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(struct ubi_device *ubi, struct ubi_scan_info *si);
  49 #else
  50 #define paranoid_check_si(ubi, si) 0
  51 #endif
  52
  53 /* Temporary variables used during scanning */
  54 static struct ubi_ec_hdr *ech;
  55 static struct ubi_vid_hdr *vidh;
  56
  57 /**
  58  * add_to_list - add physical eraseblock to a list.
  59  * @si: scanning information
  60  * @pnum: physical eraseblock number to add
  61  * @ec: erase counter of the physical eraseblock
  62  * @list: the list to add to
  63  *
  64  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  65  * alien lists. Returns zero in case of success and a negative error code in
  66  * case of failure.
  67  */
  68 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  69                        struct list_head *list)
  70 {
  71         struct ubi_scan_leb *seb;
  72
  73         if (list == &si->free)
  74                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  75         else if (list == &si->erase)
  76                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  77         else if (list == &si->corr)
  78                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  79         else if (list == &si->alien)
  80                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  81         else
  82                 BUG();
  83
  84         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  85         if (!seb)
  86                 return -ENOMEM;
  87
  88         seb->pnum = pnum;
  89         seb->ec = ec;
  90         list_add_tail(&seb->u.list, list);
  91         return 0;
  92 }
  93
  94 /**
  95  * commit_to_mean_value - commit intermediate results to the final mean erase
  96  * counter value.
  97  * @si: scanning information
  98  *
  99  * This is a helper function which calculates partial mean erase counter mean
 100  * value and adds it to the resulting mean value. As we can work only in
 101  * integer arithmetic and we want to calculate the mean value of erase counter
 102  * accurately, we first sum erase counter values in @si->ec_sum variable and
 103  * count these components in @si->ec_count. If this temporary @si->ec_sum is
 104  * going to overflow, we calculate the partial mean value
 105  * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
 106  */
 107 static void commit_to_mean_value(struct ubi_scan_info *si)
 108 {
 109         si->ec_sum /= si->ec_count;
 110         if (si->ec_sum % si->ec_count >= si->ec_count / 2)
 111                 si->mean_ec += 1;
 112         si->mean_ec += si->ec_sum;
 113 }
 114
 115 /**
 116  * validate_vid_hdr - check that volume identifier header is correct and
 117  * consistent.
 118  * @vid_hdr: the volume identifier header to check
 119  * @sv: information about the volume this logical eraseblock belongs to
 120  * @pnum: physical eraseblock number the VID header came from
 121  *
 122  * This function checks that data stored in @vid_hdr is consistent. Returns
 123  * non-zero if an inconsistency was found and zero if not.
 124  *
 125  * Note, UBI does sanity check of everything it reads from the flash media.
 126  * Most of the checks are done in the I/O unit. Here we check that the
 127  * information in the VID header is consistent to the information in other VID
 128  * headers of the same volume.
 129  */
 130 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 131                             const struct ubi_scan_volume *sv, int pnum)
 132 {
 133         int vol_type = vid_hdr->vol_type;
 134         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 135         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 136         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 137
 138         if (sv->leb_count != 0) {
 139                 int sv_vol_type;
 140
 141                 /*
 142                  * This is not the first logical eraseblock belonging to this
 143                  * volume. Ensure that the data in its VID header is consistent
 144                  * to the data in previous logical eraseblock headers.
 145                  */
 146
 147                 if (vol_id != sv->vol_id) {
 148                         dbg_err("inconsistent vol_id");
 149                         goto bad;
 150                 }
 151
 152                 if (sv->vol_type == UBI_STATIC_VOLUME)
 153                         sv_vol_type = UBI_VID_STATIC;
 154                 else
 155                         sv_vol_type = UBI_VID_DYNAMIC;
 156
 157                 if (vol_type != sv_vol_type) {
 158                         dbg_err("inconsistent vol_type");
 159                         goto bad;
 160                 }
 161
 162                 if (used_ebs != sv->used_ebs) {
 163                         dbg_err("inconsistent used_ebs");
 164                         goto bad;
 165                 }
 166
 167                 if (data_pad != sv->data_pad) {
 168                         dbg_err("inconsistent data_pad");
 169                         goto bad;
 170                 }
 171         }
 172
 173         return 0;
 174
 175 bad:
 176         ubi_err("inconsistent VID header at PEB %d", pnum);
 177         ubi_dbg_dump_vid_hdr(vid_hdr);
 178         ubi_dbg_dump_sv(sv);
 179         return -EINVAL;
 180 }
 181
 182 /**
 183  * add_volume - add volume to the scanning information.
 184  * @si: scanning information
 185  * @vol_id: ID of the volume to add
 186  * @pnum: physical eraseblock number
 187  * @vid_hdr: volume identifier header
 188  *
 189  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 190  * present in the scanning information, this function does nothing. Otherwise
 191  * it adds corresponding volume to the scanning information. Returns a pointer
 192  * to the scanning volume object in case of success and a negative error code
 193  * in case of failure.
 194  */
 195 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 196                                           int pnum,
 197                                           const struct ubi_vid_hdr *vid_hdr)
 198 {
 199         struct ubi_scan_volume *sv;
 200         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 201
 202         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 203
 204         /* Walk the volume RB-tree to look if this volume is already present */
 205         while (*p) {
 206                 parent = *p;
 207                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 208
 209                 if (vol_id == sv->vol_id)
 210                         return sv;
 211
 212                 if (vol_id > sv->vol_id)
 213                         p = &(*p)->rb_left;
 214                 else
 215                         p = &(*p)->rb_right;
 216         }
 217
 218         /* The volume is absent - add it */
 219         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 220         if (!sv)
 221                 return ERR_PTR(-ENOMEM);
 222
 223         sv->highest_lnum = sv->leb_count = 0;
 224         sv->vol_id = vol_id;
 225         sv->root = RB_ROOT;
 226         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 227         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 228         sv->compat = vid_hdr->compat;
 229         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 230                                                             : UBI_STATIC_VOLUME;
 231         if (vol_id > si->highest_vol_id)
 232                 si->highest_vol_id = vol_id;
 233
 234         rb_link_node(&sv->rb, parent, p);
 235         rb_insert_color(&sv->rb, &si->volumes);
 236         si->vols_found += 1;
 237         dbg_bld("added volume %d", vol_id);
 238         return sv;
 239 }
 240
 241 /**
 242  * compare_lebs - find out which logical eraseblock is newer.
 243  * @ubi: UBI device description object
 244  * @seb: first logical eraseblock to compare
 245  * @pnum: physical eraseblock number of the second logical eraseblock to
 246  * compare
 247  * @vid_hdr: volume identifier header of the second logical eraseblock
 248  *
 249  * This function compares 2 copies of a LEB and informs which one is newer. In
 250  * case of success this function returns a positive value, in case of failure, a
 251  * negative error code is returned. The success return codes use the following
 252  * bits:
 253  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 254  *       second PEB (described by @pnum and @vid_hdr);
 255  *     o bit 0 is set: the second PEB is newer;
 256  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 257  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 258  *     o bit 2 is cleared: the older LEB is not corrupted;
 259  *     o bit 2 is set: the older LEB is corrupted.
 260  */
 261 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 262                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 263 {
 264         void *buf;
 265         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 266         uint32_t data_crc, crc;
 267         struct ubi_vid_hdr *vh = NULL;
 268         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 269
 270         if (seb->sqnum == 0 && sqnum2 == 0) {
 271                 long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
 272
 273                 /*
 274                  * UBI constantly increases the logical eraseblock version
 275                  * number and it can overflow. Thus, we have to bear in mind
 276                  * that versions that are close to %0xFFFFFFFF are less then
 277                  * versions that are close to %0.
 278                  *
 279                  * The UBI WL unit guarantees that the number of pending tasks
 280                  * is not greater then %0x7FFFFFFF. So, if the difference
 281                  * between any two versions is greater or equivalent to
 282                  * %0x7FFFFFFF, there was an overflow and the logical
 283                  * eraseblock with lower version is actually newer then the one
 284                  * with higher version.
 285                  *
 286                  * FIXME: but this is anyway obsolete and will be removed at
 287                  * some point.
 288                  */
 289                 dbg_bld("using old crappy leb_ver stuff");
 290
 291                 if (v1 == v2) {
 292                         ubi_err("PEB %d and PEB %d have the same version %lld",
 293                                 seb->pnum, pnum, v1);
 294                         return -EINVAL;
 295                 }
 296
 297                 abs = v1 - v2;
 298                 if (abs < 0)
 299                         abs = -abs;
 300
 301                 if (abs < 0x7FFFFFFF)
 302                         /* Non-overflow situation */
 303                         second_is_newer = (v2 > v1);
 304                 else
 305                         second_is_newer = (v2 < v1);
 306         } else
 307                 /* Obviously the LEB with lower sequence counter is older */
 308                 second_is_newer = sqnum2 > seb->sqnum;
 309
 310         /*
 311          * Now we know which copy is newer. If the copy flag of the PEB with
 312          * newer version is not set, then we just return, otherwise we have to
 313          * check data CRC. For the second PEB we already have the VID header,
 314          * for the first one - we'll need to re-read it from flash.
 315          *
 316          * FIXME: this may be optimized so that we wouldn't read twice.
 317          */
 318
 319         if (second_is_newer) {
 320                 if (!vid_hdr->copy_flag) {
 321                         /* It is not a copy, so it is newer */
 322                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 323                                 pnum);
 324                         return 1;
 325                 }
 326         } else {
 327                 pnum = seb->pnum;
 328
 329                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 330                 if (!vh)
 331                         return -ENOMEM;
 332
 333                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 334                 if (err) {
 335                         if (err == UBI_IO_BITFLIPS)
 336                                 bitflips = 1;
 337                         else {
 338                                 dbg_err("VID of PEB %d header is bad, but it "
 339                                         "was OK earlier", pnum);
 340                                 if (err > 0)
 341                                         err = -EIO;
 342
 343                                 goto out_free_vidh;
 344                         }
 345                 }
 346
 347                 if (!vh->copy_flag) {
 348                         /* It is not a copy, so it is newer */
 349                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 350                                 pnum);
 351                         err = bitflips << 1;
 352                         goto out_free_vidh;
 353                 }
 354
 355                 vid_hdr = vh;
 356         }
 357
 358         /* Read the data of the copy and check the CRC */
 359
 360         len = be32_to_cpu(vid_hdr->data_size);
 361         buf = vmalloc(len);
 362         if (!buf) {
 363                 err = -ENOMEM;
 364                 goto out_free_vidh;
 365         }
 366
 367         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 368         if (err && err != UBI_IO_BITFLIPS)
 369                 goto out_free_buf;
 370
 371         data_crc = be32_to_cpu(vid_hdr->data_crc);
 372         crc = crc32(UBI_CRC32_INIT, buf, len);
 373         if (crc != data_crc) {
 374                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 375                         pnum, crc, data_crc);
 376                 corrupted = 1;
 377                 bitflips = 0;
 378                 second_is_newer = !second_is_newer;
 379         } else {
 380                 dbg_bld("PEB %d CRC is OK", pnum);
 381                 bitflips = !!err;
 382         }
 383
 384         vfree(buf);
 385         ubi_free_vid_hdr(ubi, vh);
 386
 387         if (second_is_newer)
 388                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 389         else
 390                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 391
 392         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 393
 394 out_free_buf:
 395         vfree(buf);
 396 out_free_vidh:
 397         ubi_free_vid_hdr(ubi, vh);
 398         return err;
 399 }
 400
 401 /**
 402  * ubi_scan_add_used - add information about a physical eraseblock to the
 403  * scanning information.
 404  * @ubi: UBI device description object
 405  * @si: scanning information
 406  * @pnum: the physical eraseblock number
 407  * @ec: erase counter
 408  * @vid_hdr: the volume identifier header
 409  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 410  *
 411  * This function adds information about a used physical eraseblock to the
 412  * 'used' tree of the corresponding volume. The function is rather complex
 413  * because it has to handle cases when this is not the first physical
 414  * eraseblock belonging to the same logical eraseblock, and the newer one has
 415  * to be picked, while the older one has to be dropped. This function returns
 416  * zero in case of success and a negative error code in case of failure.
 417  */
 418 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 419                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 420                       int bitflips)
 421 {
 422         int err, vol_id, lnum;
 423         uint32_t leb_ver;
 424         unsigned long long sqnum;
 425         struct ubi_scan_volume *sv;
 426         struct ubi_scan_leb *seb;
 427         struct rb_node **p, *parent = NULL;
 428
 429         vol_id = be32_to_cpu(vid_hdr->vol_id);
 430         lnum = be32_to_cpu(vid_hdr->lnum);
 431         sqnum = be64_to_cpu(vid_hdr->sqnum);
 432         leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 433
 434         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 435                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 436
 437         sv = add_volume(si, vol_id, pnum, vid_hdr);
 438         if (IS_ERR(sv) < 0)
 439                 return PTR_ERR(sv);
 440
 441         if (si->max_sqnum < sqnum)
 442                 si->max_sqnum = sqnum;
 443
 444         /*
 445          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 446          * if this is the first instance of this logical eraseblock or not.
 447          */
 448         p = &sv->root.rb_node;
 449         while (*p) {
 450                 int cmp_res;
 451
 452                 parent = *p;
 453                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 454                 if (lnum != seb->lnum) {
 455                         if (lnum < seb->lnum)
 456                                 p = &(*p)->rb_left;
 457                         else
 458                                 p = &(*p)->rb_right;
 459                         continue;
 460                 }
 461
 462                 /*
 463                  * There is already a physical eraseblock describing the same
 464                  * logical eraseblock present.
 465                  */
 466
 467                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 468                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 469                         seb->leb_ver, seb->ec);
 470
 471                 /*
 472                  * Make sure that the logical eraseblocks have different
 473                  * versions. Otherwise the image is bad.
 474                  */
 475                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 476                         ubi_err("two LEBs with same version %u", leb_ver);
 477                         ubi_dbg_dump_seb(seb, 0);
 478                         ubi_dbg_dump_vid_hdr(vid_hdr);
 479                         return -EINVAL;
 480                 }
 481
 482                 /*
 483                  * Make sure that the logical eraseblocks have different
 484                  * sequence numbers. Otherwise the image is bad.
 485                  *
 486                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 487                  */
 488                 if (seb->sqnum == sqnum && sqnum != 0) {
 489                         ubi_err("two LEBs with same sequence number %llu",
 490                                 sqnum);
 491                         ubi_dbg_dump_seb(seb, 0);
 492                         ubi_dbg_dump_vid_hdr(vid_hdr);
 493                         return -EINVAL;
 494                 }
 495
 496                 /*
 497                  * Now we have to drop the older one and preserve the newer
 498                  * one.
 499                  */
 500                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 501                 if (cmp_res < 0)
 502                         return cmp_res;
 503
 504                 if (cmp_res & 1) {
 505                         /*
 506                          * This logical eraseblock is newer then the one
 507                          * found earlier.
 508                          */
 509                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 510                         if (err)
 511                                 return err;
 512
 513                         if (cmp_res & 4)
 514                                 err = add_to_list(si, seb->pnum, seb->ec,
 515                                                   &si->corr);
 516                         else
 517                                 err = add_to_list(si, seb->pnum, seb->ec,
 518                                                   &si->erase);
 519                         if (err)
 520                                 return err;
 521
 522                         seb->ec = ec;
 523                         seb->pnum = pnum;
 524                         seb->scrub = ((cmp_res & 2) || bitflips);
 525                         seb->sqnum = sqnum;
 526                         seb->leb_ver = leb_ver;
 527
 528                         if (sv->highest_lnum == lnum)
 529                                 sv->last_data_size =
 530                                         be32_to_cpu(vid_hdr->data_size);
 531
 532                         return 0;
 533                 } else {
 534                         /*
 535                          * This logical eraseblock is older then the one found
 536                          * previously.
 537                          */
 538                         if (cmp_res & 4)
 539                                 return add_to_list(si, pnum, ec, &si->corr);
 540                         else
 541                                 return add_to_list(si, pnum, ec, &si->erase);
 542                 }
 543         }
 544
 545         /*
 546          * We've met this logical eraseblock for the first time, add it to the
 547          * scanning information.
 548          */
 549
 550         err = validate_vid_hdr(vid_hdr, sv, pnum);
 551         if (err)
 552                 return err;
 553
 554         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 555         if (!seb)
 556                 return -ENOMEM;
 557
 558         seb->ec = ec;
 559         seb->pnum = pnum;
 560         seb->lnum = lnum;
 561         seb->sqnum = sqnum;
 562         seb->scrub = bitflips;
 563         seb->leb_ver = leb_ver;
 564
 565         if (sv->highest_lnum <= lnum) {
 566                 sv->highest_lnum = lnum;
 567                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 568         }
 569
 570         sv->leb_count += 1;
 571         rb_link_node(&seb->u.rb, parent, p);
 572         rb_insert_color(&seb->u.rb, &sv->root);
 573         return 0;
 574 }
 575
 576 /**
 577  * ubi_scan_find_sv - find information about a particular volume in the
 578  * scanning information.
 579  * @si: scanning information
 580  * @vol_id: the requested volume ID
 581  *
 582  * This function returns a pointer to the volume description or %NULL if there
 583  * are no data about this volume in the scanning information.
 584  */
 585 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 586                                          int vol_id)
 587 {
 588         struct ubi_scan_volume *sv;
 589         struct rb_node *p = si->volumes.rb_node;
 590
 591         while (p) {
 592                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 593
 594                 if (vol_id == sv->vol_id)
 595                         return sv;
 596
 597                 if (vol_id > sv->vol_id)
 598                         p = p->rb_left;
 599                 else
 600                         p = p->rb_right;
 601         }
 602
 603         return NULL;
 604 }
 605
 606 /**
 607  * ubi_scan_find_seb - find information about a particular logical
 608  * eraseblock in the volume scanning information.
 609  * @sv: a pointer to the volume scanning information
 610  * @lnum: the requested logical eraseblock
 611  *
 612  * This function returns a pointer to the scanning logical eraseblock or %NULL
 613  * if there are no data about it in the scanning volume information.
 614  */
 615 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 616                                        int lnum)
 617 {
 618         struct ubi_scan_leb *seb;
 619         struct rb_node *p = sv->root.rb_node;
 620
 621         while (p) {
 622                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 623
 624                 if (lnum == seb->lnum)
 625                         return seb;
 626
 627                 if (lnum > seb->lnum)
 628                         p = p->rb_left;
 629                 else
 630                         p = p->rb_right;
 631         }
 632
 633         return NULL;
 634 }
 635
 636 /**
 637  * ubi_scan_rm_volume - delete scanning information about a volume.
 638  * @si: scanning information
 639  * @sv: the volume scanning information to delete
 640  */
 641 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 642 {
 643         struct rb_node *rb;
 644         struct ubi_scan_leb *seb;
 645
 646         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 647
 648         while ((rb = rb_first(&sv->root))) {
 649                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 650                 rb_erase(&seb->u.rb, &sv->root);
 651                 list_add_tail(&seb->u.list, &si->erase);
 652         }
 653
 654         rb_erase(&sv->rb, &si->volumes);
 655         kfree(sv);
 656         si->vols_found -= 1;
 657 }
 658
 659 /**
 660  * ubi_scan_erase_peb - erase a physical eraseblock.
 661  * @ubi: UBI device description object
 662  * @si: scanning information
 663  * @pnum: physical eraseblock number to erase;
 664  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 665  *
 666  * This function erases physical eraseblock 'pnum', and writes the erase
 667  * counter header to it. This function should only be used on UBI device
 668  * initialization stages, when the EBA unit had not been yet initialized. This
 669  * function returns zero in case of success and a negative error code in case
 670  * of failure.
 671  */
 672 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 673                        int pnum, int ec)
 674 {
 675         int err;
 676         struct ubi_ec_hdr *ec_hdr;
 677
 678         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 679                 /*
 680                  * Erase counter overflow. Upgrade UBI and use 64-bit
 681                  * erase counters internally.
 682                  */
 683                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 684                 return -EINVAL;
 685         }
 686
 687         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 688         if (!ec_hdr)
 689                 return -ENOMEM;
 690
 691         ec_hdr->ec = cpu_to_be64(ec);
 692
 693         err = ubi_io_sync_erase(ubi, pnum, 0);
 694         if (err < 0)
 695                 goto out_free;
 696
 697         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 698
 699 out_free:
 700         kfree(ec_hdr);
 701         return err;
 702 }
 703
 704 /**
 705  * ubi_scan_get_free_peb - get a free physical eraseblock.
 706  * @ubi: UBI device description object
 707  * @si: scanning information
 708  *
 709  * This function returns a free physical eraseblock. It is supposed to be
 710  * called on the UBI initialization stages when the wear-leveling unit is not
 711  * initialized yet. This function picks a physical eraseblocks from one of the
 712  * lists, writes the EC header if it is needed, and removes it from the list.
 713  *
 714  * This function returns scanning physical eraseblock information in case of
 715  * success and an error code in case of failure.
 716  */
 717 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 718                                            struct ubi_scan_info *si)
 719 {
 720         int err = 0, i;
 721         struct ubi_scan_leb *seb;
 722
 723         if (!list_empty(&si->free)) {
 724                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 725                 list_del(&seb->u.list);
 726                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 727                 return seb;
 728         }
 729
 730         for (i = 0; i < 2; i++) {
 731                 struct list_head *head;
 732                 struct ubi_scan_leb *tmp_seb;
 733
 734                 if (i == 0)
 735                         head = &si->erase;
 736                 else
 737                         head = &si->corr;
 738
 739                 /*
 740                  * We try to erase the first physical eraseblock from the @head
 741                  * list and pick it if we succeed, or try to erase the
 742                  * next one if not. And so forth. We don't want to take care
 743                  * about bad eraseblocks here - they'll be handled later.
 744                  */
 745                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 746                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 747                                 seb->ec = si->mean_ec;
 748
 749                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 750                         if (err)
 751                                 continue;
 752
 753                         seb->ec += 1;
 754                         list_del(&seb->u.list);
 755                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 756                         return seb;
 757                 }
 758         }
 759
 760         ubi_err("no eraseblocks found");
 761         return ERR_PTR(-ENOSPC);
 762 }
 763
 764 /**
 765  * process_eb - read UBI headers, check them and add corresponding data
 766  * to the scanning information.
 767  * @ubi: UBI device description object
 768  * @si: scanning information
 769  * @pnum: the physical eraseblock number
 770  *
 771  * This function returns a zero if the physical eraseblock was successfully
 772  * handled and a negative error code in case of failure.
 773  */
 774 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 775 {
 776         long long uninitialized_var(ec);
 777         int err, bitflips = 0, vol_id, ec_corr = 0;
 778
 779         dbg_bld("scan PEB %d", pnum);
 780
 781         /* Skip bad physical eraseblocks */
 782         err = ubi_io_is_bad(ubi, pnum);
 783         if (err < 0)
 784                 return err;
 785         else if (err) {
 786                 /*
 787                  * FIXME: this is actually duty of the I/O unit to initialize
 788                  * this, but MTD does not provide enough information.
 789                  */
 790                 si->bad_peb_count += 1;
 791                 return 0;
 792         }
 793
 794         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 795         if (err < 0)
 796                 return err;
 797         else if (err == UBI_IO_BITFLIPS)
 798                 bitflips = 1;
 799         else if (err == UBI_IO_PEB_EMPTY)
 800                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 801         else if (err == UBI_IO_BAD_EC_HDR) {
 802                 /*
 803                  * We have to also look at the VID header, possibly it is not
 804                  * corrupted. Set %bitflips flag in order to make this PEB be
 805                  * moved and EC be re-created.
 806                  */
 807                 ec_corr = 1;
 808                 ec = UBI_SCAN_UNKNOWN_EC;
 809                 bitflips = 1;
 810         }
 811
 812         si->is_empty = 0;
 813
 814         if (!ec_corr) {
 815                 /* Make sure UBI version is OK */
 816                 if (ech->version != UBI_VERSION) {
 817                         ubi_err("this UBI version is %d, image version is %d",
 818                                 UBI_VERSION, (int)ech->version);
 819                         return -EINVAL;
 820                 }
 821
 822                 ec = be64_to_cpu(ech->ec);
 823                 if (ec > UBI_MAX_ERASECOUNTER) {
 824                         /*
 825                          * Erase counter overflow. The EC headers have 64 bits
 826                          * reserved, but we anyway make use of only 31 bit
 827                          * values, as this seems to be enough for any existing
 828                          * flash. Upgrade UBI and use 64-bit erase counters
 829                          * internally.
 830                          */
 831                         ubi_err("erase counter overflow, max is %d",
 832                                 UBI_MAX_ERASECOUNTER);
 833                         ubi_dbg_dump_ec_hdr(ech);
 834                         return -EINVAL;
 835                 }
 836         }
 837
 838         /* OK, we've done with the EC header, let's look at the VID header */
 839
 840         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 841         if (err < 0)
 842                 return err;
 843         else if (err == UBI_IO_BITFLIPS)
 844                 bitflips = 1;
 845         else if (err == UBI_IO_BAD_VID_HDR ||
 846                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 847                 /* VID header is corrupted */
 848                 err = add_to_list(si, pnum, ec, &si->corr);
 849                 if (err)
 850                         return err;
 851                 goto adjust_mean_ec;
 852         } else if (err == UBI_IO_PEB_FREE) {
 853                 /* No VID header - the physical eraseblock is free */
 854                 err = add_to_list(si, pnum, ec, &si->free);
 855                 if (err)
 856                         return err;
 857                 goto adjust_mean_ec;
 858         }
 859
 860         vol_id = be32_to_cpu(vidh->vol_id);
 861         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 862                 int lnum = be32_to_cpu(vidh->lnum);
 863
 864                 /* Unsupported internal volume */
 865                 switch (vidh->compat) {
 866                 case UBI_COMPAT_DELETE:
 867                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 868                                 " found, remove it", vol_id, lnum);
 869                         err = add_to_list(si, pnum, ec, &si->corr);
 870                         if (err)
 871                                 return err;
 872                         break;
 873
 874                 case UBI_COMPAT_RO:
 875                         ubi_msg("read-only compatible internal volume %d:%d"
 876                                 " found, switch to read-only mode",
 877                                 vol_id, lnum);
 878                         ubi->ro_mode = 1;
 879                         break;
 880
 881                 case UBI_COMPAT_PRESERVE:
 882                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 883                                 " found", vol_id, lnum);
 884                         err = add_to_list(si, pnum, ec, &si->alien);
 885                         if (err)
 886                                 return err;
 887                         si->alien_peb_count += 1;
 888                         return 0;
 889
 890                 case UBI_COMPAT_REJECT:
 891                         ubi_err("incompatible internal volume %d:%d found",
 892                                 vol_id, lnum);
 893                         return -EINVAL;
 894                 }
 895         }
 896
 897         /* Both UBI headers seem to be fine */
 898         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 899         if (err)
 900                 return err;
 901
 902 adjust_mean_ec:
 903         if (!ec_corr) {
 904                 if (si->ec_sum + ec < ec) {
 905                         commit_to_mean_value(si);
 906                         si->ec_sum = 0;
 907                         si->ec_count = 0;
 908                 } else {
 909                         si->ec_sum += ec;
 910                         si->ec_count += 1;
 911                 }
 912
 913                 if (ec > si->max_ec)
 914                         si->max_ec = ec;
 915                 if (ec < si->min_ec)
 916                         si->min_ec = ec;
 917         }
 918
 919         return 0;
 920 }
 921
 922 /**
 923  * ubi_scan - scan an MTD device.
 924  * @ubi: UBI device description object
 925  *
 926  * This function does full scanning of an MTD device and returns complete
 927  * information about it. In case of failure, an error code is returned.
 928  */
 929 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 930 {
 931         int err, pnum;
 932         struct rb_node *rb1, *rb2;
 933         struct ubi_scan_volume *sv;
 934         struct ubi_scan_leb *seb;
 935         struct ubi_scan_info *si;
 936
 937         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 938         if (!si)
 939                 return ERR_PTR(-ENOMEM);
 940
 941         INIT_LIST_HEAD(&si->corr);
 942         INIT_LIST_HEAD(&si->free);
 943         INIT_LIST_HEAD(&si->erase);
 944         INIT_LIST_HEAD(&si->alien);
 945         si->volumes = RB_ROOT;
 946         si->is_empty = 1;
 947
 948         err = -ENOMEM;
 949         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 950         if (!ech)
 951                 goto out_si;
 952
 953         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 954         if (!vidh)
 955                 goto out_ech;
 956
 957         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 958                 cond_resched();
 959
 960                 dbg_msg("process PEB %d", pnum);
 961                 err = process_eb(ubi, si, pnum);
 962                 if (err < 0)
 963                         goto out_vidh;
 964         }
 965
 966         dbg_msg("scanning is finished");
 967
 968         /* Finish mean erase counter calculations */
 969         if (si->ec_count)
 970                 commit_to_mean_value(si);
 971
 972         if (si->is_empty)
 973                 ubi_msg("empty MTD device detected");
 974
 975         /*
 976          * In case of unknown erase counter we use the mean erase counter
 977          * value.
 978          */
 979         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 980                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 981                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 982                                 seb->ec = si->mean_ec;
 983         }
 984
 985         list_for_each_entry(seb, &si->free, u.list) {
 986                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 987                         seb->ec = si->mean_ec;
 988         }
 989
 990         list_for_each_entry(seb, &si->corr, u.list)
 991                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 992                         seb->ec = si->mean_ec;
 993
 994         list_for_each_entry(seb, &si->erase, u.list)
 995                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 996                         seb->ec = si->mean_ec;
 997
 998         err = paranoid_check_si(ubi, si);
 999         if (err) {
1000                 if (err > 0)
1001                         err = -EINVAL;
1002                 goto out_vidh;
1003         }
1004
1005         ubi_free_vid_hdr(ubi, vidh);
1006         kfree(ech);
1007
1008         return si;
1009
1010 out_vidh:
1011         ubi_free_vid_hdr(ubi, vidh);
1012 out_ech:
1013         kfree(ech);
1014 out_si:
1015         ubi_scan_destroy_si(si);
1016         return ERR_PTR(err);
1017 }
1018
1019 /**
1020  * destroy_sv - free the scanning volume information
1021  * @sv: scanning volume information
1022  *
1023  * This function destroys the volume RB-tree (@sv->root) and the scanning
1024  * volume information.
1025  */
1026 static void destroy_sv(struct ubi_scan_volume *sv)
1027 {
1028         struct ubi_scan_leb *seb;
1029         struct rb_node *this = sv->root.rb_node;
1030
1031         while (this) {
1032                 if (this->rb_left)
1033                         this = this->rb_left;
1034                 else if (this->rb_right)
1035                         this = this->rb_right;
1036                 else {
1037                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1038                         this = rb_parent(this);
1039                         if (this) {
1040                                 if (this->rb_left == &seb->u.rb)
1041                                         this->rb_left = NULL;
1042                                 else
1043                                         this->rb_right = NULL;
1044                         }
1045
1046                         kfree(seb);
1047                 }
1048         }
1049         kfree(sv);
1050 }
1051
1052 /**
1053  * ubi_scan_destroy_si - destroy scanning information.
1054  * @si: scanning information
1055  */
1056 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1057 {
1058         struct ubi_scan_leb *seb, *seb_tmp;
1059         struct ubi_scan_volume *sv;
1060         struct rb_node *rb;
1061
1062         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1063                 list_del(&seb->u.list);
1064                 kfree(seb);
1065         }
1066         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1067                 list_del(&seb->u.list);
1068                 kfree(seb);
1069         }
1070         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1071                 list_del(&seb->u.list);
1072                 kfree(seb);
1073         }
1074         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1075                 list_del(&seb->u.list);
1076                 kfree(seb);
1077         }
1078
1079         /* Destroy the volume RB-tree */
1080         rb = si->volumes.rb_node;
1081         while (rb) {
1082                 if (rb->rb_left)
1083                         rb = rb->rb_left;
1084                 else if (rb->rb_right)
1085                         rb = rb->rb_right;
1086                 else {
1087                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1088
1089                         rb = rb_parent(rb);
1090                         if (rb) {
1091                                 if (rb->rb_left == &sv->rb)
1092                                         rb->rb_left = NULL;
1093                                 else
1094                                         rb->rb_right = NULL;
1095                         }
1096
1097                         destroy_sv(sv);
1098                 }
1099         }
1100
1101         kfree(si);
1102 }
1103
1104 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1105
1106 /**
1107  * paranoid_check_si - check if the scanning information is correct and
1108  * consistent.
1109  * @ubi: UBI device description object
1110  * @si: scanning information
1111  *
1112  * This function returns zero if the scanning information is all right, %1 if
1113  * not and a negative error code if an error occurred.
1114  */
1115 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1116 {
1117         int pnum, err, vols_found = 0;
1118         struct rb_node *rb1, *rb2;
1119         struct ubi_scan_volume *sv;
1120         struct ubi_scan_leb *seb, *last_seb;
1121         uint8_t *buf;
1122
1123         /*
1124          * At first, check that scanning information is OK.
1125          */
1126         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1127                 int leb_count = 0;
1128
1129                 cond_resched();
1130
1131                 vols_found += 1;
1132
1133                 if (si->is_empty) {
1134                         ubi_err("bad is_empty flag");
1135                         goto bad_sv;
1136                 }
1137
1138                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1139                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1140                     sv->data_pad < 0 || sv->last_data_size < 0) {
1141                         ubi_err("negative values");
1142                         goto bad_sv;
1143                 }
1144
1145                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1146                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1147                         ubi_err("bad vol_id");
1148                         goto bad_sv;
1149                 }
1150
1151                 if (sv->vol_id > si->highest_vol_id) {
1152                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1153                                 si->highest_vol_id, sv->vol_id);
1154                         goto out;
1155                 }
1156
1157                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1158                     sv->vol_type != UBI_STATIC_VOLUME) {
1159                         ubi_err("bad vol_type");
1160                         goto bad_sv;
1161                 }
1162
1163                 if (sv->data_pad > ubi->leb_size / 2) {
1164                         ubi_err("bad data_pad");
1165                         goto bad_sv;
1166                 }
1167
1168                 last_seb = NULL;
1169                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1170                         cond_resched();
1171
1172                         last_seb = seb;
1173                         leb_count += 1;
1174
1175                         if (seb->pnum < 0 || seb->ec < 0) {
1176                                 ubi_err("negative values");
1177                                 goto bad_seb;
1178                         }
1179
1180                         if (seb->ec < si->min_ec) {
1181                                 ubi_err("bad si->min_ec (%d), %d found",
1182                                         si->min_ec, seb->ec);
1183                                 goto bad_seb;
1184                         }
1185
1186                         if (seb->ec > si->max_ec) {
1187                                 ubi_err("bad si->max_ec (%d), %d found",
1188                                         si->max_ec, seb->ec);
1189                                 goto bad_seb;
1190                         }
1191
1192                         if (seb->pnum >= ubi->peb_count) {
1193                                 ubi_err("too high PEB number %d, total PEBs %d",
1194                                         seb->pnum, ubi->peb_count);
1195                                 goto bad_seb;
1196                         }
1197
1198                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1199                                 if (seb->lnum >= sv->used_ebs) {
1200                                         ubi_err("bad lnum or used_ebs");
1201                                         goto bad_seb;
1202                                 }
1203                         } else {
1204                                 if (sv->used_ebs != 0) {
1205                                         ubi_err("non-zero used_ebs");
1206                                         goto bad_seb;
1207                                 }
1208                         }
1209
1210                         if (seb->lnum > sv->highest_lnum) {
1211                                 ubi_err("incorrect highest_lnum or lnum");
1212                                 goto bad_seb;
1213                         }
1214                 }
1215
1216                 if (sv->leb_count != leb_count) {
1217                         ubi_err("bad leb_count, %d objects in the tree",
1218                                 leb_count);
1219                         goto bad_sv;
1220                 }
1221
1222                 if (!last_seb)
1223                         continue;
1224
1225                 seb = last_seb;
1226
1227                 if (seb->lnum != sv->highest_lnum) {
1228                         ubi_err("bad highest_lnum");
1229                         goto bad_seb;
1230                 }
1231         }
1232
1233         if (vols_found != si->vols_found) {
1234                 ubi_err("bad si->vols_found %d, should be %d",
1235                         si->vols_found, vols_found);
1236                 goto out;
1237         }
1238
1239         /* Check that scanning information is correct */
1240         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1241                 last_seb = NULL;
1242                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1243                         int vol_type;
1244
1245                         cond_resched();
1246
1247                         last_seb = seb;
1248
1249                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1250                         if (err && err != UBI_IO_BITFLIPS) {
1251                                 ubi_err("VID header is not OK (%d)", err);
1252                                 if (err > 0)
1253                                         err = -EIO;
1254                                 return err;
1255                         }
1256
1257                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1258                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1259                         if (sv->vol_type != vol_type) {
1260                                 ubi_err("bad vol_type");
1261                                 goto bad_vid_hdr;
1262                         }
1263
1264                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1265                                 ubi_err("bad sqnum %llu", seb->sqnum);
1266                                 goto bad_vid_hdr;
1267                         }
1268
1269                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1270                                 ubi_err("bad vol_id %d", sv->vol_id);
1271                                 goto bad_vid_hdr;
1272                         }
1273
1274                         if (sv->compat != vidh->compat) {
1275                                 ubi_err("bad compat %d", vidh->compat);
1276                                 goto bad_vid_hdr;
1277                         }
1278
1279                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1280                                 ubi_err("bad lnum %d", seb->lnum);
1281                                 goto bad_vid_hdr;
1282                         }
1283
1284                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1285                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1286                                 goto bad_vid_hdr;
1287                         }
1288
1289                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1290                                 ubi_err("bad data_pad %d", sv->data_pad);
1291                                 goto bad_vid_hdr;
1292                         }
1293
1294                         if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
1295                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1296                                 goto bad_vid_hdr;
1297                         }
1298                 }
1299
1300                 if (!last_seb)
1301                         continue;
1302
1303                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1304                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1305                         goto bad_vid_hdr;
1306                 }
1307
1308                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1309                         ubi_err("bad last_data_size %d", sv->last_data_size);
1310                         goto bad_vid_hdr;
1311                 }
1312         }
1313
1314         /*
1315          * Make sure that all the physical eraseblocks are in one of the lists
1316          * or trees.
1317          */
1318         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1319         if (!buf)
1320                 return -ENOMEM;
1321
1322         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1323                 err = ubi_io_is_bad(ubi, pnum);
1324                 if (err < 0) {
1325                         kfree(buf);
1326                         return err;
1327                 }
1328                 else if (err)
1329                         buf[pnum] = 1;
1330         }
1331
1332         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1333                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1334                         buf[seb->pnum] = 1;
1335
1336         list_for_each_entry(seb, &si->free, u.list)
1337                 buf[seb->pnum] = 1;
1338
1339         list_for_each_entry(seb, &si->corr, u.list)
1340                 buf[seb->pnum] = 1;
1341
1342         list_for_each_entry(seb, &si->erase, u.list)
1343                 buf[seb->pnum] = 1;
1344
1345         list_for_each_entry(seb, &si->alien, u.list)
1346                 buf[seb->pnum] = 1;
1347
1348         err = 0;
1349         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1350                 if (!buf[pnum]) {
1351                         ubi_err("PEB %d is not referred", pnum);
1352                         err = 1;
1353                 }
1354
1355         kfree(buf);
1356         if (err)
1357                 goto out;
1358         return 0;
1359
1360 bad_seb:
1361         ubi_err("bad scanning information about LEB %d", seb->lnum);
1362         ubi_dbg_dump_seb(seb, 0);
1363         ubi_dbg_dump_sv(sv);
1364         goto out;
1365
1366 bad_sv:
1367         ubi_err("bad scanning information about volume %d", sv->vol_id);
1368         ubi_dbg_dump_sv(sv);
1369         goto out;
1370
1371 bad_vid_hdr:
1372         ubi_err("bad scanning information about volume %d", sv->vol_id);
1373         ubi_dbg_dump_sv(sv);
1374         ubi_dbg_dump_vid_hdr(vidh);
1375
1376 out:
1377         ubi_dbg_dump_stack();
1378         return 1;
1379 }
1380
1381 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */