memset, memcpy */
-
-#define FORCE_INLINE __always_inline
-
-/*-************************************
- * Basic Types
- **************************************/
-#include <linux/types.h>
-
-typedef uint8_t BYTE;
-typedef uint16_t U16;
-typedef uint32_t U32;
-typedef int32_t S32;
-typedef uint64_t U64;
-typedef uintptr_t uptrval;
-
-/*-************************************
- * Architecture specifics
- **************************************/
-#if defined(CONFIG_64BIT)
-#define LZ4_ARCH64 1
-#else
-#define LZ4_ARCH64 0
-#endif
-
-#if defined(__LITTLE_ENDIAN)
-#define LZ4_LITTLE_ENDIAN 1
-#else
-#define LZ4_LITTLE_ENDIAN 0
-#endif
-
-/*-************************************
- * Constants
- **************************************/
-#define MINMATCH 4
-
-#define WILDCOPYLENGTH 8
-#define LASTLITERALS 5
-#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
-
-/* Increase this value ==> compression run slower on incompressible data */
-#define LZ4_SKIPTRIGGER 6
-
-#define HASH_UNIT sizeof(size_t)
-
-#define KB (1 << 10)
-#define MB (1 << 20)
-#define GB (1U << 30)
-
-#define MAXD_LOG 16
-#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
-#define STEPSIZE sizeof(size_t)
-
-#define ML_BITS 4
-#define ML_MASK ((1U << ML_BITS) - 1)
-#define RUN_BITS (8 - ML_BITS)
-#define RUN_MASK ((1U << RUN_BITS) - 1)
-
-/*-************************************
- * Reading and writing into memory
- **************************************/
-static FORCE_INLINE U16 LZ4_read16(const void *ptr)
-{
- return get_unaligned((const U16 *)ptr);
-}
-
-static FORCE_INLINE U32 LZ4_read32(const void *ptr)
-{
- return get_unaligned((const U32 *)ptr);
-}
-
-static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
-{
- return get_unaligned((const size_t *)ptr);
-}
-
-static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
-{
- put_unaligned(value, (U16 *)memPtr);
-}
-
-static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
-{
- put_unaligned(value, (U32 *)memPtr);
-}
-
-static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
-{
- return get_unaligned_le16(memPtr);
-}
-
-static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
-{
- return put_unaligned_le16(value, memPtr);
-}
-
-static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
-{
-#if LZ4_ARCH64
- U64 a = get_unaligned((const U64 *)src);
-
- put_unaligned(a, (U64 *)dst);
-#else
- U32 a = get_unaligned((const U32 *)src);
- U32 b = get_unaligned((const U32 *)src + 1);
-
- put_unaligned(a, (U32 *)dst);
- put_unaligned(b, (U32 *)dst + 1);
-#endif
-}
-
-/*
- * customized variant of memcpy,
- * which can overwrite up to 7 bytes beyond dstEnd
- */
-static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
- const void *srcPtr, void *dstEnd)
-{
- BYTE *d = (BYTE *)dstPtr;
- const BYTE *s = (const BYTE *)srcPtr;
- BYTE *const e = (BYTE *)dstEnd;
-
- do {
- LZ4_copy8(d, s);
- d += 8;
- s += 8;
- } while (d < e);
-}
-
-static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
-{
-#if LZ4_LITTLE_ENDIAN
- return __ffs(val) >> 3;
-#else
- return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
-#endif
-}
-
-static FORCE_INLINE unsigned int LZ4_count(
- const BYTE *pIn,
- const BYTE *pMatch,
- const BYTE *pInLimit)
-{
- const BYTE *const pStart = pIn;
-
- while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
- size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
-
- if (!diff) {
- pIn += STEPSIZE;
- pMatch += STEPSIZE;
- continue;
- }
-
- pIn += LZ4_NbCommonBytes(diff);
-
- return (unsigned int)(pIn - pStart);
- }
-
-#if LZ4_ARCH64
- if ((pIn < (pInLimit - 3))
- && (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
- pIn += 4;
- pMatch += 4;
- }
-#endif
-
- if ((pIn < (pInLimit - 1))
- && (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
- pIn += 2;
- pMatch += 2;
- }
-
- if ((pIn < pInLimit) && (*pMatch == *pIn))
- pIn++;
-
- return (unsigned int)(pIn - pStart);
-}
-
-typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
-typedef enum { byPtr, byU32, byU16 } tableType_t;
-
-typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
-typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
-
-typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
-typedef enum { full = 0, partial = 1 } earlyEnd_directive;
-
-#endif
diff --git a/drivers/staging/erofs/unzip_lz4.c b/drivers/staging/erofs/unzip_lz4.c
deleted file mode 100644
index b1ea23f66c4e..000000000000
--- a/drivers/staging/erofs/unzip_lz4.c
+++ /dev/null
@@ -1,251 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
-/*
- * linux/drivers/staging/erofs/unzip_lz4.c
- *
- * Copyright (C) 2018 HUAWEI, Inc.
