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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) {
148 ubifs_err("too few LPT LEBs");
149 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) {
154 ubifs_err("LPT ltab too big");
155 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) {
216 ubifs_err("LPT ltab too big");
217 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);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300704 err = ubifs_leb_change(c, lnum++, buf, alen,
705 UBI_SHORTTERM);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300706 if (err)
707 goto out;
708 p = buf;
709 len = 0;
710 }
711 ubifs_pack_pnode(c, p, pnode);
712 p += c->pnode_sz;
713 len += c->pnode_sz;
714 /*
715 * pnodes are simply numbered left to right starting at zero,
716 * which means the pnode number can be used easily to traverse
717 * down the tree to the corresponding pnode.
718 */
719 pnode->num += 1;
720 }
721
722 row = 0;
723 for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
724 row += 1;
725 /* Add all nnodes, one level at a time */
726 while (1) {
727 /* Number of internal nodes (nnodes) at next level */
728 cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
729 for (i = 0; i < cnt; i++) {
730 if (len + c->nnode_sz > c->leb_size) {
731 alen = ALIGN(len, c->min_io_size);
732 set_ltab(c, lnum, c->leb_size - alen,
733 alen - len);
734 memset(p, 0xff, alen - len);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300735 err = ubifs_leb_change(c, lnum++, buf, alen,
736 UBI_SHORTTERM);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300737 if (err)
738 goto out;
739 p = buf;
740 len = 0;
741 }
742 /* Only 1 nnode at this level, so it is the root */
743 if (cnt == 1) {
744 c->lpt_lnum = lnum;
745 c->lpt_offs = len;
746 }
747 /* Set branches to the level below */
748 for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
749 if (bcnt) {
750 if (boffs + bsz > c->leb_size) {
751 blnum += 1;
752 boffs = 0;
753 }
754 nnode->nbranch[j].lnum = blnum;
755 nnode->nbranch[j].offs = boffs;
756 boffs += bsz;
757 bcnt--;
758 } else {
759 nnode->nbranch[j].lnum = 0;
760 nnode->nbranch[j].offs = 0;
761 }
762 }
763 nnode->num = calc_nnode_num(row, i);
764 ubifs_pack_nnode(c, p, nnode);
765 p += c->nnode_sz;
766 len += c->nnode_sz;
767 }
768 /* Only 1 nnode at this level, so it is the root */
769 if (cnt == 1)
770 break;
771 /* Update the information about the level below */
772 bcnt = cnt;
773 bsz = c->nnode_sz;
774 row -= 1;
775 }
776
777 if (*big_lpt) {
778 /* Need to add LPT's save table */
779 if (len + c->lsave_sz > c->leb_size) {
780 alen = ALIGN(len, c->min_io_size);
781 set_ltab(c, lnum, c->leb_size - alen, alen - len);
782 memset(p, 0xff, alen - len);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300783 err = ubifs_leb_change(c, lnum++, buf, alen,
784 UBI_SHORTTERM);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300785 if (err)
786 goto out;
787 p = buf;
788 len = 0;
789 }
790
791 c->lsave_lnum = lnum;
792 c->lsave_offs = len;
793
794 for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
795 lsave[i] = c->main_first + i;
796 for (; i < c->lsave_cnt; i++)
797 lsave[i] = c->main_first;
798
799 ubifs_pack_lsave(c, p, lsave);
800 p += c->lsave_sz;
801 len += c->lsave_sz;
802 }
803
804 /* Need to add LPT's own LEB properties table */
805 if (len + c->ltab_sz > c->leb_size) {
806 alen = ALIGN(len, c->min_io_size);
807 set_ltab(c, lnum, c->leb_size - alen, alen - len);
808 memset(p, 0xff, alen - len);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300809 err = ubifs_leb_change(c, lnum++, buf, alen, UBI_SHORTTERM);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300810 if (err)
811 goto out;
812 p = buf;
813 len = 0;
814 }
815
816 c->ltab_lnum = lnum;
817 c->ltab_offs = len;
818
819 /* Update ltab before packing it */
820 len += c->ltab_sz;
821 alen = ALIGN(len, c->min_io_size);
822 set_ltab(c, lnum, c->leb_size - alen, alen - len);
823
824 ubifs_pack_ltab(c, p, ltab);
825 p += c->ltab_sz;
826
827 /* Write remaining buffer */
828 memset(p, 0xff, alen - len);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300829 err = ubifs_leb_change(c, lnum, buf, alen, UBI_SHORTTERM);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300830 if (err)
831 goto out;
832
833 c->nhead_lnum = lnum;
834 c->nhead_offs = ALIGN(len, c->min_io_size);
835
836 dbg_lp("space_bits %d", c->space_bits);
837 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
838 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
839 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
840 dbg_lp("pcnt_bits %d", c->pcnt_bits);
841 dbg_lp("lnum_bits %d", c->lnum_bits);
842 dbg_lp("pnode_sz %d", c->pnode_sz);
843 dbg_lp("nnode_sz %d", c->nnode_sz);
844 dbg_lp("ltab_sz %d", c->ltab_sz);
845 dbg_lp("lsave_sz %d", c->lsave_sz);
846 dbg_lp("lsave_cnt %d", c->lsave_cnt);
847 dbg_lp("lpt_hght %d", c->lpt_hght);
848 dbg_lp("big_lpt %d", c->big_lpt);
849 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
850 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
851 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
852 if (c->big_lpt)
853 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
854out:
855 c->ltab = NULL;
856 kfree(lsave);
857 vfree(ltab);
858 vfree(buf);
859 kfree(nnode);
860 kfree(pnode);
861 return err;
862}
863
864/**
865 * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
866 * @c: UBIFS file-system description object
867 * @pnode: pnode
868 *
869 * When a pnode is loaded into memory, the LEB properties it contains are added,
870 * by this function, to the LEB category lists and heaps.
871 */
872static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
873{
874 int i;
875
876 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
877 int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
878 int lnum = pnode->lprops[i].lnum;
879
880 if (!lnum)
881 return;
882 ubifs_add_to_cat(c, &pnode->lprops[i], cat);
883 }
884}
885
886/**
887 * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
888 * @c: UBIFS file-system description object
889 * @old_pnode: pnode copied
890 * @new_pnode: pnode copy
891 *
892 * During commit it is sometimes necessary to copy a pnode
893 * (see dirty_cow_pnode). When that happens, references in
894 * category lists and heaps must be replaced. This function does that.
895 */
896static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
897 struct ubifs_pnode *new_pnode)
898{
899 int i;
900
901 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
902 if (!new_pnode->lprops[i].lnum)
903 return;
904 ubifs_replace_cat(c, &old_pnode->lprops[i],
905 &new_pnode->lprops[i]);
906 }
907}
908
909/**
910 * check_lpt_crc - check LPT node crc is correct.
911 * @c: UBIFS file-system description object
912 * @buf: buffer containing node
913 * @len: length of node
914 *
915 * This function returns %0 on success and a negative error code on failure.
916 */
917static int check_lpt_crc(void *buf, int len)
918{
919 int pos = 0;
920 uint8_t *addr = buf;
921 uint16_t crc, calc_crc;
922
923 crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
924 calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
925 len - UBIFS_LPT_CRC_BYTES);
926 if (crc != calc_crc) {
927 ubifs_err("invalid crc in LPT node: crc %hx calc %hx", crc,
928 calc_crc);
929 dbg_dump_stack();
930 return -EINVAL;
931 }
932 return 0;
933}
934
935/**
936 * check_lpt_type - check LPT node type is correct.
937 * @c: UBIFS file-system description object
938 * @addr: address of type bit field is passed and returned updated here
939 * @pos: position of type bit field is passed and returned updated here
940 * @type: expected type
941 *
942 * This function returns %0 on success and a negative error code on failure.
943 */
944static int check_lpt_type(uint8_t **addr, int *pos, int type)
945{
946 int node_type;
947
948 node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
949 if (node_type != type) {
950 ubifs_err("invalid type (%d) in LPT node type %d", node_type,
951 type);
952 dbg_dump_stack();
953 return -EINVAL;
954 }
955 return 0;
956}
957
958/**
959 * unpack_pnode - unpack a pnode.
960 * @c: UBIFS file-system description object
961 * @buf: buffer containing packed pnode to unpack
962 * @pnode: pnode structure to fill
963 *
964 * This function returns %0 on success and a negative error code on failure.
965 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200966static int unpack_pnode(const struct ubifs_info *c, void *buf,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300967 struct ubifs_pnode *pnode)
968{
969 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
970 int i, pos = 0, err;
971
972 err = check_lpt_type(&addr, &pos, UBIFS_LPT_PNODE);
973 if (err)
974 return err;
975 if (c->big_lpt)
976 pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
977 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
978 struct ubifs_lprops * const lprops = &pnode->lprops[i];
979
980 lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
981 lprops->free <<= 3;
982 lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
983 lprops->dirty <<= 3;
984
985 if (ubifs_unpack_bits(&addr, &pos, 1))
986 lprops->flags = LPROPS_INDEX;
987 else
988 lprops->flags = 0;
989 lprops->flags |= ubifs_categorize_lprops(c, lprops);
990 }
991 err = check_lpt_crc(buf, c->pnode_sz);
992 return err;
993}
994
995/**
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +0200996 * ubifs_unpack_nnode - unpack a nnode.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300997 * @c: UBIFS file-system description object
998 * @buf: buffer containing packed nnode to unpack
999 * @nnode: nnode structure to fill
1000 *
1001 * This function returns %0 on success and a negative error code on failure.
1002 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001003int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
1004 struct ubifs_nnode *nnode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001005{
1006 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1007 int i, pos = 0, err;
1008
1009 err = check_lpt_type(&addr, &pos, UBIFS_LPT_NNODE);
1010 if (err)
1011 return err;
1012 if (c->big_lpt)
1013 nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
1014 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1015 int lnum;
1016
1017 lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
1018 c->lpt_first;
1019 if (lnum == c->lpt_last + 1)
1020 lnum = 0;
1021 nnode->nbranch[i].lnum = lnum;
1022 nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
1023 c->lpt_offs_bits);
1024 }
1025 err = check_lpt_crc(buf, c->nnode_sz);
1026 return err;
1027}
1028
1029/**
1030 * unpack_ltab - unpack the LPT's own lprops table.
1031 * @c: UBIFS file-system description object
1032 * @buf: buffer from which to unpack
1033 *
1034 * This function returns %0 on success and a negative error code on failure.
1035 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001036static int unpack_ltab(const struct ubifs_info *c, void *buf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001037{
1038 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1039 int i, pos = 0, err;
1040
1041 err = check_lpt_type(&addr, &pos, UBIFS_LPT_LTAB);
1042 if (err)
1043 return err;
1044 for (i = 0; i < c->lpt_lebs; i++) {
1045 int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1046 int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
1047
1048 if (free < 0 || free > c->leb_size || dirty < 0 ||
1049 dirty > c->leb_size || free + dirty > c->leb_size)
1050 return -EINVAL;
1051
1052 c->ltab[i].free = free;
1053 c->ltab[i].dirty = dirty;
1054 c->ltab[i].tgc = 0;
1055 c->ltab[i].cmt = 0;
1056 }
1057 err = check_lpt_crc(buf, c->ltab_sz);
1058 return err;
1059}
1060
1061/**
1062 * unpack_lsave - unpack the LPT's save table.
1063 * @c: UBIFS file-system description object
1064 * @buf: buffer from which to unpack
1065 *
1066 * This function returns %0 on success and a negative error code on failure.
1067 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001068static int unpack_lsave(const struct ubifs_info *c, void *buf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001069{
1070 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1071 int i, pos = 0, err;
1072
1073 err = check_lpt_type(&addr, &pos, UBIFS_LPT_LSAVE);
1074 if (err)
1075 return err;
1076 for (i = 0; i < c->lsave_cnt; i++) {
1077 int lnum = ubifs_unpack_bits(&addr, &pos, c->lnum_bits);
1078
1079 if (lnum < c->main_first || lnum >= c->leb_cnt)
1080 return -EINVAL;
1081 c->lsave[i] = lnum;
1082 }
1083 err = check_lpt_crc(buf, c->lsave_sz);
1084 return err;
1085}
1086
1087/**
1088 * validate_nnode - validate a nnode.
1089 * @c: UBIFS file-system description object
1090 * @nnode: nnode to validate
1091 * @parent: parent nnode (or NULL for the root nnode)
1092 * @iip: index in parent
1093 *
1094 * This function returns %0 on success and a negative error code on failure.
1095 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001096static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001097 struct ubifs_nnode *parent, int iip)
1098{
1099 int i, lvl, max_offs;
1100
1101 if (c->big_lpt) {
1102 int num = calc_nnode_num_from_parent(c, parent, iip);
1103
1104 if (nnode->num != num)
1105 return -EINVAL;
1106 }
1107 lvl = parent ? parent->level - 1 : c->lpt_hght;
1108 if (lvl < 1)
1109 return -EINVAL;
1110 if (lvl == 1)
1111 max_offs = c->leb_size - c->pnode_sz;
1112 else
1113 max_offs = c->leb_size - c->nnode_sz;
1114 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1115 int lnum = nnode->nbranch[i].lnum;
1116 int offs = nnode->nbranch[i].offs;
1117
1118 if (lnum == 0) {
1119 if (offs != 0)
1120 return -EINVAL;
1121 continue;
1122 }
1123 if (lnum < c->lpt_first || lnum > c->lpt_last)
1124 return -EINVAL;
1125 if (offs < 0 || offs > max_offs)
1126 return -EINVAL;
1127 }
1128 return 0;
1129}
1130
1131/**
1132 * validate_pnode - validate a pnode.
1133 * @c: UBIFS file-system description object
1134 * @pnode: pnode to validate
1135 * @parent: parent nnode
1136 * @iip: index in parent
1137 *
1138 * This function returns %0 on success and a negative error code on failure.
1139 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001140static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001141 struct ubifs_nnode *parent, int iip)
1142{
1143 int i;
1144
1145 if (c->big_lpt) {
1146 int num = calc_pnode_num_from_parent(c, parent, iip);
1147
1148 if (pnode->num != num)
1149 return -EINVAL;
1150 }
1151 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1152 int free = pnode->lprops[i].free;
1153 int dirty = pnode->lprops[i].dirty;
1154
1155 if (free < 0 || free > c->leb_size || free % c->min_io_size ||
1156 (free & 7))
1157 return -EINVAL;
1158 if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
1159 return -EINVAL;
1160 if (dirty + free > c->leb_size)
1161 return -EINVAL;
1162 }
1163 return 0;
1164}
1165
1166/**
1167 * set_pnode_lnum - set LEB numbers on a pnode.
1168 * @c: UBIFS file-system description object
1169 * @pnode: pnode to update
1170 *
1171 * This function calculates the LEB numbers for the LEB properties it contains
1172 * based on the pnode number.
1173 */
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001174static void set_pnode_lnum(const struct ubifs_info *c,
1175 struct ubifs_pnode *pnode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001176{
1177 int i, lnum;
1178
1179 lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
1180 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1181 if (lnum >= c->leb_cnt)
1182 return;
1183 pnode->lprops[i].lnum = lnum++;
1184 }
1185}
1186
1187/**
1188 * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
1189 * @c: UBIFS file-system description object
1190 * @parent: parent nnode (or NULL for the root)
1191 * @iip: index in parent
1192 *
1193 * This function returns %0 on success and a negative error code on failure.
1194 */
1195int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1196{
1197 struct ubifs_nbranch *branch = NULL;
1198 struct ubifs_nnode *nnode = NULL;
1199 void *buf = c->lpt_nod_buf;
1200 int err, lnum, offs;
1201
1202 if (parent) {
1203 branch = &parent->nbranch[iip];
1204 lnum = branch->lnum;
1205 offs = branch->offs;
1206 } else {
1207 lnum = c->lpt_lnum;
1208 offs = c->lpt_offs;
1209 }
1210 nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1211 if (!nnode) {
1212 err = -ENOMEM;
1213 goto out;
1214 }
1215 if (lnum == 0) {
1216 /*
1217 * This nnode was not written which just means that the LEB
1218 * properties in the subtree below it describe empty LEBs. We
1219 * make the nnode as though we had read it, which in fact means
1220 * doing almost nothing.
1221 */
1222 if (c->big_lpt)
1223 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1224 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001225 err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001226 if (err)
1227 goto out;
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001228 err = ubifs_unpack_nnode(c, buf, nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001229 if (err)
1230 goto out;
1231 }
1232 err = validate_nnode(c, nnode, parent, iip);
1233 if (err)
1234 goto out;
1235 if (!c->big_lpt)
1236 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1237 if (parent) {
1238 branch->nnode = nnode;
1239 nnode->level = parent->level - 1;
1240 } else {
1241 c->nroot = nnode;
1242 nnode->level = c->lpt_hght;
1243 }
1244 nnode->parent = parent;
1245 nnode->iip = iip;
1246 return 0;
1247
1248out:
1249 ubifs_err("error %d reading nnode at %d:%d", err, lnum, offs);
Artem Bityutskiybfcf6772011-05-24 14:10:03 +03001250 dbg_dump_stack();
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001251 kfree(nnode);
1252 return err;
1253}
1254
1255/**
1256 * read_pnode - read a pnode from flash and link it to the tree in memory.
1257 * @c: UBIFS file-system description object
1258 * @parent: parent nnode
1259 * @iip: index in parent
1260 *
1261 * This function returns %0 on success and a negative error code on failure.
1262 */
1263static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1264{
1265 struct ubifs_nbranch *branch;
1266 struct ubifs_pnode *pnode = NULL;
1267 void *buf = c->lpt_nod_buf;
1268 int err, lnum, offs;
1269
1270 branch = &parent->nbranch[iip];
1271 lnum = branch->lnum;
1272 offs = branch->offs;
1273 pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
Artem Bityutskiy54acbaa2011-03-25 19:09:54 +02001274 if (!pnode)
1275 return -ENOMEM;
1276
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001277 if (lnum == 0) {
1278 /*
1279 * This pnode was not written which just means that the LEB
1280 * properties in it describe empty LEBs. We make the pnode as
1281 * though we had read it.
1282 */
1283 int i;
1284
1285 if (c->big_lpt)
1286 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1287 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1288 struct ubifs_lprops * const lprops = &pnode->lprops[i];
1289
1290 lprops->free = c->leb_size;
1291 lprops->flags = ubifs_categorize_lprops(c, lprops);
1292 }
1293 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001294 err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001295 if (err)
1296 goto out;
1297 err = unpack_pnode(c, buf, pnode);
1298 if (err)
1299 goto out;
1300 }
1301 err = validate_pnode(c, pnode, parent, iip);
1302 if (err)
1303 goto out;
1304 if (!c->big_lpt)
1305 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1306 branch->pnode = pnode;
1307 pnode->parent = parent;
1308 pnode->iip = iip;
1309 set_pnode_lnum(c, pnode);
1310 c->pnodes_have += 1;
1311 return 0;
1312
1313out:
1314 ubifs_err("error %d reading pnode at %d:%d", err, lnum, offs);
1315 dbg_dump_pnode(c, pnode, parent, iip);
Artem Bityutskiybfcf6772011-05-24 14:10:03 +03001316 dbg_dump_stack();
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001317 dbg_msg("calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
1318 kfree(pnode);
1319 return err;
1320}
1321
1322/**
1323 * read_ltab - read LPT's own lprops table.
1324 * @c: UBIFS file-system description object
1325 *
1326 * This function returns %0 on success and a negative error code on failure.
1327 */
1328static int read_ltab(struct ubifs_info *c)
1329{
1330 int err;
1331 void *buf;
1332
1333 buf = vmalloc(c->ltab_sz);
1334 if (!buf)
1335 return -ENOMEM;
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001336 err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001337 if (err)
1338 goto out;
1339 err = unpack_ltab(c, buf);
1340out:
1341 vfree(buf);
1342 return err;
1343}
1344
1345/**
1346 * read_lsave - read LPT's save table.
1347 * @c: UBIFS file-system description object
1348 *
1349 * This function returns %0 on success and a negative error code on failure.
1350 */
1351static int read_lsave(struct ubifs_info *c)
1352{
1353 int err, i;
1354 void *buf;
1355
1356 buf = vmalloc(c->lsave_sz);
1357 if (!buf)
1358 return -ENOMEM;
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001359 err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs,
1360 c->lsave_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001361 if (err)
1362 goto out;
1363 err = unpack_lsave(c, buf);
1364 if (err)
1365 goto out;
1366 for (i = 0; i < c->lsave_cnt; i++) {
1367 int lnum = c->lsave[i];
Vasiliy Kulikov0e54c892010-09-05 22:33:00 +04001368 struct ubifs_lprops *lprops;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001369
1370 /*
1371 * Due to automatic resizing, the values in the lsave table
1372 * could be beyond the volume size - just ignore them.
1373 */
1374 if (lnum >= c->leb_cnt)
1375 continue;
Vasiliy Kulikov0e54c892010-09-05 22:33:00 +04001376 lprops = ubifs_lpt_lookup(c, lnum);
1377 if (IS_ERR(lprops)) {
1378 err = PTR_ERR(lprops);
1379 goto out;
1380 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001381 }
1382out:
1383 vfree(buf);
1384 return err;
1385}
1386
1387/**
1388 * ubifs_get_nnode - get a nnode.
1389 * @c: UBIFS file-system description object
1390 * @parent: parent nnode (or NULL for the root)
1391 * @iip: index in parent
1392 *
1393 * This function returns a pointer to the nnode on success or a negative error
1394 * code on failure.
1395 */
1396struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
1397 struct ubifs_nnode *parent, int iip)
1398{
1399 struct ubifs_nbranch *branch;
1400 struct ubifs_nnode *nnode;
1401 int err;
1402
1403 branch = &parent->nbranch[iip];
1404 nnode = branch->nnode;
1405 if (nnode)
1406 return nnode;
1407 err = ubifs_read_nnode(c, parent, iip);
1408 if (err)
1409 return ERR_PTR(err);
1410 return branch->nnode;
1411}
1412
1413/**
1414 * ubifs_get_pnode - get a pnode.
1415 * @c: UBIFS file-system description object
1416 * @parent: parent nnode
1417 * @iip: index in parent
1418 *
1419 * This function returns a pointer to the pnode on success or a negative error
1420 * code on failure.
1421 */
1422struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
1423 struct ubifs_nnode *parent, int iip)
1424{
1425 struct ubifs_nbranch *branch;
1426 struct ubifs_pnode *pnode;
1427 int err;
1428
1429 branch = &parent->nbranch[iip];
1430 pnode = branch->pnode;
1431 if (pnode)
1432 return pnode;
1433 err = read_pnode(c, parent, iip);
1434 if (err)
1435 return ERR_PTR(err);
1436 update_cats(c, branch->pnode);
1437 return branch->pnode;
1438}
1439
1440/**
1441 * ubifs_lpt_lookup - lookup LEB properties in the LPT.
1442 * @c: UBIFS file-system description object
1443 * @lnum: LEB number to lookup
1444 *
1445 * This function returns a pointer to the LEB properties on success or a
1446 * negative error code on failure.
1447 */
1448struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
1449{
1450 int err, i, h, iip, shft;
1451 struct ubifs_nnode *nnode;
1452 struct ubifs_pnode *pnode;
1453
1454 if (!c->nroot) {
1455 err = ubifs_read_nnode(c, NULL, 0);
1456 if (err)
1457 return ERR_PTR(err);
1458 }
1459 nnode = c->nroot;
1460 i = lnum - c->main_first;
1461 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1462 for (h = 1; h < c->lpt_hght; h++) {
1463 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1464 shft -= UBIFS_LPT_FANOUT_SHIFT;
1465 nnode = ubifs_get_nnode(c, nnode, iip);
1466 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001467 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001468 }
1469 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1470 shft -= UBIFS_LPT_FANOUT_SHIFT;
1471 pnode = ubifs_get_pnode(c, nnode, iip);
1472 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001473 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001474 iip = (i & (UBIFS_LPT_FANOUT - 1));
1475 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1476 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1477 pnode->lprops[iip].flags);
1478 return &pnode->lprops[iip];
1479}
1480
1481/**
1482 * dirty_cow_nnode - ensure a nnode is not being committed.
1483 * @c: UBIFS file-system description object
1484 * @nnode: nnode to check
1485 *
1486 * Returns dirtied nnode on success or negative error code on failure.
1487 */
1488static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
1489 struct ubifs_nnode *nnode)
1490{
1491 struct ubifs_nnode *n;
1492 int i;
1493
1494 if (!test_bit(COW_CNODE, &nnode->flags)) {
1495 /* nnode is not being committed */
1496 if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
1497 c->dirty_nn_cnt += 1;
1498 ubifs_add_nnode_dirt(c, nnode);
1499 }
1500 return nnode;
1501 }
1502
1503 /* nnode is being committed, so copy it */
1504 n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1505 if (unlikely(!n))
1506 return ERR_PTR(-ENOMEM);
1507
1508 memcpy(n, nnode, sizeof(struct ubifs_nnode));
1509 n->cnext = NULL;
1510 __set_bit(DIRTY_CNODE, &n->flags);
1511 __clear_bit(COW_CNODE, &n->flags);
1512
1513 /* The children now have new parent */
1514 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1515 struct ubifs_nbranch *branch = &n->nbranch[i];
1516
1517 if (branch->cnode)
1518 branch->cnode->parent = n;
1519 }
1520
1521 ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
1522 __set_bit(OBSOLETE_CNODE, &nnode->flags);
1523
1524 c->dirty_nn_cnt += 1;
1525 ubifs_add_nnode_dirt(c, nnode);
1526 if (nnode->parent)
1527 nnode->parent->nbranch[n->iip].nnode = n;
1528 else
1529 c->nroot = n;
1530 return n;
1531}
1532
1533/**
1534 * dirty_cow_pnode - ensure a pnode is not being committed.
1535 * @c: UBIFS file-system description object
1536 * @pnode: pnode to check
1537 *
1538 * Returns dirtied pnode on success or negative error code on failure.
1539 */
1540static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
1541 struct ubifs_pnode *pnode)
1542{
1543 struct ubifs_pnode *p;
1544
1545 if (!test_bit(COW_CNODE, &pnode->flags)) {
1546 /* pnode is not being committed */
1547 if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
1548 c->dirty_pn_cnt += 1;
1549 add_pnode_dirt(c, pnode);
1550 }
1551 return pnode;
1552 }
1553
1554 /* pnode is being committed, so copy it */
1555 p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1556 if (unlikely(!p))
1557 return ERR_PTR(-ENOMEM);
1558
1559 memcpy(p, pnode, sizeof(struct ubifs_pnode));
1560 p->cnext = NULL;
1561 __set_bit(DIRTY_CNODE, &p->flags);
1562 __clear_bit(COW_CNODE, &p->flags);
1563 replace_cats(c, pnode, p);
1564
1565 ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
1566 __set_bit(OBSOLETE_CNODE, &pnode->flags);
1567
1568 c->dirty_pn_cnt += 1;
1569 add_pnode_dirt(c, pnode);
1570 pnode->parent->nbranch[p->iip].pnode = p;
1571 return p;
1572}
1573
1574/**
1575 * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
1576 * @c: UBIFS file-system description object
1577 * @lnum: LEB number to lookup
1578 *
1579 * This function returns a pointer to the LEB properties on success or a
1580 * negative error code on failure.
1581 */
1582struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
1583{
1584 int err, i, h, iip, shft;
1585 struct ubifs_nnode *nnode;
1586 struct ubifs_pnode *pnode;
1587
1588 if (!c->nroot) {
1589 err = ubifs_read_nnode(c, NULL, 0);
1590 if (err)
1591 return ERR_PTR(err);
1592 }
1593 nnode = c->nroot;
1594 nnode = dirty_cow_nnode(c, nnode);
1595 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001596 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001597 i = lnum - c->main_first;
1598 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1599 for (h = 1; h < c->lpt_hght; h++) {
1600 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1601 shft -= UBIFS_LPT_FANOUT_SHIFT;
1602 nnode = ubifs_get_nnode(c, nnode, iip);
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 nnode = dirty_cow_nnode(c, nnode);
1606 if (IS_ERR(nnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001607 return ERR_CAST(nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001608 }
1609 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1610 shft -= UBIFS_LPT_FANOUT_SHIFT;
1611 pnode = ubifs_get_pnode(c, nnode, iip);
1612 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001613 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001614 pnode = dirty_cow_pnode(c, pnode);
1615 if (IS_ERR(pnode))
Julia Lawall6da51562010-05-22 12:00:21 +02001616 return ERR_CAST(pnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001617 iip = (i & (UBIFS_LPT_FANOUT - 1));
1618 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1619 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1620 pnode->lprops[iip].flags);
1621 ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
1622 return &pnode->lprops[iip];
1623}
1624
1625/**
1626 * lpt_init_rd - initialize the LPT for reading.
1627 * @c: UBIFS file-system description object
1628 *
1629 * This function returns %0 on success and a negative error code on failure.
1630 */
1631static int lpt_init_rd(struct ubifs_info *c)
1632{
1633 int err, i;
1634
1635 c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1636 if (!c->ltab)
1637 return -ENOMEM;
1638
1639 i = max_t(int, c->nnode_sz, c->pnode_sz);
1640 c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
1641 if (!c->lpt_nod_buf)
1642 return -ENOMEM;
1643
1644 for (i = 0; i < LPROPS_HEAP_CNT; i++) {
1645 c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
1646 GFP_KERNEL);
1647 if (!c->lpt_heap[i].arr)
1648 return -ENOMEM;
1649 c->lpt_heap[i].cnt = 0;
1650 c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
1651 }
1652
1653 c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
1654 if (!c->dirty_idx.arr)
1655 return -ENOMEM;
1656 c->dirty_idx.cnt = 0;
1657 c->dirty_idx.max_cnt = LPT_HEAP_SZ;
1658
1659 err = read_ltab(c);
1660 if (err)
1661 return err;
1662
1663 dbg_lp("space_bits %d", c->space_bits);
1664 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
1665 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
1666 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
1667 dbg_lp("pcnt_bits %d", c->pcnt_bits);
1668 dbg_lp("lnum_bits %d", c->lnum_bits);
1669 dbg_lp("pnode_sz %d", c->pnode_sz);
1670 dbg_lp("nnode_sz %d", c->nnode_sz);
1671 dbg_lp("ltab_sz %d", c->ltab_sz);
1672 dbg_lp("lsave_sz %d", c->lsave_sz);
1673 dbg_lp("lsave_cnt %d", c->lsave_cnt);
1674 dbg_lp("lpt_hght %d", c->lpt_hght);
1675 dbg_lp("big_lpt %d", c->big_lpt);
1676 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
1677 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
1678 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
1679 if (c->big_lpt)
1680 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
1681
1682 return 0;
1683}
1684
1685/**
1686 * lpt_init_wr - initialize the LPT for writing.
1687 * @c: UBIFS file-system description object
1688 *
1689 * 'lpt_init_rd()' must have been called already.
1690 *
1691 * This function returns %0 on success and a negative error code on failure.
1692 */
1693static int lpt_init_wr(struct ubifs_info *c)
1694{
1695 int err, i;
1696
1697 c->ltab_cmt = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1698 if (!c->ltab_cmt)
1699 return -ENOMEM;
1700
1701 c->lpt_buf = vmalloc(c->leb_size);
1702 if (!c->lpt_buf)
1703 return -ENOMEM;
1704
1705 if (c->big_lpt) {
1706 c->lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_NOFS);
1707 if (!c->lsave)
1708 return -ENOMEM;
1709 err = read_lsave(c);
1710 if (err)
1711 return err;
1712 }
1713
1714 for (i = 0; i < c->lpt_lebs; i++)
1715 if (c->ltab[i].free == c->leb_size) {
1716 err = ubifs_leb_unmap(c, i + c->lpt_first);
1717 if (err)
1718 return err;
1719 }
1720
1721 return 0;
1722}
1723
1724/**
1725 * ubifs_lpt_init - initialize the LPT.
1726 * @c: UBIFS file-system description object
1727 * @rd: whether to initialize lpt for reading
1728 * @wr: whether to initialize lpt for writing
1729 *
1730 * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
1731 * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
1732 * true.
1733 *
1734 * This function returns %0 on success and a negative error code on failure.
1735 */
1736int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
1737{
1738 int err;
1739
1740 if (rd) {
1741 err = lpt_init_rd(c);
1742 if (err)
1743 return err;
1744 }
1745
1746 if (wr) {
1747 err = lpt_init_wr(c);
1748 if (err)
1749 return err;
1750 }
1751
1752 return 0;
1753}
1754
1755/**
1756 * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
1757 * @nnode: where to keep a nnode
1758 * @pnode: where to keep a pnode
1759 * @cnode: where to keep a cnode
1760 * @in_tree: is the node in the tree in memory
1761 * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
1762 * the tree
1763 * @ptr.pnode: ditto for pnode
1764 * @ptr.cnode: ditto for cnode
1765 */
1766struct lpt_scan_node {
1767 union {
1768 struct ubifs_nnode nnode;
1769 struct ubifs_pnode pnode;
1770 struct ubifs_cnode cnode;
1771 };
1772 int in_tree;
1773 union {
1774 struct ubifs_nnode *nnode;
1775 struct ubifs_pnode *pnode;
1776 struct ubifs_cnode *cnode;
1777 } ptr;
1778};
1779
1780/**
1781 * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
1782 * @c: the UBIFS file-system description object
1783 * @path: where to put the nnode
1784 * @parent: parent of the nnode
1785 * @iip: index in parent of the nnode
1786 *
1787 * This function returns a pointer to the nnode on success or a negative error
1788 * code on failure.
1789 */
1790static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
1791 struct lpt_scan_node *path,
1792 struct ubifs_nnode *parent, int iip)
1793{
1794 struct ubifs_nbranch *branch;
1795 struct ubifs_nnode *nnode;
1796 void *buf = c->lpt_nod_buf;
1797 int err;
1798
1799 branch = &parent->nbranch[iip];
1800 nnode = branch->nnode;
1801 if (nnode) {
1802 path->in_tree = 1;
1803 path->ptr.nnode = nnode;
1804 return nnode;
1805 }
1806 nnode = &path->nnode;
1807 path->in_tree = 0;
1808 path->ptr.nnode = nnode;
1809 memset(nnode, 0, sizeof(struct ubifs_nnode));
1810 if (branch->lnum == 0) {
1811 /*
1812 * This nnode was not written which just means that the LEB
1813 * properties in the subtree below it describe empty LEBs. We
1814 * make the nnode as though we had read it, which in fact means
1815 * doing almost nothing.
1816 */
1817 if (c->big_lpt)
1818 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1819 } else {
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001820 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1821 c->nnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001822 if (err)
1823 return ERR_PTR(err);
Artem Bityutskiy2ba5f7a2008-10-31 17:32:30 +02001824 err = ubifs_unpack_nnode(c, buf, nnode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001825 if (err)
1826 return ERR_PTR(err);
1827 }
1828 err = validate_nnode(c, nnode, parent, iip);
1829 if (err)
1830 return ERR_PTR(err);
1831 if (!c->big_lpt)
1832 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1833 nnode->level = parent->level - 1;
1834 nnode->parent = parent;
1835 nnode->iip = iip;
1836 return nnode;
1837}
1838
1839/**
1840 * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
1841 * @c: the UBIFS file-system description object
1842 * @path: where to put the pnode
1843 * @parent: parent of the pnode
1844 * @iip: index in parent of the pnode
1845 *
1846 * This function returns a pointer to the pnode on success or a negative error
1847 * code on failure.
1848 */
1849static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
1850 struct lpt_scan_node *path,
1851 struct ubifs_nnode *parent, int iip)
1852{
1853 struct ubifs_nbranch *branch;
1854 struct ubifs_pnode *pnode;
1855 void *buf = c->lpt_nod_buf;
1856 int err;
1857
1858 branch = &parent->nbranch[iip];
1859 pnode = branch->pnode;
1860 if (pnode) {
1861 path->in_tree = 1;
1862 path->ptr.pnode = pnode;
1863 return pnode;
1864 }
1865 pnode = &path->pnode;
1866 path->in_tree = 0;
1867 path->ptr.pnode = pnode;
1868 memset(pnode, 0, sizeof(struct ubifs_pnode));
1869 if (branch->lnum == 0) {
1870 /*
1871 * This pnode was not written which just means that the LEB
1872 * properties in it describe empty LEBs. We make the pnode as
1873 * though we had read it.
1874 */
1875 int i;
1876
1877 if (c->big_lpt)
1878 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1879 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1880 struct ubifs_lprops * const lprops = &pnode->lprops[i];
1881
1882 lprops->free = c->leb_size;
1883 lprops->flags = ubifs_categorize_lprops(c, lprops);
1884 }
1885 } else {
1886 ubifs_assert(branch->lnum >= c->lpt_first &&
1887 branch->lnum <= c->lpt_last);
1888 ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
Artem Bityutskiyd3048202011-06-03 14:03:25 +03001889 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1890 c->pnode_sz, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001891 if (err)
1892 return ERR_PTR(err);
1893 err = unpack_pnode(c, buf, pnode);
1894 if (err)
1895 return ERR_PTR(err);
1896 }
1897 err = validate_pnode(c, pnode, parent, iip);
1898 if (err)
1899 return ERR_PTR(err);
1900 if (!c->big_lpt)
1901 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1902 pnode->parent = parent;
1903 pnode->iip = iip;
1904 set_pnode_lnum(c, pnode);
1905 return pnode;
1906}
1907
1908/**
1909 * ubifs_lpt_scan_nolock - scan the LPT.
1910 * @c: the UBIFS file-system description object
1911 * @start_lnum: LEB number from which to start scanning
1912 * @end_lnum: LEB number at which to stop scanning
1913 * @scan_cb: callback function called for each lprops
1914 * @data: data to be passed to the callback function
1915 *
1916 * This function returns %0 on success and a negative error code on failure.
1917 */
1918int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
1919 ubifs_lpt_scan_callback scan_cb, void *data)
1920{
1921 int err = 0, i, h, iip, shft;
1922 struct ubifs_nnode *nnode;
1923 struct ubifs_pnode *pnode;
1924 struct lpt_scan_node *path;
1925
1926 if (start_lnum == -1) {
1927 start_lnum = end_lnum + 1;
1928 if (start_lnum >= c->leb_cnt)
1929 start_lnum = c->main_first;
1930 }
1931
1932 ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
1933 ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
1934
1935 if (!c->nroot) {
1936 err = ubifs_read_nnode(c, NULL, 0);
1937 if (err)
1938 return err;
1939 }
1940
1941 path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
1942 GFP_NOFS);
1943 if (!path)
1944 return -ENOMEM;
1945
1946 path[0].ptr.nnode = c->nroot;
1947 path[0].in_tree = 1;
1948again:
1949 /* Descend to the pnode containing start_lnum */
1950 nnode = c->nroot;
1951 i = start_lnum - c->main_first;
1952 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1953 for (h = 1; h < c->lpt_hght; h++) {
1954 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1955 shft -= UBIFS_LPT_FANOUT_SHIFT;
1956 nnode = scan_get_nnode(c, path + h, nnode, iip);
1957 if (IS_ERR(nnode)) {
1958 err = PTR_ERR(nnode);
1959 goto out;
1960 }
1961 }
1962 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1963 shft -= UBIFS_LPT_FANOUT_SHIFT;
1964 pnode = scan_get_pnode(c, path + h, nnode, iip);
1965 if (IS_ERR(pnode)) {
1966 err = PTR_ERR(pnode);
1967 goto out;
1968 }
1969 iip = (i & (UBIFS_LPT_FANOUT - 1));
1970
1971 /* Loop for each lprops */
1972 while (1) {
1973 struct ubifs_lprops *lprops = &pnode->lprops[iip];
1974 int ret, lnum = lprops->lnum;
1975
1976 ret = scan_cb(c, lprops, path[h].in_tree, data);
1977 if (ret < 0) {
1978 err = ret;
1979 goto out;
1980 }
1981 if (ret & LPT_SCAN_ADD) {
1982 /* Add all the nodes in path to the tree in memory */
1983 for (h = 1; h < c->lpt_hght; h++) {
1984 const size_t sz = sizeof(struct ubifs_nnode);
1985 struct ubifs_nnode *parent;
1986
1987 if (path[h].in_tree)
1988 continue;
1989 nnode = kmalloc(sz, GFP_NOFS);
1990 if (!nnode) {
1991 err = -ENOMEM;
1992 goto out;
1993 }
1994 memcpy(nnode, &path[h].nnode, sz);
1995 parent = nnode->parent;
1996 parent->nbranch[nnode->iip].nnode = nnode;
1997 path[h].ptr.nnode = nnode;
1998 path[h].in_tree = 1;
1999 path[h + 1].cnode.parent = nnode;
2000 }
2001 if (path[h].in_tree)
2002 ubifs_ensure_cat(c, lprops);
2003 else {
2004 const size_t sz = sizeof(struct ubifs_pnode);
2005 struct ubifs_nnode *parent;
2006
2007 pnode = kmalloc(sz, GFP_NOFS);
2008 if (!pnode) {
2009 err = -ENOMEM;
2010 goto out;
2011 }
2012 memcpy(pnode, &path[h].pnode, sz);
2013 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
2085#ifdef CONFIG_UBIFS_FS_DEBUG
2086
2087/**
2088 * dbg_chk_pnode - check a pnode.
2089 * @c: the UBIFS file-system description object
2090 * @pnode: pnode to check
2091 * @col: pnode column
2092 *
2093 * This function returns %0 on success and a negative error code on failure.
2094 */
2095static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
2096 int col)
2097{
2098 int i;
2099
2100 if (pnode->num != col) {
2101 dbg_err("pnode num %d expected %d parent num %d iip %d",
2102 pnode->num, col, pnode->parent->num, pnode->iip);
2103 return -EINVAL;
2104 }
2105 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2106 struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
2107 int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
2108 c->main_first;
2109 int found, cat = lprops->flags & LPROPS_CAT_MASK;
2110 struct ubifs_lpt_heap *heap;
2111 struct list_head *list = NULL;
2112
2113 if (lnum >= c->leb_cnt)
2114 continue;
2115 if (lprops->lnum != lnum) {
2116 dbg_err("bad LEB number %d expected %d",
2117 lprops->lnum, lnum);
2118 return -EINVAL;
2119 }
2120 if (lprops->flags & LPROPS_TAKEN) {
2121 if (cat != LPROPS_UNCAT) {
2122 dbg_err("LEB %d taken but not uncat %d",
2123 lprops->lnum, cat);
2124 return -EINVAL;
2125 }
2126 continue;
2127 }
2128 if (lprops->flags & LPROPS_INDEX) {
2129 switch (cat) {
2130 case LPROPS_UNCAT:
2131 case LPROPS_DIRTY_IDX:
2132 case LPROPS_FRDI_IDX:
2133 break;
2134 default:
2135 dbg_err("LEB %d index but cat %d",
2136 lprops->lnum, cat);
2137 return -EINVAL;
2138 }
2139 } else {
2140 switch (cat) {
2141 case LPROPS_UNCAT:
2142 case LPROPS_DIRTY:
2143 case LPROPS_FREE:
2144 case LPROPS_EMPTY:
2145 case LPROPS_FREEABLE:
2146 break;
2147 default:
2148 dbg_err("LEB %d not index but cat %d",
2149 lprops->lnum, cat);
2150 return -EINVAL;
2151 }
2152 }
2153 switch (cat) {
2154 case LPROPS_UNCAT:
2155 list = &c->uncat_list;
2156 break;
2157 case LPROPS_EMPTY:
2158 list = &c->empty_list;
2159 break;
2160 case LPROPS_FREEABLE:
2161 list = &c->freeable_list;
2162 break;
2163 case LPROPS_FRDI_IDX:
2164 list = &c->frdi_idx_list;
2165 break;
2166 }
2167 found = 0;
2168 switch (cat) {
2169 case LPROPS_DIRTY:
2170 case LPROPS_DIRTY_IDX:
2171 case LPROPS_FREE:
2172 heap = &c->lpt_heap[cat - 1];
2173 if (lprops->hpos < heap->cnt &&
2174 heap->arr[lprops->hpos] == lprops)
2175 found = 1;
2176 break;
2177 case LPROPS_UNCAT:
2178 case LPROPS_EMPTY:
2179 case LPROPS_FREEABLE:
2180 case LPROPS_FRDI_IDX:
2181 list_for_each_entry(lp, list, list)
2182 if (lprops == lp) {
2183 found = 1;
2184 break;
2185 }
2186 break;
2187 }
2188 if (!found) {
2189 dbg_err("LEB %d cat %d not found in cat heap/list",
2190 lprops->lnum, cat);
2191 return -EINVAL;
2192 }
2193 switch (cat) {
2194 case LPROPS_EMPTY:
2195 if (lprops->free != c->leb_size) {
2196 dbg_err("LEB %d cat %d free %d dirty %d",
2197 lprops->lnum, cat, lprops->free,
2198 lprops->dirty);
2199 return -EINVAL;
2200 }
2201 case LPROPS_FREEABLE:
2202 case LPROPS_FRDI_IDX:
2203 if (lprops->free + lprops->dirty != c->leb_size) {
2204 dbg_err("LEB %d cat %d free %d dirty %d",
2205 lprops->lnum, cat, lprops->free,
2206 lprops->dirty);
2207 return -EINVAL;
2208 }
2209 }
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) {
2240 dbg_err("nnode num %d expected %d "
2241 "parent num %d iip %d", cnode->num, num,
2242 (nnode ? nnode->num : 0), cnode->iip);
2243 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}
2279
2280#endif /* CONFIG_UBIFS_FS_DEBUG */