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 = &av->root.rb_node, *parent = NULL;
 218
 219         while (*p) {
 220                 parent = *p;
 221
 222                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 223                 if (aeb->lnum != tmp_aeb->lnum) {
 224                         if (aeb->lnum < tmp_aeb->lnum)
 225                                 p = &(*p)->rb_left;
 226                         else
 227                                 p = &(*p)->rb_right;
 228
 229                         continue;
 230                 } else
 231                         break;
 232         }
 233
 234         list_del(&aeb->u.list);
 235         av->leb_count++;
 236
 237         rb_link_node(&aeb->u.rb, parent, p);
 238         rb_insert_color(&aeb->u.rb, &av->root);
 239 }
 240
 241 /**
 242  * update_vol - inserts or updates a LEB which was found a pool.
 243  * @ubi: the UBI device object
 244  * @ai: attach info object
 245  * @av: the volume this LEB belongs to
 246  * @new_vh: the volume header derived from new_aeb
 247  * @new_aeb: the AEB to be examined
 248  *
 249  * Returns 0 on success, < 0 indicates an internal error.
 250  */
 251 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 252                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 253                       struct ubi_ainf_peb *new_aeb)
 254 {
 255         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 256         struct ubi_ainf_peb *aeb, *victim;
 257         int cmp_res;
 258
 259         while (*p) {
 260                 parent = *p;
 261                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 262
 263                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 264                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 265                                 p = &(*p)->rb_left;
 266                         else
 267                                 p = &(*p)->rb_right;
 268
 269                         continue;
 270                 }
 271
 272                 /* This case can happen if the fastmap gets written
 273                  * because of a volume change (creation, deletion, ..).
 274                  * Then a PEB can be within the persistent EBA and the pool.
 275                  */
 276                 if (aeb->pnum == new_aeb->pnum) {
 277                         ubi_assert(aeb->lnum == new_aeb->lnum);
 278                         ubi_free_aeb(ai, new_aeb);
 279
 280                         return 0;
 281                 }
 282
 283                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 284                 if (cmp_res < 0)
 285                         return cmp_res;
 286
 287                 /* new_aeb is newer */
 288                 if (cmp_res & 1) {
 289                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 290                         if (!victim)
 291                                 return -ENOMEM;
 292
 293                         list_add_tail(&victim->u.list, &ai->erase);
 294
 295                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 296                                 av->last_data_size =
 297                                         be32_to_cpu(new_vh->data_size);
 298
 299                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 300                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 301
 302                         aeb->ec = new_aeb->ec;
 303                         aeb->pnum = new_aeb->pnum;
 304                         aeb->copy_flag = new_vh->copy_flag;
 305                         aeb->scrub = new_aeb->scrub;
 306                         aeb->sqnum = new_aeb->sqnum;
 307                         ubi_free_aeb(ai, new_aeb);
 308
 309                 /* new_aeb is older */
 310                 } else {
 311                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 312                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 313                         list_add_tail(&new_aeb->u.list, &ai->erase);
 314                 }
 315
 316                 return 0;
 317         }
 318         /* This LEB is new, let's add it to the volume */
 319
 320         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 321                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 322                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 323         }
 324
 325         if (av->vol_type == UBI_STATIC_VOLUME)
 326                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 327
 328         av->leb_count++;
 329
 330         rb_link_node(&new_aeb->u.rb, parent, p);
 331         rb_insert_color(&new_aeb->u.rb, &av->root);
 332
 333         return 0;
 334 }
 335
 336 /**
 337  * process_pool_aeb - we found a non-empty PEB in a pool.
 338  * @ubi: UBI device object
 339  * @ai: attach info object
 340  * @new_vh: the volume header derived from new_aeb
 341  * @new_aeb: the AEB to be examined
 342  *
 343  * Returns 0 on success, < 0 indicates an internal error.
 344  */
 345 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 346                             struct ubi_vid_hdr *new_vh,
 347                             struct ubi_ainf_peb *new_aeb)
 348 {
 349         int vol_id = be32_to_cpu(new_vh->vol_id);
 350         struct ubi_ainf_volume *av;
 351
 352         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 353                 ubi_free_aeb(ai, new_aeb);
 354
 355                 return 0;
 356         }
 357
 358         /* Find the volume this SEB belongs to */
 359         av = ubi_find_av(ai, vol_id);
 360         if (!av) {
 361                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 362                 ubi_free_aeb(ai, new_aeb);
 363                 return UBI_BAD_FASTMAP;
 364         }
 365
 366         ubi_assert(vol_id == av->vol_id);
 367
 368         return update_vol(ubi, ai, av, new_vh, new_aeb);
 369 }
 370
 371 /**
 372  * unmap_peb - unmap a PEB.
 373  * If fastmap detects a free PEB in the pool it has to check whether
 374  * this PEB has been unmapped after writing the fastmap.
 375  *
 376  * @ai: UBI attach info object
 377  * @pnum: The PEB to be unmapped
 378  */
 379 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 380 {
 381         struct ubi_ainf_volume *av;
 382         struct rb_node *node, *node2;
 383         struct ubi_ainf_peb *aeb;
 384
 385         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 386                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 387                         if (aeb->pnum == pnum) {
 388                                 rb_erase(&aeb->u.rb, &av->root);
 389                                 av->leb_count--;
 390                                 ubi_free_aeb(ai, aeb);
 391                                 return;
 392                         }
 393                 }
 394         }
 395 }
 396
 397 /**
 398  * scan_pool - scans a pool for changed (no longer empty PEBs).
 399  * @ubi: UBI device object
 400  * @ai: attach info object
 401  * @pebs: an array of all PEB numbers in the to be scanned pool
 402  * @pool_size: size of the pool (number of entries in @pebs)
 403  * @max_sqnum: pointer to the maximal sequence number
 404  * @free: list of PEBs which are most likely free (and go into @ai->free)
 405  *
 406  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 407  * < 0 indicates an internal error.
 408  */
 409 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 410                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 411                      struct list_head *free)
 412 {
 413         struct ubi_vid_io_buf *vb;
 414         struct ubi_vid_hdr *vh;
 415         struct ubi_ec_hdr *ech;
 416         struct ubi_ainf_peb *new_aeb;
 417         int i, pnum, err, ret = 0;
 418
 419         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 420         if (!ech)
 421                 return -ENOMEM;
 422
 423         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 424         if (!vb) {
 425                 kfree(ech);
 426                 return -ENOMEM;
 427         }
 428
 429         vh = ubi_get_vid_hdr(vb);
 430
 431         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 432
 433         /*
 434          * Now scan all PEBs in the pool to find changes which have been made
 435          * after the creation of the fastmap
 436          */
 437         for (i = 0; i < pool_size; i++) {
 438                 int scrub = 0;
 439                 int image_seq;
 440
 441                 pnum = be32_to_cpu(pebs[i]);
 442
 443                 if (ubi_io_is_bad(ubi, pnum)) {
 444                         ubi_err(ubi, "bad PEB in fastmap pool!");
 445                         ret = UBI_BAD_FASTMAP;
 446                         goto out;
 447                 }
 448
 449                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 450                 if (err && err != UBI_IO_BITFLIPS) {
 451                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 452                                 pnum, err);
 453                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 454                         goto out;
 455                 } else if (err == UBI_IO_BITFLIPS)
 456                         scrub = 1;
 457
 458                 /*
 459                  * Older UBI implementations have image_seq set to zero, so
 460                  * we shouldn't fail if image_seq == 0.
 461                  */
 462                 image_seq = be32_to_cpu(ech->image_seq);
 463
 464                 if (image_seq && (image_seq != ubi->image_seq)) {
 465                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 466                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 467                         ret = UBI_BAD_FASTMAP;
 468                         goto out;
 469                 }
 470
 471                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 472                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 473                         unsigned long long ec = be64_to_cpu(ech->ec);
 474                         unmap_peb(ai, pnum);
 475                         dbg_bld("Adding PEB to free: %i", pnum);
 476
 477                         if (err == UBI_IO_FF_BITFLIPS)
 478                                 scrub = 1;
 479
 480                         add_aeb(ai, free, pnum, ec, scrub);
 481                         continue;
 482                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 483                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 484
 485                         if (err == UBI_IO_BITFLIPS)
 486                                 scrub = 1;
 487
 488                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 489                         if (!new_aeb) {
 490                                 ret = -ENOMEM;
 491                                 goto out;
 492                         }
 493
 494                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 495                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 496                         new_aeb->copy_flag = vh->copy_flag;
 497                         new_aeb->scrub = scrub;
 498
 499                         if (*max_sqnum < new_aeb->sqnum)
 500                                 *max_sqnum = new_aeb->sqnum;
 501
 502                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 503                         if (err) {
 504                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 505                                 goto out;
 506                         }
 507                 } else {
 508                         /* We are paranoid and fall back to scanning mode */
 509                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 510                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 511                         goto out;
 512                 }
 513
 514         }
 515
 516 out:
 517         ubi_free_vid_buf(vb);
 518         kfree(ech);
 519         return ret;
 520 }
 521
 522 /**
 523  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 524  * @ai: The UBI attach info object
 525  */
 526 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 527 {
 528         struct ubi_ainf_peb *aeb;
 529         struct ubi_ainf_volume *av;
 530         struct rb_node *rb1, *rb2;
 531         int n = 0;
 532
 533         list_for_each_entry(aeb, &ai->erase, u.list)
 534                 n++;
 535
 536         list_for_each_entry(aeb, &ai->free, u.list)
 537                 n++;
 538
 539         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 540                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 541                         n++;
 542
 543         return n;
 544 }
 545
 546 /**
 547  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 548  * @ubi: UBI device object
 549  * @ai: UBI attach info object
 550  * @fm: the fastmap to be attached
 551  *
 552  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 553  * < 0 indicates an internal error.
 554  */
 555 static int ubi_attach_fastmap(struct ubi_device *ubi,
 556                               struct ubi_attach_info *ai,
 557                               struct ubi_fastmap_layout *fm)
 558 {
 559         struct list_head used, free;
 560         struct ubi_ainf_volume *av;
 561         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 562         struct ubi_fm_sb *fmsb;
 563         struct ubi_fm_hdr *fmhdr;
 564         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 565         struct ubi_fm_ec *fmec;
 566         struct ubi_fm_volhdr *fmvhdr;
 567         struct ubi_fm_eba *fm_eba;
 568         int ret, i, j, pool_size, wl_pool_size;
 569         size_t fm_pos = 0, fm_size = ubi->fm_size;
 570         unsigned long long max_sqnum = 0;
 571         void *fm_raw = ubi->fm_buf;
 572
 573         INIT_LIST_HEAD(&used);
 574         INIT_LIST_HEAD(&free);
 575         ai->min_ec = UBI_MAX_ERASECOUNTER;
 576
 577         fmsb = (struct ubi_fm_sb *)(fm_raw);
 578         ai->max_sqnum = fmsb->sqnum;
 579         fm_pos += sizeof(struct ubi_fm_sb);
 580         if (fm_pos >= fm_size)
 581                 goto fail_bad;
 582
 583         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 584         fm_pos += sizeof(*fmhdr);
 585         if (fm_pos >= fm_size)
 586                 goto fail_bad;
 587
 588         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 589                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 590                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 591                 goto fail_bad;
 592         }
 593
 594         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 595         fm_pos += sizeof(*fmpl);
 596         if (fm_pos >= fm_size)
 597                 goto fail_bad;
 598         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 599                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 600                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 601                 goto fail_bad;
 602         }
 603
 604         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 605         fm_pos += sizeof(*fmpl_wl);
 606         if (fm_pos >= fm_size)
 607                 goto fail_bad;
 608         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 609                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 610                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 611                 goto fail_bad;
 612         }
 613
 614         pool_size = be16_to_cpu(fmpl->size);
 615         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 616         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 617         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 618
 619         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 620                 ubi_err(ubi, "bad pool size: %i", pool_size);
 621                 goto fail_bad;
 622         }
 623
 624         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 625                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 626                 goto fail_bad;
 627         }
 628
 629
 630         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 631             fm->max_pool_size < 0) {
 632                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 633                 goto fail_bad;
 634         }
 635
 636         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 637             fm->max_wl_pool_size < 0) {
 638                 ubi_err(ubi, "bad maximal WL pool size: %i",
 639                         fm->max_wl_pool_size);
 640                 goto fail_bad;
 641         }
 642
 643         /* read EC values from free list */
 644         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 645                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 646                 fm_pos += sizeof(*fmec);
 647                 if (fm_pos >= fm_size)
 648                         goto fail_bad;
 649
 650                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 651                         be32_to_cpu(fmec->ec), 0);
 652         }
 653
 654         /* read EC values from used list */
 655         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 656                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 657                 fm_pos += sizeof(*fmec);
 658                 if (fm_pos >= fm_size)
 659                         goto fail_bad;
 660
 661                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 662                         be32_to_cpu(fmec->ec), 0);
 663         }
 664
 665         /* read EC values from scrub list */
 666         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 667                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 668                 fm_pos += sizeof(*fmec);
 669                 if (fm_pos >= fm_size)
 670                         goto fail_bad;
 671
 672                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 673                         be32_to_cpu(fmec->ec), 1);
 674         }
 675
 676         /* read EC values from erase list */
 677         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 678                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 679                 fm_pos += sizeof(*fmec);
 680                 if (fm_pos >= fm_size)
 681                         goto fail_bad;
 682
 683                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 684                         be32_to_cpu(fmec->ec), 1);
 685         }
 686
 687         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 688         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 689
 690         /* Iterate over all volumes and read their EBA table */
 691         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 692                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 693                 fm_pos += sizeof(*fmvhdr);
 694                 if (fm_pos >= fm_size)
 695                         goto fail_bad;
 696
 697                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 698                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 699                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 700                         goto fail_bad;
 701                 }
 702
 703                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 704                              be32_to_cpu(fmvhdr->used_ebs),
 705                              be32_to_cpu(fmvhdr->data_pad),
 706                              fmvhdr->vol_type,
 707                              be32_to_cpu(fmvhdr->last_eb_bytes));
 708
 709                 if (IS_ERR(av)) {
 710                         if (PTR_ERR(av) == -EEXIST)
 711                                 ubi_err(ubi, "volume (ID %i) already exists",
 712                                         fmvhdr->vol_id);
 713
 714                         goto fail_bad;
 715                 }
 716
 717                 ai->vols_found++;
 718                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 719                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 720
 721                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 722                 fm_pos += sizeof(*fm_eba);
 723                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 724                 if (fm_pos >= fm_size)
 725                         goto fail_bad;
 726
 727                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 728                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 729                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 730                         goto fail_bad;
 731                 }
 732
 733                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 734                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 735
 736                         if (pnum < 0)
 737                                 continue;
 738
 739                         aeb = NULL;
 740                         list_for_each_entry(tmp_aeb, &used, u.list) {
 741                                 if (tmp_aeb->pnum == pnum) {
 742                                         aeb = tmp_aeb;
 743                                         break;
 744                                 }
 745                         }
 746
 747                         if (!aeb) {
 748                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 749                                 goto fail_bad;
 750                         }
 751
 752                         aeb->lnum = j;
 753
 754                         if (av->highest_lnum <= aeb->lnum)
 755                                 av->highest_lnum = aeb->lnum;
 756
 757                         assign_aeb_to_av(ai, aeb, av);
 758
 759                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 760                                 aeb->pnum, aeb->lnum, av->vol_id);
 761                 }
 762         }
 763
 764         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 765         if (ret)
 766                 goto fail;
 767
 768         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 769         if (ret)
 770                 goto fail;
 771
 772         if (max_sqnum > ai->max_sqnum)
 773                 ai->max_sqnum = max_sqnum;
 774
 775         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 776                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 777
 778         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 779                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 780
 781         ubi_assert(list_empty(&free));
 782
 783         /*
 784          * If fastmap is leaking PEBs (must not happen), raise a
 785          * fat warning and fall back to scanning mode.
 786          * We do this here because in ubi_wl_init() it's too late
 787          * and we cannot fall back to scanning.
 788          */
 789         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 790                     ai->bad_peb_count - fm->used_blocks))
 791                 goto fail_bad;
 792
 793         return 0;
 794
 795 fail_bad:
 796         ret = UBI_BAD_FASTMAP;
 797 fail:
 798         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 799                 list_del(&tmp_aeb->u.list);
 800                 ubi_free_aeb(ai, tmp_aeb);
 801         }
 802         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 803                 list_del(&tmp_aeb->u.list);
 804                 ubi_free_aeb(ai, tmp_aeb);
 805         }
 806
 807         return ret;
 808 }
 809
 810 /**
 811  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 812  * @ai: UBI attach info to be filled
 813  */
 814 static int find_fm_anchor(struct ubi_attach_info *ai)
 815 {
 816         int ret = -1;
 817         struct ubi_ainf_peb *aeb;
 818         unsigned long long max_sqnum = 0;
 819
 820         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 821                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 822                         max_sqnum = aeb->sqnum;
 823                         ret = aeb->pnum;
 824                 }
 825         }
 826
 827         return ret;
 828 }
 829
 830 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 831                                       struct ubi_ainf_peb *old)
 832 {
 833         struct ubi_ainf_peb *new;
 834
 835         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 836         if (!new)
 837                 return NULL;
 838
 839         new->vol_id = old->vol_id;
 840         new->sqnum = old->sqnum;
 841         new->lnum = old->lnum;
 842         new->scrub = old->scrub;
 843         new->copy_flag = old->copy_flag;
 844
 845         return new;
 846 }
 847
 848 /**
 849  * ubi_scan_fastmap - scan the fastmap.
 850  * @ubi: UBI device object
 851  * @ai: UBI attach info to be filled
 852  * @scan_ai: UBI attach info from the first 64 PEBs,
 853  *           used to find the most recent Fastmap data structure
 854  *
 855  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 856  * UBI_BAD_FASTMAP if one was found but is not usable.
 857  * < 0 indicates an internal error.
 858  */
 859 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 860                      struct ubi_attach_info *scan_ai)
 861 {
 862         struct ubi_fm_sb *fmsb, *fmsb2;
 863         struct ubi_vid_io_buf *vb;
 864         struct ubi_vid_hdr *vh;
 865         struct ubi_ec_hdr *ech;
 866         struct ubi_fastmap_layout *fm;
 867         struct ubi_ainf_peb *aeb;
 868         int i, used_blocks, pnum, fm_anchor, ret = 0;
 869         size_t fm_size;
 870         __be32 crc, tmp_crc;
 871         unsigned long long sqnum = 0;
 872
 873         fm_anchor = find_fm_anchor(scan_ai);
 874         if (fm_anchor < 0)
 875                 return UBI_NO_FASTMAP;
 876
 877         /* Copy all (possible) fastmap blocks into our new attach structure. */
 878         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 879                 struct ubi_ainf_peb *new;
 880
 881                 new = clone_aeb(ai, aeb);
 882                 if (!new)
 883                         return -ENOMEM;
 884
 885                 list_add(&new->u.list, &ai->fastmap);
 886         }
 887
 888         down_write(&ubi->fm_protect);
 889         memset(ubi->fm_buf, 0, ubi->fm_size);
 890
 891         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 892         if (!fmsb) {
 893                 ret = -ENOMEM;
 894                 goto out;
 895         }
 896
 897         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 898         if (!fm) {
 899                 ret = -ENOMEM;
 900                 kfree(fmsb);
 901                 goto out;
 902         }
 903
 904         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 905         if (ret && ret != UBI_IO_BITFLIPS)
 906                 goto free_fm_sb;
 907         else if (ret == UBI_IO_BITFLIPS)
 908                 fm->to_be_tortured[0] = 1;
 909
 910         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 911                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 912                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 913                 ret = UBI_BAD_FASTMAP;
 914                 goto free_fm_sb;
 915         }
 916
 917         if (fmsb->version != UBI_FM_FMT_VERSION) {
 918                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 919                         fmsb->version, UBI_FM_FMT_VERSION);
 920                 ret = UBI_BAD_FASTMAP;
 921                 goto free_fm_sb;
 922         }
 923
 924         used_blocks = be32_to_cpu(fmsb->used_blocks);
 925         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 926                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 927                         used_blocks);
 928                 ret = UBI_BAD_FASTMAP;
 929                 goto free_fm_sb;
 930         }
 931
 932         fm_size = ubi->leb_size * used_blocks;
 933         if (fm_size != ubi->fm_size) {
 934                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 935                         fm_size, ubi->fm_size);
 936                 ret = UBI_BAD_FASTMAP;
 937                 goto free_fm_sb;
 938         }
 939
 940         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 941         if (!ech) {
 942                 ret = -ENOMEM;
 943                 goto free_fm_sb;
 944         }
 945
 946         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 947         if (!vb) {
 948                 ret = -ENOMEM;
 949                 goto free_hdr;
 950         }
 951
 952         vh = ubi_get_vid_hdr(vb);
 953
 954         for (i = 0; i < used_blocks; i++) {
 955                 int image_seq;
 956
 957                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 958
 959                 if (ubi_io_is_bad(ubi, pnum)) {
 960                         ret = UBI_BAD_FASTMAP;
 961                         goto free_hdr;
 962                 }
 963
 964                 if (i == 0 && pnum != fm_anchor) {
 965                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 966                                 pnum, fm_anchor);
 967                         ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 }
 970
 971                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 972                 if (ret && ret != UBI_IO_BITFLIPS) {
 973                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 974                                 i, pnum);
 975                         if (ret > 0)
 976                                 ret = UBI_BAD_FASTMAP;
 977                         goto free_hdr;
 978                 } else if (ret == UBI_IO_BITFLIPS)
 979                         fm->to_be_tortured[i] = 1;
 980
 981                 image_seq = be32_to_cpu(ech->image_seq);
 982                 if (!ubi->image_seq)
 983                         ubi->image_seq = image_seq;
 984
 985                 /*
 986                  * Older UBI implementations have image_seq set to zero, so
 987                  * we shouldn't fail if image_seq == 0.
 988                  */
 989                 if (image_seq && (image_seq != ubi->image_seq)) {
 990                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 991                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 992                         ret = UBI_BAD_FASTMAP;
 993                         goto free_hdr;
 994                 }
 995
 996                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 997                 if (ret && ret != UBI_IO_BITFLIPS) {
 998                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 999                                 i, pnum);
1000                         goto free_hdr;
1001                 }
1002
1003                 if (i == 0) {
1004                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1005                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1006                                         be32_to_cpu(vh->vol_id),
1007                                         UBI_FM_SB_VOLUME_ID);
1008                                 ret = UBI_BAD_FASTMAP;
1009                                 goto free_hdr;
1010                         }
1011                 } else {
1012                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1013                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1014                                         be32_to_cpu(vh->vol_id),
1015                                         UBI_FM_DATA_VOLUME_ID);
1016                                 ret = UBI_BAD_FASTMAP;
1017                                 goto free_hdr;
1018                         }
1019                 }
1020
1021                 if (sqnum < be64_to_cpu(vh->sqnum))
1022                         sqnum = be64_to_cpu(vh->sqnum);
1023
1024                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1025                                        pnum, 0, ubi->leb_size);
1026                 if (ret && ret != UBI_IO_BITFLIPS) {
1027                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1028                                 "err: %i)", i, pnum, ret);
1029                         goto free_hdr;
1030                 }
1031         }
1032
1033         kfree(fmsb);
1034         fmsb = NULL;
1035
1036         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1037         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1038         fmsb2->data_crc = 0;
1039         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1040         if (crc != tmp_crc) {
1041                 ubi_err(ubi, "fastmap data CRC is invalid");
1042                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1043                         tmp_crc, crc);
1044                 ret = UBI_BAD_FASTMAP;
1045                 goto free_hdr;
1046         }
1047
1048         fmsb2->sqnum = sqnum;
1049
1050         fm->used_blocks = used_blocks;
1051
1052         ret = ubi_attach_fastmap(ubi, ai, fm);
1053         if (ret) {
1054                 if (ret > 0)
1055                         ret = UBI_BAD_FASTMAP;
1056                 goto free_hdr;
1057         }
1058
1059         for (i = 0; i < used_blocks; i++) {
1060                 struct ubi_wl_entry *e;
1061
1062                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1063                 if (!e) {
1064                         while (i--)
1065                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1066
1067                         ret = -ENOMEM;
1068                         goto free_hdr;
1069                 }
1070
1071                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1072                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1073                 fm->e[i] = e;
1074         }
1075
1076         ubi->fm = fm;
1077         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1078         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1079         ubi_msg(ubi, "attached by fastmap");
1080         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1081         ubi_msg(ubi, "fastmap WL pool size: %d",
1082                 ubi->fm_wl_pool.max_size);
1083         ubi->fm_disabled = 0;
1084         ubi->fast_attach = 1;
1085
1086         ubi_free_vid_buf(vb);
1087         kfree(ech);
1088 out:
1089         up_write(&ubi->fm_protect);
1090         if (ret == UBI_BAD_FASTMAP)
1091                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1092         return ret;
1093
1094 free_hdr:
1095         ubi_free_vid_buf(vb);
1096         kfree(ech);
1097 free_fm_sb:
1098         kfree(fmsb);
1099         kfree(fm);
1100         goto out;
1101 }
1102
1103 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1104 {
1105         struct ubi_device *ubi = vol->ubi;
1106
1107         if (!ubi->fast_attach)
1108                 return 0;
1109
1110         vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
1111                                 GFP_KERNEL);
1112         if (!vol->checkmap)
1113                 return -ENOMEM;
1114
1115         return 0;
1116 }
1117
1118 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1119 {
1120         kfree(vol->checkmap);
1121 }
1122
1123 /**
1124  * ubi_write_fastmap - writes a fastmap.
1125  * @ubi: UBI device object
1126  * @new_fm: the to be written fastmap
1127  *
1128  * Returns 0 on success, < 0 indicates an internal error.
1129  */
1130 static int ubi_write_fastmap(struct ubi_device *ubi,
1131                              struct ubi_fastmap_layout *new_fm)
1132 {
1133         size_t fm_pos = 0;
1134         void *fm_raw;
1135         struct ubi_fm_sb *fmsb;
1136         struct ubi_fm_hdr *fmh;
1137         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1138         struct ubi_fm_ec *fec;
1139         struct ubi_fm_volhdr *fvh;
1140         struct ubi_fm_eba *feba;
1141         struct ubi_wl_entry *wl_e;
1142         struct ubi_volume *vol;
1143         struct ubi_vid_io_buf *avbuf, *dvbuf;
1144         struct ubi_vid_hdr *avhdr, *dvhdr;
1145         struct ubi_work *ubi_wrk;
1146         struct rb_node *tmp_rb;
1147         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1148         int scrub_peb_count, erase_peb_count;
1149         unsigned long *seen_pebs;
1150
1151         fm_raw = ubi->fm_buf;
1152         memset(ubi->fm_buf, 0, ubi->fm_size);
1153
1154         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1155         if (!avbuf) {
1156                 ret = -ENOMEM;
1157                 goto out;
1158         }
1159
1160         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1161         if (!dvbuf) {
1162                 ret = -ENOMEM;
1163                 goto out_free_avbuf;
1164         }
1165
1166         avhdr = ubi_get_vid_hdr(avbuf);
1167         dvhdr = ubi_get_vid_hdr(dvbuf);
1168
1169         seen_pebs = init_seen(ubi);
1170         if (IS_ERR(seen_pebs)) {
1171                 ret = PTR_ERR(seen_pebs);
1172                 goto out_free_dvbuf;
1173         }
1174
1175         spin_lock(&ubi->volumes_lock);
1176         spin_lock(&ubi->wl_lock);
1177
1178         fmsb = (struct ubi_fm_sb *)fm_raw;
1179         fm_pos += sizeof(*fmsb);
1180         ubi_assert(fm_pos <= ubi->fm_size);
1181
1182         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1183         fm_pos += sizeof(*fmh);
1184         ubi_assert(fm_pos <= ubi->fm_size);
1185
1186         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1187         fmsb->version = UBI_FM_FMT_VERSION;
1188         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1189         /* the max sqnum will be filled in while *reading* the fastmap */
1190         fmsb->sqnum = 0;
1191
1192         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1193         free_peb_count = 0;
1194         used_peb_count = 0;
1195         scrub_peb_count = 0;
1196         erase_peb_count = 0;
1197         vol_count = 0;
1198
1199         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1200         fm_pos += sizeof(*fmpl);
1201         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1202         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1203         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1204
1205         for (i = 0; i < ubi->fm_pool.size; i++) {
1206                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1207                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1208         }
1209
1210         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1211         fm_pos += sizeof(*fmpl_wl);
1212         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1213         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1214         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1215
1216         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1217                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1218                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1219         }
1220
1221         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1222                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1223
1224                 fec->pnum = cpu_to_be32(wl_e->pnum);
1225                 set_seen(ubi, wl_e->pnum, seen_pebs);
1226                 fec->ec = cpu_to_be32(wl_e->ec);
1227
1228                 free_peb_count++;
1229                 fm_pos += sizeof(*fec);
1230                 ubi_assert(fm_pos <= ubi->fm_size);
1231         }
1232         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1233
1234         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1235                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1236
1237                 fec->pnum = cpu_to_be32(wl_e->pnum);
1238                 set_seen(ubi, wl_e->pnum, seen_pebs);
1239                 fec->ec = cpu_to_be32(wl_e->ec);
1240
1241                 used_peb_count++;
1242                 fm_pos += sizeof(*fec);
1243                 ubi_assert(fm_pos <= ubi->fm_size);
1244         }
1245
1246         ubi_for_each_protected_peb(ubi, i, wl_e) {
1247                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1248
1249                 fec->pnum = cpu_to_be32(wl_e->pnum);
1250                 set_seen(ubi, wl_e->pnum, seen_pebs);
1251                 fec->ec = cpu_to_be32(wl_e->ec);
1252
1253                 used_peb_count++;
1254                 fm_pos += sizeof(*fec);
1255                 ubi_assert(fm_pos <= ubi->fm_size);
1256         }
1257         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1258
1259         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1260                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1261
1262                 fec->pnum = cpu_to_be32(wl_e->pnum);
1263                 set_seen(ubi, wl_e->pnum, seen_pebs);
1264                 fec->ec = cpu_to_be32(wl_e->ec);
1265
1266                 scrub_peb_count++;
1267                 fm_pos += sizeof(*fec);
1268                 ubi_assert(fm_pos <= ubi->fm_size);
1269         }
1270         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1271
1272
1273         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1274                 if (ubi_is_erase_work(ubi_wrk)) {
1275                         wl_e = ubi_wrk->e;
1276                         ubi_assert(wl_e);
1277
1278                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1279
1280                         fec->pnum = cpu_to_be32(wl_e->pnum);
1281                         set_seen(ubi, wl_e->pnum, seen_pebs);
1282                         fec->ec = cpu_to_be32(wl_e->ec);
1283
1284                         erase_peb_count++;
1285                         fm_pos += sizeof(*fec);
1286                         ubi_assert(fm_pos <= ubi->fm_size);
1287                 }
1288         }
1289         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1290
1291         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1292                 vol = ubi->volumes[i];
1293
1294                 if (!vol)
1295                         continue;
1296
1297                 vol_count++;
1298
1299                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1300                 fm_pos += sizeof(*fvh);
1301                 ubi_assert(fm_pos <= ubi->fm_size);
1302
1303                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1304                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1305                 fvh->vol_type = vol->vol_type;
1306                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1307                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1308                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1309
1310                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1311                         vol->vol_type == UBI_STATIC_VOLUME);
1312
1313                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1314                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1315                 ubi_assert(fm_pos <= ubi->fm_size);
1316
1317                 for (j = 0; j < vol->reserved_pebs; j++) {
1318                         struct ubi_eba_leb_desc ldesc;
1319
1320                         ubi_eba_get_ldesc(vol, j, &ldesc);
1321                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1322                 }
1323
1324                 feba->reserved_pebs = cpu_to_be32(j);
1325                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1326         }
1327         fmh->vol_count = cpu_to_be32(vol_count);
1328         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1329
1330         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1331         avhdr->lnum = 0;
1332
1333         spin_unlock(&ubi->wl_lock);
1334         spin_unlock(&ubi->volumes_lock);
1335
1336         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1337         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1338         if (ret) {
1339                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1340                 goto out_free_seen;
1341         }
1342
1343         for (i = 0; i < new_fm->used_blocks; i++) {
1344                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1345                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1346                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1347         }
1348
1349         fmsb->data_crc = 0;
1350         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1351                                            ubi->fm_size));
1352
1353         for (i = 1; i < new_fm->used_blocks; i++) {
1354                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1355                 dvhdr->lnum = cpu_to_be32(i);
1356                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1357                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1358                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1359                 if (ret) {
1360                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1361                                 new_fm->e[i]->pnum);
1362                         goto out_free_seen;
1363                 }
1364         }
1365
1366         for (i = 0; i < new_fm->used_blocks; i++) {
1367                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1368                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1369                 if (ret) {
1370                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1371                                 new_fm->e[i]->pnum);
1372                         goto out_free_seen;
1373                 }
1374         }
1375
1376         ubi_assert(new_fm);
1377         ubi->fm = new_fm;
1378
1379         ret = self_check_seen(ubi, seen_pebs);
1380         dbg_bld("fastmap written!");
1381
1382 out_free_seen:
1383         free_seen(seen_pebs);
1384 out_free_dvbuf:
1385         ubi_free_vid_buf(dvbuf);
1386 out_free_avbuf:
1387         ubi_free_vid_buf(avbuf);
1388
1389 out:
1390         return ret;
1391 }
1392
1393 /**
1394  * erase_block - Manually erase a PEB.
1395  * @ubi: UBI device object
1396  * @pnum: PEB to be erased
1397  *
1398  * Returns the new EC value on success, < 0 indicates an internal error.
1399  */
1400 static int erase_block(struct ubi_device *ubi, int pnum)
1401 {
1402         int ret;
1403         struct ubi_ec_hdr *ec_hdr;
1404         long long ec;
1405
1406         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1407         if (!ec_hdr)
1408                 return -ENOMEM;
1409
1410         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1411         if (ret < 0)
1412                 goto out;
1413         else if (ret && ret != UBI_IO_BITFLIPS) {
1414                 ret = -EINVAL;
1415                 goto out;
1416         }
1417
1418         ret = ubi_io_sync_erase(ubi, pnum, 0);
1419         if (ret < 0)
1420                 goto out;
1421
1422         ec = be64_to_cpu(ec_hdr->ec);
1423         ec += ret;
1424         if (ec > UBI_MAX_ERASECOUNTER) {
1425                 ret = -EINVAL;
1426                 goto out;
1427         }
1428
1429         ec_hdr->ec = cpu_to_be64(ec);
1430         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1431         if (ret < 0)
1432                 goto out;
1433
1434         ret = ec;
1435 out:
1436         kfree(ec_hdr);
1437         return ret;
1438 }
1439
1440 /**
1441  * invalidate_fastmap - destroys a fastmap.
1442  * @ubi: UBI device object
1443  *
1444  * This function ensures that upon next UBI attach a full scan
1445  * is issued. We need this if UBI is about to write a new fastmap
1446  * but is unable to do so. In this case we have two options:
1447  * a) Make sure that the current fastmap will not be usued upon
1448  * attach time and contine or b) fall back to RO mode to have the
1449  * current fastmap in a valid state.
1450  * Returns 0 on success, < 0 indicates an internal error.
1451  */
1452 static int invalidate_fastmap(struct ubi_device *ubi)
1453 {
1454         int ret;
1455         struct ubi_fastmap_layout *fm;
1456         struct ubi_wl_entry *e;
1457         struct ubi_vid_io_buf *vb = NULL;
1458         struct ubi_vid_hdr *vh;
1459
1460         if (!ubi->fm)
1461                 return 0;
1462
1463         ubi->fm = NULL;
1464
1465         ret = -ENOMEM;
1466         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1467         if (!fm)
1468                 goto out;
1469
1470         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1471         if (!vb)
1472                 goto out_free_fm;
1473
1474         vh = ubi_get_vid_hdr(vb);
1475
1476         ret = -ENOSPC;
1477         e = ubi_wl_get_fm_peb(ubi, 1);
1478         if (!e)
1479                 goto out_free_fm;
1480
1481         /*
1482          * Create fake fastmap such that UBI will fall back
1483          * to scanning mode.
1484          */
1485         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1486         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1487         if (ret < 0) {
1488                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1489                 goto out_free_fm;
1490         }
1491
1492         fm->used_blocks = 1;
1493         fm->e[0] = e;
1494
1495         ubi->fm = fm;
1496
1497 out:
1498         ubi_free_vid_buf(vb);
1499         return ret;
1500
1501 out_free_fm:
1502         kfree(fm);
1503         goto out;
1504 }
1505
1506 /**
1507  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1508  * WL sub-system.
1509  * @ubi: UBI device object
1510  * @fm: fastmap layout object
1511  */
1512 static void return_fm_pebs(struct ubi_device *ubi,
1513                            struct ubi_fastmap_layout *fm)
1514 {
1515         int i;
1516
1517         if (!fm)
1518                 return;
1519
1520         for (i = 0; i < fm->used_blocks; i++) {
1521                 if (fm->e[i]) {
1522                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1523                                           fm->to_be_tortured[i]);
1524                         fm->e[i] = NULL;
1525                 }
1526         }
1527 }
1528
1529 /**
1530  * ubi_update_fastmap - will be called by UBI if a volume changes or
1531  * a fastmap pool becomes full.
1532  * @ubi: UBI device object
1533  *
1534  * Returns 0 on success, < 0 indicates an internal error.
1535  */
1536 int ubi_update_fastmap(struct ubi_device *ubi)
1537 {
1538         int ret, i, j;
1539         struct ubi_fastmap_layout *new_fm, *old_fm;
1540         struct ubi_wl_entry *tmp_e;
1541
1542         down_write(&ubi->fm_protect);
1543         down_write(&ubi->work_sem);
1544         down_write(&ubi->fm_eba_sem);
1545
1546         ubi_refill_pools(ubi);
1547
1548         if (ubi->ro_mode || ubi->fm_disabled) {
1549                 up_write(&ubi->fm_eba_sem);
1550                 up_write(&ubi->work_sem);
1551                 up_write(&ubi->fm_protect);
1552                 return 0;
1553         }
1554
1555         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1556         if (!new_fm) {
1557                 up_write(&ubi->fm_eba_sem);
1558                 up_write(&ubi->work_sem);
1559                 up_write(&ubi->fm_protect);
1560                 return -ENOMEM;
1561         }
1562
1563         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1564         old_fm = ubi->fm;
1565         ubi->fm = NULL;
1566
1567         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1568                 ubi_err(ubi, "fastmap too large");
1569                 ret = -ENOSPC;
1570                 goto err;
1571         }
1572
1573         for (i = 1; i < new_fm->used_blocks; i++) {
1574                 spin_lock(&ubi->wl_lock);
1575                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1576                 spin_unlock(&ubi->wl_lock);
1577
1578                 if (!tmp_e) {
1579                         if (old_fm && old_fm->e[i]) {
1580                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1581                                 if (ret < 0) {
1582                                         ubi_err(ubi, "could not erase old fastmap PEB");
1583
1584                                         for (j = 1; j < i; j++) {
1585                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1586                                                                   j, 0);
1587                                                 new_fm->e[j] = NULL;
1588                                         }
1589                                         goto err;
1590                                 }
1591                                 new_fm->e[i] = old_fm->e[i];
1592                                 old_fm->e[i] = NULL;
1593                         } else {
1594                                 ubi_err(ubi, "could not get any free erase block");
1595
1596                                 for (j = 1; j < i; j++) {
1597                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1598                                         new_fm->e[j] = NULL;
1599                                 }
1600
1601                                 ret = -ENOSPC;
1602                                 goto err;
1603                         }
1604                 } else {
1605                         new_fm->e[i] = tmp_e;
1606
1607                         if (old_fm && old_fm->e[i]) {
1608                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1609                                                   old_fm->to_be_tortured[i]);
1610                                 old_fm->e[i] = NULL;
1611                         }
1612                 }
1613         }
1614
1615         /* Old fastmap is larger than the new one */
1616         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1617                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1618                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1619                                           old_fm->to_be_tortured[i]);
1620                         old_fm->e[i] = NULL;
1621                 }
1622         }
1623
1624         spin_lock(&ubi->wl_lock);
1625         tmp_e = ubi->fm_anchor;
1626         ubi->fm_anchor = NULL;
1627         spin_unlock(&ubi->wl_lock);
1628
1629         if (old_fm) {
1630                 /* no fresh anchor PEB was found, reuse the old one */
1631                 if (!tmp_e) {
1632                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1633                         if (ret < 0) {
1634                                 ubi_err(ubi, "could not erase old anchor PEB");
1635
1636                                 for (i = 1; i < new_fm->used_blocks; i++) {
1637                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1638                                                           i, 0);
1639                                         new_fm->e[i] = NULL;
1640                                 }
1641                                 goto err;
1642                         }
1643                         new_fm->e[0] = old_fm->e[0];
1644                         new_fm->e[0]->ec = ret;
1645                         old_fm->e[0] = NULL;
1646                 } else {
1647                         /* we've got a new anchor PEB, return the old one */
1648                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1649                                           old_fm->to_be_tortured[0]);
1650                         new_fm->e[0] = tmp_e;
1651                         old_fm->e[0] = NULL;
1652                 }
1653         } else {
1654                 if (!tmp_e) {
1655                         ubi_err(ubi, "could not find any anchor PEB");
1656
1657                         for (i = 1; i < new_fm->used_blocks; i++) {
1658                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1659                                 new_fm->e[i] = NULL;
1660                         }
1661
1662                         ret = -ENOSPC;
1663                         goto err;
1664                 }
1665                 new_fm->e[0] = tmp_e;
1666         }
1667
1668         ret = ubi_write_fastmap(ubi, new_fm);
1669
1670         if (ret)
1671                 goto err;
1672
1673 out_unlock:
1674         up_write(&ubi->fm_eba_sem);
1675         up_write(&ubi->work_sem);
1676         up_write(&ubi->fm_protect);
1677         kfree(old_fm);
1678
1679         ubi_ensure_anchor_pebs(ubi);
1680
1681         return ret;
1682
1683 err:
1684         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1685
1686         ret = invalidate_fastmap(ubi);
1687         if (ret < 0) {
1688                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1689                 ubi_ro_mode(ubi);
1690         } else {
1691                 return_fm_pebs(ubi, old_fm);
1692                 return_fm_pebs(ubi, new_fm);
1693                 ret = 0;
1694         }
1695
1696         kfree(new_fm);
1697         goto out_unlock;
1698 }