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
 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                         aeb->sqnum = new_aeb->sqnum;
 262                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 263
 264                 /* new_aeb is older */
 265                 } else {
 266                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 267                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 268                         list_add_tail(&new_aeb->u.list, &ai->erase);
 269                 }
 270
 271                 return 0;
 272         }
 273         /* This LEB is new, let's add it to the volume */
 274
 275         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 276                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 277                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 278         }
 279
 280         if (av->vol_type == UBI_STATIC_VOLUME)
 281                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 282
 283         av->leb_count++;
 284
 285         rb_link_node(&new_aeb->u.rb, parent, p);
 286         rb_insert_color(&new_aeb->u.rb, &av->root);
 287
 288         return 0;
 289 }
 290
 291 /**
 292  * process_pool_aeb - we found a non-empty PEB in a pool.
 293  * @ubi: UBI device object
 294  * @ai: attach info object
 295  * @new_vh: the volume header derived from new_aeb
 296  * @new_aeb: the AEB to be examined
 297  *
 298  * Returns 0 on success, < 0 indicates an internal error.
 299  */
 300 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 301                             struct ubi_vid_hdr *new_vh,
 302                             struct ubi_ainf_peb *new_aeb)
 303 {
 304         struct ubi_ainf_volume *av, *tmp_av = NULL;
 305         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 306         int found = 0;
 307
 308         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 309                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 310                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 311
 312                 return 0;
 313         }
 314
 315         /* Find the volume this SEB belongs to */
 316         while (*p) {
 317                 parent = *p;
 318                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 319
 320                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 321                         p = &(*p)->rb_left;
 322                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 323                         p = &(*p)->rb_right;
 324                 else {
 325                         found = 1;
 326                         break;
 327                 }
 328         }
 329
 330         if (found)
 331                 av = tmp_av;
 332         else {
 333                 ubi_err("orphaned volume in fastmap pool!");
 334                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 335                 return UBI_BAD_FASTMAP;
 336         }
 337
 338         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 339
 340         return update_vol(ubi, ai, av, new_vh, new_aeb);
 341 }
 342
 343 /**
 344  * unmap_peb - unmap a PEB.
 345  * If fastmap detects a free PEB in the pool it has to check whether
 346  * this PEB has been unmapped after writing the fastmap.
 347  *
 348  * @ai: UBI attach info object
 349  * @pnum: The PEB to be unmapped
 350  */
 351 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 352 {
 353         struct ubi_ainf_volume *av;
 354         struct rb_node *node, *node2;
 355         struct ubi_ainf_peb *aeb;
 356
 357         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 358                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 359
 360                 for (node2 = rb_first(&av->root); node2;
 361                      node2 = rb_next(node2)) {
 362                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 363                         if (aeb->pnum == pnum) {
 364                                 rb_erase(&aeb->u.rb, &av->root);
 365                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 366                                 return;
 367                         }
 368                 }
 369         }
 370 }
 371
 372 /**
 373  * scan_pool - scans a pool for changed (no longer empty PEBs).
 374  * @ubi: UBI device object
 375  * @ai: attach info object
 376  * @pebs: an array of all PEB numbers in the to be scanned pool
 377  * @pool_size: size of the pool (number of entries in @pebs)
 378  * @max_sqnum: pointer to the maximal sequence number
 379  * @eba_orphans: list of PEBs which need to be scanned
 380  * @free: list of PEBs which are most likely free (and go into @ai->free)
 381  *
 382  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 383  * < 0 indicates an internal error.
 384  */
 385 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 386                      int *pebs, int pool_size, unsigned long long *max_sqnum,
 387                      struct list_head *eba_orphans, struct list_head *free)
 388 {
 389         struct ubi_vid_hdr *vh;
 390         struct ubi_ec_hdr *ech;
 391         struct ubi_ainf_peb *new_aeb, *tmp_aeb;
 392         int i, pnum, err, found_orphan, ret = 0;
 393
 394         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 395         if (!ech)
 396                 return -ENOMEM;
 397
 398         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 399         if (!vh) {
 400                 kfree(ech);
 401                 return -ENOMEM;
 402         }
 403
 404         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 405
 406         /*
 407          * Now scan all PEBs in the pool to find changes which have been made
 408          * after the creation of the fastmap
 409          */
 410         for (i = 0; i < pool_size; i++) {
 411                 int scrub = 0;
 412                 int image_seq;
 413
 414                 pnum = be32_to_cpu(pebs[i]);
 415
 416                 if (ubi_io_is_bad(ubi, pnum)) {
 417                         ubi_err("bad PEB in fastmap pool!");
 418                         ret = UBI_BAD_FASTMAP;
 419                         goto out;
 420                 }
 421
 422                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 423                 if (err && err != UBI_IO_BITFLIPS) {
 424                         ubi_err("unable to read EC header! PEB:%i err:%i",
 425                                 pnum, err);
 426                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 427                         goto out;
 428                 } else if (err == UBI_IO_BITFLIPS)
 429                         scrub = 1;
 430
 431                 /*
 432                  * Older UBI implementations have image_seq set to zero, so
 433                  * we shouldn't fail if image_seq == 0.
