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