xref: /openbmc/u-boot/fs/ubifs/orphan.c (revision 3bf801a2)
1 /*
2  * This file is part of UBIFS.
3  *
4  * Copyright (C) 2006-2008 Nokia Corporation.
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  *
8  * Author: Adrian Hunter
9  */
10 
11 #include <linux/err.h>
12 #include "ubifs.h"
13 
14 /*
15  * An orphan is an inode number whose inode node has been committed to the index
16  * with a link count of zero. That happens when an open file is deleted
17  * (unlinked) and then a commit is run. In the normal course of events the inode
18  * would be deleted when the file is closed. However in the case of an unclean
19  * unmount, orphans need to be accounted for. After an unclean unmount, the
20  * orphans' inodes must be deleted which means either scanning the entire index
21  * looking for them, or keeping a list on flash somewhere. This unit implements
22  * the latter approach.
23  *
24  * The orphan area is a fixed number of LEBs situated between the LPT area and
25  * the main area. The number of orphan area LEBs is specified when the file
26  * system is created. The minimum number is 1. The size of the orphan area
27  * should be so that it can hold the maximum number of orphans that are expected
28  * to ever exist at one time.
29  *
30  * The number of orphans that can fit in a LEB is:
31  *
32  *         (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
33  *
34  * For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
35  *
36  * Orphans are accumulated in a rb-tree. When an inode's link count drops to
37  * zero, the inode number is added to the rb-tree. It is removed from the tree
38  * when the inode is deleted.  Any new orphans that are in the orphan tree when
39  * the commit is run, are written to the orphan area in 1 or more orphan nodes.
40  * If the orphan area is full, it is consolidated to make space.  There is
41  * always enough space because validation prevents the user from creating more
42  * than the maximum number of orphans allowed.
43  */
44 
45 static int dbg_check_orphans(struct ubifs_info *c);
46 
47 /**
48  * ubifs_add_orphan - add an orphan.
49  * @c: UBIFS file-system description object
50  * @inum: orphan inode number
51  *
52  * Add an orphan. This function is called when an inodes link count drops to
53  * zero.
54  */
55 int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
56 {
57 	struct ubifs_orphan *orphan, *o;
58 	struct rb_node **p, *parent = NULL;
59 
60 	orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS);
61 	if (!orphan)
62 		return -ENOMEM;
63 	orphan->inum = inum;
64 	orphan->new = 1;
65 
66 	spin_lock(&c->orphan_lock);
67 	if (c->tot_orphans >= c->max_orphans) {
68 		spin_unlock(&c->orphan_lock);
69 		kfree(orphan);
70 		return -ENFILE;
71 	}
72 	p = &c->orph_tree.rb_node;
73 	while (*p) {
74 		parent = *p;
75 		o = rb_entry(parent, struct ubifs_orphan, rb);
76 		if (inum < o->inum)
77 			p = &(*p)->rb_left;
78 		else if (inum > o->inum)
79 			p = &(*p)->rb_right;
80 		else {
81 			ubifs_err("orphaned twice");
82 			spin_unlock(&c->orphan_lock);
83 			kfree(orphan);
84 			return 0;
85 		}
86 	}
87 	c->tot_orphans += 1;
88 	c->new_orphans += 1;
89 	rb_link_node(&orphan->rb, parent, p);
90 	rb_insert_color(&orphan->rb, &c->orph_tree);
91 	list_add_tail(&orphan->list, &c->orph_list);
92 	list_add_tail(&orphan->new_list, &c->orph_new);
93 	spin_unlock(&c->orphan_lock);
94 	dbg_gen("ino %lu", (unsigned long)inum);
95 	return 0;
96 }
97 
98 /**
99  * ubifs_delete_orphan - delete an orphan.
100  * @c: UBIFS file-system description object
101  * @inum: orphan inode number
102  *
103  * Delete an orphan. This function is called when an inode is deleted.
104  */
105 void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
106 {
107 	struct ubifs_orphan *o;
108 	struct rb_node *p;
109 
110 	spin_lock(&c->orphan_lock);
111 	p = c->orph_tree.rb_node;
112 	while (p) {
113 		o = rb_entry(p, struct ubifs_orphan, rb);
114 		if (inum < o->inum)
115 			p = p->rb_left;
116 		else if (inum > o->inum)
117 			p = p->rb_right;
118 		else {
119 			if (o->del) {
120 				spin_unlock(&c->orphan_lock);
121 				dbg_gen("deleted twice ino %lu",
122 					(unsigned long)inum);
123 				return;
124 			}
125 			if (o->cmt) {
126 				o->del = 1;
127 				o->dnext = c->orph_dnext;
128 				c->orph_dnext = o;
129 				spin_unlock(&c->orphan_lock);
130 				dbg_gen("delete later ino %lu",
131 					(unsigned long)inum);
132 				return;
133 			}
134 			rb_erase(p, &c->orph_tree);
135 			list_del(&o->list);
136 			c->tot_orphans -= 1;
137 			if (o->new) {
138 				list_del(&o->new_list);
139 				c->new_orphans -= 1;
140 			}
141 			spin_unlock(&c->orphan_lock);
142 			kfree(o);
143 			dbg_gen("inum %lu", (unsigned long)inum);
144 			return;
145 		}
146 	}
147 	spin_unlock(&c->orphan_lock);
148 	ubifs_err("missing orphan ino %lu", (unsigned long)inum);
149 	dump_stack();
150 }
151 
152 /**
153  * ubifs_orphan_start_commit - start commit of orphans.
154  * @c: UBIFS file-system description object
155  *
156  * Start commit of orphans.
157  */
158 int ubifs_orphan_start_commit(struct ubifs_info *c)
159 {
160 	struct ubifs_orphan *orphan, **last;
161 
162 	spin_lock(&c->orphan_lock);
163 	last = &c->orph_cnext;
164 	list_for_each_entry(orphan, &c->orph_new, new_list) {
165 		ubifs_assert(orphan->new);
166 		ubifs_assert(!orphan->cmt);
167 		orphan->new = 0;
168 		orphan->cmt = 1;
169 		*last = orphan;
170 		last = &orphan->cnext;
171 	}
172 	*last = NULL;
173 	c->cmt_orphans = c->new_orphans;
174 	c->new_orphans = 0;
175 	dbg_cmt("%d orphans to commit", c->cmt_orphans);
176 	INIT_LIST_HEAD(&c->orph_new);
177 	if (c->tot_orphans == 0)
178 		c->no_orphs = 1;
179 	else
180 		c->no_orphs = 0;
181 	spin_unlock(&c->orphan_lock);
182 	return 0;
183 }
184 
185 /**
186  * avail_orphs - calculate available space.
187  * @c: UBIFS file-system description object
188  *
189  * This function returns the number of orphans that can be written in the
190  * available space.
191  */
192 static int avail_orphs(struct ubifs_info *c)
193 {
194 	int avail_lebs, avail, gap;
195 
196 	avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1;
197 	avail = avail_lebs *
198 	       ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
199 	gap = c->leb_size - c->ohead_offs;
200 	if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64))
201 		avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
202 	return avail;
203 }
204 
205 /**
206  * tot_avail_orphs - calculate total space.
207  * @c: UBIFS file-system description object
208  *
209  * This function returns the number of orphans that can be written in half
210  * the total space. That leaves half the space for adding new orphans.
211  */
212 static int tot_avail_orphs(struct ubifs_info *c)
213 {
214 	int avail_lebs, avail;
215 
216 	avail_lebs = c->orph_lebs;
217 	avail = avail_lebs *
218 	       ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
219 	return avail / 2;
220 }
221 
222 /**
223  * do_write_orph_node - write a node to the orphan head.
224  * @c: UBIFS file-system description object
225  * @len: length of node
226  * @atomic: write atomically
227  *
228  * This function writes a node to the orphan head from the orphan buffer. If
229  * %atomic is not zero, then the write is done atomically. On success, %0 is
230  * returned, otherwise a negative error code is returned.
231  */
232 static int do_write_orph_node(struct ubifs_info *c, int len, int atomic)
233 {
234 	int err = 0;
235 
236 	if (atomic) {
237 		ubifs_assert(c->ohead_offs == 0);
238 		ubifs_prepare_node(c, c->orph_buf, len, 1);
239 		len = ALIGN(len, c->min_io_size);
240 		err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len);
241 	} else {
242 		if (c->ohead_offs == 0) {
243 			/* Ensure LEB has been unmapped */
244 			err = ubifs_leb_unmap(c, c->ohead_lnum);
245 			if (err)
246 				return err;
247 		}
248 		err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum,
249 				       c->ohead_offs);
250 	}
251 	return err;
252 }
253 
254 /**
255  * write_orph_node - write an orphan node.
256  * @c: UBIFS file-system description object
257  * @atomic: write atomically
258  *
259  * This function builds an orphan node from the cnext list and writes it to the
260  * orphan head. On success, %0 is returned, otherwise a negative error code
261  * is returned.
262  */
263 static int write_orph_node(struct ubifs_info *c, int atomic)
264 {
265 	struct ubifs_orphan *orphan, *cnext;
266 	struct ubifs_orph_node *orph;
267 	int gap, err, len, cnt, i;
268 
269 	ubifs_assert(c->cmt_orphans > 0);
270 	gap = c->leb_size - c->ohead_offs;
271 	if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) {
272 		c->ohead_lnum += 1;
273 		c->ohead_offs = 0;
274 		gap = c->leb_size;
275 		if (c->ohead_lnum > c->orph_last) {
276 			/*
277 			 * We limit the number of orphans so that this should
278 			 * never happen.
279 			 */
280 			ubifs_err("out of space in orphan area");
281 			return -EINVAL;
282 		}
283 	}
284 	cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
285 	if (cnt > c->cmt_orphans)
286 		cnt = c->cmt_orphans;
287 	len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64);
288 	ubifs_assert(c->orph_buf);
289 	orph = c->orph_buf;
290 	orph->ch.node_type = UBIFS_ORPH_NODE;
291 	spin_lock(&c->orphan_lock);
292 	cnext = c->orph_cnext;
293 	for (i = 0; i < cnt; i++) {
294 		orphan = cnext;
295 		ubifs_assert(orphan->cmt);
296 		orph->inos[i] = cpu_to_le64(orphan->inum);
297 		orphan->cmt = 0;
298 		cnext = orphan->cnext;
299 		orphan->cnext = NULL;
300 	}
301 	c->orph_cnext = cnext;
302 	c->cmt_orphans -= cnt;
303 	spin_unlock(&c->orphan_lock);
304 	if (c->cmt_orphans)
305 		orph->cmt_no = cpu_to_le64(c->cmt_no);
306 	else
307 		/* Mark the last node of the commit */
308 		orph->cmt_no = cpu_to_le64((c->cmt_no) | (1ULL << 63));
309 	ubifs_assert(c->ohead_offs + len <= c->leb_size);
310 	ubifs_assert(c->ohead_lnum >= c->orph_first);
311 	ubifs_assert(c->ohead_lnum <= c->orph_last);
312 	err = do_write_orph_node(c, len, atomic);
313 	c->ohead_offs += ALIGN(len, c->min_io_size);
314 	c->ohead_offs = ALIGN(c->ohead_offs, 8);
315 	return err;
316 }
317 
318 /**
319  * write_orph_nodes - write orphan nodes until there are no more to commit.
320  * @c: UBIFS file-system description object
321  * @atomic: write atomically
322  *
323  * This function writes orphan nodes for all the orphans to commit. On success,
324  * %0 is returned, otherwise a negative error code is returned.
325  */
326 static int write_orph_nodes(struct ubifs_info *c, int atomic)
327 {
328 	int err;
329 
330 	while (c->cmt_orphans > 0) {
331 		err = write_orph_node(c, atomic);
332 		if (err)
333 			return err;
334 	}
335 	if (atomic) {
336 		int lnum;
337 
338 		/* Unmap any unused LEBs after consolidation */
339 		lnum = c->ohead_lnum + 1;
340 		for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
341 			err = ubifs_leb_unmap(c, lnum);
342 			if (err)
343 				return err;
344 		}
345 	}
346 	return 0;
347 }
348 
349 /**
350  * consolidate - consolidate the orphan area.
351  * @c: UBIFS file-system description object
352  *
353  * This function enables consolidation by putting all the orphans into the list
354  * to commit. The list is in the order that the orphans were added, and the
355  * LEBs are written atomically in order, so at no time can orphans be lost by
356  * an unclean unmount.
357  *
358  * This function returns %0 on success and a negative error code on failure.
359  */
360 static int consolidate(struct ubifs_info *c)
361 {
362 	int tot_avail = tot_avail_orphs(c), err = 0;
363 
364 	spin_lock(&c->orphan_lock);
365 	dbg_cmt("there is space for %d orphans and there are %d",
366 		tot_avail, c->tot_orphans);
367 	if (c->tot_orphans - c->new_orphans <= tot_avail) {
368 		struct ubifs_orphan *orphan, **last;
369 		int cnt = 0;
370 
371 		/* Change the cnext list to include all non-new orphans */
372 		last = &c->orph_cnext;
373 		list_for_each_entry(orphan, &c->orph_list, list) {
374 			if (orphan->new)
375 				continue;
376 			orphan->cmt = 1;
377 			*last = orphan;
378 			last = &orphan->cnext;
379 			cnt += 1;
380 		}
381 		*last = NULL;
382 		ubifs_assert(cnt == c->tot_orphans - c->new_orphans);
383 		c->cmt_orphans = cnt;
384 		c->ohead_lnum = c->orph_first;
385 		c->ohead_offs = 0;
386 	} else {
387 		/*
388 		 * We limit the number of orphans so that this should
389 		 * never happen.
390 		 */
391 		ubifs_err("out of space in orphan area");
392 		err = -EINVAL;
393 	}
394 	spin_unlock(&c->orphan_lock);
395 	return err;
396 }
397 
398 /**
399  * commit_orphans - commit orphans.
400  * @c: UBIFS file-system description object
401  *
402  * This function commits orphans to flash. On success, %0 is returned,
403  * otherwise a negative error code is returned.
404  */
405 static int commit_orphans(struct ubifs_info *c)
406 {
407 	int avail, atomic = 0, err;
408 
409 	ubifs_assert(c->cmt_orphans > 0);
410 	avail = avail_orphs(c);
411 	if (avail < c->cmt_orphans) {
412 		/* Not enough space to write new orphans, so consolidate */
413 		err = consolidate(c);
414 		if (err)
415 			return err;
416 		atomic = 1;
417 	}
418 	err = write_orph_nodes(c, atomic);
419 	return err;
420 }
421 
422 /**
423  * erase_deleted - erase the orphans marked for deletion.
424  * @c: UBIFS file-system description object
425  *
426  * During commit, the orphans being committed cannot be deleted, so they are
427  * marked for deletion and deleted by this function. Also, the recovery
428  * adds killed orphans to the deletion list, and therefore they are deleted
429  * here too.
430  */
431 static void erase_deleted(struct ubifs_info *c)
432 {
433 	struct ubifs_orphan *orphan, *dnext;
434 
435 	spin_lock(&c->orphan_lock);
436 	dnext = c->orph_dnext;
437 	while (dnext) {
438 		orphan = dnext;
439 		dnext = orphan->dnext;
440 		ubifs_assert(!orphan->new);
441 		ubifs_assert(orphan->del);
442 		rb_erase(&orphan->rb, &c->orph_tree);
443 		list_del(&orphan->list);
444 		c->tot_orphans -= 1;
445 		dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum);
446 		kfree(orphan);
447 	}
448 	c->orph_dnext = NULL;
449 	spin_unlock(&c->orphan_lock);
450 }
451 
452 /**
453  * ubifs_orphan_end_commit - end commit of orphans.
454  * @c: UBIFS file-system description object
455  *
456  * End commit of orphans.
457  */
458 int ubifs_orphan_end_commit(struct ubifs_info *c)
459 {
460 	int err;
461 
462 	if (c->cmt_orphans != 0) {
463 		err = commit_orphans(c);
464 		if (err)
465 			return err;
466 	}
467 	erase_deleted(c);
468 	err = dbg_check_orphans(c);
469 	return err;
470 }
471 
472 /**
473  * ubifs_clear_orphans - erase all LEBs used for orphans.
474  * @c: UBIFS file-system description object
475  *
476  * If recovery is not required, then the orphans from the previous session
477  * are not needed. This function locates the LEBs used to record
478  * orphans, and un-maps them.
479  */
480 int ubifs_clear_orphans(struct ubifs_info *c)
481 {
482 	int lnum, err;
483 
484 	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
485 		err = ubifs_leb_unmap(c, lnum);
486 		if (err)
487 			return err;
488 	}
489 	c->ohead_lnum = c->orph_first;
490 	c->ohead_offs = 0;
491 	return 0;
492 }
493 
494 /**
495  * insert_dead_orphan - insert an orphan.
496  * @c: UBIFS file-system description object
497  * @inum: orphan inode number
498  *
499  * This function is a helper to the 'do_kill_orphans()' function. The orphan
500  * must be kept until the next commit, so it is added to the rb-tree and the
501  * deletion list.
502  */
503 static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
504 {
505 	struct ubifs_orphan *orphan, *o;
506 	struct rb_node **p, *parent = NULL;
507 
508 	orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
509 	if (!orphan)
510 		return -ENOMEM;
511 	orphan->inum = inum;
512 
513 	p = &c->orph_tree.rb_node;
514 	while (*p) {
515 		parent = *p;
516 		o = rb_entry(parent, struct ubifs_orphan, rb);
517 		if (inum < o->inum)
518 			p = &(*p)->rb_left;
519 		else if (inum > o->inum)
520 			p = &(*p)->rb_right;
521 		else {
522 			/* Already added - no problem */
523 			kfree(orphan);
524 			return 0;
525 		}
526 	}
527 	c->tot_orphans += 1;
528 	rb_link_node(&orphan->rb, parent, p);
529 	rb_insert_color(&orphan->rb, &c->orph_tree);
530 	list_add_tail(&orphan->list, &c->orph_list);
531 	orphan->del = 1;
532 	orphan->dnext = c->orph_dnext;
533 	c->orph_dnext = orphan;
534 	dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
535 		c->new_orphans, c->tot_orphans);
536 	return 0;
537 }
538 
539 /**
540  * do_kill_orphans - remove orphan inodes from the index.
541  * @c: UBIFS file-system description object
542  * @sleb: scanned LEB
543  * @last_cmt_no: cmt_no of last orphan node read is passed and returned here
544  * @outofdate: whether the LEB is out of date is returned here
545  * @last_flagged: whether the end orphan node is encountered
546  *
547  * This function is a helper to the 'kill_orphans()' function. It goes through
548  * every orphan node in a LEB and for every inode number recorded, removes
549  * all keys for that inode from the TNC.
550  */
551 static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
552 			   unsigned long long *last_cmt_no, int *outofdate,
553 			   int *last_flagged)
554 {
555 	struct ubifs_scan_node *snod;
556 	struct ubifs_orph_node *orph;
557 	unsigned long long cmt_no;
558 	ino_t inum;
559 	int i, n, err, first = 1;
560 
561 	list_for_each_entry(snod, &sleb->nodes, list) {
562 		if (snod->type != UBIFS_ORPH_NODE) {
563 			ubifs_err("invalid node type %d in orphan area at %d:%d",
564 				  snod->type, sleb->lnum, snod->offs);
565 			ubifs_dump_node(c, snod->node);
566 			return -EINVAL;
567 		}
568 
569 		orph = snod->node;
570 
571 		/* Check commit number */
572 		cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
573 		/*
574 		 * The commit number on the master node may be less, because
575 		 * of a failed commit. If there are several failed commits in a
576 		 * row, the commit number written on orphan nodes will continue
577 		 * to increase (because the commit number is adjusted here) even
578 		 * though the commit number on the master node stays the same
579 		 * because the master node has not been re-written.
