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1 /* 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 redi
7 * under the terms of the GNU General Public L
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope tha
11 * ANY WARRANTY; without even the implied warr
12 * FITNESS FOR A PARTICULAR PURPOSE. See the
13 * more details.
14 *
15 * You should have received a copy of the GNU
16 * this program; if not, write to the Free Sof
17 * Franklin St, Fifth Floor, Boston, MA 02110-
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий
21 */
22
23 /*
24 * This file implements functions that manage
25 * Each affected module has its own functions
26 * commit and those functions are called here.
27 *
28 * The commit is the process whereby all updat
29 * are written out together and the journal be
30 * file system consistent - at all times the s
31 * the index and LEB properties and then repla
32 *
33 * The commit is split into two parts named "c
34 * During commit start, the commit process has
35 * by holding the commit semaphore down for wr
36 * possible are performed during commit start,
37 * written are merely identified. During commi
38 * longer held and the journal is again in ope
39 * to use the file system while the bulk of th
40 * purpose of this two-step approach is to pre
41 * latency blips. Note that in any case, the c
42 * (as permitted by the TNC mutex), or access
43 * cache.
44 */
45
46 #include <linux/freezer.h>
47 #include <linux/kthread.h>
48 #include "ubifs.h"
49
50 /**
51 * do_commit - commit the journal.
52 * @c: UBIFS file-system description object
53 *
54 * This function implements UBIFS commit. It h
55 * locked. Returns zero in case of success and
56 * failure.
57 */
58 static int do_commit(struct ubifs_info *c)
59 {
60 int err, new_ltail_lnum, old_ltail_lnu
61 struct ubifs_zbranch zroot;
62 struct ubifs_lp_stats lst;
63
64 dbg_cmt("start");
65 if (c->ro_media) {
66 err = -EROFS;
67 goto out_up;
68 }
69
70 /* Sync all write buffers (necessary f
71 for (i = 0; i < c->jhead_cnt; i++) {
72 err = ubifs_wbuf_sync(&c->jhea
73 if (err)
74 goto out_up;
75 }
76
77 c->cmt_no += 1;
78 err = ubifs_gc_start_commit(c);
79 if (err)
80 goto out_up;
81 err = dbg_check_lprops(c);
82 if (err)
83 goto out_up;
84 err = ubifs_log_start_commit(c, &new_l
85 if (err)
86 goto out_up;
87 err = ubifs_tnc_start_commit(c, &zroot
88 if (err)
89 goto out_up;
90 err = ubifs_lpt_start_commit(c);
91 if (err)
92 goto out_up;
93 err = ubifs_orphan_start_commit(c);
94 if (err)
95 goto out_up;
96
97 ubifs_get_lp_stats(c, &lst);
98
99 up_write(&c->commit_sem);
100
101 err = ubifs_tnc_end_commit(c);
102 if (err)
103 goto out;
104 err = ubifs_lpt_end_commit(c);
105 if (err)
106 goto out;
107 err = ubifs_orphan_end_commit(c);
108 if (err)
109 goto out;
110 old_ltail_lnum = c->ltail_lnum;
111 err = ubifs_log_end_commit(c, new_ltai
112 if (err)
113 goto out;
114 err = dbg_check_old_index(c, &zroot);
115 if (err)
116 goto out;
117
118 mutex_lock(&c->mst_mutex);
119 c->mst_node->cmt_no = cpu_to_le64
120 c->mst_node->log_lnum = cpu_to_le32
121 c->mst_node->root_lnum = cpu_to_le32
122 c->mst_node->root_offs = cpu_to_le32
123 c->mst_node->root_len = cpu_to_le32
124 c->mst_node->ihead_lnum = cpu_to_le32
125 c->mst_node->ihead_offs = cpu_to_le32
126 c->mst_node->index_size = cpu_to_le64
127 c->mst_node->lpt_lnum = cpu_to_le32
128 c->mst_node->lpt_offs = cpu_to_le32
129 c->mst_node->nhead_lnum = cpu_to_le32
130 c->mst_node->nhead_offs = cpu_to_le32
131 c->mst_node->ltab_lnum = cpu_to_le32
132 c->mst_node->ltab_offs = cpu_to_le32
133 c->mst_node->lsave_lnum = cpu_to_le32
134 c->mst_node->lsave_offs = cpu_to_le32
135 c->mst_node->lscan_lnum = cpu_to_le32
136 c->mst_node->empty_lebs = cpu_to_le32
137 c->mst_node->idx_lebs = cpu_to_le32
138 c->mst_node->total_free = cpu_to_le64
139 c->mst_node->total_dirty = cpu_to_le64
140 c->mst_node->total_used = cpu_to_le64
141 c->mst_node->total_dead = cpu_to_le64
142 c->mst_node->total_dark = cpu_to_le64
143 if (c->no_orphs)
144 c->mst_node->flags |= cpu_to_l
145 else
146 c->mst_node->flags &= ~cpu_to_
147 err = ubifs_write_master(c);
148 mutex_unlock(&c->mst_mutex);
149 if (err)
150 goto out;
151
152 err = ubifs_log_post_commit(c, old_lta
153 if (err)
154 goto out;
155 err = ubifs_gc_end_commit(c);
156 if (err)
157 goto out;
158 err = ubifs_lpt_post_commit(c);
159 if (err)
160 goto out;
161
162 spin_lock(&c->cs_lock);
163 c->cmt_state = COMMIT_RESTING;
164 wake_up(&c->cmt_wq);
165 dbg_cmt("commit end");
166 spin_unlock(&c->cs_lock);
167
168 return 0;
169
170 out_up:
171 up_write(&c->commit_sem);
172 out:
173 ubifs_err("commit failed, error %d", e
174 spin_lock(&c->cs_lock);
175 c->cmt_state = COMMIT_BROKEN;
176 wake_up(&c->cmt_wq);
177 spin_unlock(&c->cs_lock);
178 ubifs_ro_mode(c, err);
179 return err;
180 }
181
182 /**
183 * run_bg_commit - run background commit if it
184 * @c: UBIFS file-system description object
185 *
186 * This function runs background commit if it
187 * of success and a negative error code in cas
188 */
189 static int run_bg_commit(struct ubifs_info *c)
190 {
191 spin_lock(&c->cs_lock);
192 /*
193 * Run background commit only if backg
194 * commit is required.
195 */
196 if (c->cmt_state != COMMIT_BACKGROUND
197 c->cmt_state != COMMIT_REQUIRED)
198 goto out;
199 spin_unlock(&c->cs_lock);
200
201 down_write(&c->commit_sem);
202 spin_lock(&c->cs_lock);
203 if (c->cmt_state == COMMIT_REQUIRED)
204 c->cmt_state = COMMIT_RUNNING_
205 else if (c->cmt_state == COMMIT_BACKGR
206 c->cmt_state = COMMIT_RUNNING_
207 else
208 goto out_cmt_unlock;
209 spin_unlock(&c->cs_lock);
210
211 return do_commit(c);
212
213 out_cmt_unlock:
214 up_write(&c->commit_sem);
215 out:
216 spin_unlock(&c->cs_lock);
217 return 0;
218 }
219
220 /**
221 * ubifs_bg_thread - UBIFS background thread f
222 * @info: points to the file-system descriptio
223 *
224 * This function implements various file-syste
225 * o when a write-buffer timer expires it sync
226 * write-buffer;
227 * o when the journal is about to be full, it
228 *
229 * Note, other stuff like background garbage c
230 * future.
231 */
232 int ubifs_bg_thread(void *info)
233 {
234 int err;
235 struct ubifs_info *c = info;
236
237 dbg_msg("background thread \"%s\" star
238 c->bgt_name, current->pid);
239 set_freezable();
240
241 while (1) {
242 if (kthread_should_stop())
243 break;
244
245 if (try_to_freeze())
246 continue;
247
248 set_current_state(TASK_INTERRU
249 /* Check if there is something
250 if (!c->need_bgt) {
251 /*
252 * Nothing prevents us
253 * be never woken up a
254 * could wait in 'kthr
255 */
256 if (kthread_should_sto
257 break;
258 schedule();
259 continue;
260 } else
261 __set_current_state(TA
262
263 c->need_bgt = 0;
264 err = ubifs_bg_wbufs_sync(c);
265 if (err)
266 ubifs_ro_mode(c, err);
267
268 run_bg_commit(c);
269 cond_resched();
270 }
271
272 dbg_msg("background thread \"%s\" stop
273 return 0;
274 }
275
276 /**
277 * ubifs_commit_required - set commit state to
278 * @c: UBIFS file-system description object
279 *
280 * This function is called if a commit is requ
281 * calling function, so it is just flagged ins
282 */
283 void ubifs_commit_required(struct ubifs_info *
284 {
285 spin_lock(&c->cs_lock);
286 switch (c->cmt_state) {
287 case COMMIT_RESTING:
288 case COMMIT_BACKGROUND:
289 dbg_cmt("old: %s, new: %s", db
290 dbg_cstate(COMMIT_REQU
291 c->cmt_state = COMMIT_REQUIRED
292 break;
293 case COMMIT_RUNNING_BACKGROUND:
294 dbg_cmt("old: %s, new: %s", db
295 dbg_cstate(COMMIT_RUNN
296 c->cmt_state = COMMIT_RUNNING_
297 break;
298 case COMMIT_REQUIRED:
299 case COMMIT_RUNNING_REQUIRED:
300 case COMMIT_BROKEN:
301 break;
302 }
303 spin_unlock(&c->cs_lock);
304 }
305
306 /**
307 * ubifs_request_bg_commit - notify the backgr
308 * @c: UBIFS file-system description object
309 *
310 * This function is called if the journal is f
311 * worthwhile, so background thread is kicked
312 */
313 void ubifs_request_bg_commit(struct ubifs_info
314 {
315 spin_lock(&c->cs_lock);
316 if (c->cmt_state == COMMIT_RESTING) {
317 dbg_cmt("old: %s, new: %s", db
318 dbg_cstate(COMMIT_BACK
319 c->cmt_state = COMMIT_BACKGROU
320 spin_unlock(&c->cs_lock);
321 ubifs_wake_up_bgt(c);
322 } else
323 spin_unlock(&c->cs_lock);
324 }
325
326 /**
327 * wait_for_commit - wait for commit.
328 * @c: UBIFS file-system description object
329 *
330 * This function sleeps until the commit opera
331 */
332 static int wait_for_commit(struct ubifs_info *
333 {
334 dbg_cmt("pid %d goes sleep", current->
335
336 /*
337 * The following sleeps if the conditi
338 * when the commit ends. It is possibl
339 * will wake up and see the subsequent
340 * one we were waiting for, and go bac
341 * woken again, so there is no danger
342 */
343 wait_event(c->cmt_wq, c->cmt_state !=
344 c->cmt_state !=
345 dbg_cmt("commit finished, pid %d woke
346 return 0;
347 }
348
349 /**
350 * ubifs_run_commit - run or wait for commit.
351 * @c: UBIFS file-system description object
352 *
353 * This function runs commit and returns zero
354 * error code in case of failure.
355 */
356 int ubifs_run_commit(struct ubifs_info *c)
357 {
358 int err = 0;
359
360 spin_lock(&c->cs_lock);
361 if (c->cmt_state == COMMIT_BROKEN) {
362 err = -EINVAL;
363 goto out;
364 }
365
366 if (c->cmt_state == COMMIT_RUNNING_BAC
367 /*
368 * We set the commit state to
369 * that we want it to complete
370 */
371 c->cmt_state = COMMIT_RUNNING_
372
373 if (c->cmt_state == COMMIT_RUNNING_REQ
374 spin_unlock(&c->cs_lock);
375 return wait_for_commit(c);
376 }
377 spin_unlock(&c->cs_lock);
378
379 /* Ok, the commit is indeed needed */
380
381 down_write(&c->commit_sem);
382 spin_lock(&c->cs_lock);
383 /*
384 * Since we unlocked 'c->cs_lock', the
385 * re-check it.
386 */
387 if (c->cmt_state == COMMIT_BROKEN) {
388 err = -EINVAL;
389 goto out_cmt_unlock;
390 }
391
392 if (c->cmt_state == COMMIT_RUNNING_BAC
393 c->cmt_state = COMMIT_RUNNING_
394
395 if (c->cmt_state == COMMIT_RUNNING_REQ
396 up_write(&c->commit_sem);
397 spin_unlock(&c->cs_lock);
398 return wait_for_commit(c);
399 }
400 c->cmt_state = COMMIT_RUNNING_REQUIRED
401 spin_unlock(&c->cs_lock);
402
403 err = do_commit(c);
404 return err;
405
406 out_cmt_unlock:
407 up_write(&c->commit_sem);
408 out:
409 spin_unlock(&c->cs_lock);
410 return err;
411 }
412
413 /**
414 * ubifs_gc_should_commit - determine if it is
415 * @c: UBIFS file-system description object
416 *
417 * This function is called by garbage collecti
418 * be run. If commit state is @COMMIT_BACKGROU
419 * is full enough to start commit, this functi
420 * absolutely necessary to commit yet, but it
421 * then to keep doing GC. This function return
422 * and %0 if not.
423 */
424 int ubifs_gc_should_commit(struct ubifs_info *
425 {
426 int ret = 0;
427
428 spin_lock(&c->cs_lock);
429 if (c->cmt_state == COMMIT_BACKGROUND)
430 dbg_cmt("commit required now")
431 c->cmt_state = COMMIT_REQUIRED
432 } else
433 dbg_cmt("commit not requested"
434 if (c->cmt_state == COMMIT_REQUIRED)
435 ret = 1;
436 spin_unlock(&c->cs_lock);
437 return ret;
438 }
439
440 #ifdef CONFIG_UBIFS_FS_DEBUG
441
442 /**
443 * struct idx_node - hold index nodes during i
444 * @list: list
445 * @iip: index in parent (slot number of this
446 * indexing node)
447 * @upper_key: all keys in this indexing node
448 * this key
449 * @idx: index node (8-byte aligned because al
450 * aligned)
451 */
452 struct idx_node {
453 struct list_head list;
454 int iip;
455 union ubifs_key upper_key;
456 struct ubifs_idx_node idx __attribute_
457 };
458
459 /**
460 * dbg_old_index_check_init - get information
461 * @c: UBIFS file-system description object
462 * @zroot: root of the index
463 *
464 * This function records information about the
465 * next old index check i.e. 'dbg_check_old_in
466 *
467 * This function returns %0 on success and a n
468 */
469 int dbg_old_index_check_init(struct ubifs_info
470 {
471 struct ubifs_idx_node *idx;
472 int lnum, offs, len, err = 0;
473 struct ubifs_debug_info *d = c->dbg;
474
475 d->old_zroot = *zroot;
476 lnum = d->old_zroot.lnum;
477 offs = d->old_zroot.offs;
478 len = d->old_zroot.len;
479
480 idx = kmalloc(c->max_idx_node_sz, GFP_
481 if (!idx)
482 return -ENOMEM;
483
484 err = ubifs_read_node(c, idx, UBIFS_ID
485 if (err)
486 goto out;
487
488 d->old_zroot_level = le16_to_cpu(idx->
489 d->old_zroot_sqnum = le64_to_cpu(idx->
490 out:
491 kfree(idx);
492 return err;
493 }
494
495 /**
496 * dbg_check_old_index - check the old copy of
497 * @c: UBIFS file-system description object
498 * @zroot: root of the new index
499 *
500 * In order to be able to recover from an uncl
501 * the index must exist on flash. This is the
502 * must write the "new" index to flash without
503 * part of the old index. This function is run
504 * that the old index does indeed exist comple
505 *
506 * This function returns %0 on success and a n
507 */
508 int dbg_check_old_index(struct ubifs_info *c,
509 {
510 int lnum, offs, len, err = 0, uninitia
511 int first = 1, iip;
512 struct ubifs_debug_info *d = c->dbg;
513 union ubifs_key lower_key, upper_key,
514 unsigned long long uninitialized_var(l
515 struct ubifs_idx_node *idx;
516 struct list_head list;
517 struct idx_node *i;
518 size_t sz;
519
520 if (!(ubifs_chk_flags & UBIFS_CHK_OLD_
521 goto out;
522
523 INIT_LIST_HEAD(&list);
524
525 sz = sizeof(struct idx_node) + ubifs_i
526 UBIFS_IDX_NODE_SZ;
527
528 /* Start at the old zroot */
529 lnum = d->old_zroot.lnum;
530 offs = d->old_zroot.offs;
531 len = d->old_zroot.len;
532 iip = 0;
533
534 /*
535 * Traverse the index tree preorder de
536 * its subtrees from left to right.
537 */
538 while (1) {
539 struct ubifs_branch *br;
540
541 /* Get the next index node */
542 i = kmalloc(sz, GFP_NOFS);
543 if (!i) {
544 err = -ENOMEM;
545 goto out_free;
546 }
547 i->iip = iip;
548 /* Keep the index nodes on our
549 list_add_tail(&i->list, &list)
550 /* Read the index node */
551 idx = &i->idx;
552 err = ubifs_read_node(c, idx,
553 if (err)
554 goto out_free;
555 /* Validate index node */
556 child_cnt = le16_to_cpu(idx->c
557 if (child_cnt < 1 || child_cnt
558 err = 1;
559 goto out_dump;
560 }
561 if (first) {
562 first = 0;
563 /* Check root level an
564 if (le16_to_cpu(idx->l
565 err = 2;
566 goto out_dump;
567 }
568 if (le64_to_cpu(idx->c
569 err = 3;
570 goto out_dump;
571 }
572 /* Set last values as
573 last_level = le16_to_c
574 last_sqnum = le64_to_c
575 key_read(c, ubifs_idx_
576 highest_ino_key(c, &up
577 }
578 key_copy(c, &upper_key, &i->up
579 if (le16_to_cpu(idx->level) !=
580 err = 3;
581 goto out_dump;
582 }
583 /*
584 * The index is always written
585 * is always less than the par
586 */
587 if (le64_to_cpu(idx->ch.sqnum)
588 err = 4;
589 goto out_dump;
590 }
591 /* Check key range */
592 key_read(c, ubifs_idx_key(c, i
593 br = ubifs_idx_branch(c, idx,
594 key_read(c, &br->key, &u_key);
595 if (keys_cmp(c, &lower_key, &l
596 err = 5;
597 goto out_dump;
598 }
599 if (keys_cmp(c, &upper_key, &u
600 err = 6;
601 goto out_dump;
602 }
603 if (keys_cmp(c, &upper_key, &u
604 if (!is_hash_key(c, &u
605 err = 7;
606 goto out_dump;
607 }
608 /* Go to next index node */
609 if (le16_to_cpu(idx->level) ==
610 /* At the bottom, so g
611 while (1) {
612 /* Drop the bo
613 list_del(&i->l
614 kfree(i);
615 /* No more lis
616 if (list_empty
617 goto o
618 /* Look at the
619 i = list_entry
620
621 idx = &i->idx;
622 /* Can we go r
623 if (iip + 1 <
624 iip =
625 break;
626 } else
627 /* Nop
628 iip =
629 }
630 } else
631 /* Go down left */
632 iip = 0;
633 /*
634 * We have the parent in 'idx'
635 * child pointed to by slot 'i
636 */
637 last_level = le16_to_cpu(idx->
638 last_sqnum = le64_to_cpu(idx->
639 br = ubifs_idx_branch(c, idx,
640 lnum = le32_to_cpu(br->lnum);
641 offs = le32_to_cpu(br->offs);
642 len = le32_to_cpu(br->len);
643 key_read(c, &br->key, &lower_k
644 if (iip + 1 < le16_to_cpu(idx-
645 br = ubifs_idx_branch(
646 key_read(c, &br->key,
647 } else
648 key_copy(c, &i->upper_
649 }
650 out:
651 err = dbg_old_index_check_init(c, zroo
652 if (err)
653 goto out_free;
654
655 return 0;
656
657 out_dump:
658 dbg_err("dumping index node (iip=%d)",
659 dbg_dump_node(c, idx);
660 list_del(&i->list);
661 kfree(i);
662 if (!list_empty(&list)) {
663 i = list_entry(list.prev, stru
664 dbg_err("dumping parent index
665 dbg_dump_node(c, &i->idx);
666 }
667 out_free:
668 while (!list_empty(&list)) {
669 i = list_entry(list.next, stru
670 list_del(&i->list);
671 kfree(i);
672 }
673 ubifs_err("failed, error %d", err);
674 if (err > 0)
675 err = -EINVAL;
676 return err;
677 }
678
679 #endif /* CONFIG_UBIFS_FS_DEBUG */
680
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