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 = be32_to_cpu(vid_hdr->vol_id);
 136         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 137         int data_pad = be32_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 == be32_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         sv->vol_id = vol_id;
 226         sv->root = RB_ROOT;
 227         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 228         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 229         sv->compat = vid_hdr->compat;
 230         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 231                                                             : UBI_STATIC_VOLUME;
 232         if (vol_id > si->highest_vol_id)
 233                 si->highest_vol_id = vol_id;
 234
 235         rb_link_node(&sv->rb, parent, p);
 236         rb_insert_color(&sv->rb, &si->volumes);
 237         si->vols_found += 1;
 238         dbg_bld("added volume %d", vol_id);
 239         return sv;
 240 }
 241
 242 /**
 243  * compare_lebs - find out which logical eraseblock is newer.
 244  * @ubi: UBI device description object
 245  * @seb: first logical eraseblock to compare
 246  * @pnum: physical eraseblock number of the second logical eraseblock to
 247  * compare
 248  * @vid_hdr: volume identifier header of the second logical eraseblock
 249  *
 250  * This function compares 2 copies of a LEB and informs which one is newer. In
 251  * case of success this function returns a positive value, in case of failure, a
 252  * negative error code is returned. The success return codes use the following
 253  * bits:
 254  *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
 255  *       second PEB (described by @pnum and @vid_hdr);
 256  *     o bit 0 is set: the second PEB is newer;
 257  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 258  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 259  *     o bit 2 is cleared: the older LEB is not corrupted;
 260  *     o bit 2 is set: the older LEB is corrupted.
 261  */
 262 static int compare_lebs(const struct ubi_device *ubi,
 263                         const struct ubi_scan_leb *seb, int pnum,
 264                         const struct ubi_vid_hdr *vid_hdr)
 265 {
 266         void *buf;
 267         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 268         uint32_t data_crc, crc;
 269         struct ubi_vid_hdr *vidh = NULL;
 270         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 271
 272         if (seb->sqnum == 0 && sqnum2 == 0) {
 273                 long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
 274
 275                 /*
 276                  * UBI constantly increases the logical eraseblock version
 277                  * number and it can overflow. Thus, we have to bear in mind
 278                  * that versions that are close to %0xFFFFFFFF are less then
 279                  * versions that are close to %0.
 280                  *
 281                  * The UBI WL unit guarantees that the number of pending tasks
 282                  * is not greater then %0x7FFFFFFF. So, if the difference
 283                  * between any two versions is greater or equivalent to
 284                  * %0x7FFFFFFF, there was an overflow and the logical
 285                  * eraseblock with lower version is actually newer then the one
 286                  * with higher version.
 287                  *
 288                  * FIXME: but this is anyway obsolete and will be removed at
 289                  * some point.
 290                  */
 291
 292                 dbg_bld("using old crappy leb_ver stuff");
 293
 294                 abs = v1 - v2;
 295                 if (abs < 0)
 296                         abs = -abs;
 297
 298                 if (abs < 0x7FFFFFFF)
 299                         /* Non-overflow situation */
 300                         second_is_newer = (v2 > v1);
 301                 else
 302                         second_is_newer = (v2 < v1);
 303         } else
 304                 /* Obviously the LEB with lower sequence counter is older */
 305                 second_is_newer = sqnum2 > seb->sqnum;
 306
 307         /*
 308          * Now we know which copy is newer. If the copy flag of the PEB with
 309          * newer version is not set, then we just return, otherwise we have to
 310          * check data CRC. For the second PEB we already have the VID header,
 311          * for the first one - we'll need to re-read it from flash.
 312          *
 313          * FIXME: this may be optimized so that we wouldn't read twice.
 314          */
 315
 316         if (second_is_newer) {
 317                 if (!vid_hdr->copy_flag) {
 318                         /* It is not a copy, so it is newer */
 319                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 320                                 pnum);
 321                         return 1;
 322                 }
 323         } else {
 324                 pnum = seb->pnum;
 325
 326                 vidh = ubi_zalloc_vid_hdr(ubi);
 327                 if (!vidh)
 328                         return -ENOMEM;
 329
 330                 err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 331                 if (err) {
 332                         if (err == UBI_IO_BITFLIPS)
 333                                 bitflips = 1;
 334                         else {
 335                                 dbg_err("VID of PEB %d header is bad, but it "
 336                                         "was OK earlier", pnum);
 337                                 if (err > 0)
 338                                         err = -EIO;
 339
 340                                 goto out_free_vidh;
 341                         }
 342                 }
 343
 344                 if (!vidh->copy_flag) {
 345                         /* It is not a copy, so it is newer */
 346                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 347                                 pnum);
 348                         err = bitflips << 1;
 349                         goto out_free_vidh;
 350                 }
 351
 352                 vid_hdr = vidh;
 353         }
 354
 355         /* Read the data of the copy and check the CRC */
 356
 357         len = be32_to_cpu(vid_hdr->data_size);
 358         buf = vmalloc(len);
 359         if (!buf) {
 360                 err = -ENOMEM;
 361                 goto out_free_vidh;
 362         }
 363
 364         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 365         if (err && err != UBI_IO_BITFLIPS)
 366                 goto out_free_buf;
 367
 368         data_crc = be32_to_cpu(vid_hdr->data_crc);
 369         crc = crc32(UBI_CRC32_INIT, buf, len);
 370         if (crc != data_crc) {
 371                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 372                         pnum, crc, data_crc);
 373                 corrupted = 1;
 374                 bitflips = 0;
 375                 second_is_newer = !second_is_newer;
 376         } else {
 377                 dbg_bld("PEB %d CRC is OK", pnum);
 378                 bitflips = !!err;
 379         }
 380
 381         vfree(buf);
 382         ubi_free_vid_hdr(ubi, vidh);
 383
 384         if (second_is_newer)
 385                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 386         else
 387                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 388
 389         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 390
 391 out_free_buf:
 392         vfree(buf);
 393 out_free_vidh:
 394         ubi_free_vid_hdr(ubi, vidh);
 395         ubi_assert(err < 0);
 396         return err;
 397 }
 398
 399 /**
 400  * ubi_scan_add_used - add information about a physical eraseblock to the
 401  * scanning information.
 402  * @ubi: UBI device description object
 403  * @si: scanning information
 404  * @pnum: the physical eraseblock number
 405  * @ec: erase counter
 406  * @vid_hdr: the volume identifier header
 407  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 408  *
 409  * This function adds information about a used physical eraseblock to the
 410  * 'used' tree of the corresponding volume. The function is rather complex
 411  * because it has to handle cases when this is not the first physical
 412  * eraseblock belonging to the same logical eraseblock, and the newer one has
 413  * to be picked, while the older one has to be dropped. This function returns
 414  * zero in case of success and a negative error code in case of failure.
 415  */
 416 int ubi_scan_add_used(const struct ubi_device *ubi, struct ubi_scan_info *si,
 417                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 418                       int bitflips)
 419 {
 420         int err, vol_id, lnum;
 421         uint32_t leb_ver;
 422         unsigned long long sqnum;
 423         struct ubi_scan_volume *sv;
 424         struct ubi_scan_leb *seb;
 425         struct rb_node **p, *parent = NULL;
 426
 427         vol_id = be32_to_cpu(vid_hdr->vol_id);
 428         lnum = be32_to_cpu(vid_hdr->lnum);
 429         sqnum = be64_to_cpu(vid_hdr->sqnum);
 430         leb_ver = be32_to_cpu(vid_hdr->leb_ver);
 431
 432         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
 433                 pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
 434
 435         sv = add_volume(si, vol_id, pnum, vid_hdr);
 436         if (IS_ERR(sv) < 0)
 437                 return PTR_ERR(sv);
 438
 439         if (si->max_sqnum < sqnum)
 440                 si->max_sqnum = sqnum;
 441
 442         /*
 443          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 444          * if this is the first instance of this logical eraseblock or not.
 445          */
 446         p = &sv->root.rb_node;
 447         while (*p) {
 448                 int cmp_res;
 449
 450                 parent = *p;
 451                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 452                 if (lnum != seb->lnum) {
 453                         if (lnum < seb->lnum)
 454                                 p = &(*p)->rb_left;
 455                         else
 456                                 p = &(*p)->rb_right;
 457                         continue;
 458                 }
 459
 460                 /*
 461                  * There is already a physical eraseblock describing the same
 462                  * logical eraseblock present.
 463                  */
 464
 465                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 466                         "LEB ver %u, EC %d", seb->pnum, seb->sqnum,
 467                         seb->leb_ver, seb->ec);
 468
 469                 /*
 470                  * Make sure that the logical eraseblocks have different
 471                  * versions. Otherwise the image is bad.
 472                  */
 473                 if (seb->leb_ver == leb_ver && leb_ver != 0) {
 474                         ubi_err("two LEBs with same version %u", leb_ver);
 475                         ubi_dbg_dump_seb(seb, 0);
 476                         ubi_dbg_dump_vid_hdr(vid_hdr);
 477                         return -EINVAL;
 478                 }
 479
 480                 /*
 481                  * Make sure that the logical eraseblocks have different
 482                  * sequence numbers. Otherwise the image is bad.
 483                  *
 484                  * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
 485                  */
 486                 if (seb->sqnum == sqnum && sqnum != 0) {
 487                         ubi_err("two LEBs with same sequence number %llu",
 488                                 sqnum);
 489                         ubi_dbg_dump_seb(seb, 0);
 490                         ubi_dbg_dump_vid_hdr(vid_hdr);
 491                         return -EINVAL;
 492                 }
 493
 494                 /*
 495                  * Now we have to drop the older one and preserve the newer
 496                  * one.
 497                  */
 498                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 499                 if (cmp_res < 0)
 500                         return cmp_res;
 501
 502                 if (cmp_res & 1) {
 503                         /*
 504                          * This logical eraseblock is newer then the one
 505                          * found earlier.
 506                          */
 507                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 508                         if (err)
 509                                 return err;
 510
 511                         if (cmp_res & 4)
 512                                 err = add_to_list(si, seb->pnum, seb->ec,
 513                                                   &si->corr);
 514                         else
 515                                 err = add_to_list(si, seb->pnum, seb->ec,
 516                                                   &si->erase);
 517                         if (err)
 518                                 return err;
 519
 520                         seb->ec = ec;
 521                         seb->pnum = pnum;
 522                         seb->scrub = ((cmp_res & 2) || bitflips);
 523                         seb->sqnum = sqnum;
 524                         seb->leb_ver = leb_ver;
 525
 526                         if (sv->highest_lnum == lnum)
 527                                 sv->last_data_size =
 528                                         be32_to_cpu(vid_hdr->data_size);
 529
 530                         return 0;
 531                 } else {
 532                         /*
 533                          * This logical eraseblock is older then the one found
 534                          * previously.
 535                          */
 536                         if (cmp_res & 4)
 537                                 return add_to_list(si, pnum, ec, &si->corr);
 538                         else
 539                                 return add_to_list(si, pnum, ec, &si->erase);
 540                 }
 541         }
 542
 543         /*
 544          * We've met this logical eraseblock for the first time, add it to the
 545          * scanning information.
 546          */
 547
 548         err = validate_vid_hdr(vid_hdr, sv, pnum);
 549         if (err)
 550                 return err;
 551
 552         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 553         if (!seb)
 554                 return -ENOMEM;
 555
 556         seb->ec = ec;
 557         seb->pnum = pnum;
 558         seb->lnum = lnum;
 559         seb->sqnum = sqnum;
 560         seb->scrub = bitflips;
 561         seb->leb_ver = leb_ver;
 562
 563         if (sv->highest_lnum <= lnum) {
 564                 sv->highest_lnum = lnum;
 565                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 566         }
 567
 568         sv->leb_count += 1;
 569         rb_link_node(&seb->u.rb, parent, p);
 570         rb_insert_color(&seb->u.rb, &sv->root);
 571         return 0;
 572 }
 573
 574 /**
 575  * ubi_scan_find_sv - find information about a particular volume in the
 576  * scanning information.
 577  * @si: scanning information
 578  * @vol_id: the requested volume ID
 579  *
 580  * This function returns a pointer to the volume description or %NULL if there
 581  * are no data about this volume in the scanning information.
 582  */
 583 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 584                                          int vol_id)
 585 {
 586         struct ubi_scan_volume *sv;
 587         struct rb_node *p = si->volumes.rb_node;
 588
 589         while (p) {
 590                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 591
 592                 if (vol_id == sv->vol_id)
 593                         return sv;
 594
 595                 if (vol_id > sv->vol_id)
 596                         p = p->rb_left;
 597                 else
 598                         p = p->rb_right;
 599         }
 600
 601         return NULL;
 602 }
 603
 604 /**
 605  * ubi_scan_find_seb - find information about a particular logical
 606  * eraseblock in the volume scanning information.
 607  * @sv: a pointer to the volume scanning information
 608  * @lnum: the requested logical eraseblock
 609  *
 610  * This function returns a pointer to the scanning logical eraseblock or %NULL
 611  * if there are no data about it in the scanning volume information.
 612  */
 613 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 614                                        int lnum)
 615 {
 616         struct ubi_scan_leb *seb;
 617         struct rb_node *p = sv->root.rb_node;
 618
 619         while (p) {
 620                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 621
 622                 if (lnum == seb->lnum)
 623                         return seb;
 624
 625                 if (lnum > seb->lnum)
 626                         p = p->rb_left;
 627                 else
 628                         p = p->rb_right;
 629         }
 630
 631         return NULL;
 632 }
 633
 634 /**
 635  * ubi_scan_rm_volume - delete scanning information about a volume.
 636  * @si: scanning information
 637  * @sv: the volume scanning information to delete
 638  */
 639 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 640 {
 641         struct rb_node *rb;
 642         struct ubi_scan_leb *seb;
 643
 644         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 645
 646         while ((rb = rb_first(&sv->root))) {
 647                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 648                 rb_erase(&seb->u.rb, &sv->root);
 649                 list_add_tail(&seb->u.list, &si->erase);
 650         }
 651
 652         rb_erase(&sv->rb, &si->volumes);
 653         kfree(sv);
 654         si->vols_found -= 1;
 655 }
 656
 657 /**
 658  * ubi_scan_erase_peb - erase a physical eraseblock.
 659  * @ubi: UBI device description object
 660  * @si: scanning information
 661  * @pnum: physical eraseblock number to erase;
 662  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 663  *
 664  * This function erases physical eraseblock 'pnum', and writes the erase
 665  * counter header to it. This function should only be used on UBI device
 666  * initialization stages, when the EBA unit had not been yet initialized. This
 667  * function returns zero in case of success and a negative error code in case
 668  * of failure.
 669  */
 670 int ubi_scan_erase_peb(const struct ubi_device *ubi,
 671                        const struct ubi_scan_info *si, int pnum, int ec)
 672 {
 673         int err;
 674         struct ubi_ec_hdr *ec_hdr;
 675
 676         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 677         if (!ec_hdr)
 678                 return -ENOMEM;
 679
 680         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 681                 /*
 682                  * Erase counter overflow. Upgrade UBI and use 64-bit
 683                  * erase counters internally.
 684                  */
 685                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 686                 return -EINVAL;
 687         }
 688
 689         ec_hdr->ec = cpu_to_be64(ec);
 690
 691         err = ubi_io_sync_erase(ubi, pnum, 0);
 692         if (err < 0)
 693                 goto out_free;
 694
 695         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 696
 697 out_free:
 698         kfree(ec_hdr);
 699         return err;
 700 }
 701
 702 /**
 703  * ubi_scan_get_free_peb - get a free physical eraseblock.
 704  * @ubi: UBI device description object
 705  * @si: scanning information
 706  *
 707  * This function returns a free physical eraseblock. It is supposed to be
 708  * called on the UBI initialization stages when the wear-leveling unit is not
 709  * initialized yet. This function picks a physical eraseblocks from one of the
 710  * lists, writes the EC header if it is needed, and removes it from the list.
 711  *
 712  * This function returns scanning physical eraseblock information in case of
 713  * success and an error code in case of failure.
 714  */
 715 struct ubi_scan_leb *ubi_scan_get_free_peb(const struct ubi_device *ubi,
 716                                            struct ubi_scan_info *si)
 717 {
 718         int err = 0, i;
 719         struct ubi_scan_leb *seb;
 720
 721         if (!list_empty(&si->free)) {
 722                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 723                 list_del(&seb->u.list);
 724                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 725                 return seb;
 726         }
 727
 728         for (i = 0; i < 2; i++) {
 729                 struct list_head *head;
 730                 struct ubi_scan_leb *tmp_seb;
 731
 732                 if (i == 0)
 733                         head = &si->erase;
 734                 else
 735                         head = &si->corr;
 736
 737                 /*
 738                  * We try to erase the first physical eraseblock from the @head
 739                  * list and pick it if we succeed, or try to erase the
 740                  * next one if not. And so forth. We don't want to take care
 741                  * about bad eraseblocks here - they'll be handled later.
 742                  */
 743                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 744                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 745                                 seb->ec = si->mean_ec;
 746
 747                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 748                         if (err)
 749                                 continue;
 750
 751                         seb->ec += 1;
 752                         list_del(&seb->u.list);
 753                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 754                         return seb;
 755                 }
 756         }
 757
 758         ubi_err("no eraseblocks found");
 759         return ERR_PTR(-ENOSPC);
 760 }
 761
 762 /**
 763  * process_eb - read UBI headers, check them and add corresponding data
 764  * to the scanning information.
 765  * @ubi: UBI device description object
 766  * @si: scanning information
 767  * @pnum: the physical eraseblock number
 768  *
 769  * This function returns a zero if the physical eraseblock was successfully
 770  * handled and a negative error code in case of failure.
 771  */
 772 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
 773 {
 774         long long ec;
 775         int err, bitflips = 0, vol_id, ec_corr = 0;
 776
 777         dbg_bld("scan PEB %d", pnum);
 778
 779         /* Skip bad physical eraseblocks */
 780         err = ubi_io_is_bad(ubi, pnum);
 781         if (err < 0)
 782                 return err;
 783         else if (err) {
 784                 /*
 785                  * FIXME: this is actually duty of the I/O unit to initialize
 786                  * this, but MTD does not provide enough information.
 787                  */
 788                 si->bad_peb_count += 1;
 789                 return 0;
 790         }
 791
 792         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 793         if (err < 0)
 794                 return err;
 795         else if (err == UBI_IO_BITFLIPS)
 796                 bitflips = 1;
 797         else if (err == UBI_IO_PEB_EMPTY)
 798                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 799         else if (err == UBI_IO_BAD_EC_HDR) {
 800                 /*
 801                  * We have to also look at the VID header, possibly it is not
 802                  * corrupted. Set %bitflips flag in order to make this PEB be
 803                  * moved and EC be re-created.
 804                  */
 805                 ec_corr = 1;
 806                 ec = UBI_SCAN_UNKNOWN_EC;
 807                 bitflips = 1;
 808         }
 809
 810         si->is_empty = 0;
 811
 812         if (!ec_corr) {
 813                 /* Make sure UBI version is OK */
 814                 if (ech->version != UBI_VERSION) {
 815                         ubi_err("this UBI version is %d, image version is %d",
 816                                 UBI_VERSION, (int)ech->version);
 817                         return -EINVAL;
 818                 }
 819
 820                 ec = be64_to_cpu(ech->ec);
 821                 if (ec > UBI_MAX_ERASECOUNTER) {
 822                         /*
 823                          * Erase counter overflow. The EC headers have 64 bits
 824                          * reserved, but we anyway make use of only 31 bit
 825                          * values, as this seems to be enough for any existing
 826                          * flash. Upgrade UBI and use 64-bit erase counters
 827                          * internally.
 828                          */
 829                         ubi_err("erase counter overflow, max is %d",
 830                                 UBI_MAX_ERASECOUNTER);
 831                         ubi_dbg_dump_ec_hdr(ech);
 832                         return -EINVAL;
 833                 }
 834         }
 835
 836         /* OK, we've done with the EC header, let's look at the VID header */
 837
 838         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 839         if (err < 0)
 840                 return err;
 841         else if (err == UBI_IO_BITFLIPS)
 842                 bitflips = 1;
 843         else if (err == UBI_IO_BAD_VID_HDR ||
 844                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 845                 /* VID header is corrupted */
 846                 err = add_to_list(si, pnum, ec, &si->corr);
 847                 if (err)
 848                         return err;
 849                 goto adjust_mean_ec;
 850         } else if (err == UBI_IO_PEB_FREE) {
 851                 /* No VID header - the physical eraseblock is free */
 852                 err = add_to_list(si, pnum, ec, &si->free);
 853                 if (err)
 854                         return err;
 855                 goto adjust_mean_ec;
 856         }
 857
 858         vol_id = be32_to_cpu(vidh->vol_id);
 859         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
 860                 int lnum = be32_to_cpu(vidh->lnum);
 861
 862                 /* Unsupported internal volume */
 863                 switch (vidh->compat) {
 864                 case UBI_COMPAT_DELETE:
 865                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 866                                 " found, remove it", vol_id, lnum);
 867                         err = add_to_list(si, pnum, ec, &si->corr);
 868                         if (err)
 869                                 return err;
 870                         break;
 871
 872                 case UBI_COMPAT_RO:
 873                         ubi_msg("read-only compatible internal volume %d:%d"
 874                                 " found, switch to read-only mode",
 875                                 vol_id, lnum);
 876                         ubi->ro_mode = 1;
 877                         break;
 878
 879                 case UBI_COMPAT_PRESERVE:
 880                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 881                                 " found", vol_id, lnum);
 882                         err = add_to_list(si, pnum, ec, &si->alien);
 883                         if (err)
 884                                 return err;
 885                         si->alien_peb_count += 1;
 886                         return 0;
 887
 888                 case UBI_COMPAT_REJECT:
 889                         ubi_err("incompatible internal volume %d:%d found",
 890                                 vol_id, lnum);
 891                         return -EINVAL;
 892                 }
 893         }
 894
 895         /* Both UBI headers seem to be fine */
 896         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 897         if (err)
 898                 return err;
 899
 900 adjust_mean_ec:
 901         if (!ec_corr) {
 902                 if (si->ec_sum + ec < ec) {
 903                         commit_to_mean_value(si);
 904                         si->ec_sum = 0;
 905                         si->ec_count = 0;
 906                 } else {
 907                         si->ec_sum += ec;
 908                         si->ec_count += 1;
 909                 }
 910
 911                 if (ec > si->max_ec)
 912                         si->max_ec = ec;
 913                 if (ec < si->min_ec)
 914                         si->min_ec = ec;
 915         }
 916
 917         return 0;
 918 }
 919
 920 /**
 921  * ubi_scan - scan an MTD device.
 922  * @ubi: UBI device description object
 923  *
 924  * This function does full scanning of an MTD device and returns complete
 925  * information about it. In case of failure, an error code is returned.
 926  */
 927 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 928 {
 929         int err, pnum;
 930         struct rb_node *rb1, *rb2;
 931         struct ubi_scan_volume *sv;
 932         struct ubi_scan_leb *seb;
 933         struct ubi_scan_info *si;
 934
 935         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 936         if (!si)
 937                 return ERR_PTR(-ENOMEM);
 938
 939         INIT_LIST_HEAD(&si->corr);
 940         INIT_LIST_HEAD(&si->free);
 941         INIT_LIST_HEAD(&si->erase);
 942         INIT_LIST_HEAD(&si->alien);
 943         si->volumes = RB_ROOT;
 944         si->is_empty = 1;
 945
 946         err = -ENOMEM;
 947         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 948         if (!ech)
 949                 goto out_si;
 950
 951         vidh = ubi_zalloc_vid_hdr(ubi);
 952         if (!vidh)
 953                 goto out_ech;
 954
 955         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
 956                 cond_resched();
 957
 958                 dbg_msg("process PEB %d", pnum);
 959                 err = process_eb(ubi, si, pnum);
 960                 if (err < 0)
 961                         goto out_vidh;
 962         }
 963
 964         dbg_msg("scanning is finished");
 965
 966         /* Finish mean erase counter calculations */
 967         if (si->ec_count)
 968                 commit_to_mean_value(si);
 969
 970         if (si->is_empty)
 971                 ubi_msg("empty MTD device detected");
 972
 973         /*
 974          * In case of unknown erase counter we use the mean erase counter
 975          * value.
 976          */
 977         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 978                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
 979                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 980                                 seb->ec = si->mean_ec;
 981         }
 982
 983         list_for_each_entry(seb, &si->free, u.list) {
 984                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 985                         seb->ec = si->mean_ec;
 986         }
 987
 988         list_for_each_entry(seb, &si->corr, u.list)
 989                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 990                         seb->ec = si->mean_ec;
 991
 992         list_for_each_entry(seb, &si->erase, u.list)
 993                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 994                         seb->ec = si->mean_ec;
 995
 996         err = paranoid_check_si(ubi, si);
 997         if (err) {
 998                 if (err > 0)
 999                         err = -EINVAL;
1000                 goto out_vidh;
1001         }
1002
1003         ubi_free_vid_hdr(ubi, vidh);
1004         kfree(ech);
1005
1006         return si;
1007
1008 out_vidh:
1009         ubi_free_vid_hdr(ubi, vidh);
1010 out_ech:
1011         kfree(ech);
1012 out_si:
1013         ubi_scan_destroy_si(si);
1014         return ERR_PTR(err);
1015 }
1016
1017 /**
1018  * destroy_sv - free the scanning volume information
1019  * @sv: scanning volume information
1020  *
1021  * This function destroys the volume RB-tree (@sv->root) and the scanning
1022  * volume information.
1023  */
1024 static void destroy_sv(struct ubi_scan_volume *sv)
1025 {
1026         struct ubi_scan_leb *seb;
1027         struct rb_node *this = sv->root.rb_node;
1028
1029         while (this) {
1030                 if (this->rb_left)
1031                         this = this->rb_left;
1032                 else if (this->rb_right)
1033                         this = this->rb_right;
1034                 else {
1035                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1036                         this = rb_parent(this);
1037                         if (this) {
1038                                 if (this->rb_left == &seb->u.rb)
1039                                         this->rb_left = NULL;
1040                                 else
1041                                         this->rb_right = NULL;
1042                         }
1043
1044                         kfree(seb);
1045                 }
1046         }
1047         kfree(sv);
1048 }
1049
1050 /**
1051  * ubi_scan_destroy_si - destroy scanning information.
1052  * @si: scanning information
1053  */
1054 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1055 {
1056         struct ubi_scan_leb *seb, *seb_tmp;
1057         struct ubi_scan_volume *sv;
1058         struct rb_node *rb;
1059
1060         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1061                 list_del(&seb->u.list);
1062                 kfree(seb);
1063         }
1064         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1065                 list_del(&seb->u.list);
1066                 kfree(seb);
1067         }
1068         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1069                 list_del(&seb->u.list);
1070                 kfree(seb);
1071         }
1072         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1073                 list_del(&seb->u.list);
1074                 kfree(seb);
1075         }
1076
1077         /* Destroy the volume RB-tree */
1078         rb = si->volumes.rb_node;
1079         while (rb) {
1080                 if (rb->rb_left)
1081                         rb = rb->rb_left;
1082                 else if (rb->rb_right)
1083                         rb = rb->rb_right;
1084                 else {
1085                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1086
1087                         rb = rb_parent(rb);
1088                         if (rb) {
1089                                 if (rb->rb_left == &sv->rb)
1090                                         rb->rb_left = NULL;
1091                                 else
1092                                         rb->rb_right = NULL;
1093                         }
1094
1095                         destroy_sv(sv);
1096                 }
1097         }
1098
1099         kfree(si);
1100 }
1101
1102 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1103
1104 /**
1105  * paranoid_check_si - check if the scanning information is correct and
1106  * consistent.
1107  * @ubi: UBI device description object
1108  * @si: scanning information
1109  *
1110  * This function returns zero if the scanning information is all right, %1 if
1111  * not and a negative error code if an error occurred.
1112  */
1113 static int paranoid_check_si(const struct ubi_device *ubi,
1114                              struct ubi_scan_info *si)
1115 {
1116         int pnum, err, vols_found = 0;
1117         struct rb_node *rb1, *rb2;
1118         struct ubi_scan_volume *sv;
1119         struct ubi_scan_leb *seb, *last_seb;
1120         uint8_t *buf;
1121
1122         /*
1123          * At first, check that scanning information is OK.
1124          */
1125         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1126                 int leb_count = 0;
1127
1128                 cond_resched();
1129
1130                 vols_found += 1;
1131
1132                 if (si->is_empty) {
1133                         ubi_err("bad is_empty flag");
1134                         goto bad_sv;
1135                 }
1136
1137                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1138                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1139                     sv->data_pad < 0 || sv->last_data_size < 0) {
1140                         ubi_err("negative values");
1141                         goto bad_sv;
1142                 }
1143
1144                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1145                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1146                         ubi_err("bad vol_id");
1147                         goto bad_sv;
1148                 }
1149
1150                 if (sv->vol_id > si->highest_vol_id) {
1151                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1152                                 si->highest_vol_id, sv->vol_id);
1153                         goto out;
1154                 }
1155
1156                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1157                     sv->vol_type != UBI_STATIC_VOLUME) {
1158                         ubi_err("bad vol_type");
1159                         goto bad_sv;
1160                 }
1161
1162                 if (sv->data_pad > ubi->leb_size / 2) {
1163                         ubi_err("bad data_pad");
1164                         goto bad_sv;
1165                 }
1166
1167                 last_seb = NULL;
1168                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1169                         cond_resched();
1170
1171                         last_seb = seb;
1172                         leb_count += 1;
1173
1174                         if (seb->pnum < 0 || seb->ec < 0) {
1175                                 ubi_err("negative values");
1176                                 goto bad_seb;
1177                         }
1178
1179                         if (seb->ec < si->min_ec) {
1180                                 ubi_err("bad si->min_ec (%d), %d found",
1181                                         si->min_ec, seb->ec);
1182                                 goto bad_seb;
1183                         }
1184
1185                         if (seb->ec > si->max_ec) {
1186                                 ubi_err("bad si->max_ec (%d), %d found",
1187                                         si->max_ec, seb->ec);
1188                                 goto bad_seb;
1189                         }
1190
1191                         if (seb->pnum >= ubi->peb_count) {
1192                                 ubi_err("too high PEB number %d, total PEBs %d",
1193                                         seb->pnum, ubi->peb_count);
1194                                 goto bad_seb;
1195                         }
1196
1197                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1198                                 if (seb->lnum >= sv->used_ebs) {
1199                                         ubi_err("bad lnum or used_ebs");
1200                                         goto bad_seb;
1201                                 }
1202                         } else {
1203                                 if (sv->used_ebs != 0) {
1204                                         ubi_err("non-zero used_ebs");
1205                                         goto bad_seb;
1206                                 }
1207                         }
1208
1209                         if (seb->lnum > sv->highest_lnum) {
1210                                 ubi_err("incorrect highest_lnum or lnum");
1211                                 goto bad_seb;
1212                         }
1213                 }
1214
1215                 if (sv->leb_count != leb_count) {
1216                         ubi_err("bad leb_count, %d objects in the tree",
1217                                 leb_count);
1218                         goto bad_sv;
1219                 }
1220
1221                 if (!last_seb)
1222                         continue;
1223
1224                 seb = last_seb;
1225
1226                 if (seb->lnum != sv->highest_lnum) {
1227                         ubi_err("bad highest_lnum");
1228                         goto bad_seb;
1229                 }
1230         }
1231
1232         if (vols_found != si->vols_found) {
1233                 ubi_err("bad si->vols_found %d, should be %d",
1234                         si->vols_found, vols_found);
1235                 goto out;
1236         }
1237
1238         /* Check that scanning information is correct */
1239         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1240                 last_seb = NULL;
1241                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1242                         int vol_type;
1243
1244                         cond_resched();
1245
1246                         last_seb = seb;
1247
1248                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1249                         if (err && err != UBI_IO_BITFLIPS) {
1250                                 ubi_err("VID header is not OK (%d)", err);
1251                                 if (err > 0)
1252                                         err = -EIO;
1253                                 return err;
1254                         }
1255
1256                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1257                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1258                         if (sv->vol_type != vol_type) {
1259                                 ubi_err("bad vol_type");
1260                                 goto bad_vid_hdr;
1261                         }
1262
1263                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1264                                 ubi_err("bad sqnum %llu", seb->sqnum);
1265                                 goto bad_vid_hdr;
1266                         }
1267
1268                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1269                                 ubi_err("bad vol_id %d", sv->vol_id);
1270                                 goto bad_vid_hdr;
1271                         }
1272
1273                         if (sv->compat != vidh->compat) {
1274                                 ubi_err("bad compat %d", vidh->compat);
1275                                 goto bad_vid_hdr;
1276                         }
1277
1278                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1279                                 ubi_err("bad lnum %d", seb->lnum);
1280                                 goto bad_vid_hdr;
1281                         }
1282
1283                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1284                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1285                                 goto bad_vid_hdr;
1286                         }
1287
1288                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1289                                 ubi_err("bad data_pad %d", sv->data_pad);
1290                                 goto bad_vid_hdr;
1291                         }
1292
1293                         if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
1294                                 ubi_err("bad leb_ver %u", seb->leb_ver);
1295                                 goto bad_vid_hdr;
1296                         }
1297                 }
1298
1299                 if (!last_seb)
1300                         continue;
1301
1302                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1303                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1304                         goto bad_vid_hdr;
1305                 }
1306
1307                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1308                         ubi_err("bad last_data_size %d", sv->last_data_size);
1309                         goto bad_vid_hdr;
1310                 }
1311         }
1312
1313         /*
1314          * Make sure that all the physical eraseblocks are in one of the lists
1315          * or trees.
1316          */
1317         buf = kmalloc(ubi->peb_count, GFP_KERNEL);
1318         if (!buf)
1319                 return -ENOMEM;
1320
1321         memset(buf, 1, ubi->peb_count);
1322         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1323                 err = ubi_io_is_bad(ubi, pnum);
1324                 if (err < 0) {
1325                         kfree(buf);
1326                         return err;
1327                 }
1328                 else if (err)
1329                         buf[pnum] = 0;
1330         }
1331
1332         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1333                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1334                         buf[seb->pnum] = 0;
1335
1336         list_for_each_entry(seb, &si->free, u.list)
1337                 buf[seb->pnum] = 0;
1338
1339         list_for_each_entry(seb, &si->corr, u.list)
1340                 buf[seb->pnum] = 0;
1341
1342         list_for_each_entry(seb, &si->erase, u.list)
1343                 buf[seb->pnum] = 0;
1344
1345         list_for_each_entry(seb, &si->alien, u.list)
1346                 buf[seb->pnum] = 0;
1347
1348         err = 0;
1349         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1350                 if (buf[pnum]) {
1351                         ubi_err("PEB %d is not referred", pnum);
1352                         err = 1;
1353                 }
1354
1355         kfree(buf);
1356         if (err)
1357                 goto out;
1358         return 0;
1359
1360 bad_seb:
1361         ubi_err("bad scanning information about LEB %d", seb->lnum);
1362         ubi_dbg_dump_seb(seb, 0);
1363         ubi_dbg_dump_sv(sv);
1364         goto out;
1365
1366 bad_sv:
1367         ubi_err("bad scanning information about volume %d", sv->vol_id);
1368         ubi_dbg_dump_sv(sv);
1369         goto out;
1370
1371 bad_vid_hdr:
1372         ubi_err("bad scanning information about volume %d", sv->vol_id);
1373         ubi_dbg_dump_sv(sv);
1374         ubi_dbg_dump_vid_hdr(vidh);
1375
1376 out:
1377         ubi_dbg_dump_stack();
1378         return 1;
1379 }
1380
1381 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */