blob: affea9494ae23551fd34109f009ad6f74cdec276 [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: 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
33static 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 */
46struct 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 */
75struct 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/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300103 * empty_log_bytes - calculate amount of empty space in the log.
104 * @c: UBIFS file-system description object
105 */
106static inline long long empty_log_bytes(const struct ubifs_info *c)
107{
108 long long h, t;
109
110 h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
111 t = (long long)c->ltail_lnum * c->leb_size;
112
113 if (h >= t)
114 return c->log_bytes - h + t;
115 else
116 return t - h;
117}
118
119/**
120 * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
121 * @c: UBIFS file-system description object
122 * @bud: the bud to add
123 */
124void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
125{
126 struct rb_node **p, *parent = NULL;
127 struct ubifs_bud *b;
128 struct ubifs_jhead *jhead;
129
130 spin_lock(&c->buds_lock);
131 p = &c->buds.rb_node;
132 while (*p) {
133 parent = *p;
134 b = rb_entry(parent, struct ubifs_bud, rb);
135 ubifs_assert(bud->lnum != b->lnum);
136 if (bud->lnum < b->lnum)
137 p = &(*p)->rb_left;
138 else
139 p = &(*p)->rb_right;
140 }
141
142 rb_link_node(&bud->rb, parent, p);
143 rb_insert_color(&bud->rb, &c->buds);
144 if (c->jheads) {
145 jhead = &c->jheads[bud->jhead];
146 list_add_tail(&bud->list, &jhead->buds_list);
147 } else
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300148 ubifs_assert(c->replaying && c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300149
150 /*
151 * Note, although this is a new bud, we anyway account this space now,
152 * before any data has been written to it, because this is about to
153 * guarantee fixed mount time, and this bud will anyway be read and
154 * scanned.
155 */
156 c->bud_bytes += c->leb_size - bud->start;
157
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300158 dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
159 bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300160 spin_unlock(&c->buds_lock);
161}
162
163/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300164 * ubifs_add_bud_to_log - add a new bud to the log.
165 * @c: UBIFS file-system description object
166 * @jhead: journal head the bud belongs to
167 * @lnum: LEB number of the bud
168 * @offs: starting offset of the bud
169 *
170 * This function writes reference node for the new bud LEB @lnum it to the log,
171 * and adds it to the buds tress. It also makes sure that log size does not
172 * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
173 * %-EAGAIN if commit is required, and a negative error codes in case of
174 * failure.
175 */
176int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
177{
178 int err;
179 struct ubifs_bud *bud;
180 struct ubifs_ref_node *ref;
181
182 bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
183 if (!bud)
184 return -ENOMEM;
185 ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
186 if (!ref) {
187 kfree(bud);
188 return -ENOMEM;
189 }
190
191 mutex_lock(&c->log_mutex);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300192 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300193 if (c->ro_error) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300194 err = -EROFS;
195 goto out_unlock;
196 }
197
198 /* Make sure we have enough space in the log */
199 if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
200 dbg_log("not enough log space - %lld, required %d",
201 empty_log_bytes(c), c->min_log_bytes);
202 ubifs_commit_required(c);
203 err = -EAGAIN;
204 goto out_unlock;
205 }
206
207 /*
Artem Bityutskiy7d4e9cc2009-03-20 19:11:12 +0200208 * Make sure the amount of space in buds will not exceed the
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300209 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
210 * limits.
211 *
212 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
213 * because we are holding @c->log_mutex. All @c->bud_bytes take place
214 * when both @c->log_mutex and @c->bud_bytes are locked.
215 */
216 if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
217 dbg_log("bud bytes %lld (%lld max), require commit",
218 c->bud_bytes, c->max_bud_bytes);
219 ubifs_commit_required(c);
220 err = -EAGAIN;
221 goto out_unlock;
222 }
223
224 /*
225 * If the journal is full enough - start background commit. Note, it is
226 * OK to read 'c->cmt_state' without spinlock because integer reads
227 * are atomic in the kernel.
228 */
229 if (c->bud_bytes >= c->bg_bud_bytes &&
230 c->cmt_state == COMMIT_RESTING) {
231 dbg_log("bud bytes %lld (%lld max), initiate BG commit",
232 c->bud_bytes, c->max_bud_bytes);
233 ubifs_request_bg_commit(c);
234 }
235
236 bud->lnum = lnum;
237 bud->start = offs;
238 bud->jhead = jhead;
239
240 ref->ch.node_type = UBIFS_REF_NODE;
241 ref->lnum = cpu_to_le32(bud->lnum);
242 ref->offs = cpu_to_le32(bud->start);
243 ref->jhead = cpu_to_le32(jhead);
244
245 if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300246 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300247 c->lhead_offs = 0;
248 }
249
250 if (c->lhead_offs == 0) {
251 /* Must ensure next log LEB has been unmapped */
252 err = ubifs_leb_unmap(c, c->lhead_lnum);
253 if (err)
254 goto out_unlock;
255 }
256
257 if (bud->start == 0) {
258 /*
259 * Before writing the LEB reference which refers an empty LEB
260 * to the log, we have to make sure it is mapped, because
261 * otherwise we'd risk to refer an LEB with garbage in case of
262 * an unclean reboot, because the target LEB might have been
263 * unmapped, but not yet physically erased.
264 */
265 err = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM);
266 if (err)
267 goto out_unlock;
268 }
269
270 dbg_log("write ref LEB %d:%d",
271 c->lhead_lnum, c->lhead_offs);
272 err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
273 c->lhead_offs, UBI_SHORTTERM);
274 if (err)
275 goto out_unlock;
276
277 c->lhead_offs += c->ref_node_alsz;
278
279 ubifs_add_bud(c, bud);
280
281 mutex_unlock(&c->log_mutex);
282 kfree(ref);
283 return 0;
284
285out_unlock:
Adrian Hunter2fb42b12008-07-18 17:56:37 +0300286 if (err != -EAGAIN)
287 ubifs_ro_mode(c, err);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300288 mutex_unlock(&c->log_mutex);
289 kfree(ref);
290 kfree(bud);
291 return err;
292}
293
294/**
295 * remove_buds - remove used buds.
296 * @c: UBIFS file-system description object
297 *
298 * This function removes use buds from the buds tree. It does not remove the
299 * buds which are pointed to by journal heads.
300 */
301static void remove_buds(struct ubifs_info *c)
302{
303 struct rb_node *p;
304
305 ubifs_assert(list_empty(&c->old_buds));
306 c->cmt_bud_bytes = 0;
307 spin_lock(&c->buds_lock);
308 p = rb_first(&c->buds);
309 while (p) {
310 struct rb_node *p1 = p;
311 struct ubifs_bud *bud;
312 struct ubifs_wbuf *wbuf;
313
314 p = rb_next(p);
315 bud = rb_entry(p1, struct ubifs_bud, rb);
316 wbuf = &c->jheads[bud->jhead].wbuf;
317
318 if (wbuf->lnum == bud->lnum) {
319 /*
320 * Do not remove buds which are pointed to by journal
321 * heads (non-closed buds).
322 */
323 c->cmt_bud_bytes += wbuf->offs - bud->start;
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300324 dbg_log("preserve %d:%d, jhead %s, bud bytes %d, "
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300325 "cmt_bud_bytes %lld", bud->lnum, bud->start,
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300326 dbg_jhead(bud->jhead), wbuf->offs - bud->start,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300327 c->cmt_bud_bytes);
328 bud->start = wbuf->offs;
329 } else {
330 c->cmt_bud_bytes += c->leb_size - bud->start;
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300331 dbg_log("remove %d:%d, jhead %s, bud bytes %d, "
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300332 "cmt_bud_bytes %lld", bud->lnum, bud->start,
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300333 dbg_jhead(bud->jhead), c->leb_size - bud->start,
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300334 c->cmt_bud_bytes);
335 rb_erase(p1, &c->buds);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300336 /*
337 * If the commit does not finish, the recovery will need
338 * to replay the journal, in which case the old buds
339 * must be unchanged. Do not release them until post
340 * commit i.e. do not allow them to be garbage
341 * collected.
342 */
Eric Sesterhennec328162009-02-13 09:13:11 +0100343 list_move(&bud->list, &c->old_buds);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300344 }
345 }
346 spin_unlock(&c->buds_lock);
347}
348
349/**
350 * ubifs_log_start_commit - start commit.
351 * @c: UBIFS file-system description object
352 * @ltail_lnum: return new log tail LEB number
353 *
354 * The commit operation starts with writing "commit start" node to the log and
355 * reference nodes for all journal heads which will define new journal after
356 * the commit has been finished. The commit start and reference nodes are
357 * written in one go to the nearest empty log LEB (hence, when commit is
358 * finished UBIFS may safely unmap all the previous log LEBs). This function
359 * returns zero in case of success and a negative error code in case of
360 * failure.
361 */
362int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
363{
364 void *buf;
365 struct ubifs_cs_node *cs;
366 struct ubifs_ref_node *ref;
367 int err, i, max_len, len;
368
369 err = dbg_check_bud_bytes(c);
370 if (err)
371 return err;
372
373 max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
374 max_len = ALIGN(max_len, c->min_io_size);
375 buf = cs = kmalloc(max_len, GFP_NOFS);
376 if (!buf)
377 return -ENOMEM;
378
379 cs->ch.node_type = UBIFS_CS_NODE;
Artem Bityutskiy014eb042008-07-21 17:14:29 +0300380 cs->cmt_no = cpu_to_le64(c->cmt_no);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300381 ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
382
383 /*
384 * Note, we do not lock 'c->log_mutex' because this is the commit start
385 * phase and we are exclusively using the log. And we do not lock
386 * write-buffer because nobody can write to the file-system at this
387 * phase.
388 */
389
390 len = UBIFS_CS_NODE_SZ;
391 for (i = 0; i < c->jhead_cnt; i++) {
392 int lnum = c->jheads[i].wbuf.lnum;
393 int offs = c->jheads[i].wbuf.offs;
394
395 if (lnum == -1 || offs == c->leb_size)
396 continue;
397
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300398 dbg_log("add ref to LEB %d:%d for jhead %s",
399 lnum, offs, dbg_jhead(i));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300400 ref = buf + len;
401 ref->ch.node_type = UBIFS_REF_NODE;
402 ref->lnum = cpu_to_le32(lnum);
403 ref->offs = cpu_to_le32(offs);
404 ref->jhead = cpu_to_le32(i);
405
406 ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
407 len += UBIFS_REF_NODE_SZ;
408 }
409
410 ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
411
412 /* Switch to the next log LEB */
413 if (c->lhead_offs) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300414 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300415 c->lhead_offs = 0;
416 }
417
418 if (c->lhead_offs == 0) {
419 /* Must ensure next LEB has been unmapped */
420 err = ubifs_leb_unmap(c, c->lhead_lnum);
421 if (err)
422 goto out;
423 }
424
425 len = ALIGN(len, c->min_io_size);
426 dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
427 err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM);
428 if (err)
429 goto out;
430
431 *ltail_lnum = c->lhead_lnum;
432
433 c->lhead_offs += len;
434 if (c->lhead_offs == c->leb_size) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300435 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300436 c->lhead_offs = 0;
437 }
438
439 remove_buds(c);
440
441 /*
442 * We have started the commit and now users may use the rest of the log
443 * for new writes.
444 */
445 c->min_log_bytes = 0;
446
447out:
448 kfree(buf);
449 return err;
450}
451
452/**
453 * ubifs_log_end_commit - end commit.
454 * @c: UBIFS file-system description object
455 * @ltail_lnum: new log tail LEB number
456 *
457 * This function is called on when the commit operation was finished. It
458 * moves log tail to new position and unmaps LEBs which contain obsolete data.
459 * Returns zero in case of success and a negative error code in case of
460 * failure.
461 */
462int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
463{
464 int err;
465
466 /*
467 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
468 * writes during commit. Its only short "commit" start phase when
469 * writers are blocked.
470 */
471 mutex_lock(&c->log_mutex);
472
473 dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
474 c->ltail_lnum, ltail_lnum);
475
476 c->ltail_lnum = ltail_lnum;
477 /*
478 * The commit is finished and from now on it must be guaranteed that
479 * there is always enough space for the next commit.
480 */
481 c->min_log_bytes = c->leb_size;
482
483 spin_lock(&c->buds_lock);
484 c->bud_bytes -= c->cmt_bud_bytes;
485 spin_unlock(&c->buds_lock);
486
487 err = dbg_check_bud_bytes(c);
488
489 mutex_unlock(&c->log_mutex);
490 return err;
491}
492
493/**
494 * ubifs_log_post_commit - things to do after commit is completed.
495 * @c: UBIFS file-system description object
496 * @old_ltail_lnum: old log tail LEB number
497 *
498 * Release buds only after commit is completed, because they must be unchanged
499 * if recovery is needed.
500 *
501 * Unmap log LEBs only after commit is completed, because they may be needed for
502 * recovery.
503 *
504 * This function returns %0 on success and a negative error code on failure.
505 */
506int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
507{
508 int lnum, err = 0;
509
510 while (!list_empty(&c->old_buds)) {
511 struct ubifs_bud *bud;
512
513 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
514 err = ubifs_return_leb(c, bud->lnum);
515 if (err)
516 return err;
517 list_del(&bud->list);
518 kfree(bud);
519 }
520 mutex_lock(&c->log_mutex);
521 for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300522 lnum = ubifs_next_log_lnum(c, lnum)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300523 dbg_log("unmap log LEB %d", lnum);
524 err = ubifs_leb_unmap(c, lnum);
525 if (err)
526 goto out;
527 }
528out:
529 mutex_unlock(&c->log_mutex);
530 return err;
531}
532
533/**
534 * struct done_ref - references that have been done.
535 * @rb: rb-tree node
536 * @lnum: LEB number
537 */
538struct done_ref {
539 struct rb_node rb;
540 int lnum;
541};
542
543/**
544 * done_already - determine if a reference has been done already.
545 * @done_tree: rb-tree to store references that have been done
546 * @lnum: LEB number of reference
547 *
548 * This function returns %1 if the reference has been done, %0 if not, otherwise
549 * a negative error code is returned.
550 */
551static int done_already(struct rb_root *done_tree, int lnum)
552{
553 struct rb_node **p = &done_tree->rb_node, *parent = NULL;
554 struct done_ref *dr;
555
556 while (*p) {
557 parent = *p;
558 dr = rb_entry(parent, struct done_ref, rb);
559 if (lnum < dr->lnum)
560 p = &(*p)->rb_left;
561 else if (lnum > dr->lnum)
562 p = &(*p)->rb_right;
563 else
564 return 1;
565 }
566
567 dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
568 if (!dr)
569 return -ENOMEM;
570
571 dr->lnum = lnum;
572
573 rb_link_node(&dr->rb, parent, p);
574 rb_insert_color(&dr->rb, done_tree);
575
576 return 0;
577}
578
579/**
580 * destroy_done_tree - destroy the done tree.
581 * @done_tree: done tree to destroy
582 */
583static void destroy_done_tree(struct rb_root *done_tree)
584{
585 struct rb_node *this = done_tree->rb_node;
586 struct done_ref *dr;
587
588 while (this) {
589 if (this->rb_left) {
590 this = this->rb_left;
591 continue;
592 } else if (this->rb_right) {
593 this = this->rb_right;
594 continue;
595 }
596 dr = rb_entry(this, struct done_ref, rb);
597 this = rb_parent(this);
598 if (this) {
599 if (this->rb_left == &dr->rb)
600 this->rb_left = NULL;
601 else
602 this->rb_right = NULL;
603 }
604 kfree(dr);
605 }
606}
607
608/**
609 * add_node - add a node to the consolidated log.
610 * @c: UBIFS file-system description object
611 * @buf: buffer to which to add
612 * @lnum: LEB number to which to write is passed and returned here
613 * @offs: offset to where to write is passed and returned here
614 * @node: node to add
615 *
616 * This function returns %0 on success and a negative error code on failure.
617 */
618static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
619 void *node)
620{
621 struct ubifs_ch *ch = node;
622 int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
623
624 if (len > remains) {
625 int sz = ALIGN(*offs, c->min_io_size), err;
626
627 ubifs_pad(c, buf + *offs, sz - *offs);
628 err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM);
629 if (err)
630 return err;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300631 *lnum = ubifs_next_log_lnum(c, *lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300632 *offs = 0;
633 }
634 memcpy(buf + *offs, node, len);
635 *offs += ALIGN(len, 8);
636 return 0;
637}
638
639/**
640 * ubifs_consolidate_log - consolidate the log.
641 * @c: UBIFS file-system description object
642 *
643 * Repeated failed commits could cause the log to be full, but at least 1 LEB is
644 * needed for commit. This function rewrites the reference nodes in the log
645 * omitting duplicates, and failed CS nodes, and leaving no gaps.
646 *
647 * This function returns %0 on success and a negative error code on failure.
648 */
649int ubifs_consolidate_log(struct ubifs_info *c)
650{
651 struct ubifs_scan_leb *sleb;
652 struct ubifs_scan_node *snod;
653 struct rb_root done_tree = RB_ROOT;
654 int lnum, err, first = 1, write_lnum, offs = 0;
655 void *buf;
656
657 dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
658 c->lhead_lnum);
659 buf = vmalloc(c->leb_size);
660 if (!buf)
661 return -ENOMEM;
662 lnum = c->ltail_lnum;
663 write_lnum = lnum;
664 while (1) {
Artem Bityutskiy348709b2009-08-25 15:00:55 +0300665 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300666 if (IS_ERR(sleb)) {
667 err = PTR_ERR(sleb);
668 goto out_free;
669 }
670 list_for_each_entry(snod, &sleb->nodes, list) {
671 switch (snod->type) {
672 case UBIFS_REF_NODE: {
673 struct ubifs_ref_node *ref = snod->node;
674 int ref_lnum = le32_to_cpu(ref->lnum);
675
676 err = done_already(&done_tree, ref_lnum);
677 if (err < 0)
678 goto out_scan;
679 if (err != 1) {
680 err = add_node(c, buf, &write_lnum,
681 &offs, snod->node);
682 if (err)
683 goto out_scan;
684 }
685 break;
686 }
687 case UBIFS_CS_NODE:
688 if (!first)
689 break;
690 err = add_node(c, buf, &write_lnum, &offs,
691 snod->node);
692 if (err)
693 goto out_scan;
694 first = 0;
695 break;
696 }
697 }
698 ubifs_scan_destroy(sleb);
699 if (lnum == c->lhead_lnum)
700 break;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300701 lnum = ubifs_next_log_lnum(c, lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300702 }
703 if (offs) {
704 int sz = ALIGN(offs, c->min_io_size);
705
706 ubifs_pad(c, buf + offs, sz - offs);
707 err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM);
708 if (err)
709 goto out_free;
710 offs = ALIGN(offs, c->min_io_size);
711 }
712 destroy_done_tree(&done_tree);
713 vfree(buf);
714 if (write_lnum == c->lhead_lnum) {
715 ubifs_err("log is too full");
716 return -EINVAL;
717 }
718 /* Unmap remaining LEBs */
719 lnum = write_lnum;
720 do {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300721 lnum = ubifs_next_log_lnum(c, lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300722 err = ubifs_leb_unmap(c, lnum);
723 if (err)
724 return err;
725 } while (lnum != c->lhead_lnum);
726 c->lhead_lnum = write_lnum;
727 c->lhead_offs = offs;
728 dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
729 return 0;
730
731out_scan:
732 ubifs_scan_destroy(sleb);
733out_free:
734 destroy_done_tree(&done_tree);
735 vfree(buf);
736 return err;
737}
738
739#ifdef CONFIG_UBIFS_FS_DEBUG
740
741/**
742 * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
743 * @c: UBIFS file-system description object
744 *
745 * This function makes sure the amount of flash space used by closed buds
746 * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
747 * case of failure.
748 */
749static int dbg_check_bud_bytes(struct ubifs_info *c)
750{
751 int i, err = 0;
752 struct ubifs_bud *bud;
753 long long bud_bytes = 0;
754
755 if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
756 return 0;
757
758 spin_lock(&c->buds_lock);
759 for (i = 0; i < c->jhead_cnt; i++)
760 list_for_each_entry(bud, &c->jheads[i].buds_list, list)
761 bud_bytes += c->leb_size - bud->start;
762
763 if (c->bud_bytes != bud_bytes) {
764 ubifs_err("bad bud_bytes %lld, calculated %lld",
765 c->bud_bytes, bud_bytes);
766 err = -EINVAL;
767 }
768 spin_unlock(&c->buds_lock);
769
770 return err;
771}
772
773#endif /* CONFIG_UBIFS_FS_DEBUG */