blob: dc9f27e9d61be5b8586af0025d95a0dc305afecc [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file implements the LEB properties tree (LPT) area. The LPT area
25 * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
26 * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
27 * between the log and the orphan area.
28 *
29 * The LPT area is like a miniature self-contained file system. It is required
30 * that it never runs out of space, is fast to access and update, and scales
31 * logarithmically. The LEB properties tree is implemented as a wandering tree
32 * much like the TNC, and the LPT area has its own garbage collection.
33 *
34 * The LPT has two slightly different forms called the "small model" and the
35 * "big model". The small model is used when the entire LEB properties table
36 * can be written into a single eraseblock. In that case, garbage collection
37 * consists of just writing the whole table, which therefore makes all other
38 * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
Artem Bityutskiy45e12d92008-10-31 11:42:18 +020039 * selected for garbage collection, which consists of marking the clean nodes in
Artem Bityutskiy1e517642008-07-14 19:08:37 +030040 * that LEB as dirty, and then only the dirty nodes are written out. Also, in
41 * the case of the big model, a table of LEB numbers is saved so that the entire
42 * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
43 * mounted.
44 */
45
Artem Bityutskiy1e517642008-07-14 19:08:37 +030046#include "ubifs.h"
Artem Bityutskiy4d61db42008-12-18 14:06:51 +020047#include <linux/crc16.h>
48#include <linux/math64.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090049#include <linux/slab.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030050
51/**
52 * do_calc_lpt_geom - calculate sizes for the LPT area.
53 * @c: the UBIFS file-system description object
54 *
55 * Calculate the sizes of LPT bit fields, nodes, and tree, based on the
56 * properties of the flash and whether LPT is "big" (c->big_lpt).
57 */
58static void do_calc_lpt_geom(struct ubifs_info *c)
59{
60 int i, n, bits, per_leb_wastage, max_pnode_cnt;
61 long long sz, tot_wastage;
62
63 n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
64 max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
65
66 c->lpt_hght = 1;
67 n = UBIFS_LPT_FANOUT;
68 while (n < max_pnode_cnt) {
69 c->lpt_hght += 1;
70 n <<= UBIFS_LPT_FANOUT_SHIFT;
71 }
72
73 c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
74
75 n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
76 c->nnode_cnt = n;
77 for (i = 1; i < c->lpt_hght; i++) {
78 n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
79 c->nnode_cnt += n;
80 }
81
82 c->space_bits = fls(c->leb_size) - 3;
83 c->lpt_lnum_bits = fls(c->lpt_lebs);
84 c->lpt_offs_bits = fls(c->leb_size - 1);
85 c->lpt_spc_bits = fls(c->leb_size);
86
87 n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
88 c->pcnt_bits = fls(n - 1);
89
90 c->lnum_bits = fls(c->max_leb_cnt - 1);
91
92 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
93 (c->big_lpt ? c->pcnt_bits : 0) +
94 (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
95 c->pnode_sz = (bits + 7) / 8;
96
97 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
98 (c->big_lpt ? c->pcnt_bits : 0) +
99 (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
100 c->nnode_sz = (bits + 7) / 8;
101
102 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
103 c->lpt_lebs * c->lpt_spc_bits * 2;
104 c->ltab_sz = (bits + 7) / 8;
105
106 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
107 c->lnum_bits * c->lsave_cnt;
108 c->lsave_sz = (bits + 7) / 8;
109
110 /* Calculate the minimum LPT size */
111 c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
112 c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
113 c->lpt_sz += c->ltab_sz;
Adrian Hunter73944a62008-09-12 18:13:31 +0300114 if (c->big_lpt)
115 c->lpt_sz += c->lsave_sz;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300116
117 /* Add wastage */
118 sz = c->lpt_sz;
119 per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
120 sz += per_leb_wastage;
121 tot_wastage = per_leb_wastage;
122 while (sz > c->leb_size) {
123 sz += per_leb_wastage;
124 sz -= c->leb_size;
125 tot_wastage += per_leb_wastage;
126 }
127 tot_wastage += ALIGN(sz, c->min_io_size) - sz;
128 c->lpt_sz += tot_wastage;
129}
130
131/**
132 * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
133 * @c: the UBIFS file-system description object
134 *
135 * This function returns %0 on success and a negative error code on failure.
136 */
137int ubifs_calc_lpt_geom(struct ubifs_info *c)
138{
139 int lebs_needed;
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200140 long long sz;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300141
142 do_calc_lpt_geom(c);
143
144 /* Verify that lpt_lebs is big enough */
145 sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200146 lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300147 if (lebs_needed > c->lpt_lebs) {
Sheng Yong235c3622015-03-20 10:39:42 +0000148 ubifs_err(c, "too few LPT LEBs");
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300149 return -EINVAL;
150 }
151
152 /* Verify that ltab fits in a single LEB (since ltab is a single node */
153 if (c->ltab_sz > c->leb_size) {
Sheng Yong235c3622015-03-20 10:39:42 +0000154 ubifs_err(c, "LPT ltab too big");
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300155 return -EINVAL;
156 }
157
158 c->check_lpt_free = c->big_lpt;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300159 return 0;
160}
161
162/**
163 * calc_dflt_lpt_geom - calculate default LPT geometry.
164 * @c: the UBIFS file-system description object
165 * @main_lebs: number of main area LEBs is passed and returned here
166 * @big_lpt: whether the LPT area is "big" is returned here
167 *
168 * The size of the LPT area depends on parameters that themselves are dependent
169 * on the size of the LPT area. This function, successively recalculates the LPT
170 * area geometry until the parameters and resultant geometry are consistent.
171 *
172 * This function returns %0 on success and a negative error code on failure.
173 */
174static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
175 int *big_lpt)
176{
177 int i, lebs_needed;
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200178 long long sz;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300179
180 /* Start by assuming the minimum number of LPT LEBs */
181 c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
182 c->main_lebs = *main_lebs - c->lpt_lebs;
183 if (c->main_lebs <= 0)
184 return -EINVAL;
185
186 /* And assume we will use the small LPT model */
187 c->big_lpt = 0;
188
189 /*
190 * Calculate the geometry based on assumptions above and then see if it
191 * makes sense
192 */
193 do_calc_lpt_geom(c);
194
195 /* Small LPT model must have lpt_sz < leb_size */
196 if (c->lpt_sz > c->leb_size) {
197 /* Nope, so try again using big LPT model */
198 c->big_lpt = 1;
199 do_calc_lpt_geom(c);
200 }
201
202 /* Now check there are enough LPT LEBs */
203 for (i = 0; i < 64 ; i++) {
204 sz = c->lpt_sz * 4; /* Allow 4 times the size */
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200205 lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300206 if (lebs_needed > c->lpt_lebs) {
207 /* Not enough LPT LEBs so try again with more */
208 c->lpt_lebs = lebs_needed;
209 c->main_lebs = *main_lebs - c->lpt_lebs;
210 if (c->main_lebs <= 0)
211 return -EINVAL;
212 do_calc_lpt_geom(c);
213 continue;
214 }
215 if (c->ltab_sz > c->leb_size) {
Sheng Yong235c3622015-03-20 10:39:42 +0000216 ubifs_err(c, "LPT ltab too big");
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300217 return -EINVAL;
218 }
219 *main_lebs = c->main_lebs;
220 *big_lpt = c->big_lpt;
221 return 0;
222 }
223 return -EINVAL;
224}
225
226/**
227 * pack_bits - pack bit fields end-to-end.
228 * @addr: address at which to pack (passed and next address returned)
229 * @pos: bit position at which to pack (passed and next position returned)
230 * @val: value to pack
231 * @nrbits: number of bits of value to pack (1-32)
232 */
233static void pack_bits(uint8_t **addr, int *pos, uint32_t val, int nrbits)
234{
235 uint8_t *p = *addr;
236 int b = *pos;
237
238 ubifs_assert(nrbits > 0);
239 ubifs_assert(nrbits <= 32);
240 ubifs_assert(*pos >= 0);
241 ubifs_assert(*pos < 8);
242 ubifs_assert((val >> nrbits) == 0 || nrbits == 32);
243 if (b) {
244 *p |= ((uint8_t)val) << b;
245 nrbits += b;
246 if (nrbits > 8) {
247 *++p = (uint8_t)(val >>= (8 - b));
248 if (nrbits > 16) {
249 *++p = (uint8_t)(val >>= 8);
250 if (nrbits > 24) {
251 *++p = (uint8_t)(val >>= 8);
252 if (nrbits > 32)
253 *++p = (uint8_t)(val >>= 8);
254 }
255 }
256 }
257 } else {
258 *p = (uint8_t)val;
259 if (nrbits > 8) {
260 *++p = (uint8_t)(val >>= 8);
261 if (nrbits > 16) {
262 *++p = (uint8_t)(val >>= 8);
263 if (nrbits > 24)
264 *++p = (uint8_t)(val >>= 8);
265 }
266 }
267 }
268 b = nrbits & 7;
269 if (b == 0)
270 p++;
271 *addr = p;
272 *pos = b;
273}
274
275/**
276 * ubifs_unpack_bits - unpack bit fields.
277 * @addr: address at which to unpack (passed and next address returned)
278 * @pos: bit position at which to unpack (passed and next position returned)
279 * @nrbits: number of bits of value to unpack (1-32)
280 *
281 * This functions returns the value unpacked.
282 */
283uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
284{
285 const int k = 32 - nrbits;
286 uint8_t *p = *addr;
287 int b = *pos;
Adrian Hunter727d2dc2008-10-17 16:52:10 +0300288 uint32_t uninitialized_var(val);
289 const int bytes = (nrbits + b + 7) >> 3;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300290
291 ubifs_assert(nrbits > 0);
292 ubifs_assert(nrbits <= 32);
293 ubifs_assert(*pos >= 0);
294 ubifs_assert(*pos < 8);
295 if (b) {
Adrian Hunter727d2dc2008-10-17 16:52:10 +0300296 switch (bytes) {
297 case 2:
298 val = p[1];
299 break;
300 case 3:
301 val = p[1] | ((uint32_t)p[2] << 8);
302 break;
303 case 4:
304 val = p[1] | ((uint32_t)p[2] << 8) |
305 ((uint32_t)p[3] << 16);
306 break;
307 case 5:
308 val = p[1] | ((uint32_t)p[2] << 8) |
309 ((uint32_t)p[3] << 16) |
310 ((uint32_t)p[4] << 24);
311 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300312 val <<= (8 - b);
313 val |= *p >> b;
314 nrbits += b;
Adrian Hunter727d2dc2008-10-17 16:52:10 +0300315 } else {
316 switch (bytes) {
317 case 1:
318 val = p[0];
319 break;
320 case 2:
321 val = p[0] | ((uint32_t)p[1] << 8);
322 break;
323 case 3:
324 val = p[0] | ((uint32_t)p[1] << 8) |
325 ((uint32_t)p[2] << 16);
326 break;
327 case 4:
328 val = p[0] | ((uint32_t)p[1] << 8) |
329 ((uint32_t)p[2] << 16) |
330 ((uint32_t)p[3] << 24);
331 break;
332 }
333 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300334 val <<= k;
335 val >>= k;
336 b = nrbits & 7;
Adrian Hunter727d2dc2008-10-17 16:52:10 +0300337 p += nrbits >> 3;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300338 *addr = p;
339 *pos = b;
340 ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
341 return val;
342}
343
344/**
345 * ubifs_pack_pnode - pack all the bit fields of a pnode.
346 * @c: UBIFS file-system description object
347 * @buf: buffer into which to pack
348 * @pnode: pnode to pack
349 */
350void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
351 struct ubifs_pnode *pnode)
352{
353 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
354 int i, pos = 0;
355 uint16_t crc;
356
357 pack_bits(&addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
358 if (c->big_lpt)
359 pack_bits(&addr, &pos, pnode->num, c->pcnt_bits);
360 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
361 pack_bits(&addr, &pos, pnode->lprops[i].free >> 3,
362 c->space_bits);
363 pack_bits(&addr, &pos, pnode->lprops[i].dirty >> 3,
364 c->space_bits);
365 if (pnode->lprops[i].flags & LPROPS_INDEX)
366 pack_bits(&addr, &pos, 1, 1);
367 else
368 pack_bits(&addr, &pos, 0, 1);
369 }
370 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
371 c->pnode_sz - UBIFS_LPT_CRC_BYTES);
372 addr = buf;
373 pos = 0;
374 pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
375}
376
377/**
378 * ubifs_pack_nnode - pack all the bit fields of a nnode.
379 * @c: UBIFS file-system description object
380 * @buf: buffer into which to pack
381 * @nnode: nnode to pack
382 */
383void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
384 struct ubifs_nnode *nnode)
385{
386 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
387 int i, pos = 0;
388 uint16_t crc;
389
390 pack_bits(&addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
391 if (c->big_lpt)
392 pack_bits(&addr, &pos, nnode->num, c->pcnt_bits);
393 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
394 int lnum = nnode->nbranch[i].lnum;
395
396 if (lnum == 0)
397 lnum = c->lpt_last + 1;
398 pack_bits(&addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
399 pack_bits(&addr, &pos, nnode->nbranch[i].offs,
400 c->lpt_offs_bits);
401 }
402 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
403 c->nnode_sz - UBIFS_LPT_CRC_BYTES);
404 addr = buf;
405 pos = 0;
406 pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
407}
408
409/**
410 * ubifs_pack_ltab - pack the LPT's own lprops table.
411 * @c: UBIFS file-system description object
412 * @buf: buffer into which to pack
413 * @ltab: LPT's own lprops table to pack
414 */
415void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
416 struct ubifs_lpt_lprops *ltab)
417{
418 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
419 int i, pos = 0;
420 uint16_t crc;
421
422 pack_bits(&addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
423 for (i = 0; i < c->lpt_lebs; i++) {
424 pack_bits(&addr, &pos, ltab[i].free, c->lpt_spc_bits);
425 pack_bits(&addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
426 }
427 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
428 c->ltab_sz - UBIFS_LPT_CRC_BYTES);
429 addr = buf;
430 pos = 0;
431 pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
432}
433
434/**
435 * ubifs_pack_lsave - pack the LPT's save table.
436 * @c: UBIFS file-system description object
437 * @buf: buffer into which to pack
438 * @lsave: LPT's save table to pack
439 */
440void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
441{
442 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
443 int i, pos = 0;
444 uint16_t crc;
445
446 pack_bits(&addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
447 for (i = 0; i < c->lsave_cnt; i++)
448 pack_bits(&addr, &pos, lsave[i], c->lnum_bits);
449 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
450 c->lsave_sz - UBIFS_LPT_CRC_BYTES);
451 addr = buf;
452 pos = 0;
453 pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
454}
455
456/**
457 * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
458 * @c: UBIFS file-system description object
459 * @lnum: LEB number to which to add dirty space
460 * @dirty: amount of dirty space to add
461 */
462void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
463{
464 if (!dirty || !lnum)
465 return;
466 dbg_lp("LEB %d add %d to %d",
467 lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
468 ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
469 c->ltab[lnum - c->lpt_first].dirty += dirty;
470}
471
472/**
473 * set_ltab - set LPT LEB properties.
474 * @c: UBIFS file-system description object
475 * @lnum: LEB number
476 * @free: amount of free space
477 * @dirty: amount of dirty space
478 */
479static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
480{
481 dbg_lp("LEB %d free %d dirty %d to %d %d",
482 lnum, c->ltab[lnum - c->lpt_first].free,
483 c->ltab[lnum - c->lpt_first].dirty, free, dirty);
484 ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
485 c->ltab[lnum - c->lpt_first].free = free;
486 c->ltab[lnum - c->lpt_first].dirty = dirty;
487}
488
489/**
490 * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
491 * @c: UBIFS file-system description object
492 * @nnode: nnode for which to add dirt
493 */
494void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
495{
496 struct ubifs_nnode *np = nnode->parent;
497
498 if (np)
499 ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
500 c->nnode_sz);
501 else {
502 ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
503 if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
504 c->lpt_drty_flgs |= LTAB_DIRTY;
505 ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
506 }
507 }
508}
509
510/**
511 * add_pnode_dirt - add dirty space to LPT LEB properties.
512 * @c: UBIFS file-system description object
513 * @pnode: pnode for which to add dirt
514 */
515static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
516{
517 ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
518 c->pnode_sz);
519}
520
521/**
522 * calc_nnode_num - calculate nnode number.
523 * @row: the row in the tree (root is zero)
524 * @col: the column in the row (leftmost is zero)
525 *
526 * The nnode number is a number that uniquely identifies a nnode and can be used
527 * easily to traverse the tree from the root to that nnode.
528 *
529 * This function calculates and returns the nnode number for the nnode at @row
530 * and @col.
531 */
532static int calc_nnode_num(int row, int col)
533{
534 int num, bits;
535
536 num = 1;
537 while (row--) {
538 bits = (col & (UBIFS_LPT_FANOUT - 1));
539 col >>= UBIFS_LPT_FANOUT_SHIFT;
540 num <<= UBIFS_LPT_FANOUT_SHIFT;
541 num |= bits;
542 }
543 return num;
544}
545
546/**
547 * calc_nnode_num_from_parent - calculate nnode number.
548 * @c: UBIFS file-system description object
549 * @parent: parent nnode
550 * @iip: index in parent
551 *
552 * The nnode number is a number that uniquely identifies a nnode and can be used
553 * easily to traverse the tree from the root to that nnode.
554 *
555 * This function calculates and returns the nnode number based on the parent's
556 * nnode number and the index in parent.
557 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200558static int calc_nnode_num_from_parent(const struct ubifs_info *c,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300559 struct ubifs_nnode *parent, int iip)
560{
561 int num, shft;
562
563 if (!parent)
564 return 1;
565 shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
566 num = parent->num ^ (1 << shft);
567 num |= (UBIFS_LPT_FANOUT + iip) << shft;
568 return num;
569}
570
571/**
572 * calc_pnode_num_from_parent - calculate pnode number.
573 * @c: UBIFS file-system description object
574 * @parent: parent nnode
575 * @iip: index in parent
576 *
577 * The pnode number is a number that uniquely identifies a pnode and can be used
578 * easily to traverse the tree from the root to that pnode.
579 *
580 * This function calculates and returns the pnode number based on the parent's
581 * nnode number and the index in parent.
582 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200583static int calc_pnode_num_from_parent(const struct ubifs_info *c,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300584 struct ubifs_nnode *parent, int iip)
585{
586 int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
587
588 for (i = 0; i < n; i++) {
589 num <<= UBIFS_LPT_FANOUT_SHIFT;
590 num |= pnum & (UBIFS_LPT_FANOUT - 1);
591 pnum >>= UBIFS_LPT_FANOUT_SHIFT;
592 }
593 num <<= UBIFS_LPT_FANOUT_SHIFT;
594 num |= iip;
595 return num;
596}
597
598/**
599 * ubifs_create_dflt_lpt - create default LPT.
600 * @c: UBIFS file-system description object
601 * @main_lebs: number of main area LEBs is passed and returned here
602 * @lpt_first: LEB number of first LPT LEB
603 * @lpt_lebs: number of LEBs for LPT is passed and returned here
604 * @big_lpt: use big LPT model is passed and returned here
605 *
606 * This function returns %0 on success and a negative error code on failure.
607 */
608int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
609 int *lpt_lebs, int *big_lpt)
610{
611 int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
612 int blnum, boffs, bsz, bcnt;
613 struct ubifs_pnode *pnode = NULL;
614 struct ubifs_nnode *nnode = NULL;
615 void *buf = NULL, *p;
616 struct ubifs_lpt_lprops *ltab = NULL;
617 int *lsave = NULL;
618
619 err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
620 if (err)
621 return err;
622 *lpt_lebs = c->lpt_lebs;
623
624 /* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
625 c->lpt_first = lpt_first;
626 /* Needed by 'set_ltab()' */
627 c->lpt_last = lpt_first + c->lpt_lebs - 1;
628 /* Needed by 'ubifs_pack_lsave()' */
629 c->main_first = c->leb_cnt - *main_lebs;
630
631 lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_KERNEL);
632 pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
633 nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
634 buf = vmalloc(c->leb_size);
635 ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
636 if (!pnode || !nnode || !buf || !ltab || !lsave) {
637 err = -ENOMEM;
638 goto out;
639 }
640
641 ubifs_assert(!c->ltab);
642 c->ltab = ltab; /* Needed by set_ltab */
643
644 /* Initialize LPT's own lprops */
645 for (i = 0; i < c->lpt_lebs; i++) {
646 ltab[i].free = c->leb_size;
647 ltab[i].dirty = 0;
648 ltab[i].tgc = 0;
649 ltab[i].cmt = 0;
650 }
651
652 lnum = lpt_first;
653 p = buf;
654 /* Number of leaf nodes (pnodes) */
655 cnt = c->pnode_cnt;
656
657 /*
658 * The first pnode contains the LEB properties for the LEBs that contain
659 * the root inode node and the root index node of the index tree.
660 */
661 node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
662 iopos = ALIGN(node_sz, c->min_io_size);
663 pnode->lprops[0].free = c->leb_size - iopos;
664 pnode->lprops[0].dirty = iopos - node_sz;
665 pnode->lprops[0].flags = LPROPS_INDEX;
666
667 node_sz = UBIFS_INO_NODE_SZ;
668 iopos = ALIGN(node_sz, c->min_io_size);
669 pnode->lprops[1].free = c->leb_size - iopos;
670 pnode->lprops[1].dirty = iopos - node_sz;
671
672 for (i = 2; i < UBIFS_LPT_FANOUT; i++)
673 pnode->lprops[i].free = c->leb_size;
674
675 /* Add first pnode */
676 ubifs_pack_pnode(c, p, pnode);
677 p += c->pnode_sz;
678 len = c->pnode_sz;
679 pnode->num += 1;
680
681 /* Reset pnode values for remaining pnodes */
682 pnode->lprops[0].free = c->leb_size;
683 pnode->lprops[0].dirty = 0;
684 pnode->lprops[0].flags = 0;
685
686 pnode->lprops[1].free = c->leb_size;
687 pnode->lprops[1].dirty = 0;
688
689 /*
690 * To calculate the internal node branches, we keep information about
691 * the level below.
692 */
693 blnum = lnum; /* LEB number of level below */
694 boffs = 0; /* Offset of level below */
695 bcnt = cnt; /* Number of nodes in level below */
696 bsz = c->pnode_sz; /* Size of nodes in level below */
697
698 /* Add all remaining pnodes */
699 for (i = 1; i < cnt; i++) {
700 if (len + c->pnode_sz > c->leb_size) {
701 alen = ALIGN(len, c->min_io_size);
702 set_ltab(c, lnum, c->leb_size - alen, alen - len);
703 memset(p, 0xff, alen - len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200704 err = ubifs_leb_change(c, lnum++, buf, alen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300705 if (err)
706 goto out;
707 p = buf;
708 len = 0;
709 }
710 ubifs_pack_pnode(c, p, pnode);
711 p += c->pnode_sz;
712 len += c->pnode_sz;
713 /*
714 * pnodes are simply numbered left to right starting at zero,
715 * which means the pnode number can be used easily to traverse
716 * down the tree to the corresponding pnode.
717 */
718 pnode->num += 1;
719 }
720
721 row = 0;
722 for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
723 row += 1;
724 /* Add all nnodes, one level at a time */
725 while (1) {
726 /* Number of internal nodes (nnodes) at next level */
727 cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
728 for (i = 0; i < cnt; i++) {
729 if (len + c->nnode_sz > c->leb_size) {
730 alen = ALIGN(len, c->min_io_size);
731 set_ltab(c, lnum, c->leb_size - alen,
732 alen - len);
733 memset(p, 0xff, alen - len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200734 err = ubifs_leb_change(c, lnum++, buf, alen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300735 if (err)
736 goto out;
737 p = buf;
738 len = 0;
739 }
740 /* Only 1 nnode at this level, so it is the root */
741 if (cnt == 1) {
742 c->lpt_lnum = lnum;
743 c->lpt_offs = len;
744 }
745 /* Set branches to the level below */
746 for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
747 if (bcnt) {
748 if (boffs + bsz > c->leb_size) {
749 blnum += 1;
750 boffs = 0;
751 }
752 nnode->nbranch[j].lnum = blnum;
753 nnode->nbranch[j].offs = boffs;
754 boffs += bsz;
755 bcnt--;
756 } else {
757 nnode->nbranch[j].lnum = 0;
758 nnode->nbranch[j].offs = 0;
759 }
760 }
761 nnode->num = calc_nnode_num(row, i);
762 ubifs_pack_nnode(c, p, nnode);
763 p += c->nnode_sz;
764 len += c->nnode_sz;
765 }
766 /* Only 1 nnode at this level, so it is the root */
767 if (cnt == 1)
768 break;
769 /* Update the information about the level below */
770 bcnt = cnt;
771 bsz = c->nnode_sz;
772 row -= 1;
773 }
774
775 if (*big_lpt) {
776 /* Need to add LPT's save table */
777 if (len + c->lsave_sz > c->leb_size) {
778 alen = ALIGN(len, c->min_io_size);
779 set_ltab(c, lnum, c->leb_size - alen, alen - len);
780 memset(p, 0xff, alen - len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200781 err = ubifs_leb_change(c, lnum++, buf, alen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300782 if (err)
783 goto out;
784 p = buf;
785 len = 0;
786 }
787
788 c->lsave_lnum = lnum;
789 c->lsave_offs = len;
790
791 for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
792 lsave[i] = c->main_first + i;
793 for (; i < c->lsave_cnt; i++)
794 lsave[i] = c->main_first;
795
796 ubifs_pack_lsave(c, p, lsave);
797 p += c->lsave_sz;
798 len += c->lsave_sz;
799 }
800
801 /* Need to add LPT's own LEB properties table */
802 if (len + c->ltab_sz > c->leb_size) {
803 alen = ALIGN(len, c->min_io_size);
804 set_ltab(c, lnum, c->leb_size - alen, alen - len);
805 memset(p, 0xff, alen - len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200806 err = ubifs_leb_change(c, lnum++, buf, alen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300807 if (err)
808 goto out;
809 p = buf;
810 len = 0;
811 }
812
813 c->ltab_lnum = lnum;
814 c->ltab_offs = len;
815
816 /* Update ltab before packing it */
817 len += c->ltab_sz;
818 alen = ALIGN(len, c->min_io_size);
819 set_ltab(c, lnum, c->leb_size - alen, alen - len);
820
821 ubifs_pack_ltab(c, p, ltab);
822 p += c->ltab_sz;
823
824 /* Write remaining buffer */
825 memset(p, 0xff, alen - len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200826 err = ubifs_leb_change(c, lnum, buf, alen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300827 if (err)
828 goto out;
829
830 c->nhead_lnum = lnum;
831 c->nhead_offs = ALIGN(len, c->min_io_size);
832
833 dbg_lp("space_bits %d", c->space_bits);
834 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
835 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
836 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
837 dbg_lp("pcnt_bits %d", c->pcnt_bits);
838 dbg_lp("lnum_bits %d", c->lnum_bits);
839 dbg_lp("pnode_sz %d", c->pnode_sz);
840 dbg_lp("nnode_sz %d", c->nnode_sz);
841 dbg_lp("ltab_sz %d", c->ltab_sz);
842 dbg_lp("lsave_sz %d", c->lsave_sz);
843 dbg_lp("lsave_cnt %d", c->lsave_cnt);
844 dbg_lp("lpt_hght %d", c->lpt_hght);
845 dbg_lp("big_lpt %d", c->big_lpt);
846 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
847 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
848 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
849 if (c->big_lpt)
850 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
851out:
852 c->ltab = NULL;
853 kfree(lsave);
854 vfree(ltab);
855 vfree(buf);
856 kfree(nnode);
857 kfree(pnode);
858 return err;
859}
860
861/**
862 * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
863 * @c: UBIFS file-system description object
864 * @pnode: pnode
865 *
866 * When a pnode is loaded into memory, the LEB properties it contains are added,
867 * by this function, to the LEB category lists and heaps.
868 */
869static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
870{
871 int i;
872
873 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
874 int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
875 int lnum = pnode->lprops[i].lnum;
876
877 if (!lnum)
878 return;
879 ubifs_add_to_cat(c, &pnode->lprops[i], cat);
880 }
881}
882
883/**
884 * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
885 * @c: UBIFS file-system description object
886 * @old_pnode: pnode copied
887 * @new_pnode: pnode copy
888 *
889 * During commit it is sometimes necessary to copy a pnode
890 * (see dirty_cow_pnode). When that happens, references in
891 * category lists and heaps must be replaced. This function does that.
892 */
893static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
894 struct ubifs_pnode *new_pnode)
895{
896 int i;
897
898 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
899 if (!new_pnode->lprops[i].lnum)
900 return;
901 ubifs_replace_cat(c, &old_pnode->lprops[i],
902 &new_pnode->lprops[i]);
903 }
904}
905
906/**
907 * check_lpt_crc - check LPT node crc is correct.
908 * @c: UBIFS file-system description object
909 * @buf: buffer containing node
910 * @len: length of node
911 *
912 * This function returns %0 on success and a negative error code on failure.
913 */
Sheng Yong235c3622015-03-20 10:39:42 +0000914static int check_lpt_crc(const struct ubifs_info *c, void *buf, int len)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300915{
916 int pos = 0;
917 uint8_t *addr = buf;
918 uint16_t crc, calc_crc;
919
920 crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
921 calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
922 len - UBIFS_LPT_CRC_BYTES);
923 if (crc != calc_crc) {
Sheng Yong235c3622015-03-20 10:39:42 +0000924 ubifs_err(c, "invalid crc in LPT node: crc %hx calc %hx",
925 crc, calc_crc);
Artem Bityutskiy7c46d0a2012-05-16 19:04:54 +0300926 dump_stack();
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300927 return -EINVAL;
928 }
929 return 0;
930}
931
932/**
933 * check_lpt_type - check LPT node type is correct.
934 * @c: UBIFS file-system description object
935 * @addr: address of type bit field is passed and returned updated here
936 * @pos: position of type bit field is passed and returned updated here
937 * @type: expected type
938 *
939 * This function returns %0 on success and a negative error code on failure.
940 */
Sheng Yong235c3622015-03-20 10:39:42 +0000941static int check_lpt_type(const struct ubifs_info *c, uint8_t **addr,
942 int *pos, int type)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300943{
944 int node_type;
945
946 node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
947 if (node_type != type) {
Sheng Yong235c3622015-03-20 10:39:42 +0000948 ubifs_err(c, "invalid type (%d) in LPT node type %d",
949 node_type, type);
Artem Bityutskiy7c46d0a2012-05-16 19:04:54 +0300950 dump_stack();
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300951 return -EINVAL;
952 }
953 return 0;
954}
955
956/**
957 * unpack_pnode - unpack a pnode.
958 * @c: UBIFS file-system description object
959 * @buf: buffer containing packed pnode to unpack
960 * @pnode: pnode structure to fill
961 *
962 * This function returns %0 on success and a negative error code on failure.
963 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200964static int unpack_pnode(const struct ubifs_info *c, void *buf,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300965 struct ubifs_pnode *pnode)
966{
967 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
968 int i, pos = 0, err;
969
Sheng Yong235c3622015-03-20 10:39:42 +0000970 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_PNODE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300971 if (err)
972 return err;
973 if (c->big_lpt)
974 pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
975 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
976 struct ubifs_lprops * const lprops = &pnode->lprops[i];
977
978 lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
979 lprops->free <<= 3;
980 lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
981 lprops->dirty <<= 3;
982
983 if (ubifs_unpack_bits(&addr, &pos, 1))
984 lprops->flags = LPROPS_INDEX;
985 else
986 lprops->flags = 0;
987 lprops->flags |= ubifs_categorize_lprops(c, lprops);
988 }
Sheng Yong235c3622015-03-20 10:39:42 +0000989 err = check_lpt_crc(c, buf, c->pnode_sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300990 return err;
991}
992
993/**
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200994 * ubifs_unpack_nnode - unpack a nnode.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300995 * @c: UBIFS file-system description object
996 * @buf: buffer containing packed nnode to unpack
997 * @nnode: nnode structure to fill
998 *
999 * This function returns %0 on success and a negative error code on failure.
1000 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001001int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
1002 struct ubifs_nnode *nnode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001003{
1004 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1005 int i, pos = 0, err;
1006
Sheng Yong235c3622015-03-20 10:39:42 +00001007 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_NNODE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001008 if (err)
1009 return err;
1010 if (c->big_lpt)
1011 nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1012 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1013 int lnum;
1014
1015 lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
1016 c->lpt_first;
1017 if (lnum == c->lpt_last + 1)
1018 lnum = 0;
1019 nnode->nbranch[i].lnum = lnum;
1020 nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
1021 c->lpt_offs_bits);
1022 }
Sheng Yong235c3622015-03-20 10:39:42 +00001023 err = check_lpt_crc(c, buf, c->nnode_sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001024 return err;
1025}
1026
1027/**
1028 * unpack_ltab - unpack the LPT's own lprops table.
1029 * @c: UBIFS file-system description object
1030 * @buf: buffer from which to unpack
1031 *
1032 * This function returns %0 on success and a negative error code on failure.
1033 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001034static int unpack_ltab(const struct ubifs_info *c, void *buf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001035{
1036 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1037 int i, pos = 0, err;
1038
Sheng Yong235c3622015-03-20 10:39:42 +00001039 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LTAB);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001040 if (err)
1041 return err;
1042 for (i = 0; i < c->lpt_lebs; i++) {
1043 int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1044 int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1045
1046 if (free < 0 || free > c->leb_size || dirty < 0 ||
1047 dirty > c->leb_size || free + dirty > c->leb_size)
1048 return -EINVAL;
1049
1050 c->ltab[i].free = free;
1051 c->ltab[i].dirty = dirty;
1052 c->ltab[i].tgc = 0;
1053 c->ltab[i].cmt = 0;
1054 }
Sheng Yong235c3622015-03-20 10:39:42 +00001055 err = check_lpt_crc(c, buf, c->ltab_sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001056 return err;
1057}
1058
1059/**
1060 * unpack_lsave - unpack the LPT's save table.
1061 * @c: UBIFS file-system description object
1062 * @buf: buffer from which to unpack
1063 *
1064 * This function returns %0 on success and a negative error code on failure.
1065 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001066static int unpack_lsave(const struct ubifs_info *c, void *buf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001067{
1068 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1069 int i, pos = 0, err;
1070
Sheng Yong235c3622015-03-20 10:39:42 +00001071 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LSAVE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001072 if (err)
1073 return err;
1074 for (i = 0; i < c->lsave_cnt; i++) {
1075 int lnum = ubifs_unpack_bits(&addr, &pos, c->lnum_bits);
1076
1077 if (lnum < c->main_first || lnum >= c->leb_cnt)
1078 return -EINVAL;
1079 c->lsave[i] = lnum;
1080 }
Sheng Yong235c3622015-03-20 10:39:42 +00001081 err = check_lpt_crc(c, buf, c->lsave_sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001082 return err;
1083}
1084
1085/**
1086 * validate_nnode - validate a nnode.
1087 * @c: UBIFS file-system description object
1088 * @nnode: nnode to validate
1089 * @parent: parent nnode (or NULL for the root nnode)
1090 * @iip: index in parent
1091 *
1092 * This function returns %0 on success and a negative error code on failure.
1093 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001094static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001095 struct ubifs_nnode *parent, int iip)
1096{
1097 int i, lvl, max_offs;
1098
1099 if (c->big_lpt) {
1100 int num = calc_nnode_num_from_parent(c, parent, iip);
1101
1102 if (nnode->num != num)
1103 return -EINVAL;
1104 }
1105 lvl = parent ? parent->level - 1 : c->lpt_hght;
1106 if (lvl < 1)
1107 return -EINVAL;
1108 if (lvl == 1)
1109 max_offs = c->leb_size - c->pnode_sz;
1110 else
1111 max_offs = c->leb_size - c->nnode_sz;
1112 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1113 int lnum = nnode->nbranch[i].lnum;
1114 int offs = nnode->nbranch[i].offs;
1115
1116 if (lnum == 0) {
1117 if (offs != 0)
1118 return -EINVAL;
1119 continue;
1120 }
1121 if (lnum < c->lpt_first || lnum > c->lpt_last)
1122 return -EINVAL;
1123 if (offs < 0 || offs > max_offs)
1124 return -EINVAL;
1125 }
1126 return 0;
1127}
1128
1129/**
1130 * validate_pnode - validate a pnode.
1131 * @c: UBIFS file-system description object
1132 * @pnode: pnode to validate
1133 * @parent: parent nnode
1134 * @iip: index in parent
1135 *
1136 * This function returns %0 on success and a negative error code on failure.
1137 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001138static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001139 struct ubifs_nnode *parent, int iip)
1140{
1141 int i;
1142
1143 if (c->big_lpt) {
1144 int num = calc_pnode_num_from_parent(c, parent, iip);
1145
1146 if (pnode->num != num)
1147 return -EINVAL;
1148 }
1149 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1150 int free = pnode->lprops[i].free;
1151 int dirty = pnode->lprops[i].dirty;
1152
1153 if (free < 0 || free > c->leb_size || free % c->min_io_size ||
1154 (free & 7))
1155 return -EINVAL;
1156 if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
1157 return -EINVAL;
1158 if (dirty + free > c->leb_size)
1159 return -EINVAL;
1160 }
1161 return 0;
1162}
1163
1164/**
1165 * set_pnode_lnum - set LEB numbers on a pnode.
1166 * @c: UBIFS file-system description object
1167 * @pnode: pnode to update
1168 *
1169 * This function calculates the LEB numbers for the LEB properties it contains
1170 * based on the pnode number.
1171 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001172static void set_pnode_lnum(const struct ubifs_info *c,
1173 struct ubifs_pnode *pnode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001174{
1175 int i, lnum;
1176
1177 lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
1178 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1179 if (lnum >= c->leb_cnt)
1180 return;
1181 pnode->lprops[i].lnum = lnum++;
1182 }
1183}
1184
1185/**
1186 * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
1187 * @c: UBIFS file-system description object
1188 * @parent: parent nnode (or NULL for the root)
1189 * @iip: index in parent
1190 *
1191 * This function returns %0 on success and a negative error code on failure.
1192 */
1193int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1194{
1195 struct ubifs_nbranch *branch = NULL;
1196 struct ubifs_nnode *nnode = NULL;
1197 void *buf = c->lpt_nod_buf;
1198 int err, lnum, offs;
1199
1200 if (parent) {
1201 branch = &parent->nbranch[iip];
1202 lnum = branch->lnum;
1203 offs = branch->offs;
1204 } else {
1205 lnum = c->lpt_lnum;
1206 offs = c->lpt_offs;
1207 }
1208 nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1209 if (!nnode) {
1210 err = -ENOMEM;
1211 goto out;
1212 }
1213 if (lnum == 0) {
1214 /*
1215 * This nnode was not written which just means that the LEB
1216 * properties in the subtree below it describe empty LEBs. We
1217 * make the nnode as though we had read it, which in fact means
1218 * doing almost nothing.
1219 */
1220 if (c->big_lpt)
1221 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1222 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001223 err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001224 if (err)
1225 goto out;
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001226 err = ubifs_unpack_nnode(c, buf, nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001227 if (err)
1228 goto out;
1229 }
1230 err = validate_nnode(c, nnode, parent, iip);
1231 if (err)
1232 goto out;
1233 if (!c->big_lpt)
1234 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1235 if (parent) {
1236 branch->nnode = nnode;
1237 nnode->level = parent->level - 1;
1238 } else {
1239 c->nroot = nnode;
1240 nnode->level = c->lpt_hght;
1241 }
1242 nnode->parent = parent;
1243 nnode->iip = iip;
1244 return 0;
1245
1246out:
Sheng Yong235c3622015-03-20 10:39:42 +00001247 ubifs_err(c, "error %d reading nnode at %d:%d", err, lnum, offs);
Artem Bityutskiy7c46d0a2012-05-16 19:04:54 +03001248 dump_stack();
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001249 kfree(nnode);
1250 return err;
1251}
1252
1253/**
1254 * read_pnode - read a pnode from flash and link it to the tree in memory.
1255 * @c: UBIFS file-system description object
1256 * @parent: parent nnode
1257 * @iip: index in parent
1258 *
1259 * This function returns %0 on success and a negative error code on failure.
1260 */
1261static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1262{
1263 struct ubifs_nbranch *branch;
1264 struct ubifs_pnode *pnode = NULL;
1265 void *buf = c->lpt_nod_buf;
1266 int err, lnum, offs;
1267
1268 branch = &parent->nbranch[iip];
1269 lnum = branch->lnum;
1270 offs = branch->offs;
1271 pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
Artem Bityutskiy54acbaa2011-03-25 19:09:54 +02001272 if (!pnode)
1273 return -ENOMEM;
1274
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001275 if (lnum == 0) {
1276 /*
1277 * This pnode was not written which just means that the LEB
1278 * properties in it describe empty LEBs. We make the pnode as
1279 * though we had read it.
1280 */
1281 int i;
1282
1283 if (c->big_lpt)
1284 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1285 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1286 struct ubifs_lprops * const lprops = &pnode->lprops[i];
1287
1288 lprops->free = c->leb_size;
1289 lprops->flags = ubifs_categorize_lprops(c, lprops);
1290 }
1291 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001292 err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001293 if (err)
1294 goto out;
1295 err = unpack_pnode(c, buf, pnode);
1296 if (err)
1297 goto out;
1298 }
1299 err = validate_pnode(c, pnode, parent, iip);
1300 if (err)
1301 goto out;
1302 if (!c->big_lpt)
1303 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1304 branch->pnode = pnode;
1305 pnode->parent = parent;
1306 pnode->iip = iip;
1307 set_pnode_lnum(c, pnode);
1308 c->pnodes_have += 1;
1309 return 0;
1310
1311out:
Sheng Yong235c3622015-03-20 10:39:42 +00001312 ubifs_err(c, "error %d reading pnode at %d:%d", err, lnum, offs);
Artem Bityutskiyedf6be22012-05-16 19:15:56 +03001313 ubifs_dump_pnode(c, pnode, parent, iip);
Artem Bityutskiy7c46d0a2012-05-16 19:04:54 +03001314 dump_stack();
Sheng Yong235c3622015-03-20 10:39:42 +00001315 ubifs_err(c, "calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001316 kfree(pnode);
1317 return err;
1318}
1319
1320/**
1321 * read_ltab - read LPT's own lprops table.
1322 * @c: UBIFS file-system description object
1323 *
1324 * This function returns %0 on success and a negative error code on failure.
1325 */
1326static int read_ltab(struct ubifs_info *c)
1327{
1328 int err;
1329 void *buf;
1330
1331 buf = vmalloc(c->ltab_sz);
1332 if (!buf)
1333 return -ENOMEM;
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001334 err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001335 if (err)
1336 goto out;
1337 err = unpack_ltab(c, buf);
1338out:
1339 vfree(buf);
1340 return err;
1341}
1342
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;
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001357 err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs,
1358 c->lsave_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001359 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];
Vasiliy Kulikov0e54c892010-09-05 22:33:00 +04001366 struct ubifs_lprops *lprops;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001367
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;
Vasiliy Kulikov0e54c892010-09-05 22:33:00 +04001374 lprops = ubifs_lpt_lookup(c, lnum);
1375 if (IS_ERR(lprops)) {
1376 err = PTR_ERR(lprops);
1377 goto out;
1378 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001379 }
1380out:
1381 vfree(buf);
1382 return err;
1383}
1384
1385/**
1386 * ubifs_get_nnode - get a nnode.
1387 * @c: UBIFS file-system description object
1388 * @parent: parent nnode (or NULL for the root)
1389 * @iip: index in parent
1390 *
1391 * This function returns a pointer to the nnode on success or a negative error
1392 * code on failure.
1393 */
1394struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
1395 struct ubifs_nnode *parent, int iip)
1396{
1397 struct ubifs_nbranch *branch;
1398 struct ubifs_nnode *nnode;
1399 int err;
1400
1401 branch = &parent->nbranch[iip];
1402 nnode = branch->nnode;
1403 if (nnode)
1404 return nnode;
1405 err = ubifs_read_nnode(c, parent, iip);
1406 if (err)
1407 return ERR_PTR(err);
1408 return branch->nnode;
1409}
1410
1411/**
1412 * ubifs_get_pnode - get a pnode.
1413 * @c: UBIFS file-system description object
1414 * @parent: parent nnode
1415 * @iip: index in parent
1416 *
1417 * This function returns a pointer to the pnode on success or a negative error
1418 * code on failure.
1419 */
1420struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
1421 struct ubifs_nnode *parent, int iip)
1422{
1423 struct ubifs_nbranch *branch;
1424 struct ubifs_pnode *pnode;
1425 int err;
1426
1427 branch = &parent->nbranch[iip];
1428 pnode = branch->pnode;
1429 if (pnode)
1430 return pnode;
1431 err = read_pnode(c, parent, iip);
1432 if (err)
1433 return ERR_PTR(err);
1434 update_cats(c, branch->pnode);
1435 return branch->pnode;
1436}
1437
1438/**
1439 * ubifs_lpt_lookup - lookup LEB properties in the LPT.
1440 * @c: UBIFS file-system description object
1441 * @lnum: LEB number to lookup
1442 *
1443 * This function returns a pointer to the LEB properties on success or a
1444 * negative error code on failure.
1445 */
1446struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
1447{
1448 int err, i, h, iip, shft;
1449 struct ubifs_nnode *nnode;
1450 struct ubifs_pnode *pnode;
1451
1452 if (!c->nroot) {
1453 err = ubifs_read_nnode(c, NULL, 0);
1454 if (err)
1455 return ERR_PTR(err);
1456 }
1457 nnode = c->nroot;
1458 i = lnum - c->main_first;
1459 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1460 for (h = 1; h < c->lpt_hght; h++) {
1461 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1462 shft -= UBIFS_LPT_FANOUT_SHIFT;
1463 nnode = ubifs_get_nnode(c, nnode, iip);
1464 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001465 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001466 }
1467 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001468 pnode = ubifs_get_pnode(c, nnode, iip);
1469 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001470 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001471 iip = (i & (UBIFS_LPT_FANOUT - 1));
1472 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1473 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1474 pnode->lprops[iip].flags);
1475 return &pnode->lprops[iip];
1476}
1477
1478/**
1479 * dirty_cow_nnode - ensure a nnode is not being committed.
1480 * @c: UBIFS file-system description object
1481 * @nnode: nnode to check
1482 *
1483 * Returns dirtied nnode on success or negative error code on failure.
1484 */
1485static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
1486 struct ubifs_nnode *nnode)
1487{
1488 struct ubifs_nnode *n;
1489 int i;
1490
1491 if (!test_bit(COW_CNODE, &nnode->flags)) {
1492 /* nnode is not being committed */
1493 if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
1494 c->dirty_nn_cnt += 1;
1495 ubifs_add_nnode_dirt(c, nnode);
1496 }
1497 return nnode;
1498 }
1499
1500 /* nnode is being committed, so copy it */
1501 n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1502 if (unlikely(!n))
1503 return ERR_PTR(-ENOMEM);
1504
1505 memcpy(n, nnode, sizeof(struct ubifs_nnode));
1506 n->cnext = NULL;
1507 __set_bit(DIRTY_CNODE, &n->flags);
1508 __clear_bit(COW_CNODE, &n->flags);
1509
1510 /* The children now have new parent */
1511 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1512 struct ubifs_nbranch *branch = &n->nbranch[i];
1513
1514 if (branch->cnode)
1515 branch->cnode->parent = n;
1516 }
1517
1518 ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
1519 __set_bit(OBSOLETE_CNODE, &nnode->flags);
1520
1521 c->dirty_nn_cnt += 1;
1522 ubifs_add_nnode_dirt(c, nnode);
1523 if (nnode->parent)
1524 nnode->parent->nbranch[n->iip].nnode = n;
1525 else
1526 c->nroot = n;
1527 return n;
1528}
1529
1530/**
1531 * dirty_cow_pnode - ensure a pnode is not being committed.
1532 * @c: UBIFS file-system description object
1533 * @pnode: pnode to check
1534 *
1535 * Returns dirtied pnode on success or negative error code on failure.
1536 */
1537static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
1538 struct ubifs_pnode *pnode)
1539{
1540 struct ubifs_pnode *p;
1541
1542 if (!test_bit(COW_CNODE, &pnode->flags)) {
1543 /* pnode is not being committed */
1544 if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
1545 c->dirty_pn_cnt += 1;
1546 add_pnode_dirt(c, pnode);
1547 }
1548 return pnode;
1549 }
1550
1551 /* pnode is being committed, so copy it */
1552 p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1553 if (unlikely(!p))
1554 return ERR_PTR(-ENOMEM);
1555
1556 memcpy(p, pnode, sizeof(struct ubifs_pnode));
1557 p->cnext = NULL;
1558 __set_bit(DIRTY_CNODE, &p->flags);
1559 __clear_bit(COW_CNODE, &p->flags);
1560 replace_cats(c, pnode, p);
1561
1562 ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
1563 __set_bit(OBSOLETE_CNODE, &pnode->flags);
1564
1565 c->dirty_pn_cnt += 1;
1566 add_pnode_dirt(c, pnode);
1567 pnode->parent->nbranch[p->iip].pnode = p;
1568 return p;
1569}
1570
1571/**
1572 * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
1573 * @c: UBIFS file-system description object
1574 * @lnum: LEB number to lookup
1575 *
1576 * This function returns a pointer to the LEB properties on success or a
1577 * negative error code on failure.
1578 */
1579struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
1580{
1581 int err, i, h, iip, shft;
1582 struct ubifs_nnode *nnode;
1583 struct ubifs_pnode *pnode;
1584
1585 if (!c->nroot) {
1586 err = ubifs_read_nnode(c, NULL, 0);
1587 if (err)
1588 return ERR_PTR(err);
1589 }
1590 nnode = c->nroot;
1591 nnode = dirty_cow_nnode(c, nnode);
1592 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001593 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001594 i = lnum - c->main_first;
1595 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1596 for (h = 1; h < c->lpt_hght; h++) {
1597 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1598 shft -= UBIFS_LPT_FANOUT_SHIFT;
1599 nnode = ubifs_get_nnode(c, nnode, iip);
1600 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001601 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001602 nnode = dirty_cow_nnode(c, nnode);
1603 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001604 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001605 }
1606 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001607 pnode = ubifs_get_pnode(c, nnode, iip);
1608 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001609 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001610 pnode = dirty_cow_pnode(c, pnode);
1611 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001612 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001613 iip = (i & (UBIFS_LPT_FANOUT - 1));
1614 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1615 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1616 pnode->lprops[iip].flags);
1617 ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
1618 return &pnode->lprops[iip];
1619}
1620
1621/**
1622 * lpt_init_rd - initialize the LPT for reading.
1623 * @c: UBIFS file-system description object
1624 *
1625 * This function returns %0 on success and a negative error code on failure.
1626 */
1627static int lpt_init_rd(struct ubifs_info *c)
1628{
1629 int err, i;
1630
1631 c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1632 if (!c->ltab)
1633 return -ENOMEM;
1634
1635 i = max_t(int, c->nnode_sz, c->pnode_sz);
1636 c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
1637 if (!c->lpt_nod_buf)
1638 return -ENOMEM;
1639
1640 for (i = 0; i < LPROPS_HEAP_CNT; i++) {
1641 c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
1642 GFP_KERNEL);
1643 if (!c->lpt_heap[i].arr)
1644 return -ENOMEM;
1645 c->lpt_heap[i].cnt = 0;
1646 c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
1647 }
1648
1649 c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
1650 if (!c->dirty_idx.arr)
1651 return -ENOMEM;
1652 c->dirty_idx.cnt = 0;
1653 c->dirty_idx.max_cnt = LPT_HEAP_SZ;
1654
1655 err = read_ltab(c);
1656 if (err)
1657 return err;
1658
1659 dbg_lp("space_bits %d", c->space_bits);
1660 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
1661 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
1662 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
1663 dbg_lp("pcnt_bits %d", c->pcnt_bits);
1664 dbg_lp("lnum_bits %d", c->lnum_bits);
1665 dbg_lp("pnode_sz %d", c->pnode_sz);
1666 dbg_lp("nnode_sz %d", c->nnode_sz);
1667 dbg_lp("ltab_sz %d", c->ltab_sz);
1668 dbg_lp("lsave_sz %d", c->lsave_sz);
1669 dbg_lp("lsave_cnt %d", c->lsave_cnt);
1670 dbg_lp("lpt_hght %d", c->lpt_hght);
1671 dbg_lp("big_lpt %d", c->big_lpt);
1672 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
1673 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
1674 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
1675 if (c->big_lpt)
1676 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
1677
1678 return 0;
1679}
1680
1681/**
1682 * lpt_init_wr - initialize the LPT for writing.
1683 * @c: UBIFS file-system description object
1684 *
1685 * 'lpt_init_rd()' must have been called already.
1686 *
1687 * This function returns %0 on success and a negative error code on failure.
1688 */
1689static int lpt_init_wr(struct ubifs_info *c)
1690{
1691 int err, i;
1692
1693 c->ltab_cmt = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1694 if (!c->ltab_cmt)
1695 return -ENOMEM;
1696
1697 c->lpt_buf = vmalloc(c->leb_size);
1698 if (!c->lpt_buf)
1699 return -ENOMEM;
1700
1701 if (c->big_lpt) {
1702 c->lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_NOFS);
1703 if (!c->lsave)
1704 return -ENOMEM;
1705 err = read_lsave(c);
1706 if (err)
1707 return err;
1708 }
1709
1710 for (i = 0; i < c->lpt_lebs; i++)
1711 if (c->ltab[i].free == c->leb_size) {
1712 err = ubifs_leb_unmap(c, i + c->lpt_first);
1713 if (err)
1714 return err;
1715 }
1716
1717 return 0;
1718}
1719
1720/**
1721 * ubifs_lpt_init - initialize the LPT.
1722 * @c: UBIFS file-system description object
1723 * @rd: whether to initialize lpt for reading
1724 * @wr: whether to initialize lpt for writing
1725 *
1726 * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
1727 * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
1728 * true.
1729 *
1730 * This function returns %0 on success and a negative error code on failure.
1731 */
1732int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
1733{
1734 int err;
1735
1736 if (rd) {
1737 err = lpt_init_rd(c);
1738 if (err)
Artem Bityutskiy49942972012-05-18 14:32:36 +03001739 goto out_err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001740 }
1741
1742 if (wr) {
1743 err = lpt_init_wr(c);
1744 if (err)
Artem Bityutskiy49942972012-05-18 14:32:36 +03001745 goto out_err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001746 }
1747
1748 return 0;
Artem Bityutskiy49942972012-05-18 14:32:36 +03001749
1750out_err:
Artem Bityutskiy11e3be02012-08-20 15:16:24 +03001751 if (wr)
1752 ubifs_lpt_free(c, 1);
1753 if (rd)
1754 ubifs_lpt_free(c, 0);
Artem Bityutskiy49942972012-05-18 14:32:36 +03001755 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001756}
1757
1758/**
1759 * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
1760 * @nnode: where to keep a nnode
1761 * @pnode: where to keep a pnode
1762 * @cnode: where to keep a cnode
1763 * @in_tree: is the node in the tree in memory
1764 * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
1765 * the tree
1766 * @ptr.pnode: ditto for pnode
1767 * @ptr.cnode: ditto for cnode
1768 */
1769struct lpt_scan_node {
1770 union {
1771 struct ubifs_nnode nnode;
1772 struct ubifs_pnode pnode;
1773 struct ubifs_cnode cnode;
1774 };
1775 int in_tree;
1776 union {
1777 struct ubifs_nnode *nnode;
1778 struct ubifs_pnode *pnode;
1779 struct ubifs_cnode *cnode;
1780 } ptr;
1781};
1782
1783/**
1784 * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
1785 * @c: the UBIFS file-system description object
1786 * @path: where to put the nnode
1787 * @parent: parent of the nnode
1788 * @iip: index in parent of the nnode
1789 *
1790 * This function returns a pointer to the nnode on success or a negative error
1791 * code on failure.
1792 */
1793static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
1794 struct lpt_scan_node *path,
1795 struct ubifs_nnode *parent, int iip)
1796{
1797 struct ubifs_nbranch *branch;
1798 struct ubifs_nnode *nnode;
1799 void *buf = c->lpt_nod_buf;
1800 int err;
1801
1802 branch = &parent->nbranch[iip];
1803 nnode = branch->nnode;
1804 if (nnode) {
1805 path->in_tree = 1;
1806 path->ptr.nnode = nnode;
1807 return nnode;
1808 }
1809 nnode = &path->nnode;
1810 path->in_tree = 0;
1811 path->ptr.nnode = nnode;
1812 memset(nnode, 0, sizeof(struct ubifs_nnode));
1813 if (branch->lnum == 0) {
1814 /*
1815 * This nnode was not written which just means that the LEB
1816 * properties in the subtree below it describe empty LEBs. We
1817 * make the nnode as though we had read it, which in fact means
1818 * doing almost nothing.
1819 */
1820 if (c->big_lpt)
1821 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1822 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001823 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1824 c->nnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001825 if (err)
1826 return ERR_PTR(err);
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001827 err = ubifs_unpack_nnode(c, buf, nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001828 if (err)
1829 return ERR_PTR(err);
1830 }
1831 err = validate_nnode(c, nnode, parent, iip);
1832 if (err)
1833 return ERR_PTR(err);
1834 if (!c->big_lpt)
1835 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1836 nnode->level = parent->level - 1;
1837 nnode->parent = parent;
1838 nnode->iip = iip;
1839 return nnode;
1840}
1841
1842/**
1843 * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
1844 * @c: the UBIFS file-system description object
1845 * @path: where to put the pnode
1846 * @parent: parent of the pnode
1847 * @iip: index in parent of the pnode
1848 *
1849 * This function returns a pointer to the pnode on success or a negative error
1850 * code on failure.
1851 */
1852static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
1853 struct lpt_scan_node *path,
1854 struct ubifs_nnode *parent, int iip)
1855{
1856 struct ubifs_nbranch *branch;
1857 struct ubifs_pnode *pnode;
1858 void *buf = c->lpt_nod_buf;
1859 int err;
1860
1861 branch = &parent->nbranch[iip];
1862 pnode = branch->pnode;
1863 if (pnode) {
1864 path->in_tree = 1;
1865 path->ptr.pnode = pnode;
1866 return pnode;
1867 }
1868 pnode = &path->pnode;
1869 path->in_tree = 0;
1870 path->ptr.pnode = pnode;
1871 memset(pnode, 0, sizeof(struct ubifs_pnode));
1872 if (branch->lnum == 0) {
1873 /*
1874 * This pnode was not written which just means that the LEB
1875 * properties in it describe empty LEBs. We make the pnode as
1876 * though we had read it.
1877 */
1878 int i;
1879
1880 if (c->big_lpt)
1881 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1882 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1883 struct ubifs_lprops * const lprops = &pnode->lprops[i];
1884
1885 lprops->free = c->leb_size;
1886 lprops->flags = ubifs_categorize_lprops(c, lprops);
1887 }
1888 } else {
1889 ubifs_assert(branch->lnum >= c->lpt_first &&
1890 branch->lnum <= c->lpt_last);
1891 ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001892 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1893 c->pnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001894 if (err)
1895 return ERR_PTR(err);
1896 err = unpack_pnode(c, buf, pnode);
1897 if (err)
1898 return ERR_PTR(err);
1899 }
1900 err = validate_pnode(c, pnode, parent, iip);
1901 if (err)
1902 return ERR_PTR(err);
1903 if (!c->big_lpt)
1904 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1905 pnode->parent = parent;
1906 pnode->iip = iip;
1907 set_pnode_lnum(c, pnode);
1908 return pnode;
1909}
1910
1911/**
1912 * ubifs_lpt_scan_nolock - scan the LPT.
1913 * @c: the UBIFS file-system description object
1914 * @start_lnum: LEB number from which to start scanning
1915 * @end_lnum: LEB number at which to stop scanning
1916 * @scan_cb: callback function called for each lprops
1917 * @data: data to be passed to the callback function
1918 *
1919 * This function returns %0 on success and a negative error code on failure.
1920 */
1921int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
1922 ubifs_lpt_scan_callback scan_cb, void *data)
1923{
1924 int err = 0, i, h, iip, shft;
1925 struct ubifs_nnode *nnode;
1926 struct ubifs_pnode *pnode;
1927 struct lpt_scan_node *path;
1928
1929 if (start_lnum == -1) {
1930 start_lnum = end_lnum + 1;
1931 if (start_lnum >= c->leb_cnt)
1932 start_lnum = c->main_first;
1933 }
1934
1935 ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
1936 ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
1937
1938 if (!c->nroot) {
1939 err = ubifs_read_nnode(c, NULL, 0);
1940 if (err)
1941 return err;
1942 }
1943
1944 path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
1945 GFP_NOFS);
1946 if (!path)
1947 return -ENOMEM;
1948
1949 path[0].ptr.nnode = c->nroot;
1950 path[0].in_tree = 1;
1951again:
1952 /* Descend to the pnode containing start_lnum */
1953 nnode = c->nroot;
1954 i = start_lnum - c->main_first;
1955 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1956 for (h = 1; h < c->lpt_hght; h++) {
1957 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1958 shft -= UBIFS_LPT_FANOUT_SHIFT;
1959 nnode = scan_get_nnode(c, path + h, nnode, iip);
1960 if (IS_ERR(nnode)) {
1961 err = PTR_ERR(nnode);
1962 goto out;
1963 }
1964 }
1965 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001966 pnode = scan_get_pnode(c, path + h, nnode, iip);
1967 if (IS_ERR(pnode)) {
1968 err = PTR_ERR(pnode);
1969 goto out;
1970 }
1971 iip = (i & (UBIFS_LPT_FANOUT - 1));
1972
1973 /* Loop for each lprops */
1974 while (1) {
1975 struct ubifs_lprops *lprops = &pnode->lprops[iip];
1976 int ret, lnum = lprops->lnum;
1977
1978 ret = scan_cb(c, lprops, path[h].in_tree, data);
1979 if (ret < 0) {
1980 err = ret;
1981 goto out;
1982 }
1983 if (ret & LPT_SCAN_ADD) {
1984 /* Add all the nodes in path to the tree in memory */
1985 for (h = 1; h < c->lpt_hght; h++) {
1986 const size_t sz = sizeof(struct ubifs_nnode);
1987 struct ubifs_nnode *parent;
1988
1989 if (path[h].in_tree)
1990 continue;
Thomas Meyereaecf432011-11-18 00:00:52 +01001991 nnode = kmemdup(&path[h].nnode, sz, GFP_NOFS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001992 if (!nnode) {
1993 err = -ENOMEM;
1994 goto out;
1995 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001996 parent = nnode->parent;
1997 parent->nbranch[nnode->iip].nnode = nnode;
1998 path[h].ptr.nnode = nnode;
1999 path[h].in_tree = 1;
2000 path[h + 1].cnode.parent = nnode;
2001 }
2002 if (path[h].in_tree)
2003 ubifs_ensure_cat(c, lprops);
2004 else {
2005 const size_t sz = sizeof(struct ubifs_pnode);
2006 struct ubifs_nnode *parent;
2007
Thomas Meyereaecf432011-11-18 00:00:52 +01002008 pnode = kmemdup(&path[h].pnode, sz, GFP_NOFS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002009 if (!pnode) {
2010 err = -ENOMEM;
2011 goto out;
2012 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002013 parent = pnode->parent;
2014 parent->nbranch[pnode->iip].pnode = pnode;
2015 path[h].ptr.pnode = pnode;
2016 path[h].in_tree = 1;
2017 update_cats(c, pnode);
2018 c->pnodes_have += 1;
2019 }
2020 err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)
2021 c->nroot, 0, 0);
2022 if (err)
2023 goto out;
2024 err = dbg_check_cats(c);
2025 if (err)
2026 goto out;
2027 }
2028 if (ret & LPT_SCAN_STOP) {
2029 err = 0;
2030 break;
2031 }
2032 /* Get the next lprops */
2033 if (lnum == end_lnum) {
2034 /*
2035 * We got to the end without finding what we were
2036 * looking for
2037 */
2038 err = -ENOSPC;
2039 goto out;
2040 }
2041 if (lnum + 1 >= c->leb_cnt) {
2042 /* Wrap-around to the beginning */
2043 start_lnum = c->main_first;
2044 goto again;
2045 }
2046 if (iip + 1 < UBIFS_LPT_FANOUT) {
2047 /* Next lprops is in the same pnode */
2048 iip += 1;
2049 continue;
2050 }
2051 /* We need to get the next pnode. Go up until we can go right */
2052 iip = pnode->iip;
2053 while (1) {
2054 h -= 1;
2055 ubifs_assert(h >= 0);
2056 nnode = path[h].ptr.nnode;
2057 if (iip + 1 < UBIFS_LPT_FANOUT)
2058 break;
2059 iip = nnode->iip;
2060 }
2061 /* Go right */
2062 iip += 1;
2063 /* Descend to the pnode */
2064 h += 1;
2065 for (; h < c->lpt_hght; h++) {
2066 nnode = scan_get_nnode(c, path + h, nnode, iip);
2067 if (IS_ERR(nnode)) {
2068 err = PTR_ERR(nnode);
2069 goto out;
2070 }
2071 iip = 0;
2072 }
2073 pnode = scan_get_pnode(c, path + h, nnode, iip);
2074 if (IS_ERR(pnode)) {
2075 err = PTR_ERR(pnode);
2076 goto out;
2077 }
2078 iip = 0;
2079 }
2080out:
2081 kfree(path);
2082 return err;
2083}
2084
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002085/**
2086 * dbg_chk_pnode - check a pnode.
2087 * @c: the UBIFS file-system description object
2088 * @pnode: pnode to check
2089 * @col: pnode column
2090 *
2091 * This function returns %0 on success and a negative error code on failure.
2092 */
2093static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
2094 int col)
2095{
2096 int i;
2097
2098 if (pnode->num != col) {
Sheng Yong235c3622015-03-20 10:39:42 +00002099 ubifs_err(c, "pnode num %d expected %d parent num %d iip %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002100 pnode->num, col, pnode->parent->num, pnode->iip);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002101 return -EINVAL;
2102 }
2103 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2104 struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
2105 int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
2106 c->main_first;
2107 int found, cat = lprops->flags & LPROPS_CAT_MASK;
2108 struct ubifs_lpt_heap *heap;
2109 struct list_head *list = NULL;
2110
2111 if (lnum >= c->leb_cnt)
2112 continue;
2113 if (lprops->lnum != lnum) {
Sheng Yong235c3622015-03-20 10:39:42 +00002114 ubifs_err(c, "bad LEB number %d expected %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002115 lprops->lnum, lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002116 return -EINVAL;
2117 }
2118 if (lprops->flags & LPROPS_TAKEN) {
2119 if (cat != LPROPS_UNCAT) {
Sheng Yong235c3622015-03-20 10:39:42 +00002120 ubifs_err(c, "LEB %d taken but not uncat %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002121 lprops->lnum, cat);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002122 return -EINVAL;
2123 }
2124 continue;
2125 }
2126 if (lprops->flags & LPROPS_INDEX) {
2127 switch (cat) {
2128 case LPROPS_UNCAT:
2129 case LPROPS_DIRTY_IDX:
2130 case LPROPS_FRDI_IDX:
2131 break;
2132 default:
Sheng Yong235c3622015-03-20 10:39:42 +00002133 ubifs_err(c, "LEB %d index but cat %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002134 lprops->lnum, cat);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002135 return -EINVAL;
2136 }
2137 } else {
2138 switch (cat) {
2139 case LPROPS_UNCAT:
2140 case LPROPS_DIRTY:
2141 case LPROPS_FREE:
2142 case LPROPS_EMPTY:
2143 case LPROPS_FREEABLE:
2144 break;
2145 default:
Sheng Yong235c3622015-03-20 10:39:42 +00002146 ubifs_err(c, "LEB %d not index but cat %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002147 lprops->lnum, cat);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002148 return -EINVAL;
2149 }
2150 }
2151 switch (cat) {
2152 case LPROPS_UNCAT:
2153 list = &c->uncat_list;
2154 break;
2155 case LPROPS_EMPTY:
2156 list = &c->empty_list;
2157 break;
2158 case LPROPS_FREEABLE:
2159 list = &c->freeable_list;
2160 break;
2161 case LPROPS_FRDI_IDX:
2162 list = &c->frdi_idx_list;
2163 break;
2164 }
2165 found = 0;
2166 switch (cat) {
2167 case LPROPS_DIRTY:
2168 case LPROPS_DIRTY_IDX:
2169 case LPROPS_FREE:
2170 heap = &c->lpt_heap[cat - 1];
2171 if (lprops->hpos < heap->cnt &&
2172 heap->arr[lprops->hpos] == lprops)
2173 found = 1;
2174 break;
2175 case LPROPS_UNCAT:
2176 case LPROPS_EMPTY:
2177 case LPROPS_FREEABLE:
2178 case LPROPS_FRDI_IDX:
2179 list_for_each_entry(lp, list, list)
2180 if (lprops == lp) {
2181 found = 1;
2182 break;
2183 }
2184 break;
2185 }
2186 if (!found) {
Sheng Yong235c3622015-03-20 10:39:42 +00002187 ubifs_err(c, "LEB %d cat %d not found in cat heap/list",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002188 lprops->lnum, cat);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002189 return -EINVAL;
2190 }
2191 switch (cat) {
2192 case LPROPS_EMPTY:
2193 if (lprops->free != c->leb_size) {
Sheng Yong235c3622015-03-20 10:39:42 +00002194 ubifs_err(c, "LEB %d cat %d free %d dirty %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002195 lprops->lnum, cat, lprops->free,
2196 lprops->dirty);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002197 return -EINVAL;
2198 }
hujianyangce6ebdb2014-06-11 10:41:17 +08002199 break;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002200 case LPROPS_FREEABLE:
2201 case LPROPS_FRDI_IDX:
2202 if (lprops->free + lprops->dirty != c->leb_size) {
Sheng Yong235c3622015-03-20 10:39:42 +00002203 ubifs_err(c, "LEB %d cat %d free %d dirty %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002204 lprops->lnum, cat, lprops->free,
2205 lprops->dirty);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002206 return -EINVAL;
2207 }
hujianyangce6ebdb2014-06-11 10:41:17 +08002208 break;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002209 }
2210 }
2211 return 0;
2212}
2213
2214/**
2215 * dbg_check_lpt_nodes - check nnodes and pnodes.
2216 * @c: the UBIFS file-system description object
2217 * @cnode: next cnode (nnode or pnode) to check
2218 * @row: row of cnode (root is zero)
2219 * @col: column of cnode (leftmost is zero)
2220 *
2221 * This function returns %0 on success and a negative error code on failure.
2222 */
2223int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
2224 int row, int col)
2225{
2226 struct ubifs_nnode *nnode, *nn;
2227 struct ubifs_cnode *cn;
2228 int num, iip = 0, err;
2229
Artem Bityutskiy2b1844a2011-06-03 08:31:29 +03002230 if (!dbg_is_chk_lprops(c))
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002231 return 0;
2232
2233 while (cnode) {
2234 ubifs_assert(row >= 0);
2235 nnode = cnode->parent;
2236 if (cnode->level) {
2237 /* cnode is a nnode */
2238 num = calc_nnode_num(row, col);
2239 if (cnode->num != num) {
Sheng Yong235c3622015-03-20 10:39:42 +00002240 ubifs_err(c, "nnode num %d expected %d parent num %d iip %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +03002241 cnode->num, num,
2242 (nnode ? nnode->num : 0), cnode->iip);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002243 return -EINVAL;
2244 }
2245 nn = (struct ubifs_nnode *)cnode;
2246 while (iip < UBIFS_LPT_FANOUT) {
2247 cn = nn->nbranch[iip].cnode;
2248 if (cn) {
2249 /* Go down */
2250 row += 1;
2251 col <<= UBIFS_LPT_FANOUT_SHIFT;
2252 col += iip;
2253 iip = 0;
2254 cnode = cn;
2255 break;
2256 }
2257 /* Go right */
2258 iip += 1;
2259 }
2260 if (iip < UBIFS_LPT_FANOUT)
2261 continue;
2262 } else {
2263 struct ubifs_pnode *pnode;
2264
2265 /* cnode is a pnode */
2266 pnode = (struct ubifs_pnode *)cnode;
2267 err = dbg_chk_pnode(c, pnode, col);
2268 if (err)
2269 return err;
2270 }
2271 /* Go up and to the right */
2272 row -= 1;
2273 col >>= UBIFS_LPT_FANOUT_SHIFT;
2274 iip = cnode->iip + 1;
2275 cnode = (struct ubifs_cnode *)nnode;
2276 }
2277 return 0;
2278}