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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 no commit in between. 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 key_type(c, &r->key) == UBIFS_INO_KEY)
228 return r->deletion == 0;
229
230 }
231
232 ubifs_assert(c, 0);
233 return false;
234}
235
236/**
237 * apply_replay_entry - apply a replay entry to the TNC.
238 * @c: UBIFS file-system description object
239 * @r: replay entry to apply
240 *
241 * Apply a replay entry to the TNC.
242 */
243static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
244{
245 int err;
246
247 dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ",
248 r->lnum, r->offs, r->len, r->deletion, r->sqnum);
249
250 if (is_hash_key(c, &r->key)) {
251 if (r->deletion)
252 err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
253 else
254 err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
255 r->len, r->hash, &r->nm);
256 } else {
257 if (r->deletion)
258 switch (key_type(c, &r->key)) {
259 case UBIFS_INO_KEY:
260 {
261 ino_t inum = key_inum(c, &r->key);
262
263 if (inode_still_linked(c, r)) {
264 err = 0;
265 break;
266 }
267
268 err = ubifs_tnc_remove_ino(c, inum);
269 break;
270 }
271 case UBIFS_TRUN_KEY:
272 err = trun_remove_range(c, r);
273 break;
274 default:
275 err = ubifs_tnc_remove(c, &r->key);
276 break;
277 }
278 else
279 err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
280 r->len, r->hash);
281 if (err)
282 return err;
283
284 if (c->need_recovery)
285 err = ubifs_recover_size_accum(c, &r->key, r->deletion,
286 r->new_size);
287 }
288
289 return err;
290}
291
292/**
293 * replay_entries_cmp - compare 2 replay entries.
294 * @priv: UBIFS file-system description object
295 * @a: first replay entry
296 * @b: second replay entry
297 *
298 * This is a comparios function for 'list_sort()' which compares 2 replay
299 * entries @a and @b by comparing their sequence number. Returns %1 if @a has
300 * greater sequence number and %-1 otherwise.
301 */
302static int replay_entries_cmp(void *priv, const struct list_head *a,
303 const struct list_head *b)
304{
305 struct ubifs_info *c = priv;
306 struct replay_entry *ra, *rb;
307
308 cond_resched();
309 if (a == b)
310 return 0;
311
312 ra = list_entry(a, struct replay_entry, list);
313 rb = list_entry(b, struct replay_entry, list);
314 ubifs_assert(c, ra->sqnum != rb->sqnum);
315 if (ra->sqnum > rb->sqnum)
316 return 1;
317 return -1;
318}
319
320/**
321 * apply_replay_list - apply the replay list to the TNC.
322 * @c: UBIFS file-system description object
323 *
324 * Apply all entries in the replay list to the TNC. Returns zero in case of
325 * success and a negative error code in case of failure.
326 */
327static int apply_replay_list(struct ubifs_info *c)
328{
329 struct replay_entry *r;
330 int err;
331
332 list_sort(c, &c->replay_list, &replay_entries_cmp);
333
334 list_for_each_entry(r, &c->replay_list, list) {
335 cond_resched();
336
337 err = apply_replay_entry(c, r);
338 if (err)
339 return err;
340 }
341
342 return 0;
343}
344
345/**
346 * destroy_replay_list - destroy the replay.
347 * @c: UBIFS file-system description object
348 *
349 * Destroy the replay list.
350 */
351static void destroy_replay_list(struct ubifs_info *c)
352{
353 struct replay_entry *r, *tmp;
354
355 list_for_each_entry_safe(r, tmp, &c->replay_list, list) {
356 if (is_hash_key(c, &r->key))
357 kfree(fname_name(&r->nm));
358 list_del(&r->list);
359 kfree(r);
360 }
361}
362
363/**
364 * insert_node - insert a node to the replay list
365 * @c: UBIFS file-system description object
366 * @lnum: node logical eraseblock number
367 * @offs: node offset
368 * @len: node length
369 * @key: node key
370 * @sqnum: sequence number
371 * @deletion: non-zero if this is a deletion
372 * @used: number of bytes in use in a LEB
373 * @old_size: truncation old size
374 * @new_size: truncation new size
375 *
376 * This function inserts a scanned non-direntry node to the replay list. The
377 * replay list contains @struct replay_entry elements, and we sort this list in
378 * sequence number order before applying it. The replay list is applied at the
379 * very end of the replay process. Since the list is sorted in sequence number
380 * order, the older modifications are applied first. This function returns zero
381 * in case of success and a negative error code in case of failure.
382 */
383static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
384 const u8 *hash, union ubifs_key *key,
385 unsigned long long sqnum, int deletion, int *used,
386 loff_t old_size, loff_t new_size)
387{
388 struct replay_entry *r;
389
390 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
391
392 if (key_inum(c, key) >= c->highest_inum)
393 c->highest_inum = key_inum(c, key);
394
395 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
396 if (!r)
397 return -ENOMEM;
398
399 if (!deletion)
400 *used += ALIGN(len, 8);
401 r->lnum = lnum;
402 r->offs = offs;
403 r->len = len;
404 ubifs_copy_hash(c, hash, r->hash);
405 r->deletion = !!deletion;
406 r->sqnum = sqnum;
407 key_copy(c, key, &r->key);
408 r->old_size = old_size;
409 r->new_size = new_size;
410
411 list_add_tail(&r->list, &c->replay_list);
412 return 0;
413}
414
415/**
416 * insert_dent - insert a directory entry node into the replay list.
417 * @c: UBIFS file-system description object
418 * @lnum: node logical eraseblock number
419 * @offs: node offset
420 * @len: node length
421 * @key: node key
422 * @name: directory entry name
423 * @nlen: directory entry name length
424 * @sqnum: sequence number
425 * @deletion: non-zero if this is a deletion
426 * @used: number of bytes in use in a LEB
427 *
428 * This function inserts a scanned directory entry node or an extended
429 * attribute entry to the replay list. Returns zero in case of success and a
430 * negative error code in case of failure.
431 */
432static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
433 const u8 *hash, union ubifs_key *key,
434 const char *name, int nlen, unsigned long long sqnum,
435 int deletion, int *used)
436{
437 struct replay_entry *r;
438 char *nbuf;
439
440 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
441 if (key_inum(c, key) >= c->highest_inum)
442 c->highest_inum = key_inum(c, key);
443
444 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
445 if (!r)
446 return -ENOMEM;
447
448 nbuf = kmalloc(nlen + 1, GFP_KERNEL);
449 if (!nbuf) {
450 kfree(r);
451 return -ENOMEM;
452 }
453
454 if (!deletion)
455 *used += ALIGN(len, 8);
456 r->lnum = lnum;
457 r->offs = offs;
458 r->len = len;
459 ubifs_copy_hash(c, hash, r->hash);
460 r->deletion = !!deletion;
461 r->sqnum = sqnum;
462 key_copy(c, key, &r->key);
463 fname_len(&r->nm) = nlen;
464 memcpy(nbuf, name, nlen);
465 nbuf[nlen] = '\0';
466 fname_name(&r->nm) = nbuf;
467
468 list_add_tail(&r->list, &c->replay_list);
469 return 0;
470}
471
472/**
473 * ubifs_validate_entry - validate directory or extended attribute entry node.
474 * @c: UBIFS file-system description object
475 * @dent: the node to validate
476 *
477 * This function validates directory or extended attribute entry node @dent.
478 * Returns zero if the node is all right and a %-EINVAL if not.
479 */
480int ubifs_validate_entry(struct ubifs_info *c,
481 const struct ubifs_dent_node *dent)
482{
483 int key_type = key_type_flash(c, dent->key);
484 int nlen = le16_to_cpu(dent->nlen);
485
486 if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
487 dent->type >= UBIFS_ITYPES_CNT ||
488 nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
489 (key_type == UBIFS_XENT_KEY && strnlen(dent->name, nlen) != nlen) ||
490 le64_to_cpu(dent->inum) > MAX_INUM) {
491 ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ?
492 "directory entry" : "extended attribute entry");
493 return -EINVAL;
494 }
495
496 if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
497 ubifs_err(c, "bad key type %d", key_type);
498 return -EINVAL;
499 }
500
501 return 0;
502}
503
504/**
505 * is_last_bud - check if the bud is the last in the journal head.
506 * @c: UBIFS file-system description object
507 * @bud: bud description object
508 *
509 * This function checks if bud @bud is the last bud in its journal head. This
510 * information is then used by 'replay_bud()' to decide whether the bud can
511 * have corruptions or not. Indeed, only last buds can be corrupted by power
512 * cuts. Returns %1 if this is the last bud, and %0 if not.
513 */
514static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
515{
516 struct ubifs_jhead *jh = &c->jheads[bud->jhead];
517 struct ubifs_bud *next;
518 uint32_t data;
519 int err;
520
521 if (list_is_last(&bud->list, &jh->buds_list))
522 return 1;
523
524 /*
525 * The following is a quirk to make sure we work correctly with UBIFS
526 * images used with older UBIFS.
527 *
528 * Normally, the last bud will be the last in the journal head's list
529 * of bud. However, there is one exception if the UBIFS image belongs
530 * to older UBIFS. This is fairly unlikely: one would need to use old
531 * UBIFS, then have a power cut exactly at the right point, and then
532 * try to mount this image with new UBIFS.
533 *
534 * The exception is: it is possible to have 2 buds A and B, A goes
535 * before B, and B is the last, bud B is contains no data, and bud A is
536 * corrupted at the end. The reason is that in older versions when the
537 * journal code switched the next bud (from A to B), it first added a
538 * log reference node for the new bud (B), and only after this it
539 * synchronized the write-buffer of current bud (A). But later this was
540 * changed and UBIFS started to always synchronize the write-buffer of
541 * the bud (A) before writing the log reference for the new bud (B).
542 *
543 * But because older UBIFS always synchronized A's write-buffer before
544 * writing to B, we can recognize this exceptional situation but
545 * checking the contents of bud B - if it is empty, then A can be
546 * treated as the last and we can recover it.
547 *
548 * TODO: remove this piece of code in a couple of years (today it is
549 * 16.05.2011).
550 */
551 next = list_entry(bud->list.next, struct ubifs_bud, list);
552 if (!list_is_last(&next->list, &jh->buds_list))
553 return 0;
554
555 err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1);
556 if (err)
557 return 0;
558
559 return data == 0xFFFFFFFF;
560}
561
562/* authenticate_sleb_hash is split out for stack usage */
563static int noinline_for_stack
564authenticate_sleb_hash(struct ubifs_info *c,
565 struct shash_desc *log_hash, u8 *hash)
566{
567 SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
568
569 hash_desc->tfm = c->hash_tfm;
570
571 ubifs_shash_copy_state(c, log_hash, hash_desc);
572 return crypto_shash_final(hash_desc, hash);
573}
574
575/**
576 * authenticate_sleb - authenticate one scan LEB
577 * @c: UBIFS file-system description object
578 * @sleb: the scan LEB to authenticate
579 * @log_hash:
580 * @is_last: if true, this is the last LEB
581 *
582 * This function iterates over the buds of a single LEB authenticating all buds
583 * with the authentication nodes on this LEB. Authentication nodes are written
584 * after some buds and contain a HMAC covering the authentication node itself
585 * and the buds between the last authentication node and the current
586 * authentication node. It can happen that the last buds cannot be authenticated
587 * because a powercut happened when some nodes were written but not the
588 * corresponding authentication node. This function returns the number of nodes
589 * that could be authenticated or a negative error code.
590 */
591static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
592 struct shash_desc *log_hash, int is_last)
593{
594 int n_not_auth = 0;
595 struct ubifs_scan_node *snod;
596 int n_nodes = 0;
597 int err;
598 u8 hash[UBIFS_HASH_ARR_SZ];
599 u8 hmac[UBIFS_HMAC_ARR_SZ];
600
601 if (!ubifs_authenticated(c))
602 return sleb->nodes_cnt;
603
604 list_for_each_entry(snod, &sleb->nodes, list) {
605
606 n_nodes++;
607
608 if (snod->type == UBIFS_AUTH_NODE) {
609 struct ubifs_auth_node *auth = snod->node;
610
611 err = authenticate_sleb_hash(c, log_hash, hash);
612 if (err)
613 goto out;
614
615 err = crypto_shash_tfm_digest(c->hmac_tfm, hash,
616 c->hash_len, hmac);
617 if (err)
618 goto out;
619
620 err = ubifs_check_hmac(c, auth->hmac, hmac);
621 if (err) {
622 err = -EPERM;
623 goto out;
624 }
625 n_not_auth = 0;
626 } else {
627 err = crypto_shash_update(log_hash, snod->node,
628 snod->len);
629 if (err)
630 goto out;
631 n_not_auth++;
632 }
633 }
634
635 /*
636 * A powercut can happen when some nodes were written, but not yet
637 * the corresponding authentication node. This may only happen on
638 * the last bud though.
639 */
640 if (n_not_auth) {
641 if (is_last) {
642 dbg_mnt("%d unauthenticated nodes found on LEB %d, Ignoring them",
643 n_not_auth, sleb->lnum);
644 err = 0;
645 } else {
646 dbg_mnt("%d unauthenticated nodes found on non-last LEB %d",
647 n_not_auth, sleb->lnum);
648 err = -EPERM;
649 }
650 } else {
651 err = 0;
652 }
653out:
654 return err ? err : n_nodes - n_not_auth;
655}
656
657/**
658 * replay_bud - replay a bud logical eraseblock.
659 * @c: UBIFS file-system description object
660 * @b: bud entry which describes the bud
661 *
662 * This function replays bud @bud, recovers it if needed, and adds all nodes
663 * from this bud to the replay list. Returns zero in case of success and a
664 * negative error code in case of failure.
665 */
666static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
667{
668 int is_last = is_last_bud(c, b->bud);
669 int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start;
670 int n_nodes, n = 0;
671 struct ubifs_scan_leb *sleb;
672 struct ubifs_scan_node *snod;
673
674 dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d",
675 lnum, b->bud->jhead, offs, is_last);
676
677 if (c->need_recovery && is_last)
678 /*
679 * Recover only last LEBs in the journal heads, because power
680 * cuts may cause corruptions only in these LEBs, because only
681 * these LEBs could possibly be written to at the power cut
682 * time.
683 */
684 sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead);
685 else
686 sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0);
687 if (IS_ERR(sleb))
688 return PTR_ERR(sleb);
689
690 n_nodes = authenticate_sleb(c, sleb, b->bud->log_hash, is_last);
691 if (n_nodes < 0) {
692 err = n_nodes;
693 goto out;
694 }
695
696 ubifs_shash_copy_state(c, b->bud->log_hash,
697 c->jheads[b->bud->jhead].log_hash);
698
699 /*
700 * The bud does not have to start from offset zero - the beginning of
701 * the 'lnum' LEB may contain previously committed data. One of the
702 * things we have to do in replay is to correctly update lprops with
703 * newer information about this LEB.
704 *
705 * At this point lprops thinks that this LEB has 'c->leb_size - offs'
706 * bytes of free space because it only contain information about
707 * committed data.
708 *
709 * But we know that real amount of free space is 'c->leb_size -
710 * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
711 * 'sleb->endpt' is used by bud data. We have to correctly calculate
712 * how much of these data are dirty and update lprops with this
713 * information.
714 *
715 * The dirt in that LEB region is comprised of padding nodes, deletion
716 * nodes, truncation nodes and nodes which are obsoleted by subsequent
717 * nodes in this LEB. So instead of calculating clean space, we
718 * calculate used space ('used' variable).
719 */
720
721 list_for_each_entry(snod, &sleb->nodes, list) {
722 u8 hash[UBIFS_HASH_ARR_SZ];
723 int deletion = 0;
724
725 cond_resched();
726
727 if (snod->sqnum >= SQNUM_WATERMARK) {
728 ubifs_err(c, "file system's life ended");
729 goto out_dump;
730 }
731
732 ubifs_node_calc_hash(c, snod->node, hash);
733
734 if (snod->sqnum > c->max_sqnum)
735 c->max_sqnum = snod->sqnum;
736
737 switch (snod->type) {
738 case UBIFS_INO_NODE:
739 {
740 struct ubifs_ino_node *ino = snod->node;
741 loff_t new_size = le64_to_cpu(ino->size);
742
743 if (le32_to_cpu(ino->nlink) == 0)
744 deletion = 1;
745 err = insert_node(c, lnum, snod->offs, snod->len, hash,
746 &snod->key, snod->sqnum, deletion,
747 &used, 0, new_size);
748 break;
749 }
750 case UBIFS_DATA_NODE:
751 {
752 struct ubifs_data_node *dn = snod->node;
753 loff_t new_size = le32_to_cpu(dn->size) +
754 key_block(c, &snod->key) *
755 UBIFS_BLOCK_SIZE;
756
757 err = insert_node(c, lnum, snod->offs, snod->len, hash,
758 &snod->key, snod->sqnum, deletion,
759 &used, 0, new_size);
760 break;
761 }
762 case UBIFS_DENT_NODE:
763 case UBIFS_XENT_NODE:
764 {
765 struct ubifs_dent_node *dent = snod->node;
766
767 err = ubifs_validate_entry(c, dent);
768 if (err)
769 goto out_dump;
770
771 err = insert_dent(c, lnum, snod->offs, snod->len, hash,
772 &snod->key, dent->name,
773 le16_to_cpu(dent->nlen), snod->sqnum,
774 !le64_to_cpu(dent->inum), &used);
775 break;
776 }
777 case UBIFS_TRUN_NODE:
778 {
779 struct ubifs_trun_node *trun = snod->node;
780 loff_t old_size = le64_to_cpu(trun->old_size);
781 loff_t new_size = le64_to_cpu(trun->new_size);
782 union ubifs_key key;
783
784 /* Validate truncation node */
785 if (old_size < 0 || old_size > c->max_inode_sz ||
786 new_size < 0 || new_size > c->max_inode_sz ||
787 old_size <= new_size) {
788 ubifs_err(c, "bad truncation node");
789 goto out_dump;
790 }
791
792 /*
793 * Create a fake truncation key just to use the same
794 * functions which expect nodes to have keys.
795 */
796 trun_key_init(c, &key, le32_to_cpu(trun->inum));
797 err = insert_node(c, lnum, snod->offs, snod->len, hash,
798 &key, snod->sqnum, 1, &used,
799 old_size, new_size);
800 break;
801 }
802 case UBIFS_AUTH_NODE:
803 break;
804 default:
805 ubifs_err(c, "unexpected node type %d in bud LEB %d:%d",
806 snod->type, lnum, snod->offs);
807 err = -EINVAL;
808 goto out_dump;
809 }
810 if (err)
811 goto out;
812
813 n++;
814 if (n == n_nodes)
815 break;
816 }
817
818 ubifs_assert(c, ubifs_search_bud(c, lnum));
819 ubifs_assert(c, sleb->endpt - offs >= used);
820 ubifs_assert(c, sleb->endpt % c->min_io_size == 0);
821
822 b->dirty = sleb->endpt - offs - used;
823 b->free = c->leb_size - sleb->endpt;
824 dbg_mnt("bud LEB %d replied: dirty %d, free %d",
825 lnum, b->dirty, b->free);
826
827out:
828 ubifs_scan_destroy(sleb);
829 return err;
830
831out_dump:
832 ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs);
833 ubifs_dump_node(c, snod->node, c->leb_size - snod->offs);
834 ubifs_scan_destroy(sleb);
835 return -EINVAL;
836}
837
838/**
839 * replay_buds - replay all buds.
840 * @c: UBIFS file-system description object
841 *
842 * This function returns zero in case of success and a negative error code in
843 * case of failure.
844 */
845static int replay_buds(struct ubifs_info *c)
846{
847 struct bud_entry *b;
848 int err;
849 unsigned long long prev_sqnum = 0;
850
851 list_for_each_entry(b, &c->replay_buds, list) {
852 err = replay_bud(c, b);
853 if (err)
854 return err;
855
856 ubifs_assert(c, b->sqnum > prev_sqnum);
857 prev_sqnum = b->sqnum;
858 }
859
860 return 0;
861}
862
863/**
864 * destroy_bud_list - destroy the list of buds to replay.
865 * @c: UBIFS file-system description object
866 */
867static void destroy_bud_list(struct ubifs_info *c)
868{
869 struct bud_entry *b;
870
871 while (!list_empty(&c->replay_buds)) {
872 b = list_entry(c->replay_buds.next, struct bud_entry, list);
873 list_del(&b->list);
874 kfree(b);
875 }
876}
877
878/**
879 * add_replay_bud - add a bud to the list of buds to replay.
880 * @c: UBIFS file-system description object
881 * @lnum: bud logical eraseblock number to replay
882 * @offs: bud start offset
883 * @jhead: journal head to which this bud belongs
884 * @sqnum: reference node sequence number
885 *
886 * This function returns zero in case of success and a negative error code in
887 * case of failure.
888 */
889static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
890 unsigned long long sqnum)
891{
892 struct ubifs_bud *bud;
893 struct bud_entry *b;
894 int err;
895
896 dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
897
898 bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
899 if (!bud)
900 return -ENOMEM;
901
902 b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
903 if (!b) {
904 err = -ENOMEM;
905 goto out;
906 }
907
908 bud->lnum = lnum;
909 bud->start = offs;
910 bud->jhead = jhead;
911 bud->log_hash = ubifs_hash_get_desc(c);
912 if (IS_ERR(bud->log_hash)) {
913 err = PTR_ERR(bud->log_hash);
914 goto out;
915 }
916
917 ubifs_shash_copy_state(c, c->log_hash, bud->log_hash);
918
919 ubifs_add_bud(c, bud);
920
921 b->bud = bud;
922 b->sqnum = sqnum;
923 list_add_tail(&b->list, &c->replay_buds);
924
925 return 0;
926out:
927 kfree(bud);
928 kfree(b);
929
930 return err;
931}
932
933/**
934 * validate_ref - validate a reference node.
935 * @c: UBIFS file-system description object
936 * @ref: the reference node to validate
937 *
938 * This function returns %1 if a bud reference already exists for the LEB. %0 is
939 * returned if the reference node is new, otherwise %-EINVAL is returned if
940 * validation failed.
941 */
942static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
943{
944 struct ubifs_bud *bud;
945 int lnum = le32_to_cpu(ref->lnum);
946 unsigned int offs = le32_to_cpu(ref->offs);
947 unsigned int jhead = le32_to_cpu(ref->jhead);
948
949 /*
950 * ref->offs may point to the end of LEB when the journal head points
951 * to the end of LEB and we write reference node for it during commit.
952 * So this is why we require 'offs > c->leb_size'.
953 */
954 if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
955 lnum < c->main_first || offs > c->leb_size ||
956 offs & (c->min_io_size - 1))
957 return -EINVAL;
958
959 /* Make sure we have not already looked at this bud */
960 bud = ubifs_search_bud(c, lnum);
961 if (bud) {
962 if (bud->jhead == jhead && bud->start <= offs)
963 return 1;
964 ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs);
965 return -EINVAL;
966 }
967
968 return 0;
969}
970
971/**
972 * replay_log_leb - replay a log logical eraseblock.
973 * @c: UBIFS file-system description object
974 * @lnum: log logical eraseblock to replay
975 * @offs: offset to start replaying from
976 * @sbuf: scan buffer
977 *
978 * This function replays a log LEB and returns zero in case of success, %1 if
979 * this is the last LEB in the log, and a negative error code in case of
980 * failure.
981 */
982static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
983{
984 int err;
985 struct ubifs_scan_leb *sleb;
986 struct ubifs_scan_node *snod;
987 const struct ubifs_cs_node *node;
988
989 dbg_mnt("replay log LEB %d:%d", lnum, offs);
990 sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery);
991 if (IS_ERR(sleb)) {
992 if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
993 return PTR_ERR(sleb);
994 /*
995 * Note, the below function will recover this log LEB only if
996 * it is the last, because unclean reboots can possibly corrupt
997 * only the tail of the log.
998 */
999 sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
1000 if (IS_ERR(sleb))
1001 return PTR_ERR(sleb);
1002 }
1003
1004 if (sleb->nodes_cnt == 0) {
1005 err = 1;
1006 goto out;
1007 }
1008
1009 node = sleb->buf;
1010 snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
1011 if (c->cs_sqnum == 0) {
1012 /*
1013 * This is the first log LEB we are looking at, make sure that
1014 * the first node is a commit start node. Also record its
1015 * sequence number so that UBIFS can determine where the log
1016 * ends, because all nodes which were have higher sequence
1017 * numbers.
1018 */
1019 if (snod->type != UBIFS_CS_NODE) {
1020 ubifs_err(c, "first log node at LEB %d:%d is not CS node",
1021 lnum, offs);
1022 goto out_dump;
1023 }
1024 if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
1025 ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu",
1026 lnum, offs,
1027 (unsigned long long)le64_to_cpu(node->cmt_no),
1028 c->cmt_no);
1029 goto out_dump;
1030 }
1031
1032 c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
1033 dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
1034
1035 err = ubifs_shash_init(c, c->log_hash);
1036 if (err)
1037 goto out;
1038
1039 err = ubifs_shash_update(c, c->log_hash, node, UBIFS_CS_NODE_SZ);
1040 if (err < 0)
1041 goto out;
1042 }
1043
1044 if (snod->sqnum < c->cs_sqnum) {
1045 /*
1046 * This means that we reached end of log and now
1047 * look to the older log data, which was already
1048 * committed but the eraseblock was not erased (UBIFS
1049 * only un-maps it). So this basically means we have to
1050 * exit with "end of log" code.
1051 */
1052 err = 1;
1053 goto out;
1054 }
1055
1056 /* Make sure the first node sits at offset zero of the LEB */
1057 if (snod->offs != 0) {
1058 ubifs_err(c, "first node is not at zero offset");
1059 goto out_dump;
1060 }
1061
1062 list_for_each_entry(snod, &sleb->nodes, list) {
1063 cond_resched();
1064
1065 if (snod->sqnum >= SQNUM_WATERMARK) {
1066 ubifs_err(c, "file system's life ended");
1067 goto out_dump;
1068 }
1069
1070 if (snod->sqnum < c->cs_sqnum) {
1071 ubifs_err(c, "bad sqnum %llu, commit sqnum %llu",
1072 snod->sqnum, c->cs_sqnum);
1073 goto out_dump;
1074 }
1075
1076 if (snod->sqnum > c->max_sqnum)
1077 c->max_sqnum = snod->sqnum;
1078
1079 switch (snod->type) {
1080 case UBIFS_REF_NODE: {
1081 const struct ubifs_ref_node *ref = snod->node;
1082
1083 err = validate_ref(c, ref);
1084 if (err == 1)
1085 break; /* Already have this bud */
1086 if (err)
1087 goto out_dump;
1088
1089 err = ubifs_shash_update(c, c->log_hash, ref,
1090 UBIFS_REF_NODE_SZ);
1091 if (err)
1092 goto out;
1093
1094 err = add_replay_bud(c, le32_to_cpu(ref->lnum),
1095 le32_to_cpu(ref->offs),
1096 le32_to_cpu(ref->jhead),
1097 snod->sqnum);
1098 if (err)
1099 goto out;
1100
1101 break;
1102 }
1103 case UBIFS_CS_NODE:
1104 /* Make sure it sits at the beginning of LEB */
1105 if (snod->offs != 0) {
1106 ubifs_err(c, "unexpected node in log");
1107 goto out_dump;
1108 }
1109 break;
1110 default:
1111 ubifs_err(c, "unexpected node in log");
1112 goto out_dump;
1113 }
1114 }
1115
1116 if (sleb->endpt || c->lhead_offs >= c->leb_size) {
1117 c->lhead_lnum = lnum;
1118 c->lhead_offs = sleb->endpt;
1119 }
1120
1121 err = !sleb->endpt;
1122out:
1123 ubifs_scan_destroy(sleb);
1124 return err;
1125
1126out_dump:
1127 ubifs_err(c, "log error detected while replaying the log at LEB %d:%d",
1128 lnum, offs + snod->offs);
1129 ubifs_dump_node(c, snod->node, c->leb_size - snod->offs);
1130 ubifs_scan_destroy(sleb);
1131 return -EINVAL;
1132}
1133
1134/**
1135 * take_ihead - update the status of the index head in lprops to 'taken'.
1136 * @c: UBIFS file-system description object
1137 *
1138 * This function returns the amount of free space in the index head LEB or a
1139 * negative error code.
1140 */
1141static int take_ihead(struct ubifs_info *c)
1142{
1143 const struct ubifs_lprops *lp;
1144 int err, free;
1145
1146 ubifs_get_lprops(c);
1147
1148 lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
1149 if (IS_ERR(lp)) {
1150 err = PTR_ERR(lp);
1151 goto out;
1152 }
1153
1154 free = lp->free;
1155
1156 lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
1157 lp->flags | LPROPS_TAKEN, 0);
1158 if (IS_ERR(lp)) {
1159 err = PTR_ERR(lp);
1160 goto out;
1161 }
1162
1163 err = free;
1164out:
1165 ubifs_release_lprops(c);
1166 return err;
1167}
1168
1169/**
1170 * ubifs_replay_journal - replay journal.
1171 * @c: UBIFS file-system description object
1172 *
1173 * This function scans the journal, replays and cleans it up. It makes sure all
1174 * memory data structures related to uncommitted journal are built (dirty TNC
1175 * tree, tree of buds, modified lprops, etc).
1176 */
1177int ubifs_replay_journal(struct ubifs_info *c)
1178{
1179 int err, lnum, free;
1180
1181 BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
1182
1183 /* Update the status of the index head in lprops to 'taken' */
1184 free = take_ihead(c);
1185 if (free < 0)
1186 return free; /* Error code */
1187
1188 if (c->ihead_offs != c->leb_size - free) {
1189 ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum,
1190 c->ihead_offs);
1191 return -EINVAL;
1192 }
1193
1194 dbg_mnt("start replaying the journal");
1195 c->replaying = 1;
1196 lnum = c->ltail_lnum = c->lhead_lnum;
1197
1198 do {
1199 err = replay_log_leb(c, lnum, 0, c->sbuf);
1200 if (err == 1) {
1201 if (lnum != c->lhead_lnum)
1202 /* We hit the end of the log */
1203 break;
1204
1205 /*
1206 * The head of the log must always start with the
1207 * "commit start" node on a properly formatted UBIFS.
1208 * But we found no nodes at all, which means that
1209 * something went wrong and we cannot proceed mounting
1210 * the file-system.
1211 */
1212 ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted",
1213 lnum, 0);
1214 err = -EINVAL;
1215 }
1216 if (err)
1217 goto out;
1218 lnum = ubifs_next_log_lnum(c, lnum);
1219 } while (lnum != c->ltail_lnum);
1220
1221 err = replay_buds(c);
1222 if (err)
1223 goto out;
1224
1225 err = apply_replay_list(c);
1226 if (err)
1227 goto out;
1228
1229 err = set_buds_lprops(c);
1230 if (err)
1231 goto out;
1232
1233 /*
1234 * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
1235 * to roughly estimate index growth. Things like @c->bi.min_idx_lebs
1236 * depend on it. This means we have to initialize it to make sure
1237 * budgeting works properly.
1238 */
1239 c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
1240 c->bi.uncommitted_idx *= c->max_idx_node_sz;
1241
1242 ubifs_assert(c, c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
1243 dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu",
1244 c->lhead_lnum, c->lhead_offs, c->max_sqnum,
1245 (unsigned long)c->highest_inum);
1246out:
1247 destroy_replay_list(c);
1248 destroy_bud_list(c);
1249 c->replaying = 0;
1250 return err;
1251}
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
27/**
28 * struct replay_entry - replay list entry.
29 * @lnum: logical eraseblock number of the node
30 * @offs: node offset
31 * @len: node length
32 * @hash: node hash
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 no commit in between. 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 key_type(c, &r->key) == UBIFS_INO_KEY)
228 return r->deletion == 0;
229
230 }
231
232 ubifs_assert(c, 0);
233 return false;
234}
235
236/**
237 * apply_replay_entry - apply a replay entry to the TNC.
238 * @c: UBIFS file-system description object
239 * @r: replay entry to apply
240 *
241 * Apply a replay entry to the TNC.
242 */
243static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
244{
245 int err;
246
247 dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ",
248 r->lnum, r->offs, r->len, r->deletion, r->sqnum);
249
250 if (is_hash_key(c, &r->key)) {
251 if (r->deletion)
252 err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
253 else
254 err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
255 r->len, r->hash, &r->nm);
256 } else {
257 if (r->deletion)
258 switch (key_type(c, &r->key)) {
259 case UBIFS_INO_KEY:
260 {
261 ino_t inum = key_inum(c, &r->key);
262
263 if (inode_still_linked(c, r)) {
264 err = 0;
265 break;
266 }
267
268 err = ubifs_tnc_remove_ino(c, inum);
269 break;
270 }
271 case UBIFS_TRUN_KEY:
272 err = trun_remove_range(c, r);
273 break;
274 default:
275 err = ubifs_tnc_remove(c, &r->key);
276 break;
277 }
278 else
279 err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
280 r->len, r->hash);
281 if (err)
282 return err;
283
284 if (c->need_recovery)
285 err = ubifs_recover_size_accum(c, &r->key, r->deletion,
286 r->new_size);
287 }
288
289 return err;
290}
291
292/**
293 * replay_entries_cmp - compare 2 replay entries.
294 * @priv: UBIFS file-system description object
295 * @a: first replay entry
296 * @b: second replay entry
297 *
298 * This is a comparios function for 'list_sort()' which compares 2 replay
299 * entries @a and @b by comparing their sequence number. Returns %1 if @a has
300 * greater sequence number and %-1 otherwise.
301 */
302static int replay_entries_cmp(void *priv, const struct list_head *a,
303 const struct list_head *b)
304{
305 struct ubifs_info *c = priv;
306 struct replay_entry *ra, *rb;
307
308 cond_resched();
309 if (a == b)
310 return 0;
311
312 ra = list_entry(a, struct replay_entry, list);
313 rb = list_entry(b, struct replay_entry, list);
314 ubifs_assert(c, ra->sqnum != rb->sqnum);
315 if (ra->sqnum > rb->sqnum)
316 return 1;
317 return -1;
318}
319
320/**
321 * apply_replay_list - apply the replay list to the TNC.
322 * @c: UBIFS file-system description object
323 *
324 * Apply all entries in the replay list to the TNC. Returns zero in case of
325 * success and a negative error code in case of failure.
326 */
327static int apply_replay_list(struct ubifs_info *c)
328{
329 struct replay_entry *r;
330 int err;
331
332 list_sort(c, &c->replay_list, &replay_entries_cmp);
333
334 list_for_each_entry(r, &c->replay_list, list) {
335 cond_resched();
336
337 err = apply_replay_entry(c, r);
338 if (err)
339 return err;
340 }
341
342 return 0;
343}
344
345/**
346 * destroy_replay_list - destroy the replay.
347 * @c: UBIFS file-system description object
348 *
349 * Destroy the replay list.
350 */
351static void destroy_replay_list(struct ubifs_info *c)
352{
353 struct replay_entry *r, *tmp;
354
355 list_for_each_entry_safe(r, tmp, &c->replay_list, list) {
356 if (is_hash_key(c, &r->key))
357 kfree(fname_name(&r->nm));
358 list_del(&r->list);
359 kfree(r);
360 }
361}
362
363/**
364 * insert_node - insert a node to the replay list
365 * @c: UBIFS file-system description object
366 * @lnum: node logical eraseblock number
367 * @offs: node offset
368 * @len: node length
369 * @hash: node hash
370 * @key: node key
371 * @sqnum: sequence number
372 * @deletion: non-zero if this is a deletion
373 * @used: number of bytes in use in a LEB
374 * @old_size: truncation old size
375 * @new_size: truncation new size
376 *
377 * This function inserts a scanned non-direntry node to the replay list. The
378 * replay list contains @struct replay_entry elements, and we sort this list in
379 * sequence number order before applying it. The replay list is applied at the
380 * very end of the replay process. Since the list is sorted in sequence number
381 * order, the older modifications are applied first. This function returns zero
382 * in case of success and a negative error code in case of failure.
383 */
384static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
385 const u8 *hash, union ubifs_key *key,
386 unsigned long long sqnum, int deletion, int *used,
387 loff_t old_size, loff_t new_size)
388{
389 struct replay_entry *r;
390
391 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
392
393 if (key_inum(c, key) >= c->highest_inum)
394 c->highest_inum = key_inum(c, key);
395
396 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
397 if (!r)
398 return -ENOMEM;
399
400 if (!deletion)
401 *used += ALIGN(len, 8);
402 r->lnum = lnum;
403 r->offs = offs;
404 r->len = len;
405 ubifs_copy_hash(c, hash, r->hash);
406 r->deletion = !!deletion;
407 r->sqnum = sqnum;
408 key_copy(c, key, &r->key);
409 r->old_size = old_size;
410 r->new_size = new_size;
411
412 list_add_tail(&r->list, &c->replay_list);
413 return 0;
414}
415
416/**
417 * insert_dent - insert a directory entry node into the replay list.
418 * @c: UBIFS file-system description object
419 * @lnum: node logical eraseblock number
420 * @offs: node offset
421 * @len: node length
422 * @hash: node hash
423 * @key: node key
424 * @name: directory entry name
425 * @nlen: directory entry name length
426 * @sqnum: sequence number
427 * @deletion: non-zero if this is a deletion
428 * @used: number of bytes in use in a LEB
429 *
430 * This function inserts a scanned directory entry node or an extended
431 * attribute entry to the replay list. Returns zero in case of success and a
432 * negative error code in case of failure.
433 */
434static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
435 const u8 *hash, union ubifs_key *key,
436 const char *name, int nlen, unsigned long long sqnum,
437 int deletion, int *used)
438{
439 struct replay_entry *r;
440 char *nbuf;
441
442 dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
443 if (key_inum(c, key) >= c->highest_inum)
444 c->highest_inum = key_inum(c, key);
445
446 r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
447 if (!r)
448 return -ENOMEM;
449
450 nbuf = kmalloc(nlen + 1, GFP_KERNEL);
451 if (!nbuf) {
452 kfree(r);
453 return -ENOMEM;
454 }
455
456 if (!deletion)
457 *used += ALIGN(len, 8);
458 r->lnum = lnum;
459 r->offs = offs;
460 r->len = len;
461 ubifs_copy_hash(c, hash, r->hash);
462 r->deletion = !!deletion;
463 r->sqnum = sqnum;
464 key_copy(c, key, &r->key);
465 fname_len(&r->nm) = nlen;
466 memcpy(nbuf, name, nlen);
467 nbuf[nlen] = '\0';
468 fname_name(&r->nm) = nbuf;
469
470 list_add_tail(&r->list, &c->replay_list);
471 return 0;
472}
473
474/**
475 * ubifs_validate_entry - validate directory or extended attribute entry node.
476 * @c: UBIFS file-system description object
477 * @dent: the node to validate
478 *
479 * This function validates directory or extended attribute entry node @dent.
480 * Returns zero if the node is all right and a %-EINVAL if not.
481 */
482int ubifs_validate_entry(struct ubifs_info *c,
483 const struct ubifs_dent_node *dent)
484{
485 int key_type = key_type_flash(c, dent->key);
486 int nlen = le16_to_cpu(dent->nlen);
487
488 if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
489 dent->type >= UBIFS_ITYPES_CNT ||
490 nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
491 (key_type == UBIFS_XENT_KEY && strnlen(dent->name, nlen) != nlen) ||
492 le64_to_cpu(dent->inum) > MAX_INUM) {
493 ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ?
494 "directory entry" : "extended attribute entry");
495 return -EINVAL;
496 }
497
498 if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
499 ubifs_err(c, "bad key type %d", key_type);
500 return -EINVAL;
501 }
502
503 return 0;
504}
505
506/**
507 * is_last_bud - check if the bud is the last in the journal head.
508 * @c: UBIFS file-system description object
509 * @bud: bud description object
510 *
511 * This function checks if bud @bud is the last bud in its journal head. This
512 * information is then used by 'replay_bud()' to decide whether the bud can
513 * have corruptions or not. Indeed, only last buds can be corrupted by power
514 * cuts. Returns %1 if this is the last bud, and %0 if not.
515 */
516static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
517{
518 struct ubifs_jhead *jh = &c->jheads[bud->jhead];
519 struct ubifs_bud *next;
520 uint32_t data;
521 int err;
522
523 if (list_is_last(&bud->list, &jh->buds_list))
524 return 1;
525
526 /*
527 * The following is a quirk to make sure we work correctly with UBIFS
528 * images used with older UBIFS.
529 *
530 * Normally, the last bud will be the last in the journal head's list
531 * of bud. However, there is one exception if the UBIFS image belongs
532 * to older UBIFS. This is fairly unlikely: one would need to use old
533 * UBIFS, then have a power cut exactly at the right point, and then
534 * try to mount this image with new UBIFS.
535 *
536 * The exception is: it is possible to have 2 buds A and B, A goes
537 * before B, and B is the last, bud B is contains no data, and bud A is
538 * corrupted at the end. The reason is that in older versions when the
539 * journal code switched the next bud (from A to B), it first added a
540 * log reference node for the new bud (B), and only after this it
541 * synchronized the write-buffer of current bud (A). But later this was
542 * changed and UBIFS started to always synchronize the write-buffer of
543 * the bud (A) before writing the log reference for the new bud (B).
544 *
545 * But because older UBIFS always synchronized A's write-buffer before
546 * writing to B, we can recognize this exceptional situation but
547 * checking the contents of bud B - if it is empty, then A can be
548 * treated as the last and we can recover it.
549 *
550 * TODO: remove this piece of code in a couple of years (today it is
551 * 16.05.2011).
552 */
553 next = list_entry(bud->list.next, struct ubifs_bud, list);
554 if (!list_is_last(&next->list, &jh->buds_list))
555 return 0;
556
557 err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1);
558 if (err)
559 return 0;
560
561 return data == 0xFFFFFFFF;
562}
563
564/* authenticate_sleb_hash is split out for stack usage */
565static int noinline_for_stack
566authenticate_sleb_hash(struct ubifs_info *c,
567 struct shash_desc *log_hash, u8 *hash)
568{
569 SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
570
571 hash_desc->tfm = c->hash_tfm;
572
573 ubifs_shash_copy_state(c, log_hash, hash_desc);
574 return crypto_shash_final(hash_desc, hash);
575}
576
577/**
578 * authenticate_sleb - authenticate one scan LEB
579 * @c: UBIFS file-system description object
580 * @sleb: the scan LEB to authenticate
581 * @log_hash:
582 * @is_last: if true, this is the last LEB
583 *
584 * This function iterates over the buds of a single LEB authenticating all buds
585 * with the authentication nodes on this LEB. Authentication nodes are written
586 * after some buds and contain a HMAC covering the authentication node itself
587 * and the buds between the last authentication node and the current
588 * authentication node. It can happen that the last buds cannot be authenticated
589 * because a powercut happened when some nodes were written but not the
590 * corresponding authentication node. This function returns the number of nodes
591 * that could be authenticated or a negative error code.
592 */
593static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
594 struct shash_desc *log_hash, int is_last)
595{
596 int n_not_auth = 0;
597 struct ubifs_scan_node *snod;
598 int n_nodes = 0;
599 int err;
600 u8 hash[UBIFS_HASH_ARR_SZ];
601 u8 hmac[UBIFS_HMAC_ARR_SZ];
602
603 if (!ubifs_authenticated(c))
604 return sleb->nodes_cnt;
605
606 list_for_each_entry(snod, &sleb->nodes, list) {
607
608 n_nodes++;
609
610 if (snod->type == UBIFS_AUTH_NODE) {
611 struct ubifs_auth_node *auth = snod->node;
612
613 err = authenticate_sleb_hash(c, log_hash, hash);
614 if (err)
615 goto out;
616
617 err = crypto_shash_tfm_digest(c->hmac_tfm, hash,
618 c->hash_len, hmac);
619 if (err)
620 goto out;
621
622 err = ubifs_check_hmac(c, auth->hmac, hmac);
623 if (err) {
624 err = -EPERM;
625 goto out;
626 }
627 n_not_auth = 0;
628 } else {
629 err = crypto_shash_update(log_hash, snod->node,
630 snod->len);
631 if (err)
632 goto out;
633 n_not_auth++;
634 }
635 }
636
637 /*
638 * A powercut can happen when some nodes were written, but not yet
639 * the corresponding authentication node. This may only happen on
640 * the last bud though.
641 */
642 if (n_not_auth) {
643 if (is_last) {
644 dbg_mnt("%d unauthenticated nodes found on LEB %d, Ignoring them",
645 n_not_auth, sleb->lnum);
646 err = 0;
647 } else {
648 dbg_mnt("%d unauthenticated nodes found on non-last LEB %d",
649 n_not_auth, sleb->lnum);
650 err = -EPERM;
651 }
652 } else {
653 err = 0;
654 }
655out:
656 return err ? err : n_nodes - n_not_auth;
657}
658
659/**
660 * replay_bud - replay a bud logical eraseblock.
661 * @c: UBIFS file-system description object
662 * @b: bud entry which describes the bud
663 *
664 * This function replays bud @bud, recovers it if needed, and adds all nodes
665 * from this bud to the replay list. Returns zero in case of success and a
666 * negative error code in case of failure.
667 */
668static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
669{
670 int is_last = is_last_bud(c, b->bud);
671 int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start;
672 int n_nodes, n = 0;
673 struct ubifs_scan_leb *sleb;
674 struct ubifs_scan_node *snod;
675
676 dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d",
677 lnum, b->bud->jhead, offs, is_last);
678
679 if (c->need_recovery && is_last)
680 /*
681 * Recover only last LEBs in the journal heads, because power
682 * cuts may cause corruptions only in these LEBs, because only
683 * these LEBs could possibly be written to at the power cut
684 * time.
685 */
686 sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead);
687 else
688 sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0);
689 if (IS_ERR(sleb))
690 return PTR_ERR(sleb);
691
692 n_nodes = authenticate_sleb(c, sleb, b->bud->log_hash, is_last);
693 if (n_nodes < 0) {
694 err = n_nodes;
695 goto out;
696 }
697
698 ubifs_shash_copy_state(c, b->bud->log_hash,
699 c->jheads[b->bud->jhead].log_hash);
700
701 /*
702 * The bud does not have to start from offset zero - the beginning of
703 * the 'lnum' LEB may contain previously committed data. One of the
704 * things we have to do in replay is to correctly update lprops with
705 * newer information about this LEB.
706 *
707 * At this point lprops thinks that this LEB has 'c->leb_size - offs'
708 * bytes of free space because it only contain information about
709 * committed data.
710 *
711 * But we know that real amount of free space is 'c->leb_size -
712 * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
713 * 'sleb->endpt' is used by bud data. We have to correctly calculate
714 * how much of these data are dirty and update lprops with this
715 * information.
716 *
717 * The dirt in that LEB region is comprised of padding nodes, deletion
718 * nodes, truncation nodes and nodes which are obsoleted by subsequent
719 * nodes in this LEB. So instead of calculating clean space, we
720 * calculate used space ('used' variable).
721 */
722
723 list_for_each_entry(snod, &sleb->nodes, list) {
724 u8 hash[UBIFS_HASH_ARR_SZ];
725 int deletion = 0;
726
727 cond_resched();
728
729 if (snod->sqnum >= SQNUM_WATERMARK) {
730 ubifs_err(c, "file system's life ended");
731 goto out_dump;
732 }
733
734 ubifs_node_calc_hash(c, snod->node, hash);
735
736 if (snod->sqnum > c->max_sqnum)
737 c->max_sqnum = snod->sqnum;
738
739 switch (snod->type) {
740 case UBIFS_INO_NODE:
741 {
742 struct ubifs_ino_node *ino = snod->node;
743 loff_t new_size = le64_to_cpu(ino->size);
744
745 if (le32_to_cpu(ino->nlink) == 0)
746 deletion = 1;
747 err = insert_node(c, lnum, snod->offs, snod->len, hash,
748 &snod->key, snod->sqnum, deletion,
749 &used, 0, new_size);
750 break;
751 }
752 case UBIFS_DATA_NODE:
753 {
754 struct ubifs_data_node *dn = snod->node;
755 loff_t new_size = le32_to_cpu(dn->size) +
756 key_block(c, &snod->key) *
757 UBIFS_BLOCK_SIZE;
758
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_DENT_NODE:
765 case UBIFS_XENT_NODE:
766 {
767 struct ubifs_dent_node *dent = snod->node;
768
769 err = ubifs_validate_entry(c, dent);
770 if (err)
771 goto out_dump;
772
773 err = insert_dent(c, lnum, snod->offs, snod->len, hash,
774 &snod->key, dent->name,
775 le16_to_cpu(dent->nlen), snod->sqnum,
776 !le64_to_cpu(dent->inum), &used);
777 break;
778 }
779 case UBIFS_TRUN_NODE:
780 {
781 struct ubifs_trun_node *trun = snod->node;
782 loff_t old_size = le64_to_cpu(trun->old_size);
783 loff_t new_size = le64_to_cpu(trun->new_size);
784 union ubifs_key key;
785
786 /* Validate truncation node */
787 if (old_size < 0 || old_size > c->max_inode_sz ||
788 new_size < 0 || new_size > c->max_inode_sz ||
789 old_size <= new_size) {
790 ubifs_err(c, "bad truncation node");
791 goto out_dump;
792 }
793
794 /*
795 * Create a fake truncation key just to use the same
796 * functions which expect nodes to have keys.
797 */
798 trun_key_init(c, &key, le32_to_cpu(trun->inum));
799 err = insert_node(c, lnum, snod->offs, snod->len, hash,
800 &key, snod->sqnum, 1, &used,
801 old_size, new_size);
802 break;
803 }
804 case UBIFS_AUTH_NODE:
805 break;
806 default:
807 ubifs_err(c, "unexpected node type %d in bud LEB %d:%d",
808 snod->type, lnum, snod->offs);
809 err = -EINVAL;
810 goto out_dump;
811 }
812 if (err)
813 goto out;
814
815 n++;
816 if (n == n_nodes)
817 break;
818 }
819
820 ubifs_assert(c, ubifs_search_bud(c, lnum));
821 ubifs_assert(c, sleb->endpt - offs >= used);
822 ubifs_assert(c, sleb->endpt % c->min_io_size == 0);
823
824 b->dirty = sleb->endpt - offs - used;
825 b->free = c->leb_size - sleb->endpt;
826 dbg_mnt("bud LEB %d replied: dirty %d, free %d",
827 lnum, b->dirty, b->free);
828
829out:
830 ubifs_scan_destroy(sleb);
831 return err;
832
833out_dump:
834 ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs);
835 ubifs_dump_node(c, snod->node, c->leb_size - snod->offs);
836 ubifs_scan_destroy(sleb);
837 return -EINVAL;
838}
839
840/**
841 * replay_buds - replay all buds.
842 * @c: UBIFS file-system description object
843 *
844 * This function returns zero in case of success and a negative error code in
845 * case of failure.
846 */
847static int replay_buds(struct ubifs_info *c)
848{
849 struct bud_entry *b;
850 int err;
851 unsigned long long prev_sqnum = 0;
852
853 list_for_each_entry(b, &c->replay_buds, list) {
854 err = replay_bud(c, b);
855 if (err)
856 return err;
857
858 ubifs_assert(c, b->sqnum > prev_sqnum);
859 prev_sqnum = b->sqnum;
860 }
861
862 return 0;
863}
864
865/**
866 * destroy_bud_list - destroy the list of buds to replay.
867 * @c: UBIFS file-system description object
868 */
869static void destroy_bud_list(struct ubifs_info *c)
870{
871 struct bud_entry *b;
872
873 while (!list_empty(&c->replay_buds)) {
874 b = list_entry(c->replay_buds.next, struct bud_entry, list);
875 list_del(&b->list);
876 kfree(b);
877 }
878}
879
880/**
881 * add_replay_bud - add a bud to the list of buds to replay.
882 * @c: UBIFS file-system description object
883 * @lnum: bud logical eraseblock number to replay
884 * @offs: bud start offset
885 * @jhead: journal head to which this bud belongs
886 * @sqnum: reference node sequence number
887 *
888 * This function returns zero in case of success and a negative error code in
889 * case of failure.
890 */
891static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
892 unsigned long long sqnum)
893{
894 struct ubifs_bud *bud;
895 struct bud_entry *b;
896 int err;
897
898 dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
899
900 bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
901 if (!bud)
902 return -ENOMEM;
903
904 b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
905 if (!b) {
906 err = -ENOMEM;
907 goto out;
908 }
909
910 bud->lnum = lnum;
911 bud->start = offs;
912 bud->jhead = jhead;
913 bud->log_hash = ubifs_hash_get_desc(c);
914 if (IS_ERR(bud->log_hash)) {
915 err = PTR_ERR(bud->log_hash);
916 goto out;
917 }
918
919 ubifs_shash_copy_state(c, c->log_hash, bud->log_hash);
920
921 ubifs_add_bud(c, bud);
922
923 b->bud = bud;
924 b->sqnum = sqnum;
925 list_add_tail(&b->list, &c->replay_buds);
926
927 return 0;
928out:
929 kfree(bud);
930 kfree(b);
931
932 return err;
933}
934
935/**
936 * validate_ref - validate a reference node.
937 * @c: UBIFS file-system description object
938 * @ref: the reference node to validate
939 *
940 * This function returns %1 if a bud reference already exists for the LEB. %0 is
941 * returned if the reference node is new, otherwise %-EINVAL is returned if
942 * validation failed.
943 */
944static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
945{
946 struct ubifs_bud *bud;
947 int lnum = le32_to_cpu(ref->lnum);
948 unsigned int offs = le32_to_cpu(ref->offs);
949 unsigned int jhead = le32_to_cpu(ref->jhead);
950
951 /*
952 * ref->offs may point to the end of LEB when the journal head points
953 * to the end of LEB and we write reference node for it during commit.
954 * So this is why we require 'offs > c->leb_size'.
955 */
956 if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
957 lnum < c->main_first || offs > c->leb_size ||
958 offs & (c->min_io_size - 1))
959 return -EINVAL;
960
961 /* Make sure we have not already looked at this bud */
962 bud = ubifs_search_bud(c, lnum);
963 if (bud) {
964 if (bud->jhead == jhead && bud->start <= offs)
965 return 1;
966 ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs);
967 return -EINVAL;
968 }
969
970 return 0;
971}
972
973/**
974 * replay_log_leb - replay a log logical eraseblock.
975 * @c: UBIFS file-system description object
976 * @lnum: log logical eraseblock to replay
977 * @offs: offset to start replaying from
978 * @sbuf: scan buffer
979 *
980 * This function replays a log LEB and returns zero in case of success, %1 if
981 * this is the last LEB in the log, and a negative error code in case of
982 * failure.
983 */
984static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
985{
986 int err;
987 struct ubifs_scan_leb *sleb;
988 struct ubifs_scan_node *snod;
989 const struct ubifs_cs_node *node;
990
991 dbg_mnt("replay log LEB %d:%d", lnum, offs);
992 sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery);
993 if (IS_ERR(sleb)) {
994 if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
995 return PTR_ERR(sleb);
996 /*
997 * Note, the below function will recover this log LEB only if
998 * it is the last, because unclean reboots can possibly corrupt
999 * only the tail of the log.
1000 */
1001 sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
1002 if (IS_ERR(sleb))
1003 return PTR_ERR(sleb);
1004 }
1005
1006 if (sleb->nodes_cnt == 0) {
1007 err = 1;
1008 goto out;
1009 }
1010
1011 node = sleb->buf;
1012 snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
1013 if (c->cs_sqnum == 0) {
1014 /*
1015 * This is the first log LEB we are looking at, make sure that
1016 * the first node is a commit start node. Also record its
1017 * sequence number so that UBIFS can determine where the log
1018 * ends, because all nodes which were have higher sequence
1019 * numbers.
1020 */
1021 if (snod->type != UBIFS_CS_NODE) {
1022 ubifs_err(c, "first log node at LEB %d:%d is not CS node",
1023 lnum, offs);
1024 goto out_dump;
1025 }
1026 if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
1027 ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu",
1028 lnum, offs,
1029 (unsigned long long)le64_to_cpu(node->cmt_no),
1030 c->cmt_no);
1031 goto out_dump;
1032 }
1033
1034 c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
1035 dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
1036
1037 err = ubifs_shash_init(c, c->log_hash);
1038 if (err)
1039 goto out;
1040
1041 err = ubifs_shash_update(c, c->log_hash, node, UBIFS_CS_NODE_SZ);
1042 if (err < 0)
1043 goto out;
1044 }
1045
1046 if (snod->sqnum < c->cs_sqnum) {
1047 /*
1048 * This means that we reached end of log and now
1049 * look to the older log data, which was already
1050 * committed but the eraseblock was not erased (UBIFS
1051 * only un-maps it). So this basically means we have to
1052 * exit with "end of log" code.
1053 */
1054 err = 1;
1055 goto out;
1056 }
1057
1058 /* Make sure the first node sits at offset zero of the LEB */
1059 if (snod->offs != 0) {
1060 ubifs_err(c, "first node is not at zero offset");
1061 goto out_dump;
1062 }
1063
1064 list_for_each_entry(snod, &sleb->nodes, list) {
1065 cond_resched();
1066
1067 if (snod->sqnum >= SQNUM_WATERMARK) {
1068 ubifs_err(c, "file system's life ended");
1069 goto out_dump;
1070 }
1071
1072 if (snod->sqnum < c->cs_sqnum) {
1073 ubifs_err(c, "bad sqnum %llu, commit sqnum %llu",
1074 snod->sqnum, c->cs_sqnum);
1075 goto out_dump;
1076 }
1077
1078 if (snod->sqnum > c->max_sqnum)
1079 c->max_sqnum = snod->sqnum;
1080
1081 switch (snod->type) {
1082 case UBIFS_REF_NODE: {
1083 const struct ubifs_ref_node *ref = snod->node;
1084
1085 err = validate_ref(c, ref);
1086 if (err == 1)
1087 break; /* Already have this bud */
1088 if (err)
1089 goto out_dump;
1090
1091 err = ubifs_shash_update(c, c->log_hash, ref,
1092 UBIFS_REF_NODE_SZ);
1093 if (err)
1094 goto out;
1095
1096 err = add_replay_bud(c, le32_to_cpu(ref->lnum),
1097 le32_to_cpu(ref->offs),
1098 le32_to_cpu(ref->jhead),
1099 snod->sqnum);
1100 if (err)
1101 goto out;
1102
1103 break;
1104 }
1105 case UBIFS_CS_NODE:
1106 /* Make sure it sits at the beginning of LEB */
1107 if (snod->offs != 0) {
1108 ubifs_err(c, "unexpected node in log");
1109 goto out_dump;
1110 }
1111 break;
1112 default:
1113 ubifs_err(c, "unexpected node in log");
1114 goto out_dump;
1115 }
1116 }
1117
1118 if (sleb->endpt || c->lhead_offs >= c->leb_size) {
1119 c->lhead_lnum = lnum;
1120 c->lhead_offs = sleb->endpt;
1121 }
1122
1123 err = !sleb->endpt;
1124out:
1125 ubifs_scan_destroy(sleb);
1126 return err;
1127
1128out_dump:
1129 ubifs_err(c, "log error detected while replaying the log at LEB %d:%d",
1130 lnum, offs + snod->offs);
1131 ubifs_dump_node(c, snod->node, c->leb_size - snod->offs);
1132 ubifs_scan_destroy(sleb);
1133 return -EINVAL;
1134}
1135
1136/**
1137 * take_ihead - update the status of the index head in lprops to 'taken'.
1138 * @c: UBIFS file-system description object
1139 *
1140 * This function returns the amount of free space in the index head LEB or a
1141 * negative error code.
1142 */
1143static int take_ihead(struct ubifs_info *c)
1144{
1145 const struct ubifs_lprops *lp;
1146 int err, free;
1147
1148 ubifs_get_lprops(c);
1149
1150 lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
1151 if (IS_ERR(lp)) {
1152 err = PTR_ERR(lp);
1153 goto out;
1154 }
1155
1156 free = lp->free;
1157
1158 lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
1159 lp->flags | LPROPS_TAKEN, 0);
1160 if (IS_ERR(lp)) {
1161 err = PTR_ERR(lp);
1162 goto out;
1163 }
1164
1165 err = free;
1166out:
1167 ubifs_release_lprops(c);
1168 return err;
1169}
1170
1171/**
1172 * ubifs_replay_journal - replay journal.
1173 * @c: UBIFS file-system description object
1174 *
1175 * This function scans the journal, replays and cleans it up. It makes sure all
1176 * memory data structures related to uncommitted journal are built (dirty TNC
1177 * tree, tree of buds, modified lprops, etc).
1178 */
1179int ubifs_replay_journal(struct ubifs_info *c)
1180{
1181 int err, lnum, free;
1182
1183 BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
1184
1185 /* Update the status of the index head in lprops to 'taken' */
1186 free = take_ihead(c);
1187 if (free < 0)
1188 return free; /* Error code */
1189
1190 if (c->ihead_offs != c->leb_size - free) {
1191 ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum,
1192 c->ihead_offs);
1193 return -EINVAL;
1194 }
1195
1196 dbg_mnt("start replaying the journal");
1197 c->replaying = 1;
1198 lnum = c->ltail_lnum = c->lhead_lnum;
1199
1200 do {
1201 err = replay_log_leb(c, lnum, 0, c->sbuf);
1202 if (err == 1) {
1203 if (lnum != c->lhead_lnum)
1204 /* We hit the end of the log */
1205 break;
1206
1207 /*
1208 * The head of the log must always start with the
1209 * "commit start" node on a properly formatted UBIFS.
1210 * But we found no nodes at all, which means that
1211 * something went wrong and we cannot proceed mounting
1212 * the file-system.
1213 */
1214 ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted",
1215 lnum, 0);
1216 err = -EINVAL;
1217 }
1218 if (err)
1219 goto out;
1220 lnum = ubifs_next_log_lnum(c, lnum);
1221 } while (lnum != c->ltail_lnum);
1222
1223 err = replay_buds(c);
1224 if (err)
1225 goto out;
1226
1227 err = apply_replay_list(c);
1228 if (err)
1229 goto out;
1230
1231 err = set_buds_lprops(c);
1232 if (err)
1233 goto out;
1234
1235 /*
1236 * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
1237 * to roughly estimate index growth. Things like @c->bi.min_idx_lebs
1238 * depend on it. This means we have to initialize it to make sure
1239 * budgeting works properly.
1240 */
1241 c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
1242 c->bi.uncommitted_idx *= c->max_idx_node_sz;
1243
1244 ubifs_assert(c, c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
1245 dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu",
1246 c->lhead_lnum, c->lhead_offs, c->max_sqnum,
1247 (unsigned long)c->highest_inum);
1248out:
1249 destroy_replay_list(c);
1250 destroy_bud_list(c);
1251 c->replaying = 0;
1252 return err;
1253}