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1e51764a AB |
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> | |
5a0e3ad6 | 48 | #include <linux/slab.h> |
1e51764a AB |
49 | #include "ubifs.h" |
50 | ||
944fdef5 AB |
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 | */ | |
68 | static 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 && test_bit(DIRTY_ZNODE, &c->zroot.znode->flags)) | |
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 | ||
1e51764a AB |
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 | */ | |
109 | static 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"); | |
2ef13294 | 116 | ubifs_assert(!c->ro_media && !c->ro_mount); |
2680d722 AB |
117 | |
118 | if (c->ro_error) { | |
1e51764a AB |
119 | err = -EROFS; |
120 | goto out_up; | |
121 | } | |
122 | ||
944fdef5 AB |
123 | if (nothing_to_commit(c)) { |
124 | up_write(&c->commit_sem); | |
125 | err = 0; | |
126 | goto out_cancel; | |
127 | } | |
128 | ||
1e51764a AB |
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 | ||
014eb04b | 136 | c->cmt_no += 1; |
1e51764a AB |
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); | |
014eb04b | 178 | c->mst_node->cmt_no = cpu_to_le64(c->cmt_no); |
1e51764a AB |
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->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 | ||
944fdef5 | 221 | out_cancel: |
1e51764a AB |
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); | |
1e51764a AB |
227 | return 0; |
228 | ||
229 | out_up: | |
230 | up_write(&c->commit_sem); | |
231 | out: | |
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 | */ | |
248 | static 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 | ||
272 | out_cmt_unlock: | |
273 | up_write(&c->commit_sem); | |
274 | out: | |
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 | */ | |
291 | int ubifs_bg_thread(void *info) | |
292 | { | |
293 | int err; | |
294 | struct ubifs_info *c = info; | |
295 | ||
069782a1 AB |
296 | dbg_msg("background thread \"%s\" started, PID %d", |
297 | c->bgt_name, current->pid); | |
1e51764a AB |
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 | */ | |
342 | void 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 | */ | |
372 | void 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 | */ | |
391 | static 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 | */ | |
415 | int 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 = -EINVAL; | |
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 = -EINVAL; | |
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 | ||
465 | out_cmt_unlock: | |
466 | up_write(&c->commit_sem); | |
467 | out: | |
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 | */ | |
483 | int 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 | */ | |
511 | struct 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 | */ | |
528 | int 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; | |
17c2f9f8 | 532 | struct ubifs_debug_info *d = c->dbg; |
1e51764a | 533 | |
17c2f9f8 AB |
534 | d->old_zroot = *zroot; |
535 | lnum = d->old_zroot.lnum; | |
536 | offs = d->old_zroot.offs; | |
537 | len = d->old_zroot.len; | |
1e51764a AB |
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 | ||
17c2f9f8 AB |
547 | d->old_zroot_level = le16_to_cpu(idx->level); |
548 | d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum); | |
1e51764a AB |
549 | out: |
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 | */ | |
567 | int 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; | |
17c2f9f8 | 571 | struct ubifs_debug_info *d = c->dbg; |
83ef2ecd | 572 | union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key; |
1e51764a AB |
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 (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX)) | |
8b229c76 | 580 | return 0; |
1e51764a AB |
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 */ | |
17c2f9f8 AB |
588 | lnum = d->old_zroot.lnum; |
589 | offs = d->old_zroot.offs; | |
590 | len = d->old_zroot.len; | |
1e51764a AB |
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 */ | |
17c2f9f8 | 623 | if (le16_to_cpu(idx->level) != d->old_zroot_level) { |
1e51764a AB |
624 | err = 2; |
625 | goto out_dump; | |
626 | } | |
17c2f9f8 | 627 | if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) { |
1e51764a AB |
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 | } | |
709 | out: | |
710 | err = dbg_old_index_check_init(c, zroot); | |
711 | if (err) | |
712 | goto out_free; | |
713 | ||
714 | return 0; | |
715 | ||
716 | out_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 | } | |
726 | out_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 */ |