linux/fs/ubifs/lpt_commit.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 commit-related functionality of the LEB properties
  25 * subsystem.
  26 */
  27
  28#include <linux/crc16.h>
  29#include <linux/slab.h>
  30#include <linux/random.h>
  31#include "ubifs.h"
  32
  33static int dbg_populate_lsave(struct ubifs_info *c);
  34
  35/**
  36 * first_dirty_cnode - find first dirty cnode.
  37 * @c: UBIFS file-system description object
  38 * @nnode: nnode at which to start
  39 *
  40 * This function returns the first dirty cnode or %NULL if there is not one.
  41 */
  42static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
  43{
  44        ubifs_assert(nnode);
  45        while (1) {
  46                int i, cont = 0;
  47
  48                for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
  49                        struct ubifs_cnode *cnode;
  50
  51                        cnode = nnode->nbranch[i].cnode;
  52                        if (cnode &&
  53                            test_bit(DIRTY_CNODE, &cnode->flags)) {
  54                                if (cnode->level == 0)
  55                                        return cnode;
  56                                nnode = (struct ubifs_nnode *)cnode;
  57                                cont = 1;
  58                                break;
  59                        }
  60                }
  61                if (!cont)
  62                        return (struct ubifs_cnode *)nnode;
  63        }
  64}
  65
  66/**
  67 * next_dirty_cnode - find next dirty cnode.
  68 * @cnode: cnode from which to begin searching
  69 *
  70 * This function returns the next dirty cnode or %NULL if there is not one.
  71 */
  72static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
  73{
  74        struct ubifs_nnode *nnode;
  75        int i;
  76
  77        ubifs_assert(cnode);
  78        nnode = cnode->parent;
  79        if (!nnode)
  80                return NULL;
  81        for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
  82                cnode = nnode->nbranch[i].cnode;
  83                if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
  84                        if (cnode->level == 0)
  85                                return cnode; /* cnode is a pnode */
  86                        /* cnode is a nnode */
  87                        return first_dirty_cnode((struct ubifs_nnode *)cnode);
  88                }
  89        }
  90        return (struct ubifs_cnode *)nnode;
  91}
  92
  93/**
  94 * get_cnodes_to_commit - create list of dirty cnodes to commit.
  95 * @c: UBIFS file-system description object
  96 *
  97 * This function returns the number of cnodes to commit.
  98 */
  99static int get_cnodes_to_commit(struct ubifs_info *c)
 100{
 101        struct ubifs_cnode *cnode, *cnext;
 102        int cnt = 0;
 103
 104        if (!c->nroot)
 105                return 0;
 106
 107        if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
 108                return 0;
 109
 110        c->lpt_cnext = first_dirty_cnode(c->nroot);
 111        cnode = c->lpt_cnext;
 112        if (!cnode)
 113                return 0;
 114        cnt += 1;
 115        while (1) {
 116                ubifs_assert(!test_bit(COW_CNODE, &cnode->flags));
 117                __set_bit(COW_CNODE, &cnode->flags);
 118                cnext = next_dirty_cnode(cnode);
 119                if (!cnext) {
 120                        cnode->cnext = c->lpt_cnext;
 121                        break;
 122                }
 123                cnode->cnext = cnext;
 124                cnode = cnext;
 125                cnt += 1;
 126        }
 127        dbg_cmt("committing %d cnodes", cnt);
 128        dbg_lp("committing %d cnodes", cnt);
 129        ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
 130        return cnt;
 131}
 132
 133/**
 134 * upd_ltab - update LPT LEB properties.
 135 * @c: UBIFS file-system description object
 136 * @lnum: LEB number
 137 * @free: amount of free space
 138 * @dirty: amount of dirty space to add
 139 */
 140static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
 141{
 142        dbg_lp("LEB %d free %d dirty %d to %d +%d",
 143               lnum, c->ltab[lnum - c->lpt_first].free,
 144               c->ltab[lnum - c->lpt_first].dirty, free, dirty);
 145        ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
 146        c->ltab[lnum - c->lpt_first].free = free;
 147        c->ltab[lnum - c->lpt_first].dirty += dirty;
 148}
 149
 150/**
 151 * alloc_lpt_leb - allocate an LPT LEB that is empty.
 152 * @c: UBIFS file-system description object
 153 * @lnum: LEB number is passed and returned here
 154 *
 155 * This function finds the next empty LEB in the ltab starting from @lnum. If a
 156 * an empty LEB is found it is returned in @lnum and the function returns %0.
 157 * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
 158 * never to run out of space.
 159 */
 160static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
 161{
 162        int i, n;
 163
 164        n = *lnum - c->lpt_first + 1;
 165        for (i = n; i < c->lpt_lebs; i++) {
 166                if (c->ltab[i].tgc || c->ltab[i].cmt)
 167                        continue;
 168                if (c->ltab[i].free == c->leb_size) {
 169                        c->ltab[i].cmt = 1;
 170                        *lnum = i + c->lpt_first;
 171                        return 0;
 172                }
 173        }
 174
 175        for (i = 0; i < n; i++) {
 176                if (c->ltab[i].tgc || c->ltab[i].cmt)
 177                        continue;
 178                if (c->ltab[i].free == c->leb_size) {
 179                        c->ltab[i].cmt = 1;
 180                        *lnum = i + c->lpt_first;
 181                        return 0;
 182                }
 183        }
 184        return -ENOSPC;
 185}
 186
 187/**
 188 * layout_cnodes - layout cnodes for commit.
 189 * @c: UBIFS file-system description object
 190 *
 191 * This function returns %0 on success and a negative error code on failure.
 192 */
 193static int layout_cnodes(struct ubifs_info *c)
 194{
 195        int lnum, offs, len, alen, done_lsave, done_ltab, err;
 196        struct ubifs_cnode *cnode;
 197
 198        err = dbg_chk_lpt_sz(c, 0, 0);
 199        if (err)
 200                return err;
 201        cnode = c->lpt_cnext;
 202        if (!cnode)
 203                return 0;
 204        lnum = c->nhead_lnum;
 205        offs = c->nhead_offs;
 206        /* Try to place lsave and ltab nicely */
 207        done_lsave = !c->big_lpt;
 208        done_ltab = 0;
 209        if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
 210                done_lsave = 1;
 211                c->lsave_lnum = lnum;
 212                c->lsave_offs = offs;
 213                offs += c->lsave_sz;
 214                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 215        }
 216
 217        if (offs + c->ltab_sz <= c->leb_size) {
 218                done_ltab = 1;
 219                c->ltab_lnum = lnum;
 220                c->ltab_offs = offs;
 221                offs += c->ltab_sz;
 222                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 223        }
 224
 225        do {
 226                if (cnode->level) {
 227                        len = c->nnode_sz;
 228                        c->dirty_nn_cnt -= 1;
 229                } else {
 230                        len = c->pnode_sz;
 231                        c->dirty_pn_cnt -= 1;
 232                }
 233                while (offs + len > c->leb_size) {
 234                        alen = ALIGN(offs, c->min_io_size);
 235                        upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 236                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 237                        err = alloc_lpt_leb(c, &lnum);
 238                        if (err)
 239                                goto no_space;
 240                        offs = 0;
 241                        ubifs_assert(lnum >= c->lpt_first &&
 242                                     lnum <= c->lpt_last);
 243                        /* Try to place lsave and ltab nicely */
 244                        if (!done_lsave) {
 245                                done_lsave = 1;
 246                                c->lsave_lnum = lnum;
 247                                c->lsave_offs = offs;
 248                                offs += c->lsave_sz;
 249                                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 250                                continue;
 251                        }
 252                        if (!done_ltab) {
 253                                done_ltab = 1;
 254                                c->ltab_lnum = lnum;
 255                                c->ltab_offs = offs;
 256                                offs += c->ltab_sz;
 257                                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 258                                continue;
 259                        }
 260                        break;
 261                }
 262                if (cnode->parent) {
 263                        cnode->parent->nbranch[cnode->iip].lnum = lnum;
 264                        cnode->parent->nbranch[cnode->iip].offs = offs;
 265                } else {
 266                        c->lpt_lnum = lnum;
 267                        c->lpt_offs = offs;
 268                }
 269                offs += len;
 270                dbg_chk_lpt_sz(c, 1, len);
 271                cnode = cnode->cnext;
 272        } while (cnode && cnode != c->lpt_cnext);
 273
 274        /* Make sure to place LPT's save table */
 275        if (!done_lsave) {
 276                if (offs + c->lsave_sz > c->leb_size) {
 277                        alen = ALIGN(offs, c->min_io_size);
 278                        upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 279                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 280                        err = alloc_lpt_leb(c, &lnum);
 281                        if (err)
 282                                goto no_space;
 283                        offs = 0;
 284                        ubifs_assert(lnum >= c->lpt_first &&
 285                                     lnum <= c->lpt_last);
 286                }
 287                done_lsave = 1;
 288                c->lsave_lnum = lnum;
 289                c->lsave_offs = offs;
 290                offs += c->lsave_sz;
 291                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 292        }
 293
 294        /* Make sure to place LPT's own lprops table */
 295        if (!done_ltab) {
 296                if (offs + c->ltab_sz > c->leb_size) {
 297                        alen = ALIGN(offs, c->min_io_size);
 298                        upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 299                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 300                        err = alloc_lpt_leb(c, &lnum);
 301                        if (err)
 302                                goto no_space;
 303                        offs = 0;
 304                        ubifs_assert(lnum >= c->lpt_first &&
 305                                     lnum <= c->lpt_last);
 306                }
 307                done_ltab = 1;
 308                c->ltab_lnum = lnum;
 309                c->ltab_offs = offs;
 310                offs += c->ltab_sz;
 311                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 312        }
 313
 314        alen = ALIGN(offs, c->min_io_size);
 315        upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 316        dbg_chk_lpt_sz(c, 4, alen - offs);
 317        err = dbg_chk_lpt_sz(c, 3, alen);
 318        if (err)
 319                return err;
 320        return 0;
 321
 322no_space:
 323        ubifs_err("LPT out of space at LEB %d:%d needing %d, done_ltab %d, "
 324                  "done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
 325        ubifs_dump_lpt_info(c);
 326        ubifs_dump_lpt_lebs(c);
 327        dump_stack();
 328        return err;
 329}
 330
 331/**
 332 * realloc_lpt_leb - allocate an LPT LEB that is empty.
 333 * @c: UBIFS file-system description object
 334 * @lnum: LEB number is passed and returned here
 335 *
 336 * This function duplicates exactly the results of the function alloc_lpt_leb.
 337 * It is used during end commit to reallocate the same LEB numbers that were
 338 * allocated by alloc_lpt_leb during start commit.
 339 *
 340 * This function finds the next LEB that was allocated by the alloc_lpt_leb
 341 * function starting from @lnum. If a LEB is found it is returned in @lnum and
 342 * the function returns %0. Otherwise the function returns -ENOSPC.
 343 * Note however, that LPT is designed never to run out of space.
 344 */
 345static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
 346{
 347        int i, n;
 348
 349        n = *lnum - c->lpt_first + 1;
 350        for (i = n; i < c->lpt_lebs; i++)
 351                if (c->ltab[i].cmt) {
 352                        c->ltab[i].cmt = 0;
 353                        *lnum = i + c->lpt_first;
 354                        return 0;
 355                }
 356
 357        for (i = 0; i < n; i++)
 358                if (c->ltab[i].cmt) {
 359                        c->ltab[i].cmt = 0;
 360                        *lnum = i + c->lpt_first;
 361                        return 0;
 362                }
 363        return -ENOSPC;
 364}
 365
 366/**
 367 * write_cnodes - write cnodes for commit.
 368 * @c: UBIFS file-system description object
 369 *
 370 * This function returns %0 on success and a negative error code on failure.
 371 */
 372static int write_cnodes(struct ubifs_info *c)
 373{
 374        int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
 375        struct ubifs_cnode *cnode;
 376        void *buf = c->lpt_buf;
 377
 378        cnode = c->lpt_cnext;
 379        if (!cnode)
 380                return 0;
 381        lnum = c->nhead_lnum;
 382        offs = c->nhead_offs;
 383        from = offs;
 384        /* Ensure empty LEB is unmapped */
 385        if (offs == 0) {
 386                err = ubifs_leb_unmap(c, lnum);
 387                if (err)
 388                        return err;
 389        }
 390        /* Try to place lsave and ltab nicely */
 391        done_lsave = !c->big_lpt;
 392        done_ltab = 0;
 393        if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
 394                done_lsave = 1;
 395                ubifs_pack_lsave(c, buf + offs, c->lsave);
 396                offs += c->lsave_sz;
 397                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 398        }
 399
 400        if (offs + c->ltab_sz <= c->leb_size) {
 401                done_ltab = 1;
 402                ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
 403                offs += c->ltab_sz;
 404                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 405        }
 406
 407        /* Loop for each cnode */
 408        do {
 409                if (cnode->level)
 410                        len = c->nnode_sz;
 411                else
 412                        len = c->pnode_sz;
 413                while (offs + len > c->leb_size) {
 414                        wlen = offs - from;
 415                        if (wlen) {
 416                                alen = ALIGN(wlen, c->min_io_size);
 417                                memset(buf + offs, 0xff, alen - wlen);
 418                                err = ubifs_leb_write(c, lnum, buf + from, from,
 419                                                       alen);
 420                                if (err)
 421                                        return err;
 422                        }
 423                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 424                        err = realloc_lpt_leb(c, &lnum);
 425                        if (err)
 426                                goto no_space;
 427                        offs = from = 0;
 428                        ubifs_assert(lnum >= c->lpt_first &&
 429                                     lnum <= c->lpt_last);
 430                        err = ubifs_leb_unmap(c, lnum);
 431                        if (err)
 432                                return err;
 433                        /* Try to place lsave and ltab nicely */
 434                        if (!done_lsave) {
 435                                done_lsave = 1;
 436                                ubifs_pack_lsave(c, buf + offs, c->lsave);
 437                                offs += c->lsave_sz;
 438                                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 439                                continue;
 440                        }
 441                        if (!done_ltab) {
 442                                done_ltab = 1;
 443                                ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
 444                                offs += c->ltab_sz;
 445                                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 446                                continue;
 447                        }
 448                        break;
 449                }
 450                if (cnode->level)
 451                        ubifs_pack_nnode(c, buf + offs,
 452                                         (struct ubifs_nnode *)cnode);
 453                else
 454                        ubifs_pack_pnode(c, buf + offs,
 455                                         (struct ubifs_pnode *)cnode);
 456                /*
 457                 * The reason for the barriers is the same as in case of TNC.
 458                 * See comment in 'write_index()'. 'dirty_cow_nnode()' and
 459                 * 'dirty_cow_pnode()' are the functions for which this is
 460                 * important.
 461                 */
 462                clear_bit(DIRTY_CNODE, &cnode->flags);
 463                smp_mb__before_clear_bit();
 464                clear_bit(COW_CNODE, &cnode->flags);
 465                smp_mb__after_clear_bit();
 466                offs += len;
 467                dbg_chk_lpt_sz(c, 1, len);
 468                cnode = cnode->cnext;
 469        } while (cnode && cnode != c->lpt_cnext);
 470
 471        /* Make sure to place LPT's save table */
 472        if (!done_lsave) {
 473                if (offs + c->lsave_sz > c->leb_size) {
 474                        wlen = offs - from;
 475                        alen = ALIGN(wlen, c->min_io_size);
 476                        memset(buf + offs, 0xff, alen - wlen);
 477                        err = ubifs_leb_write(c, lnum, buf + from, from, alen);
 478                        if (err)
 479                                return err;
 480                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 481                        err = realloc_lpt_leb(c, &lnum);
 482                        if (err)
 483                                goto no_space;
 484                        offs = from = 0;
 485                        ubifs_assert(lnum >= c->lpt_first &&
 486                                     lnum <= c->lpt_last);
 487                        err = ubifs_leb_unmap(c, lnum);
 488                        if (err)
 489                                return err;
 490                }
 491                done_lsave = 1;
 492                ubifs_pack_lsave(c, buf + offs, c->lsave);
 493                offs += c->lsave_sz;
 494                dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 495        }
 496
 497        /* Make sure to place LPT's own lprops table */
 498        if (!done_ltab) {
 499                if (offs + c->ltab_sz > c->leb_size) {
 500                        wlen = offs - from;
 501                        alen = ALIGN(wlen, c->min_io_size);
 502                        memset(buf + offs, 0xff, alen - wlen);
 503                        err = ubifs_leb_write(c, lnum, buf + from, from, alen);
 504                        if (err)
 505                                return err;
 506                        dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 507                        err = realloc_lpt_leb(c, &lnum);
 508                        if (err)
 509                                goto no_space;
 510                        offs = from = 0;
 511                        ubifs_assert(lnum >= c->lpt_first &&
 512                                     lnum <= c->lpt_last);
 513                        err = ubifs_leb_unmap(c, lnum);
 514                        if (err)
 515                                return err;
 516                }
 517                done_ltab = 1;
 518                ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
 519                offs += c->ltab_sz;
 520                dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 521        }
 522
 523        /* Write remaining data in buffer */
 524        wlen = offs - from;
 525        alen = ALIGN(wlen, c->min_io_size);
 526        memset(buf + offs, 0xff, alen - wlen);
 527        err = ubifs_leb_write(c, lnum, buf + from, from, alen);
 528        if (err)
 529                return err;
 530
 531        dbg_chk_lpt_sz(c, 4, alen - wlen);
 532        err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
 533        if (err)
 534                return err;
 535
 536        c->nhead_lnum = lnum;
 537        c->nhead_offs = ALIGN(offs, c->min_io_size);
 538
 539        dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
 540        dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
 541        dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
 542        if (c->big_lpt)
 543                dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
 544
 545        return 0;
 546
 547no_space:
 548        ubifs_err("LPT out of space mismatch at LEB %d:%d needing %d, done_ltab "
 549                  "%d, done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
 550        ubifs_dump_lpt_info(c);
 551        ubifs_dump_lpt_lebs(c);
 552        dump_stack();
 553        return err;
 554}
 555
 556/**
 557 * next_pnode_to_dirty - find next pnode to dirty.
 558 * @c: UBIFS file-system description object
 559 * @pnode: pnode
 560 *
 561 * This function returns the next pnode to dirty or %NULL if there are no more
 562 * pnodes.  Note that pnodes that have never been written (lnum == 0) are
 563 * skipped.
 564 */
 565static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
 566                                               struct ubifs_pnode *pnode)
 567{
 568        struct ubifs_nnode *nnode;
 569        int iip;
 570
 571        /* Try to go right */
 572        nnode = pnode->parent;
 573        for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
 574                if (nnode->nbranch[iip].lnum)
 575                        return ubifs_get_pnode(c, nnode, iip);
 576        }
 577
 578        /* Go up while can't go right */
 579        do {
 580                iip = nnode->iip + 1;
 581                nnode = nnode->parent;
 582                if (!nnode)
 583                        return NULL;
 584                for (; iip < UBIFS_LPT_FANOUT; iip++) {
 585                        if (nnode->nbranch[iip].lnum)
 586                                break;
 587                }
 588        } while (iip >= UBIFS_LPT_FANOUT);
 589
 590        /* Go right */
 591        nnode = ubifs_get_nnode(c, nnode, iip);
 592        if (IS_ERR(nnode))
 593                return (void *)nnode;
 594
 595        /* Go down to level 1 */
 596        while (nnode->level > 1) {
 597                for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
 598                        if (nnode->nbranch[iip].lnum)
 599                                break;
 600                }
 601                if (iip >= UBIFS_LPT_FANOUT) {
 602                        /*
 603                         * Should not happen, but we need to keep going
 604                         * if it does.
 605                         */
 606                        iip = 0;
 607                }
 608                nnode = ubifs_get_nnode(c, nnode, iip);
 609                if (IS_ERR(nnode))
 610                        return (void *)nnode;
 611        }
 612
 613        for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
 614                if (nnode->nbranch[iip].lnum)
 615                        break;
 616        if (iip >= UBIFS_LPT_FANOUT)
 617                /* Should not happen, but we need to keep going if it does */
 618                iip = 0;
 619        return ubifs_get_pnode(c, nnode, iip);
 620}
 621
 622/**
 623 * pnode_lookup - lookup a pnode in the LPT.
 624 * @c: UBIFS file-system description object
 625 * @i: pnode number (0 to main_lebs - 1)
 626 *
 627 * This function returns a pointer to the pnode on success or a negative
 628 * error code on failure.
 629 */
 630static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
 631{
 632        int err, h, iip, shft;
 633        struct ubifs_nnode *nnode;
 634
 635        if (!c->nroot) {
 636                err = ubifs_read_nnode(c, NULL, 0);
 637                if (err)
 638                        return ERR_PTR(err);
 639        }
 640        i <<= UBIFS_LPT_FANOUT_SHIFT;
 641        nnode = c->nroot;
 642        shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
 643        for (h = 1; h < c->lpt_hght; h++) {
 644                iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
 645                shft -= UBIFS_LPT_FANOUT_SHIFT;
 646                nnode = ubifs_get_nnode(c, nnode, iip);
 647                if (IS_ERR(nnode))
 648                        return ERR_CAST(nnode);
 649        }
 650        iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
 651        return ubifs_get_pnode(c, nnode, iip);
 652}
 653
 654/**
 655 * add_pnode_dirt - add dirty space to LPT LEB properties.
 656 * @c: UBIFS file-system description object
 657 * @pnode: pnode for which to add dirt
 658 */
 659static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
 660{
 661        ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
 662                           c->pnode_sz);
 663}
 664
 665/**
 666 * do_make_pnode_dirty - mark a pnode dirty.
 667 * @c: UBIFS file-system description object
 668 * @pnode: pnode to mark dirty
 669 */
 670static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
 671{
 672        /* Assumes cnext list is empty i.e. not called during commit */
 673        if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
 674                struct ubifs_nnode *nnode;
 675
 676                c->dirty_pn_cnt += 1;
 677                add_pnode_dirt(c, pnode);
 678                /* Mark parent and ancestors dirty too */
 679                nnode = pnode->parent;
 680                while (nnode) {
 681                        if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 682                                c->dirty_nn_cnt += 1;
 683                                ubifs_add_nnode_dirt(c, nnode);
 684                                nnode = nnode->parent;
 685                        } else
 686                                break;
 687                }
 688        }
 689}
 690
 691/**
 692 * make_tree_dirty - mark the entire LEB properties tree dirty.
 693 * @c: UBIFS file-system description object
 694 *
 695 * This function is used by the "small" LPT model to cause the entire LEB
 696 * properties tree to be written.  The "small" LPT model does not use LPT
 697 * garbage collection because it is more efficient to write the entire tree
 698 * (because it is small).
 699 *
 700 * This function returns %0 on success and a negative error code on failure.
 701 */
 702static int make_tree_dirty(struct ubifs_info *c)
 703{
 704        struct ubifs_pnode *pnode;
 705
 706        pnode = pnode_lookup(c, 0);
 707        if (IS_ERR(pnode))
 708                return PTR_ERR(pnode);
 709
 710        while (pnode) {
 711                do_make_pnode_dirty(c, pnode);
 712                pnode = next_pnode_to_dirty(c, pnode);
 713                if (IS_ERR(pnode))
 714                        return PTR_ERR(pnode);
 715        }
 716        return 0;
 717}
 718
 719/**
 720 * need_write_all - determine if the LPT area is running out of free space.
 721 * @c: UBIFS file-system description object
 722 *
 723 * This function returns %1 if the LPT area is running out of free space and %0
 724 * if it is not.
 725 */
 726static int need_write_all(struct ubifs_info *c)
 727{
 728        long long free = 0;
 729        int i;
 730
 731        for (i = 0; i < c->lpt_lebs; i++) {
 732                if (i + c->lpt_first == c->nhead_lnum)
 733                        free += c->leb_size - c->nhead_offs;
 734                else if (c->ltab[i].free == c->leb_size)
 735                        free += c->leb_size;
 736                else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
 737                        free += c->leb_size;
 738        }
 739        /* Less than twice the size left */
 740        if (free <= c->lpt_sz * 2)
 741                return 1;
 742        return 0;
 743}
 744
 745/**
 746 * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
 747 * @c: UBIFS file-system description object
 748 *
 749 * LPT trivial garbage collection is where a LPT LEB contains only dirty and
 750 * free space and so may be reused as soon as the next commit is completed.
 751 * This function is called during start commit to mark LPT LEBs for trivial GC.
 752 */
 753static void lpt_tgc_start(struct ubifs_info *c)
 754{
 755        int i;
 756
 757        for (i = 0; i < c->lpt_lebs; i++) {
 758                if (i + c->lpt_first == c->nhead_lnum)
 759                        continue;
 760                if (c->ltab[i].dirty > 0 &&
 761                    c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
 762                        c->ltab[i].tgc = 1;
 763                        c->ltab[i].free = c->leb_size;
 764                        c->ltab[i].dirty = 0;
 765                        dbg_lp("LEB %d", i + c->lpt_first);
 766                }
 767        }
 768}
 769
 770/**
 771 * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
 772 * @c: UBIFS file-system description object
 773 *
 774 * LPT trivial garbage collection is where a LPT LEB contains only dirty and
 775 * free space and so may be reused as soon as the next commit is completed.
 776 * This function is called after the commit is completed (master node has been
 777 * written) and un-maps LPT LEBs that were marked for trivial GC.
 778 */
 779static int lpt_tgc_end(struct ubifs_info *c)
 780{
 781        int i, err;
 782
 783        for (i = 0; i < c->lpt_lebs; i++)
 784                if (c->ltab[i].tgc) {
 785                        err = ubifs_leb_unmap(c, i + c->lpt_first);
 786                        if (err)
 787                                return err;
 788                        c->ltab[i].tgc = 0;
 789                        dbg_lp("LEB %d", i + c->lpt_first);
 790                }
 791        return 0;
 792}
 793
 794/**
 795 * populate_lsave - fill the lsave array with important LEB numbers.
 796 * @c: the UBIFS file-system description object
 797 *
 798 * This function is only called for the "big" model. It records a small number
 799 * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
 800 * most important to least important): empty, freeable, freeable index, dirty
 801 * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
 802 * their pnodes into memory.  That will stop us from having to scan the LPT
 803 * straight away. For the "small" model we assume that scanning the LPT is no
 804 * big deal.
 805 */
 806static void populate_lsave(struct ubifs_info *c)
 807{
 808        struct ubifs_lprops *lprops;
 809        struct ubifs_lpt_heap *heap;
 810        int i, cnt = 0;
 811
 812        ubifs_assert(c->big_lpt);
 813        if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
 814                c->lpt_drty_flgs |= LSAVE_DIRTY;
 815                ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
 816        }
 817
 818        if (dbg_populate_lsave(c))
 819                return;
 820
 821        list_for_each_entry(lprops, &c->empty_list, list) {
 822                c->lsave[cnt++] = lprops->lnum;
 823                if (cnt >= c->lsave_cnt)
 824                        return;
 825        }
 826        list_for_each_entry(lprops, &c->freeable_list, list) {
 827                c->lsave[cnt++] = lprops->lnum;
 828                if (cnt >= c->lsave_cnt)
 829                        return;
 830        }
 831        list_for_each_entry(lprops, &c->frdi_idx_list, list) {
 832                c->lsave[cnt++] = lprops->lnum;
 833                if (cnt >= c->lsave_cnt)
 834                        return;
 835        }
 836        heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
 837        for (i = 0; i < heap->cnt; i++) {
 838                c->lsave[cnt++] = heap->arr[i]->lnum;
 839                if (cnt >= c->lsave_cnt)
 840                        return;
 841        }
 842        heap = &c->lpt_heap[LPROPS_DIRTY - 1];
 843        for (i = 0; i < heap->cnt; i++) {
 844                c->lsave[cnt++] = heap->arr[i]->lnum;
 845                if (cnt >= c->lsave_cnt)
 846                        return;
 847        }
 848        heap = &c->lpt_heap[LPROPS_FREE - 1];
 849        for (i = 0; i < heap->cnt; i++) {
 850                c->lsave[cnt++] = heap->arr[i]->lnum;
 851                if (cnt >= c->lsave_cnt)
 852                        return;
 853        }
 854        /* Fill it up completely */
 855        while (cnt < c->lsave_cnt)
 856                c->lsave[cnt++] = c->main_first;
 857}
 858
 859/**
 860 * nnode_lookup - lookup a nnode in the LPT.
 861 * @c: UBIFS file-system description object
 862 * @i: nnode number
 863 *
 864 * This function returns a pointer to the nnode on success or a negative
 865 * error code on failure.
 866 */
 867static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
 868{
 869        int err, iip;
 870        struct ubifs_nnode *nnode;
 871
 872        if (!c->nroot) {
 873                err = ubifs_read_nnode(c, NULL, 0);
 874                if (err)
 875                        return ERR_PTR(err);
 876        }
 877        nnode = c->nroot;
 878        while (1) {
 879                iip = i & (UBIFS_LPT_FANOUT - 1);
 880                i >>= UBIFS_LPT_FANOUT_SHIFT;
 881                if (!i)
 882                        break;
 883                nnode = ubifs_get_nnode(c, nnode, iip);
 884                if (IS_ERR(nnode))
 885                        return nnode;
 886        }
 887        return nnode;
 888}
 889
 890/**
 891 * make_nnode_dirty - find a nnode and, if found, make it dirty.
 892 * @c: UBIFS file-system description object
 893 * @node_num: nnode number of nnode to make dirty
 894 * @lnum: LEB number where nnode was written
 895 * @offs: offset where nnode was written
 896 *
 897 * This function is used by LPT garbage collection.  LPT garbage collection is
 898 * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 899 * simply involves marking all the nodes in the LEB being garbage-collected as
 900 * dirty.  The dirty nodes are written next commit, after which the LEB is free
 901 * to be reused.
 902 *
 903 * This function returns %0 on success and a negative error code on failure.
 904 */
 905static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
 906                            int offs)
 907{
 908        struct ubifs_nnode *nnode;
 909
 910        nnode = nnode_lookup(c, node_num);
 911        if (IS_ERR(nnode))
 912                return PTR_ERR(nnode);
 913        if (nnode->parent) {
 914                struct ubifs_nbranch *branch;
 915
 916                branch = &nnode->parent->nbranch[nnode->iip];
 917                if (branch->lnum != lnum || branch->offs != offs)
 918                        return 0; /* nnode is obsolete */
 919        } else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
 920                        return 0; /* nnode is obsolete */
 921        /* Assumes cnext list is empty i.e. not called during commit */
 922        if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 923                c->dirty_nn_cnt += 1;
 924                ubifs_add_nnode_dirt(c, nnode);
 925                /* Mark parent and ancestors dirty too */
 926                nnode = nnode->parent;
 927                while (nnode) {
 928                        if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 929                                c->dirty_nn_cnt += 1;
 930                                ubifs_add_nnode_dirt(c, nnode);
 931                                nnode = nnode->parent;
 932                        } else
 933                                break;
 934                }
 935        }
 936        return 0;
 937}
 938
 939/**
 940 * make_pnode_dirty - find a pnode and, if found, make it dirty.
 941 * @c: UBIFS file-system description object
 942 * @node_num: pnode number of pnode to make dirty
 943 * @lnum: LEB number where pnode was written
 944 * @offs: offset where pnode was written
 945 *
 946 * This function is used by LPT garbage collection.  LPT garbage collection is
 947 * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 948 * simply involves marking all the nodes in the LEB being garbage-collected as
 949 * dirty.  The dirty nodes are written next commit, after which the LEB is free
 950 * to be reused.
 951 *
 952 * This function returns %0 on success and a negative error code on failure.
 953 */
 954static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
 955                            int offs)
 956{
 957        struct ubifs_pnode *pnode;
 958        struct ubifs_nbranch *branch;
 959
 960        pnode = pnode_lookup(c, node_num);
 961        if (IS_ERR(pnode))
 962                return PTR_ERR(pnode);
 963        branch = &pnode->parent->nbranch[pnode->iip];
 964        if (branch->lnum != lnum || branch->offs != offs)
 965                return 0;
 966        do_make_pnode_dirty(c, pnode);
 967        return 0;
 968}
 969
 970/**
 971 * make_ltab_dirty - make ltab node dirty.
 972 * @c: UBIFS file-system description object
 973 * @lnum: LEB number where ltab was written
 974 * @offs: offset where ltab was written
 975 *
 976 * This function is used by LPT garbage collection.  LPT garbage collection is
 977 * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 978 * simply involves marking all the nodes in the LEB being garbage-collected as
 979 * dirty.  The dirty nodes are written next commit, after which the LEB is free
 980 * to be reused.
 981 *
 982 * This function returns %0 on success and a negative error code on failure.
 983 */
 984static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
 985{
 986        if (lnum != c->ltab_lnum || offs != c->ltab_offs)
 987                return 0; /* This ltab node is obsolete */
 988        if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
 989                c->lpt_drty_flgs |= LTAB_DIRTY;
 990                ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
 991        }
 992        return 0;
 993}
 994
 995/**
 996 * make_lsave_dirty - make lsave node dirty.
 997 * @c: UBIFS file-system description object
 998 * @lnum: LEB number where lsave was written
 999 * @offs: offset where lsave was written
1000 *
1001 * This function is used by LPT garbage collection.  LPT garbage collection is
1002 * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1003 * simply involves marking all the nodes in the LEB being garbage-collected as
1004 * dirty.  The dirty nodes are written next commit, after which the LEB is free
1005 * to be reused.
1006 *
1007 * This function returns %0 on success and a negative error code on failure.
1008 */
1009static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1010{
1011        if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1012                return 0; /* This lsave node is obsolete */
1013        if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
1014                c->lpt_drty_flgs |= LSAVE_DIRTY;
1015                ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
1016        }
1017        return 0;
1018}
1019
1020/**
1021 * make_node_dirty - make node dirty.
1022 * @c: UBIFS file-system description object
1023 * @node_type: LPT node type
1024 * @node_num: node number
1025 * @lnum: LEB number where node was written
1026 * @offs: offset where node was written
1027 *
1028 * This function is used by LPT garbage collection.  LPT garbage collection is
1029 * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1030 * simply involves marking all the nodes in the LEB being garbage-collected as
1031 * dirty.  The dirty nodes are written next commit, after which the LEB is free
1032 * to be reused.
1033 *
1034 * This function returns %0 on success and a negative error code on failure.
1035 */
1036static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
1037                           int lnum, int offs)
1038{
1039        switch (node_type) {
1040        case UBIFS_LPT_NNODE:
1041                return make_nnode_dirty(c, node_num, lnum, offs);
1042        case UBIFS_LPT_PNODE:
1043                return make_pnode_dirty(c, node_num, lnum, offs);
1044        case UBIFS_LPT_LTAB:
1045                return make_ltab_dirty(c, lnum, offs);
1046        case UBIFS_LPT_LSAVE:
1047                return make_lsave_dirty(c, lnum, offs);
1048        }
1049        return -EINVAL;
1050}
1051
1052/**
1053 * get_lpt_node_len - return the length of a node based on its type.
1054 * @c: UBIFS file-system description object
1055 * @node_type: LPT node type
1056 */
1057static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
1058{
1059        switch (node_type) {
1060        case UBIFS_LPT_NNODE:
1061                return c->nnode_sz;
1062        case UBIFS_LPT_PNODE:
1063                return c->pnode_sz;
1064        case UBIFS_LPT_LTAB:
1065                return c->ltab_sz;
1066        case UBIFS_LPT_LSAVE:
1067                return c->lsave_sz;
1068        }
1069        return 0;
1070}
1071
1072/**
1073 * get_pad_len - return the length of padding in a buffer.
1074 * @c: UBIFS file-system description object
1075 * @buf: buffer
1076 * @len: length of buffer
1077 */
1078static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
1079{
1080        int offs, pad_len;
1081
1082        if (c->min_io_size == 1)
1083                return 0;
1084        offs = c->leb_size - len;
1085        pad_len = ALIGN(offs, c->min_io_size) - offs;
1086        return pad_len;
1087}
1088
1089/**
1090 * get_lpt_node_type - return type (and node number) of a node in a buffer.
1091 * @c: UBIFS file-system description object
1092 * @buf: buffer
1093 * @node_num: node number is returned here
1094 */
1095static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
1096                             int *node_num)
1097{
1098        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1099        int pos = 0, node_type;
1100
1101        node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1102        *node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1103        return node_type;
1104}
1105
1106/**
1107 * is_a_node - determine if a buffer contains a node.
1108 * @c: UBIFS file-system description object
1109 * @buf: buffer
1110 * @len: length of buffer
1111 *
1112 * This function returns %1 if the buffer contains a node or %0 if it does not.
1113 */
1114static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
1115{
1116        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1117        int pos = 0, node_type, node_len;
1118        uint16_t crc, calc_crc;
1119
1120        if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
1121                return 0;
1122        node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1123        if (node_type == UBIFS_LPT_NOT_A_NODE)
1124                return 0;
1125        node_len = get_lpt_node_len(c, node_type);
1126        if (!node_len || node_len > len)
1127                return 0;
1128        pos = 0;
1129        addr = buf;
1130        crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
1131        calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
1132                         node_len - UBIFS_LPT_CRC_BYTES);
1133        if (crc != calc_crc)
1134                return 0;
1135        return 1;
1136}
1137
1138/**
1139 * lpt_gc_lnum - garbage collect a LPT LEB.
1140 * @c: UBIFS file-system description object
1141 * @lnum: LEB number to garbage collect
1142 *
1143 * LPT garbage collection is used only for the "big" LPT model
1144 * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
1145 * in the LEB being garbage-collected as dirty.  The dirty nodes are written
1146 * next commit, after which the LEB is free to be reused.
1147 *
1148 * This function returns %0 on success and a negative error code on failure.
1149 */
1150static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
1151{
1152        int err, len = c->leb_size, node_type, node_num, node_len, offs;
1153        void *buf = c->lpt_buf;
1154
1155        dbg_lp("LEB %d", lnum);
1156
1157        err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1158        if (err)
1159                return err;
1160
1161        while (1) {
1162                if (!is_a_node(c, buf, len)) {
1163                        int pad_len;
1164
1165                        pad_len = get_pad_len(c, buf, len);
1166                        if (pad_len) {
1167                                buf += pad_len;
1168                                len -= pad_len;
1169                                continue;
1170                        }
1171                        return 0;
1172                }
1173                node_type = get_lpt_node_type(c, buf, &node_num);
1174                node_len = get_lpt_node_len(c, node_type);
1175                offs = c->leb_size - len;
1176                ubifs_assert(node_len != 0);
1177                mutex_lock(&c->lp_mutex);
1178                err = make_node_dirty(c, node_type, node_num, lnum, offs);
1179                mutex_unlock(&c->lp_mutex);
1180                if (err)
1181                        return err;
1182                buf += node_len;
1183                len -= node_len;
1184        }
1185        return 0;
1186}
1187
1188/**
1189 * lpt_gc - LPT garbage collection.
1190 * @c: UBIFS file-system description object
1191 *
1192 * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
1193 * Returns %0 on success and a negative error code on failure.
1194 */
1195static int lpt_gc(struct ubifs_info *c)
1196{
1197        int i, lnum = -1, dirty = 0;
1198
1199        mutex_lock(&c->lp_mutex);
1200        for (i = 0; i < c->lpt_lebs; i++) {
1201                ubifs_assert(!c->ltab[i].tgc);
1202                if (i + c->lpt_first == c->nhead_lnum ||
1203                    c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
1204                        continue;
1205                if (c->ltab[i].dirty > dirty) {
1206                        dirty = c->ltab[i].dirty;
1207                        lnum = i + c->lpt_first;
1208                }
1209        }
1210        mutex_unlock(&c->lp_mutex);
1211        if (lnum == -1)
1212                return -ENOSPC;
1213        return lpt_gc_lnum(c, lnum);
1214}
1215
1216/**
1217 * ubifs_lpt_start_commit - UBIFS commit starts.
1218 * @c: the UBIFS file-system description object
1219 *
1220 * This function has to be called when UBIFS starts the commit operation.
1221 * This function "freezes" all currently dirty LEB properties and does not
1222 * change them anymore. Further changes are saved and tracked separately
1223 * because they are not part of this commit. This function returns zero in case
1224 * of success and a negative error code in case of failure.
1225 */
1226int ubifs_lpt_start_commit(struct ubifs_info *c)
1227{
1228        int err, cnt;
1229
1230        dbg_lp("");
1231
1232        mutex_lock(&c->lp_mutex);
1233        err = dbg_chk_lpt_free_spc(c);
1234        if (err)
1235                goto out;
1236        err = dbg_check_ltab(c);
1237        if (err)
1238                goto out;
1239
1240        if (c->check_lpt_free) {
1241                /*
1242                 * We ensure there is enough free space in
1243                 * ubifs_lpt_post_commit() by marking nodes dirty. That
1244                 * information is lost when we unmount, so we also need
1245                 * to check free space once after mounting also.
1246                 */
1247                c->check_lpt_free = 0;
1248                while (need_write_all(c)) {
1249                        mutex_unlock(&c->lp_mutex);
1250                        err = lpt_gc(c);
1251                        if (err)
1252                                return err;
1253                        mutex_lock(&c->lp_mutex);
1254                }
1255        }
1256
1257        lpt_tgc_start(c);
1258
1259        if (!c->dirty_pn_cnt) {
1260                dbg_cmt("no cnodes to commit");
1261                err = 0;
1262                goto out;
1263        }
1264
1265        if (!c->big_lpt && need_write_all(c)) {
1266                /* If needed, write everything */
1267                err = make_tree_dirty(c);
1268                if (err)
1269                        goto out;
1270                lpt_tgc_start(c);
1271        }
1272
1273        if (c->big_lpt)
1274                populate_lsave(c);
1275
1276        cnt = get_cnodes_to_commit(c);
1277        ubifs_assert(cnt != 0);
1278
1279        err = layout_cnodes(c);
1280        if (err)
1281                goto out;
1282
1283        /* Copy the LPT's own lprops for end commit to write */
1284        memcpy(c->ltab_cmt, c->ltab,
1285               sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1286        c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
1287
1288out:
1289        mutex_unlock(&c->lp_mutex);
1290        return err;
1291}
1292
1293/**
1294 * free_obsolete_cnodes - free obsolete cnodes for commit end.
1295 * @c: UBIFS file-system description object
1296 */
1297static void free_obsolete_cnodes(struct ubifs_info *c)
1298{
1299        struct ubifs_cnode *cnode, *cnext;
1300
1301        cnext = c->lpt_cnext;
1302        if (!cnext)
1303                return;
1304        do {
1305                cnode = cnext;
1306                cnext = cnode->cnext;
1307                if (test_bit(OBSOLETE_CNODE, &cnode->flags))
1308                        kfree(cnode);
1309                else
1310                        cnode->cnext = NULL;
1311        } while (cnext != c->lpt_cnext);
1312        c->lpt_cnext = NULL;
1313}
1314
1315/**
1316 * ubifs_lpt_end_commit - finish the commit operation.
1317 * @c: the UBIFS file-system description object
1318 *
1319 * This function has to be called when the commit operation finishes. It
1320 * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1321 * the media. Returns zero in case of success and a negative error code in case
1322 * of failure.
1323 */
1324int ubifs_lpt_end_commit(struct ubifs_info *c)
1325{
1326        int err;
1327
1328        dbg_lp("");
1329
1330        if (!c->lpt_cnext)
1331                return 0;
1332
1333        err = write_cnodes(c);
1334        if (err)
1335                return err;
1336
1337        mutex_lock(&c->lp_mutex);
1338        free_obsolete_cnodes(c);
1339        mutex_unlock(&c->lp_mutex);
1340
1341        return 0;
1342}
1343
1344/**
1345 * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1346 * @c: UBIFS file-system description object
1347 *
1348 * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1349 * commit for the "big" LPT model.
1350 */
1351int ubifs_lpt_post_commit(struct ubifs_info *c)
1352{
1353        int err;
1354
1355        mutex_lock(&c->lp_mutex);
1356        err = lpt_tgc_end(c);
1357        if (err)
1358                goto out;
1359        if (c->big_lpt)
1360                while (need_write_all(c)) {
1361                        mutex_unlock(&c->lp_mutex);
1362                        err = lpt_gc(c);
1363                        if (err)
1364                                return err;
1365                        mutex_lock(&c->lp_mutex);
1366                }
1367out:
1368        mutex_unlock(&c->lp_mutex);
1369        return err;
1370}
1371
1372/**
1373 * first_nnode - find the first nnode in memory.
1374 * @c: UBIFS file-system description object
1375 * @hght: height of tree where nnode found is returned here
1376 *
1377 * This function returns a pointer to the nnode found or %NULL if no nnode is
1378 * found. This function is a helper to 'ubifs_lpt_free()'.
1379 */
1380static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1381{
1382        struct ubifs_nnode *nnode;
1383        int h, i, found;
1384
1385        nnode = c->nroot;
1386        *hght = 0;
1387        if (!nnode)
1388                return NULL;
1389        for (h = 1; h < c->lpt_hght; h++) {
1390                found = 0;
1391                for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1392                        if (nnode->nbranch[i].nnode) {
1393                                found = 1;
1394                                nnode = nnode->nbranch[i].nnode;
1395                                *hght = h;
1396                                break;
1397                        }
1398                }
1399                if (!found)
1400                        break;
1401        }
1402        return nnode;
1403}
1404
1405/**
1406 * next_nnode - find the next nnode in memory.
1407 * @c: UBIFS file-system description object
1408 * @nnode: nnode from which to start.
1409 * @hght: height of tree where nnode is, is passed and returned here
1410 *
1411 * This function returns a pointer to the nnode found or %NULL if no nnode is
1412 * found. This function is a helper to 'ubifs_lpt_free()'.
1413 */
1414static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1415                                      struct ubifs_nnode *nnode, int *hght)
1416{
1417        struct ubifs_nnode *parent;
1418        int iip, h, i, found;
1419
1420        parent = nnode->parent;
1421        if (!parent)
1422                return NULL;
1423        if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1424                *hght -= 1;
1425                return parent;
1426        }
1427        for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1428                nnode = parent->nbranch[iip].nnode;
1429                if (nnode)
1430                        break;
1431        }
1432        if (!nnode) {
1433                *hght -= 1;
1434                return parent;
1435        }
1436        for (h = *hght + 1; h < c->lpt_hght; h++) {
1437                found = 0;
1438                for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1439                        if (nnode->nbranch[i].nnode) {
1440                                found = 1;
1441                                nnode = nnode->nbranch[i].nnode;
1442                                *hght = h;
1443                                break;
1444                        }
1445                }
1446                if (!found)
1447                        break;
1448        }
1449        return nnode;
1450}
1451
1452/**
1453 * ubifs_lpt_free - free resources owned by the LPT.
1454 * @c: UBIFS file-system description object
1455 * @wr_only: free only resources used for writing
1456 */
1457void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1458{
1459        struct ubifs_nnode *nnode;
1460        int i, hght;
1461
1462        /* Free write-only things first */
1463
1464        free_obsolete_cnodes(c); /* Leftover from a failed commit */
1465
1466        vfree(c->ltab_cmt);
1467        c->ltab_cmt = NULL;
1468        vfree(c->lpt_buf);
1469        c->lpt_buf = NULL;
1470        kfree(c->lsave);
1471        c->lsave = NULL;
1472
1473        if (wr_only)
1474                return;
1475
1476        /* Now free the rest */
1477
1478        nnode = first_nnode(c, &hght);
1479        while (nnode) {
1480                for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1481                        kfree(nnode->nbranch[i].nnode);
1482                nnode = next_nnode(c, nnode, &hght);
1483        }
1484        for (i = 0; i < LPROPS_HEAP_CNT; i++)
1485                kfree(c->lpt_heap[i].arr);
1486        kfree(c->dirty_idx.arr);
1487        kfree(c->nroot);
1488        vfree(c->ltab);
1489        kfree(c->lpt_nod_buf);
1490}
1491
1492/*
1493 * Everything below is related to debugging.
1494 */
1495
1496/**
1497 * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1498 * @buf: buffer
1499 * @len: buffer length
1500 */
1501static int dbg_is_all_ff(uint8_t *buf, int len)
1502{
1503        int i;
1504
1505        for (i = 0; i < len; i++)
1506                if (buf[i] != 0xff)
1507                        return 0;
1508        return 1;
1509}
1510
1511/**
1512 * dbg_is_nnode_dirty - determine if a nnode is dirty.
1513 * @c: the UBIFS file-system description object
1514 * @lnum: LEB number where nnode was written
1515 * @offs: offset where nnode was written
1516 */
1517static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1518{
1519        struct ubifs_nnode *nnode;
1520        int hght;
1521
1522        /* Entire tree is in memory so first_nnode / next_nnode are OK */
1523        nnode = first_nnode(c, &hght);
1524        for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1525                struct ubifs_nbranch *branch;
1526
1527                cond_resched();
1528                if (nnode->parent) {
1529                        branch = &nnode->parent->nbranch[nnode->iip];
1530                        if (branch->lnum != lnum || branch->offs != offs)
1531                                continue;
1532                        if (test_bit(DIRTY_CNODE, &nnode->flags))
1533                                return 1;
1534                        return 0;
1535                } else {
1536                        if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1537                                continue;
1538                        if (test_bit(DIRTY_CNODE, &nnode->flags))
1539                                return 1;
1540                        return 0;
1541                }
1542        }
1543        return 1;
1544}
1545
1546/**
1547 * dbg_is_pnode_dirty - determine if a pnode is dirty.
1548 * @c: the UBIFS file-system description object
1549 * @lnum: LEB number where pnode was written
1550 * @offs: offset where pnode was written
1551 */
1552static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1553{
1554        int i, cnt;
1555
1556        cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1557        for (i = 0; i < cnt; i++) {
1558                struct ubifs_pnode *pnode;
1559                struct ubifs_nbranch *branch;
1560
1561                cond_resched();
1562                pnode = pnode_lookup(c, i);
1563                if (IS_ERR(pnode))
1564                        return PTR_ERR(pnode);
1565                branch = &pnode->parent->nbranch[pnode->iip];
1566                if (branch->lnum != lnum || branch->offs != offs)
1567                        continue;
1568                if (test_bit(DIRTY_CNODE, &pnode->flags))
1569                        return 1;
1570                return 0;
1571        }
1572        return 1;
1573}
1574
1575/**
1576 * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1577 * @c: the UBIFS file-system description object
1578 * @lnum: LEB number where ltab node was written
1579 * @offs: offset where ltab node was written
1580 */
1581static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1582{
1583        if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1584                return 1;
1585        return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1586}
1587
1588/**
1589 * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1590 * @c: the UBIFS file-system description object
1591 * @lnum: LEB number where lsave node was written
1592 * @offs: offset where lsave node was written
1593 */
1594static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1595{
1596        if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1597                return 1;
1598        return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1599}
1600
1601/**
1602 * dbg_is_node_dirty - determine if a node is dirty.
1603 * @c: the UBIFS file-system description object
1604 * @node_type: node type
1605 * @lnum: LEB number where node was written
1606 * @offs: offset where node was written
1607 */
1608static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1609                             int offs)
1610{
1611        switch (node_type) {
1612        case UBIFS_LPT_NNODE:
1613                return dbg_is_nnode_dirty(c, lnum, offs);
1614        case UBIFS_LPT_PNODE:
1615                return dbg_is_pnode_dirty(c, lnum, offs);
1616        case UBIFS_LPT_LTAB:
1617                return dbg_is_ltab_dirty(c, lnum, offs);
1618        case UBIFS_LPT_LSAVE:
1619                return dbg_is_lsave_dirty(c, lnum, offs);
1620        }
1621        return 1;
1622}
1623
1624/**
1625 * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1626 * @c: the UBIFS file-system description object
1627 * @lnum: LEB number where node was written
1628 * @offs: offset where node was written
1629 *
1630 * This function returns %0 on success and a negative error code on failure.
1631 */
1632static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1633{
1634        int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1635        int ret;
1636        void *buf, *p;
1637
1638        if (!dbg_is_chk_lprops(c))
1639                return 0;
1640
1641        buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1642        if (!buf) {
1643                ubifs_err("cannot allocate memory for ltab checking");
1644                return 0;
1645        }
1646
1647        dbg_lp("LEB %d", lnum);
1648
1649        err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1650        if (err)
1651                goto out;
1652
1653        while (1) {
1654                if (!is_a_node(c, p, len)) {
1655                        int i, pad_len;
1656
1657                        pad_len = get_pad_len(c, p, len);
1658                        if (pad_len) {
1659                                p += pad_len;
1660                                len -= pad_len;
1661                                dirty += pad_len;
1662                                continue;
1663                        }
1664                        if (!dbg_is_all_ff(p, len)) {
1665                                dbg_msg("invalid empty space in LEB %d at %d",
1666                                        lnum, c->leb_size - len);
1667                                err = -EINVAL;
1668                        }
1669                        i = lnum - c->lpt_first;
1670                        if (len != c->ltab[i].free) {
1671                                dbg_msg("invalid free space in LEB %d "
1672                                        "(free %d, expected %d)",
1673                                        lnum, len, c->ltab[i].free);
1674                                err = -EINVAL;
1675                        }
1676                        if (dirty != c->ltab[i].dirty) {
1677                                dbg_msg("invalid dirty space in LEB %d "
1678                                        "(dirty %d, expected %d)",
1679                                        lnum, dirty, c->ltab[i].dirty);
1680                                err = -EINVAL;
1681                        }
1682                        goto out;
1683                }
1684                node_type = get_lpt_node_type(c, p, &node_num);
1685                node_len = get_lpt_node_len(c, node_type);
1686                ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1687                if (ret == 1)
1688                        dirty += node_len;
1689                p += node_len;
1690                len -= node_len;
1691        }
1692
1693        err = 0;
1694out:
1695        vfree(buf);
1696        return err;
1697}
1698
1699/**
1700 * dbg_check_ltab - check the free and dirty space in the ltab.
1701 * @c: the UBIFS file-system description object
1702 *
1703 * This function returns %0 on success and a negative error code on failure.
1704 */
1705int dbg_check_ltab(struct ubifs_info *c)
1706{
1707        int lnum, err, i, cnt;
1708
1709        if (!dbg_is_chk_lprops(c))
1710                return 0;
1711
1712        /* Bring the entire tree into memory */
1713        cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1714        for (i = 0; i < cnt; i++) {
1715                struct ubifs_pnode *pnode;
1716
1717                pnode = pnode_lookup(c, i);
1718                if (IS_ERR(pnode))
1719                        return PTR_ERR(pnode);
1720                cond_resched();
1721        }
1722
1723        /* Check nodes */
1724        err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1725        if (err)
1726                return err;
1727
1728        /* Check each LEB */
1729        for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1730                err = dbg_check_ltab_lnum(c, lnum);
1731                if (err) {
1732                        ubifs_err("failed at LEB %d", lnum);
1733                        return err;
1734                }
1735        }
1736
1737        dbg_lp("succeeded");
1738        return 0;
1739}
1740
1741/**
1742 * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1743 * @c: the UBIFS file-system description object
1744 *
1745 * This function returns %0 on success and a negative error code on failure.
1746 */
1747int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1748{
1749        long long free = 0;
1750        int i;
1751
1752        if (!dbg_is_chk_lprops(c))
1753                return 0;
1754
1755        for (i = 0; i < c->lpt_lebs; i++) {
1756                if (c->ltab[i].tgc || c->ltab[i].cmt)
1757                        continue;
1758                if (i + c->lpt_first == c->nhead_lnum)
1759                        free += c->leb_size - c->nhead_offs;
1760                else if (c->ltab[i].free == c->leb_size)
1761                        free += c->leb_size;
1762        }
1763        if (free < c->lpt_sz) {
1764                ubifs_err("LPT space error: free %lld lpt_sz %lld",
1765                          free, c->lpt_sz);
1766                ubifs_dump_lpt_info(c);
1767                ubifs_dump_lpt_lebs(c);
1768                dump_stack();
1769                return -EINVAL;
1770        }
1771        return 0;
1772}
1773
1774/**
1775 * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1776 * @c: the UBIFS file-system description object
1777 * @action: what to do
1778 * @len: length written
1779 *
1780 * This function returns %0 on success and a negative error code on failure.
1781 * The @action argument may be one of:
1782 *   o %0 - LPT debugging checking starts, initialize debugging variables;
1783 *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1784 *   o %2 - switched to a different LEB and wasted @len bytes;
1785 *   o %3 - check that we've written the right number of bytes.
1786 *   o %4 - wasted @len bytes;
1787 */
1788int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1789{
1790        struct ubifs_debug_info *d = c->dbg;
1791        long long chk_lpt_sz, lpt_sz;
1792        int err = 0;
1793
1794        if (!dbg_is_chk_lprops(c))
1795                return 0;
1796
1797        switch (action) {
1798        case 0:
1799                d->chk_lpt_sz = 0;
1800                d->chk_lpt_sz2 = 0;
1801                d->chk_lpt_lebs = 0;
1802                d->chk_lpt_wastage = 0;
1803                if (c->dirty_pn_cnt > c->pnode_cnt) {
1804                        ubifs_err("dirty pnodes %d exceed max %d",
1805                                  c->dirty_pn_cnt, c->pnode_cnt);
1806                        err = -EINVAL;
1807                }
1808                if (c->dirty_nn_cnt > c->nnode_cnt) {
1809                        ubifs_err("dirty nnodes %d exceed max %d",
1810                                  c->dirty_nn_cnt, c->nnode_cnt);
1811                        err = -EINVAL;
1812                }
1813                return err;
1814        case 1:
1815                d->chk_lpt_sz += len;
1816                return 0;
1817        case 2:
1818                d->chk_lpt_sz += len;
1819                d->chk_lpt_wastage += len;
1820                d->chk_lpt_lebs += 1;
1821                return 0;
1822        case 3:
1823                chk_lpt_sz = c->leb_size;
1824                chk_lpt_sz *= d->chk_lpt_lebs;
1825                chk_lpt_sz += len - c->nhead_offs;
1826                if (d->chk_lpt_sz != chk_lpt_sz) {
1827                        ubifs_err("LPT wrote %lld but space used was %lld",
1828                                  d->chk_lpt_sz, chk_lpt_sz);
1829                        err = -EINVAL;
1830                }
1831                if (d->chk_lpt_sz > c->lpt_sz) {
1832                        ubifs_err("LPT wrote %lld but lpt_sz is %lld",
1833                                  d->chk_lpt_sz, c->lpt_sz);
1834                        err = -EINVAL;
1835                }
1836                if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1837                        ubifs_err("LPT layout size %lld but wrote %lld",
1838                                  d->chk_lpt_sz, d->chk_lpt_sz2);
1839                        err = -EINVAL;
1840                }
1841                if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1842                        ubifs_err("LPT new nhead offs: expected %d was %d",
1843                                  d->new_nhead_offs, len);
1844                        err = -EINVAL;
1845                }
1846                lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1847                lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1848                lpt_sz += c->ltab_sz;
1849                if (c->big_lpt)
1850                        lpt_sz += c->lsave_sz;
1851                if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1852                        ubifs_err("LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1853                                  d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1854                        err = -EINVAL;
1855                }
1856                if (err) {
1857                        ubifs_dump_lpt_info(c);
1858                        ubifs_dump_lpt_lebs(c);
1859                        dump_stack();
1860                }
1861                d->chk_lpt_sz2 = d->chk_lpt_sz;
1862                d->chk_lpt_sz = 0;
1863                d->chk_lpt_wastage = 0;
1864                d->chk_lpt_lebs = 0;
1865                d->new_nhead_offs = len;
1866                return err;
1867        case 4:
1868                d->chk_lpt_sz += len;
1869                d->chk_lpt_wastage += len;
1870                return 0;
1871        default:
1872                return -EINVAL;
1873        }
1874}
1875
1876/**
1877 * ubifs_dump_lpt_leb - dump an LPT LEB.
1878 * @c: UBIFS file-system description object
1879 * @lnum: LEB number to dump
1880 *
1881 * This function dumps an LEB from LPT area. Nodes in this area are very
1882 * different to nodes in the main area (e.g., they do not have common headers,
1883 * they do not have 8-byte alignments, etc), so we have a separate function to
1884 * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1885 */
1886static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1887{
1888        int err, len = c->leb_size, node_type, node_num, node_len, offs;
1889        void *buf, *p;
1890
1891        printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
1892               current->pid, lnum);
1893        buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1894        if (!buf) {
1895                ubifs_err("cannot allocate memory to dump LPT");
1896                return;
1897        }
1898
1899        err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1900        if (err)
1901                goto out;
1902
1903        while (1) {
1904                offs = c->leb_size - len;
1905                if (!is_a_node(c, p, len)) {
1906                        int pad_len;
1907
1908                        pad_len = get_pad_len(c, p, len);
1909                        if (pad_len) {
1910                                printk(KERN_DEBUG "LEB %d:%d, pad %d bytes\n",
1911                                       lnum, offs, pad_len);
1912                                p += pad_len;
1913                                len -= pad_len;
1914                                continue;
1915                        }
1916                        if (len)
1917                                printk(KERN_DEBUG "LEB %d:%d, free %d bytes\n",
1918                                       lnum, offs, len);
1919                        break;
1920                }
1921
1922                node_type = get_lpt_node_type(c, p, &node_num);
1923                switch (node_type) {
1924                case UBIFS_LPT_PNODE:
1925                {
1926                        node_len = c->pnode_sz;
1927                        if (c->big_lpt)
1928                                printk(KERN_DEBUG "LEB %d:%d, pnode num %d\n",
1929                                       lnum, offs, node_num);
1930                        else
1931                                printk(KERN_DEBUG "LEB %d:%d, pnode\n",
1932                                       lnum, offs);
1933                        break;
1934                }
1935                case UBIFS_LPT_NNODE:
1936                {
1937                        int i;
1938                        struct ubifs_nnode nnode;
1939
1940                        node_len = c->nnode_sz;
1941                        if (c->big_lpt)
1942                                printk(KERN_DEBUG "LEB %d:%d, nnode num %d, ",
1943                                       lnum, offs, node_num);
1944                        else
1945                                printk(KERN_DEBUG "LEB %d:%d, nnode, ",
1946                                       lnum, offs);
1947                        err = ubifs_unpack_nnode(c, p, &nnode);
1948                        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1949                                printk(KERN_CONT "%d:%d", nnode.nbranch[i].lnum,
1950                                       nnode.nbranch[i].offs);
1951                                if (i != UBIFS_LPT_FANOUT - 1)
1952                                        printk(KERN_CONT ", ");
1953                        }
1954                        printk(KERN_CONT "\n");
1955                        break;
1956                }
1957                case UBIFS_LPT_LTAB:
1958                        node_len = c->ltab_sz;
1959                        printk(KERN_DEBUG "LEB %d:%d, ltab\n",
1960                               lnum, offs);
1961                        break;
1962                case UBIFS_LPT_LSAVE:
1963                        node_len = c->lsave_sz;
1964                        printk(KERN_DEBUG "LEB %d:%d, lsave len\n", lnum, offs);
1965                        break;
1966                default:
1967                        ubifs_err("LPT node type %d not recognized", node_type);
1968                        goto out;
1969                }
1970
1971                p += node_len;
1972                len -= node_len;
1973        }
1974
1975        printk(KERN_DEBUG "(pid %d) finish dumping LEB %d\n",
1976               current->pid, lnum);
1977out:
1978        vfree(buf);
1979        return;
1980}
1981
1982/**
1983 * ubifs_dump_lpt_lebs - dump LPT lebs.
1984 * @c: UBIFS file-system description object
1985 *
1986 * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1987 * locked.
1988 */
1989void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
1990{
1991        int i;
1992
1993        printk(KERN_DEBUG "(pid %d) start dumping all LPT LEBs\n",
1994               current->pid);
1995        for (i = 0; i < c->lpt_lebs; i++)
1996                dump_lpt_leb(c, i + c->lpt_first);
1997        printk(KERN_DEBUG "(pid %d) finish dumping all LPT LEBs\n",
1998               current->pid);
1999}
2000
2001/**
2002 * dbg_populate_lsave - debugging version of 'populate_lsave()'
2003 * @c: UBIFS file-system description object
2004 *
2005 * This is a debugging version for 'populate_lsave()' which populates lsave
2006 * with random LEBs instead of useful LEBs, which is good for test coverage.
2007 * Returns zero if lsave has not been populated (this debugging feature is
2008 * disabled) an non-zero if lsave has been populated.
2009 */
2010static int dbg_populate_lsave(struct ubifs_info *c)
2011{
2012        struct ubifs_lprops *lprops;
2013        struct ubifs_lpt_heap *heap;
2014        int i;
2015
2016        if (!dbg_is_chk_gen(c))
2017                return 0;
2018        if (random32() & 3)
2019                return 0;
2020
2021        for (i = 0; i < c->lsave_cnt; i++)
2022                c->lsave[i] = c->main_first;
2023
2024        list_for_each_entry(lprops, &c->empty_list, list)
2025                c->lsave[random32() % c->lsave_cnt] = lprops->lnum;
2026        list_for_each_entry(lprops, &c->freeable_list, list)
2027                c->lsave[random32() % c->lsave_cnt] = lprops->lnum;
2028        list_for_each_entry(lprops, &c->frdi_idx_list, list)
2029                c->lsave[random32() % c->lsave_cnt] = lprops->lnum;
2030
2031        heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
2032        for (i = 0; i < heap->cnt; i++)
2033                c->lsave[random32() % c->lsave_cnt] = heap->arr[i]->lnum;
2034        heap = &c->lpt_heap[LPROPS_DIRTY - 1];
2035        for (i = 0; i < heap->cnt; i++)
2036                c->lsave[random32() % c->lsave_cnt] = heap->arr[i]->lnum;
2037        heap = &c->lpt_heap[LPROPS_FREE - 1];
2038        for (i = 0; i < heap->cnt; i++)
2039                c->lsave[random32() % c->lsave_cnt] = heap->arr[i]->lnum;
2040
2041        return 1;
2042}
2043
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