err.no Git - linux-2.6/blob - drivers/mtd/ubi/scan.c

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Author: Artem Bityutskiy (Битюцкий Артём)
  19  */
  20
  21 /*
  22  * UBI scanning unit.
  23  *
  24  * This unit is responsible for scanning the flash media, checking UBI
  25  * headers and providing complete information about the UBI flash image.
  26  *
  27  * The scanning information is represented by a &struct ubi_scan_info' object.
  28  * Information about found volumes is represented by &struct ubi_scan_volume
  29  * objects which are kept in volume RB-tree with root at the @volumes field.
  30  * The RB-tree is indexed by the volume ID.
  31  *
  32  * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
  33  * These objects are kept in per-volume RB-trees with the root at the
  34  * corresponding &struct ubi_scan_volume object. To put it differently, we keep
  35  * an RB-tree of per-volume objects and each of these objects is the root of
  36  * RB-tree of per-eraseblock objects.
  37  *
  38  * Corrupted physical eraseblocks are put to the @corr list, free physical
  39  * eraseblocks are put to the @free list and the physical eraseblock to be
  40  * erased are put to the @erase list.
  41  */
  42
  43 #include <linux/err.h>
  44 #include <linux/crc32.h>
  45 #include "ubi.h"
  46
  47 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  48 static int paranoid_check_si(const struct ubi_device *ubi,
  49                              struct ubi_scan_info *si);
  50 #else
  51 #define paranoid_check_si(ubi, si) 0
  52 #endif
  53
  54 /* Temporary variables used during scanning */
  55 static struct ubi_ec_hdr *ech;
  56 static struct ubi_vid_hdr *vidh;
  57
  58 /**
  59  * add_to_list - add physical eraseblock to a list.
  60  * @si: scanning information
  61  * @pnum: physical eraseblock number to add
  62  * @ec: erase counter of the physical eraseblock
  63  * @list: the list to add to
  64  *
  65  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  66  * alien lists. Returns zero in case of success and a negative error code in
  67  * case of failure.
  68  */
  69 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  70                        struct list_head *list)
  71 {
  72         struct ubi_scan_leb *seb;
  73
  74         if (list == &si->free)
  75                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  76         else if (list == &si->erase)
  77                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  78         else if (list == &si->corr)
  79                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  80         else if (list == &si->alien)
  81                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  82         else
  83                 BUG();
  84
  85         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  86         if (!seb)
  87                 return -ENOMEM;
  88
  89         seb->pnum = pnum;
  90         seb->ec = ec;
  91         list_add_tail(&seb->u.list, list);
  92         return 0;
  93 }
  94
  95 /**
  96  * commit_to_mean_value - commit intermediate results to the final mean erase
  97  * counter value.
  98  * @si: scanning information
  99  *
 100  * This is a helper function which calculates partial mean erase counter mean
 101  * value and adds it to the resulting mean value. As we can work only in
 102  * integer arithmetic and we want to calculate the mean value of erase counter
 103  * accurately, we first sum erase counter values in @si->ec_sum variable and
 104  * count these components in @si->ec_count. If this temporary @si->ec_sum is
 105  * going to overflow, we calculate the partial mean value
 106  * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
 107  */
 108 static void commit_to_mean_value(struct ubi_scan_info *si)
 109 {
 110         si->ec_sum /= si->ec_count;
 111         if (si->ec_sum % si->ec_count >= si->ec_count / 2)
 112                 si->mean_ec += 1;
 113         si->mean_ec += si->ec_sum;
 114 }
 115
 116 /**
 117  * validate_vid_hdr - check that volume identifier header is correct and
 118  * consistent.
 119  * @vid_hdr: the volume identifier header to check
 120  * @sv: information about the volume this logical eraseblock belongs to
 121  * @pnum: physical eraseblock number the VID header came from
 122  *
 123  * This function checks that data stored in @vid_hdr is consistent. Returns
 124  * non-zero if an inconsistency was found and zero if not.
 125  *
 126  * Note, UBI does sanity check of everything it reads from the flash media.
 127  * Most of the checks are done in the I/O unit. Here we check that the
 128  * information in the VID header is consistent to the information in other VID
 129  * headers of the same volume.
 130  */
 131 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 132                             const struct ubi_scan_volume *sv, int pnum)
 133 {
 134         int vol_type = vid_hdr->vol_type;
 135         int vol_id = ubi32_to_cpu(vid_hdr->vol_id);
 136         int used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 137         int data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 138
 139         if (sv->leb_count != 0) {
 140                 int sv_vol_type;
 141
 142                 /*
 143                  * This is not the first logical eraseblock belonging to this
 144                  * volume. Ensure that the data in its VID header is consistent
 145                  * to the data in previous logical eraseblock headers.
 146                  */
 147
 148                 if (vol_id != sv->vol_id) {
 149                         dbg_err("inconsistent vol_id");
 150                         goto bad;
 151                 }
 152
 153                 if (sv->vol_type == UBI_STATIC_VOLUME)
 154                         sv_vol_type = UBI_VID_STATIC;
 155                 else
 156                         sv_vol_type = UBI_VID_DYNAMIC;
 157
 158                 if (vol_type != sv_vol_type) {
 159                         dbg_err("inconsistent vol_type");
 160                         goto bad;
 161                 }
 162
 163                 if (used_ebs != sv->used_ebs) {
 164                         dbg_err("inconsistent used_ebs");
 165                         goto bad;
 166                 }
 167
 168                 if (data_pad != sv->data_pad) {
 169                         dbg_err("inconsistent data_pad");
 170                         goto bad;
 171                 }
 172         }
 173
 174         return 0;
 175
 176 bad:
 177         ubi_err("inconsistent VID header at PEB %d", pnum);
 178         ubi_dbg_dump_vid_hdr(vid_hdr);
 179         ubi_dbg_dump_sv(sv);
 180         return -EINVAL;
 181 }
 182
 183 /**
 184  * add_volume - add volume to the scanning information.
 185  * @si: scanning information
 186  * @vol_id: ID of the volume to add
 187  * @pnum: physical eraseblock number
 188  * @vid_hdr: volume identifier header
 189  *
 190  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 191  * present in the scanning information, this function does nothing. Otherwise
 192  * it adds corresponding volume to the scanning information. Returns a pointer
 193  * to the scanning volume object in case of success and a negative error code
 194  * in case of failure.
 195  */
 196 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 197                                           int pnum,
 198                                           const struct ubi_vid_hdr *vid_hdr)
 199 {
 200         struct ubi_scan_volume *sv;
 201         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 202
 203         ubi_assert(vol_id == ubi32_to_cpu(vid_hdr->vol_id));
 204
 205         /* Walk the volume RB-tree to look if this volume is already present */
 206         while (*p) {
 207                 parent = *p;
 208                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 209
 210                 if (vol_id == sv->vol_id)
 211                         return sv;
 212
 213                 if (vol_id > sv->vol_id)
 214                         p = &(*p)->rb_left;
 215                 else
 216                         p = &(*p)->rb_right;
 217         }
 218
 219         /* The volume is absent - add it */
 220         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 221         if (!sv)
 222                 return ERR_PTR(-ENOMEM);
 223
 224         sv->highest_lnum = sv->leb_count = 0;
 225         si->max_sqnum = 0;
 226         sv->vol_id = vol_id;
 227         sv->root = RB_ROOT;
 228         sv->used_ebs = ubi32_to_cpu(vid_hdr->used_ebs);
 229         sv->data_pad = ubi32_to_cpu(vid_hdr->data_pad);
 230         sv->compat = vid_hdr->compat;
 231         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 232                                                             : UBI_STATIC_VOLUME;
 233         if (vol_id > si->highest_vol_id)
 234                 si->highest_vol_id = vol_id;
 235
 236         rb_link_node(&sv->rb, parent, p);
 237         rb_insert_color(&sv->rb, &si->volumes);
 238         si->vols_found += 1;
 239         dbg_bld("added volume %d", vol_id);
 240         return sv;
 241 }
 242
 243 /**
 244  * compare_lebs - find out which logical eraseblock is newer.
 245  * @ubi: UBI device description object
 246  * @seb: first logical eraseblock to compare
 247  * @pnum: physical eraseblock number of the second logical eraseblock to
 248  * compare
 249  * @vid_hdr: volume identifier header of the second logical eraseblock
 250  *
 251  * This function compares 2 copies of a LEB and informs which one is newer. In
 252  * case of success this function returns a positive value, in case of failure, a
 253  * negative error code is returned. The success return codes use the following
 254  * bits:
 255  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 256  *       second PEB (described by @pnum and @vid_hdr);
 257  *     o bit 0 is set: the second PEB is newer;
 258  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 259  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 260  *     o bit 2 is cleared: the older LEB is not corrupted;
 261  *     o bit 2 is set: the older LEB is corrupted.
 262  */
 263 static int compare_lebs(const struct ubi_device *ubi,
 264                         const struct ubi_scan_leb *seb, int pnum,
 265                         const struct ubi_vid_hdr *vid_hdr)
 266 {
 267         void *buf;
 268         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 269         uint32_t data_crc, crc;
 270         struct ubi_vid_hdr *vidh = NULL;
 271         unsigned long long sqnum2 = ubi64_to_cpu(vid_hdr->sqnum);
 272
 273         if (seb->sqnum == 0 && sqnum2 == 0) {
 274                 long long abs, v1 = seb->leb_ver, v2 = ubi32_to_cpu(vid_hdr->leb_ver);
 275
 276                 /*
 277                  * UBI constantly increases the logical eraseblock version
 278                  * number and it can overflow. Thus, we have to bear in mind
 279                  * that versions that are close to %0xFFFFFFFF are less then
 280                  * versions that are close to %0.
 281                  *
 282                  * The UBI WL unit guarantees that the number of pending tasks
 283                  * is not greater then %0x7FFFFFFF. So, if the difference
 284                  * between any two versions is greater or equivalent to
 285                  * %0x7FFFFFFF, there was an overflow and the logical
 286                  * eraseblock with lower version is actually newer then the one
 287                  * with higher version.
 288                  *
 289                  * FIXME: but this is anyway obsolete and will be removed at
 290                  * some point.
 291                  */
 292
 293                 dbg_bld("using old crappy leb_ver stuff");
 294
 295                 abs = v1 - v2;
 296                 if (abs < 0)
 297                         abs = -abs;
 298
 299                 if (abs < 0x7FFFFFFF)
 300                         /* Non-overflow situation */
 301                         second_is_newer = (v2 > v1);
 302                 else
 303                         second_is_newer = (v2 < v1);
 304         } else
 305                 /* Obviously the LEB with lower sequence counter is older */
 306                 second_is_newer = sqnum2 > seb->sqnum;
 307
 308         /*
 309          * Now we know which copy is newer. If the copy flag of the PEB with
 310          * newer version is not set, then we just return, otherwise we have to
 311          * check data CRC. For the second PEB we already have the VID header,
 312          * for the first one - we'll need to re-read it from flash.
 313          *
 314          * FIXME: this may be optimized so that we wouldn't read twice.
 315          */
 316
 317         if (second_is_newer) {
 318                 if (!vid_hdr->copy_flag) {
 319                         /* It is not a copy, so it is newer */
 320                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 321                                 pnum);
 322                         return 1;
 323                 }
 324         } else {
 325                 pnum = seb->pnum;
 326
 327                 vidh = ubi_zalloc_vid_hdr(ubi);
 328                 if (!vidh)
 329                         return -ENOMEM;
 330
 331                 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 332                 if (err) {
 333                         if (err == UBI_IO_BITFLIPS)
 334                                 bitflips = 1;
 335                         else {
 336                                 dbg_err("VID of PEB %d header is bad, but it "
 337                                         "was OK earlier", pnum);
 338                                 if (err > 0)
 339                                         err = -EIO;
 340
 341                                 goto out_free_vidh;
 342                         }
 343                 }
 344
 345                 if (!vidh->copy_flag) {
 346                         /* It is not a copy, so it is newer */
 347                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 348                                 pnum);
 349                         err = bitflips << 1;
 350                         goto out_free_vidh;
 351                 }
 352
 353                 vid_hdr = vidh;
 354         }
 355
 356         /* Read the data of the copy and check the CRC */
 357
 358         len = ubi32_to_cpu(vid_hdr->data_size);
 359         buf = vmalloc(len);
 360         if (!buf) {
 361                 err = -ENOMEM;
 362                 goto out_free_vidh;
 363         }
 364
 365         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 366         if (err && err != UBI_IO_BITFLIPS)
 367                 goto out_free_buf;
 368
 369         data_crc = ubi32_to_cpu(vid_hdr->data_crc);
 370         crc = crc32(UBI_CRC32_INIT, buf, len);
 371         if (crc != data_crc) {
 372                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 373                         pnum, crc, data_crc);
 374                 corrupted = 1;
 375                 bitflips = 0;
 376                 second_is_newer = !second_is_newer;
 377         } else {
 378                 dbg_bld("PEB %d CRC is OK", pnum);
 379                 bitflips = !!err;
 380         }
 381
 382         vfree(buf);
 383         ubi_free_vid_hdr(ubi, vidh);
 384
 385         if (second_is_newer)
 386                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 387         else
 388                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 389
 390         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 391
 392 out_free_buf:
 393         vfree(buf);
 394 out_free_vidh:
 395         ubi_free_vid_hdr(ubi, vidh);
 396         ubi_assert(err < 0);
 397         return err;
 398 }
 399
 400 /**
 401  * ubi_scan_add_used - add information about a physical eraseblock to the
 402  * scanning information.
 403  * @ubi: UBI device description object
 404  * @si: scanning information
 405  * @pnum: the physical eraseblock number
 406  * @ec: erase counter
 407  * @vid_hdr: the volume identifier header
 408  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 409  *
 410  * This function adds information about a used physical eraseblock to the
 411  * 'used' tree of the corresponding volume. The function is rather complex
 412  * because it has to handle cases when this is not the first physical
 413  * eraseblock belonging to the same logical eraseblock, and the newer one has
 414  * to be picked, while the older one has to be dropped. This function returns
 415  * zero in case of success and a negative error code in case of failure.
 416  */
 417 int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si,
 418                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 419                       int bitflips)
 420 {
 421         int err, vol_id, lnum;
 422         uint32_t leb_ver;
 423         unsigned long long sqnum;
 424         struct ubi_scan_volume *sv;
 425         struct ubi_scan_leb *seb;
 426         struct rb_node **p, *parent = NULL;
 427
 428         vol_id = ubi32_to_cpu(vid_hdr->vol_id);
 429         lnum = ubi32_to_cpu(vid_hdr->lnum);
 430         sqnum = ubi64_to_cpu(vid_hdr->sqnum);
 431         leb_ver = ubi32_to_cpu(vid_hdr->leb_ver);
 432
 433         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 434                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 435
 436         sv = add_volume(si, vol_id, pnum, vid_hdr);
 437         if (IS_ERR(sv) < 0)
 438                 return PTR_ERR(sv);
 439
 440         /*
 441          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 442          * if this is the first instance of this logical eraseblock or not.
 443          */
 444         p = &sv->root.rb_node;
 445         while (*p) {
 446                 int cmp_res;
 447
 448                 parent = *p;
 449                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 450                 if (lnum != seb->lnum) {
 451                         if (lnum < seb->lnum)
 452                                 p = &(*p)->rb_left;
 453                         else
 454                                 p = &(*p)->rb_right;
 455                         continue;
 456                 }
 457
 458                 /*
 459                  * There is already a physical eraseblock describing the same
 460                  * logical eraseblock present.
 461                  */
 462
 463                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 464                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 465                         seb->leb_ver, seb->ec);
 466
 467                 /*
 468                  * Make sure that the logical eraseblocks have different
 469                  * versions. Otherwise the image is bad.
 470                  */
 471                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 472                         ubi_err("two LEBs with same version %u", leb_ver);
 473                         ubi_dbg_dump_seb(seb, 0);
 474                         ubi_dbg_dump_vid_hdr(vid_hdr);
 475                         return -EINVAL;
 476                 }
 477
 478                 /*
 479                  * Make sure that the logical eraseblocks have different
 480                  * sequence numbers. Otherwise the image is bad.
 481                  *
 482                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 483                  */
 484                 if (seb->sqnum == sqnum && sqnum != 0) {
 485                         ubi_err("two LEBs with same sequence number %llu",
 486                                 sqnum);
 487                         ubi_dbg_dump_seb(seb, 0);
 488                         ubi_dbg_dump_vid_hdr(vid_hdr);
 489                         return -EINVAL;
 490                 }
 491
 492                 /*
 493                  * Now we have to drop the older one and preserve the newer
 494                  * one.
 495                  */
 496                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 497                 if (cmp_res < 0)
 498                         return cmp_res;
 499
 500                 if (cmp_res & 1) {
 501                         /*
 502                          * This logical eraseblock is newer then the one
 503                          * found earlier.
 504                          */
 505                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 506                         if (err)
 507                                 return err;
 508
 509                         if (cmp_res & 4)
 510                                 err = add_to_list(si, seb->pnum, seb->ec,
 511                                                   &si->corr);
 512                         else
 513                                 err = add_to_list(si, seb->pnum, seb->ec,
 514                                                   &si->erase);
 515                         if (err)
 516                                 return err;
 517
 518                         seb->ec = ec;
 519                         seb->pnum = pnum;
 520                         seb->scrub = ((cmp_res & 2) || bitflips);
 521                         seb->sqnum = sqnum;
 522                         seb->leb_ver = leb_ver;
 523
 524                         if (sv->highest_lnum == lnum)
 525                                 sv->last_data_size =
 526                                         ubi32_to_cpu(vid_hdr->data_size);
 527
 528                         return 0;
 529                 } else {
 530                         /*
 531                          * This logical eraseblock is older then the one found
 532                          * previously.
 533                          */
 534                         if (cmp_res & 4)
 535                                 return add_to_list(si, pnum, ec, &si->corr);
 536                         else
 537                                 return add_to_list(si, pnum, ec, &si->erase);
 538                 }
 539         }
 540
 541         /*
 542          * We've met this logical eraseblock for the first time, add it to the
 543          * scanning information.
 544          */
 545
 546         err = validate_vid_hdr(vid_hdr, sv, pnum);
 547         if (err)
 548                 return err;
 549
 550         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 551         if (!seb)
 552                 return -ENOMEM;
 553
 554         seb->ec = ec;
 555         seb->pnum = pnum;
 556         seb->lnum = lnum;
 557         seb->sqnum = sqnum;
 558         seb->scrub = bitflips;
 559         seb->leb_ver = leb_ver;
 560
 561         if (sv->highest_lnum <= lnum) {
 562                 sv->highest_lnum = lnum;
 563                 sv->last_data_size = ubi32_to_cpu(vid_hdr->data_size);
 564         }
 565
 566         if (si->max_sqnum < sqnum)
 567                 si->max_sqnum = sqnum;
 568
 569         sv->leb_count += 1;
 570         rb_link_node(&seb->u.rb, parent, p);
 571         rb_insert_color(&seb->u.rb, &sv->root);
 572         return 0;
 573 }
 574
 575 /**
 576  * ubi_scan_find_sv - find information about a particular volume in the
 577  * scanning information.
 578  * @si: scanning information
 579  * @vol_id: the requested volume ID
 580  *
 581  * This function returns a pointer to the volume description or %NULL if there
 582  * are no data about this volume in the scanning information.
 583  */
 584 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 585                                          int vol_id)
 586 {
 587         struct ubi_scan_volume *sv;
 588         struct rb_node *p = si->volumes.rb_node;
 589
 590         while (p) {
 591                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 592
 593                 if (vol_id == sv->vol_id)
 594                         return sv;
 595
 596                 if (vol_id > sv->vol_id)
 597                         p = p->rb_left;
 598                 else
 599                         p = p->rb_right;
 600         }
 601
 602         return NULL;
 603 }
 604
 605 /**
 606  * ubi_scan_find_seb - find information about a particular logical
 607  * eraseblock in the volume scanning information.
 608  * @sv: a pointer to the volume scanning information
 609  * @lnum: the requested logical eraseblock
 610  *
 611  * This function returns a pointer to the scanning logical eraseblock or %NULL
 612  * if there are no data about it in the scanning volume information.
 613  */
 614 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 615                                        int lnum)
 616 {
 617         struct ubi_scan_leb *seb;
 618         struct rb_node *p = sv->root.rb_node;
 619
 620         while (p) {
 621                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 622
 623                 if (lnum == seb->lnum)
 624                         return seb;
 625
 626                 if (lnum > seb->lnum)
 627                         p = p->rb_left;
 628                 else
 629                         p = p->rb_right;
 630         }
 631
 632         return NULL;
 633 }
 634
 635 /**
 636  * ubi_scan_rm_volume - delete scanning information about a volume.
 637  * @si: scanning information
 638  * @sv: the volume scanning information to delete
 639  */
 640 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 641 {
 642         struct rb_node *rb;
 643         struct ubi_scan_leb *seb;
 644
 645         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 646
 647         while ((rb = rb_first(&sv->root))) {
 648                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 649                 rb_erase(&seb->u.rb, &sv->root);
 650                 list_add_tail(&seb->u.list, &si->erase);
 651         }
 652
 653         rb_erase(&sv->rb, &si->volumes);
 654         kfree(sv);
 655         si->vols_found -= 1;
 656 }
 657
 658 /**
 659  * ubi_scan_erase_peb - erase a physical eraseblock.
 660  * @ubi: UBI device description object
 661  * @si: scanning information
 662  * @pnum: physical eraseblock number to erase;
 663  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 664  *
 665  * This function erases physical eraseblock 'pnum', and writes the erase
 666  * counter header to it. This function should only be used on UBI device
 667  * initialization stages, when the EBA unit had not been yet initialized. This
 668  * function returns zero in case of success and a negative error code in case
 669  * of failure.
 670  */
 671 int ubi_scan_erase_peb(const struct ubi_device *ubi,
 672                        const struct ubi_scan_info *si, int pnum, int ec)
 673 {
 674         int err;
 675         struct ubi_ec_hdr *ec_hdr;
 676
 677         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 678         if (!ec_hdr)
 679                 return -ENOMEM;
 680
 681         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 682                 /*
 683                  * Erase counter overflow. Upgrade UBI and use 64-bit
 684                  * erase counters internally.
 685                  */
 686                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 687                 return -EINVAL;
 688         }
 689
 690         ec_hdr->ec = cpu_to_ubi64(ec);
 691
 692         err = ubi_io_sync_erase(ubi, pnum, 0);
 693         if (err < 0)
 694                 goto out_free;
 695
 696         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 697
 698 out_free:
 699         kfree(ec_hdr);
 700         return err;
 701 }
 702
 703 /**
 704  * ubi_scan_get_free_peb - get a free physical eraseblock.
 705  * @ubi: UBI device description object
 706  * @si: scanning information
 707  *
 708  * This function returns a free physical eraseblock. It is supposed to be
 709  * called on the UBI initialization stages when the wear-leveling unit is not
 710  * initialized yet. This function picks a physical eraseblocks from one of the
 711  * lists, writes the EC header if it is needed, and removes it from the list.
 712  *
 713  * This function returns scanning physical eraseblock information in case of
 714  * success and an error code in case of failure.
 715  */
 716 struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
 717                                            struct ubi_scan_info *si)
 718 {
 719         int err = 0, i;
 720         struct ubi_scan_leb *seb;
 721
 722         if (!list_empty(&si->free)) {
 723                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 724                 list_del(&seb->u.list);
 725                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 726                 return seb;
 727         }
 728
 729         for (i = 0; i < 2; i++) {
 730                 struct list_head *head;
 731                 struct ubi_scan_leb *tmp_seb;
 732
 733                 if (i == 0)
 734                         head = &si->erase;
 735                 else
 736                         head = &si->corr;
 737
 738                 /*
 739                  * We try to erase the first physical eraseblock from the @head
 740                  * list and pick it if we succeed, or try to erase the
 741                  * next one if not. And so forth. We don't want to take care
 742                  * about bad eraseblocks here - they'll be handled later.
 743                  */
 744                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 745                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 746                                 seb->ec = si->mean_ec;
 747
 748                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 749                         if (err)
 750                                 continue;
 751
 752                         seb->ec += 1;
 753                         list_del(&seb->u.list);
 754                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 755                         return seb;
 756                 }
 757         }
 758
 759         ubi_err("no eraseblocks found");
 760         return ERR_PTR(-ENOSPC);
 761 }
 762
 763 /**
 764  * process_eb - read UBI headers, check them and add corresponding data
 765  * to the scanning information.
 766  * @ubi: UBI device description object
 767  * @si: scanning information
 768  * @pnum: the physical eraseblock number
 769  *
 770  * This function returns a zero if the physical eraseblock was successfully
 771  * handled and a negative error code in case of failure.
 772  */
 773 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 774 {
 775         long long ec;
 776         int err, bitflips = 0, vol_id, ec_corr = 0;
 777
 778         dbg_bld("scan PEB %d", pnum);
 779
 780         /* Skip bad physical eraseblocks */
 781         err = ubi_io_is_bad(ubi, pnum);
 782         if (err < 0)
 783                 return err;
 784         else if (err) {
 785                 /*
 786                  * FIXME: this is actually duty of the I/O unit to initialize
 787                  * this, but MTD does not provide enough information.
 788                  */
 789                 si->bad_peb_count += 1;
 790                 return 0;
 791         }
 792
 793         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 794         if (err < 0)
 795                 return err;
 796         else if (err == UBI_IO_BITFLIPS)
 797                 bitflips = 1;
 798         else if (err == UBI_IO_PEB_EMPTY)
 799                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 800         else if (err == UBI_IO_BAD_EC_HDR) {
 801                 /*
 802                  * We have to also look at the VID header, possibly it is not
 803                  * corrupted. Set %bitflips flag in order to make this PEB be
 804                  * moved and EC be re-created.
 805                  */
 806                 ec_corr = 1;
 807                 ec = UBI_SCAN_UNKNOWN_EC;
 808                 bitflips = 1;
 809         }
 810
 811         si->is_empty = 0;
 812
 813         if (!ec_corr) {
 814                 /* Make sure UBI version is OK */
 815                 if (ech->version != UBI_VERSION) {
 816                         ubi_err("this UBI version is %d, image version is %d",
 817                                 UBI_VERSION, (int)ech->version);
 818                         return -EINVAL;
 819                 }
 820
 821                 ec = ubi64_to_cpu(ech->ec);
 822                 if (ec > UBI_MAX_ERASECOUNTER) {
 823                         /*
 824                          * Erase counter overflow. The EC headers have 64 bits
 825                          * reserved, but we anyway make use of only 31 bit
 826                          * values, as this seems to be enough for any existing
 827                          * flash. Upgrade UBI and use 64-bit erase counters
 828                          * internally.
 829                          */
 830                         ubi_err("erase counter overflow, max is %d",
 831                                 UBI_MAX_ERASECOUNTER);
 832                         ubi_dbg_dump_ec_hdr(ech);
 833                         return -EINVAL;
 834                 }
 835         }
 836
 837         /* OK, we've done with the EC header, let's look at the VID header */
 838
 839         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 840         if (err < 0)
 841                 return err;
 842         else if (err == UBI_IO_BITFLIPS)
 843                 bitflips = 1;
 844         else if (err == UBI_IO_BAD_VID_HDR ||
 845                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 846                 /* VID header is corrupted */
 847                 err = add_to_list(si, pnum, ec, &si->corr);
 848                 if (err)
 849                         return err;
 850                 goto adjust_mean_ec;
 851         } else if (err == UBI_IO_PEB_FREE) {
 852                 /* No VID header - the physical eraseblock is free */
 853                 err = add_to_list(si, pnum, ec, &si->free);
 854                 if (err)
 855                         return err;
 856                 goto adjust_mean_ec;
 857         }
 858
 859         vol_id = ubi32_to_cpu(vidh->vol_id);
 860         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
 861                 int lnum = ubi32_to_cpu(vidh->lnum);
 862
 863                 /* Unsupported internal volume */
 864                 switch (vidh->compat) {
 865                 case UBI_COMPAT_DELETE:
 866                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 867                                 " found, remove it", vol_id, lnum);
 868                         err = add_to_list(si, pnum, ec, &si->corr);
 869                         if (err)
 870                                 return err;
 871                         break;
 872
 873                 case UBI_COMPAT_RO:
 874                         ubi_msg("read-only compatible internal volume %d:%d"
 875                                 " found, switch to read-only mode",
 876                                 vol_id, lnum);
 877                         ubi->ro_mode = 1;
 878                         break;
 879
 880                 case UBI_COMPAT_PRESERVE:
 881                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 882                                 " found", vol_id, lnum);
 883                         err = add_to_list(si, pnum, ec, &si->alien);
 884                         if (err)
 885                                 return err;
 886                         si->alien_peb_count += 1;
 887                         return 0;
 888
 889                 case UBI_COMPAT_REJECT:
 890                         ubi_err("incompatible internal volume %d:%d found",
 891                                 vol_id, lnum);
 892                         return -EINVAL;
 893                 }
 894         }
 895
 896         /* Both UBI headers seem to be fine */
 897         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 898         if (err)
 899                 return err;
 900
 901 adjust_mean_ec:
 902         if (!ec_corr) {
 903                 if (si->ec_sum + ec < ec) {
 904                         commit_to_mean_value(si);
 905                         si->ec_sum = 0;
 906                         si->ec_count = 0;
 907                 } else {
 908                         si->ec_sum += ec;
 909                         si->ec_count += 1;
 910                 }
 911
 912                 if (ec > si->max_ec)
 913                         si->max_ec = ec;
 914                 if (ec < si->min_ec)
 915                         si->min_ec = ec;
 916         }
 917
 918         return 0;
 919 }
 920
 921 /**
 922  * ubi_scan - scan an MTD device.
 923  * @ubi: UBI device description object
 924  *
 925  * This function does full scanning of an MTD device and returns complete
 926  * information about it. In case of failure, an error code is returned.
 927  */
 928 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 929 {
 930         int err, pnum;
 931         struct rb_node *rb1, *rb2;
 932         struct ubi_scan_volume *sv;
 933         struct ubi_scan_leb *seb;
 934         struct ubi_scan_info *si;
 935
 936         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 937         if (!si)
 938                 return ERR_PTR(-ENOMEM);
 939
 940         INIT_LIST_HEAD(&si->corr);
 941         INIT_LIST_HEAD(&si->free);
 942         INIT_LIST_HEAD(&si->erase);
 943         INIT_LIST_HEAD(&si->alien);
 944         si->volumes = RB_ROOT;
 945         si->is_empty = 1;
 946
 947         err = -ENOMEM;
 948         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 949         if (!ech)
 950                 goto out_si;
 951
 952         vidh = ubi_zalloc_vid_hdr(ubi);
 953         if (!vidh)
 954                 goto out_ech;
 955
 956         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 957                 cond_resched();
 958
 959                 dbg_msg("process PEB %d", pnum);
 960                 err = process_eb(ubi, si, pnum);
 961                 if (err < 0)
 962                         goto out_vidh;
 963         }
 964
 965         dbg_msg("scanning is finished");
 966
 967         /* Finish mean erase counter calculations */
 968         if (si->ec_count)
 969                 commit_to_mean_value(si);
 970
 971         if (si->is_empty)
 972                 ubi_msg("empty MTD device detected");
 973
 974         /*
 975          * In case of unknown erase counter we use the mean erase counter
 976          * value.
 977          */
 978         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 979                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 980                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 981                                 seb->ec = si->mean_ec;
 982         }
 983
 984         list_for_each_entry(seb, &si->free, u.list) {
 985                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 986                         seb->ec = si->mean_ec;
 987         }
 988
 989         list_for_each_entry(seb, &si->corr, u.list)
 990                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 991                         seb->ec = si->mean_ec;
 992
 993         list_for_each_entry(seb, &si->erase, u.list)
 994                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 995                         seb->ec = si->mean_ec;
 996
 997         err = paranoid_check_si(ubi, si);
 998         if (err) {
 999                 if (err > 0)
1000                         err = -EINVAL;
1001                 goto out_vidh;
1002         }
1003
1004         ubi_free_vid_hdr(ubi, vidh);
1005         kfree(ech);
1006
1007         return si;
1008
1009 out_vidh:
1010         ubi_free_vid_hdr(ubi, vidh);
1011 out_ech:
1012         kfree(ech);
1013 out_si:
1014         ubi_scan_destroy_si(si);
1015         return ERR_PTR(err);
1016 }
1017
1018 /**
1019  * destroy_sv - free the scanning volume information
1020  * @sv: scanning volume information
1021  *
1022  * This function destroys the volume RB-tree (@sv->root) and the scanning
1023  * volume information.
1024  */
1025 static void destroy_sv(struct ubi_scan_volume *sv)
1026 {
1027         struct ubi_scan_leb *seb;
1028         struct rb_node *this = sv->root.rb_node;
1029
1030         while (this) {
1031                 if (this->rb_left)
1032                         this = this->rb_left;
1033                 else if (this->rb_right)
1034                         this = this->rb_right;
1035                 else {
1036                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1037                         this = rb_parent(this);
1038                         if (this) {
1039                                 if (this->rb_left == &seb->u.rb)
1040                                         this->rb_left = NULL;
1041                                 else
1042                                         this->rb_right = NULL;
1043                         }
1044
1045                         kfree(seb);
1046                 }
1047         }
1048         kfree(sv);
1049 }
1050
1051 /**
1052  * ubi_scan_destroy_si - destroy scanning information.
1053  * @si: scanning information
1054  */
1055 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1056 {
1057         struct ubi_scan_leb *seb, *seb_tmp;
1058         struct ubi_scan_volume *sv;
1059         struct rb_node *rb;
1060
1061         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1062                 list_del(&seb->u.list);
1063                 kfree(seb);
1064         }
1065         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1066                 list_del(&seb->u.list);
1067                 kfree(seb);
1068         }
1069         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1070                 list_del(&seb->u.list);
1071                 kfree(seb);
1072         }
1073         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1074                 list_del(&seb->u.list);
1075                 kfree(seb);
1076         }
1077
1078         /* Destroy the volume RB-tree */
1079         rb = si->volumes.rb_node;
1080         while (rb) {
1081                 if (rb->rb_left)
1082                         rb = rb->rb_left;
1083                 else if (rb->rb_right)
1084                         rb = rb->rb_right;
1085                 else {
1086                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1087
1088                         rb = rb_parent(rb);
1089                         if (rb) {
1090                                 if (rb->rb_left == &sv->rb)
1091                                         rb->rb_left = NULL;
1092                                 else
1093                                         rb->rb_right = NULL;
1094                         }
1095
1096                         destroy_sv(sv);
1097                 }
1098         }
1099
1100         kfree(si);
1101 }
1102
1103 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1104
1105 /**
1106  * paranoid_check_si - check if the scanning information is correct and
1107  * consistent.
1108  * @ubi: UBI device description object
1109  * @si: scanning information
1110  *
1111  * This function returns zero if the scanning information is all right, %1 if
1112  * not and a negative error code if an error occurred.
1113  */
1114 static int paranoid_check_si(const struct ubi_device *ubi,
1115                              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 != ubi64_to_cpu(vidh->sqnum)) {
1265                                 ubi_err("bad sqnum %llu", seb->sqnum);
1266                                 goto bad_vid_hdr;
1267                         }
1268
1269                         if (sv->vol_id != ubi32_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 != ubi32_to_cpu(vidh->lnum)) {
1280                                 ubi_err("bad lnum %d", seb->lnum);
1281                                 goto bad_vid_hdr;
1282                         }
1283
1284                         if (sv->used_ebs != ubi32_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 != ubi32_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 != ubi32_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 != ubi32_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 != ubi32_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 = kmalloc(ubi->peb_count, GFP_KERNEL);
1319         if (!buf)
1320                 return -ENOMEM;
1321
1322         memset(buf, 1, ubi->peb_count);
1323         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1324                 err = ubi_io_is_bad(ubi, pnum);
1325                 if (err < 0) {
1326                         kfree(buf);
1327                         return err;
1328                 }
1329                 else if (err)
1330                         buf[pnum] = 0;
1331         }
1332
1333         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1334                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1335                         buf[seb->pnum] = 0;
1336
1337         list_for_each_entry(seb, &si->free, u.list)
1338                 buf[seb->pnum] = 0;
1339
1340         list_for_each_entry(seb, &si->corr, u.list)
1341                 buf[seb->pnum] = 0;
1342
1343         list_for_each_entry(seb, &si->erase, u.list)
1344                 buf[seb->pnum] = 0;
1345
1346         list_for_each_entry(seb, &si->alien, u.list)
1347                 buf[seb->pnum] = 0;
1348
1349         err = 0;
1350         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1351                 if (buf[pnum]) {
1352                         ubi_err("PEB %d is not referred", pnum);
1353                         err = 1;
1354                 }
1355
1356         kfree(buf);
1357         if (err)
1358                 goto out;
1359         return 0;
1360
1361 bad_seb:
1362         ubi_err("bad scanning information about LEB %d", seb->lnum);
1363         ubi_dbg_dump_seb(seb, 0);
1364         ubi_dbg_dump_sv(sv);
1365         goto out;
1366
1367 bad_sv:
1368         ubi_err("bad scanning information about volume %d", sv->vol_id);
1369         ubi_dbg_dump_sv(sv);
1370         goto out;
1371
1372 bad_vid_hdr:
1373         ubi_err("bad scanning information about volume %d", sv->vol_id);
1374         ubi_dbg_dump_sv(sv);
1375         ubi_dbg_dump_vid_hdr(vidh);
1376
1377 out:
1378         ubi_dbg_dump_stack();
1379         return 1;
1380 }
1381
1382 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */