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 unit.
  23  *
  24  * This unit 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/crc32.h>
  45 #include <asm/div64.h>
  46 #include "ubi.h"
  47
  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
  53
  54 /* Temporary variables used during scanning */
  55 static struct ubi_ec_hdr *ech;
  56 static struct ubi_vid_hdr *vidh;
  57
  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
  64  *
  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.
  68  */
  69 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  70                        struct list_head *list)
  71 {
  72         struct ubi_scan_leb *seb;
  73
  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();
  84
  85         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  86         if (!seb)
  87                 return -ENOMEM;
  88
  89         seb->pnum = pnum;
  90         seb->ec = ec;
  91         list_add_tail(&seb->u.list, list);
  92         return 0;
  93 }
  94
  95 /**
  96  * validate_vid_hdr - check that volume identifier header is correct and
  97  * consistent.
  98  * @vid_hdr: the volume identifier header to check
  99  * @sv: information about the volume this logical eraseblock belongs to
 100  * @pnum: physical eraseblock number the VID header came from
 101  *
 102  * This function checks that data stored in @vid_hdr is consistent. Returns
 103  * non-zero if an inconsistency was found and zero if not.
 104  *
 105  * Note, UBI does sanity check of everything it reads from the flash media.
 106  * Most of the checks are done in the I/O unit. Here we check that the
 107  * information in the VID header is consistent to the information in other VID
 108  * headers of the same volume.
 109  */
 110 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 111                             const struct ubi_scan_volume *sv, int pnum)
 112 {
 113         int vol_type = vid_hdr->vol_type;
 114         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 115         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 116         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 117
 118         if (sv->leb_count != 0) {
 119                 int sv_vol_type;
 120
 121                 /*
 122                  * This is not the first logical eraseblock belonging to this
 123                  * volume. Ensure that the data in its VID header is consistent
 124                  * to the data in previous logical eraseblock headers.
 125                  */
 126
 127                 if (vol_id != sv->vol_id) {
 128                         dbg_err("inconsistent vol_id");
 129                         goto bad;
 130                 }
 131
 132                 if (sv->vol_type == UBI_STATIC_VOLUME)
 133                         sv_vol_type = UBI_VID_STATIC;
 134                 else
 135                         sv_vol_type = UBI_VID_DYNAMIC;
 136
 137                 if (vol_type != sv_vol_type) {
 138                         dbg_err("inconsistent vol_type");
 139                         goto bad;
 140                 }
 141
 142                 if (used_ebs != sv->used_ebs) {
 143                         dbg_err("inconsistent used_ebs");
 144                         goto bad;
 145                 }
 146
 147                 if (data_pad != sv->data_pad) {
 148                         dbg_err("inconsistent data_pad");
 149                         goto bad;
 150                 }
 151         }
 152
 153         return 0;
 154
 155 bad:
 156         ubi_err("inconsistent VID header at PEB %d", pnum);
 157         ubi_dbg_dump_vid_hdr(vid_hdr);
 158         ubi_dbg_dump_sv(sv);
 159         return -EINVAL;
 160 }
 161
 162 /**
 163  * add_volume - add volume to the scanning information.
 164  * @si: scanning information
 165  * @vol_id: ID of the volume to add
 166  * @pnum: physical eraseblock number
 167  * @vid_hdr: volume identifier header
 168  *
 169  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 170  * present in the scanning information, this function does nothing. Otherwise
 171  * it adds corresponding volume to the scanning information. Returns a pointer
 172  * to the scanning volume object in case of success and a negative error code
 173  * in case of failure.
 174  */
 175 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 176                                           int pnum,
 177                                           const struct ubi_vid_hdr *vid_hdr)
 178 {
 179         struct ubi_scan_volume *sv;
 180         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 181
 182         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 183
 184         /* Walk the volume RB-tree to look if this volume is already present */
 185         while (*p) {
 186                 parent = *p;
 187                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 188
 189                 if (vol_id == sv->vol_id)
 190                         return sv;
 191
 192                 if (vol_id > sv->vol_id)
 193                         p = &(*p)->rb_left;
 194                 else
 195                         p = &(*p)->rb_right;
 196         }
 197
 198         /* The volume is absent - add it */
 199         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 200         if (!sv)
 201                 return ERR_PTR(-ENOMEM);
 202
 203         sv->highest_lnum = sv->leb_count = 0;
 204         sv->vol_id = vol_id;
 205         sv->root = RB_ROOT;
 206         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 207         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 208         sv->compat = vid_hdr->compat;
 209         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 210                                                             : UBI_STATIC_VOLUME;
 211         if (vol_id > si->highest_vol_id)
 212                 si->highest_vol_id = vol_id;
 213
 214         rb_link_node(&sv->rb, parent, p);
 215         rb_insert_color(&sv->rb, &si->volumes);
 216         si->vols_found += 1;
 217         dbg_bld("added volume %d", vol_id);
 218         return sv;
 219 }
 220
 221 /**
 222  * compare_lebs - find out which logical eraseblock is newer.
 223  * @ubi: UBI device description object
 224  * @seb: first logical eraseblock to compare
 225  * @pnum: physical eraseblock number of the second logical eraseblock to
 226  * compare
 227  * @vid_hdr: volume identifier header of the second logical eraseblock
 228  *
 229  * This function compares 2 copies of a LEB and informs which one is newer. In
 230  * case of success this function returns a positive value, in case of failure, a
 231  * negative error code is returned. The success return codes use the following
 232  * bits:
 233  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 234  *       second PEB (described by @pnum and @vid_hdr);
 235  *     o bit 0 is set: the second PEB is newer;
 236  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 237  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 238  *     o bit 2 is cleared: the older LEB is not corrupted;
 239  *     o bit 2 is set: the older LEB is corrupted.
 240  */
 241 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 242                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 243 {
 244         void *buf;
 245         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 246         uint32_t data_crc, crc;
 247         struct ubi_vid_hdr *vh = NULL;
 248         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 249
 250         if (seb->sqnum == 0 && sqnum2 == 0) {
 251                 long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
 252
 253                 /*
 254                  * UBI constantly increases the logical eraseblock version
 255                  * number and it can overflow. Thus, we have to bear in mind
 256                  * that versions that are close to %0xFFFFFFFF are less then
 257                  * versions that are close to %0.
 258                  *
 259                  * The UBI WL unit guarantees that the number of pending tasks
 260                  * is not greater then %0x7FFFFFFF. So, if the difference
 261                  * between any two versions is greater or equivalent to
 262                  * %0x7FFFFFFF, there was an overflow and the logical
 263                  * eraseblock with lower version is actually newer then the one
 264                  * with higher version.
 265                  *
 266                  * FIXME: but this is anyway obsolete and will be removed at
 267                  * some point.
 268                  */
 269                 dbg_bld("using old crappy leb_ver stuff");
 270
 271                 if (v1 == v2) {
 272                         ubi_err("PEB %d and PEB %d have the same version %lld",
 273                                 seb->pnum, pnum, v1);
 274                         return -EINVAL;
 275                 }
 276
 277                 abs = v1 - v2;
 278                 if (abs < 0)
 279                         abs = -abs;
 280
 281                 if (abs < 0x7FFFFFFF)
 282                         /* Non-overflow situation */
 283                         second_is_newer = (v2 > v1);
 284                 else
 285                         second_is_newer = (v2 < v1);
 286         } else
 287                 /* Obviously the LEB with lower sequence counter is older */
 288                 second_is_newer = sqnum2 > seb->sqnum;
 289
 290         /*
 291          * Now we know which copy is newer. If the copy flag of the PEB with
 292          * newer version is not set, then we just return, otherwise we have to
 293          * check data CRC. For the second PEB we already have the VID header,
 294          * for the first one - we'll need to re-read it from flash.
 295          *
 296          * FIXME: this may be optimized so that we wouldn't read twice.
 297          */
 298
 299         if (second_is_newer) {
 300                 if (!vid_hdr->copy_flag) {
 301                         /* It is not a copy, so it is newer */
 302                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 303                                 pnum);
 304                         return 1;
 305                 }
 306         } else {
 307                 pnum = seb->pnum;
 308
 309                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 310                 if (!vh)
 311                         return -ENOMEM;
 312
 313                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 314                 if (err) {
 315                         if (err == UBI_IO_BITFLIPS)
 316                                 bitflips = 1;
 317                         else {
 318                                 dbg_err("VID of PEB %d header is bad, but it "
 319                                         "was OK earlier", pnum);
 320                                 if (err > 0)
 321                                         err = -EIO;
 322
 323                                 goto out_free_vidh;
 324                         }
 325                 }
 326
 327                 if (!vh->copy_flag) {
 328                         /* It is not a copy, so it is newer */
 329                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 330                                 pnum);
 331                         err = bitflips << 1;
 332                         goto out_free_vidh;
 333                 }
 334
 335                 vid_hdr = vh;
 336         }
 337
 338         /* Read the data of the copy and check the CRC */
 339
 340         len = be32_to_cpu(vid_hdr->data_size);
 341         buf = vmalloc(len);
 342         if (!buf) {
 343                 err = -ENOMEM;
 344                 goto out_free_vidh;
 345         }
 346
 347         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 348         if (err && err != UBI_IO_BITFLIPS)
 349                 goto out_free_buf;
 350
 351         data_crc = be32_to_cpu(vid_hdr->data_crc);
 352         crc = crc32(UBI_CRC32_INIT, buf, len);
 353         if (crc != data_crc) {
 354                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 355                         pnum, crc, data_crc);
 356                 corrupted = 1;
 357                 bitflips = 0;
 358                 second_is_newer = !second_is_newer;
 359         } else {
 360                 dbg_bld("PEB %d CRC is OK", pnum);
 361                 bitflips = !!err;
 362         }
 363
 364         vfree(buf);
 365         ubi_free_vid_hdr(ubi, vh);
 366
 367         if (second_is_newer)
 368                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 369         else
 370                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 371
 372         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 373
 374 out_free_buf:
 375         vfree(buf);
 376 out_free_vidh:
 377         ubi_free_vid_hdr(ubi, vh);
 378         return err;
 379 }
 380
 381 /**
 382  * ubi_scan_add_used - add information about a physical eraseblock to the
 383  * scanning information.
 384  * @ubi: UBI device description object
 385  * @si: scanning information
 386  * @pnum: the physical eraseblock number
 387  * @ec: erase counter
 388  * @vid_hdr: the volume identifier header
 389  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 390  *
 391  * This function adds information about a used physical eraseblock to the
 392  * 'used' tree of the corresponding volume. The function is rather complex
 393  * because it has to handle cases when this is not the first physical
 394  * eraseblock belonging to the same logical eraseblock, and the newer one has
 395  * to be picked, while the older one has to be dropped. This function returns
 396  * zero in case of success and a negative error code in case of failure.
 397  */
 398 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 399                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 400                       int bitflips)
 401 {
 402         int err, vol_id, lnum;
 403         uint32_t leb_ver;
 404         unsigned long long sqnum;
 405         struct ubi_scan_volume *sv;
 406         struct ubi_scan_leb *seb;
 407         struct rb_node **p, *parent = NULL;
 408
 409         vol_id = be32_to_cpu(vid_hdr->vol_id);
 410         lnum = be32_to_cpu(vid_hdr->lnum);
 411         sqnum = be64_to_cpu(vid_hdr->sqnum);
 412         leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 413
 414         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 415                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 416
 417         sv = add_volume(si, vol_id, pnum, vid_hdr);
 418         if (IS_ERR(sv) < 0)
 419                 return PTR_ERR(sv);
 420
 421         if (si->max_sqnum < sqnum)
 422                 si->max_sqnum = sqnum;
 423
 424         /*
 425          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 426          * if this is the first instance of this logical eraseblock or not.
 427          */
 428         p = &sv->root.rb_node;
 429         while (*p) {
 430                 int cmp_res;
 431
 432                 parent = *p;
 433                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 434                 if (lnum != seb->lnum) {
 435                         if (lnum < seb->lnum)
 436                                 p = &(*p)->rb_left;
 437                         else
 438                                 p = &(*p)->rb_right;
 439                         continue;
 440                 }
 441
 442                 /*
 443                  * There is already a physical eraseblock describing the same
 444                  * logical eraseblock present.
 445                  */
 446
 447                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 448                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 449                         seb->leb_ver, seb->ec);
 450
 451                 /*
 452                  * Make sure that the logical eraseblocks have different
 453                  * versions. Otherwise the image is bad.
 454                  */
 455                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 456                         ubi_err("two LEBs with same version %u", leb_ver);
 457                         ubi_dbg_dump_seb(seb, 0);
 458                         ubi_dbg_dump_vid_hdr(vid_hdr);
 459                         return -EINVAL;
 460                 }
 461
 462                 /*
 463                  * Make sure that the logical eraseblocks have different
 464                  * sequence numbers. Otherwise the image is bad.
 465                  *
 466                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 467                  */
 468                 if (seb->sqnum == sqnum && sqnum != 0) {
 469                         ubi_err("two LEBs with same sequence number %llu",
 470                                 sqnum);
 471                         ubi_dbg_dump_seb(seb, 0);
 472                         ubi_dbg_dump_vid_hdr(vid_hdr);
 473                         return -EINVAL;
 474                 }
 475
 476                 /*
 477                  * Now we have to drop the older one and preserve the newer
 478                  * one.
 479                  */
 480                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 481                 if (cmp_res < 0)
 482                         return cmp_res;
 483
 484                 if (cmp_res & 1) {
 485                         /*
 486                          * This logical eraseblock is newer then the one
 487                          * found earlier.
 488                          */
 489                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 490                         if (err)
 491                                 return err;
 492
 493                         if (cmp_res & 4)
 494                                 err = add_to_list(si, seb->pnum, seb->ec,
 495                                                   &si->corr);
 496                         else
 497                                 err = add_to_list(si, seb->pnum, seb->ec,
 498                                                   &si->erase);
 499                         if (err)
 500                                 return err;
 501
 502                         seb->ec = ec;
 503                         seb->pnum = pnum;
 504                         seb->scrub = ((cmp_res & 2) || bitflips);
 505                         seb->sqnum = sqnum;
 506                         seb->leb_ver = leb_ver;
 507
 508                         if (sv->highest_lnum == lnum)
 509                                 sv->last_data_size =
 510                                         be32_to_cpu(vid_hdr->data_size);
 511
 512                         return 0;
 513                 } else {
 514                         /*
 515                          * This logical eraseblock is older then the one found
 516                          * previously.
 517                          */
 518                         if (cmp_res & 4)
 519                                 return add_to_list(si, pnum, ec, &si->corr);
 520                         else
 521                                 return add_to_list(si, pnum, ec, &si->erase);
 522                 }
 523         }
 524
 525         /*
 526          * We've met this logical eraseblock for the first time, add it to the
 527          * scanning information.
 528          */
 529
 530         err = validate_vid_hdr(vid_hdr, sv, pnum);
 531         if (err)
 532                 return err;
 533
 534         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 535         if (!seb)
 536                 return -ENOMEM;
 537
 538         seb->ec = ec;
 539         seb->pnum = pnum;
 540         seb->lnum = lnum;
 541         seb->sqnum = sqnum;
 542         seb->scrub = bitflips;
 543         seb->leb_ver = leb_ver;
 544
 545         if (sv->highest_lnum <= lnum) {
 546                 sv->highest_lnum = lnum;
 547                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 548         }
 549
 550         sv->leb_count += 1;
 551         rb_link_node(&seb->u.rb, parent, p);
 552         rb_insert_color(&seb->u.rb, &sv->root);
 553         return 0;
 554 }
 555
 556 /**
 557  * ubi_scan_find_sv - find information about a particular volume in the
 558  * scanning information.
 559  * @si: scanning information
 560  * @vol_id: the requested volume ID
 561  *
 562  * This function returns a pointer to the volume description or %NULL if there
 563  * are no data about this volume in the scanning information.
 564  */
 565 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 566                                          int vol_id)
 567 {
 568         struct ubi_scan_volume *sv;
 569         struct rb_node *p = si->volumes.rb_node;
 570
 571         while (p) {
 572                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 573
 574                 if (vol_id == sv->vol_id)
 575                         return sv;
 576
 577                 if (vol_id > sv->vol_id)
 578                         p = p->rb_left;
 579                 else
 580                         p = p->rb_right;
 581         }
 582
 583         return NULL;
 584 }
 585
 586 /**
 587  * ubi_scan_find_seb - find information about a particular logical
 588  * eraseblock in the volume scanning information.
 589  * @sv: a pointer to the volume scanning information
 590  * @lnum: the requested logical eraseblock
 591  *
 592  * This function returns a pointer to the scanning logical eraseblock or %NULL
 593  * if there are no data about it in the scanning volume information.
 594  */
 595 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 596                                        int lnum)
 597 {
 598         struct ubi_scan_leb *seb;
 599         struct rb_node *p = sv->root.rb_node;
 600
 601         while (p) {
 602                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 603
 604                 if (lnum == seb->lnum)
 605                         return seb;
 606
 607                 if (lnum > seb->lnum)
 608                         p = p->rb_left;
 609                 else
 610                         p = p->rb_right;
 611         }
 612
 613         return NULL;
 614 }
 615
 616 /**
 617  * ubi_scan_rm_volume - delete scanning information about a volume.
 618  * @si: scanning information
 619  * @sv: the volume scanning information to delete
 620  */
 621 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 622 {
 623         struct rb_node *rb;
 624         struct ubi_scan_leb *seb;
 625
 626         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 627
 628         while ((rb = rb_first(&sv->root))) {
 629                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 630                 rb_erase(&seb->u.rb, &sv->root);
 631                 list_add_tail(&seb->u.list, &si->erase);
 632         }
 633
 634         rb_erase(&sv->rb, &si->volumes);
 635         kfree(sv);
 636         si->vols_found -= 1;
 637 }
 638
 639 /**
 640  * ubi_scan_erase_peb - erase a physical eraseblock.
 641  * @ubi: UBI device description object
 642  * @si: scanning information
 643  * @pnum: physical eraseblock number to erase;
 644  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 645  *
 646  * This function erases physical eraseblock 'pnum', and writes the erase
 647  * counter header to it. This function should only be used on UBI device
 648  * initialization stages, when the EBA unit had not been yet initialized. This
 649  * function returns zero in case of success and a negative error code in case
 650  * of failure.
 651  */
 652 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 653                        int pnum, int ec)
 654 {
 655         int err;
 656         struct ubi_ec_hdr *ec_hdr;
 657
 658         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 659                 /*
 660                  * Erase counter overflow. Upgrade UBI and use 64-bit
 661                  * erase counters internally.
 662                  */
 663                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 664                 return -EINVAL;
 665         }
 666
 667         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 668         if (!ec_hdr)
 669                 return -ENOMEM;
 670
 671         ec_hdr->ec = cpu_to_be64(ec);
 672
 673         err = ubi_io_sync_erase(ubi, pnum, 0);
 674         if (err < 0)
 675                 goto out_free;
 676
 677         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 678
 679 out_free:
 680         kfree(ec_hdr);
 681         return err;
 682 }
 683
 684 /**
 685  * ubi_scan_get_free_peb - get a free physical eraseblock.
 686  * @ubi: UBI device description object
 687  * @si: scanning information
 688  *
 689  * This function returns a free physical eraseblock. It is supposed to be
 690  * called on the UBI initialization stages when the wear-leveling unit is not
 691  * initialized yet. This function picks a physical eraseblocks from one of the
 692  * lists, writes the EC header if it is needed, and removes it from the list.
 693  *
 694  * This function returns scanning physical eraseblock information in case of
 695  * success and an error code in case of failure.
 696  */
 697 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 698                                            struct ubi_scan_info *si)
 699 {
 700         int err = 0, i;
 701         struct ubi_scan_leb *seb;
 702
 703         if (!list_empty(&si->free)) {
 704                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 705                 list_del(&seb->u.list);
 706                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 707                 return seb;
 708         }
 709
 710         for (i = 0; i < 2; i++) {
 711                 struct list_head *head;
 712                 struct ubi_scan_leb *tmp_seb;
 713
 714                 if (i == 0)
 715                         head = &si->erase;
 716                 else
 717                         head = &si->corr;
 718
 719                 /*
 720                  * We try to erase the first physical eraseblock from the @head
 721                  * list and pick it if we succeed, or try to erase the
 722                  * next one if not. And so forth. We don't want to take care
 723                  * about bad eraseblocks here - they'll be handled later.
 724                  */
 725                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 726                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 727                                 seb->ec = si->mean_ec;
 728
 729                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 730                         if (err)
 731                                 continue;
 732
 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;
 737                 }
 738         }
 739
 740         ubi_err("no eraseblocks found");
 741         return ERR_PTR(-ENOSPC);
 742 }
 743
 744 /**
 745  * process_eb - read UBI headers, check them and add corresponding data
 746  * to the scanning information.
 747  * @ubi: UBI device description object
 748  * @si: scanning information
 749  * @pnum: the physical eraseblock number
 750  *
 751  * This function returns a zero if the physical eraseblock was successfully
 752  * handled and a negative error code in case of failure.
 753  */
 754 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 755 {
 756         long long uninitialized_var(ec);
 757         int err, bitflips = 0, vol_id, ec_corr = 0;
 758
 759         dbg_bld("scan PEB %d", pnum);
 760
 761         /* Skip bad physical eraseblocks */
 762         err = ubi_io_is_bad(ubi, pnum);
 763         if (err < 0)
 764                 return err;
 765         else if (err) {
 766                 /*
 767                  * FIXME: this is actually duty of the I/O unit to initialize
 768                  * this, but MTD does not provide enough information.
 769                  */
 770                 si->bad_peb_count += 1;
 771                 return 0;
 772         }
 773
 774         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 775         if (err < 0)
 776                 return err;
 777         else if (err == UBI_IO_BITFLIPS)
 778                 bitflips = 1;
 779         else if (err == UBI_IO_PEB_EMPTY)
 780                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 781         else if (err == UBI_IO_BAD_EC_HDR) {
 782                 /*
 783                  * We have to also look at the VID header, possibly it is not
 784                  * corrupted. Set %bitflips flag in order to make this PEB be
 785                  * moved and EC be re-created.
 786                  */
 787                 ec_corr = 1;
 788                 ec = UBI_SCAN_UNKNOWN_EC;
 789                 bitflips = 1;
 790         }
 791
 792         si->is_empty = 0;
 793
 794         if (!ec_corr) {
 795                 /* Make sure UBI version is OK */
 796                 if (ech->version != UBI_VERSION) {
 797                         ubi_err("this UBI version is %d, image version is %d",
 798                                 UBI_VERSION, (int)ech->version);
 799                         return -EINVAL;
 800                 }
 801
 802                 ec = be64_to_cpu(ech->ec);
 803                 if (ec > UBI_MAX_ERASECOUNTER) {
 804                         /*
 805                          * Erase counter overflow. The EC headers have 64 bits
 806                          * reserved, but we anyway make use of only 31 bit
 807                          * values, as this seems to be enough for any existing
 808                          * flash. Upgrade UBI and use 64-bit erase counters
 809                          * internally.
 810                          */
 811                         ubi_err("erase counter overflow, max is %d",
 812                                 UBI_MAX_ERASECOUNTER);
 813                         ubi_dbg_dump_ec_hdr(ech);
 814                         return -EINVAL;
 815                 }
 816         }
 817
 818         /* OK, we've done with the EC header, let's look at the VID header */
 819
 820         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 821         if (err < 0)
 822                 return err;
 823         else if (err == UBI_IO_BITFLIPS)
 824                 bitflips = 1;
 825         else if (err == UBI_IO_BAD_VID_HDR ||
 826                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 827                 /* VID header is corrupted */
 828                 err = add_to_list(si, pnum, ec, &si->corr);
 829                 if (err)
 830                         return err;
 831                 goto adjust_mean_ec;
 832         } else if (err == UBI_IO_PEB_FREE) {
 833                 /* No VID header - the physical eraseblock is free */
 834                 err = add_to_list(si, pnum, ec, &si->free);
 835                 if (err)
 836                         return err;
 837                 goto adjust_mean_ec;
 838         }
 839
 840         vol_id = be32_to_cpu(vidh->vol_id);
 841         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 842                 int lnum = be32_to_cpu(vidh->lnum);
 843
 844                 /* Unsupported internal volume */
 845                 switch (vidh->compat) {
 846                 case UBI_COMPAT_DELETE:
 847                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 848                                 " found, remove it", vol_id, lnum);
 849                         err = add_to_list(si, pnum, ec, &si->corr);
 850                         if (err)
 851                                 return err;
 852                         break;
 853
 854                 case UBI_COMPAT_RO:
 855                         ubi_msg("read-only compatible internal volume %d:%d"
 856                                 " found, switch to read-only mode",
 857                                 vol_id, lnum);
 858                         ubi->ro_mode = 1;
 859                         break;
 860
 861                 case UBI_COMPAT_PRESERVE:
 862                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 863                                 " found", vol_id, lnum);
 864                         err = add_to_list(si, pnum, ec, &si->alien);
 865                         if (err)
 866                                 return err;
 867                         si->alien_peb_count += 1;
 868                         return 0;
 869
 870                 case UBI_COMPAT_REJECT:
 871                         ubi_err("incompatible internal volume %d:%d found",
 872                                 vol_id, lnum);
 873                         return -EINVAL;
 874                 }
 875         }
 876
 877         /* Both UBI headers seem to be fine */
 878         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 879         if (err)
 880                 return err;
 881
 882 adjust_mean_ec:
 883         if (!ec_corr) {
 884                 si->ec_sum += ec;
 885                 si->ec_count += 1;
 886                 if (ec > si->max_ec)
 887                         si->max_ec = ec;
 888                 if (ec < si->min_ec)
 889                         si->min_ec = ec;
 890         }
 891
 892         return 0;
 893 }
 894
 895 /**
 896  * ubi_scan - scan an MTD device.
 897  * @ubi: UBI device description object
 898  *
 899  * This function does full scanning of an MTD device and returns complete
 900  * information about it. In case of failure, an error code is returned.
 901  */
 902 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 903 {
 904         int err, pnum;
 905         struct rb_node *rb1, *rb2;
 906         struct ubi_scan_volume *sv;
 907         struct ubi_scan_leb *seb;
 908         struct ubi_scan_info *si;
 909
 910         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 911         if (!si)
 912                 return ERR_PTR(-ENOMEM);
 913
 914         INIT_LIST_HEAD(&si->corr);
 915         INIT_LIST_HEAD(&si->free);
 916         INIT_LIST_HEAD(&si->erase);
 917         INIT_LIST_HEAD(&si->alien);
 918         si->volumes = RB_ROOT;
 919         si->is_empty = 1;
 920
 921         err = -ENOMEM;
 922         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 923         if (!ech)
 924                 goto out_si;
 925
 926         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 927         if (!vidh)
 928                 goto out_ech;
 929
 930         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 931                 cond_resched();
 932
 933                 dbg_msg("process PEB %d", pnum);
 934                 err = process_eb(ubi, si, pnum);
 935                 if (err < 0)
 936                         goto out_vidh;
 937         }
 938
 939         dbg_msg("scanning is finished");
 940
 941         /* Calculate mean erase counter */
 942         if (si->ec_count) {
 943                 do_div(si->ec_sum, si->ec_count);
 944                 si->mean_ec = si->ec_sum;
 945         }
 946
 947         if (si->is_empty)
 948                 ubi_msg("empty MTD device detected");
 949
 950         /*
 951          * In case of unknown erase counter we use the mean erase counter
 952          * value.
 953          */
 954         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 955                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 956                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 957                                 seb->ec = si->mean_ec;
 958         }
 959
 960         list_for_each_entry(seb, &si->free, u.list) {
 961                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 962                         seb->ec = si->mean_ec;
 963         }
 964
 965         list_for_each_entry(seb, &si->corr, u.list)
 966                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 967                         seb->ec = si->mean_ec;
 968
 969         list_for_each_entry(seb, &si->erase, u.list)
 970                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 971                         seb->ec = si->mean_ec;
 972
 973         err = paranoid_check_si(ubi, si);
 974         if (err) {
 975                 if (err > 0)
 976                         err = -EINVAL;
 977                 goto out_vidh;
 978         }
 979
 980         ubi_free_vid_hdr(ubi, vidh);
 981         kfree(ech);
 982
 983         return si;
 984
 985 out_vidh:
 986         ubi_free_vid_hdr(ubi, vidh);
 987 out_ech:
 988         kfree(ech);
 989 out_si:
 990         ubi_scan_destroy_si(si);
 991         return ERR_PTR(err);
 992 }
 993
 994 /**
 995  * destroy_sv - free the scanning volume information
 996  * @sv: scanning volume information
 997  *
 998  * This function destroys the volume RB-tree (@sv->root) and the scanning
 999  * volume information.
1000  */
1001 static void destroy_sv(struct ubi_scan_volume *sv)
1002 {
1003         struct ubi_scan_leb *seb;
1004         struct rb_node *this = sv->root.rb_node;
1005
1006         while (this) {
1007                 if (this->rb_left)
1008                         this = this->rb_left;
1009                 else if (this->rb_right)
1010                         this = this->rb_right;
1011                 else {
1012                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1013                         this = rb_parent(this);
1014                         if (this) {
1015                                 if (this->rb_left == &seb->u.rb)
1016                                         this->rb_left = NULL;
1017                                 else
1018                                         this->rb_right = NULL;
1019                         }
1020
1021                         kfree(seb);
1022                 }
1023         }
1024         kfree(sv);
1025 }
1026
1027 /**
1028  * ubi_scan_destroy_si - destroy scanning information.
1029  * @si: scanning information
1030  */
1031 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1032 {
1033         struct ubi_scan_leb *seb, *seb_tmp;
1034         struct ubi_scan_volume *sv;
1035         struct rb_node *rb;
1036
1037         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1038                 list_del(&seb->u.list);
1039                 kfree(seb);
1040         }
1041         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1042                 list_del(&seb->u.list);
1043                 kfree(seb);
1044         }
1045         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1046                 list_del(&seb->u.list);
1047                 kfree(seb);
1048         }
1049         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1050                 list_del(&seb->u.list);
1051                 kfree(seb);
1052         }
1053
1054         /* Destroy the volume RB-tree */
1055         rb = si->volumes.rb_node;
1056         while (rb) {
1057                 if (rb->rb_left)
1058                         rb = rb->rb_left;
1059                 else if (rb->rb_right)
1060                         rb = rb->rb_right;
1061                 else {
1062                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1063
1064                         rb = rb_parent(rb);
1065                         if (rb) {
1066                                 if (rb->rb_left == &sv->rb)
1067                                         rb->rb_left = NULL;
1068                                 else
1069                                         rb->rb_right = NULL;
1070                         }
1071
1072                         destroy_sv(sv);
1073                 }
1074         }
1075
1076         kfree(si);
1077 }
1078
1079 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1080
1081 /**
1082  * paranoid_check_si - check if the scanning information is correct and
1083  * consistent.
1084  * @ubi: UBI device description object
1085  * @si: scanning information
1086  *
1087  * This function returns zero if the scanning information is all right, %1 if
1088  * not and a negative error code 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                         if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
1270                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1271                                 goto bad_vid_hdr;
1272                         }
1273                 }
1274
1275                 if (!last_seb)
1276                         continue;
1277
1278                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1279                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1280                         goto bad_vid_hdr;
1281                 }
1282
1283                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1284                         ubi_err("bad last_data_size %d", sv->last_data_size);
1285                         goto bad_vid_hdr;
1286                 }
1287         }
1288
1289         /*
1290          * Make sure that all the physical eraseblocks are in one of the lists
1291          * or trees.
1292          */
1293         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1294         if (!buf)
1295                 return -ENOMEM;
1296
1297         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1298                 err = ubi_io_is_bad(ubi, pnum);
1299                 if (err < 0) {
1300                         kfree(buf);
1301                         return err;
1302                 }
1303                 else if (err)
1304                         buf[pnum] = 1;
1305         }
1306
1307         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1308                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1309                         buf[seb->pnum] = 1;
1310
1311         list_for_each_entry(seb, &si->free, u.list)
1312                 buf[seb->pnum] = 1;
1313
1314         list_for_each_entry(seb, &si->corr, u.list)
1315                 buf[seb->pnum] = 1;
1316
1317         list_for_each_entry(seb, &si->erase, u.list)
1318                 buf[seb->pnum] = 1;
1319
1320         list_for_each_entry(seb, &si->alien, u.list)
1321                 buf[seb->pnum] = 1;
1322
1323         err = 0;
1324         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1325                 if (!buf[pnum]) {
1326                         ubi_err("PEB %d is not referred", pnum);
1327                         err = 1;
1328                 }
1329
1330         kfree(buf);
1331         if (err)
1332                 goto out;
1333         return 0;
1334
1335 bad_seb:
1336         ubi_err("bad scanning information about LEB %d", seb->lnum);
1337         ubi_dbg_dump_seb(seb, 0);
1338         ubi_dbg_dump_sv(sv);
1339         goto out;
1340
1341 bad_sv:
1342         ubi_err("bad scanning information about volume %d", sv->vol_id);
1343         ubi_dbg_dump_sv(sv);
1344         goto out;
1345
1346 bad_vid_hdr:
1347         ubi_err("bad scanning information about volume %d", sv->vol_id);
1348         ubi_dbg_dump_sv(sv);
1349         ubi_dbg_dump_vid_hdr(vidh);
1350
1351 out:
1352         ubi_dbg_dump_stack();
1353         return 1;
1354 }
1355
1356 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */