linux/fs/ubifs/lprops.c
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   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 */
  38static 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 */
  62static 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 */
  99static 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 */
 178static 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 */
 226static 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 */
 256static 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 */
 275void 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 */
 318static 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 */
 355void 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 */
 387void 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 */
 410int 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 */
 450static 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 */
 481int 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 */
 504static 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 */
 534const 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 * @st: return statistics
 640 */
 641void 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 */
 663int 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
 682out:
 683        ubifs_release_lprops(c);
 684        if (err)
 685                ubifs_err("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 */
 702int 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
 721out:
 722        ubifs_release_lprops(c);
 723        if (err)
 724                ubifs_err("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 */
 739int 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("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
 756out:
 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 */
 768const 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 */
 792const 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 */
 815const 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 */
 839const 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 */
 865int 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("non-empty LEB %d on empty list "
 877                                  "(free %d dirty %d flags %d)", lprops->lnum,
 878                                  lprops->free, lprops->dirty, lprops->flags);
 879                        return -EINVAL;
 880                }
 881                if (lprops->flags & LPROPS_TAKEN) {
 882                        ubifs_err("taken LEB %d on empty list "
 883                                  "(free %d dirty %d flags %d)", lprops->lnum,
 884                                  lprops->free, lprops->dirty, 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("non-freeable LEB %d on freeable list "
 893                                  "(free %d dirty %d flags %d)", lprops->lnum,
 894                                  lprops->free, lprops->dirty, lprops->flags);
 895                        return -EINVAL;
 896                }
 897                if (lprops->flags & LPROPS_TAKEN) {
 898                        ubifs_err("taken LEB %d on freeable list "
 899                                  "(free %d dirty %d flags %d)", lprops->lnum,
 900                                  lprops->free, lprops->dirty, lprops->flags);
 901                        return -EINVAL;
 902                }
 903                i += 1;
 904        }
 905        if (i != c->freeable_cnt) {
 906                ubifs_err("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("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("non-freeable LEB %d on frdi_idx list "
 923                                  "(free %d dirty %d flags %d)", lprops->lnum,
 924                                  lprops->free, lprops->dirty, lprops->flags);
 925                        return -EINVAL;
 926                }
 927                if (lprops->flags & LPROPS_TAKEN) {
 928                        ubifs_err("taken LEB %d on frdi_idx list "
 929                                  "(free %d dirty %d flags %d)", lprops->lnum,
 930                                  lprops->free, lprops->dirty, lprops->flags);
 931                        return -EINVAL;
 932                }
 933                if (!(lprops->flags & LPROPS_INDEX)) {
 934                        ubifs_err("non-index LEB %d on frdi_idx list "
 935                                  "(free %d dirty %d flags %d)", lprops->lnum,
 936                                  lprops->free, lprops->dirty, 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("null ptr in LPT heap cat %d", cat);
 948                                return -EINVAL;
 949                        }
 950                        if (lprops->hpos != i) {
 951                                ubifs_err("bad ptr in LPT heap cat %d", cat);
 952                                return -EINVAL;
 953                        }
 954                        if (lprops->flags & LPROPS_TAKEN) {
 955                                ubifs_err("taken LEB in LPT heap cat %d", cat);
 956                                return -EINVAL;
 957                        }
 958                }
 959        }
 960
 961        return 0;
 962}
 963
 964void 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                        dbg_msg("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        }
1009out:
1010        if (err) {
1011                dbg_msg("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 */
1029static 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("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("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("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("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("bad calculated accounting for LEB %d: "
1163                          "free %d, dirty %d", 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("indexing node without indexing "
1210                                  "flag");
1211                        goto out_print;
1212                }
1213        }
1214
1215        if (!is_idx && (lp->flags & LPROPS_INDEX)) {
1216                ubifs_err("data node with indexing flag");
1217                goto out_print;
1218        }
1219
1220        if (free == c->leb_size)
1221                lst->empty_lebs += 1;
1222
1223        if (is_idx)
1224                lst->idx_lebs += 1;
1225
1226        if (!(lp->flags & LPROPS_INDEX))
1227                lst->total_used += c->leb_size - free - dirty;
1228        lst->total_free += free;
1229        lst->total_dirty += dirty;
1230
1231        if (!(lp->flags & LPROPS_INDEX)) {
1232                int spc = free + dirty;
1233
1234                if (spc < c->dead_wm)
1235                        lst->total_dead += spc;
1236                else
1237                        lst->total_dark += ubifs_calc_dark(c, spc);
1238        }
1239
1240        ubifs_scan_destroy(sleb);
1241        vfree(buf);
1242        return LPT_SCAN_CONTINUE;
1243
1244out_print:
1245        ubifs_err("bad accounting of LEB %d: free %d, dirty %d flags %#x, "
1246                  "should be free %d, dirty %d",
1247                  lnum, lp->free, lp->dirty, lp->flags, free, dirty);
1248        ubifs_dump_leb(c, lnum);
1249out_destroy:
1250        ubifs_scan_destroy(sleb);
1251        ret = -EINVAL;
1252out:
1253        vfree(buf);
1254        return ret;
1255}
1256
1257/**
1258 * dbg_check_lprops - check all LEB properties.
1259 * @c: UBIFS file-system description object
1260 *
1261 * This function checks all LEB properties and makes sure they are all correct.
1262 * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
1263 * and other negative error codes in case of other errors. This function is
1264 * called while the file system is locked (because of commit start), so no
1265 * additional locking is required. Note that locking the LPT mutex would cause
1266 * a circular lock dependency with the TNC mutex.
1267 */
1268int dbg_check_lprops(struct ubifs_info *c)
1269{
1270        int i, err;
1271        struct ubifs_lp_stats lst;
1272
1273        if (!dbg_is_chk_lprops(c))
1274                return 0;
1275
1276        /*
1277         * As we are going to scan the media, the write buffers have to be
1278         * synchronized.
1279         */
1280        for (i = 0; i < c->jhead_cnt; i++) {
1281                err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1282                if (err)
1283                        return err;
1284        }
1285
1286        memset(&lst, 0, sizeof(struct ubifs_lp_stats));
1287        err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
1288                                    (ubifs_lpt_scan_callback)scan_check_cb,
1289                                    &lst);
1290        if (err && err != -ENOSPC)
1291                goto out;
1292
1293        if (lst.empty_lebs != c->lst.empty_lebs ||
1294            lst.idx_lebs != c->lst.idx_lebs ||
1295            lst.total_free != c->lst.total_free ||
1296            lst.total_dirty != c->lst.total_dirty ||
1297            lst.total_used != c->lst.total_used) {
1298                ubifs_err("bad overall accounting");
1299                ubifs_err("calculated: empty_lebs %d, idx_lebs %d, "
1300                          "total_free %lld, total_dirty %lld, total_used %lld",
1301                          lst.empty_lebs, lst.idx_lebs, lst.total_free,
1302                          lst.total_dirty, lst.total_used);
1303                ubifs_err("read from lprops: empty_lebs %d, idx_lebs %d, "
1304                          "total_free %lld, total_dirty %lld, total_used %lld",
1305                          c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
1306                          c->lst.total_dirty, c->lst.total_used);
1307                err = -EINVAL;
1308                goto out;
1309        }
1310
1311        if (lst.total_dead != c->lst.total_dead ||
1312            lst.total_dark != c->lst.total_dark) {
1313                ubifs_err("bad dead/dark space accounting");
1314                ubifs_err("calculated: total_dead %lld, total_dark %lld",
1315                          lst.total_dead, lst.total_dark);
1316                ubifs_err("read from lprops: total_dead %lld, total_dark %lld",
1317                          c->lst.total_dead, c->lst.total_dark);
1318                err = -EINVAL;
1319                goto out;
1320        }
1321
1322        err = dbg_check_cats(c);
1323out:
1324        return err;
1325}
1326
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