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                         ret = add_aeb(ai, free, pnum, ec, scrub);
 482                         if (ret)
 483                                 goto out;
 484                         continue;
 485                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 486                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 487
 488                         if (err == UBI_IO_BITFLIPS)
 489                                 scrub = 1;
 490
 491                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 492                         if (!new_aeb) {
 493                                 ret = -ENOMEM;
 494                                 goto out;
 495                         }
 496
 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_buf(vb);
 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                 ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 654                               be32_to_cpu(fmec->ec), 0);
 655                 if (ret)
 656                         goto fail;
 657         }
 658
 659         /* read EC values from used list */
 660         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 661                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 662                 fm_pos += sizeof(*fmec);
 663                 if (fm_pos >= fm_size)
 664                         goto fail_bad;
 665
 666                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 667                               be32_to_cpu(fmec->ec), 0);
 668                 if (ret)
 669                         goto fail;
 670         }
 671
 672         /* read EC values from scrub list */
 673         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 674                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 675                 fm_pos += sizeof(*fmec);
 676                 if (fm_pos >= fm_size)
 677                         goto fail_bad;
 678
 679                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 680                               be32_to_cpu(fmec->ec), 1);
 681                 if (ret)
 682                         goto fail;
 683         }
 684
 685         /* read EC values from erase list */
 686         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 687                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 688                 fm_pos += sizeof(*fmec);
 689                 if (fm_pos >= fm_size)
 690                         goto fail_bad;
 691
 692                 ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 693                               be32_to_cpu(fmec->ec), 1);
 694                 if (ret)
 695                         goto fail;
 696         }
 697
 698         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 699         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 700
 701         /* Iterate over all volumes and read their EBA table */
 702         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 703                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 704                 fm_pos += sizeof(*fmvhdr);
 705                 if (fm_pos >= fm_size)
 706                         goto fail_bad;
 707
 708                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 709                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 710                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 711                         goto fail_bad;
 712                 }
 713
 714                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 715                              be32_to_cpu(fmvhdr->used_ebs),
 716                              be32_to_cpu(fmvhdr->data_pad),
 717                              fmvhdr->vol_type,
 718                              be32_to_cpu(fmvhdr->last_eb_bytes));
 719
 720                 if (IS_ERR(av)) {
 721                         if (PTR_ERR(av) == -EEXIST)
 722                                 ubi_err(ubi, "volume (ID %i) already exists",
 723                                         fmvhdr->vol_id);
 724
 725                         goto fail_bad;
 726                 }
 727
 728                 ai->vols_found++;
 729                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 730                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 731
 732                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 733                 fm_pos += sizeof(*fm_eba);
 734                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 735                 if (fm_pos >= fm_size)
 736                         goto fail_bad;
 737
 738                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 739                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 740                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 741                         goto fail_bad;
 742                 }
 743
 744                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 745                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 746
 747                         if (pnum < 0)
 748                                 continue;
 749
 750                         aeb = NULL;
 751                         list_for_each_entry(tmp_aeb, &used, u.list) {
 752                                 if (tmp_aeb->pnum == pnum) {
 753                                         aeb = tmp_aeb;
 754                                         break;
 755                                 }
 756                         }
 757
 758                         if (!aeb) {
 759                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 760                                 goto fail_bad;
 761                         }
 762
 763                         aeb->lnum = j;
 764
 765                         if (av->highest_lnum <= aeb->lnum)
 766                                 av->highest_lnum = aeb->lnum;
 767
 768                         assign_aeb_to_av(ai, aeb, av);
 769
 770                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 771                                 aeb->pnum, aeb->lnum, av->vol_id);
 772                 }
 773         }
 774
 775         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 776         if (ret)
 777                 goto fail;
 778
 779         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 780         if (ret)
 781                 goto fail;
 782
 783         if (max_sqnum > ai->max_sqnum)
 784                 ai->max_sqnum = max_sqnum;
 785
 786         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 787                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 788
 789         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 790                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 791
 792         ubi_assert(list_empty(&free));
 793
 794         /*
 795          * If fastmap is leaking PEBs (must not happen), raise a
 796          * fat warning and fall back to scanning mode.
 797          * We do this here because in ubi_wl_init() it's too late
 798          * and we cannot fall back to scanning.
 799          */
 800         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 801                     ai->bad_peb_count - fm->used_blocks))
 802                 goto fail_bad;
 803
 804         return 0;
 805
 806 fail_bad:
 807         ret = UBI_BAD_FASTMAP;
 808 fail:
 809         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 810                 list_del(&tmp_aeb->u.list);
 811                 ubi_free_aeb(ai, tmp_aeb);
 812         }
 813         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 814                 list_del(&tmp_aeb->u.list);
 815                 ubi_free_aeb(ai, tmp_aeb);
 816         }
 817
 818         return ret;
 819 }
 820
 821 /**
 822  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 823  * @ai: UBI attach info to be filled
 824  */
 825 static int find_fm_anchor(struct ubi_attach_info *ai)
 826 {
 827         int ret = -1;
 828         struct ubi_ainf_peb *aeb;
 829         unsigned long long max_sqnum = 0;
 830
 831         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 832                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 833                         max_sqnum = aeb->sqnum;
 834                         ret = aeb->pnum;
 835                 }
 836         }
 837
 838         return ret;
 839 }
 840
 841 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 842                                       struct ubi_ainf_peb *old)
 843 {
 844         struct ubi_ainf_peb *new;
 845
 846         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 847         if (!new)
 848                 return NULL;
 849
 850         new->vol_id = old->vol_id;
 851         new->sqnum = old->sqnum;
 852         new->lnum = old->lnum;
 853         new->scrub = old->scrub;
 854         new->copy_flag = old->copy_flag;
 855
 856         return new;
 857 }
 858
 859 /**
 860  * ubi_scan_fastmap - scan the fastmap.
 861  * @ubi: UBI device object
 862  * @ai: UBI attach info to be filled
 863  * @scan_ai: UBI attach info from the first 64 PEBs,
 864  *           used to find the most recent Fastmap data structure
 865  *
 866  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 867  * UBI_BAD_FASTMAP if one was found but is not usable.
 868  * < 0 indicates an internal error.
 869  */
 870 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 871                      struct ubi_attach_info *scan_ai)
 872 {
 873         struct ubi_fm_sb *fmsb, *fmsb2;
 874         struct ubi_vid_io_buf *vb;
 875         struct ubi_vid_hdr *vh;
 876         struct ubi_ec_hdr *ech;
 877         struct ubi_fastmap_layout *fm;
 878         struct ubi_ainf_peb *aeb;
 879         int i, used_blocks, pnum, fm_anchor, ret = 0;
 880         size_t fm_size;
 881         __be32 crc, tmp_crc;
 882         unsigned long long sqnum = 0;
 883
 884         fm_anchor = find_fm_anchor(scan_ai);
 885         if (fm_anchor < 0)
 886                 return UBI_NO_FASTMAP;
 887
 888         /* Copy all (possible) fastmap blocks into our new attach structure. */
 889         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 890                 struct ubi_ainf_peb *new;
 891
 892                 new = clone_aeb(ai, aeb);
 893                 if (!new)
 894                         return -ENOMEM;
 895
 896                 list_add(&new->u.list, &ai->fastmap);
 897         }
 898
 899         down_write(&ubi->fm_protect);
 900         memset(ubi->fm_buf, 0, ubi->fm_size);
 901
 902         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 903         if (!fmsb) {
 904                 ret = -ENOMEM;
 905                 goto out;
 906         }
 907
 908         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 909         if (!fm) {
 910                 ret = -ENOMEM;
 911                 kfree(fmsb);
 912                 goto out;
 913         }
 914
 915         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 916         if (ret && ret != UBI_IO_BITFLIPS)
 917                 goto free_fm_sb;
 918         else if (ret == UBI_IO_BITFLIPS)
 919                 fm->to_be_tortured[0] = 1;
 920
 921         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 922                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 923                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 924                 ret = UBI_BAD_FASTMAP;
 925                 goto free_fm_sb;
 926         }
 927
 928         if (fmsb->version != UBI_FM_FMT_VERSION) {
 929                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 930                         fmsb->version, UBI_FM_FMT_VERSION);
 931                 ret = UBI_BAD_FASTMAP;
 932                 goto free_fm_sb;
 933         }
 934
 935         used_blocks = be32_to_cpu(fmsb->used_blocks);
 936         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 937                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 938                         used_blocks);
 939                 ret = UBI_BAD_FASTMAP;
 940                 goto free_fm_sb;
 941         }
 942
 943         fm_size = ubi->leb_size * used_blocks;
 944         if (fm_size != ubi->fm_size) {
 945                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 946                         fm_size, ubi->fm_size);
 947                 ret = UBI_BAD_FASTMAP;
 948                 goto free_fm_sb;
 949         }
 950
 951         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 952         if (!ech) {
 953                 ret = -ENOMEM;
 954                 goto free_fm_sb;
 955         }
 956
 957         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 958         if (!vb) {
 959                 ret = -ENOMEM;
 960                 goto free_hdr;
 961         }
 962
 963         vh = ubi_get_vid_hdr(vb);
 964
 965         for (i = 0; i < used_blocks; i++) {
 966                 int image_seq;
 967
 968                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 969
 970                 if (ubi_io_is_bad(ubi, pnum)) {
 971                         ret = UBI_BAD_FASTMAP;
 972                         goto free_hdr;
 973                 }
 974
 975                 if (i == 0 && pnum != fm_anchor) {
 976                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 977                                 pnum, fm_anchor);
 978                         ret = UBI_BAD_FASTMAP;
 979                         goto free_hdr;
 980                 }
 981
 982                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 983                 if (ret && ret != UBI_IO_BITFLIPS) {
 984                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 985                                 i, pnum);
 986                         if (ret > 0)
 987                                 ret = UBI_BAD_FASTMAP;
 988                         goto free_hdr;
 989                 } else if (ret == UBI_IO_BITFLIPS)
 990                         fm->to_be_tortured[i] = 1;
 991
 992                 image_seq = be32_to_cpu(ech->image_seq);
 993                 if (!ubi->image_seq)
 994                         ubi->image_seq = image_seq;
 995
 996                 /*
 997                  * Older UBI implementations have image_seq set to zero, so
 998                  * we shouldn't fail if image_seq == 0.
 999                  */
1000                 if (image_seq && (image_seq != ubi->image_seq)) {
1001                         ubi_err(ubi, "wrong image seq:%d instead of %d",
1002                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
1003                         ret = UBI_BAD_FASTMAP;
1004                         goto free_hdr;
1005                 }
1006
1007                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
1008                 if (ret && ret != UBI_IO_BITFLIPS) {
1009                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1010                                 i, pnum);
1011                         goto free_hdr;
1012                 }
1013
1014                 if (i == 0) {
1015                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1016                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1017                                         be32_to_cpu(vh->vol_id),
1018                                         UBI_FM_SB_VOLUME_ID);
1019                                 ret = UBI_BAD_FASTMAP;
1020                                 goto free_hdr;
1021                         }
1022                 } else {
1023                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1024                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1025                                         be32_to_cpu(vh->vol_id),
1026                                         UBI_FM_DATA_VOLUME_ID);
1027                                 ret = UBI_BAD_FASTMAP;
1028                                 goto free_hdr;
1029                         }
1030                 }
1031
1032                 if (sqnum < be64_to_cpu(vh->sqnum))
1033                         sqnum = be64_to_cpu(vh->sqnum);
1034
1035                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1036                                        pnum, 0, ubi->leb_size);
1037                 if (ret && ret != UBI_IO_BITFLIPS) {
1038                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1039                                 "err: %i)", i, pnum, ret);
1040                         goto free_hdr;
1041                 }
1042         }
1043
1044         kfree(fmsb);
1045         fmsb = NULL;
1046
1047         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1048         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1049         fmsb2->data_crc = 0;
1050         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1051         if (crc != tmp_crc) {
1052                 ubi_err(ubi, "fastmap data CRC is invalid");
1053                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1054                         tmp_crc, crc);
1055                 ret = UBI_BAD_FASTMAP;
1056                 goto free_hdr;
1057         }
1058
1059         fmsb2->sqnum = sqnum;
1060
1061         fm->used_blocks = used_blocks;
1062
1063         ret = ubi_attach_fastmap(ubi, ai, fm);
1064         if (ret) {
1065                 if (ret > 0)
1066                         ret = UBI_BAD_FASTMAP;
1067                 goto free_hdr;
1068         }
1069
1070         for (i = 0; i < used_blocks; i++) {
1071                 struct ubi_wl_entry *e;
1072
1073                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1074                 if (!e) {
1075                         while (i--)
1076                                 kfree(fm->e[i]);
1077
1078                         ret = -ENOMEM;
1079                         goto free_hdr;
1080                 }
1081
1082                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1083                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1084                 fm->e[i] = e;
1085         }
1086
1087         ubi->fm = fm;
1088         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1089         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1090         ubi_msg(ubi, "attached by fastmap");
1091         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1092         ubi_msg(ubi, "fastmap WL pool size: %d",
1093                 ubi->fm_wl_pool.max_size);
1094         ubi->fm_disabled = 0;
1095         ubi->fast_attach = 1;
1096
1097         ubi_free_vid_buf(vb);
1098         kfree(ech);
1099 out:
1100         up_write(&ubi->fm_protect);
1101         if (ret == UBI_BAD_FASTMAP)
1102                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1103         return ret;
1104
1105 free_hdr:
1106         ubi_free_vid_buf(vb);
1107         kfree(ech);
1108 free_fm_sb:
1109         kfree(fmsb);
1110         kfree(fm);
1111         goto out;
1112 }
1113
1114 /**
1115  * ubi_write_fastmap - writes a fastmap.
1116  * @ubi: UBI device object
1117  * @new_fm: the to be written fastmap
1118  *
1119  * Returns 0 on success, < 0 indicates an internal error.
1120  */
1121 static int ubi_write_fastmap(struct ubi_device *ubi,
1122                              struct ubi_fastmap_layout *new_fm)
1123 {
1124         size_t fm_pos = 0;
1125         void *fm_raw;
1126         struct ubi_fm_sb *fmsb;
1127         struct ubi_fm_hdr *fmh;
1128         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1129         struct ubi_fm_ec *fec;
1130         struct ubi_fm_volhdr *fvh;
1131         struct ubi_fm_eba *feba;
1132         struct ubi_wl_entry *wl_e;
1133         struct ubi_volume *vol;
1134         struct ubi_vid_io_buf *avbuf, *dvbuf;
1135         struct ubi_vid_hdr *avhdr, *dvhdr;
1136         struct ubi_work *ubi_wrk;
1137         struct rb_node *tmp_rb;
1138         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1139         int scrub_peb_count, erase_peb_count;
1140         unsigned long *seen_pebs;
1141
1142         fm_raw = ubi->fm_buf;
1143         memset(ubi->fm_buf, 0, ubi->fm_size);
1144
1145         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1146         if (!avbuf) {
1147                 ret = -ENOMEM;
1148                 goto out;
1149         }
1150
1151         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1152         if (!dvbuf) {
1153                 ret = -ENOMEM;
1154                 goto out_free_avbuf;
1155         }
1156
1157         avhdr = ubi_get_vid_hdr(avbuf);
1158         dvhdr = ubi_get_vid_hdr(dvbuf);
1159
1160         seen_pebs = init_seen(ubi);
1161         if (IS_ERR(seen_pebs)) {
1162                 ret = PTR_ERR(seen_pebs);
1163                 goto out_free_dvbuf;
1164         }
1165
1166         spin_lock(&ubi->volumes_lock);
1167         spin_lock(&ubi->wl_lock);
1168
1169         fmsb = (struct ubi_fm_sb *)fm_raw;
1170         fm_pos += sizeof(*fmsb);
1171         ubi_assert(fm_pos <= ubi->fm_size);
1172
1173         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1174         fm_pos += sizeof(*fmh);
1175         ubi_assert(fm_pos <= ubi->fm_size);
1176
1177         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1178         fmsb->version = UBI_FM_FMT_VERSION;
1179         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1180         /* the max sqnum will be filled in while *reading* the fastmap */
1181         fmsb->sqnum = 0;
1182
1183         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1184         free_peb_count = 0;
1185         used_peb_count = 0;
1186         scrub_peb_count = 0;
1187         erase_peb_count = 0;
1188         vol_count = 0;
1189
1190         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1191         fm_pos += sizeof(*fmpl);
1192         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1193         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1194         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1195
1196         for (i = 0; i < ubi->fm_pool.size; i++) {
1197                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1198                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1199         }
1200
1201         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1202         fm_pos += sizeof(*fmpl_wl);
1203         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1204         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1205         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1206
1207         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1208                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1209                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1210         }
1211
1212         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1213                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1214
1215                 fec->pnum = cpu_to_be32(wl_e->pnum);
1216                 set_seen(ubi, wl_e->pnum, seen_pebs);
1217                 fec->ec = cpu_to_be32(wl_e->ec);
1218
1219                 free_peb_count++;
1220                 fm_pos += sizeof(*fec);
1221                 ubi_assert(fm_pos <= ubi->fm_size);
1222         }
1223         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1224
1225         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1226                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1227
1228                 fec->pnum = cpu_to_be32(wl_e->pnum);
1229                 set_seen(ubi, wl_e->pnum, seen_pebs);
1230                 fec->ec = cpu_to_be32(wl_e->ec);
1231
1232                 used_peb_count++;
1233                 fm_pos += sizeof(*fec);
1234                 ubi_assert(fm_pos <= ubi->fm_size);
1235         }
1236
1237         ubi_for_each_protected_peb(ubi, i, wl_e) {
1238                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1239
1240                 fec->pnum = cpu_to_be32(wl_e->pnum);
1241                 set_seen(ubi, wl_e->pnum, seen_pebs);
1242                 fec->ec = cpu_to_be32(wl_e->ec);
1243
1244                 used_peb_count++;
1245                 fm_pos += sizeof(*fec);
1246                 ubi_assert(fm_pos <= ubi->fm_size);
1247         }
1248         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1249
1250         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1251                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1252
1253                 fec->pnum = cpu_to_be32(wl_e->pnum);
1254                 set_seen(ubi, wl_e->pnum, seen_pebs);
1255                 fec->ec = cpu_to_be32(wl_e->ec);
1256
1257                 scrub_peb_count++;
1258                 fm_pos += sizeof(*fec);
1259                 ubi_assert(fm_pos <= ubi->fm_size);
1260         }
1261         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1262
1263
1264         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1265                 if (ubi_is_erase_work(ubi_wrk)) {
1266                         wl_e = ubi_wrk->e;
1267                         ubi_assert(wl_e);
1268
1269                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1270
1271                         fec->pnum = cpu_to_be32(wl_e->pnum);
1272                         set_seen(ubi, wl_e->pnum, seen_pebs);
1273                         fec->ec = cpu_to_be32(wl_e->ec);
1274
1275                         erase_peb_count++;
1276                         fm_pos += sizeof(*fec);
1277                         ubi_assert(fm_pos <= ubi->fm_size);
1278                 }
1279         }
1280         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1281
1282         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1283                 vol = ubi->volumes[i];
1284
1285                 if (!vol)
1286                         continue;
1287
1288                 vol_count++;
1289
1290                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1291                 fm_pos += sizeof(*fvh);
1292                 ubi_assert(fm_pos <= ubi->fm_size);
1293
1294                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1295                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1296                 fvh->vol_type = vol->vol_type;
1297                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1298                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1299                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1300
1301                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1302                         vol->vol_type == UBI_STATIC_VOLUME);
1303
1304                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1305                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1306                 ubi_assert(fm_pos <= ubi->fm_size);
1307
1308                 for (j = 0; j < vol->reserved_pebs; j++) {
1309                         struct ubi_eba_leb_desc ldesc;
1310
1311                         ubi_eba_get_ldesc(vol, j, &ldesc);
1312                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1313                 }
1314
1315                 feba->reserved_pebs = cpu_to_be32(j);
1316                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1317         }
1318         fmh->vol_count = cpu_to_be32(vol_count);
1319         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1320
1321         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1322         avhdr->lnum = 0;
1323
1324         spin_unlock(&ubi->wl_lock);
1325         spin_unlock(&ubi->volumes_lock);
1326
1327         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1328         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1329         if (ret) {
1330                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1331                 goto out_free_seen;
1332         }
1333
1334         for (i = 0; i < new_fm->used_blocks; i++) {
1335                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1336                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1337                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1338         }
1339
1340         fmsb->data_crc = 0;
1341         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1342                                            ubi->fm_size));
1343
1344         for (i = 1; i < new_fm->used_blocks; i++) {
1345                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1346                 dvhdr->lnum = cpu_to_be32(i);
1347                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1348                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1349                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1350                 if (ret) {
1351                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1352                                 new_fm->e[i]->pnum);
1353                         goto out_free_seen;
1354                 }
1355         }
1356
1357         for (i = 0; i < new_fm->used_blocks; i++) {
1358                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1359                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1360                 if (ret) {
1361                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1362                                 new_fm->e[i]->pnum);
1363                         goto out_free_seen;
1364                 }
1365         }
1366
1367         ubi_assert(new_fm);
1368         ubi->fm = new_fm;
1369
1370         ret = self_check_seen(ubi, seen_pebs);
1371         dbg_bld("fastmap written!");
1372
1373 out_free_seen:
1374         free_seen(seen_pebs);
1375 out_free_dvbuf:
1376         ubi_free_vid_buf(dvbuf);
1377 out_free_avbuf:
1378         ubi_free_vid_buf(avbuf);
1379
1380 out:
1381         return ret;
1382 }
1383
1384 /**
1385  * erase_block - Manually erase a PEB.
1386  * @ubi: UBI device object
1387  * @pnum: PEB to be erased
1388  *
1389  * Returns the new EC value on success, < 0 indicates an internal error.
1390  */
1391 static int erase_block(struct ubi_device *ubi, int pnum)
1392 {
1393         int ret;
1394         struct ubi_ec_hdr *ec_hdr;
1395         long long ec;
1396
1397         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1398         if (!ec_hdr)
1399                 return -ENOMEM;
1400
1401         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1402         if (ret < 0)
1403                 goto out;
1404         else if (ret && ret != UBI_IO_BITFLIPS) {
1405                 ret = -EINVAL;
1406                 goto out;
1407         }
1408
1409         ret = ubi_io_sync_erase(ubi, pnum, 0);
1410         if (ret < 0)
1411                 goto out;
1412
1413         ec = be64_to_cpu(ec_hdr->ec);
1414         ec += ret;
1415         if (ec > UBI_MAX_ERASECOUNTER) {
1416                 ret = -EINVAL;
1417                 goto out;
1418         }
1419
1420         ec_hdr->ec = cpu_to_be64(ec);
1421         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1422         if (ret < 0)
1423                 goto out;
1424
1425         ret = ec;
1426 out:
1427         kfree(ec_hdr);
1428         return ret;
1429 }
1430
1431 /**
1432  * invalidate_fastmap - destroys a fastmap.
1433  * @ubi: UBI device object
1434  *
1435  * This function ensures that upon next UBI attach a full scan
1436  * is issued. We need this if UBI is about to write a new fastmap
1437  * but is unable to do so. In this case we have two options:
1438  * a) Make sure that the current fastmap will not be usued upon
1439  * attach time and contine or b) fall back to RO mode to have the
1440  * current fastmap in a valid state.
1441  * Returns 0 on success, < 0 indicates an internal error.
1442  */
1443 static int invalidate_fastmap(struct ubi_device *ubi)
1444 {
1445         int ret;
1446         struct ubi_fastmap_layout *fm;
1447         struct ubi_wl_entry *e;
1448         struct ubi_vid_io_buf *vb = NULL;
1449         struct ubi_vid_hdr *vh;
1450
1451         if (!ubi->fm)
1452                 return 0;
1453
1454         ubi->fm = NULL;
1455
1456         ret = -ENOMEM;
1457         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1458         if (!fm)
1459                 goto out;
1460
1461         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1462         if (!vb)
1463                 goto out_free_fm;
1464
1465         vh = ubi_get_vid_hdr(vb);
1466
1467         ret = -ENOSPC;
1468         e = ubi_wl_get_fm_peb(ubi, 1);
1469         if (!e)
1470                 goto out_free_fm;
1471
1472         /*
1473          * Create fake fastmap such that UBI will fall back
1474          * to scanning mode.
1475          */
1476         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1477         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1478         if (ret < 0) {
1479                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1480                 goto out_free_fm;
1481         }
1482
1483         fm->used_blocks = 1;
1484         fm->e[0] = e;
1485
1486         ubi->fm = fm;
1487
1488 out:
1489         ubi_free_vid_buf(vb);
1490         return ret;
1491
1492 out_free_fm:
1493         kfree(fm);
1494         goto out;
1495 }
1496
1497 /**
1498  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1499  * WL sub-system.
1500  * @ubi: UBI device object
1501  * @fm: fastmap layout object
1502  */
1503 static void return_fm_pebs(struct ubi_device *ubi,
1504                            struct ubi_fastmap_layout *fm)
1505 {
1506         int i;
1507
1508         if (!fm)
1509                 return;
1510
1511         for (i = 0; i < fm->used_blocks; i++) {
1512                 if (fm->e[i]) {
1513                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1514                                           fm->to_be_tortured[i]);
1515                         fm->e[i] = NULL;
1516                 }
1517         }
1518 }
1519
1520 /**
1521  * ubi_update_fastmap - will be called by UBI if a volume changes or
1522  * a fastmap pool becomes full.
1523  * @ubi: UBI device object
1524  *
1525  * Returns 0 on success, < 0 indicates an internal error.
1526  */
1527 int ubi_update_fastmap(struct ubi_device *ubi)
1528 {
1529         int ret, i, j;
1530         struct ubi_fastmap_layout *new_fm, *old_fm;
1531         struct ubi_wl_entry *tmp_e;
1532
1533         down_write(&ubi->fm_protect);
1534         down_write(&ubi->work_sem);
1535         down_write(&ubi->fm_eba_sem);
1536
1537         ubi_refill_pools(ubi);
1538
1539         if (ubi->ro_mode || ubi->fm_disabled) {
1540                 up_write(&ubi->fm_eba_sem);
1541                 up_write(&ubi->work_sem);
1542                 up_write(&ubi->fm_protect);
1543                 return 0;
1544         }
1545
1546         ret = ubi_ensure_anchor_pebs(ubi);
1547         if (ret) {
1548                 up_write(&ubi->fm_eba_sem);
1549                 up_write(&ubi->work_sem);
1550                 up_write(&ubi->fm_protect);
1551                 return ret;
1552         }
1553
1554         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1555         if (!new_fm) {
1556                 up_write(&ubi->fm_eba_sem);
1557                 up_write(&ubi->work_sem);
1558                 up_write(&ubi->fm_protect);
1559                 return -ENOMEM;
1560         }
1561
1562         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1563         old_fm = ubi->fm;
1564         ubi->fm = NULL;
1565
1566         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1567                 ubi_err(ubi, "fastmap too large");
1568                 ret = -ENOSPC;
1569                 goto err;
1570         }
1571
1572         for (i = 1; i < new_fm->used_blocks; i++) {
1573                 spin_lock(&ubi->wl_lock);
1574                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1575                 spin_unlock(&ubi->wl_lock);
1576
1577                 if (!tmp_e) {
1578                         if (old_fm && old_fm->e[i]) {
1579                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1580                                 if (ret < 0) {
1581                                         ubi_err(ubi, "could not erase old fastmap PEB");
1582
1583                                         for (j = 1; j < i; j++) {
1584                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1585                                                                   j, 0);
1586                                                 new_fm->e[j] = NULL;
1587                                         }
1588                                         goto err;
1589                                 }
1590                                 new_fm->e[i] = old_fm->e[i];
1591                                 old_fm->e[i] = NULL;
1592                         } else {
1593                                 ubi_err(ubi, "could not get any free erase block");
1594
1595                                 for (j = 1; j < i; j++) {
1596                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1597                                         new_fm->e[j] = NULL;
1598                                 }
1599
1600                                 ret = -ENOSPC;
1601                                 goto err;
1602                         }
1603                 } else {
1604                         new_fm->e[i] = tmp_e;
1605
1606                         if (old_fm && old_fm->e[i]) {
1607                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1608                                                   old_fm->to_be_tortured[i]);
1609                                 old_fm->e[i] = NULL;
1610                         }
1611                 }
1612         }
1613
1614         /* Old fastmap is larger than the new one */
1615         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1616                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1617                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1618                                           old_fm->to_be_tortured[i]);
1619                         old_fm->e[i] = NULL;
1620                 }
1621         }
1622
1623         spin_lock(&ubi->wl_lock);
1624         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1625         spin_unlock(&ubi->wl_lock);
1626
1627         if (old_fm) {
1628                 /* no fresh anchor PEB was found, reuse the old one */
1629                 if (!tmp_e) {
1630                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1631                         if (ret < 0) {
1632                                 ubi_err(ubi, "could not erase old anchor PEB");
1633
1634                                 for (i = 1; i < new_fm->used_blocks; i++) {
1635                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1636                                                           i, 0);
1637                                         new_fm->e[i] = NULL;
1638                                 }
1639                                 goto err;
1640                         }
1641                         new_fm->e[0] = old_fm->e[0];
1642                         new_fm->e[0]->ec = ret;
1643                         old_fm->e[0] = NULL;
1644                 } else {
1645                         /* we've got a new anchor PEB, return the old one */
1646                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1647                                           old_fm->to_be_tortured[0]);
1648                         new_fm->e[0] = tmp_e;
1649                         old_fm->e[0] = NULL;
1650                 }
1651         } else {
1652                 if (!tmp_e) {
1653                         ubi_err(ubi, "could not find any anchor PEB");
1654
1655                         for (i = 1; i < new_fm->used_blocks; i++) {
1656                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1657                                 new_fm->e[i] = NULL;
1658                         }
1659
1660                         ret = -ENOSPC;
1661                         goto err;
1662                 }
1663                 new_fm->e[0] = tmp_e;
1664         }
1665
1666         ret = ubi_write_fastmap(ubi, new_fm);
1667
1668         if (ret)
1669                 goto err;
1670
1671 out_unlock:
1672         up_write(&ubi->fm_eba_sem);
1673         up_write(&ubi->work_sem);
1674         up_write(&ubi->fm_protect);
1675         kfree(old_fm);
1676         return ret;
1677
1678 err:
1679         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1680
1681         ret = invalidate_fastmap(ubi);
1682         if (ret < 0) {
1683                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1684                 ubi_ro_mode(ubi);
1685         } else {
1686                 return_fm_pebs(ubi, old_fm);
1687                 return_fm_pebs(ubi, new_fm);
1688                 ret = 0;
1689         }
1690
1691         kfree(new_fm);
1692         goto out_unlock;
1693 }