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 sub-system.
  23  *
  24  * This sub-system 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/slab.h>
  45 #include <linux/crc32.h>
  46 #include <linux/math64.h>
  47 #include "ubi.h"
  48
  49 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  50 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
  51 #else
  52 #define paranoid_check_si(ubi, si) 0
  53 #endif
  54
  55 /* Temporary variables used during scanning */
  56 static struct ubi_ec_hdr *ech;
  57 static struct ubi_vid_hdr *vidh;
  58
  59 /**
  60  * add_to_list - add physical eraseblock to a list.
  61  * @si: scanning information
  62  * @pnum: physical eraseblock number to add
  63  * @ec: erase counter of the physical eraseblock
  64  * @list: the list to add to
  65  *
  66  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  67  * alien lists. Returns zero in case of success and a negative error code in
  68  * case of failure.
  69  */
  70 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  71                        struct list_head *list)
  72 {
  73         struct ubi_scan_leb *seb;
  74
  75         if (list == &si->free) {
  76                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  77                 si->free_peb_count += 1;
  78         } else if (list == &si->erase) {
  79                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  80                 si->erase_peb_count += 1;
  81         } else if (list == &si->corr) {
  82                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  83                 si->corr_peb_count += 1;
  84         } else if (list == &si->alien) {
  85                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  86                 si->alien_peb_count += 1;
  87         } else
  88                 BUG();
  89
  90         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  91         if (!seb)
  92                 return -ENOMEM;
  93
  94         seb->pnum = pnum;
  95         seb->ec = ec;
  96         list_add_tail(&seb->u.list, list);
  97         return 0;
  98 }
  99
 100 /**
 101  * validate_vid_hdr - check volume identifier header.
 102  * @vid_hdr: the volume identifier header to check
 103  * @sv: information about the volume this logical eraseblock belongs to
 104  * @pnum: physical eraseblock number the VID header came from
 105  *
 106  * This function checks that data stored in @vid_hdr is consistent. Returns
 107  * non-zero if an inconsistency was found and zero if not.
 108  *
 109  * Note, UBI does sanity check of everything it reads from the flash media.
 110  * Most of the checks are done in the I/O sub-system. Here we check that the
 111  * information in the VID header is consistent to the information in other VID
 112  * headers of the same volume.
 113  */
 114 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 115                             const struct ubi_scan_volume *sv, int pnum)
 116 {
 117         int vol_type = vid_hdr->vol_type;
 118         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 119         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 120         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 121
 122         if (sv->leb_count != 0) {
 123                 int sv_vol_type;
 124
 125                 /*
 126                  * This is not the first logical eraseblock belonging to this
 127                  * volume. Ensure that the data in its VID header is consistent
 128                  * to the data in previous logical eraseblock headers.
 129                  */
 130
 131                 if (vol_id != sv->vol_id) {
 132                         dbg_err("inconsistent vol_id");
 133                         goto bad;
 134                 }
 135
 136                 if (sv->vol_type == UBI_STATIC_VOLUME)
 137                         sv_vol_type = UBI_VID_STATIC;
 138                 else
 139                         sv_vol_type = UBI_VID_DYNAMIC;
 140
 141                 if (vol_type != sv_vol_type) {
 142                         dbg_err("inconsistent vol_type");
 143                         goto bad;
 144                 }
 145
 146                 if (used_ebs != sv->used_ebs) {
 147                         dbg_err("inconsistent used_ebs");
 148                         goto bad;
 149                 }
 150
 151                 if (data_pad != sv->data_pad) {
 152                         dbg_err("inconsistent data_pad");
 153                         goto bad;
 154                 }
 155         }
 156
 157         return 0;
 158
 159 bad:
 160         ubi_err("inconsistent VID header at PEB %d", pnum);
 161         ubi_dbg_dump_vid_hdr(vid_hdr);
 162         ubi_dbg_dump_sv(sv);
 163         return -EINVAL;
 164 }
 165
 166 /**
 167  * add_volume - add volume to the scanning information.
 168  * @si: scanning information
 169  * @vol_id: ID of the volume to add
 170  * @pnum: physical eraseblock number
 171  * @vid_hdr: volume identifier header
 172  *
 173  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 174  * present in the scanning information, this function does nothing. Otherwise
 175  * it adds corresponding volume to the scanning information. Returns a pointer
 176  * to the scanning volume object in case of success and a negative error code
 177  * in case of failure.
 178  */
 179 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 180                                           int pnum,
 181                                           const struct ubi_vid_hdr *vid_hdr)
 182 {
 183         struct ubi_scan_volume *sv;
 184         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 185
 186         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 187
 188         /* Walk the volume RB-tree to look if this volume is already present */
 189         while (*p) {
 190                 parent = *p;
 191                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 192
 193                 if (vol_id == sv->vol_id)
 194                         return sv;
 195
 196                 if (vol_id > sv->vol_id)
 197                         p = &(*p)->rb_left;
 198                 else
 199                         p = &(*p)->rb_right;
 200         }
 201
 202         /* The volume is absent - add it */
 203         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 204         if (!sv)
 205                 return ERR_PTR(-ENOMEM);
 206
 207         sv->highest_lnum = sv->leb_count = 0;
 208         sv->vol_id = vol_id;
 209         sv->root = RB_ROOT;
 210         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 211         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 212         sv->compat = vid_hdr->compat;
 213         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 214                                                             : UBI_STATIC_VOLUME;
 215         if (vol_id > si->highest_vol_id)
 216                 si->highest_vol_id = vol_id;
 217
 218         rb_link_node(&sv->rb, parent, p);
 219         rb_insert_color(&sv->rb, &si->volumes);
 220         si->vols_found += 1;
 221         dbg_bld("added volume %d", vol_id);
 222         return sv;
 223 }
 224
 225 /**
 226  * compare_lebs - find out which logical eraseblock is newer.
 227  * @ubi: UBI device description object
 228  * @seb: first logical eraseblock to compare
 229  * @pnum: physical eraseblock number of the second logical eraseblock to
 230  * compare
 231  * @vid_hdr: volume identifier header of the second logical eraseblock
 232  *
 233  * This function compares 2 copies of a LEB and informs which one is newer. In
 234  * case of success this function returns a positive value, in case of failure, a
 235  * negative error code is returned. The success return codes use the following
 236  * bits:
 237  *     o bit 0 is cleared: the first PEB (described by @seb) is newer than the
 238  *       second PEB (described by @pnum and @vid_hdr);
 239  *     o bit 0 is set: the second PEB is newer;
 240  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 241  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 242  *     o bit 2 is cleared: the older LEB is not corrupted;
 243  *     o bit 2 is set: the older LEB is corrupted.
 244  */
 245 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 246                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 247 {
 248         void *buf;
 249         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 250         uint32_t data_crc, crc;
 251         struct ubi_vid_hdr *vh = NULL;
 252         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 253
 254         if (sqnum2 == seb->sqnum) {
 255                 /*
 256                  * This must be a really ancient UBI image which has been
 257                  * created before sequence numbers support has been added. At
 258                  * that times we used 32-bit LEB versions stored in logical
 259                  * eraseblocks. That was before UBI got into mainline. We do not
 260                  * support these images anymore. Well, those images will work
 261                  * still work, but only if no unclean reboots happened.
 262                  */
 263                 ubi_err("unsupported on-flash UBI format\n");
 264                 return -EINVAL;
 265         }
 266
 267         /* Obviously the LEB with lower sequence counter is older */
 268         second_is_newer = !!(sqnum2 > seb->sqnum);
 269
 270         /*
 271          * Now we know which copy is newer. If the copy flag of the PEB with
 272          * newer version is not set, then we just return, otherwise we have to
 273          * check data CRC. For the second PEB we already have the VID header,
 274          * for the first one - we'll need to re-read it from flash.
 275          *
 276          * Note: this may be optimized so that we wouldn't read twice.
 277          */
 278
 279         if (second_is_newer) {
 280                 if (!vid_hdr->copy_flag) {
 281                         /* It is not a copy, so it is newer */
 282                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 283                                 pnum);
 284                         return 1;
 285                 }
 286         } else {
 287                 pnum = seb->pnum;
 288
 289                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 290                 if (!vh)
 291                         return -ENOMEM;
 292
 293                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 294                 if (err) {
 295                         if (err == UBI_IO_BITFLIPS)
 296                                 bitflips = 1;
 297                         else {
 298                                 dbg_err("VID of PEB %d header is bad, but it "
 299                                         "was OK earlier", pnum);
 300                                 if (err > 0)
 301                                         err = -EIO;
 302
 303                                 goto out_free_vidh;
 304                         }
 305                 }
 306
 307                 if (!vh->copy_flag) {
 308                         /* It is not a copy, so it is newer */
 309                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 310                                 pnum);
 311                         err = bitflips << 1;
 312                         goto out_free_vidh;
 313                 }
 314
 315                 vid_hdr = vh;
 316         }
 317
 318         /* Read the data of the copy and check the CRC */
 319
 320         len = be32_to_cpu(vid_hdr->data_size);
 321         buf = vmalloc(len);
 322         if (!buf) {
 323                 err = -ENOMEM;
 324                 goto out_free_vidh;
 325         }
 326
 327         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 328         if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
 329                 goto out_free_buf;
 330
 331         data_crc = be32_to_cpu(vid_hdr->data_crc);
 332         crc = crc32(UBI_CRC32_INIT, buf, len);
 333         if (crc != data_crc) {
 334                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 335                         pnum, crc, data_crc);
 336                 corrupted = 1;
 337                 bitflips = 0;
 338                 second_is_newer = !second_is_newer;
 339         } else {
 340                 dbg_bld("PEB %d CRC is OK", pnum);
 341                 bitflips = !!err;
 342         }
 343
 344         vfree(buf);
 345         ubi_free_vid_hdr(ubi, vh);
 346
 347         if (second_is_newer)
 348                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 349         else
 350                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 351
 352         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 353
 354 out_free_buf:
 355         vfree(buf);
 356 out_free_vidh:
 357         ubi_free_vid_hdr(ubi, vh);
 358         return err;
 359 }
 360
 361 /**
 362  * ubi_scan_add_used - add physical eraseblock to the scanning information.
 363  * @ubi: UBI device description object
 364  * @si: scanning information
 365  * @pnum: the physical eraseblock number
 366  * @ec: erase counter
 367  * @vid_hdr: the volume identifier header
 368  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 369  *
 370  * This function adds information about a used physical eraseblock to the
 371  * 'used' tree of the corresponding volume. The function is rather complex
 372  * because it has to handle cases when this is not the first physical
 373  * eraseblock belonging to the same logical eraseblock, and the newer one has
 374  * to be picked, while the older one has to be dropped. This function returns
 375  * zero in case of success and a negative error code in case of failure.
 376  */
 377 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 378                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 379                       int bitflips)
 380 {
 381         int err, vol_id, lnum;
 382         unsigned long long sqnum;
 383         struct ubi_scan_volume *sv;
 384         struct ubi_scan_leb *seb;
 385         struct rb_node **p, *parent = NULL;
 386
 387         vol_id = be32_to_cpu(vid_hdr->vol_id);
 388         lnum = be32_to_cpu(vid_hdr->lnum);
 389         sqnum = be64_to_cpu(vid_hdr->sqnum);
 390
 391         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
 392                 pnum, vol_id, lnum, ec, sqnum, bitflips);
 393
 394         sv = add_volume(si, vol_id, pnum, vid_hdr);
 395         if (IS_ERR(sv))
 396                 return PTR_ERR(sv);
 397
 398         if (si->max_sqnum < sqnum)
 399                 si->max_sqnum = sqnum;
 400
 401         /*
 402          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 403          * if this is the first instance of this logical eraseblock or not.
 404          */
 405         p = &sv->root.rb_node;
 406         while (*p) {
 407                 int cmp_res;
 408
 409                 parent = *p;
 410                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 411                 if (lnum != seb->lnum) {
 412                         if (lnum < seb->lnum)
 413                                 p = &(*p)->rb_left;
 414                         else
 415                                 p = &(*p)->rb_right;
 416                         continue;
 417                 }
 418
 419                 /*
 420                  * There is already a physical eraseblock describing the same
 421                  * logical eraseblock present.
 422                  */
 423
 424                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 425                         "EC %d", seb->pnum, seb->sqnum, seb->ec);
 426
 427                 /*
 428                  * Make sure that the logical eraseblocks have different
 429                  * sequence numbers. Otherwise the image is bad.
 430                  *
 431                  * However, if the sequence number is zero, we assume it must
 432                  * be an ancient UBI image from the era when UBI did not have
 433                  * sequence numbers. We still can attach these images, unless
 434                  * there is a need to distinguish between old and new
 435                  * eraseblocks, in which case we'll refuse the image in
 436                  * 'compare_lebs()'. In other words, we attach old clean
 437                  * images, but refuse attaching old images with duplicated
 438                  * logical eraseblocks because there was an unclean reboot.
 439                  */
 440                 if (seb->sqnum == sqnum && sqnum != 0) {
 441                         ubi_err("two LEBs with same sequence number %llu",
 442                                 sqnum);
 443                         ubi_dbg_dump_seb(seb, 0);
 444                         ubi_dbg_dump_vid_hdr(vid_hdr);
 445                         return -EINVAL;
 446                 }
 447
 448                 /*
 449                  * Now we have to drop the older one and preserve the newer
 450                  * one.
 451                  */
 452                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 453                 if (cmp_res < 0)
 454                         return cmp_res;
 455
 456                 if (cmp_res & 1) {
 457                         /*
 458                          * This logical eraseblock is newer than the one
 459                          * found earlier.
 460                          */
 461                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 462                         if (err)
 463                                 return err;
 464
 465                         if (cmp_res & 4)
 466                                 err = add_to_list(si, seb->pnum, seb->ec,
 467                                                   &si->corr);
 468                         else
 469                                 err = add_to_list(si, seb->pnum, seb->ec,
 470                                                   &si->erase);
 471                         if (err)
 472                                 return err;
 473
 474                         seb->ec = ec;
 475                         seb->pnum = pnum;
 476                         seb->scrub = ((cmp_res & 2) || bitflips);
 477                         seb->sqnum = sqnum;
 478
 479                         if (sv->highest_lnum == lnum)
 480                                 sv->last_data_size =
 481                                         be32_to_cpu(vid_hdr->data_size);
 482
 483                         return 0;
 484                 } else {
 485                         /*
 486                          * This logical eraseblock is older than the one found
 487                          * previously.
 488                          */
 489                         if (cmp_res & 4)
 490                                 return add_to_list(si, pnum, ec, &si->corr);
 491                         else
 492                                 return add_to_list(si, pnum, ec, &si->erase);
 493                 }
 494         }
 495
 496         /*
 497          * We've met this logical eraseblock for the first time, add it to the
 498          * scanning information.
 499          */
 500
 501         err = validate_vid_hdr(vid_hdr, sv, pnum);
 502         if (err)
 503                 return err;
 504
 505         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 506         if (!seb)
 507                 return -ENOMEM;
 508
 509         seb->ec = ec;
 510         seb->pnum = pnum;
 511         seb->lnum = lnum;
 512         seb->sqnum = sqnum;
 513         seb->scrub = bitflips;
 514
 515         if (sv->highest_lnum <= lnum) {
 516                 sv->highest_lnum = lnum;
 517                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 518         }
 519
 520         sv->leb_count += 1;
 521         rb_link_node(&seb->u.rb, parent, p);
 522         rb_insert_color(&seb->u.rb, &sv->root);
 523         si->used_peb_count += 1;
 524         return 0;
 525 }
 526
 527 /**
 528  * ubi_scan_find_sv - find volume in the scanning information.
 529  * @si: scanning information
 530  * @vol_id: the requested volume ID
 531  *
 532  * This function returns a pointer to the volume description or %NULL if there
 533  * are no data about this volume in the scanning information.
 534  */
 535 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 536                                          int vol_id)
 537 {
 538         struct ubi_scan_volume *sv;
 539         struct rb_node *p = si->volumes.rb_node;
 540
 541         while (p) {
 542                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 543
 544                 if (vol_id == sv->vol_id)
 545                         return sv;
 546
 547                 if (vol_id > sv->vol_id)
 548                         p = p->rb_left;
 549                 else
 550                         p = p->rb_right;
 551         }
 552
 553         return NULL;
 554 }
 555
 556 /**
 557  * ubi_scan_find_seb - find LEB in the volume scanning information.
 558  * @sv: a pointer to the volume scanning information
 559  * @lnum: the requested logical eraseblock
 560  *
 561  * This function returns a pointer to the scanning logical eraseblock or %NULL
 562  * if there are no data about it in the scanning volume information.
 563  */
 564 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 565                                        int lnum)
 566 {
 567         struct ubi_scan_leb *seb;
 568         struct rb_node *p = sv->root.rb_node;
 569
 570         while (p) {
 571                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 572
 573                 if (lnum == seb->lnum)
 574                         return seb;
 575
 576                 if (lnum > seb->lnum)
 577                         p = p->rb_left;
 578                 else
 579                         p = p->rb_right;
 580         }
 581
 582         return NULL;
 583 }
 584
 585 /**
 586  * ubi_scan_rm_volume - delete scanning information about a volume.
 587  * @si: scanning information
 588  * @sv: the volume scanning information to delete
 589  */
 590 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 591 {
 592         struct rb_node *rb;
 593         struct ubi_scan_leb *seb;
 594
 595         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 596
 597         while ((rb = rb_first(&sv->root))) {
 598                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 599                 rb_erase(&seb->u.rb, &sv->root);
 600                 list_add_tail(&seb->u.list, &si->erase);
 601         }
 602
 603         rb_erase(&sv->rb, &si->volumes);
 604         kfree(sv);
 605         si->vols_found -= 1;
 606 }
 607
 608 /**
 609  * ubi_scan_erase_peb - erase a physical eraseblock.
 610  * @ubi: UBI device description object
 611  * @si: scanning information
 612  * @pnum: physical eraseblock number to erase;
 613  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 614  *
 615  * This function erases physical eraseblock 'pnum', and writes the erase
 616  * counter header to it. This function should only be used on UBI device
 617  * initialization stages, when the EBA sub-system had not been yet initialized.
 618  * This function returns zero in case of success and a negative error code in
 619  * case of failure.
 620  */
 621 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 622                        int pnum, int ec)
 623 {
 624         int err;
 625         struct ubi_ec_hdr *ec_hdr;
 626
 627         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 628                 /*
 629                  * Erase counter overflow. Upgrade UBI and use 64-bit
 630                  * erase counters internally.
 631                  */
 632                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 633                 return -EINVAL;
 634         }
 635
 636         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 637         if (!ec_hdr)
 638                 return -ENOMEM;
 639
 640         ec_hdr->ec = cpu_to_be64(ec);
 641
 642         err = ubi_io_sync_erase(ubi, pnum, 0);
 643         if (err < 0)
 644                 goto out_free;
 645
 646         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 647
 648 out_free:
 649         kfree(ec_hdr);
 650         return err;
 651 }
 652
 653 /**
 654  * ubi_scan_get_free_peb - get a free physical eraseblock.
 655  * @ubi: UBI device description object
 656  * @si: scanning information
 657  *
 658  * This function returns a free physical eraseblock. It is supposed to be
 659  * called on the UBI initialization stages when the wear-leveling sub-system is
 660  * not initialized yet. This function picks a physical eraseblocks from one of
 661  * the lists, writes the EC header if it is needed, and removes it from the
 662  * list.
 663  *
 664  * This function returns scanning physical eraseblock information in case of
 665  * success and an error code in case of failure.
 666  */
 667 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 668                                            struct ubi_scan_info *si)
 669 {
 670         int err = 0, i;
 671         struct ubi_scan_leb *seb;
 672
 673         if (!list_empty(&si->free)) {
 674                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 675                 list_del(&seb->u.list);
 676                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 677                 return seb;
 678         }
 679
 680         for (i = 0; i < 2; i++) {
 681                 struct list_head *head;
 682                 struct ubi_scan_leb *tmp_seb;
 683
 684                 if (i == 0)
 685                         head = &si->erase;
 686                 else
 687                         head = &si->corr;
 688
 689                 /*
 690                  * We try to erase the first physical eraseblock from the @head
 691                  * list and pick it if we succeed, or try to erase the
 692                  * next one if not. And so forth. We don't want to take care
 693                  * about bad eraseblocks here - they'll be handled later.
 694                  */
 695                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 696                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 697                                 seb->ec = si->mean_ec;
 698
 699                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 700                         if (err)
 701                                 continue;
 702
 703                         seb->ec += 1;
 704                         list_del(&seb->u.list);
 705                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 706                         return seb;
 707                 }
 708         }
 709
 710         ubi_err("no eraseblocks found");
 711         return ERR_PTR(-ENOSPC);
 712 }
 713
 714 /**
 715  * process_eb - read, check UBI headers, and add them to scanning information.
 716  * @ubi: UBI device description object
 717  * @si: scanning information
 718  * @pnum: the physical eraseblock number
 719  *
 720  * This function returns a zero if the physical eraseblock was successfully
 721  * handled and a negative error code in case of failure.
 722  */
 723 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 724                       int pnum)
 725 {
 726         long long uninitialized_var(ec);
 727         int err, bitflips = 0, vol_id, ec_corr = 0;
 728
 729         dbg_bld("scan PEB %d", pnum);
 730
 731         /* Skip bad physical eraseblocks */
 732         err = ubi_io_is_bad(ubi, pnum);
 733         if (err < 0)
 734                 return err;
 735         else if (err) {
 736                 /*
 737                  * FIXME: this is actually duty of the I/O sub-system to
 738                  * initialize this, but MTD does not provide enough
 739                  * information.
 740                  */
 741                 si->bad_peb_count += 1;
 742                 return 0;
 743         }
 744
 745         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 746         if (err < 0)
 747                 return err;
 748         else if (err == UBI_IO_BITFLIPS)
 749                 bitflips = 1;
 750         else if (err == UBI_IO_PEB_EMPTY)
 751                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 752         else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) {
 753                 /*
 754                  * We have to also look at the VID header, possibly it is not
 755                  * corrupted. Set %bitflips flag in order to make this PEB be
 756                  * moved and EC be re-created.
 757                  */
 758                 ec_corr = err;
 759                 ec = UBI_SCAN_UNKNOWN_EC;
 760                 bitflips = 1;
 761         }
 762
 763         if (!ec_corr) {
 764                 int image_seq;
 765
 766                 /* Make sure UBI version is OK */
 767                 if (ech->version != UBI_VERSION) {
 768                         ubi_err("this UBI version is %d, image version is %d",
 769                                 UBI_VERSION, (int)ech->version);
 770                         return -EINVAL;
 771                 }
 772
 773                 ec = be64_to_cpu(ech->ec);
 774                 if (ec > UBI_MAX_ERASECOUNTER) {
 775                         /*
 776                          * Erase counter overflow. The EC headers have 64 bits
 777                          * reserved, but we anyway make use of only 31 bit
 778                          * values, as this seems to be enough for any existing
 779                          * flash. Upgrade UBI and use 64-bit erase counters
 780                          * internally.
 781                          */
 782                         ubi_err("erase counter overflow, max is %d",
 783                                 UBI_MAX_ERASECOUNTER);
 784                         ubi_dbg_dump_ec_hdr(ech);
 785                         return -EINVAL;
 786                 }
 787
 788                 /*
 789                  * Make sure that all PEBs have the same image sequence number.
 790                  * This allows us to detect situations when users flash UBI
 791                  * images incorrectly, so that the flash has the new UBI image
 792                  * and leftovers from the old one. This feature was added
 793                  * relatively recently, and the sequence number was always
 794                  * zero, because old UBI implementations always set it to zero.
 795                  * For this reasons, we do not panic if some PEBs have zero
 796                  * sequence number, while other PEBs have non-zero sequence
 797                  * number.
 798                  */
 799                 image_seq = be32_to_cpu(ech->image_seq);
 800                 if (!ubi->image_seq && image_seq)
 801                         ubi->image_seq = image_seq;
 802                 if (ubi->image_seq && image_seq &&
 803                     ubi->image_seq != image_seq) {
 804                         ubi_err("bad image sequence number %d in PEB %d, "
 805                                 "expected %d", image_seq, pnum, ubi->image_seq);
 806                         ubi_dbg_dump_ec_hdr(ech);
 807                         return -EINVAL;
 808                 }
 809         }
 810
 811         /* OK, we've done with the EC header, let's look at the VID header */
 812
 813         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 814         if (err < 0)
 815                 return err;
 816         else if (err == UBI_IO_BITFLIPS)
 817                 bitflips = 1;
 818         else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR ||
 819                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 820                 /* VID header is corrupted */
 821                 if (err == UBI_IO_BAD_HDR_READ ||
 822                     ec_corr == UBI_IO_BAD_HDR_READ)
 823                         si->read_err_count += 1;
 824                 err = add_to_list(si, pnum, ec, &si->corr);
 825                 if (err)
 826                         return err;
 827                 goto adjust_mean_ec;
 828         } else if (err == UBI_IO_PEB_FREE) {
 829                 /* No VID header - the physical eraseblock is free */
 830                 err = add_to_list(si, pnum, ec, &si->free);
 831                 if (err)
 832                         return err;
 833                 goto adjust_mean_ec;
 834         }
 835
 836         vol_id = be32_to_cpu(vidh->vol_id);
 837         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 838                 int lnum = be32_to_cpu(vidh->lnum);
 839
 840                 /* Unsupported internal volume */
 841                 switch (vidh->compat) {
 842                 case UBI_COMPAT_DELETE:
 843                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 844                                 " found, remove it", vol_id, lnum);
 845                         err = add_to_list(si, pnum, ec, &si->corr);
 846                         if (err)
 847                                 return err;
 848                         break;
 849
 850                 case UBI_COMPAT_RO:
 851                         ubi_msg("read-only compatible internal volume %d:%d"
 852                                 " found, switch to read-only mode",
 853                                 vol_id, lnum);
 854                         ubi->ro_mode = 1;
 855                         break;
 856
 857                 case UBI_COMPAT_PRESERVE:
 858                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 859                                 " found", vol_id, lnum);
 860                         err = add_to_list(si, pnum, ec, &si->alien);
 861                         if (err)
 862                                 return err;
 863                         return 0;
 864
 865                 case UBI_COMPAT_REJECT:
 866                         ubi_err("incompatible internal volume %d:%d found",
 867                                 vol_id, lnum);
 868                         return -EINVAL;
 869                 }
 870         }
 871
 872         if (ec_corr)
 873                 ubi_warn("valid VID header but corrupted EC header at PEB %d",
 874                          pnum);
 875         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 876         if (err)
 877                 return err;
 878
 879 adjust_mean_ec:
 880         if (!ec_corr) {
 881                 si->ec_sum += ec;
 882                 si->ec_count += 1;
 883                 if (ec > si->max_ec)
 884                         si->max_ec = ec;
 885                 if (ec < si->min_ec)
 886                         si->min_ec = ec;
 887         }
 888
 889         return 0;
 890 }
 891
 892 /**
 893  * check_what_we_have - check what PEB were found by scanning.
 894  * @ubi: UBI device description object
 895  * @si: scanning information
 896  *
 897  * This is a helper function which takes a look what PEBs were found by
 898  * scanning, and decides whether the flash is empty and should be formatted and
 899  * whether there are too many corrupted PEBs and we should not attach this
 900  * MTD device. Returns zero if we should proceed with attaching the MTD device,
 901  * and %-EINVAL if we should not.
 902  */
 903 static int check_what_we_have(const struct ubi_device *ubi,
 904                               struct ubi_scan_info *si)
 905 {
 906         struct ubi_scan_leb *seb;
 907         int max_corr;
 908
 909         max_corr = ubi->peb_count - si->bad_peb_count - si->alien_peb_count;
 910         max_corr = max_corr / 20 ?: 8;
 911
 912         /*
 913          * Few corrupted PEBs are not a problem and may be just a result of
 914          * unclean reboots. However, many of them may indicate some problems
 915          * with the flash HW or driver.
 916          */
 917         if (si->corr_peb_count >= 8) {
 918                 ubi_warn("%d PEBs are corrupted", si->corr_peb_count);
 919                 printk(KERN_WARNING "corrupted PEBs are:");
 920                 list_for_each_entry(seb, &si->corr, u.list)
 921                         printk(KERN_CONT " %d", seb->pnum);
 922                 printk(KERN_CONT "\n");
 923
 924                 /*
 925                  * If too many PEBs are corrupted, we refuse attaching,
 926                  * otherwise, only print a warning.
 927                  */
 928                 if (si->corr_peb_count >= max_corr) {
 929                         ubi_err("too many corrupted PEBs, refusing this device");
 930                         return -EINVAL;
 931                 }
 932         }
 933
 934         if (si->free_peb_count + si->used_peb_count +
 935             si->alien_peb_count == 0) {
 936                 /* No UBI-formatted eraseblocks were found */
 937                 if (si->corr_peb_count == si->read_err_count &&
 938                     si->corr_peb_count < 8) {
 939                         /* No or just few corrupted PEBs, and all of them had a
 940                          * read error. We assume that those are bad PEBs, which
 941                          * were just not marked as bad so far.
 942                          *
 943                          * This piece of code basically tries to distinguish
 944                          * between the following 2 situations:
 945                          *
 946                          * 1. Flash is empty, but there are few bad PEBs, which
 947                          *    are not marked as bad so far, and which were read
 948                          *    with error. We want to go ahead and format this
 949                          *    flash. While formating, the faulty PEBs will
 950                          *    probably be marked as bad.
 951                          *
 952                          * 2. Flash probably contains non-UBI data and we do
 953                          * not want to format it and destroy possibly needed
 954                          * data (e.g., consider the case when the bootloader
 955                          * MTD partition was accidentally fed to UBI).
 956                          */
 957                         si->is_empty = 1;
 958                         ubi_msg("empty MTD device detected");
 959                 } else {
 960                         ubi_err("MTD device possibly contains non-UBI data, "
 961                                 "refusing it");
 962                         return -EINVAL;
 963                 }
 964         }
 965
 966         if (si->corr_peb_count >= 0)
 967                 ubi_msg("corrupted PEBs will be formatted");
 968         return 0;
 969 }
 970
 971 /**
 972  * ubi_scan - scan an MTD device.
 973  * @ubi: UBI device description object
 974  *
 975  * This function does full scanning of an MTD device and returns complete
 976  * information about it. In case of failure, an error code is returned.
 977  */
 978 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 979 {
 980         int err, pnum;
 981         struct rb_node *rb1, *rb2;
 982         struct ubi_scan_volume *sv;
 983         struct ubi_scan_leb *seb;
 984         struct ubi_scan_info *si;
 985
 986         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 987         if (!si)
 988                 return ERR_PTR(-ENOMEM);
 989
 990         INIT_LIST_HEAD(&si->corr);
 991         INIT_LIST_HEAD(&si->free);
 992         INIT_LIST_HEAD(&si->erase);
 993         INIT_LIST_HEAD(&si->alien);
 994         si->volumes = RB_ROOT;
 995
 996         err = -ENOMEM;
 997         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 998         if (!ech)
 999                 goto out_si;
1000
1001         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1002         if (!vidh)
1003                 goto out_ech;
1004
1005         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1006                 cond_resched();
1007
1008                 dbg_gen("process PEB %d", pnum);
1009                 err = process_eb(ubi, si, pnum);
1010                 if (err < 0)
1011                         goto out_vidh;
1012         }
1013
1014         dbg_msg("scanning is finished");
1015
1016         /* Calculate mean erase counter */
1017         if (si->ec_count)
1018                 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
1019
1020         err = check_what_we_have(ubi, si);
1021         if (err)
1022                 goto out_vidh;
1023
1024         /*
1025          * In case of unknown erase counter we use the mean erase counter
1026          * value.
1027          */
1028         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1029                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1030                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1031                                 seb->ec = si->mean_ec;
1032         }
1033
1034         list_for_each_entry(seb, &si->free, u.list) {
1035                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1036                         seb->ec = si->mean_ec;
1037         }
1038
1039         list_for_each_entry(seb, &si->corr, u.list)
1040                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1041                         seb->ec = si->mean_ec;
1042
1043         list_for_each_entry(seb, &si->erase, u.list)
1044                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1045                         seb->ec = si->mean_ec;
1046
1047         err = paranoid_check_si(ubi, si);
1048         if (err)
1049                 goto out_vidh;
1050
1051         ubi_free_vid_hdr(ubi, vidh);
1052         kfree(ech);
1053
1054         return si;
1055
1056 out_vidh:
1057         ubi_free_vid_hdr(ubi, vidh);
1058 out_ech:
1059         kfree(ech);
1060 out_si:
1061         ubi_scan_destroy_si(si);
1062         return ERR_PTR(err);
1063 }
1064
1065 /**
1066  * destroy_sv - free the scanning volume information
1067  * @sv: scanning volume information
1068  *
1069  * This function destroys the volume RB-tree (@sv->root) and the scanning
1070  * volume information.
1071  */
1072 static void destroy_sv(struct ubi_scan_volume *sv)
1073 {
1074         struct ubi_scan_leb *seb;
1075         struct rb_node *this = sv->root.rb_node;
1076
1077         while (this) {
1078                 if (this->rb_left)
1079                         this = this->rb_left;
1080                 else if (this->rb_right)
1081                         this = this->rb_right;
1082                 else {
1083                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1084                         this = rb_parent(this);
1085                         if (this) {
1086                                 if (this->rb_left == &seb->u.rb)
1087                                         this->rb_left = NULL;
1088                                 else
1089                                         this->rb_right = NULL;
1090                         }
1091
1092                         kfree(seb);
1093                 }
1094         }
1095         kfree(sv);
1096 }
1097
1098 /**
1099  * ubi_scan_destroy_si - destroy scanning information.
1100  * @si: scanning information
1101  */
1102 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1103 {
1104         struct ubi_scan_leb *seb, *seb_tmp;
1105         struct ubi_scan_volume *sv;
1106         struct rb_node *rb;
1107
1108         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1109                 list_del(&seb->u.list);
1110                 kfree(seb);
1111         }
1112         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1113                 list_del(&seb->u.list);
1114                 kfree(seb);
1115         }
1116         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1117                 list_del(&seb->u.list);
1118                 kfree(seb);
1119         }
1120         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1121                 list_del(&seb->u.list);
1122                 kfree(seb);
1123         }
1124
1125         /* Destroy the volume RB-tree */
1126         rb = si->volumes.rb_node;
1127         while (rb) {
1128                 if (rb->rb_left)
1129                         rb = rb->rb_left;
1130                 else if (rb->rb_right)
1131                         rb = rb->rb_right;
1132                 else {
1133                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1134
1135                         rb = rb_parent(rb);
1136                         if (rb) {
1137                                 if (rb->rb_left == &sv->rb)
1138                                         rb->rb_left = NULL;
1139                                 else
1140                                         rb->rb_right = NULL;
1141                         }
1142
1143                         destroy_sv(sv);
1144                 }
1145         }
1146
1147         kfree(si);
1148 }
1149
1150 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1151
1152 /**
1153  * paranoid_check_si - check the scanning information.
1154  * @ubi: UBI device description object
1155  * @si: scanning information
1156  *
1157  * This function returns zero if the scanning information is all right, and a
1158  * negative error code if not or if an error occurred.
1159  */
1160 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1161 {
1162         int pnum, err, vols_found = 0;
1163         struct rb_node *rb1, *rb2;
1164         struct ubi_scan_volume *sv;
1165         struct ubi_scan_leb *seb, *last_seb;
1166         uint8_t *buf;
1167
1168         /*
1169          * At first, check that scanning information is OK.
1170          */
1171         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1172                 int leb_count = 0;
1173
1174                 cond_resched();
1175
1176                 vols_found += 1;
1177
1178                 if (si->is_empty) {
1179                         ubi_err("bad is_empty flag");
1180                         goto bad_sv;
1181                 }
1182
1183                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1184                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1185                     sv->data_pad < 0 || sv->last_data_size < 0) {
1186                         ubi_err("negative values");
1187                         goto bad_sv;
1188                 }
1189
1190                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1191                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1192                         ubi_err("bad vol_id");
1193                         goto bad_sv;
1194                 }
1195
1196                 if (sv->vol_id > si->highest_vol_id) {
1197                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1198                                 si->highest_vol_id, sv->vol_id);
1199                         goto out;
1200                 }
1201
1202                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1203                     sv->vol_type != UBI_STATIC_VOLUME) {
1204                         ubi_err("bad vol_type");
1205                         goto bad_sv;
1206                 }
1207
1208                 if (sv->data_pad > ubi->leb_size / 2) {
1209                         ubi_err("bad data_pad");
1210                         goto bad_sv;
1211                 }
1212
1213                 last_seb = NULL;
1214                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1215                         cond_resched();
1216
1217                         last_seb = seb;
1218                         leb_count += 1;
1219
1220                         if (seb->pnum < 0 || seb->ec < 0) {
1221                                 ubi_err("negative values");
1222                                 goto bad_seb;
1223                         }
1224
1225                         if (seb->ec < si->min_ec) {
1226                                 ubi_err("bad si->min_ec (%d), %d found",
1227                                         si->min_ec, seb->ec);
1228                                 goto bad_seb;
1229                         }
1230
1231                         if (seb->ec > si->max_ec) {
1232                                 ubi_err("bad si->max_ec (%d), %d found",
1233                                         si->max_ec, seb->ec);
1234                                 goto bad_seb;
1235                         }
1236
1237                         if (seb->pnum >= ubi->peb_count) {
1238                                 ubi_err("too high PEB number %d, total PEBs %d",
1239                                         seb->pnum, ubi->peb_count);
1240                                 goto bad_seb;
1241                         }
1242
1243                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1244                                 if (seb->lnum >= sv->used_ebs) {
1245                                         ubi_err("bad lnum or used_ebs");
1246                                         goto bad_seb;
1247                                 }
1248                         } else {
1249                                 if (sv->used_ebs != 0) {
1250                                         ubi_err("non-zero used_ebs");
1251                                         goto bad_seb;
1252                                 }
1253                         }
1254
1255                         if (seb->lnum > sv->highest_lnum) {
1256                                 ubi_err("incorrect highest_lnum or lnum");
1257                                 goto bad_seb;
1258                         }
1259                 }
1260
1261                 if (sv->leb_count != leb_count) {
1262                         ubi_err("bad leb_count, %d objects in the tree",
1263                                 leb_count);
1264                         goto bad_sv;
1265                 }
1266
1267                 if (!last_seb)
1268                         continue;
1269
1270                 seb = last_seb;
1271
1272                 if (seb->lnum != sv->highest_lnum) {
1273                         ubi_err("bad highest_lnum");
1274                         goto bad_seb;
1275                 }
1276         }
1277
1278         if (vols_found != si->vols_found) {
1279                 ubi_err("bad si->vols_found %d, should be %d",
1280                         si->vols_found, vols_found);
1281                 goto out;
1282         }
1283
1284         /* Check that scanning information is correct */
1285         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1286                 last_seb = NULL;
1287                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1288                         int vol_type;
1289
1290                         cond_resched();
1291
1292                         last_seb = seb;
1293
1294                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1295                         if (err && err != UBI_IO_BITFLIPS) {
1296                                 ubi_err("VID header is not OK (%d)", err);
1297                                 if (err > 0)
1298                                         err = -EIO;
1299                                 return err;
1300                         }
1301
1302                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1303                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1304                         if (sv->vol_type != vol_type) {
1305                                 ubi_err("bad vol_type");
1306                                 goto bad_vid_hdr;
1307                         }
1308
1309                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1310                                 ubi_err("bad sqnum %llu", seb->sqnum);
1311                                 goto bad_vid_hdr;
1312                         }
1313
1314                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1315                                 ubi_err("bad vol_id %d", sv->vol_id);
1316                                 goto bad_vid_hdr;
1317                         }
1318
1319                         if (sv->compat != vidh->compat) {
1320                                 ubi_err("bad compat %d", vidh->compat);
1321                                 goto bad_vid_hdr;
1322                         }
1323
1324                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1325                                 ubi_err("bad lnum %d", seb->lnum);
1326                                 goto bad_vid_hdr;
1327                         }
1328
1329                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1330                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1331                                 goto bad_vid_hdr;
1332                         }
1333
1334                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1335                                 ubi_err("bad data_pad %d", sv->data_pad);
1336                                 goto bad_vid_hdr;
1337                         }
1338                 }
1339
1340                 if (!last_seb)
1341                         continue;
1342
1343                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1344                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1345                         goto bad_vid_hdr;
1346                 }
1347
1348                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1349                         ubi_err("bad last_data_size %d", sv->last_data_size);
1350                         goto bad_vid_hdr;
1351                 }
1352         }
1353
1354         /*
1355          * Make sure that all the physical eraseblocks are in one of the lists
1356          * or trees.
1357          */
1358         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1359         if (!buf)
1360                 return -ENOMEM;
1361
1362         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1363                 err = ubi_io_is_bad(ubi, pnum);
1364                 if (err < 0) {
1365                         kfree(buf);
1366                         return err;
1367                 } else if (err)
1368                         buf[pnum] = 1;
1369         }
1370
1371         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1372                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1373                         buf[seb->pnum] = 1;
1374
1375         list_for_each_entry(seb, &si->free, u.list)
1376                 buf[seb->pnum] = 1;
1377
1378         list_for_each_entry(seb, &si->corr, u.list)
1379                 buf[seb->pnum] = 1;
1380
1381         list_for_each_entry(seb, &si->erase, u.list)
1382                 buf[seb->pnum] = 1;
1383
1384         list_for_each_entry(seb, &si->alien, u.list)
1385                 buf[seb->pnum] = 1;
1386
1387         err = 0;
1388         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1389                 if (!buf[pnum]) {
1390                         ubi_err("PEB %d is not referred", pnum);
1391                         err = 1;
1392                 }
1393
1394         kfree(buf);
1395         if (err)
1396                 goto out;
1397         return 0;
1398
1399 bad_seb:
1400         ubi_err("bad scanning information about LEB %d", seb->lnum);
1401         ubi_dbg_dump_seb(seb, 0);
1402         ubi_dbg_dump_sv(sv);
1403         goto out;
1404
1405 bad_sv:
1406         ubi_err("bad scanning information about volume %d", sv->vol_id);
1407         ubi_dbg_dump_sv(sv);
1408         goto out;
1409
1410 bad_vid_hdr:
1411         ubi_err("bad scanning information about volume %d", sv->vol_id);
1412         ubi_dbg_dump_sv(sv);
1413         ubi_dbg_dump_vid_hdr(vidh);
1414
1415 out:
1416         ubi_dbg_dump_stack();
1417         return -EINVAL;
1418 }
1419
1420 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */