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 "ubi.h"
  19
  20 /**
  21  * init_seen - allocate memory for used for debugging.
  22  * @ubi: UBI device description object
  23  */
  24 static inline int *init_seen(struct ubi_device *ubi)
  25 {
  26         int *ret;
  27
  28         if (!ubi_dbg_chk_fastmap(ubi))
  29                 return NULL;
  30
  31         ret = kcalloc(ubi->peb_count, sizeof(int), GFP_KERNEL);
  32         if (!ret)
  33                 return ERR_PTR(-ENOMEM);
  34
  35         return ret;
  36 }
  37
  38 /**
  39  * free_seen - free the seen logic integer array.
  40  * @seen: integer array of @ubi->peb_count size
  41  */
  42 static inline void free_seen(int *seen)
  43 {
  44         kfree(seen);
  45 }
  46
  47 /**
  48  * set_seen - mark a PEB as seen.
  49  * @ubi: UBI device description object
  50  * @pnum: The PEB to be makred as seen
  51  * @seen: integer array of @ubi->peb_count size
  52  */
  53 static inline void set_seen(struct ubi_device *ubi, int pnum, int *seen)
  54 {
  55         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  56                 return;
  57
  58         seen[pnum] = 1;
  59 }
  60
  61 /**
  62  * self_check_seen - check whether all PEB have been seen by fastmap.
  63  * @ubi: UBI device description object
  64  * @seen: integer array of @ubi->peb_count size
  65  */
  66 static int self_check_seen(struct ubi_device *ubi, int *seen)
  67 {
  68         int pnum, ret = 0;
  69
  70         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  71                 return 0;
  72
  73         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  74                 if (!seen[pnum] && ubi->lookuptbl[pnum]) {
  75                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  76                         ret = -EINVAL;
  77                 }
  78         }
  79
  80         return ret;
  81 }
  82
  83 /**
  84  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  85  * @ubi: UBI device description object
  86  */
  87 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  88 {
  89         size_t size;
  90
  91         size = sizeof(struct ubi_fm_sb) + \
  92                 sizeof(struct ubi_fm_hdr) + \
  93                 sizeof(struct ubi_fm_scan_pool) + \
  94                 sizeof(struct ubi_fm_scan_pool) + \
  95                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
  96                 (sizeof(struct ubi_fm_eba) + \
  97                 (ubi->peb_count * sizeof(__be32))) + \
  98                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  99         return roundup(size, ubi->leb_size);
 100 }
 101
 102
 103 /**
 104  * new_fm_vhdr - allocate a new volume header for fastmap usage.
 105  * @ubi: UBI device description object
 106  * @vol_id: the VID of the new header
 107  *
 108  * Returns a new struct ubi_vid_hdr on success.
 109  * NULL indicates out of memory.
 110  */
 111 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
 112 {
 113         struct ubi_vid_hdr *new;
 114
 115         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 116         if (!new)
 117                 goto out;
 118
 119         new->vol_type = UBI_VID_DYNAMIC;
 120         new->vol_id = cpu_to_be32(vol_id);
 121
 122         /* UBI implementations without fastmap support have to delete the
 123          * fastmap.
 124          */
 125         new->compat = UBI_COMPAT_DELETE;
 126
 127 out:
 128         return new;
 129 }
 130
 131 /**
 132  * add_aeb - create and add a attach erase block to a given list.
 133  * @ai: UBI attach info object
 134  * @list: the target list
 135  * @pnum: PEB number of the new attach erase block
 136  * @ec: erease counter of the new LEB
 137  * @scrub: scrub this PEB after attaching
 138  *
 139  * Returns 0 on success, < 0 indicates an internal error.
 140  */
 141 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 142                    int pnum, int ec, int scrub)
 143 {
 144         struct ubi_ainf_peb *aeb;
 145
 146         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
 147         if (!aeb)
 148                 return -ENOMEM;
 149
 150         aeb->pnum = pnum;
 151         aeb->ec = ec;
 152         aeb->lnum = -1;
 153         aeb->scrub = scrub;
 154         aeb->copy_flag = aeb->sqnum = 0;
 155
 156         ai->ec_sum += aeb->ec;
 157         ai->ec_count++;
 158
 159         if (ai->max_ec < aeb->ec)
 160                 ai->max_ec = aeb->ec;
 161
 162         if (ai->min_ec > aeb->ec)
 163                 ai->min_ec = aeb->ec;
 164
 165         list_add_tail(&aeb->u.list, list);
 166
 167         return 0;
 168 }
 169
 170 /**
 171  * add_vol - create and add a new volume to ubi_attach_info.
 172  * @ai: ubi_attach_info object
 173  * @vol_id: VID of the new volume
 174  * @used_ebs: number of used EBS
 175  * @data_pad: data padding value of the new volume
 176  * @vol_type: volume type
 177  * @last_eb_bytes: number of bytes in the last LEB
 178  *
 179  * Returns the new struct ubi_ainf_volume on success.
 180  * NULL indicates an error.
 181  */
 182 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 183                                        int used_ebs, int data_pad, u8 vol_type,
 184                                        int last_eb_bytes)
 185 {
 186         struct ubi_ainf_volume *av;
 187         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 188
 189         while (*p) {
 190                 parent = *p;
 191                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 192
 193                 if (vol_id > av->vol_id)
 194                         p = &(*p)->rb_left;
 195                 else
 196                         p = &(*p)->rb_right;
 197         }
 198
 199         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 200         if (!av)
 201                 goto out;
 202
 203         av->highest_lnum = av->leb_count = av->used_ebs = 0;
 204         av->vol_id = vol_id;
 205         av->data_pad = data_pad;
 206         av->last_data_size = last_eb_bytes;
 207         av->compat = 0;
 208         av->vol_type = vol_type;
 209         av->root = RB_ROOT;
 210         if (av->vol_type == UBI_STATIC_VOLUME)
 211                 av->used_ebs = used_ebs;
 212
 213         dbg_bld("found volume (ID %i)", vol_id);
 214
 215         rb_link_node(&av->rb, parent, p);
 216         rb_insert_color(&av->rb, &ai->volumes);
 217
 218 out:
 219         return av;
 220 }
 221
 222 /**
 223  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 224  * from it's original list.
 225  * @ai: ubi_attach_info object
 226  * @aeb: the to be assigned SEB
 227  * @av: target scan volume
 228  */
 229 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 230                              struct ubi_ainf_peb *aeb,
 231                              struct ubi_ainf_volume *av)
 232 {
 233         struct ubi_ainf_peb *tmp_aeb;
 234         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 235
 236         p = &av->root.rb_node;
 237         while (*p) {
 238                 parent = *p;
 239
 240                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 241                 if (aeb->lnum != tmp_aeb->lnum) {
 242                         if (aeb->lnum < tmp_aeb->lnum)
 243                                 p = &(*p)->rb_left;
 244                         else
 245                                 p = &(*p)->rb_right;
 246
 247                         continue;
 248                 } else
 249                         break;
 250         }
 251
 252         list_del(&aeb->u.list);
 253         av->leb_count++;
 254
 255         rb_link_node(&aeb->u.rb, parent, p);
 256         rb_insert_color(&aeb->u.rb, &av->root);
 257 }
 258
 259 /**
 260  * update_vol - inserts or updates a LEB which was found a pool.
 261  * @ubi: the UBI device object
 262  * @ai: attach info object
 263  * @av: the volume this LEB belongs to
 264  * @new_vh: the volume header derived from new_aeb
 265  * @new_aeb: the AEB to be examined
 266  *
 267  * Returns 0 on success, < 0 indicates an internal error.
 268  */
 269 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 270                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 271                       struct ubi_ainf_peb *new_aeb)
 272 {
 273         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 274         struct ubi_ainf_peb *aeb, *victim;
 275         int cmp_res;
 276
 277         while (*p) {
 278                 parent = *p;
 279                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 280
 281                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 282                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 283                                 p = &(*p)->rb_left;
 284                         else
 285                                 p = &(*p)->rb_right;
 286
 287                         continue;
 288                 }
 289
 290                 /* This case can happen if the fastmap gets written
 291                  * because of a volume change (creation, deletion, ..).
 292                  * Then a PEB can be within the persistent EBA and the pool.
 293                  */
 294                 if (aeb->pnum == new_aeb->pnum) {
 295                         ubi_assert(aeb->lnum == new_aeb->lnum);
 296                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 297
 298                         return 0;
 299                 }
 300
 301                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 302                 if (cmp_res < 0)
 303                         return cmp_res;
 304
 305                 /* new_aeb is newer */
 306                 if (cmp_res & 1) {
 307                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 308                                 GFP_KERNEL);
 309                         if (!victim)
 310                                 return -ENOMEM;
 311
 312                         victim->ec = aeb->ec;
 313                         victim->pnum = aeb->pnum;
 314                         list_add_tail(&victim->u.list, &ai->erase);
 315
 316                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 317                                 av->last_data_size = \
 318                                         be32_to_cpu(new_vh->data_size);
 319
 320                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 321                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 322
 323                         aeb->ec = new_aeb->ec;
 324                         aeb->pnum = new_aeb->pnum;
 325                         aeb->copy_flag = new_vh->copy_flag;
 326                         aeb->scrub = new_aeb->scrub;
 327                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 328
 329                 /* new_aeb is older */
 330                 } else {
 331                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 332                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 333                         list_add_tail(&new_aeb->u.list, &ai->erase);
 334                 }
 335
 336                 return 0;
 337         }
 338         /* This LEB is new, let's add it to the volume */
 339
 340         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 341                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 342                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 343         }
 344
 345         if (av->vol_type == UBI_STATIC_VOLUME)
 346                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 347
 348         av->leb_count++;
 349
 350         rb_link_node(&new_aeb->u.rb, parent, p);
 351         rb_insert_color(&new_aeb->u.rb, &av->root);
 352
 353         return 0;
 354 }
 355
 356 /**
 357  * process_pool_aeb - we found a non-empty PEB in a pool.
 358  * @ubi: UBI device object
 359  * @ai: attach info object
 360  * @new_vh: the volume header derived from new_aeb
 361  * @new_aeb: the AEB to be examined
 362  *
 363  * Returns 0 on success, < 0 indicates an internal error.
 364  */
 365 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 366                             struct ubi_vid_hdr *new_vh,
 367                             struct ubi_ainf_peb *new_aeb)
 368 {
 369         struct ubi_ainf_volume *av, *tmp_av = NULL;
 370         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 371         int found = 0;
 372
 373         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 374                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 375                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 376
 377                 return 0;
 378         }
 379
 380         /* Find the volume this SEB belongs to */
 381         while (*p) {
 382                 parent = *p;
 383                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 384
 385                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 386                         p = &(*p)->rb_left;
 387                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 388                         p = &(*p)->rb_right;
 389                 else {
 390                         found = 1;
 391                         break;
 392                 }
 393         }
 394
 395         if (found)
 396                 av = tmp_av;
 397         else {
 398                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 399                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 400                 return UBI_BAD_FASTMAP;
 401         }
 402
 403         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 404
 405         return update_vol(ubi, ai, av, new_vh, new_aeb);
 406 }
 407
 408 /**
 409  * unmap_peb - unmap a PEB.
 410  * If fastmap detects a free PEB in the pool it has to check whether
 411  * this PEB has been unmapped after writing the fastmap.
 412  *
 413  * @ai: UBI attach info object
 414  * @pnum: The PEB to be unmapped
 415  */
 416 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 417 {
 418         struct ubi_ainf_volume *av;
 419         struct rb_node *node, *node2;
 420         struct ubi_ainf_peb *aeb;
 421
 422         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 423                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 424
 425                 for (node2 = rb_first(&av->root); node2;
 426                      node2 = rb_next(node2)) {
 427                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 428                         if (aeb->pnum == pnum) {
 429                                 rb_erase(&aeb->u.rb, &av->root);
 430                                 av->leb_count--;
 431                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 432                                 return;
 433                         }
 434                 }
 435         }
 436 }
 437
 438 /**
 439  * scan_pool - scans a pool for changed (no longer empty PEBs).
