drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Author: Richard Weinberger <richard@nod.at>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include <linux/crc32.h>
  17 #include "ubi.h"
  18
  19 /**
  20  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  21  * @ubi: UBI device description object
  22  */
  23 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  24 {
  25         size_t size;
  26
  27         size = sizeof(struct ubi_fm_sb) + \
  28                 sizeof(struct ubi_fm_hdr) + \
  29                 sizeof(struct ubi_fm_scan_pool) + \
  30                 sizeof(struct ubi_fm_scan_pool) + \
  31                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
  32                 (sizeof(struct ubi_fm_eba) + \
  33                 (ubi->peb_count * sizeof(__be32))) + \
  34                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  35         return roundup(size, ubi->leb_size);
  36 }
  37
  38
  39 /**
  40  * new_fm_vhdr - allocate a new volume header for fastmap usage.
  41  * @ubi: UBI device description object
  42  * @vol_id: the VID of the new header
  43  *
  44  * Returns a new struct ubi_vid_hdr on success.
  45  * NULL indicates out of memory.
  46  */
  47 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
  48 {
  49         struct ubi_vid_hdr *new;
  50
  51         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
  52         if (!new)
  53                 goto out;
  54
  55         new->vol_type = UBI_VID_DYNAMIC;
  56         new->vol_id = cpu_to_be32(vol_id);
  57
  58         /* UBI implementations without fastmap support have to delete the
  59          * fastmap.
  60          */
  61         new->compat = UBI_COMPAT_DELETE;
  62
  63 out:
  64         return new;
  65 }
  66
  67 /**
  68  * add_aeb - create and add a attach erase block to a given list.
  69  * @ai: UBI attach info object
  70  * @list: the target list
  71  * @pnum: PEB number of the new attach erase block
  72  * @ec: erease counter of the new LEB
  73  * @scrub: scrub this PEB after attaching
  74  *
  75  * Returns 0 on success, < 0 indicates an internal error.
  76  */
  77 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
  78                    int pnum, int ec, int scrub)
  79 {
  80         struct ubi_ainf_peb *aeb;
  81
  82         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
  83         if (!aeb)
  84                 return -ENOMEM;
  85
  86         aeb->pnum = pnum;
  87         aeb->ec = ec;
  88         aeb->lnum = -1;
  89         aeb->scrub = scrub;
  90         aeb->copy_flag = aeb->sqnum = 0;
  91
  92         ai->ec_sum += aeb->ec;
  93         ai->ec_count++;
  94
  95         if (ai->max_ec < aeb->ec)
  96                 ai->max_ec = aeb->ec;
  97
  98         if (ai->min_ec > aeb->ec)
  99                 ai->min_ec = aeb->ec;
 100
 101         list_add_tail(&aeb->u.list, list);
 102
 103         return 0;
 104 }
 105
 106 /**
 107  * add_vol - create and add a new volume to ubi_attach_info.
 108  * @ai: ubi_attach_info object
 109  * @vol_id: VID of the new volume
 110  * @used_ebs: number of used EBS
 111  * @data_pad: data padding value of the new volume
 112  * @vol_type: volume type
 113  * @last_eb_bytes: number of bytes in the last LEB
 114  *
 115  * Returns the new struct ubi_ainf_volume on success.
 116  * NULL indicates an error.
 117  */
 118 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 119                                        int used_ebs, int data_pad, u8 vol_type,
 120                                        int last_eb_bytes)
 121 {
 122         struct ubi_ainf_volume *av;
 123         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 124
 125         while (*p) {
 126                 parent = *p;
 127                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 128
 129                 if (vol_id > av->vol_id)
 130                         p = &(*p)->rb_left;
 131                 else
 132                         p = &(*p)->rb_right;
 133         }
 134
 135         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 136         if (!av)
 137                 goto out;
 138
 139         av->highest_lnum = av->leb_count = 0;
 140         av->vol_id = vol_id;
 141         av->used_ebs = used_ebs;
 142         av->data_pad = data_pad;
 143         av->last_data_size = last_eb_bytes;
 144         av->compat = 0;
 145         av->vol_type = vol_type;
 146         av->root = RB_ROOT;
 147
 148         dbg_bld("found volume (ID %i)", vol_id);
 149
 150         rb_link_node(&av->rb, parent, p);
 151         rb_insert_color(&av->rb, &ai->volumes);
 152
 153 out:
 154         return av;
 155 }
 156
 157 /**
 158  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 159  * from it's original list.
 160  * @ai: ubi_attach_info object
 161  * @aeb: the to be assigned SEB
 162  * @av: target scan volume
 163  */
 164 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 165                              struct ubi_ainf_peb *aeb,
 166                              struct ubi_ainf_volume *av)
 167 {
 168         struct ubi_ainf_peb *tmp_aeb;
 169         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 170
 171         p = &av->root.rb_node;
 172         while (*p) {
 173                 parent = *p;
 174
 175                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 176                 if (aeb->lnum != tmp_aeb->lnum) {
 177                         if (aeb->lnum < tmp_aeb->lnum)
 178                                 p = &(*p)->rb_left;
 179                         else
 180                                 p = &(*p)->rb_right;
 181
 182                         continue;
 183                 } else
 184                         break;
 185         }
 186
 187         list_del(&aeb->u.list);
 188         av->leb_count++;
 189
 190         rb_link_node(&aeb->u.rb, parent, p);
 191         rb_insert_color(&aeb->u.rb, &av->root);
 192 }
 193
 194 /**
 195  * update_vol - inserts or updates a LEB which was found a pool.
 196  * @ubi: the UBI device object
 197  * @ai: attach info object
 198  * @av: the volume this LEB belongs to
 199  * @new_vh: the volume header derived from new_aeb
 200  * @new_aeb: the AEB to be examined
 201  *
 202  * Returns 0 on success, < 0 indicates an internal error.
 203  */
 204 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 205                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 206                       struct ubi_ainf_peb *new_aeb)
 207 {
 208         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 209         struct ubi_ainf_peb *aeb, *victim;
 210         int cmp_res;
 211
 212         while (*p) {
 213                 parent = *p;
 214                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 215
 216                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 217                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 218                                 p = &(*p)->rb_left;
 219                         else
 220                                 p = &(*p)->rb_right;
 221
 222                         continue;
 223                 }
 224
 225                 /* This case can happen if the fastmap gets written
 226                  * because of a volume change (creation, deletion, ..).
 227                  * Then a PEB can be within the persistent EBA and the pool.
 228                  */
 229                 if (aeb->pnum == new_aeb->pnum) {
 230                         ubi_assert(aeb->lnum == new_aeb->lnum);
 231                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 232
 233                         return 0;
 234                 }
 235
 236                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 237                 if (cmp_res < 0)
 238                         return cmp_res;
 239
 240                 /* new_aeb is newer */
 241                 if (cmp_res & 1) {
 242                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 243                                 GFP_KERNEL);
 244                         if (!victim)
 245                                 return -ENOMEM;
 246
 247                         victim->ec = aeb->ec;
 248                         victim->pnum = aeb->pnum;
 249                         list_add_tail(&victim->u.list, &ai->erase);
 250
 251                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 252                                 av->last_data_size = \
 253                                         be32_to_cpu(new_vh->data_size);
 254
 255                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 256                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 257
 258                         aeb->ec = new_aeb->ec;
 259                         aeb->pnum = new_aeb->pnum;
 260                         aeb->copy_flag = new_vh->copy_flag;
 261                         aeb->scrub = new_aeb->scrub;
 262                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 263
 264                 /* new_aeb is older */
 265                 } else {
 266                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 267                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 268                         list_add_tail(&new_aeb->u.list, &ai->erase);
 269                 }
 270
 271                 return 0;
 272         }
 273         /* This LEB is new, let's add it to the volume */
 274
 275         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 276                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 277                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 278         }
 279
 280         if (av->vol_type == UBI_STATIC_VOLUME)
 281                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 282
 283         av->leb_count++;
 284
 285         rb_link_node(&new_aeb->u.rb, parent, p);
 286         rb_insert_color(&new_aeb->u.rb, &av->root);
 287
 288         return 0;
 289 }
 290
 291 /**
 292  * process_pool_aeb - we found a non-empty PEB in a pool.
 293  * @ubi: UBI device object
 294  * @ai: attach info object
 295  * @new_vh: the volume header derived from new_aeb
 296  * @new_aeb: the AEB to be examined
 297  *
 298  * Returns 0 on success, < 0 indicates an internal error.
 299  */
 300 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 301                             struct ubi_vid_hdr *new_vh,
 302                             struct ubi_ainf_peb *new_aeb)
 303 {
 304         struct ubi_ainf_volume *av, *tmp_av = NULL;
 305         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 306         int found = 0;
 307
 308         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 309                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 310                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 311
 312                 return 0;
 313         }
 314
 315         /* Find the volume this SEB belongs to */
 316         while (*p) {
 317                 parent = *p;
 318                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 319
 320                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 321                         p = &(*p)->rb_left;
 322                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 323                         p = &(*p)->rb_right;
 324                 else {
 325                         found = 1;
 326                         break;
 327                 }
 328         }
 329
 330         if (found)
 331                 av = tmp_av;
 332         else {
 333                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 334                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 335                 return UBI_BAD_FASTMAP;
 336         }
 337
 338         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 339
 340         return update_vol(ubi, ai, av, new_vh, new_aeb);
 341 }
 342
 343 /**
 344  * unmap_peb - unmap a PEB.
 345  * If fastmap detects a free PEB in the pool it has to check whether
 346  * this PEB has been unmapped after writing the fastmap.
 347  *
 348  * @ai: UBI attach info object
 349  * @pnum: The PEB to be unmapped
 350  */
 351 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 352 {
 353         struct ubi_ainf_volume *av;
 354         struct rb_node *node, *node2;
 355         struct ubi_ainf_peb *aeb;
 356
 357         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 358                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 359
 360                 for (node2 = rb_first(&av->root); node2;
 361                      node2 = rb_next(node2)) {
 362                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 363                         if (aeb->pnum == pnum) {
 364                                 rb_erase(&aeb->u.rb, &av->root);
 365                                 av->leb_count--;
 366                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 367                                 return;
 368                         }
 369                 }
 370         }
 371 }
 372
 373 /**
 374  * scan_pool - scans a pool for changed (no longer empty PEBs).
 375  * @ubi: UBI device object
 376  * @ai: attach info object
 377  * @pebs: an array of all PEB numbers in the to be scanned pool
 378  * @pool_size: size of the pool (number of entries in @pebs)
 379  * @max_sqnum: pointer to the maximal sequence number
 380  * @free: list of PEBs which are most likely free (and go into @ai->free)
 381  *
 382  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 383  * < 0 indicates an internal error.
 384  */
 385 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 386                      int *pebs, int pool_size, unsigned long long *max_sqnum,
 387                      struct list_head *free)
 388 {
 389         struct ubi_vid_hdr *vh;
 390         struct ubi_ec_hdr *ech;
 391         struct ubi_ainf_peb *new_aeb;
 392         int i, pnum, err, ret = 0;
 393
 394         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 395         if (!ech)
 396                 return -ENOMEM;
 397
 398         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 399         if (!vh) {
 400                 kfree(ech);
 401                 return -ENOMEM;
 402         }
 403
 404         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 405
 406         /*
 407          * Now scan all PEBs in the pool to find changes which have been made
 408          * after the creation of the fastmap
 409          */
 410         for (i = 0; i < pool_size; i++) {
 411                 int scrub = 0;
 412                 int image_seq;
 413
 414                 pnum = be32_to_cpu(pebs[i]);
 415
 416                 if (ubi_io_is_bad(ubi, pnum)) {
 417                         ubi_err(ubi, "bad PEB in fastmap pool!");
 418                         ret = UBI_BAD_FASTMAP;
 419                         goto out;
 420                 }
 421
 422                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 423                 if (err && err != UBI_IO_BITFLIPS) {
 424                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 425                                 pnum, err);
 426                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 427                         goto out;
 428                 } else if (err == UBI_IO_BITFLIPS)
 429                         scrub = 1;
 430
 431                 /*
 432                  * Older UBI implementations have image_seq set to zero, so
 433                  * we shouldn't fail if image_seq == 0.
 434                  */
 435                 image_seq = be32_to_cpu(ech->image_seq);
 436
 437                 if (image_seq && (image_seq != ubi->image_seq)) {
 438                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 439                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 440                         ret = UBI_BAD_FASTMAP;
 441                         goto out;
 442                 }
 443
 444                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 445                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 446                         unsigned long long ec = be64_to_cpu(ech->ec);
 447                         unmap_peb(ai, pnum);
 448                         dbg_bld("Adding PEB to free: %i", pnum);
 449                         if (err == UBI_IO_FF_BITFLIPS)
 450                                 add_aeb(ai, free, pnum, ec, 1);
 451                         else
 452                                 add_aeb(ai, free, pnum, ec, 0);
 453                         continue;
 454                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 455                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 456
 457                         if (err == UBI_IO_BITFLIPS)
 458                                 scrub = 1;
 459
 460                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 461                                                    GFP_KERNEL);
 462                         if (!new_aeb) {
 463                                 ret = -ENOMEM;
 464                                 goto out;
 465                         }
 466
 467                         new_aeb->ec = be64_to_cpu(ech->ec);
 468                         new_aeb->pnum = pnum;
 469                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 470                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 471                         new_aeb->copy_flag = vh->copy_flag;
 472                         new_aeb->scrub = scrub;
 473
 474                         if (*max_sqnum < new_aeb->sqnum)
 475                                 *max_sqnum = new_aeb->sqnum;
 476
 477                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 478                         if (err) {
 479                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 480                                 goto out;
 481                         }
 482                 } else {
 483                         /* We are paranoid and fall back to scanning mode */
 484                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 485                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 486                         goto out;
 487                 }
 488
 489         }
 490
 491 out:
 492         ubi_free_vid_hdr(ubi, vh);
 493         kfree(ech);
 494         return ret;
 495 }
 496
 497 /**
 498  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 499  * @ai: The UBI attach info object
 500  */
 501 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 502 {
 503         struct ubi_ainf_peb *aeb;
 504         struct ubi_ainf_volume *av;
 505         struct rb_node *rb1, *rb2;
 506         int n = 0;
 507
 508         list_for_each_entry(aeb, &ai->erase, u.list)
 509                 n++;
 510
 511         list_for_each_entry(aeb, &ai->free, u.list)
 512                 n++;
 513
 514          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 515                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 516                         n++;
 517
 518         return n;
 519 }
 520
 521 /**
 522  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 523  * @ubi: UBI device object
 524  * @ai: UBI attach info object
 525  * @fm: the fastmap to be attached
 526  *
 527  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 528  * < 0 indicates an internal error.
 529  */
 530 static int ubi_attach_fastmap(struct ubi_device *ubi,
 531                               struct ubi_attach_info *ai,
 532                               struct ubi_fastmap_layout *fm)
 533 {
 534         struct list_head used, free;
 535         struct ubi_ainf_volume *av;
 536         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 537         struct ubi_fm_sb *fmsb;
 538         struct ubi_fm_hdr *fmhdr;
 539         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 540         struct ubi_fm_ec *fmec;
 541         struct ubi_fm_volhdr *fmvhdr;
 542         struct ubi_fm_eba *fm_eba;
 543         int ret, i, j, pool_size, wl_pool_size;
 544         size_t fm_pos = 0, fm_size = ubi->fm_size;
 545         unsigned long long max_sqnum = 0;
 546         void *fm_raw = ubi->fm_buf;
 547
 548         INIT_LIST_HEAD(&used);
 549         INIT_LIST_HEAD(&free);
 550         ai->min_ec = UBI_MAX_ERASECOUNTER;
 551
 552         fmsb = (struct ubi_fm_sb *)(fm_raw);
 553         ai->max_sqnum = fmsb->sqnum;
 554         fm_pos += sizeof(struct ubi_fm_sb);
 555         if (fm_pos >= fm_size)
 556                 goto fail_bad;
 557
 558         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 559         fm_pos += sizeof(*fmhdr);
 560         if (fm_pos >= fm_size)
 561                 goto fail_bad;
 562
 563         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 564                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 565                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 566                 goto fail_bad;
 567         }
 568
 569         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 570         fm_pos += sizeof(*fmpl1);
 571         if (fm_pos >= fm_size)
 572                 goto fail_bad;
 573         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 574                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 575                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 576                 goto fail_bad;
 577         }
 578
 579         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 580         fm_pos += sizeof(*fmpl2);
 581         if (fm_pos >= fm_size)
 582                 goto fail_bad;
 583         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 584                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 585                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 586                 goto fail_bad;
 587         }
 588
 589         pool_size = be16_to_cpu(fmpl1->size);
 590         wl_pool_size = be16_to_cpu(fmpl2->size);
 591         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 592         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 593
 594         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 595                 ubi_err(ubi, "bad pool size: %i", pool_size);
 596                 goto fail_bad;
 597         }
 598
 599         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 600                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 601                 goto fail_bad;
 602         }
 603
 604
 605         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 606             fm->max_pool_size < 0) {
 607                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 608                 goto fail_bad;
 609         }
 610
 611         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 612             fm->max_wl_pool_size < 0) {
 613                 ubi_err(ubi, "bad maximal WL pool size: %i",
 614                         fm->max_wl_pool_size);
 615                 goto fail_bad;
 616         }
 617
 618         /* read EC values from free list */
 619         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 620                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 621                 fm_pos += sizeof(*fmec);
 622                 if (fm_pos >= fm_size)
 623                         goto fail_bad;
 624
 625                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 626                         be32_to_cpu(fmec->ec), 0);
 627         }
 628
 629         /* read EC values from used list */
 630         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 631                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 632                 fm_pos += sizeof(*fmec);
 633                 if (fm_pos >= fm_size)
 634                         goto fail_bad;
 635
 636                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 637                         be32_to_cpu(fmec->ec), 0);
 638         }
 639
 640         /* read EC values from scrub list */
 641         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 642                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 643                 fm_pos += sizeof(*fmec);
 644                 if (fm_pos >= fm_size)
 645                         goto fail_bad;
 646
 647                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 648                         be32_to_cpu(fmec->ec), 1);
 649         }
 650
 651         /* read EC values from erase list */
 652         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 653                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 654                 fm_pos += sizeof(*fmec);
 655                 if (fm_pos >= fm_size)
 656                         goto fail_bad;
 657
 658                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 659                         be32_to_cpu(fmec->ec), 1);
 660         }
 661
 662         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 663         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 664
 665         /* Iterate over all volumes and read their EBA table */
 666         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 667                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 668                 fm_pos += sizeof(*fmvhdr);
 669                 if (fm_pos >= fm_size)
 670                         goto fail_bad;
 671
 672                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 673                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 674                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 675                         goto fail_bad;
 676                 }
 677
 678                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 679                              be32_to_cpu(fmvhdr->used_ebs),
 680                              be32_to_cpu(fmvhdr->data_pad),
 681                              fmvhdr->vol_type,
 682                              be32_to_cpu(fmvhdr->last_eb_bytes));
 683
 684                 if (!av)
 685                         goto fail_bad;
 686
 687                 ai->vols_found++;
 688                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 689                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 690
 691                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 692                 fm_pos += sizeof(*fm_eba);
 693                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 694                 if (fm_pos >= fm_size)
 695                         goto fail_bad;
 696
 697                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 698                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 699                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 700                         goto fail_bad;
 701                 }
 702
 703                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 704                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 705
 706                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 707                                 continue;
 708
 709                         aeb = NULL;
 710                         list_for_each_entry(tmp_aeb, &used, u.list) {
 711                                 if (tmp_aeb->pnum == pnum) {
 712                                         aeb = tmp_aeb;
 713                                         break;
 714                                 }
 715                         }
 716
 717                         if (!aeb) {
 718                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 719                                 goto fail_bad;
 720                         }
 721
 722                         aeb->lnum = j;
 723
 724                         if (av->highest_lnum <= aeb->lnum)
 725                                 av->highest_lnum = aeb->lnum;
 726
 727                         assign_aeb_to_av(ai, aeb, av);
 728
 729                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 730                                 aeb->pnum, aeb->lnum, av->vol_id);
 731                 }
 732         }
 733
 734         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum, &free);
 735         if (ret)
 736                 goto fail;
 737
 738         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum, &free);
 739         if (ret)
 740                 goto fail;
 741
 742         if (max_sqnum > ai->max_sqnum)
 743                 ai->max_sqnum = max_sqnum;
 744
 745         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 746                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 747
 748         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 749                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 750
 751         ubi_assert(list_empty(&free));
 752
 753         /*
 754          * If fastmap is leaking PEBs (must not happen), raise a
 755          * fat warning and fall back to scanning mode.
 756          * We do this here because in ubi_wl_init() it's too late
 757          * and we cannot fall back to scanning.
 758          */
 759         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 760                     ai->bad_peb_count - fm->used_blocks))
 761                 goto fail_bad;
 762
 763         return 0;
 764
 765 fail_bad:
 766         ret = UBI_BAD_FASTMAP;
 767 fail:
 768         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 769                 list_del(&tmp_aeb->u.list);
 770                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 771         }
 772         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 773                 list_del(&tmp_aeb->u.list);
 774                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 775         }
 776
 777         return ret;
 778 }
 779
 780 /**
 781  * ubi_scan_fastmap - scan the fastmap.
 782  * @ubi: UBI device object
 783  * @ai: UBI attach info to be filled
 784  * @fm_anchor: The fastmap starts at this PEB
 785  *
 786  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 787  * UBI_BAD_FASTMAP if one was found but is not usable.
 788  * < 0 indicates an internal error.
 789  */
 790 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 791                      int fm_anchor)
 792 {
 793         struct ubi_fm_sb *fmsb, *fmsb2;
 794         struct ubi_vid_hdr *vh;
 795         struct ubi_ec_hdr *ech;
 796         struct ubi_fastmap_layout *fm;
 797         int i, used_blocks, pnum, ret = 0;
 798         size_t fm_size;
 799         __be32 crc, tmp_crc;
 800         unsigned long long sqnum = 0;
 801
 802         mutex_lock(&ubi->fm_mutex);
 803         memset(ubi->fm_buf, 0, ubi->fm_size);
 804
 805         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 806         if (!fmsb) {
 807                 ret = -ENOMEM;
 808                 goto out;
 809         }
 810
 811         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 812         if (!fm) {
 813                 ret = -ENOMEM;
 814                 kfree(fmsb);
 815                 goto out;
 816         }
 817
 818         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 819         if (ret && ret != UBI_IO_BITFLIPS)
 820                 goto free_fm_sb;
 821         else if (ret == UBI_IO_BITFLIPS)
 822                 fm->to_be_tortured[0] = 1;
 823
 824         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 825                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 826                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 827                 ret = UBI_BAD_FASTMAP;
 828                 goto free_fm_sb;
 829         }
 830
 831         if (fmsb->version != UBI_FM_FMT_VERSION) {
 832                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 833                         fmsb->version, UBI_FM_FMT_VERSION);
 834                 ret = UBI_BAD_FASTMAP;
 835                 goto free_fm_sb;
 836         }
 837
 838         used_blocks = be32_to_cpu(fmsb->used_blocks);
 839         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 840                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 841                         used_blocks);
 842                 ret = UBI_BAD_FASTMAP;
 843                 goto free_fm_sb;
 844         }
 845
 846         fm_size = ubi->leb_size * used_blocks;
 847         if (fm_size != ubi->fm_size) {
 848                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 849                         fm_size, ubi->fm_size);
 850                 ret = UBI_BAD_FASTMAP;
 851                 goto free_fm_sb;
 852         }
 853
 854         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 855         if (!ech) {
 856                 ret = -ENOMEM;
 857                 goto free_fm_sb;
 858         }
 859
 860         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 861         if (!vh) {
 862                 ret = -ENOMEM;
 863                 goto free_hdr;
 864         }
 865
 866         for (i = 0; i < used_blocks; i++) {
 867                 int image_seq;
 868
 869                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 870
 871                 if (ubi_io_is_bad(ubi, pnum)) {
 872                         ret = UBI_BAD_FASTMAP;
 873                         goto free_hdr;
 874                 }
 875
 876                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 877                 if (ret && ret != UBI_IO_BITFLIPS) {
 878                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 879                                 i, pnum);
 880                         if (ret > 0)
 881                                 ret = UBI_BAD_FASTMAP;
 882                         goto free_hdr;
 883                 } else if (ret == UBI_IO_BITFLIPS)
 884                         fm->to_be_tortured[i] = 1;
 885
 886                 image_seq = be32_to_cpu(ech->image_seq);
 887                 if (!ubi->image_seq)
 888                         ubi->image_seq = image_seq;
 889
 890                 /*
 891                  * Older UBI implementations have image_seq set to zero, so
 892                  * we shouldn't fail if image_seq == 0.
 893                  */
 894                 if (image_seq && (image_seq != ubi->image_seq)) {
 895                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 896                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 897                         ret = UBI_BAD_FASTMAP;
 898                         goto free_hdr;
 899                 }
 900
 901                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 902                 if (ret && ret != UBI_IO_BITFLIPS) {
 903                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 904                                 i, pnum);
 905                         goto free_hdr;
 906                 }
 907
 908                 if (i == 0) {
 909                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 910                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 911                                         be32_to_cpu(vh->vol_id),
 912                                         UBI_FM_SB_VOLUME_ID);
 913                                 ret = UBI_BAD_FASTMAP;
 914                                 goto free_hdr;
 915                         }
 916                 } else {
 917                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 918                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 919                                         be32_to_cpu(vh->vol_id),
 920                                         UBI_FM_DATA_VOLUME_ID);
 921                                 ret = UBI_BAD_FASTMAP;
 922                                 goto free_hdr;
 923                         }
 924                 }
 925
 926                 if (sqnum < be64_to_cpu(vh->sqnum))
 927                         sqnum = be64_to_cpu(vh->sqnum);
 928
 929                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
 930                                   ubi->leb_start, ubi->leb_size);
 931                 if (ret && ret != UBI_IO_BITFLIPS) {
 932                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
 933                                 "err: %i)", i, pnum, ret);
 934                         goto free_hdr;
 935                 }
 936         }
 937
 938         kfree(fmsb);
 939         fmsb = NULL;
 940
 941         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
 942         tmp_crc = be32_to_cpu(fmsb2->data_crc);
 943         fmsb2->data_crc = 0;
 944         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
 945         if (crc != tmp_crc) {
 946                 ubi_err(ubi, "fastmap data CRC is invalid");
 947                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
 948                         tmp_crc, crc);
 949                 ret = UBI_BAD_FASTMAP;
 950                 goto free_hdr;
 951         }
 952
 953         fmsb2->sqnum = sqnum;
 954
 955         fm->used_blocks = used_blocks;
 956
 957         ret = ubi_attach_fastmap(ubi, ai, fm);
 958         if (ret) {
 959                 if (ret > 0)
 960                         ret = UBI_BAD_FASTMAP;
 961                 goto free_hdr;
 962         }
 963
 964         for (i = 0; i < used_blocks; i++) {
 965                 struct ubi_wl_entry *e;
 966
 967                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
 968                 if (!e) {
 969                         while (i--)
 970                                 kfree(fm->e[i]);
 971
 972                         ret = -ENOMEM;
 973                         goto free_hdr;
 974                 }
 975
 976                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
 977                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
 978                 fm->e[i] = e;
 979         }
 980
 981         ubi->fm = fm;
 982         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
 983         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
 984         ubi_msg(ubi, "attached by fastmap");
 985         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
 986         ubi_msg(ubi, "fastmap WL pool size: %d",
 987                 ubi->fm_wl_pool.max_size);
 988         ubi->fm_disabled = 0;
 989
 990         ubi_free_vid_hdr(ubi, vh);
 991         kfree(ech);
 992 out:
 993         mutex_unlock(&ubi->fm_mutex);
 994         if (ret == UBI_BAD_FASTMAP)
 995                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
 996         return ret;
 997
 998 free_hdr:
 999         ubi_free_vid_hdr(ubi, vh);
1000         kfree(ech);
1001 free_fm_sb:
1002         kfree(fmsb);
1003         kfree(fm);
1004         goto out;
1005 }
1006
1007 /**
1008  * ubi_write_fastmap - writes a fastmap.
1009  * @ubi: UBI device object
1010  * @new_fm: the to be written fastmap
1011  *
1012  * Returns 0 on success, < 0 indicates an internal error.
1013  */
1014 static int ubi_write_fastmap(struct ubi_device *ubi,
1015                              struct ubi_fastmap_layout *new_fm)
1016 {
1017         size_t fm_pos = 0;
1018         void *fm_raw;
1019         struct ubi_fm_sb *fmsb;
1020         struct ubi_fm_hdr *fmh;
1021         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1022         struct ubi_fm_ec *fec;
1023         struct ubi_fm_volhdr *fvh;
1024         struct ubi_fm_eba *feba;
1025         struct rb_node *node;
1026         struct ubi_wl_entry *wl_e;
1027         struct ubi_volume *vol;
1028         struct ubi_vid_hdr *avhdr, *dvhdr;
1029         struct ubi_work *ubi_wrk;
1030         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1031         int scrub_peb_count, erase_peb_count;
1032
1033         fm_raw = ubi->fm_buf;
1034         memset(ubi->fm_buf, 0, ubi->fm_size);
1035
1036         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1037         if (!avhdr) {
1038                 ret = -ENOMEM;
1039                 goto out;
1040         }
1041
1042         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1043         if (!dvhdr) {
1044                 ret = -ENOMEM;
1045                 goto out_kfree;
1046         }
1047
1048         spin_lock(&ubi->volumes_lock);
1049         spin_lock(&ubi->wl_lock);
1050
1051         fmsb = (struct ubi_fm_sb *)fm_raw;
1052         fm_pos += sizeof(*fmsb);
1053         ubi_assert(fm_pos <= ubi->fm_size);
1054
1055         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1056         fm_pos += sizeof(*fmh);
1057         ubi_assert(fm_pos <= ubi->fm_size);
1058
1059         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1060         fmsb->version = UBI_FM_FMT_VERSION;
1061         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1062         /* the max sqnum will be filled in while *reading* the fastmap */
1063         fmsb->sqnum = 0;
1064
1065         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1066         free_peb_count = 0;
1067         used_peb_count = 0;
1068         scrub_peb_count = 0;
1069         erase_peb_count = 0;
1070         vol_count = 0;
1071
1072         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1073         fm_pos += sizeof(*fmpl1);
1074         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1075         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1076         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1077
1078         for (i = 0; i < ubi->fm_pool.size; i++)
1079                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1080
1081         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1082         fm_pos += sizeof(*fmpl2);
1083         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1084         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1085         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1086
1087         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1088                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1089
1090         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1091                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1092                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1093
1094                 fec->pnum = cpu_to_be32(wl_e->pnum);
1095                 fec->ec = cpu_to_be32(wl_e->ec);
1096
1097                 free_peb_count++;
1098                 fm_pos += sizeof(*fec);
1099                 ubi_assert(fm_pos <= ubi->fm_size);
1100         }
1101         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1102
1103         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1104                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1105                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1106
1107                 fec->pnum = cpu_to_be32(wl_e->pnum);
1108                 fec->ec = cpu_to_be32(wl_e->ec);
1109
1110                 used_peb_count++;
1111                 fm_pos += sizeof(*fec);
1112                 ubi_assert(fm_pos <= ubi->fm_size);
1113         }
1114
1115         for (i = 0; i < UBI_PROT_QUEUE_LEN; i++) {
1116                 list_for_each_entry(wl_e, &ubi->pq[i], u.list) {
1117                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1118
1119                         fec->pnum = cpu_to_be32(wl_e->pnum);
1120                         fec->ec = cpu_to_be32(wl_e->ec);
1121
1122                         used_peb_count++;
1123                         fm_pos += sizeof(*fec);
1124                         ubi_assert(fm_pos <= ubi->fm_size);
1125                 }
1126         }
1127         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1128
1129         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1130                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1131                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1132
1133                 fec->pnum = cpu_to_be32(wl_e->pnum);
1134                 fec->ec = cpu_to_be32(wl_e->ec);
1135
1136                 scrub_peb_count++;
1137                 fm_pos += sizeof(*fec);
1138                 ubi_assert(fm_pos <= ubi->fm_size);
1139         }
1140         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1141
1142
1143         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1144                 if (ubi_is_erase_work(ubi_wrk)) {
1145                         wl_e = ubi_wrk->e;
1146                         ubi_assert(wl_e);
1147
1148                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1149
1150                         fec->pnum = cpu_to_be32(wl_e->pnum);
1151                         fec->ec = cpu_to_be32(wl_e->ec);
1152
1153                         erase_peb_count++;
1154                         fm_pos += sizeof(*fec);
1155                         ubi_assert(fm_pos <= ubi->fm_size);
1156                 }
1157         }
1158         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1159
1160         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1161                 vol = ubi->volumes[i];
1162
1163                 if (!vol)
1164                         continue;
1165
1166                 vol_count++;
1167
1168                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1169                 fm_pos += sizeof(*fvh);
1170                 ubi_assert(fm_pos <= ubi->fm_size);
1171
1172                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1173                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1174                 fvh->vol_type = vol->vol_type;
1175                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1176                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1177                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1178
1179                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1180                         vol->vol_type == UBI_STATIC_VOLUME);
1181
1182                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1183                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1184                 ubi_assert(fm_pos <= ubi->fm_size);
1185
1186                 for (j = 0; j < vol->reserved_pebs; j++)
1187                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1188
1189                 feba->reserved_pebs = cpu_to_be32(j);
1190                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1191         }
1192         fmh->vol_count = cpu_to_be32(vol_count);
1193         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1194
1195         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1196         avhdr->lnum = 0;
1197
1198         spin_unlock(&ubi->wl_lock);
1199         spin_unlock(&ubi->volumes_lock);
1200
1201         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1202         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1203         if (ret) {
1204                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1205                 goto out_kfree;
1206         }
1207
1208         for (i = 0; i < new_fm->used_blocks; i++) {
1209                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1210                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1211         }
1212
1213         fmsb->data_crc = 0;
1214         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1215                                            ubi->fm_size));
1216
1217         for (i = 1; i < new_fm->used_blocks; i++) {
1218                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1219                 dvhdr->lnum = cpu_to_be32(i);
1220                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1221                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1222                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1223                 if (ret) {
1224                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1225                                 new_fm->e[i]->pnum);
1226                         goto out_kfree;
1227                 }
1228         }
1229
1230         for (i = 0; i < new_fm->used_blocks; i++) {
1231                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1232                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1233                 if (ret) {
1234                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1235                                 new_fm->e[i]->pnum);
1236                         goto out_kfree;
1237                 }
1238         }
1239
1240         ubi_assert(new_fm);
1241         ubi->fm = new_fm;
1242
1243         dbg_bld("fastmap written!");
1244
1245 out_kfree:
1246         ubi_free_vid_hdr(ubi, avhdr);
1247         ubi_free_vid_hdr(ubi, dvhdr);
1248 out:
1249         return ret;
1250 }
1251
1252 /**
1253  * erase_block - Manually erase a PEB.
1254  * @ubi: UBI device object
1255  * @pnum: PEB to be erased
1256  *
1257  * Returns the new EC value on success, < 0 indicates an internal error.
1258  */
1259 static int erase_block(struct ubi_device *ubi, int pnum)
1260 {
1261         int ret;
1262         struct ubi_ec_hdr *ec_hdr;
1263         long long ec;
1264
1265         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1266         if (!ec_hdr)
1267                 return -ENOMEM;
1268
1269         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1270         if (ret < 0)
1271                 goto out;
1272         else if (ret && ret != UBI_IO_BITFLIPS) {
1273                 ret = -EINVAL;
1274                 goto out;
1275         }
1276
1277         ret = ubi_io_sync_erase(ubi, pnum, 0);
1278         if (ret < 0)
1279                 goto out;
1280
1281         ec = be64_to_cpu(ec_hdr->ec);
1282         ec += ret;
1283         if (ec > UBI_MAX_ERASECOUNTER) {
1284                 ret = -EINVAL;
1285                 goto out;
1286         }
1287
1288         ec_hdr->ec = cpu_to_be64(ec);
1289         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1290         if (ret < 0)
1291                 goto out;
1292
1293         ret = ec;
1294 out:
1295         kfree(ec_hdr);
1296         return ret;
1297 }
1298
1299 /**
1300  * invalidate_fastmap - destroys a fastmap.
1301  * @ubi: UBI device object
1302  * @fm: the fastmap to be destroyed
1303  *
1304  * Returns 0 on success, < 0 indicates an internal error.
1305  */
1306 static int invalidate_fastmap(struct ubi_device *ubi,
1307                               struct ubi_fastmap_layout *fm)
1308 {
1309         int ret;
1310         struct ubi_vid_hdr *vh;
1311
1312         ret = erase_block(ubi, fm->e[0]->pnum);
1313         if (ret < 0)
1314                 return ret;
1315
1316         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1317         if (!vh)
1318                 return -ENOMEM;
1319
1320         /* deleting the current fastmap SB is not enough, an old SB may exist,
1321          * so create a (corrupted) SB such that fastmap will find it and fall
1322          * back to scanning mode in any case */
1323         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1324         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1325
1326         return ret;
1327 }
1328
1329 /**
1330  * ubi_update_fastmap - will be called by UBI if a volume changes or
1331  * a fastmap pool becomes full.
1332  * @ubi: UBI device object
1333  *
1334  * Returns 0 on success, < 0 indicates an internal error.
1335  */
1336 int ubi_update_fastmap(struct ubi_device *ubi)
1337 {
1338         int ret, i;
1339         struct ubi_fastmap_layout *new_fm, *old_fm;
1340         struct ubi_wl_entry *tmp_e;
1341
1342         mutex_lock(&ubi->fm_mutex);
1343
1344         ubi_refill_pools(ubi);
1345
1346         if (ubi->ro_mode || ubi->fm_disabled) {
1347                 mutex_unlock(&ubi->fm_mutex);
1348                 return 0;
1349         }
1350
1351         ret = ubi_ensure_anchor_pebs(ubi);
1352         if (ret) {
1353                 mutex_unlock(&ubi->fm_mutex);
1354                 return ret;
1355         }
1356
1357         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1358         if (!new_fm) {
1359                 mutex_unlock(&ubi->fm_mutex);
1360                 return -ENOMEM;
1361         }
1362
1363         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1364         old_fm = ubi->fm;
1365         ubi->fm = NULL;
1366
1367         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1368                 ubi_err(ubi, "fastmap too large");
1369                 ret = -ENOSPC;
1370                 goto err;
1371         }
1372
1373         for (i = 1; i < new_fm->used_blocks; i++) {
1374                 spin_lock(&ubi->wl_lock);
1375                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1376                 spin_unlock(&ubi->wl_lock);
1377
1378                 if (!tmp_e && !old_fm) {
1379                         int j;
1380                         ubi_err(ubi, "could not get any free erase block");
1381
1382                         for (j = 1; j < i; j++)
1383                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1384
1385                         ret = -ENOSPC;
1386                         goto err;
1387                 } else if (!tmp_e && old_fm) {
1388                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1389                         if (ret < 0) {
1390                                 int j;
1391
1392                                 for (j = 1; j < i; j++)
1393                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1394                                                           j, 0);
1395
1396                                 ubi_err(ubi, "could not erase old fastmap PEB");
1397                                 goto err;
1398                         }
1399                         new_fm->e[i] = old_fm->e[i];
1400                 } else {
1401                         new_fm->e[i] = tmp_e;
1402
1403                         if (old_fm)
1404                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1405                                                   old_fm->to_be_tortured[i]);
1406                 }
1407         }
1408
1409         spin_lock(&ubi->wl_lock);
1410         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1411         spin_unlock(&ubi->wl_lock);
1412
1413         if (old_fm) {
1414                 /* no fresh anchor PEB was found, reuse the old one */
1415                 if (!tmp_e) {
1416                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1417                         if (ret < 0) {
1418                                 int i;
1419                                 ubi_err(ubi, "could not erase old anchor PEB");
1420
1421                                 for (i = 1; i < new_fm->used_blocks; i++)
1422                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1423                                                           i, 0);
1424                                 goto err;
1425                         }
1426                         new_fm->e[0] = old_fm->e[0];
1427                         new_fm->e[0]->ec = ret;
1428                 } else {
1429                         /* we've got a new anchor PEB, return the old one */
1430                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1431                                           old_fm->to_be_tortured[0]);
1432                         new_fm->e[0] = tmp_e;
1433                 }
1434         } else {
1435                 if (!tmp_e) {
1436                         int i;
1437                         ubi_err(ubi, "could not find any anchor PEB");
1438
1439                         for (i = 1; i < new_fm->used_blocks; i++)
1440                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1441
1442                         ret = -ENOSPC;
1443                         goto err;
1444                 }
1445                 new_fm->e[0] = tmp_e;
1446         }
1447
1448         down_write(&ubi->work_sem);
1449         down_write(&ubi->fm_sem);
1450         ret = ubi_write_fastmap(ubi, new_fm);
1451         up_write(&ubi->fm_sem);
1452         up_write(&ubi->work_sem);
1453
1454         if (ret)
1455                 goto err;
1456
1457 out_unlock:
1458         mutex_unlock(&ubi->fm_mutex);
1459         kfree(old_fm);
1460         return ret;
1461
1462 err:
1463         kfree(new_fm);
1464
1465         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1466
1467         ret = 0;
1468         if (old_fm) {
1469                 ret = invalidate_fastmap(ubi, old_fm);
1470                 if (ret < 0) {
1471                         ubi_err(ubi, "Unable to invalidiate current fastmap!");
1472                         ubi_ro_mode(ubi);
1473                 }
1474                 else if (ret)
1475                         ret = 0;
1476         }
1477         goto out_unlock;
1478 }