1 /* 2 * NFTL mount code with extensive checks 3 * 4 * Author: Fabrice Bellard (fabrice.bellard@netgem.com) 5 * Copyright © 2000 Netgem S.A. 6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 23 #include <linux/kernel.h> 24 #include <asm/errno.h> 25 #include <linux/delay.h> 26 #include <linux/slab.h> 27 #include <linux/mtd/mtd.h> 28 #include <linux/mtd/rawnand.h> 29 #include <linux/mtd/nftl.h> 30 31 #define SECTORSIZE 512 32 33 /* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the 34 * various device information of the NFTL partition and Bad Unit Table. Update 35 * the ReplUnitTable[] table according to the Bad Unit Table. ReplUnitTable[] 36 * is used for management of Erase Unit in other routines in nftl.c and nftlmount.c 37 */ 38 static int find_boot_record(struct NFTLrecord *nftl) 39 { 40 struct nftl_uci1 h1; 41 unsigned int block, boot_record_count = 0; 42 size_t retlen; 43 u8 buf[SECTORSIZE]; 44 struct NFTLMediaHeader *mh = &nftl->MediaHdr; 45 struct mtd_info *mtd = nftl->mbd.mtd; 46 unsigned int i; 47 48 /* Assume logical EraseSize == physical erasesize for starting the scan. 49 We'll sort it out later if we find a MediaHeader which says otherwise */ 50 /* Actually, we won't. The new DiskOnChip driver has already scanned 51 the MediaHeader and adjusted the virtual erasesize it presents in 52 the mtd device accordingly. We could even get rid of 53 nftl->EraseSize if there were any point in doing so. */ 54 nftl->EraseSize = nftl->mbd.mtd->erasesize; 55 nftl->nb_blocks = (u32)nftl->mbd.mtd->size / nftl->EraseSize; 56 57 nftl->MediaUnit = BLOCK_NIL; 58 nftl->SpareMediaUnit = BLOCK_NIL; 59 60 /* search for a valid boot record */ 61 for (block = 0; block < nftl->nb_blocks; block++) { 62 int ret; 63 64 /* Check for ANAND header first. Then can whinge if it's found but later 65 checks fail */ 66 ret = mtd_read(mtd, block * nftl->EraseSize, SECTORSIZE, 67 &retlen, buf); 68 /* We ignore ret in case the ECC of the MediaHeader is invalid 69 (which is apparently acceptable) */ 70 if (retlen != SECTORSIZE) { 71 static int warncount = 5; 72 73 if (warncount) { 74 printk(KERN_WARNING "Block read at 0x%x of mtd%d failed: %d\n", 75 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 76 if (!--warncount) 77 printk(KERN_WARNING "Further failures for this block will not be printed\n"); 78 } 79 continue; 80 } 81 82 if (retlen < 6 || memcmp(buf, "ANAND", 6)) { 83 /* ANAND\0 not found. Continue */ 84 #if 0 85 printk(KERN_DEBUG "ANAND header not found at 0x%x in mtd%d\n", 86 block * nftl->EraseSize, nftl->mbd.mtd->index); 87 #endif 88 continue; 89 } 90 91 /* To be safer with BIOS, also use erase mark as discriminant */ 92 ret = nftl_read_oob(mtd, block * nftl->EraseSize + 93 SECTORSIZE + 8, 8, &retlen, 94 (char *)&h1); 95 if (ret < 0) { 96 printk(KERN_WARNING "ANAND header found at 0x%x in mtd%d, but OOB data read failed (err %d)\n", 97 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 98 continue; 99 } 100 101 #if 0 /* Some people seem to have devices without ECC or erase marks 102 on the Media Header blocks. There are enough other sanity 103 checks in here that we can probably do without it. 104 */ 105 if (le16_to_cpu(h1.EraseMark | h1.EraseMark1) != ERASE_MARK) { 106 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but erase mark not present (0x%04x,0x%04x instead)\n", 107 block * nftl->EraseSize, nftl->mbd.mtd->index, 108 le16_to_cpu(h1.EraseMark), le16_to_cpu(h1.EraseMark1)); 109 continue; 110 } 111 112 /* Finally reread to check ECC */ 113 ret = mtd->read(mtd, block * nftl->EraseSize, SECTORSIZE, 114 &retlen, buf); 115 if (ret < 0) { 116 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but ECC read failed (err %d)\n", 117 block * nftl->EraseSize, nftl->mbd.mtd->index, ret); 118 continue; 119 } 120 121 /* Paranoia. Check the ANAND header is still there after the ECC read */ 122 if (memcmp(buf, "ANAND", 6)) { 123 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but went away on reread!