drivers/mtd/ubi/fastmap.c

   1 /*
   2  * Copyright (c) 2012 Linutronix GmbH
   3  * Author: Richard Weinberger <richard@nod.at>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  *
   7  */
   8
   9 #define __UBOOT__
  10 #ifndef __UBOOT__
  11 #include <linux/crc32.h>
  12 #else
  13 #include <div64.h>
  14 #include <malloc.h>
  15 #include <ubi_uboot.h>
  16 #endif
  17
  18 #include <linux/compat.h>
  19 #include <linux/math64.h>
  20 #include "ubi.h"
  21
  22 /**
  23  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  24  * @ubi: UBI device description object
  25  */
  26 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  27 {
  28         size_t size;
  29
  30         size = sizeof(struct ubi_fm_hdr) + \
  31                 sizeof(struct ubi_fm_scan_pool) + \
  32                 sizeof(struct ubi_fm_scan_pool) + \
  33                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) + \
  34                 (sizeof(struct ubi_fm_eba) + \
  35                 (ubi->peb_count * sizeof(__be32))) + \
  36                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  37         return roundup(size, ubi->leb_size);
  38 }
  39
  40
  41 /**
  42  * new_fm_vhdr - allocate a new volume header for fastmap usage.
  43  * @ubi: UBI device description object
  44  * @vol_id: the VID of the new header
  45  *
  46  * Returns a new struct ubi_vid_hdr on success.
  47  * NULL indicates out of memory.
  48  */
  49 static struct ubi_vid_hdr *new_fm_vhdr(struct ubi_device *ubi, int vol_id)
  50 {
  51         struct ubi_vid_hdr *new;
  52
  53         new = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
  54         if (!new)
  55                 goto out;
  56
  57         new->vol_type = UBI_VID_DYNAMIC;
  58         new->vol_id = cpu_to_be32(vol_id);
  59
  60         /* UBI implementations without fastmap support have to delete the
  61          * fastmap.
  62          */
  63         new->compat = UBI_COMPAT_DELETE;
  64
  65 out:
  66         return new;
  67 }
  68
  69 /**
  70  * add_aeb - create and add a attach erase block to a given list.
  71  * @ai: UBI attach info object
  72  * @list: the target list
  73  * @pnum: PEB number of the new attach erase block
  74  * @ec: erease counter of the new LEB
  75  * @scrub: scrub this PEB after attaching
  76  *
  77  * Returns 0 on success, < 0 indicates an internal error.
  78  */
  79 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
  80                    int pnum, int ec, int scrub)
  81 {
  82         struct ubi_ainf_peb *aeb;
  83
  84         aeb = kmem_cache_alloc(ai->aeb_slab_cache, GFP_KERNEL);
  85         if (!aeb)
  86                 return -ENOMEM;
  87
  88         aeb->pnum = pnum;
  89         aeb->ec = ec;
  90         aeb->lnum = -1;
  91         aeb->scrub = scrub;
  92         aeb->copy_flag = aeb->sqnum = 0;
  93
  94         ai->ec_sum += aeb->ec;
  95         ai->ec_count++;
  96
  97         if (ai->max_ec < aeb->ec)
  98                 ai->max_ec = aeb->ec;
  99
 100         if (ai->min_ec > aeb->ec)
 101                 ai->min_ec = aeb->ec;
 102
 103         list_add_tail(&aeb->u.list, list);
 104
 105         return 0;
 106 }
 107
 108 /**
 109  * add_vol - create and add a new volume to ubi_attach_info.
 110  * @ai: ubi_attach_info object
 111  * @vol_id: VID of the new volume
 112  * @used_ebs: number of used EBS
 113  * @data_pad: data padding value of the new volume
 114  * @vol_type: volume type
 115  * @last_eb_bytes: number of bytes in the last LEB
 116  *
 117  * Returns the new struct ubi_ainf_volume on success.
 118  * NULL indicates an error.
 119  */
 120 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 121                                        int used_ebs, int data_pad, u8 vol_type,
 122                                        int last_eb_bytes)
 123 {
 124         struct ubi_ainf_volume *av;
 125         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 126
 127         while (*p) {
 128                 parent = *p;
 129                 av = rb_entry(parent, struct ubi_ainf_volume, rb);
 130
 131                 if (vol_id > av->vol_id)
 132                         p = &(*p)->rb_left;
 133                 else if (vol_id > av->vol_id)
 134                         p = &(*p)->rb_right;
 135         }
 136
 137         av = kmalloc(sizeof(struct ubi_ainf_volume), GFP_KERNEL);
 138         if (!av)
 139                 goto out;
 140
 141         av->highest_lnum = av->leb_count = 0;
 142         av->vol_id = vol_id;
 143         av->used_ebs = used_ebs;
 144         av->data_pad = data_pad;
 145         av->last_data_size = last_eb_bytes;
 146         av->compat = 0;
 147         av->vol_type = vol_type;
 148         av->root = RB_ROOT;
 149
 150         dbg_bld("found volume (ID %i)", vol_id);
 151
 152         rb_link_node(&av->rb, parent, p);
 153         rb_insert_color(&av->rb, &ai->volumes);
 154
 155 out:
 156         return av;
 157 }
 158
 159 /**
 160  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 161  * from it's original list.
 162  * @ai: ubi_attach_info object
 163  * @aeb: the to be assigned SEB
 164  * @av: target scan volume
 165  */
 166 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 167                              struct ubi_ainf_peb *aeb,
 168                              struct ubi_ainf_volume *av)
 169 {
 170         struct ubi_ainf_peb *tmp_aeb;
 171         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 172
 173         p = &av->root.rb_node;
 174         while (*p) {
 175                 parent = *p;
 176
 177                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 178                 if (aeb->lnum != tmp_aeb->lnum) {
 179                         if (aeb->lnum < tmp_aeb->lnum)
 180                                 p = &(*p)->rb_left;
 181                         else
 182                                 p = &(*p)->rb_right;
 183
 184                         continue;
 185                 } else
 186                         break;
 187         }
 188
 189         list_del(&aeb->u.list);
 190         av->leb_count++;
 191
 192         rb_link_node(&aeb->u.rb, parent, p);
 193         rb_insert_color(&aeb->u.rb, &av->root);
 194 }
 195
 196 /**
 197  * update_vol - inserts or updates a LEB which was found a pool.
 198  * @ubi: the UBI device object
 199  * @ai: attach info object
 200  * @av: the volume this LEB belongs to
 201  * @new_vh: the volume header derived from new_aeb
 202  * @new_aeb: the AEB to be examined
 203  *
 204  * Returns 0 on success, < 0 indicates an internal error.
 205  */
 206 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 207                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 208                       struct ubi_ainf_peb *new_aeb)
 209 {
 210         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 211         struct ubi_ainf_peb *aeb, *victim;
 212         int cmp_res;
 213
 214         while (*p) {
 215                 parent = *p;
 216                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 217
 218                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 219                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 220                                 p = &(*p)->rb_left;
 221                         else
 222                                 p = &(*p)->rb_right;
 223
 224                         continue;
 225                 }
 226
 227                 /* This case can happen if the fastmap gets written
 228                  * because of a volume change (creation, deletion, ..).
 229                  * Then a PEB can be within the persistent EBA and the pool.
 230                  */
 231                 if (aeb->pnum == new_aeb->pnum) {
 232                         ubi_assert(aeb->lnum == new_aeb->lnum);
 233                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 234
 235                         return 0;
 236                 }
 237
 238                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 239                 if (cmp_res < 0)
 240                         return cmp_res;
 241
 242                 /* new_aeb is newer */
 243                 if (cmp_res & 1) {
 244                         victim = kmem_cache_alloc(ai->aeb_slab_cache,
 245                                 GFP_KERNEL);
 246                         if (!victim)
 247                                 return -ENOMEM;
 248
 249                         victim->ec = aeb->ec;
 250                         victim->pnum = aeb->pnum;
 251                         list_add_tail(&victim->u.list, &ai->erase);
 252
 253                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 254                                 av->last_data_size = \
 255                                         be32_to_cpu(new_vh->data_size);
 256
 257                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 258                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 259
 260                         aeb->ec = new_aeb->ec;
 261                         aeb->pnum = new_aeb->pnum;
 262                         aeb->copy_flag = new_vh->copy_flag;
 263                         aeb->scrub = new_aeb->scrub;
 264                         kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 265
 266                 /* new_aeb is older */
 267                 } else {
 268                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 269                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 270                         list_add_tail(&new_aeb->u.list, &ai->erase);
 271                 }
 272
 273                 return 0;
 274         }
 275         /* This LEB is new, let's add it to the volume */
 276
 277         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 278                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 279                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 280         }
 281
 282         if (av->vol_type == UBI_STATIC_VOLUME)
 283                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 284
 285         av->leb_count++;
 286
 287         rb_link_node(&new_aeb->u.rb, parent, p);
 288         rb_insert_color(&new_aeb->u.rb, &av->root);
 289
 290         return 0;
 291 }
 292
 293 /**
 294  * process_pool_aeb - we found a non-empty PEB in a pool.
 295  * @ubi: UBI device object
 296  * @ai: attach info object
 297  * @new_vh: the volume header derived from new_aeb
 298  * @new_aeb: the AEB to be examined
 299  *
 300  * Returns 0 on success, < 0 indicates an internal error.
 301  */
 302 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 303                             struct ubi_vid_hdr *new_vh,
 304                             struct ubi_ainf_peb *new_aeb)
 305 {
 306         struct ubi_ainf_volume *av, *tmp_av = NULL;
 307         struct rb_node **p = &ai->volumes.rb_node, *parent = NULL;
 308         int found = 0;
 309
 310         if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
 311                 be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
 312                 kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 313
 314                 return 0;
 315         }
 316
 317         /* Find the volume this SEB belongs to */
 318         while (*p) {
 319                 parent = *p;
 320                 tmp_av = rb_entry(parent, struct ubi_ainf_volume, rb);
 321
 322                 if (be32_to_cpu(new_vh->vol_id) > tmp_av->vol_id)
 323                         p = &(*p)->rb_left;
 324                 else if (be32_to_cpu(new_vh->vol_id) < tmp_av->vol_id)
 325                         p = &(*p)->rb_right;
 326                 else {
 327                         found = 1;
 328                         break;
 329                 }
 330         }
 331
 332         if (found)
 333                 av = tmp_av;
 334         else {
 335                 ubi_err("orphaned volume in fastmap pool!");
 336                 return UBI_BAD_FASTMAP;
 337         }
 338
 339         ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
 340
 341         return update_vol(ubi, ai, av, new_vh, new_aeb);
 342 }
 343
 344 /**
 345  * unmap_peb - unmap a PEB.
 346  * If fastmap detects a free PEB in the pool it has to check whether
 347  * this PEB has been unmapped after writing the fastmap.
 348  *
 349  * @ai: UBI attach info object
 350  * @pnum: The PEB to be unmapped
 351  */
 352 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 353 {
 354         struct ubi_ainf_volume *av;
 355         struct rb_node *node, *node2;
 356         struct ubi_ainf_peb *aeb;
 357
 358         for (node = rb_first(&ai->volumes); node; node = rb_next(node)) {
 359                 av = rb_entry(node, struct ubi_ainf_volume, rb);
 360
 361                 for (node2 = rb_first(&av->root); node2;
 362                      node2 = rb_next(node2)) {
 363                         aeb = rb_entry(node2, struct ubi_ainf_peb, u.rb);
 364                         if (aeb->pnum == pnum) {
 365                                 rb_erase(&aeb->u.rb, &av->root);
 366                                 kmem_cache_free(ai->aeb_slab_cache, aeb);
 367                                 return;
 368                         }
 369                 }
 370         }
 371 }
 372
 373 /**
 374  * scan_pool - scans a pool for changed (no longer empty PEBs).
 375  * @ubi: UBI device object
 376  * @ai: attach info object
 377  * @pebs: an array of all PEB numbers in the to be scanned pool
 378  * @pool_size: size of the pool (number of entries in @pebs)
 379  * @max_sqnum: pointer to the maximal sequence number
 380  * @eba_orphans: list of PEBs which need to be scanned
 381  * @free: list of PEBs which are most likely free (and go into @ai->free)
 382  *
 383  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 384  * < 0 indicates an internal error.
 385  */
 386 #ifndef __UBOOT__
 387 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 388                      int *pebs, int pool_size, unsigned long long *max_sqnum,
 389                      struct list_head *eba_orphans, struct list_head *freef)
 390 #else
 391 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 392                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 393                      struct list_head *eba_orphans, struct list_head *freef)
 394 #endif
 395 {
 396         struct ubi_vid_hdr *vh;
 397         struct ubi_ec_hdr *ech;
 398         struct ubi_ainf_peb *new_aeb, *tmp_aeb;
 399         int i, pnum, err, found_orphan, ret = 0;
 400
 401         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 402         if (!ech)
 403                 return -ENOMEM;
 404
 405         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 406         if (!vh) {
 407                 kfree(ech);
 408                 return -ENOMEM;
 409         }
 410
 411         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 412
 413         /*
 414          * Now scan all PEBs in the pool to find changes which have been made
 415          * after the creation of the fastmap
 416          */
 417         for (i = 0; i < pool_size; i++) {
 418                 int scrub = 0;
 419                 int image_seq;
 420
 421                 pnum = be32_to_cpu(pebs[i]);
 422
 423                 if (ubi_io_is_bad(ubi, pnum)) {
 424                         ubi_err("bad PEB in fastmap pool!");
 425                         ret = UBI_BAD_FASTMAP;
 426                         goto out;
 427                 }
 428
 429                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 430                 if (err && err != UBI_IO_BITFLIPS) {
 431                         ubi_err("unable to read EC header! PEB:%i err:%i",
 432                                 pnum, err);
 433                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 434                         goto out;
 435                 } else if (ret == UBI_IO_BITFLIPS)
 436                         scrub = 1;
 437
 438                 /*
 439                  * Older UBI implementations have image_seq set to zero, so
 440                  * we shouldn't fail if image_seq == 0.
 441                  */
 442                 image_seq = be32_to_cpu(ech->image_seq);
 443
 444                 if (image_seq && (image_seq != ubi->image_seq)) {
 445                         ubi_err("bad image seq: 0x%x, expected: 0x%x",
 446                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 447                         ret = UBI_BAD_FASTMAP;
 448                         goto out;
 449                 }
 450
 451                 err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 452                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 453                         unsigned long long ec = be64_to_cpu(ech->ec);
 454                         unmap_peb(ai, pnum);
 455                         dbg_bld("Adding PEB to free: %i", pnum);
 456                         if (err == UBI_IO_FF_BITFLIPS)
 457                                 add_aeb(ai, freef, pnum, ec, 1);
 458                         else
 459                                 add_aeb(ai, freef, pnum, ec, 0);
 460                         continue;
 461                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 462                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 463
 464                         if (err == UBI_IO_BITFLIPS)
 465                                 scrub = 1;
 466
 467                         found_orphan = 0;
 468                         list_for_each_entry(tmp_aeb, eba_orphans, u.list) {
 469                                 if (tmp_aeb->pnum == pnum) {
 470                                         found_orphan = 1;
 471                                         break;
 472                                 }
 473                         }
 474                         if (found_orphan) {
 475                                 list_del(&tmp_aeb->u.list);
 476                                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 477                         }
 478
 479                         new_aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 480                                                    GFP_KERNEL);
 481                         if (!new_aeb) {
 482                                 ret = -ENOMEM;
 483                                 goto out;
 484                         }
 485
 486                         new_aeb->ec = be64_to_cpu(ech->ec);
 487                         new_aeb->pnum = pnum;
 488                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 489                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 490                         new_aeb->copy_flag = vh->copy_flag;
 491                         new_aeb->scrub = scrub;
 492
 493                         if (*max_sqnum < new_aeb->sqnum)
 494                                 *max_sqnum = new_aeb->sqnum;
 495
 496                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 497                         if (err) {
 498                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 499                                 goto out;
 500                         }
 501                 } else {
 502                         /* We are paranoid and fall back to scanning mode */
 503                         ubi_err("fastmap pool PEBs contains damaged PEBs!");
 504                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 505                         goto out;
 506                 }
 507
 508         }
 509
 510 out:
 511         ubi_free_vid_hdr(ubi, vh);
 512         kfree(ech);
 513         return ret;
 514 }
 515
 516 /**
 517  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 518  * @ai: The UBI attach info object
 519  */
 520 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 521 {
 522         struct ubi_ainf_peb *aeb;
 523         struct ubi_ainf_volume *av;
 524         struct rb_node *rb1, *rb2;
 525         int n = 0;
 526
 527         list_for_each_entry(aeb, &ai->erase, u.list)
 528                 n++;
 529
 530         list_for_each_entry(aeb, &ai->free, u.list)
 531                 n++;
 532
 533          ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 534                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 535                         n++;
 536
 537         return n;
 538 }
 539
 540 /**
 541  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 542  * @ubi: UBI device object
 543  * @ai: UBI attach info object
 544  * @fm: the fastmap to be attached
 545  *
 546  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 547  * < 0 indicates an internal error.
 548  */
 549 static int ubi_attach_fastmap(struct ubi_device *ubi,
 550                               struct ubi_attach_info *ai,
 551                               struct ubi_fastmap_layout *fm)
 552 {
 553         struct list_head used, eba_orphans, freef;
 554         struct ubi_ainf_volume *av;
 555         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 556         struct ubi_ec_hdr *ech;
 557         struct ubi_fm_sb *fmsb;
 558         struct ubi_fm_hdr *fmhdr;
 559         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
 560         struct ubi_fm_ec *fmec;
 561         struct ubi_fm_volhdr *fmvhdr;
 562         struct ubi_fm_eba *fm_eba;
 563         int ret, i, j, pool_size, wl_pool_size;
 564         size_t fm_pos = 0, fm_size = ubi->fm_size;
 565         unsigned long long max_sqnum = 0;
 566         void *fm_raw = ubi->fm_buf;
 567
 568         INIT_LIST_HEAD(&used);
 569         INIT_LIST_HEAD(&freef);
 570         INIT_LIST_HEAD(&eba_orphans);
 571         INIT_LIST_HEAD(&ai->corr);
 572         INIT_LIST_HEAD(&ai->free);
 573         INIT_LIST_HEAD(&ai->erase);
 574         INIT_LIST_HEAD(&ai->alien);
 575         ai->volumes = RB_ROOT;
 576         ai->min_ec = UBI_MAX_ERASECOUNTER;
 577
 578         ai->aeb_slab_cache = kmem_cache_create("ubi_ainf_peb_slab",
 579                                                sizeof(struct ubi_ainf_peb),
 580                                                0, 0, NULL);
 581         if (!ai->aeb_slab_cache) {
 582                 ret = -ENOMEM;
 583                 goto fail;
 584         }
 585
 586         fmsb = (struct ubi_fm_sb *)(fm_raw);
 587         ai->max_sqnum = fmsb->sqnum;
 588         fm_pos += sizeof(struct ubi_fm_sb);
 589         if (fm_pos >= fm_size)
 590                 goto fail_bad;
 591
 592         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 593         fm_pos += sizeof(*fmhdr);
 594         if (fm_pos >= fm_size)
 595                 goto fail_bad;
 596
 597         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 598                 ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
 599                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 600                 goto fail_bad;
 601         }
 602
 603         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 604         fm_pos += sizeof(*fmpl1);
 605         if (fm_pos >= fm_size)
 606                 goto fail_bad;
 607         if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
 608                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 609                         be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
 610                 goto fail_bad;
 611         }
 612
 613         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 614         fm_pos += sizeof(*fmpl2);
 615         if (fm_pos >= fm_size)
 616                 goto fail_bad;
 617         if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
 618                 ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
 619                         be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
 620                 goto fail_bad;
 621         }
 622
 623         pool_size = be16_to_cpu(fmpl1->size);
 624         wl_pool_size = be16_to_cpu(fmpl2->size);
 625         fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
 626         fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);
 627
 628         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 629                 ubi_err("bad pool size: %i", pool_size);
 630                 goto fail_bad;
 631         }
 632
 633         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 634                 ubi_err("bad WL pool size: %i", wl_pool_size);
 635                 goto fail_bad;
 636         }
 637
 638
 639         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 640             fm->max_pool_size < 0) {
 641                 ubi_err("bad maximal pool size: %i", fm->max_pool_size);
 642                 goto fail_bad;
 643         }
 644
 645         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 646             fm->max_wl_pool_size < 0) {
 647                 ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
 648                 goto fail_bad;
 649         }
 650
 651         /* read EC values from free list */
 652         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 653                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 654                 fm_pos += sizeof(*fmec);
 655                 if (fm_pos >= fm_size)
 656                         goto fail_bad;
 657
 658                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 659                         be32_to_cpu(fmec->ec), 0);
 660         }
 661
 662         /* read EC values from used list */
 663         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 664                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 665                 fm_pos += sizeof(*fmec);
 666                 if (fm_pos >= fm_size)
 667                         goto fail_bad;
 668
 669                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 670                         be32_to_cpu(fmec->ec), 0);
 671         }
 672
 673         /* read EC values from scrub list */
 674         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 675                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 676                 fm_pos += sizeof(*fmec);
 677                 if (fm_pos >= fm_size)
 678                         goto fail_bad;
 679
 680                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 681                         be32_to_cpu(fmec->ec), 1);
 682         }
 683
 684         /* read EC values from erase list */
 685         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 686                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 687                 fm_pos += sizeof(*fmec);
 688                 if (fm_pos >= fm_size)
 689                         goto fail_bad;
 690
 691                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 692                         be32_to_cpu(fmec->ec), 1);
 693         }
 694
 695         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 696         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 697
 698         /* Iterate over all volumes and read their EBA table */
 699         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 700                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 701                 fm_pos += sizeof(*fmvhdr);
 702                 if (fm_pos >= fm_size)
 703                         goto fail_bad;
 704
 705                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 706                         ubi_err("bad fastmap vol header magic: 0x%x, " \
 707                                 "expected: 0x%x",
 708                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 709                         goto fail_bad;
 710                 }
 711
 712                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 713                              be32_to_cpu(fmvhdr->used_ebs),
 714                              be32_to_cpu(fmvhdr->data_pad),
 715                              fmvhdr->vol_type,
 716                              be32_to_cpu(fmvhdr->last_eb_bytes));
 717
 718                 if (!av)
 719                         goto fail_bad;
 720
 721                 ai->vols_found++;
 722                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 723                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 724
 725                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 726                 fm_pos += sizeof(*fm_eba);
 727                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 728                 if (fm_pos >= fm_size)
 729                         goto fail_bad;
 730
 731                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 732                         ubi_err("bad fastmap EBA header magic: 0x%x, " \
 733                                 "expected: 0x%x",
 734                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 735                         goto fail_bad;
 736                 }
 737
 738                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 739                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 740
 741                         if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
 742                                 continue;
 743
 744                         aeb = NULL;
 745                         list_for_each_entry(tmp_aeb, &used, u.list) {
 746                                 if (tmp_aeb->pnum == pnum) {
 747                                         aeb = tmp_aeb;
 748                                         break;
 749                                 }
 750                         }
 751
 752                         /* This can happen if a PEB is already in an EBA known
 753                          * by this fastmap but the PEB itself is not in the used
 754                          * list.
 755                          * In this case the PEB can be within the fastmap pool
 756                          * or while writing the fastmap it was in the protection
 757                          * queue.
 758                          */
 759                         if (!aeb) {
 760                                 aeb = kmem_cache_alloc(ai->aeb_slab_cache,
 761                                                        GFP_KERNEL);
 762                                 if (!aeb) {
 763                                         ret = -ENOMEM;
 764
 765                                         goto fail;
 766                                 }
 767
 768                                 aeb->lnum = j;
 769                                 aeb->pnum = be32_to_cpu(fm_eba->pnum[j]);
 770                                 aeb->ec = -1;
 771                                 aeb->scrub = aeb->copy_flag = aeb->sqnum = 0;
 772                                 list_add_tail(&aeb->u.list, &eba_orphans);
 773                                 continue;
 774                         }
 775
 776                         aeb->lnum = j;
 777
 778                         if (av->highest_lnum <= aeb->lnum)
 779                                 av->highest_lnum = aeb->lnum;
 780
 781                         assign_aeb_to_av(ai, aeb, av);
 782
 783                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 784                                 aeb->pnum, aeb->lnum, av->vol_id);
 785                 }
 786
 787                 ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 788                 if (!ech) {
 789                         ret = -ENOMEM;
 790                         goto fail;
 791                 }
 792
 793                 list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans,
 794                                          u.list) {
 795                         int err;
 796
 797                         if (ubi_io_is_bad(ubi, tmp_aeb->pnum)) {
 798                                 ubi_err("bad PEB in fastmap EBA orphan list");
 799                                 ret = UBI_BAD_FASTMAP;
 800                                 kfree(ech);
 801                                 goto fail;
 802                         }
 803
 804                         err = ubi_io_read_ec_hdr(ubi, tmp_aeb->pnum, ech, 0);
 805                         if (err && err != UBI_IO_BITFLIPS) {
 806                                 ubi_err("unable to read EC header! PEB:%i " \
 807                                         "err:%i", tmp_aeb->pnum, err);
 808                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 809                                 kfree(ech);
 810
 811                                 goto fail;
 812                         } else if (err == UBI_IO_BITFLIPS)
 813                                 tmp_aeb->scrub = 1;
 814
 815                         tmp_aeb->ec = be64_to_cpu(ech->ec);
 816                         assign_aeb_to_av(ai, tmp_aeb, av);
 817                 }
 818
 819                 kfree(ech);
 820         }
 821
 822         ret = scan_pool(ubi, ai, fmpl1->pebs, pool_size, &max_sqnum,
 823                         &eba_orphans, &freef);
 824         if (ret)
 825                 goto fail;
 826
 827         ret = scan_pool(ubi, ai, fmpl2->pebs, wl_pool_size, &max_sqnum,
 828                         &eba_orphans, &freef);
 829         if (ret)
 830                 goto fail;
 831
 832         if (max_sqnum > ai->max_sqnum)
 833                 ai->max_sqnum = max_sqnum;
 834
 835         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &freef, u.list)
 836                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 837
 838         ubi_assert(list_empty(&used));
 839         ubi_assert(list_empty(&eba_orphans));
 840         ubi_assert(list_empty(&freef));
 841
 842         /*
 843          * If fastmap is leaking PEBs (must not happen), raise a
 844          * fat warning and fall back to scanning mode.
 845          * We do this here because in ubi_wl_init() it's too late
 846          * and we cannot fall back to scanning.
 847          */
 848 #ifndef __UBOOT__
 849         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 850                     ai->bad_peb_count - fm->used_blocks))
 851                 goto fail_bad;
 852 #else
 853         if (count_fastmap_pebs(ai) != ubi->peb_count -
 854                     ai->bad_peb_count - fm->used_blocks) {
 855                 WARN_ON(1);
 856                 goto fail_bad;
 857         }
 858 #endif
 859
 860         return 0;
 861
 862 fail_bad:
 863         ret = UBI_BAD_FASTMAP;
 864 fail:
 865         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 866                 list_del(&tmp_aeb->u.list);
 867                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 868         }
 869         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &eba_orphans, u.list) {
 870                 list_del(&tmp_aeb->u.list);
 871                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 872         }
 873         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &freef, u.list) {
 874                 list_del(&tmp_aeb->u.list);
 875                 kmem_cache_free(ai->aeb_slab_cache, tmp_aeb);
 876         }
 877
 878         return ret;
 879 }
 880
 881 /**
 882  * ubi_scan_fastmap - scan the fastmap.
 883  * @ubi: UBI device object
 884  * @ai: UBI attach info to be filled
 885  * @fm_anchor: The fastmap starts at this PEB
 886  *
 887  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 888  * UBI_BAD_FASTMAP if one was found but is not usable.
 889  * < 0 indicates an internal error.
 890  */
 891 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 892                      int fm_anchor)
 893 {
 894         struct ubi_fm_sb *fmsb, *fmsb2;
 895         struct ubi_vid_hdr *vh;
 896         struct ubi_ec_hdr *ech;
 897         struct ubi_fastmap_layout *fm;
 898         int i, used_blocks, pnum, ret = 0;
 899         size_t fm_size;
 900         __be32 crc, tmp_crc;
 901         unsigned long long sqnum = 0;
 902
 903         mutex_lock(&ubi->fm_mutex);
 904         memset(ubi->fm_buf, 0, ubi->fm_size);
 905
 906         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 907         if (!fmsb) {
 908                 ret = -ENOMEM;
 909                 goto out;
 910         }
 911
 912         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 913         if (!fm) {
 914                 ret = -ENOMEM;
 915                 kfree(fmsb);
 916                 goto out;
 917         }
 918
 919         ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
 920         if (ret && ret != UBI_IO_BITFLIPS)
 921                 goto free_fm_sb;
 922         else if (ret == UBI_IO_BITFLIPS)
 923                 fm->to_be_tortured[0] = 1;
 924
 925         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 926                 ubi_err("bad super block magic: 0x%x, expected: 0x%x",
 927                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 928                 ret = UBI_BAD_FASTMAP;
 929                 goto free_fm_sb;
 930         }
 931
 932         if (fmsb->version != UBI_FM_FMT_VERSION) {
 933                 ubi_err("bad fastmap version: %i, expected: %i",
 934                         fmsb->version, UBI_FM_FMT_VERSION);
 935                 ret = UBI_BAD_FASTMAP;
 936                 goto free_fm_sb;
 937         }
 938
 939         used_blocks = be32_to_cpu(fmsb->used_blocks);
 940         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 941                 ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
 942                 ret = UBI_BAD_FASTMAP;
 943                 goto free_fm_sb;
 944         }
 945
 946         fm_size = ubi->leb_size * used_blocks;
 947         if (fm_size != ubi->fm_size) {
 948                 ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
 949                         ubi->fm_size);
 950                 ret = UBI_BAD_FASTMAP;
 951                 goto free_fm_sb;
 952         }
 953
 954         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 955         if (!ech) {
 956                 ret = -ENOMEM;
 957                 goto free_fm_sb;
 958         }
 959
 960         vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 961         if (!vh) {
 962                 ret = -ENOMEM;
 963                 goto free_hdr;
 964         }
 965
 966         for (i = 0; i < used_blocks; i++) {
 967                 int image_seq;
 968
 969                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 970
 971                 if (ubi_io_is_bad(ubi, pnum)) {
 972                         ret = UBI_BAD_FASTMAP;
 973                         goto free_hdr;
 974                 }
 975
 976                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 977                 if (ret && ret != UBI_IO_BITFLIPS) {
 978                         ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
 979                                 i, pnum);
 980                         if (ret > 0)
 981                                 ret = UBI_BAD_FASTMAP;
 982                         goto free_hdr;
 983                 } else if (ret == UBI_IO_BITFLIPS)
 984                         fm->to_be_tortured[i] = 1;
 985
 986                 image_seq = be32_to_cpu(ech->image_seq);
 987                 if (!ubi->image_seq)
 988                         ubi->image_seq = image_seq;
 989
 990                 /*
 991                  * Older UBI implementations have image_seq set to zero, so
 992                  * we shouldn't fail if image_seq == 0.
 993                  */
 994                 if (image_seq && (image_seq != ubi->image_seq)) {
 995                         ubi_err("wrong image seq:%d instead of %d",
 996                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 997                         ret = UBI_BAD_FASTMAP;
 998                         goto free_hdr;
 999                 }
1000
1001                 ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
1002                 if (ret && ret != UBI_IO_BITFLIPS) {
1003                         ubi_err("unable to read fastmap block# %i (PEB: %i)",
1004                                 i, pnum);
1005                         goto free_hdr;
1006                 }
1007
1008                 if (i == 0) {
1009                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
1010                                 ubi_err("bad fastmap anchor vol_id: 0x%x," \
1011                                         " expected: 0x%x",
1012                                         be32_to_cpu(vh->vol_id),
1013                                         UBI_FM_SB_VOLUME_ID);
1014                                 ret = UBI_BAD_FASTMAP;
1015                                 goto free_hdr;
1016                         }
1017                 } else {
1018                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1019                                 ubi_err("bad fastmap data vol_id: 0x%x," \
1020                                         " expected: 0x%x",
1021                                         be32_to_cpu(vh->vol_id),
1022                                         UBI_FM_DATA_VOLUME_ID);
1023                                 ret = UBI_BAD_FASTMAP;
1024                                 goto free_hdr;
1025                         }
1026                 }
1027
1028                 if (sqnum < be64_to_cpu(vh->sqnum))
1029                         sqnum = be64_to_cpu(vh->sqnum);
1030
1031                 ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
1032                                   ubi->leb_start, ubi->leb_size);
1033                 if (ret && ret != UBI_IO_BITFLIPS) {
1034                         ubi_err("unable to read fastmap block# %i (PEB: %i, " \
1035                                 "err: %i)", i, pnum, ret);
1036                         goto free_hdr;
1037                 }
1038         }
1039
1040         kfree(fmsb);
1041         fmsb = NULL;
1042
1043         fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
1044         tmp_crc = be32_to_cpu(fmsb2->data_crc);
1045         fmsb2->data_crc = 0;
1046         crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
1047         if (crc != tmp_crc) {
1048                 ubi_err("fastmap data CRC is invalid");
1049                 ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
1050                 ret = UBI_BAD_FASTMAP;
1051                 goto free_hdr;
1052         }
1053
1054         fmsb2->sqnum = sqnum;
1055
1056         fm->used_blocks = used_blocks;
1057
1058         ret = ubi_attach_fastmap(ubi, ai, fm);
1059         if (ret) {
1060                 if (ret > 0)
1061                         ret = UBI_BAD_FASTMAP;
1062                 goto free_hdr;
1063         }
1064
1065         for (i = 0; i < used_blocks; i++) {
1066                 struct ubi_wl_entry *e;
1067
1068                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1069                 if (!e) {
1070                         while (i--)
1071                                 kfree(fm->e[i]);
1072
1073                         ret = -ENOMEM;
1074                         goto free_hdr;
1075                 }
1076
1077                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1078                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1079                 fm->e[i] = e;
1080         }
1081
1082         ubi->fm = fm;
1083         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1084         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1085         ubi_msg("attached by fastmap");
1086         ubi_msg("fastmap pool size: %d", ubi->fm_pool.max_size);
1087         ubi_msg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
1088         ubi->fm_disabled = 0;
1089
1090         ubi_free_vid_hdr(ubi, vh);
1091         kfree(ech);
1092 out:
1093         mutex_unlock(&ubi->fm_mutex);
1094         if (ret == UBI_BAD_FASTMAP)
1095                 ubi_err("Attach by fastmap failed, doing a full scan!");
1096         return ret;
1097
1098 free_hdr:
1099         ubi_free_vid_hdr(ubi, vh);
1100         kfree(ech);
1101 free_fm_sb:
1102         kfree(fmsb);
1103         kfree(fm);
1104         goto out;
1105 }
1106
1107 /**
1108  * ubi_write_fastmap - writes a fastmap.
1109  * @ubi: UBI device object
1110  * @new_fm: the to be written fastmap
1111  *
1112  * Returns 0 on success, < 0 indicates an internal error.
1113  */
1114 static int ubi_write_fastmap(struct ubi_device *ubi,
1115                              struct ubi_fastmap_layout *new_fm)
1116 {
1117         size_t fm_pos = 0;
1118         void *fm_raw;
1119         struct ubi_fm_sb *fmsb;
1120         struct ubi_fm_hdr *fmh;
1121         struct ubi_fm_scan_pool *fmpl1, *fmpl2;
1122         struct ubi_fm_ec *fec;
1123         struct ubi_fm_volhdr *fvh;
1124         struct ubi_fm_eba *feba;
1125         struct rb_node *node;
1126         struct ubi_wl_entry *wl_e;
1127         struct ubi_volume *vol;
1128         struct ubi_vid_hdr *avhdr, *dvhdr;
1129         struct ubi_work *ubi_wrk;
1130         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1131         int scrub_peb_count, erase_peb_count;
1132
1133         fm_raw = ubi->fm_buf;
1134         memset(ubi->fm_buf, 0, ubi->fm_size);
1135
1136         avhdr = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1137         if (!avhdr) {
1138                 ret = -ENOMEM;
1139                 goto out;
1140         }
1141
1142         dvhdr = new_fm_vhdr(ubi, UBI_FM_DATA_VOLUME_ID);
1143         if (!dvhdr) {
1144                 ret = -ENOMEM;
1145                 goto out_kfree;
1146         }
1147
1148         spin_lock(&ubi->volumes_lock);
1149         spin_lock(&ubi->wl_lock);
1150
1151         fmsb = (struct ubi_fm_sb *)fm_raw;
1152         fm_pos += sizeof(*fmsb);
1153         ubi_assert(fm_pos <= ubi->fm_size);
1154
1155         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1156         fm_pos += sizeof(*fmh);
1157         ubi_assert(fm_pos <= ubi->fm_size);
1158
1159         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1160         fmsb->version = UBI_FM_FMT_VERSION;
1161         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1162         /* the max sqnum will be filled in while *reading* the fastmap */
1163         fmsb->sqnum = 0;
1164
1165         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1166         free_peb_count = 0;
1167         used_peb_count = 0;
1168         scrub_peb_count = 0;
1169         erase_peb_count = 0;
1170         vol_count = 0;
1171
1172         fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1173         fm_pos += sizeof(*fmpl1);
1174         fmpl1->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1175         fmpl1->size = cpu_to_be16(ubi->fm_pool.size);
1176         fmpl1->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1177
1178         for (i = 0; i < ubi->fm_pool.size; i++)
1179                 fmpl1->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1180
1181         fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1182         fm_pos += sizeof(*fmpl2);
1183         fmpl2->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1184         fmpl2->size = cpu_to_be16(ubi->fm_wl_pool.size);
1185         fmpl2->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1186
1187         for (i = 0; i < ubi->fm_wl_pool.size; i++)
1188                 fmpl2->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1189
1190         for (node = rb_first(&ubi->free); node; node = rb_next(node)) {
1191                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1192                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1193
1194                 fec->pnum = cpu_to_be32(wl_e->pnum);
1195                 fec->ec = cpu_to_be32(wl_e->ec);
1196
1197                 free_peb_count++;
1198                 fm_pos += sizeof(*fec);
1199                 ubi_assert(fm_pos <= ubi->fm_size);
1200         }
1201         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1202
1203         for (node = rb_first(&ubi->used); node; node = rb_next(node)) {
1204                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1205                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1206
1207                 fec->pnum = cpu_to_be32(wl_e->pnum);
1208                 fec->ec = cpu_to_be32(wl_e->ec);
1209
1210                 used_peb_count++;
1211                 fm_pos += sizeof(*fec);
1212                 ubi_assert(fm_pos <= ubi->fm_size);
1213         }
1214         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1215
1216         for (node = rb_first(&ubi->scrub); node; node = rb_next(node)) {
1217                 wl_e = rb_entry(node, struct ubi_wl_entry, u.rb);
1218                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1219
1220                 fec->pnum = cpu_to_be32(wl_e->pnum);
1221                 fec->ec = cpu_to_be32(wl_e->ec);
1222
1223                 scrub_peb_count++;
1224                 fm_pos += sizeof(*fec);
1225                 ubi_assert(fm_pos <= ubi->fm_size);
1226         }
1227         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1228
1229
1230         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1231                 if (ubi_is_erase_work(ubi_wrk)) {
1232                         wl_e = ubi_wrk->e;
1233                         ubi_assert(wl_e);
1234
1235                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1236
1237                         fec->pnum = cpu_to_be32(wl_e->pnum);
1238                         fec->ec = cpu_to_be32(wl_e->ec);
1239
1240                         erase_peb_count++;
1241                         fm_pos += sizeof(*fec);
1242                         ubi_assert(fm_pos <= ubi->fm_size);
1243                 }
1244         }
1245         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1246
1247         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1248                 vol = ubi->volumes[i];
1249
1250                 if (!vol)
1251                         continue;
1252
1253                 vol_count++;
1254
1255                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1256                 fm_pos += sizeof(*fvh);
1257                 ubi_assert(fm_pos <= ubi->fm_size);
1258
1259                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1260                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1261                 fvh->vol_type = vol->vol_type;
1262                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1263                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1264                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1265
1266                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1267                         vol->vol_type == UBI_STATIC_VOLUME);
1268
1269                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1270                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1271                 ubi_assert(fm_pos <= ubi->fm_size);
1272
1273                 for (j = 0; j < vol->reserved_pebs; j++)
1274                         feba->pnum[j] = cpu_to_be32(vol->eba_tbl[j]);
1275
1276                 feba->reserved_pebs = cpu_to_be32(j);
1277                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1278         }
1279         fmh->vol_count = cpu_to_be32(vol_count);
1280         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1281
1282         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1283         avhdr->lnum = 0;
1284
1285         spin_unlock(&ubi->wl_lock);
1286         spin_unlock(&ubi->volumes_lock);
1287
1288         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1289         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avhdr);
1290         if (ret) {
1291                 ubi_err("unable to write vid_hdr to fastmap SB!");
1292                 goto out_kfree;
1293         }
1294
1295         for (i = 0; i < new_fm->used_blocks; i++) {
1296                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1297                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1298         }
1299
1300         fmsb->data_crc = 0;
1301         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1302                                            ubi->fm_size));
1303
1304         for (i = 1; i < new_fm->used_blocks; i++) {
1305                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1306                 dvhdr->lnum = cpu_to_be32(i);
1307                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1308                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1309                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvhdr);
1310                 if (ret) {
1311                         ubi_err("unable to write vid_hdr to PEB %i!",
1312                                 new_fm->e[i]->pnum);
1313                         goto out_kfree;
1314                 }
1315         }
1316
1317         for (i = 0; i < new_fm->used_blocks; i++) {
1318                 ret = ubi_io_write(ubi, fm_raw + (i * ubi->leb_size),
1319                         new_fm->e[i]->pnum, ubi->leb_start, ubi->leb_size);
1320                 if (ret) {
1321                         ubi_err("unable to write fastmap to PEB %i!",
1322                                 new_fm->e[i]->pnum);
1323                         goto out_kfree;
1324                 }
1325         }
1326
1327         ubi_assert(new_fm);
1328         ubi->fm = new_fm;
1329
1330         dbg_bld("fastmap written!");
1331
1332 out_kfree:
1333         ubi_free_vid_hdr(ubi, avhdr);
1334         ubi_free_vid_hdr(ubi, dvhdr);
1335 out:
1336         return ret;
1337 }
1338
1339 /**
1340  * erase_block - Manually erase a PEB.
1341  * @ubi: UBI device object
1342  * @pnum: PEB to be erased
1343  *
1344  * Returns the new EC value on success, < 0 indicates an internal error.
1345  */
1346 static int erase_block(struct ubi_device *ubi, int pnum)
1347 {
1348         int ret;
1349         struct ubi_ec_hdr *ec_hdr;
1350         long long ec;
1351
1352         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1353         if (!ec_hdr)
1354                 return -ENOMEM;
1355
1356         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1357         if (ret < 0)
1358                 goto out;
1359         else if (ret && ret != UBI_IO_BITFLIPS) {
1360                 ret = -EINVAL;
1361                 goto out;
1362         }
1363
1364         ret = ubi_io_sync_erase(ubi, pnum, 0);
1365         if (ret < 0)
1366                 goto out;
1367
1368         ec = be64_to_cpu(ec_hdr->ec);
1369         ec += ret;
1370         if (ec > UBI_MAX_ERASECOUNTER) {
1371                 ret = -EINVAL;
1372                 goto out;
1373         }
1374
1375         ec_hdr->ec = cpu_to_be64(ec);
1376         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1377         if (ret < 0)
1378                 goto out;
1379
1380         ret = ec;
1381 out:
1382         kfree(ec_hdr);
1383         return ret;
1384 }
1385
1386 /**
1387  * invalidate_fastmap - destroys a fastmap.
1388  * @ubi: UBI device object
1389  * @fm: the fastmap to be destroyed
1390  *
1391  * Returns 0 on success, < 0 indicates an internal error.
1392  */
1393 static int invalidate_fastmap(struct ubi_device *ubi,
1394                               struct ubi_fastmap_layout *fm)
1395 {
1396         int ret;
1397         struct ubi_vid_hdr *vh;
1398
1399         ret = erase_block(ubi, fm->e[0]->pnum);
1400         if (ret < 0)
1401                 return ret;
1402
1403         vh = new_fm_vhdr(ubi, UBI_FM_SB_VOLUME_ID);
1404         if (!vh)
1405                 return -ENOMEM;
1406
1407         /* deleting the current fastmap SB is not enough, an old SB may exist,
1408          * so create a (corrupted) SB such that fastmap will find it and fall
1409          * back to scanning mode in any case */
1410         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1411         ret = ubi_io_write_vid_hdr(ubi, fm->e[0]->pnum, vh);
1412
1413         return ret;
1414 }
1415
1416 /**
1417  * ubi_update_fastmap - will be called by UBI if a volume changes or
1418  * a fastmap pool becomes full.
1419  * @ubi: UBI device object
1420  *
1421  * Returns 0 on success, < 0 indicates an internal error.
1422  */
1423 int ubi_update_fastmap(struct ubi_device *ubi)
1424 {
1425         int ret, i;
1426         struct ubi_fastmap_layout *new_fm, *old_fm;
1427         struct ubi_wl_entry *tmp_e;
1428
1429         mutex_lock(&ubi->fm_mutex);
1430
1431         ubi_refill_pools(ubi);
1432
1433         if (ubi->ro_mode || ubi->fm_disabled) {
1434                 mutex_unlock(&ubi->fm_mutex);
1435                 return 0;
1436         }
1437
1438         ret = ubi_ensure_anchor_pebs(ubi);
1439         if (ret) {
1440                 mutex_unlock(&ubi->fm_mutex);
1441                 return ret;
1442         }
1443
1444         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1445         if (!new_fm) {
1446                 mutex_unlock(&ubi->fm_mutex);
1447                 return -ENOMEM;
1448         }
1449
1450         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1451
1452         for (i = 0; i < new_fm->used_blocks; i++) {
1453                 new_fm->e[i] = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1454                 if (!new_fm->e[i]) {
1455                         while (i--)
1456                                 kfree(new_fm->e[i]);
1457
1458                         kfree(new_fm);
1459                         mutex_unlock(&ubi->fm_mutex);
1460                         return -ENOMEM;
1461                 }
1462         }
1463
1464         old_fm = ubi->fm;
1465         ubi->fm = NULL;
1466
1467         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1468                 ubi_err("fastmap too large");
1469                 ret = -ENOSPC;
1470                 goto err;
1471         }
1472
1473         for (i = 1; i < new_fm->used_blocks; i++) {
1474                 spin_lock(&ubi->wl_lock);
1475                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1476                 spin_unlock(&ubi->wl_lock);
1477
1478                 if (!tmp_e && !old_fm) {
1479                         int j;
1480                         ubi_err("could not get any free erase block");
1481
1482                         for (j = 1; j < i; j++)
1483                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1484
1485                         ret = -ENOSPC;
1486                         goto err;
1487                 } else if (!tmp_e && old_fm) {
1488                         ret = erase_block(ubi, old_fm->e[i]->pnum);
1489                         if (ret < 0) {
1490                                 int j;
1491
1492                                 for (j = 1; j < i; j++)
1493                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1494                                                           j, 0);
1495
1496                                 ubi_err("could not erase old fastmap PEB");
1497                                 goto err;
1498                         }
1499
1500                         new_fm->e[i]->pnum = old_fm->e[i]->pnum;
1501                         new_fm->e[i]->ec = old_fm->e[i]->ec;
1502                 } else {
1503                         new_fm->e[i]->pnum = tmp_e->pnum;
1504                         new_fm->e[i]->ec = tmp_e->ec;
1505
1506                         if (old_fm)
1507                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1508                                                   old_fm->to_be_tortured[i]);
1509                 }
1510         }
1511
1512         spin_lock(&ubi->wl_lock);
1513         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1514         spin_unlock(&ubi->wl_lock);
1515
1516         if (old_fm) {
1517                 /* no fresh anchor PEB was found, reuse the old one */
1518                 if (!tmp_e) {
1519                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1520                         if (ret < 0) {
1521                                 int i;
1522                                 ubi_err("could not erase old anchor PEB");
1523
1524                                 for (i = 1; i < new_fm->used_blocks; i++)
1525                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1526                                                           i, 0);
1527                                 goto err;
1528                         }
1529
1530                         new_fm->e[0]->pnum = old_fm->e[0]->pnum;
1531                         new_fm->e[0]->ec = ret;
1532                 } else {
1533                         /* we've got a new anchor PEB, return the old one */
1534                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1535                                           old_fm->to_be_tortured[0]);
1536
1537                         new_fm->e[0]->pnum = tmp_e->pnum;
1538                         new_fm->e[0]->ec = tmp_e->ec;
1539                 }
1540         } else {
1541                 if (!tmp_e) {
1542                         int i;
1543                         ubi_err("could not find any anchor PEB");
1544
1545                         for (i = 1; i < new_fm->used_blocks; i++)
1546                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1547
1548                         ret = -ENOSPC;
1549                         goto err;
1550                 }
1551
1552                 new_fm->e[0]->pnum = tmp_e->pnum;
1553                 new_fm->e[0]->ec = tmp_e->ec;
1554         }
1555
1556         down_write(&ubi->work_sem);
1557         down_write(&ubi->fm_sem);
1558         ret = ubi_write_fastmap(ubi, new_fm);
1559         up_write(&ubi->fm_sem);
1560         up_write(&ubi->work_sem);
1561
1562         if (ret)
1563                 goto err;
1564
1565 out_unlock:
1566         mutex_unlock(&ubi->fm_mutex);
1567         kfree(old_fm);
1568         return ret;
1569
1570 err:
1571         kfree(new_fm);
1572
1573         ubi_warn("Unable to write new fastmap, err=%i", ret);
1574
1575         ret = 0;
1576         if (old_fm) {
1577                 ret = invalidate_fastmap(ubi, old_fm);
1578                 if (ret < 0)
1579                         ubi_err("Unable to invalidiate current fastmap!");
1580                 else if (ret)
1581                         ret = 0;
1582         }
1583         goto out_unlock;
1584 }