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_NOFS);
  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                   sizeof(struct ubi_fm_volhdr)) *
  90                  (UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT)) +
  91                 (ubi->peb_count * sizeof(__be32));
  92         return roundup(size, ubi->leb_size);
  93 }
  94
  95
  96 /**
  97  * new_fm_vbuf() - allocate a new volume header for fastmap usage.
  98  * @ubi: UBI device description object
  99  * @vol_id: the VID of the new header
 100  *
 101  * Returns a new struct ubi_vid_hdr on success.
 102  * NULL indicates out of memory.
 103  */
 104 static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 105 {
 106         struct ubi_vid_io_buf *new;
 107         struct ubi_vid_hdr *vh;
 108
 109         new = ubi_alloc_vid_buf(ubi, GFP_NOFS);
 110         if (!new)
 111                 goto out;
 112
 113         vh = ubi_get_vid_hdr(new);
 114         vh->vol_type = UBI_VID_DYNAMIC;
 115         vh->vol_id = cpu_to_be32(vol_id);
 116
 117         /* UBI implementations without fastmap support have to delete the
 118          * fastmap.
 119          */
 120         vh->compat = UBI_COMPAT_DELETE;
 121
 122 out:
 123         return new;
 124 }
 125
 126 /**
 127  * add_aeb - create and add a attach erase block to a given list.
 128  * @ai: UBI attach info object
 129  * @list: the target list
 130  * @pnum: PEB number of the new attach erase block
 131  * @ec: erease counter of the new LEB
 132  * @scrub: scrub this PEB after attaching
 133  *
 134  * Returns 0 on success, < 0 indicates an internal error.
 135  */
 136 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 137                    int pnum, int ec, int scrub)
 138 {
 139         struct ubi_ainf_peb *aeb;
 140
 141         aeb = ubi_alloc_aeb(ai, pnum, ec);
 142         if (!aeb)
 143                 return -ENOMEM;
 144
 145         aeb->lnum = -1;
 146         aeb->scrub = scrub;
 147         aeb->copy_flag = aeb->sqnum = 0;
 148
 149         ai->ec_sum += aeb->ec;
 150         ai->ec_count++;
 151
 152         if (ai->max_ec < aeb->ec)
 153                 ai->max_ec = aeb->ec;
 154
 155         if (ai->min_ec > aeb->ec)
 156                 ai->min_ec = aeb->ec;
 157
 158         list_add_tail(&aeb->u.list, list);
 159
 160         return 0;
 161 }
 162
 163 /**
 164  * add_vol - create and add a new volume to ubi_attach_info.
 165  * @ai: ubi_attach_info object
 166  * @vol_id: VID of the new volume
 167  * @used_ebs: number of used EBS
 168  * @data_pad: data padding value of the new volume
 169  * @vol_type: volume type
 170  * @last_eb_bytes: number of bytes in the last LEB
 171  *
 172  * Returns the new struct ubi_ainf_volume on success.
 173  * NULL indicates an error.
 174  */
 175 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 176                                        int used_ebs, int data_pad, u8 vol_type,
 177                                        int last_eb_bytes)
 178 {
 179         struct ubi_ainf_volume *av;
 180
 181         av = ubi_add_av(ai, vol_id);
 182         if (IS_ERR(av))
 183                 return av;
 184
 185         av->data_pad = data_pad;
 186         av->last_data_size = last_eb_bytes;
 187         av->compat = 0;
 188         av->vol_type = vol_type;
 189         if (av->vol_type == UBI_STATIC_VOLUME)
 190                 av->used_ebs = used_ebs;
 191
 192         dbg_bld("found volume (ID %i)", vol_id);
 193         return av;
 194 }
 195
 196 /**
 197  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 198  * from it's original list.
 199  * @ai: ubi_attach_info object
 200  * @aeb: the to be assigned SEB
 201  * @av: target scan volume
 202  */
 203 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 204                              struct ubi_ainf_peb *aeb,
 205                              struct ubi_ainf_volume *av)
 206 {
 207         struct ubi_ainf_peb *tmp_aeb;
 208         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 209
 210         while (*p) {
 211                 parent = *p;
 212
 213                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 214                 if (aeb->lnum != tmp_aeb->lnum) {
 215                         if (aeb->lnum < tmp_aeb->lnum)
 216                                 p = &(*p)->rb_left;
 217                         else
 218                                 p = &(*p)->rb_right;
 219
 220                         continue;
 221                 } else
 222                         break;
 223         }
 224
 225         list_del(&aeb->u.list);
 226         av->leb_count++;
 227
 228         rb_link_node(&aeb->u.rb, parent, p);
 229         rb_insert_color(&aeb->u.rb, &av->root);
 230 }
 231
 232 /**
 233  * update_vol - inserts or updates a LEB which was found a pool.
 234  * @ubi: the UBI device object
 235  * @ai: attach info object
 236  * @av: the volume this LEB belongs to
 237  * @new_vh: the volume header derived from new_aeb
 238  * @new_aeb: the AEB to be examined
 239  *
 240  * Returns 0 on success, < 0 indicates an internal error.
 241  */
 242 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 243                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 244                       struct ubi_ainf_peb *new_aeb)
 245 {
 246         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 247         struct ubi_ainf_peb *aeb, *victim;
 248         int cmp_res;
 249
 250         while (*p) {
 251                 parent = *p;
 252                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 253
 254                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 255                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 256                                 p = &(*p)->rb_left;
 257                         else
 258                                 p = &(*p)->rb_right;
 259
 260                         continue;
 261                 }
 262
 263                 /* This case can happen if the fastmap gets written
 264                  * because of a volume change (creation, deletion, ..).
 265                  * Then a PEB can be within the persistent EBA and the pool.
 266                  */
 267                 if (aeb->pnum == new_aeb->pnum) {
 268                         ubi_assert(aeb->lnum == new_aeb->lnum);
 269                         ubi_free_aeb(ai, new_aeb);
 270
 271                         return 0;
 272                 }
 273
 274                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 275                 if (cmp_res < 0)
 276                         return cmp_res;
 277
 278                 /* new_aeb is newer */
 279                 if (cmp_res & 1) {
 280                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 281                         if (!victim)
 282                                 return -ENOMEM;
 283
 284                         list_add_tail(&victim->u.list, &ai->erase);
 285
 286                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 287                                 av->last_data_size =
 288                                         be32_to_cpu(new_vh->data_size);
 289
 290                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 291                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 292
 293                         aeb->ec = new_aeb->ec;
 294                         aeb->pnum = new_aeb->pnum;
 295                         aeb->copy_flag = new_vh->copy_flag;
 296                         aeb->scrub = new_aeb->scrub;
 297                         aeb->sqnum = new_aeb->sqnum;
 298                         ubi_free_aeb(ai, new_aeb);
 299
 300                 /* new_aeb is older */
 301                 } else {
 302                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 303                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 304                         list_add_tail(&new_aeb->u.list, &ai->erase);
 305                 }
 306
 307                 return 0;
 308         }
 309         /* This LEB is new, let's add it to the volume */
 310
 311         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 312                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 313                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 314         }
 315
 316         if (av->vol_type == UBI_STATIC_VOLUME)
 317                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 318
 319         av->leb_count++;
 320
 321         rb_link_node(&new_aeb->u.rb, parent, p);
 322         rb_insert_color(&new_aeb->u.rb, &av->root);
 323
 324         return 0;
 325 }
 326
 327 /**
 328  * process_pool_aeb - we found a non-empty PEB in a pool.
 329  * @ubi: UBI device object
 330  * @ai: attach info object
 331  * @new_vh: the volume header derived from new_aeb
 332  * @new_aeb: the AEB to be examined
 333  *
 334  * Returns 0 on success, < 0 indicates an internal error.
 335  */
 336 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 337                             struct ubi_vid_hdr *new_vh,
 338                             struct ubi_ainf_peb *new_aeb)
 339 {
 340         int vol_id = be32_to_cpu(new_vh->vol_id);
 341         struct ubi_ainf_volume *av;
 342
 343         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 344                 ubi_free_aeb(ai, new_aeb);
 345
 346                 return 0;
 347         }
 348
 349         /* Find the volume this SEB belongs to */
 350         av = ubi_find_av(ai, vol_id);
 351         if (!av) {
 352                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 353                 ubi_free_aeb(ai, new_aeb);
 354                 return UBI_BAD_FASTMAP;
 355         }
 356
 357         ubi_assert(vol_id == av->vol_id);
 358
 359         return update_vol(ubi, ai, av, new_vh, new_aeb);
 360 }
 361
 362 /**
 363  * unmap_peb - unmap a PEB.
 364  * If fastmap detects a free PEB in the pool it has to check whether
 365  * this PEB has been unmapped after writing the fastmap.
 366  *
 367  * @ai: UBI attach info object
 368  * @pnum: The PEB to be unmapped
 369  */
 370 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 371 {
 372         struct ubi_ainf_volume *av;
 373         struct rb_node *node, *node2;
 374         struct ubi_ainf_peb *aeb;
 375
 376         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 377                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 378                         if (aeb->pnum == pnum) {
 379                                 rb_erase(&aeb->u.rb, &av->root);
 380                                 av->leb_count--;
 381                                 ubi_free_aeb(ai, aeb);
 382                                 return;
 383                         }
 384                 }
 385         }
 386 }
 387
 388 /**
 389  * scan_pool - scans a pool for changed (no longer empty PEBs).
 390  * @ubi: UBI device object
 391  * @ai: attach info object
 392  * @pebs: an array of all PEB numbers in the to be scanned pool
 393  * @pool_size: size of the pool (number of entries in @pebs)
 394  * @max_sqnum: pointer to the maximal sequence number
 395  * @free: list of PEBs which are most likely free (and go into @ai->free)
 396  *
 397  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 398  * < 0 indicates an internal error.
 399  */
 400 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 401                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 402                      struct list_head *free)
 403 {
 404         struct ubi_vid_io_buf *vb;
 405         struct ubi_vid_hdr *vh;
 406         struct ubi_ec_hdr *ech;
 407         struct ubi_ainf_peb *new_aeb;
 408         int i, pnum, err, ret = 0;
 409
 410         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 411         if (!ech)
 412                 return -ENOMEM;
 413
 414         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 415         if (!vb) {
 416                 kfree(ech);
 417                 return -ENOMEM;
 418         }
 419
 420         vh = ubi_get_vid_hdr(vb);
 421
 422         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 423
 424         /*
 425          * Now scan all PEBs in the pool to find changes which have been made
 426          * after the creation of the fastmap
 427          */
 428         for (i = 0; i < pool_size; i++) {
 429                 int scrub = 0;
 430                 int image_seq;
 431
 432                 pnum = be32_to_cpu(pebs[i]);
 433
 434                 if (ubi_io_is_bad(ubi, pnum)) {
 435                         ubi_err(ubi, "bad PEB in fastmap pool!");
 436                         ret = UBI_BAD_FASTMAP;
 437                         goto out;
 438                 }
 439
 440                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 441                 if (err && err != UBI_IO_BITFLIPS) {
 442                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 443                                 pnum, err);
 444                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 445                         goto out;
 446                 } else if (err == UBI_IO_BITFLIPS)
 447                         scrub = 1;
 448
 449                 /*
 450                  * Older UBI implementations have image_seq set to zero, so
 451                  * we shouldn't fail if image_seq == 0.
 452                  */
 453                 image_seq = be32_to_cpu(ech->image_seq);
 454
 455                 if (image_seq && (image_seq != ubi->image_seq)) {
 456                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 457                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 458                         ret = UBI_BAD_FASTMAP;
 459                         goto out;
 460                 }
 461
 462                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 463                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 464                         unsigned long long ec = be64_to_cpu(ech->ec);
 465                         unmap_peb(ai, pnum);
 466                         dbg_bld("Adding PEB to free: %i", pnum);
 467
 468                         if (err == UBI_IO_FF_BITFLIPS)
 469                                 scrub = 1;
 470
 471                         ret = add_aeb(ai, free, pnum, ec, scrub);
 472                         if (ret)
 473                                 goto out;
 474                         continue;
 475                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 476                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 477
 478                         if (err == UBI_IO_BITFLIPS)
 479                                 scrub = 1;
 480
 481                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 482                         if (!new_aeb) {
 483                                 ret = -ENOMEM;
 484                                 goto out;
 485                         }
 486
 487                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 488                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 489                         new_aeb->copy_flag = vh->copy_flag;
 490                         new_aeb->scrub = scrub;
 491
 492                         if (*max_sqnum < new_aeb->sqnum)
 493                                 *max_sqnum = new_aeb->sqnum;
 494
 495                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 496                         if (err) {
 497                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 498                                 goto out;
 499                         }
 500                 } else {
 501                         /* We are paranoid and fall back to scanning mode */
 502                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 503                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 504                         goto out;
 505                 }
 506
 507         }
 508
 509 out:
 510         ubi_free_vid_buf(vb);
 511         kfree(ech);
 512         return ret;
 513 }
 514
 515 /**
 516  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 517  * @ai: The UBI attach info object
 518  */
 519 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 520 {
 521         struct ubi_ainf_peb *aeb;
 522         struct ubi_ainf_volume *av;
 523         struct rb_node *rb1, *rb2;
 524         int n = 0;
 525
 526         list_for_each_entry(aeb, &ai->erase, u.list)
 527                 n++;
 528
 529         list_for_each_entry(aeb, &ai->free, u.list)
 530                 n++;
 531
 532         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 533                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 534                         n++;
 535
 536         return n;
 537 }
 538
 539 /**
 540  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 541  * @ubi: UBI device object
 542  * @ai: UBI attach info object
 543  * @fm: the fastmap to be attached
 544  *
 545  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 546  * < 0 indicates an internal error.
 547  */
 548 static int ubi_attach_fastmap(struct ubi_device *ubi,
 549                               struct ubi_attach_info *ai,
 550                               struct ubi_fastmap_layout *fm)
 551 {
 552         struct list_head used, free;
 553         struct ubi_ainf_volume *av;
 554         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 555         struct ubi_fm_sb *fmsb;
 556         struct ubi_fm_hdr *fmhdr;
 557         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 558         struct ubi_fm_ec *fmec;
 559         struct ubi_fm_volhdr *fmvhdr;
 560         struct ubi_fm_eba *fm_eba;
 561         int ret, i, j, pool_size, wl_pool_size;
 562         size_t fm_pos = 0, fm_size = ubi->fm_size;
 563         unsigned long long max_sqnum = 0;
 564         void *fm_raw = ubi->fm_buf;
 565
 566         INIT_LIST_HEAD(&used);
 567         INIT_LIST_HEAD(&free);
 568         ai->min_ec = UBI_MAX_ERASECOUNTER;
 569
 570         fmsb = (struct ubi_fm_sb *)(fm_raw);
 571         ai->max_sqnum = fmsb->sqnum;
 572         fm_pos += sizeof(struct ubi_fm_sb);
 573         if (fm_pos >= fm_size)
 574                 goto fail_bad;
 575
 576         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 577         fm_pos += sizeof(*fmhdr);
 578         if (fm_pos >= fm_size)
 579                 goto fail_bad;
 580
 581         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 582                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 583                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 584                 goto fail_bad;
 585         }
 586
 587         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 588         fm_pos += sizeof(*fmpl);
 589         if (fm_pos >= fm_size)
 590                 goto fail_bad;
 591         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 592                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 593                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 594                 goto fail_bad;
 595         }
 596
 597         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 598         fm_pos += sizeof(*fmpl_wl);
 599         if (fm_pos >= fm_size)
 600                 goto fail_bad;
 601         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 602                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 603                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 604                 goto fail_bad;
 605         }
 606
 607         pool_size = be16_to_cpu(fmpl->size);
 608         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 609         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 610         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 611
 612         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 613                 ubi_err(ubi, "bad pool size: %i", pool_size);
 614                 goto fail_bad;
 615         }
 616
 617         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 618                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 619                 goto fail_bad;
 620         }
 621
 622
 623         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 624             fm->max_pool_size < 0) {
 625                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 626                 goto fail_bad;
 627         }
 628
 629         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 630             fm->max_wl_pool_size < 0) {
 631                 ubi_err(ubi, "bad maximal WL pool size: %i",
 632                         fm->max_wl_pool_size);
 633                 goto fail_bad;
 634         }
 635
 636         /* read EC values from free list */
 637         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 638                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 639                 fm_pos += sizeof(*fmec);
 640                 if (fm_pos >= fm_size)
 641                         goto fail_bad;
 642
 643                 ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 644                               be32_to_cpu(fmec->ec), 0);
 645                 if (ret)
 646                         goto fail;
 647         }
 648
 649         /* read EC values from used list */
 650         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 651                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 652                 fm_pos += sizeof(*fmec);
 653                 if (fm_pos >= fm_size)
 654                         goto fail_bad;
 655
 656                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 657                               be32_to_cpu(fmec->ec), 0);
 658                 if (ret)
 659                         goto fail;
 660         }
 661
 662         /* read EC values from scrub list */
 663         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 664                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 665                 fm_pos += sizeof(*fmec);
 666                 if (fm_pos >= fm_size)
 667                         goto fail_bad;
 668
 669                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 670                               be32_to_cpu(fmec->ec), 1);
 671                 if (ret)
 672                         goto fail;
 673         }
 674
 675         /* read EC values from erase list */
 676         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 677                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 678                 fm_pos += sizeof(*fmec);
 679                 if (fm_pos >= fm_size)
 680                         goto fail_bad;
 681
 682                 ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 683                               be32_to_cpu(fmec->ec), 1);
 684                 if (ret)
 685                         goto fail;
 686         }
 687
 688         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 689         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 690
 691         /* Iterate over all volumes and read their EBA table */
 692         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 693                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 694                 fm_pos += sizeof(*fmvhdr);
 695                 if (fm_pos >= fm_size)
 696                         goto fail_bad;
 697
 698                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 699                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 700                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 701                         goto fail_bad;
 702                 }
 703
 704                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 705                              be32_to_cpu(fmvhdr->used_ebs),
 706                              be32_to_cpu(fmvhdr->data_pad),
 707                              fmvhdr->vol_type,
 708                              be32_to_cpu(fmvhdr->last_eb_bytes));
 709
 710                 if (IS_ERR(av)) {
 711                         if (PTR_ERR(av) == -EEXIST)
 712                                 ubi_err(ubi, "volume (ID %i) already exists",
 713                                         fmvhdr->vol_id);
 714
 715                         goto fail_bad;
 716                 }
 717
 718                 ai->vols_found++;
 719                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 720                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 721
 722                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 723                 fm_pos += sizeof(*fm_eba);
 724                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 725                 if (fm_pos >= fm_size)
 726                         goto fail_bad;
 727
 728                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 729                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 730                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 731                         goto fail_bad;
 732                 }
 733
 734                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 735                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 736
 737                         if (pnum < 0)
 738                                 continue;
 739
 740                         aeb = NULL;
 741                         list_for_each_entry(tmp_aeb, &used, u.list) {
 742                                 if (tmp_aeb->pnum == pnum) {
 743                                         aeb = tmp_aeb;
 744                                         break;
 745                                 }
 746                         }
 747
 748                         if (!aeb) {
 749                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 750                                 goto fail_bad;
 751                         }
 752
 753                         aeb->lnum = j;
 754
 755                         if (av->highest_lnum <= aeb->lnum)
 756                                 av->highest_lnum = aeb->lnum;
 757
 758                         assign_aeb_to_av(ai, aeb, av);
 759
 760                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 761                                 aeb->pnum, aeb->lnum, av->vol_id);
 762                 }
 763         }
 764
 765         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 766         if (ret)
 767                 goto fail;
 768
 769         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 770         if (ret)
 771                 goto fail;
 772
 773         if (max_sqnum > ai->max_sqnum)
 774                 ai->max_sqnum = max_sqnum;
 775
 776         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 777                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 778
 779         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 780                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 781
 782         ubi_assert(list_empty(&free));
 783
 784         /*
 785          * If fastmap is leaking PEBs (must not happen), raise a
 786          * fat warning and fall back to scanning mode.
 787          * We do this here because in ubi_wl_init() it's too late
 788          * and we cannot fall back to scanning.
 789          */
 790         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 791                     ai->bad_peb_count - fm->used_blocks))
 792                 goto fail_bad;
 793
 794         return 0;
 795
 796 fail_bad:
 797         ret = UBI_BAD_FASTMAP;
 798 fail:
 799         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 800                 list_del(&tmp_aeb->u.list);
 801                 ubi_free_aeb(ai, tmp_aeb);
 802         }
 803         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 804                 list_del(&tmp_aeb->u.list);
 805                 ubi_free_aeb(ai, tmp_aeb);
 806         }
 807
 808         return ret;
 809 }
 810
 811 /**
 812  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 813  * @ai: UBI attach info to be filled
 814  */
 815 static int find_fm_anchor(struct ubi_attach_info *ai)
 816 {
 817         int ret = -1;
 818         struct ubi_ainf_peb *aeb;
 819         unsigned long long max_sqnum = 0;
 820
 821         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 822                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 823                         max_sqnum = aeb->sqnum;
 824                         ret = aeb->pnum;
 825                 }
 826         }
 827
 828         return ret;
 829 }
 830
 831 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 832                                       struct ubi_ainf_peb *old)
 833 {
 834         struct ubi_ainf_peb *new;
 835
 836         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 837         if (!new)
 838                 return NULL;
 839
 840         new->vol_id = old->vol_id;
 841         new->sqnum = old->sqnum;
 842         new->lnum = old->lnum;
 843         new->scrub = old->scrub;
 844         new->copy_flag = old->copy_flag;
 845
 846         return new;
 847 }
 848
 849 /**
 850  * ubi_scan_fastmap - scan the fastmap.
 851  * @ubi: UBI device object
 852  * @ai: UBI attach info to be filled
 853  * @scan_ai: UBI attach info from the first 64 PEBs,
 854  *           used to find the most recent Fastmap data structure
 855  *
 856  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 857  * UBI_BAD_FASTMAP if one was found but is not usable.
 858  * < 0 indicates an internal error.
 859  */
 860 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 861                      struct ubi_attach_info *scan_ai)
 862 {
 863         struct ubi_fm_sb *fmsb, *fmsb2;
 864         struct ubi_vid_io_buf *vb;
 865         struct ubi_vid_hdr *vh;
 866         struct ubi_ec_hdr *ech;
 867         struct ubi_fastmap_layout *fm;
 868         struct ubi_ainf_peb *aeb;
 869         int i, used_blocks, pnum, fm_anchor, ret = 0;
 870         size_t fm_size;
 871         __be32 crc, tmp_crc;
 872         unsigned long long sqnum = 0;
 873
 874         fm_anchor = find_fm_anchor(scan_ai);
 875         if (fm_anchor < 0)
 876                 return UBI_NO_FASTMAP;
 877
 878         /* Copy all (possible) fastmap blocks into our new attach structure. */
 879         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 880                 struct ubi_ainf_peb *new;
 881
 882                 new = clone_aeb(ai, aeb);
 883                 if (!new)
 884                         return -ENOMEM;
 885
 886                 list_add(&new->u.list, &ai->fastmap);
 887         }
 888
 889         down_write(&ubi->fm_protect);
 890         memset(ubi->fm_buf, 0, ubi->fm_size);
 891
 892         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 893         if (!fmsb) {
 894                 ret = -ENOMEM;
 895                 goto out;
 896         }
 897
 898         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 899         if (!fm) {
 900                 ret = -ENOMEM;
 901                 kfree(fmsb);
 902                 goto out;
 903         }
 904
 905         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 906         if (ret && ret != UBI_IO_BITFLIPS)
 907                 goto free_fm_sb;
 908         else if (ret == UBI_IO_BITFLIPS)
 909                 fm->to_be_tortured[0] = 1;
 910
 911         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 912                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 913                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 914                 ret = UBI_BAD_FASTMAP;
 915                 goto free_fm_sb;
 916         }
 917
 918         if (fmsb->version != UBI_FM_FMT_VERSION) {
 919                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 920                         fmsb->version, UBI_FM_FMT_VERSION);
 921                 ret = UBI_BAD_FASTMAP;
 922                 goto free_fm_sb;
 923         }
 924
 925         used_blocks = be32_to_cpu(fmsb->used_blocks);
 926         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 927                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 928                         used_blocks);
 929                 ret = UBI_BAD_FASTMAP;
 930                 goto free_fm_sb;
 931         }
 932
 933         fm_size = ubi->leb_size * used_blocks;
 934         if (fm_size != ubi->fm_size) {
 935                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 936                         fm_size, ubi->fm_size);
 937                 ret = UBI_BAD_FASTMAP;
 938                 goto free_fm_sb;
 939         }
 940
 941         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 942         if (!ech) {
 943                 ret = -ENOMEM;
 944                 goto free_fm_sb;
 945         }
 946
 947         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 948         if (!vb) {
 949                 ret = -ENOMEM;
 950                 goto free_hdr;
 951         }
 952
 953         vh = ubi_get_vid_hdr(vb);
 954
 955         for (i = 0; i < used_blocks; i++) {
 956                 int image_seq;
 957
 958                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 959
 960                 if (ubi_io_is_bad(ubi, pnum)) {
 961                         ret = UBI_BAD_FASTMAP;
 962                         goto free_hdr;
 963                 }
 964
 965                 if (i == 0 && pnum != fm_anchor) {
 966                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 967                                 pnum, fm_anchor);
 968                         ret = UBI_BAD_FASTMAP;
 969                         goto free_hdr;
 970                 }
 971
 972                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 973                 if (ret && ret != UBI_IO_BITFLIPS) {
 974                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 975                                 i, pnum);
 976                         if (ret > 0)
 977                                 ret = UBI_BAD_FASTMAP;
 978                         goto free_hdr;
 979                 } else if (ret == UBI_IO_BITFLIPS)
 980                         fm->to_be_tortured[i] = 1;
 981
 982                 image_seq = be32_to_cpu(ech->image_seq);
 983                 if (!ubi->image_seq)
 984                         ubi->image_seq = image_seq;
 985
 986                 /*
 987                  * Older UBI implementations have image_seq set to zero, so
 988                  * we shouldn't fail if image_seq == 0.
 989                  */
 990                 if (image_seq && (image_seq != ubi->image_seq)) {
 991                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 992                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 993                         ret = UBI_BAD_FASTMAP;
 994                         goto free_hdr;
 995                 }
 996
 997                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 998                 if (ret && ret != UBI_IO_BITFLIPS) {
 999                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1000                                 i, pnum);
1001                         goto free_hdr;
1002                 }
1003
1004                 if (i == 0) {
1005                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1006                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1007                                         be32_to_cpu(vh->vol_id),
1008                                         UBI_FM_SB_VOLUME_ID);
1009                                 ret = UBI_BAD_FASTMAP;
1010                                 goto free_hdr;
1011                         }
1012                 } else {
1013                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1014                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1015                                         be32_to_cpu(vh->vol_id),
1016                                         UBI_FM_DATA_VOLUME_ID);
1017                                 ret = UBI_BAD_FASTMAP;
1018                                 goto free_hdr;
1019                         }
1020                 }
1021
1022                 if (sqnum < be64_to_cpu(vh->sqnum))
1023                         sqnum = be64_to_cpu(vh->sqnum);
1024
1025                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1026                                        pnum, 0, ubi->leb_size);
1027                 if (ret && ret != UBI_IO_BITFLIPS) {
1028                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1029                                 "err: %i)", i, pnum, ret);
1030                         goto free_hdr;
1031                 }
1032         }
1033
1034         kfree(fmsb);
1035         fmsb = NULL;
1036
1037         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1038         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1039         fmsb2->data_crc = 0;
1040         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1041         if (crc != tmp_crc) {
1042                 ubi_err(ubi, "fastmap data CRC is invalid");
1043                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1044                         tmp_crc, crc);
1045                 ret = UBI_BAD_FASTMAP;
1046                 goto free_hdr;
1047         }
1048
1049         fmsb2->sqnum = sqnum;
1050
1051         fm->used_blocks = used_blocks;
1052
1053         ret = ubi_attach_fastmap(ubi, ai, fm);
1054         if (ret) {
1055                 if (ret > 0)
1056                         ret = UBI_BAD_FASTMAP;
1057                 goto free_hdr;
1058         }
1059
1060         for (i = 0; i < used_blocks; i++) {
1061                 struct ubi_wl_entry *e;
1062
1063                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1064                 if (!e) {
1065                         while (i--)
1066                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1067
1068                         ret = -ENOMEM;
1069                         goto free_hdr;
1070                 }
1071
1072                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1073                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1074                 fm->e[i] = e;
1075         }
1076
1077         ubi->fm = fm;
1078         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1079         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1080         ubi_msg(ubi, "attached by fastmap");
1081         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1082         ubi_msg(ubi, "fastmap WL pool size: %d",
1083                 ubi->fm_wl_pool.max_size);
1084         ubi->fm_disabled = 0;
1085         ubi->fast_attach = 1;
1086
1087         ubi_free_vid_buf(vb);
1088         kfree(ech);
1089 out:
1090         up_write(&ubi->fm_protect);
1091         if (ret == UBI_BAD_FASTMAP)
1092                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1093         return ret;
1094
1095 free_hdr:
1096         ubi_free_vid_buf(vb);
1097         kfree(ech);
1098 free_fm_sb:
1099         kfree(fmsb);
1100         kfree(fm);
1101         goto out;
1102 }
1103
1104 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1105 {
1106         struct ubi_device *ubi = vol->ubi;
1107
1108         if (!ubi->fast_attach)
1109                 return 0;
1110
1111         vol->checkmap = bitmap_zalloc(leb_count, GFP_KERNEL);
1112         if (!vol->checkmap)
1113                 return -ENOMEM;
1114
1115         return 0;
1116 }
1117
1118 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1119 {
1120         bitmap_free(vol->checkmap);
1121 }
1122
1123 /**
1124  * ubi_write_fastmap - writes a fastmap.
1125  * @ubi: UBI device object
1126  * @new_fm: the to be written fastmap
1127  *
1128  * Returns 0 on success, < 0 indicates an internal error.
1129  */
1130 static int ubi_write_fastmap(struct ubi_device *ubi,
1131                              struct ubi_fastmap_layout *new_fm)
1132 {
1133         size_t fm_pos = 0;
1134         void *fm_raw;
1135         struct ubi_fm_sb *fmsb;
1136         struct ubi_fm_hdr *fmh;
1137         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1138         struct ubi_fm_ec *fec;
1139         struct ubi_fm_volhdr *fvh;
1140         struct ubi_fm_eba *feba;
1141         struct ubi_wl_entry *wl_e;
1142         struct ubi_volume *vol;
1143         struct ubi_vid_io_buf *avbuf, *dvbuf;
1144         struct ubi_vid_hdr *avhdr, *dvhdr;
1145         struct ubi_work *ubi_wrk;
1146         struct rb_node *tmp_rb;
1147         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1148         int scrub_peb_count, erase_peb_count;
1149         unsigned long *seen_pebs;
1150
1151         fm_raw = ubi->fm_buf;
1152         memset(ubi->fm_buf, 0, ubi->fm_size);
1153
1154         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1155         if (!avbuf) {
1156                 ret = -ENOMEM;
1157                 goto out;
1158         }
1159
1160         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1161         if (!dvbuf) {
1162                 ret = -ENOMEM;
1163                 goto out_free_avbuf;
1164         }
1165
1166         avhdr = ubi_get_vid_hdr(avbuf);
1167         dvhdr = ubi_get_vid_hdr(dvbuf);
1168
1169         seen_pebs = init_seen(ubi);
1170         if (IS_ERR(seen_pebs)) {
1171                 ret = PTR_ERR(seen_pebs);
1172                 goto out_free_dvbuf;
1173         }
1174
1175         spin_lock(&ubi->volumes_lock);
1176         spin_lock(&ubi->wl_lock);
1177
1178         fmsb = (struct ubi_fm_sb *)fm_raw;
1179         fm_pos += sizeof(*fmsb);
1180         ubi_assert(fm_pos <= ubi->fm_size);
1181
1182         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1183         fm_pos += sizeof(*fmh);
1184         ubi_assert(fm_pos <= ubi->fm_size);
1185
1186         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1187         fmsb->version = UBI_FM_FMT_VERSION;
1188         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1189         /* the max sqnum will be filled in while *reading* the fastmap */
1190         fmsb->sqnum = 0;
1191
1192         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1193         free_peb_count = 0;
1194         used_peb_count = 0;
1195         scrub_peb_count = 0;
1196         erase_peb_count = 0;
1197         vol_count = 0;
1198
1199         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1200         fm_pos += sizeof(*fmpl);
1201         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1202         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1203         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1204
1205         for (i = 0; i < ubi->fm_pool.size; i++) {
1206                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1207                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1208         }
1209
1210         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1211         fm_pos += sizeof(*fmpl_wl);
1212         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1213         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1214         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1215
1216         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1217                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1218                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1219         }
1220
1221         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1222                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1223
1224                 fec->pnum = cpu_to_be32(wl_e->pnum);
1225                 set_seen(ubi, wl_e->pnum, seen_pebs);
1226                 fec->ec = cpu_to_be32(wl_e->ec);
1227
1228                 free_peb_count++;
1229                 fm_pos += sizeof(*fec);
1230                 ubi_assert(fm_pos <= ubi->fm_size);
1231         }
1232         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1233
1234         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1235                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1236
1237                 fec->pnum = cpu_to_be32(wl_e->pnum);
1238                 set_seen(ubi, wl_e->pnum, seen_pebs);
1239                 fec->ec = cpu_to_be32(wl_e->ec);
1240
1241                 used_peb_count++;
1242                 fm_pos += sizeof(*fec);
1243                 ubi_assert(fm_pos <= ubi->fm_size);
1244         }
1245
1246         ubi_for_each_protected_peb(ubi, i, wl_e) {
1247                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1248
1249                 fec->pnum = cpu_to_be32(wl_e->pnum);
1250                 set_seen(ubi, wl_e->pnum, seen_pebs);
1251                 fec->ec = cpu_to_be32(wl_e->ec);
1252
1253                 used_peb_count++;
1254                 fm_pos += sizeof(*fec);
1255                 ubi_assert(fm_pos <= ubi->fm_size);
1256         }
1257         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1258
1259         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1260                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1261
1262                 fec->pnum = cpu_to_be32(wl_e->pnum);
1263                 set_seen(ubi, wl_e->pnum, seen_pebs);
1264                 fec->ec = cpu_to_be32(wl_e->ec);
1265
1266                 scrub_peb_count++;
1267                 fm_pos += sizeof(*fec);
1268                 ubi_assert(fm_pos <= ubi->fm_size);
1269         }
1270         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1271
1272
1273         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1274                 if (ubi_is_erase_work(ubi_wrk)) {
1275                         wl_e = ubi_wrk->e;
1276                         ubi_assert(wl_e);
1277
1278                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1279
1280                         fec->pnum = cpu_to_be32(wl_e->pnum);
1281                         set_seen(ubi, wl_e->pnum, seen_pebs);
1282                         fec->ec = cpu_to_be32(wl_e->ec);
1283
1284                         erase_peb_count++;
1285                         fm_pos += sizeof(*fec);
1286                         ubi_assert(fm_pos <= ubi->fm_size);
1287                 }
1288         }
1289         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1290
1291         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1292                 vol = ubi->volumes[i];
1293
1294                 if (!vol)
1295                         continue;
1296
1297                 vol_count++;
1298
1299                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1300                 fm_pos += sizeof(*fvh);
1301                 ubi_assert(fm_pos <= ubi->fm_size);
1302
1303                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1304                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1305                 fvh->vol_type = vol->vol_type;
1306                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1307                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1308                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1309
1310                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1311                         vol->vol_type == UBI_STATIC_VOLUME);
1312
1313                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1314                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1315                 ubi_assert(fm_pos <= ubi->fm_size);
1316
1317                 for (j = 0; j < vol->reserved_pebs; j++) {
1318                         struct ubi_eba_leb_desc ldesc;
1319
1320                         ubi_eba_get_ldesc(vol, j, &ldesc);
1321                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1322                 }
1323
1324                 feba->reserved_pebs = cpu_to_be32(j);
1325                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1326         }
1327         fmh->vol_count = cpu_to_be32(vol_count);
1328         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1329
1330         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1331         avhdr->lnum = 0;
1332
1333         spin_unlock(&ubi->wl_lock);
1334         spin_unlock(&ubi->volumes_lock);
1335
1336         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1337         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1338         if (ret) {
1339                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1340                 goto out_free_seen;
1341         }
1342
1343         for (i = 0; i < new_fm->used_blocks; i++) {
1344                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1345                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1346                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1347         }
1348
1349         fmsb->data_crc = 0;
1350         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1351                                            ubi->fm_size));
1352
1353         for (i = 1; i < new_fm->used_blocks; i++) {
1354                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1355                 dvhdr->lnum = cpu_to_be32(i);
1356                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1357                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1358                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1359                 if (ret) {
1360                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1361                                 new_fm->e[i]->pnum);
1362                         goto out_free_seen;
1363                 }
1364         }
1365
1366         for (i = 0; i < new_fm->used_blocks; i++) {
1367                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1368                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1369                 if (ret) {
1370                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1371                                 new_fm->e[i]->pnum);
1372                         goto out_free_seen;
1373                 }
1374         }
1375
1376         ubi_assert(new_fm);
1377         ubi->fm = new_fm;
1378
1379         ret = self_check_seen(ubi, seen_pebs);
1380         dbg_bld("fastmap written!");
1381
1382 out_free_seen:
1383         free_seen(seen_pebs);
1384 out_free_dvbuf:
1385         ubi_free_vid_buf(dvbuf);
1386 out_free_avbuf:
1387         ubi_free_vid_buf(avbuf);
1388
1389 out:
1390         return ret;
1391 }
1392
1393 /**
1394  * invalidate_fastmap - destroys a fastmap.
1395  * @ubi: UBI device object
1396  *
1397  * This function ensures that upon next UBI attach a full scan
1398  * is issued. We need this if UBI is about to write a new fastmap
1399  * but is unable to do so. In this case we have two options:
1400  * a) Make sure that the current fastmap will not be usued upon
1401  * attach time and contine or b) fall back to RO mode to have the
1402  * current fastmap in a valid state.
1403  * Returns 0 on success, < 0 indicates an internal error.
1404  */
1405 static int invalidate_fastmap(struct ubi_device *ubi)
1406 {
1407         int ret;
1408         struct ubi_fastmap_layout *fm;
1409         struct ubi_wl_entry *e;
1410         struct ubi_vid_io_buf *vb = NULL;
1411         struct ubi_vid_hdr *vh;
1412
1413         if (!ubi->fm)
1414                 return 0;
1415
1416         ubi->fm = NULL;
1417
1418         ret = -ENOMEM;
1419         fm = kzalloc(sizeof(*fm), GFP_NOFS);
1420         if (!fm)
1421                 goto out;
1422
1423         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1424         if (!vb)
1425                 goto out_free_fm;
1426
1427         vh = ubi_get_vid_hdr(vb);
1428
1429         ret = -ENOSPC;
1430         e = ubi_wl_get_fm_peb(ubi, 1);
1431         if (!e)
1432                 goto out_free_fm;
1433
1434         /*
1435          * Create fake fastmap such that UBI will fall back
1436          * to scanning mode.
1437          */
1438         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1439         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1440         if (ret < 0) {
1441                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1442                 goto out_free_fm;
1443         }
1444
1445         fm->used_blocks = 1;
1446         fm->e[0] = e;
1447
1448         ubi->fm = fm;
1449
1450 out:
1451         ubi_free_vid_buf(vb);
1452         return ret;
1453
1454 out_free_fm:
1455         kfree(fm);
1456         goto out;
1457 }
1458
1459 /**
1460  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1461  * WL sub-system.
1462  * @ubi: UBI device object
1463  * @fm: fastmap layout object
1464  */
1465 static void return_fm_pebs(struct ubi_device *ubi,
1466                            struct ubi_fastmap_layout *fm)
1467 {
1468         int i;
1469
1470         if (!fm)
1471                 return;
1472
1473         for (i = 0; i < fm->used_blocks; i++) {
1474                 if (fm->e[i]) {
1475                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1476                                           fm->to_be_tortured[i]);
1477                         fm->e[i] = NULL;
1478                 }
1479         }
1480 }
1481
1482 /**
1483  * ubi_update_fastmap - will be called by UBI if a volume changes or
1484  * a fastmap pool becomes full.
1485  * @ubi: UBI device object
1486  *
1487  * Returns 0 on success, < 0 indicates an internal error.
1488  */
1489 int ubi_update_fastmap(struct ubi_device *ubi)
1490 {
1491         int ret, i, j;
1492         struct ubi_fastmap_layout *new_fm, *old_fm;
1493         struct ubi_wl_entry *tmp_e;
1494
1495         ubi_refill_pools_and_lock(ubi);
1496
1497         if (ubi->ro_mode || ubi->fm_disabled) {
1498                 up_write(&ubi->fm_eba_sem);
1499                 up_write(&ubi->work_sem);
1500                 up_write(&ubi->fm_protect);
1501                 return 0;
1502         }
1503
1504         new_fm = kzalloc(sizeof(*new_fm), GFP_NOFS);
1505         if (!new_fm) {
1506                 up_write(&ubi->fm_eba_sem);
1507                 up_write(&ubi->work_sem);
1508                 up_write(&ubi->fm_protect);
1509                 return -ENOMEM;
1510         }
1511
1512         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1513         old_fm = ubi->fm;
1514         ubi->fm = NULL;
1515
1516         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1517                 ubi_err(ubi, "fastmap too large");
1518                 ret = -ENOSPC;
1519                 goto err;
1520         }
1521
1522         for (i = 1; i < new_fm->used_blocks; i++) {
1523                 spin_lock(&ubi->wl_lock);
1524                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1525                 spin_unlock(&ubi->wl_lock);
1526
1527                 if (!tmp_e) {
1528                         if (old_fm && old_fm->e[i]) {
1529                                 ret = ubi_sync_erase(ubi, old_fm->e[i], 0);
1530                                 if (ret < 0) {
1531                                         ubi_err(ubi, "could not erase old fastmap PEB");
1532
1533                                         for (j = 1; j < i; j++) {
1534                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1535                                                                   j, 0);
1536                                                 new_fm->e[j] = NULL;
1537                                         }
1538                                         goto err;
1539                                 }
1540                                 new_fm->e[i] = old_fm->e[i];
1541                                 old_fm->e[i] = NULL;
1542                         } else {
1543                                 ubi_err(ubi, "could not get any free erase block");
1544
1545                                 for (j = 1; j < i; j++) {
1546                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1547                                         new_fm->e[j] = NULL;
1548                                 }
1549
1550                                 ret = -ENOSPC;
1551                                 goto err;
1552                         }
1553                 } else {
1554                         new_fm->e[i] = tmp_e;
1555
1556                         if (old_fm && old_fm->e[i]) {
1557                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1558                                                   old_fm->to_be_tortured[i]);
1559                                 old_fm->e[i] = NULL;
1560                         }
1561                 }
1562         }
1563
1564         /* Old fastmap is larger than the new one */
1565         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1566                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1567                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1568                                           old_fm->to_be_tortured[i]);
1569                         old_fm->e[i] = NULL;
1570                 }
1571         }
1572
1573         spin_lock(&ubi->wl_lock);
1574         tmp_e = ubi->fm_anchor;
1575         ubi->fm_anchor = NULL;
1576         spin_unlock(&ubi->wl_lock);
1577
1578         if (old_fm) {
1579                 /* no fresh anchor PEB was found, reuse the old one */
1580                 if (!tmp_e) {
1581                         ret = ubi_sync_erase(ubi, old_fm->e[0], 0);
1582                         if (ret < 0) {
1583                                 ubi_err(ubi, "could not erase old anchor PEB");
1584
1585                                 for (i = 1; i < new_fm->used_blocks; i++) {
1586                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1587                                                           i, 0);
1588                                         new_fm->e[i] = NULL;
1589                                 }
1590                                 goto err;
1591                         }
1592                         new_fm->e[0] = old_fm->e[0];
1593                         old_fm->e[0] = NULL;
1594                 } else {
1595                         /* we've got a new anchor PEB, return the old one */
1596                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1597                                           old_fm->to_be_tortured[0]);
1598                         new_fm->e[0] = tmp_e;
1599                         old_fm->e[0] = NULL;
1600                 }
1601         } else {
1602                 if (!tmp_e) {
1603                         ubi_err(ubi, "could not find any anchor PEB");
1604
1605                         for (i = 1; i < new_fm->used_blocks; i++) {
1606                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1607                                 new_fm->e[i] = NULL;
1608                         }
1609
1610                         ret = -ENOSPC;
1611                         goto err;
1612                 }
1613                 new_fm->e[0] = tmp_e;
1614         }
1615
1616         ret = ubi_write_fastmap(ubi, new_fm);
1617
1618         if (ret)
1619                 goto err;
1620
1621 out_unlock:
1622         up_write(&ubi->fm_eba_sem);
1623         up_write(&ubi->work_sem);
1624         up_write(&ubi->fm_protect);
1625         kfree(old_fm);
1626
1627         ubi_ensure_anchor_pebs(ubi);
1628
1629         return ret;
1630
1631 err:
1632         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1633
1634         ret = invalidate_fastmap(ubi);
1635         if (ret < 0) {
1636                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1637                 ubi_ro_mode(ubi);
1638         } else {
1639                 return_fm_pebs(ubi, old_fm);
1640                 return_fm_pebs(ubi, new_fm);
1641                 ret = 0;
1642         }
1643
1644         kfree(new_fm);
1645         goto out_unlock;
1646 }