Linux 2.6.26-rc1
[cris-mirror.git] / drivers / mtd / ubi / vtbl.c
blobaf36b12be27871ddefd1c34a0d17f95483042343
1 /*
2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём)
23 * This file includes volume table manipulation code. The volume table is an
24 * on-flash table containing volume meta-data like name, number of reserved
25 * physical eraseblocks, type, etc. The volume table is stored in the so-called
26 * "layout volume".
28 * The layout volume is an internal volume which is organized as follows. It
29 * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical
30 * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each
31 * other. This redundancy guarantees robustness to unclean reboots. The volume
32 * table is basically an array of volume table records. Each record contains
33 * full information about the volume and protected by a CRC checksum.
35 * The volume table is changed, it is first changed in RAM. Then LEB 0 is
36 * erased, and the updated volume table is written back to LEB 0. Then same for
37 * LEB 1. This scheme guarantees recoverability from unclean reboots.
39 * In this UBI implementation the on-flash volume table does not contain any
40 * information about how many data static volumes contain. This information may
41 * be found from the scanning data.
43 * But it would still be beneficial to store this information in the volume
44 * table. For example, suppose we have a static volume X, and all its physical
45 * eraseblocks became bad for some reasons. Suppose we are attaching the
46 * corresponding MTD device, the scanning has found no logical eraseblocks
47 * corresponding to the volume X. According to the volume table volume X does
48 * exist. So we don't know whether it is just empty or all its physical
49 * eraseblocks went bad. So we cannot alarm the user about this corruption.
51 * The volume table also stores so-called "update marker", which is used for
52 * volume updates. Before updating the volume, the update marker is set, and
53 * after the update operation is finished, the update marker is cleared. So if
54 * the update operation was interrupted (e.g. by an unclean reboot) - the
55 * update marker is still there and we know that the volume's contents is
56 * damaged.
59 #include <linux/crc32.h>
60 #include <linux/err.h>
61 #include <asm/div64.h>
62 #include "ubi.h"
64 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
65 static void paranoid_vtbl_check(const struct ubi_device *ubi);
66 #else
67 #define paranoid_vtbl_check(ubi)
68 #endif
70 /* Empty volume table record */
71 static struct ubi_vtbl_record empty_vtbl_record;
73 /**
74 * ubi_change_vtbl_record - change volume table record.
75 * @ubi: UBI device description object
76 * @idx: table index to change
77 * @vtbl_rec: new volume table record
79 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty
80 * volume table record is written. The caller does not have to calculate CRC of
81 * the record as it is done by this function. Returns zero in case of success
82 * and a negative error code in case of failure.
84 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
85 struct ubi_vtbl_record *vtbl_rec)
87 int i, err;
88 uint32_t crc;
89 struct ubi_volume *layout_vol;
91 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
92 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
94 if (!vtbl_rec)
95 vtbl_rec = &empty_vtbl_record;
96 else {
97 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC);
98 vtbl_rec->crc = cpu_to_be32(crc);
101 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record));
102 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
103 err = ubi_eba_unmap_leb(ubi, layout_vol, i);
104 if (err)
105 return err;
107 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
108 ubi->vtbl_size, UBI_LONGTERM);
109 if (err)
110 return err;
113 paranoid_vtbl_check(ubi);
114 return 0;
118 * vtbl_check - check if volume table is not corrupted and contains sensible
119 * data.
120 * @ubi: UBI device description object
121 * @vtbl: volume table
123 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect,
124 * and %-EINVAL if it contains inconsistent data.
