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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); | |
3261ebd7 | 96 | vtbl_rec->crc = cpu_to_be32(crc); |
801c135c AB |
97 | } |
98 | ||
801c135c AB |
99 | mutex_lock(&ubi->vtbl_mutex); |
100 | memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record)); | |
101 | for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) { | |
102 | err = ubi_eba_unmap_leb(ubi, UBI_LAYOUT_VOL_ID, i); | |
103 | if (err) { | |
104 | mutex_unlock(&ubi->vtbl_mutex); | |
105 | return err; | |
106 | } | |
107 | err = ubi_eba_write_leb(ubi, UBI_LAYOUT_VOL_ID, i, ubi->vtbl, 0, | |
108 | ubi->vtbl_size, UBI_LONGTERM); | |
109 | if (err) { | |
110 | mutex_unlock(&ubi->vtbl_mutex); | |
111 | return err; | |
112 | } | |
113 | } | |
114 | ||
115 | paranoid_vtbl_check(ubi); | |
116 | mutex_unlock(&ubi->vtbl_mutex); | |
117 | return ubi_wl_flush(ubi); | |
118 | } | |
119 | ||
120 | /** | |
121 | * vol_til_check - check if volume table is not corrupted and contains sensible | |
122 | * data. | |
123 | * | |
124 | * @ubi: UBI device description object | |
125 | * @vtbl: volume table | |
126 | * | |
127 | * This function returns zero if @vtbl is all right, %1 if CRC is incorrect, | |
128 | * and %-EINVAL if it contains inconsistent data. | |
129 | */ | |
130 | static int vtbl_check(const struct ubi_device *ubi, | |
131 | const struct ubi_vtbl_record *vtbl) | |
132 | { | |
133 | int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len; | |
134 | int upd_marker; | |
135 | uint32_t crc; | |
136 | const char *name; | |
137 | ||
138 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
139 | cond_resched(); | |
140 | ||
3261ebd7 CH |
141 | reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); |
142 | alignment = be32_to_cpu(vtbl[i].alignment); | |
143 | data_pad = be32_to_cpu(vtbl[i].data_pad); | |
801c135c AB |
144 | upd_marker = vtbl[i].upd_marker; |
145 | vol_type = vtbl[i].vol_type; | |
3261ebd7 | 146 | name_len = be16_to_cpu(vtbl[i].name_len); |
801c135c AB |
147 | name = &vtbl[i].name[0]; |
148 | ||
149 | crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC); | |
3261ebd7 | 150 | if (be32_to_cpu(vtbl[i].crc) != crc) { |
801c135c | 151 | ubi_err("bad CRC at record %u: %#08x, not %#08x", |
3261ebd7 | 152 | i, crc, be32_to_cpu(vtbl[i].crc)); |
801c135c AB |
153 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); |
154 | return 1; | |
155 | } | |
156 | ||
157 | if (reserved_pebs == 0) { | |
158 | if (memcmp(&vtbl[i], &empty_vtbl_record, | |
159 | UBI_VTBL_RECORD_SIZE)) { | |
160 | dbg_err("bad empty record"); | |
161 | goto bad; | |
162 | } | |
163 | continue; | |
164 | } | |
165 | ||
166 | if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 || | |
167 | name_len < 0) { | |
168 | dbg_err("negative values"); | |
169 | goto bad; | |
170 | } | |
171 | ||
172 | if (alignment > ubi->leb_size || alignment == 0) { | |
173 | dbg_err("bad alignment"); | |
174 | goto bad; | |
175 | } | |
176 | ||
177 | n = alignment % ubi->min_io_size; | |
178 | if (alignment != 1 && n) { | |
179 | dbg_err("alignment is not multiple of min I/O unit"); | |
180 | goto bad; | |
181 | } | |
182 | ||
183 | n = ubi->leb_size % alignment; | |
184 | if (data_pad != n) { | |
185 | dbg_err("bad data_pad, has to be %d", n); | |
186 | goto bad; | |
187 | } | |
188 | ||
189 | if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) { | |
190 | dbg_err("bad vol_type"); | |
191 | goto bad; | |
192 | } | |
193 | ||
194 | if (upd_marker != 0 && upd_marker != 1) { | |
195 | dbg_err("bad upd_marker"); | |
196 | goto bad; | |
197 | } | |
198 | ||
199 | if (reserved_pebs > ubi->good_peb_count) { | |
200 | dbg_err("too large reserved_pebs, good PEBs %d", | |
201 | ubi->good_peb_count); | |
202 | goto bad; | |
203 | } | |
204 | ||
205 | if (name_len > UBI_VOL_NAME_MAX) { | |
206 | dbg_err("too long volume name, max %d", | |
207 | UBI_VOL_NAME_MAX); | |
208 | goto bad; | |
209 | } | |
210 | ||
211 | if (name[0] == '\0') { | |
212 | dbg_err("NULL volume name"); | |
213 | goto bad; | |
214 | } | |
215 | ||
216 | if (name_len != strnlen(name, name_len + 1)) { | |
217 | dbg_err("bad name_len"); | |
218 | goto bad; | |
219 | } | |
220 | } | |
221 | ||
222 | /* Checks that all names are unique */ | |
223 | for (i = 0; i < ubi->vtbl_slots - 1; i++) { | |
224 | for (n = i + 1; n < ubi->vtbl_slots; n++) { | |
3261ebd7 CH |
225 | int len1 = be16_to_cpu(vtbl[i].name_len); |
226 | int len2 = be16_to_cpu(vtbl[n].name_len); | |
801c135c AB |
227 | |
228 | if (len1 > 0 && len1 == len2 && | |
229 | !strncmp(vtbl[i].name, vtbl[n].name, len1)) { | |
230 | ubi_err("volumes %d and %d have the same name" | |
231 | " \"%s\"", i, n, vtbl[i].name); | |
232 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
233 | ubi_dbg_dump_vtbl_record(&vtbl[n], n); | |
234 | return -EINVAL; | |
235 | } | |
236 | } | |
237 | } | |
238 | ||
239 | return 0; | |
240 | ||
241 | bad: | |
242 | ubi_err("volume table check failed, record %d", i); | |
243 | ubi_dbg_dump_vtbl_record(&vtbl[i], i); | |
244 | return -EINVAL; | |
245 | } | |
246 | ||
247 | /** | |
248 | * create_vtbl - create a copy of volume table. | |
249 | * @ubi: UBI device description object | |
250 | * @si: scanning information | |
251 | * @copy: number of the volume table copy | |
252 | * @vtbl: contents of the volume table | |
253 | * | |
254 | * This function returns zero in case of success and a negative error code in | |
255 | * case of failure. | |
256 | */ | |
e88d6e10 | 257 | static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si, |
801c135c AB |
258 | int copy, void *vtbl) |
259 | { | |
260 | int err, tries = 0; | |
261 | static struct ubi_vid_hdr *vid_hdr; | |
262 | struct ubi_scan_volume *sv; | |
263 | struct ubi_scan_leb *new_seb, *old_seb = NULL; | |
264 | ||
265 | ubi_msg("create volume table (copy #%d)", copy + 1); | |
266 | ||
33818bbb | 267 | vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); |
801c135c AB |
268 | if (!vid_hdr) |
269 | return -ENOMEM; | |
270 | ||
271 | /* | |
272 | * Check if there is a logical eraseblock which would have to contain | |
273 | * this volume table copy was found during scanning. It has to be wiped | |
274 | * out. | |
275 | */ | |
276 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); | |
277 | if (sv) | |
278 | old_seb = ubi_scan_find_seb(sv, copy); | |
279 | ||
280 | retry: | |
281 | new_seb = ubi_scan_get_free_peb(ubi, si); | |
282 | if (IS_ERR(new_seb)) { | |
283 | err = PTR_ERR(new_seb); | |
284 | goto out_free; | |
285 | } | |
286 | ||
287 | vid_hdr->vol_type = UBI_VID_DYNAMIC; | |
3261ebd7 | 288 | vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOL_ID); |
801c135c AB |
289 | vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT; |
290 | vid_hdr->data_size = vid_hdr->used_ebs = | |
3261ebd7 CH |
291 | vid_hdr->data_pad = cpu_to_be32(0); |
292 | vid_hdr->lnum = cpu_to_be32(copy); | |
293 | vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum); | |
294 | vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0); | |
801c135c AB |
295 | |
296 | /* The EC header is already there, write the VID header */ | |
297 | err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr); | |
298 | if (err) | |
299 | goto write_error; | |
300 | ||
301 | /* Write the layout volume contents */ | |
302 | err = ubi_io_write_data(ubi, vtbl, new_seb->pnum, 0, ubi->vtbl_size); | |
303 | if (err) | |
304 | goto write_error; | |
305 | ||
306 | /* | |
307 | * And add it to the scanning information. Don't delete the old | |
308 | * @old_seb as it will be deleted and freed in 'ubi_scan_add_used()'. | |
309 | */ | |
310 | err = ubi_scan_add_used(ubi, si, new_seb->pnum, new_seb->ec, | |
311 | vid_hdr, 0); | |
312 | kfree(new_seb); | |
313 | ubi_free_vid_hdr(ubi, vid_hdr); | |
314 | return err; | |
315 | ||
316 | write_error: | |
78d87c95 AB |
317 | if (err == -EIO && ++tries <= 5) { |
318 | /* | |
319 | * Probably this physical eraseblock went bad, try to pick | |
320 | * another one. | |
321 | */ | |
322 | list_add_tail(&new_seb->u.list, &si->corr); | |
c4e90ec0 | 323 | goto retry; |
78d87c95 AB |
324 | } |
325 | kfree(new_seb); | |
801c135c AB |
326 | out_free: |
327 | ubi_free_vid_hdr(ubi, vid_hdr); | |
328 | return err; | |
329 | ||
330 | } | |
331 | ||
332 | /** | |
333 | * process_lvol - process the layout volume. | |
334 | * @ubi: UBI device description object | |
335 | * @si: scanning information | |
336 | * @sv: layout volume scanning information | |
337 | * | |
338 | * This function is responsible for reading the layout volume, ensuring it is | |
339 | * not corrupted, and recovering from corruptions if needed. Returns volume | |
340 | * table in case of success and a negative error code in case of failure. | |
341 | */ | |
e88d6e10 | 342 | static struct ubi_vtbl_record *process_lvol(struct ubi_device *ubi, |
801c135c AB |
343 | struct ubi_scan_info *si, |
344 | struct ubi_scan_volume *sv) | |
345 | { | |
346 | int err; | |
347 | struct rb_node *rb; | |
348 | struct ubi_scan_leb *seb; | |
349 | struct ubi_vtbl_record *leb[UBI_LAYOUT_VOLUME_EBS] = { NULL, NULL }; | |
350 | int leb_corrupted[UBI_LAYOUT_VOLUME_EBS] = {1, 1}; | |
351 | ||
352 | /* | |
353 | * UBI goes through the following steps when it changes the layout | |
354 | * volume: | |
355 | * a. erase LEB 0; | |
356 | * b. write new data to LEB 0; | |
357 | * c. erase LEB 1; | |
358 | * d. write new data to LEB 1. | |
359 | * | |
360 | * Before the change, both LEBs contain the same data. | |
361 | * | |
362 | * Due to unclean reboots, the contents of LEB 0 may be lost, but there | |
363 | * should LEB 1. So it is OK if LEB 0 is corrupted while LEB 1 is not. | |
364 | * Similarly, LEB 1 may be lost, but there should be LEB 0. And | |
365 | * finally, unclean reboots may result in a situation when neither LEB | |
366 | * 0 nor LEB 1 are corrupted, but they are different. In this case, LEB | |
367 | * 0 contains more recent information. | |
368 | * | |
369 | * So the plan is to first check LEB 0. Then | |
370 | * a. if LEB 0 is OK, it must be containing the most resent data; then | |
371 | * we compare it with LEB 1, and if they are different, we copy LEB | |
372 | * 0 to LEB 1; | |
373 | * b. if LEB 0 is corrupted, but LEB 1 has to be OK, and we copy LEB 1 | |
374 | * to LEB 0. | |
375 | */ | |
376 | ||
377 | dbg_msg("check layout volume"); | |
378 | ||
379 | /* Read both LEB 0 and LEB 1 into memory */ | |
380 | ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) { | |
92ad8f37 | 381 | leb[seb->lnum] = vmalloc(ubi->vtbl_size); |
801c135c AB |
382 | if (!leb[seb->lnum]) { |
383 | err = -ENOMEM; | |
384 | goto out_free; | |
385 | } | |
92ad8f37 | 386 | memset(leb[seb->lnum], 0, ubi->vtbl_size); |
801c135c AB |
387 | |
388 | err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0, | |
389 | ubi->vtbl_size); | |
390 | if (err == UBI_IO_BITFLIPS || err == -EBADMSG) | |
391 | /* Scrub the PEB later */ | |
392 | seb->scrub = 1; | |
393 | else if (err) | |
394 | goto out_free; | |
395 | } | |
396 | ||
397 | err = -EINVAL; | |
398 | if (leb[0]) { | |
399 | leb_corrupted[0] = vtbl_check(ubi, leb[0]); | |
400 | if (leb_corrupted[0] < 0) | |
401 | goto out_free; | |
402 | } | |
403 | ||
404 | if (!leb_corrupted[0]) { | |
405 | /* LEB 0 is OK */ | |
406 | if (leb[1]) | |
407 | leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size); | |
408 | if (leb_corrupted[1]) { | |
409 | ubi_warn("volume table copy #2 is corrupted"); | |
410 | err = create_vtbl(ubi, si, 1, leb[0]); | |
411 | if (err) | |
412 | goto out_free; | |
413 | ubi_msg("volume table was restored"); | |
414 | } | |
415 | ||
416 | /* Both LEB 1 and LEB 2 are OK and consistent */ | |
92ad8f37 | 417 | vfree(leb[1]); |
801c135c AB |
418 | return leb[0]; |
419 | } else { | |
420 | /* LEB 0 is corrupted or does not exist */ | |
421 | if (leb[1]) { | |
422 | leb_corrupted[1] = vtbl_check(ubi, leb[1]); | |
423 | if (leb_corrupted[1] < 0) | |
424 | goto out_free; | |
425 | } | |
426 | if (leb_corrupted[1]) { | |
427 | /* Both LEB 0 and LEB 1 are corrupted */ | |
428 | ubi_err("both volume tables are corrupted"); | |
429 | goto out_free; | |
430 | } | |
431 | ||
432 | ubi_warn("volume table copy #1 is corrupted"); | |
433 | err = create_vtbl(ubi, si, 0, leb[1]); | |
434 | if (err) | |
435 | goto out_free; | |
436 | ubi_msg("volume table was restored"); | |
437 | ||
92ad8f37 | 438 | vfree(leb[0]); |
801c135c AB |
439 | return leb[1]; |
440 | } | |
441 | ||
442 | out_free: | |
92ad8f37 AB |
443 | vfree(leb[0]); |
444 | vfree(leb[1]); | |
801c135c AB |
445 | return ERR_PTR(err); |
446 | } | |
447 | ||
448 | /** | |
449 | * create_empty_lvol - create empty layout volume. | |
450 | * @ubi: UBI device description object | |
451 | * @si: scanning information | |
452 | * | |
453 | * This function returns volume table contents in case of success and a | |
454 | * negative error code in case of failure. | |
455 | */ | |
e88d6e10 | 456 | static struct ubi_vtbl_record *create_empty_lvol(struct ubi_device *ubi, |
801c135c AB |
457 | struct ubi_scan_info *si) |
458 | { | |
459 | int i; | |
460 | struct ubi_vtbl_record *vtbl; | |
461 | ||
92ad8f37 | 462 | vtbl = vmalloc(ubi->vtbl_size); |
801c135c AB |
463 | if (!vtbl) |
464 | return ERR_PTR(-ENOMEM); | |
92ad8f37 | 465 | memset(vtbl, 0, ubi->vtbl_size); |
801c135c AB |
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) { | |
92ad8f37 | 475 | vfree(vtbl); |
801c135c AB |
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 | ||
3261ebd7 | 503 | if (be32_to_cpu(vtbl[i].reserved_pebs) == 0) |
801c135c AB |
504 | continue; /* Empty record */ |
505 | ||
506 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
507 | if (!vol) | |
508 | return -ENOMEM; | |
509 | ||
3261ebd7 CH |
510 | vol->reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs); |
511 | vol->alignment = be32_to_cpu(vtbl[i].alignment); | |
512 | vol->data_pad = be32_to_cpu(vtbl[i].data_pad); | |
801c135c AB |
513 | vol->vol_type = vtbl[i].vol_type == UBI_VID_DYNAMIC ? |
514 | UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; | |
3261ebd7 | 515 | vol->name_len = be16_to_cpu(vtbl[i].name_len); |
801c135c AB |
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; | |
d08c3b78 VA |
534 | vol->used_bytes = |
535 | (long long)vol->used_ebs * vol->usable_leb_size; | |
801c135c AB |
536 | continue; |
537 | } | |
538 | ||
539 | /* Static volumes only */ | |
540 | sv = ubi_scan_find_sv(si, i); | |
541 | if (!sv) { | |
542 | /* | |
543 | * No eraseblocks belonging to this volume found. We | |
544 | * don't actually know whether this static volume is | |
545 | * completely corrupted or just contains no data. And | |
546 | * we cannot know this as long as data size is not | |
547 | * stored on flash. So we just assume the volume is | |
548 | * empty. FIXME: this should be handled. | |
549 | */ | |
550 | continue; | |
551 | } | |
552 | ||
553 | if (sv->leb_count != sv->used_ebs) { | |
554 | /* | |
555 | * We found a static volume which misses several | |
556 | * eraseblocks. Treat it as corrupted. | |
557 | */ | |
558 | ubi_warn("static volume %d misses %d LEBs - corrupted", | |
559 | sv->vol_id, sv->used_ebs - sv->leb_count); | |
560 | vol->corrupted = 1; | |
561 | continue; | |
562 | } | |
563 | ||
564 | vol->used_ebs = sv->used_ebs; | |
d08c3b78 VA |
565 | vol->used_bytes = |
566 | (long long)(vol->used_ebs - 1) * vol->usable_leb_size; | |
801c135c AB |
567 | vol->used_bytes += sv->last_data_size; |
568 | vol->last_eb_bytes = sv->last_data_size; | |
569 | } | |
570 | ||
571 | vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL); | |
572 | if (!vol) | |
573 | return -ENOMEM; | |
574 | ||
575 | vol->reserved_pebs = UBI_LAYOUT_VOLUME_EBS; | |
576 | vol->alignment = 1; | |
577 | vol->vol_type = UBI_DYNAMIC_VOLUME; | |
578 | vol->name_len = sizeof(UBI_LAYOUT_VOLUME_NAME) - 1; | |
579 | memcpy(vol->name, UBI_LAYOUT_VOLUME_NAME, vol->name_len + 1); | |
580 | vol->usable_leb_size = ubi->leb_size; | |
581 | vol->used_ebs = vol->reserved_pebs; | |
582 | vol->last_eb_bytes = vol->reserved_pebs; | |
d08c3b78 VA |
583 | vol->used_bytes = |
584 | (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad); | |
801c135c AB |
585 | vol->vol_id = UBI_LAYOUT_VOL_ID; |
586 | ||
587 | ubi_assert(!ubi->volumes[i]); | |
588 | ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol; | |
589 | reserved_pebs += vol->reserved_pebs; | |
590 | ubi->vol_count += 1; | |
591 | vol->ubi = ubi; | |
592 | ||
593 | if (reserved_pebs > ubi->avail_pebs) | |
594 | ubi_err("not enough PEBs, required %d, available %d", | |
595 | reserved_pebs, ubi->avail_pebs); | |
596 | ubi->rsvd_pebs += reserved_pebs; | |
597 | ubi->avail_pebs -= reserved_pebs; | |
598 | ||
599 | return 0; | |
600 | } | |
601 | ||
602 | /** | |
603 | * check_sv - check volume scanning information. | |
604 | * @vol: UBI volume description object | |
605 | * @sv: volume scanning information | |
606 | * | |
607 | * This function returns zero if the volume scanning information is consistent | |
608 | * to the data read from the volume tabla, and %-EINVAL if not. | |
609 | */ | |
610 | static int check_sv(const struct ubi_volume *vol, | |
611 | const struct ubi_scan_volume *sv) | |
612 | { | |
613 | if (sv->highest_lnum >= vol->reserved_pebs) { | |
614 | dbg_err("bad highest_lnum"); | |
615 | goto bad; | |
616 | } | |
617 | if (sv->leb_count > vol->reserved_pebs) { | |
618 | dbg_err("bad leb_count"); | |
619 | goto bad; | |
620 | } | |
621 | if (sv->vol_type != vol->vol_type) { | |
622 | dbg_err("bad vol_type"); | |
623 | goto bad; | |
624 | } | |
625 | if (sv->used_ebs > vol->reserved_pebs) { | |
626 | dbg_err("bad used_ebs"); | |
627 | goto bad; | |
628 | } | |
629 | if (sv->data_pad != vol->data_pad) { | |
630 | dbg_err("bad data_pad"); | |
631 | goto bad; | |
632 | } | |
633 | return 0; | |
634 | ||
635 | bad: | |
636 | ubi_err("bad scanning information"); | |
637 | ubi_dbg_dump_sv(sv); | |
638 | ubi_dbg_dump_vol_info(vol); | |
639 | return -EINVAL; | |
640 | } | |
641 | ||
642 | /** | |
643 | * check_scanning_info - check that scanning information. | |
644 | * @ubi: UBI device description object | |
645 | * @si: scanning information | |
646 | * | |
647 | * Even though we protect on-flash data by CRC checksums, we still don't trust | |
648 | * the media. This function ensures that scanning information is consistent to | |
649 | * the information read from the volume table. Returns zero if the scanning | |
650 | * information is OK and %-EINVAL if it is not. | |
651 | */ | |
652 | static int check_scanning_info(const struct ubi_device *ubi, | |
653 | struct ubi_scan_info *si) | |
654 | { | |
655 | int err, i; | |
656 | struct ubi_scan_volume *sv; | |
657 | struct ubi_volume *vol; | |
658 | ||
659 | if (si->vols_found > UBI_INT_VOL_COUNT + ubi->vtbl_slots) { | |
660 | ubi_err("scanning found %d volumes, maximum is %d + %d", | |
661 | si->vols_found, UBI_INT_VOL_COUNT, ubi->vtbl_slots); | |
662 | return -EINVAL; | |
663 | } | |
664 | ||
665 | if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&& | |
666 | si->highest_vol_id < UBI_INTERNAL_VOL_START) { | |
667 | ubi_err("too large volume ID %d found by scanning", | |
668 | si->highest_vol_id); | |
669 | return -EINVAL; | |
670 | } | |
671 | ||
672 | ||
673 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { | |
674 | cond_resched(); | |
675 | ||
676 | sv = ubi_scan_find_sv(si, i); | |
677 | vol = ubi->volumes[i]; | |
678 | if (!vol) { | |
679 | if (sv) | |
680 | ubi_scan_rm_volume(si, sv); | |
681 | continue; | |
682 | } | |
683 | ||
684 | if (vol->reserved_pebs == 0) { | |
685 | ubi_assert(i < ubi->vtbl_slots); | |
686 | ||
687 | if (!sv) | |
688 | continue; | |
689 | ||
690 | /* | |
691 | * During scanning we found a volume which does not | |
692 | * exist according to the information in the volume | |
693 | * table. This must have happened due to an unclean | |
694 | * reboot while the volume was being removed. Discard | |
695 | * these eraseblocks. | |
696 | */ | |
697 | ubi_msg("finish volume %d removal", sv->vol_id); | |
698 | ubi_scan_rm_volume(si, sv); | |
699 | } else if (sv) { | |
700 | err = check_sv(vol, sv); | |
701 | if (err) | |
702 | return err; | |
703 | } | |
704 | } | |
705 | ||
706 | return 0; | |
707 | } | |
708 | ||
709 | /** | |
710 | * ubi_read_volume_table - read volume table. | |
711 | * information. | |
712 | * @ubi: UBI device description object | |
713 | * @si: scanning information | |
714 | * | |
715 | * This function reads volume table, checks it, recover from errors if needed, | |
716 | * or creates it if needed. Returns zero in case of success and a negative | |
717 | * error code in case of failure. | |
718 | */ | |
719 | int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si) | |
720 | { | |
721 | int i, err; | |
722 | struct ubi_scan_volume *sv; | |
723 | ||
3261ebd7 | 724 | empty_vtbl_record.crc = cpu_to_be32(0xf116c36b); |
801c135c AB |
725 | |
726 | /* | |
727 | * The number of supported volumes is limited by the eraseblock size | |
728 | * and by the UBI_MAX_VOLUMES constant. | |
729 | */ | |
730 | ubi->vtbl_slots = ubi->leb_size / UBI_VTBL_RECORD_SIZE; | |
731 | if (ubi->vtbl_slots > UBI_MAX_VOLUMES) | |
732 | ubi->vtbl_slots = UBI_MAX_VOLUMES; | |
733 | ||
734 | ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE; | |
735 | ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size); | |
736 | ||
737 | sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID); | |
738 | if (!sv) { | |
739 | /* | |
740 | * No logical eraseblocks belonging to the layout volume were | |
741 | * found. This could mean that the flash is just empty. In | |
742 | * this case we create empty layout volume. | |
743 | * | |
744 | * But if flash is not empty this must be a corruption or the | |
745 | * MTD device just contains garbage. | |
746 | */ | |
747 | if (si->is_empty) { | |
748 | ubi->vtbl = create_empty_lvol(ubi, si); | |
749 | if (IS_ERR(ubi->vtbl)) | |
750 | return PTR_ERR(ubi->vtbl); | |
751 | } else { | |
752 | ubi_err("the layout volume was not found"); | |
753 | return -EINVAL; | |
754 | } | |
755 | } else { | |
756 | if (sv->leb_count > UBI_LAYOUT_VOLUME_EBS) { | |
757 | /* This must not happen with proper UBI images */ | |
758 | dbg_err("too many LEBs (%d) in layout volume", | |
759 | sv->leb_count); | |
760 | return -EINVAL; | |
761 | } | |
762 | ||
763 | ubi->vtbl = process_lvol(ubi, si, sv); | |
764 | if (IS_ERR(ubi->vtbl)) | |
765 | return PTR_ERR(ubi->vtbl); | |
766 | } | |
767 | ||
768 | ubi->avail_pebs = ubi->good_peb_count; | |
769 | ||
770 | /* | |
771 | * The layout volume is OK, initialize the corresponding in-RAM data | |
772 | * structures. | |
773 | */ | |
774 | err = init_volumes(ubi, si, ubi->vtbl); | |
775 | if (err) | |
776 | goto out_free; | |
777 | ||
778 | /* | |
779 | * Get sure that the scanning information is consistent to the | |
780 | * information stored in the volume table. | |
781 | */ | |
782 | err = check_scanning_info(ubi, si); | |
783 | if (err) | |
784 | goto out_free; | |
785 | ||
786 | return 0; | |
787 | ||
788 | out_free: | |
92ad8f37 | 789 | vfree(ubi->vtbl); |
801c135c AB |
790 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) |
791 | if (ubi->volumes[i]) { | |
792 | kfree(ubi->volumes[i]); | |
793 | ubi->volumes[i] = NULL; | |
794 | } | |
795 | return err; | |
796 | } | |
797 | ||
798 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
799 | ||
800 | /** | |
801 | * paranoid_vtbl_check - check volume table. | |
802 | * @ubi: UBI device description object | |
803 | */ | |
804 | static void paranoid_vtbl_check(const struct ubi_device *ubi) | |
805 | { | |
806 | if (vtbl_check(ubi, ubi->vtbl)) { | |
807 | ubi_err("paranoid check failed"); | |
808 | BUG(); | |
809 | } | |
810 | } | |
811 | ||
812 | #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ |