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1/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file contains journal replay code. It runs when the file-system is being
25 * mounted and requires no locking.
26 *
27 * The larger is the journal, the longer it takes to scan it, so the longer it
28 * takes to mount UBIFS. This is why the journal has limited size which may be
29 * changed depending on the system requirements. But a larger journal gives
30 * faster I/O speed because it writes the index less frequently. So this is a
31 * trade-off. Also, the journal is indexed by the in-memory index (TNC), so the
32 * larger is the journal, the more memory its index may consume.
33 */
34
35#include "ubifs.h"
36#include <linux/list_sort.h>
37
38/**
39 * struct replay_entry - replay list entry.
40 * @lnum: logical eraseblock number of the node
41 * @offs: node offset
42 * @len: node length
43 * @deletion: non-zero if this entry corresponds to a node deletion
44 * @sqnum: node sequence number
45 * @list: links the replay list
46 * @key: node key
47 * @nm: directory entry name
48 * @old_size: truncation old size
49 * @new_size: truncation new size
50 *
51 * The replay process first scans all buds and builds the replay list, then
52 * sorts the replay list in nodes sequence number order, and then inserts all
53 * the replay entries to the TNC.
54 */
55struct replay_entry {
56 int lnum;
57 int offs;
58 int len;
59 unsigned int deletion:1;
60 unsigned long long sqnum;
61 struct list_head list;
62 union ubifs_key key;
63 union {
64 struct fscrypt_name nm;
65 struct {
66 loff_t old_size;
67 loff_t new_size;
68 };
69 };
70};
71
72/**
73 * struct bud_entry - entry in the list of buds to replay.
74 * @list: next bud in the list
75 * @bud: bud description object
76 * @sqnum: reference node sequence number
77 * @free: free bytes in the bud
78 * @dirty: dirty bytes in the bud
79 */
80struct bud_entry {
81 struct list_head list;
82 struct ubifs_bud *bud;
83 unsigned long long sqnum;
84 int free;
85 int dirty;
86};
87
88/**
89 * set_bud_lprops - set free and dirty space used by a bud.
90 * @c: UBIFS file-system description object
91 * @b: bud entry which describes the bud
92 *
93 * This function makes sure the LEB properties of bud @b are set correctly
94 * after the replay. Returns zero in case of success and a negative error code
95 * in case of failure.
96 */
97static int set_bud_lprops(struct ubifs_info *c, struct bud_entry *b)
98{
99 const struct ubifs_lprops *lp;
100 int err = 0, dirty;
101
102 ubifs_get_lprops(c);
103
104 lp = ubifs_lpt_lookup_dirty(c, b->bud->lnum);
105 if (IS_ERR(lp)) {
106 err = PTR_ERR(lp);
107 goto out;
108 }
109
110 dirty = lp->dirty;
111 if (b->bud->start == 0 && (lp->free != c->leb_size || lp->dirty != 0)) {
112 /*
113 * The LEB was added to the journal with a starting offset of
114 * zero which means the LEB must have been empty. The LEB
115 * property values should be @lp->free == @c->leb_size and
116 * @lp->dirty == 0, but that is not the case. The reason is that
117 * the LEB had been garbage collected before it became the bud,
118 * and there was not commit inbetween. The garbage collector
119 * resets the free and dirty space without recording it
120 * anywhere except lprops, so if there was no commit then
121 * lprops does not have that information.
122 *
123 * We do not need to adjust free space because the scan has told
124 * us the exact value which is recorded in the replay entry as
125 * @b->free.
126 *
127 * However we do need to subtract from the dirty space the
128 * amount of space that the garbage collector reclaimed, which
129 * is the whole LEB minus the amount of space that was free.
130 */
131 dbg_mnt("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
132 lp->free, lp->dirty);
133 dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
134 lp->free, lp->dirty);
135 dirty -= c->leb_size - lp->free;
136 /*
137 * If the replay order was perfect the dirty space would now be
138 * zero. The order is not perfect because the journal heads
139 * race with each other. This is not a problem but is does mean
140 * that the dirty space may temporarily exceed c->leb_size
141 * during the replay.
142 */
143 if (dirty != 0)
144 dbg_mnt("LEB %d lp: %d free %d dirty replay: %d free %d dirty",
145 b->bud->lnum, lp->free, lp->dirty, b->free,
146 b->dirty);
147 }
148 lp = ubifs_change_lp(c, lp, b->free, dirty + b->dirty,
149 lp->flags | LPROPS_TAKEN, 0);
150 if (IS_ERR(lp)) {
151 err = PTR_ERR(lp);
152 goto out;
153 }
154
155 /* Make sure the journal head points to the latest bud */
156 err = ubifs_wbuf_seek_nolock(&c->jheads[b->bud->jhead].wbuf,
157 b->bud->lnum, c->leb_size - b->free);
158
159out:
160 ubifs_release_lprops(c);
161 return err;
162}
163
164/**
165 * set_buds_lprops - set free and dirty space for all replayed buds.
166 * @c: UBIFS file-system description object
167 *
168 * This function sets LEB properties for all replayed buds. Returns zero in
169 * case of success and a negative error code in case of failure.
170 */
171static int set_buds_lprops(struct ubifs_info *c)
172{
173 struct bud_entry *b;
174 int err;
175
176 list_for_each_entry(b, &c->replay_buds, list) {
177 err = set_bud_lprops(c, b);
178 if (err)
179 return err;
180 }
181
182 return 0;
183}
184
185/**
186 * trun_remove_range - apply a replay entry for a truncation to the TNC.
187 * @c: UBIFS file-system description object
188 * @r: replay entry of truncation
189 */
190static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
191{
192 unsigned min_blk, max_blk;
193 union ubifs_key min_key, max_key;
194 ino_t ino;
195
196 min_blk = r->new_size / UBIFS_BLOCK_SIZE;
197 if (r->new_size & (UBIFS_BLOCK_SIZE - 1))
198 min_blk += 1;
199
200 max_blk = r->old_size / UBIFS_BLOCK_SIZE;
201 if ((r->old_size & (UBIFS_BLOCK_SIZE - 1)) == 0)
202 max_blk -= 1;
203
204 ino = key_inum(c, &r->key);
205
206 data_key_init(c, &min_key, ino, min_blk);
207 data_key_init(c, &max_key, ino, max_blk);
208
209 return ubifs_tnc_remove_range(c, &min_key, &max_key);
210}
211
212/**
213 * apply_replay_entry - apply a replay entry to the TNC.
214 * @c: UBIFS file-system description object
215 * @r: replay entry to apply
216 *
217 * Apply a replay entry to the TNC.
218 */
219static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
220{
221 int err;
222
223 dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ",
224 r->lnum, r->offs, r->len, r->deletion, r->sqnum);
225
226 /* Set c->replay_sqnum to help deal with dangling branches. */
227 c->replay_sqnum = r->sqnum;
228
229 if (is_hash_key(c, &r->key)) {
230 if (r->deletion)
231 err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
232 else
233 err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
234 r->len, &r->nm);
235 } else {
236 if (r->deletion)
237 switch (key_type(c, &r->key)) {
238 case UBIFS_INO_KEY:
239 {
240 ino_t inum = key_inum(c, &r->key);
241
242 err = ubifs_tnc_remove_ino(c, inum);
243 break;
244 }
245 case UBIFS_TRUN_KEY:
246 err = trun_remove_range(c, r);
247 break;
248 default:
249 err = ubifs_tnc_remove(c, &r->key);
250 break;
251 }
252 else
253 err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
254 r->len);
255 if (err)
256 return err;
257
258 if (c->need_recovery)
259 err = ubifs_recover_size_accum(c, &r->key, r->deletion,
260 r->new_size);
261 }
262
263 return err;
264}
265
266/**
267 * replay_entries_cmp - compare 2 replay entries.
268 * @priv: UBIFS file-system description object
269 * @a: first replay entry
270 * @b: second replay entry
271 *
272 * This is a comparios function for 'list_sort()' which compares 2 replay
273 * entries @a and @b by comparing their sequence numer. Returns %1 if @a has
274 * greater sequence number and %-1 otherwise.
275 */
276static int replay_entries_cmp(void *priv, struct list_head *a,
277 struct list_head *b)
278{
279 struct replay_entry *ra, *rb;
280
281 cond_resched();
282 if (a == b)
283 return 0;
284
285 ra = list_entry(a, struct replay_entry, list);
286 rb = list_entry(b, struct replay_entry, list);
287 ubifs_assert(ra->sqnum != rb->sqnum);
288 if (ra->sqnum > rb->sqnum)
289 return 1;
290 return -1;
291}
292
293/**
294 * apply_replay_list - apply the replay list to the TNC.
295 * @c: UBIFS file-system description object
296 *
297 * Apply all entries in the replay list to the TNC. Returns zero in case of
298 * success and a negative error code in case of failure.
299 */
300static int apply_replay_list(struct ubifs_info *c)
301{
302 struct replay_entry *r;
303 int err;
304
305 list_sort(c, &c->replay_list, &replay_entries_cmp);
306
307 list_for_each_entry(r, &c->replay_list, list) {
308 cond_resched();
309
310 err = apply_replay_entry(c, r);
311 if (err)
312 return err;
313 }
314
315 return 0;
316}
317
318/**
319 * destroy_replay_list - destroy the replay.
320 * @c: UBIFS file-system description object
321 *
322 * Destroy the replay list.
323 */
324static void destroy_replay_list(struct ubifs_info *c)
325{
326 struct replay_entry *r, *tmp;
327
328 list_for_each_entry_safe(r, tmp, &c->replay_list, list) {
329 if (is_hash_key(c, &r->key))
330 kfree(fname_name(&r->nm));
331 list_del(&r->list);
332 kfree(r);
333 }
334}
335
336/**
337 * insert_node - insert a node to the replay list
338 * @c: UBIFS file-system description object
339 * @lnum: node logical eraseblock number
340 * @offs: node offset
341 * @len: node length
342 * @key: node key
343 * @sqnum: sequence number
344 * @deletion: non-zero if this is a deletion
345 * @used: number of bytes in use in a LEB
346 * @old_size: truncation old size
347 * @new_size: truncation new size
348 *
349 * This function inserts a scanned non-direntry node to the replay list. The
350 * replay list contains @struct replay_entry elements, and we sort this list in
351 * sequence number order before applying it. The replay list is applied at the
352 * very end of the replay process. Since the list is sorted in sequence number
353 * order, the older modifications are applied first. This function returns zero
354 * in case of success and a negative error code in case of failure.
355 */
356static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
357 union ubifs_key *key, unsigned long long sqnum,
358 int deletion, int *used, loff_t old_size,
359 loff_t new_size)
360{
361 struct replay_entry *r;
362
363 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
364
365 if (key_inum(c, key) >= c->highest_inum)
366 c->highest_inum = key_inum(c, key);
367
368 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
369 if (!r)
370 return -ENOMEM;
371
372 if (!deletion)
373 *used += ALIGN(len, 8);
374 r->lnum = lnum;
375 r->offs = offs;
376 r->len = len;
377 r->deletion = !!deletion;
378 r->sqnum = sqnum;
379 key_copy(c, key, &r->key);
380 r->old_size = old_size;
381 r->new_size = new_size;
382
383 list_add_tail(&r->list, &c->replay_list);
384 return 0;
385}
386
387/**
388 * insert_dent - insert a directory entry node into the replay list.
389 * @c: UBIFS file-system description object
390 * @lnum: node logical eraseblock number
391 * @offs: node offset
392 * @len: node length
393 * @key: node key
394 * @name: directory entry name
395 * @nlen: directory entry name length
396 * @sqnum: sequence number
397 * @deletion: non-zero if this is a deletion
398 * @used: number of bytes in use in a LEB
399 *
400 * This function inserts a scanned directory entry node or an extended
401 * attribute entry to the replay list. Returns zero in case of success and a
402 * negative error code in case of failure.
403 */
404static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
405 union ubifs_key *key, const char *name, int nlen,
406 unsigned long long sqnum, int deletion, int *used)
407{
408 struct replay_entry *r;
409 char *nbuf;
410
411 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
412 if (key_inum(c, key) >= c->highest_inum)
413 c->highest_inum = key_inum(c, key);
414
415 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
416 if (!r)
417 return -ENOMEM;
418
419 nbuf = kmalloc(nlen + 1, GFP_KERNEL);
420 if (!nbuf) {
421 kfree(r);
422 return -ENOMEM;
423 }
424
425 if (!deletion)
426 *used += ALIGN(len, 8);
427 r->lnum = lnum;
428 r->offs = offs;
429 r->len = len;
430 r->deletion = !!deletion;
431 r->sqnum = sqnum;
432 key_copy(c, key, &r->key);
433 fname_len(&r->nm) = nlen;
434 memcpy(nbuf, name, nlen);
435 nbuf[nlen] = '\0';
436 fname_name(&r->nm) = nbuf;
437
438 list_add_tail(&r->list, &c->replay_list);
439 return 0;
440}
441
442/**
443 * ubifs_validate_entry - validate directory or extended attribute entry node.
444 * @c: UBIFS file-system description object
445 * @dent: the node to validate
446 *
447 * This function validates directory or extended attribute entry node @dent.
448 * Returns zero if the node is all right and a %-EINVAL if not.
449 */
450int ubifs_validate_entry(struct ubifs_info *c,
451 const struct ubifs_dent_node *dent)
452{
453 int key_type = key_type_flash(c, dent->key);
454 int nlen = le16_to_cpu(dent->nlen);
455
456 if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
457 dent->type >= UBIFS_ITYPES_CNT ||
458 nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
459 (key_type == UBIFS_XENT_KEY && strnlen(dent->name, nlen) != nlen) ||
460 le64_to_cpu(dent->inum) > MAX_INUM) {
461 ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ?
462 "directory entry" : "extended attribute entry");
463 return -EINVAL;
464 }
465
466 if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
467 ubifs_err(c, "bad key type %d", key_type);
468 return -EINVAL;
469 }
470
471 return 0;
472}
473
474/**
475 * is_last_bud - check if the bud is the last in the journal head.
476 * @c: UBIFS file-system description object
477 * @bud: bud description object
478 *
479 * This function checks if bud @bud is the last bud in its journal head. This
480 * information is then used by 'replay_bud()' to decide whether the bud can
481 * have corruptions or not. Indeed, only last buds can be corrupted by power
482 * cuts. Returns %1 if this is the last bud, and %0 if not.
483 */
484static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
485{
486 struct ubifs_jhead *jh = &c->jheads[bud->jhead];
487 struct ubifs_bud *next;
488 uint32_t data;
489 int err;
490
491 if (list_is_last(&bud->list, &jh->buds_list))
492 return 1;
493
494 /*
495 * The following is a quirk to make sure we work correctly with UBIFS
496 * images used with older UBIFS.
497 *
498 * Normally, the last bud will be the last in the journal head's list
499 * of bud. However, there is one exception if the UBIFS image belongs
500 * to older UBIFS. This is fairly unlikely: one would need to use old
501 * UBIFS, then have a power cut exactly at the right point, and then
502 * try to mount this image with new UBIFS.
503 *
504 * The exception is: it is possible to have 2 buds A and B, A goes
505 * before B, and B is the last, bud B is contains no data, and bud A is
506 * corrupted at the end. The reason is that in older versions when the
507 * journal code switched the next bud (from A to B), it first added a
508 * log reference node for the new bud (B), and only after this it
509 * synchronized the write-buffer of current bud (A). But later this was
510 * changed and UBIFS started to always synchronize the write-buffer of
511 * the bud (A) before writing the log reference for the new bud (B).
512 *
513 * But because older UBIFS always synchronized A's write-buffer before
514 * writing to B, we can recognize this exceptional situation but
515 * checking the contents of bud B - if it is empty, then A can be
516 * treated as the last and we can recover it.
517 *
518 * TODO: remove this piece of code in a couple of years (today it is
519 * 16.05.2011).
520 */
521 next = list_entry(bud->list.next, struct ubifs_bud, list);
522 if (!list_is_last(&next->list, &jh->buds_list))
523 return 0;
524
525 err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1);
526 if (err)
527 return 0;
528
529 return data == 0xFFFFFFFF;
530}
531
532/**
533 * replay_bud - replay a bud logical eraseblock.
534 * @c: UBIFS file-system description object
535 * @b: bud entry which describes the bud
536 *
537 * This function replays bud @bud, recovers it if needed, and adds all nodes
538 * from this bud to the replay list. Returns zero in case of success and a
539 * negative error code in case of failure.
540 */
541static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
542{
543 int is_last = is_last_bud(c, b->bud);
544 int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start;
545 struct ubifs_scan_leb *sleb;
546 struct ubifs_scan_node *snod;
547
548 dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d",
549 lnum, b->bud->jhead, offs, is_last);
550
551 if (c->need_recovery && is_last)
552 /*
553 * Recover only last LEBs in the journal heads, because power
554 * cuts may cause corruptions only in these LEBs, because only
555 * these LEBs could possibly be written to at the power cut
556 * time.
557 */
558 sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead);
559 else
560 sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0);
561 if (IS_ERR(sleb))
562 return PTR_ERR(sleb);
563
564 /*
565 * The bud does not have to start from offset zero - the beginning of
566 * the 'lnum' LEB may contain previously committed data. One of the
567 * things we have to do in replay is to correctly update lprops with
568 * newer information about this LEB.
569 *
570 * At this point lprops thinks that this LEB has 'c->leb_size - offs'
571 * bytes of free space because it only contain information about
572 * committed data.
573 *
574 * But we know that real amount of free space is 'c->leb_size -
575 * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
576 * 'sleb->endpt' is used by bud data. We have to correctly calculate
577 * how much of these data are dirty and update lprops with this
578 * information.
579 *
580 * The dirt in that LEB region is comprised of padding nodes, deletion
581 * nodes, truncation nodes and nodes which are obsoleted by subsequent
582 * nodes in this LEB. So instead of calculating clean space, we
583 * calculate used space ('used' variable).
