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         int vol_id = be32_to_cpu(new_vh->vol_id);
 374         struct ubi_ainf_volume *av;
 375
 376         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 377                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 378
 379                 return 0;
 380         }
 381
 382         /* Find the volume this SEB belongs to */
 383         av = ubi_find_av(ai, vol_id);
 384         if (!av) {
 385                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 386                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 387                 return UBI_BAD_FASTMAP;
 388         }
 389
 390         ubi_assert(vol_id == av->vol_id);
 391
 392         return update_vol(ubi, ai, av, new_vh, new_aeb);
 393 }
 394
 395 /**
 396  * unmap_peb - unmap a PEB.
 397  * If fastmap detects a free PEB in the pool it has to check whether
 398  * this PEB has been unmapped after writing the fastmap.
 399  *
 400  * @ai: UBI attach info object
 401  * @pnum: The PEB to be unmapped
 402  */
 403 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 404 {
 405         struct ubi_ainf_volume *av;
 406         struct rb_node *node, *node2;
 407         struct ubi_ainf_peb *aeb;
 408
 409         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 410                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 411
 412                 for (node2 = rb_first(&av->root); node2;
 413                      node2 = rb_next(node2)) {
 414                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 415                         if (aeb->pnum == pnum) {
 416                                 rb_erase(&aeb->u.rb, &av->root);
 417                                 av->leb_count--;
 418                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 419                                 return;
 420                         }
 421                 }
 422         }
 423 }
 424
 425 /**
 426  * scan_pool - scans a pool for changed (no longer empty PEBs).
 427  * @ubi: UBI device object
 428  * @ai: attach info object
 429  * @pebs: an array of all PEB numbers in the to be scanned pool
 430  * @pool_size: size of the pool (number of entries in @pebs)
 431  * @max_sqnum: pointer to the maximal sequence number
 432  * @free: list of PEBs which are most likely free (and go into @ai->free)
 433  *
 434  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 435  * < 0 indicates an internal error.
 436  */
 437 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 438                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 439                      struct list_head *free)
 440 {
 441         struct ubi_vid_hdr *vh;
 442         struct ubi_ec_hdr *ech;
 443         struct ubi_ainf_peb *new_aeb;
 444         int i, pnum, err, ret = 0;
 445
 446         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 447         if (!ech)
 448                 return -ENOMEM;
 449
 450         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 451         if (!vh) {
 452                 kfree(ech);
 453                 return -ENOMEM;
 454         }
 455
 456         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 457
 458         /*
 459          * Now scan all PEBs in the pool to find changes which have been made
 460          * after the creation of the fastmap
 461          */
 462         for (i = 0; i < pool_size; i++) {
 463                 int scrub = 0;
 464                 int image_seq;
 465
 466                 pnum = be32_to_cpu(pebs[i]);
 467
 468                 if (ubi_io_is_bad(ubi, pnum)) {
 469                         ubi_err(ubi, "bad PEB in fastmap pool!");
 470                         ret = UBI_BAD_FASTMAP;
 471                         goto out;
 472                 }
 473
 474                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 475                 if (err && err != UBI_IO_BITFLIPS) {
 476                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 477                                 pnum, err);
 478                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 479                         goto out;
 480                 } else if (err == UBI_IO_BITFLIPS)
 481                         scrub = 1;
 482
 483                 /*
 484                  * Older UBI implementations have image_seq set to zero, so
 485                  * we shouldn't fail if image_seq == 0.
 486                  */
 487                 image_seq = be32_to_cpu(ech->image_seq);
 488
 489                 if (image_seq && (image_seq != ubi->image_seq)) {
 490                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 491                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 492                         ret = UBI_BAD_FASTMAP;
 493                         goto out;
 494                 }
 495
 496                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 497                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 498                         unsigned long long ec = be64_to_cpu(ech->ec);
 499                         unmap_peb(ai, pnum);
 500                         dbg_bld("Adding PEB to free: %i", pnum);
 501                         if (err == UBI_IO_FF_BITFLIPS)
 502                                 add_aeb(ai, free, pnum, ec, 1);
 503                         else
 504                                 add_aeb(ai, free, pnum, ec, 0);
 505                         continue;
 506                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 507                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 508
 509                         if (err == UBI_IO_BITFLIPS)
 510                                 scrub = 1;
 511
 512                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 513                                                    GFP_KERNEL);
 514                         if (!new_aeb) {
 515                                 ret = -ENOMEM;
 516                                 goto out;
 517                         }
 518
 519                         new_aeb->ec = be64_to_cpu(ech->ec);
 520                         new_aeb->pnum = pnum;
 521                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 522                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 523                         new_aeb->copy_flag = vh->copy_flag;
 524                         new_aeb->scrub = scrub;
 525
 526                         if (*max_sqnum < new_aeb->sqnum)
 527                                 *max_sqnum = new_aeb->sqnum;
 528
 529                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 530                         if (err) {
 531                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 532                                 goto out;
 533                         }
 534                 } else {
 535                         /* We are paranoid and fall back to scanning mode */
 536                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 537                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 538                         goto out;
 539                 }
 540
 541         }
 542
 543 out:
 544         ubi_free_vid_hdr(ubi, vh);
 545         kfree(ech);
 546         return ret;
 547 }
 548
 549 /**
 550  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 551  * @ai: The UBI attach info object
 552  */
 553 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 554 {
 555         struct ubi_ainf_peb *aeb;
 556         struct ubi_ainf_volume *av;
 557         struct rb_node *rb1, *rb2;
 558         int n = 0;
 559
 560         list_for_each_entry(aeb, &ai->erase, u.list)
 561                 n++;
 562
 563         list_for_each_entry(aeb, &ai->free, u.list)
 564                 n++;
 565
 566         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 567                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 568                         n++;
 569
 570         return n;
 571 }
 572
 573 /**
 574  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 575  * @ubi: UBI device object
 576  * @ai: UBI attach info object
 577  * @fm: the fastmap to be attached
 578  *
 579  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 580  * < 0 indicates an internal error.
 581  */
 582 static int ubi_attach_fastmap(struct ubi_device *ubi,
 583                               struct ubi_attach_info *ai,
 584                               struct ubi_fastmap_layout *fm)
 585 {
 586         struct list_head used, free;
 587         struct ubi_ainf_volume *av;
 588         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 589         struct ubi_fm_sb *fmsb;
 590         struct ubi_fm_hdr *fmhdr;
 591         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 592         struct ubi_fm_ec *fmec;
 593         struct ubi_fm_volhdr *fmvhdr;
 594         struct ubi_fm_eba *fm_eba;
 595         int ret, i, j, pool_size, wl_pool_size;
 596         size_t fm_pos = 0, fm_size = ubi->fm_size;
 597         unsigned long long max_sqnum = 0;
 598         void *fm_raw = ubi->fm_buf;
 599
 600         INIT_LIST_HEAD(&used);
 601         INIT_LIST_HEAD(&free);
 602         ai->min_ec = UBI_MAX_ERASECOUNTER;
 603
 604         fmsb = (struct ubi_fm_sb *)(fm_raw);
 605         ai->max_sqnum = fmsb->sqnum;
 606         fm_pos += sizeof(struct ubi_fm_sb);
 607         if (fm_pos >= fm_size)
 608                 goto fail_bad;
 609
 610         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 611         fm_pos += sizeof(*fmhdr);
 612         if (fm_pos >= fm_size)
 613                 goto fail_bad;
 614
 615         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 616                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 617                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 618                 goto fail_bad;
 619         }
 620
 621         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 622         fm_pos += sizeof(*fmpl);
 623         if (fm_pos >= fm_size)
 624                 goto fail_bad;
 625         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 626                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 627                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 628                 goto fail_bad;
 629         }
 630
 631         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 632         fm_pos += sizeof(*fmpl_wl);
 633         if (fm_pos >= fm_size)
 634                 goto fail_bad;
 635         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 636                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 637                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 638                 goto fail_bad;
 639         }
 640
 641         pool_size = be16_to_cpu(fmpl->size);
 642         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 643         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 644         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 645
 646         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 647                 ubi_err(ubi, "bad pool size: %i", pool_size);
 648                 goto fail_bad;
 649         }
 650
 651         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 652                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 653                 goto fail_bad;
 654         }
 655
 656
 657         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 658             fm->max_pool_size < 0) {
 659                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 660                 goto fail_bad;
 661         }
 662
 663         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 664             fm->max_wl_pool_size < 0) {
 665                 ubi_err(ubi, "bad maximal WL pool size: %i",
 666                         fm->max_wl_pool_size);
 667                 goto fail_bad;
 668         }
 669
 670         /* read EC values from free list */
 671         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 672                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 673                 fm_pos += sizeof(*fmec);
 674                 if (fm_pos >= fm_size)
 675                         goto fail_bad;
 676
 677                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 678                         be32_to_cpu(fmec->ec), 0);
 679         }
 680
 681         /* read EC values from used list */
 682         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 683                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 684                 fm_pos += sizeof(*fmec);
 685                 if (fm_pos >= fm_size)
 686                         goto fail_bad;
 687
 688                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 689                         be32_to_cpu(fmec->ec), 0);
 690         }
 691
 692         /* read EC values from scrub list */
 693         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 694                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 695                 fm_pos += sizeof(*fmec);
 696                 if (fm_pos >= fm_size)
 697                         goto fail_bad;
 698
 699                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 700                         be32_to_cpu(fmec->ec), 1);
 701         }
 702
 703         /* read EC values from erase list */
 704         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 705                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 706                 fm_pos += sizeof(*fmec);
 707                 if (fm_pos >= fm_size)
 708                         goto fail_bad;
 709
 710                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 711                         be32_to_cpu(fmec->ec), 1);
 712         }
 713
 714         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 715         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 716
 717         /* Iterate over all volumes and read their EBA table */
 718         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 719                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 720                 fm_pos += sizeof(*fmvhdr);
 721                 if (fm_pos >= fm_size)
 722                         goto fail_bad;
 723
 724                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 725                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 726                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 727                         goto fail_bad;
 728                 }
 729
 730                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 731                              be32_to_cpu(fmvhdr->used_ebs),
 732                              be32_to_cpu(fmvhdr->data_pad),
 733                              fmvhdr->vol_type,
 734                              be32_to_cpu(fmvhdr->last_eb_bytes));
 735
 736                 if (!av)
 737                         goto fail_bad;
 738                 if (PTR_ERR(av) == -EINVAL) {
 739                         ubi_err(ubi, "volume (ID %i) already exists",
 740                                 fmvhdr->vol_id);
 741                         goto fail_bad;
 742                 }
 743
 744                 ai->vols_found++;
 745                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 746                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 747
 748                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 749                 fm_pos += sizeof(*fm_eba);
 750                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 751                 if (fm_pos >= fm_size)
 752                         goto fail_bad;
 753
 754                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 755                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 756                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 757                         goto fail_bad;
 758                 }
 759
 760                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 761                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 762
 763                         if (pnum < 0)
 764                                 continue;
 765
 766                         aeb = NULL;
 767                         list_for_each_entry(tmp_aeb, &used, u.list) {
 768                                 if (tmp_aeb->pnum == pnum) {
 769                                         aeb = tmp_aeb;
 770                                         break;
 771                                 }
 772                         }
 773
 774                         if (!aeb) {
 775                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 776                                 goto fail_bad;
 777                         }
 778
 779                         aeb->lnum = j;
 780
 781                         if (av->highest_lnum <= aeb->lnum)
 782                                 av->highest_lnum = aeb->lnum;
 783
 784                         assign_aeb_to_av(ai, aeb, av);
 785
 786                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 787                                 aeb->pnum, aeb->lnum, av->vol_id);
 788                 }
 789         }
 790
 791         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 792         if (ret)
 793                 goto fail;
 794
 795         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 796         if (ret)
 797                 goto fail;
 798
 799         if (max_sqnum > ai->max_sqnum)
 800                 ai->max_sqnum = max_sqnum;
 801
 802         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 803                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 804
 805         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 806                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 807
 808         ubi_assert(list_empty(&free));
 809
 810         /*
 811          * If fastmap is leaking PEBs (must not happen), raise a
 812          * fat warning and fall back to scanning mode.
 813          * We do this here because in ubi_wl_init() it's too late
 814          * and we cannot fall back to scanning.
 815          */
 816         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 817                     ai->bad_peb_count - fm->used_blocks))
 818                 goto fail_bad;
 819
 820         return 0;
 821
 822 fail_bad:
 823         ret = UBI_BAD_FASTMAP;
 824 fail:
 825         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 826                 list_del(&tmp_aeb->u.list);
 827                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 828         }
 829         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 830                 list_del(&tmp_aeb->u.list);
 831                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 832         }
 833
 834         return ret;
 835 }
 836
 837 /**
 838  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 839  * @ai: UBI attach info to be filled
 840  */
 841 static int find_fm_anchor(struct ubi_attach_info *ai)
 842 {
 843         int ret = -1;
 844         struct ubi_ainf_peb *aeb;
 845         unsigned long long max_sqnum = 0;
 846
 847         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 848                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 849                         max_sqnum = aeb->sqnum;
 850                         ret = aeb->pnum;
 851                 }
 852         }
 853
 854         return ret;
 855 }
 856
 857 /**
 858  * ubi_scan_fastmap - scan the fastmap.
 859  * @ubi: UBI device object
 860  * @ai: UBI attach info to be filled
 861  * @scan_ai: UBI attach info from the first 64 PEBs,
 862  *           used to find the most recent Fastmap data structure
 863  *
 864  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 865  * UBI_BAD_FASTMAP if one was found but is not usable.
 866  * < 0 indicates an internal error.
 867  */
 868 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 869                      struct ubi_attach_info *scan_ai)
 870 {
 871         struct ubi_fm_sb *fmsb, *fmsb2;
 872         struct ubi_vid_hdr *vh;
 873         struct ubi_ec_hdr *ech;
 874         struct ubi_fastmap_layout *fm;
 875         struct ubi_ainf_peb *tmp_aeb, *aeb;
 876         int i, used_blocks, pnum, fm_anchor, ret = 0;
 877         size_t fm_size;
 878         __be32 crc, tmp_crc;
 879         unsigned long long sqnum = 0;
 880
 881         fm_anchor = find_fm_anchor(scan_ai);
 882         if (fm_anchor < 0)
 883                 return UBI_NO_FASTMAP;
 884
 885         /* Move all (possible) fastmap blocks into our new attach structure. */
 886         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 887                 list_move_tail(&aeb->u.list, &ai->fastmap);
 888
 889         down_write(&ubi->fm_protect);
 890         memset(ubi->fm_buf, 0, ubi->fm_size);
 891
 892         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 893         if (!fmsb) {
 894                 ret = -ENOMEM;
 895                 goto out;
 896         }
 897
 898         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 899         if (!fm) {
 900                 ret = -ENOMEM;
 901                 kfree(fmsb);
 902                 goto out;
 903         }
 904
 905         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 906         if (ret && ret != UBI_IO_BITFLIPS)
 907                 goto free_fm_sb;
 908         else if (ret == UBI_IO_BITFLIPS)
 909                 fm->to_be_tortured[0] = 1;
 910
 911         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 912                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 913                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 914                 ret = UBI_BAD_FASTMAP;
 915                 goto free_fm_sb;
 916         }
 917
 918         if (fmsb->version != UBI_FM_FMT_VERSION) {
 919                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 920                         fmsb->version, UBI_FM_FMT_VERSION);
 921                 ret = UBI_BAD_FASTMAP;
 922                 goto free_fm_sb;
 923         }
 924
 925         used_blocks = be32_to_cpu(fmsb->used_blocks);
 926         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 927                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 928                         used_blocks);
 929                 ret = UBI_BAD_FASTMAP;
 930                 goto free_fm_sb;
 931         }
 932
 933         fm_size = ubi->leb_size * used_blocks;
 934         if (fm_size != ubi->fm_size) {
 935                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 936                         fm_size, ubi->fm_size);
 937                 ret = UBI_BAD_FASTMAP;
 938                 goto free_fm_sb;
 939         }
 940
 941         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 942         if (!ech) {
 943                 ret = -ENOMEM;
 944                 goto free_fm_sb;
 945         }
 946
 947         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 948         if (!vh) {
 949                 ret = -ENOMEM;
 950                 goto free_hdr;
 951         }
 952
 953         for (i = 0; i < used_blocks; i++) {
 954                 int image_seq;
 955
 956                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 957
 958                 if (ubi_io_is_bad(ubi, pnum)) {
 959                         ret = UBI_BAD_FASTMAP;
 960                         goto free_hdr;
 961                 }
 962
 963                 if (i == 0 && pnum != fm_anchor) {
 964                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 965                                 pnum, fm_anchor);
 966                         ret = UBI_BAD_FASTMAP;
 967                         goto free_hdr;
 968                 }
 969
 970                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 971                 if (ret && ret != UBI_IO_BITFLIPS) {
 972                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 973                                 i, pnum);
 974                         if (ret > 0)
 975                                 ret = UBI_BAD_FASTMAP;
 976                         goto free_hdr;
 977                 } else if (ret == UBI_IO_BITFLIPS)
 978                         fm->to_be_tortured[i] = 1;
 979
 980                 image_seq = be32_to_cpu(ech->image_seq);
 981                 if (!ubi->image_seq)
 982                         ubi->image_seq = image_seq;
 983
 984                 /*
 985                  * Older UBI implementations have image_seq set to zero, so
 986                  * we shouldn't fail if image_seq == 0.
 987                  */
 988                 if (image_seq && (image_seq != ubi->image_seq)) {
 989                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 990                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 991                         ret = UBI_BAD_FASTMAP;
 992                         goto free_hdr;
 993                 }
 994
 995                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 996                 if (ret && ret != UBI_IO_BITFLIPS) {
 997                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 998                                 i, pnum);
 999                         goto free_hdr;
1000                 }
1001
1002                 if (i == 0) {
1003                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1004                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1005                                         be32_to_cpu(vh->vol_id),
1006                                         UBI_FM_SB_VOLUME_ID);
1007                                 ret = UBI_BAD_FASTMAP;
1008                                 goto free_hdr;
1009                         }
1010                 } else {
1011                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1012                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1013                                         be32_to_cpu(vh->vol_id),
1014                                         UBI_FM_DATA_VOLUME_ID);
1015                                 ret = UBI_BAD_FASTMAP;
1016                                 goto free_hdr;
1017                         }
1018                 }
1019
1020                 if (sqnum < be64_to_cpu(vh->sqnum))
1021                         sqnum = be64_to_cpu(vh->sqnum);
1022
1023                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1024                                   ubi->leb_start, ubi->leb_size);
1025                 if (ret && ret != UBI_IO_BITFLIPS) {
1026                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1027                                 "err: %i)", i, pnum, ret);
1028                         goto free_hdr;
1029                 }
1030         }
1031
1032         kfree(fmsb);
1033         fmsb = NULL;
1034
1035         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1036         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1037         fmsb2->data_crc = 0;
1038         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1039         if (crc != tmp_crc) {
1040                 ubi_err(ubi, "fastmap data CRC is invalid");
1041                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1042                         tmp_crc, crc);
1043                 ret = UBI_BAD_FASTMAP;
1044                 goto free_hdr;
1045         }
1046
1047         fmsb2->sqnum = sqnum;
1048
1049         fm->used_blocks = used_blocks;
1050
1051         ret = ubi_attach_fastmap(ubi, ai, fm);
1052         if (ret) {
1053                 if (ret > 0)
1054                         ret = UBI_BAD_FASTMAP;
1055                 goto free_hdr;
1056         }
1057
1058         for (i = 0; i < used_blocks; i++) {
1059                 struct ubi_wl_entry *e;
1060
1061                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1062                 if (!e) {
1063                         while (i--)
1064                                 kfree(fm->e[i]);
1065
1066                         ret = -ENOMEM;
1067                         goto free_hdr;
1068                 }
1069
1070                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1071                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1072                 fm->e[i] = e;
1073         }
1074
1075         ubi->fm = fm;
1076         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1077         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1078         ubi_msg(ubi, "attached by fastmap");
1079         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1080         ubi_msg(ubi, "fastmap WL pool size: %d",
1081                 ubi->fm_wl_pool.max_size);
1082         ubi->fm_disabled = 0;
1083         ubi->fast_attach = 1;
1084
1085         ubi_free_vid_hdr(ubi, vh);
1086         kfree(ech);
1087 out:
1088         up_write(&ubi->fm_protect);
1089         if (ret == UBI_BAD_FASTMAP)
1090                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1091         return ret;
1092
1093 free_hdr:
1094         ubi_free_vid_hdr(ubi, vh);
1095         kfree(ech);
1096 free_fm_sb:
1097         kfree(fmsb);
1098         kfree(fm);
1099         goto out;
1100 }
1101
1102 /**
1103  * ubi_write_fastmap - writes a fastmap.
1104  * @ubi: UBI device object
1105  * @new_fm: the to be written fastmap
1106  *
1107  * Returns 0 on success, < 0 indicates an internal error.
1108  */
1109 static int ubi_write_fastmap(struct ubi_device *ubi,
1110                              struct ubi_fastmap_layout *new_fm)
1111 {
1112         size_t fm_pos = 0;
1113         void *fm_raw;
1114         struct ubi_fm_sb *fmsb;
1115         struct ubi_fm_hdr *fmh;
1116         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1117         struct ubi_fm_ec *fec;
1118         struct ubi_fm_volhdr *fvh;
1119         struct ubi_fm_eba *feba;
1120         struct ubi_wl_entry *wl_e;
1121         struct ubi_volume *vol;
1122         struct ubi_vid_hdr *avhdr, *dvhdr;
1123         struct ubi_work *ubi_wrk;
1124         struct rb_node *tmp_rb;
1125         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1126         int scrub_peb_count, erase_peb_count;
1127         unsigned long *seen_pebs = NULL;
1128
1129         fm_raw = ubi->fm_buf;
1130         memset(ubi->fm_buf, 0, ubi->fm_size);
1131
1132         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1133         if (!avhdr) {
1134                 ret = -ENOMEM;
1135                 goto out;
1136         }
1137
1138         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1139         if (!dvhdr) {
1140                 ret = -ENOMEM;
1141                 goto out_kfree;
1142         }
1143
1144         seen_pebs = init_seen(ubi);
1145         if (IS_ERR(seen_pebs)) {
1146                 ret = PTR_ERR(seen_pebs);
1147                 goto out_kfree;
1148         }
1149
1150         spin_lock(&ubi->volumes_lock);
1151         spin_lock(&ubi->wl_lock);
1152
1153         fmsb = (struct ubi_fm_sb *)fm_raw;
1154         fm_pos += sizeof(*fmsb);
1155         ubi_assert(fm_pos <= ubi->fm_size);
1156
1157         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1158         fm_pos += sizeof(*fmh);
1159         ubi_assert(fm_pos <= ubi->fm_size);
1160
1161         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1162         fmsb->version = UBI_FM_FMT_VERSION;
1163         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1164         /* the max sqnum will be filled in while *reading* the fastmap */
1165         fmsb->sqnum = 0;
1166
1167         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1168         free_peb_count = 0;
1169         used_peb_count = 0;
1170         scrub_peb_count = 0;
1171         erase_peb_count = 0;
1172         vol_count = 0;
1173
1174         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1175         fm_pos += sizeof(*fmpl);
1176         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1177         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1178         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1179
1180         for (i = 0; i < ubi->fm_pool.size; i++) {
1181                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1182                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1183         }
1184
1185         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1186         fm_pos += sizeof(*fmpl_wl);
1187         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1188         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1189         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1190
1191         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1192                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1193                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1194         }
1195
1196         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1197                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1198
1199                 fec->pnum = cpu_to_be32(wl_e->pnum);
1200                 set_seen(ubi, wl_e->pnum, seen_pebs);
1201                 fec->ec = cpu_to_be32(wl_e->ec);
1202
1203                 free_peb_count++;
1204                 fm_pos += sizeof(*fec);
1205                 ubi_assert(fm_pos <= ubi->fm_size);
1206         }
1207         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1208
1209         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1210                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1211
1212                 fec->pnum = cpu_to_be32(wl_e->pnum);
1213                 set_seen(ubi, wl_e->pnum, seen_pebs);
1214                 fec->ec = cpu_to_be32(wl_e->ec);
1215
1216                 used_peb_count++;
1217                 fm_pos += sizeof(*fec);
1218                 ubi_assert(fm_pos <= ubi->fm_size);
1219         }
1220
1221         ubi_for_each_protected_peb(ubi, i, wl_e) {
1222                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1223
1224                 fec->pnum = cpu_to_be32(wl_e->pnum);
1225                 set_seen(ubi, wl_e->pnum, seen_pebs);
1226                 fec->ec = cpu_to_be32(wl_e->ec);
1227
1228                 used_peb_count++;
1229                 fm_pos += sizeof(*fec);
1230                 ubi_assert(fm_pos <= ubi->fm_size);
1231         }
1232         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1233
1234         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1235                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1236
1237                 fec->pnum = cpu_to_be32(wl_e->pnum);
1238                 set_seen(ubi, wl_e->pnum, seen_pebs);
1239                 fec->ec = cpu_to_be32(wl_e->ec);
1240
1241                 scrub_peb_count++;
1242                 fm_pos += sizeof(*fec);
1243                 ubi_assert(fm_pos <= ubi->fm_size);
1244         }
1245         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1246
1247
1248         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1249                 if (ubi_is_erase_work(ubi_wrk)) {
1250                         wl_e = ubi_wrk->e;
1251                         ubi_assert(wl_e);
1252
1253                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1254
1255                         fec->pnum = cpu_to_be32(wl_e->pnum);
1256                         set_seen(ubi, wl_e->pnum, seen_pebs);
1257                         fec->ec = cpu_to_be32(wl_e->ec);
1258
1259                         erase_peb_count++;
1260                         fm_pos += sizeof(*fec);
1261                         ubi_assert(fm_pos <= ubi->fm_size);
1262                 }
1263         }
1264         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1265
1266         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1267                 vol = ubi->volumes[i];
1268
1269                 if (!vol)
1270                         continue;
1271
1272                 vol_count++;
1273
1274                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1275                 fm_pos += sizeof(*fvh);
1276                 ubi_assert(fm_pos <= ubi->fm_size);
1277
1278                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1279                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1280                 fvh->vol_type = vol->vol_type;
1281                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1282                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1283                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1284
1285                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1286                         vol->vol_type == UBI_STATIC_VOLUME);
1287
1288                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1289                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1290                 ubi_assert(fm_pos <= ubi->fm_size);
1291
1292                 for (j = 0; j < vol->reserved_pebs; j++)
1293                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1294
1295                 feba->reserved_pebs = cpu_to_be32(j);
1296                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1297         }
1298         fmh->vol_count = cpu_to_be32(vol_count);
1299         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1300
1301         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1302         avhdr->lnum = 0;
1303
1304         spin_unlock(&ubi->wl_lock);
1305         spin_unlock(&ubi->volumes_lock);
1306
1307         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1308         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1309         if (ret) {
1310                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1311                 goto out_kfree;
1312         }
1313
1314         for (i = 0; i < new_fm->used_blocks; i++) {
1315                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1316                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1317                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1318         }
1319
1320         fmsb->data_crc = 0;
1321         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1322                                            ubi->fm_size));
1323
1324         for (i = 1; i < new_fm->used_blocks; i++) {
1325                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1326                 dvhdr->lnum = cpu_to_be32(i);
1327                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1328                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1329                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1330                 if (ret) {
1331                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1332                                 new_fm->e[i]->pnum);
1333                         goto out_kfree;
1334                 }
1335         }
1336
1337         for (i = 0; i < new_fm->used_blocks; i++) {
1338                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1339                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1340                 if (ret) {
1341                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1342                                 new_fm->e[i]->pnum);
1343                         goto out_kfree;
1344                 }
1345         }
1346
1347         ubi_assert(new_fm);
1348         ubi->fm = new_fm;
1349
1350         ret = self_check_seen(ubi, seen_pebs);
1351         dbg_bld("fastmap written!");
1352
1353 out_kfree:
1354         ubi_free_vid_hdr(ubi, avhdr);
1355         ubi_free_vid_hdr(ubi, dvhdr);
1356         free_seen(seen_pebs);
1357 out:
1358         return ret;
1359 }
1360
1361 /**
1362  * erase_block - Manually erase a PEB.
1363  * @ubi: UBI device object
1364  * @pnum: PEB to be erased
1365  *
1366  * Returns the new EC value on success, < 0 indicates an internal error.
1367  */
1368 static int erase_block(struct ubi_device *ubi, int pnum)
1369 {
1370         int ret;
1371         struct ubi_ec_hdr *ec_hdr;
1372         long long ec;
1373
1374         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1375         if (!ec_hdr)
1376                 return -ENOMEM;
1377
1378         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1379         if (ret < 0)
1380                 goto out;
1381         else if (ret && ret != UBI_IO_BITFLIPS) {
1382                 ret = -EINVAL;
1383                 goto out;
1384         }
1385
1386         ret = ubi_io_sync_erase(ubi, pnum, 0);
1387         if (ret < 0)
1388                 goto out;
1389
1390         ec = be64_to_cpu(ec_hdr->ec);
1391         ec += ret;
1392         if (ec > UBI_MAX_ERASECOUNTER) {
1393                 ret = -EINVAL;
1394                 goto out;
1395         }
1396
1397         ec_hdr->ec = cpu_to_be64(ec);
1398         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1399         if (ret < 0)
1400                 goto out;
1401
1402         ret = ec;
1403 out:
1404         kfree(ec_hdr);
1405         return ret;
1406 }
1407
1408 /**
1409  * invalidate_fastmap - destroys a fastmap.
1410  * @ubi: UBI device object
1411  *
1412  * This function ensures that upon next UBI attach a full scan
1413  * is issued. We need this if UBI is about to write a new fastmap
1414  * but is unable to do so. In this case we have two options:
1415  * a) Make sure that the current fastmap will not be usued upon
1416  * attach time and contine or b) fall back to RO mode to have the
1417  * current fastmap in a valid state.
1418  * Returns 0 on success, < 0 indicates an internal error.
1419  */
1420 static int invalidate_fastmap(struct ubi_device *ubi)
1421 {
1422         int ret;
1423         struct ubi_fastmap_layout *fm;
1424         struct ubi_wl_entry *e;
1425         struct ubi_vid_hdr *vh = NULL;
1426
1427         if (!ubi->fm)
1428                 return 0;
1429
1430         ubi->fm = NULL;
1431
1432         ret = -ENOMEM;
1433         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1434         if (!fm)
1435                 goto out;
1436
1437         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1438         if (!vh)
1439                 goto out_free_fm;
1440
1441         ret = -ENOSPC;
1442         e = ubi_wl_get_fm_peb(ubi, 1);
1443         if (!e)
1444                 goto out_free_fm;
1445
1446         /*
1447          * Create fake fastmap such that UBI will fall back
1448          * to scanning mode.
1449          */
1450         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1451         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1452         if (ret < 0) {
1453                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1454                 goto out_free_fm;
1455         }
1456
1457         fm->used_blocks = 1;
1458         fm->e[0] = e;
1459
1460         ubi->fm = fm;
1461
1462 out:
1463         ubi_free_vid_hdr(ubi, vh);
1464         return ret;
1465
1466 out_free_fm:
1467         kfree(fm);
1468         goto out;
1469 }
1470
1471 /**
1472  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1473  * WL sub-system.
1474  * @ubi: UBI device object
1475  * @fm: fastmap layout object
1476  */
1477 static void return_fm_pebs(struct ubi_device *ubi,
1478                            struct ubi_fastmap_layout *fm)
1479 {
1480         int i;
1481
1482         if (!fm)
1483                 return;
1484
1485         for (i = 0; i < fm->used_blocks; i++) {
1486                 if (fm->e[i]) {
1487                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1488                                           fm->to_be_tortured[i]);
1489                         fm->e[i] = NULL;
1490                 }
1491         }
1492 }
1493
1494 /**
1495  * ubi_update_fastmap - will be called by UBI if a volume changes or
1496  * a fastmap pool becomes full.
1497  * @ubi: UBI device object
1498  *
1499  * Returns 0 on success, < 0 indicates an internal error.
1500  */
1501 int ubi_update_fastmap(struct ubi_device *ubi)
1502 {
1503         int ret, i, j;
1504         struct ubi_fastmap_layout *new_fm, *old_fm;
1505         struct ubi_wl_entry *tmp_e;
1506
1507         down_write(&ubi->fm_protect);
1508
1509         ubi_refill_pools(ubi);
1510
1511         if (ubi->ro_mode || ubi->fm_disabled) {
1512                 up_write(&ubi->fm_protect);
1513                 return 0;
1514         }
1515
1516         ret = ubi_ensure_anchor_pebs(ubi);
1517         if (ret) {
1518                 up_write(&ubi->fm_protect);
1519                 return ret;
1520         }
1521
1522         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1523         if (!new_fm) {
1524                 up_write(&ubi->fm_protect);
1525                 return -ENOMEM;
1526         }
1527
1528         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1529         old_fm = ubi->fm;
1530         ubi->fm = NULL;
1531
1532         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1533                 ubi_err(ubi, "fastmap too large");
1534                 ret = -ENOSPC;
1535                 goto err;
1536         }
1537
1538         for (i = 1; i < new_fm->used_blocks; i++) {
1539                 spin_lock(&ubi->wl_lock);
1540                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1541                 spin_unlock(&ubi->wl_lock);
1542
1543                 if (!tmp_e) {
1544                         if (old_fm && old_fm->e[i]) {
1545                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1546                                 if (ret < 0) {
1547                                         ubi_err(ubi, "could not erase old fastmap PEB");
1548
1549                                         for (j = 1; j < i; j++) {
1550                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1551                                                                   j, 0);
1552                                                 new_fm->e[j] = NULL;
1553                                         }
1554                                         goto err;
1555                                 }
1556                                 new_fm->e[i] = old_fm->e[i];
1557                                 old_fm->e[i] = NULL;
1558                         } else {
1559                                 ubi_err(ubi, "could not get any free erase block");
1560
1561                                 for (j = 1; j < i; j++) {
1562                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1563                                         new_fm->e[j] = NULL;
1564                                 }
1565
1566                                 ret = -ENOSPC;
1567                                 goto err;
1568                         }
1569                 } else {
1570                         new_fm->e[i] = tmp_e;
1571
1572                         if (old_fm && old_fm->e[i]) {
1573                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1574                                                   old_fm->to_be_tortured[i]);
1575                                 old_fm->e[i] = NULL;
1576                         }
1577                 }
1578         }
1579
1580         /* Old fastmap is larger than the new one */
1581         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1582                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1583                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1584                                           old_fm->to_be_tortured[i]);
1585                         old_fm->e[i] = NULL;
1586                 }
1587         }
1588
1589         spin_lock(&ubi->wl_lock);
1590         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1591         spin_unlock(&ubi->wl_lock);
1592
1593         if (old_fm) {
1594                 /* no fresh anchor PEB was found, reuse the old one */
1595                 if (!tmp_e) {
1596                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1597                         if (ret < 0) {
1598                                 ubi_err(ubi, "could not erase old anchor PEB");
1599
1600                                 for (i = 1; i < new_fm->used_blocks; i++) {
1601                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1602                                                           i, 0);
1603                                         new_fm->e[i] = NULL;
1604                                 }
1605                                 goto err;
1606                         }
1607                         new_fm->e[0] = old_fm->e[0];
1608                         new_fm->e[0]->ec = ret;
1609                         old_fm->e[0] = NULL;
1610                 } else {
1611                         /* we've got a new anchor PEB, return the old one */
1612                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1613                                           old_fm->to_be_tortured[0]);
1614                         new_fm->e[0] = tmp_e;
1615                         old_fm->e[0] = NULL;
1616                 }
1617         } else {
1618                 if (!tmp_e) {
1619                         ubi_err(ubi, "could not find any anchor PEB");
1620
1621                         for (i = 1; i < new_fm->used_blocks; i++) {
1622                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1623                                 new_fm->e[i] = NULL;
1624                         }
1625
1626                         ret = -ENOSPC;
1627                         goto err;
1628                 }
1629                 new_fm->e[0] = tmp_e;
1630         }
1631
1632         down_write(&ubi->work_sem);
1633         down_write(&ubi->fm_eba_sem);
1634         ret = ubi_write_fastmap(ubi, new_fm);
1635         up_write(&ubi->fm_eba_sem);
1636         up_write(&ubi->work_sem);
1637
1638         if (ret)
1639                 goto err;
1640
1641 out_unlock:
1642         up_write(&ubi->fm_protect);
1643         kfree(old_fm);
1644         return ret;
1645
1646 err:
1647         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1648
1649         ret = invalidate_fastmap(ubi);
1650         if (ret < 0) {
1651                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1652                 ubi_ro_mode(ubi);
1653         } else {
1654                 return_fm_pebs(ubi, old_fm);
1655                 return_fm_pebs(ubi, new_fm);
1656                 ret = 0;
1657         }
1658
1659         kfree(new_fm);
1660         goto out_unlock;
1661 }