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801c135c AB |
1 | /* |
2 | * Copyright (c) International Business Machines Corp., 2006 | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | |
12 | * the GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | * | |
18 | * Author: Artem Bityutskiy (Битюцкий Артём) | |
19 | */ | |
20 | ||
21 | /* | |
85c6e6e2 | 22 | * UBI scanning sub-system. |
801c135c | 23 | * |
85c6e6e2 | 24 | * This sub-system is responsible for scanning the flash media, checking UBI |
801c135c AB |
25 | * headers and providing complete information about the UBI flash image. |
26 | * | |
78d87c95 | 27 | * The scanning information is represented by a &struct ubi_scan_info' object. |
801c135c AB |
28 | * Information about found volumes is represented by &struct ubi_scan_volume |
29 | * objects which are kept in volume RB-tree with root at the @volumes field. | |
30 | * The RB-tree is indexed by the volume ID. | |
31 | * | |
0525dac9 | 32 | * Scanned logical eraseblocks are represented by &struct ubi_scan_leb objects. |
801c135c AB |
33 | * These objects are kept in per-volume RB-trees with the root at the |
34 | * corresponding &struct ubi_scan_volume object. To put it differently, we keep | |
35 | * an RB-tree of per-volume objects and each of these objects is the root of | |
36 | * RB-tree of per-eraseblock objects. | |
37 | * | |
38 | * Corrupted physical eraseblocks are put to the @corr list, free physical | |
39 | * eraseblocks are put to the @free list and the physical eraseblock to be | |
40 | * erased are put to the @erase list. | |
0525dac9 AB |
41 | * |
42 | * UBI tries to distinguish between 2 types of corruptions. | |
43 | * 1. Corruptions caused by power cuts. These are harmless and expected | |
44 | * corruptions and UBI tries to handle them gracefully, without printing too | |
45 | * many warnings and error messages. The idea is that we do not lose | |
46 | * important data in these case - we may lose only the data which was being | |
47 | * written to the media just before the power cut happened, and the upper | |
48 | * layers are supposed to handle these situations. UBI puts these PEBs to | |
49 | * the head of the @erase list and they are scheduled for erasure. | |
50 | * | |
51 | * 2. Unexpected corruptions which are not caused by power cuts. During | |
52 | * scanning, such PEBs are put to the @corr list and UBI preserves them. | |
53 | * Obviously, this lessens the amount of available PEBs, and if at some | |
54 | * point UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly | |
55 | * informs about such PEBs every time the MTD device is attached. | |
801c135c AB |
56 | */ |
57 | ||
58 | #include <linux/err.h> | |
5a0e3ad6 | 59 | #include <linux/slab.h> |
801c135c | 60 | #include <linux/crc32.h> |
3013ee31 | 61 | #include <linux/math64.h> |
095751a6 | 62 | #include <linux/random.h> |
801c135c AB |
63 | #include "ubi.h" |
64 | ||
65 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
e88d6e10 | 66 | static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si); |
801c135c AB |
67 | #else |
68 | #define paranoid_check_si(ubi, si) 0 | |
69 | #endif | |
70 | ||
71 | /* Temporary variables used during scanning */ | |
72 | static struct ubi_ec_hdr *ech; | |
73 | static struct ubi_vid_hdr *vidh; | |
74 | ||
941dfb07 | 75 | /** |
78d87c95 AB |
76 | * add_to_list - add physical eraseblock to a list. |
77 | * @si: scanning information | |
78 | * @pnum: physical eraseblock number to add | |
79 | * @ec: erase counter of the physical eraseblock | |
0525dac9 | 80 | * @to_head: if not zero, add to the head of the list |
78d87c95 AB |
81 | * @list: the list to add to |
82 | * | |
3fb34124 | 83 | * This function adds physical eraseblock @pnum to free, erase, or alien lists. |
0525dac9 AB |
84 | * If @to_head is not zero, PEB will be added to the head of the list, which |
85 | * basically means it will be processed first later. E.g., we add corrupted | |
86 | * PEBs (corrupted due to power cuts) to the head of the erase list to make | |
87 | * sure we erase them first and get rid of corruptions ASAP. This function | |
88 | * returns zero in case of success and a negative error code in case of | |
3fb34124 | 89 | * failure. |
78d87c95 | 90 | */ |
0525dac9 | 91 | static int add_to_list(struct ubi_scan_info *si, int pnum, int ec, int to_head, |
78d87c95 | 92 | struct list_head *list) |
801c135c AB |
93 | { |
94 | struct ubi_scan_leb *seb; | |
95 | ||
33789fb9 | 96 | if (list == &si->free) { |
801c135c | 97 | dbg_bld("add to free: PEB %d, EC %d", pnum, ec); |
33789fb9 | 98 | } else if (list == &si->erase) { |
801c135c | 99 | dbg_bld("add to erase: PEB %d, EC %d", pnum, ec); |
33789fb9 | 100 | } else if (list == &si->alien) { |
801c135c | 101 | dbg_bld("add to alien: PEB %d, EC %d", pnum, ec); |
33789fb9 AB |
102 | si->alien_peb_count += 1; |
103 | } else | |
801c135c AB |
104 | BUG(); |
105 | ||
106 | seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); | |
107 | if (!seb) | |
108 | return -ENOMEM; | |
109 | ||
110 | seb->pnum = pnum; | |
111 | seb->ec = ec; | |
0525dac9 AB |
112 | if (to_head) |
113 | list_add(&seb->u.list, list); | |
114 | else | |
115 | list_add_tail(&seb->u.list, list); | |
801c135c AB |
116 | return 0; |
117 | } | |
118 | ||
3fb34124 AB |
119 | /** |
120 | * add_corrupted - add a corrupted physical eraseblock. | |
121 | * @si: scanning information | |
122 | * @pnum: physical eraseblock number to add | |
123 | * @ec: erase counter of the physical eraseblock | |
124 | * | |
125 | * This function adds corrupted physical eraseblock @pnum to the 'corr' list. | |
feeba4b8 AB |
126 | * The corruption was presumably not caused by a power cut. Returns zero in |
127 | * case of success and a negative error code in case of failure. | |
3fb34124 AB |
128 | */ |
129 | static int add_corrupted(struct ubi_scan_info *si, int pnum, int ec) | |
130 | { | |
131 | struct ubi_scan_leb *seb; | |
132 | ||
133 | dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec); | |
134 | ||
135 | seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); | |
136 | if (!seb) | |
137 | return -ENOMEM; | |
138 | ||
139 | si->corr_peb_count += 1; | |
140 | seb->pnum = pnum; | |
141 | seb->ec = ec; | |
142 | list_add(&seb->u.list, &si->corr); | |
143 | return 0; | |
144 | } | |
145 | ||
801c135c | 146 | /** |
ebaaf1af | 147 | * validate_vid_hdr - check volume identifier header. |
801c135c AB |
148 | * @vid_hdr: the volume identifier header to check |
149 | * @sv: information about the volume this logical eraseblock belongs to | |
150 | * @pnum: physical eraseblock number the VID header came from | |
151 | * | |
152 | * This function checks that data stored in @vid_hdr is consistent. Returns | |
153 | * non-zero if an inconsistency was found and zero if not. | |
154 | * | |
155 | * Note, UBI does sanity check of everything it reads from the flash media. | |
85c6e6e2 | 156 | * Most of the checks are done in the I/O sub-system. Here we check that the |
801c135c AB |
157 | * information in the VID header is consistent to the information in other VID |
158 | * headers of the same volume. | |
159 | */ | |
160 | static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr, | |
