drivers/mtd/ubi/scan.c

   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 /*
  22  * UBI scanning sub-system.
  23  *
  24  * This sub-system is responsible for scanning the flash media, checking UBI
  25  * headers and providing complete information about the UBI flash image.
  26  *
  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.
  31  *
  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.
  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.
  41  */
  42
  43 #include <linux/err.h>
  44 #include <linux/slab.h>
  45 #include <linux/crc32.h>
  46 #include <linux/math64.h>
  47 #include "ubi.h"
  48
  49 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  50 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
  51 #else
  52 #define paranoid_check_si(ubi, si) 0
  53 #endif
  54
  55 /* Temporary variables used during scanning */
  56 static struct ubi_ec_hdr *ech;
  57 static struct ubi_vid_hdr *vidh;
  58
  59 /**
  60  * add_to_list - add physical eraseblock to a list.
  61  * @si: scanning information
  62  * @pnum: physical eraseblock number to add
  63  * @ec: erase counter of the physical eraseblock
  64  * @list: the list to add to
  65  *
  66  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  67  * alien lists. Returns zero in case of success and a negative error code in
  68  * case of failure.
  69  */
  70 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  71                        struct list_head *list)
  72 {
  73         struct ubi_scan_leb *seb;
  74
  75         if (list == &si->free)
  76                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  77         else if (list == &si->erase)
  78                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  79         else if (list == &si->corr) {
  80                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  81                 si->corr_count += 1;
  82         } else if (list == &si->alien)
  83                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  84         else
  85                 BUG();
  86
  87         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  88         if (!seb)
  89                 return -ENOMEM;
  90
  91         seb->pnum = pnum;
  92         seb->ec = ec;
  93         list_add_tail(&seb->u.list, list);
  94         return 0;
  95 }
  96
  97 /**
  98  * validate_vid_hdr - check volume identifier header.
  99  * @vid_hdr: the volume identifier header to check
 100  * @sv: information about the volume this logical eraseblock belongs to
 101  * @pnum: physical eraseblock number the VID header came from
 102  *
 103  * This function checks that data stored in @vid_hdr is consistent. Returns
 104  * non-zero if an inconsistency was found and zero if not.
 105  *
 106  * Note, UBI does sanity check of everything it reads from the flash media.
 107  * Most of the checks are done in the I/O sub-system. Here we check that the
 108  * information in the VID header is consistent to the information in other VID
 109  * headers of the same volume.
 110  */
 111 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 112                             const struct ubi_scan_volume *sv, int pnum)
 113 {
 114         int vol_type = vid_hdr->vol_type;
 115         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 116         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 117         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 118
 119         if (sv->leb_count != 0) {
 120                 int sv_vol_type;
 121
 122                 /*
 123                  * This is not the first logical eraseblock belonging to this
 124                  * volume. Ensure that the data in its VID header is consistent
 125                  * to the data in previous logical eraseblock headers.
 126                  */
 127
 128                 if (vol_id != sv->vol_id) {
 129                         dbg_err("inconsistent vol_id");
 130                         goto bad;
 131                 }
 132
 133                 if (sv->vol_type == UBI_STATIC_VOLUME)
 134                         sv_vol_type = UBI_VID_STATIC;
 135                 else
 136                         sv_vol_type = UBI_VID_DYNAMIC;
 137
 138                 if (vol_type != sv_vol_type) {
 139                         dbg_err("inconsistent vol_type");
 140                         goto bad;
 141                 }
 142
 143                 if (used_ebs != sv->used_ebs) {
 144                         dbg_err("inconsistent used_ebs");
 145                         goto bad;
 146                 }
 147
 148                 if (data_pad != sv->data_pad) {
 149                         dbg_err("inconsistent data_pad");
 150                         goto bad;
 151                 }
 152         }
 153
 154         return 0;
 155
 156 bad:
 157         ubi_err("inconsistent VID header at PEB %d", pnum);
 158         ubi_dbg_dump_vid_hdr(vid_hdr);
 159         ubi_dbg_dump_sv(sv);
 160         return -EINVAL;
 161 }
 162
 163 /**
 164  * add_volume - add volume to the scanning information.
 165  * @si: scanning information
 166  * @vol_id: ID of the volume to add
 167  * @pnum: physical eraseblock number
 168  * @vid_hdr: volume identifier header
 169  *
 170  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 171  * present in the scanning information, this function does nothing. Otherwise
 172  * it adds corresponding volume to the scanning information. Returns a pointer
 173  * to the scanning volume object in case of success and a negative error code
 174  * in case of failure.
 175  */
 176 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 177                                           int pnum,
 178                                           const struct ubi_vid_hdr *vid_hdr)
 179 {
 180         struct ubi_scan_volume *sv;
 181         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 182
 183         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 184
 185         /* Walk the volume RB-tree to look if this volume is already present */
 186         while (*p) {
 187                 parent = *p;
 188                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 189
 190                 if (vol_id == sv->vol_id)
 191                         return sv;
 192
 193                 if (vol_id > sv->vol_id)
 194                         p = &(*p)->rb_left;
 195                 else
 196                         p = &(*p)->rb_right;
 197         }
 198
 199         /* The volume is absent - add it */
 200         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 201         if (!sv)
 202                 return ERR_PTR(-ENOMEM);
 203
 204         sv->highest_lnum = sv->leb_count = 0;
 205         sv->vol_id = vol_id;
 206         sv->root = RB_ROOT;
 207         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 208         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 209         sv->compat = vid_hdr->compat;
 210         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 211                                                             : UBI_STATIC_VOLUME;
 212         if (vol_id > si->highest_vol_id)
 213                 si->highest_vol_id = vol_id;
 214
 215         rb_link_node(&sv->rb, parent, p);
 216         rb_insert_color(&sv->rb, &si->volumes);
 217         si->vols_found += 1;
 218         dbg_bld("added volume %d", vol_id);
 219         return sv;
 220 }
 221
 222 /**
 223  * compare_lebs - find out which logical eraseblock is newer.
 224  * @ubi: UBI device description object
 225  * @seb: first logical eraseblock to compare
 226  * @pnum: physical eraseblock number of the second logical eraseblock to
 227  * compare
 228  * @vid_hdr: volume identifier header of the second logical eraseblock
 229  *
 230  * This function compares 2 copies of a LEB and informs which one is newer. In
 231  * case of success this function returns a positive value, in case of failure, a
 232  * negative error code is returned. The success return codes use the following
 233  * bits:
 234  *     o bit 0 is cleared: the first PEB (described by @seb) is newer than the
 235  *       second PEB (described by @pnum and @vid_hdr);
 236  *     o bit 0 is set: the second PEB is newer;
 237  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 238  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 239  *     o bit 2 is cleared: the older LEB is not corrupted;
 240  *     o bit 2 is set: the older LEB is corrupted.
 241  */
 242 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 243                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 244 {
 245         void *buf;
 246         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 247         uint32_t data_crc, crc;
 248         struct ubi_vid_hdr *vh = NULL;
 249         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 250
 251         if (sqnum2 == seb->sqnum) {
 252                 /*
 253                  * This must be a really ancient UBI image which has been
 254                  * created before sequence numbers support has been added. At
 255                  * that times we used 32-bit LEB versions stored in logical
 256                  * eraseblocks. That was before UBI got into mainline. We do not
 257                  * support these images anymore. Well, those images will work
 258                  * still work, but only if no unclean reboots happened.
 259                  */
 260                 ubi_err("unsupported on-flash UBI format\n");
 261                 return -EINVAL;
 262         }
 263
 264         /* Obviously the LEB with lower sequence counter is older */
 265         second_is_newer = !!(sqnum2 > seb->sqnum);
 266
 267         /*
 268          * Now we know which copy is newer. If the copy flag of the PEB with
 269          * newer version is not set, then we just return, otherwise we have to
 270          * check data CRC. For the second PEB we already have the VID header,
 271          * for the first one - we'll need to re-read it from flash.
 272          *
 273          * Note: this may be optimized so that we wouldn't read twice.
 274          */
 275
 276         if (second_is_newer) {
 277                 if (!vid_hdr->copy_flag) {
 278                         /* It is not a copy, so it is newer */
 279                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 280                                 pnum);
 281                         return 1;
 282                 }
 283         } else {
 284                 pnum = seb->pnum;
 285
 286                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 287                 if (!vh)
 288                         return -ENOMEM;
 289
 290                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 291                 if (err) {
 292                         if (err == UBI_IO_BITFLIPS)
 293                                 bitflips = 1;
 294                         else {
 295                                 dbg_err("VID of PEB %d header is bad, but it "
 296                                         "was OK earlier", pnum);
 297                                 if (err > 0)
 298                                         err = -EIO;
 299
 300                                 goto out_free_vidh;
 301                         }
 302                 }
 303
 304                 if (!vh->copy_flag) {
 305                         /* It is not a copy, so it is newer */
 306                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 307                                 pnum);
 308                         err = bitflips << 1;
 309                         goto out_free_vidh;
 310                 }
 311
 312                 vid_hdr = vh;
 313         }
 314
 315         /* Read the data of the copy and check the CRC */
 316
 317         len = be32_to_cpu(vid_hdr->data_size);
 318         buf = vmalloc(len);
 319         if (!buf) {
 320                 err = -ENOMEM;
 321                 goto out_free_vidh;
 322         }
 323
 324         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 325         if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
 326                 goto out_free_buf;
 327
 328         data_crc = be32_to_cpu(vid_hdr->data_crc);
 329         crc = crc32(UBI_CRC32_INIT, buf, len);
 330         if (crc != data_crc) {
 331                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 332                         pnum, crc, data_crc);
 333                 corrupted = 1;
 334                 bitflips = 0;
 335                 second_is_newer = !second_is_newer;
 336         } else {
 337                 dbg_bld("PEB %d CRC is OK", pnum);
 338                 bitflips = !!err;
 339         }
 340
 341         vfree(buf);
 342         ubi_free_vid_hdr(ubi, vh);
 343
 344         if (second_is_newer)
 345                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 346         else
 347                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 348
 349         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 350
 351 out_free_buf:
 352         vfree(buf);
 353 out_free_vidh:
 354         ubi_free_vid_hdr(ubi, vh);
 355         return err;
 356 }
 357
 358 /**
 359  * ubi_scan_add_used - add physical eraseblock to the scanning information.
 360  * @ubi: UBI device description object
 361  * @si: scanning information
 362  * @pnum: the physical eraseblock number
 363  * @ec: erase counter
 364  * @vid_hdr: the volume identifier header
 365  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 366  *
 367  * This function adds information about a used physical eraseblock to the
 368  * 'used' tree of the corresponding volume. The function is rather complex
 369  * because it has to handle cases when this is not the first physical
 370  * eraseblock belonging to the same logical eraseblock, and the newer one has
 371  * to be picked, while the older one has to be dropped. This function returns
 372  * zero in case of success and a negative error code in case of failure.
 373  */
 374 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 375                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 376                       int bitflips)
 377 {
 378         int err, vol_id, lnum;
 379         unsigned long long sqnum;
 380         struct ubi_scan_volume *sv;
 381         struct ubi_scan_leb *seb;
 382         struct rb_node **p, *parent = NULL;
 383
 384         vol_id = be32_to_cpu(vid_hdr->vol_id);
 385         lnum = be32_to_cpu(vid_hdr->lnum);
 386         sqnum = be64_to_cpu(vid_hdr->sqnum);
 387
 388         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
 389                 pnum, vol_id, lnum, ec, sqnum, bitflips);
 390
 391         sv = add_volume(si, vol_id, pnum, vid_hdr);
 392         if (IS_ERR(sv))
 393                 return PTR_ERR(sv);
 394
 395         if (si->max_sqnum < sqnum)
 396                 si->max_sqnum = sqnum;
 397
 398         /*
 399          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 400          * if this is the first instance of this logical eraseblock or not.
 401          */
 402         p = &sv->root.rb_node;
 403         while (*p) {
 404                 int cmp_res;
 405
 406                 parent = *p;
 407                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 408                 if (lnum != seb->lnum) {
 409                         if (lnum < seb->lnum)
 410                                 p = &(*p)->rb_left;
 411                         else
 412                                 p = &(*p)->rb_right;
 413                         continue;
 414                 }
 415
 416                 /*
 417                  * There is already a physical eraseblock describing the same
 418                  * logical eraseblock present.
 419                  */
 420
 421                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 422                         "EC %d", seb->pnum, seb->sqnum, seb->ec);
 423
 424                 /*
 425                  * Make sure that the logical eraseblocks have different
 426                  * sequence numbers. Otherwise the image is bad.
 427                  *
 428                  * However, if the sequence number is zero, we assume it must
 429                  * be an ancient UBI image from the era when UBI did not have
 430                  * sequence numbers. We still can attach these images, unless
 431                  * there is a need to distinguish between old and new
 432                  * eraseblocks, in which case we'll refuse the image in
 433                  * 'compare_lebs()'. In other words, we attach old clean
 434                  * images, but refuse attaching old images with duplicated
 435                  * logical eraseblocks because there was an unclean reboot.
 436                  */
 437                 if (seb->sqnum == sqnum && sqnum != 0) {
 438                         ubi_err("two LEBs with same sequence number %llu",
 439                                 sqnum);
 440                         ubi_dbg_dump_seb(seb, 0);
 441                         ubi_dbg_dump_vid_hdr(vid_hdr);
 442                         return -EINVAL;
 443                 }
 444
 445                 /*
 446                  * Now we have to drop the older one and preserve the newer
 447                  * one.
 448                  */
 449                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 450                 if (cmp_res < 0)
 451                         return cmp_res;
 452
 453                 if (cmp_res & 1) {
 454                         /*
 455                          * This logical eraseblock is newer than the one
 456                          * found earlier.
 457                          */
 458                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 459                         if (err)
 460                                 return err;
 461
 462                         if (cmp_res & 4)
 463                                 err = add_to_list(si, seb->pnum, seb->ec,
 464                                                   &si->corr);
 465                         else
 466                                 err = add_to_list(si, seb->pnum, seb->ec,
 467                                                   &si->erase);
 468                         if (err)
 469                                 return err;
 470
 471                         seb->ec = ec;
 472                         seb->pnum = pnum;
 473                         seb->scrub = ((cmp_res & 2) || bitflips);
 474                         seb->sqnum = sqnum;
 475
 476                         if (sv->highest_lnum == lnum)
 477                                 sv->last_data_size =
 478                                         be32_to_cpu(vid_hdr->data_size);
 479
 480                         return 0;
 481                 } else {
 482                         /*
 483                          * This logical eraseblock is older than the one found
 484                          * previously.
 485                          */
 486                         if (cmp_res & 4)
 487                                 return add_to_list(si, pnum, ec, &si->corr);
 488                         else
 489                                 return add_to_list(si, pnum, ec, &si->erase);
 490                 }
 491         }
 492
 493         /*
 494          * We've met this logical eraseblock for the first time, add it to the
 495          * scanning information.
 496          */
 497
 498         err = validate_vid_hdr(vid_hdr, sv, pnum);
 499         if (err)
 500                 return err;
 501
 502         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 503         if (!seb)
 504                 return -ENOMEM;
 505
 506         seb->ec = ec;
 507         seb->pnum = pnum;
 508         seb->lnum = lnum;
 509         seb->sqnum = sqnum;
 510         seb->scrub = bitflips;
 511
 512         if (sv->highest_lnum <= lnum) {
 513                 sv->highest_lnum = lnum;
 514                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 515         }
 516
 517         sv->leb_count += 1;
 518         rb_link_node(&seb->u.rb, parent, p);
 519         rb_insert_color(&seb->u.rb, &sv->root);
 520         return 0;
 521 }
 522
 523 /**
 524  * ubi_scan_find_sv - find volume in the scanning information.
 525  * @si: scanning information
 526  * @vol_id: the requested volume ID
 527  *
 528  * This function returns a pointer to the volume description or %NULL if there
 529  * are no data about this volume in the scanning information.
 530  */
 531 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 532                                          int vol_id)
 533 {
 534         struct ubi_scan_volume *sv;
 535         struct rb_node *p = si->volumes.rb_node;
 536
 537         while (p) {
 538                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 539
 540                 if (vol_id == sv->vol_id)
 541                         return sv;
 542
 543                 if (vol_id > sv->vol_id)
 544                         p = p->rb_left;
 545                 else
 546                         p = p->rb_right;
 547         }
 548
 549         return NULL;
 550 }
 551
 552 /**
 553  * ubi_scan_find_seb - find LEB in the volume scanning information.
 554  * @sv: a pointer to the volume scanning information
 555  * @lnum: the requested logical eraseblock
 556  *
 557  * This function returns a pointer to the scanning logical eraseblock or %NULL
 558  * if there are no data about it in the scanning volume information.
 559  */
 560 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 561                                        int lnum)
 562 {
 563         struct ubi_scan_leb *seb;
 564         struct rb_node *p = sv->root.rb_node;
 565
 566         while (p) {
 567                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 568
 569                 if (lnum == seb->lnum)
 570                         return seb;
 571
 572                 if (lnum > seb->lnum)
 573                         p = p->rb_left;
 574                 else
 575                         p = p->rb_right;
 576         }
 577
 578         return NULL;
 579 }
 580
 581 /**
 582  * ubi_scan_rm_volume - delete scanning information about a volume.
 583  * @si: scanning information
 584  * @sv: the volume scanning information to delete
 585  */
 586 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 587 {
 588         struct rb_node *rb;
 589         struct ubi_scan_leb *seb;
 590
 591         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 592
 593         while ((rb = rb_first(&sv->root))) {
 594                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 595                 rb_erase(&seb->u.rb, &sv->root);
 596                 list_add_tail(&seb->u.list, &si->erase);
 597         }
 598
 599         rb_erase(&sv->rb, &si->volumes);
 600         kfree(sv);
 601         si->vols_found -= 1;
 602 }
 603
 604 /**
 605  * ubi_scan_erase_peb - erase a physical eraseblock.
 606  * @ubi: UBI device description object
 607  * @si: scanning information
 608  * @pnum: physical eraseblock number to erase;
 609  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 610  *
 611  * This function erases physical eraseblock 'pnum', and writes the erase
 612  * counter header to it. This function should only be used on UBI device
 613  * initialization stages, when the EBA sub-system had not been yet initialized.
 614  * This function returns zero in case of success and a negative error code in
 615  * case of failure.
 616  */
 617 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 618                        int pnum, int ec)
 619 {
 620         int err;
 621         struct ubi_ec_hdr *ec_hdr;
 622
 623         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 624                 /*
 625                  * Erase counter overflow. Upgrade UBI and use 64-bit
 626                  * erase counters internally.
 627                  */
 628                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 629                 return -EINVAL;
 630         }
 631
 632         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 633         if (!ec_hdr)
 634                 return -ENOMEM;
 635
 636         ec_hdr->ec = cpu_to_be64(ec);
 637
 638         err = ubi_io_sync_erase(ubi, pnum, 0);
 639         if (err < 0)
 640                 goto out_free;
 641
 642         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 643
 644 out_free:
 645         kfree(ec_hdr);
 646         return err;
 647 }
 648
 649 /**
 650  * ubi_scan_get_free_peb - get a free physical eraseblock.
 651  * @ubi: UBI device description object
 652  * @si: scanning information
 653  *
 654  * This function returns a free physical eraseblock. It is supposed to be
 655  * called on the UBI initialization stages when the wear-leveling sub-system is
 656  * not initialized yet. This function picks a physical eraseblocks from one of
 657  * the lists, writes the EC header if it is needed, and removes it from the
 658  * list.
 659  *
 660  * This function returns scanning physical eraseblock information in case of
 661  * success and an error code in case of failure.
 662  */
 663 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 664                                            struct ubi_scan_info *si)
 665 {
 666         int err = 0, i;
 667         struct ubi_scan_leb *seb;
 668
 669         if (!list_empty(&si->free)) {
 670                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 671                 list_del(&seb->u.list);
 672                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 673                 return seb;
 674         }
 675
 676         for (i = 0; i < 2; i++) {
 677                 struct list_head *head;
 678                 struct ubi_scan_leb *tmp_seb;
 679
 680                 if (i == 0)
 681                         head = &si->erase;
 682                 else
 683                         head = &si->corr;
 684
 685                 /*
 686                  * We try to erase the first physical eraseblock from the @head
 687                  * list and pick it if we succeed, or try to erase the
 688                  * next one if not. And so forth. We don't want to take care
 689                  * about bad eraseblocks here - they'll be handled later.
 690                  */
 691                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 692                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 693                                 seb->ec = si->mean_ec;
 694
 695                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 696                         if (err)
 697                                 continue;
 698
 699                         seb->ec += 1;
 700                         list_del(&seb->u.list);
 701                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 702                         return seb;
 703                 }
 704         }
 705
 706         ubi_err("no eraseblocks found");
 707         return ERR_PTR(-ENOSPC);
 708 }
 709
 710 /**
 711  * process_eb - read, check UBI headers, and add them to scanning information.
 712  * @ubi: UBI device description object
 713  * @si: scanning information
 714  * @pnum: the physical eraseblock number
 715  *
 716  * This function returns a zero if the physical eraseblock was successfully
 717  * handled and a negative error code in case of failure.
 718  */
 719 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 720                       int pnum)
 721 {
 722         long long uninitialized_var(ec);
 723         int err, bitflips = 0, vol_id, ec_corr = 0;
 724
 725         dbg_bld("scan PEB %d", pnum);
 726
 727         /* Skip bad physical eraseblocks */
 728         err = ubi_io_is_bad(ubi, pnum);
 729         if (err < 0)
 730                 return err;
 731         else if (err) {
 732                 /*
 733                  * FIXME: this is actually duty of the I/O sub-system to
 734                  * initialize this, but MTD does not provide enough
 735                  * information.
 736                  */
 737                 si->bad_peb_count += 1;
 738                 return 0;
 739         }
 740
 741         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 742         if (err < 0)
 743                 return err;
 744         else if (err == UBI_IO_BITFLIPS)
 745                 bitflips = 1;
 746         else if (err == UBI_IO_PEB_EMPTY)
 747                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 748         else if (err == UBI_IO_BAD_EC_HDR) {
 749                 /*
 750                  * We have to also look at the VID header, possibly it is not
 751                  * corrupted. Set %bitflips flag in order to make this PEB be
 752                  * moved and EC be re-created.
 753                  */
 754                 ec_corr = 1;
 755                 ec = UBI_SCAN_UNKNOWN_EC;
 756                 bitflips = 1;
 757         }
 758
 759         si->is_empty = 0;
 760
 761         if (!ec_corr) {
 762                 int image_seq;
 763
 764                 /* Make sure UBI version is OK */
 765                 if (ech->version != UBI_VERSION) {
 766                         ubi_err("this UBI version is %d, image version is %d",
 767                                 UBI_VERSION, (int)ech->version);
 768                         return -EINVAL;
 769                 }
 770
 771                 ec = be64_to_cpu(ech->ec);
 772                 if (ec > UBI_MAX_ERASECOUNTER) {
 773                         /*
 774                          * Erase counter overflow. The EC headers have 64 bits
 775                          * reserved, but we anyway make use of only 31 bit
 776                          * values, as this seems to be enough for any existing
 777                          * flash. Upgrade UBI and use 64-bit erase counters
 778                          * internally.
 779                          */
 780                         ubi_err("erase counter overflow, max is %d",
 781                                 UBI_MAX_ERASECOUNTER);
 782                         ubi_dbg_dump_ec_hdr(ech);
 783                         return -EINVAL;
 784                 }
 785
 786                 /*
 787                  * Make sure that all PEBs have the same image sequence number.
 788                  * This allows us to detect situations when users flash UBI
 789                  * images incorrectly, so that the flash has the new UBI image
 790                  * and leftovers from the old one. This feature was added
 791                  * relatively recently, and the sequence number was always
 792                  * zero, because old UBI implementations always set it to zero.
 793                  * For this reasons, we do not panic if some PEBs have zero
 794                  * sequence number, while other PEBs have non-zero sequence
 795                  * number.
 796                  */
 797                 image_seq = be32_to_cpu(ech->image_seq);
 798                 if (!ubi->image_seq && image_seq)
 799                         ubi->image_seq = image_seq;
 800                 if (ubi->image_seq && image_seq &&
 801                     ubi->image_seq != image_seq) {
 802                         ubi_err("bad image sequence number %d in PEB %d, "
 803                                 "expected %d", image_seq, pnum, ubi->image_seq);
 804                         ubi_dbg_dump_ec_hdr(ech);
 805                         return -EINVAL;
 806                 }
 807         }
 808
 809         /* OK, we've done with the EC header, let's look at the VID header */
 810
 811         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 812         if (err < 0)
 813                 return err;
 814         else if (err == UBI_IO_BITFLIPS)
 815                 bitflips = 1;
 816         else if (err == UBI_IO_BAD_VID_HDR ||
 817                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 818                 /* VID header is corrupted */
 819                 err = add_to_list(si, pnum, ec, &si->corr);
 820                 if (err)
 821                         return err;
 822                 goto adjust_mean_ec;
 823         } else if (err == UBI_IO_PEB_FREE) {
 824                 /* No VID header - the physical eraseblock is free */
 825                 err = add_to_list(si, pnum, ec, &si->free);
 826                 if (err)
 827                         return err;
 828                 goto adjust_mean_ec;
 829         }
 830
 831         vol_id = be32_to_cpu(vidh->vol_id);
 832         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 833                 int lnum = be32_to_cpu(vidh->lnum);
 834
 835                 /* Unsupported internal volume */
 836                 switch (vidh->compat) {
 837                 case UBI_COMPAT_DELETE:
 838                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 839                                 " found, remove it", vol_id, lnum);
 840                         err = add_to_list(si, pnum, ec, &si->corr);
 841                         if (err)
 842                                 return err;
 843                         break;
 844
 845                 case UBI_COMPAT_RO:
 846                         ubi_msg("read-only compatible internal volume %d:%d"
 847                                 " found, switch to read-only mode",
 848                                 vol_id, lnum);
 849                         ubi->ro_mode = 1;
 850                         break;
 851
 852                 case UBI_COMPAT_PRESERVE:
 853                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 854                                 " found", vol_id, lnum);
 855                         err = add_to_list(si, pnum, ec, &si->alien);
 856                         if (err)
 857                                 return err;
 858                         si->alien_peb_count += 1;
 859                         return 0;
 860
 861                 case UBI_COMPAT_REJECT:
 862                         ubi_err("incompatible internal volume %d:%d found",
 863                                 vol_id, lnum);
 864                         return -EINVAL;
 865                 }
 866         }
 867
 868         if (ec_corr)
 869                 ubi_warn("valid VID header but corrupted EC header at PEB %d",
 870                          pnum);
 871         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 872         if (err)
 873                 return err;
 874
 875 adjust_mean_ec:
 876         if (!ec_corr) {
 877                 si->ec_sum += ec;
 878                 si->ec_count += 1;
 879                 if (ec > si->max_ec)
 880                         si->max_ec = ec;
 881                 if (ec < si->min_ec)
 882                         si->min_ec = ec;
 883         }
 884
 885         return 0;
 886 }
 887
 888 /**
 889  * ubi_scan - scan an MTD device.
 890  * @ubi: UBI device description object
 891  *
 892  * This function does full scanning of an MTD device and returns complete
 893  * information about it. In case of failure, an error code is returned.
 894  */
 895 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 896 {
 897         int err, pnum;
 898         struct rb_node *rb1, *rb2;
 899         struct ubi_scan_volume *sv;
 900         struct ubi_scan_leb *seb;
 901         struct ubi_scan_info *si;
 902
 903         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 904         if (!si)
 905                 return ERR_PTR(-ENOMEM);
 906
 907         INIT_LIST_HEAD(&si->corr);
 908         INIT_LIST_HEAD(&si->free);
 909         INIT_LIST_HEAD(&si->erase);
 910         INIT_LIST_HEAD(&si->alien);
 911         si->volumes = RB_ROOT;
 912         si->is_empty = 1;
 913
 914         err = -ENOMEM;
 915         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 916         if (!ech)
 917                 goto out_si;
 918
 919         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 920         if (!vidh)
 921                 goto out_ech;
 922
 923         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 924                 cond_resched();
 925
 926                 dbg_gen("process PEB %d", pnum);
 927                 err = process_eb(ubi, si, pnum);
 928                 if (err < 0)
 929                         goto out_vidh;
 930         }
 931
 932         dbg_msg("scanning is finished");
 933
 934         /* Calculate mean erase counter */
 935         if (si->ec_count)
 936                 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
 937
 938         if (si->is_empty)
 939                 ubi_msg("empty MTD device detected");
 940
 941         /*
 942          * Few corrupted PEBs are not a problem and may be just a result of
 943          * unclean reboots. However, many of them may indicate some problems
 944          * with the flash HW or driver. Print a warning in this case.
 945          */
 946         if (si->corr_count >= 8 || si->corr_count >= ubi->peb_count / 4) {
 947                 ubi_warn("%d PEBs are corrupted", si->corr_count);
 948                 printk(KERN_WARNING "corrupted PEBs are:");
 949                 list_for_each_entry(seb, &si->corr, u.list)
 950                         printk(KERN_CONT " %d", seb->pnum);
 951                 printk(KERN_CONT "\n");
 952         }
 953
 954         /*
 955          * In case of unknown erase counter we use the mean erase counter
 956          * value.
 957          */
 958         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 959                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 960                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 961                                 seb->ec = si->mean_ec;
 962         }
 963
 964         list_for_each_entry(seb, &si->free, u.list) {
 965                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 966                         seb->ec = si->mean_ec;
 967         }
 968
 969         list_for_each_entry(seb, &si->corr, u.list)
 970                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 971                         seb->ec = si->mean_ec;
 972
 973         list_for_each_entry(seb, &si->erase, u.list)
 974                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 975                         seb->ec = si->mean_ec;
 976
 977         err = paranoid_check_si(ubi, si);
 978         if (err)
 979                 goto out_vidh;
 980
 981         ubi_free_vid_hdr(ubi, vidh);
 982         kfree(ech);
 983
 984         return si;
 985
 986 out_vidh:
 987         ubi_free_vid_hdr(ubi, vidh);
 988 out_ech:
 989         kfree(ech);
 990 out_si:
 991         ubi_scan_destroy_si(si);
 992         return ERR_PTR(err);
 993 }
 994
 995 /**
 996  * destroy_sv - free the scanning volume information
 997  * @sv: scanning volume information
 998  *
 999  * This function destroys the volume RB-tree (@sv->root) and the scanning
1000  * volume information.
1001  */
1002 static void destroy_sv(struct ubi_scan_volume *sv)
1003 {
1004         struct ubi_scan_leb *seb;
1005         struct rb_node *this = sv->root.rb_node;
1006
1007         while (this) {
1008                 if (this->rb_left)
1009                         this = this->rb_left;
1010                 else if (this->rb_right)
1011                         this = this->rb_right;
1012                 else {
1013                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1014                         this = rb_parent(this);
1015                         if (this) {
1016                                 if (this->rb_left == &seb->u.rb)
1017                                         this->rb_left = NULL;
1018                                 else
1019                                         this->rb_right = NULL;
1020                         }
1021
1022                         kfree(seb);
1023                 }
1024         }
1025         kfree(sv);
1026 }
1027
1028 /**
1029  * ubi_scan_destroy_si - destroy scanning information.
1030  * @si: scanning information
1031  */
1032 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1033 {
1034         struct ubi_scan_leb *seb, *seb_tmp;
1035         struct ubi_scan_volume *sv;
1036         struct rb_node *rb;
1037
1038         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1039                 list_del(&seb->u.list);
1040                 kfree(seb);
1041         }
1042         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1043                 list_del(&seb->u.list);
1044                 kfree(seb);
1045         }
1046         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1047                 list_del(&seb->u.list);
1048                 kfree(seb);
1049         }
1050         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1051                 list_del(&seb->u.list);
1052                 kfree(seb);
1053         }
1054
1055         /* Destroy the volume RB-tree */
1056         rb = si->volumes.rb_node;
1057         while (rb) {
1058                 if (rb->rb_left)
1059                         rb = rb->rb_left;
1060                 else if (rb->rb_right)
1061                         rb = rb->rb_right;
1062                 else {
1063                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1064
1065                         rb = rb_parent(rb);
1066                         if (rb) {
1067                                 if (rb->rb_left == &sv->rb)
1068                                         rb->rb_left = NULL;
1069                                 else
1070                                         rb->rb_right = NULL;
1071                         }
1072
1073                         destroy_sv(sv);
1074                 }
1075         }
1076
1077         kfree(si);
1078 }
1079
1080 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1081
1082 /**
1083  * paranoid_check_si - check the scanning information.
1084  * @ubi: UBI device description object
1085  * @si: scanning information
1086  *
1087  * This function returns zero if the scanning information is all right, and a
1088  * negative error code if not or if an error occurred.
1089  */
1090 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1091 {
1092         int pnum, err, vols_found = 0;
1093         struct rb_node *rb1, *rb2;
1094         struct ubi_scan_volume *sv;
1095         struct ubi_scan_leb *seb, *last_seb;
1096         uint8_t *buf;
1097
1098         /*
1099          * At first, check that scanning information is OK.
1100          */
1101         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1102                 int leb_count = 0;
1103
1104                 cond_resched();
1105
1106                 vols_found += 1;
1107
1108                 if (si->is_empty) {
1109                         ubi_err("bad is_empty flag");
1110                         goto bad_sv;
1111                 }
1112
1113                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1114                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1115                     sv->data_pad < 0 || sv->last_data_size < 0) {
1116                         ubi_err("negative values");
1117                         goto bad_sv;
1118                 }
1119
1120                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1121                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1122                         ubi_err("bad vol_id");
1123                         goto bad_sv;
1124                 }
1125
1126                 if (sv->vol_id > si->highest_vol_id) {
1127                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1128                                 si->highest_vol_id, sv->vol_id);
1129                         goto out;
1130                 }
1131
1132                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1133                     sv->vol_type != UBI_STATIC_VOLUME) {
1134                         ubi_err("bad vol_type");
1135                         goto bad_sv;
1136                 }
1137
1138                 if (sv->data_pad > ubi->leb_size / 2) {
1139                         ubi_err("bad data_pad");
1140                         goto bad_sv;
1141                 }
1142
1143                 last_seb = NULL;
1144                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1145                         cond_resched();
1146
1147                         last_seb = seb;
1148                         leb_count += 1;
1149
1150                         if (seb->pnum < 0 || seb->ec < 0) {
1151                                 ubi_err("negative values");
1152                                 goto bad_seb;
1153                         }
1154
1155                         if (seb->ec < si->min_ec) {
1156                                 ubi_err("bad si->min_ec (%d), %d found",
1157                                         si->min_ec, seb->ec);
1158                                 goto bad_seb;
1159                         }
1160
1161                         if (seb->ec > si->max_ec) {
1162                                 ubi_err("bad si->max_ec (%d), %d found",
1163                                         si->max_ec, seb->ec);
1164                                 goto bad_seb;
1165                         }
1166
1167                         if (seb->pnum >= ubi->peb_count) {
1168                                 ubi_err("too high PEB number %d, total PEBs %d",
1169                                         seb->pnum, ubi->peb_count);
1170                                 goto bad_seb;
1171                         }
1172
1173                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1174                                 if (seb->lnum >= sv->used_ebs) {
1175                                         ubi_err("bad lnum or used_ebs");
1176                                         goto bad_seb;
1177                                 }
1178                         } else {
1179                                 if (sv->used_ebs != 0) {
1180                                         ubi_err("non-zero used_ebs");
1181                                         goto bad_seb;
1182                                 }
1183                         }
1184
1185                         if (seb->lnum > sv->highest_lnum) {
1186                                 ubi_err("incorrect highest_lnum or lnum");
1187                                 goto bad_seb;
1188                         }
1189                 }
1190
1191                 if (sv->leb_count != leb_count) {
1192                         ubi_err("bad leb_count, %d objects in the tree",
1193                                 leb_count);
1194                         goto bad_sv;
1195                 }
1196
1197                 if (!last_seb)
1198                         continue;
1199
1200                 seb = last_seb;
1201
1202                 if (seb->lnum != sv->highest_lnum) {
1203                         ubi_err("bad highest_lnum");
1204                         goto bad_seb;
1205                 }
1206         }
1207
1208         if (vols_found != si->vols_found) {
1209                 ubi_err("bad si->vols_found %d, should be %d",
1210                         si->vols_found, vols_found);
1211                 goto out;
1212         }
1213
1214         /* Check that scanning information is correct */
1215         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1216                 last_seb = NULL;
1217                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1218                         int vol_type;
1219
1220                         cond_resched();
1221
1222                         last_seb = seb;
1223
1224                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1225                         if (err && err != UBI_IO_BITFLIPS) {
1226                                 ubi_err("VID header is not OK (%d)", err);
1227                                 if (err > 0)
1228                                         err = -EIO;
1229                                 return err;
1230                         }
1231
1232                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1233                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1234                         if (sv->vol_type != vol_type) {
1235                                 ubi_err("bad vol_type");
1236                                 goto bad_vid_hdr;
1237                         }
1238
1239                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1240                                 ubi_err("bad sqnum %llu", seb->sqnum);
1241                                 goto bad_vid_hdr;
1242                         }
1243
1244                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1245                                 ubi_err("bad vol_id %d", sv->vol_id);
1246                                 goto bad_vid_hdr;
1247                         }
1248
1249                         if (sv->compat != vidh->compat) {
1250                                 ubi_err("bad compat %d", vidh->compat);
1251                                 goto bad_vid_hdr;
1252                         }
1253
1254                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1255                                 ubi_err("bad lnum %d", seb->lnum);
1256                                 goto bad_vid_hdr;
1257                         }
1258
1259                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1260                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1261                                 goto bad_vid_hdr;
1262                         }
1263
1264                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1265                                 ubi_err("bad data_pad %d", sv->data_pad);
1266                                 goto bad_vid_hdr;
1267                         }
1268                 }
1269
1270                 if (!last_seb)
1271                         continue;
1272
1273                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1274                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1275                         goto bad_vid_hdr;
1276                 }
1277
1278                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1279                         ubi_err("bad last_data_size %d", sv->last_data_size);
1280                         goto bad_vid_hdr;
1281                 }
1282         }
1283
1284         /*
1285          * Make sure that all the physical eraseblocks are in one of the lists
1286          * or trees.
1287          */
1288         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1289         if (!buf)
1290                 return -ENOMEM;
1291
1292         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1293                 err = ubi_io_is_bad(ubi, pnum);
1294                 if (err < 0) {
1295                         kfree(buf);
1296                         return err;
1297                 } else if (err)
1298                         buf[pnum] = 1;
1299         }
1300
1301         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1302                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1303                         buf[seb->pnum] = 1;
1304
1305         list_for_each_entry(seb, &si->free, u.list)
1306                 buf[seb->pnum] = 1;
1307
1308         list_for_each_entry(seb, &si->corr, u.list)
1309                 buf[seb->pnum] = 1;
1310
1311         list_for_each_entry(seb, &si->erase, u.list)
1312                 buf[seb->pnum] = 1;
1313
1314         list_for_each_entry(seb, &si->alien, u.list)
1315                 buf[seb->pnum] = 1;
1316
1317         err = 0;
1318         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1319                 if (!buf[pnum]) {
1320                         ubi_err("PEB %d is not referred", pnum);
1321                         err = 1;
1322                 }
1323
1324         kfree(buf);
1325         if (err)
1326                 goto out;
1327         return 0;
1328
1329 bad_seb:
1330         ubi_err("bad scanning information about LEB %d", seb->lnum);
1331         ubi_dbg_dump_seb(seb, 0);
1332         ubi_dbg_dump_sv(sv);
1333         goto out;
1334
1335 bad_sv:
1336         ubi_err("bad scanning information about volume %d", sv->vol_id);
1337         ubi_dbg_dump_sv(sv);
1338         goto out;
1339
1340 bad_vid_hdr:
1341         ubi_err("bad scanning information about volume %d", sv->vol_id);
1342         ubi_dbg_dump_sv(sv);
1343         ubi_dbg_dump_vid_hdr(vidh);
1344
1345 out:
1346         ubi_dbg_dump_stack();
1347         return -EINVAL;
1348 }
1349
1350 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */