drivers/mtd/ubi/fastmap.c

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This source file includes following definitions.
init_seen
free_seen
set_seen
self_check_seen
ubi_calc_fm_size
new_fm_vbuf
add_aeb
add_vol
assign_aeb_to_av
update_vol
process_pool_aeb
unmap_peb
scan_pool
count_fastmap_pebs
ubi_attach_fastmap
find_fm_anchor
clone_aeb
ubi_scan_fastmap
ubi_fastmap_init_checkmap
ubi_fastmap_destroy_checkmap
ubi_write_fastmap
erase_block
invalidate_fastmap
return_fm_pebs
ubi_update_fastmap
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2012 Linutronix GmbH
   4  * Copyright (c) 2014 sigma star gmbh
   5  * Author: Richard Weinberger <richard@nod.at>
   6  */
   7 
   8 #include <linux/crc32.h>
   9 #include <linux/bitmap.h>
  10 #include "ubi.h"
  11 
  12 /**
  13  * init_seen - allocate memory for used for debugging.
  14  * @ubi: UBI device description object
  15  */
  16 static inline unsigned long *init_seen(struct ubi_device *ubi)
  17 {
  18         unsigned long *ret;
  19 
  20         if (!ubi_dbg_chk_fastmap(ubi))
  21                 return NULL;
  22 
  23         ret = kcalloc(BITS_TO_LONGS(ubi->peb_count), sizeof(unsigned long),
  24                       GFP_KERNEL);
  25         if (!ret)
  26                 return ERR_PTR(-ENOMEM);
  27 
  28         return ret;
  29 }
  30 
  31 /**
  32  * free_seen - free the seen logic integer array.
  33  * @seen: integer array of @ubi->peb_count size
  34  */
  35 static inline void free_seen(unsigned long *seen)
  36 {
  37         kfree(seen);
  38 }
  39 
  40 /**
  41  * set_seen - mark a PEB as seen.
  42  * @ubi: UBI device description object
  43  * @pnum: The PEB to be makred as seen
  44  * @seen: integer array of @ubi->peb_count size
  45  */
  46 static inline void set_seen(struct ubi_device *ubi, int pnum, unsigned long *seen)
  47 {
  48         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  49                 return;
  50 
  51         set_bit(pnum, seen);
  52 }
  53 
  54 /**
  55  * self_check_seen - check whether all PEB have been seen by fastmap.
  56  * @ubi: UBI device description object
  57  * @seen: integer array of @ubi->peb_count size
  58  */
  59 static int self_check_seen(struct ubi_device *ubi, unsigned long *seen)
  60 {
  61         int pnum, ret = 0;
  62 
  63         if (!ubi_dbg_chk_fastmap(ubi) || !seen)
  64                 return 0;
  65 
  66         for (pnum = 0; pnum < ubi->peb_count; pnum++) {
  67                 if (!test_bit(pnum, seen) && ubi->lookuptbl[pnum]) {
  68                         ubi_err(ubi, "self-check failed for PEB %d, fastmap didn't see it", pnum);
  69                         ret = -EINVAL;
  70                 }
  71         }
  72 
  73         return ret;
  74 }
  75 
  76 /**
  77  * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
  78  * @ubi: UBI device description object
  79  */
  80 size_t ubi_calc_fm_size(struct ubi_device *ubi)
  81 {
  82         size_t size;
  83 
  84         size = sizeof(struct ubi_fm_sb) +
  85                 sizeof(struct ubi_fm_hdr) +
  86                 sizeof(struct ubi_fm_scan_pool) +
  87                 sizeof(struct ubi_fm_scan_pool) +
  88                 (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
  89                 (sizeof(struct ubi_fm_eba) +
  90                 (ubi->peb_count * sizeof(__be32))) +
  91                 sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
  92         return roundup(size, ubi->leb_size);
  93 }
  94 
  95 
  96 /**
  97  * new_fm_vhdr - allocate a new volume header for fastmap usage.
  98  * @ubi: UBI device description object
  99  * @vol_id: the VID of the new header
 100  *
 101  * Returns a new struct ubi_vid_hdr on success.
 102  * NULL indicates out of memory.
 103  */
 104 static struct ubi_vid_io_buf *new_fm_vbuf(struct ubi_device *ubi, int vol_id)
 105 {
 106         struct ubi_vid_io_buf *new;
 107         struct ubi_vid_hdr *vh;
 108 
 109         new = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 110         if (!new)
 111                 goto out;
 112 
 113         vh = ubi_get_vid_hdr(new);
 114         vh->vol_type = UBI_VID_DYNAMIC;
 115         vh->vol_id = cpu_to_be32(vol_id);
 116 
 117         /* UBI implementations without fastmap support have to delete the
 118          * fastmap.
 119          */
 120         vh->compat = UBI_COMPAT_DELETE;
 121 
 122 out:
 123         return new;
 124 }
 125 
 126 /**
 127  * add_aeb - create and add a attach erase block to a given list.
 128  * @ai: UBI attach info object
 129  * @list: the target list
 130  * @pnum: PEB number of the new attach erase block
 131  * @ec: erease counter of the new LEB
 132  * @scrub: scrub this PEB after attaching
 133  *
 134  * Returns 0 on success, < 0 indicates an internal error.
 135  */
 136 static int add_aeb(struct ubi_attach_info *ai, struct list_head *list,
 137                    int pnum, int ec, int scrub)
 138 {
 139         struct ubi_ainf_peb *aeb;
 140 
 141         aeb = ubi_alloc_aeb(ai, pnum, ec);
 142         if (!aeb)
 143                 return -ENOMEM;
 144 
 145         aeb->lnum = -1;
 146         aeb->scrub = scrub;
 147         aeb->copy_flag = aeb->sqnum = 0;
 148 
 149         ai->ec_sum += aeb->ec;
 150         ai->ec_count++;
 151 
 152         if (ai->max_ec < aeb->ec)
 153                 ai->max_ec = aeb->ec;
 154 
 155         if (ai->min_ec > aeb->ec)
 156                 ai->min_ec = aeb->ec;
 157 
 158         list_add_tail(&aeb->u.list, list);
 159 
 160         return 0;
 161 }
 162 
 163 /**
 164  * add_vol - create and add a new volume to ubi_attach_info.
 165  * @ai: ubi_attach_info object
 166  * @vol_id: VID of the new volume
 167  * @used_ebs: number of used EBS
 168  * @data_pad: data padding value of the new volume
 169  * @vol_type: volume type
 170  * @last_eb_bytes: number of bytes in the last LEB
 171  *
 172  * Returns the new struct ubi_ainf_volume on success.
 173  * NULL indicates an error.
 174  */
 175 static struct ubi_ainf_volume *add_vol(struct ubi_attach_info *ai, int vol_id,
 176                                        int used_ebs, int data_pad, u8 vol_type,
 177                                        int last_eb_bytes)
 178 {
 179         struct ubi_ainf_volume *av;
 180 
 181         av = ubi_add_av(ai, vol_id);
 182         if (IS_ERR(av))
 183                 return av;
 184 
 185         av->data_pad = data_pad;
 186         av->last_data_size = last_eb_bytes;
 187         av->compat = 0;
 188         av->vol_type = vol_type;
 189         if (av->vol_type == UBI_STATIC_VOLUME)
 190                 av->used_ebs = used_ebs;
 191 
 192         dbg_bld("found volume (ID %i)", vol_id);
 193         return av;
 194 }
 195 
 196 /**
 197  * assign_aeb_to_av - assigns a SEB to a given ainf_volume and removes it
 198  * from it's original list.
 199  * @ai: ubi_attach_info object
 200  * @aeb: the to be assigned SEB
 201  * @av: target scan volume
 202  */
 203 static void assign_aeb_to_av(struct ubi_attach_info *ai,
 204                              struct ubi_ainf_peb *aeb,
 205                              struct ubi_ainf_volume *av)
 206 {
 207         struct ubi_ainf_peb *tmp_aeb;
 208         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 209 
 210         while (*p) {
 211                 parent = *p;
 212 
 213                 tmp_aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 214                 if (aeb->lnum != tmp_aeb->lnum) {
 215                         if (aeb->lnum < tmp_aeb->lnum)
 216                                 p = &(*p)->rb_left;
 217                         else
 218                                 p = &(*p)->rb_right;
 219 
 220                         continue;
 221                 } else
 222                         break;
 223         }
 224 
 225         list_del(&aeb->u.list);
 226         av->leb_count++;
 227 
 228         rb_link_node(&aeb->u.rb, parent, p);
 229         rb_insert_color(&aeb->u.rb, &av->root);
 230 }
 231 
 232 /**
 233  * update_vol - inserts or updates a LEB which was found a pool.
 234  * @ubi: the UBI device object
 235  * @ai: attach info object
 236  * @av: the volume this LEB belongs to
 237  * @new_vh: the volume header derived from new_aeb
 238  * @new_aeb: the AEB to be examined
 239  *
 240  * Returns 0 on success, < 0 indicates an internal error.
 241  */
 242 static int update_vol(struct ubi_device *ubi, struct ubi_attach_info *ai,
 243                       struct ubi_ainf_volume *av, struct ubi_vid_hdr *new_vh,
 244                       struct ubi_ainf_peb *new_aeb)
 245 {
 246         struct rb_node **p = &av->root.rb_node, *parent = NULL;
 247         struct ubi_ainf_peb *aeb, *victim;
 248         int cmp_res;
 249 
 250         while (*p) {
 251                 parent = *p;
 252                 aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
 253 
 254                 if (be32_to_cpu(new_vh->lnum) != aeb->lnum) {
 255                         if (be32_to_cpu(new_vh->lnum) < aeb->lnum)
 256                                 p = &(*p)->rb_left;
 257                         else
 258                                 p = &(*p)->rb_right;
 259 
 260                         continue;
 261                 }
 262 
 263                 /* This case can happen if the fastmap gets written
 264                  * because of a volume change (creation, deletion, ..).
 265                  * Then a PEB can be within the persistent EBA and the pool.
 266                  */
 267                 if (aeb->pnum == new_aeb->pnum) {
 268                         ubi_assert(aeb->lnum == new_aeb->lnum);
 269                         ubi_free_aeb(ai, new_aeb);
 270 
 271                         return 0;
 272                 }
 273 
 274                 cmp_res = ubi_compare_lebs(ubi, aeb, new_aeb->pnum, new_vh);
 275                 if (cmp_res < 0)
 276                         return cmp_res;
 277 
 278                 /* new_aeb is newer */
 279                 if (cmp_res & 1) {
 280                         victim = ubi_alloc_aeb(ai, aeb->pnum, aeb->ec);
 281                         if (!victim)
 282                                 return -ENOMEM;
 283 
 284                         list_add_tail(&victim->u.list, &ai->erase);
 285 
 286                         if (av->highest_lnum == be32_to_cpu(new_vh->lnum))
 287                                 av->last_data_size =
 288                                         be32_to_cpu(new_vh->data_size);
 289 
 290                         dbg_bld("vol %i: AEB %i's PEB %i is the newer",
 291                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 292 
 293                         aeb->ec = new_aeb->ec;
 294                         aeb->pnum = new_aeb->pnum;
 295                         aeb->copy_flag = new_vh->copy_flag;
 296                         aeb->scrub = new_aeb->scrub;
 297                         aeb->sqnum = new_aeb->sqnum;
 298                         ubi_free_aeb(ai, new_aeb);
 299 
 300                 /* new_aeb is older */
 301                 } else {
 302                         dbg_bld("vol %i: AEB %i's PEB %i is old, dropping it",
 303                                 av->vol_id, aeb->lnum, new_aeb->pnum);
 304                         list_add_tail(&new_aeb->u.list, &ai->erase);
 305                 }
 306 
 307                 return 0;
 308         }
 309         /* This LEB is new, let's add it to the volume */
 310 
 311         if (av->highest_lnum <= be32_to_cpu(new_vh->lnum)) {
 312                 av->highest_lnum = be32_to_cpu(new_vh->lnum);
 313                 av->last_data_size = be32_to_cpu(new_vh->data_size);
 314         }
 315 
 316         if (av->vol_type == UBI_STATIC_VOLUME)
 317                 av->used_ebs = be32_to_cpu(new_vh->used_ebs);
 318 
 319         av->leb_count++;
 320 
 321         rb_link_node(&new_aeb->u.rb, parent, p);
 322         rb_insert_color(&new_aeb->u.rb, &av->root);
 323 
 324         return 0;
 325 }
 326 
 327 /**
 328  * process_pool_aeb - we found a non-empty PEB in a pool.
 329  * @ubi: UBI device object
 330  * @ai: attach info object
 331  * @new_vh: the volume header derived from new_aeb
 332  * @new_aeb: the AEB to be examined
 333  *
 334  * Returns 0 on success, < 0 indicates an internal error.
 335  */
 336 static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 337                             struct ubi_vid_hdr *new_vh,
 338                             struct ubi_ainf_peb *new_aeb)
 339 {
 340         int vol_id = be32_to_cpu(new_vh->vol_id);
 341         struct ubi_ainf_volume *av;
 342 
 343         if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 344                 ubi_free_aeb(ai, new_aeb);
 345 
 346                 return 0;
 347         }
 348 
 349         /* Find the volume this SEB belongs to */
 350         av = ubi_find_av(ai, vol_id);
 351         if (!av) {
 352                 ubi_err(ubi, "orphaned volume in fastmap pool!");
 353                 ubi_free_aeb(ai, new_aeb);
 354                 return UBI_BAD_FASTMAP;
 355         }
 356 
 357         ubi_assert(vol_id == av->vol_id);
 358 
 359         return update_vol(ubi, ai, av, new_vh, new_aeb);
 360 }
 361 
 362 /**
 363  * unmap_peb - unmap a PEB.
 364  * If fastmap detects a free PEB in the pool it has to check whether
 365  * this PEB has been unmapped after writing the fastmap.
 366  *
 367  * @ai: UBI attach info object
 368  * @pnum: The PEB to be unmapped
 369  */
 370 static void unmap_peb(struct ubi_attach_info *ai, int pnum)
 371 {
 372         struct ubi_ainf_volume *av;
 373         struct rb_node *node, *node2;
 374         struct ubi_ainf_peb *aeb;
 375 
 376         ubi_rb_for_each_entry(node, av, &ai->volumes, rb) {
 377                 ubi_rb_for_each_entry(node2, aeb, &av->root, u.rb) {
 378                         if (aeb->pnum == pnum) {
 379                                 rb_erase(&aeb->u.rb, &av->root);
 380                                 av->leb_count--;
 381                                 ubi_free_aeb(ai, aeb);
 382                                 return;
 383                         }
 384                 }
 385         }
 386 }
 387 
 388 /**
 389  * scan_pool - scans a pool for changed (no longer empty PEBs).
 390  * @ubi: UBI device object
 391  * @ai: attach info object
 392  * @pebs: an array of all PEB numbers in the to be scanned pool
 393  * @pool_size: size of the pool (number of entries in @pebs)
 394  * @max_sqnum: pointer to the maximal sequence number
 395  * @free: list of PEBs which are most likely free (and go into @ai->free)
 396  *
 397  * Returns 0 on success, if the pool is unusable UBI_BAD_FASTMAP is returned.
 398  * < 0 indicates an internal error.
 399  */
 400 static int scan_pool(struct ubi_device *ubi, struct ubi_attach_info *ai,
 401                      __be32 *pebs, int pool_size, unsigned long long *max_sqnum,
 402                      struct list_head *free)
 403 {
 404         struct ubi_vid_io_buf *vb;
 405         struct ubi_vid_hdr *vh;
 406         struct ubi_ec_hdr *ech;
 407         struct ubi_ainf_peb *new_aeb;
 408         int i, pnum, err, ret = 0;
 409 
 410         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 411         if (!ech)
 412                 return -ENOMEM;
 413 
 414         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 415         if (!vb) {
 416                 kfree(ech);
 417                 return -ENOMEM;
 418         }
 419 
 420         vh = ubi_get_vid_hdr(vb);
 421 
 422         dbg_bld("scanning fastmap pool: size = %i", pool_size);
 423 
 424         /*
 425          * Now scan all PEBs in the pool to find changes which have been made
 426          * after the creation of the fastmap
 427          */
 428         for (i = 0; i < pool_size; i++) {
 429                 int scrub = 0;
 430                 int image_seq;
 431 
 432                 pnum = be32_to_cpu(pebs[i]);
 433 
 434                 if (ubi_io_is_bad(ubi, pnum)) {
 435                         ubi_err(ubi, "bad PEB in fastmap pool!");
 436                         ret = UBI_BAD_FASTMAP;
 437                         goto out;
 438                 }
 439 
 440                 err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 441                 if (err && err != UBI_IO_BITFLIPS) {
 442                         ubi_err(ubi, "unable to read EC header! PEB:%i err:%i",
 443                                 pnum, err);
 444                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 445                         goto out;
 446                 } else if (err == UBI_IO_BITFLIPS)
 447                         scrub = 1;
 448 
 449                 /*
 450                  * Older UBI implementations have image_seq set to zero, so
 451                  * we shouldn't fail if image_seq == 0.
 452                  */
 453                 image_seq = be32_to_cpu(ech->image_seq);
 454 
 455                 if (image_seq && (image_seq != ubi->image_seq)) {
 456                         ubi_err(ubi, "bad image seq: 0x%x, expected: 0x%x",
 457                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 458                         ret = UBI_BAD_FASTMAP;
 459                         goto out;
 460                 }
 461 
 462                 err = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 463                 if (err == UBI_IO_FF || err == UBI_IO_FF_BITFLIPS) {
 464                         unsigned long long ec = be64_to_cpu(ech->ec);
 465                         unmap_peb(ai, pnum);
 466                         dbg_bld("Adding PEB to free: %i", pnum);
 467 
 468                         if (err == UBI_IO_FF_BITFLIPS)
 469                                 scrub = 1;
 470 
 471                         add_aeb(ai, free, pnum, ec, scrub);
 472                         continue;
 473                 } else if (err == 0 || err == UBI_IO_BITFLIPS) {
 474                         dbg_bld("Found non empty PEB:%i in pool", pnum);
 475 
 476                         if (err == UBI_IO_BITFLIPS)
 477                                 scrub = 1;
 478 
 479                         new_aeb = ubi_alloc_aeb(ai, pnum, be64_to_cpu(ech->ec));
 480                         if (!new_aeb) {
 481                                 ret = -ENOMEM;
 482                                 goto out;
 483                         }
 484 
 485                         new_aeb->lnum = be32_to_cpu(vh->lnum);
 486                         new_aeb->sqnum = be64_to_cpu(vh->sqnum);
 487                         new_aeb->copy_flag = vh->copy_flag;
 488                         new_aeb->scrub = scrub;
 489 
 490                         if (*max_sqnum < new_aeb->sqnum)
 491                                 *max_sqnum = new_aeb->sqnum;
 492 
 493                         err = process_pool_aeb(ubi, ai, vh, new_aeb);
 494                         if (err) {
 495                                 ret = err > 0 ? UBI_BAD_FASTMAP : err;
 496                                 goto out;
 497                         }
 498                 } else {
 499                         /* We are paranoid and fall back to scanning mode */
 500                         ubi_err(ubi, "fastmap pool PEBs contains damaged PEBs!");
 501                         ret = err > 0 ? UBI_BAD_FASTMAP : err;
 502                         goto out;
 503                 }
 504 
 505         }
 506 
 507 out:
 508         ubi_free_vid_buf(vb);
 509         kfree(ech);
 510         return ret;
 511 }
 512 
 513 /**
 514  * count_fastmap_pebs - Counts the PEBs found by fastmap.
 515  * @ai: The UBI attach info object
 516  */
 517 static int count_fastmap_pebs(struct ubi_attach_info *ai)
 518 {
 519         struct ubi_ainf_peb *aeb;
 520         struct ubi_ainf_volume *av;
 521         struct rb_node *rb1, *rb2;
 522         int n = 0;
 523 
 524         list_for_each_entry(aeb, &ai->erase, u.list)
 525                 n++;
 526 
 527         list_for_each_entry(aeb, &ai->free, u.list)
 528                 n++;
 529 
 530         ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb)
 531                 ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb)
 532                         n++;
 533 
 534         return n;
 535 }
 536 
 537 /**
 538  * ubi_attach_fastmap - creates ubi_attach_info from a fastmap.
 539  * @ubi: UBI device object
 540  * @ai: UBI attach info object
 541  * @fm: the fastmap to be attached
 542  *
 543  * Returns 0 on success, UBI_BAD_FASTMAP if the found fastmap was unusable.
 544  * < 0 indicates an internal error.
 545  */
 546 static int ubi_attach_fastmap(struct ubi_device *ubi,
 547                               struct ubi_attach_info *ai,
 548                               struct ubi_fastmap_layout *fm)
 549 {
 550         struct list_head used, free;
 551         struct ubi_ainf_volume *av;
 552         struct ubi_ainf_peb *aeb, *tmp_aeb, *_tmp_aeb;
 553         struct ubi_fm_sb *fmsb;
 554         struct ubi_fm_hdr *fmhdr;
 555         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
 556         struct ubi_fm_ec *fmec;
 557         struct ubi_fm_volhdr *fmvhdr;
 558         struct ubi_fm_eba *fm_eba;
 559         int ret, i, j, pool_size, wl_pool_size;
 560         size_t fm_pos = 0, fm_size = ubi->fm_size;
 561         unsigned long long max_sqnum = 0;
 562         void *fm_raw = ubi->fm_buf;
 563 
 564         INIT_LIST_HEAD(&used);
 565         INIT_LIST_HEAD(&free);
 566         ai->min_ec = UBI_MAX_ERASECOUNTER;
 567 
 568         fmsb = (struct ubi_fm_sb *)(fm_raw);
 569         ai->max_sqnum = fmsb->sqnum;
 570         fm_pos += sizeof(struct ubi_fm_sb);
 571         if (fm_pos >= fm_size)
 572                 goto fail_bad;
 573 
 574         fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
 575         fm_pos += sizeof(*fmhdr);
 576         if (fm_pos >= fm_size)
 577                 goto fail_bad;
 578 
 579         if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
 580                 ubi_err(ubi, "bad fastmap header magic: 0x%x, expected: 0x%x",
 581                         be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
 582                 goto fail_bad;
 583         }
 584 
 585         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 586         fm_pos += sizeof(*fmpl);
 587         if (fm_pos >= fm_size)
 588                 goto fail_bad;
 589         if (be32_to_cpu(fmpl->magic) != UBI_FM_POOL_MAGIC) {
 590                 ubi_err(ubi, "bad fastmap pool magic: 0x%x, expected: 0x%x",
 591                         be32_to_cpu(fmpl->magic), UBI_FM_POOL_MAGIC);
 592                 goto fail_bad;
 593         }
 594 
 595         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
 596         fm_pos += sizeof(*fmpl_wl);
 597         if (fm_pos >= fm_size)
 598                 goto fail_bad;
 599         if (be32_to_cpu(fmpl_wl->magic) != UBI_FM_POOL_MAGIC) {
 600                 ubi_err(ubi, "bad fastmap WL pool magic: 0x%x, expected: 0x%x",
 601                         be32_to_cpu(fmpl_wl->magic), UBI_FM_POOL_MAGIC);
 602                 goto fail_bad;
 603         }
 604 
 605         pool_size = be16_to_cpu(fmpl->size);
 606         wl_pool_size = be16_to_cpu(fmpl_wl->size);
 607         fm->max_pool_size = be16_to_cpu(fmpl->max_size);
 608         fm->max_wl_pool_size = be16_to_cpu(fmpl_wl->max_size);
 609 
 610         if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
 611                 ubi_err(ubi, "bad pool size: %i", pool_size);
 612                 goto fail_bad;
 613         }
 614 
 615         if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
 616                 ubi_err(ubi, "bad WL pool size: %i", wl_pool_size);
 617                 goto fail_bad;
 618         }
 619 
 620 
 621         if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
 622             fm->max_pool_size < 0) {
 623                 ubi_err(ubi, "bad maximal pool size: %i", fm->max_pool_size);
 624                 goto fail_bad;
 625         }
 626 
 627         if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
 628             fm->max_wl_pool_size < 0) {
 629                 ubi_err(ubi, "bad maximal WL pool size: %i",
 630                         fm->max_wl_pool_size);
 631                 goto fail_bad;
 632         }
 633 
 634         /* read EC values from free list */
 635         for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
 636                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 637                 fm_pos += sizeof(*fmec);
 638                 if (fm_pos >= fm_size)
 639                         goto fail_bad;
 640 
 641                 add_aeb(ai, &ai->free, be32_to_cpu(fmec->pnum),
 642                         be32_to_cpu(fmec->ec), 0);
 643         }
 644 
 645         /* read EC values from used list */
 646         for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
 647                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 648                 fm_pos += sizeof(*fmec);
 649                 if (fm_pos >= fm_size)
 650                         goto fail_bad;
 651 
 652                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 653                         be32_to_cpu(fmec->ec), 0);
 654         }
 655 
 656         /* read EC values from scrub list */
 657         for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
 658                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 659                 fm_pos += sizeof(*fmec);
 660                 if (fm_pos >= fm_size)
 661                         goto fail_bad;
 662 
 663                 add_aeb(ai, &used, be32_to_cpu(fmec->pnum),
 664                         be32_to_cpu(fmec->ec), 1);
 665         }
 666 
 667         /* read EC values from erase list */
 668         for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
 669                 fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
 670                 fm_pos += sizeof(*fmec);
 671                 if (fm_pos >= fm_size)
 672                         goto fail_bad;
 673 
 674                 add_aeb(ai, &ai->erase, be32_to_cpu(fmec->pnum),
 675                         be32_to_cpu(fmec->ec), 1);
 676         }
 677 
 678         ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);
 679         ai->bad_peb_count = be32_to_cpu(fmhdr->bad_peb_count);
 680 
 681         /* Iterate over all volumes and read their EBA table */
 682         for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
 683                 fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
 684                 fm_pos += sizeof(*fmvhdr);
 685                 if (fm_pos >= fm_size)
 686                         goto fail_bad;
 687 
 688                 if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
 689                         ubi_err(ubi, "bad fastmap vol header magic: 0x%x, expected: 0x%x",
 690                                 be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
 691                         goto fail_bad;
 692                 }
 693 
 694                 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id),
 695                              be32_to_cpu(fmvhdr->used_ebs),
 696                              be32_to_cpu(fmvhdr->data_pad),
 697                              fmvhdr->vol_type,
 698                              be32_to_cpu(fmvhdr->last_eb_bytes));
 699 
 700                 if (IS_ERR(av)) {
 701                         if (PTR_ERR(av) == -EEXIST)
 702                                 ubi_err(ubi, "volume (ID %i) already exists",
 703                                         fmvhdr->vol_id);
 704 
 705                         goto fail_bad;
 706                 }
 707 
 708                 ai->vols_found++;
 709                 if (ai->highest_vol_id < be32_to_cpu(fmvhdr->vol_id))
 710                         ai->highest_vol_id = be32_to_cpu(fmvhdr->vol_id);
 711 
 712                 fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
 713                 fm_pos += sizeof(*fm_eba);
 714                 fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
 715                 if (fm_pos >= fm_size)
 716                         goto fail_bad;
 717 
 718                 if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
 719                         ubi_err(ubi, "bad fastmap EBA header magic: 0x%x, expected: 0x%x",
 720                                 be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
 721                         goto fail_bad;
 722                 }
 723 
 724                 for (j = 0; j < be32_to_cpu(fm_eba->reserved_pebs); j++) {
 725                         int pnum = be32_to_cpu(fm_eba->pnum[j]);
 726 
 727                         if (pnum < 0)
 728                                 continue;
 729 
 730                         aeb = NULL;
 731                         list_for_each_entry(tmp_aeb, &used, u.list) {
 732                                 if (tmp_aeb->pnum == pnum) {
 733                                         aeb = tmp_aeb;
 734                                         break;
 735                                 }
 736                         }
 737 
 738                         if (!aeb) {
 739                                 ubi_err(ubi, "PEB %i is in EBA but not in used list", pnum);
 740                                 goto fail_bad;
 741                         }
 742 
 743                         aeb->lnum = j;
 744 
 745                         if (av->highest_lnum <= aeb->lnum)
 746                                 av->highest_lnum = aeb->lnum;
 747 
 748                         assign_aeb_to_av(ai, aeb, av);
 749 
 750                         dbg_bld("inserting PEB:%i (LEB %i) to vol %i",
 751                                 aeb->pnum, aeb->lnum, av->vol_id);
 752                 }
 753         }
 754 
 755         ret = scan_pool(ubi, ai, fmpl->pebs, pool_size, &max_sqnum, &free);
 756         if (ret)
 757                 goto fail;
 758 
 759         ret = scan_pool(ubi, ai, fmpl_wl->pebs, wl_pool_size, &max_sqnum, &free);
 760         if (ret)
 761                 goto fail;
 762 
 763         if (max_sqnum > ai->max_sqnum)
 764                 ai->max_sqnum = max_sqnum;
 765 
 766         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list)
 767                 list_move_tail(&tmp_aeb->u.list, &ai->free);
 768 
 769         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list)
 770                 list_move_tail(&tmp_aeb->u.list, &ai->erase);
 771 
 772         ubi_assert(list_empty(&free));
 773 
 774         /*
 775          * If fastmap is leaking PEBs (must not happen), raise a
 776          * fat warning and fall back to scanning mode.
 777          * We do this here because in ubi_wl_init() it's too late
 778          * and we cannot fall back to scanning.
 779          */
 780         if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
 781                     ai->bad_peb_count - fm->used_blocks))
 782                 goto fail_bad;
 783 
 784         return 0;
 785 
 786 fail_bad:
 787         ret = UBI_BAD_FASTMAP;
 788 fail:
 789         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &used, u.list) {
 790                 list_del(&tmp_aeb->u.list);
 791                 ubi_free_aeb(ai, tmp_aeb);
 792         }
 793         list_for_each_entry_safe(tmp_aeb, _tmp_aeb, &free, u.list) {
 794                 list_del(&tmp_aeb->u.list);
 795                 ubi_free_aeb(ai, tmp_aeb);
 796         }
 797 
 798         return ret;
 799 }
 800 
 801 /**
 802  * find_fm_anchor - find the most recent Fastmap superblock (anchor)
 803  * @ai: UBI attach info to be filled
 804  */
 805 static int find_fm_anchor(struct ubi_attach_info *ai)
 806 {
 807         int ret = -1;
 808         struct ubi_ainf_peb *aeb;
 809         unsigned long long max_sqnum = 0;
 810 
 811         list_for_each_entry(aeb, &ai->fastmap, u.list) {
 812                 if (aeb->vol_id == UBI_FM_SB_VOLUME_ID && aeb->sqnum > max_sqnum) {
 813                         max_sqnum = aeb->sqnum;
 814                         ret = aeb->pnum;
 815                 }
 816         }
 817 
 818         return ret;
 819 }
 820 
 821 static struct ubi_ainf_peb *clone_aeb(struct ubi_attach_info *ai,
 822                                       struct ubi_ainf_peb *old)
 823 {
 824         struct ubi_ainf_peb *new;
 825 
 826         new = ubi_alloc_aeb(ai, old->pnum, old->ec);
 827         if (!new)
 828                 return NULL;
 829 
 830         new->vol_id = old->vol_id;
 831         new->sqnum = old->sqnum;
 832         new->lnum = old->lnum;
 833         new->scrub = old->scrub;
 834         new->copy_flag = old->copy_flag;
 835 
 836         return new;
 837 }
 838 
 839 /**
 840  * ubi_scan_fastmap - scan the fastmap.
 841  * @ubi: UBI device object
 842  * @ai: UBI attach info to be filled
 843  * @scan_ai: UBI attach info from the first 64 PEBs,
 844  *           used to find the most recent Fastmap data structure
 845  *
 846  * Returns 0 on success, UBI_NO_FASTMAP if no fastmap was found,
 847  * UBI_BAD_FASTMAP if one was found but is not usable.
 848  * < 0 indicates an internal error.
 849  */
 850 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
 851                      struct ubi_attach_info *scan_ai)
 852 {
 853         struct ubi_fm_sb *fmsb, *fmsb2;
 854         struct ubi_vid_io_buf *vb;
 855         struct ubi_vid_hdr *vh;
 856         struct ubi_ec_hdr *ech;
 857         struct ubi_fastmap_layout *fm;
 858         struct ubi_ainf_peb *aeb;
 859         int i, used_blocks, pnum, fm_anchor, ret = 0;
 860         size_t fm_size;
 861         __be32 crc, tmp_crc;
 862         unsigned long long sqnum = 0;
 863 
 864         fm_anchor = find_fm_anchor(scan_ai);
 865         if (fm_anchor < 0)
 866                 return UBI_NO_FASTMAP;
 867 
 868         /* Copy all (possible) fastmap blocks into our new attach structure. */
 869         list_for_each_entry(aeb, &scan_ai->fastmap, u.list) {
 870                 struct ubi_ainf_peb *new;
 871 
 872                 new = clone_aeb(ai, aeb);
 873                 if (!new)
 874                         return -ENOMEM;
 875 
 876                 list_add(&new->u.list, &ai->fastmap);
 877         }
 878 
 879         down_write(&ubi->fm_protect);
 880         memset(ubi->fm_buf, 0, ubi->fm_size);
 881 
 882         fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL);
 883         if (!fmsb) {
 884                 ret = -ENOMEM;
 885                 goto out;
 886         }
 887 
 888         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
 889         if (!fm) {
 890                 ret = -ENOMEM;
 891                 kfree(fmsb);
 892                 goto out;
 893         }
 894 
 895         ret = ubi_io_read_data(ubi, fmsb, fm_anchor, 0, sizeof(*fmsb));
 896         if (ret && ret != UBI_IO_BITFLIPS)
 897                 goto free_fm_sb;
 898         else if (ret == UBI_IO_BITFLIPS)
 899                 fm->to_be_tortured[0] = 1;
 900 
 901         if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
 902                 ubi_err(ubi, "bad super block magic: 0x%x, expected: 0x%x",
 903                         be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
 904                 ret = UBI_BAD_FASTMAP;
 905                 goto free_fm_sb;
 906         }
 907 
 908         if (fmsb->version != UBI_FM_FMT_VERSION) {
 909                 ubi_err(ubi, "bad fastmap version: %i, expected: %i",
 910                         fmsb->version, UBI_FM_FMT_VERSION);
 911                 ret = UBI_BAD_FASTMAP;
 912                 goto free_fm_sb;
 913         }
 914 
 915         used_blocks = be32_to_cpu(fmsb->used_blocks);
 916         if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
 917                 ubi_err(ubi, "number of fastmap blocks is invalid: %i",
 918                         used_blocks);
 919                 ret = UBI_BAD_FASTMAP;
 920                 goto free_fm_sb;
 921         }
 922 
 923         fm_size = ubi->leb_size * used_blocks;
 924         if (fm_size != ubi->fm_size) {
 925                 ubi_err(ubi, "bad fastmap size: %zi, expected: %zi",
 926                         fm_size, ubi->fm_size);
 927                 ret = UBI_BAD_FASTMAP;
 928                 goto free_fm_sb;
 929         }
 930 
 931         ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
 932         if (!ech) {
 933                 ret = -ENOMEM;
 934                 goto free_fm_sb;
 935         }
 936 
 937         vb = ubi_alloc_vid_buf(ubi, GFP_KERNEL);
 938         if (!vb) {
 939                 ret = -ENOMEM;
 940                 goto free_hdr;
 941         }
 942 
 943         vh = ubi_get_vid_hdr(vb);
 944 
 945         for (i = 0; i < used_blocks; i++) {
 946                 int image_seq;
 947 
 948                 pnum = be32_to_cpu(fmsb->block_loc[i]);
 949 
 950                 if (ubi_io_is_bad(ubi, pnum)) {
 951                         ret = UBI_BAD_FASTMAP;
 952                         goto free_hdr;
 953                 }
 954 
 955                 if (i == 0 && pnum != fm_anchor) {
 956                         ubi_err(ubi, "Fastmap anchor PEB mismatch: PEB: %i vs. %i",
 957                                 pnum, fm_anchor);
 958                         ret = UBI_BAD_FASTMAP;
 959                         goto free_hdr;
 960                 }
 961 
 962                 ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 963                 if (ret && ret != UBI_IO_BITFLIPS) {
 964                         ubi_err(ubi, "unable to read fastmap block# %i EC (PEB: %i)",
 965                                 i, pnum);
 966                         if (ret > 0)
 967                                 ret = UBI_BAD_FASTMAP;
 968                         goto free_hdr;
 969                 } else if (ret == UBI_IO_BITFLIPS)
 970                         fm->to_be_tortured[i] = 1;
 971 
 972                 image_seq = be32_to_cpu(ech->image_seq);
 973                 if (!ubi->image_seq)
 974                         ubi->image_seq = image_seq;
 975 
 976                 /*
 977                  * Older UBI implementations have image_seq set to zero, so
 978                  * we shouldn't fail if image_seq == 0.
 979                  */
 980                 if (image_seq && (image_seq != ubi->image_seq)) {
 981                         ubi_err(ubi, "wrong image seq:%d instead of %d",
 982                                 be32_to_cpu(ech->image_seq), ubi->image_seq);
 983                         ret = UBI_BAD_FASTMAP;
 984                         goto free_hdr;
 985                 }
 986 
 987                 ret = ubi_io_read_vid_hdr(ubi, pnum, vb, 0);
 988                 if (ret && ret != UBI_IO_BITFLIPS) {
 989                         ubi_err(ubi, "unable to read fastmap block# %i (PEB: %i)",
 990                                 i, pnum);
 991                         goto free_hdr;
 992                 }
 993 
 994                 if (i == 0) {
 995                         if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
 996                                 ubi_err(ubi, "bad fastmap anchor vol_id: 0x%x, expected: 0x%x",
 997                                         be32_to_cpu(vh->vol_id),
 998                                         UBI_FM_SB_VOLUME_ID);
 999                                 ret = UBI_BAD_FASTMAP;
1000                                 goto free_hdr;
1001                         }
1002                 } else {
1003                         if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
1004                                 ubi_err(ubi, "bad fastmap data vol_id: 0x%x, 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_data(ubi, ubi->fm_buf + (ubi->leb_size * i),
1016                                        pnum, 0, ubi->leb_size);
1017                 if (ret && ret != UBI_IO_BITFLIPS) {
1018                         ubi_err(ubi, "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(ubi, "fastmap data CRC is invalid");
1033                 ubi_err(ubi, "CRC should be: 0x%x, calc: 0x%x",
1034                         tmp_crc, crc);
1035                 ret = UBI_BAD_FASTMAP;
1036                 goto free_hdr;
1037         }
1038 
1039         fmsb2->sqnum = sqnum;
1040 
1041         fm->used_blocks = used_blocks;
1042 
1043         ret = ubi_attach_fastmap(ubi, ai, fm);
1044         if (ret) {
1045                 if (ret > 0)
1046                         ret = UBI_BAD_FASTMAP;
1047                 goto free_hdr;
1048         }
1049 
1050         for (i = 0; i < used_blocks; i++) {
1051                 struct ubi_wl_entry *e;
1052 
1053                 e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
1054                 if (!e) {
1055                         while (i--)
1056                                 kmem_cache_free(ubi_wl_entry_slab, fm->e[i]);
1057 
1058                         ret = -ENOMEM;
1059                         goto free_hdr;
1060                 }
1061 
1062                 e->pnum = be32_to_cpu(fmsb2->block_loc[i]);
1063                 e->ec = be32_to_cpu(fmsb2->block_ec[i]);
1064                 fm->e[i] = e;
1065         }
1066 
1067         ubi->fm = fm;
1068         ubi->fm_pool.max_size = ubi->fm->max_pool_size;
1069         ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
1070         ubi_msg(ubi, "attached by fastmap");
1071         ubi_msg(ubi, "fastmap pool size: %d", ubi->fm_pool.max_size);
1072         ubi_msg(ubi, "fastmap WL pool size: %d",
1073                 ubi->fm_wl_pool.max_size);
1074         ubi->fm_disabled = 0;
1075         ubi->fast_attach = 1;
1076 
1077         ubi_free_vid_buf(vb);
1078         kfree(ech);
1079 out:
1080         up_write(&ubi->fm_protect);
1081         if (ret == UBI_BAD_FASTMAP)
1082                 ubi_err(ubi, "Attach by fastmap failed, doing a full scan!");
1083         return ret;
1084 
1085 free_hdr:
1086         ubi_free_vid_buf(vb);
1087         kfree(ech);
1088 free_fm_sb:
1089         kfree(fmsb);
1090         kfree(fm);
1091         goto out;
1092 }
1093 
1094 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count)
1095 {
1096         struct ubi_device *ubi = vol->ubi;
1097 
1098         if (!ubi->fast_attach)
1099                 return 0;
1100 
1101         vol->checkmap = kcalloc(BITS_TO_LONGS(leb_count), sizeof(unsigned long),
1102                                 GFP_KERNEL);
1103         if (!vol->checkmap)
1104                 return -ENOMEM;
1105 
1106         return 0;
1107 }
1108 
1109 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol)
1110 {
1111         kfree(vol->checkmap);
1112 }
1113 
1114 /**
1115  * ubi_write_fastmap - writes a fastmap.
1116  * @ubi: UBI device object
1117  * @new_fm: the to be written fastmap
1118  *
1119  * Returns 0 on success, < 0 indicates an internal error.
1120  */
1121 static int ubi_write_fastmap(struct ubi_device *ubi,
1122                              struct ubi_fastmap_layout *new_fm)
1123 {
1124         size_t fm_pos = 0;
1125         void *fm_raw;
1126         struct ubi_fm_sb *fmsb;
1127         struct ubi_fm_hdr *fmh;
1128         struct ubi_fm_scan_pool *fmpl, *fmpl_wl;
1129         struct ubi_fm_ec *fec;
1130         struct ubi_fm_volhdr *fvh;
1131         struct ubi_fm_eba *feba;
1132         struct ubi_wl_entry *wl_e;
1133         struct ubi_volume *vol;
1134         struct ubi_vid_io_buf *avbuf, *dvbuf;
1135         struct ubi_vid_hdr *avhdr, *dvhdr;
1136         struct ubi_work *ubi_wrk;
1137         struct rb_node *tmp_rb;
1138         int ret, i, j, free_peb_count, used_peb_count, vol_count;
1139         int scrub_peb_count, erase_peb_count;
1140         unsigned long *seen_pebs;
1141 
1142         fm_raw = ubi->fm_buf;
1143         memset(ubi->fm_buf, 0, ubi->fm_size);
1144 
1145         avbuf = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1146         if (!avbuf) {
1147                 ret = -ENOMEM;
1148                 goto out;
1149         }
1150 
1151         dvbuf = new_fm_vbuf(ubi, UBI_FM_DATA_VOLUME_ID);
1152         if (!dvbuf) {
1153                 ret = -ENOMEM;
1154                 goto out_free_avbuf;
1155         }
1156 
1157         avhdr = ubi_get_vid_hdr(avbuf);
1158         dvhdr = ubi_get_vid_hdr(dvbuf);
1159 
1160         seen_pebs = init_seen(ubi);
1161         if (IS_ERR(seen_pebs)) {
1162                 ret = PTR_ERR(seen_pebs);
1163                 goto out_free_dvbuf;
1164         }
1165 
1166         spin_lock(&ubi->volumes_lock);
1167         spin_lock(&ubi->wl_lock);
1168 
1169         fmsb = (struct ubi_fm_sb *)fm_raw;
1170         fm_pos += sizeof(*fmsb);
1171         ubi_assert(fm_pos <= ubi->fm_size);
1172 
1173         fmh = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
1174         fm_pos += sizeof(*fmh);
1175         ubi_assert(fm_pos <= ubi->fm_size);
1176 
1177         fmsb->magic = cpu_to_be32(UBI_FM_SB_MAGIC);
1178         fmsb->version = UBI_FM_FMT_VERSION;
1179         fmsb->used_blocks = cpu_to_be32(new_fm->used_blocks);
1180         /* the max sqnum will be filled in while *reading* the fastmap */
1181         fmsb->sqnum = 0;
1182 
1183         fmh->magic = cpu_to_be32(UBI_FM_HDR_MAGIC);
1184         free_peb_count = 0;
1185         used_peb_count = 0;
1186         scrub_peb_count = 0;
1187         erase_peb_count = 0;
1188         vol_count = 0;
1189 
1190         fmpl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1191         fm_pos += sizeof(*fmpl);
1192         fmpl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1193         fmpl->size = cpu_to_be16(ubi->fm_pool.size);
1194         fmpl->max_size = cpu_to_be16(ubi->fm_pool.max_size);
1195 
1196         for (i = 0; i < ubi->fm_pool.size; i++) {
1197                 fmpl->pebs[i] = cpu_to_be32(ubi->fm_pool.pebs[i]);
1198                 set_seen(ubi, ubi->fm_pool.pebs[i], seen_pebs);
1199         }
1200 
1201         fmpl_wl = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
1202         fm_pos += sizeof(*fmpl_wl);
1203         fmpl_wl->magic = cpu_to_be32(UBI_FM_POOL_MAGIC);
1204         fmpl_wl->size = cpu_to_be16(ubi->fm_wl_pool.size);
1205         fmpl_wl->max_size = cpu_to_be16(ubi->fm_wl_pool.max_size);
1206 
1207         for (i = 0; i < ubi->fm_wl_pool.size; i++) {
1208                 fmpl_wl->pebs[i] = cpu_to_be32(ubi->fm_wl_pool.pebs[i]);
1209                 set_seen(ubi, ubi->fm_wl_pool.pebs[i], seen_pebs);
1210         }
1211 
1212         ubi_for_each_free_peb(ubi, wl_e, tmp_rb) {
1213                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1214 
1215                 fec->pnum = cpu_to_be32(wl_e->pnum);
1216                 set_seen(ubi, wl_e->pnum, seen_pebs);
1217                 fec->ec = cpu_to_be32(wl_e->ec);
1218 
1219                 free_peb_count++;
1220                 fm_pos += sizeof(*fec);
1221                 ubi_assert(fm_pos <= ubi->fm_size);
1222         }
1223         fmh->free_peb_count = cpu_to_be32(free_peb_count);
1224 
1225         ubi_for_each_used_peb(ubi, wl_e, tmp_rb) {
1226                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1227 
1228                 fec->pnum = cpu_to_be32(wl_e->pnum);
1229                 set_seen(ubi, wl_e->pnum, seen_pebs);
1230                 fec->ec = cpu_to_be32(wl_e->ec);
1231 
1232                 used_peb_count++;
1233                 fm_pos += sizeof(*fec);
1234                 ubi_assert(fm_pos <= ubi->fm_size);
1235         }
1236 
1237         ubi_for_each_protected_peb(ubi, i, wl_e) {
1238                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1239 
1240                 fec->pnum = cpu_to_be32(wl_e->pnum);
1241                 set_seen(ubi, wl_e->pnum, seen_pebs);
1242                 fec->ec = cpu_to_be32(wl_e->ec);
1243 
1244                 used_peb_count++;
1245                 fm_pos += sizeof(*fec);
1246                 ubi_assert(fm_pos <= ubi->fm_size);
1247         }
1248         fmh->used_peb_count = cpu_to_be32(used_peb_count);
1249 
1250         ubi_for_each_scrub_peb(ubi, wl_e, tmp_rb) {
1251                 fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1252 
1253                 fec->pnum = cpu_to_be32(wl_e->pnum);
1254                 set_seen(ubi, wl_e->pnum, seen_pebs);
1255                 fec->ec = cpu_to_be32(wl_e->ec);
1256 
1257                 scrub_peb_count++;
1258                 fm_pos += sizeof(*fec);
1259                 ubi_assert(fm_pos <= ubi->fm_size);
1260         }
1261         fmh->scrub_peb_count = cpu_to_be32(scrub_peb_count);
1262 
1263 
1264         list_for_each_entry(ubi_wrk, &ubi->works, list) {
1265                 if (ubi_is_erase_work(ubi_wrk)) {
1266                         wl_e = ubi_wrk->e;
1267                         ubi_assert(wl_e);
1268 
1269                         fec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
1270 
1271                         fec->pnum = cpu_to_be32(wl_e->pnum);
1272                         set_seen(ubi, wl_e->pnum, seen_pebs);
1273                         fec->ec = cpu_to_be32(wl_e->ec);
1274 
1275                         erase_peb_count++;
1276                         fm_pos += sizeof(*fec);
1277                         ubi_assert(fm_pos <= ubi->fm_size);
1278                 }
1279         }
1280         fmh->erase_peb_count = cpu_to_be32(erase_peb_count);
1281 
1282         for (i = 0; i < UBI_MAX_VOLUMES + UBI_INT_VOL_COUNT; i++) {
1283                 vol = ubi->volumes[i];
1284 
1285                 if (!vol)
1286                         continue;
1287 
1288                 vol_count++;
1289 
1290                 fvh = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
1291                 fm_pos += sizeof(*fvh);
1292                 ubi_assert(fm_pos <= ubi->fm_size);
1293 
1294                 fvh->magic = cpu_to_be32(UBI_FM_VHDR_MAGIC);
1295                 fvh->vol_id = cpu_to_be32(vol->vol_id);
1296                 fvh->vol_type = vol->vol_type;
1297                 fvh->used_ebs = cpu_to_be32(vol->used_ebs);
1298                 fvh->data_pad = cpu_to_be32(vol->data_pad);
1299                 fvh->last_eb_bytes = cpu_to_be32(vol->last_eb_bytes);
1300 
1301                 ubi_assert(vol->vol_type == UBI_DYNAMIC_VOLUME ||
1302                         vol->vol_type == UBI_STATIC_VOLUME);
1303 
1304                 feba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
1305                 fm_pos += sizeof(*feba) + (sizeof(__be32) * vol->reserved_pebs);
1306                 ubi_assert(fm_pos <= ubi->fm_size);
1307 
1308                 for (j = 0; j < vol->reserved_pebs; j++) {
1309                         struct ubi_eba_leb_desc ldesc;
1310 
1311                         ubi_eba_get_ldesc(vol, j, &ldesc);
1312                         feba->pnum[j] = cpu_to_be32(ldesc.pnum);
1313                 }
1314 
1315                 feba->reserved_pebs = cpu_to_be32(j);
1316                 feba->magic = cpu_to_be32(UBI_FM_EBA_MAGIC);
1317         }
1318         fmh->vol_count = cpu_to_be32(vol_count);
1319         fmh->bad_peb_count = cpu_to_be32(ubi->bad_peb_count);
1320 
1321         avhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1322         avhdr->lnum = 0;
1323 
1324         spin_unlock(&ubi->wl_lock);
1325         spin_unlock(&ubi->volumes_lock);
1326 
1327         dbg_bld("writing fastmap SB to PEB %i", new_fm->e[0]->pnum);
1328         ret = ubi_io_write_vid_hdr(ubi, new_fm->e[0]->pnum, avbuf);
1329         if (ret) {
1330                 ubi_err(ubi, "unable to write vid_hdr to fastmap SB!");
1331                 goto out_free_seen;
1332         }
1333 
1334         for (i = 0; i < new_fm->used_blocks; i++) {
1335                 fmsb->block_loc[i] = cpu_to_be32(new_fm->e[i]->pnum);
1336                 set_seen(ubi, new_fm->e[i]->pnum, seen_pebs);
1337                 fmsb->block_ec[i] = cpu_to_be32(new_fm->e[i]->ec);
1338         }
1339 
1340         fmsb->data_crc = 0;
1341         fmsb->data_crc = cpu_to_be32(crc32(UBI_CRC32_INIT, fm_raw,
1342                                            ubi->fm_size));
1343 
1344         for (i = 1; i < new_fm->used_blocks; i++) {
1345                 dvhdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1346                 dvhdr->lnum = cpu_to_be32(i);
1347                 dbg_bld("writing fastmap data to PEB %i sqnum %llu",
1348                         new_fm->e[i]->pnum, be64_to_cpu(dvhdr->sqnum));
1349                 ret = ubi_io_write_vid_hdr(ubi, new_fm->e[i]->pnum, dvbuf);
1350                 if (ret) {
1351                         ubi_err(ubi, "unable to write vid_hdr to PEB %i!",
1352                                 new_fm->e[i]->pnum);
1353                         goto out_free_seen;
1354                 }
1355         }
1356 
1357         for (i = 0; i < new_fm->used_blocks; i++) {
1358                 ret = ubi_io_write_data(ubi, fm_raw + (i * ubi->leb_size),
1359                                         new_fm->e[i]->pnum, 0, ubi->leb_size);
1360                 if (ret) {
1361                         ubi_err(ubi, "unable to write fastmap to PEB %i!",
1362                                 new_fm->e[i]->pnum);
1363                         goto out_free_seen;
1364                 }
1365         }
1366 
1367         ubi_assert(new_fm);
1368         ubi->fm = new_fm;
1369 
1370         ret = self_check_seen(ubi, seen_pebs);
1371         dbg_bld("fastmap written!");
1372 
1373 out_free_seen:
1374         free_seen(seen_pebs);
1375 out_free_dvbuf:
1376         ubi_free_vid_buf(dvbuf);
1377 out_free_avbuf:
1378         ubi_free_vid_buf(avbuf);
1379 
1380 out:
1381         return ret;
1382 }
1383 
1384 /**
1385  * erase_block - Manually erase a PEB.
1386  * @ubi: UBI device object
1387  * @pnum: PEB to be erased
1388  *
1389  * Returns the new EC value on success, < 0 indicates an internal error.
1390  */
1391 static int erase_block(struct ubi_device *ubi, int pnum)
1392 {
1393         int ret;
1394         struct ubi_ec_hdr *ec_hdr;
1395         long long ec;
1396 
1397         ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
1398         if (!ec_hdr)
1399                 return -ENOMEM;
1400 
1401         ret = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
1402         if (ret < 0)
1403                 goto out;
1404         else if (ret && ret != UBI_IO_BITFLIPS) {
1405                 ret = -EINVAL;
1406                 goto out;
1407         }
1408 
1409         ret = ubi_io_sync_erase(ubi, pnum, 0);
1410         if (ret < 0)
1411                 goto out;
1412 
1413         ec = be64_to_cpu(ec_hdr->ec);
1414         ec += ret;
1415         if (ec > UBI_MAX_ERASECOUNTER) {
1416                 ret = -EINVAL;
1417                 goto out;
1418         }
1419 
1420         ec_hdr->ec = cpu_to_be64(ec);
1421         ret = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
1422         if (ret < 0)
1423                 goto out;
1424 
1425         ret = ec;
1426 out:
1427         kfree(ec_hdr);
1428         return ret;
1429 }
1430 
1431 /**
1432  * invalidate_fastmap - destroys a fastmap.
1433  * @ubi: UBI device object
1434  *
1435  * This function ensures that upon next UBI attach a full scan
1436  * is issued. We need this if UBI is about to write a new fastmap
1437  * but is unable to do so. In this case we have two options:
1438  * a) Make sure that the current fastmap will not be usued upon
1439  * attach time and contine or b) fall back to RO mode to have the
1440  * current fastmap in a valid state.
1441  * Returns 0 on success, < 0 indicates an internal error.
1442  */
1443 static int invalidate_fastmap(struct ubi_device *ubi)
1444 {
1445         int ret;
1446         struct ubi_fastmap_layout *fm;
1447         struct ubi_wl_entry *e;
1448         struct ubi_vid_io_buf *vb = NULL;
1449         struct ubi_vid_hdr *vh;
1450 
1451         if (!ubi->fm)
1452                 return 0;
1453 
1454         ubi->fm = NULL;
1455 
1456         ret = -ENOMEM;
1457         fm = kzalloc(sizeof(*fm), GFP_KERNEL);
1458         if (!fm)
1459                 goto out;
1460 
1461         vb = new_fm_vbuf(ubi, UBI_FM_SB_VOLUME_ID);
1462         if (!vb)
1463                 goto out_free_fm;
1464 
1465         vh = ubi_get_vid_hdr(vb);
1466 
1467         ret = -ENOSPC;
1468         e = ubi_wl_get_fm_peb(ubi, 1);
1469         if (!e)
1470                 goto out_free_fm;
1471 
1472         /*
1473          * Create fake fastmap such that UBI will fall back
1474          * to scanning mode.
1475          */
1476         vh->sqnum = cpu_to_be64(ubi_next_sqnum(ubi));
1477         ret = ubi_io_write_vid_hdr(ubi, e->pnum, vb);
1478         if (ret < 0) {
1479                 ubi_wl_put_fm_peb(ubi, e, 0, 0);
1480                 goto out_free_fm;
1481         }
1482 
1483         fm->used_blocks = 1;
1484         fm->e[0] = e;
1485 
1486         ubi->fm = fm;
1487 
1488 out:
1489         ubi_free_vid_buf(vb);
1490         return ret;
1491 
1492 out_free_fm:
1493         kfree(fm);
1494         goto out;
1495 }
1496 
1497 /**
1498  * return_fm_pebs - returns all PEBs used by a fastmap back to the
1499  * WL sub-system.
1500  * @ubi: UBI device object
1501  * @fm: fastmap layout object
1502  */
1503 static void return_fm_pebs(struct ubi_device *ubi,
1504                            struct ubi_fastmap_layout *fm)
1505 {
1506         int i;
1507 
1508         if (!fm)
1509                 return;
1510 
1511         for (i = 0; i < fm->used_blocks; i++) {
1512                 if (fm->e[i]) {
1513                         ubi_wl_put_fm_peb(ubi, fm->e[i], i,
1514                                           fm->to_be_tortured[i]);
1515                         fm->e[i] = NULL;
1516                 }
1517         }
1518 }
1519 
1520 /**
1521  * ubi_update_fastmap - will be called by UBI if a volume changes or
1522  * a fastmap pool becomes full.
1523  * @ubi: UBI device object
1524  *
1525  * Returns 0 on success, < 0 indicates an internal error.
1526  */
1527 int ubi_update_fastmap(struct ubi_device *ubi)
1528 {
1529         int ret, i, j;
1530         struct ubi_fastmap_layout *new_fm, *old_fm;
1531         struct ubi_wl_entry *tmp_e;
1532 
1533         down_write(&ubi->fm_protect);
1534         down_write(&ubi->work_sem);
1535         down_write(&ubi->fm_eba_sem);
1536 
1537         ubi_refill_pools(ubi);
1538 
1539         if (ubi->ro_mode || ubi->fm_disabled) {
1540                 up_write(&ubi->fm_eba_sem);
1541                 up_write(&ubi->work_sem);
1542                 up_write(&ubi->fm_protect);
1543                 return 0;
1544         }
1545 
1546         ret = ubi_ensure_anchor_pebs(ubi);
1547         if (ret) {
1548                 up_write(&ubi->fm_eba_sem);
1549                 up_write(&ubi->work_sem);
1550                 up_write(&ubi->fm_protect);
1551                 return ret;
1552         }
1553 
1554         new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL);
1555         if (!new_fm) {
1556                 up_write(&ubi->fm_eba_sem);
1557                 up_write(&ubi->work_sem);
1558                 up_write(&ubi->fm_protect);
1559                 return -ENOMEM;
1560         }
1561 
1562         new_fm->used_blocks = ubi->fm_size / ubi->leb_size;
1563         old_fm = ubi->fm;
1564         ubi->fm = NULL;
1565 
1566         if (new_fm->used_blocks > UBI_FM_MAX_BLOCKS) {
1567                 ubi_err(ubi, "fastmap too large");
1568                 ret = -ENOSPC;
1569                 goto err;
1570         }
1571 
1572         for (i = 1; i < new_fm->used_blocks; i++) {
1573                 spin_lock(&ubi->wl_lock);
1574                 tmp_e = ubi_wl_get_fm_peb(ubi, 0);
1575                 spin_unlock(&ubi->wl_lock);
1576 
1577                 if (!tmp_e) {
1578                         if (old_fm && old_fm->e[i]) {
1579                                 ret = erase_block(ubi, old_fm->e[i]->pnum);
1580                                 if (ret < 0) {
1581                                         ubi_err(ubi, "could not erase old fastmap PEB");
1582 
1583                                         for (j = 1; j < i; j++) {
1584                                                 ubi_wl_put_fm_peb(ubi, new_fm->e[j],
1585                                                                   j, 0);
1586                                                 new_fm->e[j] = NULL;
1587                                         }
1588                                         goto err;
1589                                 }
1590                                 new_fm->e[i] = old_fm->e[i];
1591                                 old_fm->e[i] = NULL;
1592                         } else {
1593                                 ubi_err(ubi, "could not get any free erase block");
1594 
1595                                 for (j = 1; j < i; j++) {
1596                                         ubi_wl_put_fm_peb(ubi, new_fm->e[j], j, 0);
1597                                         new_fm->e[j] = NULL;
1598                                 }
1599 
1600                                 ret = -ENOSPC;
1601                                 goto err;
1602                         }
1603                 } else {
1604                         new_fm->e[i] = tmp_e;
1605 
1606                         if (old_fm && old_fm->e[i]) {
1607                                 ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1608                                                   old_fm->to_be_tortured[i]);
1609                                 old_fm->e[i] = NULL;
1610                         }
1611                 }
1612         }
1613 
1614         /* Old fastmap is larger than the new one */
1615         if (old_fm && new_fm->used_blocks < old_fm->used_blocks) {
1616                 for (i = new_fm->used_blocks; i < old_fm->used_blocks; i++) {
1617                         ubi_wl_put_fm_peb(ubi, old_fm->e[i], i,
1618                                           old_fm->to_be_tortured[i]);
1619                         old_fm->e[i] = NULL;
1620                 }
1621         }
1622 
1623         spin_lock(&ubi->wl_lock);
1624         tmp_e = ubi_wl_get_fm_peb(ubi, 1);
1625         spin_unlock(&ubi->wl_lock);
1626 
1627         if (old_fm) {
1628                 /* no fresh anchor PEB was found, reuse the old one */
1629                 if (!tmp_e) {
1630                         ret = erase_block(ubi, old_fm->e[0]->pnum);
1631                         if (ret < 0) {
1632                                 ubi_err(ubi, "could not erase old anchor PEB");
1633 
1634                                 for (i = 1; i < new_fm->used_blocks; i++) {
1635                                         ubi_wl_put_fm_peb(ubi, new_fm->e[i],
1636                                                           i, 0);
1637                                         new_fm->e[i] = NULL;
1638                                 }
1639                                 goto err;
1640                         }
1641                         new_fm->e[0] = old_fm->e[0];
1642                         new_fm->e[0]->ec = ret;
1643                         old_fm->e[0] = NULL;
1644                 } else {
1645                         /* we've got a new anchor PEB, return the old one */
1646                         ubi_wl_put_fm_peb(ubi, old_fm->e[0], 0,
1647                                           old_fm->to_be_tortured[0]);
1648                         new_fm->e[0] = tmp_e;
1649                         old_fm->e[0] = NULL;
1650                 }
1651         } else {
1652                 if (!tmp_e) {
1653                         ubi_err(ubi, "could not find any anchor PEB");
1654 
1655                         for (i = 1; i < new_fm->used_blocks; i++) {
1656                                 ubi_wl_put_fm_peb(ubi, new_fm->e[i], i, 0);
1657                                 new_fm->e[i] = NULL;
1658                         }
1659 
1660                         ret = -ENOSPC;
1661                         goto err;
1662                 }
1663                 new_fm->e[0] = tmp_e;
1664         }
1665 
1666         ret = ubi_write_fastmap(ubi, new_fm);
1667 
1668         if (ret)
1669                 goto err;
1670 
1671 out_unlock:
1672         up_write(&ubi->fm_eba_sem);
1673         up_write(&ubi->work_sem);
1674         up_write(&ubi->fm_protect);
1675         kfree(old_fm);
1676         return ret;
1677 
1678 err:
1679         ubi_warn(ubi, "Unable to write new fastmap, err=%i", ret);
1680 
1681         ret = invalidate_fastmap(ubi);
1682         if (ret < 0) {
1683                 ubi_err(ubi, "Unable to invalidate current fastmap!");
1684                 ubi_ro_mode(ubi);
1685         } else {
1686                 return_fm_pebs(ubi, old_fm);
1687                 return_fm_pebs(ubi, new_fm);
1688                 ret = 0;
1689         }
1690 
1691         kfree(new_fm);
1692         goto out_unlock;
1693 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/mtd/ubi/fastmap.c

DEFINITIONS
