[PATCH 5/5] LZ4 compression in ZFS

[Massimo Maggi]

IllumOS issue #3035 - original commit
a6f561b4aee75d0d028e7b36b151c8ed8a86bc76

Author:  Saso Kiselkov <address@hidden>
Ported-by: Massimo Maggi <address@hidden>
---
 Makefile.util.def           |   1 +
 grub-core/Makefile.core.def |   1 +
 grub-core/fs/zfs/zfs.c      |   7 +-
 grub-core/fs/zfs/zfs_lz4.c  | 321
++++++++++++++++++++++++++++++++++++++++++++
 include/grub/zfs/zio.h      |   1 +
 po/POTFILES.in              |   1 +
 6 files changed, 330 insertions(+), 2 deletions(-)
 create mode 100644 grub-core/fs/zfs/zfs_lz4.c

diff --git a/Makefile.util.def b/Makefile.util.def
index 3ee5e4e..3ab043a 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -96,6 +96,7 @@ library = {
   common = grub-core/fs/zfs/zfs.c;
   common = grub-core/fs/zfs/zfsinfo.c;
   common = grub-core/fs/zfs/zfs_lzjb.c;
+  common = grub-core/fs/zfs/zfs_lz4.c;
   common = grub-core/fs/zfs/zfs_sha256.c;
   common = grub-core/fs/zfs/zfs_fletcher.c;
   common = grub-core/lib/envblk.c;
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 4609a4b..94dc6c9 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1224,6 +1224,7 @@ module = {
   name = zfs;
   common = fs/zfs/zfs.c;
   common = fs/zfs/zfs_lzjb.c;
+  common = fs/zfs/zfs_lz4.c;
   common = fs/zfs/zfs_sha256.c;
   common = fs/zfs/zfs_fletcher.c;
 };
diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
index cf10534..aaf1af4 100644
--- a/grub-core/fs/zfs/zfs.c
+++ b/grub-core/fs/zfs/zfs.c
@@ -154,11 +154,13 @@ ZAP_LEAF_ENTRY(zap_leaf_phys_t *l, int bs, int idx)
   /*
- * Decompression Entry - lzjb
+ * Decompression Entry - lzjb & lz4
  */
  extern grub_err_t lzjb_decompress (void *, void *, grub_size_t,
grub_size_t);
 +extern grub_err_t lz4_decompress (void *, void *, grub_size_t,
grub_size_t);
+
 typedef grub_err_t zfs_decomp_func_t (void *s_start, void *d_start,
                                      grub_size_t s_len, grub_size_t d_len);
 typedef struct decomp_entry
@@ -278,7 +280,7 @@ grub_crypto_cipher_handle_t (*grub_zfs_load_key)
(const struct grub_zfs_key *key
  * to be listed here since grub opens pools in read-only mode.
  */
 static const char *spa_feature_names[] = {
-       "max.test:feat1",NULL
+       "org.illumos:lz4_compress",NULL
 };
  static int
@@ -344,6 +346,7 @@ static decomp_entry_t
decomp_table[ZIO_COMPRESS_FUNCTIONS] = {
   {"gzip-8", zlib_decompress},  /* ZIO_COMPRESS_GZIP8 */
   {"gzip-9", zlib_decompress},  /* ZIO_COMPRESS_GZIP9 */
   {"zle", zle_decompress},      /* ZIO_COMPRESS_ZLE   */
+  {"lz4", lz4_decompress},      /* ZIO_COMPRESS_LZ4   */
 };
  static grub_err_t zio_read_data (blkptr_t * bp, grub_zfs_endian_t endian,
diff --git a/grub-core/fs/zfs/zfs_lz4.c b/grub-core/fs/zfs/zfs_lz4.c
new file mode 100644
index 0000000..f199434
--- /dev/null
+++ b/grub-core/fs/zfs/zfs_lz4.c
@@ -0,0 +1,321 @@
+/*
+ * LZ4 - Fast LZ compression algorithm
+ * Header File
+ * Copyright (C) 2011-2013, 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://fastcompression.blogspot.com/p/lz4.html
+ * - LZ4 source repository : http://code.google.com/p/lz4/
+ */
+
+#include <grub/err.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/types.h>
+
+static int LZ4_uncompress_unknownOutputSize(const char *source, char *dest,
+                                           int isize, int maxOutputSize);
+
+/*
+ * CPU Feature Detection
+ */
+
+/* 32 or 64 bits ? */
+#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || \
+       defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || \
+       defined(__LP64__) || defined(_LP64))
+#define        LZ4_ARCH64      1
+#else
+#define        LZ4_ARCH64      0
+#endif
+
+/*
+ * Little Endian or Big Endian?
+ * Note: overwrite the below #define if you know your architecture
endianess.
+ */
+#if (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || \
+       defined(_BIG_ENDIAN) || defined(_ARCH_PPC) || defined(__PPC__) || \
+       defined(__PPC) || defined(PPC) || defined(__powerpc__) || \
+       defined(__powerpc) || defined(powerpc) || \
+       ((defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))))
+#define        LZ4_BIG_ENDIAN  1
+#else
+       /*
+        * Little Endian assumed. PDP Endian and other very rare endian format
+        * are unsupported.
+        */
+#endif
+
+/*
+ * Compiler Options
+ */
+
+#if __STDC_VERSION__ >= 199901L        /* C99 */
+/* "restrict" is a known keyword */
+#else
+/* Disable restrict */
+#ifndef restrict
+#define        restrict /* Only if somebody already didn't take care of that.*/
+#endif
+#endif
+
+#define        GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+#define        lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) \
+       | (((x) & 0xffu) << 8)))
+
+#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
+#define        expect(expr, value)    (__builtin_expect((expr), (value)))
+#else
+#define        expect(expr, value)    (expr)
+#endif
+
+#define        likely(expr)    expect((expr) != 0, 1)
+#define        unlikely(expr)  expect((expr) != 0, 0)
+
+/* Basic types */
+#define        BYTE    grub_uint8_t
+#define        U16     grub_uint16_t
+#define        U32     grub_uint32_t
+#define        S32     grub_int32_t
+#define        U64     grub_uint64_t
+typedef grub_size_t size_t;
+
+typedef struct _U16_S {
+       U16 v;
+} U16_S;
+typedef struct _U32_S {
+       U32 v;
+} U32_S;
+typedef struct _U64_S {
+       U64 v;
+} U64_S;
+
+#define        A64(x)  (((U64_S *)(x))->v)
+#define        A32(x)  (((U32_S *)(x))->v)
+#define        A16(x)  (((U16_S *)(x))->v)
+
+/*
+ * Constants
+ */
+#define        MINMATCH 4
+
+#define        COPYLENGTH 8
+#define        LASTLITERALS 5
+
+#define        ML_BITS 4
+#define        ML_MASK ((1U<<ML_BITS)-1)
+#define        RUN_BITS (8-ML_BITS)
+#define        RUN_MASK ((1U<<RUN_BITS)-1)
+
+/*
+ * Architecture-specific macros
+ */
+#if LZ4_ARCH64
+#define        STEPSIZE 8
+#define        UARCH U64
+#define        AARCH A64
+#define        LZ4_COPYSTEP(s, d)      A64(d) = A64(s); d += 8; s += 8;
+#define        LZ4_COPYPACKET(s, d)    LZ4_COPYSTEP(s, d)
+#define        LZ4_SECURECOPY(s, d, e) if (d < e) LZ4_WILDCOPY(s, d, e)
+#define        HTYPE U32
+#define        INITBASE(base)          const BYTE* const base = ip
+#else
+#define        STEPSIZE 4
+#define        UARCH U32
+#define        AARCH A32
+#define        LZ4_COPYSTEP(s, d)      A32(d) = A32(s); d += 4; s += 4;
+#define        LZ4_COPYPACKET(s, d)    LZ4_COPYSTEP(s, d); LZ4_COPYSTEP(s, d);
+#define        LZ4_SECURECOPY          LZ4_WILDCOPY
+#define        HTYPE const BYTE*
+#define        INITBASE(base)          const int base = 0
+#endif
+
+#if (defined(LZ4_BIG_ENDIAN) &&
!defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
+#define        LZ4_READ_LITTLEENDIAN_16(d, s, p) \
+       { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
+#define        LZ4_WRITE_LITTLEENDIAN_16(p, i) \
+       { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p += 2; }
+#else
+#define        LZ4_READ_LITTLEENDIAN_16(d, s, p) { d = (s) - A16(p); }
+#define        LZ4_WRITE_LITTLEENDIAN_16(p, v)  { A16(p) = v; p += 2; }
+#endif
+
+/* Macros */
+#define        LZ4_WILDCOPY(s, d, e) do { LZ4_COPYPACKET(s, d) } while (d < e);
+
+/* Decompression functions */
+grub_err_t
+lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len);
+
+grub_err_t
+lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len)
+{
+       const BYTE *src = s_start;
+       U32 bufsiz = (src[0] << 24) | (src[1] << 16) | (src[2] << 8) |
+           src[3];
+
+       /* invalid compressed buffer size encoded at start */
+       if (bufsiz + 4 > s_len)
+               return grub_error(GRUB_ERR_BAD_FS,"lz4 decompression failed.");
+
+       /*
+        * Returns 0 on success (decompression function returned non-negative)
+        * and appropriate error on failure (decompression function returned
negative).
+        */
+       return (LZ4_uncompress_unknownOutputSize((char*)s_start + 4, d_start,
bufsiz,
+           d_len) < 0)?grub_error(GRUB_ERR_BAD_FS,"lz4 decompression 
failed."):0;
+}
+
+static int
+LZ4_uncompress_unknownOutputSize(const char *source,
+    char *dest, int isize, int maxOutputSize)
+{
+       /* Local Variables */
+       const BYTE *restrict ip = (const BYTE *) source;
+       const BYTE *const iend = ip + isize;
+       const BYTE *restrict ref;
+
+       BYTE *restrict op = (BYTE *) dest;
+       BYTE *const oend = op + maxOutputSize;
+       BYTE *cpy;
+
+       size_t dec[] = { 0, 3, 2, 3, 0, 0, 0, 0 };
+
+       /* Main Loop */
+       while (ip < iend) {
+               BYTE token;
+               int length;
+
+               /* get runlength */
+               token = *ip++;
+               if ((length = (token >> ML_BITS)) == RUN_MASK) {
+                       int s = 255;
+                       while ((ip < iend) && (s == 255)) {
+                               s = *ip++;
+                               length += s;
+                       }
+               }
+               /* copy literals */
+               cpy = op + length;
+               if ((cpy > oend - COPYLENGTH) ||
+                   (ip + length > iend - COPYLENGTH)) {
