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 1.42 2004/08/07 21:56:08 dwmw2 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 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         /* Older code had a bug where it would write non-zero 'usercompr'
 184            fields. Deal with it. */
 185         if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
 186                 comprtype &= 0xff;
 187
 188         switch (comprtype & 0xff) {
 189         case JFFS2_COMPR_NONE:
 190                 /* This should be special-cased elsewhere, but we might as well deal with it */
 191                 memcpy(data_out, cdata_in, datalen);
 192                 none_stat_decompr_blocks++;
 193                 break;
 194         case JFFS2_COMPR_ZERO:
 195                 memset(data_out, 0, datalen);
 196                 break;
 197         default:
 198                 spin_lock(&jffs2_compressor_list_lock);
 199                 list_for_each_entry(this, &jffs2_compressor_list, list) {
 200                         if (comprtype == this->compr) {
 201                                 this->usecount++;
 202                                 spin_unlock(&jffs2_compressor_list_lock);
 203                                 ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL);
 204                                 spin_lock(&jffs2_compressor_list_lock);
 205                                 if (ret) {
 206                                         printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
 207                                 }
 208                                 else {
 209                                         this->stat_decompr_blocks++;
 210                                 }
 211                                 this->usecount--;
 212                                 spin_unlock(&jffs2_compressor_list_lock);
 213                                 return ret;
 214                         }
 215                 }
 216                 printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype);
 217                 spin_unlock(&jffs2_compressor_list_lock);
 218                 return -EIO;
 219         }
 220         return 0;
 221 }
 222
 223 int jffs2_register_compressor(struct jffs2_compressor *comp)
 224 {
 225         struct jffs2_compressor *this;
 226
 227         if (!comp->name) {
 228                 printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n");
 229                 return -1;
 230         }
 231         comp->compr_buf_size=0;
 232         comp->compr_buf=NULL;
 233         comp->usecount=0;
 234         comp->stat_compr_orig_size=0;
 235         comp->stat_compr_new_size=0;
 236         comp->stat_compr_blocks=0;
 237         comp->stat_decompr_blocks=0;
 238         D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));
 239
 240         spin_lock(&jffs2_compressor_list_lock);
 241
 242         list_for_each_entry(this, &jffs2_compressor_list, list) {
 243                 if (this->priority < comp->priority) {
 244                         list_add(&comp->list, this->list.prev);
 245                         goto out;
 246                 }
 247         }
 248         list_add_tail(&comp->list, &jffs2_compressor_list);
 249 out:
 250         D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
 251                 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
 252         })
 253
 254         spin_unlock(&jffs2_compressor_list_lock);
 255
 256         return 0;
 257 }
 258
 259 int jffs2_unregister_compressor(struct jffs2_compressor *comp)
 260 {
 261         D2(struct jffs2_compressor *this;)
 262
 263         D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));
 264
 265         spin_lock(&jffs2_compressor_list_lock);
 266
 267         if (comp->usecount) {
 268                 spin_unlock(&jffs2_compressor_list_lock);
 269                 printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
 270                 return -1;
 271         }
 272         list_del(&comp->list);
 273
 274         D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
 275                 printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
 276         })
 277         spin_unlock(&jffs2_compressor_list_lock);
 278         return 0;
 279 }
 280
 281 #ifdef CONFIG_JFFS2_PROC
 282
 283 #define JFFS2_STAT_BUF_SIZE 16000
 284
 285 char *jffs2_list_compressors(void)
 286 {
 287         struct jffs2_compressor *this;
 288         char *buf, *act_buf;
 289
 290         act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
 291         list_for_each_entry(this, &jffs2_compressor_list, list) {
 292                 act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority);
 293                 if ((this->disabled)||(!this->compress))
 294                         act_buf += sprintf(act_buf,"disabled");
 295                 else
 296                         act_buf += sprintf(act_buf,"enabled");
 297                 act_buf += sprintf(act_buf,"\n");
 298         }
 299         return buf;
 300 }
 301
 302 char *jffs2_stats(void)
 303 {
 304         struct jffs2_compressor *this;
 305         char *buf, *act_buf;
 306
 307         act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
 308
 309         act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n");
 310         act_buf += sprintf(act_buf,"%10s   ","none");
 311         act_buf += sprintf(act_buf,"compr: %d blocks (%d)  decompr: %d blocks\n", none_stat_compr_blocks,
 312                            none_stat_compr_size, none_stat_decompr_blocks);
 313         spin_lock(&jffs2_compressor_list_lock);
 314         list_for_each_entry(this, &jffs2_compressor_list, list) {
