1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
7 * Authors: Adrian Hunter
8 * Artem Bityutskiy (Битюцкий Артём)
9 */
10
11 /*
12 * This file implements the LEB properties tree (LPT) area. The LPT area
13 * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
14 * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
15 * between the log and the orphan area.
16 *
17 * The LPT area is like a miniature self-contained file system. It is required
18 * that it never runs out of space, is fast to access and update, and scales
19 * logarithmically. The LEB properties tree is implemented as a wandering tree
20 * much like the TNC, and the LPT area has its own garbage collection.
21 *
22 * The LPT has two slightly different forms called the "small model" and the
23 * "big model". The small model is used when the entire LEB properties table
24 * can be written into a single eraseblock. In that case, garbage collection
25 * consists of just writing the whole table, which therefore makes all other
26 * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
27 * selected for garbage collection, which consists of marking the clean nodes in
28 * that LEB as dirty, and then only the dirty nodes are written out. Also, in
29 * the case of the big model, a table of LEB numbers is saved so that the entire
30 * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
31 * mounted.
32 */
33
34 #include "ubifs.h"
35 #include <linux/crc16.h>
36 #include <linux/math64.h>
37 #include <linux/slab.h>
38
39 /**
40 * do_calc_lpt_geom - calculate sizes for the LPT area.
41 * @c: the UBIFS file-system description object
42 *
43 * Calculate the sizes of LPT bit fields, nodes, and tree, based on the
44 * properties of the flash and whether LPT is "big" (c->big_lpt).
45 */
do_calc_lpt_geom(struct ubifs_info * c)46 static void do_calc_lpt_geom(struct ubifs_info *c)
47 {
48 int i, n, bits, per_leb_wastage, max_pnode_cnt;
49 long long sz, tot_wastage;
50
51 n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
52 max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
53
54 c->lpt_hght = 1;
55 n = UBIFS_LPT_FANOUT;
56 while (n < max_pnode_cnt) {
57 c->lpt_hght += 1;
58 n <<= UBIFS_LPT_FANOUT_SHIFT;
59 }
60
61 c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
62
63 n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
64 c->nnode_cnt = n;
65 for (i = 1; i < c->lpt_hght; i++) {
66 n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
67 c->nnode_cnt += n;
68 }
69
70 c->space_bits = fls(c->leb_size) - 3;
71 c->lpt_lnum_bits = fls(c->lpt_lebs);
72 c->lpt_offs_bits = fls(c->leb_size - 1);
73 c->lpt_spc_bits = fls(c->leb_size);
74
75 n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
76 c->pcnt_bits = fls(n - 1);
77
78 c->lnum_bits = fls(c->max_leb_cnt - 1);
79
80 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
81 (c->big_lpt ? c->pcnt_bits : 0) +
82 (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
83 c->pnode_sz = (bits + 7) / 8;
84
85 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
86 (c->big_lpt ? c->pcnt_bits : 0) +
87 (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
88 c->nnode_sz = (bits + 7) / 8;
89
90 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
91 c->lpt_lebs * c->lpt_spc_bits * 2;
92 c->ltab_sz = (bits + 7) / 8;
93
94 bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
95 c->lnum_bits * c->lsave_cnt;
96 c->lsave_sz = (bits + 7) / 8;
97
98 /* Calculate the minimum LPT size */
99 c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
100 c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
101 c->lpt_sz += c->ltab_sz;
102 if (c->big_lpt)
103 c->lpt_sz += c->lsave_sz;
104
105 /* Add wastage */
106 sz = c->lpt_sz;
107 per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
108 sz += per_leb_wastage;
109 tot_wastage = per_leb_wastage;
110 while (sz > c->leb_size) {
111 sz += per_leb_wastage;
112 sz -= c->leb_size;
113 tot_wastage += per_leb_wastage;
114 }
115 tot_wastage += ALIGN(sz, c->min_io_size) - sz;
116 c->lpt_sz += tot_wastage;
117 }
118
119 /**
120 * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
121 * @c: the UBIFS file-system description object
122 *
123 * This function returns %0 on success and a negative error code on failure.
124 */
ubifs_calc_lpt_geom(struct ubifs_info * c)125 int ubifs_calc_lpt_geom(struct ubifs_info *c)
126 {
127 int lebs_needed;
128 long long sz;
129
130 do_calc_lpt_geom(c);
131
132 /* Verify that lpt_lebs is big enough */
133 sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
134 lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
135 if (lebs_needed > c->lpt_lebs) {
136 ubifs_err(c, "too few LPT LEBs");
137 return -EINVAL;
138 }
139
140 /* Verify that ltab fits in a single LEB (since ltab is a single node */
141 if (c->ltab_sz > c->leb_size) {
142 ubifs_err(c, "LPT ltab too big");
143 return -EINVAL;
144 }
145
146 c->check_lpt_free = c->big_lpt;
147 return 0;
148 }
149
150 /**
151 * calc_dflt_lpt_geom - calculate default LPT geometry.
152 * @c: the UBIFS file-system description object
153 * @main_lebs: number of main area LEBs is passed and returned here
154 * @big_lpt: whether the LPT area is "big" is returned here
155 *
156 * The size of the LPT area depends on parameters that themselves are dependent
157 * on the size of the LPT area. This function, successively recalculates the LPT
158 * area geometry until the parameters and resultant geometry are consistent.
159 *
160 * This function returns %0 on success and a negative error code on failure.
161 */
calc_dflt_lpt_geom(struct ubifs_info * c,int * main_lebs,int * big_lpt)162 static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
163 int *big_lpt)
164 {
165 int i, lebs_needed;
166 long long sz;
167
168 /* Start by assuming the minimum number of LPT LEBs */
169 c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
170 c->main_lebs = *main_lebs - c->lpt_lebs;
171 if (c->main_lebs <= 0)
172 return -EINVAL;
173
174 /* And assume we will use the small LPT model */
175 c->big_lpt = 0;
176
177 /*
178 * Calculate the geometry based on assumptions above and then see if it
179 * makes sense
180 */
181 do_calc_lpt_geom(c);
182
183 /* Small LPT model must have lpt_sz < leb_size */
184 if (c->lpt_sz > c->leb_size) {
185 /* Nope, so try again using big LPT model */
186 c->big_lpt = 1;
187 do_calc_lpt_geom(c);
188 }
189
190 /* Now check there are enough LPT LEBs */
191 for (i = 0; i < 64 ; i++) {
192 sz = c->lpt_sz * 4; /* Allow 4 times the size */
193 lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
194 if (lebs_needed > c->lpt_lebs) {
195 /* Not enough LPT LEBs so try again with more */
196 c->lpt_lebs = lebs_needed;
197 c->main_lebs = *main_lebs - c->lpt_lebs;
198 if (c->main_lebs <= 0)
199 return -EINVAL;
200 do_calc_lpt_geom(c);
201 continue;
202 }
203 if (c->ltab_sz > c->leb_size) {
204 ubifs_err(c, "LPT ltab too big");
205 return -EINVAL;
206 }
207 *main_lebs = c->main_lebs;
208 *big_lpt = c->big_lpt;
209 return 0;
210 }
211 return -EINVAL;
212 }
213
214 /**
215 * pack_bits - pack bit fields end-to-end.
216 * @c: UBIFS file-system description object
217 * @addr: address at which to pack (passed and next address returned)
218 * @pos: bit position at which to pack (passed and next position returned)
219 * @val: value to pack
220 * @nrbits: number of bits of value to pack (1-32)
221 */
pack_bits(const struct ubifs_info * c,uint8_t ** addr,int * pos,uint32_t val,int nrbits)222 static void pack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos, uint32_t val, int nrbits)
223 {
224 uint8_t *p = *addr;
225 int b = *pos;
226
227 ubifs_assert(c, nrbits > 0);
228 ubifs_assert(c, nrbits <= 32);
229 ubifs_assert(c, *pos >= 0);
230 ubifs_assert(c, *pos < 8);
231 ubifs_assert(c, (val >> nrbits) == 0 || nrbits == 32);
232 if (b) {
233 *p |= ((uint8_t)val) << b;
234 nrbits += b;
235 if (nrbits > 8) {
236 *++p = (uint8_t)(val >>= (8 - b));
237 if (nrbits > 16) {
238 *++p = (uint8_t)(val >>= 8);
239 if (nrbits > 24) {
240 *++p = (uint8_t)(val >>= 8);
241 if (nrbits > 32)
242 *++p = (uint8_t)(val >>= 8);
243 }
244 }
245 }
246 } else {
247 *p = (uint8_t)val;
248 if (nrbits > 8) {
249 *++p = (uint8_t)(val >>= 8);
250 if (nrbits > 16) {
251 *++p = (uint8_t)(val >>= 8);
252 if (nrbits > 24)
253 *++p = (uint8_t)(val >>= 8);
254 }
255 }
256 }
257 b = nrbits & 7;
258 if (b == 0)
259 p++;
260 *addr = p;
261 *pos = b;
262 }
263
264 /**
265 * ubifs_unpack_bits - unpack bit fields.
266 * @c: UBIFS file-system description object
267 * @addr: address at which to unpack (passed and next address returned)
268 * @pos: bit position at which to unpack (passed and next position returned)
269 * @nrbits: number of bits of value to unpack (1-32)
270 *
271 * This functions returns the value unpacked.
272 */
ubifs_unpack_bits(const struct ubifs_info * c,uint8_t ** addr,int * pos,int nrbits)273 uint32_t ubifs_unpack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos, int nrbits)
274 {
275 const int k = 32 - nrbits;
276 uint8_t *p = *addr;
277 int b = *pos;
278 uint32_t val;
279 const int bytes = (nrbits + b + 7) >> 3;
280
281 ubifs_assert(c, nrbits > 0);
282 ubifs_assert(c, nrbits <= 32);
283 ubifs_assert(c, *pos >= 0);
284 ubifs_assert(c, *pos < 8);
285 if (b) {
286 switch (bytes) {
287 case 2:
288 val = p[1];
289 break;
290 case 3:
291 val = p[1] | ((uint32_t)p[2] << 8);
292 break;
293 case 4:
294 val = p[1] | ((uint32_t)p[2] << 8) |
295 ((uint32_t)p[3] << 16);
296 break;
297 case 5:
298 val = p[1] | ((uint32_t)p[2] << 8) |
299 ((uint32_t)p[3] << 16) |
300 ((uint32_t)p[4] << 24);
301 }
302 val <<= (8 - b);
303 val |= *p >> b;
304 nrbits += b;
305 } else {
306 switch (bytes) {
307 case 1:
308 val = p[0];
309 break;
310 case 2:
311 val = p[0] | ((uint32_t)p[1] << 8);
312 break;
313 case 3:
314 val = p[0] | ((uint32_t)p[1] << 8) |
315 ((uint32_t)p[2] << 16);
316 break;
317 case 4:
318 val = p[0] | ((uint32_t)p[1] << 8) |
319 ((uint32_t)p[2] << 16) |
320 ((uint32_t)p[3] << 24);
321 break;
322 }
323 }
324 val <<= k;
325 val >>= k;
326 b = nrbits & 7;
327 p += nrbits >> 3;
328 *addr = p;
329 *pos = b;
330 ubifs_assert(c, (val >> nrbits) == 0 || nrbits - b == 32);
331 return val;
332 }
333
334 /**
335 * ubifs_pack_pnode - pack all the bit fields of a pnode.
336 * @c: UBIFS file-system description object
337 * @buf: buffer into which to pack
338 * @pnode: pnode to pack
339 */
ubifs_pack_pnode(struct ubifs_info * c,void * buf,struct ubifs_pnode * pnode)340 void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
341 struct ubifs_pnode *pnode)
342 {
343 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
344 int i, pos = 0;
345 uint16_t crc;
346
347 pack_bits(c, &addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
348 if (c->big_lpt)
349 pack_bits(c, &addr, &pos, pnode->num, c->pcnt_bits);
350 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
351 pack_bits(c, &addr, &pos, pnode->lprops[i].free >> 3,
352 c->space_bits);
353 pack_bits(c, &addr, &pos, pnode->lprops[i].dirty >> 3,
354 c->space_bits);
355 if (pnode->lprops[i].flags & LPROPS_INDEX)
356 pack_bits(c, &addr, &pos, 1, 1);
357 else
358 pack_bits(c, &addr, &pos, 0, 1);
359 }
360 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
361 c->pnode_sz - UBIFS_LPT_CRC_BYTES);
362 addr = buf;
363 pos = 0;
364 pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS);
365 }
366
367 /**
368 * ubifs_pack_nnode - pack all the bit fields of a nnode.
369 * @c: UBIFS file-system description object
370 * @buf: buffer into which to pack
371 * @nnode: nnode to pack
372 */
ubifs_pack_nnode(struct ubifs_info * c,void * buf,struct ubifs_nnode * nnode)373 void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
374 struct ubifs_nnode *nnode)
375 {
376 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
377 int i, pos = 0;
378 uint16_t crc;
379
380 pack_bits(c, &addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
381 if (c->big_lpt)
382 pack_bits(c, &addr, &pos, nnode->num, c->pcnt_bits);
383 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
384 int lnum = nnode->nbranch[i].lnum;
385
386 if (lnum == 0)
387 lnum = c->lpt_last + 1;
388 pack_bits(c, &addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
389 pack_bits(c, &addr, &pos, nnode->nbranch[i].offs,
390 c->lpt_offs_bits);
391 }
392 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
393 c->nnode_sz - UBIFS_LPT_CRC_BYTES);
394 addr = buf;
395 pos = 0;
396 pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS);
397 }
398
399 /**
400 * ubifs_pack_ltab - pack the LPT's own lprops table.
401 * @c: UBIFS file-system description object
402 * @buf: buffer into which to pack
403 * @ltab: LPT's own lprops table to pack
404 */
ubifs_pack_ltab(struct ubifs_info * c,void * buf,struct ubifs_lpt_lprops * ltab)405 void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
406 struct ubifs_lpt_lprops *ltab)
407 {
408 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
409 int i, pos = 0;
410 uint16_t crc;
411
412 pack_bits(c, &addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
413 for (i = 0; i < c->lpt_lebs; i++) {
414 pack_bits(c, &addr, &pos, ltab[i].free, c->lpt_spc_bits);
415 pack_bits(c, &addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
416 }
417 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
418 c->ltab_sz - UBIFS_LPT_CRC_BYTES);
419 addr = buf;
420 pos = 0;
421 pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS);
422 }
423
424 /**
425 * ubifs_pack_lsave - pack the LPT's save table.
426 * @c: UBIFS file-system description object
427 * @buf: buffer into which to pack
428 * @lsave: LPT's save table to pack
429 */
ubifs_pack_lsave(struct ubifs_info * c,void * buf,int * lsave)430 void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
431 {
432 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
433 int i, pos = 0;
434 uint16_t crc;
435
436 pack_bits(c, &addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
437 for (i = 0; i < c->lsave_cnt; i++)
438 pack_bits(c, &addr, &pos, lsave[i], c->lnum_bits);
439 crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
440 c->lsave_sz - UBIFS_LPT_CRC_BYTES);
441 addr = buf;
442 pos = 0;
443 pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS);
444 }
445
446 /**
447 * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
448 * @c: UBIFS file-system description object
449 * @lnum: LEB number to which to add dirty space
450 * @dirty: amount of dirty space to add
451 */
ubifs_add_lpt_dirt(struct ubifs_info * c,int lnum,int dirty)452 void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
453 {
454 if (!dirty || !lnum)
455 return;
456 dbg_lp("LEB %d add %d to %d",
457 lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
458 ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last);
459 c->ltab[lnum - c->lpt_first].dirty += dirty;
460 }
461
462 /**
463 * set_ltab - set LPT LEB properties.
464 * @c: UBIFS file-system description object
465 * @lnum: LEB number
466 * @free: amount of free space
467 * @dirty: amount of dirty space
468 */
set_ltab(struct ubifs_info * c,int lnum,int free,int dirty)469 static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
470 {
471 dbg_lp("LEB %d free %d dirty %d to %d %d",
472 lnum, c->ltab[lnum - c->lpt_first].free,
473 c->ltab[lnum - c->lpt_first].dirty, free, dirty);
474 ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last);
475 c->ltab[lnum - c->lpt_first].free = free;
476 c->ltab[lnum - c->lpt_first].dirty = dirty;
477 }
478
479 /**
480 * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
481 * @c: UBIFS file-system description object
482 * @nnode: nnode for which to add dirt
483 */
ubifs_add_nnode_dirt(struct ubifs_info * c,struct ubifs_nnode * nnode)484 void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
485 {
486 struct ubifs_nnode *np = nnode->parent;
487
488 if (np)
489 ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
490 c->nnode_sz);
491 else {
492 ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
493 if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
494 c->lpt_drty_flgs |= LTAB_DIRTY;
495 ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
496 }
497 }
498 }
499
500 /**
501 * add_pnode_dirt - add dirty space to LPT LEB properties.
502 * @c: UBIFS file-system description object
503 * @pnode: pnode for which to add dirt
504 */
add_pnode_dirt(struct ubifs_info * c,struct ubifs_pnode * pnode)505 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
506 {
507 ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
508 c->pnode_sz);
509 }
510
511 /**
512 * calc_nnode_num - calculate nnode number.
513 * @row: the row in the tree (root is zero)
514 * @col: the column in the row (leftmost is zero)
515 *
516 * The nnode number is a number that uniquely identifies a nnode and can be used
517 * easily to traverse the tree from the root to that nnode.
518 *
519 * This function calculates and returns the nnode number for the nnode at @row
520 * and @col.
521 */
calc_nnode_num(int row,int col)522 static int calc_nnode_num(int row, int col)
523 {
524 int num, bits;
525
526 num = 1;
527 while (row--) {
528 bits = (col & (UBIFS_LPT_FANOUT - 1));
529 col >>= UBIFS_LPT_FANOUT_SHIFT;
530 num <<= UBIFS_LPT_FANOUT_SHIFT;
531 num |= bits;
532 }
533 return num;
534 }
535
536 /**
537 * calc_nnode_num_from_parent - calculate nnode number.
538 * @c: UBIFS file-system description object
539 * @parent: parent nnode
540 * @iip: index in parent
541 *
542 * The nnode number is a number that uniquely identifies a nnode and can be used
543 * easily to traverse the tree from the root to that nnode.
544 *
545 * This function calculates and returns the nnode number based on the parent's
546 * nnode number and the index in parent.
547 */
calc_nnode_num_from_parent(const struct ubifs_info * c,struct ubifs_nnode * parent,int iip)548 static int calc_nnode_num_from_parent(const struct ubifs_info *c,
549 struct ubifs_nnode *parent, int iip)
550 {
551 int num, shft;
552
553 if (!parent)
554 return 1;
555 shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
556 num = parent->num ^ (1 << shft);
557 num |= (UBIFS_LPT_FANOUT + iip) << shft;
558 return num;
559 }
560
561 /**
562 * calc_pnode_num_from_parent - calculate pnode number.
563 * @c: UBIFS file-system description object
564 * @parent: parent nnode
565 * @iip: index in parent
566 *
567 * The pnode number is a number that uniquely identifies a pnode and can be used
568 * easily to traverse the tree from the root to that pnode.
569 *
570 * This function calculates and returns the pnode number based on the parent's
571 * nnode number and the index in parent.
572 */
calc_pnode_num_from_parent(const struct ubifs_info * c,struct ubifs_nnode * parent,int iip)573 static int calc_pnode_num_from_parent(const struct ubifs_info *c,
574 struct ubifs_nnode *parent, int iip)
575 {
576 int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
577
578 for (i = 0; i < n; i++) {
579 num <<= UBIFS_LPT_FANOUT_SHIFT;
580 num |= pnum & (UBIFS_LPT_FANOUT - 1);
581 pnum >>= UBIFS_LPT_FANOUT_SHIFT;
582 }
583 num <<= UBIFS_LPT_FANOUT_SHIFT;
584 num |= iip;
585 return num;
586 }
587
588 /**
589 * ubifs_create_dflt_lpt - create default LPT.
590 * @c: UBIFS file-system description object
591 * @main_lebs: number of main area LEBs is passed and returned here
592 * @lpt_first: LEB number of first LPT LEB
593 * @lpt_lebs: number of LEBs for LPT is passed and returned here
594 * @big_lpt: use big LPT model is passed and returned here
595 * @hash: hash of the LPT is returned here
596 *
597 * This function returns %0 on success and a negative error code on failure.
598 */
ubifs_create_dflt_lpt(struct ubifs_info * c,int * main_lebs,int lpt_first,int * lpt_lebs,int * big_lpt,u8 * hash)599 int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
600 int *lpt_lebs, int *big_lpt, u8 *hash)
601 {
602 int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
603 int blnum, boffs, bsz, bcnt;
604 struct ubifs_pnode *pnode = NULL;
605 struct ubifs_nnode *nnode = NULL;
606 void *buf = NULL, *p;
607 struct ubifs_lpt_lprops *ltab = NULL;
608 int *lsave = NULL;
609 struct shash_desc *desc;
610
611 err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
612 if (err)
613 return err;
614 *lpt_lebs = c->lpt_lebs;
615
616 /* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
617 c->lpt_first = lpt_first;
618 /* Needed by 'set_ltab()' */
619 c->lpt_last = lpt_first + c->lpt_lebs - 1;
620 /* Needed by 'ubifs_pack_lsave()' */
621 c->main_first = c->leb_cnt - *main_lebs;
622
623 desc = ubifs_hash_get_desc(c);
624 if (IS_ERR(desc))
625 return PTR_ERR(desc);
626
627 lsave = kmalloc_array(c->lsave_cnt, sizeof(int), GFP_KERNEL);
628 pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
629 nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
630 buf = vmalloc(c->leb_size);
631 ltab = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops),
632 c->lpt_lebs));
633 if (!pnode || !nnode || !buf || !ltab || !lsave) {
634 err = -ENOMEM;
635 goto out;
636 }
637
638 ubifs_assert(c, !c->ltab);
639 c->ltab = ltab; /* Needed by set_ltab */
640
641 /* Initialize LPT's own lprops */
642 for (i = 0; i < c->lpt_lebs; i++) {
643 ltab[i].free = c->leb_size;
644 ltab[i].dirty = 0;
645 ltab[i].tgc = 0;
646 ltab[i].cmt = 0;
647 }
648
649 lnum = lpt_first;
650 p = buf;
651 /* Number of leaf nodes (pnodes) */
652 cnt = c->pnode_cnt;
653
654 /*
655 * The first pnode contains the LEB properties for the LEBs that contain
656 * the root inode node and the root index node of the index tree.
657 */
658 node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
659 iopos = ALIGN(node_sz, c->min_io_size);
660 pnode->lprops[0].free = c->leb_size - iopos;
661 pnode->lprops[0].dirty = iopos - node_sz;
662 pnode->lprops[0].flags = LPROPS_INDEX;
663
664 node_sz = UBIFS_INO_NODE_SZ;
665 iopos = ALIGN(node_sz, c->min_io_size);
666 pnode->lprops[1].free = c->leb_size - iopos;
667 pnode->lprops[1].dirty = iopos - node_sz;
668
669 for (i = 2; i < UBIFS_LPT_FANOUT; i++)
670 pnode->lprops[i].free = c->leb_size;
671
672 /* Add first pnode */
673 ubifs_pack_pnode(c, p, pnode);
674 err = ubifs_shash_update(c, desc, p, c->pnode_sz);
675 if (err)
676 goto out;
677
678 p += c->pnode_sz;
679 len = c->pnode_sz;
680 pnode->num += 1;
681
682 /* Reset pnode values for remaining pnodes */
683 pnode->lprops[0].free = c->leb_size;
684 pnode->lprops[0].dirty = 0;
685 pnode->lprops[0].flags = 0;
686
687 pnode->lprops[1].free = c->leb_size;
688 pnode->lprops[1].dirty = 0;
689
690 /*
691 * To calculate the internal node branches, we keep information about
692 * the level below.
693 */
694 blnum = lnum; /* LEB number of level below */
695 boffs = 0; /* Offset of level below */
696 bcnt = cnt; /* Number of nodes in level below */
697 bsz = c->pnode_sz; /* Size of nodes in level below */
698
699 /* Add all remaining pnodes */
700 for (i = 1; i < cnt; i++) {
701 if (len + c->pnode_sz > c->leb_size) {
702 alen = ALIGN(len, c->min_io_size);
703 set_ltab(c, lnum, c->leb_size - alen, alen - len);
704 memset(p, 0xff, alen - len);
705 err = ubifs_leb_change(c, lnum++, buf, alen);
706 if (err)
707 goto out;
708 p = buf;
709 len = 0;
710 }
711 ubifs_pack_pnode(c, p, pnode);
712 err = ubifs_shash_update(c, desc, p, c->pnode_sz);
713 if (err)
714 goto out;
715
716 p += c->pnode_sz;
717 len += c->pnode_sz;
718 /*
719 * pnodes are simply numbered left to right starting at zero,
720 * which means the pnode number can be used easily to traverse
721 * down the tree to the corresponding pnode.
722 */
723 pnode->num += 1;
724 }
725
726 row = 0;
727 for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
728 row += 1;
729 /* Add all nnodes, one level at a time */
730 while (1) {
731 /* Number of internal nodes (nnodes) at next level */
732 cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
733 for (i = 0; i < cnt; i++) {
734 if (len + c->nnode_sz > c->leb_size) {
735 alen = ALIGN(len, c->min_io_size);
736 set_ltab(c, lnum, c->leb_size - alen,
737 alen - len);
738 memset(p, 0xff, alen - len);
739 err = ubifs_leb_change(c, lnum++, buf, alen);
740 if (err)
741 goto out;
742 p = buf;
743 len = 0;
744 }
745 /* Only 1 nnode at this level, so it is the root */
746 if (cnt == 1) {
747 c->lpt_lnum = lnum;
748 c->lpt_offs = len;
749 }
750 /* Set branches to the level below */
751 for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
752 if (bcnt) {
753 if (boffs + bsz > c->leb_size) {
754 blnum += 1;
755 boffs = 0;
756 }
757 nnode->nbranch[j].lnum = blnum;
758 nnode->nbranch[j].offs = boffs;
759 boffs += bsz;
760 bcnt--;
761 } else {
762 nnode->nbranch[j].lnum = 0;
763 nnode->nbranch[j].offs = 0;
764 }
765 }
766 nnode->num = calc_nnode_num(row, i);
767 ubifs_pack_nnode(c, p, nnode);
768 p += c->nnode_sz;
769 len += c->nnode_sz;
770 }
771 /* Only 1 nnode at this level, so it is the root */
772 if (cnt == 1)
773 break;
774 /* Update the information about the level below */
775 bcnt = cnt;
776 bsz = c->nnode_sz;
777 row -= 1;
778 }
779
780 if (*big_lpt) {
781 /* Need to add LPT's save table */
782 if (len + c->lsave_sz > c->leb_size) {
783 alen = ALIGN(len, c->min_io_size);
784 set_ltab(c, lnum, c->leb_size - alen, alen - len);
785 memset(p, 0xff, alen - len);
786 err = ubifs_leb_change(c, lnum++, buf, alen);
787 if (err)
788 goto out;
789 p = buf;
790 len = 0;
791 }
792
793 c->lsave_lnum = lnum;
794 c->lsave_offs = len;
795
796 for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
797 lsave[i] = c->main_first + i;
798 for (; i < c->lsave_cnt; i++)
799 lsave[i] = c->main_first;
800
801 ubifs_pack_lsave(c, p, lsave);
802 p += c->lsave_sz;
803 len += c->lsave_sz;
804 }
805
806 /* Need to add LPT's own LEB properties table */
807 if (len + c->ltab_sz > c->leb_size) {
808 alen = ALIGN(len, c->min_io_size);
809 set_ltab(c, lnum, c->leb_size - alen, alen - len);
810 memset(p, 0xff, alen - len);
811 err = ubifs_leb_change(c, lnum++, buf, alen);
812 if (err)
813 goto out;
814 p = buf;
815 len = 0;
816 }
817
818 c->ltab_lnum = lnum;
819 c->ltab_offs = len;
820
821 /* Update ltab before packing it */
822 len += c->ltab_sz;
823 alen = ALIGN(len, c->min_io_size);
824 set_ltab(c, lnum, c->leb_size - alen, alen - len);
825
826 ubifs_pack_ltab(c, p, ltab);
827 p += c->ltab_sz;
828
829 /* Write remaining buffer */
830 memset(p, 0xff, alen - len);
831 err = ubifs_leb_change(c, lnum, buf, alen);
832 if (err)
833 goto out;
834
835 err = ubifs_shash_final(c, desc, hash);
836 if (err)
837 goto out;
838
839 c->nhead_lnum = lnum;
840 c->nhead_offs = ALIGN(len, c->min_io_size);
841
842 dbg_lp("space_bits %d", c->space_bits);
843 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
844 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
845 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
846 dbg_lp("pcnt_bits %d", c->pcnt_bits);
847 dbg_lp("lnum_bits %d", c->lnum_bits);
848 dbg_lp("pnode_sz %d", c->pnode_sz);
849 dbg_lp("nnode_sz %d", c->nnode_sz);
850 dbg_lp("ltab_sz %d", c->ltab_sz);
851 dbg_lp("lsave_sz %d", c->lsave_sz);
852 dbg_lp("lsave_cnt %d", c->lsave_cnt);
853 dbg_lp("lpt_hght %d", c->lpt_hght);
854 dbg_lp("big_lpt %u", c->big_lpt);
855 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
856 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
857 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
858 if (c->big_lpt)
859 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
860 out:
861 c->ltab = NULL;
862 kfree(desc);
863 kfree(lsave);
864 vfree(ltab);
865 vfree(buf);
866 kfree(nnode);
867 kfree(pnode);
868 return err;
869 }
870
871 /**
872 * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
873 * @c: UBIFS file-system description object
874 * @pnode: pnode
875 *
876 * When a pnode is loaded into memory, the LEB properties it contains are added,
877 * by this function, to the LEB category lists and heaps.
878 */
update_cats(struct ubifs_info * c,struct ubifs_pnode * pnode)879 static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
880 {
881 int i;
882
883 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
884 int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
885 int lnum = pnode->lprops[i].lnum;
886
887 if (!lnum)
888 return;
889 ubifs_add_to_cat(c, &pnode->lprops[i], cat);
890 }
891 }
892
893 /**
894 * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
895 * @c: UBIFS file-system description object
896 * @old_pnode: pnode copied
897 * @new_pnode: pnode copy
898 *
899 * During commit it is sometimes necessary to copy a pnode
900 * (see dirty_cow_pnode). When that happens, references in
901 * category lists and heaps must be replaced. This function does that.
902 */
replace_cats(struct ubifs_info * c,struct ubifs_pnode * old_pnode,struct ubifs_pnode * new_pnode)903 static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
904 struct ubifs_pnode *new_pnode)
905 {
906 int i;
907
908 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
909 if (!new_pnode->lprops[i].lnum)
910 return;
911 ubifs_replace_cat(c, &old_pnode->lprops[i],
912 &new_pnode->lprops[i]);
913 }
914 }
915
916 /**
917 * check_lpt_crc - check LPT node crc is correct.
918 * @c: UBIFS file-system description object
919 * @buf: buffer containing node
920 * @len: length of node
921 *
922 * This function returns %0 on success and a negative error code on failure.
923 */
check_lpt_crc(const struct ubifs_info * c,void * buf,int len)924 static int check_lpt_crc(const struct ubifs_info *c, void *buf, int len)
925 {
926 int pos = 0;
927 uint8_t *addr = buf;
928 uint16_t crc, calc_crc;
929
930 crc = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_CRC_BITS);
931 calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
932 len - UBIFS_LPT_CRC_BYTES);
933 if (crc != calc_crc) {
934 ubifs_err(c, "invalid crc in LPT node: crc %hx calc %hx",
935 crc, calc_crc);
936 dump_stack();
937 return -EINVAL;
938 }
939 return 0;
940 }
941
942 /**
943 * check_lpt_type - check LPT node type is correct.
944 * @c: UBIFS file-system description object
945 * @addr: address of type bit field is passed and returned updated here
946 * @pos: position of type bit field is passed and returned updated here
947 * @type: expected type
948 *
949 * This function returns %0 on success and a negative error code on failure.
950 */
check_lpt_type(const struct ubifs_info * c,uint8_t ** addr,int * pos,int type)951 static int check_lpt_type(const struct ubifs_info *c, uint8_t **addr,
952 int *pos, int type)
953 {
954 int node_type;
955
956 node_type = ubifs_unpack_bits(c, addr, pos, UBIFS_LPT_TYPE_BITS);
957 if (node_type != type) {
958 ubifs_err(c, "invalid type (%d) in LPT node type %d",
959 node_type, type);
960 dump_stack();
961 return -EINVAL;
962 }
963 return 0;
964 }
965
966 /**
967 * unpack_pnode - unpack a pnode.
968 * @c: UBIFS file-system description object
969 * @buf: buffer containing packed pnode to unpack
970 * @pnode: pnode structure to fill
971 *
972 * This function returns %0 on success and a negative error code on failure.
973 */
unpack_pnode(const struct ubifs_info * c,void * buf,struct ubifs_pnode * pnode)974 static int unpack_pnode(const struct ubifs_info *c, void *buf,
975 struct ubifs_pnode *pnode)
976 {
977 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
978 int i, pos = 0, err;
979
980 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_PNODE);
981 if (err)
982 return err;
983 if (c->big_lpt)
984 pnode->num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits);
985 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
986 struct ubifs_lprops * const lprops = &pnode->lprops[i];
987
988 lprops->free = ubifs_unpack_bits(c, &addr, &pos, c->space_bits);
989 lprops->free <<= 3;
990 lprops->dirty = ubifs_unpack_bits(c, &addr, &pos, c->space_bits);
991 lprops->dirty <<= 3;
992
993 if (ubifs_unpack_bits(c, &addr, &pos, 1))
994 lprops->flags = LPROPS_INDEX;
995 else
996 lprops->flags = 0;
997 lprops->flags |= ubifs_categorize_lprops(c, lprops);
998 }
999 err = check_lpt_crc(c, buf, c->pnode_sz);
1000 return err;
1001 }
1002
1003 /**
1004 * ubifs_unpack_nnode - unpack a nnode.
1005 * @c: UBIFS file-system description object
1006 * @buf: buffer containing packed nnode to unpack
1007 * @nnode: nnode structure to fill
1008 *
1009 * This function returns %0 on success and a negative error code on failure.
1010 */
ubifs_unpack_nnode(const struct ubifs_info * c,void * buf,struct ubifs_nnode * nnode)1011 int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
1012 struct ubifs_nnode *nnode)
1013 {
1014 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1015 int i, pos = 0, err;
1016
1017 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_NNODE);
1018 if (err)
1019 return err;
1020 if (c->big_lpt)
1021 nnode->num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits);
1022 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1023 int lnum;
1024
1025 lnum = ubifs_unpack_bits(c, &addr, &pos, c->lpt_lnum_bits) +
1026 c->lpt_first;
1027 if (lnum == c->lpt_last + 1)
1028 lnum = 0;
1029 nnode->nbranch[i].lnum = lnum;
1030 nnode->nbranch[i].offs = ubifs_unpack_bits(c, &addr, &pos,
1031 c->lpt_offs_bits);
1032 }
1033 err = check_lpt_crc(c, buf, c->nnode_sz);
1034 return err;
1035 }
1036
1037 /**
1038 * unpack_ltab - unpack the LPT's own lprops table.
1039 * @c: UBIFS file-system description object
1040 * @buf: buffer from which to unpack
1041 *
1042 * This function returns %0 on success and a negative error code on failure.
1043 */
unpack_ltab(const struct ubifs_info * c,void * buf)1044 static int unpack_ltab(const struct ubifs_info *c, void *buf)
1045 {
1046 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1047 int i, pos = 0, err;
1048
1049 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LTAB);
1050 if (err)
1051 return err;
1052 for (i = 0; i < c->lpt_lebs; i++) {
1053 int free = ubifs_unpack_bits(c, &addr, &pos, c->lpt_spc_bits);
1054 int dirty = ubifs_unpack_bits(c, &addr, &pos, c->lpt_spc_bits);
1055
1056 if (free < 0 || free > c->leb_size || dirty < 0 ||
1057 dirty > c->leb_size || free + dirty > c->leb_size)
1058 return -EINVAL;
1059
1060 c->ltab[i].free = free;
1061 c->ltab[i].dirty = dirty;
1062 c->ltab[i].tgc = 0;
1063 c->ltab[i].cmt = 0;
1064 }
1065 err = check_lpt_crc(c, buf, c->ltab_sz);
1066 return err;
1067 }
1068
1069 /**
1070 * unpack_lsave - unpack the LPT's save table.
1071 * @c: UBIFS file-system description object
1072 * @buf: buffer from which to unpack
1073 *
1074 * This function returns %0 on success and a negative error code on failure.
1075 */
unpack_lsave(const struct ubifs_info * c,void * buf)1076 static int unpack_lsave(const struct ubifs_info *c, void *buf)
1077 {
1078 uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1079 int i, pos = 0, err;
1080
1081 err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LSAVE);
1082 if (err)
1083 return err;
1084 for (i = 0; i < c->lsave_cnt; i++) {
1085 int lnum = ubifs_unpack_bits(c, &addr, &pos, c->lnum_bits);
1086
1087 if (lnum < c->main_first || lnum >= c->leb_cnt)
1088 return -EINVAL;
1089 c->lsave[i] = lnum;
1090 }
1091 err = check_lpt_crc(c, buf, c->lsave_sz);
1092 return err;
1093 }
1094
1095 /**
1096 * validate_nnode - validate a nnode.
1097 * @c: UBIFS file-system description object
1098 * @nnode: nnode to validate
1099 * @parent: parent nnode (or NULL for the root nnode)
1100 * @iip: index in parent
1101 *
1102 * This function returns %0 on success and a negative error code on failure.
1103 */
validate_nnode(const struct ubifs_info * c,struct ubifs_nnode * nnode,struct ubifs_nnode * parent,int iip)1104 static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
1105 struct ubifs_nnode *parent, int iip)
1106 {
1107 int i, lvl, max_offs;
1108
1109 if (c->big_lpt) {
1110 int num = calc_nnode_num_from_parent(c, parent, iip);
1111
1112 if (nnode->num != num)
1113 return -EINVAL;
1114 }
1115 lvl = parent ? parent->level - 1 : c->lpt_hght;
1116 if (lvl < 1)
1117 return -EINVAL;
1118 if (lvl == 1)
1119 max_offs = c->leb_size - c->pnode_sz;
1120 else
1121 max_offs = c->leb_size - c->nnode_sz;
1122 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1123 int lnum = nnode->nbranch[i].lnum;
1124 int offs = nnode->nbranch[i].offs;
1125
1126 if (lnum == 0) {
1127 if (offs != 0)
1128 return -EINVAL;
1129 continue;
1130 }
1131 if (lnum < c->lpt_first || lnum > c->lpt_last)
1132 return -EINVAL;
1133 if (offs < 0 || offs > max_offs)
1134 return -EINVAL;
1135 }
1136 return 0;
1137 }
1138
1139 /**
1140 * validate_pnode - validate a pnode.
1141 * @c: UBIFS file-system description object
1142 * @pnode: pnode to validate
1143 * @parent: parent nnode
1144 * @iip: index in parent
1145 *
1146 * This function returns %0 on success and a negative error code on failure.
1147 */
validate_pnode(const struct ubifs_info * c,struct ubifs_pnode * pnode,struct ubifs_nnode * parent,int iip)1148 static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
1149 struct ubifs_nnode *parent, int iip)
1150 {
1151 int i;
1152
1153 if (c->big_lpt) {
1154 int num = calc_pnode_num_from_parent(c, parent, iip);
1155
1156 if (pnode->num != num)
1157 return -EINVAL;
1158 }
1159 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1160 int free = pnode->lprops[i].free;
1161 int dirty = pnode->lprops[i].dirty;
1162
1163 if (free < 0 || free > c->leb_size || free % c->min_io_size ||
1164 (free & 7))
1165 return -EINVAL;
1166 if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
1167 return -EINVAL;
1168 if (dirty + free > c->leb_size)
1169 return -EINVAL;
1170 }
1171 return 0;
1172 }
1173
1174 /**
1175 * set_pnode_lnum - set LEB numbers on a pnode.
1176 * @c: UBIFS file-system description object
1177 * @pnode: pnode to update
1178 *
1179 * This function calculates the LEB numbers for the LEB properties it contains
1180 * based on the pnode number.
1181 */
set_pnode_lnum(const struct ubifs_info * c,struct ubifs_pnode * pnode)1182 static void set_pnode_lnum(const struct ubifs_info *c,
1183 struct ubifs_pnode *pnode)
1184 {
1185 int i, lnum;
1186
1187 lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
1188 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1189 if (lnum >= c->leb_cnt)
1190 return;
1191 pnode->lprops[i].lnum = lnum++;
1192 }
1193 }
1194
1195 /**
1196 * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
1197 * @c: UBIFS file-system description object
1198 * @parent: parent nnode (or NULL for the root)
1199 * @iip: index in parent
1200 *
1201 * This function returns %0 on success and a negative error code on failure.
1202 */
ubifs_read_nnode(struct ubifs_info * c,struct ubifs_nnode * parent,int iip)1203 int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1204 {
1205 struct ubifs_nbranch *branch = NULL;
1206 struct ubifs_nnode *nnode = NULL;
1207 void *buf = c->lpt_nod_buf;
1208 int err, lnum, offs;
1209
1210 if (parent) {
1211 branch = &parent->nbranch[iip];
1212 lnum = branch->lnum;
1213 offs = branch->offs;
1214 } else {
1215 lnum = c->lpt_lnum;
1216 offs = c->lpt_offs;
1217 }
1218 nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
1219 if (!nnode) {
1220 err = -ENOMEM;
1221 goto out;
1222 }
1223 if (lnum == 0) {
1224 /*
1225 * This nnode was not written which just means that the LEB
1226 * properties in the subtree below it describe empty LEBs. We
1227 * make the nnode as though we had read it, which in fact means
1228 * doing almost nothing.
1229 */
1230 if (c->big_lpt)
1231 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1232 } else {
1233 err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1);
1234 if (err)
1235 goto out;
1236 err = ubifs_unpack_nnode(c, buf, nnode);
1237 if (err)
1238 goto out;
1239 }
1240 err = validate_nnode(c, nnode, parent, iip);
1241 if (err)
1242 goto out;
1243 if (!c->big_lpt)
1244 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1245 if (parent) {
1246 branch->nnode = nnode;
1247 nnode->level = parent->level - 1;
1248 } else {
1249 c->nroot = nnode;
1250 nnode->level = c->lpt_hght;
1251 }
1252 nnode->parent = parent;
1253 nnode->iip = iip;
1254 return 0;
1255
1256 out:
1257 ubifs_err(c, "error %d reading nnode at %d:%d", err, lnum, offs);
1258 dump_stack();
1259 kfree(nnode);
1260 return err;
1261 }
1262
1263 /**
1264 * read_pnode - read a pnode from flash and link it to the tree in memory.
1265 * @c: UBIFS file-system description object
1266 * @parent: parent nnode
1267 * @iip: index in parent
1268 *
1269 * This function returns %0 on success and a negative error code on failure.
1270 */
read_pnode(struct ubifs_info * c,struct ubifs_nnode * parent,int iip)1271 static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
1272 {
1273 struct ubifs_nbranch *branch;
1274 struct ubifs_pnode *pnode = NULL;
1275 void *buf = c->lpt_nod_buf;
1276 int err, lnum, offs;
1277
1278 branch = &parent->nbranch[iip];
1279 lnum = branch->lnum;
1280 offs = branch->offs;
1281 pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
1282 if (!pnode)
1283 return -ENOMEM;
1284
1285 if (lnum == 0) {
1286 /*
1287 * This pnode was not written which just means that the LEB
1288 * properties in it describe empty LEBs. We make the pnode as
1289 * though we had read it.
1290 */
1291 int i;
1292
1293 if (c->big_lpt)
1294 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1295 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1296 struct ubifs_lprops * const lprops = &pnode->lprops[i];
1297
1298 lprops->free = c->leb_size;
1299 lprops->flags = ubifs_categorize_lprops(c, lprops);
1300 }
1301 } else {
1302 err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1);
1303 if (err)
1304 goto out;
1305 err = unpack_pnode(c, buf, pnode);
1306 if (err)
1307 goto out;
1308 }
1309 err = validate_pnode(c, pnode, parent, iip);
1310 if (err)
1311 goto out;
1312 if (!c->big_lpt)
1313 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
1314 branch->pnode = pnode;
1315 pnode->parent = parent;
1316 pnode->iip = iip;
1317 set_pnode_lnum(c, pnode);
1318 c->pnodes_have += 1;
1319 return 0;
1320
1321 out:
1322 ubifs_err(c, "error %d reading pnode at %d:%d", err, lnum, offs);
1323 ubifs_dump_pnode(c, pnode, parent, iip);
1324 dump_stack();
1325 ubifs_err(c, "calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
1326 kfree(pnode);
1327 return err;
1328 }
1329
1330 /**
1331 * read_ltab - read LPT's own lprops table.
1332 * @c: UBIFS file-system description object
1333 *
1334 * This function returns %0 on success and a negative error code on failure.
1335 */
read_ltab(struct ubifs_info * c)1336 static int read_ltab(struct ubifs_info *c)
1337 {
1338 int err;
1339 void *buf;
1340
1341 buf = vmalloc(c->ltab_sz);
1342 if (!buf)
1343 return -ENOMEM;
1344 err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1);
1345 if (err)
1346 goto out;
1347 err = unpack_ltab(c, buf);
1348 out:
1349 vfree(buf);
1350 return err;
1351 }
1352
1353 /**
1354 * read_lsave - read LPT's save table.
1355 * @c: UBIFS file-system description object
1356 *
1357 * This function returns %0 on success and a negative error code on failure.
1358 */
read_lsave(struct ubifs_info * c)1359 static int read_lsave(struct ubifs_info *c)
1360 {
1361 int err, i;
1362 void *buf;
1363
1364 buf = vmalloc(c->lsave_sz);
1365 if (!buf)
1366 return -ENOMEM;
1367 err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs,
1368 c->lsave_sz, 1);
1369 if (err)
1370 goto out;
1371 err = unpack_lsave(c, buf);
1372 if (err)
1373 goto out;
1374 for (i = 0; i < c->lsave_cnt; i++) {
1375 int lnum = c->lsave[i];
1376 struct ubifs_lprops *lprops;
1377
1378 /*
1379 * Due to automatic resizing, the values in the lsave table
1380 * could be beyond the volume size - just ignore them.
1381 */
1382 if (lnum >= c->leb_cnt)
1383 continue;
1384 lprops = ubifs_lpt_lookup(c, lnum);
1385 if (IS_ERR(lprops)) {
1386 err = PTR_ERR(lprops);
1387 goto out;
1388 }
1389 }
1390 out:
1391 vfree(buf);
1392 return err;
1393 }
1394
1395 /**
1396 * ubifs_get_nnode - get a nnode.
1397 * @c: UBIFS file-system description object
1398 * @parent: parent nnode (or NULL for the root)
1399 * @iip: index in parent
1400 *
1401 * This function returns a pointer to the nnode on success or a negative error
1402 * code on failure.
1403 */
ubifs_get_nnode(struct ubifs_info * c,struct ubifs_nnode * parent,int iip)1404 struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
1405 struct ubifs_nnode *parent, int iip)
1406 {
1407 struct ubifs_nbranch *branch;
1408 struct ubifs_nnode *nnode;
1409 int err;
1410
1411 branch = &parent->nbranch[iip];
1412 nnode = branch->nnode;
1413 if (nnode)
1414 return nnode;
1415 err = ubifs_read_nnode(c, parent, iip);
1416 if (err)
1417 return ERR_PTR(err);
1418 return branch->nnode;
1419 }
1420
1421 /**
1422 * ubifs_get_pnode - get a pnode.
1423 * @c: UBIFS file-system description object
1424 * @parent: parent nnode
1425 * @iip: index in parent
1426 *
1427 * This function returns a pointer to the pnode on success or a negative error
1428 * code on failure.
1429 */
ubifs_get_pnode(struct ubifs_info * c,struct ubifs_nnode * parent,int iip)1430 struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
1431 struct ubifs_nnode *parent, int iip)
1432 {
1433 struct ubifs_nbranch *branch;
1434 struct ubifs_pnode *pnode;
1435 int err;
1436
1437 branch = &parent->nbranch[iip];
1438 pnode = branch->pnode;
1439 if (pnode)
1440 return pnode;
1441 err = read_pnode(c, parent, iip);
1442 if (err)
1443 return ERR_PTR(err);
1444 update_cats(c, branch->pnode);
1445 return branch->pnode;
1446 }
1447
1448 /**
1449 * ubifs_pnode_lookup - lookup a pnode in the LPT.
1450 * @c: UBIFS file-system description object
1451 * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT)
1452 *
1453 * This function returns a pointer to the pnode on success or a negative
1454 * error code on failure.
1455 */
ubifs_pnode_lookup(struct ubifs_info * c,int i)1456 struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i)
1457 {
1458 int err, h, iip, shft;
1459 struct ubifs_nnode *nnode;
1460
1461 if (!c->nroot) {
1462 err = ubifs_read_nnode(c, NULL, 0);
1463 if (err)
1464 return ERR_PTR(err);
1465 }
1466 i <<= UBIFS_LPT_FANOUT_SHIFT;
1467 nnode = c->nroot;
1468 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1469 for (h = 1; h < c->lpt_hght; h++) {
1470 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1471 shft -= UBIFS_LPT_FANOUT_SHIFT;
1472 nnode = ubifs_get_nnode(c, nnode, iip);
1473 if (IS_ERR(nnode))
1474 return ERR_CAST(nnode);
1475 }
1476 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1477 return ubifs_get_pnode(c, nnode, iip);
1478 }
1479
1480 /**
1481 * ubifs_lpt_lookup - lookup LEB properties in the LPT.
1482 * @c: UBIFS file-system description object
1483 * @lnum: LEB number to lookup
1484 *
1485 * This function returns a pointer to the LEB properties on success or a
1486 * negative error code on failure.
1487 */
ubifs_lpt_lookup(struct ubifs_info * c,int lnum)1488 struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
1489 {
1490 int i, iip;
1491 struct ubifs_pnode *pnode;
1492
1493 i = lnum - c->main_first;
1494 pnode = ubifs_pnode_lookup(c, i >> UBIFS_LPT_FANOUT_SHIFT);
1495 if (IS_ERR(pnode))
1496 return ERR_CAST(pnode);
1497 iip = (i & (UBIFS_LPT_FANOUT - 1));
1498 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1499 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1500 pnode->lprops[iip].flags);
1501 return &pnode->lprops[iip];
1502 }
1503
1504 /**
1505 * dirty_cow_nnode - ensure a nnode is not being committed.
1506 * @c: UBIFS file-system description object
1507 * @nnode: nnode to check
1508 *
1509 * Returns dirtied nnode on success or negative error code on failure.
1510 */
dirty_cow_nnode(struct ubifs_info * c,struct ubifs_nnode * nnode)1511 static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
1512 struct ubifs_nnode *nnode)
1513 {
1514 struct ubifs_nnode *n;
1515 int i;
1516
1517 if (!test_bit(COW_CNODE, &nnode->flags)) {
1518 /* nnode is not being committed */
1519 if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
1520 c->dirty_nn_cnt += 1;
1521 ubifs_add_nnode_dirt(c, nnode);
1522 }
1523 return nnode;
1524 }
1525
1526 /* nnode is being committed, so copy it */
1527 n = kmemdup(nnode, sizeof(struct ubifs_nnode), GFP_NOFS);
1528 if (unlikely(!n))
1529 return ERR_PTR(-ENOMEM);
1530
1531 n->cnext = NULL;
1532 __set_bit(DIRTY_CNODE, &n->flags);
1533 __clear_bit(COW_CNODE, &n->flags);
1534
1535 /* The children now have new parent */
1536 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1537 struct ubifs_nbranch *branch = &n->nbranch[i];
1538
1539 if (branch->cnode)
1540 branch->cnode->parent = n;
1541 }
1542
1543 ubifs_assert(c, !test_bit(OBSOLETE_CNODE, &nnode->flags));
1544 __set_bit(OBSOLETE_CNODE, &nnode->flags);
1545
1546 c->dirty_nn_cnt += 1;
1547 ubifs_add_nnode_dirt(c, nnode);
1548 if (nnode->parent)
1549 nnode->parent->nbranch[n->iip].nnode = n;
1550 else
1551 c->nroot = n;
1552 return n;
1553 }
1554
1555 /**
1556 * dirty_cow_pnode - ensure a pnode is not being committed.
1557 * @c: UBIFS file-system description object
1558 * @pnode: pnode to check
1559 *
1560 * Returns dirtied pnode on success or negative error code on failure.
1561 */
dirty_cow_pnode(struct ubifs_info * c,struct ubifs_pnode * pnode)1562 static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
1563 struct ubifs_pnode *pnode)
1564 {
1565 struct ubifs_pnode *p;
1566
1567 if (!test_bit(COW_CNODE, &pnode->flags)) {
1568 /* pnode is not being committed */
1569 if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
1570 c->dirty_pn_cnt += 1;
1571 add_pnode_dirt(c, pnode);
1572 }
1573 return pnode;
1574 }
1575
1576 /* pnode is being committed, so copy it */
1577 p = kmemdup(pnode, sizeof(struct ubifs_pnode), GFP_NOFS);
1578 if (unlikely(!p))
1579 return ERR_PTR(-ENOMEM);
1580
1581 p->cnext = NULL;
1582 __set_bit(DIRTY_CNODE, &p->flags);
1583 __clear_bit(COW_CNODE, &p->flags);
1584 replace_cats(c, pnode, p);
1585
1586 ubifs_assert(c, !test_bit(OBSOLETE_CNODE, &pnode->flags));
1587 __set_bit(OBSOLETE_CNODE, &pnode->flags);
1588
1589 c->dirty_pn_cnt += 1;
1590 add_pnode_dirt(c, pnode);
1591 pnode->parent->nbranch[p->iip].pnode = p;
1592 return p;
1593 }
1594
1595 /**
1596 * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
1597 * @c: UBIFS file-system description object
1598 * @lnum: LEB number to lookup
1599 *
1600 * This function returns a pointer to the LEB properties on success or a
1601 * negative error code on failure.
1602 */
ubifs_lpt_lookup_dirty(struct ubifs_info * c,int lnum)1603 struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
1604 {
1605 int err, i, h, iip, shft;
1606 struct ubifs_nnode *nnode;
1607 struct ubifs_pnode *pnode;
1608
1609 if (!c->nroot) {
1610 err = ubifs_read_nnode(c, NULL, 0);
1611 if (err)
1612 return ERR_PTR(err);
1613 }
1614 nnode = c->nroot;
1615 nnode = dirty_cow_nnode(c, nnode);
1616 if (IS_ERR(nnode))
1617 return ERR_CAST(nnode);
1618 i = lnum - c->main_first;
1619 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
1620 for (h = 1; h < c->lpt_hght; h++) {
1621 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1622 shft -= UBIFS_LPT_FANOUT_SHIFT;
1623 nnode = ubifs_get_nnode(c, nnode, iip);
1624 if (IS_ERR(nnode))
1625 return ERR_CAST(nnode);
1626 nnode = dirty_cow_nnode(c, nnode);
1627 if (IS_ERR(nnode))
1628 return ERR_CAST(nnode);
1629 }
1630 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
1631 pnode = ubifs_get_pnode(c, nnode, iip);
1632 if (IS_ERR(pnode))
1633 return ERR_CAST(pnode);
1634 pnode = dirty_cow_pnode(c, pnode);
1635 if (IS_ERR(pnode))
1636 return ERR_CAST(pnode);
1637 iip = (i & (UBIFS_LPT_FANOUT - 1));
1638 dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
1639 pnode->lprops[iip].free, pnode->lprops[iip].dirty,
1640 pnode->lprops[iip].flags);
1641 ubifs_assert(c, test_bit(DIRTY_CNODE, &pnode->flags));
1642 return &pnode->lprops[iip];
1643 }
1644
1645 /**
1646 * ubifs_lpt_calc_hash - Calculate hash of the LPT pnodes
1647 * @c: UBIFS file-system description object
1648 * @hash: the returned hash of the LPT pnodes
1649 *
1650 * This function iterates over the LPT pnodes and creates a hash over them.
1651 * Returns 0 for success or a negative error code otherwise.
1652 */
ubifs_lpt_calc_hash(struct ubifs_info * c,u8 * hash)1653 int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
1654 {
1655 struct ubifs_nnode *nnode, *nn;
1656 struct ubifs_cnode *cnode;
1657 struct shash_desc *desc;
1658 int iip = 0, i;
1659 int bufsiz = max_t(int, c->nnode_sz, c->pnode_sz);
1660 void *buf;
1661 int err;
1662
1663 if (!ubifs_authenticated(c))
1664 return 0;
1665
1666 if (!c->nroot) {
1667 err = ubifs_read_nnode(c, NULL, 0);
1668 if (err)
1669 return err;
1670 }
1671
1672 desc = ubifs_hash_get_desc(c);
1673 if (IS_ERR(desc))
1674 return PTR_ERR(desc);
1675
1676 buf = kmalloc(bufsiz, GFP_NOFS);
1677 if (!buf) {
1678 err = -ENOMEM;
1679 goto out;
1680 }
1681
1682 cnode = (struct ubifs_cnode *)c->nroot;
1683
1684 while (cnode) {
1685 nnode = cnode->parent;
1686 nn = (struct ubifs_nnode *)cnode;
1687 if (cnode->level > 1) {
1688 while (iip < UBIFS_LPT_FANOUT) {
1689 if (nn->nbranch[iip].lnum == 0) {
1690 /* Go right */
1691 iip++;
1692 continue;
1693 }
1694
1695 nnode = ubifs_get_nnode(c, nn, iip);
1696 if (IS_ERR(nnode)) {
1697 err = PTR_ERR(nnode);
1698 goto out;
1699 }
1700
1701 /* Go down */
1702 iip = 0;
1703 cnode = (struct ubifs_cnode *)nnode;
1704 break;
1705 }
1706 if (iip < UBIFS_LPT_FANOUT)
1707 continue;
1708 } else {
1709 struct ubifs_pnode *pnode;
1710
1711 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1712 if (nn->nbranch[i].lnum == 0)
1713 continue;
1714 pnode = ubifs_get_pnode(c, nn, i);
1715 if (IS_ERR(pnode)) {
1716 err = PTR_ERR(pnode);
1717 goto out;
1718 }
1719
1720 ubifs_pack_pnode(c, buf, pnode);
1721 err = ubifs_shash_update(c, desc, buf,
1722 c->pnode_sz);
1723 if (err)
1724 goto out;
1725 }
1726 }
1727 /* Go up and to the right */
1728 iip = cnode->iip + 1;
1729 cnode = (struct ubifs_cnode *)nnode;
1730 }
1731
1732 err = ubifs_shash_final(c, desc, hash);
1733 out:
1734 kfree(desc);
1735 kfree(buf);
1736
1737 return err;
1738 }
1739
1740 /**
1741 * lpt_check_hash - check the hash of the LPT.
1742 * @c: UBIFS file-system description object
1743 *
1744 * This function calculates a hash over all pnodes in the LPT and compares it with
1745 * the hash stored in the master node. Returns %0 on success and a negative error
1746 * code on failure.
1747 */
lpt_check_hash(struct ubifs_info * c)1748 static int lpt_check_hash(struct ubifs_info *c)
1749 {
1750 int err;
1751 u8 hash[UBIFS_HASH_ARR_SZ];
1752
1753 if (!ubifs_authenticated(c))
1754 return 0;
1755
1756 err = ubifs_lpt_calc_hash(c, hash);
1757 if (err)
1758 return err;
1759
1760 if (ubifs_check_hash(c, c->mst_node->hash_lpt, hash)) {
1761 err = -EPERM;
1762 ubifs_err(c, "Failed to authenticate LPT");
1763 } else {
1764 err = 0;
1765 }
1766
1767 return err;
1768 }
1769
1770 /**
1771 * lpt_init_rd - initialize the LPT for reading.
1772 * @c: UBIFS file-system description object
1773 *
1774 * This function returns %0 on success and a negative error code on failure.
1775 */
lpt_init_rd(struct ubifs_info * c)1776 static int lpt_init_rd(struct ubifs_info *c)
1777 {
1778 int err, i;
1779
1780 c->ltab = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops),
1781 c->lpt_lebs));
1782 if (!c->ltab)
1783 return -ENOMEM;
1784
1785 i = max_t(int, c->nnode_sz, c->pnode_sz);
1786 c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
1787 if (!c->lpt_nod_buf)
1788 return -ENOMEM;
1789
1790 for (i = 0; i < LPROPS_HEAP_CNT; i++) {
1791 c->lpt_heap[i].arr = kmalloc_array(LPT_HEAP_SZ,
1792 sizeof(void *),
1793 GFP_KERNEL);
1794 if (!c->lpt_heap[i].arr)
1795 return -ENOMEM;
1796 c->lpt_heap[i].cnt = 0;
1797 c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
1798 }
1799
1800 c->dirty_idx.arr = kmalloc_array(LPT_HEAP_SZ, sizeof(void *),
1801 GFP_KERNEL);
1802 if (!c->dirty_idx.arr)
1803 return -ENOMEM;
1804 c->dirty_idx.cnt = 0;
1805 c->dirty_idx.max_cnt = LPT_HEAP_SZ;
1806
1807 err = read_ltab(c);
1808 if (err)
1809 return err;
1810
1811 err = lpt_check_hash(c);
1812 if (err)
1813 return err;
1814
1815 dbg_lp("space_bits %d", c->space_bits);
1816 dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
1817 dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
1818 dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
1819 dbg_lp("pcnt_bits %d", c->pcnt_bits);
1820 dbg_lp("lnum_bits %d", c->lnum_bits);
1821 dbg_lp("pnode_sz %d", c->pnode_sz);
1822 dbg_lp("nnode_sz %d", c->nnode_sz);
1823 dbg_lp("ltab_sz %d", c->ltab_sz);
1824 dbg_lp("lsave_sz %d", c->lsave_sz);
1825 dbg_lp("lsave_cnt %d", c->lsave_cnt);
1826 dbg_lp("lpt_hght %d", c->lpt_hght);
1827 dbg_lp("big_lpt %u", c->big_lpt);
1828 dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
1829 dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
1830 dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
1831 if (c->big_lpt)
1832 dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
1833
1834 return 0;
1835 }
1836
1837 /**
1838 * lpt_init_wr - initialize the LPT for writing.
1839 * @c: UBIFS file-system description object
1840 *
1841 * 'lpt_init_rd()' must have been called already.
1842 *
1843 * This function returns %0 on success and a negative error code on failure.
1844 */
lpt_init_wr(struct ubifs_info * c)1845 static int lpt_init_wr(struct ubifs_info *c)
1846 {
1847 int err, i;
1848
1849 c->ltab_cmt = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops),
1850 c->lpt_lebs));
1851 if (!c->ltab_cmt)
1852 return -ENOMEM;
1853
1854 c->lpt_buf = vmalloc(c->leb_size);
1855 if (!c->lpt_buf)
1856 return -ENOMEM;
1857
1858 if (c->big_lpt) {
1859 c->lsave = kmalloc_array(c->lsave_cnt, sizeof(int), GFP_NOFS);
1860 if (!c->lsave)
1861 return -ENOMEM;
1862 err = read_lsave(c);
1863 if (err)
1864 return err;
1865 }
1866
1867 for (i = 0; i < c->lpt_lebs; i++)
1868 if (c->ltab[i].free == c->leb_size) {
1869 err = ubifs_leb_unmap(c, i + c->lpt_first);
1870 if (err)
1871 return err;
1872 }
1873
1874 return 0;
1875 }
1876
1877 /**
1878 * ubifs_lpt_init - initialize the LPT.
1879 * @c: UBIFS file-system description object
1880 * @rd: whether to initialize lpt for reading
1881 * @wr: whether to initialize lpt for writing
1882 *
1883 * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
1884 * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
1885 * true.
1886 *
1887 * This function returns %0 on success and a negative error code on failure.
1888 */
ubifs_lpt_init(struct ubifs_info * c,int rd,int wr)1889 int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
1890 {
1891 int err;
1892
1893 if (rd) {
1894 err = lpt_init_rd(c);
1895 if (err)
1896 goto out_err;
1897 }
1898
1899 if (wr) {
1900 err = lpt_init_wr(c);
1901 if (err)
1902 goto out_err;
1903 }
1904
1905 return 0;
1906
1907 out_err:
1908 if (wr)
1909 ubifs_lpt_free(c, 1);
1910 if (rd)
1911 ubifs_lpt_free(c, 0);
1912 return err;
1913 }
1914
1915 /**
1916 * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
1917 * @nnode: where to keep a nnode
1918 * @pnode: where to keep a pnode
1919 * @cnode: where to keep a cnode
1920 * @in_tree: is the node in the tree in memory
1921 * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
1922 * the tree
1923 * @ptr.pnode: ditto for pnode
1924 * @ptr.cnode: ditto for cnode
1925 */
1926 struct lpt_scan_node {
1927 union {
1928 struct ubifs_nnode nnode;
1929 struct ubifs_pnode pnode;
1930 struct ubifs_cnode cnode;
1931 };
1932 int in_tree;
1933 union {
1934 struct ubifs_nnode *nnode;
1935 struct ubifs_pnode *pnode;
1936 struct ubifs_cnode *cnode;
1937 } ptr;
1938 };
1939
1940 /**
1941 * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
1942 * @c: the UBIFS file-system description object
1943 * @path: where to put the nnode
1944 * @parent: parent of the nnode
1945 * @iip: index in parent of the nnode
1946 *
1947 * This function returns a pointer to the nnode on success or a negative error
1948 * code on failure.
1949 */
scan_get_nnode(struct ubifs_info * c,struct lpt_scan_node * path,struct ubifs_nnode * parent,int iip)1950 static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
1951 struct lpt_scan_node *path,
1952 struct ubifs_nnode *parent, int iip)
1953 {
1954 struct ubifs_nbranch *branch;
1955 struct ubifs_nnode *nnode;
1956 void *buf = c->lpt_nod_buf;
1957 int err;
1958
1959 branch = &parent->nbranch[iip];
1960 nnode = branch->nnode;
1961 if (nnode) {
1962 path->in_tree = 1;
1963 path->ptr.nnode = nnode;
1964 return nnode;
1965 }
1966 nnode = &path->nnode;
1967 path->in_tree = 0;
1968 path->ptr.nnode = nnode;
1969 memset(nnode, 0, sizeof(struct ubifs_nnode));
1970 if (branch->lnum == 0) {
1971 /*
1972 * This nnode was not written which just means that the LEB
1973 * properties in the subtree below it describe empty LEBs. We
1974 * make the nnode as though we had read it, which in fact means
1975 * doing almost nothing.
1976 */
1977 if (c->big_lpt)
1978 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1979 } else {
1980 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
1981 c->nnode_sz, 1);
1982 if (err)
1983 return ERR_PTR(err);
1984 err = ubifs_unpack_nnode(c, buf, nnode);
1985 if (err)
1986 return ERR_PTR(err);
1987 }
1988 err = validate_nnode(c, nnode, parent, iip);
1989 if (err)
1990 return ERR_PTR(err);
1991 if (!c->big_lpt)
1992 nnode->num = calc_nnode_num_from_parent(c, parent, iip);
1993 nnode->level = parent->level - 1;
1994 nnode->parent = parent;
1995 nnode->iip = iip;
1996 return nnode;
1997 }
1998
1999 /**
2000 * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
2001 * @c: the UBIFS file-system description object
2002 * @path: where to put the pnode
2003 * @parent: parent of the pnode
2004 * @iip: index in parent of the pnode
2005 *
2006 * This function returns a pointer to the pnode on success or a negative error
2007 * code on failure.
2008 */
scan_get_pnode(struct ubifs_info * c,struct lpt_scan_node * path,struct ubifs_nnode * parent,int iip)2009 static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
2010 struct lpt_scan_node *path,
2011 struct ubifs_nnode *parent, int iip)
2012 {
2013 struct ubifs_nbranch *branch;
2014 struct ubifs_pnode *pnode;
2015 void *buf = c->lpt_nod_buf;
2016 int err;
2017
2018 branch = &parent->nbranch[iip];
2019 pnode = branch->pnode;
2020 if (pnode) {
2021 path->in_tree = 1;
2022 path->ptr.pnode = pnode;
2023 return pnode;
2024 }
2025 pnode = &path->pnode;
2026 path->in_tree = 0;
2027 path->ptr.pnode = pnode;
2028 memset(pnode, 0, sizeof(struct ubifs_pnode));
2029 if (branch->lnum == 0) {
2030 /*
2031 * This pnode was not written which just means that the LEB
2032 * properties in it describe empty LEBs. We make the pnode as
2033 * though we had read it.
2034 */
2035 int i;
2036
2037 if (c->big_lpt)
2038 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
2039 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2040 struct ubifs_lprops * const lprops = &pnode->lprops[i];
2041
2042 lprops->free = c->leb_size;
2043 lprops->flags = ubifs_categorize_lprops(c, lprops);
2044 }
2045 } else {
2046 ubifs_assert(c, branch->lnum >= c->lpt_first &&
2047 branch->lnum <= c->lpt_last);
2048 ubifs_assert(c, branch->offs >= 0 && branch->offs < c->leb_size);
2049 err = ubifs_leb_read(c, branch->lnum, buf, branch->offs,
2050 c->pnode_sz, 1);
2051 if (err)
2052 return ERR_PTR(err);
2053 err = unpack_pnode(c, buf, pnode);
2054 if (err)
2055 return ERR_PTR(err);
2056 }
2057 err = validate_pnode(c, pnode, parent, iip);
2058 if (err)
2059 return ERR_PTR(err);
2060 if (!c->big_lpt)
2061 pnode->num = calc_pnode_num_from_parent(c, parent, iip);
2062 pnode->parent = parent;
2063 pnode->iip = iip;
2064 set_pnode_lnum(c, pnode);
2065 return pnode;
2066 }
2067
2068 /**
2069 * ubifs_lpt_scan_nolock - scan the LPT.
2070 * @c: the UBIFS file-system description object
2071 * @start_lnum: LEB number from which to start scanning
2072 * @end_lnum: LEB number at which to stop scanning
2073 * @scan_cb: callback function called for each lprops
2074 * @data: data to be passed to the callback function
2075 *
2076 * This function returns %0 on success and a negative error code on failure.
2077 */
ubifs_lpt_scan_nolock(struct ubifs_info * c,int start_lnum,int end_lnum,ubifs_lpt_scan_callback scan_cb,void * data)2078 int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
2079 ubifs_lpt_scan_callback scan_cb, void *data)
2080 {
2081 int err = 0, i, h, iip, shft;
2082 struct ubifs_nnode *nnode;
2083 struct ubifs_pnode *pnode;
2084 struct lpt_scan_node *path;
2085
2086 if (start_lnum == -1) {
2087 start_lnum = end_lnum + 1;
2088 if (start_lnum >= c->leb_cnt)
2089 start_lnum = c->main_first;
2090 }
2091
2092 ubifs_assert(c, start_lnum >= c->main_first && start_lnum < c->leb_cnt);
2093 ubifs_assert(c, end_lnum >= c->main_first && end_lnum < c->leb_cnt);
2094
2095 if (!c->nroot) {
2096 err = ubifs_read_nnode(c, NULL, 0);
2097 if (err)
2098 return err;
2099 }
2100
2101 path = kmalloc_array(c->lpt_hght + 1, sizeof(struct lpt_scan_node),
2102 GFP_NOFS);
2103 if (!path)
2104 return -ENOMEM;
2105
2106 path[0].ptr.nnode = c->nroot;
2107 path[0].in_tree = 1;
2108 again:
2109 /* Descend to the pnode containing start_lnum */
2110 nnode = c->nroot;
2111 i = start_lnum - c->main_first;
2112 shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
2113 for (h = 1; h < c->lpt_hght; h++) {
2114 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
2115 shft -= UBIFS_LPT_FANOUT_SHIFT;
2116 nnode = scan_get_nnode(c, path + h, nnode, iip);
2117 if (IS_ERR(nnode)) {
2118 err = PTR_ERR(nnode);
2119 goto out;
2120 }
2121 }
2122 iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
2123 pnode = scan_get_pnode(c, path + h, nnode, iip);
2124 if (IS_ERR(pnode)) {
2125 err = PTR_ERR(pnode);
2126 goto out;
2127 }
2128 iip = (i & (UBIFS_LPT_FANOUT - 1));
2129
2130 /* Loop for each lprops */
2131 while (1) {
2132 struct ubifs_lprops *lprops = &pnode->lprops[iip];
2133 int ret, lnum = lprops->lnum;
2134
2135 ret = scan_cb(c, lprops, path[h].in_tree, data);
2136 if (ret < 0) {
2137 err = ret;
2138 goto out;
2139 }
2140 if (ret & LPT_SCAN_ADD) {
2141 /* Add all the nodes in path to the tree in memory */
2142 for (h = 1; h < c->lpt_hght; h++) {
2143 const size_t sz = sizeof(struct ubifs_nnode);
2144 struct ubifs_nnode *parent;
2145
2146 if (path[h].in_tree)
2147 continue;
2148 nnode = kmemdup(&path[h].nnode, sz, GFP_NOFS);
2149 if (!nnode) {
2150 err = -ENOMEM;
2151 goto out;
2152 }
2153 parent = nnode->parent;
2154 parent->nbranch[nnode->iip].nnode = nnode;
2155 path[h].ptr.nnode = nnode;
2156 path[h].in_tree = 1;
2157 path[h + 1].cnode.parent = nnode;
2158 }
2159 if (path[h].in_tree)
2160 ubifs_ensure_cat(c, lprops);
2161 else {
2162 const size_t sz = sizeof(struct ubifs_pnode);
2163 struct ubifs_nnode *parent;
2164
2165 pnode = kmemdup(&path[h].pnode, sz, GFP_NOFS);
2166 if (!pnode) {
2167 err = -ENOMEM;
2168 goto out;
2169 }
2170 parent = pnode->parent;
2171 parent->nbranch[pnode->iip].pnode = pnode;
2172 path[h].ptr.pnode = pnode;
2173 path[h].in_tree = 1;
2174 update_cats(c, pnode);
2175 c->pnodes_have += 1;
2176 }
2177 err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)
2178 c->nroot, 0, 0);
2179 if (err)
2180 goto out;
2181 err = dbg_check_cats(c);
2182 if (err)
2183 goto out;
2184 }
2185 if (ret & LPT_SCAN_STOP) {
2186 err = 0;
2187 break;
2188 }
2189 /* Get the next lprops */
2190 if (lnum == end_lnum) {
2191 /*
2192 * We got to the end without finding what we were
2193 * looking for
2194 */
2195 err = -ENOSPC;
2196 goto out;
2197 }
2198 if (lnum + 1 >= c->leb_cnt) {
2199 /* Wrap-around to the beginning */
2200 start_lnum = c->main_first;
2201 goto again;
2202 }
2203 if (iip + 1 < UBIFS_LPT_FANOUT) {
2204 /* Next lprops is in the same pnode */
2205 iip += 1;
2206 continue;
2207 }
2208 /* We need to get the next pnode. Go up until we can go right */
2209 iip = pnode->iip;
2210 while (1) {
2211 h -= 1;
2212 ubifs_assert(c, h >= 0);
2213 nnode = path[h].ptr.nnode;
2214 if (iip + 1 < UBIFS_LPT_FANOUT)
2215 break;
2216 iip = nnode->iip;
2217 }
2218 /* Go right */
2219 iip += 1;
2220 /* Descend to the pnode */
2221 h += 1;
2222 for (; h < c->lpt_hght; h++) {
2223 nnode = scan_get_nnode(c, path + h, nnode, iip);
2224 if (IS_ERR(nnode)) {
2225 err = PTR_ERR(nnode);
2226 goto out;
2227 }
2228 iip = 0;
2229 }
2230 pnode = scan_get_pnode(c, path + h, nnode, iip);
2231 if (IS_ERR(pnode)) {
2232 err = PTR_ERR(pnode);
2233 goto out;
2234 }
2235 iip = 0;
2236 }
2237 out:
2238 kfree(path);
2239 return err;
2240 }
2241
2242 /**
2243 * dbg_chk_pnode - check a pnode.
2244 * @c: the UBIFS file-system description object
2245 * @pnode: pnode to check
2246 * @col: pnode column
2247 *
2248 * This function returns %0 on success and a negative error code on failure.
2249 */
dbg_chk_pnode(struct ubifs_info * c,struct ubifs_pnode * pnode,int col)2250 static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
2251 int col)
2252 {
2253 int i;
2254
2255 if (pnode->num != col) {
2256 ubifs_err(c, "pnode num %d expected %d parent num %d iip %d",
2257 pnode->num, col, pnode->parent->num, pnode->iip);
2258 return -EINVAL;
2259 }
2260 for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
2261 struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
2262 int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
2263 c->main_first;
2264 int found, cat = lprops->flags & LPROPS_CAT_MASK;
2265 struct ubifs_lpt_heap *heap;
2266 struct list_head *list = NULL;
2267
2268 if (lnum >= c->leb_cnt)
2269 continue;
2270 if (lprops->lnum != lnum) {
2271 ubifs_err(c, "bad LEB number %d expected %d",
2272 lprops->lnum, lnum);
2273 return -EINVAL;
2274 }
2275 if (lprops->flags & LPROPS_TAKEN) {
2276 if (cat != LPROPS_UNCAT) {
2277 ubifs_err(c, "LEB %d taken but not uncat %d",
2278 lprops->lnum, cat);
2279 return -EINVAL;
2280 }
2281 continue;
2282 }
2283 if (lprops->flags & LPROPS_INDEX) {
2284 switch (cat) {
2285 case LPROPS_UNCAT:
2286 case LPROPS_DIRTY_IDX:
2287 case LPROPS_FRDI_IDX:
2288 break;
2289 default:
2290 ubifs_err(c, "LEB %d index but cat %d",
2291 lprops->lnum, cat);
2292 return -EINVAL;
2293 }
2294 } else {
2295 switch (cat) {
2296 case LPROPS_UNCAT:
2297 case LPROPS_DIRTY:
2298 case LPROPS_FREE:
2299 case LPROPS_EMPTY:
2300 case LPROPS_FREEABLE:
2301 break;
2302 default:
2303 ubifs_err(c, "LEB %d not index but cat %d",
2304 lprops->lnum, cat);
2305 return -EINVAL;
2306 }
2307 }
2308 switch (cat) {
2309 case LPROPS_UNCAT:
2310 list = &c->uncat_list;
2311 break;
2312 case LPROPS_EMPTY:
2313 list = &c->empty_list;
2314 break;
2315 case LPROPS_FREEABLE:
2316 list = &c->freeable_list;
2317 break;
2318 case LPROPS_FRDI_IDX:
2319 list = &c->frdi_idx_list;
2320 break;
2321 }
2322 found = 0;
2323 switch (cat) {
2324 case LPROPS_DIRTY:
2325 case LPROPS_DIRTY_IDX:
2326 case LPROPS_FREE:
2327 heap = &c->lpt_heap[cat - 1];
2328 if (lprops->hpos < heap->cnt &&
2329 heap->arr[lprops->hpos] == lprops)
2330 found = 1;
2331 break;
2332 case LPROPS_UNCAT:
2333 case LPROPS_EMPTY:
2334 case LPROPS_FREEABLE:
2335 case LPROPS_FRDI_IDX:
2336 list_for_each_entry(lp, list, list)
2337 if (lprops == lp) {
2338 found = 1;
2339 break;
2340 }
2341 break;
2342 }
2343 if (!found) {
2344 ubifs_err(c, "LEB %d cat %d not found in cat heap/list",
2345 lprops->lnum, cat);
2346 return -EINVAL;
2347 }
2348 switch (cat) {
2349 case LPROPS_EMPTY:
2350 if (lprops->free != c->leb_size) {
2351 ubifs_err(c, "LEB %d cat %d free %d dirty %d",
2352 lprops->lnum, cat, lprops->free,
2353 lprops->dirty);
2354 return -EINVAL;
2355 }
2356 break;
2357 case LPROPS_FREEABLE:
2358 case LPROPS_FRDI_IDX:
2359 if (lprops->free + lprops->dirty != c->leb_size) {
2360 ubifs_err(c, "LEB %d cat %d free %d dirty %d",
2361 lprops->lnum, cat, lprops->free,
2362 lprops->dirty);
2363 return -EINVAL;
2364 }
2365 break;
2366 }
2367 }
2368 return 0;
2369 }
2370
2371 /**
2372 * dbg_check_lpt_nodes - check nnodes and pnodes.
2373 * @c: the UBIFS file-system description object
2374 * @cnode: next cnode (nnode or pnode) to check
2375 * @row: row of cnode (root is zero)
2376 * @col: column of cnode (leftmost is zero)
2377 *
2378 * This function returns %0 on success and a negative error code on failure.
2379 */
dbg_check_lpt_nodes(struct ubifs_info * c,struct ubifs_cnode * cnode,int row,int col)2380 int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
2381 int row, int col)
2382 {
2383 struct ubifs_nnode *nnode, *nn;
2384 struct ubifs_cnode *cn;
2385 int num, iip = 0, err;
2386
2387 if (!dbg_is_chk_lprops(c))
2388 return 0;
2389
2390 while (cnode) {
2391 ubifs_assert(c, row >= 0);
2392 nnode = cnode->parent;
2393 if (cnode->level) {
2394 /* cnode is a nnode */
2395 num = calc_nnode_num(row, col);
2396 if (cnode->num != num) {
2397 ubifs_err(c, "nnode num %d expected %d parent num %d iip %d",
2398 cnode->num, num,
2399 (nnode ? nnode->num : 0), cnode->iip);
2400 return -EINVAL;
2401 }
2402 nn = (struct ubifs_nnode *)cnode;
2403 while (iip < UBIFS_LPT_FANOUT) {
2404 cn = nn->nbranch[iip].cnode;
2405 if (cn) {
2406 /* Go down */
2407 row += 1;
2408 col <<= UBIFS_LPT_FANOUT_SHIFT;
2409 col += iip;
2410 iip = 0;
2411 cnode = cn;
2412 break;
2413 }
2414 /* Go right */
2415 iip += 1;
2416 }
2417 if (iip < UBIFS_LPT_FANOUT)
2418 continue;
2419 } else {
2420 struct ubifs_pnode *pnode;
2421
2422 /* cnode is a pnode */
2423 pnode = (struct ubifs_pnode *)cnode;
2424 err = dbg_chk_pnode(c, pnode, col);
2425 if (err)
2426 return err;
2427 }
2428 /* Go up and to the right */
2429 row -= 1;
2430 col >>= UBIFS_LPT_FANOUT_SHIFT;
2431 iip = cnode->iip + 1;
2432 cnode = (struct ubifs_cnode *)nnode;
2433 }
2434 return 0;
2435 }
2436