drivers/mtd/ubi/scan.c

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Author: Artem Bityutskiy (Битюцкий Артём)
  19  */
  20
  21 /*
  22  * UBI scanning sub-system.
  23  *
  24  * This sub-system is responsible for scanning the flash media, checking UBI
  25  * headers and providing complete information about the UBI flash image.
  26  *
  27  * The scanning information is represented by a &struct ubi_scan_info' object.
  28  * Information about found volumes is represented by &struct ubi_scan_volume
  29  * objects which are kept in volume RB-tree with root at the @volumes field.
  30  * The RB-tree is indexed by the volume ID.
  31  *
  32  * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
  33  * These objects are kept in per-volume RB-trees with the root at the
  34  * corresponding &struct ubi_scan_volume object. To put it differently, we keep
  35  * an RB-tree of per-volume objects and each of these objects is the root of
  36  * RB-tree of per-eraseblock objects.
  37  *
  38  * Corrupted physical eraseblocks are put to the @corr list, free physical
  39  * eraseblocks are put to the @free list and the physical eraseblock to be
  40  * erased are put to the @erase list.
  41  */
  42
  43 #include <linux/err.h>
  44 #include <linux/slab.h>
  45 #include <linux/crc32.h>
  46 #include <linux/math64.h>
  47 #include <linux/random.h>
  48 #include "ubi.h"
  49
  50 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  51 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
  52 #else
  53 #define paranoid_check_si(ubi, si) 0
  54 #endif
  55
  56 /* Temporary variables used during scanning */
  57 static struct ubi_ec_hdr *ech;
  58 static struct ubi_vid_hdr *vidh;
  59
  60 /**
  61  * add_to_list - add physical eraseblock to a list.
  62  * @si: scanning information
  63  * @pnum: physical eraseblock number to add
  64  * @ec: erase counter of the physical eraseblock
  65  * @list: the list to add to
  66  *
  67  * This function adds physical eraseblock @pnum to free, erase, corrupted or
  68  * alien lists. Returns zero in case of success and a negative error code in
  69  * case of failure.
  70  */
  71 static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
  72                        struct list_head *list)
  73 {
  74         struct ubi_scan_leb *seb;
  75
  76         if (list == &si->free) {
  77                 dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
  78                 si->free_peb_count += 1;
  79         } else if (list == &si->erase) {
  80                 dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
  81                 si->erase_peb_count += 1;
  82         } else if (list == &si->corr) {
  83                 dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
  84                 si->corr_peb_count += 1;
  85         } else if (list == &si->alien) {
  86                 dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
  87                 si->alien_peb_count += 1;
  88         } else
  89                 BUG();
  90
  91         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
  92         if (!seb)
  93                 return -ENOMEM;
  94
  95         seb->pnum = pnum;
  96         seb->ec = ec;
  97         list_add_tail(&seb->u.list, list);
  98         return 0;
  99 }
 100
 101 /**
 102  * validate_vid_hdr - check volume identifier header.
 103  * @vid_hdr: the volume identifier header to check
 104  * @sv: information about the volume this logical eraseblock belongs to
 105  * @pnum: physical eraseblock number the VID header came from
 106  *
 107  * This function checks that data stored in @vid_hdr is consistent. Returns
 108  * non-zero if an inconsistency was found and zero if not.
 109  *
 110  * Note, UBI does sanity check of everything it reads from the flash media.
 111  * Most of the checks are done in the I/O sub-system. Here we check that the
 112  * information in the VID header is consistent to the information in other VID
 113  * headers of the same volume.
 114  */
 115 static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
 116                             const struct ubi_scan_volume *sv, int pnum)
 117 {
 118         int vol_type = vid_hdr->vol_type;
 119         int vol_id = be32_to_cpu(vid_hdr->vol_id);
 120         int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 121         int data_pad = be32_to_cpu(vid_hdr->data_pad);
 122
 123         if (sv->leb_count != 0) {
 124                 int sv_vol_type;
 125
 126                 /*
 127                  * This is not the first logical eraseblock belonging to this
 128                  * volume. Ensure that the data in its VID header is consistent
 129                  * to the data in previous logical eraseblock headers.
 130                  */
 131
 132                 if (vol_id != sv->vol_id) {
 133                         dbg_err("inconsistent vol_id");
 134                         goto bad;
 135                 }
 136
 137                 if (sv->vol_type == UBI_STATIC_VOLUME)
 138                         sv_vol_type = UBI_VID_STATIC;
 139                 else
 140                         sv_vol_type = UBI_VID_DYNAMIC;
 141
 142                 if (vol_type != sv_vol_type) {
 143                         dbg_err("inconsistent vol_type");
 144                         goto bad;
 145                 }
 146
 147                 if (used_ebs != sv->used_ebs) {
 148                         dbg_err("inconsistent used_ebs");
 149                         goto bad;
 150                 }
 151
 152                 if (data_pad != sv->data_pad) {
 153                         dbg_err("inconsistent data_pad");
 154                         goto bad;
 155                 }
 156         }
 157
 158         return 0;
 159
 160 bad:
 161         ubi_err("inconsistent VID header at PEB %d", pnum);
 162         ubi_dbg_dump_vid_hdr(vid_hdr);
 163         ubi_dbg_dump_sv(sv);
 164         return -EINVAL;
 165 }
 166
 167 /**
 168  * add_volume - add volume to the scanning information.
 169  * @si: scanning information
 170  * @vol_id: ID of the volume to add
 171  * @pnum: physical eraseblock number
 172  * @vid_hdr: volume identifier header
 173  *
 174  * If the volume corresponding to the @vid_hdr logical eraseblock is already
 175  * present in the scanning information, this function does nothing. Otherwise
 176  * it adds corresponding volume to the scanning information. Returns a pointer
 177  * to the scanning volume object in case of success and a negative error code
 178  * in case of failure.
 179  */
 180 static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
 181                                           int pnum,
 182                                           const struct ubi_vid_hdr *vid_hdr)
 183 {
 184         struct ubi_scan_volume *sv;
 185         struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
 186
 187         ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
 188
 189         /* Walk the volume RB-tree to look if this volume is already present */
 190         while (*p) {
 191                 parent = *p;
 192                 sv = rb_entry(parent, struct ubi_scan_volume, rb);
 193
 194                 if (vol_id == sv->vol_id)
 195                         return sv;
 196
 197                 if (vol_id > sv->vol_id)
 198                         p = &(*p)->rb_left;
 199                 else
 200                         p = &(*p)->rb_right;
 201         }
 202
 203         /* The volume is absent - add it */
 204         sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
 205         if (!sv)
 206                 return ERR_PTR(-ENOMEM);
 207
 208         sv->highest_lnum = sv->leb_count = 0;
 209         sv->vol_id = vol_id;
 210         sv->root = RB_ROOT;
 211         sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
 212         sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
 213         sv->compat = vid_hdr->compat;
 214         sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
 215                                                             : UBI_STATIC_VOLUME;
 216         if (vol_id > si->highest_vol_id)
 217                 si->highest_vol_id = vol_id;
 218
 219         rb_link_node(&sv->rb, parent, p);
 220         rb_insert_color(&sv->rb, &si->volumes);
 221         si->vols_found += 1;
 222         dbg_bld("added volume %d", vol_id);
 223         return sv;
 224 }
 225
 226 /**
 227  * compare_lebs - find out which logical eraseblock is newer.
 228  * @ubi: UBI device description object
 229  * @seb: first logical eraseblock to compare
 230  * @pnum: physical eraseblock number of the second logical eraseblock to
 231  * compare
 232  * @vid_hdr: volume identifier header of the second logical eraseblock
 233  *
 234  * This function compares 2 copies of a LEB and informs which one is newer. In
 235  * case of success this function returns a positive value, in case of failure, a
 236  * negative error code is returned. The success return codes use the following
 237  * bits:
 238  *     o bit 0 is cleared: the first PEB (described by @seb) is newer than the
 239  *       second PEB (described by @pnum and @vid_hdr);
 240  *     o bit 0 is set: the second PEB is newer;
 241  *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
 242  *     o bit 1 is set: bit-flips were detected in the newer LEB;
 243  *     o bit 2 is cleared: the older LEB is not corrupted;
 244  *     o bit 2 is set: the older LEB is corrupted.
 245  */
 246 static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 247                         int pnum, const struct ubi_vid_hdr *vid_hdr)
 248 {
 249         void *buf;
 250         int len, err, second_is_newer, bitflips = 0, corrupted = 0;
 251         uint32_t data_crc, crc;
 252         struct ubi_vid_hdr *vh = NULL;
 253         unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
 254
 255         if (sqnum2 == seb->sqnum) {
 256                 /*
 257                  * This must be a really ancient UBI image which has been
 258                  * created before sequence numbers support has been added. At
 259                  * that times we used 32-bit LEB versions stored in logical
 260                  * eraseblocks. That was before UBI got into mainline. We do not
 261                  * support these images anymore. Well, those images will work
 262                  * still work, but only if no unclean reboots happened.
 263                  */
 264                 ubi_err("unsupported on-flash UBI format\n");
 265                 return -EINVAL;
 266         }
 267
 268         /* Obviously the LEB with lower sequence counter is older */
 269         second_is_newer = !!(sqnum2 > seb->sqnum);
 270
 271         /*
 272          * Now we know which copy is newer. If the copy flag of the PEB with
 273          * newer version is not set, then we just return, otherwise we have to
 274          * check data CRC. For the second PEB we already have the VID header,
 275          * for the first one - we'll need to re-read it from flash.
 276          *
 277          * Note: this may be optimized so that we wouldn't read twice.
 278          */
 279
 280         if (second_is_newer) {
 281                 if (!vid_hdr->copy_flag) {
 282                         /* It is not a copy, so it is newer */
 283                         dbg_bld("second PEB %d is newer, copy_flag is unset",
 284                                 pnum);
 285                         return 1;
 286                 }
 287         } else {
 288                 pnum = seb->pnum;
 289
 290                 vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 291                 if (!vh)
 292                         return -ENOMEM;
 293
 294                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 295                 if (err) {
 296                         if (err == UBI_IO_BITFLIPS)
 297                                 bitflips = 1;
 298                         else {
 299                                 dbg_err("VID of PEB %d header is bad, but it "
 300                                         "was OK earlier", pnum);
 301                                 if (err > 0)
 302                                         err = -EIO;
 303
 304                                 goto out_free_vidh;
 305                         }
 306                 }
 307
 308                 if (!vh->copy_flag) {
 309                         /* It is not a copy, so it is newer */
 310                         dbg_bld("first PEB %d is newer, copy_flag is unset",
 311                                 pnum);
 312                         err = bitflips << 1;
 313                         goto out_free_vidh;
 314                 }
 315
 316                 vid_hdr = vh;
 317         }
 318
 319         /* Read the data of the copy and check the CRC */
 320
 321         len = be32_to_cpu(vid_hdr->data_size);
 322         buf = vmalloc(len);
 323         if (!buf) {
 324                 err = -ENOMEM;
 325                 goto out_free_vidh;
 326         }
 327
 328         err = ubi_io_read_data(ubi, buf, pnum, 0, len);
 329         if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
 330                 goto out_free_buf;
 331
 332         data_crc = be32_to_cpu(vid_hdr->data_crc);
 333         crc = crc32(UBI_CRC32_INIT, buf, len);
 334         if (crc != data_crc) {
 335                 dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
 336                         pnum, crc, data_crc);
 337                 corrupted = 1;
 338                 bitflips = 0;
 339                 second_is_newer = !second_is_newer;
 340         } else {
 341                 dbg_bld("PEB %d CRC is OK", pnum);
 342                 bitflips = !!err;
 343         }
 344
 345         vfree(buf);
 346         ubi_free_vid_hdr(ubi, vh);
 347
 348         if (second_is_newer)
 349                 dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
 350         else
 351                 dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
 352
 353         return second_is_newer | (bitflips << 1) | (corrupted << 2);
 354
 355 out_free_buf:
 356         vfree(buf);
 357 out_free_vidh:
 358         ubi_free_vid_hdr(ubi, vh);
 359         return err;
 360 }
 361
 362 /**
 363  * ubi_scan_add_used - add physical eraseblock to the scanning information.
 364  * @ubi: UBI device description object
 365  * @si: scanning information
 366  * @pnum: the physical eraseblock number
 367  * @ec: erase counter
 368  * @vid_hdr: the volume identifier header
 369  * @bitflips: if bit-flips were detected when this physical eraseblock was read
 370  *
 371  * This function adds information about a used physical eraseblock to the
 372  * 'used' tree of the corresponding volume. The function is rather complex
 373  * because it has to handle cases when this is not the first physical
 374  * eraseblock belonging to the same logical eraseblock, and the newer one has
 375  * to be picked, while the older one has to be dropped. This function returns
 376  * zero in case of success and a negative error code in case of failure.
 377  */
 378 int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 379                       int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
 380                       int bitflips)
 381 {
 382         int err, vol_id, lnum;
 383         unsigned long long sqnum;
 384         struct ubi_scan_volume *sv;
 385         struct ubi_scan_leb *seb;
 386         struct rb_node **p, *parent = NULL;
 387
 388         vol_id = be32_to_cpu(vid_hdr->vol_id);
 389         lnum = be32_to_cpu(vid_hdr->lnum);
 390         sqnum = be64_to_cpu(vid_hdr->sqnum);
 391
 392         dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
 393                 pnum, vol_id, lnum, ec, sqnum, bitflips);
 394
 395         sv = add_volume(si, vol_id, pnum, vid_hdr);
 396         if (IS_ERR(sv))
 397                 return PTR_ERR(sv);
 398
 399         if (si->max_sqnum < sqnum)
 400                 si->max_sqnum = sqnum;
 401
 402         /*
 403          * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
 404          * if this is the first instance of this logical eraseblock or not.
 405          */
 406         p = &sv->root.rb_node;
 407         while (*p) {
 408                 int cmp_res;
 409
 410                 parent = *p;
 411                 seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
 412                 if (lnum != seb->lnum) {
 413                         if (lnum < seb->lnum)
 414                                 p = &(*p)->rb_left;
 415                         else
 416                                 p = &(*p)->rb_right;
 417                         continue;
 418                 }
 419
 420                 /*
 421                  * There is already a physical eraseblock describing the same
 422                  * logical eraseblock present.
 423                  */
 424
 425                 dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
 426                         "EC %d", seb->pnum, seb->sqnum, seb->ec);
 427
 428                 /*
 429                  * Make sure that the logical eraseblocks have different
 430                  * sequence numbers. Otherwise the image is bad.
 431                  *
 432                  * However, if the sequence number is zero, we assume it must
 433                  * be an ancient UBI image from the era when UBI did not have
 434                  * sequence numbers. We still can attach these images, unless
 435                  * there is a need to distinguish between old and new
 436                  * eraseblocks, in which case we'll refuse the image in
 437                  * 'compare_lebs()'. In other words, we attach old clean
 438                  * images, but refuse attaching old images with duplicated
 439                  * logical eraseblocks because there was an unclean reboot.
 440                  */
 441                 if (seb->sqnum == sqnum && sqnum != 0) {
 442                         ubi_err("two LEBs with same sequence number %llu",
 443                                 sqnum);
 444                         ubi_dbg_dump_seb(seb, 0);
 445                         ubi_dbg_dump_vid_hdr(vid_hdr);
 446                         return -EINVAL;
 447                 }
 448
 449                 /*
 450                  * Now we have to drop the older one and preserve the newer
 451                  * one.
 452                  */
 453                 cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
 454                 if (cmp_res < 0)
 455                         return cmp_res;
 456
 457                 if (cmp_res & 1) {
 458                         /*
 459                          * This logical eraseblock is newer than the one
 460                          * found earlier.
 461                          */
 462                         err = validate_vid_hdr(vid_hdr, sv, pnum);
 463                         if (err)
 464                                 return err;
 465
 466                         if (cmp_res & 4)
 467                                 err = add_to_list(si, seb->pnum, seb->ec,
 468                                                   &si->corr);
 469                         else
 470                                 err = add_to_list(si, seb->pnum, seb->ec,
 471                                                   &si->erase);
 472                         if (err)
 473                                 return err;
 474
 475                         seb->ec = ec;
 476                         seb->pnum = pnum;
 477                         seb->scrub = ((cmp_res & 2) || bitflips);
 478                         seb->sqnum = sqnum;
 479
 480                         if (sv->highest_lnum == lnum)
 481                                 sv->last_data_size =
 482                                         be32_to_cpu(vid_hdr->data_size);
 483
 484                         return 0;
 485                 } else {
 486                         /*
 487                          * This logical eraseblock is older than the one found
 488                          * previously.
 489                          */
 490                         if (cmp_res & 4)
 491                                 return add_to_list(si, pnum, ec, &si->corr);
 492                         else
 493                                 return add_to_list(si, pnum, ec, &si->erase);
 494                 }
 495         }
 496
 497         /*
 498          * We've met this logical eraseblock for the first time, add it to the
 499          * scanning information.
 500          */
 501
 502         err = validate_vid_hdr(vid_hdr, sv, pnum);
 503         if (err)
 504                 return err;
 505
 506         seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
 507         if (!seb)
 508                 return -ENOMEM;
 509
 510         seb->ec = ec;
 511         seb->pnum = pnum;
 512         seb->lnum = lnum;
 513         seb->sqnum = sqnum;
 514         seb->scrub = bitflips;
 515
 516         if (sv->highest_lnum <= lnum) {
 517                 sv->highest_lnum = lnum;
 518                 sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
 519         }
 520
 521         sv->leb_count += 1;
 522         rb_link_node(&seb->u.rb, parent, p);
 523         rb_insert_color(&seb->u.rb, &sv->root);
 524         si->used_peb_count += 1;
 525         return 0;
 526 }
 527
 528 /**
 529  * ubi_scan_find_sv - find volume in the scanning information.
 530  * @si: scanning information
 531  * @vol_id: the requested volume ID
 532  *
 533  * This function returns a pointer to the volume description or %NULL if there
 534  * are no data about this volume in the scanning information.
 535  */
 536 struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
 537                                          int vol_id)
 538 {
 539         struct ubi_scan_volume *sv;
 540         struct rb_node *p = si->volumes.rb_node;
 541
 542         while (p) {
 543                 sv = rb_entry(p, struct ubi_scan_volume, rb);
 544
 545                 if (vol_id == sv->vol_id)
 546                         return sv;
 547
 548                 if (vol_id > sv->vol_id)
 549                         p = p->rb_left;
 550                 else
 551                         p = p->rb_right;
 552         }
 553
 554         return NULL;
 555 }
 556
 557 /**
 558  * ubi_scan_find_seb - find LEB in the volume scanning information.
 559  * @sv: a pointer to the volume scanning information
 560  * @lnum: the requested logical eraseblock
 561  *
 562  * This function returns a pointer to the scanning logical eraseblock or %NULL
 563  * if there are no data about it in the scanning volume information.
 564  */
 565 struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
 566                                        int lnum)
 567 {
 568         struct ubi_scan_leb *seb;
 569         struct rb_node *p = sv->root.rb_node;
 570
 571         while (p) {
 572                 seb = rb_entry(p, struct ubi_scan_leb, u.rb);
 573
 574                 if (lnum == seb->lnum)
 575                         return seb;
 576
 577                 if (lnum > seb->lnum)
 578                         p = p->rb_left;
 579                 else
 580                         p = p->rb_right;
 581         }
 582
 583         return NULL;
 584 }
 585
 586 /**
 587  * ubi_scan_rm_volume - delete scanning information about a volume.
 588  * @si: scanning information
 589  * @sv: the volume scanning information to delete
 590  */
 591 void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
 592 {
 593         struct rb_node *rb;
 594         struct ubi_scan_leb *seb;
 595
 596         dbg_bld("remove scanning information about volume %d", sv->vol_id);
 597
 598         while ((rb = rb_first(&sv->root))) {
 599                 seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
 600                 rb_erase(&seb->u.rb, &sv->root);
 601                 list_add_tail(&seb->u.list, &si->erase);
 602         }
 603
 604         rb_erase(&sv->rb, &si->volumes);
 605         kfree(sv);
 606         si->vols_found -= 1;
 607 }
 608
 609 /**
 610  * ubi_scan_erase_peb - erase a physical eraseblock.
 611  * @ubi: UBI device description object
 612  * @si: scanning information
 613  * @pnum: physical eraseblock number to erase;
 614  * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
 615  *
 616  * This function erases physical eraseblock 'pnum', and writes the erase
 617  * counter header to it. This function should only be used on UBI device
 618  * initialization stages, when the EBA sub-system had not been yet initialized.
 619  * This function returns zero in case of success and a negative error code in
 620  * case of failure.
 621  */
 622 int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
 623                        int pnum, int ec)
 624 {
 625         int err;
 626         struct ubi_ec_hdr *ec_hdr;
 627
 628         if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
 629                 /*
 630                  * Erase counter overflow. Upgrade UBI and use 64-bit
 631                  * erase counters internally.
 632                  */
 633                 ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
 634                 return -EINVAL;
 635         }
 636
 637         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 638         if (!ec_hdr)
 639                 return -ENOMEM;
 640
 641         ec_hdr->ec = cpu_to_be64(ec);
 642
 643         err = ubi_io_sync_erase(ubi, pnum, 0);
 644         if (err < 0)
 645                 goto out_free;
 646
 647         err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
 648
 649 out_free:
 650         kfree(ec_hdr);
 651         return err;
 652 }
 653
 654 /**
 655  * ubi_scan_get_free_peb - get a free physical eraseblock.
 656  * @ubi: UBI device description object
 657  * @si: scanning information
 658  *
 659  * This function returns a free physical eraseblock. It is supposed to be
 660  * called on the UBI initialization stages when the wear-leveling sub-system is
 661  * not initialized yet. This function picks a physical eraseblocks from one of
 662  * the lists, writes the EC header if it is needed, and removes it from the
 663  * list.
 664  *
 665  * This function returns scanning physical eraseblock information in case of
 666  * success and an error code in case of failure.
 667  */
 668 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 669                                            struct ubi_scan_info *si)
 670 {
 671         int err = 0, i;
 672         struct ubi_scan_leb *seb;
 673
 674         if (!list_empty(&si->free)) {
 675                 seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
 676                 list_del(&seb->u.list);
 677                 dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
 678                 return seb;
 679         }
 680
 681         for (i = 0; i < 2; i++) {
 682                 struct list_head *head;
 683                 struct ubi_scan_leb *tmp_seb;
 684
 685                 if (i == 0)
 686                         head = &si->erase;
 687                 else
 688                         head = &si->corr;
 689
 690                 /*
 691                  * We try to erase the first physical eraseblock from the @head
 692                  * list and pick it if we succeed, or try to erase the
 693                  * next one if not. And so forth. We don't want to take care
 694                  * about bad eraseblocks here - they'll be handled later.
 695                  */
 696                 list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
 697                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
 698                                 seb->ec = si->mean_ec;
 699
 700                         err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
 701                         if (err)
 702                                 continue;
 703
 704                         seb->ec += 1;
 705                         list_del(&seb->u.list);
 706                         dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
 707                         return seb;
 708                 }
 709         }
 710
 711         ubi_err("no eraseblocks found");
 712         return ERR_PTR(-ENOSPC);
 713 }
 714
 715 /**
 716  * process_eb - read, check UBI headers, and add them to scanning information.
 717  * @ubi: UBI device description object
 718  * @si: scanning information
 719  * @pnum: the physical eraseblock number
 720  *
 721  * This function returns a zero if the physical eraseblock was successfully
 722  * handled and a negative error code in case of failure.
 723  */
 724 static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 725                       int pnum)
 726 {
 727         long long uninitialized_var(ec);
 728         int err, bitflips = 0, vol_id, ec_corr = 0;
 729
 730         dbg_bld("scan PEB %d", pnum);
 731
 732         /* Skip bad physical eraseblocks */
 733         err = ubi_io_is_bad(ubi, pnum);
 734         if (err < 0)
 735                 return err;
 736         else if (err) {
 737                 /*
 738                  * FIXME: this is actually duty of the I/O sub-system to
 739                  * initialize this, but MTD does not provide enough
 740                  * information.
 741                  */
 742                 si->bad_peb_count += 1;
 743                 return 0;
 744         }
 745
 746         err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 747         if (err < 0)
 748                 return err;
 749         else if (err == UBI_IO_BITFLIPS)
 750                 bitflips = 1;
 751         else if (err == UBI_IO_PEB_EMPTY)
 752                 return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
 753         else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) {
 754                 /*
 755                  * We have to also look at the VID header, possibly it is not
 756                  * corrupted. Set %bitflips flag in order to make this PEB be
 757                  * moved and EC be re-created.
 758                  */
 759                 ec_corr = err;
 760                 ec = UBI_SCAN_UNKNOWN_EC;
 761                 bitflips = 1;
 762         }
 763
 764         if (!ec_corr) {
 765                 int image_seq;
 766
 767                 /* Make sure UBI version is OK */
 768                 if (ech->version != UBI_VERSION) {
 769                         ubi_err("this UBI version is %d, image version is %d",
 770                                 UBI_VERSION, (int)ech->version);
 771                         return -EINVAL;
 772                 }
 773
 774                 ec = be64_to_cpu(ech->ec);
 775                 if (ec > UBI_MAX_ERASECOUNTER) {
 776                         /*
 777                          * Erase counter overflow. The EC headers have 64 bits
 778                          * reserved, but we anyway make use of only 31 bit
 779                          * values, as this seems to be enough for any existing
 780                          * flash. Upgrade UBI and use 64-bit erase counters
 781                          * internally.
 782                          */
 783                         ubi_err("erase counter overflow, max is %d",
 784                                 UBI_MAX_ERASECOUNTER);
 785                         ubi_dbg_dump_ec_hdr(ech);
 786                         return -EINVAL;
 787                 }
 788
 789                 /*
 790                  * Make sure that all PEBs have the same image sequence number.
 791                  * This allows us to detect situations when users flash UBI
 792                  * images incorrectly, so that the flash has the new UBI image
 793                  * and leftovers from the old one. This feature was added
 794                  * relatively recently, and the sequence number was always
 795                  * zero, because old UBI implementations always set it to zero.
 796                  * For this reasons, we do not panic if some PEBs have zero
 797                  * sequence number, while other PEBs have non-zero sequence
 798                  * number.
 799                  */
 800                 image_seq = be32_to_cpu(ech->image_seq);
 801                 if (!ubi->image_seq && image_seq)
 802                         ubi->image_seq = image_seq;
 803                 if (ubi->image_seq && image_seq &&
 804                     ubi->image_seq != image_seq) {
 805                         ubi_err("bad image sequence number %d in PEB %d, "
 806                                 "expected %d", image_seq, pnum, ubi->image_seq);
 807                         ubi_dbg_dump_ec_hdr(ech);
 808                         return -EINVAL;
 809                 }
 810         }
 811
 812         /* OK, we've done with the EC header, let's look at the VID header */
 813
 814         err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 815         if (err < 0)
 816                 return err;
 817         else if (err == UBI_IO_BITFLIPS)
 818                 bitflips = 1;
 819         else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR ||
 820                  (err == UBI_IO_PEB_FREE && ec_corr)) {
 821                 /* VID header is corrupted */
 822                 if (err == UBI_IO_BAD_HDR_READ ||
 823                     ec_corr == UBI_IO_BAD_HDR_READ)
 824                         si->read_err_count += 1;
 825                 err = add_to_list(si, pnum, ec, &si->corr);
 826                 if (err)
 827                         return err;
 828                 goto adjust_mean_ec;
 829         } else if (err == UBI_IO_PEB_FREE) {
 830                 /* No VID header - the physical eraseblock is free */
 831                 err = add_to_list(si, pnum, ec, &si->free);
 832                 if (err)
 833                         return err;
 834                 goto adjust_mean_ec;
 835         }
 836
 837         vol_id = be32_to_cpu(vidh->vol_id);
 838         if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
 839                 int lnum = be32_to_cpu(vidh->lnum);
 840
 841                 /* Unsupported internal volume */
 842                 switch (vidh->compat) {
 843                 case UBI_COMPAT_DELETE:
 844                         ubi_msg("\"delete\" compatible internal volume %d:%d"
 845                                 " found, will remove it", vol_id, lnum);
 846                         err = add_to_list(si, pnum, ec, &si->erase);
 847                         if (err)
 848                                 return err;
 849                         return 0;
 850
 851                 case UBI_COMPAT_RO:
 852                         ubi_msg("read-only compatible internal volume %d:%d"
 853                                 " found, switch to read-only mode",
 854                                 vol_id, lnum);
 855                         ubi->ro_mode = 1;
 856                         break;
 857
 858                 case UBI_COMPAT_PRESERVE:
 859                         ubi_msg("\"preserve\" compatible internal volume %d:%d"
 860                                 " found", vol_id, lnum);
 861                         err = add_to_list(si, pnum, ec, &si->alien);
 862                         if (err)
 863                                 return err;
 864                         return 0;
 865
 866                 case UBI_COMPAT_REJECT:
 867                         ubi_err("incompatible internal volume %d:%d found",
 868                                 vol_id, lnum);
 869                         return -EINVAL;
 870                 }
 871         }
 872
 873         if (ec_corr)
 874                 ubi_warn("valid VID header but corrupted EC header at PEB %d",
 875                          pnum);
 876         err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
 877         if (err)
 878                 return err;
 879
 880 adjust_mean_ec:
 881         if (!ec_corr) {
 882                 si->ec_sum += ec;
 883                 si->ec_count += 1;
 884                 if (ec > si->max_ec)
 885                         si->max_ec = ec;
 886                 if (ec < si->min_ec)
 887                         si->min_ec = ec;
 888         }
 889
 890         return 0;
 891 }
 892
 893 /**
 894  * check_what_we_have - check what PEB were found by scanning.
 895  * @ubi: UBI device description object
 896  * @si: scanning information
 897  *
 898  * This is a helper function which takes a look what PEBs were found by
 899  * scanning, and decides whether the flash is empty and should be formatted and
 900  * whether there are too many corrupted PEBs and we should not attach this
 901  * MTD device. Returns zero if we should proceed with attaching the MTD device,
 902  * and %-EINVAL if we should not.
 903  */
 904 static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si)
 905 {
 906         struct ubi_scan_leb *seb;
 907         int max_corr;
 908
 909         max_corr = ubi->peb_count - si->bad_peb_count - si->alien_peb_count;
 910         max_corr = max_corr / 20 ?: 8;
 911
 912         /*
 913          * Few corrupted PEBs are not a problem and may be just a result of
 914          * unclean reboots. However, many of them may indicate some problems
 915          * with the flash HW or driver.
 916          */
 917         if (si->corr_peb_count >= 8) {
 918                 ubi_warn("%d PEBs are corrupted", si->corr_peb_count);
 919                 printk(KERN_WARNING "corrupted PEBs are:");
 920                 list_for_each_entry(seb, &si->corr, u.list)
 921                         printk(KERN_CONT " %d", seb->pnum);
 922                 printk(KERN_CONT "\n");
 923
 924                 /*
 925                  * If too many PEBs are corrupted, we refuse attaching,
 926                  * otherwise, only print a warning.
 927                  */
 928                 if (si->corr_peb_count >= max_corr) {
 929                         ubi_err("too many corrupted PEBs, refusing this device");
 930                         return -EINVAL;
 931                 }
 932         }
 933
 934         if (si->free_peb_count + si->used_peb_count +
 935             si->alien_peb_count == 0) {
 936                 /* No UBI-formatted eraseblocks were found */
 937                 if (si->corr_peb_count == si->read_err_count &&
 938                     si->corr_peb_count < 8) {
 939                         /* No or just few corrupted PEBs, and all of them had a
 940                          * read error. We assume that those are bad PEBs, which
 941                          * were just not marked as bad so far.
 942                          *
 943                          * This piece of code basically tries to distinguish
 944                          * between the following 2 situations:
 945                          *
 946                          * 1. Flash is empty, but there are few bad PEBs, which
 947                          *    are not marked as bad so far, and which were read
 948                          *    with error. We want to go ahead and format this
 949                          *    flash. While formating, the faulty PEBs will
 950                          *    probably be marked as bad.
 951                          *
 952                          * 2. Flash probably contains non-UBI data and we do
 953                          * not want to format it and destroy possibly needed
 954                          * data (e.g., consider the case when the bootloader
 955                          * MTD partition was accidentally fed to UBI).
 956                          */
 957                         si->is_empty = 1;
 958                         ubi_msg("empty MTD device detected");
 959                         get_random_bytes(&ubi->image_seq, sizeof(ubi->image_seq));
 960                 } else {
 961                         ubi_err("MTD device possibly contains non-UBI data, "
 962                                 "refusing it");
 963                         return -EINVAL;
 964                 }
 965         }
 966
 967         if (si->corr_peb_count > 0)
 968                 ubi_msg("corrupted PEBs will be formatted");
 969         return 0;
 970 }
 971
 972 /**
 973  * ubi_scan - scan an MTD device.
 974  * @ubi: UBI device description object
 975  *
 976  * This function does full scanning of an MTD device and returns complete
 977  * information about it. In case of failure, an error code is returned.
 978  */
 979 struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
 980 {
 981         int err, pnum;
 982         struct rb_node *rb1, *rb2;
 983         struct ubi_scan_volume *sv;
 984         struct ubi_scan_leb *seb;
 985         struct ubi_scan_info *si;
 986
 987         si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
 988         if (!si)
 989                 return ERR_PTR(-ENOMEM);
 990
 991         INIT_LIST_HEAD(&si->corr);
 992         INIT_LIST_HEAD(&si->free);
 993         INIT_LIST_HEAD(&si->erase);
 994         INIT_LIST_HEAD(&si->alien);
 995         si->volumes = RB_ROOT;
 996
 997         err = -ENOMEM;
 998         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 999         if (!ech)
1000                 goto out_si;
1001
1002         vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
1003         if (!vidh)
1004                 goto out_ech;
1005
1006         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1007                 cond_resched();
1008
1009                 dbg_gen("process PEB %d", pnum);
1010                 err = process_eb(ubi, si, pnum);
1011                 if (err < 0)
1012                         goto out_vidh;
1013         }
1014
1015         dbg_msg("scanning is finished");
1016
1017         /* Calculate mean erase counter */
1018         if (si->ec_count)
1019                 si->mean_ec = div_u64(si->ec_sum, si->ec_count);
1020
1021         err = check_what_we_have(ubi, si);
1022         if (err)
1023                 goto out_vidh;
1024
1025         /*
1026          * In case of unknown erase counter we use the mean erase counter
1027          * value.
1028          */
1029         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1030                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1031                         if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1032                                 seb->ec = si->mean_ec;
1033         }
1034
1035         list_for_each_entry(seb, &si->free, u.list) {
1036                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1037                         seb->ec = si->mean_ec;
1038         }
1039
1040         list_for_each_entry(seb, &si->corr, u.list)
1041                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1042                         seb->ec = si->mean_ec;
1043
1044         list_for_each_entry(seb, &si->erase, u.list)
1045                 if (seb->ec == UBI_SCAN_UNKNOWN_EC)
1046                         seb->ec = si->mean_ec;
1047
1048         err = paranoid_check_si(ubi, si);
1049         if (err)
1050                 goto out_vidh;
1051
1052         ubi_free_vid_hdr(ubi, vidh);
1053         kfree(ech);
1054
1055         return si;
1056
1057 out_vidh:
1058         ubi_free_vid_hdr(ubi, vidh);
1059 out_ech:
1060         kfree(ech);
1061 out_si:
1062         ubi_scan_destroy_si(si);
1063         return ERR_PTR(err);
1064 }
1065
1066 /**
1067  * destroy_sv - free the scanning volume information
1068  * @sv: scanning volume information
1069  *
1070  * This function destroys the volume RB-tree (@sv->root) and the scanning
1071  * volume information.
1072  */
1073 static void destroy_sv(struct ubi_scan_volume *sv)
1074 {
1075         struct ubi_scan_leb *seb;
1076         struct rb_node *this = sv->root.rb_node;
1077
1078         while (this) {
1079                 if (this->rb_left)
1080                         this = this->rb_left;
1081                 else if (this->rb_right)
1082                         this = this->rb_right;
1083                 else {
1084                         seb = rb_entry(this, struct ubi_scan_leb, u.rb);
1085                         this = rb_parent(this);
1086                         if (this) {
1087                                 if (this->rb_left == &seb->u.rb)
1088                                         this->rb_left = NULL;
1089                                 else
1090                                         this->rb_right = NULL;
1091                         }
1092
1093                         kfree(seb);
1094                 }
1095         }
1096         kfree(sv);
1097 }
1098
1099 /**
1100  * ubi_scan_destroy_si - destroy scanning information.
1101  * @si: scanning information
1102  */
1103 void ubi_scan_destroy_si(struct ubi_scan_info *si)
1104 {
1105         struct ubi_scan_leb *seb, *seb_tmp;
1106         struct ubi_scan_volume *sv;
1107         struct rb_node *rb;
1108
1109         list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
1110                 list_del(&seb->u.list);
1111                 kfree(seb);
1112         }
1113         list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
1114                 list_del(&seb->u.list);
1115                 kfree(seb);
1116         }
1117         list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
1118                 list_del(&seb->u.list);
1119                 kfree(seb);
1120         }
1121         list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
1122                 list_del(&seb->u.list);
1123                 kfree(seb);
1124         }
1125
1126         /* Destroy the volume RB-tree */
1127         rb = si->volumes.rb_node;
1128         while (rb) {
1129                 if (rb->rb_left)
1130                         rb = rb->rb_left;
1131                 else if (rb->rb_right)
1132                         rb = rb->rb_right;
1133                 else {
1134                         sv = rb_entry(rb, struct ubi_scan_volume, rb);
1135
1136                         rb = rb_parent(rb);
1137                         if (rb) {
1138                                 if (rb->rb_left == &sv->rb)
1139                                         rb->rb_left = NULL;
1140                                 else
1141                                         rb->rb_right = NULL;
1142                         }
1143
1144                         destroy_sv(sv);
1145                 }
1146         }
1147
1148         kfree(si);
1149 }
1150
1151 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1152
1153 /**
1154  * paranoid_check_si - check the scanning information.
1155  * @ubi: UBI device description object
1156  * @si: scanning information
1157  *
1158  * This function returns zero if the scanning information is all right, and a
1159  * negative error code if not or if an error occurred.
1160  */
1161 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
1162 {
1163         int pnum, err, vols_found = 0;
1164         struct rb_node *rb1, *rb2;
1165         struct ubi_scan_volume *sv;
1166         struct ubi_scan_leb *seb, *last_seb;
1167         uint8_t *buf;
1168
1169         /*
1170          * At first, check that scanning information is OK.
1171          */
1172         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1173                 int leb_count = 0;
1174
1175                 cond_resched();
1176
1177                 vols_found += 1;
1178
1179                 if (si->is_empty) {
1180                         ubi_err("bad is_empty flag");
1181                         goto bad_sv;
1182                 }
1183
1184                 if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
1185                     sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
1186                     sv->data_pad < 0 || sv->last_data_size < 0) {
1187                         ubi_err("negative values");
1188                         goto bad_sv;
1189                 }
1190
1191                 if (sv->vol_id >= UBI_MAX_VOLUMES &&
1192                     sv->vol_id < UBI_INTERNAL_VOL_START) {
1193                         ubi_err("bad vol_id");
1194                         goto bad_sv;
1195                 }
1196
1197                 if (sv->vol_id > si->highest_vol_id) {
1198                         ubi_err("highest_vol_id is %d, but vol_id %d is there",
1199                                 si->highest_vol_id, sv->vol_id);
1200                         goto out;
1201                 }
1202
1203                 if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
1204                     sv->vol_type != UBI_STATIC_VOLUME) {
1205                         ubi_err("bad vol_type");
1206                         goto bad_sv;
1207                 }
1208
1209                 if (sv->data_pad > ubi->leb_size / 2) {
1210                         ubi_err("bad data_pad");
1211                         goto bad_sv;
1212                 }
1213
1214                 last_seb = NULL;
1215                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1216                         cond_resched();
1217
1218                         last_seb = seb;
1219                         leb_count += 1;
1220
1221                         if (seb->pnum < 0 || seb->ec < 0) {
1222                                 ubi_err("negative values");
1223                                 goto bad_seb;
1224                         }
1225
1226                         if (seb->ec < si->min_ec) {
1227                                 ubi_err("bad si->min_ec (%d), %d found",
1228                                         si->min_ec, seb->ec);
1229                                 goto bad_seb;
1230                         }
1231
1232                         if (seb->ec > si->max_ec) {
1233                                 ubi_err("bad si->max_ec (%d), %d found",
1234                                         si->max_ec, seb->ec);
1235                                 goto bad_seb;
1236                         }
1237
1238                         if (seb->pnum >= ubi->peb_count) {
1239                                 ubi_err("too high PEB number %d, total PEBs %d",
1240                                         seb->pnum, ubi->peb_count);
1241                                 goto bad_seb;
1242                         }
1243
1244                         if (sv->vol_type == UBI_STATIC_VOLUME) {
1245                                 if (seb->lnum >= sv->used_ebs) {
1246                                         ubi_err("bad lnum or used_ebs");
1247                                         goto bad_seb;
1248                                 }
1249                         } else {
1250                                 if (sv->used_ebs != 0) {
1251                                         ubi_err("non-zero used_ebs");
1252                                         goto bad_seb;
1253                                 }
1254                         }
1255
1256                         if (seb->lnum > sv->highest_lnum) {
1257                                 ubi_err("incorrect highest_lnum or lnum");
1258                                 goto bad_seb;
1259                         }
1260                 }
1261
1262                 if (sv->leb_count != leb_count) {
1263                         ubi_err("bad leb_count, %d objects in the tree",
1264                                 leb_count);
1265                         goto bad_sv;
1266                 }
1267
1268                 if (!last_seb)
1269                         continue;
1270
1271                 seb = last_seb;
1272
1273                 if (seb->lnum != sv->highest_lnum) {
1274                         ubi_err("bad highest_lnum");
1275                         goto bad_seb;
1276                 }
1277         }
1278
1279         if (vols_found != si->vols_found) {
1280                 ubi_err("bad si->vols_found %d, should be %d",
1281                         si->vols_found, vols_found);
1282                 goto out;
1283         }
1284
1285         /* Check that scanning information is correct */
1286         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
1287                 last_seb = NULL;
1288                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
1289                         int vol_type;
1290
1291                         cond_resched();
1292
1293                         last_seb = seb;
1294
1295                         err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
1296                         if (err && err != UBI_IO_BITFLIPS) {
1297                                 ubi_err("VID header is not OK (%d)", err);
1298                                 if (err > 0)
1299                                         err = -EIO;
1300                                 return err;
1301                         }
1302
1303                         vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
1304                                    UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
1305                         if (sv->vol_type != vol_type) {
1306                                 ubi_err("bad vol_type");
1307                                 goto bad_vid_hdr;
1308                         }
1309
1310                         if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
1311                                 ubi_err("bad sqnum %llu", seb->sqnum);
1312                                 goto bad_vid_hdr;
1313                         }
1314
1315                         if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
1316                                 ubi_err("bad vol_id %d", sv->vol_id);
1317                                 goto bad_vid_hdr;
1318                         }
1319
1320                         if (sv->compat != vidh->compat) {
1321                                 ubi_err("bad compat %d", vidh->compat);
1322                                 goto bad_vid_hdr;
1323                         }
1324
1325                         if (seb->lnum != be32_to_cpu(vidh->lnum)) {
1326                                 ubi_err("bad lnum %d", seb->lnum);
1327                                 goto bad_vid_hdr;
1328                         }
1329
1330                         if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
1331                                 ubi_err("bad used_ebs %d", sv->used_ebs);
1332                                 goto bad_vid_hdr;
1333                         }
1334
1335                         if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
1336                                 ubi_err("bad data_pad %d", sv->data_pad);
1337                                 goto bad_vid_hdr;
1338                         }
1339                 }
1340
1341                 if (!last_seb)
1342                         continue;
1343
1344                 if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
1345                         ubi_err("bad highest_lnum %d", sv->highest_lnum);
1346                         goto bad_vid_hdr;
1347                 }
1348
1349                 if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
1350                         ubi_err("bad last_data_size %d", sv->last_data_size);
1351                         goto bad_vid_hdr;
1352                 }
1353         }
1354
1355         /*
1356          * Make sure that all the physical eraseblocks are in one of the lists
1357          * or trees.
1358          */
1359         buf = kzalloc(ubi->peb_count, GFP_KERNEL);
1360         if (!buf)
1361                 return -ENOMEM;
1362
1363         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
1364                 err = ubi_io_is_bad(ubi, pnum);
1365                 if (err < 0) {
1366                         kfree(buf);
1367                         return err;
1368                 } else if (err)
1369                         buf[pnum] = 1;
1370         }
1371
1372         ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
1373                 ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
1374                         buf[seb->pnum] = 1;
1375
1376         list_for_each_entry(seb, &si->free, u.list)
1377                 buf[seb->pnum] = 1;
1378
1379         list_for_each_entry(seb, &si->corr, u.list)
1380                 buf[seb->pnum] = 1;
1381
1382         list_for_each_entry(seb, &si->erase, u.list)
1383                 buf[seb->pnum] = 1;
1384
1385         list_for_each_entry(seb, &si->alien, u.list)
1386                 buf[seb->pnum] = 1;
1387
1388         err = 0;
1389         for (pnum = 0; pnum < ubi->peb_count; pnum++)
1390                 if (!buf[pnum]) {
1391                         ubi_err("PEB %d is not referred", pnum);
1392                         err = 1;
1393                 }
1394
1395         kfree(buf);
1396         if (err)
1397                 goto out;
1398         return 0;
1399
1400 bad_seb:
1401         ubi_err("bad scanning information about LEB %d", seb->lnum);
1402         ubi_dbg_dump_seb(seb, 0);
1403         ubi_dbg_dump_sv(sv);
1404         goto out;
1405
1406 bad_sv:
1407         ubi_err("bad scanning information about volume %d", sv->vol_id);
1408         ubi_dbg_dump_sv(sv);
1409         goto out;
1410
1411 bad_vid_hdr:
1412         ubi_err("bad scanning information about volume %d", sv->vol_id);
1413         ubi_dbg_dump_sv(sv);
1414         ubi_dbg_dump_vid_hdr(vidh);
1415
1416 out:
1417         ubi_dbg_dump_stack();
1418         return -EINVAL;
1419 }
1420
1421 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */