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 if (vol_id < av->vol_id)
 196                         p = &(*p)->rb_right;
 197                 else
 198                         return ERR_PTR(-EINVAL);
 199         }
 200
 201         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 202         if (!av)
 203                 goto out;
 204
 205         av->highest_lnum = av->leb_count = av->used_ebs = 0;
 206         av->vol_id = vol_id;
 207         av->data_pad = data_pad;
 208         av->last_data_size = last_eb_bytes;
 209         av->compat = 0;
 210         av->vol_type = vol_type;
 211         av->root = RB_ROOT;
 212         if (av->vol_type == UBI_STATIC_VOLUME)
 213                 av->used_ebs = used_ebs;
 214
 215         dbg_bld("found volume (ID %i)", vol_id);
 216
 217         rb_link_node(&av->rb, parent, p);
 218         rb_insert_color(&av->rb, &ai->volumes);
 219
 220 out:
 221         return av;
 222 }
 223
 224 /**
 225  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 226  * from it's original list.
 227  * @ai: ubi_attach_info object
 228  * @aeb: the to be assigned SEB
 229  * @av: target scan volume
 230  */
 231 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 232                              struct ubi_ainf_peb *aeb,
 233                              struct ubi_ainf_volume *av)
 234 {
 235         struct ubi_ainf_peb *tmp_aeb;
 236         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 237
 238         p = &av->root.rb_node;
 239         while (*p) {
 240                 parent = *p;
 241
 242                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 243                 if (aeb->lnum != tmp_aeb->lnum) {
 244                         if (aeb->lnum < tmp_aeb->lnum)
 245                                 p = &(*p)->rb_left;
 246                         else
 247                                 p = &(*p)->rb_right;
 248
 249                         continue;
 250                 } else
 251                         break;
 252         }
 253
 254         list_del(&aeb->u.list);
 255         av->leb_count++;
 256
 257         rb_link_node(&aeb->u.rb, parent, p);
 258         rb_insert_color(&aeb->u.rb, &av->root);
 259 }
 260
 261 /**
 262  * update_vol - inserts or updates a LEB which was found a pool.
 263  * @ubi: the UBI device object
 264  * @ai: attach info object
 265  * @av: the volume this LEB belongs to
 266  * @new_vh: the volume header derived from new_aeb
 267  * @new_aeb: the AEB to be examined
 268  *
 269  * Returns 0 on success, < 0 indicates an internal error.
 270  */
 271 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 272                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 273                       struct ubi_ainf_peb *new_aeb)
 274 {
 275         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 276         struct ubi_ainf_peb *aeb, *victim;
 277         int cmp_res;
 278
 279         while (*p) {
 280                 parent = *p;
 281                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 282
 283                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 284                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 285                                 p = &(*p)->rb_left;
 286                         else
 287                                 p = &(*p)->rb_right;
 288
 289                         continue;
 290                 }
 291
 292                 /* This case can happen if the fastmap gets written
 293                  * because of a volume change (creation, deletion, ..).
 294                  * Then a PEB can be within the persistent EBA and the pool.
 295                  */
 296                 if (aeb->pnum == new_aeb->pnum) {
 297                         ubi_assert(aeb->lnum == new_aeb->lnum);
 298                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 299
 300                         return 0;
 301                 }
 302
 303                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 304                 if (cmp_res < 0)
 305                         return cmp_res;
 306
 307                 /* new_aeb is newer */
 308                 if (cmp_res & 1) {
 309                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 310                                 GFP_KERNEL);
 311                         if (!victim)
 312                                 return -ENOMEM;
 313
 314                         victim->ec = aeb->ec;
 315                         victim->pnum = aeb->pnum;
 316                         list_add_tail(&victim->u.list, &ai->erase);
 317
 318                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 319                                 av->last_data_size =
 320                                         be32_to_cpu(new_vh->data_size);
 321
 322                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 323                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 324
 325                         aeb->ec = new_aeb->ec;
 326                         aeb->pnum = new_aeb->pnum;
 327                         aeb->copy_flag = new_vh->copy_flag;
 328                         aeb->scrub = new_aeb->scrub;
 329                         aeb->sqnum = new_aeb->sqnum;
 330                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 331
 332                 /* new_aeb is older */
 333                 } else {
 334                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 335                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 336                         list_add_tail(&new_aeb->u.list, &ai->erase);
 337                 }
 338
 339                 return 0;
 340         }
 341         /* This LEB is new, let's add it to the volume */
 342
 343         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 344                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 345                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 346         }
 347
 348         if (av->vol_type == UBI_STATIC_VOLUME)
 349                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 350
 351         av->leb_count++;
 352
 353         rb_link_node(&new_aeb->u.rb, parent, p);
 354         rb_insert_color(&new_aeb->u.rb, &av->root);
 355
 356         return 0;
 357 }
 358
 359 /**
 360  * process_pool_aeb - we found a non-empty PEB in a pool.
 361  * @ubi: UBI device object
 362  * @ai: attach info object
 363  * @new_vh: the volume header derived from new_aeb
 364  * @new_aeb: the AEB to be examined
 365  *
 366  * Returns 0 on success, < 0 indicates an internal error.
 367  */
 368 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 369                             struct ubi_vid_hdr *new_vh,
 370                             struct ubi_ainf_peb *new_aeb)
 371 {
 372         struct ubi_ainf_volume *av, *tmp_av = NULL;
 373         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 374         int found = 0;
 375
 376         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 377                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 378                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 379
 380                 return 0;
 381         }
 382
 383         /* Find the volume this SEB belongs to */
 384         while (*p) {
 385                 parent = *p;
 386                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 387
 388                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 389                         p = &(*p)->rb_left;
 390                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 391                         p = &(*p)->rb_right;
 392                 else {
 393                         found = 1;
 394                         break;
 395                 }
 396         }
 397
 398         if (found)
 399                 av = tmp_av;
 400         else {
 401                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 402                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 403                 return UBI_BAD_FASTMAP;
 404         }
 405
 406         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 407
 408         return update_vol(ubi, ai, av, new_vh, new_aeb);
 409 }
 410
 411 /**
 412  * unmap_peb - unmap a PEB.
 413  * If fastmap detects a free PEB in the pool it has to check whether
 414  * this PEB has been unmapped after writing the fastmap.
 415  *
 416  * @ai: UBI attach info object
 417  * @pnum: The PEB to be unmapped
 418  */
 419 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 420 {
 421         struct ubi_ainf_volume *av;
 422         struct rb_node *node, *node2;
 423         struct ubi_ainf_peb *aeb;
 424
 425         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 426                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 427
 428                 for (node2 = rb_first(&av->root); node2;
 429                      node2 = rb_next(node2)) {
 430                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 431                         if (aeb->pnum == pnum) {
 432                                 rb_erase(&aeb->u.rb, &av->root);
 433                                 av->leb_count--;
 434                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 435                                 return;
 436                         }
 437                 }
 438         }
 439 }
 440
 441 /**
 442  * scan_pool - scans a pool for changed (no longer empty PEBs).
 443  * @ubi: UBI device object
 444  * @ai: attach info object
 445  * @pebs: an array of all PEB numbers in the to be scanned pool
 446  * @pool_size: size of the pool (number of entries in @pebs)
 447  * @max_sqnum: pointer to the maximal sequence number
 448  * @free: list of PEBs which are most likely free (and go into @ai->free)
 449  *
 450  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 451  * < 0 indicates an internal error.
 452  */
 453 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 454                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 455                      struct list_head *free)
 456 {
 457         struct ubi_vid_hdr *vh;
 458         struct ubi_ec_hdr *ech;
 459         struct ubi_ainf_peb *new_aeb;
 460         int i, pnum, err, ret = 0;
 461
 462         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 463         if (!ech)
 464                 return -ENOMEM;
 465
 466         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 467         if (!vh) {
 468                 kfree(ech);
 469                 return -ENOMEM;
 470         }
 471
 472         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 473
 474         /*
 475          * Now scan all PEBs in the pool to find changes which have been made
 476          * after the creation of the fastmap
 477          */
 478         for (i = 0; i < pool_size; i++) {
 479                 int scrub = 0;
 480                 int image_seq;
 481
 482                 pnum = be32_to_cpu(pebs[i]);
 483
 484                 if (ubi_io_is_bad(ubi, pnum)) {
 485                         ubi_err(ubi, "bad PEB in fastmap pool!");
 486                         ret = UBI_BAD_FASTMAP;
 487                         goto out;
 488                 }
 489
 490                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 491                 if (err && err != UBI_IO_BITFLIPS) {
 492                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 493                                 pnum, err);
 494                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 495                         goto out;
 496                 } else if (err == UBI_IO_BITFLIPS)
 497                         scrub = 1;
 498
 499                 /*
 500                  * Older UBI implementations have image_seq set to zero, so
 501                  * we shouldn't fail if image_seq == 0.
 502                  */
 503                 image_seq = be32_to_cpu(ech->image_seq);
 504
 505                 if (image_seq && (image_seq != ubi->image_seq)) {
 506                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 507                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 508                         ret = UBI_BAD_FASTMAP;
 509                         goto out;
 510                 }
 511
 512                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 513                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 514                         unsigned long long ec = be64_to_cpu(ech->ec);
 515                         unmap_peb(ai, pnum);
 516                         dbg_bld("Adding PEB to free: %i", pnum);
 517
 518                         if (err == UBI_IO_FF_BITFLIPS)
 519                                 scrub = 1;
 520
 521                         add_aeb(ai, free, pnum, ec, scrub);
 522                         continue;
 523                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 524                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 525
 526                         if (err == UBI_IO_BITFLIPS)
 527                                 scrub = 1;
 528
 529                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 530                                                    GFP_KERNEL);
 531                         if (!new_aeb) {
 532                                 ret = -ENOMEM;
 533                                 goto out;
 534                         }
 535
 536                         new_aeb->ec = be64_to_cpu(ech->ec);
 537                         new_aeb->pnum = pnum;
 538                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 539                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 540                         new_aeb->copy_flag = vh->copy_flag;
 541                         new_aeb->scrub = scrub;
 542
 543                         if (*max_sqnum < new_aeb->sqnum)
 544                                 *max_sqnum = new_aeb->sqnum;
 545
 546                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 547                         if (err) {
 548                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 549                                 goto out;
 550                         }
 551                 } else {
 552                         /* We are paranoid and fall back to scanning mode */
 553                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 554                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 555                         goto out;
 556                 }
 557
 558         }
 559
 560 out:
 561         ubi_free_vid_hdr(ubi, vh);
 562         kfree(ech);
 563         return ret;
 564 }
 565
 566 /**
 567  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 568  * @ai: The UBI attach info object
 569  */
 570 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 571 {
 572         struct ubi_ainf_peb *aeb;
 573         struct ubi_ainf_volume *av;
 574         struct rb_node *rb1, *rb2;
 575         int n = 0;
 576
 577         list_for_each_entry(aeb, &ai->erase, u.list)
 578                 n++;
 579
 580         list_for_each_entry(aeb, &ai->free, u.list)
 581                 n++;
 582
 583          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 584                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 585                         n++;
 586
 587         return n;
 588 }
 589
 590 /**
 591  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 592  * @ubi: UBI device object
 593  * @ai: UBI attach info object
 594  * @fm: the fastmap to be attached
 595  *
 596  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 597  * < 0 indicates an internal error.
 598  */
 599 static int ubi_attach_fastmap(struct ubi_device *ubi,
 600                               struct ubi_attach_info *ai,
 601                               struct ubi_fastmap_layout *fm)
 602 {
 603         struct list_head used, free;
 604         struct ubi_ainf_volume *av;
 605         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 606         struct ubi_fm_sb *fmsb;
 607         struct ubi_fm_hdr *fmhdr;
 608         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 609         struct ubi_fm_ec *fmec;
 610         struct ubi_fm_volhdr *fmvhdr;
 611         struct ubi_fm_eba *fm_eba;
 612         int ret, i, j, pool_size, wl_pool_size;
 613         size_t fm_pos = 0, fm_size = ubi->fm_size;
 614         unsigned long long max_sqnum = 0;
 615         void *fm_raw = ubi->fm_buf;
 616
 617         INIT_LIST_HEAD(&used);
 618         INIT_LIST_HEAD(&free);
 619         ai->min_ec = UBI_MAX_ERASECOUNTER;
 620
 621         fmsb = (struct ubi_fm_sb *)(fm_raw);
 622         ai->max_sqnum = fmsb->sqnum;
 623         fm_pos += sizeof(struct ubi_fm_sb);
 624         if (fm_pos >= fm_size)
 625                 goto fail_bad;
 626
 627         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 628         fm_pos += sizeof(*fmhdr);
 629         if (fm_pos >= fm_size)
 630                 goto fail_bad;
 631
 632         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 633                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 634                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 635                 goto fail_bad;
 636         }
 637
 638         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 639         fm_pos += sizeof(*fmpl);
 640         if (fm_pos >= fm_size)
 641                 goto fail_bad;
 642         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 643                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 644                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 645                 goto fail_bad;
 646         }
 647
 648         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 649         fm_pos += sizeof(*fmpl_wl);
 650         if (fm_pos >= fm_size)
 651                 goto fail_bad;
 652         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 653                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 654                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 655                 goto fail_bad;
 656         }
 657
 658         pool_size = be16_to_cpu(fmpl->size);
 659         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 660         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 661         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 662
 663         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 664                 ubi_err(ubi, "bad pool size: %i", pool_size);
 665                 goto fail_bad;
 666         }
 667
 668         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 669                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 670                 goto fail_bad;
 671         }
 672
 673
 674         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 675             fm->max_pool_size < 0) {
 676                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 677                 goto fail_bad;
 678         }
 679
 680         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 681             fm->max_wl_pool_size < 0) {
 682                 ubi_err(ubi, "bad maximal WL pool size: %i",
 683                         fm->max_wl_pool_size);
 684                 goto fail_bad;
 685         }
 686
 687         /* read EC values from free list */
 688         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 689                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 690                 fm_pos += sizeof(*fmec);
 691                 if (fm_pos >= fm_size)
 692                         goto fail_bad;
 693
 694                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 695                         be32_to_cpu(fmec->ec), 0);
 696         }
 697
 698         /* read EC values from used list */
 699         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 700                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 701                 fm_pos += sizeof(*fmec);
 702                 if (fm_pos >= fm_size)
 703                         goto fail_bad;
 704
 705                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 706                         be32_to_cpu(fmec->ec), 0);
 707         }
 708
 709         /* read EC values from scrub list */
 710         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 711                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 712                 fm_pos += sizeof(*fmec);
 713                 if (fm_pos >= fm_size)
 714                         goto fail_bad;
 715
 716                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 717                         be32_to_cpu(fmec->ec), 1);
 718         }
 719
 720         /* read EC values from erase list */
 721         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 722                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 723                 fm_pos += sizeof(*fmec);
 724                 if (fm_pos >= fm_size)
 725                         goto fail_bad;
 726
 727                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 728                         be32_to_cpu(fmec->ec), 1);
 729         }
 730
 731         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 732         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 733
 734         /* Iterate over all volumes and read their EBA table */
 735         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 736                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 737                 fm_pos += sizeof(*fmvhdr);
 738                 if (fm_pos >= fm_size)
 739                         goto fail_bad;
 740
 741                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 742                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 743                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 744                         goto fail_bad;
 745                 }
 746
 747                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 748                              be32_to_cpu(fmvhdr->used_ebs),
 749                              be32_to_cpu(fmvhdr->data_pad),
 750                              fmvhdr->vol_type,
 751                              be32_to_cpu(fmvhdr->last_eb_bytes));
 752
 753                 if (IS_ERR(av)) {
 754                         if (PTR_ERR(av) == -EEXIST)
 755                                 ubi_err(ubi, "volume (ID %i) already exists",
 756                                         fmvhdr->vol_id);
 757
 758                         goto fail_bad;
 759                 }
 760
 761                 ai->vols_found++;
 762                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 763                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 764
 765                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 766                 fm_pos += sizeof(*fm_eba);
 767                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 768                 if (fm_pos >= fm_size)
 769                         goto fail_bad;
 770
 771                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 772                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 773                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 774                         goto fail_bad;
 775                 }
 776
 777                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 778                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 779
 780                         if (pnum < 0)
 781                                 continue;
 782
 783                         aeb = NULL;
 784                         list_for_each_entry(tmp_aeb, &used, u.list) {
 785                                 if (tmp_aeb->pnum == pnum) {
 786                                         aeb = tmp_aeb;
 787                                         break;
 788                                 }
 789                         }
 790
 791                         if (!aeb) {
 792                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 793                                 goto fail_bad;
 794                         }
 795
 796                         aeb->lnum = j;
 797
 798                         if (av->highest_lnum <= aeb->lnum)
 799                                 av->highest_lnum = aeb->lnum;
 800
 801                         assign_aeb_to_av(ai, aeb, av);
 802
 803                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 804                                 aeb->pnum, aeb->lnum, av->vol_id);
 805                 }
 806         }
 807
 808         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 809         if (ret)
 810                 goto fail;
 811
 812         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 813         if (ret)
 814                 goto fail;
 815
 816         if (max_sqnum > ai->max_sqnum)
 817                 ai->max_sqnum = max_sqnum;
 818
 819         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 820                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 821
 822         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 823                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 824
 825         ubi_assert(list_empty(&free));
 826
 827         /*
 828          * If fastmap is leaking PEBs (must not happen), raise a
 829          * fat warning and fall back to scanning mode.
 830          * We do this here because in ubi_wl_init() it's too late
 831          * and we cannot fall back to scanning.
 832          */
 833         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 834                     ai->bad_peb_count - fm->used_blocks))
 835                 goto fail_bad;
 836
 837         return 0;
 838
 839 fail_bad:
 840         ret = UBI_BAD_FASTMAP;
 841 fail:
 842         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 843                 list_del(&tmp_aeb->u.list);
 844                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 845         }
 846         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 847                 list_del(&tmp_aeb->u.list);
 848                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 849         }
 850
 851         return ret;
 852 }
 853
 854 /**
 855  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 856  * @ai: UBI attach info to be filled
 857  */
 858 static int find_fm_anchor(struct ubi_attach_info *ai)
 859 {
 860         int ret = -1;
 861         struct ubi_ainf_peb *aeb;
 862         unsigned long long max_sqnum = 0;
 863
 864         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 865                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 866                         max_sqnum = aeb->sqnum;
 867                         ret = aeb->pnum;
 868                 }
 869         }
 870
 871         return ret;
 872 }
 873
 874 /**
 875  * ubi_scan_fastmap - scan the fastmap.
 876  * @ubi: UBI device object
 877  * @ai: UBI attach info to be filled
 878  * @scan_ai: UBI attach info from the first 64 PEBs,
 879  *           used to find the most recent Fastmap data structure
 880  *
 881  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 882  * UBI_BAD_FASTMAP if one was found but is not usable.
 883  * < 0 indicates an internal error.
 884  */
 885 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 886                      struct ubi_attach_info *scan_ai)
 887 {
 888         struct ubi_fm_sb *fmsb, *fmsb2;
 889         struct ubi_vid_hdr *vh;
 890         struct ubi_ec_hdr *ech;
 891         struct ubi_fastmap_layout *fm;
 892         struct ubi_ainf_peb *tmp_aeb, *aeb;
 893         int i, used_blocks, pnum, fm_anchor, ret = 0;
 894         size_t fm_size;
 895         __be32 crc, tmp_crc;
 896         unsigned long long sqnum = 0;
 897
 898         fm_anchor = find_fm_anchor(scan_ai);
 899         if (fm_anchor < 0)
 900                 return UBI_NO_FASTMAP;
 901
 902         /* Move all (possible) fastmap blocks into our new attach structure. */
 903         list_for_each_entry_safe(aeb, tmp_aeb, &scan_ai->fastmap, u.list)
 904                 list_move_tail(&aeb->u.list, &ai->fastmap);
 905
 906         down_write(&ubi->fm_protect);
 907         memset(ubi->fm_buf, 0, ubi->fm_size);
 908
 909         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 910         if (!fmsb) {
 911                 ret = -ENOMEM;
 912                 goto out;
 913         }
 914
 915         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 916         if (!fm) {
 917                 ret = -ENOMEM;
 918                 kfree(fmsb);
 919                 goto out;
 920         }
 921
 922         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 923         if (ret && ret != UBI_IO_BITFLIPS)
 924                 goto free_fm_sb;
 925         else if (ret == UBI_IO_BITFLIPS)
 926                 fm->to_be_tortured[0] = 1;
 927
 928         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 929                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 930                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 931                 ret = UBI_BAD_FASTMAP;
 932                 goto free_fm_sb;
 933         }
 934
 935         if (fmsb->version != UBI_FM_FMT_VERSION) {
 936                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 937                         fmsb->version, UBI_FM_FMT_VERSION);
 938                 ret = UBI_BAD_FASTMAP;
 939                 goto free_fm_sb;
 940         }
 941
 942         used_blocks = be32_to_cpu(fmsb->used_blocks);
 943         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 944                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 945                         used_blocks);
 946                 ret = UBI_BAD_FASTMAP;
 947                 goto free_fm_sb;
 948         }
 949
 950         fm_size = ubi->leb_size * used_blocks;
 951         if (fm_size != ubi->fm_size) {
 952                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 953                         fm_size, ubi->fm_size);
 954                 ret = UBI_BAD_FASTMAP;
 955                 goto free_fm_sb;
 956         }
 957
 958         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 959         if (!ech) {
 960                 ret = -ENOMEM;
 961                 goto free_fm_sb;
 962         }
 963
 964         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 965         if (!vh) {
 966                 ret = -ENOMEM;
 967                 goto free_hdr;
 968         }
 969
 970         for (i = 0; i < used_blocks; i++) {
 971                 int image_seq;
 972
 973                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 974
 975                 if (ubi_io_is_bad(ubi, pnum)) {
 976                         ret = UBI_BAD_FASTMAP;
 977                         goto free_hdr;
 978                 }
 979
 980                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 981                 if (ret && ret != UBI_IO_BITFLIPS) {
 982                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 983                                 i, pnum);
 984                         if (ret > 0)
 985                                 ret = UBI_BAD_FASTMAP;
 986                         goto free_hdr;
 987                 } else if (ret == UBI_IO_BITFLIPS)
 988                         fm->to_be_tortured[i] = 1;
 989
 990                 image_seq = be32_to_cpu(ech->image_seq);
 991                 if (!ubi->image_seq)
 992                         ubi->image_seq = image_seq;
 993
 994                 /*
 995                  * Older UBI implementations have image_seq set to zero, so
 996                  * we shouldn't fail if image_seq == 0.
 997                  */
 998                 if (image_seq && (image_seq != ubi->image_seq)) {
 999                         ubi_err(ubi, "wrong image seq:%d instead of %d",
1000                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
1001                         ret = UBI_BAD_FASTMAP;
1002                         goto free_hdr;
1003                 }
1004
1005                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
1006                 if (ret && ret != UBI_IO_BITFLIPS) {
1007                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1008                                 i, pnum);
1009                         goto free_hdr;
1010                 }
1011
1012                 if (i == 0) {
1013                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1014                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1015                                         be32_to_cpu(vh->vol_id),
1016                                         UBI_FM_SB_VOLUME_ID);
1017                                 ret = UBI_BAD_FASTMAP;
1018                                 goto free_hdr;
1019                         }
1020                 } else {
1021                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1022                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1023                                         be32_to_cpu(vh->vol_id),
1024                                         UBI_FM_DATA_VOLUME_ID);
1025                                 ret = UBI_BAD_FASTMAP;
1026                                 goto free_hdr;
1027                         }
1028                 }
1029
1030                 if (sqnum < be64_to_cpu(vh->sqnum))
1031                         sqnum = be64_to_cpu(vh->sqnum);
1032
1033                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1034                                   ubi->leb_start, ubi->leb_size);
1035                 if (ret && ret != UBI_IO_BITFLIPS) {
1036                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1037                                 "err: %i)", i, pnum, ret);
1038                         goto free_hdr;
1039                 }
1040         }
1041
1042         kfree(fmsb);
1043         fmsb = NULL;
1044
1045         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1046         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1047         fmsb2->data_crc = 0;
1048         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1049         if (crc != tmp_crc) {
1050                 ubi_err(ubi, "fastmap data CRC is invalid");
1051                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1052                         tmp_crc, crc);
1053                 ret = UBI_BAD_FASTMAP;
1054                 goto free_hdr;
1055         }
1056
1057         fmsb2->sqnum = sqnum;
1058
1059         fm->used_blocks = used_blocks;
1060
1061         ret = ubi_attach_fastmap(ubi, ai, fm);
1062         if (ret) {
1063                 if (ret > 0)
1064                         ret = UBI_BAD_FASTMAP;
1065                 goto free_hdr;
1066         }
1067
1068         for (i = 0; i < used_blocks; i++) {
1069                 struct ubi_wl_entry *e;
1070
1071                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1072                 if (!e) {
1073                         while (i--)
1074                                 kfree(fm->e[i]);
1075
1076                         ret = -ENOMEM;
1077                         goto free_hdr;
1078                 }
1079
1080                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1081                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1082                 fm->e[i] = e;
1083         }
1084
1085         ubi->fm = fm;
1086         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1087         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1088         ubi_msg(ubi, "attached by fastmap");
1089         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1090         ubi_msg(ubi, "fastmap WL pool size: %d",
1091                 ubi->fm_wl_pool.max_size);
1092         ubi->fm_disabled = 0;
1093         ubi->fast_attach = 1;
1094
1095         ubi_free_vid_hdr(ubi, vh);
1096         kfree(ech);
1097 out:
1098         up_write(&ubi->fm_protect);
1099         if (ret == UBI_BAD_FASTMAP)
1100                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1101         return ret;
1102
1103 free_hdr:
1104         ubi_free_vid_hdr(ubi, vh);
1105         kfree(ech);
1106 free_fm_sb:
1107         kfree(fmsb);
1108         kfree(fm);
1109         goto out;
1110 }
1111
1112 /**
1113  * ubi_write_fastmap - writes a fastmap.
1114  * @ubi: UBI device object
1115  * @new_fm: the to be written fastmap
1116  *
1117  * Returns 0 on success, < 0 indicates an internal error.
1118  */
1119 static int ubi_write_fastmap(struct ubi_device *ubi,
1120                              struct ubi_fastmap_layout *new_fm)
1121 {
1122         size_t fm_pos = 0;
1123         void *fm_raw;
1124         struct ubi_fm_sb *fmsb;
1125         struct ubi_fm_hdr *fmh;
1126         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1127         struct ubi_fm_ec *fec;
1128         struct ubi_fm_volhdr *fvh;
1129         struct ubi_fm_eba *feba;
1130         struct ubi_wl_entry *wl_e;
1131         struct ubi_volume *vol;
1132         struct ubi_vid_hdr *avhdr, *dvhdr;
1133         struct ubi_work *ubi_wrk;
1134         struct rb_node *tmp_rb;
1135         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1136         int scrub_peb_count, erase_peb_count;
1137         int *seen_pebs = NULL;
1138
1139         fm_raw = ubi->fm_buf;
1140         memset(ubi->fm_buf, 0, ubi->fm_size);
1141
1142         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1143         if (!avhdr) {
1144                 ret = -ENOMEM;
1145                 goto out;
1146         }
1147
1148         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1149         if (!dvhdr) {
1150                 ret = -ENOMEM;
1151                 goto out_kfree;
1152         }
1153
1154         seen_pebs = init_seen(ubi);
1155         if (IS_ERR(seen_pebs)) {
1156                 ret = PTR_ERR(seen_pebs);
1157                 goto out_kfree;
1158         }
1159
1160         spin_lock(&ubi->volumes_lock);
1161         spin_lock(&ubi->wl_lock);
1162
1163         fmsb = (struct ubi_fm_sb *)fm_raw;
1164         fm_pos += sizeof(*fmsb);
1165         ubi_assert(fm_pos <= ubi->fm_size);
1166
1167         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1168         fm_pos += sizeof(*fmh);
1169         ubi_assert(fm_pos <= ubi->fm_size);
1170
1171         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1172         fmsb->version = UBI_FM_FMT_VERSION;
1173         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1174         /* the max sqnum will be filled in while *reading* the fastmap */
1175         fmsb->sqnum = 0;
1176
1177         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1178         free_peb_count = 0;
1179         used_peb_count = 0;
1180         scrub_peb_count = 0;
1181         erase_peb_count = 0;
1182         vol_count = 0;
1183
1184         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1185         fm_pos += sizeof(*fmpl);
1186         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1187         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1188         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1189
1190         for (i = 0; i < ubi->fm_pool.size; i++) {
1191                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1192                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1193         }
1194
1195         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1196         fm_pos += sizeof(*fmpl_wl);
1197         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1198         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1199         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1200
1201         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1202                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1203                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1204         }
1205
1206         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1207                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1208
1209                 fec->pnum = cpu_to_be32(wl_e->pnum);
1210                 set_seen(ubi, wl_e->pnum, seen_pebs);
1211                 fec->ec = cpu_to_be32(wl_e->ec);
1212
1213                 free_peb_count++;
1214                 fm_pos += sizeof(*fec);
1215                 ubi_assert(fm_pos <= ubi->fm_size);
1216         }
1217         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1218
1219         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1220                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1221
1222                 fec->pnum = cpu_to_be32(wl_e->pnum);
1223                 set_seen(ubi, wl_e->pnum, seen_pebs);
1224                 fec->ec = cpu_to_be32(wl_e->ec);
1225
1226                 used_peb_count++;
1227                 fm_pos += sizeof(*fec);
1228                 ubi_assert(fm_pos <= ubi->fm_size);
1229         }
1230
1231         ubi_for_each_protected_peb(ubi, i, wl_e) {
1232                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1233
1234                 fec->pnum = cpu_to_be32(wl_e->pnum);
1235                 set_seen(ubi, wl_e->pnum, seen_pebs);
1236                 fec->ec = cpu_to_be32(wl_e->ec);
1237
1238                 used_peb_count++;
1239                 fm_pos += sizeof(*fec);
1240                 ubi_assert(fm_pos <= ubi->fm_size);
1241         }
1242         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1243
1244         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1245                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1246
1247                 fec->pnum = cpu_to_be32(wl_e->pnum);
1248                 set_seen(ubi, wl_e->pnum, seen_pebs);
1249                 fec->ec = cpu_to_be32(wl_e->ec);
1250
1251                 scrub_peb_count++;
1252                 fm_pos += sizeof(*fec);
1253                 ubi_assert(fm_pos <= ubi->fm_size);
1254         }
1255         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1256
1257
1258         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1259                 if (ubi_is_erase_work(ubi_wrk)) {
1260                         wl_e = ubi_wrk->e;
1261                         ubi_assert(wl_e);
1262
1263                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1264
1265                         fec->pnum = cpu_to_be32(wl_e->pnum);
1266                         set_seen(ubi, wl_e->pnum, seen_pebs);
1267                         fec->ec = cpu_to_be32(wl_e->ec);
1268
1269                         erase_peb_count++;
1270                         fm_pos += sizeof(*fec);
1271                         ubi_assert(fm_pos <= ubi->fm_size);
1272                 }
1273         }
1274         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1275
1276         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1277                 vol = ubi->volumes[i];
1278
1279                 if (!vol)
1280                         continue;
1281
1282                 vol_count++;
1283
1284                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1285                 fm_pos += sizeof(*fvh);
1286                 ubi_assert(fm_pos <= ubi->fm_size);
1287
1288                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1289                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1290                 fvh->vol_type = vol->vol_type;
1291                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1292                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1293                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1294
1295                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1296                         vol->vol_type == UBI_STATIC_VOLUME);
1297
1298                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1299                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1300                 ubi_assert(fm_pos <= ubi->fm_size);
1301
1302                 for (j = 0; j < vol->reserved_pebs; j++)
1303                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1304
1305                 feba->reserved_pebs = cpu_to_be32(j);
1306                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1307         }
1308         fmh->vol_count = cpu_to_be32(vol_count);
1309         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1310
1311         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1312         avhdr->lnum = 0;
1313
1314         spin_unlock(&ubi->wl_lock);
1315         spin_unlock(&ubi->volumes_lock);
1316
1317         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1318         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1319         if (ret) {
1320                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1321                 goto out_kfree;
1322         }
1323
1324         for (i = 0; i < new_fm->used_blocks; i++) {
1325                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1326                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1327                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1328         }
1329
1330         fmsb->data_crc = 0;
1331         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1332                                            ubi->fm_size));
1333
1334         for (i = 1; i < new_fm->used_blocks; i++) {
1335                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1336                 dvhdr->lnum = cpu_to_be32(i);
1337                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1338                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1339                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1340                 if (ret) {
1341                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1342                                 new_fm->e[i]->pnum);
1343                         goto out_kfree;
1344                 }
1345         }
1346
1347         for (i = 0; i < new_fm->used_blocks; i++) {
1348                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1349                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1350                 if (ret) {
1351                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1352                                 new_fm->e[i]->pnum);
1353                         goto out_kfree;
1354                 }
1355         }
1356
1357         ubi_assert(new_fm);
1358         ubi->fm = new_fm;
1359
1360         ret = self_check_seen(ubi, seen_pebs);
1361         dbg_bld("fastmap written!");
1362
1363 out_kfree:
1364         ubi_free_vid_hdr(ubi, avhdr);
1365         ubi_free_vid_hdr(ubi, dvhdr);
1366         free_seen(seen_pebs);
1367 out:
1368         return ret;
1369 }
1370
1371 /**
1372  * erase_block - Manually erase a PEB.
1373  * @ubi: UBI device object
1374  * @pnum: PEB to be erased
1375  *
1376  * Returns the new EC value on success, < 0 indicates an internal error.
1377  */
1378 static int erase_block(struct ubi_device *ubi, int pnum)
1379 {
1380         int ret;
1381         struct ubi_ec_hdr *ec_hdr;
1382         long long ec;
1383
1384         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1385         if (!ec_hdr)
1386                 return -ENOMEM;
1387
1388         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1389         if (ret < 0)
1390                 goto out;
1391         else if (ret && ret != UBI_IO_BITFLIPS) {
1392                 ret = -EINVAL;
1393                 goto out;
1394         }
1395
1396         ret = ubi_io_sync_erase(ubi, pnum, 0);
1397         if (ret < 0)
1398                 goto out;
1399
1400         ec = be64_to_cpu(ec_hdr->ec);
1401         ec += ret;
1402         if (ec > UBI_MAX_ERASECOUNTER) {
1403                 ret = -EINVAL;
1404                 goto out;
1405         }
1406
1407         ec_hdr->ec = cpu_to_be64(ec);
1408         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1409         if (ret < 0)
1410                 goto out;
1411
1412         ret = ec;
1413 out:
1414         kfree(ec_hdr);
1415         return ret;
1416 }
1417
1418 /**
1419  * invalidate_fastmap - destroys a fastmap.
1420  * @ubi: UBI device object
1421  *
1422  * This function ensures that upon next UBI attach a full scan
1423  * is issued. We need this if UBI is about to write a new fastmap
1424  * but is unable to do so. In this case we have two options:
1425  * a) Make sure that the current fastmap will not be usued upon
1426  * attach time and contine or b) fall back to RO mode to have the
1427  * current fastmap in a valid state.
1428  * Returns 0 on success, < 0 indicates an internal error.
1429  */
1430 static int invalidate_fastmap(struct ubi_device *ubi)
1431 {
1432         int ret;
1433         struct ubi_fastmap_layout *fm;
1434         struct ubi_wl_entry *e;
1435         struct ubi_vid_hdr *vh = NULL;
1436
1437         if (!ubi->fm)
1438                 return 0;
1439
1440         ubi->fm = NULL;
1441
1442         ret = -ENOMEM;
1443         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1444         if (!fm)
1445                 goto out;
1446
1447         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1448         if (!vh)
1449                 goto out_free_fm;
1450
1451         ret = -ENOSPC;
1452         e = ubi_wl_get_fm_peb(ubi, 1);
1453         if (!e)
1454                 goto out_free_fm;
1455
1456         /*
1457          * Create fake fastmap such that UBI will fall back
1458          * to scanning mode.
1459          */
1460         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1461         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vh);
1462         if (ret < 0) {
1463                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1464                 goto out_free_fm;
1465         }
1466
1467         fm->used_blocks = 1;
1468         fm->e[0] = e;
1469
1470         ubi->fm = fm;
1471
1472 out:
1473         ubi_free_vid_hdr(ubi, vh);
1474         return ret;
1475
1476 out_free_fm:
1477         kfree(fm);
1478         goto out;
1479 }
1480
1481 /**
1482  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1483  * WL sub-system.
1484  * @ubi: UBI device object
1485  * @fm: fastmap layout object
1486  */
1487 static void return_fm_pebs(struct ubi_device *ubi,
1488                            struct ubi_fastmap_layout *fm)
1489 {
1490         int i;
1491
1492         if (!fm)
1493                 return;
1494
1495         for (i = 0; i < fm->used_blocks; i++) {
1496                 if (fm->e[i]) {
1497                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1498                                           fm->to_be_tortured[i]);
1499                         fm->e[i] = NULL;
1500                 }
1501         }
1502 }
1503
1504 /**
1505  * ubi_update_fastmap - will be called by UBI if a volume changes or
1506  * a fastmap pool becomes full.
1507  * @ubi: UBI device object
1508  *
1509  * Returns 0 on success, < 0 indicates an internal error.
1510  */
1511 int ubi_update_fastmap(struct ubi_device *ubi)
1512 {
1513         int ret, i, j;
1514         struct ubi_fastmap_layout *new_fm, *old_fm;
1515         struct ubi_wl_entry *tmp_e;
1516
1517         down_write(&ubi->fm_protect);
1518         down_write(&ubi->work_sem);
1519         down_write(&ubi->fm_eba_sem);
1520
1521         ubi_refill_pools(ubi);
1522
1523         if (ubi->ro_mode || ubi->fm_disabled) {
1524                 up_write(&ubi->fm_eba_sem);
1525                 up_write(&ubi->work_sem);
1526                 up_write(&ubi->fm_protect);
1527                 return 0;
1528         }
1529
1530         ret = ubi_ensure_anchor_pebs(ubi);
1531         if (ret) {
1532                 up_write(&ubi->fm_eba_sem);
1533                 up_write(&ubi->work_sem);
1534                 up_write(&ubi->fm_protect);
1535                 return ret;
1536         }
1537
1538         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1539         if (!new_fm) {
1540                 up_write(&ubi->fm_eba_sem);
1541                 up_write(&ubi->work_sem);
1542                 up_write(&ubi->fm_protect);
1543                 return -ENOMEM;
1544         }
1545
1546         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1547         old_fm = ubi->fm;
1548         ubi->fm = NULL;
1549
1550         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1551                 ubi_err(ubi, "fastmap too large");
1552                 ret = -ENOSPC;
1553                 goto err;
1554         }
1555
1556         for (i = 1; i < new_fm->used_blocks; i++) {
1557                 spin_lock(&ubi->wl_lock);
1558                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1559                 spin_unlock(&ubi->wl_lock);
1560
1561                 if (!tmp_e) {
1562                         if (old_fm && old_fm->e[i]) {
1563                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1564                                 if (ret < 0) {
1565                                         ubi_err(ubi, "could not erase old fastmap PEB");
1566
1567                                         for (j = 1; j < i; j++) {
1568                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1569                                                                   j, 0);
1570                                                 new_fm->e[j] = NULL;
1571                                         }
1572                                         goto err;
1573                                 }
1574                                 new_fm->e[i] = old_fm->e[i];
1575                                 old_fm->e[i] = NULL;
1576                         } else {
1577                                 ubi_err(ubi, "could not get any free erase block");
1578
1579                                 for (j = 1; j < i; j++) {
1580                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1581                                         new_fm->e[j] = NULL;
1582                                 }
1583
1584                                 ret = -ENOSPC;
1585                                 goto err;
1586                         }
1587                 } else {
1588                         new_fm->e[i] = tmp_e;
1589
1590                         if (old_fm && old_fm->e[i]) {
1591                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1592                                                   old_fm->to_be_tortured[i]);
1593                                 old_fm->e[i] = NULL;
1594                         }
1595                 }
1596         }
1597
1598         /* Old fastmap is larger than the new one */
1599         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1600                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1601                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1602                                           old_fm->to_be_tortured[i]);
1603                         old_fm->e[i] = NULL;
1604                 }
1605         }
1606
1607         spin_lock(&ubi->wl_lock);
1608         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1609         spin_unlock(&ubi->wl_lock);
1610
1611         if (old_fm) {
1612                 /* no fresh anchor PEB was found, reuse the old one */
1613                 if (!tmp_e) {
1614                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1615                         if (ret < 0) {
1616                                 ubi_err(ubi, "could not erase old anchor PEB");
1617
1618                                 for (i = 1; i < new_fm->used_blocks; i++) {
1619                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1620                                                           i, 0);
1621                                         new_fm->e[i] = NULL;
1622                                 }
1623                                 goto err;
1624                         }
1625                         new_fm->e[0] = old_fm->e[0];
1626                         new_fm->e[0]->ec = ret;
1627                         old_fm->e[0] = NULL;
1628                 } else {
1629                         /* we've got a new anchor PEB, return the old one */
1630                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1631                                           old_fm->to_be_tortured[0]);
1632                         new_fm->e[0] = tmp_e;
1633                         old_fm->e[0] = NULL;
1634                 }
1635         } else {
1636                 if (!tmp_e) {
1637                         ubi_err(ubi, "could not find any anchor PEB");
1638
1639                         for (i = 1; i < new_fm->used_blocks; i++) {
1640                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1641                                 new_fm->e[i] = NULL;
1642                         }
1643
1644                         ret = -ENOSPC;
1645                         goto err;
1646                 }
1647                 new_fm->e[0] = tmp_e;
1648         }
1649
1650         ret = ubi_write_fastmap(ubi, new_fm);
1651
1652         if (ret)
1653                 goto err;
1654
1655 out_unlock:
1656         up_write(&ubi->fm_eba_sem);
1657         up_write(&ubi->work_sem);
1658         up_write(&ubi->fm_protect);
1659         kfree(old_fm);
1660         return ret;
1661
1662 err:
1663         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1664
1665         ret = invalidate_fastmap(ubi);
1666         if (ret < 0) {
1667                 ubi_err(ubi, "Unable to invalidiate current fastmap!");
1668                 ubi_ro_mode(ubi);
1669         } else {
1670                 return_fm_pebs(ubi, old_fm);
1671                 return_fm_pebs(ubi, new_fm);
1672                 ret = 0;
1673         }
1674
1675         kfree(new_fm);
1676         goto out_unlock;
1677 }