target/linux/generic/patches-2.6.36/006-squashfs_add_lzma.patch

   1 From f49e1efdd179d54e814ff2a8e8f469496583062c Mon Sep 17 00:00:00 2001
   2 From: Phillip Lougher <phillip@lougher.demon.co.uk>
   3 Date: Tue, 20 Oct 2009 10:54:36 +0100
   4 Subject: [PATCH] Squashfs: add LZMA compression
   5
   6 Add support for LZMA compressed filesystems.  This is an initial
   7 implementation.
   8
   9 Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
  10 ---
  11  fs/squashfs/Kconfig        |    5 ++
  12  fs/squashfs/Makefile       |    1 +
  13  fs/squashfs/decompressor.c |    4 +
  14  fs/squashfs/lzma_wrapper.c |  151 ++++++++++++++++++++++++++++++++++++++++++++
  15  fs/squashfs/squashfs.h     |    3 +
  16  5 files changed, 164 insertions(+), 0 deletions(-)
  17  create mode 100644 fs/squashfs/lzma_wrapper.c
  18
  19 --- a/fs/squashfs/Kconfig
  20 +++ b/fs/squashfs/Kconfig
  21 @@ -37,6 +37,11 @@ config SQUASHFS_XATTRS
  22
  23           If unsure, say N.
  24
  25 +config SQUASHFS_LZMA
  26 +       bool "Include support for LZMA compressed file systems"
  27 +       depends on SQUASHFS
  28 +       select DECOMPRESS_LZMA
  29 +
  30  config SQUASHFS_EMBEDDED
  31
  32         bool "Additional option for memory-constrained systems"
  33 --- a/fs/squashfs/Makefile
  34 +++ b/fs/squashfs/Makefile
  35 @@ -5,5 +5,4 @@
  36  obj-$(CONFIG_SQUASHFS) += squashfs.o
  37  squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
  38  squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
  39 -squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
  40 -squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
  41 +squashfs-$(CONFIG_SQUASHFS_LZMA) += lzma_wrapper.o
  42 --- a/fs/squashfs/decompressor.c
  43 +++ b/fs/squashfs/decompressor.c
  44 @@ -53,8 +53,8 @@ static const struct squashfs_decompresso
  45  static const struct squashfs_decompressor *decompressor[] = {
  46         &squashfs_zlib_comp_ops,
  47         &squashfs_lzma_unsupported_comp_ops,
  48 -#ifdef CONFIG_SQUASHFS_LZO
  49 -       &squashfs_lzo_comp_ops,
  50 +#ifdef CONFIG_SQUASHFS_LZMA
  51 +       &squashfs_lzma_comp_ops,
  52  #else
  53         &squashfs_lzo_unsupported_comp_ops,
  54  #endif
  55 --- /dev/null
  56 +++ b/fs/squashfs/lzma_wrapper.c
  57 @@ -0,0 +1,152 @@
  58 +/*
  59 + * Squashfs - a compressed read only filesystem for Linux
  60 + *
  61 + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
  62 + * Phillip Lougher <phillip@lougher.demon.co.uk>
  63 + *
  64 + * This program is free software; you can redistribute it and/or
  65 + * modify it under the terms of the GNU General Public License
  66 + * as published by the Free Software Foundation; either version 2,
  67 + * or (at your option) any later version.
  68 + *
  69 + * This program is distributed in the hope that it will be useful,
  70 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  71 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  72 + * GNU General Public License for more details.
  73 + *
  74 + * You should have received a copy of the GNU General Public License
  75 + * along with this program; if not, write to the Free Software
  76 + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  77 + *
  78 + * lzma_wrapper.c
  79 + */
  80 +
  81 +#include <asm/unaligned.h>
  82 +#include <linux/buffer_head.h>
  83 +#include <linux/mutex.h>
  84 +#include <linux/vmalloc.h>
  85 +#include <linux/decompress/unlzma.h>
  86 +#include <linux/slab.h>
  87 +
  88 +#include "squashfs_fs.h"
  89 +#include "squashfs_fs_sb.h"
  90 +#include "squashfs_fs_i.h"
  91 +#include "squashfs.h"
  92 +#include "decompressor.h"
  93 +
  94 +struct squashfs_lzma {
  95 +       void    *input;
  96 +       void    *output;
  97 +};
  98 +
  99 +/* decompress_unlzma.c is currently non re-entrant... */
 100 +DEFINE_MUTEX(lzma_mutex);
 101 +
 102 +/* decompress_unlzma.c doesn't provide any context in its callbacks... */
 103 +static int lzma_error;
 104 +
 105 +static void error(char *m)
 106 +{
 107 +       ERROR("unlzma error: %s\n", m);
 108 +       lzma_error = 1;
 109 +}
 110 +
 111 +
 112 +static void *lzma_init(struct squashfs_sb_info *msblk)
 113 +{
 114 +       struct squashfs_lzma *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
 115 +       if (stream == NULL)
 116 +               goto failed;
 117 +       stream->input = vmalloc(msblk->block_size);
 118 +       if (stream->input == NULL)
 119 +               goto failed;
 120 +       stream->output = vmalloc(msblk->block_size);
 121 +       if (stream->output == NULL)
 122 +               goto failed2;
 123 +
 124 +       return stream;
 125 +
 126 +failed2:
 127 +       vfree(stream->input);
 128 +failed:
 129 +       ERROR("failed to allocate lzma workspace\n");
 130 +       kfree(stream);
 131 +       return NULL;
 132 +}
 133 +
 134 +
 135 +static void lzma_free(void *strm)
 136 +{
 137 +       struct squashfs_lzma *stream = strm;
 138 +
 139 +       if (stream) {
 140 +               vfree(stream->input);
 141 +               vfree(stream->output);
 142 +       }
 143 +       kfree(stream);
 144 +}
 145 +
 146 +
 147 +static int lzma_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 148 +       struct buffer_head **bh, int b, int offset, int length, int srclength,
 149 +       int pages)
 150 +{
 151 +       struct squashfs_lzma *stream = msblk->stream;
 152 +       void *buff = stream->input;
 153 +       int avail, i, bytes = length, res;
 154 +
 155 +       mutex_lock(&lzma_mutex);
 156 +
 157 +       for (i = 0; i < b; i++) {
 158 +               wait_on_buffer(bh[i]);
 159 +               if (!buffer_uptodate(bh[i]))
 160 +                       goto block_release;
 161 +
 162 +               avail = min(bytes, msblk->devblksize - offset);
 163 +               memcpy(buff, bh[i]->b_data + offset, avail);
 164 +               buff += avail;
 165 +               bytes -= avail;
 166 +               offset = 0;
 167 +               put_bh(bh[i]);
 168 +       }
 169 +
 170 +       lzma_error = 0;
 171 +       res = unlzma(stream->input, length, NULL, NULL, stream->output, NULL,
 172 +                                                       error);
 173 +       if (res || lzma_error)
 174 +               goto failed;
 175 +
 176 +       /* uncompressed size is stored in the LZMA header (5 byte offset) */
 177 +       res = bytes = get_unaligned_le32(stream->input + 5);
 178 +       for (i = 0, buff = stream->output; bytes && i < pages; i++) {
 179 +               avail = min_t(int, bytes, PAGE_CACHE_SIZE);
 180 +               memcpy(buffer[i], buff, avail);
 181 +               buff += avail;
 182 +               bytes -= avail;
 183 +       }
 184 +       if (bytes)
 185 +               goto failed;
 186 +
 187 +       mutex_unlock(&lzma_mutex);
 188 +       return res;
 189 +
 190 +block_release:
 191 +       for (; i < b; i++)
 192 +               put_bh(bh[i]);
 193 +
 194 +failed:
 195 +       mutex_unlock(&lzma_mutex);
 196 +
 197 +       ERROR("lzma decompression failed, data probably corrupt\n");
 198 +       return -EIO;
 199 +}
 200 +
 201 +const struct squashfs_decompressor squashfs_lzma_comp_ops = {
 202 +       .init = lzma_init,
 203 +       .free = lzma_free,
 204 +       .decompress = lzma_uncompress,
 205 +       .id = LZMA_COMPRESSION,
 206 +       .name = "lzma",
 207 +       .supported = 1
 208 +};
 209 +
 210 --- a/fs/squashfs/squashfs.h
 211 +++ b/fs/squashfs/squashfs.h
 212 @@ -105,5 +105,5 @@ extern const struct xattr_handler *squas
 213  /* zlib_wrapper.c */
 214  extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
 215
 216 -/* lzo_wrapper.c */
 217 -extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
 218 +/* lzma_wrapper.c */
 219 +extern const struct squashfs_decompressor squashfs_lzma_comp_ops;