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 implements functions that manage the running of the commit process. |
13 | * Each affected module has its own functions to accomplish their part in the |
14 | * commit and those functions are called here. |
15 | * |
16 | * The commit is the process whereby all updates to the index and LEB properties |
17 | * are written out together and the journal becomes empty. This keeps the |
18 | * file system consistent - at all times the state can be recreated by reading |
19 | * the index and LEB properties and then replaying the journal. |
20 | * |
21 | * The commit is split into two parts named "commit start" and "commit end". |
22 | * During commit start, the commit process has exclusive access to the journal |
23 | * by holding the commit semaphore down for writing. As few I/O operations as |
24 | * possible are performed during commit start, instead the nodes that are to be |
25 | * written are merely identified. During commit end, the commit semaphore is no |
26 | * longer held and the journal is again in operation, allowing users to continue |
27 | * to use the file system while the bulk of the commit I/O is performed. The |
28 | * purpose of this two-step approach is to prevent the commit from causing any |
29 | * latency blips. Note that in any case, the commit does not prevent lookups |
30 | * (as permitted by the TNC mutex), or access to VFS data structures e.g. page |
31 | * cache. |
32 | */ |
33 | |
34 | #include <linux/freezer.h> |
35 | #include <linux/kthread.h> |
36 | #include <linux/slab.h> |
37 | #include "ubifs.h" |
38 | |
39 | /* |
40 | * nothing_to_commit - check if there is nothing to commit. |
41 | * @c: UBIFS file-system description object |
42 | * |
43 | * This is a helper function which checks if there is anything to commit. It is |
44 | * used as an optimization to avoid starting the commit if it is not really |
45 | * necessary. Indeed, the commit operation always assumes flash I/O (e.g., |
46 | * writing the commit start node to the log), and it is better to avoid doing |
47 | * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is |
48 | * nothing to commit, it is more optimal to avoid any flash I/O. |
49 | * |
50 | * This function has to be called with @c->commit_sem locked for writing - |
51 | * this function does not take LPT/TNC locks because the @c->commit_sem |
52 | * guarantees that we have exclusive access to the TNC and LPT data structures. |
53 | * |
54 | * This function returns %1 if there is nothing to commit and %0 otherwise. |
55 | */ |
56 | static int nothing_to_commit(struct ubifs_info *c) |
57 | { |
58 | /* |
59 | * During mounting or remounting from R/O mode to R/W mode we may |
60 | * commit for various recovery-related reasons. |
61 | */ |
62 | if (c->mounting || c->remounting_rw) |
63 | return 0; |
64 | |
65 | /* |
66 | * If the root TNC node is dirty, we definitely have something to |
67 | * commit. |
68 | */ |
69 | if (c->zroot.znode && ubifs_zn_dirty(znode: c->zroot.znode)) |
70 | return 0; |
71 | |
72 | /* |
73 | * Increasing @c->dirty_pn_cnt/@c->dirty_nn_cnt and marking |
74 | * nnodes/pnodes as dirty in run_gc() could race with following |
75 | * checking, which leads inconsistent states between @c->nroot |
76 | * and @c->dirty_pn_cnt/@c->dirty_nn_cnt, holding @c->lp_mutex |
77 | * to avoid that. |
78 | */ |
79 | mutex_lock(&c->lp_mutex); |
80 | /* |
81 | * Even though the TNC is clean, the LPT tree may have dirty nodes. For |
82 | * example, this may happen if the budgeting subsystem invoked GC to |
83 | * make some free space, and the GC found an LEB with only dirty and |
84 | * free space. In this case GC would just change the lprops of this |
85 | * LEB (by turning all space into free space) and unmap it. |
86 | */ |
87 | if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags)) { |
88 | mutex_unlock(lock: &c->lp_mutex); |
89 | return 0; |
90 | } |
91 | |
92 | ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); |
93 | ubifs_assert(c, c->dirty_pn_cnt == 0); |
94 | ubifs_assert(c, c->dirty_nn_cnt == 0); |
95 | mutex_unlock(lock: &c->lp_mutex); |
96 | |
97 | return 1; |
98 | } |
99 | |
100 | /** |
101 | * do_commit - commit the journal. |
102 | * @c: UBIFS file-system description object |
103 | * |
104 | * This function implements UBIFS commit. It has to be called with commit lock |
105 | * locked. Returns zero in case of success and a negative error code in case of |
106 | * failure. |
107 | */ |
108 | static int do_commit(struct ubifs_info *c) |
109 | { |
110 | int err, new_ltail_lnum, old_ltail_lnum, i; |
111 | struct ubifs_zbranch zroot; |
112 | struct ubifs_lp_stats lst; |
113 | |
114 | dbg_cmt("start" ); |
115 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
116 | |
117 | if (c->ro_error) { |
118 | err = -EROFS; |
119 | goto out_up; |
120 | } |
121 | |
122 | if (nothing_to_commit(c)) { |
123 | up_write(sem: &c->commit_sem); |
124 | err = 0; |
125 | goto out_cancel; |
126 | } |
127 | |
128 | /* Sync all write buffers (necessary for recovery) */ |
129 | for (i = 0; i < c->jhead_cnt; i++) { |
130 | err = ubifs_wbuf_sync(wbuf: &c->jheads[i].wbuf); |
131 | if (err) |
132 | goto out_up; |
133 | } |
134 | |
135 | c->cmt_no += 1; |
136 | err = ubifs_gc_start_commit(c); |
137 | if (err) |
138 | goto out_up; |
139 | err = dbg_check_lprops(c); |
140 | if (err) |
141 | goto out_up; |
142 | err = ubifs_log_start_commit(c, ltail_lnum: &new_ltail_lnum); |
143 | if (err) |
144 | goto out_up; |
145 | err = ubifs_tnc_start_commit(c, zroot: &zroot); |
146 | if (err) |
147 | goto out_up; |
148 | err = ubifs_lpt_start_commit(c); |
149 | if (err) |
150 | goto out_up; |
151 | err = ubifs_orphan_start_commit(c); |
152 | if (err) |
153 | goto out_up; |
154 | |
155 | ubifs_get_lp_stats(c, lst: &lst); |
156 | |
157 | up_write(sem: &c->commit_sem); |
158 | |
159 | err = ubifs_tnc_end_commit(c); |
160 | if (err) |
161 | goto out; |
162 | err = ubifs_lpt_end_commit(c); |
163 | if (err) |
164 | goto out; |
165 | err = ubifs_orphan_end_commit(c); |
166 | if (err) |
167 | goto out; |
168 | err = dbg_check_old_index(c, zroot: &zroot); |
169 | if (err) |
170 | goto out; |
171 | |
172 | c->mst_node->cmt_no = cpu_to_le64(c->cmt_no); |
173 | c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum); |
174 | c->mst_node->root_lnum = cpu_to_le32(zroot.lnum); |
175 | c->mst_node->root_offs = cpu_to_le32(zroot.offs); |
176 | c->mst_node->root_len = cpu_to_le32(zroot.len); |
177 | c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum); |
178 | c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs); |
179 | c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz); |
180 | c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum); |
181 | c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs); |
182 | c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum); |
183 | c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs); |
184 | c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum); |
185 | c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs); |
186 | c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum); |
187 | c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs); |
188 | c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum); |
189 | c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs); |
190 | c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs); |
191 | c->mst_node->total_free = cpu_to_le64(lst.total_free); |
192 | c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty); |
193 | c->mst_node->total_used = cpu_to_le64(lst.total_used); |
194 | c->mst_node->total_dead = cpu_to_le64(lst.total_dead); |
195 | c->mst_node->total_dark = cpu_to_le64(lst.total_dark); |
196 | if (c->no_orphs) |
197 | c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); |
198 | else |
199 | c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS); |
200 | |
201 | old_ltail_lnum = c->ltail_lnum; |
202 | err = ubifs_log_end_commit(c, new_ltail_lnum); |
203 | if (err) |
204 | goto out; |
205 | |
206 | err = ubifs_log_post_commit(c, old_ltail_lnum); |
207 | if (err) |
208 | goto out; |
209 | err = ubifs_gc_end_commit(c); |
210 | if (err) |
211 | goto out; |
212 | err = ubifs_lpt_post_commit(c); |
213 | if (err) |
214 | goto out; |
215 | |
216 | out_cancel: |
217 | spin_lock(lock: &c->cs_lock); |
218 | c->cmt_state = COMMIT_RESTING; |
219 | wake_up(&c->cmt_wq); |
220 | dbg_cmt("commit end" ); |
221 | spin_unlock(lock: &c->cs_lock); |
222 | return 0; |
223 | |
224 | out_up: |
225 | up_write(sem: &c->commit_sem); |
226 | out: |
227 | ubifs_err(c, fmt: "commit failed, error %d" , err); |
228 | spin_lock(lock: &c->cs_lock); |
229 | c->cmt_state = COMMIT_BROKEN; |
230 | wake_up(&c->cmt_wq); |
231 | spin_unlock(lock: &c->cs_lock); |
232 | ubifs_ro_mode(c, err); |
233 | return err; |
234 | } |
235 | |
236 | /** |
237 | * run_bg_commit - run background commit if it is needed. |
238 | * @c: UBIFS file-system description object |
239 | * |
240 | * This function runs background commit if it is needed. Returns zero in case |
241 | * of success and a negative error code in case of failure. |
242 | */ |
243 | static int run_bg_commit(struct ubifs_info *c) |
244 | { |
245 | spin_lock(lock: &c->cs_lock); |
246 | /* |
247 | * Run background commit only if background commit was requested or if |
248 | * commit is required. |
249 | */ |
250 | if (c->cmt_state != COMMIT_BACKGROUND && |
251 | c->cmt_state != COMMIT_REQUIRED) |
252 | goto out; |
253 | spin_unlock(lock: &c->cs_lock); |
254 | |
255 | down_write(sem: &c->commit_sem); |
256 | spin_lock(lock: &c->cs_lock); |
257 | if (c->cmt_state == COMMIT_REQUIRED) |
258 | c->cmt_state = COMMIT_RUNNING_REQUIRED; |
259 | else if (c->cmt_state == COMMIT_BACKGROUND) |
260 | c->cmt_state = COMMIT_RUNNING_BACKGROUND; |
261 | else |
262 | goto out_cmt_unlock; |
263 | spin_unlock(lock: &c->cs_lock); |
264 | |
265 | return do_commit(c); |
266 | |
267 | out_cmt_unlock: |
268 | up_write(sem: &c->commit_sem); |
269 | out: |
270 | spin_unlock(lock: &c->cs_lock); |
271 | return 0; |
272 | } |
273 | |
274 | /** |
275 | * ubifs_bg_thread - UBIFS background thread function. |
276 | * @info: points to the file-system description object |
277 | * |
278 | * This function implements various file-system background activities: |
279 | * o when a write-buffer timer expires it synchronizes the appropriate |
280 | * write-buffer; |
281 | * o when the journal is about to be full, it starts in-advance commit. |
282 | * |
283 | * Note, other stuff like background garbage collection may be added here in |
284 | * future. |
285 | */ |
286 | int ubifs_bg_thread(void *info) |
287 | { |
288 | int err; |
289 | struct ubifs_info *c = info; |
290 | |
291 | ubifs_msg(c, fmt: "background thread \"%s\" started, PID %d" , |
292 | c->bgt_name, current->pid); |
293 | set_freezable(); |
294 | |
295 | while (1) { |
296 | if (kthread_should_stop()) |
297 | break; |
298 | |
299 | if (try_to_freeze()) |
300 | continue; |
301 | |
302 | set_current_state(TASK_INTERRUPTIBLE); |
303 | /* Check if there is something to do */ |
304 | if (!c->need_bgt) { |
305 | /* |
306 | * Nothing prevents us from going sleep now and |
307 | * be never woken up and block the task which |
308 | * could wait in 'kthread_stop()' forever. |
309 | */ |
310 | if (kthread_should_stop()) |
311 | break; |
312 | schedule(); |
313 | continue; |
314 | } else |
315 | __set_current_state(TASK_RUNNING); |
316 | |
317 | c->need_bgt = 0; |
318 | err = ubifs_bg_wbufs_sync(c); |
319 | if (err) |
320 | ubifs_ro_mode(c, err); |
321 | |
322 | run_bg_commit(c); |
323 | cond_resched(); |
324 | } |
325 | |
326 | ubifs_msg(c, fmt: "background thread \"%s\" stops" , c->bgt_name); |
327 | return 0; |
328 | } |
329 | |
330 | /** |
331 | * ubifs_commit_required - set commit state to "required". |
332 | * @c: UBIFS file-system description object |
333 | * |
334 | * This function is called if a commit is required but cannot be done from the |
335 | * calling function, so it is just flagged instead. |
336 | */ |
337 | void ubifs_commit_required(struct ubifs_info *c) |
338 | { |
339 | spin_lock(lock: &c->cs_lock); |
340 | switch (c->cmt_state) { |
341 | case COMMIT_RESTING: |
342 | case COMMIT_BACKGROUND: |
343 | dbg_cmt("old: %s, new: %s" , dbg_cstate(c->cmt_state), |
344 | dbg_cstate(COMMIT_REQUIRED)); |
345 | c->cmt_state = COMMIT_REQUIRED; |
346 | break; |
347 | case COMMIT_RUNNING_BACKGROUND: |
348 | dbg_cmt("old: %s, new: %s" , dbg_cstate(c->cmt_state), |
349 | dbg_cstate(COMMIT_RUNNING_REQUIRED)); |
350 | c->cmt_state = COMMIT_RUNNING_REQUIRED; |
351 | break; |
352 | case COMMIT_REQUIRED: |
353 | case COMMIT_RUNNING_REQUIRED: |
354 | case COMMIT_BROKEN: |
355 | break; |
356 | } |
357 | spin_unlock(lock: &c->cs_lock); |
358 | } |
359 | |
360 | /** |
361 | * ubifs_request_bg_commit - notify the background thread to do a commit. |
362 | * @c: UBIFS file-system description object |
363 | * |
364 | * This function is called if the journal is full enough to make a commit |
365 | * worthwhile, so background thread is kicked to start it. |
366 | */ |
367 | void ubifs_request_bg_commit(struct ubifs_info *c) |
368 | { |
369 | spin_lock(lock: &c->cs_lock); |
370 | if (c->cmt_state == COMMIT_RESTING) { |
371 | dbg_cmt("old: %s, new: %s" , dbg_cstate(c->cmt_state), |
372 | dbg_cstate(COMMIT_BACKGROUND)); |
373 | c->cmt_state = COMMIT_BACKGROUND; |
374 | spin_unlock(lock: &c->cs_lock); |
375 | ubifs_wake_up_bgt(c); |
376 | } else |
377 | spin_unlock(lock: &c->cs_lock); |
378 | } |
379 | |
380 | /** |
381 | * wait_for_commit - wait for commit. |
382 | * @c: UBIFS file-system description object |
383 | * |
384 | * This function sleeps until the commit operation is no longer running. |
385 | */ |
386 | static int wait_for_commit(struct ubifs_info *c) |
387 | { |
388 | dbg_cmt("pid %d goes sleep" , current->pid); |
389 | |
390 | /* |
391 | * The following sleeps if the condition is false, and will be woken |
392 | * when the commit ends. It is possible, although very unlikely, that we |
393 | * will wake up and see the subsequent commit running, rather than the |
394 | * one we were waiting for, and go back to sleep. However, we will be |
395 | * woken again, so there is no danger of sleeping forever. |
396 | */ |
397 | wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND && |
398 | c->cmt_state != COMMIT_RUNNING_REQUIRED); |
399 | dbg_cmt("commit finished, pid %d woke up" , current->pid); |
400 | return 0; |
401 | } |
402 | |
403 | /** |
404 | * ubifs_run_commit - run or wait for commit. |
405 | * @c: UBIFS file-system description object |
406 | * |
407 | * This function runs commit and returns zero in case of success and a negative |
408 | * error code in case of failure. |
409 | */ |
410 | int ubifs_run_commit(struct ubifs_info *c) |
411 | { |
412 | int err = 0; |
413 | |
414 | spin_lock(lock: &c->cs_lock); |
415 | if (c->cmt_state == COMMIT_BROKEN) { |
416 | err = -EROFS; |
417 | goto out; |
418 | } |
419 | |
420 | if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) |
421 | /* |
422 | * We set the commit state to 'running required' to indicate |
423 | * that we want it to complete as quickly as possible. |
424 | */ |
425 | c->cmt_state = COMMIT_RUNNING_REQUIRED; |
426 | |
427 | if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { |
428 | spin_unlock(lock: &c->cs_lock); |
429 | return wait_for_commit(c); |
430 | } |
431 | spin_unlock(lock: &c->cs_lock); |
432 | |
433 | /* Ok, the commit is indeed needed */ |
434 | |
435 | down_write(sem: &c->commit_sem); |
436 | spin_lock(lock: &c->cs_lock); |
437 | /* |
438 | * Since we unlocked 'c->cs_lock', the state may have changed, so |
439 | * re-check it. |
440 | */ |
441 | if (c->cmt_state == COMMIT_BROKEN) { |
442 | err = -EROFS; |
443 | goto out_cmt_unlock; |
444 | } |
445 | |
446 | if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) |
447 | c->cmt_state = COMMIT_RUNNING_REQUIRED; |
448 | |
449 | if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { |
450 | up_write(sem: &c->commit_sem); |
451 | spin_unlock(lock: &c->cs_lock); |
452 | return wait_for_commit(c); |
453 | } |
454 | c->cmt_state = COMMIT_RUNNING_REQUIRED; |
455 | spin_unlock(lock: &c->cs_lock); |
456 | |
457 | err = do_commit(c); |
458 | return err; |
459 | |
460 | out_cmt_unlock: |
461 | up_write(sem: &c->commit_sem); |
462 | out: |
463 | spin_unlock(lock: &c->cs_lock); |
464 | return err; |
465 | } |
466 | |
467 | /** |
468 | * ubifs_gc_should_commit - determine if it is time for GC to run commit. |
469 | * @c: UBIFS file-system description object |
470 | * |
471 | * This function is called by garbage collection to determine if commit should |
472 | * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal |
473 | * is full enough to start commit, this function returns true. It is not |
474 | * absolutely necessary to commit yet, but it feels like this should be better |
475 | * then to keep doing GC. This function returns %1 if GC has to initiate commit |
476 | * and %0 if not. |
477 | */ |
478 | int ubifs_gc_should_commit(struct ubifs_info *c) |
479 | { |
480 | int ret = 0; |
481 | |
482 | spin_lock(lock: &c->cs_lock); |
483 | if (c->cmt_state == COMMIT_BACKGROUND) { |
484 | dbg_cmt("commit required now" ); |
485 | c->cmt_state = COMMIT_REQUIRED; |
486 | } else |
487 | dbg_cmt("commit not requested" ); |
488 | if (c->cmt_state == COMMIT_REQUIRED) |
489 | ret = 1; |
490 | spin_unlock(lock: &c->cs_lock); |
491 | return ret; |
492 | } |
493 | |
494 | /* |
495 | * Everything below is related to debugging. |
496 | */ |
497 | |
498 | /** |
499 | * struct idx_node - hold index nodes during index tree traversal. |
500 | * @list: list |
501 | * @iip: index in parent (slot number of this indexing node in the parent |
502 | * indexing node) |
503 | * @upper_key: all keys in this indexing node have to be less or equivalent to |
504 | * this key |
505 | * @idx: index node (8-byte aligned because all node structures must be 8-byte |
506 | * aligned) |
507 | */ |
508 | struct idx_node { |
509 | struct list_head list; |
510 | int iip; |
511 | union ubifs_key upper_key; |
512 | struct ubifs_idx_node idx __aligned(8); |
513 | }; |
514 | |
515 | /** |
516 | * dbg_old_index_check_init - get information for the next old index check. |
517 | * @c: UBIFS file-system description object |
518 | * @zroot: root of the index |
519 | * |
520 | * This function records information about the index that will be needed for the |
521 | * next old index check i.e. 'dbg_check_old_index()'. |
522 | * |
523 | * This function returns %0 on success and a negative error code on failure. |
524 | */ |
525 | int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot) |
526 | { |
527 | struct ubifs_idx_node *idx; |
528 | int lnum, offs, len, err = 0; |
529 | struct ubifs_debug_info *d = c->dbg; |
530 | |
531 | d->old_zroot = *zroot; |
532 | lnum = d->old_zroot.lnum; |
533 | offs = d->old_zroot.offs; |
534 | len = d->old_zroot.len; |
535 | |
536 | idx = kmalloc(size: c->max_idx_node_sz, GFP_NOFS); |
537 | if (!idx) |
538 | return -ENOMEM; |
539 | |
540 | err = ubifs_read_node(c, buf: idx, type: UBIFS_IDX_NODE, len, lnum, offs); |
541 | if (err) |
542 | goto out; |
543 | |
544 | d->old_zroot_level = le16_to_cpu(idx->level); |
545 | d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum); |
546 | out: |
547 | kfree(objp: idx); |
548 | return err; |
549 | } |
550 | |
551 | /** |
552 | * dbg_check_old_index - check the old copy of the index. |
553 | * @c: UBIFS file-system description object |
554 | * @zroot: root of the new index |
555 | * |
556 | * In order to be able to recover from an unclean unmount, a complete copy of |
557 | * the index must exist on flash. This is the "old" index. The commit process |
558 | * must write the "new" index to flash without overwriting or destroying any |
559 | * part of the old index. This function is run at commit end in order to check |
560 | * that the old index does indeed exist completely intact. |
561 | * |
562 | * This function returns %0 on success and a negative error code on failure. |
563 | */ |
564 | int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot) |
565 | { |
566 | int lnum, offs, len, err = 0, last_level, child_cnt; |
567 | int first = 1, iip; |
568 | struct ubifs_debug_info *d = c->dbg; |
569 | union ubifs_key lower_key, upper_key, l_key, u_key; |
570 | unsigned long long last_sqnum; |
571 | struct ubifs_idx_node *idx; |
572 | struct list_head list; |
573 | struct idx_node *i; |
574 | size_t sz; |
575 | |
576 | if (!dbg_is_chk_index(c)) |
577 | return 0; |
578 | |
579 | INIT_LIST_HEAD(list: &list); |
580 | |
581 | sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, child_cnt: c->fanout) - |
582 | UBIFS_IDX_NODE_SZ; |
583 | |
584 | /* Start at the old zroot */ |
585 | lnum = d->old_zroot.lnum; |
586 | offs = d->old_zroot.offs; |
587 | len = d->old_zroot.len; |
588 | iip = 0; |
589 | |
590 | /* |
591 | * Traverse the index tree preorder depth-first i.e. do a node and then |
592 | * its subtrees from left to right. |
593 | */ |
594 | while (1) { |
595 | struct ubifs_branch *br; |
596 | |
597 | /* Get the next index node */ |
598 | i = kmalloc(size: sz, GFP_NOFS); |
599 | if (!i) { |
600 | err = -ENOMEM; |
601 | goto out_free; |
602 | } |
603 | i->iip = iip; |
604 | /* Keep the index nodes on our path in a linked list */ |
605 | list_add_tail(new: &i->list, head: &list); |
606 | /* Read the index node */ |
607 | idx = &i->idx; |
608 | err = ubifs_read_node(c, buf: idx, type: UBIFS_IDX_NODE, len, lnum, offs); |
609 | if (err) |
610 | goto out_free; |
611 | /* Validate index node */ |
612 | child_cnt = le16_to_cpu(idx->child_cnt); |
613 | if (child_cnt < 1 || child_cnt > c->fanout) { |
614 | err = 1; |
615 | goto out_dump; |
616 | } |
617 | if (first) { |
618 | first = 0; |
619 | /* Check root level and sqnum */ |
620 | if (le16_to_cpu(idx->level) != d->old_zroot_level) { |
621 | err = 2; |
622 | goto out_dump; |
623 | } |
624 | if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) { |
625 | err = 3; |
626 | goto out_dump; |
627 | } |
628 | /* Set last values as though root had a parent */ |
629 | last_level = le16_to_cpu(idx->level) + 1; |
630 | last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1; |
631 | key_read(c, from: ubifs_idx_key(c, idx), to: &lower_key); |
632 | highest_ino_key(c, key: &upper_key, INUM_WATERMARK); |
633 | } |
634 | key_copy(c, from: &upper_key, to: &i->upper_key); |
635 | if (le16_to_cpu(idx->level) != last_level - 1) { |
636 | err = 3; |
637 | goto out_dump; |
638 | } |
639 | /* |
640 | * The index is always written bottom up hence a child's sqnum |
641 | * is always less than the parents. |
642 | */ |
643 | if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) { |
644 | err = 4; |
645 | goto out_dump; |
646 | } |
647 | /* Check key range */ |
648 | key_read(c, from: ubifs_idx_key(c, idx), to: &l_key); |
649 | br = ubifs_idx_branch(c, idx, bnum: child_cnt - 1); |
650 | key_read(c, from: &br->key, to: &u_key); |
651 | if (keys_cmp(c, key1: &lower_key, key2: &l_key) > 0) { |
652 | err = 5; |
653 | goto out_dump; |
654 | } |
655 | if (keys_cmp(c, key1: &upper_key, key2: &u_key) < 0) { |
656 | err = 6; |
657 | goto out_dump; |
658 | } |
659 | if (keys_cmp(c, key1: &upper_key, key2: &u_key) == 0) |
660 | if (!is_hash_key(c, key: &u_key)) { |
661 | err = 7; |
662 | goto out_dump; |
663 | } |
664 | /* Go to next index node */ |
665 | if (le16_to_cpu(idx->level) == 0) { |
666 | /* At the bottom, so go up until can go right */ |
667 | while (1) { |
668 | /* Drop the bottom of the list */ |
669 | list_del(entry: &i->list); |
670 | kfree(objp: i); |
671 | /* No more list means we are done */ |
672 | if (list_empty(head: &list)) |
673 | goto out; |
674 | /* Look at the new bottom */ |
675 | i = list_entry(list.prev, struct idx_node, |
676 | list); |
677 | idx = &i->idx; |
678 | /* Can we go right */ |
679 | if (iip + 1 < le16_to_cpu(idx->child_cnt)) { |
680 | iip = iip + 1; |
681 | break; |
682 | } else |
683 | /* Nope, so go up again */ |
684 | iip = i->iip; |
685 | } |
686 | } else |
687 | /* Go down left */ |
688 | iip = 0; |
689 | /* |
690 | * We have the parent in 'idx' and now we set up for reading the |
691 | * child pointed to by slot 'iip'. |
692 | */ |
693 | last_level = le16_to_cpu(idx->level); |
694 | last_sqnum = le64_to_cpu(idx->ch.sqnum); |
695 | br = ubifs_idx_branch(c, idx, bnum: iip); |
696 | lnum = le32_to_cpu(br->lnum); |
697 | offs = le32_to_cpu(br->offs); |
698 | len = le32_to_cpu(br->len); |
699 | key_read(c, from: &br->key, to: &lower_key); |
700 | if (iip + 1 < le16_to_cpu(idx->child_cnt)) { |
701 | br = ubifs_idx_branch(c, idx, bnum: iip + 1); |
702 | key_read(c, from: &br->key, to: &upper_key); |
703 | } else |
704 | key_copy(c, from: &i->upper_key, to: &upper_key); |
705 | } |
706 | out: |
707 | err = dbg_old_index_check_init(c, zroot); |
708 | if (err) |
709 | goto out_free; |
710 | |
711 | return 0; |
712 | |
713 | out_dump: |
714 | ubifs_err(c, fmt: "dumping index node (iip=%d)" , i->iip); |
715 | ubifs_dump_node(c, node: idx, node_len: ubifs_idx_node_sz(c, child_cnt: c->fanout)); |
716 | list_del(entry: &i->list); |
717 | kfree(objp: i); |
718 | if (!list_empty(head: &list)) { |
719 | i = list_entry(list.prev, struct idx_node, list); |
720 | ubifs_err(c, fmt: "dumping parent index node" ); |
721 | ubifs_dump_node(c, node: &i->idx, node_len: ubifs_idx_node_sz(c, child_cnt: c->fanout)); |
722 | } |
723 | out_free: |
724 | while (!list_empty(head: &list)) { |
725 | i = list_entry(list.next, struct idx_node, list); |
726 | list_del(entry: &i->list); |
727 | kfree(objp: i); |
728 | } |
729 | ubifs_err(c, fmt: "failed, error %d" , err); |
730 | if (err > 0) |
731 | err = -EINVAL; |
732 | return err; |
733 | } |
734 | |