fs/ubifs/lpt_commit.c

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  *
  19  * Authors: Adrian Hunter
  20  *          Artem Bityutskiy (Битюцкий Артём)
  21  */
  22
  23 /*
  24  * This file implements commit-related functionality of the LEB properties
  25  * subsystem.
  26  */
  27
  28 #include <linux/crc16.h>
  29 #include <linux/slab.h>
  30 #include "ubifs.h"
  31
  32 /**
  33  * first_dirty_cnode - find first dirty cnode.
  34  * @c: UBIFS file-system description object
  35  * @nnode: nnode at which to start
  36  *
  37  * This function returns the first dirty cnode or %NULL if there is not one.
  38  */
  39 static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
  40 {
  41         ubifs_assert(nnode);
  42         while (1) {
  43                 int i, cont = 0;
  44
  45                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
  46                         struct ubifs_cnode *cnode;
  47
  48                         cnode = nnode->nbranch[i].cnode;
  49                         if (cnode &&
  50                             test_bit(DIRTY_CNODE, &cnode->flags)) {
  51                                 if (cnode->level == 0)
  52                                         return cnode;
  53                                 nnode = (struct ubifs_nnode *)cnode;
  54                                 cont = 1;
  55                                 break;
  56                         }
  57                 }
  58                 if (!cont)
  59                         return (struct ubifs_cnode *)nnode;
  60         }
  61 }
  62
  63 /**
  64  * next_dirty_cnode - find next dirty cnode.
  65  * @cnode: cnode from which to begin searching
  66  *
  67  * This function returns the next dirty cnode or %NULL if there is not one.
  68  */
  69 static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
  70 {
  71         struct ubifs_nnode *nnode;
  72         int i;
  73
  74         ubifs_assert(cnode);
  75         nnode = cnode->parent;
  76         if (!nnode)
  77                 return NULL;
  78         for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
  79                 cnode = nnode->nbranch[i].cnode;
  80                 if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
  81                         if (cnode->level == 0)
  82                                 return cnode; /* cnode is a pnode */
  83                         /* cnode is a nnode */
  84                         return first_dirty_cnode((struct ubifs_nnode *)cnode);
  85                 }
  86         }
  87         return (struct ubifs_cnode *)nnode;
  88 }
  89
  90 /**
  91  * get_cnodes_to_commit - create list of dirty cnodes to commit.
  92  * @c: UBIFS file-system description object
  93  *
  94  * This function returns the number of cnodes to commit.
  95  */
  96 static int get_cnodes_to_commit(struct ubifs_info *c)
  97 {
  98         struct ubifs_cnode *cnode, *cnext;
  99         int cnt = 0;
 100
 101         if (!c->nroot)
 102                 return 0;
 103
 104         if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
 105                 return 0;
 106
 107         c->lpt_cnext = first_dirty_cnode(c->nroot);
 108         cnode = c->lpt_cnext;
 109         if (!cnode)
 110                 return 0;
 111         cnt += 1;
 112         while (1) {
 113                 ubifs_assert(!test_bit(COW_ZNODE, &cnode->flags));
 114                 __set_bit(COW_ZNODE, &cnode->flags);
 115                 cnext = next_dirty_cnode(cnode);
 116                 if (!cnext) {
 117                         cnode->cnext = c->lpt_cnext;
 118                         break;
 119                 }
 120                 cnode->cnext = cnext;
 121                 cnode = cnext;
 122                 cnt += 1;
 123         }
 124         dbg_cmt("committing %d cnodes", cnt);
 125         dbg_lp("committing %d cnodes", cnt);
 126         ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
 127         return cnt;
 128 }
 129
 130 /**
 131  * upd_ltab - update LPT LEB properties.
 132  * @c: UBIFS file-system description object
 133  * @lnum: LEB number
 134  * @free: amount of free space
 135  * @dirty: amount of dirty space to add
 136  */
 137 static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
 138 {
 139         dbg_lp("LEB %d free %d dirty %d to %d +%d",
 140                lnum, c->ltab[lnum - c->lpt_first].free,
 141                c->ltab[lnum - c->lpt_first].dirty, free, dirty);
 142         ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
 143         c->ltab[lnum - c->lpt_first].free = free;
 144         c->ltab[lnum - c->lpt_first].dirty += dirty;
 145 }
 146
 147 /**
 148  * alloc_lpt_leb - allocate an LPT LEB that is empty.
 149  * @c: UBIFS file-system description object
 150  * @lnum: LEB number is passed and returned here
 151  *
 152  * This function finds the next empty LEB in the ltab starting from @lnum. If a
 153  * an empty LEB is found it is returned in @lnum and the function returns %0.
 154  * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
 155  * never to run out of space.
 156  */
 157 static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
 158 {
 159         int i, n;
 160
 161         n = *lnum - c->lpt_first + 1;
 162         for (i = n; i < c->lpt_lebs; i++) {
 163                 if (c->ltab[i].tgc || c->ltab[i].cmt)
 164                         continue;
 165                 if (c->ltab[i].free == c->leb_size) {
 166                         c->ltab[i].cmt = 1;
 167                         *lnum = i + c->lpt_first;
 168                         return 0;
 169                 }
 170         }
 171
 172         for (i = 0; i < n; i++) {
 173                 if (c->ltab[i].tgc || c->ltab[i].cmt)
 174                         continue;
 175                 if (c->ltab[i].free == c->leb_size) {
 176                         c->ltab[i].cmt = 1;
 177                         *lnum = i + c->lpt_first;
 178                         return 0;
 179                 }
 180         }
 181         return -ENOSPC;
 182 }
 183
 184 /**
 185  * layout_cnodes - layout cnodes for commit.
 186  * @c: UBIFS file-system description object
 187  *
 188  * This function returns %0 on success and a negative error code on failure.
 189  */
 190 static int layout_cnodes(struct ubifs_info *c)
 191 {
 192         int lnum, offs, len, alen, done_lsave, done_ltab, err;
 193         struct ubifs_cnode *cnode;
 194
 195         err = dbg_chk_lpt_sz(c, 0, 0);
 196         if (err)
 197                 return err;
 198         cnode = c->lpt_cnext;
 199         if (!cnode)
 200                 return 0;
 201         lnum = c->nhead_lnum;
 202         offs = c->nhead_offs;
 203         /* Try to place lsave and ltab nicely */
 204         done_lsave = !c->big_lpt;
 205         done_ltab = 0;
 206         if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
 207                 done_lsave = 1;
 208                 c->lsave_lnum = lnum;
 209                 c->lsave_offs = offs;
 210                 offs += c->lsave_sz;
 211                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 212         }
 213
 214         if (offs + c->ltab_sz <= c->leb_size) {
 215                 done_ltab = 1;
 216                 c->ltab_lnum = lnum;
 217                 c->ltab_offs = offs;
 218                 offs += c->ltab_sz;
 219                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 220         }
 221
 222         do {
 223                 if (cnode->level) {
 224                         len = c->nnode_sz;
 225                         c->dirty_nn_cnt -= 1;
 226                 } else {
 227                         len = c->pnode_sz;
 228                         c->dirty_pn_cnt -= 1;
 229                 }
 230                 while (offs + len > c->leb_size) {
 231                         alen = ALIGN(offs, c->min_io_size);
 232                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 233                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 234                         err = alloc_lpt_leb(c, &lnum);
 235                         if (err)
 236                                 goto no_space;
 237                         offs = 0;
 238                         ubifs_assert(lnum >= c->lpt_first &&
 239                                      lnum <= c->lpt_last);
 240                         /* Try to place lsave and ltab nicely */
 241                         if (!done_lsave) {
 242                                 done_lsave = 1;
 243                                 c->lsave_lnum = lnum;
 244                                 c->lsave_offs = offs;
 245                                 offs += c->lsave_sz;
 246                                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 247                                 continue;
 248                         }
 249                         if (!done_ltab) {
 250                                 done_ltab = 1;
 251                                 c->ltab_lnum = lnum;
 252                                 c->ltab_offs = offs;
 253                                 offs += c->ltab_sz;
 254                                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 255                                 continue;
 256                         }
 257                         break;
 258                 }
 259                 if (cnode->parent) {
 260                         cnode->parent->nbranch[cnode->iip].lnum = lnum;
 261                         cnode->parent->nbranch[cnode->iip].offs = offs;
 262                 } else {
 263                         c->lpt_lnum = lnum;
 264                         c->lpt_offs = offs;
 265                 }
 266                 offs += len;
 267                 dbg_chk_lpt_sz(c, 1, len);
 268                 cnode = cnode->cnext;
 269         } while (cnode && cnode != c->lpt_cnext);
 270
 271         /* Make sure to place LPT's save table */
 272         if (!done_lsave) {
 273                 if (offs + c->lsave_sz > c->leb_size) {
 274                         alen = ALIGN(offs, c->min_io_size);
 275                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 276                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 277                         err = alloc_lpt_leb(c, &lnum);
 278                         if (err)
 279                                 goto no_space;
 280                         offs = 0;
 281                         ubifs_assert(lnum >= c->lpt_first &&
 282                                      lnum <= c->lpt_last);
 283                 }
 284                 done_lsave = 1;
 285                 c->lsave_lnum = lnum;
 286                 c->lsave_offs = offs;
 287                 offs += c->lsave_sz;
 288                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 289         }
 290
 291         /* Make sure to place LPT's own lprops table */
 292         if (!done_ltab) {
 293                 if (offs + c->ltab_sz > c->leb_size) {
 294                         alen = ALIGN(offs, c->min_io_size);
 295                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 296                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 297                         err = alloc_lpt_leb(c, &lnum);
 298                         if (err)
 299                                 goto no_space;
 300                         offs = 0;
 301                         ubifs_assert(lnum >= c->lpt_first &&
 302                                      lnum <= c->lpt_last);
 303                 }
 304                 done_ltab = 1;
 305                 c->ltab_lnum = lnum;
 306                 c->ltab_offs = offs;
 307                 offs += c->ltab_sz;
 308                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 309         }
 310
 311         alen = ALIGN(offs, c->min_io_size);
 312         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
 313         dbg_chk_lpt_sz(c, 4, alen - offs);
 314         err = dbg_chk_lpt_sz(c, 3, alen);
 315         if (err)
 316                 return err;
 317         return 0;
 318
 319 no_space:
 320         ubifs_err("LPT out of space");
 321         dbg_err("LPT out of space at LEB %d:%d needing %d, done_ltab %d, "
 322                 "done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
 323         dbg_dump_lpt_info(c);
 324         dbg_dump_lpt_lebs(c);
 325         dump_stack();
 326         return err;
 327 }
 328
 329 /**
 330  * realloc_lpt_leb - allocate an LPT LEB that is empty.
 331  * @c: UBIFS file-system description object
 332  * @lnum: LEB number is passed and returned here
 333  *
 334  * This function duplicates exactly the results of the function alloc_lpt_leb.
 335  * It is used during end commit to reallocate the same LEB numbers that were
 336  * allocated by alloc_lpt_leb during start commit.
 337  *
 338  * This function finds the next LEB that was allocated by the alloc_lpt_leb
 339  * function starting from @lnum. If a LEB is found it is returned in @lnum and
 340  * the function returns %0. Otherwise the function returns -ENOSPC.
 341  * Note however, that LPT is designed never to run out of space.
 342  */
 343 static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
 344 {
 345         int i, n;
 346
 347         n = *lnum - c->lpt_first + 1;
 348         for (i = n; i < c->lpt_lebs; i++)
 349                 if (c->ltab[i].cmt) {
 350                         c->ltab[i].cmt = 0;
 351                         *lnum = i + c->lpt_first;
 352                         return 0;
 353                 }
 354
 355         for (i = 0; i < n; i++)
 356                 if (c->ltab[i].cmt) {
 357                         c->ltab[i].cmt = 0;
 358                         *lnum = i + c->lpt_first;
 359                         return 0;
 360                 }
 361         return -ENOSPC;
 362 }
 363
 364 /**
 365  * write_cnodes - write cnodes for commit.
 366  * @c: UBIFS file-system description object
 367  *
 368  * This function returns %0 on success and a negative error code on failure.
 369  */
 370 static int write_cnodes(struct ubifs_info *c)
 371 {
 372         int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
 373         struct ubifs_cnode *cnode;
 374         void *buf = c->lpt_buf;
 375
 376         cnode = c->lpt_cnext;
 377         if (!cnode)
 378                 return 0;
 379         lnum = c->nhead_lnum;
 380         offs = c->nhead_offs;
 381         from = offs;
 382         /* Ensure empty LEB is unmapped */
 383         if (offs == 0) {
 384                 err = ubifs_leb_unmap(c, lnum);
 385                 if (err)
 386                         return err;
 387         }
 388         /* Try to place lsave and ltab nicely */
 389         done_lsave = !c->big_lpt;
 390         done_ltab = 0;
 391         if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
 392                 done_lsave = 1;
 393                 ubifs_pack_lsave(c, buf + offs, c->lsave);
 394                 offs += c->lsave_sz;
 395                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 396         }
 397
 398         if (offs + c->ltab_sz <= c->leb_size) {
 399                 done_ltab = 1;
 400                 ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
 401                 offs += c->ltab_sz;
 402                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 403         }
 404
 405         /* Loop for each cnode */
 406         do {
 407                 if (cnode->level)
 408                         len = c->nnode_sz;
 409                 else
 410                         len = c->pnode_sz;
 411                 while (offs + len > c->leb_size) {
 412                         wlen = offs - from;
 413                         if (wlen) {
 414                                 alen = ALIGN(wlen, c->min_io_size);
 415                                 memset(buf + offs, 0xff, alen - wlen);
 416                                 err = ubifs_leb_write(c, lnum, buf + from, from,
 417                                                        alen, UBI_SHORTTERM);
 418                                 if (err)
 419                                         return err;
 420                         }
 421                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 422                         err = realloc_lpt_leb(c, &lnum);
 423                         if (err)
 424                                 goto no_space;
 425                         offs = from = 0;
 426                         ubifs_assert(lnum >= c->lpt_first &&
 427                                      lnum <= c->lpt_last);
 428                         err = ubifs_leb_unmap(c, lnum);
 429                         if (err)
 430                                 return err;
 431                         /* Try to place lsave and ltab nicely */
 432                         if (!done_lsave) {
 433                                 done_lsave = 1;
 434                                 ubifs_pack_lsave(c, buf + offs, c->lsave);
 435                                 offs += c->lsave_sz;
 436                                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 437                                 continue;
 438                         }
 439                         if (!done_ltab) {
 440                                 done_ltab = 1;
 441                                 ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
 442                                 offs += c->ltab_sz;
 443                                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
 444                                 continue;
 445                         }
 446                         break;
 447                 }
 448                 if (cnode->level)
 449                         ubifs_pack_nnode(c, buf + offs,
 450                                          (struct ubifs_nnode *)cnode);
 451                 else
 452                         ubifs_pack_pnode(c, buf + offs,
 453                                          (struct ubifs_pnode *)cnode);
 454                 /*
 455                  * The reason for the barriers is the same as in case of TNC.
 456                  * See comment in 'write_index()'. 'dirty_cow_nnode()' and
 457                  * 'dirty_cow_pnode()' are the functions for which this is
 458                  * important.
 459                  */
 460                 clear_bit(DIRTY_CNODE, &cnode->flags);
 461                 smp_mb__before_clear_bit();
 462                 clear_bit(COW_ZNODE, &cnode->flags);
 463                 smp_mb__after_clear_bit();
 464                 offs += len;
 465                 dbg_chk_lpt_sz(c, 1, len);
 466                 cnode = cnode->cnext;
 467         } while (cnode && cnode != c->lpt_cnext);
 468
 469         /* Make sure to place LPT's save table */
 470         if (!done_lsave) {
 471                 if (offs + c->lsave_sz > c->leb_size) {
 472                         wlen = offs - from;
 473                         alen = ALIGN(wlen, c->min_io_size);
 474                         memset(buf + offs, 0xff, alen - wlen);
 475                         err = ubifs_leb_write(c, lnum, buf + from, from, alen,
 476                                               UBI_SHORTTERM);
 477                         if (err)
 478                                 return err;
 479                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
 480                         err = realloc_lpt_leb(c, &lnum);
 481                         if (err)
 482                                 goto no_space;
 483                         offs = from = 0;
 484                         ubifs_assert(lnum >= c->lpt_first &&
 485                                      lnum <= c->lpt_last);
 486                         err = ubifs_leb_unmap(c, lnum);
 487                         if (err)
 488                                 return err;
 489                 }
 490                 done_lsave = 1;
 491                 ubifs_pack_lsave(c, buf + offs, c->lsave);
 492                 offs += c->lsave_sz;
 493                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
 494         }
 495
 496         /* Make sure to place LPT's own lprops table */
 497         if (!done_ltab) {
 498                 if (offs + c->ltab_sz > c->leb_size) {
 499                         wlen = offs - from;
 500                         alen = ALIGN(wlen, c->min_io_size);
 501                         memset(buf + offs, 0xff, alen - wlen);
 502                         err = ubifs_leb_write(c, lnum, buf + from, from, alen,
 503                                               UBI_SHORTTERM);
 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, UBI_SHORTTERM);
 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
 547 no_space:
 548         ubifs_err("LPT out of space mismatch");
 549         dbg_err("LPT out of space mismatch at LEB %d:%d needing %d, done_ltab "
 550                 "%d, done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
 551         dbg_dump_lpt_info(c);
 552         dbg_dump_lpt_lebs(c);
 553         dump_stack();
 554         return err;
 555 }
 556
 557 /**
 558  * next_pnode_to_dirty - find next pnode to dirty.
 559  * @c: UBIFS file-system description object
 560  * @pnode: pnode
 561  *
 562  * This function returns the next pnode to dirty or %NULL if there are no more
 563  * pnodes.  Note that pnodes that have never been written (lnum == 0) are
 564  * skipped.
 565  */
 566 static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
 567                                                struct ubifs_pnode *pnode)
 568 {
 569         struct ubifs_nnode *nnode;
 570         int iip;
 571
 572         /* Try to go right */
 573         nnode = pnode->parent;
 574         for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
 575                 if (nnode->nbranch[iip].lnum)
 576                         return ubifs_get_pnode(c, nnode, iip);
 577         }
 578
 579         /* Go up while can't go right */
 580         do {
 581                 iip = nnode->iip + 1;
 582                 nnode = nnode->parent;
 583                 if (!nnode)
 584                         return NULL;
 585                 for (; iip < UBIFS_LPT_FANOUT; iip++) {
 586                         if (nnode->nbranch[iip].lnum)
 587                                 break;
 588                 }
 589        } while (iip >= UBIFS_LPT_FANOUT);
 590
 591         /* Go right */
 592         nnode = ubifs_get_nnode(c, nnode, iip);
 593         if (IS_ERR(nnode))
 594                 return (void *)nnode;
 595
 596         /* Go down to level 1 */
 597         while (nnode->level > 1) {
 598                 for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
 599                         if (nnode->nbranch[iip].lnum)
 600                                 break;
 601                 }
 602                 if (iip >= UBIFS_LPT_FANOUT) {
 603                         /*
 604                          * Should not happen, but we need to keep going
 605                          * if it does.
 606                          */
 607                         iip = 0;
 608                 }
 609                 nnode = ubifs_get_nnode(c, nnode, iip);
 610                 if (IS_ERR(nnode))
 611                         return (void *)nnode;
 612         }
 613
 614         for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
 615                 if (nnode->nbranch[iip].lnum)
 616                         break;
 617         if (iip >= UBIFS_LPT_FANOUT)
 618                 /* Should not happen, but we need to keep going if it does */
 619                 iip = 0;
 620         return ubifs_get_pnode(c, nnode, iip);
 621 }
 622
 623 /**
 624  * pnode_lookup - lookup a pnode in the LPT.
 625  * @c: UBIFS file-system description object
 626  * @i: pnode number (0 to main_lebs - 1)
 627  *
 628  * This function returns a pointer to the pnode on success or a negative
 629  * error code on failure.
 630  */
 631 static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
 632 {
 633         int err, h, iip, shft;
 634         struct ubifs_nnode *nnode;
 635
 636         if (!c->nroot) {
 637                 err = ubifs_read_nnode(c, NULL, 0);
 638                 if (err)
 639                         return ERR_PTR(err);
 640         }
 641         i <<= UBIFS_LPT_FANOUT_SHIFT;
 642         nnode = c->nroot;
 643         shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
 644         for (h = 1; h < c->lpt_hght; h++) {
 645                 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
 646                 shft -= UBIFS_LPT_FANOUT_SHIFT;
 647                 nnode = ubifs_get_nnode(c, nnode, iip);
 648                 if (IS_ERR(nnode))
 649                         return ERR_CAST(nnode);
 650         }
 651         iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
 652         return ubifs_get_pnode(c, nnode, iip);
 653 }
 654
 655 /**
 656  * add_pnode_dirt - add dirty space to LPT LEB properties.
 657  * @c: UBIFS file-system description object
 658  * @pnode: pnode for which to add dirt
 659  */
 660 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
 661 {
 662         ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
 663                            c->pnode_sz);
 664 }
 665
 666 /**
 667  * do_make_pnode_dirty - mark a pnode dirty.
 668  * @c: UBIFS file-system description object
 669  * @pnode: pnode to mark dirty
 670  */
 671 static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
 672 {
 673         /* Assumes cnext list is empty i.e. not called during commit */
 674         if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
 675                 struct ubifs_nnode *nnode;
 676
 677                 c->dirty_pn_cnt += 1;
 678                 add_pnode_dirt(c, pnode);
 679                 /* Mark parent and ancestors dirty too */
 680                 nnode = pnode->parent;
 681                 while (nnode) {
 682                         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 683                                 c->dirty_nn_cnt += 1;
 684                                 ubifs_add_nnode_dirt(c, nnode);
 685                                 nnode = nnode->parent;
 686                         } else
 687                                 break;
 688                 }
 689         }
 690 }
 691
 692 /**
 693  * make_tree_dirty - mark the entire LEB properties tree dirty.
 694  * @c: UBIFS file-system description object
 695  *
 696  * This function is used by the "small" LPT model to cause the entire LEB
 697  * properties tree to be written.  The "small" LPT model does not use LPT
 698  * garbage collection because it is more efficient to write the entire tree
 699  * (because it is small).
 700  *
 701  * This function returns %0 on success and a negative error code on failure.
 702  */
 703 static int make_tree_dirty(struct ubifs_info *c)
 704 {
 705         struct ubifs_pnode *pnode;
 706
 707         pnode = pnode_lookup(c, 0);
 708         if (IS_ERR(pnode))
 709                 return PTR_ERR(pnode);
 710
 711         while (pnode) {
 712                 do_make_pnode_dirty(c, pnode);
 713                 pnode = next_pnode_to_dirty(c, pnode);
 714                 if (IS_ERR(pnode))
 715                         return PTR_ERR(pnode);
 716         }
 717         return 0;
 718 }
 719
 720 /**
 721  * need_write_all - determine if the LPT area is running out of free space.
 722  * @c: UBIFS file-system description object
 723  *
 724  * This function returns %1 if the LPT area is running out of free space and %0
 725  * if it is not.
 726  */
 727 static int need_write_all(struct ubifs_info *c)
 728 {
 729         long long free = 0;
 730         int i;
 731
 732         for (i = 0; i < c->lpt_lebs; i++) {
 733                 if (i + c->lpt_first == c->nhead_lnum)
 734                         free += c->leb_size - c->nhead_offs;
 735                 else if (c->ltab[i].free == c->leb_size)
 736                         free += c->leb_size;
 737                 else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
 738                         free += c->leb_size;
 739         }
 740         /* Less than twice the size left */
 741         if (free <= c->lpt_sz * 2)
 742                 return 1;
 743         return 0;
 744 }
 745
 746 /**
 747  * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
 748  * @c: UBIFS file-system description object
 749  *
 750  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
 751  * free space and so may be reused as soon as the next commit is completed.
 752  * This function is called during start commit to mark LPT LEBs for trivial GC.
 753  */
 754 static void lpt_tgc_start(struct ubifs_info *c)
 755 {
 756         int i;
 757
 758         for (i = 0; i < c->lpt_lebs; i++) {
 759                 if (i + c->lpt_first == c->nhead_lnum)
 760                         continue;
 761                 if (c->ltab[i].dirty > 0 &&
 762                     c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
 763                         c->ltab[i].tgc = 1;
 764                         c->ltab[i].free = c->leb_size;
 765                         c->ltab[i].dirty = 0;
 766                         dbg_lp("LEB %d", i + c->lpt_first);
 767                 }
 768         }
 769 }
 770
 771 /**
 772  * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
 773  * @c: UBIFS file-system description object
 774  *
 775  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
 776  * free space and so may be reused as soon as the next commit is completed.
 777  * This function is called after the commit is completed (master node has been
 778  * written) and un-maps LPT LEBs that were marked for trivial GC.
 779  */
 780 static int lpt_tgc_end(struct ubifs_info *c)
 781 {
 782         int i, err;
 783
 784         for (i = 0; i < c->lpt_lebs; i++)
 785                 if (c->ltab[i].tgc) {
 786                         err = ubifs_leb_unmap(c, i + c->lpt_first);
 787                         if (err)
 788                                 return err;
 789                         c->ltab[i].tgc = 0;
 790                         dbg_lp("LEB %d", i + c->lpt_first);
 791                 }
 792         return 0;
 793 }
 794
 795 /**
 796  * populate_lsave - fill the lsave array with important LEB numbers.
 797  * @c: the UBIFS file-system description object
 798  *
 799  * This function is only called for the "big" model. It records a small number
 800  * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
 801  * most important to least important): empty, freeable, freeable index, dirty
 802  * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
 803  * their pnodes into memory.  That will stop us from having to scan the LPT
 804  * straight away. For the "small" model we assume that scanning the LPT is no
 805  * big deal.
 806  */
 807 static void populate_lsave(struct ubifs_info *c)
 808 {
 809         struct ubifs_lprops *lprops;
 810         struct ubifs_lpt_heap *heap;
 811         int i, cnt = 0;
 812
 813         ubifs_assert(c->big_lpt);
 814         if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
 815                 c->lpt_drty_flgs |= LSAVE_DIRTY;
 816                 ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
 817         }
 818         list_for_each_entry(lprops, &c->empty_list, list) {
 819                 c->lsave[cnt++] = lprops->lnum;
 820                 if (cnt >= c->lsave_cnt)
 821                         return;
 822         }
 823         list_for_each_entry(lprops, &c->freeable_list, list) {
 824                 c->lsave[cnt++] = lprops->lnum;
 825                 if (cnt >= c->lsave_cnt)
 826                         return;
 827         }
 828         list_for_each_entry(lprops, &c->frdi_idx_list, list) {
 829                 c->lsave[cnt++] = lprops->lnum;
 830                 if (cnt >= c->lsave_cnt)
 831                         return;
 832         }
 833         heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
 834         for (i = 0; i < heap->cnt; i++) {
 835                 c->lsave[cnt++] = heap->arr[i]->lnum;
 836                 if (cnt >= c->lsave_cnt)
 837                         return;
 838         }
 839         heap = &c->lpt_heap[LPROPS_DIRTY - 1];
 840         for (i = 0; i < heap->cnt; i++) {
 841                 c->lsave[cnt++] = heap->arr[i]->lnum;
 842                 if (cnt >= c->lsave_cnt)
 843                         return;
 844         }
 845         heap = &c->lpt_heap[LPROPS_FREE - 1];
 846         for (i = 0; i < heap->cnt; i++) {
 847                 c->lsave[cnt++] = heap->arr[i]->lnum;
 848                 if (cnt >= c->lsave_cnt)
 849                         return;
 850         }
 851         /* Fill it up completely */
 852         while (cnt < c->lsave_cnt)
 853                 c->lsave[cnt++] = c->main_first;
 854 }
 855
 856 /**
 857  * nnode_lookup - lookup a nnode in the LPT.
 858  * @c: UBIFS file-system description object
 859  * @i: nnode number
 860  *
 861  * This function returns a pointer to the nnode on success or a negative
 862  * error code on failure.
 863  */
 864 static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
 865 {
 866         int err, iip;
 867         struct ubifs_nnode *nnode;
 868
 869         if (!c->nroot) {
 870                 err = ubifs_read_nnode(c, NULL, 0);
 871                 if (err)
 872                         return ERR_PTR(err);
 873         }
 874         nnode = c->nroot;
 875         while (1) {
 876                 iip = i & (UBIFS_LPT_FANOUT - 1);
 877                 i >>= UBIFS_LPT_FANOUT_SHIFT;
 878                 if (!i)
 879                         break;
 880                 nnode = ubifs_get_nnode(c, nnode, iip);
 881                 if (IS_ERR(nnode))
 882                         return nnode;
 883         }
 884         return nnode;
 885 }
 886
 887 /**
 888  * make_nnode_dirty - find a nnode and, if found, make it dirty.
 889  * @c: UBIFS file-system description object
 890  * @node_num: nnode number of nnode to make dirty
 891  * @lnum: LEB number where nnode was written
 892  * @offs: offset where nnode was written
 893  *
 894  * This function is used by LPT garbage collection.  LPT garbage collection is
 895  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 896  * simply involves marking all the nodes in the LEB being garbage-collected as
 897  * dirty.  The dirty nodes are written next commit, after which the LEB is free
 898  * to be reused.
 899  *
 900  * This function returns %0 on success and a negative error code on failure.
 901  */
 902 static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
 903                             int offs)
 904 {
 905         struct ubifs_nnode *nnode;
 906
 907         nnode = nnode_lookup(c, node_num);
 908         if (IS_ERR(nnode))
 909                 return PTR_ERR(nnode);
 910         if (nnode->parent) {
 911                 struct ubifs_nbranch *branch;
 912
 913                 branch = &nnode->parent->nbranch[nnode->iip];
 914                 if (branch->lnum != lnum || branch->offs != offs)
 915                         return 0; /* nnode is obsolete */
 916         } else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
 917                         return 0; /* nnode is obsolete */
 918         /* Assumes cnext list is empty i.e. not called during commit */
 919         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 920                 c->dirty_nn_cnt += 1;
 921                 ubifs_add_nnode_dirt(c, nnode);
 922                 /* Mark parent and ancestors dirty too */
 923                 nnode = nnode->parent;
 924                 while (nnode) {
 925                         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
 926                                 c->dirty_nn_cnt += 1;
 927                                 ubifs_add_nnode_dirt(c, nnode);
 928                                 nnode = nnode->parent;
 929                         } else
 930                                 break;
 931                 }
 932         }
 933         return 0;
 934 }
 935
 936 /**
 937  * make_pnode_dirty - find a pnode and, if found, make it dirty.
 938  * @c: UBIFS file-system description object
 939  * @node_num: pnode number of pnode to make dirty
 940  * @lnum: LEB number where pnode was written
 941  * @offs: offset where pnode was written
 942  *
 943  * This function is used by LPT garbage collection.  LPT garbage collection is
 944  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 945  * simply involves marking all the nodes in the LEB being garbage-collected as
 946  * dirty.  The dirty nodes are written next commit, after which the LEB is free
 947  * to be reused.
 948  *
 949  * This function returns %0 on success and a negative error code on failure.
 950  */
 951 static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
 952                             int offs)
 953 {
 954         struct ubifs_pnode *pnode;
 955         struct ubifs_nbranch *branch;
 956
 957         pnode = pnode_lookup(c, node_num);
 958         if (IS_ERR(pnode))
 959                 return PTR_ERR(pnode);
 960         branch = &pnode->parent->nbranch[pnode->iip];
 961         if (branch->lnum != lnum || branch->offs != offs)
 962                 return 0;
 963         do_make_pnode_dirty(c, pnode);
 964         return 0;
 965 }
 966
 967 /**
 968  * make_ltab_dirty - make ltab node dirty.
 969  * @c: UBIFS file-system description object
 970  * @lnum: LEB number where ltab was written
 971  * @offs: offset where ltab was written
 972  *
 973  * This function is used by LPT garbage collection.  LPT garbage collection is
 974  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
 975  * simply involves marking all the nodes in the LEB being garbage-collected as
 976  * dirty.  The dirty nodes are written next commit, after which the LEB is free
 977  * to be reused.
 978  *
 979  * This function returns %0 on success and a negative error code on failure.
 980  */
 981 static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
 982 {
 983         if (lnum != c->ltab_lnum || offs != c->ltab_offs)
 984                 return 0; /* This ltab node is obsolete */
 985         if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
 986                 c->lpt_drty_flgs |= LTAB_DIRTY;
 987                 ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
 988         }
 989         return 0;
 990 }
 991
 992 /**
 993  * make_lsave_dirty - make lsave node dirty.
 994  * @c: UBIFS file-system description object
 995  * @lnum: LEB number where lsave was written
 996  * @offs: offset where lsave was written
 997  *
 998  * This function is used by LPT garbage collection.  LPT garbage collection is
 999  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1000  * simply involves marking all the nodes in the LEB being garbage-collected as
1001  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1002  * to be reused.
1003  *
1004  * This function returns %0 on success and a negative error code on failure.
1005  */
1006 static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1007 {
1008         if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1009                 return 0; /* This lsave node is obsolete */
1010         if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
1011                 c->lpt_drty_flgs |= LSAVE_DIRTY;
1012                 ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
1013         }
1014         return 0;
1015 }
1016
1017 /**
1018  * make_node_dirty - make node dirty.
1019  * @c: UBIFS file-system description object
1020  * @node_type: LPT node type
1021  * @node_num: node number
1022  * @lnum: LEB number where node was written
1023  * @offs: offset where node was written
1024  *
1025  * This function is used by LPT garbage collection.  LPT garbage collection is
1026  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1027  * simply involves marking all the nodes in the LEB being garbage-collected as
1028  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1029  * to be reused.
1030  *
1031  * This function returns %0 on success and a negative error code on failure.
1032  */
1033 static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
1034                            int lnum, int offs)
1035 {
1036         switch (node_type) {
1037         case UBIFS_LPT_NNODE:
1038                 return make_nnode_dirty(c, node_num, lnum, offs);
1039         case UBIFS_LPT_PNODE:
1040                 return make_pnode_dirty(c, node_num, lnum, offs);
1041         case UBIFS_LPT_LTAB:
1042                 return make_ltab_dirty(c, lnum, offs);
1043         case UBIFS_LPT_LSAVE:
1044                 return make_lsave_dirty(c, lnum, offs);
1045         }
1046         return -EINVAL;
1047 }
1048
1049 /**
1050  * get_lpt_node_len - return the length of a node based on its type.
1051  * @c: UBIFS file-system description object
1052  * @node_type: LPT node type
1053  */
1054 static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
1055 {
1056         switch (node_type) {
1057         case UBIFS_LPT_NNODE:
1058                 return c->nnode_sz;
1059         case UBIFS_LPT_PNODE:
1060                 return c->pnode_sz;
1061         case UBIFS_LPT_LTAB:
1062                 return c->ltab_sz;
1063         case UBIFS_LPT_LSAVE:
1064                 return c->lsave_sz;
1065         }
1066         return 0;
1067 }
1068
1069 /**
1070  * get_pad_len - return the length of padding in a buffer.
1071  * @c: UBIFS file-system description object
1072  * @buf: buffer
1073  * @len: length of buffer
1074  */
1075 static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
1076 {
1077         int offs, pad_len;
1078
1079         if (c->min_io_size == 1)
1080                 return 0;
1081         offs = c->leb_size - len;
1082         pad_len = ALIGN(offs, c->min_io_size) - offs;
1083         return pad_len;
1084 }
1085
1086 /**
1087  * get_lpt_node_type - return type (and node number) of a node in a buffer.
1088  * @c: UBIFS file-system description object
1089  * @buf: buffer
1090  * @node_num: node number is returned here
1091  */
1092 static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
1093                              int *node_num)
1094 {
1095         uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1096         int pos = 0, node_type;
1097
1098         node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1099         *node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1100         return node_type;
1101 }
1102
1103 /**
1104  * is_a_node - determine if a buffer contains a node.
1105  * @c: UBIFS file-system description object
1106  * @buf: buffer
1107  * @len: length of buffer
1108  *
1109  * This function returns %1 if the buffer contains a node or %0 if it does not.
1110  */
1111 static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
1112 {
1113         uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1114         int pos = 0, node_type, node_len;
1115         uint16_t crc, calc_crc;
1116
1117         if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
1118                 return 0;
1119         node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1120         if (node_type == UBIFS_LPT_NOT_A_NODE)
1121                 return 0;
1122         node_len = get_lpt_node_len(c, node_type);
1123         if (!node_len || node_len > len)
1124                 return 0;
1125         pos = 0;
1126         addr = buf;
1127         crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
1128         calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
1129                          node_len - UBIFS_LPT_CRC_BYTES);
1130         if (crc != calc_crc)
1131                 return 0;
1132         return 1;
1133 }
1134
1135 /**
1136  * lpt_gc_lnum - garbage collect a LPT LEB.
1137  * @c: UBIFS file-system description object
1138  * @lnum: LEB number to garbage collect
1139  *
1140  * LPT garbage collection is used only for the "big" LPT model
1141  * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
1142  * in the LEB being garbage-collected as dirty.  The dirty nodes are written
1143  * next commit, after which the LEB is free to be reused.
1144  *
1145  * This function returns %0 on success and a negative error code on failure.
1146  */
1147 static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
1148 {
1149         int err, len = c->leb_size, node_type, node_num, node_len, offs;
1150         void *buf = c->lpt_buf;
1151
1152         dbg_lp("LEB %d", lnum);
1153         err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
1154         if (err) {
1155                 ubifs_err("cannot read LEB %d, error %d", lnum, err);
1156                 return err;
1157         }
1158         while (1) {
1159                 if (!is_a_node(c, buf, len)) {
1160                         int pad_len;
1161
1162                         pad_len = get_pad_len(c, buf, len);
1163                         if (pad_len) {
1164                                 buf += pad_len;
1165                                 len -= pad_len;
1166                                 continue;
1167                         }
1168                         return 0;
1169                 }
1170                 node_type = get_lpt_node_type(c, buf, &node_num);
1171                 node_len = get_lpt_node_len(c, node_type);
1172                 offs = c->leb_size - len;
1173                 ubifs_assert(node_len != 0);
1174                 mutex_lock(&c->lp_mutex);
1175                 err = make_node_dirty(c, node_type, node_num, lnum, offs);
1176                 mutex_unlock(&c->lp_mutex);
1177                 if (err)
1178                         return err;
1179                 buf += node_len;
1180                 len -= node_len;
1181         }
1182         return 0;
1183 }
1184
1185 /**
1186  * lpt_gc - LPT garbage collection.
1187  * @c: UBIFS file-system description object
1188  *
1189  * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
1190  * Returns %0 on success and a negative error code on failure.
1191  */
1192 static int lpt_gc(struct ubifs_info *c)
1193 {
1194         int i, lnum = -1, dirty = 0;
1195
1196         mutex_lock(&c->lp_mutex);
1197         for (i = 0; i < c->lpt_lebs; i++) {
1198                 ubifs_assert(!c->ltab[i].tgc);
1199                 if (i + c->lpt_first == c->nhead_lnum ||
1200                     c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
1201                         continue;
1202                 if (c->ltab[i].dirty > dirty) {
1203                         dirty = c->ltab[i].dirty;
1204                         lnum = i + c->lpt_first;
1205                 }
1206         }
1207         mutex_unlock(&c->lp_mutex);
1208         if (lnum == -1)
1209                 return -ENOSPC;
1210         return lpt_gc_lnum(c, lnum);
1211 }
1212
1213 /**
1214  * ubifs_lpt_start_commit - UBIFS commit starts.
1215  * @c: the UBIFS file-system description object
1216  *
1217  * This function has to be called when UBIFS starts the commit operation.
1218  * This function "freezes" all currently dirty LEB properties and does not
1219  * change them anymore. Further changes are saved and tracked separately
1220  * because they are not part of this commit. This function returns zero in case
1221  * of success and a negative error code in case of failure.
1222  */
1223 int ubifs_lpt_start_commit(struct ubifs_info *c)
1224 {
1225         int err, cnt;
1226
1227         dbg_lp("");
1228
1229         mutex_lock(&c->lp_mutex);
1230         err = dbg_chk_lpt_free_spc(c);
1231         if (err)
1232                 goto out;
1233         err = dbg_check_ltab(c);
1234         if (err)
1235                 goto out;
1236
1237         if (c->check_lpt_free) {
1238                 /*
1239                  * We ensure there is enough free space in
1240                  * ubifs_lpt_post_commit() by marking nodes dirty. That
1241                  * information is lost when we unmount, so we also need
1242                  * to check free space once after mounting also.
1243                  */
1244                 c->check_lpt_free = 0;
1245                 while (need_write_all(c)) {
1246                         mutex_unlock(&c->lp_mutex);
1247                         err = lpt_gc(c);
1248                         if (err)
1249                                 return err;
1250                         mutex_lock(&c->lp_mutex);
1251                 }
1252         }
1253
1254         lpt_tgc_start(c);
1255
1256         if (!c->dirty_pn_cnt) {
1257                 dbg_cmt("no cnodes to commit");
1258                 err = 0;
1259                 goto out;
1260         }
1261
1262         if (!c->big_lpt && need_write_all(c)) {
1263                 /* If needed, write everything */
1264                 err = make_tree_dirty(c);
1265                 if (err)
1266                         goto out;
1267                 lpt_tgc_start(c);
1268         }
1269
1270         if (c->big_lpt)
1271                 populate_lsave(c);
1272
1273         cnt = get_cnodes_to_commit(c);
1274         ubifs_assert(cnt != 0);
1275
1276         err = layout_cnodes(c);
1277         if (err)
1278                 goto out;
1279
1280         /* Copy the LPT's own lprops for end commit to write */
1281         memcpy(c->ltab_cmt, c->ltab,
1282                sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1283         c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
1284
1285 out:
1286         mutex_unlock(&c->lp_mutex);
1287         return err;
1288 }
1289
1290 /**
1291  * free_obsolete_cnodes - free obsolete cnodes for commit end.
1292  * @c: UBIFS file-system description object
1293  */
1294 static void free_obsolete_cnodes(struct ubifs_info *c)
1295 {
1296         struct ubifs_cnode *cnode, *cnext;
1297
1298         cnext = c->lpt_cnext;
1299         if (!cnext)
1300                 return;
1301         do {
1302                 cnode = cnext;
1303                 cnext = cnode->cnext;
1304                 if (test_bit(OBSOLETE_CNODE, &cnode->flags))
1305                         kfree(cnode);
1306                 else
1307                         cnode->cnext = NULL;
1308         } while (cnext != c->lpt_cnext);
1309         c->lpt_cnext = NULL;
1310 }
1311
1312 /**
1313  * ubifs_lpt_end_commit - finish the commit operation.
1314  * @c: the UBIFS file-system description object
1315  *
1316  * This function has to be called when the commit operation finishes. It
1317  * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1318  * the media. Returns zero in case of success and a negative error code in case
1319  * of failure.
1320  */
1321 int ubifs_lpt_end_commit(struct ubifs_info *c)
1322 {
1323         int err;
1324
1325         dbg_lp("");
1326
1327         if (!c->lpt_cnext)
1328                 return 0;
1329
1330         err = write_cnodes(c);
1331         if (err)
1332                 return err;
1333
1334         mutex_lock(&c->lp_mutex);
1335         free_obsolete_cnodes(c);
1336         mutex_unlock(&c->lp_mutex);
1337
1338         return 0;
1339 }
1340
1341 /**
1342  * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1343  * @c: UBIFS file-system description object
1344  *
1345  * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1346  * commit for the "big" LPT model.
1347  */
1348 int ubifs_lpt_post_commit(struct ubifs_info *c)
1349 {
1350         int err;
1351
1352         mutex_lock(&c->lp_mutex);
1353         err = lpt_tgc_end(c);
1354         if (err)
1355                 goto out;
1356         if (c->big_lpt)
1357                 while (need_write_all(c)) {
1358                         mutex_unlock(&c->lp_mutex);
1359                         err = lpt_gc(c);
1360                         if (err)
1361                                 return err;
1362                         mutex_lock(&c->lp_mutex);
1363                 }
1364 out:
1365         mutex_unlock(&c->lp_mutex);
1366         return err;
1367 }
1368
1369 /**
1370  * first_nnode - find the first nnode in memory.
1371  * @c: UBIFS file-system description object
1372  * @hght: height of tree where nnode found is returned here
1373  *
1374  * This function returns a pointer to the nnode found or %NULL if no nnode is
1375  * found. This function is a helper to 'ubifs_lpt_free()'.
1376  */
1377 static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1378 {
1379         struct ubifs_nnode *nnode;
1380         int h, i, found;
1381
1382         nnode = c->nroot;
1383         *hght = 0;
1384         if (!nnode)
1385                 return NULL;
1386         for (h = 1; h < c->lpt_hght; h++) {
1387                 found = 0;
1388                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1389                         if (nnode->nbranch[i].nnode) {
1390                                 found = 1;
1391                                 nnode = nnode->nbranch[i].nnode;
1392                                 *hght = h;
1393                                 break;
1394                         }
1395                 }
1396                 if (!found)
1397                         break;
1398         }
1399         return nnode;
1400 }
1401
1402 /**
1403  * next_nnode - find the next nnode in memory.
1404  * @c: UBIFS file-system description object
1405  * @nnode: nnode from which to start.
1406  * @hght: height of tree where nnode is, is passed and returned here
1407  *
1408  * This function returns a pointer to the nnode found or %NULL if no nnode is
1409  * found. This function is a helper to 'ubifs_lpt_free()'.
1410  */
1411 static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1412                                       struct ubifs_nnode *nnode, int *hght)
1413 {
1414         struct ubifs_nnode *parent;
1415         int iip, h, i, found;
1416
1417         parent = nnode->parent;
1418         if (!parent)
1419                 return NULL;
1420         if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1421                 *hght -= 1;
1422                 return parent;
1423         }
1424         for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1425                 nnode = parent->nbranch[iip].nnode;
1426                 if (nnode)
1427                         break;
1428         }
1429         if (!nnode) {
1430                 *hght -= 1;
1431                 return parent;
1432         }
1433         for (h = *hght + 1; h < c->lpt_hght; h++) {
1434                 found = 0;
1435                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1436                         if (nnode->nbranch[i].nnode) {
1437                                 found = 1;
1438                                 nnode = nnode->nbranch[i].nnode;
1439                                 *hght = h;
1440                                 break;
1441                         }
1442                 }
1443                 if (!found)
1444                         break;
1445         }
1446         return nnode;
1447 }
1448
1449 /**
1450  * ubifs_lpt_free - free resources owned by the LPT.
1451  * @c: UBIFS file-system description object
1452  * @wr_only: free only resources used for writing
1453  */
1454 void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1455 {
1456         struct ubifs_nnode *nnode;
1457         int i, hght;
1458
1459         /* Free write-only things first */
1460
1461         free_obsolete_cnodes(c); /* Leftover from a failed commit */
1462
1463         vfree(c->ltab_cmt);
1464         c->ltab_cmt = NULL;
1465         vfree(c->lpt_buf);
1466         c->lpt_buf = NULL;
1467         kfree(c->lsave);
1468         c->lsave = NULL;
1469
1470         if (wr_only)
1471                 return;
1472
1473         /* Now free the rest */
1474
1475         nnode = first_nnode(c, &hght);
1476         while (nnode) {
1477                 for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1478                         kfree(nnode->nbranch[i].nnode);
1479                 nnode = next_nnode(c, nnode, &hght);
1480         }
1481         for (i = 0; i < LPROPS_HEAP_CNT; i++)
1482                 kfree(c->lpt_heap[i].arr);
1483         kfree(c->dirty_idx.arr);
1484         kfree(c->nroot);
1485         vfree(c->ltab);
1486         kfree(c->lpt_nod_buf);
1487 }
1488
1489 #ifdef CONFIG_UBIFS_FS_DEBUG
1490
1491 /**
1492  * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1493  * @buf: buffer
1494  * @len: buffer length
1495  */
1496 static int dbg_is_all_ff(uint8_t *buf, int len)
1497 {
1498         int i;
1499
1500         for (i = 0; i < len; i++)
1501                 if (buf[i] != 0xff)
1502                         return 0;
1503         return 1;
1504 }
1505
1506 /**
1507  * dbg_is_nnode_dirty - determine if a nnode is dirty.
1508  * @c: the UBIFS file-system description object
1509  * @lnum: LEB number where nnode was written
1510  * @offs: offset where nnode was written
1511  */
1512 static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1513 {
1514         struct ubifs_nnode *nnode;
1515         int hght;
1516
1517         /* Entire tree is in memory so first_nnode / next_nnode are OK */
1518         nnode = first_nnode(c, &hght);
1519         for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1520                 struct ubifs_nbranch *branch;
1521
1522                 cond_resched();
1523                 if (nnode->parent) {
1524                         branch = &nnode->parent->nbranch[nnode->iip];
1525                         if (branch->lnum != lnum || branch->offs != offs)
1526                                 continue;
1527                         if (test_bit(DIRTY_CNODE, &nnode->flags))
1528                                 return 1;
1529                         return 0;
1530                 } else {
1531                         if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1532                                 continue;
1533                         if (test_bit(DIRTY_CNODE, &nnode->flags))
1534                                 return 1;
1535                         return 0;
1536                 }
1537         }
1538         return 1;
1539 }
1540
1541 /**
1542  * dbg_is_pnode_dirty - determine if a pnode is dirty.
1543  * @c: the UBIFS file-system description object
1544  * @lnum: LEB number where pnode was written
1545  * @offs: offset where pnode was written
1546  */
1547 static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1548 {
1549         int i, cnt;
1550
1551         cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1552         for (i = 0; i < cnt; i++) {
1553                 struct ubifs_pnode *pnode;
1554                 struct ubifs_nbranch *branch;
1555
1556                 cond_resched();
1557                 pnode = pnode_lookup(c, i);
1558                 if (IS_ERR(pnode))
1559                         return PTR_ERR(pnode);
1560                 branch = &pnode->parent->nbranch[pnode->iip];
1561                 if (branch->lnum != lnum || branch->offs != offs)
1562                         continue;
1563                 if (test_bit(DIRTY_CNODE, &pnode->flags))
1564                         return 1;
1565                 return 0;
1566         }
1567         return 1;
1568 }
1569
1570 /**
1571  * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1572  * @c: the UBIFS file-system description object
1573  * @lnum: LEB number where ltab node was written
1574  * @offs: offset where ltab node was written
1575  */
1576 static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1577 {
1578         if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1579                 return 1;
1580         return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1581 }
1582
1583 /**
1584  * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1585  * @c: the UBIFS file-system description object
1586  * @lnum: LEB number where lsave node was written
1587  * @offs: offset where lsave node was written
1588  */
1589 static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1590 {
1591         if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1592                 return 1;
1593         return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1594 }
1595
1596 /**
1597  * dbg_is_node_dirty - determine if a node is dirty.
1598  * @c: the UBIFS file-system description object
1599  * @node_type: node type
1600  * @lnum: LEB number where node was written
1601  * @offs: offset where node was written
1602  */
1603 static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1604                              int offs)
1605 {
1606         switch (node_type) {
1607         case UBIFS_LPT_NNODE:
1608                 return dbg_is_nnode_dirty(c, lnum, offs);
1609         case UBIFS_LPT_PNODE:
1610                 return dbg_is_pnode_dirty(c, lnum, offs);
1611         case UBIFS_LPT_LTAB:
1612                 return dbg_is_ltab_dirty(c, lnum, offs);
1613         case UBIFS_LPT_LSAVE:
1614                 return dbg_is_lsave_dirty(c, lnum, offs);
1615         }
1616         return 1;
1617 }
1618
1619 /**
1620  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1621  * @c: the UBIFS file-system description object
1622  * @lnum: LEB number where node was written
1623  * @offs: offset where node was written
1624  *
1625  * This function returns %0 on success and a negative error code on failure.
1626  */
1627 static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1628 {
1629         int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1630         int ret;
1631         void *buf = c->dbg->buf;
1632
1633         if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
1634                 return 0;
1635
1636         dbg_lp("LEB %d", lnum);
1637         err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
1638         if (err) {
1639                 dbg_msg("ubi_read failed, LEB %d, error %d", lnum, err);
1640                 return err;
1641         }
1642         while (1) {
1643                 if (!is_a_node(c, buf, len)) {
1644                         int i, pad_len;
1645
1646                         pad_len = get_pad_len(c, buf, len);
1647                         if (pad_len) {
1648                                 buf += pad_len;
1649                                 len -= pad_len;
1650                                 dirty += pad_len;
1651                                 continue;
1652                         }
1653                         if (!dbg_is_all_ff(buf, len)) {
1654                                 dbg_msg("invalid empty space in LEB %d at %d",
1655                                         lnum, c->leb_size - len);
1656                                 err = -EINVAL;
1657                         }
1658                         i = lnum - c->lpt_first;
1659                         if (len != c->ltab[i].free) {
1660                                 dbg_msg("invalid free space in LEB %d "
1661                                         "(free %d, expected %d)",
1662                                         lnum, len, c->ltab[i].free);
1663                                 err = -EINVAL;
1664                         }
1665                         if (dirty != c->ltab[i].dirty) {
1666                                 dbg_msg("invalid dirty space in LEB %d "
1667                                         "(dirty %d, expected %d)",
1668                                         lnum, dirty, c->ltab[i].dirty);
1669                                 err = -EINVAL;
1670                         }
1671                         return err;
1672                 }
1673                 node_type = get_lpt_node_type(c, buf, &node_num);
1674                 node_len = get_lpt_node_len(c, node_type);
1675                 ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1676                 if (ret == 1)
1677                         dirty += node_len;
1678                 buf += node_len;
1679                 len -= node_len;
1680         }
1681 }
1682
1683 /**
1684  * dbg_check_ltab - check the free and dirty space in the ltab.
1685  * @c: the UBIFS file-system description object
1686  *
1687  * This function returns %0 on success and a negative error code on failure.
1688  */
1689 int dbg_check_ltab(struct ubifs_info *c)
1690 {
1691         int lnum, err, i, cnt;
1692
1693         if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
1694                 return 0;
1695
1696         /* Bring the entire tree into memory */
1697         cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1698         for (i = 0; i < cnt; i++) {
1699                 struct ubifs_pnode *pnode;
1700
1701                 pnode = pnode_lookup(c, i);
1702                 if (IS_ERR(pnode))
1703                         return PTR_ERR(pnode);
1704                 cond_resched();
1705         }
1706
1707         /* Check nodes */
1708         err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1709         if (err)
1710                 return err;
1711
1712         /* Check each LEB */
1713         for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1714                 err = dbg_check_ltab_lnum(c, lnum);
1715                 if (err) {
1716                         dbg_err("failed at LEB %d", lnum);
1717                         return err;
1718                 }
1719         }
1720
1721         dbg_lp("succeeded");
1722         return 0;
1723 }
1724
1725 /**
1726  * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1727  * @c: the UBIFS file-system description object
1728  *
1729  * This function returns %0 on success and a negative error code on failure.
1730  */
1731 int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1732 {
1733         long long free = 0;
1734         int i;
1735
1736         if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
1737                 return 0;
1738
1739         for (i = 0; i < c->lpt_lebs; i++) {
1740                 if (c->ltab[i].tgc || c->ltab[i].cmt)
1741                         continue;
1742                 if (i + c->lpt_first == c->nhead_lnum)
1743                         free += c->leb_size - c->nhead_offs;
1744                 else if (c->ltab[i].free == c->leb_size)
1745                         free += c->leb_size;
1746         }
1747         if (free < c->lpt_sz) {
1748                 dbg_err("LPT space error: free %lld lpt_sz %lld",
1749                         free, c->lpt_sz);
1750                 dbg_dump_lpt_info(c);
1751                 dbg_dump_lpt_lebs(c);
1752                 dump_stack();
1753                 return -EINVAL;
1754         }
1755         return 0;
1756 }
1757
1758 /**
1759  * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1760  * @c: the UBIFS file-system description object
1761  * @action: what to do
1762  * @len: length written
1763  *
1764  * This function returns %0 on success and a negative error code on failure.
1765  * The @action argument may be one of:
1766  *   o %0 - LPT debugging checking starts, initialize debugging variables;
1767  *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1768  *   o %2 - switched to a different LEB and wasted @len bytes;
1769  *   o %3 - check that we've written the right number of bytes.
1770  *   o %4 - wasted @len bytes;
1771  */
1772 int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1773 {
1774         struct ubifs_debug_info *d = c->dbg;
1775         long long chk_lpt_sz, lpt_sz;
1776         int err = 0;
1777
1778         if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
1779                 return 0;
1780
1781         switch (action) {
1782         case 0:
1783                 d->chk_lpt_sz = 0;
1784                 d->chk_lpt_sz2 = 0;
1785                 d->chk_lpt_lebs = 0;
1786                 d->chk_lpt_wastage = 0;
1787                 if (c->dirty_pn_cnt > c->pnode_cnt) {
1788                         dbg_err("dirty pnodes %d exceed max %d",
1789                                 c->dirty_pn_cnt, c->pnode_cnt);
1790                         err = -EINVAL;
1791                 }
1792                 if (c->dirty_nn_cnt > c->nnode_cnt) {
1793                         dbg_err("dirty nnodes %d exceed max %d",
1794                                 c->dirty_nn_cnt, c->nnode_cnt);
1795                         err = -EINVAL;
1796                 }
1797                 return err;
1798         case 1:
1799                 d->chk_lpt_sz += len;
1800                 return 0;
1801         case 2:
1802                 d->chk_lpt_sz += len;
1803                 d->chk_lpt_wastage += len;
1804                 d->chk_lpt_lebs += 1;
1805                 return 0;
1806         case 3:
1807                 chk_lpt_sz = c->leb_size;
1808                 chk_lpt_sz *= d->chk_lpt_lebs;
1809                 chk_lpt_sz += len - c->nhead_offs;
1810                 if (d->chk_lpt_sz != chk_lpt_sz) {
1811                         dbg_err("LPT wrote %lld but space used was %lld",
1812                                 d->chk_lpt_sz, chk_lpt_sz);
1813                         err = -EINVAL;
1814                 }
1815                 if (d->chk_lpt_sz > c->lpt_sz) {
1816                         dbg_err("LPT wrote %lld but lpt_sz is %lld",
1817                                 d->chk_lpt_sz, c->lpt_sz);
1818                         err = -EINVAL;
1819                 }
1820                 if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1821                         dbg_err("LPT layout size %lld but wrote %lld",
1822                                 d->chk_lpt_sz, d->chk_lpt_sz2);
1823                         err = -EINVAL;
1824                 }
1825                 if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1826                         dbg_err("LPT new nhead offs: expected %d was %d",
1827                                 d->new_nhead_offs, len);
1828                         err = -EINVAL;
1829                 }
1830                 lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1831                 lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1832                 lpt_sz += c->ltab_sz;
1833                 if (c->big_lpt)
1834                         lpt_sz += c->lsave_sz;
1835                 if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1836                         dbg_err("LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1837                                 d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1838                         err = -EINVAL;
1839                 }
1840                 if (err) {
1841                         dbg_dump_lpt_info(c);
1842                         dbg_dump_lpt_lebs(c);
1843                         dump_stack();
1844                 }
1845                 d->chk_lpt_sz2 = d->chk_lpt_sz;
1846                 d->chk_lpt_sz = 0;
1847                 d->chk_lpt_wastage = 0;
1848                 d->chk_lpt_lebs = 0;
1849                 d->new_nhead_offs = len;
1850                 return err;
1851         case 4:
1852                 d->chk_lpt_sz += len;
1853                 d->chk_lpt_wastage += len;
1854                 return 0;
1855         default:
1856                 return -EINVAL;
1857         }
1858 }
1859
1860 /**
1861  * dbg_dump_lpt_leb - dump an LPT LEB.
1862  * @c: UBIFS file-system description object
1863  * @lnum: LEB number to dump
1864  *
1865  * This function dumps an LEB from LPT area. Nodes in this area are very
1866  * different to nodes in the main area (e.g., they do not have common headers,
1867  * they do not have 8-byte alignments, etc), so we have a separate function to
1868  * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1869  */
1870 static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1871 {
1872         int err, len = c->leb_size, node_type, node_num, node_len, offs;
1873         void *buf = c->dbg->buf;
1874
1875         printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
1876                current->pid, lnum);
1877         err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
1878         if (err) {
1879                 ubifs_err("cannot read LEB %d, error %d", lnum, err);
1880                 return;
1881         }
1882         while (1) {
1883                 offs = c->leb_size - len;
1884                 if (!is_a_node(c, buf, len)) {
1885                         int pad_len;
1886
1887                         pad_len = get_pad_len(c, buf, len);
1888                         if (pad_len) {
1889                                 printk(KERN_DEBUG "LEB %d:%d, pad %d bytes\n",
1890                                        lnum, offs, pad_len);
1891                                 buf += pad_len;
1892                                 len -= pad_len;
1893                                 continue;
1894                         }
1895                         if (len)
1896                                 printk(KERN_DEBUG "LEB %d:%d, free %d bytes\n",
1897                                        lnum, offs, len);
1898                         break;
1899                 }
1900
1901                 node_type = get_lpt_node_type(c, buf, &node_num);
1902                 switch (node_type) {
1903                 case UBIFS_LPT_PNODE:
1904                 {
1905                         node_len = c->pnode_sz;
1906                         if (c->big_lpt)
1907                                 printk(KERN_DEBUG "LEB %d:%d, pnode num %d\n",
1908                                        lnum, offs, node_num);
1909                         else
1910                                 printk(KERN_DEBUG "LEB %d:%d, pnode\n",
1911                                        lnum, offs);
1912                         break;
1913                 }
1914                 case UBIFS_LPT_NNODE:
1915                 {
1916                         int i;
1917                         struct ubifs_nnode nnode;
1918
1919                         node_len = c->nnode_sz;
1920                         if (c->big_lpt)
1921                                 printk(KERN_DEBUG "LEB %d:%d, nnode num %d, ",
1922                                        lnum, offs, node_num);
1923                         else
1924                                 printk(KERN_DEBUG "LEB %d:%d, nnode, ",
1925                                        lnum, offs);
1926                         err = ubifs_unpack_nnode(c, buf, &nnode);
1927                         for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1928                                 printk(KERN_CONT "%d:%d", nnode.nbranch[i].lnum,
1929                                        nnode.nbranch[i].offs);
1930                                 if (i != UBIFS_LPT_FANOUT - 1)
1931                                         printk(KERN_CONT ", ");
1932                         }
1933                         printk(KERN_CONT "\n");
1934                         break;
1935                 }
1936                 case UBIFS_LPT_LTAB:
1937                         node_len = c->ltab_sz;
1938                         printk(KERN_DEBUG "LEB %d:%d, ltab\n",
1939                                lnum, offs);
1940                         break;
1941                 case UBIFS_LPT_LSAVE:
1942                         node_len = c->lsave_sz;
1943                         printk(KERN_DEBUG "LEB %d:%d, lsave len\n", lnum, offs);
1944                         break;
1945                 default:
1946                         ubifs_err("LPT node type %d not recognized", node_type);
1947                         return;
1948                 }
1949
1950                 buf += node_len;
1951                 len -= node_len;
1952         }
1953
1954         printk(KERN_DEBUG "(pid %d) finish dumping LEB %d\n",
1955                current->pid, lnum);
1956 }
1957
1958 /**
1959  * dbg_dump_lpt_lebs - dump LPT lebs.
1960  * @c: UBIFS file-system description object
1961  *
1962  * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1963  * locked.
1964  */
1965 void dbg_dump_lpt_lebs(const struct ubifs_info *c)
1966 {
1967         int i;
1968
1969         printk(KERN_DEBUG "(pid %d) start dumping all LPT LEBs\n",
1970                current->pid);
1971         for (i = 0; i < c->lpt_lebs; i++)
1972                 dump_lpt_leb(c, i + c->lpt_first);
1973         printk(KERN_DEBUG "(pid %d) finish dumping all LPT LEBs\n",
1974                current->pid);
1975 }
1976
1977 #endif /* CONFIG_UBIFS_FS_DEBUG */