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