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
 411                 pnum = be32_to_cpu(pebs[i]);
 412
 413                 if (ubi_io_is_bad(ubi, pnum)) {
 414                         ubi_err("bad PEB in fastmap pool!");
 415                         ret = UBI_BAD_FASTMAP;
 416                         goto out;
 417                 }
 418
 419                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 420                 if (err && err != UBI_IO_BITFLIPS) {
 421                         ubi_err("unable to read EC header! PEB:%i err:%i",
 422                                 pnum, err);
 423                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 424                         goto out;
 425                 } else if (ret == UBI_IO_BITFLIPS)
 426                         scrub = 1;
 427
 428                 if (be32_to_cpu(ech->image_seq) != ubi->image_seq) {
 429                         ubi_err("bad image seq: 0x%x, expected: 0x%x",
 430                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 431                         err = UBI_BAD_FASTMAP;
 432                         goto out;
 433                 }
 434
 435                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 436                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 437                         unsigned long long ec = be64_to_cpu(ech->ec);
 438                         unmap_peb(ai, pnum);
 439                         dbg_bld("Adding PEB to free: %i", pnum);
 440                         if (err == UBI_IO_FF_BITFLIPS)
 441                                 add_aeb(ai, free, pnum, ec, 1);
 442                         else
 443                                 add_aeb(ai, free, pnum, ec, 0);
 444                         continue;
 445                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 446                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 447
 448                         if (err == UBI_IO_BITFLIPS)
 449                                 scrub = 1;
 450
 451                         found_orphan = 0;
 452                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
 453                                 if (tmp_aeb->pnum == pnum) {
 454                                         found_orphan = 1;
 455                                         break;
 456                                 }
 457                         }
 458                         if (found_orphan) {
 459                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 460                                 list_del(&tmp_aeb->u.list);
 461                         }
 462
 463                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 464                                                    GFP_KERNEL);
 465                         if (!new_aeb) {
 466                                 ret = -ENOMEM;
 467                                 goto out;
 468                         }
 469
 470                         new_aeb->ec = be64_to_cpu(ech->ec);
 471                         new_aeb->pnum = pnum;
 472                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 473                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 474                         new_aeb->copy_flag = vh->copy_flag;
 475                         new_aeb->scrub = scrub;
 476
 477                         if (*max_sqnum < new_aeb->sqnum)
 478                                 *max_sqnum = new_aeb->sqnum;
 479
 480                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 481                         if (err) {
 482                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 483                                 goto out;
 484                         }
 485                 } else {
 486                         /* We are paranoid and fall back to scanning mode */
 487                         ubi_err("fastmap pool PEBs contains damaged PEBs!");
 488                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 489                         goto out;
 490                 }
 491
 492         }
 493
 494 out:
 495         ubi_free_vid_hdr(ubi, vh);
 496         kfree(ech);
 497         return ret;
 498 }
 499
 500 /**
 501  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 502  * @ai: The UBI attach info object
 503  */
 504 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 505 {
 506         struct ubi_ainf_peb *aeb;
 507         struct ubi_ainf_volume *av;
 508         struct rb_node *rb1, *rb2;
 509         int n = 0;
 510
 511         list_for_each_entry(aeb, &ai->erase, u.list)
 512                 n++;
 513
 514         list_for_each_entry(aeb, &ai->free, u.list)
 515                 n++;
 516
 517          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 518                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 519                         n++;
 520
 521         return n;
 522 }
 523
 524 /**
 525  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 526  * @ubi: UBI device object
 527  * @ai: UBI attach info object
 528  * @fm: the fastmap to be attached
 529  *
 530  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 531  * < 0 indicates an internal error.
 532  */
 533 static int ubi_attach_fastmap(struct ubi_device *ubi,
 534                               struct ubi_attach_info *ai,
 535                               struct ubi_fastmap_layout *fm)
 536 {
 537         struct list_head used, eba_orphans, free;
 538         struct ubi_ainf_volume *av;
 539         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 540         struct ubi_ec_hdr *ech;
 541         struct ubi_fm_sb *fmsb;
 542         struct ubi_fm_hdr *fmhdr;
 543         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 544         struct ubi_fm_ec *fmec;
 545         struct ubi_fm_volhdr *fmvhdr;
 546         struct ubi_fm_eba *fm_eba;
 547         int ret, i, j, pool_size, wl_pool_size;
 548         size_t fm_pos = 0, fm_size = ubi->fm_size;
 549         unsigned long long max_sqnum = 0;
 550         void *fm_raw = ubi->fm_buf;
 551
 552         INIT_LIST_HEAD(&used);
 553         INIT_LIST_HEAD(&free);
 554         INIT_LIST_HEAD(&eba_orphans);
 555         INIT_LIST_HEAD(&ai->corr);
 556         INIT_LIST_HEAD(&ai->free);
 557         INIT_LIST_HEAD(&ai->erase);
 558         INIT_LIST_HEAD(&ai->alien);
 559         ai->volumes = RB_ROOT;
 560         ai->min_ec = UBI_MAX_ERASECOUNTER;
 561
 562         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
 563                                                sizeof(struct ubi_ainf_peb),
 564                                                0, 0, NULL);
 565         if (!ai->aeb_slab_cache) {
 566                 ret = -ENOMEM;
 567                 goto fail;
 568         }
 569
 570         fmsb = (struct ubi_fm_sb *)(fm_raw);
 571         ai->max_sqnum = fmsb->sqnum;
 572         fm_pos += sizeof(struct ubi_fm_sb);
 573         if (fm_pos >= fm_size)
 574                 goto fail_bad;
 575
 576         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 577         fm_pos += sizeof(*fmhdr);
 578         if (fm_pos >= fm_size)
 579                 goto fail_bad;
 580
 581         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 582                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
 583                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 584                 goto fail_bad;
 585         }
 586
 587         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 588         fm_pos += sizeof(*fmpl1);
 589         if (fm_pos >= fm_size)
 590                 goto fail_bad;
 591         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 592                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 593                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 594                 goto fail_bad;
 595         }
 596
 597         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 598         fm_pos += sizeof(*fmpl2);
 599         if (fm_pos >= fm_size)
 600                 goto fail_bad;
 601         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 602                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 603                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 604                 goto fail_bad;
 605         }
 606
 607         pool_size = be16_to_cpu(fmpl1->size);
 608         wl_pool_size = be16_to_cpu(fmpl2->size);
 609         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 610         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 611
 612         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 613                 ubi_err("bad pool size: %i", pool_size);
 614                 goto fail_bad;
 615         }
 616
 617         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 618                 ubi_err("bad WL pool size: %i", wl_pool_size);
 619                 goto fail_bad;
 620         }
 621
 622
 623         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 624             fm->max_pool_size < 0) {
 625                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
 626                 goto fail_bad;
 627         }
 628
 629         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 630             fm->max_wl_pool_size < 0) {
 631                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
 632                 goto fail_bad;
 633         }
 634
 635         /* read EC values from free list */
 636         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 637                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 638                 fm_pos += sizeof(*fmec);
 639                 if (fm_pos >= fm_size)
 640                         goto fail_bad;
 641
 642                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 643                         be32_to_cpu(fmec->ec), 0);
 644         }
 645
 646         /* read EC values from used list */
 647         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 648                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 649                 fm_pos += sizeof(*fmec);
 650                 if (fm_pos >= fm_size)
 651                         goto fail_bad;
 652
 653                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 654                         be32_to_cpu(fmec->ec), 0);
 655         }
 656
 657         /* read EC values from scrub list */
 658         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 659                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 660                 fm_pos += sizeof(*fmec);
 661                 if (fm_pos >= fm_size)
 662                         goto fail_bad;
 663
 664                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 665                         be32_to_cpu(fmec->ec), 1);
 666         }
 667
 668         /* read EC values from erase list */
 669         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 670                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 671                 fm_pos += sizeof(*fmec);
 672                 if (fm_pos >= fm_size)
 673                         goto fail_bad;
 674
 675                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 676                         be32_to_cpu(fmec->ec), 1);
 677         }
 678
 679         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 680         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 681
 682         /* Iterate over all volumes and read their EBA table */
 683         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 684                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 685                 fm_pos += sizeof(*fmvhdr);
 686                 if (fm_pos >= fm_size)
 687                         goto fail_bad;
 688
 689                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 690                         ubi_err("bad fastmap vol header magic: 0x%x, " \
 691                                 "expected: 0x%x",
 692                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 693                         goto fail_bad;
 694                 }
 695
 696                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 697                              be32_to_cpu(fmvhdr->used_ebs),
 698                              be32_to_cpu(fmvhdr->data_pad),
 699                              fmvhdr->vol_type,
 700                              be32_to_cpu(fmvhdr->last_eb_bytes));
 701
 702                 if (!av)
 703                         goto fail_bad;
 704
 705                 ai->vols_found++;
 706                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 707                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 708
 709                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 710                 fm_pos += sizeof(*fm_eba);
 711                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 712                 if (fm_pos >= fm_size)
 713                         goto fail_bad;
 714
 715                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 716                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
 717                                 "expected: 0x%x",
 718                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 719                         goto fail_bad;
 720                 }
 721
 722                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 723                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 724
 725                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 726                                 continue;
 727
 728                         aeb = NULL;
 729                         list_for_each_entry(tmp_aeb, &used, u.list) {
 730                                 if (tmp_aeb->pnum == pnum) {
 731                                         aeb = tmp_aeb;
 732                                         break;
 733                                 }
 734                         }
 735
 736                         /* This can happen if a PEB is already in an EBA known
 737                          * by this fastmap but the PEB itself is not in the used
 738                          * list.
 739                          * In this case the PEB can be within the fastmap pool
 740                          * or while writing the fastmap it was in the protection
 741                          * queue.
 742                          */
 743                         if (!aeb) {
 744                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 745                                                        GFP_KERNEL);
 746                                 if (!aeb) {
 747                                         ret = -ENOMEM;
 748
 749                                         goto fail;
 750                                 }
 751
 752                                 aeb->lnum = j;
 753                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 754                                 aeb->ec = -1;
 755                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 756                                 list_add_tail(&aeb->u.list, &eba_orphans);
 757                                 continue;
 758                         }
 759
 760                         aeb->lnum = j;
 761
 762                         if (av->highest_lnum <= aeb->lnum)
 763                                 av->highest_lnum = aeb->lnum;
 764
 765                         assign_aeb_to_av(ai, aeb, av);
 766
 767                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 768                                 aeb->pnum, aeb->lnum, av->vol_id);
 769                 }
 770
 771                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 772                 if (!ech) {
 773                         ret = -ENOMEM;
 774                         goto fail;
 775                 }
 776
 777                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 778                                          u.list) {
 779                         int err;
 780
 781                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 782                                 ubi_err("bad PEB in fastmap EBA orphan list");
 783                                 ret = UBI_BAD_FASTMAP;
 784                                 kfree(ech);
 785                                 goto fail;
 786                         }
 787
 788                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 789                         if (err && err != UBI_IO_BITFLIPS) {
 790                                 ubi_err("unable to read EC header! PEB:%i " \
 791                                         "err:%i", tmp_aeb->pnum, err);
 792                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 793                                 kfree(ech);
 794
 795                                 goto fail;
 796                         } else if (err == UBI_IO_BITFLIPS)
 797                                 tmp_aeb->scrub = 1;
 798
 799                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 800                         assign_aeb_to_av(ai, tmp_aeb, av);
 801                 }
 802
 803                 kfree(ech);
 804         }
 805
 806         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 807                         &eba_orphans, &free);
 808         if (ret)
 809                 goto fail;
 810
 811         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 812                         &eba_orphans, &free);
 813         if (ret)
 814                 goto fail;
 815
 816         if (max_sqnum > ai->max_sqnum)
 817                 ai->max_sqnum = max_sqnum;
 818
 819         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 820                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 821
 822         /*
 823          * If fastmap is leaking PEBs (must not happen), raise a
 824          * fat warning and fall back to scanning mode.
 825          * We do this here because in ubi_wl_init() it's too late
 826          * and we cannot fall back to scanning.
 827          */
 828         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 829                     ai->bad_peb_count - fm->used_blocks))
 830                 goto fail_bad;
 831
 832         return 0;
 833
 834 fail_bad:
 835         ret = UBI_BAD_FASTMAP;
 836 fail:
 837         return ret;
 838 }
 839
 840 /**
 841  * ubi_scan_fastmap - scan the fastmap.
 842  * @ubi: UBI device object
 843  * @ai: UBI attach info to be filled
 844  * @fm_anchor: The fastmap starts at this PEB
 845  *
 846  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 847  * UBI_BAD_FASTMAP if one was found but is not usable.
 848  * < 0 indicates an internal error.
 849  */
 850 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 851                      int fm_anchor)
 852 {
 853         struct ubi_fm_sb *fmsb, *fmsb2;
 854         struct ubi_vid_hdr *vh;
 855         struct ubi_ec_hdr *ech;
 856         struct ubi_fastmap_layout *fm;
 857         int i, used_blocks, pnum, ret = 0;
 858         size_t fm_size;
 859         __be32 crc, tmp_crc;
 860         unsigned long long sqnum = 0;
 861
 862         mutex_lock(&ubi->fm_mutex);
 863         memset(ubi->fm_buf, 0, ubi->fm_size);
 864
 865         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 866         if (!fmsb) {
 867                 ret = -ENOMEM;
 868                 goto out;
 869         }
 870
 871         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 872         if (!fm) {
 873                 ret = -ENOMEM;
 874                 kfree(fmsb);
 875                 goto out;
 876         }
 877
 878         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 879         if (ret && ret != UBI_IO_BITFLIPS)
 880                 goto free_fm_sb;
 881         else if (ret == UBI_IO_BITFLIPS)
 882                 fm->to_be_tortured[0] = 1;
 883
 884         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 885                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
 886                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 887                 ret = UBI_BAD_FASTMAP;
 888                 goto free_fm_sb;
 889         }
 890
 891         if (fmsb->version != UBI_FM_FMT_VERSION) {
 892                 ubi_err("bad fastmap version: %i, expected: %i",
 893                         fmsb->version, UBI_FM_FMT_VERSION);
 894                 ret = UBI_BAD_FASTMAP;
 895                 goto free_fm_sb;
 896         }
 897
 898         used_blocks = be32_to_cpu(fmsb->used_blocks);
 899         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 900                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
 901                 ret = UBI_BAD_FASTMAP;
 902                 goto free_fm_sb;
 903         }
 904
 905         fm_size = ubi->leb_size * used_blocks;
 906         if (fm_size != ubi->fm_size) {
 907                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
 908                         ubi->fm_size);
 909                 ret = UBI_BAD_FASTMAP;
 910                 goto free_fm_sb;
 911         }
 912
 913         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 914         if (!ech) {
 915                 ret = -ENOMEM;
 916                 goto free_fm_sb;
 917         }
 918
 919         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 920         if (!vh) {
 921                 ret = -ENOMEM;
 922                 goto free_hdr;
 923         }
 924
 925         for (i = 0; i < used_blocks; i++) {
 926                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 927
 928                 if (ubi_io_is_bad(ubi, pnum)) {
 929                         ret = UBI_BAD_FASTMAP;
 930                         goto free_hdr;
 931                 }
 932
 933                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 934                 if (ret && ret != UBI_IO_BITFLIPS) {
 935                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
 936                                 i, pnum);
 937                         if (ret > 0)
 938                                 ret = UBI_BAD_FASTMAP;
 939                         goto free_hdr;
 940                 } else if (ret == UBI_IO_BITFLIPS)
 941                         fm->to_be_tortured[i] = 1;
 942
 943                 if (!ubi->image_seq)
 944                         ubi->image_seq = be32_to_cpu(ech->image_seq);
 945
 946                 if (be32_to_cpu(ech->image_seq) != ubi->image_seq) {
 947                         ret = UBI_BAD_FASTMAP;
 948                         goto free_hdr;
 949                 }
 950
 951                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 952                 if (ret && ret != UBI_IO_BITFLIPS) {
 953                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
 954                                 i, pnum);
 955                         goto free_hdr;
 956                 }
 957
 958                 if (i == 0) {
 959                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 960                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
 961                                         " expected: 0x%x",
 962                                         be32_to_cpu(vh->vol_id),
 963                                         UBI_FM_SB_VOLUME_ID);
 964                                 ret = UBI_BAD_FASTMAP;
 965                                 goto free_hdr;
 966                         }
 967                 } else {
 968                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 969                                 ubi_err("bad fastmap data vol_id: 0x%x," \
 970                                         " expected: 0x%x",
 971                                         be32_to_cpu(vh->vol_id),
 972                                         UBI_FM_DATA_VOLUME_ID);
 973                                 ret = UBI_BAD_FASTMAP;
 974                                 goto free_hdr;
 975                         }
 976                 }
 977
 978                 if (sqnum < be64_to_cpu(vh->sqnum))
 979                         sqnum = be64_to_cpu(vh->sqnum);
 980
 981                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
 982                                   ubi->leb_start, ubi->leb_size);
 983                 if (ret && ret != UBI_IO_BITFLIPS) {
 984                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
 985                                 "err: %i)", i, pnum, ret);
 986                         goto free_hdr;
 987                 }
 988         }
 989
 990         kfree(fmsb);
 991         fmsb = NULL;
 992
 993         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
 994         tmp_crc = be32_to_cpu(fmsb2->data_crc);
 995         fmsb2->data_crc = 0;
 996         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
 997         if (crc != tmp_crc) {
 998                 ubi_err("fastmap data CRC is invalid");
 999                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1000                 ret = UBI_BAD_FASTMAP;
1001                 goto free_hdr;
1002         }
1003
1004         fmsb2->sqnum = sqnum;
1005
1006         fm->used_blocks = used_blocks;
1007
1008         ret = ubi_attach_fastmap(ubi, ai, fm);
1009         if (ret) {
1010                 if (ret > 0)
1011                         ret = UBI_BAD_FASTMAP;
1012                 goto free_hdr;
1013         }
1014
1015         for (i = 0; i < used_blocks; i++) {
1016                 struct ubi_wl_entry *e;
1017
1018                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1019                 if (!e) {
1020                         while (i--)
1021                                 kfree(fm->e[i]);
1022
1023                         ret = -ENOMEM;
1024                         goto free_hdr;
1025                 }
1026
1027                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1028                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1029                 fm->e[i] = e;
1030         }
1031
1032         ubi->fm = fm;
1033         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1034         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1035         ubi_msg("attached by fastmap");
1036         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1037         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1038         ubi->fm_disabled = 0;
1039
1040         ubi_free_vid_hdr(ubi, vh);
1041         kfree(ech);
1042 out:
1043         mutex_unlock(&ubi->fm_mutex);
1044         if (ret == UBI_BAD_FASTMAP)
1045                 ubi_err("Attach by fastmap failed, doing a full scan!");
1046         return ret;
1047
1048 free_hdr:
1049         ubi_free_vid_hdr(ubi, vh);
1050         kfree(ech);
1051 free_fm_sb:
1052         kfree(fmsb);
1053         kfree(fm);
1054         goto out;
1055 }
1056
1057 /**
1058  * ubi_write_fastmap - writes a fastmap.
1059  * @ubi: UBI device object
1060  * @new_fm: the to be written fastmap
1061  *
1062  * Returns 0 on success, < 0 indicates an internal error.
1063  */
1064 static int ubi_write_fastmap(struct ubi_device *ubi,
1065                              struct ubi_fastmap_layout *new_fm)
1066 {
1067         size_t fm_pos = 0;
1068         void *fm_raw;
1069         struct ubi_fm_sb *fmsb;
1070         struct ubi_fm_hdr *fmh;
1071         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1072         struct ubi_fm_ec *fec;
1073         struct ubi_fm_volhdr *fvh;
1074         struct ubi_fm_eba *feba;
1075         struct rb_node *node;
1076         struct ubi_wl_entry *wl_e;
1077         struct ubi_volume *vol;
1078         struct ubi_vid_hdr *avhdr, *dvhdr;
1079         struct ubi_work *ubi_wrk;
1080         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1081         int scrub_peb_count, erase_peb_count;
1082
1083         fm_raw = ubi->fm_buf;
1084         memset(ubi->fm_buf, 0, ubi->fm_size);
1085
1086         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1087         if (!avhdr) {
1088                 ret = -ENOMEM;
1089                 goto out;
1090         }
1091
1092         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1093         if (!dvhdr) {
1094                 ret = -ENOMEM;
1095                 goto out_kfree;
1096         }
1097
1098         spin_lock(&ubi->volumes_lock);
1099         spin_lock(&ubi->wl_lock);
1100
1101         fmsb = (struct ubi_fm_sb *)fm_raw;
1102         fm_pos += sizeof(*fmsb);
1103         ubi_assert(fm_pos <= ubi->fm_size);
1104
1105         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1106         fm_pos += sizeof(*fmh);
1107         ubi_assert(fm_pos <= ubi->fm_size);
1108
1109         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1110         fmsb->version = UBI_FM_FMT_VERSION;
1111         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1112         /* the max sqnum will be filled in while *reading* the fastmap */
1113         fmsb->sqnum = 0;
1114
1115         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1116         free_peb_count = 0;
1117         used_peb_count = 0;
1118         scrub_peb_count = 0;
1119         erase_peb_count = 0;
1120         vol_count = 0;
1121
1122         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1123         fm_pos += sizeof(*fmpl1);
1124         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1125         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1126         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1127
1128         for (i = 0; i < ubi->fm_pool.size; i++)
1129                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1130
1131         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1132         fm_pos += sizeof(*fmpl2);
1133         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1134         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1135         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1136
1137         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1138                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1139
1140         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1141                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1142                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1143
1144                 fec->pnum = cpu_to_be32(wl_e->pnum);
1145                 fec->ec = cpu_to_be32(wl_e->ec);
1146
1147                 free_peb_count++;
1148                 fm_pos += sizeof(*fec);
1149                 ubi_assert(fm_pos <= ubi->fm_size);
1150         }
1151         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1152
1153         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1154                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1155                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1156
1157                 fec->pnum = cpu_to_be32(wl_e->pnum);
1158                 fec->ec = cpu_to_be32(wl_e->ec);
1159
1160                 used_peb_count++;
1161                 fm_pos += sizeof(*fec);
1162                 ubi_assert(fm_pos <= ubi->fm_size);
1163         }
1164         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1165
1166         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1167                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1168                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1169
1170                 fec->pnum = cpu_to_be32(wl_e->pnum);
1171                 fec->ec = cpu_to_be32(wl_e->ec);
1172
1173                 scrub_peb_count++;
1174                 fm_pos += sizeof(*fec);
1175                 ubi_assert(fm_pos <= ubi->fm_size);
1176         }
1177         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1178
1179
1180         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1181                 if (ubi_is_erase_work(ubi_wrk)) {
1182                         wl_e = ubi_wrk->e;
1183                         ubi_assert(wl_e);
1184
1185                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1186
1187                         fec->pnum = cpu_to_be32(wl_e->pnum);
1188                         fec->ec = cpu_to_be32(wl_e->ec);
1189
1190                         erase_peb_count++;
1191                         fm_pos += sizeof(*fec);
1192                         ubi_assert(fm_pos <= ubi->fm_size);
1193                 }
1194         }
1195         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1196
1197         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1198                 vol = ubi->volumes[i];
1199
1200                 if (!vol)
1201                         continue;
1202
1203                 vol_count++;
1204
1205                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1206                 fm_pos += sizeof(*fvh);
1207                 ubi_assert(fm_pos <= ubi->fm_size);
1208
1209                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1210                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1211                 fvh->vol_type = vol->vol_type;
1212                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1213                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1214                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1215
1216                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1217                         vol->vol_type == UBI_STATIC_VOLUME);
1218
1219                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1220                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1221                 ubi_assert(fm_pos <= ubi->fm_size);
1222
1223                 for (j = 0; j < vol->reserved_pebs; j++)
1224                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1225
1226                 feba->reserved_pebs = cpu_to_be32(j);
1227                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1228         }
1229         fmh->vol_count = cpu_to_be32(vol_count);
1230         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1231
1232         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1233         avhdr->lnum = 0;
1234
1235         spin_unlock(&ubi->wl_lock);
1236         spin_unlock(&ubi->volumes_lock);
1237
1238         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1239         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1240         if (ret) {
1241                 ubi_err("unable to write vid_hdr to fastmap SB!");
1242                 goto out_kfree;
1243         }
1244
1245         for (i = 0; i < new_fm->used_blocks; i++) {
1246                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1247                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1248         }
1249
1250         fmsb->data_crc = 0;
1251         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1252                                            ubi->fm_size));
1253
1254         for (i = 1; i < new_fm->used_blocks; i++) {
1255                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1256                 dvhdr->lnum = cpu_to_be32(i);
1257                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1258                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1259                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1260                 if (ret) {
1261                         ubi_err("unable to write vid_hdr to PEB %i!",
1262                                 new_fm->e[i]->pnum);
1263                         goto out_kfree;
1264                 }
1265         }
1266
1267         for (i = 0; i < new_fm->used_blocks; i++) {
1268                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1269                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1270                 if (ret) {
1271                         ubi_err("unable to write fastmap to PEB %i!",
1272                                 new_fm->e[i]->pnum);
1273                         goto out_kfree;
1274                 }
1275         }
1276
1277         ubi_assert(new_fm);
1278         ubi->fm = new_fm;
1279
1280         dbg_bld("fastmap written!");
1281
1282 out_kfree:
1283         ubi_free_vid_hdr(ubi, avhdr);
1284         ubi_free_vid_hdr(ubi, dvhdr);
1285 out:
1286         return ret;
1287 }
1288
1289 /**
1290  * erase_block - Manually erase a PEB.
1291  * @ubi: UBI device object
1292  * @pnum: PEB to be erased
1293  *
1294  * Returns the new EC value on success, < 0 indicates an internal error.
1295  */
1296 static int erase_block(struct ubi_device *ubi, int pnum)
1297 {
1298         int ret;
1299         struct ubi_ec_hdr *ec_hdr;
1300         long long ec;
1301
1302         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1303         if (!ec_hdr)
1304                 return -ENOMEM;
1305
1306         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1307         if (ret < 0)
1308                 goto out;
1309         else if (ret && ret != UBI_IO_BITFLIPS) {
1310                 ret = -EINVAL;
1311                 goto out;
1312         }
1313
1314         ret = ubi_io_sync_erase(ubi, pnum, 0);
1315         if (ret < 0)
1316                 goto out;
1317
1318         ec = be64_to_cpu(ec_hdr->ec);
1319         ec += ret;
1320         if (ec > UBI_MAX_ERASECOUNTER) {
1321                 ret = -EINVAL;
1322                 goto out;
1323         }
1324
1325         ec_hdr->ec = cpu_to_be64(ec);
1326         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1327         if (ret < 0)
1328                 goto out;
1329
1330         ret = ec;
1331 out:
1332         kfree(ec_hdr);
1333         return ret;
1334 }
1335
1336 /**
1337  * invalidate_fastmap - destroys a fastmap.
1338  * @ubi: UBI device object
1339  * @fm: the fastmap to be destroyed
1340  *
1341  * Returns 0 on success, < 0 indicates an internal error.
1342  */
1343 static int invalidate_fastmap(struct ubi_device *ubi,
1344                               struct ubi_fastmap_layout *fm)
1345 {
1346         int ret;
1347         struct ubi_vid_hdr *vh;
1348
1349         ret = erase_block(ubi, fm->e[0]->pnum);
1350         if (ret < 0)
1351                 return ret;
1352
1353         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1354         if (!vh)
1355                 return -ENOMEM;
1356
1357         /* deleting the current fastmap SB is not enough, an old SB may exist,
1358          * so create a (corrupted) SB such that fastmap will find it and fall
1359          * back to scanning mode in any case */
1360         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1361         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1362
1363         return ret;
1364 }
1365
1366 /**
1367  * ubi_update_fastmap - will be called by UBI if a volume changes or
1368  * a fastmap pool becomes full.
1369  * @ubi: UBI device object
1370  *
1371  * Returns 0 on success, < 0 indicates an internal error.
1372  */
1373 int ubi_update_fastmap(struct ubi_device *ubi)
1374 {
1375         int ret, i;
1376         struct ubi_fastmap_layout *new_fm, *old_fm;
1377         struct ubi_wl_entry *tmp_e;
1378
1379         mutex_lock(&ubi->fm_mutex);
1380
1381         ubi_refill_pools(ubi);
1382
1383         if (ubi->ro_mode || ubi->fm_disabled) {
1384                 mutex_unlock(&ubi->fm_mutex);
1385                 return 0;
1386         }
1387
1388         ret = ubi_ensure_anchor_pebs(ubi);
1389         if (ret) {
1390                 mutex_unlock(&ubi->fm_mutex);
1391                 return ret;
1392         }
1393
1394         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1395         if (!new_fm) {
1396                 mutex_unlock(&ubi->fm_mutex);
1397                 return -ENOMEM;
1398         }
1399
1400         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1401
1402         for (i = 0; i < new_fm->used_blocks; i++) {
1403                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1404                 if (!new_fm->e[i]) {
1405                         while (i--)
1406                                 kfree(new_fm->e[i]);
1407
1408                         kfree(new_fm);
1409                         mutex_unlock(&ubi->fm_mutex);
1410                         return -ENOMEM;
1411                 }
1412         }
1413
1414         old_fm = ubi->fm;
1415         ubi->fm = NULL;
1416
1417         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1418                 ubi_err("fastmap too large");
1419                 ret = -ENOSPC;
1420                 goto err;
1421         }
1422
1423         for (i = 1; i < new_fm->used_blocks; i++) {
1424                 spin_lock(&ubi->wl_lock);
1425                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1426                 spin_unlock(&ubi->wl_lock);
1427
1428                 if (!tmp_e && !old_fm) {
1429                         int j;
1430                         ubi_err("could not get any free erase block");
1431
1432                         for (j = 1; j < i; j++)
1433                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1434
1435                         ret = -ENOSPC;
1436                         goto err;
1437                 } else if (!tmp_e && old_fm) {
1438                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1439                         if (ret < 0) {
1440                                 int j;
1441
1442                                 for (j = 1; j < i; j++)
1443                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1444                                                           j, 0);
1445
1446                                 ubi_err("could not erase old fastmap PEB");
1447                                 goto err;
1448                         }
1449
1450                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1451                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1452                 } else {
1453                         new_fm->e[i]->pnum = tmp_e->pnum;
1454                         new_fm->e[i]->ec = tmp_e->ec;
1455
1456                         if (old_fm)
1457                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1458                                                   old_fm->to_be_tortured[i]);
1459                 }
1460         }
1461
1462         spin_lock(&ubi->wl_lock);
1463         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1464         spin_unlock(&ubi->wl_lock);
1465
1466         if (old_fm) {
1467                 /* no fresh anchor PEB was found, reuse the old one */
1468                 if (!tmp_e) {
1469                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1470                         if (ret < 0) {
1471                                 int i;
1472                                 ubi_err("could not erase old anchor PEB");
1473
1474                                 for (i = 1; i < new_fm->used_blocks; i++)
1475                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1476                                                           i, 0);
1477                                 goto err;
1478                         }
1479
1480                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1481                         new_fm->e[0]->ec = ret;
1482                 } else {
1483                         /* we've got a new anchor PEB, return the old one */
1484                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1485                                           old_fm->to_be_tortured[0]);
1486
1487                         new_fm->e[0]->pnum = tmp_e->pnum;
1488                         new_fm->e[0]->ec = tmp_e->ec;
1489                 }
1490         } else {
1491                 if (!tmp_e) {
1492                         int i;
1493                         ubi_err("could not find any anchor PEB");
1494
1495                         for (i = 1; i < new_fm->used_blocks; i++)
1496                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1497
1498                         ret = -ENOSPC;
1499                         goto err;
1500                 }
1501
1502                 new_fm->e[0]->pnum = tmp_e->pnum;
1503                 new_fm->e[0]->ec = tmp_e->ec;
1504         }
1505
1506         down_write(&ubi->work_sem);
1507         down_write(&ubi->fm_sem);
1508         ret = ubi_write_fastmap(ubi, new_fm);
1509         up_write(&ubi->fm_sem);
1510         up_write(&ubi->work_sem);
1511
1512         if (ret)
1513                 goto err;
1514
1515 out_unlock:
1516         mutex_unlock(&ubi->fm_mutex);
1517         kfree(old_fm);
1518         return ret;
1519
1520 err:
1521         kfree(new_fm);
1522
1523         ubi_warn("Unable to write new fastmap, err=%i", ret);
1524
1525         ret = 0;
1526         if (old_fm) {
1527                 ret = invalidate_fastmap(ubi, old_fm);
1528                 if (ret < 0)
1529                         ubi_err("Unable to invalidiate current fastmap!");
1530                 else if (ret)
1531                         ret = 0;
1532         }
1533         goto out_unlock;
1534 }