drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Copyright (c) 2014 sigma star gmbh
   4  * Author: Richard Weinberger <richard@nod.at>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/crc32.h>
  18 #include <linux/bitmap.h>
  19 #include "ubi.h"
  20
  21 /**
  22  * init_seen - allocate memory for used for debugging.
  23  * @ubi: UBI device description object
  24  */
  25 static inline unsigned long *init_seen(struct ubi_device *ubi)
  26 {
  27         unsigned long *ret;
  28
  29         if (!ubi_dbg_chk_fastmap(ubi))
  30                 return NULL;
  31
  32         ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  33                       GFP_KERNEL);
  34         if (!ret)
  35                 return ERR_PTR(-ENOMEM);
  36
  37         return ret;
  38 }
  39
  40 /**
  41  * free_seen - free the seen logic integer array.
  42  * @seen: integer array of @ubi->peb_count size
  43  */
  44 static inline void free_seen(unsigned long *seen)
  45 {
  46         kfree(seen);
  47 }
  48
  49 /**
  50  * set_seen - mark a PEB as seen.
  51  * @ubi: UBI device description object
  52  * @pnum: The PEB to be makred as seen
  53  * @seen: integer array of @ubi->peb_count size
  54  */
  55 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  56 {
  57         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  58                 return;
  59
  60         set_bit(pnum, seen);
  61 }
  62
  63 /**
  64  * self_check_seen - check whether all PEB have been seen by fastmap.
  65  * @ubi: UBI device description object
  66  * @seen: integer array of @ubi->peb_count size
  67  */
  68 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  69 {
  70         int pnum, ret = 0;
  71
  72         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  73                 return 0;
  74
  75         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  76                 if (test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  77                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  78                         ret = -EINVAL;
  79                 }
  80         }
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  87  * @ubi: UBI device description object
  88  */
  89 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  90 {
  91         size_t size;
  92
  93         size = sizeof(struct ubi_fm_sb) +
  94                 sizeof(struct ubi_fm_hdr) +
  95                 sizeof(struct ubi_fm_scan_pool) +
  96                 sizeof(struct ubi_fm_scan_pool) +
  97                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  98                 (sizeof(struct ubi_fm_eba) +
  99                 (ubi->peb_count * sizeof(__be32))) +
 100                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
 101         return roundup(size, ubi->leb_size);
 102 }
 103
 104
 105 /**
 106  * new_fm_vhdr - allocate a new volume header for fastmap usage.
 107  * @ubi: UBI device description object
 108  * @vol_id: the VID of the new header
 109  *
 110  * Returns a new struct ubi_vid_hdr on success.
 111  * NULL indicates out of memory.
 112  */
 113 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
 114 {
 115         struct ubi_vid_hdr *new;
 116
 117         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 118         if (!new)
 119                 goto out;
 120
 121         new->vol_type = UBI_VID_DYNAMIC;
 122         new->vol_id = cpu_to_be32(vol_id);
 123
 124         /* UBI implementations without fastmap support have to delete the
 125          * fastmap.
 126          */
 127         new->compat = UBI_COMPAT_DELETE;
 128
 129 out:
 130         return new;
 131 }
 132
 133 /**
 134  * add_aeb - create and add a attach erase block to a given list.
 135  * @ai: UBI attach info object
 136  * @list: the target list
 137  * @pnum: PEB number of the new attach erase block
 138  * @ec: erease counter of the new LEB
 139  * @scrub: scrub this PEB after attaching
 140  *
 141  * Returns 0 on success, < 0 indicates an internal error.
 142  */
 143 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 144                    int pnum, int ec, int scrub)
 145 {
 146         struct ubi_ainf_peb *aeb;
 147
 148         aeb = ubi_alloc_aeb(ai, pnum, ec);
 149         if (!aeb)
 150                 return -ENOMEM;
 151
 152         aeb->lnum = -1;
 153         aeb->scrub = scrub;
 154         aeb->copy_flag = aeb->sqnum = 0;
 155
 156         ai->ec_sum += aeb->ec;
 157         ai->ec_count++;
 158
 159         if (ai->max_ec < aeb->ec)
 160                 ai->max_ec = aeb->ec;
 161
 162         if (ai->min_ec > aeb->ec)
 163                 ai->min_ec = aeb->ec;
 164
 165         list_add_tail(&aeb->u.list, list);
 166
 167         return 0;
 168 }
 169
 170 /**
 171  * add_vol - create and add a new volume to ubi_attach_info.
 172  * @ai: ubi_attach_info object
 173  * @vol_id: VID of the new volume
 174  * @used_ebs: number of used EBS
 175  * @data_pad: data padding value of the new volume
 176  * @vol_type: volume type
 177  * @last_eb_bytes: number of bytes in the last LEB
 178  *
 179  * Returns the new struct ubi_ainf_volume on success.
 180  * NULL indicates an error.
 181  */
 182 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 183                                        int used_ebs, int data_pad, u8 vol_type,
 184                                        int last_eb_bytes)
 185 {
 186         struct ubi_ainf_volume *av;
 187
 188         av = ubi_add_av(ai, vol_id);
 189         if (IS_ERR(av))
 190                 return av;
 191
 192         av->data_pad = data_pad;
 193         av->last_data_size = last_eb_bytes;
 194         av->compat = 0;
 195         av->vol_type = vol_type;
 196         if (av->vol_type == UBI_STATIC_VOLUME)
 197                 av->used_ebs = used_ebs;
 198
 199         dbg_bld("found volume (ID %i)", vol_id);
 200         return av;
 201 }
 202
 203 /**
 204  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 205  * from it's original list.
 206  * @ai: ubi_attach_info object
 207  * @aeb: the to be assigned SEB
 208  * @av: target scan volume
 209  */
 210 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 211                              struct ubi_ainf_peb *aeb,
 212                              struct ubi_ainf_volume *av)
 213 {
 214         struct ubi_ainf_peb *tmp_aeb;
 215         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 216
 217         p = &av->root.rb_node;
 218         while (*p) {
 219                 parent = *p;
 220
 221                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 222                 if (aeb->lnum != tmp_aeb->lnum) {
 223                         if (aeb->lnum < tmp_aeb->lnum)
 224                                 p = &(*p)->rb_left;
 225                         else
 226                                 p = &(*p)->rb_right;
 227
 228                         continue;
 229                 } else
 230                         break;
 231         }
 232
 233         list_del(&aeb->u.list);
 234         av->leb_count++;
 235
 236         rb_link_node(&aeb->u.rb, parent, p);
 237         rb_insert_color(&aeb->u.rb, &av->root);
 238 }
 239
 240 /**
 241  * update_vol - inserts or updates a LEB which was found a pool.
 242  * @ubi: the UBI device object
 243  * @ai: attach info object
 244  * @av: the volume this LEB belongs to
 245  * @new_vh: the volume header derived from new_aeb
 246  * @new_aeb: the AEB to be examined
 247  *
 248  * Returns 0 on success, < 0 indicates an internal error.
 249  */
 250 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 251                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 252                       struct ubi_ainf_peb *new_aeb)
 253 {
 254         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 255         struct ubi_ainf_peb *aeb, *victim;
 256         int cmp_res;
 257
 258         while (*p) {
 259                 parent = *p;
 260                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 261
 262                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 263                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 264                                 p = &(*p)->rb_left;
 265                         else
 266                                 p = &(*p)->rb_right;
 267
 268                         continue;
 269                 }
 270
 271                 /* This case can happen if the fastmap gets written
 272                  * because of a volume change (creation, deletion, ..).
 273                  * Then a PEB can be within the persistent EBA and the pool.
 274                  */
 275                 if (aeb->pnum == new_aeb->pnum) {
 276                         ubi_assert(aeb->lnum == new_aeb->lnum);
 277                         ubi_free_aeb(ai, new_aeb);
 278
 279                         return 0;
 280                 }
 281
 282                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 283                 if (cmp_res < 0)
 284                         return cmp_res;
 285
 286                 /* new_aeb is newer */
 287                 if (cmp_res & 1) {
 288                         victim = ubi_alloc_aeb(ai, aeb->ec, aeb->pnum);
 289                         if (!victim)
 290                                 return -ENOMEM;
 291
 292                         list_add_tail(&victim->u.list, &ai->erase);
 293
 294                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 295                                 av->last_data_size =
 296                                         be32_to_cpu(new_vh->data_size);
 297
 298                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 299                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 300
 301                         aeb->ec = new_aeb->ec;
 302                         aeb->pnum = new_aeb->pnum;
 303                         aeb->copy_flag = new_vh->copy_flag;
 304                         aeb->scrub = new_aeb->scrub;
 305                         ubi_free_aeb(ai, new_aeb);
 306
 307                 /* new_aeb is older */
 308                 } else {
 309                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 310                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 311                         list_add_tail(&new_aeb->u.list, &ai->erase);
 312                 }
 313
 314                 return 0;
 315         }
 316         /* This LEB is new, let's add it to the volume */
 317
 318         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 319                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 320                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 321         }
 322
 323         if (av->vol_type == UBI_STATIC_VOLUME)
 324                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 325
 326         av->leb_count++;
 327
 328         rb_link_node(&new_aeb->u.rb, parent, p);
 329         rb_insert_color(&new_aeb->u.rb, &av->root);
 330
 331         return 0;
 332 }
 333
 334 /**
 335  * process_pool_aeb - we found a non-empty PEB in a pool.
 336  * @ubi: UBI device object
 337  * @ai: attach info object
 338  * @new_vh: the volume header derived from new_aeb
 339  * @new_aeb: the AEB to be examined
 340  *
 341  * Returns 0 on success, < 0 indicates an internal error.
 342  */
 343 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 344                             struct ubi_vid_hdr *new_vh,
 345                             struct ubi_ainf_peb *new_aeb)
 346 {
 347         int vol_id = be32_to_cpu(new_vh->vol_id);
 348         struct ubi_ainf_volume *av;
 349
 350         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 351                 ubi_free_aeb(ai, new_aeb);
 352
 353                 return 0;
 354         }
 355
 356         /* Find the volume this SEB belongs to */
 357         av = ubi_find_av(ai, vol_id);
 358         if (!av) {
 359                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 360                 ubi_free_aeb(ai, new_aeb);
 361                 return UBI_BAD_FASTMAP;
 362         }
 363
 364         ubi_assert(vol_id == av->vol_id);
 365
 366         return update_vol(ubi, ai, av, new_vh, new_aeb);
 367 }
 368
 369 /**
 370  * unmap_peb - unmap a PEB.
 371  * If fastmap detects a free PEB in the pool it has to check whether
 372  * this PEB has been unmapped after writing the fastmap.
 373  *
 374  * @ai: UBI attach info object
 375  * @pnum: The PEB to be unmapped
 376  */
 377 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 378 {
 379         struct ubi_ainf_volume *av;
 380         struct rb_node *node, *node2;
 381         struct ubi_ainf_peb *aeb;
 382
 383         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 384                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 385                         if (aeb->pnum == pnum) {
 386                                 rb_erase(&aeb->u.rb, &av->root);
 387                                 av->leb_count--;
 388                                 ubi_free_aeb(ai, aeb);
 389                                 return;
 390                         }
 391                 }
 392         }
 393 }
 394
 395 /**
 396  * scan_pool - scans a pool for changed (no longer empty PEBs).
 397  * @ubi: UBI device object
 398  * @ai: attach info object
 399  * @pebs: an array of all PEB numbers in the to be scanned pool
 400  * @pool_size: size of the pool (number of entries in @pebs)
 401  * @max_sqnum: pointer to the maximal sequence number
 402  * @free: list of PEBs which are most likely free (and go into @ai->free)
 403  *
 404  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 405  * < 0 indicates an internal error.
 406  */
 407 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 408                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 409                      struct list_head *free)
 410 {
 411         struct ubi_vid_hdr *vh;
 412         struct ubi_ec_hdr *ech;
 413         struct ubi_ainf_peb *new_aeb;
 414         int i, pnum, err, ret = 0;
 415
 416         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 417         if (!ech)
 418                 return -ENOMEM;
 419
 420         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 421         if (!vh) {
 422                 kfree(ech);
 423                 return -ENOMEM;
 424         }
 425
 426         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 427
 428         /*
 429          * Now scan all PEBs in the pool to find changes which have been made
 430          * after the creation of the fastmap
 431          */
 432         for (i = 0; i < pool_size; i++) {
 433                 int scrub = 0;
 434                 int image_seq;
 435
 436                 pnum = be32_to_cpu(pebs[i]);
 437
 438                 if (ubi_io_is_bad(ubi, pnum)) {
 439                         ubi_err(ubi, "bad PEB in fastmap pool!");
 440                         ret = UBI_BAD_FASTMAP;
 441                         goto out;
 442                 }
 443
 444                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 445                 if (err && err != UBI_IO_BITFLIPS) {
 446                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 447                                 pnum, err);
 448                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 449                         goto out;
 450                 } else if (err == UBI_IO_BITFLIPS)
 451                         scrub = 1;
 452
 453                 /*
 454                  * Older UBI implementations have image_seq set to zero, so
 455                  * we shouldn't fail if image_seq == 0.
 456                  */
 457                 image_seq = be32_to_cpu(ech->image_seq);
 458
 459                 if (image_seq && (image_seq != ubi->image_seq)) {
 460                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 461                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 462                         ret = UBI_BAD_FASTMAP;
 463                         goto out;
 464                 }
 465
 466                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 467                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 468                         unsigned long long ec = be64_to_cpu(ech->ec);
 469                         unmap_peb(ai, pnum);
 470                         dbg_bld("Adding PEB to free: %i", pnum);
 471
 472                         if (err == UBI_IO_FF_BITFLIPS)
 473                                 scrub = 1;
 474
 475                         add_aeb(ai, free, pnum, ec, scrub);
 476                         continue;
 477                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 478                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 479
 480                         if (err == UBI_IO_BITFLIPS)
 481                                 scrub = 1;
 482
 483                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 484                         if (!new_aeb) {
 485                                 ret = -ENOMEM;
 486                                 goto out;
 487                         }
 488
 489                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 490                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 491                         new_aeb->copy_flag = vh->copy_flag;
 492                         new_aeb->scrub = scrub;
 493
 494                         if (*max_sqnum < new_aeb->sqnum)
 495                                 *max_sqnum = new_aeb->sqnum;
 496
 497                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 498                         if (err) {
 499                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 500                                 goto out;
 501                         }
 502                 } else {
 503                         /* We are paranoid and fall back to scanning mode */
 504                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 505                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 506                         goto out;
 507                 }
 508
 509         }
 510
 511 out:
 512         ubi_free_vid_hdr(ubi, vh);
 513         kfree(ech);
 514         return ret;
 515 }
 516
 517 /**
 518  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 519  * @ai: The UBI attach info object
 520  */
 521 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 522 {
 523         struct ubi_ainf_peb *aeb;
 524         struct ubi_ainf_volume *av;
 525         struct rb_node *rb1, *rb2;
 526         int n = 0;
 527
 528         list_for_each_entry(aeb, &ai->erase, u.list)
 529                 n++;
 530
 531         list_for_each_entry(aeb, &ai->free, u.list)
 532                 n++;
 533
 534         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 535                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 536                         n++;
 537
 538         return n;
 539 }
 540
 541 /**
 542  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 543  * @ubi: UBI device object
 544  * @ai: UBI attach info object
 545  * @fm: the fastmap to be attached
 546  *
 547  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 548  * < 0 indicates an internal error.
 549  */
 550 static int ubi_attach_fastmap(struct ubi_device *ubi,
 551                               struct ubi_attach_info *ai,
 552                               struct ubi_fastmap_layout *fm)
 553 {
 554         struct list_head used, free;
 555         struct ubi_ainf_volume *av;
 556         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 557         struct ubi_fm_sb *fmsb;
 558         struct ubi_fm_hdr *fmhdr;
 559         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 560         struct ubi_fm_ec *fmec;
 561         struct ubi_fm_volhdr *fmvhdr;
 562         struct ubi_fm_eba *fm_eba;
 563         int ret, i, j, pool_size, wl_pool_size;
 564         size_t fm_pos = 0, fm_size = ubi->fm_size;
 565         unsigned long long max_sqnum = 0;
 566         void *fm_raw = ubi->fm_buf;
 567
 568         INIT_LIST_HEAD(&used);
 569         INIT_LIST_HEAD(&free);
 570         ai->min_ec = UBI_MAX_ERASECOUNTER;
 571
 572         fmsb = (struct ubi_fm_sb *)(fm_raw);
 573         ai->max_sqnum = fmsb->sqnum;
 574         fm_pos += sizeof(struct ubi_fm_sb);
 575         if (fm_pos >= fm_size)
 576                 goto fail_bad;
 577
 578         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 579         fm_pos += sizeof(*fmhdr);
 580         if (fm_pos >= fm_size)
 581                 goto fail_bad;
 582
 583         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 584                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 585                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 586                 goto fail_bad;
 587         }
 588
 589         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 590         fm_pos += sizeof(*fmpl);
 591         if (fm_pos >= fm_size)
 592                 goto fail_bad;
 593         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 594                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 595                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 596                 goto fail_bad;
 597         }
 598
 599         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 600         fm_pos += sizeof(*fmpl_wl);
 601         if (fm_pos >= fm_size)
 602                 goto fail_bad;
 603         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 604                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 605                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 606                 goto fail_bad;
 607         }
 608
 609         pool_size = be16_to_cpu(fmpl->size);
 610         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 611         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 612         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 613
 614         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 615                 ubi_err(ubi, "bad pool size: %i", pool_size);
 616                 goto fail_bad;
 617         }
 618
 619         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 620                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 621                 goto fail_bad;
 622         }
 623
 624
 625         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 626             fm->max_pool_size < 0) {
 627                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 628                 goto fail_bad;
 629         }
 630
 631         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 632             fm->max_wl_pool_size < 0) {
 633                 ubi_err(ubi, "bad maximal WL pool size: %i",
 634                         fm->max_wl_pool_size);
 635                 goto fail_bad;
 636         }
 637
 638         /* read EC values from free list */
 639         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 640                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 641                 fm_pos += sizeof(*fmec);
 642                 if (fm_pos >= fm_size)
 643                         goto fail_bad;
 644
 645                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 646                         be32_to_cpu(fmec->ec), 0);
 647         }
 648
 649         /* read EC values from used list */
 650         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 651                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 652                 fm_pos += sizeof(*fmec);
 653                 if (fm_pos >= fm_size)
 654                         goto fail_bad;
 655
 656                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 657                         be32_to_cpu(fmec->ec), 0);
 658         }
 659
 660         /* read EC values from scrub list */
 661         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 662                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 663                 fm_pos += sizeof(*fmec);
 664                 if (fm_pos >= fm_size)
 665                         goto fail_bad;
 666
 667                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 668                         be32_to_cpu(fmec->ec), 1);
 669         }
 670
 671         /* read EC values from erase list */
 672         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 673                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 674                 fm_pos += sizeof(*fmec);
 675                 if (fm_pos >= fm_size)
 676                         goto fail_bad;
 677
 678                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 679                         be32_to_cpu(fmec->ec), 1);
 680         }
 681
 682         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 683         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 684
 685         /* Iterate over all volumes and read their EBA table */
 686         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 687                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 688                 fm_pos += sizeof(*fmvhdr);
 689                 if (fm_pos >= fm_size)
 690                         goto fail_bad;
 691
 692                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 693                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 694                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 695                         goto fail_bad;
 696                 }
 697
 698                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 699                              be32_to_cpu(fmvhdr->used_ebs),
 700                              be32_to_cpu(fmvhdr->data_pad),
 701                              fmvhdr->vol_type,
 702                              be32_to_cpu(fmvhdr->last_eb_bytes));
 703
 704                 if (!av)
 705                         goto fail_bad;
 706                 if (PTR_ERR(av) == -EINVAL) {
 707                         ubi_err(ubi, "volume (ID %i) already exists",
 708                                 fmvhdr->vol_id);
 709                         goto fail_bad;
 710                 }
 711
 712                 ai->vols_found++;
 713                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 714                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 715
 716                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 717                 fm_pos += sizeof(*fm_eba);
 718                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 719                 if (fm_pos >= fm_size)
 720                         goto fail_bad;
 721
 722                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 723                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 724                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 725                         goto fail_bad;
 726                 }
 727
 728                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 729                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 730
 731                         if (pnum < 0)
 732                                 continue;
 733
 734                         aeb = NULL;
 735                         list_for_each_entry(tmp_aeb, &used, u.list) {
 736                                 if (tmp_aeb->pnum == pnum) {
 737                                         aeb = tmp_aeb;
 738                                         break;
 739                                 }
 740                         }
 741
 742                         if (!aeb) {
 743                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 744                                 goto fail_bad;
 745                         }
 746
 747                         aeb->lnum = j;
 748
 749                         if (av->highest_lnum <= aeb->lnum)
 750                                 av->highest_lnum = aeb->lnum;
 751
 752                         assign_aeb_to_av(ai, aeb, av);
 753
 754                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 755                                 aeb->pnum, aeb->lnum, av->vol_id);
 756                 }
 757         }
 758
 759         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 760         if (ret)
 761                 goto fail;
 762
 763         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 764         if (ret)
 765                 goto fail;
 766
 767         if (max_sqnum > ai->max_sqnum)
 768                 ai->max_sqnum = max_sqnum;
 769
 770         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 771                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 772
 773         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 774                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 775
 776         ubi_assert(list_empty(&free));
 777
 778         /*
 779          * If fastmap is leaking PEBs (must not happen), raise a
 780          * fat warning and fall back to scanning mode.
 781          * We do this here because in ubi_wl_init() it's too late
 782          * and we cannot fall back to scanning.
 783          */
 784         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 785                     ai->bad_peb_count - fm->used_blocks))
 786                 goto fail_bad;
 787
 788         return 0;
 789
 790 fail_bad:
 791         ret = UBI_BAD_FASTMAP;
 792 fail:
 793         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 794                 list_del(&tmp_aeb->u.list);
 795                 ubi_free_aeb(ai, tmp_aeb);
 796         }
 797         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 798                 list_del(&tmp_aeb->u.list);
 799                 ubi_free_aeb(ai, tmp_aeb);
 800         }
 801
 802         return ret;
 803 }
 804
 805 /**
 806  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 807  * @ai: UBI attach info to be filled
 808  */
 809 static int find_fm_anchor(struct ubi_attach_info *ai)
 810 {
 811         int ret = -1;
 812         struct ubi_ainf_peb *aeb;
 813         unsigned long long max_sqnum = 0;
 814
 815         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 816                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 817                         max_sqnum = aeb->sqnum;
 818                         ret = aeb->pnum;
 819                 }
 820         }
 821
 822         return ret;
 823 }
 824
 825 /**
 826  * ubi_scan_fastmap - scan the fastmap.
 827  * @ubi: UBI device object
 828  * @ai: UBI attach info to be filled
 829  * @scan_ai: UBI attach info from the first 64 PEBs,
 830  *           used to find the most recent Fastmap data structure
 831  *
 832  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 833  * UBI_BAD_FASTMAP if one was found but is not usable.
 834  * < 0 indicates an internal error.
 835  */
 836 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 837                      struct ubi_attach_info *scan_ai)
 838 {
 839         struct ubi_fm_sb *fmsb, *fmsb2;
 840         struct ubi_vid_hdr *vh;
 841         struct ubi_ec_hdr *ech;
 842         struct ubi_fastmap_layout *fm;
 843         struct ubi_ainf_peb *tmp_aeb, *aeb;
 844         int i, used_blocks, pnum, fm_anchor, ret = 0;
 845         size_t fm_size;
 846         __be32 crc, tmp_crc;
 847         unsigned long long sqnum = 0;
 848
 849         fm_anchor = find_fm_anchor(scan_ai);
 850         if (fm_anchor < 0)
 851                 return UBI_NO_FASTMAP;
 852
 853         /* Move all (possible) fastmap blocks into our new attach structure. */
 854         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 855                 list_move_tail(&aeb->u.list, &ai->fastmap);
 856
 857         down_write(&ubi->fm_protect);
 858         memset(ubi->fm_buf, 0, ubi->fm_size);
 859
 860         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 861         if (!fmsb) {
 862                 ret = -ENOMEM;
 863                 goto out;
 864         }
 865
 866         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 867         if (!fm) {
 868                 ret = -ENOMEM;
 869                 kfree(fmsb);
 870                 goto out;
 871         }
 872
 873         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 874         if (ret && ret != UBI_IO_BITFLIPS)
 875                 goto free_fm_sb;
 876         else if (ret == UBI_IO_BITFLIPS)
 877                 fm->to_be_tortured[0] = 1;
 878
 879         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 880                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 881                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 882                 ret = UBI_BAD_FASTMAP;
 883                 goto free_fm_sb;
 884         }
 885
 886         if (fmsb->version != UBI_FM_FMT_VERSION) {
 887                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 888                         fmsb->version, UBI_FM_FMT_VERSION);
 889                 ret = UBI_BAD_FASTMAP;
 890                 goto free_fm_sb;
 891         }
 892
 893         used_blocks = be32_to_cpu(fmsb->used_blocks);
 894         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 895                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 896                         used_blocks);
 897                 ret = UBI_BAD_FASTMAP;
 898                 goto free_fm_sb;
 899         }
 900
 901         fm_size = ubi->leb_size * used_blocks;
 902         if (fm_size != ubi->fm_size) {
 903                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 904                         fm_size, ubi->fm_size);
 905                 ret = UBI_BAD_FASTMAP;
 906                 goto free_fm_sb;
 907         }
 908
 909         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 910         if (!ech) {
 911                 ret = -ENOMEM;
 912                 goto free_fm_sb;
 913         }
 914
 915         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 916         if (!vh) {
 917                 ret = -ENOMEM;
 918                 goto free_hdr;
 919         }
 920
 921         for (i = 0; i < used_blocks; i++) {
 922                 int image_seq;
 923
 924                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 925
 926                 if (ubi_io_is_bad(ubi, pnum)) {
 927                         ret = UBI_BAD_FASTMAP;
 928                         goto free_hdr;
 929                 }
 930
 931                 if (i == 0 && pnum != fm_anchor) {
 932                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 933                                 pnum, fm_anchor);
 934                         ret = UBI_BAD_FASTMAP;
 935                         goto free_hdr;
 936                 }
 937
 938                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 939                 if (ret && ret != UBI_IO_BITFLIPS) {
 940                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 941                                 i, pnum);
 942                         if (ret > 0)
 943                                 ret = UBI_BAD_FASTMAP;
 944                         goto free_hdr;
 945                 } else if (ret == UBI_IO_BITFLIPS)
 946                         fm->to_be_tortured[i] = 1;
 947
 948                 image_seq = be32_to_cpu(ech->image_seq);
 949                 if (!ubi->image_seq)
 950                         ubi->image_seq = image_seq;
 951
 952                 /*
 953                  * Older UBI implementations have image_seq set to zero, so
 954                  * we shouldn't fail if image_seq == 0.
 955                  */
 956                 if (image_seq && (image_seq != ubi->image_seq)) {
 957                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 958                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 959                         ret = UBI_BAD_FASTMAP;
 960                         goto free_hdr;
 961                 }
 962
 963                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 964                 if (ret && ret != UBI_IO_BITFLIPS) {
 965                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 966                                 i, pnum);
 967                         goto free_hdr;
 968                 }
 969
 970                 if (i == 0) {
 971                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 972                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 973                                         be32_to_cpu(vh->vol_id),
 974                                         UBI_FM_SB_VOLUME_ID);
 975                                 ret = UBI_BAD_FASTMAP;
 976                                 goto free_hdr;
 977                         }
 978                 } else {
 979                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 980                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 981                                         be32_to_cpu(vh->vol_id),
 982                                         UBI_FM_DATA_VOLUME_ID);
 983                                 ret = UBI_BAD_FASTMAP;
 984                                 goto free_hdr;
 985                         }
 986                 }
 987
 988                 if (sqnum < be64_to_cpu(vh->sqnum))
 989                         sqnum = be64_to_cpu(vh->sqnum);
 990
 991                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
 992                                        pnum, 0, ubi->leb_size);
 993                 if (ret && ret != UBI_IO_BITFLIPS) {
 994                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
 995                                 "err: %i)", i, pnum, ret);
 996                         goto free_hdr;
 997                 }
 998         }
 999
1000         kfree(fmsb);
1001         fmsb = NULL;
1002
1003         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1004         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1005         fmsb2->data_crc = 0;
1006         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1007         if (crc != tmp_crc) {
1008                 ubi_err(ubi, "fastmap data CRC is invalid");
1009                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1010                         tmp_crc, crc);
1011                 ret = UBI_BAD_FASTMAP;
1012                 goto free_hdr;
1013         }
1014
1015         fmsb2->sqnum = sqnum;
1016
1017         fm->used_blocks = used_blocks;
1018
1019         ret = ubi_attach_fastmap(ubi, ai, fm);
1020         if (ret) {
1021                 if (ret > 0)
1022                         ret = UBI_BAD_FASTMAP;
1023                 goto free_hdr;
1024         }
1025
1026         for (i = 0; i < used_blocks; i++) {
1027                 struct ubi_wl_entry *e;
1028
1029                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1030                 if (!e) {
1031                         while (i--)
1032                                 kfree(fm->e[i]);
1033
1034                         ret = -ENOMEM;
1035                         goto free_hdr;
1036                 }
1037
1038                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1039                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1040                 fm->e[i] = e;
1041         }
1042
1043         ubi->fm = fm;
1044         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1045         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1046         ubi_msg(ubi, "attached by fastmap");
1047         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1048         ubi_msg(ubi, "fastmap WL pool size: %d",
1049                 ubi->fm_wl_pool.max_size);
1050         ubi->fm_disabled = 0;
1051         ubi->fast_attach = 1;
1052
1053         ubi_free_vid_hdr(ubi, vh);
1054         kfree(ech);
1055 out:
1056         up_write(&ubi->fm_protect);
1057         if (ret == UBI_BAD_FASTMAP)
1058                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1059         return ret;
1060
1061 free_hdr:
1062         ubi_free_vid_hdr(ubi, vh);
1063         kfree(ech);
1064 free_fm_sb:
1065         kfree(fmsb);
1066         kfree(fm);
1067         goto out;
1068 }
1069
1070 /**
1071  * ubi_write_fastmap - writes a fastmap.
1072  * @ubi: UBI device object
1073  * @new_fm: the to be written fastmap
1074  *
1075  * Returns 0 on success, < 0 indicates an internal error.
1076  */
1077 static int ubi_write_fastmap(struct ubi_device *ubi,
1078                              struct ubi_fastmap_layout *new_fm)
1079 {
1080         size_t fm_pos = 0;
1081         void *fm_raw;
1082         struct ubi_fm_sb *fmsb;
1083         struct ubi_fm_hdr *fmh;
1084         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1085         struct ubi_fm_ec *fec;
1086         struct ubi_fm_volhdr *fvh;
1087         struct ubi_fm_eba *feba;
1088         struct ubi_wl_entry *wl_e;
1089         struct ubi_volume *vol;
1090         struct ubi_vid_hdr *avhdr, *dvhdr;
1091         struct ubi_work *ubi_wrk;
1092         struct rb_node *tmp_rb;
1093         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1094         int scrub_peb_count, erase_peb_count;
1095         unsigned long *seen_pebs = NULL;
1096
1097         fm_raw = ubi->fm_buf;
1098         memset(ubi->fm_buf, 0, ubi->fm_size);
1099
1100         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1101         if (!avhdr) {
1102                 ret = -ENOMEM;
1103                 goto out;
1104         }
1105
1106         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1107         if (!dvhdr) {
1108                 ret = -ENOMEM;
1109                 goto out_kfree;
1110         }
1111
1112         seen_pebs = init_seen(ubi);
1113         if (IS_ERR(seen_pebs)) {
1114                 ret = PTR_ERR(seen_pebs);
1115                 goto out_kfree;
1116         }
1117
1118         spin_lock(&ubi->volumes_lock);
1119         spin_lock(&ubi->wl_lock);
1120
1121         fmsb = (struct ubi_fm_sb *)fm_raw;
1122         fm_pos += sizeof(*fmsb);
1123         ubi_assert(fm_pos <= ubi->fm_size);
1124
1125         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1126         fm_pos += sizeof(*fmh);
1127         ubi_assert(fm_pos <= ubi->fm_size);
1128
1129         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1130         fmsb->version = UBI_FM_FMT_VERSION;
1131         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1132         /* the max sqnum will be filled in while *reading* the fastmap */
1133         fmsb->sqnum = 0;
1134
1135         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1136         free_peb_count = 0;
1137         used_peb_count = 0;
1138         scrub_peb_count = 0;
1139         erase_peb_count = 0;
1140         vol_count = 0;
1141
1142         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1143         fm_pos += sizeof(*fmpl);
1144         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1145         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1146         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1147
1148         for (i = 0; i < ubi->fm_pool.size; i++) {
1149                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1150                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1151         }
1152
1153         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1154         fm_pos += sizeof(*fmpl_wl);
1155         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1156         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1157         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1158
1159         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1160                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1161                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1162         }
1163
1164         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1165                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1166
1167                 fec->pnum = cpu_to_be32(wl_e->pnum);
1168                 set_seen(ubi, wl_e->pnum, seen_pebs);
1169                 fec->ec = cpu_to_be32(wl_e->ec);
1170
1171                 free_peb_count++;
1172                 fm_pos += sizeof(*fec);
1173                 ubi_assert(fm_pos <= ubi->fm_size);
1174         }
1175         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1176
1177         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1178                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1179
1180                 fec->pnum = cpu_to_be32(wl_e->pnum);
1181                 set_seen(ubi, wl_e->pnum, seen_pebs);
1182                 fec->ec = cpu_to_be32(wl_e->ec);
1183
1184                 used_peb_count++;
1185                 fm_pos += sizeof(*fec);
1186                 ubi_assert(fm_pos <= ubi->fm_size);
1187         }
1188
1189         ubi_for_each_protected_peb(ubi, i, wl_e) {
1190                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1191
1192                 fec->pnum = cpu_to_be32(wl_e->pnum);
1193                 set_seen(ubi, wl_e->pnum, seen_pebs);
1194                 fec->ec = cpu_to_be32(wl_e->ec);
1195
1196                 used_peb_count++;
1197                 fm_pos += sizeof(*fec);
1198                 ubi_assert(fm_pos <= ubi->fm_size);
1199         }
1200         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1201
1202         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1203                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1204
1205                 fec->pnum = cpu_to_be32(wl_e->pnum);
1206                 set_seen(ubi, wl_e->pnum, seen_pebs);
1207                 fec->ec = cpu_to_be32(wl_e->ec);
1208
1209                 scrub_peb_count++;
1210                 fm_pos += sizeof(*fec);
1211                 ubi_assert(fm_pos <= ubi->fm_size);
1212         }
1213         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1214
1215
1216         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1217                 if (ubi_is_erase_work(ubi_wrk)) {
1218                         wl_e = ubi_wrk->e;
1219                         ubi_assert(wl_e);
1220
1221                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1222
1223                         fec->pnum = cpu_to_be32(wl_e->pnum);
1224                         set_seen(ubi, wl_e->pnum, seen_pebs);
1225                         fec->ec = cpu_to_be32(wl_e->ec);
1226
1227                         erase_peb_count++;
1228                         fm_pos += sizeof(*fec);
1229                         ubi_assert(fm_pos <= ubi->fm_size);
1230                 }
1231         }
1232         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1233
1234         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1235                 vol = ubi->volumes[i];
1236
1237                 if (!vol)
1238                         continue;
1239
1240                 vol_count++;
1241
1242                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1243                 fm_pos += sizeof(*fvh);
1244                 ubi_assert(fm_pos <= ubi->fm_size);
1245
1246                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1247                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1248                 fvh->vol_type = vol->vol_type;
1249                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1250                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1251                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1252
1253                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1254                         vol->vol_type == UBI_STATIC_VOLUME);
1255
1256                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1257                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1258                 ubi_assert(fm_pos <= ubi->fm_size);
1259
1260                 for (j = 0; j < vol->reserved_pebs; j++) {
1261                         struct ubi_eba_leb_desc ldesc;
1262
1263                         ubi_eba_get_ldesc(vol, j, &ldesc);
1264                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1265                 }
1266
1267                 feba->reserved_pebs = cpu_to_be32(j);
1268                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1269         }
1270         fmh->vol_count = cpu_to_be32(vol_count);
1271         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1272
1273         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1274         avhdr->lnum = 0;
1275
1276         spin_unlock(&ubi->wl_lock);
1277         spin_unlock(&ubi->volumes_lock);
1278
1279         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1280         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1281         if (ret) {
1282                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1283                 goto out_kfree;
1284         }
1285
1286         for (i = 0; i < new_fm->used_blocks; i++) {
1287                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1288                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1289                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1290         }
1291
1292         fmsb->data_crc = 0;
1293         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1294                                            ubi->fm_size));
1295
1296         for (i = 1; i < new_fm->used_blocks; i++) {
1297                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1298                 dvhdr->lnum = cpu_to_be32(i);
1299                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1300                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1301                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1302                 if (ret) {
1303                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1304                                 new_fm->e[i]->pnum);
1305                         goto out_kfree;
1306                 }
1307         }
1308
1309         for (i = 0; i < new_fm->used_blocks; i++) {
1310                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1311                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1312                 if (ret) {
1313                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1314                                 new_fm->e[i]->pnum);
1315                         goto out_kfree;
1316                 }
1317         }
1318
1319         ubi_assert(new_fm);
1320         ubi->fm = new_fm;
1321
1322         ret = self_check_seen(ubi, seen_pebs);
1323         dbg_bld("fastmap written!");
1324
1325 out_kfree:
1326         ubi_free_vid_hdr(ubi, avhdr);
1327         ubi_free_vid_hdr(ubi, dvhdr);
1328         free_seen(seen_pebs);
1329 out:
1330         return ret;
1331 }
1332
1333 /**
1334  * erase_block - Manually erase a PEB.
1335  * @ubi: UBI device object
1336  * @pnum: PEB to be erased
1337  *
1338  * Returns the new EC value on success, < 0 indicates an internal error.
1339  */
1340 static int erase_block(struct ubi_device *ubi, int pnum)
1341 {
1342         int ret;
1343         struct ubi_ec_hdr *ec_hdr;
1344         long long ec;
1345
1346         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1347         if (!ec_hdr)
1348                 return -ENOMEM;
1349
1350         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1351         if (ret < 0)
1352                 goto out;
1353         else if (ret && ret != UBI_IO_BITFLIPS) {
1354                 ret = -EINVAL;
1355                 goto out;
1356         }
1357
1358         ret = ubi_io_sync_erase(ubi, pnum, 0);
1359         if (ret < 0)
1360                 goto out;
1361
1362         ec = be64_to_cpu(ec_hdr->ec);
1363         ec += ret;
1364         if (ec > UBI_MAX_ERASECOUNTER) {
1365                 ret = -EINVAL;
1366                 goto out;
1367         }
1368
1369         ec_hdr->ec = cpu_to_be64(ec);
1370         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1371         if (ret < 0)
1372                 goto out;
1373
1374         ret = ec;
1375 out:
1376         kfree(ec_hdr);
1377         return ret;
1378 }
1379
1380 /**
1381  * invalidate_fastmap - destroys a fastmap.
1382  * @ubi: UBI device object
1383  *
1384  * This function ensures that upon next UBI attach a full scan
1385  * is issued. We need this if UBI is about to write a new fastmap
1386  * but is unable to do so. In this case we have two options:
1387  * a) Make sure that the current fastmap will not be usued upon
1388  * attach time and contine or b) fall back to RO mode to have the
1389  * current fastmap in a valid state.
1390  * Returns 0 on success, < 0 indicates an internal error.
1391  */
1392 static int invalidate_fastmap(struct ubi_device *ubi)
1393 {
1394         int ret;
1395         struct ubi_fastmap_layout *fm;
1396         struct ubi_wl_entry *e;
1397         struct ubi_vid_hdr *vh = NULL;
1398
1399         if (!ubi->fm)
1400                 return 0;
1401
1402         ubi->fm = NULL;
1403
1404         ret = -ENOMEM;
1405         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1406         if (!fm)
1407                 goto out;
1408
1409         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1410         if (!vh)
1411                 goto out_free_fm;
1412
1413         ret = -ENOSPC;
1414         e = ubi_wl_get_fm_peb(ubi, 1);
1415         if (!e)
1416                 goto out_free_fm;
1417
1418         /*
1419          * Create fake fastmap such that UBI will fall back
1420          * to scanning mode.
1421          */
1422         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1423         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1424         if (ret < 0) {
1425                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1426                 goto out_free_fm;
1427         }
1428
1429         fm->used_blocks = 1;
1430         fm->e[0] = e;
1431
1432         ubi->fm = fm;
1433
1434 out:
1435         ubi_free_vid_hdr(ubi, vh);
1436         return ret;
1437
1438 out_free_fm:
1439         kfree(fm);
1440         goto out;
1441 }
1442
1443 /**
1444  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1445  * WL sub-system.
1446  * @ubi: UBI device object
1447  * @fm: fastmap layout object
1448  */
1449 static void return_fm_pebs(struct ubi_device *ubi,
1450                            struct ubi_fastmap_layout *fm)
1451 {
1452         int i;
1453
1454         if (!fm)
1455                 return;
1456
1457         for (i = 0; i < fm->used_blocks; i++) {
1458                 if (fm->e[i]) {
1459                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1460                                           fm->to_be_tortured[i]);
1461                         fm->e[i] = NULL;
1462                 }
1463         }
1464 }
1465
1466 /**
1467  * ubi_update_fastmap - will be called by UBI if a volume changes or
1468  * a fastmap pool becomes full.
1469  * @ubi: UBI device object
1470  *
1471  * Returns 0 on success, < 0 indicates an internal error.
1472  */
1473 int ubi_update_fastmap(struct ubi_device *ubi)
1474 {
1475         int ret, i, j;
1476         struct ubi_fastmap_layout *new_fm, *old_fm;
1477         struct ubi_wl_entry *tmp_e;
1478
1479         down_write(&ubi->fm_protect);
1480
1481         ubi_refill_pools(ubi);
1482
1483         if (ubi->ro_mode || ubi->fm_disabled) {
1484                 up_write(&ubi->fm_protect);
1485                 return 0;
1486         }
1487
1488         ret = ubi_ensure_anchor_pebs(ubi);
1489         if (ret) {
1490                 up_write(&ubi->fm_protect);
1491                 return ret;
1492         }
1493
1494         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1495         if (!new_fm) {
1496                 up_write(&ubi->fm_protect);
1497                 return -ENOMEM;
1498         }
1499
1500         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1501         old_fm = ubi->fm;
1502         ubi->fm = NULL;
1503
1504         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1505                 ubi_err(ubi, "fastmap too large");
1506                 ret = -ENOSPC;
1507                 goto err;
1508         }
1509
1510         for (i = 1; i < new_fm->used_blocks; i++) {
1511                 spin_lock(&ubi->wl_lock);
1512                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1513                 spin_unlock(&ubi->wl_lock);
1514
1515                 if (!tmp_e) {
1516                         if (old_fm && old_fm->e[i]) {
1517                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1518                                 if (ret < 0) {
1519                                         ubi_err(ubi, "could not erase old fastmap PEB");
1520
1521                                         for (j = 1; j < i; j++) {
1522                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1523                                                                   j, 0);
1524                                                 new_fm->e[j] = NULL;
1525                                         }
1526                                         goto err;
1527                                 }
1528                                 new_fm->e[i] = old_fm->e[i];
1529                                 old_fm->e[i] = NULL;
1530                         } else {
1531                                 ubi_err(ubi, "could not get any free erase block");
1532
1533                                 for (j = 1; j < i; j++) {
1534                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1535                                         new_fm->e[j] = NULL;
1536                                 }
1537
1538                                 ret = -ENOSPC;
1539                                 goto err;
1540                         }
1541                 } else {
1542                         new_fm->e[i] = tmp_e;
1543
1544                         if (old_fm && old_fm->e[i]) {
1545                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1546                                                   old_fm->to_be_tortured[i]);
1547                                 old_fm->e[i] = NULL;
1548                         }
1549                 }
1550         }
1551
1552         /* Old fastmap is larger than the new one */
1553         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1554                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1555                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1556                                           old_fm->to_be_tortured[i]);
1557                         old_fm->e[i] = NULL;
1558                 }
1559         }
1560
1561         spin_lock(&ubi->wl_lock);
1562         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1563         spin_unlock(&ubi->wl_lock);
1564
1565         if (old_fm) {
1566                 /* no fresh anchor PEB was found, reuse the old one */
1567                 if (!tmp_e) {
1568                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1569                         if (ret < 0) {
1570                                 ubi_err(ubi, "could not erase old anchor PEB");
1571
1572                                 for (i = 1; i < new_fm->used_blocks; i++) {
1573                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1574                                                           i, 0);
1575                                         new_fm->e[i] = NULL;
1576                                 }
1577                                 goto err;
1578                         }
1579                         new_fm->e[0] = old_fm->e[0];
1580                         new_fm->e[0]->ec = ret;
1581                         old_fm->e[0] = NULL;
1582                 } else {
1583                         /* we've got a new anchor PEB, return the old one */
1584                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1585                                           old_fm->to_be_tortured[0]);
1586                         new_fm->e[0] = tmp_e;
1587                         old_fm->e[0] = NULL;
1588                 }
1589         } else {
1590                 if (!tmp_e) {
1591                         ubi_err(ubi, "could not find any anchor PEB");
1592
1593                         for (i = 1; i < new_fm->used_blocks; i++) {
1594                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1595                                 new_fm->e[i] = NULL;
1596                         }
1597
1598                         ret = -ENOSPC;
1599                         goto err;
1600                 }
1601                 new_fm->e[0] = tmp_e;
1602         }
1603
1604         down_write(&ubi->work_sem);
1605         down_write(&ubi->fm_eba_sem);
1606         ret = ubi_write_fastmap(ubi, new_fm);
1607         up_write(&ubi->fm_eba_sem);
1608         up_write(&ubi->work_sem);
1609
1610         if (ret)
1611                 goto err;
1612
1613 out_unlock:
1614         up_write(&ubi->fm_protect);
1615         kfree(old_fm);
1616         return ret;
1617
1618 err:
1619         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1620
1621         ret = invalidate_fastmap(ubi);
1622         if (ret < 0) {
1623                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1624                 ubi_ro_mode(ubi);
1625         } else {
1626                 return_fm_pebs(ubi, old_fm);
1627                 return_fm_pebs(ubi, new_fm);
1628                 ret = 0;
1629         }
1630
1631         kfree(new_fm);
1632         goto out_unlock;
1633 }