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