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                 (ubi->peb_count * sizeof(__be32))) +
  91                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  92         return roundup(size, ubi->leb_size);
  93 }
  94
  95
  96 /**
  97  * new_fm_vhdr - 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_KERNEL);
 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                         add_aeb(ai, free, pnum, ec, scrub);
 472                         continue;
 473                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 474                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 475
 476                         if (err == UBI_IO_BITFLIPS)
 477                                 scrub = 1;
 478
 479                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 480                         if (!new_aeb) {
 481                                 ret = -ENOMEM;
 482                                 goto out;
 483                         }
 484
 485                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 486                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 487                         new_aeb->copy_flag = vh->copy_flag;
 488                         new_aeb->scrub = scrub;
 489
 490                         if (*max_sqnum < new_aeb->sqnum)
 491                                 *max_sqnum = new_aeb->sqnum;
 492
 493                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 494                         if (err) {
 495                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 496                                 goto out;
 497                         }
 498                 } else {
 499                         /* We are paranoid and fall back to scanning mode */
 500                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 501                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 502                         goto out;
 503                 }
 504
 505         }
 506
 507 out:
 508         ubi_free_vid_buf(vb);
 509         kfree(ech);
 510         return ret;
 511 }
 512
 513 /**
 514  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 515  * @ai: The UBI attach info object
 516  */
 517 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 518 {
 519         struct ubi_ainf_peb *aeb;
 520         struct ubi_ainf_volume *av;
 521         struct rb_node *rb1, *rb2;
 522         int n = 0;
 523
 524         list_for_each_entry(aeb, &ai->erase, u.list)
 525                 n++;
 526
 527         list_for_each_entry(aeb, &ai->free, u.list)
 528                 n++;
 529
 530         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 531                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 532                         n++;
 533
 534         return n;
 535 }
 536
 537 /**
 538  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 539  * @ubi: UBI device object
 540  * @ai: UBI attach info object
 541  * @fm: the fastmap to be attached
 542  *
 543  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 544  * < 0 indicates an internal error.
 545  */
 546 static int ubi_attach_fastmap(struct ubi_device *ubi,
 547                               struct ubi_attach_info *ai,
 548                               struct ubi_fastmap_layout *fm)
 549 {
 550         struct list_head used, free;
 551         struct ubi_ainf_volume *av;
 552         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 553         struct ubi_fm_sb *fmsb;
 554         struct ubi_fm_hdr *fmhdr;
 555         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 556         struct ubi_fm_ec *fmec;
 557         struct ubi_fm_volhdr *fmvhdr;
 558         struct ubi_fm_eba *fm_eba;
 559         int ret, i, j, pool_size, wl_pool_size;
 560         size_t fm_pos = 0, fm_size = ubi->fm_size;
 561         unsigned long long max_sqnum = 0;
 562         void *fm_raw = ubi->fm_buf;
 563
 564         INIT_LIST_HEAD(&used);
 565         INIT_LIST_HEAD(&free);
 566         ai->min_ec = UBI_MAX_ERASECOUNTER;
 567
 568         fmsb = (struct ubi_fm_sb *)(fm_raw);
 569         ai->max_sqnum = fmsb->sqnum;
 570         fm_pos += sizeof(struct ubi_fm_sb);
 571         if (fm_pos >= fm_size)
 572                 goto fail_bad;
 573
 574         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 575         fm_pos += sizeof(*fmhdr);
 576         if (fm_pos >= fm_size)
 577                 goto fail_bad;
 578
 579         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 580                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 581                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 582                 goto fail_bad;
 583         }
 584
 585         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 586         fm_pos += sizeof(*fmpl);
 587         if (fm_pos >= fm_size)
 588                 goto fail_bad;
 589         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 590                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 591                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 592                 goto fail_bad;
 593         }
 594
 595         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 596         fm_pos += sizeof(*fmpl_wl);
 597         if (fm_pos >= fm_size)
 598                 goto fail_bad;
 599         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 600                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 601                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 602                 goto fail_bad;
 603         }
 604
 605         pool_size = be16_to_cpu(fmpl->size);
 606         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 607         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 608         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 609
 610         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 611                 ubi_err(ubi, "bad pool size: %i", pool_size);
 612                 goto fail_bad;
 613         }
 614
 615         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 616                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 617                 goto fail_bad;
 618         }
 619
 620
 621         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 622             fm->max_pool_size < 0) {
 623                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 624                 goto fail_bad;
 625         }
 626
 627         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 628             fm->max_wl_pool_size < 0) {
 629                 ubi_err(ubi, "bad maximal WL pool size: %i",
 630                         fm->max_wl_pool_size);
 631                 goto fail_bad;
 632         }
 633
 634         /* read EC values from free list */
 635         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 636                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 637                 fm_pos += sizeof(*fmec);
 638                 if (fm_pos >= fm_size)
 639                         goto fail_bad;
 640
 641                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 642                         be32_to_cpu(fmec->ec), 0);
 643         }
 644
 645         /* read EC values from used list */
 646         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 647                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 648                 fm_pos += sizeof(*fmec);
 649                 if (fm_pos >= fm_size)
 650                         goto fail_bad;
 651
 652                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 653                         be32_to_cpu(fmec->ec), 0);
 654         }
 655
 656         /* read EC values from scrub list */
 657         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 658                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 659                 fm_pos += sizeof(*fmec);
 660                 if (fm_pos >= fm_size)
 661                         goto fail_bad;
 662
 663                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 664                         be32_to_cpu(fmec->ec), 1);
 665         }
 666
 667         /* read EC values from erase list */
 668         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 669                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 670                 fm_pos += sizeof(*fmec);
 671                 if (fm_pos >= fm_size)
 672                         goto fail_bad;
 673
 674                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 675                         be32_to_cpu(fmec->ec), 1);
 676         }
 677
 678         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 679         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 680
 681         /* Iterate over all volumes and read their EBA table */
 682         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 683                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 684                 fm_pos += sizeof(*fmvhdr);
 685                 if (fm_pos >= fm_size)
 686                         goto fail_bad;
 687
 688                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 689                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 690                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 691                         goto fail_bad;
 692                 }
 693
 694                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 695                              be32_to_cpu(fmvhdr->used_ebs),
 696                              be32_to_cpu(fmvhdr->data_pad),
 697                              fmvhdr->vol_type,
 698                              be32_to_cpu(fmvhdr->last_eb_bytes));
 699
 700                 if (IS_ERR(av)) {
 701                         if (PTR_ERR(av) == -EEXIST)
 702                                 ubi_err(ubi, "volume (ID %i) already exists",
 703                                         fmvhdr->vol_id);
 704
 705                         goto fail_bad;
 706                 }
 707
 708                 ai->vols_found++;
 709                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 710                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 711
 712                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 713                 fm_pos += sizeof(*fm_eba);
 714                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 715                 if (fm_pos >= fm_size)
 716                         goto fail_bad;
 717
 718                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 719                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 720                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 721                         goto fail_bad;
 722                 }
 723
 724                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 725                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 726
 727                         if (pnum < 0)
 728                                 continue;
 729
 730                         aeb = NULL;
 731                         list_for_each_entry(tmp_aeb, &used, u.list) {
 732                                 if (tmp_aeb->pnum == pnum) {
 733                                         aeb = tmp_aeb;
 734                                         break;
 735                                 }
 736                         }
 737
 738                         if (!aeb) {
 739                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 740                                 goto fail_bad;
 741                         }
 742
 743                         aeb->lnum = j;
 744
 745                         if (av->highest_lnum <= aeb->lnum)
 746                                 av->highest_lnum = aeb->lnum;
 747
 748                         assign_aeb_to_av(ai, aeb, av);
 749
 750                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 751                                 aeb->pnum, aeb->lnum, av->vol_id);
 752                 }
 753         }
 754
 755         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 756         if (ret)
 757                 goto fail;
 758
 759         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 760         if (ret)
 761                 goto fail;
 762
 763         if (max_sqnum > ai->max_sqnum)
 764                 ai->max_sqnum = max_sqnum;
 765
 766         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 767                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 768
 769         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 770                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 771
 772         ubi_assert(list_empty(&free));
 773
 774         /*
 775          * If fastmap is leaking PEBs (must not happen), raise a
 776          * fat warning and fall back to scanning mode.
 777          * We do this here because in ubi_wl_init() it's too late
 778          * and we cannot fall back to scanning.
 779          */
 780         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 781                     ai->bad_peb_count - fm->used_blocks))
 782                 goto fail_bad;
 783
 784         return 0;
 785
 786 fail_bad:
 787         ret = UBI_BAD_FASTMAP;
 788 fail:
 789         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 790                 list_del(&tmp_aeb->u.list);
 791                 ubi_free_aeb(ai, tmp_aeb);
 792         }
 793         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 794                 list_del(&tmp_aeb->u.list);
 795                 ubi_free_aeb(ai, tmp_aeb);
 796         }
 797
 798         return ret;
 799 }
 800
 801 /**
 802  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 803  * @ai: UBI attach info to be filled
 804  */
 805 static int find_fm_anchor(struct ubi_attach_info *ai)
 806 {
 807         int ret = -1;
 808         struct ubi_ainf_peb *aeb;
 809         unsigned long long max_sqnum = 0;
 810
 811         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 812                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 813                         max_sqnum = aeb->sqnum;
 814                         ret = aeb->pnum;
 815                 }
 816         }
 817
 818         return ret;
 819 }
 820
 821 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 822                                       struct ubi_ainf_peb *old)
 823 {
 824         struct ubi_ainf_peb *new;
 825
 826         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 827         if (!new)
 828                 return NULL;
 829
 830         new->vol_id = old->vol_id;
 831         new->sqnum = old->sqnum;
 832         new->lnum = old->lnum;
 833         new->scrub = old->scrub;
 834         new->copy_flag = old->copy_flag;
 835
 836         return new;
 837 }
 838
 839 /**
 840  * ubi_scan_fastmap - scan the fastmap.
 841  * @ubi: UBI device object
 842  * @ai: UBI attach info to be filled
 843  * @scan_ai: UBI attach info from the first 64 PEBs,
 844  *           used to find the most recent Fastmap data structure
 845  *
 846  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 847  * UBI_BAD_FASTMAP if one was found but is not usable.
 848  * < 0 indicates an internal error.
 849  */
 850 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 851                      struct ubi_attach_info *scan_ai)
 852 {
 853         struct ubi_fm_sb *fmsb, *fmsb2;
 854         struct ubi_vid_io_buf *vb;
 855         struct ubi_vid_hdr *vh;
 856         struct ubi_ec_hdr *ech;
 857         struct ubi_fastmap_layout *fm;
 858         struct ubi_ainf_peb *aeb;
 859         int i, used_blocks, pnum, fm_anchor, ret = 0;
 860         size_t fm_size;
 861         __be32 crc, tmp_crc;
 862         unsigned long long sqnum = 0;
 863
 864         fm_anchor = find_fm_anchor(scan_ai);
 865         if (fm_anchor < 0)
 866                 return UBI_NO_FASTMAP;
 867
 868         /* Copy all (possible) fastmap blocks into our new attach structure. */
 869         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 870                 struct ubi_ainf_peb *new;
 871
 872                 new = clone_aeb(ai, aeb);
 873                 if (!new)
 874                         return -ENOMEM;
 875
 876                 list_add(&new->u.list, &ai->fastmap);
 877         }
 878
 879         down_write(&ubi->fm_protect);
 880         memset(ubi->fm_buf, 0, ubi->fm_size);
 881
 882         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 883         if (!fmsb) {
 884                 ret = -ENOMEM;
 885                 goto out;
 886         }
 887
 888         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 889         if (!fm) {
 890                 ret = -ENOMEM;
 891                 kfree(fmsb);
 892                 goto out;
 893         }
 894
 895         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 896         if (ret && ret != UBI_IO_BITFLIPS)
 897                 goto free_fm_sb;
 898         else if (ret == UBI_IO_BITFLIPS)
 899                 fm->to_be_tortured[0] = 1;
 900
 901         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 902                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 903                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 904                 ret = UBI_BAD_FASTMAP;
 905                 goto free_fm_sb;
 906         }
 907
 908         if (fmsb->version != UBI_FM_FMT_VERSION) {
 909                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 910                         fmsb->version, UBI_FM_FMT_VERSION);
 911                 ret = UBI_BAD_FASTMAP;
 912                 goto free_fm_sb;
 913         }
 914
 915         used_blocks = be32_to_cpu(fmsb->used_blocks);
 916         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 917                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 918                         used_blocks);
 919                 ret = UBI_BAD_FASTMAP;
 920                 goto free_fm_sb;
 921         }
 922
 923         fm_size = ubi->leb_size * used_blocks;
 924         if (fm_size != ubi->fm_size) {
 925                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 926                         fm_size, ubi->fm_size);
 927                 ret = UBI_BAD_FASTMAP;
 928                 goto free_fm_sb;
 929         }
 930
 931         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 932         if (!ech) {
 933                 ret = -ENOMEM;
 934                 goto free_fm_sb;
 935         }
 936
 937         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 938         if (!vb) {
 939                 ret = -ENOMEM;
 940                 goto free_hdr;
 941         }
 942
 943         vh = ubi_get_vid_hdr(vb);
 944
 945         for (i = 0; i < used_blocks; i++) {
 946                 int image_seq;
 947
 948                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 949
 950                 if (ubi_io_is_bad(ubi, pnum)) {
 951                         ret = UBI_BAD_FASTMAP;
 952                         goto free_hdr;
 953                 }
 954
 955                 if (i == 0 && pnum != fm_anchor) {
 956                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 957                                 pnum, fm_anchor);
 958                         ret = UBI_BAD_FASTMAP;
 959                         goto free_hdr;
 960                 }
 961
 962                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 963                 if (ret && ret != UBI_IO_BITFLIPS) {
 964                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 965                                 i, pnum);
 966                         if (ret > 0)
 967                                 ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 } else if (ret == UBI_IO_BITFLIPS)
 970                         fm->to_be_tortured[i] = 1;
 971
 972                 image_seq = be32_to_cpu(ech->image_seq);
 973                 if (!ubi->image_seq)
 974                         ubi->image_seq = image_seq;
 975
 976                 /*
 977                  * Older UBI implementations have image_seq set to zero, so
 978                  * we shouldn't fail if image_seq == 0.
 979                  */
 980                 if (image_seq && (image_seq != ubi->image_seq)) {
 981                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 982                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 983                         ret = UBI_BAD_FASTMAP;
 984                         goto free_hdr;
 985                 }
 986
 987                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 988                 if (ret && ret != UBI_IO_BITFLIPS) {
 989                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 990                                 i, pnum);
 991                         goto free_hdr;
 992                 }
 993
 994                 if (i == 0) {
 995                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 996                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 997                                         be32_to_cpu(vh->vol_id),
 998                                         UBI_FM_SB_VOLUME_ID);
 999                                 ret = UBI_BAD_FASTMAP;
1000                                 goto free_hdr;
1001                         }
1002                 } else {
1003                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1004                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1005                                         be32_to_cpu(vh->vol_id),
1006                                         UBI_FM_DATA_VOLUME_ID);
1007                                 ret = UBI_BAD_FASTMAP;
1008                                 goto free_hdr;
1009                         }
1010                 }
1011
1012                 if (sqnum < be64_to_cpu(vh->sqnum))
1013                         sqnum = be64_to_cpu(vh->sqnum);
1014
1015                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1016                                        pnum, 0, ubi->leb_size);
1017                 if (ret && ret != UBI_IO_BITFLIPS) {
1018                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1019                                 "err: %i)", i, pnum, ret);
1020                         goto free_hdr;
1021                 }
1022         }
1023
1024         kfree(fmsb);
1025         fmsb = NULL;
1026
1027         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1028         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1029         fmsb2->data_crc = 0;
1030         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1031         if (crc != tmp_crc) {
1032                 ubi_err(ubi, "fastmap data CRC is invalid");
1033                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1034                         tmp_crc, crc);
1035                 ret = UBI_BAD_FASTMAP;
1036                 goto free_hdr;
1037         }
1038
1039         fmsb2->sqnum = sqnum;
1040
1041         fm->used_blocks = used_blocks;
1042
1043         ret = ubi_attach_fastmap(ubi, ai, fm);
1044         if (ret) {
1045                 if (ret > 0)
1046                         ret = UBI_BAD_FASTMAP;
1047                 goto free_hdr;
1048         }
1049
1050         for (i = 0; i < used_blocks; i++) {
1051                 struct ubi_wl_entry *e;
1052
1053                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1054                 if (!e) {
1055                         while (i--)
1056                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1057
1058                         ret = -ENOMEM;
1059                         goto free_hdr;
1060                 }
1061
1062                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1063                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1064                 fm->e[i] = e;
1065         }
1066
1067         ubi->fm = fm;
1068         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1069         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1070         ubi_msg(ubi, "attached by fastmap");
1071         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1072         ubi_msg(ubi, "fastmap WL pool size: %d",
1073                 ubi->fm_wl_pool.max_size);
1074         ubi->fm_disabled = 0;
1075         ubi->fast_attach = 1;
1076
1077         ubi_free_vid_buf(vb);
1078         kfree(ech);
1079 out:
1080         up_write(&ubi->fm_protect);
1081         if (ret == UBI_BAD_FASTMAP)
1082                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1083         return ret;
1084
1085 free_hdr:
1086         ubi_free_vid_buf(vb);
1087         kfree(ech);
1088 free_fm_sb:
1089         kfree(fmsb);
1090         kfree(fm);
1091         goto out;
1092 }
1093
1094 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1095 {
1096         struct ubi_device *ubi = vol->ubi;
1097
1098         if (!ubi->fast_attach)
1099                 return 0;
1100
1101         vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
1102                                 GFP_KERNEL);
1103         if (!vol->checkmap)
1104                 return -ENOMEM;
1105
1106         return 0;
1107 }
1108
1109 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1110 {
1111         kfree(vol->checkmap);
1112 }
1113
1114 /**
1115  * ubi_write_fastmap - writes a fastmap.
1116  * @ubi: UBI device object
1117  * @new_fm: the to be written fastmap
1118  *
1119  * Returns 0 on success, < 0 indicates an internal error.
1120  */
1121 static int ubi_write_fastmap(struct ubi_device *ubi,
1122                              struct ubi_fastmap_layout *new_fm)
1123 {
1124         size_t fm_pos = 0;
1125         void *fm_raw;
1126         struct ubi_fm_sb *fmsb;
1127         struct ubi_fm_hdr *fmh;
1128         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1129         struct ubi_fm_ec *fec;
1130         struct ubi_fm_volhdr *fvh;
1131         struct ubi_fm_eba *feba;
1132         struct ubi_wl_entry *wl_e;
1133         struct ubi_volume *vol;
1134         struct ubi_vid_io_buf *avbuf, *dvbuf;
1135         struct ubi_vid_hdr *avhdr, *dvhdr;
1136         struct ubi_work *ubi_wrk;
1137         struct rb_node *tmp_rb;
1138         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1139         int scrub_peb_count, erase_peb_count;
1140         unsigned long *seen_pebs;
1141
1142         fm_raw = ubi->fm_buf;
1143         memset(ubi->fm_buf, 0, ubi->fm_size);
1144
1145         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1146         if (!avbuf) {
1147                 ret = -ENOMEM;
1148                 goto out;
1149         }
1150
1151         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1152         if (!dvbuf) {
1153                 ret = -ENOMEM;
1154                 goto out_free_avbuf;
1155         }
1156
1157         avhdr = ubi_get_vid_hdr(avbuf);
1158         dvhdr = ubi_get_vid_hdr(dvbuf);
1159
1160         seen_pebs = init_seen(ubi);
1161         if (IS_ERR(seen_pebs)) {
1162                 ret = PTR_ERR(seen_pebs);
1163                 goto out_free_dvbuf;
1164         }
1165
1166         spin_lock(&ubi->volumes_lock);
1167         spin_lock(&ubi->wl_lock);
1168
1169         fmsb = (struct ubi_fm_sb *)fm_raw;
1170         fm_pos += sizeof(*fmsb);
1171         ubi_assert(fm_pos <= ubi->fm_size);
1172
1173         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1174         fm_pos += sizeof(*fmh);
1175         ubi_assert(fm_pos <= ubi->fm_size);
1176
1177         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1178         fmsb->version = UBI_FM_FMT_VERSION;
1179         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1180         /* the max sqnum will be filled in while *reading* the fastmap */
1181         fmsb->sqnum = 0;
1182
1183         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1184         free_peb_count = 0;
1185         used_peb_count = 0;
1186         scrub_peb_count = 0;
1187         erase_peb_count = 0;
1188         vol_count = 0;
1189
1190         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1191         fm_pos += sizeof(*fmpl);
1192         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1193         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1194         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1195
1196         for (i = 0; i < ubi->fm_pool.size; i++) {
1197                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1198                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1199         }
1200
1201         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1202         fm_pos += sizeof(*fmpl_wl);
1203         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1204         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1205         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1206
1207         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1208                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1209                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1210         }
1211
1212         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1213                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1214
1215                 fec->pnum = cpu_to_be32(wl_e->pnum);
1216                 set_seen(ubi, wl_e->pnum, seen_pebs);
1217                 fec->ec = cpu_to_be32(wl_e->ec);
1218
1219                 free_peb_count++;
1220                 fm_pos += sizeof(*fec);
1221                 ubi_assert(fm_pos <= ubi->fm_size);
1222         }
1223         if (ubi->fm_next_anchor) {
1224                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1225
1226                 fec->pnum = cpu_to_be32(ubi->fm_next_anchor->pnum);
1227                 set_seen(ubi, ubi->fm_next_anchor->pnum, seen_pebs);
1228                 fec->ec = cpu_to_be32(ubi->fm_next_anchor->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 }