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 #ifdef UBI_LINUX
  44 #include <linux/err.h>
  45 #include <linux/crc32.h>
  46 #include <asm/div64.h>
  47 #endif
  48
  49 #include <ubi_uboot.h>
  50 #include "ubi.h"
  51
  52 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  53 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
  54 #else
  55 #define paranoid_check_si(ubi, si) 0
  56 #endif
  57
  58 /* Temporary variables used during scanning */
  59 static struct ubi_ec_hdr *ech;
  60 static struct ubi_vid_hdr *vidh;
  61
  62 /**
  63  * add_to_list - add physical eraseblock to a list.
  64  * @si: scanning information
  65  * @pnum: physical eraseblock number to add
  66  * @ec: erase counter of the physical eraseblock
  67  * @list: the list to add to
  68  *
  69  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  70  * alien lists. Returns zero in case of success and a negative error code in
  71  * case of failure.
  72  */
  73 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  74                        struct list_head *list)
  75 {
  76         struct ubi_scan_leb *seb;
  77
  78         if (list == &si->free)
  79                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  80         else if (list == &si->erase)
  81                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  82         else if (list == &si->corr)
  83                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  84         else if (list == &si->alien)
  85                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  86         else
  87                 BUG();
  88
  89         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  90         if (!seb)
  91                 return -ENOMEM;
  92
  93         seb->pnum = pnum;
  94         seb->ec = ec;
  95         list_add_tail(&seb->u.list, list);
  96         return 0;
  97 }
  98
  99 /**
 100  * validate_vid_hdr - check that volume identifier header is correct and
 101  * consistent.
 102  * @vid_hdr: the volume identifier header to check
 103  * @sv: information about the volume this logical eraseblock belongs to
 104  * @pnum: physical eraseblock number the VID header came from
 105  *
 106  * This function checks that data stored in @vid_hdr is consistent. Returns
 107  * non-zero if an inconsistency was found and zero if not.
 108  *
 109  * Note, UBI does sanity check of everything it reads from the flash media.
 110  * Most of the checks are done in the I/O unit. Here we check that the
 111  * information in the VID header is consistent to the information in other VID
 112  * headers of the same volume.
 113  */
 114 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 115                             const struct ubi_scan_volume *sv, int pnum)
 116 {
 117         int vol_type = vid_hdr->vol_type;
 118         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 119         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 120         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 121
 122         if (sv->leb_count != 0) {
 123                 int sv_vol_type;
 124
 125                 /*
 126                  * This is not the first logical eraseblock belonging to this
 127                  * volume. Ensure that the data in its VID header is consistent
 128                  * to the data in previous logical eraseblock headers.
 129                  */
 130
 131                 if (vol_id != sv->vol_id) {
 132                         dbg_err("inconsistent vol_id");
 133                         goto bad;
 134                 }
 135
 136                 if (sv->vol_type == UBI_STATIC_VOLUME)
 137                         sv_vol_type = UBI_VID_STATIC;
 138                 else
 139                         sv_vol_type = UBI_VID_DYNAMIC;
 140
 141                 if (vol_type != sv_vol_type) {
 142                         dbg_err("inconsistent vol_type");
 143                         goto bad;
 144                 }
 145
 146                 if (used_ebs != sv->used_ebs) {
 147                         dbg_err("inconsistent used_ebs");
 148                         goto bad;
 149                 }
 150
 151                 if (data_pad != sv->data_pad) {
 152                         dbg_err("inconsistent data_pad");
 153                         goto bad;
 154                 }
 155         }
 156
 157         return 0;
 158
 159 bad:
 160         ubi_err("inconsistent VID header at PEB %d", pnum);
 161         ubi_dbg_dump_vid_hdr(vid_hdr);
 162         ubi_dbg_dump_sv(sv);
 163         return -EINVAL;
 164 }
 165
 166 /**
 167  * add_volume - add volume to the scanning information.
 168  * @si: scanning information
 169  * @vol_id: ID of the volume to add
 170  * @pnum: physical eraseblock number
 171  * @vid_hdr: volume identifier header
 172  *
 173  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 174  * present in the scanning information, this function does nothing. Otherwise
 175  * it adds corresponding volume to the scanning information. Returns a pointer
 176  * to the scanning volume object in case of success and a negative error code
 177  * in case of failure.
 178  */
 179 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 180                                           int pnum,
 181                                           const struct ubi_vid_hdr *vid_hdr)
 182 {
 183         struct ubi_scan_volume *sv;
 184         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 185
 186         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 187
 188         /* Walk the volume RB-tree to look if this volume is already present */
 189         while (*p) {
 190                 parent = *p;
 191                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 192
 193                 if (vol_id == sv->vol_id)
 194                         return sv;
 195
 196                 if (vol_id > sv->vol_id)
 197                         p = &(*p)->rb_left;
 198                 else
 199                         p = &(*p)->rb_right;
 200         }
 201
 202         /* The volume is absent - add it */
 203         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 204         if (!sv)
 205                 return ERR_PTR(-ENOMEM);
 206
 207         sv->highest_lnum = sv->leb_count = 0;
 208         sv->vol_id = vol_id;
 209         sv->root = RB_ROOT;
 210         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 211         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 212         sv->compat = vid_hdr->compat;
 213         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 214                                                             : UBI_STATIC_VOLUME;
 215         if (vol_id > si->highest_vol_id)
 216                 si->highest_vol_id = vol_id;
 217
 218         rb_link_node(&sv->rb, parent, p);
 219         rb_insert_color(&sv->rb, &si->volumes);
 220         si->vols_found += 1;
 221         dbg_bld("added volume %d", vol_id);
 222         return sv;
 223 }
 224
 225 /**
 226  * compare_lebs - find out which logical eraseblock is newer.
 227  * @ubi: UBI device description object
 228  * @seb: first logical eraseblock to compare
 229  * @pnum: physical eraseblock number of the second logical eraseblock to
 230  * compare
 231  * @vid_hdr: volume identifier header of the second logical eraseblock
 232  *
 233  * This function compares 2 copies of a LEB and informs which one is newer. In
 234  * case of success this function returns a positive value, in case of failure, a
 235  * negative error code is returned. The success return codes use the following
 236  * bits:
 237  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 238  *       second PEB (described by @pnum and @vid_hdr);
 239  *     o bit 0 is set: the second PEB is newer;
 240  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 241  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 242  *     o bit 2 is cleared: the older LEB is not corrupted;
 243  *     o bit 2 is set: the older LEB is corrupted.
 244  */
 245 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 246                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 247 {
 248         void *buf;
 249         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 250         uint32_t data_crc, crc;
 251         struct ubi_vid_hdr *vh = NULL;
 252         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 253
 254         if (seb->sqnum == 0 && sqnum2 == 0) {
 255                 long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
 256
 257                 /*
 258                  * UBI constantly increases the logical eraseblock version
 259                  * number and it can overflow. Thus, we have to bear in mind
 260                  * that versions that are close to %0xFFFFFFFF are less then
 261                  * versions that are close to %0.
 262                  *
 263                  * The UBI WL unit guarantees that the number of pending tasks
 264                  * is not greater then %0x7FFFFFFF. So, if the difference
 265                  * between any two versions is greater or equivalent to
 266                  * %0x7FFFFFFF, there was an overflow and the logical
 267                  * eraseblock with lower version is actually newer then the one
 268                  * with higher version.
 269                  *
 270                  * FIXME: but this is anyway obsolete and will be removed at
 271                  * some point.
 272                  */
 273                 dbg_bld("using old crappy leb_ver stuff");
 274
 275                 if (v1 == v2) {
 276                         ubi_err("PEB %d and PEB %d have the same version %lld",
 277                                 seb->pnum, pnum, v1);
 278                         return -EINVAL;
 279                 }
 280
 281                 abs = v1 - v2;
 282                 if (abs < 0)
 283                         abs = -abs;
 284
 285                 if (abs < 0x7FFFFFFF)
 286                         /* Non-overflow situation */
 287                         second_is_newer = (v2 > v1);
 288                 else
 289                         second_is_newer = (v2 < v1);
 290         } else
 291                 /* Obviously the LEB with lower sequence counter is older */
 292                 second_is_newer = sqnum2 > seb->sqnum;
 293
 294         /*
 295          * Now we know which copy is newer. If the copy flag of the PEB with
 296          * newer version is not set, then we just return, otherwise we have to
 297          * check data CRC. For the second PEB we already have the VID header,
 298          * for the first one - we'll need to re-read it from flash.
 299          *
 300          * FIXME: this may be optimized so that we wouldn't read twice.
 301          */
 302
 303         if (second_is_newer) {
 304                 if (!vid_hdr->copy_flag) {
 305                         /* It is not a copy, so it is newer */
 306                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 307                                 pnum);
 308                         return 1;
 309                 }
 310         } else {
 311                 pnum = seb->pnum;
 312
 313                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 314                 if (!vh)
 315                         return -ENOMEM;
 316
 317                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 318                 if (err) {
 319                         if (err == UBI_IO_BITFLIPS)
 320                                 bitflips = 1;
 321                         else {
 322                                 dbg_err("VID of PEB %d header is bad, but it "
 323                                         "was OK earlier", pnum);
 324                                 if (err > 0)
 325                                         err = -EIO;
 326
 327                                 goto out_free_vidh;
 328                         }
 329                 }
 330
 331                 if (!vh->copy_flag) {
 332                         /* It is not a copy, so it is newer */
 333                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 334                                 pnum);
 335                         err = bitflips << 1;
 336                         goto out_free_vidh;
 337                 }
 338
 339                 vid_hdr = vh;
 340         }
 341
 342         /* Read the data of the copy and check the CRC */
 343
 344         len = be32_to_cpu(vid_hdr->data_size);
 345         buf = vmalloc(len);
 346         if (!buf) {
 347                 err = -ENOMEM;
 348                 goto out_free_vidh;
 349         }
 350
 351         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 352         if (err && err != UBI_IO_BITFLIPS)
 353                 goto out_free_buf;
 354
 355         data_crc = be32_to_cpu(vid_hdr->data_crc);
 356         crc = crc32(UBI_CRC32_INIT, buf, len);
 357         if (crc != data_crc) {
 358                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 359                         pnum, crc, data_crc);
 360                 corrupted = 1;
 361                 bitflips = 0;
 362                 second_is_newer = !second_is_newer;
 363         } else {
 364                 dbg_bld("PEB %d CRC is OK", pnum);
 365                 bitflips = !!err;
 366         }
 367
 368         vfree(buf);
 369         ubi_free_vid_hdr(ubi, vh);
 370
 371         if (second_is_newer)
 372                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 373         else
 374                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 375
 376         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 377
 378 out_free_buf:
 379         vfree(buf);
 380 out_free_vidh:
 381         ubi_free_vid_hdr(ubi, vh);
 382         return err;
 383 }
 384
 385 /**
 386  * ubi_scan_add_used - add information about a physical eraseblock to the
 387  * scanning information.
 388  * @ubi: UBI device description object
 389  * @si: scanning information
 390  * @pnum: the physical eraseblock number
 391  * @ec: erase counter
 392  * @vid_hdr: the volume identifier header
 393  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 394  *
 395  * This function adds information about a used physical eraseblock to the
 396  * 'used' tree of the corresponding volume. The function is rather complex
 397  * because it has to handle cases when this is not the first physical
 398  * eraseblock belonging to the same logical eraseblock, and the newer one has
 399  * to be picked, while the older one has to be dropped. This function returns
 400  * zero in case of success and a negative error code in case of failure.
 401  */
 402 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 403                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 404                       int bitflips)
 405 {
 406         int err, vol_id, lnum;
 407         uint32_t leb_ver;
 408         unsigned long long sqnum;
 409         struct ubi_scan_volume *sv;
 410         struct ubi_scan_leb *seb;
 411         struct rb_node **p, *parent = NULL;
 412
 413         vol_id = be32_to_cpu(vid_hdr->vol_id);
 414         lnum = be32_to_cpu(vid_hdr->lnum);
 415         sqnum = be64_to_cpu(vid_hdr->sqnum);
 416         leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 417
 418         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 419                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 420
 421         sv = add_volume(si, vol_id, pnum, vid_hdr);
 422         if (IS_ERR(sv) < 0)
 423                 return PTR_ERR(sv);
 424
 425         if (si->max_sqnum < sqnum)
 426                 si->max_sqnum = sqnum;
 427
 428         /*
 429          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 430          * if this is the first instance of this logical eraseblock or not.
 431          */
 432         p = &sv->root.rb_node;
 433         while (*p) {
 434                 int cmp_res;
 435
 436                 parent = *p;
 437                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 438                 if (lnum != seb->lnum) {
 439                         if (lnum < seb->lnum)
 440                                 p = &(*p)->rb_left;
 441                         else
 442                                 p = &(*p)->rb_right;
 443                         continue;
 444                 }
 445
 446                 /*
 447                  * There is already a physical eraseblock describing the same
 448                  * logical eraseblock present.
 449                  */
 450
 451                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 452                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 453                         seb->leb_ver, seb->ec);
 454
 455                 /*
 456                  * Make sure that the logical eraseblocks have different
 457                  * versions. Otherwise the image is bad.
 458                  */
 459                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 460                         ubi_err("two LEBs with same version %u", leb_ver);
 461                         ubi_dbg_dump_seb(seb, 0);
 462                         ubi_dbg_dump_vid_hdr(vid_hdr);
 463                         return -EINVAL;
 464                 }
 465
 466                 /*
 467                  * Make sure that the logical eraseblocks have different
 468                  * sequence numbers. Otherwise the image is bad.
 469                  *
 470                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 471                  */
 472                 if (seb->sqnum == sqnum && sqnum != 0) {
 473                         ubi_err("two LEBs with same sequence number %llu",
 474                                 sqnum);
 475                         ubi_dbg_dump_seb(seb, 0);
 476                         ubi_dbg_dump_vid_hdr(vid_hdr);
 477                         return -EINVAL;
 478                 }
 479
 480                 /*
 481                  * Now we have to drop the older one and preserve the newer
 482                  * one.
 483                  */
 484                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 485                 if (cmp_res < 0)
 486                         return cmp_res;
 487
 488                 if (cmp_res & 1) {
 489                         /*
 490                          * This logical eraseblock is newer then the one
 491                          * found earlier.
 492                          */
 493                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 494                         if (err)
 495                                 return err;
 496
 497                         if (cmp_res & 4)
 498                                 err = add_to_list(si, seb->pnum, seb->ec,
 499                                                   &si->corr);
 500                         else
 501                                 err = add_to_list(si, seb->pnum, seb->ec,
 502                                                   &si->erase);
 503                         if (err)
 504                                 return err;
 505
 506                         seb->ec = ec;
 507                         seb->pnum = pnum;
 508                         seb->scrub = ((cmp_res & 2) || bitflips);
 509                         seb->sqnum = sqnum;
 510                         seb->leb_ver = leb_ver;
 511
 512                         if (sv->highest_lnum == lnum)
 513                                 sv->last_data_size =
 514                                         be32_to_cpu(vid_hdr->data_size);
 515
 516                         return 0;
 517                 } else {
 518                         /*
 519                          * This logical eraseblock is older then the one found
 520                          * previously.
 521                          */
 522                         if (cmp_res & 4)
 523                                 return add_to_list(si, pnum, ec, &si->corr);
 524                         else
 525                                 return add_to_list(si, pnum, ec, &si->erase);
 526                 }
 527         }
 528
 529         /*
 530          * We've met this logical eraseblock for the first time, add it to the
 531          * scanning information.
 532          */
 533
 534         err = validate_vid_hdr(vid_hdr, sv, pnum);
 535         if (err)
 536                 return err;
 537
 538         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 539         if (!seb)
 540                 return -ENOMEM;
 541
 542         seb->ec = ec;
 543         seb->pnum = pnum;
 544         seb->lnum = lnum;
 545         seb->sqnum = sqnum;
 546         seb->scrub = bitflips;
 547         seb->leb_ver = leb_ver;
 548
 549         if (sv->highest_lnum <= lnum) {
 550                 sv->highest_lnum = lnum;
 551                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 552         }
 553
 554         sv->leb_count += 1;
 555         rb_link_node(&seb->u.rb, parent, p);
 556         rb_insert_color(&seb->u.rb, &sv->root);
 557         return 0;
 558 }
 559
 560 /**
 561  * ubi_scan_find_sv - find information about a particular volume in the
 562  * scanning information.
 563  * @si: scanning information
 564  * @vol_id: the requested volume ID
 565  *
 566  * This function returns a pointer to the volume description or %NULL if there
 567  * are no data about this volume in the scanning information.
 568  */
 569 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 570                                          int vol_id)
 571 {
 572         struct ubi_scan_volume *sv;
 573         struct rb_node *p = si->volumes.rb_node;
 574
 575         while (p) {
 576                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 577
 578                 if (vol_id == sv->vol_id)
 579                         return sv;
 580
 581                 if (vol_id > sv->vol_id)
 582                         p = p->rb_left;
 583                 else
 584                         p = p->rb_right;
 585         }
 586
 587         return NULL;
 588 }
 589
 590 /**
 591  * ubi_scan_find_seb - find information about a particular logical
 592  * eraseblock in the volume scanning information.
 593  * @sv: a pointer to the volume scanning information
 594  * @lnum: the requested logical eraseblock
 595  *
 596  * This function returns a pointer to the scanning logical eraseblock or %NULL
 597  * if there are no data about it in the scanning volume information.
 598  */
 599 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 600                                        int lnum)
 601 {
 602         struct ubi_scan_leb *seb;
 603         struct rb_node *p = sv->root.rb_node;
 604
 605         while (p) {
 606                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 607
 608                 if (lnum == seb->lnum)
 609                         return seb;
 610
 611                 if (lnum > seb->lnum)
 612                         p = p->rb_left;
 613                 else
 614                         p = p->rb_right;
 615         }
 616
 617         return NULL;
 618 }
 619
 620 /**
 621  * ubi_scan_rm_volume - delete scanning information about a volume.
 622  * @si: scanning information
 623  * @sv: the volume scanning information to delete
 624  */
 625 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 626 {
 627         struct rb_node *rb;
 628         struct ubi_scan_leb *seb;
 629
 630         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 631
 632         while ((rb = rb_first(&sv->root))) {
 633                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 634                 rb_erase(&seb->u.rb, &sv->root);
 635                 list_add_tail(&seb->u.list, &si->erase);
 636         }
 637
 638         rb_erase(&sv->rb, &si->volumes);
 639         kfree(sv);
 640         si->vols_found -= 1;
 641 }
 642
 643 /**
 644  * ubi_scan_erase_peb - erase a physical eraseblock.
 645  * @ubi: UBI device description object
 646  * @si: scanning information
 647  * @pnum: physical eraseblock number to erase;
 648  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 649  *
 650  * This function erases physical eraseblock 'pnum', and writes the erase
 651  * counter header to it. This function should only be used on UBI device
 652  * initialization stages, when the EBA unit had not been yet initialized. This
 653  * function returns zero in case of success and a negative error code in case
 654  * of failure.
 655  */
 656 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 657                        int pnum, int ec)
 658 {
 659         int err;
 660         struct ubi_ec_hdr *ec_hdr;
 661
 662         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 663                 /*
 664                  * Erase counter overflow. Upgrade UBI and use 64-bit
 665                  * erase counters internally.
 666                  */
 667                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 668                 return -EINVAL;
 669         }
 670
 671         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 672         if (!ec_hdr)
 673                 return -ENOMEM;
 674
 675         ec_hdr->ec = cpu_to_be64(ec);
 676
 677         err = ubi_io_sync_erase(ubi, pnum, 0);
 678         if (err < 0)
 679                 goto out_free;
 680
 681         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 682
 683 out_free:
 684         kfree(ec_hdr);
 685         return err;
 686 }
 687
 688 /**
 689  * ubi_scan_get_free_peb - get a free physical eraseblock.
 690  * @ubi: UBI device description object
 691  * @si: scanning information
 692  *
 693  * This function returns a free physical eraseblock. It is supposed to be
 694  * called on the UBI initialization stages when the wear-leveling unit is not
 695  * initialized yet. This function picks a physical eraseblocks from one of the
 696  * lists, writes the EC header if it is needed, and removes it from the list.
 697  *
 698  * This function returns scanning physical eraseblock information in case of
 699  * success and an error code in case of failure.
 700  */
 701 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 702                                            struct ubi_scan_info *si)
 703 {
 704         int err = 0, i;
 705         struct ubi_scan_leb *seb;
 706
 707         if (!list_empty(&si->free)) {
 708                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 709                 list_del(&seb->u.list);
 710                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 711                 return seb;
 712         }
 713
 714         for (i = 0; i < 2; i++) {
 715                 struct list_head *head;
 716                 struct ubi_scan_leb *tmp_seb;
 717
 718                 if (i == 0)
 719                         head = &si->erase;
 720                 else
 721                         head = &si->corr;
 722
 723                 /*
 724                  * We try to erase the first physical eraseblock from the @head
 725                  * list and pick it if we succeed, or try to erase the
 726                  * next one if not. And so forth. We don't want to take care
 727                  * about bad eraseblocks here - they'll be handled later.
 728                  */
 729                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 730                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 731                                 seb->ec = si->mean_ec;
 732
 733                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 734                         if (err)
 735                                 continue;
 736
 737                         seb->ec += 1;
 738                         list_del(&seb->u.list);
 739                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 740                         return seb;
 741                 }
 742         }
 743
 744         ubi_err("no eraseblocks found");
 745         return ERR_PTR(-ENOSPC);
 746 }
 747
 748 /**
 749  * process_eb - read UBI headers, check them and add corresponding data
 750  * to the scanning information.
 751  * @ubi: UBI device description object
 752  * @si: scanning information
 753  * @pnum: the physical eraseblock number
 754  *
 755  * This function returns a zero if the physical eraseblock was successfully
 756  * handled and a negative error code in case of failure.
 757  */
 758 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 759 {
 760         long long uninitialized_var(ec);
 761         int err, bitflips = 0, vol_id, ec_corr = 0;
 762
 763         dbg_bld("scan PEB %d", pnum);
 764
 765         /* Skip bad physical eraseblocks */
 766         err = ubi_io_is_bad(ubi, pnum);
 767         if (err < 0)
 768                 return err;
 769         else if (err) {
 770                 /*
 771                  * FIXME: this is actually duty of the I/O unit to initialize
 772                  * this, but MTD does not provide enough information.
 773                  */
 774                 si->bad_peb_count += 1;
 775                 return 0;
 776         }
 777
 778         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 779         if (err < 0)
 780                 return err;
 781         else if (err == UBI_IO_BITFLIPS)
 782                 bitflips = 1;
 783         else if (err == UBI_IO_PEB_EMPTY)
 784                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 785         else if (err == UBI_IO_BAD_EC_HDR) {
 786                 /*
 787                  * We have to also look at the VID header, possibly it is not
 788                  * corrupted. Set %bitflips flag in order to make this PEB be
 789                  * moved and EC be re-created.
 790                  */
 791                 ec_corr = 1;
 792                 ec = UBI_SCAN_UNKNOWN_EC;
 793                 bitflips = 1;
 794         }
 795
 796         si->is_empty = 0;
 797
 798         if (!ec_corr) {
 799                 /* Make sure UBI version is OK */
 800                 if (ech->version != UBI_VERSION) {
 801                         ubi_err("this UBI version is %d, image version is %d",
 802                                 UBI_VERSION, (int)ech->version);
 803                         return -EINVAL;
 804                 }
 805
 806                 ec = be64_to_cpu(ech->ec);
 807                 if (ec > UBI_MAX_ERASECOUNTER) {
 808                         /*
 809                          * Erase counter overflow. The EC headers have 64 bits
 810                          * reserved, but we anyway make use of only 31 bit
 811                          * values, as this seems to be enough for any existing
 812                          * flash. Upgrade UBI and use 64-bit erase counters
 813                          * internally.
 814                          */
 815                         ubi_err("erase counter overflow, max is %d",
 816                                 UBI_MAX_ERASECOUNTER);
 817                         ubi_dbg_dump_ec_hdr(ech);
 818                         return -EINVAL;
 819                 }
 820         }
 821
 822         /* OK, we've done with the EC header, let's look at the VID header */
 823
 824         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 825         if (err < 0)
 826                 return err;
 827         else if (err == UBI_IO_BITFLIPS)
 828                 bitflips = 1;
 829         else if (err == UBI_IO_BAD_VID_HDR ||
 830                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 831                 /* VID header is corrupted */
 832                 err = add_to_list(si, pnum, ec, &si->corr);
 833                 if (err)
 834                         return err;
 835                 goto adjust_mean_ec;
 836         } else if (err == UBI_IO_PEB_FREE) {
 837                 /* No VID header - the physical eraseblock is free */
 838                 err = add_to_list(si, pnum, ec, &si->free);
 839                 if (err)
 840                         return err;
 841                 goto adjust_mean_ec;
 842         }
 843
 844         vol_id = be32_to_cpu(vidh->vol_id);
 845         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 846                 int lnum = be32_to_cpu(vidh->lnum);
 847
 848                 /* Unsupported internal volume */
 849                 switch (vidh->compat) {
 850                 case UBI_COMPAT_DELETE:
 851                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 852                                 " found, remove it", vol_id, lnum);
 853                         err = add_to_list(si, pnum, ec, &si->corr);
 854                         if (err)
 855                                 return err;
 856                         break;
 857
 858                 case UBI_COMPAT_RO:
 859                         ubi_msg("read-only compatible internal volume %d:%d"
 860                                 " found, switch to read-only mode",
 861                                 vol_id, lnum);
 862                         ubi->ro_mode = 1;
 863                         break;
 864
 865                 case UBI_COMPAT_PRESERVE:
 866                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 867                                 " found", vol_id, lnum);
 868                         err = add_to_list(si, pnum, ec, &si->alien);
 869                         if (err)
 870                                 return err;
 871                         si->alien_peb_count += 1;
 872                         return 0;
 873
 874                 case UBI_COMPAT_REJECT:
 875                         ubi_err("incompatible internal volume %d:%d found",
 876                                 vol_id, lnum);
 877                         return -EINVAL;
 878                 }
 879         }
 880
 881         /* Both UBI headers seem to be fine */
 882         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 883         if (err)
 884                 return err;
 885
 886 adjust_mean_ec:
 887         if (!ec_corr) {
 888                 si->ec_sum += ec;
 889                 si->ec_count += 1;
 890                 if (ec > si->max_ec)
 891                         si->max_ec = ec;
 892                 if (ec < si->min_ec)
 893                         si->min_ec = ec;
 894         }
 895
 896         return 0;
 897 }
 898
 899 /**
 900  * ubi_scan - scan an MTD device.
 901  * @ubi: UBI device description object
 902  *
 903  * This function does full scanning of an MTD device and returns complete
 904  * information about it. In case of failure, an error code is returned.
 905  */
 906 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 907 {
 908         int err, pnum;
 909         struct rb_node *rb1, *rb2;
 910         struct ubi_scan_volume *sv;
 911         struct ubi_scan_leb *seb;
 912         struct ubi_scan_info *si;
 913
 914         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 915         if (!si)
 916                 return ERR_PTR(-ENOMEM);
 917
 918         INIT_LIST_HEAD(&si->corr);
 919         INIT_LIST_HEAD(&si->free);
 920         INIT_LIST_HEAD(&si->erase);
 921         INIT_LIST_HEAD(&si->alien);
 922         si->volumes = RB_ROOT;
 923         si->is_empty = 1;
 924
 925         err = -ENOMEM;
 926         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 927         if (!ech)
 928                 goto out_si;
 929
 930         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 931         if (!vidh)
 932                 goto out_ech;
 933
 934         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 935                 cond_resched();
 936
 937                 dbg_msg("process PEB %d", pnum);
 938                 err = process_eb(ubi, si, pnum);
 939                 if (err < 0)
 940                         goto out_vidh;
 941         }
 942
 943         dbg_msg("scanning is finished");
 944
 945         /* Calculate mean erase counter */
 946         if (si->ec_count) {
 947                 do_div(si->ec_sum, si->ec_count);
 948                 si->mean_ec = si->ec_sum;
 949         }
 950
 951         if (si->is_empty)
 952                 ubi_msg("empty MTD device detected");
 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                 if (err > 0)
 980                         err = -EINVAL;
 981                 goto out_vidh;
 982         }
 983
 984         ubi_free_vid_hdr(ubi, vidh);
 985         kfree(ech);
 986
 987         return si;
 988
 989 out_vidh:
 990         ubi_free_vid_hdr(ubi, vidh);
 991 out_ech:
 992         kfree(ech);
 993 out_si:
 994         ubi_scan_destroy_si(si);
 995         return ERR_PTR(err);
 996 }
 997
 998 /**
 999  * destroy_sv - free the scanning volume information
1000  * @sv: scanning volume information
1001  *
1002  * This function destroys the volume RB-tree (@sv->root) and the scanning
1003  * volume information.
1004  */
1005 static void destroy_sv(struct ubi_scan_volume *sv)
1006 {
1007         struct ubi_scan_leb *seb;
1008         struct rb_node *this = sv->root.rb_node;
1009
1010         while (this) {
1011                 if (this->rb_left)
1012                         this = this->rb_left;
1013                 else if (this->rb_right)
1014                         this = this->rb_right;
1015                 else {
1016                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1017                         this = rb_parent(this);
1018                         if (this) {
1019                                 if (this->rb_left == &seb->u.rb)
1020                                         this->rb_left = NULL;
1021                                 else
1022                                         this->rb_right = NULL;
1023                         }
1024
1025                         kfree(seb);
1026                 }
1027         }
1028         kfree(sv);
1029 }
1030
1031 /**
1032  * ubi_scan_destroy_si - destroy scanning information.
1033  * @si: scanning information
1034  */
1035 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1036 {
1037         struct ubi_scan_leb *seb, *seb_tmp;
1038         struct ubi_scan_volume *sv;
1039         struct rb_node *rb;
1040
1041         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1042                 list_del(&seb->u.list);
1043                 kfree(seb);
1044         }
1045         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1046                 list_del(&seb->u.list);
1047                 kfree(seb);
1048         }
1049         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1050                 list_del(&seb->u.list);
1051                 kfree(seb);
1052         }
1053         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1054                 list_del(&seb->u.list);
1055                 kfree(seb);
1056         }
1057
1058         /* Destroy the volume RB-tree */
1059         rb = si->volumes.rb_node;
1060         while (rb) {
1061                 if (rb->rb_left)
1062                         rb = rb->rb_left;
1063                 else if (rb->rb_right)
1064                         rb = rb->rb_right;
1065                 else {
1066                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1067
1068                         rb = rb_parent(rb);
1069                         if (rb) {
1070                                 if (rb->rb_left == &sv->rb)
1071                                         rb->rb_left = NULL;
1072                                 else
1073                                         rb->rb_right = NULL;
1074                         }
1075
1076                         destroy_sv(sv);
1077                 }
1078         }
1079
1080         kfree(si);
1081 }
1082
1083 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1084
1085 /**
1086  * paranoid_check_si - check if the scanning information is correct and
1087  * consistent.
1088  * @ubi: UBI device description object
1089  * @si: scanning information
1090  *
1091  * This function returns zero if the scanning information is all right, %1 if
1092  * not and a negative error code if an error occurred.
1093  */
1094 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1095 {
1096         int pnum, err, vols_found = 0;
1097         struct rb_node *rb1, *rb2;
1098         struct ubi_scan_volume *sv;
1099         struct ubi_scan_leb *seb, *last_seb;
1100         uint8_t *buf;
1101
1102         /*
1103          * At first, check that scanning information is OK.
1104          */
1105         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1106                 int leb_count = 0;
1107
1108                 cond_resched();
1109
1110                 vols_found += 1;
1111
1112                 if (si->is_empty) {
1113                         ubi_err("bad is_empty flag");
1114                         goto bad_sv;
1115                 }
1116
1117                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1118                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1119                     sv->data_pad < 0 || sv->last_data_size < 0) {
1120                         ubi_err("negative values");
1121                         goto bad_sv;
1122                 }
1123
1124                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1125                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1126                         ubi_err("bad vol_id");
1127                         goto bad_sv;
1128                 }
1129
1130                 if (sv->vol_id > si->highest_vol_id) {
1131                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1132                                 si->highest_vol_id, sv->vol_id);
1133                         goto out;
1134                 }
1135
1136                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1137                     sv->vol_type != UBI_STATIC_VOLUME) {
1138                         ubi_err("bad vol_type");
1139                         goto bad_sv;
1140                 }
1141
1142                 if (sv->data_pad > ubi->leb_size / 2) {
1143                         ubi_err("bad data_pad");
1144                         goto bad_sv;
1145                 }
1146
1147                 last_seb = NULL;
1148                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1149                         cond_resched();
1150
1151                         last_seb = seb;
1152                         leb_count += 1;
1153
1154                         if (seb->pnum < 0 || seb->ec < 0) {
1155                                 ubi_err("negative values");
1156                                 goto bad_seb;
1157                         }
1158
1159                         if (seb->ec < si->min_ec) {
1160                                 ubi_err("bad si->min_ec (%d), %d found",
1161                                         si->min_ec, seb->ec);
1162                                 goto bad_seb;
1163                         }
1164
1165                         if (seb->ec > si->max_ec) {
1166                                 ubi_err("bad si->max_ec (%d), %d found",
1167                                         si->max_ec, seb->ec);
1168                                 goto bad_seb;
1169                         }
1170
1171                         if (seb->pnum >= ubi->peb_count) {
1172                                 ubi_err("too high PEB number %d, total PEBs %d",
1173                                         seb->pnum, ubi->peb_count);
1174                                 goto bad_seb;
1175                         }
1176
1177                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1178                                 if (seb->lnum >= sv->used_ebs) {
1179                                         ubi_err("bad lnum or used_ebs");
1180                                         goto bad_seb;
1181                                 }
1182                         } else {
1183                                 if (sv->used_ebs != 0) {
1184                                         ubi_err("non-zero used_ebs");
1185                                         goto bad_seb;
1186                                 }
1187                         }
1188
1189                         if (seb->lnum > sv->highest_lnum) {
1190                                 ubi_err("incorrect highest_lnum or lnum");
1191                                 goto bad_seb;
1192                         }
1193                 }
1194
1195                 if (sv->leb_count != leb_count) {
1196                         ubi_err("bad leb_count, %d objects in the tree",
1197                                 leb_count);
1198                         goto bad_sv;
1199                 }
1200
1201                 if (!last_seb)
1202                         continue;
1203
1204                 seb = last_seb;
1205
1206                 if (seb->lnum != sv->highest_lnum) {
1207                         ubi_err("bad highest_lnum");
1208                         goto bad_seb;
1209                 }
1210         }
1211
1212         if (vols_found != si->vols_found) {
1213                 ubi_err("bad si->vols_found %d, should be %d",
1214                         si->vols_found, vols_found);
1215                 goto out;
1216         }
1217
1218         /* Check that scanning information is correct */
1219         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1220                 last_seb = NULL;
1221                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1222                         int vol_type;
1223
1224                         cond_resched();
1225
1226                         last_seb = seb;
1227
1228                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1229                         if (err && err != UBI_IO_BITFLIPS) {
1230                                 ubi_err("VID header is not OK (%d)", err);
1231                                 if (err > 0)
1232                                         err = -EIO;
1233                                 return err;
1234                         }
1235
1236                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1237                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1238                         if (sv->vol_type != vol_type) {
1239                                 ubi_err("bad vol_type");
1240                                 goto bad_vid_hdr;
1241                         }
1242
1243                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1244                                 ubi_err("bad sqnum %llu", seb->sqnum);
1245                                 goto bad_vid_hdr;
1246                         }
1247
1248                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1249                                 ubi_err("bad vol_id %d", sv->vol_id);
1250                                 goto bad_vid_hdr;
1251                         }
1252
1253                         if (sv->compat != vidh->compat) {
1254                                 ubi_err("bad compat %d", vidh->compat);
1255                                 goto bad_vid_hdr;
1256                         }
1257
1258                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1259                                 ubi_err("bad lnum %d", seb->lnum);
1260                                 goto bad_vid_hdr;
1261                         }
1262
1263                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1264                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1265                                 goto bad_vid_hdr;
1266                         }
1267
1268                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1269                                 ubi_err("bad data_pad %d", sv->data_pad);
1270                                 goto bad_vid_hdr;
1271                         }
1272
1273                         if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
1274                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1275                                 goto bad_vid_hdr;
1276                         }
1277                 }
1278
1279                 if (!last_seb)
1280                         continue;
1281
1282                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1283                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1284                         goto bad_vid_hdr;
1285                 }
1286
1287                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1288                         ubi_err("bad last_data_size %d", sv->last_data_size);
1289                         goto bad_vid_hdr;
1290                 }
1291         }
1292
1293         /*
1294          * Make sure that all the physical eraseblocks are in one of the lists
1295          * or trees.
1296          */
1297         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1298         if (!buf)
1299                 return -ENOMEM;
1300
1301         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1302                 err = ubi_io_is_bad(ubi, pnum);
1303                 if (err < 0) {
1304                         kfree(buf);
1305                         return err;
1306                 }
1307                 else if (err)
1308                         buf[pnum] = 1;
1309         }
1310
1311         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1312                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1313                         buf[seb->pnum] = 1;
1314
1315         list_for_each_entry(seb, &si->free, u.list)
1316                 buf[seb->pnum] = 1;
1317
1318         list_for_each_entry(seb, &si->corr, u.list)
1319                 buf[seb->pnum] = 1;
1320
1321         list_for_each_entry(seb, &si->erase, u.list)
1322                 buf[seb->pnum] = 1;
1323
1324         list_for_each_entry(seb, &si->alien, u.list)
1325                 buf[seb->pnum] = 1;
1326
1327         err = 0;
1328         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1329                 if (!buf[pnum]) {
1330                         ubi_err("PEB %d is not referred", pnum);
1331                         err = 1;
1332                 }
1333
1334         kfree(buf);
1335         if (err)
1336                 goto out;
1337         return 0;
1338
1339 bad_seb:
1340         ubi_err("bad scanning information about LEB %d", seb->lnum);
1341         ubi_dbg_dump_seb(seb, 0);
1342         ubi_dbg_dump_sv(sv);
1343         goto out;
1344
1345 bad_sv:
1346         ubi_err("bad scanning information about volume %d", sv->vol_id);
1347         ubi_dbg_dump_sv(sv);
1348         goto out;
1349
1350 bad_vid_hdr:
1351         ubi_err("bad scanning information about volume %d", sv->vol_id);
1352         ubi_dbg_dump_sv(sv);
1353         ubi_dbg_dump_vid_hdr(vidh);
1354
1355 out:
1356         ubi_dbg_dump_stack();
1357         return 1;
1358 }
1359
1360 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */