1 /* 2 * NFTL mount code with extensive checks 3 * 4 * Author: Fabrice Bellard (fabrice.bellard@netgem.com) 5 * Copyright (C) 2000 Netgem S.A. 6 * 7 * $Id: nftlmount.c,v 1.40 2004/11/22 14:38:29 kalev Exp $ 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 24 #include <linux/kernel.h> 25 #include <asm/errno.h> 26 #include <linux/delay.h> 27 #include <linux/slab.h> 28 #include <linux/mtd/mtd.h> 29 #include <linux/mtd/nand.h> 30 #include <linux/mtd/nftl.h> 31 32 #define SECTORSIZE 512 33 34 char nftlmountrev[]="$Revision: 1.40 $"; 35 36 /* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the 37 * various device information of the NFTL partition and Bad Unit Table. Update 38 * the ReplUnitTable[] table accroding to the Bad Unit Table. ReplUnitTable[] 39 * is used for management of Erase Unit in other routines in nftl.c and nftlmount.c 40 */ 41 static int find_boot_record(struct NFTLrecord *nftl) 42 { 43 struct nftl_uci1 h1; 44 unsigned int block, boot_record_count = 0; 45 size_t retlen; 46 u8 buf[SECTORSIZE]; 47 struct NFTLMediaHeader *mh = &nftl->MediaHdr; 48 unsigned int i; 49 50 /* Assume logical EraseSize == physical erasesize for starting the scan. 51 We'll sort it out later if we find a MediaHeader which says otherwise */ 52 /* Actually, we won't. The new DiskOnChip driver has already scanned 53 the MediaHeader and adjusted the virtual erasesize it presents in 54 the mtd device accordingly. We could even get rid of 55 nftl->EraseSize if there were any point in doing so. */ 56 nftl->EraseSize = nftl->mbd.mtd->erasesize; 57 nftl->nb_blocks = nftl->mbd.mtd->size / nftl->EraseSize; 58 59 nftl->MediaUnit = BLOCK_NIL; 60 nftl->SpareMediaUnit = BLOCK_NIL; 61 62 /* search for a valid boot record */ 63 for (block = 0; block < nftl->nb_blocks; block++) { 64 int ret; 65 66 /* Check for ANAND header first. Then can whinge if it's found but later 67 checks fail */ 68 ret = MTD_READ(nftl->mbd.mtd, block * nftl->EraseSize, SECTORSIZE, &retlen, buf); 69 /* We ignore ret in case the ECC of the MediaHeader is invalid 70 (which is apparently acceptable) */ 71 if (retlen != SECTORSIZE) { 72 static int warncount = 5; 73 74 if (warncount) { 75 printk(KERN_WARNING "Block read at 0x%x of mtd%d failed: %d\n", 76 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 77 if (!--warncount) 78 printk(KERN_WARNING "Further failures for this block will not be printed\n"); 79 } 80 continue; 81 } 82 83 if (retlen < 6 || memcmp(buf, "ANAND", 6)) { 84 /* ANAND\0 not found. Continue */ 85 #if 0 86 printk(KERN_DEBUG "ANAND header not found at 0x%x in mtd%d\n", 87 block * nftl->EraseSize, nftl->mbd.mtd->index); 88 #endif 89 continue; 90 } 91 92 /* To be safer with BIOS, also use erase mark as discriminant */ 93 if ((ret = MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + SECTORSIZE + 8, 94 8, &retlen, (char *)&h1) < 0)) { 95 printk(KERN_WARNING "ANAND header found at 0x%x in mtd%d, but OOB data read failed (err %d)\n", 96 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 97 continue; 98 } 99 100 #if 0 /* Some people seem to have devices without ECC or erase marks 101 on the Media Header blocks. There are enough other sanity 102 checks in here that we can probably do without it. 103 */ 104 if (le16_to_cpu(h1.EraseMark | h1.EraseMark1) != ERASE_MARK) { 105 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but erase mark not present (0x%04x,0x%04x instead)\n", 106 block * nftl->EraseSize, nftl->mbd.mtd->index, 107 le16_to_cpu(h1.EraseMark), le16_to_cpu(h1.EraseMark1)); 108 continue; 109 } 110 111 /* Finally reread to check ECC */ 112 if ((ret = MTD_READECC(nftl->mbd.mtd, block * nftl->EraseSize, SECTORSIZE, 113 &retlen, buf, (char *)&oob, NULL) < 0)) { 114 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but ECC read failed (err %d)\n", 115 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 116 continue; 117 } 118 119 /* Paranoia. Check the ANAND header is still there after the ECC read */ 120 if (memcmp(buf, "ANAND", 6)) { 121 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but went away on reread!\n", 122 block * nftl->EraseSize, nftl->mbd.mtd->index); 123 printk(KERN_NOTICE "New data are: %02x %02x %02x %02x %02x %02x\n", 124 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]); 125 continue; 126 } 127 #endif 128 /* OK, we like it. */ 129 130 if (boot_record_count) { 131 /* We've already processed one. So we just check if 132 this one is the same as the first one we found */ 133 if (memcmp(mh, buf, sizeof(struct NFTLMediaHeader))) { 134 printk(KERN_NOTICE "NFTL Media Headers at 0x%x and 0x%x disagree.\n", 135 nftl->MediaUnit * nftl->EraseSize, block * nftl->EraseSize); 136 /* if (debug) Print both side by side */ 137 if (boot_record_count < 2) { 138 /* We haven't yet seen two real ones */ 139 return -1; 140 } 141 continue; 142 } 143 if (boot_record_count == 1) 144 nftl->SpareMediaUnit = block; 145 146 /* Mark this boot record (NFTL MediaHeader) block as reserved */ 147 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 148 149 150 boot_record_count++; 151 continue; 152 } 153 154 /* This is the first we've seen. Copy the media header structure into place */ 155 memcpy(mh, buf, sizeof(struct NFTLMediaHeader)); 156 157 /* Do some sanity checks on it */ 158 #if 0 159 The new DiskOnChip driver scans the MediaHeader itself, and presents a virtual 160 erasesize based on UnitSizeFactor. So the erasesize we read from the mtd 161 device is already correct. 162 if (mh->UnitSizeFactor == 0) { 163 printk(KERN_NOTICE "NFTL: UnitSizeFactor 0x00 detected. This violates the spec but we think we know what it means...\n"); 164 } else if (mh->UnitSizeFactor < 0xfc) { 165 printk(KERN_NOTICE "Sorry, we don't support UnitSizeFactor 0x%02x\n", 166 mh->UnitSizeFactor); 167 return -1; 168 } else if (mh->UnitSizeFactor != 0xff) { 169 printk(KERN_NOTICE "WARNING: Support for NFTL with UnitSizeFactor 0x%02x is experimental\n", 170 mh->UnitSizeFactor); 171 nftl->EraseSize = nftl->mbd.mtd->erasesize << (0xff - mh->UnitSizeFactor); 172 nftl->nb_blocks = nftl->mbd.mtd->size / nftl->EraseSize; 173 } 174 #endif 175 nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN); 176 if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) { 177 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n"); 178 printk(KERN_NOTICE "nb_boot_blocks (%d) + 2 > nb_blocks (%d)\n", 179 nftl->nb_boot_blocks, nftl->nb_blocks); 180 return -1; 181 } 182 183 nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize; 184 if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) { 185 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n"); 186 printk(KERN_NOTICE "numvunits (%d) > nb_blocks (%d) - nb_boot_blocks(%d) - 2\n", 187 nftl->numvunits, nftl->nb_blocks, nftl->nb_boot_blocks); 188 return -1; 189 } 190 191 nftl->mbd.size = nftl->numvunits * (nftl->EraseSize / SECTORSIZE); 192 193 /* If we're not using the last sectors in the device for some reason, 194 reduce nb_blocks accordingly so we forget they're there */ 195 nftl->nb_blocks = le16_to_cpu(mh->NumEraseUnits) + le16_to_cpu(mh->FirstPhysicalEUN); 196 197 /* XXX: will be suppressed */ 198 nftl->lastEUN = nftl->nb_blocks - 1; 199 200 /* memory alloc */ 201 nftl->EUNtable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL); 202 if (!nftl->EUNtable) { 203 printk(KERN_NOTICE "NFTL: allocation of EUNtable failed\n"); 204 return -ENOMEM; 205 } 206 207 nftl->ReplUnitTable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL); 208 if (!nftl->ReplUnitTable) { 209 kfree(nftl->EUNtable); 210 printk(KERN_NOTICE "NFTL: allocation of ReplUnitTable failed\n"); 211 return -ENOMEM; 212 } 213 214 /* mark the bios blocks (blocks before NFTL MediaHeader) as reserved */ 215 for (i = 0; i < nftl->nb_boot_blocks; i++) 216 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 217 /* mark all remaining blocks as potentially containing data */ 218 for (; i < nftl->nb_blocks; i++) { 219 nftl->ReplUnitTable[i] = BLOCK_NOTEXPLORED; 220 } 221 222 /* Mark this boot record (NFTL MediaHeader) block as reserved */ 223 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 224 225 /* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */ 226 for (i = 0; i < nftl->nb_blocks; i++) { 227 #if 0 228 The new DiskOnChip driver already scanned the bad block table. Just query it. 229 if ((i & (SECTORSIZE - 1)) == 0) { 230 /* read one sector for every SECTORSIZE of blocks */ 231 if ((ret = MTD_READECC(nftl->mbd.mtd, block * nftl->EraseSize + 232 i + SECTORSIZE, SECTORSIZE, &retlen, buf, 233 (char *)&oob, NULL)) < 0) { 234 printk(KERN_NOTICE "Read of bad sector table failed (err %d)\n", 235 ret); 236 kfree(nftl->ReplUnitTable); 237 kfree(nftl->EUNtable); 238 return -1; 239 } 240 } 241 /* mark the Bad Erase Unit as RESERVED in ReplUnitTable */ 242 if (buf[i & (SECTORSIZE - 1)] != 0xff) 243 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 244 #endif 245 if (nftl->mbd.mtd->block_isbad(nftl->mbd.mtd, i * nftl->EraseSize)) 246 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 247 } 248 249 nftl->MediaUnit = block; 250 boot_record_count++; 251 252 } /* foreach (block) */ 253 254 return boot_record_count?0:-1; 255 } 256 257 static int memcmpb(void *a, int c, int n) 258 { 259 int i; 260 for (i = 0; i < n; i++) { 261 if (c != ((unsigned char *)a)[i]) 262 return 1; 263 } 264 return 0; 265 } 266 267 /* check_free_sector: check if a free sector is actually FREE, i.e. All 0xff in data and oob area */ 268 static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int len, 269 int check_oob) 270 { 271 int i; 272 size_t retlen; 273 u8 buf[SECTORSIZE + nftl->mbd.mtd->oobsize]; 274 275 for (i = 0; i < len; i += SECTORSIZE) { 276 if (MTD_READECC(nftl->mbd.mtd, address, SECTORSIZE, &retlen, buf, &buf[SECTORSIZE], &nftl->oobinfo) < 0) 277 return -1; 278 if (memcmpb(buf, 0xff, SECTORSIZE) != 0) 279 return -1; 280 281 if (check_oob) { 282 if (memcmpb(buf + SECTORSIZE, 0xff, nftl->mbd.mtd->oobsize) != 0) 283 return -1; 284 } 285 address += SECTORSIZE; 286 } 287 288 return 0; 289 } 290 291 /* NFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase Unit and 292 * Update NFTL metadata. Each erase operation is checked with check_free_sectors 293 * 294 * Return: 0 when succeed, -1 on error. 295 * 296 * ToDo: 1. Is it neceressary to check_free_sector after erasing ?? 297 */ 298 int NFTL_formatblock(struct NFTLrecord *nftl, int block) 299 { 300 size_t retlen; 301 unsigned int nb_erases, erase_mark; 302 struct nftl_uci1 uci; 303 struct erase_info *instr = &nftl->instr; 304 305 /* Read the Unit Control Information #1 for Wear-Leveling */ 306 if (MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + SECTORSIZE + 8, 307 8, &retlen, (char *)&uci) < 0) 308 goto default_uci1; 309 310 erase_mark = le16_to_cpu ((uci.EraseMark | uci.EraseMark1)); 311 if (erase_mark != ERASE_MARK) { 312 default_uci1: 313 uci.EraseMark = cpu_to_le16(ERASE_MARK); 314 uci.EraseMark1 = cpu_to_le16(ERASE_MARK); 315 uci.WearInfo = cpu_to_le32(0); 316 } 317 318 memset(instr, 0, sizeof(struct erase_info)); 319 320 /* XXX: use async erase interface, XXX: test return code */ 321 instr->mtd = nftl->mbd.mtd; 322 instr->addr = block * nftl->EraseSize; 323 instr->len = nftl->EraseSize; 324 MTD_ERASE(nftl->mbd.mtd, instr); 325 326 if (instr->state == MTD_ERASE_FAILED) { 327 printk("Error while formatting block %d\n", block); 328 goto fail; 329 } 330 331 /* increase and write Wear-Leveling info */ 332 nb_erases = le32_to_cpu(uci.WearInfo); 333 nb_erases++; 334 335 /* wrap (almost impossible with current flashs) or free block */ 336 if (nb_erases == 0) 337 nb_erases = 1; 338 339 /* check the "freeness" of Erase Unit before updating metadata 340 * FixMe: is this check really necessary ? since we have check the 341 * return code after the erase operation. */ 342 if (check_free_sectors(nftl, instr->addr, nftl->EraseSize, 1) != 0) 343 goto fail; 344 345 uci.WearInfo = le32_to_cpu(nb_erases); 346 if (MTD_WRITEOOB(nftl->mbd.mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, 347 &retlen, (char *)&uci) < 0) 348 goto fail; 349 return 0; 350 fail: 351 /* could not format, update the bad block table (caller is responsible 352 for setting the ReplUnitTable to BLOCK_RESERVED on failure) */ 353 nftl->mbd.mtd->block_markbad(nftl->mbd.mtd, instr->addr); 354 return -1; 355 } 356 357 /* check_sectors_in_chain: Check that each sector of a Virtual Unit Chain is correct. 358 * Mark as 'IGNORE' each incorrect sector. This check is only done if the chain 359 * was being folded when NFTL was interrupted. 360 * 361 * The check_free_sectors in this function is neceressary. There is a possible 362 * situation that after writing the Data area, the Block Control Information is 363 * not updated according (due to power failure or something) which leaves the block 364 * in an umconsistent state. So we have to check if a block is really FREE in this 365 * case. */ 366 static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_block) 367 { 368 unsigned int block, i, status; 369 struct nftl_bci bci; 370 int sectors_per_block; 371 size_t retlen; 372 373 sectors_per_block = nftl->EraseSize / SECTORSIZE; 374 block = first_block; 375 for (;;) { 376 for (i = 0; i < sectors_per_block; i++) { 377 if (MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + i * SECTORSIZE, 378 8, &retlen, (char *)&bci) < 0) 379 status = SECTOR_IGNORE; 380 else 381 status = bci.Status | bci.Status1; 382 383 switch(status) { 384 case SECTOR_FREE: 385 /* verify that the sector is really free. If not, mark 386 as ignore */ 387 if (memcmpb(&bci, 0xff, 8) != 0 || 388 check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE, 389 SECTORSIZE, 0) != 0) { 390 printk("Incorrect free sector %d in block %d: " 391 "marking it as ignored\n", 392 i, block); 393 394 /* sector not free actually : mark it as SECTOR_IGNORE */ 395 bci.Status = SECTOR_IGNORE; 396 bci.Status1 = SECTOR_IGNORE; 397 MTD_WRITEOOB(nftl->mbd.mtd, 398 block * nftl->EraseSize + i * SECTORSIZE, 399 8, &retlen, (char *)&bci); 400 } 401 break; 402 default: 403 break; 404 } 405 } 406 407 /* proceed to next Erase Unit on the chain */ 408 block = nftl->ReplUnitTable[block]; 409 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 410 printk("incorrect ReplUnitTable[] : %d\n", block); 411 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 412 break; 413 } 414 } 415 416 /* calc_chain_lenght: Walk through a Virtual Unit Chain and estimate chain length */ 417 static int calc_chain_length(struct NFTLrecord *nftl, unsigned int first_block) 418 { 419 unsigned int length = 0, block = first_block; 420 421 for (;;) { 422 length++; 423 /* avoid infinite loops, although this is guaranted not to 424 happen because of the previous checks */ 425 if (length >= nftl->nb_blocks) { 426 printk("nftl: length too long %d !\n", length); 427 break; 428 } 429 430 block = nftl->ReplUnitTable[block]; 431 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 432 printk("incorrect ReplUnitTable[] : %d\n", block); 433 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 434 break; 435 } 436 return length; 437 } 438 439 /* format_chain: Format an invalid Virtual Unit chain. It frees all the Erase Units in a 440 * Virtual Unit Chain, i.e. all the units are disconnected. 441 * 442 * It is not stricly correct to begin from the first block of the chain because 443 * if we stop the code, we may see again a valid chain if there was a first_block 444 * flag in a block inside it. But is it really a problem ? 445 * 446 * FixMe: Figure out what the last statesment means. What if power failure when we are 447 * in the for (;;) loop formatting blocks ?? 448 */ 449 static void format_chain(struct NFTLrecord *nftl, unsigned int first_block) 450 { 451 unsigned int block = first_block, block1; 452 453 printk("Formatting chain at block %d\n", first_block); 454 455 for (;;) { 456 block1 = nftl->ReplUnitTable[block]; 457 458 printk("Formatting block %d\n", block); 459 if (NFTL_formatblock(nftl, block) < 0) { 460 /* cannot format !!!! Mark it as Bad Unit */ 461 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 462 } else { 463 nftl->ReplUnitTable[block] = BLOCK_FREE; 464 } 465 466 /* goto next block on the chain */ 467 block = block1; 468 469 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 470 printk("incorrect ReplUnitTable[] : %d\n", block); 471 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 472 break; 473 } 474 } 475 476 /* check_and_mark_free_block: Verify that a block is free in the NFTL sense (valid erase mark) or 477 * totally free (only 0xff). 478 * 479 * Definition: Free Erase Unit -- A properly erased/formatted Free Erase Unit should have meet the 480 * following critia: 481 * 1. */ 482 static int check_and_mark_free_block(struct NFTLrecord *nftl, int block) 483 { 484 struct nftl_uci1 h1; 485 unsigned int erase_mark; 486 size_t retlen; 487 488 /* check erase mark. */ 489 if (MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, 490 &retlen, (char *)&h1) < 0) 491 return -1; 492 493 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); 494 if (erase_mark != ERASE_MARK) { 495 /* if no erase mark, the block must be totally free. This is 496 possible in two cases : empty filsystem or interrupted erase (very unlikely) */ 497 if (check_free_sectors (nftl, block * nftl->EraseSize, nftl->EraseSize, 1) != 0) 498 return -1; 499 500 /* free block : write erase mark */ 501 h1.EraseMark = cpu_to_le16(ERASE_MARK); 502 h1.EraseMark1 = cpu_to_le16(ERASE_MARK); 503 h1.WearInfo = cpu_to_le32(0); 504 if (MTD_WRITEOOB(nftl->mbd.mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, 505 &retlen, (char *)&h1) < 0) 506 return -1; 507 } else { 508 #if 0 509 /* if erase mark present, need to skip it when doing check */ 510 for (i = 0; i < nftl->EraseSize; i += SECTORSIZE) { 511 /* check free sector */ 512 if (check_free_sectors (nftl, block * nftl->EraseSize + i, 513 SECTORSIZE, 0) != 0) 514 return -1; 515 516 if (MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + i, 517 16, &retlen, buf) < 0) 518 return -1; 519 if (i == SECTORSIZE) { 520 /* skip erase mark */ 521 if (memcmpb(buf, 0xff, 8)) 522 return -1; 523 } else { 524 if (memcmpb(buf, 0xff, 16)) 525 return -1; 526 } 527 } 528 #endif 529 } 530 531 return 0; 532 } 533 534 /* get_fold_mark: Read fold mark from Unit Control Information #2, we use FOLD_MARK_IN_PROGRESS 535 * to indicate that we are in the progression of a Virtual Unit Chain folding. If the UCI #2 536 * is FOLD_MARK_IN_PROGRESS when mounting the NFTL, the (previous) folding process is interrupted 537 * for some reason. A clean up/check of the VUC is neceressary in this case. 538 * 539 * WARNING: return 0 if read error 540 */ 541 static int get_fold_mark(struct NFTLrecord *nftl, unsigned int block) 542 { 543 struct nftl_uci2 uci; 544 size_t retlen; 545 546 if (MTD_READOOB(nftl->mbd.mtd, block * nftl->EraseSize + 2 * SECTORSIZE + 8, 547 8, &retlen, (char *)&uci) < 0) 548 return 0; 549 550 return le16_to_cpu((uci.FoldMark | uci.FoldMark1)); 551 } 552 553 int NFTL_mount(struct NFTLrecord *s) 554 { 555 int i; 556 unsigned int first_logical_block, logical_block, rep_block, nb_erases, erase_mark; 557 unsigned int block, first_block, is_first_block; 558 int chain_length, do_format_chain; 559 struct nftl_uci0 h0; 560 struct nftl_uci1 h1; 561 size_t retlen; 562 563 /* search for NFTL MediaHeader and Spare NFTL Media Header */ 564 if (find_boot_record(s) < 0) { 565 printk("Could not find valid boot record\n"); 566 return -1; 567 } 568 569 /* init the logical to physical table */ 570 for (i = 0; i < s->nb_blocks; i++) { 571 s->EUNtable[i] = BLOCK_NIL; 572 } 573 574 /* first pass : explore each block chain */ 575 first_logical_block = 0; 576 for (first_block = 0; first_block < s->nb_blocks; first_block++) { 577 /* if the block was not already explored, we can look at it */ 578 if (s->ReplUnitTable[first_block] == BLOCK_NOTEXPLORED) { 579 block = first_block; 580 chain_length = 0; 581 do_format_chain = 0; 582 583 for (;;) { 584 /* read the block header. If error, we format the chain */ 585 if (MTD_READOOB(s->mbd.mtd, block * s->EraseSize + 8, 8, 586 &retlen, (char *)&h0) < 0 || 587 MTD_READOOB(s->mbd.mtd, block * s->EraseSize + SECTORSIZE + 8, 8, 588 &retlen, (char *)&h1) < 0) { 589 s->ReplUnitTable[block] = BLOCK_NIL; 590 do_format_chain = 1; 591 break; 592 } 593 594 logical_block = le16_to_cpu ((h0.VirtUnitNum | h0.SpareVirtUnitNum)); 595 rep_block = le16_to_cpu ((h0.ReplUnitNum | h0.SpareReplUnitNum)); 596 nb_erases = le32_to_cpu (h1.WearInfo); 597 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); 598 599 is_first_block = !(logical_block >> 15); 600 logical_block = logical_block & 0x7fff; 601 602 /* invalid/free block test */ 603 if (erase_mark != ERASE_MARK || logical_block >= s->nb_blocks) { 604 if (chain_length == 0) { 605 /* if not currently in a chain, we can handle it safely */ 606 if (check_and_mark_free_block(s, block) < 0) { 607 /* not really free: format it */ 608 printk("Formatting block %d\n", block); 609 if (NFTL_formatblock(s, block) < 0) { 610 /* could not format: reserve the block */ 611 s->ReplUnitTable[block] = BLOCK_RESERVED; 612 } else { 613 s->ReplUnitTable[block] = BLOCK_FREE; 614 } 615 } else { 616 /* free block: mark it */ 617 s->ReplUnitTable[block] = BLOCK_FREE; 618 } 619 /* directly examine the next block. */ 620 goto examine_ReplUnitTable; 621 } else { 622 /* the block was in a chain : this is bad. We 623 must format all the chain */ 624 printk("Block %d: free but referenced in chain %d\n", 625 block, first_block); 626 s->ReplUnitTable[block] = BLOCK_NIL; 627 do_format_chain = 1; 628 break; 629 } 630 } 631 632 /* we accept only first blocks here */ 633 if (chain_length == 0) { 634 /* this block is not the first block in chain : 635 ignore it, it will be included in a chain 636 later, or marked as not explored */ 637 if (!is_first_block) 638 goto examine_ReplUnitTable; 639 first_logical_block = logical_block; 640 } else { 641 if (logical_block != first_logical_block) { 642 printk("Block %d: incorrect logical block: %d expected: %d\n", 643 block, logical_block, first_logical_block); 644 /* the chain is incorrect : we must format it, 645 but we need to read it completly */ 646 do_format_chain = 1; 647 } 648 if (is_first_block) { 649 /* we accept that a block is marked as first 650 block while being last block in a chain 651 only if the chain is being folded */ 652 if (get_fold_mark(s, block) != FOLD_MARK_IN_PROGRESS || 653 rep_block != 0xffff) { 654 printk("Block %d: incorrectly marked as first block in chain\n", 655 block); 656 /* the chain is incorrect : we must format it, 657 but we need to read it completly */ 658 do_format_chain = 1; 659 } else { 660 printk("Block %d: folding in progress - ignoring first block flag\n", 661 block); 662 } 663 } 664 } 665 chain_length++; 666 if (rep_block == 0xffff) { 667 /* no more blocks after */ 668 s->ReplUnitTable[block] = BLOCK_NIL; 669 break; 670 } else if (rep_block >= s->nb_blocks) { 671 printk("Block %d: referencing invalid block %d\n", 672 block, rep_block); 673 do_format_chain = 1; 674 s->ReplUnitTable[block] = BLOCK_NIL; 675 break; 676 } else if (s->ReplUnitTable[rep_block] != BLOCK_NOTEXPLORED) { 677 /* same problem as previous 'is_first_block' test: 678 we accept that the last block of a chain has 679 the first_block flag set if folding is in 680 progress. We handle here the case where the 681 last block appeared first */ 682 if (s->ReplUnitTable[rep_block] == BLOCK_NIL && 683 s->EUNtable[first_logical_block] == rep_block && 684 get_fold_mark(s, first_block) == FOLD_MARK_IN_PROGRESS) { 685 /* EUNtable[] will be set after */ 686 printk("Block %d: folding in progress - ignoring first block flag\n", 687 rep_block); 688 s->ReplUnitTable[block] = rep_block; 689 s->EUNtable[first_logical_block] = BLOCK_NIL; 690 } else { 691 printk("Block %d: referencing block %d already in another chain\n", 692 block, rep_block); 693 /* XXX: should handle correctly fold in progress chains */ 694 do_format_chain = 1; 695 s->ReplUnitTable[block] = BLOCK_NIL; 696 } 697 break; 698 } else { 699 /* this is OK */ 700 s->ReplUnitTable[block] = rep_block; 701 block = rep_block; 702 } 703 } 704 705 /* the chain was completely explored. Now we can decide 706 what to do with it */ 707 if (do_format_chain) { 708 /* invalid chain : format it */ 709 format_chain(s, first_block); 710 } else { 711 unsigned int first_block1, chain_to_format, chain_length1; 712 int fold_mark; 713 714 /* valid chain : get foldmark */ 715 fold_mark = get_fold_mark(s, first_block); 716 if (fold_mark == 0) { 717 /* cannot get foldmark : format the chain */ 718 printk("Could read foldmark at block %d\n", first_block); 719 format_chain(s, first_block); 720 } else { 721 if (fold_mark == FOLD_MARK_IN_PROGRESS) 722 check_sectors_in_chain(s, first_block); 723 724 /* now handle the case where we find two chains at the 725 same virtual address : we select the longer one, 726 because the shorter one is the one which was being 727 folded if the folding was not done in place */ 728 first_block1 = s->EUNtable[first_logical_block]; 729 if (first_block1 != BLOCK_NIL) { 730 /* XXX: what to do if same length ? */ 731 chain_length1 = calc_chain_length(s, first_block1); 732 printk("Two chains at blocks %d (len=%d) and %d (len=%d)\n", 733 first_block1, chain_length1, first_block, chain_length); 734 735 if (chain_length >= chain_length1) { 736 chain_to_format = first_block1; 737 s->EUNtable[first_logical_block] = first_block; 738 } else { 739 chain_to_format = first_block; 740 } 741 format_chain(s, chain_to_format); 742 } else { 743 s->EUNtable[first_logical_block] = first_block; 744 } 745 } 746 } 747 } 748 examine_ReplUnitTable:; 749 } 750 751 /* second pass to format unreferenced blocks and init free block count */ 752 s->numfreeEUNs = 0; 753 s->LastFreeEUN = le16_to_cpu(s->MediaHdr.FirstPhysicalEUN); 754 755 for (block = 0; block < s->nb_blocks; block++) { 756 if (s->ReplUnitTable[block] == BLOCK_NOTEXPLORED) { 757 printk("Unreferenced block %d, formatting it\n", block); 758 if (NFTL_formatblock(s, block) < 0) 759 s->ReplUnitTable[block] = BLOCK_RESERVED; 760 else 761 s->ReplUnitTable[block] = BLOCK_FREE; 762 } 763 if (s->ReplUnitTable[block] == BLOCK_FREE) { 764 s->numfreeEUNs++; 765 s->LastFreeEUN = block; 766 } 767 } 768 769 return 0; 770 } 771