xref: /openbmc/u-boot/fs/ubifs/lpt_commit.c (revision 0a61ee88)
1 /*
2  * This file is part of UBIFS.
3  *
4  * Copyright (C) 2006-2008 Nokia Corporation.
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  *
8  * Authors: Adrian Hunter
9  *          Artem Bityutskiy (Битюцкий Артём)
10  */
11 
12 /*
13  * This file implements commit-related functionality of the LEB properties
14  * subsystem.
15  */
16 
17 #ifndef __UBOOT__
18 #include <linux/crc16.h>
19 #include <linux/slab.h>
20 #include <linux/random.h>
21 #else
22 #include <linux/compat.h>
23 #include <linux/err.h>
24 #include "crc16.h"
25 #endif
26 #include "ubifs.h"
27 
28 #ifndef __UBOOT__
29 static int dbg_populate_lsave(struct ubifs_info *c);
30 #endif
31 
32 /**
33  * first_dirty_cnode - find first dirty cnode.
34  * @c: UBIFS file-system description object
35  * @nnode: nnode at which to start
36  *
37  * This function returns the first dirty cnode or %NULL if there is not one.
38  */
39 static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
40 {
41 	ubifs_assert(nnode);
42 	while (1) {
43 		int i, cont = 0;
44 
45 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
46 			struct ubifs_cnode *cnode;
47 
48 			cnode = nnode->nbranch[i].cnode;
49 			if (cnode &&
50 			    test_bit(DIRTY_CNODE, &cnode->flags)) {
51 				if (cnode->level == 0)
52 					return cnode;
53 				nnode = (struct ubifs_nnode *)cnode;
54 				cont = 1;
55 				break;
56 			}
57 		}
58 		if (!cont)
59 			return (struct ubifs_cnode *)nnode;
60 	}
61 }
62 
63 /**
64  * next_dirty_cnode - find next dirty cnode.
65  * @cnode: cnode from which to begin searching
66  *
67  * This function returns the next dirty cnode or %NULL if there is not one.
68  */
69 static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
70 {
71 	struct ubifs_nnode *nnode;
72 	int i;
73 
74 	ubifs_assert(cnode);
75 	nnode = cnode->parent;
76 	if (!nnode)
77 		return NULL;
78 	for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
79 		cnode = nnode->nbranch[i].cnode;
80 		if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
81 			if (cnode->level == 0)
82 				return cnode; /* cnode is a pnode */
83 			/* cnode is a nnode */
84 			return first_dirty_cnode((struct ubifs_nnode *)cnode);
85 		}
86 	}
87 	return (struct ubifs_cnode *)nnode;
88 }
89 
90 /**
91  * get_cnodes_to_commit - create list of dirty cnodes to commit.
92  * @c: UBIFS file-system description object
93  *
94  * This function returns the number of cnodes to commit.
95  */
96 static int get_cnodes_to_commit(struct ubifs_info *c)
97 {
98 	struct ubifs_cnode *cnode, *cnext;
99 	int cnt = 0;
100 
101 	if (!c->nroot)
102 		return 0;
103 
104 	if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
105 		return 0;
106 
107 	c->lpt_cnext = first_dirty_cnode(c->nroot);
108 	cnode = c->lpt_cnext;
109 	if (!cnode)
110 		return 0;
111 	cnt += 1;
112 	while (1) {
113 		ubifs_assert(!test_bit(COW_CNODE, &cnode->flags));
114 		__set_bit(COW_CNODE, &cnode->flags);
115 		cnext = next_dirty_cnode(cnode);
116 		if (!cnext) {
117 			cnode->cnext = c->lpt_cnext;
118 			break;
119 		}
120 		cnode->cnext = cnext;
121 		cnode = cnext;
122 		cnt += 1;
123 	}
124 	dbg_cmt("committing %d cnodes", cnt);
125 	dbg_lp("committing %d cnodes", cnt);
126 	ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
127 	return cnt;
128 }
129 
130 /**
131  * upd_ltab - update LPT LEB properties.
132  * @c: UBIFS file-system description object
133  * @lnum: LEB number
134  * @free: amount of free space
135  * @dirty: amount of dirty space to add
136  */
137 static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
138 {
139 	dbg_lp("LEB %d free %d dirty %d to %d +%d",
140 	       lnum, c->ltab[lnum - c->lpt_first].free,
141 	       c->ltab[lnum - c->lpt_first].dirty, free, dirty);
142 	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
143 	c->ltab[lnum - c->lpt_first].free = free;
144 	c->ltab[lnum - c->lpt_first].dirty += dirty;
145 }
146 
147 /**
148  * alloc_lpt_leb - allocate an LPT LEB that is empty.
149  * @c: UBIFS file-system description object
150  * @lnum: LEB number is passed and returned here
151  *
152  * This function finds the next empty LEB in the ltab starting from @lnum. If a
153  * an empty LEB is found it is returned in @lnum and the function returns %0.
154  * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
155  * never to run out of space.
156  */
157 static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
158 {
159 	int i, n;
160 
161 	n = *lnum - c->lpt_first + 1;
162 	for (i = n; i < c->lpt_lebs; i++) {
163 		if (c->ltab[i].tgc || c->ltab[i].cmt)
164 			continue;
165 		if (c->ltab[i].free == c->leb_size) {
166 			c->ltab[i].cmt = 1;
167 			*lnum = i + c->lpt_first;
168 			return 0;
169 		}
170 	}
171 
172 	for (i = 0; i < n; i++) {
173 		if (c->ltab[i].tgc || c->ltab[i].cmt)
174 			continue;
175 		if (c->ltab[i].free == c->leb_size) {
176 			c->ltab[i].cmt = 1;
177 			*lnum = i + c->lpt_first;
178 			return 0;
179 		}
180 	}
181 	return -ENOSPC;
182 }
183 
184 /**
185  * layout_cnodes - layout cnodes for commit.
186  * @c: UBIFS file-system description object
187  *
188  * This function returns %0 on success and a negative error code on failure.
189  */
190 static int layout_cnodes(struct ubifs_info *c)
191 {
192 	int lnum, offs, len, alen, done_lsave, done_ltab, err;
193 	struct ubifs_cnode *cnode;
194 
195 	err = dbg_chk_lpt_sz(c, 0, 0);
196 	if (err)
197 		return err;
198 	cnode = c->lpt_cnext;
199 	if (!cnode)
200 		return 0;
201 	lnum = c->nhead_lnum;
202 	offs = c->nhead_offs;
203 	/* Try to place lsave and ltab nicely */
204 	done_lsave = !c->big_lpt;
205 	done_ltab = 0;
206 	if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
207 		done_lsave = 1;
208 		c->lsave_lnum = lnum;
209 		c->lsave_offs = offs;
210 		offs += c->lsave_sz;
211 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
212 	}
213 
214 	if (offs + c->ltab_sz <= c->leb_size) {
215 		done_ltab = 1;
216 		c->ltab_lnum = lnum;
217 		c->ltab_offs = offs;
218 		offs += c->ltab_sz;
219 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
220 	}
221 
222 	do {
223 		if (cnode->level) {
224 			len = c->nnode_sz;
225 			c->dirty_nn_cnt -= 1;
226 		} else {
227 			len = c->pnode_sz;
228 			c->dirty_pn_cnt -= 1;
229 		}
230 		while (offs + len > c->leb_size) {
231 			alen = ALIGN(offs, c->min_io_size);
232 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
233 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
234 			err = alloc_lpt_leb(c, &lnum);
235 			if (err)
236 				goto no_space;
237 			offs = 0;
238 			ubifs_assert(lnum >= c->lpt_first &&
239 				     lnum <= c->lpt_last);
240 			/* Try to place lsave and ltab nicely */
241 			if (!done_lsave) {
242 				done_lsave = 1;
243 				c->lsave_lnum = lnum;
244 				c->lsave_offs = offs;
245 				offs += c->lsave_sz;
246 				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
247 				continue;
248 			}
249 			if (!done_ltab) {
250 				done_ltab = 1;
251 				c->ltab_lnum = lnum;
252 				c->ltab_offs = offs;
253 				offs += c->ltab_sz;
254 				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
255 				continue;
256 			}
257 			break;
258 		}
259 		if (cnode->parent) {
260 			cnode->parent->nbranch[cnode->iip].lnum = lnum;
261 			cnode->parent->nbranch[cnode->iip].offs = offs;
262 		} else {
263 			c->lpt_lnum = lnum;
264 			c->lpt_offs = offs;
265 		}
266 		offs += len;
267 		dbg_chk_lpt_sz(c, 1, len);
268 		cnode = cnode->cnext;
269 	} while (cnode && cnode != c->lpt_cnext);
270 
271 	/* Make sure to place LPT's save table */
272 	if (!done_lsave) {
273 		if (offs + c->lsave_sz > c->leb_size) {
274 			alen = ALIGN(offs, c->min_io_size);
275 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
276 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
277 			err = alloc_lpt_leb(c, &lnum);
278 			if (err)
279 				goto no_space;
280 			offs = 0;
281 			ubifs_assert(lnum >= c->lpt_first &&
282 				     lnum <= c->lpt_last);
283 		}
284 		done_lsave = 1;
285 		c->lsave_lnum = lnum;
286 		c->lsave_offs = offs;
287 		offs += c->lsave_sz;
288 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
289 	}
290 
291 	/* Make sure to place LPT's own lprops table */
292 	if (!done_ltab) {
293 		if (offs + c->ltab_sz > c->leb_size) {
294 			alen = ALIGN(offs, c->min_io_size);
295 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
296 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
297 			err = alloc_lpt_leb(c, &lnum);
298 			if (err)
299 				goto no_space;
300 			offs = 0;
301 			ubifs_assert(lnum >= c->lpt_first &&
302 				     lnum <= c->lpt_last);
303 		}
304 		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(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
320 		  lnum, offs, len, done_ltab, done_lsave);
321 	ubifs_dump_lpt_info(c);
322 	ubifs_dump_lpt_lebs(c);
323 	dump_stack();
324 	return err;
325 }
326 
327 #ifndef __UBOOT__
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);
417 				if (err)
418 					return err;
419 			}
420 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
421 			err = realloc_lpt_leb(c, &lnum);
422 			if (err)
423 				goto no_space;
424 			offs = from = 0;
425 			ubifs_assert(lnum >= c->lpt_first &&
426 				     lnum <= c->lpt_last);
427 			err = ubifs_leb_unmap(c, lnum);
428 			if (err)
429 				return err;
430 			/* Try to place lsave and ltab nicely */
431 			if (!done_lsave) {
432 				done_lsave = 1;
433 				ubifs_pack_lsave(c, buf + offs, c->lsave);
434 				offs += c->lsave_sz;
435 				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
436 				continue;
437 			}
438 			if (!done_ltab) {
439 				done_ltab = 1;
440 				ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
441 				offs += c->ltab_sz;
442 				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
443 				continue;
444 			}
445 			break;
446 		}
447 		if (cnode->level)
448 			ubifs_pack_nnode(c, buf + offs,
449 					 (struct ubifs_nnode *)cnode);
450 		else
451 			ubifs_pack_pnode(c, buf + offs,
452 					 (struct ubifs_pnode *)cnode);
453 		/*
454 		 * The reason for the barriers is the same as in case of TNC.
455 		 * See comment in 'write_index()'. 'dirty_cow_nnode()' and
456 		 * 'dirty_cow_pnode()' are the functions for which this is
457 		 * important.
458 		 */
459 		clear_bit(DIRTY_CNODE, &cnode->flags);
460 		smp_mb__before_atomic();
461 		clear_bit(COW_CNODE, &cnode->flags);
462 		smp_mb__after_atomic();
463 		offs += len;
464 		dbg_chk_lpt_sz(c, 1, len);
465 		cnode = cnode->cnext;
466 	} while (cnode && cnode != c->lpt_cnext);
467 
468 	/* Make sure to place LPT's save table */
469 	if (!done_lsave) {
470 		if (offs + c->lsave_sz > c->leb_size) {
471 			wlen = offs - from;
472 			alen = ALIGN(wlen, c->min_io_size);
473 			memset(buf + offs, 0xff, alen - wlen);
474 			err = ubifs_leb_write(c, lnum, buf + from, from, alen);
475 			if (err)
476 				return err;
477 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
478 			err = realloc_lpt_leb(c, &lnum);
479 			if (err)
480 				goto no_space;
481 			offs = from = 0;
482 			ubifs_assert(lnum >= c->lpt_first &&
483 				     lnum <= c->lpt_last);
484 			err = ubifs_leb_unmap(c, lnum);
485 			if (err)
486 				return err;
487 		}
488 		done_lsave = 1;
489 		ubifs_pack_lsave(c, buf + offs, c->lsave);
490 		offs += c->lsave_sz;
491 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
492 	}
493 
494 	/* Make sure to place LPT's own lprops table */
495 	if (!done_ltab) {
496 		if (offs + c->ltab_sz > c->leb_size) {
497 			wlen = offs - from;
498 			alen = ALIGN(wlen, c->min_io_size);
499 			memset(buf + offs, 0xff, alen - wlen);
500 			err = ubifs_leb_write(c, lnum, buf + from, from, alen);
501 			if (err)
502 				return err;
503 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
504 			err = realloc_lpt_leb(c, &lnum);
505 			if (err)
506 				goto no_space;
507 			offs = from = 0;
508 			ubifs_assert(lnum >= c->lpt_first &&
509 				     lnum <= c->lpt_last);
510 			err = ubifs_leb_unmap(c, lnum);
511 			if (err)
512 				return err;
513 		}
514 		ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
515 		offs += c->ltab_sz;
516 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
517 	}
518 
519 	/* Write remaining data in buffer */
520 	wlen = offs - from;
521 	alen = ALIGN(wlen, c->min_io_size);
522 	memset(buf + offs, 0xff, alen - wlen);
523 	err = ubifs_leb_write(c, lnum, buf + from, from, alen);
524 	if (err)
525 		return err;
526 
527 	dbg_chk_lpt_sz(c, 4, alen - wlen);
528 	err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
529 	if (err)
530 		return err;
531 
532 	c->nhead_lnum = lnum;
533 	c->nhead_offs = ALIGN(offs, c->min_io_size);
534 
535 	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
536 	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
537 	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
538 	if (c->big_lpt)
539 		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
540 
541 	return 0;
542 
543 no_space:
544 	ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
545 		  lnum, offs, len, done_ltab, done_lsave);
546 	ubifs_dump_lpt_info(c);
547 	ubifs_dump_lpt_lebs(c);
548 	dump_stack();
549 	return err;
550 }
551 #endif
552 
553 /**
554  * next_pnode_to_dirty - find next pnode to dirty.
555  * @c: UBIFS file-system description object
556  * @pnode: pnode
557  *
558  * This function returns the next pnode to dirty or %NULL if there are no more
559  * pnodes.  Note that pnodes that have never been written (lnum == 0) are
560  * skipped.
561  */
562 static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
563 					       struct ubifs_pnode *pnode)
564 {
565 	struct ubifs_nnode *nnode;
566 	int iip;
567 
568 	/* Try to go right */
569 	nnode = pnode->parent;
570 	for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
571 		if (nnode->nbranch[iip].lnum)
572 			return ubifs_get_pnode(c, nnode, iip);
573 	}
574 
575 	/* Go up while can't go right */
576 	do {
577 		iip = nnode->iip + 1;
578 		nnode = nnode->parent;
579 		if (!nnode)
580 			return NULL;
581 		for (; iip < UBIFS_LPT_FANOUT; iip++) {
582 			if (nnode->nbranch[iip].lnum)
583 				break;
584 		}
585 	} while (iip >= UBIFS_LPT_FANOUT);
586 
587 	/* Go right */
588 	nnode = ubifs_get_nnode(c, nnode, iip);
589 	if (IS_ERR(nnode))
590 		return (void *)nnode;
591 
592 	/* Go down to level 1 */
593 	while (nnode->level > 1) {
594 		for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
595 			if (nnode->nbranch[iip].lnum)
596 				break;
597 		}
598 		if (iip >= UBIFS_LPT_FANOUT) {
599 			/*
600 			 * Should not happen, but we need to keep going
601 			 * if it does.
602 			 */
603 			iip = 0;
604 		}
605 		nnode = ubifs_get_nnode(c, nnode, iip);
606 		if (IS_ERR(nnode))
607 			return (void *)nnode;
608 	}
609 
610 	for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
611 		if (nnode->nbranch[iip].lnum)
612 			break;
613 	if (iip >= UBIFS_LPT_FANOUT)
614 		/* Should not happen, but we need to keep going if it does */
615 		iip = 0;
616 	return ubifs_get_pnode(c, nnode, iip);
617 }
618 
619 /**
620  * pnode_lookup - lookup a pnode in the LPT.
621  * @c: UBIFS file-system description object
622  * @i: pnode number (0 to main_lebs - 1)
623  *
624  * This function returns a pointer to the pnode on success or a negative
625  * error code on failure.
626  */
627 static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
628 {
629 	int err, h, iip, shft;
630 	struct ubifs_nnode *nnode;
631 
632 	if (!c->nroot) {
633 		err = ubifs_read_nnode(c, NULL, 0);
634 		if (err)
635 			return ERR_PTR(err);
636 	}
637 	i <<= UBIFS_LPT_FANOUT_SHIFT;
638 	nnode = c->nroot;
639 	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
640 	for (h = 1; h < c->lpt_hght; h++) {
641 		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
642 		shft -= UBIFS_LPT_FANOUT_SHIFT;
643 		nnode = ubifs_get_nnode(c, nnode, iip);
644 		if (IS_ERR(nnode))
645 			return ERR_CAST(nnode);
646 	}
647 	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
648 	return ubifs_get_pnode(c, nnode, iip);
649 }
650 
651 /**
652  * add_pnode_dirt - add dirty space to LPT LEB properties.
653  * @c: UBIFS file-system description object
654  * @pnode: pnode for which to add dirt
655  */
656 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
657 {
658 	ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
659 			   c->pnode_sz);
660 }
661 
662 /**
663  * do_make_pnode_dirty - mark a pnode dirty.
664  * @c: UBIFS file-system description object
665  * @pnode: pnode to mark dirty
666  */
667 static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
668 {
669 	/* Assumes cnext list is empty i.e. not called during commit */
670 	if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
671 		struct ubifs_nnode *nnode;
672 
673 		c->dirty_pn_cnt += 1;
674 		add_pnode_dirt(c, pnode);
675 		/* Mark parent and ancestors dirty too */
676 		nnode = pnode->parent;
677 		while (nnode) {
678 			if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
679 				c->dirty_nn_cnt += 1;
680 				ubifs_add_nnode_dirt(c, nnode);
681 				nnode = nnode->parent;
682 			} else
683 				break;
684 		}
685 	}
686 }
687 
688 /**
689  * make_tree_dirty - mark the entire LEB properties tree dirty.
690  * @c: UBIFS file-system description object
691  *
692  * This function is used by the "small" LPT model to cause the entire LEB
693  * properties tree to be written.  The "small" LPT model does not use LPT
694  * garbage collection because it is more efficient to write the entire tree
695  * (because it is small).
696  *
697  * This function returns %0 on success and a negative error code on failure.
698  */
699 static int make_tree_dirty(struct ubifs_info *c)
700 {
701 	struct ubifs_pnode *pnode;
702 
703 	pnode = pnode_lookup(c, 0);
704 	if (IS_ERR(pnode))
705 		return PTR_ERR(pnode);
706 
707 	while (pnode) {
708 		do_make_pnode_dirty(c, pnode);
709 		pnode = next_pnode_to_dirty(c, pnode);
710 		if (IS_ERR(pnode))
711 			return PTR_ERR(pnode);
712 	}
713 	return 0;
714 }
715 
716 /**
717  * need_write_all - determine if the LPT area is running out of free space.
718  * @c: UBIFS file-system description object
719  *
720  * This function returns %1 if the LPT area is running out of free space and %0
721  * if it is not.
722  */
723 static int need_write_all(struct ubifs_info *c)
724 {
725 	long long free = 0;
726 	int i;
727 
728 	for (i = 0; i < c->lpt_lebs; i++) {
729 		if (i + c->lpt_first == c->nhead_lnum)
730 			free += c->leb_size - c->nhead_offs;
731 		else if (c->ltab[i].free == c->leb_size)
732 			free += c->leb_size;
733 		else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
734 			free += c->leb_size;
735 	}
736 	/* Less than twice the size left */
737 	if (free <= c->lpt_sz * 2)
738 		return 1;
739 	return 0;
740 }
741 
742 /**
743  * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
744  * @c: UBIFS file-system description object
745  *
746  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
747  * free space and so may be reused as soon as the next commit is completed.
748  * This function is called during start commit to mark LPT LEBs for trivial GC.
749  */
750 static void lpt_tgc_start(struct ubifs_info *c)
751 {
752 	int i;
753 
754 	for (i = 0; i < c->lpt_lebs; i++) {
755 		if (i + c->lpt_first == c->nhead_lnum)
756 			continue;
757 		if (c->ltab[i].dirty > 0 &&
758 		    c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
759 			c->ltab[i].tgc = 1;
760 			c->ltab[i].free = c->leb_size;
761 			c->ltab[i].dirty = 0;
762 			dbg_lp("LEB %d", i + c->lpt_first);
763 		}
764 	}
765 }
766 
767 /**
768  * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
769  * @c: UBIFS file-system description object
770  *
771  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
772  * free space and so may be reused as soon as the next commit is completed.
773  * This function is called after the commit is completed (master node has been
774  * written) and un-maps LPT LEBs that were marked for trivial GC.
775  */
776 static int lpt_tgc_end(struct ubifs_info *c)
777 {
778 	int i, err;
779 
780 	for (i = 0; i < c->lpt_lebs; i++)
781 		if (c->ltab[i].tgc) {
782 			err = ubifs_leb_unmap(c, i + c->lpt_first);
783 			if (err)
784 				return err;
785 			c->ltab[i].tgc = 0;
786 			dbg_lp("LEB %d", i + c->lpt_first);
787 		}
788 	return 0;
789 }
790 
791 /**
792  * populate_lsave - fill the lsave array with important LEB numbers.
793  * @c: the UBIFS file-system description object
794  *
795  * This function is only called for the "big" model. It records a small number
796  * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
797  * most important to least important): empty, freeable, freeable index, dirty
798  * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
799  * their pnodes into memory.  That will stop us from having to scan the LPT
800  * straight away. For the "small" model we assume that scanning the LPT is no
801  * big deal.
802  */
803 static void populate_lsave(struct ubifs_info *c)
804 {
805 	struct ubifs_lprops *lprops;
806 	struct ubifs_lpt_heap *heap;
807 	int i, cnt = 0;
808 
809 	ubifs_assert(c->big_lpt);
810 	if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
811 		c->lpt_drty_flgs |= LSAVE_DIRTY;
812 		ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
813 	}
814 
815 #ifndef __UBOOT__
816 	if (dbg_populate_lsave(c))
817 		return;
818 #endif
819 
820 	list_for_each_entry(lprops, &c->empty_list, list) {
821 		c->lsave[cnt++] = lprops->lnum;
822 		if (cnt >= c->lsave_cnt)
823 			return;
824 	}
825 	list_for_each_entry(lprops, &c->freeable_list, list) {
826 		c->lsave[cnt++] = lprops->lnum;
827 		if (cnt >= c->lsave_cnt)
828 			return;
829 	}
830 	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
831 		c->lsave[cnt++] = lprops->lnum;
832 		if (cnt >= c->lsave_cnt)
833 			return;
834 	}
835 	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
836 	for (i = 0; i < heap->cnt; i++) {
837 		c->lsave[cnt++] = heap->arr[i]->lnum;
838 		if (cnt >= c->lsave_cnt)
839 			return;
840 	}
841 	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
842 	for (i = 0; i < heap->cnt; i++) {
843 		c->lsave[cnt++] = heap->arr[i]->lnum;
844 		if (cnt >= c->lsave_cnt)
845 			return;
846 	}
847 	heap = &c->lpt_heap[LPROPS_FREE - 1];
848 	for (i = 0; i < heap->cnt; i++) {
849 		c->lsave[cnt++] = heap->arr[i]->lnum;
850 		if (cnt >= c->lsave_cnt)
851 			return;
852 	}
853 	/* Fill it up completely */
854 	while (cnt < c->lsave_cnt)
855 		c->lsave[cnt++] = c->main_first;
856 }
857 
858 /**
859  * nnode_lookup - lookup a nnode in the LPT.
860  * @c: UBIFS file-system description object
861  * @i: nnode number
862  *
863  * This function returns a pointer to the nnode on success or a negative
864  * error code on failure.
865  */
866 static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
867 {
868 	int err, iip;
869 	struct ubifs_nnode *nnode;
870 
871 	if (!c->nroot) {
872 		err = ubifs_read_nnode(c, NULL, 0);
873 		if (err)
874 			return ERR_PTR(err);
875 	}
876 	nnode = c->nroot;
877 	while (1) {
878 		iip = i & (UBIFS_LPT_FANOUT - 1);
879 		i >>= UBIFS_LPT_FANOUT_SHIFT;
880 		if (!i)
881 			break;
882 		nnode = ubifs_get_nnode(c, nnode, iip);
883 		if (IS_ERR(nnode))
884 			return nnode;
885 	}
886 	return nnode;
887 }
888 
889 /**
890  * make_nnode_dirty - find a nnode and, if found, make it dirty.
891  * @c: UBIFS file-system description object
892  * @node_num: nnode number of nnode to make dirty
893  * @lnum: LEB number where nnode was written
894  * @offs: offset where nnode was written
895  *
896  * This function is used by LPT garbage collection.  LPT garbage collection is
897  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
898  * simply involves marking all the nodes in the LEB being garbage-collected as
899  * dirty.  The dirty nodes are written next commit, after which the LEB is free
900  * to be reused.
901  *
902  * This function returns %0 on success and a negative error code on failure.
903  */
904 static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
905 			    int offs)
906 {
907 	struct ubifs_nnode *nnode;
908 
909 	nnode = nnode_lookup(c, node_num);
910 	if (IS_ERR(nnode))
911 		return PTR_ERR(nnode);
912 	if (nnode->parent) {
913 		struct ubifs_nbranch *branch;
914 
915 		branch = &nnode->parent->nbranch[nnode->iip];
916 		if (branch->lnum != lnum || branch->offs != offs)
917 			return 0; /* nnode is obsolete */
918 	} else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
919 			return 0; /* nnode is obsolete */
920 	/* Assumes cnext list is empty i.e. not called during commit */
921 	if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
922 		c->dirty_nn_cnt += 1;
923 		ubifs_add_nnode_dirt(c, nnode);
924 		/* Mark parent and ancestors dirty too */
925 		nnode = nnode->parent;
926 		while (nnode) {
927 			if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
928 				c->dirty_nn_cnt += 1;
929 				ubifs_add_nnode_dirt(c, nnode);
930 				nnode = nnode->parent;
931 			} else
932 				break;
933 		}
934 	}
935 	return 0;
936 }
937 
938 /**
939  * make_pnode_dirty - find a pnode and, if found, make it dirty.
940  * @c: UBIFS file-system description object
941  * @node_num: pnode number of pnode to make dirty
942  * @lnum: LEB number where pnode was written
943  * @offs: offset where pnode was written
944  *
945  * This function is used by LPT garbage collection.  LPT garbage collection is
946  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
947  * simply involves marking all the nodes in the LEB being garbage-collected as
948  * dirty.  The dirty nodes are written next commit, after which the LEB is free
949  * to be reused.
950  *
951  * This function returns %0 on success and a negative error code on failure.
952  */
953 static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
954 			    int offs)
955 {
956 	struct ubifs_pnode *pnode;
957 	struct ubifs_nbranch *branch;
958 
959 	pnode = pnode_lookup(c, node_num);
960 	if (IS_ERR(pnode))
961 		return PTR_ERR(pnode);
962 	branch = &pnode->parent->nbranch[pnode->iip];
963 	if (branch->lnum != lnum || branch->offs != offs)
964 		return 0;
965 	do_make_pnode_dirty(c, pnode);
966 	return 0;
967 }
968 
969 /**
970  * make_ltab_dirty - make ltab node dirty.
971  * @c: UBIFS file-system description object
972  * @lnum: LEB number where ltab was written
973  * @offs: offset where ltab was written
974  *
975  * This function is used by LPT garbage collection.  LPT garbage collection is
976  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
977  * simply involves marking all the nodes in the LEB being garbage-collected as
978  * dirty.  The dirty nodes are written next commit, after which the LEB is free
979  * to be reused.
980  *
981  * This function returns %0 on success and a negative error code on failure.
982  */
983 static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
984 {
985 	if (lnum != c->ltab_lnum || offs != c->ltab_offs)
986 		return 0; /* This ltab node is obsolete */
987 	if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
988 		c->lpt_drty_flgs |= LTAB_DIRTY;
989 		ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
990 	}
991 	return 0;
992 }
993 
994 /**
995  * make_lsave_dirty - make lsave node dirty.
996  * @c: UBIFS file-system description object
997  * @lnum: LEB number where lsave was written
998  * @offs: offset where lsave was written
999  *
1000  * This function is used by LPT garbage collection.  LPT garbage collection is
1001  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1002  * simply involves marking all the nodes in the LEB being garbage-collected as
1003  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1004  * to be reused.
1005  *
1006  * This function returns %0 on success and a negative error code on failure.
1007  */
1008 static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1009 {
1010 	if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1011 		return 0; /* This lsave node is obsolete */
1012 	if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
1013 		c->lpt_drty_flgs |= LSAVE_DIRTY;
1014 		ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
1015 	}
1016 	return 0;
1017 }
1018 
1019 /**
1020  * make_node_dirty - make node dirty.
1021  * @c: UBIFS file-system description object
1022  * @node_type: LPT node type
1023  * @node_num: node number
1024  * @lnum: LEB number where node was written
1025  * @offs: offset where node was written
1026  *
1027  * This function is used by LPT garbage collection.  LPT garbage collection is
1028  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
1029  * simply involves marking all the nodes in the LEB being garbage-collected as
1030  * dirty.  The dirty nodes are written next commit, after which the LEB is free
1031  * to be reused.
1032  *
1033  * This function returns %0 on success and a negative error code on failure.
1034  */
1035 static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
1036 			   int lnum, int offs)
1037 {
1038 	switch (node_type) {
1039 	case UBIFS_LPT_NNODE:
1040 		return make_nnode_dirty(c, node_num, lnum, offs);
1041 	case UBIFS_LPT_PNODE:
1042 		return make_pnode_dirty(c, node_num, lnum, offs);
1043 	case UBIFS_LPT_LTAB:
1044 		return make_ltab_dirty(c, lnum, offs);
1045 	case UBIFS_LPT_LSAVE:
1046 		return make_lsave_dirty(c, lnum, offs);
1047 	}
1048 	return -EINVAL;
1049 }
1050 
1051 /**
1052  * get_lpt_node_len - return the length of a node based on its type.
1053  * @c: UBIFS file-system description object
1054  * @node_type: LPT node type
1055  */
1056 static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
1057 {
1058 	switch (node_type) {
1059 	case UBIFS_LPT_NNODE:
1060 		return c->nnode_sz;
1061 	case UBIFS_LPT_PNODE:
1062 		return c->pnode_sz;
1063 	case UBIFS_LPT_LTAB:
1064 		return c->ltab_sz;
1065 	case UBIFS_LPT_LSAVE:
1066 		return c->lsave_sz;
1067 	}
1068 	return 0;
1069 }
1070 
1071 /**
1072  * get_pad_len - return the length of padding in a buffer.
1073  * @c: UBIFS file-system description object
1074  * @buf: buffer
1075  * @len: length of buffer
1076  */
1077 static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
1078 {
1079 	int offs, pad_len;
1080 
1081 	if (c->min_io_size == 1)
1082 		return 0;
1083 	offs = c->leb_size - len;
1084 	pad_len = ALIGN(offs, c->min_io_size) - offs;
1085 	return pad_len;
1086 }
1087 
1088 /**
1089  * get_lpt_node_type - return type (and node number) of a node in a buffer.
1090  * @c: UBIFS file-system description object
1091  * @buf: buffer
1092  * @node_num: node number is returned here
1093  */
1094 static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
1095 			     int *node_num)
1096 {
1097 	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1098 	int pos = 0, node_type;
1099 
1100 	node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1101 	*node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1102 	return node_type;
1103 }
1104 
1105 /**
1106  * is_a_node - determine if a buffer contains a node.
1107  * @c: UBIFS file-system description object
1108  * @buf: buffer
1109  * @len: length of buffer
1110  *
1111  * This function returns %1 if the buffer contains a node or %0 if it does not.
1112  */
1113 static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
1114 {
1115 	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1116 	int pos = 0, node_type, node_len;
1117 	uint16_t crc, calc_crc;
1118 
1119 	if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
1120 		return 0;
1121 	node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
1122 	if (node_type == UBIFS_LPT_NOT_A_NODE)
1123 		return 0;
1124 	node_len = get_lpt_node_len(c, node_type);
1125 	if (!node_len || node_len > len)
1126 		return 0;
1127 	pos = 0;
1128 	addr = buf;
1129 	crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
1130 	calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
1131 			 node_len - UBIFS_LPT_CRC_BYTES);
1132 	if (crc != calc_crc)
1133 		return 0;
1134 	return 1;
1135 }
1136 
1137 /**
1138  * lpt_gc_lnum - garbage collect a LPT LEB.
1139  * @c: UBIFS file-system description object
1140  * @lnum: LEB number to garbage collect
1141  *
1142  * LPT garbage collection is used only for the "big" LPT model
1143  * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
1144  * in the LEB being garbage-collected as dirty.  The dirty nodes are written
1145  * next commit, after which the LEB is free to be reused.
1146  *
1147  * This function returns %0 on success and a negative error code on failure.
1148  */
1149 static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
1150 {
1151 	int err, len = c->leb_size, node_type, node_num, node_len, offs;
1152 	void *buf = c->lpt_buf;
1153 
1154 	dbg_lp("LEB %d", lnum);
1155 
1156 	err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1157 	if (err)
1158 		return err;
1159 
1160 	while (1) {
1161 		if (!is_a_node(c, buf, len)) {
1162 			int pad_len;
1163 
1164 			pad_len = get_pad_len(c, buf, len);
1165 			if (pad_len) {
1166 				buf += pad_len;
1167 				len -= pad_len;
1168 				continue;
1169 			}
1170 			return 0;
1171 		}
1172 		node_type = get_lpt_node_type(c, buf, &node_num);
1173 		node_len = get_lpt_node_len(c, node_type);
1174 		offs = c->leb_size - len;
1175 		ubifs_assert(node_len != 0);
1176 		mutex_lock(&c->lp_mutex);
1177 		err = make_node_dirty(c, node_type, node_num, lnum, offs);
1178 		mutex_unlock(&c->lp_mutex);
1179 		if (err)
1180 			return err;
1181 		buf += node_len;
1182 		len -= node_len;
1183 	}
1184 	return 0;
1185 }
1186 
1187 /**
1188  * lpt_gc - LPT garbage collection.
1189  * @c: UBIFS file-system description object
1190  *
1191  * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
1192  * Returns %0 on success and a negative error code on failure.
1193  */
1194 static int lpt_gc(struct ubifs_info *c)
1195 {
1196 	int i, lnum = -1, dirty = 0;
1197 
1198 	mutex_lock(&c->lp_mutex);
1199 	for (i = 0; i < c->lpt_lebs; i++) {
1200 		ubifs_assert(!c->ltab[i].tgc);
1201 		if (i + c->lpt_first == c->nhead_lnum ||
1202 		    c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
1203 			continue;
1204 		if (c->ltab[i].dirty > dirty) {
1205 			dirty = c->ltab[i].dirty;
1206 			lnum = i + c->lpt_first;
1207 		}
1208 	}
1209 	mutex_unlock(&c->lp_mutex);
1210 	if (lnum == -1)
1211 		return -ENOSPC;
1212 	return lpt_gc_lnum(c, lnum);
1213 }
1214 
1215 /**
1216  * ubifs_lpt_start_commit - UBIFS commit starts.
1217  * @c: the UBIFS file-system description object
1218  *
1219  * This function has to be called when UBIFS starts the commit operation.
1220  * This function "freezes" all currently dirty LEB properties and does not
1221  * change them anymore. Further changes are saved and tracked separately
1222  * because they are not part of this commit. This function returns zero in case
1223  * of success and a negative error code in case of failure.
1224  */
1225 int ubifs_lpt_start_commit(struct ubifs_info *c)
1226 {
1227 	int err, cnt;
1228 
1229 	dbg_lp("");
1230 
1231 	mutex_lock(&c->lp_mutex);
1232 	err = dbg_chk_lpt_free_spc(c);
1233 	if (err)
1234 		goto out;
1235 	err = dbg_check_ltab(c);
1236 	if (err)
1237 		goto out;
1238 
1239 	if (c->check_lpt_free) {
1240 		/*
1241 		 * We ensure there is enough free space in
1242 		 * ubifs_lpt_post_commit() by marking nodes dirty. That
1243 		 * information is lost when we unmount, so we also need
1244 		 * to check free space once after mounting also.
1245 		 */
1246 		c->check_lpt_free = 0;
1247 		while (need_write_all(c)) {
1248 			mutex_unlock(&c->lp_mutex);
1249 			err = lpt_gc(c);
1250 			if (err)
1251 				return err;
1252 			mutex_lock(&c->lp_mutex);
1253 		}
1254 	}
1255 
1256 	lpt_tgc_start(c);
1257 
1258 	if (!c->dirty_pn_cnt) {
1259 		dbg_cmt("no cnodes to commit");
1260 		err = 0;
1261 		goto out;
1262 	}
1263 
1264 	if (!c->big_lpt && need_write_all(c)) {
1265 		/* If needed, write everything */
1266 		err = make_tree_dirty(c);
1267 		if (err)
1268 			goto out;
1269 		lpt_tgc_start(c);
1270 	}
1271 
1272 	if (c->big_lpt)
1273 		populate_lsave(c);
1274 
1275 	cnt = get_cnodes_to_commit(c);
1276 	ubifs_assert(cnt != 0);
1277 
1278 	err = layout_cnodes(c);
1279 	if (err)
1280 		goto out;
1281 
1282 	/* Copy the LPT's own lprops for end commit to write */
1283 	memcpy(c->ltab_cmt, c->ltab,
1284 	       sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1285 	c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
1286 
1287 out:
1288 	mutex_unlock(&c->lp_mutex);
1289 	return err;
1290 }
1291 
1292 /**
1293  * free_obsolete_cnodes - free obsolete cnodes for commit end.
1294  * @c: UBIFS file-system description object
1295  */
1296 static void free_obsolete_cnodes(struct ubifs_info *c)
1297 {
1298 	struct ubifs_cnode *cnode, *cnext;
1299 
1300 	cnext = c->lpt_cnext;
1301 	if (!cnext)
1302 		return;
1303 	do {
1304 		cnode = cnext;
1305 		cnext = cnode->cnext;
1306 		if (test_bit(OBSOLETE_CNODE, &cnode->flags))
1307 			kfree(cnode);
1308 		else
1309 			cnode->cnext = NULL;
1310 	} while (cnext != c->lpt_cnext);
1311 	c->lpt_cnext = NULL;
1312 }
1313 
1314 #ifndef __UBOOT__
1315 /**
1316  * ubifs_lpt_end_commit - finish the commit operation.
1317  * @c: the UBIFS file-system description object
1318  *
1319  * This function has to be called when the commit operation finishes. It
1320  * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1321  * the media. Returns zero in case of success and a negative error code in case
1322  * of failure.
1323  */
1324 int ubifs_lpt_end_commit(struct ubifs_info *c)
1325 {
1326 	int err;
1327 
1328 	dbg_lp("");
1329 
1330 	if (!c->lpt_cnext)
1331 		return 0;
1332 
1333 	err = write_cnodes(c);
1334 	if (err)
1335 		return err;
1336 
1337 	mutex_lock(&c->lp_mutex);
1338 	free_obsolete_cnodes(c);
1339 	mutex_unlock(&c->lp_mutex);
1340 
1341 	return 0;
1342 }
1343 #endif
1344 
1345 /**
1346  * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1347  * @c: UBIFS file-system description object
1348  *
1349  * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1350  * commit for the "big" LPT model.
1351  */
1352 int ubifs_lpt_post_commit(struct ubifs_info *c)
1353 {
1354 	int err;
1355 
1356 	mutex_lock(&c->lp_mutex);
1357 	err = lpt_tgc_end(c);
1358 	if (err)
1359 		goto out;
1360 	if (c->big_lpt)
1361 		while (need_write_all(c)) {
1362 			mutex_unlock(&c->lp_mutex);
1363 			err = lpt_gc(c);
1364 			if (err)
1365 				return err;
1366 			mutex_lock(&c->lp_mutex);
1367 		}
1368 out:
1369 	mutex_unlock(&c->lp_mutex);
1370 	return err;
1371 }
1372 
1373 /**
1374  * first_nnode - find the first nnode in memory.
1375  * @c: UBIFS file-system description object
1376  * @hght: height of tree where nnode found is returned here
1377  *
1378  * This function returns a pointer to the nnode found or %NULL if no nnode is
1379  * found. This function is a helper to 'ubifs_lpt_free()'.
1380  */
1381 static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1382 {
1383 	struct ubifs_nnode *nnode;
1384 	int h, i, found;
1385 
1386 	nnode = c->nroot;
1387 	*hght = 0;
1388 	if (!nnode)
1389 		return NULL;
1390 	for (h = 1; h < c->lpt_hght; h++) {
1391 		found = 0;
1392 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1393 			if (nnode->nbranch[i].nnode) {
1394 				found = 1;
1395 				nnode = nnode->nbranch[i].nnode;
1396 				*hght = h;
1397 				break;
1398 			}
1399 		}
1400 		if (!found)
1401 			break;
1402 	}
1403 	return nnode;
1404 }
1405 
1406 /**
1407  * next_nnode - find the next nnode in memory.
1408  * @c: UBIFS file-system description object
1409  * @nnode: nnode from which to start.
1410  * @hght: height of tree where nnode is, is passed and returned here
1411  *
1412  * This function returns a pointer to the nnode found or %NULL if no nnode is
1413  * found. This function is a helper to 'ubifs_lpt_free()'.
1414  */
1415 static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1416 				      struct ubifs_nnode *nnode, int *hght)
1417 {
1418 	struct ubifs_nnode *parent;
1419 	int iip, h, i, found;
1420 
1421 	parent = nnode->parent;
1422 	if (!parent)
1423 		return NULL;
1424 	if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1425 		*hght -= 1;
1426 		return parent;
1427 	}
1428 	for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1429 		nnode = parent->nbranch[iip].nnode;
1430 		if (nnode)
1431 			break;
1432 	}
1433 	if (!nnode) {
1434 		*hght -= 1;
1435 		return parent;
1436 	}
1437 	for (h = *hght + 1; h < c->lpt_hght; h++) {
1438 		found = 0;
1439 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1440 			if (nnode->nbranch[i].nnode) {
1441 				found = 1;
1442 				nnode = nnode->nbranch[i].nnode;
1443 				*hght = h;
1444 				break;
1445 			}
1446 		}
1447 		if (!found)
1448 			break;
1449 	}
1450 	return nnode;
1451 }
1452 
1453 /**
1454  * ubifs_lpt_free - free resources owned by the LPT.
1455  * @c: UBIFS file-system description object
1456  * @wr_only: free only resources used for writing
1457  */
1458 void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1459 {
1460 	struct ubifs_nnode *nnode;
1461 	int i, hght;
1462 
1463 	/* Free write-only things first */
1464 
1465 	free_obsolete_cnodes(c); /* Leftover from a failed commit */
1466 
1467 	vfree(c->ltab_cmt);
1468 	c->ltab_cmt = NULL;
1469 	vfree(c->lpt_buf);
1470 	c->lpt_buf = NULL;
1471 	kfree(c->lsave);
1472 	c->lsave = NULL;
1473 
1474 	if (wr_only)
1475 		return;
1476 
1477 	/* Now free the rest */
1478 
1479 	nnode = first_nnode(c, &hght);
1480 	while (nnode) {
1481 		for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1482 			kfree(nnode->nbranch[i].nnode);
1483 		nnode = next_nnode(c, nnode, &hght);
1484 	}
1485 	for (i = 0; i < LPROPS_HEAP_CNT; i++)
1486 		kfree(c->lpt_heap[i].arr);
1487 	kfree(c->dirty_idx.arr);
1488 	kfree(c->nroot);
1489 	vfree(c->ltab);
1490 	kfree(c->lpt_nod_buf);
1491 }
1492 
1493 #ifndef __UBOOT__
1494 /*
1495  * Everything below is related to debugging.
1496  */
1497 
1498 /**
1499  * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1500  * @buf: buffer
1501  * @len: buffer length
1502  */
1503 static int dbg_is_all_ff(uint8_t *buf, int len)
1504 {
1505 	int i;
1506 
1507 	for (i = 0; i < len; i++)
1508 		if (buf[i] != 0xff)
1509 			return 0;
1510 	return 1;
1511 }
1512 
1513 /**
1514  * dbg_is_nnode_dirty - determine if a nnode is dirty.
1515  * @c: the UBIFS file-system description object
1516  * @lnum: LEB number where nnode was written
1517  * @offs: offset where nnode was written
1518  */
1519 static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1520 {
1521 	struct ubifs_nnode *nnode;
1522 	int hght;
1523 
1524 	/* Entire tree is in memory so first_nnode / next_nnode are OK */
1525 	nnode = first_nnode(c, &hght);
1526 	for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1527 		struct ubifs_nbranch *branch;
1528 
1529 		cond_resched();
1530 		if (nnode->parent) {
1531 			branch = &nnode->parent->nbranch[nnode->iip];
1532 			if (branch->lnum != lnum || branch->offs != offs)
1533 				continue;
1534 			if (test_bit(DIRTY_CNODE, &nnode->flags))
1535 				return 1;
1536 			return 0;
1537 		} else {
1538 			if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1539 				continue;
1540 			if (test_bit(DIRTY_CNODE, &nnode->flags))
1541 				return 1;
1542 			return 0;
1543 		}
1544 	}
1545 	return 1;
1546 }
1547 
1548 /**
1549  * dbg_is_pnode_dirty - determine if a pnode is dirty.
1550  * @c: the UBIFS file-system description object
1551  * @lnum: LEB number where pnode was written
1552  * @offs: offset where pnode was written
1553  */
1554 static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1555 {
1556 	int i, cnt;
1557 
1558 	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1559 	for (i = 0; i < cnt; i++) {
1560 		struct ubifs_pnode *pnode;
1561 		struct ubifs_nbranch *branch;
1562 
1563 		cond_resched();
1564 		pnode = pnode_lookup(c, i);
1565 		if (IS_ERR(pnode))
1566 			return PTR_ERR(pnode);
1567 		branch = &pnode->parent->nbranch[pnode->iip];
1568 		if (branch->lnum != lnum || branch->offs != offs)
1569 			continue;
1570 		if (test_bit(DIRTY_CNODE, &pnode->flags))
1571 			return 1;
1572 		return 0;
1573 	}
1574 	return 1;
1575 }
1576 
1577 /**
1578  * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1579  * @c: the UBIFS file-system description object
1580  * @lnum: LEB number where ltab node was written
1581  * @offs: offset where ltab node was written
1582  */
1583 static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1584 {
1585 	if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1586 		return 1;
1587 	return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1588 }
1589 
1590 /**
1591  * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1592  * @c: the UBIFS file-system description object
1593  * @lnum: LEB number where lsave node was written
1594  * @offs: offset where lsave node was written
1595  */
1596 static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1597 {
1598 	if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1599 		return 1;
1600 	return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1601 }
1602 
1603 /**
1604  * dbg_is_node_dirty - determine if a node is dirty.
1605  * @c: the UBIFS file-system description object
1606  * @node_type: node type
1607  * @lnum: LEB number where node was written
1608  * @offs: offset where node was written
1609  */
1610 static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1611 			     int offs)
1612 {
1613 	switch (node_type) {
1614 	case UBIFS_LPT_NNODE:
1615 		return dbg_is_nnode_dirty(c, lnum, offs);
1616 	case UBIFS_LPT_PNODE:
1617 		return dbg_is_pnode_dirty(c, lnum, offs);
1618 	case UBIFS_LPT_LTAB:
1619 		return dbg_is_ltab_dirty(c, lnum, offs);
1620 	case UBIFS_LPT_LSAVE:
1621 		return dbg_is_lsave_dirty(c, lnum, offs);
1622 	}
1623 	return 1;
1624 }
1625 
1626 /**
1627  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1628  * @c: the UBIFS file-system description object
1629  * @lnum: LEB number where node was written
1630  * @offs: offset where node was written
1631  *
1632  * This function returns %0 on success and a negative error code on failure.
1633  */
1634 static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1635 {
1636 	int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1637 	int ret;
1638 	void *buf, *p;
1639 
1640 	if (!dbg_is_chk_lprops(c))
1641 		return 0;
1642 
1643 	buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1644 	if (!buf) {
1645 		ubifs_err(c, "cannot allocate memory for ltab checking");
1646 		return 0;
1647 	}
1648 
1649 	dbg_lp("LEB %d", lnum);
1650 
1651 	err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1652 	if (err)
1653 		goto out;
1654 
1655 	while (1) {
1656 		if (!is_a_node(c, p, len)) {
1657 			int i, pad_len;
1658 
1659 			pad_len = get_pad_len(c, p, len);
1660 			if (pad_len) {
1661 				p += pad_len;
1662 				len -= pad_len;
1663 				dirty += pad_len;
1664 				continue;
1665 			}
1666 			if (!dbg_is_all_ff(p, len)) {
1667 				ubifs_err(c, "invalid empty space in LEB %d at %d",
1668 					  lnum, c->leb_size - len);
1669 				err = -EINVAL;
1670 			}
1671 			i = lnum - c->lpt_first;
1672 			if (len != c->ltab[i].free) {
1673 				ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)",
1674 					  lnum, len, c->ltab[i].free);
1675 				err = -EINVAL;
1676 			}
1677 			if (dirty != c->ltab[i].dirty) {
1678 				ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)",
1679 					  lnum, dirty, c->ltab[i].dirty);
1680 				err = -EINVAL;
1681 			}
1682 			goto out;
1683 		}
1684 		node_type = get_lpt_node_type(c, p, &node_num);
1685 		node_len = get_lpt_node_len(c, node_type);
1686 		ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1687 		if (ret == 1)
1688 			dirty += node_len;
1689 		p += node_len;
1690 		len -= node_len;
1691 	}
1692 
1693 	err = 0;
1694 out:
1695 	vfree(buf);
1696 	return err;
1697 }
1698 
1699 /**
1700  * dbg_check_ltab - check the free and dirty space in the ltab.
1701  * @c: the UBIFS file-system description object
1702  *
1703  * This function returns %0 on success and a negative error code on failure.
1704  */
1705 int dbg_check_ltab(struct ubifs_info *c)
1706 {
1707 	int lnum, err, i, cnt;
1708 
1709 	if (!dbg_is_chk_lprops(c))
1710 		return 0;
1711 
1712 	/* Bring the entire tree into memory */
1713 	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1714 	for (i = 0; i < cnt; i++) {
1715 		struct ubifs_pnode *pnode;
1716 
1717 		pnode = pnode_lookup(c, i);
1718 		if (IS_ERR(pnode))
1719 			return PTR_ERR(pnode);
1720 		cond_resched();
1721 	}
1722 
1723 	/* Check nodes */
1724 	err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1725 	if (err)
1726 		return err;
1727 
1728 	/* Check each LEB */
1729 	for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1730 		err = dbg_check_ltab_lnum(c, lnum);
1731 		if (err) {
1732 			ubifs_err(c, "failed at LEB %d", lnum);
1733 			return err;
1734 		}
1735 	}
1736 
1737 	dbg_lp("succeeded");
1738 	return 0;
1739 }
1740 
1741 /**
1742  * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1743  * @c: the UBIFS file-system description object
1744  *
1745  * This function returns %0 on success and a negative error code on failure.
1746  */
1747 int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1748 {
1749 	long long free = 0;
1750 	int i;
1751 
1752 	if (!dbg_is_chk_lprops(c))
1753 		return 0;
1754 
1755 	for (i = 0; i < c->lpt_lebs; i++) {
1756 		if (c->ltab[i].tgc || c->ltab[i].cmt)
1757 			continue;
1758 		if (i + c->lpt_first == c->nhead_lnum)
1759 			free += c->leb_size - c->nhead_offs;
1760 		else if (c->ltab[i].free == c->leb_size)
1761 			free += c->leb_size;
1762 	}
1763 	if (free < c->lpt_sz) {
1764 		ubifs_err(c, "LPT space error: free %lld lpt_sz %lld",
1765 			  free, c->lpt_sz);
1766 		ubifs_dump_lpt_info(c);
1767 		ubifs_dump_lpt_lebs(c);
1768 		dump_stack();
1769 		return -EINVAL;
1770 	}
1771 	return 0;
1772 }
1773 
1774 /**
1775  * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1776  * @c: the UBIFS file-system description object
1777  * @action: what to do
1778  * @len: length written
1779  *
1780  * This function returns %0 on success and a negative error code on failure.
1781  * The @action argument may be one of:
1782  *   o %0 - LPT debugging checking starts, initialize debugging variables;
1783  *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1784  *   o %2 - switched to a different LEB and wasted @len bytes;
1785  *   o %3 - check that we've written the right number of bytes.
1786  *   o %4 - wasted @len bytes;
1787  */
1788 int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1789 {
1790 	struct ubifs_debug_info *d = c->dbg;
1791 	long long chk_lpt_sz, lpt_sz;
1792 	int err = 0;
1793 
1794 	if (!dbg_is_chk_lprops(c))
1795 		return 0;
1796 
1797 	switch (action) {
1798 	case 0:
1799 		d->chk_lpt_sz = 0;
1800 		d->chk_lpt_sz2 = 0;
1801 		d->chk_lpt_lebs = 0;
1802 		d->chk_lpt_wastage = 0;
1803 		if (c->dirty_pn_cnt > c->pnode_cnt) {
1804 			ubifs_err(c, "dirty pnodes %d exceed max %d",
1805 				  c->dirty_pn_cnt, c->pnode_cnt);
1806 			err = -EINVAL;
1807 		}
1808 		if (c->dirty_nn_cnt > c->nnode_cnt) {
1809 			ubifs_err(c, "dirty nnodes %d exceed max %d",
1810 				  c->dirty_nn_cnt, c->nnode_cnt);
1811 			err = -EINVAL;
1812 		}
1813 		return err;
1814 	case 1:
1815 		d->chk_lpt_sz += len;
1816 		return 0;
1817 	case 2:
1818 		d->chk_lpt_sz += len;
1819 		d->chk_lpt_wastage += len;
1820 		d->chk_lpt_lebs += 1;
1821 		return 0;
1822 	case 3:
1823 		chk_lpt_sz = c->leb_size;
1824 		chk_lpt_sz *= d->chk_lpt_lebs;
1825 		chk_lpt_sz += len - c->nhead_offs;
1826 		if (d->chk_lpt_sz != chk_lpt_sz) {
1827 			ubifs_err(c, "LPT wrote %lld but space used was %lld",
1828 				  d->chk_lpt_sz, chk_lpt_sz);
1829 			err = -EINVAL;
1830 		}
1831 		if (d->chk_lpt_sz > c->lpt_sz) {
1832 			ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld",
1833 				  d->chk_lpt_sz, c->lpt_sz);
1834 			err = -EINVAL;
1835 		}
1836 		if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1837 			ubifs_err(c, "LPT layout size %lld but wrote %lld",
1838 				  d->chk_lpt_sz, d->chk_lpt_sz2);
1839 			err = -EINVAL;
1840 		}
1841 		if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1842 			ubifs_err(c, "LPT new nhead offs: expected %d was %d",
1843 				  d->new_nhead_offs, len);
1844 			err = -EINVAL;
1845 		}
1846 		lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1847 		lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1848 		lpt_sz += c->ltab_sz;
1849 		if (c->big_lpt)
1850 			lpt_sz += c->lsave_sz;
1851 		if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1852 			ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1853 				  d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1854 			err = -EINVAL;
1855 		}
1856 		if (err) {
1857 			ubifs_dump_lpt_info(c);
1858 			ubifs_dump_lpt_lebs(c);
1859 			dump_stack();
1860 		}
1861 		d->chk_lpt_sz2 = d->chk_lpt_sz;
1862 		d->chk_lpt_sz = 0;
1863 		d->chk_lpt_wastage = 0;
1864 		d->chk_lpt_lebs = 0;
1865 		d->new_nhead_offs = len;
1866 		return err;
1867 	case 4:
1868 		d->chk_lpt_sz += len;
1869 		d->chk_lpt_wastage += len;
1870 		return 0;
1871 	default:
1872 		return -EINVAL;
1873 	}
1874 }
1875 
1876 /**
1877  * ubifs_dump_lpt_leb - dump an LPT LEB.
1878  * @c: UBIFS file-system description object
1879  * @lnum: LEB number to dump
1880  *
1881  * This function dumps an LEB from LPT area. Nodes in this area are very
1882  * different to nodes in the main area (e.g., they do not have common headers,
1883  * they do not have 8-byte alignments, etc), so we have a separate function to
1884  * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1885  */
1886 static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1887 {
1888 	int err, len = c->leb_size, node_type, node_num, node_len, offs;
1889 	void *buf, *p;
1890 
1891 	pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
1892 	buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1893 	if (!buf) {
1894 		ubifs_err(c, "cannot allocate memory to dump LPT");
1895 		return;
1896 	}
1897 
1898 	err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1899 	if (err)
1900 		goto out;
1901 
1902 	while (1) {
1903 		offs = c->leb_size - len;
1904 		if (!is_a_node(c, p, len)) {
1905 			int pad_len;
1906 
1907 			pad_len = get_pad_len(c, p, len);
1908 			if (pad_len) {
1909 				pr_err("LEB %d:%d, pad %d bytes\n",
1910 				       lnum, offs, pad_len);
1911 				p += pad_len;
1912 				len -= pad_len;
1913 				continue;
1914 			}
1915 			if (len)
1916 				pr_err("LEB %d:%d, free %d bytes\n",
1917 				       lnum, offs, len);
1918 			break;
1919 		}
1920 
1921 		node_type = get_lpt_node_type(c, p, &node_num);
1922 		switch (node_type) {
1923 		case UBIFS_LPT_PNODE:
1924 		{
1925 			node_len = c->pnode_sz;
1926 			if (c->big_lpt)
1927 				pr_err("LEB %d:%d, pnode num %d\n",
1928 				       lnum, offs, node_num);
1929 			else
1930 				pr_err("LEB %d:%d, pnode\n", lnum, offs);
1931 			break;
1932 		}
1933 		case UBIFS_LPT_NNODE:
1934 		{
1935 			int i;
1936 			struct ubifs_nnode nnode;
1937 
1938 			node_len = c->nnode_sz;
1939 			if (c->big_lpt)
1940 				pr_err("LEB %d:%d, nnode num %d, ",
1941 				       lnum, offs, node_num);
1942 			else
1943 				pr_err("LEB %d:%d, nnode, ",
1944 				       lnum, offs);
1945 			err = ubifs_unpack_nnode(c, p, &nnode);
1946 			if (err) {
1947 				pr_err("failed to unpack_node, error %d\n",
1948 				       err);
1949 				break;
1950 			}
1951 			for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1952 				pr_cont("%d:%d", nnode.nbranch[i].lnum,
1953 				       nnode.nbranch[i].offs);
1954 				if (i != UBIFS_LPT_FANOUT - 1)
1955 					pr_cont(", ");
1956 			}
1957 			pr_cont("\n");
1958 			break;
1959 		}
1960 		case UBIFS_LPT_LTAB:
1961 			node_len = c->ltab_sz;
1962 			pr_err("LEB %d:%d, ltab\n", lnum, offs);
1963 			break;
1964 		case UBIFS_LPT_LSAVE:
1965 			node_len = c->lsave_sz;
1966 			pr_err("LEB %d:%d, lsave len\n", lnum, offs);
1967 			break;
1968 		default:
1969 			ubifs_err(c, "LPT node type %d not recognized", node_type);
1970 			goto out;
1971 		}
1972 
1973 		p += node_len;
1974 		len -= node_len;
1975 	}
1976 
1977 	pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
1978 out:
1979 	vfree(buf);
1980 	return;
1981 }
1982 
1983 /**
1984  * ubifs_dump_lpt_lebs - dump LPT lebs.
1985  * @c: UBIFS file-system description object
1986  *
1987  * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1988  * locked.
1989  */
1990 void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
1991 {
1992 	int i;
1993 
1994 	pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid);
1995 	for (i = 0; i < c->lpt_lebs; i++)
1996 		dump_lpt_leb(c, i + c->lpt_first);
1997 	pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid);
1998 }
1999 
2000 /**
2001  * dbg_populate_lsave - debugging version of 'populate_lsave()'
2002  * @c: UBIFS file-system description object
2003  *
2004  * This is a debugging version for 'populate_lsave()' which populates lsave
2005  * with random LEBs instead of useful LEBs, which is good for test coverage.
2006  * Returns zero if lsave has not been populated (this debugging feature is
2007  * disabled) an non-zero if lsave has been populated.
2008  */
2009 static int dbg_populate_lsave(struct ubifs_info *c)
2010 {
2011 	struct ubifs_lprops *lprops;
2012 	struct ubifs_lpt_heap *heap;
2013 	int i;
2014 
2015 	if (!dbg_is_chk_gen(c))
2016 		return 0;
2017 	if (prandom_u32() & 3)
2018 		return 0;
2019 
2020 	for (i = 0; i < c->lsave_cnt; i++)
2021 		c->lsave[i] = c->main_first;
2022 
2023 	list_for_each_entry(lprops, &c->empty_list, list)
2024 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2025 	list_for_each_entry(lprops, &c->freeable_list, list)
2026 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2027 	list_for_each_entry(lprops, &c->frdi_idx_list, list)
2028 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2029 
2030 	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
2031 	for (i = 0; i < heap->cnt; i++)
2032 		c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2033 	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
2034 	for (i = 0; i < heap->cnt; i++)
2035 		c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2036 	heap = &c->lpt_heap[LPROPS_FREE - 1];
2037 	for (i = 0; i < heap->cnt; i++)
2038 		c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2039 
2040 	return 1;
2041 }
2042 #endif
2043