580 		 */
581 		if (cmt_no > c->cmt_no)
582 			c->cmt_no = cmt_no;
583 		if (cmt_no < *last_cmt_no && *last_flagged) {
584 			/*
585 			 * The last orphan node had a higher commit number and
586 			 * was flagged as the last written for that commit
587 			 * number. That makes this orphan node, out of date.
588 			 */
589 			if (!first) {
590 				ubifs_err("out of order commit number %llu in orphan node at %d:%d",
591 					  cmt_no, sleb->lnum, snod->offs);
592 				ubifs_dump_node(c, snod->node);
593 				return -EINVAL;
594 			}
595 			dbg_rcvry("out of date LEB %d", sleb->lnum);
596 			*outofdate = 1;
597 			return 0;
598 		}
599 
600 		if (first)
601 			first = 0;
602 
603 		n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
604 		for (i = 0; i < n; i++) {
605 			inum = le64_to_cpu(orph->inos[i]);
606 			dbg_rcvry("deleting orphaned inode %lu",
607 				  (unsigned long)inum);
608 			err = ubifs_tnc_remove_ino(c, inum);
609 			if (err)
610 				return err;
611 			err = insert_dead_orphan(c, inum);
612 			if (err)
613 				return err;
614 		}
615 
616 		*last_cmt_no = cmt_no;
617 		if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
618 			dbg_rcvry("last orph node for commit %llu at %d:%d",
619 				  cmt_no, sleb->lnum, snod->offs);
620 			*last_flagged = 1;
621 		} else
622 			*last_flagged = 0;
623 	}
624 
625 	return 0;
626 }
627 
628 /**
629  * kill_orphans - remove all orphan inodes from the index.
630  * @c: UBIFS file-system description object
631  *
632  * If recovery is required, then orphan inodes recorded during the previous
633  * session (which ended with an unclean unmount) must be deleted from the index.
634  * This is done by updating the TNC, but since the index is not updated until
635  * the next commit, the LEBs where the orphan information is recorded are not
636  * erased until the next commit.
637  */
638 static int kill_orphans(struct ubifs_info *c)
639 {
640 	unsigned long long last_cmt_no = 0;
641 	int lnum, err = 0, outofdate = 0, last_flagged = 0;
642 
643 	c->ohead_lnum = c->orph_first;
644 	c->ohead_offs = 0;
645 	/* Check no-orphans flag and skip this if no orphans */
646 	if (c->no_orphs) {
647 		dbg_rcvry("no orphans");
648 		return 0;
649 	}
650 	/*
651 	 * Orph nodes always start at c->orph_first and are written to each
652 	 * successive LEB in turn. Generally unused LEBs will have been unmapped
653 	 * but may contain out of date orphan nodes if the unmap didn't go
654 	 * through. In addition, the last orphan node written for each commit is
655 	 * marked (top bit of orph->cmt_no is set to 1). It is possible that
656 	 * there are orphan nodes from the next commit (i.e. the commit did not
657 	 * complete successfully). In that case, no orphans will have been lost
658 	 * due to the way that orphans are written, and any orphans added will
659 	 * be valid orphans anyway and so can be deleted.