 440  * @ubi: UBI device object
 441  * @ai: attach info object
 442  * @pebs: an array of all PEB numbers in the to be scanned pool
 443  * @pool_size: size of the pool (number of entries in @pebs)
 444  * @max_sqnum: pointer to the maximal sequence number
 445  * @free: list of PEBs which are most likely free (and go into @ai->free)
 446  *
 447  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 448  * < 0 indicates an internal error.
 449  */
 450 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 451                      int *pebs, int pool_size, unsigned long long *max_sqnum,
 452                      struct list_head *free)
 453 {
 454         struct ubi_vid_hdr *vh;
 455         struct ubi_ec_hdr *ech;
 456         struct ubi_ainf_peb *new_aeb;
 457         int i, pnum, err, ret = 0;
 458
 459         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 460         if (!ech)
 461                 return -ENOMEM;
 462
 463         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 464         if (!vh) {
 465                 kfree(ech);
 466                 return -ENOMEM;
 467         }
 468
 469         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 470
 471         /*
 472          * Now scan all PEBs in the pool to find changes which have been made
 473          * after the creation of the fastmap
 474          */
 475         for (i = 0; i < pool_size; i++) {
 476                 int scrub = 0;
 477                 int image_seq;
 478
 479                 pnum = be32_to_cpu(pebs[i]);
 480
 481                 if (ubi_io_is_bad(ubi, pnum)) {
 482                         ubi_err(ubi, "bad PEB in fastmap pool!");
 483                         ret = UBI_BAD_FASTMAP;
 484                         goto out;
 485                 }
 486
 487                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 488                 if (err && err != UBI_IO_BITFLIPS) {
 489                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 490                                 pnum, err);
 491                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 492                         goto out;
 493                 } else if (err == UBI_IO_BITFLIPS)
 494                         scrub = 1;
 495
 496                 /*
 497                  * Older UBI implementations have image_seq set to zero, so
 498                  * we shouldn't fail if image_seq == 0.
 499                  */
 500                 image_seq = be32_to_cpu(ech->image_seq);
 501
 502                 if (image_seq && (image_seq != ubi->image_seq)) {
 503                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 504                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 505                         ret = UBI_BAD_FASTMAP;
 506                         goto out;
 507                 }
 508
 509                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 510                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 511                         unsigned long long ec = be64_to_cpu(ech->ec);
 512                         unmap_peb(ai, pnum);
 513                         dbg_bld("Adding PEB to free: %i", pnum);
 514                         if (err == UBI_IO_FF_BITFLIPS)
 515                                 add_aeb(ai, free, pnum, ec, 1);
 516                         else
 517                                 add_aeb(ai, free, pnum, ec, 0);
 518                         continue;
 519                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 520                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 521
 522                         if (err == UBI_IO_BITFLIPS)
 523                                 scrub = 1;
 524
 525                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 526                                                    GFP_KERNEL);
 527                         if (!new_aeb) {
 528                                 ret = -ENOMEM;
 529                                 goto out;
 530                         }
 531
 532                         new_aeb->ec = be64_to_cpu(ech->ec);
 533                         new_aeb->pnum = pnum;
 534                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 535                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 536                         new_aeb->copy_flag = vh->copy_flag;
 537                         new_aeb->scrub = scrub;
 538
 539                         if (*max_sqnum < new_aeb->sqnum)
 540                                 *max_sqnum = new_aeb->sqnum;
 541
 542                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 543                         if (err) {
 544                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 545                                 goto out;
 546                         }
 547                 } else {
 548                         /* We are paranoid and fall back to scanning mode */
 549                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 550                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 551                         goto out;
 552                 }
 553
 554         }
 555
 556 out:
 557         ubi_free_vid_hdr(ubi, vh);
 558         kfree(ech);
 559         return ret;
 560 }
 561
 562 /**
 563  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 564  * @ai: The UBI attach info object
 565  */
 566 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 567 {
 568         struct ubi_ainf_peb *aeb;
 569         struct ubi_ainf_volume *av;
 570         struct rb_node *rb1, *rb2;
 571         int n = 0;
 572
 573         list_for_each_entry(aeb, &ai->erase, u.list)
 574                 n++;
 575
 576         list_for_each_entry(aeb, &ai->free, u.list)
 577                 n++;
 578
 579          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 580                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 581                         n++;
 582
 583         return n;
 584 }
 585
 586 /**
 587  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 588  * @ubi: UBI device object
 589  * @ai: UBI attach info object
 590  * @fm: the fastmap to be attached
 591  *
 592  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 593  * < 0 indicates an internal error.
 594  */
 595 static int ubi_attach_fastmap(struct ubi_device *ubi,
 596                               struct ubi_attach_info *ai,
 597                               struct ubi_fastmap_layout *fm)
 598 {
 599         struct list_head used, free;
 600         struct ubi_ainf_volume *av;
 601         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 602         struct ubi_fm_sb *fmsb;
 603         struct ubi_fm_hdr *fmhdr;
 604         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 605         struct ubi_fm_ec *fmec;
 606         struct ubi_fm_volhdr *fmvhdr;
 607         struct ubi_fm_eba *fm_eba;
 608         int ret, i, j, pool_size, wl_pool_size;
 609         size_t fm_pos = 0, fm_size = ubi->fm_size;
 610         unsigned long long max_sqnum = 0;
 611         void *fm_raw = ubi->fm_buf;
 612
 613         INIT_LIST_HEAD(&used);
 614         INIT_LIST_HEAD(&free);
 615         ai->min_ec = UBI_MAX_ERASECOUNTER;
 616
 617         fmsb = (struct ubi_fm_sb *)(fm_raw);
 618         ai->max_sqnum = fmsb->sqnum;
 619         fm_pos += sizeof(struct ubi_fm_sb);
 620         if (fm_pos >= fm_size)
 621                 goto fail_bad;
 622
 623         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 624         fm_pos += sizeof(*fmhdr);
 625         if (fm_pos >= fm_size)
 626                 goto fail_bad;
 627
 628         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 629                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 630                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 631                 goto fail_bad;
 632         }
 633
 634         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 635         fm_pos += sizeof(*fmpl1);
 636         if (fm_pos >= fm_size)
 637                 goto fail_bad;
 638         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 639                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 640                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 641                 goto fail_bad;
 642         }
 643
 644         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 645         fm_pos += sizeof(*fmpl2);
 646         if (fm_pos >= fm_size)
 647                 goto fail_bad;
 648         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 649                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 650                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 651                 goto fail_bad;
 652         }
 653
 654         pool_size = be16_to_cpu(fmpl1->size);
 655         wl_pool_size = be16_to_cpu(fmpl2->size);
 656         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 657         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 658
 659         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 660                 ubi_err(ubi, "bad pool size: %i", pool_size);
 661                 goto fail_bad;
 662         }
 663
 664         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 665                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 666                 goto fail_bad;
 667         }
 668
 669
 670         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 671             fm->max_pool_size < 0) {
 672                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 673                 goto fail_bad;
 674         }
 675
 676         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 677             fm->max_wl_pool_size < 0) {
 678                 ubi_err(ubi, "bad maximal WL pool size: %i",
 679                         fm->max_wl_pool_size);
 680                 goto fail_bad;
 681         }
 682
 683         /* read EC values from free list */
 684         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 685                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 686                 fm_pos += sizeof(*fmec);
 687                 if (fm_pos >= fm_size)
 688                         goto fail_bad;
 689
 690                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 691                         be32_to_cpu(fmec->ec), 0);
 692         }
 693
 694         /* read EC values from used list */
 695         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 696                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 697                 fm_pos += sizeof(*fmec);
 698                 if (fm_pos >= fm_size)
 699                         goto fail_bad;
 700
 701                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 702                         be32_to_cpu(fmec->ec), 0);
 703         }
 704
 705         /* read EC values from scrub list */
 706         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 707                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 708                 fm_pos += sizeof(*fmec);
 709                 if (fm_pos >= fm_size)
 710                         goto fail_bad;
 711
 712                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 713                         be32_to_cpu(fmec->ec), 1);
 714         }
 715
 716         /* read EC values from erase list */
 717         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 718                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 719                 fm_pos += sizeof(*fmec);
 720                 if (fm_pos >= fm_size)
 721                         goto fail_bad;
 722
 723                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 724                         be32_to_cpu(fmec->ec), 1);
 725         }
 726
 727         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 728         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 729
 730         /* Iterate over all volumes and read their EBA table */
 731         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 732                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 733                 fm_pos += sizeof(*fmvhdr);
 734                 if (fm_pos >= fm_size)
 735                         goto fail_bad;
 736
 737                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 738                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 739                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 740                         goto fail_bad;
 741                 }
 742
 743                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 744                              be32_to_cpu(fmvhdr->used_ebs),
 745                              be32_to_cpu(fmvhdr->data_pad),
 746                              fmvhdr->vol_type,
 747                              be32_to_cpu(fmvhdr->last_eb_bytes));
 748
 749                 if (!av)
 750                         goto fail_bad;
 751
 752                 ai->vols_found++;
 753                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 754                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 755
 756                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 757                 fm_pos += sizeof(*fm_eba);
 758                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 759                 if (fm_pos >= fm_size)
 760                         goto fail_bad;
 761
 762                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 763                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 764                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 765                         goto fail_bad;
 766                 }
 767
 768                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 769                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 770
 771                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 772                                 continue;
 773
 774                         aeb = NULL;
 775                         list_for_each_entry(tmp_aeb, &used, u.list) {
 776                                 if (tmp_aeb->pnum == pnum) {
 777                                         aeb = tmp_aeb;
 778                                         break;
 779                                 }
 780                         }
 781
 782                         if (!aeb) {
 783                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 784                                 goto fail_bad;
 785                         }
 786
 787                         aeb->lnum = j;
 788
 789                         if (av->highest_lnum <= aeb->lnum)
 790                                 av->highest_lnum = aeb->lnum;
 791
 792                         assign_aeb_to_av(ai, aeb, av);
 793
 794                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 795                                 aeb->pnum, aeb->lnum, av->vol_id);
 796                 }
 797         }
 798
 799         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum, &free);
 800         if (ret)
 801                 goto fail;
 802
 803         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum, &free);
 804         if (ret)
 805                 goto fail;
 806
 807         if (max_sqnum > ai->max_sqnum)
 808                 ai->max_sqnum = max_sqnum;
 809
 810         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 811                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 812
 813         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 814                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 815
 816         ubi_assert(list_empty(&free));
 817
 818         /*
 819          * If fastmap is leaking PEBs (must not happen), raise a
 820          * fat warning and fall back to scanning mode.
 821          * We do this here because in ubi_wl_init() it's too late
 822          * and we cannot fall back to scanning.
 823          */
 824         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 825                     ai->bad_peb_count - fm->used_blocks))
 826                 goto fail_bad;
 827
 828         return 0;
 829
 830 fail_bad:
 831         ret = UBI_BAD_FASTMAP;
 832 fail:
 833         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 834                 list_del(&tmp_aeb->u.list);
 835                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 836         }
 837         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 838                 list_del(&tmp_aeb->u.list);
 839                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 840         }
 841
 842         return ret;
 843 }
 844
 845 /**
 846  * ubi_scan_fastmap - scan the fastmap.
 847  * @ubi: UBI device object
 848  * @ai: UBI attach info to be filled
 849  * @fm_anchor: The fastmap starts at this PEB
 850  *
 851  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 852  * UBI_BAD_FASTMAP if one was found but is not usable.
 853  * < 0 indicates an internal error.
 854  */
 855 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 856                      int fm_anchor)
 857 {
 858         struct ubi_fm_sb *fmsb, *fmsb2;
 859         struct ubi_vid_hdr *vh;
 860         struct ubi_ec_hdr *ech;
 861         struct ubi_fastmap_layout *fm;
 862         int i, used_blocks, pnum, ret = 0;
 863         size_t fm_size;
 864         __be32 crc, tmp_crc;
 865         unsigned long long sqnum = 0;
 866
 867         down_write(&ubi->fm_protect);
 868         memset(ubi->fm_buf, 0, ubi->fm_size);
 869
 870         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 871         if (!fmsb) {
 872                 ret = -ENOMEM;
 873                 goto out;
 874         }
 875
 876         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 877         if (!fm) {
 878                 ret = -ENOMEM;
 879                 kfree(fmsb);
 880                 goto out;
 881         }
 882
 883         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 884         if (ret && ret != UBI_IO_BITFLIPS)
 885                 goto free_fm_sb;
 886         else if (ret == UBI_IO_BITFLIPS)
 887                 fm->to_be_tortured[0] = 1;
 888
 889         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 890                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 891                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 892                 ret = UBI_BAD_FASTMAP;
 893                 goto free_fm_sb;
 894         }
 895
 896         if (fmsb->version != UBI_FM_FMT_VERSION) {
 897                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 898                         fmsb->version, UBI_FM_FMT_VERSION);
 899                 ret = UBI_BAD_FASTMAP;
 900                 goto free_fm_sb;
 901         }
 902
 903         used_blocks = be32_to_cpu(fmsb->used_blocks);
 904         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 905                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 906                         used_blocks);
 907                 ret = UBI_BAD_FASTMAP;
 908                 goto free_fm_sb;
 909         }
 910
 911         fm_size = ubi->leb_size * used_blocks;
 912         if (fm_size != ubi->fm_size) {
 913                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 914                         fm_size, ubi->fm_size);
 915                 ret = UBI_BAD_FASTMAP;
 916                 goto free_fm_sb;
 917         }
 918
 919         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 920         if (!ech) {
 921                 ret = -ENOMEM;
 922                 goto free_fm_sb;
 923         }
 924
 925         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 926         if (!vh) {
 927                 ret = -ENOMEM;
 928                 goto free_hdr;
 929         }
 930
 931         for (i = 0; i < used_blocks; i++) {
 932                 int image_seq;
 933
 934                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 935
 936                 if (ubi_io_is_bad(ubi, pnum)) {
 937                         ret = UBI_BAD_FASTMAP;
 938                         goto free_hdr;
 939                 }
 940
 941                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 942                 if (ret && ret != UBI_IO_BITFLIPS) {
 943                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 944                                 i, pnum);
 945                         if (ret > 0)
 946                                 ret = UBI_BAD_FASTMAP;
 947                         goto free_hdr;
 948                 } else if (ret == UBI_IO_BITFLIPS)
 949                         fm->to_be_tortured[i] = 1;
 950
 951                 image_seq = be32_to_cpu(ech->image_seq);
 952                 if (!ubi->image_seq)
 953                         ubi->image_seq = image_seq;
 954
 955                 /*
 956                  * Older UBI implementations have image_seq set to zero, so
 957                  * we shouldn't fail if image_seq == 0.
 958                  */
 959                 if (image_seq && (image_seq != ubi->image_seq)) {
 960                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 961                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 962                         ret = UBI_BAD_FASTMAP;
 963                         goto free_hdr;
 964                 }
 965
 966                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 967                 if (ret && ret != UBI_IO_BITFLIPS) {
 968                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 969                                 i, pnum);
 970                         goto free_hdr;
 971                 }
 972
 973                 if (i == 0) {
 974                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 975                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 976                                         be32_to_cpu(vh->vol_id),
 977                                         UBI_FM_SB_VOLUME_ID);
 978                                 ret = UBI_BAD_FASTMAP;
 979                                 goto free_hdr;
 980                         }
 981                 } else {
 982                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 983                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 984                                         be32_to_cpu(vh->vol_id),
 985                                         UBI_FM_DATA_VOLUME_ID);
 986                                 ret = UBI_BAD_FASTMAP;
 987                                 goto free_hdr;
 988                         }
 989                 }
 990
 991                 if (sqnum < be64_to_cpu(vh->sqnum))
 992                         sqnum = be64_to_cpu(vh->sqnum);
 993
 994                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
 995                                   ubi->leb_start, ubi->leb_size);
 996                 if (ret && ret != UBI_IO_BITFLIPS) {
 997                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
 998                                 "err: %i)", i, pnum, ret);
 999                         goto free_hdr;
1000                 }
1001         }
1002
1003         kfree(fmsb);
1004         fmsb = NULL;
1005
1006         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1007         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1008         fmsb2->data_crc = 0;
1009         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1010         if (crc != tmp_crc) {
1011                 ubi_err(ubi, "fastmap data CRC is invalid");
1012                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1013                         tmp_crc, crc);
1014                 ret = UBI_BAD_FASTMAP;
1015                 goto free_hdr;
1016         }
1017
1018         fmsb2->sqnum = sqnum;
1019
1020         fm->used_blocks = used_blocks;
1021
1022         ret = ubi_attach_fastmap(ubi, ai, fm);
1023         if (ret) {
1024                 if (ret > 0)
1025                         ret = UBI_BAD_FASTMAP;
1026                 goto free_hdr;
1027         }
1028
1029         for (i = 0; i < used_blocks; i++) {
1030                 struct ubi_wl_entry *e;
1031
1032                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1033                 if (!e) {
1034                         while (i--)
1035                                 kfree(fm->e[i]);
1036
1037                         ret = -ENOMEM;
1038                         goto free_hdr;
1039                 }
1040
1041                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1042                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1043                 fm->e[i] = e;
1044         }
1045
1046         ubi->fm = fm;
1047         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1048         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1049         ubi_msg(ubi, "attached by fastmap");
1050         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1051         ubi_msg(ubi, "fastmap WL pool size: %d",
1052                 ubi->fm_wl_pool.max_size);
1053         ubi->fm_disabled = 0;
1054
1055         ubi_free_vid_hdr(ubi, vh);
1056         kfree(ech);
1057 out:
1058         up_write(&ubi->fm_protect);
1059         if (ret == UBI_BAD_FASTMAP)
1060                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1061         return ret;
1062
1063 free_hdr:
1064         ubi_free_vid_hdr(ubi, vh);
1065         kfree(ech);
1066 free_fm_sb:
1067         kfree(fmsb);
1068         kfree(fm);
1069         goto out;
1070 }
1071
1072 /**
1073  * ubi_write_fastmap - writes a fastmap.
1074  * @ubi: UBI device object
1075  * @new_fm: the to be written fastmap
1076  *
1077  * Returns 0 on success, < 0 indicates an internal error.
1078  */
1079 static int ubi_write_fastmap(struct ubi_device *ubi,
1080                              struct ubi_fastmap_layout *new_fm)
1081 {
1082         size_t fm_pos = 0;
1083         void *fm_raw;
1084         struct ubi_fm_sb *fmsb;
1085         struct ubi_fm_hdr *fmh;
1086         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1087         struct ubi_fm_ec *fec;
1088         struct ubi_fm_volhdr *fvh;
1089         struct ubi_fm_eba *feba;
1090         struct rb_node *node;
1091         struct ubi_wl_entry *wl_e;
1092         struct ubi_volume *vol;
1093         struct ubi_vid_hdr *avhdr, *dvhdr;
1094         struct ubi_work *ubi_wrk;
1095         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1096         int scrub_peb_count, erase_peb_count;
1097         int *seen_pebs = NULL;
1098
1099         fm_raw = ubi->fm_buf;
1100         memset(ubi->fm_buf, 0, ubi->fm_size);
1101
1102         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1103         if (!avhdr) {
1104                 ret = -ENOMEM;
1105                 goto out;
1106         }
1107
1108         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1109         if (!dvhdr) {
1110                 ret = -ENOMEM;
1111                 goto out_kfree;
1112         }
1113
1114         seen_pebs = init_seen(ubi);
1115         if (IS_ERR(seen_pebs)) {
1116                 ret = PTR_ERR(seen_pebs);
1117                 goto out_kfree;
1118         }
1119
1120         spin_lock(&ubi->volumes_lock);
1121         spin_lock(&ubi->wl_lock);
1122
1123         fmsb = (struct ubi_fm_sb *)fm_raw;
1124         fm_pos += sizeof(*fmsb);
1125         ubi_assert(fm_pos <= ubi->fm_size);
1126
1127         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1128         fm_pos += sizeof(*fmh);
1129         ubi_assert(fm_pos <= ubi->fm_size);
1130
1131         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1132         fmsb->version = UBI_FM_FMT_VERSION;
1133         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1134         /* the max sqnum will be filled in while *reading* the fastmap */
1135         fmsb->sqnum = 0;
1136
1137         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1138         free_peb_count = 0;
1139         used_peb_count = 0;
1140         scrub_peb_count = 0;
1141         erase_peb_count = 0;
1142         vol_count = 0;
1143
1144         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1145         fm_pos += sizeof(*fmpl1);
1146         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1147         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1148         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1149
1150         for (i = 0; i < ubi->fm_pool.size; i++) {
1151                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1152                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1153         }
1154
1155         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1156         fm_pos += sizeof(*fmpl2);
1157         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1158         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1159         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1160
1161         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1162                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1163                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1164         }
1165
1166         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1167                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1168                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1169
1170                 fec->pnum = cpu_to_be32(wl_e->pnum);
1171                 set_seen(ubi, wl_e->pnum, seen_pebs);
1172                 fec->ec = cpu_to_be32(wl_e->ec);
1173
1174                 free_peb_count++;
1175                 fm_pos += sizeof(*fec);
1176                 ubi_assert(fm_pos <= ubi->fm_size);
1177         }
1178         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1179
1180         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1181                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1182                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1183
1184                 fec->pnum = cpu_to_be32(wl_e->pnum);
1185                 set_seen(ubi, wl_e->pnum, seen_pebs);
1186                 fec->ec = cpu_to_be32(wl_e->ec);
1187
1188                 used_peb_count++;
1189                 fm_pos += sizeof(*fec);
1190                 ubi_assert(fm_pos <= ubi->fm_size);
1191         }
1192
1193         for (i = 0; i < UBI_PROT_QUEUE_LEN; i++) {
1194                 list_for_each_entry(wl_e, &ubi->pq[i], u.list) {
1195                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1196
1197                         fec->pnum = cpu_to_be32(wl_e->pnum);
1198                         fec->ec = cpu_to_be32(wl_e->ec);
1199
1200                         used_peb_count++;
1201                         fm_pos += sizeof(*fec);
1202                         ubi_assert(fm_pos <= ubi->fm_size);
1203                 }
1204         }
1205         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1206
1207         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1208                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1209                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1210
1211                 fec->pnum = cpu_to_be32(wl_e->pnum);
1212                 set_seen(ubi, wl_e->pnum, seen_pebs);
1213                 fec->ec = cpu_to_be32(wl_e->ec);
1214
1215                 scrub_peb_count++;
1216                 fm_pos += sizeof(*fec);
1217                 ubi_assert(fm_pos <= ubi->fm_size);
1218         }
1219         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1220
1221
1222         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1223                 if (ubi_is_erase_work(ubi_wrk)) {
1224                         wl_e = ubi_wrk->e;
1225                         ubi_assert(wl_e);
1226
1227                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1228
1229                         fec->pnum = cpu_to_be32(wl_e->pnum);
1230                         set_seen(ubi, wl_e->pnum, seen_pebs);
1231                         fec->ec = cpu_to_be32(wl_e->ec);
1232
1233                         erase_peb_count++;
1234                         fm_pos += sizeof(*fec);
1235                         ubi_assert(fm_pos <= ubi->fm_size);
1236                 }
1237         }
1238         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1239
1240         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1241                 vol = ubi->volumes[i];
1242
1243                 if (!vol)
1244                         continue;
1245
1246                 vol_count++;
1247
1248                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1249                 fm_pos += sizeof(*fvh);
1250                 ubi_assert(fm_pos <= ubi->fm_size);
1251
1252                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1253                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1254                 fvh->vol_type = vol->vol_type;
1255                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1256                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1257                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1258
1259                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1260                         vol->vol_type == UBI_STATIC_VOLUME);
1261
1262                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1263                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1264                 ubi_assert(fm_pos <= ubi->fm_size);
1265
1266                 for (j = 0; j < vol->reserved_pebs; j++)
1267                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1268
1269                 feba->reserved_pebs = cpu_to_be32(j);
1270                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1271         }
1272         fmh->vol_count = cpu_to_be32(vol_count);
1273         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1274
1275         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1276         avhdr->lnum = 0;
1277
1278         spin_unlock(&ubi->wl_lock);
1279         spin_unlock(&ubi->volumes_lock);
1280
1281         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1282         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1283         if (ret) {
1284                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1285                 goto out_kfree;
1286         }
1287
1288         for (i = 0; i < new_fm->used_blocks; i++) {
1289                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1290                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1291                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1292         }
1293
1294         fmsb->data_crc = 0;
1295         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1296                                            ubi->fm_size));
1297
1298         for (i = 1; i < new_fm->used_blocks; i++) {
1299                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1300                 dvhdr->lnum = cpu_to_be32(i);
1301                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1302                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1303                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1304                 if (ret) {
1305                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1306                                 new_fm->e[i]->pnum);
1307                         goto out_kfree;
1308                 }
1309         }
1310
1311         for (i = 0; i < new_fm->used_blocks; i++) {
1312                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1313                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1314                 if (ret) {
1315                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1316                                 new_fm->e[i]->pnum);
1317                         goto out_kfree;
1318                 }
1319         }
1320
1321         ubi_assert(new_fm);
1322         ubi->fm = new_fm;
1323
1324         ret = self_check_seen(ubi, seen_pebs);
1325         dbg_bld("fastmap written!");
1326
1327 out_kfree:
1328         ubi_free_vid_hdr(ubi, avhdr);
1329         ubi_free_vid_hdr(ubi, dvhdr);
1330         free_seen(seen_pebs);
1331 out:
1332         return ret;
1333 }
1334
1335 /**
1336  * erase_block - Manually erase a PEB.
1337  * @ubi: UBI device object
1338  * @pnum: PEB to be erased
1339  *
1340  * Returns the new EC value on success, < 0 indicates an internal error.
1341  */
1342 static int erase_block(struct ubi_device *ubi, int pnum)
1343 {
1344         int ret;
1345         struct ubi_ec_hdr *ec_hdr;
1346         long long ec;
1347
1348         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1349         if (!ec_hdr)
1350                 return -ENOMEM;
1351
1352         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1353         if (ret < 0)
1354                 goto out;
1355         else if (ret && ret != UBI_IO_BITFLIPS) {
1356                 ret = -EINVAL;
1357                 goto out;
1358         }
1359
1360         ret = ubi_io_sync_erase(ubi, pnum, 0);
1361         if (ret < 0)
1362                 goto out;
1363
1364         ec = be64_to_cpu(ec_hdr->ec);
1365         ec += ret;
1366         if (ec > UBI_MAX_ERASECOUNTER) {
1367                 ret = -EINVAL;
1368                 goto out;
1369         }
1370
1371         ec_hdr->ec = cpu_to_be64(ec);
1372         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1373         if (ret < 0)
1374                 goto out;
1375
1376         ret = ec;
1377 out:
1378         kfree(ec_hdr);
1379         return ret;
1380 }
1381
1382 /**
1383  * invalidate_fastmap - destroys a fastmap.
1384  * @ubi: UBI device object
1385  *
1386  * This function ensures that upon next UBI attach a full scan
1387  * is issued. We need this if UBI is about to write a new fastmap
1388  * but is unable to do so. In this case we have two options:
1389  * a) Make sure that the current fastmap will not be usued upon
1390  * attach time and contine or b) fall back to RO mode to have the
1391  * current fastmap in a valid state.
1392  * Returns 0 on success, < 0 indicates an internal error.
1393  */
1394 static int invalidate_fastmap(struct ubi_device *ubi)
1395 {
1396         int ret;
1397         struct ubi_fastmap_layout *fm;
1398         struct ubi_wl_entry *e;
1399         struct ubi_vid_hdr *vh = NULL;
1400
1401         if (!ubi->fm)
1402                 return 0;
1403
1404         ubi->fm = NULL;
1405
1406         ret = -ENOMEM;
1407         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1408         if (!fm)
1409                 goto out;
1410
1411         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1412         if (!vh)
1413                 goto out_free_fm;
1414
1415         ret = -ENOSPC;
1416         e = ubi_wl_get_fm_peb(ubi, 1);
1417         if (!e)
1418                 goto out_free_fm;
1419
1420         /*
1421          * Create fake fastmap such that UBI will fall back
1422          * to scanning mode.
1423          */
1424         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1425         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1426         if (ret < 0) {
1427                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1428                 goto out_free_fm;
1429         }
1430
1431         fm->used_blocks = 1;
1432         fm->e[0] = e;
1433
1434         ubi->fm = fm;
1435
1436 out:
1437         ubi_free_vid_hdr(ubi, vh);
1438         return ret;
1439
1440 out_free_fm:
1441         kfree(fm);
1442         goto out;
1443 }
1444
1445 /**
1446  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1447  * WL sub-system.
1448  * @ubi: UBI device object
1449  * @fm: fastmap layout object
1450  */
1451 static void return_fm_pebs(struct ubi_device *ubi,
1452                            struct ubi_fastmap_layout *fm)
1453 {
1454         int i;
1455
1456         if (!fm)
1457                 return;
1458
1459         for (i = 0; i < fm->used_blocks; i++) {
1460                 if (fm->e[i]) {
1461                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1462                                           fm->to_be_tortured[i]);
1463                         fm->e[i] = NULL;
1464                 }
1465         }
1466 }
1467
1468 /**
1469  * ubi_update_fastmap - will be called by UBI if a volume changes or
1470  * a fastmap pool becomes full.
1471  * @ubi: UBI device object
1472  *
1473  * Returns 0 on success, < 0 indicates an internal error.
1474  */
1475 int ubi_update_fastmap(struct ubi_device *ubi)
1476 {
1477         int ret, i, j;
1478         struct ubi_fastmap_layout *new_fm, *old_fm;
1479         struct ubi_wl_entry *tmp_e;
1480
1481         down_write(&ubi->fm_protect);
1482
1483         ubi_refill_pools(ubi);
1484
1485         if (ubi->ro_mode || ubi->fm_disabled) {
1486                 up_write(&ubi->fm_protect);
1487                 return 0;
1488         }
1489
1490         ret = ubi_ensure_anchor_pebs(ubi);
1491         if (ret) {
1492                 up_write(&ubi->fm_protect);
1493                 return ret;
1494         }
1495
1496         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1497         if (!new_fm) {
1498                 up_write(&ubi->fm_protect);
1499                 return -ENOMEM;
1500         }
1501
1502         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1503         old_fm = ubi->fm;
1504         ubi->fm = NULL;
1505
1506         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1507                 ubi_err(ubi, "fastmap too large");
1508                 ret = -ENOSPC;
1509                 goto err;
1510         }
1511
1512         for (i = 1; i < new_fm->used_blocks; i++) {
1513                 spin_lock(&ubi->wl_lock);
1514                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1515                 spin_unlock(&ubi->wl_lock);
1516
1517                 if (!tmp_e) {
1518                         if (old_fm && old_fm->e[i]) {
1519                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1520                                 if (ret < 0) {
1521                                         ubi_err(ubi, "could not erase old fastmap PEB");
1522
1523                                         for (j = 1; j < i; j++) {
1524                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1525                                                                   j, 0);
1526                                                 new_fm->e[j] = NULL;
1527                                         }
1528                                         goto err;
1529                                 }
1530                                 new_fm->e[i] = old_fm->e[i];
1531                                 old_fm->e[i] = NULL;
1532                         } else {
1533                                 ubi_err(ubi, "could not get any free erase block");
1534
1535                                 for (j = 1; j < i; j++) {
1536                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1537                                         new_fm->e[j] = NULL;
1538                                 }
1539
1540                                 ret = -ENOSPC;
1541                                 goto err;
1542                         }
1543                 } else {
1544                         new_fm->e[i] = tmp_e;
1545
1546                         if (old_fm && old_fm->e[i]) {
1547                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1548                                                   old_fm->to_be_tortured[i]);
1549                                 old_fm->e[i] = NULL;
1550                         }
1551                 }
1552         }
1553
1554         /* Old fastmap is larger than the new one */
1555         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1556                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1557                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1558                                           old_fm->to_be_tortured[i]);
1559                         old_fm->e[i] = NULL;
1560                 }
1561         }
1562
1563         spin_lock(&ubi->wl_lock);
1564         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1565         spin_unlock(&ubi->wl_lock);
1566
1567         if (old_fm) {
1568                 /* no fresh anchor PEB was found, reuse the old one */
1569                 if (!tmp_e) {
1570                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1571                         if (ret < 0) {
1572                                 ubi_err(ubi, "could not erase old anchor PEB");
1573
1574                                 for (i = 1; i < new_fm->used_blocks; i++) {
1575                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1576                                                           i, 0);
1577                                         new_fm->e[i] = NULL;
1578                                 }
1579                                 goto err;
1580                         }
1581                         new_fm->e[0] = old_fm->e[0];
1582                         new_fm->e[0]->ec = ret;
1583                         old_fm->e[0] = NULL;
1584                 } else {
1585                         /* we've got a new anchor PEB, return the old one */
1586                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1587                                           old_fm->to_be_tortured[0]);
1588                         new_fm->e[0] = tmp_e;
1589                         old_fm->e[0] = NULL;
1590                 }
1591         } else {
1592                 if (!tmp_e) {
1593                         ubi_err(ubi, "could not find any anchor PEB");
1594
1595                         for (i = 1; i < new_fm->used_blocks; i++) {
1596                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1597                                 new_fm->e[i] = NULL;
1598                         }
1599
1600                         ret = -ENOSPC;
1601                         goto err;
1602                 }
1603                 new_fm->e[0] = tmp_e;
1604         }
1605
1606         down_write(&ubi->work_sem);
1607         down_write(&ubi->fm_eba_sem);
1608         ret = ubi_write_fastmap(ubi, new_fm);
1609         up_write(&ubi->fm_eba_sem);
1610         up_write(&ubi->work_sem);
1611
1612         if (ret)
1613                 goto err;
1614
1615 out_unlock:
1616         up_write(&ubi->fm_protect);
1617         kfree(old_fm);
1618         return ret;
1619
1620 err:
1621         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1622
1623         ret = invalidate_fastmap(ubi);
1624         if (ret < 0) {
1625                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1626                 ubi_ro_mode(ubi);
1627         } else {
1628                 return_fm_pebs(ubi, old_fm);
1629                 return_fm_pebs(ubi, new_fm);
1630                 ret = 0;
1631         }
1632
1633         kfree(new_fm);
1634         goto out_unlock;
1635 }