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 "ubi.h"
  46
  47 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  48 static int paranoid_check_si(const struct ubi_device *ubi,
  49                              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  * commit_to_mean_value - commit intermediate results to the final mean erase
  97  * counter value.
  98  * @si: scanning information
  99  *
 100  * This is a helper function which calculates partial mean erase counter mean
 101  * value and adds it to the resulting mean value. As we can work only in
 102  * integer arithmetic and we want to calculate the mean value of erase counter
 103  * accurately, we first sum erase counter values in @si->ec_sum variable and
 104  * count these components in @si->ec_count. If this temporary @si->ec_sum is
 105  * going to overflow, we calculate the partial mean value
 106  * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
 107  */
 108 static void commit_to_mean_value(struct ubi_scan_info *si)
 109 {
 110         si->ec_sum /= si->ec_count;
 111         if (si->ec_sum % si->ec_count >= si->ec_count / 2)
 112                 si->mean_ec += 1;
 113         si->mean_ec += si->ec_sum;
 114 }
 115
 116 /**
 117  * validate_vid_hdr - check that volume identifier header is correct and
 118  * consistent.
 119  * @vid_hdr: the volume identifier header to check
 120  * @sv: information about the volume this logical eraseblock belongs to
 121  * @pnum: physical eraseblock number the VID header came from
 122  *
 123  * This function checks that data stored in @vid_hdr is consistent. Returns
 124  * non-zero if an inconsistency was found and zero if not.
 125  *
 126  * Note, UBI does sanity check of everything it reads from the flash media.
 127  * Most of the checks are done in the I/O unit. Here we check that the
 128  * information in the VID header is consistent to the information in other VID
 129  * headers of the same volume.
 130  */
 131 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 132                             const struct ubi_scan_volume *sv, int pnum)
 133 {
 134         int vol_type = vid_hdr->vol_type;
 135         int vol_id = ubi32_to_cpu(vid_hdr->vol_id);
 136         int used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 137         int data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 138
 139         if (sv->leb_count != 0) {
 140                 int sv_vol_type;
 141
 142                 /*
 143                  * This is not the first logical eraseblock belonging to this
 144                  * volume. Ensure that the data in its VID header is consistent
 145                  * to the data in previous logical eraseblock headers.
 146                  */
 147
 148                 if (vol_id != sv->vol_id) {
 149                         dbg_err("inconsistent vol_id");
 150                         goto bad;
 151                 }
 152
 153                 if (sv->vol_type == UBI_STATIC_VOLUME)
 154                         sv_vol_type = UBI_VID_STATIC;
 155                 else
 156                         sv_vol_type = UBI_VID_DYNAMIC;
 157
 158                 if (vol_type != sv_vol_type) {
 159                         dbg_err("inconsistent vol_type");
 160                         goto bad;
 161                 }
 162
 163                 if (used_ebs != sv->used_ebs) {
 164                         dbg_err("inconsistent used_ebs");
 165                         goto bad;
 166                 }
 167
 168                 if (data_pad != sv->data_pad) {
 169                         dbg_err("inconsistent data_pad");
 170                         goto bad;
 171                 }
 172         }
 173
 174         return 0;
 175
 176 bad:
 177         ubi_err("inconsistent VID header at PEB %d", pnum);
 178         ubi_dbg_dump_vid_hdr(vid_hdr);
 179         ubi_dbg_dump_sv(sv);
 180         return -EINVAL;
 181 }
 182
 183 /**
 184  * add_volume - add volume to the scanning information.
 185  * @si: scanning information
 186  * @vol_id: ID of the volume to add
 187  * @pnum: physical eraseblock number
 188  * @vid_hdr: volume identifier header
 189  *
 190  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 191  * present in the scanning information, this function does nothing. Otherwise
 192  * it adds corresponding volume to the scanning information. Returns a pointer
 193  * to the scanning volume object in case of success and a negative error code
 194  * in case of failure.
 195  */
 196 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 197                                           int pnum,
 198                                           const struct ubi_vid_hdr *vid_hdr)
 199 {
 200         struct ubi_scan_volume *sv;
 201         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 202
 203         ubi_assert(vol_id == ubi32_to_cpu(vid_hdr->vol_id));
 204
 205         /* Walk the volume RB-tree to look if this volume is already present */
 206         while (*p) {
 207                 parent = *p;
 208                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 209
 210                 if (vol_id == sv->vol_id)
 211                         return sv;
 212
 213                 if (vol_id > sv->vol_id)
 214                         p = &(*p)->rb_left;
 215                 else
 216                         p = &(*p)->rb_right;
 217         }
 218
 219         /* The volume is absent - add it */
 220         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 221         if (!sv)
 222                 return ERR_PTR(-ENOMEM);
 223
 224         sv->highest_lnum = sv->leb_count = 0;
 225         si->max_sqnum = 0;
 226         sv->vol_id = vol_id;
 227         sv->root = RB_ROOT;
 228         sv->used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 229         sv->data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 230         sv->compat = vid_hdr->compat;
 231         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 232                                                             : UBI_STATIC_VOLUME;
 233         if (vol_id > si->highest_vol_id)
 234                 si->highest_vol_id = vol_id;
 235
 236         rb_link_node(&sv->rb, parent, p);
 237         rb_insert_color(&sv->rb, &si->volumes);
 238         si->vols_found += 1;
 239         dbg_bld("added volume %d", vol_id);
 240         return sv;
 241 }
 242
 243 /**
 244  * compare_lebs - find out which logical eraseblock is newer.
