SAFE public projects git trees. - safe/jmp/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 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/crc32.h>
  45 #include <asm/div64.h>
  46 #include "ubi.h"
  47
  48 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  49 static int paranoid_check_si(struct ubi_device *ubi, 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  * validate_vid_hdr - check that volume identifier header is correct and
  97  * consistent.
  98  * @vid_hdr: the volume identifier header to check
  99  * @sv: information about the volume this logical eraseblock belongs to
 100  * @pnum: physical eraseblock number the VID header came from
 101  *
 102  * This function checks that data stored in @vid_hdr is consistent. Returns
 103  * non-zero if an inconsistency was found and zero if not.
 104  *
 105  * Note, UBI does sanity check of everything it reads from the flash media.
 106  * Most of the checks are done in the I/O sub-system. Here we check that the
 107  * information in the VID header is consistent to the information in other VID
 108  * headers of the same volume.
 109  */
 110 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 111                             const struct ubi_scan_volume *sv, int pnum)
 112 {
 113         int vol_type = vid_hdr->vol_type;
 114         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 115         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 116         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 117
 118         if (sv->leb_count != 0) {
 119                 int sv_vol_type;
 120
 121                 /*
 122                  * This is not the first logical eraseblock belonging to this
 123                  * volume. Ensure that the data in its VID header is consistent
 124                  * to the data in previous logical eraseblock headers.
 125                  */
 126
 127                 if (vol_id != sv->vol_id) {
 128                         dbg_err("inconsistent vol_id");
 129                         goto bad;
 130                 }
 131
 132                 if (sv->vol_type == UBI_STATIC_VOLUME)
 133                         sv_vol_type = UBI_VID_STATIC;
 134                 else
 135                         sv_vol_type = UBI_VID_DYNAMIC;
 136
 137                 if (vol_type != sv_vol_type) {
 138                         dbg_err("inconsistent vol_type");
 139                         goto bad;
 140                 }
 141
 142                 if (used_ebs != sv->used_ebs) {
 143                         dbg_err("inconsistent used_ebs");
 144                         goto bad;
 145                 }
 146
 147                 if (data_pad != sv->data_pad) {
 148                         dbg_err("inconsistent data_pad");
 149                         goto bad;
 150                 }
 151         }
 152
 153         return 0;
 154
 155 bad:
 156         ubi_err("inconsistent VID header at PEB %d", pnum);
 157         ubi_dbg_dump_vid_hdr(vid_hdr);
 158         ubi_dbg_dump_sv(sv);
 159         return -EINVAL;
 160 }
 161
 162 /**
 163  * add_volume - add volume to the scanning information.
 164  * @si: scanning information
 165  * @vol_id: ID of the volume to add
 166  * @pnum: physical eraseblock number
 167  * @vid_hdr: volume identifier header
 168  *
 169  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 170  * present in the scanning information, this function does nothing. Otherwise
 171  * it adds corresponding volume to the scanning information. Returns a pointer
 172  * to the scanning volume object in case of success and a negative error code
 173  * in case of failure.
 174  */
 175 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 176                                           int pnum,
 177                                           const struct ubi_vid_hdr *vid_hdr)
 178 {
 179         struct ubi_scan_volume *sv;
 180         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 181
 182         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 183
 184         /* Walk the volume RB-tree to look if this volume is already present */
 185         while (*p) {
 186                 parent = *p;
 187                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 188
 189                 if (vol_id == sv->vol_id)
 190                         return sv;
 191
 192                 if (vol_id > sv->vol_id)
 193                         p = &(*p)->rb_left;
 194                 else
 195                         p = &(*p)->rb_right;
 196         }
 197
 198         /* The volume is absent - add it */
 199         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 200         if (!sv)
 201                 return ERR_PTR(-ENOMEM);
 202
 203         sv->highest_lnum = sv->leb_count = 0;
 204         sv->vol_id = vol_id;
 205         sv->root = RB_ROOT;
 206         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 207         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 208         sv->compat = vid_hdr->compat;
 209         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 210                                                             : UBI_STATIC_VOLUME;
 211         if (vol_id > si->highest_vol_id)
 212                 si->highest_vol_id = vol_id;
 213
 214         rb_link_node(&sv->rb, parent, p);
 215         rb_insert_color(&sv->rb, &si->volumes);
 216         si->vols_found += 1;
 217         dbg_bld("added volume %d", vol_id);
 218         return sv;
 219 }
 220
 221 /**
 222  * compare_lebs - find out which logical eraseblock is newer.
 223  * @ubi: UBI device description object
 224  * @seb: first logical eraseblock to compare
 225  * @pnum: physical eraseblock number of the second logical eraseblock to
 226  * compare
 227  * @vid_hdr: volume identifier header of the second logical eraseblock
 228  *
 229  * This function compares 2 copies of a LEB and informs which one is newer. In
 230  * case of success this function returns a positive value, in case of failure, a
 231  * negative error code is returned. The success return codes use the following
 232  * bits:
 233  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 234  *       second PEB (described by @pnum and @vid_hdr);
 235  *     o bit 0 is set: the second PEB is newer;
 236  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 237  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 238  *     o bit 2 is cleared: the older LEB is not corrupted;
 239  *     o bit 2 is set: the older LEB is corrupted.
 240  */
 241 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 242                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 243 {
 244         void *buf;
 245         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 246         uint32_t data_crc, crc;
 247         struct ubi_vid_hdr *vh = NULL;
 248         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 249
 250         if (seb->sqnum == 0 && sqnum2 == 0) {
 251                 long long abs;
 252                 long long v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
 253
 254                 /*
 255                  * UBI constantly increases the logical eraseblock version
 256                  * number and it can overflow. Thus, we have to bear in mind
 257                  * that versions that are close to %0xFFFFFFFF are less then
 258                  * versions that are close to %0.
 259                  *
 260                  * The UBI WL sub-system guarantees that the number of pending
 261                  * tasks is not greater then %0x7FFFFFFF. So, if the difference
 262                  * between any two versions is greater or equivalent to
 263                  * %0x7FFFFFFF, there was an overflow and the logical
 264                  * eraseblock with lower version is actually newer then the one
 265                  * with higher version.
 266                  *
 267                  * FIXME: but this is anyway obsolete and will be removed at
 268                  * some point.
 269                  */
 270                 dbg_bld("using old crappy leb_ver stuff");
 271
 272                 if (v1 == v2) {
 273                         ubi_err("PEB %d and PEB %d have the same version %lld",
 274                                 seb->pnum, pnum, v1);
 275                         return -EINVAL;
 276                 }
 277
 278                 abs = v1 - v2;
 279                 if (abs < 0)
 280                         abs = -abs;
 281
 282                 if (abs < 0x7FFFFFFF)
 283                         /* Non-overflow situation */
 284                         second_is_newer = (v2 > v1);
 285                 else
 286                         second_is_newer = (v2 < v1);
 287         } else
 288                 /* Obviously the LEB with lower sequence counter is older */
 289                 second_is_newer = sqnum2 > seb->sqnum;
 290
 291         /*
 292          * Now we know which copy is newer. If the copy flag of the PEB with
 293          * newer version is not set, then we just return, otherwise we have to
 294          * check data CRC. For the second PEB we already have the VID header,
 295          * for the first one - we'll need to re-read it from flash.
 296          *
 297          * FIXME: this may be optimized so that we wouldn't read twice.
 298          */
 299
 300         if (second_is_newer) {
 301                 if (!vid_hdr->copy_flag) {
 302                         /* It is not a copy, so it is newer */
 303                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 304                                 pnum);
 305                         return 1;
 306                 }
 307         } else {
 308                 pnum = seb->pnum;
 309
 310                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 311                 if (!vh)
 312                         return -ENOMEM;
 313
 314                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 315                 if (err) {
 316                         if (err == UBI_IO_BITFLIPS)
 317                                 bitflips = 1;
 318                         else {
 319                                 dbg_err("VID of PEB %d header is bad, but it "
 320                                         "was OK earlier", pnum);
 321                                 if (err > 0)
 322                                         err = -EIO;
 323
 324                                 goto out_free_vidh;
 325                         }
 326                 }
 327
 328                 if (!vh->copy_flag) {
 329                         /* It is not a copy, so it is newer */
 330                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 331                                 pnum);
 332                         err = bitflips << 1;
 333                         goto out_free_vidh;
 334                 }
 335
 336                 vid_hdr = vh;
 337         }
 338
 339         /* Read the data of the copy and check the CRC */
 340
 341         len = be32_to_cpu(vid_hdr->data_size);
 342         buf = vmalloc(len);
 343         if (!buf) {
 344                 err = -ENOMEM;
 345                 goto out_free_vidh;
 346         }
 347
 348         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 349         if (err && err != UBI_IO_BITFLIPS)
 350                 goto out_free_buf;
 351
 352         data_crc = be32_to_cpu(vid_hdr->data_crc);
 353         crc = crc32(UBI_CRC32_INIT, buf, len);
 354         if (crc != data_crc) {
 355                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 356                         pnum, crc, data_crc);
 357                 corrupted = 1;
 358                 bitflips = 0;
 359                 second_is_newer = !second_is_newer;
 360         } else {
 361                 dbg_bld("PEB %d CRC is OK", pnum);
 362                 bitflips = !!err;
 363         }
 364
 365         vfree(buf);
 366         ubi_free_vid_hdr(ubi, vh);
 367
 368         if (second_is_newer)
 369                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 370         else
 371                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 372
 373         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 374
 375 out_free_buf:
 376         vfree(buf);
 377 out_free_vidh:
 378         ubi_free_vid_hdr(ubi, vh);
 379         return err;
 380 }
 381
 382 /**
 383  * ubi_scan_add_used - add information about a physical eraseblock to the
 384  * scanning information.
 385  * @ubi: UBI device description object
 386  * @si: scanning information
 387  * @pnum: the physical eraseblock number
 388  * @ec: erase counter
 389  * @vid_hdr: the volume identifier header
 390  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 391  *
 392  * This function adds information about a used physical eraseblock to the
 393  * 'used' tree of the corresponding volume. The function is rather complex
 394  * because it has to handle cases when this is not the first physical
 395  * eraseblock belonging to the same logical eraseblock, and the newer one has
 396  * to be picked, while the older one has to be dropped. This function returns
 397  * zero in case of success and a negative error code in case of failure.
 398  */
 399 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 400                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 401                       int bitflips)
 402 {
 403         int err, vol_id, lnum;
 404         uint32_t leb_ver;
 405         unsigned long long sqnum;
 406         struct ubi_scan_volume *sv;
 407         struct ubi_scan_leb *seb;
 408         struct rb_node **p, *parent = NULL;
 409
 410         vol_id = be32_to_cpu(vid_hdr->vol_id);
 411         lnum = be32_to_cpu(vid_hdr->lnum);
 412         sqnum = be64_to_cpu(vid_hdr->sqnum);
 413         leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 414
 415         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 416                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 417
 418         sv = add_volume(si, vol_id, pnum, vid_hdr);
 419         if (IS_ERR(sv) < 0)
 420                 return PTR_ERR(sv);
 421
 422         if (si->max_sqnum < sqnum)
 423                 si->max_sqnum = sqnum;
 424
 425         /*
 426          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 427          * if this is the first instance of this logical eraseblock or not.
 428          */
 429         p = &sv->root.rb_node;
 430         while (*p) {
 431                 int cmp_res;
 432
 433                 parent = *p;
 434                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 435                 if (lnum != seb->lnum) {
 436                         if (lnum < seb->lnum)
 437                                 p = &(*p)->rb_left;
 438                         else
 439                                 p = &(*p)->rb_right;
 440                         continue;
 441                 }
 442
 443                 /*
 444                  * There is already a physical eraseblock describing the same
 445                  * logical eraseblock present.
 446                  */
 447
 448                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 449                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 450                         seb->leb_ver, seb->ec);
 451
 452                 /*
 453                  * Make sure that the logical eraseblocks have different
 454                  * versions. Otherwise the image is bad.
 455                  */
 456                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 457                         ubi_err("two LEBs with same version %u", leb_ver);
 458                         ubi_dbg_dump_seb(seb, 0);
 459                         ubi_dbg_dump_vid_hdr(vid_hdr);
 460                         return -EINVAL;
 461                 }
 462
 463                 /*
 464                  * Make sure that the logical eraseblocks have different
 465                  * sequence numbers. Otherwise the image is bad.
 466                  *
 467                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 468                  */
 469                 if (seb->sqnum == sqnum && sqnum != 0) {
 470                         ubi_err("two LEBs with same sequence number %llu",
 471                                 sqnum);
 472                         ubi_dbg_dump_seb(seb, 0);
 473                         ubi_dbg_dump_vid_hdr(vid_hdr);
 474                         return -EINVAL;
 475                 }
 476
 477                 /*
 478                  * Now we have to drop the older one and preserve the newer
 479                  * one.
 480                  */
 481                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 482                 if (cmp_res < 0)
 483                         return cmp_res;
 484
 485                 if (cmp_res & 1) {
 486                         /*
 487                          * This logical eraseblock is newer then the one
 488                          * found earlier.
 489                          */
 490                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 491                         if (err)
 492                                 return err;
 493
 494                         if (cmp_res & 4)
 495                                 err = add_to_list(si, seb->pnum, seb->ec,
 496                                                   &si->corr);
 497                         else
 498                                 err = add_to_list(si, seb->pnum, seb->ec,
 499                                                   &si->erase);
 500                         if (err)
 501                                 return err;
 502
 503                         seb->ec = ec;
 504                         seb->pnum = pnum;
 505                         seb->scrub = ((cmp_res & 2) || bitflips);
 506                         seb->sqnum = sqnum;
 507                         seb->leb_ver = leb_ver;
 508
 509                         if (sv->highest_lnum == lnum)
 510                                 sv->last_data_size =
 511                                         be32_to_cpu(vid_hdr->data_size);
 512
 513                         return 0;
 514                 } else {
 515                         /*
 516                          * This logical eraseblock is older then the one found
 517                          * previously.
 518                          */
 519                         if (cmp_res & 4)
 520                                 return add_to_list(si, pnum, ec, &si->corr);
 521                         else
 522                                 return add_to_list(si, pnum, ec, &si->erase);
 523                 }
 524         }
 525
 526         /*
 527          * We've met this logical eraseblock for the first time, add it to the
 528          * scanning information.
 529          */
 530
 531         err = validate_vid_hdr(vid_hdr, sv, pnum);
 532         if (err)
 533                 return err;
 534
 535         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 536         if (!seb)
 537                 return -ENOMEM;
 538
 539         seb->ec = ec;
 540         seb->pnum = pnum;
 541         seb->lnum = lnum;
 542         seb->sqnum = sqnum;
 543         seb->scrub = bitflips;
 544         seb->leb_ver = leb_ver;
 545
 546         if (sv->highest_lnum <= lnum) {
 547                 sv->highest_lnum = lnum;
 548                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 549         }
 550
 551         sv->leb_count += 1;
 552         rb_link_node(&seb->u.rb, parent, p);
 553         rb_insert_color(&seb->u.rb, &sv->root);
 554         return 0;
 555 }
 556
 557 /**
 558  * ubi_scan_find_sv - find information about a particular volume in the
 559  * scanning information.
 560  * @si: scanning information
 561  * @vol_id: the requested volume ID
 562  *
 563  * This function returns a pointer to the volume description or %NULL if there
 564  * are no data about this volume in the scanning information.
 565  */
 566 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 567                                          int vol_id)
 568 {
 569         struct ubi_scan_volume *sv;
 570         struct rb_node *p = si->volumes.rb_node;
 571
 572         while (p) {
 573                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 574
 575                 if (vol_id == sv->vol_id)
 576                         return sv;
 577
 578                 if (vol_id > sv->vol_id)
 579                         p = p->rb_left;
 580                 else
 581                         p = p->rb_right;
 582         }
 583
 584         return NULL;
 585 }
 586
 587 /**
 588  * ubi_scan_find_seb - find information about a particular logical
 589  * eraseblock in the volume scanning information.
 590  * @sv: a pointer to the volume scanning information
 591  * @lnum: the requested logical eraseblock
 592  *
 593  * This function returns a pointer to the scanning logical eraseblock or %NULL
 594  * if there are no data about it in the scanning volume information.
 595  */
 596 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 597                                        int lnum)
 598 {
 599         struct ubi_scan_leb *seb;
 600         struct rb_node *p = sv->root.rb_node;
 601
 602         while (p) {
 603                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 604
 605                 if (lnum == seb->lnum)
 606                         return seb;
 607
 608                 if (lnum > seb->lnum)
 609                         p = p->rb_left;
 610                 else
 611                         p = p->rb_right;
 612         }
 613
 614         return NULL;
 615 }
 616
 617 /**
 618  * ubi_scan_rm_volume - delete scanning information about a volume.
 619  * @si: scanning information
 620  * @sv: the volume scanning information to delete
 621  */
 622 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 623 {
 624         struct rb_node *rb;
 625         struct ubi_scan_leb *seb;
 626
 627         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 628
 629         while ((rb = rb_first(&sv->root))) {
 630                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 631                 rb_erase(&seb->u.rb, &sv->root);
 632                 list_add_tail(&seb->u.list, &si->erase);
 633         }
 634
 635         rb_erase(&sv->rb, &si->volumes);
 636         kfree(sv);
 637         si->vols_found -= 1;
 638 }
 639
 640 /**
 641  * ubi_scan_erase_peb - erase a physical eraseblock.
 642  * @ubi: UBI device description object
 643  * @si: scanning information
 644  * @pnum: physical eraseblock number to erase;
 645  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 646  *
 647  * This function erases physical eraseblock 'pnum', and writes the erase
 648  * counter header to it. This function should only be used on UBI device
 649  * initialization stages, when the EBA sub-system had not been yet initialized.
 650  * This function returns zero in case of success and a negative error code in
 651  * case of failure.
 652  */
 653 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 654                        int pnum, int ec)
 655 {
 656         int err;
 657         struct ubi_ec_hdr *ec_hdr;
 658
 659         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 660                 /*
 661                  * Erase counter overflow. Upgrade UBI and use 64-bit
 662                  * erase counters internally.
 663                  */
 664                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 665                 return -EINVAL;
 666         }
 667
 668         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 669         if (!ec_hdr)
 670                 return -ENOMEM;
 671
 672         ec_hdr->ec = cpu_to_be64(ec);
 673
 674         err = ubi_io_sync_erase(ubi, pnum, 0);
 675         if (err < 0)
 676                 goto out_free;
 677
 678         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 679
 680 out_free:
 681         kfree(ec_hdr);
 682         return err;
 683 }
 684
 685 /**
 686  * ubi_scan_get_free_peb - get a free physical eraseblock.
 687  * @ubi: UBI device description object
 688  * @si: scanning information
 689  *
 690  * This function returns a free physical eraseblock. It is supposed to be
 691  * called on the UBI initialization stages when the wear-leveling sub-system is
 692  * not initialized yet. This function picks a physical eraseblocks from one of
 693  * the lists, writes the EC header if it is needed, and removes it from the
 694  * list.
 695  *
 696  * This function returns scanning physical eraseblock information in case of
 697  * success and an error code in case of failure.
 698  */
 699 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 700                                            struct ubi_scan_info *si)
 701 {
 702         int err = 0, i;
 703         struct ubi_scan_leb *seb;
 704
 705         if (!list_empty(&si->free)) {
 706                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 707                 list_del(&seb->u.list);
 708                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 709                 return seb;
 710         }
 711
 712         for (i = 0; i < 2; i++) {
 713                 struct list_head *head;
 714                 struct ubi_scan_leb *tmp_seb;
 715
 716                 if (i == 0)
 717                         head = &si->erase;
 718                 else
 719                         head = &si->corr;
 720
 721                 /*
 722                  * We try to erase the first physical eraseblock from the @head
 723                  * list and pick it if we succeed, or try to erase the
 724                  * next one if not. And so forth. We don't want to take care
 725                  * about bad eraseblocks here - they'll be handled later.
 726                  */
 727                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 728                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 729                                 seb->ec = si->mean_ec;
 730
 731                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 732                         if (err)
 733                                 continue;
 734
 735                         seb->ec += 1;
 736                         list_del(&seb->u.list);
 737                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 738                         return seb;
 739                 }
 740         }
 741
 742         ubi_err("no eraseblocks found");
 743         return ERR_PTR(-ENOSPC);
 744 }
 745
 746 /**
 747  * process_eb - read UBI headers, check them and add corresponding data
 748  * to the scanning information.
 749  * @ubi: UBI device description object
 750  * @si: scanning information
 751  * @pnum: the physical eraseblock number
 752  *
 753  * This function returns a zero if the physical eraseblock was successfully
 754  * handled and a negative error code in case of failure.
 755  */
 756 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 757                       int pnum)
 758 {
 759         long long uninitialized_var(ec);
 760         int err, bitflips = 0, vol_id, ec_corr = 0;
 761
 762         dbg_bld("scan PEB %d", pnum);
 763
 764         /* Skip bad physical eraseblocks */
 765         err = ubi_io_is_bad(ubi, pnum);
 766         if (err < 0)
 767                 return err;
 768         else if (err) {
 769                 /*
 770                  * FIXME: this is actually duty of the I/O sub-system to
 771                  * initialize this, but MTD does not provide enough
 772                  * information.
 773                  */
 774                 si->bad_peb_count += 1;
 775                 return 0;
 776         }
 777
 778         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 779         if (err < 0)
 780                 return err;
 781         else if (err == UBI_IO_BITFLIPS)
 782                 bitflips = 1;
 783         else if (err == UBI_IO_PEB_EMPTY)
 784                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 785         else if (err == UBI_IO_BAD_EC_HDR) {
 786                 /*
 787                  * We have to also look at the VID header, possibly it is not
 788                  * corrupted. Set %bitflips flag in order to make this PEB be
 789                  * moved and EC be re-created.
 790                  */
 791                 ec_corr = 1;
 792                 ec = UBI_SCAN_UNKNOWN_EC;
 793                 bitflips = 1;
 794         }
 795
 796         si->is_empty = 0;
 797
 798         if (!ec_corr) {
 799                 /* Make sure UBI version is OK */
 800                 if (ech->version != UBI_VERSION) {
 801                         ubi_err("this UBI version is %d, image version is %d",
 802                                 UBI_VERSION, (int)ech->version);
 803                         return -EINVAL;
 804                 }
 805
 806                 ec = be64_to_cpu(ech->ec);
 807                 if (ec > UBI_MAX_ERASECOUNTER) {
 808                         /*
 809                          * Erase counter overflow. The EC headers have 64 bits
 810                          * reserved, but we anyway make use of only 31 bit
 811                          * values, as this seems to be enough for any existing
 812                          * flash. Upgrade UBI and use 64-bit erase counters
 813                          * internally.
 814                          */
 815                         ubi_err("erase counter overflow, max is %d",
 816                                 UBI_MAX_ERASECOUNTER);
 817                         ubi_dbg_dump_ec_hdr(ech);
 818                         return -EINVAL;
 819                 }
 820         }
 821
 822         /* OK, we've done with the EC header, let's look at the VID header */
 823
 824         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 825         if (err < 0)
 826                 return err;
 827         else if (err == UBI_IO_BITFLIPS)
 828                 bitflips = 1;
 829         else if (err == UBI_IO_BAD_VID_HDR ||
 830                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 831                 /* VID header is corrupted */
 832                 err = add_to_list(si, pnum, ec, &si->corr);
 833                 if (err)
 834                         return err;
 835                 goto adjust_mean_ec;
 836         } else if (err == UBI_IO_PEB_FREE) {
 837                 /* No VID header - the physical eraseblock is free */
 838                 err = add_to_list(si, pnum, ec, &si->free);
 839                 if (err)
 840                         return err;
 841                 goto adjust_mean_ec;
 842         }
 843
 844         vol_id = be32_to_cpu(vidh->vol_id);
 845         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 846                 int lnum = be32_to_cpu(vidh->lnum);
 847
 848                 /* Unsupported internal volume */
 849                 switch (vidh->compat) {
 850                 case UBI_COMPAT_DELETE:
 851                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 852                                 " found, remove it", vol_id, lnum);
 853                         err = add_to_list(si, pnum, ec, &si->corr);
 854                         if (err)
 855                                 return err;
 856                         break;
 857
 858                 case UBI_COMPAT_RO:
 859                         ubi_msg("read-only compatible internal volume %d:%d"
 860                                 " found, switch to read-only mode",
 861                                 vol_id, lnum);
 862                         ubi->ro_mode = 1;
 863                         break;
 864
 865                 case UBI_COMPAT_PRESERVE:
 866                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 867                                 " found", vol_id, lnum);
 868                         err = add_to_list(si, pnum, ec, &si->alien);
 869                         if (err)
 870                                 return err;
 871                         si->alien_peb_count += 1;
 872                         return 0;
 873
 874                 case UBI_COMPAT_REJECT:
 875                         ubi_err("incompatible internal volume %d:%d found",
 876                                 vol_id, lnum);
 877                         return -EINVAL;
 878                 }
 879         }
 880
 881         /* Both UBI headers seem to be fine */
 882         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 883         if (err)
 884                 return err;
 885
 886 adjust_mean_ec:
 887         if (!ec_corr) {
 888                 si->ec_sum += ec;
 889                 si->ec_count += 1;
 890                 if (ec > si->max_ec)
 891                         si->max_ec = ec;
 892                 if (ec < si->min_ec)
 893                         si->min_ec = ec;
 894         }
 895
 896         return 0;
 897 }
 898
 899 /**
 900  * ubi_scan - scan an MTD device.
 901  * @ubi: UBI device description object
 902  *
 903  * This function does full scanning of an MTD device and returns complete
 904  * information about it. In case of failure, an error code is returned.
 905  */
 906 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 907 {
 908         int err, pnum;
 909         struct rb_node *rb1, *rb2;
 910         struct ubi_scan_volume *sv;
 911         struct ubi_scan_leb *seb;
 912         struct ubi_scan_info *si;
 913
 914         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 915         if (!si)
 916                 return ERR_PTR(-ENOMEM);
 917
 918         INIT_LIST_HEAD(&si->corr);
 919         INIT_LIST_HEAD(&si->free);
 920         INIT_LIST_HEAD(&si->erase);
 921         INIT_LIST_HEAD(&si->alien);
 922         si->volumes = RB_ROOT;
 923         si->is_empty = 1;
 924
 925         err = -ENOMEM;
 926         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 927         if (!ech)
 928                 goto out_si;
 929
 930         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 931         if (!vidh)
 932                 goto out_ech;
 933
 934         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 935                 cond_resched();
 936
 937                 dbg_gen("process PEB %d", pnum);
 938                 err = process_eb(ubi, si, pnum);
 939                 if (err < 0)
 940                         goto out_vidh;
 941         }
 942
 943         dbg_msg("scanning is finished");
 944
 945         /* Calculate mean erase counter */
 946         if (si->ec_count) {
 947                 do_div(si->ec_sum, si->ec_count);
 948                 si->mean_ec = si->ec_sum;
 949         }
 950
 951         if (si->is_empty)
 952                 ubi_msg("empty MTD device detected");
 953
 954         /*
 955          * In case of unknown erase counter we use the mean erase counter
 956          * value.
 957          */
 958         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 959                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 960                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 961                                 seb->ec = si->mean_ec;
 962         }
 963
 964         list_for_each_entry(seb, &si->free, u.list) {
 965                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 966                         seb->ec = si->mean_ec;
 967         }
 968
 969         list_for_each_entry(seb, &si->corr, u.list)
 970                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 971                         seb->ec = si->mean_ec;
 972
 973         list_for_each_entry(seb, &si->erase, u.list)
 974                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 975                         seb->ec = si->mean_ec;
 976
 977         err = paranoid_check_si(ubi, si);
 978         if (err) {
 979                 if (err > 0)
 980                         err = -EINVAL;
 981                 goto out_vidh;
 982         }
 983
 984         ubi_free_vid_hdr(ubi, vidh);
 985         kfree(ech);
 986
 987         return si;
 988
 989 out_vidh:
 990         ubi_free_vid_hdr(ubi, vidh);
 991 out_ech:
 992         kfree(ech);
 993 out_si:
 994         ubi_scan_destroy_si(si);
 995         return ERR_PTR(err);
 996 }
 997
 998 /**
 999  * destroy_sv - free the scanning volume information
1000  * @sv: scanning volume information
1001  *
1002  * This function destroys the volume RB-tree (@sv->root) and the scanning
1003  * volume information.
1004  */
1005 static void destroy_sv(struct ubi_scan_volume *sv)
1006 {
1007         struct ubi_scan_leb *seb;
1008         struct rb_node *this = sv->root.rb_node;
1009
1010         while (this) {
1011                 if (this->rb_left)
1012                         this = this->rb_left;
1013                 else if (this->rb_right)
1014                         this = this->rb_right;
1015                 else {
1016                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1017                         this = rb_parent(this);
1018                         if (this) {
1019                                 if (this->rb_left == &seb->u.rb)
1020                                         this->rb_left = NULL;
1021                                 else
1022                                         this->rb_right = NULL;
1023                         }
1024
1025                         kfree(seb);
1026                 }
1027         }
1028         kfree(sv);
1029 }
1030
1031 /**
1032  * ubi_scan_destroy_si - destroy scanning information.
1033  * @si: scanning information
1034  */
1035 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1036 {
1037         struct ubi_scan_leb *seb, *seb_tmp;
1038         struct ubi_scan_volume *sv;
1039         struct rb_node *rb;
1040
1041         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1042                 list_del(&seb->u.list);
1043                 kfree(seb);
1044         }
1045         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1046                 list_del(&seb->u.list);
1047                 kfree(seb);
1048         }
1049         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1050                 list_del(&seb->u.list);
1051                 kfree(seb);
1052         }
1053         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1054                 list_del(&seb->u.list);
1055                 kfree(seb);
1056         }
1057
1058         /* Destroy the volume RB-tree */
1059         rb = si->volumes.rb_node;
1060         while (rb) {
1061                 if (rb->rb_left)
1062                         rb = rb->rb_left;
1063                 else if (rb->rb_right)
1064                         rb = rb->rb_right;
1065                 else {
1066                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1067
1068                         rb = rb_parent(rb);
1069                         if (rb) {
1070                                 if (rb->rb_left == &sv->rb)
1071                                         rb->rb_left = NULL;
1072                                 else
1073                                         rb->rb_right = NULL;
1074                         }
1075
1076                         destroy_sv(sv);
1077                 }
1078         }
1079
1080         kfree(si);
1081 }
1082
1083 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1084
1085 /**
1086  * paranoid_check_si - check if the scanning information is correct and
1087  * consistent.
1088  * @ubi: UBI device description object
1089  * @si: scanning information
1090  *
1091  * This function returns zero if the scanning information is all right, %1 if
1092  * not and a negative error code if an error occurred.
1093  */
1094 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1095 {
1096         int pnum, err, vols_found = 0;
1097         struct rb_node *rb1, *rb2;
1098         struct ubi_scan_volume *sv;
1099         struct ubi_scan_leb *seb, *last_seb;
1100         uint8_t *buf;
1101
1102         /*
1103          * At first, check that scanning information is OK.
1104          */
1105         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1106                 int leb_count = 0;
1107
1108                 cond_resched();
1109
1110                 vols_found += 1;
1111
1112                 if (si->is_empty) {
1113                         ubi_err("bad is_empty flag");
1114                         goto bad_sv;
1115                 }
1116
1117                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1118                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1119                     sv->data_pad < 0 || sv->last_data_size < 0) {
1120                         ubi_err("negative values");
1121                         goto bad_sv;
1122                 }
1123
1124                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1125                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1126                         ubi_err("bad vol_id");
1127                         goto bad_sv;
1128                 }
1129
1130                 if (sv->vol_id > si->highest_vol_id) {
1131                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1132                                 si->highest_vol_id, sv->vol_id);
1133                         goto out;
1134                 }
1135
1136                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1137                     sv->vol_type != UBI_STATIC_VOLUME) {
1138                         ubi_err("bad vol_type");
1139                         goto bad_sv;
1140                 }
1141
1142                 if (sv->data_pad > ubi->leb_size / 2) {
1143                         ubi_err("bad data_pad");
1144                         goto bad_sv;
1145                 }
1146
1147                 last_seb = NULL;
1148                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1149                         cond_resched();
1150
1151                         last_seb = seb;
1152                         leb_count += 1;
1153
1154                         if (seb->pnum < 0 || seb->ec < 0) {
1155                                 ubi_err("negative values");
1156                                 goto bad_seb;
1157                         }
1158
1159                         if (seb->ec < si->min_ec) {
1160                                 ubi_err("bad si->min_ec (%d), %d found",
1161                                         si->min_ec, seb->ec);
1162                                 goto bad_seb;
1163                         }
1164
1165                         if (seb->ec > si->max_ec) {
1166                                 ubi_err("bad si->max_ec (%d), %d found",
1167                                         si->max_ec, seb->ec);
1168                                 goto bad_seb;
1169                         }
1170
1171                         if (seb->pnum >= ubi->peb_count) {
1172                                 ubi_err("too high PEB number %d, total PEBs %d",
1173                                         seb->pnum, ubi->peb_count);
1174                                 goto bad_seb;
1175                         }
1176
1177                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1178                                 if (seb->lnum >= sv->used_ebs) {
1179                                         ubi_err("bad lnum or used_ebs");
1180                                         goto bad_seb;
1181                                 }
1182                         } else {
1183                                 if (sv->used_ebs != 0) {
1184                                         ubi_err("non-zero used_ebs");
1185                                         goto bad_seb;
1186                                 }
1187                         }
1188
1189                         if (seb->lnum > sv->highest_lnum) {
1190                                 ubi_err("incorrect highest_lnum or lnum");
1191                                 goto bad_seb;
1192                         }
1193                 }
1194
1195                 if (sv->leb_count != leb_count) {
1196                         ubi_err("bad leb_count, %d objects in the tree",
1197                                 leb_count);
1198                         goto bad_sv;
1199                 }
1200
1201                 if (!last_seb)
1202                         continue;
1203
1204                 seb = last_seb;
1205
1206                 if (seb->lnum != sv->highest_lnum) {
1207                         ubi_err("bad highest_lnum");
1208                         goto bad_seb;
1209                 }
1210         }
1211
1212         if (vols_found != si->vols_found) {
1213                 ubi_err("bad si->vols_found %d, should be %d",
1214                         si->vols_found, vols_found);
1215                 goto out;
1216         }
1217
1218         /* Check that scanning information is correct */
1219         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1220                 last_seb = NULL;
1221                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1222                         int vol_type;
1223
1224                         cond_resched();
1225
1226                         last_seb = seb;
1227
1228                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1229                         if (err && err != UBI_IO_BITFLIPS) {
1230                                 ubi_err("VID header is not OK (%d)", err);
1231                                 if (err > 0)
1232                                         err = -EIO;
1233                                 return err;
1234                         }
1235
1236                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1237                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1238                         if (sv->vol_type != vol_type) {
1239                                 ubi_err("bad vol_type");
1240                                 goto bad_vid_hdr;
1241                         }
1242
1243                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1244                                 ubi_err("bad sqnum %llu", seb->sqnum);
1245                                 goto bad_vid_hdr;
1246                         }
1247
1248                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1249                                 ubi_err("bad vol_id %d", sv->vol_id);
1250                                 goto bad_vid_hdr;
1251                         }
1252
1253                         if (sv->compat != vidh->compat) {
1254                                 ubi_err("bad compat %d", vidh->compat);
1255                                 goto bad_vid_hdr;
1256                         }
1257
1258                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1259                                 ubi_err("bad lnum %d", seb->lnum);
1260                                 goto bad_vid_hdr;
1261                         }
1262
1263                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1264                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1265                                 goto bad_vid_hdr;
1266                         }
1267
1268                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1269                                 ubi_err("bad data_pad %d", sv->data_pad);
1270                                 goto bad_vid_hdr;
1271                         }
1272
1273                         if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
1274                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1275                                 goto bad_vid_hdr;
1276                         }
1277                 }
1278
1279                 if (!last_seb)
1280                         continue;
1281
1282                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1283                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1284                         goto bad_vid_hdr;
1285                 }
1286
1287                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1288                         ubi_err("bad last_data_size %d", sv->last_data_size);
1289                         goto bad_vid_hdr;
1290                 }
1291         }
1292
1293         /*
1294          * Make sure that all the physical eraseblocks are in one of the lists
1295          * or trees.
1296          */
1297         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1298         if (!buf)
1299                 return -ENOMEM;
1300
1301         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1302                 err = ubi_io_is_bad(ubi, pnum);
1303                 if (err < 0) {
1304                         kfree(buf);
1305                         return err;
1306                 } else if (err)
1307                         buf[pnum] = 1;
1308         }
1309
1310         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1311                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1312                         buf[seb->pnum] = 1;
1313
1314         list_for_each_entry(seb, &si->free, u.list)
1315                 buf[seb->pnum] = 1;
1316
1317         list_for_each_entry(seb, &si->corr, u.list)
1318                 buf[seb->pnum] = 1;
1319
1320         list_for_each_entry(seb, &si->erase, u.list)
1321                 buf[seb->pnum] = 1;
1322
1323         list_for_each_entry(seb, &si->alien, u.list)
1324                 buf[seb->pnum] = 1;
1325
1326         err = 0;
1327         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1328                 if (!buf[pnum]) {
1329                         ubi_err("PEB %d is not referred", pnum);
1330                         err = 1;
1331                 }
1332
1333         kfree(buf);
1334         if (err)
1335                 goto out;
1336         return 0;
1337
1338 bad_seb:
1339         ubi_err("bad scanning information about LEB %d", seb->lnum);
1340         ubi_dbg_dump_seb(seb, 0);
1341         ubi_dbg_dump_sv(sv);
1342         goto out;
1343
1344 bad_sv:
1345         ubi_err("bad scanning information about volume %d", sv->vol_id);
1346         ubi_dbg_dump_sv(sv);
1347         goto out;
1348
1349 bad_vid_hdr:
1350         ubi_err("bad scanning information about volume %d", sv->vol_id);
1351         ubi_dbg_dump_sv(sv);
1352         ubi_dbg_dump_vid_hdr(vidh);
1353
1354 out:
1355         ubi_dbg_dump_stack();
1356         return 1;
1357 }
1358
1359 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */