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1 | /* |
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 commit-related functionality of the LEB properties | |
25 | * subsystem. | |
26 | */ | |
27 | ||
28 | #include <linux/crc16.h> | |
29 | #include "ubifs.h" | |
30 | ||
31 | /** | |
32 | * first_dirty_cnode - find first dirty cnode. | |
33 | * @c: UBIFS file-system description object | |
34 | * @nnode: nnode at which to start | |
35 | * | |
36 | * This function returns the first dirty cnode or %NULL if there is not one. | |
37 | */ | |
38 | static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode) | |
39 | { | |
40 | ubifs_assert(nnode); | |
41 | while (1) { | |
42 | int i, cont = 0; | |
43 | ||
44 | for (i = 0; i < UBIFS_LPT_FANOUT; i++) { | |
45 | struct ubifs_cnode *cnode; | |
46 | ||
47 | cnode = nnode->nbranch[i].cnode; | |
48 | if (cnode && | |
49 | test_bit(DIRTY_CNODE, &cnode->flags)) { | |
50 | if (cnode->level == 0) | |
51 | return cnode; | |
52 | nnode = (struct ubifs_nnode *)cnode; | |
53 | cont = 1; | |
54 | break; | |
55 | } | |
56 | } | |
57 | if (!cont) | |
58 | return (struct ubifs_cnode *)nnode; | |
59 | } | |
60 | } | |
61 | ||
62 | /** | |
63 | * next_dirty_cnode - find next dirty cnode. | |
64 | * @cnode: cnode from which to begin searching | |
65 | * | |
66 | * This function returns the next dirty cnode or %NULL if there is not one. | |
67 | */ | |
68 | static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode) | |
69 | { | |
70 | struct ubifs_nnode *nnode; | |
71 | int i; | |
72 | ||
73 | ubifs_assert(cnode); | |
74 | nnode = cnode->parent; | |
75 | if (!nnode) | |
76 | return NULL; | |
77 | for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) { | |
78 | cnode = nnode->nbranch[i].cnode; | |
79 | if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) { | |
80 | if (cnode->level == 0) | |
81 | return cnode; /* cnode is a pnode */ | |
82 | /* cnode is a nnode */ | |
83 | return first_dirty_cnode((struct ubifs_nnode *)cnode); | |
84 | } | |
85 | } | |
86 | return (struct ubifs_cnode *)nnode; | |
87 | } | |
88 | ||
89 | /** | |
90 | * get_cnodes_to_commit - create list of dirty cnodes to commit. | |
91 | * @c: UBIFS file-system description object | |
92 | * | |
93 | * This function returns the number of cnodes to commit. | |
94 | */ | |
95 | static int get_cnodes_to_commit(struct ubifs_info *c) | |
96 | { | |
97 | struct ubifs_cnode *cnode, *cnext; | |
98 | int cnt = 0; | |
99 | ||
100 | if (!c->nroot) | |
101 | return 0; | |
102 | ||
103 | if (!test_bit(DIRTY_CNODE, &c->nroot->flags)) | |
104 | return 0; | |
105 | ||
106 | c->lpt_cnext = first_dirty_cnode(c->nroot); | |
107 | cnode = c->lpt_cnext; | |
108 | if (!cnode) | |
109 | return 0; | |
110 | cnt += 1; | |
111 | while (1) { | |
112 | ubifs_assert(!test_bit(COW_ZNODE, &cnode->flags)); | |
113 | __set_bit(COW_ZNODE, &cnode->flags); | |
114 | cnext = next_dirty_cnode(cnode); | |
115 | if (!cnext) { | |
116 | cnode->cnext = c->lpt_cnext; | |
117 | break; | |
118 | } | |
119 | cnode->cnext = cnext; | |
120 | cnode = cnext; | |
121 | cnt += 1; | |
122 | } | |
123 | dbg_cmt("committing %d cnodes", cnt); | |
124 | dbg_lp("committing %d cnodes", cnt); | |
125 | ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt); | |
126 | return cnt; | |
127 | } | |
128 | ||
129 | /** | |
130 | * upd_ltab - update LPT LEB properties. | |
131 | * @c: UBIFS file-system description object | |
132 | * @lnum: LEB number | |
133 | * @free: amount of free space | |
134 | * @dirty: amount of dirty space to add | |
135 | */ | |
136 | static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty) | |
137 | { | |
138 | dbg_lp("LEB %d free %d dirty %d to %d +%d", | |
139 | lnum, c->ltab[lnum - c->lpt_first].free, | |
140 | c->ltab[lnum - c->lpt_first].dirty, free, dirty); | |
141 | ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last); | |
142 | c->ltab[lnum - c->lpt_first].free = free; | |
143 | c->ltab[lnum - c->lpt_first].dirty += dirty; | |
144 | } | |
145 | ||
146 | /** | |
147 | * alloc_lpt_leb - allocate an LPT LEB that is empty. | |
148 | * @c: UBIFS file-system description object | |
149 | * @lnum: LEB number is passed and returned here | |
150 | * | |
151 | * This function finds the next empty LEB in the ltab starting from @lnum. If a | |
152 | * an empty LEB is found it is returned in @lnum and the function returns %0. | |
153 | * Otherwise the function returns -ENOSPC. Note however, that LPT is designed | |
154 | * never to run out of space. | |
155 | */ | |
156 | static int alloc_lpt_leb(struct ubifs_info *c, int *lnum) | |
157 | { | |
158 | int i, n; | |
159 | ||
160 | n = *lnum - c->lpt_first + 1; | |
161 | for (i = n; i < c->lpt_lebs; i++) { | |
162 | if (c->ltab[i].tgc || c->ltab[i].cmt) | |
163 | continue; | |
164 | if (c->ltab[i].free == c->leb_size) { | |
165 | c->ltab[i].cmt = 1; | |
166 | *lnum = i + c->lpt_first; | |
167 | return 0; | |
168 | } | |
169 | } | |
170 | ||
171 | for (i = 0; i < n; i++) { | |
172 | if (c->ltab[i].tgc || c->ltab[i].cmt) | |
173 | continue; | |
174 | if (c->ltab[i].free == c->leb_size) { | |
175 | c->ltab[i].cmt = 1; | |
176 | *lnum = i + c->lpt_first; | |
177 | return 0; | |
178 | } | |
179 | } | |
180 | dbg_err("last LEB %d", *lnum); | |
181 | dump_stack(); | |
182 | return -ENOSPC; | |
183 | } | |
184 | ||
185 | /** | |
186 | * layout_cnodes - layout cnodes for commit. | |
187 | * @c: UBIFS file-system description object | |
188 | * | |
189 | * This function returns %0 on success and a negative error code on failure. | |
190 | */ | |
191 | static int layout_cnodes(struct ubifs_info *c) | |
192 | { | |
193 | int lnum, offs, len, alen, done_lsave, done_ltab, err; | |
194 | struct ubifs_cnode *cnode; | |
195 | ||
196 | cnode = c->lpt_cnext; | |
197 | if (!cnode) | |
198 | return 0; | |
199 | lnum = c->nhead_lnum; | |
200 | offs = c->nhead_offs; | |
201 | /* Try to place lsave and ltab nicely */ | |
202 | done_lsave = !c->big_lpt; | |
203 | done_ltab = 0; | |
204 | if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { | |
205 | done_lsave = 1; | |
206 | c->lsave_lnum = lnum; | |
207 | c->lsave_offs = offs; | |
208 | offs += c->lsave_sz; | |
209 | } | |
210 | ||
211 | if (offs + c->ltab_sz <= c->leb_size) { | |
212 | done_ltab = 1; | |
213 | c->ltab_lnum = lnum; | |
214 | c->ltab_offs = offs; | |
215 | offs += c->ltab_sz; | |
216 | } | |
217 | ||
218 | do { | |
219 | if (cnode->level) { | |
220 | len = c->nnode_sz; | |
221 | c->dirty_nn_cnt -= 1; | |
222 | } else { | |
223 | len = c->pnode_sz; | |
224 | c->dirty_pn_cnt -= 1; | |
225 | } | |
226 | while (offs + len > c->leb_size) { | |
227 | alen = ALIGN(offs, c->min_io_size); | |
228 | upd_ltab(c, lnum, c->leb_size - alen, alen - offs); | |
229 | err = alloc_lpt_leb(c, &lnum); | |
230 | if (err) | |
231 | return err; | |
232 | offs = 0; | |
233 | ubifs_assert(lnum >= c->lpt_first && | |
234 | lnum <= c->lpt_last); | |
235 | /* Try to place lsave and ltab nicely */ | |
236 | if (!done_lsave) { | |
237 | done_lsave = 1; | |
238 | c->lsave_lnum = lnum; | |
239 | c->lsave_offs = offs; | |
240 | offs += c->lsave_sz; | |
241 | continue; | |
242 | } | |
243 | if (!done_ltab) { | |
244 | done_ltab = 1; | |
245 | c->ltab_lnum = lnum; | |
246 | c->ltab_offs = offs; | |
247 | offs += c->ltab_sz; | |
248 | continue; | |
249 | } | |
250 | break; | |
251 | } | |
252 | if (cnode->parent) { | |
253 | cnode->parent->nbranch[cnode->iip].lnum = lnum; | |
254 | cnode->parent->nbranch[cnode->iip].offs = offs; | |
255 | } else { | |
256 | c->lpt_lnum = lnum; | |
257 | c->lpt_offs = offs; | |
258 | } | |
259 | offs += len; | |
260 | cnode = cnode->cnext; | |
261 | } while (cnode && cnode != c->lpt_cnext); | |
262 | ||
263 | /* Make sure to place LPT's save table */ | |
264 | if (!done_lsave) { | |
265 | if (offs + c->lsave_sz > c->leb_size) { | |
266 | alen = ALIGN(offs, c->min_io_size); | |
267 | upd_ltab(c, lnum, c->leb_size - alen, alen - offs); | |
268 | err = alloc_lpt_leb(c, &lnum); | |
269 | if (err) | |
270 | return err; | |
271 | offs = 0; | |
272 | ubifs_assert(lnum >= c->lpt_first && | |
273 | lnum <= c->lpt_last); | |
274 | } | |
275 | done_lsave = 1; | |
276 | c->lsave_lnum = lnum; | |
277 | c->lsave_offs = offs; | |
278 | offs += c->lsave_sz; | |
279 | } | |
280 | ||
281 | /* Make sure to place LPT's own lprops table */ | |
282 | if (!done_ltab) { | |
283 | if (offs + c->ltab_sz > c->leb_size) { | |
284 | alen = ALIGN(offs, c->min_io_size); | |
285 | upd_ltab(c, lnum, c->leb_size - alen, alen - offs); | |
286 | err = alloc_lpt_leb(c, &lnum); | |
287 | if (err) | |
288 | return err; | |
289 | offs = 0; | |
290 | ubifs_assert(lnum >= c->lpt_first && | |
291 | lnum <= c->lpt_last); | |
292 | } | |
293 | done_ltab = 1; | |
294 | c->ltab_lnum = lnum; | |
295 | c->ltab_offs = offs; | |
296 | offs += c->ltab_sz; | |
297 | } | |
298 | ||
299 | alen = ALIGN(offs, c->min_io_size); | |
300 | upd_ltab(c, lnum, c->leb_size - alen, alen - offs); | |
301 | return 0; | |
302 | } | |
303 | ||
304 | /** | |
305 | * realloc_lpt_leb - allocate an LPT LEB that is empty. | |
306 | * @c: UBIFS file-system description object | |
307 | * @lnum: LEB number is passed and returned here | |
308 | * | |
309 | * This function duplicates exactly the results of the function alloc_lpt_leb. | |
310 | * It is used during end commit to reallocate the same LEB numbers that were | |
311 | * allocated by alloc_lpt_leb during start commit. | |
312 | * | |
313 | * This function finds the next LEB that was allocated by the alloc_lpt_leb | |
314 | * function starting from @lnum. If a LEB is found it is returned in @lnum and | |
315 | * the function returns %0. Otherwise the function returns -ENOSPC. | |
316 | * Note however, that LPT is designed never to run out of space. | |
317 | */ | |
318 | static int realloc_lpt_leb(struct ubifs_info *c, int *lnum) | |
319 | { | |
320 | int i, n; | |
321 | ||
322 | n = *lnum - c->lpt_first + 1; | |
323 | for (i = n; i < c->lpt_lebs; i++) | |
324 | if (c->ltab[i].cmt) { | |
325 | c->ltab[i].cmt = 0; | |
326 | *lnum = i + c->lpt_first; | |
327 | return 0; | |
328 | } | |
329 | ||
330 | for (i = 0; i < n; i++) | |
331 | if (c->ltab[i].cmt) { | |
332 | c->ltab[i].cmt = 0; | |
333 | *lnum = i + c->lpt_first; | |
334 | return 0; | |
335 | } | |
336 | dbg_err("last LEB %d", *lnum); | |
337 | dump_stack(); | |
338 | return -ENOSPC; | |
339 | } | |
340 | ||
341 | /** | |
342 | * write_cnodes - write cnodes for commit. | |
343 | * @c: UBIFS file-system description object | |
344 | * | |
345 | * This function returns %0 on success and a negative error code on failure. | |
346 | */ | |
347 | static int write_cnodes(struct ubifs_info *c) | |
348 | { | |
349 | int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave; | |
350 | struct ubifs_cnode *cnode; | |
351 | void *buf = c->lpt_buf; | |
352 | ||
353 | cnode = c->lpt_cnext; | |
354 | if (!cnode) | |
355 | return 0; | |
356 | lnum = c->nhead_lnum; | |
357 | offs = c->nhead_offs; | |
358 | from = offs; | |
359 | /* Ensure empty LEB is unmapped */ | |
360 | if (offs == 0) { | |
361 | err = ubifs_leb_unmap(c, lnum); | |
362 | if (err) | |
363 | return err; | |
364 | } | |
365 | /* Try to place lsave and ltab nicely */ | |
366 | done_lsave = !c->big_lpt; | |
367 | done_ltab = 0; | |
368 | if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { | |
369 | done_lsave = 1; | |
370 | ubifs_pack_lsave(c, buf + offs, c->lsave); | |
371 | offs += c->lsave_sz; | |
372 | } | |
373 | ||
374 | if (offs + c->ltab_sz <= c->leb_size) { | |
375 | done_ltab = 1; | |
376 | ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); | |
377 | offs += c->ltab_sz; | |
378 | } | |
379 | ||
380 | /* Loop for each cnode */ | |
381 | do { | |
382 | if (cnode->level) | |
383 | len = c->nnode_sz; | |
384 | else | |
385 | len = c->pnode_sz; | |
386 | while (offs + len > c->leb_size) { | |
387 | wlen = offs - from; | |
388 | if (wlen) { | |
389 | alen = ALIGN(wlen, c->min_io_size); | |
390 | memset(buf + offs, 0xff, alen - wlen); | |
391 | err = ubifs_leb_write(c, lnum, buf + from, from, | |
392 | alen, UBI_SHORTTERM); | |
393 | if (err) | |
394 | return err; | |
395 | } | |
396 | err = realloc_lpt_leb(c, &lnum); | |
397 | if (err) | |
398 | return err; | |
399 | offs = 0; | |
400 | from = 0; | |
401 | ubifs_assert(lnum >= c->lpt_first && | |
402 | lnum <= c->lpt_last); | |
403 | err = ubifs_leb_unmap(c, lnum); | |
404 | if (err) | |
405 | return err; | |
406 | /* Try to place lsave and ltab nicely */ | |
407 | if (!done_lsave) { | |
408 | done_lsave = 1; | |
409 | ubifs_pack_lsave(c, buf + offs, c->lsave); | |
410 | offs += c->lsave_sz; | |
411 | continue; | |
412 | } | |
413 | if (!done_ltab) { | |
414 | done_ltab = 1; | |
415 | ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); | |
416 | offs += c->ltab_sz; | |
417 | continue; | |
418 | } | |
419 | break; | |
420 | } | |
421 | if (cnode->level) | |
422 | ubifs_pack_nnode(c, buf + offs, | |
423 | (struct ubifs_nnode *)cnode); | |
424 | else | |
425 | ubifs_pack_pnode(c, buf + offs, | |
426 | (struct ubifs_pnode *)cnode); | |
427 | /* | |
428 | * The reason for the barriers is the same as in case of TNC. | |
429 | * See comment in 'write_index()'. 'dirty_cow_nnode()' and | |
430 | * 'dirty_cow_pnode()' are the functions for which this is | |
431 | * important. | |
432 | */ | |
433 | clear_bit(DIRTY_CNODE, &cnode->flags); | |
434 | smp_mb__before_clear_bit(); | |
435 | clear_bit(COW_ZNODE, &cnode->flags); | |
436 | smp_mb__after_clear_bit(); | |
437 | offs += len; | |
438 | cnode = cnode->cnext; | |
439 | } while (cnode && cnode != c->lpt_cnext); | |
440 | ||
441 | /* Make sure to place LPT's save table */ | |
442 | if (!done_lsave) { | |
443 | if (offs + c->lsave_sz > c->leb_size) { | |
444 | wlen = offs - from; | |
445 | alen = ALIGN(wlen, c->min_io_size); | |
446 | memset(buf + offs, 0xff, alen - wlen); | |
447 | err = ubifs_leb_write(c, lnum, buf + from, from, alen, | |
448 | UBI_SHORTTERM); | |
449 | if (err) | |
450 | return err; | |
451 | err = realloc_lpt_leb(c, &lnum); | |
452 | if (err) | |
453 | return err; | |
454 | offs = 0; | |
455 | ubifs_assert(lnum >= c->lpt_first && | |
456 | lnum <= c->lpt_last); | |
457 | err = ubifs_leb_unmap(c, lnum); | |
458 | if (err) | |
459 | return err; | |
460 | } | |
461 | done_lsave = 1; | |
462 | ubifs_pack_lsave(c, buf + offs, c->lsave); | |
463 | offs += c->lsave_sz; | |
464 | } | |
465 | ||
466 | /* Make sure to place LPT's own lprops table */ | |
467 | if (!done_ltab) { | |
468 | if (offs + c->ltab_sz > c->leb_size) { | |
469 | wlen = offs - from; | |
470 | alen = ALIGN(wlen, c->min_io_size); | |
471 | memset(buf + offs, 0xff, alen - wlen); | |
472 | err = ubifs_leb_write(c, lnum, buf + from, from, alen, | |
473 | UBI_SHORTTERM); | |
474 | if (err) | |
475 | return err; | |
476 | err = realloc_lpt_leb(c, &lnum); | |
477 | if (err) | |
478 | return err; | |
479 | offs = 0; | |
480 | ubifs_assert(lnum >= c->lpt_first && | |
481 | lnum <= c->lpt_last); | |
482 | err = ubifs_leb_unmap(c, lnum); | |
483 | if (err) | |
484 | return err; | |
485 | } | |
486 | done_ltab = 1; | |
487 | ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); | |
488 | offs += c->ltab_sz; | |
489 | } | |
490 | ||
491 | /* Write remaining data in buffer */ | |
492 | wlen = offs - from; | |
493 | alen = ALIGN(wlen, c->min_io_size); | |
494 | memset(buf + offs, 0xff, alen - wlen); | |
495 | err = ubifs_leb_write(c, lnum, buf + from, from, alen, UBI_SHORTTERM); | |
496 | if (err) | |
497 | return err; | |
498 | c->nhead_lnum = lnum; | |
499 | c->nhead_offs = ALIGN(offs, c->min_io_size); | |
500 | ||
501 | dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs); | |
502 | dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs); | |
503 | dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs); | |
504 | if (c->big_lpt) | |
505 | dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs); | |
506 | return 0; | |
507 | } | |
508 | ||
509 | /** | |
510 | * next_pnode - find next pnode. | |
511 | * @c: UBIFS file-system description object | |
512 | * @pnode: pnode | |
513 | * | |
514 | * This function returns the next pnode or %NULL if there are no more pnodes. | |
515 | */ | |
516 | static struct ubifs_pnode *next_pnode(struct ubifs_info *c, | |
517 | struct ubifs_pnode *pnode) | |
518 | { | |
519 | struct ubifs_nnode *nnode; | |
520 | int iip; | |
521 | ||
522 | /* Try to go right */ | |
523 | nnode = pnode->parent; | |
524 | iip = pnode->iip + 1; | |
525 | if (iip < UBIFS_LPT_FANOUT) { | |
526 | /* We assume here that LEB zero is never an LPT LEB */ | |
527 | if (nnode->nbranch[iip].lnum) | |
528 | return ubifs_get_pnode(c, nnode, iip); | |
529 | else | |
530 | return NULL; | |
531 | } | |
532 | ||
533 | /* Go up while can't go right */ | |
534 | do { | |
535 | iip = nnode->iip + 1; | |
536 | nnode = nnode->parent; | |
537 | if (!nnode) | |
538 | return NULL; | |
539 | /* We assume here that LEB zero is never an LPT LEB */ | |
540 | } while (iip >= UBIFS_LPT_FANOUT || !nnode->nbranch[iip].lnum); | |
541 | ||
542 | /* Go right */ | |
543 | nnode = ubifs_get_nnode(c, nnode, iip); | |
544 | if (IS_ERR(nnode)) | |
545 | return (void *)nnode; | |
546 | ||
547 | /* Go down to level 1 */ | |
548 | while (nnode->level > 1) { | |
549 | nnode = ubifs_get_nnode(c, nnode, 0); | |
550 | if (IS_ERR(nnode)) | |
551 | return (void *)nnode; | |
552 | } | |
553 | ||
554 | return ubifs_get_pnode(c, nnode, 0); | |
555 | } | |
556 | ||
557 | /** | |
558 | * pnode_lookup - lookup a pnode in the LPT. | |
559 | * @c: UBIFS file-system description object | |
560 | * @i: pnode number (0 to main_lebs - 1) | |
561 | * | |
562 | * This function returns a pointer to the pnode on success or a negative | |
563 | * error code on failure. | |
564 | */ | |
565 | static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i) | |
566 | { | |
567 | int err, h, iip, shft; | |
568 | struct ubifs_nnode *nnode; | |
569 | ||
570 | if (!c->nroot) { | |
571 | err = ubifs_read_nnode(c, NULL, 0); | |
572 | if (err) | |
573 | return ERR_PTR(err); | |
574 | } | |
575 | i <<= UBIFS_LPT_FANOUT_SHIFT; | |
576 | nnode = c->nroot; | |
577 | shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT; | |
578 | for (h = 1; h < c->lpt_hght; h++) { | |
579 | iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); | |
580 | shft -= UBIFS_LPT_FANOUT_SHIFT; | |
581 | nnode = ubifs_get_nnode(c, nnode, iip); | |
582 | if (IS_ERR(nnode)) | |
583 | return ERR_PTR(PTR_ERR(nnode)); | |
584 | } | |
585 | iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); | |
586 | return ubifs_get_pnode(c, nnode, iip); | |
587 | } | |
588 | ||
589 | /** | |
590 | * add_pnode_dirt - add dirty space to LPT LEB properties. | |
591 | * @c: UBIFS file-system description object | |
592 | * @pnode: pnode for which to add dirt | |
593 | */ | |
594 | static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode) | |
595 | { | |
596 | ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum, | |
597 | c->pnode_sz); | |
598 | } | |
599 | ||
600 | /** | |
601 | * do_make_pnode_dirty - mark a pnode dirty. | |
602 | * @c: UBIFS file-system description object | |
603 | * @pnode: pnode to mark dirty | |
604 | */ | |
605 | static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode) | |
606 | { | |
607 | /* Assumes cnext list is empty i.e. not called during commit */ | |
608 | if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) { | |
609 | struct ubifs_nnode *nnode; | |
610 | ||
611 | c->dirty_pn_cnt += 1; | |
612 | add_pnode_dirt(c, pnode); | |
613 | /* Mark parent and ancestors dirty too */ | |
614 | nnode = pnode->parent; | |
615 | while (nnode) { | |
616 | if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { | |
617 | c->dirty_nn_cnt += 1; | |
618 | ubifs_add_nnode_dirt(c, nnode); | |
619 | nnode = nnode->parent; | |
620 | } else | |
621 | break; | |
622 | } | |
623 | } | |
624 | } | |
625 | ||
626 | /** | |
627 | * make_tree_dirty - mark the entire LEB properties tree dirty. | |
628 | * @c: UBIFS file-system description object | |
629 | * | |
630 | * This function is used by the "small" LPT model to cause the entire LEB | |
631 | * properties tree to be written. The "small" LPT model does not use LPT | |
632 | * garbage collection because it is more efficient to write the entire tree | |
633 | * (because it is small). | |
634 | * | |
635 | * This function returns %0 on success and a negative error code on failure. | |
636 | */ | |
637 | static int make_tree_dirty(struct ubifs_info *c) | |
638 | { | |
639 | struct ubifs_pnode *pnode; | |
640 | ||
641 | pnode = pnode_lookup(c, 0); | |
642 | while (pnode) { | |
643 | do_make_pnode_dirty(c, pnode); | |
644 | pnode = next_pnode(c, pnode); | |
645 | if (IS_ERR(pnode)) | |
646 | return PTR_ERR(pnode); | |
647 | } | |
648 | return 0; | |
649 | } | |
650 | ||
651 | /** | |
652 | * need_write_all - determine if the LPT area is running out of free space. | |
653 | * @c: UBIFS file-system description object | |
654 | * | |
655 | * This function returns %1 if the LPT area is running out of free space and %0 | |
656 | * if it is not. | |
657 | */ | |
658 | static int need_write_all(struct ubifs_info *c) | |
659 | { | |
660 | long long free = 0; | |
661 | int i; | |
662 | ||
663 | for (i = 0; i < c->lpt_lebs; i++) { | |
664 | if (i + c->lpt_first == c->nhead_lnum) | |
665 | free += c->leb_size - c->nhead_offs; | |
666 | else if (c->ltab[i].free == c->leb_size) | |
667 | free += c->leb_size; | |
668 | else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size) | |
669 | free += c->leb_size; | |
670 | } | |
671 | /* Less than twice the size left */ | |
672 | if (free <= c->lpt_sz * 2) | |
673 | return 1; | |
674 | return 0; | |
675 | } | |
676 | ||
677 | /** | |
678 | * lpt_tgc_start - start trivial garbage collection of LPT LEBs. | |
679 | * @c: UBIFS file-system description object | |
680 | * | |
681 | * LPT trivial garbage collection is where a LPT LEB contains only dirty and | |
682 | * free space and so may be reused as soon as the next commit is completed. | |
683 | * This function is called during start commit to mark LPT LEBs for trivial GC. | |
684 | */ | |
685 | static void lpt_tgc_start(struct ubifs_info *c) | |
686 | { | |
687 | int i; | |
688 | ||
689 | for (i = 0; i < c->lpt_lebs; i++) { | |
690 | if (i + c->lpt_first == c->nhead_lnum) | |
691 | continue; | |
692 | if (c->ltab[i].dirty > 0 && | |
693 | c->ltab[i].free + c->ltab[i].dirty == c->leb_size) { | |
694 | c->ltab[i].tgc = 1; | |
695 | c->ltab[i].free = c->leb_size; | |
696 | c->ltab[i].dirty = 0; | |
697 | dbg_lp("LEB %d", i + c->lpt_first); | |
698 | } | |
699 | } | |
700 | } | |
701 | ||
702 | /** | |
703 | * lpt_tgc_end - end trivial garbage collection of LPT LEBs. | |
704 | * @c: UBIFS file-system description object | |
705 | * | |
706 | * LPT trivial garbage collection is where a LPT LEB contains only dirty and | |
707 | * free space and so may be reused as soon as the next commit is completed. | |
708 | * This function is called after the commit is completed (master node has been | |
709 | * written) and unmaps LPT LEBs that were marked for trivial GC. | |
710 | */ | |
711 | static int lpt_tgc_end(struct ubifs_info *c) | |
712 | { | |
713 | int i, err; | |
714 | ||
715 | for (i = 0; i < c->lpt_lebs; i++) | |
716 | if (c->ltab[i].tgc) { | |
717 | err = ubifs_leb_unmap(c, i + c->lpt_first); | |
718 | if (err) | |
719 | return err; | |
720 | c->ltab[i].tgc = 0; | |
721 | dbg_lp("LEB %d", i + c->lpt_first); | |
722 | } | |
723 | return 0; | |
724 | } | |
725 | ||
726 | /** | |
727 | * populate_lsave - fill the lsave array with important LEB numbers. | |
728 | * @c: the UBIFS file-system description object | |
729 | * | |
730 | * This function is only called for the "big" model. It records a small number | |
731 | * of LEB numbers of important LEBs. Important LEBs are ones that are (from | |
732 | * most important to least important): empty, freeable, freeable index, dirty | |
733 | * index, dirty or free. Upon mount, we read this list of LEB numbers and bring | |
734 | * their pnodes into memory. That will stop us from having to scan the LPT | |
735 | * straight away. For the "small" model we assume that scanning the LPT is no | |
736 | * big deal. | |
737 | */ | |
738 | static void populate_lsave(struct ubifs_info *c) | |
739 | { | |
740 | struct ubifs_lprops *lprops; | |
741 | struct ubifs_lpt_heap *heap; | |
742 | int i, cnt = 0; | |
743 | ||
744 | ubifs_assert(c->big_lpt); | |
745 | if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { | |
746 | c->lpt_drty_flgs |= LSAVE_DIRTY; | |
747 | ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); | |
748 | } | |
749 | list_for_each_entry(lprops, &c->empty_list, list) { | |
750 | c->lsave[cnt++] = lprops->lnum; | |
751 | if (cnt >= c->lsave_cnt) | |
752 | return; | |
753 | } | |
754 | list_for_each_entry(lprops, &c->freeable_list, list) { | |
755 | c->lsave[cnt++] = lprops->lnum; | |
756 | if (cnt >= c->lsave_cnt) | |
757 | return; | |
758 | } | |
759 | list_for_each_entry(lprops, &c->frdi_idx_list, list) { | |
760 | c->lsave[cnt++] = lprops->lnum; | |
761 | if (cnt >= c->lsave_cnt) | |
762 | return; | |
763 | } | |
764 | heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; | |
765 | for (i = 0; i < heap->cnt; i++) { | |
766 | c->lsave[cnt++] = heap->arr[i]->lnum; | |
767 | if (cnt >= c->lsave_cnt) | |
768 | return; | |
769 | } | |
770 | heap = &c->lpt_heap[LPROPS_DIRTY - 1]; | |
771 | for (i = 0; i < heap->cnt; i++) { | |
772 | c->lsave[cnt++] = heap->arr[i]->lnum; | |
773 | if (cnt >= c->lsave_cnt) | |
774 | return; | |
775 | } | |
776 | heap = &c->lpt_heap[LPROPS_FREE - 1]; | |
777 | for (i = 0; i < heap->cnt; i++) { | |
778 | c->lsave[cnt++] = heap->arr[i]->lnum; | |
779 | if (cnt >= c->lsave_cnt) | |
780 | return; | |
781 | } | |
782 | /* Fill it up completely */ | |
783 | while (cnt < c->lsave_cnt) | |
784 | c->lsave[cnt++] = c->main_first; | |
785 | } | |
786 | ||
787 | /** | |
788 | * nnode_lookup - lookup a nnode in the LPT. | |
789 | * @c: UBIFS file-system description object | |
790 | * @i: nnode number | |
791 | * | |
792 | * This function returns a pointer to the nnode on success or a negative | |
793 | * error code on failure. | |
794 | */ | |
795 | static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i) | |
796 | { | |
797 | int err, iip; | |
798 | struct ubifs_nnode *nnode; | |
799 | ||
800 | if (!c->nroot) { | |
801 | err = ubifs_read_nnode(c, NULL, 0); | |
802 | if (err) | |
803 | return ERR_PTR(err); | |
804 | } | |
805 | nnode = c->nroot; | |
806 | while (1) { | |
807 | iip = i & (UBIFS_LPT_FANOUT - 1); | |
808 | i >>= UBIFS_LPT_FANOUT_SHIFT; | |
809 | if (!i) | |
810 | break; | |
811 | nnode = ubifs_get_nnode(c, nnode, iip); | |
812 | if (IS_ERR(nnode)) | |
813 | return nnode; | |
814 | } | |
815 | return nnode; | |
816 | } | |
817 | ||
818 | /** | |
819 | * make_nnode_dirty - find a nnode and, if found, make it dirty. | |
820 | * @c: UBIFS file-system description object | |
821 | * @node_num: nnode number of nnode to make dirty | |
822 | * @lnum: LEB number where nnode was written | |
823 | * @offs: offset where nnode was written | |
824 | * | |
825 | * This function is used by LPT garbage collection. LPT garbage collection is | |
826 | * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection | |
827 | * simply involves marking all the nodes in the LEB being garbage-collected as | |
828 | * dirty. The dirty nodes are written next commit, after which the LEB is free | |
829 | * to be reused. | |
830 | * | |
831 | * This function returns %0 on success and a negative error code on failure. | |
832 | */ | |
833 | static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum, | |
834 | int offs) | |
835 | { | |
836 | struct ubifs_nnode *nnode; | |
837 | ||
838 | nnode = nnode_lookup(c, node_num); | |
839 | if (IS_ERR(nnode)) | |
840 | return PTR_ERR(nnode); | |
841 | if (nnode->parent) { | |
842 | struct ubifs_nbranch *branch; | |
843 | ||
844 | branch = &nnode->parent->nbranch[nnode->iip]; | |
845 | if (branch->lnum != lnum || branch->offs != offs) | |
846 | return 0; /* nnode is obsolete */ | |
847 | } else if (c->lpt_lnum != lnum || c->lpt_offs != offs) | |
848 | return 0; /* nnode is obsolete */ | |
849 | /* Assumes cnext list is empty i.e. not called during commit */ | |
850 | if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { | |
851 | c->dirty_nn_cnt += 1; | |
852 | ubifs_add_nnode_dirt(c, nnode); | |
853 | /* Mark parent and ancestors dirty too */ | |
854 | nnode = nnode->parent; | |
855 | while (nnode) { | |
856 | if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { | |
857 | c->dirty_nn_cnt += 1; | |
858 | ubifs_add_nnode_dirt(c, nnode); | |
859 | nnode = nnode->parent; | |
860 | } else | |
861 | break; | |
862 | } | |
863 | } | |
864 | return 0; | |
865 | } | |
866 | ||
867 | /** | |
868 | * make_pnode_dirty - find a pnode and, if found, make it dirty. | |
869 | * @c: UBIFS file-system description object | |
870 | * @node_num: pnode number of pnode to make dirty | |
871 | * @lnum: LEB number where pnode was written | |
872 | * @offs: offset where pnode was written | |
873 | * | |
874 | * This function is used by LPT garbage collection. LPT garbage collection is | |
875 | * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection | |
876 | * simply involves marking all the nodes in the LEB being garbage-collected as | |
877 | * dirty. The dirty nodes are written next commit, after which the LEB is free | |
878 | * to be reused. | |
879 | * | |
880 | * This function returns %0 on success and a negative error code on failure. | |
881 | */ | |
882 | static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum, | |
883 | int offs) | |
884 | { | |
885 | struct ubifs_pnode *pnode; | |
886 | struct ubifs_nbranch *branch; | |
887 | ||
888 | pnode = pnode_lookup(c, node_num); | |
889 | if (IS_ERR(pnode)) | |
890 | return PTR_ERR(pnode); | |
891 | branch = &pnode->parent->nbranch[pnode->iip]; | |
892 | if (branch->lnum != lnum || branch->offs != offs) | |
893 | return 0; | |
894 | do_make_pnode_dirty(c, pnode); | |
895 | return 0; | |
896 | } | |
897 | ||
898 | /** | |
899 | * make_ltab_dirty - make ltab node dirty. | |
900 | * @c: UBIFS file-system description object | |
901 | * @lnum: LEB number where ltab was written | |
902 | * @offs: offset where ltab was written | |
903 | * | |
904 | * This function is used by LPT garbage collection. LPT garbage collection is | |
905 | * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection | |
906 | * simply involves marking all the nodes in the LEB being garbage-collected as | |
907 | * dirty. The dirty nodes are written next commit, after which the LEB is free | |
908 | * to be reused. | |
909 | * | |
910 | * This function returns %0 on success and a negative error code on failure. | |
911 | */ | |
912 | static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs) | |
913 | { | |
914 | if (lnum != c->ltab_lnum || offs != c->ltab_offs) | |
915 | return 0; /* This ltab node is obsolete */ | |
916 | if (!(c->lpt_drty_flgs & LTAB_DIRTY)) { | |
917 | c->lpt_drty_flgs |= LTAB_DIRTY; | |
918 | ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz); | |
919 | } | |
920 | return 0; | |
921 | } | |
922 | ||
923 | /** | |
924 | * make_lsave_dirty - make lsave node dirty. | |
925 | * @c: UBIFS file-system description object | |
926 | * @lnum: LEB number where lsave was written | |
927 | * @offs: offset where lsave was written | |
928 | * | |
929 | * This function is used by LPT garbage collection. LPT garbage collection is | |
930 | * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection | |
931 | * simply involves marking all the nodes in the LEB being garbage-collected as | |
932 | * dirty. The dirty nodes are written next commit, after which the LEB is free | |
933 | * to be reused. | |
934 | * | |
935 | * This function returns %0 on success and a negative error code on failure. | |
936 | */ | |
937 | static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs) | |
938 | { | |
939 | if (lnum != c->lsave_lnum || offs != c->lsave_offs) | |
940 | return 0; /* This lsave node is obsolete */ | |
941 | if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { | |
942 | c->lpt_drty_flgs |= LSAVE_DIRTY; | |
943 | ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); | |
944 | } | |
945 | return 0; | |
946 | } | |
947 | ||
948 | /** | |
949 | * make_node_dirty - make node dirty. | |
950 | * @c: UBIFS file-system description object | |
951 | * @node_type: LPT node type | |
952 | * @node_num: node number | |
953 | * @lnum: LEB number where node was written | |
954 | * @offs: offset where node was written | |
955 | * | |
956 | * This function is used by LPT garbage collection. LPT garbage collection is | |
957 | * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection | |
958 | * simply involves marking all the nodes in the LEB being garbage-collected as | |
959 | * dirty. The dirty nodes are written next commit, after which the LEB is free | |
960 | * to be reused. | |
961 | * | |
962 | * This function returns %0 on success and a negative error code on failure. | |
963 | */ | |
964 | static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num, | |
965 | int lnum, int offs) | |
966 | { | |
967 | switch (node_type) { | |
968 | case UBIFS_LPT_NNODE: | |
969 | return make_nnode_dirty(c, node_num, lnum, offs); | |
970 | case UBIFS_LPT_PNODE: | |
971 | return make_pnode_dirty(c, node_num, lnum, offs); | |
972 | case UBIFS_LPT_LTAB: | |
973 | return make_ltab_dirty(c, lnum, offs); | |
974 | case UBIFS_LPT_LSAVE: | |
975 | return make_lsave_dirty(c, lnum, offs); | |
976 | } | |
977 | return -EINVAL; | |
978 | } | |
979 | ||
980 | /** | |
981 | * get_lpt_node_len - return the length of a node based on its type. | |
982 | * @c: UBIFS file-system description object | |
983 | * @node_type: LPT node type | |
984 | */ | |
985 | static int get_lpt_node_len(struct ubifs_info *c, int node_type) | |
986 | { | |
987 | switch (node_type) { | |
988 | case UBIFS_LPT_NNODE: | |
989 | return c->nnode_sz; | |
990 | case UBIFS_LPT_PNODE: | |
991 | return c->pnode_sz; | |
992 | case UBIFS_LPT_LTAB: | |
993 | return c->ltab_sz; | |
994 | case UBIFS_LPT_LSAVE: | |
995 | return c->lsave_sz; | |
996 | } | |
997 | return 0; | |
998 | } | |
999 | ||
1000 | /** | |
1001 | * get_pad_len - return the length of padding in a buffer. | |
1002 | * @c: UBIFS file-system description object | |
1003 | * @buf: buffer | |
1004 | * @len: length of buffer | |
1005 | */ | |
1006 | static int get_pad_len(struct ubifs_info *c, uint8_t *buf, int len) | |
1007 | { | |
1008 | int offs, pad_len; | |
1009 | ||
1010 | if (c->min_io_size == 1) | |
1011 | return 0; | |
1012 | offs = c->leb_size - len; | |
1013 | pad_len = ALIGN(offs, c->min_io_size) - offs; | |
1014 | return pad_len; | |
1015 | } | |
1016 | ||
1017 | /** | |
1018 | * get_lpt_node_type - return type (and node number) of a node in a buffer. | |
1019 | * @c: UBIFS file-system description object | |
1020 | * @buf: buffer | |
1021 | * @node_num: node number is returned here | |
1022 | */ | |
1023 | static int get_lpt_node_type(struct ubifs_info *c, uint8_t *buf, int *node_num) | |
1024 | { | |
1025 | uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; | |
1026 | int pos = 0, node_type; | |
1027 | ||
1028 | node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS); | |
1029 | *node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits); | |
1030 | return node_type; | |
1031 | } | |
1032 | ||
1033 | /** | |
1034 | * is_a_node - determine if a buffer contains a node. | |
1035 | * @c: UBIFS file-system description object | |
1036 | * @buf: buffer | |
1037 | * @len: length of buffer | |
1038 | * | |
1039 | * This function returns %1 if the buffer contains a node or %0 if it does not. | |
1040 | */ | |
1041 | static int is_a_node(struct ubifs_info *c, uint8_t *buf, int len) | |
1042 | { | |
1043 | uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; | |
1044 | int pos = 0, node_type, node_len; | |
1045 | uint16_t crc, calc_crc; | |
1046 | ||
1047 | node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS); | |
1048 | if (node_type == UBIFS_LPT_NOT_A_NODE) | |
1049 | return 0; | |
1050 | node_len = get_lpt_node_len(c, node_type); | |
1051 | if (!node_len || node_len > len) | |
1052 | return 0; | |
1053 | pos = 0; | |
1054 | addr = buf; | |
1055 | crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS); | |
1056 | calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, | |
1057 | node_len - UBIFS_LPT_CRC_BYTES); | |
1058 | if (crc != calc_crc) | |
1059 | return 0; | |
1060 | return 1; | |
1061 | } | |
1062 | ||
1063 | ||
1064 | /** | |
1065 | * lpt_gc_lnum - garbage collect a LPT LEB. | |
1066 | * @c: UBIFS file-system description object | |
1067 | * @lnum: LEB number to garbage collect | |
1068 | * | |
1069 | * LPT garbage collection is used only for the "big" LPT model | |
1070 | * (c->big_lpt == 1). Garbage collection simply involves marking all the nodes | |
1071 | * in the LEB being garbage-collected as dirty. The dirty nodes are written | |
1072 | * next commit, after which the LEB is free to be reused. | |
1073 | * | |
1074 | * This function returns %0 on success and a negative error code on failure. | |
1075 | */ | |
1076 | static int lpt_gc_lnum(struct ubifs_info *c, int lnum) | |
1077 | { | |
1078 | int err, len = c->leb_size, node_type, node_num, node_len, offs; | |
1079 | void *buf = c->lpt_buf; | |
1080 | ||
1081 | dbg_lp("LEB %d", lnum); | |
1082 | err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size); | |
1083 | if (err) { | |
1084 | ubifs_err("cannot read LEB %d, error %d", lnum, err); | |
1085 | return err; | |
1086 | } | |
1087 | while (1) { | |
1088 | if (!is_a_node(c, buf, len)) { | |
1089 | int pad_len; | |
1090 | ||
1091 | pad_len = get_pad_len(c, buf, len); | |
1092 | if (pad_len) { | |
1093 | buf += pad_len; | |
1094 | len -= pad_len; | |
1095 | continue; | |
1096 | } | |
1097 | return 0; | |
1098 | } | |
1099 | node_type = get_lpt_node_type(c, buf, &node_num); | |
1100 | node_len = get_lpt_node_len(c, node_type); | |
1101 | offs = c->leb_size - len; | |
1102 | ubifs_assert(node_len != 0); | |
1103 | mutex_lock(&c->lp_mutex); | |
1104 | err = make_node_dirty(c, node_type, node_num, lnum, offs); | |
1105 | mutex_unlock(&c->lp_mutex); | |
1106 | if (err) | |
1107 | return err; | |
1108 | buf += node_len; | |
1109 | len -= node_len; | |
1110 | } | |
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | /** | |
1115 | * lpt_gc - LPT garbage collection. | |
1116 | * @c: UBIFS file-system description object | |
1117 | * | |
1118 | * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'. | |
1119 | * Returns %0 on success and a negative error code on failure. | |
1120 | */ | |
1121 | static int lpt_gc(struct ubifs_info *c) | |
1122 | { | |
1123 | int i, lnum = -1, dirty = 0; | |
1124 | ||
1125 | mutex_lock(&c->lp_mutex); | |
1126 | for (i = 0; i < c->lpt_lebs; i++) { | |
1127 | ubifs_assert(!c->ltab[i].tgc); | |
1128 | if (i + c->lpt_first == c->nhead_lnum || | |
1129 | c->ltab[i].free + c->ltab[i].dirty == c->leb_size) | |
1130 | continue; | |
1131 | if (c->ltab[i].dirty > dirty) { | |
1132 | dirty = c->ltab[i].dirty; | |
1133 | lnum = i + c->lpt_first; | |
1134 | } | |
1135 | } | |
1136 | mutex_unlock(&c->lp_mutex); | |
1137 | if (lnum == -1) | |
1138 | return -ENOSPC; | |
1139 | return lpt_gc_lnum(c, lnum); | |
1140 | } | |
1141 | ||
1142 | /** | |
1143 | * ubifs_lpt_start_commit - UBIFS commit starts. | |
1144 | * @c: the UBIFS file-system description object | |
1145 | * | |
1146 | * This function has to be called when UBIFS starts the commit operation. | |
1147 | * This function "freezes" all currently dirty LEB properties and does not | |
1148 | * change them anymore. Further changes are saved and tracked separately | |
1149 | * because they are not part of this commit. This function returns zero in case | |
1150 | * of success and a negative error code in case of failure. | |
1151 | */ | |
1152 | int ubifs_lpt_start_commit(struct ubifs_info *c) | |
1153 | { | |
1154 | int err, cnt; | |
1155 | ||
1156 | dbg_lp(""); | |
1157 | ||
1158 | mutex_lock(&c->lp_mutex); | |
1159 | err = dbg_check_ltab(c); | |
1160 | if (err) | |
1161 | goto out; | |
1162 | ||
1163 | if (c->check_lpt_free) { | |
1164 | /* | |
1165 | * We ensure there is enough free space in | |
1166 | * ubifs_lpt_post_commit() by marking nodes dirty. That | |
1167 | * information is lost when we unmount, so we also need | |
1168 | * to check free space once after mounting also. | |
1169 | */ | |
1170 | c->check_lpt_free = 0; | |
1171 | while (need_write_all(c)) { | |
1172 | mutex_unlock(&c->lp_mutex); | |
1173 | err = lpt_gc(c); | |
1174 | if (err) | |
1175 | return err; | |
1176 | mutex_lock(&c->lp_mutex); | |
1177 | } | |
1178 | } | |
1179 | ||
1180 | lpt_tgc_start(c); | |
1181 | ||
1182 | if (!c->dirty_pn_cnt) { | |
1183 | dbg_cmt("no cnodes to commit"); | |
1184 | err = 0; | |
1185 | goto out; | |
1186 | } | |
1187 | ||
1188 | if (!c->big_lpt && need_write_all(c)) { | |
1189 | /* If needed, write everything */ | |
1190 | err = make_tree_dirty(c); | |
1191 | if (err) | |
1192 | goto out; | |
1193 | lpt_tgc_start(c); | |
1194 | } | |
1195 | ||
1196 | if (c->big_lpt) | |
1197 | populate_lsave(c); | |
1198 | ||
1199 | cnt = get_cnodes_to_commit(c); | |
1200 | ubifs_assert(cnt != 0); | |
1201 | ||
1202 | err = layout_cnodes(c); | |
1203 | if (err) | |
1204 | goto out; | |
1205 | ||
1206 | /* Copy the LPT's own lprops for end commit to write */ | |
1207 | memcpy(c->ltab_cmt, c->ltab, | |
1208 | sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs); | |
1209 | c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY); | |
1210 | ||
1211 | out: | |
1212 | mutex_unlock(&c->lp_mutex); | |
1213 | return err; | |
1214 | } | |
1215 | ||
1216 | /** | |
1217 | * free_obsolete_cnodes - free obsolete cnodes for commit end. | |
1218 | * @c: UBIFS file-system description object | |
1219 | */ | |
1220 | static void free_obsolete_cnodes(struct ubifs_info *c) | |
1221 | { | |
1222 | struct ubifs_cnode *cnode, *cnext; | |
1223 | ||
1224 | cnext = c->lpt_cnext; | |
1225 | if (!cnext) | |
1226 | return; | |
1227 | do { | |
1228 | cnode = cnext; | |
1229 | cnext = cnode->cnext; | |
1230 | if (test_bit(OBSOLETE_CNODE, &cnode->flags)) | |
1231 | kfree(cnode); | |
1232 | else | |
1233 | cnode->cnext = NULL; | |
1234 | } while (cnext != c->lpt_cnext); | |
1235 | c->lpt_cnext = NULL; | |
1236 | } | |
1237 | ||
1238 | /** | |
1239 | * ubifs_lpt_end_commit - finish the commit operation. | |
1240 | * @c: the UBIFS file-system description object | |
1241 | * | |
1242 | * This function has to be called when the commit operation finishes. It | |
1243 | * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to | |
1244 | * the media. Returns zero in case of success and a negative error code in case | |
1245 | * of failure. | |
1246 | */ | |
1247 | int ubifs_lpt_end_commit(struct ubifs_info *c) | |
1248 | { | |
1249 | int err; | |
1250 | ||
1251 | dbg_lp(""); | |
1252 | ||
1253 | if (!c->lpt_cnext) | |
1254 | return 0; | |
1255 | ||
1256 | err = write_cnodes(c); | |
1257 | if (err) | |
1258 | return err; | |
1259 | ||
1260 | mutex_lock(&c->lp_mutex); | |
1261 | free_obsolete_cnodes(c); | |
1262 | mutex_unlock(&c->lp_mutex); | |
1263 | ||
1264 | return 0; | |
1265 | } | |
1266 | ||
1267 | /** | |
1268 | * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC. | |
1269 | * @c: UBIFS file-system description object | |
1270 | * | |
1271 | * LPT trivial GC is completed after a commit. Also LPT GC is done after a | |
1272 | * commit for the "big" LPT model. | |
1273 | */ | |
1274 | int ubifs_lpt_post_commit(struct ubifs_info *c) | |
1275 | { | |
1276 | int err; | |
1277 | ||
1278 | mutex_lock(&c->lp_mutex); | |
1279 | err = lpt_tgc_end(c); | |
1280 | if (err) | |
1281 | goto out; | |
1282 | if (c->big_lpt) | |
1283 | while (need_write_all(c)) { | |
1284 | mutex_unlock(&c->lp_mutex); | |
1285 | err = lpt_gc(c); | |
1286 | if (err) | |
1287 | return err; | |
1288 | mutex_lock(&c->lp_mutex); | |
1289 | } | |
1290 | out: | |
1291 | mutex_unlock(&c->lp_mutex); | |
1292 | return err; | |
1293 | } | |
1294 | ||
1295 | /** | |
1296 | * first_nnode - find the first nnode in memory. | |
1297 | * @c: UBIFS file-system description object | |
1298 | * @hght: height of tree where nnode found is returned here | |
1299 | * | |
1300 | * This function returns a pointer to the nnode found or %NULL if no nnode is | |
1301 | * found. This function is a helper to 'ubifs_lpt_free()'. | |
1302 | */ | |
1303 | static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght) | |
1304 | { | |
1305 | struct ubifs_nnode *nnode; | |
1306 | int h, i, found; | |
1307 | ||
1308 | nnode = c->nroot; | |
1309 | *hght = 0; | |
1310 | if (!nnode) | |
1311 | return NULL; | |
1312 | for (h = 1; h < c->lpt_hght; h++) { | |
1313 | found = 0; | |
1314 | for (i = 0; i < UBIFS_LPT_FANOUT; i++) { | |
1315 | if (nnode->nbranch[i].nnode) { | |
1316 | found = 1; | |
1317 | nnode = nnode->nbranch[i].nnode; | |
1318 | *hght = h; | |
1319 | break; | |
1320 | } | |
1321 | } | |
1322 | if (!found) | |
1323 | break; | |
1324 | } | |
1325 | return nnode; | |
1326 | } | |
1327 | ||
1328 | /** | |
1329 | * next_nnode - find the next nnode in memory. | |
1330 | * @c: UBIFS file-system description object | |
1331 | * @nnode: nnode from which to start. | |
1332 | * @hght: height of tree where nnode is, is passed and returned here | |
1333 | * | |
1334 | * This function returns a pointer to the nnode found or %NULL if no nnode is | |
1335 | * found. This function is a helper to 'ubifs_lpt_free()'. | |
1336 | */ | |
1337 | static struct ubifs_nnode *next_nnode(struct ubifs_info *c, | |
1338 | struct ubifs_nnode *nnode, int *hght) | |
1339 | { | |
1340 | struct ubifs_nnode *parent; | |
1341 | int iip, h, i, found; | |
1342 | ||
1343 | parent = nnode->parent; | |
1344 | if (!parent) | |
1345 | return NULL; | |
1346 | if (nnode->iip == UBIFS_LPT_FANOUT - 1) { | |
1347 | *hght -= 1; | |
1348 | return parent; | |
1349 | } | |
1350 | for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) { | |
1351 | nnode = parent->nbranch[iip].nnode; | |
1352 | if (nnode) | |
1353 | break; | |
1354 | } | |
1355 | if (!nnode) { | |
1356 | *hght -= 1; | |
1357 | return parent; | |
1358 | } | |
1359 | for (h = *hght + 1; h < c->lpt_hght; h++) { | |
1360 | found = 0; | |
1361 | for (i = 0; i < UBIFS_LPT_FANOUT; i++) { | |
1362 | if (nnode->nbranch[i].nnode) { | |
1363 | found = 1; | |
1364 | nnode = nnode->nbranch[i].nnode; | |
1365 | *hght = h; | |
1366 | break; | |
1367 | } | |
1368 | } | |
1369 | if (!found) | |
1370 | break; | |
1371 | } | |
1372 | return nnode; | |
1373 | } | |
1374 | ||
1375 | /** | |
1376 | * ubifs_lpt_free - free resources owned by the LPT. | |
1377 | * @c: UBIFS file-system description object | |
1378 | * @wr_only: free only resources used for writing | |
1379 | */ | |
1380 | void ubifs_lpt_free(struct ubifs_info *c, int wr_only) | |
1381 | { | |
1382 | struct ubifs_nnode *nnode; | |
1383 | int i, hght; | |
1384 | ||
1385 | /* Free write-only things first */ | |
1386 | ||
1387 | free_obsolete_cnodes(c); /* Leftover from a failed commit */ | |
1388 | ||
1389 | vfree(c->ltab_cmt); | |
1390 | c->ltab_cmt = NULL; | |
1391 | vfree(c->lpt_buf); | |
1392 | c->lpt_buf = NULL; | |
1393 | kfree(c->lsave); | |
1394 | c->lsave = NULL; | |
1395 | ||
1396 | if (wr_only) | |
1397 | return; | |
1398 | ||
1399 | /* Now free the rest */ | |
1400 | ||
1401 | nnode = first_nnode(c, &hght); | |
1402 | while (nnode) { | |
1403 | for (i = 0; i < UBIFS_LPT_FANOUT; i++) | |
1404 | kfree(nnode->nbranch[i].nnode); | |
1405 | nnode = next_nnode(c, nnode, &hght); | |
1406 | } | |
1407 | for (i = 0; i < LPROPS_HEAP_CNT; i++) | |
1408 | kfree(c->lpt_heap[i].arr); | |
1409 | kfree(c->dirty_idx.arr); | |
1410 | kfree(c->nroot); | |
1411 | vfree(c->ltab); | |
1412 | kfree(c->lpt_nod_buf); | |
1413 | } | |
1414 | ||
1415 | #ifdef CONFIG_UBIFS_FS_DEBUG | |
1416 | ||
1417 | /** | |
1418 | * dbg_is_all_ff - determine if a buffer contains only 0xff bytes. | |
1419 | * @buf: buffer | |
1420 | * @len: buffer length | |
1421 | */ | |
1422 | static int dbg_is_all_ff(uint8_t *buf, int len) | |
1423 | { | |
1424 | int i; | |
1425 | ||
1426 | for (i = 0; i < len; i++) | |
1427 | if (buf[i] != 0xff) | |
1428 | return 0; | |
1429 | return 1; | |
1430 | } | |
1431 | ||
1432 | /** | |
1433 | * dbg_is_nnode_dirty - determine if a nnode is dirty. | |
1434 | * @c: the UBIFS file-system description object | |
1435 | * @lnum: LEB number where nnode was written | |
1436 | * @offs: offset where nnode was written | |
1437 | */ | |
1438 | static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs) | |
1439 | { | |
1440 | struct ubifs_nnode *nnode; | |
1441 | int hght; | |
1442 | ||
1443 | /* Entire tree is in memory so first_nnode / next_nnode are ok */ | |
1444 | nnode = first_nnode(c, &hght); | |
1445 | for (; nnode; nnode = next_nnode(c, nnode, &hght)) { | |
1446 | struct ubifs_nbranch *branch; | |
1447 | ||
1448 | cond_resched(); | |
1449 | if (nnode->parent) { | |
1450 | branch = &nnode->parent->nbranch[nnode->iip]; | |
1451 | if (branch->lnum != lnum || branch->offs != offs) | |
1452 | continue; | |
1453 | if (test_bit(DIRTY_CNODE, &nnode->flags)) | |
1454 | return 1; | |
1455 | return 0; | |
1456 | } else { | |
1457 | if (c->lpt_lnum != lnum || c->lpt_offs != offs) | |
1458 | continue; | |
1459 | if (test_bit(DIRTY_CNODE, &nnode->flags)) | |
1460 | return 1; | |
1461 | return 0; | |
1462 | } | |
1463 | } | |
1464 | return 1; | |
1465 | } | |
1466 | ||
1467 | /** | |
1468 | * dbg_is_pnode_dirty - determine if a pnode is dirty. | |
1469 | * @c: the UBIFS file-system description object | |
1470 | * @lnum: LEB number where pnode was written | |
1471 | * @offs: offset where pnode was written | |
1472 | */ | |
1473 | static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs) | |
1474 | { | |
1475 | int i, cnt; | |
1476 | ||
1477 | cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); | |
1478 | for (i = 0; i < cnt; i++) { | |
1479 | struct ubifs_pnode *pnode; | |
1480 | struct ubifs_nbranch *branch; | |
1481 | ||
1482 | cond_resched(); | |
1483 | pnode = pnode_lookup(c, i); | |
1484 | if (IS_ERR(pnode)) | |
1485 | return PTR_ERR(pnode); | |
1486 | branch = &pnode->parent->nbranch[pnode->iip]; | |
1487 | if (branch->lnum != lnum || branch->offs != offs) | |
1488 | continue; | |
1489 | if (test_bit(DIRTY_CNODE, &pnode->flags)) | |
1490 | return 1; | |
1491 | return 0; | |
1492 | } | |
1493 | return 1; | |
1494 | } | |
1495 | ||
1496 | /** | |
1497 | * dbg_is_ltab_dirty - determine if a ltab node is dirty. | |
1498 | * @c: the UBIFS file-system description object | |
1499 | * @lnum: LEB number where ltab node was written | |
1500 | * @offs: offset where ltab node was written | |
1501 | */ | |
1502 | static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs) | |
1503 | { | |
1504 | if (lnum != c->ltab_lnum || offs != c->ltab_offs) | |
1505 | return 1; | |
1506 | return (c->lpt_drty_flgs & LTAB_DIRTY) != 0; | |
1507 | } | |
1508 | ||
1509 | /** | |
1510 | * dbg_is_lsave_dirty - determine if a lsave node is dirty. | |
1511 | * @c: the UBIFS file-system description object | |
1512 | * @lnum: LEB number where lsave node was written | |
1513 | * @offs: offset where lsave node was written | |
1514 | */ | |
1515 | static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs) | |
1516 | { | |
1517 | if (lnum != c->lsave_lnum || offs != c->lsave_offs) | |
1518 | return 1; | |
1519 | return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0; | |
1520 | } | |
1521 | ||
1522 | /** | |
1523 | * dbg_is_node_dirty - determine if a node is dirty. | |
1524 | * @c: the UBIFS file-system description object | |
1525 | * @node_type: node type | |
1526 | * @lnum: LEB number where node was written | |
1527 | * @offs: offset where node was written | |
1528 | */ | |
1529 | static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum, | |
1530 | int offs) | |
1531 | { | |
1532 | switch (node_type) { | |
1533 | case UBIFS_LPT_NNODE: | |
1534 | return dbg_is_nnode_dirty(c, lnum, offs); | |
1535 | case UBIFS_LPT_PNODE: | |
1536 | return dbg_is_pnode_dirty(c, lnum, offs); | |
1537 | case UBIFS_LPT_LTAB: | |
1538 | return dbg_is_ltab_dirty(c, lnum, offs); | |
1539 | case UBIFS_LPT_LSAVE: | |
1540 | return dbg_is_lsave_dirty(c, lnum, offs); | |
1541 | } | |
1542 | return 1; | |
1543 | } | |
1544 | ||
1545 | /** | |
1546 | * dbg_check_ltab_lnum - check the ltab for a LPT LEB number. | |
1547 | * @c: the UBIFS file-system description object | |
1548 | * @lnum: LEB number where node was written | |
1549 | * @offs: offset where node was written | |
1550 | * | |
1551 | * This function returns %0 on success and a negative error code on failure. | |
1552 | */ | |
1553 | static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum) | |
1554 | { | |
1555 | int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len; | |
1556 | int ret; | |
1557 | void *buf = c->dbg_buf; | |
1558 | ||
1559 | dbg_lp("LEB %d", lnum); | |
1560 | err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size); | |
1561 | if (err) { | |
1562 | dbg_msg("ubi_read failed, LEB %d, error %d", lnum, err); | |
1563 | return err; | |
1564 | } | |
1565 | while (1) { | |
1566 | if (!is_a_node(c, buf, len)) { | |
1567 | int i, pad_len; | |
1568 | ||
1569 | pad_len = get_pad_len(c, buf, len); | |
1570 | if (pad_len) { | |
1571 | buf += pad_len; | |
1572 | len -= pad_len; | |
1573 | dirty += pad_len; | |
1574 | continue; | |
1575 | } | |
1576 | if (!dbg_is_all_ff(buf, len)) { | |
1577 | dbg_msg("invalid empty space in LEB %d at %d", | |
1578 | lnum, c->leb_size - len); | |
1579 | err = -EINVAL; | |
1580 | } | |
1581 | i = lnum - c->lpt_first; | |
1582 | if (len != c->ltab[i].free) { | |
1583 | dbg_msg("invalid free space in LEB %d " | |
1584 | "(free %d, expected %d)", | |
1585 | lnum, len, c->ltab[i].free); | |
1586 | err = -EINVAL; | |
1587 | } | |
1588 | if (dirty != c->ltab[i].dirty) { | |
1589 | dbg_msg("invalid dirty space in LEB %d " | |
1590 | "(dirty %d, expected %d)", | |
1591 | lnum, dirty, c->ltab[i].dirty); | |
1592 | err = -EINVAL; | |
1593 | } | |
1594 | return err; | |
1595 | } | |
1596 | node_type = get_lpt_node_type(c, buf, &node_num); | |
1597 | node_len = get_lpt_node_len(c, node_type); | |
1598 | ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len); | |
1599 | if (ret == 1) | |
1600 | dirty += node_len; | |
1601 | buf += node_len; | |
1602 | len -= node_len; | |
1603 | } | |
1604 | } | |
1605 | ||
1606 | /** | |
1607 | * dbg_check_ltab - check the free and dirty space in the ltab. | |
1608 | * @c: the UBIFS file-system description object | |
1609 | * | |
1610 | * This function returns %0 on success and a negative error code on failure. | |
1611 | */ | |
1612 | int dbg_check_ltab(struct ubifs_info *c) | |
1613 | { | |
1614 | int lnum, err, i, cnt; | |
1615 | ||
1616 | if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS)) | |
1617 | return 0; | |
1618 | ||
1619 | /* Bring the entire tree into memory */ | |
1620 | cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); | |
1621 | for (i = 0; i < cnt; i++) { | |
1622 | struct ubifs_pnode *pnode; | |
1623 | ||
1624 | pnode = pnode_lookup(c, i); | |
1625 | if (IS_ERR(pnode)) | |
1626 | return PTR_ERR(pnode); | |
1627 | cond_resched(); | |
1628 | } | |
1629 | ||
1630 | /* Check nodes */ | |
1631 | err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0); | |
1632 | if (err) | |
1633 | return err; | |
1634 | ||
1635 | /* Check each LEB */ | |
1636 | for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { | |
1637 | err = dbg_check_ltab_lnum(c, lnum); | |
1638 | if (err) { | |
1639 | dbg_err("failed at LEB %d", lnum); | |
1640 | return err; | |
1641 | } | |
1642 | } | |
1643 | ||
1644 | dbg_lp("succeeded"); | |
1645 | return 0; | |
1646 | } | |
1647 | ||
1648 | #endif /* CONFIG_UBIFS_FS_DEBUG */ |