1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 Red Hat, Inc. 5 * Created by Arjan van de Ven <arjanv@redhat.com> 6 * 7 * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>, 8 * University of Szeged, Hungary 9 * 10 * For licensing information, see the file 'LICENCE' in this directory. 11 * 12 */ 13 14 #include "compr.h" 15 16 static DEFINE_SPINLOCK(jffs2_compressor_list_lock); 17 18 /* Available compressors are on this list */ 19 static LIST_HEAD(jffs2_compressor_list); 20 21 /* Actual compression mode */ 22 static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; 23 24 /* Statistics for blocks stored without compression */ 25 static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0; 26 27 /* jffs2_compress: 28 * @data: Pointer to uncompressed data 29 * @cdata: Pointer to returned pointer to buffer for compressed data 30 * @datalen: On entry, holds the amount of data available for compression. 31 * On exit, expected to hold the amount of data actually compressed. 32 * @cdatalen: On entry, holds the amount of space available for compressed 33 * data. On exit, expected to hold the actual size of the compressed 34 * data. 35 * 36 * Returns: Lower byte to be stored with data indicating compression type used. 37 * Zero is used to show that the data could not be compressed - the 38 * compressed version was actually larger than the original. 39 * Upper byte will be used later. (soon) 40 * 41 * If the cdata buffer isn't large enough to hold all the uncompressed data, 42 * jffs2_compress should compress as much as will fit, and should set 43 * *datalen accordingly to show the amount of data which were compressed. 44 */ 45 uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 46 unsigned char *data_in, unsigned char **cpage_out, 47 uint32_t *datalen, uint32_t *cdatalen) 48 { 49 int ret = JFFS2_COMPR_NONE; 50 int compr_ret; 51 struct jffs2_compressor *this, *best=NULL; 52 unsigned char *output_buf = NULL, *tmp_buf; 53 uint32_t orig_slen, orig_dlen; 54 uint32_t best_slen=0, best_dlen=0; 55 56 switch (jffs2_compression_mode) { 57 case JFFS2_COMPR_MODE_NONE: 58 break; 59 case JFFS2_COMPR_MODE_PRIORITY: 60 output_buf = kmalloc(*cdatalen,GFP_KERNEL); 61 if (!output_buf) { 62 printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n"); 63 goto out; 64 } 65 orig_slen = *datalen; 66 orig_dlen = *cdatalen; 67 spin_lock(&jffs2_compressor_list_lock); 68 list_for_each_entry(this, &jffs2_compressor_list, list) { 69 /* Skip decompress-only backwards-compatibility and disabled modules */ 70 if ((!this->compress)||(this->disabled)) 71 continue; 72 73 this->usecount++; 74 spin_unlock(&jffs2_compressor_list_lock); 75 *datalen = orig_slen; 76 *cdatalen = orig_dlen; 77 compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL); 78 spin_lock(&jffs2_compressor_list_lock); 79 this->usecount--; 80 if (!compr_ret) { 81 ret = this->compr; 82 this->stat_compr_blocks++; 83 this->stat_compr_orig_size += *datalen; 84 this->stat_compr_new_size += *cdatalen; 85 break; 86 } 87 } 88 spin_unlock(&jffs2_compressor_list_lock); 89 if (ret == JFFS2_COMPR_NONE) 90 kfree(output_buf); 91 break; 92 case JFFS2_COMPR_MODE_SIZE: 93 orig_slen = *datalen; 94 orig_dlen = *cdatalen; 95 spin_lock(&jffs2_compressor_list_lock); 96 list_for_each_entry(this, &jffs2_compressor_list, list) { 97 /* Skip decompress-only backwards-compatibility and disabled modules */ 98 if ((!this->compress)||(this->disabled)) 99 continue; 100 /* Allocating memory for output buffer if necessary */ 101 if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) { 102 spin_unlock(&jffs2_compressor_list_lock); 103 kfree(this->compr_buf); 104 spin_lock(&jffs2_compressor_list_lock); 105 this->compr_buf_size=0; 106 this->compr_buf=NULL; 107 } 108 if (!this->compr_buf) { 109 spin_unlock(&jffs2_compressor_list_lock); 110 tmp_buf = kmalloc(orig_dlen,GFP_KERNEL); 111 spin_lock(&jffs2_compressor_list_lock); 112 if (!tmp_buf) { 113 printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen); 114 continue; 115 } 116 else { 117 this->compr_buf = tmp_buf; 118 this->compr_buf_size = orig_dlen; 119 } 120 } 121 this->usecount++; 122 spin_unlock(&jffs2_compressor_list_lock); 123 *datalen = orig_slen; 124 *cdatalen = orig_dlen; 125 compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL); 126 spin_lock(&jffs2_compressor_list_lock); 127 this->usecount--; 128 if (!compr_ret) { 129 if ((!best_dlen)||(best_dlen>*cdatalen)) { 130 best_dlen = *cdatalen; 131 best_slen = *datalen; 132 best = this; 133 } 134 } 135 } 136 if (best_dlen) { 137 *cdatalen = best_dlen; 138 *datalen = best_slen; 139 output_buf = best->compr_buf; 140 best->compr_buf = NULL; 141 best->compr_buf_size = 0; 142 best->stat_compr_blocks++; 143 best->stat_compr_orig_size += best_slen; 144 best->stat_compr_new_size += best_dlen; 145 ret = best->compr; 146 } 147 spin_unlock(&jffs2_compressor_list_lock); 148 break; 149 default: 150 printk(KERN_ERR "JFFS2: unknow compression mode.