drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Copyright (c) 2014 sigma star gmbh
   4  * Author: Richard Weinberger <richard@nod.at>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/crc32.h>
  18 #include <linux/bitmap.h>
  19 #include "ubi.h"
  20
  21 /**
  22  * init_seen - allocate memory for used for debugging.
  23  * @ubi: UBI device description object
  24  */
  25 static inline unsigned long *init_seen(struct ubi_device *ubi)
  26 {
  27         unsigned long *ret;
  28
  29         if (!ubi_dbg_chk_fastmap(ubi))
  30                 return NULL;
  31
  32         ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  33                       GFP_KERNEL);
  34         if (!ret)
  35                 return ERR_PTR(-ENOMEM);
  36
  37         return ret;
  38 }
  39
  40 /**
  41  * free_seen - free the seen logic integer array.
  42  * @seen: integer array of @ubi->peb_count size
  43  */
  44 static inline void free_seen(unsigned long *seen)
  45 {
  46         kfree(seen);
  47 }
  48
  49 /**
  50  * set_seen - mark a PEB as seen.
  51  * @ubi: UBI device description object
  52  * @pnum: The PEB to be makred as seen
  53  * @seen: integer array of @ubi->peb_count size
  54  */
  55 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  56 {
  57         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  58                 return;
  59
  60         set_bit(pnum, seen);
  61 }
  62
  63 /**
  64  * self_check_seen - check whether all PEB have been seen by fastmap.
  65  * @ubi: UBI device description object
  66  * @seen: integer array of @ubi->peb_count size
  67  */
  68 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  69 {
  70         int pnum, ret = 0;
  71
  72         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  73                 return 0;
  74
  75         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  76                 if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  77                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  78                         ret = -EINVAL;
  79                 }
  80         }
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  87  * @ubi: UBI device description object
  88  */
  89 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  90 {
  91         size_t size;
  92
  93         size = sizeof(struct ubi_fm_sb) +
  94                 sizeof(struct ubi_fm_hdr) +
  95                 sizeof(struct ubi_fm_scan_pool) +
  96                 sizeof(struct ubi_fm_scan_pool) +
  97                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  98                 (sizeof(struct ubi_fm_eba) +
  99                 (ubi->peb_count * sizeof(__be32))) +
 100                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
 101         return roundup(size, ubi->leb_size);
 102 }
 103
 104
 105 /**
 106  * new_fm_vhdr - allocate a new volume header for fastmap usage.
 107  * @ubi: UBI device description object
 108  * @vol_id: the VID of the new header
 109  *
 110  * Returns a new struct ubi_vid_hdr on success.
 111  * NULL indicates out of memory.
 112  */
 113 static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 114 {
 115         struct ubi_vid_io_buf *new;
 116         struct ubi_vid_hdr *vh;
 117
 118         new = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 119         if (!new)
 120                 goto out;
 121
 122         vh = ubi_get_vid_hdr(new);
 123         vh->vol_type = UBI_VID_DYNAMIC;
 124         vh->vol_id = cpu_to_be32(vol_id);
 125
 126         /* UBI implementations without fastmap support have to delete the
 127          * fastmap.
 128          */
 129         vh->compat = UBI_COMPAT_DELETE;
 130
 131 out:
 132         return new;
 133 }
 134
 135 /**
 136  * add_aeb - create and add a attach erase block to a given list.
 137  * @ai: UBI attach info object
 138  * @list: the target list
 139  * @pnum: PEB number of the new attach erase block
 140  * @ec: erease counter of the new LEB
 141  * @scrub: scrub this PEB after attaching
 142  *
 143  * Returns 0 on success, < 0 indicates an internal error.
 144  */
 145 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 146                    int pnum, int ec, int scrub)
 147 {
 148         struct ubi_ainf_peb *aeb;
 149
 150         aeb = ubi_alloc_aeb(ai, pnum, ec);
 151         if (!aeb)
 152                 return -ENOMEM;
 153
 154         aeb->lnum = -1;
 155         aeb->scrub = scrub;
 156         aeb->copy_flag = aeb->sqnum = 0;
 157
 158         ai->ec_sum += aeb->ec;
 159         ai->ec_count++;
 160
 161         if (ai->max_ec < aeb->ec)
 162                 ai->max_ec = aeb->ec;
 163
 164         if (ai->min_ec > aeb->ec)
 165                 ai->min_ec = aeb->ec;
 166
 167         list_add_tail(&aeb->u.list, list);
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * add_vol - create and add a new volume to ubi_attach_info.
 174  * @ai: ubi_attach_info object
 175  * @vol_id: VID of the new volume
 176  * @used_ebs: number of used EBS
 177  * @data_pad: data padding value of the new volume
 178  * @vol_type: volume type
 179  * @last_eb_bytes: number of bytes in the last LEB
 180  *
 181  * Returns the new struct ubi_ainf_volume on success.
 182  * NULL indicates an error.
 183  */
 184 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 185                                        int used_ebs, int data_pad, u8 vol_type,
 186                                        int last_eb_bytes)
 187 {
 188         struct ubi_ainf_volume *av;
 189
 190         av = ubi_add_av(ai, vol_id);
 191         if (IS_ERR(av))
 192                 return av;
 193
 194         av->data_pad = data_pad;
 195         av->last_data_size = last_eb_bytes;
 196         av->compat = 0;
 197         av->vol_type = vol_type;
 198         if (av->vol_type == UBI_STATIC_VOLUME)
 199                 av->used_ebs = used_ebs;
 200
 201         dbg_bld("found volume (ID %i)", vol_id);
 202         return av;
 203 }
 204
 205 /**
 206  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 207  * from it's original list.
 208  * @ai: ubi_attach_info object
 209  * @aeb: the to be assigned SEB
 210  * @av: target scan volume
 211  */
 212 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 213                              struct ubi_ainf_peb *aeb,
 214                              struct ubi_ainf_volume *av)
 215 {
 216         struct ubi_ainf_peb *tmp_aeb;
 217         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 218
 219         while (*p) {
 220                 parent = *p;
 221
 222                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 223                 if (aeb->lnum != tmp_aeb->lnum) {
 224                         if (aeb->lnum < tmp_aeb->lnum)
 225                                 p = &(*p)->rb_left;
 226                         else
 227                                 p = &(*p)->rb_right;
 228
 229                         continue;
 230                 } else
 231                         break;
 232         }
 233
 234         list_del(&aeb->u.list);
 235         av->leb_count++;
 236
 237         rb_link_node(&aeb->u.rb, parent, p);
 238         rb_insert_color(&aeb->u.rb, &av->root);
 239 }
 240
 241 /**
 242  * update_vol - inserts or updates a LEB which was found a pool.
 243  * @ubi: the UBI device object
 244  * @ai: attach info object
 245  * @av: the volume this LEB belongs to
 246  * @new_vh: the volume header derived from new_aeb
 247  * @new_aeb: the AEB to be examined
 248  *
 249  * Returns 0 on success, < 0 indicates an internal error.
 250  */
 251 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 252                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 253                       struct ubi_ainf_peb *new_aeb)
 254 {
 255         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 256         struct ubi_ainf_peb *aeb, *victim;
 257         int cmp_res;
 258
 259         while (*p) {
 260                 parent = *p;
 261                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 262
 263                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 264                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 265                                 p = &(*p)->rb_left;
 266                         else
 267                                 p = &(*p)->rb_right;
 268
 269                         continue;
 270                 }
 271
 272                 /* This case can happen if the fastmap gets written
 273                  * because of a volume change (creation, deletion, ..).
 274                  * Then a PEB can be within the persistent EBA and the pool.
 275                  */
 276                 if (aeb->pnum == new_aeb->pnum) {
 277                         ubi_assert(aeb->lnum == new_aeb->lnum);
 278                         ubi_free_aeb(ai, new_aeb);
 279
 280                         return 0;
 281                 }
 282
 283                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 284                 if (cmp_res < 0)
 285                         return cmp_res;
 286
 287                 /* new_aeb is newer */
 288                 if (cmp_res & 1) {
 289                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 290                         if (!victim)
 291                                 return -ENOMEM;
 292
 293                         list_add_tail(&victim->u.list, &ai->erase);
 294
 295                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 296                                 av->last_data_size =
 297                                         be32_to_cpu(new_vh->data_size);
 298
 299                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 300                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 301
 302                         aeb->ec = new_aeb->ec;
 303                         aeb->pnum = new_aeb->pnum;
 304                         aeb->copy_flag = new_vh->copy_flag;
 305                         aeb->scrub = new_aeb->scrub;
 306                         aeb->sqnum = new_aeb->sqnum;
 307                         ubi_free_aeb(ai, new_aeb);
 308
 309                 /* new_aeb is older */
 310                 } else {
 311                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 312                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 313                         list_add_tail(&new_aeb->u.list, &ai->erase);
 314                 }
 315
 316                 return 0;
 317         }
 318         /* This LEB is new, let's add it to the volume */
 319
 320         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 321                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 322                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 323         }
 324
 325         if (av->vol_type == UBI_STATIC_VOLUME)
 326                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 327
 328         av->leb_count++;
 329
 330         rb_link_node(&new_aeb->u.rb, parent, p);
 331         rb_insert_color(&new_aeb->u.rb, &av->root);
 332
 333         return 0;
 334 }
 335
 336 /**
 337  * process_pool_aeb - we found a non-empty PEB in a pool.
 338  * @ubi: UBI device object
 339  * @ai: attach info object
 340  * @new_vh: the volume header derived from new_aeb
 341  * @new_aeb: the AEB to be examined
 342  *
 343  * Returns 0 on success, < 0 indicates an internal error.
 344  */
 345 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 346                             struct ubi_vid_hdr *new_vh,
 347                             struct ubi_ainf_peb *new_aeb)
 348 {
 349         int vol_id = be32_to_cpu(new_vh->vol_id);
 350         struct ubi_ainf_volume *av;
 351
 352         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 353                 ubi_free_aeb(ai, new_aeb);
 354
 355                 return 0;
 356         }
 357
 358         /* Find the volume this SEB belongs to */
 359         av = ubi_find_av(ai, vol_id);
 360         if (!av) {
 361                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 362                 ubi_free_aeb(ai, new_aeb);
 363                 return UBI_BAD_FASTMAP;
 364         }
 365
 366         ubi_assert(vol_id == av->vol_id);
 367
 368         return update_vol(ubi, ai, av, new_vh, new_aeb);
 369 }
 370
 371 /**
 372  * unmap_peb - unmap a PEB.
 373  * If fastmap detects a free PEB in the pool it has to check whether
 374  * this PEB has been unmapped after writing the fastmap.
 375  *
 376  * @ai: UBI attach info object
 377  * @pnum: The PEB to be unmapped
 378  */
 379 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 380 {
 381         struct ubi_ainf_volume *av;
 382         struct rb_node *node, *node2;
 383         struct ubi_ainf_peb *aeb;
 384
 385         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 386                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 387                         if (aeb->pnum == pnum) {
 388                                 rb_erase(&aeb->u.rb, &av->root);
 389                                 av->leb_count--;
 390                                 ubi_free_aeb(ai, aeb);
 391                                 return;
 392                         }
 393                 }
 394         }
 395 }
 396
 397 /**
 398  * scan_pool - scans a pool for changed (no longer empty PEBs).
 399  * @ubi: UBI device object
 400  * @ai: attach info object
 401  * @pebs: an array of all PEB numbers in the to be scanned pool
 402  * @pool_size: size of the pool (number of entries in @pebs)
 403  * @max_sqnum: pointer to the maximal sequence number
 404  * @free: list of PEBs which are most likely free (and go into @ai->free)
 405  *
 406  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 407  * < 0 indicates an internal error.
 408  */
 409 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 410                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 411                      struct list_head *free)
 412 {
 413         struct ubi_vid_io_buf *vb;
 414         struct ubi_vid_hdr *vh;
 415         struct ubi_ec_hdr *ech;
 416         struct ubi_ainf_peb *new_aeb;
 417         int i, pnum, err, ret = 0;
 418
 419         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 420         if (!ech)
 421                 return -ENOMEM;
 422
 423         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 424         if (!vb) {
 425                 kfree(ech);
 426                 return -ENOMEM;
 427         }
 428
 429         vh = ubi_get_vid_hdr(vb);
 430
 431         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 432
 433         /*
 434          * Now scan all PEBs in the pool to find changes which have been made
 435          * after the creation of the fastmap
 436          */
 437         for (i = 0; i < pool_size; i++) {
 438                 int scrub = 0;
 439                 int image_seq;
 440
 441                 pnum = be32_to_cpu(pebs[i]);
 442
 443                 if (ubi_io_is_bad(ubi, pnum)) {
 444                         ubi_err(ubi, "bad PEB in fastmap pool!");
 445                         ret = UBI_BAD_FASTMAP;
 446                         goto out;
 447                 }
 448
 449                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 450                 if (err && err != UBI_IO_BITFLIPS) {
 451                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 452                                 pnum, err);
 453                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 454                         goto out;
 455                 } else if (err == UBI_IO_BITFLIPS)
 456                         scrub = 1;
 457
 458                 /*
 459                  * Older UBI implementations have image_seq set to zero, so
 460                  * we shouldn't fail if image_seq == 0.
 461                  */
 462                 image_seq = be32_to_cpu(ech->image_seq);
 463
 464                 if (image_seq && (image_seq != ubi->image_seq)) {
 465                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 466                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 467                         ret = UBI_BAD_FASTMAP;
 468                         goto out;
 469                 }
 470
 471                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 472                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 473                         unsigned long long ec = be64_to_cpu(ech->ec);
 474                         unmap_peb(ai, pnum);
 475                         dbg_bld("Adding PEB to free: %i", pnum);
 476
 477                         if (err == UBI_IO_FF_BITFLIPS)
 478                                 scrub = 1;
 479
 480                         ret = add_aeb(ai, free, pnum, ec, scrub);
 481                         if (ret)
 482                                 goto out;
 483                         continue;
 484                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 485                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 486
 487                         if (err == UBI_IO_BITFLIPS)
 488                                 scrub = 1;
 489
 490                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 491                         if (!new_aeb) {
 492                                 ret = -ENOMEM;
 493                                 goto out;
 494                         }
 495
 496                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 497                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 498                         new_aeb->copy_flag = vh->copy_flag;
 499                         new_aeb->scrub = scrub;
 500
 501                         if (*max_sqnum < new_aeb->sqnum)
 502                                 *max_sqnum = new_aeb->sqnum;
 503
 504                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 505                         if (err) {
 506                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 507                                 goto out;
 508                         }
 509                 } else {
 510                         /* We are paranoid and fall back to scanning mode */
 511                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 512                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 513                         goto out;
 514                 }
 515
 516         }
 517
 518 out:
 519         ubi_free_vid_buf(vb);
 520         kfree(ech);
 521         return ret;
 522 }
 523
 524 /**
 525  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 526  * @ai: The UBI attach info object
 527  */
 528 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 529 {
 530         struct ubi_ainf_peb *aeb;
 531         struct ubi_ainf_volume *av;
 532         struct rb_node *rb1, *rb2;
 533         int n = 0;
 534
 535         list_for_each_entry(aeb, &ai->erase, u.list)
 536                 n++;
 537
 538         list_for_each_entry(aeb, &ai->free, u.list)
 539                 n++;
 540
 541         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 542                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 543                         n++;
 544
 545         return n;
 546 }
 547
 548 /**
 549  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 550  * @ubi: UBI device object
 551  * @ai: UBI attach info object
 552  * @fm: the fastmap to be attached
 553  *
 554  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 555  * < 0 indicates an internal error.
 556  */
 557 static int ubi_attach_fastmap(struct ubi_device *ubi,
 558                               struct ubi_attach_info *ai,
 559                               struct ubi_fastmap_layout *fm)
 560 {
 561         struct list_head used, free;
 562         struct ubi_ainf_volume *av;
 563         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 564         struct ubi_fm_sb *fmsb;
 565         struct ubi_fm_hdr *fmhdr;
 566         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 567         struct ubi_fm_ec *fmec;
 568         struct ubi_fm_volhdr *fmvhdr;
 569         struct ubi_fm_eba *fm_eba;
 570         int ret, i, j, pool_size, wl_pool_size;
 571         size_t fm_pos = 0, fm_size = ubi->fm_size;
 572         unsigned long long max_sqnum = 0;
 573         void *fm_raw = ubi->fm_buf;
 574
 575         INIT_LIST_HEAD(&used);
 576         INIT_LIST_HEAD(&free);
 577         ai->min_ec = UBI_MAX_ERASECOUNTER;
 578
 579         fmsb = (struct ubi_fm_sb *)(fm_raw);
 580         ai->max_sqnum = fmsb->sqnum;
 581         fm_pos += sizeof(struct ubi_fm_sb);
 582         if (fm_pos >= fm_size)
 583                 goto fail_bad;
 584
 585         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 586         fm_pos += sizeof(*fmhdr);
 587         if (fm_pos >= fm_size)
 588                 goto fail_bad;
 589
 590         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 591                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 592                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 593                 goto fail_bad;
 594         }
 595
 596         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 597         fm_pos += sizeof(*fmpl);
 598         if (fm_pos >= fm_size)
 599                 goto fail_bad;
 600         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 601                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 602                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 603                 goto fail_bad;
 604         }
 605
 606         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 607         fm_pos += sizeof(*fmpl_wl);
 608         if (fm_pos >= fm_size)
 609                 goto fail_bad;
 610         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 611                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 612                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 613                 goto fail_bad;
 614         }
 615
 616         pool_size = be16_to_cpu(fmpl->size);
 617         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 618         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 619         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 620
 621         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 622                 ubi_err(ubi, "bad pool size: %i", pool_size);
 623                 goto fail_bad;
 624         }
 625
 626         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 627                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 628                 goto fail_bad;
 629         }
 630
 631
 632         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 633             fm->max_pool_size < 0) {
 634                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 635                 goto fail_bad;
 636         }
 637
 638         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 639             fm->max_wl_pool_size < 0) {
 640                 ubi_err(ubi, "bad maximal WL pool size: %i",
 641                         fm->max_wl_pool_size);
 642                 goto fail_bad;
 643         }
 644
 645         /* read EC values from free list */
 646         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 647                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 648                 fm_pos += sizeof(*fmec);
 649                 if (fm_pos >= fm_size)
 650                         goto fail_bad;
 651
 652                 ret = add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 653                               be32_to_cpu(fmec->ec), 0);
 654                 if (ret)
 655                         goto fail;
 656         }
 657
 658         /* read EC values from used list */
 659         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 660                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 661                 fm_pos += sizeof(*fmec);
 662                 if (fm_pos >= fm_size)
 663                         goto fail_bad;
 664
 665                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 666                               be32_to_cpu(fmec->ec), 0);
 667                 if (ret)
 668                         goto fail;
 669         }
 670
 671         /* read EC values from scrub list */
 672         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 673                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 674                 fm_pos += sizeof(*fmec);
 675                 if (fm_pos >= fm_size)
 676                         goto fail_bad;
 677
 678                 ret = add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 679                               be32_to_cpu(fmec->ec), 1);
 680                 if (ret)
 681                         goto fail;
 682         }
 683
 684         /* read EC values from erase list */
 685         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 686                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 687                 fm_pos += sizeof(*fmec);
 688                 if (fm_pos >= fm_size)
 689                         goto fail_bad;
 690
 691                 ret = add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 692                               be32_to_cpu(fmec->ec), 1);
 693                 if (ret)
 694                         goto fail;
 695         }
 696
 697         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 698         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 699
 700         /* Iterate over all volumes and read their EBA table */
 701         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 702                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 703                 fm_pos += sizeof(*fmvhdr);
 704                 if (fm_pos >= fm_size)
 705                         goto fail_bad;
 706
 707                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 708                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 709                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 710                         goto fail_bad;
 711                 }
 712
 713                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 714                              be32_to_cpu(fmvhdr->used_ebs),
 715                              be32_to_cpu(fmvhdr->data_pad),
 716                              fmvhdr->vol_type,
 717                              be32_to_cpu(fmvhdr->last_eb_bytes));
 718
 719                 if (IS_ERR(av)) {
 720                         if (PTR_ERR(av) == -EEXIST)
 721                                 ubi_err(ubi, "volume (ID %i) already exists",
 722                                         fmvhdr->vol_id);
 723
 724                         goto fail_bad;
 725                 }
 726
 727                 ai->vols_found++;
 728                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 729                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 730
 731                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 732                 fm_pos += sizeof(*fm_eba);
 733                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 734                 if (fm_pos >= fm_size)
 735                         goto fail_bad;
 736
 737                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 738                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 739                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 740                         goto fail_bad;
 741                 }
 742
 743                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 744                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 745
 746                         if (pnum < 0)
 747                                 continue;
 748
 749                         aeb = NULL;
 750                         list_for_each_entry(tmp_aeb, &used, u.list) {
 751                                 if (tmp_aeb->pnum == pnum) {
 752                                         aeb = tmp_aeb;
 753                                         break;
 754                                 }
 755                         }
 756
 757                         if (!aeb) {
 758                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 759                                 goto fail_bad;
 760                         }
 761
 762                         aeb->lnum = j;
 763
 764                         if (av->highest_lnum <= aeb->lnum)
 765                                 av->highest_lnum = aeb->lnum;
 766
 767                         assign_aeb_to_av(ai, aeb, av);
 768
 769                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 770                                 aeb->pnum, aeb->lnum, av->vol_id);
 771                 }
 772         }
 773
 774         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 775         if (ret)
 776                 goto fail;
 777
 778         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 779         if (ret)
 780                 goto fail;
 781
 782         if (max_sqnum > ai->max_sqnum)
 783                 ai->max_sqnum = max_sqnum;
 784
 785         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 786                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 787
 788         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 789                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 790
 791         ubi_assert(list_empty(&free));
 792
 793         /*
 794          * If fastmap is leaking PEBs (must not happen), raise a
 795          * fat warning and fall back to scanning mode.
 796          * We do this here because in ubi_wl_init() it's too late
 797          * and we cannot fall back to scanning.
 798          */
 799         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 800                     ai->bad_peb_count - fm->used_blocks))
 801                 goto fail_bad;
 802
 803         return 0;
 804
 805 fail_bad:
 806         ret = UBI_BAD_FASTMAP;
 807 fail:
 808         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 809                 list_del(&tmp_aeb->u.list);
 810                 ubi_free_aeb(ai, tmp_aeb);
 811         }
 812         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 813                 list_del(&tmp_aeb->u.list);
 814                 ubi_free_aeb(ai, tmp_aeb);
 815         }
 816
 817         return ret;
 818 }
 819
 820 /**
 821  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 822  * @ai: UBI attach info to be filled
 823  */
 824 static int find_fm_anchor(struct ubi_attach_info *ai)
 825 {
 826         int ret = -1;
 827         struct ubi_ainf_peb *aeb;
 828         unsigned long long max_sqnum = 0;
 829
 830         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 831                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 832                         max_sqnum = aeb->sqnum;
 833                         ret = aeb->pnum;
 834                 }
 835         }
 836
 837         return ret;
 838 }
 839
 840 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 841                                       struct ubi_ainf_peb *old)
 842 {
 843         struct ubi_ainf_peb *new;
 844
 845         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 846         if (!new)
 847                 return NULL;
 848
 849         new->vol_id = old->vol_id;
 850         new->sqnum = old->sqnum;
 851         new->lnum = old->lnum;
 852         new->scrub = old->scrub;
 853         new->copy_flag = old->copy_flag;
 854
 855         return new;
 856 }
 857
 858 /**
 859  * ubi_scan_fastmap - scan the fastmap.
 860  * @ubi: UBI device object
 861  * @ai: UBI attach info to be filled
 862  * @scan_ai: UBI attach info from the first 64 PEBs,
 863  *           used to find the most recent Fastmap data structure
 864  *
 865  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 866  * UBI_BAD_FASTMAP if one was found but is not usable.
 867  * < 0 indicates an internal error.
 868  */
 869 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 870                      struct ubi_attach_info *scan_ai)
 871 {
 872         struct ubi_fm_sb *fmsb, *fmsb2;
 873         struct ubi_vid_io_buf *vb;
 874         struct ubi_vid_hdr *vh;
 875         struct ubi_ec_hdr *ech;
 876         struct ubi_fastmap_layout *fm;
 877         struct ubi_ainf_peb *aeb;
 878         int i, used_blocks, pnum, fm_anchor, ret = 0;
 879         size_t fm_size;
 880         __be32 crc, tmp_crc;
 881         unsigned long long sqnum = 0;
 882
 883         fm_anchor = find_fm_anchor(scan_ai);
 884         if (fm_anchor < 0)
 885                 return UBI_NO_FASTMAP;
 886
 887         /* Copy all (possible) fastmap blocks into our new attach structure. */
 888         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 889                 struct ubi_ainf_peb *new;
 890
 891                 new = clone_aeb(ai, aeb);
 892                 if (!new)
 893                         return -ENOMEM;
 894
 895                 list_add(&new->u.list, &ai->fastmap);
 896         }
 897
 898         down_write(&ubi->fm_protect);
 899         memset(ubi->fm_buf, 0, ubi->fm_size);
 900
 901         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 902         if (!fmsb) {
 903                 ret = -ENOMEM;
 904                 goto out;
 905         }
 906
 907         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 908         if (!fm) {
 909                 ret = -ENOMEM;
 910                 kfree(fmsb);
 911                 goto out;
 912         }
 913
 914         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 915         if (ret && ret != UBI_IO_BITFLIPS)
 916                 goto free_fm_sb;
 917         else if (ret == UBI_IO_BITFLIPS)
 918                 fm->to_be_tortured[0] = 1;
 919
 920         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 921                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 922                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 923                 ret = UBI_BAD_FASTMAP;
 924                 goto free_fm_sb;
 925         }
 926
 927         if (fmsb->version != UBI_FM_FMT_VERSION) {
 928                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 929                         fmsb->version, UBI_FM_FMT_VERSION);
 930                 ret = UBI_BAD_FASTMAP;
 931                 goto free_fm_sb;
 932         }
 933
 934         used_blocks = be32_to_cpu(fmsb->used_blocks);
 935         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 936                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 937                         used_blocks);
 938                 ret = UBI_BAD_FASTMAP;
 939                 goto free_fm_sb;
 940         }
 941
 942         fm_size = ubi->leb_size * used_blocks;
 943         if (fm_size != ubi->fm_size) {
 944                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 945                         fm_size, ubi->fm_size);
 946                 ret = UBI_BAD_FASTMAP;
 947                 goto free_fm_sb;
 948         }
 949
 950         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 951         if (!ech) {
 952                 ret = -ENOMEM;
 953                 goto free_fm_sb;
 954         }
 955
 956         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 957         if (!vb) {
 958                 ret = -ENOMEM;
 959                 goto free_hdr;
 960         }
 961
 962         vh = ubi_get_vid_hdr(vb);
 963
 964         for (i = 0; i < used_blocks; i++) {
 965                 int image_seq;
 966
 967                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 968
 969                 if (ubi_io_is_bad(ubi, pnum)) {
 970                         ret = UBI_BAD_FASTMAP;
 971                         goto free_hdr;
 972                 }
 973
 974                 if (i == 0 && pnum != fm_anchor) {
 975                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 976                                 pnum, fm_anchor);
 977                         ret = UBI_BAD_FASTMAP;
 978                         goto free_hdr;
 979                 }
 980
 981                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 982                 if (ret && ret != UBI_IO_BITFLIPS) {
 983                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 984                                 i, pnum);
 985                         if (ret > 0)
 986                                 ret = UBI_BAD_FASTMAP;
 987                         goto free_hdr;
 988                 } else if (ret == UBI_IO_BITFLIPS)
 989                         fm->to_be_tortured[i] = 1;
 990
 991                 image_seq = be32_to_cpu(ech->image_seq);
 992                 if (!ubi->image_seq)
 993                         ubi->image_seq = image_seq;
 994
 995                 /*
 996                  * Older UBI implementations have image_seq set to zero, so
 997                  * we shouldn't fail if image_seq == 0.
 998                  */
 999                 if (image_seq && (image_seq != ubi->image_seq)) {
1000                         ubi_err(ubi, "wrong image seq:%d instead of %d",
1001                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
1002                         ret = UBI_BAD_FASTMAP;
1003                         goto free_hdr;
1004                 }
1005
1006                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
1007                 if (ret && ret != UBI_IO_BITFLIPS) {
1008                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
1009                                 i, pnum);
1010                         goto free_hdr;
1011                 }
1012
1013                 if (i == 0) {
1014                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1015                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
1016                                         be32_to_cpu(vh->vol_id),
1017                                         UBI_FM_SB_VOLUME_ID);
1018                                 ret = UBI_BAD_FASTMAP;
1019                                 goto free_hdr;
1020                         }
1021                 } else {
1022                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1023                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
1024                                         be32_to_cpu(vh->vol_id),
1025                                         UBI_FM_DATA_VOLUME_ID);
1026                                 ret = UBI_BAD_FASTMAP;
1027                                 goto free_hdr;
1028                         }
1029                 }
1030
1031                 if (sqnum < be64_to_cpu(vh->sqnum))
1032                         sqnum = be64_to_cpu(vh->sqnum);
1033
1034                 ret = ubi_io_read_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1035                                        pnum, 0, ubi->leb_size);
1036                 if (ret && ret != UBI_IO_BITFLIPS) {
1037                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1038                                 "err: %i)", i, pnum, ret);
1039                         goto free_hdr;
1040                 }
1041         }
1042
1043         kfree(fmsb);
1044         fmsb = NULL;
1045
1046         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1047         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1048         fmsb2->data_crc = 0;
1049         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1050         if (crc != tmp_crc) {
1051                 ubi_err(ubi, "fastmap data CRC is invalid");
1052                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1053                         tmp_crc, crc);
1054                 ret = UBI_BAD_FASTMAP;
1055                 goto free_hdr;
1056         }
1057
1058         fmsb2->sqnum = sqnum;
1059
1060         fm->used_blocks = used_blocks;
1061
1062         ret = ubi_attach_fastmap(ubi, ai, fm);
1063         if (ret) {
1064                 if (ret > 0)
1065                         ret = UBI_BAD_FASTMAP;
1066                 goto free_hdr;
1067         }
1068
1069         for (i = 0; i < used_blocks; i++) {
1070                 struct ubi_wl_entry *e;
1071
1072                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1073                 if (!e) {
1074                         while (i--)
1075                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1076
1077                         ret = -ENOMEM;
1078                         goto free_hdr;
1079                 }
1080
1081                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1082                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1083                 fm->e[i] = e;
1084         }
1085
1086         ubi->fm = fm;
1087         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1088         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1089         ubi_msg(ubi, "attached by fastmap");
1090         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1091         ubi_msg(ubi, "fastmap WL pool size: %d",
1092                 ubi->fm_wl_pool.max_size);
1093         ubi->fm_disabled = 0;
1094         ubi->fast_attach = 1;
1095
1096         ubi_free_vid_buf(vb);
1097         kfree(ech);
1098 out:
1099         up_write(&ubi->fm_protect);
1100         if (ret == UBI_BAD_FASTMAP)
1101                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1102         return ret;
1103
1104 free_hdr:
1105         ubi_free_vid_buf(vb);
1106         kfree(ech);
1107 free_fm_sb:
1108         kfree(fmsb);
1109         kfree(fm);
1110         goto out;
1111 }
1112
1113 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1114 {
1115         struct ubi_device *ubi = vol->ubi;
1116
1117         if (!ubi->fast_attach)
1118                 return 0;
1119
1120         vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
1121                                 GFP_KERNEL);
1122         if (!vol->checkmap)
1123                 return -ENOMEM;
1124
1125         return 0;
1126 }
1127
1128 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1129 {
1130         kfree(vol->checkmap);
1131 }
1132
1133 /**
1134  * ubi_write_fastmap - writes a fastmap.
1135  * @ubi: UBI device object
1136  * @new_fm: the to be written fastmap
1137  *
1138  * Returns 0 on success, < 0 indicates an internal error.
1139  */
1140 static int ubi_write_fastmap(struct ubi_device *ubi,
1141                              struct ubi_fastmap_layout *new_fm)
1142 {
1143         size_t fm_pos = 0;
1144         void *fm_raw;
1145         struct ubi_fm_sb *fmsb;
1146         struct ubi_fm_hdr *fmh;
1147         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1148         struct ubi_fm_ec *fec;
1149         struct ubi_fm_volhdr *fvh;
1150         struct ubi_fm_eba *feba;
1151         struct ubi_wl_entry *wl_e;
1152         struct ubi_volume *vol;
1153         struct ubi_vid_io_buf *avbuf, *dvbuf;
1154         struct ubi_vid_hdr *avhdr, *dvhdr;
1155         struct ubi_work *ubi_wrk;
1156         struct rb_node *tmp_rb;
1157         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1158         int scrub_peb_count, erase_peb_count;
1159         unsigned long *seen_pebs;
1160
1161         fm_raw = ubi->fm_buf;
1162         memset(ubi->fm_buf, 0, ubi->fm_size);
1163
1164         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1165         if (!avbuf) {
1166                 ret = -ENOMEM;
1167                 goto out;
1168         }
1169
1170         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1171         if (!dvbuf) {
1172                 ret = -ENOMEM;
1173                 goto out_free_avbuf;
1174         }
1175
1176         avhdr = ubi_get_vid_hdr(avbuf);
1177         dvhdr = ubi_get_vid_hdr(dvbuf);
1178
1179         seen_pebs = init_seen(ubi);
1180         if (IS_ERR(seen_pebs)) {
1181                 ret = PTR_ERR(seen_pebs);
1182                 goto out_free_dvbuf;
1183         }
1184
1185         spin_lock(&ubi->volumes_lock);
1186         spin_lock(&ubi->wl_lock);
1187
1188         fmsb = (struct ubi_fm_sb *)fm_raw;
1189         fm_pos += sizeof(*fmsb);
1190         ubi_assert(fm_pos <= ubi->fm_size);
1191
1192         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1193         fm_pos += sizeof(*fmh);
1194         ubi_assert(fm_pos <= ubi->fm_size);
1195
1196         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1197         fmsb->version = UBI_FM_FMT_VERSION;
1198         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1199         /* the max sqnum will be filled in while *reading* the fastmap */
1200         fmsb->sqnum = 0;
1201
1202         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1203         free_peb_count = 0;
1204         used_peb_count = 0;
1205         scrub_peb_count = 0;
1206         erase_peb_count = 0;
1207         vol_count = 0;
1208
1209         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1210         fm_pos += sizeof(*fmpl);
1211         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1212         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1213         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1214
1215         for (i = 0; i < ubi->fm_pool.size; i++) {
1216                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1217                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1218         }
1219
1220         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1221         fm_pos += sizeof(*fmpl_wl);
1222         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1223         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1224         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1225
1226         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1227                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1228                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1229         }
1230
1231         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
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                 free_peb_count++;
1239                 fm_pos += sizeof(*fec);
1240                 ubi_assert(fm_pos <= ubi->fm_size);
1241         }
1242         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1243
1244         ubi_for_each_used_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                 used_peb_count++;
1252                 fm_pos += sizeof(*fec);
1253                 ubi_assert(fm_pos <= ubi->fm_size);
1254         }
1255
1256         ubi_for_each_protected_peb(ubi, i, wl_e) {
1257                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1258
1259                 fec->pnum = cpu_to_be32(wl_e->pnum);
1260                 set_seen(ubi, wl_e->pnum, seen_pebs);
1261                 fec->ec = cpu_to_be32(wl_e->ec);
1262
1263                 used_peb_count++;
1264                 fm_pos += sizeof(*fec);
1265                 ubi_assert(fm_pos <= ubi->fm_size);
1266         }
1267         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1268
1269         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1270                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1271
1272                 fec->pnum = cpu_to_be32(wl_e->pnum);
1273                 set_seen(ubi, wl_e->pnum, seen_pebs);
1274                 fec->ec = cpu_to_be32(wl_e->ec);
1275
1276                 scrub_peb_count++;
1277                 fm_pos += sizeof(*fec);
1278                 ubi_assert(fm_pos <= ubi->fm_size);
1279         }
1280         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1281
1282
1283         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1284                 if (ubi_is_erase_work(ubi_wrk)) {
1285                         wl_e = ubi_wrk->e;
1286                         ubi_assert(wl_e);
1287
1288                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1289
1290                         fec->pnum = cpu_to_be32(wl_e->pnum);
1291                         set_seen(ubi, wl_e->pnum, seen_pebs);
1292                         fec->ec = cpu_to_be32(wl_e->ec);
1293
1294                         erase_peb_count++;
1295                         fm_pos += sizeof(*fec);
1296                         ubi_assert(fm_pos <= ubi->fm_size);
1297                 }
1298         }
1299         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1300
1301         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1302                 vol = ubi->volumes[i];
1303
1304                 if (!vol)
1305                         continue;
1306
1307                 vol_count++;
1308
1309                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1310                 fm_pos += sizeof(*fvh);
1311                 ubi_assert(fm_pos <= ubi->fm_size);
1312
1313                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1314                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1315                 fvh->vol_type = vol->vol_type;
1316                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1317                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1318                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1319
1320                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1321                         vol->vol_type == UBI_STATIC_VOLUME);
1322
1323                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1324                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1325                 ubi_assert(fm_pos <= ubi->fm_size);
1326
1327                 for (j = 0; j < vol->reserved_pebs; j++) {
1328                         struct ubi_eba_leb_desc ldesc;
1329
1330                         ubi_eba_get_ldesc(vol, j, &ldesc);
1331                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1332                 }
1333
1334                 feba->reserved_pebs = cpu_to_be32(j);
1335                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1336         }
1337         fmh->vol_count = cpu_to_be32(vol_count);
1338         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1339
1340         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1341         avhdr->lnum = 0;
1342
1343         spin_unlock(&ubi->wl_lock);
1344         spin_unlock(&ubi->volumes_lock);
1345
1346         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1347         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1348         if (ret) {
1349                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1350                 goto out_free_seen;
1351         }
1352
1353         for (i = 0; i < new_fm->used_blocks; i++) {
1354                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1355                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1356                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1357         }
1358
1359         fmsb->data_crc = 0;
1360         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1361                                            ubi->fm_size));
1362
1363         for (i = 1; i < new_fm->used_blocks; i++) {
1364                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1365                 dvhdr->lnum = cpu_to_be32(i);
1366                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1367                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1368                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1369                 if (ret) {
1370                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1371                                 new_fm->e[i]->pnum);
1372                         goto out_free_seen;
1373                 }
1374         }
1375
1376         for (i = 0; i < new_fm->used_blocks; i++) {
1377                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1378                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1379                 if (ret) {
1380                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1381                                 new_fm->e[i]->pnum);
1382                         goto out_free_seen;
1383                 }
1384         }
1385
1386         ubi_assert(new_fm);
1387         ubi->fm = new_fm;
1388
1389         ret = self_check_seen(ubi, seen_pebs);
1390         dbg_bld("fastmap written!");
1391
1392 out_free_seen:
1393         free_seen(seen_pebs);
1394 out_free_dvbuf:
1395         ubi_free_vid_buf(dvbuf);
1396 out_free_avbuf:
1397         ubi_free_vid_buf(avbuf);
1398
1399 out:
1400         return ret;
1401 }
1402
1403 /**
1404  * erase_block - Manually erase a PEB.
1405  * @ubi: UBI device object
1406  * @pnum: PEB to be erased
1407  *
1408  * Returns the new EC value on success, < 0 indicates an internal error.
1409  */
1410 static int erase_block(struct ubi_device *ubi, int pnum)
1411 {
1412         int ret;
1413         struct ubi_ec_hdr *ec_hdr;
1414         long long ec;
1415
1416         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1417         if (!ec_hdr)
1418                 return -ENOMEM;
1419
1420         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1421         if (ret < 0)
1422                 goto out;
1423         else if (ret && ret != UBI_IO_BITFLIPS) {
1424                 ret = -EINVAL;
1425                 goto out;
1426         }
1427
1428         ret = ubi_io_sync_erase(ubi, pnum, 0);
1429         if (ret < 0)
1430                 goto out;
1431
1432         ec = be64_to_cpu(ec_hdr->ec);
1433         ec += ret;
1434         if (ec > UBI_MAX_ERASECOUNTER) {
1435                 ret = -EINVAL;
1436                 goto out;
1437         }
1438
1439         ec_hdr->ec = cpu_to_be64(ec);
1440         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1441         if (ret < 0)
1442                 goto out;
1443
1444         ret = ec;
1445 out:
1446         kfree(ec_hdr);
1447         return ret;
1448 }
1449
1450 /**
1451  * invalidate_fastmap - destroys a fastmap.
1452  * @ubi: UBI device object
1453  *
1454  * This function ensures that upon next UBI attach a full scan
1455  * is issued. We need this if UBI is about to write a new fastmap
1456  * but is unable to do so. In this case we have two options:
1457  * a) Make sure that the current fastmap will not be usued upon
1458  * attach time and contine or b) fall back to RO mode to have the
1459  * current fastmap in a valid state.
1460  * Returns 0 on success, < 0 indicates an internal error.
1461  */
1462 static int invalidate_fastmap(struct ubi_device *ubi)
1463 {
1464         int ret;
1465         struct ubi_fastmap_layout *fm;
1466         struct ubi_wl_entry *e;
1467         struct ubi_vid_io_buf *vb = NULL;
1468         struct ubi_vid_hdr *vh;
1469
1470         if (!ubi->fm)
1471                 return 0;
1472
1473         ubi->fm = NULL;
1474
1475         ret = -ENOMEM;
1476         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1477         if (!fm)
1478                 goto out;
1479
1480         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1481         if (!vb)
1482                 goto out_free_fm;
1483
1484         vh = ubi_get_vid_hdr(vb);
1485
1486         ret = -ENOSPC;
1487         e = ubi_wl_get_fm_peb(ubi, 1);
1488         if (!e)
1489                 goto out_free_fm;
1490
1491         /*
1492          * Create fake fastmap such that UBI will fall back
1493          * to scanning mode.
1494          */
1495         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1496         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1497         if (ret < 0) {
1498                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1499                 goto out_free_fm;
1500         }
1501
1502         fm->used_blocks = 1;
1503         fm->e[0] = e;
1504
1505         ubi->fm = fm;
1506
1507 out:
1508         ubi_free_vid_buf(vb);
1509         return ret;
1510
1511 out_free_fm:
1512         kfree(fm);
1513         goto out;
1514 }
1515
1516 /**
1517  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1518  * WL sub-system.
1519  * @ubi: UBI device object
1520  * @fm: fastmap layout object
1521  */
1522 static void return_fm_pebs(struct ubi_device *ubi,
1523                            struct ubi_fastmap_layout *fm)
1524 {
1525         int i;
1526
1527         if (!fm)
1528                 return;
1529
1530         for (i = 0; i < fm->used_blocks; i++) {
1531                 if (fm->e[i]) {
1532                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1533                                           fm->to_be_tortured[i]);
1534                         fm->e[i] = NULL;
1535                 }
1536         }
1537 }
1538
1539 /**
1540  * ubi_update_fastmap - will be called by UBI if a volume changes or
1541  * a fastmap pool becomes full.
1542  * @ubi: UBI device object
1543  *
1544  * Returns 0 on success, < 0 indicates an internal error.
1545  */
1546 int ubi_update_fastmap(struct ubi_device *ubi)
1547 {
1548         int ret, i, j;
1549         struct ubi_fastmap_layout *new_fm, *old_fm;
1550         struct ubi_wl_entry *tmp_e;
1551
1552         down_write(&ubi->fm_protect);
1553         down_write(&ubi->work_sem);
1554         down_write(&ubi->fm_eba_sem);
1555
1556         ubi_refill_pools(ubi);
1557
1558         if (ubi->ro_mode || ubi->fm_disabled) {
1559                 up_write(&ubi->fm_eba_sem);
1560                 up_write(&ubi->work_sem);
1561                 up_write(&ubi->fm_protect);
1562                 return 0;
1563         }
1564
1565         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1566         if (!new_fm) {
1567                 up_write(&ubi->fm_eba_sem);
1568                 up_write(&ubi->work_sem);
1569                 up_write(&ubi->fm_protect);
1570                 return -ENOMEM;
1571         }
1572
1573         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1574         old_fm = ubi->fm;
1575         ubi->fm = NULL;
1576
1577         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1578                 ubi_err(ubi, "fastmap too large");
1579                 ret = -ENOSPC;
1580                 goto err;
1581         }
1582
1583         for (i = 1; i < new_fm->used_blocks; i++) {
1584                 spin_lock(&ubi->wl_lock);
1585                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1586                 spin_unlock(&ubi->wl_lock);
1587
1588                 if (!tmp_e) {
1589                         if (old_fm && old_fm->e[i]) {
1590                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1591                                 if (ret < 0) {
1592                                         ubi_err(ubi, "could not erase old fastmap PEB");
1593
1594                                         for (j = 1; j < i; j++) {
1595                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1596                                                                   j, 0);
1597                                                 new_fm->e[j] = NULL;
1598                                         }
1599                                         goto err;
1600                                 }
1601                                 new_fm->e[i] = old_fm->e[i];
1602                                 old_fm->e[i] = NULL;
1603                         } else {
1604                                 ubi_err(ubi, "could not get any free erase block");
1605
1606                                 for (j = 1; j < i; j++) {
1607                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1608                                         new_fm->e[j] = NULL;
1609                                 }
1610
1611                                 ret = -ENOSPC;
1612                                 goto err;
1613                         }
1614                 } else {
1615                         new_fm->e[i] = tmp_e;
1616
1617                         if (old_fm && old_fm->e[i]) {
1618                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1619                                                   old_fm->to_be_tortured[i]);
1620                                 old_fm->e[i] = NULL;
1621                         }
1622                 }
1623         }
1624
1625         /* Old fastmap is larger than the new one */
1626         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1627                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1628                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1629                                           old_fm->to_be_tortured[i]);
1630                         old_fm->e[i] = NULL;
1631                 }
1632         }
1633
1634         spin_lock(&ubi->wl_lock);
1635         tmp_e = ubi->fm_anchor;
1636         ubi->fm_anchor = NULL;
1637         spin_unlock(&ubi->wl_lock);
1638
1639         if (old_fm) {
1640                 /* no fresh anchor PEB was found, reuse the old one */
1641                 if (!tmp_e) {
1642                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1643                         if (ret < 0) {
1644                                 ubi_err(ubi, "could not erase old anchor PEB");
1645
1646                                 for (i = 1; i < new_fm->used_blocks; i++) {
1647                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1648                                                           i, 0);
1649                                         new_fm->e[i] = NULL;
1650                                 }
1651                                 goto err;
1652                         }
1653                         new_fm->e[0] = old_fm->e[0];
1654                         new_fm->e[0]->ec = ret;
1655                         old_fm->e[0] = NULL;
1656                 } else {
1657                         /* we've got a new anchor PEB, return the old one */
1658                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1659                                           old_fm->to_be_tortured[0]);
1660                         new_fm->e[0] = tmp_e;
1661                         old_fm->e[0] = NULL;
1662                 }
1663         } else {
1664                 if (!tmp_e) {
1665                         ubi_err(ubi, "could not find any anchor PEB");
1666
1667                         for (i = 1; i < new_fm->used_blocks; i++) {
1668                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1669                                 new_fm->e[i] = NULL;
1670                         }
1671
1672                         ret = -ENOSPC;
1673                         goto err;
1674                 }
1675                 new_fm->e[0] = tmp_e;
1676         }
1677
1678         ret = ubi_write_fastmap(ubi, new_fm);
1679
1680         if (ret)
1681                 goto err;
1682
1683 out_unlock:
1684         up_write(&ubi->fm_eba_sem);
1685         up_write(&ubi->work_sem);
1686         up_write(&ubi->fm_protect);
1687         kfree(old_fm);
1688
1689         ubi_ensure_anchor_pebs(ubi);
1690
1691         return ret;
1692
1693 err:
1694         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1695
1696         ret = invalidate_fastmap(ubi);
1697         if (ret < 0) {
1698                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1699                 ubi_ro_mode(ubi);
1700         } else {
1701                 return_fm_pebs(ubi, old_fm);
1702                 return_fm_pebs(ubi, new_fm);
1703                 ret = 0;
1704         }
1705
1706         kfree(new_fm);
1707         goto out_unlock;
1708 }