 245  * @ubi: UBI device description object
 246  * @seb: first logical eraseblock to compare
 247  * @pnum: physical eraseblock number of the second logical eraseblock to
 248  * compare
 249  * @vid_hdr: volume identifier header of the second logical eraseblock
 250  *
 251  * This function compares 2 copies of a LEB and informs which one is newer. In
 252  * case of success this function returns a positive value, in case of failure, a
 253  * negative error code is returned. The success return codes use the following
 254  * bits:
 255  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 256  *       second PEB (described by @pnum and @vid_hdr);
 257  *     o bit 0 is set: the second PEB is newer;
 258  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 259  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 260  *     o bit 2 is cleared: the older LEB is not corrupted;
 261  *     o bit 2 is set: the older LEB is corrupted.
 262  */
 263 static int compare_lebs(const struct ubi_device *ubi,
 264                         const struct ubi_scan_leb *seb, int pnum,
 265                         const struct ubi_vid_hdr *vid_hdr)
 266 {
 267         void *buf;
 268         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 269         uint32_t data_crc, crc;
 270         struct ubi_vid_hdr *vidh = NULL;
 271         unsigned long long sqnum2 = ubi64_to_cpu(vid_hdr->sqnum);
 272
 273         if (seb->sqnum == 0 && sqnum2 == 0) {
 274                 long long abs, v1 = seb->leb_ver, v2 = ubi32_to_cpu(vid_hdr->leb_ver);
 275
 276                 /*
 277                  * UBI constantly increases the logical eraseblock version
 278                  * number and it can overflow. Thus, we have to bear in mind
 279                  * that versions that are close to %0xFFFFFFFF are less then
 280                  * versions that are close to %0.
 281                  *
 282                  * The UBI WL unit guarantees that the number of pending tasks
 283                  * is not greater then %0x7FFFFFFF. So, if the difference
 284                  * between any two versions is greater or equivalent to
 285                  * %0x7FFFFFFF, there was an overflow and the logical
 286                  * eraseblock with lower version is actually newer then the one
 287                  * with higher version.
 288                  *
 289                  * FIXME: but this is anyway obsolete and will be removed at
 290                  * some point.
 291                  */
 292
 293                 dbg_bld("using old crappy leb_ver stuff");
 294
 295                 abs = v1 - v2;
 296                 if (abs < 0)
 297                         abs = -abs;
 298
 299                 if (abs < 0x7FFFFFFF)
 300                         /* Non-overflow situation */
 301                         second_is_newer = (v2 > v1);
 302                 else
 303                         second_is_newer = (v2 < v1);
 304         } else
 305                 /* Obviously the LEB with lower sequence counter is older */
 306                 second_is_newer = sqnum2 > seb->sqnum;
 307
 308         /*
 309          * Now we know which copy is newer. If the copy flag of the PEB with
 310          * newer version is not set, then we just return, otherwise we have to
 311          * check data CRC. For the second PEB we already have the VID header,
 312          * for the first one - we'll need to re-read it from flash.
 313          *
 314          * FIXME: this may be optimized so that we wouldn't read twice.
 315          */
 316
 317         if (second_is_newer) {
 318                 if (!vid_hdr->copy_flag) {
 319                         /* It is not a copy, so it is newer */
 320                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 321                                 pnum);
 322                         return 1;
 323                 }
 324         } else {
 325                 pnum = seb->pnum;
 326
 327                 vidh = ubi_zalloc_vid_hdr(ubi);
 328                 if (!vidh)
 329                         return -ENOMEM;
 330
 331                 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 332                 if (err) {
 333                         if (err == UBI_IO_BITFLIPS)
 334                                 bitflips = 1;
 335                         else {
 336                                 dbg_err("VID of PEB %d header is bad, but it "
 337                                         "was OK earlier", pnum);
 338                                 if (err > 0)
 339                                         err = -EIO;
 340
 341                                 goto out_free_vidh;
 342                         }
 343                 }
 344
 345                 if (!vidh->copy_flag) {
 346                         /* It is not a copy, so it is newer */
 347                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 348                                 pnum);
 349                         err = bitflips << 1;
 350                         goto out_free_vidh;
 351                 }
 352
 353                 vid_hdr = vidh;
 354         }
 355
 356         /* Read the data of the copy and check the CRC */
 357
 358         len = ubi32_to_cpu(vid_hdr->data_size);
 359         buf = kmalloc(len, GFP_KERNEL);
 360         if (!buf) {
 361                 err = -ENOMEM;
 362                 goto out_free_vidh;
 363         }
 364
 365         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 366         if (err && err != UBI_IO_BITFLIPS)
 367                 goto out_free_buf;
 368
 369         data_crc = ubi32_to_cpu(vid_hdr->data_crc);
 370         crc = crc32(UBI_CRC32_INIT, buf, len);
 371         if (crc != data_crc) {
 372                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 373                         pnum, crc, data_crc);
 374                 corrupted = 1;
 375                 bitflips = 0;
 376                 second_is_newer = !second_is_newer;
 377         } else {
 378                 dbg_bld("PEB %d CRC is OK", pnum);
 379                 bitflips = !!err;
 380         }
 381
 382         kfree(buf);
 383         ubi_free_vid_hdr(ubi, vidh);
 384
 385         if (second_is_newer)
 386                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 387         else
 388                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 389
 390         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 391
 392 out_free_buf:
 393         kfree(buf);
 394 out_free_vidh:
 395         ubi_free_vid_hdr(ubi, vidh);
 396         ubi_assert(err < 0);
 397         return err;
 398 }
 399
 400 /**
 401  * ubi_scan_add_used - add information about a physical eraseblock to the
 402  * scanning information.
 403  * @ubi: UBI device description object
 404  * @si: scanning information
 405  * @pnum: the physical eraseblock number
 406  * @ec: erase counter
 407  * @vid_hdr: the volume identifier header
 408  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 409  *
 410  * This function returns zero in case of success and a negative error code in
 411  * case of failure.
 412  */
 413 int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si,
 414                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 415                       int bitflips)
 416 {
 417         int err, vol_id, lnum;
 418         uint32_t leb_ver;
 419         unsigned long long sqnum;
 420         struct ubi_scan_volume *sv;
 421         struct ubi_scan_leb *seb;
 422         struct rb_node **p, *parent = NULL;
 423
 424         vol_id = ubi32_to_cpu(vid_hdr->vol_id);
 425         lnum = ubi32_to_cpu(vid_hdr->lnum);
 426         sqnum = ubi64_to_cpu(vid_hdr->sqnum);
 427         leb_ver = ubi32_to_cpu(vid_hdr->leb_ver);
 428
 429         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 430                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 431
 432         sv = add_volume(si, vol_id, pnum, vid_hdr);
 433         if (IS_ERR(sv) < 0)
 434                 return PTR_ERR(sv);
 435
 436         /*
 437          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 438          * if this is the first instance of this logical eraseblock or not.
 439          */
 440         p = &sv->root.rb_node;
 441         while (*p) {
 442                 int cmp_res;
 443
 444                 parent = *p;
 445                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 446                 if (lnum != seb->lnum) {
 447                         if (lnum < seb->lnum)
 448                                 p = &(*p)->rb_left;
 449                         else
 450                                 p = &(*p)->rb_right;
 451                         continue;
 452                 }
 453
 454                 /*
 455                  * There is already a physical eraseblock describing the same
 456                  * logical eraseblock present.
 457                  */
 458
 459                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 460                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 461                         seb->leb_ver, seb->ec);
 462
 463                 /*
 464                  * Make sure that the logical eraseblocks have different
 465                  * versions. Otherwise the image is bad.
 466                  */
 467                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 468                         ubi_err("two LEBs with same version %u", leb_ver);
 469                         ubi_dbg_dump_seb(seb, 0);
 470                         ubi_dbg_dump_vid_hdr(vid_hdr);
 471                         return -EINVAL;
 472                 }
 473
 474                 /*
 475                  * Make sure that the logical eraseblocks have different
 476                  * sequence numbers. Otherwise the image is bad.
 477                  *
 478                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 479                  */
 480                 if (seb->sqnum == sqnum && sqnum != 0) {
 481                         ubi_err("two LEBs with same sequence number %llu",
 482                                 sqnum);
 483                         ubi_dbg_dump_seb(seb, 0);
 484                         ubi_dbg_dump_vid_hdr(vid_hdr);
 485                         return -EINVAL;
 486                 }
 487
 488                 /*
 489                  * Now we have to drop the older one and preserve the newer
 490                  * one.
 491                  */
 492                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 493                 if (cmp_res < 0)
 494                         return cmp_res;
 495
 496                 if (cmp_res & 1) {
 497                         /*
 498                          * This logical eraseblock is newer then the one
 499                          * found earlier.
 500                          */
 501                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 502                         if (err)
 503                                 return err;
 504
 505                         if (cmp_res & 4)
 506                                 err = add_to_list(si, seb->pnum, seb->ec,
 507                                                   &si->corr);
 508                         else
 509                                 err = add_to_list(si, seb->pnum, seb->ec,
 510                                                   &si->erase);
 511                         if (err)
 512                                 return err;
 513
 514                         seb->ec = ec;
 515                         seb->pnum = pnum;
 516                         seb->scrub = ((cmp_res & 2) || bitflips);
 517                         seb->sqnum = sqnum;
 518                         seb->leb_ver = leb_ver;
 519
 520                         if (sv->highest_lnum == lnum)
 521                                 sv->last_data_size =
 522                                         ubi32_to_cpu(vid_hdr->data_size);
 523
 524                         return 0;
 525                 } else {
 526                         /*
 527                          * This logical eraseblock is older then the one found
 528                          * previously.
 529                          */
 530                         if (cmp_res & 4)
 531                                 return add_to_list(si, pnum, ec, &si->corr);
 532                         else
 533                                 return add_to_list(si, pnum, ec, &si->erase);
 534                 }
 535         }
 536
 537         /*
 538          * We've met this logical eraseblock for the first time, add it to the
 539          * scanning information.
 540          */
 541
 542         err = validate_vid_hdr(vid_hdr, sv, pnum);
 543         if (err)
 544                 return err;
 545
 546         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 547         if (!seb)
 548                 return -ENOMEM;
 549
 550         seb->ec = ec;
 551         seb->pnum = pnum;
 552         seb->lnum = lnum;
 553         seb->sqnum = sqnum;
 554         seb->scrub = bitflips;
 555         seb->leb_ver = leb_ver;
 556
 557         if (sv->highest_lnum <= lnum) {
 558                 sv->highest_lnum = lnum;
 559                 sv->last_data_size = ubi32_to_cpu(vid_hdr->data_size);
 560         }
 561
 562         if (si->max_sqnum < sqnum)
 563                 si->max_sqnum = sqnum;
 564
 565         sv->leb_count += 1;
 566         rb_link_node(&seb->u.rb, parent, p);
 567         rb_insert_color(&seb->u.rb, &sv->root);
 568         return 0;
 569 }
 570
 571 /**
 572  * ubi_scan_find_sv - find information about a particular volume in the
 573  * scanning information.
 574  * @si: scanning information
 575  * @vol_id: the requested volume ID
 576  *
 577  * This function returns a pointer to the volume description or %NULL if there
 578  * are no data about this volume in the scanning information.
 579  */
 580 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 581                                          int vol_id)
 582 {
 583         struct ubi_scan_volume *sv;
 584         struct rb_node *p = si->volumes.rb_node;
 585
 586         while (p) {
 587                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 588
 589                 if (vol_id == sv->vol_id)
 590                         return sv;
 591
 592                 if (vol_id > sv->vol_id)
 593                         p = p->rb_left;
 594                 else
 595                         p = p->rb_right;
 596         }
 597
 598         return NULL;
 599 }
 600
 601 /**
 602  * ubi_scan_find_seb - find information about a particular logical
 603  * eraseblock in the volume scanning information.
 604  * @sv: a pointer to the volume scanning information
 605  * @lnum: the requested logical eraseblock
 606  *
 607  * This function returns a pointer to the scanning logical eraseblock or %NULL
 608  * if there are no data about it in the scanning volume information.
 609  */
 610 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 611                                        int lnum)
 612 {
 613         struct ubi_scan_leb *seb;
 614         struct rb_node *p = sv->root.rb_node;
 615
 616         while (p) {
 617                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 618
 619                 if (lnum == seb->lnum)
 620                         return seb;
 621
 622                 if (lnum > seb->lnum)
 623                         p = p->rb_left;
 624                 else
 625                         p = p->rb_right;
 626         }
 627
 628         return NULL;
 629 }
 630
 631 /**
 632  * ubi_scan_rm_volume - delete scanning information about a volume.
 633  * @si: scanning information
 634  * @sv: the volume scanning information to delete
 635  */
 636 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 637 {
 638         struct rb_node *rb;
 639         struct ubi_scan_leb *seb;
 640
 641         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 642
 643         while ((rb = rb_first(&sv->root))) {
 644                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 645                 rb_erase(&seb->u.rb, &sv->root);
 646                 list_add_tail(&seb->u.list, &si->erase);
 647         }
 648
 649         rb_erase(&sv->rb, &si->volumes);
 650         kfree(sv);
 651         si->vols_found -= 1;
 652 }
 653
 654 /**
 655  * ubi_scan_erase_peb - erase a physical eraseblock.
 656  * @ubi: UBI device description object
 657  * @si: scanning information
 658  * @pnum: physical eraseblock number to erase;
 659  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 660  *
 661  * This function erases physical eraseblock 'pnum', and writes the erase
 662  * counter header to it. This function should only be used on UBI device
 663  * initialization stages, when the EBA unit had not been yet initialized. This
 664  * function returns zero in case of success and a negative error code in case
 665  * of failure.
 666  */
 667 int ubi_scan_erase_peb(const struct ubi_device *ubi,
 668                        const struct ubi_scan_info *si, int pnum, int ec)
 669 {
 670         int err;
 671         struct ubi_ec_hdr *ec_hdr;
 672
 673         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 674         if (!ec_hdr)
 675                 return -ENOMEM;
 676
 677         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 678                 /*
 679                  * Erase counter overflow. Upgrade UBI and use 64-bit
 680                  * erase counters internally.
 681                  */
 682                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 683                 return -EINVAL;
 684         }
 685
 686         ec_hdr->ec = cpu_to_ubi64(ec);
 687
 688         err = ubi_io_sync_erase(ubi, pnum, 0);
 689         if (err < 0)
 690                 goto out_free;
 691
 692         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 693
 694 out_free:
 695         kfree(ec_hdr);
 696         return err;
 697 }
 698
 699 /**
 700  * ubi_scan_get_free_peb - get a free physical eraseblock.
 701  * @ubi: UBI device description object
 702  * @si: scanning information
 703  *
 704  * This function returns a free physical eraseblock. It is supposed to be
 705  * called on the UBI initialization stages when the wear-leveling unit is not
 706  * initialized yet. This function picks a physical eraseblocks from one of the
 707  * lists, writes the EC header if it is needed, and removes it from the list.
 708  *
 709  * This function returns scanning physical eraseblock information in case of
 710  * success and an error code in case of failure.
 711  */
 712 struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
 713                                            struct ubi_scan_info *si)
 714 {
 715         int err = 0, i;
 716         struct ubi_scan_leb *seb;
 717
 718         if (!list_empty(&si->free)) {
 719                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 720                 list_del(&seb->u.list);
 721                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 722                 return seb;
 723         }
 724
 725         for (i = 0; i < 2; i++) {
 726                 struct list_head *head;
 727                 struct ubi_scan_leb *tmp_seb;
 728
 729                 if (i == 0)
 730                         head = &si->erase;
 731                 else
 732                         head = &si->corr;
 733
 734                 /*
 735                  * We try to erase the first physical eraseblock from the @head
 736                  * list and pick it if we succeed, or try to erase the
 737                  * next one if not. And so forth. We don't want to take care
 738                  * about bad eraseblocks here - they'll be handled later.
 739                  */
 740                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 741                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 742                                 seb->ec = si->mean_ec;
 743
 744                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 745                         if (err)
 746                                 continue;
 747
 748                         seb->ec += 1;
 749                         list_del(&seb->u.list);
 750                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 751                         return seb;
 752                 }
 753         }
 754
 755         ubi_err("no eraseblocks found");
 756         return ERR_PTR(-ENOSPC);
 757 }
 758
 759 /**
 760  * process_eb - read UBI headers, check them and add corresponding data
 761  * to the scanning information.
 762  * @ubi: UBI device description object
 763  * @si: scanning information
 764  * @pnum: the physical eraseblock number
 765  *
 766  * This function returns a zero if the physical eraseblock was successfully
 767  * handled and a negative error code in case of failure.
 768  */
 769 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 770 {
 771         long long ec;
 772         int err, bitflips = 0, vol_id, ec_corr = 0;
 773
 774         dbg_bld("scan PEB %d", pnum);
 775
 776         /* Skip bad physical eraseblocks */
 777         err = ubi_io_is_bad(ubi, pnum);
 778         if (err < 0)
 779                 return err;
 780         else if (err) {
 781                 /*
 782                  * FIXME: this is actually duty of the I/O unit to initialize
 783                  * this, but MTD does not provide enough information.
 784                  */
 785                 si->bad_peb_count += 1;
 786                 return 0;
 787         }
 788
 789         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 790         if (err < 0)
 791                 return err;
 792         else if (err == UBI_IO_BITFLIPS)
 793                 bitflips = 1;
 794         else if (err == UBI_IO_PEB_EMPTY)
 795                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 796         else if (err == UBI_IO_BAD_EC_HDR) {
 797                 /*
 798                  * We have to also look at the VID header, possibly it is not
 799                  * corrupted. Set %bitflips flag in order to make this PEB be
 800                  * moved and EC be re-created.
 801                  */
 802                 ec_corr = 1;
 803                 ec = UBI_SCAN_UNKNOWN_EC;
 804                 bitflips = 1;
 805         }
 806
 807         si->is_empty = 0;
 808
 809         if (!ec_corr) {
 810                 /* Make sure UBI version is OK */
 811                 if (ech->version != UBI_VERSION) {
 812                         ubi_err("this UBI version is %d, image version is %d",
 813                                 UBI_VERSION, (int)ech->version);
 814                         return -EINVAL;
 815                 }
 816
 817                 ec = ubi64_to_cpu(ech->ec);
 818                 if (ec > UBI_MAX_ERASECOUNTER) {
 819                         /*
 820                          * Erase counter overflow. The EC headers have 64 bits
 821                          * reserved, but we anyway make use of only 31 bit
 822                          * values, as this seems to be enough for any existing
 823                          * flash. Upgrade UBI and use 64-bit erase counters
 824                          * internally.
 825                          */
 826                         ubi_err("erase counter overflow, max is %d",
 827                                 UBI_MAX_ERASECOUNTER);
 828                         ubi_dbg_dump_ec_hdr(ech);
 829                         return -EINVAL;
 830                 }
 831         }
 832
 833         /* OK, we've done with the EC header, let's look at the VID header */
 834
 835         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 836         if (err < 0)
 837                 return err;
 838         else if (err == UBI_IO_BITFLIPS)
 839                 bitflips = 1;
 840         else if (err == UBI_IO_BAD_VID_HDR ||
 841                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 842                 /* VID header is corrupted */
 843                 err = add_to_list(si, pnum, ec, &si->corr);
 844                 if (err)
 845                         return err;
 846                 goto adjust_mean_ec;
 847         } else if (err == UBI_IO_PEB_FREE) {
 848                 /* No VID header - the physical eraseblock is free */
 849                 err = add_to_list(si, pnum, ec, &si->free);
 850                 if (err)
 851                         return err;
 852                 goto adjust_mean_ec;
 853         }
 854
 855         vol_id = ubi32_to_cpu(vidh->vol_id);
 856         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
 857                 int lnum = ubi32_to_cpu(vidh->lnum);
 858
 859                 /* Unsupported internal volume */
 860                 switch (vidh->compat) {
 861                 case UBI_COMPAT_DELETE:
 862                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 863                                 " found, remove it", vol_id, lnum);
 864                         err = add_to_list(si, pnum, ec, &si->corr);
 865                         if (err)
 866                                 return err;
 867                         break;
 868
 869                 case UBI_COMPAT_RO:
 870                         ubi_msg("read-only compatible internal volume %d:%d"
 871                                 " found, switch to read-only mode",
 872                                 vol_id, lnum);
 873                         ubi->ro_mode = 1;
 874                         break;
 875
 876                 case UBI_COMPAT_PRESERVE:
 877                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 878                                 " found", vol_id, lnum);
 879                         err = add_to_list(si, pnum, ec, &si->alien);
 880                         if (err)
 881                                 return err;
 882                         si->alien_peb_count += 1;
 883                         return 0;
 884
 885                 case UBI_COMPAT_REJECT:
 886                         ubi_err("incompatible internal volume %d:%d found",
 887                                 vol_id, lnum);
 888                         return -EINVAL;
 889                 }
 890         }
 891
 892         /* Both UBI headers seem to be fine */
 893         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 894         if (err)
 895                 return err;
 896
 897 adjust_mean_ec:
 898         if (!ec_corr) {
 899                 if (si->ec_sum + ec < ec) {
 900                         commit_to_mean_value(si);
 901                         si->ec_sum = 0;
 902                         si->ec_count = 0;
 903                 } else {
 904                         si->ec_sum += ec;
 905                         si->ec_count += 1;
 906                 }
 907
 908                 if (ec > si->max_ec)
 909                         si->max_ec = ec;
 910                 if (ec < si->min_ec)
 911                         si->min_ec = ec;
 912         }
 913
 914         return 0;
 915 }
 916
 917 /**
 918  * ubi_scan - scan an MTD device.
 919  * @ubi: UBI device description object
 920  *
 921  * This function does full scanning of an MTD device and returns complete
 922  * information about it. In case of failure, an error code is returned.
 923  */
 924 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 925 {
 926         int err, pnum;
 927         struct rb_node *rb1, *rb2;
 928         struct ubi_scan_volume *sv;
 929         struct ubi_scan_leb *seb;
 930         struct ubi_scan_info *si;
 931
 932         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 933         if (!si)
 934                 return ERR_PTR(-ENOMEM);
 935
 936         INIT_LIST_HEAD(&si->corr);
 937         INIT_LIST_HEAD(&si->free);
 938         INIT_LIST_HEAD(&si->erase);
 939         INIT_LIST_HEAD(&si->alien);
 940         si->volumes = RB_ROOT;
 941         si->is_empty = 1;
 942
 943         err = -ENOMEM;
 944         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 945         if (!ech)
 946                 goto out_si;
 947
 948         vidh = ubi_zalloc_vid_hdr(ubi);
 949         if (!vidh)
 950                 goto out_ech;
 951
 952         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 953                 cond_resched();
 954
 955                 dbg_msg("process PEB %d", pnum);
 956                 err = process_eb(ubi, si, pnum);
 957                 if (err < 0)
 958                         goto out_vidh;
 959         }
 960
 961         dbg_msg("scanning is finished");
 962
 963         /* Finish mean erase counter calculations */
 964         if (si->ec_count)
 965                 commit_to_mean_value(si);
 966
 967         if (si->is_empty)
 968                 ubi_msg("empty MTD device detected");
 969
 970         /*
 971          * In case of unknown erase counter we use the mean erase counter
 972          * value.
 973          */
 974         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 975                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 976                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 977                                 seb->ec = si->mean_ec;
 978         }
 979
 980         list_for_each_entry(seb, &si->free, u.list) {
 981                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 982                         seb->ec = si->mean_ec;
 983         }
 984
 985         list_for_each_entry(seb, &si->corr, u.list)
 986                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 987                         seb->ec = si->mean_ec;
 988
 989         list_for_each_entry(seb, &si->erase, u.list)
 990                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 991                         seb->ec = si->mean_ec;
 992
 993         err = paranoid_check_si(ubi, si);
 994         if (err) {
 995                 if (err > 0)
 996                         err = -EINVAL;
 997                 goto out_vidh;
 998         }
 999
1000         ubi_free_vid_hdr(ubi, vidh);
1001         kfree(ech);
1002
1003         return si;
1004
1005 out_vidh:
1006         ubi_free_vid_hdr(ubi, vidh);
1007 out_ech:
1008         kfree(ech);
1009 out_si:
1010         ubi_scan_destroy_si(si);
1011         return ERR_PTR(err);
1012 }
1013
1014 /**
1015  * destroy_sv - free the scanning volume information
1016  * @sv: scanning volume information
1017  *
1018  * This function destroys the volume RB-tree (@sv->root) and the scanning
1019  * volume information.
1020  */
1021 static void destroy_sv(struct ubi_scan_volume *sv)
1022 {
1023         struct ubi_scan_leb *seb;
1024         struct rb_node *this = sv->root.rb_node;
1025
1026         while (this) {
1027                 if (this->rb_left)
1028                         this = this->rb_left;
1029                 else if (this->rb_right)
1030                         this = this->rb_right;
1031                 else {
1032                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1033                         this = rb_parent(this);
1034                         if (this) {
1035                                 if (this->rb_left == &seb->u.rb)
1036                                         this->rb_left = NULL;
1037                                 else
1038                                         this->rb_right = NULL;
1039                         }
1040
1041                         kfree(seb);
1042                 }
1043         }
1044         kfree(sv);
1045 }
1046
1047 /**
1048  * ubi_scan_destroy_si - destroy scanning information.
1049  * @si: scanning information
1050  */
1051 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1052 {
1053         struct ubi_scan_leb *seb, *seb_tmp;
1054         struct ubi_scan_volume *sv;
1055         struct rb_node *rb;
1056
1057         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1058                 list_del(&seb->u.list);
1059                 kfree(seb);
1060         }
1061         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1062                 list_del(&seb->u.list);
1063                 kfree(seb);
1064         }
1065         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1066                 list_del(&seb->u.list);
1067                 kfree(seb);
1068         }
1069         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1070                 list_del(&seb->u.list);
1071                 kfree(seb);
1072         }
1073
1074         /* Destroy the volume RB-tree */
1075         rb = si->volumes.rb_node;
1076         while (rb) {
1077                 if (rb->rb_left)
1078                         rb = rb->rb_left;
1079                 else if (rb->rb_right)
1080                         rb = rb->rb_right;
1081                 else {
1082                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1083
1084                         rb = rb_parent(rb);
1085                         if (rb) {
1086                                 if (rb->rb_left == &sv->rb)
1087                                         rb->rb_left = NULL;
1088                                 else
1089                                         rb->rb_right = NULL;
1090                         }
1091
1092                         destroy_sv(sv);
1093                 }
1094         }
1095
1096         kfree(si);
1097 }
1098
1099 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1100
1101 /**
1102  * paranoid_check_si - check if the scanning information is correct and
1103  * consistent.
1104  * @ubi: UBI device description object
1105  * @si: scanning information
1106  *
1107  * This function returns zero if the scanning information is all right, %1 if
1108  * not and a negative error code if an error occurred.
1109  */
1110 static int paranoid_check_si(const struct ubi_device *ubi,
1111                              struct ubi_scan_info *si)
1112 {
1113         int pnum, err, vols_found = 0;
1114         struct rb_node *rb1, *rb2;
1115         struct ubi_scan_volume *sv;
1116         struct ubi_scan_leb *seb, *last_seb;
1117         uint8_t *buf;
1118
1119         /*
1120          * At first, check that scanning information is OK.
1121          */
1122         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1123                 int leb_count = 0;
1124
1125                 cond_resched();
1126
1127                 vols_found += 1;
1128
1129                 if (si->is_empty) {
1130                         ubi_err("bad is_empty flag");
1131                         goto bad_sv;
1132                 }
1133
1134                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1135                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1136                     sv->data_pad < 0 || sv->last_data_size < 0) {
1137                         ubi_err("negative values");
1138                         goto bad_sv;
1139                 }
1140
1141                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1142                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1143                         ubi_err("bad vol_id");
1144                         goto bad_sv;
1145                 }
1146
1147                 if (sv->vol_id > si->highest_vol_id) {
1148                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1149                                 si->highest_vol_id, sv->vol_id);
1150                         goto out;
1151                 }
1152
1153                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1154                     sv->vol_type != UBI_STATIC_VOLUME) {
1155                         ubi_err("bad vol_type");
1156                         goto bad_sv;
1157                 }
1158
1159                 if (sv->data_pad > ubi->leb_size / 2) {
1160                         ubi_err("bad data_pad");
1161                         goto bad_sv;
1162                 }
1163
1164                 last_seb = NULL;
1165                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1166                         cond_resched();
1167
1168                         last_seb = seb;
1169                         leb_count += 1;
1170
1171                         if (seb->pnum < 0 || seb->ec < 0) {
1172                                 ubi_err("negative values");
1173                                 goto bad_seb;
1174                         }
1175
1176                         if (seb->ec < si->min_ec) {
1177                                 ubi_err("bad si->min_ec (%d), %d found",
1178                                         si->min_ec, seb->ec);
1179                                 goto bad_seb;
1180                         }
1181
1182                         if (seb->ec > si->max_ec) {
1183                                 ubi_err("bad si->max_ec (%d), %d found",
1184                                         si->max_ec, seb->ec);
1185                                 goto bad_seb;
1186                         }
1187
1188                         if (seb->pnum >= ubi->peb_count) {
1189                                 ubi_err("too high PEB number %d, total PEBs %d",
1190                                         seb->pnum, ubi->peb_count);
1191                                 goto bad_seb;
1192                         }
1193
1194                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1195                                 if (seb->lnum >= sv->used_ebs) {
1196                                         ubi_err("bad lnum or used_ebs");
1197                                         goto bad_seb;
1198                                 }
1199                         } else {
1200                                 if (sv->used_ebs != 0) {
1201                                         ubi_err("non-zero used_ebs");
1202                                         goto bad_seb;
1203                                 }
1204                         }
1205
1206                         if (seb->lnum > sv->highest_lnum) {
1207                                 ubi_err("incorrect highest_lnum or lnum");
1208                                 goto bad_seb;
1209                         }
1210                 }
1211
1212                 if (sv->leb_count != leb_count) {
1213                         ubi_err("bad leb_count, %d objects in the tree",
1214                                 leb_count);
1215                         goto bad_sv;
1216                 }
1217
1218                 if (!last_seb)
1219                         continue;
1220
1221                 seb = last_seb;
1222
1223                 if (seb->lnum != sv->highest_lnum) {
1224                         ubi_err("bad highest_lnum");
1225                         goto bad_seb;
1226                 }
1227         }
1228
1229         if (vols_found != si->vols_found) {
1230                 ubi_err("bad si->vols_found %d, should be %d",
1231                         si->vols_found, vols_found);
1232                 goto out;
1233         }
1234
1235         /* Check that scanning information is correct */
1236         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1237                 last_seb = NULL;
1238                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1239                         int vol_type;
1240
1241                         cond_resched();
1242
1243                         last_seb = seb;
1244
1245                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1246                         if (err && err != UBI_IO_BITFLIPS) {
1247                                 ubi_err("VID header is not OK (%d)", err);
1248                                 if (err > 0)
1249                                         err = -EIO;
1250                                 return err;
1251                         }
1252
1253                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1254                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1255                         if (sv->vol_type != vol_type) {
1256                                 ubi_err("bad vol_type");
1257                                 goto bad_vid_hdr;
1258                         }
1259
1260                         if (seb->sqnum != ubi64_to_cpu(vidh->sqnum)) {
1261                                 ubi_err("bad sqnum %llu", seb->sqnum);
1262                                 goto bad_vid_hdr;
1263                         }
1264
1265                         if (sv->vol_id != ubi32_to_cpu(vidh->vol_id)) {
1266                                 ubi_err("bad vol_id %d", sv->vol_id);
1267                                 goto bad_vid_hdr;
1268                         }
1269
1270                         if (sv->compat != vidh->compat) {
1271                                 ubi_err("bad compat %d", vidh->compat);
1272                                 goto bad_vid_hdr;
1273                         }
1274
1275                         if (seb->lnum != ubi32_to_cpu(vidh->lnum)) {
1276                                 ubi_err("bad lnum %d", seb->lnum);
1277                                 goto bad_vid_hdr;
1278                         }
1279
1280                         if (sv->used_ebs != ubi32_to_cpu(vidh->used_ebs)) {
1281                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1282                                 goto bad_vid_hdr;
1283                         }
1284
1285                         if (sv->data_pad != ubi32_to_cpu(vidh->data_pad)) {
1286                                 ubi_err("bad data_pad %d", sv->data_pad);
1287                                 goto bad_vid_hdr;
1288                         }
1289
1290                         if (seb->leb_ver != ubi32_to_cpu(vidh->leb_ver)) {
1291                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1292                                 goto bad_vid_hdr;
1293                         }
1294                 }
1295
1296                 if (!last_seb)
1297                         continue;
1298
1299                 if (sv->highest_lnum != ubi32_to_cpu(vidh->lnum)) {
1300                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1301                         goto bad_vid_hdr;
1302                 }
1303
1304                 if (sv->last_data_size != ubi32_to_cpu(vidh->data_size)) {
1305                         ubi_err("bad last_data_size %d", sv->last_data_size);
1306                         goto bad_vid_hdr;
1307                 }
1308         }
1309
1310         /*
1311          * Make sure that all the physical eraseblocks are in one of the lists
1312          * or trees.
1313          */
1314         buf = kmalloc(ubi->peb_count, GFP_KERNEL);
1315         if (!buf)
1316                 return -ENOMEM;
1317
1318         memset(buf, 1, ubi->peb_count);
1319         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1320                 err = ubi_io_is_bad(ubi, pnum);
1321                 if (err < 0) {
1322                         kfree(buf);
1323                         return err;
1324                 }
1325                 else if (err)
1326                         buf[pnum] = 0;
1327         }
1328
1329         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1330                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1331                         buf[seb->pnum] = 0;
1332
1333         list_for_each_entry(seb, &si->free, u.list)
1334                 buf[seb->pnum] = 0;
1335
1336         list_for_each_entry(seb, &si->corr, u.list)
1337                 buf[seb->pnum] = 0;
1338
1339         list_for_each_entry(seb, &si->erase, u.list)
1340                 buf[seb->pnum] = 0;
1341
1342         list_for_each_entry(seb, &si->alien, u.list)
1343                 buf[seb->pnum] = 0;
1344
1345         err = 0;
1346         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1347                 if (buf[pnum]) {
1348                         ubi_err("PEB %d is not referred", pnum);
1349                         err = 1;
1350                 }
1351
1352         kfree(buf);
1353         if (err)
1354                 goto out;
1355         return 0;
1356
1357 bad_seb:
1358         ubi_err("bad scanning information about LEB %d", seb->lnum);
1359         ubi_dbg_dump_seb(seb, 0);
1360         ubi_dbg_dump_sv(sv);
1361         goto out;
1362
1363 bad_sv:
1364         ubi_err("bad scanning information about volume %d", sv->vol_id);
1365         ubi_dbg_dump_sv(sv);
1366         goto out;
1367
1368 bad_vid_hdr:
1369         ubi_err("bad scanning information about volume %d", sv->vol_id);
1370         ubi_dbg_dump_sv(sv);
1371         ubi_dbg_dump_vid_hdr(vidh);
1372
1373 out:
1374         ubi_dbg_dump_stack();
1375         return 1;
1376 }
1377
1378 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */