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 (���������������� ����������)
9 */
10
11/*
12 * This file implements the LEB properties tree (LPT) area. The LPT area
13 * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
14 * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
15 * between the log and the orphan area.
16 *
17 * The LPT area is like a miniature self-contained file system. It is required
18 * that it never runs out of space, is fast to access and update, and scales
19 * logarithmically. The LEB properties tree is implemented as a wandering tree
20 * much like the TNC, and the LPT area has its own garbage collection.
21 *
22 * The LPT has two slightly different forms called the "small model" and the
23 * "big model". The small model is used when the entire LEB properties table
24 * can be written into a single eraseblock. In that case, garbage collection
25 * consists of just writing the whole table, which therefore makes all other
26 * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
27 * selected for garbage collection, which consists of marking the clean nodes in
28 * that LEB as dirty, and then only the dirty nodes are written out. Also, in
29 * the case of the big model, a table of LEB numbers is saved so that the entire
30 * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
31 * mounted.
32 */
33
34#include "ubifs.h"
35#ifndef __UBOOT__
36#include <log.h>
37#include <dm/devres.h>
38#include <linux/crc16.h>
39#include <linux/math64.h>
40#include <linux/slab.h>
41#else
42#include <linux/compat.h>
43#include <linux/err.h>
44#include <ubi_uboot.h>
45#include <linux/crc16.h>
46#endif
47
48/**
49 * do_calc_lpt_geom - calculate sizes for the LPT area.
50 * @c: the UBIFS file-system description object
51 *
52 * Calculate the sizes of LPT bit fields, nodes, and tree, based on the
53 * properties of the flash and whether LPT is "big" (c->big_lpt).
54 */
55static void do_calc_lpt_geom(struct ubifs_info *c)
56{
57	int i, n, bits, per_leb_wastage, max_pnode_cnt;
58	long long sz, tot_wastage;
59
60	n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
61	max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
62
63	c->lpt_hght = 1;
64	n = UBIFS_LPT_FANOUT;
65	while (n < max_pnode_cnt) {
66		c->lpt_hght += 1;
67		n <<= UBIFS_LPT_FANOUT_SHIFT;
68	}
69
70	c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
71
72	n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
73	c->nnode_cnt = n;
74	for (i = 1; i < c->lpt_hght; i++) {
75		n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
76		c->nnode_cnt += n;
77	}
78
79	c->space_bits = fls(c->leb_size) - 3;
80	c->lpt_lnum_bits = fls(c->lpt_lebs);
81	c->lpt_offs_bits = fls(c->leb_size - 1);
82	c->lpt_spc_bits = fls(c->leb_size);
83
84	n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
85	c->pcnt_bits = fls(n - 1);
86
87	c->lnum_bits = fls(c->max_leb_cnt - 1);
88
89	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
90	       (c->big_lpt ? c->pcnt_bits : 0) +
91	       (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
92	c->pnode_sz = (bits + 7) / 8;
93
94	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
95	       (c->big_lpt ? c->pcnt_bits : 0) +
96	       (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
97	c->nnode_sz = (bits + 7) / 8;
98
99	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
100	       c->lpt_lebs * c->lpt_spc_bits * 2;
101	c->ltab_sz = (bits + 7) / 8;
102
103	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
104	       c->lnum_bits * c->lsave_cnt;
105	c->lsave_sz = (bits + 7) / 8;
106
107	/* Calculate the minimum LPT size */
108	c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
109	c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
110	c->lpt_sz += c->ltab_sz;
111	if (c->big_lpt)
112		c->lpt_sz += c->lsave_sz;
113
114	/* Add wastage */
115	sz = c->lpt_sz;
116	per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
117	sz += per_leb_wastage;
118	tot_wastage = per_leb_wastage;
119	while (sz > c->leb_size) {
120		sz += per_leb_wastage;
121		sz -= c->leb_size;
122		tot_wastage += per_leb_wastage;
123	}
124	tot_wastage += ALIGN(sz, c->min_io_size) - sz;
125	c->lpt_sz += tot_wastage;
126}
127
128/**
129 * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
130 * @c: the UBIFS file-system description object
131 *
132 * This function returns %0 on success and a negative error code on failure.
133 */
134int ubifs_calc_lpt_geom(struct ubifs_info *c)
135{
136	int lebs_needed;
137	long long sz;
138
139	do_calc_lpt_geom(c);
140
141	/* Verify that lpt_lebs is big enough */
142	sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
143	lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
144	if (lebs_needed > c->lpt_lebs) {
145		ubifs_err(c, "too few LPT LEBs");
146		return -EINVAL;
147	}
148
149	/* Verify that ltab fits in a single LEB (since ltab is a single node */
150	if (c->ltab_sz > c->leb_size) {
151		ubifs_err(c, "LPT ltab too big");
152		return -EINVAL;
153	}
154
155	c->check_lpt_free = c->big_lpt;
156	return 0;
157}
158
159/**
160 * calc_dflt_lpt_geom - calculate default LPT geometry.
161 * @c: the UBIFS file-system description object
162 * @main_lebs: number of main area LEBs is passed and returned here
163 * @big_lpt: whether the LPT area is "big" is returned here
164 *
165 * The size of the LPT area depends on parameters that themselves are dependent
166 * on the size of the LPT area. This function, successively recalculates the LPT
167 * area geometry until the parameters and resultant geometry are consistent.
168 *
169 * This function returns %0 on success and a negative error code on failure.
170 */
171static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
172			      int *big_lpt)
173{
174	int i, lebs_needed;
175	long long sz;
176
177	/* Start by assuming the minimum number of LPT LEBs */
178	c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
179	c->main_lebs = *main_lebs - c->lpt_lebs;
180	if (c->main_lebs <= 0)
181		return -EINVAL;
182
183	/* And assume we will use the small LPT model */
184	c->big_lpt = 0;
185
186	/*
187	 * Calculate the geometry based on assumptions above and then see if it
188	 * makes sense
189	 */
190	do_calc_lpt_geom(c);
191
192	/* Small LPT model must have lpt_sz < leb_size */
193	if (c->lpt_sz > c->leb_size) {
194		/* Nope, so try again using big LPT model */
195		c->big_lpt = 1;
196		do_calc_lpt_geom(c);
197	}
198
199	/* Now check there are enough LPT LEBs */
200	for (i = 0; i < 64 ; i++) {
201		sz = c->lpt_sz * 4; /* Allow 4 times the size */
202		lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
203		if (lebs_needed > c->lpt_lebs) {
204			/* Not enough LPT LEBs so try again with more */
205			c->lpt_lebs = lebs_needed;
206			c->main_lebs = *main_lebs - c->lpt_lebs;
207			if (c->main_lebs <= 0)
208				return -EINVAL;
209			do_calc_lpt_geom(c);
210			continue;
211		}
212		if (c->ltab_sz > c->leb_size) {
213			ubifs_err(c, "LPT ltab too big");
214			return -EINVAL;
215		}
216		*main_lebs = c->main_lebs;
217		*big_lpt = c->big_lpt;
218		return 0;
219	}
220	return -EINVAL;
221}
222
223/**
224 * pack_bits - pack bit fields end-to-end.
225 * @addr: address at which to pack (passed and next address returned)
226 * @pos: bit position at which to pack (passed and next position returned)
227 * @val: value to pack
228 * @nrbits: number of bits of value to pack (1-32)
229 */
230static void pack_bits(uint8_t **addr, int *pos, uint32_t val, int nrbits)
231{
232	uint8_t *p = *addr;
233	int b = *pos;
234
235	ubifs_assert(nrbits > 0);
236	ubifs_assert(nrbits <= 32);
237	ubifs_assert(*pos >= 0);
238	ubifs_assert(*pos < 8);
239	ubifs_assert((val >> nrbits) == 0 || nrbits == 32);
240	if (b) {
241		*p |= ((uint8_t)val) << b;
242		nrbits += b;
243		if (nrbits > 8) {
244			*++p = (uint8_t)(val >>= (8 - b));
245			if (nrbits > 16) {
246				*++p = (uint8_t)(val >>= 8);
247				if (nrbits > 24) {
248					*++p = (uint8_t)(val >>= 8);
249					if (nrbits > 32)
250						*++p = (uint8_t)(val >>= 8);
251				}
252			}
253		}
254	} else {
255		*p = (uint8_t)val;
256		if (nrbits > 8) {
257			*++p = (uint8_t)(val >>= 8);
258			if (nrbits > 16) {
259				*++p = (uint8_t)(val >>= 8);
260				if (nrbits > 24)
261					*++p = (uint8_t)(val >>= 8);
262			}
263		}
264	}
265	b = nrbits & 7;
266	if (b == 0)
267		p++;
268	*addr = p;
269	*pos = b;
270}
271
272/**
273 * ubifs_unpack_bits - unpack bit fields.
274 * @addr: address at which to unpack (passed and next address returned)
275 * @pos: bit position at which to unpack (passed and next position returned)
276 * @nrbits: number of bits of value to unpack (1-32)
277 *
278 * This functions returns the value unpacked.
279 */
280uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
281{
282	const int k = 32 - nrbits;
283	uint8_t *p = *addr;
284	int b = *pos;
285	uint32_t uninitialized_var(val);
286	const int bytes = (nrbits + b + 7) >> 3;
287
288	ubifs_assert(nrbits > 0);
289	ubifs_assert(nrbits <= 32);
290	ubifs_assert(*pos >= 0);
291	ubifs_assert(*pos < 8);
292	if (b) {
293		switch (bytes) {
294		case 2:
295			val = p[1];
296			break;
297		case 3:
298			val = p[1] | ((uint32_t)p[2] << 8);
299			break;
300		case 4:
301			val = p[1] | ((uint32_t)p[2] << 8) |
302				     ((uint32_t)p[3] << 16);
303			break;
304		case 5:
305			val = p[1] | ((uint32_t)p[2] << 8) |
306				     ((uint32_t)p[3] << 16) |
307				     ((uint32_t)p[4] << 24);
308		}
309		val <<= (8 - b);
310		val |= *p >> b;
311		nrbits += b;
312	} else {
313		switch (bytes) {
314		case 1:
315			val = p[0];
316			break;
317		case 2:
318			val = p[0] | ((uint32_t)p[1] << 8);
319			break;
320		case 3:
321			val = p[0] | ((uint32_t)p[1] << 8) |
322				     ((uint32_t)p[2] << 16);
323			break;
324		case 4:
325			val = p[0] | ((uint32_t)p[1] << 8) |
326				     ((uint32_t)p[2] << 16) |
327				     ((uint32_t)p[3] << 24);
328			break;
329		}
330	}
331	val <<= k;
332	val >>= k;
333	b = nrbits & 7;
334	p += nrbits >> 3;
335	*addr = p;
336	*pos = b;
337	ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
338	return val;
339}
340
341/**
342 * ubifs_pack_pnode - pack all the bit fields of a pnode.
343 * @c: UBIFS file-system description object
344 * @buf: buffer into which to pack
345 * @pnode: pnode to pack
346 */
347void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
348		      struct ubifs_pnode *pnode)
349{
350	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
351	int i, pos = 0;
352	uint16_t crc;
353
354	pack_bits(&addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
355	if (c->big_lpt)
356		pack_bits(&addr, &pos, pnode->num, c->pcnt_bits);
357	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
358		pack_bits(&addr, &pos, pnode->lprops[i].free >> 3,
359			  c->space_bits);
360		pack_bits(&addr, &pos, pnode->lprops[i].dirty >> 3,
361			  c->space_bits);
362		if (pnode->lprops[i].flags & LPROPS_INDEX)
363			pack_bits(&addr, &pos, 1, 1);
364		else
365			pack_bits(&addr, &pos, 0, 1);
366	}
367	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
368		    c->pnode_sz - UBIFS_LPT_CRC_BYTES);
369	addr = buf;
370	pos = 0;
371	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
372}
373
374/**
375 * ubifs_pack_nnode - pack all the bit fields of a nnode.
376 * @c: UBIFS file-system description object
377 * @buf: buffer into which to pack
378 * @nnode: nnode to pack
379 */
380void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
381		      struct ubifs_nnode *nnode)
382{
383	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
384	int i, pos = 0;
385	uint16_t crc;
386
387	pack_bits(&addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
388	if (c->big_lpt)
389		pack_bits(&addr, &pos, nnode->num, c->pcnt_bits);
390	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
391		int lnum = nnode->nbranch[i].lnum;
392
393		if (lnum == 0)
394			lnum = c->lpt_last + 1;
395		pack_bits(&addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
396		pack_bits(&addr, &pos, nnode->nbranch[i].offs,
397			  c->lpt_offs_bits);
398	}
399	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
400		    c->nnode_sz - UBIFS_LPT_CRC_BYTES);
401	addr = buf;
402	pos = 0;
403	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
404}
405
406/**
407 * ubifs_pack_ltab - pack the LPT's own lprops table.
408 * @c: UBIFS file-system description object
409 * @buf: buffer into which to pack
410 * @ltab: LPT's own lprops table to pack
411 */
412void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
413		     struct ubifs_lpt_lprops *ltab)
414{
415	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
416	int i, pos = 0;
417	uint16_t crc;
418
419	pack_bits(&addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
420	for (i = 0; i < c->lpt_lebs; i++) {
421		pack_bits(&addr, &pos, ltab[i].free, c->lpt_spc_bits);
422		pack_bits(&addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
423	}
424	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
425		    c->ltab_sz - UBIFS_LPT_CRC_BYTES);
426	addr = buf;
427	pos = 0;
428	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
429}
430
431/**
432 * ubifs_pack_lsave - pack the LPT's save table.
433 * @c: UBIFS file-system description object
434 * @buf: buffer into which to pack
435 * @lsave: LPT's save table to pack
436 */
437void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
438{
439	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
440	int i, pos = 0;
441	uint16_t crc;
442
443	pack_bits(&addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
444	for (i = 0; i < c->lsave_cnt; i++)
445		pack_bits(&addr, &pos, lsave[i], c->lnum_bits);
446	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
447		    c->lsave_sz - UBIFS_LPT_CRC_BYTES);
448	addr = buf;
449	pos = 0;
450	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
451}
452
453/**
454 * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
455 * @c: UBIFS file-system description object
456 * @lnum: LEB number to which to add dirty space
457 * @dirty: amount of dirty space to add
458 */
459void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
460{
461	if (!dirty || !lnum)
462		return;
463	dbg_lp("LEB %d add %d to %d",
464	       lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
465	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
466	c->ltab[lnum - c->lpt_first].dirty += dirty;
467}
468
469/**
470 * set_ltab - set LPT LEB properties.
471 * @c: UBIFS file-system description object
472 * @lnum: LEB number
473 * @free: amount of free space
474 * @dirty: amount of dirty space
475 */
476static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
477{
478	dbg_lp("LEB %d free %d dirty %d to %d %d",
479	       lnum, c->ltab[lnum - c->lpt_first].free,
480	       c->ltab[lnum - c->lpt_first].dirty, free, dirty);
481	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
482	c->ltab[lnum - c->lpt_first].free = free;
483	c->ltab[lnum - c->lpt_first].dirty = dirty;
484}
485
486/**
487 * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
488 * @c: UBIFS file-system description object
489 * @nnode: nnode for which to add dirt
490 */
491void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
492{
493	struct ubifs_nnode *np = nnode->parent;
494
495	if (np)
496		ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
497				   c->nnode_sz);
498	else {
499		ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
500		if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
501			c->lpt_drty_flgs |= LTAB_DIRTY;
502			ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
503		}
504	}
505}
506
507/**
508 * add_pnode_dirt - add dirty space to LPT LEB properties.
509 * @c: UBIFS file-system description object
510 * @pnode: pnode for which to add dirt
511 */
512static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
513{
514	ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
515			   c->pnode_sz);
516}
517
518/**
519 * calc_nnode_num - calculate nnode number.
520 * @row: the row in the tree (root is zero)
521 * @col: the column in the row (leftmost is zero)
522 *
523 * The nnode number is a number that uniquely identifies a nnode and can be used
524 * easily to traverse the tree from the root to that nnode.
525 *
526 * This function calculates and returns the nnode number for the nnode at @row
527 * and @col.
528 */
529static int calc_nnode_num(int row, int col)
530{
531	int num, bits;
532
533	num = 1;
534	while (row--) {
535		bits = (col & (UBIFS_LPT_FANOUT - 1));
536		col >>= UBIFS_LPT_FANOUT_SHIFT;
537		num <<= UBIFS_LPT_FANOUT_SHIFT;
538		num |= bits;
539	}
540	return num;
541}
542
543/**
544 * calc_nnode_num_from_parent - calculate nnode number.
545 * @c: UBIFS file-system description object
546 * @parent: parent nnode
547 * @iip: index in parent
548 *
549 * The nnode number is a number that uniquely identifies a nnode and can be used
550 * easily to traverse the tree from the root to that nnode.
551 *
552 * This function calculates and returns the nnode number based on the parent's
553 * nnode number and the index in parent.
554 */
555static int calc_nnode_num_from_parent(const struct ubifs_info *c,
556				      struct ubifs_nnode *parent, int iip)
557{
558	int num, shft;
559
560	if (!parent)
561		return 1;
562	shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
563	num = parent->num ^ (1 << shft);
564	num |= (UBIFS_LPT_FANOUT + iip) << shft;
565	return num;
566}
567
568/**
569 * calc_pnode_num_from_parent - calculate pnode number.
570 * @c: UBIFS file-system description object
571 * @parent: parent nnode
572 * @iip: index in parent
573 *
574 * The pnode number is a number that uniquely identifies a pnode and can be used
575 * easily to traverse the tree from the root to that pnode.
576 *
577 * This function calculates and returns the pnode number based on the parent's
578 * nnode number and the index in parent.
579 */
580static int calc_pnode_num_from_parent(const struct ubifs_info *c,
581				      struct ubifs_nnode *parent, int iip)
582{
583	int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
584
585	for (i = 0; i < n; i++) {
586		num <<= UBIFS_LPT_FANOUT_SHIFT;
587		num |= pnum & (UBIFS_LPT_FANOUT - 1);
588		pnum >>= UBIFS_LPT_FANOUT_SHIFT;
589	}
590	num <<= UBIFS_LPT_FANOUT_SHIFT;
591	num |= iip;
592	return num;
593}
594
595/**
596 * ubifs_create_dflt_lpt - create default LPT.
597 * @c: UBIFS file-system description object
598 * @main_lebs: number of main area LEBs is passed and returned here
599 * @lpt_first: LEB number of first LPT LEB
600 * @lpt_lebs: number of LEBs for LPT is passed and returned here
601 * @big_lpt: use big LPT model is passed and returned here
602 *
603 * This function returns %0 on success and a negative error code on failure.
604 */
605int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
606			  int *lpt_lebs, int *big_lpt)
607{
608	int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
609	int blnum, boffs, bsz, bcnt;
610	struct ubifs_pnode *pnode = NULL;
611	struct ubifs_nnode *nnode = NULL;
612	void *buf = NULL, *p;
613	struct ubifs_lpt_lprops *ltab = NULL;
614	int *lsave = NULL;
615
616	err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
617	if (err)
618		return err;
619	*lpt_lebs = c->lpt_lebs;
620
621	/* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
622	c->lpt_first = lpt_first;
623	/* Needed by 'set_ltab()' */
624	c->lpt_last = lpt_first + c->lpt_lebs - 1;
625	/* Needed by 'ubifs_pack_lsave()' */
626	c->main_first = c->leb_cnt - *main_lebs;
627
628	lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_KERNEL);
629	pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
630	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
631	buf = vmalloc(c->leb_size);
632	ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
633	if (!pnode || !nnode || !buf || !ltab || !lsave) {
634		err = -ENOMEM;
635		goto out;
636	}
637
638	ubifs_assert(!c->ltab);
639	c->ltab = ltab; /* Needed by set_ltab */
640
641	/* Initialize LPT's own lprops */
642	for (i = 0; i < c->lpt_lebs; i++) {
643		ltab[i].free = c->leb_size;
644		ltab[i].dirty = 0;
645		ltab[i].tgc = 0;
646		ltab[i].cmt = 0;
647	}
648
649	lnum = lpt_first;
650	p = buf;
651	/* Number of leaf nodes (pnodes) */
652	cnt = c->pnode_cnt;
653
654	/*
655	 * The first pnode contains the LEB properties for the LEBs that contain
656	 * the root inode node and the root index node of the index tree.
657	 */
658	node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
659	iopos = ALIGN(node_sz, c->min_io_size);
660	pnode->lprops[0].free = c->leb_size - iopos;
661	pnode->lprops[0].dirty = iopos - node_sz;
662	pnode->lprops[0].flags = LPROPS_INDEX;
663
664	node_sz = UBIFS_INO_NODE_SZ;
665	iopos = ALIGN(node_sz, c->min_io_size);
666	pnode->lprops[1].free = c->leb_size - iopos;
667	pnode->lprops[1].dirty = iopos - node_sz;
668
669	for (i = 2; i < UBIFS_LPT_FANOUT; i++)
670		pnode->lprops[i].free = c->leb_size;
671
672	/* Add first pnode */
673	ubifs_pack_pnode(c, p, pnode);
674	p += c->pnode_sz;
675	len = c->pnode_sz;
676	pnode->num += 1;
677
678	/* Reset pnode values for remaining pnodes */
679	pnode->lprops[0].free = c->leb_size;
680	pnode->lprops[0].dirty = 0;
681	pnode->lprops[0].flags = 0;
682
683	pnode->lprops[1].free = c->leb_size;
684	pnode->lprops[1].dirty = 0;
685
686	/*
687	 * To calculate the internal node branches, we keep information about
688	 * the level below.
689	 */
690	blnum = lnum; /* LEB number of level below */
691	boffs = 0; /* Offset of level below */
692	bcnt = cnt; /* Number of nodes in level below */
693	bsz = c->pnode_sz; /* Size of nodes in level below */
694
695	/* Add all remaining pnodes */
696	for (i = 1; i < cnt; i++) {
697		if (len + c->pnode_sz > c->leb_size) {
698			alen = ALIGN(len, c->min_io_size);
699			set_ltab(c, lnum, c->leb_size - alen, alen - len);
700			memset(p, 0xff, alen - len);
701			err = ubifs_leb_change(c, lnum++, buf, alen);
702			if (err)
703				goto out;
704			p = buf;
705			len = 0;
706		}
707		ubifs_pack_pnode(c, p, pnode);
708		p += c->pnode_sz;
709		len += c->pnode_sz;
710		/*
711		 * pnodes are simply numbered left to right starting at zero,
712		 * which means the pnode number can be used easily to traverse
713		 * down the tree to the corresponding pnode.
714		 */
715		pnode->num += 1;
716	}
717
718	row = 0;
719	for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
720		row += 1;
721	/* Add all nnodes, one level at a time */
722	while (1) {
723		/* Number of internal nodes (nnodes) at next level */
724		cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
725		for (i = 0; i < cnt; i++) {
726			if (len + c->nnode_sz > c->leb_size) {
727				alen = ALIGN(len, c->min_io_size);
728				set_ltab(c, lnum, c->leb_size - alen,
729					    alen - len);
730				memset(p, 0xff, alen - len);
731				err = ubifs_leb_change(c, lnum++, buf, alen);
732				if (err)
733					goto out;
734				p = buf;
735				len = 0;
736			}
737			/* Only 1 nnode at this level, so it is the root */
738			if (cnt == 1) {
739				c->lpt_lnum = lnum;
740				c->lpt_offs = len;
741			}
742			/* Set branches to the level below */
743			for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
744				if (bcnt) {
745					if (boffs + bsz > c->leb_size) {
746						blnum += 1;
747						boffs = 0;
748					}
749					nnode->nbranch[j].lnum = blnum;
750					nnode->nbranch[j].offs = boffs;
751					boffs += bsz;
752					bcnt--;
753				} else {
754					nnode->nbranch[j].lnum = 0;
755					nnode->nbranch[j].offs = 0;
756				}
757			}
758			nnode->num = calc_nnode_num(row, i);
759			ubifs_pack_nnode(c, p, nnode);
760			p += c->nnode_sz;
761			len += c->nnode_sz;
762		}
763		/* Only 1 nnode at this level, so it is the root */
764		if (cnt == 1)
765			break;
766		/* Update the information about the level below */
767		bcnt = cnt;
768		bsz = c->nnode_sz;
769		row -= 1;
770	}
771
772	if (*big_lpt) {
773		/* Need to add LPT's save table */
774		if (len + c->lsave_sz > c->leb_size) {
775			alen = ALIGN(len, c->min_io_size);
776			set_ltab(c, lnum, c->leb_size - alen, alen - len);
777			memset(p, 0xff, alen - len);
778			err = ubifs_leb_change(c, lnum++, buf, alen);
779			if (err)
780				goto out;
781			p = buf;
782			len = 0;
783		}
784
785		c->lsave_lnum = lnum;
786		c->lsave_offs = len;
787
788		for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
789			lsave[i] = c->main_first + i;
790		for (; i < c->lsave_cnt; i++)
791			lsave[i] = c->main_first;
792
793		ubifs_pack_lsave(c, p, lsave);
794		p += c->lsave_sz;
795		len += c->lsave_sz;
796	}
797
798	/* Need to add LPT's own LEB properties table */
799	if (len + c->ltab_sz > c->leb_size) {
800		alen = ALIGN(len, c->min_io_size);
801		set_ltab(c, lnum, c->leb_size - alen, alen - len);
802		memset(p, 0xff, alen - len);
803		err = ubifs_leb_change(c, lnum++, buf, alen);
804		if (err)
805			goto out;
806		p = buf;
807		len = 0;
808	}
809
810	c->ltab_lnum = lnum;
811	c->ltab_offs = len;
812
813	/* Update ltab before packing it */
814	len += c->ltab_sz;
815	alen = ALIGN(len, c->min_io_size);
816	set_ltab(c, lnum, c->leb_size - alen, alen - len);
817
818	ubifs_pack_ltab(c, p, ltab);
819	p += c->ltab_sz;
820
821	/* Write remaining buffer */
822	memset(p, 0xff, alen - len);
823	err = ubifs_leb_change(c, lnum, buf, alen);
824	if (err)
825		goto out;
826
827	c->nhead_lnum = lnum;
828	c->nhead_offs = ALIGN(len, c->min_io_size);
829
830	dbg_lp("space_bits %d", c->space_bits);
831	dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
832	dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
833	dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
834	dbg_lp("pcnt_bits %d", c->pcnt_bits);
835	dbg_lp("lnum_bits %d", c->lnum_bits);
836	dbg_lp("pnode_sz %d", c->pnode_sz);
837	dbg_lp("nnode_sz %d", c->nnode_sz);
838	dbg_lp("ltab_sz %d", c->ltab_sz);
839	dbg_lp("lsave_sz %d", c->lsave_sz);
840	dbg_lp("lsave_cnt %d", c->lsave_cnt);
841	dbg_lp("lpt_hght %d", c->lpt_hght);
842	dbg_lp("big_lpt %d", c->big_lpt);
843	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
844	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
845	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
846	if (c->big_lpt)
847		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
848out:
849	c->ltab = NULL;
850	kfree(lsave);
851	vfree(ltab);
852	vfree(buf);
853	kfree(nnode);
854	kfree(pnode);
855	return err;
856}
857
858/**
859 * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
860 * @c: UBIFS file-system description object
861 * @pnode: pnode
862 *
863 * When a pnode is loaded into memory, the LEB properties it contains are added,
864 * by this function, to the LEB category lists and heaps.
865 */
866static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
867{
868	int i;
869
870	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
871		int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
872		int lnum = pnode->lprops[i].lnum;
873
874		if (!lnum)
875			return;
876		ubifs_add_to_cat(c, &pnode->lprops[i], cat);
877	}
878}
879
880/**
881 * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
882 * @c: UBIFS file-system description object
883 * @old_pnode: pnode copied
884 * @new_pnode: pnode copy
885 *
886 * During commit it is sometimes necessary to copy a pnode
887 * (see dirty_cow_pnode).  When that happens, references in
888 * category lists and heaps must be replaced.  This function does that.
889 */
890static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
891			 struct ubifs_pnode *new_pnode)
892{
893	int i;
894
895	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
896		if (!new_pnode->lprops[i].lnum)
897			return;
898		ubifs_replace_cat(c, &old_pnode->lprops[i],
899				  &new_pnode->lprops[i]);
900	}
901}
902
903/**
904 * check_lpt_crc - check LPT node crc is correct.
905 * @c: UBIFS file-system description object
906 * @buf: buffer containing node
907 * @len: length of node
908 *
909 * This function returns %0 on success and a negative error code on failure.
910 */
911static int check_lpt_crc(const struct ubifs_info *c, void *buf, int len)
912{
913	int pos = 0;
914	uint8_t *addr = buf;
915	uint16_t crc, calc_crc;
916
917	crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
918	calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
919			 len - UBIFS_LPT_CRC_BYTES);
920	if (crc != calc_crc) {
921		ubifs_err(c, "invalid crc in LPT node: crc %hx calc %hx",
922			  crc, calc_crc);
923		dump_stack();
924		return -EINVAL;
925	}
926	return 0;
927}
928
929/**
930 * check_lpt_type - check LPT node type is correct.
931 * @c: UBIFS file-system description object
932 * @addr: address of type bit field is passed and returned updated here
933 * @pos: position of type bit field is passed and returned updated here
934 * @type: expected type
935 *
936 * This function returns %0 on success and a negative error code on failure.
937 */
938static int check_lpt_type(const struct ubifs_info *c, uint8_t **addr,
939			  int *pos, int type)
940{
941	int node_type;
942
943	node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
944	if (node_type != type) {
945		ubifs_err(c, "invalid type (%d) in LPT node type %d",
946			  node_type, type);
947		dump_stack();
948		return -EINVAL;
949	}
950	return 0;
951}
952
953/**
954 * unpack_pnode - unpack a pnode.
955 * @c: UBIFS file-system description object
956 * @buf: buffer containing packed pnode to unpack
957 * @pnode: pnode structure to fill
958 *
959 * This function returns %0 on success and a negative error code on failure.
960 */
961static int unpack_pnode(const struct ubifs_info *c, void *buf,
962			struct ubifs_pnode *pnode)
963{
964	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
965	int i, pos = 0, err;
966
967	err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_PNODE);
968	if (err)
969		return err;
970	if (c->big_lpt)
971		pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
972	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
973		struct ubifs_lprops * const lprops = &pnode->lprops[i];
974
975		lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
976		lprops->free <<= 3;
977		lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
978		lprops->dirty <<= 3;
979
980		if (ubifs_unpack_bits(&addr, &pos, 1))
981			lprops->flags = LPROPS_INDEX;
982		else
983			lprops->flags = 0;
984		lprops->flags |= ubifs_categorize_lprops(c, lprops);
985	}
986	err = check_lpt_crc(c, buf, c->pnode_sz);
987	return err;
988}
989
990/**
991 * ubifs_unpack_nnode - unpack a nnode.
992 * @c: UBIFS file-system description object
993 * @buf: buffer containing packed nnode to unpack
994 * @nnode: nnode structure to fill
995 *
996 * This function returns %0 on success and a negative error code on failure.
997 */
998int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
999		       struct ubifs_nnode *nnode)
1000{
1001	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1002	int i, pos = 0, err;
1003
1004	err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_NNODE);
1005	if (err)
1006		return err;
1007	if (c->big_lpt)
1008		nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1009	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1010		int lnum;
1011
1012		lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
1013		       c->lpt_first;
1014		if (lnum == c->lpt_last + 1)
1015			lnum = 0;
1016		nnode->nbranch[i].lnum = lnum;
1017		nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
1018						     c->lpt_offs_bits);
1019	}
1020	err = check_lpt_crc(c, buf, c->nnode_sz);
1021	return err;
1022}
1023
1024/**
1025 * unpack_ltab - unpack the LPT's own lprops table.
1026 * @c: UBIFS file-system description object
1027 * @buf: buffer from which to unpack
1028 *
1029 * This function returns %0 on success and a negative error code on failure.
1030 */
1031static int unpack_ltab(const struct ubifs_info *c, void *buf)
1032{
1033	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1034	int i, pos = 0, err;
1035
1036	err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LTAB);
1037	if (err)
1038		return err;
1039	for (i = 0; i < c->lpt_lebs; i++) {
1040		int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1041		int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1042
1043		if (free < 0 || free > c->leb_size || dirty < 0 ||
1044		    dirty > c->leb_size || free + dirty > c->leb_size)
1045			return -EINVAL;
1046
1047		c->ltab[i].free = free;
1048		c->ltab[i].dirty = dirty;
1049		c->ltab[i].tgc = 0;
1050		c->ltab[i].cmt = 0;
1051	}
1052	err = check_lpt_crc(c, buf, c->ltab_sz);
1053	return err;
1054}
1055
1056#ifndef __UBOOT__
1057/**
1058 * unpack_lsave - unpack the LPT's save table.
1059 * @c: UBIFS file-system description object
1060 * @buf: buffer from which to unpack
1061 *
1062 * This function returns %0 on success and a negative error code on failure.
1063 */
1064static int unpack_lsave(const struct ubifs_info *c, void *buf)
1065{
1066	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1067	int i, pos = 0, err;
1068
1069	err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LSAVE);
1070	if (err)
1071		return err;
1072	for (i = 0; i < c->lsave_cnt; i++) {
1073		int lnum = ubifs_unpack_bits(&addr, &pos, c->lnum_bits);
1074
1075		if (lnum < c->main_first || lnum >= c->leb_cnt)
1076			return -EINVAL;
1077		c->lsave[i] = lnum;
1078	}
1079	err = check_lpt_crc(c, buf, c->lsave_sz);
1080	return err;
1081}
1082#endif
1083
1084/**
1085 * validate_nnode - validate a nnode.
1086 * @c: UBIFS file-system description object
1087 * @nnode: nnode to validate
1088 * @parent: parent nnode (or NULL for the root nnode)
1089 * @iip: index in parent
1090 *
1091 * This function returns %0 on success and a negative error code on failure.
1092 */
1093static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
1094			  struct ubifs_nnode *parent, int iip)
1095{
1096	int i, lvl, max_offs;
1097
1098	if (c->big_lpt) {
1099		int num = calc_nnode_num_from_parent(c, parent, iip);
1100
1101		if (nnode->num != num)
1102			return -EINVAL;
1103	}
1104	lvl = parent ? parent->level - 1 : c->lpt_hght;
1105	if (lvl < 1)
1106		return -EINVAL;
1107	if (lvl == 1)
1108		max_offs = c->leb_size - c->pnode_sz;
1109	else
1110		max_offs = c->leb_size - c->nnode_sz;
1111	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1112		int lnum = nnode->nbranch[i].lnum;
1113		int offs = nnode->nbranch[i].offs;
1114
1115		if (lnum == 0) {
1116			if (offs != 0)
1117				return -EINVAL;
1118			continue;
1119		}
1120		if (lnum < c->lpt_first || lnum > c->lpt_last)
1121			return -EINVAL;
1122		if (offs < 0 || offs > max_offs)
1123			return -EINVAL;
1124	}
1125	return 0;
1126}
1127
1128/**
1129 * validate_pnode - validate a pnode.
1130 * @c: UBIFS file-system description object
1131 * @pnode: pnode to validate
1132 * @parent: parent nnode
1133 * @iip: index in parent
1134 *
1135 * This function returns %0 on success and a negative error code on failure.
1136 */
1137static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
1138			  struct ubifs_nnode *parent, int iip)
1139{
1140	int i;
1141
1142	if (c->big_lpt) {
1143		int num = calc_pnode_num_from_parent(c, parent, iip);
1144
1145		if (pnode->num != num)
1146			return -EINVAL;
1147	}
1148	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1149		int free = pnode->lprops[i].free;
1150		int dirty = pnode->lprops[i].dirty;
1151
1152		if (free < 0 || free > c->leb_size || free % c->min_io_size ||
1153		    (free & 7))
1154			return -EINVAL;
1155		if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
1156			return -EINVAL;
1157		if (dirty + free > c->leb_size)
1158			return -EINVAL;
1159	}
1160	return 0;
1161}
1162
1163/**
1164 * set_pnode_lnum - set LEB numbers on a pnode.
1165 * @c: UBIFS file-system description object
1166 * @pnode: pnode to update
1167 *
1168 * This function calculates the LEB numbers for the LEB properties it contains
1169 * based on the pnode number.
1170 */
1171static void set_pnode_lnum(const struct ubifs_info *c,
1172			   struct ubifs_pnode *pnode)
1173{
1174	int i, lnum;
1175
1176	lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
1177	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1178		if (lnum >= c->leb_cnt)
1179			return;
1180		pnode->lprops[i].lnum = lnum++;
1181	}
1182}
1183
1184/**
1185 * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
1186 * @c: UBIFS file-system description object
1187 * @parent: parent nnode (or NULL for the root)
1188 * @iip: index in parent
1189 *
1190 * This function returns %0 on success and a negative error code on failure.
1191 */
1192int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1193{
1194	struct ubifs_nbranch *branch = NULL;
1195	struct ubifs_nnode *nnode = NULL;
1196	void *buf = c->lpt_nod_buf;
1197	int err, lnum, offs;
1198
1199	if (parent) {
1200		branch = &parent->nbranch[iip];
1201		lnum = branch->lnum;
1202		offs = branch->offs;
1203	} else {
1204		lnum = c->lpt_lnum;
1205		offs = c->lpt_offs;
1206	}
1207	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1208	if (!nnode) {
1209		err = -ENOMEM;
1210		goto out;
1211	}
1212	if (lnum == 0) {
1213		/*
1214		 * This nnode was not written which just means that the LEB
1215		 * properties in the subtree below it describe empty LEBs. We
1216		 * make the nnode as though we had read it, which in fact means
1217		 * doing almost nothing.
1218		 */
1219		if (c->big_lpt)
1220			nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1221	} else {
1222		err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1);
1223		if (err)
1224			goto out;
1225		err = ubifs_unpack_nnode(c, buf, nnode);
1226		if (err)
1227			goto out;
1228	}
1229	err = validate_nnode(c, nnode, parent, iip);
1230	if (err)
1231		goto out;
1232	if (!c->big_lpt)
1233		nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1234	if (parent) {
1235		branch->nnode = nnode;
1236		nnode->level = parent->level - 1;
1237	} else {
1238		c->nroot = nnode;
1239		nnode->level = c->lpt_hght;
1240	}
1241	nnode->parent = parent;
1242	nnode->iip = iip;
1243	return 0;
1244
1245out:
1246	ubifs_err(c, "error %d reading nnode at %d:%d", err, lnum, offs);
1247	dump_stack();
1248	kfree(nnode);
1249	return err;
1250}
1251
1252/**
1253 * read_pnode - read a pnode from flash and link it to the tree in memory.
1254 * @c: UBIFS file-system description object
1255 * @parent: parent nnode
1256 * @iip: index in parent
1257 *
1258 * This function returns %0 on success and a negative error code on failure.
1259 */
1260static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1261{
1262	struct ubifs_nbranch *branch;
1263	struct ubifs_pnode *pnode = NULL;
1264	void *buf = c->lpt_nod_buf;
1265	int err, lnum, offs;
1266
1267	branch = &parent->nbranch[iip];
1268	lnum = branch->lnum;
1269	offs = branch->offs;
1270	pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1271	if (!pnode)
1272		return -ENOMEM;
1273
1274	if (lnum == 0) {
1275		/*
1276		 * This pnode was not written which just means that the LEB
1277		 * properties in it describe empty LEBs. We make the pnode as
1278		 * though we had read it.
1279		 */
1280		int i;
1281
1282		if (c->big_lpt)
1283			pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1284		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1285			struct ubifs_lprops * const lprops = &pnode->lprops[i];
1286
1287			lprops->free = c->leb_size;
1288			lprops->flags = ubifs_categorize_lprops(c, lprops);
1289		}
1290	} else {
1291		err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1);
1292		if (err)
1293			goto out;
1294		err = unpack_pnode(c, buf, pnode);
1295		if (err)
1296			goto out;
1297	}
1298	err = validate_pnode(c, pnode, parent, iip);
1299	if (err)
1300		goto out;
1301	if (!c->big_lpt)
1302		pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1303	branch->pnode = pnode;
1304	pnode->parent = parent;
1305	pnode->iip = iip;
1306	set_pnode_lnum(c, pnode);
1307	c->pnodes_have += 1;
1308	return 0;
1309
1310out:
1311	ubifs_err(c, "error %d reading pnode at %d:%d", err, lnum, offs);
1312	ubifs_dump_pnode(c, pnode, parent, iip);
1313	dump_stack();
1314	ubifs_err(c, "calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
1315	kfree(pnode);
1316	return err;
1317}
1318
1319/**
1320 * read_ltab - read LPT's own lprops table.
1321 * @c: UBIFS file-system description object
1322 *
1323 * This function returns %0 on success and a negative error code on failure.
1324 */
1325static int read_ltab(struct ubifs_info *c)
1326{
1327	int err;
1328	void *buf;
1329
1330	buf = vmalloc(c->ltab_sz);
1331	if (!buf)
1332		return -ENOMEM;
1333	err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1);
1334	if (err)
1335		goto out;
1336	err = unpack_ltab(c, buf);
1337out:
1338	vfree(buf);
1339	return err;
1340}
1341
1342#ifndef __UBOOT__
1343/**
1344 * read_lsave - read LPT's save table.
1345 * @c: UBIFS file-system description object
1346 *
1347 * This function returns %0 on success and a negative error code on failure.
1348 */
1349static int read_lsave(struct ubifs_info *c)
1350{
1351	int err, i;
1352	void *buf;
1353
1354	buf = vmalloc(c->lsave_sz);
1355	if (!buf)
1356		return -ENOMEM;
1357	err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs,
1358			     c->lsave_sz, 1);
1359	if (err)
1360		goto out;
1361	err = unpack_lsave(c, buf);
1362	if (err)
1363		goto out;
1364	for (i = 0; i < c->lsave_cnt; i++) {
1365		int lnum = c->lsave[i];
1366		struct ubifs_lprops *lprops;
1367
1368		/*
1369		 * Due to automatic resizing, the values in the lsave table
1370		 * could be beyond the volume size - just ignore them.
1371		 */
1372		if (lnum >= c->leb_cnt)
1373			continue;
1374		lprops = ubifs_lpt_lookup(c, lnum);
1375		if (IS_ERR(lprops)) {
1376			err = PTR_ERR(lprops);
1377			goto out;
1378		}
1379	}
1380out:
1381	vfree(buf);
1382	return err;
1383}
1384#endif
1385
1386/**
1387 * ubifs_get_nnode - get a nnode.
1388 * @c: UBIFS file-system description object
1389 * @parent: parent nnode (or NULL for the root)
1390 * @iip: index in parent
1391 *
1392 * This function returns a pointer to the nnode on success or a negative error
1393 * code on failure.
1394 */
1395struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
1396				    struct ubifs_nnode *parent, int iip)
1397{
1398	struct ubifs_nbranch *branch;
1399	struct ubifs_nnode *nnode;
1400	int err;
1401
1402	branch = &parent->nbranch[iip];
1403	nnode = branch->nnode;
1404	if (nnode)
1405		return nnode;
1406	err = ubifs_read_nnode(c, parent, iip);
1407	if (err)
1408		return ERR_PTR(err);
1409	return branch->nnode;
1410}
1411
1412/**
1413 * ubifs_get_pnode - get a pnode.
1414 * @c: UBIFS file-system description object
1415 * @parent: parent nnode
1416 * @iip: index in parent
1417 *
1418 * This function returns a pointer to the pnode on success or a negative error
1419 * code on failure.
1420 */
1421struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
1422				    struct ubifs_nnode *parent, int iip)
1423{
1424	struct ubifs_nbranch *branch;
1425	struct ubifs_pnode *pnode;
1426	int err;
1427
1428	branch = &parent->nbranch[iip];
1429	pnode = branch->pnode;
1430	if (pnode)
1431		return pnode;
1432	err = read_pnode(c, parent, iip);
1433	if (err)
1434		return ERR_PTR(err);
1435	update_cats(c, branch->pnode);
1436	return branch->pnode;
1437}
1438
1439/**
1440 * ubifs_lpt_lookup - lookup LEB properties in the LPT.
1441 * @c: UBIFS file-system description object
1442 * @lnum: LEB number to lookup
1443 *
1444 * This function returns a pointer to the LEB properties on success or a
1445 * negative error code on failure.
1446 */
1447struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
1448{
1449	int err, i, h, iip, shft;
1450	struct ubifs_nnode *nnode;
1451	struct ubifs_pnode *pnode;
1452
1453	if (!c->nroot) {
1454		err = ubifs_read_nnode(c, NULL, 0);
1455		if (err)
1456			return ERR_PTR(err);
1457	}
1458	nnode = c->nroot;
1459	i = lnum - c->main_first;
1460	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1461	for (h = 1; h < c->lpt_hght; h++) {
1462		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1463		shft -= UBIFS_LPT_FANOUT_SHIFT;
1464		nnode = ubifs_get_nnode(c, nnode, iip);
1465		if (IS_ERR(nnode))
1466			return ERR_CAST(nnode);
1467	}
1468	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1469	pnode = ubifs_get_pnode(c, nnode, iip);
1470	if (IS_ERR(pnode))
1471		return ERR_CAST(pnode);
1472	iip = (i & (UBIFS_LPT_FANOUT - 1));
1473	dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1474	       pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1475	       pnode->lprops[iip].flags);
1476	return &pnode->lprops[iip];
1477}
1478
1479/**
1480 * dirty_cow_nnode - ensure a nnode is not being committed.
1481 * @c: UBIFS file-system description object
1482 * @nnode: nnode to check
1483 *
1484 * Returns dirtied nnode on success or negative error code on failure.
1485 */
1486static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
1487					   struct ubifs_nnode *nnode)
1488{
1489	struct ubifs_nnode *n;
1490	int i;
1491
1492	if (!test_bit(COW_CNODE, &nnode->flags)) {
1493		/* nnode is not being committed */
1494		if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
1495			c->dirty_nn_cnt += 1;
1496			ubifs_add_nnode_dirt(c, nnode);
1497		}
1498		return nnode;
1499	}
1500
1501	/* nnode is being committed, so copy it */
1502	n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1503	if (unlikely(!n))
1504		return ERR_PTR(-ENOMEM);
1505
1506	memcpy(n, nnode, sizeof(struct ubifs_nnode));
1507	n->cnext = NULL;
1508	__set_bit(DIRTY_CNODE, &n->flags);
1509	__clear_bit(COW_CNODE, &n->flags);
1510
1511	/* The children now have new parent */
1512	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1513		struct ubifs_nbranch *branch = &n->nbranch[i];
1514
1515		if (branch->cnode)
1516			branch->cnode->parent = n;
1517	}
1518
1519	ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
1520	__set_bit(OBSOLETE_CNODE, &nnode->flags);
1521
1522	c->dirty_nn_cnt += 1;
1523	ubifs_add_nnode_dirt(c, nnode);
1524	if (nnode->parent)
1525		nnode->parent->nbranch[n->iip].nnode = n;
1526	else
1527		c->nroot = n;
1528	return n;
1529}
1530
1531/**
1532 * dirty_cow_pnode - ensure a pnode is not being committed.
1533 * @c: UBIFS file-system description object
1534 * @pnode: pnode to check
1535 *
1536 * Returns dirtied pnode on success or negative error code on failure.
1537 */
1538static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
1539					   struct ubifs_pnode *pnode)
1540{
1541	struct ubifs_pnode *p;
1542
1543	if (!test_bit(COW_CNODE, &pnode->flags)) {
1544		/* pnode is not being committed */
1545		if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
1546			c->dirty_pn_cnt += 1;
1547			add_pnode_dirt(c, pnode);
1548		}
1549		return pnode;
1550	}
1551
1552	/* pnode is being committed, so copy it */
1553	p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1554	if (unlikely(!p))
1555		return ERR_PTR(-ENOMEM);
1556
1557	memcpy(p, pnode, sizeof(struct ubifs_pnode));
1558	p->cnext = NULL;
1559	__set_bit(DIRTY_CNODE, &p->flags);
1560	__clear_bit(COW_CNODE, &p->flags);
1561	replace_cats(c, pnode, p);
1562
1563	ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
1564	__set_bit(OBSOLETE_CNODE, &pnode->flags);
1565
1566	c->dirty_pn_cnt += 1;
1567	add_pnode_dirt(c, pnode);
1568	pnode->parent->nbranch[p->iip].pnode = p;
1569	return p;
1570}
1571
1572/**
1573 * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
1574 * @c: UBIFS file-system description object
1575 * @lnum: LEB number to lookup
1576 *
1577 * This function returns a pointer to the LEB properties on success or a
1578 * negative error code on failure.
1579 */
1580struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
1581{
1582	int err, i, h, iip, shft;
1583	struct ubifs_nnode *nnode;
1584	struct ubifs_pnode *pnode;
1585
1586	if (!c->nroot) {
1587		err = ubifs_read_nnode(c, NULL, 0);
1588		if (err)
1589			return ERR_PTR(err);
1590	}
1591	nnode = c->nroot;
1592	nnode = dirty_cow_nnode(c, nnode);
1593	if (IS_ERR(nnode))
1594		return ERR_CAST(nnode);
1595	i = lnum - c->main_first;
1596	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1597	for (h = 1; h < c->lpt_hght; h++) {
1598		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1599		shft -= UBIFS_LPT_FANOUT_SHIFT;
1600		nnode = ubifs_get_nnode(c, nnode, iip);
1601		if (IS_ERR(nnode))
1602			return ERR_CAST(nnode);
1603		nnode = dirty_cow_nnode(c, nnode);
1604		if (IS_ERR(nnode))
1605			return ERR_CAST(nnode);
1606	}
1607	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1608	pnode = ubifs_get_pnode(c, nnode, iip);
1609	if (IS_ERR(pnode))
1610		return ERR_CAST(pnode);
1611	pnode = dirty_cow_pnode(c, pnode);
1612	if (IS_ERR(pnode))
1613		return ERR_CAST(pnode);
1614	iip = (i & (UBIFS_LPT_FANOUT - 1));
1615	dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1616	       pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1617	       pnode->lprops[iip].flags);
1618	ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
1619	return &pnode->lprops[iip];
1620}
1621
1622/**
1623 * lpt_init_rd - initialize the LPT for reading.
1624 * @c: UBIFS file-system description object
1625 *
1626 * This function returns %0 on success and a negative error code on failure.
1627 */
1628static int lpt_init_rd(struct ubifs_info *c)
1629{
1630	int err, i;
1631
1632	c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1633	if (!c->ltab)
1634		return -ENOMEM;
1635
1636	i = max_t(int, c->nnode_sz, c->pnode_sz);
1637	c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
1638	if (!c->lpt_nod_buf)
1639		return -ENOMEM;
1640
1641	for (i = 0; i < LPROPS_HEAP_CNT; i++) {
1642		c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
1643					     GFP_KERNEL);
1644		if (!c->lpt_heap[i].arr)
1645			return -ENOMEM;
1646		c->lpt_heap[i].cnt = 0;
1647		c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
1648	}
1649
1650	c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
1651	if (!c->dirty_idx.arr)
1652		return -ENOMEM;
1653	c->dirty_idx.cnt = 0;
1654	c->dirty_idx.max_cnt = LPT_HEAP_SZ;
1655
1656	err = read_ltab(c);
1657	if (err)
1658		return err;
1659
1660	dbg_lp("space_bits %d", c->space_bits);
1661	dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
1662	dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
1663	dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
1664	dbg_lp("pcnt_bits %d", c->pcnt_bits);
1665	dbg_lp("lnum_bits %d", c->lnum_bits);
1666	dbg_lp("pnode_sz %d", c->pnode_sz);
1667	dbg_lp("nnode_sz %d", c->nnode_sz);
1668	dbg_lp("ltab_sz %d", c->ltab_sz);
1669	dbg_lp("lsave_sz %d", c->lsave_sz);
1670	dbg_lp("lsave_cnt %d", c->lsave_cnt);
1671	dbg_lp("lpt_hght %d", c->lpt_hght);
1672	dbg_lp("big_lpt %d", c->big_lpt);
1673	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
1674	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
1675	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
1676	if (c->big_lpt)
1677		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
1678
1679	return 0;
1680}
1681
1682#ifndef __UBOOT__
1683/**
1684 * lpt_init_wr - initialize the LPT for writing.
1685 * @c: UBIFS file-system description object
1686 *
1687 * 'lpt_init_rd()' must have been called already.
1688 *
1689 * This function returns %0 on success and a negative error code on failure.
1690 */
1691static int lpt_init_wr(struct ubifs_info *c)
1692{
1693	int err, i;
1694
1695	c->ltab_cmt = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1696	if (!c->ltab_cmt)
1697		return -ENOMEM;
1698
1699	c->lpt_buf = vmalloc(c->leb_size);
1700	if (!c->lpt_buf)
1701		return -ENOMEM;
1702
1703	if (c->big_lpt) {
1704		c->lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_NOFS);
1705		if (!c->lsave)
1706			return -ENOMEM;
1707		err = read_lsave(c);
1708		if (err)
1709			return err;
1710	}
1711
1712	for (i = 0; i < c->lpt_lebs; i++)
1713		if (c->ltab[i].free == c->leb_size) {
1714			err = ubifs_leb_unmap(c, i + c->lpt_first);
1715			if (err)
1716				return err;
1717		}
1718
1719	return 0;
1720}
1721#endif
1722
1723/**
1724 * ubifs_lpt_init - initialize the LPT.
1725 * @c: UBIFS file-system description object
1726 * @rd: whether to initialize lpt for reading
1727 * @wr: whether to initialize lpt for writing
1728 *
1729 * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
1730 * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
1731 * true.
1732 *
1733 * This function returns %0 on success and a negative error code on failure.
1734 */
1735int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
1736{
1737	int err;
1738
1739	if (rd) {
1740		err = lpt_init_rd(c);
1741		if (err)
1742			goto out_err;
1743	}
1744
1745#ifndef __UBOOT__
1746	if (wr) {
1747		err = lpt_init_wr(c);
1748		if (err)
1749			goto out_err;
1750	}
1751#endif
1752
1753	return 0;
1754
1755out_err:
1756#ifndef __UBOOT__
1757	if (wr)
1758		ubifs_lpt_free(c, 1);
1759#endif
1760	if (rd)
1761		ubifs_lpt_free(c, 0);
1762	return err;
1763}
1764
1765/**
1766 * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
1767 * @nnode: where to keep a nnode
1768 * @pnode: where to keep a pnode
1769 * @cnode: where to keep a cnode
1770 * @in_tree: is the node in the tree in memory
1771 * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
1772 * the tree
1773 * @ptr.pnode: ditto for pnode
1774 * @ptr.cnode: ditto for cnode
1775 */
1776struct lpt_scan_node {
1777	union {
1778		struct ubifs_nnode nnode;
1779		struct ubifs_pnode pnode;
1780		struct ubifs_cnode cnode;
1781	};
1782	int in_tree;
1783	union {
1784		struct ubifs_nnode *nnode;
1785		struct ubifs_pnode *pnode;
1786		struct ubifs_cnode *cnode;
1787	} ptr;
1788};
1789
1790/**
1791 * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
1792 * @c: the UBIFS file-system description object
1793 * @path: where to put the nnode
1794 * @parent: parent of the nnode
1795 * @iip: index in parent of the nnode
1796 *
1797 * This function returns a pointer to the nnode on success or a negative error
1798 * code on failure.
1799 */
1800static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
1801					  struct lpt_scan_node *path,
1802					  struct ubifs_nnode *parent, int iip)
1803{
1804	struct ubifs_nbranch *branch;
1805	struct ubifs_nnode *nnode;
1806	void *buf = c->lpt_nod_buf;
1807	int err;
1808
1809	branch = &parent->nbranch[iip];
1810	nnode = branch->nnode;
1811	if (nnode) {
1812		path->in_tree = 1;
1813		path->ptr.nnode = nnode;
1814		return nnode;
1815	}
1816	nnode = &path->nnode;
1817	path->in_tree = 0;
1818	path->ptr.nnode = nnode;
1819	memset(nnode, 0, sizeof(struct ubifs_nnode));
1820	if (branch->lnum == 0) {
1821		/*
1822		 * This nnode was not written which just means that the LEB
1823		 * properties in the subtree below it describe empty LEBs. We
1824		 * make the nnode as though we had read it, which in fact means
1825		 * doing almost nothing.
1826		 */
1827		if (c->big_lpt)
1828			nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1829	} else {
1830		err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1831				     c->nnode_sz, 1);
1832		if (err)
1833			return ERR_PTR(err);
1834		err = ubifs_unpack_nnode(c, buf, nnode);
1835		if (err)
1836			return ERR_PTR(err);
1837	}
1838	err = validate_nnode(c, nnode, parent, iip);
1839	if (err)
1840		return ERR_PTR(err);
1841	if (!c->big_lpt)
1842		nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1843	nnode->level = parent->level - 1;
1844	nnode->parent = parent;
1845	nnode->iip = iip;
1846	return nnode;
1847}
1848
1849/**
1850 * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
1851 * @c: the UBIFS file-system description object
1852 * @path: where to put the pnode
1853 * @parent: parent of the pnode
1854 * @iip: index in parent of the pnode
1855 *
1856 * This function returns a pointer to the pnode on success or a negative error
1857 * code on failure.
1858 */
1859static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
1860					  struct lpt_scan_node *path,
1861					  struct ubifs_nnode *parent, int iip)
1862{
1863	struct ubifs_nbranch *branch;
1864	struct ubifs_pnode *pnode;
1865	void *buf = c->lpt_nod_buf;
1866	int err;
1867
1868	branch = &parent->nbranch[iip];
1869	pnode = branch->pnode;
1870	if (pnode) {
1871		path->in_tree = 1;
1872		path->ptr.pnode = pnode;
1873		return pnode;
1874	}
1875	pnode = &path->pnode;
1876	path->in_tree = 0;
1877	path->ptr.pnode = pnode;
1878	memset(pnode, 0, sizeof(struct ubifs_pnode));
1879	if (branch->lnum == 0) {
1880		/*
1881		 * This pnode was not written which just means that the LEB
1882		 * properties in it describe empty LEBs. We make the pnode as
1883		 * though we had read it.
1884		 */
1885		int i;
1886
1887		if (c->big_lpt)
1888			pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1889		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1890			struct ubifs_lprops * const lprops = &pnode->lprops[i];
1891
1892			lprops->free = c->leb_size;
1893			lprops->flags = ubifs_categorize_lprops(c, lprops);
1894		}
1895	} else {
1896		ubifs_assert(branch->lnum >= c->lpt_first &&
1897			     branch->lnum <= c->lpt_last);
1898		ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
1899		err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1900				     c->pnode_sz, 1);
1901		if (err)
1902			return ERR_PTR(err);
1903		err = unpack_pnode(c, buf, pnode);
1904		if (err)
1905			return ERR_PTR(err);
1906	}
1907	err = validate_pnode(c, pnode, parent, iip);
1908	if (err)
1909		return ERR_PTR(err);
1910	if (!c->big_lpt)
1911		pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1912	pnode->parent = parent;
1913	pnode->iip = iip;
1914	set_pnode_lnum(c, pnode);
1915	return pnode;
1916}
1917
1918/**
1919 * ubifs_lpt_scan_nolock - scan the LPT.
1920 * @c: the UBIFS file-system description object
1921 * @start_lnum: LEB number from which to start scanning
1922 * @end_lnum: LEB number at which to stop scanning
1923 * @scan_cb: callback function called for each lprops
1924 * @data: data to be passed to the callback function
1925 *
1926 * This function returns %0 on success and a negative error code on failure.
1927 */
1928int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
1929			  ubifs_lpt_scan_callback scan_cb, void *data)
1930{
1931	int err = 0, i, h, iip, shft;
1932	struct ubifs_nnode *nnode;
1933	struct ubifs_pnode *pnode;
1934	struct lpt_scan_node *path;
1935
1936	if (start_lnum == -1) {
1937		start_lnum = end_lnum + 1;
1938		if (start_lnum >= c->leb_cnt)
1939			start_lnum = c->main_first;
1940	}
1941
1942	ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
1943	ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
1944
1945	if (!c->nroot) {
1946		err = ubifs_read_nnode(c, NULL, 0);
1947		if (err)
1948			return err;
1949	}
1950
1951	path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
1952		       GFP_NOFS);
1953	if (!path)
1954		return -ENOMEM;
1955
1956	path[0].ptr.nnode = c->nroot;
1957	path[0].in_tree = 1;
1958again:
1959	/* Descend to the pnode containing start_lnum */
1960	nnode = c->nroot;
1961	i = start_lnum - c->main_first;
1962	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1963	for (h = 1; h < c->lpt_hght; h++) {
1964		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1965		shft -= UBIFS_LPT_FANOUT_SHIFT;
1966		nnode = scan_get_nnode(c, path + h, nnode, iip);
1967		if (IS_ERR(nnode)) {
1968			err = PTR_ERR(nnode);
1969			goto out;
1970		}
1971	}
1972	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1973	pnode = scan_get_pnode(c, path + h, nnode, iip);
1974	if (IS_ERR(pnode)) {
1975		err = PTR_ERR(pnode);
1976		goto out;
1977	}
1978	iip = (i & (UBIFS_LPT_FANOUT - 1));
1979
1980	/* Loop for each lprops */
1981	while (1) {
1982		struct ubifs_lprops *lprops = &pnode->lprops[iip];
1983		int ret, lnum = lprops->lnum;
1984
1985		ret = scan_cb(c, lprops, path[h].in_tree, data);
1986		if (ret < 0) {
1987			err = ret;
1988			goto out;
1989		}
1990		if (ret & LPT_SCAN_ADD) {
1991			/* Add all the nodes in path to the tree in memory */
1992			for (h = 1; h < c->lpt_hght; h++) {
1993				const size_t sz = sizeof(struct ubifs_nnode);
1994				struct ubifs_nnode *parent;
1995
1996				if (path[h].in_tree)
1997					continue;
1998				nnode = kmemdup(&path[h].nnode, sz, GFP_NOFS);
1999				if (!nnode) {
2000					err = -ENOMEM;
2001					goto out;
2002				}
2003				parent = nnode->parent;
2004				parent->nbranch[nnode->iip].nnode = nnode;
2005				path[h].ptr.nnode = nnode;
2006				path[h].in_tree = 1;
2007				path[h + 1].cnode.parent = nnode;
2008			}
2009			if (path[h].in_tree)
2010				ubifs_ensure_cat(c, lprops);
2011			else {
2012				const size_t sz = sizeof(struct ubifs_pnode);
2013				struct ubifs_nnode *parent;
2014
2015				pnode = kmemdup(&path[h].pnode, sz, GFP_NOFS);
2016				if (!pnode) {
2017					err = -ENOMEM;
2018					goto out;
2019				}
2020				parent = pnode->parent;
2021				parent->nbranch[pnode->iip].pnode = pnode;
2022				path[h].ptr.pnode = pnode;
2023				path[h].in_tree = 1;
2024				update_cats(c, pnode);
2025				c->pnodes_have += 1;
2026			}
2027			err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)
2028						  c->nroot, 0, 0);
2029			if (err)
2030				goto out;
2031			err = dbg_check_cats(c);
2032			if (err)
2033				goto out;
2034		}
2035		if (ret & LPT_SCAN_STOP) {
2036			err = 0;
2037			break;
2038		}
2039		/* Get the next lprops */
2040		if (lnum == end_lnum) {
2041			/*
2042			 * We got to the end without finding what we were
2043			 * looking for
2044			 */
2045			err = -ENOSPC;
2046			goto out;
2047		}
2048		if (lnum + 1 >= c->leb_cnt) {
2049			/* Wrap-around to the beginning */
2050			start_lnum = c->main_first;
2051			goto again;
2052		}
2053		if (iip + 1 < UBIFS_LPT_FANOUT) {
2054			/* Next lprops is in the same pnode */
2055			iip += 1;
2056			continue;
2057		}
2058		/* We need to get the next pnode. Go up until we can go right */
2059		iip = pnode->iip;
2060		while (1) {
2061			h -= 1;
2062			ubifs_assert(h >= 0);
2063			nnode = path[h].ptr.nnode;
2064			if (iip + 1 < UBIFS_LPT_FANOUT)
2065				break;
2066			iip = nnode->iip;
2067		}
2068		/* Go right */
2069		iip += 1;
2070		/* Descend to the pnode */
2071		h += 1;
2072		for (; h < c->lpt_hght; h++) {
2073			nnode = scan_get_nnode(c, path + h, nnode, iip);
2074			if (IS_ERR(nnode)) {
2075				err = PTR_ERR(nnode);
2076				goto out;
2077			}
2078			iip = 0;
2079		}
2080		pnode = scan_get_pnode(c, path + h, nnode, iip);
2081		if (IS_ERR(pnode)) {
2082			err = PTR_ERR(pnode);
2083			goto out;
2084		}
2085		iip = 0;
2086	}
2087out:
2088	kfree(path);
2089	return err;
2090}
2091
2092/**
2093 * dbg_chk_pnode - check a pnode.
2094 * @c: the UBIFS file-system description object
2095 * @pnode: pnode to check
2096 * @col: pnode column
2097 *
2098 * This function returns %0 on success and a negative error code on failure.
2099 */
2100static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
2101			 int col)
2102{
2103	int i;
2104
2105	if (pnode->num != col) {
2106		ubifs_err(c, "pnode num %d expected %d parent num %d iip %d",
2107			  pnode->num, col, pnode->parent->num, pnode->iip);
2108		return -EINVAL;
2109	}
2110	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2111		struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
2112		int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
2113			   c->main_first;
2114		int found, cat = lprops->flags & LPROPS_CAT_MASK;
2115		struct ubifs_lpt_heap *heap;
2116		struct list_head *list = NULL;
2117
2118		if (lnum >= c->leb_cnt)
2119			continue;
2120		if (lprops->lnum != lnum) {
2121			ubifs_err(c, "bad LEB number %d expected %d",
2122				  lprops->lnum, lnum);
2123			return -EINVAL;
2124		}
2125		if (lprops->flags & LPROPS_TAKEN) {
2126			if (cat != LPROPS_UNCAT) {
2127				ubifs_err(c, "LEB %d taken but not uncat %d",
2128					  lprops->lnum, cat);
2129				return -EINVAL;
2130			}
2131			continue;
2132		}
2133		if (lprops->flags & LPROPS_INDEX) {
2134			switch (cat) {
2135			case LPROPS_UNCAT:
2136			case LPROPS_DIRTY_IDX:
2137			case LPROPS_FRDI_IDX:
2138				break;
2139			default:
2140				ubifs_err(c, "LEB %d index but cat %d",
2141					  lprops->lnum, cat);
2142				return -EINVAL;
2143			}
2144		} else {
2145			switch (cat) {
2146			case LPROPS_UNCAT:
2147			case LPROPS_DIRTY:
2148			case LPROPS_FREE:
2149			case LPROPS_EMPTY:
2150			case LPROPS_FREEABLE:
2151				break;
2152			default:
2153				ubifs_err(c, "LEB %d not index but cat %d",
2154					  lprops->lnum, cat);
2155				return -EINVAL;
2156			}
2157		}
2158		switch (cat) {
2159		case LPROPS_UNCAT:
2160			list = &c->uncat_list;
2161			break;
2162		case LPROPS_EMPTY:
2163			list = &c->empty_list;
2164			break;
2165		case LPROPS_FREEABLE:
2166			list = &c->freeable_list;
2167			break;
2168		case LPROPS_FRDI_IDX:
2169			list = &c->frdi_idx_list;
2170			break;
2171		}
2172		found = 0;
2173		switch (cat) {
2174		case LPROPS_DIRTY:
2175		case LPROPS_DIRTY_IDX:
2176		case LPROPS_FREE:
2177			heap = &c->lpt_heap[cat - 1];
2178			if (lprops->hpos < heap->cnt &&
2179			    heap->arr[lprops->hpos] == lprops)
2180				found = 1;
2181			break;
2182		case LPROPS_UNCAT:
2183		case LPROPS_EMPTY:
2184		case LPROPS_FREEABLE:
2185		case LPROPS_FRDI_IDX:
2186			list_for_each_entry(lp, list, list)
2187				if (lprops == lp) {
2188					found = 1;
2189					break;
2190				}
2191			break;
2192		}
2193		if (!found) {
2194			ubifs_err(c, "LEB %d cat %d not found in cat heap/list",
2195				  lprops->lnum, cat);
2196			return -EINVAL;
2197		}
2198		switch (cat) {
2199		case LPROPS_EMPTY:
2200			if (lprops->free != c->leb_size) {
2201				ubifs_err(c, "LEB %d cat %d free %d dirty %d",
2202					  lprops->lnum, cat, lprops->free,
2203					  lprops->dirty);
2204				return -EINVAL;
2205			}
2206			break;
2207		case LPROPS_FREEABLE:
2208		case LPROPS_FRDI_IDX:
2209			if (lprops->free + lprops->dirty != c->leb_size) {
2210				ubifs_err(c, "LEB %d cat %d free %d dirty %d",
2211					  lprops->lnum, cat, lprops->free,
2212					  lprops->dirty);
2213				return -EINVAL;
2214			}
2215			break;
2216		}
2217	}
2218	return 0;
2219}
2220
2221/**
2222 * dbg_check_lpt_nodes - check nnodes and pnodes.
2223 * @c: the UBIFS file-system description object
2224 * @cnode: next cnode (nnode or pnode) to check
2225 * @row: row of cnode (root is zero)
2226 * @col: column of cnode (leftmost is zero)
2227 *
2228 * This function returns %0 on success and a negative error code on failure.
2229 */
2230int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
2231			int row, int col)
2232{
2233	struct ubifs_nnode *nnode, *nn;
2234	struct ubifs_cnode *cn;
2235	int num, iip = 0, err;
2236
2237	if (!dbg_is_chk_lprops(c))
2238		return 0;
2239
2240	while (cnode) {
2241		ubifs_assert(row >= 0);
2242		nnode = cnode->parent;
2243		if (cnode->level) {
2244			/* cnode is a nnode */
2245			num = calc_nnode_num(row, col);
2246			if (cnode->num != num) {
2247				ubifs_err(c, "nnode num %d expected %d parent num %d iip %d",
2248					  cnode->num, num,
2249					  (nnode ? nnode->num : 0), cnode->iip);
2250				return -EINVAL;
2251			}
2252			nn = (struct ubifs_nnode *)cnode;
2253			while (iip < UBIFS_LPT_FANOUT) {
2254				cn = nn->nbranch[iip].cnode;
2255				if (cn) {
2256					/* Go down */
2257					row += 1;
2258					col <<= UBIFS_LPT_FANOUT_SHIFT;
2259					col += iip;
2260					iip = 0;
2261					cnode = cn;
2262					break;
2263				}
2264				/* Go right */
2265				iip += 1;
2266			}
2267			if (iip < UBIFS_LPT_FANOUT)
2268				continue;
2269		} else {
2270			struct ubifs_pnode *pnode;
2271
2272			/* cnode is a pnode */
2273			pnode = (struct ubifs_pnode *)cnode;
2274			err = dbg_chk_pnode(c, pnode, col);
2275			if (err)
2276				return err;
2277		}
2278		/* Go up and to the right */
2279		row -= 1;
2280		col >>= UBIFS_LPT_FANOUT_SHIFT;
2281		iip = cnode->iip + 1;
2282		cnode = (struct ubifs_cnode *)nnode;
2283	}
2284	return 0;
2285}
2286