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Use dentry_path() to create full path to inode object
[pohmelfs.git] / drivers / mtd / nftlmount.c
blob51b9d6af307f616193ebc006b492a5fecedd535b
1 /*
2 * NFTL mount code with extensive checks
3 *
4 * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
5 * Copyright © 2000 Netgem S.A.
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include <linux/kernel.h>
24 #include <asm/errno.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
27 #include <linux/mtd/mtd.h>
28 #include <linux/mtd/nand.h>
29 #include <linux/mtd/nftl.h>
30
31 #define SECTORSIZE 512
32
33 /* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the
34 * various device information of the NFTL partition and Bad Unit Table. Update
35 * the ReplUnitTable[] table according to the Bad Unit Table. ReplUnitTable[]
36 * is used for management of Erase Unit in other routines in nftl.c and nftlmount.c
37 */
38 static int find_boot_record(struct NFTLrecord *nftl)
39 {
40 struct nftl_uci1 h1;
41 unsigned int block, boot_record_count = 0;
42 size_t retlen;
43 u8 buf[SECTORSIZE];
44 struct NFTLMediaHeader *mh = &nftl->MediaHdr;
45 struct mtd_info *mtd = nftl->mbd.mtd;
46 unsigned int i;
47
48 /* Assume logical EraseSize == physical erasesize for starting the scan.
49 We'll sort it out later if we find a MediaHeader which says otherwise */
50 /* Actually, we won't. The new DiskOnChip driver has already scanned
51 the MediaHeader and adjusted the virtual erasesize it presents in
52 the mtd device accordingly. We could even get rid of
53 nftl->EraseSize if there were any point in doing so. */
54 nftl->EraseSize = nftl->mbd.mtd->erasesize;
55 nftl->nb_blocks = (u32)nftl->mbd.mtd->size / nftl->EraseSize;
56
57 nftl->MediaUnit = BLOCK_NIL;
58 nftl->SpareMediaUnit = BLOCK_NIL;
59
60 /* search for a valid boot record */
61 for (block = 0; block < nftl->nb_blocks; block++) {
62 int ret;
63
64 /* Check for ANAND header first. Then can whinge if it's found but later
65 checks fail */
66 ret = mtd_read(mtd, block * nftl->EraseSize, SECTORSIZE,
67 &retlen, buf);
68 /* We ignore ret in case the ECC of the MediaHeader is invalid
69 (which is apparently acceptable) */
70 if (retlen != SECTORSIZE) {
71 static int warncount = 5;
72
73 if (warncount) {
74 printk(KERN_WARNING "Block read at 0x%x of mtd%d failed: %d\n",
75 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
76 if (!--warncount)
77 printk(KERN_WARNING "Further failures for this block will not be printed\n");
78 }
79 continue;
80 }
81
82 if (retlen < 6 || memcmp(buf, "ANAND", 6)) {
83 /* ANAND\0 not found. Continue */
84 #if 0
85 printk(KERN_DEBUG "ANAND header not found at 0x%x in mtd%d\n",
86 block * nftl->EraseSize, nftl->mbd.mtd->index);
87 #endif
88 continue;
89 }
90
91 /* To be safer with BIOS, also use erase mark as discriminant */
92 if ((ret = nftl_read_oob(mtd, block * nftl->EraseSize +
93 SECTORSIZE + 8, 8, &retlen,
94 (char *)&h1) < 0)) {
95 printk(KERN_WARNING "ANAND header found at 0x%x in mtd%d, but OOB data read failed (err %d)\n",
96 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
97 continue;
98 }
99
100 #if 0 /* Some people seem to have devices without ECC or erase marks
101 on the Media Header blocks. There are enough other sanity
102 checks in here that we can probably do without it.
103 */
104 if (le16_to_cpu(h1.EraseMark | h1.EraseMark1) != ERASE_MARK) {
105 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but erase mark not present (0x%04x,0x%04x instead)\n",
106 block * nftl->EraseSize, nftl->mbd.mtd->index,
107 le16_to_cpu(h1.EraseMark), le16_to_cpu(h1.EraseMark1));
108 continue;
109 }
110
111 /* Finally reread to check ECC */
112 if ((ret = mtd->read(mtd, block * nftl->EraseSize, SECTORSIZE,
113 &retlen, buf) < 0)) {
114 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but ECC read failed (err %d)\n",
115 block * nftl->EraseSize, nftl->mbd.mtd->index, ret);
116 continue;
117 }
118
119 /* Paranoia. Check the ANAND header is still there after the ECC read */
120 if (memcmp(buf, "ANAND", 6)) {
121 printk(KERN_NOTICE "ANAND header found at 0x%x in mtd%d, but went away on reread!\n",
122 block * nftl->EraseSize, nftl->mbd.mtd->index);
123 printk(KERN_NOTICE "New data are: %02x %02x %02x %02x %02x %02x\n",
124 buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
125 continue;
126 }
127 #endif
128 /* OK, we like it. */
129
130 if (boot_record_count) {
131 /* We've already processed one. So we just check if
132 this one is the same as the first one we found */
133 if (memcmp(mh, buf, sizeof(struct NFTLMediaHeader))) {
134 printk(KERN_NOTICE "NFTL Media Headers at 0x%x and 0x%x disagree.\n",
135 nftl->MediaUnit * nftl->EraseSize, block * nftl->EraseSize);
136 /* if (debug) Print both side by side */
137 if (boot_record_count < 2) {
138 /* We haven't yet seen two real ones */
139 return -1;
140 }
141 continue;
142 }
143 if (boot_record_count == 1)
144 nftl->SpareMediaUnit = block;
145
146 /* Mark this boot record (NFTL MediaHeader) block as reserved */
147 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
148
149
150 boot_record_count++;
151 continue;
152 }
153
154 /* This is the first we've seen. Copy the media header structure into place */
155 memcpy(mh, buf, sizeof(struct NFTLMediaHeader));
156
157 /* Do some sanity checks on it */
158 #if 0
159 The new DiskOnChip driver scans the MediaHeader itself, and presents a virtual
160 erasesize based on UnitSizeFactor. So the erasesize we read from the mtd
161 device is already correct.
162 if (mh->UnitSizeFactor == 0) {
163 printk(KERN_NOTICE "NFTL: UnitSizeFactor 0x00 detected. This violates the spec but we think we know what it means...\n");
164 } else if (mh->UnitSizeFactor < 0xfc) {
165 printk(KERN_NOTICE "Sorry, we don't support UnitSizeFactor 0x%02x\n",
166 mh->UnitSizeFactor);
167 return -1;
168 } else if (mh->UnitSizeFactor != 0xff) {
169 printk(KERN_NOTICE "WARNING: Support for NFTL with UnitSizeFactor 0x%02x is experimental\n",
170 mh->UnitSizeFactor);
171 nftl->EraseSize = nftl->mbd.mtd->erasesize << (0xff - mh->UnitSizeFactor);
172 nftl->nb_blocks = (u32)nftl->mbd.mtd->size / nftl->EraseSize;
173 }
174 #endif
175 nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN);
176 if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) {
177 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n");
178 printk(KERN_NOTICE "nb_boot_blocks (%d) + 2 > nb_blocks (%d)\n",
179 nftl->nb_boot_blocks, nftl->nb_blocks);
180 return -1;
181 }
182
183 nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize;
184 if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) {
185 printk(KERN_NOTICE "NFTL Media Header sanity check failed:\n");
186 printk(KERN_NOTICE "numvunits (%d) > nb_blocks (%d) - nb_boot_blocks(%d) - 2\n",
187 nftl->numvunits, nftl->nb_blocks, nftl->nb_boot_blocks);
188 return -1;
189 }
190
191 nftl->mbd.size = nftl->numvunits * (nftl->EraseSize / SECTORSIZE);
192
193 /* If we're not using the last sectors in the device for some reason,
194 reduce nb_blocks accordingly so we forget they're there */
195 nftl->nb_blocks = le16_to_cpu(mh->NumEraseUnits) + le16_to_cpu(mh->FirstPhysicalEUN);
196
197 /* XXX: will be suppressed */
198 nftl->lastEUN = nftl->nb_blocks - 1;
199
200 /* memory alloc */
201 nftl->EUNtable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL);
202 if (!nftl->EUNtable) {
203 printk(KERN_NOTICE "NFTL: allocation of EUNtable failed\n");
204 return -ENOMEM;
205 }
206
207 nftl->ReplUnitTable = kmalloc(nftl->nb_blocks * sizeof(u16), GFP_KERNEL);
208 if (!nftl->ReplUnitTable) {
209 kfree(nftl->EUNtable);
210 printk(KERN_NOTICE "NFTL: allocation of ReplUnitTable failed\n");
211 return -ENOMEM;
212 }
213
214 /* mark the bios blocks (blocks before NFTL MediaHeader) as reserved */
215 for (i = 0; i < nftl->nb_boot_blocks; i++)
216 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
217 /* mark all remaining blocks as potentially containing data */
218 for (; i < nftl->nb_blocks; i++) {
219 nftl->ReplUnitTable[i] = BLOCK_NOTEXPLORED;
220 }
221
222 /* Mark this boot record (NFTL MediaHeader) block as reserved */
223 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
224
225 /* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */
226 for (i = 0; i < nftl->nb_blocks; i++) {
227 #if 0
228 The new DiskOnChip driver already scanned the bad block table. Just query it.
229 if ((i & (SECTORSIZE - 1)) == 0) {
230 /* read one sector for every SECTORSIZE of blocks */
231 if ((ret = mtd->read(nftl->mbd.mtd, block * nftl->EraseSize +
232 i + SECTORSIZE, SECTORSIZE, &retlen,
233 buf)) < 0) {
234 printk(KERN_NOTICE "Read of bad sector table failed (err %d)\n",
235 ret);
236 kfree(nftl->ReplUnitTable);
237 kfree(nftl->EUNtable);
238 return -1;
239 }
240 }
241 /* mark the Bad Erase Unit as RESERVED in ReplUnitTable */
242 if (buf[i & (SECTORSIZE - 1)] != 0xff)
243 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
244 #endif
245 if (mtd_block_isbad(nftl->mbd.mtd,
246 i * nftl->EraseSize))
247 nftl->ReplUnitTable[i] = BLOCK_RESERVED;
248 }
249
250 nftl->MediaUnit = block;
251 boot_record_count++;
252
253 } /* foreach (block) */
254
255 return boot_record_count?0:-1;
256 }
257
258 static int memcmpb(void *a, int c, int n)
259 {
260 int i;
261 for (i = 0; i < n; i++) {
262 if (c != ((unsigned char *)a)[i])
263 return 1;
264 }
265 return 0;
266 }
267
268 /* check_free_sector: check if a free sector is actually FREE, i.e. All 0xff in data and oob area */
269 static int check_free_sectors(struct NFTLrecord *nftl, unsigned int address, int len,
270 int check_oob)
271 {
272 u8 buf[SECTORSIZE + nftl->mbd.mtd->oobsize];
273 struct mtd_info *mtd = nftl->mbd.mtd;
274 size_t retlen;
275 int i;
276
277 for (i = 0; i < len; i += SECTORSIZE) {
278 if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
279 return -1;
280 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
281 return -1;
282
283 if (check_oob) {
284 if(nftl_read_oob(mtd, address, mtd->oobsize,
285 &retlen, &buf[SECTORSIZE]) < 0)
286 return -1;
287 if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
288 return -1;
289 }
290 address += SECTORSIZE;
291 }
292
293 return 0;
294 }
295
296 /* NFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase Unit and
297 * Update NFTL metadata. Each erase operation is checked with check_free_sectors
298 *
299 * Return: 0 when succeed, -1 on error.
300 *
301 * ToDo: 1. Is it necessary to check_free_sector after erasing ??
302 */
303 int NFTL_formatblock(struct NFTLrecord *nftl, int block)
304 {
305 size_t retlen;
306 unsigned int nb_erases, erase_mark;
307 struct nftl_uci1 uci;
308 struct erase_info *instr = &nftl->instr;
309 struct mtd_info *mtd = nftl->mbd.mtd;
310
311 /* Read the Unit Control Information #1 for Wear-Leveling */
312 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8,
313 8, &retlen, (char *)&uci) < 0)
314 goto default_uci1;
315
316 erase_mark = le16_to_cpu ((uci.EraseMark | uci.EraseMark1));
317 if (erase_mark != ERASE_MARK) {
318 default_uci1:
319 uci.EraseMark = cpu_to_le16(ERASE_MARK);
320 uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
321 uci.WearInfo = cpu_to_le32(0);
322 }
323
324 memset(instr, 0, sizeof(struct erase_info));
325
326 /* XXX: use async erase interface, XXX: test return code */
327 instr->mtd = nftl->mbd.mtd;
328 instr->addr = block * nftl->EraseSize;
329 instr->len = nftl->EraseSize;
330 mtd_erase(mtd, instr);
331
332 if (instr->state == MTD_ERASE_FAILED) {
333 printk("Error while formatting block %d\n", block);
334 goto fail;
335 }
336
337 /* increase and write Wear-Leveling info */
338 nb_erases = le32_to_cpu(uci.WearInfo);
339 nb_erases++;
340
341 /* wrap (almost impossible with current flash) or free block */
342 if (nb_erases == 0)
343 nb_erases = 1;
344
345 /* check the "freeness" of Erase Unit before updating metadata
346 * FixMe: is this check really necessary ? since we have check the
347 * return code after the erase operation. */
348 if (check_free_sectors(nftl, instr->addr, nftl->EraseSize, 1) != 0)
349 goto fail;
350
351 uci.WearInfo = le32_to_cpu(nb_erases);
352 if (nftl_write_oob(mtd, block * nftl->EraseSize + SECTORSIZE +
353 8, 8, &retlen, (char *)&uci) < 0)
354 goto fail;
355 return 0;
356 fail:
357 /* could not format, update the bad block table (caller is responsible
358 for setting the ReplUnitTable to BLOCK_RESERVED on failure) */
359 mtd_block_markbad(nftl->mbd.mtd, instr->addr);
360 return -1;
361 }
362
363 /* check_sectors_in_chain: Check that each sector of a Virtual Unit Chain is correct.
364 * Mark as 'IGNORE' each incorrect sector. This check is only done if the chain
365 * was being folded when NFTL was interrupted.
366 *
367 * The check_free_sectors in this function is necessary. There is a possible
368 * situation that after writing the Data area, the Block Control Information is
369 * not updated according (due to power failure or something) which leaves the block
370 * in an inconsistent state. So we have to check if a block is really FREE in this
371 * case. */
372 static void check_sectors_in_chain(struct NFTLrecord *nftl, unsigned int first_block)
373 {
374 struct mtd_info *mtd = nftl->mbd.mtd;
375 unsigned int block, i, status;
376 struct nftl_bci bci;
377 int sectors_per_block;
378 size_t retlen;
379
380 sectors_per_block = nftl->EraseSize / SECTORSIZE;
381 block = first_block;
382 for (;;) {
383 for (i = 0; i < sectors_per_block; i++) {
384 if (nftl_read_oob(mtd,
385 block * nftl->EraseSize + i * SECTORSIZE,
386 8, &retlen, (char *)&bci) < 0)
387 status = SECTOR_IGNORE;
388 else
389 status = bci.Status | bci.Status1;
390
391 switch(status) {
392 case SECTOR_FREE:
393 /* verify that the sector is really free. If not, mark
394 as ignore */
395 if (memcmpb(&bci, 0xff, 8) != 0 ||
396 check_free_sectors(nftl, block * nftl->EraseSize + i * SECTORSIZE,
397 SECTORSIZE, 0) != 0) {
398 printk("Incorrect free sector %d in block %d: "
399 "marking it as ignored\n",
400 i, block);
401
402 /* sector not free actually : mark it as SECTOR_IGNORE */
403 bci.Status = SECTOR_IGNORE;
404 bci.Status1 = SECTOR_IGNORE;
405 nftl_write_oob(mtd, block *
406 nftl->EraseSize +
407 i * SECTORSIZE, 8,
408 &retlen, (char *)&bci);
409 }
410 break;
411 default:
412 break;
413 }
414 }
415
416 /* proceed to next Erase Unit on the chain */
417 block = nftl->ReplUnitTable[block];
418 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
419 printk("incorrect ReplUnitTable[] : %d\n", block);
420 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
421 break;
422 }
423 }
424
425 /* calc_chain_length: Walk through a Virtual Unit Chain and estimate chain length */
426 static int calc_chain_length(struct NFTLrecord *nftl, unsigned int first_block)
427 {
428 unsigned int length = 0, block = first_block;
429
430 for (;;) {
431 length++;
432 /* avoid infinite loops, although this is guaranteed not to
433 happen because of the previous checks */
434 if (length >= nftl->nb_blocks) {
435 printk("nftl: length too long %d !\n", length);
436 break;
437 }
438
439 block = nftl->ReplUnitTable[block];
440 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
441 printk("incorrect ReplUnitTable[] : %d\n", block);
442 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
443 break;
444 }
445 return length;
446 }
447
448 /* format_chain: Format an invalid Virtual Unit chain. It frees all the Erase Units in a
449 * Virtual Unit Chain, i.e. all the units are disconnected.
450 *
451 * It is not strictly correct to begin from the first block of the chain because
452 * if we stop the code, we may see again a valid chain if there was a first_block
453 * flag in a block inside it. But is it really a problem ?
454 *
455 * FixMe: Figure out what the last statement means. What if power failure when we are
456 * in the for (;;) loop formatting blocks ??
457 */
458 static void format_chain(struct NFTLrecord *nftl, unsigned int first_block)
459 {
460 unsigned int block = first_block, block1;
461
462 printk("Formatting chain at block %d\n", first_block);
463
464 for (;;) {
465 block1 = nftl->ReplUnitTable[block];
466
467 printk("Formatting block %d\n", block);
468 if (NFTL_formatblock(nftl, block) < 0) {
469 /* cannot format !!!! Mark it as Bad Unit */
470 nftl->ReplUnitTable[block] = BLOCK_RESERVED;
471 } else {
472 nftl->ReplUnitTable[block] = BLOCK_FREE;
473 }
474
475 /* goto next block on the chain */
476 block = block1;
477
478 if (!(block == BLOCK_NIL || block < nftl->nb_blocks))
479 printk("incorrect ReplUnitTable[] : %d\n", block);
480 if (block == BLOCK_NIL || block >= nftl->nb_blocks)
481 break;
482 }
483 }
484
485 /* check_and_mark_free_block: Verify that a block is free in the NFTL sense (valid erase mark) or
486 * totally free (only 0xff).
487 *
488 * Definition: Free Erase Unit -- A properly erased/formatted Free Erase Unit should have meet the
489 * following criteria:
490 * 1. */
491 static int check_and_mark_free_block(struct NFTLrecord *nftl, int block)
492 {
493 struct mtd_info *mtd = nftl->mbd.mtd;
494 struct nftl_uci1 h1;
495 unsigned int erase_mark;
496 size_t retlen;
497
498 /* check erase mark. */
499 if (nftl_read_oob(mtd, block * nftl->EraseSize + SECTORSIZE + 8, 8,
500 &retlen, (char *)&h1) < 0)
501 return -1;
502
503 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1));
504 if (erase_mark != ERASE_MARK) {
505 /* if no erase mark, the block must be totally free. This is
506 possible in two cases : empty filesystem or interrupted erase (very unlikely) */
507 if (check_free_sectors (nftl, block * nftl->EraseSize, nftl->EraseSize, 1) != 0)
508 return -1;
509
510 /* free block : write erase mark */
511 h1.EraseMark = cpu_to_le16(ERASE_MARK);
512 h1.EraseMark1 = cpu_to_le16(ERASE_MARK);
513 h1.WearInfo = cpu_to_le32(0);
514 if (nftl_write_oob(mtd,
515 block * nftl->EraseSize + SECTORSIZE + 8, 8,
516 &retlen, (char *)&h1) < 0)
517 return -1;
518 } else {
519 #if 0
520 /* if erase mark present, need to skip it when doing check */
521 for (i = 0; i < nftl->EraseSize; i += SECTORSIZE) {
522 /* check free sector */
523 if (check_free_sectors (nftl, block * nftl->EraseSize + i,
524 SECTORSIZE, 0) != 0)
525 return -1;
526
527 if (nftl_read_oob(mtd, block * nftl->EraseSize + i,
528 16, &retlen, buf) < 0)
529 return -1;
530 if (i == SECTORSIZE) {
531 /* skip erase mark */
532 if (memcmpb(buf, 0xff, 8))
533 return -1;
534 } else {
535 if (memcmpb(buf, 0xff, 16))
536 return -1;
537 }
538 }
539 #endif
540 }
541
542 return 0;
543 }
544
545 /* get_fold_mark: Read fold mark from Unit Control Information #2, we use FOLD_MARK_IN_PROGRESS
546 * to indicate that we are in the progression of a Virtual Unit Chain folding. If the UCI #2
547 * is FOLD_MARK_IN_PROGRESS when mounting the NFTL, the (previous) folding process is interrupted
548 * for some reason. A clean up/check of the VUC is necessary in this case.
549 *
550 * WARNING: return 0 if read error
551 */
552 static int get_fold_mark(struct NFTLrecord *nftl, unsigned int block)
553 {
554 struct mtd_info *mtd = nftl->mbd.mtd;
555 struct nftl_uci2 uci;
556 size_t retlen;
557
558 if (nftl_read_oob(mtd, block * nftl->EraseSize + 2 * SECTORSIZE + 8,
559 8, &retlen, (char *)&uci) < 0)
560 return 0;
561
562 return le16_to_cpu((uci.FoldMark | uci.FoldMark1));
563 }
564
565 int NFTL_mount(struct NFTLrecord *s)
566 {
567 int i;
568 unsigned int first_logical_block, logical_block, rep_block, nb_erases, erase_mark;
569 unsigned int block, first_block, is_first_block;
570 int chain_length, do_format_chain;
571 struct nftl_uci0 h0;
572 struct nftl_uci1 h1;
573 struct mtd_info *mtd = s->mbd.mtd;
574 size_t retlen;
575
576 /* search for NFTL MediaHeader and Spare NFTL Media Header */
577 if (find_boot_record(s) < 0) {
578 printk("Could not find valid boot record\n");
579 return -1;
580 }
581
582 /* init the logical to physical table */
583 for (i = 0; i < s->nb_blocks; i++) {
584 s->EUNtable[i] = BLOCK_NIL;
585 }
586
587 /* first pass : explore each block chain */
588 first_logical_block = 0;
589 for (first_block = 0; first_block < s->nb_blocks; first_block++) {
590 /* if the block was not already explored, we can look at it */
591 if (s->ReplUnitTable[first_block] == BLOCK_NOTEXPLORED) {
592 block = first_block;
593 chain_length = 0;
594 do_format_chain = 0;
595
596 for (;;) {
597 /* read the block header. If error, we format the chain */
598 if (nftl_read_oob(mtd,
599 block * s->EraseSize + 8, 8,
600 &retlen, (char *)&h0) < 0 ||
601 nftl_read_oob(mtd,
602 block * s->EraseSize +
603 SECTORSIZE + 8, 8,
604 &retlen, (char *)&h1) < 0) {
605 s->ReplUnitTable[block] = BLOCK_NIL;
606 do_format_chain = 1;
607 break;
608 }
609
610 logical_block = le16_to_cpu ((h0.VirtUnitNum | h0.SpareVirtUnitNum));
611 rep_block = le16_to_cpu ((h0.ReplUnitNum | h0.SpareReplUnitNum));
612 nb_erases = le32_to_cpu (h1.WearInfo);
613 erase_mark = le16_to_cpu ((h1.EraseMark | h1.EraseMark1));
614
615 is_first_block = !(logical_block >> 15);
616 logical_block = logical_block & 0x7fff;
617
618 /* invalid/free block test */
619 if (erase_mark != ERASE_MARK || logical_block >= s->nb_blocks) {
620 if (chain_length == 0) {
621 /* if not currently in a chain, we can handle it safely */
622 if (check_and_mark_free_block(s, block) < 0) {
623 /* not really free: format it */
624 printk("Formatting block %d\n", block);
625 if (NFTL_formatblock(s, block) < 0) {
626 /* could not format: reserve the block */
627 s->ReplUnitTable[block] = BLOCK_RESERVED;
628 } else {
629 s->ReplUnitTable[block] = BLOCK_FREE;
630 }
631 } else {
632 /* free block: mark it */
633 s->ReplUnitTable[block] = BLOCK_FREE;
634 }
635 /* directly examine the next block. */
636 goto examine_ReplUnitTable;
637 } else {
638 /* the block was in a chain : this is bad. We
639 must format all the chain */
640 printk("Block %d: free but referenced in chain %d\n",
641 block, first_block);
642 s->ReplUnitTable[block] = BLOCK_NIL;
643 do_format_chain = 1;
644 break;
645 }
646 }
647
648 /* we accept only first blocks here */
649 if (chain_length == 0) {
650 /* this block is not the first block in chain :
651 ignore it, it will be included in a chain
652 later, or marked as not explored */
653 if (!is_first_block)
654 goto examine_ReplUnitTable;
655 first_logical_block = logical_block;
656 } else {
657 if (logical_block != first_logical_block) {
658 printk("Block %d: incorrect logical block: %d expected: %d\n",
659 block, logical_block, first_logical_block);
660 /* the chain is incorrect : we must format it,
661 but we need to read it completely */
662 do_format_chain = 1;
663 }
664 if (is_first_block) {
665 /* we accept that a block is marked as first
666 block while being last block in a chain
667 only if the chain is being folded */
668 if (get_fold_mark(s, block) != FOLD_MARK_IN_PROGRESS ||
669 rep_block != 0xffff) {
670 printk("Block %d: incorrectly marked as first block in chain\n",
671 block);
672 /* the chain is incorrect : we must format it,
673 but we need to read it completely */
674 do_format_chain = 1;
675 } else {
676 printk("Block %d: folding in progress - ignoring first block flag\n",
677 block);
678 }
679 }
680 }
681 chain_length++;
682 if (rep_block == 0xffff) {
683 /* no more blocks after */
684 s->ReplUnitTable[block] = BLOCK_NIL;
685 break;
686 } else if (rep_block >= s->nb_blocks) {
687 printk("Block %d: referencing invalid block %d\n",
688 block, rep_block);
689 do_format_chain = 1;
690 s->ReplUnitTable[block] = BLOCK_NIL;
691 break;
692 } else if (s->ReplUnitTable[rep_block] != BLOCK_NOTEXPLORED) {
693 /* same problem as previous 'is_first_block' test:
694 we accept that the last block of a chain has
695 the first_block flag set if folding is in
696 progress. We handle here the case where the
697 last block appeared first */
698 if (s->ReplUnitTable[rep_block] == BLOCK_NIL &&
699 s->EUNtable[first_logical_block] == rep_block &&
700 get_fold_mark(s, first_block) == FOLD_MARK_IN_PROGRESS) {
701 /* EUNtable[] will be set after */
702 printk("Block %d: folding in progress - ignoring first block flag\n",
703 rep_block);
704 s->ReplUnitTable[block] = rep_block;
705 s->EUNtable[first_logical_block] = BLOCK_NIL;
706 } else {
707 printk("Block %d: referencing block %d already in another chain\n",
708 block, rep_block);
709 /* XXX: should handle correctly fold in progress chains */
710 do_format_chain = 1;
711 s->ReplUnitTable[block] = BLOCK_NIL;
712 }
713 break;
714 } else {
715 /* this is OK */
716 s->ReplUnitTable[block] = rep_block;
717 block = rep_block;
718 }
719 }
720
721 /* the chain was completely explored. Now we can decide
722 what to do with it */
723 if (do_format_chain) {
724 /* invalid chain : format it */
725 format_chain(s, first_block);
726 } else {
727 unsigned int first_block1, chain_to_format, chain_length1;
728 int fold_mark;
729
730 /* valid chain : get foldmark */
731 fold_mark = get_fold_mark(s, first_block);
732 if (fold_mark == 0) {
733 /* cannot get foldmark : format the chain */
734 printk("Could read foldmark at block %d\n", first_block);
735 format_chain(s, first_block);
736 } else {
737 if (fold_mark == FOLD_MARK_IN_PROGRESS)
738 check_sectors_in_chain(s, first_block);
739
740 /* now handle the case where we find two chains at the
741 same virtual address : we select the longer one,
742 because the shorter one is the one which was being
743 folded if the folding was not done in place */
744 first_block1 = s->EUNtable[first_logical_block];
745 if (first_block1 != BLOCK_NIL) {
746 /* XXX: what to do if same length ? */
747 chain_length1 = calc_chain_length(s, first_block1);
748 printk("Two chains at blocks %d (len=%d) and %d (len=%d)\n",
749 first_block1, chain_length1, first_block, chain_length);
750
751 if (chain_length >= chain_length1) {
752 chain_to_format = first_block1;
753 s->EUNtable[first_logical_block] = first_block;
754 } else {
755 chain_to_format = first_block;
756 }
757 format_chain(s, chain_to_format);
758 } else {
759 s->EUNtable[first_logical_block] = first_block;
760 }
761 }
762 }
763 }
764 examine_ReplUnitTable:;
765 }
766
767 /* second pass to format unreferenced blocks and init free block count */
768 s->numfreeEUNs = 0;
769 s->LastFreeEUN = le16_to_cpu(s->MediaHdr.FirstPhysicalEUN);
770
771 for (block = 0; block < s->nb_blocks; block++) {
772 if (s->ReplUnitTable[block] == BLOCK_NOTEXPLORED) {
773 printk("Unreferenced block %d, formatting it\n", block);
774 if (NFTL_formatblock(s, block) < 0)
775 s->ReplUnitTable[block] = BLOCK_RESERVED;
776 else
777 s->ReplUnitTable[block] = BLOCK_FREE;
778 }
779 if (s->ReplUnitTable[block] == BLOCK_FREE) {
780 s->numfreeEUNs++;
781 s->LastFreeEUN = block;
782 }
783 }
784
785 return 0;
786 }