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