drivers/mtd/inftlmount.c

   1 /*
   2  * inftlmount.c -- INFTL mount code with extensive checks.
   3  *
   4  * Author: Greg Ungerer (gerg@snapgear.com)
   5  * Copyright © 2002-2003, Greg Ungerer (gerg@snapgear.com)
   6  *
   7  * Based heavily on the nftlmount.c code which is:
   8  * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
   9  * Copyright © 2000 Netgem S.A.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <asm/errno.h>
  29 #include <asm/io.h>
  30 #include <asm/uaccess.h>
  31 #include <linux/delay.h>
  32 #include <linux/slab.h>
  33 #include <linux/init.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/nftl.h>
  36 #include <linux/mtd/inftl.h>
  37
  38 /*
  39  * find_boot_record: Find the INFTL Media Header and its Spare copy which
  40  *      contains the various device information of the INFTL partition and
  41  *      Bad Unit Table. Update the PUtable[] table according to the Bad
  42  *      Unit Table. PUtable[] is used for management of Erase Unit in
  43  *      other routines in inftlcore.c and inftlmount.c.
  44  */
  45 static int find_boot_record(struct INFTLrecord *inftl)
  46 {
  47         struct inftl_unittail h1;
  48         //struct inftl_oob oob;
  49         unsigned int i, block;
  50         u8 buf[SECTORSIZE];
  51         struct INFTLMediaHeader *mh = &inftl->MediaHdr;
  52         struct mtd_info *mtd = inftl->mbd.mtd;
  53         struct INFTLPartition *ip;
  54         size_t retlen;
  55
  56         pr_debug("INFTL: find_boot_record(inftl=%p)\n", inftl);
  57
  58         /*
  59          * Assume logical EraseSize == physical erasesize for starting the
  60          * scan. We'll sort it out later if we find a MediaHeader which says
  61          * otherwise.
  62          */
  63         inftl->EraseSize = inftl->mbd.mtd->erasesize;
  64         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
  65
  66         inftl->MediaUnit = BLOCK_NIL;
  67
  68         /* Search for a valid boot record */
  69         for (block = 0; block < inftl->nb_blocks; block++) {
  70                 int ret;
  71
  72                 /*
  73                  * Check for BNAND header first. Then whinge if it's found
  74                  * but later checks fail.
  75                  */
  76                 ret = mtd->read(mtd, block * inftl->EraseSize,
  77                                 SECTORSIZE, &retlen, buf);
  78                 /* We ignore ret in case the ECC of the MediaHeader is invalid
  79                    (which is apparently acceptable) */
  80                 if (retlen != SECTORSIZE) {
  81                         static int warncount = 5;
  82
  83                         if (warncount) {
  84                                 printk(KERN_WARNING "INFTL: block read at 0x%x "
  85                                         "of mtd%d failed: %d\n",
  86                                         block * inftl->EraseSize,
  87                                         inftl->mbd.mtd->index, ret);
  88                                 if (!--warncount)
  89                                         printk(KERN_WARNING "INFTL: further "
  90                                                 "failures for this block will "
  91                                                 "not be printed\n");
  92                         }
  93                         continue;
  94                 }
  95
  96                 if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
  97                         /* BNAND\0 not found. Continue */
  98                         continue;
  99                 }
 100
 101                 /* To be safer with BIOS, also use erase mark as discriminant */
 102                 ret = inftl_read_oob(mtd,
 103                                      block * inftl->EraseSize + SECTORSIZE + 8,
 104                                      8, &retlen,(char *)&h1);
 105                 if (ret < 0) {
 106                         printk(KERN_WARNING "INFTL: ANAND header found at "
 107                                 "0x%x in mtd%d, but OOB data read failed "
 108                                 "(err %d)\n", block * inftl->EraseSize,
 109                                 inftl->mbd.mtd->index, ret);
 110                         continue;
 111                 }
 112
 113
 114                 /*
 115                  * This is the first we've seen.
 116                  * Copy the media header structure into place.
 117                  */
 118                 memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
 119
 120                 /* Read the spare media header at offset 4096 */
 121                 mtd->read(mtd, block * inftl->EraseSize + 4096,
 122                           SECTORSIZE, &retlen, buf);
 123                 if (retlen != SECTORSIZE) {
 124                         printk(KERN_WARNING "INFTL: Unable to read spare "
 125                                "Media Header\n");
 126                         return -1;
 127                 }
 128                 /* Check if this one is the same as the first one we found. */
 129                 if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
 130                         printk(KERN_WARNING "INFTL: Primary and spare Media "
 131                                "Headers disagree.\n");
 132                         return -1;
 133                 }
 134
 135                 mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
 136                 mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
 137                 mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
 138                 mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
 139                 mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
 140                 mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
 141
 142                 pr_debug("INFTL: Media Header ->\n"
 143                          "    bootRecordID          = %s\n"
 144                          "    NoOfBootImageBlocks   = %d\n"
 145                          "    NoOfBinaryPartitions  = %d\n"
 146                          "    NoOfBDTLPartitions    = %d\n"
 147                          "    BlockMultiplerBits    = %d\n"
 148                          "    FormatFlgs            = %d\n"
 149                          "    OsakVersion           = 0x%x\n"
 150                          "    PercentUsed           = %d\n",
 151                          mh->bootRecordID, mh->NoOfBootImageBlocks,
 152                          mh->NoOfBinaryPartitions,
 153                          mh->NoOfBDTLPartitions,
 154                          mh->BlockMultiplierBits, mh->FormatFlags,
 155                          mh->OsakVersion, mh->PercentUsed);
 156
 157                 if (mh->NoOfBDTLPartitions == 0) {
 158                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 159                                 "failed: NoOfBDTLPartitions (%d) == 0, "
 160                                 "must be at least 1\n", mh->NoOfBDTLPartitions);
 161                         return -1;
 162                 }
 163
 164                 if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
 165                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 166                                 "failed: Total Partitions (%d) > 4, "
 167                                 "BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
 168                                 mh->NoOfBinaryPartitions,
 169                                 mh->NoOfBDTLPartitions,
 170                                 mh->NoOfBinaryPartitions);
 171                         return -1;
 172                 }
 173
 174                 if (mh->BlockMultiplierBits > 1) {
 175                         printk(KERN_WARNING "INFTL: sorry, we don't support "
 176                                 "UnitSizeFactor 0x%02x\n",
 177                                 mh->BlockMultiplierBits);
 178                         return -1;
 179                 } else if (mh->BlockMultiplierBits == 1) {
 180                         printk(KERN_WARNING "INFTL: support for INFTL with "
 181                                 "UnitSizeFactor 0x%02x is experimental\n",
 182                                 mh->BlockMultiplierBits);
 183                         inftl->EraseSize = inftl->mbd.mtd->erasesize <<
 184                                 mh->BlockMultiplierBits;
 185                         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
 186                         block >>= mh->BlockMultiplierBits;
 187                 }
 188
 189                 /* Scan the partitions */
 190                 for (i = 0; (i < 4); i++) {
 191                         ip = &mh->Partitions[i];
 192                         ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
 193                         ip->firstUnit = le32_to_cpu(ip->firstUnit);
 194                         ip->lastUnit = le32_to_cpu(ip->lastUnit);
 195                         ip->flags = le32_to_cpu(ip->flags);
 196                         ip->spareUnits = le32_to_cpu(ip->spareUnits);
 197                         ip->Reserved0 = le32_to_cpu(ip->Reserved0);
 198
 199                         pr_debug("    PARTITION[%d] ->\n"
 200                                  "        virtualUnits    = %d\n"
 201                                  "        firstUnit       = %d\n"
 202                                  "        lastUnit        = %d\n"
 203                                  "        flags           = 0x%x\n"
 204                                  "        spareUnits      = %d\n",
 205                                  i, ip->virtualUnits, ip->firstUnit,
 206                                  ip->lastUnit, ip->flags,
 207                                  ip->spareUnits);
 208
 209                         if (ip->Reserved0 != ip->firstUnit) {
 210                                 struct erase_info *instr = &inftl->instr;
 211
 212                                 instr->mtd = inftl->mbd.mtd;
 213
 214                                 /*
 215                                  *      Most likely this is using the
 216                                  *      undocumented qiuck mount feature.
 217                                  *      We don't support that, we will need
 218                                  *      to erase the hidden block for full
 219                                  *      compatibility.
 220                                  */
 221                                 instr->addr = ip->Reserved0 * inftl->EraseSize;
 222                                 instr->len = inftl->EraseSize;
 223                                 mtd->erase(mtd, instr);
 224                         }
 225                         if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
 226                                 printk(KERN_WARNING "INFTL: Media Header "
 227                                         "Partition %d sanity check failed\n"
 228                                         "    firstUnit %d : lastUnit %d  >  "
 229                                         "virtualUnits %d\n", i, ip->lastUnit,
 230                                         ip->firstUnit, ip->Reserved0);
 231                                 return -1;
 232                         }
 233                         if (ip->Reserved1 != 0) {
 234                                 printk(KERN_WARNING "INFTL: Media Header "
 235                                         "Partition %d sanity check failed: "
 236                                         "Reserved1 %d != 0\n",
 237                                         i, ip->Reserved1);
 238                                 return -1;
 239                         }
 240
 241                         if (ip->flags & INFTL_BDTL)
 242                                 break;
 243                 }
 244
 245                 if (i >= 4) {
 246                         printk(KERN_WARNING "INFTL: Media Header Partition "
 247                                 "sanity check failed:\n       No partition "
 248                                 "marked as Disk Partition\n");
 249                         return -1;
 250                 }
 251
 252                 inftl->nb_boot_blocks = ip->firstUnit;
 253                 inftl->numvunits = ip->virtualUnits;
 254                 if (inftl->numvunits > (inftl->nb_blocks -
 255                     inftl->nb_boot_blocks - 2)) {
 256                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 257                                 "failed:\n        numvunits (%d) > nb_blocks "
 258                                 "(%d) - nb_boot_blocks(%d) - 2\n",
 259                                 inftl->numvunits, inftl->nb_blocks,
 260                                 inftl->nb_boot_blocks);
 261                         return -1;
 262                 }
 263
 264                 inftl->mbd.size  = inftl->numvunits *
 265                         (inftl->EraseSize / SECTORSIZE);
 266
 267                 /*
 268                  * Block count is set to last used EUN (we won't need to keep
 269                  * any meta-data past that point).
 270                  */
 271                 inftl->firstEUN = ip->firstUnit;
 272                 inftl->lastEUN = ip->lastUnit;
 273                 inftl->nb_blocks = ip->lastUnit + 1;
 274
 275                 /* Memory alloc */
 276                 inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
 277                 if (!inftl->PUtable) {
 278                         printk(KERN_WARNING "INFTL: allocation of PUtable "
 279                                 "failed (%zd bytes)\n",
 280                                 inftl->nb_blocks * sizeof(u16));
 281                         return -ENOMEM;
 282                 }
 283
 284                 inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
 285                 if (!inftl->VUtable) {
 286                         kfree(inftl->PUtable);
 287                         printk(KERN_WARNING "INFTL: allocation of VUtable "
 288                                 "failed (%zd bytes)\n",
 289                                 inftl->nb_blocks * sizeof(u16));
 290                         return -ENOMEM;
 291                 }
 292
 293                 /* Mark the blocks before INFTL MediaHeader as reserved */
 294                 for (i = 0; i < inftl->nb_boot_blocks; i++)
 295                         inftl->PUtable[i] = BLOCK_RESERVED;
 296                 /* Mark all remaining blocks as potentially containing data */
 297                 for (; i < inftl->nb_blocks; i++)
 298                         inftl->PUtable[i] = BLOCK_NOTEXPLORED;
 299
 300                 /* Mark this boot record (NFTL MediaHeader) block as reserved */
 301                 inftl->PUtable[block] = BLOCK_RESERVED;
 302
 303                 /* Read Bad Erase Unit Table and modify PUtable[] accordingly */
 304                 for (i = 0; i < inftl->nb_blocks; i++) {
 305                         int physblock;
 306                         /* If any of the physical eraseblocks are bad, don't
 307                            use the unit. */
 308                         for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
 309                                 if (inftl->mbd.mtd->block_isbad(inftl->mbd.mtd, i * inftl->EraseSize + physblock))
 310                                         inftl->PUtable[i] = BLOCK_RESERVED;
 311                         }
 312                 }
 313
 314                 inftl->MediaUnit = block;
 315                 return 0;
 316         }
 317
 318         /* Not found. */
 319         return -1;
 320 }
 321
 322 static int memcmpb(void *a, int c, int n)
 323 {
 324         int i;
 325         for (i = 0; i < n; i++) {
 326                 if (c != ((unsigned char *)a)[i])
 327                         return 1;
 328         }
 329         return 0;
 330 }
 331
 332 /*
 333  * check_free_sector: check if a free sector is actually FREE,
 334  *      i.e. All 0xff in data and oob area.
 335  */
 336 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
 337         int len, int check_oob)
 338 {
 339         u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
 340         struct mtd_info *mtd = inftl->mbd.mtd;
 341         size_t retlen;
 342         int i;
 343
 344         for (i = 0; i < len; i += SECTORSIZE) {
 345                 if (mtd->read(mtd, address, SECTORSIZE, &retlen, buf))
 346                         return -1;
 347                 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
 348                         return -1;
 349
 350                 if (check_oob) {
 351                         if(inftl_read_oob(mtd, address, mtd->oobsize,
 352                                           &retlen, &buf[SECTORSIZE]) < 0)
 353                                 return -1;
 354                         if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
 355                                 return -1;
 356                 }
 357                 address += SECTORSIZE;
 358         }
 359
 360         return 0;
 361 }
 362
 363 /*
 364  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
 365  *               Unit and Update INFTL metadata. Each erase operation is
 366  *               checked with check_free_sectors.
 367  *
 368  * Return: 0 when succeed, -1 on error.
 369  *
 370  * ToDo: 1. Is it necessary to check_free_sector after erasing ??
 371  */
 372 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
 373 {
 374         size_t retlen;
 375         struct inftl_unittail uci;
 376         struct erase_info *instr = &inftl->instr;
 377         struct mtd_info *mtd = inftl->mbd.mtd;
 378         int physblock;
 379
 380         pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);
 381
 382         memset(instr, 0, sizeof(struct erase_info));
 383
 384         /* FIXME: Shouldn't we be setting the 'discarded' flag to zero
 385            _first_? */
 386
 387         /* Use async erase interface, test return code */
 388         instr->mtd = inftl->mbd.mtd;
 389         instr->addr = block * inftl->EraseSize;
 390         instr->len = inftl->mbd.mtd->erasesize;
 391         /* Erase one physical eraseblock at a time, even though the NAND api
 392            allows us to group them.  This way we if we have a failure, we can
 393            mark only the failed block in the bbt. */
 394         for (physblock = 0; physblock < inftl->EraseSize;
 395              physblock += instr->len, instr->addr += instr->len) {
 396                 mtd->erase(inftl->mbd.mtd, instr);
 397
 398                 if (instr->state == MTD_ERASE_FAILED) {
 399                         printk(KERN_WARNING "INFTL: error while formatting block %d\n",
 400                                 block);
 401                         goto fail;
 402                 }
 403
 404                 /*
 405                  * Check the "freeness" of Erase Unit before updating metadata.
 406                  * FixMe: is this check really necessary? Since we have check
 407                  * the return code after the erase operation.
 408                  */
 409                 if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
 410                         goto fail;
 411         }
 412
 413         uci.EraseMark = cpu_to_le16(ERASE_MARK);
 414         uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
 415         uci.Reserved[0] = 0;
 416         uci.Reserved[1] = 0;
 417         uci.Reserved[2] = 0;
 418         uci.Reserved[3] = 0;
 419         instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
 420         if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
 421                 goto fail;
 422         return 0;
 423 fail:
 424         /* could not format, update the bad block table (caller is responsible
 425            for setting the PUtable to BLOCK_RESERVED on failure) */
 426         inftl->mbd.mtd->block_markbad(inftl->mbd.mtd, instr->addr);
 427         return -1;
 428 }
 429
 430 /*
 431  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
 432  *      Units in a Virtual Unit Chain, i.e. all the units are disconnected.
 433  *
 434  *      Since the chain is invalid then we will have to erase it from its
 435  *      head (normally for INFTL we go from the oldest). But if it has a
 436  *      loop then there is no oldest...
 437  */
 438 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
 439 {
 440         unsigned int block = first_block, block1;
 441
 442         printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
 443                 first_block);
 444
 445         for (;;) {
 446                 block1 = inftl->PUtable[block];
 447
 448                 printk(KERN_WARNING "INFTL: formatting block %d\n", block);
 449                 if (INFTL_formatblock(inftl, block) < 0) {
 450                         /*
 451                          * Cannot format !!!! Mark it as Bad Unit,
 452                          */
 453                         inftl->PUtable[block] = BLOCK_RESERVED;
 454                 } else {
 455                         inftl->PUtable[block] = BLOCK_FREE;
 456                 }
 457
 458                 /* Goto next block on the chain */
 459                 block = block1;
 460
 461                 if (block == BLOCK_NIL || block >= inftl->lastEUN)
 462                         break;
 463         }
 464 }
 465
 466 void INFTL_dumptables(struct INFTLrecord *s)
 467 {
 468         int i;
 469
 470         pr_debug("-------------------------------------------"
 471                 "----------------------------------\n");
 472
 473         pr_debug("VUtable[%d] ->", s->nb_blocks);
 474         for (i = 0; i < s->nb_blocks; i++) {
 475                 if ((i % 8) == 0)
 476                         pr_debug("\n%04x: ", i);
 477                 pr_debug("%04x ", s->VUtable[i]);
 478         }
 479
 480         pr_debug("\n-------------------------------------------"
 481                 "----------------------------------\n");
 482
 483         pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
 484         for (i = 0; i <= s->lastEUN; i++) {
 485                 if ((i % 8) == 0)
 486                         pr_debug("\n%04x: ", i);
 487                 pr_debug("%04x ", s->PUtable[i]);
 488         }
 489
 490         pr_debug("\n-------------------------------------------"
 491                 "----------------------------------\n");
 492
 493         pr_debug("INFTL ->\n"
 494                 "  EraseSize       = %d\n"
 495                 "  h/s/c           = %d/%d/%d\n"
 496                 "  numvunits       = %d\n"
 497                 "  firstEUN        = %d\n"
 498                 "  lastEUN         = %d\n"
 499                 "  numfreeEUNs     = %d\n"
 500                 "  LastFreeEUN     = %d\n"
 501                 "  nb_blocks       = %d\n"
 502                 "  nb_boot_blocks  = %d",
 503                 s->EraseSize, s->heads, s->sectors, s->cylinders,
 504                 s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
 505                 s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
 506
 507         pr_debug("\n-------------------------------------------"
 508                 "----------------------------------\n");
 509 }
 510
 511 void INFTL_dumpVUchains(struct INFTLrecord *s)
 512 {
 513         int logical, block, i;
 514
 515         pr_debug("-------------------------------------------"
 516                 "----------------------------------\n");
 517
 518         pr_debug("INFTL Virtual Unit Chains:\n");
 519         for (logical = 0; logical < s->nb_blocks; logical++) {
 520                 block = s->VUtable[logical];
 521                 if (block > s->nb_blocks)
 522                         continue;
 523                 pr_debug("  LOGICAL %d --> %d ", logical, block);
 524                 for (i = 0; i < s->nb_blocks; i++) {
 525                         if (s->PUtable[block] == BLOCK_NIL)
 526                                 break;
 527                         block = s->PUtable[block];
 528                         pr_debug("%d ", block);
 529                 }
 530                 pr_debug("\n");
 531         }
 532
 533         pr_debug("-------------------------------------------"
 534                 "----------------------------------\n");
 535 }
 536
 537 int INFTL_mount(struct INFTLrecord *s)
 538 {
 539         struct mtd_info *mtd = s->mbd.mtd;
 540         unsigned int block, first_block, prev_block, last_block;
 541         unsigned int first_logical_block, logical_block, erase_mark;
 542         int chain_length, do_format_chain;
 543         struct inftl_unithead1 h0;
 544         struct inftl_unittail h1;
 545         size_t retlen;
 546         int i;
 547         u8 *ANACtable, ANAC;
 548
 549         pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);
 550
 551         /* Search for INFTL MediaHeader and Spare INFTL Media Header */
 552         if (find_boot_record(s) < 0) {
 553                 printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
 554                 return -ENXIO;
 555         }
 556
 557         /* Init the logical to physical table */
 558         for (i = 0; i < s->nb_blocks; i++)
 559                 s->VUtable[i] = BLOCK_NIL;
 560
 561         logical_block = block = BLOCK_NIL;
 562
 563         /* Temporary buffer to store ANAC numbers. */
 564         ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
 565         if (!ANACtable) {
 566                 printk(KERN_WARNING "INFTL: allocation of ANACtable "
 567                                 "failed (%zd bytes)\n",
 568                                 s->nb_blocks * sizeof(u8));
 569                 return -ENOMEM;
 570         }
 571
 572         /*
 573          * First pass is to explore each physical unit, and construct the
 574          * virtual chains that exist (newest physical unit goes into VUtable).
 575          * Any block that is in any way invalid will be left in the
 576          * NOTEXPLORED state. Then at the end we will try to format it and
 577          * mark it as free.
 578          */
 579         pr_debug("INFTL: pass 1, explore each unit\n");
 580         for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
 581                 if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
 582                         continue;
 583
 584                 do_format_chain = 0;
 585                 first_logical_block = BLOCK_NIL;
 586                 last_block = BLOCK_NIL;
 587                 block = first_block;
 588
 589                 for (chain_length = 0; ; chain_length++) {
 590
 591                         if ((chain_length == 0) &&
 592                             (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
 593                                 /* Nothing to do here, onto next block */
 594                                 break;
 595                         }
 596
 597                         if (inftl_read_oob(mtd, block * s->EraseSize + 8,
 598                                            8, &retlen, (char *)&h0) < 0 ||
 599                             inftl_read_oob(mtd, block * s->EraseSize +
 600                                            2 * SECTORSIZE + 8, 8, &retlen,
 601                                            (char *)&h1) < 0) {
 602                                 /* Should never happen? */
 603                                 do_format_chain++;
 604                                 break;
 605                         }
 606
 607                         logical_block = le16_to_cpu(h0.virtualUnitNo);
 608                         prev_block = le16_to_cpu(h0.prevUnitNo);
 609                         erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
 610                         ANACtable[block] = h0.ANAC;
 611
 612                         /* Previous block is relative to start of Partition */
 613                         if (prev_block < s->nb_blocks)
 614                                 prev_block += s->firstEUN;
 615
 616                         /* Already explored partial chain? */
 617                         if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
 618                                 /* Check if chain for this logical */
 619                                 if (logical_block == first_logical_block) {
 620                                         if (last_block != BLOCK_NIL)
 621                                                 s->PUtable[last_block] = block;
 622                                 }
 623                                 break;
 624                         }
 625
 626                         /* Check for invalid block */
 627                         if (erase_mark != ERASE_MARK) {
 628                                 printk(KERN_WARNING "INFTL: corrupt block %d "
 629                                         "in chain %d, chain length %d, erase "
 630                                         "mark 0x%x?\n", block, first_block,
 631                                         chain_length, erase_mark);
 632                                 /*
 633                                  * Assume end of chain, probably incomplete
 634                                  * fold/erase...
 635                                  */
 636                                 if (chain_length == 0)
 637                                         do_format_chain++;
 638                                 break;
 639                         }
 640
 641                         /* Check for it being free already then... */
 642                         if ((logical_block == BLOCK_FREE) ||
 643                             (logical_block == BLOCK_NIL)) {
 644                                 s->PUtable[block] = BLOCK_FREE;
 645                                 break;
 646                         }
 647
 648                         /* Sanity checks on block numbers */
 649                         if ((logical_block >= s->nb_blocks) ||
 650                             ((prev_block >= s->nb_blocks) &&
 651                              (prev_block != BLOCK_NIL))) {
 652                                 if (chain_length > 0) {
 653                                         printk(KERN_WARNING "INFTL: corrupt "
 654                                                 "block %d in chain %d?\n",
 655                                                 block, first_block);
 656                                         do_format_chain++;
 657                                 }
 658                                 break;
 659                         }
 660
 661                         if (first_logical_block == BLOCK_NIL) {
 662                                 first_logical_block = logical_block;
 663                         } else {
 664                                 if (first_logical_block != logical_block) {
 665                                         /* Normal for folded chain... */
 666                                         break;
 667                                 }
 668                         }
 669
 670                         /*
 671                          * Current block is valid, so if we followed a virtual
 672                          * chain to get here then we can set the previous
 673                          * block pointer in our PUtable now. Then move onto
 674                          * the previous block in the chain.
 675                          */
 676                         s->PUtable[block] = BLOCK_NIL;
 677                         if (last_block != BLOCK_NIL)
 678                                 s->PUtable[last_block] = block;
 679                         last_block = block;
 680                         block = prev_block;
 681
 682                         /* Check for end of chain */
 683                         if (block == BLOCK_NIL)
 684                                 break;
 685
 686                         /* Validate next block before following it... */
 687                         if (block > s->lastEUN) {
 688                                 printk(KERN_WARNING "INFTL: invalid previous "
 689                                         "block %d in chain %d?\n", block,
 690                                         first_block);
 691                                 do_format_chain++;
 692                                 break;
 693                         }
 694                 }
 695
 696                 if (do_format_chain) {
 697                         format_chain(s, first_block);
 698                         continue;
 699                 }
 700
 701                 /*
 702                  * Looks like a valid chain then. It may not really be the
 703                  * newest block in the chain, but it is the newest we have
 704                  * found so far. We might update it in later iterations of
 705                  * this loop if we find something newer.
 706                  */
 707                 s->VUtable[first_logical_block] = first_block;
 708                 logical_block = BLOCK_NIL;
 709         }
 710
 711         INFTL_dumptables(s);
 712
 713         /*
 714          * Second pass, check for infinite loops in chains. These are
 715          * possible because we don't update the previous pointers when
 716          * we fold chains. No big deal, just fix them up in PUtable.
 717          */
 718         pr_debug("INFTL: pass 2, validate virtual chains\n");
 719         for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
 720                 block = s->VUtable[logical_block];
 721                 last_block = BLOCK_NIL;
 722
 723                 /* Check for free/reserved/nil */
 724                 if (block >= BLOCK_RESERVED)
 725                         continue;
 726
 727                 ANAC = ANACtable[block];
 728                 for (i = 0; i < s->numvunits; i++) {
 729                         if (s->PUtable[block] == BLOCK_NIL)
 730                                 break;
 731                         if (s->PUtable[block] > s->lastEUN) {
 732                                 printk(KERN_WARNING "INFTL: invalid prev %d, "
 733                                         "in virtual chain %d\n",
 734                                         s->PUtable[block], logical_block);
 735                                 s->PUtable[block] = BLOCK_NIL;
 736
 737                         }
 738                         if (ANACtable[block] != ANAC) {
 739                                 /*
 740                                  * Chain must point back to itself. This is ok,
 741                                  * but we will need adjust the tables with this
 742                                  * newest block and oldest block.
 743                                  */
 744                                 s->VUtable[logical_block] = block;
 745                                 s->PUtable[last_block] = BLOCK_NIL;
 746                                 break;
 747                         }
 748
 749                         ANAC--;
 750                         last_block = block;
 751                         block = s->PUtable[block];
 752                 }
 753
 754                 if (i >= s->nb_blocks) {
 755                         /*
 756                          * Uhoo, infinite chain with valid ANACS!
 757                          * Format whole chain...
 758                          */
 759                         format_chain(s, first_block);
 760                 }
 761         }
 762
 763         INFTL_dumptables(s);
 764         INFTL_dumpVUchains(s);
 765
 766         /*
 767          * Third pass, format unreferenced blocks and init free block count.
 768          */
 769         s->numfreeEUNs = 0;
 770         s->LastFreeEUN = BLOCK_NIL;
 771
 772         pr_debug("INFTL: pass 3, format unused blocks\n");
 773         for (block = s->firstEUN; block <= s->lastEUN; block++) {
 774                 if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
 775                         printk("INFTL: unreferenced block %d, formatting it\n",
 776                                 block);
 777                         if (INFTL_formatblock(s, block) < 0)
 778                                 s->PUtable[block] = BLOCK_RESERVED;
 779                         else
 780                                 s->PUtable[block] = BLOCK_FREE;
 781                 }
 782                 if (s->PUtable[block] == BLOCK_FREE) {
 783                         s->numfreeEUNs++;
 784                         if (s->LastFreeEUN == BLOCK_NIL)
 785                                 s->LastFreeEUN = block;
 786                 }
 787         }
 788
 789         kfree(ANACtable);
 790         return 0;
 791 }