1 | /* |
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2 | * JFFS2 -- Journalling Flash File System, Version 2. |
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3 | * |
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4 | * Copyright © 2001-2007 Red Hat, Inc. |
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5 | * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
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6 | * |
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7 | * Created by David Woodhouse <dwmw2@infradead.org> |
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8 | * |
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9 | * For licensing information, see the file 'LICENCE' in this directory. |
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10 | * |
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11 | */ |
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12 | |
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13 | #if !defined(__KERNEL__) && !defined(__ECOS) |
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14 | #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" |
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15 | #endif |
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16 | |
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17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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18 | |
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19 | #include <linux/kernel.h> |
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20 | #include <linux/zlib.h> |
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21 | #include <linux/zutil.h> |
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22 | #include "nodelist.h" |
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23 | #include "compr.h" |
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24 | |
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25 | /* Plan: call deflate() with avail_in == *sourcelen, |
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26 | avail_out = *dstlen - 12 and flush == Z_FINISH. |
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27 | If it doesn't manage to finish, call it again with |
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28 | avail_in == 0 and avail_out set to the remaining 12 |
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29 | bytes for it to clean up. |
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30 | Q: Is 12 bytes sufficient? |
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31 | */ |
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32 | #define STREAM_END_SPACE 12 |
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33 | |
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34 | static DEFINE_MUTEX(deflate_mutex); |
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35 | static DEFINE_MUTEX(inflate_mutex); |
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36 | static z_stream inf_strm, def_strm; |
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37 | |
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38 | #ifdef __KERNEL__ /* Linux-only */ |
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39 | #include <linux/vmalloc.h> |
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40 | #include <linux/init.h> |
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41 | #include <linux/mutex.h> |
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42 | |
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43 | static int __init alloc_workspaces(void) |
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44 | { |
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45 | def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, |
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46 | MAX_MEM_LEVEL)); |
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47 | if (!def_strm.workspace) |
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48 | return -ENOMEM; |
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49 | |
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50 | jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", |
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51 | zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); |
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52 | inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); |
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53 | if (!inf_strm.workspace) { |
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54 | vfree(def_strm.workspace); |
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55 | return -ENOMEM; |
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56 | } |
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57 | jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", |
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58 | zlib_inflate_workspacesize()); |
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59 | return 0; |
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60 | } |
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61 | |
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62 | static void free_workspaces(void) |
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63 | { |
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64 | vfree(def_strm.workspace); |
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65 | vfree(inf_strm.workspace); |
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66 | } |
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67 | #else |
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68 | #define alloc_workspaces() (0) |
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69 | #define free_workspaces() do { } while(0) |
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70 | #endif /* __KERNEL__ */ |
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71 | |
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72 | static int jffs2_zlib_compress(unsigned char *data_in, |
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73 | unsigned char *cpage_out, |
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74 | uint32_t *sourcelen, uint32_t *dstlen) |
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75 | { |
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76 | int ret; |
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77 | |
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78 | if (*dstlen <= STREAM_END_SPACE) |
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79 | return -1; |
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80 | |
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81 | mutex_lock(&deflate_mutex); |
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82 | |
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83 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { |
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84 | pr_warn("deflateInit failed\n"); |
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85 | mutex_unlock(&deflate_mutex); |
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86 | return -1; |
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87 | } |
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88 | |
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89 | def_strm.next_in = data_in; |
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90 | def_strm.total_in = 0; |
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91 | |
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92 | def_strm.next_out = cpage_out; |
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93 | def_strm.total_out = 0; |
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94 | |
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95 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { |
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96 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); |
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97 | def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); |
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98 | jffs2_dbg(1, "calling deflate with avail_in %d, avail_out %d\n", |
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99 | def_strm.avail_in, def_strm.avail_out); |
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100 | ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); |
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101 | jffs2_dbg(1, "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", |
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102 | def_strm.avail_in, def_strm.avail_out, |
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103 | def_strm.total_in, def_strm.total_out); |
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104 | if (ret != Z_OK) { |
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105 | jffs2_dbg(1, "deflate in loop returned %d\n", ret); |
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106 | zlib_deflateEnd(&def_strm); |
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107 | mutex_unlock(&deflate_mutex); |
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108 | return -1; |