 434                  */
 435                 image_seq = be32_to_cpu(ech->image_seq);
 436
 437                 if (image_seq && (image_seq != ubi->image_seq)) {
 438                         ubi_err("bad image seq: 0x%x, expected: 0x%x",
 439                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 440                         ret = UBI_BAD_FASTMAP;
 441                         goto out;
 442                 }
 443
 444                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 445                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 446                         unsigned long long ec = be64_to_cpu(ech->ec);
 447                         unmap_peb(ai, pnum);
 448                         dbg_bld("Adding PEB to free: %i", pnum);
 449
 450                         if (err == UBI_IO_FF_BITFLIPS)
 451                                 scrub = 1;
 452
 453                         add_aeb(ai, free, pnum, ec, scrub);
 454                         continue;
 455                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 456                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 457
 458                         if (err == UBI_IO_BITFLIPS)
 459                                 scrub = 1;
 460
 461                         found_orphan = 0;
 462                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
 463                                 if (tmp_aeb->pnum == pnum) {
 464                                         found_orphan = 1;
 465                                         break;
 466                                 }
 467                         }
 468                         if (found_orphan) {
 469                                 list_del(&tmp_aeb->u.list);
 470                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 471                         }
 472
 473                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 474                                                    GFP_KERNEL);
 475                         if (!new_aeb) {
 476                                 ret = -ENOMEM;
 477                                 goto out;
 478                         }
 479
 480                         new_aeb->ec = be64_to_cpu(ech->ec);
 481                         new_aeb->pnum = pnum;
 482                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 483                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 484                         new_aeb->copy_flag = vh->copy_flag;
 485                         new_aeb->scrub = scrub;
 486
 487                         if (*max_sqnum < new_aeb->sqnum)
 488                                 *max_sqnum = new_aeb->sqnum;
 489
 490                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 491                         if (err) {
 492                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 493                                 goto out;
 494                         }
 495                 } else {
 496                         /* We are paranoid and fall back to scanning mode */
 497                         ubi_err("fastmap pool PEBs contains damaged PEBs!");
 498                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 499                         goto out;
 500                 }
 501
 502         }
 503
 504 out:
 505         ubi_free_vid_hdr(ubi, vh);
 506         kfree(ech);
 507         return ret;
 508 }
 509
 510 /**
 511  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 512  * @ai: The UBI attach info object
 513  */
 514 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 515 {
 516         struct ubi_ainf_peb *aeb;
 517         struct ubi_ainf_volume *av;
 518         struct rb_node *rb1, *rb2;
 519         int n = 0;
 520
 521         list_for_each_entry(aeb, &ai->erase, u.list)
 522                 n++;
 523
 524         list_for_each_entry(aeb, &ai->free, u.list)
 525                 n++;
 526
 527          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 528                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 529                         n++;
 530
 531         return n;
 532 }
 533
 534 /**
 535  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 536  * @ubi: UBI device object
 537  * @ai: UBI attach info object
 538  * @fm: the fastmap to be attached
 539  *
 540  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 541  * < 0 indicates an internal error.
 542  */
 543 static int ubi_attach_fastmap(struct ubi_device *ubi,
 544                               struct ubi_attach_info *ai,
 545                               struct ubi_fastmap_layout *fm)
 546 {
 547         struct list_head used, eba_orphans, free;
 548         struct ubi_ainf_volume *av;
 549         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 550         struct ubi_ec_hdr *ech;
 551         struct ubi_fm_sb *fmsb;
 552         struct ubi_fm_hdr *fmhdr;
 553         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 554         struct ubi_fm_ec *fmec;
 555         struct ubi_fm_volhdr *fmvhdr;
 556         struct ubi_fm_eba *fm_eba;
 557         int ret, i, j, pool_size, wl_pool_size;
 558         size_t fm_pos = 0, fm_size = ubi->fm_size;
 559         unsigned long long max_sqnum = 0;
 560         void *fm_raw = ubi->fm_buf;
 561
 562         INIT_LIST_HEAD(&used);
 563         INIT_LIST_HEAD(&free);
 564         INIT_LIST_HEAD(&eba_orphans);
 565         INIT_LIST_HEAD(&ai->corr);
 566         INIT_LIST_HEAD(&ai->free);
 567         INIT_LIST_HEAD(&ai->erase);
 568         INIT_LIST_HEAD(&ai->alien);
 569         ai->volumes = RB_ROOT;
 570         ai->min_ec = UBI_MAX_ERASECOUNTER;
 571
 572         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
 573                                                sizeof(struct ubi_ainf_peb),
 574                                                0, 0, NULL);
 575         if (!ai->aeb_slab_cache) {
 576                 ret = -ENOMEM;
 577                 goto fail;
 578         }
 579
 580         fmsb = (struct ubi_fm_sb *)(fm_raw);
 581         ai->max_sqnum = fmsb->sqnum;
 582         fm_pos += sizeof(struct ubi_fm_sb);
 583         if (fm_pos >= fm_size)
 584                 goto fail_bad;
 585
 586         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 587         fm_pos += sizeof(*fmhdr);
 588         if (fm_pos >= fm_size)
 589                 goto fail_bad;
 590
 591         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 592                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
 593                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 594                 goto fail_bad;
 595         }
 596
 597         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 598         fm_pos += sizeof(*fmpl1);
 599         if (fm_pos >= fm_size)
 600                 goto fail_bad;
 601         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 602                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 603                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 604                 goto fail_bad;
 605         }
 606
 607         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 608         fm_pos += sizeof(*fmpl2);
 609         if (fm_pos >= fm_size)
 610                 goto fail_bad;
 611         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 612                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 613                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 614                 goto fail_bad;
 615         }
 616
 617         pool_size = be16_to_cpu(fmpl1->size);
 618         wl_pool_size = be16_to_cpu(fmpl2->size);
 619         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 620         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 621
 622         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 623                 ubi_err("bad pool size: %i", pool_size);
 624                 goto fail_bad;
 625         }
 626
 627         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 628                 ubi_err("bad WL pool size: %i", wl_pool_size);
 629                 goto fail_bad;
 630         }
 631
 632
 633         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 634             fm->max_pool_size < 0) {
 635                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
 636                 goto fail_bad;
 637         }
 638
 639         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 640             fm->max_wl_pool_size < 0) {
 641                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
 642                 goto fail_bad;
 643         }
 644
 645         /* read EC values from free list */
 646         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 647                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 648                 fm_pos += sizeof(*fmec);
 649                 if (fm_pos >= fm_size)
 650                         goto fail_bad;
 651
 652                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 653                         be32_to_cpu(fmec->ec), 0);
 654         }
 655
 656         /* read EC values from used list */
 657         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 658                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 659                 fm_pos += sizeof(*fmec);
 660                 if (fm_pos >= fm_size)
 661                         goto fail_bad;
 662
 663                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 664                         be32_to_cpu(fmec->ec), 0);
 665         }
 666
 667         /* read EC values from scrub list */
 668         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 669                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 670                 fm_pos += sizeof(*fmec);
 671                 if (fm_pos >= fm_size)
 672                         goto fail_bad;
 673
 674                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 675                         be32_to_cpu(fmec->ec), 1);
 676         }
 677
 678         /* read EC values from erase list */
 679         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 680                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 681                 fm_pos += sizeof(*fmec);
 682                 if (fm_pos >= fm_size)
 683                         goto fail_bad;
 684
 685                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 686                         be32_to_cpu(fmec->ec), 1);
 687         }
 688
 689         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 690         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 691
 692         /* Iterate over all volumes and read their EBA table */
 693         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 694                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 695                 fm_pos += sizeof(*fmvhdr);
 696                 if (fm_pos >= fm_size)
 697                         goto fail_bad;
 698
 699                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 700                         ubi_err("bad fastmap vol header magic: 0x%x, " \
 701                                 "expected: 0x%x",
 702                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 703                         goto fail_bad;
 704                 }
 705
 706                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 707                              be32_to_cpu(fmvhdr->used_ebs),
 708                              be32_to_cpu(fmvhdr->data_pad),
 709                              fmvhdr->vol_type,
 710                              be32_to_cpu(fmvhdr->last_eb_bytes));
 711
 712                 if (!av)
 713                         goto fail_bad;
 714
 715                 ai->vols_found++;
 716                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 717                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 718
 719                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 720                 fm_pos += sizeof(*fm_eba);
 721                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 722                 if (fm_pos >= fm_size)
 723                         goto fail_bad;
 724
 725                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 726                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
 727                                 "expected: 0x%x",
 728                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 729                         goto fail_bad;
 730                 }
 731
 732                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 733                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 734
 735                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 736                                 continue;
 737
 738                         aeb = NULL;
 739                         list_for_each_entry(tmp_aeb, &used, u.list) {
 740                                 if (tmp_aeb->pnum == pnum) {
 741                                         aeb = tmp_aeb;
 742                                         break;
 743                                 }
 744                         }
 745
 746                         /* This can happen if a PEB is already in an EBA known
 747                          * by this fastmap but the PEB itself is not in the used
 748                          * list.
 749                          * In this case the PEB can be within the fastmap pool
 750                          * or while writing the fastmap it was in the protection
 751                          * queue.
 752                          */
 753                         if (!aeb) {
 754                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 755                                                        GFP_KERNEL);
 756                                 if (!aeb) {
 757                                         ret = -ENOMEM;
 758
 759                                         goto fail;
 760                                 }
 761
 762                                 aeb->lnum = j;
 763                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 764                                 aeb->ec = -1;
 765                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 766                                 list_add_tail(&aeb->u.list, &eba_orphans);
 767                                 continue;
 768                         }
 769
 770                         aeb->lnum = j;
 771
 772                         if (av->highest_lnum <= aeb->lnum)
 773                                 av->highest_lnum = aeb->lnum;
 774
 775                         assign_aeb_to_av(ai, aeb, av);
 776
 777                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 778                                 aeb->pnum, aeb->lnum, av->vol_id);
 779                 }
 780
 781                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 782                 if (!ech) {
 783                         ret = -ENOMEM;
 784                         goto fail;
 785                 }
 786
 787                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 788                                          u.list) {
 789                         int err;
 790
 791                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 792                                 ubi_err("bad PEB in fastmap EBA orphan list");
 793                                 ret = UBI_BAD_FASTMAP;
 794                                 kfree(ech);
 795                                 goto fail;
 796                         }
 797
 798                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 799                         if (err && err != UBI_IO_BITFLIPS) {
 800                                 ubi_err("unable to read EC header! PEB:%i " \
 801                                         "err:%i", tmp_aeb->pnum, err);
 802                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 803                                 kfree(ech);
 804
 805                                 goto fail;
 806                         } else if (err == UBI_IO_BITFLIPS)
 807                                 tmp_aeb->scrub = 1;
 808
 809                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 810                         assign_aeb_to_av(ai, tmp_aeb, av);
 811                 }
 812
 813                 kfree(ech);
 814         }
 815
 816         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 817                         &eba_orphans, &free);
 818         if (ret)
 819                 goto fail;
 820
 821         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 822                         &eba_orphans, &free);
 823         if (ret)
 824                 goto fail;
 825
 826         if (max_sqnum > ai->max_sqnum)
 827                 ai->max_sqnum = max_sqnum;
 828
 829         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 830                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 831
 832         ubi_assert(list_empty(&used));
 833         ubi_assert(list_empty(&eba_orphans));
 834         ubi_assert(list_empty(&free));
 835
 836         /*
 837          * If fastmap is leaking PEBs (must not happen), raise a
 838          * fat warning and fall back to scanning mode.
 839          * We do this here because in ubi_wl_init() it's too late
 840          * and we cannot fall back to scanning.
 841          */
 842         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 843                     ai->bad_peb_count - fm->used_blocks))
 844                 goto fail_bad;
 845
 846         return 0;
 847
 848 fail_bad:
 849         ret = UBI_BAD_FASTMAP;
 850 fail:
 851         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 852                 list_del(&tmp_aeb->u.list);
 853                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 854         }
 855         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
 856                 list_del(&tmp_aeb->u.list);
 857                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 858         }
 859         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 860                 list_del(&tmp_aeb->u.list);
 861                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 862         }
 863
 864         return ret;
 865 }
 866
 867 /**
 868  * ubi_scan_fastmap - scan the fastmap.
 869  * @ubi: UBI device object
 870  * @ai: UBI attach info to be filled
 871  * @fm_anchor: The fastmap starts at this PEB
 872  *
 873  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 874  * UBI_BAD_FASTMAP if one was found but is not usable.
 875  * < 0 indicates an internal error.
 876  */
 877 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 878                      int fm_anchor)
 879 {
 880         struct ubi_fm_sb *fmsb, *fmsb2;
 881         struct ubi_vid_hdr *vh;
 882         struct ubi_ec_hdr *ech;
 883         struct ubi_fastmap_layout *fm;
 884         int i, used_blocks, pnum, ret = 0;
 885         size_t fm_size;
 886         __be32 crc, tmp_crc;
 887         unsigned long long sqnum = 0;
 888
 889         mutex_lock(&ubi->fm_mutex);
 890         memset(ubi->fm_buf, 0, ubi->fm_size);
 891
 892         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 893         if (!fmsb) {
 894                 ret = -ENOMEM;
 895                 goto out;
 896         }
 897
 898         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 899         if (!fm) {
 900                 ret = -ENOMEM;
 901                 kfree(fmsb);
 902                 goto out;
 903         }
 904
 905         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 906         if (ret && ret != UBI_IO_BITFLIPS)
 907                 goto free_fm_sb;
 908         else if (ret == UBI_IO_BITFLIPS)
 909                 fm->to_be_tortured[0] = 1;
 910
 911         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 912                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
 913                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 914                 ret = UBI_BAD_FASTMAP;
 915                 goto free_fm_sb;
 916         }
 917
 918         if (fmsb->version != UBI_FM_FMT_VERSION) {
 919                 ubi_err("bad fastmap version: %i, expected: %i",
 920                         fmsb->version, UBI_FM_FMT_VERSION);
 921                 ret = UBI_BAD_FASTMAP;
 922                 goto free_fm_sb;
 923         }
 924
 925         used_blocks = be32_to_cpu(fmsb->used_blocks);
 926         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 927                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
 928                 ret = UBI_BAD_FASTMAP;
 929                 goto free_fm_sb;
 930         }
 931
 932         fm_size = ubi->leb_size * used_blocks;
 933         if (fm_size != ubi->fm_size) {
 934                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
 935                         ubi->fm_size);
 936                 ret = UBI_BAD_FASTMAP;
 937                 goto free_fm_sb;
 938         }
 939
 940         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 941         if (!ech) {
 942                 ret = -ENOMEM;
 943                 goto free_fm_sb;
 944         }
 945
 946         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 947         if (!vh) {
 948                 ret = -ENOMEM;
 949                 goto free_hdr;
 950         }
 951
 952         for (i = 0; i < used_blocks; i++) {
 953                 int image_seq;
 954
 955                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 956
 957                 if (ubi_io_is_bad(ubi, pnum)) {
 958                         ret = UBI_BAD_FASTMAP;
 959                         goto free_hdr;
 960                 }
 961
 962                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 963                 if (ret && ret != UBI_IO_BITFLIPS) {
 964                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
 965                                 i, pnum);
 966                         if (ret > 0)
 967                                 ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 } else if (ret == UBI_IO_BITFLIPS)
 970                         fm->to_be_tortured[i] = 1;
 971
 972                 image_seq = be32_to_cpu(ech->image_seq);
 973                 if (!ubi->image_seq)
 974                         ubi->image_seq = image_seq;
 975
 976                 /*
 977                  * Older UBI implementations have image_seq set to zero, so
 978                  * we shouldn't fail if image_seq == 0.
 979                  */
 980                 if (image_seq && (image_seq != ubi->image_seq)) {
 981                         ubi_err("wrong image seq:%d instead of %d",
 982                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 983                         ret = UBI_BAD_FASTMAP;
 984                         goto free_hdr;
 985                 }
 986
 987                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 988                 if (ret && ret != UBI_IO_BITFLIPS) {
 989                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
 990                                 i, pnum);
 991                         goto free_hdr;
 992                 }
 993
 994                 if (i == 0) {
 995                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 996                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
 997                                         " expected: 0x%x",
 998                                         be32_to_cpu(vh->vol_id),
 999                                         UBI_FM_SB_VOLUME_ID);
1000                                 ret = UBI_BAD_FASTMAP;
1001                                 goto free_hdr;
1002                         }
1003                 } else {
1004                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1005                                 ubi_err("bad fastmap data vol_id: 0x%x," \
1006                                         " expected: 0x%x",
1007                                         be32_to_cpu(vh->vol_id),
1008                                         UBI_FM_DATA_VOLUME_ID);
1009                                 ret = UBI_BAD_FASTMAP;
1010                                 goto free_hdr;
1011                         }
1012                 }
1013
1014                 if (sqnum < be64_to_cpu(vh->sqnum))
1015                         sqnum = be64_to_cpu(vh->sqnum);
1016
1017                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1018                                   ubi->leb_start, ubi->leb_size);
1019                 if (ret && ret != UBI_IO_BITFLIPS) {
1020                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
1021                                 "err: %i)", i, pnum, ret);
1022                         goto free_hdr;
1023                 }
1024         }
1025
1026         kfree(fmsb);
1027         fmsb = NULL;
1028
1029         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1030         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1031         fmsb2->data_crc = 0;
1032         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1033         if (crc != tmp_crc) {
1034                 ubi_err("fastmap data CRC is invalid");
1035                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1036                 ret = UBI_BAD_FASTMAP;
1037                 goto free_hdr;
1038         }
1039
1040         fmsb2->sqnum = sqnum;
1041
1042         fm->used_blocks = used_blocks;
1043
1044         ret = ubi_attach_fastmap(ubi, ai, fm);
1045         if (ret) {
1046                 if (ret > 0)
1047                         ret = UBI_BAD_FASTMAP;
1048                 goto free_hdr;
1049         }
1050
1051         for (i = 0; i < used_blocks; i++) {
1052                 struct ubi_wl_entry *e;
1053
1054                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1055                 if (!e) {
1056                         while (i--)
1057                                 kfree(fm->e[i]);
1058
1059                         ret = -ENOMEM;
1060                         goto free_hdr;
1061                 }
1062
1063                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1064                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1065                 fm->e[i] = e;
1066         }
1067
1068         ubi->fm = fm;
1069         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1070         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1071         ubi_msg("attached by fastmap");
1072         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1073         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1074         ubi->fm_disabled = 0;
1075         ubi->fast_attach = 1;
1076
1077         ubi_free_vid_hdr(ubi, vh);
1078         kfree(ech);
1079 out:
1080         mutex_unlock(&ubi->fm_mutex);
1081         if (ret == UBI_BAD_FASTMAP)
1082                 ubi_err("Attach by fastmap failed, doing a full scan!");
1083         return ret;
1084
1085 free_hdr:
1086         ubi_free_vid_hdr(ubi, vh);
1087         kfree(ech);
1088 free_fm_sb:
1089         kfree(fmsb);
1090         kfree(fm);
1091         goto out;
1092 }
1093
1094 /**
1095  * ubi_write_fastmap - writes a fastmap.
1096  * @ubi: UBI device object
1097  * @new_fm: the to be written fastmap
1098  *
1099  * Returns 0 on success, < 0 indicates an internal error.
1100  */
1101 static int ubi_write_fastmap(struct ubi_device *ubi,
1102                              struct ubi_fastmap_layout *new_fm)
1103 {
1104         size_t fm_pos = 0;
1105         void *fm_raw;
1106         struct ubi_fm_sb *fmsb;
1107         struct ubi_fm_hdr *fmh;
1108         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1109         struct ubi_fm_ec *fec;
1110         struct ubi_fm_volhdr *fvh;
1111         struct ubi_fm_eba *feba;
1112         struct rb_node *node;
1113         struct ubi_wl_entry *wl_e;
1114         struct ubi_volume *vol;
1115         struct ubi_vid_hdr *avhdr, *dvhdr;
1116         struct ubi_work *ubi_wrk;
1117         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1118         int scrub_peb_count, erase_peb_count;
1119
1120         fm_raw = ubi->fm_buf;
1121         memset(ubi->fm_buf, 0, ubi->fm_size);
1122
1123         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1124         if (!avhdr) {
1125                 ret = -ENOMEM;
1126                 goto out;
1127         }
1128
1129         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1130         if (!dvhdr) {
1131                 ret = -ENOMEM;
1132                 goto out_kfree;
1133         }
1134
1135         spin_lock(&ubi->volumes_lock);
1136         spin_lock(&ubi->wl_lock);
1137
1138         fmsb = (struct ubi_fm_sb *)fm_raw;
1139         fm_pos += sizeof(*fmsb);
1140         ubi_assert(fm_pos <= ubi->fm_size);
1141
1142         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1143         fm_pos += sizeof(*fmh);
1144         ubi_assert(fm_pos <= ubi->fm_size);
1145
1146         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1147         fmsb->version = UBI_FM_FMT_VERSION;
1148         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1149         /* the max sqnum will be filled in while *reading* the fastmap */
1150         fmsb->sqnum = 0;
1151
1152         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1153         free_peb_count = 0;
1154         used_peb_count = 0;
1155         scrub_peb_count = 0;
1156         erase_peb_count = 0;
1157         vol_count = 0;
1158
1159         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1160         fm_pos += sizeof(*fmpl1);
1161         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1162         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1163         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1164
1165         for (i = 0; i < ubi->fm_pool.size; i++)
1166                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1167
1168         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1169         fm_pos += sizeof(*fmpl2);
1170         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1171         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1172         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1173
1174         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1175                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1176
1177         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1178                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1179                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1180
1181                 fec->pnum = cpu_to_be32(wl_e->pnum);
1182                 fec->ec = cpu_to_be32(wl_e->ec);
1183
1184                 free_peb_count++;
1185                 fm_pos += sizeof(*fec);
1186                 ubi_assert(fm_pos <= ubi->fm_size);
1187         }
1188         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1189
1190         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1191                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1192                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1193
1194                 fec->pnum = cpu_to_be32(wl_e->pnum);
1195                 fec->ec = cpu_to_be32(wl_e->ec);
1196
1197                 used_peb_count++;
1198                 fm_pos += sizeof(*fec);
1199                 ubi_assert(fm_pos <= ubi->fm_size);
1200         }
1201         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1202
1203         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1204                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1205                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1206
1207                 fec->pnum = cpu_to_be32(wl_e->pnum);
1208                 fec->ec = cpu_to_be32(wl_e->ec);
1209
1210                 scrub_peb_count++;
1211                 fm_pos += sizeof(*fec);
1212                 ubi_assert(fm_pos <= ubi->fm_size);
1213         }
1214         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1215
1216
1217         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1218                 if (ubi_is_erase_work(ubi_wrk)) {
1219                         wl_e = ubi_wrk->e;
1220                         ubi_assert(wl_e);
1221
1222                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1223
1224                         fec->pnum = cpu_to_be32(wl_e->pnum);
1225                         fec->ec = cpu_to_be32(wl_e->ec);
1226
1227                         erase_peb_count++;
1228                         fm_pos += sizeof(*fec);
1229                         ubi_assert(fm_pos <= ubi->fm_size);
1230                 }
1231         }
1232         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1233
1234         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1235                 vol = ubi->volumes[i];
1236
1237                 if (!vol)
1238                         continue;
1239
1240                 vol_count++;
1241
1242                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1243                 fm_pos += sizeof(*fvh);
1244                 ubi_assert(fm_pos <= ubi->fm_size);
1245
1246                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1247                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1248                 fvh->vol_type = vol->vol_type;
1249                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1250                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1251                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1252
1253                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1254                         vol->vol_type == UBI_STATIC_VOLUME);
1255
1256                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1257                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1258                 ubi_assert(fm_pos <= ubi->fm_size);
1259
1260                 for (j = 0; j < vol->reserved_pebs; j++)
1261                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1262
1263                 feba->reserved_pebs = cpu_to_be32(j);
1264                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1265         }
1266         fmh->vol_count = cpu_to_be32(vol_count);
1267         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1268
1269         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1270         avhdr->lnum = 0;
1271
1272         spin_unlock(&ubi->wl_lock);
1273         spin_unlock(&ubi->volumes_lock);
1274
1275         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1276         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1277         if (ret) {
1278                 ubi_err("unable to write vid_hdr to fastmap SB!");
1279                 goto out_kfree;
1280         }
1281
1282         for (i = 0; i < new_fm->used_blocks; i++) {
1283                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1284                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1285         }
1286
1287         fmsb->data_crc = 0;
1288         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1289                                            ubi->fm_size));
1290
1291         for (i = 1; i < new_fm->used_blocks; i++) {
1292                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1293                 dvhdr->lnum = cpu_to_be32(i);
1294                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1295                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1296                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1297                 if (ret) {
1298                         ubi_err("unable to write vid_hdr to PEB %i!",
1299                                 new_fm->e[i]->pnum);
1300                         goto out_kfree;
1301                 }
1302         }
1303
1304         for (i = 0; i < new_fm->used_blocks; i++) {
1305                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1306                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1307                 if (ret) {
1308                         ubi_err("unable to write fastmap to PEB %i!",
1309                                 new_fm->e[i]->pnum);
1310                         goto out_kfree;
1311                 }
1312         }
1313
1314         ubi_assert(new_fm);
1315         ubi->fm = new_fm;
1316
1317         dbg_bld("fastmap written!");
1318
1319 out_kfree:
1320         ubi_free_vid_hdr(ubi, avhdr);
1321         ubi_free_vid_hdr(ubi, dvhdr);
1322 out:
1323         return ret;
1324 }
1325
1326 /**
1327  * erase_block - Manually erase a PEB.
1328  * @ubi: UBI device object
1329  * @pnum: PEB to be erased
1330  *
1331  * Returns the new EC value on success, < 0 indicates an internal error.
1332  */
1333 static int erase_block(struct ubi_device *ubi, int pnum)
1334 {
1335         int ret;
1336         struct ubi_ec_hdr *ec_hdr;
1337         long long ec;
1338
1339         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1340         if (!ec_hdr)
1341                 return -ENOMEM;
1342
1343         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1344         if (ret < 0)
1345                 goto out;
1346         else if (ret && ret != UBI_IO_BITFLIPS) {
1347                 ret = -EINVAL;
1348                 goto out;
1349         }
1350
1351         ret = ubi_io_sync_erase(ubi, pnum, 0);
1352         if (ret < 0)
1353                 goto out;
1354
1355         ec = be64_to_cpu(ec_hdr->ec);
1356         ec += ret;
1357         if (ec > UBI_MAX_ERASECOUNTER) {
1358                 ret = -EINVAL;
1359                 goto out;
1360         }
1361
1362         ec_hdr->ec = cpu_to_be64(ec);
1363         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1364         if (ret < 0)
1365                 goto out;
1366
1367         ret = ec;
1368 out:
1369         kfree(ec_hdr);
1370         return ret;
1371 }
1372
1373 /**
1374  * invalidate_fastmap - destroys a fastmap.
1375  * @ubi: UBI device object
1376  * @fm: the fastmap to be destroyed
1377  *
1378  * Returns 0 on success, < 0 indicates an internal error.
1379  */
1380 static int invalidate_fastmap(struct ubi_device *ubi,
1381                               struct ubi_fastmap_layout *fm)
1382 {
1383         int ret;
1384         struct ubi_vid_hdr *vh;
1385
1386         ret = erase_block(ubi, fm->e[0]->pnum);
1387         if (ret < 0)
1388                 return ret;
1389
1390         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1391         if (!vh)
1392                 return -ENOMEM;
1393
1394         /* deleting the current fastmap SB is not enough, an old SB may exist,
1395          * so create a (corrupted) SB such that fastmap will find it and fall
1396          * back to scanning mode in any case */
1397         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1398         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1399
1400         return ret;
1401 }
1402
1403 /**
1404  * ubi_update_fastmap - will be called by UBI if a volume changes or
1405  * a fastmap pool becomes full.
1406  * @ubi: UBI device object
1407  *
1408  * Returns 0 on success, < 0 indicates an internal error.
1409  */
1410 int ubi_update_fastmap(struct ubi_device *ubi)
1411 {
1412         int ret, i;
1413         struct ubi_fastmap_layout *new_fm, *old_fm;
1414         struct ubi_wl_entry *tmp_e;
1415
1416         mutex_lock(&ubi->fm_mutex);
1417         down_write(&ubi->work_sem);
1418         down_write(&ubi->fm_sem);
1419
1420         ubi_refill_pools(ubi);
1421
1422         if (ubi->ro_mode || ubi->fm_disabled) {
1423                 up_write(&ubi->fm_sem);
1424                 up_write(&ubi->work_sem);
1425                 mutex_unlock(&ubi->fm_mutex);
1426                 return 0;
1427         }
1428
1429         ret = ubi_ensure_anchor_pebs(ubi);
1430         if (ret) {
1431                 up_write(&ubi->fm_sem);
1432                 up_write(&ubi->work_sem);
1433                 mutex_unlock(&ubi->fm_mutex);
1434                 return ret;
1435         }
1436
1437         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1438         if (!new_fm) {
1439                 up_write(&ubi->fm_sem);
1440                 up_write(&ubi->work_sem);
1441                 mutex_unlock(&ubi->fm_mutex);
1442                 return -ENOMEM;
1443         }
1444
1445         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1446
1447         for (i = 0; i < new_fm->used_blocks; i++) {
1448                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1449                 if (!new_fm->e[i]) {
1450                         while (i--)
1451                                 kfree(new_fm->e[i]);
1452
1453                         kfree(new_fm);
1454                         mutex_unlock(&ubi->fm_mutex);
1455                         return -ENOMEM;
1456                 }
1457         }
1458
1459         old_fm = ubi->fm;
1460         ubi->fm = NULL;
1461
1462         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1463                 ubi_err("fastmap too large");
1464                 ret = -ENOSPC;
1465                 goto err;
1466         }
1467
1468         for (i = 1; i < new_fm->used_blocks; i++) {
1469                 spin_lock(&ubi->wl_lock);
1470                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1471                 spin_unlock(&ubi->wl_lock);
1472
1473                 if (!tmp_e && !old_fm) {
1474                         int j;
1475                         ubi_err("could not get any free erase block");
1476
1477                         for (j = 1; j < i; j++)
1478                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1479
1480                         ret = -ENOSPC;
1481                         goto err;
1482                 } else if (!tmp_e && old_fm) {
1483                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1484                         if (ret < 0) {
1485                                 int j;
1486
1487                                 for (j = 1; j < i; j++)
1488                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1489                                                           j, 0);
1490
1491                                 ubi_err("could not erase old fastmap PEB");
1492                                 goto err;
1493                         }
1494
1495                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1496                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1497                 } else {
1498                         new_fm->e[i]->pnum = tmp_e->pnum;
1499                         new_fm->e[i]->ec = tmp_e->ec;
1500
1501                         if (old_fm)
1502                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1503                                                   old_fm->to_be_tortured[i]);
1504                 }
1505         }
1506
1507         spin_lock(&ubi->wl_lock);
1508         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1509         spin_unlock(&ubi->wl_lock);
1510
1511         if (old_fm) {
1512                 /* no fresh anchor PEB was found, reuse the old one */
1513                 if (!tmp_e) {
1514                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1515                         if (ret < 0) {
1516                                 int i;
1517                                 ubi_err("could not erase old anchor PEB");
1518
1519                                 for (i = 1; i < new_fm->used_blocks; i++)
1520                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1521                                                           i, 0);
1522                                 goto err;
1523                         }
1524
1525                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1526                         new_fm->e[0]->ec = ret;
1527                 } else {
1528                         /* we've got a new anchor PEB, return the old one */
1529                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1530                                           old_fm->to_be_tortured[0]);
1531
1532                         new_fm->e[0]->pnum = tmp_e->pnum;
1533                         new_fm->e[0]->ec = tmp_e->ec;
1534                 }
1535         } else {
1536                 if (!tmp_e) {
1537                         int i;
1538                         ubi_err("could not find any anchor PEB");
1539
1540                         for (i = 1; i < new_fm->used_blocks; i++)
1541                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1542
1543                         ret = -ENOSPC;
1544                         goto err;
1545                 }
1546
1547                 new_fm->e[0]->pnum = tmp_e->pnum;
1548                 new_fm->e[0]->ec = tmp_e->ec;
1549         }
1550
1551         ret = ubi_write_fastmap(ubi, new_fm);
1552
1553         if (ret)
1554                 goto err;
1555
1556 out_unlock:
1557         up_write(&ubi->fm_sem);
1558         up_write(&ubi->work_sem);
1559         mutex_unlock(&ubi->fm_mutex);
1560         kfree(old_fm);
1561         return ret;
1562
1563 err:
1564         kfree(new_fm);
1565
1566         ubi_warn("Unable to write new fastmap, err=%i", ret);
1567
1568         ret = 0;
1569         if (old_fm) {
1570                 ret = invalidate_fastmap(ubi, old_fm);
1571                 if (ret < 0)
1572                         ubi_err("Unable to invalidiate current fastmap!");
1573                 else if (ret)
1574                         ret = 0;
1575         }
1576         goto out_unlock;
1577 }