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c91a719d KP |
1 | /* |
2 | * Copyright (c) International Business Machines Corp., 2006 | |
3 | * Copyright (c) Nokia Corporation, 2006, 2007 | |
4 | * | |
1a459660 | 5 | * SPDX-License-Identifier: GPL-2.0+ |
c91a719d KP |
6 | * |
7 | * Author: Artem Bityutskiy (Битюцкий Артём) | |
8 | */ | |
9 | ||
10 | /* | |
11 | * This file includes volume table manipulation code. The volume table is an | |
12 | * on-flash table containing volume meta-data like name, number of reserved | |
13 | * physical eraseblocks, type, etc. The volume table is stored in the so-called | |
14 | * "layout volume". | |
15 | * | |
16 | * The layout volume is an internal volume which is organized as follows. It | |
17 | * consists of two logical eraseblocks - LEB 0 and LEB 1. Each logical | |
18 | * eraseblock stores one volume table copy, i.e. LEB 0 and LEB 1 duplicate each | |
19 | * other. This redundancy guarantees robustness to unclean reboots. The volume | |
20 | * table is basically an array of volume table records. Each record contains | |
21 | * full information about the volume and protected by a CRC checksum. | |
22 | * | |
23 | * The volume table is changed, it is first changed in RAM. Then LEB 0 is | |
24 | * erased, and the updated volume table is written back to LEB 0. Then same for | |
25 | * LEB 1. This scheme guarantees recoverability from unclean reboots. | |
26 | * | |
27 | * In this UBI implementation the on-flash volume table does not contain any | |
28 | * information about how many data static volumes contain. This information may | |
29 | * be found from the scanning data. | |
30 | * | |
31 | * But it would still be beneficial to store this information in the volume | |
32 | * table. For example, suppose we have a static volume X, and all its physical | |
33 | * eraseblocks became bad for some reasons. Suppose we are attaching the | |
34 | * corresponding MTD device, the scanning has found no logical eraseblocks | |
35 | * corresponding to the volume X. According to the volume table volume X does | |
36 | * exist. So we don't know whether it is just empty or all its physical | |
37 | * eraseblocks went bad. So we cannot alarm the user about this corruption. | |
38 | * | |
39 | * The volume table also stores so-called "update marker", which is used for | |
40 | * volume updates. Before updating the volume, the update marker is set, and | |
41 | * after the update operation is finished, the update marker is cleared. So if | |
42 | * the update operation was interrupted (e.g. by an unclean reboot) - the | |
43 | * update marker is still there and we know that the volume's contents is | |
44 | * damaged. | |
45 | */ | |
46 | ||
47 | #ifdef UBI_LINUX | |
48 | #include <linux/crc32.h> | |
49 | #include <linux/err.h> | |
50 | #include <asm/div64.h> | |
51 | #endif | |
52 | ||
53 | #include <ubi_uboot.h> | |
54 | #include "ubi.h" | |
55 | ||
56 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
57 | static void paranoid_vtbl_check(const struct ubi_device *ubi); | |
58 | #else | |
59 | #define paranoid_vtbl_check(ubi) | |
60 | #endif | |
61 | ||
62 | /* Empty volume table record */ | |
63 | static struct ubi_vtbl_record empty_vtbl_record; | |
64 | ||
65 | /** | |
66 | * ubi_change_vtbl_record - change volume table record. | |
67 | * @ubi: UBI device description object | |
68 | * @idx: table index to change | |
69 | * @vtbl_rec: new volume table record | |
70 | * | |
71 | * This function changes volume table record @idx. If @vtbl_rec is %NULL, empty | |
72 | * volume table record is written. The caller does not have to calculate CRC of | |
73 | * the record as it is done by this function. Returns zero in case of success | |
74 | * and a negative error code in case of failure. | |
75 | */ | |
76 | int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, | |
77 | struct ubi_vtbl_record *vtbl_rec) | |
78 | { | |
79 | int i, err; | |
80 | uint32_t crc; | |
81 | struct ubi_volume *layout_vol; | |
82 | ||
83 | ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); | |
84 | layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)]; | |
85 | ||
86 | if (!vtbl_rec) | |
87 | vtbl_rec = &empty_vtbl_record; | |
88 | else { | |
89 | crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); | |
90 | vtbl_rec->crc = cpu_to_be32(crc); | |
91 | } | |
92 | ||
93 | memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); | |
94 | for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { | |
95 | err = ubi_eba_unmap_leb(ubi, layout_vol, i); | |
96 | if (err) | |
97 | return err; | |
98 | ||
99 | err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0, | |
100 | ubi->vtbl_size, UBI_LONGTERM); | |
101 | if (err) | |
102 | return err; | |
103 | } | |
104 | ||
105 | paranoid_vtbl_check(ubi); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | /** | |
110 | * vtbl_check - check if volume table is not corrupted and contains sensible | |
111 | * data. | |
112 | * @ubi: UBI device description object | |
113 | * @vtbl: volume table | |
114 | * | |
115 | * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, | |
116 | * and %-EINVAL if it contains inconsistent data. | |
117 | */ | |
118 | static int vtbl_check(const struct ubi_device *ubi, | |
119 | const struct ubi_vtbl_record *vtbl) | |
120 | { | |
121 | int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; | |
122 | int upd_marker, err; | |
123 | uint32_t crc; | |
124 | const char *name; | |
125 | ||
126 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
127 | cond_resched(); | |
128 | ||
129 | reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); | |
130 | alignment = be32_to_cpu(vtbl[i].alignment); | |
131 | data_pad = be32_to_cpu(vtbl[i].data_pad); | |
132 | upd_marker = vtbl[i].upd_marker; | |
133 | vol_type = vtbl[i].vol_type; | |
134 | name_len = be16_to_cpu(vtbl[i].name_len); | |
135 | name = (const char *) &vtbl[i].name[0]; | |
136 | ||
137 | crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); | |
138 | if (be32_to_cpu(vtbl[i].crc) != crc) { | |
139 | ubi_err("bad CRC at record %u: %#08x, not %#08x", | |
140 | i, crc, be32_to_cpu(vtbl[i].crc)); | |
141 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
142 | return 1; | |
143 | } | |
144 | ||
145 | if (reserved_pebs == 0) { | |
146 | if (memcmp(&vtbl[i], &empty_vtbl_record, | |
147 | UBI_VTBL_RECORD_SIZE)) { | |
148 | err = 2; | |
149 | goto bad; | |
150 | } | |
151 | continue; | |
152 | } | |
153 | ||
154 | if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || | |
155 | name_len < 0) { | |
156 | err = 3; | |
157 | goto bad; | |
158 | } | |
159 | ||
160 | if (alignment > ubi->leb_size || alignment == 0) { | |
161 | err = 4; | |
162 | goto bad; | |
163 | } | |
164 | ||
165 | n = alignment & (ubi->min_io_size - 1); | |
166 | if (alignment != 1 && n) { | |
167 | err = 5; | |
168 | goto bad; | |
169 | } | |
170 | ||
171 | n = ubi->leb_size % alignment; | |
172 | if (data_pad != n) { | |
173 | dbg_err("bad data_pad, has to be %d", n); | |
174 | err = 6; | |
175 | goto bad; | |
176 | } | |
177 | ||
178 | if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { | |
179 | err = 7; | |
180 | goto bad; | |
181 | } | |
182 | ||
183 | if (upd_marker != 0 && upd_marker != 1) { | |
184 | err = 8; | |
185 | goto bad; | |
186 | } | |
187 | ||
188 | if (reserved_pebs > ubi->good_peb_count) { | |
189 | dbg_err("too large reserved_pebs, good PEBs %d", | |
190 | ubi->good_peb_count); | |
191 | err = 9; | |
192 | goto bad; | |
193 | } | |
194 | ||
195 | if (name_len > UBI_VOL_NAME_MAX) { | |
196 | err = 10; | |
197 | goto bad; | |
198 | } | |
199 | ||
200 | if (name[0] == '\0') { | |
201 | err = 11; | |
202 | goto bad; | |
203 | } | |
204 | ||
205 | if (name_len != strnlen(name, name_len + 1)) { | |
206 | err = 12; | |
207 | goto bad; | |
208 | } | |
209 | } | |
210 | ||
211 | /* Checks that all names are unique */ | |
212 | for (i = 0; i < ubi->vtbl_slots - 1; i++) { | |
213 | for (n = i + 1; n < ubi->vtbl_slots; n++) { | |
214 | int len1 = be16_to_cpu(vtbl[i].name_len); | |
215 | int len2 = be16_to_cpu(vtbl[n].name_len); | |
216 | ||
217 | if (len1 > 0 && len1 == len2 && | |
218 | !strncmp((char *)vtbl[i].name, (char *)vtbl[n].name, len1)) { | |
219 | ubi_err("volumes %d and %d have the same name" | |
220 | " \"%s\"", i, n, vtbl[i].name); | |
221 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
222 | ubi_dbg_dump_vtbl_record(&vtbl[n], n); | |
223 | return -EINVAL; | |
224 | } | |
225 | } | |
226 | } | |
227 | ||
228 | return 0; | |
229 | ||
230 | bad: | |
231 | ubi_err("volume table check failed: record %d, error %d", i, err); | |
232 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
233 | return -EINVAL; | |
234 | } | |
235 | ||
236 | /** | |
237 | * create_vtbl - create a copy of volume table. | |
238 | * @ubi: UBI device description object | |
239 | * @si: scanning information | |
240 | * @copy: number of the volume table copy | |
241 | * @vtbl: contents of the volume table | |
242 | * | |
243 | * This function returns zero in case of success and a negative error code in | |
244 | * case of failure. | |
245 | */ | |
246 | static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si, | |
247 | int copy, void *vtbl) | |
248 | { | |
249 | int err, tries = 0; | |
250 | static struct ubi_vid_hdr *vid_hdr; | |
251 | struct ubi_scan_volume *sv; | |
252 | struct ubi_scan_leb *new_seb, *old_seb = NULL; | |
253 | ||
254 | ubi_msg("create volume table (copy #%d)", copy + 1); | |
255 | ||
256 | vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); | |
257 | if (!vid_hdr) | |
258 | return -ENOMEM; | |
259 | ||
260 | /* | |
261 | * Check if there is a logical eraseblock which would have to contain | |
262 | * this volume table copy was found during scanning. It has to be wiped | |
263 | * out. | |
264 | */ | |
265 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID); | |
266 | if (sv) | |
267 | old_seb = ubi_scan_find_seb(sv, copy); | |
268 | ||
269 | retry: | |
270 | new_seb = ubi_scan_get_free_peb(ubi, si); | |
271 | if (IS_ERR(new_seb)) { | |
272 | err = PTR_ERR(new_seb); | |
273 | goto out_free; | |
274 | } | |
275 | ||
276 | vid_hdr->vol_type = UBI_VID_DYNAMIC; | |
277 | vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID); | |
278 | vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; | |
279 | vid_hdr->data_size = vid_hdr->used_ebs = | |
280 | vid_hdr->data_pad = cpu_to_be32(0); | |
281 | vid_hdr->lnum = cpu_to_be32(copy); | |
282 | vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum); | |
283 | vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0); | |
284 | ||
285 | /* The EC header is already there, write the VID header */ | |
286 | err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr); | |
287 | if (err) | |
288 | goto write_error; | |
289 | ||
290 | /* Write the layout volume contents */ | |
291 | err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size); | |
292 | if (err) | |
293 | goto write_error; | |
294 | ||
295 | /* | |
296 | * And add it to the scanning information. Don't delete the old | |
297 | * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'. | |
298 | */ | |
299 | err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, | |
300 | vid_hdr, 0); | |
301 | kfree(new_seb); | |
302 | ubi_free_vid_hdr(ubi, vid_hdr); | |
303 | return err; | |
304 | ||
305 | write_error: | |
306 | if (err == -EIO && ++tries <= 5) { | |
307 | /* | |
308 | * Probably this physical eraseblock went bad, try to pick | |
309 | * another one. | |
310 | */ | |
311 | list_add_tail(&new_seb->u.list, &si->corr); | |
312 | goto retry; | |
313 | } | |
314 | kfree(new_seb); | |
315 | out_free: | |
316 | ubi_free_vid_hdr(ubi, vid_hdr); | |
317 | return err; | |
318 | ||
319 | } | |
320 | ||
321 | /** | |
322 | * process_lvol - process the layout volume. | |
323 | * @ubi: UBI device description object | |
324 | * @si: scanning information | |
325 | * @sv: layout volume scanning information | |
326 | * | |
327 | * This function is responsible for reading the layout volume, ensuring it is | |
328 | * not corrupted, and recovering from corruptions if needed. Returns volume | |
329 | * table in case of success and a negative error code in case of failure. | |
330 | */ | |
331 | static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, | |
332 | struct ubi_scan_info *si, | |
333 | struct ubi_scan_volume *sv) | |
334 | { | |
335 | int err; | |
336 | struct rb_node *rb; | |
337 | struct ubi_scan_leb *seb; | |
338 | struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; | |
339 | int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; | |
340 | ||
341 | /* | |
342 | * UBI goes through the following steps when it changes the layout | |
343 | * volume: | |
344 | * a. erase LEB 0; | |
345 | * b. write new data to LEB 0; | |
346 | * c. erase LEB 1; | |
347 | * d. write new data to LEB 1. | |
348 | * | |
349 | * Before the change, both LEBs contain the same data. | |
350 | * | |
351 | * Due to unclean reboots, the contents of LEB 0 may be lost, but there | |
352 | * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. | |
353 | * Similarly, LEB 1 may be lost, but there should be LEB 0. And | |
354 | * finally, unclean reboots may result in a situation when neither LEB | |
355 | * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB | |
356 | * 0 contains more recent information. | |
357 | * | |
358 | * So the plan is to first check LEB 0. Then | |
359 | * a. if LEB 0 is OK, it must be containing the most resent data; then | |
360 | * we compare it with LEB 1, and if they are different, we copy LEB | |
361 | * 0 to LEB 1; | |
362 | * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 | |
363 | * to LEB 0. | |
364 | */ | |
365 | ||
366 | dbg_msg("check layout volume"); | |
367 | ||
368 | /* Read both LEB 0 and LEB 1 into memory */ | |
369 | ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { | |
370 | leb[seb->lnum] = vmalloc(ubi->vtbl_size); | |
371 | if (!leb[seb->lnum]) { | |
372 | err = -ENOMEM; | |
373 | goto out_free; | |
374 | } | |
375 | memset(leb[seb->lnum], 0, ubi->vtbl_size); | |
376 | ||
377 | err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0, | |
378 | ubi->vtbl_size); | |
dfe64e2c | 379 | if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) |
c91a719d KP |
380 | /* |
381 | * Scrub the PEB later. Note, -EBADMSG indicates an | |
382 | * uncorrectable ECC error, but we have our own CRC and | |
383 | * the data will be checked later. If the data is OK, | |
384 | * the PEB will be scrubbed (because we set | |
385 | * seb->scrub). If the data is not OK, the contents of | |
386 | * the PEB will be recovered from the second copy, and | |
387 | * seb->scrub will be cleared in | |
388 | * 'ubi_scan_add_used()'. | |
389 | */ | |
390 | seb->scrub = 1; | |
391 | else if (err) | |
392 | goto out_free; | |
393 | } | |
394 | ||
395 | err = -EINVAL; | |
396 | if (leb[0]) { | |
397 | leb_corrupted[0] = vtbl_check(ubi, leb[0]); | |
398 | if (leb_corrupted[0] < 0) | |
399 | goto out_free; | |
400 | } | |
401 | ||
402 | if (!leb_corrupted[0]) { | |
403 | /* LEB 0 is OK */ | |
404 | if (leb[1]) | |
405 | leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size); | |
406 | if (leb_corrupted[1]) { | |
407 | ubi_warn("volume table copy #2 is corrupted"); | |
408 | err = create_vtbl(ubi, si, 1, leb[0]); | |
409 | if (err) | |
410 | goto out_free; | |
411 | ubi_msg("volume table was restored"); | |
412 | } | |
413 | ||
414 | /* Both LEB 1 and LEB 2 are OK and consistent */ | |
415 | vfree(leb[1]); | |
416 | return leb[0]; | |
417 | } else { | |
418 | /* LEB 0 is corrupted or does not exist */ | |
419 | if (leb[1]) { | |
420 | leb_corrupted[1] = vtbl_check(ubi, leb[1]); | |
421 | if (leb_corrupted[1] < 0) | |
422 | goto out_free; | |
423 | } | |
424 | if (leb_corrupted[1]) { | |
425 | /* Both LEB 0 and LEB 1 are corrupted */ | |
426 | ubi_err("both volume tables are corrupted"); | |
427 | goto out_free; | |
428 | } | |
429 | ||
430 | ubi_warn("volume table copy #1 is corrupted"); | |
431 | err = create_vtbl(ubi, si, 0, leb[1]); | |
432 | if (err) | |
433 | goto out_free; | |
434 | ubi_msg("volume table was restored"); | |
435 | ||
436 | vfree(leb[0]); | |
437 | return leb[1]; | |
438 | } | |
439 | ||
440 | out_free: | |
441 | vfree(leb[0]); | |
442 | vfree(leb[1]); | |
443 | return ERR_PTR(err); | |
444 | } | |
445 | ||
446 | /** | |
447 | * create_empty_lvol - create empty layout volume. | |
448 | * @ubi: UBI device description object | |
449 | * @si: scanning information | |
450 | * | |
451 | * This function returns volume table contents in case of success and a | |
452 | * negative error code in case of failure. | |
453 | */ | |
454 | static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, | |
455 | struct ubi_scan_info *si) | |
456 | { | |
457 | int i; | |
458 | struct ubi_vtbl_record *vtbl; | |
459 | ||
460 | vtbl = vmalloc(ubi->vtbl_size); | |
461 | if (!vtbl) | |
462 | return ERR_PTR(-ENOMEM); | |
463 | memset(vtbl, 0, ubi->vtbl_size); | |
464 | ||
465 | for (i = 0; i < ubi->vtbl_slots; i++) | |
466 | memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); | |
467 | ||
468 | for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { | |
469 | int err; | |
470 | ||
471 | err = create_vtbl(ubi, si, i, vtbl); | |
472 | if (err) { | |
473 | vfree(vtbl); | |
474 | return ERR_PTR(err); | |
475 | } | |
476 | } | |
477 | ||
478 | return vtbl; | |
479 | } | |
480 | ||
481 | /** | |
482 | * init_volumes - initialize volume information for existing volumes. | |
483 | * @ubi: UBI device description object | |
484 | * @si: scanning information | |
485 | * @vtbl: volume table | |
486 | * | |
487 | * This function allocates volume description objects for existing volumes. | |
488 | * Returns zero in case of success and a negative error code in case of | |
489 | * failure. | |
490 | */ | |
491 | static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, | |
492 | const struct ubi_vtbl_record *vtbl) | |
493 | { | |
494 | int i, reserved_pebs = 0; | |
495 | struct ubi_scan_volume *sv; | |
496 | struct ubi_volume *vol; | |
497 | ||
498 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
499 | cond_resched(); | |
500 | ||
501 | if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) | |
502 | continue; /* Empty record */ | |
503 | ||
504 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
505 | if (!vol) | |
506 | return -ENOMEM; | |
507 | ||
508 | vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); | |
509 | vol->alignment = be32_to_cpu(vtbl[i].alignment); | |
510 | vol->data_pad = be32_to_cpu(vtbl[i].data_pad); | |
ceeba003 | 511 | vol->upd_marker = vtbl[i].upd_marker; |
c91a719d KP |
512 | vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? |
513 | UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; | |
514 | vol->name_len = be16_to_cpu(vtbl[i].name_len); | |
515 | vol->usable_leb_size = ubi->leb_size - vol->data_pad; | |
516 | memcpy(vol->name, vtbl[i].name, vol->name_len); | |
517 | vol->name[vol->name_len] = '\0'; | |
518 | vol->vol_id = i; | |
519 | ||
520 | if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) { | |
521 | /* Auto re-size flag may be set only for one volume */ | |
522 | if (ubi->autoresize_vol_id != -1) { | |
523 | ubi_err("more then one auto-resize volume (%d " | |
524 | "and %d)", ubi->autoresize_vol_id, i); | |
525 | kfree(vol); | |
526 | return -EINVAL; | |
527 | } | |
528 | ||
529 | ubi->autoresize_vol_id = i; | |
530 | } | |
531 | ||
532 | ubi_assert(!ubi->volumes[i]); | |
533 | ubi->volumes[i] = vol; | |
534 | ubi->vol_count += 1; | |
535 | vol->ubi = ubi; | |
536 | reserved_pebs += vol->reserved_pebs; | |
537 | ||
538 | /* | |
539 | * In case of dynamic volume UBI knows nothing about how many | |
540 | * data is stored there. So assume the whole volume is used. | |
541 | */ | |
542 | if (vol->vol_type == UBI_DYNAMIC_VOLUME) { | |
543 | vol->used_ebs = vol->reserved_pebs; | |
544 | vol->last_eb_bytes = vol->usable_leb_size; | |
545 | vol->used_bytes = | |
546 | (long long)vol->used_ebs * vol->usable_leb_size; | |
547 | continue; | |
548 | } | |
549 | ||
550 | /* Static volumes only */ | |
551 | sv = ubi_scan_find_sv(si, i); | |
552 | if (!sv) { | |
553 | /* | |
554 | * No eraseblocks belonging to this volume found. We | |
555 | * don't actually know whether this static volume is | |
556 | * completely corrupted or just contains no data. And | |
557 | * we cannot know this as long as data size is not | |
558 | * stored on flash. So we just assume the volume is | |
559 | * empty. FIXME: this should be handled. | |
560 | */ | |
561 | continue; | |
562 | } | |
563 | ||
564 | if (sv->leb_count != sv->used_ebs) { | |
565 | /* | |
566 | * We found a static volume which misses several | |
567 | * eraseblocks. Treat it as corrupted. | |
568 | */ | |
569 | ubi_warn("static volume %d misses %d LEBs - corrupted", | |
570 | sv->vol_id, sv->used_ebs - sv->leb_count); | |
571 | vol->corrupted = 1; | |
572 | continue; | |
573 | } | |
574 | ||
575 | vol->used_ebs = sv->used_ebs; | |
576 | vol->used_bytes = | |
577 | (long long)(vol->used_ebs - 1) * vol->usable_leb_size; | |
578 | vol->used_bytes += sv->last_data_size; | |
579 | vol->last_eb_bytes = sv->last_data_size; | |
580 | } | |
581 | ||
582 | /* And add the layout volume */ | |
583 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
584 | if (!vol) | |
585 | return -ENOMEM; | |
586 | ||
587 | vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; | |
588 | vol->alignment = 1; | |
589 | vol->vol_type = UBI_DYNAMIC_VOLUME; | |
590 | vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; | |
591 | memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); | |
592 | vol->usable_leb_size = ubi->leb_size; | |
593 | vol->used_ebs = vol->reserved_pebs; | |
594 | vol->last_eb_bytes = vol->reserved_pebs; | |
595 | vol->used_bytes = | |
596 | (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); | |
597 | vol->vol_id = UBI_LAYOUT_VOLUME_ID; | |
598 | vol->ref_count = 1; | |
599 | ||
600 | ubi_assert(!ubi->volumes[i]); | |
601 | ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; | |
602 | reserved_pebs += vol->reserved_pebs; | |
603 | ubi->vol_count += 1; | |
604 | vol->ubi = ubi; | |
605 | ||
606 | if (reserved_pebs > ubi->avail_pebs) | |
607 | ubi_err("not enough PEBs, required %d, available %d", | |
608 | reserved_pebs, ubi->avail_pebs); | |
609 | ubi->rsvd_pebs += reserved_pebs; | |
610 | ubi->avail_pebs -= reserved_pebs; | |
611 | ||
612 | return 0; | |
613 | } | |
614 | ||
615 | /** | |
616 | * check_sv - check volume scanning information. | |
617 | * @vol: UBI volume description object | |
618 | * @sv: volume scanning information | |
619 | * | |
620 | * This function returns zero if the volume scanning information is consistent | |
621 | * to the data read from the volume tabla, and %-EINVAL if not. | |
622 | */ | |
623 | static int check_sv(const struct ubi_volume *vol, | |
624 | const struct ubi_scan_volume *sv) | |
625 | { | |
626 | int err; | |
627 | ||
628 | if (sv->highest_lnum >= vol->reserved_pebs) { | |
629 | err = 1; | |
630 | goto bad; | |
631 | } | |
632 | if (sv->leb_count > vol->reserved_pebs) { | |
633 | err = 2; | |
634 | goto bad; | |
635 | } | |
636 | if (sv->vol_type != vol->vol_type) { | |
637 | err = 3; | |
638 | goto bad; | |
639 | } | |
640 | if (sv->used_ebs > vol->reserved_pebs) { | |
641 | err = 4; | |
642 | goto bad; | |
643 | } | |
644 | if (sv->data_pad != vol->data_pad) { | |
645 | err = 5; | |
646 | goto bad; | |
647 | } | |
648 | return 0; | |
649 | ||
650 | bad: | |
651 | ubi_err("bad scanning information, error %d", err); | |
652 | ubi_dbg_dump_sv(sv); | |
653 | ubi_dbg_dump_vol_info(vol); | |
654 | return -EINVAL; | |
655 | } | |
656 | ||
657 | /** | |
658 | * check_scanning_info - check that scanning information. | |
659 | * @ubi: UBI device description object | |
660 | * @si: scanning information | |
661 | * | |
662 | * Even though we protect on-flash data by CRC checksums, we still don't trust | |
663 | * the media. This function ensures that scanning information is consistent to | |
664 | * the information read from the volume table. Returns zero if the scanning | |
665 | * information is OK and %-EINVAL if it is not. | |
666 | */ | |
667 | static int check_scanning_info(const struct ubi_device *ubi, | |
668 | struct ubi_scan_info *si) | |
669 | { | |
670 | int err, i; | |
671 | struct ubi_scan_volume *sv; | |
672 | struct ubi_volume *vol; | |
673 | ||
674 | if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { | |
675 | ubi_err("scanning found %d volumes, maximum is %d + %d", | |
676 | si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); | |
677 | return -EINVAL; | |
678 | } | |
679 | ||
680 | if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && | |
681 | si->highest_vol_id < UBI_INTERNAL_VOL_START) { | |
682 | ubi_err("too large volume ID %d found by scanning", | |
683 | si->highest_vol_id); | |
684 | return -EINVAL; | |
685 | } | |
686 | ||
687 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { | |
688 | cond_resched(); | |
689 | ||
690 | sv = ubi_scan_find_sv(si, i); | |
691 | vol = ubi->volumes[i]; | |
692 | if (!vol) { | |
693 | if (sv) | |
694 | ubi_scan_rm_volume(si, sv); | |
695 | continue; | |
696 | } | |
697 | ||
698 | if (vol->reserved_pebs == 0) { | |
699 | ubi_assert(i < ubi->vtbl_slots); | |
700 | ||
701 | if (!sv) | |
702 | continue; | |
703 | ||
704 | /* | |
705 | * During scanning we found a volume which does not | |
706 | * exist according to the information in the volume | |
707 | * table. This must have happened due to an unclean | |
708 | * reboot while the volume was being removed. Discard | |
709 | * these eraseblocks. | |
710 | */ | |
711 | ubi_msg("finish volume %d removal", sv->vol_id); | |
712 | ubi_scan_rm_volume(si, sv); | |
713 | } else if (sv) { | |
714 | err = check_sv(vol, sv); | |
715 | if (err) | |
716 | return err; | |
717 | } | |
718 | } | |
719 | ||
720 | return 0; | |
721 | } | |
722 | ||
723 | /** | |
724 | * ubi_read_volume_table - read volume table. | |
725 | * information. | |
726 | * @ubi: UBI device description object | |
727 | * @si: scanning information | |
728 | * | |
729 | * This function reads volume table, checks it, recover from errors if needed, | |
730 | * or creates it if needed. Returns zero in case of success and a negative | |
731 | * error code in case of failure. | |
732 | */ | |
733 | int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si) | |
734 | { | |
735 | int i, err; | |
736 | struct ubi_scan_volume *sv; | |
737 | ||
738 | empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); | |
739 | ||
740 | /* | |
741 | * The number of supported volumes is limited by the eraseblock size | |
742 | * and by the UBI_MAX_VOLUMES constant. | |
743 | */ | |
744 | ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; | |
745 | if (ubi->vtbl_slots > UBI_MAX_VOLUMES) | |
746 | ubi->vtbl_slots = UBI_MAX_VOLUMES; | |
747 | ||
748 | ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; | |
749 | ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); | |
750 | ||
751 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID); | |
752 | if (!sv) { | |
753 | /* | |
754 | * No logical eraseblocks belonging to the layout volume were | |
755 | * found. This could mean that the flash is just empty. In | |
756 | * this case we create empty layout volume. | |
757 | * | |
758 | * But if flash is not empty this must be a corruption or the | |
759 | * MTD device just contains garbage. | |
760 | */ | |
761 | if (si->is_empty) { | |
762 | ubi->vtbl = create_empty_lvol(ubi, si); | |
763 | if (IS_ERR(ubi->vtbl)) | |
764 | return PTR_ERR(ubi->vtbl); | |
765 | } else { | |
766 | ubi_err("the layout volume was not found"); | |
767 | return -EINVAL; | |
768 | } | |
769 | } else { | |
770 | if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) { | |
771 | /* This must not happen with proper UBI images */ | |
772 | dbg_err("too many LEBs (%d) in layout volume", | |
773 | sv->leb_count); | |
774 | return -EINVAL; | |
775 | } | |
776 | ||
777 | ubi->vtbl = process_lvol(ubi, si, sv); | |
778 | if (IS_ERR(ubi->vtbl)) | |
779 | return PTR_ERR(ubi->vtbl); | |
780 | } | |
781 | ||
782 | ubi->avail_pebs = ubi->good_peb_count; | |
783 | ||
784 | /* | |
785 | * The layout volume is OK, initialize the corresponding in-RAM data | |
786 | * structures. | |
787 | */ | |
788 | err = init_volumes(ubi, si, ubi->vtbl); | |
789 | if (err) | |
790 | goto out_free; | |
791 | ||
792 | /* | |
793 | * Get sure that the scanning information is consistent to the | |
794 | * information stored in the volume table. | |
795 | */ | |
796 | err = check_scanning_info(ubi, si); | |
797 | if (err) | |
798 | goto out_free; | |
799 | ||
800 | return 0; | |
801 | ||
802 | out_free: | |
803 | vfree(ubi->vtbl); | |
804 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) | |
805 | if (ubi->volumes[i]) { | |
806 | kfree(ubi->volumes[i]); | |
807 | ubi->volumes[i] = NULL; | |
808 | } | |
809 | return err; | |
810 | } | |
811 | ||
812 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
813 | ||
814 | /** | |
815 | * paranoid_vtbl_check - check volume table. | |
816 | * @ubi: UBI device description object | |
817 | */ | |
818 | static void paranoid_vtbl_check(const struct ubi_device *ubi) | |
819 | { | |
820 | if (vtbl_check(ubi, ubi->vtbl)) { | |
821 | ubi_err("paranoid check failed"); | |
822 | BUG(); | |
823 | } | |
824 | } | |
825 | ||
826 | #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ |