1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * Created by Arjan van de Ven <arjanv@redhat.com> 6 * 7 * Copyright (C) 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 * $Id: compr.c,v 1.46 2005/11/07 11:14:38 gleixner Exp $ 13 * 14 */ 15 16 #include "compr.h" 17 18 static DEFINE_SPINLOCK(jffs2_compressor_list_lock); 19 20 /* Available compressors are on this list */ 21 static LIST_HEAD(jffs2_compressor_list); 22 23 /* Actual compression mode */ 24 static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; 25 26 /* Statistics for blocks stored without compression */ 27 static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0; 28 29 /* jffs2_compress: 30 * @data: Pointer to uncompressed data 31 * @cdata: Pointer to returned pointer to buffer for compressed data 32 * @datalen: On entry, holds the amount of data available for compression. 33 * On exit, expected to hold the amount of data actually compressed. 34 * @cdatalen: On entry, holds the amount of space available for compressed 35 * data. On exit, expected to hold the actual size of the compressed 36 * data. 37 * 38 * Returns: Lower byte to be stored with data indicating compression type used. 39 * Zero is used to show that the data could not be compressed - the 40 * compressed version was actually larger than the original. 41 * Upper byte will be used later. (soon) 42 * 43 * If the cdata buffer isn't large enough to hold all the uncompressed data, 44 * jffs2_compress should compress as much as will fit, and should set 45 * *datalen accordingly to show the amount of data which were compressed. 46 */ 47 uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 48 unsigned char *data_in, unsigned char **cpage_out, 49 uint32_t *datalen, uint32_t *cdatalen) 50 { 51 int ret = JFFS2_COMPR_NONE; 52 int compr_ret; 53 struct jffs2_compressor *this, *best=NULL; 54 unsigned char *output_buf = NULL, *tmp_buf; 55 uint32_t orig_slen, orig_dlen; 56 uint32_t best_slen=0, best_dlen=0; 57 58 switch (jffs2_compression_mode) { 59 case JFFS2_COMPR_MODE_NONE: 60 break; 61 case JFFS2_COMPR_MODE_PRIORITY: 62 output_buf = kmalloc(*cdatalen,GFP_KERNEL); 63 if (!output_buf) { 64 printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n"); 65 goto out; 66 } 67 orig_slen = *datalen; 68 orig_dlen = *cdatalen; 69 spin_lock(&jffs2_compressor_list_lock); 70 list_for_each_entry(this, &jffs2_compressor_list, list) { 71 /* Skip decompress-only backwards-compatibility and disabled modules */ 72 if ((!this->compress)||(this->disabled)) 73 continue; 74 75 this->usecount++; 76 spin_unlock(&jffs2_compressor_list_lock); 77 *datalen = orig_slen; 78 *cdatalen = orig_dlen; 79 compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL); 80 spin_lock(&jffs2_compressor_list_lock); 81 this->usecount--; 82 if (!compr_ret) { 83 ret = this->compr; 84 this->stat_compr_blocks++; 85 this->stat_compr_orig_size += *datalen; 86 this->stat_compr_new_size += *cdatalen; 87 break; 88 } 89 } 90 spin_unlock(&jffs2_compressor_list_lock); 91 if (ret == JFFS2_COMPR_NONE) kfree(output_buf); 92 break; 93 case JFFS2_COMPR_MODE_SIZE: 94 orig_slen = *datalen; 95 orig_dlen = *cdatalen; 96 spin_lock(&jffs2_compressor_list_lock); 97 list_for_each_entry(this, &jffs2_compressor_list, list) { 98 /* Skip decompress-only backwards-compatibility and disabled modules */ 99 if ((!this->compress)||(this->disabled)) 100 continue; 101 /* Allocating memory for output buffer if necessary */ 102 if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) { 103 spin_unlock(&jffs2_compressor_list_lock); 104 kfree(this->compr_buf); 105 spin_lock(&jffs2_compressor_list_lock); 106 this->compr_buf_size=0; 107 this->compr_buf=NULL; 108 } 109 if (!this->compr_buf) { 110 spin_unlock(&jffs2_compressor_list_lock); 111 tmp_buf = kmalloc(orig_dlen,GFP_KERNEL); 112 spin_lock(&jffs2_compressor_list_lock); 113 if (!tmp_buf) { 114 printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen); 115 continue; 116 } 117 else { 118 this->compr_buf = tmp_buf; 119 this->compr_buf_size = orig_dlen; 120 } 121 } 122 this->usecount++; 123 spin_unlock(&jffs2_compressor_list_lock); 124 *datalen = orig_slen; 125 *cdatalen = orig_dlen; 126 compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL); 127 spin_lock(&jffs2_compressor_list_lock); 128 this->usecount--; 129 if (!compr_ret) { 130 if ((!best_dlen)||(best_dlen>*cdatalen)) { 131 best_dlen = *cdatalen; 132 best_slen = *datalen; 133 best = this; 134 } 135 } 136 } 137 if (best_dlen) { 138 *cdatalen = best_dlen; 139 *datalen = best_slen; 140 output_buf = best->compr_buf; 141 best->compr_buf = NULL; 142 best->compr_buf_size = 0; 143 best->stat_compr_blocks++; 144 best->stat_compr_orig_size += best_slen; 145 best->stat_compr_new_size += best_dlen; 146 ret = best->compr; 147 } 148 spin_unlock(&jffs2_compressor_list_lock); 149 break; 150 default: 151 printk(KERN_ERR "JFFS2: unknow compression mode.\n"); 152 } 153 out: 154 if (ret == JFFS2_COMPR_NONE) { 155 *cpage_out = data_in; 156 *datalen = *cdatalen; 157 none_stat_compr_blocks++; 158 none_stat_compr_size += *datalen; 159 } 160 else { 161 *cpage_out = output_buf; 162 } 163 return ret; 164 } 165 166 int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 167 uint16_t comprtype, unsigned char *cdata_in, 168 unsigned char *data_out, uint32_t cdatalen, uint32_t datalen) 169 { 170 struct jffs2_compressor *this; 171 int ret; 172 173 /* Older code had a bug where it would write non-zero 'usercompr' 174 fields. Deal with it. */ 175 if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB) 176 comprtype &= 0xff; 177 178 switch (comprtype & 0xff) { 179 case JFFS2_COMPR_NONE: 180 /* This should be special-cased elsewhere, but we might as well deal with it */ 181 memcpy(data_out, cdata_in, datalen); 182 none_stat_decompr_blocks++; 183 break; 184 case JFFS2_COMPR_ZERO: 185 memset(data_out, 0, datalen); 186 break; 187 default: 188 spin_lock(&jffs2_compressor_list_lock); 189 list_for_each_entry(this, &jffs2_compressor_list, list) { 190 if (comprtype == this->compr) { 191 this->usecount++; 192 spin_unlock(&jffs2_compressor_list_lock); 193 ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL); 194 spin_lock(&jffs2_compressor_list_lock); 195 if (ret) { 196 printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret); 197 } 198 else { 199 this->stat_decompr_blocks++; 200 } 201 this->usecount--; 202 spin_unlock(&jffs2_compressor_list_lock); 203 return ret; 204 } 205 } 206 printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype); 207 spin_unlock(&jffs2_compressor_list_lock); 208 return -EIO; 209 } 210 return 0; 211 } 212 213 int jffs2_register_compressor(struct jffs2_compressor *comp) 214 { 215 struct jffs2_compressor *this; 216 217 if (!comp->name) { 218 printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n"); 219 return -1; 220 } 221 comp->compr_buf_size=0; 222 comp->compr_buf=NULL; 223 comp->usecount=0; 224 comp->stat_compr_orig_size=0; 225 comp->stat_compr_new_size=0; 226 comp->stat_compr_blocks=0; 227 comp->stat_decompr_blocks=0; 228 D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name)); 229 230 spin_lock(&jffs2_compressor_list_lock); 231 232 list_for_each_entry(this, &jffs2_compressor_list, list) { 233 if (this->priority < comp->priority) { 234 list_add(&comp->list, this->list.prev); 235 goto out; 236 } 237 } 238 list_add_tail(&comp->list, &jffs2_compressor_list); 239 out: 240 D2(list_for_each_entry(this, &jffs2_compressor_list, list) { 241 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); 242 }) 243 244 spin_unlock(&jffs2_compressor_list_lock); 245 246 return 0; 247 } 248 249 int jffs2_unregister_compressor(struct jffs2_compressor *comp) 250 { 251 D2(struct jffs2_compressor *this;) 252 253 D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name)); 254 255 spin_lock(&jffs2_compressor_list_lock); 256 257 if (comp->usecount) { 258 spin_unlock(&jffs2_compressor_list_lock); 259 printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n"); 260 return -1; 261 } 262 list_del(&comp->list); 263 264 D2(list_for_each_entry(this, &jffs2_compressor_list, list) { 265 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); 266 }) 267 spin_unlock(&jffs2_compressor_list_lock); 268 return 0; 269 } 270 271 #ifdef CONFIG_JFFS2_PROC 272 273 #define JFFS2_STAT_BUF_SIZE 16000 274 275 char *jffs2_list_compressors(void) 276 { 277 struct jffs2_compressor *this; 278 char *buf, *act_buf; 279 280 act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); 281 list_for_each_entry(this, &jffs2_compressor_list, list) { 282 act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority); 283 if ((this->disabled)||(!this->compress)) 284 act_buf += sprintf(act_buf,"disabled"); 285 else 286 act_buf += sprintf(act_buf,"enabled"); 287 act_buf += sprintf(act_buf,"\n"); 288 } 289 return buf; 290 } 291 292 char *jffs2_stats(void) 293 { 294 struct jffs2_compressor *this; 295 char *buf, *act_buf; 296 297 act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); 298 299 act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n"); 300 act_buf += sprintf(act_buf,"%10s ","none"); 301 act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks, 302 none_stat_compr_size, none_stat_decompr_blocks); 303 spin_lock(&jffs2_compressor_list_lock); 304 list_for_each_entry(this, &jffs2_compressor_list, list) { 305 act_buf += sprintf(act_buf,"%10s ",this->name); 306 if ((this->disabled)||(!this->compress)) 307 act_buf += sprintf(act_buf,"- "); 308 else 309 act_buf += sprintf(act_buf,"+ "); 310 act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks, 311 this->stat_compr_new_size, this->stat_compr_orig_size, 312 this->stat_decompr_blocks); 313 act_buf += sprintf(act_buf,"\n"); 314 } 315 spin_unlock(&jffs2_compressor_list_lock); 316 317 return buf; 318 } 319 320 char *jffs2_get_compression_mode_name(void) 321 { 322 switch (jffs2_compression_mode) { 323 case JFFS2_COMPR_MODE_NONE: 324 return "none"; 325 case JFFS2_COMPR_MODE_PRIORITY: 326 return "priority"; 327 case JFFS2_COMPR_MODE_SIZE: 328 return "size"; 329 } 330 return "unkown"; 331 } 332 333 int jffs2_set_compression_mode_name(const char *name) 334 { 335 if (!strcmp("none",name)) { 336 jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; 337 return 0; 338 } 339 if (!strcmp("priority",name)) { 340 jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; 341 return 0; 342 } 343 if (!strcmp("size",name)) { 344 jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; 345 return 0; 346 } 347 return 1; 348 } 349 350 static int jffs2_compressor_Xable(const char *name, int disabled) 351 { 352 struct jffs2_compressor *this; 353 spin_lock(&jffs2_compressor_list_lock); 354 list_for_each_entry(this, &jffs2_compressor_list, list) { 355 if (!strcmp(this->name, name)) { 356 this->disabled = disabled; 357 spin_unlock(&jffs2_compressor_list_lock); 358 return 0; 359 } 360 } 361 spin_unlock(&jffs2_compressor_list_lock); 362 printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); 363 return 1; 364 } 365 366 int jffs2_enable_compressor_name(const char *name) 367 { 368 return jffs2_compressor_Xable(name, 0); 369 } 370 371 int jffs2_disable_compressor_name(const char *name) 372 { 373 return jffs2_compressor_Xable(name, 1); 374 } 375 376 int jffs2_set_compressor_priority(const char *name, int priority) 377 { 378 struct jffs2_compressor *this,*comp; 379 spin_lock(&jffs2_compressor_list_lock); 380 list_for_each_entry(this, &jffs2_compressor_list, list) { 381 if (!strcmp(this->name, name)) { 382 this->priority = priority; 383 comp = this; 384 goto reinsert; 385 } 386 } 387 spin_unlock(&jffs2_compressor_list_lock); 388 printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); 389 return 1; 390 reinsert: 391 /* list is sorted in the order of priority, so if 392 we change it we have to reinsert it into the 393 good place */ 394 list_del(&comp->list); 395 list_for_each_entry(this, &jffs2_compressor_list, list) { 396 if (this->priority < comp->priority) { 397 list_add(&comp->list, this->list.prev); 398 spin_unlock(&jffs2_compressor_list_lock); 399 return 0; 400 } 401 } 402 list_add_tail(&comp->list, &jffs2_compressor_list); 403 spin_unlock(&jffs2_compressor_list_lock); 404 return 0; 405 } 406 407 #endif 408 409 void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) 410 { 411 if (orig != comprbuf) 412 kfree(comprbuf); 413 } 414 415 int __init jffs2_compressors_init(void) 416 { 417 /* Registering compressors */ 418 #ifdef CONFIG_JFFS2_ZLIB 419 jffs2_zlib_init(); 420 #endif 421 #ifdef CONFIG_JFFS2_RTIME 422 jffs2_rtime_init(); 423 #endif 424 #ifdef CONFIG_JFFS2_RUBIN 425 jffs2_rubinmips_init(); 426 jffs2_dynrubin_init(); 427 #endif 428 /* Setting default compression mode */ 429 #ifdef CONFIG_JFFS2_CMODE_NONE 430 jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; 431 D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");) 432 #else 433 #ifdef CONFIG_JFFS2_CMODE_SIZE 434 jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; 435 D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");) 436 #else 437 D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");) 438 #endif 439 #endif 440 return 0; 441 } 442 443 int jffs2_compressors_exit(void) 444 { 445 /* Unregistering compressors */ 446 #ifdef CONFIG_JFFS2_RUBIN 447 jffs2_dynrubin_exit(); 448 jffs2_rubinmips_exit(); 449 #endif 450 #ifdef CONFIG_JFFS2_RTIME 451 jffs2_rtime_exit(); 452 #endif 453 #ifdef CONFIG_JFFS2_ZLIB 454 jffs2_zlib_exit(); 455 #endif 456 return 0; 457 } 458