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("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("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("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("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("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         INIT_LIST_HEAD(&ai->corr);
 565         INIT_LIST_HEAD(&ai->free);
 566         INIT_LIST_HEAD(&ai->erase);
 567         INIT_LIST_HEAD(&ai->alien);
 568         ai->volumes = RB_ROOT;
 569         ai->min_ec = UBI_MAX_ERASECOUNTER;
 570
 571         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
 572                                                sizeof(struct ubi_ainf_peb),
 573                                                0, 0, NULL);
 574         if (!ai->aeb_slab_cache) {
 575                 ret = -ENOMEM;
 576                 goto fail;
 577         }
 578
 579         fmsb = (struct ubi_fm_sb *)(fm_raw);
 580         ai->max_sqnum = fmsb->sqnum;
 581         fm_pos += sizeof(struct ubi_fm_sb);
 582         if (fm_pos >= fm_size)
 583                 goto fail_bad;
 584
 585         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 586         fm_pos += sizeof(*fmhdr);
 587         if (fm_pos >= fm_size)
 588                 goto fail_bad;
 589
 590         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 591                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
 592                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 593                 goto fail_bad;
 594         }
 595
 596         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 597         fm_pos += sizeof(*fmpl1);
 598         if (fm_pos >= fm_size)
 599                 goto fail_bad;
 600         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 601                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 602                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 603                 goto fail_bad;
 604         }
 605
 606         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 607         fm_pos += sizeof(*fmpl2);
 608         if (fm_pos >= fm_size)
 609                 goto fail_bad;
 610         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 611                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 612                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 613                 goto fail_bad;
 614         }
 615
 616         pool_size = be16_to_cpu(fmpl1->size);
 617         wl_pool_size = be16_to_cpu(fmpl2->size);
 618         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 619         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 620
 621         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 622                 ubi_err("bad pool size: %i", pool_size);
 623                 goto fail_bad;
 624         }
 625
 626         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 627                 ubi_err("bad WL pool size: %i", wl_pool_size);
 628                 goto fail_bad;
 629         }
 630
 631
 632         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 633             fm->max_pool_size < 0) {
 634                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
 635                 goto fail_bad;
 636         }
 637
 638         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 639             fm->max_wl_pool_size < 0) {
 640                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
 641                 goto fail_bad;
 642         }
 643
 644         /* read EC values from free list */
 645         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 646                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 647                 fm_pos += sizeof(*fmec);
 648                 if (fm_pos >= fm_size)
 649                         goto fail_bad;
 650
 651                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 652                         be32_to_cpu(fmec->ec), 0);
 653         }
 654
 655         /* read EC values from used list */
 656         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 657                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 658                 fm_pos += sizeof(*fmec);
 659                 if (fm_pos >= fm_size)
 660                         goto fail_bad;
 661
 662                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 663                         be32_to_cpu(fmec->ec), 0);
 664         }
 665
 666         /* read EC values from scrub list */
 667         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 668                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 669                 fm_pos += sizeof(*fmec);
 670                 if (fm_pos >= fm_size)
 671                         goto fail_bad;
 672
 673                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 674                         be32_to_cpu(fmec->ec), 1);
 675         }
 676
 677         /* read EC values from erase list */
 678         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 679                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 680                 fm_pos += sizeof(*fmec);
 681                 if (fm_pos >= fm_size)
 682                         goto fail_bad;
 683
 684                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 685                         be32_to_cpu(fmec->ec), 1);
 686         }
 687
 688         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 689         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 690
 691         /* Iterate over all volumes and read their EBA table */
 692         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 693                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 694                 fm_pos += sizeof(*fmvhdr);
 695                 if (fm_pos >= fm_size)
 696                         goto fail_bad;
 697
 698                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 699                         ubi_err("bad fastmap vol header magic: 0x%x, " \
 700                                 "expected: 0x%x",
 701                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 702                         goto fail_bad;
 703                 }
 704
 705                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 706                              be32_to_cpu(fmvhdr->used_ebs),
 707                              be32_to_cpu(fmvhdr->data_pad),
 708                              fmvhdr->vol_type,
 709                              be32_to_cpu(fmvhdr->last_eb_bytes));
 710
 711                 if (!av)
 712                         goto fail_bad;
 713
 714                 ai->vols_found++;
 715                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 716                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 717
 718                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 719                 fm_pos += sizeof(*fm_eba);
 720                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 721                 if (fm_pos >= fm_size)
 722                         goto fail_bad;
 723
 724                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 725                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
 726                                 "expected: 0x%x",
 727                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 728                         goto fail_bad;
 729                 }
 730
 731                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 732                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 733
 734                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 735                                 continue;
 736
 737                         aeb = NULL;
 738                         list_for_each_entry(tmp_aeb, &used, u.list) {
 739                                 if (tmp_aeb->pnum == pnum) {
 740                                         aeb = tmp_aeb;
 741                                         break;
 742                                 }
 743                         }
 744
 745                         /* This can happen if a PEB is already in an EBA known
 746                          * by this fastmap but the PEB itself is not in the used
 747                          * list.
 748                          * In this case the PEB can be within the fastmap pool
 749                          * or while writing the fastmap it was in the protection
 750                          * queue.
 751                          */
 752                         if (!aeb) {
 753                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 754                                                        GFP_KERNEL);
 755                                 if (!aeb) {
 756                                         ret = -ENOMEM;
 757
 758                                         goto fail;
 759                                 }
 760
 761                                 aeb->lnum = j;
 762                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 763                                 aeb->ec = -1;
 764                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 765                                 list_add_tail(&aeb->u.list, &eba_orphans);
 766                                 continue;
 767                         }
 768
 769                         aeb->lnum = j;
 770
 771                         if (av->highest_lnum <= aeb->lnum)
 772                                 av->highest_lnum = aeb->lnum;
 773
 774                         assign_aeb_to_av(ai, aeb, av);
 775
 776                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 777                                 aeb->pnum, aeb->lnum, av->vol_id);
 778                 }
 779
 780                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 781                 if (!ech) {
 782                         ret = -ENOMEM;
 783                         goto fail;
 784                 }
 785
 786                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 787                                          u.list) {
 788                         int err;
 789
 790                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 791                                 ubi_err("bad PEB in fastmap EBA orphan list");
 792                                 ret = UBI_BAD_FASTMAP;
 793                                 kfree(ech);
 794                                 goto fail;
 795                         }
 796
 797                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 798                         if (err && err != UBI_IO_BITFLIPS) {
 799                                 ubi_err("unable to read EC header! PEB:%i " \
 800                                         "err:%i", tmp_aeb->pnum, err);
 801                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 802                                 kfree(ech);
 803
 804                                 goto fail;
 805                         } else if (err == UBI_IO_BITFLIPS)
 806                                 tmp_aeb->scrub = 1;
 807
 808                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 809                         assign_aeb_to_av(ai, tmp_aeb, av);
 810                 }
 811
 812                 kfree(ech);
 813         }
 814
 815         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 816                         &eba_orphans, &free);
 817         if (ret)
 818                 goto fail;
 819
 820         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 821                         &eba_orphans, &free);
 822         if (ret)
 823                 goto fail;
 824
 825         if (max_sqnum > ai->max_sqnum)
 826                 ai->max_sqnum = max_sqnum;
 827
 828         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 829                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 830
 831         ubi_assert(list_empty(&used));
 832         ubi_assert(list_empty(&eba_orphans));
 833         ubi_assert(list_empty(&free));
 834
 835         /*
 836          * If fastmap is leaking PEBs (must not happen), raise a
 837          * fat warning and fall back to scanning mode.
 838          * We do this here because in ubi_wl_init() it's too late
 839          * and we cannot fall back to scanning.
 840          */
 841         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 842                     ai->bad_peb_count - fm->used_blocks))
 843                 goto fail_bad;
 844
 845         return 0;
 846
 847 fail_bad:
 848         ret = UBI_BAD_FASTMAP;
 849 fail:
 850         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 851                 list_del(&tmp_aeb->u.list);
 852                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 853         }
 854         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
 855                 list_del(&tmp_aeb->u.list);
 856                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 857         }
 858         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 859                 list_del(&tmp_aeb->u.list);
 860                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 861         }
 862
 863         return ret;
 864 }
 865
 866 /**
 867  * ubi_scan_fastmap - scan the fastmap.
 868  * @ubi: UBI device object
 869  * @ai: UBI attach info to be filled
 870  * @fm_anchor: The fastmap starts at this PEB
 871  *
 872  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 873  * UBI_BAD_FASTMAP if one was found but is not usable.
 874  * < 0 indicates an internal error.
 875  */
 876 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 877                      int fm_anchor)
 878 {
 879         struct ubi_fm_sb *fmsb, *fmsb2;
 880         struct ubi_vid_hdr *vh;
 881         struct ubi_ec_hdr *ech;
 882         struct ubi_fastmap_layout *fm;
 883         int i, used_blocks, pnum, ret = 0;
 884         size_t fm_size;
 885         __be32 crc, tmp_crc;
 886         unsigned long long sqnum = 0;
 887
 888         mutex_lock(&ubi->fm_mutex);
 889         memset(ubi->fm_buf, 0, ubi->fm_size);
 890
 891         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 892         if (!fmsb) {
 893                 ret = -ENOMEM;
 894                 goto out;
 895         }
 896
 897         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 898         if (!fm) {
 899                 ret = -ENOMEM;
 900                 kfree(fmsb);
 901                 goto out;
 902         }
 903
 904         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 905         if (ret && ret != UBI_IO_BITFLIPS)
 906                 goto free_fm_sb;
 907         else if (ret == UBI_IO_BITFLIPS)
 908                 fm->to_be_tortured[0] = 1;
 909
 910         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 911                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
 912                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 913                 ret = UBI_BAD_FASTMAP;
 914                 goto free_fm_sb;
 915         }
 916
 917         if (fmsb->version != UBI_FM_FMT_VERSION) {
 918                 ubi_err("bad fastmap version: %i, expected: %i",
 919                         fmsb->version, UBI_FM_FMT_VERSION);
 920                 ret = UBI_BAD_FASTMAP;
 921                 goto free_fm_sb;
 922         }
 923
 924         used_blocks = be32_to_cpu(fmsb->used_blocks);
 925         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 926                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
 927                 ret = UBI_BAD_FASTMAP;
 928                 goto free_fm_sb;
 929         }
 930
 931         fm_size = ubi->leb_size * used_blocks;
 932         if (fm_size != ubi->fm_size) {
 933                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
 934                         ubi->fm_size);
 935                 ret = UBI_BAD_FASTMAP;
 936                 goto free_fm_sb;
 937         }
 938
 939         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 940         if (!ech) {
 941                 ret = -ENOMEM;
 942                 goto free_fm_sb;
 943         }
 944
 945         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 946         if (!vh) {
 947                 ret = -ENOMEM;
 948                 goto free_hdr;
 949         }
 950
 951         for (i = 0; i < used_blocks; i++) {
 952                 int image_seq;
 953
 954                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 955
 956                 if (ubi_io_is_bad(ubi, pnum)) {
 957                         ret = UBI_BAD_FASTMAP;
 958                         goto free_hdr;
 959                 }
 960
 961                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 962                 if (ret && ret != UBI_IO_BITFLIPS) {
 963                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
 964                                 i, pnum);
 965                         if (ret > 0)
 966                                 ret = UBI_BAD_FASTMAP;
 967                         goto free_hdr;
 968                 } else if (ret == UBI_IO_BITFLIPS)
 969                         fm->to_be_tortured[i] = 1;
 970
 971                 image_seq = be32_to_cpu(ech->image_seq);
 972                 if (!ubi->image_seq)
 973                         ubi->image_seq = image_seq;
 974
 975                 /*
 976                  * Older UBI implementations have image_seq set to zero, so
 977                  * we shouldn't fail if image_seq == 0.
 978                  */
 979                 if (image_seq && (image_seq != ubi->image_seq)) {
 980                         ubi_err("wrong image seq:%d instead of %d",
 981                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 982                         ret = UBI_BAD_FASTMAP;
 983                         goto free_hdr;
 984                 }
 985
 986                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 987                 if (ret && ret != UBI_IO_BITFLIPS) {
 988                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
 989                                 i, pnum);
 990                         goto free_hdr;
 991                 }
 992
 993                 if (i == 0) {
 994                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 995                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
 996                                         " expected: 0x%x",
 997                                         be32_to_cpu(vh->vol_id),
 998                                         UBI_FM_SB_VOLUME_ID);
 999                                 ret = UBI_BAD_FASTMAP;
1000                                 goto free_hdr;
1001                         }
1002                 } else {
1003                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1004                                 ubi_err("bad fastmap data vol_id: 0x%x," \
1005                                         " expected: 0x%x",
1006                                         be32_to_cpu(vh->vol_id),
1007                                         UBI_FM_DATA_VOLUME_ID);
1008                                 ret = UBI_BAD_FASTMAP;
1009                                 goto free_hdr;
1010                         }
1011                 }
1012
1013                 if (sqnum < be64_to_cpu(vh->sqnum))
1014                         sqnum = be64_to_cpu(vh->sqnum);
1015
1016                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1017                                   ubi->leb_start, ubi->leb_size);
1018                 if (ret && ret != UBI_IO_BITFLIPS) {
1019                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
1020                                 "err: %i)", i, pnum, ret);
1021                         goto free_hdr;
1022                 }
1023         }
1024
1025         kfree(fmsb);
1026         fmsb = NULL;
1027
1028         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1029         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1030         fmsb2->data_crc = 0;
1031         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1032         if (crc != tmp_crc) {
1033                 ubi_err("fastmap data CRC is invalid");
1034                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1035                 ret = UBI_BAD_FASTMAP;
1036                 goto free_hdr;
1037         }
1038
1039         fmsb2->sqnum = sqnum;
1040
1041         fm->used_blocks = used_blocks;
1042
1043         ret = ubi_attach_fastmap(ubi, ai, fm);
1044         if (ret) {
1045                 if (ret > 0)
1046                         ret = UBI_BAD_FASTMAP;
1047                 goto free_hdr;
1048         }
1049
1050         for (i = 0; i < used_blocks; i++) {
1051                 struct ubi_wl_entry *e;
1052
1053                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1054                 if (!e) {
1055                         while (i--)
1056                                 kfree(fm->e[i]);
1057
1058                         ret = -ENOMEM;
1059                         goto free_hdr;
1060                 }
1061
1062                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1063                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1064                 fm->e[i] = e;
1065         }
1066
1067         ubi->fm = fm;
1068         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1069         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1070         ubi_msg("attached by fastmap");
1071         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1072         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1073         ubi->fm_disabled = 0;
1074         ubi->fast_attach = 1;
1075
1076         ubi_free_vid_hdr(ubi, vh);
1077         kfree(ech);
1078 out:
1079         mutex_unlock(&ubi->fm_mutex);
1080         if (ret == UBI_BAD_FASTMAP)
1081                 ubi_err("Attach by fastmap failed, doing a full scan!");
1082         return ret;
1083
1084 free_hdr:
1085         ubi_free_vid_hdr(ubi, vh);
1086         kfree(ech);
1087 free_fm_sb:
1088         kfree(fmsb);
1089         kfree(fm);
1090         goto out;
1091 }
1092
1093 /**
1094  * ubi_write_fastmap - writes a fastmap.
1095  * @ubi: UBI device object
1096  * @new_fm: the to be written fastmap
1097  *
1098  * Returns 0 on success, < 0 indicates an internal error.
1099  */
1100 static int ubi_write_fastmap(struct ubi_device *ubi,
1101                              struct ubi_fastmap_layout *new_fm)
1102 {
1103         size_t fm_pos = 0;
1104         void *fm_raw;
1105         struct ubi_fm_sb *fmsb;
1106         struct ubi_fm_hdr *fmh;
1107         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1108         struct ubi_fm_ec *fec;
1109         struct ubi_fm_volhdr *fvh;
1110         struct ubi_fm_eba *feba;
1111         struct rb_node *node;
1112         struct ubi_wl_entry *wl_e;
1113         struct ubi_volume *vol;
1114         struct ubi_vid_hdr *avhdr, *dvhdr;
1115         struct ubi_work *ubi_wrk;
1116         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1117         int scrub_peb_count, erase_peb_count;
1118
1119         fm_raw = ubi->fm_buf;
1120         memset(ubi->fm_buf, 0, ubi->fm_size);
1121
1122         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1123         if (!avhdr) {
1124                 ret = -ENOMEM;
1125                 goto out;
1126         }
1127
1128         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1129         if (!dvhdr) {
1130                 ret = -ENOMEM;
1131                 goto out_kfree;
1132         }
1133
1134         spin_lock(&ubi->volumes_lock);
1135         spin_lock(&ubi->wl_lock);
1136
1137         fmsb = (struct ubi_fm_sb *)fm_raw;
1138         fm_pos += sizeof(*fmsb);
1139         ubi_assert(fm_pos <= ubi->fm_size);
1140
1141         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1142         fm_pos += sizeof(*fmh);
1143         ubi_assert(fm_pos <= ubi->fm_size);
1144
1145         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1146         fmsb->version = UBI_FM_FMT_VERSION;
1147         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1148         /* the max sqnum will be filled in while *reading* the fastmap */
1149         fmsb->sqnum = 0;
1150
1151         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1152         free_peb_count = 0;
1153         used_peb_count = 0;
1154         scrub_peb_count = 0;
1155         erase_peb_count = 0;
1156         vol_count = 0;
1157
1158         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1159         fm_pos += sizeof(*fmpl1);
1160         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1161         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1162         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1163
1164         for (i = 0; i < ubi->fm_pool.size; i++)
1165                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1166
1167         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1168         fm_pos += sizeof(*fmpl2);
1169         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1170         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1171         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1172
1173         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1174                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1175
1176         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1177                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1178                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1179
1180                 fec->pnum = cpu_to_be32(wl_e->pnum);
1181                 fec->ec = cpu_to_be32(wl_e->ec);
1182
1183                 free_peb_count++;
1184                 fm_pos += sizeof(*fec);
1185                 ubi_assert(fm_pos <= ubi->fm_size);
1186         }
1187         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1188
1189         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1190                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1191                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1192
1193                 fec->pnum = cpu_to_be32(wl_e->pnum);
1194                 fec->ec = cpu_to_be32(wl_e->ec);
1195
1196                 used_peb_count++;
1197                 fm_pos += sizeof(*fec);
1198                 ubi_assert(fm_pos <= ubi->fm_size);
1199         }
1200         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1201
1202         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1203                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1204                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1205
1206                 fec->pnum = cpu_to_be32(wl_e->pnum);
1207                 fec->ec = cpu_to_be32(wl_e->ec);
1208
1209                 scrub_peb_count++;
1210                 fm_pos += sizeof(*fec);
1211                 ubi_assert(fm_pos <= ubi->fm_size);
1212         }
1213         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1214
1215
1216         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1217                 if (ubi_is_erase_work(ubi_wrk)) {
1218                         wl_e = ubi_wrk->e;
1219                         ubi_assert(wl_e);
1220
1221                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1222
1223                         fec->pnum = cpu_to_be32(wl_e->pnum);
1224                         fec->ec = cpu_to_be32(wl_e->ec);
1225
1226                         erase_peb_count++;
1227                         fm_pos += sizeof(*fec);
1228                         ubi_assert(fm_pos <= ubi->fm_size);
1229                 }
1230         }
1231         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1232
1233         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1234                 vol = ubi->volumes[i];
1235
1236                 if (!vol)
1237                         continue;
1238
1239                 vol_count++;
1240
1241                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1242                 fm_pos += sizeof(*fvh);
1243                 ubi_assert(fm_pos <= ubi->fm_size);
1244
1245                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1246                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1247                 fvh->vol_type = vol->vol_type;
1248                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1249                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1250                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1251
1252                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1253                         vol->vol_type == UBI_STATIC_VOLUME);
1254
1255                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1256                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1257                 ubi_assert(fm_pos <= ubi->fm_size);
1258
1259                 for (j = 0; j < vol->reserved_pebs; j++)
1260                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1261
1262                 feba->reserved_pebs = cpu_to_be32(j);
1263                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1264         }
1265         fmh->vol_count = cpu_to_be32(vol_count);
1266         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1267
1268         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1269         avhdr->lnum = 0;
1270
1271         spin_unlock(&ubi->wl_lock);
1272         spin_unlock(&ubi->volumes_lock);
1273
1274         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1275         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1276         if (ret) {
1277                 ubi_err("unable to write vid_hdr to fastmap SB!");
1278                 goto out_kfree;
1279         }
1280
1281         for (i = 0; i < new_fm->used_blocks; i++) {
1282                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1283                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1284         }
1285
1286         fmsb->data_crc = 0;
1287         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1288                                            ubi->fm_size));
1289
1290         for (i = 1; i < new_fm->used_blocks; i++) {
1291                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1292                 dvhdr->lnum = cpu_to_be32(i);
1293                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1294                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1295                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1296                 if (ret) {
1297                         ubi_err("unable to write vid_hdr to PEB %i!",
1298                                 new_fm->e[i]->pnum);
1299                         goto out_kfree;
1300                 }
1301         }
1302
1303         for (i = 0; i < new_fm->used_blocks; i++) {
1304                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1305                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1306                 if (ret) {
1307                         ubi_err("unable to write fastmap to PEB %i!",
1308                                 new_fm->e[i]->pnum);
1309                         goto out_kfree;
1310                 }
1311         }
1312
1313         ubi_assert(new_fm);
1314         ubi->fm = new_fm;
1315
1316         dbg_bld("fastmap written!");
1317
1318 out_kfree:
1319         ubi_free_vid_hdr(ubi, avhdr);
1320         ubi_free_vid_hdr(ubi, dvhdr);
1321 out:
1322         return ret;
1323 }
1324
1325 /**
1326  * erase_block - Manually erase a PEB.
1327  * @ubi: UBI device object
1328  * @pnum: PEB to be erased
1329  *
1330  * Returns the new EC value on success, < 0 indicates an internal error.
1331  */
1332 static int erase_block(struct ubi_device *ubi, int pnum)
1333 {
1334         int ret;
1335         struct ubi_ec_hdr *ec_hdr;
1336         long long ec;
1337
1338         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1339         if (!ec_hdr)
1340                 return -ENOMEM;
1341
1342         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1343         if (ret < 0)
1344                 goto out;
1345         else if (ret && ret != UBI_IO_BITFLIPS) {
1346                 ret = -EINVAL;
1347                 goto out;
1348         }
1349
1350         ret = ubi_io_sync_erase(ubi, pnum, 0);
1351         if (ret < 0)
1352                 goto out;
1353
1354         ec = be64_to_cpu(ec_hdr->ec);
1355         ec += ret;
1356         if (ec > UBI_MAX_ERASECOUNTER) {
1357                 ret = -EINVAL;
1358                 goto out;
1359         }
1360
1361         ec_hdr->ec = cpu_to_be64(ec);
1362         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1363         if (ret < 0)
1364                 goto out;
1365
1366         ret = ec;
1367 out:
1368         kfree(ec_hdr);
1369         return ret;
1370 }
1371
1372 /**
1373  * invalidate_fastmap - destroys a fastmap.
1374  * @ubi: UBI device object
1375  * @fm: the fastmap to be destroyed
1376  *
1377  * Returns 0 on success, < 0 indicates an internal error.
1378  */
1379 static int invalidate_fastmap(struct ubi_device *ubi,
1380                               struct ubi_fastmap_layout *fm)
1381 {
1382         int ret;
1383         struct ubi_vid_hdr *vh;
1384
1385         ret = erase_block(ubi, fm->e[0]->pnum);
1386         if (ret < 0)
1387                 return ret;
1388
1389         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1390         if (!vh)
1391                 return -ENOMEM;
1392
1393         /* deleting the current fastmap SB is not enough, an old SB may exist,
1394          * so create a (corrupted) SB such that fastmap will find it and fall
1395          * back to scanning mode in any case */
1396         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1397         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1398
1399         return ret;
1400 }
1401
1402 /**
1403  * ubi_update_fastmap - will be called by UBI if a volume changes or
1404  * a fastmap pool becomes full.
1405  * @ubi: UBI device object
1406  *
1407  * Returns 0 on success, < 0 indicates an internal error.
1408  */
1409 int ubi_update_fastmap(struct ubi_device *ubi)
1410 {
1411         int ret, i;
1412         struct ubi_fastmap_layout *new_fm, *old_fm;
1413         struct ubi_wl_entry *tmp_e;
1414
1415         mutex_lock(&ubi->fm_mutex);
1416
1417         ubi_refill_pools(ubi);
1418
1419         if (ubi->ro_mode || ubi->fm_disabled) {
1420                 mutex_unlock(&ubi->fm_mutex);
1421                 return 0;
1422         }
1423
1424         ret = ubi_ensure_anchor_pebs(ubi);
1425         if (ret) {
1426                 mutex_unlock(&ubi->fm_mutex);
1427                 return ret;
1428         }
1429
1430         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1431         if (!new_fm) {
1432                 mutex_unlock(&ubi->fm_mutex);
1433                 return -ENOMEM;
1434         }
1435
1436         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1437
1438         for (i = 0; i < new_fm->used_blocks; i++) {
1439                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1440                 if (!new_fm->e[i]) {
1441                         while (i--)
1442                                 kfree(new_fm->e[i]);
1443
1444                         kfree(new_fm);
1445                         mutex_unlock(&ubi->fm_mutex);
1446                         return -ENOMEM;
1447                 }
1448         }
1449
1450         old_fm = ubi->fm;
1451         ubi->fm = NULL;
1452
1453         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1454                 ubi_err("fastmap too large");
1455                 ret = -ENOSPC;
1456                 goto err;
1457         }
1458
1459         for (i = 1; i < new_fm->used_blocks; i++) {
1460                 spin_lock(&ubi->wl_lock);
1461                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1462                 spin_unlock(&ubi->wl_lock);
1463
1464                 if (!tmp_e && !old_fm) {
1465                         int j;
1466                         ubi_err("could not get any free erase block");
1467
1468                         for (j = 1; j < i; j++)
1469                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1470
1471                         ret = -ENOSPC;
1472                         goto err;
1473                 } else if (!tmp_e && old_fm) {
1474                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1475                         if (ret < 0) {
1476                                 int j;
1477
1478                                 for (j = 1; j < i; j++)
1479                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1480                                                           j, 0);
1481
1482                                 ubi_err("could not erase old fastmap PEB");
1483                                 goto err;
1484                         }
1485
1486                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1487                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1488                 } else {
1489                         new_fm->e[i]->pnum = tmp_e->pnum;
1490                         new_fm->e[i]->ec = tmp_e->ec;
1491
1492                         if (old_fm)
1493                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1494                                                   old_fm->to_be_tortured[i]);
1495                 }
1496         }
1497
1498         spin_lock(&ubi->wl_lock);
1499         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1500         spin_unlock(&ubi->wl_lock);
1501
1502         if (old_fm) {
1503                 /* no fresh anchor PEB was found, reuse the old one */
1504                 if (!tmp_e) {
1505                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1506                         if (ret < 0) {
1507                                 int i;
1508                                 ubi_err("could not erase old anchor PEB");
1509
1510                                 for (i = 1; i < new_fm->used_blocks; i++)
1511                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1512                                                           i, 0);
1513                                 goto err;
1514                         }
1515
1516                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1517                         new_fm->e[0]->ec = ret;
1518                 } else {
1519                         /* we've got a new anchor PEB, return the old one */
1520                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1521                                           old_fm->to_be_tortured[0]);
1522
1523                         new_fm->e[0]->pnum = tmp_e->pnum;
1524                         new_fm->e[0]->ec = tmp_e->ec;
1525                 }
1526         } else {
1527                 if (!tmp_e) {
1528                         int i;
1529                         ubi_err("could not find any anchor PEB");
1530
1531                         for (i = 1; i < new_fm->used_blocks; i++)
1532                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1533
1534                         ret = -ENOSPC;
1535                         goto err;
1536                 }
1537
1538                 new_fm->e[0]->pnum = tmp_e->pnum;
1539                 new_fm->e[0]->ec = tmp_e->ec;
1540         }
1541
1542         down_write(&ubi->work_sem);
1543         down_write(&ubi->fm_sem);
1544         ret = ubi_write_fastmap(ubi, new_fm);
1545         up_write(&ubi->fm_sem);
1546         up_write(&ubi->work_sem);
1547
1548         if (ret)
1549                 goto err;
1550
1551 out_unlock:
1552         mutex_unlock(&ubi->fm_mutex);
1553         kfree(old_fm);
1554         return ret;
1555
1556 err:
1557         kfree(new_fm);
1558
1559         ubi_warn("Unable to write new fastmap, err=%i", ret);
1560
1561         ret = 0;
1562         if (old_fm) {
1563                 ret = invalidate_fastmap(ubi, old_fm);
1564                 if (ret < 0)
1565                         ubi_err("Unable to invalidiate current fastmap!");
1566                 else if (ret)
1567                         ret = 0;
1568         }
1569         goto out_unlock;
1570 }