 315                 act_buf += sprintf(act_buf,"%10s ",this->name);
 316                 if ((this->disabled)||(!this->compress))
 317                         act_buf += sprintf(act_buf,"- ");
 318                 else
 319                         act_buf += sprintf(act_buf,"+ ");
 320                 act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d)  decompr: %d blocks ", this->stat_compr_blocks,
 321                                    this->stat_compr_new_size, this->stat_compr_orig_size,
 322                                    this->stat_decompr_blocks);
 323                 act_buf += sprintf(act_buf,"\n");
 324         }
 325         spin_unlock(&jffs2_compressor_list_lock);
 326
 327         return buf;
 328 }
 329
 330 char *jffs2_get_compression_mode_name(void)
 331 {
 332         switch (jffs2_compression_mode) {
 333         case JFFS2_COMPR_MODE_NONE:
 334                 return "none";
 335         case JFFS2_COMPR_MODE_PRIORITY:
 336                 return "priority";
 337         case JFFS2_COMPR_MODE_SIZE:
 338                 return "size";
 339         }
 340         return "unkown";
 341 }
 342
 343 int jffs2_set_compression_mode_name(const char *name)
 344 {
 345         if (!strcmp("none",name)) {
 346                 jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
 347                 return 0;
 348         }
 349         if (!strcmp("priority",name)) {
 350                 jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
 351                 return 0;
 352         }
 353         if (!strcmp("size",name)) {
 354                 jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
 355                 return 0;
 356         }
 357         return 1;
 358 }
 359
 360 static int jffs2_compressor_Xable(const char *name, int disabled)
 361 {
 362         struct jffs2_compressor *this;
 363         spin_lock(&jffs2_compressor_list_lock);
 364         list_for_each_entry(this, &jffs2_compressor_list, list) {
 365                 if (!strcmp(this->name, name)) {
 366                         this->disabled = disabled;
 367                         spin_unlock(&jffs2_compressor_list_lock);
 368                         return 0;
 369                 }
 370         }
 371         spin_unlock(&jffs2_compressor_list_lock);
 372         printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
 373         return 1;
 374 }
 375
 376 int jffs2_enable_compressor_name(const char *name)
 377 {
 378         return jffs2_compressor_Xable(name, 0);
 379 }
 380
 381 int jffs2_disable_compressor_name(const char *name)
 382 {
 383         return jffs2_compressor_Xable(name, 1);
 384 }
 385
 386 int jffs2_set_compressor_priority(const char *name, int priority)
 387 {
 388         struct jffs2_compressor *this,*comp;
 389         spin_lock(&jffs2_compressor_list_lock);
 390         list_for_each_entry(this, &jffs2_compressor_list, list) {
 391                 if (!strcmp(this->name, name)) {
 392                         this->priority = priority;
 393                         comp = this;
 394                         goto reinsert;
 395                 }
 396         }
 397         spin_unlock(&jffs2_compressor_list_lock);
 398         printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
 399         return 1;
 400 reinsert:
 401         /* list is sorted in the order of priority, so if
 402            we change it we have to reinsert it into the
 403            good place */
 404         list_del(&comp->list);
 405         list_for_each_entry(this, &jffs2_compressor_list, list) {
 406                 if (this->priority < comp->priority) {
 407                         list_add(&comp->list, this->list.prev);
 408                         spin_unlock(&jffs2_compressor_list_lock);
 409                         return 0;
 410                 }
 411         }
 412         list_add_tail(&comp->list, &jffs2_compressor_list);
 413         spin_unlock(&jffs2_compressor_list_lock);
 414         return 0;
 415 }
 416
 417 #endif
 418
 419 void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
 420 {
 421         if (orig != comprbuf)
 422                 kfree(comprbuf);
 423 }
 424
 425 int jffs2_compressors_init(void)
 426 {
 427 /* Registering compressors */
 428 #ifdef CONFIG_JFFS2_ZLIB
 429         jffs2_zlib_init();
 430 #endif
 431 #ifdef CONFIG_JFFS2_RTIME
 432         jffs2_rtime_init();
 433 #endif
 434 #ifdef CONFIG_JFFS2_RUBIN
 435         jffs2_rubinmips_init();
 436         jffs2_dynrubin_init();
 437 #endif
 438 #ifdef CONFIG_JFFS2_LZARI
 439         jffs2_lzari_init();
 440 #endif
 441 #ifdef CONFIG_JFFS2_LZO
 442         jffs2_lzo_init();
 443 #endif
 444 /* Setting default compression mode */
 445 #ifdef CONFIG_JFFS2_CMODE_NONE
 446         jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
 447         D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
 448 #else
 449 #ifdef CONFIG_JFFS2_CMODE_SIZE
 450         jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
 451         D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
 452 #else
 453         D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
 454 #endif
 455 #endif
 456         return 0;
 457 }
 458
 459 int jffs2_compressors_exit(void)
 460 {
 461 /* Unregistering compressors */
 462 #ifdef CONFIG_JFFS2_LZO
 463         jffs2_lzo_exit();
 464 #endif
 465 #ifdef CONFIG_JFFS2_LZARI
 466         jffs2_lzari_exit();
 467 #endif
 468 #ifdef CONFIG_JFFS2_RUBIN
 469         jffs2_dynrubin_exit();
 470         jffs2_rubinmips_exit();
 471 #endif
 472 #ifdef CONFIG_JFFS2_RTIME
 473         jffs2_rtime_exit();
 474 #endif
 475 #ifdef CONFIG_JFFS2_ZLIB
 476         jffs2_zlib_exit();
 477 #endif
 478         return 0;
 479 }