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 reoresented 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 int ubi_scan_add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  59                          struct list_head *list)
  60 {
  61         struct ubi_scan_leb *seb;
  62
  63         if (list == &si->free)
  64                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  65         else if (list == &si->erase)
  66                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  67         else if (list == &si->corr)
  68                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  69         else if (list == &si->alien)
  70                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  71         else
  72                 BUG();
  73
  74         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  75         if (!seb)
  76                 return -ENOMEM;
  77
  78         seb->pnum = pnum;
  79         seb->ec = ec;
  80         list_add_tail(&seb->u.list, list);
  81         return 0;
  82 }
  83
  84 /**
  85  * commit_to_mean_value - commit intermediate results to the final mean erase
  86  * counter value.
  87  * @si: scanning information
  88  *
  89  * This is a helper function which calculates partial mean erase counter mean
  90  * value and adds it to the resulting mean value. As we can work only in
  91  * integer arithmetic and we want to calculate the mean value of erase counter
  92  * accurately, we first sum erase counter values in @si->ec_sum variable and
  93  * count these components in @si->ec_count. If this temporary @si->ec_sum is
  94  * going to overflow, we calculate the partial mean value
  95  * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
  96  */
  97 static void commit_to_mean_value(struct ubi_scan_info *si)
  98 {
  99         si->ec_sum /= si->ec_count;
 100         if (si->ec_sum % si->ec_count >= si->ec_count / 2)
 101                 si->mean_ec += 1;
 102         si->mean_ec += si->ec_sum;
 103 }
 104
 105 /**
 106  * validate_vid_hdr - check that volume identifier header is correct and
 107  * consistent.
 108  * @vid_hdr: the volume identifier header to check
 109  * @sv: information about the volume this logical eraseblock belongs to
 110  * @pnum: physical eraseblock number the VID header came from
 111  *
 112  * This function checks that data stored in @vid_hdr is consistent. Returns
 113  * non-zero if an inconsistency was found and zero if not.
 114  *
 115  * Note, UBI does sanity check of everything it reads from the flash media.
 116  * Most of the checks are done in the I/O unit. Here we check that the
 117  * information in the VID header is consistent to the information in other VID
 118  * headers of the same volume.
 119  */
 120 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 121                             const struct ubi_scan_volume *sv, int pnum)
 122 {
 123         int vol_type = vid_hdr->vol_type;
 124         int vol_id = ubi32_to_cpu(vid_hdr->vol_id);
 125         int used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 126         int data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 127
 128         if (sv->leb_count != 0) {
 129                 int sv_vol_type;
 130
 131                 /*
 132                  * This is not the first logical eraseblock belonging to this
 133                  * volume. Ensure that the data in its VID header is consistent
 134                  * to the data in previous logical eraseblock headers.
 135                  */
 136
 137                 if (vol_id != sv->vol_id) {
 138                         dbg_err("inconsistent vol_id");
 139                         goto bad;
 140                 }
 141
 142                 if (sv->vol_type == UBI_STATIC_VOLUME)
 143                         sv_vol_type = UBI_VID_STATIC;
 144                 else
 145                         sv_vol_type = UBI_VID_DYNAMIC;
 146
 147                 if (vol_type != sv_vol_type) {
 148                         dbg_err("inconsistent vol_type");
 149                         goto bad;
 150                 }
 151
 152                 if (used_ebs != sv->used_ebs) {
 153                         dbg_err("inconsistent used_ebs");
 154                         goto bad;
 155                 }
 156
 157                 if (data_pad != sv->data_pad) {
 158                         dbg_err("inconsistent data_pad");
 159                         goto bad;
 160                 }
 161         }
 162
 163         return 0;
 164
 165 bad:
 166         ubi_err("inconsistent VID header at PEB %d", pnum);
 167         ubi_dbg_dump_vid_hdr(vid_hdr);
 168         ubi_dbg_dump_sv(sv);
 169         return -EINVAL;
 170 }
 171
 172 /**
 173  * add_volume - add volume to the scanning information.
 174  * @si: scanning information
 175  * @vol_id: ID of the volume to add
 176  * @pnum: physical eraseblock number
 177  * @vid_hdr: volume identifier header
 178  *
 179  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 180  * present in the scanning information, this function does nothing. Otherwise
 181  * it adds corresponding volume to the scanning information. Returns a pointer
 182  * to the scanning volume object in case of success and a negative error code
 183  * in case of failure.
 184  */
 185 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 186                                           int pnum,
 187                                           const struct ubi_vid_hdr *vid_hdr)
 188 {
 189         struct ubi_scan_volume *sv;
 190         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 191
 192         ubi_assert(vol_id == ubi32_to_cpu(vid_hdr->vol_id));
 193
 194         /* Walk the volume RB-tree to look if this volume is already present */
 195         while (*p) {
 196                 parent = *p;
 197                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 198
 199                 if (vol_id == sv->vol_id)
 200                         return sv;
 201
 202                 if (vol_id > sv->vol_id)
 203                         p = &(*p)->rb_left;
 204                 else
 205                         p = &(*p)->rb_right;
 206         }
 207
 208         /* The volume is absent - add it */
 209         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 210         if (!sv)
 211                 return ERR_PTR(-ENOMEM);
 212
 213         sv->highest_lnum = sv->leb_count = 0;
 214         si->max_sqnum = 0;
 215         sv->vol_id = vol_id;
 216         sv->root = RB_ROOT;
 217         sv->used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 218         sv->data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 219         sv->compat = vid_hdr->compat;
 220         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 221                                                             : UBI_STATIC_VOLUME;
 222         if (vol_id > si->highest_vol_id)
 223                 si->highest_vol_id = vol_id;
 224
 225         rb_link_node(&sv->rb, parent, p);
 226         rb_insert_color(&sv->rb, &si->volumes);
 227         si->vols_found += 1;
 228         dbg_bld("added volume %d", vol_id);
 229         return sv;
 230 }
 231
 232 /**
 233  * compare_lebs - find out which logical eraseblock is newer.
 234  * @ubi: UBI device description object
 235  * @seb: first logical eraseblock to compare
 236  * @pnum: physical eraseblock number of the second logical eraseblock to
 237  * compare
 238  * @vid_hdr: volume identifier header of the second logical eraseblock
 239  *
 240  * This function compares 2 copies of a LEB and informs which one is newer. In
 241  * case of success this function returns a positive value, in case of failure, a
 242  * negative error code is returned. The success return codes use the following
 243  * bits:
 244  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 245  *       second PEB (described by @pnum and @vid_hdr);
 246  *     o bit 0 is set: the second PEB is newer;
 247  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 248  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 249  *     o bit 2 is cleared: the older LEB is not corrupted;
 250  *     o bit 2 is set: the older LEB is corrupted.
 251  */
 252 static int compare_lebs(const struct ubi_device *ubi,
 253                         const struct ubi_scan_leb *seb, int pnum,
 254                         const struct ubi_vid_hdr *vid_hdr)
 255 {
 256         void *buf;
 257         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 258         uint32_t data_crc, crc;
 259         struct ubi_vid_hdr *vidh = NULL;
 260         unsigned long long sqnum2 = ubi64_to_cpu(vid_hdr->sqnum);
 261
 262         if (seb->sqnum == 0 && sqnum2 == 0) {
 263                 long long abs, v1 = seb->leb_ver, v2 = ubi32_to_cpu(vid_hdr->leb_ver);
 264
 265                 /*
 266                  * UBI constantly increases the logical eraseblock version
 267                  * number and it can overflow. Thus, we have to bear in mind
 268                  * that versions that are close to %0xFFFFFFFF are less then
 269                  * versions that are close to %0.
 270                  *
 271                  * The UBI WL unit guarantees that the number of pending tasks
 272                  * is not greater then %0x7FFFFFFF. So, if the difference
 273                  * between any two versions is greater or equivalent to
 274                  * %0x7FFFFFFF, there was an overflow and the logical
 275                  * eraseblock with lower version is actually newer then the one
 276                  * with higher version.
 277                  *
 278                  * FIXME: but this is anyway obsolete and will be removed at
 279                  * some point.
 280                  */
 281
 282                 dbg_bld("using old crappy leb_ver stuff");
 283
 284                 abs = v1 - v2;
 285                 if (abs < 0)
 286                         abs = -abs;
 287
 288                 if (abs < 0x7FFFFFFF)
 289                         /* Non-overflow situation */
 290                         second_is_newer = (v2 > v1);
 291                 else
 292                         second_is_newer = (v2 < v1);
 293         } else
 294                 /* Obviously the LEB with lower sequence counter is older */
 295                 second_is_newer = sqnum2 > seb->sqnum;
 296
 297         /*
 298          * Now we know which copy is newer. If the copy flag of the PEB with
 299          * newer version is not set, then we just return, otherwise we have to
 300          * check data CRC. For the second PEB we already have the VID header,
 301          * for the first one - we'll need to re-read it from flash.
 302          *
 303          * FIXME: this may be optimized so that we wouldn't read twice.
 304          */
 305
 306         if (second_is_newer) {
 307                 if (!vid_hdr->copy_flag) {
 308                         /* It is not a copy, so it is newer */
 309                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 310                                 pnum);
 311                         return 1;
 312                 }
 313         } else {
 314                 pnum = seb->pnum;
 315
 316                 vidh = ubi_zalloc_vid_hdr(ubi);
 317                 if (!vidh)
 318                         return -ENOMEM;
 319
 320                 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 321                 if (err) {
 322                         if (err == UBI_IO_BITFLIPS)
 323                                 bitflips = 1;
 324                         else {
 325                                 dbg_err("VID of PEB %d header is bad, but it "
 326                                         "was OK earlier", pnum);
 327                                 if (err > 0)
 328                                         err = -EIO;
 329
 330                                 goto out_free_vidh;
 331                         }
 332                 }
 333
 334                 if (!vidh->copy_flag) {
 335                         /* It is not a copy, so it is newer */
 336                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 337                                 pnum);
 338                         err = bitflips << 1;
 339                         goto out_free_vidh;
 340                 }
 341
 342                 vid_hdr = vidh;
 343         }
 344
 345         /* Read the data of the copy and check the CRC */
 346
 347         len = ubi32_to_cpu(vid_hdr->data_size);
 348         buf = kmalloc(len, GFP_KERNEL);
 349         if (!buf) {
 350                 err = -ENOMEM;
 351                 goto out_free_vidh;
 352         }
 353
 354         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 355         if (err && err != UBI_IO_BITFLIPS)
 356                 goto out_free_buf;
 357
 358         data_crc = ubi32_to_cpu(vid_hdr->data_crc);
 359         crc = crc32(UBI_CRC32_INIT, buf, len);
 360         if (crc != data_crc) {
 361                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 362                         pnum, crc, data_crc);
 363                 corrupted = 1;
 364                 bitflips = 0;
 365                 second_is_newer = !second_is_newer;
 366         } else {
 367                 dbg_bld("PEB %d CRC is OK", pnum);
 368                 bitflips = !!err;
 369         }
 370
 371         kfree(buf);
 372         ubi_free_vid_hdr(ubi, vidh);
 373
 374         if (second_is_newer)
 375                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 376         else
 377                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 378
 379         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 380
 381 out_free_buf:
 382         kfree(buf);
 383 out_free_vidh:
 384         ubi_free_vid_hdr(ubi, vidh);
 385         ubi_assert(err < 0);
 386         return err;
 387 }
 388
 389 /**
 390  * ubi_scan_add_used - add information about a physical eraseblock to the
 391  * scanning information.
 392  * @ubi: UBI device description object
 393  * @si: scanning information
 394  * @pnum: the physical eraseblock number
 395  * @ec: erase counter
 396  * @vid_hdr: the volume identifier header
 397  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 398  *
 399  * This function returns zero in case of success and a negative error code in
 400  * case of failure.
 401  */
 402 int ubi_scan_add_used(const 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 = ubi32_to_cpu(vid_hdr->vol_id);
 414         lnum = ubi32_to_cpu(vid_hdr->lnum);
 415         sqnum = ubi64_to_cpu(vid_hdr->sqnum);
 416         leb_ver = ubi32_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         /*
 426          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 427          * if this is the first instance of this logical eraseblock or not.
 428          */
 429         p = &sv->root.rb_node;
 430         while (*p) {
 431                 int cmp_res;
 432
 433                 parent = *p;
 434                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 435                 if (lnum != seb->lnum) {
 436                         if (lnum < seb->lnum)
 437                                 p = &(*p)->rb_left;
 438                         else
 439                                 p = &(*p)->rb_right;
 440                         continue;
 441                 }
 442
 443                 /*
 444                  * There is already a physical eraseblock describing the same
 445                  * logical eraseblock present.
 446                  */
 447
 448                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 449                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 450                         seb->leb_ver, seb->ec);
 451
 452                 /*
 453                  * Make sure that the logical eraseblocks have different
 454                  * versions. Otherwise the image is bad.
 455                  */
 456                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 457                         ubi_err("two LEBs with same version %u", leb_ver);
 458                         ubi_dbg_dump_seb(seb, 0);
 459                         ubi_dbg_dump_vid_hdr(vid_hdr);
 460                         return -EINVAL;
 461                 }
 462
 463                 /*
 464                  * Make sure that the logical eraseblocks have different
 465                  * sequence numbers. Otherwise the image is bad.
 466                  *
 467                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 468                  */
 469                 if (seb->sqnum == sqnum && sqnum != 0) {
 470                         ubi_err("two LEBs with same sequence number %llu",
 471                                 sqnum);
 472                         ubi_dbg_dump_seb(seb, 0);
 473                         ubi_dbg_dump_vid_hdr(vid_hdr);
 474                         return -EINVAL;
 475                 }
 476
 477                 /*
 478                  * Now we have to drop the older one and preserve the newer
 479                  * one.
 480                  */
 481                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 482                 if (cmp_res < 0)
 483                         return cmp_res;
 484
 485                 if (cmp_res & 1) {
 486                         /*
 487                          * This logical eraseblock is newer then the one
 488                          * found earlier.
 489                          */
 490                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 491                         if (err)
 492                                 return err;
 493
 494                         if (cmp_res & 4)
 495                                 err = ubi_scan_add_to_list(si, seb->pnum,
 496                                                            seb->ec, &si->corr);
 497                         else
 498                                 err = ubi_scan_add_to_list(si, seb->pnum,
 499                                                            seb->ec, &si->erase);
 500                         if (err)
 501                                 return err;
 502
 503                         seb->ec = ec;
 504                         seb->pnum = pnum;
 505                         seb->scrub = ((cmp_res & 2) || bitflips);
 506                         seb->sqnum = sqnum;
 507                         seb->leb_ver = leb_ver;
 508
 509                         if (sv->highest_lnum == lnum)
 510                                 sv->last_data_size =
 511                                         ubi32_to_cpu(vid_hdr->data_size);
 512
 513                         return 0;
 514                 } else {
 515                         /*
 516                          * This logical eraseblock is older then the one found
 517                          * previously.
 518                          */
 519                         if (cmp_res & 4)
 520                                 return ubi_scan_add_to_list(si, pnum, ec,
 521                                                             &si->corr);
 522                         else
 523                                 return ubi_scan_add_to_list(si, pnum, ec,
 524                                                             &si->erase);
 525                 }
 526         }
 527
 528         /*
 529          * We've met this logical eraseblock for the first time, add it to the
 530          * scanning information.
 531          */
 532
 533         err = validate_vid_hdr(vid_hdr, sv, pnum);
 534         if (err)
 535                 return err;
 536
 537         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 538         if (!seb)
 539                 return -ENOMEM;
 540
 541         seb->ec = ec;
 542         seb->pnum = pnum;
 543         seb->lnum = lnum;
 544         seb->sqnum = sqnum;
 545         seb->scrub = bitflips;
 546         seb->leb_ver = leb_ver;
 547
 548         if (sv->highest_lnum <= lnum) {
 549                 sv->highest_lnum = lnum;
 550                 sv->last_data_size = ubi32_to_cpu(vid_hdr->data_size);
 551         }
 552
 553         if (si->max_sqnum < sqnum)
 554                 si->max_sqnum = sqnum;
 555
 556         sv->leb_count += 1;
 557         rb_link_node(&seb->u.rb, parent, p);
 558         rb_insert_color(&seb->u.rb, &sv->root);
 559         return 0;
 560 }
 561
 562 /**
 563  * ubi_scan_find_sv - find information about a particular volume in the
 564  * scanning information.
 565  * @si: scanning information
 566  * @vol_id: the requested volume ID
 567  *
 568  * This function returns a pointer to the volume description or %NULL if there
 569  * are no data about this volume in the scanning information.
 570  */
 571 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 572                                          int vol_id)
 573 {
 574         struct ubi_scan_volume *sv;
 575         struct rb_node *p = si->volumes.rb_node;
 576
 577         while (p) {
 578                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 579
 580                 if (vol_id == sv->vol_id)
 581                         return sv;
 582
 583                 if (vol_id > sv->vol_id)
 584                         p = p->rb_left;
 585                 else
 586                         p = p->rb_right;
 587         }
 588
 589         return NULL;
 590 }
 591
 592 /**
 593  * ubi_scan_find_seb - find information about a particular logical
 594  * eraseblock in the volume scanning information.
 595  * @sv: a pointer to the volume scanning information
 596  * @lnum: the requested logical eraseblock
 597  *
 598  * This function returns a pointer to the scanning logical eraseblock or %NULL
 599  * if there are no data about it in the scanning volume information.
 600  */
 601 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 602                                        int lnum)
 603 {
 604         struct ubi_scan_leb *seb;
 605         struct rb_node *p = sv->root.rb_node;
 606
 607         while (p) {
 608                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 609
 610                 if (lnum == seb->lnum)
 611                         return seb;
 612
 613                 if (lnum > seb->lnum)
 614                         p = p->rb_left;
 615                 else
 616                         p = p->rb_right;
 617         }
 618
 619         return NULL;
 620 }
 621
 622 /**
 623  * ubi_scan_rm_volume - delete scanning information about a volume.
 624  * @si: scanning information
 625  * @sv: the volume scanning information to delete
 626  */
 627 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 628 {
 629         struct rb_node *rb;
 630         struct ubi_scan_leb *seb;
 631
 632         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 633
 634         while ((rb = rb_first(&sv->root))) {
 635                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 636                 rb_erase(&seb->u.rb, &sv->root);
 637                 list_add_tail(&seb->u.list, &si->erase);
 638         }
 639
 640         rb_erase(&sv->rb, &si->volumes);
 641         kfree(sv);
 642         si->vols_found -= 1;
 643 }
 644
 645 /**
 646  * ubi_scan_erase_peb - erase a physical eraseblock.
 647  * @ubi: UBI device description object
 648  * @si: scanning information
 649  * @pnum: physical eraseblock number to erase;
 650  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 651  *
 652  * This function erases physical eraseblock 'pnum', and writes the erase
 653  * counter header to it. This function should only be used on UBI device
 654  * initialization stages, when the EBA unit had not been yet initialized. This
 655  * function returns zero in case of success and a negative error code in case
 656  * of failure.
 657  */
 658 int ubi_scan_erase_peb(const struct ubi_device *ubi,
 659                        const struct ubi_scan_info *si, int pnum, int ec)
 660 {
 661         int err;
 662         struct ubi_ec_hdr *ec_hdr;
 663
 664         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 665         if (!ec_hdr)
 666                 return -ENOMEM;
 667
 668         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 669                 /*
 670                  * Erase counter overflow. Upgrade UBI and use 64-bit
 671                  * erase counters internally.
 672                  */
 673                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 674                 return -EINVAL;
 675         }
 676
 677         ec_hdr->ec = cpu_to_ubi64(ec);
 678
 679         err = ubi_io_sync_erase(ubi, pnum, 0);
 680         if (err < 0)
 681                 goto out_free;
 682
 683         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 684
 685 out_free:
 686         kfree(ec_hdr);
 687         return err;
 688 }
 689
 690 /**
 691  * ubi_scan_get_free_peb - get a free physical eraseblock.
 692  * @ubi: UBI device description object
 693  * @si: scanning information
 694  *
 695  * This function returns a free physical eraseblock. It is supposed to be
 696  * called on the UBI initialization stages when the wear-leveling unit is not
 697  * initialized yet. This function picks a physical eraseblocks from one of the
 698  * lists, writes the EC header if it is needed, and removes it from the list.
 699  *
 700  * This function returns scanning physical eraseblock information in case of
 701  * success and an error code in case of failure.
 702  */
 703 struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
 704                                            struct ubi_scan_info *si)
 705 {
 706         int err = 0, i;
 707         struct ubi_scan_leb *seb;
 708
 709         if (!list_empty(&si->free)) {
 710                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 711                 list_del(&seb->u.list);
 712                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 713                 return seb;
 714         }
 715
 716         for (i = 0; i < 2; i++) {
 717                 struct list_head *head;
 718                 struct ubi_scan_leb *tmp_seb;
 719
 720                 if (i == 0)
 721                         head = &si->erase;
 722                 else
 723                         head = &si->corr;
 724
 725                 /*
 726                  * We try to erase the first physical eraseblock from the @head
 727                  * list and pick it if we succeed, or try to erase the
 728                  * next one if not. And so forth. We don't want to take care
 729                  * about bad eraseblocks here - they'll be handled later.
 730                  */
 731                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 732                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 733                                 seb->ec = si->mean_ec;
 734
 735                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 736                         if (err)
 737                                 continue;
 738
 739                         seb->ec += 1;
 740                         list_del(&seb->u.list);
 741                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 742                         return seb;
 743                 }
 744         }
 745
 746         ubi_err("no eraseblocks found");
 747         return ERR_PTR(-ENOSPC);
 748 }
 749
 750 /**
 751  * process_eb - read UBI headers, check them and add corresponding data
 752  * to the scanning information.
 753  * @ubi: UBI device description object
 754  * @si: scanning information
 755  * @pnum: the physical eraseblock number
 756  *
 757  * This function returns a zero if the physical eraseblock was succesfully
 758  * handled and a negative error code in case of failure.
 759  */
 760 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 761 {
 762         long long ec;
 763         int err, bitflips = 0, vol_id, ec_corr = 0;
 764
 765         dbg_bld("scan PEB %d", pnum);
 766
 767         /* Skip bad physical eraseblocks */
 768         err = ubi_io_is_bad(ubi, pnum);
 769         if (err < 0)
 770                 return err;
 771         else if (err) {
 772                 /*
 773                  * FIXME: this is actually duty of the I/O unit to initialize
 774                  * this, but MTD does not provide enough information.
 775                  */
 776                 si->bad_peb_count += 1;
 777                 return 0;
 778         }
 779
 780         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 781         if (err < 0)
 782                 return err;
 783         else if (err == UBI_IO_BITFLIPS)
 784                 bitflips = 1;
 785         else if (err == UBI_IO_PEB_EMPTY)
 786                 return ubi_scan_add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC,
 787                                             &si->erase);
 788         else if (err == UBI_IO_BAD_EC_HDR) {
 789                 /*
 790                  * We have to also look at the VID header, possibly it is not
 791                  * corrupted. Set %bitflips flag in order to make this PEB be
 792                  * moved and EC be re-created.
 793                  */
 794                 ec_corr = 1;
 795                 ec = UBI_SCAN_UNKNOWN_EC;
 796                 bitflips = 1;
 797         }
 798
 799         si->is_empty = 0;
 800
 801         if (!ec_corr) {
 802                 /* Make sure UBI version is OK */
 803                 if (ech->version != UBI_VERSION) {
 804                         ubi_err("this UBI version is %d, image version is %d",
 805                                 UBI_VERSION, (int)ech->version);
 806                         return -EINVAL;
 807                 }
 808
 809                 ec = ubi64_to_cpu(ech->ec);
 810                 if (ec > UBI_MAX_ERASECOUNTER) {
 811                         /*
 812                          * Erase counter overflow. The EC headers have 64 bits
 813                          * reserved, but we anyway make use of only 31 bit
 814                          * values, as this seems to be enough for any existing
 815                          * flash. Upgrade UBI and use 64-bit erase counters
 816                          * internally.
 817                          */
 818                         ubi_err("erase counter overflow, max is %d",
 819                                 UBI_MAX_ERASECOUNTER);
 820                         ubi_dbg_dump_ec_hdr(ech);
 821                         return -EINVAL;
 822                 }
 823         }
 824
 825         /* OK, we've done with the EC header, let's look at the VID header */
 826
 827         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 828         if (err < 0)
 829                 return err;
 830         else if (err == UBI_IO_BITFLIPS)
 831                 bitflips = 1;
 832         else if (err == UBI_IO_BAD_VID_HDR ||
 833                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 834                 /* VID header is corrupted */
 835                 err = ubi_scan_add_to_list(si, pnum, ec, &si->corr);
 836                 if (err)
 837                         return err;
 838                 goto adjust_mean_ec;
 839         } else if (err == UBI_IO_PEB_FREE) {
 840                 /* No VID header - the physical eraseblock is free */
 841                 err = ubi_scan_add_to_list(si, pnum, ec, &si->free);
 842                 if (err)
 843                         return err;
 844                 goto adjust_mean_ec;
 845         }
 846
 847         vol_id = ubi32_to_cpu(vidh->vol_id);
 848         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
 849                 int lnum = ubi32_to_cpu(vidh->lnum);
 850
 851                 /* Unsupported internal volume */
 852                 switch (vidh->compat) {
 853                 case UBI_COMPAT_DELETE:
 854                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 855                                 " found, remove it", vol_id, lnum);
 856                         err = ubi_scan_add_to_list(si, pnum, ec, &si->corr);
 857                         if (err)
 858                                 return err;
 859                         break;
 860
 861                 case UBI_COMPAT_RO:
 862                         ubi_msg("read-only compatible internal volume %d:%d"
 863                                 " found, switch to read-only mode",
 864                                 vol_id, lnum);
 865                         ubi->ro_mode = 1;
 866                         break;
 867
 868                 case UBI_COMPAT_PRESERVE:
 869                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 870                                 " found", vol_id, lnum);
 871                         err = ubi_scan_add_to_list(si, pnum, ec, &si->alien);
 872                         if (err)
 873                                 return err;
 874                         si->alien_peb_count += 1;
 875                         return 0;
 876
 877                 case UBI_COMPAT_REJECT:
 878                         ubi_err("incompatible internal volume %d:%d found",
 879                                 vol_id, lnum);
 880                         return -EINVAL;
 881                 }
 882         }
 883
 884         /* Both UBI headers seem to be fine */
 885         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 886         if (err)
 887                 return err;
 888
 889 adjust_mean_ec:
 890         if (!ec_corr) {
 891                 if (si->ec_sum + ec < ec) {
 892                         commit_to_mean_value(si);
 893                         si->ec_sum = 0;
 894                         si->ec_count = 0;
 895                 } else {
 896                         si->ec_sum += ec;
 897                         si->ec_count += 1;
 898                 }
 899
 900                 if (ec > si->max_ec)
 901                         si->max_ec = ec;
 902                 if (ec < si->min_ec)
 903                         si->min_ec = ec;
 904         }
 905
 906         return 0;
 907 }
 908
 909 /**
 910  * ubi_scan - scan an MTD device.
 911  * @ubi: UBI device description object
 912  *
 913  * This function does full scanning of an MTD device and returns complete
 914  * information about it. In case of failure, an error code is returned.
 915  */
 916 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 917 {
 918         int err, pnum;
 919         struct rb_node *rb1, *rb2;
 920         struct ubi_scan_volume *sv;
 921         struct ubi_scan_leb *seb;
 922         struct ubi_scan_info *si;
 923
 924         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 925         if (!si)
 926                 return ERR_PTR(-ENOMEM);
 927
 928         INIT_LIST_HEAD(&si->corr);
 929         INIT_LIST_HEAD(&si->free);
 930         INIT_LIST_HEAD(&si->erase);
 931         INIT_LIST_HEAD(&si->alien);
 932         si->volumes = RB_ROOT;
 933         si->is_empty = 1;
 934
 935         err = -ENOMEM;
 936         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 937         if (!ech)
 938                 goto out_si;
 939
 940         vidh = ubi_zalloc_vid_hdr(ubi);
 941         if (!vidh)
 942                 goto out_ech;
 943
 944         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 945                 cond_resched();
 946
 947                 dbg_msg("process PEB %d", pnum);
 948                 err = process_eb(ubi, si, pnum);
 949                 if (err < 0)
 950                         goto out_vidh;
 951         }
 952
 953         dbg_msg("scanning is finished");
 954
 955         /* Finish mean erase counter calculations */
 956         if (si->ec_count)
 957                 commit_to_mean_value(si);
 958
 959         if (si->is_empty)
 960                 ubi_msg("empty MTD device detected");
 961
 962         /*
 963          * In case of unknown erase counter we use the mean erase counter
 964          * value.
 965          */
 966         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 967                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 968                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 969                                 seb->ec = si->mean_ec;
 970         }
 971
 972         list_for_each_entry(seb, &si->free, u.list) {
 973                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 974                         seb->ec = si->mean_ec;
 975         }
 976
 977         list_for_each_entry(seb, &si->corr, u.list)
 978                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 979                         seb->ec = si->mean_ec;
 980
 981         list_for_each_entry(seb, &si->erase, u.list)
 982                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 983                         seb->ec = si->mean_ec;
 984
 985         err = paranoid_check_si(ubi, si);
 986         if (err) {
 987                 if (err > 0)
 988                         err = -EINVAL;
 989                 goto out_vidh;
 990         }
 991
 992         ubi_free_vid_hdr(ubi, vidh);
 993         kfree(ech);
 994
 995         return si;
 996
 997 out_vidh:
 998         ubi_free_vid_hdr(ubi, vidh);
 999 out_ech:
1000         kfree(ech);
1001 out_si:
1002         ubi_scan_destroy_si(si);
1003         return ERR_PTR(err);
1004 }
1005
1006 /**
1007  * destroy_sv - free the scanning volume information
1008  * @sv: scanning volume information
1009  *
1010  * This function destroys the volume RB-tree (@sv->root) and the scanning
1011  * volume information.
1012  */
1013 static void destroy_sv(struct ubi_scan_volume *sv)
1014 {
1015         struct ubi_scan_leb *seb;
1016         struct rb_node *this = sv->root.rb_node;
1017
1018         while (this) {
1019                 if (this->rb_left)
1020                         this = this->rb_left;
1021                 else if (this->rb_right)
1022                         this = this->rb_right;
1023                 else {
1024                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1025                         this = rb_parent(this);
1026                         if (this) {
1027                                 if (this->rb_left == &seb->u.rb)
1028                                         this->rb_left = NULL;
1029                                 else
1030                                         this->rb_right = NULL;
1031                         }
1032
1033                         kfree(seb);
1034                 }
1035         }
1036         kfree(sv);
1037 }
1038
1039 /**
1040  * ubi_scan_destroy_si - destroy scanning information.
1041  * @si: scanning information
1042  */
1043 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1044 {
1045         struct ubi_scan_leb *seb, *seb_tmp;
1046         struct ubi_scan_volume *sv;
1047         struct rb_node *rb;
1048
1049         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1050                 list_del(&seb->u.list);
1051                 kfree(seb);
1052         }
1053         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1054                 list_del(&seb->u.list);
1055                 kfree(seb);
1056         }
1057         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1058                 list_del(&seb->u.list);
1059                 kfree(seb);
1060         }
1061         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1062                 list_del(&seb->u.list);
1063                 kfree(seb);
1064         }
1065
1066         /* Destroy the volume RB-tree */
1067         rb = si->volumes.rb_node;
1068         while (rb) {
1069                 if (rb->rb_left)
1070                         rb = rb->rb_left;
1071                 else if (rb->rb_right)
1072                         rb = rb->rb_right;
1073                 else {
1074                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1075
1076                         rb = rb_parent(rb);
1077                         if (rb) {
1078                                 if (rb->rb_left == &sv->rb)
1079                                         rb->rb_left = NULL;
1080                                 else
1081                                         rb->rb_right = NULL;
1082                         }
1083
1084                         destroy_sv(sv);
1085                 }
1086         }
1087
1088         kfree(si);
1089 }
1090
1091 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1092
1093 /**
1094  * paranoid_check_si - check if the scanning information is correct and
1095  * consistent.
1096  * @ubi: UBI device description object
1097  * @si: scanning information
1098  *
1099  * This function returns zero if the scanning information is all right, %1 if
1100  * not and a negative error code if an error occurred.
1101  */
1102 static int paranoid_check_si(const struct ubi_device *ubi,
1103                              struct ubi_scan_info *si)
1104 {
1105         int pnum, err, vols_found = 0;
1106         struct rb_node *rb1, *rb2;
1107         struct ubi_scan_volume *sv;
1108         struct ubi_scan_leb *seb, *last_seb;
1109         uint8_t *buf;
1110
1111         /*
1112          * At first, check that scanning information is ok.
1113          */
1114         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1115                 int leb_count = 0;
1116
1117                 cond_resched();
1118
1119                 vols_found += 1;
1120
1121                 if (si->is_empty) {
1122                         ubi_err("bad is_empty flag");
1123                         goto bad_sv;
1124                 }
1125
1126                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1127                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1128                     sv->data_pad < 0 || sv->last_data_size < 0) {
1129                         ubi_err("negative values");
1130                         goto bad_sv;
1131                 }
1132
1133                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1134                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1135                         ubi_err("bad vol_id");
1136                         goto bad_sv;
1137                 }
1138
1139                 if (sv->vol_id > si->highest_vol_id) {
1140                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1141                                 si->highest_vol_id, sv->vol_id);
1142                         goto out;
1143                 }
1144
1145                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1146                     sv->vol_type != UBI_STATIC_VOLUME) {
1147                         ubi_err("bad vol_type");
1148                         goto bad_sv;
1149                 }
1150
1151                 if (sv->data_pad > ubi->leb_size / 2) {
1152                         ubi_err("bad data_pad");
1153                         goto bad_sv;
1154                 }
1155
1156                 last_seb = NULL;
1157                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1158                         cond_resched();
1159
1160                         last_seb = seb;
1161                         leb_count += 1;
1162
1163                         if (seb->pnum < 0 || seb->ec < 0) {
1164                                 ubi_err("negative values");
1165                                 goto bad_seb;
1166                         }
1167
1168                         if (seb->ec < si->min_ec) {
1169                                 ubi_err("bad si->min_ec (%d), %d found",
1170                                         si->min_ec, seb->ec);
1171                                 goto bad_seb;
1172                         }
1173
1174                         if (seb->ec > si->max_ec) {
1175                                 ubi_err("bad si->max_ec (%d), %d found",
1176                                         si->max_ec, seb->ec);
1177                                 goto bad_seb;
1178                         }
1179
1180                         if (seb->pnum >= ubi->peb_count) {
1181                                 ubi_err("too high PEB number %d, total PEBs %d",
1182                                         seb->pnum, ubi->peb_count);
1183                                 goto bad_seb;
1184                         }
1185
1186                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1187                                 if (seb->lnum >= sv->used_ebs) {
1188                                         ubi_err("bad lnum or used_ebs");
1189                                         goto bad_seb;
1190                                 }
1191                         } else {
1192                                 if (sv->used_ebs != 0) {
1193                                         ubi_err("non-zero used_ebs");
1194                                         goto bad_seb;
1195                                 }
1196                         }
1197
1198                         if (seb->lnum > sv->highest_lnum) {
1199                                 ubi_err("incorrect highest_lnum or lnum");
1200                                 goto bad_seb;
1201                         }
1202                 }
1203
1204                 if (sv->leb_count != leb_count) {
1205                         ubi_err("bad leb_count, %d objects in the tree",
1206                                 leb_count);
1207                         goto bad_sv;
1208                 }
1209
1210                 if (!last_seb)
1211                         continue;
1212
1213                 seb = last_seb;
1214
1215                 if (seb->lnum != sv->highest_lnum) {
1216                         ubi_err("bad highest_lnum");
1217                         goto bad_seb;
1218                 }
1219         }
1220
1221         if (vols_found != si->vols_found) {
1222                 ubi_err("bad si->vols_found %d, should be %d",
1223                         si->vols_found, vols_found);
1224                 goto out;
1225         }
1226
1227         /* Check that scanning information is correct */
1228         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1229                 last_seb = NULL;
1230                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1231                         int vol_type;
1232
1233                         cond_resched();
1234
1235                         last_seb = seb;
1236
1237                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1238                         if (err && err != UBI_IO_BITFLIPS) {
1239                                 ubi_err("VID header is not OK (%d)", err);
1240                                 if (err > 0)
1241                                         err = -EIO;
1242                                 return err;
1243                         }
1244
1245                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1246                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1247                         if (sv->vol_type != vol_type) {
1248                                 ubi_err("bad vol_type");
1249                                 goto bad_vid_hdr;
1250                         }
1251
1252                         if (seb->sqnum != ubi64_to_cpu(vidh->sqnum)) {
1253                                 ubi_err("bad sqnum %llu", seb->sqnum);
1254                                 goto bad_vid_hdr;
1255                         }
1256
1257                         if (sv->vol_id != ubi32_to_cpu(vidh->vol_id)) {
1258                                 ubi_err("bad vol_id %d", sv->vol_id);
1259                                 goto bad_vid_hdr;
1260                         }
1261
1262                         if (sv->compat != vidh->compat) {
1263                                 ubi_err("bad compat %d", vidh->compat);
1264                                 goto bad_vid_hdr;
1265                         }
1266
1267                         if (seb->lnum != ubi32_to_cpu(vidh->lnum)) {
1268                                 ubi_err("bad lnum %d", seb->lnum);
1269                                 goto bad_vid_hdr;
1270                         }
1271
1272                         if (sv->used_ebs != ubi32_to_cpu(vidh->used_ebs)) {
1273                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1274                                 goto bad_vid_hdr;
1275                         }
1276
1277                         if (sv->data_pad != ubi32_to_cpu(vidh->data_pad)) {
1278                                 ubi_err("bad data_pad %d", sv->data_pad);
1279                                 goto bad_vid_hdr;
1280                         }
1281
1282                         if (seb->leb_ver != ubi32_to_cpu(vidh->leb_ver)) {
1283                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1284                                 goto bad_vid_hdr;
1285                         }
1286                 }
1287
1288                 if (!last_seb)
1289                         continue;
1290
1291                 if (sv->highest_lnum != ubi32_to_cpu(vidh->lnum)) {
1292                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1293                         goto bad_vid_hdr;
1294                 }
1295
1296                 if (sv->last_data_size != ubi32_to_cpu(vidh->data_size)) {
1297                         ubi_err("bad last_data_size %d", sv->last_data_size);
1298                         goto bad_vid_hdr;
1299                 }
1300         }
1301
1302         /*
1303          * Make sure that all the physical eraseblocks are in one of the lists
1304          * or trees.
1305          */
1306         buf = kmalloc(ubi->peb_count, GFP_KERNEL);
1307         if (!buf)
1308                 return -ENOMEM;
1309
1310         memset(buf, 1, ubi->peb_count);
1311         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1312                 err = ubi_io_is_bad(ubi, pnum);
1313                 if (err < 0)
1314                         return err;
1315                 else if (err)
1316                         buf[pnum] = 0;
1317         }
1318
1319         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1320                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1321                         buf[seb->pnum] = 0;
1322
1323         list_for_each_entry(seb, &si->free, u.list)
1324                 buf[seb->pnum] = 0;
1325
1326         list_for_each_entry(seb, &si->corr, u.list)
1327                 buf[seb->pnum] = 0;
1328
1329         list_for_each_entry(seb, &si->erase, u.list)
1330                 buf[seb->pnum] = 0;
1331
1332         list_for_each_entry(seb, &si->alien, u.list)
1333                 buf[seb->pnum] = 0;
1334
1335         err = 0;
1336         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1337                 if (buf[pnum]) {
1338                         ubi_err("PEB %d is not referred", pnum);
1339                         err = 1;
1340                 }
1341
1342         kfree(buf);
1343         if (err)
1344                 goto out;
1345         return 0;
1346
1347 bad_seb:
1348         ubi_err("bad scanning information about LEB %d", seb->lnum);
1349         ubi_dbg_dump_seb(seb, 0);
1350         ubi_dbg_dump_sv(sv);
1351         goto out;
1352
1353 bad_sv:
1354         ubi_err("bad scanning information about volume %d", sv->vol_id);
1355         ubi_dbg_dump_sv(sv);
1356         goto out;
1357
1358 bad_vid_hdr:
1359         ubi_err("bad scanning information about volume %d", sv->vol_id);
1360         ubi_dbg_dump_sv(sv);
1361         ubi_dbg_dump_vid_hdr(vidh);
1362
1363 out:
1364         ubi_dbg_dump_stack();
1365         return 1;
1366 }
1367
1368 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */