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_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 114 {
 115         struct ubi_vid_io_buf *new;
 116         struct ubi_vid_hdr *vh;
 117
 118         new = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 119         if (!new)
 120                 goto out;
 121
 122         vh = ubi_get_vid_hdr(new);
 123         vh->vol_type = UBI_VID_DYNAMIC;
 124         vh->vol_id = cpu_to_be32(vol_id);
 125
 126         /* UBI implementations without fastmap support have to delete the
 127          * fastmap.
 128          */
 129         vh->compat = UBI_COMPAT_DELETE;
 130
 131 out:
 132         return new;
 133 }
 134
 135 /**
 136  * add_aeb - create and add a attach erase block to a given list.
 137  * @ai: UBI attach info object
 138  * @list: the target list
 139  * @pnum: PEB number of the new attach erase block
 140  * @ec: erease counter of the new LEB
 141  * @scrub: scrub this PEB after attaching
 142  *
 143  * Returns 0 on success, < 0 indicates an internal error.
 144  */
 145 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 146                    int pnum, int ec, int scrub)
 147 {
 148         struct ubi_ainf_peb *aeb;
 149
 150         aeb = ubi_alloc_aeb(ai, pnum, ec);
 151         if (!aeb)
 152                 return -ENOMEM;
 153
 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                         ubi_free_aeb(ai, 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 = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 291                         if (!victim)
 292                                 return -ENOMEM;
 293
 294                         list_add_tail(&victim->u.list, &ai->erase);
 295
 296                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 297                                 av->last_data_size =
 298                                         be32_to_cpu(new_vh->data_size);
 299
 300                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 301                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 302
 303                         aeb->ec = new_aeb->ec;
 304                         aeb->pnum = new_aeb->pnum;
 305                         aeb->copy_flag = new_vh->copy_flag;
 306                         aeb->scrub = new_aeb->scrub;
 307                         aeb->sqnum = new_aeb->sqnum;
 308                         ubi_free_aeb(ai, new_aeb);
 309
 310                 /* new_aeb is older */
 311                 } else {
 312                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 313                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 314                         list_add_tail(&new_aeb->u.list, &ai->erase);
 315                 }
 316
 317                 return 0;
 318         }
 319         /* This LEB is new, let's add it to the volume */
 320
 321         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 322                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 323                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 324         }
 325
 326         if (av->vol_type == UBI_STATIC_VOLUME)
 327                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 328
 329         av->leb_count++;
 330
 331         rb_link_node(&new_aeb->u.rb, parent, p);
 332         rb_insert_color(&new_aeb->u.rb, &av->root);
 333
 334         return 0;
 335 }
 336
 337 /**
 338  * process_pool_aeb - we found a non-empty PEB in a pool.
 339  * @ubi: UBI device object
 340  * @ai: attach info object
 341  * @new_vh: the volume header derived from new_aeb
 342  * @new_aeb: the AEB to be examined
 343  *
 344  * Returns 0 on success, < 0 indicates an internal error.
 345  */
 346 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 347                             struct ubi_vid_hdr *new_vh,
 348                             struct ubi_ainf_peb *new_aeb)
 349 {
 350         int vol_id = be32_to_cpu(new_vh->vol_id);
 351         struct ubi_ainf_volume *av;
 352
 353         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 354                 ubi_free_aeb(ai, new_aeb);
 355
 356                 return 0;
 357         }
 358
 359         /* Find the volume this SEB belongs to */
 360         av = ubi_find_av(ai, vol_id);
 361         if (!av) {
 362                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 363                 ubi_free_aeb(ai, new_aeb);
 364                 return UBI_BAD_FASTMAP;
 365         }
 366
 367         ubi_assert(vol_id == av->vol_id);
 368
 369         return update_vol(ubi, ai, av, new_vh, new_aeb);
 370 }
 371
 372 /**
 373  * unmap_peb - unmap a PEB.
 374  * If fastmap detects a free PEB in the pool it has to check whether
 375  * this PEB has been unmapped after writing the fastmap.
 376  *
 377  * @ai: UBI attach info object
 378  * @pnum: The PEB to be unmapped
 379  */
 380 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 381 {
 382         struct ubi_ainf_volume *av;
 383         struct rb_node *node, *node2;
 384         struct ubi_ainf_peb *aeb;
 385
 386         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 387                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 388                         if (aeb->pnum == pnum) {
 389                                 rb_erase(&aeb->u.rb, &av->root);
 390                                 av->leb_count--;
 391                                 ubi_free_aeb(ai, aeb);
 392                                 return;
 393                         }
 394                 }
 395         }
 396 }
 397
 398 /**
 399  * scan_pool - scans a pool for changed (no longer empty PEBs).
 400  * @ubi: UBI device object
 401  * @ai: attach info object
 402  * @pebs: an array of all PEB numbers in the to be scanned pool
 403  * @pool_size: size of the pool (number of entries in @pebs)
 404  * @max_sqnum: pointer to the maximal sequence number
 405  * @free: list of PEBs which are most likely free (and go into @ai->free)
 406  *
 407  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 408  * < 0 indicates an internal error.
 409  */
 410 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 411                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 412                      struct list_head *free)
 413 {
 414         struct ubi_vid_io_buf *vb;
 415         struct ubi_vid_hdr *vh;
 416         struct ubi_ec_hdr *ech;
 417         struct ubi_ainf_peb *new_aeb;
 418         int i, pnum, err, ret = 0;
 419
 420         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 421         if (!ech)
 422                 return -ENOMEM;
 423
 424         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 425         if (!vb) {
 426                 kfree(ech);
 427                 return -ENOMEM;
 428         }
 429
 430         vh = ubi_get_vid_hdr(vb);
 431
 432         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 433
 434         /*
 435          * Now scan all PEBs in the pool to find changes which have been made
 436          * after the creation of the fastmap
 437          */
 438         for (i = 0; i < pool_size; i++) {
 439                 int scrub = 0;
 440                 int image_seq;
 441
 442                 pnum = be32_to_cpu(pebs[i]);
 443
 444                 if (ubi_io_is_bad(ubi, pnum)) {
 445                         ubi_err(ubi, "bad PEB in fastmap pool!");
 446                         ret = UBI_BAD_FASTMAP;
 447                         goto out;
 448                 }
 449
 450                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 451                 if (err && err != UBI_IO_BITFLIPS) {
 452                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 453                                 pnum, err);
 454                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 455                         goto out;
 456                 } else if (err == UBI_IO_BITFLIPS)
 457                         scrub = 1;
 458
 459                 /*
 460                  * Older UBI implementations have image_seq set to zero, so
 461                  * we shouldn't fail if image_seq == 0.
 462                  */
 463                 image_seq = be32_to_cpu(ech->image_seq);
 464
 465                 if (image_seq && (image_seq != ubi->image_seq)) {
 466                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 467                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 468                         ret = UBI_BAD_FASTMAP;
 469                         goto out;
 470                 }
 471
 472                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 473                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 474                         unsigned long long ec = be64_to_cpu(ech->ec);
 475                         unmap_peb(ai, pnum);
 476                         dbg_bld("Adding PEB to free: %i", pnum);
 477
 478                         if (err == UBI_IO_FF_BITFLIPS)
 479                                 scrub = 1;
 480
 481                         add_aeb(ai, free, pnum, ec, scrub);
 482                         continue;
 483                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 484                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 485
 486                         if (err == UBI_IO_BITFLIPS)
 487                                 scrub = 1;
 488
 489                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 490                         if (!new_aeb) {
 491                                 ret = -ENOMEM;
 492                                 goto out;
 493                         }
 494
 495                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 496                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 497                         new_aeb->copy_flag = vh->copy_flag;
 498                         new_aeb->scrub = scrub;
 499
 500                         if (*max_sqnum < new_aeb->sqnum)
 501                                 *max_sqnum = new_aeb->sqnum;
 502
 503                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 504                         if (err) {
 505                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 506                                 goto out;
 507                         }
 508                 } else {
 509                         /* We are paranoid and fall back to scanning mode */
 510                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 511                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 512                         goto out;
 513                 }
 514
 515         }
 516
 517 out:
 518         ubi_free_vid_buf(vb);
 519         kfree(ech);
 520         return ret;
 521 }
 522
 523 /**
 524  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 525  * @ai: The UBI attach info object
 526  */
 527 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 528 {
 529         struct ubi_ainf_peb *aeb;
 530         struct ubi_ainf_volume *av;
 531         struct rb_node *rb1, *rb2;
 532         int n = 0;
 533
 534         list_for_each_entry(aeb, &ai->erase, u.list)
 535                 n++;
 536
 537         list_for_each_entry(aeb, &ai->free, u.list)
 538                 n++;
 539
 540         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 541                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 542                         n++;
 543
 544         return n;
 545 }
 546
 547 /**
 548  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 549  * @ubi: UBI device object
 550  * @ai: UBI attach info object
 551  * @fm: the fastmap to be attached
 552  *
 553  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 554  * < 0 indicates an internal error.
 555  */
 556 static int ubi_attach_fastmap(struct ubi_device *ubi,
 557                               struct ubi_attach_info *ai,
 558                               struct ubi_fastmap_layout *fm)
 559 {
 560         struct list_head used, free;
 561         struct ubi_ainf_volume *av;
 562         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 563         struct ubi_fm_sb *fmsb;
 564         struct ubi_fm_hdr *fmhdr;
 565         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 566         struct ubi_fm_ec *fmec;
 567         struct ubi_fm_volhdr *fmvhdr;
 568         struct ubi_fm_eba *fm_eba;
 569         int ret, i, j, pool_size, wl_pool_size;
 570         size_t fm_pos = 0, fm_size = ubi->fm_size;
 571         unsigned long long max_sqnum = 0;
 572         void *fm_raw = ubi->fm_buf;
 573
 574         INIT_LIST_HEAD(&used);
 575         INIT_LIST_HEAD(&free);
 576         ai->min_ec = UBI_MAX_ERASECOUNTER;
 577
 578         fmsb = (struct ubi_fm_sb *)(fm_raw);
 579         ai->max_sqnum = fmsb->sqnum;
 580         fm_pos += sizeof(struct ubi_fm_sb);
 581         if (fm_pos >= fm_size)
 582                 goto fail_bad;
 583
 584         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 585         fm_pos += sizeof(*fmhdr);
 586         if (fm_pos >= fm_size)
 587                 goto fail_bad;
 588
 589         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 590                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 591                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 592                 goto fail_bad;
 593         }
 594
 595         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 596         fm_pos += sizeof(*fmpl);
 597         if (fm_pos >= fm_size)
 598                 goto fail_bad;
 599         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 600                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 601                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 602                 goto fail_bad;
 603         }
 604
 605         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 606         fm_pos += sizeof(*fmpl_wl);
 607         if (fm_pos >= fm_size)
 608                 goto fail_bad;
 609         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 610                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 611                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 612                 goto fail_bad;
 613         }
 614
 615         pool_size = be16_to_cpu(fmpl->size);
 616         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 617         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 618         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 619
 620         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 621                 ubi_err(ubi, "bad pool size: %i", pool_size);
 622                 goto fail_bad;
 623         }
 624
 625         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 626                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 627                 goto fail_bad;
 628         }
 629
 630
 631         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 632             fm->max_pool_size < 0) {
 633                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 634                 goto fail_bad;
 635         }
 636
 637         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 638             fm->max_wl_pool_size < 0) {
 639                 ubi_err(ubi, "bad maximal WL pool size: %i",
 640                         fm->max_wl_pool_size);
 641                 goto fail_bad;
 642         }
 643
 644         /* read EC values from free list */
 645         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 646                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 647                 fm_pos += sizeof(*fmec);
 648                 if (fm_pos >= fm_size)
 649                         goto fail_bad;
 650
 651                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 652                         be32_to_cpu(fmec->ec), 0);
 653         }
 654
 655         /* read EC values from used list */
 656         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 657                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 658                 fm_pos += sizeof(*fmec);
 659                 if (fm_pos >= fm_size)
 660                         goto fail_bad;
 661
 662                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 663                         be32_to_cpu(fmec->ec), 0);
 664         }
 665
 666         /* read EC values from scrub list */
 667         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 668                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 669                 fm_pos += sizeof(*fmec);
 670                 if (fm_pos >= fm_size)
 671                         goto fail_bad;
 672
 673                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 674                         be32_to_cpu(fmec->ec), 1);
 675         }
 676
 677         /* read EC values from erase list */
 678         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 679                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 680                 fm_pos += sizeof(*fmec);
 681                 if (fm_pos >= fm_size)
 682                         goto fail_bad;
 683
 684                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 685                         be32_to_cpu(fmec->ec), 1);
 686         }
 687
 688         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 689         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 690
 691         /* Iterate over all volumes and read their EBA table */
 692         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 693                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 694                 fm_pos += sizeof(*fmvhdr);
 695                 if (fm_pos >= fm_size)
 696                         goto fail_bad;
 697
 698                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 699                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 700                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 701                         goto fail_bad;
 702                 }
 703
 704                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 705                              be32_to_cpu(fmvhdr->used_ebs),
 706                              be32_to_cpu(fmvhdr->data_pad),
 707                              fmvhdr->vol_type,
 708                              be32_to_cpu(fmvhdr->last_eb_bytes));
 709
 710                 if (IS_ERR(av)) {
 711                         if (PTR_ERR(av) == -EEXIST)
 712                                 ubi_err(ubi, "volume (ID %i) already exists",
 713                                         fmvhdr->vol_id);
 714
 715                         goto fail_bad;
 716                 }
 717
 718                 ai->vols_found++;
 719                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 720                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 721
 722                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 723                 fm_pos += sizeof(*fm_eba);
 724                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 725                 if (fm_pos >= fm_size)
 726                         goto fail_bad;
 727
 728                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 729                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 730                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 731                         goto fail_bad;
 732                 }
 733
 734                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 735                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 736
 737                         if (pnum < 0)
 738                                 continue;
 739
 740                         aeb = NULL;
 741                         list_for_each_entry(tmp_aeb, &used, u.list) {
 742                                 if (tmp_aeb->pnum == pnum) {
 743                                         aeb = tmp_aeb;
 744                                         break;
 745                                 }
 746                         }
 747
 748                         if (!aeb) {
 749                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 750                                 goto fail_bad;
 751                         }
 752
 753                         aeb->lnum = j;
 754
 755                         if (av->highest_lnum <= aeb->lnum)
 756                                 av->highest_lnum = aeb->lnum;
 757
 758                         assign_aeb_to_av(ai, aeb, av);
 759
 760                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 761                                 aeb->pnum, aeb->lnum, av->vol_id);
 762                 }
 763         }
 764
 765         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 766         if (ret)
 767                 goto fail;
 768
 769         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 770         if (ret)
 771                 goto fail;
 772
 773         if (max_sqnum > ai->max_sqnum)
 774                 ai->max_sqnum = max_sqnum;
 775
 776         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 777                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 778
 779         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 780                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 781
 782         ubi_assert(list_empty(&free));
 783
 784         /*
 785          * If fastmap is leaking PEBs (must not happen), raise a
 786          * fat warning and fall back to scanning mode.
 787          * We do this here because in ubi_wl_init() it's too late
 788          * and we cannot fall back to scanning.
 789          */
 790         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 791                     ai->bad_peb_count - fm->used_blocks))
 792                 goto fail_bad;
 793
 794         return 0;
 795
 796 fail_bad:
 797         ret = UBI_BAD_FASTMAP;
 798 fail:
 799         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 800                 list_del(&tmp_aeb->u.list);
 801                 ubi_free_aeb(ai, tmp_aeb);
 802         }
 803         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 804                 list_del(&tmp_aeb->u.list);
 805                 ubi_free_aeb(ai, tmp_aeb);
 806         }
 807
 808         return ret;
 809 }
 810
 811 /**
 812  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 813  * @ai: UBI attach info to be filled
 814  */
 815 static int find_fm_anchor(struct ubi_attach_info *ai)
 816 {
 817         int ret = -1;
 818         struct ubi_ainf_peb *aeb;
 819         unsigned long long max_sqnum = 0;
 820
 821         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 822                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 823                         max_sqnum = aeb->sqnum;
 824                         ret = aeb->pnum;
 825                 }
 826         }
 827
 828         return ret;
 829 }
 830
 831 /**
 832  * ubi_scan_fastmap - scan the fastmap.
 833  * @ubi: UBI device object
 834  * @ai: UBI attach info to be filled
 835  * @scan_ai: UBI attach info from the first 64 PEBs,
 836  *           used to find the most recent Fastmap data structure
 837  *
 838  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 839  * UBI_BAD_FASTMAP if one was found but is not usable.
 840  * < 0 indicates an internal error.
 841  */
 842 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 843                      struct ubi_attach_info *scan_ai)
 844 {
 845         struct ubi_fm_sb *fmsb, *fmsb2;
 846         struct ubi_vid_io_buf *vb;
 847         struct ubi_vid_hdr *vh;
 848         struct ubi_ec_hdr *ech;
 849         struct ubi_fastmap_layout *fm;
 850         struct ubi_ainf_peb *tmp_aeb, *aeb;
 851         int i, used_blocks, pnum, fm_anchor, ret = 0;
 852         size_t fm_size;
 853         __be32 crc, tmp_crc;
 854         unsigned long long sqnum = 0;
 855
 856         fm_anchor = find_fm_anchor(scan_ai);
 857         if (fm_anchor < 0)
 858                 return UBI_NO_FASTMAP;
 859
 860         /* Move all (possible) fastmap blocks into our new attach structure. */
 861         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 862                 list_move_tail(&aeb->u.list, &ai->fastmap);
 863
 864         down_write(&ubi->fm_protect);
 865         memset(ubi->fm_buf, 0, ubi->fm_size);
 866
 867         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 868         if (!fmsb) {
 869                 ret = -ENOMEM;
 870                 goto out;
 871         }
 872
 873         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 874         if (!fm) {
 875                 ret = -ENOMEM;
 876                 kfree(fmsb);
 877                 goto out;
 878         }
 879
 880         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 881         if (ret && ret != UBI_IO_BITFLIPS)
 882                 goto free_fm_sb;
 883         else if (ret == UBI_IO_BITFLIPS)
 884                 fm->to_be_tortured[0] = 1;
 885
 886         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 887                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 888                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 889                 ret = UBI_BAD_FASTMAP;
 890                 goto free_fm_sb;
 891         }
 892
 893         if (fmsb->version != UBI_FM_FMT_VERSION) {
 894                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 895                         fmsb->version, UBI_FM_FMT_VERSION);
 896                 ret = UBI_BAD_FASTMAP;
 897                 goto free_fm_sb;
 898         }
 899
 900         used_blocks = be32_to_cpu(fmsb->used_blocks);
 901         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 902                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 903                         used_blocks);
 904                 ret = UBI_BAD_FASTMAP;
 905                 goto free_fm_sb;
 906         }
 907
 908         fm_size = ubi->leb_size * used_blocks;
 909         if (fm_size != ubi->fm_size) {
 910                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 911                         fm_size, ubi->fm_size);
 912                 ret = UBI_BAD_FASTMAP;
 913                 goto free_fm_sb;
 914         }
 915
 916         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 917         if (!ech) {
 918                 ret = -ENOMEM;
 919                 goto free_fm_sb;
 920         }
 921
 922         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 923         if (!vb) {
 924                 ret = -ENOMEM;
 925                 goto free_hdr;
 926         }
 927
 928         vh = ubi_get_vid_hdr(vb);
 929
 930         for (i = 0; i < used_blocks; i++) {
 931                 int image_seq;
 932
 933                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 934
 935                 if (ubi_io_is_bad(ubi, pnum)) {
 936                         ret = UBI_BAD_FASTMAP;
 937                         goto free_hdr;
 938                 }
 939
 940                 if (i == 0 && pnum != fm_anchor) {
 941                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 942                                 pnum, fm_anchor);
 943                         ret = UBI_BAD_FASTMAP;
 944                         goto free_hdr;
 945                 }
 946
 947                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 948                 if (ret && ret != UBI_IO_BITFLIPS) {
 949                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 950                                 i, pnum);
 951                         if (ret > 0)
 952                                 ret = UBI_BAD_FASTMAP;
 953                         goto free_hdr;
 954                 } else if (ret == UBI_IO_BITFLIPS)
 955                         fm->to_be_tortured[i] = 1;
 956
 957                 image_seq = be32_to_cpu(ech->image_seq);
 958                 if (!ubi->image_seq)
 959                         ubi->image_seq = image_seq;
 960
 961                 /*
 962                  * Older UBI implementations have image_seq set to zero, so
 963                  * we shouldn't fail if image_seq == 0.
 964                  */
 965                 if (image_seq && (image_seq != ubi->image_seq)) {
 966                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 967                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 968                         ret = UBI_BAD_FASTMAP;
 969                         goto free_hdr;
 970                 }
 971
 972                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 973                 if (ret && ret != UBI_IO_BITFLIPS) {
 974                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 975                                 i, pnum);
 976                         goto free_hdr;
 977                 }
 978
 979                 if (i == 0) {
 980                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 981                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 982                                         be32_to_cpu(vh->vol_id),
 983                                         UBI_FM_SB_VOLUME_ID);
 984                                 ret = UBI_BAD_FASTMAP;
 985                                 goto free_hdr;
 986                         }
 987                 } else {
 988                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 989                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 990                                         be32_to_cpu(vh->vol_id),
 991                                         UBI_FM_DATA_VOLUME_ID);
 992                                 ret = UBI_BAD_FASTMAP;
 993                                 goto free_hdr;
 994                         }
 995                 }
 996
 997                 if (sqnum < be64_to_cpu(vh->sqnum))
 998                         sqnum = be64_to_cpu(vh->sqnum);
 999
1000                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1001                                        pnum, 0, ubi->leb_size);
1002                 if (ret && ret != UBI_IO_BITFLIPS) {
1003                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1004                                 "err: %i)", i, pnum, ret);
1005                         goto free_hdr;
1006                 }
1007         }
1008
1009         kfree(fmsb);
1010         fmsb = NULL;
1011
1012         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1013         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1014         fmsb2->data_crc = 0;
1015         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1016         if (crc != tmp_crc) {
1017                 ubi_err(ubi, "fastmap data CRC is invalid");
1018                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1019                         tmp_crc, crc);
1020                 ret = UBI_BAD_FASTMAP;
1021                 goto free_hdr;
1022         }
1023
1024         fmsb2->sqnum = sqnum;
1025
1026         fm->used_blocks = used_blocks;
1027
1028         ret = ubi_attach_fastmap(ubi, ai, fm);
1029         if (ret) {
1030                 if (ret > 0)
1031                         ret = UBI_BAD_FASTMAP;
1032                 goto free_hdr;
1033         }
1034
1035         for (i = 0; i < used_blocks; i++) {
1036                 struct ubi_wl_entry *e;
1037
1038                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1039                 if (!e) {
1040                         while (i--)
1041                                 kfree(fm->e[i]);
1042
1043                         ret = -ENOMEM;
1044                         goto free_hdr;
1045                 }
1046
1047                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1048                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1049                 fm->e[i] = e;
1050         }
1051
1052         ubi->fm = fm;
1053         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1054         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1055         ubi_msg(ubi, "attached by fastmap");
1056         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1057         ubi_msg(ubi, "fastmap WL pool size: %d",
1058                 ubi->fm_wl_pool.max_size);
1059         ubi->fm_disabled = 0;
1060         ubi->fast_attach = 1;
1061
1062         ubi_free_vid_buf(vb);
1063         kfree(ech);
1064 out:
1065         up_write(&ubi->fm_protect);
1066         if (ret == UBI_BAD_FASTMAP)
1067                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1068         return ret;
1069
1070 free_hdr:
1071         ubi_free_vid_buf(vb);
1072         kfree(ech);
1073 free_fm_sb:
1074         kfree(fmsb);
1075         kfree(fm);
1076         goto out;
1077 }
1078
1079 /**
1080  * ubi_write_fastmap - writes a fastmap.
1081  * @ubi: UBI device object
1082  * @new_fm: the to be written fastmap
1083  *
1084  * Returns 0 on success, < 0 indicates an internal error.
1085  */
1086 static int ubi_write_fastmap(struct ubi_device *ubi,
1087                              struct ubi_fastmap_layout *new_fm)
1088 {
1089         size_t fm_pos = 0;
1090         void *fm_raw;
1091         struct ubi_fm_sb *fmsb;
1092         struct ubi_fm_hdr *fmh;
1093         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1094         struct ubi_fm_ec *fec;
1095         struct ubi_fm_volhdr *fvh;
1096         struct ubi_fm_eba *feba;
1097         struct ubi_wl_entry *wl_e;
1098         struct ubi_volume *vol;
1099         struct ubi_vid_io_buf *avbuf, *dvbuf;
1100         struct ubi_vid_hdr *avhdr, *dvhdr;
1101         struct ubi_work *ubi_wrk;
1102         struct rb_node *tmp_rb;
1103         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1104         int scrub_peb_count, erase_peb_count;
1105         unsigned long *seen_pebs = NULL;
1106
1107         fm_raw = ubi->fm_buf;
1108         memset(ubi->fm_buf, 0, ubi->fm_size);
1109
1110         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1111         if (!avbuf) {
1112                 ret = -ENOMEM;
1113                 goto out;
1114         }
1115
1116         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1117         if (!dvbuf) {
1118                 ret = -ENOMEM;
1119                 goto out_kfree;
1120         }
1121
1122         avhdr = ubi_get_vid_hdr(avbuf);
1123         dvhdr = ubi_get_vid_hdr(dvbuf);
1124
1125         seen_pebs = init_seen(ubi);
1126         if (IS_ERR(seen_pebs)) {
1127                 ret = PTR_ERR(seen_pebs);
1128                 goto out_kfree;
1129         }
1130
1131         spin_lock(&ubi->volumes_lock);
1132         spin_lock(&ubi->wl_lock);
1133
1134         fmsb = (struct ubi_fm_sb *)fm_raw;
1135         fm_pos += sizeof(*fmsb);
1136         ubi_assert(fm_pos <= ubi->fm_size);
1137
1138         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1139         fm_pos += sizeof(*fmh);
1140         ubi_assert(fm_pos <= ubi->fm_size);
1141
1142         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1143         fmsb->version = UBI_FM_FMT_VERSION;
1144         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1145         /* the max sqnum will be filled in while *reading* the fastmap */
1146         fmsb->sqnum = 0;
1147
1148         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1149         free_peb_count = 0;
1150         used_peb_count = 0;
1151         scrub_peb_count = 0;
1152         erase_peb_count = 0;
1153         vol_count = 0;
1154
1155         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1156         fm_pos += sizeof(*fmpl);
1157         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1158         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1159         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1160
1161         for (i = 0; i < ubi->fm_pool.size; i++) {
1162                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1163                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1164         }
1165
1166         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1167         fm_pos += sizeof(*fmpl_wl);
1168         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1169         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1170         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1171
1172         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1173                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1174                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1175         }
1176
1177         ubi_for_each_free_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                 free_peb_count++;
1185                 fm_pos += sizeof(*fec);
1186                 ubi_assert(fm_pos <= ubi->fm_size);
1187         }
1188         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1189
1190         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1191                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1192
1193                 fec->pnum = cpu_to_be32(wl_e->pnum);
1194                 set_seen(ubi, wl_e->pnum, seen_pebs);
1195                 fec->ec = cpu_to_be32(wl_e->ec);
1196
1197                 used_peb_count++;
1198                 fm_pos += sizeof(*fec);
1199                 ubi_assert(fm_pos <= ubi->fm_size);
1200         }
1201
1202         ubi_for_each_protected_peb(ubi, i, wl_e) {
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                 used_peb_count++;
1210                 fm_pos += sizeof(*fec);
1211                 ubi_assert(fm_pos <= ubi->fm_size);
1212         }
1213         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1214
1215         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1216                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1217
1218                 fec->pnum = cpu_to_be32(wl_e->pnum);
1219                 set_seen(ubi, wl_e->pnum, seen_pebs);
1220                 fec->ec = cpu_to_be32(wl_e->ec);
1221
1222                 scrub_peb_count++;
1223                 fm_pos += sizeof(*fec);
1224                 ubi_assert(fm_pos <= ubi->fm_size);
1225         }
1226         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1227
1228
1229         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1230                 if (ubi_is_erase_work(ubi_wrk)) {
1231                         wl_e = ubi_wrk->e;
1232                         ubi_assert(wl_e);
1233
1234                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1235
1236                         fec->pnum = cpu_to_be32(wl_e->pnum);
1237                         set_seen(ubi, wl_e->pnum, seen_pebs);
1238                         fec->ec = cpu_to_be32(wl_e->ec);
1239
1240                         erase_peb_count++;
1241                         fm_pos += sizeof(*fec);
1242                         ubi_assert(fm_pos <= ubi->fm_size);
1243                 }
1244         }
1245         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1246
1247         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1248                 vol = ubi->volumes[i];
1249
1250                 if (!vol)
1251                         continue;
1252
1253                 vol_count++;
1254
1255                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1256                 fm_pos += sizeof(*fvh);
1257                 ubi_assert(fm_pos <= ubi->fm_size);
1258
1259                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1260                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1261                 fvh->vol_type = vol->vol_type;
1262                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1263                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1264                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1265
1266                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1267                         vol->vol_type == UBI_STATIC_VOLUME);
1268
1269                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1270                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1271                 ubi_assert(fm_pos <= ubi->fm_size);
1272
1273                 for (j = 0; j < vol->reserved_pebs; j++) {
1274                         struct ubi_eba_leb_desc ldesc;
1275
1276                         ubi_eba_get_ldesc(vol, j, &ldesc);
1277                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1278                 }
1279
1280                 feba->reserved_pebs = cpu_to_be32(j);
1281                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1282         }
1283         fmh->vol_count = cpu_to_be32(vol_count);
1284         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1285
1286         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1287         avhdr->lnum = 0;
1288
1289         spin_unlock(&ubi->wl_lock);
1290         spin_unlock(&ubi->volumes_lock);
1291
1292         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1293         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1294         if (ret) {
1295                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1296                 goto out_kfree;
1297         }
1298
1299         for (i = 0; i < new_fm->used_blocks; i++) {
1300                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1301                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1302                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1303         }
1304
1305         fmsb->data_crc = 0;
1306         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1307                                            ubi->fm_size));
1308
1309         for (i = 1; i < new_fm->used_blocks; i++) {
1310                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1311                 dvhdr->lnum = cpu_to_be32(i);
1312                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1313                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1314                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1315                 if (ret) {
1316                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1317                                 new_fm->e[i]->pnum);
1318                         goto out_kfree;
1319                 }
1320         }
1321
1322         for (i = 0; i < new_fm->used_blocks; i++) {
1323                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1324                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1325                 if (ret) {
1326                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1327                                 new_fm->e[i]->pnum);
1328                         goto out_kfree;
1329                 }
1330         }
1331
1332         ubi_assert(new_fm);
1333         ubi->fm = new_fm;
1334
1335         ret = self_check_seen(ubi, seen_pebs);
1336         dbg_bld("fastmap written!");
1337
1338 out_kfree:
1339         ubi_free_vid_buf(avbuf);
1340         ubi_free_vid_buf(dvbuf);
1341         free_seen(seen_pebs);
1342 out:
1343         return ret;
1344 }
1345
1346 /**
1347  * erase_block - Manually erase a PEB.
1348  * @ubi: UBI device object
1349  * @pnum: PEB to be erased
1350  *
1351  * Returns the new EC value on success, < 0 indicates an internal error.
1352  */
1353 static int erase_block(struct ubi_device *ubi, int pnum)
1354 {
1355         int ret;
1356         struct ubi_ec_hdr *ec_hdr;
1357         long long ec;
1358
1359         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1360         if (!ec_hdr)
1361                 return -ENOMEM;
1362
1363         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1364         if (ret < 0)
1365                 goto out;
1366         else if (ret && ret != UBI_IO_BITFLIPS) {
1367                 ret = -EINVAL;
1368                 goto out;
1369         }
1370
1371         ret = ubi_io_sync_erase(ubi, pnum, 0);
1372         if (ret < 0)
1373                 goto out;
1374
1375         ec = be64_to_cpu(ec_hdr->ec);
1376         ec += ret;
1377         if (ec > UBI_MAX_ERASECOUNTER) {
1378                 ret = -EINVAL;
1379                 goto out;
1380         }
1381
1382         ec_hdr->ec = cpu_to_be64(ec);
1383         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1384         if (ret < 0)
1385                 goto out;
1386
1387         ret = ec;
1388 out:
1389         kfree(ec_hdr);
1390         return ret;
1391 }
1392
1393 /**
1394  * invalidate_fastmap - destroys a fastmap.
1395  * @ubi: UBI device object
1396  *
1397  * This function ensures that upon next UBI attach a full scan
1398  * is issued. We need this if UBI is about to write a new fastmap
1399  * but is unable to do so. In this case we have two options:
1400  * a) Make sure that the current fastmap will not be usued upon
1401  * attach time and contine or b) fall back to RO mode to have the
1402  * current fastmap in a valid state.
1403  * Returns 0 on success, < 0 indicates an internal error.
1404  */
1405 static int invalidate_fastmap(struct ubi_device *ubi)
1406 {
1407         int ret;
1408         struct ubi_fastmap_layout *fm;
1409         struct ubi_wl_entry *e;
1410         struct ubi_vid_io_buf *vb = NULL;
1411         struct ubi_vid_hdr *vh;
1412
1413         if (!ubi->fm)
1414                 return 0;
1415
1416         ubi->fm = NULL;
1417
1418         ret = -ENOMEM;
1419         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1420         if (!fm)
1421                 goto out;
1422
1423         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1424         if (!vb)
1425                 goto out_free_fm;
1426
1427         vh = ubi_get_vid_hdr(vb);
1428
1429         ret = -ENOSPC;
1430         e = ubi_wl_get_fm_peb(ubi, 1);
1431         if (!e)
1432                 goto out_free_fm;
1433
1434         /*
1435          * Create fake fastmap such that UBI will fall back
1436          * to scanning mode.
1437          */
1438         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1439         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1440         if (ret < 0) {
1441                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1442                 goto out_free_fm;
1443         }
1444
1445         fm->used_blocks = 1;
1446         fm->e[0] = e;
1447
1448         ubi->fm = fm;
1449
1450 out:
1451         ubi_free_vid_buf(vb);
1452         return ret;
1453
1454 out_free_fm:
1455         kfree(fm);
1456         goto out;
1457 }
1458
1459 /**
1460  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1461  * WL sub-system.
1462  * @ubi: UBI device object
1463  * @fm: fastmap layout object
1464  */
1465 static void return_fm_pebs(struct ubi_device *ubi,
1466                            struct ubi_fastmap_layout *fm)
1467 {
1468         int i;
1469
1470         if (!fm)
1471                 return;
1472
1473         for (i = 0; i < fm->used_blocks; i++) {
1474                 if (fm->e[i]) {
1475                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1476                                           fm->to_be_tortured[i]);
1477                         fm->e[i] = NULL;
1478                 }
1479         }
1480 }
1481
1482 /**
1483  * ubi_update_fastmap - will be called by UBI if a volume changes or
1484  * a fastmap pool becomes full.
1485  * @ubi: UBI device object
1486  *
1487  * Returns 0 on success, < 0 indicates an internal error.
1488  */
1489 int ubi_update_fastmap(struct ubi_device *ubi)
1490 {
1491         int ret, i, j;
1492         struct ubi_fastmap_layout *new_fm, *old_fm;
1493         struct ubi_wl_entry *tmp_e;
1494
1495         down_write(&ubi->fm_protect);
1496         down_write(&ubi->work_sem);
1497         down_write(&ubi->fm_eba_sem);
1498
1499         ubi_refill_pools(ubi);
1500
1501         if (ubi->ro_mode || ubi->fm_disabled) {
1502                 up_write(&ubi->fm_eba_sem);
1503                 up_write(&ubi->work_sem);
1504                 up_write(&ubi->fm_protect);
1505                 return 0;
1506         }
1507
1508         ret = ubi_ensure_anchor_pebs(ubi);
1509         if (ret) {
1510                 up_write(&ubi->fm_eba_sem);
1511                 up_write(&ubi->work_sem);
1512                 up_write(&ubi->fm_protect);
1513                 return ret;
1514         }
1515
1516         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1517         if (!new_fm) {
1518                 up_write(&ubi->fm_eba_sem);
1519                 up_write(&ubi->work_sem);
1520                 up_write(&ubi->fm_protect);
1521                 return -ENOMEM;
1522         }
1523
1524         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1525         old_fm = ubi->fm;
1526         ubi->fm = NULL;
1527
1528         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1529                 ubi_err(ubi, "fastmap too large");
1530                 ret = -ENOSPC;
1531                 goto err;
1532         }
1533
1534         for (i = 1; i < new_fm->used_blocks; i++) {
1535                 spin_lock(&ubi->wl_lock);
1536                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1537                 spin_unlock(&ubi->wl_lock);
1538
1539                 if (!tmp_e) {
1540                         if (old_fm && old_fm->e[i]) {
1541                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1542                                 if (ret < 0) {
1543                                         ubi_err(ubi, "could not erase old fastmap PEB");
1544
1545                                         for (j = 1; j < i; j++) {
1546                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1547                                                                   j, 0);
1548                                                 new_fm->e[j] = NULL;
1549                                         }
1550                                         goto err;
1551                                 }
1552                                 new_fm->e[i] = old_fm->e[i];
1553                                 old_fm->e[i] = NULL;
1554                         } else {
1555                                 ubi_err(ubi, "could not get any free erase block");
1556
1557                                 for (j = 1; j < i; j++) {
1558                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1559                                         new_fm->e[j] = NULL;
1560                                 }
1561
1562                                 ret = -ENOSPC;
1563                                 goto err;
1564                         }
1565                 } else {
1566                         new_fm->e[i] = tmp_e;
1567
1568                         if (old_fm && old_fm->e[i]) {
1569                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1570                                                   old_fm->to_be_tortured[i]);
1571                                 old_fm->e[i] = NULL;
1572                         }
1573                 }
1574         }
1575
1576         /* Old fastmap is larger than the new one */
1577         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1578                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1579                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1580                                           old_fm->to_be_tortured[i]);
1581                         old_fm->e[i] = NULL;
1582                 }
1583         }
1584
1585         spin_lock(&ubi->wl_lock);
1586         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1587         spin_unlock(&ubi->wl_lock);
1588
1589         if (old_fm) {
1590                 /* no fresh anchor PEB was found, reuse the old one */
1591                 if (!tmp_e) {
1592                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1593                         if (ret < 0) {
1594                                 ubi_err(ubi, "could not erase old anchor PEB");
1595
1596                                 for (i = 1; i < new_fm->used_blocks; i++) {
1597                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1598                                                           i, 0);
1599                                         new_fm->e[i] = NULL;
1600                                 }
1601                                 goto err;
1602                         }
1603                         new_fm->e[0] = old_fm->e[0];
1604                         new_fm->e[0]->ec = ret;
1605                         old_fm->e[0] = NULL;
1606                 } else {
1607                         /* we've got a new anchor PEB, return the old one */
1608                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1609                                           old_fm->to_be_tortured[0]);
1610                         new_fm->e[0] = tmp_e;
1611                         old_fm->e[0] = NULL;
1612                 }
1613         } else {
1614                 if (!tmp_e) {
1615                         ubi_err(ubi, "could not find any anchor PEB");
1616
1617                         for (i = 1; i < new_fm->used_blocks; i++) {
1618                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1619                                 new_fm->e[i] = NULL;
1620                         }
1621
1622                         ret = -ENOSPC;
1623                         goto err;
1624                 }
1625                 new_fm->e[0] = tmp_e;
1626         }
1627
1628         ret = ubi_write_fastmap(ubi, new_fm);
1629
1630         if (ret)
1631                 goto err;
1632
1633 out_unlock:
1634         up_write(&ubi->fm_eba_sem);
1635         up_write(&ubi->work_sem);
1636         up_write(&ubi->fm_protect);
1637         kfree(old_fm);
1638         return ret;
1639
1640 err:
1641         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1642
1643         ret = invalidate_fastmap(ubi);
1644         if (ret < 0) {
1645                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1646                 ubi_ro_mode(ubi);
1647         } else {
1648                 return_fm_pebs(ubi, old_fm);
1649                 return_fm_pebs(ubi, new_fm);
1650                 ret = 0;
1651         }
1652
1653         kfree(new_fm);
1654         goto out_unlock;
1655 }