126 static int vtbl_check(const struct ubi_device *ubi,
127 const struct ubi_vtbl_record *vtbl)
129 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
130 int upd_marker;
131 uint32_t crc;
132 const char *name;
134 for (i = 0; i < ubi->vtbl_slots; i++) {
135 cond_resched();
137 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
138 alignment = be32_to_cpu(vtbl[i].alignment);
139 data_pad = be32_to_cpu(vtbl[i].data_pad);
140 upd_marker = vtbl[i].upd_marker;
141 vol_type = vtbl[i].vol_type;
142 name_len = be16_to_cpu(vtbl[i].name_len);
143 name = &vtbl[i].name[0];
145 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC);
146 if (be32_to_cpu(vtbl[i].crc) != crc) {
147 ubi_err("bad CRC at record %u: %#08x, not %#08x",
148 i, crc, be32_to_cpu(vtbl[i].crc));
149 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
150 return 1;
153 if (reserved_pebs == 0) {
154 if (memcmp(&vtbl[i], &empty_vtbl_record,
155 UBI_VTBL_RECORD_SIZE)) {
156 dbg_err("bad empty record");
157 goto bad;
159 continue;
162 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
163 name_len < 0) {
164 dbg_err("negative values");
165 goto bad;
168 if (alignment > ubi->leb_size || alignment == 0) {
169 dbg_err("bad alignment");
170 goto bad;
173 n = alignment % ubi->min_io_size;
174 if (alignment != 1 && n) {
175 dbg_err("alignment is not multiple of min I/O unit");
176 goto bad;
179 n = ubi->leb_size % alignment;
180 if (data_pad != n) {
181 dbg_err("bad data_pad, has to be %d", n);
182 goto bad;
185 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
186 dbg_err("bad vol_type");
187 goto bad;
190 if (upd_marker != 0 && upd_marker != 1) {
191 dbg_err("bad upd_marker");
192 goto bad;
195 if (reserved_pebs > ubi->good_peb_count) {
196 dbg_err("too large reserved_pebs, good PEBs %d",
197 ubi->good_peb_count);
198 goto bad;
201 if (name_len > UBI_VOL_NAME_MAX) {
202 dbg_err("too long volume name, max %d",
203 UBI_VOL_NAME_MAX);
204 goto bad;
207 if (name[0] == '\0') {
208 dbg_err("NULL volume name");
209 goto bad;
212 if (name_len != strnlen(name, name_len + 1)) {
213 dbg_err("bad name_len");
214 goto bad;
218 /* Checks that all names are unique */
219 for (i = 0; i < ubi->vtbl_slots - 1; i++) {
220 for (n = i + 1; n < ubi->vtbl_slots; n++) {
221 int len1 = be16_to_cpu(vtbl[i].name_len);
222 int len2 = be16_to_cpu(vtbl[n].name_len);
224 if (len1 > 0 && len1 == len2 &&
225 !strncmp(vtbl[i].name, vtbl[n].name, len1)) {
226 ubi_err("volumes %d and %d have the same name"
227 " \"%s\"", i, n, vtbl[i].name);
228 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
229 ubi_dbg_dump_vtbl_record(&vtbl[n], n);
230 return -EINVAL;
235 return 0;
237 bad:
238 ubi_err("volume table check failed, record %d", i);
239 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
240 return -EINVAL;
244 * create_vtbl - create a copy of volume table.
245 * @ubi: UBI device description object
246 * @si: scanning information
247 * @copy: number of the volume table copy
248 * @vtbl: contents of the volume table
250 * This function returns zero in case of success and a negative error code in
251 * case of failure.
253 static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
254 int copy, void *vtbl)
256 int err, tries = 0;
257 static struct ubi_vid_hdr *vid_hdr;
258 struct ubi_scan_volume *sv;
259 struct ubi_scan_leb *new_seb, *old_seb = NULL;
261 ubi_msg("create volume table (copy #%d)", copy + 1);
263 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
264 if (!vid_hdr)
265 return -ENOMEM;
268 * Check if there is a logical eraseblock which would have to contain
269 * this volume table copy was found during scanning. It has to be wiped
270 * out.
272 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
273 if (sv)
274 old_seb = ubi_scan_find_seb(sv, copy);
276 retry:
277 new_seb = ubi_scan_get_free_peb(ubi, si);
278 if (IS_ERR(new_seb)) {
279 err = PTR_ERR(new_seb);
280 goto out_free;
283 vid_hdr->vol_type = UBI_VID_DYNAMIC;
284 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
285 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
286 vid_hdr->data_size = vid_hdr->used_ebs =
287 vid_hdr->data_pad = cpu_to_be32(0);
288 vid_hdr->lnum = cpu_to_be32(copy);
289 vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum);
290 vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0);
292 /* The EC header is already there, write the VID header */
293 err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
294 if (err)
295 goto write_error;
297 /* Write the layout volume contents */
298 err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size);
299 if (err)
300 goto write_error;
303 * And add it to the scanning information. Don't delete the old
304 * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'.
306 err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec,
307 vid_hdr, 0);
308 kfree(new_seb);
309 ubi_free_vid_hdr(ubi, vid_hdr);
310 return err;
312 write_error:
313 if (err == -EIO && ++tries <= 5) {
315 * Probably this physical eraseblock went bad, try to pick
316 * another one.
318 list_add_tail(&new_seb->u.list, &si->corr);
319 goto retry;
321 kfree(new_seb);
322 out_free:
323 ubi_free_vid_hdr(ubi, vid_hdr);
324 return err;
329 * process_lvol - process the layout volume.
330 * @ubi: UBI device description object
331 * @si: scanning information
332 * @sv: layout volume scanning information
334 * This function is responsible for reading the layout volume, ensuring it is
335 * not corrupted, and recovering from corruptions if needed. Returns volume
336 * table in case of success and a negative error code in case of failure.
338 static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
339 struct ubi_scan_info *si,
340 struct ubi_scan_volume *sv)
342 int err;
343 struct rb_node *rb;
344 struct ubi_scan_leb *seb;
345 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL };
346 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1};
349 * UBI goes through the following steps when it changes the layout
350 * volume:
351 * a. erase LEB 0;
352 * b. write new data to LEB 0;
353 * c. erase LEB 1;
354 * d. write new data to LEB 1.
356 * Before the change, both LEBs contain the same data.
358 * Due to unclean reboots, the contents of LEB 0 may be lost, but there
359 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not.
360 * Similarly, LEB 1 may be lost, but there should be LEB 0. And
361 * finally, unclean reboots may result in a situation when neither LEB
362 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB
363 * 0 contains more recent information.
365 * So the plan is to first check LEB 0. Then
366 * a. if LEB 0 is OK, it must be containing the most resent data; then
367 * we compare it with LEB 1, and if they are different, we copy LEB
368 * 0 to LEB 1;
369 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1
370 * to LEB 0.
373 dbg_msg("check layout volume");
375 /* Read both LEB 0 and LEB 1 into memory */
376 ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
377 leb[seb->lnum] = vmalloc(ubi->vtbl_size);
378 if (!leb[seb->lnum]) {
379 err = -ENOMEM;
380 goto out_free;
382 memset(leb[seb->lnum], 0, ubi->vtbl_size);
384 err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
385 ubi->vtbl_size);
386 if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
387 /* Scrub the PEB later */
388 seb->scrub = 1;
389 else if (err)
390 goto out_free;
393 err = -EINVAL;
394 if (leb[0]) {
395 leb_corrupted[0] = vtbl_check(ubi, leb[0]);
396 if (leb_corrupted[0] < 0)
397 goto out_free;
400 if (!leb_corrupted[0]) {
401 /* LEB 0 is OK */
402 if (leb[1])
403 leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size);
404 if (leb_corrupted[1]) {
405 ubi_warn("volume table copy #2 is corrupted");
406 err = create_vtbl(ubi, si, 1, leb[0]);
407 if (err)
408 goto out_free;
409 ubi_msg("volume table was restored");
412 /* Both LEB 1 and LEB 2 are OK and consistent */
413 vfree(leb[1]);
414 return leb[0];
415 } else {
416 /* LEB 0 is corrupted or does not exist */
417 if (leb[1]) {
418 leb_corrupted[1] = vtbl_check(ubi, leb[1]);
419 if (leb_corrupted[1] < 0)
420 goto out_free;
422 if (leb_corrupted[1]) {
423 /* Both LEB 0 and LEB 1 are corrupted */
424 ubi_err("both volume tables are corrupted");
425 goto out_free;
428 ubi_warn("volume table copy #1 is corrupted");
429 err = create_vtbl(ubi, si, 0, leb[1]);
430 if (err)
431 goto out_free;
432 ubi_msg("volume table was restored");
434 vfree(leb[0]);
435 return leb[1];
438 out_free:
439 vfree(leb[0]);
440 vfree(leb[1]);
441 return ERR_PTR(err);
445 * create_empty_lvol - create empty layout volume.
446 * @ubi: UBI device description object
447 * @si: scanning information
449 * This function returns volume table contents in case of success and a
450 * negative error code in case of failure.
452 static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi,
453 struct ubi_scan_info *si)
455 int i;
456 struct ubi_vtbl_record *vtbl;
458 vtbl = vmalloc(ubi->vtbl_size);
459 if (!vtbl)
460 return ERR_PTR(-ENOMEM);
461 memset(vtbl, 0, ubi->vtbl_size);
463 for (i = 0; i < ubi->vtbl_slots; i++)
464 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE);
466 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
467 int err;
469 err = create_vtbl(ubi, si, i, vtbl);
470 if (err) {
471 vfree(vtbl);
472 return ERR_PTR(err);
476 return vtbl;
480 * init_volumes - initialize volume information for existing volumes.
481 * @ubi: UBI device description object
482 * @si: scanning information
483 * @vtbl: volume table
485 * This function allocates volume description objects for existing volumes.
486 * Returns zero in case of success and a negative error code in case of
487 * failure.
489 static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
490 const struct ubi_vtbl_record *vtbl)
492 int i, reserved_pebs = 0;
493 struct ubi_scan_volume *sv;
494 struct ubi_volume *vol;
496 for (i = 0; i < ubi->vtbl_slots; i++) {
497 cond_resched();
499 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0)
500 continue; /* Empty record */
502 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
503 if (!vol)
504 return -ENOMEM;
506 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
507 vol->alignment = be32_to_cpu(vtbl[i].alignment);
508 vol->data_pad = be32_to_cpu(vtbl[i].data_pad);
509 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ?
510 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
511 vol->name_len = be16_to_cpu(vtbl[i].name_len);
512 vol->usable_leb_size = ubi->leb_size - vol->data_pad;
513 memcpy(vol->name, vtbl[i].name, vol->name_len);
514 vol->name[vol->name_len] = '\0';
515 vol->vol_id = i;
517 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
518 /* Auto re-size flag may be set only for one volume */
519 if (ubi->autoresize_vol_id != -1) {
520 ubi_err("more then one auto-resize volume (%d "
521 "and %d)", ubi->autoresize_vol_id, i);
522 kfree(vol);
523 return -EINVAL;
526 ubi->autoresize_vol_id = i;
529 ubi_assert(!ubi->volumes[i]);
530 ubi->volumes[i] = vol;
531 ubi->vol_count += 1;
532 vol->ubi = ubi;
533 reserved_pebs += vol->reserved_pebs;
536 * In case of dynamic volume UBI knows nothing about how many
537 * data is stored there. So assume the whole volume is used.
539 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
540 vol->used_ebs = vol->reserved_pebs;
541 vol->last_eb_bytes = vol->usable_leb_size;
542 vol->used_bytes =
543 (long long)vol->used_ebs * vol->usable_leb_size;
544 continue;
547 /* Static volumes only */
548 sv = ubi_scan_find_sv(si, i);
549 if (!sv) {
551 * No eraseblocks belonging to this volume found. We
552 * don't actually know whether this static volume is
553 * completely corrupted or just contains no data. And
554 * we cannot know this as long as data size is not
555 * stored on flash. So we just assume the volume is
556 * empty. FIXME: this should be handled.
558 continue;
561 if (sv->leb_count != sv->used_ebs) {
563 * We found a static volume which misses several
564 * eraseblocks. Treat it as corrupted.
566 ubi_warn("static volume %d misses %d LEBs - corrupted",
567 sv->vol_id, sv->used_ebs - sv->leb_count);
568 vol->corrupted = 1;
569 continue;
572 vol->used_ebs = sv->used_ebs;
573 vol->used_bytes =
574 (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
575 vol->used_bytes += sv->last_data_size;
576 vol->last_eb_bytes = sv->last_data_size;
579 /* And add the layout volume */
580 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
581 if (!vol)
582 return -ENOMEM;
584 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS;
585 vol->alignment = 1;
586 vol->vol_type = UBI_DYNAMIC_VOLUME;
587 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1;
588 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1);
589 vol->usable_leb_size = ubi->leb_size;
590 vol->used_ebs = vol->reserved_pebs;
591 vol->last_eb_bytes = vol->reserved_pebs;
592 vol->used_bytes =
593 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
594 vol->vol_id = UBI_LAYOUT_VOLUME_ID;
595 vol->ref_count = 1;
597 ubi_assert(!ubi->volumes[i]);
598 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol;
599 reserved_pebs += vol->reserved_pebs;
600 ubi->vol_count += 1;
601 vol->ubi = ubi;
603 if (reserved_pebs > ubi->avail_pebs)
604 ubi_err("not enough PEBs, required %d, available %d",
605 reserved_pebs, ubi->avail_pebs);
606 ubi->rsvd_pebs += reserved_pebs;
607 ubi->avail_pebs -= reserved_pebs;
609 return 0;
613 * check_sv - check volume scanning information.
614 * @vol: UBI volume description object
615 * @sv: volume scanning information
617 * This function returns zero if the volume scanning information is consistent
618 * to the data read from the volume tabla, and %-EINVAL if not.
620 static int check_sv(const struct ubi_volume *vol,
621 const struct ubi_scan_volume *sv)
623 if (sv->highest_lnum >= vol->reserved_pebs) {
624 dbg_err("bad highest_lnum");
625 goto bad;
627 if (sv->leb_count > vol->reserved_pebs) {
628 dbg_err("bad leb_count");
629 goto bad;
631 if (sv->vol_type != vol->vol_type) {
632 dbg_err("bad vol_type");
633 goto bad;
635 if (sv->used_ebs > vol->reserved_pebs) {
636 dbg_err("bad used_ebs");
637 goto bad;
639 if (sv->data_pad != vol->data_pad) {
640 dbg_err("bad data_pad");
641 goto bad;
643 return 0;
645 bad:
646 ubi_err("bad scanning information");
647 ubi_dbg_dump_sv(sv);
648 ubi_dbg_dump_vol_info(vol);
649 return -EINVAL;
653 * check_scanning_info - check that scanning information.
654 * @ubi: UBI device description object
655 * @si: scanning information
657 * Even though we protect on-flash data by CRC checksums, we still don't trust
658 * the media. This function ensures that scanning information is consistent to
659 * the information read from the volume table. Returns zero if the scanning
660 * information is OK and %-EINVAL if it is not.
662 static int check_scanning_info(const struct ubi_device *ubi,
663 struct ubi_scan_info *si)
665 int err, i;
666 struct ubi_scan_volume *sv;
667 struct ubi_volume *vol;
669 if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) {
670 ubi_err("scanning found %d volumes, maximum is %d + %d",
671 si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots);
672 return -EINVAL;
675 if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&&
676 si->highest_vol_id < UBI_INTERNAL_VOL_START) {
677 ubi_err("too large volume ID %d found by scanning",
678 si->highest_vol_id);
679 return -EINVAL;
683 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
684 cond_resched();
686 sv = ubi_scan_find_sv(si, i);
687 vol = ubi->volumes[i];
688 if (!vol) {
689 if (sv)
690 ubi_scan_rm_volume(si, sv);
691 continue;
694 if (vol->reserved_pebs == 0) {
695 ubi_assert(i < ubi->vtbl_slots);
697 if (!sv)
698 continue;
701 * During scanning we found a volume which does not
702 * exist according to the information in the volume
703 * table. This must have happened due to an unclean
704 * reboot while the volume was being removed. Discard
705 * these eraseblocks.
707 ubi_msg("finish volume %d removal", sv->vol_id);
708 ubi_scan_rm_volume(si, sv);
709 } else if (sv) {
710 err = check_sv(vol, sv);
711 if (err)
712 return err;
716 return 0;
720 * ubi_read_volume_table - read volume table.
721 * information.
722 * @ubi: UBI device description object
723 * @si: scanning information
725 * This function reads volume table, checks it, recover from errors if needed,
726 * or creates it if needed. Returns zero in case of success and a negative
727 * error code in case of failure.
729 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
731 int i, err;
732 struct ubi_scan_volume *sv;
734 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b);
737 * The number of supported volumes is limited by the eraseblock size
738 * and by the UBI_MAX_VOLUMES constant.
740 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE;
741 if (ubi->vtbl_slots > UBI_MAX_VOLUMES)
742 ubi->vtbl_slots = UBI_MAX_VOLUMES;
744 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
745 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
747 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
748 if (!sv) {
750 * No logical eraseblocks belonging to the layout volume were
751 * found. This could mean that the flash is just empty. In
752 * this case we create empty layout volume.
754 * But if flash is not empty this must be a corruption or the
755 * MTD device just contains garbage.
757 if (si->is_empty) {
758 ubi->vtbl = create_empty_lvol(ubi, si);
759 if (IS_ERR(ubi->vtbl))
760 return PTR_ERR(ubi->vtbl);
761 } else {
762 ubi_err("the layout volume was not found");
763 return -EINVAL;
765 } else {
766 if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) {
767 /* This must not happen with proper UBI images */
768 dbg_err("too many LEBs (%d) in layout volume",
769 sv->leb_count);
770 return -EINVAL;
773 ubi->vtbl = process_lvol(ubi, si, sv);
774 if (IS_ERR(ubi->vtbl))
775 return PTR_ERR(ubi->vtbl);
778 ubi->avail_pebs = ubi->good_peb_count;
781 * The layout volume is OK, initialize the corresponding in-RAM data
782 * structures.
784 err = init_volumes(ubi, si, ubi->vtbl);
785 if (err)
786 goto out_free;
789 * Get sure that the scanning information is consistent to the
790 * information stored in the volume table.
792 err = check_scanning_info(ubi, si);
793 if (err)
794 goto out_free;
796 return 0;
798 out_free:
799 vfree(ubi->vtbl);
800 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++)
801 if (ubi->volumes[i]) {
802 kfree(ubi->volumes[i]);
803 ubi->volumes[i] = NULL;
805 return err;
808 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
811 * paranoid_vtbl_check - check volume table.
812 * @ubi: UBI device description object
814 static void paranoid_vtbl_check(const struct ubi_device *ubi)
816 if (vtbl_check(ubi, ubi->vtbl)) {
817 ubi_err("paranoid check failed");
818 BUG();
822 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */