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1/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file implements functions that manage the running of the commit process.
25 * Each affected module has its own functions to accomplish their part in the
26 * commit and those functions are called here.
27 *
28 * The commit is the process whereby all updates to the index and LEB properties
29 * are written out together and the journal becomes empty. This keeps the
30 * file system consistent - at all times the state can be recreated by reading
31 * the index and LEB properties and then replaying the journal.
32 *
33 * The commit is split into two parts named "commit start" and "commit end".
34 * During commit start, the commit process has exclusive access to the journal
35 * by holding the commit semaphore down for writing. As few I/O operations as
36 * possible are performed during commit start, instead the nodes that are to be
37 * written are merely identified. During commit end, the commit semaphore is no
38 * longer held and the journal is again in operation, allowing users to continue
39 * to use the file system while the bulk of the commit I/O is performed. The
40 * purpose of this two-step approach is to prevent the commit from causing any
41 * latency blips. Note that in any case, the commit does not prevent lookups
42 * (as permitted by the TNC mutex), or access to VFS data structures e.g. page
43 * cache.
44 */
45
46#include <linux/freezer.h>
47#include <linux/kthread.h>
48#include <linux/slab.h>
49#include "ubifs.h"
50
51/*
52 * nothing_to_commit - check if there is nothing to commit.
53 * @c: UBIFS file-system description object
54 *
55 * This is a helper function which checks if there is anything to commit. It is
56 * used as an optimization to avoid starting the commit if it is not really
57 * necessary. Indeed, the commit operation always assumes flash I/O (e.g.,
58 * writing the commit start node to the log), and it is better to avoid doing
59 * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is
60 * nothing to commit, it is more optimal to avoid any flash I/O.
61 *
62 * This function has to be called with @c->commit_sem locked for writing -
63 * this function does not take LPT/TNC locks because the @c->commit_sem
64 * guarantees that we have exclusive access to the TNC and LPT data structures.
65 *
66 * This function returns %1 if there is nothing to commit and %0 otherwise.
67 */
68static int nothing_to_commit(struct ubifs_info *c)
69{
70 /*
71 * During mounting or remounting from R/O mode to R/W mode we may
72 * commit for various recovery-related reasons.
73 */
74 if (c->mounting || c->remounting_rw)
75 return 0;
76
77 /*
78 * If the root TNC node is dirty, we definitely have something to
79 * commit.
80 */
81 if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode))
82 return 0;
83
84 /*
85 * Even though the TNC is clean, the LPT tree may have dirty nodes. For
86 * example, this may happen if the budgeting subsystem invoked GC to
87 * make some free space, and the GC found an LEB with only dirty and
88 * free space. In this case GC would just change the lprops of this
89 * LEB (by turning all space into free space) and unmap it.
90 */
91 if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags))
92 return 0;
93
94 ubifs_assert(atomic_long_read(&c->dirty_zn_cnt) == 0);
95 ubifs_assert(c->dirty_pn_cnt == 0);
96 ubifs_assert(c->dirty_nn_cnt == 0);
97
98 return 1;
99}
100
101/**
102 * do_commit - commit the journal.
103 * @c: UBIFS file-system description object
104 *
105 * This function implements UBIFS commit. It has to be called with commit lock
106 * locked. Returns zero in case of success and a negative error code in case of
107 * failure.
108 */
109static int do_commit(struct ubifs_info *c)
110{
111 int err, new_ltail_lnum, old_ltail_lnum, i;
112 struct ubifs_zbranch zroot;
113 struct ubifs_lp_stats lst;
114
115 dbg_cmt("start");
116 ubifs_assert(!c->ro_media && !c->ro_mount);
117
118 if (c->ro_error) {
119 err = -EROFS;
120 goto out_up;
121 }
122
123 if (nothing_to_commit(c)) {
124 up_write(&c->commit_sem);
125 err = 0;
126 goto out_cancel;
127 }
128
129 /* Sync all write buffers (necessary for recovery) */
130 for (i = 0; i < c->jhead_cnt; i++) {
131 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
132 if (err)
133 goto out_up;
134 }
135
136 c->cmt_no += 1;
137 err = ubifs_gc_start_commit(c);
138 if (err)
139 goto out_up;
140 err = dbg_check_lprops(c);
141 if (err)
142 goto out_up;
143 err = ubifs_log_start_commit(c, &new_ltail_lnum);
144 if (err)
145 goto out_up;
146 err = ubifs_tnc_start_commit(c, &zroot);
147 if (err)
148 goto out_up;
149 err = ubifs_lpt_start_commit(c);
150 if (err)
151 goto out_up;
152 err = ubifs_orphan_start_commit(c);
153 if (err)
154 goto out_up;
155
156 ubifs_get_lp_stats(c, &lst);
157
158 up_write(&c->commit_sem);
159
160 err = ubifs_tnc_end_commit(c);
161 if (err)
162 goto out;
163 err = ubifs_lpt_end_commit(c);
164 if (err)
165 goto out;
166 err = ubifs_orphan_end_commit(c);
167 if (err)
168 goto out;
169 old_ltail_lnum = c->ltail_lnum;
170 err = ubifs_log_end_commit(c, new_ltail_lnum);
171 if (err)
172 goto out;
173 err = dbg_check_old_index(c, &zroot);
174 if (err)
175 goto out;
176
177 mutex_lock(&c->mst_mutex);
178 c->mst_node->cmt_no = cpu_to_le64(c->cmt_no);
179 c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum);
180 c->mst_node->root_lnum = cpu_to_le32(zroot.lnum);
181 c->mst_node->root_offs = cpu_to_le32(zroot.offs);
182 c->mst_node->root_len = cpu_to_le32(zroot.len);
183 c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum);
184 c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs);
185 c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz);
186 c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum);
187 c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs);
188 c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum);
189 c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs);
190 c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum);
191 c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs);
192 c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum);
193 c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs);
194 c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum);
195 c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs);
196 c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs);
197 c->mst_node->total_free = cpu_to_le64(lst.total_free);
198 c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
199 c->mst_node->total_used = cpu_to_le64(lst.total_used);
200 c->mst_node->total_dead = cpu_to_le64(lst.total_dead);
201 c->mst_node->total_dark = cpu_to_le64(lst.total_dark);
202 if (c->no_orphs)
203 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
204 else
205 c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
206 err = ubifs_write_master(c);
207 mutex_unlock(&c->mst_mutex);
208 if (err)
209 goto out;
210
211 err = ubifs_log_post_commit(c, old_ltail_lnum);
212 if (err)
213 goto out;
214 err = ubifs_gc_end_commit(c);
215 if (err)
216 goto out;
217 err = ubifs_lpt_post_commit(c);
218 if (err)
219 goto out;
220
221out_cancel:
222 spin_lock(&c->cs_lock);
223 c->cmt_state = COMMIT_RESTING;
224 wake_up(&c->cmt_wq);
225 dbg_cmt("commit end");
226 spin_unlock(&c->cs_lock);
227 return 0;
228
229out_up:
230 up_write(&c->commit_sem);
231out:
232 ubifs_err("commit failed, error %d", err);
233 spin_lock(&c->cs_lock);
234 c->cmt_state = COMMIT_BROKEN;
235 wake_up(&c->cmt_wq);
236 spin_unlock(&c->cs_lock);
237 ubifs_ro_mode(c, err);
238 return err;
239}
240
241/**
242 * run_bg_commit - run background commit if it is needed.
243 * @c: UBIFS file-system description object
244 *
245 * This function runs background commit if it is needed. Returns zero in case
246 * of success and a negative error code in case of failure.
247 */
248static int run_bg_commit(struct ubifs_info *c)
249{
250 spin_lock(&c->cs_lock);
251 /*
252 * Run background commit only if background commit was requested or if
253 * commit is required.
254 */
255 if (c->cmt_state != COMMIT_BACKGROUND &&
256 c->cmt_state != COMMIT_REQUIRED)
257 goto out;
258 spin_unlock(&c->cs_lock);
259
260 down_write(&c->commit_sem);
261 spin_lock(&c->cs_lock);
262 if (c->cmt_state == COMMIT_REQUIRED)
263 c->cmt_state = COMMIT_RUNNING_REQUIRED;
264 else if (c->cmt_state == COMMIT_BACKGROUND)
265 c->cmt_state = COMMIT_RUNNING_BACKGROUND;
266 else
267 goto out_cmt_unlock;
268 spin_unlock(&c->cs_lock);
269
270 return do_commit(c);
271
272out_cmt_unlock:
273 up_write(&c->commit_sem);
274out:
275 spin_unlock(&c->cs_lock);
276 return 0;
277}
278
279/**
280 * ubifs_bg_thread - UBIFS background thread function.
281 * @info: points to the file-system description object
282 *
283 * This function implements various file-system background activities:
284 * o when a write-buffer timer expires it synchronizes the appropriate
285 * write-buffer;
286 * o when the journal is about to be full, it starts in-advance commit.
287 *
288 * Note, other stuff like background garbage collection may be added here in
289 * future.
290 */
291int ubifs_bg_thread(void *info)
292{
293 int err;
294 struct ubifs_info *c = info;
295
296 dbg_msg("background thread \"%s\" started, PID %d",
297 c->bgt_name, current->pid);
298 set_freezable();
299
300 while (1) {
301 if (kthread_should_stop())
302 break;
303
304 if (try_to_freeze())
305 continue;
306
307 set_current_state(TASK_INTERRUPTIBLE);
308 /* Check if there is something to do */
309 if (!c->need_bgt) {
310 /*
311 * Nothing prevents us from going sleep now and
312 * be never woken up and block the task which
313 * could wait in 'kthread_stop()' forever.
314 */
315 if (kthread_should_stop())
316 break;
317 schedule();
318 continue;
319 } else
320 __set_current_state(TASK_RUNNING);
321
322 c->need_bgt = 0;
323 err = ubifs_bg_wbufs_sync(c);
324 if (err)
325 ubifs_ro_mode(c, err);
326
327 run_bg_commit(c);
328 cond_resched();
329 }
330
331 dbg_msg("background thread \"%s\" stops", c->bgt_name);
332 return 0;
333}
334
335/**
336 * ubifs_commit_required - set commit state to "required".
337 * @c: UBIFS file-system description object
338 *
339 * This function is called if a commit is required but cannot be done from the
340 * calling function, so it is just flagged instead.
341 */
342void ubifs_commit_required(struct ubifs_info *c)
343{
344 spin_lock(&c->cs_lock);
345 switch (c->cmt_state) {
346 case COMMIT_RESTING:
347 case COMMIT_BACKGROUND:
348 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
349 dbg_cstate(COMMIT_REQUIRED));
350 c->cmt_state = COMMIT_REQUIRED;
351 break;
352 case COMMIT_RUNNING_BACKGROUND:
353 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
354 dbg_cstate(COMMIT_RUNNING_REQUIRED));
355 c->cmt_state = COMMIT_RUNNING_REQUIRED;
356 break;
357 case COMMIT_REQUIRED:
358 case COMMIT_RUNNING_REQUIRED:
359 case COMMIT_BROKEN:
360 break;
361 }
362 spin_unlock(&c->cs_lock);
363}
364
365/**
366 * ubifs_request_bg_commit - notify the background thread to do a commit.
367 * @c: UBIFS file-system description object
368 *
369 * This function is called if the journal is full enough to make a commit
370 * worthwhile, so background thread is kicked to start it.
371 */
372void ubifs_request_bg_commit(struct ubifs_info *c)
373{
374 spin_lock(&c->cs_lock);
375 if (c->cmt_state == COMMIT_RESTING) {
376 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
377 dbg_cstate(COMMIT_BACKGROUND));
378 c->cmt_state = COMMIT_BACKGROUND;
379 spin_unlock(&c->cs_lock);
380 ubifs_wake_up_bgt(c);
381 } else
382 spin_unlock(&c->cs_lock);
383}
384
385/**
386 * wait_for_commit - wait for commit.
387 * @c: UBIFS file-system description object
388 *
389 * This function sleeps until the commit operation is no longer running.
390 */
391static int wait_for_commit(struct ubifs_info *c)
392{
393 dbg_cmt("pid %d goes sleep", current->pid);
394
395 /*
396 * The following sleeps if the condition is false, and will be woken
397 * when the commit ends. It is possible, although very unlikely, that we
398 * will wake up and see the subsequent commit running, rather than the
399 * one we were waiting for, and go back to sleep. However, we will be
400 * woken again, so there is no danger of sleeping forever.
401 */
402 wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
403 c->cmt_state != COMMIT_RUNNING_REQUIRED);
404 dbg_cmt("commit finished, pid %d woke up", current->pid);
405 return 0;
406}
407
408/**
409 * ubifs_run_commit - run or wait for commit.
410 * @c: UBIFS file-system description object
411 *
412 * This function runs commit and returns zero in case of success and a negative
413 * error code in case of failure.
414 */
415int ubifs_run_commit(struct ubifs_info *c)
416{
417 int err = 0;
418
419 spin_lock(&c->cs_lock);
420 if (c->cmt_state == COMMIT_BROKEN) {
421 err = -EROFS;
422 goto out;
423 }
424
425 if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
426 /*
427 * We set the commit state to 'running required' to indicate
428 * that we want it to complete as quickly as possible.
429 */
430 c->cmt_state = COMMIT_RUNNING_REQUIRED;
431
432 if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
433 spin_unlock(&c->cs_lock);
434 return wait_for_commit(c);
435 }
436 spin_unlock(&c->cs_lock);
437
438 /* Ok, the commit is indeed needed */
439
440 down_write(&c->commit_sem);
441 spin_lock(&c->cs_lock);
442 /*
443 * Since we unlocked 'c->cs_lock', the state may have changed, so
444 * re-check it.
445 */
446 if (c->cmt_state == COMMIT_BROKEN) {
447 err = -EROFS;
448 goto out_cmt_unlock;
449 }
450
451 if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
452 c->cmt_state = COMMIT_RUNNING_REQUIRED;
453
454 if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
455 up_write(&c->commit_sem);
456 spin_unlock(&c->cs_lock);
457 return wait_for_commit(c);
458 }
459 c->cmt_state = COMMIT_RUNNING_REQUIRED;
460 spin_unlock(&c->cs_lock);
461
462 err = do_commit(c);
463 return err;
464
465out_cmt_unlock:
466 up_write(&c->commit_sem);
467out:
468 spin_unlock(&c->cs_lock);
469 return err;
470}
471
472/**
473 * ubifs_gc_should_commit - determine if it is time for GC to run commit.
474 * @c: UBIFS file-system description object
475 *
476 * This function is called by garbage collection to determine if commit should
477 * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
478 * is full enough to start commit, this function returns true. It is not
479 * absolutely necessary to commit yet, but it feels like this should be better
480 * then to keep doing GC. This function returns %1 if GC has to initiate commit
481 * and %0 if not.
482 */
483int ubifs_gc_should_commit(struct ubifs_info *c)
484{
485 int ret = 0;
486
487 spin_lock(&c->cs_lock);
488 if (c->cmt_state == COMMIT_BACKGROUND) {
489 dbg_cmt("commit required now");
490 c->cmt_state = COMMIT_REQUIRED;
491 } else
492 dbg_cmt("commit not requested");
493 if (c->cmt_state == COMMIT_REQUIRED)
494 ret = 1;
495 spin_unlock(&c->cs_lock);
496 return ret;
497}
498
499#ifdef CONFIG_UBIFS_FS_DEBUG
500
501/**
502 * struct idx_node - hold index nodes during index tree traversal.
503 * @list: list
504 * @iip: index in parent (slot number of this indexing node in the parent
505 * indexing node)
506 * @upper_key: all keys in this indexing node have to be less or equivalent to
507 * this key
508 * @idx: index node (8-byte aligned because all node structures must be 8-byte
509 * aligned)
510 */
511struct idx_node {
512 struct list_head list;
513 int iip;
514 union ubifs_key upper_key;
515 struct ubifs_idx_node idx __attribute__((aligned(8)));
516};
517
518/**
519 * dbg_old_index_check_init - get information for the next old index check.
520 * @c: UBIFS file-system description object
521 * @zroot: root of the index
522 *
523 * This function records information about the index that will be needed for the
524 * next old index check i.e. 'dbg_check_old_index()'.
525 *
526 * This function returns %0 on success and a negative error code on failure.
527 */
528int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
529{
530 struct ubifs_idx_node *idx;
531 int lnum, offs, len, err = 0;
532 struct ubifs_debug_info *d = c->dbg;
533
534 d->old_zroot = *zroot;
535 lnum = d->old_zroot.lnum;
536 offs = d->old_zroot.offs;
537 len = d->old_zroot.len;
538
539 idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
540 if (!idx)
541 return -ENOMEM;
542
543 err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
544 if (err)
545 goto out;
546
547 d->old_zroot_level = le16_to_cpu(idx->level);
548 d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
549out:
550 kfree(idx);
551 return err;
552}
553
554/**
555 * dbg_check_old_index - check the old copy of the index.
556 * @c: UBIFS file-system description object
557 * @zroot: root of the new index
558 *
559 * In order to be able to recover from an unclean unmount, a complete copy of
560 * the index must exist on flash. This is the "old" index. The commit process
561 * must write the "new" index to flash without overwriting or destroying any
562 * part of the old index. This function is run at commit end in order to check
563 * that the old index does indeed exist completely intact.
564 *
565 * This function returns %0 on success and a negative error code on failure.
566 */
567int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
568{
569 int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
570 int first = 1, iip;
571 struct ubifs_debug_info *d = c->dbg;
572 union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key;
573 unsigned long long uninitialized_var(last_sqnum);
574 struct ubifs_idx_node *idx;
575 struct list_head list;
576 struct idx_node *i;
577 size_t sz;
578
579 if (!dbg_is_chk_index(c))
580 return 0;
581
582 INIT_LIST_HEAD(&list);
583
584 sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
585 UBIFS_IDX_NODE_SZ;
586
587 /* Start at the old zroot */
588 lnum = d->old_zroot.lnum;
589 offs = d->old_zroot.offs;
590 len = d->old_zroot.len;
591 iip = 0;
592
593 /*
594 * Traverse the index tree preorder depth-first i.e. do a node and then
595 * its subtrees from left to right.
596 */
597 while (1) {
598 struct ubifs_branch *br;
599
600 /* Get the next index node */
601 i = kmalloc(sz, GFP_NOFS);
602 if (!i) {
603 err = -ENOMEM;
604 goto out_free;
605 }
606 i->iip = iip;
607 /* Keep the index nodes on our path in a linked list */
608 list_add_tail(&i->list, &list);
609 /* Read the index node */
610 idx = &i->idx;
611 err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
612 if (err)
613 goto out_free;
614 /* Validate index node */
615 child_cnt = le16_to_cpu(idx->child_cnt);
616 if (child_cnt < 1 || child_cnt > c->fanout) {
617 err = 1;
618 goto out_dump;
619 }
620 if (first) {
621 first = 0;
622 /* Check root level and sqnum */
623 if (le16_to_cpu(idx->level) != d->old_zroot_level) {
624 err = 2;
625 goto out_dump;
626 }
627 if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) {
628 err = 3;
629 goto out_dump;
630 }
631 /* Set last values as though root had a parent */
632 last_level = le16_to_cpu(idx->level) + 1;
633 last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
634 key_read(c, ubifs_idx_key(c, idx), &lower_key);
635 highest_ino_key(c, &upper_key, INUM_WATERMARK);
636 }
637 key_copy(c, &upper_key, &i->upper_key);
638 if (le16_to_cpu(idx->level) != last_level - 1) {
639 err = 3;
640 goto out_dump;
641 }
642 /*
643 * The index is always written bottom up hence a child's sqnum
644 * is always less than the parents.
645 */
646 if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
647 err = 4;
648 goto out_dump;
649 }
650 /* Check key range */
651 key_read(c, ubifs_idx_key(c, idx), &l_key);
652 br = ubifs_idx_branch(c, idx, child_cnt - 1);
653 key_read(c, &br->key, &u_key);
654 if (keys_cmp(c, &lower_key, &l_key) > 0) {
655 err = 5;
656 goto out_dump;
657 }
658 if (keys_cmp(c, &upper_key, &u_key) < 0) {
659 err = 6;
660 goto out_dump;
661 }
662 if (keys_cmp(c, &upper_key, &u_key) == 0)
663 if (!is_hash_key(c, &u_key)) {
664 err = 7;
665 goto out_dump;
666 }
667 /* Go to next index node */
668 if (le16_to_cpu(idx->level) == 0) {
669 /* At the bottom, so go up until can go right */
670 while (1) {
671 /* Drop the bottom of the list */
672 list_del(&i->list);
673 kfree(i);
674 /* No more list means we are done */
675 if (list_empty(&list))
676 goto out;
677 /* Look at the new bottom */
678 i = list_entry(list.prev, struct idx_node,
679 list);
680 idx = &i->idx;
681 /* Can we go right */
682 if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
683 iip = iip + 1;
684 break;
685 } else
686 /* Nope, so go up again */
687 iip = i->iip;
688 }
689 } else
690 /* Go down left */
691 iip = 0;
692 /*
693 * We have the parent in 'idx' and now we set up for reading the
694 * child pointed to by slot 'iip'.
695 */
696 last_level = le16_to_cpu(idx->level);
697 last_sqnum = le64_to_cpu(idx->ch.sqnum);
698 br = ubifs_idx_branch(c, idx, iip);
699 lnum = le32_to_cpu(br->lnum);
700 offs = le32_to_cpu(br->offs);
701 len = le32_to_cpu(br->len);
702 key_read(c, &br->key, &lower_key);
703 if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
704 br = ubifs_idx_branch(c, idx, iip + 1);
705 key_read(c, &br->key, &upper_key);
706 } else
707 key_copy(c, &i->upper_key, &upper_key);
708 }
709out:
710 err = dbg_old_index_check_init(c, zroot);
711 if (err)
712 goto out_free;
713
714 return 0;
715
716out_dump:
717 dbg_err("dumping index node (iip=%d)", i->iip);
718 dbg_dump_node(c, idx);
719 list_del(&i->list);
720 kfree(i);
721 if (!list_empty(&list)) {
722 i = list_entry(list.prev, struct idx_node, list);
723 dbg_err("dumping parent index node");
724 dbg_dump_node(c, &i->idx);
725 }
726out_free:
727 while (!list_empty(&list)) {
728 i = list_entry(list.next, struct idx_node, list);
729 list_del(&i->list);
730 kfree(i);
731 }
732 ubifs_err("failed, error %d", err);
733 if (err > 0)
734 err = -EINVAL;
735 return err;
736}
737
738#endif /* CONFIG_UBIFS_FS_DEBUG */
1/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file implements functions that manage the running of the commit process.
25 * Each affected module has its own functions to accomplish their part in the
26 * commit and those functions are called here.
27 *
28 * The commit is the process whereby all updates to the index and LEB properties
29 * are written out together and the journal becomes empty. This keeps the
30 * file system consistent - at all times the state can be recreated by reading
31 * the index and LEB properties and then replaying the journal.
32 *
33 * The commit is split into two parts named "commit start" and "commit end".
34 * During commit start, the commit process has exclusive access to the journal
35 * by holding the commit semaphore down for writing. As few I/O operations as
36 * possible are performed during commit start, instead the nodes that are to be
37 * written are merely identified. During commit end, the commit semaphore is no
38 * longer held and the journal is again in operation, allowing users to continue
39 * to use the file system while the bulk of the commit I/O is performed. The
40 * purpose of this two-step approach is to prevent the commit from causing any
41 * latency blips. Note that in any case, the commit does not prevent lookups
42 * (as permitted by the TNC mutex), or access to VFS data structures e.g. page
43 * cache.
44 */
45
46#include <linux/freezer.h>
47#include <linux/kthread.h>
48#include <linux/slab.h>
49#include "ubifs.h"
50
51/*
52 * nothing_to_commit - check if there is nothing to commit.
53 * @c: UBIFS file-system description object
54 *
55 * This is a helper function which checks if there is anything to commit. It is
56 * used as an optimization to avoid starting the commit if it is not really
57 * necessary. Indeed, the commit operation always assumes flash I/O (e.g.,
58 * writing the commit start node to the log), and it is better to avoid doing
59 * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is
60 * nothing to commit, it is more optimal to avoid any flash I/O.
61 *
62 * This function has to be called with @c->commit_sem locked for writing -
63 * this function does not take LPT/TNC locks because the @c->commit_sem
64 * guarantees that we have exclusive access to the TNC and LPT data structures.
65 *
66 * This function returns %1 if there is nothing to commit and %0 otherwise.
67 */
68static int nothing_to_commit(struct ubifs_info *c)
69{
70 /*
71 * During mounting or remounting from R/O mode to R/W mode we may
72 * commit for various recovery-related reasons.
73 */
74 if (c->mounting || c->remounting_rw)
75 return 0;
76
77 /*
78 * If the root TNC node is dirty, we definitely have something to
79 * commit.
80 */
81 if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode))
82 return 0;
83
84 /*
85 * Even though the TNC is clean, the LPT tree may have dirty nodes. For
86 * example, this may happen if the budgeting subsystem invoked GC to
87 * make some free space, and the GC found an LEB with only dirty and
88 * free space. In this case GC would just change the lprops of this
89 * LEB (by turning all space into free space) and unmap it.
90 */
91 if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags))
92 return 0;
93
94 ubifs_assert(atomic_long_read(&c->dirty_zn_cnt) == 0);
95 ubifs_assert(c->dirty_pn_cnt == 0);
96 ubifs_assert(c->dirty_nn_cnt == 0);
97
98 return 1;
99}
100
101/**
102 * do_commit - commit the journal.
103 * @c: UBIFS file-system description object
104 *
105 * This function implements UBIFS commit. It has to be called with commit lock
106 * locked. Returns zero in case of success and a negative error code in case of
107 * failure.
108 */
109static int do_commit(struct ubifs_info *c)
110{
111 int err, new_ltail_lnum, old_ltail_lnum, i;
112 struct ubifs_zbranch zroot;
113 struct ubifs_lp_stats lst;
114
115 dbg_cmt("start");
116 ubifs_assert(!c->ro_media && !c->ro_mount);
117
118 if (c->ro_error) {
119 err = -EROFS;
120 goto out_up;
121 }
122
123 if (nothing_to_commit(c)) {
124 up_write(&c->commit_sem);
125 err = 0;
126 goto out_cancel;
127 }
128
129 /* Sync all write buffers (necessary for recovery) */
130 for (i = 0; i < c->jhead_cnt; i++) {
131 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
132 if (err)
133 goto out_up;
134 }
135
136 c->cmt_no += 1;
137 err = ubifs_gc_start_commit(c);
138 if (err)
139 goto out_up;
140 err = dbg_check_lprops(c);
141 if (err)
142 goto out_up;
143 err = ubifs_log_start_commit(c, &new_ltail_lnum);
144 if (err)
145 goto out_up;
146 err = ubifs_tnc_start_commit(c, &zroot);
147 if (err)
148 goto out_up;
149 err = ubifs_lpt_start_commit(c);
150 if (err)
151 goto out_up;
152 err = ubifs_orphan_start_commit(c);
153 if (err)
154 goto out_up;
155
156 ubifs_get_lp_stats(c, &lst);
157
158 up_write(&c->commit_sem);
159
160 err = ubifs_tnc_end_commit(c);
161 if (err)
162 goto out;
163 err = ubifs_lpt_end_commit(c);
164 if (err)
165 goto out;
166 err = ubifs_orphan_end_commit(c);
167 if (err)
168 goto out;
169 old_ltail_lnum = c->ltail_lnum;
170 err = ubifs_log_end_commit(c, new_ltail_lnum);
171 if (err)
172 goto out;
173 err = dbg_check_old_index(c, &zroot);
174 if (err)
175 goto out;
176
177 mutex_lock(&c->mst_mutex);
178 c->mst_node->cmt_no = cpu_to_le64(c->cmt_no);
179 c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum);
180 c->mst_node->root_lnum = cpu_to_le32(zroot.lnum);
181 c->mst_node->root_offs = cpu_to_le32(zroot.offs);
182 c->mst_node->root_len = cpu_to_le32(zroot.len);
183 c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum);
184 c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs);
185 c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz);
186 c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum);
187 c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs);
188 c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum);
189 c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs);
190 c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum);
191 c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs);
192 c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum);
193 c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs);
194 c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum);
195 c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs);
196 c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs);
197 c->mst_node->total_free = cpu_to_le64(lst.total_free);
198 c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
199 c->mst_node->total_used = cpu_to_le64(lst.total_used);
200 c->mst_node->total_dead = cpu_to_le64(lst.total_dead);
201 c->mst_node->total_dark = cpu_to_le64(lst.total_dark);
202 if (c->no_orphs)
203 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
204 else
205 c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
206 err = ubifs_write_master(c);
207 mutex_unlock(&c->mst_mutex);
208 if (err)
209 goto out;
210
211 err = ubifs_log_post_commit(c, old_ltail_lnum);
212 if (err)
213 goto out;
214 err = ubifs_gc_end_commit(c);
215 if (err)
216 goto out;
217 err = ubifs_lpt_post_commit(c);
218 if (err)
219 goto out;
220
221out_cancel:
222 spin_lock(&c->cs_lock);
223 c->cmt_state = COMMIT_RESTING;
224 wake_up(&c->cmt_wq);
225 dbg_cmt("commit end");
226 spin_unlock(&c->cs_lock);
227 return 0;
228
229out_up:
230 up_write(&c->commit_sem);
231out:
232 ubifs_err("commit failed, error %d", err);
233 spin_lock(&c->cs_lock);
234 c->cmt_state = COMMIT_BROKEN;
235 wake_up(&c->cmt_wq);
236 spin_unlock(&c->cs_lock);
237 ubifs_ro_mode(c, err);
238 return err;
239}
240
241/**
242 * run_bg_commit - run background commit if it is needed.
243 * @c: UBIFS file-system description object
244 *
245 * This function runs background commit if it is needed. Returns zero in case
246 * of success and a negative error code in case of failure.
247 */
248static int run_bg_commit(struct ubifs_info *c)
249{
250 spin_lock(&c->cs_lock);
251 /*
252 * Run background commit only if background commit was requested or if
253 * commit is required.
254 */
255 if (c->cmt_state != COMMIT_BACKGROUND &&
256 c->cmt_state != COMMIT_REQUIRED)
257 goto out;
258 spin_unlock(&c->cs_lock);
259
260 down_write(&c->commit_sem);
261 spin_lock(&c->cs_lock);
262 if (c->cmt_state == COMMIT_REQUIRED)
263 c->cmt_state = COMMIT_RUNNING_REQUIRED;
264 else if (c->cmt_state == COMMIT_BACKGROUND)
265 c->cmt_state = COMMIT_RUNNING_BACKGROUND;
266 else
267 goto out_cmt_unlock;
268 spin_unlock(&c->cs_lock);
269
270 return do_commit(c);
271
272out_cmt_unlock:
273 up_write(&c->commit_sem);
274out:
275 spin_unlock(&c->cs_lock);
276 return 0;
277}
278
279/**
280 * ubifs_bg_thread - UBIFS background thread function.
281 * @info: points to the file-system description object
282 *
283 * This function implements various file-system background activities:
284 * o when a write-buffer timer expires it synchronizes the appropriate
285 * write-buffer;
286 * o when the journal is about to be full, it starts in-advance commit.
287 *
288 * Note, other stuff like background garbage collection may be added here in
289 * future.
290 */
291int ubifs_bg_thread(void *info)
292{
293 int err;
294 struct ubifs_info *c = info;
295
296 ubifs_msg("background thread \"%s\" started, PID %d",
297 c->bgt_name, current->pid);
298 set_freezable();
299
300 while (1) {
301 if (kthread_should_stop())
302 break;
303
304 if (try_to_freeze())
305 continue;
306
307 set_current_state(TASK_INTERRUPTIBLE);
308 /* Check if there is something to do */
309 if (!c->need_bgt) {
310 /*
311 * Nothing prevents us from going sleep now and
312 * be never woken up and block the task which
313 * could wait in 'kthread_stop()' forever.
314 */
315 if (kthread_should_stop())
316 break;
317 schedule();
318 continue;
319 } else
320 __set_current_state(TASK_RUNNING);
321
322 c->need_bgt = 0;
323 err = ubifs_bg_wbufs_sync(c);
324 if (err)
325 ubifs_ro_mode(c, err);
326
327 run_bg_commit(c);
328 cond_resched();
329 }
330
331 ubifs_msg("background thread \"%s\" stops", c->bgt_name);
332 return 0;
333}
334
335/**
336 * ubifs_commit_required - set commit state to "required".
337 * @c: UBIFS file-system description object
338 *
339 * This function is called if a commit is required but cannot be done from the
340 * calling function, so it is just flagged instead.
341 */
342void ubifs_commit_required(struct ubifs_info *c)
343{
344 spin_lock(&c->cs_lock);
345 switch (c->cmt_state) {
346 case COMMIT_RESTING:
347 case COMMIT_BACKGROUND:
348 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
349 dbg_cstate(COMMIT_REQUIRED));
350 c->cmt_state = COMMIT_REQUIRED;
351 break;
352 case COMMIT_RUNNING_BACKGROUND:
353 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
354 dbg_cstate(COMMIT_RUNNING_REQUIRED));
355 c->cmt_state = COMMIT_RUNNING_REQUIRED;
356 break;
357 case COMMIT_REQUIRED:
358 case COMMIT_RUNNING_REQUIRED:
359 case COMMIT_BROKEN:
360 break;
361 }
362 spin_unlock(&c->cs_lock);
363}
364
365/**
366 * ubifs_request_bg_commit - notify the background thread to do a commit.
367 * @c: UBIFS file-system description object
368 *
369 * This function is called if the journal is full enough to make a commit
370 * worthwhile, so background thread is kicked to start it.
371 */
372void ubifs_request_bg_commit(struct ubifs_info *c)
373{
374 spin_lock(&c->cs_lock);
375 if (c->cmt_state == COMMIT_RESTING) {
376 dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
377 dbg_cstate(COMMIT_BACKGROUND));
378 c->cmt_state = COMMIT_BACKGROUND;
379 spin_unlock(&c->cs_lock);
380 ubifs_wake_up_bgt(c);
381 } else
382 spin_unlock(&c->cs_lock);
383}
384
385/**
386 * wait_for_commit - wait for commit.
387 * @c: UBIFS file-system description object
388 *
389 * This function sleeps until the commit operation is no longer running.
390 */
391static int wait_for_commit(struct ubifs_info *c)
392{
393 dbg_cmt("pid %d goes sleep", current->pid);
394
395 /*
396 * The following sleeps if the condition is false, and will be woken
397 * when the commit ends. It is possible, although very unlikely, that we
398 * will wake up and see the subsequent commit running, rather than the
399 * one we were waiting for, and go back to sleep. However, we will be
400 * woken again, so there is no danger of sleeping forever.
401 */
402 wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
403 c->cmt_state != COMMIT_RUNNING_REQUIRED);
404 dbg_cmt("commit finished, pid %d woke up", current->pid);
405 return 0;
406}
407
408/**
409 * ubifs_run_commit - run or wait for commit.
410 * @c: UBIFS file-system description object
411 *
412 * This function runs commit and returns zero in case of success and a negative
413 * error code in case of failure.
414 */
415int ubifs_run_commit(struct ubifs_info *c)
416{
417 int err = 0;
418
419 spin_lock(&c->cs_lock);
420 if (c->cmt_state == COMMIT_BROKEN) {
421 err = -EROFS;
422 goto out;
423 }
424
425 if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
426 /*
427 * We set the commit state to 'running required' to indicate
428 * that we want it to complete as quickly as possible.
429 */
430 c->cmt_state = COMMIT_RUNNING_REQUIRED;
431
432 if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
433 spin_unlock(&c->cs_lock);
434 return wait_for_commit(c);
435 }
436 spin_unlock(&c->cs_lock);
437
438 /* Ok, the commit is indeed needed */
439
440 down_write(&c->commit_sem);
441 spin_lock(&c->cs_lock);
442 /*
443 * Since we unlocked 'c->cs_lock', the state may have changed, so
444 * re-check it.
445 */
446 if (c->cmt_state == COMMIT_BROKEN) {
447 err = -EROFS;
448 goto out_cmt_unlock;
449 }
450
451 if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
452 c->cmt_state = COMMIT_RUNNING_REQUIRED;
453
454 if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
455 up_write(&c->commit_sem);
456 spin_unlock(&c->cs_lock);
457 return wait_for_commit(c);
458 }
459 c->cmt_state = COMMIT_RUNNING_REQUIRED;
460 spin_unlock(&c->cs_lock);
461
462 err = do_commit(c);
463 return err;
464
465out_cmt_unlock:
466 up_write(&c->commit_sem);
467out:
468 spin_unlock(&c->cs_lock);
469 return err;
470}
471
472/**
473 * ubifs_gc_should_commit - determine if it is time for GC to run commit.
474 * @c: UBIFS file-system description object
475 *
476 * This function is called by garbage collection to determine if commit should
477 * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
478 * is full enough to start commit, this function returns true. It is not
479 * absolutely necessary to commit yet, but it feels like this should be better
480 * then to keep doing GC. This function returns %1 if GC has to initiate commit
481 * and %0 if not.
482 */
483int ubifs_gc_should_commit(struct ubifs_info *c)
484{
485 int ret = 0;
486
487 spin_lock(&c->cs_lock);
488 if (c->cmt_state == COMMIT_BACKGROUND) {
489 dbg_cmt("commit required now");
490 c->cmt_state = COMMIT_REQUIRED;
491 } else
492 dbg_cmt("commit not requested");
493 if (c->cmt_state == COMMIT_REQUIRED)
494 ret = 1;
495 spin_unlock(&c->cs_lock);
496 return ret;
497}
498
499/*
500 * Everything below is related to debugging.
501 */
502
503/**
504 * struct idx_node - hold index nodes during index tree traversal.
505 * @list: list
506 * @iip: index in parent (slot number of this indexing node in the parent
507 * indexing node)
508 * @upper_key: all keys in this indexing node have to be less or equivalent to
509 * this key
510 * @idx: index node (8-byte aligned because all node structures must be 8-byte
511 * aligned)
512 */
513struct idx_node {
514 struct list_head list;
515 int iip;
516 union ubifs_key upper_key;
517 struct ubifs_idx_node idx __aligned(8);
518};
519
520/**
521 * dbg_old_index_check_init - get information for the next old index check.
522 * @c: UBIFS file-system description object
523 * @zroot: root of the index
524 *
525 * This function records information about the index that will be needed for the
526 * next old index check i.e. 'dbg_check_old_index()'.
527 *
528 * This function returns %0 on success and a negative error code on failure.
529 */
530int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
531{
532 struct ubifs_idx_node *idx;
533 int lnum, offs, len, err = 0;
534 struct ubifs_debug_info *d = c->dbg;
535
536 d->old_zroot = *zroot;
537 lnum = d->old_zroot.lnum;
538 offs = d->old_zroot.offs;
539 len = d->old_zroot.len;
540
541 idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
542 if (!idx)
543 return -ENOMEM;
544
545 err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
546 if (err)
547 goto out;
548
549 d->old_zroot_level = le16_to_cpu(idx->level);
550 d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
551out:
552 kfree(idx);
553 return err;
554}
555
556/**
557 * dbg_check_old_index - check the old copy of the index.
558 * @c: UBIFS file-system description object
559 * @zroot: root of the new index
560 *
561 * In order to be able to recover from an unclean unmount, a complete copy of
562 * the index must exist on flash. This is the "old" index. The commit process
563 * must write the "new" index to flash without overwriting or destroying any
564 * part of the old index. This function is run at commit end in order to check
565 * that the old index does indeed exist completely intact.
566 *
567 * This function returns %0 on success and a negative error code on failure.
568 */
569int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
570{
571 int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
572 int first = 1, iip;
573 struct ubifs_debug_info *d = c->dbg;
574 union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key;
575 unsigned long long uninitialized_var(last_sqnum);
576 struct ubifs_idx_node *idx;
577 struct list_head list;
578 struct idx_node *i;
579 size_t sz;
580
581 if (!dbg_is_chk_index(c))
582 return 0;
583
584 INIT_LIST_HEAD(&list);
585
586 sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
587 UBIFS_IDX_NODE_SZ;
588
589 /* Start at the old zroot */
590 lnum = d->old_zroot.lnum;
591 offs = d->old_zroot.offs;
592 len = d->old_zroot.len;
593 iip = 0;
594
595 /*
596 * Traverse the index tree preorder depth-first i.e. do a node and then
597 * its subtrees from left to right.
598 */
599 while (1) {
600 struct ubifs_branch *br;
601
602 /* Get the next index node */
603 i = kmalloc(sz, GFP_NOFS);
604 if (!i) {
605 err = -ENOMEM;
606 goto out_free;
607 }
608 i->iip = iip;
609 /* Keep the index nodes on our path in a linked list */
610 list_add_tail(&i->list, &list);
611 /* Read the index node */
612 idx = &i->idx;
613 err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
614 if (err)
615 goto out_free;
616 /* Validate index node */
617 child_cnt = le16_to_cpu(idx->child_cnt);
618 if (child_cnt < 1 || child_cnt > c->fanout) {
619 err = 1;
620 goto out_dump;
621 }
622 if (first) {
623 first = 0;
624 /* Check root level and sqnum */
625 if (le16_to_cpu(idx->level) != d->old_zroot_level) {
626 err = 2;
627 goto out_dump;
628 }
629 if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) {
630 err = 3;
631 goto out_dump;
632 }
633 /* Set last values as though root had a parent */
634 last_level = le16_to_cpu(idx->level) + 1;
635 last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
636 key_read(c, ubifs_idx_key(c, idx), &lower_key);
637 highest_ino_key(c, &upper_key, INUM_WATERMARK);
638 }
639 key_copy(c, &upper_key, &i->upper_key);
640 if (le16_to_cpu(idx->level) != last_level - 1) {
641 err = 3;
642 goto out_dump;
643 }
644 /*
645 * The index is always written bottom up hence a child's sqnum
646 * is always less than the parents.
647 */
648 if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
649 err = 4;
650 goto out_dump;
651 }
652 /* Check key range */
653 key_read(c, ubifs_idx_key(c, idx), &l_key);
654 br = ubifs_idx_branch(c, idx, child_cnt - 1);
655 key_read(c, &br->key, &u_key);
656 if (keys_cmp(c, &lower_key, &l_key) > 0) {
657 err = 5;
658 goto out_dump;
659 }
660 if (keys_cmp(c, &upper_key, &u_key) < 0) {
661 err = 6;
662 goto out_dump;
663 }
664 if (keys_cmp(c, &upper_key, &u_key) == 0)
665 if (!is_hash_key(c, &u_key)) {
666 err = 7;
667 goto out_dump;
668 }
669 /* Go to next index node */
670 if (le16_to_cpu(idx->level) == 0) {
671 /* At the bottom, so go up until can go right */
672 while (1) {
673 /* Drop the bottom of the list */
674 list_del(&i->list);
675 kfree(i);
676 /* No more list means we are done */
677 if (list_empty(&list))
678 goto out;
679 /* Look at the new bottom */
680 i = list_entry(list.prev, struct idx_node,
681 list);
682 idx = &i->idx;
683 /* Can we go right */
684 if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
685 iip = iip + 1;
686 break;
687 } else
688 /* Nope, so go up again */
689 iip = i->iip;
690 }
691 } else
692 /* Go down left */
693 iip = 0;
694 /*
695 * We have the parent in 'idx' and now we set up for reading the
696 * child pointed to by slot 'iip'.
697 */
698 last_level = le16_to_cpu(idx->level);
699 last_sqnum = le64_to_cpu(idx->ch.sqnum);
700 br = ubifs_idx_branch(c, idx, iip);
701 lnum = le32_to_cpu(br->lnum);
702 offs = le32_to_cpu(br->offs);
703 len = le32_to_cpu(br->len);
704 key_read(c, &br->key, &lower_key);
705 if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
706 br = ubifs_idx_branch(c, idx, iip + 1);
707 key_read(c, &br->key, &upper_key);
708 } else
709 key_copy(c, &i->upper_key, &upper_key);
710 }
711out:
712 err = dbg_old_index_check_init(c, zroot);
713 if (err)
714 goto out_free;
715
716 return 0;
717
718out_dump:
719 ubifs_err("dumping index node (iip=%d)", i->iip);
720 ubifs_dump_node(c, idx);
721 list_del(&i->list);
722 kfree(i);
723 if (!list_empty(&list)) {
724 i = list_entry(list.prev, struct idx_node, list);
725 ubifs_err("dumping parent index node");
726 ubifs_dump_node(c, &i->idx);
727 }
728out_free:
729 while (!list_empty(&list)) {
730 i = list_entry(list.next, struct idx_node, list);
731 list_del(&i->list);
732 kfree(i);
733 }
734 ubifs_err("failed, error %d", err);
735 if (err > 0)
736 err = -EINVAL;
737 return err;
738}