drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Copyright (c) 2014 sigma star gmbh
   4  * Author: Richard Weinberger <[email protected]>
   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                      int *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                         if (err == UBI_IO_FF_BITFLIPS)
 517                                 add_aeb(ai, free, pnum, ec, 1);
 518                         else
 519                                 add_aeb(ai, free, pnum, ec, 0);
 520                         continue;
 521                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 522                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 523
 524                         if (err == UBI_IO_BITFLIPS)
 525                                 scrub = 1;
 526
 527                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 528                                                    GFP_KERNEL);
 529                         if (!new_aeb) {
 530                                 ret = -ENOMEM;
 531                                 goto out;
 532                         }
 533
 534                         new_aeb->ec = be64_to_cpu(ech->ec);
 535                         new_aeb->pnum = pnum;
 536                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 537                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 538                         new_aeb->copy_flag = vh->copy_flag;
 539                         new_aeb->scrub = scrub;
 540
 541                         if (*max_sqnum < new_aeb->sqnum)
 542                                 *max_sqnum = new_aeb->sqnum;
 543
 544                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 545                         if (err) {
 546                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 547                                 goto out;
 548                         }
 549                 } else {
 550                         /* We are paranoid and fall back to scanning mode */
 551                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 552                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 553                         goto out;
 554                 }
 555
 556         }
 557
 558 out:
 559         ubi_free_vid_hdr(ubi, vh);
 560         kfree(ech);
 561         return ret;
 562 }
 563
 564 /**
 565  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 566  * @ai: The UBI attach info object
 567  */
 568 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 569 {
 570         struct ubi_ainf_peb *aeb;
 571         struct ubi_ainf_volume *av;
 572         struct rb_node *rb1, *rb2;
 573         int n = 0;
 574
 575         list_for_each_entry(aeb, &ai->erase, u.list)
 576                 n++;
 577
 578         list_for_each_entry(aeb, &ai->free, u.list)
 579                 n++;
 580
 581          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 582                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 583                         n++;
 584
 585         return n;
 586 }
 587
 588 /**
 589  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 590  * @ubi: UBI device object
 591  * @ai: UBI attach info object
 592  * @fm: the fastmap to be attached
 593  *
 594  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 595  * < 0 indicates an internal error.
 596  */
 597 static int ubi_attach_fastmap(struct ubi_device *ubi,
 598                               struct ubi_attach_info *ai,
 599                               struct ubi_fastmap_layout *fm)
 600 {
 601         struct list_head used, free;
 602         struct ubi_ainf_volume *av;
 603         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 604         struct ubi_fm_sb *fmsb;
 605         struct ubi_fm_hdr *fmhdr;
 606         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 607         struct ubi_fm_ec *fmec;
 608         struct ubi_fm_volhdr *fmvhdr;
 609         struct ubi_fm_eba *fm_eba;
 610         int ret, i, j, pool_size, wl_pool_size;
 611         size_t fm_pos = 0, fm_size = ubi->fm_size;
 612         unsigned long long max_sqnum = 0;
 613         void *fm_raw = ubi->fm_buf;
 614
 615         INIT_LIST_HEAD(&used);
 616         INIT_LIST_HEAD(&free);
 617         ai->min_ec = UBI_MAX_ERASECOUNTER;
 618
 619         fmsb = (struct ubi_fm_sb *)(fm_raw);
 620         ai->max_sqnum = fmsb->sqnum;
 621         fm_pos += sizeof(struct ubi_fm_sb);
 622         if (fm_pos >= fm_size)
 623                 goto fail_bad;
 624
 625         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 626         fm_pos += sizeof(*fmhdr);
 627         if (fm_pos >= fm_size)
 628                 goto fail_bad;
 629
 630         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 631                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 632                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 633                 goto fail_bad;
 634         }
 635
 636         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 637         fm_pos += sizeof(*fmpl);
 638         if (fm_pos >= fm_size)
 639                 goto fail_bad;
 640         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 641                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 642                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 643                 goto fail_bad;
 644         }
 645
 646         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 647         fm_pos += sizeof(*fmpl_wl);
 648         if (fm_pos >= fm_size)
 649                 goto fail_bad;
 650         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 651                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 652                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 653                 goto fail_bad;
 654         }
 655
 656         pool_size = be16_to_cpu(fmpl->size);
 657         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 658         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 659         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 660
 661         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 662                 ubi_err(ubi, "bad pool size: %i", pool_size);
 663                 goto fail_bad;
 664         }
 665
 666         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 667                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 668                 goto fail_bad;
 669         }
 670
 671
 672         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 673             fm->max_pool_size < 0) {
 674                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 675                 goto fail_bad;
 676         }
 677
 678         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 679             fm->max_wl_pool_size < 0) {
 680                 ubi_err(ubi, "bad maximal WL pool size: %i",
 681                         fm->max_wl_pool_size);
 682                 goto fail_bad;
 683         }
 684
 685         /* read EC values from free list */
 686         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 687                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 688                 fm_pos += sizeof(*fmec);
 689                 if (fm_pos >= fm_size)
 690                         goto fail_bad;
 691
 692                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 693                         be32_to_cpu(fmec->ec), 0);
 694         }
 695
 696         /* read EC values from used list */
 697         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 698                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 699                 fm_pos += sizeof(*fmec);
 700                 if (fm_pos >= fm_size)
 701                         goto fail_bad;
 702
 703                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 704                         be32_to_cpu(fmec->ec), 0);
 705         }
 706
 707         /* read EC values from scrub list */
 708         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 709                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 710                 fm_pos += sizeof(*fmec);
 711                 if (fm_pos >= fm_size)
 712                         goto fail_bad;
 713
 714                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 715                         be32_to_cpu(fmec->ec), 1);
 716         }
 717
 718         /* read EC values from erase list */
 719         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 720                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 721                 fm_pos += sizeof(*fmec);
 722                 if (fm_pos >= fm_size)
 723                         goto fail_bad;
 724
 725                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 726                         be32_to_cpu(fmec->ec), 1);
 727         }
 728
 729         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 730         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 731
 732         /* Iterate over all volumes and read their EBA table */
 733         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 734                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 735                 fm_pos += sizeof(*fmvhdr);
 736                 if (fm_pos >= fm_size)
 737                         goto fail_bad;
 738
 739                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 740                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 741                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 742                         goto fail_bad;
 743                 }
 744
 745                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 746                              be32_to_cpu(fmvhdr->used_ebs),
 747                              be32_to_cpu(fmvhdr->data_pad),
 748                              fmvhdr->vol_type,
 749                              be32_to_cpu(fmvhdr->last_eb_bytes));
 750
 751                 if (!av)
 752                         goto fail_bad;
 753                 if (PTR_ERR(av) == -EINVAL) {
 754                         ubi_err(ubi, "volume (ID %i) already exists",
 755                                 fmvhdr->vol_id);
 756                         goto fail_bad;
 757                 }
 758
 759                 ai->vols_found++;
 760                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 761                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 762
 763                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 764                 fm_pos += sizeof(*fm_eba);
 765                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 766                 if (fm_pos >= fm_size)
 767                         goto fail_bad;
 768
 769                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 770                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 771                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 772                         goto fail_bad;
 773                 }
 774
 775                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 776                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 777
 778                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 779                                 continue;
 780
 781                         aeb = NULL;
 782                         list_for_each_entry(tmp_aeb, &used, u.list) {
 783                                 if (tmp_aeb->pnum == pnum) {
 784                                         aeb = tmp_aeb;
 785                                         break;
 786                                 }
 787                         }
 788
 789                         if (!aeb) {
 790                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 791                                 goto fail_bad;
 792                         }
 793
 794                         aeb->lnum = j;
 795
 796                         if (av->highest_lnum <= aeb->lnum)
 797                                 av->highest_lnum = aeb->lnum;
 798
 799                         assign_aeb_to_av(ai, aeb, av);
 800
 801                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 802                                 aeb->pnum, aeb->lnum, av->vol_id);
 803                 }
 804         }
 805
 806         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 807         if (ret)
 808                 goto fail;
 809
 810         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 811         if (ret)
 812                 goto fail;
 813
 814         if (max_sqnum > ai->max_sqnum)
 815                 ai->max_sqnum = max_sqnum;
 816
 817         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 818                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 819
 820         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 821                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 822
 823         ubi_assert(list_empty(&free));
 824
 825         /*
 826          * If fastmap is leaking PEBs (must not happen), raise a
 827          * fat warning and fall back to scanning mode.
 828          * We do this here because in ubi_wl_init() it's too late
 829          * and we cannot fall back to scanning.
 830          */
 831         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 832                     ai->bad_peb_count - fm->used_blocks))
 833                 goto fail_bad;
 834
 835         return 0;
 836
 837 fail_bad:
 838         ret = UBI_BAD_FASTMAP;
 839 fail:
 840         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 841                 list_del(&tmp_aeb->u.list);
 842                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 843         }
 844         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 845                 list_del(&tmp_aeb->u.list);
 846                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 847         }
 848
 849         return ret;
 850 }
 851
 852 /**
 853  * ubi_scan_fastmap - scan the fastmap.
 854  * @ubi: UBI device object
 855  * @ai: UBI attach info to be filled
 856  * @fm_anchor: The fastmap starts at this PEB
 857  *
 858  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 859  * UBI_BAD_FASTMAP if one was found but is not usable.
 860  * < 0 indicates an internal error.
 861  */
 862 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 863                      int fm_anchor)
 864 {
 865         struct ubi_fm_sb *fmsb, *fmsb2;
 866         struct ubi_vid_hdr *vh;
 867         struct ubi_ec_hdr *ech;
 868         struct ubi_fastmap_layout *fm;
 869         int i, used_blocks, pnum, ret = 0;
 870         size_t fm_size;
 871         __be32 crc, tmp_crc;
 872         unsigned long long sqnum = 0;
 873
 874         down_write(&ubi->fm_protect);
 875         memset(ubi->fm_buf, 0, ubi->fm_size);
 876
 877         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 878         if (!fmsb) {
 879                 ret = -ENOMEM;
 880                 goto out;
 881         }
 882
 883         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 884         if (!fm) {
 885                 ret = -ENOMEM;
 886                 kfree(fmsb);
 887                 goto out;
 888         }
 889
 890         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 891         if (ret && ret != UBI_IO_BITFLIPS)
 892                 goto free_fm_sb;
 893         else if (ret == UBI_IO_BITFLIPS)
 894                 fm->to_be_tortured[0] = 1;
 895
 896         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 897                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 898                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 899                 ret = UBI_BAD_FASTMAP;
 900                 goto free_fm_sb;
 901         }
 902
 903         if (fmsb->version != UBI_FM_FMT_VERSION) {
 904                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 905                         fmsb->version, UBI_FM_FMT_VERSION);
 906                 ret = UBI_BAD_FASTMAP;
 907                 goto free_fm_sb;
 908         }
 909
 910         used_blocks = be32_to_cpu(fmsb->used_blocks);
 911         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 912                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 913                         used_blocks);
 914                 ret = UBI_BAD_FASTMAP;
 915                 goto free_fm_sb;
 916         }
 917
 918         fm_size = ubi->leb_size * used_blocks;
 919         if (fm_size != ubi->fm_size) {
 920                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 921                         fm_size, ubi->fm_size);
 922                 ret = UBI_BAD_FASTMAP;
 923                 goto free_fm_sb;
 924         }
 925
 926         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 927         if (!ech) {
 928                 ret = -ENOMEM;
 929                 goto free_fm_sb;
 930         }
 931
 932         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 933         if (!vh) {
 934                 ret = -ENOMEM;
 935                 goto free_hdr;
 936         }
 937
 938         for (i = 0; i < used_blocks; i++) {
 939                 int image_seq;
 940
 941                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 942
 943                 if (ubi_io_is_bad(ubi, pnum)) {
 944                         ret = UBI_BAD_FASTMAP;
 945                         goto free_hdr;
 946                 }
 947
 948                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 949                 if (ret && ret != UBI_IO_BITFLIPS) {
 950                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 951                                 i, pnum);
 952                         if (ret > 0)
 953                                 ret = UBI_BAD_FASTMAP;
 954                         goto free_hdr;
 955                 } else if (ret == UBI_IO_BITFLIPS)
 956                         fm->to_be_tortured[i] = 1;
 957
 958                 image_seq = be32_to_cpu(ech->image_seq);
 959                 if (!ubi->image_seq)
 960                         ubi->image_seq = image_seq;
 961
 962                 /*
 963                  * Older UBI implementations have image_seq set to zero, so
 964                  * we shouldn't fail if image_seq == 0.
 965                  */
 966                 if (image_seq && (image_seq != ubi->image_seq)) {
 967                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 968                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 969                         ret = UBI_BAD_FASTMAP;
 970                         goto free_hdr;
 971                 }
 972
 973                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 974                 if (ret && ret != UBI_IO_BITFLIPS) {
 975                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 976                                 i, pnum);
 977                         goto free_hdr;
 978                 }
 979
 980                 if (i == 0) {
 981                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 982                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 983                                         be32_to_cpu(vh->vol_id),
 984                                         UBI_FM_SB_VOLUME_ID);
 985                                 ret = UBI_BAD_FASTMAP;
 986                                 goto free_hdr;
 987                         }
 988                 } else {
 989                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 990                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 991                                         be32_to_cpu(vh->vol_id),
 992                                         UBI_FM_DATA_VOLUME_ID);
 993                                 ret = UBI_BAD_FASTMAP;
 994                                 goto free_hdr;
 995                         }
 996                 }
 997
 998                 if (sqnum < be64_to_cpu(vh->sqnum))
 999                         sqnum = be64_to_cpu(vh->sqnum);
1000
1001                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1002                                   ubi->leb_start, ubi->leb_size);
1003                 if (ret && ret != UBI_IO_BITFLIPS) {
1004                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1005                                 "err: %i)", i, pnum, ret);
1006                         goto free_hdr;
1007                 }
1008         }
1009
1010         kfree(fmsb);
1011         fmsb = NULL;
1012
1013         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1014         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1015         fmsb2->data_crc = 0;
1016         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1017         if (crc != tmp_crc) {
1018                 ubi_err(ubi, "fastmap data CRC is invalid");
1019                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1020                         tmp_crc, crc);
1021                 ret = UBI_BAD_FASTMAP;
1022                 goto free_hdr;
1023         }
1024
1025         fmsb2->sqnum = sqnum;
1026
1027         fm->used_blocks = used_blocks;
1028
1029         ret = ubi_attach_fastmap(ubi, ai, fm);
1030         if (ret) {
1031                 if (ret > 0)
1032                         ret = UBI_BAD_FASTMAP;
1033                 goto free_hdr;
1034         }
1035
1036         for (i = 0; i < used_blocks; i++) {
1037                 struct ubi_wl_entry *e;
1038
1039                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1040                 if (!e) {
1041                         while (i--)
1042                                 kfree(fm->e[i]);
1043
1044                         ret = -ENOMEM;
1045                         goto free_hdr;
1046                 }
1047
1048                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1049                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1050                 fm->e[i] = e;
1051         }
1052
1053         ubi->fm = fm;
1054         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1055         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1056         ubi_msg(ubi, "attached by fastmap");
1057         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1058         ubi_msg(ubi, "fastmap WL pool size: %d",
1059                 ubi->fm_wl_pool.max_size);
1060         ubi->fm_disabled = 0;
1061
1062         ubi_free_vid_hdr(ubi, vh);
1063         kfree(ech);
1064 out:
1065         up_write(&ubi->fm_protect);
1066         if (ret == UBI_BAD_FASTMAP)
1067                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1068         return ret;
1069
1070 free_hdr:
1071         ubi_free_vid_hdr(ubi, vh);
1072         kfree(ech);
1073 free_fm_sb:
1074         kfree(fmsb);
1075         kfree(fm);
1076         goto out;
1077 }
1078
1079 /**
1080  * ubi_write_fastmap - writes a fastmap.
1081  * @ubi: UBI device object
1082  * @new_fm: the to be written fastmap
1083  *
1084  * Returns 0 on success, < 0 indicates an internal error.
1085  */
1086 static int ubi_write_fastmap(struct ubi_device *ubi,
1087                              struct ubi_fastmap_layout *new_fm)
1088 {
1089         size_t fm_pos = 0;
1090         void *fm_raw;
1091         struct ubi_fm_sb *fmsb;
1092         struct ubi_fm_hdr *fmh;
1093         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1094         struct ubi_fm_ec *fec;
1095         struct ubi_fm_volhdr *fvh;
1096         struct ubi_fm_eba *feba;
1097         struct ubi_wl_entry *wl_e;
1098         struct ubi_volume *vol;
1099         struct ubi_vid_hdr *avhdr, *dvhdr;
1100         struct ubi_work *ubi_wrk;
1101         struct rb_node *tmp_rb;
1102         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1103         int scrub_peb_count, erase_peb_count;
1104         int *seen_pebs = NULL;
1105
1106         fm_raw = ubi->fm_buf;
1107         memset(ubi->fm_buf, 0, ubi->fm_size);
1108
1109         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1110         if (!avhdr) {
1111                 ret = -ENOMEM;
1112                 goto out;
1113         }
1114
1115         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1116         if (!dvhdr) {
1117                 ret = -ENOMEM;
1118                 goto out_kfree;
1119         }
1120
1121         seen_pebs = init_seen(ubi);
1122         if (IS_ERR(seen_pebs)) {
1123                 ret = PTR_ERR(seen_pebs);
1124                 goto out_kfree;
1125         }
1126
1127         spin_lock(&ubi->volumes_lock);
1128         spin_lock(&ubi->wl_lock);
1129
1130         fmsb = (struct ubi_fm_sb *)fm_raw;
1131         fm_pos += sizeof(*fmsb);
1132         ubi_assert(fm_pos <= ubi->fm_size);
1133
1134         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1135         fm_pos += sizeof(*fmh);
1136         ubi_assert(fm_pos <= ubi->fm_size);
1137
1138         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1139         fmsb->version = UBI_FM_FMT_VERSION;
1140         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1141         /* the max sqnum will be filled in while *reading* the fastmap */
1142         fmsb->sqnum = 0;
1143
1144         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1145         free_peb_count = 0;
1146         used_peb_count = 0;
1147         scrub_peb_count = 0;
1148         erase_peb_count = 0;
1149         vol_count = 0;
1150
1151         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1152         fm_pos += sizeof(*fmpl);
1153         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1154         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1155         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1156
1157         for (i = 0; i < ubi->fm_pool.size; i++) {
1158                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1159                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1160         }
1161
1162         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1163         fm_pos += sizeof(*fmpl_wl);
1164         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1165         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1166         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1167
1168         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1169                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1170                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1171         }
1172
1173         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1174                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1175
1176                 fec->pnum = cpu_to_be32(wl_e->pnum);
1177                 set_seen(ubi, wl_e->pnum, seen_pebs);
1178                 fec->ec = cpu_to_be32(wl_e->ec);
1179
1180                 free_peb_count++;
1181                 fm_pos += sizeof(*fec);
1182                 ubi_assert(fm_pos <= ubi->fm_size);
1183         }
1184         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1185
1186         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1187                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1188
1189                 fec->pnum = cpu_to_be32(wl_e->pnum);
1190                 set_seen(ubi, wl_e->pnum, seen_pebs);
1191                 fec->ec = cpu_to_be32(wl_e->ec);
1192
1193                 used_peb_count++;
1194                 fm_pos += sizeof(*fec);
1195                 ubi_assert(fm_pos <= ubi->fm_size);
1196         }
1197
1198         ubi_for_each_protected_peb(ubi, i, wl_e) {
1199                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1200
1201                 fec->pnum = cpu_to_be32(wl_e->pnum);
1202                 set_seen(ubi, wl_e->pnum, seen_pebs);
1203                 fec->ec = cpu_to_be32(wl_e->ec);
1204
1205                 used_peb_count++;
1206                 fm_pos += sizeof(*fec);
1207                 ubi_assert(fm_pos <= ubi->fm_size);
1208         }
1209         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1210
1211         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1212                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1213
1214                 fec->pnum = cpu_to_be32(wl_e->pnum);
1215                 set_seen(ubi, wl_e->pnum, seen_pebs);
1216                 fec->ec = cpu_to_be32(wl_e->ec);
1217
1218                 scrub_peb_count++;
1219                 fm_pos += sizeof(*fec);
1220                 ubi_assert(fm_pos <= ubi->fm_size);
1221         }
1222         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1223
1224
1225         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1226                 if (ubi_is_erase_work(ubi_wrk)) {
1227                         wl_e = ubi_wrk->e;
1228                         ubi_assert(wl_e);
1229
1230                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1231
1232                         fec->pnum = cpu_to_be32(wl_e->pnum);
1233                         set_seen(ubi, wl_e->pnum, seen_pebs);
1234                         fec->ec = cpu_to_be32(wl_e->ec);
1235
1236                         erase_peb_count++;
1237                         fm_pos += sizeof(*fec);
1238                         ubi_assert(fm_pos <= ubi->fm_size);
1239                 }
1240         }
1241         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1242
1243         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1244                 vol = ubi->volumes[i];
1245
1246                 if (!vol)
1247                         continue;
1248
1249                 vol_count++;
1250
1251                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1252                 fm_pos += sizeof(*fvh);
1253                 ubi_assert(fm_pos <= ubi->fm_size);
1254
1255                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1256                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1257                 fvh->vol_type = vol->vol_type;
1258                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1259                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1260                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1261
1262                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1263                         vol->vol_type == UBI_STATIC_VOLUME);
1264
1265                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1266                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1267                 ubi_assert(fm_pos <= ubi->fm_size);
1268
1269                 for (j = 0; j < vol->reserved_pebs; j++)
1270                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1271
1272                 feba->reserved_pebs = cpu_to_be32(j);
1273                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1274         }
1275         fmh->vol_count = cpu_to_be32(vol_count);
1276         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1277
1278         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1279         avhdr->lnum = 0;
1280
1281         spin_unlock(&ubi->wl_lock);
1282         spin_unlock(&ubi->volumes_lock);
1283
1284         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1285         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1286         if (ret) {
1287                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1288                 goto out_kfree;
1289         }
1290
1291         for (i = 0; i < new_fm->used_blocks; i++) {
1292                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1293                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1294                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1295         }
1296
1297         fmsb->data_crc = 0;
1298         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1299                                            ubi->fm_size));
1300
1301         for (i = 1; i < new_fm->used_blocks; i++) {
1302                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1303                 dvhdr->lnum = cpu_to_be32(i);
1304                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1305                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1306                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1307                 if (ret) {
1308                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1309                                 new_fm->e[i]->pnum);
1310                         goto out_kfree;
1311                 }
1312         }
1313
1314         for (i = 0; i < new_fm->used_blocks; i++) {
1315                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1316                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1317                 if (ret) {
1318                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1319                                 new_fm->e[i]->pnum);
1320                         goto out_kfree;
1321                 }
1322         }
1323
1324         ubi_assert(new_fm);
1325         ubi->fm = new_fm;
1326
1327         ret = self_check_seen(ubi, seen_pebs);
1328         dbg_bld("fastmap written!");
1329
1330 out_kfree:
1331         ubi_free_vid_hdr(ubi, avhdr);
1332         ubi_free_vid_hdr(ubi, dvhdr);
1333         free_seen(seen_pebs);
1334 out:
1335         return ret;
1336 }
1337
1338 /**
1339  * erase_block - Manually erase a PEB.
1340  * @ubi: UBI device object
1341  * @pnum: PEB to be erased
1342  *
1343  * Returns the new EC value on success, < 0 indicates an internal error.
1344  */
1345 static int erase_block(struct ubi_device *ubi, int pnum)
1346 {
1347         int ret;
1348         struct ubi_ec_hdr *ec_hdr;
1349         long long ec;
1350
1351         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1352         if (!ec_hdr)
1353                 return -ENOMEM;
1354
1355         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1356         if (ret < 0)
1357                 goto out;
1358         else if (ret && ret != UBI_IO_BITFLIPS) {
1359                 ret = -EINVAL;
1360                 goto out;
1361         }
1362
1363         ret = ubi_io_sync_erase(ubi, pnum, 0);
1364         if (ret < 0)
1365                 goto out;
1366
1367         ec = be64_to_cpu(ec_hdr->ec);
1368         ec += ret;
1369         if (ec > UBI_MAX_ERASECOUNTER) {
1370                 ret = -EINVAL;
1371                 goto out;
1372         }
1373
1374         ec_hdr->ec = cpu_to_be64(ec);
1375         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1376         if (ret < 0)
1377                 goto out;
1378
1379         ret = ec;
1380 out:
1381         kfree(ec_hdr);
1382         return ret;
1383 }
1384
1385 /**
1386  * invalidate_fastmap - destroys a fastmap.
1387  * @ubi: UBI device object
1388  *
1389  * This function ensures that upon next UBI attach a full scan
1390  * is issued. We need this if UBI is about to write a new fastmap
1391  * but is unable to do so. In this case we have two options:
1392  * a) Make sure that the current fastmap will not be usued upon
1393  * attach time and contine or b) fall back to RO mode to have the
1394  * current fastmap in a valid state.
1395  * Returns 0 on success, < 0 indicates an internal error.
1396  */
1397 static int invalidate_fastmap(struct ubi_device *ubi)
1398 {
1399         int ret;
1400         struct ubi_fastmap_layout *fm;
1401         struct ubi_wl_entry *e;
1402         struct ubi_vid_hdr *vh = NULL;
1403
1404         if (!ubi->fm)
1405                 return 0;
1406
1407         ubi->fm = NULL;
1408
1409         ret = -ENOMEM;
1410         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1411         if (!fm)
1412                 goto out;
1413
1414         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1415         if (!vh)
1416                 goto out_free_fm;
1417
1418         ret = -ENOSPC;
1419         e = ubi_wl_get_fm_peb(ubi, 1);
1420         if (!e)
1421                 goto out_free_fm;
1422
1423         /*
1424          * Create fake fastmap such that UBI will fall back
1425          * to scanning mode.
1426          */
1427         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1428         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1429         if (ret < 0) {
1430                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1431                 goto out_free_fm;
1432         }
1433
1434         fm->used_blocks = 1;
1435         fm->e[0] = e;
1436
1437         ubi->fm = fm;
1438
1439 out:
1440         ubi_free_vid_hdr(ubi, vh);
1441         return ret;
1442
1443 out_free_fm:
1444         kfree(fm);
1445         goto out;
1446 }
1447
1448 /**
1449  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1450  * WL sub-system.
1451  * @ubi: UBI device object
1452  * @fm: fastmap layout object
1453  */
1454 static void return_fm_pebs(struct ubi_device *ubi,
1455                            struct ubi_fastmap_layout *fm)
1456 {
1457         int i;
1458
1459         if (!fm)
1460                 return;
1461
1462         for (i = 0; i < fm->used_blocks; i++) {
1463                 if (fm->e[i]) {
1464                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1465                                           fm->to_be_tortured[i]);
1466                         fm->e[i] = NULL;
1467                 }
1468         }
1469 }
1470
1471 /**
1472  * ubi_update_fastmap - will be called by UBI if a volume changes or
1473  * a fastmap pool becomes full.
1474  * @ubi: UBI device object
1475  *
1476  * Returns 0 on success, < 0 indicates an internal error.
1477  */
1478 int ubi_update_fastmap(struct ubi_device *ubi)
1479 {
1480         int ret, i, j;
1481         struct ubi_fastmap_layout *new_fm, *old_fm;
1482         struct ubi_wl_entry *tmp_e;
1483
1484         down_write(&ubi->fm_protect);
1485
1486         ubi_refill_pools(ubi);
1487
1488         if (ubi->ro_mode || ubi->fm_disabled) {
1489                 up_write(&ubi->fm_protect);
1490                 return 0;
1491         }
1492
1493         ret = ubi_ensure_anchor_pebs(ubi);
1494         if (ret) {
1495                 up_write(&ubi->fm_protect);
1496                 return ret;
1497         }
1498
1499         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1500         if (!new_fm) {
1501                 up_write(&ubi->fm_protect);
1502                 return -ENOMEM;
1503         }
1504
1505         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1506         old_fm = ubi->fm;
1507         ubi->fm = NULL;
1508
1509         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1510                 ubi_err(ubi, "fastmap too large");
1511                 ret = -ENOSPC;
1512                 goto err;
1513         }
1514
1515         for (i = 1; i < new_fm->used_blocks; i++) {
1516                 spin_lock(&ubi->wl_lock);
1517                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1518                 spin_unlock(&ubi->wl_lock);
1519
1520                 if (!tmp_e) {
1521                         if (old_fm && old_fm->e[i]) {
1522                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1523                                 if (ret < 0) {
1524                                         ubi_err(ubi, "could not erase old fastmap PEB");
1525
1526                                         for (j = 1; j < i; j++) {
1527                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1528                                                                   j, 0);
1529                                                 new_fm->e[j] = NULL;
1530                                         }
1531                                         goto err;
1532                                 }
1533                                 new_fm->e[i] = old_fm->e[i];
1534                                 old_fm->e[i] = NULL;
1535                         } else {
1536                                 ubi_err(ubi, "could not get any free erase block");
1537
1538                                 for (j = 1; j < i; j++) {
1539                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1540                                         new_fm->e[j] = NULL;
1541                                 }
1542
1543                                 ret = -ENOSPC;
1544                                 goto err;
1545                         }
1546                 } else {
1547                         new_fm->e[i] = tmp_e;
1548
1549                         if (old_fm && old_fm->e[i]) {
1550                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1551                                                   old_fm->to_be_tortured[i]);
1552                                 old_fm->e[i] = NULL;
1553                         }
1554                 }
1555         }
1556
1557         /* Old fastmap is larger than the new one */
1558         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1559                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1560                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1561                                           old_fm->to_be_tortured[i]);
1562                         old_fm->e[i] = NULL;
1563                 }
1564         }
1565
1566         spin_lock(&ubi->wl_lock);
1567         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1568         spin_unlock(&ubi->wl_lock);
1569
1570         if (old_fm) {
1571                 /* no fresh anchor PEB was found, reuse the old one */
1572                 if (!tmp_e) {
1573                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1574                         if (ret < 0) {
1575                                 ubi_err(ubi, "could not erase old anchor PEB");
1576
1577                                 for (i = 1; i < new_fm->used_blocks; i++) {
1578                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1579                                                           i, 0);
1580                                         new_fm->e[i] = NULL;
1581                                 }
1582                                 goto err;
1583                         }
1584                         new_fm->e[0] = old_fm->e[0];
1585                         new_fm->e[0]->ec = ret;
1586                         old_fm->e[0] = NULL;
1587                 } else {
1588                         /* we've got a new anchor PEB, return the old one */
1589                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1590                                           old_fm->to_be_tortured[0]);
1591                         new_fm->e[0] = tmp_e;
1592                         old_fm->e[0] = NULL;
1593                 }
1594         } else {
1595                 if (!tmp_e) {
1596                         ubi_err(ubi, "could not find any anchor PEB");
1597
1598                         for (i = 1; i < new_fm->used_blocks; i++) {
1599                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1600                                 new_fm->e[i] = NULL;
1601                         }
1602
1603                         ret = -ENOSPC;
1604                         goto err;
1605                 }
1606                 new_fm->e[0] = tmp_e;
1607         }
1608
1609         down_write(&ubi->work_sem);
1610         down_write(&ubi->fm_eba_sem);
1611         ret = ubi_write_fastmap(ubi, new_fm);
1612         up_write(&ubi->fm_eba_sem);
1613         up_write(&ubi->work_sem);
1614
1615         if (ret)
1616                 goto err;
1617
1618 out_unlock:
1619         up_write(&ubi->fm_protect);
1620         kfree(old_fm);
1621         return ret;
1622
1623 err:
1624         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1625
1626         ret = invalidate_fastmap(ubi);
1627         if (ret < 0) {
1628                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1629                 ubi_ro_mode(ubi);
1630         } else {
1631                 return_fm_pebs(ubi, old_fm);
1632                 return_fm_pebs(ubi, new_fm);
1633                 ret = 0;
1634         }
1635
1636         kfree(new_fm);
1637         goto out_unlock;
1638 }