drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Author: Richard Weinberger <richard@nod.at>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include <linux/crc32.h>
  17 #include "ubi.h"
  18
  19 /**
  20  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  21  * @ubi: UBI device description object
  22  */
  23 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  24 {
  25         size_t size;
  26
  27         size = sizeof(struct ubi_fm_hdr) + \
  28                 sizeof(struct ubi_fm_scan_pool) + \
  29                 sizeof(struct ubi_fm_scan_pool) + \
  30                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
  31                 (sizeof(struct ubi_fm_eba) + \
  32                 (ubi->peb_count * sizeof(__be32))) + \
  33                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  34         return roundup(size, ubi->leb_size);
  35 }
  36
  37
  38 /**
  39  * new_fm_vhdr - allocate a new volume header for fastmap usage.
  40  * @ubi: UBI device description object
  41  * @vol_id: the VID of the new header
  42  *
  43  * Returns a new struct ubi_vid_hdr on success.
  44  * NULL indicates out of memory.
  45  */
  46 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
  47 {
  48         struct ubi_vid_hdr *new;
  49
  50         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
  51         if (!new)
  52                 goto out;
  53
  54         new->vol_type = UBI_VID_DYNAMIC;
  55         new->vol_id = cpu_to_be32(vol_id);
  56
  57         /* UBI implementations without fastmap support have to delete the
  58          * fastmap.
  59          */
  60         new->compat = UBI_COMPAT_DELETE;
  61
  62 out:
  63         return new;
  64 }
  65
  66 /**
  67  * add_aeb - create and add a attach erase block to a given list.
  68  * @ai: UBI attach info object
  69  * @list: the target list
  70  * @pnum: PEB number of the new attach erase block
  71  * @ec: erease counter of the new LEB
  72  * @scrub: scrub this PEB after attaching
  73  *
  74  * Returns 0 on success, < 0 indicates an internal error.
  75  */
  76 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
  77                    int pnum, int ec, int scrub)
  78 {
  79         struct ubi_ainf_peb *aeb;
  80
  81         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
  82         if (!aeb)
  83                 return -ENOMEM;
  84
  85         aeb->pnum = pnum;
  86         aeb->ec = ec;
  87         aeb->lnum = -1;
  88         aeb->scrub = scrub;
  89         aeb->copy_flag = aeb->sqnum = 0;
  90
  91         ai->ec_sum += aeb->ec;
  92         ai->ec_count++;
  93
  94         if (ai->max_ec < aeb->ec)
  95                 ai->max_ec = aeb->ec;
  96
  97         if (ai->min_ec > aeb->ec)
  98                 ai->min_ec = aeb->ec;
  99
 100         list_add_tail(&aeb->u.list, list);
 101
 102         return 0;
 103 }
 104
 105 /**
 106  * add_vol - create and add a new volume to ubi_attach_info.
 107  * @ai: ubi_attach_info object
 108  * @vol_id: VID of the new volume
 109  * @used_ebs: number of used EBS
 110  * @data_pad: data padding value of the new volume
 111  * @vol_type: volume type
 112  * @last_eb_bytes: number of bytes in the last LEB
 113  *
 114  * Returns the new struct ubi_ainf_volume on success.
 115  * NULL indicates an error.
 116  */
 117 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 118                                        int used_ebs, int data_pad, u8 vol_type,
 119                                        int last_eb_bytes)
 120 {
 121         struct ubi_ainf_volume *av;
 122         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 123
 124         while (*p) {
 125                 parent = *p;
 126                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 127
 128                 if (vol_id > av->vol_id)
 129                         p = &(*p)->rb_left;
 130                 else if (vol_id > av->vol_id)
 131                         p = &(*p)->rb_right;
 132         }
 133
 134         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 135         if (!av)
 136                 goto out;
 137
 138         av->highest_lnum = av->leb_count = 0;
 139         av->vol_id = vol_id;
 140         av->used_ebs = used_ebs;
 141         av->data_pad = data_pad;
 142         av->last_data_size = last_eb_bytes;
 143         av->compat = 0;
 144         av->vol_type = vol_type;
 145         av->root = RB_ROOT;
 146
 147         dbg_bld("found volume (ID %i)", vol_id);
 148
 149         rb_link_node(&av->rb, parent, p);
 150         rb_insert_color(&av->rb, &ai->volumes);
 151
 152 out:
 153         return av;
 154 }
 155
 156 /**
 157  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 158  * from it's original list.
 159  * @ai: ubi_attach_info object
 160  * @aeb: the to be assigned SEB
 161  * @av: target scan volume
 162  */
 163 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 164                              struct ubi_ainf_peb *aeb,
 165                              struct ubi_ainf_volume *av)
 166 {
 167         struct ubi_ainf_peb *tmp_aeb;
 168         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 169
 170         p = &av->root.rb_node;
 171         while (*p) {
 172                 parent = *p;
 173
 174                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 175                 if (aeb->lnum != tmp_aeb->lnum) {
 176                         if (aeb->lnum < tmp_aeb->lnum)
 177                                 p = &(*p)->rb_left;
 178                         else
 179                                 p = &(*p)->rb_right;
 180
 181                         continue;
 182                 } else
 183                         break;
 184         }
 185
 186         list_del(&aeb->u.list);
 187         av->leb_count++;
 188
 189         rb_link_node(&aeb->u.rb, parent, p);
 190         rb_insert_color(&aeb->u.rb, &av->root);
 191 }
 192
 193 /**
 194  * update_vol - inserts or updates a LEB which was found a pool.
 195  * @ubi: the UBI device object
 196  * @ai: attach info object
 197  * @av: the volume this LEB belongs to
 198  * @new_vh: the volume header derived from new_aeb
 199  * @new_aeb: the AEB to be examined
 200  *
 201  * Returns 0 on success, < 0 indicates an internal error.
 202  */
 203 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 204                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 205                       struct ubi_ainf_peb *new_aeb)
 206 {
 207         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 208         struct ubi_ainf_peb *aeb, *victim;
 209         int cmp_res;
 210
 211         while (*p) {
 212                 parent = *p;
 213                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 214
 215                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 216                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 217                                 p = &(*p)->rb_left;
 218                         else
 219                                 p = &(*p)->rb_right;
 220
 221                         continue;
 222                 }
 223
 224                 /* This case can happen if the fastmap gets written
 225                  * because of a volume change (creation, deletion, ..).
 226                  * Then a PEB can be within the persistent EBA and the pool.
 227                  */
 228                 if (aeb->pnum == new_aeb->pnum) {
 229                         ubi_assert(aeb->lnum == new_aeb->lnum);
 230                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 231
 232                         return 0;
 233                 }
 234
 235                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 236                 if (cmp_res < 0)
 237                         return cmp_res;
 238
 239                 /* new_aeb is newer */
 240                 if (cmp_res & 1) {
 241                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 242                                 GFP_KERNEL);
 243                         if (!victim)
 244                                 return -ENOMEM;
 245
 246                         victim->ec = aeb->ec;
 247                         victim->pnum = aeb->pnum;
 248                         list_add_tail(&victim->u.list, &ai->erase);
 249
 250                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 251                                 av->last_data_size = \
 252                                         be32_to_cpu(new_vh->data_size);
 253
 254                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 255                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 256
 257                         aeb->ec = new_aeb->ec;
 258                         aeb->pnum = new_aeb->pnum;
 259                         aeb->copy_flag = new_vh->copy_flag;
 260                         aeb->scrub = new_aeb->scrub;
 261                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 262
 263                 /* new_aeb is older */
 264                 } else {
 265                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 266                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 267                         list_add_tail(&new_aeb->u.list, &ai->erase);
 268                 }
 269
 270                 return 0;
 271         }
 272         /* This LEB is new, let's add it to the volume */
 273
 274         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 275                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 276                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 277         }
 278
 279         if (av->vol_type == UBI_STATIC_VOLUME)
 280                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 281
 282         av->leb_count++;
 283
 284         rb_link_node(&new_aeb->u.rb, parent, p);
 285         rb_insert_color(&new_aeb->u.rb, &av->root);
 286
 287         return 0;
 288 }
 289
 290 /**
 291  * process_pool_aeb - we found a non-empty PEB in a pool.
 292  * @ubi: UBI device object
 293  * @ai: attach info object
 294  * @new_vh: the volume header derived from new_aeb
 295  * @new_aeb: the AEB to be examined
 296  *
 297  * Returns 0 on success, < 0 indicates an internal error.
 298  */
 299 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 300                             struct ubi_vid_hdr *new_vh,
 301                             struct ubi_ainf_peb *new_aeb)
 302 {
 303         struct ubi_ainf_volume *av, *tmp_av = NULL;
 304         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 305         int found = 0;
 306
 307         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 308                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 309                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 310
 311                 return 0;
 312         }
 313
 314         /* Find the volume this SEB belongs to */
 315         while (*p) {
 316                 parent = *p;
 317                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 318
 319                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 320                         p = &(*p)->rb_left;
 321                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 322                         p = &(*p)->rb_right;
 323                 else {
 324                         found = 1;
 325                         break;
 326                 }
 327         }
 328
 329         if (found)
 330                 av = tmp_av;
 331         else {
 332                 ubi_err("orphaned volume in fastmap pool!");
 333                 return UBI_BAD_FASTMAP;
 334         }
 335
 336         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 337
 338         return update_vol(ubi, ai, av, new_vh, new_aeb);
 339 }
 340
 341 /**
 342  * unmap_peb - unmap a PEB.
 343  * If fastmap detects a free PEB in the pool it has to check whether
 344  * this PEB has been unmapped after writing the fastmap.
 345  *
 346  * @ai: UBI attach info object
 347  * @pnum: The PEB to be unmapped
 348  */
 349 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 350 {
 351         struct ubi_ainf_volume *av;
 352         struct rb_node *node, *node2;
 353         struct ubi_ainf_peb *aeb;
 354
 355         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 356                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 357
 358                 for (node2 = rb_first(&av->root); node2;
 359                      node2 = rb_next(node2)) {
 360                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 361                         if (aeb->pnum == pnum) {
 362                                 rb_erase(&aeb->u.rb, &av->root);
 363                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 364                                 return;
 365                         }
 366                 }
 367         }
 368 }
 369
 370 /**
 371  * scan_pool - scans a pool for changed (no longer empty PEBs).
 372  * @ubi: UBI device object
 373  * @ai: attach info object
 374  * @pebs: an array of all PEB numbers in the to be scanned pool
 375  * @pool_size: size of the pool (number of entries in @pebs)
 376  * @max_sqnum: pointer to the maximal sequence number
 377  * @eba_orphans: list of PEBs which need to be scanned
 378  * @free: list of PEBs which are most likely free (and go into @ai->free)
 379  *
 380  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 381  * < 0 indicates an internal error.
 382  */
 383 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 384                      int *pebs, int pool_size, unsigned long long *max_sqnum,
 385                      struct list_head *eba_orphans, struct list_head *free)
 386 {
 387         struct ubi_vid_hdr *vh;
 388         struct ubi_ec_hdr *ech;
 389         struct ubi_ainf_peb *new_aeb, *tmp_aeb;
 390         int i, pnum, err, found_orphan, ret = 0;
 391
 392         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 393         if (!ech)
 394                 return -ENOMEM;
 395
 396         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 397         if (!vh) {
 398                 kfree(ech);
 399                 return -ENOMEM;
 400         }
 401
 402         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 403
 404         /*
 405          * Now scan all PEBs in the pool to find changes which have been made
 406          * after the creation of the fastmap
 407          */
 408         for (i = 0; i < pool_size; i++) {
 409                 int scrub = 0;
 410                 int image_seq;
 411
 412                 pnum = be32_to_cpu(pebs[i]);
 413
 414                 if (ubi_io_is_bad(ubi, pnum)) {
 415                         ubi_err("bad PEB in fastmap pool!");
 416                         ret = UBI_BAD_FASTMAP;
 417                         goto out;
 418                 }
 419
 420                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 421                 if (err && err != UBI_IO_BITFLIPS) {
 422                         ubi_err("unable to read EC header! PEB:%i err:%i",
 423                                 pnum, err);
 424                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 425                         goto out;
 426                 } else if (ret == UBI_IO_BITFLIPS)
 427                         scrub = 1;
 428
 429                 /*
 430                  * Older UBI implementations have image_seq set to zero, so
 431                  * we shouldn't fail if image_seq == 0.
 432                  */
 433                 image_seq = be32_to_cpu(ech->image_seq);
 434
 435                 if (image_seq && (image_seq != ubi->image_seq)) {
 436                         ubi_err("bad image seq: 0x%x, expected: 0x%x",
 437                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 438                         ret = UBI_BAD_FASTMAP;
 439                         goto out;
 440                 }
 441
 442                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 443                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 444                         unsigned long long ec = be64_to_cpu(ech->ec);
 445                         unmap_peb(ai, pnum);
 446                         dbg_bld("Adding PEB to free: %i", pnum);
 447                         if (err == UBI_IO_FF_BITFLIPS)
 448                                 add_aeb(ai, free, pnum, ec, 1);
 449                         else
 450                                 add_aeb(ai, free, pnum, ec, 0);
 451                         continue;
 452                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 453                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 454
 455                         if (err == UBI_IO_BITFLIPS)
 456                                 scrub = 1;
 457
 458                         found_orphan = 0;
 459                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
 460                                 if (tmp_aeb->pnum == pnum) {
 461                                         found_orphan = 1;
 462                                         break;
 463                                 }
 464                         }
 465                         if (found_orphan) {
 466                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 467                                 list_del(&tmp_aeb->u.list);
 468                         }
 469
 470                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 471                                                    GFP_KERNEL);
 472                         if (!new_aeb) {
 473                                 ret = -ENOMEM;
 474                                 goto out;
 475                         }
 476
 477                         new_aeb->ec = be64_to_cpu(ech->ec);
 478                         new_aeb->pnum = pnum;
 479                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 480                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 481                         new_aeb->copy_flag = vh->copy_flag;
 482                         new_aeb->scrub = scrub;
 483
 484                         if (*max_sqnum < new_aeb->sqnum)
 485                                 *max_sqnum = new_aeb->sqnum;
 486
 487                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 488                         if (err) {
 489                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 490                                 goto out;
 491                         }
 492                 } else {
 493                         /* We are paranoid and fall back to scanning mode */
 494                         ubi_err("fastmap pool PEBs contains damaged PEBs!");
 495                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 496                         goto out;
 497                 }
 498
 499         }
 500
 501 out:
 502         ubi_free_vid_hdr(ubi, vh);
 503         kfree(ech);
 504         return ret;
 505 }
 506
 507 /**
 508  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 509  * @ai: The UBI attach info object
 510  */
 511 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 512 {
 513         struct ubi_ainf_peb *aeb;
 514         struct ubi_ainf_volume *av;
 515         struct rb_node *rb1, *rb2;
 516         int n = 0;
 517
 518         list_for_each_entry(aeb, &ai->erase, u.list)
 519                 n++;
 520
 521         list_for_each_entry(aeb, &ai->free, u.list)
 522                 n++;
 523
 524          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 525                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 526                         n++;
 527
 528         return n;
 529 }
 530
 531 /**
 532  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 533  * @ubi: UBI device object
 534  * @ai: UBI attach info object
 535  * @fm: the fastmap to be attached
 536  *
 537  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 538  * < 0 indicates an internal error.
 539  */
 540 static int ubi_attach_fastmap(struct ubi_device *ubi,
 541                               struct ubi_attach_info *ai,
 542                               struct ubi_fastmap_layout *fm)
 543 {
 544         struct list_head used, eba_orphans, free;
 545         struct ubi_ainf_volume *av;
 546         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 547         struct ubi_ec_hdr *ech;
 548         struct ubi_fm_sb *fmsb;
 549         struct ubi_fm_hdr *fmhdr;
 550         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 551         struct ubi_fm_ec *fmec;
 552         struct ubi_fm_volhdr *fmvhdr;
 553         struct ubi_fm_eba *fm_eba;
 554         int ret, i, j, pool_size, wl_pool_size;
 555         size_t fm_pos = 0, fm_size = ubi->fm_size;
 556         unsigned long long max_sqnum = 0;
 557         void *fm_raw = ubi->fm_buf;
 558
 559         INIT_LIST_HEAD(&used);
 560         INIT_LIST_HEAD(&free);
 561         INIT_LIST_HEAD(&eba_orphans);
 562         INIT_LIST_HEAD(&ai->corr);
 563         INIT_LIST_HEAD(&ai->free);
 564         INIT_LIST_HEAD(&ai->erase);
 565         INIT_LIST_HEAD(&ai->alien);
 566         ai->volumes = RB_ROOT;
 567         ai->min_ec = UBI_MAX_ERASECOUNTER;
 568
 569         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
 570                                                sizeof(struct ubi_ainf_peb),
 571                                                0, 0, NULL);
 572         if (!ai->aeb_slab_cache) {
 573                 ret = -ENOMEM;
 574                 goto fail;
 575         }
 576
 577         fmsb = (struct ubi_fm_sb *)(fm_raw);
 578         ai->max_sqnum = fmsb->sqnum;
 579         fm_pos += sizeof(struct ubi_fm_sb);
 580         if (fm_pos >= fm_size)
 581                 goto fail_bad;
 582
 583         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 584         fm_pos += sizeof(*fmhdr);
 585         if (fm_pos >= fm_size)
 586                 goto fail_bad;
 587
 588         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 589                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
 590                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 591                 goto fail_bad;
 592         }
 593
 594         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 595         fm_pos += sizeof(*fmpl1);
 596         if (fm_pos >= fm_size)
 597                 goto fail_bad;
 598         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 599                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 600                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 601                 goto fail_bad;
 602         }
 603
 604         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 605         fm_pos += sizeof(*fmpl2);
 606         if (fm_pos >= fm_size)
 607                 goto fail_bad;
 608         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 609                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 610                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 611                 goto fail_bad;
 612         }
 613
 614         pool_size = be16_to_cpu(fmpl1->size);
 615         wl_pool_size = be16_to_cpu(fmpl2->size);
 616         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 617         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 618
 619         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 620                 ubi_err("bad pool size: %i", pool_size);
 621                 goto fail_bad;
 622         }
 623
 624         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 625                 ubi_err("bad WL pool size: %i", wl_pool_size);
 626                 goto fail_bad;
 627         }
 628
 629
 630         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 631             fm->max_pool_size < 0) {
 632                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
 633                 goto fail_bad;
 634         }
 635
 636         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 637             fm->max_wl_pool_size < 0) {
 638                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
 639                 goto fail_bad;
 640         }
 641
 642         /* read EC values from free list */
 643         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 644                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 645                 fm_pos += sizeof(*fmec);
 646                 if (fm_pos >= fm_size)
 647                         goto fail_bad;
 648
 649                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 650                         be32_to_cpu(fmec->ec), 0);
 651         }
 652
 653         /* read EC values from used list */
 654         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 655                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 656                 fm_pos += sizeof(*fmec);
 657                 if (fm_pos >= fm_size)
 658                         goto fail_bad;
 659
 660                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 661                         be32_to_cpu(fmec->ec), 0);
 662         }
 663
 664         /* read EC values from scrub list */
 665         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 666                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 667                 fm_pos += sizeof(*fmec);
 668                 if (fm_pos >= fm_size)
 669                         goto fail_bad;
 670
 671                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 672                         be32_to_cpu(fmec->ec), 1);
 673         }
 674
 675         /* read EC values from erase list */
 676         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 677                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 678                 fm_pos += sizeof(*fmec);
 679                 if (fm_pos >= fm_size)
 680                         goto fail_bad;
 681
 682                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 683                         be32_to_cpu(fmec->ec), 1);
 684         }
 685
 686         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 687         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 688
 689         /* Iterate over all volumes and read their EBA table */
 690         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 691                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 692                 fm_pos += sizeof(*fmvhdr);
 693                 if (fm_pos >= fm_size)
 694                         goto fail_bad;
 695
 696                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 697                         ubi_err("bad fastmap vol header magic: 0x%x, " \
 698                                 "expected: 0x%x",
 699                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 700                         goto fail_bad;
 701                 }
 702
 703                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 704                              be32_to_cpu(fmvhdr->used_ebs),
 705                              be32_to_cpu(fmvhdr->data_pad),
 706                              fmvhdr->vol_type,
 707                              be32_to_cpu(fmvhdr->last_eb_bytes));
 708
 709                 if (!av)
 710                         goto fail_bad;
 711
 712                 ai->vols_found++;
 713                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 714                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 715
 716                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 717                 fm_pos += sizeof(*fm_eba);
 718                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 719                 if (fm_pos >= fm_size)
 720                         goto fail_bad;
 721
 722                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 723                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
 724                                 "expected: 0x%x",
 725                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 726                         goto fail_bad;
 727                 }
 728
 729                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 730                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 731
 732                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 733                                 continue;
 734
 735                         aeb = NULL;
 736                         list_for_each_entry(tmp_aeb, &used, u.list) {
 737                                 if (tmp_aeb->pnum == pnum) {
 738                                         aeb = tmp_aeb;
 739                                         break;
 740                                 }
 741                         }
 742
 743                         /* This can happen if a PEB is already in an EBA known
 744                          * by this fastmap but the PEB itself is not in the used
 745                          * list.
 746                          * In this case the PEB can be within the fastmap pool
 747                          * or while writing the fastmap it was in the protection
 748                          * queue.
 749                          */
 750                         if (!aeb) {
 751                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 752                                                        GFP_KERNEL);
 753                                 if (!aeb) {
 754                                         ret = -ENOMEM;
 755
 756                                         goto fail;
 757                                 }
 758
 759                                 aeb->lnum = j;
 760                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 761                                 aeb->ec = -1;
 762                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 763                                 list_add_tail(&aeb->u.list, &eba_orphans);
 764                                 continue;
 765                         }
 766
 767                         aeb->lnum = j;
 768
 769                         if (av->highest_lnum <= aeb->lnum)
 770                                 av->highest_lnum = aeb->lnum;
 771
 772                         assign_aeb_to_av(ai, aeb, av);
 773
 774                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 775                                 aeb->pnum, aeb->lnum, av->vol_id);
 776                 }
 777
 778                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 779                 if (!ech) {
 780                         ret = -ENOMEM;
 781                         goto fail;
 782                 }
 783
 784                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 785                                          u.list) {
 786                         int err;
 787
 788                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 789                                 ubi_err("bad PEB in fastmap EBA orphan list");
 790                                 ret = UBI_BAD_FASTMAP;
 791                                 kfree(ech);
 792                                 goto fail;
 793                         }
 794
 795                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 796                         if (err && err != UBI_IO_BITFLIPS) {
 797                                 ubi_err("unable to read EC header! PEB:%i " \
 798                                         "err:%i", tmp_aeb->pnum, err);
 799                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 800                                 kfree(ech);
 801
 802                                 goto fail;
 803                         } else if (err == UBI_IO_BITFLIPS)
 804                                 tmp_aeb->scrub = 1;
 805
 806                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 807                         assign_aeb_to_av(ai, tmp_aeb, av);
 808                 }
 809
 810                 kfree(ech);
 811         }
 812
 813         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 814                         &eba_orphans, &free);
 815         if (ret)
 816                 goto fail;
 817
 818         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 819                         &eba_orphans, &free);
 820         if (ret)
 821                 goto fail;
 822
 823         if (max_sqnum > ai->max_sqnum)
 824                 ai->max_sqnum = max_sqnum;
 825
 826         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 827                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 828
 829         /*
 830          * If fastmap is leaking PEBs (must not happen), raise a
 831          * fat warning and fall back to scanning mode.
 832          * We do this here because in ubi_wl_init() it's too late
 833          * and we cannot fall back to scanning.
 834          */
 835         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 836                     ai->bad_peb_count - fm->used_blocks))
 837                 goto fail_bad;
 838
 839         return 0;
 840
 841 fail_bad:
 842         ret = UBI_BAD_FASTMAP;
 843 fail:
 844         return ret;
 845 }
 846
 847 /**
 848  * ubi_scan_fastmap - scan the fastmap.
 849  * @ubi: UBI device object
 850  * @ai: UBI attach info to be filled
 851  * @fm_anchor: The fastmap starts at this PEB
 852  *
 853  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 854  * UBI_BAD_FASTMAP if one was found but is not usable.
 855  * < 0 indicates an internal error.
 856  */
 857 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 858                      int fm_anchor)
 859 {
 860         struct ubi_fm_sb *fmsb, *fmsb2;
 861         struct ubi_vid_hdr *vh;
 862         struct ubi_ec_hdr *ech;
 863         struct ubi_fastmap_layout *fm;
 864         int i, used_blocks, pnum, ret = 0;
 865         size_t fm_size;
 866         __be32 crc, tmp_crc;
 867         unsigned long long sqnum = 0;
 868
 869         mutex_lock(&ubi->fm_mutex);
 870         memset(ubi->fm_buf, 0, ubi->fm_size);
 871
 872         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 873         if (!fmsb) {
 874                 ret = -ENOMEM;
 875                 goto out;
 876         }
 877
 878         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 879         if (!fm) {
 880                 ret = -ENOMEM;
 881                 kfree(fmsb);
 882                 goto out;
 883         }
 884
 885         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 886         if (ret && ret != UBI_IO_BITFLIPS)
 887                 goto free_fm_sb;
 888         else if (ret == UBI_IO_BITFLIPS)
 889                 fm->to_be_tortured[0] = 1;
 890
 891         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 892                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
 893                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 894                 ret = UBI_BAD_FASTMAP;
 895                 goto free_fm_sb;
 896         }
 897
 898         if (fmsb->version != UBI_FM_FMT_VERSION) {
 899                 ubi_err("bad fastmap version: %i, expected: %i",
 900                         fmsb->version, UBI_FM_FMT_VERSION);
 901                 ret = UBI_BAD_FASTMAP;
 902                 goto free_fm_sb;
 903         }
 904
 905         used_blocks = be32_to_cpu(fmsb->used_blocks);
 906         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 907                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
 908                 ret = UBI_BAD_FASTMAP;
 909                 goto free_fm_sb;
 910         }
 911
 912         fm_size = ubi->leb_size * used_blocks;
 913         if (fm_size != ubi->fm_size) {
 914                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
 915                         ubi->fm_size);
 916                 ret = UBI_BAD_FASTMAP;
 917                 goto free_fm_sb;
 918         }
 919
 920         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 921         if (!ech) {
 922                 ret = -ENOMEM;
 923                 goto free_fm_sb;
 924         }
 925
 926         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 927         if (!vh) {
 928                 ret = -ENOMEM;
 929                 goto free_hdr;
 930         }
 931
 932         for (i = 0; i < used_blocks; i++) {
 933                 int image_seq;
 934
 935                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 936
 937                 if (ubi_io_is_bad(ubi, pnum)) {
 938                         ret = UBI_BAD_FASTMAP;
 939                         goto free_hdr;
 940                 }
 941
 942                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 943                 if (ret && ret != UBI_IO_BITFLIPS) {
 944                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
 945                                 i, pnum);
 946                         if (ret > 0)
 947                                 ret = UBI_BAD_FASTMAP;
 948                         goto free_hdr;
 949                 } else if (ret == UBI_IO_BITFLIPS)
 950                         fm->to_be_tortured[i] = 1;
 951
 952                 image_seq = be32_to_cpu(ech->image_seq);
 953                 if (!ubi->image_seq)
 954                         ubi->image_seq = image_seq;
 955
 956                 /*
 957                  * Older UBI implementations have image_seq set to zero, so
 958                  * we shouldn't fail if image_seq == 0.
 959                  */
 960                 if (image_seq && (image_seq != ubi->image_seq)) {
 961                         ubi_err("wrong image seq:%d instead of %d",
 962                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 963                         ret = UBI_BAD_FASTMAP;
 964                         goto free_hdr;
 965                 }
 966
 967                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 968                 if (ret && ret != UBI_IO_BITFLIPS) {
 969                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
 970                                 i, pnum);
 971                         goto free_hdr;
 972                 }
 973
 974                 if (i == 0) {
 975                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 976                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
 977                                         " expected: 0x%x",
 978                                         be32_to_cpu(vh->vol_id),
 979                                         UBI_FM_SB_VOLUME_ID);
 980                                 ret = UBI_BAD_FASTMAP;
 981                                 goto free_hdr;
 982                         }
 983                 } else {
 984                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 985                                 ubi_err("bad fastmap data vol_id: 0x%x," \
 986                                         " expected: 0x%x",
 987                                         be32_to_cpu(vh->vol_id),
 988                                         UBI_FM_DATA_VOLUME_ID);
 989                                 ret = UBI_BAD_FASTMAP;
 990                                 goto free_hdr;
 991                         }
 992                 }
 993
 994                 if (sqnum < be64_to_cpu(vh->sqnum))
 995                         sqnum = be64_to_cpu(vh->sqnum);
 996
 997                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
 998                                   ubi->leb_start, ubi->leb_size);
 999                 if (ret && ret != UBI_IO_BITFLIPS) {
1000                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
1001                                 "err: %i)", i, pnum, ret);
1002                         goto free_hdr;
1003                 }
1004         }
1005
1006         kfree(fmsb);
1007         fmsb = NULL;
1008
1009         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1010         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1011         fmsb2->data_crc = 0;
1012         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1013         if (crc != tmp_crc) {
1014                 ubi_err("fastmap data CRC is invalid");
1015                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1016                 ret = UBI_BAD_FASTMAP;
1017                 goto free_hdr;
1018         }
1019
1020         fmsb2->sqnum = sqnum;
1021
1022         fm->used_blocks = used_blocks;
1023
1024         ret = ubi_attach_fastmap(ubi, ai, fm);
1025         if (ret) {
1026                 if (ret > 0)
1027                         ret = UBI_BAD_FASTMAP;
1028                 goto free_hdr;
1029         }
1030
1031         for (i = 0; i < used_blocks; i++) {
1032                 struct ubi_wl_entry *e;
1033
1034                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1035                 if (!e) {
1036                         while (i--)
1037                                 kfree(fm->e[i]);
1038
1039                         ret = -ENOMEM;
1040                         goto free_hdr;
1041                 }
1042
1043                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1044                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1045                 fm->e[i] = e;
1046         }
1047
1048         ubi->fm = fm;
1049         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1050         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1051         ubi_msg("attached by fastmap");
1052         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1053         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1054         ubi->fm_disabled = 0;
1055
1056         ubi_free_vid_hdr(ubi, vh);
1057         kfree(ech);
1058 out:
1059         mutex_unlock(&ubi->fm_mutex);
1060         if (ret == UBI_BAD_FASTMAP)
1061                 ubi_err("Attach by fastmap failed, doing a full scan!");
1062         return ret;
1063
1064 free_hdr:
1065         ubi_free_vid_hdr(ubi, vh);
1066         kfree(ech);
1067 free_fm_sb:
1068         kfree(fmsb);
1069         kfree(fm);
1070         goto out;
1071 }
1072
1073 /**
1074  * ubi_write_fastmap - writes a fastmap.
1075  * @ubi: UBI device object
1076  * @new_fm: the to be written fastmap
1077  *
1078  * Returns 0 on success, < 0 indicates an internal error.
1079  */
1080 static int ubi_write_fastmap(struct ubi_device *ubi,
1081                              struct ubi_fastmap_layout *new_fm)
1082 {
1083         size_t fm_pos = 0;
1084         void *fm_raw;
1085         struct ubi_fm_sb *fmsb;
1086         struct ubi_fm_hdr *fmh;
1087         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1088         struct ubi_fm_ec *fec;
1089         struct ubi_fm_volhdr *fvh;
1090         struct ubi_fm_eba *feba;
1091         struct rb_node *node;
1092         struct ubi_wl_entry *wl_e;
1093         struct ubi_volume *vol;
1094         struct ubi_vid_hdr *avhdr, *dvhdr;
1095         struct ubi_work *ubi_wrk;
1096         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1097         int scrub_peb_count, erase_peb_count;
1098
1099         fm_raw = ubi->fm_buf;
1100         memset(ubi->fm_buf, 0, ubi->fm_size);
1101
1102         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1103         if (!avhdr) {
1104                 ret = -ENOMEM;
1105                 goto out;
1106         }
1107
1108         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1109         if (!dvhdr) {
1110                 ret = -ENOMEM;
1111                 goto out_kfree;
1112         }
1113
1114         spin_lock(&ubi->volumes_lock);
1115         spin_lock(&ubi->wl_lock);
1116
1117         fmsb = (struct ubi_fm_sb *)fm_raw;
1118         fm_pos += sizeof(*fmsb);
1119         ubi_assert(fm_pos <= ubi->fm_size);
1120
1121         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1122         fm_pos += sizeof(*fmh);
1123         ubi_assert(fm_pos <= ubi->fm_size);
1124
1125         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1126         fmsb->version = UBI_FM_FMT_VERSION;
1127         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1128         /* the max sqnum will be filled in while *reading* the fastmap */
1129         fmsb->sqnum = 0;
1130
1131         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1132         free_peb_count = 0;
1133         used_peb_count = 0;
1134         scrub_peb_count = 0;
1135         erase_peb_count = 0;
1136         vol_count = 0;
1137
1138         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1139         fm_pos += sizeof(*fmpl1);
1140         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1141         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1142         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1143
1144         for (i = 0; i < ubi->fm_pool.size; i++)
1145                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1146
1147         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1148         fm_pos += sizeof(*fmpl2);
1149         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1150         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1151         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1152
1153         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1154                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1155
1156         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1157                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1158                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1159
1160                 fec->pnum = cpu_to_be32(wl_e->pnum);
1161                 fec->ec = cpu_to_be32(wl_e->ec);
1162
1163                 free_peb_count++;
1164                 fm_pos += sizeof(*fec);
1165                 ubi_assert(fm_pos <= ubi->fm_size);
1166         }
1167         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1168
1169         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1170                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1171                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1172
1173                 fec->pnum = cpu_to_be32(wl_e->pnum);
1174                 fec->ec = cpu_to_be32(wl_e->ec);
1175
1176                 used_peb_count++;
1177                 fm_pos += sizeof(*fec);
1178                 ubi_assert(fm_pos <= ubi->fm_size);
1179         }
1180         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1181
1182         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1183                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1184                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1185
1186                 fec->pnum = cpu_to_be32(wl_e->pnum);
1187                 fec->ec = cpu_to_be32(wl_e->ec);
1188
1189                 scrub_peb_count++;
1190                 fm_pos += sizeof(*fec);
1191                 ubi_assert(fm_pos <= ubi->fm_size);
1192         }
1193         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1194
1195
1196         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1197                 if (ubi_is_erase_work(ubi_wrk)) {
1198                         wl_e = ubi_wrk->e;
1199                         ubi_assert(wl_e);
1200
1201                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1202
1203                         fec->pnum = cpu_to_be32(wl_e->pnum);
1204                         fec->ec = cpu_to_be32(wl_e->ec);
1205
1206                         erase_peb_count++;
1207                         fm_pos += sizeof(*fec);
1208                         ubi_assert(fm_pos <= ubi->fm_size);
1209                 }
1210         }
1211         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1212
1213         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1214                 vol = ubi->volumes[i];
1215
1216                 if (!vol)
1217                         continue;
1218
1219                 vol_count++;
1220
1221                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1222                 fm_pos += sizeof(*fvh);
1223                 ubi_assert(fm_pos <= ubi->fm_size);
1224
1225                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1226                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1227                 fvh->vol_type = vol->vol_type;
1228                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1229                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1230                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1231
1232                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1233                         vol->vol_type == UBI_STATIC_VOLUME);
1234
1235                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1236                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1237                 ubi_assert(fm_pos <= ubi->fm_size);
1238
1239                 for (j = 0; j < vol->reserved_pebs; j++)
1240                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1241
1242                 feba->reserved_pebs = cpu_to_be32(j);
1243                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1244         }
1245         fmh->vol_count = cpu_to_be32(vol_count);
1246         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1247
1248         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1249         avhdr->lnum = 0;
1250
1251         spin_unlock(&ubi->wl_lock);
1252         spin_unlock(&ubi->volumes_lock);
1253
1254         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1255         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1256         if (ret) {
1257                 ubi_err("unable to write vid_hdr to fastmap SB!");
1258                 goto out_kfree;
1259         }
1260
1261         for (i = 0; i < new_fm->used_blocks; i++) {
1262                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1263                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1264         }
1265
1266         fmsb->data_crc = 0;
1267         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1268                                            ubi->fm_size));
1269
1270         for (i = 1; i < new_fm->used_blocks; i++) {
1271                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1272                 dvhdr->lnum = cpu_to_be32(i);
1273                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1274                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1275                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1276                 if (ret) {
1277                         ubi_err("unable to write vid_hdr to PEB %i!",
1278                                 new_fm->e[i]->pnum);
1279                         goto out_kfree;
1280                 }
1281         }
1282
1283         for (i = 0; i < new_fm->used_blocks; i++) {
1284                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1285                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1286                 if (ret) {
1287                         ubi_err("unable to write fastmap to PEB %i!",
1288                                 new_fm->e[i]->pnum);
1289                         goto out_kfree;
1290                 }
1291         }
1292
1293         ubi_assert(new_fm);
1294         ubi->fm = new_fm;
1295
1296         dbg_bld("fastmap written!");
1297
1298 out_kfree:
1299         ubi_free_vid_hdr(ubi, avhdr);
1300         ubi_free_vid_hdr(ubi, dvhdr);
1301 out:
1302         return ret;
1303 }
1304
1305 /**
1306  * erase_block - Manually erase a PEB.
1307  * @ubi: UBI device object
1308  * @pnum: PEB to be erased
1309  *
1310  * Returns the new EC value on success, < 0 indicates an internal error.
1311  */
1312 static int erase_block(struct ubi_device *ubi, int pnum)
1313 {
1314         int ret;
1315         struct ubi_ec_hdr *ec_hdr;
1316         long long ec;
1317
1318         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1319         if (!ec_hdr)
1320                 return -ENOMEM;
1321
1322         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1323         if (ret < 0)
1324                 goto out;
1325         else if (ret && ret != UBI_IO_BITFLIPS) {
1326                 ret = -EINVAL;
1327                 goto out;
1328         }
1329
1330         ret = ubi_io_sync_erase(ubi, pnum, 0);
1331         if (ret < 0)
1332                 goto out;
1333
1334         ec = be64_to_cpu(ec_hdr->ec);
1335         ec += ret;
1336         if (ec > UBI_MAX_ERASECOUNTER) {
1337                 ret = -EINVAL;
1338                 goto out;
1339         }
1340
1341         ec_hdr->ec = cpu_to_be64(ec);
1342         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1343         if (ret < 0)
1344                 goto out;
1345
1346         ret = ec;
1347 out:
1348         kfree(ec_hdr);
1349         return ret;
1350 }
1351
1352 /**
1353  * invalidate_fastmap - destroys a fastmap.
1354  * @ubi: UBI device object
1355  * @fm: the fastmap to be destroyed
1356  *
1357  * Returns 0 on success, < 0 indicates an internal error.
1358  */
1359 static int invalidate_fastmap(struct ubi_device *ubi,
1360                               struct ubi_fastmap_layout *fm)
1361 {
1362         int ret;
1363         struct ubi_vid_hdr *vh;
1364
1365         ret = erase_block(ubi, fm->e[0]->pnum);
1366         if (ret < 0)
1367                 return ret;
1368
1369         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1370         if (!vh)
1371                 return -ENOMEM;
1372
1373         /* deleting the current fastmap SB is not enough, an old SB may exist,
1374          * so create a (corrupted) SB such that fastmap will find it and fall
1375          * back to scanning mode in any case */
1376         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1377         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1378
1379         return ret;
1380 }
1381
1382 /**
1383  * ubi_update_fastmap - will be called by UBI if a volume changes or
1384  * a fastmap pool becomes full.
1385  * @ubi: UBI device object
1386  *
1387  * Returns 0 on success, < 0 indicates an internal error.
1388  */
1389 int ubi_update_fastmap(struct ubi_device *ubi)
1390 {
1391         int ret, i;
1392         struct ubi_fastmap_layout *new_fm, *old_fm;
1393         struct ubi_wl_entry *tmp_e;
1394
1395         mutex_lock(&ubi->fm_mutex);
1396
1397         ubi_refill_pools(ubi);
1398
1399         if (ubi->ro_mode || ubi->fm_disabled) {
1400                 mutex_unlock(&ubi->fm_mutex);
1401                 return 0;
1402         }
1403
1404         ret = ubi_ensure_anchor_pebs(ubi);
1405         if (ret) {
1406                 mutex_unlock(&ubi->fm_mutex);
1407                 return ret;
1408         }
1409
1410         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1411         if (!new_fm) {
1412                 mutex_unlock(&ubi->fm_mutex);
1413                 return -ENOMEM;
1414         }
1415
1416         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1417
1418         for (i = 0; i < new_fm->used_blocks; i++) {
1419                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1420                 if (!new_fm->e[i]) {
1421                         while (i--)
1422                                 kfree(new_fm->e[i]);
1423
1424                         kfree(new_fm);
1425                         mutex_unlock(&ubi->fm_mutex);
1426                         return -ENOMEM;
1427                 }
1428         }
1429
1430         old_fm = ubi->fm;
1431         ubi->fm = NULL;
1432
1433         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1434                 ubi_err("fastmap too large");
1435                 ret = -ENOSPC;
1436                 goto err;
1437         }
1438
1439         for (i = 1; i < new_fm->used_blocks; i++) {
1440                 spin_lock(&ubi->wl_lock);
1441                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1442                 spin_unlock(&ubi->wl_lock);
1443
1444                 if (!tmp_e && !old_fm) {
1445                         int j;
1446                         ubi_err("could not get any free erase block");
1447
1448                         for (j = 1; j < i; j++)
1449                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1450
1451                         ret = -ENOSPC;
1452                         goto err;
1453                 } else if (!tmp_e && old_fm) {
1454                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1455                         if (ret < 0) {
1456                                 int j;
1457
1458                                 for (j = 1; j < i; j++)
1459                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1460                                                           j, 0);
1461
1462                                 ubi_err("could not erase old fastmap PEB");
1463                                 goto err;
1464                         }
1465
1466                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1467                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1468                 } else {
1469                         new_fm->e[i]->pnum = tmp_e->pnum;
1470                         new_fm->e[i]->ec = tmp_e->ec;
1471
1472                         if (old_fm)
1473                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1474                                                   old_fm->to_be_tortured[i]);
1475                 }
1476         }
1477
1478         spin_lock(&ubi->wl_lock);
1479         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1480         spin_unlock(&ubi->wl_lock);
1481
1482         if (old_fm) {
1483                 /* no fresh anchor PEB was found, reuse the old one */
1484                 if (!tmp_e) {
1485                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1486                         if (ret < 0) {
1487                                 int i;
1488                                 ubi_err("could not erase old anchor PEB");
1489
1490                                 for (i = 1; i < new_fm->used_blocks; i++)
1491                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1492                                                           i, 0);
1493                                 goto err;
1494                         }
1495
1496                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1497                         new_fm->e[0]->ec = ret;
1498                 } else {
1499                         /* we've got a new anchor PEB, return the old one */
1500                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1501                                           old_fm->to_be_tortured[0]);
1502
1503                         new_fm->e[0]->pnum = tmp_e->pnum;
1504                         new_fm->e[0]->ec = tmp_e->ec;
1505                 }
1506         } else {
1507                 if (!tmp_e) {
1508                         int i;
1509                         ubi_err("could not find any anchor PEB");
1510
1511                         for (i = 1; i < new_fm->used_blocks; i++)
1512                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1513
1514                         ret = -ENOSPC;
1515                         goto err;
1516                 }
1517
1518                 new_fm->e[0]->pnum = tmp_e->pnum;
1519                 new_fm->e[0]->ec = tmp_e->ec;
1520         }
1521
1522         down_write(&ubi->work_sem);
1523         down_write(&ubi->fm_sem);
1524         ret = ubi_write_fastmap(ubi, new_fm);
1525         up_write(&ubi->fm_sem);
1526         up_write(&ubi->work_sem);
1527
1528         if (ret)
1529                 goto err;
1530
1531 out_unlock:
1532         mutex_unlock(&ubi->fm_mutex);
1533         kfree(old_fm);
1534         return ret;
1535
1536 err:
1537         kfree(new_fm);
1538
1539         ubi_warn("Unable to write new fastmap, err=%i", ret);
1540
1541         ret = 0;
1542         if (old_fm) {
1543                 ret = invalidate_fastmap(ubi, old_fm);
1544                 if (ret < 0)
1545                         ubi_err("Unable to invalidiate current fastmap!");
1546                 else if (ret)
1547                         ret = 0;
1548         }
1549         goto out_unlock;
1550 }