xref: /linux/drivers/mtd/inftlmount.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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, SECTORSIZE,
77 			       &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, SECTORSIZE,
122 			 &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 (mtd_block_isbad(inftl->mbd.mtd,
310 						    i * inftl->EraseSize + physblock))
311 					inftl->PUtable[i] = BLOCK_RESERVED;
312 			}
313 		}
314 
315 		inftl->MediaUnit = block;
316 		return 0;
317 	}
318 
319 	/* Not found. */
320 	return -1;
321 }
322 
323 static int memcmpb(void *a, int c, int n)
324 {
325 	int i;
326 	for (i = 0; i < n; i++) {
327 		if (c != ((unsigned char *)a)[i])
328 			return 1;
329 	}
330 	return 0;
331 }
332 
333 /*
334  * check_free_sector: check if a free sector is actually FREE,
335  *	i.e. All 0xff in data and oob area.
336  */
337 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
338 	int len, int check_oob)
339 {
340 	u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
341 	struct mtd_info *mtd = inftl->mbd.mtd;
342 	size_t retlen;
343 	int i;
344 
345 	for (i = 0; i < len; i += SECTORSIZE) {
346 		if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
347 			return -1;
348 		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
349 			return -1;
350 
351 		if (check_oob) {
352 			if(inftl_read_oob(mtd, address, mtd->oobsize,
353 					  &retlen, &buf[SECTORSIZE]) < 0)
354 				return -1;
355 			if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
356 				return -1;
357 		}
358 		address += SECTORSIZE;
359 	}
360 
361 	return 0;
362 }
363 
364 /*
365  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
366  *		 Unit and Update INFTL metadata. Each erase operation is
367  *		 checked with check_free_sectors.
368  *
369  * Return: 0 when succeed, -1 on error.
370  *
371  * ToDo: 1. Is it necessary to check_free_sector after erasing ??
372  */
373 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
374 {
375 	size_t retlen;
376 	struct inftl_unittail uci;
377 	struct erase_info *instr = &inftl->instr;
378 	struct mtd_info *mtd = inftl->mbd.mtd;
379 	int physblock;
380 
381 	pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);
382 
383 	memset(instr, 0, sizeof(struct erase_info));
384 
385 	/* FIXME: Shouldn't we be setting the 'discarded' flag to zero
386 	   _first_? */
387 
388 	/* Use async erase interface, test return code */
389 	instr->mtd = inftl->mbd.mtd;
390 	instr->addr = block * inftl->EraseSize;
391 	instr->len = inftl->mbd.mtd->erasesize;
392 	/* Erase one physical eraseblock at a time, even though the NAND api
393 	   allows us to group them.  This way we if we have a failure, we can
394 	   mark only the failed block in the bbt. */
395 	for (physblock = 0; physblock < inftl->EraseSize;
396 	     physblock += instr->len, instr->addr += instr->len) {
397 		mtd_erase(inftl->mbd.mtd, instr);
398 
399 		if (instr->state == MTD_ERASE_FAILED) {
400 			printk(KERN_WARNING "INFTL: error while formatting block %d\n",
401 				block);
402 			goto fail;
403 		}
404 
405 		/*
406 		 * Check the "freeness" of Erase Unit before updating metadata.
407 		 * FixMe: is this check really necessary? Since we have check
408 		 * the return code after the erase operation.
409 		 */
410 		if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
411 			goto fail;
412 	}
413 
414 	uci.EraseMark = cpu_to_le16(ERASE_MARK);
415 	uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
416 	uci.Reserved[0] = 0;
417 	uci.Reserved[1] = 0;
418 	uci.Reserved[2] = 0;
419 	uci.Reserved[3] = 0;
420 	instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
421 	if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
422 		goto fail;
423 	return 0;
424 fail:
425 	/* could not format, update the bad block table (caller is responsible
426 	   for setting the PUtable to BLOCK_RESERVED on failure) */
427 	mtd_block_markbad(inftl->mbd.mtd, instr->addr);
428 	return -1;
429 }
430 
431 /*
432  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
433  *	Units in a Virtual Unit Chain, i.e. all the units are disconnected.
434  *
435  *	Since the chain is invalid then we will have to erase it from its
436  *	head (normally for INFTL we go from the oldest). But if it has a
437  *	loop then there is no oldest...
438  */
439 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
440 {
441 	unsigned int block = first_block, block1;
442 
443 	printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
444 		first_block);
445 
446 	for (;;) {
447 		block1 = inftl->PUtable[block];
448 
449 		printk(KERN_WARNING "INFTL: formatting block %d\n", block);
450 		if (INFTL_formatblock(inftl, block) < 0) {
451 			/*
452 			 * Cannot format !!!! Mark it as Bad Unit,
453 			 */
454 			inftl->PUtable[block] = BLOCK_RESERVED;
455 		} else {
456 			inftl->PUtable[block] = BLOCK_FREE;
457 		}
458 
459 		/* Goto next block on the chain */
460 		block = block1;
461 
462 		if (block == BLOCK_NIL || block >= inftl->lastEUN)
463 			break;
464 	}
465 }
466 
467 void INFTL_dumptables(struct INFTLrecord *s)
468 {
469 	int i;
470 
471 	pr_debug("-------------------------------------------"
472 		"----------------------------------\n");
473 
474 	pr_debug("VUtable[%d] ->", s->nb_blocks);
475 	for (i = 0; i < s->nb_blocks; i++) {
476 		if ((i % 8) == 0)
477 			pr_debug("\n%04x: ", i);
478 		pr_debug("%04x ", s->VUtable[i]);
479 	}
480 
481 	pr_debug("\n-------------------------------------------"
482 		"----------------------------------\n");
483 
484 	pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
485 	for (i = 0; i <= s->lastEUN; i++) {
486 		if ((i % 8) == 0)
487 			pr_debug("\n%04x: ", i);
488 		pr_debug("%04x ", s->PUtable[i]);
489 	}
490 
491 	pr_debug("\n-------------------------------------------"
492 		"----------------------------------\n");
493 
494 	pr_debug("INFTL ->\n"
495 		"  EraseSize       = %d\n"
496 		"  h/s/c           = %d/%d/%d\n"
497 		"  numvunits       = %d\n"
498 		"  firstEUN        = %d\n"
499 		"  lastEUN         = %d\n"
500 		"  numfreeEUNs     = %d\n"
501 		"  LastFreeEUN     = %d\n"
502 		"  nb_blocks       = %d\n"
503 		"  nb_boot_blocks  = %d",
504 		s->EraseSize, s->heads, s->sectors, s->cylinders,
505 		s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
506 		s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
507 
508 	pr_debug("\n-------------------------------------------"
509 		"----------------------------------\n");
510 }
511 
512 void INFTL_dumpVUchains(struct INFTLrecord *s)
513 {
514 	int logical, block, i;
515 
516 	pr_debug("-------------------------------------------"
517 		"----------------------------------\n");
518 
519 	pr_debug("INFTL Virtual Unit Chains:\n");
520 	for (logical = 0; logical < s->nb_blocks; logical++) {
521 		block = s->VUtable[logical];
522 		if (block > s->nb_blocks)
523 			continue;
524 		pr_debug("  LOGICAL %d --> %d ", logical, block);
525 		for (i = 0; i < s->nb_blocks; i++) {
526 			if (s->PUtable[block] == BLOCK_NIL)
527 				break;
528 			block = s->PUtable[block];
529 			pr_debug("%d ", block);
530 		}
531 		pr_debug("\n");
532 	}
533 
534 	pr_debug("-------------------------------------------"
535 		"----------------------------------\n");
536 }
537 
538 int INFTL_mount(struct INFTLrecord *s)
539 {
540 	struct mtd_info *mtd = s->mbd.mtd;
541 	unsigned int block, first_block, prev_block, last_block;
542 	unsigned int first_logical_block, logical_block, erase_mark;
543 	int chain_length, do_format_chain;
544 	struct inftl_unithead1 h0;
545 	struct inftl_unittail h1;
546 	size_t retlen;
547 	int i;
548 	u8 *ANACtable, ANAC;
549 
550 	pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);
551 
552 	/* Search for INFTL MediaHeader and Spare INFTL Media Header */
553 	if (find_boot_record(s) < 0) {
554 		printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
555 		return -ENXIO;
556 	}
557 
558 	/* Init the logical to physical table */
559 	for (i = 0; i < s->nb_blocks; i++)
560 		s->VUtable[i] = BLOCK_NIL;
561 
562 	logical_block = block = BLOCK_NIL;
563 
564 	/* Temporary buffer to store ANAC numbers. */
565 	ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
566 	if (!ANACtable) {
567 		printk(KERN_WARNING "INFTL: allocation of ANACtable "
568 				"failed (%zd bytes)\n",
569 				s->nb_blocks * sizeof(u8));
570 		return -ENOMEM;
571 	}
572 
573 	/*
574 	 * First pass is to explore each physical unit, and construct the
575 	 * virtual chains that exist (newest physical unit goes into VUtable).
576 	 * Any block that is in any way invalid will be left in the
577 	 * NOTEXPLORED state. Then at the end we will try to format it and
578 	 * mark it as free.
579 	 */
580 	pr_debug("INFTL: pass 1, explore each unit\n");
581 	for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
582 		if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
583 			continue;
584 
585 		do_format_chain = 0;
586 		first_logical_block = BLOCK_NIL;
587 		last_block = BLOCK_NIL;
588 		block = first_block;
589 
590 		for (chain_length = 0; ; chain_length++) {
591 
592 			if ((chain_length == 0) &&
593 			    (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
594 				/* Nothing to do here, onto next block */
595 				break;
596 			}
597 
598 			if (inftl_read_oob(mtd, block * s->EraseSize + 8,
599 					   8, &retlen, (char *)&h0) < 0 ||
600 			    inftl_read_oob(mtd, block * s->EraseSize +
601 					   2 * SECTORSIZE + 8, 8, &retlen,
602 					   (char *)&h1) < 0) {
603 				/* Should never happen? */
604 				do_format_chain++;
605 				break;
606 			}
607 
608 			logical_block = le16_to_cpu(h0.virtualUnitNo);
609 			prev_block = le16_to_cpu(h0.prevUnitNo);
610 			erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
611 			ANACtable[block] = h0.ANAC;
612 
613 			/* Previous block is relative to start of Partition */
614 			if (prev_block < s->nb_blocks)
615 				prev_block += s->firstEUN;
616 
617 			/* Already explored partial chain? */
618 			if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
619 				/* Check if chain for this logical */
620 				if (logical_block == first_logical_block) {
621 					if (last_block != BLOCK_NIL)
622 						s->PUtable[last_block] = block;
623 				}
624 				break;
625 			}
626 
627 			/* Check for invalid block */
628 			if (erase_mark != ERASE_MARK) {
629 				printk(KERN_WARNING "INFTL: corrupt block %d "
630 					"in chain %d, chain length %d, erase "
631 					"mark 0x%x?\n", block, first_block,
632 					chain_length, erase_mark);
633 				/*
634 				 * Assume end of chain, probably incomplete
635 				 * fold/erase...
636 				 */
637 				if (chain_length == 0)
638 					do_format_chain++;
639 				break;
640 			}
641 
642 			/* Check for it being free already then... */
643 			if ((logical_block == BLOCK_FREE) ||
644 			    (logical_block == BLOCK_NIL)) {
645 				s->PUtable[block] = BLOCK_FREE;
646 				break;
647 			}
648 
649 			/* Sanity checks on block numbers */
650 			if ((logical_block >= s->nb_blocks) ||
651 			    ((prev_block >= s->nb_blocks) &&
652 			     (prev_block != BLOCK_NIL))) {
653 				if (chain_length > 0) {
654 					printk(KERN_WARNING "INFTL: corrupt "
655 						"block %d in chain %d?\n",
656 						block, first_block);
657 					do_format_chain++;
658 				}
659 				break;
660 			}
661 
662 			if (first_logical_block == BLOCK_NIL) {
663 				first_logical_block = logical_block;
664 			} else {
665 				if (first_logical_block != logical_block) {
666 					/* Normal for folded chain... */
667 					break;
668 				}
669 			}
670 
671 			/*
672 			 * Current block is valid, so if we followed a virtual
673 			 * chain to get here then we can set the previous
674 			 * block pointer in our PUtable now. Then move onto
675 			 * the previous block in the chain.
