1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2006, 2007
5 *
6 * Author: Artem Bityutskiy (Битюцкий Артём)
7 */
8
9 /*
10 * This file includes volume table manipulation code. The volume table is an
11 * on-flash table containing volume meta-data like name, number of reserved
12 * physical eraseblocks, type, etc. The volume table is stored in the so-called
13 * "layout volume".
14 *
15 * The layout volume is an internal volume which is organized as follows. It
16 * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical
17 * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each
18 * other. This redundancy guarantees robustness to unclean reboots. The volume
19 * table is basically an array of volume table records. Each record contains
20 * full information about the volume and protected by a CRC checksum. Note,
21 * nowadays we use the atomic LEB change operation when updating the volume
22 * table, so we do not really need 2 LEBs anymore, but we preserve the older
23 * design for the backward compatibility reasons.
24 *
25 * When the volume table is changed, it is first changed in RAM. Then LEB 0 is
26 * erased, and the updated volume table is written back to LEB 0. Then same for
27 * LEB 1. This scheme guarantees recoverability from unclean reboots.
28 *
29 * In this UBI implementation the on-flash volume table does not contain any
30 * information about how much data static volumes contain.
31 *
32 * But it would still be beneficial to store this information in the volume
33 * table. For example, suppose we have a static volume X, and all its physical
34 * eraseblocks became bad for some reasons. Suppose we are attaching the
35 * corresponding MTD device, for some reason we find no logical eraseblocks
36 * corresponding to the volume X. According to the volume table volume X does
37 * exist. So we don't know whether it is just empty or all its physical
38 * eraseblocks went bad. So we cannot alarm the user properly.
39 *
40 * The volume table also stores so-called "update marker", which is used for
41 * volume updates. Before updating the volume, the update marker is set, and
42 * after the update operation is finished, the update marker is cleared. So if
43 * the update operation was interrupted (e.g. by an unclean reboot) - the
44 * update marker is still there and we know that the volume's contents is
45 * damaged.
46 */
47
48 #ifndef __UBOOT__
49 #include <log.h>
50 #include <dm/devres.h>
51 #include <linux/crc32.h>
52 #include <linux/err.h>
53 #include <linux/slab.h>
54 #include <asm/div64.h>
55 #include <u-boot/crc.h>
56 #else
57 #include <ubi_uboot.h>
58 #include <linux/bug.h>
59 #endif
60
61 #include <linux/err.h>
62 #include "ubi.h"
63
64 static void self_vtbl_check(const struct ubi_device *ubi);
65
66 /* Empty volume table record */
67 static struct ubi_vtbl_record empty_vtbl_record;
68
69 /**
70 * ubi_update_layout_vol - helper for updatting layout volumes on flash
71 * @ubi: UBI device description object
72 */
ubi_update_layout_vol(struct ubi_device * ubi)73 static int ubi_update_layout_vol(struct ubi_device *ubi)
74 {
75 struct ubi_volume *layout_vol;
76 int i, err;
77
78 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
79 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
80 err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl,
81 ubi->vtbl_size);
82 if (err)
83 return err;
84 }
85
86 return 0;
87 }
88
89 /**
90 * ubi_change_vtbl_record - change volume table record.
91 * @ubi: UBI device description object
92 * @idx: table index to change
93 * @vtbl_rec: new volume table record
94 *
95 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty
96 * volume table record is written. The caller does not have to calculate CRC of
97 * the record as it is done by this function. Returns zero in case of success
98 * and a negative error code in case of failure.
99 */
ubi_change_vtbl_record(struct ubi_device * ubi,int idx,struct ubi_vtbl_record * vtbl_rec)100 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
101 struct ubi_vtbl_record *vtbl_rec)
102 {
103 int err;
104 uint32_t crc;
105
106 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
107
108 if (!vtbl_rec)
109 vtbl_rec = &empty_vtbl_record;
110 else {
111 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC);
112 vtbl_rec->crc = cpu_to_be32(crc);
113 }
114
115 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record));
116 err = ubi_update_layout_vol(ubi);
117
118 self_vtbl_check(ubi);
119 return err ? err : 0;
120 }
121
122 /**
123 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
124 * @ubi: UBI device description object
125 * @rename_list: list of &struct ubi_rename_entry objects
126 *
127 * This function re-names multiple volumes specified in @req in the volume
128 * table. Returns zero in case of success and a negative error code in case of
129 * failure.
130 */
ubi_vtbl_rename_volumes(struct ubi_device * ubi,struct list_head * rename_list)131 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
132 struct list_head *rename_list)
133 {
134 struct ubi_rename_entry *re;
135
136 list_for_each_entry(re, rename_list, list) {
137 uint32_t crc;
138 struct ubi_volume *vol = re->desc->vol;
139 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
140
141 if (re->remove) {
142 memcpy(vtbl_rec, &empty_vtbl_record,
143 sizeof(struct ubi_vtbl_record));
144 continue;
145 }
146
147 vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
148 memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
149 memset(vtbl_rec->name + re->new_name_len, 0,
150 UBI_VOL_NAME_MAX + 1 - re->new_name_len);
151 crc = crc32(UBI_CRC32_INIT, vtbl_rec,
152 UBI_VTBL_RECORD_SIZE_CRC);
153 vtbl_rec->crc = cpu_to_be32(crc);
154 }
155
156 return ubi_update_layout_vol(ubi);
157 }
158
159 /**
160 * vtbl_check - check if volume table is not corrupted and sensible.
161 * @ubi: UBI device description object
162 * @vtbl: volume table
163 *
164 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect,
165 * and %-EINVAL if it contains inconsistent data.
166 */
vtbl_check(const struct ubi_device * ubi,const struct ubi_vtbl_record * vtbl)167 static int vtbl_check(const struct ubi_device *ubi,
168 const struct ubi_vtbl_record *vtbl)
169 {
170 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
171 int upd_marker, err;
172 uint32_t crc;
173 const char *name;
174
175 for (i = 0; i < ubi->vtbl_slots; i++) {
176 cond_resched();
177
178 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
179 alignment = be32_to_cpu(vtbl[i].alignment);
180 data_pad = be32_to_cpu(vtbl[i].data_pad);
181 upd_marker = vtbl[i].upd_marker;
182 vol_type = vtbl[i].vol_type;
183 name_len = be16_to_cpu(vtbl[i].name_len);
184 name = &vtbl[i].name[0];
185
186 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC);
187 if (be32_to_cpu(vtbl[i].crc) != crc) {
188 ubi_err(ubi, "bad CRC at record %u: %#08x, not %#08x",
189 i, crc, be32_to_cpu(vtbl[i].crc));
190 ubi_dump_vtbl_record(&vtbl[i], i);
191 return 1;
192 }
193
194 if (reserved_pebs == 0) {
195 if (memcmp(&vtbl[i], &empty_vtbl_record,
196 UBI_VTBL_RECORD_SIZE)) {
197 err = 2;
198 goto bad;
199 }
200 continue;
201 }
202
203 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
204 name_len < 0) {
205 err = 3;
206 goto bad;
207 }
208
209 if (alignment > ubi->leb_size || alignment == 0) {
210 err = 4;
211 goto bad;
212 }
213
214 n = alignment & (ubi->min_io_size - 1);
215 if (alignment != 1 && n) {
216 err = 5;
217 goto bad;
218 }
219
220 n = ubi->leb_size % alignment;
221 if (data_pad != n) {
222 ubi_err(ubi, "bad data_pad, has to be %d", n);
223 err = 6;
224 goto bad;
225 }
226
227 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
228 err = 7;
229 goto bad;
230 }
231
232 if (upd_marker != 0 && upd_marker != 1) {
233 err = 8;
234 goto bad;
235 }
236
237 if (reserved_pebs > ubi->good_peb_count) {
238 ubi_err(ubi, "too large reserved_pebs %d, good PEBs %d",
239 reserved_pebs, ubi->good_peb_count);
240 err = 9;
241 goto bad;
242 }
243
244 if (name_len > UBI_VOL_NAME_MAX) {
245 err = 10;
246 goto bad;
247 }
248
249 if (name[0] == '\0') {
250 err = 11;
251 goto bad;
252 }
253
254 if (name_len != strnlen(name, name_len + 1)) {
255 err = 12;
256 goto bad;
257 }
258 }
259
260 /* Checks that all names are unique */
261 for (i = 0; i < ubi->vtbl_slots - 1; i++) {
262 for (n = i + 1; n < ubi->vtbl_slots; n++) {
263 int len1 = be16_to_cpu(vtbl[i].name_len);
264 int len2 = be16_to_cpu(vtbl[n].name_len);
265
266 if (len1 > 0 && len1 == len2 &&
267 #ifndef __UBOOT__
268 !strncmp(vtbl[i].name, vtbl[n].name, len1)) {
269 #else
270 !strncmp((char *)vtbl[i].name, vtbl[n].name, len1)) {
271 #endif
272 ubi_err(ubi, "volumes %d and %d have the same name \"%s\"",
273 i, n, vtbl[i].name);
274 ubi_dump_vtbl_record(&vtbl[i], i);
275 ubi_dump_vtbl_record(&vtbl[n], n);
276 return -EINVAL;
277 }
278 }
279 }
280
281 return 0;
282
283 bad:
284 ubi_err(ubi, "volume table check failed: record %d, error %d", i, err);
285 ubi_dump_vtbl_record(&vtbl[i], i);
286 return -EINVAL;
287 }
288
289 /**
290 * create_vtbl - create a copy of volume table.
291 * @ubi: UBI device description object
292 * @ai: attaching information
293 * @copy: number of the volume table copy
294 * @vtbl: contents of the volume table
295 *
296 * This function returns zero in case of success and a negative error code in
297 * case of failure.
298 */
299 static int create_vtbl(struct ubi_device *ubi, struct ubi_attach_info *ai,
300 int copy, void *vtbl)
301 {
302 int err, tries = 0;
303 struct ubi_vid_hdr *vid_hdr;
304 struct ubi_ainf_peb *new_aeb;
305
306 dbg_gen("create volume table (copy #%d)", copy + 1);
307
308 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
309 if (!vid_hdr)
310 return -ENOMEM;
311
312 retry:
313 new_aeb = ubi_early_get_peb(ubi, ai);
314 if (IS_ERR(new_aeb)) {
315 err = PTR_ERR(new_aeb);
316 goto out_free;
317 }
318
319 vid_hdr->vol_type = UBI_LAYOUT_VOLUME_TYPE;
320 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
321 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
322 vid_hdr->data_size = vid_hdr->used_ebs =
323 vid_hdr->data_pad = cpu_to_be32(0);
324 vid_hdr->lnum = cpu_to_be32(copy);
325 vid_hdr->sqnum = cpu_to_be64(++ai->max_sqnum);
326
327 /* The EC header is already there, write the VID header */
328 err = ubi_io_write_vid_hdr(ubi, new_aeb->pnum, vid_hdr);
329 if (err)
330 goto write_error;
331
332 /* Write the layout volume contents */
333 err = ubi_io_write_data(ubi, vtbl, new_aeb->pnum, 0, ubi->vtbl_size);
334 if (err)
335 goto write_error;
336
337 /*
338 * And add it to the attaching information. Don't delete the old version
339 * of this LEB as it will be deleted and freed in 'ubi_add_to_av()'.
340 */
341 err = ubi_add_to_av(ubi, ai, new_aeb->pnum, new_aeb->ec, vid_hdr, 0);
342 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
343 ubi_free_vid_hdr(ubi, vid_hdr);
344 return err;
345
346 write_error:
347 if (err == -EIO && ++tries <= 5) {
348 /*
349 * Probably this physical eraseblock went bad, try to pick
350 * another one.
351 */
352 list_add(&new_aeb->u.list, &ai->erase);
353 goto retry;
354 }
355 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
356 out_free:
357 ubi_free_vid_hdr(ubi, vid_hdr);
358 return err;
359
360 }
361
362 /**
363 * process_lvol - process the layout volume.
364 * @ubi: UBI device description object
365 * @ai: attaching information
366 * @av: layout volume attaching information
367 *
368 * This function is responsible for reading the layout volume, ensuring it is
369 * not corrupted, and recovering from corruptions if needed. Returns volume
370 * table in case of success and a negative error code in case of failure.
371 */
372 static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
373 struct ubi_attach_info *ai,
374 struct ubi_ainf_volume *av)
375 {
376 int err;
377 struct rb_node *rb;
378 struct ubi_ainf_peb *aeb;
379 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL };
380 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1};
381
382 /*
383 * UBI goes through the following steps when it changes the layout
384 * volume:
385 * a. erase LEB 0;
386 * b. write new data to LEB 0;
387 * c. erase LEB 1;
388 * d. write new data to LEB 1.
389 *
390 * Before the change, both LEBs contain the same data.
391 *
392 * Due to unclean reboots, the contents of LEB 0 may be lost, but there
393 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not.
394 * Similarly, LEB 1 may be lost, but there should be LEB 0. And
395 * finally, unclean reboots may result in a situation when neither LEB
396 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB
397 * 0 contains more recent information.
398 *
399 * So the plan is to first check LEB 0. Then
400 * a. if LEB 0 is OK, it must be containing the most recent data; then
401 * we compare it with LEB 1, and if they are different, we copy LEB
402 * 0 to LEB 1;
403 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1
404 * to LEB 0.
405 */
406
407 dbg_gen("check layout volume");
408
409 /* Read both LEB 0 and LEB 1 into memory */
410 ubi_rb_for_each_entry(rb, aeb, &av->root, u.rb) {
411 leb[aeb->lnum] = vzalloc(ubi->vtbl_size);
412 if (!leb[aeb->lnum]) {
413 err = -ENOMEM;
414 goto out_free;
415 }
416
417 err = ubi_io_read_data(ubi, leb[aeb->lnum], aeb->pnum, 0,
418 ubi->vtbl_size);
419 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err))
420 /*
421 * Scrub the PEB later. Note, -EBADMSG indicates an
422 * uncorrectable ECC error, but we have our own CRC and
423 * the data will be checked later. If the data is OK,
424 * the PEB will be scrubbed (because we set
425 * aeb->scrub). If the data is not OK, the contents of
426 * the PEB will be recovered from the second copy, and
427 * aeb->scrub will be cleared in
428 * 'ubi_add_to_av()'.
429 */
430 aeb->scrub = 1;
431 else if (err)
432 goto out_free;
433 }
434
435 err = -EINVAL;
436 if (leb[0]) {
437 leb_corrupted[0] = vtbl_check(ubi, leb[0]);
438 if (leb_corrupted[0] < 0)
439 goto out_free;
440 }
441
442 if (!leb_corrupted[0]) {
443 /* LEB 0 is OK */
444 if (leb[1])
445 leb_corrupted[1] = memcmp(leb[0], leb[1],
446 ubi->vtbl_size);
447 if (leb_corrupted[1]) {
448 ubi_warn(ubi, "volume table copy #2 is corrupted");
449 err = create_vtbl(ubi, ai, 1, leb[0]);
450 if (err)
451 goto out_free;
452 ubi_msg(ubi, "volume table was restored");
453 }
454
455 /* Both LEB 1 and LEB 2 are OK and consistent */
456 vfree(leb[1]);
457 return leb[0];
458 } else {
459 /* LEB 0 is corrupted or does not exist */
460 if (leb[1]) {
461 leb_corrupted[1] = vtbl_check(ubi, leb[1]);
462 if (leb_corrupted[1] < 0)
463 goto out_free;
464 }
465 if (leb_corrupted[1]) {
466 /* Both LEB 0 and LEB 1 are corrupted */
467 ubi_err(ubi, "both volume tables are corrupted");
468 goto out_free;
469 }
470
471 ubi_warn(ubi, "volume table copy #1 is corrupted");
472 err = create_vtbl(ubi, ai, 0, leb[1]);
473 if (err)
474 goto out_free;
475 ubi_msg(ubi, "volume table was restored");
476
477 vfree(leb[0]);
478 return leb[1];
479 }
480
481 out_free:
482 vfree(leb[0]);
483 vfree(leb[1]);
484 return ERR_PTR(err);
485 }
486
487 /**
488 * create_empty_lvol - create empty layout volume.
489 * @ubi: UBI device description object
490 * @ai: attaching information
491 *
492 * This function returns volume table contents in case of success and a
493 * negative error code in case of failure.
494 */
495 static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi,
496 struct ubi_attach_info *ai)
497 {
498 int i;
499 struct ubi_vtbl_record *vtbl;
500
501 vtbl = vzalloc(ubi->vtbl_size);
502 if (!vtbl)
503 return ERR_PTR(-ENOMEM);
504
505 for (i = 0; i < ubi->vtbl_slots; i++)
506 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE);
507
508 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
509 int err;
510
511 err = create_vtbl(ubi, ai, i, vtbl);
512 if (err) {
513 vfree(vtbl);
514 return ERR_PTR(err);
515 }
516 }
517
518 return vtbl;
519 }
520
521 /**
522 * init_volumes - initialize volume information for existing volumes.
523 * @ubi: UBI device description object
524 * @ai: scanning information
525 * @vtbl: volume table
526 *
527 * This function allocates volume description objects for existing volumes.
528 * Returns zero in case of success and a negative error code in case of
529 * failure.
530 */
531 static int init_volumes(struct ubi_device *ubi,
532 const struct ubi_attach_info *ai,
533 const struct ubi_vtbl_record *vtbl)
534 {
535 int i, reserved_pebs = 0;
536 struct ubi_ainf_volume *av;
537 struct ubi_volume *vol;
538
539 for (i = 0; i < ubi->vtbl_slots; i++) {
540 cond_resched();
541
542 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0)
543 continue; /* Empty record */
544
545 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
546 if (!vol)
547 return -ENOMEM;
548
549 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
550 vol->alignment = be32_to_cpu(vtbl[i].alignment);
551 vol->data_pad = be32_to_cpu(vtbl[i].data_pad);
552 vol->upd_marker = vtbl[i].upd_marker;
553 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ?
554 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
555 vol->name_len = be16_to_cpu(vtbl[i].name_len);
556 vol->usable_leb_size = ubi->leb_size - vol->data_pad;
557 memcpy(vol->name, vtbl[i].name, vol->name_len);
558 vol->name[vol->name_len] = '\0';
559 vol->vol_id = i;
560
561 if (vtbl[i].flags & UBI_VTBL_SKIP_CRC_CHECK_FLG)
562 vol->skip_check = 1;
563
564 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
565 /* Auto re-size flag may be set only for one volume */
566 if (ubi->autoresize_vol_id != -1) {
567 ubi_err(ubi, "more than one auto-resize volume (%d and %d)",
568 ubi->autoresize_vol_id, i);
569 kfree(vol);
570 return -EINVAL;
571 }
572
573 ubi->autoresize_vol_id = i;
574 }
575
576 ubi_assert(!ubi->volumes[i]);
577 ubi->volumes[i] = vol;
578 ubi->vol_count += 1;
579 vol->ubi = ubi;
580 reserved_pebs += vol->reserved_pebs;
581
582 /*
583 * In case of dynamic volume UBI knows nothing about how many
584 * data is stored there. So assume the whole volume is used.
585 */
586 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
587 vol->used_ebs = vol->reserved_pebs;
588 vol->last_eb_bytes = vol->usable_leb_size;
589 vol->used_bytes =
590 (long long)vol->used_ebs * vol->usable_leb_size;
591 continue;
592 }
593
594 /* Static volumes only */
595 av = ubi_find_av(ai, i);
596 if (!av || !av->leb_count) {
597 /*
598 * No eraseblocks belonging to this volume found. We
599 * don't actually know whether this static volume is
600 * completely corrupted or just contains no data. And
601 * we cannot know this as long as data size is not
602 * stored on flash. So we just assume the volume is
603 * empty. FIXME: this should be handled.
604 */
605 continue;
606 }
607
608 if (av->leb_count != av->used_ebs) {
609 /*
610 * We found a static volume which misses several
611 * eraseblocks. Treat it as corrupted.
612 */
613 ubi_warn(ubi, "static volume %d misses %d LEBs - corrupted",
614 av->vol_id, av->used_ebs - av->leb_count);
615 vol->corrupted = 1;
616 continue;
617 }
618
619 vol->used_ebs = av->used_ebs;
620 vol->used_bytes =
621 (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
622 vol->used_bytes += av->last_data_size;
623 vol->last_eb_bytes = av->last_data_size;
624 }
625
626 /* And add the layout volume */
627 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
628 if (!vol)
629 return -ENOMEM;
630
631 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS;
632 vol->alignment = UBI_LAYOUT_VOLUME_ALIGN;
633 vol->vol_type = UBI_DYNAMIC_VOLUME;
634 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1;
635 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1);
636 vol->usable_leb_size = ubi->leb_size;
637 vol->used_ebs = vol->reserved_pebs;
638 vol->last_eb_bytes = vol->reserved_pebs;
639 vol->used_bytes =
640 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
641 vol->vol_id = UBI_LAYOUT_VOLUME_ID;
642 vol->ref_count = 1;
643
644 ubi_assert(!ubi->volumes[i]);
645 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol;
646 reserved_pebs += vol->reserved_pebs;
647 ubi->vol_count += 1;
648 vol->ubi = ubi;
649
650 if (reserved_pebs > ubi->avail_pebs) {
651 ubi_err(ubi, "not enough PEBs, required %d, available %d",
652 reserved_pebs, ubi->avail_pebs);
653 if (ubi->corr_peb_count)
654 ubi_err(ubi, "%d PEBs are corrupted and not used",
655 ubi->corr_peb_count);
656 }
657 ubi->rsvd_pebs += reserved_pebs;
658 ubi->avail_pebs -= reserved_pebs;
659
660 return 0;
661 }
662
663 /**
664 * check_av - check volume attaching information.
665 * @vol: UBI volume description object
666 * @av: volume attaching information
667 *
668 * This function returns zero if the volume attaching information is consistent
669 * to the data read from the volume tabla, and %-EINVAL if not.
670 */
671 static int check_av(const struct ubi_volume *vol,
672 const struct ubi_ainf_volume *av)
673 {
674 int err;
675
676 if (av->highest_lnum >= vol->reserved_pebs) {
677 err = 1;
678 goto bad;
679 }
680 if (av->leb_count > vol->reserved_pebs) {
681 err = 2;
682 goto bad;
683 }
684 if (av->vol_type != vol->vol_type) {
685 err = 3;
686 goto bad;
687 }
688 if (av->used_ebs > vol->reserved_pebs) {
689 err = 4;
690 goto bad;
691 }
692 if (av->data_pad != vol->data_pad) {
693 err = 5;
694 goto bad;
695 }
696 return 0;
697
698 bad:
699 ubi_err(vol->ubi, "bad attaching information, error %d", err);
700 ubi_dump_av(av);
701 ubi_dump_vol_info(vol);
702 return -EINVAL;
703 }
704
705 /**
706 * check_attaching_info - check that attaching information.
707 * @ubi: UBI device description object
708 * @ai: attaching information
709 *
710 * Even though we protect on-flash data by CRC checksums, we still don't trust
711 * the media. This function ensures that attaching information is consistent to
712 * the information read from the volume table. Returns zero if the attaching
713 * information is OK and %-EINVAL if it is not.
714 */
715 static int check_attaching_info(const struct ubi_device *ubi,
716 struct ubi_attach_info *ai)
717 {
718 int err, i;
719 struct ubi_ainf_volume *av;
720 struct ubi_volume *vol;
721
722 if (ai->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) {
723 ubi_err(ubi, "found %d volumes while attaching, maximum is %d + %d",
724 ai->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots);
725 return -EINVAL;
726 }
727
728 if (ai->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
729 ai->highest_vol_id < UBI_INTERNAL_VOL_START) {
730 ubi_err(ubi, "too large volume ID %d found",
731 ai->highest_vol_id);
732 return -EINVAL;
733 }
734
735 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
736 cond_resched();
737
738 av = ubi_find_av(ai, i);
739 vol = ubi->volumes[i];
740 if (!vol) {
741 if (av)
742 ubi_remove_av(ai, av);
743 continue;
744 }
745
746 if (vol->reserved_pebs == 0) {
747 ubi_assert(i < ubi->vtbl_slots);
748
749 if (!av)
750 continue;
751
752 /*
753 * During attaching we found a volume which does not
754 * exist according to the information in the volume
755 * table. This must have happened due to an unclean
756 * reboot while the volume was being removed. Discard
757 * these eraseblocks.
758 */
759 ubi_msg(ubi, "finish volume %d removal", av->vol_id);
760 ubi_remove_av(ai, av);
761 } else if (av) {
762 err = check_av(vol, av);
763 if (err)
764 return err;
765 }
766 }
767
768 return 0;
769 }
770
771 /**
772 * ubi_read_volume_table - read the volume table.
773 * @ubi: UBI device description object
774 * @ai: attaching information
775 *
776 * This function reads volume table, checks it, recover from errors if needed,
777 * or creates it if needed. Returns zero in case of success and a negative
778 * error code in case of failure.
779 */
780 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai)
781 {
782 int i, err;
783 struct ubi_ainf_volume *av;
784
785 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b);
786
787 /*
788 * The number of supported volumes is limited by the eraseblock size
789 * and by the UBI_MAX_VOLUMES constant.
790 */
791 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE;
792 if (ubi->vtbl_slots > UBI_MAX_VOLUMES)
793 ubi->vtbl_slots = UBI_MAX_VOLUMES;
794
795 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
796 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
797
798 av = ubi_find_av(ai, UBI_LAYOUT_VOLUME_ID);
799 if (!av) {
800 /*
801 * No logical eraseblocks belonging to the layout volume were
802 * found. This could mean that the flash is just empty. In
803 * this case we create empty layout volume.
804 *
805 * But if flash is not empty this must be a corruption or the
806 * MTD device just contains garbage.
807 */
808 if (ai->is_empty) {
809 ubi->vtbl = create_empty_lvol(ubi, ai);
810 if (IS_ERR(ubi->vtbl))
811 return PTR_ERR(ubi->vtbl);
812 } else {
813 ubi_err(ubi, "the layout volume was not found");
814 return -EINVAL;
815 }
816 } else {
817 if (av->leb_count > UBI_LAYOUT_VOLUME_EBS) {
818 /* This must not happen with proper UBI images */
819 ubi_err(ubi, "too many LEBs (%d) in layout volume",
820 av->leb_count);
821 return -EINVAL;
822 }
823
824 ubi->vtbl = process_lvol(ubi, ai, av);
825 if (IS_ERR(ubi->vtbl))
826 return PTR_ERR(ubi->vtbl);
827 }
828
829 ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count;
830
831 /*
832 * The layout volume is OK, initialize the corresponding in-RAM data
833 * structures.
834 */
835 err = init_volumes(ubi, ai, ubi->vtbl);
836 if (err)
837 goto out_free;
838
839 /*
840 * Make sure that the attaching information is consistent to the
841 * information stored in the volume table.
842 */
843 err = check_attaching_info(ubi, ai);
844 if (err)
845 goto out_free;
846
847 return 0;
848
849 out_free:
850 vfree(ubi->vtbl);
851 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
852 kfree(ubi->volumes[i]);
853 ubi->volumes[i] = NULL;
854 }
855 return err;
856 }
857
858 /**
859 * self_vtbl_check - check volume table.
860 * @ubi: UBI device description object
861 */
862 static void self_vtbl_check(const struct ubi_device *ubi)
863 {
864 if (!ubi_dbg_chk_gen(ubi))
865 return;
866
867 if (vtbl_check(ubi, ubi->vtbl)) {
868 ubi_err(ubi, "self-check failed");
869 BUG();
870 }
871 }
872