blob: 40044028d6824e217a6e5f5cbe9e1ea232a291f8 [file] [log] [blame]
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +04001/*
2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
4 *
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.
9 *
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.
14 *
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
18 *
19 * Author: Artem Bityutskiy (Битюцкий Артём)
20 */
21
22/*
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".
27 *
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.
34 *
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.
38 *
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.
42 *
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.
50 *
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.
57 */
58
59#include <linux/crc32.h>
60#include <linux/err.h>
61#include <asm/div64.h>
62#include "ubi.h"
63
64#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
65static void paranoid_vtbl_check(const struct ubi_device *ubi);
66#else
67#define paranoid_vtbl_check(ubi)
68#endif
69
70/* Empty volume table record */
71static struct ubi_vtbl_record empty_vtbl_record;
72
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
78 *
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.
83 */
84int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
85 struct ubi_vtbl_record *vtbl_rec)
86{
87 int i, err;
88 uint32_t crc;
Artem Bityutskiy89b96b62007-12-16 20:00:38 +020089 struct ubi_volume *layout_vol;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040090
91 ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
Artem Bityutskiy91f2d532008-01-24 11:23:23 +020092 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040093
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);
Christoph Hellwig3261ebd2007-05-21 17:41:46 +030098 vtbl_rec->crc = cpu_to_be32(crc);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040099 }
100
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400101 memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record));
102 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
Artem Bityutskiy89b96b62007-12-16 20:00:38 +0200103 err = ubi_eba_unmap_leb(ubi, layout_vol, i);
Artem Bityutskiycae0a772007-12-17 12:46:48 +0200104 if (err)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400105 return err;
Artem Bityutskiycae0a772007-12-17 12:46:48 +0200106
Artem Bityutskiy89b96b62007-12-16 20:00:38 +0200107 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400108 ubi->vtbl_size, UBI_LONGTERM);
Artem Bityutskiycae0a772007-12-17 12:46:48 +0200109 if (err)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400110 return err;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400111 }
112
113 paranoid_vtbl_check(ubi);
Artem Bityutskiy6dc4a872008-02-01 13:48:49 +0200114 return 0;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400115}
116
117/**
Artem Bityutskiyf40ac9c2008-07-13 21:47:47 +0300118 * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
119 * @ubi: UBI device description object
Artem Bityutskiyebaaf1a2008-07-18 13:34:32 +0300120 * @rename_list: list of &struct ubi_rename_entry objects
Artem Bityutskiyf40ac9c2008-07-13 21:47:47 +0300121 *
122 * This function re-names multiple volumes specified in @req in the volume
123 * table. Returns zero in case of success and a negative error code in case of
124 * failure.
125 */
126int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
127 struct list_head *rename_list)
128{
129 int i, err;
130 struct ubi_rename_entry *re;
131 struct ubi_volume *layout_vol;
132
133 list_for_each_entry(re, rename_list, list) {
134 uint32_t crc;
135 struct ubi_volume *vol = re->desc->vol;
136 struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
137
138 if (re->remove) {
139 memcpy(vtbl_rec, &empty_vtbl_record,
140 sizeof(struct ubi_vtbl_record));
141 continue;
142 }
143
144 vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
145 memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
146 memset(vtbl_rec->name + re->new_name_len, 0,
147 UBI_VOL_NAME_MAX + 1 - re->new_name_len);
148 crc = crc32(UBI_CRC32_INIT, vtbl_rec,
149 UBI_VTBL_RECORD_SIZE_CRC);
150 vtbl_rec->crc = cpu_to_be32(crc);
151 }
152
153 layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
154 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
155 err = ubi_eba_unmap_leb(ubi, layout_vol, i);
156 if (err)
157 return err;
158
159 err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
160 ubi->vtbl_size, UBI_LONGTERM);
161 if (err)
162 return err;
163 }
164
165 return 0;
166}
167
168/**
Artem Bityutskiyebaaf1a2008-07-18 13:34:32 +0300169 * vtbl_check - check if volume table is not corrupted and sensible.
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400170 * @ubi: UBI device description object
171 * @vtbl: volume table
172 *
173 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect,
174 * and %-EINVAL if it contains inconsistent data.
175 */
176static int vtbl_check(const struct ubi_device *ubi,
177 const struct ubi_vtbl_record *vtbl)
178{
179 int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300180 int upd_marker, err;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400181 uint32_t crc;
182 const char *name;
183
184 for (i = 0; i < ubi->vtbl_slots; i++) {
185 cond_resched();
186
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300187 reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
188 alignment = be32_to_cpu(vtbl[i].alignment);
189 data_pad = be32_to_cpu(vtbl[i].data_pad);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400190 upd_marker = vtbl[i].upd_marker;
191 vol_type = vtbl[i].vol_type;
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300192 name_len = be16_to_cpu(vtbl[i].name_len);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400193 name = &vtbl[i].name[0];
194
195 crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC);
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300196 if (be32_to_cpu(vtbl[i].crc) != crc) {
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400197 ubi_err("bad CRC at record %u: %#08x, not %#08x",
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300198 i, crc, be32_to_cpu(vtbl[i].crc));
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400199 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
200 return 1;
201 }
202
203 if (reserved_pebs == 0) {
204 if (memcmp(&vtbl[i], &empty_vtbl_record,
205 UBI_VTBL_RECORD_SIZE)) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300206 err = 2;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400207 goto bad;
208 }
209 continue;
210 }
211
212 if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
213 name_len < 0) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300214 err = 3;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400215 goto bad;
216 }
217
218 if (alignment > ubi->leb_size || alignment == 0) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300219 err = 4;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400220 goto bad;
221 }
222
Kyungmin Parkcadb40c2008-05-22 10:32:18 +0900223 n = alignment & (ubi->min_io_size - 1);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400224 if (alignment != 1 && n) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300225 err = 5;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400226 goto bad;
227 }
228
229 n = ubi->leb_size % alignment;
230 if (data_pad != n) {
231 dbg_err("bad data_pad, has to be %d", n);
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300232 err = 6;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400233 goto bad;
234 }
235
236 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300237 err = 7;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400238 goto bad;
239 }
240
241 if (upd_marker != 0 && upd_marker != 1) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300242 err = 8;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400243 goto bad;
244 }
245
246 if (reserved_pebs > ubi->good_peb_count) {
Deepak Saxena762a9f22008-10-08 12:56:24 -0700247 dbg_err("too large reserved_pebs %d, good PEBs %d",
248 reserved_pebs, ubi->good_peb_count);
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300249 err = 9;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400250 goto bad;
251 }
252
253 if (name_len > UBI_VOL_NAME_MAX) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300254 err = 10;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400255 goto bad;
256 }
257
258 if (name[0] == '\0') {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300259 err = 11;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400260 goto bad;
261 }
262
263 if (name_len != strnlen(name, name_len + 1)) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300264 err = 12;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400265 goto bad;
266 }
267 }
268
269 /* Checks that all names are unique */
270 for (i = 0; i < ubi->vtbl_slots - 1; i++) {
271 for (n = i + 1; n < ubi->vtbl_slots; n++) {
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300272 int len1 = be16_to_cpu(vtbl[i].name_len);
273 int len2 = be16_to_cpu(vtbl[n].name_len);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400274
275 if (len1 > 0 && len1 == len2 &&
276 !strncmp(vtbl[i].name, vtbl[n].name, len1)) {
277 ubi_err("volumes %d and %d have the same name"
278 " \"%s\"", i, n, vtbl[i].name);
279 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
280 ubi_dbg_dump_vtbl_record(&vtbl[n], n);
281 return -EINVAL;
282 }
283 }
284 }
285
286 return 0;
287
288bad:
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300289 ubi_err("volume table check failed: record %d, error %d", i, err);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400290 ubi_dbg_dump_vtbl_record(&vtbl[i], i);
291 return -EINVAL;
292}
293
294/**
295 * create_vtbl - create a copy of volume table.
296 * @ubi: UBI device description object
297 * @si: scanning information
298 * @copy: number of the volume table copy
299 * @vtbl: contents of the volume table
300 *
301 * This function returns zero in case of success and a negative error code in
302 * case of failure.
303 */
Artem Bityutskiye88d6e102007-08-29 14:51:52 +0300304static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400305 int copy, void *vtbl)
306{
307 int err, tries = 0;
308 static struct ubi_vid_hdr *vid_hdr;
309 struct ubi_scan_volume *sv;
310 struct ubi_scan_leb *new_seb, *old_seb = NULL;
311
312 ubi_msg("create volume table (copy #%d)", copy + 1);
313
Artem Bityutskiy33818bb2007-08-28 21:29:32 +0300314 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400315 if (!vid_hdr)
316 return -ENOMEM;
317
318 /*
319 * Check if there is a logical eraseblock which would have to contain
320 * this volume table copy was found during scanning. It has to be wiped
321 * out.
322 */
Artem Bityutskiy91f2d532008-01-24 11:23:23 +0200323 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400324 if (sv)
325 old_seb = ubi_scan_find_seb(sv, copy);
326
327retry:
328 new_seb = ubi_scan_get_free_peb(ubi, si);
329 if (IS_ERR(new_seb)) {
330 err = PTR_ERR(new_seb);
331 goto out_free;
332 }
333
334 vid_hdr->vol_type = UBI_VID_DYNAMIC;
Artem Bityutskiy91f2d532008-01-24 11:23:23 +0200335 vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400336 vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
337 vid_hdr->data_size = vid_hdr->used_ebs =
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300338 vid_hdr->data_pad = cpu_to_be32(0);
339 vid_hdr->lnum = cpu_to_be32(copy);
340 vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400341
342 /* The EC header is already there, write the VID header */
343 err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
344 if (err)
345 goto write_error;
346
347 /* Write the layout volume contents */
348 err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size);
349 if (err)
350 goto write_error;
351
352 /*
353 * And add it to the scanning information. Don't delete the old
354 * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'.
355 */
356 err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec,
357 vid_hdr, 0);
358 kfree(new_seb);
359 ubi_free_vid_hdr(ubi, vid_hdr);
360 return err;
361
362write_error:
Artem Bityutskiy78d87c92007-05-05 11:24:02 +0300363 if (err == -EIO && ++tries <= 5) {
364 /*
365 * Probably this physical eraseblock went bad, try to pick
366 * another one.
367 */
368 list_add_tail(&new_seb->u.list, &si->corr);
Florin Malitac4e90ec2007-05-03 11:49:57 -0400369 goto retry;
Artem Bityutskiy78d87c92007-05-05 11:24:02 +0300370 }
371 kfree(new_seb);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400372out_free:
373 ubi_free_vid_hdr(ubi, vid_hdr);
374 return err;
375
376}
377
378/**
379 * process_lvol - process the layout volume.
380 * @ubi: UBI device description object
381 * @si: scanning information
382 * @sv: layout volume scanning information
383 *
384 * This function is responsible for reading the layout volume, ensuring it is
385 * not corrupted, and recovering from corruptions if needed. Returns volume
386 * table in case of success and a negative error code in case of failure.
387 */
Artem Bityutskiye88d6e102007-08-29 14:51:52 +0300388static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400389 struct ubi_scan_info *si,
390 struct ubi_scan_volume *sv)
391{
392 int err;
393 struct rb_node *rb;
394 struct ubi_scan_leb *seb;
395 struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL };
396 int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1};
397
398 /*
399 * UBI goes through the following steps when it changes the layout
400 * volume:
401 * a. erase LEB 0;
402 * b. write new data to LEB 0;
403 * c. erase LEB 1;
404 * d. write new data to LEB 1.
405 *
406 * Before the change, both LEBs contain the same data.
407 *
408 * Due to unclean reboots, the contents of LEB 0 may be lost, but there
409 * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not.
410 * Similarly, LEB 1 may be lost, but there should be LEB 0. And
411 * finally, unclean reboots may result in a situation when neither LEB
412 * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB
413 * 0 contains more recent information.
414 *
415 * So the plan is to first check LEB 0. Then
416 * a. if LEB 0 is OK, it must be containing the most resent data; then
417 * we compare it with LEB 1, and if they are different, we copy LEB
418 * 0 to LEB 1;
419 * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1
420 * to LEB 0.
421 */
422
Artem Bityutskiyc8566352008-07-16 17:40:22 +0300423 dbg_gen("check layout volume");
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400424
425 /* Read both LEB 0 and LEB 1 into memory */
426 ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300427 leb[seb->lnum] = vmalloc(ubi->vtbl_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400428 if (!leb[seb->lnum]) {
429 err = -ENOMEM;
430 goto out_free;
431 }
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300432 memset(leb[seb->lnum], 0, ubi->vtbl_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400433
434 err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
435 ubi->vtbl_size);
436 if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
Artem Bityutskiybeeea632008-05-20 09:54:02 +0300437 /*
438 * Scrub the PEB later. Note, -EBADMSG indicates an
439 * uncorrectable ECC error, but we have our own CRC and
440 * the data will be checked later. If the data is OK,
441 * the PEB will be scrubbed (because we set
442 * seb->scrub). If the data is not OK, the contents of
443 * the PEB will be recovered from the second copy, and
444 * seb->scrub will be cleared in
445 * 'ubi_scan_add_used()'.
446 */
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400447 seb->scrub = 1;
448 else if (err)
449 goto out_free;
450 }
451
452 err = -EINVAL;
453 if (leb[0]) {
454 leb_corrupted[0] = vtbl_check(ubi, leb[0]);
455 if (leb_corrupted[0] < 0)
456 goto out_free;
457 }
458
459 if (!leb_corrupted[0]) {
460 /* LEB 0 is OK */
461 if (leb[1])
Artem Bityutskiy9c9ec142008-07-18 13:19:52 +0300462 leb_corrupted[1] = memcmp(leb[0], leb[1],
463 ubi->vtbl_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400464 if (leb_corrupted[1]) {
465 ubi_warn("volume table copy #2 is corrupted");
466 err = create_vtbl(ubi, si, 1, leb[0]);
467 if (err)
468 goto out_free;
469 ubi_msg("volume table was restored");
470 }
471
472 /* Both LEB 1 and LEB 2 are OK and consistent */
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300473 vfree(leb[1]);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400474 return leb[0];
475 } else {
476 /* LEB 0 is corrupted or does not exist */
477 if (leb[1]) {
478 leb_corrupted[1] = vtbl_check(ubi, leb[1]);
479 if (leb_corrupted[1] < 0)
480 goto out_free;
481 }
482 if (leb_corrupted[1]) {
483 /* Both LEB 0 and LEB 1 are corrupted */
484 ubi_err("both volume tables are corrupted");
485 goto out_free;
486 }
487
488 ubi_warn("volume table copy #1 is corrupted");
489 err = create_vtbl(ubi, si, 0, leb[1]);
490 if (err)
491 goto out_free;
492 ubi_msg("volume table was restored");
493
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300494 vfree(leb[0]);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400495 return leb[1];
496 }
497
498out_free:
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300499 vfree(leb[0]);
500 vfree(leb[1]);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400501 return ERR_PTR(err);
502}
503
504/**
505 * create_empty_lvol - create empty layout volume.
506 * @ubi: UBI device description object
507 * @si: scanning information
508 *
509 * This function returns volume table contents in case of success and a
510 * negative error code in case of failure.
511 */
Artem Bityutskiye88d6e102007-08-29 14:51:52 +0300512static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400513 struct ubi_scan_info *si)
514{
515 int i;
516 struct ubi_vtbl_record *vtbl;
517
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300518 vtbl = vmalloc(ubi->vtbl_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400519 if (!vtbl)
520 return ERR_PTR(-ENOMEM);
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300521 memset(vtbl, 0, ubi->vtbl_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400522
523 for (i = 0; i < ubi->vtbl_slots; i++)
524 memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE);
525
526 for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
527 int err;
528
529 err = create_vtbl(ubi, si, i, vtbl);
530 if (err) {
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300531 vfree(vtbl);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400532 return ERR_PTR(err);
533 }
534 }
535
536 return vtbl;
537}
538
539/**
540 * init_volumes - initialize volume information for existing volumes.
541 * @ubi: UBI device description object
542 * @si: scanning information
543 * @vtbl: volume table
544 *
545 * This function allocates volume description objects for existing volumes.
546 * Returns zero in case of success and a negative error code in case of
547 * failure.
548 */
549static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
550 const struct ubi_vtbl_record *vtbl)
551{
552 int i, reserved_pebs = 0;
553 struct ubi_scan_volume *sv;
554 struct ubi_volume *vol;
555
556 for (i = 0; i < ubi->vtbl_slots; i++) {
557 cond_resched();
558
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300559 if (be32_to_cpu(vtbl[i].reserved_pebs) == 0)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400560 continue; /* Empty record */
561
562 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
563 if (!vol)
564 return -ENOMEM;
565
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300566 vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
567 vol->alignment = be32_to_cpu(vtbl[i].alignment);
568 vol->data_pad = be32_to_cpu(vtbl[i].data_pad);
Peter Hortonff998792010-01-05 11:14:36 +0000569 vol->upd_marker = vtbl[i].upd_marker;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400570 vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ?
571 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300572 vol->name_len = be16_to_cpu(vtbl[i].name_len);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400573 vol->usable_leb_size = ubi->leb_size - vol->data_pad;
574 memcpy(vol->name, vtbl[i].name, vol->name_len);
575 vol->name[vol->name_len] = '\0';
576 vol->vol_id = i;
577
Artem Bityutskiy4ccf8cf2008-01-16 15:44:24 +0200578 if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
579 /* Auto re-size flag may be set only for one volume */
580 if (ubi->autoresize_vol_id != -1) {
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200581 ubi_err("more than one auto-resize volume (%d "
Artem Bityutskiy4ccf8cf2008-01-16 15:44:24 +0200582 "and %d)", ubi->autoresize_vol_id, i);
Adrian Bunkf7f02832008-03-03 20:07:52 +0200583 kfree(vol);
Artem Bityutskiy4ccf8cf2008-01-16 15:44:24 +0200584 return -EINVAL;
585 }
586
587 ubi->autoresize_vol_id = i;
588 }
589
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400590 ubi_assert(!ubi->volumes[i]);
591 ubi->volumes[i] = vol;
592 ubi->vol_count += 1;
593 vol->ubi = ubi;
594 reserved_pebs += vol->reserved_pebs;
595
596 /*
597 * In case of dynamic volume UBI knows nothing about how many
598 * data is stored there. So assume the whole volume is used.
599 */
600 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
601 vol->used_ebs = vol->reserved_pebs;
602 vol->last_eb_bytes = vol->usable_leb_size;
Vinit Agnihotrid08c3b72007-07-10 13:04:59 +0300603 vol->used_bytes =
604 (long long)vol->used_ebs * vol->usable_leb_size;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400605 continue;
606 }
607
608 /* Static volumes only */
609 sv = ubi_scan_find_sv(si, i);
610 if (!sv) {
611 /*
612 * No eraseblocks belonging to this volume found. We
613 * don't actually know whether this static volume is
614 * completely corrupted or just contains no data. And
615 * we cannot know this as long as data size is not
616 * stored on flash. So we just assume the volume is
617 * empty. FIXME: this should be handled.
618 */
619 continue;
620 }
621
622 if (sv->leb_count != sv->used_ebs) {
623 /*
624 * We found a static volume which misses several
625 * eraseblocks. Treat it as corrupted.
626 */
627 ubi_warn("static volume %d misses %d LEBs - corrupted",
628 sv->vol_id, sv->used_ebs - sv->leb_count);
629 vol->corrupted = 1;
630 continue;
631 }
632
633 vol->used_ebs = sv->used_ebs;
Vinit Agnihotrid08c3b72007-07-10 13:04:59 +0300634 vol->used_bytes =
635 (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400636 vol->used_bytes += sv->last_data_size;
637 vol->last_eb_bytes = sv->last_data_size;
638 }
639
Artem Bityutskiyd05c77a2007-12-17 15:42:57 +0200640 /* And add the layout volume */
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400641 vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
642 if (!vol)
643 return -ENOMEM;
644
645 vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS;
646 vol->alignment = 1;
647 vol->vol_type = UBI_DYNAMIC_VOLUME;
648 vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1;
649 memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1);
650 vol->usable_leb_size = ubi->leb_size;
651 vol->used_ebs = vol->reserved_pebs;
652 vol->last_eb_bytes = vol->reserved_pebs;
Vinit Agnihotrid08c3b72007-07-10 13:04:59 +0300653 vol->used_bytes =
654 (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
Artem Bityutskiy91f2d532008-01-24 11:23:23 +0200655 vol->vol_id = UBI_LAYOUT_VOLUME_ID;
Artem Bityutskiyd05c77a2007-12-17 15:42:57 +0200656 vol->ref_count = 1;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400657
658 ubi_assert(!ubi->volumes[i]);
659 ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol;
660 reserved_pebs += vol->reserved_pebs;
661 ubi->vol_count += 1;
662 vol->ubi = ubi;
663
664 if (reserved_pebs > ubi->avail_pebs)
665 ubi_err("not enough PEBs, required %d, available %d",
666 reserved_pebs, ubi->avail_pebs);
667 ubi->rsvd_pebs += reserved_pebs;
668 ubi->avail_pebs -= reserved_pebs;
669
670 return 0;
671}
672
673/**
674 * check_sv - check volume scanning information.
675 * @vol: UBI volume description object
676 * @sv: volume scanning information
677 *
678 * This function returns zero if the volume scanning information is consistent
679 * to the data read from the volume tabla, and %-EINVAL if not.
680 */
681static int check_sv(const struct ubi_volume *vol,
682 const struct ubi_scan_volume *sv)
683{
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300684 int err;
685
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400686 if (sv->highest_lnum >= vol->reserved_pebs) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300687 err = 1;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400688 goto bad;
689 }
690 if (sv->leb_count > vol->reserved_pebs) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300691 err = 2;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400692 goto bad;
693 }
694 if (sv->vol_type != vol->vol_type) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300695 err = 3;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400696 goto bad;
697 }
698 if (sv->used_ebs > vol->reserved_pebs) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300699 err = 4;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400700 goto bad;
701 }
702 if (sv->data_pad != vol->data_pad) {
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300703 err = 5;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400704 goto bad;
705 }
706 return 0;
707
708bad:
Artem Bityutskiy979c9292008-05-14 16:10:33 +0300709 ubi_err("bad scanning information, error %d", err);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400710 ubi_dbg_dump_sv(sv);
711 ubi_dbg_dump_vol_info(vol);
712 return -EINVAL;
713}
714
715/**
716 * check_scanning_info - check that scanning information.
717 * @ubi: UBI device description object
718 * @si: scanning information
719 *
720 * Even though we protect on-flash data by CRC checksums, we still don't trust
721 * the media. This function ensures that scanning information is consistent to
722 * the information read from the volume table. Returns zero if the scanning
723 * information is OK and %-EINVAL if it is not.
724 */
725static int check_scanning_info(const struct ubi_device *ubi,
726 struct ubi_scan_info *si)
727{
728 int err, i;
729 struct ubi_scan_volume *sv;
730 struct ubi_volume *vol;
731
732 if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) {
733 ubi_err("scanning found %d volumes, maximum is %d + %d",
734 si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots);
735 return -EINVAL;
736 }
737
Kyungmin Parkcadb40c2008-05-22 10:32:18 +0900738 if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400739 si->highest_vol_id < UBI_INTERNAL_VOL_START) {
740 ubi_err("too large volume ID %d found by scanning",
741 si->highest_vol_id);
742 return -EINVAL;
743 }
744
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400745 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
746 cond_resched();
747
748 sv = ubi_scan_find_sv(si, i);
749 vol = ubi->volumes[i];
750 if (!vol) {
751 if (sv)
752 ubi_scan_rm_volume(si, sv);
753 continue;
754 }
755
756 if (vol->reserved_pebs == 0) {
757 ubi_assert(i < ubi->vtbl_slots);
758
759 if (!sv)
760 continue;
761
762 /*
763 * During scanning we found a volume which does not
764 * exist according to the information in the volume
765 * table. This must have happened due to an unclean
766 * reboot while the volume was being removed. Discard
767 * these eraseblocks.
768 */
769 ubi_msg("finish volume %d removal", sv->vol_id);
770 ubi_scan_rm_volume(si, sv);
771 } else if (sv) {
772 err = check_sv(vol, sv);
773 if (err)
774 return err;
775 }
776 }
777
778 return 0;
779}
780
781/**
Artem Bityutskiyebaaf1a2008-07-18 13:34:32 +0300782 * ubi_read_volume_table - read the volume table.
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400783 * @ubi: UBI device description object
784 * @si: scanning information
785 *
786 * This function reads volume table, checks it, recover from errors if needed,
787 * or creates it if needed. Returns zero in case of success and a negative
788 * error code in case of failure.
789 */
790int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
791{
792 int i, err;
793 struct ubi_scan_volume *sv;
794
Christoph Hellwig3261ebd2007-05-21 17:41:46 +0300795 empty_vtbl_record.crc = cpu_to_be32(0xf116c36b);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400796
797 /*
798 * The number of supported volumes is limited by the eraseblock size
799 * and by the UBI_MAX_VOLUMES constant.
800 */
801 ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE;
802 if (ubi->vtbl_slots > UBI_MAX_VOLUMES)
803 ubi->vtbl_slots = UBI_MAX_VOLUMES;
804
805 ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
806 ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
807
Artem Bityutskiy91f2d532008-01-24 11:23:23 +0200808 sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400809 if (!sv) {
810 /*
811 * No logical eraseblocks belonging to the layout volume were
812 * found. This could mean that the flash is just empty. In
813 * this case we create empty layout volume.
814 *
815 * But if flash is not empty this must be a corruption or the
816 * MTD device just contains garbage.
817 */
818 if (si->is_empty) {
819 ubi->vtbl = create_empty_lvol(ubi, si);
820 if (IS_ERR(ubi->vtbl))
821 return PTR_ERR(ubi->vtbl);
822 } else {
823 ubi_err("the layout volume was not found");
824 return -EINVAL;
825 }
826 } else {
827 if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) {
828 /* This must not happen with proper UBI images */
829 dbg_err("too many LEBs (%d) in layout volume",
830 sv->leb_count);
831 return -EINVAL;
832 }
833
834 ubi->vtbl = process_lvol(ubi, si, sv);
835 if (IS_ERR(ubi->vtbl))
836 return PTR_ERR(ubi->vtbl);
837 }
838
839 ubi->avail_pebs = ubi->good_peb_count;
840
841 /*
842 * The layout volume is OK, initialize the corresponding in-RAM data
843 * structures.
844 */
845 err = init_volumes(ubi, si, ubi->vtbl);
846 if (err)
847 goto out_free;
848
849 /*
850 * Get sure that the scanning information is consistent to the
851 * information stored in the volume table.
852 */
853 err = check_scanning_info(ubi, si);
854 if (err)
855 goto out_free;
856
857 return 0;
858
859out_free:
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300860 vfree(ubi->vtbl);
Artem Bityutskiy9c9ec142008-07-18 13:19:52 +0300861 for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
862 kfree(ubi->volumes[i]);
863 ubi->volumes[i] = NULL;
864 }
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400865 return err;
866}
867
868#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
869
870/**
871 * paranoid_vtbl_check - check volume table.
872 * @ubi: UBI device description object
873 */
874static void paranoid_vtbl_check(const struct ubi_device *ubi)
875{
876 if (vtbl_check(ubi, ubi->vtbl)) {
877 ubi_err("paranoid check failed");
878 BUG();
879 }
880}
881
882#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */