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