xref: /openbmc/linux/drivers/mtd/inftlmount.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * inftlmount.c -- INFTL mount code with extensive checks.
4  *
5  * Author: Greg Ungerer (gerg@snapgear.com)
6  * Copyright © 2002-2003, Greg Ungerer (gerg@snapgear.com)
7  *
8  * Based heavily on the nftlmount.c code which is:
9  * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
10  * Copyright © 2000 Netgem S.A.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <asm/errno.h>
16 #include <asm/io.h>
17 #include <linux/uaccess.h>
18 #include <linux/delay.h>
19 #include <linux/slab.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/nftl.h>
22 #include <linux/mtd/inftl.h>
23 
24 /*
25  * find_boot_record: Find the INFTL Media Header and its Spare copy which
26  *	contains the various device information of the INFTL partition and
27  *	Bad Unit Table. Update the PUtable[] table according to the Bad
28  *	Unit Table. PUtable[] is used for management of Erase Unit in
29  *	other routines in inftlcore.c and inftlmount.c.
30  */
31 static int find_boot_record(struct INFTLrecord *inftl)
32 {
33 	struct inftl_unittail h1;
34 	//struct inftl_oob oob;
35 	unsigned int i, block;
36 	u8 buf[SECTORSIZE];
37 	struct INFTLMediaHeader *mh = &inftl->MediaHdr;
38 	struct mtd_info *mtd = inftl->mbd.mtd;
39 	struct INFTLPartition *ip;
40 	size_t retlen;
41 
42 	pr_debug("INFTL: find_boot_record(inftl=%p)\n", inftl);
43 
44         /*
45 	 * Assume logical EraseSize == physical erasesize for starting the
46 	 * scan. We'll sort it out later if we find a MediaHeader which says
47 	 * otherwise.
48 	 */
49 	inftl->EraseSize = inftl->mbd.mtd->erasesize;
50         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
51 
52 	inftl->MediaUnit = BLOCK_NIL;
53 
54 	/* Search for a valid boot record */
55 	for (block = 0; block < inftl->nb_blocks; block++) {
56 		int ret;
57 
58 		/*
59 		 * Check for BNAND header first. Then whinge if it's found
60 		 * but later checks fail.
61 		 */
62 		ret = mtd_read(mtd, block * inftl->EraseSize, SECTORSIZE,
63 			       &retlen, buf);
64 		/* We ignore ret in case the ECC of the MediaHeader is invalid
65 		   (which is apparently acceptable) */
66 		if (retlen != SECTORSIZE) {
67 			static int warncount = 5;
68 
69 			if (warncount) {
70 				printk(KERN_WARNING "INFTL: block read at 0x%x "
71 					"of mtd%d failed: %d\n",
72 					block * inftl->EraseSize,
73 					inftl->mbd.mtd->index, ret);
74 				if (!--warncount)
75 					printk(KERN_WARNING "INFTL: further "
76 						"failures for this block will "
77 						"not be printed\n");
78 			}
79 			continue;
80 		}
81 
82 		if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
83 			/* BNAND\0 not found. Continue */
84 			continue;
85 		}
86 
87 		/* To be safer with BIOS, also use erase mark as discriminant */
88 		ret = inftl_read_oob(mtd,
89 				     block * inftl->EraseSize + SECTORSIZE + 8,
90 				     8, &retlen,(char *)&h1);
91 		if (ret < 0) {
92 			printk(KERN_WARNING "INFTL: ANAND header found at "
93 				"0x%x in mtd%d, but OOB data read failed "
94 				"(err %d)\n", block * inftl->EraseSize,
95 				inftl->mbd.mtd->index, ret);
96 			continue;
97 		}
98 
99 
100 		/*
101 		 * This is the first we've seen.
102 		 * Copy the media header structure into place.
103 		 */
104 		memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
105 
106 		/* Read the spare media header at offset 4096 */
107 		mtd_read(mtd, block * inftl->EraseSize + 4096, SECTORSIZE,
108 			 &retlen, buf);
109 		if (retlen != SECTORSIZE) {
110 			printk(KERN_WARNING "INFTL: Unable to read spare "
111 			       "Media Header\n");
112 			return -1;
113 		}
114 		/* Check if this one is the same as the first one we found. */
115 		if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
116 			printk(KERN_WARNING "INFTL: Primary and spare Media "
117 			       "Headers disagree.\n");
118 			return -1;
119 		}
120 
121 		mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
122 		mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
123 		mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
124 		mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
125 		mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
126 		mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
127 
128 		pr_debug("INFTL: Media Header ->\n"
129 			 "    bootRecordID          = %s\n"
130 			 "    NoOfBootImageBlocks   = %d\n"
131 			 "    NoOfBinaryPartitions  = %d\n"
132 			 "    NoOfBDTLPartitions    = %d\n"
133 			 "    BlockMultiplierBits   = %d\n"
134 			 "    FormatFlgs            = %d\n"
135 			 "    OsakVersion           = 0x%x\n"
136 			 "    PercentUsed           = %d\n",
137 			 mh->bootRecordID, mh->NoOfBootImageBlocks,
138 			 mh->NoOfBinaryPartitions,
139 			 mh->NoOfBDTLPartitions,
140 			 mh->BlockMultiplierBits, mh->FormatFlags,
141 			 mh->OsakVersion, mh->PercentUsed);
142 
143 		if (mh->NoOfBDTLPartitions == 0) {
144 			printk(KERN_WARNING "INFTL: Media Header sanity check "
145 				"failed: NoOfBDTLPartitions (%d) == 0, "
146 				"must be at least 1\n", mh->NoOfBDTLPartitions);
147 			return -1;
148 		}
149 
150 		if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
151 			printk(KERN_WARNING "INFTL: Media Header sanity check "
152 				"failed: Total Partitions (%d) > 4, "
153 				"BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
154 				mh->NoOfBinaryPartitions,
155 				mh->NoOfBDTLPartitions,
156 				mh->NoOfBinaryPartitions);
157 			return -1;
158 		}
159 
160 		if (mh->BlockMultiplierBits > 1) {
161 			printk(KERN_WARNING "INFTL: sorry, we don't support "
162 				"UnitSizeFactor 0x%02x\n",
163 				mh->BlockMultiplierBits);
164 			return -1;
165 		} else if (mh->BlockMultiplierBits == 1) {
166 			printk(KERN_WARNING "INFTL: support for INFTL with "
167 				"UnitSizeFactor 0x%02x is experimental\n",
168 				mh->BlockMultiplierBits);
169 			inftl->EraseSize = inftl->mbd.mtd->erasesize <<
170 				mh->BlockMultiplierBits;
171 			inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
172 			block >>= mh->BlockMultiplierBits;
173 		}
174 
175 		/* Scan the partitions */
176 		for (i = 0; (i < 4); i++) {
177 			ip = &mh->Partitions[i];
178 			ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
179 			ip->firstUnit = le32_to_cpu(ip->firstUnit);
180 			ip->lastUnit = le32_to_cpu(ip->lastUnit);
181 			ip->flags = le32_to_cpu(ip->flags);
182 			ip->spareUnits = le32_to_cpu(ip->spareUnits);
183 			ip->Reserved0 = le32_to_cpu(ip->Reserved0);
184 
185 			pr_debug("    PARTITION[%d] ->\n"
186 				 "        virtualUnits    = %d\n"
187 				 "        firstUnit       = %d\n"
188 				 "        lastUnit        = %d\n"
189 				 "        flags           = 0x%x\n"
190 				 "        spareUnits      = %d\n",
191 				 i, ip->virtualUnits, ip->firstUnit,
192 				 ip->lastUnit, ip->flags,
193 				 ip->spareUnits);
194 
195 			if (ip->Reserved0 != ip->firstUnit) {
196 				struct erase_info *instr = &inftl->instr;
197 
198 				/*
199 				 * 	Most likely this is using the
200 				 * 	undocumented qiuck mount feature.
201 				 * 	We don't support that, we will need
202 				 * 	to erase the hidden block for full
203 				 * 	compatibility.
204 				 */
205 				instr->addr = ip->Reserved0 * inftl->EraseSize;
206 				instr->len = inftl->EraseSize;
207 				mtd_erase(mtd, instr);
208 			}
209 			if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
210 				printk(KERN_WARNING "INFTL: Media Header "
211 					"Partition %d sanity check failed\n"
212 					"    firstUnit %d : lastUnit %d  >  "
213 					"virtualUnits %d\n", i, ip->lastUnit,
214 					ip->firstUnit, ip->Reserved0);
215 				return -1;
216 			}
217 			if (ip->Reserved1 != 0) {
218 				printk(KERN_WARNING "INFTL: Media Header "
219 					"Partition %d sanity check failed: "
220 					"Reserved1 %d != 0\n",
221 					i, ip->Reserved1);
222 				return -1;
223 			}
224 
225 			if (ip->flags & INFTL_BDTL)
226 				break;
227 		}
228 
229 		if (i >= 4) {
230 			printk(KERN_WARNING "INFTL: Media Header Partition "
231 				"sanity check failed:\n       No partition "
232 				"marked as Disk Partition\n");
233 			return -1;
234 		}
235 
236 		inftl->nb_boot_blocks = ip->firstUnit;
237 		inftl->numvunits = ip->virtualUnits;
238 		if (inftl->numvunits > (inftl->nb_blocks -
239 		    inftl->nb_boot_blocks - 2)) {
240 			printk(KERN_WARNING "INFTL: Media Header sanity check "
241 				"failed:\n        numvunits (%d) > nb_blocks "
242 				"(%d) - nb_boot_blocks(%d) - 2\n",
243 				inftl->numvunits, inftl->nb_blocks,
244 				inftl->nb_boot_blocks);
245 			return -1;
246 		}
247 
248 		inftl->mbd.size  = inftl->numvunits *
249 			(inftl->EraseSize / SECTORSIZE);
250 
251 		/*
252 		 * Block count is set to last used EUN (we won't need to keep
253 		 * any meta-data past that point).
254 		 */
255 		inftl->firstEUN = ip->firstUnit;
256 		inftl->lastEUN = ip->lastUnit;
257 		inftl->nb_blocks = ip->lastUnit + 1;
258 
259 		/* Memory alloc */
260 		inftl->PUtable = kmalloc_array(inftl->nb_blocks, sizeof(u16),
261 					       GFP_KERNEL);
262 		if (!inftl->PUtable)
263 			return -ENOMEM;
264 
265 		inftl->VUtable = kmalloc_array(inftl->nb_blocks, sizeof(u16),
266 					       GFP_KERNEL);
267 		if (!inftl->VUtable) {
268 			kfree(inftl->PUtable);
269 			return -ENOMEM;
270 		}
271 
272 		/* Mark the blocks before INFTL MediaHeader as reserved */
273 		for (i = 0; i < inftl->nb_boot_blocks; i++)
274 			inftl->PUtable[i] = BLOCK_RESERVED;
275 		/* Mark all remaining blocks as potentially containing data */
276 		for (; i < inftl->nb_blocks; i++)
277 			inftl->PUtable[i] = BLOCK_NOTEXPLORED;
278 
279 		/* Mark this boot record (NFTL MediaHeader) block as reserved */
280 		inftl->PUtable[block] = BLOCK_RESERVED;
281 
282 		/* Read Bad Erase Unit Table and modify PUtable[] accordingly */
283 		for (i = 0; i < inftl->nb_blocks; i++) {
284 			int physblock;
285 			/* If any of the physical eraseblocks are bad, don't
286 			   use the unit. */
287 			for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
288 				if (mtd_block_isbad(inftl->mbd.mtd,
289 						    i * inftl->EraseSize + physblock))
290 					inftl->PUtable[i] = BLOCK_RESERVED;
291 			}
292 		}
293 
294 		inftl->MediaUnit = block;
295 		return 0;
296 	}
297 
298 	/* Not found. */
299 	return -1;
300 }
301 
302 static int memcmpb(void *a, int c, int n)
303 {
304 	int i;
305 	for (i = 0; i < n; i++) {
306 		if (c != ((unsigned char *)a)[i])
307 			return 1;
308 	}
309 	return 0;
310 }
311 
312 /*
313  * check_free_sector: check if a free sector is actually FREE,
314  *	i.e. All 0xff in data and oob area.
315  */
316 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
317 	int len, int check_oob)
318 {
319 	struct mtd_info *mtd = inftl->mbd.mtd;
320 	size_t retlen;
321 	int i, ret;
322 	u8 *buf;
323 
324 	buf = kmalloc(SECTORSIZE + mtd->oobsize, GFP_KERNEL);
325 	if (!buf)
326 		return -ENOMEM;
327 
328 	ret = -1;
329 	for (i = 0; i < len; i += SECTORSIZE) {
330 		if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
331 			goto out;
332 		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
333 			goto out;
334 
335 		if (check_oob) {
336 			if(inftl_read_oob(mtd, address, mtd->oobsize,
337 					  &retlen, &buf[SECTORSIZE]) < 0)
338 				goto out;
339 			if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
340 				goto out;
341 		}
342 		address += SECTORSIZE;
343 	}
344 
345 	ret = 0;
346 
347 out:
348 	kfree(buf);
349 	return ret;
350 }
351 
352 /*
353  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
354  *		 Unit and Update INFTL metadata. Each erase operation is
355  *		 checked with check_free_sectors.
356  *
357  * Return: 0 when succeed, -1 on error.
358  *
359  * ToDo: 1. Is it necessary to check_free_sector after erasing ??
360  */
361 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
362 {
363 	size_t retlen;
364 	struct inftl_unittail uci;
365 	struct erase_info *instr = &inftl->instr;
366 	struct mtd_info *mtd = inftl->mbd.mtd;
367 	int physblock;
368 
369 	pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);
370 
371 	memset(instr, 0, sizeof(struct erase_info));
372 
373 	/* FIXME: Shouldn't we be setting the 'discarded' flag to zero
374 	   _first_? */
375 
376 	/* Use async erase interface, test return code */
377 	instr->addr = block * inftl->EraseSize;
378 	instr->len = inftl->mbd.mtd->erasesize;
379 	/* Erase one physical eraseblock at a time, even though the NAND api
380 	   allows us to group them.  This way we if we have a failure, we can
381 	   mark only the failed block in the bbt. */
382 	for (physblock = 0; physblock < inftl->EraseSize;
383 	     physblock += instr->len, instr->addr += instr->len) {
384 		int ret;
385 
386 		ret = mtd_erase(inftl->mbd.mtd, instr);
387 		if (ret) {
388 			printk(KERN_WARNING "INFTL: error while formatting block %d\n",
389 				block);
390 			goto fail;
391 		}
392 
393 		/*
394 		 * Check the "freeness" of Erase Unit before updating metadata.
395 		 * FixMe: is this check really necessary? Since we have check
396 		 * the return code after the erase operation.
397 		 */
398 		if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
399 			goto fail;
400 	}
401 
402 	uci.EraseMark = cpu_to_le16(ERASE_MARK);
403 	uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
404 	uci.Reserved[0] = 0;
405 	uci.Reserved[1] = 0;
406 	uci.Reserved[2] = 0;
407 	uci.Reserved[3] = 0;
408 	instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
409 	if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
410 		goto fail;
411 	return 0;
412 fail:
413 	/* could not format, update the bad block table (caller is responsible
414 	   for setting the PUtable to BLOCK_RESERVED on failure) */
415 	mtd_block_markbad(inftl->mbd.mtd, instr->addr);
416 	return -1;
417 }
418 
419 /*
420  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
421  *	Units in a Virtual Unit Chain, i.e. all the units are disconnected.
422  *
423  *	Since the chain is invalid then we will have to erase it from its
424  *	head (normally for INFTL we go from the oldest). But if it has a
425  *	loop then there is no oldest...
426  */
427 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
428 {
429 	unsigned int block = first_block, block1;
430 
431 	printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
432 		first_block);
433 
434 	for (;;) {
435 		block1 = inftl->PUtable[block];
436 
437 		printk(KERN_WARNING "INFTL: formatting block %d\n", block);
438 		if (INFTL_formatblock(inftl, block) < 0) {
439 			/*
440 			 * Cannot format !!!! Mark it as Bad Unit,
441 			 */
442 			inftl->PUtable[block] = BLOCK_RESERVED;
443 		} else {
444 			inftl->PUtable[block] = BLOCK_FREE;
445 		}
446 
447 		/* Goto next block on the chain */
448 		block = block1;
449 
450 		if (block == BLOCK_NIL || block >= inftl->lastEUN)
451 			break;
452 	}
453 }
454 
455 void INFTL_dumptables(struct INFTLrecord *s)
456 {
457 	int i;
458 
459 	pr_debug("-------------------------------------------"
460 		"----------------------------------\n");
461 
462 	pr_debug("VUtable[%d] ->", s->nb_blocks);
463 	for (i = 0; i < s->nb_blocks; i++) {
464 		if ((i % 8) == 0)
465 			pr_debug("\n%04x: ", i);
466 		pr_debug("%04x ", s->VUtable[i]);
467 	}
468 
469 	pr_debug("\n-------------------------------------------"
470 		"----------------------------------\n");
471 
472 	pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
473 	for (i = 0; i <= s->lastEUN; i++) {
474 		if ((i % 8) == 0)
475 			pr_debug("\n%04x: ", i);
476 		pr_debug("%04x ", s->PUtable[i]);
477 	}
478 
479 	pr_debug("\n-------------------------------------------"
480 		"----------------------------------\n");
481 
482 	pr_debug("INFTL ->\n"
483 		"  EraseSize       = %d\n"
484 		"  h/s/c           = %d/%d/%d\n"
485 		"  numvunits       = %d\n"
486 		"  firstEUN        = %d\n"
487 		"  lastEUN         = %d\n"
488 		"  numfreeEUNs     = %d\n"
489 		"  LastFreeEUN     = %d\n"
490 		"  nb_blocks       = %d\n"
491 		"  nb_boot_blocks  = %d",
492 		s->EraseSize, s->heads, s->sectors, s->cylinders,
493 		s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
494 		s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
495 
496 	pr_debug("\n-------------------------------------------"
497 		"----------------------------------\n");
498 }
499 
500 void INFTL_dumpVUchains(struct INFTLrecord *s)
501 {
502 	int logical, block, i;
503 
504 	pr_debug("-------------------------------------------"
505 		"----------------------------------\n");
506 
507 	pr_debug("INFTL Virtual Unit Chains:\n");
508 	for (logical = 0; logical < s->nb_blocks; logical++) {
509 		block = s->VUtable[logical];
510 		if (block >= s->nb_blocks)
511 			continue;
512 		pr_debug("  LOGICAL %d --> %d ", logical, block);
513 		for (i = 0; i < s->nb_blocks; i++) {
514 			if (s->PUtable[block] == BLOCK_NIL)
515 				break;
516 			block = s->PUtable[block];
517 			pr_debug("%d ", block);
518 		}
519 		pr_debug("\n");
520 	}
521 
522 	pr_debug("-------------------------------------------"
523 		"----------------------------------\n");
524 }
525 
526 int INFTL_mount(struct INFTLrecord *s)
527 {
528 	struct mtd_info *mtd = s->mbd.mtd;
529 	unsigned int block, first_block, prev_block, last_block;
530 	unsigned int first_logical_block, logical_block, erase_mark;
531 	int chain_length, do_format_chain;
532 	struct inftl_unithead1 h0;
533 	struct inftl_unittail h1;
534 	size_t retlen;
535 	int i;
536 	u8 *ANACtable, ANAC;
537 
538 	pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);
539 
540 	/* Search for INFTL MediaHeader and Spare INFTL Media Header */
541 	if (find_boot_record(s) < 0) {
542 		printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
543 		return -ENXIO;
544 	}
545 
546 	/* Init the logical to physical table */
547 	for (i = 0; i < s->nb_blocks; i++)
548 		s->VUtable[i] = BLOCK_NIL;
549 
550 	logical_block = block = BLOCK_NIL;
551 
552 	/* Temporary buffer to store ANAC numbers. */
553 	ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
554 	if (!ANACtable)
555 		return -ENOMEM;
556 
557 	/*
558 	 * First pass is to explore each physical unit, and construct the
559 	 * virtual chains that exist (newest physical unit goes into VUtable).
560 	 * Any block that is in any way invalid will be left in the
561 	 * NOTEXPLORED state. Then at the end we will try to format it and
562 	 * mark it as free.
563 	 */
564 	pr_debug("INFTL: pass 1, explore each unit\n");
565 	for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
566 		if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
567 			continue;
568 
569 		do_format_chain = 0;
570 		first_logical_block = BLOCK_NIL;
571 		last_block = BLOCK_NIL;
572 		block = first_block;
573 
574 		for (chain_length = 0; ; chain_length++) {
575 
576 			if ((chain_length == 0) &&
577 			    (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
578 				/* Nothing to do here, onto next block */
579 				break;
580 			}
581 
582 			if (inftl_read_oob(mtd, block * s->EraseSize + 8,
583 					   8, &retlen, (char *)&h0) < 0 ||
584 			    inftl_read_oob(mtd, block * s->EraseSize +
585 					   2 * SECTORSIZE + 8, 8, &retlen,
586 					   (char *)&h1) < 0) {
587 				/* Should never happen? */
588 				do_format_chain++;
589 				break;
590 			}
591 
592 			logical_block = le16_to_cpu(h0.virtualUnitNo);
593 			prev_block = le16_to_cpu(h0.prevUnitNo);
594 			erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
595 			ANACtable[block] = h0.ANAC;
596 
597 			/* Previous block is relative to start of Partition */
598 			if (prev_block < s->nb_blocks)
599 				prev_block += s->firstEUN;
600 
601 			/* Already explored partial chain? */
602 			if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
603 				/* Check if chain for this logical */
604 				if (logical_block == first_logical_block) {
605 					if (last_block != BLOCK_NIL)
606 						s->PUtable[last_block] = block;
607 				}
608 				break;
609 			}
610 
611 			/* Check for invalid block */
612 			if (erase_mark != ERASE_MARK) {
613 				printk(KERN_WARNING "INFTL: corrupt block %d "
614 					"in chain %d, chain length %d, erase "
615 					"mark 0x%x?\n", block, first_block,
616 					chain_length, erase_mark);
617 				/*
618 				 * Assume end of chain, probably incomplete
619 				 * fold/erase...
620 				 */
621 				if (chain_length == 0)
622 					do_format_chain++;
623 				break;
624 			}
625 
626 			/* Check for it being free already then... */
627 			if ((logical_block == BLOCK_FREE) ||
628 			    (logical_block == BLOCK_NIL)) {
629 				s->PUtable[block] = BLOCK_FREE;
630 				break;
631 			}
632 
633 			/* Sanity checks on block numbers */
634 			if ((logical_block >= s->nb_blocks) ||
635 			    ((prev_block >= s->nb_blocks) &&
636 			     (prev_block != BLOCK_NIL))) {
637 				if (chain_length > 0) {
638 					printk(KERN_WARNING "INFTL: corrupt "
639 						"block %d in chain %d?\n",
640 						block, first_block);
641 					do_format_chain++;
642 				}
643 				break;
644 			}
645 
646 			if (first_logical_block == BLOCK_NIL) {
647 				first_logical_block = logical_block;
648 			} else {
649 				if (first_logical_block != logical_block) {
650 					/* Normal for folded chain... */
651 					break;
652 				}
653 			}
654 
655 			/*
656 			 * Current block is valid, so if we followed a virtual
657 			 * chain to get here then we can set the previous
658 			 * block pointer in our PUtable now. Then move onto
659 			 * the previous block in the chain.
660 			 */
661 			s->PUtable[block] = BLOCK_NIL;
662 			if (last_block != BLOCK_NIL)
663 				s->PUtable[last_block] = block;
664 			last_block = block;
665 			block = prev_block;
666 
667 			/* Check for end of chain */
668 			if (block == BLOCK_NIL)
669 				break;
670 
671 			/* Validate next block before following it... */
672 			if (block > s->lastEUN) {
673 				printk(KERN_WARNING "INFTL: invalid previous "
674 					"block %d in chain %d?\n", block,
675 					first_block);
676 				do_format_chain++;
677 				break;
678 			}
679 		}
680 
681 		if (do_format_chain) {
682 			format_chain(s, first_block);
683 			continue;
684 		}
685 
686 		/*
687 		 * Looks like a valid chain then. It may not really be the
688 		 * newest block in the chain, but it is the newest we have
689 		 * found so far. We might update it in later iterations of
690 		 * this loop if we find something newer.
691 		 */
692 		s->VUtable[first_logical_block] = first_block;
693 		logical_block = BLOCK_NIL;
694 	}
695 
696 	INFTL_dumptables(s);
697 
698 	/*
699 	 * Second pass, check for infinite loops in chains. These are
700 	 * possible because we don't update the previous pointers when
701 	 * we fold chains. No big deal, just fix them up in PUtable.
702 	 */
703 	pr_debug("INFTL: pass 2, validate virtual chains\n");
704 	for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
705 		block = s->VUtable[logical_block];
706 		last_block = BLOCK_NIL;
707 
708 		/* Check for free/reserved/nil */
709 		if (block >= BLOCK_RESERVED)
710 			continue;
711 
712 		ANAC = ANACtable[block];
713 		for (i = 0; i < s->numvunits; i++) {
714 			if (s->PUtable[block] == BLOCK_NIL)
715 				break;
716 			if (s->PUtable[block] > s->lastEUN) {
717 				printk(KERN_WARNING "INFTL: invalid prev %d, "
718 					"in virtual chain %d\n",
719 					s->PUtable[block], logical_block);
720 				s->PUtable[block] = BLOCK_NIL;
721 
722 			}
723 			if (ANACtable[block] != ANAC) {
724 				/*
725 				 * Chain must point back to itself. This is ok,
726 				 * but we will need adjust the tables with this
727 				 * newest block and oldest block.
728 				 */
729 				s->VUtable[logical_block] = block;
730 				s->PUtable[last_block] = BLOCK_NIL;
731 				break;
732 			}
733 
734 			ANAC--;
735 			last_block = block;
736 			block = s->PUtable[block];
737 		}
738 
739 		if (i >= s->nb_blocks) {
740 			/*
741 			 * Uhoo, infinite chain with valid ANACS!
742 			 * Format whole chain...
743 			 */
744 			format_chain(s, first_block);
745 		}
746 	}
747 
748 	INFTL_dumptables(s);
749 	INFTL_dumpVUchains(s);
750 
751 	/*
752 	 * Third pass, format unreferenced blocks and init free block count.
753 	 */
754 	s->numfreeEUNs = 0;
755 	s->LastFreeEUN = BLOCK_NIL;
756 
757 	pr_debug("INFTL: pass 3, format unused blocks\n");
758 	for (block = s->firstEUN; block <= s->lastEUN; block++) {
759 		if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
760 			printk("INFTL: unreferenced block %d, formatting it\n",
761 				block);
762 			if (INFTL_formatblock(s, block) < 0)
763 				s->PUtable[block] = BLOCK_RESERVED;
764 			else
765 				s->PUtable[block] = BLOCK_FREE;
766 		}
767 		if (s->PUtable[block] == BLOCK_FREE) {
768 			s->numfreeEUNs++;
769 			if (s->LastFreeEUN == BLOCK_NIL)
770 				s->LastFreeEUN = block;
771 		}
772 	}
773 
774 	kfree(ANACtable);
775 	return 0;
776 }
777