fs/jffs2/compr.c

   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 1.41 2004/06/24 09:51:38 havasi Exp $
  13  *
  14  */
  15
  16 #include "compr.h"
  17
  18 static spinlock_t jffs2_compressor_list_lock = SPIN_LOCK_UNLOCKED;
  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 void jffs2_set_compression_mode(int mode)
  27 {
  28         jffs2_compression_mode = mode;
  29 }
  30
  31 int jffs2_get_compression_mode(void)
  32 {
  33         return jffs2_compression_mode;
  34 }
  35
  36 /* Statistics for blocks stored without compression */
  37 static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
  38
  39 /* jffs2_compress:
  40  * @data: Pointer to uncompressed data
  41  * @cdata: Pointer to returned pointer to buffer for compressed data
  42  * @datalen: On entry, holds the amount of data available for compression.
  43  *      On exit, expected to hold the amount of data actually compressed.
  44  * @cdatalen: On entry, holds the amount of space available for compressed
  45  *      data. On exit, expected to hold the actual size of the compressed
  46  *      data.
  47  *
  48  * Returns: Lower byte to be stored with data indicating compression type used.
  49  * Zero is used to show that the data could not be compressed - the
  50  * compressed version was actually larger than the original.
  51  * Upper byte will be used later. (soon)
  52  *
  53  * If the cdata buffer isn't large enough to hold all the uncompressed data,
  54  * jffs2_compress should compress as much as will fit, and should set
  55  * *datalen accordingly to show the amount of data which were compressed.
  56  */
  57 uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
  58                              unsigned char *data_in, unsigned char **cpage_out,
  59                              uint32_t *datalen, uint32_t *cdatalen)
  60 {
  61         int ret = JFFS2_COMPR_NONE;
  62         int compr_ret;
  63         struct jffs2_compressor *this, *best=NULL;
  64         unsigned char *output_buf = NULL, *tmp_buf;
  65         uint32_t orig_slen, orig_dlen;
  66         uint32_t best_slen=0, best_dlen=0;
  67
  68         switch (jffs2_compression_mode) {
  69         case JFFS2_COMPR_MODE_NONE:
  70                 break;
  71         case JFFS2_COMPR_MODE_PRIORITY:
  72                 output_buf = kmalloc(*cdatalen,GFP_KERNEL);
  73                 if (!output_buf) {
  74                         printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
  75                         goto out;
  76                 }
  77                 orig_slen = *datalen;
  78                 orig_dlen = *cdatalen;
  79                 spin_lock(&jffs2_compressor_list_lock);
  80                 list_for_each_entry(this, &jffs2_compressor_list, list) {
  81                         /* Skip decompress-only backwards-compatibility and disabled modules */
  82                         if ((!this->compress)||(this->disabled))
  83                                 continue;
  84
  85                         this->usecount++;
  86                         spin_unlock(&jffs2_compressor_list_lock);
  87                         *datalen  = orig_slen;
  88                         *cdatalen = orig_dlen;
  89                         compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL);
  90                         spin_lock(&jffs2_compressor_list_lock);
  91                         this->usecount--;
  92                         if (!compr_ret) {
  93                                 ret = this->compr;
  94                                 this->stat_compr_blocks++;
  95                                 this->stat_compr_orig_size += *datalen;
  96                                 this->stat_compr_new_size  += *cdatalen;
  97                                 break;
  98                         }
  99                 }
 100                 spin_unlock(&jffs2_compressor_list_lock);
 101                 if (ret == JFFS2_COMPR_NONE) kfree(output_buf);
 102                 break;
 103         case JFFS2_COMPR_MODE_SIZE:
 104                 orig_slen = *datalen;
 105                 orig_dlen = *cdatalen;
 106                 spin_lock(&jffs2_compressor_list_lock);
 107                 list_for_each_entry(this, &jffs2_compressor_list, list) {
 108                         /* Skip decompress-only backwards-compatibility and disabled modules */
 109                         if ((!this->compress)||(this->disabled))
 110                                 continue;
 111                         /* Allocating memory for output buffer if necessary */
 112                         if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) {
 113                                 spin_unlock(&jffs2_compressor_list_lock);