\n"); 151 } 152 out: 153 if (ret == JFFS2_COMPR_NONE) { 154 *cpage_out = data_in; 155 *datalen = *cdatalen; 156 none_stat_compr_blocks++; 157 none_stat_compr_size += *datalen; 158 } 159 else { 160 *cpage_out = output_buf; 161 } 162 return ret; 163 } 164 165 int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 166 uint16_t comprtype, unsigned char *cdata_in, 167 unsigned char *data_out, uint32_t cdatalen, uint32_t datalen) 168 { 169 struct jffs2_compressor *this; 170 int ret; 171 172 /* Older code had a bug where it would write non-zero 'usercompr' 173 fields. Deal with it. */ 174 if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB) 175 comprtype &= 0xff; 176 177 switch (comprtype & 0xff) { 178 case JFFS2_COMPR_NONE: 179 /* This should be special-cased elsewhere, but we might as well deal with it */ 180 memcpy(data_out, cdata_in, datalen); 181 none_stat_decompr_blocks++; 182 break; 183 case JFFS2_COMPR_ZERO: 184 memset(data_out, 0, datalen); 185 break; 186 default: 187 spin_lock(&jffs2_compressor_list_lock); 188 list_for_each_entry(this, &jffs2_compressor_list, list) { 189 if (comprtype == this->compr) { 190 this->usecount++; 191 spin_unlock(&jffs2_compressor_list_lock); 192 ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL); 193 spin_lock(&jffs2_compressor_list_lock); 194 if (ret) { 195 printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret); 196 } 197 else { 198 this->stat_decompr_blocks++; 199 } 200 this->usecount--; 201 spin_unlock(&jffs2_compressor_list_lock); 202 return ret; 203 } 204 } 205 printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype); 206 spin_unlock(&jffs2_compressor_list_lock); 207 return -EIO; 208 } 209 return 0; 210 } 211 212 int jffs2_register_compressor(struct jffs2_compressor *comp) 213 { 214 struct jffs2_compressor *this; 215 216 if (!comp->name) { 217 printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n"); 218 return -1; 219 } 220 comp->compr_buf_size=0; 221 comp->compr_buf=NULL; 222 comp->usecount=0; 223 comp->stat_compr_orig_size=0; 224 comp->stat_compr_new_size=0; 225 comp->stat_compr_blocks=0; 226 comp->stat_decompr_blocks=0; 227 D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name)); 228 229 spin_lock(&jffs2_compressor_list_lock); 230 231 list_for_each_entry(this, &jffs2_compressor_list, list) { 232 if (this->priority < comp->priority) { 233 list_add(&comp->list, this->list.prev); 234 goto out; 235 } 236 } 237 list_add_tail(&comp->list, &jffs2_compressor_list); 238 out: 239 D2(list_for_each_entry(this, &jffs2_compressor_list, list) { 240 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); 241 }) 242 243 spin_unlock(&jffs2_compressor_list_lock); 244 245 return 0; 246 } 247 248 int jffs2_unregister_compressor(struct jffs2_compressor *comp) 249 { 250 D2(struct jffs2_compressor *this;) 251 252 D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name)); 253 254 spin_lock(&jffs2_compressor_list_lock); 255 256 if (comp->usecount) { 257 spin_unlock(&jffs2_compressor_list_lock); 258 printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n"); 259 return -1; 260 } 261 list_del(&comp->list); 262 263 D2(list_for_each_entry(this, &jffs2_compressor_list, list) { 264 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); 265 }) 266 spin_unlock(&jffs2_compressor_list_lock); 267 return 0; 268 } 269 270 void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) 271 { 272 if (orig != comprbuf) 273 kfree(comprbuf); 274 } 275 276 int __init jffs2_compressors_init(void) 277 { 278 /* Registering compressors */ 279 #ifdef CONFIG_JFFS2_ZLIB 280 jffs2_zlib_init(); 281 #endif 282 #ifdef CONFIG_JFFS2_RTIME 283 jffs2_rtime_init(); 284 #endif 285 #ifdef CONFIG_JFFS2_RUBIN 286 jffs2_rubinmips_init(); 287 jffs2_dynrubin_init(); 288 #endif 289 /* Setting default compression mode */ 290 #ifdef CONFIG_JFFS2_CMODE_NONE 291 jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; 292 D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");) 293 #else 294 #ifdef CONFIG_JFFS2_CMODE_SIZE 295 jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; 296 D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");) 297 #else 298 D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");) 299 #endif 300 #endif 301 return 0; 302 } 303 304 int jffs2_compressors_exit(void) 305 { 306 /* Unregistering compressors */ 307 #ifdef CONFIG_JFFS2_RUBIN 308 jffs2_dynrubin_exit(); 309 jffs2_rubinmips_exit(); 310 #endif 311 #ifdef CONFIG_JFFS2_RTIME 312 jffs2_rtime_exit(); 313 #endif 314 #ifdef CONFIG_JFFS2_ZLIB 315 jffs2_zlib_exit(); 316 #endif 317 return 0; 318 } 319