584 */
585
586 list_for_each_entry(snod, &sleb->nodes, list) {
587 int deletion = 0;
588
589 cond_resched();
590
591 if (snod->sqnum >= SQNUM_WATERMARK) {
592 ubifs_err(c, "file system's life ended");
593 goto out_dump;
594 }
595
596 if (snod->sqnum > c->max_sqnum)
597 c->max_sqnum = snod->sqnum;
598
599 switch (snod->type) {
600 case UBIFS_INO_NODE:
601 {
602 struct ubifs_ino_node *ino = snod->node;
603 loff_t new_size = le64_to_cpu(ino->size);
604
605 if (le32_to_cpu(ino->nlink) == 0)
606 deletion = 1;
607 err = insert_node(c, lnum, snod->offs, snod->len,
608 &snod->key, snod->sqnum, deletion,
609 &used, 0, new_size);
610 break;
611 }
612 case UBIFS_DATA_NODE:
613 {
614 struct ubifs_data_node *dn = snod->node;
615 loff_t new_size = le32_to_cpu(dn->size) +
616 key_block(c, &snod->key) *
617 UBIFS_BLOCK_SIZE;
618
619 err = insert_node(c, lnum, snod->offs, snod->len,
620 &snod->key, snod->sqnum, deletion,
621 &used, 0, new_size);
622 break;
623 }
624 case UBIFS_DENT_NODE:
625 case UBIFS_XENT_NODE:
626 {
627 struct ubifs_dent_node *dent = snod->node;
628
629 err = ubifs_validate_entry(c, dent);
630 if (err)
631 goto out_dump;
632
633 err = insert_dent(c, lnum, snod->offs, snod->len,
634 &snod->key, dent->name,
635 le16_to_cpu(dent->nlen), snod->sqnum,
636 !le64_to_cpu(dent->inum), &used);
637 break;
638 }
639 case UBIFS_TRUN_NODE:
640 {
641 struct ubifs_trun_node *trun = snod->node;
642 loff_t old_size = le64_to_cpu(trun->old_size);
643 loff_t new_size = le64_to_cpu(trun->new_size);
644 union ubifs_key key;
645
646 /* Validate truncation node */
647 if (old_size < 0 || old_size > c->max_inode_sz ||
648 new_size < 0 || new_size > c->max_inode_sz ||
649 old_size <= new_size) {
650 ubifs_err(c, "bad truncation node");
651 goto out_dump;
652 }
653
654 /*
655 * Create a fake truncation key just to use the same
656 * functions which expect nodes to have keys.
657 */
658 trun_key_init(c, &key, le32_to_cpu(trun->inum));
659 err = insert_node(c, lnum, snod->offs, snod->len,
660 &key, snod->sqnum, 1, &used,
661 old_size, new_size);
662 break;
663 }
664 default:
665 ubifs_err(c, "unexpected node type %d in bud LEB %d:%d",
666 snod->type, lnum, snod->offs);
667 err = -EINVAL;
668 goto out_dump;
669 }
670 if (err)
671 goto out;
672 }
673
674 ubifs_assert(ubifs_search_bud(c, lnum));
675 ubifs_assert(sleb->endpt - offs >= used);
676 ubifs_assert(sleb->endpt % c->min_io_size == 0);
677
678 b->dirty = sleb->endpt - offs - used;
679 b->free = c->leb_size - sleb->endpt;
680 dbg_mnt("bud LEB %d replied: dirty %d, free %d",
681 lnum, b->dirty, b->free);
682
683out:
684 ubifs_scan_destroy(sleb);
685 return err;
686
687out_dump:
688 ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs);
689 ubifs_dump_node(c, snod->node);
690 ubifs_scan_destroy(sleb);
691 return -EINVAL;
692}
693
694/**
695 * replay_buds - replay all buds.
696 * @c: UBIFS file-system description object
697 *
698 * This function returns zero in case of success and a negative error code in
699 * case of failure.
700 */
701static int replay_buds(struct ubifs_info *c)
702{
703 struct bud_entry *b;
704 int err;
705 unsigned long long prev_sqnum = 0;
706
707 list_for_each_entry(b, &c->replay_buds, list) {
708 err = replay_bud(c, b);
709 if (err)
710 return err;
711
712 ubifs_assert(b->sqnum > prev_sqnum);
713 prev_sqnum = b->sqnum;
714 }
715
716 return 0;
717}
718
719/**
720 * destroy_bud_list - destroy the list of buds to replay.
721 * @c: UBIFS file-system description object
722 */
723static void destroy_bud_list(struct ubifs_info *c)
724{
725 struct bud_entry *b;
726
727 while (!list_empty(&c->replay_buds)) {
728 b = list_entry(c->replay_buds.next, struct bud_entry, list);
729 list_del(&b->list);
730 kfree(b);
731 }
732}
733
734/**
735 * add_replay_bud - add a bud to the list of buds to replay.
736 * @c: UBIFS file-system description object
737 * @lnum: bud logical eraseblock number to replay
738 * @offs: bud start offset
739 * @jhead: journal head to which this bud belongs
740 * @sqnum: reference node sequence number
741 *
742 * This function returns zero in case of success and a negative error code in
743 * case of failure.
744 */
745static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
746 unsigned long long sqnum)
747{
748 struct ubifs_bud *bud;
749 struct bud_entry *b;
750
751 dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
752
753 bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
754 if (!bud)
755 return -ENOMEM;
756
757 b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
758 if (!b) {
759 kfree(bud);
760 return -ENOMEM;
761 }
762
763 bud->lnum = lnum;
764 bud->start = offs;
765 bud->jhead = jhead;
766 ubifs_add_bud(c, bud);
767
768 b->bud = bud;
769 b->sqnum = sqnum;
770 list_add_tail(&b->list, &c->replay_buds);
771
772 return 0;
773}
774
775/**
776 * validate_ref - validate a reference node.
777 * @c: UBIFS file-system description object
778 * @ref: the reference node to validate
779 * @ref_lnum: LEB number of the reference node
780 * @ref_offs: reference node offset
781 *
782 * This function returns %1 if a bud reference already exists for the LEB. %0 is
783 * returned if the reference node is new, otherwise %-EINVAL is returned if
784 * validation failed.
785 */
786static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
787{
788 struct ubifs_bud *bud;
789 int lnum = le32_to_cpu(ref->lnum);
790 unsigned int offs = le32_to_cpu(ref->offs);
791 unsigned int jhead = le32_to_cpu(ref->jhead);
792
793 /*
794 * ref->offs may point to the end of LEB when the journal head points
795 * to the end of LEB and we write reference node for it during commit.
796 * So this is why we require 'offs > c->leb_size'.
797 */
798 if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
799 lnum < c->main_first || offs > c->leb_size ||
800 offs & (c->min_io_size - 1))
801 return -EINVAL;
802
803 /* Make sure we have not already looked at this bud */
804 bud = ubifs_search_bud(c, lnum);
805 if (bud) {
806 if (bud->jhead == jhead && bud->start <= offs)
807 return 1;
808 ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs);
809 return -EINVAL;
810 }
811
812 return 0;
813}
814
815/**
816 * replay_log_leb - replay a log logical eraseblock.
817 * @c: UBIFS file-system description object
818 * @lnum: log logical eraseblock to replay
819 * @offs: offset to start replaying from
820 * @sbuf: scan buffer
821 *
822 * This function replays a log LEB and returns zero in case of success, %1 if
823 * this is the last LEB in the log, and a negative error code in case of
824 * failure.
825 */
826static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
827{
828 int err;
829 struct ubifs_scan_leb *sleb;
830 struct ubifs_scan_node *snod;
831 const struct ubifs_cs_node *node;
832
833 dbg_mnt("replay log LEB %d:%d", lnum, offs);
834 sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery);
835 if (IS_ERR(sleb)) {
836 if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
837 return PTR_ERR(sleb);
838 /*
839 * Note, the below function will recover this log LEB only if
840 * it is the last, because unclean reboots can possibly corrupt
841 * only the tail of the log.
842 */
843 sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
844 if (IS_ERR(sleb))
845 return PTR_ERR(sleb);
846 }
847
848 if (sleb->nodes_cnt == 0) {
849 err = 1;
850 goto out;
851 }
852
853 node = sleb->buf;
854 snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
855 if (c->cs_sqnum == 0) {
856 /*
857 * This is the first log LEB we are looking at, make sure that
858 * the first node is a commit start node. Also record its
859 * sequence number so that UBIFS can determine where the log
860 * ends, because all nodes which were have higher sequence
861 * numbers.
862 */
863 if (snod->type != UBIFS_CS_NODE) {
864 ubifs_err(c, "first log node at LEB %d:%d is not CS node",
865 lnum, offs);
866 goto out_dump;
867 }
868 if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
869 ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu",
870 lnum, offs,
871 (unsigned long long)le64_to_cpu(node->cmt_no),
872 c->cmt_no);
873 goto out_dump;
874 }
875
876 c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
877 dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
878 }
879
880 if (snod->sqnum < c->cs_sqnum) {
881 /*
882 * This means that we reached end of log and now
883 * look to the older log data, which was already
884 * committed but the eraseblock was not erased (UBIFS
885 * only un-maps it). So this basically means we have to
886 * exit with "end of log" code.
887 */
888 err = 1;
889 goto out;
890 }
891
892 /* Make sure the first node sits at offset zero of the LEB */
893 if (snod->offs != 0) {
894 ubifs_err(c, "first node is not at zero offset");
895 goto out_dump;
896 }
897
898 list_for_each_entry(snod, &sleb->nodes, list) {
899 cond_resched();
900
901 if (snod->sqnum >= SQNUM_WATERMARK) {
902 ubifs_err(c, "file system's life ended");
903 goto out_dump;
904 }
905
906 if (snod->sqnum < c->cs_sqnum) {
907 ubifs_err(c, "bad sqnum %llu, commit sqnum %llu",
908 snod->sqnum, c->cs_sqnum);
909 goto out_dump;
910 }
911
912 if (snod->sqnum > c->max_sqnum)
913 c->max_sqnum = snod->sqnum;
914
915 switch (snod->type) {
916 case UBIFS_REF_NODE: {
917 const struct ubifs_ref_node *ref = snod->node;
918
919 err = validate_ref(c, ref);
920 if (err == 1)
921 break; /* Already have this bud */
922 if (err)
923 goto out_dump;
924
925 err = add_replay_bud(c, le32_to_cpu(ref->lnum),
926 le32_to_cpu(ref->offs),
927 le32_to_cpu(ref->jhead),
928 snod->sqnum);
929 if (err)
930 goto out;
931
932 break;
933 }
934 case UBIFS_CS_NODE:
935 /* Make sure it sits at the beginning of LEB */
936 if (snod->offs != 0) {
937 ubifs_err(c, "unexpected node in log");
938 goto out_dump;
939 }
940 break;
941 default:
942 ubifs_err(c, "unexpected node in log");
943 goto out_dump;
944 }
945 }
946
947 if (sleb->endpt || c->lhead_offs >= c->leb_size) {
948 c->lhead_lnum = lnum;
949 c->lhead_offs = sleb->endpt;
950 }
951
952 err = !sleb->endpt;
953out:
954 ubifs_scan_destroy(sleb);
955 return err;
956
957out_dump:
958 ubifs_err(c, "log error detected while replaying the log at LEB %d:%d",
959 lnum, offs + snod->offs);
960 ubifs_dump_node(c, snod->node);
961 ubifs_scan_destroy(sleb);
962 return -EINVAL;
963}
964
965/**
966 * take_ihead - update the status of the index head in lprops to 'taken'.
967 * @c: UBIFS file-system description object
968 *
969 * This function returns the amount of free space in the index head LEB or a
970 * negative error code.
971 */
972static int take_ihead(struct ubifs_info *c)
973{
974 const struct ubifs_lprops *lp;
975 int err, free;
976
977 ubifs_get_lprops(c);
978
979 lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
980 if (IS_ERR(lp)) {
981 err = PTR_ERR(lp);
982 goto out;
983 }
984
985 free = lp->free;
986
987 lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
988 lp->flags | LPROPS_TAKEN, 0);
989 if (IS_ERR(lp)) {
990 err = PTR_ERR(lp);
991 goto out;
992 }
993
994 err = free;
995out:
996 ubifs_release_lprops(c);
997 return err;
998}
999
1000/**
1001 * ubifs_replay_journal - replay journal.
1002 * @c: UBIFS file-system description object
1003 *
1004 * This function scans the journal, replays and cleans it up. It makes sure all
1005 * memory data structures related to uncommitted journal are built (dirty TNC
1006 * tree, tree of buds, modified lprops, etc).
1007 */
1008int ubifs_replay_journal(struct ubifs_info *c)
1009{
1010 int err, lnum, free;
1011
1012 BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
1013
1014 /* Update the status of the index head in lprops to 'taken' */
1015 free = take_ihead(c);
1016 if (free < 0)
1017 return free; /* Error code */
1018
1019 if (c->ihead_offs != c->leb_size - free) {
1020 ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum,
1021 c->ihead_offs);
1022 return -EINVAL;
1023 }
1024
1025 dbg_mnt("start replaying the journal");
1026 c->replaying = 1;
1027 lnum = c->ltail_lnum = c->lhead_lnum;
1028
1029 do {
1030 err = replay_log_leb(c, lnum, 0, c->sbuf);
1031 if (err == 1) {
1032 if (lnum != c->lhead_lnum)
1033 /* We hit the end of the log */
1034 break;
1035
1036 /*
1037 * The head of the log must always start with the
1038 * "commit start" node on a properly formatted UBIFS.
1039 * But we found no nodes at all, which means that
1040 * someting went wrong and we cannot proceed mounting
1041 * the file-system.
1042 */
1043 ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted",
1044 lnum, 0);
1045 err = -EINVAL;
1046 }
1047 if (err)
1048 goto out;
1049 lnum = ubifs_next_log_lnum(c, lnum);
1050 } while (lnum != c->ltail_lnum);
1051
1052 err = replay_buds(c);
1053 if (err)
1054 goto out;
1055
1056 err = apply_replay_list(c);
1057 if (err)
1058 goto out;
1059
1060 err = set_buds_lprops(c);
1061 if (err)
1062 goto out;
1063
1064 /*
1065 * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
1066 * to roughly estimate index growth. Things like @c->bi.min_idx_lebs
1067 * depend on it. This means we have to initialize it to make sure
1068 * budgeting works properly.
1069 */
1070 c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
1071 c->bi.uncommitted_idx *= c->max_idx_node_sz;
1072
1073 ubifs_assert(c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
1074 dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu",
1075 c->lhead_lnum, c->lhead_offs, c->max_sqnum,
1076 (unsigned long)c->highest_inum);
1077out:
1078 destroy_replay_list(c);
1079 destroy_bud_list(c);
1080 c->replaying = 0;
1081 return err;
1082}
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: Adrian Hunter
8 * Artem Bityutskiy (Битюцкий Артём)
9 */
10
11/*
12 * This file contains journal replay code. It runs when the file-system is being
13 * mounted and requires no locking.
14 *
15 * The larger is the journal, the longer it takes to scan it, so the longer it
16 * takes to mount UBIFS. This is why the journal has limited size which may be
17 * changed depending on the system requirements. But a larger journal gives
18 * faster I/O speed because it writes the index less frequently. So this is a
19 * trade-off. Also, the journal is indexed by the in-memory index (TNC), so the
20 * larger is the journal, the more memory its index may consume.
21 */
22
23#include "ubifs.h"
24#include <linux/list_sort.h>
25#include <crypto/hash.h>
26#include <crypto/algapi.h>
27
28/**
29 * struct replay_entry - replay list entry.
30 * @lnum: logical eraseblock number of the node
31 * @offs: node offset
32 * @len: node length
33 * @deletion: non-zero if this entry corresponds to a node deletion
34 * @sqnum: node sequence number
35 * @list: links the replay list
36 * @key: node key
37 * @nm: directory entry name
38 * @old_size: truncation old size
39 * @new_size: truncation new size
40 *
41 * The replay process first scans all buds and builds the replay list, then
42 * sorts the replay list in nodes sequence number order, and then inserts all
43 * the replay entries to the TNC.
44 */
45struct replay_entry {
46 int lnum;
47 int offs;
48 int len;
49 u8 hash[UBIFS_HASH_ARR_SZ];
50 unsigned int deletion:1;
51 unsigned long long sqnum;
52 struct list_head list;
53 union ubifs_key key;
54 union {
55 struct fscrypt_name nm;
56 struct {
57 loff_t old_size;
58 loff_t new_size;
59 };
60 };
61};
62
63/**
64 * struct bud_entry - entry in the list of buds to replay.
65 * @list: next bud in the list
66 * @bud: bud description object
67 * @sqnum: reference node sequence number
68 * @free: free bytes in the bud
69 * @dirty: dirty bytes in the bud
70 */
71struct bud_entry {
72 struct list_head list;
73 struct ubifs_bud *bud;
74 unsigned long long sqnum;
75 int free;
76 int dirty;
77};
78
79/**
80 * set_bud_lprops - set free and dirty space used by a bud.
81 * @c: UBIFS file-system description object
82 * @b: bud entry which describes the bud
83 *
84 * This function makes sure the LEB properties of bud @b are set correctly
85 * after the replay. Returns zero in case of success and a negative error code
86 * in case of failure.
87 */
88static int set_bud_lprops(struct ubifs_info *c, struct bud_entry *b)
89{
90 const struct ubifs_lprops *lp;
91 int err = 0, dirty;
92
93 ubifs_get_lprops(c);
94
95 lp = ubifs_lpt_lookup_dirty(c, b->bud->lnum);
96 if (IS_ERR(lp)) {
97 err = PTR_ERR(lp);
98 goto out;
99 }
100
101 dirty = lp->dirty;
102 if (b->bud->start == 0 && (lp->free != c->leb_size || lp->dirty != 0)) {
103 /*
104 * The LEB was added to the journal with a starting offset of
105 * zero which means the LEB must have been empty. The LEB
106 * property values should be @lp->free == @c->leb_size and
107 * @lp->dirty == 0, but that is not the case. The reason is that
108 * the LEB had been garbage collected before it became the bud,
109 * and there was not commit inbetween. The garbage collector
110 * resets the free and dirty space without recording it
111 * anywhere except lprops, so if there was no commit then
112 * lprops does not have that information.
113 *
114 * We do not need to adjust free space because the scan has told
115 * us the exact value which is recorded in the replay entry as
116 * @b->free.
117 *
118 * However we do need to subtract from the dirty space the
119 * amount of space that the garbage collector reclaimed, which
120 * is the whole LEB minus the amount of space that was free.
121 */
122 dbg_mnt("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
123 lp->free, lp->dirty);
124 dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
125 lp->free, lp->dirty);
126 dirty -= c->leb_size - lp->free;
127 /*
128 * If the replay order was perfect the dirty space would now be
129 * zero. The order is not perfect because the journal heads
130 * race with each other. This is not a problem but is does mean
131 * that the dirty space may temporarily exceed c->leb_size
132 * during the replay.
133 */
134 if (dirty != 0)
135 dbg_mnt("LEB %d lp: %d free %d dirty replay: %d free %d dirty",
136 b->bud->lnum, lp->free, lp->dirty, b->free,
137 b->dirty);
138 }
139 lp = ubifs_change_lp(c, lp, b->free, dirty + b->dirty,
140 lp->flags | LPROPS_TAKEN, 0);
141 if (IS_ERR(lp)) {
142 err = PTR_ERR(lp);
143 goto out;
144 }
145
146 /* Make sure the journal head points to the latest bud */
147 err = ubifs_wbuf_seek_nolock(&c->jheads[b->bud->jhead].wbuf,
148 b->bud->lnum, c->leb_size - b->free);
149
150out:
151 ubifs_release_lprops(c);
152 return err;
153}
154
155/**
156 * set_buds_lprops - set free and dirty space for all replayed buds.
157 * @c: UBIFS file-system description object
158 *
159 * This function sets LEB properties for all replayed buds. Returns zero in
160 * case of success and a negative error code in case of failure.
161 */
162static int set_buds_lprops(struct ubifs_info *c)
163{
164 struct bud_entry *b;
165 int err;
166
167 list_for_each_entry(b, &c->replay_buds, list) {
168 err = set_bud_lprops(c, b);
169 if (err)
170 return err;
171 }
172
173 return 0;
174}
175
176/**
177 * trun_remove_range - apply a replay entry for a truncation to the TNC.
178 * @c: UBIFS file-system description object
179 * @r: replay entry of truncation
180 */
181static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
182{
183 unsigned min_blk, max_blk;
184 union ubifs_key min_key, max_key;
185 ino_t ino;
186
187 min_blk = r->new_size / UBIFS_BLOCK_SIZE;
188 if (r->new_size & (UBIFS_BLOCK_SIZE - 1))
189 min_blk += 1;
190
191 max_blk = r->old_size / UBIFS_BLOCK_SIZE;
192 if ((r->old_size & (UBIFS_BLOCK_SIZE - 1)) == 0)
193 max_blk -= 1;
194
195 ino = key_inum(c, &r->key);
196
197 data_key_init(c, &min_key, ino, min_blk);
198 data_key_init(c, &max_key, ino, max_blk);
199
200 return ubifs_tnc_remove_range(c, &min_key, &max_key);
201}
202
203/**
204 * inode_still_linked - check whether inode in question will be re-linked.
205 * @c: UBIFS file-system description object
206 * @rino: replay entry to test
207 *
208 * O_TMPFILE files can be re-linked, this means link count goes from 0 to 1.
209 * This case needs special care, otherwise all references to the inode will
210 * be removed upon the first replay entry of an inode with link count 0
211 * is found.
212 */
213static bool inode_still_linked(struct ubifs_info *c, struct replay_entry *rino)
214{
215 struct replay_entry *r;
216
217 ubifs_assert(c, rino->deletion);
218 ubifs_assert(c, key_type(c, &rino->key) == UBIFS_INO_KEY);
219
220 /*
221 * Find the most recent entry for the inode behind @rino and check
222 * whether it is a deletion.
223 */
224 list_for_each_entry_reverse(r, &c->replay_list, list) {
225 ubifs_assert(c, r->sqnum >= rino->sqnum);
226 if (key_inum(c, &r->key) == key_inum(c, &rino->key))
227 return r->deletion == 0;
228
229 }
230
231 ubifs_assert(c, 0);
232 return false;
233}
234
235/**
236 * apply_replay_entry - apply a replay entry to the TNC.
237 * @c: UBIFS file-system description object
238 * @r: replay entry to apply
239 *
240 * Apply a replay entry to the TNC.
241 */
242static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
243{
244 int err;
245
246 dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ",
247 r->lnum, r->offs, r->len, r->deletion, r->sqnum);
248
249 if (is_hash_key(c, &r->key)) {
250 if (r->deletion)
251 err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
252 else
253 err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
254 r->len, r->hash, &r->nm);
255 } else {
256 if (r->deletion)
257 switch (key_type(c, &r->key)) {
258 case UBIFS_INO_KEY:
259 {
260 ino_t inum = key_inum(c, &r->key);
261
262 if (inode_still_linked(c, r)) {
263 err = 0;
264 break;
265 }
266
267 err = ubifs_tnc_remove_ino(c, inum);
268 break;
269 }
270 case UBIFS_TRUN_KEY:
271 err = trun_remove_range(c, r);
272 break;
273 default:
274 err = ubifs_tnc_remove(c, &r->key);
275 break;
276 }
277 else
278 err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
279 r->len, r->hash);
280 if (err)
281 return err;
282
283 if (c->need_recovery)
284 err = ubifs_recover_size_accum(c, &r->key, r->deletion,
285 r->new_size);
286 }
287
288 return err;
289}
290
291/**
292 * replay_entries_cmp - compare 2 replay entries.
293 * @priv: UBIFS file-system description object
294 * @a: first replay entry
295 * @b: second replay entry
296 *
297 * This is a comparios function for 'list_sort()' which compares 2 replay
298 * entries @a and @b by comparing their sequence numer. Returns %1 if @a has
299 * greater sequence number and %-1 otherwise.
300 */
301static int replay_entries_cmp(void *priv, struct list_head *a,
302 struct list_head *b)
303{
304 struct ubifs_info *c = priv;
305 struct replay_entry *ra, *rb;
306
307 cond_resched();
308 if (a == b)
309 return 0;
310
311 ra = list_entry(a, struct replay_entry, list);
312 rb = list_entry(b, struct replay_entry, list);
313 ubifs_assert(c, ra->sqnum != rb->sqnum);
314 if (ra->sqnum > rb->sqnum)
315 return 1;
316 return -1;
317}
318
319/**
320 * apply_replay_list - apply the replay list to the TNC.
321 * @c: UBIFS file-system description object
322 *
323 * Apply all entries in the replay list to the TNC. Returns zero in case of
324 * success and a negative error code in case of failure.
325 */
326static int apply_replay_list(struct ubifs_info *c)
327{
328 struct replay_entry *r;
329 int err;
330
331 list_sort(c, &c->replay_list, &replay_entries_cmp);
332
333 list_for_each_entry(r, &c->replay_list, list) {
334 cond_resched();
335
336 err = apply_replay_entry(c, r);
337 if (err)
338 return err;
339 }
340
341 return 0;
342}
343
344/**
345 * destroy_replay_list - destroy the replay.
346 * @c: UBIFS file-system description object
347 *
348 * Destroy the replay list.
349 */
350static void destroy_replay_list(struct ubifs_info *c)
351{
352 struct replay_entry *r, *tmp;
353
354 list_for_each_entry_safe(r, tmp, &c->replay_list, list) {
355 if (is_hash_key(c, &r->key))
356 kfree(fname_name(&r->nm));
357 list_del(&r->list);
358 kfree(r);
359 }
360}
361
362/**
363 * insert_node - insert a node to the replay list
364 * @c: UBIFS file-system description object
365 * @lnum: node logical eraseblock number
366 * @offs: node offset
367 * @len: node length
368 * @key: node key
369 * @sqnum: sequence number
370 * @deletion: non-zero if this is a deletion
371 * @used: number of bytes in use in a LEB
372 * @old_size: truncation old size
373 * @new_size: truncation new size
374 *
375 * This function inserts a scanned non-direntry node to the replay list. The
376 * replay list contains @struct replay_entry elements, and we sort this list in
377 * sequence number order before applying it. The replay list is applied at the
378 * very end of the replay process. Since the list is sorted in sequence number
379 * order, the older modifications are applied first. This function returns zero
380 * in case of success and a negative error code in case of failure.
381 */
382static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
383 const u8 *hash, union ubifs_key *key,
384 unsigned long long sqnum, int deletion, int *used,
385 loff_t old_size, loff_t new_size)
386{
387 struct replay_entry *r;
388
389 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
390
391 if (key_inum(c, key) >= c->highest_inum)
392 c->highest_inum = key_inum(c, key);
393
394 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
395 if (!r)
396 return -ENOMEM;
397
398 if (!deletion)
399 *used += ALIGN(len, 8);
400 r->lnum = lnum;
401 r->offs = offs;
402 r->len = len;
403 ubifs_copy_hash(c, hash, r->hash);
404 r->deletion = !!deletion;
405 r->sqnum = sqnum;
406 key_copy(c, key, &r->key);
407 r->old_size = old_size;
408 r->new_size = new_size;
409
410 list_add_tail(&r->list, &c->replay_list);
411 return 0;
412}
413
414/**
415 * insert_dent - insert a directory entry node into the replay list.
416 * @c: UBIFS file-system description object
417 * @lnum: node logical eraseblock number
418 * @offs: node offset
419 * @len: node length
420 * @key: node key
421 * @name: directory entry name
422 * @nlen: directory entry name length
423 * @sqnum: sequence number
424 * @deletion: non-zero if this is a deletion
425 * @used: number of bytes in use in a LEB
426 *
427 * This function inserts a scanned directory entry node or an extended
428 * attribute entry to the replay list. Returns zero in case of success and a
429 * negative error code in case of failure.
430 */
431static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
432 const u8 *hash, union ubifs_key *key,
433 const char *name, int nlen, unsigned long long sqnum,
434 int deletion, int *used)
435{
436 struct replay_entry *r;
437 char *nbuf;
438
439 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
440 if (key_inum(c, key) >= c->highest_inum)
441 c->highest_inum = key_inum(c, key);
442
443 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
444 if (!r)
445 return -ENOMEM;
446
447 nbuf = kmalloc(nlen + 1, GFP_KERNEL);
448 if (!nbuf) {
449 kfree(r);
450 return -ENOMEM;
451 }
452
453 if (!deletion)
454 *used += ALIGN(len, 8);
455 r->lnum = lnum;
456 r->offs = offs;
457 r->len = len;
458 ubifs_copy_hash(c, hash, r->hash);
459 r->deletion = !!deletion;
460 r->sqnum = sqnum;
461 key_copy(c, key, &r->key);
462 fname_len(&r->nm) = nlen;
463 memcpy(nbuf, name, nlen);
464 nbuf[nlen] = '\0';
465 fname_name(&r->nm) = nbuf;
466
467 list_add_tail(&r->list, &c->replay_list);
468 return 0;
469}
470
471/**
472 * ubifs_validate_entry - validate directory or extended attribute entry node.
473 * @c: UBIFS file-system description object
474 * @dent: the node to validate
475 *
476 * This function validates directory or extended attribute entry node @dent.
477 * Returns zero if the node is all right and a %-EINVAL if not.
478 */
479int ubifs_validate_entry(struct ubifs_info *c,
480 const struct ubifs_dent_node *dent)
481{
482 int key_type = key_type_flash(c, dent->key);
483 int nlen = le16_to_cpu(dent->nlen);
484
485 if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
486 dent->type >= UBIFS_ITYPES_CNT ||
487 nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
488 (key_type == UBIFS_XENT_KEY && strnlen(dent->name, nlen) != nlen) ||
489 le64_to_cpu(dent->inum) > MAX_INUM) {
490 ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ?
491 "directory entry" : "extended attribute entry");
492 return -EINVAL;
493 }
494
495 if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
496 ubifs_err(c, "bad key type %d", key_type);
497 return -EINVAL;
498 }
499
500 return 0;
501}
502
503/**
504 * is_last_bud - check if the bud is the last in the journal head.
505 * @c: UBIFS file-system description object
506 * @bud: bud description object
507 *
508 * This function checks if bud @bud is the last bud in its journal head. This
509 * information is then used by 'replay_bud()' to decide whether the bud can
510 * have corruptions or not. Indeed, only last buds can be corrupted by power
511 * cuts. Returns %1 if this is the last bud, and %0 if not.
512 */
513static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
514{
515 struct ubifs_jhead *jh = &c->jheads[bud->jhead];
516 struct ubifs_bud *next;
517 uint32_t data;
518 int err;
519
520 if (list_is_last(&bud->list, &jh->buds_list))
521 return 1;
522
523 /*
524 * The following is a quirk to make sure we work correctly with UBIFS
525 * images used with older UBIFS.
526 *
527 * Normally, the last bud will be the last in the journal head's list
528 * of bud. However, there is one exception if the UBIFS image belongs
529 * to older UBIFS. This is fairly unlikely: one would need to use old
530 * UBIFS, then have a power cut exactly at the right point, and then
531 * try to mount this image with new UBIFS.
532 *
533 * The exception is: it is possible to have 2 buds A and B, A goes
534 * before B, and B is the last, bud B is contains no data, and bud A is
535 * corrupted at the end. The reason is that in older versions when the
536 * journal code switched the next bud (from A to B), it first added a
537 * log reference node for the new bud (B), and only after this it
538 * synchronized the write-buffer of current bud (A). But later this was
539 * changed and UBIFS started to always synchronize the write-buffer of
540 * the bud (A) before writing the log reference for the new bud (B).
541 *
542 * But because older UBIFS always synchronized A's write-buffer before
543 * writing to B, we can recognize this exceptional situation but
544 * checking the contents of bud B - if it is empty, then A can be
545 * treated as the last and we can recover it.
546 *
547 * TODO: remove this piece of code in a couple of years (today it is
548 * 16.05.2011).
549 */
550 next = list_entry(bud->list.next, struct ubifs_bud, list);
551 if (!list_is_last(&next->list, &jh->buds_list))
552 return 0;
553
554 err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1);
555 if (err)
556 return 0;
557
558 return data == 0xFFFFFFFF;
559}
560
561/* authenticate_sleb_hash and authenticate_sleb_hmac are split out for stack usage */
562static int authenticate_sleb_hash(struct ubifs_info *c, struct shash_desc *log_hash, u8 *hash)
563{
564 SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
565
566 hash_desc->tfm = c->hash_tfm;
567
568 ubifs_shash_copy_state(c, log_hash, hash_desc);
569 return crypto_shash_final(hash_desc, hash);
570}
571
572static int authenticate_sleb_hmac(struct ubifs_info *c, u8 *hash, u8 *hmac)
573{
574 SHASH_DESC_ON_STACK(hmac_desc, c->hmac_tfm);
575
576 hmac_desc->tfm = c->hmac_tfm;
577
578 return crypto_shash_digest(hmac_desc, hash, c->hash_len, hmac);
579}
580
581/**
582 * authenticate_sleb - authenticate one scan LEB
583 * @c: UBIFS file-system description object
584 * @sleb: the scan LEB to authenticate
585 * @log_hash:
586 * @is_last: if true, this is is the last LEB
587 *
588 * This function iterates over the buds of a single LEB authenticating all buds
589 * with the authentication nodes on this LEB. Authentication nodes are written
590 * after some buds and contain a HMAC covering the authentication node itself
591 * and the buds between the last authentication node and the current
592 * authentication node. It can happen that the last buds cannot be authenticated
593 * because a powercut happened when some nodes were written but not the
594 * corresponding authentication node. This function returns the number of nodes
595 * that could be authenticated or a negative error code.
596 */
597static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
598 struct shash_desc *log_hash, int is_last)
599{
600 int n_not_auth = 0;
601 struct ubifs_scan_node *snod;
602 int n_nodes = 0;
603 int err;
604 u8 *hash, *hmac;
605
606 if (!ubifs_authenticated(c))
607 return sleb->nodes_cnt;
608
609 hash = kmalloc(crypto_shash_descsize(c->hash_tfm), GFP_NOFS);
610 hmac = kmalloc(c->hmac_desc_len, GFP_NOFS);
611 if (!hash || !hmac) {
612 err = -ENOMEM;
613 goto out;
614 }
615
616 list_for_each_entry(snod, &sleb->nodes, list) {
617
618 n_nodes++;
619
620 if (snod->type == UBIFS_AUTH_NODE) {
621 struct ubifs_auth_node *auth = snod->node;
622
623 err = authenticate_sleb_hash(c, log_hash, hash);
624 if (err)
625 goto out;
626
627 err = authenticate_sleb_hmac(c, hash, hmac);
628 if (err)
629 goto out;
630
631 err = ubifs_check_hmac(c, auth->hmac, hmac);
632 if (err) {
633 err = -EPERM;
634 goto out;
635 }
636 n_not_auth = 0;
637 } else {
638 err = crypto_shash_update(log_hash, snod->node,
639 snod->len);
640 if (err)
641 goto out;
642 n_not_auth++;
643 }
644 }
645
646 /*
647 * A powercut can happen when some nodes were written, but not yet
648 * the corresponding authentication node. This may only happen on
649 * the last bud though.
650 */
651 if (n_not_auth) {
652 if (is_last) {
653 dbg_mnt("%d unauthenticated nodes found on LEB %d, Ignoring them",
654 n_not_auth, sleb->lnum);
655 err = 0;
656 } else {
657 dbg_mnt("%d unauthenticated nodes found on non-last LEB %d",
658 n_not_auth, sleb->lnum);
659 err = -EPERM;
660 }
661 } else {
662 err = 0;
663 }
664out:
665 kfree(hash);
666 kfree(hmac);
667
668 return err ? err : n_nodes - n_not_auth;
669}
670
671/**
672 * replay_bud - replay a bud logical eraseblock.
673 * @c: UBIFS file-system description object
674 * @b: bud entry which describes the bud
675 *
676 * This function replays bud @bud, recovers it if needed, and adds all nodes
677 * from this bud to the replay list. Returns zero in case of success and a
678 * negative error code in case of failure.
679 */
680static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
681{
682 int is_last = is_last_bud(c, b->bud);
683 int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start;
684 int n_nodes, n = 0;
685 struct ubifs_scan_leb *sleb;
686 struct ubifs_scan_node *snod;
687
688 dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d",
689 lnum, b->bud->jhead, offs, is_last);
690
691 if (c->need_recovery && is_last)
692 /*
693 * Recover only last LEBs in the journal heads, because power
694 * cuts may cause corruptions only in these LEBs, because only
695 * these LEBs could possibly be written to at the power cut
696 * time.
697 */
698 sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead);
699 else
700 sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0);
701 if (IS_ERR(sleb))
702 return PTR_ERR(sleb);
703
704 n_nodes = authenticate_sleb(c, sleb, b->bud->log_hash, is_last);
705 if (n_nodes < 0) {
706 err = n_nodes;
707 goto out;
708 }
709
710 ubifs_shash_copy_state(c, b->bud->log_hash,
711 c->jheads[b->bud->jhead].log_hash);
712
713 /*
714 * The bud does not have to start from offset zero - the beginning of
715 * the 'lnum' LEB may contain previously committed data. One of the
716 * things we have to do in replay is to correctly update lprops with
717 * newer information about this LEB.
718 *
719 * At this point lprops thinks that this LEB has 'c->leb_size - offs'
720 * bytes of free space because it only contain information about
721 * committed data.
722 *
723 * But we know that real amount of free space is 'c->leb_size -
724 * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
725 * 'sleb->endpt' is used by bud data. We have to correctly calculate
726 * how much of these data are dirty and update lprops with this
727 * information.
728 *
729 * The dirt in that LEB region is comprised of padding nodes, deletion
730 * nodes, truncation nodes and nodes which are obsoleted by subsequent
731 * nodes in this LEB. So instead of calculating clean space, we
732 * calculate used space ('used' variable).
733 */
734
735 list_for_each_entry(snod, &sleb->nodes, list) {
736 u8 hash[UBIFS_HASH_ARR_SZ];
737 int deletion = 0;
738
739 cond_resched();
740
741 if (snod->sqnum >= SQNUM_WATERMARK) {
742 ubifs_err(c, "file system's life ended");
743 goto out_dump;
744 }
745
746 ubifs_node_calc_hash(c, snod->node, hash);
747
748 if (snod->sqnum > c->max_sqnum)
749 c->max_sqnum = snod->sqnum;
750
751 switch (snod->type) {
752 case UBIFS_INO_NODE:
753 {
754 struct ubifs_ino_node *ino = snod->node;
755 loff_t new_size = le64_to_cpu(ino->size);
756
757 if (le32_to_cpu(ino->nlink) == 0)
758 deletion = 1;
759 err = insert_node(c, lnum, snod->offs, snod->len, hash,
760 &snod->key, snod->sqnum, deletion,
761 &used, 0, new_size);
762 break;
763 }
764 case UBIFS_DATA_NODE:
765 {
766 struct ubifs_data_node *dn = snod->node;
767 loff_t new_size = le32_to_cpu(dn->size) +
768 key_block(c, &snod->key) *
769 UBIFS_BLOCK_SIZE;
770
771 err = insert_node(c, lnum, snod->offs, snod->len, hash,
772 &snod->key, snod->sqnum, deletion,
773 &used, 0, new_size);
774 break;
775 }
776 case UBIFS_DENT_NODE:
777 case UBIFS_XENT_NODE:
778 {
779 struct ubifs_dent_node *dent = snod->node;
780
781 err = ubifs_validate_entry(c, dent);
782 if (err)
783 goto out_dump;
784
785 err = insert_dent(c, lnum, snod->offs, snod->len, hash,
786 &snod->key, dent->name,
787 le16_to_cpu(dent->nlen), snod->sqnum,
788 !le64_to_cpu(dent->inum), &used);
789 break;
790 }
791 case UBIFS_TRUN_NODE:
792 {
793 struct ubifs_trun_node *trun = snod->node;
794 loff_t old_size = le64_to_cpu(trun->old_size);
795 loff_t new_size = le64_to_cpu(trun->new_size);
796 union ubifs_key key;
797
798 /* Validate truncation node */
799 if (old_size < 0 || old_size > c->max_inode_sz ||
800 new_size < 0 || new_size > c->max_inode_sz ||
801 old_size <= new_size) {
802 ubifs_err(c, "bad truncation node");
803 goto out_dump;
804 }
805
806 /*
807 * Create a fake truncation key just to use the same
808 * functions which expect nodes to have keys.
809 */
810 trun_key_init(c, &key, le32_to_cpu(trun->inum));
811 err = insert_node(c, lnum, snod->offs, snod->len, hash,
812 &key, snod->sqnum, 1, &used,
813 old_size, new_size);
814 break;
815 }
816 case UBIFS_AUTH_NODE:
817 break;
818 default:
819 ubifs_err(c, "unexpected node type %d in bud LEB %d:%d",
820 snod->type, lnum, snod->offs);
821 err = -EINVAL;
822 goto out_dump;
823 }
824 if (err)
825 goto out;
826
827 n++;
828 if (n == n_nodes)
829 break;
830 }
831
832 ubifs_assert(c, ubifs_search_bud(c, lnum));
833 ubifs_assert(c, sleb->endpt - offs >= used);
834 ubifs_assert(c, sleb->endpt % c->min_io_size == 0);
835
836 b->dirty = sleb->endpt - offs - used;
837 b->free = c->leb_size - sleb->endpt;
838 dbg_mnt("bud LEB %d replied: dirty %d, free %d",
839 lnum, b->dirty, b->free);
840
841out:
842 ubifs_scan_destroy(sleb);
843 return err;
844
845out_dump:
846 ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs);
847 ubifs_dump_node(c, snod->node);
848 ubifs_scan_destroy(sleb);
849 return -EINVAL;
850}
851
852/**
853 * replay_buds - replay all buds.
854 * @c: UBIFS file-system description object
855 *
856 * This function returns zero in case of success and a negative error code in
857 * case of failure.
858 */
859static int replay_buds(struct ubifs_info *c)
860{
861 struct bud_entry *b;
862 int err;
863 unsigned long long prev_sqnum = 0;
864
865 list_for_each_entry(b, &c->replay_buds, list) {
866 err = replay_bud(c, b);
867 if (err)
868 return err;
869
870 ubifs_assert(c, b->sqnum > prev_sqnum);
871 prev_sqnum = b->sqnum;
872 }
873
874 return 0;
875}
876
877/**
878 * destroy_bud_list - destroy the list of buds to replay.
879 * @c: UBIFS file-system description object
880 */
881static void destroy_bud_list(struct ubifs_info *c)
882{
883 struct bud_entry *b;
884
885 while (!list_empty(&c->replay_buds)) {
886 b = list_entry(c->replay_buds.next, struct bud_entry, list);
887 list_del(&b->list);
888 kfree(b);
889 }
890}
891
892/**
893 * add_replay_bud - add a bud to the list of buds to replay.
894 * @c: UBIFS file-system description object
895 * @lnum: bud logical eraseblock number to replay
896 * @offs: bud start offset
897 * @jhead: journal head to which this bud belongs
898 * @sqnum: reference node sequence number
899 *
900 * This function returns zero in case of success and a negative error code in
901 * case of failure.
902 */
903static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
904 unsigned long long sqnum)
905{
906 struct ubifs_bud *bud;
907 struct bud_entry *b;
908 int err;
909
910 dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
911
912 bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
913 if (!bud)
914 return -ENOMEM;
915
916 b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
917 if (!b) {
918 err = -ENOMEM;
919 goto out;
920 }
921
922 bud->lnum = lnum;
923 bud->start = offs;
924 bud->jhead = jhead;
925 bud->log_hash = ubifs_hash_get_desc(c);
926 if (IS_ERR(bud->log_hash)) {
927 err = PTR_ERR(bud->log_hash);
928 goto out;
929 }
930
931 ubifs_shash_copy_state(c, c->log_hash, bud->log_hash);
932
933 ubifs_add_bud(c, bud);
934
935 b->bud = bud;
936 b->sqnum = sqnum;
937 list_add_tail(&b->list, &c->replay_buds);
938
939 return 0;
940out:
941 kfree(bud);
942 kfree(b);
943
944 return err;
945}
946
947/**
948 * validate_ref - validate a reference node.
949 * @c: UBIFS file-system description object
950 * @ref: the reference node to validate
951 * @ref_lnum: LEB number of the reference node
952 * @ref_offs: reference node offset
953 *
954 * This function returns %1 if a bud reference already exists for the LEB. %0 is
955 * returned if the reference node is new, otherwise %-EINVAL is returned if
956 * validation failed.
957 */
958static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
959{
960 struct ubifs_bud *bud;
961 int lnum = le32_to_cpu(ref->lnum);
962 unsigned int offs = le32_to_cpu(ref->offs);
963 unsigned int jhead = le32_to_cpu(ref->jhead);
964
965 /*
966 * ref->offs may point to the end of LEB when the journal head points
967 * to the end of LEB and we write reference node for it during commit.
968 * So this is why we require 'offs > c->leb_size'.
969 */
970 if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
971 lnum < c->main_first || offs > c->leb_size ||
972 offs & (c->min_io_size - 1))
973 return -EINVAL;
974
975 /* Make sure we have not already looked at this bud */
976 bud = ubifs_search_bud(c, lnum);
977 if (bud) {
978 if (bud->jhead == jhead && bud->start <= offs)
979 return 1;
980 ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs);
981 return -EINVAL;
982 }
983
984 return 0;
985}
986
987/**
988 * replay_log_leb - replay a log logical eraseblock.
989 * @c: UBIFS file-system description object
990 * @lnum: log logical eraseblock to replay
991 * @offs: offset to start replaying from
992 * @sbuf: scan buffer
993 *
994 * This function replays a log LEB and returns zero in case of success, %1 if
995 * this is the last LEB in the log, and a negative error code in case of
996 * failure.
997 */
998static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
999{
1000 int err;
1001 struct ubifs_scan_leb *sleb;
1002 struct ubifs_scan_node *snod;
1003 const struct ubifs_cs_node *node;
1004
1005 dbg_mnt("replay log LEB %d:%d", lnum, offs);
1006 sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery);
1007 if (IS_ERR(sleb)) {
1008 if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
1009 return PTR_ERR(sleb);
1010 /*
1011 * Note, the below function will recover this log LEB only if
1012 * it is the last, because unclean reboots can possibly corrupt
1013 * only the tail of the log.
1014 */
1015 sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
1016 if (IS_ERR(sleb))
1017 return PTR_ERR(sleb);
1018 }
1019
1020 if (sleb->nodes_cnt == 0) {
1021 err = 1;
1022 goto out;
1023 }
1024
1025 node = sleb->buf;
1026 snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
1027 if (c->cs_sqnum == 0) {
1028 /*
1029 * This is the first log LEB we are looking at, make sure that
1030 * the first node is a commit start node. Also record its
1031 * sequence number so that UBIFS can determine where the log
1032 * ends, because all nodes which were have higher sequence
1033 * numbers.
1034 */
1035 if (snod->type != UBIFS_CS_NODE) {
1036 ubifs_err(c, "first log node at LEB %d:%d is not CS node",
1037 lnum, offs);
1038 goto out_dump;
1039 }
1040 if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
1041 ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu",
1042 lnum, offs,
1043 (unsigned long long)le64_to_cpu(node->cmt_no),
1044 c->cmt_no);
1045 goto out_dump;
1046 }
1047
1048 c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
1049 dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
1050
1051 err = ubifs_shash_init(c, c->log_hash);
1052 if (err)
1053 goto out;
1054
1055 err = ubifs_shash_update(c, c->log_hash, node, UBIFS_CS_NODE_SZ);
1056 if (err < 0)
1057 goto out;
1058 }
1059
1060 if (snod->sqnum < c->cs_sqnum) {
1061 /*
1062 * This means that we reached end of log and now
1063 * look to the older log data, which was already
1064 * committed but the eraseblock was not erased (UBIFS
1065 * only un-maps it). So this basically means we have to
1066 * exit with "end of log" code.
1067 */
1068 err = 1;
1069 goto out;
1070 }
1071
1072 /* Make sure the first node sits at offset zero of the LEB */
1073 if (snod->offs != 0) {
1074 ubifs_err(c, "first node is not at zero offset");
1075 goto out_dump;
1076 }
1077
1078 list_for_each_entry(snod, &sleb->nodes, list) {
1079 cond_resched();
1080
1081 if (snod->sqnum >= SQNUM_WATERMARK) {
1082 ubifs_err(c, "file system's life ended");
1083 goto out_dump;
1084 }
1085
1086 if (snod->sqnum < c->cs_sqnum) {
1087 ubifs_err(c, "bad sqnum %llu, commit sqnum %llu",
1088 snod->sqnum, c->cs_sqnum);
1089 goto out_dump;
1090 }
1091
1092 if (snod->sqnum > c->max_sqnum)
1093 c->max_sqnum = snod->sqnum;
1094
1095 switch (snod->type) {
1096 case UBIFS_REF_NODE: {
1097 const struct ubifs_ref_node *ref = snod->node;
1098
1099 err = validate_ref(c, ref);
1100 if (err == 1)
1101 break; /* Already have this bud */
1102 if (err)
1103 goto out_dump;
1104
1105 err = ubifs_shash_update(c, c->log_hash, ref,
1106 UBIFS_REF_NODE_SZ);
1107 if (err)
1108 goto out;
1109
1110 err = add_replay_bud(c, le32_to_cpu(ref->lnum),
1111 le32_to_cpu(ref->offs),
1112 le32_to_cpu(ref->jhead),
1113 snod->sqnum);
1114 if (err)
1115 goto out;
1116
1117 break;
1118 }
1119 case UBIFS_CS_NODE:
1120 /* Make sure it sits at the beginning of LEB */
1121 if (snod->offs != 0) {
1122 ubifs_err(c, "unexpected node in log");
1123 goto out_dump;
1124 }
1125 break;
1126 default:
1127 ubifs_err(c, "unexpected node in log");
1128 goto out_dump;
1129 }
1130 }
1131
1132 if (sleb->endpt || c->lhead_offs >= c->leb_size) {
1133 c->lhead_lnum = lnum;
1134 c->lhead_offs = sleb->endpt;
1135 }
1136
1137 err = !sleb->endpt;
1138out:
1139 ubifs_scan_destroy(sleb);
1140 return err;
1141
1142out_dump:
1143 ubifs_err(c, "log error detected while replaying the log at LEB %d:%d",
1144 lnum, offs + snod->offs);
1145 ubifs_dump_node(c, snod->node);
1146 ubifs_scan_destroy(sleb);
1147 return -EINVAL;
1148}
1149
1150/**
1151 * take_ihead - update the status of the index head in lprops to 'taken'.
1152 * @c: UBIFS file-system description object
1153 *
1154 * This function returns the amount of free space in the index head LEB or a
1155 * negative error code.
1156 */
1157static int take_ihead(struct ubifs_info *c)
1158{
1159 const struct ubifs_lprops *lp;
1160 int err, free;
1161
1162 ubifs_get_lprops(c);
1163
1164 lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
1165 if (IS_ERR(lp)) {
1166 err = PTR_ERR(lp);
1167 goto out;
1168 }
1169
1170 free = lp->free;
1171
1172 lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
1173 lp->flags | LPROPS_TAKEN, 0);
1174 if (IS_ERR(lp)) {
1175 err = PTR_ERR(lp);
1176 goto out;
1177 }
1178
1179 err = free;
1180out:
1181 ubifs_release_lprops(c);
1182 return err;
1183}
1184
1185/**
1186 * ubifs_replay_journal - replay journal.
1187 * @c: UBIFS file-system description object
1188 *
1189 * This function scans the journal, replays and cleans it up. It makes sure all
1190 * memory data structures related to uncommitted journal are built (dirty TNC
1191 * tree, tree of buds, modified lprops, etc).
1192 */
1193int ubifs_replay_journal(struct ubifs_info *c)
1194{
1195 int err, lnum, free;
1196
1197 BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
1198
1199 /* Update the status of the index head in lprops to 'taken' */
1200 free = take_ihead(c);
1201 if (free < 0)
1202 return free; /* Error code */
1203
1204 if (c->ihead_offs != c->leb_size - free) {
1205 ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum,
1206 c->ihead_offs);
1207 return -EINVAL;
1208 }
1209
1210 dbg_mnt("start replaying the journal");
1211 c->replaying = 1;
1212 lnum = c->ltail_lnum = c->lhead_lnum;
1213
1214 do {
1215 err = replay_log_leb(c, lnum, 0, c->sbuf);
1216 if (err == 1) {
1217 if (lnum != c->lhead_lnum)
1218 /* We hit the end of the log */
1219 break;
1220
1221 /*
1222 * The head of the log must always start with the
1223 * "commit start" node on a properly formatted UBIFS.
1224 * But we found no nodes at all, which means that
1225 * something went wrong and we cannot proceed mounting
1226 * the file-system.
1227 */
1228 ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted",
1229 lnum, 0);
1230 err = -EINVAL;
1231 }
1232 if (err)
1233 goto out;
1234 lnum = ubifs_next_log_lnum(c, lnum);
1235 } while (lnum != c->ltail_lnum);
1236
1237 err = replay_buds(c);
1238 if (err)
1239 goto out;
1240
1241 err = apply_replay_list(c);
1242 if (err)
1243 goto out;
1244
1245 err = set_buds_lprops(c);
1246 if (err)
1247 goto out;
1248
1249 /*
1250 * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
1251 * to roughly estimate index growth. Things like @c->bi.min_idx_lebs
1252 * depend on it. This means we have to initialize it to make sure
1253 * budgeting works properly.
1254 */
1255 c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
1256 c->bi.uncommitted_idx *= c->max_idx_node_sz;
1257
1258 ubifs_assert(c, c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
1259 dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu",
1260 c->lhead_lnum, c->lhead_offs, c->max_sqnum,
1261 (unsigned long)c->highest_inum);
1262out:
1263 destroy_replay_list(c);
1264 destroy_bud_list(c);
1265 c->replaying = 0;
1266 return err;
1267}