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TOMOYO Linux Cross Reference
Linux/fs/ubifs/lpt_commit.c

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  1 /*
  2  * This file is part of UBIFS.
  3  *
  4  * Copyright (C) 2006-2008 Nokia Corporation.
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 as published by
  8  * the Free Software Foundation.
  9  *
 10  * This program is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13  * more details.
 14  *
 15  * You should have received a copy of the GNU General Public License along with
 16  * this program; if not, write to the Free Software Foundation, Inc., 51
 17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 18  *
 19  * Authors: Adrian Hunter
 20  *          Artem Bityutskiy (Битюцкий Артём)
 21  */
 22 
 23 /*
 24  * This file implements commit-related functionality of the LEB properties
 25  * subsystem.
 26  */
 27 
 28 #include <linux/crc16.h>
 29 #include <linux/slab.h>
 30 #include <linux/random.h>
 31 #include "ubifs.h"
 32 
 33 static int dbg_populate_lsave(struct ubifs_info *c);
 34 
 35 /**
 36  * first_dirty_cnode - find first dirty cnode.
 37  * @c: UBIFS file-system description object
 38  * @nnode: nnode at which to start
 39  *
 40  * This function returns the first dirty cnode or %NULL if there is not one.
 41  */
 42 static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
 43 {
 44         ubifs_assert(nnode);
 45         while (1) {
 46                 int i, cont = 0;
 47 
 48                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
 49                         struct ubifs_cnode *cnode;
 50 
 51                         cnode = nnode->nbranch[i].cnode;
 52                         if (cnode &&
 53                             test_bit(DIRTY_CNODE, &cnode->flags)) {
 54                                 if (cnode->level == 0)
 55                                         return cnode;
 56                                 nnode = (struct ubifs_nnode *)cnode;
 57                                 cont = 1;
 58                                 break;
 59                         }
 60                 }
 61                 if (!cont)
 62                         return (struct ubifs_cnode *)nnode;
 63         }
 64 }
 65 
 66 /**
 67  * next_dirty_cnode - find next dirty cnode.
 68  * @cnode: cnode from which to begin searching
 69  *
 70  * This function returns the next dirty cnode or %NULL if there is not one.
 71  */
 72 static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
 73 {
 74         struct ubifs_nnode *nnode;
 75         int i;
 76 
 77         ubifs_assert(cnode);
 78         nnode = cnode->parent;
 79         if (!nnode)
 80                 return NULL;
 81         for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
 82                 cnode = nnode->nbranch[i].cnode;
 83                 if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
 84                         if (cnode->level == 0)
 85                                 return cnode; /* cnode is a pnode */
 86                         /* cnode is a nnode */
 87                         return first_dirty_cnode((struct ubifs_nnode *)cnode);
 88                 }
 89         }
 90         return (struct ubifs_cnode *)nnode;
 91 }
 92 
 93 /**
 94  * get_cnodes_to_commit - create list of dirty cnodes to commit.
 95  * @c: UBIFS file-system description object
 96  *
 97  * This function returns the number of cnodes to commit.
 98  */
 99 static int get_cnodes_to_commit(struct ubifs_info *c)
100 {
101         struct ubifs_cnode *cnode, *cnext;
102         int cnt = 0;
103 
104         if (!c->nroot)
105                 return 0;
106 
107         if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
108                 return 0;
109 
110         c->lpt_cnext = first_dirty_cnode(c->nroot);
111         cnode = c->lpt_cnext;
112         if (!cnode)
113                 return 0;
114         cnt += 1;
115         while (1) {
116                 ubifs_assert(!test_bit(COW_CNODE, &cnode->flags));
117                 __set_bit(COW_CNODE, &cnode->flags);
118                 cnext = next_dirty_cnode(cnode);
119                 if (!cnext) {
120                         cnode->cnext = c->lpt_cnext;
121                         break;
122                 }
123                 cnode->cnext = cnext;
124                 cnode = cnext;
125                 cnt += 1;
126         }
127         dbg_cmt("committing %d cnodes", cnt);
128         dbg_lp("committing %d cnodes", cnt);
129         ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
130         return cnt;
131 }
132 
133 /**
134  * upd_ltab - update LPT LEB properties.
135  * @c: UBIFS file-system description object
136  * @lnum: LEB number
137  * @free: amount of free space
138  * @dirty: amount of dirty space to add
139  */
140 static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
141 {
142         dbg_lp("LEB %d free %d dirty %d to %d +%d",
143                lnum, c->ltab[lnum - c->lpt_first].free,
144                c->ltab[lnum - c->lpt_first].dirty, free, dirty);
145         ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
146         c->ltab[lnum - c->lpt_first].free = free;
147         c->ltab[lnum - c->lpt_first].dirty += dirty;
148 }
149 
150 /**
151  * alloc_lpt_leb - allocate an LPT LEB that is empty.
152  * @c: UBIFS file-system description object
153  * @lnum: LEB number is passed and returned here
154  *
155  * This function finds the next empty LEB in the ltab starting from @lnum. If a
156  * an empty LEB is found it is returned in @lnum and the function returns %0.
157  * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
158  * never to run out of space.
159  */
160 static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
161 {
162         int i, n;
163 
164         n = *lnum - c->lpt_first + 1;
165         for (i = n; i < c->lpt_lebs; i++) {
166                 if (c->ltab[i].tgc || c->ltab[i].cmt)
167                         continue;
168                 if (c->ltab[i].free == c->leb_size) {
169                         c->ltab[i].cmt = 1;
170                         *lnum = i + c->lpt_first;
171                         return 0;
172                 }
173         }
174 
175         for (i = 0; i < n; i++) {
176                 if (c->ltab[i].tgc || c->ltab[i].cmt)
177                         continue;
178                 if (c->ltab[i].free == c->leb_size) {
179                         c->ltab[i].cmt = 1;
180                         *lnum = i + c->lpt_first;
181                         return 0;
182                 }
183         }
184         return -ENOSPC;
185 }
186 
187 /**
188  * layout_cnodes - layout cnodes for commit.
189  * @c: UBIFS file-system description object
190  *
191  * This function returns %0 on success and a negative error code on failure.
192  */
193 static int layout_cnodes(struct ubifs_info *c)
194 {
195         int lnum, offs, len, alen, done_lsave, done_ltab, err;
196         struct ubifs_cnode *cnode;
197 
198         err = dbg_chk_lpt_sz(c, 0, 0);
199         if (err)
200                 return err;
201         cnode = c->lpt_cnext;
202         if (!cnode)
203                 return 0;
204         lnum = c->nhead_lnum;
205         offs = c->nhead_offs;
206         /* Try to place lsave and ltab nicely */
207         done_lsave = !c->big_lpt;
208         done_ltab = 0;
209         if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
210                 done_lsave = 1;
211                 c->lsave_lnum = lnum;
212                 c->lsave_offs = offs;
213                 offs += c->lsave_sz;
214                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
215         }
216 
217         if (offs + c->ltab_sz <= c->leb_size) {
218                 done_ltab = 1;
219                 c->ltab_lnum = lnum;
220                 c->ltab_offs = offs;
221                 offs += c->ltab_sz;
222                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
223         }
224 
225         do {
226                 if (cnode->level) {
227                         len = c->nnode_sz;
228                         c->dirty_nn_cnt -= 1;
229                 } else {
230                         len = c->pnode_sz;
231                         c->dirty_pn_cnt -= 1;
232                 }
233                 while (offs + len > c->leb_size) {
234                         alen = ALIGN(offs, c->min_io_size);
235                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
236                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
237                         err = alloc_lpt_leb(c, &lnum);
238                         if (err)
239                                 goto no_space;
240                         offs = 0;
241                         ubifs_assert(lnum >= c->lpt_first &&
242                                      lnum <= c->lpt_last);
243                         /* Try to place lsave and ltab nicely */
244                         if (!done_lsave) {
245                                 done_lsave = 1;
246                                 c->lsave_lnum = lnum;
247                                 c->lsave_offs = offs;
248                                 offs += c->lsave_sz;
249                                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
250                                 continue;
251                         }
252                         if (!done_ltab) {
253                                 done_ltab = 1;
254                                 c->ltab_lnum = lnum;
255                                 c->ltab_offs = offs;
256                                 offs += c->ltab_sz;
257                                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
258                                 continue;
259                         }
260                         break;
261                 }
262                 if (cnode->parent) {
263                         cnode->parent->nbranch[cnode->iip].lnum = lnum;
264                         cnode->parent->nbranch[cnode->iip].offs = offs;
265                 } else {
266                         c->lpt_lnum = lnum;
267                         c->lpt_offs = offs;
268                 }
269                 offs += len;
270                 dbg_chk_lpt_sz(c, 1, len);
271                 cnode = cnode->cnext;
272         } while (cnode && cnode != c->lpt_cnext);
273 
274         /* Make sure to place LPT's save table */
275         if (!done_lsave) {
276                 if (offs + c->lsave_sz > c->leb_size) {
277                         alen = ALIGN(offs, c->min_io_size);
278                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
279                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
280                         err = alloc_lpt_leb(c, &lnum);
281                         if (err)
282                                 goto no_space;
283                         offs = 0;
284                         ubifs_assert(lnum >= c->lpt_first &&
285                                      lnum <= c->lpt_last);
286                 }
287                 done_lsave = 1;
288                 c->lsave_lnum = lnum;
289                 c->lsave_offs = offs;
290                 offs += c->lsave_sz;
291                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
292         }
293 
294         /* Make sure to place LPT's own lprops table */
295         if (!done_ltab) {
296                 if (offs + c->ltab_sz > c->leb_size) {
297                         alen = ALIGN(offs, c->min_io_size);
298                         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
299                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
300                         err = alloc_lpt_leb(c, &lnum);
301                         if (err)
302                                 goto no_space;
303                         offs = 0;
304                         ubifs_assert(lnum >= c->lpt_first &&
305                                      lnum <= c->lpt_last);
306                 }
307                 c->ltab_lnum = lnum;
308                 c->ltab_offs = offs;
309                 offs += c->ltab_sz;
310                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
311         }
312 
313         alen = ALIGN(offs, c->min_io_size);
314         upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
315         dbg_chk_lpt_sz(c, 4, alen - offs);
316         err = dbg_chk_lpt_sz(c, 3, alen);
317         if (err)
318                 return err;
319         return 0;
320 
321 no_space:
322         ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
323                   lnum, offs, len, done_ltab, done_lsave);
324         ubifs_dump_lpt_info(c);
325         ubifs_dump_lpt_lebs(c);
326         dump_stack();
327         return err;
328 }
329 
330 /**
331  * realloc_lpt_leb - allocate an LPT LEB that is empty.
332  * @c: UBIFS file-system description object
333  * @lnum: LEB number is passed and returned here
334  *
335  * This function duplicates exactly the results of the function alloc_lpt_leb.
336  * It is used during end commit to reallocate the same LEB numbers that were
337  * allocated by alloc_lpt_leb during start commit.
338  *
339  * This function finds the next LEB that was allocated by the alloc_lpt_leb
340  * function starting from @lnum. If a LEB is found it is returned in @lnum and
341  * the function returns %0. Otherwise the function returns -ENOSPC.
342  * Note however, that LPT is designed never to run out of space.
343  */
344 static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
345 {
346         int i, n;
347 
348         n = *lnum - c->lpt_first + 1;
349         for (i = n; i < c->lpt_lebs; i++)
350                 if (c->ltab[i].cmt) {
351                         c->ltab[i].cmt = 0;
352                         *lnum = i + c->lpt_first;
353                         return 0;
354                 }
355 
356         for (i = 0; i < n; i++)
357                 if (c->ltab[i].cmt) {
358                         c->ltab[i].cmt = 0;
359                         *lnum = i + c->lpt_first;
360                         return 0;
361                 }
362         return -ENOSPC;
363 }
364 
365 /**
366  * write_cnodes - write cnodes for commit.
367  * @c: UBIFS file-system description object
368  *
369  * This function returns %0 on success and a negative error code on failure.
370  */
371 static int write_cnodes(struct ubifs_info *c)
372 {
373         int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
374         struct ubifs_cnode *cnode;
375         void *buf = c->lpt_buf;
376 
377         cnode = c->lpt_cnext;
378         if (!cnode)
379                 return 0;
380         lnum = c->nhead_lnum;
381         offs = c->nhead_offs;
382         from = offs;
383         /* Ensure empty LEB is unmapped */
384         if (offs == 0) {
385                 err = ubifs_leb_unmap(c, lnum);
386                 if (err)
387                         return err;
388         }
389         /* Try to place lsave and ltab nicely */
390         done_lsave = !c->big_lpt;
391         done_ltab = 0;
392         if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
393                 done_lsave = 1;
394                 ubifs_pack_lsave(c, buf + offs, c->lsave);
395                 offs += c->lsave_sz;
396                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
397         }
398 
399         if (offs + c->ltab_sz <= c->leb_size) {
400                 done_ltab = 1;
401                 ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
402                 offs += c->ltab_sz;
403                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
404         }
405 
406         /* Loop for each cnode */
407         do {
408                 if (cnode->level)
409                         len = c->nnode_sz;
410                 else
411                         len = c->pnode_sz;
412                 while (offs + len > c->leb_size) {
413                         wlen = offs - from;
414                         if (wlen) {
415                                 alen = ALIGN(wlen, c->min_io_size);
416                                 memset(buf + offs, 0xff, alen - wlen);
417                                 err = ubifs_leb_write(c, lnum, buf + from, from,
418                                                        alen);
419                                 if (err)
420                                         return err;
421                         }
422                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
423                         err = realloc_lpt_leb(c, &lnum);
424                         if (err)
425                                 goto no_space;
426                         offs = 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_atomic();
463                 clear_bit(COW_CNODE, &cnode->flags);
464                 smp_mb__after_atomic();
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                         if (err)
478                                 return err;
479                         dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
480                         err = realloc_lpt_leb(c, &lnum);
481                         if (err)
482                                 goto no_space;
483                         offs = from = 0;
484                         ubifs_assert(lnum >= c->lpt_first &&
485                                      lnum <= c->lpt_last);
486                         err = ubifs_leb_unmap(c, lnum);
487                         if (err)
488                                 return err;
489                 }
490                 done_lsave = 1;
491                 ubifs_pack_lsave(c, buf + offs, c->lsave);
492                 offs += c->lsave_sz;
493                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
494         }
495 
496         /* Make sure to place LPT's own lprops table */
497         if (!done_ltab) {
498                 if (offs + c->ltab_sz > c->leb_size) {
499                         wlen = offs - from;
500                         alen = ALIGN(wlen, c->min_io_size);
501                         memset(buf + offs, 0xff, alen - wlen);
502                         err = ubifs_leb_write(c, lnum, buf + from, from, alen);
503                         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                 ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
517                 offs += c->ltab_sz;
518                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
519         }
520 
521         /* Write remaining data in buffer */
522         wlen = offs - from;
523         alen = ALIGN(wlen, c->min_io_size);
524         memset(buf + offs, 0xff, alen - wlen);
525         err = ubifs_leb_write(c, lnum, buf + from, from, alen);
526         if (err)
527                 return err;
528 
529         dbg_chk_lpt_sz(c, 4, alen - wlen);
530         err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
531         if (err)
532                 return err;
533 
534         c->nhead_lnum = lnum;
535         c->nhead_offs = ALIGN(offs, c->min_io_size);
536 
537         dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
538         dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
539         dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
540         if (c->big_lpt)
541                 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
542 
543         return 0;
544 
545 no_space:
546         ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
547                   lnum, offs, len, done_ltab, done_lsave);
548         ubifs_dump_lpt_info(c);
549         ubifs_dump_lpt_lebs(c);
550         dump_stack();
551         return err;
552 }
553 
554 /**
555  * next_pnode_to_dirty - find next pnode to dirty.
556  * @c: UBIFS file-system description object
557  * @pnode: pnode
558  *
559  * This function returns the next pnode to dirty or %NULL if there are no more
560  * pnodes.  Note that pnodes that have never been written (lnum == 0) are
561  * skipped.
562  */
563 static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
564                                                struct ubifs_pnode *pnode)
565 {
566         struct ubifs_nnode *nnode;
567         int iip;
568 
569         /* Try to go right */
570         nnode = pnode->parent;
571         for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
572                 if (nnode->nbranch[iip].lnum)
573                         return ubifs_get_pnode(c, nnode, iip);
574         }
575 
576         /* Go up while can't go right */
577         do {
578                 iip = nnode->iip + 1;
579                 nnode = nnode->parent;
580                 if (!nnode)
581                         return NULL;
582                 for (; iip < UBIFS_LPT_FANOUT; iip++) {
583                         if (nnode->nbranch[iip].lnum)
584                                 break;
585                 }
586         } while (iip >= UBIFS_LPT_FANOUT);
587 
588         /* Go right */
589         nnode = ubifs_get_nnode(c, nnode, iip);
590         if (IS_ERR(nnode))
591                 return (void *)nnode;
592 
593         /* Go down to level 1 */
594         while (nnode->level > 1) {
595                 for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
596                         if (nnode->nbranch[iip].lnum)
597                                 break;
598                 }
599                 if (iip >= UBIFS_LPT_FANOUT) {
600                         /*
601                          * Should not happen, but we need to keep going
602                          * if it does.
603                          */
604                         iip = 0;
605                 }
606                 nnode = ubifs_get_nnode(c, nnode, iip);
607                 if (IS_ERR(nnode))
608                         return (void *)nnode;
609         }
610 
611         for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
612                 if (nnode->nbranch[iip].lnum)
613                         break;
614         if (iip >= UBIFS_LPT_FANOUT)
615                 /* Should not happen, but we need to keep going if it does */
616                 iip = 0;
617         return ubifs_get_pnode(c, nnode, iip);
618 }
619 
620 /**
621  * pnode_lookup - lookup a pnode in the LPT.
622  * @c: UBIFS file-system description object
623  * @i: pnode number (0 to main_lebs - 1)
624  *
625  * This function returns a pointer to the pnode on success or a negative
626  * error code on failure.
627  */
628 static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
629 {
630         int err, h, iip, shft;
631         struct ubifs_nnode *nnode;
632 
633         if (!c->nroot) {
634                 err = ubifs_read_nnode(c, NULL, 0);
635                 if (err)
636                         return ERR_PTR(err);
637         }
638         i <<= UBIFS_LPT_FANOUT_SHIFT;
639         nnode = c->nroot;
640         shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
641         for (h = 1; h < c->lpt_hght; h++) {
642                 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
643                 shft -= UBIFS_LPT_FANOUT_SHIFT;
644                 nnode = ubifs_get_nnode(c, nnode, iip);
645                 if (IS_ERR(nnode))
646                         return ERR_CAST(nnode);
647         }
648         iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
649         return ubifs_get_pnode(c, nnode, iip);
650 }
651 
652 /**
653  * add_pnode_dirt - add dirty space to LPT LEB properties.
654  * @c: UBIFS file-system description object
655  * @pnode: pnode for which to add dirt
656  */
657 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
658 {
659         ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
660                            c->pnode_sz);
661 }
662 
663 /**
664  * do_make_pnode_dirty - mark a pnode dirty.
665  * @c: UBIFS file-system description object
666  * @pnode: pnode to mark dirty
667  */
668 static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
669 {
670         /* Assumes cnext list is empty i.e. not called during commit */
671         if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
672                 struct ubifs_nnode *nnode;
673 
674                 c->dirty_pn_cnt += 1;
675                 add_pnode_dirt(c, pnode);
676                 /* Mark parent and ancestors dirty too */
677                 nnode = pnode->parent;
678                 while (nnode) {
679                         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
680                                 c->dirty_nn_cnt += 1;
681                                 ubifs_add_nnode_dirt(c, nnode);
682                                 nnode = nnode->parent;
683                         } else
684                                 break;
685                 }
686         }
687 }
688 
689 /**
690  * make_tree_dirty - mark the entire LEB properties tree dirty.
691  * @c: UBIFS file-system description object
692  *
693  * This function is used by the "small" LPT model to cause the entire LEB
694  * properties tree to be written.  The "small" LPT model does not use LPT
695  * garbage collection because it is more efficient to write the entire tree
696  * (because it is small).
697  *
698  * This function returns %0 on success and a negative error code on failure.
699  */
700 static int make_tree_dirty(struct ubifs_info *c)
701 {
702         struct ubifs_pnode *pnode;
703 
704         pnode = pnode_lookup(c, 0);
705         if (IS_ERR(pnode))
706                 return PTR_ERR(pnode);
707 
708         while (pnode) {
709                 do_make_pnode_dirty(c, pnode);
710                 pnode = next_pnode_to_dirty(c, pnode);
711                 if (IS_ERR(pnode))
712                         return PTR_ERR(pnode);
713         }
714         return 0;
715 }
716 
717 /**
718  * need_write_all - determine if the LPT area is running out of free space.
719  * @c: UBIFS file-system description object
720  *
721  * This function returns %1 if the LPT area is running out of free space and %0
722  * if it is not.
723  */
724 static int need_write_all(struct ubifs_info *c)
725 {
726         long long free = 0;
727         int i;
728 
729         for (i = 0; i < c->lpt_lebs; i++) {
730                 if (i + c->lpt_first == c->nhead_lnum)
731                         free += c->leb_size - c->nhead_offs;
732                 else if (c->ltab[i].free == c->leb_size)
733                         free += c->leb_size;
734                 else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
735                         free += c->leb_size;
736         }
737         /* Less than twice the size left */
738         if (free <= c->lpt_sz * 2)
739                 return 1;
740         return 0;
741 }
742 
743 /**
744  * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
745  * @c: UBIFS file-system description object
746  *
747  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
748  * free space and so may be reused as soon as the next commit is completed.
749  * This function is called during start commit to mark LPT LEBs for trivial GC.
750  */
751 static void lpt_tgc_start(struct ubifs_info *c)
752 {
753         int i;
754 
755         for (i = 0; i < c->lpt_lebs; i++) {
756                 if (i + c->lpt_first == c->nhead_lnum)
757                         continue;
758                 if (c->ltab[i].dirty > 0 &&
759                     c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
760                         c->ltab[i].tgc = 1;
761                         c->ltab[i].free = c->leb_size;
762                         c->ltab[i].dirty = 0;
763                         dbg_lp("LEB %d", i + c->lpt_first);
764                 }
765         }
766 }
767 
768 /**
769  * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
770  * @c: UBIFS file-system description object
771  *
772  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
773  * free space and so may be reused as soon as the next commit is completed.
774  * This function is called after the commit is completed (master node has been
775  * written) and un-maps LPT LEBs that were marked for trivial GC.
776  */
777 static int lpt_tgc_end(struct ubifs_info *c)
778 {
779         int i, err;
780 
781         for (i = 0; i < c->lpt_lebs; i++)
782                 if (c->ltab[i].tgc) {
783                         err = ubifs_leb_unmap(c, i + c->lpt_first);
784                         if (err)
785                                 return err;
786                         c->ltab[i].tgc = 0;
787                         dbg_lp("LEB %d", i + c->lpt_first);
788                 }
789         return 0;
790 }
791 
792 /**
793  * populate_lsave - fill the lsave array with important LEB numbers.
794  * @c: the UBIFS file-system description object
795  *
796  * This function is only called for the "big" model. It records a small number
797  * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
798  * most important to least important): empty, freeable, freeable index, dirty
799  * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
800  * their pnodes into memory.  That will stop us from having to scan the LPT
801  * straight away. For the "small" model we assume that scanning the LPT is no
802  * big deal.
803  */
804 static void populate_lsave(struct ubifs_info *c)
805 {
806         struct ubifs_lprops *lprops;
807         struct ubifs_lpt_heap *heap;
808         int i, cnt = 0;
809 
810         ubifs_assert(c->big_lpt);
811         if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
812                 c->lpt_drty_flgs |= LSAVE_DIRTY;
813                 ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
814         }
815 
816         if (dbg_populate_lsave(c))
817                 return;
818 
819         list_for_each_entry(lprops, &c->empty_list, list) {
820                 c->lsave[cnt++] = lprops->lnum;
821                 if (cnt >= c->lsave_cnt)
822                         return;
823         }
824         list_for_each_entry(lprops, &c->freeable_list, list) {
825                 c->lsave[cnt++] = lprops->lnum;
826                 if (cnt >= c->lsave_cnt)
827                         return;
828         }
829         list_for_each_entry(lprops, &c->frdi_idx_list, list) {
830                 c->lsave[cnt++] = lprops->lnum;
831                 if (cnt >= c->lsave_cnt)
832                         return;
833         }
834         heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
835         for (i = 0; i < heap->cnt; i++) {
836                 c->lsave[cnt++] = heap->arr[i]->lnum;
837                 if (cnt >= c->lsave_cnt)
838                         return;
839         }
840         heap = &c->lpt_heap[LPROPS_DIRTY - 1];
841         for (i = 0; i < heap->cnt; i++) {
842                 c->lsave[cnt++] = heap->arr[i]->lnum;
843                 if (cnt >= c->lsave_cnt)
844                         return;
845         }
846         heap = &c->lpt_heap[LPROPS_FREE - 1];
847         for (i = 0; i < heap->cnt; i++) {
848                 c->lsave[cnt++] = heap->arr[i]->lnum;
849                 if (cnt >= c->lsave_cnt)
850                         return;
851         }
852         /* Fill it up completely */
853         while (cnt < c->lsave_cnt)
854                 c->lsave[cnt++] = c->main_first;
855 }
856 
857 /**
858  * nnode_lookup - lookup a nnode in the LPT.
859  * @c: UBIFS file-system description object
860  * @i: nnode number
861  *
862  * This function returns a pointer to the nnode on success or a negative
863  * error code on failure.
864  */
865 static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
866 {
867         int err, iip;
868         struct ubifs_nnode *nnode;
869 
870         if (!c->nroot) {
871                 err = ubifs_read_nnode(c, NULL, 0);
872                 if (err)
873                         return ERR_PTR(err);
874         }
875         nnode = c->nroot;
876         while (1) {
877                 iip = i & (UBIFS_LPT_FANOUT - 1);
878                 i >>= UBIFS_LPT_FANOUT_SHIFT;
879                 if (!i)
880                         break;
881                 nnode = ubifs_get_nnode(c, nnode, iip);
882                 if (IS_ERR(nnode))
883                         return nnode;
884         }
885         return nnode;
886 }
887 
888 /**
889  * make_nnode_dirty - find a nnode and, if found, make it dirty.
890  * @c: UBIFS file-system description object
891  * @node_num: nnode number of nnode to make dirty
892  * @lnum: LEB number where nnode was written
893  * @offs: offset where nnode was written
894  *
895  * This function is used by LPT garbage collection.  LPT garbage collection is
896  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
897  * simply involves marking all the nodes in the LEB being garbage-collected as
898  * dirty.  The dirty nodes are written next commit, after which the LEB is free
899  * to be reused.
900  *
901  * This function returns %0 on success and a negative error code on failure.
902  */
903 static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
904                             int offs)
905 {
906         struct ubifs_nnode *nnode;
907 
908         nnode = nnode_lookup(c, node_num);
909         if (IS_ERR(nnode))
910                 return PTR_ERR(nnode);
911         if (nnode->parent) {
912                 struct ubifs_nbranch *branch;
913 
914                 branch = &nnode->parent->nbranch[nnode->iip];
915                 if (branch->lnum != lnum || branch->offs != offs)
916                         return 0; /* nnode is obsolete */
917         } else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
918                         return 0; /* nnode is obsolete */
919         /* Assumes cnext list is empty i.e. not called during commit */
920         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
921                 c->dirty_nn_cnt += 1;
922                 ubifs_add_nnode_dirt(c, nnode);
923                 /* Mark parent and ancestors dirty too */
924                 nnode = nnode->parent;
925                 while (nnode) {
926                         if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
927                                 c->dirty_nn_cnt += 1;
928                                 ubifs_add_nnode_dirt(c, nnode);
929                                 nnode = nnode->parent;
930                         } else
931                                 break;
932                 }
933         }
934         return 0;
935 }
936 
937 /**
938  * make_pnode_dirty - find a pnode and, if found, make it dirty.
939  * @c: UBIFS file-system description object
940  * @node_num: pnode number of pnode to make dirty
941  * @lnum: LEB number where pnode was written
942  * @offs: offset where pnode was written
943  *
944  * This function is used by LPT garbage collection.  LPT garbage collection is
945  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
946  * simply involves marking all the nodes in the LEB being garbage-collected as
947  * dirty.  The dirty nodes are written next commit, after which the LEB is free
948  * to be reused.
949  *
950  * This function returns %0 on success and a negative error code on failure.
951  */
952 static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
953                             int offs)
954 {
955         struct ubifs_pnode *pnode;
956         struct ubifs_nbranch *branch;
957 
958         pnode = pnode_lookup(c, node_num);
959         if (IS_ERR(pnode))
960                 return PTR_ERR(pnode);
961         branch = &pnode->parent->nbranch[pnode->iip];
962         if (branch->lnum != lnum || branch->offs != offs)
963                 return 0;
964         do_make_pnode_dirty(c, pnode);
965         return 0;
966 }
967 
968 /**
969  * make_ltab_dirty - make ltab node dirty.
970  * @c: UBIFS file-system description object
971  * @lnum: LEB number where ltab was written
972  * @offs: offset where ltab was written
973  *
974  * This function is used by LPT garbage collection.  LPT garbage collection is
975  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
976  * simply involves marking all the nodes in the LEB being garbage-collected as
977  * dirty.  The dirty nodes are written next commit, after which the LEB is free
978  * to be reused.
979  *
980  * This function returns %0 on success and a negative error code on failure.
981  */
982 static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
983 {
984         if (lnum != c->ltab_lnum || offs != c->ltab_offs)
985                 return 0; /* This ltab node is obsolete */
986         if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
987                 c->lpt_drty_flgs |= LTAB_DIRTY;
988                 ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
989         }
990         return 0;
991 }
992 
993 /**
994  * make_lsave_dirty - make lsave node dirty.
995  * @c: UBIFS file-system description object
996  * @lnum: LEB number where lsave was written
997  * @offs: offset where lsave was written
998  *
999  * This function is used by LPT garbage collection.  LPT garbage collection is
1000  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1001  * simply involves marking all the nodes in the LEB being garbage-collected as
1002  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1003  * to be reused.
1004  *
1005  * This function returns %0 on success and a negative error code on failure.
1006  */
1007 static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1008 {
1009         if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1010                 return 0; /* This lsave node is obsolete */
1011         if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
1012                 c->lpt_drty_flgs |= LSAVE_DIRTY;
1013                 ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
1014         }
1015         return 0;
1016 }
1017 
1018 /**
1019  * make_node_dirty - make node dirty.
1020  * @c: UBIFS file-system description object
1021  * @node_type: LPT node type
1022  * @node_num: node number
1023  * @lnum: LEB number where node was written
1024  * @offs: offset where node was written
1025  *
1026  * This function is used by LPT garbage collection.  LPT garbage collection is
1027  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1028  * simply involves marking all the nodes in the LEB being garbage-collected as
1029  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1030  * to be reused.
1031  *
1032  * This function returns %0 on success and a negative error code on failure.
1033  */
1034 static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
1035                            int lnum, int offs)
1036 {
1037         switch (node_type) {
1038         case UBIFS_LPT_NNODE:
1039                 return make_nnode_dirty(c, node_num, lnum, offs);
1040         case UBIFS_LPT_PNODE:
1041                 return make_pnode_dirty(c, node_num, lnum, offs);
1042         case UBIFS_LPT_LTAB:
1043                 return make_ltab_dirty(c, lnum, offs);
1044         case UBIFS_LPT_LSAVE:
1045                 return make_lsave_dirty(c, lnum, offs);
1046         }
1047         return -EINVAL;
1048 }
1049 
1050 /**
1051  * get_lpt_node_len - return the length of a node based on its type.
1052  * @c: UBIFS file-system description object
1053  * @node_type: LPT node type
1054  */
1055 static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
1056 {
1057         switch (node_type) {
1058         case UBIFS_LPT_NNODE:
1059                 return c->nnode_sz;
1060         case UBIFS_LPT_PNODE:
1061                 return c->pnode_sz;
1062         case UBIFS_LPT_LTAB:
1063                 return c->ltab_sz;
1064         case UBIFS_LPT_LSAVE:
1065                 return c->lsave_sz;
1066         }
1067         return 0;
1068 }
1069 
1070 /**
1071  * get_pad_len - return the length of padding in a buffer.
1072  * @c: UBIFS file-system description object
1073  * @buf: buffer
1074  * @len: length of buffer
1075  */
1076 static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
1077 {
1078         int offs, pad_len;
1079 
1080         if (c->min_io_size == 1)
1081                 return 0;
1082         offs = c->leb_size - len;
1083         pad_len = ALIGN(offs, c->min_io_size) - offs;
1084         return pad_len;
1085 }
1086 
1087 /**
1088  * get_lpt_node_type - return type (and node number) of a node in a buffer.
1089  * @c: UBIFS file-system description object
1090  * @buf: buffer
1091  * @node_num: node number is returned here
1092  */
1093 static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
1094                              int *node_num)
1095 {
1096         uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1097         int pos = 0, node_type;
1098 
1099         node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1100         *node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1101         return node_type;
1102 }
1103 
1104 /**
1105  * is_a_node - determine if a buffer contains a node.
1106  * @c: UBIFS file-system description object
1107  * @buf: buffer
1108  * @len: length of buffer
1109  *
1110  * This function returns %1 if the buffer contains a node or %0 if it does not.
1111  */
1112 static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
1113 {
1114         uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1115         int pos = 0, node_type, node_len;
1116         uint16_t crc, calc_crc;
1117 
1118         if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
1119                 return 0;
1120         node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1121         if (node_type == UBIFS_LPT_NOT_A_NODE)
1122                 return 0;
1123         node_len = get_lpt_node_len(c, node_type);
1124         if (!node_len || node_len > len)
1125                 return 0;
1126         pos = 0;
1127         addr = buf;
1128         crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
1129         calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
1130                          node_len - UBIFS_LPT_CRC_BYTES);
1131         if (crc != calc_crc)
1132                 return 0;
1133         return 1;
1134 }
1135 
1136 /**
1137  * lpt_gc_lnum - garbage collect a LPT LEB.
1138  * @c: UBIFS file-system description object
1139  * @lnum: LEB number to garbage collect
1140  *
1141  * LPT garbage collection is used only for the "big" LPT model
1142  * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
1143  * in the LEB being garbage-collected as dirty.  The dirty nodes are written
1144  * next commit, after which the LEB is free to be reused.
1145  *
1146  * This function returns %0 on success and a negative error code on failure.
1147  */
1148 static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
1149 {
1150         int err, len = c->leb_size, node_type, node_num, node_len, offs;
1151         void *buf = c->lpt_buf;
1152 
1153         dbg_lp("LEB %d", lnum);
1154 
1155         err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1156         if (err)
1157                 return err;
1158 
1159         while (1) {
1160                 if (!is_a_node(c, buf, len)) {
1161                         int pad_len;
1162 
1163                         pad_len = get_pad_len(c, buf, len);
1164                         if (pad_len) {
1165                                 buf += pad_len;
1166                                 len -= pad_len;
1167                                 continue;
1168                         }
1169                         return 0;
1170                 }
1171                 node_type = get_lpt_node_type(c, buf, &node_num);
1172                 node_len = get_lpt_node_len(c, node_type);
1173                 offs = c->leb_size - len;
1174                 ubifs_assert(node_len != 0);
1175                 mutex_lock(&c->lp_mutex);
1176                 err = make_node_dirty(c, node_type, node_num, lnum, offs);
1177                 mutex_unlock(&c->lp_mutex);
1178                 if (err)
1179                         return err;
1180                 buf += node_len;
1181                 len -= node_len;
1182         }
1183         return 0;
1184 }
1185 
1186 /**
1187  * lpt_gc - LPT garbage collection.
1188  * @c: UBIFS file-system description object
1189  *
1190  * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
1191  * Returns %0 on success and a negative error code on failure.
1192  */
1193 static int lpt_gc(struct ubifs_info *c)
1194 {
1195         int i, lnum = -1, dirty = 0;
1196 
1197         mutex_lock(&c->lp_mutex);
1198         for (i = 0; i < c->lpt_lebs; i++) {
1199                 ubifs_assert(!c->ltab[i].tgc);
1200                 if (i + c->lpt_first == c->nhead_lnum ||
1201                     c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
1202                         continue;
1203                 if (c->ltab[i].dirty > dirty) {
1204                         dirty = c->ltab[i].dirty;
1205                         lnum = i + c->lpt_first;
1206                 }
1207         }
1208         mutex_unlock(&c->lp_mutex);
1209         if (lnum == -1)
1210                 return -ENOSPC;
1211         return lpt_gc_lnum(c, lnum);
1212 }
1213 
1214 /**
1215  * ubifs_lpt_start_commit - UBIFS commit starts.
1216  * @c: the UBIFS file-system description object
1217  *
1218  * This function has to be called when UBIFS starts the commit operation.
1219  * This function "freezes" all currently dirty LEB properties and does not
1220  * change them anymore. Further changes are saved and tracked separately
1221  * because they are not part of this commit. This function returns zero in case
1222  * of success and a negative error code in case of failure.
1223  */
1224 int ubifs_lpt_start_commit(struct ubifs_info *c)
1225 {
1226         int err, cnt;
1227 
1228         dbg_lp("");
1229 
1230         mutex_lock(&c->lp_mutex);
1231         err = dbg_chk_lpt_free_spc(c);
1232         if (err)
1233                 goto out;
1234         err = dbg_check_ltab(c);
1235         if (err)
1236                 goto out;
1237 
1238         if (c->check_lpt_free) {
1239                 /*
1240                  * We ensure there is enough free space in
1241                  * ubifs_lpt_post_commit() by marking nodes dirty. That
1242                  * information is lost when we unmount, so we also need
1243                  * to check free space once after mounting also.
1244                  */
1245                 c->check_lpt_free = 0;
1246                 while (need_write_all(c)) {
1247                         mutex_unlock(&c->lp_mutex);
1248                         err = lpt_gc(c);
1249                         if (err)
1250                                 return err;
1251                         mutex_lock(&c->lp_mutex);
1252                 }
1253         }
1254 
1255         lpt_tgc_start(c);
1256 
1257         if (!c->dirty_pn_cnt) {
1258                 dbg_cmt("no cnodes to commit");
1259                 err = 0;
1260                 goto out;
1261         }
1262 
1263         if (!c->big_lpt && need_write_all(c)) {
1264                 /* If needed, write everything */
1265                 err = make_tree_dirty(c);
1266                 if (err)
1267                         goto out;
1268                 lpt_tgc_start(c);
1269         }
1270 
1271         if (c->big_lpt)
1272                 populate_lsave(c);
1273 
1274         cnt = get_cnodes_to_commit(c);
1275         ubifs_assert(cnt != 0);
1276 
1277         err = layout_cnodes(c);
1278         if (err)
1279                 goto out;
1280 
1281         /* Copy the LPT's own lprops for end commit to write */
1282         memcpy(c->ltab_cmt, c->ltab,
1283                sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1284         c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
1285 
1286 out:
1287         mutex_unlock(&c->lp_mutex);
1288         return err;
1289 }
1290 
1291 /**
1292  * free_obsolete_cnodes - free obsolete cnodes for commit end.
1293  * @c: UBIFS file-system description object
1294  */
1295 static void free_obsolete_cnodes(struct ubifs_info *c)
1296 {
1297         struct ubifs_cnode *cnode, *cnext;
1298 
1299         cnext = c->lpt_cnext;
1300         if (!cnext)
1301                 return;
1302         do {
1303                 cnode = cnext;
1304                 cnext = cnode->cnext;
1305                 if (test_bit(OBSOLETE_CNODE, &cnode->flags))
1306                         kfree(cnode);
1307                 else
1308                         cnode->cnext = NULL;
1309         } while (cnext != c->lpt_cnext);
1310         c->lpt_cnext = NULL;
1311 }
1312 
1313 /**
1314  * ubifs_lpt_end_commit - finish the commit operation.
1315  * @c: the UBIFS file-system description object
1316  *
1317  * This function has to be called when the commit operation finishes. It
1318  * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1319  * the media. Returns zero in case of success and a negative error code in case
1320  * of failure.
1321  */
1322 int ubifs_lpt_end_commit(struct ubifs_info *c)
1323 {
1324         int err;
1325 
1326         dbg_lp("");
1327 
1328         if (!c->lpt_cnext)
1329                 return 0;
1330 
1331         err = write_cnodes(c);
1332         if (err)
1333                 return err;
1334 
1335         mutex_lock(&c->lp_mutex);
1336         free_obsolete_cnodes(c);
1337         mutex_unlock(&c->lp_mutex);
1338 
1339         return 0;
1340 }
1341 
1342 /**
1343  * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1344  * @c: UBIFS file-system description object
1345  *
1346  * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1347  * commit for the "big" LPT model.
1348  */
1349 int ubifs_lpt_post_commit(struct ubifs_info *c)
1350 {
1351         int err;
1352 
1353         mutex_lock(&c->lp_mutex);
1354         err = lpt_tgc_end(c);
1355         if (err)
1356                 goto out;
1357         if (c->big_lpt)
1358                 while (need_write_all(c)) {
1359                         mutex_unlock(&c->lp_mutex);
1360                         err = lpt_gc(c);
1361                         if (err)
1362                                 return err;
1363                         mutex_lock(&c->lp_mutex);
1364                 }
1365 out:
1366         mutex_unlock(&c->lp_mutex);
1367         return err;
1368 }
1369 
1370 /**
1371  * first_nnode - find the first nnode in memory.
1372  * @c: UBIFS file-system description object
1373  * @hght: height of tree where nnode found is returned here
1374  *
1375  * This function returns a pointer to the nnode found or %NULL if no nnode is
1376  * found. This function is a helper to 'ubifs_lpt_free()'.
1377  */
1378 static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1379 {
1380         struct ubifs_nnode *nnode;
1381         int h, i, found;
1382 
1383         nnode = c->nroot;
1384         *hght = 0;
1385         if (!nnode)
1386                 return NULL;
1387         for (h = 1; h < c->lpt_hght; h++) {
1388                 found = 0;
1389                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1390                         if (nnode->nbranch[i].nnode) {
1391                                 found = 1;
1392                                 nnode = nnode->nbranch[i].nnode;
1393                                 *hght = h;
1394                                 break;
1395                         }
1396                 }
1397                 if (!found)
1398                         break;
1399         }
1400         return nnode;
1401 }
1402 
1403 /**
1404  * next_nnode - find the next nnode in memory.
1405  * @c: UBIFS file-system description object
1406  * @nnode: nnode from which to start.
1407  * @hght: height of tree where nnode is, is passed and returned here
1408  *
1409  * This function returns a pointer to the nnode found or %NULL if no nnode is
1410  * found. This function is a helper to 'ubifs_lpt_free()'.
1411  */
1412 static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1413                                       struct ubifs_nnode *nnode, int *hght)
1414 {
1415         struct ubifs_nnode *parent;
1416         int iip, h, i, found;
1417 
1418         parent = nnode->parent;
1419         if (!parent)
1420                 return NULL;
1421         if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1422                 *hght -= 1;
1423                 return parent;
1424         }
1425         for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1426                 nnode = parent->nbranch[iip].nnode;
1427                 if (nnode)
1428                         break;
1429         }
1430         if (!nnode) {
1431                 *hght -= 1;
1432                 return parent;
1433         }
1434         for (h = *hght + 1; h < c->lpt_hght; h++) {
1435                 found = 0;
1436                 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1437                         if (nnode->nbranch[i].nnode) {
1438                                 found = 1;
1439                                 nnode = nnode->nbranch[i].nnode;
1440                                 *hght = h;
1441                                 break;
1442                         }
1443                 }
1444                 if (!found)
1445                         break;
1446         }
1447         return nnode;
1448 }
1449 
1450 /**
1451  * ubifs_lpt_free - free resources owned by the LPT.
1452  * @c: UBIFS file-system description object
1453  * @wr_only: free only resources used for writing
1454  */
1455 void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1456 {
1457         struct ubifs_nnode *nnode;
1458         int i, hght;
1459 
1460         /* Free write-only things first */
1461 
1462         free_obsolete_cnodes(c); /* Leftover from a failed commit */
1463 
1464         vfree(c->ltab_cmt);
1465         c->ltab_cmt = NULL;
1466         vfree(c->lpt_buf);
1467         c->lpt_buf = NULL;
1468         kfree(c->lsave);
1469         c->lsave = NULL;
1470 
1471         if (wr_only)
1472                 return;
1473 
1474         /* Now free the rest */
1475 
1476         nnode = first_nnode(c, &hght);
1477         while (nnode) {
1478                 for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1479                         kfree(nnode->nbranch[i].nnode);
1480                 nnode = next_nnode(c, nnode, &hght);
1481         }
1482         for (i = 0; i < LPROPS_HEAP_CNT; i++)
1483                 kfree(c->lpt_heap[i].arr);
1484         kfree(c->dirty_idx.arr);
1485         kfree(c->nroot);
1486         vfree(c->ltab);
1487         kfree(c->lpt_nod_buf);
1488 }
1489 
1490 /*
1491  * Everything below is related to debugging.
1492  */
1493 
1494 /**
1495  * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1496  * @buf: buffer
1497  * @len: buffer length
1498  */
1499 static int dbg_is_all_ff(uint8_t *buf, int len)
1500 {
1501         int i;
1502 
1503         for (i = 0; i < len; i++)
1504                 if (buf[i] != 0xff)
1505                         return 0;
1506         return 1;
1507 }
1508 
1509 /**
1510  * dbg_is_nnode_dirty - determine if a nnode is dirty.
1511  * @c: the UBIFS file-system description object
1512  * @lnum: LEB number where nnode was written
1513  * @offs: offset where nnode was written
1514  */
1515 static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1516 {
1517         struct ubifs_nnode *nnode;
1518         int hght;
1519 
1520         /* Entire tree is in memory so first_nnode / next_nnode are OK */
1521         nnode = first_nnode(c, &hght);
1522         for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1523                 struct ubifs_nbranch *branch;
1524 
1525                 cond_resched();
1526                 if (nnode->parent) {
1527                         branch = &nnode->parent->nbranch[nnode->iip];
1528                         if (branch->lnum != lnum || branch->offs != offs)
1529                                 continue;
1530                         if (test_bit(DIRTY_CNODE, &nnode->flags))
1531                                 return 1;
1532                         return 0;
1533                 } else {
1534                         if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1535                                 continue;
1536                         if (test_bit(DIRTY_CNODE, &nnode->flags))
1537                                 return 1;
1538                         return 0;
1539                 }
1540         }
1541         return 1;
1542 }
1543 
1544 /**
1545  * dbg_is_pnode_dirty - determine if a pnode is dirty.
1546  * @c: the UBIFS file-system description object
1547  * @lnum: LEB number where pnode was written
1548  * @offs: offset where pnode was written
1549  */
1550 static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1551 {
1552         int i, cnt;
1553 
1554         cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1555         for (i = 0; i < cnt; i++) {
1556                 struct ubifs_pnode *pnode;
1557                 struct ubifs_nbranch *branch;
1558 
1559                 cond_resched();
1560                 pnode = pnode_lookup(c, i);
1561                 if (IS_ERR(pnode))
1562                         return PTR_ERR(pnode);
1563                 branch = &pnode->parent->nbranch[pnode->iip];
1564                 if (branch->lnum != lnum || branch->offs != offs)
1565                         continue;
1566                 if (test_bit(DIRTY_CNODE, &pnode->flags))
1567                         return 1;
1568                 return 0;
1569         }
1570         return 1;
1571 }
1572 
1573 /**
1574  * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1575  * @c: the UBIFS file-system description object
1576  * @lnum: LEB number where ltab node was written
1577  * @offs: offset where ltab node was written
1578  */
1579 static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1580 {
1581         if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1582                 return 1;
1583         return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1584 }
1585 
1586 /**
1587  * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1588  * @c: the UBIFS file-system description object
1589  * @lnum: LEB number where lsave node was written
1590  * @offs: offset where lsave node was written
1591  */
1592 static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1593 {
1594         if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1595                 return 1;
1596         return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1597 }
1598 
1599 /**
1600  * dbg_is_node_dirty - determine if a node is dirty.
1601  * @c: the UBIFS file-system description object
1602  * @node_type: node type
1603  * @lnum: LEB number where node was written
1604  * @offs: offset where node was written
1605  */
1606 static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1607                              int offs)
1608 {
1609         switch (node_type) {
1610         case UBIFS_LPT_NNODE:
1611                 return dbg_is_nnode_dirty(c, lnum, offs);
1612         case UBIFS_LPT_PNODE:
1613                 return dbg_is_pnode_dirty(c, lnum, offs);
1614         case UBIFS_LPT_LTAB:
1615                 return dbg_is_ltab_dirty(c, lnum, offs);
1616         case UBIFS_LPT_LSAVE:
1617                 return dbg_is_lsave_dirty(c, lnum, offs);
1618         }
1619         return 1;
1620 }
1621 
1622 /**
1623  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1624  * @c: the UBIFS file-system description object
1625  * @lnum: LEB number where node was written
1626  * @offs: offset where node was written
1627  *
1628  * This function returns %0 on success and a negative error code on failure.
1629  */
1630 static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1631 {
1632         int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1633         int ret;
1634         void *buf, *p;
1635 
1636         if (!dbg_is_chk_lprops(c))
1637                 return 0;
1638 
1639         buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1640         if (!buf) {
1641                 ubifs_err(c, "cannot allocate memory for ltab checking");
1642                 return 0;
1643         }
1644 
1645         dbg_lp("LEB %d", lnum);
1646 
1647         err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1648         if (err)
1649                 goto out;
1650 
1651         while (1) {
1652                 if (!is_a_node(c, p, len)) {
1653                         int i, pad_len;
1654 
1655                         pad_len = get_pad_len(c, p, len);
1656                         if (pad_len) {
1657                                 p += pad_len;
1658                                 len -= pad_len;
1659                                 dirty += pad_len;
1660                                 continue;
1661                         }
1662                         if (!dbg_is_all_ff(p, len)) {
1663                                 ubifs_err(c, "invalid empty space in LEB %d at %d",
1664                                           lnum, c->leb_size - len);
1665                                 err = -EINVAL;
1666                         }
1667                         i = lnum - c->lpt_first;
1668                         if (len != c->ltab[i].free) {
1669                                 ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)",
1670                                           lnum, len, c->ltab[i].free);
1671                                 err = -EINVAL;
1672                         }
1673                         if (dirty != c->ltab[i].dirty) {
1674                                 ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)",
1675                                           lnum, dirty, c->ltab[i].dirty);
1676                                 err = -EINVAL;
1677                         }
1678                         goto out;
1679                 }
1680                 node_type = get_lpt_node_type(c, p, &node_num);
1681                 node_len = get_lpt_node_len(c, node_type);
1682                 ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1683                 if (ret == 1)
1684                         dirty += node_len;
1685                 p += node_len;
1686                 len -= node_len;
1687         }
1688 
1689         err = 0;
1690 out:
1691         vfree(buf);
1692         return err;
1693 }
1694 
1695 /**
1696  * dbg_check_ltab - check the free and dirty space in the ltab.
1697  * @c: the UBIFS file-system description object
1698  *
1699  * This function returns %0 on success and a negative error code on failure.
1700  */
1701 int dbg_check_ltab(struct ubifs_info *c)
1702 {
1703         int lnum, err, i, cnt;
1704 
1705         if (!dbg_is_chk_lprops(c))
1706                 return 0;
1707 
1708         /* Bring the entire tree into memory */
1709         cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1710         for (i = 0; i < cnt; i++) {
1711                 struct ubifs_pnode *pnode;
1712 
1713                 pnode = pnode_lookup(c, i);
1714                 if (IS_ERR(pnode))
1715                         return PTR_ERR(pnode);
1716                 cond_resched();
1717         }
1718 
1719         /* Check nodes */
1720         err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1721         if (err)
1722                 return err;
1723 
1724         /* Check each LEB */
1725         for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1726                 err = dbg_check_ltab_lnum(c, lnum);
1727                 if (err) {
1728                         ubifs_err(c, "failed at LEB %d", lnum);
1729                         return err;
1730                 }
1731         }
1732 
1733         dbg_lp("succeeded");
1734         return 0;
1735 }
1736 
1737 /**
1738  * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1739  * @c: the UBIFS file-system description object
1740  *
1741  * This function returns %0 on success and a negative error code on failure.
1742  */
1743 int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1744 {
1745         long long free = 0;
1746         int i;
1747 
1748         if (!dbg_is_chk_lprops(c))
1749                 return 0;
1750 
1751         for (i = 0; i < c->lpt_lebs; i++) {
1752                 if (c->ltab[i].tgc || c->ltab[i].cmt)
1753                         continue;
1754                 if (i + c->lpt_first == c->nhead_lnum)
1755                         free += c->leb_size - c->nhead_offs;
1756                 else if (c->ltab[i].free == c->leb_size)
1757                         free += c->leb_size;
1758         }
1759         if (free < c->lpt_sz) {
1760                 ubifs_err(c, "LPT space error: free %lld lpt_sz %lld",
1761                           free, c->lpt_sz);
1762                 ubifs_dump_lpt_info(c);
1763                 ubifs_dump_lpt_lebs(c);
1764                 dump_stack();
1765                 return -EINVAL;
1766         }
1767         return 0;
1768 }
1769 
1770 /**
1771  * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1772  * @c: the UBIFS file-system description object
1773  * @action: what to do
1774  * @len: length written
1775  *
1776  * This function returns %0 on success and a negative error code on failure.
1777  * The @action argument may be one of:
1778  *   o %0 - LPT debugging checking starts, initialize debugging variables;
1779  *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1780  *   o %2 - switched to a different LEB and wasted @len bytes;
1781  *   o %3 - check that we've written the right number of bytes.
1782  *   o %4 - wasted @len bytes;
1783  */
1784 int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1785 {
1786         struct ubifs_debug_info *d = c->dbg;
1787         long long chk_lpt_sz, lpt_sz;
1788         int err = 0;
1789 
1790         if (!dbg_is_chk_lprops(c))
1791                 return 0;
1792 
1793         switch (action) {
1794         case 0:
1795                 d->chk_lpt_sz = 0;
1796                 d->chk_lpt_sz2 = 0;
1797                 d->chk_lpt_lebs = 0;
1798                 d->chk_lpt_wastage = 0;
1799                 if (c->dirty_pn_cnt > c->pnode_cnt) {
1800                         ubifs_err(c, "dirty pnodes %d exceed max %d",
1801                                   c->dirty_pn_cnt, c->pnode_cnt);
1802                         err = -EINVAL;
1803                 }
1804                 if (c->dirty_nn_cnt > c->nnode_cnt) {
1805                         ubifs_err(c, "dirty nnodes %d exceed max %d",
1806                                   c->dirty_nn_cnt, c->nnode_cnt);
1807                         err = -EINVAL;
1808                 }
1809                 return err;
1810         case 1:
1811                 d->chk_lpt_sz += len;
1812                 return 0;
1813         case 2:
1814                 d->chk_lpt_sz += len;
1815                 d->chk_lpt_wastage += len;
1816                 d->chk_lpt_lebs += 1;
1817                 return 0;
1818         case 3:
1819                 chk_lpt_sz = c->leb_size;
1820                 chk_lpt_sz *= d->chk_lpt_lebs;
1821                 chk_lpt_sz += len - c->nhead_offs;
1822                 if (d->chk_lpt_sz != chk_lpt_sz) {
1823                         ubifs_err(c, "LPT wrote %lld but space used was %lld",
1824                                   d->chk_lpt_sz, chk_lpt_sz);
1825                         err = -EINVAL;
1826                 }
1827                 if (d->chk_lpt_sz > c->lpt_sz) {
1828                         ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld",
1829                                   d->chk_lpt_sz, c->lpt_sz);
1830                         err = -EINVAL;
1831                 }
1832                 if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1833                         ubifs_err(c, "LPT layout size %lld but wrote %lld",
1834                                   d->chk_lpt_sz, d->chk_lpt_sz2);
1835                         err = -EINVAL;
1836                 }
1837                 if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1838                         ubifs_err(c, "LPT new nhead offs: expected %d was %d",
1839                                   d->new_nhead_offs, len);
1840                         err = -EINVAL;
1841                 }
1842                 lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1843                 lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1844                 lpt_sz += c->ltab_sz;
1845                 if (c->big_lpt)
1846                         lpt_sz += c->lsave_sz;
1847                 if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1848                         ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1849                                   d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1850                         err = -EINVAL;
1851                 }
1852                 if (err) {
1853                         ubifs_dump_lpt_info(c);
1854                         ubifs_dump_lpt_lebs(c);
1855                         dump_stack();
1856                 }
1857                 d->chk_lpt_sz2 = d->chk_lpt_sz;
1858                 d->chk_lpt_sz = 0;
1859                 d->chk_lpt_wastage = 0;
1860                 d->chk_lpt_lebs = 0;
1861                 d->new_nhead_offs = len;
1862                 return err;
1863         case 4:
1864                 d->chk_lpt_sz += len;
1865                 d->chk_lpt_wastage += len;
1866                 return 0;
1867         default:
1868                 return -EINVAL;
1869         }
1870 }
1871 
1872 /**
1873  * ubifs_dump_lpt_leb - dump an LPT LEB.
1874  * @c: UBIFS file-system description object
1875  * @lnum: LEB number to dump
1876  *
1877  * This function dumps an LEB from LPT area. Nodes in this area are very
1878  * different to nodes in the main area (e.g., they do not have common headers,
1879  * they do not have 8-byte alignments, etc), so we have a separate function to
1880  * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1881  */
1882 static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1883 {
1884         int err, len = c->leb_size, node_type, node_num, node_len, offs;
1885         void *buf, *p;
1886 
1887         pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
1888         buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1889         if (!buf) {
1890                 ubifs_err(c, "cannot allocate memory to dump LPT");
1891                 return;
1892         }
1893 
1894         err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1895         if (err)
1896                 goto out;
1897 
1898         while (1) {
1899                 offs = c->leb_size - len;
1900                 if (!is_a_node(c, p, len)) {
1901                         int pad_len;
1902 
1903                         pad_len = get_pad_len(c, p, len);
1904                         if (pad_len) {
1905                                 pr_err("LEB %d:%d, pad %d bytes\n",
1906                                        lnum, offs, pad_len);
1907                                 p += pad_len;
1908                                 len -= pad_len;
1909                                 continue;
1910                         }
1911                         if (len)
1912                                 pr_err("LEB %d:%d, free %d bytes\n",
1913                                        lnum, offs, len);
1914                         break;
1915                 }
1916 
1917                 node_type = get_lpt_node_type(c, p, &node_num);
1918                 switch (node_type) {
1919                 case UBIFS_LPT_PNODE:
1920                 {
1921                         node_len = c->pnode_sz;
1922                         if (c->big_lpt)
1923                                 pr_err("LEB %d:%d, pnode num %d\n",
1924                                        lnum, offs, node_num);
1925                         else
1926                                 pr_err("LEB %d:%d, pnode\n", lnum, offs);
1927                         break;
1928                 }
1929                 case UBIFS_LPT_NNODE:
1930                 {
1931                         int i;
1932                         struct ubifs_nnode nnode;
1933 
1934                         node_len = c->nnode_sz;
1935                         if (c->big_lpt)
1936                                 pr_err("LEB %d:%d, nnode num %d, ",
1937                                        lnum, offs, node_num);
1938                         else
1939                                 pr_err("LEB %d:%d, nnode, ",
1940                                        lnum, offs);
1941                         err = ubifs_unpack_nnode(c, p, &nnode);
1942                         if (err) {
1943                                 pr_err("failed to unpack_node, error %d\n",
1944                                        err);
1945                                 break;
1946                         }
1947                         for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1948                                 pr_cont("%d:%d", nnode.nbranch[i].lnum,
1949                                        nnode.nbranch[i].offs);
1950                                 if (i != UBIFS_LPT_FANOUT - 1)
1951                                         pr_cont(", ");
1952                         }
1953                         pr_cont("\n");
1954                         break;
1955                 }
1956                 case UBIFS_LPT_LTAB:
1957                         node_len = c->ltab_sz;
1958                         pr_err("LEB %d:%d, ltab\n", lnum, offs);
1959                         break;
1960                 case UBIFS_LPT_LSAVE:
1961                         node_len = c->lsave_sz;
1962                         pr_err("LEB %d:%d, lsave len\n", lnum, offs);
1963                         break;
1964                 default:
1965                         ubifs_err(c, "LPT node type %d not recognized", node_type);
1966                         goto out;
1967                 }
1968 
1969                 p += node_len;
1970                 len -= node_len;
1971         }
1972 
1973         pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
1974 out:
1975         vfree(buf);
1976         return;
1977 }
1978 
1979 /**
1980  * ubifs_dump_lpt_lebs - dump LPT lebs.
1981  * @c: UBIFS file-system description object
1982  *
1983  * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1984  * locked.
1985  */
1986 void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
1987 {
1988         int i;
1989 
1990         pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid);
1991         for (i = 0; i < c->lpt_lebs; i++)
1992                 dump_lpt_leb(c, i + c->lpt_first);
1993         pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid);
1994 }
1995 
1996 /**
1997  * dbg_populate_lsave - debugging version of 'populate_lsave()'
1998  * @c: UBIFS file-system description object
1999  *
2000  * This is a debugging version for 'populate_lsave()' which populates lsave
2001  * with random LEBs instead of useful LEBs, which is good for test coverage.
2002  * Returns zero if lsave has not been populated (this debugging feature is
2003  * disabled) an non-zero if lsave has been populated.
2004  */
2005 static int dbg_populate_lsave(struct ubifs_info *c)
2006 {
2007         struct ubifs_lprops *lprops;
2008         struct ubifs_lpt_heap *heap;
2009         int i;
2010 
2011         if (!dbg_is_chk_gen(c))
2012                 return 0;
2013         if (prandom_u32() & 3)
2014                 return 0;
2015 
2016         for (i = 0; i < c->lsave_cnt; i++)
2017                 c->lsave[i] = c->main_first;
2018 
2019         list_for_each_entry(lprops, &c->empty_list, list)
2020                 c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2021         list_for_each_entry(lprops, &c->freeable_list, list)
2022                 c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2023         list_for_each_entry(lprops, &c->frdi_idx_list, list)
2024                 c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2025 
2026         heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
2027         for (i = 0; i < heap->cnt; i++)
2028                 c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2029         heap = &c->lpt_heap[LPROPS_DIRTY - 1];
2030         for (i = 0; i < heap->cnt; i++)
2031                 c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2032         heap = &c->lpt_heap[LPROPS_FREE - 1];
2033         for (i = 0; i < heap->cnt; i++)
2034                 c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2035 
2036         return 1;
2037 }
2038 

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