linux/fs/ubifs/lpt.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 LEB properties tree (LPT) area. The LPT area
  25 * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
  26 * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
  27 * between the log and the orphan area.
  28 *
  29 * The LPT area is like a miniature self-contained file system. It is required
  30 * that it never runs out of space, is fast to access and update, and scales
  31 * logarithmically. The LEB properties tree is implemented as a wandering tree
  32 * much like the TNC, and the LPT area has its own garbage collection.
  33 *
  34 * The LPT has two slightly different forms called the "small model" and the
  35 * "big model". The small model is used when the entire LEB properties table
  36 * can be written into a single eraseblock. In that case, garbage collection
  37 * consists of just writing the whole table, which therefore makes all other
  38 * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
  39 * selected for garbage collection, which consists of marking the clean nodes in
  40 * that LEB as dirty, and then only the dirty nodes are written out. Also, in
  41 * the case of the big model, a table of LEB numbers is saved so that the entire
  42 * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
  43 * mounted.
  44 */
  45
  46#include "ubifs.h"
  47#include <linux/crc16.h>
  48#include <linux/math64.h>
  49#include <linux/slab.h>
  50
  51/**
  52 * do_calc_lpt_geom - calculate sizes for the LPT area.
  53 * @c: the UBIFS file-system description object
  54 *
  55 * Calculate the sizes of LPT bit fields, nodes, and tree, based on the
  56 * properties of the flash and whether LPT is "big" (c->big_lpt).
  57 */
  58static void do_calc_lpt_geom(struct ubifs_info *c)
  59{
  60        int i, n, bits, per_leb_wastage, max_pnode_cnt;
  61        long long sz, tot_wastage;
  62
  63        n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
  64        max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
  65
  66        c->lpt_hght = 1;
  67        n = UBIFS_LPT_FANOUT;
  68        while (n < max_pnode_cnt) {
  69                c->lpt_hght += 1;
  70                n <<= UBIFS_LPT_FANOUT_SHIFT;
  71        }
  72
  73        c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
  74
  75        n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
  76        c->nnode_cnt = n;
  77        for (i = 1; i < c->lpt_hght; i++) {
  78                n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
  79                c->nnode_cnt += n;
  80        }
  81
  82        c->space_bits = fls(c->leb_size) - 3;
  83        c->lpt_lnum_bits = fls(c->lpt_lebs);
  84        c->lpt_offs_bits = fls(c->leb_size - 1);
  85        c->lpt_spc_bits = fls(c->leb_size);
  86
  87        n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
  88        c->pcnt_bits = fls(n - 1);
  89
  90        c->lnum_bits = fls(c->max_leb_cnt - 1);
  91
  92        bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
  93               (c->big_lpt ? c->pcnt_bits : 0) +
  94               (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
  95        c->pnode_sz = (bits + 7) / 8;
  96
  97        bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
  98               (c->big_lpt ? c->pcnt_bits : 0) +
  99               (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
 100        c->nnode_sz = (bits + 7) / 8;
 101
 102        bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
 103               c->lpt_lebs * c->lpt_spc_bits * 2;
 104        c->ltab_sz = (bits + 7) / 8;
 105
 106        bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
 107               c->lnum_bits * c->lsave_cnt;
 108        c->lsave_sz = (bits + 7) / 8;
 109
 110        /* Calculate the minimum LPT size */
 111        c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
 112        c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
 113        c->lpt_sz += c->ltab_sz;
 114        if (c->big_lpt)
 115                c->lpt_sz += c->lsave_sz;
 116
 117        /* Add wastage */
 118        sz = c->lpt_sz;
 119        per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
 120        sz += per_leb_wastage;
 121        tot_wastage = per_leb_wastage;
 122        while (sz > c->leb_size) {
 123                sz += per_leb_wastage;
 124                sz -= c->leb_size;
 125                tot_wastage += per_leb_wastage;
 126        }
 127        tot_wastage += ALIGN(sz, c->min_io_size) - sz;
 128        c->lpt_sz += tot_wastage;
 129}
 130
 131/**
 132 * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
 133 * @c: the UBIFS file-system description object
 134 *
 135 * This function returns %0 on success and a negative error code on failure.
 136 */
 137int ubifs_calc_lpt_geom(struct ubifs_info *c)
 138{
 139        int lebs_needed;
 140        long long sz;
 141
 142        do_calc_lpt_geom(c);
 143
 144        /* Verify that lpt_lebs is big enough */
 145        sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
 146        lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
 147        if (lebs_needed > c->lpt_lebs) {
 148                ubifs_err("too few LPT LEBs");
 149                return -EINVAL;
 150        }
 151
 152        /* Verify that ltab fits in a single LEB (since ltab is a single node */
 153        if (c->ltab_sz > c->leb_size) {
 154                ubifs_err("LPT ltab too big");
 155                return -EINVAL;
 156        }
 157
 158        c->check_lpt_free = c->big_lpt;
 159        return 0;
 160}
 161
 162/**
 163 * calc_dflt_lpt_geom - calculate default LPT geometry.
 164 * @c: the UBIFS file-system description object
 165 * @main_lebs: number of main area LEBs is passed and returned here
 166 * @big_lpt: whether the LPT area is "big" is returned here
 167 *
 168 * The size of the LPT area depends on parameters that themselves are dependent
 169 * on the size of the LPT area. This function, successively recalculates the LPT
 170 * area geometry until the parameters and resultant geometry are consistent.
 171 *
 172 * This function returns %0 on success and a negative error code on failure.
 173 */
 174static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
 175                              int *big_lpt)
 176{
 177        int i, lebs_needed;
 178        long long sz;
 179
 180        /* Start by assuming the minimum number of LPT LEBs */
 181        c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
 182        c->main_lebs = *main_lebs - c->lpt_lebs;
 183        if (c->main_lebs <= 0)
 184                return -EINVAL;
 185
 186        /* And assume we will use the small LPT model */
 187        c->big_lpt = 0;
 188
 189        /*
 190         * Calculate the geometry based on assumptions above and then see if it
 191         * makes sense
 192         */
 193        do_calc_lpt_geom(c);
 194
 195        /* Small LPT model must have lpt_sz < leb_size */
 196        if (c->lpt_sz > c->leb_size) {
 197                /* Nope, so try again using big LPT model */
 198                c->big_lpt = 1;
 199                do_calc_lpt_geom(c);
 200        }
 201
 202        /* Now check there are enough LPT LEBs */
 203        for (i = 0; i < 64 ; i++) {
 204                sz = c->lpt_sz * 4; /* Allow 4 times the size */
 205                lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
 206                if (lebs_needed > c->lpt_lebs) {
 207                        /* Not enough LPT LEBs so try again with more */
 208                        c->lpt_lebs = lebs_needed;
 209                        c->main_lebs = *main_lebs - c->lpt_lebs;
 210                        if (c->main_lebs <= 0)
 211                                return -EINVAL;
 212                        do_calc_lpt_geom(c);
 213                        continue;
 214                }
 215                if (c->ltab_sz > c->leb_size) {
 216                        ubifs_err("LPT ltab too big");
 217                        return -EINVAL;
 218                }
 219                *main_lebs = c->main_lebs;
 220                *big_lpt = c->big_lpt;
 221                return 0;
 222        }
 223        return -EINVAL;
 224}
 225
 226/**
 227 * pack_bits - pack bit fields end-to-end.
 228 * @addr: address at which to pack (passed and next address returned)
 229 * @pos: bit position at which to pack (passed and next position returned)
 230 * @val: value to pack
 231 * @nrbits: number of bits of value to pack (1-32)
 232 */
 233static void pack_bits(uint8_t **addr, int *pos, uint32_t val, int nrbits)
 234{
 235        uint8_t *p = *addr;
 236        int b = *pos;
 237
 238        ubifs_assert(nrbits > 0);
 239        ubifs_assert(nrbits <= 32);
 240        ubifs_assert(*pos >= 0);
 241        ubifs_assert(*pos < 8);
 242        ubifs_assert((val >> nrbits) == 0 || nrbits == 32);
 243        if (b) {
 244                *p |= ((uint8_t)val) << b;
 245                nrbits += b;
 246                if (nrbits > 8) {
 247                        *++p = (uint8_t)(val >>= (8 - b));
 248                        if (nrbits > 16) {
 249                                *++p = (uint8_t)(val >>= 8);
 250                                if (nrbits > 24) {
 251                                        *++p = (uint8_t)(val >>= 8);
 252                                        if (nrbits > 32)
 253                                                *++p = (uint8_t)(val >>= 8);
 254                                }
 255                        }
 256                }
 257        } else {
 258                *p = (uint8_t)val;
 259                if (nrbits > 8) {
 260                        *++p = (uint8_t)(val >>= 8);
 261                        if (nrbits > 16) {
 262                                *++p = (uint8_t)(val >>= 8);
 263                                if (nrbits > 24)
 264                                        *++p = (uint8_t)(val >>= 8);
 265                        }
 266                }
 267        }
 268        b = nrbits & 7;
 269        if (b == 0)
 270                p++;
 271        *addr = p;
 272        *pos = b;
 273}
 274
 275/**
 276 * ubifs_unpack_bits - unpack bit fields.
 277 * @addr: address at which to unpack (passed and next address returned)
 278 * @pos: bit position at which to unpack (passed and next position returned)
 279 * @nrbits: number of bits of value to unpack (1-32)
 280 *
 281 * This functions returns the value unpacked.
 282 */
 283uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
 284{
 285        const int k = 32 - nrbits;
 286        uint8_t *p = *addr;
 287        int b = *pos;
 288        uint32_t uninitialized_var(val);
 289        const int bytes = (nrbits + b + 7) >> 3;
 290
 291        ubifs_assert(nrbits > 0);
 292        ubifs_assert(nrbits <= 32);
 293        ubifs_assert(*pos >= 0);
 294        ubifs_assert(*pos < 8);
 295        if (b) {
 296                switch (bytes) {
 297                case 2:
 298                        val = p[1];
 299                        break;
 300                case 3:
 301                        val = p[1] | ((uint32_t)p[2] << 8);
 302                        break;
 303                case 4:
 304                        val = p[1] | ((uint32_t)p[2] << 8) |
 305                                     ((uint32_t)p[3] << 16);
 306                        break;
 307                case 5:
 308                        val = p[1] | ((uint32_t)p[2] << 8) |
 309                                     ((uint32_t)p[3] << 16) |
 310                                     ((uint32_t)p[4] << 24);
 311                }
 312                val <<= (8 - b);
 313                val |= *p >> b;
 314                nrbits += b;
 315        } else {
 316                switch (bytes) {
 317                case 1:
 318                        val = p[0];
 319                        break;
 320                case 2:
 321                        val = p[0] | ((uint32_t)p[1] << 8);
 322                        break;
 323                case 3:
 324                        val = p[0] | ((uint32_t)p[1] << 8) |
 325                                     ((uint32_t)p[2] << 16);
 326                        break;
 327                case 4:
 328                        val = p[0] | ((uint32_t)p[1] << 8) |
 329                                     ((uint32_t)p[2] << 16) |
 330                                     ((uint32_t)p[3] << 24);
 331                        break;
 332                }
 333        }
 334        val <<= k;
 335        val >>= k;
 336        b = nrbits & 7;
 337        p += nrbits >> 3;
 338        *addr = p;
 339        *pos = b;
 340        ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
 341        return val;
 342}
 343
 344/**
 345 * ubifs_pack_pnode - pack all the bit fields of a pnode.
 346 * @c: UBIFS file-system description object
 347 * @buf: buffer into which to pack
 348 * @pnode: pnode to pack
 349 */
 350void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
 351                      struct ubifs_pnode *pnode)
 352{
 353        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
 354        int i, pos = 0;
 355        uint16_t crc;
 356
 357        pack_bits(&addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
 358        if (c->big_lpt)
 359                pack_bits(&addr, &pos, pnode->num, c->pcnt_bits);
 360        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 361                pack_bits(&addr, &pos, pnode->lprops[i].free >> 3,
 362                          c->space_bits);
 363                pack_bits(&addr, &pos, pnode->lprops[i].dirty >> 3,
 364                          c->space_bits);
 365                if (pnode->lprops[i].flags & LPROPS_INDEX)
 366                        pack_bits(&addr, &pos, 1, 1);
 367                else
 368                        pack_bits(&addr, &pos, 0, 1);
 369        }
 370        crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
 371                    c->pnode_sz - UBIFS_LPT_CRC_BYTES);
 372        addr = buf;
 373        pos = 0;
 374        pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
 375}
 376
 377/**
 378 * ubifs_pack_nnode - pack all the bit fields of a nnode.
 379 * @c: UBIFS file-system description object
 380 * @buf: buffer into which to pack
 381 * @nnode: nnode to pack
 382 */
 383void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
 384                      struct ubifs_nnode *nnode)
 385{
 386        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
 387        int i, pos = 0;
 388        uint16_t crc;
 389
 390        pack_bits(&addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
 391        if (c->big_lpt)
 392                pack_bits(&addr, &pos, nnode->num, c->pcnt_bits);
 393        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 394                int lnum = nnode->nbranch[i].lnum;
 395
 396                if (lnum == 0)
 397                        lnum = c->lpt_last + 1;
 398                pack_bits(&addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
 399                pack_bits(&addr, &pos, nnode->nbranch[i].offs,
 400                          c->lpt_offs_bits);
 401        }
 402        crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
 403                    c->nnode_sz - UBIFS_LPT_CRC_BYTES);
 404        addr = buf;
 405        pos = 0;
 406        pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
 407}
 408
 409/**
 410 * ubifs_pack_ltab - pack the LPT's own lprops table.
 411 * @c: UBIFS file-system description object
 412 * @buf: buffer into which to pack
 413 * @ltab: LPT's own lprops table to pack
 414 */
 415void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
 416                     struct ubifs_lpt_lprops *ltab)
 417{
 418        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
 419        int i, pos = 0;
 420        uint16_t crc;
 421
 422        pack_bits(&addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
 423        for (i = 0; i < c->lpt_lebs; i++) {
 424                pack_bits(&addr, &pos, ltab[i].free, c->lpt_spc_bits);
 425                pack_bits(&addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
 426        }
 427        crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
 428                    c->ltab_sz - UBIFS_LPT_CRC_BYTES);
 429        addr = buf;
 430        pos = 0;
 431        pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
 432}
 433
 434/**
 435 * ubifs_pack_lsave - pack the LPT's save table.
 436 * @c: UBIFS file-system description object
 437 * @buf: buffer into which to pack
 438 * @lsave: LPT's save table to pack
 439 */
 440void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
 441{
 442        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
 443        int i, pos = 0;
 444        uint16_t crc;
 445
 446        pack_bits(&addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
 447        for (i = 0; i < c->lsave_cnt; i++)
 448                pack_bits(&addr, &pos, lsave[i], c->lnum_bits);
 449        crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
 450                    c->lsave_sz - UBIFS_LPT_CRC_BYTES);
 451        addr = buf;
 452        pos = 0;
 453        pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
 454}
 455
 456/**
 457 * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
 458 * @c: UBIFS file-system description object
 459 * @lnum: LEB number to which to add dirty space
 460 * @dirty: amount of dirty space to add
 461 */
 462void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
 463{
 464        if (!dirty || !lnum)
 465                return;
 466        dbg_lp("LEB %d add %d to %d",
 467               lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
 468        ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
 469        c->ltab[lnum - c->lpt_first].dirty += dirty;
 470}
 471
 472/**
 473 * set_ltab - set LPT LEB properties.
 474 * @c: UBIFS file-system description object
 475 * @lnum: LEB number
 476 * @free: amount of free space
 477 * @dirty: amount of dirty space
 478 */
 479static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
 480{
 481        dbg_lp("LEB %d free %d dirty %d to %d %d",
 482               lnum, c->ltab[lnum - c->lpt_first].free,
 483               c->ltab[lnum - c->lpt_first].dirty, free, dirty);
 484        ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
 485        c->ltab[lnum - c->lpt_first].free = free;
 486        c->ltab[lnum - c->lpt_first].dirty = dirty;
 487}
 488
 489/**
 490 * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
 491 * @c: UBIFS file-system description object
 492 * @nnode: nnode for which to add dirt
 493 */
 494void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
 495{
 496        struct ubifs_nnode *np = nnode->parent;
 497
 498        if (np)
 499                ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
 500                                   c->nnode_sz);
 501        else {
 502                ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
 503                if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
 504                        c->lpt_drty_flgs |= LTAB_DIRTY;
 505                        ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
 506                }
 507        }
 508}
 509
 510/**
 511 * add_pnode_dirt - add dirty space to LPT LEB properties.
 512 * @c: UBIFS file-system description object
 513 * @pnode: pnode for which to add dirt
 514 */
 515static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
 516{
 517        ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
 518                           c->pnode_sz);
 519}
 520
 521/**
 522 * calc_nnode_num - calculate nnode number.
 523 * @row: the row in the tree (root is zero)
 524 * @col: the column in the row (leftmost is zero)
 525 *
 526 * The nnode number is a number that uniquely identifies a nnode and can be used
 527 * easily to traverse the tree from the root to that nnode.
 528 *
 529 * This function calculates and returns the nnode number for the nnode at @row
 530 * and @col.
 531 */
 532static int calc_nnode_num(int row, int col)
 533{
 534        int num, bits;
 535
 536        num = 1;
 537        while (row--) {
 538                bits = (col & (UBIFS_LPT_FANOUT - 1));
 539                col >>= UBIFS_LPT_FANOUT_SHIFT;
 540                num <<= UBIFS_LPT_FANOUT_SHIFT;
 541                num |= bits;
 542        }
 543        return num;
 544}
 545
 546/**
 547 * calc_nnode_num_from_parent - calculate nnode number.
 548 * @c: UBIFS file-system description object
 549 * @parent: parent nnode
 550 * @iip: index in parent
 551 *
 552 * The nnode number is a number that uniquely identifies a nnode and can be used
 553 * easily to traverse the tree from the root to that nnode.
 554 *
 555 * This function calculates and returns the nnode number based on the parent's
 556 * nnode number and the index in parent.
 557 */
 558static int calc_nnode_num_from_parent(const struct ubifs_info *c,
 559                                      struct ubifs_nnode *parent, int iip)
 560{
 561        int num, shft;
 562
 563        if (!parent)
 564                return 1;
 565        shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
 566        num = parent->num ^ (1 << shft);
 567        num |= (UBIFS_LPT_FANOUT + iip) << shft;
 568        return num;
 569}
 570
 571/**
 572 * calc_pnode_num_from_parent - calculate pnode number.
 573 * @c: UBIFS file-system description object
 574 * @parent: parent nnode
 575 * @iip: index in parent
 576 *
 577 * The pnode number is a number that uniquely identifies a pnode and can be used
 578 * easily to traverse the tree from the root to that pnode.
 579 *
 580 * This function calculates and returns the pnode number based on the parent's
 581 * nnode number and the index in parent.
 582 */
 583static int calc_pnode_num_from_parent(const struct ubifs_info *c,
 584                                      struct ubifs_nnode *parent, int iip)
 585{
 586        int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
 587
 588        for (i = 0; i < n; i++) {
 589                num <<= UBIFS_LPT_FANOUT_SHIFT;
 590                num |= pnum & (UBIFS_LPT_FANOUT - 1);
 591                pnum >>= UBIFS_LPT_FANOUT_SHIFT;
 592        }
 593        num <<= UBIFS_LPT_FANOUT_SHIFT;
 594        num |= iip;
 595        return num;
 596}
 597
 598/**
 599 * ubifs_create_dflt_lpt - create default LPT.
 600 * @c: UBIFS file-system description object
 601 * @main_lebs: number of main area LEBs is passed and returned here
 602 * @lpt_first: LEB number of first LPT LEB
 603 * @lpt_lebs: number of LEBs for LPT is passed and returned here
 604 * @big_lpt: use big LPT model is passed and returned here
 605 *
 606 * This function returns %0 on success and a negative error code on failure.
 607 */
 608int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
 609                          int *lpt_lebs, int *big_lpt)
 610{
 611        int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
 612        int blnum, boffs, bsz, bcnt;
 613        struct ubifs_pnode *pnode = NULL;
 614        struct ubifs_nnode *nnode = NULL;
 615        void *buf = NULL, *p;
 616        struct ubifs_lpt_lprops *ltab = NULL;
 617        int *lsave = NULL;
 618
 619        err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
 620        if (err)
 621                return err;
 622        *lpt_lebs = c->lpt_lebs;
 623
 624        /* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
 625        c->lpt_first = lpt_first;
 626        /* Needed by 'set_ltab()' */
 627        c->lpt_last = lpt_first + c->lpt_lebs - 1;
 628        /* Needed by 'ubifs_pack_lsave()' */
 629        c->main_first = c->leb_cnt - *main_lebs;
 630
 631        lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_KERNEL);
 632        pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
 633        nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
 634        buf = vmalloc(c->leb_size);
 635        ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
 636        if (!pnode || !nnode || !buf || !ltab || !lsave) {
 637                err = -ENOMEM;
 638                goto out;
 639        }
 640
 641        ubifs_assert(!c->ltab);
 642        c->ltab = ltab; /* Needed by set_ltab */
 643
 644        /* Initialize LPT's own lprops */
 645        for (i = 0; i < c->lpt_lebs; i++) {
 646                ltab[i].free = c->leb_size;
 647                ltab[i].dirty = 0;
 648                ltab[i].tgc = 0;
 649                ltab[i].cmt = 0;
 650        }
 651
 652        lnum = lpt_first;
 653        p = buf;
 654        /* Number of leaf nodes (pnodes) */
 655        cnt = c->pnode_cnt;
 656
 657        /*
 658         * The first pnode contains the LEB properties for the LEBs that contain
 659         * the root inode node and the root index node of the index tree.
 660         */
 661        node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
 662        iopos = ALIGN(node_sz, c->min_io_size);
 663        pnode->lprops[0].free = c->leb_size - iopos;
 664        pnode->lprops[0].dirty = iopos - node_sz;
 665        pnode->lprops[0].flags = LPROPS_INDEX;
 666
 667        node_sz = UBIFS_INO_NODE_SZ;
 668        iopos = ALIGN(node_sz, c->min_io_size);
 669        pnode->lprops[1].free = c->leb_size - iopos;
 670        pnode->lprops[1].dirty = iopos - node_sz;
 671
 672        for (i = 2; i < UBIFS_LPT_FANOUT; i++)
 673                pnode->lprops[i].free = c->leb_size;
 674
 675        /* Add first pnode */
 676        ubifs_pack_pnode(c, p, pnode);
 677        p += c->pnode_sz;
 678        len = c->pnode_sz;
 679        pnode->num += 1;
 680
 681        /* Reset pnode values for remaining pnodes */
 682        pnode->lprops[0].free = c->leb_size;
 683        pnode->lprops[0].dirty = 0;
 684        pnode->lprops[0].flags = 0;
 685
 686        pnode->lprops[1].free = c->leb_size;
 687        pnode->lprops[1].dirty = 0;
 688
 689        /*
 690         * To calculate the internal node branches, we keep information about
 691         * the level below.
 692         */
 693        blnum = lnum; /* LEB number of level below */
 694        boffs = 0; /* Offset of level below */
 695        bcnt = cnt; /* Number of nodes in level below */
 696        bsz = c->pnode_sz; /* Size of nodes in level below */
 697
 698        /* Add all remaining pnodes */
 699        for (i = 1; i < cnt; i++) {
 700                if (len + c->pnode_sz > c->leb_size) {
 701                        alen = ALIGN(len, c->min_io_size);
 702                        set_ltab(c, lnum, c->leb_size - alen, alen - len);
 703                        memset(p, 0xff, alen - len);
 704                        err = ubifs_leb_change(c, lnum++, buf, alen);
 705                        if (err)
 706                                goto out;
 707                        p = buf;
 708                        len = 0;
 709                }
 710                ubifs_pack_pnode(c, p, pnode);
 711                p += c->pnode_sz;
 712                len += c->pnode_sz;
 713                /*
 714                 * pnodes are simply numbered left to right starting at zero,
 715                 * which means the pnode number can be used easily to traverse
 716                 * down the tree to the corresponding pnode.
 717                 */
 718                pnode->num += 1;
 719        }
 720
 721        row = 0;
 722        for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
 723                row += 1;
 724        /* Add all nnodes, one level at a time */
 725        while (1) {
 726                /* Number of internal nodes (nnodes) at next level */
 727                cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
 728                for (i = 0; i < cnt; i++) {
 729                        if (len + c->nnode_sz > c->leb_size) {
 730                                alen = ALIGN(len, c->min_io_size);
 731                                set_ltab(c, lnum, c->leb_size - alen,
 732                                            alen - len);
 733                                memset(p, 0xff, alen - len);
 734                                err = ubifs_leb_change(c, lnum++, buf, alen);
 735                                if (err)
 736                                        goto out;
 737                                p = buf;
 738                                len = 0;
 739                        }
 740                        /* Only 1 nnode at this level, so it is the root */
 741                        if (cnt == 1) {
 742                                c->lpt_lnum = lnum;
 743                                c->lpt_offs = len;
 744                        }
 745                        /* Set branches to the level below */
 746                        for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
 747                                if (bcnt) {
 748                                        if (boffs + bsz > c->leb_size) {
 749                                                blnum += 1;
 750                                                boffs = 0;
 751                                        }
 752                                        nnode->nbranch[j].lnum = blnum;
 753                                        nnode->nbranch[j].offs = boffs;
 754                                        boffs += bsz;
 755                                        bcnt--;
 756                                } else {
 757                                        nnode->nbranch[j].lnum = 0;
 758                                        nnode->nbranch[j].offs = 0;
 759                                }
 760                        }
 761                        nnode->num = calc_nnode_num(row, i);
 762                        ubifs_pack_nnode(c, p, nnode);
 763                        p += c->nnode_sz;
 764                        len += c->nnode_sz;
 765                }
 766                /* Only 1 nnode at this level, so it is the root */
 767                if (cnt == 1)
 768                        break;
 769                /* Update the information about the level below */
 770                bcnt = cnt;
 771                bsz = c->nnode_sz;
 772                row -= 1;
 773        }
 774
 775        if (*big_lpt) {
 776                /* Need to add LPT's save table */
 777                if (len + c->lsave_sz > c->leb_size) {
 778                        alen = ALIGN(len, c->min_io_size);
 779                        set_ltab(c, lnum, c->leb_size - alen, alen - len);
 780                        memset(p, 0xff, alen - len);
 781                        err = ubifs_leb_change(c, lnum++, buf, alen);
 782                        if (err)
 783                                goto out;
 784                        p = buf;
 785                        len = 0;
 786                }
 787
 788                c->lsave_lnum = lnum;
 789                c->lsave_offs = len;
 790
 791                for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
 792                        lsave[i] = c->main_first + i;
 793                for (; i < c->lsave_cnt; i++)
 794                        lsave[i] = c->main_first;
 795
 796                ubifs_pack_lsave(c, p, lsave);
 797                p += c->lsave_sz;
 798                len += c->lsave_sz;
 799        }
 800
 801        /* Need to add LPT's own LEB properties table */
 802        if (len + c->ltab_sz > c->leb_size) {
 803                alen = ALIGN(len, c->min_io_size);
 804                set_ltab(c, lnum, c->leb_size - alen, alen - len);
 805                memset(p, 0xff, alen - len);
 806                err = ubifs_leb_change(c, lnum++, buf, alen);
 807                if (err)
 808                        goto out;
 809                p = buf;
 810                len = 0;
 811        }
 812
 813        c->ltab_lnum = lnum;
 814        c->ltab_offs = len;
 815
 816        /* Update ltab before packing it */
 817        len += c->ltab_sz;
 818        alen = ALIGN(len, c->min_io_size);
 819        set_ltab(c, lnum, c->leb_size - alen, alen - len);
 820
 821        ubifs_pack_ltab(c, p, ltab);
 822        p += c->ltab_sz;
 823
 824        /* Write remaining buffer */
 825        memset(p, 0xff, alen - len);
 826        err = ubifs_leb_change(c, lnum, buf, alen);
 827        if (err)
 828                goto out;
 829
 830        c->nhead_lnum = lnum;
 831        c->nhead_offs = ALIGN(len, c->min_io_size);
 832
 833        dbg_lp("space_bits %d", c->space_bits);
 834        dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
 835        dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
 836        dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
 837        dbg_lp("pcnt_bits %d", c->pcnt_bits);
 838        dbg_lp("lnum_bits %d", c->lnum_bits);
 839        dbg_lp("pnode_sz %d", c->pnode_sz);
 840        dbg_lp("nnode_sz %d", c->nnode_sz);
 841        dbg_lp("ltab_sz %d", c->ltab_sz);
 842        dbg_lp("lsave_sz %d", c->lsave_sz);
 843        dbg_lp("lsave_cnt %d", c->lsave_cnt);
 844        dbg_lp("lpt_hght %d", c->lpt_hght);
 845        dbg_lp("big_lpt %d", c->big_lpt);
 846        dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
 847        dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
 848        dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
 849        if (c->big_lpt)
 850                dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
 851out:
 852        c->ltab = NULL;
 853        kfree(lsave);
 854        vfree(ltab);
 855        vfree(buf);
 856        kfree(nnode);
 857        kfree(pnode);
 858        return err;
 859}
 860
 861/**
 862 * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
 863 * @c: UBIFS file-system description object
 864 * @pnode: pnode
 865 *
 866 * When a pnode is loaded into memory, the LEB properties it contains are added,
 867 * by this function, to the LEB category lists and heaps.
 868 */
 869static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
 870{
 871        int i;
 872
 873        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 874                int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
 875                int lnum = pnode->lprops[i].lnum;
 876
 877                if (!lnum)
 878                        return;
 879                ubifs_add_to_cat(c, &pnode->lprops[i], cat);
 880        }
 881}
 882
 883/**
 884 * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
 885 * @c: UBIFS file-system description object
 886 * @old_pnode: pnode copied
 887 * @new_pnode: pnode copy
 888 *
 889 * During commit it is sometimes necessary to copy a pnode
 890 * (see dirty_cow_pnode).  When that happens, references in
 891 * category lists and heaps must be replaced.  This function does that.
 892 */
 893static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
 894                         struct ubifs_pnode *new_pnode)
 895{
 896        int i;
 897
 898        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 899                if (!new_pnode->lprops[i].lnum)
 900                        return;
 901                ubifs_replace_cat(c, &old_pnode->lprops[i],
 902                                  &new_pnode->lprops[i]);
 903        }
 904}
 905
 906/**
 907 * check_lpt_crc - check LPT node crc is correct.
 908 * @c: UBIFS file-system description object
 909 * @buf: buffer containing node
 910 * @len: length of node
 911 *
 912 * This function returns %0 on success and a negative error code on failure.
 913 */
 914static int check_lpt_crc(void *buf, int len)
 915{
 916        int pos = 0;
 917        uint8_t *addr = buf;
 918        uint16_t crc, calc_crc;
 919
 920        crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
 921        calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
 922                         len - UBIFS_LPT_CRC_BYTES);
 923        if (crc != calc_crc) {
 924                ubifs_err("invalid crc in LPT node: crc %hx calc %hx", crc,
 925                          calc_crc);
 926                dump_stack();
 927                return -EINVAL;
 928        }
 929        return 0;
 930}
 931
 932/**
 933 * check_lpt_type - check LPT node type is correct.
 934 * @c: UBIFS file-system description object
 935 * @addr: address of type bit field is passed and returned updated here
 936 * @pos: position of type bit field is passed and returned updated here
 937 * @type: expected type
 938 *
 939 * This function returns %0 on success and a negative error code on failure.
 940 */
 941static int check_lpt_type(uint8_t **addr, int *pos, int type)
 942{
 943        int node_type;
 944
 945        node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
 946        if (node_type != type) {
 947                ubifs_err("invalid type (%d) in LPT node type %d", node_type,
 948                          type);
 949                dump_stack();
 950                return -EINVAL;
 951        }
 952        return 0;
 953}
 954
 955/**
 956 * unpack_pnode - unpack a pnode.
 957 * @c: UBIFS file-system description object
 958 * @buf: buffer containing packed pnode to unpack
 959 * @pnode: pnode structure to fill
 960 *
 961 * This function returns %0 on success and a negative error code on failure.
 962 */
 963static int unpack_pnode(const struct ubifs_info *c, void *buf,
 964                        struct ubifs_pnode *pnode)
 965{
 966        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
 967        int i, pos = 0, err;
 968
 969        err = check_lpt_type(&addr, &pos, UBIFS_LPT_PNODE);
 970        if (err)
 971                return err;
 972        if (c->big_lpt)
 973                pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
 974        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 975                struct ubifs_lprops * const lprops = &pnode->lprops[i];
 976
 977                lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
 978                lprops->free <<= 3;
 979                lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
 980                lprops->dirty <<= 3;
 981
 982                if (ubifs_unpack_bits(&addr, &pos, 1))
 983                        lprops->flags = LPROPS_INDEX;
 984                else
 985                        lprops->flags = 0;
 986                lprops->flags |= ubifs_categorize_lprops(c, lprops);
 987        }
 988        err = check_lpt_crc(buf, c->pnode_sz);
 989        return err;
 990}
 991
 992/**
 993 * ubifs_unpack_nnode - unpack a nnode.
 994 * @c: UBIFS file-system description object
 995 * @buf: buffer containing packed nnode to unpack
 996 * @nnode: nnode structure to fill
 997 *
 998 * This function returns %0 on success and a negative error code on failure.
 999 */
1000int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
1001                       struct ubifs_nnode *nnode)
1002{
1003        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1004        int i, pos = 0, err;
1005
1006        err = check_lpt_type(&addr, &pos, UBIFS_LPT_NNODE);
1007        if (err)
1008                return err;
1009        if (c->big_lpt)
1010                nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1011        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1012                int lnum;
1013
1014                lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
1015                       c->lpt_first;
1016                if (lnum == c->lpt_last + 1)
1017                        lnum = 0;
1018                nnode->nbranch[i].lnum = lnum;
1019                nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
1020                                                     c->lpt_offs_bits);
1021        }
1022        err = check_lpt_crc(buf, c->nnode_sz);
1023        return err;
1024}
1025
1026/**
1027 * unpack_ltab - unpack the LPT's own lprops table.
1028 * @c: UBIFS file-system description object
1029 * @buf: buffer from which to unpack
1030 *
1031 * This function returns %0 on success and a negative error code on failure.
1032 */
1033static int unpack_ltab(const struct ubifs_info *c, void *buf)
1034{
1035        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1036        int i, pos = 0, err;
1037
1038        err = check_lpt_type(&addr, &pos, UBIFS_LPT_LTAB);
1039        if (err)
1040                return err;
1041        for (i = 0; i < c->lpt_lebs; i++) {
1042                int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1043                int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1044
1045                if (free < 0 || free > c->leb_size || dirty < 0 ||
1046                    dirty > c->leb_size || free + dirty > c->leb_size)
1047                        return -EINVAL;
1048
1049                c->ltab[i].free = free;
1050                c->ltab[i].dirty = dirty;
1051                c->ltab[i].tgc = 0;
1052                c->ltab[i].cmt = 0;
1053        }
1054        err = check_lpt_crc(buf, c->ltab_sz);
1055        return err;
1056}
1057
1058/**
1059 * unpack_lsave - unpack the LPT's save table.
1060 * @c: UBIFS file-system description object
1061 * @buf: buffer from which to unpack
1062 *
1063 * This function returns %0 on success and a negative error code on failure.
1064 */
1065static int unpack_lsave(const struct ubifs_info *c, void *buf)
1066{
1067        uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1068        int i, pos = 0, err;
1069
1070        err = check_lpt_type(&addr, &pos, UBIFS_LPT_LSAVE);
1071        if (err)
1072                return err;
1073        for (i = 0; i < c->lsave_cnt; i++) {
1074                int lnum = ubifs_unpack_bits(&addr, &pos, c->lnum_bits);
1075
1076                if (lnum < c->main_first || lnum >= c->leb_cnt)
1077                        return -EINVAL;
1078                c->lsave[i] = lnum;
1079        }
1080        err = check_lpt_crc(buf, c->lsave_sz);
1081        return err;
1082}
1083
1084/**
1085 * validate_nnode - validate a nnode.
1086 * @c: UBIFS file-system description object
1087 * @nnode: nnode to validate
1088 * @parent: parent nnode (or NULL for the root nnode)
1089 * @iip: index in parent
1090 *
1091 * This function returns %0 on success and a negative error code on failure.
1092 */
1093static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
1094                          struct ubifs_nnode *parent, int iip)
1095{
1096        int i, lvl, max_offs;
1097
1098        if (c->big_lpt) {
1099                int num = calc_nnode_num_from_parent(c, parent, iip);
1100
1101                if (nnode->num != num)
1102                        return -EINVAL;
1103        }
1104        lvl = parent ? parent->level - 1 : c->lpt_hght;
1105        if (lvl < 1)
1106                return -EINVAL;
1107        if (lvl == 1)
1108                max_offs = c->leb_size - c->pnode_sz;
1109        else
1110                max_offs = c->leb_size - c->nnode_sz;
1111        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1112                int lnum = nnode->nbranch[i].lnum;
1113                int offs = nnode->nbranch[i].offs;
1114
1115                if (lnum == 0) {
1116                        if (offs != 0)
1117                                return -EINVAL;
1118                        continue;
1119                }
1120                if (lnum < c->lpt_first || lnum > c->lpt_last)
1121                        return -EINVAL;
1122                if (offs < 0 || offs > max_offs)
1123                        return -EINVAL;
1124        }
1125        return 0;
1126}
1127
1128/**
1129 * validate_pnode - validate a pnode.
1130 * @c: UBIFS file-system description object
1131 * @pnode: pnode to validate
1132 * @parent: parent nnode
1133 * @iip: index in parent
1134 *
1135 * This function returns %0 on success and a negative error code on failure.
1136 */
1137static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
1138                          struct ubifs_nnode *parent, int iip)
1139{
1140        int i;
1141
1142        if (c->big_lpt) {
1143                int num = calc_pnode_num_from_parent(c, parent, iip);
1144
1145                if (pnode->num != num)
1146                        return -EINVAL;
1147        }
1148        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1149                int free = pnode->lprops[i].free;
1150                int dirty = pnode->lprops[i].dirty;
1151
1152                if (free < 0 || free > c->leb_size || free % c->min_io_size ||
1153                    (free & 7))
1154                        return -EINVAL;
1155                if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
1156                        return -EINVAL;
1157                if (dirty + free > c->leb_size)
1158                        return -EINVAL;
1159        }
1160        return 0;
1161}
1162
1163/**
1164 * set_pnode_lnum - set LEB numbers on a pnode.
1165 * @c: UBIFS file-system description object
1166 * @pnode: pnode to update
1167 *
1168 * This function calculates the LEB numbers for the LEB properties it contains
1169 * based on the pnode number.
1170 */
1171static void set_pnode_lnum(const struct ubifs_info *c,
1172                           struct ubifs_pnode *pnode)
1173{
1174        int i, lnum;
1175
1176        lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
1177        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1178                if (lnum >= c->leb_cnt)
1179                        return;
1180                pnode->lprops[i].lnum = lnum++;
1181        }
1182}
1183
1184/**
1185 * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
1186 * @c: UBIFS file-system description object
1187 * @parent: parent nnode (or NULL for the root)
1188 * @iip: index in parent
1189 *
1190 * This function returns %0 on success and a negative error code on failure.
1191 */
1192int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1193{
1194        struct ubifs_nbranch *branch = NULL;
1195        struct ubifs_nnode *nnode = NULL;
1196        void *buf = c->lpt_nod_buf;
1197        int err, lnum, offs;
1198
1199        if (parent) {
1200                branch = &parent->nbranch[iip];
1201                lnum = branch->lnum;
1202                offs = branch->offs;
1203        } else {
1204                lnum = c->lpt_lnum;
1205                offs = c->lpt_offs;
1206        }
1207        nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1208        if (!nnode) {
1209                err = -ENOMEM;
1210                goto out;
1211        }
1212        if (lnum == 0) {
1213                /*
1214                 * This nnode was not written which just means that the LEB
1215                 * properties in the subtree below it describe empty LEBs. We
1216                 * make the nnode as though we had read it, which in fact means
1217                 * doing almost nothing.
1218                 */
1219                if (c->big_lpt)
1220                        nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1221        } else {
1222                err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1);
1223                if (err)
1224                        goto out;
1225                err = ubifs_unpack_nnode(c, buf, nnode);
1226                if (err)
1227                        goto out;
1228        }
1229        err = validate_nnode(c, nnode, parent, iip);
1230        if (err)
1231                goto out;
1232        if (!c->big_lpt)
1233                nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1234        if (parent) {
1235                branch->nnode = nnode;
1236                nnode->level = parent->level - 1;
1237        } else {
1238                c->nroot = nnode;
1239                nnode->level = c->lpt_hght;
1240        }
1241        nnode->parent = parent;
1242        nnode->iip = iip;
1243        return 0;
1244
1245out:
1246        ubifs_err("error %d reading nnode at %d:%d", err, lnum, offs);
1247        dump_stack();
1248        kfree(nnode);
1249        return err;
1250}
1251
1252/**
1253 * read_pnode - read a pnode from flash and link it to the tree in memory.
1254 * @c: UBIFS file-system description object
1255 * @parent: parent nnode
1256 * @iip: index in parent
1257 *
1258 * This function returns %0 on success and a negative error code on failure.
1259 */
1260static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1261{
1262        struct ubifs_nbranch *branch;
1263        struct ubifs_pnode *pnode = NULL;
1264        void *buf = c->lpt_nod_buf;
1265        int err, lnum, offs;
1266
1267        branch = &parent->nbranch[iip];
1268        lnum = branch->lnum;
1269        offs = branch->offs;
1270        pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1271        if (!pnode)
1272                return -ENOMEM;
1273
1274        if (lnum == 0) {
1275                /*
1276                 * This pnode was not written which just means that the LEB
1277                 * properties in it describe empty LEBs. We make the pnode as
1278                 * though we had read it.
1279                 */
1280                int i;
1281
1282                if (c->big_lpt)
1283                        pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1284                for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1285                        struct ubifs_lprops * const lprops = &pnode->lprops[i];
1286
1287                        lprops->free = c->leb_size;
1288                        lprops->flags = ubifs_categorize_lprops(c, lprops);
1289                }
1290        } else {
1291                err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1);
1292                if (err)
1293                        goto out;
1294                err = unpack_pnode(c, buf, pnode);
1295                if (err)
1296                        goto out;
1297        }
1298        err = validate_pnode(c, pnode, parent, iip);
1299        if (err)
1300                goto out;
1301        if (!c->big_lpt)
1302                pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1303        branch->pnode = pnode;
1304        pnode->parent = parent;
1305        pnode->iip = iip;
1306        set_pnode_lnum(c, pnode);
1307        c->pnodes_have += 1;
1308        return 0;
1309
1310out:
1311        ubifs_err("error %d reading pnode at %d:%d", err, lnum, offs);
1312        ubifs_dump_pnode(c, pnode, parent, iip);
1313        dump_stack();
1314        ubifs_err("calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
1315        kfree(pnode);
1316        return err;
1317}
1318
1319/**
1320 * read_ltab - read LPT's own lprops table.
1321 * @c: UBIFS file-system description object
1322 *
1323 * This function returns %0 on success and a negative error code on failure.
1324 */
1325static int read_ltab(struct ubifs_info *c)
1326{
1327        int err;
1328        void *buf;
1329
1330        buf = vmalloc(c->ltab_sz);
1331        if (!buf)
1332                return -ENOMEM;
1333        err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1);
1334        if (err)
1335                goto out;
1336        err = unpack_ltab(c, buf);
1337out:
1338        vfree(buf);
1339        return err;
1340}
1341
1342/**
1343 * read_lsave - read LPT's save table.
1344 * @c: UBIFS file-system description object
1345 *
1346 * This function returns %0 on success and a negative error code on failure.
1347 */
1348static int read_lsave(struct ubifs_info *c)
1349{
1350        int err, i;
1351        void *buf;
1352
1353        buf = vmalloc(c->lsave_sz);
1354        if (!buf)
1355                return -ENOMEM;
1356        err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs,
1357                             c->lsave_sz, 1);
1358        if (err)
1359                goto out;
1360        err = unpack_lsave(c, buf);
1361        if (err)
1362                goto out;
1363        for (i = 0; i < c->lsave_cnt; i++) {
1364                int lnum = c->lsave[i];
1365                struct ubifs_lprops *lprops;
1366
1367                /*
1368                 * Due to automatic resizing, the values in the lsave table
1369                 * could be beyond the volume size - just ignore them.
1370                 */
1371                if (lnum >= c->leb_cnt)
1372                        continue;
1373                lprops = ubifs_lpt_lookup(c, lnum);
1374                if (IS_ERR(lprops)) {
1375                        err = PTR_ERR(lprops);
1376                        goto out;
1377                }
1378        }
1379out:
1380        vfree(buf);
1381        return err;
1382}
1383
1384/**
1385 * ubifs_get_nnode - get a nnode.
1386 * @c: UBIFS file-system description object
1387 * @parent: parent nnode (or NULL for the root)
1388 * @iip: index in parent
1389 *
1390 * This function returns a pointer to the nnode on success or a negative error
1391 * code on failure.
1392 */
1393struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
1394                                    struct ubifs_nnode *parent, int iip)
1395{
1396        struct ubifs_nbranch *branch;
1397        struct ubifs_nnode *nnode;
1398        int err;
1399
1400        branch = &parent->nbranch[iip];
1401        nnode = branch->nnode;
1402        if (nnode)
1403                return nnode;
1404        err = ubifs_read_nnode(c, parent, iip);
1405        if (err)
1406                return ERR_PTR(err);
1407        return branch->nnode;
1408}
1409
1410/**
1411 * ubifs_get_pnode - get a pnode.
1412 * @c: UBIFS file-system description object
1413 * @parent: parent nnode
1414 * @iip: index in parent
1415 *
1416 * This function returns a pointer to the pnode on success or a negative error
1417 * code on failure.
1418 */
1419struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
1420                                    struct ubifs_nnode *parent, int iip)
1421{
1422        struct ubifs_nbranch *branch;
1423        struct ubifs_pnode *pnode;
1424        int err;
1425
1426        branch = &parent->nbranch[iip];
1427        pnode = branch->pnode;
1428        if (pnode)
1429                return pnode;
1430        err = read_pnode(c, parent, iip);
1431        if (err)
1432                return ERR_PTR(err);
1433        update_cats(c, branch->pnode);
1434        return branch->pnode;
1435}
1436
1437/**
1438 * ubifs_lpt_lookup - lookup LEB properties in the LPT.
1439 * @c: UBIFS file-system description object
1440 * @lnum: LEB number to lookup
1441 *
1442 * This function returns a pointer to the LEB properties on success or a
1443 * negative error code on failure.
1444 */
1445struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
1446{
1447        int err, i, h, iip, shft;
1448        struct ubifs_nnode *nnode;
1449        struct ubifs_pnode *pnode;
1450
1451        if (!c->nroot) {
1452                err = ubifs_read_nnode(c, NULL, 0);
1453                if (err)
1454                        return ERR_PTR(err);
1455        }
1456        nnode = c->nroot;
1457        i = lnum - c->main_first;
1458        shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1459        for (h = 1; h < c->lpt_hght; h++) {
1460                iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1461                shft -= UBIFS_LPT_FANOUT_SHIFT;
1462                nnode = ubifs_get_nnode(c, nnode, iip);
1463                if (IS_ERR(nnode))
1464                        return ERR_CAST(nnode);
1465        }
1466        iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1467        shft -= UBIFS_LPT_FANOUT_SHIFT;
1468        pnode = ubifs_get_pnode(c, nnode, iip);
1469        if (IS_ERR(pnode))
1470                return ERR_CAST(pnode);
1471        iip = (i & (UBIFS_LPT_FANOUT - 1));
1472        dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1473               pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1474               pnode->lprops[iip].flags);
1475        return &pnode->lprops[iip];
1476}
1477
1478/**
1479 * dirty_cow_nnode - ensure a nnode is not being committed.
1480 * @c: UBIFS file-system description object
1481 * @nnode: nnode to check
1482 *
1483 * Returns dirtied nnode on success or negative error code on failure.
1484 */
1485static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
1486                                           struct ubifs_nnode *nnode)
1487{
1488        struct ubifs_nnode *n;
1489        int i;
1490
1491        if (!test_bit(COW_CNODE, &nnode->flags)) {
1492                /* nnode is not being committed */
1493                if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
1494                        c->dirty_nn_cnt += 1;
1495                        ubifs_add_nnode_dirt(c, nnode);
1496                }
1497                return nnode;
1498        }
1499
1500        /* nnode is being committed, so copy it */
1501        n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1502        if (unlikely(!n))
1503                return ERR_PTR(-ENOMEM);
1504
1505        memcpy(n, nnode, sizeof(struct ubifs_nnode));
1506        n->cnext = NULL;
1507        __set_bit(DIRTY_CNODE, &n->flags);
1508        __clear_bit(COW_CNODE, &n->flags);
1509
1510        /* The children now have new parent */
1511        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1512                struct ubifs_nbranch *branch = &n->nbranch[i];
1513
1514                if (branch->cnode)
1515                        branch->cnode->parent = n;
1516        }
1517
1518        ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
1519        __set_bit(OBSOLETE_CNODE, &nnode->flags);
1520
1521        c->dirty_nn_cnt += 1;
1522        ubifs_add_nnode_dirt(c, nnode);
1523        if (nnode->parent)
1524                nnode->parent->nbranch[n->iip].nnode = n;
1525        else
1526                c->nroot = n;
1527        return n;
1528}
1529
1530/**
1531 * dirty_cow_pnode - ensure a pnode is not being committed.
1532 * @c: UBIFS file-system description object
1533 * @pnode: pnode to check
1534 *
1535 * Returns dirtied pnode on success or negative error code on failure.
1536 */
1537static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
1538                                           struct ubifs_pnode *pnode)
1539{
1540        struct ubifs_pnode *p;
1541
1542        if (!test_bit(COW_CNODE, &pnode->flags)) {
1543                /* pnode is not being committed */
1544                if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
1545                        c->dirty_pn_cnt += 1;
1546                        add_pnode_dirt(c, pnode);
1547                }
1548                return pnode;
1549        }
1550
1551        /* pnode is being committed, so copy it */
1552        p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1553        if (unlikely(!p))
1554                return ERR_PTR(-ENOMEM);
1555
1556        memcpy(p, pnode, sizeof(struct ubifs_pnode));
1557        p->cnext = NULL;
1558        __set_bit(DIRTY_CNODE, &p->flags);
1559        __clear_bit(COW_CNODE, &p->flags);
1560        replace_cats(c, pnode, p);
1561
1562        ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
1563        __set_bit(OBSOLETE_CNODE, &pnode->flags);
1564
1565        c->dirty_pn_cnt += 1;
1566        add_pnode_dirt(c, pnode);
1567        pnode->parent->nbranch[p->iip].pnode = p;
1568        return p;
1569}
1570
1571/**
1572 * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
1573 * @c: UBIFS file-system description object
1574 * @lnum: LEB number to lookup
1575 *
1576 * This function returns a pointer to the LEB properties on success or a
1577 * negative error code on failure.
1578 */
1579struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
1580{
1581        int err, i, h, iip, shft;
1582        struct ubifs_nnode *nnode;
1583        struct ubifs_pnode *pnode;
1584
1585        if (!c->nroot) {
1586                err = ubifs_read_nnode(c, NULL, 0);
1587                if (err)
1588                        return ERR_PTR(err);
1589        }
1590        nnode = c->nroot;
1591        nnode = dirty_cow_nnode(c, nnode);
1592        if (IS_ERR(nnode))
1593                return ERR_CAST(nnode);
1594        i = lnum - c->main_first;
1595        shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1596        for (h = 1; h < c->lpt_hght; h++) {
1597                iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1598                shft -= UBIFS_LPT_FANOUT_SHIFT;
1599                nnode = ubifs_get_nnode(c, nnode, iip);
1600                if (IS_ERR(nnode))
1601                        return ERR_CAST(nnode);
1602                nnode = dirty_cow_nnode(c, nnode);
1603                if (IS_ERR(nnode))
1604                        return ERR_CAST(nnode);
1605        }
1606        iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1607        shft -= UBIFS_LPT_FANOUT_SHIFT;
1608        pnode = ubifs_get_pnode(c, nnode, iip);
1609        if (IS_ERR(pnode))
1610                return ERR_CAST(pnode);
1611        pnode = dirty_cow_pnode(c, pnode);
1612        if (IS_ERR(pnode))
1613                return ERR_CAST(pnode);
1614        iip = (i & (UBIFS_LPT_FANOUT - 1));
1615        dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1616               pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1617               pnode->lprops[iip].flags);
1618        ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
1619        return &pnode->lprops[iip];
1620}
1621
1622/**
1623 * lpt_init_rd - initialize the LPT for reading.
1624 * @c: UBIFS file-system description object
1625 *
1626 * This function returns %0 on success and a negative error code on failure.
1627 */
1628static int lpt_init_rd(struct ubifs_info *c)
1629{
1630        int err, i;
1631
1632        c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1633        if (!c->ltab)
1634                return -ENOMEM;
1635
1636        i = max_t(int, c->nnode_sz, c->pnode_sz);
1637        c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
1638        if (!c->lpt_nod_buf)
1639                return -ENOMEM;
1640
1641        for (i = 0; i < LPROPS_HEAP_CNT; i++) {
1642                c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
1643                                             GFP_KERNEL);
1644                if (!c->lpt_heap[i].arr)
1645                        return -ENOMEM;
1646                c->lpt_heap[i].cnt = 0;
1647                c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
1648        }
1649
1650        c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
1651        if (!c->dirty_idx.arr)
1652                return -ENOMEM;
1653        c->dirty_idx.cnt = 0;
1654        c->dirty_idx.max_cnt = LPT_HEAP_SZ;
1655
1656        err = read_ltab(c);
1657        if (err)
1658                return err;
1659
1660        dbg_lp("space_bits %d", c->space_bits);
1661        dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
1662        dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
1663        dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
1664        dbg_lp("pcnt_bits %d", c->pcnt_bits);
1665        dbg_lp("lnum_bits %d", c->lnum_bits);
1666        dbg_lp("pnode_sz %d", c->pnode_sz);
1667        dbg_lp("nnode_sz %d", c->nnode_sz);
1668        dbg_lp("ltab_sz %d", c->ltab_sz);
1669        dbg_lp("lsave_sz %d", c->lsave_sz);
1670        dbg_lp("lsave_cnt %d", c->lsave_cnt);
1671        dbg_lp("lpt_hght %d", c->lpt_hght);
1672        dbg_lp("big_lpt %d", c->big_lpt);
1673        dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
1674        dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
1675        dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
1676        if (c->big_lpt)
1677                dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
1678
1679        return 0;
1680}
1681
1682/**
1683 * lpt_init_wr - initialize the LPT for writing.
1684 * @c: UBIFS file-system description object
1685 *
1686 * 'lpt_init_rd()' must have been called already.
1687 *
1688 * This function returns %0 on success and a negative error code on failure.
1689 */
1690static int lpt_init_wr(struct ubifs_info *c)
1691{
1692        int err, i;
1693
1694        c->ltab_cmt = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1695        if (!c->ltab_cmt)
1696                return -ENOMEM;
1697
1698        c->lpt_buf = vmalloc(c->leb_size);
1699        if (!c->lpt_buf)
1700                return -ENOMEM;
1701
1702        if (c->big_lpt) {
1703                c->lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_NOFS);
1704                if (!c->lsave)
1705                        return -ENOMEM;
1706                err = read_lsave(c);
1707                if (err)
1708                        return err;
1709        }
1710
1711        for (i = 0; i < c->lpt_lebs; i++)
1712                if (c->ltab[i].free == c->leb_size) {
1713                        err = ubifs_leb_unmap(c, i + c->lpt_first);
1714                        if (err)
1715                                return err;
1716                }
1717
1718        return 0;
1719}
1720
1721/**
1722 * ubifs_lpt_init - initialize the LPT.
1723 * @c: UBIFS file-system description object
1724 * @rd: whether to initialize lpt for reading
1725 * @wr: whether to initialize lpt for writing
1726 *
1727 * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
1728 * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
1729 * true.
1730 *
1731 * This function returns %0 on success and a negative error code on failure.
1732 */
1733int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
1734{
1735        int err;
1736
1737        if (rd) {
1738                err = lpt_init_rd(c);
1739                if (err)
1740                        goto out_err;
1741        }
1742
1743        if (wr) {
1744                err = lpt_init_wr(c);
1745                if (err)
1746                        goto out_err;
1747        }
1748
1749        return 0;
1750
1751out_err:
1752        if (wr)
1753                ubifs_lpt_free(c, 1);
1754        if (rd)
1755                ubifs_lpt_free(c, 0);
1756        return err;
1757}
1758
1759/**
1760 * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
1761 * @nnode: where to keep a nnode
1762 * @pnode: where to keep a pnode
1763 * @cnode: where to keep a cnode
1764 * @in_tree: is the node in the tree in memory
1765 * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
1766 * the tree
1767 * @ptr.pnode: ditto for pnode
1768 * @ptr.cnode: ditto for cnode
1769 */
1770struct lpt_scan_node {
1771        union {
1772                struct ubifs_nnode nnode;
1773                struct ubifs_pnode pnode;
1774                struct ubifs_cnode cnode;
1775        };
1776        int in_tree;
1777        union {
1778                struct ubifs_nnode *nnode;
1779                struct ubifs_pnode *pnode;
1780                struct ubifs_cnode *cnode;
1781        } ptr;
1782};
1783
1784/**
1785 * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
1786 * @c: the UBIFS file-system description object
1787 * @path: where to put the nnode
1788 * @parent: parent of the nnode
1789 * @iip: index in parent of the nnode
1790 *
1791 * This function returns a pointer to the nnode on success or a negative error
1792 * code on failure.
1793 */
1794static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
1795                                          struct lpt_scan_node *path,
1796                                          struct ubifs_nnode *parent, int iip)
1797{
1798        struct ubifs_nbranch *branch;
1799        struct ubifs_nnode *nnode;
1800        void *buf = c->lpt_nod_buf;
1801        int err;
1802
1803        branch = &parent->nbranch[iip];
1804        nnode = branch->nnode;
1805        if (nnode) {
1806                path->in_tree = 1;
1807                path->ptr.nnode = nnode;
1808                return nnode;
1809        }
1810        nnode = &path->nnode;
1811        path->in_tree = 0;
1812        path->ptr.nnode = nnode;
1813        memset(nnode, 0, sizeof(struct ubifs_nnode));
1814        if (branch->lnum == 0) {
1815                /*
1816                 * This nnode was not written which just means that the LEB
1817                 * properties in the subtree below it describe empty LEBs. We
1818                 * make the nnode as though we had read it, which in fact means
1819                 * doing almost nothing.
1820                 */
1821                if (c->big_lpt)
1822                        nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1823        } else {
1824                err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1825                                     c->nnode_sz, 1);
1826                if (err)
1827                        return ERR_PTR(err);
1828                err = ubifs_unpack_nnode(c, buf, nnode);
1829                if (err)
1830                        return ERR_PTR(err);
1831        }
1832        err = validate_nnode(c, nnode, parent, iip);
1833        if (err)
1834                return ERR_PTR(err);
1835        if (!c->big_lpt)
1836                nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1837        nnode->level = parent->level - 1;
1838        nnode->parent = parent;
1839        nnode->iip = iip;
1840        return nnode;
1841}
1842
1843/**
1844 * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
1845 * @c: the UBIFS file-system description object
1846 * @path: where to put the pnode
1847 * @parent: parent of the pnode
1848 * @iip: index in parent of the pnode
1849 *
1850 * This function returns a pointer to the pnode on success or a negative error
1851 * code on failure.
1852 */
1853static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
1854                                          struct lpt_scan_node *path,
1855                                          struct ubifs_nnode *parent, int iip)
1856{
1857        struct ubifs_nbranch *branch;
1858        struct ubifs_pnode *pnode;
1859        void *buf = c->lpt_nod_buf;
1860        int err;
1861
1862        branch = &parent->nbranch[iip];
1863        pnode = branch->pnode;
1864        if (pnode) {
1865                path->in_tree = 1;
1866                path->ptr.pnode = pnode;
1867                return pnode;
1868        }
1869        pnode = &path->pnode;
1870        path->in_tree = 0;
1871        path->ptr.pnode = pnode;
1872        memset(pnode, 0, sizeof(struct ubifs_pnode));
1873        if (branch->lnum == 0) {
1874                /*
1875                 * This pnode was not written which just means that the LEB
1876                 * properties in it describe empty LEBs. We make the pnode as
1877                 * though we had read it.
1878                 */
1879                int i;
1880
1881                if (c->big_lpt)
1882                        pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1883                for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1884                        struct ubifs_lprops * const lprops = &pnode->lprops[i];
1885
1886                        lprops->free = c->leb_size;
1887                        lprops->flags = ubifs_categorize_lprops(c, lprops);
1888                }
1889        } else {
1890                ubifs_assert(branch->lnum >= c->lpt_first &&
1891                             branch->lnum <= c->lpt_last);
1892                ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
1893                err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1894                                     c->pnode_sz, 1);
1895                if (err)
1896                        return ERR_PTR(err);
1897                err = unpack_pnode(c, buf, pnode);
1898                if (err)
1899                        return ERR_PTR(err);
1900        }
1901        err = validate_pnode(c, pnode, parent, iip);
1902        if (err)
1903                return ERR_PTR(err);
1904        if (!c->big_lpt)
1905                pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1906        pnode->parent = parent;
1907        pnode->iip = iip;
1908        set_pnode_lnum(c, pnode);
1909        return pnode;
1910}
1911
1912/**
1913 * ubifs_lpt_scan_nolock - scan the LPT.
1914 * @c: the UBIFS file-system description object
1915 * @start_lnum: LEB number from which to start scanning
1916 * @end_lnum: LEB number at which to stop scanning
1917 * @scan_cb: callback function called for each lprops
1918 * @data: data to be passed to the callback function
1919 *
1920 * This function returns %0 on success and a negative error code on failure.
1921 */
1922int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
1923                          ubifs_lpt_scan_callback scan_cb, void *data)
1924{
1925        int err = 0, i, h, iip, shft;
1926        struct ubifs_nnode *nnode;
1927        struct ubifs_pnode *pnode;
1928        struct lpt_scan_node *path;
1929
1930        if (start_lnum == -1) {
1931                start_lnum = end_lnum + 1;
1932                if (start_lnum >= c->leb_cnt)
1933                        start_lnum = c->main_first;
1934        }
1935
1936        ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
1937        ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
1938
1939        if (!c->nroot) {
1940                err = ubifs_read_nnode(c, NULL, 0);
1941                if (err)
1942                        return err;
1943        }
1944
1945        path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
1946                       GFP_NOFS);
1947        if (!path)
1948                return -ENOMEM;
1949
1950        path[0].ptr.nnode = c->nroot;
1951        path[0].in_tree = 1;
1952again:
1953        /* Descend to the pnode containing start_lnum */
1954        nnode = c->nroot;
1955        i = start_lnum - c->main_first;
1956        shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1957        for (h = 1; h < c->lpt_hght; h++) {
1958                iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1959                shft -= UBIFS_LPT_FANOUT_SHIFT;
1960                nnode = scan_get_nnode(c, path + h, nnode, iip);
1961                if (IS_ERR(nnode)) {
1962                        err = PTR_ERR(nnode);
1963                        goto out;
1964                }
1965        }
1966        iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1967        shft -= UBIFS_LPT_FANOUT_SHIFT;
1968        pnode = scan_get_pnode(c, path + h, nnode, iip);
1969        if (IS_ERR(pnode)) {
1970                err = PTR_ERR(pnode);
1971                goto out;
1972        }
1973        iip = (i & (UBIFS_LPT_FANOUT - 1));
1974
1975        /* Loop for each lprops */
1976        while (1) {
1977                struct ubifs_lprops *lprops = &pnode->lprops[iip];
1978                int ret, lnum = lprops->lnum;
1979
1980                ret = scan_cb(c, lprops, path[h].in_tree, data);
1981                if (ret < 0) {
1982                        err = ret;
1983                        goto out;
1984                }
1985                if (ret & LPT_SCAN_ADD) {
1986                        /* Add all the nodes in path to the tree in memory */
1987                        for (h = 1; h < c->lpt_hght; h++) {
1988                                const size_t sz = sizeof(struct ubifs_nnode);
1989                                struct ubifs_nnode *parent;
1990
1991                                if (path[h].in_tree)
1992                                        continue;
1993                                nnode = kmemdup(&path[h].nnode, sz, GFP_NOFS);
1994                                if (!nnode) {
1995                                        err = -ENOMEM;
1996                                        goto out;
1997                                }
1998                                parent = nnode->parent;
1999                                parent->nbranch[nnode->iip].nnode = nnode;
2000                                path[h].ptr.nnode = nnode;
2001                                path[h].in_tree = 1;
2002                                path[h + 1].cnode.parent = nnode;
2003                        }
2004                        if (path[h].in_tree)
2005                                ubifs_ensure_cat(c, lprops);
2006                        else {
2007                                const size_t sz = sizeof(struct ubifs_pnode);
2008                                struct ubifs_nnode *parent;
2009
2010                                pnode = kmemdup(&path[h].pnode, sz, GFP_NOFS);
2011                                if (!pnode) {
2012                                        err = -ENOMEM;
2013                                        goto out;
2014                                }
2015                                parent = pnode->parent;
2016                                parent->nbranch[pnode->iip].pnode = pnode;
2017                                path[h].ptr.pnode = pnode;
2018                                path[h].in_tree = 1;
2019                                update_cats(c, pnode);
2020                                c->pnodes_have += 1;
2021                        }
2022                        err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)
2023                                                  c->nroot, 0, 0);
2024                        if (err)
2025                                goto out;
2026                        err = dbg_check_cats(c);
2027                        if (err)
2028                                goto out;
2029                }
2030                if (ret & LPT_SCAN_STOP) {
2031                        err = 0;
2032                        break;
2033                }
2034                /* Get the next lprops */
2035                if (lnum == end_lnum) {
2036                        /*
2037                         * We got to the end without finding what we were
2038                         * looking for
2039                         */
2040                        err = -ENOSPC;
2041                        goto out;
2042                }
2043                if (lnum + 1 >= c->leb_cnt) {
2044                        /* Wrap-around to the beginning */
2045                        start_lnum = c->main_first;
2046                        goto again;
2047                }
2048                if (iip + 1 < UBIFS_LPT_FANOUT) {
2049                        /* Next lprops is in the same pnode */
2050                        iip += 1;
2051                        continue;
2052                }
2053                /* We need to get the next pnode. Go up until we can go right */
2054                iip = pnode->iip;
2055                while (1) {
2056                        h -= 1;
2057                        ubifs_assert(h >= 0);
2058                        nnode = path[h].ptr.nnode;
2059                        if (iip + 1 < UBIFS_LPT_FANOUT)
2060                                break;
2061                        iip = nnode->iip;
2062                }
2063                /* Go right */
2064                iip += 1;
2065                /* Descend to the pnode */
2066                h += 1;
2067                for (; h < c->lpt_hght; h++) {
2068                        nnode = scan_get_nnode(c, path + h, nnode, iip);
2069                        if (IS_ERR(nnode)) {
2070                                err = PTR_ERR(nnode);
2071                                goto out;
2072                        }
2073                        iip = 0;
2074                }
2075                pnode = scan_get_pnode(c, path + h, nnode, iip);
2076                if (IS_ERR(pnode)) {
2077                        err = PTR_ERR(pnode);
2078                        goto out;
2079                }
2080                iip = 0;
2081        }
2082out:
2083        kfree(path);
2084        return err;
2085}
2086
2087/**
2088 * dbg_chk_pnode - check a pnode.
2089 * @c: the UBIFS file-system description object
2090 * @pnode: pnode to check
2091 * @col: pnode column
2092 *
2093 * This function returns %0 on success and a negative error code on failure.
2094 */
2095static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
2096                         int col)
2097{
2098        int i;
2099
2100        if (pnode->num != col) {
2101                ubifs_err("pnode num %d expected %d parent num %d iip %d",
2102                          pnode->num, col, pnode->parent->num, pnode->iip);
2103                return -EINVAL;
2104        }
2105        for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2106                struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
2107                int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
2108                           c->main_first;
2109                int found, cat = lprops->flags & LPROPS_CAT_MASK;
2110                struct ubifs_lpt_heap *heap;
2111                struct list_head *list = NULL;
2112
2113                if (lnum >= c->leb_cnt)
2114                        continue;
2115                if (lprops->lnum != lnum) {
2116                        ubifs_err("bad LEB number %d expected %d",
2117                                  lprops->lnum, lnum);
2118                        return -EINVAL;
2119                }
2120                if (lprops->flags & LPROPS_TAKEN) {
2121                        if (cat != LPROPS_UNCAT) {
2122                                ubifs_err("LEB %d taken but not uncat %d",
2123                                          lprops->lnum, cat);
2124                                return -EINVAL;
2125                        }
2126                        continue;
2127                }
2128                if (lprops->flags & LPROPS_INDEX) {
2129                        switch (cat) {
2130                        case LPROPS_UNCAT:
2131                        case LPROPS_DIRTY_IDX:
2132                        case LPROPS_FRDI_IDX:
2133                                break;
2134                        default:
2135                                ubifs_err("LEB %d index but cat %d",
2136                                          lprops->lnum, cat);
2137                                return -EINVAL;
2138                        }
2139                } else {
2140                        switch (cat) {
2141                        case LPROPS_UNCAT:
2142                        case LPROPS_DIRTY:
2143                        case LPROPS_FREE:
2144                        case LPROPS_EMPTY:
2145                        case LPROPS_FREEABLE:
2146                                break;
2147                        default:
2148                                ubifs_err("LEB %d not index but cat %d",
2149                                          lprops->lnum, cat);
2150                                return -EINVAL;
2151                        }
2152                }
2153                switch (cat) {
2154                case LPROPS_UNCAT:
2155                        list = &c->uncat_list;
2156                        break;
2157                case LPROPS_EMPTY:
2158                        list = &c->empty_list;
2159                        break;
2160                case LPROPS_FREEABLE:
2161                        list = &c->freeable_list;
2162                        break;
2163                case LPROPS_FRDI_IDX:
2164                        list = &c->frdi_idx_list;
2165                        break;
2166                }
2167                found = 0;
2168                switch (cat) {
2169                case LPROPS_DIRTY:
2170                case LPROPS_DIRTY_IDX:
2171                case LPROPS_FREE:
2172                        heap = &c->lpt_heap[cat - 1];
2173                        if (lprops->hpos < heap->cnt &&
2174                            heap->arr[lprops->hpos] == lprops)
2175                                found = 1;
2176                        break;
2177                case LPROPS_UNCAT:
2178                case LPROPS_EMPTY:
2179                case LPROPS_FREEABLE:
2180                case LPROPS_FRDI_IDX:
2181                        list_for_each_entry(lp, list, list)
2182                                if (lprops == lp) {
2183                                        found = 1;
2184                                        break;
2185                                }
2186                        break;
2187                }
2188                if (!found) {
2189                        ubifs_err("LEB %d cat %d not found in cat heap/list",
2190                                  lprops->lnum, cat);
2191                        return -EINVAL;
2192                }
2193                switch (cat) {
2194                case LPROPS_EMPTY:
2195                        if (lprops->free != c->leb_size) {
2196                                ubifs_err("LEB %d cat %d free %d dirty %d",
2197                                          lprops->lnum, cat, lprops->free,
2198                                          lprops->dirty);
2199                                return -EINVAL;
2200                        }
2201                case LPROPS_FREEABLE:
2202                case LPROPS_FRDI_IDX:
2203                        if (lprops->free + lprops->dirty != c->leb_size) {
2204                                ubifs_err("LEB %d cat %d free %d dirty %d",
2205                                          lprops->lnum, cat, lprops->free,
2206                                          lprops->dirty);
2207                                return -EINVAL;
2208                        }
2209                }
2210        }
2211        return 0;
2212}
2213
2214/**
2215 * dbg_check_lpt_nodes - check nnodes and pnodes.
2216 * @c: the UBIFS file-system description object
2217 * @cnode: next cnode (nnode or pnode) to check
2218 * @row: row of cnode (root is zero)
2219 * @col: column of cnode (leftmost is zero)
2220 *
2221 * This function returns %0 on success and a negative error code on failure.
2222 */
2223int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
2224                        int row, int col)
2225{
2226        struct ubifs_nnode *nnode, *nn;
2227        struct ubifs_cnode *cn;
2228        int num, iip = 0, err;
2229
2230        if (!dbg_is_chk_lprops(c))
2231                return 0;
2232
2233        while (cnode) {
2234                ubifs_assert(row >= 0);
2235                nnode = cnode->parent;
2236                if (cnode->level) {
2237                        /* cnode is a nnode */
2238                        num = calc_nnode_num(row, col);
2239                        if (cnode->num != num) {
2240                                ubifs_err("nnode num %d expected %d parent num %d iip %d",
2241                                          cnode->num, num,
2242                                          (nnode ? nnode->num : 0), cnode->iip);
2243                                return -EINVAL;
2244                        }
2245                        nn = (struct ubifs_nnode *)cnode;
2246                        while (iip < UBIFS_LPT_FANOUT) {
2247                                cn = nn->nbranch[iip].cnode;
2248                                if (cn) {
2249                                        /* Go down */
2250                                        row += 1;
2251                                        col <<= UBIFS_LPT_FANOUT_SHIFT;
2252                                        col += iip;
2253                                        iip = 0;
2254                                        cnode = cn;
2255                                        break;
2256                                }
2257                                /* Go right */
2258                                iip += 1;
2259                        }
2260                        if (iip < UBIFS_LPT_FANOUT)
2261                                continue;
2262                } else {
2263                        struct ubifs_pnode *pnode;
2264
2265                        /* cnode is a pnode */
2266                        pnode = (struct ubifs_pnode *)cnode;
2267                        err = dbg_chk_pnode(c, pnode, col);
2268                        if (err)
2269                                return err;
2270                }
2271                /* Go up and to the right */
2272                row -= 1;
2273                col >>= UBIFS_LPT_FANOUT_SHIFT;
2274                iip = cnode->iip + 1;
2275                cnode = (struct ubifs_cnode *)nnode;
2276        }
2277        return 0;
2278}
2279
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