+                       if (cpy > oend)
+                               /*
+                                * Error: request to write beyond destination
+                                * buffer.
+                                */
+                               goto _output_error;
+                       if (ip + length > iend)
+                               /*
+                                * Error : request to read beyond source
+                                * buffer.
+                                */
+                               goto _output_error;
+                       grub_memcpy(op, ip, length);
+                       op += length;
+                       ip += length;
+                       if (ip < iend)
+                               /* Error : LZ4 format violation */
+                               goto _output_error;
+                       /* Necessarily EOF, due to parsing restrictions. */
+                       break;
+               }
+               LZ4_WILDCOPY(ip, op, cpy);
+               ip -= (op - cpy);
+               op = cpy;
+
+               /* get offset */
+               LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip);
+               ip += 2;
+               if (ref < (BYTE * const) dest)
+                       /*
+                        * Error: offset creates reference outside of
+                        * destination buffer.
+                        */
+                       goto _output_error;
+
+               /* get matchlength */
+               if ((length = (token & ML_MASK)) == ML_MASK) {
+                       while (ip < iend) {
+                               int s = *ip++;
+                               length += s;
+                               if (s == 255)
+                                       continue;
+                               break;
+                       }
+               }
+               /* copy repeated sequence */
+               if unlikely(op - ref < STEPSIZE) {
+#if LZ4_ARCH64
+                       size_t dec2table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
+                       size_t dec2 = dec2table[op - ref];
+#else
+                       const int dec2 = 0;
+#endif
+                       *op++ = *ref++;
+                       *op++ = *ref++;
+                       *op++ = *ref++;
+                       *op++ = *ref++;
+                       ref -= dec[op - ref];
+                       A32(op) = A32(ref);
+                       op += STEPSIZE - 4;
+                       ref -= dec2;
+               } else {
+                       LZ4_COPYSTEP(ref, op);
+               }
+               cpy = op + length - (STEPSIZE - 4);
+               if (cpy > oend - COPYLENGTH) {
+                       if (cpy > oend)
+                               /*
+                                * Error: request to write outside of
+                                * destination buffer.
+                                */
+                               goto _output_error;
+                       LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
+                       while (op < cpy)
+                               *op++ = *ref++;
+                       op = cpy;
+                       if (op == oend)
+                               /*
+                                * Check EOF (should never happen, since last
+                                * 5 bytes are supposed to be literals).
+                                */
+                               break;
+                       continue;
+               }
+               LZ4_SECURECOPY(ref, op, cpy);
+               op = cpy;       /* correction */
+       }
+
+       /* end of decoding */
+       return (int)(((char *)op) - dest);
+
+       /* write overflow error detected */
+       _output_error:
+       return (int)(-(((char *)ip) - source));
+}
diff --git a/include/grub/zfs/zio.h b/include/grub/zfs/zio.h
index b1c46da..8fad2cc 100644
--- a/include/grub/zfs/zio.h
+++ b/include/grub/zfs/zio.h
@@ -88,6 +88,7 @@ enum zio_compress {
        ZIO_COMPRESS_GZIP8,
        ZIO_COMPRESS_GZIP9,
        ZIO_COMPRESS_ZLE,
+       ZIO_COMPRESS_LZ4,
        ZIO_COMPRESS_FUNCTIONS
 };
 diff --git a/po/POTFILES.in b/po/POTFILES.in
index 01cc53c..a0a5d60 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -174,6 +174,7 @@
 ./grub-core/fs/zfs/zfs_fletcher.c
 ./grub-core/fs/zfs/zfsinfo.c
 ./grub-core/fs/zfs/zfs_lzjb.c
+./grub-core/fs/zfs/zfs_lz4.c
 ./grub-core/fs/zfs/zfs_sha256.c
 ./grub-core/gdb/cstub.c
 ./grub-core/gdb/gdb.c
-- 
1.8.1.1

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