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                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 366                                 return;
 367                         }
 368                 }
 369         }
 370 }
 371
 372 /**
 373  * scan_pool - scans a pool for changed (no longer empty PEBs).
 374  * @ubi: UBI device object
 375  * @ai: attach info object
 376  * @pebs: an array of all PEB numbers in the to be scanned pool
 377  * @pool_size: size of the pool (number of entries in @pebs)
 378  * @max_sqnum: pointer to the maximal sequence number
 379  * @eba_orphans: list of PEBs which need to be scanned
 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 *eba_orphans, struct list_head *free)
 388 {
 389         struct ubi_vid_hdr *vh;
 390         struct ubi_ec_hdr *ech;
 391         struct ubi_ainf_peb *new_aeb, *tmp_aeb;
 392         int i, pnum, err, found_orphan, 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                         found_orphan = 0;
 461                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
 462                                 if (tmp_aeb->pnum == pnum) {
 463                                         found_orphan = 1;
 464                                         break;
 465                                 }
 466                         }
 467                         if (found_orphan) {
 468                                 list_del(&tmp_aeb->u.list);
 469                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 470                         }
 471
 472                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 473                                                    GFP_KERNEL);
 474                         if (!new_aeb) {
 475                                 ret = -ENOMEM;
 476                                 goto out;
 477                         }
 478
 479                         new_aeb->ec = be64_to_cpu(ech->ec);
 480                         new_aeb->pnum = pnum;
 481                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 482                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 483                         new_aeb->copy_flag = vh->copy_flag;
 484                         new_aeb->scrub = scrub;
 485
 486                         if (*max_sqnum < new_aeb->sqnum)
 487                                 *max_sqnum = new_aeb->sqnum;
 488
 489                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 490                         if (err) {
 491                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 492                                 goto out;
 493                         }
 494                 } else {
 495                         /* We are paranoid and fall back to scanning mode */
 496                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 497                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 498                         goto out;
 499                 }
 500
 501         }
 502
 503 out:
 504         ubi_free_vid_hdr(ubi, vh);
 505         kfree(ech);
 506         return ret;
 507 }
 508
 509 /**
 510  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 511  * @ai: The UBI attach info object
 512  */
 513 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 514 {
 515         struct ubi_ainf_peb *aeb;
 516         struct ubi_ainf_volume *av;
 517         struct rb_node *rb1, *rb2;
 518         int n = 0;
 519
 520         list_for_each_entry(aeb, &ai->erase, u.list)
 521                 n++;
 522
 523         list_for_each_entry(aeb, &ai->free, u.list)
 524                 n++;
 525
 526          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 527                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 528                         n++;
 529
 530         return n;
 531 }
 532
 533 /**
 534  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 535  * @ubi: UBI device object
 536  * @ai: UBI attach info object
 537  * @fm: the fastmap to be attached
 538  *
 539  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 540  * < 0 indicates an internal error.
 541  */
 542 static int ubi_attach_fastmap(struct ubi_device *ubi,
 543                               struct ubi_attach_info *ai,
 544                               struct ubi_fastmap_layout *fm)
 545 {
 546         struct list_head used, eba_orphans, free;
 547         struct ubi_ainf_volume *av;
 548         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 549         struct ubi_ec_hdr *ech;
 550         struct ubi_fm_sb *fmsb;
 551         struct ubi_fm_hdr *fmhdr;
 552         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 553         struct ubi_fm_ec *fmec;
 554         struct ubi_fm_volhdr *fmvhdr;
 555         struct ubi_fm_eba *fm_eba;
 556         int ret, i, j, pool_size, wl_pool_size;
 557         size_t fm_pos = 0, fm_size = ubi->fm_size;
 558         unsigned long long max_sqnum = 0;
 559         void *fm_raw = ubi->fm_buf;
 560
 561         INIT_LIST_HEAD(&used);
 562         INIT_LIST_HEAD(&free);
 563         INIT_LIST_HEAD(&eba_orphans);
 564         ai->min_ec = UBI_MAX_ERASECOUNTER;
 565
 566         fmsb = (struct ubi_fm_sb *)(fm_raw);
 567         ai->max_sqnum = fmsb->sqnum;
 568         fm_pos += sizeof(struct ubi_fm_sb);
 569         if (fm_pos >= fm_size)
 570                 goto fail_bad;
 571
 572         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 573         fm_pos += sizeof(*fmhdr);
 574         if (fm_pos >= fm_size)
 575                 goto fail_bad;
 576
 577         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 578                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 579                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 580                 goto fail_bad;
 581         }
 582
 583         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 584         fm_pos += sizeof(*fmpl1);
 585         if (fm_pos >= fm_size)
 586                 goto fail_bad;
 587         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 588                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 589                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 590                 goto fail_bad;
 591         }
 592
 593         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 594         fm_pos += sizeof(*fmpl2);
 595         if (fm_pos >= fm_size)
 596                 goto fail_bad;
 597         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 598                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 599                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 600                 goto fail_bad;
 601         }
 602
 603         pool_size = be16_to_cpu(fmpl1->size);
 604         wl_pool_size = be16_to_cpu(fmpl2->size);
 605         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 606         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 607
 608         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 609                 ubi_err(ubi, "bad pool size: %i", pool_size);
 610                 goto fail_bad;
 611         }
 612
 613         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 614                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 615                 goto fail_bad;
 616         }
 617
 618
 619         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 620             fm->max_pool_size < 0) {
 621                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 622                 goto fail_bad;
 623         }
 624
 625         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 626             fm->max_wl_pool_size < 0) {
 627                 ubi_err(ubi, "bad maximal WL pool size: %i",
 628                         fm->max_wl_pool_size);
 629                 goto fail_bad;
 630         }
 631
 632         /* read EC values from free list */
 633         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 634                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 635                 fm_pos += sizeof(*fmec);
 636                 if (fm_pos >= fm_size)
 637                         goto fail_bad;
 638
 639                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 640                         be32_to_cpu(fmec->ec), 0);
 641         }
 642
 643         /* read EC values from used list */
 644         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 645                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 646                 fm_pos += sizeof(*fmec);
 647                 if (fm_pos >= fm_size)
 648                         goto fail_bad;
 649
 650                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 651                         be32_to_cpu(fmec->ec), 0);
 652         }
 653
 654         /* read EC values from scrub list */
 655         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 656                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 657                 fm_pos += sizeof(*fmec);
 658                 if (fm_pos >= fm_size)
 659                         goto fail_bad;
 660
 661                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 662                         be32_to_cpu(fmec->ec), 1);
 663         }
 664
 665         /* read EC values from erase list */
 666         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 667                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 668                 fm_pos += sizeof(*fmec);
 669                 if (fm_pos >= fm_size)
 670                         goto fail_bad;
 671
 672                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 673                         be32_to_cpu(fmec->ec), 1);
 674         }
 675
 676         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 677         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 678
 679         /* Iterate over all volumes and read their EBA table */
 680         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 681                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 682                 fm_pos += sizeof(*fmvhdr);
 683                 if (fm_pos >= fm_size)
 684                         goto fail_bad;
 685
 686                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 687                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 688                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 689                         goto fail_bad;
 690                 }
 691
 692                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 693                              be32_to_cpu(fmvhdr->used_ebs),
 694                              be32_to_cpu(fmvhdr->data_pad),
 695                              fmvhdr->vol_type,
 696                              be32_to_cpu(fmvhdr->last_eb_bytes));
 697
 698                 if (!av)
 699                         goto fail_bad;
 700
 701                 ai->vols_found++;
 702                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 703                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 704
 705                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 706                 fm_pos += sizeof(*fm_eba);
 707                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 708                 if (fm_pos >= fm_size)
 709                         goto fail_bad;
 710
 711                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 712                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 713                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 714                         goto fail_bad;
 715                 }
 716
 717                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 718                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 719
 720                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 721                                 continue;
 722
 723                         aeb = NULL;
 724                         list_for_each_entry(tmp_aeb, &used, u.list) {
 725                                 if (tmp_aeb->pnum == pnum) {
 726                                         aeb = tmp_aeb;
 727                                         break;
 728                                 }
 729                         }
 730
 731                         /* This can happen if a PEB is already in an EBA known
 732                          * by this fastmap but the PEB itself is not in the used
 733                          * list.
 734                          * In this case the PEB can be within the fastmap pool
 735                          * or while writing the fastmap it was in the protection
 736                          * queue.
 737                          */
 738                         if (!aeb) {
 739                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 740                                                        GFP_KERNEL);
 741                                 if (!aeb) {
 742                                         ret = -ENOMEM;
 743
 744                                         goto fail;
 745                                 }
 746
 747                                 aeb->lnum = j;
 748                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 749                                 aeb->ec = -1;
 750                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 751                                 list_add_tail(&aeb->u.list, &eba_orphans);
 752                                 continue;
 753                         }
 754
 755                         aeb->lnum = j;
 756
 757                         if (av->highest_lnum <= aeb->lnum)
 758                                 av->highest_lnum = aeb->lnum;
 759
 760                         assign_aeb_to_av(ai, aeb, av);
 761
 762                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 763                                 aeb->pnum, aeb->lnum, av->vol_id);
 764                 }
 765
 766                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 767                 if (!ech) {
 768                         ret = -ENOMEM;
 769                         goto fail;
 770                 }
 771
 772                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 773                                          u.list) {
 774                         int err;
 775
 776                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 777                                 ubi_err(ubi, "bad PEB in fastmap EBA orphan list");
 778                                 ret = UBI_BAD_FASTMAP;
 779                                 kfree(ech);
 780                                 goto fail;
 781                         }
 782
 783                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 784                         if (err && err != UBI_IO_BITFLIPS) {
 785                                 ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 786                                         tmp_aeb->pnum, err);
 787                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 788                                 kfree(ech);
 789
 790                                 goto fail;
 791                         } else if (err == UBI_IO_BITFLIPS)
 792                                 tmp_aeb->scrub = 1;
 793
 794                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 795                         assign_aeb_to_av(ai, tmp_aeb, av);
 796                 }
 797
 798                 kfree(ech);
 799         }
 800
 801         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 802                         &eba_orphans, &free);
 803         if (ret)
 804                 goto fail;
 805
 806         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 807                         &eba_orphans, &free);
 808         if (ret)
 809                 goto fail;
 810
 811         if (max_sqnum > ai->max_sqnum)
 812                 ai->max_sqnum = max_sqnum;
 813
 814         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 815                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 816
 817         ubi_assert(list_empty(&used));
 818         ubi_assert(list_empty(&eba_orphans));
 819         ubi_assert(list_empty(&free));
 820
 821         /*
 822          * If fastmap is leaking PEBs (must not happen), raise a
 823          * fat warning and fall back to scanning mode.
 824          * We do this here because in ubi_wl_init() it's too late
 825          * and we cannot fall back to scanning.
 826          */
 827         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 828                     ai->bad_peb_count - fm->used_blocks))
 829                 goto fail_bad;
 830
 831         return 0;
 832
 833 fail_bad:
 834         ret = UBI_BAD_FASTMAP;
 835 fail:
 836         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 837                 list_del(&tmp_aeb->u.list);
 838                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 839         }
 840         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
 841                 list_del(&tmp_aeb->u.list);
 842                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 843         }
 844         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 845                 list_del(&tmp_aeb->u.list);
 846                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 847         }
 848
 849         return ret;
 850 }
 851
 852 /**
 853  * ubi_scan_fastmap - scan the fastmap.
 854  * @ubi: UBI device object
 855  * @ai: UBI attach info to be filled
 856  * @fm_anchor: The fastmap starts at this PEB
 857  *
 858  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 859  * UBI_BAD_FASTMAP if one was found but is not usable.
 860  * < 0 indicates an internal error.
 861  */
 862 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 863                      int fm_anchor)
 864 {
 865         struct ubi_fm_sb *fmsb, *fmsb2;
 866         struct ubi_vid_hdr *vh;
 867         struct ubi_ec_hdr *ech;
 868         struct ubi_fastmap_layout *fm;
 869         int i, used_blocks, pnum, ret = 0;
 870         size_t fm_size;
 871         __be32 crc, tmp_crc;
 872         unsigned long long sqnum = 0;
 873
 874         mutex_lock(&ubi->fm_mutex);
 875         memset(ubi->fm_buf, 0, ubi->fm_size);
 876
 877         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 878         if (!fmsb) {
 879                 ret = -ENOMEM;
 880                 goto out;
 881         }
 882
 883         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 884         if (!fm) {
 885                 ret = -ENOMEM;
 886                 kfree(fmsb);
 887                 goto out;
 888         }
 889
 890         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 891         if (ret && ret != UBI_IO_BITFLIPS)
 892                 goto free_fm_sb;
 893         else if (ret == UBI_IO_BITFLIPS)
 894                 fm->to_be_tortured[0] = 1;
 895
 896         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 897                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 898                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 899                 ret = UBI_BAD_FASTMAP;
 900                 goto free_fm_sb;
 901         }
 902
 903         if (fmsb->version != UBI_FM_FMT_VERSION) {
 904                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 905                         fmsb->version, UBI_FM_FMT_VERSION);
 906                 ret = UBI_BAD_FASTMAP;
 907                 goto free_fm_sb;
 908         }
 909
 910         used_blocks = be32_to_cpu(fmsb->used_blocks);
 911         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 912                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 913                         used_blocks);
 914                 ret = UBI_BAD_FASTMAP;
 915                 goto free_fm_sb;
 916         }
 917
 918         fm_size = ubi->leb_size * used_blocks;
 919         if (fm_size != ubi->fm_size) {
 920                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 921                         fm_size, ubi->fm_size);
 922                 ret = UBI_BAD_FASTMAP;
 923                 goto free_fm_sb;
 924         }
 925
 926         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 927         if (!ech) {
 928                 ret = -ENOMEM;
 929                 goto free_fm_sb;
 930         }
 931
 932         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 933         if (!vh) {
 934                 ret = -ENOMEM;
 935                 goto free_hdr;
 936         }
 937
 938         for (i = 0; i < used_blocks; i++) {
 939                 int image_seq;
 940
 941                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 942
 943                 if (ubi_io_is_bad(ubi, pnum)) {
 944                         ret = UBI_BAD_FASTMAP;
 945                         goto free_hdr;
 946                 }
 947
 948                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 949                 if (ret && ret != UBI_IO_BITFLIPS) {
 950                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 951                                 i, pnum);
 952                         if (ret > 0)
 953                                 ret = UBI_BAD_FASTMAP;
 954                         goto free_hdr;
 955                 } else if (ret == UBI_IO_BITFLIPS)
 956                         fm->to_be_tortured[i] = 1;
 957
 958                 image_seq = be32_to_cpu(ech->image_seq);
 959                 if (!ubi->image_seq)
 960                         ubi->image_seq = image_seq;
 961
 962                 /*
 963                  * Older UBI implementations have image_seq set to zero, so
 964                  * we shouldn't fail if image_seq == 0.
 965                  */
 966                 if (image_seq && (image_seq != ubi->image_seq)) {
 967                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 968                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 969                         ret = UBI_BAD_FASTMAP;
 970                         goto free_hdr;
 971                 }
 972
 973                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 974                 if (ret && ret != UBI_IO_BITFLIPS) {
 975                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 976                                 i, pnum);
 977                         goto free_hdr;
 978                 }
 979
 980                 if (i == 0) {
 981                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 982                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 983                                         be32_to_cpu(vh->vol_id),
 984                                         UBI_FM_SB_VOLUME_ID);
 985                                 ret = UBI_BAD_FASTMAP;
 986                                 goto free_hdr;
 987                         }
 988                 } else {
 989                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
 990                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, expected: 0x%x",
 991                                         be32_to_cpu(vh->vol_id),
 992                                         UBI_FM_DATA_VOLUME_ID);
 993                                 ret = UBI_BAD_FASTMAP;
 994                                 goto free_hdr;
 995                         }
 996                 }
 997
 998                 if (sqnum < be64_to_cpu(vh->sqnum))
 999                         sqnum = be64_to_cpu(vh->sqnum);
1000
1001                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1002                                   ubi->leb_start, ubi->leb_size);
1003                 if (ret && ret != UBI_IO_BITFLIPS) {
1004                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i, "
1005                                 "err: %i)", i, pnum, ret);
1006                         goto free_hdr;
1007                 }
1008         }
1009
1010         kfree(fmsb);
1011         fmsb = NULL;
1012
1013         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1014         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1015         fmsb2->data_crc = 0;
1016         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1017         if (crc != tmp_crc) {
1018                 ubi_err(ubi, "fastmap data CRC is invalid");
1019                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1020                         tmp_crc, crc);
1021                 ret = UBI_BAD_FASTMAP;
1022                 goto free_hdr;
1023         }
1024
1025         fmsb2->sqnum = sqnum;
1026
1027         fm->used_blocks = used_blocks;
1028
1029         ret = ubi_attach_fastmap(ubi, ai, fm);
1030         if (ret) {
1031                 if (ret > 0)
1032                         ret = UBI_BAD_FASTMAP;
1033                 goto free_hdr;
1034         }
1035
1036         for (i = 0; i < used_blocks; i++) {
1037                 struct ubi_wl_entry *e;
1038
1039                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1040                 if (!e) {
1041                         while (i--)
1042                                 kfree(fm->e[i]);
1043
1044                         ret = -ENOMEM;
1045                         goto free_hdr;
1046                 }
1047
1048                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1049                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1050                 fm->e[i] = e;
1051         }
1052
1053         ubi->fm = fm;
1054         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1055         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1056         ubi_msg(ubi, "attached by fastmap");
1057         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1058         ubi_msg(ubi, "fastmap WL pool size: %d",
1059                 ubi->fm_wl_pool.max_size);
1060         ubi->fm_disabled = 0;
1061
1062         ubi_free_vid_hdr(ubi, vh);
1063         kfree(ech);
1064 out:
1065         mutex_unlock(&ubi->fm_mutex);
1066         if (ret == UBI_BAD_FASTMAP)
1067                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1068         return ret;
1069
1070 free_hdr:
1071         ubi_free_vid_hdr(ubi, vh);
1072         kfree(ech);
1073 free_fm_sb:
1074         kfree(fmsb);
1075         kfree(fm);
1076         goto out;
1077 }
1078
1079 /**
1080  * ubi_write_fastmap - writes a fastmap.
1081  * @ubi: UBI device object
1082  * @new_fm: the to be written fastmap
1083  *
1084  * Returns 0 on success, < 0 indicates an internal error.
1085  */
1086 static int ubi_write_fastmap(struct ubi_device *ubi,
1087                              struct ubi_fastmap_layout *new_fm)
1088 {
1089         size_t fm_pos = 0;
1090         void *fm_raw;
1091         struct ubi_fm_sb *fmsb;
1092         struct ubi_fm_hdr *fmh;
1093         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1094         struct ubi_fm_ec *fec;
1095         struct ubi_fm_volhdr *fvh;
1096         struct ubi_fm_eba *feba;
1097         struct rb_node *node;
1098         struct ubi_wl_entry *wl_e;
1099         struct ubi_volume *vol;
1100         struct ubi_vid_hdr *avhdr, *dvhdr;
1101         struct ubi_work *ubi_wrk;
1102         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1103         int scrub_peb_count, erase_peb_count;
1104
1105         fm_raw = ubi->fm_buf;
1106         memset(ubi->fm_buf, 0, ubi->fm_size);
1107
1108         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1109         if (!avhdr) {
1110                 ret = -ENOMEM;
1111                 goto out;
1112         }
1113
1114         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1115         if (!dvhdr) {
1116                 ret = -ENOMEM;
1117                 goto out_kfree;
1118         }
1119
1120         spin_lock(&ubi->volumes_lock);
1121         spin_lock(&ubi->wl_lock);
1122
1123         fmsb = (struct ubi_fm_sb *)fm_raw;
1124         fm_pos += sizeof(*fmsb);
1125         ubi_assert(fm_pos <= ubi->fm_size);
1126
1127         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1128         fm_pos += sizeof(*fmh);
1129         ubi_assert(fm_pos <= ubi->fm_size);
1130
1131         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1132         fmsb->version = UBI_FM_FMT_VERSION;
1133         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1134         /* the max sqnum will be filled in while *reading* the fastmap */
1135         fmsb->sqnum = 0;
1136
1137         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1138         free_peb_count = 0;
1139         used_peb_count = 0;
1140         scrub_peb_count = 0;
1141         erase_peb_count = 0;
1142         vol_count = 0;
1143
1144         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1145         fm_pos += sizeof(*fmpl1);
1146         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1147         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1148         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1149
1150         for (i = 0; i < ubi->fm_pool.size; i++)
1151                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1152
1153         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1154         fm_pos += sizeof(*fmpl2);
1155         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1156         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1157         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1158
1159         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1160                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1161
1162         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1163                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1164                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1165
1166                 fec->pnum = cpu_to_be32(wl_e->pnum);
1167                 fec->ec = cpu_to_be32(wl_e->ec);
1168
1169                 free_peb_count++;
1170                 fm_pos += sizeof(*fec);
1171                 ubi_assert(fm_pos <= ubi->fm_size);
1172         }
1173         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1174
1175         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1176                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1177                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1178
1179                 fec->pnum = cpu_to_be32(wl_e->pnum);
1180                 fec->ec = cpu_to_be32(wl_e->ec);
1181
1182                 used_peb_count++;
1183                 fm_pos += sizeof(*fec);
1184                 ubi_assert(fm_pos <= ubi->fm_size);
1185         }
1186
1187         for (i = 0; i < UBI_PROT_QUEUE_LEN; i++) {
1188                 list_for_each_entry(wl_e, &ubi->pq[i], u.list) {
1189                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1190
1191                         fec->pnum = cpu_to_be32(wl_e->pnum);
1192                         fec->ec = cpu_to_be32(wl_e->ec);
1193
1194                         used_peb_count++;
1195                         fm_pos += sizeof(*fec);
1196                         ubi_assert(fm_pos <= ubi->fm_size);
1197                 }
1198         }
1199         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1200
1201         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1202                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1203                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1204
1205                 fec->pnum = cpu_to_be32(wl_e->pnum);
1206                 fec->ec = cpu_to_be32(wl_e->ec);
1207
1208                 scrub_peb_count++;
1209                 fm_pos += sizeof(*fec);
1210                 ubi_assert(fm_pos <= ubi->fm_size);
1211         }
1212         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1213
1214
1215         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1216                 if (ubi_is_erase_work(ubi_wrk)) {
1217                         wl_e = ubi_wrk->e;
1218                         ubi_assert(wl_e);
1219
1220                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1221
1222                         fec->pnum = cpu_to_be32(wl_e->pnum);
1223                         fec->ec = cpu_to_be32(wl_e->ec);
1224
1225                         erase_peb_count++;
1226                         fm_pos += sizeof(*fec);
1227                         ubi_assert(fm_pos <= ubi->fm_size);
1228                 }
1229         }
1230         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1231
1232         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1233                 vol = ubi->volumes[i];
1234
1235                 if (!vol)
1236                         continue;
1237
1238                 vol_count++;
1239
1240                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1241                 fm_pos += sizeof(*fvh);
1242                 ubi_assert(fm_pos <= ubi->fm_size);
1243
1244                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1245                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1246                 fvh->vol_type = vol->vol_type;
1247                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1248                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1249                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1250
1251                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1252                         vol->vol_type == UBI_STATIC_VOLUME);
1253
1254                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1255                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1256                 ubi_assert(fm_pos <= ubi->fm_size);
1257
1258                 for (j = 0; j < vol->reserved_pebs; j++)
1259                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1260
1261                 feba->reserved_pebs = cpu_to_be32(j);
1262                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1263         }
1264         fmh->vol_count = cpu_to_be32(vol_count);
1265         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1266
1267         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1268         avhdr->lnum = 0;
1269
1270         spin_unlock(&ubi->wl_lock);
1271         spin_unlock(&ubi->volumes_lock);
1272
1273         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1274         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1275         if (ret) {
1276                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1277                 goto out_kfree;
1278         }
1279
1280         for (i = 0; i < new_fm->used_blocks; i++) {
1281                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1282                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1283         }
1284
1285         fmsb->data_crc = 0;
1286         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1287                                            ubi->fm_size));
1288
1289         for (i = 1; i < new_fm->used_blocks; i++) {
1290                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1291                 dvhdr->lnum = cpu_to_be32(i);
1292                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1293                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1294                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1295                 if (ret) {
1296                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1297                                 new_fm->e[i]->pnum);
1298                         goto out_kfree;
1299                 }
1300         }
1301
1302         for (i = 0; i < new_fm->used_blocks; i++) {
1303                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1304                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1305                 if (ret) {
1306                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1307                                 new_fm->e[i]->pnum);
1308                         goto out_kfree;
1309                 }
1310         }
1311
1312         ubi_assert(new_fm);
1313         ubi->fm = new_fm;
1314
1315         dbg_bld("fastmap written!");
1316
1317 out_kfree:
1318         ubi_free_vid_hdr(ubi, avhdr);
1319         ubi_free_vid_hdr(ubi, dvhdr);
1320 out:
1321         return ret;
1322 }
1323
1324 /**
1325  * erase_block - Manually erase a PEB.
1326  * @ubi: UBI device object
1327  * @pnum: PEB to be erased
1328  *
1329  * Returns the new EC value on success, < 0 indicates an internal error.
1330  */
1331 static int erase_block(struct ubi_device *ubi, int pnum)
1332 {
1333         int ret;
1334         struct ubi_ec_hdr *ec_hdr;
1335         long long ec;
1336
1337         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1338         if (!ec_hdr)
1339                 return -ENOMEM;
1340
1341         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1342         if (ret < 0)
1343                 goto out;
1344         else if (ret && ret != UBI_IO_BITFLIPS) {
1345                 ret = -EINVAL;
1346                 goto out;
1347         }
1348
1349         ret = ubi_io_sync_erase(ubi, pnum, 0);
1350         if (ret < 0)
1351                 goto out;
1352
1353         ec = be64_to_cpu(ec_hdr->ec);
1354         ec += ret;
1355         if (ec > UBI_MAX_ERASECOUNTER) {
1356                 ret = -EINVAL;
1357                 goto out;
1358         }
1359
1360         ec_hdr->ec = cpu_to_be64(ec);
1361         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1362         if (ret < 0)
1363                 goto out;
1364
1365         ret = ec;
1366 out:
1367         kfree(ec_hdr);
1368         return ret;
1369 }
1370
1371 /**
1372  * invalidate_fastmap - destroys a fastmap.
1373  * @ubi: UBI device object
1374  * @fm: the fastmap to be destroyed
1375  *
1376  * Returns 0 on success, < 0 indicates an internal error.
1377  */
1378 static int invalidate_fastmap(struct ubi_device *ubi,
1379                               struct ubi_fastmap_layout *fm)
1380 {
1381         int ret;
1382         struct ubi_vid_hdr *vh;
1383
1384         ret = erase_block(ubi, fm->e[0]->pnum);
1385         if (ret < 0)
1386                 return ret;
1387
1388         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1389         if (!vh)
1390                 return -ENOMEM;
1391
1392         /* deleting the current fastmap SB is not enough, an old SB may exist,
1393          * so create a (corrupted) SB such that fastmap will find it and fall
1394          * back to scanning mode in any case */
1395         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1396         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1397
1398         return ret;
1399 }
1400
1401 /**
1402  * ubi_update_fastmap - will be called by UBI if a volume changes or
1403  * a fastmap pool becomes full.
1404  * @ubi: UBI device object
1405  *
1406  * Returns 0 on success, < 0 indicates an internal error.
1407  */
1408 int ubi_update_fastmap(struct ubi_device *ubi)
1409 {
1410         int ret, i;
1411         struct ubi_fastmap_layout *new_fm, *old_fm;
1412         struct ubi_wl_entry *tmp_e;
1413
1414         mutex_lock(&ubi->fm_mutex);
1415
1416         ubi_refill_pools(ubi);
1417
1418         if (ubi->ro_mode || ubi->fm_disabled) {
1419                 mutex_unlock(&ubi->fm_mutex);
1420                 return 0;
1421         }
1422
1423         ret = ubi_ensure_anchor_pebs(ubi);
1424         if (ret) {
1425                 mutex_unlock(&ubi->fm_mutex);
1426                 return ret;
1427         }
1428
1429         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1430         if (!new_fm) {
1431                 mutex_unlock(&ubi->fm_mutex);
1432                 return -ENOMEM;
1433         }
1434
1435         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1436         old_fm = ubi->fm;
1437         ubi->fm = NULL;
1438
1439         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1440                 ubi_err(ubi, "fastmap too large");
1441                 ret = -ENOSPC;
1442                 goto err;
1443         }
1444
1445         for (i = 1; i < new_fm->used_blocks; i++) {
1446                 spin_lock(&ubi->wl_lock);
1447                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1448                 spin_unlock(&ubi->wl_lock);
1449
1450                 if (!tmp_e && !old_fm) {
1451                         int j;
1452                         ubi_err(ubi, "could not get any free erase block");
1453
1454                         for (j = 1; j < i; j++)
1455                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1456
1457                         ret = -ENOSPC;
1458                         goto err;
1459                 } else if (!tmp_e && old_fm) {
1460                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1461                         if (ret < 0) {
1462                                 int j;
1463
1464                                 for (j = 1; j < i; j++)
1465                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1466                                                           j, 0);
1467
1468                                 ubi_err(ubi, "could not erase old fastmap PEB");
1469                                 goto err;
1470                         }
1471                         new_fm->e[i] = old_fm->e[i];
1472                 } else {
1473                         new_fm->e[i] = tmp_e;
1474
1475                         if (old_fm)
1476                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1477                                                   old_fm->to_be_tortured[i]);
1478                 }
1479         }
1480
1481         spin_lock(&ubi->wl_lock);
1482         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1483         spin_unlock(&ubi->wl_lock);
1484
1485         if (old_fm) {
1486                 /* no fresh anchor PEB was found, reuse the old one */
1487                 if (!tmp_e) {
1488                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1489                         if (ret < 0) {
1490                                 int i;
1491                                 ubi_err(ubi, "could not erase old anchor PEB");
1492
1493                                 for (i = 1; i < new_fm->used_blocks; i++)
1494                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1495                                                           i, 0);
1496                                 goto err;
1497                         }
1498                         new_fm->e[0] = old_fm->e[0];
1499                         new_fm->e[0]->ec = ret;
1500                 } else {
1501                         /* we've got a new anchor PEB, return the old one */
1502                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1503                                           old_fm->to_be_tortured[0]);
1504                         new_fm->e[0] = tmp_e;
1505                 }
1506         } else {
1507                 if (!tmp_e) {
1508                         int i;
1509                         ubi_err(ubi, "could not find any anchor PEB");
1510
1511                         for (i = 1; i < new_fm->used_blocks; i++)
1512                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1513
1514                         ret = -ENOSPC;
1515                         goto err;
1516                 }
1517                 new_fm->e[0] = tmp_e;
1518         }
1519
1520         down_write(&ubi->work_sem);
1521         down_write(&ubi->fm_sem);
1522         ret = ubi_write_fastmap(ubi, new_fm);
1523         up_write(&ubi->fm_sem);
1524         up_write(&ubi->work_sem);
1525
1526         if (ret)
1527                 goto err;
1528
1529 out_unlock:
1530         mutex_unlock(&ubi->fm_mutex);
1531         kfree(old_fm);
1532         return ret;
1533
1534 err:
1535         kfree(new_fm);
1536
1537         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1538
1539         ret = 0;
1540         if (old_fm) {
1541                 ret = invalidate_fastmap(ubi, old_fm);
1542                 if (ret < 0)
1543                         ubi_err(ubi, "Unable to invalidiate current fastmap!");
1544                 else if (ret)
1545                         ret = 0;
1546         }
1547         goto out_unlock;
1548 }