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1/*
2 * Copyright (c) International Business Machines Corp., 2006
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Artem Bityutskiy (Битюцкий Артём)
19 */
20
21/*
22 * UBI attaching sub-system.
23 *
24 * This sub-system is responsible for attaching MTD devices and it also
25 * implements flash media scanning.
26 *
27 * The attaching information is represented by a &struct ubi_attach_info'
28 * object. Information about volumes is represented by &struct ubi_ainf_volume
29 * objects which are kept in volume RB-tree with root at the @volumes field.
30 * The RB-tree is indexed by the volume ID.
31 *
32 * Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
33 * objects are kept in per-volume RB-trees with the root at the corresponding
34 * &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
35 * per-volume objects and each of these objects is the root of RB-tree of
36 * per-LEB objects.
37 *
38 * Corrupted physical eraseblocks are put to the @corr list, free physical
39 * eraseblocks are put to the @free list and the physical eraseblock to be
40 * erased are put to the @erase list.
41 *
42 * About corruptions
43 * ~~~~~~~~~~~~~~~~~
44 *
45 * UBI protects EC and VID headers with CRC-32 checksums, so it can detect
46 * whether the headers are corrupted or not. Sometimes UBI also protects the
47 * data with CRC-32, e.g., when it executes the atomic LEB change operation, or
48 * when it moves the contents of a PEB for wear-leveling purposes.
49 *
50 * UBI tries to distinguish between 2 types of corruptions.
51 *
52 * 1. Corruptions caused by power cuts. These are expected corruptions and UBI
53 * tries to handle them gracefully, without printing too many warnings and
54 * error messages. The idea is that we do not lose important data in these
55 * cases - we may lose only the data which were being written to the media just
56 * before the power cut happened, and the upper layers (e.g., UBIFS) are
57 * supposed to handle such data losses (e.g., by using the FS journal).
58 *
59 * When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
60 * the reason is a power cut, UBI puts this PEB to the @erase list, and all
61 * PEBs in the @erase list are scheduled for erasure later.
62 *
63 * 2. Unexpected corruptions which are not caused by power cuts. During
64 * attaching, such PEBs are put to the @corr list and UBI preserves them.
65 * Obviously, this lessens the amount of available PEBs, and if at some point
66 * UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
67 * about such PEBs every time the MTD device is attached.
68 *
69 * However, it is difficult to reliably distinguish between these types of
70 * corruptions and UBI's strategy is as follows (in case of attaching by
71 * scanning). UBI assumes corruption type 2 if the VID header is corrupted and
72 * the data area does not contain all 0xFFs, and there were no bit-flips or
73 * integrity errors (e.g., ECC errors in case of NAND) while reading the data
74 * area. Otherwise UBI assumes corruption type 1. So the decision criteria
75 * are as follows.
76 * o If the data area contains only 0xFFs, there are no data, and it is safe
77 * to just erase this PEB - this is corruption type 1.
78 * o If the data area has bit-flips or data integrity errors (ECC errors on
79 * NAND), it is probably a PEB which was being erased when power cut
80 * happened, so this is corruption type 1. However, this is just a guess,
81 * which might be wrong.
82 * o Otherwise this it corruption type 2.
83 */
84
85#include <linux/err.h>
86#include <linux/slab.h>
87#include <linux/crc32.h>
88#include <linux/math64.h>
89#include <linux/random.h>
90#include "ubi.h"
91
92static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);
93
94/* Temporary variables used during scanning */
95static struct ubi_ec_hdr *ech;
96static struct ubi_vid_hdr *vidh;
97
98/**
99 * add_to_list - add physical eraseblock to a list.
100 * @ai: attaching information
101 * @pnum: physical eraseblock number to add
102 * @ec: erase counter of the physical eraseblock
103 * @to_head: if not zero, add to the head of the list
104 * @list: the list to add to
105 *
106 * This function allocates a 'struct ubi_ainf_peb' object for physical
107 * eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
108 * If @to_head is not zero, PEB will be added to the head of the list, which
109 * basically means it will be processed first later. E.g., we add corrupted
110 * PEBs (corrupted due to power cuts) to the head of the erase list to make
111 * sure we erase them first and get rid of corruptions ASAP. This function
112 * returns zero in case of success and a negative error code in case of
113 * failure.
114 */
115static int add_to_list(struct ubi_attach_info *ai, int pnum, int ec,
116 int to_head, struct list_head *list)
117{
118 struct ubi_ainf_peb *aeb;
119
120 if (list == &ai->free) {
121 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
122 } else if (list == &ai->erase) {
123 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
124 } else if (list == &ai->alien) {
125 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
126 ai->alien_peb_count += 1;
127 } else
128 BUG();
129
130 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
131 if (!aeb)
132 return -ENOMEM;
133
134 aeb->pnum = pnum;
135 aeb->ec = ec;
136 if (to_head)
137 list_add(&aeb->u.list, list);
138 else
139 list_add_tail(&aeb->u.list, list);
140 return 0;
141}
142
143/**
144 * add_corrupted - add a corrupted physical eraseblock.
145 * @ai: attaching information
146 * @pnum: physical eraseblock number to add
147 * @ec: erase counter of the physical eraseblock
148 *
149 * This function allocates a 'struct ubi_ainf_peb' object for a corrupted
150 * physical eraseblock @pnum and adds it to the 'corr' list. The corruption
151 * was presumably not caused by a power cut. Returns zero in case of success
152 * and a negative error code in case of failure.
153 */
154static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
155{
156 struct ubi_ainf_peb *aeb;
157
158 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
159
160 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
161 if (!aeb)
162 return -ENOMEM;
163
164 ai->corr_peb_count += 1;
165 aeb->pnum = pnum;
166 aeb->ec = ec;
167 list_add(&aeb->u.list, &ai->corr);
168 return 0;
169}
170
171/**
172 * validate_vid_hdr - check volume identifier header.
173 * @vid_hdr: the volume identifier header to check
174 * @av: information about the volume this logical eraseblock belongs to
175 * @pnum: physical eraseblock number the VID header came from
176 *
177 * This function checks that data stored in @vid_hdr is consistent. Returns
178 * non-zero if an inconsistency was found and zero if not.
179 *
180 * Note, UBI does sanity check of everything it reads from the flash media.
181 * Most of the checks are done in the I/O sub-system. Here we check that the
182 * information in the VID header is consistent to the information in other VID
183 * headers of the same volume.
184 */
185static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
186 const struct ubi_ainf_volume *av, int pnum)
187{
188 int vol_type = vid_hdr->vol_type;
189 int vol_id = be32_to_cpu(vid_hdr->vol_id);
190 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
191 int data_pad = be32_to_cpu(vid_hdr->data_pad);
192
193 if (av->leb_count != 0) {
194 int av_vol_type;
195
196 /*
197 * This is not the first logical eraseblock belonging to this
198 * volume. Ensure that the data in its VID header is consistent
199 * to the data in previous logical eraseblock headers.
200 */
201
202 if (vol_id != av->vol_id) {
203 ubi_err("inconsistent vol_id");
204 goto bad;
205 }
206
207 if (av->vol_type == UBI_STATIC_VOLUME)
208 av_vol_type = UBI_VID_STATIC;
209 else
210 av_vol_type = UBI_VID_DYNAMIC;
211
212 if (vol_type != av_vol_type) {
213 ubi_err("inconsistent vol_type");
214 goto bad;
215 }
216
217 if (used_ebs != av->used_ebs) {
218 ubi_err("inconsistent used_ebs");
219 goto bad;
220 }
221
222 if (data_pad != av->data_pad) {
223 ubi_err("inconsistent data_pad");
224 goto bad;
225 }
226 }
227
228 return 0;
229
230bad:
231 ubi_err("inconsistent VID header at PEB %d", pnum);
232 ubi_dump_vid_hdr(vid_hdr);
233 ubi_dump_av(av);
234 return -EINVAL;
235}
236
237/**
238 * add_volume - add volume to the attaching information.
239 * @ai: attaching information
240 * @vol_id: ID of the volume to add
241 * @pnum: physical eraseblock number
242 * @vid_hdr: volume identifier header
243 *
244 * If the volume corresponding to the @vid_hdr logical eraseblock is already
245 * present in the attaching information, this function does nothing. Otherwise
246 * it adds corresponding volume to the attaching information. Returns a pointer
247 * to the allocated "av" object in case of success and a negative error code in
248 * case of failure.
249 */
250static struct ubi_ainf_volume *add_volume(struct ubi_attach_info *ai,
251 int vol_id, int pnum,
252 const struct ubi_vid_hdr *vid_hdr)
253{
254 struct ubi_ainf_volume *av;
255 struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
256
257 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
258
259 /* Walk the volume RB-tree to look if this volume is already present */
260 while (*p) {
261 parent = *p;
262 av = rb_entry(parent, struct ubi_ainf_volume, rb);
263
264 if (vol_id == av->vol_id)
265 return av;
266
267 if (vol_id > av->vol_id)
268 p = &(*p)->rb_left;
269 else
270 p = &(*p)->rb_right;
271 }
272
273 /* The volume is absent - add it */
274 av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
275 if (!av)
276 return ERR_PTR(-ENOMEM);
277
278 av->highest_lnum = av->leb_count = 0;
279 av->vol_id = vol_id;
280 av->root = RB_ROOT;
281 av->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
282 av->data_pad = be32_to_cpu(vid_hdr->data_pad);
283 av->compat = vid_hdr->compat;
284 av->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
285 : UBI_STATIC_VOLUME;
286 if (vol_id > ai->highest_vol_id)
287 ai->highest_vol_id = vol_id;
288
289 rb_link_node(&av->rb, parent, p);
290 rb_insert_color(&av->rb, &ai->volumes);
291 ai->vols_found += 1;
292 dbg_bld("added volume %d", vol_id);
293 return av;
294}
295
296/**
297 * compare_lebs - find out which logical eraseblock is newer.
298 * @ubi: UBI device description object
299 * @aeb: first logical eraseblock to compare
300 * @pnum: physical eraseblock number of the second logical eraseblock to
301 * compare
302 * @vid_hdr: volume identifier header of the second logical eraseblock
303 *
304 * This function compares 2 copies of a LEB and informs which one is newer. In
305 * case of success this function returns a positive value, in case of failure, a
306 * negative error code is returned. The success return codes use the following
307 * bits:
308 * o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
309 * second PEB (described by @pnum and @vid_hdr);
310 * o bit 0 is set: the second PEB is newer;
311 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
312 * o bit 1 is set: bit-flips were detected in the newer LEB;
313 * o bit 2 is cleared: the older LEB is not corrupted;
314 * o bit 2 is set: the older LEB is corrupted.
315 */
316static int compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
317 int pnum, const struct ubi_vid_hdr *vid_hdr)
318{
319 void *buf;
320 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
321 uint32_t data_crc, crc;
322 struct ubi_vid_hdr *vh = NULL;
323 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
324
325 if (sqnum2 == aeb->sqnum) {
326 /*
327 * This must be a really ancient UBI image which has been
328 * created before sequence numbers support has been added. At
329 * that times we used 32-bit LEB versions stored in logical
330 * eraseblocks. That was before UBI got into mainline. We do not
331 * support these images anymore. Well, those images still work,
332 * but only if no unclean reboots happened.
333 */
334 ubi_err("unsupported on-flash UBI format\n");
335 return -EINVAL;
336 }
337
338 /* Obviously the LEB with lower sequence counter is older */
339 second_is_newer = (sqnum2 > aeb->sqnum);
340
341 /*
342 * Now we know which copy is newer. If the copy flag of the PEB with
343 * newer version is not set, then we just return, otherwise we have to
344 * check data CRC. For the second PEB we already have the VID header,
345 * for the first one - we'll need to re-read it from flash.
346 *
347 * Note: this may be optimized so that we wouldn't read twice.
348 */
349
350 if (second_is_newer) {
351 if (!vid_hdr->copy_flag) {
352 /* It is not a copy, so it is newer */
353 dbg_bld("second PEB %d is newer, copy_flag is unset",
354 pnum);
355 return 1;
356 }
357 } else {
358 if (!aeb->copy_flag) {
359 /* It is not a copy, so it is newer */
360 dbg_bld("first PEB %d is newer, copy_flag is unset",
361 pnum);
362 return bitflips << 1;
363 }
364
365 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
366 if (!vh)
367 return -ENOMEM;
368
369 pnum = aeb->pnum;
370 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
371 if (err) {
372 if (err == UBI_IO_BITFLIPS)
373 bitflips = 1;
374 else {
375 ubi_err("VID of PEB %d header is bad, but it "
376 "was OK earlier, err %d", pnum, err);
377 if (err > 0)
378 err = -EIO;
379
380 goto out_free_vidh;
381 }
382 }
383
384 vid_hdr = vh;
385 }
386
387 /* Read the data of the copy and check the CRC */
388
389 len = be32_to_cpu(vid_hdr->data_size);
390 buf = vmalloc(len);
391 if (!buf) {
392 err = -ENOMEM;
393 goto out_free_vidh;
394 }
395
396 err = ubi_io_read_data(ubi, buf, pnum, 0, len);
397 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
398 goto out_free_buf;
399
400 data_crc = be32_to_cpu(vid_hdr->data_crc);
401 crc = crc32(UBI_CRC32_INIT, buf, len);
402 if (crc != data_crc) {
403 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
404 pnum, crc, data_crc);
405 corrupted = 1;
406 bitflips = 0;
407 second_is_newer = !second_is_newer;
408 } else {
409 dbg_bld("PEB %d CRC is OK", pnum);
410 bitflips = !!err;
411 }
412
413 vfree(buf);
414 ubi_free_vid_hdr(ubi, vh);
415
416 if (second_is_newer)
417 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
418 else
419 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
420
421 return second_is_newer | (bitflips << 1) | (corrupted << 2);
422
423out_free_buf:
424 vfree(buf);
425out_free_vidh:
426 ubi_free_vid_hdr(ubi, vh);
427 return err;
428}
429
430/**
431 * ubi_add_to_av - add used physical eraseblock to the attaching information.
432 * @ubi: UBI device description object
433 * @ai: attaching information
434 * @pnum: the physical eraseblock number
435 * @ec: erase counter
436 * @vid_hdr: the volume identifier header
437 * @bitflips: if bit-flips were detected when this physical eraseblock was read
438 *
439 * This function adds information about a used physical eraseblock to the
440 * 'used' tree of the corresponding volume. The function is rather complex
441 * because it has to handle cases when this is not the first physical
442 * eraseblock belonging to the same logical eraseblock, and the newer one has
443 * to be picked, while the older one has to be dropped. This function returns
444 * zero in case of success and a negative error code in case of failure.
445 */
446int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
447 int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
448{
449 int err, vol_id, lnum;
450 unsigned long long sqnum;
451 struct ubi_ainf_volume *av;
452 struct ubi_ainf_peb *aeb;
453 struct rb_node **p, *parent = NULL;
454
455 vol_id = be32_to_cpu(vid_hdr->vol_id);
456 lnum = be32_to_cpu(vid_hdr->lnum);
457 sqnum = be64_to_cpu(vid_hdr->sqnum);
458
459 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
460 pnum, vol_id, lnum, ec, sqnum, bitflips);
461
462 av = add_volume(ai, vol_id, pnum, vid_hdr);
463 if (IS_ERR(av))
464 return PTR_ERR(av);
465
466 if (ai->max_sqnum < sqnum)
467 ai->max_sqnum = sqnum;
468
469 /*
470 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
471 * if this is the first instance of this logical eraseblock or not.
472 */
473 p = &av->root.rb_node;
474 while (*p) {
475 int cmp_res;
476
477 parent = *p;
478 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
479 if (lnum != aeb->lnum) {
480 if (lnum < aeb->lnum)
481 p = &(*p)->rb_left;
482 else
483 p = &(*p)->rb_right;
484 continue;
485 }
486
487 /*
488 * There is already a physical eraseblock describing the same
489 * logical eraseblock present.
490 */
491
492 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
493 aeb->pnum, aeb->sqnum, aeb->ec);
494
495 /*
496 * Make sure that the logical eraseblocks have different
497 * sequence numbers. Otherwise the image is bad.
498 *
499 * However, if the sequence number is zero, we assume it must
500 * be an ancient UBI image from the era when UBI did not have
501 * sequence numbers. We still can attach these images, unless
502 * there is a need to distinguish between old and new
503 * eraseblocks, in which case we'll refuse the image in
504 * 'compare_lebs()'. In other words, we attach old clean
505 * images, but refuse attaching old images with duplicated
506 * logical eraseblocks because there was an unclean reboot.
507 */
508 if (aeb->sqnum == sqnum && sqnum != 0) {
509 ubi_err("two LEBs with same sequence number %llu",
510 sqnum);
511 ubi_dump_aeb(aeb, 0);
512 ubi_dump_vid_hdr(vid_hdr);
513 return -EINVAL;
514 }
515
516 /*
517 * Now we have to drop the older one and preserve the newer
518 * one.
519 */
520 cmp_res = compare_lebs(ubi, aeb, pnum, vid_hdr);
521 if (cmp_res < 0)
522 return cmp_res;
523
524 if (cmp_res & 1) {
525 /*
526 * This logical eraseblock is newer than the one
527 * found earlier.
528 */
529 err = validate_vid_hdr(vid_hdr, av, pnum);
530 if (err)
531 return err;
532
533 err = add_to_list(ai, aeb->pnum, aeb->ec, cmp_res & 4,
534 &ai->erase);
535 if (err)
536 return err;
537
538 aeb->ec = ec;
539 aeb->pnum = pnum;
540 aeb->scrub = ((cmp_res & 2) || bitflips);
541 aeb->copy_flag = vid_hdr->copy_flag;
542 aeb->sqnum = sqnum;
543
544 if (av->highest_lnum == lnum)
545 av->last_data_size =
546 be32_to_cpu(vid_hdr->data_size);
547
548 return 0;
549 } else {
550 /*
551 * This logical eraseblock is older than the one found
552 * previously.
553 */
554 return add_to_list(ai, pnum, ec, cmp_res & 4,
555 &ai->erase);
556 }
557 }
558
559 /*
560 * We've met this logical eraseblock for the first time, add it to the
561 * attaching information.
562 */
563
564 err = validate_vid_hdr(vid_hdr, av, pnum);
565 if (err)
566 return err;
567
568 aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
569 if (!aeb)
570 return -ENOMEM;
571
572 aeb->ec = ec;
573 aeb->pnum = pnum;
574 aeb->lnum = lnum;
575 aeb->scrub = bitflips;
576 aeb->copy_flag = vid_hdr->copy_flag;
577 aeb->sqnum = sqnum;
578
579 if (av->highest_lnum <= lnum) {
580 av->highest_lnum = lnum;
581 av->last_data_size = be32_to_cpu(vid_hdr->data_size);
582 }
583
584 av->leb_count += 1;
585 rb_link_node(&aeb->u.rb, parent, p);
586 rb_insert_color(&aeb->u.rb, &av->root);
587 return 0;
588}
589
590/**
591 * ubi_find_av - find volume in the attaching information.
592 * @ai: attaching information
593 * @vol_id: the requested volume ID
594 *
595 * This function returns a pointer to the volume description or %NULL if there
596 * are no data about this volume in the attaching information.
597 */
598struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
599 int vol_id)
600{
601 struct ubi_ainf_volume *av;
602 struct rb_node *p = ai->volumes.rb_node;
603
604 while (p) {
605 av = rb_entry(p, struct ubi_ainf_volume, rb);
606
607 if (vol_id == av->vol_id)
608 return av;
609
610 if (vol_id > av->vol_id)
611 p = p->rb_left;
612 else
613 p = p->rb_right;
614 }
615
616 return NULL;
617}
618
619/**
620 * ubi_remove_av - delete attaching information about a volume.
621 * @ai: attaching information
622 * @av: the volume attaching information to delete
623 */
624void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
625{
626 struct rb_node *rb;
627 struct ubi_ainf_peb *aeb;
628
629 dbg_bld("remove attaching information about volume %d", av->vol_id);
630
631 while ((rb = rb_first(&av->root))) {
632 aeb = rb_entry(rb, struct ubi_ainf_peb, u.rb);
633 rb_erase(&aeb->u.rb, &av->root);
634 list_add_tail(&aeb->u.list, &ai->erase);
635 }
636
637 rb_erase(&av->rb, &ai->volumes);
638 kfree(av);
639 ai->vols_found -= 1;
640}
641
642/**
643 * early_erase_peb - erase a physical eraseblock.
644 * @ubi: UBI device description object
645 * @ai: attaching information
646 * @pnum: physical eraseblock number to erase;
647 * @ec: erase counter value to write (%UBI_UNKNOWN if it is unknown)
648 *
649 * This function erases physical eraseblock 'pnum', and writes the erase
650 * counter header to it. This function should only be used on UBI device
651 * initialization stages, when the EBA sub-system had not been yet initialized.
652 * This function returns zero in case of success and a negative error code in
653 * case of failure.
654 */
655static int early_erase_peb(struct ubi_device *ubi,
656 const struct ubi_attach_info *ai, int pnum, int ec)
657{
658 int err;
659 struct ubi_ec_hdr *ec_hdr;
660
661 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
662 /*
663 * Erase counter overflow. Upgrade UBI and use 64-bit
664 * erase counters internally.
665 */
666 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
667 return -EINVAL;
668 }
669
670 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
671 if (!ec_hdr)
672 return -ENOMEM;
673
674 ec_hdr->ec = cpu_to_be64(ec);
675
676 err = ubi_io_sync_erase(ubi, pnum, 0);
677 if (err < 0)
678 goto out_free;
679
680 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
681
682out_free:
683 kfree(ec_hdr);
684 return err;
685}
686
687/**
688 * ubi_early_get_peb - get a free physical eraseblock.
689 * @ubi: UBI device description object
690 * @ai: attaching information
691 *
692 * This function returns a free physical eraseblock. It is supposed to be
693 * called on the UBI initialization stages when the wear-leveling sub-system is
694 * not initialized yet. This function picks a physical eraseblocks from one of
695 * the lists, writes the EC header if it is needed, and removes it from the
696 * list.
697 *
698 * This function returns a pointer to the "aeb" of the found free PEB in case
699 * of success and an error code in case of failure.
700 */
701struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
702 struct ubi_attach_info *ai)
703{
704 int err = 0;
705 struct ubi_ainf_peb *aeb, *tmp_aeb;
706
707 if (!list_empty(&ai->free)) {
708 aeb = list_entry(ai->free.next, struct ubi_ainf_peb, u.list);
709 list_del(&aeb->u.list);
710 dbg_bld("return free PEB %d, EC %d", aeb->pnum, aeb->ec);
711 return aeb;
712 }
713
714 /*
715 * We try to erase the first physical eraseblock from the erase list
716 * and pick it if we succeed, or try to erase the next one if not. And
717 * so forth. We don't want to take care about bad eraseblocks here -
718 * they'll be handled later.
719 */
720 list_for_each_entry_safe(aeb, tmp_aeb, &ai->erase, u.list) {
721 if (aeb->ec == UBI_UNKNOWN)
722 aeb->ec = ai->mean_ec;
723
724 err = early_erase_peb(ubi, ai, aeb->pnum, aeb->ec+1);
725 if (err)
726 continue;
727
728 aeb->ec += 1;
729 list_del(&aeb->u.list);
730 dbg_bld("return PEB %d, EC %d", aeb->pnum, aeb->ec);
731 return aeb;
732 }
733
734 ubi_err("no free eraseblocks");
735 return ERR_PTR(-ENOSPC);
736}
737
738/**
739 * check_corruption - check the data area of PEB.
740 * @ubi: UBI device description object
741 * @vid_hrd: the (corrupted) VID header of this PEB
742 * @pnum: the physical eraseblock number to check
743 *
744 * This is a helper function which is used to distinguish between VID header
745 * corruptions caused by power cuts and other reasons. If the PEB contains only
746 * 0xFF bytes in the data area, the VID header is most probably corrupted
747 * because of a power cut (%0 is returned in this case). Otherwise, it was
748 * probably corrupted for some other reasons (%1 is returned in this case). A
749 * negative error code is returned if a read error occurred.
750 *
751 * If the corruption reason was a power cut, UBI can safely erase this PEB.
752 * Otherwise, it should preserve it to avoid possibly destroying important
753 * information.
754 */
755static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
756 int pnum)
757{
758 int err;
759
760 mutex_lock(&ubi->buf_mutex);
761 memset(ubi->peb_buf, 0x00, ubi->leb_size);
762
763 err = ubi_io_read(ubi, ubi->peb_buf, pnum, ubi->leb_start,
764 ubi->leb_size);
765 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
766 /*
767 * Bit-flips or integrity errors while reading the data area.
768 * It is difficult to say for sure what type of corruption is
769 * this, but presumably a power cut happened while this PEB was
770 * erased, so it became unstable and corrupted, and should be
771 * erased.
772 */
773 err = 0;
774 goto out_unlock;
775 }
776
777 if (err)
778 goto out_unlock;
779
780 if (ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->leb_size))
781 goto out_unlock;
782
783 ubi_err("PEB %d contains corrupted VID header, and the data does not "
784 "contain all 0xFF, this may be a non-UBI PEB or a severe VID "
785 "header corruption which requires manual inspection", pnum);
786 ubi_dump_vid_hdr(vid_hdr);
787 dbg_msg("hexdump of PEB %d offset %d, length %d",
788 pnum, ubi->leb_start, ubi->leb_size);
789 ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
790 ubi->peb_buf, ubi->leb_size, 1);
791 err = 1;
792
793out_unlock:
794 mutex_unlock(&ubi->buf_mutex);
795 return err;
796}
797
798/**
799 * scan_peb - scan and process UBI headers of a PEB.
800 * @ubi: UBI device description object
801 * @ai: attaching information
802 * @pnum: the physical eraseblock number
803 *
804 * This function reads UBI headers of PEB @pnum, checks them, and adds
805 * information about this PEB to the corresponding list or RB-tree in the
806 * "attaching info" structure. Returns zero if the physical eraseblock was
807 * successfully handled and a negative error code in case of failure.
808 */
809static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
810 int pnum)
811{
812 long long uninitialized_var(ec);
813 int err, bitflips = 0, vol_id, ec_err = 0;
814
815 dbg_bld("scan PEB %d", pnum);
816
817 /* Skip bad physical eraseblocks */
818 err = ubi_io_is_bad(ubi, pnum);
819 if (err < 0)
820 return err;
821 else if (err) {
822 ai->bad_peb_count += 1;
823 return 0;
824 }
825
826 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
827 if (err < 0)
828 return err;
829 switch (err) {
830 case 0:
831 break;
832 case UBI_IO_BITFLIPS:
833 bitflips = 1;
834 break;
835 case UBI_IO_FF:
836 ai->empty_peb_count += 1;
837 return add_to_list(ai, pnum, UBI_UNKNOWN, 0,
838 &ai->erase);
839 case UBI_IO_FF_BITFLIPS:
840 ai->empty_peb_count += 1;
841 return add_to_list(ai, pnum, UBI_UNKNOWN, 1,
842 &ai->erase);
843 case UBI_IO_BAD_HDR_EBADMSG:
844 case UBI_IO_BAD_HDR:
845 /*
846 * We have to also look at the VID header, possibly it is not
847 * corrupted. Set %bitflips flag in order to make this PEB be
848 * moved and EC be re-created.
849 */
850 ec_err = err;
851 ec = UBI_UNKNOWN;
852 bitflips = 1;
853 break;
854 default:
855 ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
856 return -EINVAL;
857 }
858
859 if (!ec_err) {
860 int image_seq;
861
862 /* Make sure UBI version is OK */
863 if (ech->version != UBI_VERSION) {
864 ubi_err("this UBI version is %d, image version is %d",
865 UBI_VERSION, (int)ech->version);
866 return -EINVAL;
867 }
868
869 ec = be64_to_cpu(ech->ec);
870 if (ec > UBI_MAX_ERASECOUNTER) {
871 /*
872 * Erase counter overflow. The EC headers have 64 bits
873 * reserved, but we anyway make use of only 31 bit
874 * values, as this seems to be enough for any existing
875 * flash. Upgrade UBI and use 64-bit erase counters
876 * internally.
877 */
878 ubi_err("erase counter overflow, max is %d",
879 UBI_MAX_ERASECOUNTER);
880 ubi_dump_ec_hdr(ech);
881 return -EINVAL;
882 }
883
884 /*
885 * Make sure that all PEBs have the same image sequence number.
886 * This allows us to detect situations when users flash UBI
887 * images incorrectly, so that the flash has the new UBI image
888 * and leftovers from the old one. This feature was added
889 * relatively recently, and the sequence number was always
890 * zero, because old UBI implementations always set it to zero.
891 * For this reasons, we do not panic if some PEBs have zero
892 * sequence number, while other PEBs have non-zero sequence
893 * number.
894 */
895 image_seq = be32_to_cpu(ech->image_seq);
896 if (!ubi->image_seq && image_seq)
897 ubi->image_seq = image_seq;
898 if (ubi->image_seq && image_seq &&
899 ubi->image_seq != image_seq) {
900 ubi_err("bad image sequence number %d in PEB %d, "
901 "expected %d", image_seq, pnum, ubi->image_seq);
902 ubi_dump_ec_hdr(ech);
903 return -EINVAL;
904 }
905 }
906
907 /* OK, we've done with the EC header, let's look at the VID header */
908
909 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
910 if (err < 0)
911 return err;
912 switch (err) {
913 case 0:
914 break;
915 case UBI_IO_BITFLIPS:
916 bitflips = 1;
917 break;
918 case UBI_IO_BAD_HDR_EBADMSG:
919 if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
920 /*
921 * Both EC and VID headers are corrupted and were read
922 * with data integrity error, probably this is a bad
923 * PEB, bit it is not marked as bad yet. This may also
924 * be a result of power cut during erasure.
925 */
926 ai->maybe_bad_peb_count += 1;
927 case UBI_IO_BAD_HDR:
928 if (ec_err)
929 /*
930 * Both headers are corrupted. There is a possibility
931 * that this a valid UBI PEB which has corresponding
932 * LEB, but the headers are corrupted. However, it is
933 * impossible to distinguish it from a PEB which just
934 * contains garbage because of a power cut during erase
935 * operation. So we just schedule this PEB for erasure.
936 *
937 * Besides, in case of NOR flash, we deliberately
938 * corrupt both headers because NOR flash erasure is
939 * slow and can start from the end.
940 */
941 err = 0;
942 else
943 /*
944 * The EC was OK, but the VID header is corrupted. We
945 * have to check what is in the data area.
946 */
947 err = check_corruption(ubi, vidh, pnum);
948
949 if (err < 0)
950 return err;
951 else if (!err)
952 /* This corruption is caused by a power cut */
953 err = add_to_list(ai, pnum, ec, 1, &ai->erase);
954 else
955 /* This is an unexpected corruption */
956 err = add_corrupted(ai, pnum, ec);
957 if (err)
958 return err;
959 goto adjust_mean_ec;
960 case UBI_IO_FF_BITFLIPS:
961 err = add_to_list(ai, pnum, ec, 1, &ai->erase);
962 if (err)
963 return err;
964 goto adjust_mean_ec;
965 case UBI_IO_FF:
966 if (ec_err)
967 err = add_to_list(ai, pnum, ec, 1, &ai->erase);
968 else
969 err = add_to_list(ai, pnum, ec, 0, &ai->free);
970 if (err)
971 return err;
972 goto adjust_mean_ec;
973 default:
974 ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
975 err);
976 return -EINVAL;
977 }
978
979 vol_id = be32_to_cpu(vidh->vol_id);
980 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
981 int lnum = be32_to_cpu(vidh->lnum);
982
983 /* Unsupported internal volume */
984 switch (vidh->compat) {
985 case UBI_COMPAT_DELETE:
986 ubi_msg("\"delete\" compatible internal volume %d:%d"
987 " found, will remove it", vol_id, lnum);
988 err = add_to_list(ai, pnum, ec, 1, &ai->erase);
989 if (err)
990 return err;
991 return 0;
992
993 case UBI_COMPAT_RO:
994 ubi_msg("read-only compatible internal volume %d:%d"
995 " found, switch to read-only mode",
996 vol_id, lnum);
997 ubi->ro_mode = 1;
998 break;
999
1000 case UBI_COMPAT_PRESERVE:
1001 ubi_msg("\"preserve\" compatible internal volume %d:%d"
1002 " found", vol_id, lnum);
1003 err = add_to_list(ai, pnum, ec, 0, &ai->alien);
1004 if (err)
1005 return err;
1006 return 0;
1007
1008 case UBI_COMPAT_REJECT:
1009 ubi_err("incompatible internal volume %d:%d found",
1010 vol_id, lnum);
1011 return -EINVAL;
1012 }
1013 }
1014
1015 if (ec_err)
1016 ubi_warn("valid VID header but corrupted EC header at PEB %d",
1017 pnum);
1018 err = ubi_add_to_av(ubi, ai, pnum, ec, vidh, bitflips);
1019 if (err)
1020 return err;
1021
1022adjust_mean_ec:
1023 if (!ec_err) {
1024 ai->ec_sum += ec;
1025 ai->ec_count += 1;
1026 if (ec > ai->max_ec)
1027 ai->max_ec = ec;
1028 if (ec < ai->min_ec)
1029 ai->min_ec = ec;
1030 }
1031
1032 return 0;
1033}
1034
1035/**
1036 * late_analysis - analyze the overall situation with PEB.
1037 * @ubi: UBI device description object
1038 * @ai: attaching information
1039 *
1040 * This is a helper function which takes a look what PEBs we have after we
1041 * gather information about all of them ("ai" is compete). It decides whether
1042 * the flash is empty and should be formatted of whether there are too many
1043 * corrupted PEBs and we should not attach this MTD device. Returns zero if we
1044 * should proceed with attaching the MTD device, and %-EINVAL if we should not.
1045 */
1046static int late_analysis(struct ubi_device *ubi, struct ubi_attach_info *ai)
1047{
1048 struct ubi_ainf_peb *aeb;
1049 int max_corr, peb_count;
1050
1051 peb_count = ubi->peb_count - ai->bad_peb_count - ai->alien_peb_count;
1052 max_corr = peb_count / 20 ?: 8;
1053
1054 /*
1055 * Few corrupted PEBs is not a problem and may be just a result of
1056 * unclean reboots. However, many of them may indicate some problems
1057 * with the flash HW or driver.
1058 */
1059 if (ai->corr_peb_count) {
1060 ubi_err("%d PEBs are corrupted and preserved",
1061 ai->corr_peb_count);
1062 printk(KERN_ERR "Corrupted PEBs are:");
1063 list_for_each_entry(aeb, &ai->corr, u.list)
1064 printk(KERN_CONT " %d", aeb->pnum);
1065 printk(KERN_CONT "\n");
1066
1067 /*
1068 * If too many PEBs are corrupted, we refuse attaching,
1069 * otherwise, only print a warning.
1070 */
1071 if (ai->corr_peb_count >= max_corr) {
1072 ubi_err("too many corrupted PEBs, refusing");
1073 return -EINVAL;
1074 }
1075 }
1076
1077 if (ai->empty_peb_count + ai->maybe_bad_peb_count == peb_count) {
1078 /*
1079 * All PEBs are empty, or almost all - a couple PEBs look like
1080 * they may be bad PEBs which were not marked as bad yet.
1081 *
1082 * This piece of code basically tries to distinguish between
1083 * the following situations:
1084 *
1085 * 1. Flash is empty, but there are few bad PEBs, which are not
1086 * marked as bad so far, and which were read with error. We
1087 * want to go ahead and format this flash. While formatting,
1088 * the faulty PEBs will probably be marked as bad.
1089 *
1090 * 2. Flash contains non-UBI data and we do not want to format
1091 * it and destroy possibly important information.
1092 */
1093 if (ai->maybe_bad_peb_count <= 2) {
1094 ai->is_empty = 1;
1095 ubi_msg("empty MTD device detected");
1096 get_random_bytes(&ubi->image_seq,
1097 sizeof(ubi->image_seq));
1098 } else {
1099 ubi_err("MTD device is not UBI-formatted and possibly "
1100 "contains non-UBI data - refusing it");
1101 return -EINVAL;
1102 }
1103
1104 }
1105
1106 return 0;
1107}
1108
1109/**
1110 * scan_all - scan entire MTD device.
1111 * @ubi: UBI device description object
1112 *
1113 * This function does full scanning of an MTD device and returns complete
1114 * information about it in form of a "struct ubi_attach_info" object. In case
1115 * of failure, an error code is returned.
1116 */
1117static struct ubi_attach_info *scan_all(struct ubi_device *ubi)
1118{
1119 int err, pnum;
1120 struct rb_node *rb1, *rb2;
1121 struct ubi_ainf_volume *av;
1122 struct ubi_ainf_peb *aeb;
1123 struct ubi_attach_info *ai;
1124
1125 ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
1126 if (!ai)
1127 return ERR_PTR(-ENOMEM);
1128
1129 INIT_LIST_HEAD(&ai->corr);
1130 INIT_LIST_HEAD(&ai->free);
1131 INIT_LIST_HEAD(&ai->erase);
1132 INIT_LIST_HEAD(&ai->alien);
1133 ai->volumes = RB_ROOT;
1134
1135 err = -ENOMEM;
1136 ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
1137 sizeof(struct ubi_ainf_peb),
1138 0, 0, NULL);
1139 if (!ai->aeb_slab_cache)
1140 goto out_ai;
1141
1142 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1143 if (!ech)
1144 goto out_ai;
1145
1146 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1147 if (!vidh)
1148 goto out_ech;
1149
1150 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1151 cond_resched();
1152
1153 dbg_gen("process PEB %d", pnum);
1154 err = scan_peb(ubi, ai, pnum);
1155 if (err < 0)
1156 goto out_vidh;
1157 }
1158
1159 dbg_msg("scanning is finished");
1160
1161 /* Calculate mean erase counter */
1162 if (ai->ec_count)
1163 ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
1164
1165 err = late_analysis(ubi, ai);
1166 if (err)
1167 goto out_vidh;
1168
1169 /*
1170 * In case of unknown erase counter we use the mean erase counter
1171 * value.
1172 */
1173 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1174 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1175 if (aeb->ec == UBI_UNKNOWN)
1176 aeb->ec = ai->mean_ec;
1177 }
1178
1179 list_for_each_entry(aeb, &ai->free, u.list) {
1180 if (aeb->ec == UBI_UNKNOWN)
1181 aeb->ec = ai->mean_ec;
1182 }
1183
1184 list_for_each_entry(aeb, &ai->corr, u.list)
1185 if (aeb->ec == UBI_UNKNOWN)
1186 aeb->ec = ai->mean_ec;
1187
1188 list_for_each_entry(aeb, &ai->erase, u.list)
1189 if (aeb->ec == UBI_UNKNOWN)
1190 aeb->ec = ai->mean_ec;
1191
1192 err = self_check_ai(ubi, ai);
1193 if (err)
1194 goto out_vidh;
1195
1196 ubi_free_vid_hdr(ubi, vidh);
1197 kfree(ech);
1198
1199 return ai;
1200
1201out_vidh:
1202 ubi_free_vid_hdr(ubi, vidh);
1203out_ech:
1204 kfree(ech);
1205out_ai:
1206 ubi_destroy_ai(ai);
1207 return ERR_PTR(err);
1208}
1209
1210/**
1211 * ubi_attach - attach an MTD device.
1212 * @ubi: UBI device descriptor
1213 *
1214 * This function returns zero in case of success and a negative error code in
1215 * case of failure.
1216 */
1217int ubi_attach(struct ubi_device *ubi)
1218{
1219 int err;
1220 struct ubi_attach_info *ai;
1221
1222 ai = scan_all(ubi);
1223 if (IS_ERR(ai))
1224 return PTR_ERR(ai);
1225
1226 ubi->bad_peb_count = ai->bad_peb_count;
1227 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
1228 ubi->corr_peb_count = ai->corr_peb_count;
1229 ubi->max_ec = ai->max_ec;
1230 ubi->mean_ec = ai->mean_ec;
1231 ubi_msg("max. sequence number: %llu", ai->max_sqnum);
1232
1233 err = ubi_read_volume_table(ubi, ai);
1234 if (err)
1235 goto out_ai;
1236
1237 err = ubi_wl_init(ubi, ai);
1238 if (err)
1239 goto out_vtbl;
1240
1241 err = ubi_eba_init(ubi, ai);
1242 if (err)
1243 goto out_wl;
1244
1245 ubi_destroy_ai(ai);
1246 return 0;
1247
1248out_wl:
1249 ubi_wl_close(ubi);
1250out_vtbl:
1251 ubi_free_internal_volumes(ubi);
1252 vfree(ubi->vtbl);
1253out_ai:
1254 ubi_destroy_ai(ai);
1255 return err;
1256}
1257
1258/**
1259 * destroy_av - free volume attaching information.
1260 * @av: volume attaching information
1261 * @ai: attaching information
1262 *
1263 * This function destroys the volume attaching information.
1264 */
1265static void destroy_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av)
1266{
1267 struct ubi_ainf_peb *aeb;
1268 struct rb_node *this = av->root.rb_node;
1269
1270 while (this) {
1271 if (this->rb_left)
1272 this = this->rb_left;
1273 else if (this->rb_right)
1274 this = this->rb_right;
1275 else {
1276 aeb = rb_entry(this, struct ubi_ainf_peb, u.rb);
1277 this = rb_parent(this);
1278 if (this) {
1279 if (this->rb_left == &aeb->u.rb)
1280 this->rb_left = NULL;
1281 else
1282 this->rb_right = NULL;
1283 }
1284
1285 kmem_cache_free(ai->aeb_slab_cache, aeb);
1286 }
1287 }
1288 kfree(av);
1289}
1290
1291/**
1292 * ubi_destroy_ai - destroy attaching information.
1293 * @ai: attaching information
1294 */
1295void ubi_destroy_ai(struct ubi_attach_info *ai)
1296{
1297 struct ubi_ainf_peb *aeb, *aeb_tmp;
1298 struct ubi_ainf_volume *av;
1299 struct rb_node *rb;
1300
1301 list_for_each_entry_safe(aeb, aeb_tmp, &ai->alien, u.list) {
1302 list_del(&aeb->u.list);
1303 kmem_cache_free(ai->aeb_slab_cache, aeb);
1304 }
1305 list_for_each_entry_safe(aeb, aeb_tmp, &ai->erase, u.list) {
1306 list_del(&aeb->u.list);
1307 kmem_cache_free(ai->aeb_slab_cache, aeb);
1308 }
1309 list_for_each_entry_safe(aeb, aeb_tmp, &ai->corr, u.list) {
1310 list_del(&aeb->u.list);
1311 kmem_cache_free(ai->aeb_slab_cache, aeb);
1312 }
1313 list_for_each_entry_safe(aeb, aeb_tmp, &ai->free, u.list) {
1314 list_del(&aeb->u.list);
1315 kmem_cache_free(ai->aeb_slab_cache, aeb);
1316 }
1317
1318 /* Destroy the volume RB-tree */
1319 rb = ai->volumes.rb_node;
1320 while (rb) {
1321 if (rb->rb_left)
1322 rb = rb->rb_left;
1323 else if (rb->rb_right)
1324 rb = rb->rb_right;
1325 else {
1326 av = rb_entry(rb, struct ubi_ainf_volume, rb);
1327
1328 rb = rb_parent(rb);
1329 if (rb) {
1330 if (rb->rb_left == &av->rb)
1331 rb->rb_left = NULL;
1332 else
1333 rb->rb_right = NULL;
1334 }
1335
1336 destroy_av(ai, av);
1337 }
1338 }
1339
1340 if (ai->aeb_slab_cache)
1341 kmem_cache_destroy(ai->aeb_slab_cache);
1342
1343 kfree(ai);
1344}
1345
1346/**
1347 * self_check_ai - check the attaching information.
1348 * @ubi: UBI device description object
1349 * @ai: attaching information
1350 *
1351 * This function returns zero if the attaching information is all right, and a
1352 * negative error code if not or if an error occurred.
1353 */
1354static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
1355{
1356 int pnum, err, vols_found = 0;
1357 struct rb_node *rb1, *rb2;
1358 struct ubi_ainf_volume *av;
1359 struct ubi_ainf_peb *aeb, *last_aeb;
1360 uint8_t *buf;
1361
1362 if (!ubi->dbg->chk_gen)
1363 return 0;
1364
1365 /*
1366 * At first, check that attaching information is OK.
1367 */
1368 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1369 int leb_count = 0;
1370
1371 cond_resched();
1372
1373 vols_found += 1;
1374
1375 if (ai->is_empty) {
1376 ubi_err("bad is_empty flag");
1377 goto bad_av;
1378 }
1379
1380 if (av->vol_id < 0 || av->highest_lnum < 0 ||
1381 av->leb_count < 0 || av->vol_type < 0 || av->used_ebs < 0 ||
1382 av->data_pad < 0 || av->last_data_size < 0) {
1383 ubi_err("negative values");
1384 goto bad_av;
1385 }
1386
1387 if (av->vol_id >= UBI_MAX_VOLUMES &&
1388 av->vol_id < UBI_INTERNAL_VOL_START) {
1389 ubi_err("bad vol_id");
1390 goto bad_av;
1391 }
1392
1393 if (av->vol_id > ai->highest_vol_id) {
1394 ubi_err("highest_vol_id is %d, but vol_id %d is there",
1395 ai->highest_vol_id, av->vol_id);
1396 goto out;
1397 }
1398
1399 if (av->vol_type != UBI_DYNAMIC_VOLUME &&
1400 av->vol_type != UBI_STATIC_VOLUME) {
1401 ubi_err("bad vol_type");
1402 goto bad_av;
1403 }
1404
1405 if (av->data_pad > ubi->leb_size / 2) {
1406 ubi_err("bad data_pad");
1407 goto bad_av;
1408 }
1409
1410 last_aeb = NULL;
1411 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1412 cond_resched();
1413
1414 last_aeb = aeb;
1415 leb_count += 1;
1416
1417 if (aeb->pnum < 0 || aeb->ec < 0) {
1418 ubi_err("negative values");
1419 goto bad_aeb;
1420 }
1421
1422 if (aeb->ec < ai->min_ec) {
1423 ubi_err("bad ai->min_ec (%d), %d found",
1424 ai->min_ec, aeb->ec);
1425 goto bad_aeb;
1426 }
1427
1428 if (aeb->ec > ai->max_ec) {
1429 ubi_err("bad ai->max_ec (%d), %d found",
1430 ai->max_ec, aeb->ec);
1431 goto bad_aeb;
1432 }
1433
1434 if (aeb->pnum >= ubi->peb_count) {
1435 ubi_err("too high PEB number %d, total PEBs %d",
1436 aeb->pnum, ubi->peb_count);
1437 goto bad_aeb;
1438 }
1439
1440 if (av->vol_type == UBI_STATIC_VOLUME) {
1441 if (aeb->lnum >= av->used_ebs) {
1442 ubi_err("bad lnum or used_ebs");
1443 goto bad_aeb;
1444 }
1445 } else {
1446 if (av->used_ebs != 0) {
1447 ubi_err("non-zero used_ebs");
1448 goto bad_aeb;
1449 }
1450 }
1451
1452 if (aeb->lnum > av->highest_lnum) {
1453 ubi_err("incorrect highest_lnum or lnum");
1454 goto bad_aeb;
1455 }
1456 }
1457
1458 if (av->leb_count != leb_count) {
1459 ubi_err("bad leb_count, %d objects in the tree",
1460 leb_count);
1461 goto bad_av;
1462 }
1463
1464 if (!last_aeb)
1465 continue;
1466
1467 aeb = last_aeb;
1468
1469 if (aeb->lnum != av->highest_lnum) {
1470 ubi_err("bad highest_lnum");
1471 goto bad_aeb;
1472 }
1473 }
1474
1475 if (vols_found != ai->vols_found) {
1476 ubi_err("bad ai->vols_found %d, should be %d",
1477 ai->vols_found, vols_found);
1478 goto out;
1479 }
1480
1481 /* Check that attaching information is correct */
1482 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
1483 last_aeb = NULL;
1484 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
1485 int vol_type;
1486
1487 cond_resched();
1488
1489 last_aeb = aeb;
1490
1491 err = ubi_io_read_vid_hdr(ubi, aeb->pnum, vidh, 1);
1492 if (err && err != UBI_IO_BITFLIPS) {
1493 ubi_err("VID header is not OK (%d)", err);
1494 if (err > 0)
1495 err = -EIO;
1496 return err;
1497 }
1498
1499 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1500 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1501 if (av->vol_type != vol_type) {
1502 ubi_err("bad vol_type");
1503 goto bad_vid_hdr;
1504 }
1505
1506 if (aeb->sqnum != be64_to_cpu(vidh->sqnum)) {
1507 ubi_err("bad sqnum %llu", aeb->sqnum);
1508 goto bad_vid_hdr;
1509 }
1510
1511 if (av->vol_id != be32_to_cpu(vidh->vol_id)) {
1512 ubi_err("bad vol_id %d", av->vol_id);
1513 goto bad_vid_hdr;
1514 }
1515
1516 if (av->compat != vidh->compat) {
1517 ubi_err("bad compat %d", vidh->compat);
1518 goto bad_vid_hdr;
1519 }
1520
1521 if (aeb->lnum != be32_to_cpu(vidh->lnum)) {
1522 ubi_err("bad lnum %d", aeb->lnum);
1523 goto bad_vid_hdr;
1524 }
1525
1526 if (av->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1527 ubi_err("bad used_ebs %d", av->used_ebs);
1528 goto bad_vid_hdr;
1529 }
1530
1531 if (av->data_pad != be32_to_cpu(vidh->data_pad)) {
1532 ubi_err("bad data_pad %d", av->data_pad);
1533 goto bad_vid_hdr;
1534 }
1535 }
1536
1537 if (!last_aeb)
1538 continue;
1539
1540 if (av->highest_lnum != be32_to_cpu(vidh->lnum)) {
1541 ubi_err("bad highest_lnum %d", av->highest_lnum);
1542 goto bad_vid_hdr;
1543 }
1544
1545 if (av->last_data_size != be32_to_cpu(vidh->data_size)) {
1546 ubi_err("bad last_data_size %d", av->last_data_size);
1547 goto bad_vid_hdr;
1548 }
1549 }
1550
1551 /*
1552 * Make sure that all the physical eraseblocks are in one of the lists
1553 * or trees.
1554 */
1555 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1556 if (!buf)
1557 return -ENOMEM;
1558
1559 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1560 err = ubi_io_is_bad(ubi, pnum);
1561 if (err < 0) {
1562 kfree(buf);
1563 return err;
1564 } else if (err)
1565 buf[pnum] = 1;
1566 }
1567
1568 ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
1569 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
1570 buf[aeb->pnum] = 1;
1571
1572 list_for_each_entry(aeb, &ai->free, u.list)
1573 buf[aeb->pnum] = 1;
1574
1575 list_for_each_entry(aeb, &ai->corr, u.list)
1576 buf[aeb->pnum] = 1;
1577
1578 list_for_each_entry(aeb, &ai->erase, u.list)
1579 buf[aeb->pnum] = 1;
1580
1581 list_for_each_entry(aeb, &ai->alien, u.list)
1582 buf[aeb->pnum] = 1;
1583
1584 err = 0;
1585 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1586 if (!buf[pnum]) {
1587 ubi_err("PEB %d is not referred", pnum);
1588 err = 1;
1589 }
1590
1591 kfree(buf);
1592 if (err)
1593 goto out;
1594 return 0;
1595
1596bad_aeb:
1597 ubi_err("bad attaching information about LEB %d", aeb->lnum);
1598 ubi_dump_aeb(aeb, 0);
1599 ubi_dump_av(av);
1600 goto out;
1601
1602bad_av:
1603 ubi_err("bad attaching information about volume %d", av->vol_id);
1604 ubi_dump_av(av);
1605 goto out;
1606
1607bad_vid_hdr:
1608 ubi_err("bad attaching information about volume %d", av->vol_id);
1609 ubi_dump_av(av);
1610 ubi_dump_vid_hdr(vidh);
1611
1612out:
1613 dump_stack();
1614 return -EINVAL;
1615}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-25 08:54:45 -0500