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 = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  24                       GFP_KERNEL);
  25         if (!ret)
  26                 return ERR_PTR(-ENOMEM);
  27
  28         return ret;
  29 }
  30
  31 /**
  32  * free_seen - free the seen logic integer array.
  33  * @seen: integer array of @ubi->peb_count size
  34  */
  35 static inline void free_seen(unsigned long *seen)
  36 {
  37         kfree(seen);
  38 }
  39
  40 /**
  41  * set_seen - mark a PEB as seen.
  42  * @ubi: UBI device description object
  43  * @pnum: The PEB to be makred as seen
  44  * @seen: integer array of @ubi->peb_count size
  45  */
  46 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  47 {
  48         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  49                 return;
  50
  51         set_bit(pnum, seen);
  52 }
  53
  54 /**
  55  * self_check_seen - check whether all PEB have been seen by fastmap.
  56  * @ubi: UBI device description object
  57  * @seen: integer array of @ubi->peb_count size
  58  */
  59 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  60 {
  61         int pnum, ret = 0;
  62
  63         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  64                 return 0;
  65
  66         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  67                 if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  68                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  69                         ret = -EINVAL;
  70                 }
  71         }
  72
  73         return ret;
  74 }
  75
  76 /**
  77  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  78  * @ubi: UBI device description object
  79  */
  80 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  81 {
  82         size_t size;
  83
  84         size = sizeof(struct ubi_fm_sb) +
  85                 sizeof(struct ubi_fm_hdr) +
  86                 sizeof(struct ubi_fm_scan_pool) +
  87                 sizeof(struct ubi_fm_scan_pool) +
  88                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  89                 ((sizeof(struct ubi_fm_eba) +
  90                   sizeof(struct ubi_fm_volhdr)) *
  91                  (UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT)) +
  92                 (ubi->peb_count * sizeof(__be32));
  93         return roundup(size, ubi->leb_size);
  94 }
  95
  96
  97 /**
  98  * new_fm_vhdr - allocate a new volume header for fastmap usage.
  99  * @ubi: UBI device description object
 100  * @vol_id: the VID of the new header
 101  *
 102  * Returns a new struct ubi_vid_hdr on success.
 103  * NULL indicates out of memory.
 104  */
 105 static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 106 {
 107         struct ubi_vid_io_buf *new;
 108         struct ubi_vid_hdr *vh;
 109
 110         new = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 111         if (!new)
 112                 goto out;
 113
 114         vh = ubi_get_vid_hdr(new);
 115         vh->vol_type = UBI_VID_DYNAMIC;
 116         vh->vol_id = cpu_to_be32(vol_id);
 117
 118         /* UBI implementations without fastmap support have to delete the
 119          * fastmap.
 120          */
 121         vh->compat = UBI_COMPAT_DELETE;
 122
 123 out:
 124         return new;
 125 }
 126
 127 /**
 128  * add_aeb - create and add a attach erase block to a given list.
 129  * @ai: UBI attach info object
 130  * @list: the target list
 131  * @pnum: PEB number of the new attach erase block
 132  * @ec: erease counter of the new LEB
 133  * @scrub: scrub this PEB after attaching
 134  *
 135  * Returns 0 on success, < 0 indicates an internal error.
 136  */
 137 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 138                    int pnum, int ec, int scrub)
 139 {
 140         struct ubi_ainf_peb *aeb;
 141
 142         aeb = ubi_alloc_aeb(ai, pnum, ec);
 143         if (!aeb)
 144                 return -ENOMEM;
 145
 146         aeb->lnum = -1;
 147         aeb->scrub = scrub;
 148         aeb->copy_flag = aeb->sqnum = 0;
 149
 150         ai->ec_sum += aeb->ec;
 151         ai->ec_count++;
 152
 153         if (ai->max_ec < aeb->ec)
 154                 ai->max_ec = aeb->ec;
 155
 156         if (ai->min_ec > aeb->ec)
 157                 ai->min_ec = aeb->ec;
 158
 159         list_add_tail(&aeb->u.list, list);
 160
 161         return 0;
 162 }
 163
 164 /**
 165  * add_vol - create and add a new volume to ubi_attach_info.
 166  * @ai: ubi_attach_info object
 167  * @vol_id: VID of the new volume
 168  * @used_ebs: number of used EBS
 169  * @data_pad: data padding value of the new volume
 170  * @vol_type: volume type
 171  * @last_eb_bytes: number of bytes in the last LEB
 172  *
 173  * Returns the new struct ubi_ainf_volume on success.
 174  * NULL indicates an error.
 175  */
 176 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 177                                        int used_ebs, int data_pad, u8 vol_type,
 178                                        int last_eb_bytes)
 179 {
 180         struct ubi_ainf_volume *av;
 181
 182         av = ubi_add_av(ai, vol_id);
 183         if (IS_ERR(av))
 184                 return av;
 185
 186         av->data_pad = data_pad;
 187         av->last_data_size = last_eb_bytes;
 188         av->compat = 0;
 189         av->vol_type = vol_type;
 190         if (av->vol_type == UBI_STATIC_VOLUME)
 191                 av->used_ebs = used_ebs;
 192
 193         dbg_bld("found volume (ID %i)", vol_id);
 194         return av;
 195 }
 196
 197 /**
 198  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 199  * from it's original list.
 200  * @ai: ubi_attach_info object
 201  * @aeb: the to be assigned SEB
 202  * @av: target scan volume
 203  */
 204 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 205                              struct ubi_ainf_peb *aeb,
 206                              struct ubi_ainf_volume *av)
 207 {
 208         struct ubi_ainf_peb *tmp_aeb;
 209         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 210
 211         while (*p) {
 212                 parent = *p;
 213
 214                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 215                 if (aeb->lnum != tmp_aeb->lnum) {
 216                         if (aeb->lnum < tmp_aeb->lnum)
 217                                 p = &(*p)->rb_left;
 218                         else
 219                                 p = &(*p)->rb_right;
 220
 221                         continue;
 222                 } else
 223                         break;
 224         }
 225
 226         list_del(&aeb->u.list);
 227         av->leb_count++;
 228
 229         rb_link_node(&aeb->u.rb, parent, p);
 230         rb_insert_color(&aeb->u.rb, &av->root);
 231 }
 232
 233 /**
 234  * update_vol - inserts or updates a LEB which was found a pool.
 235  * @ubi: the UBI device object
 236  * @ai: attach info object
 237  * @av: the volume this LEB belongs to
 238  * @new_vh: the volume header derived from new_aeb
 239  * @new_aeb: the AEB to be examined
 240  *
 241  * Returns 0 on success, < 0 indicates an internal error.
 242  */
 243 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 244                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 245                       struct ubi_ainf_peb *new_aeb)
 246 {
 247         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 248         struct ubi_ainf_peb *aeb, *victim;
 249         int cmp_res;
 250
 251         while (*p) {
 252                 parent = *p;
 253                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 254
 255                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 256                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 257                                 p = &(*p)->rb_left;
 258                         else
 259                                 p = &(*p)->rb_right;
 260
 261                         continue;
 262                 }
 263
 264                 /* This case can happen if the fastmap gets written
 265                  * because of a volume change (creation, deletion, ..).
 266                  * Then a PEB can be within the persistent EBA and the pool.
 267                  */
 268                 if (aeb->pnum == new_aeb->pnum) {
 269                         ubi_assert(aeb->lnum == new_aeb->lnum);
 270                         ubi_free_aeb(ai, new_aeb);
 271
 272                         return 0;
 273                 }
 274
 275                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 276                 if (cmp_res < 0)
 277                         return cmp_res;
 278
 279                 /* new_aeb is newer */
 280                 if (cmp_res & 1) {
 281                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 282                         if (!victim)
 283                                 return -ENOMEM;
 284
 285                         list_add_tail(&victim->u.list, &ai->erase);
 286
 287                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 288                                 av->last_data_size =
 289                                         be32_to_cpu(new_vh->data_size);
 290
 291                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 292                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 293
 294                         aeb->ec = new_aeb->ec;
 295                         aeb->pnum = new_aeb->pnum;
 296                         aeb->copy_flag = new_vh->copy_flag;
 297                         aeb->scrub = new_aeb->scrub;
 298                         aeb->sqnum = new_aeb->sqnum;
 299                         ubi_free_aeb(ai, new_aeb);
 300
 301                 /* new_aeb is older */
 302                 } else {
 303                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 304                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 305                         list_add_tail(&new_aeb->u.list, &ai->erase);
 306                 }
 307
 308                 return 0;
 309         }
 310         /* This LEB is new, let's add it to the volume */
 311
 312         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 313                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 314                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 315         }
 316
 317         if (av->vol_type == UBI_STATIC_VOLUME)
 318                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 319
 320         av->leb_count++;
 321
 322         rb_link_node(&new_aeb->u.rb, parent, p);
 323         rb_insert_color(&new_aeb->u.rb, &av->root);
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * process_pool_aeb - we found a non-empty PEB in a pool.
 330  * @ubi: UBI device object
 331  * @ai: attach info object
 332  * @new_vh: the volume header derived from new_aeb
 333  * @new_aeb: the AEB to be examined
 334  *
 335  * Returns 0 on success, < 0 indicates an internal error.
 336  */
 337 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 338                             struct ubi_vid_hdr *new_vh,
 339                             struct ubi_ainf_peb *new_aeb)
 340 {
 341         int vol_id = be32_to_cpu(new_vh->vol_id);
 342         struct ubi_ainf_volume *av;
 343
 344         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 345                 ubi_free_aeb(ai, new_aeb);
 346
 347                 return 0;
 348         }
 349
 350         /* Find the volume this SEB belongs to */
 351         av = ubi_find_av(ai, vol_id);
 352         if (!av) {
 353                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 354                 ubi_free_aeb(ai, new_aeb);
 355                 return UBI_BAD_FASTMAP;
 356         }
 357
 358         ubi_assert(vol_id == av->vol_id);
 359
 360         return update_vol(ubi, ai, av, new_vh, new_aeb);
 361 }
 362
 363 /**
 364  * unmap_peb - unmap a PEB.
 365  * If fastmap detects a free PEB in the pool it has to check whether
 366  * this PEB has been unmapped after writing the fastmap.
 367  *
 368  * @ai: UBI attach info object
 369  * @pnum: The PEB to be unmapped
 370  */
 371 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 372 {
 373         struct ubi_ainf_volume *av;
 374         struct rb_node *node, *node2;
 375         struct ubi_ainf_peb *aeb;
 376
 377         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 378                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 379                         if (aeb->pnum == pnum) {
 380                                 rb_erase(&aeb->u.rb, &av->root);
 381                                 av->leb_count--;
 382                                 ubi_free_aeb(ai, aeb);
 383                                 return;
 384                         }
 385                 }
 386         }
 387 }
 388
 389 /**
 390  * scan_pool - scans a pool for changed (no longer empty PEBs).
 391  * @ubi: UBI device object
 392  * @ai: attach info object
 393  * @pebs: an array of all PEB numbers in the to be scanned pool
 394  * @pool_size: size of the pool (number of entries in @pebs)
 395  * @max_sqnum: pointer to the maximal sequence number
 396  * @free: list of PEBs which are most likely free (and go into @ai->free)
 397  *
 398  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 399  * < 0 indicates an internal error.
 400  */
 401 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 402                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 403                      struct list_head *free)
 404 {
 405         struct ubi_vid_io_buf *vb;
 406         struct ubi_vid_hdr *vh;
 407         struct ubi_ec_hdr *ech;
 408         struct ubi_ainf_peb *new_aeb;
 409         int i, pnum, err, ret = 0;
 410
 411         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 412         if (!ech)
 413                 return -ENOMEM;
 414
 415         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 416         if (!vb) {
 417                 kfree(ech);
 418                 return -ENOMEM;
 419         }
 420
 421         vh = ubi_get_vid_hdr(vb);
 422
 423         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 424
 425         /*
 426          * Now scan all PEBs in the pool to find changes which have been made
 427          * after the creation of the fastmap
 428          */
 429         for (i = 0; i < pool_size; i++) {
 430                 int scrub = 0;
 431                 int image_seq;
 432
 433                 pnum = be32_to_cpu(pebs[i]);
 434
 435                 if (ubi_io_is_bad(ubi, pnum)) {
 436                         ubi_err(ubi, "bad PEB in fastmap pool!");
 437                         ret = UBI_BAD_FASTMAP;
 438                         goto out;
 439                 }
 440
 441                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 442                 if (err && err != UBI_IO_BITFLIPS) {
 443                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 444                                 pnum, err);
 445                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 446                         goto out;
 447                 } else if (err == UBI_IO_BITFLIPS)
 448                         scrub = 1;
 449
 450                 /*
 451                  * Older UBI implementations have image_seq set to zero, so
 452                  * we shouldn't fail if image_seq == 0.
 453                  */
 454                 image_seq = be32_to_cpu(ech->image_seq);
 455
 456                 if (image_seq && (image_seq != ubi->image_seq)) {
 457                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 458                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 459                         ret = UBI_BAD_FASTMAP;
 460                         goto out;
 461                 }
 462
 463                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 464                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 465                         unsigned long long ec = be64_to_cpu(ech->ec);
 466                         unmap_peb(ai, pnum);
 467                         dbg_bld("Adding PEB to free: %i", pnum);
 468
 469                         if (err == UBI_IO_FF_BITFLIPS)
 470                                 scrub = 1;
 471
 472                         ret = add_aeb(ai, free, pnum, ec, scrub);
 473                         if (ret)
 474                                 goto out;
 475                         continue;
 476                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 477                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 478
 479                         if (err == UBI_IO_BITFLIPS)
 480                                 scrub = 1;
 481
 482                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 483                         if (!new_aeb) {
 484                                 ret = -ENOMEM;
 485                                 goto out;
 486                         }
 487
 488                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 489                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 490                         new_aeb->copy_flag = vh->copy_flag;
 491                         new_aeb->scrub = scrub;
 492
 493                         if (*max_sqnum < new_aeb->sqnum)
 494                                 *max_sqnum = new_aeb->sqnum;
 495
 496                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 497                         if (err) {
 498                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 499                                 goto out;
 500                         }
 501                 } else {
 502                         /* We are paranoid and fall back to scanning mode */
 503                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 504                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 505                         goto out;
 506                 }
 507
 508         }
 509
 510 out:
 511         ubi_free_vid_buf(vb);
 512         kfree(ech);
 513         return ret;
 514 }
 515
 516 /**
 517  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 518  * @ai: The UBI attach info object
 519  */
 520 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 521 {
 522         struct ubi_ainf_peb *aeb;
 523         struct ubi_ainf_volume *av;
 524         struct rb_node *rb1, *rb2;
 525         int n = 0;
 526
 527         list_for_each_entry(aeb, &ai->erase, u.list)
 528                 n++;
 529
 530         list_for_each_entry(aeb, &ai->free, u.list)
 531                 n++;
 532
 533         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 534                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 535                         n++;
 536
 537         return n;
 538 }
 539
 540 /**
 541  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 542  * @ubi: UBI device object
 543  * @ai: UBI attach info object
 544  * @fm: the fastmap to be attached
 545  *
 546  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 547  * < 0 indicates an internal error.
 548  */
 549 static int ubi_attach_fastmap(struct ubi_device *ubi,
 550                               struct ubi_attach_info *ai,
 551                               struct ubi_fastmap_layout *fm)
 552 {
 553         struct list_head used, free;
 554         struct ubi_ainf_volume *av;
 555         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 556         struct ubi_fm_sb *fmsb;
 557         struct ubi_fm_hdr *fmhdr;
 558         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 559         struct ubi_fm_ec *fmec;
 560         struct ubi_fm_volhdr *fmvhdr;
 561         struct ubi_fm_eba *fm_eba;
 562         int ret, i, j, pool_size, wl_pool_size;
 563         size_t fm_pos = 0, fm_size = ubi->fm_size;
 564         unsigned long long max_sqnum = 0;
 565         void *fm_raw = ubi->fm_buf;
 566
 567         INIT_LIST_HEAD(&used);
 568         INIT_LIST_HEAD(&free);
 569         ai->min_ec = UBI_MAX_ERASECOUNTER;
 570
 571         fmsb = (struct ubi_fm_sb *)(fm_raw);
 572         ai->max_sqnum = fmsb->sqnum;
 573         fm_pos += sizeof(struct ubi_fm_sb);
 574         if (fm_pos >= fm_size)
 575                 goto fail_bad;
 576
 577         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 578         fm_pos += sizeof(*fmhdr);
 579         if (fm_pos >= fm_size)
 580                 goto fail_bad;
 581
 582         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 583                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 584                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 585                 goto fail_bad;
 586         }
 587
 588         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 589         fm_pos += sizeof(*fmpl);
 590         if (fm_pos >= fm_size)
 591                 goto fail_bad;
 592         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 593                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 594                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 595                 goto fail_bad;
 596         }
 597
 598         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 599         fm_pos += sizeof(*fmpl_wl);
 600         if (fm_pos >= fm_size)
 601                 goto fail_bad;
 602         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 603                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 604                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 605                 goto fail_bad;
 606         }
 607
 608         pool_size = be16_to_cpu(fmpl->size);
 609         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 610         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 611         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 612
 613         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 614                 ubi_err(ubi, "bad pool size: %i", pool_size);
 615                 goto fail_bad;
 616         }
 617
 618         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 619                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 620                 goto fail_bad;
 621         }
 622
 623
 624         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 625             fm->max_pool_size < 0) {
 626                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 627                 goto fail_bad;
 628         }
 629
 630         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 631             fm->max_wl_pool_size < 0) {
 632                 ubi_err(ubi, "bad maximal WL pool size: %i",
 633                         fm->max_wl_pool_size);
 634                 goto fail_bad;
 635         }
 636
 637         /* read EC values from free list */
 638         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 639                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 640                 fm_pos += sizeof(*fmec);
 641                 if (fm_pos >= fm_size)
 642                         goto fail_bad;
 643
 644                 ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 645                               be32_to_cpu(fmec->ec), 0);
 646                 if (ret)
 647                         goto fail;
 648         }
 649
 650         /* read EC values from used list */
 651         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 652                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 653                 fm_pos += sizeof(*fmec);
 654                 if (fm_pos >= fm_size)
 655                         goto fail_bad;
 656
 657                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 658                               be32_to_cpu(fmec->ec), 0);
 659                 if (ret)
 660                         goto fail;
 661         }
 662
 663         /* read EC values from scrub list */
 664         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 665                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 666                 fm_pos += sizeof(*fmec);
 667                 if (fm_pos >= fm_size)
 668                         goto fail_bad;
 669
 670                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 671                               be32_to_cpu(fmec->ec), 1);
 672                 if (ret)
 673                         goto fail;
 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                 ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 684                               be32_to_cpu(fmec->ec), 1);
 685                 if (ret)
 686                         goto fail;
 687         }
 688
 689         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 690         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 691
 692         /* Iterate over all volumes and read their EBA table */
 693         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 694                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 695                 fm_pos += sizeof(*fmvhdr);
 696                 if (fm_pos >= fm_size)
 697                         goto fail_bad;
 698
 699                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 700                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 701                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 702                         goto fail_bad;
 703                 }
 704
 705                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 706                              be32_to_cpu(fmvhdr->used_ebs),
 707                              be32_to_cpu(fmvhdr->data_pad),
 708                              fmvhdr->vol_type,
 709                              be32_to_cpu(fmvhdr->last_eb_bytes));
 710
 711                 if (IS_ERR(av)) {
 712                         if (PTR_ERR(av) == -EEXIST)
 713                                 ubi_err(ubi, "volume (ID %i) already exists",
 714                                         fmvhdr->vol_id);
 715
 716                         goto fail_bad;
 717                 }
 718
 719                 ai->vols_found++;
 720                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 721                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 722
 723                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 724                 fm_pos += sizeof(*fm_eba);
 725                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 726                 if (fm_pos >= fm_size)
 727                         goto fail_bad;
 728
 729                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 730                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 731                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 732                         goto fail_bad;
 733                 }
 734
 735                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 736                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 737
 738                         if (pnum < 0)
 739                                 continue;
 740
 741                         aeb = NULL;
 742                         list_for_each_entry(tmp_aeb, &used, u.list) {
 743                                 if (tmp_aeb->pnum == pnum) {
 744                                         aeb = tmp_aeb;
 745                                         break;
 746                                 }
 747                         }
 748
 749                         if (!aeb) {
 750                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 751                                 goto fail_bad;
 752                         }
 753
 754                         aeb->lnum = j;
 755
 756                         if (av->highest_lnum <= aeb->lnum)
 757                                 av->highest_lnum = aeb->lnum;
 758
 759                         assign_aeb_to_av(ai, aeb, av);
 760
 761                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 762                                 aeb->pnum, aeb->lnum, av->vol_id);
 763                 }
 764         }
 765
 766         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 767         if (ret)
 768                 goto fail;
 769
 770         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 771         if (ret)
 772                 goto fail;
 773
 774         if (max_sqnum > ai->max_sqnum)
 775                 ai->max_sqnum = max_sqnum;
 776
 777         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 778                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 779
 780         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 781                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 782
 783         ubi_assert(list_empty(&free));
 784
 785         /*
 786          * If fastmap is leaking PEBs (must not happen), raise a
 787          * fat warning and fall back to scanning mode.
 788          * We do this here because in ubi_wl_init() it's too late
 789          * and we cannot fall back to scanning.
 790          */
 791         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 792                     ai->bad_peb_count - fm->used_blocks))
 793                 goto fail_bad;
 794
 795         return 0;
 796
 797 fail_bad:
 798         ret = UBI_BAD_FASTMAP;
 799 fail:
 800         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 801                 list_del(&tmp_aeb->u.list);
 802                 ubi_free_aeb(ai, tmp_aeb);
 803         }
 804         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 805                 list_del(&tmp_aeb->u.list);
 806                 ubi_free_aeb(ai, tmp_aeb);
 807         }
 808
 809         return ret;
 810 }
 811
 812 /**
 813  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 814  * @ai: UBI attach info to be filled
 815  */
 816 static int find_fm_anchor(struct ubi_attach_info *ai)
 817 {
 818         int ret = -1;
 819         struct ubi_ainf_peb *aeb;
 820         unsigned long long max_sqnum = 0;
 821
 822         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 823                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 824                         max_sqnum = aeb->sqnum;
 825                         ret = aeb->pnum;
 826                 }
 827         }
 828
 829         return ret;
 830 }
 831
 832 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 833                                       struct ubi_ainf_peb *old)
 834 {
 835         struct ubi_ainf_peb *new;
 836
 837         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 838         if (!new)
 839                 return NULL;
 840
 841         new->vol_id = old->vol_id;
 842         new->sqnum = old->sqnum;
 843         new->lnum = old->lnum;
 844         new->scrub = old->scrub;
 845         new->copy_flag = old->copy_flag;
 846
 847         return new;
 848 }
 849
 850 /**
 851  * ubi_scan_fastmap - scan the fastmap.
 852  * @ubi: UBI device object
 853  * @ai: UBI attach info to be filled
 854  * @scan_ai: UBI attach info from the first 64 PEBs,
 855  *           used to find the most recent Fastmap data structure
 856  *
 857  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 858  * UBI_BAD_FASTMAP if one was found but is not usable.
 859  * < 0 indicates an internal error.
 860  */
 861 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 862                      struct ubi_attach_info *scan_ai)
 863 {
 864         struct ubi_fm_sb *fmsb, *fmsb2;
 865         struct ubi_vid_io_buf *vb;
 866         struct ubi_vid_hdr *vh;
 867         struct ubi_ec_hdr *ech;
 868         struct ubi_fastmap_layout *fm;
 869         struct ubi_ainf_peb *aeb;
 870         int i, used_blocks, pnum, fm_anchor, ret = 0;
 871         size_t fm_size;
 872         __be32 crc, tmp_crc;
 873         unsigned long long sqnum = 0;
 874
 875         fm_anchor = find_fm_anchor(scan_ai);
 876         if (fm_anchor < 0)
 877                 return UBI_NO_FASTMAP;
 878
 879         /* Copy all (possible) fastmap blocks into our new attach structure. */
 880         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 881                 struct ubi_ainf_peb *new;
 882
 883                 new = clone_aeb(ai, aeb);
 884                 if (!new)
 885                         return -ENOMEM;
 886
 887                 list_add(&new->u.list, &ai->fastmap);
 888         }
 889
 890         down_write(&ubi->fm_protect);
 891         memset(ubi->fm_buf, 0, ubi->fm_size);
 892
 893         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 894         if (!fmsb) {
 895                 ret = -ENOMEM;
 896                 goto out;
 897         }
 898
 899         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 900         if (!fm) {
 901                 ret = -ENOMEM;
 902                 kfree(fmsb);
 903                 goto out;
 904         }
 905
 906         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 907         if (ret && ret != UBI_IO_BITFLIPS)
 908                 goto free_fm_sb;
 909         else if (ret == UBI_IO_BITFLIPS)
 910                 fm->to_be_tortured[0] = 1;
 911
 912         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 913                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 914                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 915                 ret = UBI_BAD_FASTMAP;
 916                 goto free_fm_sb;
 917         }
 918
 919         if (fmsb->version != UBI_FM_FMT_VERSION) {
 920                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 921                         fmsb->version, UBI_FM_FMT_VERSION);
 922                 ret = UBI_BAD_FASTMAP;
 923                 goto free_fm_sb;
 924         }
 925
 926         used_blocks = be32_to_cpu(fmsb->used_blocks);
 927         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 928                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 929                         used_blocks);
 930                 ret = UBI_BAD_FASTMAP;
 931                 goto free_fm_sb;
 932         }
 933
 934         fm_size = ubi->leb_size * used_blocks;
 935         if (fm_size != ubi->fm_size) {
 936                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 937                         fm_size, ubi->fm_size);
 938                 ret = UBI_BAD_FASTMAP;
 939                 goto free_fm_sb;
 940         }
 941
 942         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 943         if (!ech) {
 944                 ret = -ENOMEM;
 945                 goto free_fm_sb;
 946         }
 947
 948         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 949         if (!vb) {
 950                 ret = -ENOMEM;
 951                 goto free_hdr;
 952         }
 953
 954         vh = ubi_get_vid_hdr(vb);
 955
 956         for (i = 0; i < used_blocks; i++) {
 957                 int image_seq;
 958
 959                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 960
 961                 if (ubi_io_is_bad(ubi, pnum)) {
 962                         ret = UBI_BAD_FASTMAP;
 963                         goto free_hdr;
 964                 }
 965
 966                 if (i == 0 && pnum != fm_anchor) {
 967                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 968                                 pnum, fm_anchor);
 969                         ret = UBI_BAD_FASTMAP;
 970                         goto free_hdr;
 971                 }
 972
 973                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 974                 if (ret && ret != UBI_IO_BITFLIPS) {
 975                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 976                                 i, pnum);
 977                         if (ret > 0)
 978                                 ret = UBI_BAD_FASTMAP;
 979                         goto free_hdr;
 980                 } else if (ret == UBI_IO_BITFLIPS)
 981                         fm->to_be_tortured[i] = 1;
 982
 983                 image_seq = be32_to_cpu(ech->image_seq);
 984                 if (!ubi->image_seq)
 985                         ubi->image_seq = image_seq;
 986
 987                 /*
 988                  * Older UBI implementations have image_seq set to zero, so
 989                  * we shouldn't fail if image_seq == 0.
 990                  */
 991                 if (image_seq && (image_seq != ubi->image_seq)) {
 992                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 993                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 994                         ret = UBI_BAD_FASTMAP;
 995                         goto free_hdr;
 996                 }
 997
 998                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 999                 if (ret && ret != UBI_IO_BITFLIPS) {
1000                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1001                                 i, pnum);
1002                         goto free_hdr;
1003                 }
1004
1005                 if (i == 0) {
1006                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1007                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1008                                         be32_to_cpu(vh->vol_id),
1009                                         UBI_FM_SB_VOLUME_ID);
1010                                 ret = UBI_BAD_FASTMAP;
1011                                 goto free_hdr;
1012                         }
1013                 } else {
1014                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1015                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1016                                         be32_to_cpu(vh->vol_id),
1017                                         UBI_FM_DATA_VOLUME_ID);
1018                                 ret = UBI_BAD_FASTMAP;
1019                                 goto free_hdr;
1020                         }
1021                 }
1022
1023                 if (sqnum < be64_to_cpu(vh->sqnum))
1024                         sqnum = be64_to_cpu(vh->sqnum);
1025
1026                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1027                                        pnum, 0, ubi->leb_size);
1028                 if (ret && ret != UBI_IO_BITFLIPS) {
1029                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1030                                 "err: %i)", i, pnum, ret);
1031                         goto free_hdr;
1032                 }
1033         }
1034
1035         kfree(fmsb);
1036         fmsb = NULL;
1037
1038         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1039         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1040         fmsb2->data_crc = 0;
1041         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1042         if (crc != tmp_crc) {
1043                 ubi_err(ubi, "fastmap data CRC is invalid");
1044                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1045                         tmp_crc, crc);
1046                 ret = UBI_BAD_FASTMAP;
1047                 goto free_hdr;
1048         }
1049
1050         fmsb2->sqnum = sqnum;
1051
1052         fm->used_blocks = used_blocks;
1053
1054         ret = ubi_attach_fastmap(ubi, ai, fm);
1055         if (ret) {
1056                 if (ret > 0)
1057                         ret = UBI_BAD_FASTMAP;
1058                 goto free_hdr;
1059         }
1060
1061         for (i = 0; i < used_blocks; i++) {
1062                 struct ubi_wl_entry *e;
1063
1064                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1065                 if (!e) {
1066                         while (i--)
1067                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1068
1069                         ret = -ENOMEM;
1070                         goto free_hdr;
1071                 }
1072
1073                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1074                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1075                 fm->e[i] = e;
1076         }
1077
1078         ubi->fm = fm;
1079         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1080         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1081         ubi_msg(ubi, "attached by fastmap");
1082         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1083         ubi_msg(ubi, "fastmap WL pool size: %d",
1084                 ubi->fm_wl_pool.max_size);
1085         ubi->fm_disabled = 0;
1086         ubi->fast_attach = 1;
1087
1088         ubi_free_vid_buf(vb);
1089         kfree(ech);
1090 out:
1091         up_write(&ubi->fm_protect);
1092         if (ret == UBI_BAD_FASTMAP)
1093                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1094         return ret;
1095
1096 free_hdr:
1097         ubi_free_vid_buf(vb);
1098         kfree(ech);
1099 free_fm_sb:
1100         kfree(fmsb);
1101         kfree(fm);
1102         goto out;
1103 }
1104
1105 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1106 {
1107         struct ubi_device *ubi = vol->ubi;
1108
1109         if (!ubi->fast_attach)
1110                 return 0;
1111
1112         vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
1113                                 GFP_KERNEL);
1114         if (!vol->checkmap)
1115                 return -ENOMEM;
1116
1117         return 0;
1118 }
1119
1120 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1121 {
1122         kfree(vol->checkmap);
1123 }
1124
1125 /**
1126  * ubi_write_fastmap - writes a fastmap.
1127  * @ubi: UBI device object
1128  * @new_fm: the to be written fastmap
1129  *
1130  * Returns 0 on success, < 0 indicates an internal error.
1131  */
1132 static int ubi_write_fastmap(struct ubi_device *ubi,
1133                              struct ubi_fastmap_layout *new_fm)
1134 {
1135         size_t fm_pos = 0;
1136         void *fm_raw;
1137         struct ubi_fm_sb *fmsb;
1138         struct ubi_fm_hdr *fmh;
1139         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1140         struct ubi_fm_ec *fec;
1141         struct ubi_fm_volhdr *fvh;
1142         struct ubi_fm_eba *feba;
1143         struct ubi_wl_entry *wl_e;
1144         struct ubi_volume *vol;
1145         struct ubi_vid_io_buf *avbuf, *dvbuf;
1146         struct ubi_vid_hdr *avhdr, *dvhdr;
1147         struct ubi_work *ubi_wrk;
1148         struct rb_node *tmp_rb;
1149         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1150         int scrub_peb_count, erase_peb_count;
1151         unsigned long *seen_pebs;
1152
1153         fm_raw = ubi->fm_buf;
1154         memset(ubi->fm_buf, 0, ubi->fm_size);
1155
1156         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1157         if (!avbuf) {
1158                 ret = -ENOMEM;
1159                 goto out;
1160         }
1161
1162         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1163         if (!dvbuf) {
1164                 ret = -ENOMEM;
1165                 goto out_free_avbuf;
1166         }
1167
1168         avhdr = ubi_get_vid_hdr(avbuf);
1169         dvhdr = ubi_get_vid_hdr(dvbuf);
1170
1171         seen_pebs = init_seen(ubi);
1172         if (IS_ERR(seen_pebs)) {
1173                 ret = PTR_ERR(seen_pebs);
1174                 goto out_free_dvbuf;
1175         }
1176
1177         spin_lock(&ubi->volumes_lock);
1178         spin_lock(&ubi->wl_lock);
1179
1180         fmsb = (struct ubi_fm_sb *)fm_raw;
1181         fm_pos += sizeof(*fmsb);
1182         ubi_assert(fm_pos <= ubi->fm_size);
1183
1184         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1185         fm_pos += sizeof(*fmh);
1186         ubi_assert(fm_pos <= ubi->fm_size);
1187
1188         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1189         fmsb->version = UBI_FM_FMT_VERSION;
1190         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1191         /* the max sqnum will be filled in while *reading* the fastmap */
1192         fmsb->sqnum = 0;
1193
1194         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1195         free_peb_count = 0;
1196         used_peb_count = 0;
1197         scrub_peb_count = 0;
1198         erase_peb_count = 0;
1199         vol_count = 0;
1200
1201         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1202         fm_pos += sizeof(*fmpl);
1203         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1204         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1205         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1206
1207         for (i = 0; i < ubi->fm_pool.size; i++) {
1208                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1209                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1210         }
1211
1212         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1213         fm_pos += sizeof(*fmpl_wl);
1214         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1215         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1216         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1217
1218         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1219                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1220                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1221         }
1222
1223         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1224                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1225
1226                 fec->pnum = cpu_to_be32(wl_e->pnum);
1227                 set_seen(ubi, wl_e->pnum, seen_pebs);
1228                 fec->ec = cpu_to_be32(wl_e->ec);
1229
1230                 free_peb_count++;
1231                 fm_pos += sizeof(*fec);
1232                 ubi_assert(fm_pos <= ubi->fm_size);
1233         }
1234         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1235
1236         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1237                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1238
1239                 fec->pnum = cpu_to_be32(wl_e->pnum);
1240                 set_seen(ubi, wl_e->pnum, seen_pebs);
1241                 fec->ec = cpu_to_be32(wl_e->ec);
1242
1243                 used_peb_count++;
1244                 fm_pos += sizeof(*fec);
1245                 ubi_assert(fm_pos <= ubi->fm_size);
1246         }
1247
1248         ubi_for_each_protected_peb(ubi, i, wl_e) {
1249                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1250
1251                 fec->pnum = cpu_to_be32(wl_e->pnum);
1252                 set_seen(ubi, wl_e->pnum, seen_pebs);
1253                 fec->ec = cpu_to_be32(wl_e->ec);
1254
1255                 used_peb_count++;
1256                 fm_pos += sizeof(*fec);
1257                 ubi_assert(fm_pos <= ubi->fm_size);
1258         }
1259         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1260
1261         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1262                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1263
1264                 fec->pnum = cpu_to_be32(wl_e->pnum);
1265                 set_seen(ubi, wl_e->pnum, seen_pebs);
1266                 fec->ec = cpu_to_be32(wl_e->ec);
1267
1268                 scrub_peb_count++;
1269                 fm_pos += sizeof(*fec);
1270                 ubi_assert(fm_pos <= ubi->fm_size);
1271         }
1272         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1273
1274
1275         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1276                 if (ubi_is_erase_work(ubi_wrk)) {
1277                         wl_e = ubi_wrk->e;
1278                         ubi_assert(wl_e);
1279
1280                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1281
1282                         fec->pnum = cpu_to_be32(wl_e->pnum);
1283                         set_seen(ubi, wl_e->pnum, seen_pebs);
1284                         fec->ec = cpu_to_be32(wl_e->ec);
1285
1286                         erase_peb_count++;
1287                         fm_pos += sizeof(*fec);
1288                         ubi_assert(fm_pos <= ubi->fm_size);
1289                 }
1290         }
1291         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1292
1293         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1294                 vol = ubi->volumes[i];
1295
1296                 if (!vol)
1297                         continue;
1298
1299                 vol_count++;
1300
1301                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1302                 fm_pos += sizeof(*fvh);
1303                 ubi_assert(fm_pos <= ubi->fm_size);
1304
1305                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1306                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1307                 fvh->vol_type = vol->vol_type;
1308                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1309                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1310                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1311
1312                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1313                         vol->vol_type == UBI_STATIC_VOLUME);
1314
1315                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1316                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1317                 ubi_assert(fm_pos <= ubi->fm_size);
1318
1319                 for (j = 0; j < vol->reserved_pebs; j++) {
1320                         struct ubi_eba_leb_desc ldesc;
1321
1322                         ubi_eba_get_ldesc(vol, j, &ldesc);
1323                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1324                 }
1325
1326                 feba->reserved_pebs = cpu_to_be32(j);
1327                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1328         }
1329         fmh->vol_count = cpu_to_be32(vol_count);
1330         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1331
1332         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1333         avhdr->lnum = 0;
1334
1335         spin_unlock(&ubi->wl_lock);
1336         spin_unlock(&ubi->volumes_lock);
1337
1338         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1339         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1340         if (ret) {
1341                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1342                 goto out_free_seen;
1343         }
1344
1345         for (i = 0; i < new_fm->used_blocks; i++) {
1346                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1347                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1348                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1349         }
1350
1351         fmsb->data_crc = 0;
1352         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1353                                            ubi->fm_size));
1354
1355         for (i = 1; i < new_fm->used_blocks; i++) {
1356                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1357                 dvhdr->lnum = cpu_to_be32(i);
1358                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1359                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1360                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1361                 if (ret) {
1362                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1363                                 new_fm->e[i]->pnum);
1364                         goto out_free_seen;
1365                 }
1366         }
1367
1368         for (i = 0; i < new_fm->used_blocks; i++) {
1369                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1370                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1371                 if (ret) {
1372                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1373                                 new_fm->e[i]->pnum);
1374                         goto out_free_seen;
1375                 }
1376         }
1377
1378         ubi_assert(new_fm);
1379         ubi->fm = new_fm;
1380
1381         ret = self_check_seen(ubi, seen_pebs);
1382         dbg_bld("fastmap written!");
1383
1384 out_free_seen:
1385         free_seen(seen_pebs);
1386 out_free_dvbuf:
1387         ubi_free_vid_buf(dvbuf);
1388 out_free_avbuf:
1389         ubi_free_vid_buf(avbuf);
1390
1391 out:
1392         return ret;
1393 }
1394
1395 /**
1396  * erase_block - Manually erase a PEB.
1397  * @ubi: UBI device object
1398  * @pnum: PEB to be erased
1399  *
1400  * Returns the new EC value on success, < 0 indicates an internal error.
1401  */
1402 static int erase_block(struct ubi_device *ubi, int pnum)
1403 {
1404         int ret;
1405         struct ubi_ec_hdr *ec_hdr;
1406         long long ec;
1407
1408         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1409         if (!ec_hdr)
1410                 return -ENOMEM;
1411
1412         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1413         if (ret < 0)
1414                 goto out;
1415         else if (ret && ret != UBI_IO_BITFLIPS) {
1416                 ret = -EINVAL;
1417                 goto out;
1418         }
1419
1420         ret = ubi_io_sync_erase(ubi, pnum, 0);
1421         if (ret < 0)
1422                 goto out;
1423
1424         ec = be64_to_cpu(ec_hdr->ec);
1425         ec += ret;
1426         if (ec > UBI_MAX_ERASECOUNTER) {
1427                 ret = -EINVAL;
1428                 goto out;
1429         }
1430
1431         ec_hdr->ec = cpu_to_be64(ec);
1432         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1433         if (ret < 0)
1434                 goto out;
1435
1436         ret = ec;
1437 out:
1438         kfree(ec_hdr);
1439         return ret;
1440 }
1441
1442 /**
1443  * invalidate_fastmap - destroys a fastmap.
1444  * @ubi: UBI device object
1445  *
1446  * This function ensures that upon next UBI attach a full scan
1447  * is issued. We need this if UBI is about to write a new fastmap
1448  * but is unable to do so. In this case we have two options:
1449  * a) Make sure that the current fastmap will not be usued upon
1450  * attach time and contine or b) fall back to RO mode to have the
1451  * current fastmap in a valid state.
1452  * Returns 0 on success, < 0 indicates an internal error.
1453  */
1454 static int invalidate_fastmap(struct ubi_device *ubi)
1455 {
1456         int ret;
1457         struct ubi_fastmap_layout *fm;
1458         struct ubi_wl_entry *e;
1459         struct ubi_vid_io_buf *vb = NULL;
1460         struct ubi_vid_hdr *vh;
1461
1462         if (!ubi->fm)
1463                 return 0;
1464
1465         ubi->fm = NULL;
1466
1467         ret = -ENOMEM;
1468         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1469         if (!fm)
1470                 goto out;
1471
1472         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1473         if (!vb)
1474                 goto out_free_fm;
1475
1476         vh = ubi_get_vid_hdr(vb);
1477
1478         ret = -ENOSPC;
1479         e = ubi_wl_get_fm_peb(ubi, 1);
1480         if (!e)
1481                 goto out_free_fm;
1482
1483         /*
1484          * Create fake fastmap such that UBI will fall back
1485          * to scanning mode.
1486          */
1487         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1488         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1489         if (ret < 0) {
1490                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1491                 goto out_free_fm;
1492         }
1493
1494         fm->used_blocks = 1;
1495         fm->e[0] = e;
1496
1497         ubi->fm = fm;
1498
1499 out:
1500         ubi_free_vid_buf(vb);
1501         return ret;
1502
1503 out_free_fm:
1504         kfree(fm);
1505         goto out;
1506 }
1507
1508 /**
1509  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1510  * WL sub-system.
1511  * @ubi: UBI device object
1512  * @fm: fastmap layout object
1513  */
1514 static void return_fm_pebs(struct ubi_device *ubi,
1515                            struct ubi_fastmap_layout *fm)
1516 {
1517         int i;
1518
1519         if (!fm)
1520                 return;
1521
1522         for (i = 0; i < fm->used_blocks; i++) {
1523                 if (fm->e[i]) {
1524                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1525                                           fm->to_be_tortured[i]);
1526                         fm->e[i] = NULL;
1527                 }
1528         }
1529 }
1530
1531 /**
1532  * ubi_update_fastmap - will be called by UBI if a volume changes or
1533  * a fastmap pool becomes full.
1534  * @ubi: UBI device object
1535  *
1536  * Returns 0 on success, < 0 indicates an internal error.
1537  */
1538 int ubi_update_fastmap(struct ubi_device *ubi)
1539 {
1540         int ret, i, j;
1541         struct ubi_fastmap_layout *new_fm, *old_fm;
1542         struct ubi_wl_entry *tmp_e;
1543
1544         down_write(&ubi->fm_protect);
1545         down_write(&ubi->work_sem);
1546         down_write(&ubi->fm_eba_sem);
1547
1548         ubi_refill_pools(ubi);
1549
1550         if (ubi->ro_mode || ubi->fm_disabled) {
1551                 up_write(&ubi->fm_eba_sem);
1552                 up_write(&ubi->work_sem);
1553                 up_write(&ubi->fm_protect);
1554                 return 0;
1555         }
1556
1557         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1558         if (!new_fm) {
1559                 up_write(&ubi->fm_eba_sem);
1560                 up_write(&ubi->work_sem);
1561                 up_write(&ubi->fm_protect);
1562                 return -ENOMEM;
1563         }
1564
1565         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1566         old_fm = ubi->fm;
1567         ubi->fm = NULL;
1568
1569         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1570                 ubi_err(ubi, "fastmap too large");
1571                 ret = -ENOSPC;
1572                 goto err;
1573         }
1574
1575         for (i = 1; i < new_fm->used_blocks; i++) {
1576                 spin_lock(&ubi->wl_lock);
1577                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1578                 spin_unlock(&ubi->wl_lock);
1579
1580                 if (!tmp_e) {
1581                         if (old_fm && old_fm->e[i]) {
1582                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1583                                 if (ret < 0) {
1584                                         ubi_err(ubi, "could not erase old fastmap PEB");
1585
1586                                         for (j = 1; j < i; j++) {
1587                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1588                                                                   j, 0);
1589                                                 new_fm->e[j] = NULL;
1590                                         }
1591                                         goto err;
1592                                 }
1593                                 new_fm->e[i] = old_fm->e[i];
1594                                 old_fm->e[i] = NULL;
1595                         } else {
1596                                 ubi_err(ubi, "could not get any free erase block");
1597
1598                                 for (j = 1; j < i; j++) {
1599                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1600                                         new_fm->e[j] = NULL;
1601                                 }
1602
1603                                 ret = -ENOSPC;
1604                                 goto err;
1605                         }
1606                 } else {
1607                         new_fm->e[i] = tmp_e;
1608
1609                         if (old_fm && old_fm->e[i]) {
1610                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1611                                                   old_fm->to_be_tortured[i]);
1612                                 old_fm->e[i] = NULL;
1613                         }
1614                 }
1615         }
1616
1617         /* Old fastmap is larger than the new one */
1618         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1619                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1620                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1621                                           old_fm->to_be_tortured[i]);
1622                         old_fm->e[i] = NULL;
1623                 }
1624         }
1625
1626         spin_lock(&ubi->wl_lock);
1627         tmp_e = ubi->fm_anchor;
1628         ubi->fm_anchor = NULL;
1629         spin_unlock(&ubi->wl_lock);
1630
1631         if (old_fm) {
1632                 /* no fresh anchor PEB was found, reuse the old one */
1633                 if (!tmp_e) {
1634                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1635                         if (ret < 0) {
1636                                 ubi_err(ubi, "could not erase old anchor PEB");
1637
1638                                 for (i = 1; i < new_fm->used_blocks; i++) {
1639                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1640                                                           i, 0);
1641                                         new_fm->e[i] = NULL;
1642                                 }
1643                                 goto err;
1644                         }
1645                         new_fm->e[0] = old_fm->e[0];
1646                         new_fm->e[0]->ec = ret;
1647                         old_fm->e[0] = NULL;
1648                 } else {
1649                         /* we've got a new anchor PEB, return the old one */
1650                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1651                                           old_fm->to_be_tortured[0]);
1652                         new_fm->e[0] = tmp_e;
1653                         old_fm->e[0] = NULL;
1654                 }
1655         } else {
1656                 if (!tmp_e) {
1657                         ubi_err(ubi, "could not find any anchor PEB");
1658
1659                         for (i = 1; i < new_fm->used_blocks; i++) {
1660                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1661                                 new_fm->e[i] = NULL;
1662                         }
1663
1664                         ret = -ENOSPC;
1665                         goto err;
1666                 }
1667                 new_fm->e[0] = tmp_e;
1668         }
1669
1670         ret = ubi_write_fastmap(ubi, new_fm);
1671
1672         if (ret)
1673                 goto err;
1674
1675 out_unlock:
1676         up_write(&ubi->fm_eba_sem);
1677         up_write(&ubi->work_sem);
1678         up_write(&ubi->fm_protect);
1679         kfree(old_fm);
1680
1681         ubi_ensure_anchor_pebs(ubi);
1682
1683         return ret;
1684
1685 err:
1686         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1687
1688         ret = invalidate_fastmap(ubi);
1689         if (ret < 0) {
1690                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1691                 ubi_ro_mode(ubi);
1692         } else {
1693                 return_fm_pebs(ubi, old_fm);
1694                 return_fm_pebs(ubi, new_fm);
1695                 ret = 0;
1696         }
1697
1698         kfree(new_fm);
1699         goto out_unlock;
1700 }