 114                                 kfree(this->compr_buf);
 115                                 spin_lock(&jffs2_compressor_list_lock);
 116                                 this->compr_buf_size=0;
 117                                 this->compr_buf=NULL;
 118                         }
 119                         if (!this->compr_buf) {
 120                                 spin_unlock(&jffs2_compressor_list_lock);
 121                                 tmp_buf = kmalloc(orig_dlen,GFP_KERNEL);
 122                                 spin_lock(&jffs2_compressor_list_lock);
 123                                 if (!tmp_buf) {
 124                                         printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen);
 125                                         continue;
 126                                 }
 127                                 else {
 128                                         this->compr_buf = tmp_buf;
 129                                         this->compr_buf_size = orig_dlen;
 130                                 }
 131                         }
 132                         this->usecount++;
 133                         spin_unlock(&jffs2_compressor_list_lock);
 134                         *datalen  = orig_slen;
 135                         *cdatalen = orig_dlen;
 136                         compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL);
 137                         spin_lock(&jffs2_compressor_list_lock);
 138                         this->usecount--;
 139                         if (!compr_ret) {
 140                                 if ((!best_dlen)||(best_dlen>*cdatalen)) {
 141                                         best_dlen = *cdatalen;
 142                                         best_slen = *datalen;
 143                                         best = this;
 144                                 }
 145                         }
 146                 }
 147                 if (best_dlen) {
 148                         *cdatalen = best_dlen;
 149                         *datalen  = best_slen;
 150                         output_buf = best->compr_buf;
 151                         best->compr_buf = NULL;
 152                         best->compr_buf_size = 0;
 153                         best->stat_compr_blocks++;
 154                         best->stat_compr_orig_size += best_slen;
 155                         best->stat_compr_new_size  += best_dlen;
 156                         ret = best->compr;
 157                 }
 158                 spin_unlock(&jffs2_compressor_list_lock);
 159                 break;
 160         default:
 161                 printk(KERN_ERR "JFFS2: unknow compression mode.\n");
 162         }
 163  out:
 164         if (ret == JFFS2_COMPR_NONE) {
 165                 *cpage_out = data_in;
 166                 *datalen = *cdatalen;
 167                 none_stat_compr_blocks++;
 168                 none_stat_compr_size += *datalen;
 169         }
 170         else {
 171                 *cpage_out = output_buf;
 172         }
 173         return ret;
 174 }
 175
 176 int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 177                      uint16_t comprtype, unsigned char *cdata_in,
 178                      unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
 179 {
 180         struct jffs2_compressor *this;
 181         int ret;
 182
 183         switch (comprtype & 0xff) {
 184         case JFFS2_COMPR_NONE:
 185                 /* This should be special-cased elsewhere, but we might as well deal with it */
 186                 memcpy(data_out, cdata_in, datalen);
 187                 none_stat_decompr_blocks++;
 188                 break;
 189         case JFFS2_COMPR_ZERO:
 190                 memset(data_out, 0, datalen);
 191                 break;
 192         default:
 193                 spin_lock(&jffs2_compressor_list_lock);
 194                 list_for_each_entry(this, &jffs2_compressor_list, list) {
 195                         if (comprtype == this->compr) {
 196                                 this->usecount++;
 197                                 spin_unlock(&jffs2_compressor_list_lock);
 198                                 ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL);
 199                                 spin_lock(&jffs2_compressor_list_lock);
 200                                 if (ret) {
 201                                         printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
 202                                 }
 203                                 else {
 204                                         this->stat_decompr_blocks++;
 205                                 }
 206                                 this->usecount--;
 207                                 spin_unlock(&jffs2_compressor_list_lock);
 208                                 return ret;
 209                         }
 210                 }
 211                 printk(KERN_WARNING "JFFS2 compression type 0x%02x not avaiable.\n", comprtype);
 212                 spin_unlock(&jffs2_compressor_list_lock);
 213                 return -EIO;
 214         }
 215         return 0;
 216 }
 217
 218 int jffs2_register_compressor(struct jffs2_compressor *comp)
 219 {
 220         struct jffs2_compressor *this;
 221
 222         if (!comp->name) {
 223                 printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n");
 224                 return -1;
 225         }
 226         comp->compr_buf_size=0;
 227         comp->compr_buf=NULL;
 228         comp->usecount=0;
 229         comp->stat_compr_orig_size=0;
 230         comp->stat_compr_new_size=0;
 231         comp->stat_compr_blocks=0;
 232         comp->stat_decompr_blocks=0;
 233         D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));
 234
 235         spin_lock(&jffs2_compressor_list_lock);
 236
 237         list_for_each_entry(this, &jffs2_compressor_list, list) {
 238                 if (this->priority < comp->priority) {
 239                         list_add(&comp->list, this->list.prev);
 240                         goto out;
 241                 }
 242         }
 243         list_add_tail(&comp->list, &jffs2_compressor_list);
 244 out:
 245         D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
 246                 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
 247         })
 248
 249         spin_unlock(&jffs2_compressor_list_lock);
 250
 251         return 0;
 252 }
 253
 254 int jffs2_unregister_compressor(struct jffs2_compressor *comp)
 255 {
 256         D2(struct jffs2_compressor *this;)
 257
 258         D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));
 259
 260         spin_lock(&jffs2_compressor_list_lock);
 261
 262         if (comp->usecount) {
 263                 spin_unlock(&jffs2_compressor_list_lock);
 264                 printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
 265                 return -1;
 266         }
 267         list_del(&comp->list);
 268
 269         D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
 270                 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
 271         })
 272         spin_unlock(&jffs2_compressor_list_lock);
 273         return 0;
 274 }
 275
 276 #ifdef CONFIG_JFFS2_PROC
 277
 278 #define JFFS2_STAT_BUF_SIZE 16000
 279
 280 char *jffs2_list_compressors(void)
 281 {
 282         struct jffs2_compressor *this;
 283         char *buf, *act_buf;
 284
 285         act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
 286         list_for_each_entry(this, &jffs2_compressor_list, list) {
 287                 act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority);
 288                 if ((this->disabled)||(!this->compress))
 289                         act_buf += sprintf(act_buf,"disabled");
 290                 else
 291                         act_buf += sprintf(act_buf,"enabled");
 292                 act_buf += sprintf(act_buf,"\n");
 293         }
 294         return buf;
 295 }
 296
 297 char *jffs2_stats(void)
 298 {
 299         struct jffs2_compressor *this;
 300         char *buf, *act_buf;
 301
 302         act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
 303
 304         act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n");
 305         act_buf += sprintf(act_buf,"%10s   ","none");
 306         act_buf += sprintf(act_buf,"compr: %d blocks (%d)  decompr: %d blocks\n", none_stat_compr_blocks,
 307                            none_stat_compr_size, none_stat_decompr_blocks);
 308         spin_lock(&jffs2_compressor_list_lock);
 309         list_for_each_entry(this, &jffs2_compressor_list, list) {
 310                 act_buf += sprintf(act_buf,"%10s ",this->name);
 311                 if ((this->disabled)||(!this->compress))
 312                         act_buf += sprintf(act_buf,"- ");
 313                 else
 314                         act_buf += sprintf(act_buf,"+ ");
 315                 act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d)  decompr: %d blocks ", this->stat_compr_blocks,
 316                                    this->stat_compr_new_size, this->stat_compr_orig_size,
 317                                    this->stat_decompr_blocks);
 318                 act_buf += sprintf(act_buf,"\n");
 319         }
 320         spin_unlock(&jffs2_compressor_list_lock);
 321
 322         return buf;
 323 }
 324
 325 char *jffs2_get_compression_mode_name(void)
 326 {
 327         switch (jffs2_compression_mode) {
 328         case JFFS2_COMPR_MODE_NONE:
 329                 return "none";
