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 */
31static 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, from: block * inftl->EraseSize, SECTORSIZE,
63 retlen: &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(p: buf, q: "BNAND", size: 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 offs: block * inftl->EraseSize + SECTORSIZE + 8,
90 len: 8, retlen: &retlen,buf: (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, from: block * inftl->EraseSize + 4096, SECTORSIZE,
108 retlen: &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(p: mh, q: buf, size: 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(n: inftl->nb_blocks, size: sizeof(u16),
261 GFP_KERNEL);
262 if (!inftl->PUtable)
263 return -ENOMEM;
264
265 inftl->VUtable = kmalloc_array(n: inftl->nb_blocks, size: sizeof(u16),
266 GFP_KERNEL);
267 if (!inftl->VUtable) {
268 kfree(objp: 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(mtd: inftl->mbd.mtd,
289 ofs: 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
302static 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 */
316static 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, from: address, SECTORSIZE, retlen: &retlen, buf))
331 goto out;
332 if (memcmpb(a: buf, c: 0xff, SECTORSIZE) != 0)
333 goto out;
334
335 if (check_oob) {
336 if(inftl_read_oob(mtd, offs: address, len: mtd->oobsize,
337 retlen: &retlen, buf: &buf[SECTORSIZE]) < 0)
338 goto out;
339 if (memcmpb(a: buf + SECTORSIZE, c: 0xff, n: mtd->oobsize) != 0)
340 goto out;
341 }
342 address += SECTORSIZE;
343 }
344
345 ret = 0;
346
347out:
348 kfree(objp: 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 */
361int 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(mtd: 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, address: instr->addr, len: instr->len, check_oob: 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, offs: instr->addr + 8, len: 8, retlen: &retlen, buf: (char *)&uci) < 0)
410 goto fail;
411 return 0;
412fail:
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(mtd: inftl->mbd.mtd, ofs: 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 */
427static 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
455void 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
500void 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
526int 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(inftl: 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(n: s->nb_blocks, size: 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, offs: block * s->EraseSize + 8,
583 len: 8, retlen: &retlen, buf: (char *)&h0) < 0 ||
584 inftl_read_oob(mtd, offs: block * s->EraseSize +
585 2 * SECTORSIZE + 8, len: 8, retlen: &retlen,
586 buf: (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(inftl: 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(inftl: 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(inftl: 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(objp: ANACtable);
775 return 0;
776}
777

source code of linux/drivers/mtd/inftlmount.c