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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  *
7  * Authors: Adrian Hunter
8  *          Artem Bityutskiy (Битюцкий Артём)
9  */
10 
11 /*
12  * This file implements commit-related functionality of the LEB properties
13  * subsystem.
14  */
15 
16 #ifndef __UBOOT__
17 #include <linux/crc16.h>
18 #include <linux/slab.h>
19 #include <linux/random.h>
20 #else
21 #include <linux/compat.h>
22 #include <linux/err.h>
23 #include "crc16.h"
24 #endif
25 #include "ubifs.h"
26 
27 #ifndef __UBOOT__
28 static int dbg_populate_lsave(struct ubifs_info *c);
29 #endif
30 
31 /**
32  * first_dirty_cnode - find first dirty cnode.
33  * @c: UBIFS file-system description object
34  * @nnode: nnode at which to start
35  *
36  * This function returns the first dirty cnode or %NULL if there is not one.
37  */
first_dirty_cnode(struct ubifs_nnode * nnode)38 static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
39 {
40 	ubifs_assert(nnode);
41 	while (1) {
42 		int i, cont = 0;
43 
44 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
45 			struct ubifs_cnode *cnode;
46 
47 			cnode = nnode->nbranch[i].cnode;
48 			if (cnode &&
49 			    test_bit(DIRTY_CNODE, &cnode->flags)) {
50 				if (cnode->level == 0)
51 					return cnode;
52 				nnode = (struct ubifs_nnode *)cnode;
53 				cont = 1;
54 				break;
55 			}
56 		}
57 		if (!cont)
58 			return (struct ubifs_cnode *)nnode;
59 	}
60 }
61 
62 /**
63  * next_dirty_cnode - find next dirty cnode.
64  * @cnode: cnode from which to begin searching
65  *
66  * This function returns the next dirty cnode or %NULL if there is not one.
67  */
next_dirty_cnode(struct ubifs_cnode * cnode)68 static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
69 {
70 	struct ubifs_nnode *nnode;
71 	int i;
72 
73 	ubifs_assert(cnode);
74 	nnode = cnode->parent;
75 	if (!nnode)
76 		return NULL;
77 	for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
78 		cnode = nnode->nbranch[i].cnode;
79 		if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
80 			if (cnode->level == 0)
81 				return cnode; /* cnode is a pnode */
82 			/* cnode is a nnode */
83 			return first_dirty_cnode((struct ubifs_nnode *)cnode);
84 		}
85 	}
86 	return (struct ubifs_cnode *)nnode;
87 }
88 
89 /**
90  * get_cnodes_to_commit - create list of dirty cnodes to commit.
91  * @c: UBIFS file-system description object
92  *
93  * This function returns the number of cnodes to commit.
94  */
get_cnodes_to_commit(struct ubifs_info * c)95 static int get_cnodes_to_commit(struct ubifs_info *c)
96 {
97 	struct ubifs_cnode *cnode, *cnext;
98 	int cnt = 0;
99 
100 	if (!c->nroot)
101 		return 0;
102 
103 	if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
104 		return 0;
105 
106 	c->lpt_cnext = first_dirty_cnode(c->nroot);
107 	cnode = c->lpt_cnext;
108 	if (!cnode)
109 		return 0;
110 	cnt += 1;
111 	while (1) {
112 		ubifs_assert(!test_bit(COW_CNODE, &cnode->flags));
113 		__set_bit(COW_CNODE, &cnode->flags);
114 		cnext = next_dirty_cnode(cnode);
115 		if (!cnext) {
116 			cnode->cnext = c->lpt_cnext;
117 			break;
118 		}
119 		cnode->cnext = cnext;
120 		cnode = cnext;
121 		cnt += 1;
122 	}
123 	dbg_cmt("committing %d cnodes", cnt);
124 	dbg_lp("committing %d cnodes", cnt);
125 	ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
126 	return cnt;
127 }
128 
129 /**
130  * upd_ltab - update LPT LEB properties.
131  * @c: UBIFS file-system description object
132  * @lnum: LEB number
133  * @free: amount of free space
134  * @dirty: amount of dirty space to add
135  */
upd_ltab(struct ubifs_info * c,int lnum,int free,int dirty)136 static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
137 {
138 	dbg_lp("LEB %d free %d dirty %d to %d +%d",
139 	       lnum, c->ltab[lnum - c->lpt_first].free,
140 	       c->ltab[lnum - c->lpt_first].dirty, free, dirty);
141 	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
142 	c->ltab[lnum - c->lpt_first].free = free;
143 	c->ltab[lnum - c->lpt_first].dirty += dirty;
144 }
145 
146 /**
147  * alloc_lpt_leb - allocate an LPT LEB that is empty.
148  * @c: UBIFS file-system description object
149  * @lnum: LEB number is passed and returned here
150  *
151  * This function finds the next empty LEB in the ltab starting from @lnum. If a
152  * an empty LEB is found it is returned in @lnum and the function returns %0.
153  * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
154  * never to run out of space.
155  */
alloc_lpt_leb(struct ubifs_info * c,int * lnum)156 static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
157 {
158 	int i, n;
159 
160 	n = *lnum - c->lpt_first + 1;
161 	for (i = n; i < c->lpt_lebs; i++) {
162 		if (c->ltab[i].tgc || c->ltab[i].cmt)
163 			continue;
164 		if (c->ltab[i].free == c->leb_size) {
165 			c->ltab[i].cmt = 1;
166 			*lnum = i + c->lpt_first;
167 			return 0;
168 		}
169 	}
170 
171 	for (i = 0; i < n; i++) {
172 		if (c->ltab[i].tgc || c->ltab[i].cmt)
173 			continue;
174 		if (c->ltab[i].free == c->leb_size) {
175 			c->ltab[i].cmt = 1;
176 			*lnum = i + c->lpt_first;
177 			return 0;
178 		}
179 	}
180 	return -ENOSPC;
181 }
182 
183 /**
184  * layout_cnodes - layout cnodes for commit.
185  * @c: UBIFS file-system description object
186  *
187  * This function returns %0 on success and a negative error code on failure.
188  */
layout_cnodes(struct ubifs_info * c)189 static int layout_cnodes(struct ubifs_info *c)
190 {
191 	int lnum, offs, len, alen, done_lsave, done_ltab, err;
192 	struct ubifs_cnode *cnode;
193 
194 	err = dbg_chk_lpt_sz(c, 0, 0);
195 	if (err)
196 		return err;
197 	cnode = c->lpt_cnext;
198 	if (!cnode)
199 		return 0;
200 	lnum = c->nhead_lnum;
201 	offs = c->nhead_offs;
202 	/* Try to place lsave and ltab nicely */
203 	done_lsave = !c->big_lpt;
204 	done_ltab = 0;
205 	if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
206 		done_lsave = 1;
207 		c->lsave_lnum = lnum;
208 		c->lsave_offs = offs;
209 		offs += c->lsave_sz;
210 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
211 	}
212 
213 	if (offs + c->ltab_sz <= c->leb_size) {
214 		done_ltab = 1;
215 		c->ltab_lnum = lnum;
216 		c->ltab_offs = offs;
217 		offs += c->ltab_sz;
218 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
219 	}
220 
221 	do {
222 		if (cnode->level) {
223 			len = c->nnode_sz;
224 			c->dirty_nn_cnt -= 1;
225 		} else {
226 			len = c->pnode_sz;
227 			c->dirty_pn_cnt -= 1;
228 		}
229 		while (offs + len > c->leb_size) {
230 			alen = ALIGN(offs, c->min_io_size);
231 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
232 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
233 			err = alloc_lpt_leb(c, &lnum);
234 			if (err)
235 				goto no_space;
236 			offs = 0;
237 			ubifs_assert(lnum >= c->lpt_first &&
238 				     lnum <= c->lpt_last);
239 			/* Try to place lsave and ltab nicely */
240 			if (!done_lsave) {
241 				done_lsave = 1;
242 				c->lsave_lnum = lnum;
243 				c->lsave_offs = offs;
244 				offs += c->lsave_sz;
245 				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
246 				continue;
247 			}
248 			if (!done_ltab) {
249 				done_ltab = 1;
250 				c->ltab_lnum = lnum;
251 				c->ltab_offs = offs;
252 				offs += c->ltab_sz;
253 				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
254 				continue;
255 			}
256 			break;
257 		}
258 		if (cnode->parent) {
259 			cnode->parent->nbranch[cnode->iip].lnum = lnum;
260 			cnode->parent->nbranch[cnode->iip].offs = offs;
261 		} else {
262 			c->lpt_lnum = lnum;
263 			c->lpt_offs = offs;
264 		}
265 		offs += len;
266 		dbg_chk_lpt_sz(c, 1, len);
267 		cnode = cnode->cnext;
268 	} while (cnode && cnode != c->lpt_cnext);
269 
270 	/* Make sure to place LPT's save table */
271 	if (!done_lsave) {
272 		if (offs + c->lsave_sz > c->leb_size) {
273 			alen = ALIGN(offs, c->min_io_size);
274 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
275 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
276 			err = alloc_lpt_leb(c, &lnum);
277 			if (err)
278 				goto no_space;
279 			offs = 0;
280 			ubifs_assert(lnum >= c->lpt_first &&
281 				     lnum <= c->lpt_last);
282 		}
283 		done_lsave = 1;
284 		c->lsave_lnum = lnum;
285 		c->lsave_offs = offs;
286 		offs += c->lsave_sz;
287 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
288 	}
289 
290 	/* Make sure to place LPT's own lprops table */
291 	if (!done_ltab) {
292 		if (offs + c->ltab_sz > c->leb_size) {
293 			alen = ALIGN(offs, c->min_io_size);
294 			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
295 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
296 			err = alloc_lpt_leb(c, &lnum);
297 			if (err)
298 				goto no_space;
299 			offs = 0;
300 			ubifs_assert(lnum >= c->lpt_first &&
301 				     lnum <= c->lpt_last);
302 		}
303 		c->ltab_lnum = lnum;
304 		c->ltab_offs = offs;
305 		offs += c->ltab_sz;
306 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
307 	}
308 
309 	alen = ALIGN(offs, c->min_io_size);
310 	upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
311 	dbg_chk_lpt_sz(c, 4, alen - offs);
312 	err = dbg_chk_lpt_sz(c, 3, alen);
313 	if (err)
314 		return err;
315 	return 0;
316 
317 no_space:
318 	ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
319 		  lnum, offs, len, done_ltab, done_lsave);
320 	ubifs_dump_lpt_info(c);
321 	ubifs_dump_lpt_lebs(c);
322 	dump_stack();
323 	return err;
324 }
325 
326 #ifndef __UBOOT__
327 /**
328  * realloc_lpt_leb - allocate an LPT LEB that is empty.
329  * @c: UBIFS file-system description object
330  * @lnum: LEB number is passed and returned here
331  *
332  * This function duplicates exactly the results of the function alloc_lpt_leb.
333  * It is used during end commit to reallocate the same LEB numbers that were
334  * allocated by alloc_lpt_leb during start commit.
335  *
336  * This function finds the next LEB that was allocated by the alloc_lpt_leb
337  * function starting from @lnum. If a LEB is found it is returned in @lnum and
338  * the function returns %0. Otherwise the function returns -ENOSPC.
339  * Note however, that LPT is designed never to run out of space.
340  */
realloc_lpt_leb(struct ubifs_info * c,int * lnum)341 static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
342 {
343 	int i, n;
344 
345 	n = *lnum - c->lpt_first + 1;
346 	for (i = n; i < c->lpt_lebs; i++)
347 		if (c->ltab[i].cmt) {
348 			c->ltab[i].cmt = 0;
349 			*lnum = i + c->lpt_first;
350 			return 0;
351 		}
352 
353 	for (i = 0; i < n; i++)
354 		if (c->ltab[i].cmt) {
355 			c->ltab[i].cmt = 0;
356 			*lnum = i + c->lpt_first;
357 			return 0;
358 		}
359 	return -ENOSPC;
360 }
361 
362 /**
363  * write_cnodes - write cnodes for commit.
364  * @c: UBIFS file-system description object
365  *
366  * This function returns %0 on success and a negative error code on failure.
367  */
write_cnodes(struct ubifs_info * c)368 static int write_cnodes(struct ubifs_info *c)
369 {
370 	int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
371 	struct ubifs_cnode *cnode;
372 	void *buf = c->lpt_buf;
373 
374 	cnode = c->lpt_cnext;
375 	if (!cnode)
376 		return 0;
377 	lnum = c->nhead_lnum;
378 	offs = c->nhead_offs;
379 	from = offs;
380 	/* Ensure empty LEB is unmapped */
381 	if (offs == 0) {
382 		err = ubifs_leb_unmap(c, lnum);
383 		if (err)
384 			return err;
385 	}
386 	/* Try to place lsave and ltab nicely */
387 	done_lsave = !c->big_lpt;
388 	done_ltab = 0;
389 	if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
390 		done_lsave = 1;
391 		ubifs_pack_lsave(c, buf + offs, c->lsave);
392 		offs += c->lsave_sz;
393 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
394 	}
395 
396 	if (offs + c->ltab_sz <= c->leb_size) {
397 		done_ltab = 1;
398 		ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
399 		offs += c->ltab_sz;
400 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
401 	}
402 
403 	/* Loop for each cnode */
404 	do {
405 		if (cnode->level)
406 			len = c->nnode_sz;
407 		else
408 			len = c->pnode_sz;
409 		while (offs + len > c->leb_size) {
410 			wlen = offs - from;
411 			if (wlen) {
412 				alen = ALIGN(wlen, c->min_io_size);
413 				memset(buf + offs, 0xff, alen - wlen);
414 				err = ubifs_leb_write(c, lnum, buf + from, from,
415 						       alen);
416 				if (err)
417 					return err;
418 			}
419 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
420 			err = realloc_lpt_leb(c, &lnum);
421 			if (err)
422 				goto no_space;
423 			offs = from = 0;
424 			ubifs_assert(lnum >= c->lpt_first &&
425 				     lnum <= c->lpt_last);
426 			err = ubifs_leb_unmap(c, lnum);
427 			if (err)
428 				return err;
429 			/* Try to place lsave and ltab nicely */
430 			if (!done_lsave) {
431 				done_lsave = 1;
432 				ubifs_pack_lsave(c, buf + offs, c->lsave);
433 				offs += c->lsave_sz;
434 				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
435 				continue;
436 			}
437 			if (!done_ltab) {
438 				done_ltab = 1;
439 				ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
440 				offs += c->ltab_sz;
441 				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
442 				continue;
443 			}
444 			break;
445 		}
446 		if (cnode->level)
447 			ubifs_pack_nnode(c, buf + offs,
448 					 (struct ubifs_nnode *)cnode);
449 		else
450 			ubifs_pack_pnode(c, buf + offs,
451 					 (struct ubifs_pnode *)cnode);
452 		/*
453 		 * The reason for the barriers is the same as in case of TNC.
454 		 * See comment in 'write_index()'. 'dirty_cow_nnode()' and
455 		 * 'dirty_cow_pnode()' are the functions for which this is
456 		 * important.
457 		 */
458 		clear_bit(DIRTY_CNODE, &cnode->flags);
459 		smp_mb__before_atomic();
460 		clear_bit(COW_CNODE, &cnode->flags);
461 		smp_mb__after_atomic();
462 		offs += len;
463 		dbg_chk_lpt_sz(c, 1, len);
464 		cnode = cnode->cnext;
465 	} while (cnode && cnode != c->lpt_cnext);
466 
467 	/* Make sure to place LPT's save table */
468 	if (!done_lsave) {
469 		if (offs + c->lsave_sz > c->leb_size) {
470 			wlen = offs - from;
471 			alen = ALIGN(wlen, c->min_io_size);
472 			memset(buf + offs, 0xff, alen - wlen);
473 			err = ubifs_leb_write(c, lnum, buf + from, from, alen);
474 			if (err)
475 				return err;
476 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
477 			err = realloc_lpt_leb(c, &lnum);
478 			if (err)
479 				goto no_space;
480 			offs = from = 0;
481 			ubifs_assert(lnum >= c->lpt_first &&
482 				     lnum <= c->lpt_last);
483 			err = ubifs_leb_unmap(c, lnum);
484 			if (err)
485 				return err;
486 		}
487 		done_lsave = 1;
488 		ubifs_pack_lsave(c, buf + offs, c->lsave);
489 		offs += c->lsave_sz;
490 		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
491 	}
492 
493 	/* Make sure to place LPT's own lprops table */
494 	if (!done_ltab) {
495 		if (offs + c->ltab_sz > c->leb_size) {
496 			wlen = offs - from;
497 			alen = ALIGN(wlen, c->min_io_size);
498 			memset(buf + offs, 0xff, alen - wlen);
499 			err = ubifs_leb_write(c, lnum, buf + from, from, alen);
500 			if (err)
501 				return err;
502 			dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
503 			err = realloc_lpt_leb(c, &lnum);
504 			if (err)
505 				goto no_space;
506 			offs = from = 0;
507 			ubifs_assert(lnum >= c->lpt_first &&
508 				     lnum <= c->lpt_last);
509 			err = ubifs_leb_unmap(c, lnum);
510 			if (err)
511 				return err;
512 		}
513 		ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
514 		offs += c->ltab_sz;
515 		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
516 	}
517 
518 	/* Write remaining data in buffer */
519 	wlen = offs - from;
520 	alen = ALIGN(wlen, c->min_io_size);
521 	memset(buf + offs, 0xff, alen - wlen);
522 	err = ubifs_leb_write(c, lnum, buf + from, from, alen);
523 	if (err)
524 		return err;
525 
526 	dbg_chk_lpt_sz(c, 4, alen - wlen);
527 	err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
528 	if (err)
529 		return err;
530 
531 	c->nhead_lnum = lnum;
532 	c->nhead_offs = ALIGN(offs, c->min_io_size);
533 
534 	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
535 	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
536 	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
537 	if (c->big_lpt)
538 		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
539 
540 	return 0;
541 
542 no_space:
543 	ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
544 		  lnum, offs, len, done_ltab, done_lsave);
545 	ubifs_dump_lpt_info(c);
546 	ubifs_dump_lpt_lebs(c);
547 	dump_stack();
548 	return err;
549 }
550 #endif
551 
552 /**
553  * next_pnode_to_dirty - find next pnode to dirty.
554  * @c: UBIFS file-system description object
555  * @pnode: pnode
556  *
557  * This function returns the next pnode to dirty or %NULL if there are no more
558  * pnodes.  Note that pnodes that have never been written (lnum == 0) are
559  * skipped.
560  */
next_pnode_to_dirty(struct ubifs_info * c,struct ubifs_pnode * pnode)561 static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
562 					       struct ubifs_pnode *pnode)
563 {
564 	struct ubifs_nnode *nnode;
565 	int iip;
566 
567 	/* Try to go right */
568 	nnode = pnode->parent;
569 	for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
570 		if (nnode->nbranch[iip].lnum)
571 			return ubifs_get_pnode(c, nnode, iip);
572 	}
573 
574 	/* Go up while can't go right */
575 	do {
576 		iip = nnode->iip + 1;
577 		nnode = nnode->parent;
578 		if (!nnode)
579 			return NULL;
580 		for (; iip < UBIFS_LPT_FANOUT; iip++) {
581 			if (nnode->nbranch[iip].lnum)
582 				break;
583 		}
584 	} while (iip >= UBIFS_LPT_FANOUT);
585 
586 	/* Go right */
587 	nnode = ubifs_get_nnode(c, nnode, iip);
588 	if (IS_ERR(nnode))
589 		return (void *)nnode;
590 
591 	/* Go down to level 1 */
592 	while (nnode->level > 1) {
593 		for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
594 			if (nnode->nbranch[iip].lnum)
595 				break;
596 		}
597 		if (iip >= UBIFS_LPT_FANOUT) {
598 			/*
599 			 * Should not happen, but we need to keep going
600 			 * if it does.
601 			 */
602 			iip = 0;
603 		}
604 		nnode = ubifs_get_nnode(c, nnode, iip);
605 		if (IS_ERR(nnode))
606 			return (void *)nnode;
607 	}
608 
609 	for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
610 		if (nnode->nbranch[iip].lnum)
611 			break;
612 	if (iip >= UBIFS_LPT_FANOUT)
613 		/* Should not happen, but we need to keep going if it does */
614 		iip = 0;
615 	return ubifs_get_pnode(c, nnode, iip);
616 }
617 
618 /**
619  * pnode_lookup - lookup a pnode in the LPT.
620  * @c: UBIFS file-system description object
621  * @i: pnode number (0 to main_lebs - 1)
622  *
623  * This function returns a pointer to the pnode on success or a negative
624  * error code on failure.
625  */
pnode_lookup(struct ubifs_info * c,int i)626 static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
627 {
628 	int err, h, iip, shft;
629 	struct ubifs_nnode *nnode;
630 
631 	if (!c->nroot) {
632 		err = ubifs_read_nnode(c, NULL, 0);
633 		if (err)
634 			return ERR_PTR(err);
635 	}
636 	i <<= UBIFS_LPT_FANOUT_SHIFT;
637 	nnode = c->nroot;
638 	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
639 	for (h = 1; h < c->lpt_hght; h++) {
640 		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
641 		shft -= UBIFS_LPT_FANOUT_SHIFT;
642 		nnode = ubifs_get_nnode(c, nnode, iip);
643 		if (IS_ERR(nnode))
644 			return ERR_CAST(nnode);
645 	}
646 	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
647 	return ubifs_get_pnode(c, nnode, iip);
648 }
649 
650 /**
651  * add_pnode_dirt - add dirty space to LPT LEB properties.
652  * @c: UBIFS file-system description object
653  * @pnode: pnode for which to add dirt
654  */
add_pnode_dirt(struct ubifs_info * c,struct ubifs_pnode * pnode)655 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
656 {
657 	ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
658 			   c->pnode_sz);
659 }
660 
661 /**
662  * do_make_pnode_dirty - mark a pnode dirty.
663  * @c: UBIFS file-system description object
664  * @pnode: pnode to mark dirty
665  */
do_make_pnode_dirty(struct ubifs_info * c,struct ubifs_pnode * pnode)666 static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
667 {
668 	/* Assumes cnext list is empty i.e. not called during commit */
669 	if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
670 		struct ubifs_nnode *nnode;
671 
672 		c->dirty_pn_cnt += 1;
673 		add_pnode_dirt(c, pnode);
674 		/* Mark parent and ancestors dirty too */
675 		nnode = pnode->parent;
676 		while (nnode) {
677 			if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
678 				c->dirty_nn_cnt += 1;
679 				ubifs_add_nnode_dirt(c, nnode);
680 				nnode = nnode->parent;
681 			} else
682 				break;
683 		}
684 	}
685 }
686 
687 /**
688  * make_tree_dirty - mark the entire LEB properties tree dirty.
689  * @c: UBIFS file-system description object
690  *
691  * This function is used by the "small" LPT model to cause the entire LEB
692  * properties tree to be written.  The "small" LPT model does not use LPT
693  * garbage collection because it is more efficient to write the entire tree
694  * (because it is small).
695  *
696  * This function returns %0 on success and a negative error code on failure.
697  */
make_tree_dirty(struct ubifs_info * c)698 static int make_tree_dirty(struct ubifs_info *c)
699 {
700 	struct ubifs_pnode *pnode;
701 
702 	pnode = pnode_lookup(c, 0);
703 	if (IS_ERR(pnode))
704 		return PTR_ERR(pnode);
705 
706 	while (pnode) {
707 		do_make_pnode_dirty(c, pnode);
708 		pnode = next_pnode_to_dirty(c, pnode);
709 		if (IS_ERR(pnode))
710 			return PTR_ERR(pnode);
711 	}
712 	return 0;
713 }
714 
715 /**
716  * need_write_all - determine if the LPT area is running out of free space.
717  * @c: UBIFS file-system description object
718  *
719  * This function returns %1 if the LPT area is running out of free space and %0
720  * if it is not.
721  */
need_write_all(struct ubifs_info * c)722 static int need_write_all(struct ubifs_info *c)
723 {
724 	long long free = 0;
725 	int i;
726 
727 	for (i = 0; i < c->lpt_lebs; i++) {
728 		if (i + c->lpt_first == c->nhead_lnum)
729 			free += c->leb_size - c->nhead_offs;
730 		else if (c->ltab[i].free == c->leb_size)
731 			free += c->leb_size;
732 		else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
733 			free += c->leb_size;
734 	}
735 	/* Less than twice the size left */
736 	if (free <= c->lpt_sz * 2)
737 		return 1;
738 	return 0;
739 }
740 
741 /**
742  * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
743  * @c: UBIFS file-system description object
744  *
745  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
746  * free space and so may be reused as soon as the next commit is completed.
747  * This function is called during start commit to mark LPT LEBs for trivial GC.
748  */
lpt_tgc_start(struct ubifs_info * c)749 static void lpt_tgc_start(struct ubifs_info *c)
750 {
751 	int i;
752 
753 	for (i = 0; i < c->lpt_lebs; i++) {
754 		if (i + c->lpt_first == c->nhead_lnum)
755 			continue;
756 		if (c->ltab[i].dirty > 0 &&
757 		    c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
758 			c->ltab[i].tgc = 1;
759 			c->ltab[i].free = c->leb_size;
760 			c->ltab[i].dirty = 0;
761 			dbg_lp("LEB %d", i + c->lpt_first);
762 		}
763 	}
764 }
765 
766 /**
767  * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
768  * @c: UBIFS file-system description object
769  *
770  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
771  * free space and so may be reused as soon as the next commit is completed.
772  * This function is called after the commit is completed (master node has been
773  * written) and un-maps LPT LEBs that were marked for trivial GC.
774  */
lpt_tgc_end(struct ubifs_info * c)775 static int lpt_tgc_end(struct ubifs_info *c)
776 {
777 	int i, err;
778 
779 	for (i = 0; i < c->lpt_lebs; i++)
780 		if (c->ltab[i].tgc) {
781 			err = ubifs_leb_unmap(c, i + c->lpt_first);
782 			if (err)
783 				return err;
784 			c->ltab[i].tgc = 0;
785 			dbg_lp("LEB %d", i + c->lpt_first);
786 		}
787 	return 0;
788 }
789 
790 /**
791  * populate_lsave - fill the lsave array with important LEB numbers.
792  * @c: the UBIFS file-system description object
793  *
794  * This function is only called for the "big" model. It records a small number
795  * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
796  * most important to least important): empty, freeable, freeable index, dirty
797  * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
798  * their pnodes into memory.  That will stop us from having to scan the LPT
799  * straight away. For the "small" model we assume that scanning the LPT is no
800  * big deal.
801  */
populate_lsave(struct ubifs_info * c)802 static void populate_lsave(struct ubifs_info *c)
803 {
804 	struct ubifs_lprops *lprops;
805 	struct ubifs_lpt_heap *heap;
806 	int i, cnt = 0;
807 
808 	ubifs_assert(c->big_lpt);
809 	if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
810 		c->lpt_drty_flgs |= LSAVE_DIRTY;
811 		ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
812 	}
813 
814 #ifndef __UBOOT__
815 	if (dbg_populate_lsave(c))
816 		return;
817 #endif
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  */
nnode_lookup(struct ubifs_info * c,int i)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  */
make_nnode_dirty(struct ubifs_info * c,int node_num,int lnum,int offs)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  */
make_pnode_dirty(struct ubifs_info * c,int node_num,int lnum,int offs)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  */
make_ltab_dirty(struct ubifs_info * c,int lnum,int offs)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  */
make_lsave_dirty(struct ubifs_info * c,int lnum,int offs)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  */
make_node_dirty(struct ubifs_info * c,int node_type,int node_num,int lnum,int offs)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  */
get_lpt_node_len(const struct ubifs_info * c,int node_type)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  */
get_pad_len(const struct ubifs_info * c,uint8_t * buf,int len)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  */
get_lpt_node_type(const struct ubifs_info * c,uint8_t * buf,int * node_num)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  */
is_a_node(const struct ubifs_info * c,uint8_t * buf,int len)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  */
lpt_gc_lnum(struct ubifs_info * c,int lnum)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  */
lpt_gc(struct ubifs_info * c)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  */
ubifs_lpt_start_commit(struct ubifs_info * c)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  */
free_obsolete_cnodes(struct ubifs_info * c)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 #ifndef __UBOOT__
1314 /**
1315  * ubifs_lpt_end_commit - finish the commit operation.
1316  * @c: the UBIFS file-system description object
1317  *
1318  * This function has to be called when the commit operation finishes. It
1319  * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1320  * the media. Returns zero in case of success and a negative error code in case
1321  * of failure.
1322  */
ubifs_lpt_end_commit(struct ubifs_info * c)1323 int ubifs_lpt_end_commit(struct ubifs_info *c)
1324 {
1325 	int err;
1326 
1327 	dbg_lp("");
1328 
1329 	if (!c->lpt_cnext)
1330 		return 0;
1331 
1332 	err = write_cnodes(c);
1333 	if (err)
1334 		return err;
1335 
1336 	mutex_lock(&c->lp_mutex);
1337 	free_obsolete_cnodes(c);
1338 	mutex_unlock(&c->lp_mutex);
1339 
1340 	return 0;
1341 }
1342 #endif
1343 
1344 /**
1345  * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1346  * @c: UBIFS file-system description object
1347  *
1348  * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1349  * commit for the "big" LPT model.
1350  */
ubifs_lpt_post_commit(struct ubifs_info * c)1351 int ubifs_lpt_post_commit(struct ubifs_info *c)
1352 {
1353 	int err;
1354 
1355 	mutex_lock(&c->lp_mutex);
1356 	err = lpt_tgc_end(c);
1357 	if (err)
1358 		goto out;
1359 	if (c->big_lpt)
1360 		while (need_write_all(c)) {
1361 			mutex_unlock(&c->lp_mutex);
1362 			err = lpt_gc(c);
1363 			if (err)
1364 				return err;
1365 			mutex_lock(&c->lp_mutex);
1366 		}
1367 out:
1368 	mutex_unlock(&c->lp_mutex);
1369 	return err;
1370 }
1371 
1372 /**
1373  * first_nnode - find the first nnode in memory.
1374  * @c: UBIFS file-system description object
1375  * @hght: height of tree where nnode found is returned here
1376  *
1377  * This function returns a pointer to the nnode found or %NULL if no nnode is
1378  * found. This function is a helper to 'ubifs_lpt_free()'.
1379  */
first_nnode(struct ubifs_info * c,int * hght)1380 static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1381 {
1382 	struct ubifs_nnode *nnode;
1383 	int h, i, found;
1384 
1385 	nnode = c->nroot;
1386 	*hght = 0;
1387 	if (!nnode)
1388 		return NULL;
1389 	for (h = 1; h < c->lpt_hght; h++) {
1390 		found = 0;
1391 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1392 			if (nnode->nbranch[i].nnode) {
1393 				found = 1;
1394 				nnode = nnode->nbranch[i].nnode;
1395 				*hght = h;
1396 				break;
1397 			}
1398 		}
1399 		if (!found)
1400 			break;
1401 	}
1402 	return nnode;
1403 }
1404 
1405 /**
1406  * next_nnode - find the next nnode in memory.
1407  * @c: UBIFS file-system description object
1408  * @nnode: nnode from which to start.
1409  * @hght: height of tree where nnode is, is passed and returned here
1410  *
1411  * This function returns a pointer to the nnode found or %NULL if no nnode is
1412  * found. This function is a helper to 'ubifs_lpt_free()'.
1413  */
next_nnode(struct ubifs_info * c,struct ubifs_nnode * nnode,int * hght)1414 static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1415 				      struct ubifs_nnode *nnode, int *hght)
1416 {
1417 	struct ubifs_nnode *parent;
1418 	int iip, h, i, found;
1419 
1420 	parent = nnode->parent;
1421 	if (!parent)
1422 		return NULL;
1423 	if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1424 		*hght -= 1;
1425 		return parent;
1426 	}
1427 	for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1428 		nnode = parent->nbranch[iip].nnode;
1429 		if (nnode)
1430 			break;
1431 	}
1432 	if (!nnode) {
1433 		*hght -= 1;
1434 		return parent;
1435 	}
1436 	for (h = *hght + 1; h < c->lpt_hght; h++) {
1437 		found = 0;
1438 		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1439 			if (nnode->nbranch[i].nnode) {
1440 				found = 1;
1441 				nnode = nnode->nbranch[i].nnode;
1442 				*hght = h;
1443 				break;
1444 			}
1445 		}
1446 		if (!found)
1447 			break;
1448 	}
1449 	return nnode;
1450 }
1451 
1452 /**
1453  * ubifs_lpt_free - free resources owned by the LPT.
1454  * @c: UBIFS file-system description object
1455  * @wr_only: free only resources used for writing
1456  */
ubifs_lpt_free(struct ubifs_info * c,int wr_only)1457 void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1458 {
1459 	struct ubifs_nnode *nnode;
1460 	int i, hght;
1461 
1462 	/* Free write-only things first */
1463 
1464 	free_obsolete_cnodes(c); /* Leftover from a failed commit */
1465 
1466 	vfree(c->ltab_cmt);
1467 	c->ltab_cmt = NULL;
1468 	vfree(c->lpt_buf);
1469 	c->lpt_buf = NULL;
1470 	kfree(c->lsave);
1471 	c->lsave = NULL;
1472 
1473 	if (wr_only)
1474 		return;
1475 
1476 	/* Now free the rest */
1477 
1478 	nnode = first_nnode(c, &hght);
1479 	while (nnode) {
1480 		for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1481 			kfree(nnode->nbranch[i].nnode);
1482 		nnode = next_nnode(c, nnode, &hght);
1483 	}
1484 	for (i = 0; i < LPROPS_HEAP_CNT; i++)
1485 		kfree(c->lpt_heap[i].arr);
1486 	kfree(c->dirty_idx.arr);
1487 	kfree(c->nroot);
1488 	vfree(c->ltab);
1489 	kfree(c->lpt_nod_buf);
1490 }
1491 
1492 #ifndef __UBOOT__
1493 /*
1494  * Everything below is related to debugging.
1495  */
1496 
1497 /**
1498  * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1499  * @buf: buffer
1500  * @len: buffer length
1501  */
dbg_is_all_ff(uint8_t * buf,int len)1502 static int dbg_is_all_ff(uint8_t *buf, int len)
1503 {
1504 	int i;
1505 
1506 	for (i = 0; i < len; i++)
1507 		if (buf[i] != 0xff)
1508 			return 0;
1509 	return 1;
1510 }
1511 
1512 /**
1513  * dbg_is_nnode_dirty - determine if a nnode is dirty.
1514  * @c: the UBIFS file-system description object
1515  * @lnum: LEB number where nnode was written
1516  * @offs: offset where nnode was written
1517  */
dbg_is_nnode_dirty(struct ubifs_info * c,int lnum,int offs)1518 static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1519 {
1520 	struct ubifs_nnode *nnode;
1521 	int hght;
1522 
1523 	/* Entire tree is in memory so first_nnode / next_nnode are OK */
1524 	nnode = first_nnode(c, &hght);
1525 	for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1526 		struct ubifs_nbranch *branch;
1527 
1528 		cond_resched();
1529 		if (nnode->parent) {
1530 			branch = &nnode->parent->nbranch[nnode->iip];
1531 			if (branch->lnum != lnum || branch->offs != offs)
1532 				continue;
1533 			if (test_bit(DIRTY_CNODE, &nnode->flags))
1534 				return 1;
1535 			return 0;
1536 		} else {
1537 			if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1538 				continue;
1539 			if (test_bit(DIRTY_CNODE, &nnode->flags))
1540 				return 1;
1541 			return 0;
1542 		}
1543 	}
1544 	return 1;
1545 }
1546 
1547 /**
1548  * dbg_is_pnode_dirty - determine if a pnode is dirty.
1549  * @c: the UBIFS file-system description object
1550  * @lnum: LEB number where pnode was written
1551  * @offs: offset where pnode was written
1552  */
dbg_is_pnode_dirty(struct ubifs_info * c,int lnum,int offs)1553 static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1554 {
1555 	int i, cnt;
1556 
1557 	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1558 	for (i = 0; i < cnt; i++) {
1559 		struct ubifs_pnode *pnode;
1560 		struct ubifs_nbranch *branch;
1561 
1562 		cond_resched();
1563 		pnode = pnode_lookup(c, i);
1564 		if (IS_ERR(pnode))
1565 			return PTR_ERR(pnode);
1566 		branch = &pnode->parent->nbranch[pnode->iip];
1567 		if (branch->lnum != lnum || branch->offs != offs)
1568 			continue;
1569 		if (test_bit(DIRTY_CNODE, &pnode->flags))
1570 			return 1;
1571 		return 0;
1572 	}
1573 	return 1;
1574 }
1575 
1576 /**
1577  * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1578  * @c: the UBIFS file-system description object
1579  * @lnum: LEB number where ltab node was written
1580  * @offs: offset where ltab node was written
1581  */
dbg_is_ltab_dirty(struct ubifs_info * c,int lnum,int offs)1582 static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1583 {
1584 	if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1585 		return 1;
1586 	return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1587 }
1588 
1589 /**
1590  * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1591  * @c: the UBIFS file-system description object
1592  * @lnum: LEB number where lsave node was written
1593  * @offs: offset where lsave node was written
1594  */
dbg_is_lsave_dirty(struct ubifs_info * c,int lnum,int offs)1595 static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1596 {
1597 	if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1598 		return 1;
1599 	return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1600 }
1601 
1602 /**
1603  * dbg_is_node_dirty - determine if a node is dirty.
1604  * @c: the UBIFS file-system description object
1605  * @node_type: node type
1606  * @lnum: LEB number where node was written
1607  * @offs: offset where node was written
1608  */
dbg_is_node_dirty(struct ubifs_info * c,int node_type,int lnum,int offs)1609 static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1610 			     int offs)
1611 {
1612 	switch (node_type) {
1613 	case UBIFS_LPT_NNODE:
1614 		return dbg_is_nnode_dirty(c, lnum, offs);
1615 	case UBIFS_LPT_PNODE:
1616 		return dbg_is_pnode_dirty(c, lnum, offs);
1617 	case UBIFS_LPT_LTAB:
1618 		return dbg_is_ltab_dirty(c, lnum, offs);
1619 	case UBIFS_LPT_LSAVE:
1620 		return dbg_is_lsave_dirty(c, lnum, offs);
1621 	}
1622 	return 1;
1623 }
1624 
1625 /**
1626  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1627  * @c: the UBIFS file-system description object
1628  * @lnum: LEB number where node was written
1629  * @offs: offset where node was written
1630  *
1631  * This function returns %0 on success and a negative error code on failure.
1632  */
dbg_check_ltab_lnum(struct ubifs_info * c,int lnum)1633 static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1634 {
1635 	int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1636 	int ret;
1637 	void *buf, *p;
1638 
1639 	if (!dbg_is_chk_lprops(c))
1640 		return 0;
1641 
1642 	buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1643 	if (!buf) {
1644 		ubifs_err(c, "cannot allocate memory for ltab checking");
1645 		return 0;
1646 	}
1647 
1648 	dbg_lp("LEB %d", lnum);
1649 
1650 	err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1651 	if (err)
1652 		goto out;
1653 
1654 	while (1) {
1655 		if (!is_a_node(c, p, len)) {
1656 			int i, pad_len;
1657 
1658 			pad_len = get_pad_len(c, p, len);
1659 			if (pad_len) {
1660 				p += pad_len;
1661 				len -= pad_len;
1662 				dirty += pad_len;
1663 				continue;
1664 			}
1665 			if (!dbg_is_all_ff(p, len)) {
1666 				ubifs_err(c, "invalid empty space in LEB %d at %d",
1667 					  lnum, c->leb_size - len);
1668 				err = -EINVAL;
1669 			}
1670 			i = lnum - c->lpt_first;
1671 			if (len != c->ltab[i].free) {
1672 				ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)",
1673 					  lnum, len, c->ltab[i].free);
1674 				err = -EINVAL;
1675 			}
1676 			if (dirty != c->ltab[i].dirty) {
1677 				ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)",
1678 					  lnum, dirty, c->ltab[i].dirty);
1679 				err = -EINVAL;
1680 			}
1681 			goto out;
1682 		}
1683 		node_type = get_lpt_node_type(c, p, &node_num);
1684 		node_len = get_lpt_node_len(c, node_type);
1685 		ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1686 		if (ret == 1)
1687 			dirty += node_len;
1688 		p += node_len;
1689 		len -= node_len;
1690 	}
1691 
1692 	err = 0;
1693 out:
1694 	vfree(buf);
1695 	return err;
1696 }
1697 
1698 /**
1699  * dbg_check_ltab - check the free and dirty space in the ltab.
1700  * @c: the UBIFS file-system description object
1701  *
1702  * This function returns %0 on success and a negative error code on failure.
1703  */
dbg_check_ltab(struct ubifs_info * c)1704 int dbg_check_ltab(struct ubifs_info *c)
1705 {
1706 	int lnum, err, i, cnt;
1707 
1708 	if (!dbg_is_chk_lprops(c))
1709 		return 0;
1710 
1711 	/* Bring the entire tree into memory */
1712 	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1713 	for (i = 0; i < cnt; i++) {
1714 		struct ubifs_pnode *pnode;
1715 
1716 		pnode = pnode_lookup(c, i);
1717 		if (IS_ERR(pnode))
1718 			return PTR_ERR(pnode);
1719 		cond_resched();
1720 	}
1721 
1722 	/* Check nodes */
1723 	err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1724 	if (err)
1725 		return err;
1726 
1727 	/* Check each LEB */
1728 	for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1729 		err = dbg_check_ltab_lnum(c, lnum);
1730 		if (err) {
1731 			ubifs_err(c, "failed at LEB %d", lnum);
1732 			return err;
1733 		}
1734 	}
1735 
1736 	dbg_lp("succeeded");
1737 	return 0;
1738 }
1739 
1740 /**
1741  * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1742  * @c: the UBIFS file-system description object
1743  *
1744  * This function returns %0 on success and a negative error code on failure.
1745  */
dbg_chk_lpt_free_spc(struct ubifs_info * c)1746 int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1747 {
1748 	long long free = 0;
1749 	int i;
1750 
1751 	if (!dbg_is_chk_lprops(c))
1752 		return 0;
1753 
1754 	for (i = 0; i < c->lpt_lebs; i++) {
1755 		if (c->ltab[i].tgc || c->ltab[i].cmt)
1756 			continue;
1757 		if (i + c->lpt_first == c->nhead_lnum)
1758 			free += c->leb_size - c->nhead_offs;
1759 		else if (c->ltab[i].free == c->leb_size)
1760 			free += c->leb_size;
1761 	}
1762 	if (free < c->lpt_sz) {
1763 		ubifs_err(c, "LPT space error: free %lld lpt_sz %lld",
1764 			  free, c->lpt_sz);
1765 		ubifs_dump_lpt_info(c);
1766 		ubifs_dump_lpt_lebs(c);
1767 		dump_stack();
1768 		return -EINVAL;
1769 	}
1770 	return 0;
1771 }
1772 
1773 /**
1774  * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1775  * @c: the UBIFS file-system description object
1776  * @action: what to do
1777  * @len: length written
1778  *
1779  * This function returns %0 on success and a negative error code on failure.
1780  * The @action argument may be one of:
1781  *   o %0 - LPT debugging checking starts, initialize debugging variables;
1782  *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1783  *   o %2 - switched to a different LEB and wasted @len bytes;
1784  *   o %3 - check that we've written the right number of bytes.
1785  *   o %4 - wasted @len bytes;
1786  */
dbg_chk_lpt_sz(struct ubifs_info * c,int action,int len)1787 int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1788 {
1789 	struct ubifs_debug_info *d = c->dbg;
1790 	long long chk_lpt_sz, lpt_sz;
1791 	int err = 0;
1792 
1793 	if (!dbg_is_chk_lprops(c))
1794 		return 0;
1795 
1796 	switch (action) {
1797 	case 0:
1798 		d->chk_lpt_sz = 0;
1799 		d->chk_lpt_sz2 = 0;
1800 		d->chk_lpt_lebs = 0;
1801 		d->chk_lpt_wastage = 0;
1802 		if (c->dirty_pn_cnt > c->pnode_cnt) {
1803 			ubifs_err(c, "dirty pnodes %d exceed max %d",
1804 				  c->dirty_pn_cnt, c->pnode_cnt);
1805 			err = -EINVAL;
1806 		}
1807 		if (c->dirty_nn_cnt > c->nnode_cnt) {
1808 			ubifs_err(c, "dirty nnodes %d exceed max %d",
1809 				  c->dirty_nn_cnt, c->nnode_cnt);
1810 			err = -EINVAL;
1811 		}
1812 		return err;
1813 	case 1:
1814 		d->chk_lpt_sz += len;
1815 		return 0;
1816 	case 2:
1817 		d->chk_lpt_sz += len;
1818 		d->chk_lpt_wastage += len;
1819 		d->chk_lpt_lebs += 1;
1820 		return 0;
1821 	case 3:
1822 		chk_lpt_sz = c->leb_size;
1823 		chk_lpt_sz *= d->chk_lpt_lebs;
1824 		chk_lpt_sz += len - c->nhead_offs;
1825 		if (d->chk_lpt_sz != chk_lpt_sz) {
1826 			ubifs_err(c, "LPT wrote %lld but space used was %lld",
1827 				  d->chk_lpt_sz, chk_lpt_sz);
1828 			err = -EINVAL;
1829 		}
1830 		if (d->chk_lpt_sz > c->lpt_sz) {
1831 			ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld",
1832 				  d->chk_lpt_sz, c->lpt_sz);
1833 			err = -EINVAL;
1834 		}
1835 		if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1836 			ubifs_err(c, "LPT layout size %lld but wrote %lld",
1837 				  d->chk_lpt_sz, d->chk_lpt_sz2);
1838 			err = -EINVAL;
1839 		}
1840 		if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1841 			ubifs_err(c, "LPT new nhead offs: expected %d was %d",
1842 				  d->new_nhead_offs, len);
1843 			err = -EINVAL;
1844 		}
1845 		lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1846 		lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1847 		lpt_sz += c->ltab_sz;
1848 		if (c->big_lpt)
1849 			lpt_sz += c->lsave_sz;
1850 		if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1851 			ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1852 				  d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1853 			err = -EINVAL;
1854 		}
1855 		if (err) {
1856 			ubifs_dump_lpt_info(c);
1857 			ubifs_dump_lpt_lebs(c);
1858 			dump_stack();
1859 		}
1860 		d->chk_lpt_sz2 = d->chk_lpt_sz;
1861 		d->chk_lpt_sz = 0;
1862 		d->chk_lpt_wastage = 0;
1863 		d->chk_lpt_lebs = 0;
1864 		d->new_nhead_offs = len;
1865 		return err;
1866 	case 4:
1867 		d->chk_lpt_sz += len;
1868 		d->chk_lpt_wastage += len;
1869 		return 0;
1870 	default:
1871 		return -EINVAL;
1872 	}
1873 }
1874 
1875 /**
1876  * ubifs_dump_lpt_leb - dump an LPT LEB.
1877  * @c: UBIFS file-system description object
1878  * @lnum: LEB number to dump
1879  *
1880  * This function dumps an LEB from LPT area. Nodes in this area are very
1881  * different to nodes in the main area (e.g., they do not have common headers,
1882  * they do not have 8-byte alignments, etc), so we have a separate function to
1883  * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1884  */
dump_lpt_leb(const struct ubifs_info * c,int lnum)1885 static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1886 {
1887 	int err, len = c->leb_size, node_type, node_num, node_len, offs;
1888 	void *buf, *p;
1889 
1890 	pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
1891 	buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1892 	if (!buf) {
1893 		ubifs_err(c, "cannot allocate memory to dump LPT");
1894 		return;
1895 	}
1896 
1897 	err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1898 	if (err)
1899 		goto out;
1900 
1901 	while (1) {
1902 		offs = c->leb_size - len;
1903 		if (!is_a_node(c, p, len)) {
1904 			int pad_len;
1905 
1906 			pad_len = get_pad_len(c, p, len);
1907 			if (pad_len) {
1908 				pr_err("LEB %d:%d, pad %d bytes\n",
1909 				       lnum, offs, pad_len);
1910 				p += pad_len;
1911 				len -= pad_len;
1912 				continue;
1913 			}
1914 			if (len)
1915 				pr_err("LEB %d:%d, free %d bytes\n",
1916 				       lnum, offs, len);
1917 			break;
1918 		}
1919 
1920 		node_type = get_lpt_node_type(c, p, &node_num);
1921 		switch (node_type) {
1922 		case UBIFS_LPT_PNODE:
1923 		{
1924 			node_len = c->pnode_sz;
1925 			if (c->big_lpt)
1926 				pr_err("LEB %d:%d, pnode num %d\n",
1927 				       lnum, offs, node_num);
1928 			else
1929 				pr_err("LEB %d:%d, pnode\n", lnum, offs);
1930 			break;
1931 		}
1932 		case UBIFS_LPT_NNODE:
1933 		{
1934 			int i;
1935 			struct ubifs_nnode nnode;
1936 
1937 			node_len = c->nnode_sz;
1938 			if (c->big_lpt)
1939 				pr_err("LEB %d:%d, nnode num %d, ",
1940 				       lnum, offs, node_num);
1941 			else
1942 				pr_err("LEB %d:%d, nnode, ",
1943 				       lnum, offs);
1944 			err = ubifs_unpack_nnode(c, p, &nnode);
1945 			if (err) {
1946 				pr_err("failed to unpack_node, error %d\n",
1947 				       err);
1948 				break;
1949 			}
1950 			for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1951 				pr_cont("%d:%d", nnode.nbranch[i].lnum,
1952 				       nnode.nbranch[i].offs);
1953 				if (i != UBIFS_LPT_FANOUT - 1)
1954 					pr_cont(", ");
1955 			}
1956 			pr_cont("\n");
1957 			break;
1958 		}
1959 		case UBIFS_LPT_LTAB:
1960 			node_len = c->ltab_sz;
1961 			pr_err("LEB %d:%d, ltab\n", lnum, offs);
1962 			break;
1963 		case UBIFS_LPT_LSAVE:
1964 			node_len = c->lsave_sz;
1965 			pr_err("LEB %d:%d, lsave len\n", lnum, offs);
1966 			break;
1967 		default:
1968 			ubifs_err(c, "LPT node type %d not recognized", node_type);
1969 			goto out;
1970 		}
1971 
1972 		p += node_len;
1973 		len -= node_len;
1974 	}
1975 
1976 	pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
1977 out:
1978 	vfree(buf);
1979 	return;
1980 }
1981 
1982 /**
1983  * ubifs_dump_lpt_lebs - dump LPT lebs.
1984  * @c: UBIFS file-system description object
1985  *
1986  * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1987  * locked.
1988  */
ubifs_dump_lpt_lebs(const struct ubifs_info * c)1989 void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
1990 {
1991 	int i;
1992 
1993 	pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid);
1994 	for (i = 0; i < c->lpt_lebs; i++)
1995 		dump_lpt_leb(c, i + c->lpt_first);
1996 	pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid);
1997 }
1998 
1999 /**
2000  * dbg_populate_lsave - debugging version of 'populate_lsave()'
2001  * @c: UBIFS file-system description object
2002  *
2003  * This is a debugging version for 'populate_lsave()' which populates lsave
2004  * with random LEBs instead of useful LEBs, which is good for test coverage.
2005  * Returns zero if lsave has not been populated (this debugging feature is
2006  * disabled) an non-zero if lsave has been populated.
2007  */
dbg_populate_lsave(struct ubifs_info * c)2008 static int dbg_populate_lsave(struct ubifs_info *c)
2009 {
2010 	struct ubifs_lprops *lprops;
2011 	struct ubifs_lpt_heap *heap;
2012 	int i;
2013 
2014 	if (!dbg_is_chk_gen(c))
2015 		return 0;
2016 	if (prandom_u32() & 3)
2017 		return 0;
2018 
2019 	for (i = 0; i < c->lsave_cnt; i++)
2020 		c->lsave[i] = c->main_first;
2021 
2022 	list_for_each_entry(lprops, &c->empty_list, list)
2023 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2024 	list_for_each_entry(lprops, &c->freeable_list, list)
2025 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2026 	list_for_each_entry(lprops, &c->frdi_idx_list, list)
2027 		c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
2028 
2029 	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 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_DIRTY - 1];
2033 	for (i = 0; i < heap->cnt; i++)
2034 		c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2035 	heap = &c->lpt_heap[LPROPS_FREE - 1];
2036 	for (i = 0; i < heap->cnt; i++)
2037 		c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
2038 
2039 	return 1;
2040 }
2041 #endif
2042