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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: 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/**
103 * 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
148 ubifs_assert(c->replaying && c->ro_mount);
149
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
158 dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
159 bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
160 spin_unlock(&c->buds_lock);
161}
162
163/**
164 * 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);
192 ubifs_assert(!c->ro_media && !c->ro_mount);
193 if (c->ro_error) {
194 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 /*
208 * Make sure the amount of space in buds will not exceed the
209 * '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) {
246 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
247 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 = ubifs_leb_map(c, 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:
286 mutex_unlock(&c->log_mutex);
287 kfree(ref);
288 kfree(bud);
289 return err;
290}
291
292/**
293 * remove_buds - remove used buds.
294 * @c: UBIFS file-system description object
295 *
296 * This function removes use buds from the buds tree. It does not remove the
297 * buds which are pointed to by journal heads.
298 */
299static void remove_buds(struct ubifs_info *c)
300{
301 struct rb_node *p;
302
303 ubifs_assert(list_empty(&c->old_buds));
304 c->cmt_bud_bytes = 0;
305 spin_lock(&c->buds_lock);
306 p = rb_first(&c->buds);
307 while (p) {
308 struct rb_node *p1 = p;
309 struct ubifs_bud *bud;
310 struct ubifs_wbuf *wbuf;
311
312 p = rb_next(p);
313 bud = rb_entry(p1, struct ubifs_bud, rb);
314 wbuf = &c->jheads[bud->jhead].wbuf;
315
316 if (wbuf->lnum == bud->lnum) {
317 /*
318 * Do not remove buds which are pointed to by journal
319 * heads (non-closed buds).
320 */
321 c->cmt_bud_bytes += wbuf->offs - bud->start;
322 dbg_log("preserve %d:%d, jhead %s, bud bytes %d, "
323 "cmt_bud_bytes %lld", bud->lnum, bud->start,
324 dbg_jhead(bud->jhead), wbuf->offs - bud->start,
325 c->cmt_bud_bytes);
326 bud->start = wbuf->offs;
327 } else {
328 c->cmt_bud_bytes += c->leb_size - bud->start;
329 dbg_log("remove %d:%d, jhead %s, bud bytes %d, "
330 "cmt_bud_bytes %lld", bud->lnum, bud->start,
331 dbg_jhead(bud->jhead), c->leb_size - bud->start,
332 c->cmt_bud_bytes);
333 rb_erase(p1, &c->buds);
334 /*
335 * If the commit does not finish, the recovery will need
336 * to replay the journal, in which case the old buds
337 * must be unchanged. Do not release them until post
338 * commit i.e. do not allow them to be garbage
339 * collected.
340 */
341 list_move(&bud->list, &c->old_buds);
342 }
343 }
344 spin_unlock(&c->buds_lock);
345}
346
347/**
348 * ubifs_log_start_commit - start commit.
349 * @c: UBIFS file-system description object
350 * @ltail_lnum: return new log tail LEB number
351 *
352 * The commit operation starts with writing "commit start" node to the log and
353 * reference nodes for all journal heads which will define new journal after
354 * the commit has been finished. The commit start and reference nodes are
355 * written in one go to the nearest empty log LEB (hence, when commit is
356 * finished UBIFS may safely unmap all the previous log LEBs). This function
357 * returns zero in case of success and a negative error code in case of
358 * failure.
359 */
360int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
361{
362 void *buf;
363 struct ubifs_cs_node *cs;
364 struct ubifs_ref_node *ref;
365 int err, i, max_len, len;
366
367 err = dbg_check_bud_bytes(c);
368 if (err)
369 return err;
370
371 max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
372 max_len = ALIGN(max_len, c->min_io_size);
373 buf = cs = kmalloc(max_len, GFP_NOFS);
374 if (!buf)
375 return -ENOMEM;
376
377 cs->ch.node_type = UBIFS_CS_NODE;
378 cs->cmt_no = cpu_to_le64(c->cmt_no);
379 ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
380
381 /*
382 * Note, we do not lock 'c->log_mutex' because this is the commit start
383 * phase and we are exclusively using the log. And we do not lock
384 * write-buffer because nobody can write to the file-system at this
385 * phase.
386 */
387
388 len = UBIFS_CS_NODE_SZ;
389 for (i = 0; i < c->jhead_cnt; i++) {
390 int lnum = c->jheads[i].wbuf.lnum;
391 int offs = c->jheads[i].wbuf.offs;
392
393 if (lnum == -1 || offs == c->leb_size)
394 continue;
395
396 dbg_log("add ref to LEB %d:%d for jhead %s",
397 lnum, offs, dbg_jhead(i));
398 ref = buf + len;
399 ref->ch.node_type = UBIFS_REF_NODE;
400 ref->lnum = cpu_to_le32(lnum);
401 ref->offs = cpu_to_le32(offs);
402 ref->jhead = cpu_to_le32(i);
403
404 ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
405 len += UBIFS_REF_NODE_SZ;
406 }
407
408 ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
409
410 /* Switch to the next log LEB */
411 if (c->lhead_offs) {
412 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
413 c->lhead_offs = 0;
414 }
415
416 if (c->lhead_offs == 0) {
417 /* Must ensure next LEB has been unmapped */
418 err = ubifs_leb_unmap(c, c->lhead_lnum);
419 if (err)
420 goto out;
421 }
422
423 len = ALIGN(len, c->min_io_size);
424 dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
425 err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM);
426 if (err)
427 goto out;
428
429 *ltail_lnum = c->lhead_lnum;
430
431 c->lhead_offs += len;
432 if (c->lhead_offs == c->leb_size) {
433 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
434 c->lhead_offs = 0;
435 }
436
437 remove_buds(c);
438
439 /*
440 * We have started the commit and now users may use the rest of the log
441 * for new writes.
442 */
443 c->min_log_bytes = 0;
444
445out:
446 kfree(buf);
447 return err;
448}
449
450/**
451 * ubifs_log_end_commit - end commit.
452 * @c: UBIFS file-system description object
453 * @ltail_lnum: new log tail LEB number
454 *
455 * This function is called on when the commit operation was finished. It
456 * moves log tail to new position and unmaps LEBs which contain obsolete data.
457 * Returns zero in case of success and a negative error code in case of
458 * failure.
459 */
460int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
461{
462 int err;
463
464 /*
465 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
466 * writes during commit. Its only short "commit" start phase when
467 * writers are blocked.
468 */
469 mutex_lock(&c->log_mutex);
470
471 dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
472 c->ltail_lnum, ltail_lnum);
473
474 c->ltail_lnum = ltail_lnum;
475 /*
476 * The commit is finished and from now on it must be guaranteed that
477 * there is always enough space for the next commit.
478 */
479 c->min_log_bytes = c->leb_size;
480
481 spin_lock(&c->buds_lock);
482 c->bud_bytes -= c->cmt_bud_bytes;
483 spin_unlock(&c->buds_lock);
484
485 err = dbg_check_bud_bytes(c);
486
487 mutex_unlock(&c->log_mutex);
488 return err;
489}
490
491/**
492 * ubifs_log_post_commit - things to do after commit is completed.
493 * @c: UBIFS file-system description object
494 * @old_ltail_lnum: old log tail LEB number
495 *
496 * Release buds only after commit is completed, because they must be unchanged
497 * if recovery is needed.
498 *
499 * Unmap log LEBs only after commit is completed, because they may be needed for
500 * recovery.
501 *
502 * This function returns %0 on success and a negative error code on failure.
503 */
504int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
505{
506 int lnum, err = 0;
507
508 while (!list_empty(&c->old_buds)) {
509 struct ubifs_bud *bud;
510
511 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
512 err = ubifs_return_leb(c, bud->lnum);
513 if (err)
514 return err;
515 list_del(&bud->list);
516 kfree(bud);
517 }
518 mutex_lock(&c->log_mutex);
519 for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
520 lnum = ubifs_next_log_lnum(c, lnum)) {
521 dbg_log("unmap log LEB %d", lnum);
522 err = ubifs_leb_unmap(c, lnum);
523 if (err)
524 goto out;
525 }
526out:
527 mutex_unlock(&c->log_mutex);
528 return err;
529}
530
531/**
532 * struct done_ref - references that have been done.
533 * @rb: rb-tree node
534 * @lnum: LEB number
535 */
536struct done_ref {
537 struct rb_node rb;
538 int lnum;
539};
540
541/**
542 * done_already - determine if a reference has been done already.
543 * @done_tree: rb-tree to store references that have been done
544 * @lnum: LEB number of reference
545 *
546 * This function returns %1 if the reference has been done, %0 if not, otherwise
547 * a negative error code is returned.
548 */
549static int done_already(struct rb_root *done_tree, int lnum)
550{
551 struct rb_node **p = &done_tree->rb_node, *parent = NULL;
552 struct done_ref *dr;
553
554 while (*p) {
555 parent = *p;
556 dr = rb_entry(parent, struct done_ref, rb);
557 if (lnum < dr->lnum)
558 p = &(*p)->rb_left;
559 else if (lnum > dr->lnum)
560 p = &(*p)->rb_right;
561 else
562 return 1;
563 }
564
565 dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
566 if (!dr)
567 return -ENOMEM;
568
569 dr->lnum = lnum;
570
571 rb_link_node(&dr->rb, parent, p);
572 rb_insert_color(&dr->rb, done_tree);
573
574 return 0;
575}
576
577/**
578 * destroy_done_tree - destroy the done tree.
579 * @done_tree: done tree to destroy
580 */
581static void destroy_done_tree(struct rb_root *done_tree)
582{
583 struct rb_node *this = done_tree->rb_node;
584 struct done_ref *dr;
585
586 while (this) {
587 if (this->rb_left) {
588 this = this->rb_left;
589 continue;
590 } else if (this->rb_right) {
591 this = this->rb_right;
592 continue;
593 }
594 dr = rb_entry(this, struct done_ref, rb);
595 this = rb_parent(this);
596 if (this) {
597 if (this->rb_left == &dr->rb)
598 this->rb_left = NULL;
599 else
600 this->rb_right = NULL;
601 }
602 kfree(dr);
603 }
604}
605
606/**
607 * add_node - add a node to the consolidated log.
608 * @c: UBIFS file-system description object
609 * @buf: buffer to which to add
610 * @lnum: LEB number to which to write is passed and returned here
611 * @offs: offset to where to write is passed and returned here
612 * @node: node to add
613 *
614 * This function returns %0 on success and a negative error code on failure.
615 */
616static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
617 void *node)
618{
619 struct ubifs_ch *ch = node;
620 int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
621
622 if (len > remains) {
623 int sz = ALIGN(*offs, c->min_io_size), err;
624
625 ubifs_pad(c, buf + *offs, sz - *offs);
626 err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM);
627 if (err)
628 return err;
629 *lnum = ubifs_next_log_lnum(c, *lnum);
630 *offs = 0;
631 }
632 memcpy(buf + *offs, node, len);
633 *offs += ALIGN(len, 8);
634 return 0;
635}
636
637/**
638 * ubifs_consolidate_log - consolidate the log.
639 * @c: UBIFS file-system description object
640 *
641 * Repeated failed commits could cause the log to be full, but at least 1 LEB is
642 * needed for commit. This function rewrites the reference nodes in the log
643 * omitting duplicates, and failed CS nodes, and leaving no gaps.
644 *
645 * This function returns %0 on success and a negative error code on failure.
646 */
647int ubifs_consolidate_log(struct ubifs_info *c)
648{
649 struct ubifs_scan_leb *sleb;
650 struct ubifs_scan_node *snod;
651 struct rb_root done_tree = RB_ROOT;
652 int lnum, err, first = 1, write_lnum, offs = 0;
653 void *buf;
654
655 dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
656 c->lhead_lnum);
657 buf = vmalloc(c->leb_size);
658 if (!buf)
659 return -ENOMEM;
660 lnum = c->ltail_lnum;
661 write_lnum = lnum;
662 while (1) {
663 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
664 if (IS_ERR(sleb)) {
665 err = PTR_ERR(sleb);
666 goto out_free;
667 }
668 list_for_each_entry(snod, &sleb->nodes, list) {
669 switch (snod->type) {
670 case UBIFS_REF_NODE: {
671 struct ubifs_ref_node *ref = snod->node;
672 int ref_lnum = le32_to_cpu(ref->lnum);
673
674 err = done_already(&done_tree, ref_lnum);
675 if (err < 0)
676 goto out_scan;
677 if (err != 1) {
678 err = add_node(c, buf, &write_lnum,
679 &offs, snod->node);
680 if (err)
681 goto out_scan;
682 }
683 break;
684 }
685 case UBIFS_CS_NODE:
686 if (!first)
687 break;
688 err = add_node(c, buf, &write_lnum, &offs,
689 snod->node);
690 if (err)
691 goto out_scan;
692 first = 0;
693 break;
694 }
695 }
696 ubifs_scan_destroy(sleb);
697 if (lnum == c->lhead_lnum)
698 break;
699 lnum = ubifs_next_log_lnum(c, lnum);
700 }
701 if (offs) {
702 int sz = ALIGN(offs, c->min_io_size);
703
704 ubifs_pad(c, buf + offs, sz - offs);
705 err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM);
706 if (err)
707 goto out_free;
708 offs = ALIGN(offs, c->min_io_size);
709 }
710 destroy_done_tree(&done_tree);
711 vfree(buf);
712 if (write_lnum == c->lhead_lnum) {
713 ubifs_err("log is too full");
714 return -EINVAL;
715 }
716 /* Unmap remaining LEBs */
717 lnum = write_lnum;
718 do {
719 lnum = ubifs_next_log_lnum(c, lnum);
720 err = ubifs_leb_unmap(c, lnum);
721 if (err)
722 return err;
723 } while (lnum != c->lhead_lnum);
724 c->lhead_lnum = write_lnum;
725 c->lhead_offs = offs;
726 dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
727 return 0;
728
729out_scan:
730 ubifs_scan_destroy(sleb);
731out_free:
732 destroy_done_tree(&done_tree);
733 vfree(buf);
734 return err;
735}
736
737#ifdef CONFIG_UBIFS_FS_DEBUG
738
739/**
740 * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
741 * @c: UBIFS file-system description object
742 *
743 * This function makes sure the amount of flash space used by closed buds
744 * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
745 * case of failure.
746 */
747static int dbg_check_bud_bytes(struct ubifs_info *c)
748{
749 int i, err = 0;
750 struct ubifs_bud *bud;
751 long long bud_bytes = 0;
752
753 if (!dbg_is_chk_gen(c))
754 return 0;
755
756 spin_lock(&c->buds_lock);
757 for (i = 0; i < c->jhead_cnt; i++)
758 list_for_each_entry(bud, &c->jheads[i].buds_list, list)
759 bud_bytes += c->leb_size - bud->start;
760
761 if (c->bud_bytes != bud_bytes) {
762 ubifs_err("bad bud_bytes %lld, calculated %lld",
763 c->bud_bytes, bud_bytes);
764 err = -EINVAL;
765 }
766 spin_unlock(&c->buds_lock);
767
768 return err;
769}
770
771#endif /* CONFIG_UBIFS_FS_DEBUG */
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
7 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11/*
12 * This file is a part of UBIFS journal implementation and contains various
13 * functions which manipulate the log. The log is a fixed area on the flash
14 * which does not contain any data but refers to buds. The log is a part of the
15 * journal.
16 */
17
18#include "ubifs.h"
19
20static int dbg_check_bud_bytes(struct ubifs_info *c);
21
22/**
23 * ubifs_search_bud - search bud LEB.
24 * @c: UBIFS file-system description object
25 * @lnum: logical eraseblock number to search
26 *
27 * This function searches bud LEB @lnum. Returns bud description object in case
28 * of success and %NULL if there is no bud with this LEB number.
29 */
30struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
31{
32 struct rb_node *p;
33 struct ubifs_bud *bud;
34
35 spin_lock(&c->buds_lock);
36 p = c->buds.rb_node;
37 while (p) {
38 bud = rb_entry(p, struct ubifs_bud, rb);
39 if (lnum < bud->lnum)
40 p = p->rb_left;
41 else if (lnum > bud->lnum)
42 p = p->rb_right;
43 else {
44 spin_unlock(&c->buds_lock);
45 return bud;
46 }
47 }
48 spin_unlock(&c->buds_lock);
49 return NULL;
50}
51
52/**
53 * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
54 * @c: UBIFS file-system description object
55 * @lnum: logical eraseblock number to search
56 *
57 * This functions returns the wbuf for @lnum or %NULL if there is not one.
58 */
59struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
60{
61 struct rb_node *p;
62 struct ubifs_bud *bud;
63 int jhead;
64
65 if (!c->jheads)
66 return NULL;
67
68 spin_lock(&c->buds_lock);
69 p = c->buds.rb_node;
70 while (p) {
71 bud = rb_entry(p, struct ubifs_bud, rb);
72 if (lnum < bud->lnum)
73 p = p->rb_left;
74 else if (lnum > bud->lnum)
75 p = p->rb_right;
76 else {
77 jhead = bud->jhead;
78 spin_unlock(&c->buds_lock);
79 return &c->jheads[jhead].wbuf;
80 }
81 }
82 spin_unlock(&c->buds_lock);
83 return NULL;
84}
85
86/**
87 * empty_log_bytes - calculate amount of empty space in the log.
88 * @c: UBIFS file-system description object
89 */
90static inline long long empty_log_bytes(const struct ubifs_info *c)
91{
92 long long h, t;
93
94 h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
95 t = (long long)c->ltail_lnum * c->leb_size;
96
97 if (h > t)
98 return c->log_bytes - h + t;
99 else if (h != t)
100 return t - h;
101 else if (c->lhead_lnum != c->ltail_lnum)
102 return 0;
103 else
104 return c->log_bytes;
105}
106
107/**
108 * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
109 * @c: UBIFS file-system description object
110 * @bud: the bud to add
111 */
112void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
113{
114 struct rb_node **p, *parent = NULL;
115 struct ubifs_bud *b;
116 struct ubifs_jhead *jhead;
117
118 spin_lock(&c->buds_lock);
119 p = &c->buds.rb_node;
120 while (*p) {
121 parent = *p;
122 b = rb_entry(parent, struct ubifs_bud, rb);
123 ubifs_assert(c, bud->lnum != b->lnum);
124 if (bud->lnum < b->lnum)
125 p = &(*p)->rb_left;
126 else
127 p = &(*p)->rb_right;
128 }
129
130 rb_link_node(&bud->rb, parent, p);
131 rb_insert_color(&bud->rb, &c->buds);
132 if (c->jheads) {
133 jhead = &c->jheads[bud->jhead];
134 list_add_tail(&bud->list, &jhead->buds_list);
135 } else
136 ubifs_assert(c, c->replaying && c->ro_mount);
137
138 /*
139 * Note, although this is a new bud, we anyway account this space now,
140 * before any data has been written to it, because this is about to
141 * guarantee fixed mount time, and this bud will anyway be read and
142 * scanned.
143 */
144 c->bud_bytes += c->leb_size - bud->start;
145
146 dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
147 bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
148 spin_unlock(&c->buds_lock);
149}
150
151/**
152 * ubifs_add_bud_to_log - add a new bud to the log.
153 * @c: UBIFS file-system description object
154 * @jhead: journal head the bud belongs to
155 * @lnum: LEB number of the bud
156 * @offs: starting offset of the bud
157 *
158 * This function writes a reference node for the new bud LEB @lnum to the log,
159 * and adds it to the buds trees. It also makes sure that log size does not
160 * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
161 * %-EAGAIN if commit is required, and a negative error code in case of
162 * failure.
163 */
164int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
165{
166 int err;
167 struct ubifs_bud *bud;
168 struct ubifs_ref_node *ref;
169
170 bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
171 if (!bud)
172 return -ENOMEM;
173 ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
174 if (!ref) {
175 kfree(bud);
176 return -ENOMEM;
177 }
178
179 mutex_lock(&c->log_mutex);
180 ubifs_assert(c, !c->ro_media && !c->ro_mount);
181 if (c->ro_error) {
182 err = -EROFS;
183 goto out_unlock;
184 }
185
186 /* Make sure we have enough space in the log */
187 if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
188 dbg_log("not enough log space - %lld, required %d",
189 empty_log_bytes(c), c->min_log_bytes);
190 ubifs_commit_required(c);
191 err = -EAGAIN;
192 goto out_unlock;
193 }
194
195 /*
196 * Make sure the amount of space in buds will not exceed the
197 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
198 * limits.
199 *
200 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
201 * because we are holding @c->log_mutex. All @c->bud_bytes take place
202 * when both @c->log_mutex and @c->bud_bytes are locked.
203 */
204 if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
205 dbg_log("bud bytes %lld (%lld max), require commit",
206 c->bud_bytes, c->max_bud_bytes);
207 ubifs_commit_required(c);
208 err = -EAGAIN;
209 goto out_unlock;
210 }
211
212 /*
213 * If the journal is full enough - start background commit. Note, it is
214 * OK to read 'c->cmt_state' without spinlock because integer reads
215 * are atomic in the kernel.
216 */
217 if (c->bud_bytes >= c->bg_bud_bytes &&
218 c->cmt_state == COMMIT_RESTING) {
219 dbg_log("bud bytes %lld (%lld max), initiate BG commit",
220 c->bud_bytes, c->max_bud_bytes);
221 ubifs_request_bg_commit(c);
222 }
223
224 bud->lnum = lnum;
225 bud->start = offs;
226 bud->jhead = jhead;
227 bud->log_hash = NULL;
228
229 ref->ch.node_type = UBIFS_REF_NODE;
230 ref->lnum = cpu_to_le32(bud->lnum);
231 ref->offs = cpu_to_le32(bud->start);
232 ref->jhead = cpu_to_le32(jhead);
233
234 if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
235 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
236 ubifs_assert(c, c->lhead_lnum != c->ltail_lnum);
237 c->lhead_offs = 0;
238 }
239
240 if (c->lhead_offs == 0) {
241 /* Must ensure next log LEB has been unmapped */
242 err = ubifs_leb_unmap(c, c->lhead_lnum);
243 if (err)
244 goto out_unlock;
245 }
246
247 if (bud->start == 0) {
248 /*
249 * Before writing the LEB reference which refers an empty LEB
250 * to the log, we have to make sure it is mapped, because
251 * otherwise we'd risk to refer an LEB with garbage in case of
252 * an unclean reboot, because the target LEB might have been
253 * unmapped, but not yet physically erased.
254 */
255 err = ubifs_leb_map(c, bud->lnum);
256 if (err)
257 goto out_unlock;
258 }
259
260 dbg_log("write ref LEB %d:%d",
261 c->lhead_lnum, c->lhead_offs);
262 err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
263 c->lhead_offs);
264 if (err)
265 goto out_unlock;
266
267 err = ubifs_shash_update(c, c->log_hash, ref, UBIFS_REF_NODE_SZ);
268 if (err)
269 goto out_unlock;
270
271 err = ubifs_shash_copy_state(c, c->log_hash, c->jheads[jhead].log_hash);
272 if (err)
273 goto out_unlock;
274
275 c->lhead_offs += c->ref_node_alsz;
276
277 ubifs_add_bud(c, bud);
278
279 mutex_unlock(&c->log_mutex);
280 kfree(ref);
281 return 0;
282
283out_unlock:
284 mutex_unlock(&c->log_mutex);
285 kfree(ref);
286 kfree(bud);
287 return err;
288}
289
290/**
291 * remove_buds - remove used buds.
292 * @c: UBIFS file-system description object
293 *
294 * This function removes use buds from the buds tree. It does not remove the
295 * buds which are pointed to by journal heads.
296 */
297static void remove_buds(struct ubifs_info *c)
298{
299 struct rb_node *p;
300
301 ubifs_assert(c, list_empty(&c->old_buds));
302 c->cmt_bud_bytes = 0;
303 spin_lock(&c->buds_lock);
304 p = rb_first(&c->buds);
305 while (p) {
306 struct rb_node *p1 = p;
307 struct ubifs_bud *bud;
308 struct ubifs_wbuf *wbuf;
309
310 p = rb_next(p);
311 bud = rb_entry(p1, struct ubifs_bud, rb);
312 wbuf = &c->jheads[bud->jhead].wbuf;
313
314 if (wbuf->lnum == bud->lnum) {
315 /*
316 * Do not remove buds which are pointed to by journal
317 * heads (non-closed buds).
318 */
319 c->cmt_bud_bytes += wbuf->offs - bud->start;
320 dbg_log("preserve %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
321 bud->lnum, bud->start, dbg_jhead(bud->jhead),
322 wbuf->offs - bud->start, c->cmt_bud_bytes);
323 bud->start = wbuf->offs;
324 } else {
325 c->cmt_bud_bytes += c->leb_size - bud->start;
326 dbg_log("remove %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld",
327 bud->lnum, bud->start, dbg_jhead(bud->jhead),
328 c->leb_size - bud->start, c->cmt_bud_bytes);
329 rb_erase(p1, &c->buds);
330 /*
331 * If the commit does not finish, the recovery will need
332 * to replay the journal, in which case the old buds
333 * must be unchanged. Do not release them until post
334 * commit i.e. do not allow them to be garbage
335 * collected.
336 */
337 list_move(&bud->list, &c->old_buds);
338 }
339 }
340 spin_unlock(&c->buds_lock);
341}
342
343/**
344 * ubifs_log_start_commit - start commit.
345 * @c: UBIFS file-system description object
346 * @ltail_lnum: return new log tail LEB number
347 *
348 * The commit operation starts with writing "commit start" node to the log and
349 * reference nodes for all journal heads which will define new journal after
350 * the commit has been finished. The commit start and reference nodes are
351 * written in one go to the nearest empty log LEB (hence, when commit is
352 * finished UBIFS may safely unmap all the previous log LEBs). This function
353 * returns zero in case of success and a negative error code in case of
354 * failure.
355 */
356int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
357{
358 void *buf;
359 struct ubifs_cs_node *cs;
360 struct ubifs_ref_node *ref;
361 int err, i, max_len, len;
362
363 err = dbg_check_bud_bytes(c);
364 if (err)
365 return err;
366
367 max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
368 max_len = ALIGN(max_len, c->min_io_size);
369 buf = cs = kmalloc(max_len, GFP_NOFS);
370 if (!buf)
371 return -ENOMEM;
372
373 cs->ch.node_type = UBIFS_CS_NODE;
374 cs->cmt_no = cpu_to_le64(c->cmt_no);
375 ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
376
377 err = ubifs_shash_init(c, c->log_hash);
378 if (err)
379 goto out;
380
381 err = ubifs_shash_update(c, c->log_hash, cs, UBIFS_CS_NODE_SZ);
382 if (err < 0)
383 goto out;
384
385 /*
386 * Note, we do not lock 'c->log_mutex' because this is the commit start
387 * phase and we are exclusively using the log. And we do not lock
388 * write-buffer because nobody can write to the file-system at this
389 * phase.
390 */
391
392 len = UBIFS_CS_NODE_SZ;
393 for (i = 0; i < c->jhead_cnt; i++) {
394 int lnum = c->jheads[i].wbuf.lnum;
395 int offs = c->jheads[i].wbuf.offs;
396
397 if (lnum == -1 || offs == c->leb_size)
398 continue;
399
400 dbg_log("add ref to LEB %d:%d for jhead %s",
401 lnum, offs, dbg_jhead(i));
402 ref = buf + len;
403 ref->ch.node_type = UBIFS_REF_NODE;
404 ref->lnum = cpu_to_le32(lnum);
405 ref->offs = cpu_to_le32(offs);
406 ref->jhead = cpu_to_le32(i);
407
408 ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
409 len += UBIFS_REF_NODE_SZ;
410
411 err = ubifs_shash_update(c, c->log_hash, ref,
412 UBIFS_REF_NODE_SZ);
413 if (err)
414 goto out;
415 ubifs_shash_copy_state(c, c->log_hash, c->jheads[i].log_hash);
416 }
417
418 ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
419
420 /* Switch to the next log LEB */
421 if (c->lhead_offs) {
422 c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
423 ubifs_assert(c, c->lhead_lnum != c->ltail_lnum);
424 c->lhead_offs = 0;
425 }
426
427 /* Must ensure next LEB has been unmapped */
428 err = ubifs_leb_unmap(c, c->lhead_lnum);
429 if (err)
430 goto out;
431
432 len = ALIGN(len, c->min_io_size);
433 dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
434 err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len);
435 if (err)
436 goto out;
437
438 *ltail_lnum = c->lhead_lnum;
439
440 c->lhead_offs += len;
441 ubifs_assert(c, c->lhead_offs < c->leb_size);
442
443 remove_buds(c);
444
445 /*
446 * We have started the commit and now users may use the rest of the log
447 * for new writes.
448 */
449 c->min_log_bytes = 0;
450
451out:
452 kfree(buf);
453 return err;
454}
455
456/**
457 * ubifs_log_end_commit - end commit.
458 * @c: UBIFS file-system description object
459 * @ltail_lnum: new log tail LEB number
460 *
461 * This function is called on when the commit operation was finished. It
462 * moves log tail to new position and updates the master node so that it stores
463 * the new log tail LEB number. Returns zero in case of success and a negative
464 * error code in case of failure.
465 */
466int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
467{
468 int err;
469
470 /*
471 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
472 * writes during commit. Its only short "commit" start phase when
473 * writers are blocked.
474 */
475 mutex_lock(&c->log_mutex);
476
477 dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
478 c->ltail_lnum, ltail_lnum);
479
480 c->ltail_lnum = ltail_lnum;
481 /*
482 * The commit is finished and from now on it must be guaranteed that
483 * there is always enough space for the next commit.
484 */
485 c->min_log_bytes = c->leb_size;
486
487 spin_lock(&c->buds_lock);
488 c->bud_bytes -= c->cmt_bud_bytes;
489 spin_unlock(&c->buds_lock);
490
491 err = dbg_check_bud_bytes(c);
492 if (err)
493 goto out;
494
495 err = ubifs_write_master(c);
496
497out:
498 mutex_unlock(&c->log_mutex);
499 return err;
500}
501
502/**
503 * ubifs_log_post_commit - things to do after commit is completed.
504 * @c: UBIFS file-system description object
505 * @old_ltail_lnum: old log tail LEB number
506 *
507 * Release buds only after commit is completed, because they must be unchanged
508 * if recovery is needed.
509 *
510 * Unmap log LEBs only after commit is completed, because they may be needed for
511 * recovery.
512 *
513 * This function returns %0 on success and a negative error code on failure.
514 */
515int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
516{
517 int lnum, err = 0;
518
519 while (!list_empty(&c->old_buds)) {
520 struct ubifs_bud *bud;
521
522 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
523 err = ubifs_return_leb(c, bud->lnum);
524 if (err)
525 return err;
526 list_del(&bud->list);
527 kfree(bud->log_hash);
528 kfree(bud);
529 }
530 mutex_lock(&c->log_mutex);
531 for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
532 lnum = ubifs_next_log_lnum(c, lnum)) {
533 dbg_log("unmap log LEB %d", lnum);
534 err = ubifs_leb_unmap(c, lnum);
535 if (err)
536 goto out;
537 }
538out:
539 mutex_unlock(&c->log_mutex);
540 return err;
541}
542
543/**
544 * struct done_ref - references that have been done.
545 * @rb: rb-tree node
546 * @lnum: LEB number
547 */
548struct done_ref {
549 struct rb_node rb;
550 int lnum;
551};
552
553/**
554 * done_already - determine if a reference has been done already.
555 * @done_tree: rb-tree to store references that have been done
556 * @lnum: LEB number of reference
557 *
558 * This function returns %1 if the reference has been done, %0 if not, otherwise
559 * a negative error code is returned.
560 */
561static int done_already(struct rb_root *done_tree, int lnum)
562{
563 struct rb_node **p = &done_tree->rb_node, *parent = NULL;
564 struct done_ref *dr;
565
566 while (*p) {
567 parent = *p;
568 dr = rb_entry(parent, struct done_ref, rb);
569 if (lnum < dr->lnum)
570 p = &(*p)->rb_left;
571 else if (lnum > dr->lnum)
572 p = &(*p)->rb_right;
573 else
574 return 1;
575 }
576
577 dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
578 if (!dr)
579 return -ENOMEM;
580
581 dr->lnum = lnum;
582
583 rb_link_node(&dr->rb, parent, p);
584 rb_insert_color(&dr->rb, done_tree);
585
586 return 0;
587}
588
589/**
590 * destroy_done_tree - destroy the done tree.
591 * @done_tree: done tree to destroy
592 */
593static void destroy_done_tree(struct rb_root *done_tree)
594{
595 struct done_ref *dr, *n;
596
597 rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb)
598 kfree(dr);
599}
600
601/**
602 * add_node - add a node to the consolidated log.
603 * @c: UBIFS file-system description object
604 * @buf: buffer to which to add
605 * @lnum: LEB number to which to write is passed and returned here
606 * @offs: offset to where to write is passed and returned here
607 * @node: node to add
608 *
609 * This function returns %0 on success and a negative error code on failure.
610 */
611static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
612 void *node)
613{
614 struct ubifs_ch *ch = node;
615 int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
616
617 if (len > remains) {
618 int sz = ALIGN(*offs, c->min_io_size), err;
619
620 ubifs_pad(c, buf + *offs, sz - *offs);
621 err = ubifs_leb_change(c, *lnum, buf, sz);
622 if (err)
623 return err;
624 *lnum = ubifs_next_log_lnum(c, *lnum);
625 *offs = 0;
626 }
627 memcpy(buf + *offs, node, len);
628 *offs += ALIGN(len, 8);
629 return 0;
630}
631
632/**
633 * ubifs_consolidate_log - consolidate the log.
634 * @c: UBIFS file-system description object
635 *
636 * Repeated failed commits could cause the log to be full, but at least 1 LEB is
637 * needed for commit. This function rewrites the reference nodes in the log
638 * omitting duplicates, and failed CS nodes, and leaving no gaps.
639 *
640 * This function returns %0 on success and a negative error code on failure.
641 */
642int ubifs_consolidate_log(struct ubifs_info *c)
643{
644 struct ubifs_scan_leb *sleb;
645 struct ubifs_scan_node *snod;
646 struct rb_root done_tree = RB_ROOT;
647 int lnum, err, first = 1, write_lnum, offs = 0;
648 void *buf;
649
650 dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
651 c->lhead_lnum);
652 buf = vmalloc(c->leb_size);
653 if (!buf)
654 return -ENOMEM;
655 lnum = c->ltail_lnum;
656 write_lnum = lnum;
657 while (1) {
658 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
659 if (IS_ERR(sleb)) {
660 err = PTR_ERR(sleb);
661 goto out_free;
662 }
663 list_for_each_entry(snod, &sleb->nodes, list) {
664 switch (snod->type) {
665 case UBIFS_REF_NODE: {
666 struct ubifs_ref_node *ref = snod->node;
667 int ref_lnum = le32_to_cpu(ref->lnum);
668
669 err = done_already(&done_tree, ref_lnum);
670 if (err < 0)
671 goto out_scan;
672 if (err != 1) {
673 err = add_node(c, buf, &write_lnum,
674 &offs, snod->node);
675 if (err)
676 goto out_scan;
677 }
678 break;
679 }
680 case UBIFS_CS_NODE:
681 if (!first)
682 break;
683 err = add_node(c, buf, &write_lnum, &offs,
684 snod->node);
685 if (err)
686 goto out_scan;
687 first = 0;
688 break;
689 }
690 }
691 ubifs_scan_destroy(sleb);
692 if (lnum == c->lhead_lnum)
693 break;
694 lnum = ubifs_next_log_lnum(c, lnum);
695 }
696 if (offs) {
697 int sz = ALIGN(offs, c->min_io_size);
698
699 ubifs_pad(c, buf + offs, sz - offs);
700 err = ubifs_leb_change(c, write_lnum, buf, sz);
701 if (err)
702 goto out_free;
703 offs = ALIGN(offs, c->min_io_size);
704 }
705 destroy_done_tree(&done_tree);
706 vfree(buf);
707 if (write_lnum == c->lhead_lnum) {
708 ubifs_err(c, "log is too full");
709 return -EINVAL;
710 }
711 /* Unmap remaining LEBs */
712 lnum = write_lnum;
713 do {
714 lnum = ubifs_next_log_lnum(c, lnum);
715 err = ubifs_leb_unmap(c, lnum);
716 if (err)
717 return err;
718 } while (lnum != c->lhead_lnum);
719 c->lhead_lnum = write_lnum;
720 c->lhead_offs = offs;
721 dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
722 return 0;
723
724out_scan:
725 ubifs_scan_destroy(sleb);
726out_free:
727 destroy_done_tree(&done_tree);
728 vfree(buf);
729 return err;
730}
731
732/**
733 * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
734 * @c: UBIFS file-system description object
735 *
736 * This function makes sure the amount of flash space used by closed buds
737 * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
738 * case of failure.
739 */
740static int dbg_check_bud_bytes(struct ubifs_info *c)
741{
742 int i, err = 0;
743 struct ubifs_bud *bud;
744 long long bud_bytes = 0;
745
746 if (!dbg_is_chk_gen(c))
747 return 0;
748
749 spin_lock(&c->buds_lock);
750 for (i = 0; i < c->jhead_cnt; i++)
751 list_for_each_entry(bud, &c->jheads[i].buds_list, list)
752 bud_bytes += c->leb_size - bud->start;
753
754 if (c->bud_bytes != bud_bytes) {
755 ubifs_err(c, "bad bud_bytes %lld, calculated %lld",
756 c->bud_bytes, bud_bytes);
757 err = -EINVAL;
758 }
759 spin_unlock(&c->buds_lock);
760
761 return err;
762}