\n", 124 block * nftl->EraseSize, nftl->mbd.mtd->index); 125 printk(KERN_NOTICE "New data are: %02x %02x %02x %02x %02x %02x\n", 126 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]); 127 continue; 128 } 129 #endif 130 /* OK, we like it. */ 131 132 if (boot_record_count) { 133 /* We've already processed one. So we just check if 134 this one is the same as the first one we found */ 135 if (memcmp(mh, buf, sizeof(struct NFTLMediaHeader))) { 136 printk(KERN_NOTICE "NFTL Media Headers at 0x%x and 0x%x disagree.\n", 137 nftl->MediaUnit * nftl->EraseSize, block * nftl->EraseSize); 138 /* if (debug) Print both side by side */ 139 if (boot_record_count < 2) { 140 /* We haven't yet seen two real ones */ 141 return -1; 142 } 143 continue; 144 } 145 if (boot_record_count == 1) 146 nftl->SpareMediaUnit = block; 147 148 /* Mark this boot record (NFTL MediaHeader) block as reserved */ 149 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 150 151 152 boot_record_count++; 153 continue; 154 } 155 156 /* This is the first we've seen. Copy the media header structure into place */ 157 memcpy(mh, buf, sizeof(struct NFTLMediaHeader)); 158 159 /* Do some sanity checks on it */ 160 #if 0 161 The new DiskOnChip driver scans the MediaHeader itself, and presents a virtual 162 erasesize based on UnitSizeFactor. So the erasesize we read from the mtd 163 device is already correct. 164 if (mh->UnitSizeFactor == 0) { 165 printk(KERN_NOTICE "NFTL: UnitSizeFactor 0x00 detected. This violates the spec but we think we know what it means...\n"); 166 } else if (mh->UnitSizeFactor < 0xfc) { 167 printk(KERN_NOTICE "Sorry, we don't support UnitSizeFactor 0x%02x\n", 168 mh->UnitSizeFactor); 169 return -1; 170 } else if (mh->UnitSizeFactor != 0xff) { 171 printk(KERN_NOTICE "WARNING: Support for NFTL with UnitSizeFactor 0x%02x is experimental\n", 172 mh->UnitSizeFactor); 173 nftl->EraseSize = nftl->mbd.mtd->erasesize << (0xff - mh->UnitSizeFactor); 174 nftl->nb_blocks = (u32)nftl->mbd.mtd->size / nftl->EraseSize; 175 } 176 #endif 177 nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN); 178 if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) { 179 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n"); 180 printk(KERN_NOTICE "nb_boot_blocks (%d) + 2 > nb_blocks (%d)\n", 181 nftl->nb_boot_blocks, nftl->nb_blocks); 182 return -1; 183 } 184 185 nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize; 186 if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) { 187 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n"); 188 printk(KERN_NOTICE "numvunits (%d) > nb_blocks (%d) - nb_boot_blocks(%d) - 2\n", 189 nftl->numvunits, nftl->nb_blocks, nftl->nb_boot_blocks); 190 return -1; 191 } 192 193 nftl->mbd.size = nftl->numvunits * (nftl->EraseSize / SECTORSIZE); 194 195 /* If we're not using the last sectors in the device for some reason, 196 reduce nb_blocks accordingly so we forget they're there */ 197 nftl->nb_blocks = le16_to_cpu(mh->NumEraseUnits) + le16_to_cpu(mh->FirstPhysicalEUN); 198 199 /* XXX: will be suppressed */ 200 nftl->lastEUN = nftl->nb_blocks - 1; 201 202 /* memory alloc */ 203 nftl->EUNtable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL); 204 if (!nftl->EUNtable) { 205 printk(KERN_NOTICE "NFTL: allocation of EUNtable failed\n"); 206 return -ENOMEM; 207 } 208 209 nftl->ReplUnitTable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL); 210 if (!nftl->ReplUnitTable) { 211 kfree(nftl->EUNtable); 212 printk(KERN_NOTICE "NFTL: allocation of ReplUnitTable failed\n"); 213 return -ENOMEM; 214 } 215 216 /* mark the bios blocks (blocks before NFTL MediaHeader) as reserved */ 217 for (i = 0; i < nftl->nb_boot_blocks; i++) 218 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 219 /* mark all remaining blocks as potentially containing data */ 220 for (; i < nftl->nb_blocks; i++) { 221 nftl->ReplUnitTable[i] = BLOCK_NOTEXPLORED; 222 } 223 224 /* Mark this boot record (NFTL MediaHeader) block as reserved */ 225 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 226 227 /* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */ 228 for (i = 0; i < nftl->nb_blocks; i++) { 229 #if 0 230 The new DiskOnChip driver already scanned the bad block table. Just query it. 231 if ((i & (SECTORSIZE - 1)) == 0) { 232 /* read one sector for every SECTORSIZE of blocks */ 233 ret = mtd->read(nftl->mbd.mtd, 234 block * nftl->EraseSize + i + 235 SECTORSIZE, SECTORSIZE, 236 &retlen, buf); 237 if (ret < 0) { 238 printk(KERN_NOTICE "Read of bad sector table failed (err %d)\n", 239 ret); 240 kfree(nftl->ReplUnitTable); 241 kfree(nftl->EUNtable); 242 return -1; 243 } 244 } 245 /* mark the Bad Erase Unit as RESERVED in ReplUnitTable */ 246 if (buf[i & (SECTORSIZE - 1)] != 0xff) 247 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 248 #endif 249 if (mtd_block_isbad(nftl->mbd.mtd, 250 i * nftl->EraseSize)) 251 nftl->ReplUnitTable[i] = BLOCK_RESERVED; 252 } 253 254 nftl->MediaUnit = block; 255 boot_record_count++; 256 257 } /* foreach (block) */ 258 259 return boot_record_count?0:-1; 260 } 261 262 static int memcmpb(void *a, int c, int n) 263 { 264 int i; 265 for (i = 0; i < n; i++) { 266 if (c != ((unsigned char *)a)[i]) 267 return 1; 268 } 269 return 0; 270 } 271 272 /* check_free_sector: check if a free sector is actually FREE, i.e. All 0xff in data and oob area */ 273 static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int len, 274 int check_oob) 275 { 276 u8 buf[SECTORSIZE + nftl->mbd.mtd->oobsize]; 277 struct mtd_info *mtd = nftl->mbd.mtd; 278 size_t retlen; 279 int i; 280 281 for (i = 0; i < len; i += SECTORSIZE) { 282 if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf)) 283 return -1; 284 if (memcmpb(buf, 0xff, SECTORSIZE) != 0) 285 return -1; 286 287 if (check_oob) { 288 if(nftl_read_oob(mtd, address, mtd->oobsize, 289 &retlen, &buf[SECTORSIZE]) < 0) 290 return -1; 291 if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0) 292 return -1; 293 } 294 address += SECTORSIZE; 295 } 296 297 return 0; 298 } 299 300 /* NFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase Unit and 301 * Update NFTL metadata. Each erase operation is checked with check_free_sectors 302 * 303 * Return: 0 when succeed, -1 on error. 304 * 305 * ToDo: 1. Is it necessary to check_free_sector after erasing ?? 306 */ 307 int NFTL_formatblock(struct NFTLrecord *nftl, int block) 308 { 309 size_t retlen; 310 unsigned int nb_erases, erase_mark; 311 struct nftl_uci1 uci; 312 struct erase_info *instr = &nftl->instr; 313 struct mtd_info *mtd = nftl->mbd.mtd; 314 315 /* Read the Unit Control Information #1 for Wear-Leveling */ 316 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8, 317 8, &retlen, (char *)&uci) < 0) 318 goto default_uci1; 319 320 erase_mark = le16_to_cpu ((uci.EraseMark | uci.EraseMark1)); 321 if (erase_mark != ERASE_MARK) { 322 default_uci1: 323 uci.EraseMark = cpu_to_le16(ERASE_MARK); 324 uci.EraseMark1 = cpu_to_le16(ERASE_MARK); 325 uci.WearInfo = cpu_to_le32(0); 326 } 327 328 memset(instr, 0, sizeof(struct erase_info)); 329 330 /* XXX: use async erase interface, XXX: test return code */ 331 instr->mtd = nftl->mbd.mtd; 332 instr->addr = block * nftl->EraseSize; 333 instr->len = nftl->EraseSize; 334 mtd_erase(mtd, instr); 335 336 if (instr->state == MTD_ERASE_FAILED) { 337 printk("Error while formatting block %d\n", block); 338 goto fail; 339 } 340 341 /* increase and write Wear-Leveling info */ 342 nb_erases = le32_to_cpu(uci.WearInfo); 343 nb_erases++; 344 345 /* wrap (almost impossible with current flash) or free block */ 346 if (nb_erases == 0) 347 nb_erases = 1; 348 349 /* check the "freeness" of Erase Unit before updating metadata 350 * FixMe: is this check really necessary ? since we have check the 351 * return code after the erase operation. */ 352 if (check_free_sectors(nftl, instr->addr, nftl->EraseSize, 1) != 0) 353 goto fail; 354 355 uci.WearInfo = le32_to_cpu(nb_erases); 356 if (nftl_write_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 357 8, 8, &retlen, (char *)&uci) < 0) 358 goto fail; 359 return 0; 360 fail: 361 /* could not format, update the bad block table (caller is responsible 362 for setting the ReplUnitTable to BLOCK_RESERVED on failure) */ 363 mtd_block_markbad(nftl->mbd.mtd, instr->addr); 364 return -1; 365 } 366 367 /* check_sectors_in_chain: Check that each sector of a Virtual Unit Chain is correct. 368 * Mark as 'IGNORE' each incorrect sector. This check is only done if the chain 369 * was being folded when NFTL was interrupted. 370 * 371 * The check_free_sectors in this function is necessary. There is a possible 372 * situation that after writing the Data area, the Block Control Information is 373 * not updated according (due to power failure or something) which leaves the block 374 * in an inconsistent state. So we have to check if a block is really FREE in this 375 * case. */ 376 static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_block) 377 { 378 struct mtd_info *mtd = nftl->mbd.mtd; 379 unsigned int block, i, status; 380 struct nftl_bci bci; 381 int sectors_per_block; 382 size_t retlen; 383 384 sectors_per_block = nftl->EraseSize / SECTORSIZE; 385 block = first_block; 386 for (;;) { 387 for (i = 0; i < sectors_per_block; i++) { 388 if (nftl_read_oob(mtd, 389 block * nftl->EraseSize + i * SECTORSIZE, 390 8, &retlen, (char *)&bci) < 0) 391 status = SECTOR_IGNORE; 392 else 393 status = bci.Status | bci.Status1; 394 395 switch(status) { 396 case SECTOR_FREE: 397 /* verify that the sector is really free. If not, mark 398 as ignore */ 399 if (memcmpb(&bci, 0xff, 8) != 0 || 400 check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE, 401 SECTORSIZE, 0) != 0) { 402 printk("Incorrect free sector %d in block %d: " 403 "marking it as ignored\n", 404 i, block); 405 406 /* sector not free actually : mark it as SECTOR_IGNORE */ 407 bci.Status = SECTOR_IGNORE; 408 bci.Status1 = SECTOR_IGNORE; 409 nftl_write_oob(mtd, block * 410 nftl->EraseSize + 411 i * SECTORSIZE, 8, 412 &retlen, (char *)&bci); 413 } 414 break; 415 default: 416 break; 417 } 418 } 419 420 /* proceed to next Erase Unit on the chain */ 421 block = nftl->ReplUnitTable[block]; 422 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 423 printk("incorrect ReplUnitTable[] : %d\n", block); 424 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 425 break; 426 } 427 } 428 429 /* calc_chain_length: Walk through a Virtual Unit Chain and estimate chain length */ 430 static int calc_chain_length(struct NFTLrecord *nftl, unsigned int first_block) 431 { 432 unsigned int length = 0, block = first_block; 433 434 for (;;) { 435 length++; 436 /* avoid infinite loops, although this is guaranteed not to 437 happen because of the previous checks */ 438 if (length >= nftl->nb_blocks) { 439 printk("nftl: length too long %d !\n", length); 440 break; 441 } 442 443 block = nftl->ReplUnitTable[block]; 444 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 445 printk("incorrect ReplUnitTable[] : %d\n", block); 446 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 447 break; 448 } 449 return length; 450 } 451 452 /* format_chain: Format an invalid Virtual Unit chain. It frees all the Erase Units in a 453 * Virtual Unit Chain, i.e. all the units are disconnected. 454 * 455 * It is not strictly correct to begin from the first block of the chain because 456 * if we stop the code, we may see again a valid chain if there was a first_block 457 * flag in a block inside it. But is it really a problem ? 458 * 459 * FixMe: Figure out what the last statement means. What if power failure when we are 460 * in the for (;;) loop formatting blocks ?? 461 */ 462 static void format_chain(struct NFTLrecord *nftl, unsigned int first_block) 463 { 464 unsigned int block = first_block, block1; 465 466 printk("Formatting chain at block %d\n", first_block); 467 468 for (;;) { 469 block1 = nftl->ReplUnitTable[block]; 470 471 printk("Formatting block %d\n", block); 472 if (NFTL_formatblock(nftl, block) < 0) { 473 /* cannot format !!!! Mark it as Bad Unit */ 474 nftl->ReplUnitTable[block] = BLOCK_RESERVED; 475 } else { 476 nftl->ReplUnitTable[block] = BLOCK_FREE; 477 } 478 479 /* goto next block on the chain */ 480 block = block1; 481 482 if (!(block == BLOCK_NIL || block < nftl->nb_blocks)) 483 printk("incorrect ReplUnitTable[] : %d\n", block); 484 if (block == BLOCK_NIL || block >= nftl->nb_blocks) 485 break; 486 } 487 } 488 489 /* check_and_mark_free_block: Verify that a block is free in the NFTL sense (valid erase mark) or 490 * totally free (only 0xff). 491 * 492 * Definition: Free Erase Unit -- A properly erased/formatted Free Erase Unit should have meet the 493 * following criteria: 494 * 1. */ 495 static int check_and_mark_free_block(struct NFTLrecord *nftl, int block) 496 { 497 struct mtd_info *mtd = nftl->mbd.mtd; 498 struct nftl_uci1 h1; 499 unsigned int erase_mark; 500 size_t retlen; 501 502 /* check erase mark. */ 503 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8, 504 &retlen, (char *)&h1) < 0) 505 return -1; 506 507 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); 508 if (erase_mark != ERASE_MARK) { 509 /* if no erase mark, the block must be totally free. This is 510 possible in two cases : empty filesystem or interrupted erase (very unlikely) */ 511 if (check_free_sectors (nftl, block * nftl->EraseSize, nftl->EraseSize, 1) != 0) 512 return -1; 513 514 /* free block : write erase mark */ 515 h1.EraseMark = cpu_to_le16(ERASE_MARK); 516 h1.EraseMark1 = cpu_to_le16(ERASE_MARK); 517 h1.WearInfo = cpu_to_le32(0); 518 if (nftl_write_oob(mtd, 519 block * nftl->EraseSize + SECTORSIZE + 8, 8, 520 &retlen, (char *)&h1) < 0) 521 return -1; 522 } else { 523 #if 0 524 /* if erase mark present, need to skip it when doing check */ 525 for (i = 0; i < nftl->EraseSize; i += SECTORSIZE) { 526 /* check free sector */ 527 if (check_free_sectors (nftl, block * nftl->EraseSize + i, 528 SECTORSIZE, 0) != 0) 529 return -1; 530 531 if (nftl_read_oob(mtd, block * nftl->EraseSize + i, 532 16, &retlen, buf) < 0) 533 return -1; 534 if (i == SECTORSIZE) { 535 /* skip erase mark */ 536 if (memcmpb(buf, 0xff, 8)) 537 return -1; 538 } else { 539 if (memcmpb(buf, 0xff, 16)) 540 return -1; 541 } 542 } 543 #endif 544 } 545 546 return 0; 547 } 548 549 /* get_fold_mark: Read fold mark from Unit Control Information #2, we use FOLD_MARK_IN_PROGRESS 550 * to indicate that we are in the progression of a Virtual Unit Chain folding. If the UCI #2 551 * is FOLD_MARK_IN_PROGRESS when mounting the NFTL, the (previous) folding process is interrupted 552 * for some reason. A clean up/check of the VUC is necessary in this case. 553 * 554 * WARNING: return 0 if read error 555 */ 556 static int get_fold_mark(struct NFTLrecord *nftl, unsigned int block) 557 { 558 struct mtd_info *mtd = nftl->mbd.mtd; 559 struct nftl_uci2 uci; 560 size_t retlen; 561 562 if (nftl_read_oob(mtd, block * nftl->EraseSize + 2 * SECTORSIZE + 8, 563 8, &retlen, (char *)&uci) < 0) 564 return 0; 565 566 return le16_to_cpu((uci.FoldMark | uci.FoldMark1)); 567 } 568 569 int NFTL_mount(struct NFTLrecord *s) 570 { 571 int i; 572 unsigned int first_logical_block, logical_block, rep_block, nb_erases, erase_mark; 573 unsigned int block, first_block, is_first_block; 574 int chain_length, do_format_chain; 575 struct nftl_uci0 h0; 576 struct nftl_uci1 h1; 577 struct mtd_info *mtd = s->mbd.mtd; 578 size_t retlen; 579 580 /* search for NFTL MediaHeader and Spare NFTL Media Header */ 581 if (find_boot_record(s) < 0) { 582 printk("Could not find valid boot record\n"); 583 return -1; 584 } 585 586 /* init the logical to physical table */ 587 for (i = 0; i < s->nb_blocks; i++) { 588 s->EUNtable[i] = BLOCK_NIL; 589 } 590 591 /* first pass : explore each block chain */ 592 first_logical_block = 0; 593 for (first_block = 0; first_block < s->nb_blocks; first_block++) { 594 /* if the block was not already explored, we can look at it */ 595 if (s->ReplUnitTable[first_block] == BLOCK_NOTEXPLORED) { 596 block = first_block; 597 chain_length = 0; 598 do_format_chain = 0; 599 600 for (;;) { 601 /* read the block header. If error, we format the chain */ 602 if (nftl_read_oob(mtd, 603 block * s->EraseSize + 8, 8, 604 &retlen, (char *)&h0) < 0 || 605 nftl_read_oob(mtd, 606 block * s->EraseSize + 607 SECTORSIZE + 8, 8, 608 &retlen, (char *)&h1) < 0) { 609 s->ReplUnitTable[block] = BLOCK_NIL; 610 do_format_chain = 1; 611 break; 612 } 613 614 logical_block = le16_to_cpu ((h0.VirtUnitNum | h0.SpareVirtUnitNum)); 615 rep_block = le16_to_cpu ((h0.ReplUnitNum | h0.SpareReplUnitNum)); 616 nb_erases = le32_to_cpu (h1.WearInfo); 617 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1)); 618 619 is_first_block = !(logical_block >> 15); 620 logical_block = logical_block & 0x7fff; 621 622 /* invalid/free block test */ 623 if (erase_mark != ERASE_MARK || logical_block >= s->nb_blocks) { 624 if (chain_length == 0) { 625 /* if not currently in a chain, we can handle it safely */ 626 if (check_and_mark_free_block(s, block) < 0) { 627 /* not really free: format it */ 628 printk("Formatting block %d\n", block); 629 if (NFTL_formatblock(s, block) < 0) { 630 /* could not format: reserve the block */ 631 s->ReplUnitTable[block] = BLOCK_RESERVED; 632 } else { 633 s->ReplUnitTable[block] = BLOCK_FREE; 634 } 635 } else { 636 /* free block: mark it */ 637 s->ReplUnitTable[block] = BLOCK_FREE; 638 } 639 /* directly examine the next block. */ 640 goto examine_ReplUnitTable; 641 } else { 642 /* the block was in a chain : this is bad. We 643 must format all the chain */ 644 printk("Block %d: free but referenced in chain %d\n", 645 block, first_block); 646 s->ReplUnitTable[block] = BLOCK_NIL; 647 do_format_chain = 1; 648 break; 649 } 650 } 651 652 /* we accept only first blocks here */ 653 if (chain_length == 0) { 654 /* this block is not the first block in chain : 655 ignore it, it will be included in a chain 656 later, or marked as not explored */ 657 if (!is_first_block) 658 goto examine_ReplUnitTable; 659 first_logical_block = logical_block; 660 } else { 661 if (logical_block != first_logical_block) { 662 printk("Block %d: incorrect logical block: %d expected: %d\n", 663 block, logical_block, first_logical_block); 664 /* the chain is incorrect : we must format it, 665 but we need to read it completely */ 666 do_format_chain = 1; 667 } 668 if (is_first_block) { 669 /* we accept that a block is marked as first 670 block while being last block in a chain 671 only if the chain is being folded */ 672 if (get_fold_mark(s, block) != FOLD_MARK_IN_PROGRESS || 673 rep_block != 0xffff) { 674 printk("Block %d: incorrectly marked as first block in chain\n", 675 block); 676 /* the chain is incorrect : we must format it, 677 but we need to read it completely */ 678 do_format_chain = 1; 679 } else { 680 printk("Block %d: folding in progress - ignoring first block flag\n", 681 block); 682 } 683 } 684 } 685 chain_length++; 686 if (rep_block == 0xffff) { 687 /* no more blocks after */ 688 s->ReplUnitTable[block] = BLOCK_NIL; 689 break; 690 } else if (rep_block >= s->nb_blocks) { 691 printk("Block %d: referencing invalid block %d\n", 692 block, rep_block); 693 do_format_chain = 1; 694 s->ReplUnitTable[block] = BLOCK_NIL; 695 break; 696 } else if (s->ReplUnitTable[rep_block] != BLOCK_NOTEXPLORED) { 697 /* same problem as previous 'is_first_block' test: 698 we accept that the last block of a chain has 699 the first_block flag set if folding is in 700 progress. We handle here the case where the 701 last block appeared first */ 702 if (s->ReplUnitTable[rep_block] == BLOCK_NIL && 703 s->EUNtable[first_logical_block] == rep_block && 704 get_fold_mark(s, first_block) == FOLD_MARK_IN_PROGRESS) { 705 /* EUNtable[] will be set after */ 706 printk("Block %d: folding in progress - ignoring first block flag\n", 707 rep_block); 708 s->ReplUnitTable[block] = rep_block; 709 s->EUNtable[first_logical_block] = BLOCK_NIL; 710 } else { 711 printk("Block %d: referencing block %d already in another chain\n", 712 block, rep_block); 713 /* XXX: should handle correctly fold in progress chains */ 714 do_format_chain = 1; 715 s->ReplUnitTable[block] = BLOCK_NIL; 716 } 717 break; 718 } else { 719 /* this is OK */ 720 s->ReplUnitTable[block] = rep_block; 721 block = rep_block; 722 } 723 } 724 725 /* the chain was completely explored. Now we can decide 726 what to do with it */ 727 if (do_format_chain) { 728 /* invalid chain : format it */ 729 format_chain(s, first_block); 730 } else { 731 unsigned int first_block1, chain_to_format, chain_length1; 732 int fold_mark; 733 734 /* valid chain : get foldmark */ 735 fold_mark = get_fold_mark(s, first_block); 736 if (fold_mark == 0) { 737 /* cannot get foldmark : format the chain */ 738 printk("Could read foldmark at block %d\n", first_block); 739 format_chain(s, first_block); 740 } else { 741 if (fold_mark == FOLD_MARK_IN_PROGRESS) 742 check_sectors_in_chain(s, first_block); 743 744 /* now handle the case where we find two chains at the 745 same virtual address : we select the longer one, 746 because the shorter one is the one which was being 747 folded if the folding was not done in place */ 748 first_block1 = s->EUNtable[first_logical_block]; 749 if (first_block1 != BLOCK_NIL) { 750 /* XXX: what to do if same length ? */ 751 chain_length1 = calc_chain_length(s, first_block1); 752 printk("Two chains at blocks %d (len=%d) and %d (len=%d)\n", 753 first_block1, chain_length1, first_block, chain_length); 754 755 if (chain_length >= chain_length1) { 756 chain_to_format = first_block1; 757 s->EUNtable[first_logical_block] = first_block; 758 } else { 759 chain_to_format = first_block; 760 } 761 format_chain(s, chain_to_format); 762 } else { 763 s->EUNtable[first_logical_block] = first_block; 764 } 765 } 766 } 767 } 768 examine_ReplUnitTable:; 769 } 770 771 /* second pass to format unreferenced blocks and init free block count */ 772 s->numfreeEUNs = 0; 773 s->LastFreeEUN = le16_to_cpu(s->MediaHdr.FirstPhysicalEUN); 774 775 for (block = 0; block < s->nb_blocks; block++) { 776 if (s->ReplUnitTable[block] == BLOCK_NOTEXPLORED) { 777 printk("Unreferenced block %d, formatting it\n", block); 778 if (NFTL_formatblock(s, block) < 0) 779 s->ReplUnitTable[block] = BLOCK_RESERVED; 780 else 781 s->ReplUnitTable[block] = BLOCK_FREE; 782 } 783 if (s->ReplUnitTable[block] == BLOCK_FREE) { 784 s->numfreeEUNs++; 785 s->LastFreeEUN = block; 786 } 787 } 788 789 return 0; 790 } 791