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
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
59 #include <linux/crc32.h>
60 #include <linux/err.h>
61 #include <linux/slab.h>
62 #include <asm/div64.h>
65 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
66 static void paranoid_vtbl_check(const struct ubi_device *ubi);
68 #define paranoid_vtbl_check(ubi)
71 /* Empty volume table record */
72 static struct ubi_vtbl_record empty_vtbl_record;
75 * ubi_change_vtbl_record - change volume table record.
76 * @ubi: UBI device description object
77 * @idx: table index to change
78 * @vtbl_rec: new volume table record
80 * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty
81 * volume table record is written. The caller does not have to calculate CRC of
82 * the record as it is done by this function. Returns zero in case of success
83 * and a negative error code in case of failure.
85 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
86 struct ubi_vtbl_record *vtbl_rec)
90 struct ubi_volume *layout_vol;
92 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
93 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
96 vtbl_rec = &empty_vtbl_record;
98 crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC);
99 vtbl_rec->crc = cpu_to_be32(crc);
102 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record));
103 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
104 err = ubi_eba_unmap_leb(ubi, layout_vol, i);
108 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
109 ubi->vtbl_size, UBI_LONGTERM);
114 paranoid_vtbl_check(ubi);
119 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
120 * @ubi: UBI device description object
121 * @rename_list: list of &struct ubi_rename_entry objects
123 * This function re-names multiple volumes specified in @req in the volume
124 * table. Returns zero in case of success and a negative error code in case of
127 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
128 struct list_head *rename_list)
131 struct ubi_rename_entry *re;
132 struct ubi_volume *layout_vol;
134 list_for_each_entry(re, rename_list, list) {
136 struct ubi_volume *vol = re->desc->vol;
137 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
140 memcpy(vtbl_rec, &empty_vtbl_record,
141 sizeof(struct ubi_vtbl_record));
145 vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
146 memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
147 memset(vtbl_rec->name + re->new_name_len, 0,
148 UBI_VOL_NAME_MAX + 1 - re->new_name_len);
149 crc = crc32(UBI_CRC32_INIT, vtbl_rec,
150 UBI_VTBL_RECORD_SIZE_CRC);
151 vtbl_rec->crc = cpu_to_be32(crc);
154 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
155 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
156 err = ubi_eba_unmap_leb(ubi, layout_vol, i);
160 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
161 ubi->vtbl_size, UBI_LONGTERM);
170 * vtbl_check - check if volume table is not corrupted and sensible.
171 * @ubi: UBI device description object
172 * @vtbl: volume table
174 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect,
175 * and %-EINVAL if it contains inconsistent data.
177 static int vtbl_check(const struct ubi_device *ubi,
178 const struct ubi_vtbl_record *vtbl)
180 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
185 for (i = 0; i < ubi->vtbl_slots; i++) {
188 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
189 alignment = be32_to_cpu(vtbl[i].alignment);
190 data_pad = be32_to_cpu(vtbl[i].data_pad);
191 upd_marker = vtbl[i].upd_marker;
192 vol_type = vtbl[i].vol_type;
193 name_len = be16_to_cpu(vtbl[i].name_len);
194 name = &vtbl[i].name[0];
196 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC);
197 if (be32_to_cpu(vtbl[i].crc) != crc) {
198 ubi_err("bad CRC at record %u: %#08x, not %#08x",
199 i, crc, be32_to_cpu(vtbl[i].crc));
200 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
204 if (reserved_pebs == 0) {
205 if (memcmp(&vtbl[i], &empty_vtbl_record,
206 UBI_VTBL_RECORD_SIZE)) {
213 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
219 if (alignment > ubi->leb_size || alignment == 0) {
224 n = alignment & (ubi->min_io_size - 1);
225 if (alignment != 1 && n) {
230 n = ubi->leb_size % alignment;
232 dbg_err("bad data_pad, has to be %d", n);
237 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
242 if (upd_marker != 0 && upd_marker != 1) {
247 if (reserved_pebs > ubi->good_peb_count) {
248 dbg_err("too large reserved_pebs %d, good PEBs %d",
249 reserved_pebs, ubi->good_peb_count);
254 if (name_len > UBI_VOL_NAME_MAX) {
259 if (name[0] == '\0') {
264 if (name_len != strnlen(name, name_len + 1)) {
270 /* Checks that all names are unique */
271 for (i = 0; i < ubi->vtbl_slots - 1; i++) {
272 for (n = i + 1; n < ubi->vtbl_slots; n++) {
273 int len1 = be16_to_cpu(vtbl[i].name_len);
274 int len2 = be16_to_cpu(vtbl[n].name_len);
276 if (len1 > 0 && len1 == len2 &&
277 !strncmp(vtbl[i].name, vtbl[n].name, len1)) {
278 ubi_err("volumes %d and %d have the same name"
279 " \"%s\"", i, n, vtbl[i].name);
280 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
281 ubi_dbg_dump_vtbl_record(&vtbl[n], n);
290 ubi_err("volume table check failed: record %d, error %d", i, err);
291 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
296 * create_vtbl - create a copy of volume table.
