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Linux 2.6.26-rc1
[cris-mirror.git] / drivers / mtd / nftlmount.c
blob345e6eff89ce5929c3548d1874b6363b102ae554
1 /*
2 * NFTL mount code with extensive checks
3 *
4 * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
5 * Copyright (C) 2000 Netgem S.A.
6 *
7 * $Id: nftlmount.c,v 1.41 2005/11/07 11:14:21 gleixner Exp $
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23
24 #include <linux/kernel.h>
25 #include <asm/errno.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/nand.h>
30 #include <linux/mtd/nftl.h>
31
32 #define SECTORSIZE 512
33
34 char nftlmountrev[]="$Revision: 1.41 $";
35
36 /* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the
37 * various device information of the NFTL partition and Bad Unit Table. Update
38 * the ReplUnitTable[] table accroding to the Bad Unit Table. ReplUnitTable[]
39 * is used for management of Erase Unit in other routines in nftl.c and nftlmount.c
40 */
41 static int find_boot_record(struct NFTLrecord *nftl)
42 {
43 struct nftl_uci1 h1;
44 unsigned int block, boot_record_count = 0;
45 size_t retlen;
46 u8 buf[SECTORSIZE];
47 struct NFTLMediaHeader *mh = &nftl->MediaHdr;
48 struct mtd_info *mtd = nftl->mbd.mtd;
49 unsigned int i;
50
51 /* Assume logical EraseSize == physical erasesize for starting the scan.
52 We'll sort it out later if we find a MediaHeader which says otherwise */
53 /* Actually, we won't. The new DiskOnChip driver has already scanned
54 the MediaHeader and adjusted the virtual erasesize it presents in
55 the mtd device accordingly. We could even get rid of
56 nftl->EraseSize if there were any point in doing so. */
57 nftl->EraseSize = nftl->mbd.mtd->erasesize;
58 nftl->nb_blocks = nftl->mbd.mtd->size / nftl->EraseSize;
59
60 nftl->MediaUnit = BLOCK_NIL;
61 nftl->SpareMediaUnit = BLOCK_NIL;
62
63 /* search for a valid boot record */
64 for (block = 0; block < nftl->nb_blocks; block++) {
65 int ret;
66
67 /* Check for ANAND header first. Then can whinge if it's found but later
68 checks fail */
69 ret = mtd->read(mtd, block * nftl->EraseSize, SECTORSIZE,
70 &retlen, buf);
71 /* We ignore ret in case the ECC of the MediaHeader is invalid
72 (which is apparently acceptable) */
73 if (retlen != SECTORSIZE) {
74 static int warncount = 5;
75
76 if (warncount) {
77 printk(KERN_WARNING "Block read at 0x%x of mtd%d failed: %d\n",
78 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
79 if (!--warncount)
80 printk(KERN_WARNING "Further failures for this block will not be printed\n");
81 }
82 continue;
83 }
84
85 if (retlen < 6 || memcmp(buf, "ANAND", 6)) {
86 /* ANAND\0 not found. Continue */
87 #if 0
88 printk(KERN_DEBUG "ANAND header not found at 0x%x in mtd%d\n",
89 block * nftl->EraseSize, nftl->mbd.mtd->index);
90 #endif
91 continue;
92 }
93
94 /* To be safer with BIOS, also use erase mark as discriminant */
95 if ((ret = nftl_read_oob(mtd, block * nftl->EraseSize +
96 SECTORSIZE + 8, 8, &retlen,
97 (char *)&h1) < 0)) {
98 printk(KERN_WARNING "ANAND header found at 0x%x in mtd%d, but OOB data read failed (err %d)\n",
99 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
100 continue;
101 }
102
103 #if 0 /* Some people seem to have devices without ECC or erase marks
104 on the Media Header blocks. There are enough other sanity
105 checks in here that we can probably do without it.
106 */
107 if (le16_to_cpu(h1.EraseMark | h1.EraseMark1) != ERASE_MARK) {
108 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but erase mark not present (0x%04x,0x%04x instead)\n",
109 block * nftl->EraseSize, nftl->mbd.mtd->index,
110 le16_to_cpu(h1.EraseMark), le16_to_cpu(h1.EraseMark1));
111 continue;
112 }
113
114 /* Finally reread to check ECC */
115 if ((ret = mtd->read(mtd, block * nftl->EraseSize, SECTORSIZE,
116 &retlen, buf) < 0)) {
117 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but ECC read failed (err %d)\n",
118 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
119 continue;
120 }
121
122 /* Paranoia. Check the ANAND header is still there after the ECC read */
123 if (memcmp(buf, "ANAND", 6)) {
124 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but went away on reread!\n",
125 block * nftl->EraseSize, nftl->mbd.mtd->index);
126 printk(KERN_NOTICE "New data are: %02x %02x %02x %02x %02x %02x\n",
127 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
128 continue;
129 }
130 #endif
131 /* OK, we like it. */
132
133 if (boot_record_count) {
134 /* We've already processed one. So we just check if
135 this one is the same as the first one we found */
136 if (memcmp(mh, buf, sizeof(struct NFTLMediaHeader))) {
137 printk(KERN_NOTICE "NFTL Media Headers at 0x%x and 0x%x disagree.\n",
138 nftl->MediaUnit * nftl->EraseSize, block * nftl->EraseSize);
139 /* if (debug) Print both side by side */
140 if (boot_record_count < 2) {
141 /* We haven't yet seen two real ones */
142 return -1;
143 }
144 continue;
145 }
146 if (boot_record_count == 1)
147 nftl->SpareMediaUnit = block;
148
149 /* Mark this boot record (NFTL MediaHeader) block as reserved */
150 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
151
152
153 boot_record_count++;
154 continue;
155 }
156
157 /* This is the first we've seen. Copy the media header structure into place */
158 memcpy(mh, buf, sizeof(struct NFTLMediaHeader));
159
160 /* Do some sanity checks on it */
161 #if 0
162 The new DiskOnChip driver scans the MediaHeader itself, and presents a virtual
163 erasesize based on UnitSizeFactor. So the erasesize we read from the mtd
164 device is already correct.
165 if (mh->UnitSizeFactor == 0) {
166 printk(KERN_NOTICE "NFTL: UnitSizeFactor 0x00 detected. This violates the spec but we think we know what it means...\n");
167 } else if (mh->UnitSizeFactor < 0xfc) {
168 printk(KERN_NOTICE "Sorry, we don't support UnitSizeFactor 0x%02x\n",
169 mh->UnitSizeFactor);
170 return -1;
171 } else if (mh->UnitSizeFactor != 0xff) {
172 printk(KERN_NOTICE "WARNING: Support for NFTL with UnitSizeFactor 0x%02x is experimental\n",
173 mh->UnitSizeFactor);
174 nftl->EraseSize = nftl->mbd.mtd->erasesize << (0xff - mh->UnitSizeFactor);
175 nftl->nb_blocks = nftl->mbd.mtd->size / nftl->EraseSize;
176 }
177 #endif
178 nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN);
179 if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) {
180 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n");
181 printk(KERN_NOTICE "nb_boot_blocks (%d) + 2 > nb_blocks (%d)\n",
182 nftl->nb_boot_blocks, nftl->nb_blocks);
183 return -1;
184 }
185
186 nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize;
187 if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) {
188 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n");
189 printk(KERN_NOTICE "numvunits (%d) > nb_blocks (%d) - nb_boot_blocks(%d) - 2\n",
190 nftl->numvunits, nftl->nb_blocks, nftl->nb_boot_blocks);
191 return -1;
192 }
193
194 nftl->mbd.size = nftl->numvunits * (nftl->EraseSize / SECTORSIZE);
195
196 /* If we're not using the last sectors in the device for some reason,
197 reduce nb_blocks accordingly so we forget they're there */
198 nftl->nb_blocks = le16_to_cpu(mh->NumEraseUnits) + le16_to_cpu(mh->FirstPhysicalEUN);
199
200 /* XXX: will be suppressed */
201 nftl->lastEUN = nftl->nb_blocks - 1;
202
203 /* memory alloc */
204 nftl->EUNtable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL);
205 if (!nftl->EUNtable) {
206 printk(KERN_NOTICE "NFTL: allocation of EUNtable failed\n");
207 return -ENOMEM;
208 }
209
210 nftl->ReplUnitTable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL);
211 if (!nftl->ReplUnitTable) {
212 kfree(nftl->EUNtable);
213 printk(KERN_NOTICE "NFTL: allocation of ReplUnitTable failed\n");
214 return -ENOMEM;
215 }
216
217 /* mark the bios blocks (blocks before NFTL MediaHeader) as reserved */
218 for (i = 0; i < nftl->nb_boot_blocks; i++)
219 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
220 /* mark all remaining blocks as potentially containing data */
221 for (; i < nftl->nb_blocks; i++) {
222 nftl->ReplUnitTable[i] = BLOCK_NOTEXPLORED;
223 }
224
225 /* Mark this boot record (NFTL MediaHeader) block as reserved */
226 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
227
228 /* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */
229 for (i = 0; i < nftl->nb_blocks; i++) {
230 #if 0
231 The new DiskOnChip driver already scanned the bad block table. Just query it.
232 if ((i & (SECTORSIZE - 1)) == 0) {
233 /* read one sector for every SECTORSIZE of blocks */
234 if ((ret = mtd->read(nftl->mbd.mtd, block * nftl->EraseSize +
235 i + SECTORSIZE, SECTORSIZE, &retlen,
236 buf)) < 0) {
237 printk(KERN_NOTICE "Read of bad sector table failed (err %d)\n",
238 ret);
239 kfree(nftl->ReplUnitTable);
240 kfree(nftl->EUNtable);
241 return -1;
242 }
243 }
244 /* mark the Bad Erase Unit as RESERVED in ReplUnitTable */
245 if (buf[i & (SECTORSIZE - 1)] != 0xff)
246 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
247 #endif
248 if (nftl->mbd.mtd->block_isbad(nftl->mbd.mtd, i * nftl->EraseSize))
249 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
250 }
251
252 nftl->MediaUnit = block;
253 boot_record_count++;
254
255 } /* foreach (block) */
256
257 return boot_record_count?0:-1;
258 }
259
260 static int memcmpb(void *a, int c, int n)
261 {
262 int i;
263 for (i = 0; i < n; i++) {
264 if (c != ((unsigned char *)a)[i])
265 return 1;
266 }
267 return 0;
268 }
269
270 /* check_free_sector: check if a free sector is actually FREE, i.e. All 0xff in data and oob area */
271 static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int len,
272 int check_oob)
273 {
274 u8 buf[SECTORSIZE + nftl->mbd.mtd->oobsize];
275 struct mtd_info *mtd = nftl->mbd.mtd;
276 size_t retlen;
277 int i;
278
279 for (i = 0; i < len; i += SECTORSIZE) {
280 if (mtd->read(mtd, address, SECTORSIZE, &retlen, buf))
281 return -1;
282 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
283 return -1;
284
285 if (check_oob) {
286 if(nftl_read_oob(mtd, address, mtd->oobsize,
287 &retlen, &buf[SECTORSIZE]) < 0)
288 return -1;
289 if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
290 return -1;
291 }
292 address += SECTORSIZE;
293 }
294
295 return 0;
296 }
297
298 /* NFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase Unit and
299 * Update NFTL metadata. Each erase operation is checked with check_free_sectors
300 *
301 * Return: 0 when succeed, -1 on error.
302 *
303 * ToDo: 1. Is it neceressary to check_free_sector after erasing ??
304 */
305 int NFTL_formatblock(struct NFTLrecord *nftl, int block)
306 {
307 size_t retlen;
308 unsigned int nb_erases, erase_mark;
309 struct nftl_uci1 uci;
310 struct erase_info *instr = &nftl->instr;
311 struct mtd_info *mtd = nftl->mbd.mtd;
312
313 /* Read the Unit Control Information #1 for Wear-Leveling */
314 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8,
315 8, &retlen, (char *)&uci) < 0)
316 goto default_uci1;
317
318 erase_mark = le16_to_cpu ((uci.EraseMark | uci.EraseMark1));
319 if (erase_mark != ERASE_MARK) {
320 default_uci1:
321 uci.EraseMark = cpu_to_le16(ERASE_MARK);
322 uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
323 uci.WearInfo = cpu_to_le32(0);
324 }
325
326 memset(instr, 0, sizeof(struct erase_info));
327
328 /* XXX: use async erase interface, XXX: test return code */
329 instr->mtd = nftl->mbd.mtd;
330 instr->addr = block * nftl->EraseSize;
331 instr->len = nftl->EraseSize;
332 mtd->erase(mtd, instr);
333
334 if (instr->state == MTD_ERASE_FAILED) {
335 printk("Error while formatting block %d\n", block);
336 goto fail;
337 }
338
339 /* increase and write Wear-Leveling info */
340 nb_erases = le32_to_cpu(uci.WearInfo);
341 nb_erases++;
342
343 /* wrap (almost impossible with current flashs) or free block */
344 if (nb_erases == 0)
345 nb_erases = 1;
346
347 /* check the "freeness" of Erase Unit before updating metadata
348 * FixMe: is this check really necessary ? since we have check the
349 * return code after the erase operation. */
350 if (check_free_sectors(nftl, instr->addr, nftl->EraseSize, 1) != 0)
351 goto fail;
352
353 uci.WearInfo = le32_to_cpu(nb_erases);
354 if (nftl_write_oob(mtd, block * nftl->EraseSize + SECTORSIZE +
355 8, 8, &retlen, (char *)&uci) < 0)
356 goto fail;
357 return 0;
358 fail:
359 /* could not format, update the bad block table (caller is responsible
360 for setting the ReplUnitTable to BLOCK_RESERVED on failure) */
361 nftl->mbd.mtd->block_markbad(nftl->mbd.mtd, instr->addr);
362 return -1;
363 }
364
365 /* check_sectors_in_chain: Check that each sector of a Virtual Unit Chain is correct.
366 * Mark as 'IGNORE' each incorrect sector. This check is only done if the chain
367 * was being folded when NFTL was interrupted.
368 *
369 * The check_free_sectors in this function is neceressary. There is a possible
370 * situation that after writing the Data area, the Block Control Information is
371 * not updated according (due to power failure or something) which leaves the block
372 * in an umconsistent state. So we have to check if a block is really FREE in this
373 * case. */
374 static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_block)
375 {
376 struct mtd_info *mtd = nftl->mbd.mtd;
377 unsigned int block, i, status;
378 struct nftl_bci bci;
379 int sectors_per_block;
380 size_t retlen;
381
382 sectors_per_block = nftl->EraseSize / SECTORSIZE;
383 block = first_block;
384 for (;;) {
385 for (i = 0; i < sectors_per_block; i++) {
386 if (nftl_read_oob(mtd,
387 block * nftl->EraseSize + i * SECTORSIZE,
388 8, &retlen, (char *)&bci) < 0)
389 status = SECTOR_IGNORE;
390 else
391 status = bci.Status | bci.Status1;
392
393 switch(status) {
394 case SECTOR_FREE:
395 /* verify that the sector is really free. If not, mark
396 as ignore */
397 if (memcmpb(&bci, 0xff, 8) != 0 ||
398 check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE,
399 SECTORSIZE, 0) != 0) {
400 printk("Incorrect free sector %d in block %d: "
401 "marking it as ignored\n",
402 i, block);
403
404 /* sector not free actually : mark it as SECTOR_IGNORE */
405 bci.Status = SECTOR_IGNORE;
406 bci.Status1 = SECTOR_IGNORE;
407 nftl_write_oob(mtd, block *
408 nftl->EraseSize +
409 i * SECTORSIZE, 8,
410 &retlen, (char *)&bci);
411 }
412 break;
413 default:
414 break;
415 }
416 }
417
418 /* proceed to next Erase Unit on the chain */
419 block = nftl->ReplUnitTable[block];
420 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
421 printk("incorrect ReplUnitTable[] : %d\n", block);
422 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
423 break;
424 }
425 }
426
427 /* calc_chain_length: Walk through a Virtual Unit Chain and estimate chain length */
428 static int calc_chain_length(struct NFTLrecord *nftl, unsigned int first_block)
429 {
430 unsigned int length = 0, block = first_block;
431
432 for (;;) {
433 length++;
434 /* avoid infinite loops, although this is guaranted not to
435 happen because of the previous checks */
436 if (length >= nftl->nb_blocks) {
437 printk("nftl: length too long %d !\n", length);
438 break;
439 }
440
441 block = nftl->ReplUnitTable[block];
442 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
443 printk("incorrect ReplUnitTable[] : %d\n", block);
444 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
445 break;
446 }
447 return length;
448 }
449
450 /* format_chain: Format an invalid Virtual Unit chain. It frees all the Erase Units in a
451 * Virtual Unit Chain, i.e. all the units are disconnected.
452 *
453 * It is not stricly correct to begin from the first block of the chain because
454 * if we stop the code, we may see again a valid chain if there was a first_block
455 * flag in a block inside it. But is it really a problem ?
456 *
457 * FixMe: Figure out what the last statesment means. What if power failure when we are
458 * in the for (;;) loop formatting blocks ??
459 */
460 static void format_chain(struct NFTLrecord *nftl, unsigned int first_block)
461 {
462 unsigned int block = first_block, block1;
463
464 printk("Formatting chain at block %d\n", first_block);
465
466 for (;;) {
467 block1 = nftl->ReplUnitTable[block];
468
469 printk("Formatting block %d\n", block);
470 if (NFTL_formatblock(nftl, block) < 0) {
471 /* cannot format !!!! Mark it as Bad Unit */
472 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
473 } else {
474 nftl->ReplUnitTable[block] = BLOCK_FREE;
475 }
476
477 /* goto next block on the chain */
478 block = block1;
479
480 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
481 printk("incorrect ReplUnitTable[] : %d\n", block);
482 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
483 break;
484 }
485 }
486
487 /* check_and_mark_free_block: Verify that a block is free in the NFTL sense (valid erase mark) or
488 * totally free (only 0xff).
489 *
490 * Definition: Free Erase Unit -- A properly erased/formatted Free Erase Unit should have meet the
491 * following critia:
492 * 1. */
493 static int check_and_mark_free_block(struct NFTLrecord *nftl, int block)
494 {
495 struct mtd_info *mtd = nftl->mbd.mtd;
496 struct nftl_uci1 h1;
497 unsigned int erase_mark;
498 size_t retlen;
499
500 /* check erase mark. */
501 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8,
502 &retlen, (char *)&h1) < 0)
503 return -1;
504
505 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1));
506 if (erase_mark != ERASE_MARK) {
507 /* if no erase mark, the block must be totally free. This is
508 possible in two cases : empty filsystem or interrupted erase (very unlikely) */
509 if (check_free_sectors (nftl, block * nftl->EraseSize, nftl->EraseSize, 1) != 0)
510 return -1;
511
512 /* free block : write erase mark */
513 h1.EraseMark = cpu_to_le16(ERASE_MARK);
514 h1.EraseMark1 = cpu_to_le16(ERASE_MARK);
515 h1.WearInfo = cpu_to_le32(0);
516 if (nftl_write_oob(mtd,
517 block * nftl->EraseSize + SECTORSIZE + 8, 8,
518 &retlen, (char *)&h1) < 0)
519 return -1;
520 } else {
521 #if 0
522 /* if erase mark present, need to skip it when doing check */
523 for (i = 0; i < nftl->EraseSize; i += SECTORSIZE) {
524 /* check free sector */
525 if (check_free_sectors (nftl, block * nftl->EraseSize + i,
526 SECTORSIZE, 0) != 0)
527 return -1;
528
529 if (nftl_read_oob(mtd, block * nftl->EraseSize + i,
530 16, &retlen, buf) < 0)
531 return -1;
532 if (i == SECTORSIZE) {
533 /* skip erase mark */
534 if (memcmpb(buf, 0xff, 8))
535 return -1;
536 } else {
537 if (memcmpb(buf, 0xff, 16))
538 return -1;
539 }
540 }
541 #endif
542 }
543
544 return 0;
545 }
546
547 /* get_fold_mark: Read fold mark from Unit Control Information #2, we use FOLD_MARK_IN_PROGRESS
548 * to indicate that we are in the progression of a Virtual Unit Chain folding. If the UCI #2
549 * is FOLD_MARK_IN_PROGRESS when mounting the NFTL, the (previous) folding process is interrupted
550 * for some reason. A clean up/check of the VUC is neceressary in this case.
551 *
552 * WARNING: return 0 if read error
553 */
554 static int get_fold_mark(struct NFTLrecord *nftl, unsigned int block)
555 {
556 struct mtd_info *mtd = nftl->mbd.mtd;
557 struct nftl_uci2 uci;
558 size_t retlen;
559
560 if (nftl_read_oob(mtd, block * nftl->EraseSize + 2 * SECTORSIZE + 8,
561 8, &retlen, (char *)&uci) < 0)
562 return 0;
563
564 return le16_to_cpu((uci.FoldMark | uci.FoldMark1));
565 }
566
567 int NFTL_mount(struct NFTLrecord *s)
568 {
569 int i;
570 unsigned int first_logical_block, logical_block, rep_block, nb_erases, erase_mark;
571 unsigned int block, first_block, is_first_block;
572 int chain_length, do_format_chain;
573 struct nftl_uci0 h0;
574 struct nftl_uci1 h1;
575 struct mtd_info *mtd = s->mbd.mtd;
576 size_t retlen;
577
578 /* search for NFTL MediaHeader and Spare NFTL Media Header */
579 if (find_boot_record(s) < 0) {
580 printk("Could not find valid boot record\n");
581 return -1;
582 }
583
584 /* init the logical to physical table */
585 for (i = 0; i < s->nb_blocks; i++) {
586 s->EUNtable[i] = BLOCK_NIL;
587 }
588
589 /* first pass : explore each block chain */
590 first_logical_block = 0;
591 for (first_block = 0; first_block < s->nb_blocks; first_block++) {
592 /* if the block was not already explored, we can look at it */
593 if (s->ReplUnitTable[first_block] == BLOCK_NOTEXPLORED) {
594 block = first_block;
595 chain_length = 0;
596 do_format_chain = 0;
597
598 for (;;) {
599 /* read the block header. If error, we format the chain */
600 if (nftl_read_oob(mtd,
601 block * s->EraseSize + 8, 8,
602 &retlen, (char *)&h0) < 0 ||
603 nftl_read_oob(mtd,
604 block * s->EraseSize +
605 SECTORSIZE + 8, 8,
606 &retlen, (char *)&h1) < 0) {
607 s->ReplUnitTable[block] = BLOCK_NIL;
608 do_format_chain = 1;
609 break;
610 }
611
612 logical_block = le16_to_cpu ((h0.VirtUnitNum | h0.SpareVirtUnitNum));
613 rep_block = le16_to_cpu ((h0.ReplUnitNum | h0.SpareReplUnitNum));
614 nb_erases = le32_to_cpu (h1.WearInfo);
615 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1));
616
617 is_first_block = !(logical_block >> 15);
618 logical_block = logical_block & 0x7fff;
619
620 /* invalid/free block test */
621 if (erase_mark != ERASE_MARK || logical_block >= s->nb_blocks) {
622 if (chain_length == 0) {
623 /* if not currently in a chain, we can handle it safely */
624 if (check_and_mark_free_block(s, block) < 0) {
625 /* not really free: format it */
626 printk("Formatting block %d\n", block);
627 if (NFTL_formatblock(s, block) < 0) {
628 /* could not format: reserve the block */
629 s->ReplUnitTable[block] = BLOCK_RESERVED;
630 } else {
631 s->ReplUnitTable[block] = BLOCK_FREE;
632 }
633 } else {
634 /* free block: mark it */
635 s->ReplUnitTable[block] = BLOCK_FREE;
636 }
637 /* directly examine the next block. */
638 goto examine_ReplUnitTable;
639 } else {
640 /* the block was in a chain : this is bad. We
641 must format all the chain */
642 printk("Block %d: free but referenced in chain %d\n",
643 block, first_block);
644 s->ReplUnitTable[block] = BLOCK_NIL;
645 do_format_chain = 1;
646 break;
647 }
648 }
649
650 /* we accept only first blocks here */
651 if (chain_length == 0) {
652 /* this block is not the first block in chain :
653 ignore it, it will be included in a chain
654 later, or marked as not explored */
655 if (!is_first_block)
656 goto examine_ReplUnitTable;
657 first_logical_block = logical_block;
658 } else {
659 if (logical_block != first_logical_block) {
660 printk("Block %d: incorrect logical block: %d expected: %d\n",
661 block, logical_block, first_logical_block);
662 /* the chain is incorrect : we must format it,
663 but we need to read it completly */
664 do_format_chain = 1;
665 }
666 if (is_first_block) {
667 /* we accept that a block is marked as first
668 block while being last block in a chain
669 only if the chain is being folded */
670 if (get_fold_mark(s, block) != FOLD_MARK_IN_PROGRESS ||
671 rep_block != 0xffff) {
672 printk("Block %d: incorrectly marked as first block in chain\n",
673 block);
674 /* the chain is incorrect : we must format it,
675 but we need to read it completly */
676 do_format_chain = 1;
677 } else {
678 printk("Block %d: folding in progress - ignoring first block flag\n",
679 block);
680 }
681 }
682 }
683 chain_length++;
684 if (rep_block == 0xffff) {
685 /* no more blocks after */
686 s->ReplUnitTable[block] = BLOCK_NIL;
687 break;
688 } else if (rep_block >= s->nb_blocks) {
689 printk("Block %d: referencing invalid block %d\n",
690 block, rep_block);
691 do_format_chain = 1;
692 s->ReplUnitTable[block] = BLOCK_NIL;
693 break;
694 } else if (s->ReplUnitTable[rep_block] != BLOCK_NOTEXPLORED) {
695 /* same problem as previous 'is_first_block' test:
696 we accept that the last block of a chain has
697 the first_block flag set if folding is in
698 progress. We handle here the case where the
699 last block appeared first */
700 if (s->ReplUnitTable[rep_block] == BLOCK_NIL &&
701 s->EUNtable[first_logical_block] == rep_block &&
702 get_fold_mark(s, first_block) == FOLD_MARK_IN_PROGRESS) {
703 /* EUNtable[] will be set after */
704 printk("Block %d: folding in progress - ignoring first block flag\n",
705 rep_block);
706 s->ReplUnitTable[block] = rep_block;
707 s->EUNtable[first_logical_block] = BLOCK_NIL;
708 } else {
709 printk("Block %d: referencing block %d already in another chain\n",
710 block, rep_block);
711 /* XXX: should handle correctly fold in progress chains */
712 do_format_chain = 1;
713 s->ReplUnitTable[block] = BLOCK_NIL;
714 }
715 break;
716 } else {
717 /* this is OK */
718 s->ReplUnitTable[block] = rep_block;
719 block = rep_block;
720 }
721 }
722
723 /* the chain was completely explored. Now we can decide
724 what to do with it */
725 if (do_format_chain) {
726 /* invalid chain : format it */
727 format_chain(s, first_block);
728 } else {
729 unsigned int first_block1, chain_to_format, chain_length1;
730 int fold_mark;
731
732 /* valid chain : get foldmark */
733 fold_mark = get_fold_mark(s, first_block);
734 if (fold_mark == 0) {
735 /* cannot get foldmark : format the chain */
736 printk("Could read foldmark at block %d\n", first_block);
737 format_chain(s, first_block);
738 } else {
739 if (fold_mark == FOLD_MARK_IN_PROGRESS)
740 check_sectors_in_chain(s, first_block);
741
742 /* now handle the case where we find two chains at the
743 same virtual address : we select the longer one,
744 because the shorter one is the one which was being
745 folded if the folding was not done in place */
746 first_block1 = s->EUNtable[first_logical_block];
747 if (first_block1 != BLOCK_NIL) {
748 /* XXX: what to do if same length ? */
749 chain_length1 = calc_chain_length(s, first_block1);
750 printk("Two chains at blocks %d (len=%d) and %d (len=%d)\n",
751 first_block1, chain_length1, first_block, chain_length);
752
753 if (chain_length >= chain_length1) {
754 chain_to_format = first_block1;
755 s->EUNtable[first_logical_block] = first_block;
756 } else {
757 chain_to_format = first_block;
758 }
759 format_chain(s, chain_to_format);
760 } else {
761 s->EUNtable[first_logical_block] = first_block;
762 }
763 }
764 }
765 }
766 examine_ReplUnitTable:;
767 }
768
769 /* second pass to format unreferenced blocks and init free block count */
770 s->numfreeEUNs = 0;
771 s->LastFreeEUN = le16_to_cpu(s->MediaHdr.FirstPhysicalEUN);
772
773 for (block = 0; block < s->nb_blocks; block++) {
774 if (s->ReplUnitTable[block] == BLOCK_NOTEXPLORED) {
775 printk("Unreferenced block %d, formatting it\n", block);
776 if (NFTL_formatblock(s, block) < 0)
777 s->ReplUnitTable[block] = BLOCK_RESERVED;
778 else
779 s->ReplUnitTable[block] = BLOCK_FREE;
780 }
781 if (s->ReplUnitTable[block] == BLOCK_FREE) {
782 s->numfreeEUNs++;
783 s->LastFreeEUN = block;
784 }
785 }
786
787 return 0;
788 }
CRIS linux kernel tree