printk removal, receive reordering bugfix
[cor_2_6_31.git] / drivers / mtd / ubi / scan.c
bloba423131b617141faaaf7b998e49ceb8b23146fce
1 /*
2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Author: Artem Bityutskiy (Битюцкий Артём)
22 * UBI scanning sub-system.
24 * This sub-system is responsible for scanning the flash media, checking UBI
25 * headers and providing complete information about the UBI flash image.
27 * The scanning information is represented by a &struct ubi_scan_info' object.
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.
32 * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
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.
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.
43 #include <linux/err.h>
44 #include <linux/crc32.h>
45 #include <linux/math64.h>
46 #include "ubi.h"
48 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
49 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
50 #else
51 #define paranoid_check_si(ubi, si) 0
52 #endif
54 /* Temporary variables used during scanning */
55 static struct ubi_ec_hdr *ech;
56 static struct ubi_vid_hdr *vidh;
58 /**
59 * add_to_list - add physical eraseblock to a list.
60 * @si: scanning information
61 * @pnum: physical eraseblock number to add
62 * @ec: erase counter of the physical eraseblock
63 * @list: the list to add to
65 * This function adds physical eraseblock @pnum to free, erase, corrupted or
66 * alien lists. Returns zero in case of success and a negative error code in
67 * case of failure.
69 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
70 struct list_head *list)
72 struct ubi_scan_leb *seb;
74 if (list == &si->free)
75 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
76 else if (list == &si->erase)
77 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
78 else if (list == &si->corr)
79 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
80 else if (list == &si->alien)
81 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
82 else
83 BUG();
85 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
86 if (!seb)
87 return -ENOMEM;
89 seb->pnum = pnum;
90 seb->ec = ec;
91 list_add_tail(&seb->u.list, list);
92 return 0;
95 /**
96 * validate_vid_hdr - check volume identifier header.
97 * @vid_hdr: the volume identifier header to check
98 * @sv: information about the volume this logical eraseblock belongs to
99 * @pnum: physical eraseblock number the VID header came from
101 * This function checks that data stored in @vid_hdr is consistent. Returns
102 * non-zero if an inconsistency was found and zero if not.
104 * Note, UBI does sanity check of everything it reads from the flash media.
105 * Most of the checks are done in the I/O sub-system. Here we check that the
106 * information in the VID header is consistent to the information in other VID
107 * headers of the same volume.
109 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
110 const struct ubi_scan_volume *sv, int pnum)
112 int vol_type = vid_hdr->vol_type;
113 int vol_id = be32_to_cpu(vid_hdr->vol_id);
114 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
115 int data_pad = be32_to_cpu(vid_hdr->data_pad);
117 if (sv->leb_count != 0) {
118 int sv_vol_type;
121 * This is not the first logical eraseblock belonging to this
122 * volume. Ensure that the data in its VID header is consistent
123 * to the data in previous logical eraseblock headers.
126 if (vol_id != sv->vol_id) {
127 dbg_err("inconsistent vol_id");
128 goto bad;
131 if (sv->vol_type == UBI_STATIC_VOLUME)
132 sv_vol_type = UBI_VID_STATIC;
133 else
134 sv_vol_type = UBI_VID_DYNAMIC;
136 if (vol_type != sv_vol_type) {
137 dbg_err("inconsistent vol_type");
138 goto bad;
141 if (used_ebs != sv->used_ebs) {
142 dbg_err("inconsistent used_ebs");
143 goto bad;
146 if (data_pad != sv->data_pad) {
147 dbg_err("inconsistent data_pad");
148 goto bad;
152 return 0;
154 bad:
155 ubi_err("inconsistent VID header at PEB %d", pnum);
156 ubi_dbg_dump_vid_hdr(vid_hdr);
157 ubi_dbg_dump_sv(sv);
158 return -EINVAL;
162 * add_volume - add volume to the scanning information.
163 * @si: scanning information
164 * @vol_id: ID of the volume to add
165 * @pnum: physical eraseblock number
166 * @vid_hdr: volume identifier header
168 * If the volume corresponding to the @vid_hdr logical eraseblock is already
169 * present in the scanning information, this function does nothing. Otherwise
170 * it adds corresponding volume to the scanning information. Returns a pointer
171 * to the scanning volume object in case of success and a negative error code
172 * in case of failure.
174 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
175 int pnum,
176 const struct ubi_vid_hdr *vid_hdr)
178 struct ubi_scan_volume *sv;
179 struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
181 ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
183 /* Walk the volume RB-tree to look if this volume is already present */
184 while (*p) {
185 parent = *p;
186 sv = rb_entry(parent, struct ubi_scan_volume, rb);
188 if (vol_id == sv->vol_id)
189 return sv;
191 if (vol_id > sv->vol_id)
192 p = &(*p)->rb_left;
193 else
194 p = &(*p)->rb_right;
197 /* The volume is absent - add it */
198 sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
199 if (!sv)
200 return ERR_PTR(-ENOMEM);
202 sv->highest_lnum = sv->leb_count = 0;
203 sv->vol_id = vol_id;
204 sv->root = RB_ROOT;
205 sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
206 sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
207 sv->compat = vid_hdr->compat;
208 sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
209 : UBI_STATIC_VOLUME;
210 if (vol_id > si->highest_vol_id)
211 si->highest_vol_id = vol_id;
213 rb_link_node(&sv->rb, parent, p);
214 rb_insert_color(&sv->rb, &si->volumes);
215 si->vols_found += 1;
216 dbg_bld("added volume %d", vol_id);
217 return sv;
221 * compare_lebs - find out which logical eraseblock is newer.
222 * @ubi: UBI device description object
223 * @seb: first logical eraseblock to compare
224 * @pnum: physical eraseblock number of the second logical eraseblock to
225 * compare
226 * @vid_hdr: volume identifier header of the second logical eraseblock
228 * This function compares 2 copies of a LEB and informs which one is newer. In
229 * case of success this function returns a positive value, in case of failure, a
230 * negative error code is returned. The success return codes use the following
231 * bits:
232 * o bit 0 is cleared: the first PEB (described by @seb) is newer then the
233 * second PEB (described by @pnum and @vid_hdr);
234 * o bit 0 is set: the second PEB is newer;
235 * o bit 1 is cleared: no bit-flips were detected in the newer LEB;
236 * o bit 1 is set: bit-flips were detected in the newer LEB;
237 * o bit 2 is cleared: the older LEB is not corrupted;
238 * o bit 2 is set: the older LEB is corrupted.
240 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
241 int pnum, const struct ubi_vid_hdr *vid_hdr)
243 void *buf;
244 int len, err, second_is_newer, bitflips = 0, corrupted = 0;
245 uint32_t data_crc, crc;
246 struct ubi_vid_hdr *vh = NULL;
247 unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
249 if (sqnum2 == seb->sqnum) {
251 * This must be a really ancient UBI image which has been
252 * created before sequence numbers support has been added. At
253 * that times we used 32-bit LEB versions stored in logical
254 * eraseblocks. That was before UBI got into mainline. We do not
255 * support these images anymore. Well, those images will work
256 * still work, but only if no unclean reboots happened.
258 ubi_err("unsupported on-flash UBI format\n");
259 return -EINVAL;
262 /* Obviously the LEB with lower sequence counter is older */
263 second_is_newer = !!(sqnum2 > seb->sqnum);
266 * Now we know which copy is newer. If the copy flag of the PEB with
267 * newer version is not set, then we just return, otherwise we have to
268 * check data CRC. For the second PEB we already have the VID header,
269 * for the first one - we'll need to re-read it from flash.
271 * Note: this may be optimized so that we wouldn't read twice.
274 if (second_is_newer) {
275 if (!vid_hdr->copy_flag) {
276 /* It is not a copy, so it is newer */
277 dbg_bld("second PEB %d is newer, copy_flag is unset",
278 pnum);
279 return 1;
281 } else {
282 pnum = seb->pnum;
284 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
285 if (!vh)
286 return -ENOMEM;
288 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
289 if (err) {
290 if (err == UBI_IO_BITFLIPS)
291 bitflips = 1;
292 else {
293 dbg_err("VID of PEB %d header is bad, but it "
294 "was OK earlier", pnum);
295 if (err > 0)
296 err = -EIO;
298 goto out_free_vidh;
302 if (!vh->copy_flag) {
303 /* It is not a copy, so it is newer */
304 dbg_bld("first PEB %d is newer, copy_flag is unset",
305 pnum);
306 err = bitflips << 1;
307 goto out_free_vidh;
310 vid_hdr = vh;
313 /* Read the data of the copy and check the CRC */
315 len = be32_to_cpu(vid_hdr->data_size);
316 buf = vmalloc(len);
317 if (!buf) {
318 err = -ENOMEM;
319 goto out_free_vidh;
322 err = ubi_io_read_data(ubi, buf, pnum, 0, len);
323 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
324 goto out_free_buf;
326 data_crc = be32_to_cpu(vid_hdr->data_crc);
327 crc = crc32(UBI_CRC32_INIT, buf, len);
328 if (crc != data_crc) {
329 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
330 pnum, crc, data_crc);
331 corrupted = 1;
332 bitflips = 0;
333 second_is_newer = !second_is_newer;
334 } else {
335 dbg_bld("PEB %d CRC is OK", pnum);
336 bitflips = !!err;
339 vfree(buf);
340 ubi_free_vid_hdr(ubi, vh);
342 if (second_is_newer)
343 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
344 else
345 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
347 return second_is_newer | (bitflips << 1) | (corrupted << 2);
349 out_free_buf:
350 vfree(buf);
351 out_free_vidh:
352 ubi_free_vid_hdr(ubi, vh);
353 return err;
357 * ubi_scan_add_used - add physical eraseblock to the scanning information.
358 * @ubi: UBI device description object
359 * @si: scanning information
360 * @pnum: the physical eraseblock number
361 * @ec: erase counter
362 * @vid_hdr: the volume identifier header
363 * @bitflips: if bit-flips were detected when this physical eraseblock was read
365 * This function adds information about a used physical eraseblock to the
366 * 'used' tree of the corresponding volume. The function is rather complex
367 * because it has to handle cases when this is not the first physical
368 * eraseblock belonging to the same logical eraseblock, and the newer one has
369 * to be picked, while the older one has to be dropped. This function returns
370 * zero in case of success and a negative error code in case of failure.
372 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
373 int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
374 int bitflips)
376 int err, vol_id, lnum;
377 unsigned long long sqnum;
378 struct ubi_scan_volume *sv;
379 struct ubi_scan_leb *seb;
380 struct rb_node **p, *parent = NULL;
382 vol_id = be32_to_cpu(vid_hdr->vol_id);
383 lnum = be32_to_cpu(vid_hdr->lnum);
384 sqnum = be64_to_cpu(vid_hdr->sqnum);
386 dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
387 pnum, vol_id, lnum, ec, sqnum, bitflips);
389 sv = add_volume(si, vol_id, pnum, vid_hdr);
390 if (IS_ERR(sv))
391 return PTR_ERR(sv);
393 if (si->max_sqnum < sqnum)
394 si->max_sqnum = sqnum;
397 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
398 * if this is the first instance of this logical eraseblock or not.
400 p = &sv->root.rb_node;
401 while (*p) {
402 int cmp_res;
404 parent = *p;
405 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
406 if (lnum != seb->lnum) {
407 if (lnum < seb->lnum)
408 p = &(*p)->rb_left;
409 else
410 p = &(*p)->rb_right;
411 continue;
415 * There is already a physical eraseblock describing the same
416 * logical eraseblock present.
419 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
420 "EC %d", seb->pnum, seb->sqnum, seb->ec);
423 * Make sure that the logical eraseblocks have different
424 * sequence numbers. Otherwise the image is bad.
426 * However, if the sequence number is zero, we assume it must
427 * be an ancient UBI image from the era when UBI did not have
428 * sequence numbers. We still can attach these images, unless
429 * there is a need to distinguish between old and new
430 * eraseblocks, in which case we'll refuse the image in
431 * 'compare_lebs()'. In other words, we attach old clean
432 * images, but refuse attaching old images with duplicated
433 * logical eraseblocks because there was an unclean reboot.
435 if (seb->sqnum == sqnum && sqnum != 0) {
436 ubi_err("two LEBs with same sequence number %llu",
437 sqnum);
438 ubi_dbg_dump_seb(seb, 0);
439 ubi_dbg_dump_vid_hdr(vid_hdr);
440 return -EINVAL;
444 * Now we have to drop the older one and preserve the newer
445 * one.
447 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
448 if (cmp_res < 0)
449 return cmp_res;
451 if (cmp_res & 1) {
453 * This logical eraseblock is newer then the one
454 * found earlier.
456 err = validate_vid_hdr(vid_hdr, sv, pnum);
457 if (err)
458 return err;
460 if (cmp_res & 4)
461 err = add_to_list(si, seb->pnum, seb->ec,
462 &si->corr);
463 else
464 err = add_to_list(si, seb->pnum, seb->ec,
465 &si->erase);
466 if (err)
467 return err;
469 seb->ec = ec;
470 seb->pnum = pnum;
471 seb->scrub = ((cmp_res & 2) || bitflips);
472 seb->sqnum = sqnum;
474 if (sv->highest_lnum == lnum)
475 sv->last_data_size =
476 be32_to_cpu(vid_hdr->data_size);
478 return 0;
479 } else {
481 * This logical eraseblock is older than the one found
482 * previously.
484 if (cmp_res & 4)
485 return add_to_list(si, pnum, ec, &si->corr);
486 else
487 return add_to_list(si, pnum, ec, &si->erase);
492 * We've met this logical eraseblock for the first time, add it to the
493 * scanning information.
496 err = validate_vid_hdr(vid_hdr, sv, pnum);
497 if (err)
498 return err;
500 seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
501 if (!seb)
502 return -ENOMEM;
504 seb->ec = ec;
505 seb->pnum = pnum;
506 seb->lnum = lnum;
507 seb->sqnum = sqnum;
508 seb->scrub = bitflips;
510 if (sv->highest_lnum <= lnum) {
511 sv->highest_lnum = lnum;
512 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
515 sv->leb_count += 1;
516 rb_link_node(&seb->u.rb, parent, p);
517 rb_insert_color(&seb->u.rb, &sv->root);
518 return 0;
522 * ubi_scan_find_sv - find volume in the scanning information.
523 * @si: scanning information
524 * @vol_id: the requested volume ID
526 * This function returns a pointer to the volume description or %NULL if there
527 * are no data about this volume in the scanning information.
529 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
530 int vol_id)
532 struct ubi_scan_volume *sv;
533 struct rb_node *p = si->volumes.rb_node;
535 while (p) {
536 sv = rb_entry(p, struct ubi_scan_volume, rb);
538 if (vol_id == sv->vol_id)
539 return sv;
541 if (vol_id > sv->vol_id)
542 p = p->rb_left;
543 else
544 p = p->rb_right;
547 return NULL;
551 * ubi_scan_find_seb - find LEB in the volume scanning information.
552 * @sv: a pointer to the volume scanning information
553 * @lnum: the requested logical eraseblock
555 * This function returns a pointer to the scanning logical eraseblock or %NULL
556 * if there are no data about it in the scanning volume information.
558 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
559 int lnum)
561 struct ubi_scan_leb *seb;
562 struct rb_node *p = sv->root.rb_node;
564 while (p) {
565 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
567 if (lnum == seb->lnum)
568 return seb;
570 if (lnum > seb->lnum)
571 p = p->rb_left;
572 else
573 p = p->rb_right;
576 return NULL;
580 * ubi_scan_rm_volume - delete scanning information about a volume.
581 * @si: scanning information
582 * @sv: the volume scanning information to delete
584 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
586 struct rb_node *rb;
587 struct ubi_scan_leb *seb;
589 dbg_bld("remove scanning information about volume %d", sv->vol_id);
591 while ((rb = rb_first(&sv->root))) {
592 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
593 rb_erase(&seb->u.rb, &sv->root);
594 list_add_tail(&seb->u.list, &si->erase);
597 rb_erase(&sv->rb, &si->volumes);
598 kfree(sv);
599 si->vols_found -= 1;
603 * ubi_scan_erase_peb - erase a physical eraseblock.
604 * @ubi: UBI device description object
605 * @si: scanning information
606 * @pnum: physical eraseblock number to erase;
607 * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
609 * This function erases physical eraseblock 'pnum', and writes the erase
610 * counter header to it. This function should only be used on UBI device
611 * initialization stages, when the EBA sub-system had not been yet initialized.
612 * This function returns zero in case of success and a negative error code in
613 * case of failure.
615 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
616 int pnum, int ec)
618 int err;
619 struct ubi_ec_hdr *ec_hdr;
621 if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
623 * Erase counter overflow. Upgrade UBI and use 64-bit
624 * erase counters internally.
626 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
627 return -EINVAL;
630 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
631 if (!ec_hdr)
632 return -ENOMEM;
634 ec_hdr->ec = cpu_to_be64(ec);
636 err = ubi_io_sync_erase(ubi, pnum, 0);
637 if (err < 0)
638 goto out_free;
640 err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
642 out_free:
643 kfree(ec_hdr);
644 return err;
648 * ubi_scan_get_free_peb - get a free physical eraseblock.
649 * @ubi: UBI device description object
650 * @si: scanning information
652 * This function returns a free physical eraseblock. It is supposed to be
653 * called on the UBI initialization stages when the wear-leveling sub-system is
654 * not initialized yet. This function picks a physical eraseblocks from one of
655 * the lists, writes the EC header if it is needed, and removes it from the
656 * list.
658 * This function returns scanning physical eraseblock information in case of
659 * success and an error code in case of failure.
661 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
662 struct ubi_scan_info *si)
664 int err = 0, i;
665 struct ubi_scan_leb *seb;
667 if (!list_empty(&si->free)) {
668 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
669 list_del(&seb->u.list);
670 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
671 return seb;
674 for (i = 0; i < 2; i++) {
675 struct list_head *head;
676 struct ubi_scan_leb *tmp_seb;
678 if (i == 0)
679 head = &si->erase;
680 else
681 head = &si->corr;
684 * We try to erase the first physical eraseblock from the @head
685 * list and pick it if we succeed, or try to erase the
686 * next one if not. And so forth. We don't want to take care
687 * about bad eraseblocks here - they'll be handled later.
689 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
690 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
691 seb->ec = si->mean_ec;
693 err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
694 if (err)
695 continue;
697 seb->ec += 1;
698 list_del(&seb->u.list);
699 dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
700 return seb;
704 ubi_err("no eraseblocks found");
705 return ERR_PTR(-ENOSPC);
709 * process_eb - read, check UBI headers, and add them to scanning information.
710 * @ubi: UBI device description object
711 * @si: scanning information
712 * @pnum: the physical eraseblock number
714 * This function returns a zero if the physical eraseblock was successfully
715 * handled and a negative error code in case of failure.
717 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
718 int pnum)
720 long long uninitialized_var(ec);
721 int err, bitflips = 0, vol_id, ec_corr = 0;
723 dbg_bld("scan PEB %d", pnum);
725 /* Skip bad physical eraseblocks */
726 err = ubi_io_is_bad(ubi, pnum);
727 if (err < 0)
728 return err;
729 else if (err) {
731 * FIXME: this is actually duty of the I/O sub-system to
732 * initialize this, but MTD does not provide enough
733 * information.
735 si->bad_peb_count += 1;
736 return 0;
739 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
740 if (err < 0)
741 return err;
742 else if (err == UBI_IO_BITFLIPS)
743 bitflips = 1;
744 else if (err == UBI_IO_PEB_EMPTY)
745 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
746 else if (err == UBI_IO_BAD_EC_HDR) {
748 * We have to also look at the VID header, possibly it is not
749 * corrupted. Set %bitflips flag in order to make this PEB be
750 * moved and EC be re-created.
752 ec_corr = 1;
753 ec = UBI_SCAN_UNKNOWN_EC;
754 bitflips = 1;
757 si->is_empty = 0;
759 if (!ec_corr) {
760 int image_seq;
762 /* Make sure UBI version is OK */
763 if (ech->version != UBI_VERSION) {
764 ubi_err("this UBI version is %d, image version is %d",
765 UBI_VERSION, (int)ech->version);
766 return -EINVAL;
769 ec = be64_to_cpu(ech->ec);
770 if (ec > UBI_MAX_ERASECOUNTER) {
772 * Erase counter overflow. The EC headers have 64 bits
773 * reserved, but we anyway make use of only 31 bit
774 * values, as this seems to be enough for any existing
775 * flash. Upgrade UBI and use 64-bit erase counters
776 * internally.
778 ubi_err("erase counter overflow, max is %d",
779 UBI_MAX_ERASECOUNTER);
780 ubi_dbg_dump_ec_hdr(ech);
781 return -EINVAL;
784 image_seq = be32_to_cpu(ech->image_seq);
785 if (!si->image_seq_set) {
786 ubi->image_seq = image_seq;
787 si->image_seq_set = 1;
788 } else if (ubi->image_seq != image_seq) {
789 ubi_err("bad image sequence number %d in PEB %d, "
790 "expected %d", image_seq, pnum, ubi->image_seq);
791 ubi_dbg_dump_ec_hdr(ech);
792 return -EINVAL;
797 /* OK, we've done with the EC header, let's look at the VID header */
799 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
800 if (err < 0)
801 return err;
802 else if (err == UBI_IO_BITFLIPS)
803 bitflips = 1;
804 else if (err == UBI_IO_BAD_VID_HDR ||
805 (err == UBI_IO_PEB_FREE && ec_corr)) {
806 /* VID header is corrupted */
807 err = add_to_list(si, pnum, ec, &si->corr);
808 if (err)
809 return err;
810 goto adjust_mean_ec;
811 } else if (err == UBI_IO_PEB_FREE) {
812 /* No VID header - the physical eraseblock is free */
813 err = add_to_list(si, pnum, ec, &si->free);
814 if (err)
815 return err;
816 goto adjust_mean_ec;
819 vol_id = be32_to_cpu(vidh->vol_id);
820 if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
821 int lnum = be32_to_cpu(vidh->lnum);
823 /* Unsupported internal volume */
824 switch (vidh->compat) {
825 case UBI_COMPAT_DELETE:
826 ubi_msg("\"delete\" compatible internal volume %d:%d"
827 " found, remove it", vol_id, lnum);
828 err = add_to_list(si, pnum, ec, &si->corr);
829 if (err)
830 return err;
831 break;
833 case UBI_COMPAT_RO:
834 ubi_msg("read-only compatible internal volume %d:%d"
835 " found, switch to read-only mode",
836 vol_id, lnum);
837 ubi->ro_mode = 1;
838 break;
840 case UBI_COMPAT_PRESERVE:
841 ubi_msg("\"preserve\" compatible internal volume %d:%d"
842 " found", vol_id, lnum);
843 err = add_to_list(si, pnum, ec, &si->alien);
844 if (err)
845 return err;
846 si->alien_peb_count += 1;
847 return 0;
849 case UBI_COMPAT_REJECT:
850 ubi_err("incompatible internal volume %d:%d found",
851 vol_id, lnum);
852 return -EINVAL;
856 /* Both UBI headers seem to be fine */
857 err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
858 if (err)
859 return err;
861 adjust_mean_ec:
862 if (!ec_corr) {
863 si->ec_sum += ec;
864 si->ec_count += 1;
865 if (ec > si->max_ec)
866 si->max_ec = ec;
867 if (ec < si->min_ec)
868 si->min_ec = ec;
871 return 0;
875 * ubi_scan - scan an MTD device.
876 * @ubi: UBI device description object
878 * This function does full scanning of an MTD device and returns complete
879 * information about it. In case of failure, an error code is returned.
881 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
883 int err, pnum;
884 struct rb_node *rb1, *rb2;
885 struct ubi_scan_volume *sv;
886 struct ubi_scan_leb *seb;
887 struct ubi_scan_info *si;
889 si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
890 if (!si)
891 return ERR_PTR(-ENOMEM);
893 INIT_LIST_HEAD(&si->corr);
894 INIT_LIST_HEAD(&si->free);
895 INIT_LIST_HEAD(&si->erase);
896 INIT_LIST_HEAD(&si->alien);
897 si->volumes = RB_ROOT;
898 si->is_empty = 1;
900 err = -ENOMEM;
901 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
902 if (!ech)
903 goto out_si;
905 vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
906 if (!vidh)
907 goto out_ech;
909 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
910 cond_resched();
912 dbg_gen("process PEB %d", pnum);
913 err = process_eb(ubi, si, pnum);
914 if (err < 0)
915 goto out_vidh;
918 dbg_msg("scanning is finished");
920 /* Calculate mean erase counter */
921 if (si->ec_count)
922 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
924 if (si->is_empty)
925 ubi_msg("empty MTD device detected");
928 * In case of unknown erase counter we use the mean erase counter
929 * value.
931 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
932 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
933 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
934 seb->ec = si->mean_ec;
937 list_for_each_entry(seb, &si->free, u.list) {
938 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
939 seb->ec = si->mean_ec;
942 list_for_each_entry(seb, &si->corr, u.list)
943 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
944 seb->ec = si->mean_ec;
946 list_for_each_entry(seb, &si->erase, u.list)
947 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
948 seb->ec = si->mean_ec;
950 err = paranoid_check_si(ubi, si);
951 if (err) {
952 if (err > 0)
953 err = -EINVAL;
954 goto out_vidh;
957 ubi_free_vid_hdr(ubi, vidh);
958 kfree(ech);
960 return si;
962 out_vidh:
963 ubi_free_vid_hdr(ubi, vidh);
964 out_ech:
965 kfree(ech);
966 out_si:
967 ubi_scan_destroy_si(si);
968 return ERR_PTR(err);
972 * destroy_sv - free the scanning volume information
973 * @sv: scanning volume information
975 * This function destroys the volume RB-tree (@sv->root) and the scanning
976 * volume information.
978 static void destroy_sv(struct ubi_scan_volume *sv)
980 struct ubi_scan_leb *seb;
981 struct rb_node *this = sv->root.rb_node;
983 while (this) {
984 if (this->rb_left)
985 this = this->rb_left;
986 else if (this->rb_right)
987 this = this->rb_right;
988 else {
989 seb = rb_entry(this, struct ubi_scan_leb, u.rb);
990 this = rb_parent(this);
991 if (this) {
992 if (this->rb_left == &seb->u.rb)
993 this->rb_left = NULL;
994 else
995 this->rb_right = NULL;
998 kfree(seb);
1001 kfree(sv);
1005 * ubi_scan_destroy_si - destroy scanning information.
1006 * @si: scanning information
1008 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1010 struct ubi_scan_leb *seb, *seb_tmp;
1011 struct ubi_scan_volume *sv;
1012 struct rb_node *rb;
1014 list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1015 list_del(&seb->u.list);
1016 kfree(seb);
1018 list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1019 list_del(&seb->u.list);
1020 kfree(seb);
1022 list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1023 list_del(&seb->u.list);
1024 kfree(seb);
1026 list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1027 list_del(&seb->u.list);
1028 kfree(seb);
1031 /* Destroy the volume RB-tree */
1032 rb = si->volumes.rb_node;
1033 while (rb) {
1034 if (rb->rb_left)
1035 rb = rb->rb_left;
1036 else if (rb->rb_right)
1037 rb = rb->rb_right;
1038 else {
1039 sv = rb_entry(rb, struct ubi_scan_volume, rb);
1041 rb = rb_parent(rb);
1042 if (rb) {
1043 if (rb->rb_left == &sv->rb)
1044 rb->rb_left = NULL;
1045 else
1046 rb->rb_right = NULL;
1049 destroy_sv(sv);
1053 kfree(si);
1056 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1059 * paranoid_check_si - check the scanning information.
1060 * @ubi: UBI device description object
1061 * @si: scanning information
1063 * This function returns zero if the scanning information is all right, %1 if
1064 * not and a negative error code if an error occurred.
1066 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1068 int pnum, err, vols_found = 0;
1069 struct rb_node *rb1, *rb2;
1070 struct ubi_scan_volume *sv;
1071 struct ubi_scan_leb *seb, *last_seb;
1072 uint8_t *buf;
1075 * At first, check that scanning information is OK.
1077 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1078 int leb_count = 0;
1080 cond_resched();
1082 vols_found += 1;
1084 if (si->is_empty) {
1085 ubi_err("bad is_empty flag");
1086 goto bad_sv;
1089 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1090 sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1091 sv->data_pad < 0 || sv->last_data_size < 0) {
1092 ubi_err("negative values");
1093 goto bad_sv;
1096 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1097 sv->vol_id < UBI_INTERNAL_VOL_START) {
1098 ubi_err("bad vol_id");
1099 goto bad_sv;
1102 if (sv->vol_id > si->highest_vol_id) {
1103 ubi_err("highest_vol_id is %d, but vol_id %d is there",
1104 si->highest_vol_id, sv->vol_id);
1105 goto out;
1108 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1109 sv->vol_type != UBI_STATIC_VOLUME) {
1110 ubi_err("bad vol_type");
1111 goto bad_sv;
1114 if (sv->data_pad > ubi->leb_size / 2) {
1115 ubi_err("bad data_pad");
1116 goto bad_sv;
1119 last_seb = NULL;
1120 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1121 cond_resched();
1123 last_seb = seb;
1124 leb_count += 1;
1126 if (seb->pnum < 0 || seb->ec < 0) {
1127 ubi_err("negative values");
1128 goto bad_seb;
1131 if (seb->ec < si->min_ec) {
1132 ubi_err("bad si->min_ec (%d), %d found",
1133 si->min_ec, seb->ec);
1134 goto bad_seb;
1137 if (seb->ec > si->max_ec) {
1138 ubi_err("bad si->max_ec (%d), %d found",
1139 si->max_ec, seb->ec);
1140 goto bad_seb;
1143 if (seb->pnum >= ubi->peb_count) {
1144 ubi_err("too high PEB number %d, total PEBs %d",
1145 seb->pnum, ubi->peb_count);
1146 goto bad_seb;
1149 if (sv->vol_type == UBI_STATIC_VOLUME) {
1150 if (seb->lnum >= sv->used_ebs) {
1151 ubi_err("bad lnum or used_ebs");
1152 goto bad_seb;
1154 } else {
1155 if (sv->used_ebs != 0) {
1156 ubi_err("non-zero used_ebs");
1157 goto bad_seb;
1161 if (seb->lnum > sv->highest_lnum) {
1162 ubi_err("incorrect highest_lnum or lnum");
1163 goto bad_seb;
1167 if (sv->leb_count != leb_count) {
1168 ubi_err("bad leb_count, %d objects in the tree",
1169 leb_count);
1170 goto bad_sv;
1173 if (!last_seb)
1174 continue;
1176 seb = last_seb;
1178 if (seb->lnum != sv->highest_lnum) {
1179 ubi_err("bad highest_lnum");
1180 goto bad_seb;
1184 if (vols_found != si->vols_found) {
1185 ubi_err("bad si->vols_found %d, should be %d",
1186 si->vols_found, vols_found);
1187 goto out;
1190 /* Check that scanning information is correct */
1191 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1192 last_seb = NULL;
1193 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1194 int vol_type;
1196 cond_resched();
1198 last_seb = seb;
1200 err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1201 if (err && err != UBI_IO_BITFLIPS) {
1202 ubi_err("VID header is not OK (%d)", err);
1203 if (err > 0)
1204 err = -EIO;
1205 return err;
1208 vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1209 UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1210 if (sv->vol_type != vol_type) {
1211 ubi_err("bad vol_type");
1212 goto bad_vid_hdr;
1215 if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1216 ubi_err("bad sqnum %llu", seb->sqnum);
1217 goto bad_vid_hdr;
1220 if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1221 ubi_err("bad vol_id %d", sv->vol_id);
1222 goto bad_vid_hdr;
1225 if (sv->compat != vidh->compat) {
1226 ubi_err("bad compat %d", vidh->compat);
1227 goto bad_vid_hdr;
1230 if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1231 ubi_err("bad lnum %d", seb->lnum);
1232 goto bad_vid_hdr;
1235 if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1236 ubi_err("bad used_ebs %d", sv->used_ebs);
1237 goto bad_vid_hdr;
1240 if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1241 ubi_err("bad data_pad %d", sv->data_pad);
1242 goto bad_vid_hdr;
1246 if (!last_seb)
1247 continue;
1249 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1250 ubi_err("bad highest_lnum %d", sv->highest_lnum);
1251 goto bad_vid_hdr;
1254 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1255 ubi_err("bad last_data_size %d", sv->last_data_size);
1256 goto bad_vid_hdr;
1261 * Make sure that all the physical eraseblocks are in one of the lists
1262 * or trees.
1264 buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1265 if (!buf)
1266 return -ENOMEM;
1268 for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1269 err = ubi_io_is_bad(ubi, pnum);
1270 if (err < 0) {
1271 kfree(buf);
1272 return err;
1273 } else if (err)
1274 buf[pnum] = 1;
1277 ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1278 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1279 buf[seb->pnum] = 1;
1281 list_for_each_entry(seb, &si->free, u.list)
1282 buf[seb->pnum] = 1;
1284 list_for_each_entry(seb, &si->corr, u.list)
1285 buf[seb->pnum] = 1;
1287 list_for_each_entry(seb, &si->erase, u.list)
1288 buf[seb->pnum] = 1;
1290 list_for_each_entry(seb, &si->alien, u.list)
1291 buf[seb->pnum] = 1;
1293 err = 0;
1294 for (pnum = 0; pnum < ubi->peb_count; pnum++)
1295 if (!buf[pnum]) {
1296 ubi_err("PEB %d is not referred", pnum);
1297 err = 1;
1300 kfree(buf);
1301 if (err)
1302 goto out;
1303 return 0;
1305 bad_seb:
1306 ubi_err("bad scanning information about LEB %d", seb->lnum);
1307 ubi_dbg_dump_seb(seb, 0);
1308 ubi_dbg_dump_sv(sv);
1309 goto out;
1311 bad_sv:
1312 ubi_err("bad scanning information about volume %d", sv->vol_id);
1313 ubi_dbg_dump_sv(sv);
1314 goto out;
1316 bad_vid_hdr:
1317 ubi_err("bad scanning information about volume %d", sv->vol_id);
1318 ubi_dbg_dump_sv(sv);
1319 ubi_dbg_dump_vid_hdr(vidh);
1321 out:
1322 ubi_dbg_dump_stack();
1323 return 1;
1326 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */