drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Copyright (c) 2014 sigma star gmbh
   4  * Author: Richard Weinberger <richard@nod.at>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/crc32.h>
  18 #include <linux/bitmap.h>
  19 #include "ubi.h"
  20
  21 /**
  22  * init_seen - allocate memory for used for debugging.
  23  * @ubi: UBI device description object
  24  */
  25 static inline unsigned long *init_seen(struct ubi_device *ubi)
  26 {
  27         unsigned long *ret;
  28
  29         if (!ubi_dbg_chk_fastmap(ubi))
  30                 return NULL;
  31
  32         ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  33                       GFP_KERNEL);
  34         if (!ret)
  35                 return ERR_PTR(-ENOMEM);
  36
  37         return ret;
  38 }
  39
  40 /**
  41  * free_seen - free the seen logic integer array.
  42  * @seen: integer array of @ubi->peb_count size
  43  */
  44 static inline void free_seen(unsigned long *seen)
  45 {
  46         kfree(seen);
  47 }
  48
  49 /**
  50  * set_seen - mark a PEB as seen.
  51  * @ubi: UBI device description object
  52  * @pnum: The PEB to be makred as seen
  53  * @seen: integer array of @ubi->peb_count size
  54  */
  55 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  56 {
  57         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  58                 return;
  59
  60         set_bit(pnum, seen);
  61 }
  62
  63 /**
  64  * self_check_seen - check whether all PEB have been seen by fastmap.
  65  * @ubi: UBI device description object
  66  * @seen: integer array of @ubi->peb_count size
  67  */
  68 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  69 {
  70         int pnum, ret = 0;
  71
  72         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  73                 return 0;
  74
  75         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  76                 if (test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  77                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  78                         ret = -EINVAL;
  79                 }
  80         }
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  87  * @ubi: UBI device description object
  88  */
  89 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  90 {
  91         size_t size;
  92
  93         size = sizeof(struct ubi_fm_sb) +
  94                 sizeof(struct ubi_fm_hdr) +
  95                 sizeof(struct ubi_fm_scan_pool) +
  96                 sizeof(struct ubi_fm_scan_pool) +
  97                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  98                 (sizeof(struct ubi_fm_eba) +
  99                 (ubi->peb_count * sizeof(__be32))) +
 100                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
 101         return roundup(size, ubi->leb_size);
 102 }
 103
 104
 105 /**
 106  * new_fm_vhdr - allocate a new volume header for fastmap usage.
 107  * @ubi: UBI device description object
 108  * @vol_id: the VID of the new header
 109  *
 110  * Returns a new struct ubi_vid_hdr on success.
 111  * NULL indicates out of memory.
 112  */
 113 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
 114 {
 115         struct ubi_vid_hdr *new;
 116
 117         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 118         if (!new)
 119                 goto out;
 120
 121         new->vol_type = UBI_VID_DYNAMIC;
 122         new->vol_id = cpu_to_be32(vol_id);
 123
 124         /* UBI implementations without fastmap support have to delete the
 125          * fastmap.
 126          */
 127         new->compat = UBI_COMPAT_DELETE;
 128
 129 out:
 130         return new;
 131 }
 132
 133 /**
 134  * add_aeb - create and add a attach erase block to a given list.
 135  * @ai: UBI attach info object
 136  * @list: the target list
 137  * @pnum: PEB number of the new attach erase block
 138  * @ec: erease counter of the new LEB
 139  * @scrub: scrub this PEB after attaching
 140  *
 141  * Returns 0 on success, < 0 indicates an internal error.
 142  */
 143 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 144                    int pnum, int ec, int scrub)
 145 {
 146         struct ubi_ainf_peb *aeb;
 147
 148         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
 149         if (!aeb)
 150                 return -ENOMEM;
 151
 152         aeb->pnum = pnum;
 153         aeb->ec = ec;
 154         aeb->lnum = -1;
 155         aeb->scrub = scrub;
 156         aeb->copy_flag = aeb->sqnum = 0;
 157
 158         ai->ec_sum += aeb->ec;
 159         ai->ec_count++;
 160
 161         if (ai->max_ec < aeb->ec)
 162                 ai->max_ec = aeb->ec;
 163
 164         if (ai->min_ec > aeb->ec)
 165                 ai->min_ec = aeb->ec;
 166
 167         list_add_tail(&aeb->u.list, list);
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * add_vol - create and add a new volume to ubi_attach_info.
 174  * @ai: ubi_attach_info object
 175  * @vol_id: VID of the new volume
 176  * @used_ebs: number of used EBS
 177  * @data_pad: data padding value of the new volume
 178  * @vol_type: volume type
 179  * @last_eb_bytes: number of bytes in the last LEB
 180  *
 181  * Returns the new struct ubi_ainf_volume on success.
 182  * NULL indicates an error.
 183  */
 184 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 185                                        int used_ebs, int data_pad, u8 vol_type,
 186                                        int last_eb_bytes)
 187 {
 188         struct ubi_ainf_volume *av;
 189         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 190
 191         while (*p) {
 192                 parent = *p;
 193                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 194
 195                 if (vol_id > av->vol_id)
 196                         p = &(*p)->rb_left;
 197                 else if (vol_id < av->vol_id)
 198                         p = &(*p)->rb_right;
 199                 else
 200                         return ERR_PTR(-EINVAL);
 201         }
 202
 203         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 204         if (!av)
 205                 goto out;
 206
 207         av->highest_lnum = av->leb_count = av->used_ebs = 0;
 208         av->vol_id = vol_id;
 209         av->data_pad = data_pad;
 210         av->last_data_size = last_eb_bytes;
 211         av->compat = 0;
 212         av->vol_type = vol_type;
 213         av->root = RB_ROOT;
 214         if (av->vol_type == UBI_STATIC_VOLUME)
 215                 av->used_ebs = used_ebs;
 216
 217         dbg_bld("found volume (ID %i)", vol_id);
 218
 219         rb_link_node(&av->rb, parent, p);
 220         rb_insert_color(&av->rb, &ai->volumes);
 221
 222 out:
 223         return av;
 224 }
 225
 226 /**
 227  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 228  * from it's original list.
 229  * @ai: ubi_attach_info object
 230  * @aeb: the to be assigned SEB
 231  * @av: target scan volume
 232  */
 233 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 234                              struct ubi_ainf_peb *aeb,
 235                              struct ubi_ainf_volume *av)
 236 {
 237         struct ubi_ainf_peb *tmp_aeb;
 238         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 239
 240         p = &av->root.rb_node;
 241         while (*p) {
 242                 parent = *p;
 243
 244                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 245                 if (aeb->lnum != tmp_aeb->lnum) {
 246                         if (aeb->lnum < tmp_aeb->lnum)
 247                                 p = &(*p)->rb_left;
 248                         else
 249                                 p = &(*p)->rb_right;
 250
 251                         continue;
 252                 } else
 253                         break;
 254         }
 255
 256         list_del(&aeb->u.list);
 257         av->leb_count++;
 258
 259         rb_link_node(&aeb->u.rb, parent, p);
 260         rb_insert_color(&aeb->u.rb, &av->root);
 261 }
 262
 263 /**
 264  * update_vol - inserts or updates a LEB which was found a pool.
 265  * @ubi: the UBI device object
 266  * @ai: attach info object
 267  * @av: the volume this LEB belongs to
 268  * @new_vh: the volume header derived from new_aeb
 269  * @new_aeb: the AEB to be examined
 270  *
 271  * Returns 0 on success, < 0 indicates an internal error.
 272  */
 273 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 274                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 275                       struct ubi_ainf_peb *new_aeb)
 276 {
 277         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 278         struct ubi_ainf_peb *aeb, *victim;
 279         int cmp_res;
 280
 281         while (*p) {
 282                 parent = *p;
 283                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 284
 285                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 286                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 287                                 p = &(*p)->rb_left;
 288                         else
 289                                 p = &(*p)->rb_right;
 290
 291                         continue;
 292                 }
 293
 294                 /* This case can happen if the fastmap gets written
 295                  * because of a volume change (creation, deletion, ..).
 296                  * Then a PEB can be within the persistent EBA and the pool.
 297                  */
 298                 if (aeb->pnum == new_aeb->pnum) {
 299                         ubi_assert(aeb->lnum == new_aeb->lnum);
 300                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 301
 302                         return 0;
 303                 }
 304
 305                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 306                 if (cmp_res < 0)
 307                         return cmp_res;
 308
 309                 /* new_aeb is newer */
 310                 if (cmp_res & 1) {
 311                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 312                                 GFP_KERNEL);
 313                         if (!victim)
 314                                 return -ENOMEM;
 315
 316                         victim->ec = aeb->ec;
 317                         victim->pnum = aeb->pnum;
 318                         list_add_tail(&victim->u.list, &ai->erase);
 319
 320                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 321                                 av->last_data_size =
 322                                         be32_to_cpu(new_vh->data_size);
 323
 324                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 325                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 326
 327                         aeb->ec = new_aeb->ec;
 328                         aeb->pnum = new_aeb->pnum;
 329                         aeb->copy_flag = new_vh->copy_flag;
 330                         aeb->scrub = new_aeb->scrub;
 331                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 332
 333                 /* new_aeb is older */
 334                 } else {
 335                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 336                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 337                         list_add_tail(&new_aeb->u.list, &ai->erase);
 338                 }
 339
 340                 return 0;
 341         }
 342         /* This LEB is new, let's add it to the volume */
 343
 344         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 345                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 346                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 347         }
 348
 349         if (av->vol_type == UBI_STATIC_VOLUME)
 350                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 351
 352         av->leb_count++;
 353
 354         rb_link_node(&new_aeb->u.rb, parent, p);
 355         rb_insert_color(&new_aeb->u.rb, &av->root);
 356
 357         return 0;
 358 }
 359
 360 /**
 361  * process_pool_aeb - we found a non-empty PEB in a pool.
 362  * @ubi: UBI device object
 363  * @ai: attach info object
 364  * @new_vh: the volume header derived from new_aeb
 365  * @new_aeb: the AEB to be examined
 366  *
 367  * Returns 0 on success, < 0 indicates an internal error.
 368  */
 369 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 370                             struct ubi_vid_hdr *new_vh,
 371                             struct ubi_ainf_peb *new_aeb)
 372 {
 373         int vol_id = be32_to_cpu(new_vh->vol_id);
 374         struct ubi_ainf_volume *av;
 375
 376         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 377                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 378
 379                 return 0;
 380         }
 381
 382         /* Find the volume this SEB belongs to */
 383         av = ubi_find_av(ai, vol_id);
 384         if (!av) {
 385                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 386                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 387                 return UBI_BAD_FASTMAP;
 388         }
 389
 390         ubi_assert(vol_id == av->vol_id);
 391
 392         return update_vol(ubi, ai, av, new_vh, new_aeb);
 393 }
 394
 395 /**
 396  * unmap_peb - unmap a PEB.
 397  * If fastmap detects a free PEB in the pool it has to check whether
 398  * this PEB has been unmapped after writing the fastmap.
 399  *
 400  * @ai: UBI attach info object
 401  * @pnum: The PEB to be unmapped
 402  */
 403 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 404 {
 405         struct ubi_ainf_volume *av;
 406         struct rb_node *node, *node2;
 407         struct ubi_ainf_peb *aeb;
 408
 409         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 410                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 411
 412                 for (node2 = rb_first(&av->root); node2;
 413                      node2 = rb_next(node2)) {
 414                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 415                         if (aeb->pnum == pnum) {
 416                                 rb_erase(&aeb->u.rb, &av->root);
 417                                 av->leb_count--;
 418                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 419                                 return;
 420                         }
 421                 }
 422         }
 423 }
 424
 425 /**
 426  * scan_pool - scans a pool for changed (no longer empty PEBs).
 427  * @ubi: UBI device object
 428  * @ai: attach info object
 429  * @pebs: an array of all PEB numbers in the to be scanned pool
 430  * @pool_size: size of the pool (number of entries in @pebs)
 431  * @max_sqnum: pointer to the maximal sequence number
 432  * @free: list of PEBs which are most likely free (and go into @ai->free)
 433  *
 434  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 435  * < 0 indicates an internal error.
 436  */
 437 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 438                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 439                      struct list_head *free)
 440 {
 441         struct ubi_vid_hdr *vh;
 442         struct ubi_ec_hdr *ech;
 443         struct ubi_ainf_peb *new_aeb;
 444         int i, pnum, err, ret = 0;
 445
 446         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 447         if (!ech)
 448                 return -ENOMEM;
 449
 450         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 451         if (!vh) {
 452                 kfree(ech);
 453                 return -ENOMEM;
 454         }
 455
 456         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 457
 458         /*
 459          * Now scan all PEBs in the pool to find changes which have been made
 460          * after the creation of the fastmap
 461          */
 462         for (i = 0; i < pool_size; i++) {
 463                 int scrub = 0;
 464                 int image_seq;
 465
 466                 pnum = be32_to_cpu(pebs[i]);
 467
 468                 if (ubi_io_is_bad(ubi, pnum)) {
 469                         ubi_err(ubi, "bad PEB in fastmap pool!");
 470                         ret = UBI_BAD_FASTMAP;
 471                         goto out;
 472                 }
 473
 474                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 475                 if (err && err != UBI_IO_BITFLIPS) {
 476                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 477                                 pnum, err);
 478                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 479                         goto out;
 480                 } else if (err == UBI_IO_BITFLIPS)
 481                         scrub = 1;
 482
 483                 /*
 484                  * Older UBI implementations have image_seq set to zero, so
 485                  * we shouldn't fail if image_seq == 0.
 486                  */
 487                 image_seq = be32_to_cpu(ech->image_seq);
 488
 489                 if (image_seq && (image_seq != ubi->image_seq)) {
 490                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 491                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 492                         ret = UBI_BAD_FASTMAP;
 493                         goto out;
 494                 }
 495
 496                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 497                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 498                         unsigned long long ec = be64_to_cpu(ech->ec);
 499                         unmap_peb(ai, pnum);
 500                         dbg_bld("Adding PEB to free: %i", pnum);
 501
 502                         if (err == UBI_IO_FF_BITFLIPS)
 503                                 scrub = 1;
 504
 505                         add_aeb(ai, free, pnum, ec, scrub);
 506                         continue;
 507                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 508                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 509
 510                         if (err == UBI_IO_BITFLIPS)
 511                                 scrub = 1;
 512
 513                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 514                                                    GFP_KERNEL);
 515                         if (!new_aeb) {
 516                                 ret = -ENOMEM;
 517                                 goto out;
 518                         }
 519
 520                         new_aeb->ec = be64_to_cpu(ech->ec);
 521                         new_aeb->pnum = pnum;
 522                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 523                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 524                         new_aeb->copy_flag = vh->copy_flag;
 525                         new_aeb->scrub = scrub;
 526
 527                         if (*max_sqnum < new_aeb->sqnum)
 528                                 *max_sqnum = new_aeb->sqnum;
 529
 530                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 531                         if (err) {
 532                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 533                                 goto out;
 534                         }
 535                 } else {
 536                         /* We are paranoid and fall back to scanning mode */
 537                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 538                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 539                         goto out;
 540                 }
 541
 542         }
 543
 544 out:
 545         ubi_free_vid_hdr(ubi, vh);
 546         kfree(ech);
 547         return ret;
 548 }
 549
 550 /**
 551  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 552  * @ai: The UBI attach info object
 553  */
 554 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 555 {
 556         struct ubi_ainf_peb *aeb;
 557         struct ubi_ainf_volume *av;
 558         struct rb_node *rb1, *rb2;
 559         int n = 0;
 560
 561         list_for_each_entry(aeb, &ai->erase, u.list)
 562                 n++;
 563
 564         list_for_each_entry(aeb, &ai->free, u.list)
 565                 n++;
 566
 567         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 568                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 569                         n++;
 570
 571         return n;
 572 }
 573
 574 /**
 575  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 576  * @ubi: UBI device object
 577  * @ai: UBI attach info object
 578  * @fm: the fastmap to be attached
 579  *
 580  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 581  * < 0 indicates an internal error.
 582  */
 583 static int ubi_attach_fastmap(struct ubi_device *ubi,
 584                               struct ubi_attach_info *ai,
 585                               struct ubi_fastmap_layout *fm)
 586 {
 587         struct list_head used, free;
 588         struct ubi_ainf_volume *av;
 589         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 590         struct ubi_fm_sb *fmsb;
 591         struct ubi_fm_hdr *fmhdr;
 592         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 593         struct ubi_fm_ec *fmec;
 594         struct ubi_fm_volhdr *fmvhdr;
 595         struct ubi_fm_eba *fm_eba;
 596         int ret, i, j, pool_size, wl_pool_size;
 597         size_t fm_pos = 0, fm_size = ubi->fm_size;
 598         unsigned long long max_sqnum = 0;
 599         void *fm_raw = ubi->fm_buf;
 600
 601         INIT_LIST_HEAD(&used);
 602         INIT_LIST_HEAD(&free);
 603         ai->min_ec = UBI_MAX_ERASECOUNTER;
 604
 605         fmsb = (struct ubi_fm_sb *)(fm_raw);
 606         ai->max_sqnum = fmsb->sqnum;
 607         fm_pos += sizeof(struct ubi_fm_sb);
 608         if (fm_pos >= fm_size)
 609                 goto fail_bad;
 610
 611         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 612         fm_pos += sizeof(*fmhdr);
 613         if (fm_pos >= fm_size)
 614                 goto fail_bad;
 615
 616         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 617                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 618                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 619                 goto fail_bad;
 620         }
 621
 622         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 623         fm_pos += sizeof(*fmpl);
 624         if (fm_pos >= fm_size)
 625                 goto fail_bad;
 626         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 627                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 628                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 629                 goto fail_bad;
 630         }
 631
 632         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 633         fm_pos += sizeof(*fmpl_wl);
 634         if (fm_pos >= fm_size)
 635                 goto fail_bad;
 636         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 637                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 638                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 639                 goto fail_bad;
 640         }
 641
 642         pool_size = be16_to_cpu(fmpl->size);
 643         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 644         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 645         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 646
 647         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 648                 ubi_err(ubi, "bad pool size: %i", pool_size);
 649                 goto fail_bad;
 650         }
 651
 652         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 653                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 654                 goto fail_bad;
 655         }
 656
 657
 658         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 659             fm->max_pool_size < 0) {
 660                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 661                 goto fail_bad;
 662         }
 663
 664         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 665             fm->max_wl_pool_size < 0) {
 666                 ubi_err(ubi, "bad maximal WL pool size: %i",
 667                         fm->max_wl_pool_size);
 668                 goto fail_bad;
 669         }
 670
 671         /* read EC values from free list */
 672         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 673                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 674                 fm_pos += sizeof(*fmec);
 675                 if (fm_pos >= fm_size)
 676                         goto fail_bad;
 677
 678                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 679                         be32_to_cpu(fmec->ec), 0);
 680         }
 681
 682         /* read EC values from used list */
 683         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 684                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 685                 fm_pos += sizeof(*fmec);
 686                 if (fm_pos >= fm_size)
 687                         goto fail_bad;
 688
 689                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 690                         be32_to_cpu(fmec->ec), 0);
 691         }
 692
 693         /* read EC values from scrub list */
 694         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 695                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 696                 fm_pos += sizeof(*fmec);
 697                 if (fm_pos >= fm_size)
 698                         goto fail_bad;
 699
 700                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 701                         be32_to_cpu(fmec->ec), 1);
 702         }
 703
 704         /* read EC values from erase list */
 705         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 706                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 707                 fm_pos += sizeof(*fmec);
 708                 if (fm_pos >= fm_size)
 709                         goto fail_bad;
 710
 711                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 712                         be32_to_cpu(fmec->ec), 1);
 713         }
 714
 715         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 716         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 717
 718         /* Iterate over all volumes and read their EBA table */
 719         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 720                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 721                 fm_pos += sizeof(*fmvhdr);
 722                 if (fm_pos >= fm_size)
 723                         goto fail_bad;
 724
 725                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 726                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 727                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 728                         goto fail_bad;
 729                 }
 730
 731                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 732                              be32_to_cpu(fmvhdr->used_ebs),
 733                              be32_to_cpu(fmvhdr->data_pad),
 734                              fmvhdr->vol_type,
 735                              be32_to_cpu(fmvhdr->last_eb_bytes));
 736
 737                 if (!av)
 738                         goto fail_bad;
 739                 if (PTR_ERR(av) == -EINVAL) {
 740                         ubi_err(ubi, "volume (ID %i) already exists",
 741                                 fmvhdr->vol_id);
 742                         goto fail_bad;
 743                 }
 744
 745                 ai->vols_found++;
 746                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 747                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 748
 749                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 750                 fm_pos += sizeof(*fm_eba);
 751                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 752                 if (fm_pos >= fm_size)
 753                         goto fail_bad;
 754
 755                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 756                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 757                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 758                         goto fail_bad;
 759                 }
 760
 761                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 762                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 763
 764                         if (pnum < 0)
 765                                 continue;
 766
 767                         aeb = NULL;
 768                         list_for_each_entry(tmp_aeb, &used, u.list) {
 769                                 if (tmp_aeb->pnum == pnum) {
 770                                         aeb = tmp_aeb;
 771                                         break;
 772                                 }
 773                         }
 774
 775                         if (!aeb) {
 776                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 777                                 goto fail_bad;
 778                         }
 779
 780                         aeb->lnum = j;
 781
 782                         if (av->highest_lnum <= aeb->lnum)
 783                                 av->highest_lnum = aeb->lnum;
 784
 785                         assign_aeb_to_av(ai, aeb, av);
 786
 787                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 788                                 aeb->pnum, aeb->lnum, av->vol_id);
 789                 }
 790         }
 791
 792         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 793         if (ret)
 794                 goto fail;
 795
 796         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 797         if (ret)
 798                 goto fail;
 799
 800         if (max_sqnum > ai->max_sqnum)
 801                 ai->max_sqnum = max_sqnum;
 802
 803         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 804                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 805
 806         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 807                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 808
 809         ubi_assert(list_empty(&free));
 810
 811         /*
 812          * If fastmap is leaking PEBs (must not happen), raise a
 813          * fat warning and fall back to scanning mode.
 814          * We do this here because in ubi_wl_init() it's too late
 815          * and we cannot fall back to scanning.
 816          */
 817         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 818                     ai->bad_peb_count - fm->used_blocks))
 819                 goto fail_bad;
 820
 821         return 0;
 822
 823 fail_bad:
 824         ret = UBI_BAD_FASTMAP;
 825 fail:
 826         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 827                 list_del(&tmp_aeb->u.list);
 828                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 829         }
 830         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 831                 list_del(&tmp_aeb->u.list);
 832                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 833         }
 834
 835         return ret;
 836 }
 837
 838 /**
 839  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 840  * @ai: UBI attach info to be filled
 841  */
 842 static int find_fm_anchor(struct ubi_attach_info *ai)
 843 {
 844         int ret = -1;
 845         struct ubi_ainf_peb *aeb;
 846         unsigned long long max_sqnum = 0;
 847
 848         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 849                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 850                         max_sqnum = aeb->sqnum;
 851                         ret = aeb->pnum;
 852                 }
 853         }
 854
 855         return ret;
 856 }
 857
 858 /**
 859  * ubi_scan_fastmap - scan the fastmap.
 860  * @ubi: UBI device object
 861  * @ai: UBI attach info to be filled
 862  * @scan_ai: UBI attach info from the first 64 PEBs,
 863  *           used to find the most recent Fastmap data structure
 864  *
 865  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 866  * UBI_BAD_FASTMAP if one was found but is not usable.
 867  * < 0 indicates an internal error.
 868  */
 869 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 870                      struct ubi_attach_info *scan_ai)
 871 {
 872         struct ubi_fm_sb *fmsb, *fmsb2;
 873         struct ubi_vid_hdr *vh;
 874         struct ubi_ec_hdr *ech;
 875         struct ubi_fastmap_layout *fm;
 876         struct ubi_ainf_peb *tmp_aeb, *aeb;
 877         int i, used_blocks, pnum, fm_anchor, ret = 0;
 878         size_t fm_size;
 879         __be32 crc, tmp_crc;
 880         unsigned long long sqnum = 0;
 881
 882         fm_anchor = find_fm_anchor(scan_ai);
 883         if (fm_anchor < 0)
 884                 return UBI_NO_FASTMAP;
 885
 886         /* Move all (possible) fastmap blocks into our new attach structure. */
 887         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 888                 list_move_tail(&aeb->u.list, &ai->fastmap);
 889
 890         down_write(&ubi->fm_protect);
 891         memset(ubi->fm_buf, 0, ubi->fm_size);
 892
 893         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 894         if (!fmsb) {
 895                 ret = -ENOMEM;
 896                 goto out;
 897         }
 898
 899         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 900         if (!fm) {
 901                 ret = -ENOMEM;
 902                 kfree(fmsb);
 903                 goto out;
 904         }
 905
 906         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 907         if (ret && ret != UBI_IO_BITFLIPS)
 908                 goto free_fm_sb;
 909         else if (ret == UBI_IO_BITFLIPS)
 910                 fm->to_be_tortured[0] = 1;
 911
 912         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 913                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 914                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 915                 ret = UBI_BAD_FASTMAP;
 916                 goto free_fm_sb;
 917         }
 918
 919         if (fmsb->version != UBI_FM_FMT_VERSION) {
 920                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 921                         fmsb->version, UBI_FM_FMT_VERSION);
 922                 ret = UBI_BAD_FASTMAP;
 923                 goto free_fm_sb;
 924         }
 925
 926         used_blocks = be32_to_cpu(fmsb->used_blocks);
 927         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 928                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 929                         used_blocks);
 930                 ret = UBI_BAD_FASTMAP;
 931                 goto free_fm_sb;
 932         }
 933
 934         fm_size = ubi->leb_size * used_blocks;
 935         if (fm_size != ubi->fm_size) {
 936                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 937                         fm_size, ubi->fm_size);
 938                 ret = UBI_BAD_FASTMAP;
 939                 goto free_fm_sb;
 940         }
 941
 942         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 943         if (!ech) {
 944                 ret = -ENOMEM;
 945                 goto free_fm_sb;
 946         }
 947
 948         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 949         if (!vh) {
 950                 ret = -ENOMEM;
 951                 goto free_hdr;
 952         }
 953
 954         for (i = 0; i < used_blocks; i++) {
 955                 int image_seq;
 956
 957                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 958
 959                 if (ubi_io_is_bad(ubi, pnum)) {
 960                         ret = UBI_BAD_FASTMAP;
 961                         goto free_hdr;
 962                 }
 963
 964                 if (i == 0 && pnum != fm_anchor) {
 965                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 966                                 pnum, fm_anchor);
 967                         ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 }
 970
 971                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 972                 if (ret && ret != UBI_IO_BITFLIPS) {
 973                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 974                                 i, pnum);
 975                         if (ret > 0)
 976                                 ret = UBI_BAD_FASTMAP;
 977                         goto free_hdr;
 978                 } else if (ret == UBI_IO_BITFLIPS)
 979                         fm->to_be_tortured[i] = 1;
 980
 981                 image_seq = be32_to_cpu(ech->image_seq);
 982                 if (!ubi->image_seq)
 983                         ubi->image_seq = image_seq;
 984
 985                 /*
 986                  * Older UBI implementations have image_seq set to zero, so
 987                  * we shouldn't fail if image_seq == 0.
 988                  */
 989                 if (image_seq && (image_seq != ubi->image_seq)) {
 990                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 991                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 992                         ret = UBI_BAD_FASTMAP;
 993                         goto free_hdr;
 994                 }
 995
 996                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 997                 if (ret && ret != UBI_IO_BITFLIPS) {
 998                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 999                                 i, pnum);
1000                         goto free_hdr;
1001                 }
1002
1003                 if (i == 0) {
1004                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1005                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1006                                         be32_to_cpu(vh->vol_id),
1007                                         UBI_FM_SB_VOLUME_ID);
1008                                 ret = UBI_BAD_FASTMAP;
1009                                 goto free_hdr;
1010                         }
1011                 } else {
1012                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1013                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1014                                         be32_to_cpu(vh->vol_id),
1015                                         UBI_FM_DATA_VOLUME_ID);
1016                                 ret = UBI_BAD_FASTMAP;
1017                                 goto free_hdr;
1018                         }
1019                 }
1020
1021                 if (sqnum < be64_to_cpu(vh->sqnum))
1022                         sqnum = be64_to_cpu(vh->sqnum);
1023
1024                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1025                                   ubi->leb_start, ubi->leb_size);
1026                 if (ret && ret != UBI_IO_BITFLIPS) {
1027                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1028                                 "err: %i)", i, pnum, ret);
1029                         goto free_hdr;
1030                 }
1031         }
1032
1033         kfree(fmsb);
1034         fmsb = NULL;
1035
1036         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1037         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1038         fmsb2->data_crc = 0;
1039         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1040         if (crc != tmp_crc) {
1041                 ubi_err(ubi, "fastmap data CRC is invalid");
1042                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1043                         tmp_crc, crc);
1044                 ret = UBI_BAD_FASTMAP;
1045                 goto free_hdr;
1046         }
1047
1048         fmsb2->sqnum = sqnum;
1049
1050         fm->used_blocks = used_blocks;
1051
1052         ret = ubi_attach_fastmap(ubi, ai, fm);
1053         if (ret) {
1054                 if (ret > 0)
1055                         ret = UBI_BAD_FASTMAP;
1056                 goto free_hdr;
1057         }
1058
1059         for (i = 0; i < used_blocks; i++) {
1060                 struct ubi_wl_entry *e;
1061
1062                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1063                 if (!e) {
1064                         while (i--)
1065                                 kfree(fm->e[i]);
1066
1067                         ret = -ENOMEM;
1068                         goto free_hdr;
1069                 }
1070
1071                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1072                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1073                 fm->e[i] = e;
1074         }
1075
1076         ubi->fm = fm;
1077         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1078         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1079         ubi_msg(ubi, "attached by fastmap");
1080         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1081         ubi_msg(ubi, "fastmap WL pool size: %d",
1082                 ubi->fm_wl_pool.max_size);
1083         ubi->fm_disabled = 0;
1084         ubi->fast_attach = 1;
1085
1086         ubi_free_vid_hdr(ubi, vh);
1087         kfree(ech);
1088 out:
1089         up_write(&ubi->fm_protect);
1090         if (ret == UBI_BAD_FASTMAP)
1091                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1092         return ret;
1093
1094 free_hdr:
1095         ubi_free_vid_hdr(ubi, vh);
1096         kfree(ech);
1097 free_fm_sb:
1098         kfree(fmsb);
1099         kfree(fm);
1100         goto out;
1101 }
1102
1103 /**
1104  * ubi_write_fastmap - writes a fastmap.
1105  * @ubi: UBI device object
1106  * @new_fm: the to be written fastmap
1107  *
1108  * Returns 0 on success, < 0 indicates an internal error.
1109  */
1110 static int ubi_write_fastmap(struct ubi_device *ubi,
1111                              struct ubi_fastmap_layout *new_fm)
1112 {
1113         size_t fm_pos = 0;
1114         void *fm_raw;
1115         struct ubi_fm_sb *fmsb;
1116         struct ubi_fm_hdr *fmh;
1117         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1118         struct ubi_fm_ec *fec;
1119         struct ubi_fm_volhdr *fvh;
1120         struct ubi_fm_eba *feba;
1121         struct ubi_wl_entry *wl_e;
1122         struct ubi_volume *vol;
1123         struct ubi_vid_hdr *avhdr, *dvhdr;
1124         struct ubi_work *ubi_wrk;
1125         struct rb_node *tmp_rb;
1126         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1127         int scrub_peb_count, erase_peb_count;
1128         unsigned long *seen_pebs = NULL;
1129
1130         fm_raw = ubi->fm_buf;
1131         memset(ubi->fm_buf, 0, ubi->fm_size);
1132
1133         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1134         if (!avhdr) {
1135                 ret = -ENOMEM;
1136                 goto out;
1137         }
1138
1139         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1140         if (!dvhdr) {
1141                 ret = -ENOMEM;
1142                 goto out_kfree;
1143         }
1144
1145         seen_pebs = init_seen(ubi);
1146         if (IS_ERR(seen_pebs)) {
1147                 ret = PTR_ERR(seen_pebs);
1148                 goto out_kfree;
1149         }
1150
1151         spin_lock(&ubi->volumes_lock);
1152         spin_lock(&ubi->wl_lock);
1153
1154         fmsb = (struct ubi_fm_sb *)fm_raw;
1155         fm_pos += sizeof(*fmsb);
1156         ubi_assert(fm_pos <= ubi->fm_size);
1157
1158         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1159         fm_pos += sizeof(*fmh);
1160         ubi_assert(fm_pos <= ubi->fm_size);
1161
1162         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1163         fmsb->version = UBI_FM_FMT_VERSION;
1164         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1165         /* the max sqnum will be filled in while *reading* the fastmap */
1166         fmsb->sqnum = 0;
1167
1168         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1169         free_peb_count = 0;
1170         used_peb_count = 0;
1171         scrub_peb_count = 0;
1172         erase_peb_count = 0;
1173         vol_count = 0;
1174
1175         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1176         fm_pos += sizeof(*fmpl);
1177         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1178         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1179         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1180
1181         for (i = 0; i < ubi->fm_pool.size; i++) {
1182                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1183                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1184         }
1185
1186         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1187         fm_pos += sizeof(*fmpl_wl);
1188         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1189         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1190         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1191
1192         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1193                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1194                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1195         }
1196
1197         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1198                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1199
1200                 fec->pnum = cpu_to_be32(wl_e->pnum);
1201                 set_seen(ubi, wl_e->pnum, seen_pebs);
1202                 fec->ec = cpu_to_be32(wl_e->ec);
1203
1204                 free_peb_count++;
1205                 fm_pos += sizeof(*fec);
1206                 ubi_assert(fm_pos <= ubi->fm_size);
1207         }
1208         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1209
1210         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1211                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1212
1213                 fec->pnum = cpu_to_be32(wl_e->pnum);
1214                 set_seen(ubi, wl_e->pnum, seen_pebs);
1215                 fec->ec = cpu_to_be32(wl_e->ec);
1216
1217                 used_peb_count++;
1218                 fm_pos += sizeof(*fec);
1219                 ubi_assert(fm_pos <= ubi->fm_size);
1220         }
1221
1222         ubi_for_each_protected_peb(ubi, i, wl_e) {
1223                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1224
1225                 fec->pnum = cpu_to_be32(wl_e->pnum);
1226                 set_seen(ubi, wl_e->pnum, seen_pebs);
1227                 fec->ec = cpu_to_be32(wl_e->ec);
1228
1229                 used_peb_count++;
1230                 fm_pos += sizeof(*fec);
1231                 ubi_assert(fm_pos <= ubi->fm_size);
1232         }
1233         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1234
1235         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1236                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1237
1238                 fec->pnum = cpu_to_be32(wl_e->pnum);
1239                 set_seen(ubi, wl_e->pnum, seen_pebs);
1240                 fec->ec = cpu_to_be32(wl_e->ec);
1241
1242                 scrub_peb_count++;
1243                 fm_pos += sizeof(*fec);
1244                 ubi_assert(fm_pos <= ubi->fm_size);
1245         }
1246         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1247
1248
1249         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1250                 if (ubi_is_erase_work(ubi_wrk)) {
1251                         wl_e = ubi_wrk->e;
1252                         ubi_assert(wl_e);
1253
1254                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1255
1256                         fec->pnum = cpu_to_be32(wl_e->pnum);
1257                         set_seen(ubi, wl_e->pnum, seen_pebs);
1258                         fec->ec = cpu_to_be32(wl_e->ec);
1259
1260                         erase_peb_count++;
1261                         fm_pos += sizeof(*fec);
1262                         ubi_assert(fm_pos <= ubi->fm_size);
1263                 }
1264         }
1265         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1266
1267         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1268                 vol = ubi->volumes[i];
1269
1270                 if (!vol)
1271                         continue;
1272
1273                 vol_count++;
1274
1275                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1276                 fm_pos += sizeof(*fvh);
1277                 ubi_assert(fm_pos <= ubi->fm_size);
1278
1279                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1280                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1281                 fvh->vol_type = vol->vol_type;
1282                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1283                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1284                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1285
1286                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1287                         vol->vol_type == UBI_STATIC_VOLUME);
1288
1289                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1290                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1291                 ubi_assert(fm_pos <= ubi->fm_size);
1292
1293                 for (j = 0; j < vol->reserved_pebs; j++)
1294                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1295
1296                 feba->reserved_pebs = cpu_to_be32(j);
1297                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1298         }
1299         fmh->vol_count = cpu_to_be32(vol_count);
1300         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1301
1302         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1303         avhdr->lnum = 0;
1304
1305         spin_unlock(&ubi->wl_lock);
1306         spin_unlock(&ubi->volumes_lock);
1307
1308         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1309         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1310         if (ret) {
1311                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1312                 goto out_kfree;
1313         }
1314
1315         for (i = 0; i < new_fm->used_blocks; i++) {
1316                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1317                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1318                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1319         }
1320
1321         fmsb->data_crc = 0;
1322         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1323                                            ubi->fm_size));
1324
1325         for (i = 1; i < new_fm->used_blocks; i++) {
1326                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1327                 dvhdr->lnum = cpu_to_be32(i);
1328                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1329                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1330                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1331                 if (ret) {
1332                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1333                                 new_fm->e[i]->pnum);
1334                         goto out_kfree;
1335                 }
1336         }
1337
1338         for (i = 0; i < new_fm->used_blocks; i++) {
1339                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1340                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1341                 if (ret) {
1342                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1343                                 new_fm->e[i]->pnum);
1344                         goto out_kfree;
1345                 }
1346         }
1347
1348         ubi_assert(new_fm);
1349         ubi->fm = new_fm;
1350
1351         ret = self_check_seen(ubi, seen_pebs);
1352         dbg_bld("fastmap written!");
1353
1354 out_kfree:
1355         ubi_free_vid_hdr(ubi, avhdr);
1356         ubi_free_vid_hdr(ubi, dvhdr);
1357         free_seen(seen_pebs);
1358 out:
1359         return ret;
1360 }
1361
1362 /**
1363  * erase_block - Manually erase a PEB.
1364  * @ubi: UBI device object
1365  * @pnum: PEB to be erased
1366  *
1367  * Returns the new EC value on success, < 0 indicates an internal error.
1368  */
1369 static int erase_block(struct ubi_device *ubi, int pnum)
1370 {
1371         int ret;
1372         struct ubi_ec_hdr *ec_hdr;
1373         long long ec;
1374
1375         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1376         if (!ec_hdr)
1377                 return -ENOMEM;
1378
1379         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1380         if (ret < 0)
1381                 goto out;
1382         else if (ret && ret != UBI_IO_BITFLIPS) {
1383                 ret = -EINVAL;
1384                 goto out;
1385         }
1386
1387         ret = ubi_io_sync_erase(ubi, pnum, 0);
1388         if (ret < 0)
1389                 goto out;
1390
1391         ec = be64_to_cpu(ec_hdr->ec);
1392         ec += ret;
1393         if (ec > UBI_MAX_ERASECOUNTER) {
1394                 ret = -EINVAL;
1395                 goto out;
1396         }
1397
1398         ec_hdr->ec = cpu_to_be64(ec);
1399         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1400         if (ret < 0)
1401                 goto out;
1402
1403         ret = ec;
1404 out:
1405         kfree(ec_hdr);
1406         return ret;
1407 }
1408
1409 /**
1410  * invalidate_fastmap - destroys a fastmap.
1411  * @ubi: UBI device object
1412  *
1413  * This function ensures that upon next UBI attach a full scan
1414  * is issued. We need this if UBI is about to write a new fastmap
1415  * but is unable to do so. In this case we have two options:
1416  * a) Make sure that the current fastmap will not be usued upon
1417  * attach time and contine or b) fall back to RO mode to have the
1418  * current fastmap in a valid state.
1419  * Returns 0 on success, < 0 indicates an internal error.
1420  */
1421 static int invalidate_fastmap(struct ubi_device *ubi)
1422 {
1423         int ret;
1424         struct ubi_fastmap_layout *fm;
1425         struct ubi_wl_entry *e;
1426         struct ubi_vid_hdr *vh = NULL;
1427
1428         if (!ubi->fm)
1429                 return 0;
1430
1431         ubi->fm = NULL;
1432
1433         ret = -ENOMEM;
1434         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1435         if (!fm)
1436                 goto out;
1437
1438         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1439         if (!vh)
1440                 goto out_free_fm;
1441
1442         ret = -ENOSPC;
1443         e = ubi_wl_get_fm_peb(ubi, 1);
1444         if (!e)
1445                 goto out_free_fm;
1446
1447         /*
1448          * Create fake fastmap such that UBI will fall back
1449          * to scanning mode.
1450          */
1451         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1452         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1453         if (ret < 0) {
1454                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1455                 goto out_free_fm;
1456         }
1457
1458         fm->used_blocks = 1;
1459         fm->e[0] = e;
1460
1461         ubi->fm = fm;
1462
1463 out:
1464         ubi_free_vid_hdr(ubi, vh);
1465         return ret;
1466
1467 out_free_fm:
1468         kfree(fm);
1469         goto out;
1470 }
1471
1472 /**
1473  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1474  * WL sub-system.
1475  * @ubi: UBI device object
1476  * @fm: fastmap layout object
1477  */
1478 static void return_fm_pebs(struct ubi_device *ubi,
1479                            struct ubi_fastmap_layout *fm)
1480 {
1481         int i;
1482
1483         if (!fm)
1484                 return;
1485
1486         for (i = 0; i < fm->used_blocks; i++) {
1487                 if (fm->e[i]) {
1488                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1489                                           fm->to_be_tortured[i]);
1490                         fm->e[i] = NULL;
1491                 }
1492         }
1493 }
1494
1495 /**
1496  * ubi_update_fastmap - will be called by UBI if a volume changes or
1497  * a fastmap pool becomes full.
1498  * @ubi: UBI device object
1499  *
1500  * Returns 0 on success, < 0 indicates an internal error.
1501  */
1502 int ubi_update_fastmap(struct ubi_device *ubi)
1503 {
1504         int ret, i, j;
1505         struct ubi_fastmap_layout *new_fm, *old_fm;
1506         struct ubi_wl_entry *tmp_e;
1507
1508         down_write(&ubi->fm_protect);
1509
1510         ubi_refill_pools(ubi);
1511
1512         if (ubi->ro_mode || ubi->fm_disabled) {
1513                 up_write(&ubi->fm_protect);
1514                 return 0;
1515         }
1516
1517         ret = ubi_ensure_anchor_pebs(ubi);
1518         if (ret) {
1519                 up_write(&ubi->fm_protect);
1520                 return ret;
1521         }
1522
1523         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1524         if (!new_fm) {
1525                 up_write(&ubi->fm_protect);
1526                 return -ENOMEM;
1527         }
1528
1529         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1530         old_fm = ubi->fm;
1531         ubi->fm = NULL;
1532
1533         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1534                 ubi_err(ubi, "fastmap too large");
1535                 ret = -ENOSPC;
1536                 goto err;
1537         }
1538
1539         for (i = 1; i < new_fm->used_blocks; i++) {
1540                 spin_lock(&ubi->wl_lock);
1541                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1542                 spin_unlock(&ubi->wl_lock);
1543
1544                 if (!tmp_e) {
1545                         if (old_fm && old_fm->e[i]) {
1546                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1547                                 if (ret < 0) {
1548                                         ubi_err(ubi, "could not erase old fastmap PEB");
1549
1550                                         for (j = 1; j < i; j++) {
1551                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1552                                                                   j, 0);
1553                                                 new_fm->e[j] = NULL;
1554                                         }
1555                                         goto err;
1556                                 }
1557                                 new_fm->e[i] = old_fm->e[i];
1558                                 old_fm->e[i] = NULL;
1559                         } else {
1560                                 ubi_err(ubi, "could not get any free erase block");
1561
1562                                 for (j = 1; j < i; j++) {
1563                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1564                                         new_fm->e[j] = NULL;
1565                                 }
1566
1567                                 ret = -ENOSPC;
1568                                 goto err;
1569                         }
1570                 } else {
1571                         new_fm->e[i] = tmp_e;
1572
1573                         if (old_fm && old_fm->e[i]) {
1574                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1575                                                   old_fm->to_be_tortured[i]);
1576                                 old_fm->e[i] = NULL;
1577                         }
1578                 }
1579         }
1580
1581         /* Old fastmap is larger than the new one */
1582         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1583                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1584                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1585                                           old_fm->to_be_tortured[i]);
1586                         old_fm->e[i] = NULL;
1587                 }
1588         }
1589
1590         spin_lock(&ubi->wl_lock);
1591         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1592         spin_unlock(&ubi->wl_lock);
1593
1594         if (old_fm) {
1595                 /* no fresh anchor PEB was found, reuse the old one */
1596                 if (!tmp_e) {
1597                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1598                         if (ret < 0) {
1599                                 ubi_err(ubi, "could not erase old anchor PEB");
1600
1601                                 for (i = 1; i < new_fm->used_blocks; i++) {
1602                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1603                                                           i, 0);
1604                                         new_fm->e[i] = NULL;
1605                                 }
1606                                 goto err;
1607                         }
1608                         new_fm->e[0] = old_fm->e[0];
1609                         new_fm->e[0]->ec = ret;
1610                         old_fm->e[0] = NULL;
1611                 } else {
1612                         /* we've got a new anchor PEB, return the old one */
1613                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1614                                           old_fm->to_be_tortured[0]);
1615                         new_fm->e[0] = tmp_e;
1616                         old_fm->e[0] = NULL;
1617                 }
1618         } else {
1619                 if (!tmp_e) {
1620                         ubi_err(ubi, "could not find any anchor PEB");
1621
1622                         for (i = 1; i < new_fm->used_blocks; i++) {
1623                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1624                                 new_fm->e[i] = NULL;
1625                         }
1626
1627                         ret = -ENOSPC;
1628                         goto err;
1629                 }
1630                 new_fm->e[0] = tmp_e;
1631         }
1632
1633         down_write(&ubi->work_sem);
1634         down_write(&ubi->fm_eba_sem);
1635         ret = ubi_write_fastmap(ubi, new_fm);
1636         up_write(&ubi->fm_eba_sem);
1637         up_write(&ubi->work_sem);
1638
1639         if (ret)
1640                 goto err;
1641
1642 out_unlock:
1643         up_write(&ubi->fm_protect);
1644         kfree(old_fm);
1645         return ret;
1646
1647 err:
1648         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1649
1650         ret = invalidate_fastmap(ubi);
1651         if (ret < 0) {
1652                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1653                 ubi_ro_mode(ubi);
1654         } else {
1655                 return_fm_pebs(ubi, old_fm);
1656                 return_fm_pebs(ubi, new_fm);
1657                 ret = 0;
1658         }
1659
1660         kfree(new_fm);
1661         goto out_unlock;
1662 }