161 | const struct ubi_scan_volume *sv, int pnum) | |
162 | { | |
163 | int vol_type = vid_hdr->vol_type; | |
3261ebd7 CH |
164 | int vol_id = be32_to_cpu(vid_hdr->vol_id); |
165 | int used_ebs = be32_to_cpu(vid_hdr->used_ebs); | |
166 | int data_pad = be32_to_cpu(vid_hdr->data_pad); | |
801c135c AB |
167 | |
168 | if (sv->leb_count != 0) { | |
169 | int sv_vol_type; | |
170 | ||
171 | /* | |
172 | * This is not the first logical eraseblock belonging to this | |
173 | * volume. Ensure that the data in its VID header is consistent | |
174 | * to the data in previous logical eraseblock headers. | |
175 | */ | |
176 | ||
177 | if (vol_id != sv->vol_id) { | |
178 | dbg_err("inconsistent vol_id"); | |
179 | goto bad; | |
180 | } | |
181 | ||
182 | if (sv->vol_type == UBI_STATIC_VOLUME) | |
183 | sv_vol_type = UBI_VID_STATIC; | |
184 | else | |
185 | sv_vol_type = UBI_VID_DYNAMIC; | |
186 | ||
187 | if (vol_type != sv_vol_type) { | |
188 | dbg_err("inconsistent vol_type"); | |
189 | goto bad; | |
190 | } | |
191 | ||
192 | if (used_ebs != sv->used_ebs) { | |
193 | dbg_err("inconsistent used_ebs"); | |
194 | goto bad; | |
195 | } | |
196 | ||
197 | if (data_pad != sv->data_pad) { | |
198 | dbg_err("inconsistent data_pad"); | |
199 | goto bad; | |
200 | } | |
201 | } | |
202 | ||
203 | return 0; | |
204 | ||
205 | bad: | |
206 | ubi_err("inconsistent VID header at PEB %d", pnum); | |
207 | ubi_dbg_dump_vid_hdr(vid_hdr); | |
208 | ubi_dbg_dump_sv(sv); | |
209 | return -EINVAL; | |
210 | } | |
211 | ||
212 | /** | |
213 | * add_volume - add volume to the scanning information. | |
214 | * @si: scanning information | |
215 | * @vol_id: ID of the volume to add | |
216 | * @pnum: physical eraseblock number | |
217 | * @vid_hdr: volume identifier header | |
218 | * | |
219 | * If the volume corresponding to the @vid_hdr logical eraseblock is already | |
220 | * present in the scanning information, this function does nothing. Otherwise | |
221 | * it adds corresponding volume to the scanning information. Returns a pointer | |
222 | * to the scanning volume object in case of success and a negative error code | |
223 | * in case of failure. | |
224 | */ | |
225 | static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id, | |
226 | int pnum, | |
227 | const struct ubi_vid_hdr *vid_hdr) | |
228 | { | |
229 | struct ubi_scan_volume *sv; | |
230 | struct rb_node **p = &si->volumes.rb_node, *parent = NULL; | |
231 | ||
3261ebd7 | 232 | ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id)); |
801c135c AB |
233 | |
234 | /* Walk the volume RB-tree to look if this volume is already present */ | |
235 | while (*p) { | |
236 | parent = *p; | |
237 | sv = rb_entry(parent, struct ubi_scan_volume, rb); | |
238 | ||
239 | if (vol_id == sv->vol_id) | |
240 | return sv; | |
241 | ||
242 | if (vol_id > sv->vol_id) | |
243 | p = &(*p)->rb_left; | |
244 | else | |
245 | p = &(*p)->rb_right; | |
246 | } | |
247 | ||
248 | /* The volume is absent - add it */ | |
249 | sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL); | |
250 | if (!sv) | |
251 | return ERR_PTR(-ENOMEM); | |
252 | ||
253 | sv->highest_lnum = sv->leb_count = 0; | |
801c135c AB |
254 | sv->vol_id = vol_id; |
255 | sv->root = RB_ROOT; | |
3261ebd7 CH |
256 | sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs); |
257 | sv->data_pad = be32_to_cpu(vid_hdr->data_pad); | |
801c135c AB |
258 | sv->compat = vid_hdr->compat; |
259 | sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME | |
260 | : UBI_STATIC_VOLUME; | |
261 | if (vol_id > si->highest_vol_id) | |
262 | si->highest_vol_id = vol_id; | |
263 | ||
264 | rb_link_node(&sv->rb, parent, p); | |
265 | rb_insert_color(&sv->rb, &si->volumes); | |
266 | si->vols_found += 1; | |
267 | dbg_bld("added volume %d", vol_id); | |
268 | return sv; | |
269 | } | |
270 | ||
271 | /** | |
272 | * compare_lebs - find out which logical eraseblock is newer. | |
273 | * @ubi: UBI device description object | |
274 | * @seb: first logical eraseblock to compare | |
275 | * @pnum: physical eraseblock number of the second logical eraseblock to | |
276 | * compare | |
277 | * @vid_hdr: volume identifier header of the second logical eraseblock | |
278 | * | |
279 | * This function compares 2 copies of a LEB and informs which one is newer. In | |
280 | * case of success this function returns a positive value, in case of failure, a | |
281 | * negative error code is returned. The success return codes use the following | |
282 | * bits: | |
3f502622 | 283 | * o bit 0 is cleared: the first PEB (described by @seb) is newer than the |
801c135c AB |
284 | * second PEB (described by @pnum and @vid_hdr); |
285 | * o bit 0 is set: the second PEB is newer; | |
286 | * o bit 1 is cleared: no bit-flips were detected in the newer LEB; | |
287 | * o bit 1 is set: bit-flips were detected in the newer LEB; | |
288 | * o bit 2 is cleared: the older LEB is not corrupted; | |
289 | * o bit 2 is set: the older LEB is corrupted. | |
290 | */ | |
e88d6e10 AB |
291 | static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb, |
292 | int pnum, const struct ubi_vid_hdr *vid_hdr) | |
801c135c AB |
293 | { |
294 | void *buf; | |
295 | int len, err, second_is_newer, bitflips = 0, corrupted = 0; | |
296 | uint32_t data_crc, crc; | |
8bc22961 | 297 | struct ubi_vid_hdr *vh = NULL; |
3261ebd7 | 298 | unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum); |
801c135c | 299 | |
9869cd80 | 300 | if (sqnum2 == seb->sqnum) { |
801c135c | 301 | /* |
9869cd80 AB |
302 | * This must be a really ancient UBI image which has been |
303 | * created before sequence numbers support has been added. At | |
304 | * that times we used 32-bit LEB versions stored in logical | |
305 | * eraseblocks. That was before UBI got into mainline. We do not | |
0525dac9 AB |
306 | * support these images anymore. Well, those images still work, |
307 | * but only if no unclean reboots happened. | |
801c135c | 308 | */ |
9869cd80 AB |
309 | ubi_err("unsupported on-flash UBI format\n"); |
310 | return -EINVAL; | |
311 | } | |
64203195 | 312 | |
9869cd80 AB |
313 | /* Obviously the LEB with lower sequence counter is older */ |
314 | second_is_newer = !!(sqnum2 > seb->sqnum); | |
801c135c AB |
315 | |
316 | /* | |
317 | * Now we know which copy is newer. If the copy flag of the PEB with | |
318 | * newer version is not set, then we just return, otherwise we have to | |
319 | * check data CRC. For the second PEB we already have the VID header, | |
320 | * for the first one - we'll need to re-read it from flash. | |
321 | * | |
9869cd80 | 322 | * Note: this may be optimized so that we wouldn't read twice. |
801c135c AB |
323 | */ |
324 | ||
325 | if (second_is_newer) { | |
326 | if (!vid_hdr->copy_flag) { | |
327 | /* It is not a copy, so it is newer */ | |
328 | dbg_bld("second PEB %d is newer, copy_flag is unset", | |
329 | pnum); | |
330 | return 1; | |
331 | } | |
332 | } else { | |
fb22b59b AB |
333 | if (!seb->copy_flag) { |
334 | /* It is not a copy, so it is newer */ | |
335 | dbg_bld("first PEB %d is newer, copy_flag is unset", | |
336 | pnum); | |
337 | return bitflips << 1; | |
338 | } | |
801c135c | 339 | |
33818bbb | 340 | vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); |
8bc22961 | 341 | if (!vh) |
801c135c AB |
342 | return -ENOMEM; |
343 | ||
fb22b59b | 344 | pnum = seb->pnum; |
8bc22961 | 345 | err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0); |
801c135c AB |
346 | if (err) { |
347 | if (err == UBI_IO_BITFLIPS) | |
348 | bitflips = 1; | |
349 | else { | |
350 | dbg_err("VID of PEB %d header is bad, but it " | |
0525dac9 | 351 | "was OK earlier, err %d", pnum, err); |
801c135c AB |
352 | if (err > 0) |
353 | err = -EIO; | |
354 | ||
355 | goto out_free_vidh; | |
356 | } | |
357 | } | |
358 | ||
8bc22961 | 359 | vid_hdr = vh; |
801c135c AB |
360 | } |
361 | ||
362 | /* Read the data of the copy and check the CRC */ | |
363 | ||
3261ebd7 | 364 | len = be32_to_cpu(vid_hdr->data_size); |
92ad8f37 | 365 | buf = vmalloc(len); |
801c135c AB |
366 | if (!buf) { |
367 | err = -ENOMEM; | |
368 | goto out_free_vidh; | |
369 | } | |
370 | ||
371 | err = ubi_io_read_data(ubi, buf, pnum, 0, len); | |
b77bcb07 | 372 | if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) |
801c135c AB |
373 | goto out_free_buf; |
374 | ||
3261ebd7 | 375 | data_crc = be32_to_cpu(vid_hdr->data_crc); |
801c135c AB |
376 | crc = crc32(UBI_CRC32_INIT, buf, len); |
377 | if (crc != data_crc) { | |
378 | dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x", | |
379 | pnum, crc, data_crc); | |
380 | corrupted = 1; | |
381 | bitflips = 0; | |
382 | second_is_newer = !second_is_newer; | |
383 | } else { | |
384 | dbg_bld("PEB %d CRC is OK", pnum); | |
385 | bitflips = !!err; | |
386 | } | |
387 | ||
92ad8f37 | 388 | vfree(buf); |
8bc22961 | 389 | ubi_free_vid_hdr(ubi, vh); |
801c135c AB |
390 | |
391 | if (second_is_newer) | |
392 | dbg_bld("second PEB %d is newer, copy_flag is set", pnum); | |
393 | else | |
394 | dbg_bld("first PEB %d is newer, copy_flag is set", pnum); | |
395 | ||
396 | return second_is_newer | (bitflips << 1) | (corrupted << 2); | |
397 | ||
398 | out_free_buf: | |
92ad8f37 | 399 | vfree(buf); |
801c135c | 400 | out_free_vidh: |
8bc22961 | 401 | ubi_free_vid_hdr(ubi, vh); |
801c135c AB |
402 | return err; |
403 | } | |
404 | ||
405 | /** | |
ebaaf1af | 406 | * ubi_scan_add_used - add physical eraseblock to the scanning information. |
801c135c AB |
407 | * @ubi: UBI device description object |
408 | * @si: scanning information | |
409 | * @pnum: the physical eraseblock number | |
410 | * @ec: erase counter | |
411 | * @vid_hdr: the volume identifier header | |
412 | * @bitflips: if bit-flips were detected when this physical eraseblock was read | |
413 | * | |
79b510c0 AB |
414 | * This function adds information about a used physical eraseblock to the |
415 | * 'used' tree of the corresponding volume. The function is rather complex | |
416 | * because it has to handle cases when this is not the first physical | |
417 | * eraseblock belonging to the same logical eraseblock, and the newer one has | |
418 | * to be picked, while the older one has to be dropped. This function returns | |
419 | * zero in case of success and a negative error code in case of failure. | |
801c135c | 420 | */ |
e88d6e10 | 421 | int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si, |
801c135c AB |
422 | int pnum, int ec, const struct ubi_vid_hdr *vid_hdr, |
423 | int bitflips) | |
424 | { | |
425 | int err, vol_id, lnum; | |
801c135c AB |
426 | unsigned long long sqnum; |
427 | struct ubi_scan_volume *sv; | |
428 | struct ubi_scan_leb *seb; | |
429 | struct rb_node **p, *parent = NULL; | |
430 | ||
3261ebd7 CH |
431 | vol_id = be32_to_cpu(vid_hdr->vol_id); |
432 | lnum = be32_to_cpu(vid_hdr->lnum); | |
433 | sqnum = be64_to_cpu(vid_hdr->sqnum); | |
801c135c | 434 | |
9869cd80 AB |
435 | dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d", |
436 | pnum, vol_id, lnum, ec, sqnum, bitflips); | |
801c135c AB |
437 | |
438 | sv = add_volume(si, vol_id, pnum, vid_hdr); | |
0e4a008a | 439 | if (IS_ERR(sv)) |
801c135c AB |
440 | return PTR_ERR(sv); |
441 | ||
76eafe47 BS |
442 | if (si->max_sqnum < sqnum) |
443 | si->max_sqnum = sqnum; | |
444 | ||
801c135c AB |
445 | /* |
446 | * Walk the RB-tree of logical eraseblocks of volume @vol_id to look | |
447 | * if this is the first instance of this logical eraseblock or not. | |
448 | */ | |
449 | p = &sv->root.rb_node; | |
450 | while (*p) { | |
451 | int cmp_res; | |
452 | ||
453 | parent = *p; | |
454 | seb = rb_entry(parent, struct ubi_scan_leb, u.rb); | |
455 | if (lnum != seb->lnum) { | |
456 | if (lnum < seb->lnum) | |
457 | p = &(*p)->rb_left; | |
458 | else | |
459 | p = &(*p)->rb_right; | |
460 | continue; | |
461 | } | |
462 | ||
463 | /* | |
464 | * There is already a physical eraseblock describing the same | |
465 | * logical eraseblock present. | |
466 | */ | |
467 | ||
468 | dbg_bld("this LEB already exists: PEB %d, sqnum %llu, " | |
9869cd80 | 469 | "EC %d", seb->pnum, seb->sqnum, seb->ec); |
801c135c AB |
470 | |
471 | /* | |
472 | * Make sure that the logical eraseblocks have different | |
473 | * sequence numbers. Otherwise the image is bad. | |
474 | * | |
9869cd80 AB |
475 | * However, if the sequence number is zero, we assume it must |
476 | * be an ancient UBI image from the era when UBI did not have | |
477 | * sequence numbers. We still can attach these images, unless | |
478 | * there is a need to distinguish between old and new | |
479 | * eraseblocks, in which case we'll refuse the image in | |
480 | * 'compare_lebs()'. In other words, we attach old clean | |
481 | * images, but refuse attaching old images with duplicated | |
482 | * logical eraseblocks because there was an unclean reboot. | |
801c135c AB |
483 | */ |
484 | if (seb->sqnum == sqnum && sqnum != 0) { | |
485 | ubi_err("two LEBs with same sequence number %llu", | |
486 | sqnum); | |
487 | ubi_dbg_dump_seb(seb, 0); | |
488 | ubi_dbg_dump_vid_hdr(vid_hdr); | |
489 | return -EINVAL; | |
490 | } | |
491 | ||
492 | /* | |
493 | * Now we have to drop the older one and preserve the newer | |
494 | * one. | |
495 | */ | |
496 | cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr); | |
497 | if (cmp_res < 0) | |
498 | return cmp_res; | |
499 | ||
500 | if (cmp_res & 1) { | |
501 | /* | |
3f502622 | 502 | * This logical eraseblock is newer than the one |
801c135c AB |
503 | * found earlier. |
504 | */ | |
505 | err = validate_vid_hdr(vid_hdr, sv, pnum); | |
506 | if (err) | |
507 | return err; | |
508 | ||
0525dac9 AB |
509 | err = add_to_list(si, seb->pnum, seb->ec, cmp_res & 4, |
510 | &si->erase); | |
801c135c AB |
511 | if (err) |
512 | return err; | |
513 | ||
514 | seb->ec = ec; | |
515 | seb->pnum = pnum; | |
516 | seb->scrub = ((cmp_res & 2) || bitflips); | |
fb22b59b | 517 | seb->copy_flag = vid_hdr->copy_flag; |
801c135c | 518 | seb->sqnum = sqnum; |
801c135c AB |
519 | |
520 | if (sv->highest_lnum == lnum) | |
521 | sv->last_data_size = | |
3261ebd7 | 522 | be32_to_cpu(vid_hdr->data_size); |
801c135c AB |
523 | |
524 | return 0; | |
525 | } else { | |
526 | /* | |
025dfdaf | 527 | * This logical eraseblock is older than the one found |
801c135c AB |
528 | * previously. |
529 | */ | |
0525dac9 AB |
530 | return add_to_list(si, pnum, ec, cmp_res & 4, |
531 | &si->erase); | |
801c135c AB |
532 | } |
533 | } | |
534 | ||
535 | /* | |
536 | * We've met this logical eraseblock for the first time, add it to the | |
537 | * scanning information. | |
538 | */ | |
539 | ||
540 | err = validate_vid_hdr(vid_hdr, sv, pnum); | |
541 | if (err) | |
542 | return err; | |
543 | ||
544 | seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL); | |
545 | if (!seb) | |
546 | return -ENOMEM; | |
547 | ||
548 | seb->ec = ec; | |
549 | seb->pnum = pnum; | |
550 | seb->lnum = lnum; | |
801c135c | 551 | seb->scrub = bitflips; |
fb22b59b AB |
552 | seb->copy_flag = vid_hdr->copy_flag; |
553 | seb->sqnum = sqnum; | |
801c135c AB |
554 | |
555 | if (sv->highest_lnum <= lnum) { | |
556 | sv->highest_lnum = lnum; | |
3261ebd7 | 557 | sv->last_data_size = be32_to_cpu(vid_hdr->data_size); |
801c135c AB |
558 | } |
559 | ||
801c135c AB |
560 | sv->leb_count += 1; |
561 | rb_link_node(&seb->u.rb, parent, p); | |
562 | rb_insert_color(&seb->u.rb, &sv->root); | |
563 | return 0; | |
564 | } | |
565 | ||
566 | /** | |
ebaaf1af | 567 | * ubi_scan_find_sv - find volume in the scanning information. |
801c135c AB |
568 | * @si: scanning information |
569 | * @vol_id: the requested volume ID | |
570 | * | |
571 | * This function returns a pointer to the volume description or %NULL if there | |
572 | * are no data about this volume in the scanning information. | |
573 | */ | |
574 | struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si, | |
575 | int vol_id) | |
576 | { | |
577 | struct ubi_scan_volume *sv; | |
578 | struct rb_node *p = si->volumes.rb_node; | |
579 | ||
580 | while (p) { | |
581 | sv = rb_entry(p, struct ubi_scan_volume, rb); | |
582 | ||
583 | if (vol_id == sv->vol_id) | |
584 | return sv; | |
585 | ||
586 | if (vol_id > sv->vol_id) | |
587 | p = p->rb_left; | |
588 | else | |
589 | p = p->rb_right; | |
590 | } | |
591 | ||
592 | return NULL; | |
593 | } | |
594 | ||
595 | /** | |
ebaaf1af | 596 | * ubi_scan_find_seb - find LEB in the volume scanning information. |
801c135c AB |
597 | * @sv: a pointer to the volume scanning information |
598 | * @lnum: the requested logical eraseblock | |
599 | * | |
600 | * This function returns a pointer to the scanning logical eraseblock or %NULL | |
601 | * if there are no data about it in the scanning volume information. | |
602 | */ | |
603 | struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv, | |
604 | int lnum) | |
605 | { | |
606 | struct ubi_scan_leb *seb; | |
607 | struct rb_node *p = sv->root.rb_node; | |
608 | ||
609 | while (p) { | |
610 | seb = rb_entry(p, struct ubi_scan_leb, u.rb); | |
611 | ||
612 | if (lnum == seb->lnum) | |
613 | return seb; | |
614 | ||
615 | if (lnum > seb->lnum) | |
616 | p = p->rb_left; | |
617 | else | |
618 | p = p->rb_right; | |
619 | } | |
620 | ||
621 | return NULL; | |
622 | } | |
623 | ||
624 | /** | |
625 | * ubi_scan_rm_volume - delete scanning information about a volume. | |
626 | * @si: scanning information | |
627 | * @sv: the volume scanning information to delete | |
628 | */ | |
629 | void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv) | |
630 | { | |
631 | struct rb_node *rb; | |
632 | struct ubi_scan_leb *seb; | |
633 | ||
634 | dbg_bld("remove scanning information about volume %d", sv->vol_id); | |
635 | ||
636 | while ((rb = rb_first(&sv->root))) { | |
637 | seb = rb_entry(rb, struct ubi_scan_leb, u.rb); | |
638 | rb_erase(&seb->u.rb, &sv->root); | |
639 | list_add_tail(&seb->u.list, &si->erase); | |
640 | } | |
641 | ||
642 | rb_erase(&sv->rb, &si->volumes); | |
643 | kfree(sv); | |
644 | si->vols_found -= 1; | |
645 | } | |
646 | ||
647 | /** | |
648 | * ubi_scan_erase_peb - erase a physical eraseblock. | |
649 | * @ubi: UBI device description object | |
650 | * @si: scanning information | |
651 | * @pnum: physical eraseblock number to erase; | |
652 | * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown) | |
653 | * | |
654 | * This function erases physical eraseblock 'pnum', and writes the erase | |
655 | * counter header to it. This function should only be used on UBI device | |
85c6e6e2 AB |
656 | * initialization stages, when the EBA sub-system had not been yet initialized. |
657 | * This function returns zero in case of success and a negative error code in | |
658 | * case of failure. | |
801c135c | 659 | */ |
e88d6e10 AB |
660 | int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si, |
661 | int pnum, int ec) | |
801c135c AB |
662 | { |
663 | int err; | |
664 | struct ubi_ec_hdr *ec_hdr; | |
665 | ||
801c135c AB |
666 | if ((long long)ec >= UBI_MAX_ERASECOUNTER) { |
667 | /* | |
668 | * Erase counter overflow. Upgrade UBI and use 64-bit | |
669 | * erase counters internally. | |
670 | */ | |
671 | ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec); | |
672 | return -EINVAL; | |
673 | } | |
674 | ||
dcec4c3b FM |
675 | ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); |
676 | if (!ec_hdr) | |
677 | return -ENOMEM; | |
678 | ||
3261ebd7 | 679 | ec_hdr->ec = cpu_to_be64(ec); |
801c135c AB |
680 | |
681 | err = ubi_io_sync_erase(ubi, pnum, 0); | |
682 | if (err < 0) | |
683 | goto out_free; | |
684 | ||
685 | err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr); | |
686 | ||
687 | out_free: | |
688 | kfree(ec_hdr); | |
689 | return err; | |
690 | } | |
691 | ||
692 | /** | |
693 | * ubi_scan_get_free_peb - get a free physical eraseblock. | |
694 | * @ubi: UBI device description object | |
695 | * @si: scanning information | |
696 | * | |
697 | * This function returns a free physical eraseblock. It is supposed to be | |
85c6e6e2 AB |
698 | * called on the UBI initialization stages when the wear-leveling sub-system is |
699 | * not initialized yet. This function picks a physical eraseblocks from one of | |
700 | * the lists, writes the EC header if it is needed, and removes it from the | |
701 | * list. | |
801c135c AB |
702 | * |
703 | * This function returns scanning physical eraseblock information in case of | |
704 | * success and an error code in case of failure. | |
705 | */ | |
e88d6e10 | 706 | struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi, |
801c135c AB |
707 | struct ubi_scan_info *si) |
708 | { | |
5fc01ab6 AB |
709 | int err = 0; |
710 | struct ubi_scan_leb *seb, *tmp_seb; | |
801c135c AB |
711 | |
712 | if (!list_empty(&si->free)) { | |
713 | seb = list_entry(si->free.next, struct ubi_scan_leb, u.list); | |
714 | list_del(&seb->u.list); | |
715 | dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec); | |
716 | return seb; | |
717 | } | |
718 | ||
5fc01ab6 AB |
719 | /* |
720 | * We try to erase the first physical eraseblock from the erase list | |
721 | * and pick it if we succeed, or try to erase the next one if not. And | |
722 | * so forth. We don't want to take care about bad eraseblocks here - | |
723 | * they'll be handled later. | |
724 | */ | |
725 | list_for_each_entry_safe(seb, tmp_seb, &si->erase, u.list) { | |
726 | if (seb->ec == UBI_SCAN_UNKNOWN_EC) | |
727 | seb->ec = si->mean_ec; | |
801c135c | 728 | |
5fc01ab6 AB |
729 | err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1); |
730 | if (err) | |
731 | continue; | |
801c135c | 732 | |
5fc01ab6 AB |
733 | seb->ec += 1; |
734 | list_del(&seb->u.list); | |
735 | dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec); | |
736 | return seb; | |
801c135c AB |
737 | } |
738 | ||
5fc01ab6 | 739 | ubi_err("no free eraseblocks"); |
801c135c AB |
740 | return ERR_PTR(-ENOSPC); |
741 | } | |
742 | ||
feeba4b8 AB |
743 | /** |
744 | * check_data_ff - make sure PEB contains only 0xFF data. | |
745 | * @ubi: UBI device description object | |
746 | * @vid_hrd: the (corrupted) VID header of this PEB | |
747 | * @pnum: the physical eraseblock number to check | |
748 | * | |
749 | * This is a helper function which is used to distinguish between VID header | |
750 | * corruptions caused by power cuts and other reasons. If the PEB contains only | |
751 | * 0xFF bytes at the data area, the VID header is most probably corrupted | |
752 | * because of a power cut (%0 is returned in this case). Otherwise, it was | |
753 | * corrupted for some other reasons (%1 is returned in this case). A negative | |
754 | * error code is returned if a read error occurred. | |
755 | * | |
756 | * If the corruption reason was a power cut, UBI can safely erase this PEB. | |
757 | * Otherwise, it should preserve it to avoid possibly destroying important | |
758 | * information. | |
759 | */ | |
760 | static int check_data_ff(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr, | |
761 | int pnum) | |
762 | { | |
763 | int err; | |
764 | ||
765 | mutex_lock(&ubi->buf_mutex); | |
766 | memset(ubi->peb_buf1, 0x00, ubi->leb_size); | |
767 | ||
768 | err = ubi_io_read(ubi, ubi->peb_buf1, pnum, ubi->leb_start, | |
769 | ubi->leb_size); | |
770 | if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG) | |
771 | return err; | |
772 | ||
773 | if (ubi_check_pattern(ubi->peb_buf1, 0xFF, ubi->leb_size)) { | |
774 | mutex_unlock(&ubi->buf_mutex); | |
775 | return 0; | |
776 | } | |
777 | ||
778 | ubi_err("PEB %d contains corrupted VID header, and the data does not " | |
779 | "contain all 0xFF, this may be a non-UBI PEB or a severe VID " | |
780 | "header corruption which requires manual inspection", pnum); | |
781 | ubi_dbg_dump_vid_hdr(vid_hdr); | |
782 | dbg_msg("hexdump of PEB %d offset %d, length %d", | |
783 | pnum, ubi->leb_start, ubi->leb_size); | |
784 | ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, | |
785 | ubi->peb_buf1, ubi->leb_size, 1); | |
786 | mutex_unlock(&ubi->buf_mutex); | |
787 | return -EINVAL; | |
788 | } | |
789 | ||
801c135c | 790 | /** |
ebaaf1af | 791 | * process_eb - read, check UBI headers, and add them to scanning information. |
801c135c AB |
792 | * @ubi: UBI device description object |
793 | * @si: scanning information | |
794 | * @pnum: the physical eraseblock number | |
795 | * | |
78d87c95 | 796 | * This function returns a zero if the physical eraseblock was successfully |
801c135c AB |
797 | * handled and a negative error code in case of failure. |
798 | */ | |
9c9ec147 AB |
799 | static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, |
800 | int pnum) | |
801c135c | 801 | { |
c18a8418 | 802 | long long uninitialized_var(ec); |
e0e718c2 | 803 | int err, bitflips = 0, vol_id, ec_err = 0; |
801c135c AB |
804 | |
805 | dbg_bld("scan PEB %d", pnum); | |
806 | ||
807 | /* Skip bad physical eraseblocks */ | |
808 | err = ubi_io_is_bad(ubi, pnum); | |
809 | if (err < 0) | |
810 | return err; | |
811 | else if (err) { | |
812 | /* | |
85c6e6e2 AB |
813 | * FIXME: this is actually duty of the I/O sub-system to |
814 | * initialize this, but MTD does not provide enough | |
815 | * information. | |
801c135c AB |
816 | */ |
817 | si->bad_peb_count += 1; | |
818 | return 0; | |
819 | } | |
820 | ||
821 | err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0); | |
822 | if (err < 0) | |
823 | return err; | |
b3321508 AB |
824 | switch (err) { |
825 | case 0: | |
826 | break; | |
827 | case UBI_IO_BITFLIPS: | |
801c135c | 828 | bitflips = 1; |
b3321508 AB |
829 | break; |
830 | case UBI_IO_FF: | |
0525dac9 AB |
831 | si->empty_peb_count += 1; |
832 | return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, 0, | |
833 | &si->erase); | |
b3321508 | 834 | case UBI_IO_FF_BITFLIPS: |
0525dac9 AB |
835 | si->empty_peb_count += 1; |
836 | return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, 1, | |
837 | &si->erase); | |
b3321508 | 838 | case UBI_IO_BAD_HDR_EBADMSG: |
b3321508 | 839 | case UBI_IO_BAD_HDR: |
801c135c AB |
840 | /* |
841 | * We have to also look at the VID header, possibly it is not | |
842 | * corrupted. Set %bitflips flag in order to make this PEB be | |
843 | * moved and EC be re-created. | |
844 | */ | |
e0e718c2 | 845 | ec_err = err; |
801c135c AB |
846 | ec = UBI_SCAN_UNKNOWN_EC; |
847 | bitflips = 1; | |
b3321508 AB |
848 | break; |
849 | default: | |
850 | ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err); | |
851 | return -EINVAL; | |
801c135c AB |
852 | } |
853 | ||
e0e718c2 | 854 | if (!ec_err) { |
fe96efc1 AB |
855 | int image_seq; |
856 | ||
801c135c AB |
857 | /* Make sure UBI version is OK */ |
858 | if (ech->version != UBI_VERSION) { | |
859 | ubi_err("this UBI version is %d, image version is %d", | |
860 | UBI_VERSION, (int)ech->version); | |
861 | return -EINVAL; | |
862 | } | |
863 | ||
3261ebd7 | 864 | ec = be64_to_cpu(ech->ec); |
801c135c AB |
865 | if (ec > UBI_MAX_ERASECOUNTER) { |
866 | /* | |
867 | * Erase counter overflow. The EC headers have 64 bits | |
868 | * reserved, but we anyway make use of only 31 bit | |
869 | * values, as this seems to be enough for any existing | |
870 | * flash. Upgrade UBI and use 64-bit erase counters | |
871 | * internally. | |
872 | */ | |
873 | ubi_err("erase counter overflow, max is %d", | |
874 | UBI_MAX_ERASECOUNTER); | |
875 | ubi_dbg_dump_ec_hdr(ech); | |
876 | return -EINVAL; | |
877 | } | |
fe96efc1 | 878 | |
32bc4820 AH |
879 | /* |
880 | * Make sure that all PEBs have the same image sequence number. | |
881 | * This allows us to detect situations when users flash UBI | |
882 | * images incorrectly, so that the flash has the new UBI image | |
883 | * and leftovers from the old one. This feature was added | |
884 | * relatively recently, and the sequence number was always | |
885 | * zero, because old UBI implementations always set it to zero. | |
886 | * For this reasons, we do not panic if some PEBs have zero | |
887 | * sequence number, while other PEBs have non-zero sequence | |
888 | * number. | |
889 | */ | |
3dc948da | 890 | image_seq = be32_to_cpu(ech->image_seq); |
2eadaad6 | 891 | if (!ubi->image_seq && image_seq) |
fe96efc1 | 892 | ubi->image_seq = image_seq; |
2eadaad6 AB |
893 | if (ubi->image_seq && image_seq && |
894 | ubi->image_seq != image_seq) { | |
fe96efc1 AB |
895 | ubi_err("bad image sequence number %d in PEB %d, " |
896 | "expected %d", image_seq, pnum, ubi->image_seq); | |
897 | ubi_dbg_dump_ec_hdr(ech); | |
898 | return -EINVAL; | |
899 | } | |
801c135c AB |
900 | } |
901 | ||
902 | /* OK, we've done with the EC header, let's look at the VID header */ | |
903 | ||
904 | err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0); | |
905 | if (err < 0) | |
906 | return err; | |
b3321508 AB |
907 | switch (err) { |
908 | case 0: | |
909 | break; | |
910 | case UBI_IO_BITFLIPS: | |
801c135c | 911 | bitflips = 1; |
b3321508 AB |
912 | break; |
913 | case UBI_IO_BAD_HDR_EBADMSG: | |
0525dac9 AB |
914 | if (ec_err == UBI_IO_BAD_HDR_EBADMSG) |
915 | /* | |
916 | * Both EC and VID headers are corrupted and were read | |
917 | * with data integrity error, probably this is a bad | |
918 | * PEB, bit it is not marked as bad yet. This may also | |
919 | * be a result of power cut during erasure. | |
920 | */ | |
921 | si->maybe_bad_peb_count += 1; | |
b3321508 | 922 | case UBI_IO_BAD_HDR: |
feeba4b8 AB |
923 | if (ec_err) |
924 | /* | |
925 | * Both headers are corrupted. There is a possibility | |
926 | * that this a valid UBI PEB which has corresponding | |
927 | * LEB, but the headers are corrupted. However, it is | |
928 | * impossible to distinguish it from a PEB which just | |
929 | * contains garbage because a power cut during erase | |
930 | * operation. So we just schedule this PEB for erasure. | |
931 | */ | |
932 | err = 0; | |
933 | else | |
934 | /* | |
935 | * The EC was OK, but the VID header is corrupted. We | |
936 | * have to check what is in the data area. | |
937 | */ | |
938 | err = check_data_ff(ubi, vidh, pnum); | |
939 | if (!err) | |
940 | /* This corruption is caused by a power cut */ | |
941 | err = add_to_list(si, pnum, ec, 1, &si->erase); | |
942 | else | |
943 | /* This is an unexpected corruption */ | |
944 | err = add_corrupted(si, pnum, ec); | |
945 | if (err) | |
946 | return err; | |
947 | goto adjust_mean_ec; | |
b3321508 | 948 | case UBI_IO_FF_BITFLIPS: |
0525dac9 | 949 | err = add_to_list(si, pnum, ec, 1, &si->erase); |
801c135c AB |
950 | if (err) |
951 | return err; | |
952 | goto adjust_mean_ec; | |
b3321508 AB |
953 | case UBI_IO_FF: |
954 | if (ec_err) | |
0525dac9 | 955 | err = add_to_list(si, pnum, ec, 1, &si->erase); |
b3321508 | 956 | else |
0525dac9 | 957 | err = add_to_list(si, pnum, ec, 0, &si->free); |
801c135c AB |
958 | if (err) |
959 | return err; | |
960 | goto adjust_mean_ec; | |
b3321508 AB |
961 | default: |
962 | ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d", | |
963 | err); | |
964 | return -EINVAL; | |
801c135c AB |
965 | } |
966 | ||
3261ebd7 | 967 | vol_id = be32_to_cpu(vidh->vol_id); |
91f2d53c | 968 | if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) { |
3261ebd7 | 969 | int lnum = be32_to_cpu(vidh->lnum); |
801c135c AB |
970 | |
971 | /* Unsupported internal volume */ | |
972 | switch (vidh->compat) { | |
973 | case UBI_COMPAT_DELETE: | |
974 | ubi_msg("\"delete\" compatible internal volume %d:%d" | |
158132c9 | 975 | " found, will remove it", vol_id, lnum); |
0525dac9 | 976 | err = add_to_list(si, pnum, ec, 1, &si->erase); |
801c135c AB |
977 | if (err) |
978 | return err; | |
158132c9 | 979 | return 0; |
801c135c AB |
980 | |
981 | case UBI_COMPAT_RO: | |
982 | ubi_msg("read-only compatible internal volume %d:%d" | |
983 | " found, switch to read-only mode", | |
984 | vol_id, lnum); | |
985 | ubi->ro_mode = 1; | |
986 | break; | |
987 | ||
988 | case UBI_COMPAT_PRESERVE: | |
989 | ubi_msg("\"preserve\" compatible internal volume %d:%d" | |
990 | " found", vol_id, lnum); | |
0525dac9 | 991 | err = add_to_list(si, pnum, ec, 0, &si->alien); |
801c135c AB |
992 | if (err) |
993 | return err; | |
801c135c AB |
994 | return 0; |
995 | ||
996 | case UBI_COMPAT_REJECT: | |
997 | ubi_err("incompatible internal volume %d:%d found", | |
998 | vol_id, lnum); | |
999 | return -EINVAL; | |
1000 | } | |
1001 | } | |
1002 | ||
e0e718c2 | 1003 | if (ec_err) |
29a88c99 AB |
1004 | ubi_warn("valid VID header but corrupted EC header at PEB %d", |
1005 | pnum); | |
801c135c AB |
1006 | err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips); |
1007 | if (err) | |
1008 | return err; | |
1009 | ||
1010 | adjust_mean_ec: | |
e0e718c2 | 1011 | if (!ec_err) { |
4bc1dca4 AB |
1012 | si->ec_sum += ec; |
1013 | si->ec_count += 1; | |
801c135c AB |
1014 | if (ec > si->max_ec) |
1015 | si->max_ec = ec; | |
1016 | if (ec < si->min_ec) | |
1017 | si->min_ec = ec; | |
1018 | } | |
1019 | ||
1020 | return 0; | |
1021 | } | |
1022 | ||
0798cea8 AB |
1023 | /** |
1024 | * check_what_we_have - check what PEB were found by scanning. | |
1025 | * @ubi: UBI device description object | |
1026 | * @si: scanning information | |
1027 | * | |
1028 | * This is a helper function which takes a look what PEBs were found by | |
1029 | * scanning, and decides whether the flash is empty and should be formatted and | |
1030 | * whether there are too many corrupted PEBs and we should not attach this | |
1031 | * MTD device. Returns zero if we should proceed with attaching the MTD device, | |
1032 | * and %-EINVAL if we should not. | |
1033 | */ | |
f5d5b1f8 | 1034 | static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si) |
0798cea8 AB |
1035 | { |
1036 | struct ubi_scan_leb *seb; | |
0525dac9 | 1037 | int max_corr, peb_count; |
0798cea8 | 1038 | |
0525dac9 AB |
1039 | peb_count = ubi->peb_count - si->bad_peb_count - si->alien_peb_count; |
1040 | max_corr = peb_count / 20 ?: 8; | |
0798cea8 AB |
1041 | |
1042 | /* | |
0525dac9 | 1043 | * Few corrupted PEBs is not a problem and may be just a result of |
0798cea8 AB |
1044 | * unclean reboots. However, many of them may indicate some problems |
1045 | * with the flash HW or driver. | |
1046 | */ | |
0525dac9 AB |
1047 | if (si->corr_peb_count) { |
1048 | ubi_err("%d PEBs are corrupted and preserved", | |
1049 | si->corr_peb_count); | |
1050 | printk(KERN_ERR "Corrupted PEBs are:"); | |
0798cea8 AB |
1051 | list_for_each_entry(seb, &si->corr, u.list) |
1052 | printk(KERN_CONT " %d", seb->pnum); | |
1053 | printk(KERN_CONT "\n"); | |
1054 | ||
1055 | /* | |
1056 | * If too many PEBs are corrupted, we refuse attaching, | |
1057 | * otherwise, only print a warning. | |
1058 | */ | |
1059 | if (si->corr_peb_count >= max_corr) { | |
1060 | ubi_err("too many corrupted PEBs, refusing this device"); | |
1061 | return -EINVAL; | |
1062 | } | |
1063 | } | |
1064 | ||
0525dac9 AB |
1065 | if (si->empty_peb_count + si->maybe_bad_peb_count == peb_count) { |
1066 | /* | |
1067 | * All PEBs are empty, or almost all - a couple PEBs look like | |
1068 | * they may be bad PEBs which were not marked as bad yet. | |
1069 | * | |
1070 | * This piece of code basically tries to distinguish between | |
1071 | * the following situations: | |
1072 | * | |
1073 | * 1. Flash is empty, but there are few bad PEBs, which are not | |
1074 | * marked as bad so far, and which were read with error. We | |
1075 | * want to go ahead and format this flash. While formatting, | |
1076 | * the faulty PEBs will probably be marked as bad. | |
1077 | * | |
1078 | * 2. Flash contains non-UBI data and we do not want to format | |
1079 | * it and destroy possibly important information. | |
1080 | */ | |
1081 | if (si->maybe_bad_peb_count <= 2) { | |
0798cea8 AB |
1082 | si->is_empty = 1; |
1083 | ubi_msg("empty MTD device detected"); | |
0525dac9 AB |
1084 | get_random_bytes(&ubi->image_seq, |
1085 | sizeof(ubi->image_seq)); | |
0798cea8 | 1086 | } else { |
0525dac9 AB |
1087 | ubi_err("MTD device is not UBI-formatted and possibly " |
1088 | "contains non-UBI data - refusing it"); | |
0798cea8 AB |
1089 | return -EINVAL; |
1090 | } | |
0525dac9 | 1091 | |
0798cea8 AB |
1092 | } |
1093 | ||
0798cea8 AB |
1094 | return 0; |
1095 | } | |
1096 | ||
801c135c AB |
1097 | /** |
1098 | * ubi_scan - scan an MTD device. | |
1099 | * @ubi: UBI device description object | |
1100 | * | |
1101 | * This function does full scanning of an MTD device and returns complete | |
1102 | * information about it. In case of failure, an error code is returned. | |
1103 | */ | |
1104 | struct ubi_scan_info *ubi_scan(struct ubi_device *ubi) | |
1105 | { | |
1106 | int err, pnum; | |
1107 | struct rb_node *rb1, *rb2; | |
1108 | struct ubi_scan_volume *sv; | |
1109 | struct ubi_scan_leb *seb; | |
1110 | struct ubi_scan_info *si; | |
1111 | ||
1112 | si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL); | |
1113 | if (!si) | |
1114 | return ERR_PTR(-ENOMEM); | |
1115 | ||
1116 | INIT_LIST_HEAD(&si->corr); | |
1117 | INIT_LIST_HEAD(&si->free); | |
1118 | INIT_LIST_HEAD(&si->erase); | |
1119 | INIT_LIST_HEAD(&si->alien); | |
1120 | si->volumes = RB_ROOT; | |
801c135c AB |
1121 | |
1122 | err = -ENOMEM; | |
1123 | ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL); | |
1124 | if (!ech) | |
1125 | goto out_si; | |
1126 | ||
33818bbb | 1127 | vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL); |
801c135c AB |
1128 | if (!vidh) |
1129 | goto out_ech; | |
1130 | ||
1131 | for (pnum = 0; pnum < ubi->peb_count; pnum++) { | |
1132 | cond_resched(); | |
1133 | ||
c8566350 | 1134 | dbg_gen("process PEB %d", pnum); |
801c135c AB |
1135 | err = process_eb(ubi, si, pnum); |
1136 | if (err < 0) | |
1137 | goto out_vidh; | |
1138 | } | |
1139 | ||
1140 | dbg_msg("scanning is finished"); | |
1141 | ||
4bc1dca4 | 1142 | /* Calculate mean erase counter */ |
3013ee31 AB |
1143 | if (si->ec_count) |
1144 | si->mean_ec = div_u64(si->ec_sum, si->ec_count); | |
801c135c | 1145 | |
0798cea8 AB |
1146 | err = check_what_we_have(ubi, si); |
1147 | if (err) | |
1148 | goto out_vidh; | |
4a406856 | 1149 | |
801c135c AB |
1150 | /* |
1151 | * In case of unknown erase counter we use the mean erase counter | |
1152 | * value. | |
1153 | */ | |
1154 | ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { | |
1155 | ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) | |
1156 | if (seb->ec == UBI_SCAN_UNKNOWN_EC) | |
1157 | seb->ec = si->mean_ec; | |
1158 | } | |
1159 | ||
1160 | list_for_each_entry(seb, &si->free, u.list) { | |
1161 | if (seb->ec == UBI_SCAN_UNKNOWN_EC) | |
1162 | seb->ec = si->mean_ec; | |
1163 | } | |
1164 | ||
1165 | list_for_each_entry(seb, &si->corr, u.list) | |
1166 | if (seb->ec == UBI_SCAN_UNKNOWN_EC) | |
1167 | seb->ec = si->mean_ec; | |
1168 | ||
1169 | list_for_each_entry(seb, &si->erase, u.list) | |
1170 | if (seb->ec == UBI_SCAN_UNKNOWN_EC) | |
1171 | seb->ec = si->mean_ec; | |
1172 | ||
1173 | err = paranoid_check_si(ubi, si); | |
adbf05e3 | 1174 | if (err) |
801c135c | 1175 | goto out_vidh; |
801c135c AB |
1176 | |
1177 | ubi_free_vid_hdr(ubi, vidh); | |
1178 | kfree(ech); | |
1179 | ||
1180 | return si; | |
1181 | ||
1182 | out_vidh: | |
1183 | ubi_free_vid_hdr(ubi, vidh); | |
1184 | out_ech: | |
1185 | kfree(ech); | |
1186 | out_si: | |
1187 | ubi_scan_destroy_si(si); | |
1188 | return ERR_PTR(err); | |
1189 | } | |
1190 | ||
1191 | /** | |
1192 | * destroy_sv - free the scanning volume information | |
1193 | * @sv: scanning volume information | |
1194 | * | |
1195 | * This function destroys the volume RB-tree (@sv->root) and the scanning | |
1196 | * volume information. | |
1197 | */ | |
1198 | static void destroy_sv(struct ubi_scan_volume *sv) | |
1199 | { | |
1200 | struct ubi_scan_leb *seb; | |
1201 | struct rb_node *this = sv->root.rb_node; | |
1202 | ||
1203 | while (this) { | |
1204 | if (this->rb_left) | |
1205 | this = this->rb_left; | |
1206 | else if (this->rb_right) | |
1207 | this = this->rb_right; | |
1208 | else { | |
1209 | seb = rb_entry(this, struct ubi_scan_leb, u.rb); | |
1210 | this = rb_parent(this); | |
1211 | if (this) { | |
1212 | if (this->rb_left == &seb->u.rb) | |
1213 | this->rb_left = NULL; | |
1214 | else | |
1215 | this->rb_right = NULL; | |
1216 | } | |
1217 | ||
1218 | kfree(seb); | |
1219 | } | |
1220 | } | |
1221 | kfree(sv); | |
1222 | } | |
1223 | ||
1224 | /** | |
1225 | * ubi_scan_destroy_si - destroy scanning information. | |
1226 | * @si: scanning information | |
1227 | */ | |
1228 | void ubi_scan_destroy_si(struct ubi_scan_info *si) | |
1229 | { | |
1230 | struct ubi_scan_leb *seb, *seb_tmp; | |
1231 | struct ubi_scan_volume *sv; | |
1232 | struct rb_node *rb; | |
1233 | ||
1234 | list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) { | |
1235 | list_del(&seb->u.list); | |
1236 | kfree(seb); | |
1237 | } | |
1238 | list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) { | |
1239 | list_del(&seb->u.list); | |
1240 | kfree(seb); | |
1241 | } | |
1242 | list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) { | |
1243 | list_del(&seb->u.list); | |
1244 | kfree(seb); | |
1245 | } | |
1246 | list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) { | |
1247 | list_del(&seb->u.list); | |
1248 | kfree(seb); | |
1249 | } | |
1250 | ||
1251 | /* Destroy the volume RB-tree */ | |
1252 | rb = si->volumes.rb_node; | |
1253 | while (rb) { | |
1254 | if (rb->rb_left) | |
1255 | rb = rb->rb_left; | |
1256 | else if (rb->rb_right) | |
1257 | rb = rb->rb_right; | |
1258 | else { | |
1259 | sv = rb_entry(rb, struct ubi_scan_volume, rb); | |
1260 | ||
1261 | rb = rb_parent(rb); | |
1262 | if (rb) { | |
1263 | if (rb->rb_left == &sv->rb) | |
1264 | rb->rb_left = NULL; | |
1265 | else | |
1266 | rb->rb_right = NULL; | |
1267 | } | |
1268 | ||
1269 | destroy_sv(sv); | |
1270 | } | |
1271 | } | |
1272 | ||
1273 | kfree(si); | |
1274 | } | |
1275 | ||
1276 | #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID | |
1277 | ||
1278 | /** | |
ebaaf1af | 1279 | * paranoid_check_si - check the scanning information. |
801c135c AB |
1280 | * @ubi: UBI device description object |
1281 | * @si: scanning information | |
1282 | * | |
adbf05e3 AB |
1283 | * This function returns zero if the scanning information is all right, and a |
1284 | * negative error code if not or if an error occurred. | |
801c135c | 1285 | */ |
e88d6e10 | 1286 | static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si) |
801c135c AB |
1287 | { |
1288 | int pnum, err, vols_found = 0; | |
1289 | struct rb_node *rb1, *rb2; | |
1290 | struct ubi_scan_volume *sv; | |
1291 | struct ubi_scan_leb *seb, *last_seb; | |
1292 | uint8_t *buf; | |
1293 | ||
1294 | /* | |
78d87c95 | 1295 | * At first, check that scanning information is OK. |
801c135c AB |
1296 | */ |
1297 | ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { | |
1298 | int leb_count = 0; | |
1299 | ||
1300 | cond_resched(); | |
1301 | ||
1302 | vols_found += 1; | |
1303 | ||
1304 | if (si->is_empty) { | |
1305 | ubi_err("bad is_empty flag"); | |
1306 | goto bad_sv; | |
1307 | } | |
1308 | ||
1309 | if (sv->vol_id < 0 || sv->highest_lnum < 0 || | |
1310 | sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 || | |
1311 | sv->data_pad < 0 || sv->last_data_size < 0) { | |
1312 | ubi_err("negative values"); | |
1313 | goto bad_sv; | |
1314 | } | |
1315 | ||
1316 | if (sv->vol_id >= UBI_MAX_VOLUMES && | |
1317 | sv->vol_id < UBI_INTERNAL_VOL_START) { | |
1318 | ubi_err("bad vol_id"); | |
1319 | goto bad_sv; | |
1320 | } | |
1321 | ||
1322 | if (sv->vol_id > si->highest_vol_id) { | |
1323 | ubi_err("highest_vol_id is %d, but vol_id %d is there", | |
1324 | si->highest_vol_id, sv->vol_id); | |
1325 | goto out; | |
1326 | } | |
1327 | ||
1328 | if (sv->vol_type != UBI_DYNAMIC_VOLUME && | |
1329 | sv->vol_type != UBI_STATIC_VOLUME) { | |
1330 | ubi_err("bad vol_type"); | |
1331 | goto bad_sv; | |
1332 | } | |
1333 | ||
1334 | if (sv->data_pad > ubi->leb_size / 2) { | |
1335 | ubi_err("bad data_pad"); | |
1336 | goto bad_sv; | |
1337 | } | |
1338 | ||
1339 | last_seb = NULL; | |
1340 | ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { | |
1341 | cond_resched(); | |
1342 | ||
1343 | last_seb = seb; | |
1344 | leb_count += 1; | |
1345 | ||
1346 | if (seb->pnum < 0 || seb->ec < 0) { | |
1347 | ubi_err("negative values"); | |
1348 | goto bad_seb; | |
1349 | } | |
1350 | ||
1351 | if (seb->ec < si->min_ec) { | |
1352 | ubi_err("bad si->min_ec (%d), %d found", | |
1353 | si->min_ec, seb->ec); | |
1354 | goto bad_seb; | |
1355 | } | |
1356 | ||
1357 | if (seb->ec > si->max_ec) { | |
1358 | ubi_err("bad si->max_ec (%d), %d found", | |
1359 | si->max_ec, seb->ec); | |
1360 | goto bad_seb; | |
1361 | } | |
1362 | ||
1363 | if (seb->pnum >= ubi->peb_count) { | |
1364 | ubi_err("too high PEB number %d, total PEBs %d", | |
1365 | seb->pnum, ubi->peb_count); | |
1366 | goto bad_seb; | |
1367 | } | |
1368 | ||
1369 | if (sv->vol_type == UBI_STATIC_VOLUME) { | |
1370 | if (seb->lnum >= sv->used_ebs) { | |
1371 | ubi_err("bad lnum or used_ebs"); | |
1372 | goto bad_seb; | |
1373 | } | |
1374 | } else { | |
1375 | if (sv->used_ebs != 0) { | |
1376 | ubi_err("non-zero used_ebs"); | |
1377 | goto bad_seb; | |
1378 | } | |
1379 | } | |
1380 | ||
1381 | if (seb->lnum > sv->highest_lnum) { | |
1382 | ubi_err("incorrect highest_lnum or lnum"); | |
1383 | goto bad_seb; | |
1384 | } | |
1385 | } | |
1386 | ||
1387 | if (sv->leb_count != leb_count) { | |
1388 | ubi_err("bad leb_count, %d objects in the tree", | |
1389 | leb_count); | |
1390 | goto bad_sv; | |
1391 | } | |
1392 | ||
1393 | if (!last_seb) | |
1394 | continue; | |
1395 | ||
1396 | seb = last_seb; | |
1397 | ||
1398 | if (seb->lnum != sv->highest_lnum) { | |
1399 | ubi_err("bad highest_lnum"); | |
1400 | goto bad_seb; | |
1401 | } | |
1402 | } | |
1403 | ||
1404 | if (vols_found != si->vols_found) { | |
1405 | ubi_err("bad si->vols_found %d, should be %d", | |
1406 | si->vols_found, vols_found); | |
1407 | goto out; | |
1408 | } | |
1409 | ||
1410 | /* Check that scanning information is correct */ | |
1411 | ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) { | |
1412 | last_seb = NULL; | |
1413 | ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) { | |
1414 | int vol_type; | |
1415 | ||
1416 | cond_resched(); | |
1417 | ||
1418 | last_seb = seb; | |
1419 | ||
1420 | err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1); | |
1421 | if (err && err != UBI_IO_BITFLIPS) { | |
1422 | ubi_err("VID header is not OK (%d)", err); | |
1423 | if (err > 0) | |
1424 | err = -EIO; | |
1425 | return err; | |
1426 | } | |
1427 | ||
1428 | vol_type = vidh->vol_type == UBI_VID_DYNAMIC ? | |
1429 | UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME; | |
1430 | if (sv->vol_type != vol_type) { | |
1431 | ubi_err("bad vol_type"); | |
1432 | goto bad_vid_hdr; | |
1433 | } | |
1434 | ||
3261ebd7 | 1435 | if (seb->sqnum != be64_to_cpu(vidh->sqnum)) { |
801c135c AB |
1436 | ubi_err("bad sqnum %llu", seb->sqnum); |
1437 | goto bad_vid_hdr; | |
1438 | } | |
1439 | ||
3261ebd7 | 1440 | if (sv->vol_id != be32_to_cpu(vidh->vol_id)) { |
801c135c AB |
1441 | ubi_err("bad vol_id %d", sv->vol_id); |
1442 | goto bad_vid_hdr; | |
1443 | } | |
1444 | ||
1445 | if (sv->compat != vidh->compat) { | |
1446 | ubi_err("bad compat %d", vidh->compat); | |
1447 | goto bad_vid_hdr; | |
1448 | } | |
1449 | ||
3261ebd7 | 1450 | if (seb->lnum != be32_to_cpu(vidh->lnum)) { |
801c135c AB |
1451 | ubi_err("bad lnum %d", seb->lnum); |
1452 | goto bad_vid_hdr; | |
1453 | } | |
1454 | ||
3261ebd7 | 1455 | if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) { |
801c135c AB |
1456 | ubi_err("bad used_ebs %d", sv->used_ebs); |
1457 | goto bad_vid_hdr; | |
1458 | } | |
1459 | ||
3261ebd7 | 1460 | if (sv->data_pad != be32_to_cpu(vidh->data_pad)) { |
801c135c AB |
1461 | ubi_err("bad data_pad %d", sv->data_pad); |
1462 | goto bad_vid_hdr; | |
1463 | } | |
801c135c AB |
1464 | } |
1465 | ||
1466 | if (!last_seb) | |
1467 | continue; | |
1468 | ||
3261ebd7 | 1469 | if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) { |
801c135c AB |
1470 | ubi_err("bad highest_lnum %d", sv->highest_lnum); |
1471 | goto bad_vid_hdr; | |
1472 | } | |
1473 | ||
3261ebd7 | 1474 | if (sv->last_data_size != be32_to_cpu(vidh->data_size)) { |
801c135c AB |
1475 | ubi_err("bad last_data_size %d", sv->last_data_size); |
1476 | goto bad_vid_hdr; | |
1477 | } | |
1478 | } | |
1479 | ||
1480 | /* | |
1481 | * Make sure that all the physical eraseblocks are in one of the lists | |
1482 | * or trees. | |
1483 | */ | |
d9b0744d | 1484 | buf = kzalloc(ubi->peb_count, GFP_KERNEL); |
801c135c AB |
1485 | if (!buf) |
1486 | return -ENOMEM; | |
1487 | ||
801c135c AB |
1488 | for (pnum = 0; pnum < ubi->peb_count; pnum++) { |
1489 | err = ubi_io_is_bad(ubi, pnum); | |
341e1a0c AB |
1490 | if (err < 0) { |
1491 | kfree(buf); | |
801c135c | 1492 | return err; |
9c9ec147 | 1493 | } else if (err) |
d9b0744d | 1494 | buf[pnum] = 1; |
801c135c AB |
1495 | } |
1496 | ||
1497 | ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) | |
1498 | ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) | |
d9b0744d | 1499 | buf[seb->pnum] = 1; |
801c135c AB |
1500 | |
1501 | list_for_each_entry(seb, &si->free, u.list) | |
d9b0744d | 1502 | buf[seb->pnum] = 1; |
801c135c AB |
1503 | |
1504 | list_for_each_entry(seb, &si->corr, u.list) | |
d9b0744d | 1505 | buf[seb->pnum] = 1; |
801c135c AB |
1506 | |
1507 | list_for_each_entry(seb, &si->erase, u.list) | |
d9b0744d | 1508 | buf[seb->pnum] = 1; |
801c135c AB |
1509 | |
1510 | list_for_each_entry(seb, &si->alien, u.list) | |
d9b0744d | 1511 | buf[seb->pnum] = 1; |
801c135c AB |
1512 | |
1513 | err = 0; | |
1514 | for (pnum = 0; pnum < ubi->peb_count; pnum++) | |
d9b0744d | 1515 | if (!buf[pnum]) { |
801c135c AB |
1516 | ubi_err("PEB %d is not referred", pnum); |
1517 | err = 1; | |
1518 | } | |
1519 | ||
1520 | kfree(buf); | |
1521 | if (err) | |
1522 | goto out; | |
1523 | return 0; | |
1524 | ||
1525 | bad_seb: | |
1526 | ubi_err("bad scanning information about LEB %d", seb->lnum); | |
1527 | ubi_dbg_dump_seb(seb, 0); | |
1528 | ubi_dbg_dump_sv(sv); | |
1529 | goto out; | |
1530 | ||
1531 | bad_sv: | |
1532 | ubi_err("bad scanning information about volume %d", sv->vol_id); | |
1533 | ubi_dbg_dump_sv(sv); | |
1534 | goto out; | |
1535 | ||
1536 | bad_vid_hdr: | |
1537 | ubi_err("bad scanning information about volume %d", sv->vol_id); | |
1538 | ubi_dbg_dump_sv(sv); | |
1539 | ubi_dbg_dump_vid_hdr(vidh); | |
1540 | ||
1541 | out: | |
1542 | ubi_dbg_dump_stack(); | |
adbf05e3 | 1543 | return -EINVAL; |
801c135c AB |
1544 | } |
1545 | ||
1546 | #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ |