blob: a902c5919e423ca619fcf0508345909b51ec99f8 [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
Artem Bityutskiy1e517642008-07-14 19:08:37 +030032static int dbg_check_bud_bytes(struct ubifs_info *c);
Artem Bityutskiy1e517642008-07-14 19:08:37 +030033
34/**
35 * ubifs_search_bud - search bud LEB.
36 * @c: UBIFS file-system description object
37 * @lnum: logical eraseblock number to search
38 *
39 * This function searches bud LEB @lnum. Returns bud description object in case
40 * of success and %NULL if there is no bud with this LEB number.
41 */
42struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
43{
44 struct rb_node *p;
45 struct ubifs_bud *bud;
46
47 spin_lock(&c->buds_lock);
48 p = c->buds.rb_node;
49 while (p) {
50 bud = rb_entry(p, struct ubifs_bud, rb);
51 if (lnum < bud->lnum)
52 p = p->rb_left;
53 else if (lnum > bud->lnum)
54 p = p->rb_right;
55 else {
56 spin_unlock(&c->buds_lock);
57 return bud;
58 }
59 }
60 spin_unlock(&c->buds_lock);
61 return NULL;
62}
63
64/**
65 * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
66 * @c: UBIFS file-system description object
67 * @lnum: logical eraseblock number to search
68 *
69 * This functions returns the wbuf for @lnum or %NULL if there is not one.
70 */
71struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
72{
73 struct rb_node *p;
74 struct ubifs_bud *bud;
75 int jhead;
76
77 if (!c->jheads)
78 return NULL;
79
80 spin_lock(&c->buds_lock);
81 p = c->buds.rb_node;
82 while (p) {
83 bud = rb_entry(p, struct ubifs_bud, rb);
84 if (lnum < bud->lnum)
85 p = p->rb_left;
86 else if (lnum > bud->lnum)
87 p = p->rb_right;
88 else {
89 jhead = bud->jhead;
90 spin_unlock(&c->buds_lock);
91 return &c->jheads[jhead].wbuf;
92 }
93 }
94 spin_unlock(&c->buds_lock);
95 return NULL;
96}
97
98/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +030099 * empty_log_bytes - calculate amount of empty space in the log.
100 * @c: UBIFS file-system description object
101 */
102static inline long long empty_log_bytes(const struct ubifs_info *c)
103{
104 long long h, t;
105
106 h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
107 t = (long long)c->ltail_lnum * c->leb_size;
108
109 if (h >= t)
110 return c->log_bytes - h + t;
111 else
112 return t - h;
113}
114
115/**
116 * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
117 * @c: UBIFS file-system description object
118 * @bud: the bud to add
119 */
120void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
121{
122 struct rb_node **p, *parent = NULL;
123 struct ubifs_bud *b;
124 struct ubifs_jhead *jhead;
125
126 spin_lock(&c->buds_lock);
127 p = &c->buds.rb_node;
128 while (*p) {
129 parent = *p;
130 b = rb_entry(parent, struct ubifs_bud, rb);
131 ubifs_assert(bud->lnum != b->lnum);
132 if (bud->lnum < b->lnum)
133 p = &(*p)->rb_left;
134 else
135 p = &(*p)->rb_right;
136 }
137
138 rb_link_node(&bud->rb, parent, p);
139 rb_insert_color(&bud->rb, &c->buds);
140 if (c->jheads) {
141 jhead = &c->jheads[bud->jhead];
142 list_add_tail(&bud->list, &jhead->buds_list);
143 } else
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300144 ubifs_assert(c->replaying && c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300145
146 /*
147 * Note, although this is a new bud, we anyway account this space now,
148 * before any data has been written to it, because this is about to
149 * guarantee fixed mount time, and this bud will anyway be read and
150 * scanned.
151 */
152 c->bud_bytes += c->leb_size - bud->start;
153
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300154 dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
155 bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300156 spin_unlock(&c->buds_lock);
157}
158
159/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300160 * ubifs_add_bud_to_log - add a new bud to the log.
161 * @c: UBIFS file-system description object
162 * @jhead: journal head the bud belongs to
163 * @lnum: LEB number of the bud
164 * @offs: starting offset of the bud
165 *
166 * This function writes reference node for the new bud LEB @lnum it to the log,
167 * and adds it to the buds tress. It also makes sure that log size does not
168 * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
169 * %-EAGAIN if commit is required, and a negative error codes in case of
170 * failure.
171 */
172int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
173{
174 int err;
175 struct ubifs_bud *bud;
176 struct ubifs_ref_node *ref;
177
178 bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
179 if (!bud)
180 return -ENOMEM;
181 ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
182 if (!ref) {
183 kfree(bud);
184 return -ENOMEM;
185 }
186
187 mutex_lock(&c->log_mutex);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300188 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300189 if (c->ro_error) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300190 err = -EROFS;
191 goto out_unlock;
192 }
193
194 /* Make sure we have enough space in the log */
195 if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
196 dbg_log("not enough log space - %lld, required %d",
197 empty_log_bytes(c), c->min_log_bytes);
198 ubifs_commit_required(c);
199 err = -EAGAIN;
200 goto out_unlock;
201 }
202
203 /*
Artem Bityutskiy7d4e9cc2009-03-20 19:11:12 +0200204 * Make sure the amount of space in buds will not exceed the
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300205 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
206 * limits.
207 *
208 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
209 * because we are holding @c->log_mutex. All @c->bud_bytes take place
210 * when both @c->log_mutex and @c->bud_bytes are locked.
211 */
212 if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
213 dbg_log("bud bytes %lld (%lld max), require commit",
214 c->bud_bytes, c->max_bud_bytes);
215 ubifs_commit_required(c);
216 err = -EAGAIN;
217 goto out_unlock;
218 }
219
220 /*
221 * If the journal is full enough - start background commit. Note, it is
222 * OK to read 'c->cmt_state' without spinlock because integer reads
223 * are atomic in the kernel.
224 */
225 if (c->bud_bytes >= c->bg_bud_bytes &&
226 c->cmt_state == COMMIT_RESTING) {
227 dbg_log("bud bytes %lld (%lld max), initiate BG commit",
228 c->bud_bytes, c->max_bud_bytes);
229 ubifs_request_bg_commit(c);
230 }
231
232 bud->lnum = lnum;
233 bud->start = offs;
234 bud->jhead = jhead;
235
236 ref->ch.node_type = UBIFS_REF_NODE;
237 ref->lnum = cpu_to_le32(bud->lnum);
238 ref->offs = cpu_to_le32(bud->start);
239 ref->jhead = cpu_to_le32(jhead);
240
241 if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300242 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300243 c->lhead_offs = 0;
244 }
245
246 if (c->lhead_offs == 0) {
247 /* Must ensure next log LEB has been unmapped */
248 err = ubifs_leb_unmap(c, c->lhead_lnum);
249 if (err)
250 goto out_unlock;
251 }
252
253 if (bud->start == 0) {
254 /*
255 * Before writing the LEB reference which refers an empty LEB
256 * to the log, we have to make sure it is mapped, because
257 * otherwise we'd risk to refer an LEB with garbage in case of
258 * an unclean reboot, because the target LEB might have been
259 * unmapped, but not yet physically erased.
260 */
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200261 err = ubifs_leb_map(c, bud->lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300262 if (err)
263 goto out_unlock;
264 }
265
266 dbg_log("write ref LEB %d:%d",
267 c->lhead_lnum, c->lhead_offs);
268 err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200269 c->lhead_offs);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300270 if (err)
271 goto out_unlock;
272
273 c->lhead_offs += c->ref_node_alsz;
274
275 ubifs_add_bud(c, bud);
276
277 mutex_unlock(&c->log_mutex);
278 kfree(ref);
279 return 0;
280
281out_unlock:
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300282 mutex_unlock(&c->log_mutex);
283 kfree(ref);
284 kfree(bud);
285 return err;
286}
287
288/**
289 * remove_buds - remove used buds.
290 * @c: UBIFS file-system description object
291 *
292 * This function removes use buds from the buds tree. It does not remove the
293 * buds which are pointed to by journal heads.
294 */
295static void remove_buds(struct ubifs_info *c)
296{
297 struct rb_node *p;
298
299 ubifs_assert(list_empty(&c->old_buds));
300 c->cmt_bud_bytes = 0;
301 spin_lock(&c->buds_lock);
302 p = rb_first(&c->buds);
303 while (p) {
304 struct rb_node *p1 = p;
305 struct ubifs_bud *bud;
306 struct ubifs_wbuf *wbuf;
307
308 p = rb_next(p);
309 bud = rb_entry(p1, struct ubifs_bud, rb);
310 wbuf = &c->jheads[bud->jhead].wbuf;
311
312 if (wbuf->lnum == bud->lnum) {
313 /*
314 * Do not remove buds which are pointed to by journal
315 * heads (non-closed buds).
316 */
317 c->cmt_bud_bytes += wbuf->offs - bud->start;
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300318 dbg_log("preserve %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
319 bud->lnum, bud->start, dbg_jhead(bud->jhead),
320 wbuf->offs - bud->start, c->cmt_bud_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300321 bud->start = wbuf->offs;
322 } else {
323 c->cmt_bud_bytes += c->leb_size - bud->start;
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300324 dbg_log("remove %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
325 bud->lnum, bud->start, dbg_jhead(bud->jhead),
326 c->leb_size - bud->start, c->cmt_bud_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300327 rb_erase(p1, &c->buds);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300328 /*
329 * If the commit does not finish, the recovery will need
330 * to replay the journal, in which case the old buds
331 * must be unchanged. Do not release them until post
332 * commit i.e. do not allow them to be garbage
333 * collected.
334 */
Eric Sesterhennec328162009-02-13 09:13:11 +0100335 list_move(&bud->list, &c->old_buds);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300336 }
337 }
338 spin_unlock(&c->buds_lock);
339}
340
341/**
342 * ubifs_log_start_commit - start commit.
343 * @c: UBIFS file-system description object
344 * @ltail_lnum: return new log tail LEB number
345 *
346 * The commit operation starts with writing "commit start" node to the log and
347 * reference nodes for all journal heads which will define new journal after
348 * the commit has been finished. The commit start and reference nodes are
349 * written in one go to the nearest empty log LEB (hence, when commit is
350 * finished UBIFS may safely unmap all the previous log LEBs). This function
351 * returns zero in case of success and a negative error code in case of
352 * failure.
353 */
354int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
355{
356 void *buf;
357 struct ubifs_cs_node *cs;
358 struct ubifs_ref_node *ref;
359 int err, i, max_len, len;
360
361 err = dbg_check_bud_bytes(c);
362 if (err)
363 return err;
364
365 max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
366 max_len = ALIGN(max_len, c->min_io_size);
367 buf = cs = kmalloc(max_len, GFP_NOFS);
368 if (!buf)
369 return -ENOMEM;
370
371 cs->ch.node_type = UBIFS_CS_NODE;
Artem Bityutskiy014eb042008-07-21 17:14:29 +0300372 cs->cmt_no = cpu_to_le64(c->cmt_no);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300373 ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
374
375 /*
376 * Note, we do not lock 'c->log_mutex' because this is the commit start
377 * phase and we are exclusively using the log. And we do not lock
378 * write-buffer because nobody can write to the file-system at this
379 * phase.
380 */
381
382 len = UBIFS_CS_NODE_SZ;
383 for (i = 0; i < c->jhead_cnt; i++) {
384 int lnum = c->jheads[i].wbuf.lnum;
385 int offs = c->jheads[i].wbuf.offs;
386
387 if (lnum == -1 || offs == c->leb_size)
388 continue;
389
Artem Bityutskiy77a7ae52009-09-15 15:03:51 +0300390 dbg_log("add ref to LEB %d:%d for jhead %s",
391 lnum, offs, dbg_jhead(i));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300392 ref = buf + len;
393 ref->ch.node_type = UBIFS_REF_NODE;
394 ref->lnum = cpu_to_le32(lnum);
395 ref->offs = cpu_to_le32(offs);
396 ref->jhead = cpu_to_le32(i);
397
398 ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
399 len += UBIFS_REF_NODE_SZ;
400 }
401
402 ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
403
404 /* Switch to the next log LEB */
405 if (c->lhead_offs) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300406 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300407 c->lhead_offs = 0;
408 }
409
410 if (c->lhead_offs == 0) {
411 /* Must ensure next LEB has been unmapped */
412 err = ubifs_leb_unmap(c, c->lhead_lnum);
413 if (err)
414 goto out;
415 }
416
417 len = ALIGN(len, c->min_io_size);
418 dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200419 err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300420 if (err)
421 goto out;
422
423 *ltail_lnum = c->lhead_lnum;
424
425 c->lhead_offs += len;
426 if (c->lhead_offs == c->leb_size) {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300427 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300428 c->lhead_offs = 0;
429 }
430
431 remove_buds(c);
432
433 /*
434 * We have started the commit and now users may use the rest of the log
435 * for new writes.
436 */
437 c->min_log_bytes = 0;
438
439out:
440 kfree(buf);
441 return err;
442}
443
444/**
445 * ubifs_log_end_commit - end commit.
446 * @c: UBIFS file-system description object
447 * @ltail_lnum: new log tail LEB number
448 *
449 * This function is called on when the commit operation was finished. It
450 * moves log tail to new position and unmaps LEBs which contain obsolete data.
451 * Returns zero in case of success and a negative error code in case of
452 * failure.
453 */
454int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
455{
456 int err;
457
458 /*
459 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
460 * writes during commit. Its only short "commit" start phase when
461 * writers are blocked.
462 */
463 mutex_lock(&c->log_mutex);
464
465 dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
466 c->ltail_lnum, ltail_lnum);
467
468 c->ltail_lnum = ltail_lnum;
469 /*
470 * The commit is finished and from now on it must be guaranteed that
471 * there is always enough space for the next commit.
472 */
473 c->min_log_bytes = c->leb_size;
474
475 spin_lock(&c->buds_lock);
476 c->bud_bytes -= c->cmt_bud_bytes;
477 spin_unlock(&c->buds_lock);
478
479 err = dbg_check_bud_bytes(c);
480
481 mutex_unlock(&c->log_mutex);
482 return err;
483}
484
485/**
486 * ubifs_log_post_commit - things to do after commit is completed.
487 * @c: UBIFS file-system description object
488 * @old_ltail_lnum: old log tail LEB number
489 *
490 * Release buds only after commit is completed, because they must be unchanged
491 * if recovery is needed.
492 *
493 * Unmap log LEBs only after commit is completed, because they may be needed for
494 * recovery.
495 *
496 * This function returns %0 on success and a negative error code on failure.
497 */
498int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
499{
500 int lnum, err = 0;
501
502 while (!list_empty(&c->old_buds)) {
503 struct ubifs_bud *bud;
504
505 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
506 err = ubifs_return_leb(c, bud->lnum);
507 if (err)
508 return err;
509 list_del(&bud->list);
510 kfree(bud);
511 }
512 mutex_lock(&c->log_mutex);
513 for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300514 lnum = ubifs_next_log_lnum(c, lnum)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300515 dbg_log("unmap log LEB %d", lnum);
516 err = ubifs_leb_unmap(c, lnum);
517 if (err)
518 goto out;
519 }
520out:
521 mutex_unlock(&c->log_mutex);
522 return err;
523}
524
525/**
526 * struct done_ref - references that have been done.
527 * @rb: rb-tree node
528 * @lnum: LEB number
529 */
530struct done_ref {
531 struct rb_node rb;
532 int lnum;
533};
534
535/**
536 * done_already - determine if a reference has been done already.
537 * @done_tree: rb-tree to store references that have been done
538 * @lnum: LEB number of reference
539 *
540 * This function returns %1 if the reference has been done, %0 if not, otherwise
541 * a negative error code is returned.
542 */
543static int done_already(struct rb_root *done_tree, int lnum)
544{
545 struct rb_node **p = &done_tree->rb_node, *parent = NULL;
546 struct done_ref *dr;
547
548 while (*p) {
549 parent = *p;
550 dr = rb_entry(parent, struct done_ref, rb);
551 if (lnum < dr->lnum)
552 p = &(*p)->rb_left;
553 else if (lnum > dr->lnum)
554 p = &(*p)->rb_right;
555 else
556 return 1;
557 }
558
559 dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
560 if (!dr)
561 return -ENOMEM;
562
563 dr->lnum = lnum;
564
565 rb_link_node(&dr->rb, parent, p);
566 rb_insert_color(&dr->rb, done_tree);
567
568 return 0;
569}
570
571/**
572 * destroy_done_tree - destroy the done tree.
573 * @done_tree: done tree to destroy
574 */
575static void destroy_done_tree(struct rb_root *done_tree)
576{
Cody P Schaferbb25e492014-01-23 15:56:08 -0800577 struct done_ref *dr, *n;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300578
Cody P Schaferbb25e492014-01-23 15:56:08 -0800579 rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300580 kfree(dr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300581}
582
583/**
584 * add_node - add a node to the consolidated log.
585 * @c: UBIFS file-system description object
586 * @buf: buffer to which to add
587 * @lnum: LEB number to which to write is passed and returned here
588 * @offs: offset to where to write is passed and returned here
589 * @node: node to add
590 *
591 * This function returns %0 on success and a negative error code on failure.
592 */
593static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
594 void *node)
595{
596 struct ubifs_ch *ch = node;
597 int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
598
599 if (len > remains) {
600 int sz = ALIGN(*offs, c->min_io_size), err;
601
602 ubifs_pad(c, buf + *offs, sz - *offs);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200603 err = ubifs_leb_change(c, *lnum, buf, sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300604 if (err)
605 return err;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300606 *lnum = ubifs_next_log_lnum(c, *lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300607 *offs = 0;
608 }
609 memcpy(buf + *offs, node, len);
610 *offs += ALIGN(len, 8);
611 return 0;
612}
613
614/**
615 * ubifs_consolidate_log - consolidate the log.
616 * @c: UBIFS file-system description object
617 *
618 * Repeated failed commits could cause the log to be full, but at least 1 LEB is
619 * needed for commit. This function rewrites the reference nodes in the log
620 * omitting duplicates, and failed CS nodes, and leaving no gaps.
621 *
622 * This function returns %0 on success and a negative error code on failure.
623 */
624int ubifs_consolidate_log(struct ubifs_info *c)
625{
626 struct ubifs_scan_leb *sleb;
627 struct ubifs_scan_node *snod;
628 struct rb_root done_tree = RB_ROOT;
629 int lnum, err, first = 1, write_lnum, offs = 0;
630 void *buf;
631
632 dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
633 c->lhead_lnum);
634 buf = vmalloc(c->leb_size);
635 if (!buf)
636 return -ENOMEM;
637 lnum = c->ltail_lnum;
638 write_lnum = lnum;
639 while (1) {
Artem Bityutskiy348709b2009-08-25 15:00:55 +0300640 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300641 if (IS_ERR(sleb)) {
642 err = PTR_ERR(sleb);
643 goto out_free;
644 }
645 list_for_each_entry(snod, &sleb->nodes, list) {
646 switch (snod->type) {
647 case UBIFS_REF_NODE: {
648 struct ubifs_ref_node *ref = snod->node;
649 int ref_lnum = le32_to_cpu(ref->lnum);
650
651 err = done_already(&done_tree, ref_lnum);
652 if (err < 0)
653 goto out_scan;
654 if (err != 1) {
655 err = add_node(c, buf, &write_lnum,
656 &offs, snod->node);
657 if (err)
658 goto out_scan;
659 }
660 break;
661 }
662 case UBIFS_CS_NODE:
663 if (!first)
664 break;
665 err = add_node(c, buf, &write_lnum, &offs,
666 snod->node);
667 if (err)
668 goto out_scan;
669 first = 0;
670 break;
671 }
672 }
673 ubifs_scan_destroy(sleb);
674 if (lnum == c->lhead_lnum)
675 break;
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300676 lnum = ubifs_next_log_lnum(c, lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300677 }
678 if (offs) {
679 int sz = ALIGN(offs, c->min_io_size);
680
681 ubifs_pad(c, buf + offs, sz - offs);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200682 err = ubifs_leb_change(c, write_lnum, buf, sz);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300683 if (err)
684 goto out_free;
685 offs = ALIGN(offs, c->min_io_size);
686 }
687 destroy_done_tree(&done_tree);
688 vfree(buf);
689 if (write_lnum == c->lhead_lnum) {
690 ubifs_err("log is too full");
691 return -EINVAL;
692 }
693 /* Unmap remaining LEBs */
694 lnum = write_lnum;
695 do {
Artem Bityutskiye11602e2011-05-06 17:52:32 +0300696 lnum = ubifs_next_log_lnum(c, lnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300697 err = ubifs_leb_unmap(c, lnum);
698 if (err)
699 return err;
700 } while (lnum != c->lhead_lnum);
701 c->lhead_lnum = write_lnum;
702 c->lhead_offs = offs;
703 dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
704 return 0;
705
706out_scan:
707 ubifs_scan_destroy(sleb);
708out_free:
709 destroy_done_tree(&done_tree);
710 vfree(buf);
711 return err;
712}
713
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300714/**
715 * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
716 * @c: UBIFS file-system description object
717 *
718 * This function makes sure the amount of flash space used by closed buds
719 * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
720 * case of failure.
721 */
722static int dbg_check_bud_bytes(struct ubifs_info *c)
723{
724 int i, err = 0;
725 struct ubifs_bud *bud;
726 long long bud_bytes = 0;
727
Artem Bityutskiy2b1844a2011-06-03 08:31:29 +0300728 if (!dbg_is_chk_gen(c))
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300729 return 0;
730
731 spin_lock(&c->buds_lock);
732 for (i = 0; i < c->jhead_cnt; i++)
733 list_for_each_entry(bud, &c->jheads[i].buds_list, list)
734 bud_bytes += c->leb_size - bud->start;
735
736 if (c->bud_bytes != bud_bytes) {
737 ubifs_err("bad bud_bytes %lld, calculated %lld",
738 c->bud_bytes, bud_bytes);
739 err = -EINVAL;
740 }
741 spin_unlock(&c->buds_lock);
742
743 return err;
744}