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801c135c AB |
1 | /* |
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 | |
65 | static 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 */ | |
71 | static 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 | */ | |
84 | int 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; | |
89 | ||
90 | ubi_assert(idx >= 0 && idx < ubi->vtbl_slots); | |
91 | ||
92 | if (!vtbl_rec) | |
93 | vtbl_rec = &empty_vtbl_record; | |
94 | else { | |
95 | crc = crc32(UBI_CRC32_INIT, vtbl_rec, UBI_VTBL_RECORD_SIZE_CRC); | |
96 | vtbl_rec->crc = cpu_to_ubi32(crc); | |
97 | } | |
98 | ||
99 | dbg_msg("change record %d", idx); | |
100 | ubi_dbg_dump_vtbl_record(vtbl_rec, idx); | |
101 | ||
102 | mutex_lock(&ubi->vtbl_mutex); | |
103 | memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); | |
104 | for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { | |
105 | err = ubi_eba_unmap_leb(ubi, UBI_LAYOUT_VOL_ID, i); | |
106 | if (err) { | |
107 | mutex_unlock(&ubi->vtbl_mutex); | |
108 | return err; | |
109 | } | |
110 | err = ubi_eba_write_leb(ubi, UBI_LAYOUT_VOL_ID, i, ubi->vtbl, 0, | |
111 | ubi->vtbl_size, UBI_LONGTERM); | |
112 | if (err) { | |
113 | mutex_unlock(&ubi->vtbl_mutex); | |
114 | return err; | |
115 | } | |
116 | } | |
117 | ||
118 | paranoid_vtbl_check(ubi); | |
119 | mutex_unlock(&ubi->vtbl_mutex); | |
120 | return ubi_wl_flush(ubi); | |
121 | } | |
122 | ||
123 | /** | |
124 | * vol_til_check - check if volume table is not corrupted and contains sensible | |
125 | * data. | |
126 | * | |
127 | * @ubi: UBI device description object | |
128 | * @vtbl: volume table | |
129 | * | |
130 | * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, | |
131 | * and %-EINVAL if it contains inconsistent data. | |
132 | */ | |
133 | static int vtbl_check(const struct ubi_device *ubi, | |
134 | const struct ubi_vtbl_record *vtbl) | |
135 | { | |
136 | int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; | |
137 | int upd_marker; | |
138 | uint32_t crc; | |
139 | const char *name; | |
140 | ||
141 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
142 | cond_resched(); | |
143 | ||
144 | reserved_pebs = ubi32_to_cpu(vtbl[i].reserved_pebs); | |
145 | alignment = ubi32_to_cpu(vtbl[i].alignment); | |
146 | data_pad = ubi32_to_cpu(vtbl[i].data_pad); | |
147 | upd_marker = vtbl[i].upd_marker; | |
148 | vol_type = vtbl[i].vol_type; | |
149 | name_len = ubi16_to_cpu(vtbl[i].name_len); | |
150 | name = &vtbl[i].name[0]; | |
151 | ||
152 | crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); | |
153 | if (ubi32_to_cpu(vtbl[i].crc) != crc) { | |
154 | ubi_err("bad CRC at record %u: %#08x, not %#08x", | |
155 | i, crc, ubi32_to_cpu(vtbl[i].crc)); | |
156 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
157 | return 1; | |
158 | } | |
159 | ||
160 | if (reserved_pebs == 0) { | |
161 | if (memcmp(&vtbl[i], &empty_vtbl_record, | |
162 | UBI_VTBL_RECORD_SIZE)) { | |
163 | dbg_err("bad empty record"); | |
164 | goto bad; | |
165 | } | |
166 | continue; | |
167 | } | |
168 | ||
169 | if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || | |
170 | name_len < 0) { | |
171 | dbg_err("negative values"); | |
172 | goto bad; | |
173 | } | |
174 | ||
175 | if (alignment > ubi->leb_size || alignment == 0) { | |
176 | dbg_err("bad alignment"); | |
177 | goto bad; | |
178 | } | |
179 | ||
180 | n = alignment % ubi->min_io_size; | |
181 | if (alignment != 1 && n) { | |
182 | dbg_err("alignment is not multiple of min I/O unit"); | |
183 | goto bad; | |
184 | } | |
185 | ||
186 | n = ubi->leb_size % alignment; | |
187 | if (data_pad != n) { | |
188 | dbg_err("bad data_pad, has to be %d", n); | |
189 | goto bad; | |
190 | } | |
191 | ||
192 | if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { | |
193 | dbg_err("bad vol_type"); | |
194 | goto bad; | |
195 | } | |
196 | ||
197 | if (upd_marker != 0 && upd_marker != 1) { | |
198 | dbg_err("bad upd_marker"); | |
199 | goto bad; | |
200 | } | |
201 | ||
202 | if (reserved_pebs > ubi->good_peb_count) { | |
203 | dbg_err("too large reserved_pebs, good PEBs %d", | |
204 | ubi->good_peb_count); | |
205 | goto bad; | |
206 | } | |
207 | ||
208 | if (name_len > UBI_VOL_NAME_MAX) { | |
209 | dbg_err("too long volume name, max %d", | |
210 | UBI_VOL_NAME_MAX); | |
211 | goto bad; | |
212 | } | |
213 | ||
214 | if (name[0] == '\0') { | |
215 | dbg_err("NULL volume name"); | |
216 | goto bad; | |
217 | } | |
218 | ||
219 | if (name_len != strnlen(name, name_len + 1)) { | |
220 | dbg_err("bad name_len"); | |
221 | goto bad; | |
222 | } | |
223 | } | |
224 | ||
225 | /* Checks that all names are unique */ | |
226 | for (i = 0; i < ubi->vtbl_slots - 1; i++) { | |
227 | for (n = i + 1; n < ubi->vtbl_slots; n++) { | |
228 | int len1 = ubi16_to_cpu(vtbl[i].name_len); | |
229 | int len2 = ubi16_to_cpu(vtbl[n].name_len); | |
230 | ||
231 | if (len1 > 0 && len1 == len2 && | |
232 | !strncmp(vtbl[i].name, vtbl[n].name, len1)) { | |
233 | ubi_err("volumes %d and %d have the same name" | |
234 | " \"%s\"", i, n, vtbl[i].name); | |
235 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
236 | ubi_dbg_dump_vtbl_record(&vtbl[n], n); | |
237 | return -EINVAL; | |
238 | } | |
239 | } | |
240 | } | |
241 | ||
242 | return 0; | |
243 | ||
244 | bad: | |
245 | ubi_err("volume table check failed, record %d", i); | |
246 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
247 | return -EINVAL; | |
248 | } | |
249 | ||
250 | /** | |
251 | * create_vtbl - create a copy of volume table. | |
252 | * @ubi: UBI device description object | |
253 | * @si: scanning information | |
254 | * @copy: number of the volume table copy | |
255 | * @vtbl: contents of the volume table | |
256 | * | |
257 | * This function returns zero in case of success and a negative error code in | |
258 | * case of failure. | |
259 | */ | |
260 | static int create_vtbl(const struct ubi_device *ubi, struct ubi_scan_info *si, | |
261 | int copy, void *vtbl) | |
262 | { | |
263 | int err, tries = 0; | |
264 | static struct ubi_vid_hdr *vid_hdr; | |
265 | struct ubi_scan_volume *sv; | |
266 | struct ubi_scan_leb *new_seb, *old_seb = NULL; | |
267 | ||
268 | ubi_msg("create volume table (copy #%d)", copy + 1); | |
269 | ||
270 | vid_hdr = ubi_zalloc_vid_hdr(ubi); | |
271 | if (!vid_hdr) | |
272 | return -ENOMEM; | |
273 | ||
274 | /* | |
275 | * Check if there is a logical eraseblock which would have to contain | |
276 | * this volume table copy was found during scanning. It has to be wiped | |
277 | * out. | |
278 | */ | |
279 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); | |
280 | if (sv) | |
281 | old_seb = ubi_scan_find_seb(sv, copy); | |
282 | ||
283 | retry: | |
284 | new_seb = ubi_scan_get_free_peb(ubi, si); | |
285 | if (IS_ERR(new_seb)) { | |
286 | err = PTR_ERR(new_seb); | |
287 | goto out_free; | |
288 | } | |
289 | ||
290 | vid_hdr->vol_type = UBI_VID_DYNAMIC; | |
291 | vid_hdr->vol_id = cpu_to_ubi32(UBI_LAYOUT_VOL_ID); | |
292 | vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; | |
293 | vid_hdr->data_size = vid_hdr->used_ebs = | |
294 | vid_hdr->data_pad = cpu_to_ubi32(0); | |
295 | vid_hdr->lnum = cpu_to_ubi32(copy); | |
296 | vid_hdr->sqnum = cpu_to_ubi64(++si->max_sqnum); | |
297 | vid_hdr->leb_ver = cpu_to_ubi32(old_seb ? old_seb->leb_ver + 1: 0); | |
298 | ||
299 | /* The EC header is already there, write the VID header */ | |
300 | err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr); | |
301 | if (err) | |
302 | goto write_error; | |
303 | ||
304 | /* Write the layout volume contents */ | |
305 | err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size); | |
306 | if (err) | |
307 | goto write_error; | |
308 | ||
309 | /* | |
310 | * And add it to the scanning information. Don't delete the old | |
311 | * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'. | |
312 | */ | |
313 | err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, | |
314 | vid_hdr, 0); | |
315 | kfree(new_seb); | |
316 | ubi_free_vid_hdr(ubi, vid_hdr); | |
317 | return err; | |
318 | ||
319 | write_error: | |
320 | kfree(new_seb); | |
321 | /* May be this physical eraseblock went bad, try to pick another one */ | |
322 | if (++tries <= 5) { | |
323 | err = ubi_scan_add_to_list(si, new_seb->pnum, new_seb->ec, | |
324 | &si->corr); | |
325 | if (!err) | |
326 | goto retry; | |
327 | } | |
328 | out_free: | |
329 | ubi_free_vid_hdr(ubi, vid_hdr); | |
330 | return err; | |
331 | ||
332 | } | |
333 | ||
334 | /** | |
335 | * process_lvol - process the layout volume. | |
336 | * @ubi: UBI device description object | |
337 | * @si: scanning information | |
338 | * @sv: layout volume scanning information | |
339 | * | |
340 | * This function is responsible for reading the layout volume, ensuring it is | |
341 | * not corrupted, and recovering from corruptions if needed. Returns volume | |
342 | * table in case of success and a negative error code in case of failure. | |
343 | */ | |
344 | static struct ubi_vtbl_record *process_lvol(const struct ubi_device *ubi, | |
345 | struct ubi_scan_info *si, | |
346 | struct ubi_scan_volume *sv) | |
347 | { | |
348 | int err; | |
349 | struct rb_node *rb; | |
350 | struct ubi_scan_leb *seb; | |
351 | struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; | |
352 | int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; | |
353 | ||
354 | /* | |
355 | * UBI goes through the following steps when it changes the layout | |
356 | * volume: | |
357 | * a. erase LEB 0; | |
358 | * b. write new data to LEB 0; | |
359 | * c. erase LEB 1; | |
360 | * d. write new data to LEB 1. | |
361 | * | |
362 | * Before the change, both LEBs contain the same data. | |
363 | * | |
364 | * Due to unclean reboots, the contents of LEB 0 may be lost, but there | |
365 | * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. | |
366 | * Similarly, LEB 1 may be lost, but there should be LEB 0. And | |
367 | * finally, unclean reboots may result in a situation when neither LEB | |
368 | * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB | |
369 | * 0 contains more recent information. | |
370 | * | |
371 | * So the plan is to first check LEB 0. Then | |
372 | * a. if LEB 0 is OK, it must be containing the most resent data; then | |
373 | * we compare it with LEB 1, and if they are different, we copy LEB | |
374 | * 0 to LEB 1; | |
375 | * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 | |
376 | * to LEB 0. | |
377 | */ | |
378 | ||
379 | dbg_msg("check layout volume"); | |
380 | ||
381 | /* Read both LEB 0 and LEB 1 into memory */ | |
382 | ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { | |
383 | leb[seb->lnum] = kzalloc(ubi->vtbl_size, GFP_KERNEL); | |
384 | if (!leb[seb->lnum]) { | |
385 | err = -ENOMEM; | |
386 | goto out_free; | |
387 | } | |
388 | ||
389 | err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0, | |
390 | ubi->vtbl_size); | |
391 | if (err == UBI_IO_BITFLIPS || err == -EBADMSG) | |
392 | /* Scrub the PEB later */ | |
393 | seb->scrub = 1; | |
394 | else if (err) | |
395 | goto out_free; | |
396 | } | |
397 | ||
398 | err = -EINVAL; | |
399 | if (leb[0]) { | |
400 | leb_corrupted[0] = vtbl_check(ubi, leb[0]); | |
401 | if (leb_corrupted[0] < 0) | |
402 | goto out_free; | |
403 | } | |
404 | ||
405 | if (!leb_corrupted[0]) { | |
406 | /* LEB 0 is OK */ | |
407 | if (leb[1]) | |
408 | leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size); | |
409 | if (leb_corrupted[1]) { | |
410 | ubi_warn("volume table copy #2 is corrupted"); | |
411 | err = create_vtbl(ubi, si, 1, leb[0]); | |
412 | if (err) | |
413 | goto out_free; | |
414 | ubi_msg("volume table was restored"); | |
415 | } | |
416 | ||
417 | /* Both LEB 1 and LEB 2 are OK and consistent */ | |
418 | kfree(leb[1]); | |
419 | return leb[0]; | |
420 | } else { | |
421 | /* LEB 0 is corrupted or does not exist */ | |
422 | if (leb[1]) { | |
423 | leb_corrupted[1] = vtbl_check(ubi, leb[1]); | |
424 | if (leb_corrupted[1] < 0) | |
425 | goto out_free; | |
426 | } | |
427 | if (leb_corrupted[1]) { | |
428 | /* Both LEB 0 and LEB 1 are corrupted */ | |
429 | ubi_err("both volume tables are corrupted"); | |
430 | goto out_free; | |
431 | } | |
432 | ||
433 | ubi_warn("volume table copy #1 is corrupted"); | |
434 | err = create_vtbl(ubi, si, 0, leb[1]); | |
435 | if (err) | |
436 | goto out_free; | |
437 | ubi_msg("volume table was restored"); | |
438 | ||
439 | kfree(leb[0]); | |
440 | return leb[1]; | |
441 | } | |
442 | ||
443 | out_free: | |
444 | kfree(leb[0]); | |
445 | kfree(leb[1]); | |
446 | return ERR_PTR(err); | |
447 | } | |
448 | ||
449 | /** | |
450 | * create_empty_lvol - create empty layout volume. | |
451 | * @ubi: UBI device description object | |
452 | * @si: scanning information | |
453 | * | |
454 | * This function returns volume table contents in case of success and a | |
455 | * negative error code in case of failure. | |
456 | */ | |
457 | static struct ubi_vtbl_record *create_empty_lvol(const struct ubi_device *ubi, | |
458 | struct ubi_scan_info *si) | |
459 | { | |
460 | int i; | |
461 | struct ubi_vtbl_record *vtbl; | |
462 | ||
463 | vtbl = kzalloc(ubi->vtbl_size, GFP_KERNEL); | |
464 | if (!vtbl) | |
465 | return ERR_PTR(-ENOMEM); | |
466 | ||
467 | for (i = 0; i < ubi->vtbl_slots; i++) | |
468 | memcpy(&vtbl[i], &empty_vtbl_record, UBI_VTBL_RECORD_SIZE); | |
469 | ||
470 | for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { | |
471 | int err; | |
472 | ||
473 | err = create_vtbl(ubi, si, i, vtbl); | |
474 | if (err) { | |
475 | kfree(vtbl); | |
476 | return ERR_PTR(err); | |
477 | } | |
478 | } | |
479 | ||
480 | return vtbl; | |
481 | } | |
482 | ||
483 | /** | |
484 | * init_volumes - initialize volume information for existing volumes. | |
485 | * @ubi: UBI device description object | |
486 | * @si: scanning information | |
487 | * @vtbl: volume table | |
488 | * | |
489 | * This function allocates volume description objects for existing volumes. | |
490 | * Returns zero in case of success and a negative error code in case of | |
491 | * failure. | |
492 | */ | |
493 | static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si, | |
494 | const struct ubi_vtbl_record *vtbl) | |
495 | { | |
496 | int i, reserved_pebs = 0; | |
497 | struct ubi_scan_volume *sv; | |
498 | struct ubi_volume *vol; | |
499 | ||
500 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
501 | cond_resched(); | |
502 | ||
503 | if (ubi32_to_cpu(vtbl[i].reserved_pebs) == 0) | |
504 | continue; /* Empty record */ | |
505 | ||
506 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
507 | if (!vol) | |
508 | return -ENOMEM; | |
509 | ||
510 | vol->reserved_pebs = ubi32_to_cpu(vtbl[i].reserved_pebs); | |
511 | vol->alignment = ubi32_to_cpu(vtbl[i].alignment); | |
512 | vol->data_pad = ubi32_to_cpu(vtbl[i].data_pad); | |
513 | vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? | |
514 | UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; | |
515 | vol->name_len = ubi16_to_cpu(vtbl[i].name_len); | |
516 | vol->usable_leb_size = ubi->leb_size - vol->data_pad; | |
517 | memcpy(vol->name, vtbl[i].name, vol->name_len); | |
518 | vol->name[vol->name_len] = '\0'; | |
519 | vol->vol_id = i; | |
520 | ||
521 | ubi_assert(!ubi->volumes[i]); | |
522 | ubi->volumes[i] = vol; | |
523 | ubi->vol_count += 1; | |
524 | vol->ubi = ubi; | |
525 | reserved_pebs += vol->reserved_pebs; | |
526 | ||
527 | /* | |
528 | * In case of dynamic volume UBI knows nothing about how many | |
529 | * data is stored there. So assume the whole volume is used. | |
530 | */ | |
531 | if (vol->vol_type == UBI_DYNAMIC_VOLUME) { | |
532 | vol->used_ebs = vol->reserved_pebs; | |
533 | vol->last_eb_bytes = vol->usable_leb_size; | |
534 | vol->used_bytes = vol->used_ebs * vol->usable_leb_size; | |
535 | continue; | |
536 | } | |
537 | ||
538 | /* Static volumes only */ | |
539 | sv = ubi_scan_find_sv(si, i); | |
540 | if (!sv) { | |
541 | /* | |
542 | * No eraseblocks belonging to this volume found. We | |
543 | * don't actually know whether this static volume is | |
544 | * completely corrupted or just contains no data. And | |
545 | * we cannot know this as long as data size is not | |
546 | * stored on flash. So we just assume the volume is | |
547 | * empty. FIXME: this should be handled. | |
548 | */ | |
549 | continue; | |
550 | } | |
551 | ||
552 | if (sv->leb_count != sv->used_ebs) { | |
553 | /* | |
554 | * We found a static volume which misses several | |
555 | * eraseblocks. Treat it as corrupted. | |
556 | */ | |
557 | ubi_warn("static volume %d misses %d LEBs - corrupted", | |
558 | sv->vol_id, sv->used_ebs - sv->leb_count); | |
559 | vol->corrupted = 1; | |
560 | continue; | |
561 | } | |
562 | ||
563 | vol->used_ebs = sv->used_ebs; | |
564 | vol->used_bytes = (vol->used_ebs - 1) * vol->usable_leb_size; | |
565 | vol->used_bytes += sv->last_data_size; | |
566 | vol->last_eb_bytes = sv->last_data_size; | |
567 | } | |
568 | ||
569 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
570 | if (!vol) | |
571 | return -ENOMEM; | |
572 | ||
573 | vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; | |
574 | vol->alignment = 1; | |
575 | vol->vol_type = UBI_DYNAMIC_VOLUME; | |
576 | vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; | |
577 | memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); | |
578 | vol->usable_leb_size = ubi->leb_size; | |
579 | vol->used_ebs = vol->reserved_pebs; | |
580 | vol->last_eb_bytes = vol->reserved_pebs; | |
581 | vol->used_bytes = vol->used_ebs * (ubi->leb_size - vol->data_pad); | |
582 | vol->vol_id = UBI_LAYOUT_VOL_ID; | |
583 | ||
584 | ubi_assert(!ubi->volumes[i]); | |
585 | ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; | |
586 | reserved_pebs += vol->reserved_pebs; | |
587 | ubi->vol_count += 1; | |
588 | vol->ubi = ubi; | |
589 | ||
590 | if (reserved_pebs > ubi->avail_pebs) | |
591 | ubi_err("not enough PEBs, required %d, available %d", | |
592 | reserved_pebs, ubi->avail_pebs); | |
593 | ubi->rsvd_pebs += reserved_pebs; | |
594 | ubi->avail_pebs -= reserved_pebs; | |
595 | ||
596 | return 0; | |
597 | } | |
598 | ||
599 | /** | |
600 | * check_sv - check volume scanning information. | |
601 | * @vol: UBI volume description object | |
602 | * @sv: volume scanning information | |
603 | * | |
604 | * This function returns zero if the volume scanning information is consistent | |
605 | * to the data read from the volume tabla, and %-EINVAL if not. | |
606 | */ | |
607 | static int check_sv(const struct ubi_volume *vol, | |
608 | const struct ubi_scan_volume *sv) | |
609 | { | |
610 | if (sv->highest_lnum >= vol->reserved_pebs) { | |
611 | dbg_err("bad highest_lnum"); | |
612 | goto bad; | |
613 | } | |
614 | if (sv->leb_count > vol->reserved_pebs) { | |
615 | dbg_err("bad leb_count"); | |
616 | goto bad; | |
617 | } | |
618 | if (sv->vol_type != vol->vol_type) { | |
619 | dbg_err("bad vol_type"); | |
620 | goto bad; | |
621 | } | |
622 | if (sv->used_ebs > vol->reserved_pebs) { | |
623 | dbg_err("bad used_ebs"); | |
624 | goto bad; | |
625 | } | |
626 | if (sv->data_pad != vol->data_pad) { | |
627 | dbg_err("bad data_pad"); | |
628 | goto bad; | |
629 | } | |
630 | return 0; | |
631 | ||
632 | bad: | |
633 | ubi_err("bad scanning information"); | |
634 | ubi_dbg_dump_sv(sv); | |
635 | ubi_dbg_dump_vol_info(vol); | |
636 | return -EINVAL; | |
637 | } | |
638 | ||
639 | /** | |
640 | * check_scanning_info - check that scanning information. | |
641 | * @ubi: UBI device description object | |
642 | * @si: scanning information | |
643 | * | |
644 | * Even though we protect on-flash data by CRC checksums, we still don't trust | |
645 | * the media. This function ensures that scanning information is consistent to | |
646 | * the information read from the volume table. Returns zero if the scanning | |
647 | * information is OK and %-EINVAL if it is not. | |
648 | */ | |
649 | static int check_scanning_info(const struct ubi_device *ubi, | |
650 | struct ubi_scan_info *si) | |
651 | { | |
652 | int err, i; | |
653 | struct ubi_scan_volume *sv; | |
654 | struct ubi_volume *vol; | |
655 | ||
656 | if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { | |
657 | ubi_err("scanning found %d volumes, maximum is %d + %d", | |
658 | si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); | |
659 | return -EINVAL; | |
660 | } | |
661 | ||
662 | if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&& | |
663 | si->highest_vol_id < UBI_INTERNAL_VOL_START) { | |
664 | ubi_err("too large volume ID %d found by scanning", | |
665 | si->highest_vol_id); | |
666 | return -EINVAL; | |
667 | } | |
668 | ||
669 | ||
670 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { | |
671 | cond_resched(); | |
672 | ||
673 | sv = ubi_scan_find_sv(si, i); | |
674 | vol = ubi->volumes[i]; | |
675 | if (!vol) { | |
676 | if (sv) | |
677 | ubi_scan_rm_volume(si, sv); | |
678 | continue; | |
679 | } | |
680 | ||
681 | if (vol->reserved_pebs == 0) { | |
682 | ubi_assert(i < ubi->vtbl_slots); | |
683 | ||
684 | if (!sv) | |
685 | continue; | |
686 | ||
687 | /* | |
688 | * During scanning we found a volume which does not | |
689 | * exist according to the information in the volume | |
690 | * table. This must have happened due to an unclean | |
691 | * reboot while the volume was being removed. Discard | |
692 | * these eraseblocks. | |
693 | */ | |
694 | ubi_msg("finish volume %d removal", sv->vol_id); | |
695 | ubi_scan_rm_volume(si, sv); | |
696 | } else if (sv) { | |
697 | err = check_sv(vol, sv); | |
698 | if (err) | |
699 | return err; | |
700 | } | |
701 | } | |
702 | ||
703 | return 0; | |
704 | } | |
705 | ||
706 | /** | |
707 | * ubi_read_volume_table - read volume table. | |
708 | * information. | |
709 | * @ubi: UBI device description object | |
710 | * @si: scanning information | |
711 | * | |
712 | * This function reads volume table, checks it, recover from errors if needed, | |
713 | * or creates it if needed. Returns zero in case of success and a negative | |
714 | * error code in case of failure. | |
715 | */ | |
716 | int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si) | |
717 | { | |
718 | int i, err; | |
719 | struct ubi_scan_volume *sv; | |
720 | ||
721 | empty_vtbl_record.crc = cpu_to_ubi32(0xf116c36b); | |
722 | ||
723 | /* | |
724 | * The number of supported volumes is limited by the eraseblock size | |
725 | * and by the UBI_MAX_VOLUMES constant. | |
726 | */ | |
727 | ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; | |
728 | if (ubi->vtbl_slots > UBI_MAX_VOLUMES) | |
729 | ubi->vtbl_slots = UBI_MAX_VOLUMES; | |
730 | ||
731 | ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; | |
732 | ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); | |
733 | ||
734 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); | |
735 | if (!sv) { | |
736 | /* | |
737 | * No logical eraseblocks belonging to the layout volume were | |
738 | * found. This could mean that the flash is just empty. In | |
739 | * this case we create empty layout volume. | |
740 | * | |
741 | * But if flash is not empty this must be a corruption or the | |
742 | * MTD device just contains garbage. | |
743 | */ | |
744 | if (si->is_empty) { | |
745 | ubi->vtbl = create_empty_lvol(ubi, si); | |
746 | if (IS_ERR(ubi->vtbl)) | |
747 | return PTR_ERR(ubi->vtbl); | |
748 | } else { | |
749 | ubi_err("the layout volume was not found"); | |
750 | return -EINVAL; | |
751 | } | |
752 | } else { | |
753 | if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) { | |
754 | /* This must not happen with proper UBI images */ | |
755 | dbg_err("too many LEBs (%d) in layout volume", | |
756 | sv->leb_count); | |
757 | return -EINVAL; | |
758 | } | |
759 | ||
760 | ubi->vtbl = process_lvol(ubi, si, sv); | |
761 | if (IS_ERR(ubi->vtbl)) | |
762 | return PTR_ERR(ubi->vtbl); | |
763 | } | |
764 | ||
765 | ubi->avail_pebs = ubi->good_peb_count; | |
766 | ||
767 | /* | |
768 | * The layout volume is OK, initialize the corresponding in-RAM data | |
769 | * structures. | |
770 | */ | |
771 | err = init_volumes(ubi, si, ubi->vtbl); | |
772 | if (err) | |
773 | goto out_free; | |
774 | ||
775 | /* | |
776 | * Get sure that the scanning information is consistent to the | |
777 | * information stored in the volume table. | |
778 | */ | |
779 | err = check_scanning_info(ubi, si); | |
780 | if (err) | |
781 | goto out_free; | |
782 | ||
783 | return 0; | |
784 | ||
785 | out_free: | |
786 | kfree(ubi->vtbl); | |
787 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) | |
788 | if (ubi->volumes[i]) { | |
789 | kfree(ubi->volumes[i]); | |
790 | ubi->volumes[i] = NULL; | |
791 | } | |
792 | return err; | |
793 | } | |
794 | ||
795 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
796 | ||
797 | /** | |
798 | * paranoid_vtbl_check - check volume table. | |
799 | * @ubi: UBI device description object | |
800 | */ | |
801 | static void paranoid_vtbl_check(const struct ubi_device *ubi) | |
802 | { | |
803 | if (vtbl_check(ubi, ubi->vtbl)) { | |
804 | ubi_err("paranoid check failed"); | |
805 | BUG(); | |
806 | } | |
807 | } | |
808 | ||
809 | #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ |