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1e51764a AB |
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: Artem Bityutskiy (Битюцкий Артём) | |
20 | * Adrian Hunter | |
21 | */ | |
22 | ||
23 | /* | |
24 | * This file is a part of UBIFS journal implementation and contains various | |
25 | * functions which manipulate the log. The log is a fixed area on the flash | |
26 | * which does not contain any data but refers to buds. The log is a part of the | |
27 | * journal. | |
28 | */ | |
29 | ||
30 | #include "ubifs.h" | |
31 | ||
32 | #ifdef CONFIG_UBIFS_FS_DEBUG | |
33 | static int dbg_check_bud_bytes(struct ubifs_info *c); | |
34 | #else | |
35 | #define dbg_check_bud_bytes(c) 0 | |
36 | #endif | |
37 | ||
38 | /** | |
39 | * ubifs_search_bud - search bud LEB. | |
40 | * @c: UBIFS file-system description object | |
41 | * @lnum: logical eraseblock number to search | |
42 | * | |
43 | * This function searches bud LEB @lnum. Returns bud description object in case | |
44 | * of success and %NULL if there is no bud with this LEB number. | |
45 | */ | |
46 | struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum) | |
47 | { | |
48 | struct rb_node *p; | |
49 | struct ubifs_bud *bud; | |
50 | ||
51 | spin_lock(&c->buds_lock); | |
52 | p = c->buds.rb_node; | |
53 | while (p) { | |
54 | bud = rb_entry(p, struct ubifs_bud, rb); | |
55 | if (lnum < bud->lnum) | |
56 | p = p->rb_left; | |
57 | else if (lnum > bud->lnum) | |
58 | p = p->rb_right; | |
59 | else { | |
60 | spin_unlock(&c->buds_lock); | |
61 | return bud; | |
62 | } | |
63 | } | |
64 | spin_unlock(&c->buds_lock); | |
65 | return NULL; | |
66 | } | |
67 | ||
68 | /** | |
69 | * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one. | |
70 | * @c: UBIFS file-system description object | |
71 | * @lnum: logical eraseblock number to search | |
72 | * | |
73 | * This functions returns the wbuf for @lnum or %NULL if there is not one. | |
74 | */ | |
75 | struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum) | |
76 | { | |
77 | struct rb_node *p; | |
78 | struct ubifs_bud *bud; | |
79 | int jhead; | |
80 | ||
81 | if (!c->jheads) | |
82 | return NULL; | |
83 | ||
84 | spin_lock(&c->buds_lock); | |
85 | p = c->buds.rb_node; | |
86 | while (p) { | |
87 | bud = rb_entry(p, struct ubifs_bud, rb); | |
88 | if (lnum < bud->lnum) | |
89 | p = p->rb_left; | |
90 | else if (lnum > bud->lnum) | |
91 | p = p->rb_right; | |
92 | else { | |
93 | jhead = bud->jhead; | |
94 | spin_unlock(&c->buds_lock); | |
95 | return &c->jheads[jhead].wbuf; | |
96 | } | |
97 | } | |
98 | spin_unlock(&c->buds_lock); | |
99 | return NULL; | |
100 | } | |
101 | ||
102 | /** | |
103 | * next_log_lnum - switch to the next log LEB. | |
104 | * @c: UBIFS file-system description object | |
105 | * @lnum: current log LEB | |
106 | */ | |
107 | static inline int next_log_lnum(const struct ubifs_info *c, int lnum) | |
108 | { | |
109 | lnum += 1; | |
110 | if (lnum > c->log_last) | |
111 | lnum = UBIFS_LOG_LNUM; | |
112 | ||
113 | return lnum; | |
114 | } | |
115 | ||
116 | /** | |
117 | * empty_log_bytes - calculate amount of empty space in the log. | |
118 | * @c: UBIFS file-system description object | |
119 | */ | |
120 | static inline long long empty_log_bytes(const struct ubifs_info *c) | |
121 | { | |
122 | long long h, t; | |
123 | ||
124 | h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs; | |
125 | t = (long long)c->ltail_lnum * c->leb_size; | |
126 | ||
127 | if (h >= t) | |
128 | return c->log_bytes - h + t; | |
129 | else | |
130 | return t - h; | |
131 | } | |
132 | ||
133 | /** | |
134 | * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list. | |
135 | * @c: UBIFS file-system description object | |
136 | * @bud: the bud to add | |
137 | */ | |
138 | void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud) | |
139 | { | |
140 | struct rb_node **p, *parent = NULL; | |
141 | struct ubifs_bud *b; | |
142 | struct ubifs_jhead *jhead; | |
143 | ||
144 | spin_lock(&c->buds_lock); | |
145 | p = &c->buds.rb_node; | |
146 | while (*p) { | |
147 | parent = *p; | |
148 | b = rb_entry(parent, struct ubifs_bud, rb); | |
149 | ubifs_assert(bud->lnum != b->lnum); | |
150 | if (bud->lnum < b->lnum) | |
151 | p = &(*p)->rb_left; | |
152 | else | |
153 | p = &(*p)->rb_right; | |
154 | } | |
155 | ||
156 | rb_link_node(&bud->rb, parent, p); | |
157 | rb_insert_color(&bud->rb, &c->buds); | |
158 | if (c->jheads) { | |
159 | jhead = &c->jheads[bud->jhead]; | |
160 | list_add_tail(&bud->list, &jhead->buds_list); | |
161 | } else | |
2ef13294 | 162 | ubifs_assert(c->replaying && c->ro_mount); |
1e51764a AB |
163 | |
164 | /* | |
165 | * Note, although this is a new bud, we anyway account this space now, | |
166 | * before any data has been written to it, because this is about to | |
167 | * guarantee fixed mount time, and this bud will anyway be read and | |
168 | * scanned. | |
169 | */ | |
170 | c->bud_bytes += c->leb_size - bud->start; | |
171 | ||
77a7ae58 AB |
172 | dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum, |
173 | bud->start, dbg_jhead(bud->jhead), c->bud_bytes); | |
1e51764a AB |
174 | spin_unlock(&c->buds_lock); |
175 | } | |
176 | ||
1e51764a AB |
177 | /** |
178 | * ubifs_add_bud_to_log - add a new bud to the log. | |
179 | * @c: UBIFS file-system description object | |
180 | * @jhead: journal head the bud belongs to | |
181 | * @lnum: LEB number of the bud | |
182 | * @offs: starting offset of the bud | |
183 | * | |
184 | * This function writes reference node for the new bud LEB @lnum it to the log, | |
185 | * and adds it to the buds tress. It also makes sure that log size does not | |
186 | * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success, | |
187 | * %-EAGAIN if commit is required, and a negative error codes in case of | |
188 | * failure. | |
189 | */ | |
190 | int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs) | |
191 | { | |
192 | int err; | |
193 | struct ubifs_bud *bud; | |
194 | struct ubifs_ref_node *ref; | |
195 | ||
196 | bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS); | |
197 | if (!bud) | |
198 | return -ENOMEM; | |
199 | ref = kzalloc(c->ref_node_alsz, GFP_NOFS); | |
200 | if (!ref) { | |
201 | kfree(bud); | |
202 | return -ENOMEM; | |
203 | } | |
204 | ||
205 | mutex_lock(&c->log_mutex); | |
2ef13294 | 206 | ubifs_assert(!c->ro_media && !c->ro_mount); |
2680d722 | 207 | if (c->ro_error) { |
1e51764a AB |
208 | err = -EROFS; |
209 | goto out_unlock; | |
210 | } | |
211 | ||
212 | /* Make sure we have enough space in the log */ | |
213 | if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) { | |
214 | dbg_log("not enough log space - %lld, required %d", | |
215 | empty_log_bytes(c), c->min_log_bytes); | |
216 | ubifs_commit_required(c); | |
217 | err = -EAGAIN; | |
218 | goto out_unlock; | |
219 | } | |
220 | ||
221 | /* | |
7d4e9ccb | 222 | * Make sure the amount of space in buds will not exceed the |
1e51764a AB |
223 | * 'c->max_bud_bytes' limit, because we want to guarantee mount time |
224 | * limits. | |
225 | * | |
226 | * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes | |
227 | * because we are holding @c->log_mutex. All @c->bud_bytes take place | |
228 | * when both @c->log_mutex and @c->bud_bytes are locked. | |
229 | */ | |
230 | if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) { | |
231 | dbg_log("bud bytes %lld (%lld max), require commit", | |
232 | c->bud_bytes, c->max_bud_bytes); | |
233 | ubifs_commit_required(c); | |
234 | err = -EAGAIN; | |
235 | goto out_unlock; | |
236 | } | |
237 | ||
238 | /* | |
239 | * If the journal is full enough - start background commit. Note, it is | |
240 | * OK to read 'c->cmt_state' without spinlock because integer reads | |
241 | * are atomic in the kernel. | |
242 | */ | |
243 | if (c->bud_bytes >= c->bg_bud_bytes && | |
244 | c->cmt_state == COMMIT_RESTING) { | |
245 | dbg_log("bud bytes %lld (%lld max), initiate BG commit", | |
246 | c->bud_bytes, c->max_bud_bytes); | |
247 | ubifs_request_bg_commit(c); | |
248 | } | |
249 | ||
250 | bud->lnum = lnum; | |
251 | bud->start = offs; | |
252 | bud->jhead = jhead; | |
253 | ||
254 | ref->ch.node_type = UBIFS_REF_NODE; | |
255 | ref->lnum = cpu_to_le32(bud->lnum); | |
256 | ref->offs = cpu_to_le32(bud->start); | |
257 | ref->jhead = cpu_to_le32(jhead); | |
258 | ||
259 | if (c->lhead_offs > c->leb_size - c->ref_node_alsz) { | |
260 | c->lhead_lnum = next_log_lnum(c, c->lhead_lnum); | |
261 | c->lhead_offs = 0; | |
262 | } | |
263 | ||
264 | if (c->lhead_offs == 0) { | |
265 | /* Must ensure next log LEB has been unmapped */ | |
266 | err = ubifs_leb_unmap(c, c->lhead_lnum); | |
267 | if (err) | |
268 | goto out_unlock; | |
269 | } | |
270 | ||
271 | if (bud->start == 0) { | |
272 | /* | |
273 | * Before writing the LEB reference which refers an empty LEB | |
274 | * to the log, we have to make sure it is mapped, because | |
275 | * otherwise we'd risk to refer an LEB with garbage in case of | |
276 | * an unclean reboot, because the target LEB might have been | |
277 | * unmapped, but not yet physically erased. | |
278 | */ | |
279 | err = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM); | |
280 | if (err) | |
281 | goto out_unlock; | |
282 | } | |
283 | ||
284 | dbg_log("write ref LEB %d:%d", | |
285 | c->lhead_lnum, c->lhead_offs); | |
286 | err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum, | |
287 | c->lhead_offs, UBI_SHORTTERM); | |
288 | if (err) | |
289 | goto out_unlock; | |
290 | ||
291 | c->lhead_offs += c->ref_node_alsz; | |
292 | ||
293 | ubifs_add_bud(c, bud); | |
294 | ||
295 | mutex_unlock(&c->log_mutex); | |
296 | kfree(ref); | |
297 | return 0; | |
298 | ||
299 | out_unlock: | |
2fb42b11 AH |
300 | if (err != -EAGAIN) |
301 | ubifs_ro_mode(c, err); | |
1e51764a AB |
302 | mutex_unlock(&c->log_mutex); |
303 | kfree(ref); | |
304 | kfree(bud); | |
305 | return err; | |
306 | } | |
307 | ||
308 | /** | |
309 | * remove_buds - remove used buds. | |
310 | * @c: UBIFS file-system description object | |
311 | * | |
312 | * This function removes use buds from the buds tree. It does not remove the | |
313 | * buds which are pointed to by journal heads. | |
314 | */ | |
315 | static void remove_buds(struct ubifs_info *c) | |
316 | { | |
317 | struct rb_node *p; | |
318 | ||
319 | ubifs_assert(list_empty(&c->old_buds)); | |
320 | c->cmt_bud_bytes = 0; | |
321 | spin_lock(&c->buds_lock); | |
322 | p = rb_first(&c->buds); | |
323 | while (p) { | |
324 | struct rb_node *p1 = p; | |
325 | struct ubifs_bud *bud; | |
326 | struct ubifs_wbuf *wbuf; | |
327 | ||
328 | p = rb_next(p); | |
329 | bud = rb_entry(p1, struct ubifs_bud, rb); | |
330 | wbuf = &c->jheads[bud->jhead].wbuf; | |
331 | ||
332 | if (wbuf->lnum == bud->lnum) { | |
333 | /* | |
334 | * Do not remove buds which are pointed to by journal | |
335 | * heads (non-closed buds). | |
336 | */ | |
337 | c->cmt_bud_bytes += wbuf->offs - bud->start; | |
77a7ae58 | 338 | dbg_log("preserve %d:%d, jhead %s, bud bytes %d, " |
1e51764a | 339 | "cmt_bud_bytes %lld", bud->lnum, bud->start, |
77a7ae58 | 340 | dbg_jhead(bud->jhead), wbuf->offs - bud->start, |
1e51764a AB |
341 | c->cmt_bud_bytes); |
342 | bud->start = wbuf->offs; | |
343 | } else { | |
344 | c->cmt_bud_bytes += c->leb_size - bud->start; | |
77a7ae58 | 345 | dbg_log("remove %d:%d, jhead %s, bud bytes %d, " |
1e51764a | 346 | "cmt_bud_bytes %lld", bud->lnum, bud->start, |
77a7ae58 | 347 | dbg_jhead(bud->jhead), c->leb_size - bud->start, |
1e51764a AB |
348 | c->cmt_bud_bytes); |
349 | rb_erase(p1, &c->buds); | |
1e51764a AB |
350 | /* |
351 | * If the commit does not finish, the recovery will need | |
352 | * to replay the journal, in which case the old buds | |
353 | * must be unchanged. Do not release them until post | |
354 | * commit i.e. do not allow them to be garbage | |
355 | * collected. | |
356 | */ | |
ec32816f | 357 | list_move(&bud->list, &c->old_buds); |
1e51764a AB |
358 | } |
359 | } | |
360 | spin_unlock(&c->buds_lock); | |
361 | } | |
362 | ||
363 | /** | |
364 | * ubifs_log_start_commit - start commit. | |
365 | * @c: UBIFS file-system description object | |
366 | * @ltail_lnum: return new log tail LEB number | |
367 | * | |
368 | * The commit operation starts with writing "commit start" node to the log and | |
369 | * reference nodes for all journal heads which will define new journal after | |
370 | * the commit has been finished. The commit start and reference nodes are | |
371 | * written in one go to the nearest empty log LEB (hence, when commit is | |
372 | * finished UBIFS may safely unmap all the previous log LEBs). This function | |
373 | * returns zero in case of success and a negative error code in case of | |
374 | * failure. | |
375 | */ | |
376 | int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum) | |
377 | { | |
378 | void *buf; | |
379 | struct ubifs_cs_node *cs; | |
380 | struct ubifs_ref_node *ref; | |
381 | int err, i, max_len, len; | |
382 | ||
383 | err = dbg_check_bud_bytes(c); | |
384 | if (err) | |
385 | return err; | |
386 | ||
387 | max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ; | |
388 | max_len = ALIGN(max_len, c->min_io_size); | |
389 | buf = cs = kmalloc(max_len, GFP_NOFS); | |
390 | if (!buf) | |
391 | return -ENOMEM; | |
392 | ||
393 | cs->ch.node_type = UBIFS_CS_NODE; | |
014eb04b | 394 | cs->cmt_no = cpu_to_le64(c->cmt_no); |
1e51764a AB |
395 | ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0); |
396 | ||
397 | /* | |
398 | * Note, we do not lock 'c->log_mutex' because this is the commit start | |
399 | * phase and we are exclusively using the log. And we do not lock | |
400 | * write-buffer because nobody can write to the file-system at this | |
401 | * phase. | |
402 | */ | |
403 | ||
404 | len = UBIFS_CS_NODE_SZ; | |
405 | for (i = 0; i < c->jhead_cnt; i++) { | |
406 | int lnum = c->jheads[i].wbuf.lnum; | |
407 | int offs = c->jheads[i].wbuf.offs; | |
408 | ||
409 | if (lnum == -1 || offs == c->leb_size) | |
410 | continue; | |
411 | ||
77a7ae58 AB |
412 | dbg_log("add ref to LEB %d:%d for jhead %s", |
413 | lnum, offs, dbg_jhead(i)); | |
1e51764a AB |
414 | ref = buf + len; |
415 | ref->ch.node_type = UBIFS_REF_NODE; | |
416 | ref->lnum = cpu_to_le32(lnum); | |
417 | ref->offs = cpu_to_le32(offs); | |
418 | ref->jhead = cpu_to_le32(i); | |
419 | ||
420 | ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0); | |
421 | len += UBIFS_REF_NODE_SZ; | |
422 | } | |
423 | ||
424 | ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len); | |
425 | ||
426 | /* Switch to the next log LEB */ | |
427 | if (c->lhead_offs) { | |
428 | c->lhead_lnum = next_log_lnum(c, c->lhead_lnum); | |
429 | c->lhead_offs = 0; | |
430 | } | |
431 | ||
432 | if (c->lhead_offs == 0) { | |
433 | /* Must ensure next LEB has been unmapped */ | |
434 | err = ubifs_leb_unmap(c, c->lhead_lnum); | |
435 | if (err) | |
436 | goto out; | |
437 | } | |
438 | ||
439 | len = ALIGN(len, c->min_io_size); | |
440 | dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len); | |
441 | err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM); | |
442 | if (err) | |
443 | goto out; | |
444 | ||
445 | *ltail_lnum = c->lhead_lnum; | |
446 | ||
447 | c->lhead_offs += len; | |
448 | if (c->lhead_offs == c->leb_size) { | |
449 | c->lhead_lnum = next_log_lnum(c, c->lhead_lnum); | |
450 | c->lhead_offs = 0; | |
451 | } | |
452 | ||
453 | remove_buds(c); | |
454 | ||
455 | /* | |
456 | * We have started the commit and now users may use the rest of the log | |
457 | * for new writes. | |
458 | */ | |
459 | c->min_log_bytes = 0; | |
460 | ||
461 | out: | |
462 | kfree(buf); | |
463 | return err; | |
464 | } | |
465 | ||
466 | /** | |
467 | * ubifs_log_end_commit - end commit. | |
468 | * @c: UBIFS file-system description object | |
469 | * @ltail_lnum: new log tail LEB number | |
470 | * | |
471 | * This function is called on when the commit operation was finished. It | |
472 | * moves log tail to new position and unmaps LEBs which contain obsolete data. | |
473 | * Returns zero in case of success and a negative error code in case of | |
474 | * failure. | |
475 | */ | |
476 | int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum) | |
477 | { | |
478 | int err; | |
479 | ||
480 | /* | |
481 | * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS | |
482 | * writes during commit. Its only short "commit" start phase when | |
483 | * writers are blocked. | |
484 | */ | |
485 | mutex_lock(&c->log_mutex); | |
486 | ||
487 | dbg_log("old tail was LEB %d:0, new tail is LEB %d:0", | |
488 | c->ltail_lnum, ltail_lnum); | |
489 | ||
490 | c->ltail_lnum = ltail_lnum; | |
491 | /* | |
492 | * The commit is finished and from now on it must be guaranteed that | |
493 | * there is always enough space for the next commit. | |
494 | */ | |
495 | c->min_log_bytes = c->leb_size; | |
496 | ||
497 | spin_lock(&c->buds_lock); | |
498 | c->bud_bytes -= c->cmt_bud_bytes; | |
499 | spin_unlock(&c->buds_lock); | |
500 | ||
501 | err = dbg_check_bud_bytes(c); | |
502 | ||
503 | mutex_unlock(&c->log_mutex); | |
504 | return err; | |
505 | } | |
506 | ||
507 | /** | |
508 | * ubifs_log_post_commit - things to do after commit is completed. | |
509 | * @c: UBIFS file-system description object | |
510 | * @old_ltail_lnum: old log tail LEB number | |
511 | * | |
512 | * Release buds only after commit is completed, because they must be unchanged | |
513 | * if recovery is needed. | |
514 | * | |
515 | * Unmap log LEBs only after commit is completed, because they may be needed for | |
516 | * recovery. | |
517 | * | |
518 | * This function returns %0 on success and a negative error code on failure. | |
519 | */ | |
520 | int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum) | |
521 | { | |
522 | int lnum, err = 0; | |
523 | ||
524 | while (!list_empty(&c->old_buds)) { | |
525 | struct ubifs_bud *bud; | |
526 | ||
527 | bud = list_entry(c->old_buds.next, struct ubifs_bud, list); | |
528 | err = ubifs_return_leb(c, bud->lnum); | |
529 | if (err) | |
530 | return err; | |
531 | list_del(&bud->list); | |
532 | kfree(bud); | |
533 | } | |
534 | mutex_lock(&c->log_mutex); | |
535 | for (lnum = old_ltail_lnum; lnum != c->ltail_lnum; | |
536 | lnum = next_log_lnum(c, lnum)) { | |
537 | dbg_log("unmap log LEB %d", lnum); | |
538 | err = ubifs_leb_unmap(c, lnum); | |
539 | if (err) | |
540 | goto out; | |
541 | } | |
542 | out: | |
543 | mutex_unlock(&c->log_mutex); | |
544 | return err; | |
545 | } | |
546 | ||
547 | /** | |
548 | * struct done_ref - references that have been done. | |
549 | * @rb: rb-tree node | |
550 | * @lnum: LEB number | |
551 | */ | |
552 | struct done_ref { | |
553 | struct rb_node rb; | |
554 | int lnum; | |
555 | }; | |
556 | ||
557 | /** | |
558 | * done_already - determine if a reference has been done already. | |
559 | * @done_tree: rb-tree to store references that have been done | |
560 | * @lnum: LEB number of reference | |
561 | * | |
562 | * This function returns %1 if the reference has been done, %0 if not, otherwise | |
563 | * a negative error code is returned. | |
564 | */ | |
565 | static int done_already(struct rb_root *done_tree, int lnum) | |
566 | { | |
567 | struct rb_node **p = &done_tree->rb_node, *parent = NULL; | |
568 | struct done_ref *dr; | |
569 | ||
570 | while (*p) { | |
571 | parent = *p; | |
572 | dr = rb_entry(parent, struct done_ref, rb); | |
573 | if (lnum < dr->lnum) | |
574 | p = &(*p)->rb_left; | |
575 | else if (lnum > dr->lnum) | |
576 | p = &(*p)->rb_right; | |
577 | else | |
578 | return 1; | |
579 | } | |
580 | ||
581 | dr = kzalloc(sizeof(struct done_ref), GFP_NOFS); | |
582 | if (!dr) | |
583 | return -ENOMEM; | |
584 | ||
585 | dr->lnum = lnum; | |
586 | ||
587 | rb_link_node(&dr->rb, parent, p); | |
588 | rb_insert_color(&dr->rb, done_tree); | |
589 | ||
590 | return 0; | |
591 | } | |
592 | ||
593 | /** | |
594 | * destroy_done_tree - destroy the done tree. | |
595 | * @done_tree: done tree to destroy | |
596 | */ | |
597 | static void destroy_done_tree(struct rb_root *done_tree) | |
598 | { | |
599 | struct rb_node *this = done_tree->rb_node; | |
600 | struct done_ref *dr; | |
601 | ||
602 | while (this) { | |
603 | if (this->rb_left) { | |
604 | this = this->rb_left; | |
605 | continue; | |
606 | } else if (this->rb_right) { | |
607 | this = this->rb_right; | |
608 | continue; | |
609 | } | |
610 | dr = rb_entry(this, struct done_ref, rb); | |
611 | this = rb_parent(this); | |
612 | if (this) { | |
613 | if (this->rb_left == &dr->rb) | |
614 | this->rb_left = NULL; | |
615 | else | |
616 | this->rb_right = NULL; | |
617 | } | |
618 | kfree(dr); | |
619 | } | |
620 | } | |
621 | ||
622 | /** | |
623 | * add_node - add a node to the consolidated log. | |
624 | * @c: UBIFS file-system description object | |
625 | * @buf: buffer to which to add | |
626 | * @lnum: LEB number to which to write is passed and returned here | |
627 | * @offs: offset to where to write is passed and returned here | |
628 | * @node: node to add | |
629 | * | |
630 | * This function returns %0 on success and a negative error code on failure. | |
631 | */ | |
632 | static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs, | |
633 | void *node) | |
634 | { | |
635 | struct ubifs_ch *ch = node; | |
636 | int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs; | |
637 | ||
638 | if (len > remains) { | |
639 | int sz = ALIGN(*offs, c->min_io_size), err; | |
640 | ||
641 | ubifs_pad(c, buf + *offs, sz - *offs); | |
642 | err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM); | |
643 | if (err) | |
644 | return err; | |
645 | *lnum = next_log_lnum(c, *lnum); | |
646 | *offs = 0; | |
647 | } | |
648 | memcpy(buf + *offs, node, len); | |
649 | *offs += ALIGN(len, 8); | |
650 | return 0; | |
651 | } | |
652 | ||
653 | /** | |
654 | * ubifs_consolidate_log - consolidate the log. | |
655 | * @c: UBIFS file-system description object | |
656 | * | |
657 | * Repeated failed commits could cause the log to be full, but at least 1 LEB is | |
658 | * needed for commit. This function rewrites the reference nodes in the log | |
659 | * omitting duplicates, and failed CS nodes, and leaving no gaps. | |
660 | * | |
661 | * This function returns %0 on success and a negative error code on failure. | |
662 | */ | |
663 | int ubifs_consolidate_log(struct ubifs_info *c) | |
664 | { | |
665 | struct ubifs_scan_leb *sleb; | |
666 | struct ubifs_scan_node *snod; | |
667 | struct rb_root done_tree = RB_ROOT; | |
668 | int lnum, err, first = 1, write_lnum, offs = 0; | |
669 | void *buf; | |
670 | ||
671 | dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum, | |
672 | c->lhead_lnum); | |
673 | buf = vmalloc(c->leb_size); | |
674 | if (!buf) | |
675 | return -ENOMEM; | |
676 | lnum = c->ltail_lnum; | |
677 | write_lnum = lnum; | |
678 | while (1) { | |
348709ba | 679 | sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0); |
1e51764a AB |
680 | if (IS_ERR(sleb)) { |
681 | err = PTR_ERR(sleb); | |
682 | goto out_free; | |
683 | } | |
684 | list_for_each_entry(snod, &sleb->nodes, list) { | |
685 | switch (snod->type) { | |
686 | case UBIFS_REF_NODE: { | |
687 | struct ubifs_ref_node *ref = snod->node; | |
688 | int ref_lnum = le32_to_cpu(ref->lnum); | |
689 | ||
690 | err = done_already(&done_tree, ref_lnum); | |
691 | if (err < 0) | |
692 | goto out_scan; | |
693 | if (err != 1) { | |
694 | err = add_node(c, buf, &write_lnum, | |
695 | &offs, snod->node); | |
696 | if (err) | |
697 | goto out_scan; | |
698 | } | |
699 | break; | |
700 | } | |
701 | case UBIFS_CS_NODE: | |
702 | if (!first) | |
703 | break; | |
704 | err = add_node(c, buf, &write_lnum, &offs, | |
705 | snod->node); | |
706 | if (err) | |
707 | goto out_scan; | |
708 | first = 0; | |
709 | break; | |
710 | } | |
711 | } | |
712 | ubifs_scan_destroy(sleb); | |
713 | if (lnum == c->lhead_lnum) | |
714 | break; | |
715 | lnum = next_log_lnum(c, lnum); | |
716 | } | |
717 | if (offs) { | |
718 | int sz = ALIGN(offs, c->min_io_size); | |
719 | ||
720 | ubifs_pad(c, buf + offs, sz - offs); | |
721 | err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM); | |
722 | if (err) | |
723 | goto out_free; | |
724 | offs = ALIGN(offs, c->min_io_size); | |
725 | } | |
726 | destroy_done_tree(&done_tree); | |
727 | vfree(buf); | |
728 | if (write_lnum == c->lhead_lnum) { | |
729 | ubifs_err("log is too full"); | |
730 | return -EINVAL; | |
731 | } | |
732 | /* Unmap remaining LEBs */ | |
733 | lnum = write_lnum; | |
734 | do { | |
735 | lnum = next_log_lnum(c, lnum); | |
736 | err = ubifs_leb_unmap(c, lnum); | |
737 | if (err) | |
738 | return err; | |
739 | } while (lnum != c->lhead_lnum); | |
740 | c->lhead_lnum = write_lnum; | |
741 | c->lhead_offs = offs; | |
742 | dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs); | |
743 | return 0; | |
744 | ||
745 | out_scan: | |
746 | ubifs_scan_destroy(sleb); | |
747 | out_free: | |
748 | destroy_done_tree(&done_tree); | |
749 | vfree(buf); | |
750 | return err; | |
751 | } | |
752 | ||
753 | #ifdef CONFIG_UBIFS_FS_DEBUG | |
754 | ||
755 | /** | |
756 | * dbg_check_bud_bytes - make sure bud bytes calculation are all right. | |
757 | * @c: UBIFS file-system description object | |
758 | * | |
759 | * This function makes sure the amount of flash space used by closed buds | |
760 | * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in | |
761 | * case of failure. | |
762 | */ | |
763 | static int dbg_check_bud_bytes(struct ubifs_info *c) | |
764 | { | |
765 | int i, err = 0; | |
766 | struct ubifs_bud *bud; | |
767 | long long bud_bytes = 0; | |
768 | ||
769 | if (!(ubifs_chk_flags & UBIFS_CHK_GEN)) | |
770 | return 0; | |
771 | ||
772 | spin_lock(&c->buds_lock); | |
773 | for (i = 0; i < c->jhead_cnt; i++) | |
774 | list_for_each_entry(bud, &c->jheads[i].buds_list, list) | |
775 | bud_bytes += c->leb_size - bud->start; | |
776 | ||
777 | if (c->bud_bytes != bud_bytes) { | |
778 | ubifs_err("bad bud_bytes %lld, calculated %lld", | |
779 | c->bud_bytes, bud_bytes); | |
780 | err = -EINVAL; | |
781 | } | |
782 | spin_unlock(&c->buds_lock); | |
783 | ||
784 | return err; | |
785 | } | |
786 | ||
787 | #endif /* CONFIG_UBIFS_FS_DEBUG */ |