297 * @ubi: UBI device description object
298 * @si: scanning information
299 * @copy: number of the volume table copy
300 * @vtbl: contents of the volume table
302 * This function returns zero in case of success and a negative error code in
305 static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
306 int copy, void *vtbl)
309 static struct ubi_vid_hdr *vid_hdr;
310 struct ubi_scan_volume *sv;
311 struct ubi_scan_leb *new_seb, *old_seb = NULL;
313 ubi_msg("create volume table (copy #%d)", copy + 1);
315 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
320 * Check if there is a logical eraseblock which would have to contain
321 * this volume table copy was found during scanning. It has to be wiped
324 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
326 old_seb = ubi_scan_find_seb(sv, copy);
329 new_seb = ubi_scan_get_free_peb(ubi, si);
330 if (IS_ERR(new_seb)) {
331 err = PTR_ERR(new_seb);
335 vid_hdr->vol_type = UBI_VID_DYNAMIC;
336 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
337 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
338 vid_hdr->data_size = vid_hdr->used_ebs =
339 vid_hdr->data_pad = cpu_to_be32(0);
340 vid_hdr->lnum = cpu_to_be32(copy);
341 vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum);
343 /* The EC header is already there, write the VID header */
344 err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
348 /* Write the layout volume contents */
349 err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size);
354 * And add it to the scanning information. Don't delete the old
355 * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'.
357 err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec,
360 ubi_free_vid_hdr(ubi, vid_hdr);
364 if (err == -EIO && ++tries <= 5) {
366 * Probably this physical eraseblock went bad, try to pick
369 list_add_tail(&new_seb->u.list, &si->corr);
374 ubi_free_vid_hdr(ubi, vid_hdr);
380 * process_lvol - process the layout volume.
381 * @ubi: UBI device description object
382 * @si: scanning information
383 * @sv: layout volume scanning information
385 * This function is responsible for reading the layout volume, ensuring it is
386 * not corrupted, and recovering from corruptions if needed. Returns volume
387 * table in case of success and a negative error code in case of failure.
389 static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
390 struct ubi_scan_info *si,
391 struct ubi_scan_volume *sv)
395 struct ubi_scan_leb *seb;
396 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL };
397 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1};
400 * UBI goes through the following steps when it changes the layout
403 * b. write new data to LEB 0;
405 * d. write new data to LEB 1.
407 * Before the change, both LEBs contain the same data.
409 * Due to unclean reboots, the contents of LEB 0 may be lost, but there
410 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not.
411 * Similarly, LEB 1 may be lost, but there should be LEB 0. And
412 * finally, unclean reboots may result in a situation when neither LEB
413 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB
414 * 0 contains more recent information.
416 * So the plan is to first check LEB 0. Then
417 * a. if LEB 0 is OK, it must be containing the most recent data; then
418 * we compare it with LEB 1, and if they are different, we copy LEB
420 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1
424 dbg_gen("check layout volume");
426 /* Read both LEB 0 and LEB 1 into memory */
427 ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
428 leb[seb->lnum] = vmalloc(ubi->vtbl_size);
429 if (!leb[seb->lnum]) {
433 memset(leb[seb->lnum], 0, ubi->vtbl_size);
435 err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
437 if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
439 * Scrub the PEB later. Note, -EBADMSG indicates an
440 * uncorrectable ECC error, but we have our own CRC and
441 * the data will be checked later. If the data is OK,
442 * the PEB will be scrubbed (because we set
443 * seb->scrub). If the data is not OK, the contents of
444 * the PEB will be recovered from the second copy, and
445 * seb->scrub will be cleared in
446 * 'ubi_scan_add_used()'.
455 leb_corrupted[0] = vtbl_check(ubi, leb[0]);
456 if (leb_corrupted[0] < 0)
460 if (!leb_corrupted[0]) {
463 leb_corrupted[1] = memcmp(leb[0], leb[1],
465 if (leb_corrupted[1]) {
466 ubi_warn("volume table copy #2 is corrupted");
467 err = create_vtbl(ubi, si, 1, leb[0]);
470 ubi_msg("volume table was restored");
473 /* Both LEB 1 and LEB 2 are OK and consistent */
477 /* LEB 0 is corrupted or does not exist */
479 leb_corrupted[1] = vtbl_check(ubi, leb[1]);
480 if (leb_corrupted[1] < 0)
483 if (leb_corrupted[1]) {
484 /* Both LEB 0 and LEB 1 are corrupted */
485 ubi_err("both volume tables are corrupted");
489 ubi_warn("volume table copy #1 is corrupted");
490 err = create_vtbl(ubi, si, 0, leb[1]);
493 ubi_msg("volume table was restored");
506 * create_empty_lvol - create empty layout volume.
507 * @ubi: UBI device description object
508 * @si: scanning information
510 * This function returns volume table contents in case of success and a
511 * negative error code in case of failure.
513 static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi,
514 struct ubi_scan_info *si)
517 struct ubi_vtbl_record *vtbl;
519 vtbl = vmalloc(ubi->vtbl_size);
521 return ERR_PTR(-ENOMEM);
522 memset(vtbl, 0, ubi->vtbl_size);
524 for (i = 0; i < ubi->vtbl_slots; i++)
525 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE);
527 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
530 err = create_vtbl(ubi, si, i, vtbl);
541 * init_volumes - initialize volume information for existing volumes.
542 * @ubi: UBI device description object
543 * @si: scanning information
544 * @vtbl: volume table
546 * This function allocates volume description objects for existing volumes.
547 * Returns zero in case of success and a negative error code in case of
550 static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
551 const struct ubi_vtbl_record *vtbl)
553 int i, reserved_pebs = 0;
554 struct ubi_scan_volume *sv;
555 struct ubi_volume *vol;
557 for (i = 0; i < ubi->vtbl_slots; i++) {
560 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0)
561 continue; /* Empty record */
563 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
567 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
568 vol->alignment = be32_to_cpu(vtbl[i].alignment);
569 vol->data_pad = be32_to_cpu(vtbl[i].data_pad);
570 vol->upd_marker = vtbl[i].upd_marker;
571 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ?
572 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
573 vol->name_len = be16_to_cpu(vtbl[i].name_len);
574 vol->usable_leb_size = ubi->leb_size - vol->data_pad;
575 memcpy(vol->name, vtbl[i].name, vol->name_len);
576 vol->name[vol->name_len] = '\0';
579 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
580 /* Auto re-size flag may be set only for one volume */
581 if (ubi->autoresize_vol_id != -1) {
582 ubi_err("more than one auto-resize volume (%d "
583 "and %d)", ubi->autoresize_vol_id, i);
588 ubi->autoresize_vol_id = i;
591 ubi_assert(!ubi->volumes[i]);
592 ubi->volumes[i] = vol;
595 reserved_pebs += vol->reserved_pebs;
598 * In case of dynamic volume UBI knows nothing about how many
599 * data is stored there. So assume the whole volume is used.
601 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
602 vol->used_ebs = vol->reserved_pebs;
603 vol->last_eb_bytes = vol->usable_leb_size;
605 (long long)vol->used_ebs * vol->usable_leb_size;
609 /* Static volumes only */
610 sv = ubi_scan_find_sv(si, i);
613 * No eraseblocks belonging to this volume found. We
614 * don't actually know whether this static volume is
615 * completely corrupted or just contains no data. And
616 * we cannot know this as long as data size is not
617 * stored on flash. So we just assume the volume is
618 * empty. FIXME: this should be handled.
623 if (sv->leb_count != sv->used_ebs) {
625 * We found a static volume which misses several
626 * eraseblocks. Treat it as corrupted.
628 ubi_warn("static volume %d misses %d LEBs - corrupted",
629 sv->vol_id, sv->used_ebs - sv->leb_count);
634 vol->used_ebs = sv->used_ebs;
636 (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
637 vol->used_bytes += sv->last_data_size;
638 vol->last_eb_bytes = sv->last_data_size;
641 /* And add the layout volume */
642 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
646 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS;
648 vol->vol_type = UBI_DYNAMIC_VOLUME;
649 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1;
650 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1);
651 vol->usable_leb_size = ubi->leb_size;
652 vol->used_ebs = vol->reserved_pebs;
653 vol->last_eb_bytes = vol->reserved_pebs;
655 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
656 vol->vol_id = UBI_LAYOUT_VOLUME_ID;
659 ubi_assert(!ubi->volumes[i]);
660 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol;
661 reserved_pebs += vol->reserved_pebs;
665 if (reserved_pebs > ubi->avail_pebs)
666 ubi_err("not enough PEBs, required %d, available %d",
667 reserved_pebs, ubi->avail_pebs);
668 ubi->rsvd_pebs += reserved_pebs;
669 ubi->avail_pebs -= reserved_pebs;
675 * check_sv - check volume scanning information.
676 * @vol: UBI volume description object
677 * @sv: volume scanning information
679 * This function returns zero if the volume scanning information is consistent
680 * to the data read from the volume tabla, and %-EINVAL if not.
682 static int check_sv(const struct ubi_volume *vol,
683 const struct ubi_scan_volume *sv)
687 if (sv->highest_lnum >= vol->reserved_pebs) {
691 if (sv->leb_count > vol->reserved_pebs) {
695 if (sv->vol_type != vol->vol_type) {
699 if (sv->used_ebs > vol->reserved_pebs) {
703 if (sv->data_pad != vol->data_pad) {
710 ubi_err("bad scanning information, error %d", err);
712 ubi_dbg_dump_vol_info(vol);
717 * check_scanning_info - check that scanning information.
718 * @ubi: UBI device description object
719 * @si: scanning information
721 * Even though we protect on-flash data by CRC checksums, we still don't trust
722 * the media. This function ensures that scanning information is consistent to
723 * the information read from the volume table. Returns zero if the scanning
724 * information is OK and %-EINVAL if it is not.
726 static int check_scanning_info(const struct ubi_device *ubi,
727 struct ubi_scan_info *si)
730 struct ubi_scan_volume *sv;
731 struct ubi_volume *vol;
733 if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) {
734 ubi_err("scanning found %d volumes, maximum is %d + %d",
735 si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots);
739 if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
740 si->highest_vol_id < UBI_INTERNAL_VOL_START) {
741 ubi_err("too large volume ID %d found by scanning",
746 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
749 sv = ubi_scan_find_sv(si, i);
750 vol = ubi->volumes[i];
753 ubi_scan_rm_volume(si, sv);
757 if (vol->reserved_pebs == 0) {
758 ubi_assert(i < ubi->vtbl_slots);
764 * During scanning we found a volume which does not
765 * exist according to the information in the volume
766 * table. This must have happened due to an unclean
767 * reboot while the volume was being removed. Discard
770 ubi_msg("finish volume %d removal", sv->vol_id);
771 ubi_scan_rm_volume(si, sv);
773 err = check_sv(vol, sv);
783 * ubi_read_volume_table - read the volume table.
784 * @ubi: UBI device description object
785 * @si: scanning information
787 * This function reads volume table, checks it, recover from errors if needed,
788 * or creates it if needed. Returns zero in case of success and a negative
789 * error code in case of failure.
791 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
794 struct ubi_scan_volume *sv;
796 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b);
799 * The number of supported volumes is limited by the eraseblock size
800 * and by the UBI_MAX_VOLUMES constant.
802 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE;
803 if (ubi->vtbl_slots > UBI_MAX_VOLUMES)
804 ubi->vtbl_slots = UBI_MAX_VOLUMES;
806 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
807 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
809 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
812 * No logical eraseblocks belonging to the layout volume were
813 * found. This could mean that the flash is just empty. In
814 * this case we create empty layout volume.
816 * But if flash is not empty this must be a corruption or the
817 * MTD device just contains garbage.
820 ubi->vtbl = create_empty_lvol(ubi, si);
821 if (IS_ERR(ubi->vtbl))
822 return PTR_ERR(ubi->vtbl);
824 ubi_err("the layout volume was not found");
828 if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) {
829 /* This must not happen with proper UBI images */
830 dbg_err("too many LEBs (%d) in layout volume",
835 ubi->vtbl = process_lvol(ubi, si, sv);
836 if (IS_ERR(ubi->vtbl))
837 return PTR_ERR(ubi->vtbl);
840 ubi->avail_pebs = ubi->good_peb_count;
843 * The layout volume is OK, initialize the corresponding in-RAM data
846 err = init_volumes(ubi, si, ubi->vtbl);
851 * Make sure that the scanning information is consistent to the
852 * information stored in the volume table.
854 err = check_scanning_info(ubi, si);
862 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
863 kfree(ubi->volumes[i]);
864 ubi->volumes[i] = NULL;
869 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
872 * paranoid_vtbl_check - check volume table.
873 * @ubi: UBI device description object
875 static void paranoid_vtbl_check(const struct ubi_device *ubi)
877 if (vtbl_check(ubi, ubi->vtbl)) {
878 ubi_err("paranoid check failed");
883 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */