fs/ubifs/lprops.c

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  *
  19  * Authors: Adrian Hunter
  20  *          Artem Bityutskiy (Битюцкий Артём)
  21  */
  22
  23 /*
  24  * This file implements the functions that access LEB properties and their
  25  * categories. LEBs are categorized based on the needs of UBIFS, and the
  26  * categories are stored as either heaps or lists to provide a fast way of
  27  * finding a LEB in a particular category. For example, UBIFS may need to find
  28  * an empty LEB for the journal, or a very dirty LEB for garbage collection.
  29  */
  30
  31 #include "ubifs.h"
  32
  33 /**
  34  * get_heap_comp_val - get the LEB properties value for heap comparisons.
  35  * @lprops: LEB properties
  36  * @cat: LEB category
  37  */
  38 static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat)
  39 {
  40         switch (cat) {
  41         case LPROPS_FREE:
  42                 return lprops->free;
  43         case LPROPS_DIRTY_IDX:
  44                 return lprops->free + lprops->dirty;
  45         default:
  46                 return lprops->dirty;
  47         }
  48 }
  49
  50 /**
  51  * move_up_lpt_heap - move a new heap entry up as far as possible.
  52  * @c: UBIFS file-system description object
  53  * @heap: LEB category heap
  54  * @lprops: LEB properties to move
  55  * @cat: LEB category
  56  *
  57  * New entries to a heap are added at the bottom and then moved up until the
  58  * parent's value is greater.  In the case of LPT's category heaps, the value
  59  * is either the amount of free space or the amount of dirty space, depending
  60  * on the category.
  61  */
  62 static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
  63                              struct ubifs_lprops *lprops, int cat)
  64 {
  65         int val1, val2, hpos;
  66
  67         hpos = lprops->hpos;
  68         if (!hpos)
  69                 return; /* Already top of the heap */
  70         val1 = get_heap_comp_val(lprops, cat);
  71         /* Compare to parent and, if greater, move up the heap */
  72         do {
  73                 int ppos = (hpos - 1) / 2;
  74
  75                 val2 = get_heap_comp_val(heap->arr[ppos], cat);
  76                 if (val2 >= val1)
  77                         return;
  78                 /* Greater than parent so move up */
  79                 heap->arr[ppos]->hpos = hpos;
  80                 heap->arr[hpos] = heap->arr[ppos];
  81                 heap->arr[ppos] = lprops;
  82                 lprops->hpos = ppos;
  83                 hpos = ppos;
  84         } while (hpos);
  85 }
  86
  87 /**
  88  * adjust_lpt_heap - move a changed heap entry up or down the heap.
  89  * @c: UBIFS file-system description object
  90  * @heap: LEB category heap
  91  * @lprops: LEB properties to move
  92  * @hpos: heap position of @lprops
  93  * @cat: LEB category
  94  *
  95  * Changed entries in a heap are moved up or down until the parent's value is
  96  * greater.  In the case of LPT's category heaps, the value is either the amount
  97  * of free space or the amount of dirty space, depending on the category.
  98  */
  99 static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
 100                             struct ubifs_lprops *lprops, int hpos, int cat)
 101 {
 102         int val1, val2, val3, cpos;
 103
 104         val1 = get_heap_comp_val(lprops, cat);
 105         /* Compare to parent and, if greater than parent, move up the heap */
 106         if (hpos) {
 107                 int ppos = (hpos - 1) / 2;
 108
 109                 val2 = get_heap_comp_val(heap->arr[ppos], cat);
 110                 if (val1 > val2) {
 111                         /* Greater than parent so move up */
 112                         while (1) {
 113                                 heap->arr[ppos]->hpos = hpos;
 114                                 heap->arr[hpos] = heap->arr[ppos];
 115                                 heap->arr[ppos] = lprops;
 116                                 lprops->hpos = ppos;
 117                                 hpos = ppos;
 118                                 if (!hpos)
 119                                         return;
 120                                 ppos = (hpos - 1) / 2;
 121                                 val2 = get_heap_comp_val(heap->arr[ppos], cat);
 122                                 if (val1 <= val2)
 123                                         return;
 124                                 /* Still greater than parent so keep going */
 125                         }
 126                 }
 127         }
 128
 129         /* Not greater than parent, so compare to children */
 130         while (1) {
 131                 /* Compare to left child */
 132                 cpos = hpos * 2 + 1;
 133                 if (cpos >= heap->cnt)
 134                         return;
 135                 val2 = get_heap_comp_val(heap->arr[cpos], cat);
 136                 if (val1 < val2) {
 137                         /* Less than left child, so promote biggest child */
 138                         if (cpos + 1 < heap->cnt) {
 139                                 val3 = get_heap_comp_val(heap->arr[cpos + 1],
 140                                                          cat);
 141                                 if (val3 > val2)
 142                                         cpos += 1; /* Right child is bigger */
 143                         }
 144                         heap->arr[cpos]->hpos = hpos;
 145                         heap->arr[hpos] = heap->arr[cpos];
 146                         heap->arr[cpos] = lprops;
 147                         lprops->hpos = cpos;
 148                         hpos = cpos;
 149                         continue;
 150                 }
 151                 /* Compare to right child */
 152                 cpos += 1;
 153                 if (cpos >= heap->cnt)
 154                         return;
 155                 val3 = get_heap_comp_val(heap->arr[cpos], cat);
 156                 if (val1 < val3) {
 157                         /* Less than right child, so promote right child */
 158                         heap->arr[cpos]->hpos = hpos;
 159                         heap->arr[hpos] = heap->arr[cpos];
 160                         heap->arr[cpos] = lprops;
 161                         lprops->hpos = cpos;
 162                         hpos = cpos;
 163                         continue;
 164                 }
 165                 return;
 166         }
 167 }
 168
 169 /**
 170  * add_to_lpt_heap - add LEB properties to a LEB category heap.
 171  * @c: UBIFS file-system description object
 172  * @lprops: LEB properties to add
 173  * @cat: LEB category
 174  *
 175  * This function returns %1 if @lprops is added to the heap for LEB category
 176  * @cat, otherwise %0 is returned because the heap is full.
 177  */
 178 static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops,
 179                            int cat)
 180 {
 181         struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
 182
 183         if (heap->cnt >= heap->max_cnt) {
 184                 const int b = LPT_HEAP_SZ / 2 - 1;
 185                 int cpos, val1, val2;
 186
 187                 /* Compare to some other LEB on the bottom of heap */
 188                 /* Pick a position kind of randomly */
 189                 cpos = (((size_t)lprops >> 4) & b) + b;
 190                 ubifs_assert(cpos >= b);
 191                 ubifs_assert(cpos < LPT_HEAP_SZ);
 192                 ubifs_assert(cpos < heap->cnt);
 193
 194                 val1 = get_heap_comp_val(lprops, cat);
 195                 val2 = get_heap_comp_val(heap->arr[cpos], cat);
 196                 if (val1 > val2) {
 197                         struct ubifs_lprops *lp;
 198
 199                         lp = heap->arr[cpos];
 200                         lp->flags &= ~LPROPS_CAT_MASK;
 201                         lp->flags |= LPROPS_UNCAT;
 202                         list_add(&lp->list, &c->uncat_list);
 203                         lprops->hpos = cpos;
 204                         heap->arr[cpos] = lprops;
 205                         move_up_lpt_heap(c, heap, lprops, cat);
 206                         dbg_check_heap(c, heap, cat, lprops->hpos);
 207                         return 1; /* Added to heap */
 208                 }
 209                 dbg_check_heap(c, heap, cat, -1);
 210                 return 0; /* Not added to heap */
 211         } else {
 212                 lprops->hpos = heap->cnt++;
 213                 heap->arr[lprops->hpos] = lprops;
 214                 move_up_lpt_heap(c, heap, lprops, cat);
 215                 dbg_check_heap(c, heap, cat, lprops->hpos);
 216                 return 1; /* Added to heap */
 217         }
 218 }
 219
 220 /**
 221  * remove_from_lpt_heap - remove LEB properties from a LEB category heap.
 222  * @c: UBIFS file-system description object
 223  * @lprops: LEB properties to remove
 224  * @cat: LEB category
 225  */
 226 static void remove_from_lpt_heap(struct ubifs_info *c,
 227                                  struct ubifs_lprops *lprops, int cat)
 228 {
 229         struct ubifs_lpt_heap *heap;
 230         int hpos = lprops->hpos;
 231
 232         heap = &c->lpt_heap[cat - 1];
 233         ubifs_assert(hpos >= 0 && hpos < heap->cnt);
 234         ubifs_assert(heap->arr[hpos] == lprops);
 235         heap->cnt -= 1;
 236         if (hpos < heap->cnt) {
 237                 heap->arr[hpos] = heap->arr[heap->cnt];
 238                 heap->arr[hpos]->hpos = hpos;
 239                 adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat);
 240         }
 241         dbg_check_heap(c, heap, cat, -1);
 242 }
 243
 244 /**
 245  * lpt_heap_replace - replace lprops in a category heap.
 246  * @c: UBIFS file-system description object
 247  * @old_lprops: LEB properties to replace
 248  * @new_lprops: LEB properties with which to replace
 249  * @cat: LEB category
 250  *
 251  * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 252  * and the lprops that the pnode contains.  When that happens, references in
 253  * the category heaps to those lprops must be updated to point to the new
 254  * lprops.  This function does that.
 255  */
 256 static void lpt_heap_replace(struct ubifs_info *c,
 257                              struct ubifs_lprops *old_lprops,
 258                              struct ubifs_lprops *new_lprops, int cat)
 259 {
 260         struct ubifs_lpt_heap *heap;
 261         int hpos = new_lprops->hpos;
 262
 263         heap = &c->lpt_heap[cat - 1];
 264         heap->arr[hpos] = new_lprops;
 265 }
 266
 267 /**
 268  * ubifs_add_to_cat - add LEB properties to a category list or heap.
 269  * @c: UBIFS file-system description object
 270  * @lprops: LEB properties to add
 271  * @cat: LEB category to which to add
 272  *
 273  * LEB properties are categorized to enable fast find operations.
 274  */
 275 void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
 276                       int cat)
 277 {
 278         switch (cat) {
 279         case LPROPS_DIRTY:
 280         case LPROPS_DIRTY_IDX:
 281         case LPROPS_FREE:
 282                 if (add_to_lpt_heap(c, lprops, cat))
 283                         break;
 284                 /* No more room on heap so make it un-categorized */
 285                 cat = LPROPS_UNCAT;
 286                 /* Fall through */
 287         case LPROPS_UNCAT:
 288                 list_add(&lprops->list, &c->uncat_list);
 289                 break;
 290         case LPROPS_EMPTY:
 291                 list_add(&lprops->list, &c->empty_list);
 292                 break;
 293         case LPROPS_FREEABLE:
 294                 list_add(&lprops->list, &c->freeable_list);
 295                 c->freeable_cnt += 1;
 296                 break;
 297         case LPROPS_FRDI_IDX:
 298                 list_add(&lprops->list, &c->frdi_idx_list);
 299                 break;
 300         default:
 301                 ubifs_assert(0);
 302         }
 303
 304         lprops->flags &= ~LPROPS_CAT_MASK;
 305         lprops->flags |= cat;
 306         c->in_a_category_cnt += 1;
 307         ubifs_assert(c->in_a_category_cnt <= c->main_lebs);
 308 }
 309
 310 /**
 311  * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
 312  * @c: UBIFS file-system description object
 313  * @lprops: LEB properties to remove
 314  * @cat: LEB category from which to remove
 315  *
 316  * LEB properties are categorized to enable fast find operations.
 317  */
 318 static void ubifs_remove_from_cat(struct ubifs_info *c,
 319                                   struct ubifs_lprops *lprops, int cat)
 320 {
 321         switch (cat) {
 322         case LPROPS_DIRTY:
 323         case LPROPS_DIRTY_IDX:
 324         case LPROPS_FREE:
 325                 remove_from_lpt_heap(c, lprops, cat);
 326                 break;
 327         case LPROPS_FREEABLE:
 328                 c->freeable_cnt -= 1;
 329                 ubifs_assert(c->freeable_cnt >= 0);
 330                 /* Fall through */
 331         case LPROPS_UNCAT:
 332         case LPROPS_EMPTY:
 333         case LPROPS_FRDI_IDX:
 334                 ubifs_assert(!list_empty(&lprops->list));
 335                 list_del(&lprops->list);
 336                 break;
 337         default:
 338                 ubifs_assert(0);
 339         }
 340
 341         c->in_a_category_cnt -= 1;
 342         ubifs_assert(c->in_a_category_cnt >= 0);
 343 }
 344
 345 /**
 346  * ubifs_replace_cat - replace lprops in a category list or heap.
 347  * @c: UBIFS file-system description object
 348  * @old_lprops: LEB properties to replace
 349  * @new_lprops: LEB properties with which to replace
 350  *
 351  * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 352  * and the lprops that the pnode contains. When that happens, references in
 353  * category lists and heaps must be replaced. This function does that.
 354  */
 355 void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
 356                        struct ubifs_lprops *new_lprops)
 357 {
 358         int cat;
 359
 360         cat = new_lprops->flags & LPROPS_CAT_MASK;
 361         switch (cat) {
 362         case LPROPS_DIRTY:
 363         case LPROPS_DIRTY_IDX:
 364         case LPROPS_FREE:
 365                 lpt_heap_replace(c, old_lprops, new_lprops, cat);
 366                 break;
 367         case LPROPS_UNCAT:
 368         case LPROPS_EMPTY:
 369         case LPROPS_FREEABLE:
 370         case LPROPS_FRDI_IDX:
 371                 list_replace(&old_lprops->list, &new_lprops->list);
 372                 break;
 373         default:
 374                 ubifs_assert(0);
 375         }
 376 }
 377
 378 /**
 379  * ubifs_ensure_cat - ensure LEB properties are categorized.
 380  * @c: UBIFS file-system description object
 381  * @lprops: LEB properties
 382  *
 383  * A LEB may have fallen off of the bottom of a heap, and ended up as
 384  * un-categorized even though it has enough space for us now. If that is the
 385  * case this function will put the LEB back onto a heap.
 386  */
 387 void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
 388 {
 389         int cat = lprops->flags & LPROPS_CAT_MASK;
 390
 391         if (cat != LPROPS_UNCAT)
 392                 return;
 393         cat = ubifs_categorize_lprops(c, lprops);
 394         if (cat == LPROPS_UNCAT)
 395                 return;
 396         ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
 397         ubifs_add_to_cat(c, lprops, cat);
 398 }
 399
 400 /**
 401  * ubifs_categorize_lprops - categorize LEB properties.
 402  * @c: UBIFS file-system description object
 403  * @lprops: LEB properties to categorize
 404  *
 405  * LEB properties are categorized to enable fast find operations. This function
 406  * returns the LEB category to which the LEB properties belong. Note however
 407  * that if the LEB category is stored as a heap and the heap is full, the
 408  * LEB properties may have their category changed to %LPROPS_UNCAT.
 409  */
 410 int ubifs_categorize_lprops(const struct ubifs_info *c,
 411                             const struct ubifs_lprops *lprops)
 412 {
 413         if (lprops->flags & LPROPS_TAKEN)
 414                 return LPROPS_UNCAT;
 415
 416         if (lprops->free == c->leb_size) {
 417                 ubifs_assert(!(lprops->flags & LPROPS_INDEX));
 418                 return LPROPS_EMPTY;
 419         }
 420
 421         if (lprops->free + lprops->dirty == c->leb_size) {
 422                 if (lprops->flags & LPROPS_INDEX)
 423                         return LPROPS_FRDI_IDX;
 424                 else
 425                         return LPROPS_FREEABLE;
 426         }
 427
 428         if (lprops->flags & LPROPS_INDEX) {
 429                 if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
 430                         return LPROPS_DIRTY_IDX;
 431         } else {
 432                 if (lprops->dirty >= c->dead_wm &&
 433                     lprops->dirty > lprops->free)
 434                         return LPROPS_DIRTY;
 435                 if (lprops->free > 0)
 436                         return LPROPS_FREE;
 437         }
 438
 439         return LPROPS_UNCAT;
 440 }
 441
 442 /**
 443  * change_category - change LEB properties category.
 444  * @c: UBIFS file-system description object
 445  * @lprops: LEB properties to re-categorize
 446  *
 447  * LEB properties are categorized to enable fast find operations. When the LEB
 448  * properties change they must be re-categorized.
 449  */
 450 static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
 451 {
 452         int old_cat = lprops->flags & LPROPS_CAT_MASK;
 453         int new_cat = ubifs_categorize_lprops(c, lprops);
 454
 455         if (old_cat == new_cat) {
 456                 struct ubifs_lpt_heap *heap;
 457
 458                 /* lprops on a heap now must be moved up or down */
 459                 if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
 460                         return; /* Not on a heap */
 461                 heap = &c->lpt_heap[new_cat - 1];
 462                 adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
 463         } else {
 464                 ubifs_remove_from_cat(c, lprops, old_cat);
 465                 ubifs_add_to_cat(c, lprops, new_cat);
 466         }
 467 }
 468
 469 /**
 470  * ubifs_calc_dark - calculate LEB dark space size.
 471  * @c: the UBIFS file-system description object
 472  * @spc: amount of free and dirty space in the LEB
 473  *
 474  * This function calculates and returns amount of dark space in an LEB which
 475  * has @spc bytes of free and dirty space.
 476  *
 477  * UBIFS is trying to account the space which might not be usable, and this
 478  * space is called "dark space". For example, if an LEB has only %512 free
 479  * bytes, it is dark space, because it cannot fit a large data node.
 480  */
 481 int ubifs_calc_dark(const struct ubifs_info *c, int spc)
 482 {
 483         ubifs_assert(!(spc & 7));
 484
 485         if (spc < c->dark_wm)
 486                 return spc;
 487
 488         /*
 489          * If we have slightly more space then the dark space watermark, we can
 490          * anyway safely assume it we'll be able to write a node of the
 491          * smallest size there.
 492          */
 493         if (spc - c->dark_wm < MIN_WRITE_SZ)
 494                 return spc - MIN_WRITE_SZ;
 495
 496         return c->dark_wm;
 497 }
 498
 499 /**
 500  * is_lprops_dirty - determine if LEB properties are dirty.
 501  * @c: the UBIFS file-system description object
 502  * @lprops: LEB properties to test
 503  */
 504 static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
 505 {
 506         struct ubifs_pnode *pnode;
 507         int pos;
 508
 509         pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
 510         pnode = (struct ubifs_pnode *)container_of(lprops - pos,
 511                                                    struct ubifs_pnode,
 512                                                    lprops[0]);
 513         return !test_bit(COW_CNODE, &pnode->flags) &&
 514                test_bit(DIRTY_CNODE, &pnode->flags);
 515 }
 516
 517 /**
 518  * ubifs_change_lp - change LEB properties.
 519  * @c: the UBIFS file-system description object
 520  * @lp: LEB properties to change
 521  * @free: new free space amount
 522  * @dirty: new dirty space amount
 523  * @flags: new flags
 524  * @idx_gc_cnt: change to the count of @idx_gc list
 525  *
 526  * This function changes LEB properties (@free, @dirty or @flag). However, the
 527  * property which has the %LPROPS_NC value is not changed. Returns a pointer to
 528  * the updated LEB properties on success and a negative error code on failure.
 529  *
 530  * Note, the LEB properties may have had to be copied (due to COW) and
 531  * consequently the pointer returned may not be the same as the pointer
 532  * passed.
 533  */
 534 const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
 535                                            const struct ubifs_lprops *lp,
 536                                            int free, int dirty, int flags,
 537                                            int idx_gc_cnt)
 538 {
 539         /*
 540          * This is the only function that is allowed to change lprops, so we
 541          * discard the "const" qualifier.
 542          */
 543         struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;
 544
 545         dbg_lp("LEB %d, free %d, dirty %d, flags %d",
 546                lprops->lnum, free, dirty, flags);
 547
 548         ubifs_assert(mutex_is_locked(&c->lp_mutex));
 549         ubifs_assert(c->lst.empty_lebs >= 0 &&
 550                      c->lst.empty_lebs <= c->main_lebs);
 551         ubifs_assert(c->freeable_cnt >= 0);
 552         ubifs_assert(c->freeable_cnt <= c->main_lebs);
 553         ubifs_assert(c->lst.taken_empty_lebs >= 0);
 554         ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
 555         ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
 556         ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
 557         ubifs_assert(!(c->lst.total_used & 7));
 558         ubifs_assert(free == LPROPS_NC || free >= 0);
 559         ubifs_assert(dirty == LPROPS_NC || dirty >= 0);
 560
 561         if (!is_lprops_dirty(c, lprops)) {
 562                 lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
 563                 if (IS_ERR(lprops))
 564                         return lprops;
 565         } else
 566                 ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));
 567
 568         ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));
 569
 570         spin_lock(&c->space_lock);
 571         if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
 572                 c->lst.taken_empty_lebs -= 1;
 573
 574         if (!(lprops->flags & LPROPS_INDEX)) {
 575                 int old_spc;
 576
 577                 old_spc = lprops->free + lprops->dirty;
 578                 if (old_spc < c->dead_wm)
 579                         c->lst.total_dead -= old_spc;
 580                 else
 581                         c->lst.total_dark -= ubifs_calc_dark(c, old_spc);
 582
 583                 c->lst.total_used -= c->leb_size - old_spc;
 584         }
 585
 586         if (free != LPROPS_NC) {
 587                 free = ALIGN(free, 8);
 588                 c->lst.total_free += free - lprops->free;
 589
 590                 /* Increase or decrease empty LEBs counter if needed */
 591                 if (free == c->leb_size) {
 592                         if (lprops->free != c->leb_size)
 593                                 c->lst.empty_lebs += 1;
 594                 } else if (lprops->free == c->leb_size)
 595                         c->lst.empty_lebs -= 1;
 596                 lprops->free = free;
 597         }
 598
 599         if (dirty != LPROPS_NC) {
 600                 dirty = ALIGN(dirty, 8);
 601                 c->lst.total_dirty += dirty - lprops->dirty;
 602                 lprops->dirty = dirty;
 603         }
 604
 605         if (flags != LPROPS_NC) {
 606                 /* Take care about indexing LEBs counter if needed */
 607                 if ((lprops->flags & LPROPS_INDEX)) {
 608                         if (!(flags & LPROPS_INDEX))
 609                                 c->lst.idx_lebs -= 1;
 610                 } else if (flags & LPROPS_INDEX)
 611                         c->lst.idx_lebs += 1;
 612                 lprops->flags = flags;
 613         }
 614
 615         if (!(lprops->flags & LPROPS_INDEX)) {
 616                 int new_spc;
 617
 618                 new_spc = lprops->free + lprops->dirty;
 619                 if (new_spc < c->dead_wm)
 620                         c->lst.total_dead += new_spc;
 621                 else
 622                         c->lst.total_dark += ubifs_calc_dark(c, new_spc);
 623
 624                 c->lst.total_used += c->leb_size - new_spc;
 625         }
 626
 627         if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
 628                 c->lst.taken_empty_lebs += 1;
 629
 630         change_category(c, lprops);
 631         c->idx_gc_cnt += idx_gc_cnt;
 632         spin_unlock(&c->space_lock);
 633         return lprops;
 634 }
 635
 636 /**
 637  * ubifs_get_lp_stats - get lprops statistics.
 638  * @c: UBIFS file-system description object
 639  * @lst: return statistics
 640  */
 641 void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
 642 {
 643         spin_lock(&c->space_lock);
 644         memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats));
 645         spin_unlock(&c->space_lock);
 646 }
 647
 648 /**
 649  * ubifs_change_one_lp - change LEB properties.
 650  * @c: the UBIFS file-system description object
 651  * @lnum: LEB to change properties for
 652  * @free: amount of free space
 653  * @dirty: amount of dirty space
 654  * @flags_set: flags to set
 655  * @flags_clean: flags to clean
 656  * @idx_gc_cnt: change to the count of idx_gc list
 657  *
 658  * This function changes properties of LEB @lnum. It is a helper wrapper over
 659  * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
 660  * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
 661  * a negative error code in case of failure.
 662  */
 663 int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
 664                         int flags_set, int flags_clean, int idx_gc_cnt)
 665 {
 666         int err = 0, flags;
 667         const struct ubifs_lprops *lp;
 668
 669         ubifs_get_lprops(c);
 670
 671         lp = ubifs_lpt_lookup_dirty(c, lnum);
 672         if (IS_ERR(lp)) {
 673                 err = PTR_ERR(lp);
 674                 goto out;
 675         }
 676
 677         flags = (lp->flags | flags_set) & ~flags_clean;
 678         lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
 679         if (IS_ERR(lp))
 680                 err = PTR_ERR(lp);
 681
 682 out:
 683         ubifs_release_lprops(c);
 684         if (err)
 685                 ubifs_err(c, "cannot change properties of LEB %d, error %d",
 686                           lnum, err);
 687         return err;
 688 }
 689
 690 /**
 691  * ubifs_update_one_lp - update LEB properties.
 692  * @c: the UBIFS file-system description object
 693  * @lnum: LEB to change properties for
 694  * @free: amount of free space
 695  * @dirty: amount of dirty space to add
 696  * @flags_set: flags to set
 697  * @flags_clean: flags to clean
 698  *
 699  * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
 700  * current dirty space, not substitutes it.
 701  */
 702 int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
 703                         int flags_set, int flags_clean)
 704 {
 705         int err = 0, flags;
 706         const struct ubifs_lprops *lp;
 707
 708         ubifs_get_lprops(c);
 709
 710         lp = ubifs_lpt_lookup_dirty(c, lnum);
 711         if (IS_ERR(lp)) {
 712                 err = PTR_ERR(lp);
 713                 goto out;
 714         }
 715
 716         flags = (lp->flags | flags_set) & ~flags_clean;
 717         lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
 718         if (IS_ERR(lp))
 719                 err = PTR_ERR(lp);
 720
 721 out:
 722         ubifs_release_lprops(c);
 723         if (err)
 724                 ubifs_err(c, "cannot update properties of LEB %d, error %d",
 725                           lnum, err);
 726         return err;
 727 }
 728
 729 /**
 730  * ubifs_read_one_lp - read LEB properties.
 731  * @c: the UBIFS file-system description object
 732  * @lnum: LEB to read properties for
 733  * @lp: where to store read properties
 734  *
 735  * This helper function reads properties of a LEB @lnum and stores them in @lp.
 736  * Returns zero in case of success and a negative error code in case of
 737  * failure.
 738  */
 739 int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
 740 {
 741         int err = 0;
 742         const struct ubifs_lprops *lpp;
 743
 744         ubifs_get_lprops(c);
 745
 746         lpp = ubifs_lpt_lookup(c, lnum);
 747         if (IS_ERR(lpp)) {
 748                 err = PTR_ERR(lpp);
 749                 ubifs_err(c, "cannot read properties of LEB %d, error %d",
 750                           lnum, err);
 751                 goto out;
 752         }
 753
 754         memcpy(lp, lpp, sizeof(struct ubifs_lprops));
 755
 756 out:
 757         ubifs_release_lprops(c);
 758         return err;
 759 }
 760
 761 /**
 762  * ubifs_fast_find_free - try to find a LEB with free space quickly.
 763  * @c: the UBIFS file-system description object
 764  *
 765  * This function returns LEB properties for a LEB with free space or %NULL if
 766  * the function is unable to find a LEB quickly.
 767  */
 768 const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
 769 {
 770         struct ubifs_lprops *lprops;
 771         struct ubifs_lpt_heap *heap;
 772
 773         ubifs_assert(mutex_is_locked(&c->lp_mutex));
 774
 775         heap = &c->lpt_heap[LPROPS_FREE - 1];
 776         if (heap->cnt == 0)
 777                 return NULL;
 778
 779         lprops = heap->arr[0];
 780         ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
 781         ubifs_assert(!(lprops->flags & LPROPS_INDEX));
 782         return lprops;
 783 }
 784
 785 /**
 786  * ubifs_fast_find_empty - try to find an empty LEB quickly.
 787  * @c: the UBIFS file-system description object
 788  *
 789  * This function returns LEB properties for an empty LEB or %NULL if the
 790  * function is unable to find an empty LEB quickly.
 791  */
 792 const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
 793 {
 794         struct ubifs_lprops *lprops;
 795
 796         ubifs_assert(mutex_is_locked(&c->lp_mutex));
 797
 798         if (list_empty(&c->empty_list))
 799                 return NULL;
 800
 801         lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
 802         ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
 803         ubifs_assert(!(lprops->flags & LPROPS_INDEX));
 804         ubifs_assert(lprops->free == c->leb_size);
 805         return lprops;
 806 }
 807
 808 /**
 809  * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
 810  * @c: the UBIFS file-system description object
 811  *
 812  * This function returns LEB properties for a freeable LEB or %NULL if the
 813  * function is unable to find a freeable LEB quickly.
 814  */
 815 const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
 816 {
 817         struct ubifs_lprops *lprops;
 818
 819         ubifs_assert(mutex_is_locked(&c->lp_mutex));
 820
 821         if (list_empty(&c->freeable_list))
 822                 return NULL;
 823
 824         lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
 825         ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
 826         ubifs_assert(!(lprops->flags & LPROPS_INDEX));
 827         ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
 828         ubifs_assert(c->freeable_cnt > 0);
 829         return lprops;
 830 }
 831
 832 /**
 833  * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
 834  * @c: the UBIFS file-system description object
 835  *
 836  * This function returns LEB properties for a freeable index LEB or %NULL if the
 837  * function is unable to find a freeable index LEB quickly.
 838  */
 839 const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
 840 {
 841         struct ubifs_lprops *lprops;
 842
 843         ubifs_assert(mutex_is_locked(&c->lp_mutex));
 844
 845         if (list_empty(&c->frdi_idx_list))
 846                 return NULL;
 847
 848         lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
 849         ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
 850         ubifs_assert((lprops->flags & LPROPS_INDEX));
 851         ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
 852         return lprops;
 853 }
 854
 855 /*
 856  * Everything below is related to debugging.
 857  */
 858
 859 /**
 860  * dbg_check_cats - check category heaps and lists.
 861  * @c: UBIFS file-system description object
 862  *
 863  * This function returns %0 on success and a negative error code on failure.
 864  */
 865 int dbg_check_cats(struct ubifs_info *c)
 866 {
 867         struct ubifs_lprops *lprops;
 868         struct list_head *pos;
 869         int i, cat;
 870
 871         if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
 872                 return 0;
 873
 874         list_for_each_entry(lprops, &c->empty_list, list) {
 875                 if (lprops->free != c->leb_size) {
 876                         ubifs_err(c, "non-empty LEB %d on empty list (free %d dirty %d flags %d)",
 877                                   lprops->lnum, lprops->free, lprops->dirty,
 878                                   lprops->flags);
 879                         return -EINVAL;
 880                 }
 881                 if (lprops->flags & LPROPS_TAKEN) {
 882                         ubifs_err(c, "taken LEB %d on empty list (free %d dirty %d flags %d)",
 883                                   lprops->lnum, lprops->free, lprops->dirty,
 884                                   lprops->flags);
 885                         return -EINVAL;
 886                 }
 887         }
 888
 889         i = 0;
 890         list_for_each_entry(lprops, &c->freeable_list, list) {
 891                 if (lprops->free + lprops->dirty != c->leb_size) {
 892                         ubifs_err(c, "non-freeable LEB %d on freeable list (free %d dirty %d flags %d)",
 893                                   lprops->lnum, lprops->free, lprops->dirty,
 894                                   lprops->flags);
 895                         return -EINVAL;
 896                 }
 897                 if (lprops->flags & LPROPS_TAKEN) {
 898                         ubifs_err(c, "taken LEB %d on freeable list (free %d dirty %d flags %d)",
 899                                   lprops->lnum, lprops->free, lprops->dirty,
 900                                   lprops->flags);
 901                         return -EINVAL;
 902                 }
 903                 i += 1;
 904         }
 905         if (i != c->freeable_cnt) {
 906                 ubifs_err(c, "freeable list count %d expected %d", i,
 907                           c->freeable_cnt);
 908                 return -EINVAL;
 909         }
 910
 911         i = 0;
 912         list_for_each(pos, &c->idx_gc)
 913                 i += 1;
 914         if (i != c->idx_gc_cnt) {
 915                 ubifs_err(c, "idx_gc list count %d expected %d", i,
 916                           c->idx_gc_cnt);
 917                 return -EINVAL;
 918         }
 919
 920         list_for_each_entry(lprops, &c->frdi_idx_list, list) {
 921                 if (lprops->free + lprops->dirty != c->leb_size) {
 922                         ubifs_err(c, "non-freeable LEB %d on frdi_idx list (free %d dirty %d flags %d)",
 923                                   lprops->lnum, lprops->free, lprops->dirty,
 924                                   lprops->flags);
 925                         return -EINVAL;
 926                 }
 927                 if (lprops->flags & LPROPS_TAKEN) {
 928                         ubifs_err(c, "taken LEB %d on frdi_idx list (free %d dirty %d flags %d)",
 929                                   lprops->lnum, lprops->free, lprops->dirty,
 930                                   lprops->flags);
 931                         return -EINVAL;
 932                 }
 933                 if (!(lprops->flags & LPROPS_INDEX)) {
 934                         ubifs_err(c, "non-index LEB %d on frdi_idx list (free %d dirty %d flags %d)",
 935                                   lprops->lnum, lprops->free, lprops->dirty,
 936                                   lprops->flags);
 937                         return -EINVAL;
 938                 }
 939         }
 940
 941         for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) {
 942                 struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
 943
 944                 for (i = 0; i < heap->cnt; i++) {
 945                         lprops = heap->arr[i];
 946                         if (!lprops) {
 947                                 ubifs_err(c, "null ptr in LPT heap cat %d", cat);
 948                                 return -EINVAL;
 949                         }
 950                         if (lprops->hpos != i) {
 951                                 ubifs_err(c, "bad ptr in LPT heap cat %d", cat);
 952                                 return -EINVAL;
 953                         }
 954                         if (lprops->flags & LPROPS_TAKEN) {
 955                                 ubifs_err(c, "taken LEB in LPT heap cat %d", cat);
 956                                 return -EINVAL;
 957                         }
 958                 }
 959         }
 960
 961         return 0;
 962 }
 963
 964 void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
 965                     int add_pos)
 966 {
 967         int i = 0, j, err = 0;
 968
 969         if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
 970                 return;
 971
 972         for (i = 0; i < heap->cnt; i++) {
 973                 struct ubifs_lprops *lprops = heap->arr[i];
 974                 struct ubifs_lprops *lp;
 975
 976                 if (i != add_pos)
 977                         if ((lprops->flags & LPROPS_CAT_MASK) != cat) {
 978                                 err = 1;
 979                                 goto out;
 980                         }
 981                 if (lprops->hpos != i) {
 982                         err = 2;
 983                         goto out;
 984                 }
 985                 lp = ubifs_lpt_lookup(c, lprops->lnum);
 986                 if (IS_ERR(lp)) {
 987                         err = 3;
 988                         goto out;
 989                 }
 990                 if (lprops != lp) {
 991                         ubifs_err(c, "lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
 992                                   (size_t)lprops, (size_t)lp, lprops->lnum,
 993                                   lp->lnum);
 994                         err = 4;
 995                         goto out;
 996                 }
 997                 for (j = 0; j < i; j++) {
 998                         lp = heap->arr[j];
 999                         if (lp == lprops) {
1000                                 err = 5;
1001                                 goto out;
1002                         }
1003                         if (lp->lnum == lprops->lnum) {
1004                                 err = 6;
1005                                 goto out;
1006                         }
1007                 }
1008         }
1009 out:
1010         if (err) {
1011                 ubifs_err(c, "failed cat %d hpos %d err %d", cat, i, err);
1012                 dump_stack();
1013                 ubifs_dump_heap(c, heap, cat);
1014         }
1015 }
1016
1017 /**
1018  * scan_check_cb - scan callback.
1019  * @c: the UBIFS file-system description object
1020  * @lp: LEB properties to scan
1021  * @in_tree: whether the LEB properties are in main memory
1022  * @lst: lprops statistics to update
1023  *
1024  * This function returns a code that indicates whether the scan should continue
1025  * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
1026  * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
1027  * (%LPT_SCAN_STOP).
1028  */
1029 static int scan_check_cb(struct ubifs_info *c,
1030                          const struct ubifs_lprops *lp, int in_tree,
1031                          struct ubifs_lp_stats *lst)
1032 {
1033         struct ubifs_scan_leb *sleb;
1034         struct ubifs_scan_node *snod;
1035         int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty, ret;
1036         void *buf = NULL;
1037
1038         cat = lp->flags & LPROPS_CAT_MASK;
1039         if (cat != LPROPS_UNCAT) {
1040                 cat = ubifs_categorize_lprops(c, lp);
1041                 if (cat != (lp->flags & LPROPS_CAT_MASK)) {
1042                         ubifs_err(c, "bad LEB category %d expected %d",
1043                                   (lp->flags & LPROPS_CAT_MASK), cat);
1044                         return -EINVAL;
1045                 }
1046         }
1047
1048         /* Check lp is on its category list (if it has one) */
1049         if (in_tree) {
1050                 struct list_head *list = NULL;
1051
1052                 switch (cat) {
1053                 case LPROPS_EMPTY:
1054                         list = &c->empty_list;
1055                         break;
1056                 case LPROPS_FREEABLE:
1057                         list = &c->freeable_list;
1058                         break;
1059                 case LPROPS_FRDI_IDX:
1060                         list = &c->frdi_idx_list;
1061                         break;
1062                 case LPROPS_UNCAT:
1063                         list = &c->uncat_list;
1064                         break;
1065                 }
1066                 if (list) {
1067                         struct ubifs_lprops *lprops;
1068                         int found = 0;
1069
1070                         list_for_each_entry(lprops, list, list) {
1071                                 if (lprops == lp) {
1072                                         found = 1;
1073                                         break;
1074                                 }
1075                         }
1076                         if (!found) {
1077                                 ubifs_err(c, "bad LPT list (category %d)", cat);
1078                                 return -EINVAL;
1079                         }
1080                 }
1081         }
1082
1083         /* Check lp is on its category heap (if it has one) */
1084         if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) {
1085                 struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
1086
1087                 if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) ||
1088                     lp != heap->arr[lp->hpos]) {
1089                         ubifs_err(c, "bad LPT heap (category %d)", cat);
1090                         return -EINVAL;
1091                 }
1092         }
1093
1094         buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1095         if (!buf)
1096                 return -ENOMEM;
1097
1098         /*
1099          * After an unclean unmount, empty and freeable LEBs
1100          * may contain garbage - do not scan them.
1101          */
1102         if (lp->free == c->leb_size) {
1103                 lst->empty_lebs += 1;
1104                 lst->total_free += c->leb_size;
1105                 lst->total_dark += ubifs_calc_dark(c, c->leb_size);
1106                 return LPT_SCAN_CONTINUE;
1107         }
1108         if (lp->free + lp->dirty == c->leb_size &&
1109             !(lp->flags & LPROPS_INDEX)) {
1110                 lst->total_free  += lp->free;
1111                 lst->total_dirty += lp->dirty;
1112                 lst->total_dark  +=  ubifs_calc_dark(c, c->leb_size);
1113                 return LPT_SCAN_CONTINUE;
1114         }
1115
1116         sleb = ubifs_scan(c, lnum, 0, buf, 0);
1117         if (IS_ERR(sleb)) {
1118                 ret = PTR_ERR(sleb);
1119                 if (ret == -EUCLEAN) {
1120                         ubifs_dump_lprops(c);
1121                         ubifs_dump_budg(c, &c->bi);
1122                 }
1123                 goto out;
1124         }
1125
1126         is_idx = -1;
1127         list_for_each_entry(snod, &sleb->nodes, list) {
1128                 int found, level = 0;
1129
1130                 cond_resched();
1131
1132                 if (is_idx == -1)
1133                         is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0;
1134
1135                 if (is_idx && snod->type != UBIFS_IDX_NODE) {
1136                         ubifs_err(c, "indexing node in data LEB %d:%d",
1137                                   lnum, snod->offs);
1138                         goto out_destroy;
1139                 }
1140
1141                 if (snod->type == UBIFS_IDX_NODE) {
1142                         struct ubifs_idx_node *idx = snod->node;
1143
1144                         key_read(c, ubifs_idx_key(c, idx), &snod->key);
1145                         level = le16_to_cpu(idx->level);
1146                 }
1147
1148                 found = ubifs_tnc_has_node(c, &snod->key, level, lnum,
1149                                            snod->offs, is_idx);
1150                 if (found) {
1151                         if (found < 0)
1152                                 goto out_destroy;
1153                         used += ALIGN(snod->len, 8);
1154                 }
1155         }
1156
1157         free = c->leb_size - sleb->endpt;
1158         dirty = sleb->endpt - used;
1159
1160         if (free > c->leb_size || free < 0 || dirty > c->leb_size ||
1161             dirty < 0) {
1162                 ubifs_err(c, "bad calculated accounting for LEB %d: free %d, dirty %d",
1163                           lnum, free, dirty);
1164                 goto out_destroy;
1165         }
1166
1167         if (lp->free + lp->dirty == c->leb_size &&
1168             free + dirty == c->leb_size)
1169                 if ((is_idx && !(lp->flags & LPROPS_INDEX)) ||
1170                     (!is_idx && free == c->leb_size) ||
1171                     lp->free == c->leb_size) {
1172                         /*
1173                          * Empty or freeable LEBs could contain index
1174                          * nodes from an uncompleted commit due to an
1175                          * unclean unmount. Or they could be empty for
1176                          * the same reason. Or it may simply not have been
1177                          * unmapped.
1178                          */
1179                         free = lp->free;
1180                         dirty = lp->dirty;
1181                         is_idx = 0;
1182                     }
1183
1184         if (is_idx && lp->free + lp->dirty == free + dirty &&
1185             lnum != c->ihead_lnum) {
1186                 /*
1187                  * After an unclean unmount, an index LEB could have a different
1188                  * amount of free space than the value recorded by lprops. That
1189                  * is because the in-the-gaps method may use free space or
1190                  * create free space (as a side-effect of using ubi_leb_change
1191                  * and not writing the whole LEB). The incorrect free space
1192                  * value is not a problem because the index is only ever
1193                  * allocated empty LEBs, so there will never be an attempt to
1194                  * write to the free space at the end of an index LEB - except
1195                  * by the in-the-gaps method for which it is not a problem.
1196                  */
1197                 free = lp->free;
1198                 dirty = lp->dirty;
1199         }
1200
1201         if (lp->free != free || lp->dirty != dirty)
1202                 goto out_print;
1203
1204         if (is_idx && !(lp->flags & LPROPS_INDEX)) {
1205                 if (free == c->leb_size)
1206                         /* Free but not unmapped LEB, it's fine */
1207                         is_idx = 0;
1208                 else {
1209                         ubifs_err(c, "indexing node without indexing flag");
1210                         goto out_print;
1211                 }
1212         }
1213
1214         if (!is_idx && (lp->flags & LPROPS_INDEX)) {
1215                 ubifs_err(c, "data node with indexing flag");
1216                 goto out_print;
1217         }
1218
1219         if (free == c->leb_size)
1220                 lst->empty_lebs += 1;
1221
1222         if (is_idx)
1223                 lst->idx_lebs += 1;
1224
1225         if (!(lp->flags & LPROPS_INDEX))
1226                 lst->total_used += c->leb_size - free - dirty;
1227         lst->total_free += free;
1228         lst->total_dirty += dirty;
1229
1230         if (!(lp->flags & LPROPS_INDEX)) {
1231                 int spc = free + dirty;
1232
1233                 if (spc < c->dead_wm)
1234                         lst->total_dead += spc;
1235                 else
1236                         lst->total_dark += ubifs_calc_dark(c, spc);
1237         }
1238
1239         ubifs_scan_destroy(sleb);
1240         vfree(buf);
1241         return LPT_SCAN_CONTINUE;
1242
1243 out_print:
1244         ubifs_err(c, "bad accounting of LEB %d: free %d, dirty %d flags %#x, should be free %d, dirty %d",
1245                   lnum, lp->free, lp->dirty, lp->flags, free, dirty);
1246         ubifs_dump_leb(c, lnum);
1247 out_destroy:
1248         ubifs_scan_destroy(sleb);
1249         ret = -EINVAL;
1250 out:
1251         vfree(buf);
1252         return ret;
1253 }
1254
1255 /**
1256  * dbg_check_lprops - check all LEB properties.
1257  * @c: UBIFS file-system description object
1258  *
1259  * This function checks all LEB properties and makes sure they are all correct.
1260  * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
1261  * and other negative error codes in case of other errors. This function is
1262  * called while the file system is locked (because of commit start), so no
1263  * additional locking is required. Note that locking the LPT mutex would cause
1264  * a circular lock dependency with the TNC mutex.
1265  */
1266 int dbg_check_lprops(struct ubifs_info *c)
1267 {
1268         int i, err;
1269         struct ubifs_lp_stats lst;
1270
1271         if (!dbg_is_chk_lprops(c))
1272                 return 0;
1273
1274         /*
1275          * As we are going to scan the media, the write buffers have to be
1276          * synchronized.
1277          */
1278         for (i = 0; i < c->jhead_cnt; i++) {
1279                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1280                 if (err)
1281                         return err;
1282         }
1283
1284         memset(&lst, 0, sizeof(struct ubifs_lp_stats));
1285         err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
1286                                     (ubifs_lpt_scan_callback)scan_check_cb,
1287                                     &lst);
1288         if (err && err != -ENOSPC)
1289                 goto out;
1290
1291         if (lst.empty_lebs != c->lst.empty_lebs ||
1292             lst.idx_lebs != c->lst.idx_lebs ||
1293             lst.total_free != c->lst.total_free ||
1294             lst.total_dirty != c->lst.total_dirty ||
1295             lst.total_used != c->lst.total_used) {
1296                 ubifs_err(c, "bad overall accounting");
1297                 ubifs_err(c, "calculated: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
1298                           lst.empty_lebs, lst.idx_lebs, lst.total_free,
1299                           lst.total_dirty, lst.total_used);
1300                 ubifs_err(c, "read from lprops: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
1301                           c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
1302                           c->lst.total_dirty, c->lst.total_used);
1303                 err = -EINVAL;
1304                 goto out;
1305         }
1306
1307         if (lst.total_dead != c->lst.total_dead ||
1308             lst.total_dark != c->lst.total_dark) {
1309                 ubifs_err(c, "bad dead/dark space accounting");
1310                 ubifs_err(c, "calculated: total_dead %lld, total_dark %lld",
1311                           lst.total_dead, lst.total_dark);
1312                 ubifs_err(c, "read from lprops: total_dead %lld, total_dark %lld",
1313                           c->lst.total_dead, c->lst.total_dark);
1314                 err = -EINVAL;
1315                 goto out;
1316         }
1317
1318         err = dbg_check_cats(c);
1319 out:
1320         return err;
1321 }