drivers/mtd/ubi/fastmap.c

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