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