drivers/mtd/inftlmount.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * inftlmount.c -- INFTL mount code with extensive checks.
   4  *
   5  * Author: Greg Ungerer (gerg@snapgear.com)
   6  * Copyright © 2002-2003, Greg Ungerer (gerg@snapgear.com)
   7  *
   8  * Based heavily on the nftlmount.c code which is:
   9  * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
  10  * Copyright © 2000 Netgem S.A.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <asm/errno.h>
  16 #include <asm/io.h>
  17 #include <linux/uaccess.h>
  18 #include <linux/delay.h>
  19 #include <linux/slab.h>
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/nftl.h>
  22 #include <linux/mtd/inftl.h>
  23
  24 /*
  25  * find_boot_record: Find the INFTL Media Header and its Spare copy which
  26  *      contains the various device information of the INFTL partition and
  27  *      Bad Unit Table. Update the PUtable[] table according to the Bad
  28  *      Unit Table. PUtable[] is used for management of Erase Unit in
  29  *      other routines in inftlcore.c and inftlmount.c.
  30  */
  31 static int find_boot_record(struct INFTLrecord *inftl)
  32 {
  33         struct inftl_unittail h1;
  34         //struct inftl_oob oob;
  35         unsigned int i, block;
  36         u8 buf[SECTORSIZE];
  37         struct INFTLMediaHeader *mh = &inftl->MediaHdr;
  38         struct mtd_info *mtd = inftl->mbd.mtd;
  39         struct INFTLPartition *ip;
  40         size_t retlen;
  41
  42         pr_debug("INFTL: find_boot_record(inftl=%p)\n", inftl);
  43
  44         /*
  45          * Assume logical EraseSize == physical erasesize for starting the
  46          * scan. We'll sort it out later if we find a MediaHeader which says
  47          * otherwise.
  48          */
  49         inftl->EraseSize = inftl->mbd.mtd->erasesize;
  50         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
  51
  52         inftl->MediaUnit = BLOCK_NIL;
  53
  54         /* Search for a valid boot record */
  55         for (block = 0; block < inftl->nb_blocks; block++) {
  56                 int ret;
  57
  58                 /*
  59                  * Check for BNAND header first. Then whinge if it's found
  60                  * but later checks fail.
  61                  */
  62                 ret = mtd_read(mtd, block * inftl->EraseSize, SECTORSIZE,
  63                                &retlen, buf);
  64                 /* We ignore ret in case the ECC of the MediaHeader is invalid
  65                    (which is apparently acceptable) */
  66                 if (retlen != SECTORSIZE) {
  67                         static int warncount = 5;
  68
  69                         if (warncount) {
  70                                 printk(KERN_WARNING "INFTL: block read at 0x%x "
  71                                         "of mtd%d failed: %d\n",
  72                                         block * inftl->EraseSize,
  73                                         inftl->mbd.mtd->index, ret);
  74                                 if (!--warncount)
  75                                         printk(KERN_WARNING "INFTL: further "
  76                                                 "failures for this block will "
  77                                                 "not be printed\n");
  78                         }
  79                         continue;
  80                 }
  81
  82                 if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
  83                         /* BNAND\0 not found. Continue */
  84                         continue;
  85                 }
  86
  87                 /* To be safer with BIOS, also use erase mark as discriminant */
  88                 ret = inftl_read_oob(mtd,
  89                                      block * inftl->EraseSize + SECTORSIZE + 8,
  90                                      8, &retlen,(char *)&h1);
  91                 if (ret < 0) {
  92                         printk(KERN_WARNING "INFTL: ANAND header found at "
  93                                 "0x%x in mtd%d, but OOB data read failed "
  94                                 "(err %d)\n", block * inftl->EraseSize,
  95                                 inftl->mbd.mtd->index, ret);
  96                         continue;
  97                 }
  98
  99
 100                 /*
 101                  * This is the first we've seen.
 102                  * Copy the media header structure into place.
 103                  */
 104                 memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
 105
 106                 /* Read the spare media header at offset 4096 */
 107                 mtd_read(mtd, block * inftl->EraseSize + 4096, SECTORSIZE,
 108                          &retlen, buf);
 109                 if (retlen != SECTORSIZE) {
 110                         printk(KERN_WARNING "INFTL: Unable to read spare "
 111                                "Media Header\n");
 112                         return -1;
 113                 }
 114                 /* Check if this one is the same as the first one we found. */
 115                 if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
 116                         printk(KERN_WARNING "INFTL: Primary and spare Media "
 117                                "Headers disagree.\n");
 118                         return -1;
 119                 }
 120
 121                 mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
 122                 mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
 123                 mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
 124                 mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
 125                 mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
 126                 mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
 127
 128                 pr_debug("INFTL: Media Header ->\n"
 129                          "    bootRecordID          = %s\n"
 130                          "    NoOfBootImageBlocks   = %d\n"
 131                          "    NoOfBinaryPartitions  = %d\n"
 132                          "    NoOfBDTLPartitions    = %d\n"
 133                          "    BlockMultiplierBits   = %d\n"
 134                          "    FormatFlgs            = %d\n"
 135                          "    OsakVersion           = 0x%x\n"
 136                          "    PercentUsed           = %d\n",
 137                          mh->bootRecordID, mh->NoOfBootImageBlocks,
 138                          mh->NoOfBinaryPartitions,
 139                          mh->NoOfBDTLPartitions,
 140                          mh->BlockMultiplierBits, mh->FormatFlags,
 141                          mh->OsakVersion, mh->PercentUsed);
 142
 143                 if (mh->NoOfBDTLPartitions == 0) {
 144                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 145                                 "failed: NoOfBDTLPartitions (%d) == 0, "
 146                                 "must be at least 1\n", mh->NoOfBDTLPartitions);
 147                         return -1;
 148                 }
 149
 150                 if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
 151                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 152                                 "failed: Total Partitions (%d) > 4, "
 153                                 "BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
 154                                 mh->NoOfBinaryPartitions,
 155                                 mh->NoOfBDTLPartitions,
 156                                 mh->NoOfBinaryPartitions);
 157                         return -1;
 158                 }
 159
 160                 if (mh->BlockMultiplierBits > 1) {
 161                         printk(KERN_WARNING "INFTL: sorry, we don't support "
 162                                 "UnitSizeFactor 0x%02x\n",
 163                                 mh->BlockMultiplierBits);
 164                         return -1;
 165                 } else if (mh->BlockMultiplierBits == 1) {
 166                         printk(KERN_WARNING "INFTL: support for INFTL with "
 167                                 "UnitSizeFactor 0x%02x is experimental\n",
 168                                 mh->BlockMultiplierBits);
 169                         inftl->EraseSize = inftl->mbd.mtd->erasesize <<
 170                                 mh->BlockMultiplierBits;
 171                         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
 172                         block >>= mh->BlockMultiplierBits;
 173                 }
 174
 175                 /* Scan the partitions */
 176                 for (i = 0; (i < 4); i++) {
 177                         ip = &mh->Partitions[i];
 178                         ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
 179                         ip->firstUnit = le32_to_cpu(ip->firstUnit);
 180                         ip->lastUnit = le32_to_cpu(ip->lastUnit);
 181                         ip->flags = le32_to_cpu(ip->flags);
 182                         ip->spareUnits = le32_to_cpu(ip->spareUnits);
 183                         ip->Reserved0 = le32_to_cpu(ip->Reserved0);
 184
 185                         pr_debug("    PARTITION[%d] ->\n"
 186                                  "        virtualUnits    = %d\n"
 187                                  "        firstUnit       = %d\n"
 188                                  "        lastUnit        = %d\n"
 189                                  "        flags           = 0x%x\n"
 190                                  "        spareUnits      = %d\n",
 191                                  i, ip->virtualUnits, ip->firstUnit,
 192                                  ip->lastUnit, ip->flags,
 193                                  ip->spareUnits);
 194
 195                         if (ip->Reserved0 != ip->firstUnit) {
 196                                 struct erase_info *instr = &inftl->instr;
 197
 198                                 /*
 199                                  *      Most likely this is using the
 200                                  *      undocumented qiuck mount feature.
 201                                  *      We don't support that, we will need
 202                                  *      to erase the hidden block for full
 203                                  *      compatibility.
 204                                  */
 205                                 instr->addr = ip->Reserved0 * inftl->EraseSize;
 206                                 instr->len = inftl->EraseSize;
 207                                 mtd_erase(mtd, instr);
 208                         }
 209                         if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
 210                                 printk(KERN_WARNING "INFTL: Media Header "
 211                                         "Partition %d sanity check failed\n"
 212                                         "    firstUnit %d : lastUnit %d  >  "
 213                                         "virtualUnits %d\n", i, ip->lastUnit,
 214                                         ip->firstUnit, ip->Reserved0);
 215                                 return -1;
 216                         }
 217                         if (ip->Reserved1 != 0) {
 218                                 printk(KERN_WARNING "INFTL: Media Header "
 219                                         "Partition %d sanity check failed: "
 220                                         "Reserved1 %d != 0\n",
 221                                         i, ip->Reserved1);
 222                                 return -1;
 223                         }
 224
 225                         if (ip->flags & INFTL_BDTL)
 226                                 break;
 227                 }
 228
 229                 if (i >= 4) {
 230                         printk(KERN_WARNING "INFTL: Media Header Partition "
 231                                 "sanity check failed:\n       No partition "
 232                                 "marked as Disk Partition\n");
 233                         return -1;
 234                 }
 235
 236                 inftl->nb_boot_blocks = ip->firstUnit;
 237                 inftl->numvunits = ip->virtualUnits;
 238                 if (inftl->numvunits > (inftl->nb_blocks -
 239                     inftl->nb_boot_blocks - 2)) {
 240                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 241                                 "failed:\n        numvunits (%d) > nb_blocks "
 242                                 "(%d) - nb_boot_blocks(%d) - 2\n",
 243                                 inftl->numvunits, inftl->nb_blocks,
 244                                 inftl->nb_boot_blocks);
 245                         return -1;
 246                 }
 247
 248                 inftl->mbd.size  = inftl->numvunits *
 249                         (inftl->EraseSize / SECTORSIZE);
 250
 251                 /*
 252                  * Block count is set to last used EUN (we won't need to keep
 253                  * any meta-data past that point).
 254                  */
 255                 inftl->firstEUN = ip->firstUnit;
 256                 inftl->lastEUN = ip->lastUnit;
 257                 inftl->nb_blocks = ip->lastUnit + 1;
 258
 259                 /* Memory alloc */
 260                 inftl->PUtable = kmalloc_array(inftl->nb_blocks, sizeof(u16),
 261                                                GFP_KERNEL);
 262                 if (!inftl->PUtable) {
 263                         printk(KERN_WARNING "INFTL: allocation of PUtable "
 264                                 "failed (%zd bytes)\n",
 265                                 inftl->nb_blocks * sizeof(u16));
 266                         return -ENOMEM;
 267                 }
 268
 269                 inftl->VUtable = kmalloc_array(inftl->nb_blocks, sizeof(u16),
 270                                                GFP_KERNEL);
 271                 if (!inftl->VUtable) {
 272                         kfree(inftl->PUtable);
 273                         printk(KERN_WARNING "INFTL: allocation of VUtable "
 274                                 "failed (%zd bytes)\n",
 275                                 inftl->nb_blocks * sizeof(u16));
 276                         return -ENOMEM;
 277                 }
 278
 279                 /* Mark the blocks before INFTL MediaHeader as reserved */
 280                 for (i = 0; i < inftl->nb_boot_blocks; i++)
 281                         inftl->PUtable[i] = BLOCK_RESERVED;
 282                 /* Mark all remaining blocks as potentially containing data */
 283                 for (; i < inftl->nb_blocks; i++)
 284                         inftl->PUtable[i] = BLOCK_NOTEXPLORED;
 285
 286                 /* Mark this boot record (NFTL MediaHeader) block as reserved */
 287                 inftl->PUtable[block] = BLOCK_RESERVED;
 288
 289                 /* Read Bad Erase Unit Table and modify PUtable[] accordingly */
 290                 for (i = 0; i < inftl->nb_blocks; i++) {
 291                         int physblock;
 292                         /* If any of the physical eraseblocks are bad, don't
 293                            use the unit. */
 294                         for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
 295                                 if (mtd_block_isbad(inftl->mbd.mtd,
 296                                                     i * inftl->EraseSize + physblock))
 297                                         inftl->PUtable[i] = BLOCK_RESERVED;
 298                         }
 299                 }
 300
 301                 inftl->MediaUnit = block;
 302                 return 0;
 303         }
 304
 305         /* Not found. */
 306         return -1;
 307 }
 308
 309 static int memcmpb(void *a, int c, int n)
 310 {
 311         int i;
 312         for (i = 0; i < n; i++) {
 313                 if (c != ((unsigned char *)a)[i])
 314                         return 1;
 315         }
 316         return 0;
 317 }
 318
 319 /*
 320  * check_free_sector: check if a free sector is actually FREE,
 321  *      i.e. All 0xff in data and oob area.
 322  */
 323 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
 324         int len, int check_oob)
 325 {
 326         struct mtd_info *mtd = inftl->mbd.mtd;
 327         size_t retlen;
 328         int i, ret;
 329         u8 *buf;
 330
 331         buf = kmalloc(SECTORSIZE + mtd->oobsize, GFP_KERNEL);
 332         if (!buf)
 333                 return -1;
 334
 335         ret = -1;
 336         for (i = 0; i < len; i += SECTORSIZE) {
 337                 if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
 338                         goto out;
 339                 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
 340                         goto out;
 341
 342                 if (check_oob) {
 343                         if(inftl_read_oob(mtd, address, mtd->oobsize,
 344                                           &retlen, &buf[SECTORSIZE]) < 0)
 345                                 goto out;
 346                         if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
 347                                 goto out;
 348                 }
 349                 address += SECTORSIZE;
 350         }
 351
 352         ret = 0;
 353
 354 out:
 355         kfree(buf);
 356         return ret;
 357 }
 358
 359 /*
 360  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
 361  *               Unit and Update INFTL metadata. Each erase operation is
 362  *               checked with check_free_sectors.
 363  *
 364  * Return: 0 when succeed, -1 on error.
 365  *
 366  * ToDo: 1. Is it necessary to check_free_sector after erasing ??
 367  */
 368 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
 369 {
 370         size_t retlen;
 371         struct inftl_unittail uci;
 372         struct erase_info *instr = &inftl->instr;
 373         struct mtd_info *mtd = inftl->mbd.mtd;
 374         int physblock;
 375
 376         pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);
 377
 378         memset(instr, 0, sizeof(struct erase_info));
 379
 380         /* FIXME: Shouldn't we be setting the 'discarded' flag to zero
 381            _first_? */
 382
 383         /* Use async erase interface, test return code */
 384         instr->addr = block * inftl->EraseSize;
 385         instr->len = inftl->mbd.mtd->erasesize;
 386         /* Erase one physical eraseblock at a time, even though the NAND api
 387            allows us to group them.  This way we if we have a failure, we can
 388            mark only the failed block in the bbt. */
 389         for (physblock = 0; physblock < inftl->EraseSize;
 390              physblock += instr->len, instr->addr += instr->len) {
 391                 int ret;
 392
 393                 ret = mtd_erase(inftl->mbd.mtd, instr);
 394                 if (ret) {
 395                         printk(KERN_WARNING "INFTL: error while formatting block %d\n",
 396                                 block);
 397                         goto fail;
 398                 }
 399
 400                 /*
 401                  * Check the "freeness" of Erase Unit before updating metadata.
 402                  * FixMe: is this check really necessary? Since we have check
 403                  * the return code after the erase operation.
 404                  */
 405                 if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
 406                         goto fail;
 407         }
 408
 409         uci.EraseMark = cpu_to_le16(ERASE_MARK);
 410         uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
 411         uci.Reserved[0] = 0;
 412         uci.Reserved[1] = 0;
 413         uci.Reserved[2] = 0;
 414         uci.Reserved[3] = 0;
 415         instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
 416         if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
 417                 goto fail;
 418         return 0;
 419 fail:
 420         /* could not format, update the bad block table (caller is responsible
 421            for setting the PUtable to BLOCK_RESERVED on failure) */
 422         mtd_block_markbad(inftl->mbd.mtd, instr->addr);
 423         return -1;
 424 }
 425
 426 /*
 427  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
 428  *      Units in a Virtual Unit Chain, i.e. all the units are disconnected.
 429  *
 430  *      Since the chain is invalid then we will have to erase it from its
 431  *      head (normally for INFTL we go from the oldest). But if it has a
 432  *      loop then there is no oldest...
 433  */
 434 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
 435 {
 436         unsigned int block = first_block, block1;
 437
 438         printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
 439                 first_block);
 440
 441         for (;;) {
 442                 block1 = inftl->PUtable[block];
 443
 444                 printk(KERN_WARNING "INFTL: formatting block %d\n", block);
 445                 if (INFTL_formatblock(inftl, block) < 0) {
 446                         /*
 447                          * Cannot format !!!! Mark it as Bad Unit,
 448                          */
 449                         inftl->PUtable[block] = BLOCK_RESERVED;
 450                 } else {
 451                         inftl->PUtable[block] = BLOCK_FREE;
 452                 }
 453
 454                 /* Goto next block on the chain */
 455                 block = block1;
 456
 457                 if (block == BLOCK_NIL || block >= inftl->lastEUN)
 458                         break;
 459         }
 460 }
 461
 462 void INFTL_dumptables(struct INFTLrecord *s)
 463 {
 464         int i;
 465
 466         pr_debug("-------------------------------------------"
 467                 "----------------------------------\n");
 468
 469         pr_debug("VUtable[%d] ->", s->nb_blocks);
 470         for (i = 0; i < s->nb_blocks; i++) {
 471                 if ((i % 8) == 0)
 472                         pr_debug("\n%04x: ", i);
 473                 pr_debug("%04x ", s->VUtable[i]);
 474         }
 475
 476         pr_debug("\n-------------------------------------------"
 477                 "----------------------------------\n");
 478
 479         pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
 480         for (i = 0; i <= s->lastEUN; i++) {
 481                 if ((i % 8) == 0)
 482                         pr_debug("\n%04x: ", i);
 483                 pr_debug("%04x ", s->PUtable[i]);
 484         }
 485
 486         pr_debug("\n-------------------------------------------"
 487                 "----------------------------------\n");
 488
 489         pr_debug("INFTL ->\n"
 490                 "  EraseSize       = %d\n"
 491                 "  h/s/c           = %d/%d/%d\n"
 492                 "  numvunits       = %d\n"
 493                 "  firstEUN        = %d\n"
 494                 "  lastEUN         = %d\n"
 495                 "  numfreeEUNs     = %d\n"
 496                 "  LastFreeEUN     = %d\n"
 497                 "  nb_blocks       = %d\n"
 498                 "  nb_boot_blocks  = %d",
 499                 s->EraseSize, s->heads, s->sectors, s->cylinders,
 500                 s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
 501                 s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
 502
 503         pr_debug("\n-------------------------------------------"
 504                 "----------------------------------\n");
 505 }
 506
 507 void INFTL_dumpVUchains(struct INFTLrecord *s)
 508 {
 509         int logical, block, i;
 510
 511         pr_debug("-------------------------------------------"
 512                 "----------------------------------\n");
 513
 514         pr_debug("INFTL Virtual Unit Chains:\n");
 515         for (logical = 0; logical < s->nb_blocks; logical++) {
 516                 block = s->VUtable[logical];
 517                 if (block >= s->nb_blocks)
 518                         continue;
 519                 pr_debug("  LOGICAL %d --> %d ", logical, block);
 520                 for (i = 0; i < s->nb_blocks; i++) {
 521                         if (s->PUtable[block] == BLOCK_NIL)
 522                                 break;
 523                         block = s->PUtable[block];
 524                         pr_debug("%d ", block);
 525                 }
 526                 pr_debug("\n");
 527         }
 528
 529         pr_debug("-------------------------------------------"
 530                 "----------------------------------\n");
 531 }
 532
 533 int INFTL_mount(struct INFTLrecord *s)
 534 {
 535         struct mtd_info *mtd = s->mbd.mtd;
 536         unsigned int block, first_block, prev_block, last_block;
 537         unsigned int first_logical_block, logical_block, erase_mark;
 538         int chain_length, do_format_chain;
 539         struct inftl_unithead1 h0;
 540         struct inftl_unittail h1;
 541         size_t retlen;
 542         int i;
 543         u8 *ANACtable, ANAC;
 544
 545         pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);
 546
 547         /* Search for INFTL MediaHeader and Spare INFTL Media Header */
 548         if (find_boot_record(s) < 0) {
 549                 printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
 550                 return -ENXIO;
 551         }
 552
 553         /* Init the logical to physical table */
 554         for (i = 0; i < s->nb_blocks; i++)
 555                 s->VUtable[i] = BLOCK_NIL;
 556
 557         logical_block = block = BLOCK_NIL;
 558
 559         /* Temporary buffer to store ANAC numbers. */
 560         ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
 561         if (!ANACtable) {
 562                 printk(KERN_WARNING "INFTL: allocation of ANACtable "
 563                                 "failed (%zd bytes)\n",
 564                                 s->nb_blocks * sizeof(u8));
 565                 return -ENOMEM;
 566         }
 567
 568         /*
 569          * First pass is to explore each physical unit, and construct the
 570          * virtual chains that exist (newest physical unit goes into VUtable).
 571          * Any block that is in any way invalid will be left in the
 572          * NOTEXPLORED state. Then at the end we will try to format it and
 573          * mark it as free.
 574          */
 575         pr_debug("INFTL: pass 1, explore each unit\n");
 576         for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
 577                 if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
 578                         continue;
 579
 580                 do_format_chain = 0;
 581                 first_logical_block = BLOCK_NIL;
 582                 last_block = BLOCK_NIL;
 583                 block = first_block;
 584
 585                 for (chain_length = 0; ; chain_length++) {
 586
 587                         if ((chain_length == 0) &&
 588                             (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
 589                                 /* Nothing to do here, onto next block */
 590                                 break;
 591                         }
 592
 593                         if (inftl_read_oob(mtd, block * s->EraseSize + 8,
 594                                            8, &retlen, (char *)&h0) < 0 ||
 595                             inftl_read_oob(mtd, block * s->EraseSize +
 596                                            2 * SECTORSIZE + 8, 8, &retlen,
 597                                            (char *)&h1) < 0) {
 598                                 /* Should never happen? */
 599                                 do_format_chain++;
 600                                 break;
 601                         }
 602
 603                         logical_block = le16_to_cpu(h0.virtualUnitNo);
 604                         prev_block = le16_to_cpu(h0.prevUnitNo);
 605                         erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
 606                         ANACtable[block] = h0.ANAC;
 607
 608                         /* Previous block is relative to start of Partition */
 609                         if (prev_block < s->nb_blocks)
 610                                 prev_block += s->firstEUN;
 611
 612                         /* Already explored partial chain? */
 613                         if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
 614                                 /* Check if chain for this logical */
 615                                 if (logical_block == first_logical_block) {
 616                                         if (last_block != BLOCK_NIL)
 617                                                 s->PUtable[last_block] = block;
 618                                 }
 619                                 break;
 620                         }
 621
 622                         /* Check for invalid block */
 623                         if (erase_mark != ERASE_MARK) {
 624                                 printk(KERN_WARNING "INFTL: corrupt block %d "
 625                                         "in chain %d, chain length %d, erase "
 626                                         "mark 0x%x?\n", block, first_block,
 627                                         chain_length, erase_mark);
 628                                 /*
 629                                  * Assume end of chain, probably incomplete
 630                                  * fold/erase...
 631                                  */
 632                                 if (chain_length == 0)
 633                                         do_format_chain++;
 634                                 break;
 635                         }
 636
 637                         /* Check for it being free already then... */
 638                         if ((logical_block == BLOCK_FREE) ||
 639                             (logical_block == BLOCK_NIL)) {
 640                                 s->PUtable[block] = BLOCK_FREE;
 641                                 break;
 642                         }
 643
 644                         /* Sanity checks on block numbers */
 645                         if ((logical_block >= s->nb_blocks) ||
 646                             ((prev_block >= s->nb_blocks) &&
 647                              (prev_block != BLOCK_NIL))) {
 648                                 if (chain_length > 0) {
 649                                         printk(KERN_WARNING "INFTL: corrupt "
 650                                                 "block %d in chain %d?\n",
 651                                                 block, first_block);
 652                                         do_format_chain++;
 653                                 }
 654                                 break;
 655                         }
 656
 657                         if (first_logical_block == BLOCK_NIL) {
 658                                 first_logical_block = logical_block;
 659                         } else {
 660                                 if (first_logical_block != logical_block) {
 661                                         /* Normal for folded chain... */
 662                                         break;
 663                                 }
 664                         }
 665
 666                         /*
 667                          * Current block is valid, so if we followed a virtual
 668                          * chain to get here then we can set the previous
 669                          * block pointer in our PUtable now. Then move onto
 670                          * the previous block in the chain.
 671                          */
 672                         s->PUtable[block] = BLOCK_NIL;
 673                         if (last_block != BLOCK_NIL)
 674                                 s->PUtable[last_block] = block;
 675                         last_block = block;
 676                         block = prev_block;
 677
 678                         /* Check for end of chain */
 679                         if (block == BLOCK_NIL)
 680                                 break;
 681
 682                         /* Validate next block before following it... */
 683                         if (block > s->lastEUN) {
 684                                 printk(KERN_WARNING "INFTL: invalid previous "
 685                                         "block %d in chain %d?\n", block,
 686                                         first_block);
 687                                 do_format_chain++;
 688                                 break;
 689                         }
 690                 }
 691
 692                 if (do_format_chain) {
 693                         format_chain(s, first_block);
 694                         continue;
 695                 }
 696
 697                 /*
 698                  * Looks like a valid chain then. It may not really be the
 699                  * newest block in the chain, but it is the newest we have
 700                  * found so far. We might update it in later iterations of
 701                  * this loop if we find something newer.
 702                  */
 703                 s->VUtable[first_logical_block] = first_block;
 704                 logical_block = BLOCK_NIL;
 705         }
 706
 707         INFTL_dumptables(s);
 708
 709         /*
 710          * Second pass, check for infinite loops in chains. These are
 711          * possible because we don't update the previous pointers when
 712          * we fold chains. No big deal, just fix them up in PUtable.
 713          */
 714         pr_debug("INFTL: pass 2, validate virtual chains\n");
 715         for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
 716                 block = s->VUtable[logical_block];
 717                 last_block = BLOCK_NIL;
 718
 719                 /* Check for free/reserved/nil */
 720                 if (block >= BLOCK_RESERVED)
 721                         continue;
 722
 723                 ANAC = ANACtable[block];
 724                 for (i = 0; i < s->numvunits; i++) {
 725                         if (s->PUtable[block] == BLOCK_NIL)
 726                                 break;
 727                         if (s->PUtable[block] > s->lastEUN) {
 728                                 printk(KERN_WARNING "INFTL: invalid prev %d, "
 729                                         "in virtual chain %d\n",
 730                                         s->PUtable[block], logical_block);
 731                                 s->PUtable[block] = BLOCK_NIL;
 732
 733                         }
 734                         if (ANACtable[block] != ANAC) {
 735                                 /*
 736                                  * Chain must point back to itself. This is ok,
 737                                  * but we will need adjust the tables with this
 738                                  * newest block and oldest block.
 739                                  */
 740                                 s->VUtable[logical_block] = block;
 741                                 s->PUtable[last_block] = BLOCK_NIL;
 742                                 break;
 743                         }
 744
 745                         ANAC--;
 746                         last_block = block;
 747                         block = s->PUtable[block];
 748                 }
 749
 750                 if (i >= s->nb_blocks) {
 751                         /*
 752                          * Uhoo, infinite chain with valid ANACS!
 753                          * Format whole chain...
 754                          */
 755                         format_chain(s, first_block);
 756                 }
 757         }
 758
 759         INFTL_dumptables(s);
 760         INFTL_dumpVUchains(s);
 761
 762         /*
 763          * Third pass, format unreferenced blocks and init free block count.
 764          */
 765         s->numfreeEUNs = 0;
 766         s->LastFreeEUN = BLOCK_NIL;
 767
 768         pr_debug("INFTL: pass 3, format unused blocks\n");
 769         for (block = s->firstEUN; block <= s->lastEUN; block++) {
 770                 if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
 771                         printk("INFTL: unreferenced block %d, formatting it\n",
 772                                 block);
 773                         if (INFTL_formatblock(s, block) < 0)
 774                                 s->PUtable[block] = BLOCK_RESERVED;
 775                         else
 776                                 s->PUtable[block] = BLOCK_FREE;
 777                 }
 778                 if (s->PUtable[block] == BLOCK_FREE) {
 779                         s->numfreeEUNs++;
 780                         if (s->LastFreeEUN == BLOCK_NIL)
 781                                 s->LastFreeEUN = block;
 782                 }
 783         }
 784
 785         kfree(ANACtable);
 786         return 0;
 787 }