660 	 */
661 	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
662 		struct ubifs_scan_leb *sleb;
663 
664 		dbg_rcvry("LEB %d", lnum);
665 		sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
666 		if (IS_ERR(sleb)) {
667 			if (PTR_ERR(sleb) == -EUCLEAN)
668 				sleb = ubifs_recover_leb(c, lnum, 0,
669 							 c->sbuf, -1);
670 			if (IS_ERR(sleb)) {
671 				err = PTR_ERR(sleb);
672 				break;
673 			}
674 		}
675 		err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
676 				      &last_flagged);
677 		if (err || outofdate) {
678 			ubifs_scan_destroy(sleb);
679 			break;
680 		}
681 		if (sleb->endpt) {
682 			c->ohead_lnum = lnum;
683 			c->ohead_offs = sleb->endpt;
684 		}
685 		ubifs_scan_destroy(sleb);
686 	}
687 	return err;
688 }
689 
690 /**
691  * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
692  * @c: UBIFS file-system description object
693  * @unclean: indicates recovery from unclean unmount
694  * @read_only: indicates read only mount
695  *
696  * This function is called when mounting to erase orphans from the previous
697  * session. If UBIFS was not unmounted cleanly, then the inodes recorded as
698  * orphans are deleted.
699  */
700 int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
701 {
702 	int err = 0;
703 
704 	c->max_orphans = tot_avail_orphs(c);
705 
706 	if (!read_only) {
707 		c->orph_buf = vmalloc(c->leb_size);
708 		if (!c->orph_buf)
709 			return -ENOMEM;
710 	}
711 
712 	if (unclean)
713 		err = kill_orphans(c);
714 	else if (!read_only)
715 		err = ubifs_clear_orphans(c);
716 
717 	return err;
718 }
719 
720 /*
721  * Everything below is related to debugging.
722  */
723 
724 struct check_orphan {
725 	struct rb_node rb;
726 	ino_t inum;
727 };
728 
729 struct check_info {
730 	unsigned long last_ino;
731 	unsigned long tot_inos;
732 	unsigned long missing;
733 	unsigned long long leaf_cnt;
734 	struct ubifs_ino_node *node;
735 	struct rb_root root;
736 };
737 
738 static int dbg_find_orphan(struct ubifs_info *c, ino_t inum)
739 {
740 	struct ubifs_orphan *o;
741 	struct rb_node *p;
742 
743 	spin_lock(&c->orphan_lock);
744 	p = c->orph_tree.rb_node;
745 	while (p) {
746 		o = rb_entry(p, struct ubifs_orphan, rb);
747 		if (inum < o->inum)
748 			p = p->rb_left;
749 		else if (inum > o->inum)
750 			p = p->rb_right;
751 		else {
752 			spin_unlock(&c->orphan_lock);
753 			return 1;
754 		}
755 	}
756 	spin_unlock(&c->orphan_lock);
757 	return 0;
758 }
759 
760 static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
761 {
762 	struct check_orphan *orphan, *o;
763 	struct rb_node **p, *parent = NULL;
764 
765 	orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
766 	if (!orphan)
767 		return -ENOMEM;
768 	orphan->inum = inum;
769 
770 	p = &root->rb_node;
771 	while (*p) {
772 		parent = *p;
773 		o = rb_entry(parent, struct check_orphan, rb);
774 		if (inum < o->inum)
775 			p = &(*p)->rb_left;
776 		else if (inum > o->inum)
777 			p = &(*p)->rb_right;
778 		else {
779 			kfree(orphan);
780 			return 0;
781 		}
782 	}
783 	rb_link_node(&orphan->rb, parent, p);
784 	rb_insert_color(&orphan->rb, root);
785 	return 0;
786 }
787 
788 static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
789 {
790 	struct check_orphan *o;
791 	struct rb_node *p;
792 
793 	p = root->rb_node;
794 	while (p) {
795 		o = rb_entry(p, struct check_orphan, rb);
796 		if (inum < o->inum)
797 			p = p->rb_left;
798 		else if (inum > o->inum)
799 			p = p->rb_right;
800 		else
801 			return 1;
802 	}
803 	return 0;
804 }
805 
806 static void dbg_free_check_tree(struct rb_root *root)