- * http://www.huawei.com/
- * Created by Gao Xiang <gaoxiang25@xxxxxxxxxx>
- *
- * Original code taken from 'linux/lib/lz4/lz4_decompress.c'
- */
-
-/*
- * LZ4 - Fast LZ compression algorithm
- * Copyright (C) 2011 - 2016, Yann Collet.
- * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- * You can contact the author at :
- * - LZ4 homepage : http://www.lz4.org
- * - LZ4 source repository : https://github.com/lz4/lz4
- *
- * Changed for kernel usage by:
- * Sven Schmidt <4sschmid@xxxxxxxxxxxxxxxxxxxxxxxxx>
- */
-#include "internal.h"
-#include <asm/unaligned.h>
-#include "lz4defs.h"
-
-/*
- * no public solution to solve our requirement yet.
- * see: <required buffer size for LZ4_decompress_safe_partial>
- * https://groups.google.com/forum/#!topic/lz4c/_3kkz5N6n00
- */
-static FORCE_INLINE int customized_lz4_decompress_safe_partial(
- const void * const source,
- void * const dest,
- int inputSize,
- int outputSize)
-{
- /* Local Variables */
- const BYTE *ip = (const BYTE *) source;
- const BYTE * const iend = ip + inputSize;
-
- BYTE *op = (BYTE *) dest;
- BYTE * const oend = op + outputSize;
- BYTE *cpy;
-
- static const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
- static const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
-
- /* Empty output buffer */
- if (unlikely(outputSize == 0))
- return ((inputSize == 1) && (*ip == 0)) ? 0 : -1;
-
- /* Main Loop : decode sequences */
- while (1) {
- size_t length;
- const BYTE *match;
- size_t offset;
-
- /* get literal length */
- unsigned int const token = *ip++;
-
- length = token>>ML_BITS;
-
- if (length == RUN_MASK) {
- unsigned int s;
-
- do {
- s = *ip++;
- length += s;
- } while ((ip < iend - RUN_MASK) & (s == 255));
-
- if (unlikely((size_t)(op + length) < (size_t)(op))) {
- /* overflow detection */
- goto _output_error;
- }
- if (unlikely((size_t)(ip + length) < (size_t)(ip))) {
- /* overflow detection */
- goto _output_error;
- }
- }
-
- /* copy literals */
- cpy = op + length;
- if ((cpy > oend - WILDCOPYLENGTH) ||
- (ip + length > iend - (2 + 1 + LASTLITERALS))) {
- if (cpy > oend) {
- memcpy(op, ip, length = oend - op);
- op += length;
- break;
- }
-
- if (unlikely(ip + length > iend)) {
- /*
- * Error :
- * read attempt beyond
- * end of input buffer
- */
- goto _output_error;
- }
-
- memcpy(op, ip, length);
- ip += length;
- op += length;
-
- if (ip > iend - 2)
- break;
- /* Necessarily EOF, due to parsing restrictions */
- /* break; */
- } else {
- LZ4_wildCopy(op, ip, cpy);
- ip += length;
- op = cpy;
- }
-
- /* get offset */
- offset = LZ4_readLE16(ip);
- ip += 2;
- match = op - offset;
-
- if (unlikely(match < (const BYTE *)dest)) {
- /* Error : offset outside buffers */
- goto _output_error;
- }
-
- /* get matchlength */
- length = token & ML_MASK;
- if (length == ML_MASK) {
- unsigned int s;
-
- do {
- s = *ip++;
-
- if (ip > iend - LASTLITERALS)
- goto _output_error;
-
- length += s;
- } while (s == 255);
-
- if (unlikely((size_t)(op + length) < (size_t)op)) {
- /* overflow detection */
- goto _output_error;
- }
- }
-
- length += MINMATCH;
-
- /* copy match within block */
- cpy = op + length;
-
- if (unlikely(cpy >= oend - WILDCOPYLENGTH)) {
- if (cpy >= oend) {
- while (op < oend)
- *op++ = *match++;
- break;
- }
- goto __match;
- }
-
- /* costs ~1%; silence an msan warning when offset == 0 */
- LZ4_write32(op, (U32)offset);
-
- if (unlikely(offset < 8)) {
- const int dec64 = dec64table[offset];
-
- op[0] = match[0];
- op[1] = match[1];
- op[2] = match[2];
- op[3] = match[3];
- match += dec32table[offset];
- memcpy(op + 4, match, 4);
- match -= dec64;
- } else {
- LZ4_copy8(op, match);
- match += 8;
- }
-
- op += 8;
-
- if (unlikely(cpy > oend - 12)) {
- BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
-
- if (op < oCopyLimit) {
- LZ4_wildCopy(op, match, oCopyLimit);
- match += oCopyLimit - op;
- op = oCopyLimit;
- }
-__match:
- while (op < cpy)
- *op++ = *match++;
- } else {
- LZ4_copy8(op, match);
-
- if (length > 16)
- LZ4_wildCopy(op + 8, match + 8, cpy);
- }
-
- op = cpy; /* correction */
- }
- DBG_BUGON((void *)ip - source > inputSize);
- DBG_BUGON((void *)op - dest > outputSize);
-
- /* Nb of output bytes decoded */
- return (int) ((void *)op - dest);
-
- /* Overflow error detected */
-_output_error:
- return -ERANGE;
-}
-
-int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen)
-{
- int ret = customized_lz4_decompress_safe_partial(in,
- out, inlen, outlen);
-
- if (ret >= 0)
- return ret;
-
- /*
- * LZ4_decompress_safe will return an error code
- * (< 0) if decompression failed
- */
- errln("%s, failed to decompress, in[%p, %zu] outlen[%p, %zu]",
- __func__, in, inlen, out, outlen);
- WARN_ON(1);
- print_hex_dump(KERN_DEBUG, "raw data [in]: ", DUMP_PREFIX_OFFSET,
- 16, 1, in, inlen, true);
- print_hex_dump(KERN_DEBUG, "raw data [out]: ", DUMP_PREFIX_OFFSET,
- 16, 1, out, outlen, true);
- return -EIO;
-}
-
diff --git a/drivers/staging/erofs/unzip_vle_lz4.c b/drivers/staging/erofs/unzip_vle_lz4.c
index 1a428658cbea..de0a5d1365a4 100644
--- a/drivers/staging/erofs/unzip_vle_lz4.c
+++ b/drivers/staging/erofs/unzip_vle_lz4.c
@@ -11,6 +11,28 @@
* distribution for more details.
*/
#include "unzip_vle.h"
+#include <linux/lz4.h>
+
+int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen)
+{
+ int ret = LZ4_decompress_safe_partial(in, out, inlen, outlen, outlen);
+
+ if (ret >= 0)
+ return ret;
+
+ /*
+ * LZ4_decompress_safe_partial will return an error code
+ * (< 0) if decompression failed
+ */
+ errln("%s, failed to decompress, in[%p, %zu] outlen[%p, %zu]",
+ __func__, in, inlen, out, outlen);
+ WARN_ON(1);
+ print_hex_dump(KERN_DEBUG, "raw data [in]: ", DUMP_PREFIX_OFFSET,
+ 16, 1, in, inlen, true);
+ print_hex_dump(KERN_DEBUG, "raw data [out]: ", DUMP_PREFIX_OFFSET,
+ 16, 1, out, outlen, true);
+ return -EIO;
+}

#if Z_EROFS_CLUSTER_MAX_PAGES > Z_EROFS_VLE_INLINE_PAGEVECS
#define EROFS_PERCPU_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
@@ -99,8 +121,6 @@ int z_erofs_vle_plain_copy(struct page **compressed_pages,
return 0;
}

-extern int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen);
-
int z_erofs_vle_unzip_fast_percpu(struct page **compressed_pages,
unsigned int clusterpages,
struct page **pages,
@@ -206,3 +226,4 @@ int z_erofs_vle_unzip_vmap(struct page **compressed_pages,
}
return ret;
}
+
--
2.14.4