drivers/mtd/ubi/fastmap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012 Linutronix GmbH
   4  * Copyright (c) 2014 sigma star gmbh
   5  * Author: Richard Weinberger <richard@nod.at>
   6  */
   7
   8 #include <linux/crc32.h>
   9 #include <linux/bitmap.h>
  10 #include "ubi.h"
  11
  12 /**
  13  * init_seen - allocate memory for used for debugging.
  14  * @ubi: UBI device description object
  15  */
  16 static inline unsigned long *init_seen(struct ubi_device *ubi)
  17 {
  18         unsigned long *ret;
  19
  20         if (!ubi_dbg_chk_fastmap(ubi))
  21                 return NULL;
  22
  23         ret = bitmap_zalloc(ubi->peb_count, GFP_KERNEL);
  24         if (!ret)
  25                 return ERR_PTR(-ENOMEM);
  26
  27         return ret;
  28 }
  29
  30 /**
  31  * free_seen - free the seen logic integer array.
  32  * @seen: integer array of @ubi->peb_count size
  33  */
  34 static inline void free_seen(unsigned long *seen)
  35 {
  36         bitmap_free(seen);
  37 }
  38
  39 /**
  40  * set_seen - mark a PEB as seen.
  41  * @ubi: UBI device description object
  42  * @pnum: The PEB to be makred as seen
  43  * @seen: integer array of @ubi->peb_count size
  44  */
  45 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  46 {
  47         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  48                 return;
  49
  50         set_bit(pnum, seen);
  51 }
  52
  53 /**
  54  * self_check_seen - check whether all PEB have been seen by fastmap.
  55  * @ubi: UBI device description object
  56  * @seen: integer array of @ubi->peb_count size
  57  */
  58 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  59 {
  60         int pnum, ret = 0;
  61
  62         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  63                 return 0;
  64
  65         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  66                 if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  67                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  68                         ret = -EINVAL;
  69                 }
  70         }
  71
  72         return ret;
  73 }
  74
  75 /**
  76  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  77  * @ubi: UBI device description object
  78  */
  79 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  80 {
  81         size_t size;
  82
  83         size = sizeof(struct ubi_fm_sb) +
  84                 sizeof(struct ubi_fm_hdr) +
  85                 sizeof(struct ubi_fm_scan_pool) +
  86                 sizeof(struct ubi_fm_scan_pool) +
  87                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  88                 (sizeof(struct ubi_fm_eba) +
  89                 (ubi->peb_count * sizeof(__be32))) +
  90                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  91         return roundup(size, ubi->leb_size);
  92 }
  93
  94
  95 /**
  96  * new_fm_vbuf() - allocate a new volume header for fastmap usage.
  97  * @ubi: UBI device description object
  98  * @vol_id: the VID of the new header
  99  *
 100  * Returns a new struct ubi_vid_hdr on success.
 101  * NULL indicates out of memory.
 102  */
 103 static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 104 {
 105         struct ubi_vid_io_buf *new;
 106         struct ubi_vid_hdr *vh;
 107
 108         new = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 109         if (!new)
 110                 goto out;
 111
 112         vh = ubi_get_vid_hdr(new);
 113         vh->vol_type = UBI_VID_DYNAMIC;
 114         vh->vol_id = cpu_to_be32(vol_id);
 115
 116         /* UBI implementations without fastmap support have to delete the
 117          * fastmap.
 118          */
 119         vh->compat = UBI_COMPAT_DELETE;
 120
 121 out:
 122         return new;
 123 }
 124
 125 /**
 126  * add_aeb - create and add a attach erase block to a given list.
 127  * @ai: UBI attach info object
 128  * @list: the target list
 129  * @pnum: PEB number of the new attach erase block
 130  * @ec: erease counter of the new LEB
 131  * @scrub: scrub this PEB after attaching
 132  *
 133  * Returns 0 on success, < 0 indicates an internal error.
 134  */
 135 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 136                    int pnum, int ec, int scrub)
 137 {
 138         struct ubi_ainf_peb *aeb;
 139
 140         aeb = ubi_alloc_aeb(ai, pnum, ec);
 141         if (!aeb)
 142                 return -ENOMEM;
 143
 144         aeb->lnum = -1;
 145         aeb->scrub = scrub;
 146         aeb->copy_flag = aeb->sqnum = 0;
 147
 148         ai->ec_sum += aeb->ec;
 149         ai->ec_count++;
 150
 151         if (ai->max_ec < aeb->ec)
 152                 ai->max_ec = aeb->ec;
 153
 154         if (ai->min_ec > aeb->ec)
 155                 ai->min_ec = aeb->ec;
 156
 157         list_add_tail(&aeb->u.list, list);
 158
 159         return 0;
 160 }
 161
 162 /**
 163  * add_vol - create and add a new volume to ubi_attach_info.
 164  * @ai: ubi_attach_info object
 165  * @vol_id: VID of the new volume
 166  * @used_ebs: number of used EBS
 167  * @data_pad: data padding value of the new volume
 168  * @vol_type: volume type
 169  * @last_eb_bytes: number of bytes in the last LEB
 170  *
 171  * Returns the new struct ubi_ainf_volume on success.
 172  * NULL indicates an error.
 173  */
 174 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 175                                        int used_ebs, int data_pad, u8 vol_type,
 176                                        int last_eb_bytes)
 177 {
 178         struct ubi_ainf_volume *av;
 179
 180         av = ubi_add_av(ai, vol_id);
 181         if (IS_ERR(av))
 182                 return av;
 183
 184         av->data_pad = data_pad;
 185         av->last_data_size = last_eb_bytes;
 186         av->compat = 0;
 187         av->vol_type = vol_type;
 188         if (av->vol_type == UBI_STATIC_VOLUME)
 189                 av->used_ebs = used_ebs;
 190
 191         dbg_bld("found volume (ID %i)", vol_id);
 192         return av;
 193 }
 194
 195 /**
 196  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 197  * from it's original list.
 198  * @ai: ubi_attach_info object
 199  * @aeb: the to be assigned SEB
 200  * @av: target scan volume
 201  */
 202 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 203                              struct ubi_ainf_peb *aeb,
 204                              struct ubi_ainf_volume *av)
 205 {
 206         struct ubi_ainf_peb *tmp_aeb;
 207         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 208
 209         while (*p) {
 210                 parent = *p;
 211
 212                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 213                 if (aeb->lnum != tmp_aeb->lnum) {
 214                         if (aeb->lnum < tmp_aeb->lnum)
 215                                 p = &(*p)->rb_left;
 216                         else
 217                                 p = &(*p)->rb_right;
 218
 219                         continue;
 220                 } else
 221                         break;
 222         }
 223
 224         list_del(&aeb->u.list);
 225         av->leb_count++;
 226
 227         rb_link_node(&aeb->u.rb, parent, p);
 228         rb_insert_color(&aeb->u.rb, &av->root);
 229 }
 230
 231 /**
 232  * update_vol - inserts or updates a LEB which was found a pool.
 233  * @ubi: the UBI device object
 234  * @ai: attach info object
 235  * @av: the volume this LEB belongs to
 236  * @new_vh: the volume header derived from new_aeb
 237  * @new_aeb: the AEB to be examined
 238  *
 239  * Returns 0 on success, < 0 indicates an internal error.
 240  */
 241 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 242                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 243                       struct ubi_ainf_peb *new_aeb)
 244 {
 245         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 246         struct ubi_ainf_peb *aeb, *victim;
 247         int cmp_res;
 248
 249         while (*p) {
 250                 parent = *p;
 251                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 252
 253                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 254                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 255                                 p = &(*p)->rb_left;
 256                         else
 257                                 p = &(*p)->rb_right;
 258
 259                         continue;
 260                 }
 261
 262                 /* This case can happen if the fastmap gets written
 263                  * because of a volume change (creation, deletion, ..).
 264                  * Then a PEB can be within the persistent EBA and the pool.
 265                  */
 266                 if (aeb->pnum == new_aeb->pnum) {
 267                         ubi_assert(aeb->lnum == new_aeb->lnum);
 268                         ubi_free_aeb(ai, new_aeb);
 269
 270                         return 0;
 271                 }
 272
 273                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 274                 if (cmp_res < 0)
 275                         return cmp_res;
 276
 277                 /* new_aeb is newer */
 278                 if (cmp_res & 1) {
 279                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 280                         if (!victim)
 281                                 return -ENOMEM;
 282
 283                         list_add_tail(&victim->u.list, &ai->erase);
 284
 285                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 286                                 av->last_data_size =
 287                                         be32_to_cpu(new_vh->data_size);
 288
 289                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 290                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 291
 292                         aeb->ec = new_aeb->ec;
 293                         aeb->pnum = new_aeb->pnum;
 294                         aeb->copy_flag = new_vh->copy_flag;
 295                         aeb->scrub = new_aeb->scrub;
 296                         aeb->sqnum = new_aeb->sqnum;
 297                         ubi_free_aeb(ai, new_aeb);
 298
 299                 /* new_aeb is older */
 300                 } else {
 301                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 302                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 303                         list_add_tail(&new_aeb->u.list, &ai->erase);
 304                 }
 305
 306                 return 0;
 307         }
 308         /* This LEB is new, let's add it to the volume */
 309
 310         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 311                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 312                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 313         }
 314
 315         if (av->vol_type == UBI_STATIC_VOLUME)
 316                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 317
 318         av->leb_count++;
 319
 320         rb_link_node(&new_aeb->u.rb, parent, p);
 321         rb_insert_color(&new_aeb->u.rb, &av->root);
 322
 323         return 0;
 324 }
 325
 326 /**
 327  * process_pool_aeb - we found a non-empty PEB in a pool.
 328  * @ubi: UBI device object
 329  * @ai: attach info object
 330  * @new_vh: the volume header derived from new_aeb
 331  * @new_aeb: the AEB to be examined
 332  *
 333  * Returns 0 on success, < 0 indicates an internal error.
 334  */
 335 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 336                             struct ubi_vid_hdr *new_vh,
 337                             struct ubi_ainf_peb *new_aeb)
 338 {
 339         int vol_id = be32_to_cpu(new_vh->vol_id);
 340         struct ubi_ainf_volume *av;
 341
 342         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 343                 ubi_free_aeb(ai, new_aeb);
 344
 345                 return 0;
 346         }
 347
 348         /* Find the volume this SEB belongs to */
 349         av = ubi_find_av(ai, vol_id);
 350         if (!av) {
 351                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 352                 ubi_free_aeb(ai, new_aeb);
 353                 return UBI_BAD_FASTMAP;
 354         }
 355
 356         ubi_assert(vol_id == av->vol_id);
 357
 358         return update_vol(ubi, ai, av, new_vh, new_aeb);
 359 }
 360
 361 /**
 362  * unmap_peb - unmap a PEB.
 363  * If fastmap detects a free PEB in the pool it has to check whether
 364  * this PEB has been unmapped after writing the fastmap.
 365  *
 366  * @ai: UBI attach info object
 367  * @pnum: The PEB to be unmapped
 368  */
 369 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 370 {
 371         struct ubi_ainf_volume *av;
 372         struct rb_node *node, *node2;
 373         struct ubi_ainf_peb *aeb;
 374
 375         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 376                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 377                         if (aeb->pnum == pnum) {
 378                                 rb_erase(&aeb->u.rb, &av->root);
 379                                 av->leb_count--;
 380                                 ubi_free_aeb(ai, aeb);
 381                                 return;
 382                         }
 383                 }
 384         }
 385 }
 386
 387 /**
 388  * scan_pool - scans a pool for changed (no longer empty PEBs).
 389  * @ubi: UBI device object
 390  * @ai: attach info object
 391  * @pebs: an array of all PEB numbers in the to be scanned pool
 392  * @pool_size: size of the pool (number of entries in @pebs)
 393  * @max_sqnum: pointer to the maximal sequence number
 394  * @free: list of PEBs which are most likely free (and go into @ai->free)
 395  *
 396  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 397  * < 0 indicates an internal error.
 398  */
 399 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 400                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 401                      struct list_head *free)
 402 {
 403         struct ubi_vid_io_buf *vb;
 404         struct ubi_vid_hdr *vh;
 405         struct ubi_ec_hdr *ech;
 406         struct ubi_ainf_peb *new_aeb;
 407         int i, pnum, err, ret = 0;
 408
 409         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 410         if (!ech)
 411                 return -ENOMEM;
 412
 413         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 414         if (!vb) {
 415                 kfree(ech);
 416                 return -ENOMEM;
 417         }
 418
 419         vh = ubi_get_vid_hdr(vb);
 420
 421         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 422
 423         /*
 424          * Now scan all PEBs in the pool to find changes which have been made
 425          * after the creation of the fastmap
 426          */
 427         for (i = 0; i < pool_size; i++) {
 428                 int scrub = 0;
 429                 int image_seq;
 430
 431                 pnum = be32_to_cpu(pebs[i]);
 432
 433                 if (ubi_io_is_bad(ubi, pnum)) {
 434                         ubi_err(ubi, "bad PEB in fastmap pool!");
 435                         ret = UBI_BAD_FASTMAP;
 436                         goto out;
 437                 }
 438
 439                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 440                 if (err && err != UBI_IO_BITFLIPS) {
 441                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 442                                 pnum, err);
 443                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 444                         goto out;
 445                 } else if (err == UBI_IO_BITFLIPS)
 446                         scrub = 1;
 447
 448                 /*
 449                  * Older UBI implementations have image_seq set to zero, so
 450                  * we shouldn't fail if image_seq == 0.
 451                  */
 452                 image_seq = be32_to_cpu(ech->image_seq);
 453
 454                 if (image_seq && (image_seq != ubi->image_seq)) {
 455                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 456                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 457                         ret = UBI_BAD_FASTMAP;
 458                         goto out;
 459                 }
 460
 461                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 462                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 463                         unsigned long long ec = be64_to_cpu(ech->ec);
 464                         unmap_peb(ai, pnum);
 465                         dbg_bld("Adding PEB to free: %i", pnum);
 466
 467                         if (err == UBI_IO_FF_BITFLIPS)
 468                                 scrub = 1;
 469
 470                         ret = add_aeb(ai, free, pnum, ec, scrub);
 471                         if (ret)
 472                                 goto out;
 473                         continue;
 474                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 475                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 476
 477                         if (err == UBI_IO_BITFLIPS)
 478                                 scrub = 1;
 479
 480                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 481                         if (!new_aeb) {
 482                                 ret = -ENOMEM;
 483                                 goto out;
 484                         }
 485
 486                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 487                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 488                         new_aeb->copy_flag = vh->copy_flag;
 489                         new_aeb->scrub = scrub;
 490
 491                         if (*max_sqnum < new_aeb->sqnum)
 492                                 *max_sqnum = new_aeb->sqnum;
 493
 494                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 495                         if (err) {
 496                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 497                                 goto out;
 498                         }
 499                 } else {
 500                         /* We are paranoid and fall back to scanning mode */
 501                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 502                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 503                         goto out;
 504                 }
 505
 506         }
 507
 508 out:
 509         ubi_free_vid_buf(vb);
 510         kfree(ech);
 511         return ret;
 512 }
 513
 514 /**
 515  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 516  * @ai: The UBI attach info object
 517  */
 518 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 519 {
 520         struct ubi_ainf_peb *aeb;
 521         struct ubi_ainf_volume *av;
 522         struct rb_node *rb1, *rb2;
 523         int n = 0;
 524
 525         list_for_each_entry(aeb, &ai->erase, u.list)
 526                 n++;
 527
 528         list_for_each_entry(aeb, &ai->free, u.list)
 529                 n++;
 530
 531         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 532                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 533                         n++;
 534
 535         return n;
 536 }
 537
 538 /**
 539  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 540  * @ubi: UBI device object
 541  * @ai: UBI attach info object
 542  * @fm: the fastmap to be attached
 543  *
 544  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 545  * < 0 indicates an internal error.
 546  */
 547 static int ubi_attach_fastmap(struct ubi_device *ubi,
 548                               struct ubi_attach_info *ai,
 549                               struct ubi_fastmap_layout *fm)
 550 {
 551         struct list_head used, free;
 552         struct ubi_ainf_volume *av;
 553         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 554         struct ubi_fm_sb *fmsb;
 555         struct ubi_fm_hdr *fmhdr;
 556         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 557         struct ubi_fm_ec *fmec;
 558         struct ubi_fm_volhdr *fmvhdr;
 559         struct ubi_fm_eba *fm_eba;
 560         int ret, i, j, pool_size, wl_pool_size;
 561         size_t fm_pos = 0, fm_size = ubi->fm_size;
 562         unsigned long long max_sqnum = 0;
 563         void *fm_raw = ubi->fm_buf;
 564
 565         INIT_LIST_HEAD(&used);
 566         INIT_LIST_HEAD(&free);
 567         ai->min_ec = UBI_MAX_ERASECOUNTER;
 568
 569         fmsb = (struct ubi_fm_sb *)(fm_raw);
 570         ai->max_sqnum = fmsb->sqnum;
 571         fm_pos += sizeof(struct ubi_fm_sb);
 572         if (fm_pos >= fm_size)
 573                 goto fail_bad;
 574
 575         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 576         fm_pos += sizeof(*fmhdr);
 577         if (fm_pos >= fm_size)
 578                 goto fail_bad;
 579
 580         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 581                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 582                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 583                 goto fail_bad;
 584         }
 585
 586         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 587         fm_pos += sizeof(*fmpl);
 588         if (fm_pos >= fm_size)
 589                 goto fail_bad;
 590         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 591                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 592                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 593                 goto fail_bad;
 594         }
 595
 596         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 597         fm_pos += sizeof(*fmpl_wl);
 598         if (fm_pos >= fm_size)
 599                 goto fail_bad;
 600         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 601                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 602                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 603                 goto fail_bad;
 604         }
 605
 606         pool_size = be16_to_cpu(fmpl->size);
 607         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 608         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 609         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 610
 611         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 612                 ubi_err(ubi, "bad pool size: %i", pool_size);
 613                 goto fail_bad;
 614         }
 615
 616         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 617                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 618                 goto fail_bad;
 619         }
 620
 621
 622         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 623             fm->max_pool_size < 0) {
 624                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 625                 goto fail_bad;
 626         }
 627
 628         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 629             fm->max_wl_pool_size < 0) {
 630                 ubi_err(ubi, "bad maximal WL pool size: %i",
 631                         fm->max_wl_pool_size);
 632                 goto fail_bad;
 633         }
 634
 635         /* read EC values from free list */
 636         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 637                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 638                 fm_pos += sizeof(*fmec);
 639                 if (fm_pos >= fm_size)
 640                         goto fail_bad;
 641
 642                 ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 643                               be32_to_cpu(fmec->ec), 0);
 644                 if (ret)
 645                         goto fail;
 646         }
 647
 648         /* read EC values from used list */
 649         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 650                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 651                 fm_pos += sizeof(*fmec);
 652                 if (fm_pos >= fm_size)
 653                         goto fail_bad;
 654
 655                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 656                               be32_to_cpu(fmec->ec), 0);
 657                 if (ret)
 658                         goto fail;
 659         }
 660
 661         /* read EC values from scrub list */
 662         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 663                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 664                 fm_pos += sizeof(*fmec);
 665                 if (fm_pos >= fm_size)
 666                         goto fail_bad;
 667
 668                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 669                               be32_to_cpu(fmec->ec), 1);
 670                 if (ret)
 671                         goto fail;
 672         }
 673
 674         /* read EC values from erase list */
 675         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 676                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 677                 fm_pos += sizeof(*fmec);
 678                 if (fm_pos >= fm_size)
 679                         goto fail_bad;
 680
 681                 ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 682                               be32_to_cpu(fmec->ec), 1);
 683                 if (ret)
 684                         goto fail;
 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 = bitmap_zalloc(leb_count, GFP_KERNEL);
1111         if (!vol->checkmap)
1112                 return -ENOMEM;
1113
1114         return 0;
1115 }
1116
1117 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1118 {
1119         bitmap_free(vol->checkmap);
1120 }
1121
1122 /**
1123  * ubi_write_fastmap - writes a fastmap.
1124  * @ubi: UBI device object
1125  * @new_fm: the to be written fastmap
1126  *
1127  * Returns 0 on success, < 0 indicates an internal error.
1128  */
1129 static int ubi_write_fastmap(struct ubi_device *ubi,
1130                              struct ubi_fastmap_layout *new_fm)
1131 {
1132         size_t fm_pos = 0;
1133         void *fm_raw;
1134         struct ubi_fm_sb *fmsb;
1135         struct ubi_fm_hdr *fmh;
1136         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1137         struct ubi_fm_ec *fec;
1138         struct ubi_fm_volhdr *fvh;
1139         struct ubi_fm_eba *feba;
1140         struct ubi_wl_entry *wl_e;
1141         struct ubi_volume *vol;
1142         struct ubi_vid_io_buf *avbuf, *dvbuf;
1143         struct ubi_vid_hdr *avhdr, *dvhdr;
1144         struct ubi_work *ubi_wrk;
1145         struct rb_node *tmp_rb;
1146         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1147         int scrub_peb_count, erase_peb_count;
1148         unsigned long *seen_pebs;
1149
1150         fm_raw = ubi->fm_buf;
1151         memset(ubi->fm_buf, 0, ubi->fm_size);
1152
1153         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1154         if (!avbuf) {
1155                 ret = -ENOMEM;
1156                 goto out;
1157         }
1158
1159         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1160         if (!dvbuf) {
1161                 ret = -ENOMEM;
1162                 goto out_free_avbuf;
1163         }
1164
1165         avhdr = ubi_get_vid_hdr(avbuf);
1166         dvhdr = ubi_get_vid_hdr(dvbuf);
1167
1168         seen_pebs = init_seen(ubi);
1169         if (IS_ERR(seen_pebs)) {
1170                 ret = PTR_ERR(seen_pebs);
1171                 goto out_free_dvbuf;
1172         }
1173
1174         spin_lock(&ubi->volumes_lock);
1175         spin_lock(&ubi->wl_lock);
1176
1177         fmsb = (struct ubi_fm_sb *)fm_raw;
1178         fm_pos += sizeof(*fmsb);
1179         ubi_assert(fm_pos <= ubi->fm_size);
1180
1181         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1182         fm_pos += sizeof(*fmh);
1183         ubi_assert(fm_pos <= ubi->fm_size);
1184
1185         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1186         fmsb->version = UBI_FM_FMT_VERSION;
1187         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1188         /* the max sqnum will be filled in while *reading* the fastmap */
1189         fmsb->sqnum = 0;
1190
1191         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1192         free_peb_count = 0;
1193         used_peb_count = 0;
1194         scrub_peb_count = 0;
1195         erase_peb_count = 0;
1196         vol_count = 0;
1197
1198         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1199         fm_pos += sizeof(*fmpl);
1200         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1201         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1202         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1203
1204         for (i = 0; i < ubi->fm_pool.size; i++) {
1205                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1206                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1207         }
1208
1209         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1210         fm_pos += sizeof(*fmpl_wl);
1211         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1212         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1213         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1214
1215         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1216                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1217                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1218         }
1219
1220         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1221                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1222
1223                 fec->pnum = cpu_to_be32(wl_e->pnum);
1224                 set_seen(ubi, wl_e->pnum, seen_pebs);
1225                 fec->ec = cpu_to_be32(wl_e->ec);
1226
1227                 free_peb_count++;
1228                 fm_pos += sizeof(*fec);
1229                 ubi_assert(fm_pos <= ubi->fm_size);
1230         }
1231         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1232
1233         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1234                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1235
1236                 fec->pnum = cpu_to_be32(wl_e->pnum);
1237                 set_seen(ubi, wl_e->pnum, seen_pebs);
1238                 fec->ec = cpu_to_be32(wl_e->ec);
1239
1240                 used_peb_count++;
1241                 fm_pos += sizeof(*fec);
1242                 ubi_assert(fm_pos <= ubi->fm_size);
1243         }
1244
1245         ubi_for_each_protected_peb(ubi, i, wl_e) {
1246                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1247
1248                 fec->pnum = cpu_to_be32(wl_e->pnum);
1249                 set_seen(ubi, wl_e->pnum, seen_pebs);
1250                 fec->ec = cpu_to_be32(wl_e->ec);
1251
1252                 used_peb_count++;
1253                 fm_pos += sizeof(*fec);
1254                 ubi_assert(fm_pos <= ubi->fm_size);
1255         }
1256         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1257
1258         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1259                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1260
1261                 fec->pnum = cpu_to_be32(wl_e->pnum);
1262                 set_seen(ubi, wl_e->pnum, seen_pebs);
1263                 fec->ec = cpu_to_be32(wl_e->ec);
1264
1265                 scrub_peb_count++;
1266                 fm_pos += sizeof(*fec);
1267                 ubi_assert(fm_pos <= ubi->fm_size);
1268         }
1269         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1270
1271
1272         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1273                 if (ubi_is_erase_work(ubi_wrk)) {
1274                         wl_e = ubi_wrk->e;
1275                         ubi_assert(wl_e);
1276
1277                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1278
1279                         fec->pnum = cpu_to_be32(wl_e->pnum);
1280                         set_seen(ubi, wl_e->pnum, seen_pebs);
1281                         fec->ec = cpu_to_be32(wl_e->ec);
1282
1283                         erase_peb_count++;
1284                         fm_pos += sizeof(*fec);
1285                         ubi_assert(fm_pos <= ubi->fm_size);
1286                 }
1287         }
1288         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1289
1290         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1291                 vol = ubi->volumes[i];
1292
1293                 if (!vol)
1294                         continue;
1295
1296                 vol_count++;
1297
1298                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1299                 fm_pos += sizeof(*fvh);
1300                 ubi_assert(fm_pos <= ubi->fm_size);
1301
1302                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1303                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1304                 fvh->vol_type = vol->vol_type;
1305                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1306                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1307                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1308
1309                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1310                         vol->vol_type == UBI_STATIC_VOLUME);
1311
1312                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1313                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1314                 ubi_assert(fm_pos <= ubi->fm_size);
1315
1316                 for (j = 0; j < vol->reserved_pebs; j++) {
1317                         struct ubi_eba_leb_desc ldesc;
1318
1319                         ubi_eba_get_ldesc(vol, j, &ldesc);
1320                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1321                 }
1322
1323                 feba->reserved_pebs = cpu_to_be32(j);
1324                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1325         }
1326         fmh->vol_count = cpu_to_be32(vol_count);
1327         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1328
1329         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1330         avhdr->lnum = 0;
1331
1332         spin_unlock(&ubi->wl_lock);
1333         spin_unlock(&ubi->volumes_lock);
1334
1335         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1336         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1337         if (ret) {
1338                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1339                 goto out_free_seen;
1340         }
1341
1342         for (i = 0; i < new_fm->used_blocks; i++) {
1343                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1344                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1345                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1346         }
1347
1348         fmsb->data_crc = 0;
1349         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1350                                            ubi->fm_size));
1351
1352         for (i = 1; i < new_fm->used_blocks; i++) {
1353                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1354                 dvhdr->lnum = cpu_to_be32(i);
1355                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1356                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1357                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1358                 if (ret) {
1359                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1360                                 new_fm->e[i]->pnum);
1361                         goto out_free_seen;
1362                 }
1363         }
1364
1365         for (i = 0; i < new_fm->used_blocks; i++) {
1366                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1367                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1368                 if (ret) {
1369                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1370                                 new_fm->e[i]->pnum);
1371                         goto out_free_seen;
1372                 }
1373         }
1374
1375         ubi_assert(new_fm);
1376         ubi->fm = new_fm;
1377
1378         ret = self_check_seen(ubi, seen_pebs);
1379         dbg_bld("fastmap written!");
1380
1381 out_free_seen:
1382         free_seen(seen_pebs);
1383 out_free_dvbuf:
1384         ubi_free_vid_buf(dvbuf);
1385 out_free_avbuf:
1386         ubi_free_vid_buf(avbuf);
1387
1388 out:
1389         return ret;
1390 }
1391
1392 /**
1393  * erase_block - Manually erase a PEB.
1394  * @ubi: UBI device object
1395  * @pnum: PEB to be erased
1396  *
1397  * Returns the new EC value on success, < 0 indicates an internal error.
1398  */
1399 static int erase_block(struct ubi_device *ubi, int pnum)
1400 {
1401         int ret;
1402         struct ubi_ec_hdr *ec_hdr;
1403         long long ec;
1404
1405         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1406         if (!ec_hdr)
1407                 return -ENOMEM;
1408
1409         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1410         if (ret < 0)
1411                 goto out;
1412         else if (ret && ret != UBI_IO_BITFLIPS) {
1413                 ret = -EINVAL;
1414                 goto out;
1415         }
1416
1417         ret = ubi_io_sync_erase(ubi, pnum, 0);
1418         if (ret < 0)
1419                 goto out;
1420
1421         ec = be64_to_cpu(ec_hdr->ec);
1422         ec += ret;
1423         if (ec > UBI_MAX_ERASECOUNTER) {
1424                 ret = -EINVAL;
1425                 goto out;
1426         }
1427
1428         ec_hdr->ec = cpu_to_be64(ec);
1429         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1430         if (ret < 0)
1431                 goto out;
1432
1433         ret = ec;
1434 out:
1435         kfree(ec_hdr);
1436         return ret;
1437 }
1438
1439 /**
1440  * invalidate_fastmap - destroys a fastmap.
1441  * @ubi: UBI device object
1442  *
1443  * This function ensures that upon next UBI attach a full scan
1444  * is issued. We need this if UBI is about to write a new fastmap
1445  * but is unable to do so. In this case we have two options:
1446  * a) Make sure that the current fastmap will not be usued upon
1447  * attach time and contine or b) fall back to RO mode to have the
1448  * current fastmap in a valid state.
1449  * Returns 0 on success, < 0 indicates an internal error.
1450  */
1451 static int invalidate_fastmap(struct ubi_device *ubi)
1452 {
1453         int ret;
1454         struct ubi_fastmap_layout *fm;
1455         struct ubi_wl_entry *e;
1456         struct ubi_vid_io_buf *vb = NULL;
1457         struct ubi_vid_hdr *vh;
1458
1459         if (!ubi->fm)
1460                 return 0;
1461
1462         ubi->fm = NULL;
1463
1464         ret = -ENOMEM;
1465         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1466         if (!fm)
1467                 goto out;
1468
1469         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1470         if (!vb)
1471                 goto out_free_fm;
1472
1473         vh = ubi_get_vid_hdr(vb);
1474
1475         ret = -ENOSPC;
1476         e = ubi_wl_get_fm_peb(ubi, 1);
1477         if (!e)
1478                 goto out_free_fm;
1479
1480         /*
1481          * Create fake fastmap such that UBI will fall back
1482          * to scanning mode.
1483          */
1484         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1485         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1486         if (ret < 0) {
1487                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1488                 goto out_free_fm;
1489         }
1490
1491         fm->used_blocks = 1;
1492         fm->e[0] = e;
1493
1494         ubi->fm = fm;
1495
1496 out:
1497         ubi_free_vid_buf(vb);
1498         return ret;
1499
1500 out_free_fm:
1501         kfree(fm);
1502         goto out;
1503 }
1504
1505 /**
1506  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1507  * WL sub-system.
1508  * @ubi: UBI device object
1509  * @fm: fastmap layout object
1510  */
1511 static void return_fm_pebs(struct ubi_device *ubi,
1512                            struct ubi_fastmap_layout *fm)
1513 {
1514         int i;
1515
1516         if (!fm)
1517                 return;
1518
1519         for (i = 0; i < fm->used_blocks; i++) {
1520                 if (fm->e[i]) {
1521                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1522                                           fm->to_be_tortured[i]);
1523                         fm->e[i] = NULL;
1524                 }
1525         }
1526 }
1527
1528 /**
1529  * ubi_update_fastmap - will be called by UBI if a volume changes or
1530  * a fastmap pool becomes full.
1531  * @ubi: UBI device object
1532  *
1533  * Returns 0 on success, < 0 indicates an internal error.
1534  */
1535 int ubi_update_fastmap(struct ubi_device *ubi)
1536 {
1537         int ret, i, j;
1538         struct ubi_fastmap_layout *new_fm, *old_fm;
1539         struct ubi_wl_entry *tmp_e;
1540
1541         down_write(&ubi->fm_protect);
1542         down_write(&ubi->work_sem);
1543         down_write(&ubi->fm_eba_sem);
1544
1545         ubi_refill_pools(ubi);
1546
1547         if (ubi->ro_mode || ubi->fm_disabled) {
1548                 up_write(&ubi->fm_eba_sem);
1549                 up_write(&ubi->work_sem);
1550                 up_write(&ubi->fm_protect);
1551                 return 0;
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->fm_anchor;
1625         ubi->fm_anchor = NULL;
1626         spin_unlock(&ubi->wl_lock);
1627
1628         if (old_fm) {
1629                 /* no fresh anchor PEB was found, reuse the old one */
1630                 if (!tmp_e) {
1631                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1632                         if (ret < 0) {
1633                                 ubi_err(ubi, "could not erase old anchor PEB");
1634
1635                                 for (i = 1; i < new_fm->used_blocks; i++) {
1636                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1637                                                           i, 0);
1638                                         new_fm->e[i] = NULL;
1639                                 }
1640                                 goto err;
1641                         }
1642                         new_fm->e[0] = old_fm->e[0];
1643                         new_fm->e[0]->ec = ret;
1644                         old_fm->e[0] = NULL;
1645                 } else {
1646                         /* we've got a new anchor PEB, return the old one */
1647                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1648                                           old_fm->to_be_tortured[0]);
1649                         new_fm->e[0] = tmp_e;
1650                         old_fm->e[0] = NULL;
1651                 }
1652         } else {
1653                 if (!tmp_e) {
1654                         ubi_err(ubi, "could not find any anchor PEB");
1655
1656                         for (i = 1; i < new_fm->used_blocks; i++) {
1657                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1658                                 new_fm->e[i] = NULL;
1659                         }
1660
1661                         ret = -ENOSPC;
1662                         goto err;
1663                 }
1664                 new_fm->e[0] = tmp_e;
1665         }
1666
1667         ret = ubi_write_fastmap(ubi, new_fm);
1668
1669         if (ret)
1670                 goto err;
1671
1672 out_unlock:
1673         up_write(&ubi->fm_eba_sem);
1674         up_write(&ubi->work_sem);
1675         up_write(&ubi->fm_protect);
1676         kfree(old_fm);
1677
1678         ubi_ensure_anchor_pebs(ubi);
1679
1680         return ret;
1681
1682 err:
1683         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1684
1685         ret = invalidate_fastmap(ubi);
1686         if (ret < 0) {
1687                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1688                 ubi_ro_mode(ubi);
1689         } else {
1690                 return_fm_pebs(ubi, old_fm);
1691                 return_fm_pebs(ubi, new_fm);
1692                 ret = 0;
1693         }
1694
1695         kfree(new_fm);
1696         goto out_unlock;
1697 }