807 {
808 	struct check_orphan *o, *n;
809 
810 	rbtree_postorder_for_each_entry_safe(o, n, root, rb)
811 		kfree(o);
812 }
813 
814 static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
815 			    void *priv)
816 {
817 	struct check_info *ci = priv;
818 	ino_t inum;
819 	int err;
820 
821 	inum = key_inum(c, &zbr->key);
822 	if (inum != ci->last_ino) {
823 		/* Lowest node type is the inode node, so it comes first */
824 		if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
825 			ubifs_err("found orphan node ino %lu, type %d",
826 				  (unsigned long)inum, key_type(c, &zbr->key));
827 		ci->last_ino = inum;
828 		ci->tot_inos += 1;
829 		err = ubifs_tnc_read_node(c, zbr, ci->node);
830 		if (err) {
831 			ubifs_err("node read failed, error %d", err);
832 			return err;
833 		}
834 		if (ci->node->nlink == 0)
835 			/* Must be recorded as an orphan */
836 			if (!dbg_find_check_orphan(&ci->root, inum) &&
837 			    !dbg_find_orphan(c, inum)) {
838 				ubifs_err("missing orphan, ino %lu",
839 					  (unsigned long)inum);
840 				ci->missing += 1;
841 			}
842 	}
843 	ci->leaf_cnt += 1;
844 	return 0;
845 }
846 
847 static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
848 {
849 	struct ubifs_scan_node *snod;
850 	struct ubifs_orph_node *orph;
851 	ino_t inum;
852 	int i, n, err;
853 
854 	list_for_each_entry(snod, &sleb->nodes, list) {
855 		cond_resched();
856 		if (snod->type != UBIFS_ORPH_NODE)
857 			continue;
858 		orph = snod->node;
859 		n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
860 		for (i = 0; i < n; i++) {
861 			inum = le64_to_cpu(orph->inos[i]);
862 			err = dbg_ins_check_orphan(&ci->root, inum);
863 			if (err)
864 				return err;
865 		}
866 	}
867 	return 0;
868 }
869 
870 static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
871 {
872 	int lnum, err = 0;
873 	void *buf;
874 
875 	/* Check no-orphans flag and skip this if no orphans */
876 	if (c->no_orphs)
877 		return 0;
878 
879 	buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
880 	if (!buf) {
881 		ubifs_err("cannot allocate memory to check orphans");
882 		return 0;
883 	}
884 
885 	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
886 		struct ubifs_scan_leb *sleb;
887 
888 		sleb = ubifs_scan(c, lnum, 0, buf, 0);
889 		if (IS_ERR(sleb)) {
890 			err = PTR_ERR(sleb);
891 			break;
892 		}
893 
894 		err = dbg_read_orphans(ci, sleb);
895 		ubifs_scan_destroy(sleb);
896 		if (err)
897 			break;
898 	}
899 
900 	vfree(buf);
901 	return err;
902 }
903 
904 static int dbg_check_orphans(struct ubifs_info *c)
905 {
906 	struct check_info ci;
907 	int err;
908 
909 	if (!dbg_is_chk_orph(c))
910 		return 0;
911 
912 	ci.last_ino = 0;
913 	ci.tot_inos = 0;
914 	ci.missing  = 0;
915 	ci.leaf_cnt = 0;
916 	ci.root = RB_ROOT;
917 	ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
918 	if (!ci.node) {
919 		ubifs_err("out of memory");
920 		return -ENOMEM;
921 	}
922 
923 	err = dbg_scan_orphans(c, &ci);
924 	if (err)
925 		goto out;
926 
927 	err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
928 	if (err) {
929 		ubifs_err("cannot scan TNC, error %d", err);
930 		goto out;
931 	}
932 
933 	if (ci.missing) {
934 		ubifs_err("%lu missing orphan(s)", ci.missing);
935 		err = -EINVAL;
936 		goto out;
937 	}
938 
939 	dbg_cmt("last inode number is %lu", ci.last_ino);
940 	dbg_cmt("total number of inodes is %lu", ci.tot_inos);
941 	dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
942 
943 out:
944 	dbg_free_check_tree(&ci.root);
945 	kfree(ci.node);
946 	return err;
947 }
948