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109 | } |
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110 | } |
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111 | def_strm.avail_out += STREAM_END_SPACE; |
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112 | def_strm.avail_in = 0; |
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113 | ret = zlib_deflate(&def_strm, Z_FINISH); |
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114 | zlib_deflateEnd(&def_strm); |
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115 | |
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116 | if (ret != Z_STREAM_END) { |
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117 | jffs2_dbg(1, "final deflate returned %d\n", ret); |
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118 | ret = -1; |
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119 | goto out; |
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120 | } |
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121 | |
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122 | if (def_strm.total_out >= def_strm.total_in) { |
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123 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n", |
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124 | def_strm.total_in, def_strm.total_out); |
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125 | ret = -1; |
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126 | goto out; |
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127 | } |
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128 | |
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129 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n", |
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130 | def_strm.total_in, def_strm.total_out); |
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131 | |
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132 | *dstlen = def_strm.total_out; |
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133 | *sourcelen = def_strm.total_in; |
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134 | ret = 0; |
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135 | out: |
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136 | mutex_unlock(&deflate_mutex); |
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137 | return ret; |
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138 | } |
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139 | |
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140 | static int jffs2_zlib_decompress(unsigned char *data_in, |
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141 | unsigned char *cpage_out, |
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142 | uint32_t srclen, uint32_t destlen) |
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143 | { |
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144 | int ret; |
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145 | int wbits = MAX_WBITS; |
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146 | |
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147 | mutex_lock(&inflate_mutex); |
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148 | |
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149 | inf_strm.next_in = data_in; |
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150 | inf_strm.avail_in = srclen; |
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151 | inf_strm.total_in = 0; |
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152 | |
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153 | inf_strm.next_out = cpage_out; |
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154 | inf_strm.avail_out = destlen; |
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155 | inf_strm.total_out = 0; |
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156 | |
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157 | /* If it's deflate, and it's got no preset dictionary, then |
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158 | we can tell zlib to skip the adler32 check. */ |
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159 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && |
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160 | ((data_in[0] & 0x0f) == Z_DEFLATED) && |
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161 | !(((data_in[0]<<8) + data_in[1]) % 31)) { |
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162 | |
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163 | jffs2_dbg(2, "inflate skipping adler32\n"); |
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164 | wbits = -((data_in[0] >> 4) + 8); |
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165 | inf_strm.next_in += 2; |
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166 | inf_strm.avail_in -= 2; |
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167 | } else { |
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168 | /* Let this remain D1 for now -- it should never happen */ |
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169 | jffs2_dbg(1, "inflate not skipping adler32\n"); |
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170 | } |
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171 | |
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172 | |
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173 | if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { |
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174 | pr_warn("inflateInit failed\n"); |
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175 | mutex_unlock(&inflate_mutex); |
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176 | return 1; |
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177 | } |
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178 | |
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179 | while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) |
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180 | ; |
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181 | if (ret != Z_STREAM_END) { |
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182 | pr_notice("inflate returned %d\n", ret); |
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183 | } |
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184 | zlib_inflateEnd(&inf_strm); |
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185 | mutex_unlock(&inflate_mutex); |
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186 | return 0; |
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187 | } |
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188 | |
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189 | static struct jffs2_compressor jffs2_zlib_comp = { |
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190 | .priority = JFFS2_ZLIB_PRIORITY, |
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191 | .name = "zlib", |
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192 | .compr = JFFS2_COMPR_ZLIB, |
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193 | .compress = &jffs2_zlib_compress, |
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194 | .decompress = &jffs2_zlib_decompress, |
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195 | #ifdef JFFS2_ZLIB_DISABLED |
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196 | .disabled = 1, |
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197 | #else |
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198 | .disabled = 0, |
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199 | #endif |
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200 | }; |
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201 | |
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202 | int __init jffs2_zlib_init(void) |
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203 | { |
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204 | int ret; |
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205 | |
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206 | ret = alloc_workspaces(); |
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207 | if (ret) |
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208 | return ret; |
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209 | |
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210 | ret = jffs2_register_compressor(&jffs2_zlib_comp); |
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211 | if (ret) |
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212 | free_workspaces(); |
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213 | |
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214 | return ret; |
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215 | } |
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216 | |
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217 | void jffs2_zlib_exit(void) |
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218 | { |
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219 | jffs2_unregister_compressor(&jffs2_zlib_comp); |
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220 | free_workspaces(); |
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221 | } |
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