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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 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}
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}