676 			 */
677 			s->PUtable[block] = BLOCK_NIL;
678 			if (last_block != BLOCK_NIL)
679 				s->PUtable[last_block] = block;
680 			last_block = block;
681 			block = prev_block;
682 
683 			/* Check for end of chain */
684 			if (block == BLOCK_NIL)
685 				break;
686 
687 			/* Validate next block before following it... */
688 			if (block > s->lastEUN) {
689 				printk(KERN_WARNING "INFTL: invalid previous "
690 					"block %d in chain %d?\n", block,
691 					first_block);
692 				do_format_chain++;
693 				break;
694 			}
695 		}
696 
697 		if (do_format_chain) {
698 			format_chain(s, first_block);
699 			continue;
700 		}
701 
702 		/*
703 		 * Looks like a valid chain then. It may not really be the
704 		 * newest block in the chain, but it is the newest we have
705 		 * found so far. We might update it in later iterations of
706 		 * this loop if we find something newer.
707 		 */
708 		s->VUtable[first_logical_block] = first_block;
709 		logical_block = BLOCK_NIL;
710 	}
711 
712 	INFTL_dumptables(s);
713 
714 	/*
715 	 * Second pass, check for infinite loops in chains. These are
716 	 * possible because we don't update the previous pointers when
717 	 * we fold chains. No big deal, just fix them up in PUtable.
718 	 */
719 	pr_debug("INFTL: pass 2, validate virtual chains\n");
720 	for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
721 		block = s->VUtable[logical_block];
722 		last_block = BLOCK_NIL;
723 
724 		/* Check for free/reserved/nil */
725 		if (block >= BLOCK_RESERVED)
726 			continue;
727 
728 		ANAC = ANACtable[block];
729 		for (i = 0; i < s->numvunits; i++) {
730 			if (s->PUtable[block] == BLOCK_NIL)
731 				break;
732 			if (s->PUtable[block] > s->lastEUN) {
733 				printk(KERN_WARNING "INFTL: invalid prev %d, "
734 					"in virtual chain %d\n",
735 					s->PUtable[block], logical_block);
736 				s->PUtable[block] = BLOCK_NIL;
737 
738 			}
739 			if (ANACtable[block] != ANAC) {
740 				/*
741 				 * Chain must point back to itself. This is ok,
742 				 * but we will need adjust the tables with this
743 				 * newest block and oldest block.
744 				 */
745 				s->VUtable[logical_block] = block;
746 				s->PUtable[last_block] = BLOCK_NIL;
747 				break;
748 			}
749 
750 			ANAC--;
751 			last_block = block;
752 			block = s->PUtable[block];
753 		}
754 
755 		if (i >= s->nb_blocks) {
756 			/*
757 			 * Uhoo, infinite chain with valid ANACS!
758 			 * Format whole chain...
759 			 */
760 			format_chain(s, first_block);
761 		}
762 	}
763 
764 	INFTL_dumptables(s);
765 	INFTL_dumpVUchains(s);
766 
767 	/*
768 	 * Third pass, format unreferenced blocks and init free block count.
769 	 */
770 	s->numfreeEUNs = 0;
771 	s->LastFreeEUN = BLOCK_NIL;
772 
773 	pr_debug("INFTL: pass 3, format unused blocks\n");
774 	for (block = s->firstEUN; block <= s->lastEUN; block++) {
775 		if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
776 			printk("INFTL: unreferenced block %d, formatting it\n",
777 				block);
778 			if (INFTL_formatblock(s, block) < 0)
779 				s->PUtable[block] = BLOCK_RESERVED;
780 			else
781 				s->PUtable[block] = BLOCK_FREE;
782 		}
783 		if (s->PUtable[block] == BLOCK_FREE) {
784 			s->numfreeEUNs++;
785 			if (s->LastFreeEUN == BLOCK_NIL)
786 				s->LastFreeEUN = block;
787 		}
788 	}
789 
790 	kfree(ANACtable);
791 	return 0;
792 }
793