drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Copyright (c) 2014 sigma star gmbh
   4  * Author: Richard Weinberger <richard@nod.at>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/crc32.h>
  18 #include <linux/bitmap.h>
  19 #include "ubi.h"
  20
  21 /**
  22  * init_seen - allocate memory for used for debugging.
  23  * @ubi: UBI device description object
  24  */
  25 static inline unsigned long *init_seen(struct ubi_device *ubi)
  26 {
  27         unsigned long *ret;
  28
  29         if (!ubi_dbg_chk_fastmap(ubi))
  30                 return NULL;
  31
  32         ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  33                       GFP_KERNEL);
  34         if (!ret)
  35                 return ERR_PTR(-ENOMEM);
  36
  37         return ret;
  38 }
  39
  40 /**
  41  * free_seen - free the seen logic integer array.
  42  * @seen: integer array of @ubi->peb_count size
  43  */
  44 static inline void free_seen(unsigned long *seen)
  45 {
  46         kfree(seen);
  47 }
  48
  49 /**
  50  * set_seen - mark a PEB as seen.
  51  * @ubi: UBI device description object
  52  * @pnum: The PEB to be makred as seen
  53  * @seen: integer array of @ubi->peb_count size
  54  */
  55 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  56 {
  57         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  58                 return;
  59
  60         set_bit(pnum, seen);
  61 }
  62
  63 /**
  64  * self_check_seen - check whether all PEB have been seen by fastmap.
  65  * @ubi: UBI device description object
  66  * @seen: integer array of @ubi->peb_count size
  67  */
  68 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  69 {
  70         int pnum, ret = 0;
  71
  72         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  73                 return 0;
  74
  75         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  76                 if (test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  77                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  78                         ret = -EINVAL;
  79                 }
  80         }
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  87  * @ubi: UBI device description object
  88  */
  89 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  90 {
  91         size_t size;
  92
  93         size = sizeof(struct ubi_fm_sb) +
  94                 sizeof(struct ubi_fm_hdr) +
  95                 sizeof(struct ubi_fm_scan_pool) +
  96                 sizeof(struct ubi_fm_scan_pool) +
  97                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  98                 (sizeof(struct ubi_fm_eba) +
  99                 (ubi->peb_count * sizeof(__be32))) +
 100                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
 101         return roundup(size, ubi->leb_size);
 102 }
 103
 104
 105 /**
 106  * new_fm_vhdr - allocate a new volume header for fastmap usage.
 107  * @ubi: UBI device description object
 108  * @vol_id: the VID of the new header
 109  *
 110  * Returns a new struct ubi_vid_hdr on success.
 111  * NULL indicates out of memory.
 112  */
 113 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
 114 {
 115         struct ubi_vid_hdr *new;
 116
 117         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 118         if (!new)
 119                 goto out;
 120
 121         new->vol_type = UBI_VID_DYNAMIC;
 122         new->vol_id = cpu_to_be32(vol_id);
 123
 124         /* UBI implementations without fastmap support have to delete the
 125          * fastmap.
 126          */
 127         new->compat = UBI_COMPAT_DELETE;
 128
 129 out:
 130         return new;
 131 }
 132
 133 /**
 134  * add_aeb - create and add a attach erase block to a given list.
 135  * @ai: UBI attach info object
 136  * @list: the target list
 137  * @pnum: PEB number of the new attach erase block
 138  * @ec: erease counter of the new LEB
 139  * @scrub: scrub this PEB after attaching
 140  *
 141  * Returns 0 on success, < 0 indicates an internal error.
 142  */
 143 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 144                    int pnum, int ec, int scrub)
 145 {
 146         struct ubi_ainf_peb *aeb;
 147
 148         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
 149         if (!aeb)
 150                 return -ENOMEM;
 151
 152         aeb->pnum = pnum;
 153         aeb->ec = ec;
 154         aeb->lnum = -1;
 155         aeb->scrub = scrub;
 156         aeb->copy_flag = aeb->sqnum = 0;
 157
 158         ai->ec_sum += aeb->ec;
 159         ai->ec_count++;
 160
 161         if (ai->max_ec < aeb->ec)
 162                 ai->max_ec = aeb->ec;
 163
 164         if (ai->min_ec > aeb->ec)
 165                 ai->min_ec = aeb->ec;
 166
 167         list_add_tail(&aeb->u.list, list);
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * add_vol - create and add a new volume to ubi_attach_info.
 174  * @ai: ubi_attach_info object
 175  * @vol_id: VID of the new volume
 176  * @used_ebs: number of used EBS
 177  * @data_pad: data padding value of the new volume
 178  * @vol_type: volume type
 179  * @last_eb_bytes: number of bytes in the last LEB
 180  *
 181  * Returns the new struct ubi_ainf_volume on success.
 182  * NULL indicates an error.
 183  */
 184 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 185                                        int used_ebs, int data_pad, u8 vol_type,
 186                                        int last_eb_bytes)
 187 {
 188         struct ubi_ainf_volume *av;
 189         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 190
 191         while (*p) {
 192                 parent = *p;
 193                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 194
 195                 if (vol_id > av->vol_id)
 196                         p = &(*p)->rb_left;
 197                 else if (vol_id < av->vol_id)
 198                         p = &(*p)->rb_right;
 199                 else
 200                         return ERR_PTR(-EINVAL);
 201         }
 202
 203         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 204         if (!av)
 205                 goto out;
 206
 207         av->highest_lnum = av->leb_count = av->used_ebs = 0;
 208         av->vol_id = vol_id;
 209         av->data_pad = data_pad;
 210         av->last_data_size = last_eb_bytes;
 211         av->compat = 0;
 212         av->vol_type = vol_type;
 213         av->root = RB_ROOT;
 214         if (av->vol_type == UBI_STATIC_VOLUME)
 215                 av->used_ebs = used_ebs;
 216
 217         dbg_bld("found volume (ID %i)", vol_id);
 218
 219         rb_link_node(&av->rb, parent, p);
 220         rb_insert_color(&av->rb, &ai->volumes);
 221
 222 out:
 223         return av;
 224 }
 225
 226 /**
 227  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 228  * from it's original list.
 229  * @ai: ubi_attach_info object
 230  * @aeb: the to be assigned SEB
 231  * @av: target scan volume
 232  */
 233 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 234                              struct ubi_ainf_peb *aeb,
 235                              struct ubi_ainf_volume *av)
 236 {
 237         struct ubi_ainf_peb *tmp_aeb;
 238         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 239
 240         p = &av->root.rb_node;
 241         while (*p) {
 242                 parent = *p;
 243
 244                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 245                 if (aeb->lnum != tmp_aeb->lnum) {
 246                         if (aeb->lnum < tmp_aeb->lnum)
 247                                 p = &(*p)->rb_left;
 248                         else
 249                                 p = &(*p)->rb_right;
 250
 251                         continue;
 252                 } else
 253                         break;
 254         }
 255
 256         list_del(&aeb->u.list);
 257         av->leb_count++;
 258
 259         rb_link_node(&aeb->u.rb, parent, p);
 260         rb_insert_color(&aeb->u.rb, &av->root);
 261 }
 262
 263 /**
 264  * update_vol - inserts or updates a LEB which was found a pool.
 265  * @ubi: the UBI device object
 266  * @ai: attach info object
 267  * @av: the volume this LEB belongs to
 268  * @new_vh: the volume header derived from new_aeb
 269  * @new_aeb: the AEB to be examined
 270  *
 271  * Returns 0 on success, < 0 indicates an internal error.
 272  */
 273 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 274                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 275                       struct ubi_ainf_peb *new_aeb)
 276 {
 277         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 278         struct ubi_ainf_peb *aeb, *victim;
 279         int cmp_res;
 280
 281         while (*p) {
 282                 parent = *p;
 283                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 284
 285                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 286                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 287                                 p = &(*p)->rb_left;
 288                         else
 289                                 p = &(*p)->rb_right;
 290
 291                         continue;
 292                 }
 293
 294                 /* This case can happen if the fastmap gets written
 295                  * because of a volume change (creation, deletion, ..).
 296                  * Then a PEB can be within the persistent EBA and the pool.
 297                  */
 298                 if (aeb->pnum == new_aeb->pnum) {
 299                         ubi_assert(aeb->lnum == new_aeb->lnum);
 300                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 301
 302                         return 0;
 303                 }
 304
 305                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 306                 if (cmp_res < 0)
 307                         return cmp_res;
 308
 309                 /* new_aeb is newer */
 310                 if (cmp_res & 1) {
 311                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 312                                 GFP_KERNEL);
 313                         if (!victim)
 314                                 return -ENOMEM;
 315
 316                         victim->ec = aeb->ec;
 317                         victim->pnum = aeb->pnum;
 318                         list_add_tail(&victim->u.list, &ai->erase);
 319
 320                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 321                                 av->last_data_size =
 322                                         be32_to_cpu(new_vh->data_size);
 323
 324                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 325                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 326
 327                         aeb->ec = new_aeb->ec;
 328                         aeb->pnum = new_aeb->pnum;
 329                         aeb->copy_flag = new_vh->copy_flag;
 330                         aeb->scrub = new_aeb->scrub;
 331                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 332
 333                 /* new_aeb is older */
 334                 } else {
 335                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 336                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 337                         list_add_tail(&new_aeb->u.list, &ai->erase);
 338                 }
 339
 340                 return 0;
 341         }
 342         /* This LEB is new, let's add it to the volume */
 343
 344         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 345                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 346                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 347         }
 348
 349         if (av->vol_type == UBI_STATIC_VOLUME)
 350                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 351
 352         av->leb_count++;
 353
 354         rb_link_node(&new_aeb->u.rb, parent, p);
 355         rb_insert_color(&new_aeb->u.rb, &av->root);
 356
 357         return 0;
 358 }
 359
 360 /**
 361  * process_pool_aeb - we found a non-empty PEB in a pool.
 362  * @ubi: UBI device object
 363  * @ai: attach info object
 364  * @new_vh: the volume header derived from new_aeb
 365  * @new_aeb: the AEB to be examined
 366  *
 367  * Returns 0 on success, < 0 indicates an internal error.
 368  */
 369 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 370                             struct ubi_vid_hdr *new_vh,
 371                             struct ubi_ainf_peb *new_aeb)
 372 {
 373         struct ubi_ainf_volume *av, *tmp_av = NULL;
 374         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 375         int found = 0;
 376
 377         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 378                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 379                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 380
 381                 return 0;
 382         }
 383
 384         /* Find the volume this SEB belongs to */
 385         while (*p) {
 386                 parent = *p;
 387                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 388
 389                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 390                         p = &(*p)->rb_left;
 391                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 392                         p = &(*p)->rb_right;
 393                 else {
 394                         found = 1;
 395                         break;
 396                 }
 397         }
 398
 399         if (found)
 400                 av = tmp_av;
 401         else {
 402                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 403                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 404                 return UBI_BAD_FASTMAP;
 405         }
 406
 407         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 408
 409         return update_vol(ubi, ai, av, new_vh, new_aeb);
 410 }
 411
 412 /**
 413  * unmap_peb - unmap a PEB.
 414  * If fastmap detects a free PEB in the pool it has to check whether
 415  * this PEB has been unmapped after writing the fastmap.
 416  *
 417  * @ai: UBI attach info object
 418  * @pnum: The PEB to be unmapped
 419  */
 420 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 421 {
 422         struct ubi_ainf_volume *av;
 423         struct rb_node *node, *node2;
 424         struct ubi_ainf_peb *aeb;
 425
 426         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 427                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 428
 429                 for (node2 = rb_first(&av->root); node2;
 430                      node2 = rb_next(node2)) {
 431                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 432                         if (aeb->pnum == pnum) {
 433                                 rb_erase(&aeb->u.rb, &av->root);
 434                                 av->leb_count--;
 435                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 436                                 return;
 437                         }
 438                 }
 439         }
 440 }
 441
 442 /**
 443  * scan_pool - scans a pool for changed (no longer empty PEBs).
 444  * @ubi: UBI device object
 445  * @ai: attach info object
 446  * @pebs: an array of all PEB numbers in the to be scanned pool
 447  * @pool_size: size of the pool (number of entries in @pebs)
 448  * @max_sqnum: pointer to the maximal sequence number
 449  * @free: list of PEBs which are most likely free (and go into @ai->free)
 450  *
 451  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 452  * < 0 indicates an internal error.
 453  */
 454 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 455                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 456                      struct list_head *free)
 457 {
 458         struct ubi_vid_hdr *vh;
 459         struct ubi_ec_hdr *ech;
 460         struct ubi_ainf_peb *new_aeb;
 461         int i, pnum, err, ret = 0;
 462
 463         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 464         if (!ech)
 465                 return -ENOMEM;
 466
 467         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 468         if (!vh) {
 469                 kfree(ech);
 470                 return -ENOMEM;
 471         }
 472
 473         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 474
 475         /*
 476          * Now scan all PEBs in the pool to find changes which have been made
 477          * after the creation of the fastmap
 478          */
 479         for (i = 0; i < pool_size; i++) {
 480                 int scrub = 0;
 481                 int image_seq;
 482
 483                 pnum = be32_to_cpu(pebs[i]);
 484
 485                 if (ubi_io_is_bad(ubi, pnum)) {
 486                         ubi_err(ubi, "bad PEB in fastmap pool!");
 487                         ret = UBI_BAD_FASTMAP;
 488                         goto out;
 489                 }
 490
 491                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 492                 if (err && err != UBI_IO_BITFLIPS) {
 493                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 494                                 pnum, err);
 495                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 496                         goto out;
 497                 } else if (err == UBI_IO_BITFLIPS)
 498                         scrub = 1;
 499
 500                 /*
 501                  * Older UBI implementations have image_seq set to zero, so
 502                  * we shouldn't fail if image_seq == 0.
 503                  */
 504                 image_seq = be32_to_cpu(ech->image_seq);
 505
 506                 if (image_seq && (image_seq != ubi->image_seq)) {
 507                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 508                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 509                         ret = UBI_BAD_FASTMAP;
 510                         goto out;
 511                 }
 512
 513                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 514                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 515                         unsigned long long ec = be64_to_cpu(ech->ec);
 516                         unmap_peb(ai, pnum);
 517                         dbg_bld("Adding PEB to free: %i", pnum);
 518                         if (err == UBI_IO_FF_BITFLIPS)
 519                                 add_aeb(ai, free, pnum, ec, 1);
 520                         else
 521                                 add_aeb(ai, free, pnum, ec, 0);
 522                         continue;
 523                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 524                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 525
 526                         if (err == UBI_IO_BITFLIPS)
 527                                 scrub = 1;
 528
 529                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 530                                                    GFP_KERNEL);
 531                         if (!new_aeb) {
 532                                 ret = -ENOMEM;
 533                                 goto out;
 534                         }
 535
 536                         new_aeb->ec = be64_to_cpu(ech->ec);
 537                         new_aeb->pnum = pnum;
 538                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 539                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 540                         new_aeb->copy_flag = vh->copy_flag;
 541                         new_aeb->scrub = scrub;
 542
 543                         if (*max_sqnum < new_aeb->sqnum)
 544                                 *max_sqnum = new_aeb->sqnum;
 545
 546                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 547                         if (err) {
 548                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 549                                 goto out;
 550                         }
 551                 } else {
 552                         /* We are paranoid and fall back to scanning mode */
 553                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 554                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 555                         goto out;
 556                 }
 557
 558         }
 559
 560 out:
 561         ubi_free_vid_hdr(ubi, vh);
 562         kfree(ech);
 563         return ret;
 564 }
 565
 566 /**
 567  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 568  * @ai: The UBI attach info object
 569  */
 570 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 571 {
 572         struct ubi_ainf_peb *aeb;
 573         struct ubi_ainf_volume *av;
 574         struct rb_node *rb1, *rb2;
 575         int n = 0;
 576
 577         list_for_each_entry(aeb, &ai->erase, u.list)
 578                 n++;
 579
 580         list_for_each_entry(aeb, &ai->free, u.list)
 581                 n++;
 582
 583         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 584                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 585                         n++;
 586
 587         return n;
 588 }
 589
 590 /**
 591  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 592  * @ubi: UBI device object
 593  * @ai: UBI attach info object
 594  * @fm: the fastmap to be attached
 595  *
 596  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 597  * < 0 indicates an internal error.
 598  */
 599 static int ubi_attach_fastmap(struct ubi_device *ubi,
 600                               struct ubi_attach_info *ai,
 601                               struct ubi_fastmap_layout *fm)
 602 {
 603         struct list_head used, free;
 604         struct ubi_ainf_volume *av;
 605         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 606         struct ubi_fm_sb *fmsb;
 607         struct ubi_fm_hdr *fmhdr;
 608         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 609         struct ubi_fm_ec *fmec;
 610         struct ubi_fm_volhdr *fmvhdr;
 611         struct ubi_fm_eba *fm_eba;
 612         int ret, i, j, pool_size, wl_pool_size;
 613         size_t fm_pos = 0, fm_size = ubi->fm_size;
 614         unsigned long long max_sqnum = 0;
 615         void *fm_raw = ubi->fm_buf;
 616
 617         INIT_LIST_HEAD(&used);
 618         INIT_LIST_HEAD(&free);
 619         ai->min_ec = UBI_MAX_ERASECOUNTER;
 620
 621         fmsb = (struct ubi_fm_sb *)(fm_raw);
 622         ai->max_sqnum = fmsb->sqnum;
 623         fm_pos += sizeof(struct ubi_fm_sb);
 624         if (fm_pos >= fm_size)
 625                 goto fail_bad;
 626
 627         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 628         fm_pos += sizeof(*fmhdr);
 629         if (fm_pos >= fm_size)
 630                 goto fail_bad;
 631
 632         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 633                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 634                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 635                 goto fail_bad;
 636         }
 637
 638         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 639         fm_pos += sizeof(*fmpl);
 640         if (fm_pos >= fm_size)
 641                 goto fail_bad;
 642         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 643                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 644                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 645                 goto fail_bad;
 646         }
 647
 648         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 649         fm_pos += sizeof(*fmpl_wl);
 650         if (fm_pos >= fm_size)
 651                 goto fail_bad;
 652         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 653                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 654                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 655                 goto fail_bad;
 656         }
 657
 658         pool_size = be16_to_cpu(fmpl->size);
 659         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 660         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 661         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 662
 663         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 664                 ubi_err(ubi, "bad pool size: %i", pool_size);
 665                 goto fail_bad;
 666         }
 667
 668         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 669                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 670                 goto fail_bad;
 671         }
 672
 673
 674         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 675             fm->max_pool_size < 0) {
 676                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 677                 goto fail_bad;
 678         }
 679
 680         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 681             fm->max_wl_pool_size < 0) {
 682                 ubi_err(ubi, "bad maximal WL pool size: %i",
 683                         fm->max_wl_pool_size);
 684                 goto fail_bad;
 685         }
 686
 687         /* read EC values from free list */
 688         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 689                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 690                 fm_pos += sizeof(*fmec);
 691                 if (fm_pos >= fm_size)
 692                         goto fail_bad;
 693
 694                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 695                         be32_to_cpu(fmec->ec), 0);
 696         }
 697
 698         /* read EC values from used list */
 699         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 700                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 701                 fm_pos += sizeof(*fmec);
 702                 if (fm_pos >= fm_size)
 703                         goto fail_bad;
 704
 705                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 706                         be32_to_cpu(fmec->ec), 0);
 707         }
 708
 709         /* read EC values from scrub list */
 710         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 711                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 712                 fm_pos += sizeof(*fmec);
 713                 if (fm_pos >= fm_size)
 714                         goto fail_bad;
 715
 716                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 717                         be32_to_cpu(fmec->ec), 1);
 718         }
 719
 720         /* read EC values from erase list */
 721         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 722                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 723                 fm_pos += sizeof(*fmec);
 724                 if (fm_pos >= fm_size)
 725                         goto fail_bad;
 726
 727                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 728                         be32_to_cpu(fmec->ec), 1);
 729         }
 730
 731         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 732         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 733
 734         /* Iterate over all volumes and read their EBA table */
 735         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 736                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 737                 fm_pos += sizeof(*fmvhdr);
 738                 if (fm_pos >= fm_size)
 739                         goto fail_bad;
 740
 741                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 742                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 743                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 744                         goto fail_bad;
 745                 }
 746
 747                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 748                              be32_to_cpu(fmvhdr->used_ebs),
 749                              be32_to_cpu(fmvhdr->data_pad),
 750                              fmvhdr->vol_type,
 751                              be32_to_cpu(fmvhdr->last_eb_bytes));
 752
 753                 if (!av)
 754                         goto fail_bad;
 755                 if (PTR_ERR(av) == -EINVAL) {
 756                         ubi_err(ubi, "volume (ID %i) already exists",
 757                                 fmvhdr->vol_id);
 758                         goto fail_bad;
 759                 }
 760
 761                 ai->vols_found++;
 762                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 763                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 764
 765                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 766                 fm_pos += sizeof(*fm_eba);
 767                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 768                 if (fm_pos >= fm_size)
 769                         goto fail_bad;
 770
 771                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 772                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 773                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 774                         goto fail_bad;
 775                 }
 776
 777                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 778                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 779
 780                         if (pnum < 0)
 781                                 continue;
 782
 783                         aeb = NULL;
 784                         list_for_each_entry(tmp_aeb, &used, u.list) {
 785                                 if (tmp_aeb->pnum == pnum) {
 786                                         aeb = tmp_aeb;
 787                                         break;
 788                                 }
 789                         }
 790
 791                         if (!aeb) {
 792                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 793                                 goto fail_bad;
 794                         }
 795
 796                         aeb->lnum = j;
 797
 798                         if (av->highest_lnum <= aeb->lnum)
 799                                 av->highest_lnum = aeb->lnum;
 800
 801                         assign_aeb_to_av(ai, aeb, av);
 802
 803                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 804                                 aeb->pnum, aeb->lnum, av->vol_id);
 805                 }
 806         }
 807
 808         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 809         if (ret)
 810                 goto fail;
 811
 812         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 813         if (ret)
 814                 goto fail;
 815
 816         if (max_sqnum > ai->max_sqnum)
 817                 ai->max_sqnum = max_sqnum;
 818
 819         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 820                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 821
 822         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 823                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 824
 825         ubi_assert(list_empty(&free));
 826
 827         /*
 828          * If fastmap is leaking PEBs (must not happen), raise a
 829          * fat warning and fall back to scanning mode.
 830          * We do this here because in ubi_wl_init() it's too late
 831          * and we cannot fall back to scanning.
 832          */
 833         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 834                     ai->bad_peb_count - fm->used_blocks))
 835                 goto fail_bad;
 836
 837         return 0;
 838
 839 fail_bad:
 840         ret = UBI_BAD_FASTMAP;
 841 fail:
 842         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 843                 list_del(&tmp_aeb->u.list);
 844                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 845         }
 846         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 847                 list_del(&tmp_aeb->u.list);
 848                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 849         }
 850
 851         return ret;
 852 }
 853
 854 /**
 855  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 856  * @ai: UBI attach info to be filled
 857  */
 858 static int find_fm_anchor(struct ubi_attach_info *ai)
 859 {
 860         int ret = -1;
 861         struct ubi_ainf_peb *aeb;
 862         unsigned long long max_sqnum = 0;
 863
 864         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 865                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 866                         max_sqnum = aeb->sqnum;
 867                         ret = aeb->pnum;
 868                 }
 869         }
 870
 871         return ret;
 872 }
 873
 874 /**
 875  * ubi_scan_fastmap - scan the fastmap.
 876  * @ubi: UBI device object
 877  * @ai: UBI attach info to be filled
 878  * @scan_ai: UBI attach info from the first 64 PEBs,
 879  *           used to find the most recent Fastmap data structure
 880  *
 881  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 882  * UBI_BAD_FASTMAP if one was found but is not usable.
 883  * < 0 indicates an internal error.
 884  */
 885 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 886                      struct ubi_attach_info *scan_ai)
 887 {
 888         struct ubi_fm_sb *fmsb, *fmsb2;
 889         struct ubi_vid_hdr *vh;
 890         struct ubi_ec_hdr *ech;
 891         struct ubi_fastmap_layout *fm;
 892         struct ubi_ainf_peb *tmp_aeb, *aeb;
 893         int i, used_blocks, pnum, fm_anchor, ret = 0;
 894         size_t fm_size;
 895         __be32 crc, tmp_crc;
 896         unsigned long long sqnum = 0;
 897
 898         fm_anchor = find_fm_anchor(scan_ai);
 899         if (fm_anchor < 0)
 900                 return UBI_NO_FASTMAP;
 901
 902         /* Move all (possible) fastmap blocks into our new attach structure. */
 903         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 904                 list_move_tail(&aeb->u.list, &ai->fastmap);
 905
 906         down_write(&ubi->fm_protect);
 907         memset(ubi->fm_buf, 0, ubi->fm_size);
 908
 909         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 910         if (!fmsb) {
 911                 ret = -ENOMEM;
 912                 goto out;
 913         }
 914
 915         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 916         if (!fm) {
 917                 ret = -ENOMEM;
 918                 kfree(fmsb);
 919                 goto out;
 920         }
 921
 922         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 923         if (ret && ret != UBI_IO_BITFLIPS)
 924                 goto free_fm_sb;
 925         else if (ret == UBI_IO_BITFLIPS)
 926                 fm->to_be_tortured[0] = 1;
 927
 928         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 929                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 930                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 931                 ret = UBI_BAD_FASTMAP;
 932                 goto free_fm_sb;
 933         }
 934
 935         if (fmsb->version != UBI_FM_FMT_VERSION) {
 936                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 937                         fmsb->version, UBI_FM_FMT_VERSION);
 938                 ret = UBI_BAD_FASTMAP;
 939                 goto free_fm_sb;
 940         }
 941
 942         used_blocks = be32_to_cpu(fmsb->used_blocks);
 943         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 944                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 945                         used_blocks);
 946                 ret = UBI_BAD_FASTMAP;
 947                 goto free_fm_sb;
 948         }
 949
 950         fm_size = ubi->leb_size * used_blocks;
 951         if (fm_size != ubi->fm_size) {
 952                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 953                         fm_size, ubi->fm_size);
 954                 ret = UBI_BAD_FASTMAP;
 955                 goto free_fm_sb;
 956         }
 957
 958         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 959         if (!ech) {
 960                 ret = -ENOMEM;
 961                 goto free_fm_sb;
 962         }
 963
 964         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 965         if (!vh) {
 966                 ret = -ENOMEM;
 967                 goto free_hdr;
 968         }
 969
 970         for (i = 0; i < used_blocks; i++) {
 971                 int image_seq;
 972
 973                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 974
 975                 if (ubi_io_is_bad(ubi, pnum)) {
 976                         ret = UBI_BAD_FASTMAP;
 977                         goto free_hdr;
 978                 }
 979
 980                 if (i == 0 && pnum != fm_anchor) {
 981                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 982                                 pnum, fm_anchor);
 983                         ret = UBI_BAD_FASTMAP;
 984                         goto free_hdr;
 985                 }
 986
 987                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 988                 if (ret && ret != UBI_IO_BITFLIPS) {
 989                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 990                                 i, pnum);
 991                         if (ret > 0)
 992                                 ret = UBI_BAD_FASTMAP;
 993                         goto free_hdr;
 994                 } else if (ret == UBI_IO_BITFLIPS)
 995                         fm->to_be_tortured[i] = 1;
 996
 997                 image_seq = be32_to_cpu(ech->image_seq);
 998                 if (!ubi->image_seq)
 999                         ubi->image_seq = image_seq;
1000
1001                 /*
1002                  * Older UBI implementations have image_seq set to zero, so
1003                  * we shouldn't fail if image_seq == 0.
1004                  */
1005                 if (image_seq && (image_seq != ubi->image_seq)) {
1006                         ubi_err(ubi, "wrong image seq:%d instead of %d",
1007                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
1008                         ret = UBI_BAD_FASTMAP;
1009                         goto free_hdr;
1010                 }
1011
1012                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
1013                 if (ret && ret != UBI_IO_BITFLIPS) {
1014                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1015                                 i, pnum);
1016                         goto free_hdr;
1017                 }
1018
1019                 if (i == 0) {
1020                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1021                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1022                                         be32_to_cpu(vh->vol_id),
1023                                         UBI_FM_SB_VOLUME_ID);
1024                                 ret = UBI_BAD_FASTMAP;
1025                                 goto free_hdr;
1026                         }
1027                 } else {
1028                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1029                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1030                                         be32_to_cpu(vh->vol_id),
1031                                         UBI_FM_DATA_VOLUME_ID);
1032                                 ret = UBI_BAD_FASTMAP;
1033                                 goto free_hdr;
1034                         }
1035                 }
1036
1037                 if (sqnum < be64_to_cpu(vh->sqnum))
1038                         sqnum = be64_to_cpu(vh->sqnum);
1039
1040                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1041                                   ubi->leb_start, ubi->leb_size);
1042                 if (ret && ret != UBI_IO_BITFLIPS) {
1043                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1044                                 "err: %i)", i, pnum, ret);
1045                         goto free_hdr;
1046                 }
1047         }
1048
1049         kfree(fmsb);
1050         fmsb = NULL;
1051
1052         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1053         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1054         fmsb2->data_crc = 0;
1055         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1056         if (crc != tmp_crc) {
1057                 ubi_err(ubi, "fastmap data CRC is invalid");
1058                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1059                         tmp_crc, crc);
1060                 ret = UBI_BAD_FASTMAP;
1061                 goto free_hdr;
1062         }
1063
1064         fmsb2->sqnum = sqnum;
1065
1066         fm->used_blocks = used_blocks;
1067
1068         ret = ubi_attach_fastmap(ubi, ai, fm);
1069         if (ret) {
1070                 if (ret > 0)
1071                         ret = UBI_BAD_FASTMAP;
1072                 goto free_hdr;
1073         }
1074
1075         for (i = 0; i < used_blocks; i++) {
1076                 struct ubi_wl_entry *e;
1077
1078                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1079                 if (!e) {
1080                         while (i--)
1081                                 kfree(fm->e[i]);
1082
1083                         ret = -ENOMEM;
1084                         goto free_hdr;
1085                 }
1086
1087                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1088                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1089                 fm->e[i] = e;
1090         }
1091
1092         ubi->fm = fm;
1093         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1094         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1095         ubi_msg(ubi, "attached by fastmap");
1096         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1097         ubi_msg(ubi, "fastmap WL pool size: %d",
1098                 ubi->fm_wl_pool.max_size);
1099         ubi->fm_disabled = 0;
1100         ubi->fast_attach = 1;
1101
1102         ubi_free_vid_hdr(ubi, vh);
1103         kfree(ech);
1104 out:
1105         up_write(&ubi->fm_protect);
1106         if (ret == UBI_BAD_FASTMAP)
1107                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1108         return ret;
1109
1110 free_hdr:
1111         ubi_free_vid_hdr(ubi, vh);
1112         kfree(ech);
1113 free_fm_sb:
1114         kfree(fmsb);
1115         kfree(fm);
1116         goto out;
1117 }
1118
1119 /**
1120  * ubi_write_fastmap - writes a fastmap.
1121  * @ubi: UBI device object
1122  * @new_fm: the to be written fastmap
1123  *
1124  * Returns 0 on success, < 0 indicates an internal error.
1125  */
1126 static int ubi_write_fastmap(struct ubi_device *ubi,
1127                              struct ubi_fastmap_layout *new_fm)
1128 {
1129         size_t fm_pos = 0;
1130         void *fm_raw;
1131         struct ubi_fm_sb *fmsb;
1132         struct ubi_fm_hdr *fmh;
1133         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1134         struct ubi_fm_ec *fec;
1135         struct ubi_fm_volhdr *fvh;
1136         struct ubi_fm_eba *feba;
1137         struct ubi_wl_entry *wl_e;
1138         struct ubi_volume *vol;
1139         struct ubi_vid_hdr *avhdr, *dvhdr;
1140         struct ubi_work *ubi_wrk;
1141         struct rb_node *tmp_rb;
1142         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1143         int scrub_peb_count, erase_peb_count;
1144         unsigned long *seen_pebs = NULL;
1145
1146         fm_raw = ubi->fm_buf;
1147         memset(ubi->fm_buf, 0, ubi->fm_size);
1148
1149         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1150         if (!avhdr) {
1151                 ret = -ENOMEM;
1152                 goto out;
1153         }
1154
1155         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1156         if (!dvhdr) {
1157                 ret = -ENOMEM;
1158                 goto out_kfree;
1159         }
1160
1161         seen_pebs = init_seen(ubi);
1162         if (IS_ERR(seen_pebs)) {
1163                 ret = PTR_ERR(seen_pebs);
1164                 goto out_kfree;
1165         }
1166
1167         spin_lock(&ubi->volumes_lock);
1168         spin_lock(&ubi->wl_lock);
1169
1170         fmsb = (struct ubi_fm_sb *)fm_raw;
1171         fm_pos += sizeof(*fmsb);
1172         ubi_assert(fm_pos <= ubi->fm_size);
1173
1174         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1175         fm_pos += sizeof(*fmh);
1176         ubi_assert(fm_pos <= ubi->fm_size);
1177
1178         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1179         fmsb->version = UBI_FM_FMT_VERSION;
1180         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1181         /* the max sqnum will be filled in while *reading* the fastmap */
1182         fmsb->sqnum = 0;
1183
1184         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1185         free_peb_count = 0;
1186         used_peb_count = 0;
1187         scrub_peb_count = 0;
1188         erase_peb_count = 0;
1189         vol_count = 0;
1190
1191         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1192         fm_pos += sizeof(*fmpl);
1193         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1194         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1195         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1196
1197         for (i = 0; i < ubi->fm_pool.size; i++) {
1198                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1199                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1200         }
1201
1202         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1203         fm_pos += sizeof(*fmpl_wl);
1204         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1205         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1206         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1207
1208         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1209                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1210                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1211         }
1212
1213         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1214                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1215
1216                 fec->pnum = cpu_to_be32(wl_e->pnum);
1217                 set_seen(ubi, wl_e->pnum, seen_pebs);
1218                 fec->ec = cpu_to_be32(wl_e->ec);
1219
1220                 free_peb_count++;
1221                 fm_pos += sizeof(*fec);
1222                 ubi_assert(fm_pos <= ubi->fm_size);
1223         }
1224         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1225
1226         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1227                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1228
1229                 fec->pnum = cpu_to_be32(wl_e->pnum);
1230                 set_seen(ubi, wl_e->pnum, seen_pebs);
1231                 fec->ec = cpu_to_be32(wl_e->ec);
1232
1233                 used_peb_count++;
1234                 fm_pos += sizeof(*fec);
1235                 ubi_assert(fm_pos <= ubi->fm_size);
1236         }
1237
1238         ubi_for_each_protected_peb(ubi, i, wl_e) {
1239                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1240
1241                 fec->pnum = cpu_to_be32(wl_e->pnum);
1242                 set_seen(ubi, wl_e->pnum, seen_pebs);
1243                 fec->ec = cpu_to_be32(wl_e->ec);
1244
1245                 used_peb_count++;
1246                 fm_pos += sizeof(*fec);
1247                 ubi_assert(fm_pos <= ubi->fm_size);
1248         }
1249         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1250
1251         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1252                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1253
1254                 fec->pnum = cpu_to_be32(wl_e->pnum);
1255                 set_seen(ubi, wl_e->pnum, seen_pebs);
1256                 fec->ec = cpu_to_be32(wl_e->ec);
1257
1258                 scrub_peb_count++;
1259                 fm_pos += sizeof(*fec);
1260                 ubi_assert(fm_pos <= ubi->fm_size);
1261         }
1262         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1263
1264
1265         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1266                 if (ubi_is_erase_work(ubi_wrk)) {
1267                         wl_e = ubi_wrk->e;
1268                         ubi_assert(wl_e);
1269
1270                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1271
1272                         fec->pnum = cpu_to_be32(wl_e->pnum);
1273                         set_seen(ubi, wl_e->pnum, seen_pebs);
1274                         fec->ec = cpu_to_be32(wl_e->ec);
1275
1276                         erase_peb_count++;
1277                         fm_pos += sizeof(*fec);
1278                         ubi_assert(fm_pos <= ubi->fm_size);
1279                 }
1280         }
1281         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1282
1283         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1284                 vol = ubi->volumes[i];
1285
1286                 if (!vol)
1287                         continue;
1288
1289                 vol_count++;
1290
1291                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1292                 fm_pos += sizeof(*fvh);
1293                 ubi_assert(fm_pos <= ubi->fm_size);
1294
1295                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1296                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1297                 fvh->vol_type = vol->vol_type;
1298                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1299                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1300                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1301
1302                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1303                         vol->vol_type == UBI_STATIC_VOLUME);
1304
1305                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1306                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1307                 ubi_assert(fm_pos <= ubi->fm_size);
1308
1309                 for (j = 0; j < vol->reserved_pebs; j++)
1310                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1311
1312                 feba->reserved_pebs = cpu_to_be32(j);
1313                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1314         }
1315         fmh->vol_count = cpu_to_be32(vol_count);
1316         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1317
1318         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1319         avhdr->lnum = 0;
1320
1321         spin_unlock(&ubi->wl_lock);
1322         spin_unlock(&ubi->volumes_lock);
1323
1324         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1325         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1326         if (ret) {
1327                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1328                 goto out_kfree;
1329         }
1330
1331         for (i = 0; i < new_fm->used_blocks; i++) {
1332                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1333                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1334                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1335         }
1336
1337         fmsb->data_crc = 0;
1338         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1339                                            ubi->fm_size));
1340
1341         for (i = 1; i < new_fm->used_blocks; i++) {
1342                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1343                 dvhdr->lnum = cpu_to_be32(i);
1344                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1345                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1346                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1347                 if (ret) {
1348                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1349                                 new_fm->e[i]->pnum);
1350                         goto out_kfree;
1351                 }
1352         }
1353
1354         for (i = 0; i < new_fm->used_blocks; i++) {
1355                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1356                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1357                 if (ret) {
1358                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1359                                 new_fm->e[i]->pnum);
1360                         goto out_kfree;
1361                 }
1362         }
1363
1364         ubi_assert(new_fm);
1365         ubi->fm = new_fm;
1366
1367         ret = self_check_seen(ubi, seen_pebs);
1368         dbg_bld("fastmap written!");
1369
1370 out_kfree:
1371         ubi_free_vid_hdr(ubi, avhdr);
1372         ubi_free_vid_hdr(ubi, dvhdr);
1373         free_seen(seen_pebs);
1374 out:
1375         return ret;
1376 }
1377
1378 /**
1379  * erase_block - Manually erase a PEB.
1380  * @ubi: UBI device object
1381  * @pnum: PEB to be erased
1382  *
1383  * Returns the new EC value on success, < 0 indicates an internal error.
1384  */
1385 static int erase_block(struct ubi_device *ubi, int pnum)
1386 {
1387         int ret;
1388         struct ubi_ec_hdr *ec_hdr;
1389         long long ec;
1390
1391         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1392         if (!ec_hdr)
1393                 return -ENOMEM;
1394
1395         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1396         if (ret < 0)
1397                 goto out;
1398         else if (ret && ret != UBI_IO_BITFLIPS) {
1399                 ret = -EINVAL;
1400                 goto out;
1401         }
1402
1403         ret = ubi_io_sync_erase(ubi, pnum, 0);
1404         if (ret < 0)
1405                 goto out;
1406
1407         ec = be64_to_cpu(ec_hdr->ec);
1408         ec += ret;
1409         if (ec > UBI_MAX_ERASECOUNTER) {
1410                 ret = -EINVAL;
1411                 goto out;
1412         }
1413
1414         ec_hdr->ec = cpu_to_be64(ec);
1415         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1416         if (ret < 0)
1417                 goto out;
1418
1419         ret = ec;
1420 out:
1421         kfree(ec_hdr);
1422         return ret;
1423 }
1424
1425 /**
1426  * invalidate_fastmap - destroys a fastmap.
1427  * @ubi: UBI device object
1428  *
1429  * This function ensures that upon next UBI attach a full scan
1430  * is issued. We need this if UBI is about to write a new fastmap
1431  * but is unable to do so. In this case we have two options:
1432  * a) Make sure that the current fastmap will not be usued upon
1433  * attach time and contine or b) fall back to RO mode to have the
1434  * current fastmap in a valid state.
1435  * Returns 0 on success, < 0 indicates an internal error.
1436  */
1437 static int invalidate_fastmap(struct ubi_device *ubi)
1438 {
1439         int ret;
1440         struct ubi_fastmap_layout *fm;
1441         struct ubi_wl_entry *e;
1442         struct ubi_vid_hdr *vh = NULL;
1443
1444         if (!ubi->fm)
1445                 return 0;
1446
1447         ubi->fm = NULL;
1448
1449         ret = -ENOMEM;
1450         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1451         if (!fm)
1452                 goto out;
1453
1454         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1455         if (!vh)
1456                 goto out_free_fm;
1457
1458         ret = -ENOSPC;
1459         e = ubi_wl_get_fm_peb(ubi, 1);
1460         if (!e)
1461                 goto out_free_fm;
1462
1463         /*
1464          * Create fake fastmap such that UBI will fall back
1465          * to scanning mode.
1466          */
1467         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1468         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1469         if (ret < 0) {
1470                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1471                 goto out_free_fm;
1472         }
1473
1474         fm->used_blocks = 1;
1475         fm->e[0] = e;
1476
1477         ubi->fm = fm;
1478
1479 out:
1480         ubi_free_vid_hdr(ubi, vh);
1481         return ret;
1482
1483 out_free_fm:
1484         kfree(fm);
1485         goto out;
1486 }
1487
1488 /**
1489  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1490  * WL sub-system.
1491  * @ubi: UBI device object
1492  * @fm: fastmap layout object
1493  */
1494 static void return_fm_pebs(struct ubi_device *ubi,
1495                            struct ubi_fastmap_layout *fm)
1496 {
1497         int i;
1498
1499         if (!fm)
1500                 return;
1501
1502         for (i = 0; i < fm->used_blocks; i++) {
1503                 if (fm->e[i]) {
1504                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1505                                           fm->to_be_tortured[i]);
1506                         fm->e[i] = NULL;
1507                 }
1508         }
1509 }
1510
1511 /**
1512  * ubi_update_fastmap - will be called by UBI if a volume changes or
1513  * a fastmap pool becomes full.
1514  * @ubi: UBI device object
1515  *
1516  * Returns 0 on success, < 0 indicates an internal error.
1517  */
1518 int ubi_update_fastmap(struct ubi_device *ubi)
1519 {
1520         int ret, i, j;
1521         struct ubi_fastmap_layout *new_fm, *old_fm;
1522         struct ubi_wl_entry *tmp_e;
1523
1524         down_write(&ubi->fm_protect);
1525
1526         ubi_refill_pools(ubi);
1527
1528         if (ubi->ro_mode || ubi->fm_disabled) {
1529                 up_write(&ubi->fm_protect);
1530                 return 0;
1531         }
1532
1533         ret = ubi_ensure_anchor_pebs(ubi);
1534         if (ret) {
1535                 up_write(&ubi->fm_protect);
1536                 return ret;
1537         }
1538
1539         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1540         if (!new_fm) {
1541                 up_write(&ubi->fm_protect);
1542                 return -ENOMEM;
1543         }
1544
1545         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1546         old_fm = ubi->fm;
1547         ubi->fm = NULL;
1548
1549         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1550                 ubi_err(ubi, "fastmap too large");
1551                 ret = -ENOSPC;
1552                 goto err;
1553         }
1554
1555         for (i = 1; i < new_fm->used_blocks; i++) {
1556                 spin_lock(&ubi->wl_lock);
1557                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1558                 spin_unlock(&ubi->wl_lock);
1559
1560                 if (!tmp_e) {
1561                         if (old_fm && old_fm->e[i]) {
1562                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1563                                 if (ret < 0) {
1564                                         ubi_err(ubi, "could not erase old fastmap PEB");
1565
1566                                         for (j = 1; j < i; j++) {
1567                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1568                                                                   j, 0);
1569                                                 new_fm->e[j] = NULL;
1570                                         }
1571                                         goto err;
1572                                 }
1573                                 new_fm->e[i] = old_fm->e[i];
1574                                 old_fm->e[i] = NULL;
1575                         } else {
1576                                 ubi_err(ubi, "could not get any free erase block");
1577
1578                                 for (j = 1; j < i; j++) {
1579                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1580                                         new_fm->e[j] = NULL;
1581                                 }
1582
1583                                 ret = -ENOSPC;
1584                                 goto err;
1585                         }
1586                 } else {
1587                         new_fm->e[i] = tmp_e;
1588
1589                         if (old_fm && old_fm->e[i]) {
1590                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1591                                                   old_fm->to_be_tortured[i]);
1592                                 old_fm->e[i] = NULL;
1593                         }
1594                 }
1595         }
1596
1597         /* Old fastmap is larger than the new one */
1598         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1599                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1600                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1601                                           old_fm->to_be_tortured[i]);
1602                         old_fm->e[i] = NULL;
1603                 }
1604         }
1605
1606         spin_lock(&ubi->wl_lock);
1607         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1608         spin_unlock(&ubi->wl_lock);
1609
1610         if (old_fm) {
1611                 /* no fresh anchor PEB was found, reuse the old one */
1612                 if (!tmp_e) {
1613                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1614                         if (ret < 0) {
1615                                 ubi_err(ubi, "could not erase old anchor PEB");
1616
1617                                 for (i = 1; i < new_fm->used_blocks; i++) {
1618                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1619                                                           i, 0);
1620                                         new_fm->e[i] = NULL;
1621                                 }
1622                                 goto err;
1623                         }
1624                         new_fm->e[0] = old_fm->e[0];
1625                         new_fm->e[0]->ec = ret;
1626                         old_fm->e[0] = NULL;
1627                 } else {
1628                         /* we've got a new anchor PEB, return the old one */
1629                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1630                                           old_fm->to_be_tortured[0]);
1631                         new_fm->e[0] = tmp_e;
1632                         old_fm->e[0] = NULL;
1633                 }
1634         } else {
1635                 if (!tmp_e) {
1636                         ubi_err(ubi, "could not find any anchor PEB");
1637
1638                         for (i = 1; i < new_fm->used_blocks; i++) {
1639                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1640                                 new_fm->e[i] = NULL;
1641                         }
1642
1643                         ret = -ENOSPC;
1644                         goto err;
1645                 }
1646                 new_fm->e[0] = tmp_e;
1647         }
1648
1649         down_write(&ubi->work_sem);
1650         down_write(&ubi->fm_eba_sem);
1651         ret = ubi_write_fastmap(ubi, new_fm);
1652         up_write(&ubi->fm_eba_sem);
1653         up_write(&ubi->work_sem);
1654
1655         if (ret)
1656                 goto err;
1657
1658 out_unlock:
1659         up_write(&ubi->fm_protect);
1660         kfree(old_fm);
1661         return ret;
1662
1663 err:
1664         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1665
1666         ret = invalidate_fastmap(ubi);
1667         if (ret < 0) {
1668                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1669                 ubi_ro_mode(ubi);
1670         } else {
1671                 return_fm_pebs(ubi, old_fm);
1672                 return_fm_pebs(ubi, new_fm);
1673                 ret = 0;
1674         }
1675
1676         kfree(new_fm);
1677         goto out_unlock;
1678 }