 330         case JFFS2_COMPR_MODE_PRIORITY:
 331                 return "priority";
 332         case JFFS2_COMPR_MODE_SIZE:
 333                 return "size";
 334         }
 335         return "unkown";
 336 }
 337
 338 int jffs2_set_compression_mode_name(const char *name)
 339 {
 340         if (!strcmp("none",name)) {
 341                 jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
 342                 return 0;
 343         }
 344         if (!strcmp("priority",name)) {
 345                 jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
 346                 return 0;
 347         }
 348         if (!strcmp("size",name)) {
 349                 jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
 350                 return 0;
 351         }
 352         return 1;
 353 }
 354
 355 static int jffs2_compressor_Xable(const char *name, int disabled)
 356 {
 357         struct jffs2_compressor *this;
 358         spin_lock(&jffs2_compressor_list_lock);
 359         list_for_each_entry(this, &jffs2_compressor_list, list) {
 360                 if (!strcmp(this->name, name)) {
 361                         this->disabled = disabled;
 362                         spin_unlock(&jffs2_compressor_list_lock);
 363                         return 0;
 364                 }
 365         }
 366         spin_unlock(&jffs2_compressor_list_lock);
 367         printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
 368         return 1;
 369 }
 370
 371 int jffs2_enable_compressor_name(const char *name)
 372 {
 373         return jffs2_compressor_Xable(name, 0);
 374 }
 375
 376 int jffs2_disable_compressor_name(const char *name)
 377 {
 378         return jffs2_compressor_Xable(name, 1);
 379 }
 380
 381 int jffs2_set_compressor_priority(const char *name, int priority)
 382 {
 383         struct jffs2_compressor *this,*comp;
 384         spin_lock(&jffs2_compressor_list_lock);
 385         list_for_each_entry(this, &jffs2_compressor_list, list) {
 386                 if (!strcmp(this->name, name)) {
 387                         this->priority = priority;
 388                         comp = this;
 389                         goto reinsert;
 390                 }
 391         }
 392         spin_unlock(&jffs2_compressor_list_lock);
 393         printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
 394         return 1;
 395 reinsert:
 396         /* list is sorted in the order of priority, so if
 397            we change it we have to reinsert it into the
 398            good place */
 399         list_del(&comp->list);
 400         list_for_each_entry(this, &jffs2_compressor_list, list) {
 401                 if (this->priority < comp->priority) {
 402                         list_add(&comp->list, this->list.prev);
 403                         spin_unlock(&jffs2_compressor_list_lock);
 404                         return 0;
 405                 }
 406         }
 407         list_add_tail(&comp->list, &jffs2_compressor_list);
 408         spin_unlock(&jffs2_compressor_list_lock);
 409         return 0;
 410 }
 411
 412 #endif
 413
 414 void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
 415 {
 416         if (orig != comprbuf)
 417                 kfree(comprbuf);
 418 }
 419
 420 int jffs2_compressors_init(void)
 421 {
 422 /* Registering compressors */
 423 #ifdef CONFIG_JFFS2_ZLIB
 424         jffs2_zlib_init();
 425 #endif
 426 #ifdef CONFIG_JFFS2_RTIME
 427         jffs2_rtime_init();
 428 #endif
 429 #ifdef CONFIG_JFFS2_RUBIN
 430         jffs2_rubinmips_init();
 431         jffs2_dynrubin_init();
 432 #endif
 433 #ifdef CONFIG_JFFS2_LZARI
 434         jffs2_lzari_init();
 435 #endif
 436 #ifdef CONFIG_JFFS2_LZO
 437         jffs2_lzo_init();
 438 #endif
 439 /* Setting default compression mode */
 440 #ifdef CONFIG_JFFS2_CMODE_NONE
 441         jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
 442         D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
 443 #else
 444 #ifdef CONFIG_JFFS2_CMODE_SIZE
 445         jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
 446         D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
 447 #else
 448         D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
 449 #endif
 450 #endif
 451         return 0;
 452 }
 453
 454 int jffs2_compressors_exit(void)
 455 {
 456 /* Unregistering compressors */
 457 #ifdef CONFIG_JFFS2_LZO
 458         jffs2_lzo_exit();
 459 #endif
 460 #ifdef CONFIG_JFFS2_LZARI
 461         jffs2_lzari_exit();
 462 #endif
 463 #ifdef CONFIG_JFFS2_RUBIN
 464         jffs2_dynrubin_exit();
 465         jffs2_rubinmips_exit();
 466 #endif
 467 #ifdef CONFIG_JFFS2_RTIME
 468         jffs2_rtime_exit();
 469 #endif
 470 #ifdef CONFIG_JFFS2_ZLIB
 471         jffs2_zlib_exit();
 472 #endif
 473         return 0;
 474 }