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 = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
 149         if (!aeb)
 150                 return -ENOMEM;
 151
 152         aeb->pnum = pnum;
 153         aeb->ec = ec;
 154         aeb->lnum = -1;
 155         aeb->scrub = scrub;
 156         aeb->copy_flag = aeb->sqnum = 0;
 157
 158         ai->ec_sum += aeb->ec;
 159         ai->ec_count++;
 160
 161         if (ai->max_ec < aeb->ec)
 162                 ai->max_ec = aeb->ec;
 163
 164         if (ai->min_ec > aeb->ec)
 165                 ai->min_ec = aeb->ec;
 166
 167         list_add_tail(&aeb->u.list, list);
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * add_vol - create and add a new volume to ubi_attach_info.
 174  * @ai: ubi_attach_info object
 175  * @vol_id: VID of the new volume
 176  * @used_ebs: number of used EBS
 177  * @data_pad: data padding value of the new volume
 178  * @vol_type: volume type
 179  * @last_eb_bytes: number of bytes in the last LEB
 180  *
 181  * Returns the new struct ubi_ainf_volume on success.
 182  * NULL indicates an error.
 183  */
 184 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 185                                        int used_ebs, int data_pad, u8 vol_type,
 186                                        int last_eb_bytes)
 187 {
 188         struct ubi_ainf_volume *av;
 189
 190         av = ubi_add_av(ai, vol_id);
 191         if (IS_ERR(av))
 192                 return av;
 193
 194         av->data_pad = data_pad;
 195         av->last_data_size = last_eb_bytes;
 196         av->compat = 0;
 197         av->vol_type = vol_type;
 198         if (av->vol_type == UBI_STATIC_VOLUME)
 199                 av->used_ebs = used_ebs;
 200
 201         dbg_bld("found volume (ID %i)", vol_id);
 202         return av;
 203 }
 204
 205 /**
 206  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 207  * from it's original list.
 208  * @ai: ubi_attach_info object
 209  * @aeb: the to be assigned SEB
 210  * @av: target scan volume
 211  */
 212 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 213                              struct ubi_ainf_peb *aeb,
 214                              struct ubi_ainf_volume *av)
 215 {
 216         struct ubi_ainf_peb *tmp_aeb;
 217         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 218
 219         p = &av->root.rb_node;
 220         while (*p) {
 221                 parent = *p;
 222
 223                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 224                 if (aeb->lnum != tmp_aeb->lnum) {
 225                         if (aeb->lnum < tmp_aeb->lnum)
 226                                 p = &(*p)->rb_left;
 227                         else
 228                                 p = &(*p)->rb_right;
 229
 230                         continue;
 231                 } else
 232                         break;
 233         }
 234
 235         list_del(&aeb->u.list);
 236         av->leb_count++;
 237
 238         rb_link_node(&aeb->u.rb, parent, p);
 239         rb_insert_color(&aeb->u.rb, &av->root);
 240 }
 241
 242 /**
 243  * update_vol - inserts or updates a LEB which was found a pool.
 244  * @ubi: the UBI device object
 245  * @ai: attach info object
 246  * @av: the volume this LEB belongs to
 247  * @new_vh: the volume header derived from new_aeb
 248  * @new_aeb: the AEB to be examined
 249  *
 250  * Returns 0 on success, < 0 indicates an internal error.
 251  */
 252 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 253                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 254                       struct ubi_ainf_peb *new_aeb)
 255 {
 256         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 257         struct ubi_ainf_peb *aeb, *victim;
 258         int cmp_res;
 259
 260         while (*p) {
 261                 parent = *p;
 262                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 263
 264                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 265                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 266                                 p = &(*p)->rb_left;
 267                         else
 268                                 p = &(*p)->rb_right;
 269
 270                         continue;
 271                 }
 272
 273                 /* This case can happen if the fastmap gets written
 274                  * because of a volume change (creation, deletion, ..).
 275                  * Then a PEB can be within the persistent EBA and the pool.
 276                  */
 277                 if (aeb->pnum == new_aeb->pnum) {
 278                         ubi_assert(aeb->lnum == new_aeb->lnum);
 279                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 280
 281                         return 0;
 282                 }
 283
 284                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 285                 if (cmp_res < 0)
 286                         return cmp_res;
 287
 288                 /* new_aeb is newer */
 289                 if (cmp_res & 1) {
 290                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 291                                 GFP_KERNEL);
 292                         if (!victim)
 293                                 return -ENOMEM;
 294
 295                         victim->ec = aeb->ec;
 296                         victim->pnum = aeb->pnum;
 297                         list_add_tail(&victim->u.list, &ai->erase);
 298
 299                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 300                                 av->last_data_size =
 301                                         be32_to_cpu(new_vh->data_size);
 302
 303                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 304                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 305
 306                         aeb->ec = new_aeb->ec;
 307                         aeb->pnum = new_aeb->pnum;
 308                         aeb->copy_flag = new_vh->copy_flag;
 309                         aeb->scrub = new_aeb->scrub;
 310                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 311
 312                 /* new_aeb is older */
 313                 } else {
 314                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 315                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 316                         list_add_tail(&new_aeb->u.list, &ai->erase);
 317                 }
 318
 319                 return 0;
 320         }
 321         /* This LEB is new, let's add it to the volume */
 322
 323         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 324                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 325                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 326         }
 327
 328         if (av->vol_type == UBI_STATIC_VOLUME)
 329                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 330
 331         av->leb_count++;
 332
 333         rb_link_node(&new_aeb->u.rb, parent, p);
 334         rb_insert_color(&new_aeb->u.rb, &av->root);
 335
 336         return 0;
 337 }
 338
 339 /**
 340  * process_pool_aeb - we found a non-empty PEB in a pool.
 341  * @ubi: UBI device object
 342  * @ai: attach info object
 343  * @new_vh: the volume header derived from new_aeb
 344  * @new_aeb: the AEB to be examined
 345  *
 346  * Returns 0 on success, < 0 indicates an internal error.
 347  */
 348 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 349                             struct ubi_vid_hdr *new_vh,
 350                             struct ubi_ainf_peb *new_aeb)
 351 {
 352         int vol_id = be32_to_cpu(new_vh->vol_id);
 353         struct ubi_ainf_volume *av;
 354
 355         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 356                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 357
 358                 return 0;
 359         }
 360
 361         /* Find the volume this SEB belongs to */
 362         av = ubi_find_av(ai, vol_id);
 363         if (!av) {
 364                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 365                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 366                 return UBI_BAD_FASTMAP;
 367         }
 368
 369         ubi_assert(vol_id == av->vol_id);
 370
 371         return update_vol(ubi, ai, av, new_vh, new_aeb);
 372 }
 373
 374 /**
 375  * unmap_peb - unmap a PEB.
 376  * If fastmap detects a free PEB in the pool it has to check whether
 377  * this PEB has been unmapped after writing the fastmap.
 378  *
 379  * @ai: UBI attach info object
 380  * @pnum: The PEB to be unmapped
 381  */
 382 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 383 {
 384         struct ubi_ainf_volume *av;
 385         struct rb_node *node, *node2;
 386         struct ubi_ainf_peb *aeb;
 387
 388         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 389                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 390                         if (aeb->pnum == pnum) {
 391                                 rb_erase(&aeb->u.rb, &av->root);
 392                                 av->leb_count--;
 393                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 394                                 return;
 395                         }
 396                 }
 397         }
 398 }
 399
 400 /**
 401  * scan_pool - scans a pool for changed (no longer empty PEBs).
 402  * @ubi: UBI device object
 403  * @ai: attach info object
 404  * @pebs: an array of all PEB numbers in the to be scanned pool
 405  * @pool_size: size of the pool (number of entries in @pebs)
 406  * @max_sqnum: pointer to the maximal sequence number
 407  * @free: list of PEBs which are most likely free (and go into @ai->free)
 408  *
 409  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 410  * < 0 indicates an internal error.
 411  */
 412 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 413                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 414                      struct list_head *free)
 415 {
 416         struct ubi_vid_hdr *vh;
 417         struct ubi_ec_hdr *ech;
 418         struct ubi_ainf_peb *new_aeb;
 419         int i, pnum, err, ret = 0;
 420
 421         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 422         if (!ech)
 423                 return -ENOMEM;
 424
 425         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 426         if (!vh) {
 427                 kfree(ech);
 428                 return -ENOMEM;
 429         }
 430
 431         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 432
 433         /*
 434          * Now scan all PEBs in the pool to find changes which have been made
 435          * after the creation of the fastmap
 436          */
 437         for (i = 0; i < pool_size; i++) {
 438                 int scrub = 0;
 439                 int image_seq;
 440
 441                 pnum = be32_to_cpu(pebs[i]);
 442
 443                 if (ubi_io_is_bad(ubi, pnum)) {
 444                         ubi_err(ubi, "bad PEB in fastmap pool!");
 445                         ret = UBI_BAD_FASTMAP;
 446                         goto out;
 447                 }
 448
 449                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 450                 if (err && err != UBI_IO_BITFLIPS) {
 451                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 452                                 pnum, err);
 453                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 454                         goto out;
 455                 } else if (err == UBI_IO_BITFLIPS)
 456                         scrub = 1;
 457
 458                 /*
 459                  * Older UBI implementations have image_seq set to zero, so
 460                  * we shouldn't fail if image_seq == 0.
 461                  */
 462                 image_seq = be32_to_cpu(ech->image_seq);
 463
 464                 if (image_seq && (image_seq != ubi->image_seq)) {
 465                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 466                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 467                         ret = UBI_BAD_FASTMAP;
 468                         goto out;
 469                 }
 470
 471                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 472                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 473                         unsigned long long ec = be64_to_cpu(ech->ec);
 474                         unmap_peb(ai, pnum);
 475                         dbg_bld("Adding PEB to free: %i", pnum);
 476
 477                         if (err == UBI_IO_FF_BITFLIPS)
 478                                 scrub = 1;
 479
 480                         add_aeb(ai, free, pnum, ec, scrub);
 481                         continue;
 482                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 483                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 484
 485                         if (err == UBI_IO_BITFLIPS)
 486                                 scrub = 1;
 487
 488                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 489                                                    GFP_KERNEL);
 490                         if (!new_aeb) {
 491                                 ret = -ENOMEM;
 492                                 goto out;
 493                         }
 494
 495                         new_aeb->ec = be64_to_cpu(ech->ec);
 496                         new_aeb->pnum = pnum;
 497                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 498                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 499                         new_aeb->copy_flag = vh->copy_flag;
 500                         new_aeb->scrub = scrub;
 501
 502                         if (*max_sqnum < new_aeb->sqnum)
 503                                 *max_sqnum = new_aeb->sqnum;
 504
 505                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 506                         if (err) {
 507                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 508                                 goto out;
 509                         }
 510                 } else {
 511                         /* We are paranoid and fall back to scanning mode */
 512                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 513                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 514                         goto out;
 515                 }
 516
 517         }
 518
 519 out:
 520         ubi_free_vid_hdr(ubi, vh);
 521         kfree(ech);
 522         return ret;
 523 }
 524
 525 /**
 526  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 527  * @ai: The UBI attach info object
 528  */
 529 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 530 {
 531         struct ubi_ainf_peb *aeb;
 532         struct ubi_ainf_volume *av;
 533         struct rb_node *rb1, *rb2;
 534         int n = 0;
 535
 536         list_for_each_entry(aeb, &ai->erase, u.list)
 537                 n++;
 538
 539         list_for_each_entry(aeb, &ai->free, u.list)
 540                 n++;
 541
 542         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 543                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 544                         n++;
 545
 546         return n;
 547 }
 548
 549 /**
 550  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 551  * @ubi: UBI device object
 552  * @ai: UBI attach info object
 553  * @fm: the fastmap to be attached
 554  *
 555  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 556  * < 0 indicates an internal error.
 557  */
 558 static int ubi_attach_fastmap(struct ubi_device *ubi,
 559                               struct ubi_attach_info *ai,
 560                               struct ubi_fastmap_layout *fm)
 561 {
 562         struct list_head used, free;
 563         struct ubi_ainf_volume *av;
 564         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 565         struct ubi_fm_sb *fmsb;
 566         struct ubi_fm_hdr *fmhdr;
 567         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 568         struct ubi_fm_ec *fmec;
 569         struct ubi_fm_volhdr *fmvhdr;
 570         struct ubi_fm_eba *fm_eba;
 571         int ret, i, j, pool_size, wl_pool_size;
 572         size_t fm_pos = 0, fm_size = ubi->fm_size;
 573         unsigned long long max_sqnum = 0;
 574         void *fm_raw = ubi->fm_buf;
 575
 576         INIT_LIST_HEAD(&used);
 577         INIT_LIST_HEAD(&free);
 578         ai->min_ec = UBI_MAX_ERASECOUNTER;
 579
 580         fmsb = (struct ubi_fm_sb *)(fm_raw);
 581         ai->max_sqnum = fmsb->sqnum;
 582         fm_pos += sizeof(struct ubi_fm_sb);
 583         if (fm_pos >= fm_size)
 584                 goto fail_bad;
 585
 586         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 587         fm_pos += sizeof(*fmhdr);
 588         if (fm_pos >= fm_size)
 589                 goto fail_bad;
 590
 591         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 592                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 593                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 594                 goto fail_bad;
 595         }
 596
 597         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 598         fm_pos += sizeof(*fmpl);
 599         if (fm_pos >= fm_size)
 600                 goto fail_bad;
 601         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 602                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 603                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 604                 goto fail_bad;
 605         }
 606
 607         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 608         fm_pos += sizeof(*fmpl_wl);
 609         if (fm_pos >= fm_size)
 610                 goto fail_bad;
 611         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 612                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 613                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 614                 goto fail_bad;
 615         }
 616
 617         pool_size = be16_to_cpu(fmpl->size);
 618         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 619         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 620         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 621
 622         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 623                 ubi_err(ubi, "bad pool size: %i", pool_size);
 624                 goto fail_bad;
 625         }
 626
 627         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 628                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 629                 goto fail_bad;
 630         }
 631
 632
 633         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 634             fm->max_pool_size < 0) {
 635                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 636                 goto fail_bad;
 637         }
 638
 639         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 640             fm->max_wl_pool_size < 0) {
 641                 ubi_err(ubi, "bad maximal WL pool size: %i",
 642                         fm->max_wl_pool_size);
 643                 goto fail_bad;
 644         }
 645
 646         /* read EC values from free list */
 647         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 648                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 649                 fm_pos += sizeof(*fmec);
 650                 if (fm_pos >= fm_size)
 651                         goto fail_bad;
 652
 653                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 654                         be32_to_cpu(fmec->ec), 0);
 655         }
 656
 657         /* read EC values from used list */
 658         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 659                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 660                 fm_pos += sizeof(*fmec);
 661                 if (fm_pos >= fm_size)
 662                         goto fail_bad;
 663
 664                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 665                         be32_to_cpu(fmec->ec), 0);
 666         }
 667
 668         /* read EC values from scrub list */
 669         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 670                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 671                 fm_pos += sizeof(*fmec);
 672                 if (fm_pos >= fm_size)
 673                         goto fail_bad;
 674
 675                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 676                         be32_to_cpu(fmec->ec), 1);
 677         }
 678
 679         /* read EC values from erase list */
 680         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 681                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 682                 fm_pos += sizeof(*fmec);
 683                 if (fm_pos >= fm_size)
 684                         goto fail_bad;
 685
 686                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 687                         be32_to_cpu(fmec->ec), 1);
 688         }
 689
 690         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 691         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 692
 693         /* Iterate over all volumes and read their EBA table */
 694         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 695                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 696                 fm_pos += sizeof(*fmvhdr);
 697                 if (fm_pos >= fm_size)
 698                         goto fail_bad;
 699
 700                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 701                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 702                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 703                         goto fail_bad;
 704                 }
 705
 706                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 707                              be32_to_cpu(fmvhdr->used_ebs),
 708                              be32_to_cpu(fmvhdr->data_pad),
 709                              fmvhdr->vol_type,
 710                              be32_to_cpu(fmvhdr->last_eb_bytes));
 711
 712                 if (!av)
 713                         goto fail_bad;
 714                 if (PTR_ERR(av) == -EINVAL) {
 715                         ubi_err(ubi, "volume (ID %i) already exists",
 716                                 fmvhdr->vol_id);
 717                         goto fail_bad;
 718                 }
 719
 720                 ai->vols_found++;
 721                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 722                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 723
 724                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 725                 fm_pos += sizeof(*fm_eba);
 726                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 727                 if (fm_pos >= fm_size)
 728                         goto fail_bad;
 729
 730                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 731                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 732                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 733                         goto fail_bad;
 734                 }
 735
 736                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 737                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 738
 739                         if (pnum < 0)
 740                                 continue;
 741
 742                         aeb = NULL;
 743                         list_for_each_entry(tmp_aeb, &used, u.list) {
 744                                 if (tmp_aeb->pnum == pnum) {
 745                                         aeb = tmp_aeb;
 746                                         break;
 747                                 }
 748                         }
 749
 750                         if (!aeb) {
 751                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 752                                 goto fail_bad;
 753                         }
 754
 755                         aeb->lnum = j;
 756
 757                         if (av->highest_lnum <= aeb->lnum)
 758                                 av->highest_lnum = aeb->lnum;
 759
 760                         assign_aeb_to_av(ai, aeb, av);
 761
 762                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 763                                 aeb->pnum, aeb->lnum, av->vol_id);
 764                 }
 765         }
 766
 767         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 768         if (ret)
 769                 goto fail;
 770
 771         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 772         if (ret)
 773                 goto fail;
 774
 775         if (max_sqnum > ai->max_sqnum)
 776                 ai->max_sqnum = max_sqnum;
 777
 778         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 779                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 780
 781         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 782                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 783
 784         ubi_assert(list_empty(&free));
 785
 786         /*
 787          * If fastmap is leaking PEBs (must not happen), raise a
 788          * fat warning and fall back to scanning mode.
 789          * We do this here because in ubi_wl_init() it's too late
 790          * and we cannot fall back to scanning.
 791          */
 792         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 793                     ai->bad_peb_count - fm->used_blocks))
 794                 goto fail_bad;
 795
 796         return 0;
 797
 798 fail_bad:
 799         ret = UBI_BAD_FASTMAP;
 800 fail:
 801         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 802                 list_del(&tmp_aeb->u.list);
 803                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 804         }
 805         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 806                 list_del(&tmp_aeb->u.list);
 807                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 808         }
 809
 810         return ret;
 811 }
 812
 813 /**
 814  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 815  * @ai: UBI attach info to be filled
 816  */
 817 static int find_fm_anchor(struct ubi_attach_info *ai)
 818 {
 819         int ret = -1;
 820         struct ubi_ainf_peb *aeb;
 821         unsigned long long max_sqnum = 0;
 822
 823         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 824                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 825                         max_sqnum = aeb->sqnum;
 826                         ret = aeb->pnum;
 827                 }
 828         }
 829
 830         return ret;
 831 }
 832
 833 /**
 834  * ubi_scan_fastmap - scan the fastmap.
 835  * @ubi: UBI device object
 836  * @ai: UBI attach info to be filled
 837  * @scan_ai: UBI attach info from the first 64 PEBs,
 838  *           used to find the most recent Fastmap data structure
 839  *
 840  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 841  * UBI_BAD_FASTMAP if one was found but is not usable.
 842  * < 0 indicates an internal error.
 843  */
 844 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 845                      struct ubi_attach_info *scan_ai)
 846 {
 847         struct ubi_fm_sb *fmsb, *fmsb2;
 848         struct ubi_vid_hdr *vh;
 849         struct ubi_ec_hdr *ech;
 850         struct ubi_fastmap_layout *fm;
 851         struct ubi_ainf_peb *tmp_aeb, *aeb;
 852         int i, used_blocks, pnum, fm_anchor, ret = 0;
 853         size_t fm_size;
 854         __be32 crc, tmp_crc;
 855         unsigned long long sqnum = 0;
 856
 857         fm_anchor = find_fm_anchor(scan_ai);
 858         if (fm_anchor < 0)
 859                 return UBI_NO_FASTMAP;
 860
 861         /* Move all (possible) fastmap blocks into our new attach structure. */
 862         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 863                 list_move_tail(&aeb->u.list, &ai->fastmap);
 864
 865         down_write(&ubi->fm_protect);
 866         memset(ubi->fm_buf, 0, ubi->fm_size);
 867
 868         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 869         if (!fmsb) {
 870                 ret = -ENOMEM;
 871                 goto out;
 872         }
 873
 874         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 875         if (!fm) {
 876                 ret = -ENOMEM;
 877                 kfree(fmsb);
 878                 goto out;
 879         }
 880
 881         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 882         if (ret && ret != UBI_IO_BITFLIPS)
 883                 goto free_fm_sb;
 884         else if (ret == UBI_IO_BITFLIPS)
 885                 fm->to_be_tortured[0] = 1;
 886
 887         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 888                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 889                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 890                 ret = UBI_BAD_FASTMAP;
 891                 goto free_fm_sb;
 892         }
 893
 894         if (fmsb->version != UBI_FM_FMT_VERSION) {
 895                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 896                         fmsb->version, UBI_FM_FMT_VERSION);
 897                 ret = UBI_BAD_FASTMAP;
 898                 goto free_fm_sb;
 899         }
 900
 901         used_blocks = be32_to_cpu(fmsb->used_blocks);
 902         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 903                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 904                         used_blocks);
 905                 ret = UBI_BAD_FASTMAP;
 906                 goto free_fm_sb;
 907         }
 908
 909         fm_size = ubi->leb_size * used_blocks;
 910         if (fm_size != ubi->fm_size) {
 911                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 912                         fm_size, ubi->fm_size);
 913                 ret = UBI_BAD_FASTMAP;
 914                 goto free_fm_sb;
 915         }
 916
 917         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 918         if (!ech) {
 919                 ret = -ENOMEM;
 920                 goto free_fm_sb;
 921         }
 922
 923         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 924         if (!vh) {
 925                 ret = -ENOMEM;
 926                 goto free_hdr;
 927         }
 928
 929         for (i = 0; i < used_blocks; i++) {
 930                 int image_seq;
 931
 932                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 933
 934                 if (ubi_io_is_bad(ubi, pnum)) {
 935                         ret = UBI_BAD_FASTMAP;
 936                         goto free_hdr;
 937                 }
 938
 939                 if (i == 0 && pnum != fm_anchor) {
 940                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 941                                 pnum, fm_anchor);
 942                         ret = UBI_BAD_FASTMAP;
 943                         goto free_hdr;
 944                 }
 945
 946                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 947                 if (ret && ret != UBI_IO_BITFLIPS) {
 948                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 949                                 i, pnum);
 950                         if (ret > 0)
 951                                 ret = UBI_BAD_FASTMAP;
 952                         goto free_hdr;
 953                 } else if (ret == UBI_IO_BITFLIPS)
 954                         fm->to_be_tortured[i] = 1;
 955
 956                 image_seq = be32_to_cpu(ech->image_seq);
 957                 if (!ubi->image_seq)
 958                         ubi->image_seq = image_seq;
 959
 960                 /*
 961                  * Older UBI implementations have image_seq set to zero, so
 962                  * we shouldn't fail if image_seq == 0.
 963                  */
 964                 if (image_seq && (image_seq != ubi->image_seq)) {
 965                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 966                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 967                         ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 }
 970
 971                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 972                 if (ret && ret != UBI_IO_BITFLIPS) {
 973                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 974                                 i, pnum);
 975                         goto free_hdr;
 976                 }
 977
 978                 if (i == 0) {
 979                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 980                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 981                                         be32_to_cpu(vh->vol_id),
 982                                         UBI_FM_SB_VOLUME_ID);
 983                                 ret = UBI_BAD_FASTMAP;
 984                                 goto free_hdr;
 985                         }
 986                 } else {
 987                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 988                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 989                                         be32_to_cpu(vh->vol_id),
 990                                         UBI_FM_DATA_VOLUME_ID);
 991                                 ret = UBI_BAD_FASTMAP;
 992                                 goto free_hdr;
 993                         }
 994                 }
 995
 996                 if (sqnum < be64_to_cpu(vh->sqnum))
 997                         sqnum = be64_to_cpu(vh->sqnum);
 998
 999                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1000                                   ubi->leb_start, ubi->leb_size);
1001                 if (ret && ret != UBI_IO_BITFLIPS) {
1002                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1003                                 "err: %i)", i, pnum, ret);
1004                         goto free_hdr;
1005                 }
1006         }
1007
1008         kfree(fmsb);
1009         fmsb = NULL;
1010
1011         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1012         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1013         fmsb2->data_crc = 0;
1014         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1015         if (crc != tmp_crc) {
1016                 ubi_err(ubi, "fastmap data CRC is invalid");
1017                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1018                         tmp_crc, crc);
1019                 ret = UBI_BAD_FASTMAP;
1020                 goto free_hdr;
1021         }
1022
1023         fmsb2->sqnum = sqnum;
1024
1025         fm->used_blocks = used_blocks;
1026
1027         ret = ubi_attach_fastmap(ubi, ai, fm);
1028         if (ret) {
1029                 if (ret > 0)
1030                         ret = UBI_BAD_FASTMAP;
1031                 goto free_hdr;
1032         }
1033
1034         for (i = 0; i < used_blocks; i++) {
1035                 struct ubi_wl_entry *e;
1036
1037                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1038                 if (!e) {
1039                         while (i--)
1040                                 kfree(fm->e[i]);
1041
1042                         ret = -ENOMEM;
1043                         goto free_hdr;
1044                 }
1045
1046                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1047                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1048                 fm->e[i] = e;
1049         }
1050
1051         ubi->fm = fm;
1052         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1053         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1054         ubi_msg(ubi, "attached by fastmap");
1055         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1056         ubi_msg(ubi, "fastmap WL pool size: %d",
1057                 ubi->fm_wl_pool.max_size);
1058         ubi->fm_disabled = 0;
1059         ubi->fast_attach = 1;
1060
1061         ubi_free_vid_hdr(ubi, vh);
1062         kfree(ech);
1063 out:
1064         up_write(&ubi->fm_protect);
1065         if (ret == UBI_BAD_FASTMAP)
1066                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1067         return ret;
1068
1069 free_hdr:
1070         ubi_free_vid_hdr(ubi, vh);
1071         kfree(ech);
1072 free_fm_sb:
1073         kfree(fmsb);
1074         kfree(fm);
1075         goto out;
1076 }
1077
1078 /**
1079  * ubi_write_fastmap - writes a fastmap.
1080  * @ubi: UBI device object
1081  * @new_fm: the to be written fastmap
1082  *
1083  * Returns 0 on success, < 0 indicates an internal error.
1084  */
1085 static int ubi_write_fastmap(struct ubi_device *ubi,
1086                              struct ubi_fastmap_layout *new_fm)
1087 {
1088         size_t fm_pos = 0;
1089         void *fm_raw;
1090         struct ubi_fm_sb *fmsb;
1091         struct ubi_fm_hdr *fmh;
1092         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1093         struct ubi_fm_ec *fec;
1094         struct ubi_fm_volhdr *fvh;
1095         struct ubi_fm_eba *feba;
1096         struct ubi_wl_entry *wl_e;
1097         struct ubi_volume *vol;
1098         struct ubi_vid_hdr *avhdr, *dvhdr;
1099         struct ubi_work *ubi_wrk;
1100         struct rb_node *tmp_rb;
1101         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1102         int scrub_peb_count, erase_peb_count;
1103         unsigned long *seen_pebs = NULL;
1104
1105         fm_raw = ubi->fm_buf;
1106         memset(ubi->fm_buf, 0, ubi->fm_size);
1107
1108         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1109         if (!avhdr) {
1110                 ret = -ENOMEM;
1111                 goto out;
1112         }
1113
1114         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1115         if (!dvhdr) {
1116                 ret = -ENOMEM;
1117                 goto out_kfree;
1118         }
1119
1120         seen_pebs = init_seen(ubi);
1121         if (IS_ERR(seen_pebs)) {
1122                 ret = PTR_ERR(seen_pebs);
1123                 goto out_kfree;
1124         }
1125
1126         spin_lock(&ubi->volumes_lock);
1127         spin_lock(&ubi->wl_lock);
1128
1129         fmsb = (struct ubi_fm_sb *)fm_raw;
1130         fm_pos += sizeof(*fmsb);
1131         ubi_assert(fm_pos <= ubi->fm_size);
1132
1133         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1134         fm_pos += sizeof(*fmh);
1135         ubi_assert(fm_pos <= ubi->fm_size);
1136
1137         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1138         fmsb->version = UBI_FM_FMT_VERSION;
1139         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1140         /* the max sqnum will be filled in while *reading* the fastmap */
1141         fmsb->sqnum = 0;
1142
1143         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1144         free_peb_count = 0;
1145         used_peb_count = 0;
1146         scrub_peb_count = 0;
1147         erase_peb_count = 0;
1148         vol_count = 0;
1149
1150         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1151         fm_pos += sizeof(*fmpl);
1152         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1153         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1154         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1155
1156         for (i = 0; i < ubi->fm_pool.size; i++) {
1157                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1158                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1159         }
1160
1161         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1162         fm_pos += sizeof(*fmpl_wl);
1163         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1164         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1165         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1166
1167         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1168                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1169                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1170         }
1171
1172         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1173                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1174
1175                 fec->pnum = cpu_to_be32(wl_e->pnum);
1176                 set_seen(ubi, wl_e->pnum, seen_pebs);
1177                 fec->ec = cpu_to_be32(wl_e->ec);
1178
1179                 free_peb_count++;
1180                 fm_pos += sizeof(*fec);
1181                 ubi_assert(fm_pos <= ubi->fm_size);
1182         }
1183         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1184
1185         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1186                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1187
1188                 fec->pnum = cpu_to_be32(wl_e->pnum);
1189                 set_seen(ubi, wl_e->pnum, seen_pebs);
1190                 fec->ec = cpu_to_be32(wl_e->ec);
1191
1192                 used_peb_count++;
1193                 fm_pos += sizeof(*fec);
1194                 ubi_assert(fm_pos <= ubi->fm_size);
1195         }
1196
1197         ubi_for_each_protected_peb(ubi, i, wl_e) {
1198                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1199
1200                 fec->pnum = cpu_to_be32(wl_e->pnum);
1201                 set_seen(ubi, wl_e->pnum, seen_pebs);
1202                 fec->ec = cpu_to_be32(wl_e->ec);
1203
1204                 used_peb_count++;
1205                 fm_pos += sizeof(*fec);
1206                 ubi_assert(fm_pos <= ubi->fm_size);
1207         }
1208         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1209
1210         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1211                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1212
1213                 fec->pnum = cpu_to_be32(wl_e->pnum);
1214                 set_seen(ubi, wl_e->pnum, seen_pebs);
1215                 fec->ec = cpu_to_be32(wl_e->ec);
1216
1217                 scrub_peb_count++;
1218                 fm_pos += sizeof(*fec);
1219                 ubi_assert(fm_pos <= ubi->fm_size);
1220         }
1221         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1222
1223
1224         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1225                 if (ubi_is_erase_work(ubi_wrk)) {
1226                         wl_e = ubi_wrk->e;
1227                         ubi_assert(wl_e);
1228
1229                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1230
1231                         fec->pnum = cpu_to_be32(wl_e->pnum);
1232                         set_seen(ubi, wl_e->pnum, seen_pebs);
1233                         fec->ec = cpu_to_be32(wl_e->ec);
1234
1235                         erase_peb_count++;
1236                         fm_pos += sizeof(*fec);
1237                         ubi_assert(fm_pos <= ubi->fm_size);
1238                 }
1239         }
1240         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1241
1242         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1243                 vol = ubi->volumes[i];
1244
1245                 if (!vol)
1246                         continue;
1247
1248                 vol_count++;
1249
1250                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1251                 fm_pos += sizeof(*fvh);
1252                 ubi_assert(fm_pos <= ubi->fm_size);
1253
1254                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1255                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1256                 fvh->vol_type = vol->vol_type;
1257                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1258                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1259                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1260
1261                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1262                         vol->vol_type == UBI_STATIC_VOLUME);
1263
1264                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1265                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1266                 ubi_assert(fm_pos <= ubi->fm_size);
1267
1268                 for (j = 0; j < vol->reserved_pebs; j++)
1269                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1270
1271                 feba->reserved_pebs = cpu_to_be32(j);
1272                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1273         }
1274         fmh->vol_count = cpu_to_be32(vol_count);
1275         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1276
1277         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1278         avhdr->lnum = 0;
1279
1280         spin_unlock(&ubi->wl_lock);
1281         spin_unlock(&ubi->volumes_lock);
1282
1283         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1284         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1285         if (ret) {
1286                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1287                 goto out_kfree;
1288         }
1289
1290         for (i = 0; i < new_fm->used_blocks; i++) {
1291                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1292                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1293                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1294         }
1295
1296         fmsb->data_crc = 0;
1297         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1298                                            ubi->fm_size));
1299
1300         for (i = 1; i < new_fm->used_blocks; i++) {
1301                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1302                 dvhdr->lnum = cpu_to_be32(i);
1303                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1304                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1305                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1306                 if (ret) {
1307                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1308                                 new_fm->e[i]->pnum);
1309                         goto out_kfree;
1310                 }
1311         }
1312
1313         for (i = 0; i < new_fm->used_blocks; i++) {
1314                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1315                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1316                 if (ret) {
1317                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1318                                 new_fm->e[i]->pnum);
1319                         goto out_kfree;
1320                 }
1321         }
1322
1323         ubi_assert(new_fm);
1324         ubi->fm = new_fm;
1325
1326         ret = self_check_seen(ubi, seen_pebs);
1327         dbg_bld("fastmap written!");
1328
1329 out_kfree:
1330         ubi_free_vid_hdr(ubi, avhdr);
1331         ubi_free_vid_hdr(ubi, dvhdr);
1332         free_seen(seen_pebs);
1333 out:
1334         return ret;
1335 }
1336
1337 /**
1338  * erase_block - Manually erase a PEB.
1339  * @ubi: UBI device object
1340  * @pnum: PEB to be erased
1341  *
1342  * Returns the new EC value on success, < 0 indicates an internal error.
1343  */
1344 static int erase_block(struct ubi_device *ubi, int pnum)
1345 {
1346         int ret;
1347         struct ubi_ec_hdr *ec_hdr;
1348         long long ec;
1349
1350         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1351         if (!ec_hdr)
1352                 return -ENOMEM;
1353
1354         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1355         if (ret < 0)
1356                 goto out;
1357         else if (ret && ret != UBI_IO_BITFLIPS) {
1358                 ret = -EINVAL;
1359                 goto out;
1360         }
1361
1362         ret = ubi_io_sync_erase(ubi, pnum, 0);
1363         if (ret < 0)
1364                 goto out;
1365
1366         ec = be64_to_cpu(ec_hdr->ec);
1367         ec += ret;
1368         if (ec > UBI_MAX_ERASECOUNTER) {
1369                 ret = -EINVAL;
1370                 goto out;
1371         }
1372
1373         ec_hdr->ec = cpu_to_be64(ec);
1374         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1375         if (ret < 0)
1376                 goto out;
1377
1378         ret = ec;
1379 out:
1380         kfree(ec_hdr);
1381         return ret;
1382 }
1383
1384 /**
1385  * invalidate_fastmap - destroys a fastmap.
1386  * @ubi: UBI device object
1387  *
1388  * This function ensures that upon next UBI attach a full scan
1389  * is issued. We need this if UBI is about to write a new fastmap
1390  * but is unable to do so. In this case we have two options:
1391  * a) Make sure that the current fastmap will not be usued upon
1392  * attach time and contine or b) fall back to RO mode to have the
1393  * current fastmap in a valid state.
1394  * Returns 0 on success, < 0 indicates an internal error.
1395  */
1396 static int invalidate_fastmap(struct ubi_device *ubi)
1397 {
1398         int ret;
1399         struct ubi_fastmap_layout *fm;
1400         struct ubi_wl_entry *e;
1401         struct ubi_vid_hdr *vh = NULL;
1402
1403         if (!ubi->fm)
1404                 return 0;
1405
1406         ubi->fm = NULL;
1407
1408         ret = -ENOMEM;
1409         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1410         if (!fm)
1411                 goto out;
1412
1413         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1414         if (!vh)
1415                 goto out_free_fm;
1416
1417         ret = -ENOSPC;
1418         e = ubi_wl_get_fm_peb(ubi, 1);
1419         if (!e)
1420                 goto out_free_fm;
1421
1422         /*
1423          * Create fake fastmap such that UBI will fall back
1424          * to scanning mode.
1425          */
1426         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1427         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1428         if (ret < 0) {
1429                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1430                 goto out_free_fm;
1431         }
1432
1433         fm->used_blocks = 1;
1434         fm->e[0] = e;
1435
1436         ubi->fm = fm;
1437
1438 out:
1439         ubi_free_vid_hdr(ubi, vh);
1440         return ret;
1441
1442 out_free_fm:
1443         kfree(fm);
1444         goto out;
1445 }
1446
1447 /**
1448  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1449  * WL sub-system.
1450  * @ubi: UBI device object
1451  * @fm: fastmap layout object
1452  */
1453 static void return_fm_pebs(struct ubi_device *ubi,
1454                            struct ubi_fastmap_layout *fm)
1455 {
1456         int i;
1457
1458         if (!fm)
1459                 return;
1460
1461         for (i = 0; i < fm->used_blocks; i++) {
1462                 if (fm->e[i]) {
1463                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1464                                           fm->to_be_tortured[i]);
1465                         fm->e[i] = NULL;
1466                 }
1467         }
1468 }
1469
1470 /**
1471  * ubi_update_fastmap - will be called by UBI if a volume changes or
1472  * a fastmap pool becomes full.
1473  * @ubi: UBI device object
1474  *
1475  * Returns 0 on success, < 0 indicates an internal error.
1476  */
1477 int ubi_update_fastmap(struct ubi_device *ubi)
1478 {
1479         int ret, i, j;
1480         struct ubi_fastmap_layout *new_fm, *old_fm;
1481         struct ubi_wl_entry *tmp_e;
1482
1483         down_write(&ubi->fm_protect);
1484
1485         ubi_refill_pools(ubi);
1486
1487         if (ubi->ro_mode || ubi->fm_disabled) {
1488                 up_write(&ubi->fm_protect);
1489                 return 0;
1490         }
1491
1492         ret = ubi_ensure_anchor_pebs(ubi);
1493         if (ret) {
1494                 up_write(&ubi->fm_protect);
1495                 return ret;
1496         }
1497
1498         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1499         if (!new_fm) {
1500                 up_write(&ubi->fm_protect);
1501                 return -ENOMEM;
1502         }
1503
1504         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1505         old_fm = ubi->fm;
1506         ubi->fm = NULL;
1507
1508         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1509                 ubi_err(ubi, "fastmap too large");
1510                 ret = -ENOSPC;
1511                 goto err;
1512         }
1513
1514         for (i = 1; i < new_fm->used_blocks; i++) {
1515                 spin_lock(&ubi->wl_lock);
1516                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1517                 spin_unlock(&ubi->wl_lock);
1518
1519                 if (!tmp_e) {
1520                         if (old_fm && old_fm->e[i]) {
1521                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1522                                 if (ret < 0) {
1523                                         ubi_err(ubi, "could not erase old fastmap PEB");
1524
1525                                         for (j = 1; j < i; j++) {
1526                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1527                                                                   j, 0);
1528                                                 new_fm->e[j] = NULL;
1529                                         }
1530                                         goto err;
1531                                 }
1532                                 new_fm->e[i] = old_fm->e[i];
1533                                 old_fm->e[i] = NULL;
1534                         } else {
1535                                 ubi_err(ubi, "could not get any free erase block");
1536
1537                                 for (j = 1; j < i; j++) {
1538                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1539                                         new_fm->e[j] = NULL;
1540                                 }
1541
1542                                 ret = -ENOSPC;
1543                                 goto err;
1544                         }
1545                 } else {
1546                         new_fm->e[i] = tmp_e;
1547
1548                         if (old_fm && old_fm->e[i]) {
1549                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1550                                                   old_fm->to_be_tortured[i]);
1551                                 old_fm->e[i] = NULL;
1552                         }
1553                 }
1554         }
1555
1556         /* Old fastmap is larger than the new one */
1557         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1558                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1559                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1560                                           old_fm->to_be_tortured[i]);
1561                         old_fm->e[i] = NULL;
1562                 }
1563         }
1564
1565         spin_lock(&ubi->wl_lock);
1566         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1567         spin_unlock(&ubi->wl_lock);
1568
1569         if (old_fm) {
1570                 /* no fresh anchor PEB was found, reuse the old one */
1571                 if (!tmp_e) {
1572                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1573                         if (ret < 0) {
1574                                 ubi_err(ubi, "could not erase old anchor PEB");
1575
1576                                 for (i = 1; i < new_fm->used_blocks; i++) {
1577                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1578                                                           i, 0);
1579                                         new_fm->e[i] = NULL;
1580                                 }
1581                                 goto err;
1582                         }
1583                         new_fm->e[0] = old_fm->e[0];
1584                         new_fm->e[0]->ec = ret;
1585                         old_fm->e[0] = NULL;
1586                 } else {
1587                         /* we've got a new anchor PEB, return the old one */
1588                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1589                                           old_fm->to_be_tortured[0]);
1590                         new_fm->e[0] = tmp_e;
1591                         old_fm->e[0] = NULL;
1592                 }
1593         } else {
1594                 if (!tmp_e) {
1595                         ubi_err(ubi, "could not find any anchor PEB");
1596
1597                         for (i = 1; i < new_fm->used_blocks; i++) {
1598                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1599                                 new_fm->e[i] = NULL;
1600                         }
1601
1602                         ret = -ENOSPC;
1603                         goto err;
1604                 }
1605                 new_fm->e[0] = tmp_e;
1606         }
1607
1608         down_write(&ubi->work_sem);
1609         down_write(&ubi->fm_eba_sem);
1610         ret = ubi_write_fastmap(ubi, new_fm);
1611         up_write(&ubi->fm_eba_sem);
1612         up_write(&ubi->work_sem);
1613
1614         if (ret)
1615                 goto err;
1616
1617 out_unlock:
1618         up_write(&ubi->fm_protect);
1619         kfree(old_fm);
1620         return ret;
1621
1622 err:
1623         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1624
1625         ret = invalidate_fastmap(ubi);
1626         if (ret < 0) {
1627                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1628                 ubi_ro_mode(ubi);
1629         } else {
1630                 return_fm_pebs(ubi, old_fm);
1631                 return_fm_pebs(ubi, new_fm);
1632                 ret = 0;
1633         }
1634
1635         kfree(new_fm);
1636         goto out_unlock;
1637 }