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TOMOYO Linux Cross Reference
Linux/fs/ubifs/orphan.c

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  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  * Author: Adrian Hunter
 20  */
 21 
 22 #include "ubifs.h"
 23 
 24 /*
 25  * An orphan is an inode number whose inode node has been committed to the index
 26  * with a link count of zero. That happens when an open file is deleted
 27  * (unlinked) and then a commit is run. In the normal course of events the inode
 28  * would be deleted when the file is closed. However in the case of an unclean
 29  * unmount, orphans need to be accounted for. After an unclean unmount, the
 30  * orphans' inodes must be deleted which means either scanning the entire index
 31  * looking for them, or keeping a list on flash somewhere. This unit implements
 32  * the latter approach.
 33  *
 34  * The orphan area is a fixed number of LEBs situated between the LPT area and
 35  * the main area. The number of orphan area LEBs is specified when the file
 36  * system is created. The minimum number is 1. The size of the orphan area
 37  * should be so that it can hold the maximum number of orphans that are expected
 38  * to ever exist at one time.
 39  *
 40  * The number of orphans that can fit in a LEB is:
 41  *
 42  *         (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
 43  *
 44  * For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
 45  *
 46  * Orphans are accumulated in a rb-tree. When an inode's link count drops to
 47  * zero, the inode number is added to the rb-tree. It is removed from the tree
 48  * when the inode is deleted.  Any new orphans that are in the orphan tree when
 49  * the commit is run, are written to the orphan area in 1 or more orphan nodes.
 50  * If the orphan area is full, it is consolidated to make space.  There is
 51  * always enough space because validation prevents the user from creating more
 52  * than the maximum number of orphans allowed.
 53  */
 54 
 55 static int dbg_check_orphans(struct ubifs_info *c);
 56 
 57 /**
 58  * ubifs_add_orphan - add an orphan.
 59  * @c: UBIFS file-system description object
 60  * @inum: orphan inode number
 61  *
 62  * Add an orphan. This function is called when an inodes link count drops to
 63  * zero.
 64  */
 65 int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
 66 {
 67         struct ubifs_orphan *orphan, *o;
 68         struct rb_node **p, *parent = NULL;
 69 
 70         orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS);
 71         if (!orphan)
 72                 return -ENOMEM;
 73         orphan->inum = inum;
 74         orphan->new = 1;
 75 
 76         spin_lock(&c->orphan_lock);
 77         if (c->tot_orphans >= c->max_orphans) {
 78                 spin_unlock(&c->orphan_lock);
 79                 kfree(orphan);
 80                 return -ENFILE;
 81         }
 82         p = &c->orph_tree.rb_node;
 83         while (*p) {
 84                 parent = *p;
 85                 o = rb_entry(parent, struct ubifs_orphan, rb);
 86                 if (inum < o->inum)
 87                         p = &(*p)->rb_left;
 88                 else if (inum > o->inum)
 89                         p = &(*p)->rb_right;
 90                 else {
 91                         ubifs_err(c, "orphaned twice");
 92                         spin_unlock(&c->orphan_lock);
 93                         kfree(orphan);
 94                         return 0;
 95                 }
 96         }
 97         c->tot_orphans += 1;
 98         c->new_orphans += 1;
 99         rb_link_node(&orphan->rb, parent, p);
100         rb_insert_color(&orphan->rb, &c->orph_tree);
101         list_add_tail(&orphan->list, &c->orph_list);
102         list_add_tail(&orphan->new_list, &c->orph_new);
103         spin_unlock(&c->orphan_lock);
104         dbg_gen("ino %lu", (unsigned long)inum);
105         return 0;
106 }
107 
108 /**
109  * ubifs_delete_orphan - delete an orphan.
110  * @c: UBIFS file-system description object
111  * @inum: orphan inode number
112  *
113  * Delete an orphan. This function is called when an inode is deleted.
114  */
115 void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
116 {
117         struct ubifs_orphan *o;
118         struct rb_node *p;
119 
120         spin_lock(&c->orphan_lock);
121         p = c->orph_tree.rb_node;
122         while (p) {
123                 o = rb_entry(p, struct ubifs_orphan, rb);
124                 if (inum < o->inum)
125                         p = p->rb_left;
126                 else if (inum > o->inum)
127                         p = p->rb_right;
128                 else {
129                         if (o->del) {
130                                 spin_unlock(&c->orphan_lock);
131                                 dbg_gen("deleted twice ino %lu",
132                                         (unsigned long)inum);
133                                 return;
134                         }
135                         if (o->cmt) {
136                                 o->del = 1;
137                                 o->dnext = c->orph_dnext;
138                                 c->orph_dnext = o;
139                                 spin_unlock(&c->orphan_lock);
140                                 dbg_gen("delete later ino %lu",
141                                         (unsigned long)inum);
142                                 return;
143                         }
144                         rb_erase(p, &c->orph_tree);
145                         list_del(&o->list);
146                         c->tot_orphans -= 1;
147                         if (o->new) {
148                                 list_del(&o->new_list);
149                                 c->new_orphans -= 1;
150                         }
151                         spin_unlock(&c->orphan_lock);
152                         kfree(o);
153                         dbg_gen("inum %lu", (unsigned long)inum);
154                         return;
155                 }
156         }
157         spin_unlock(&c->orphan_lock);
158         ubifs_err(c, "missing orphan ino %lu", (unsigned long)inum);
159         dump_stack();
160 }
161 
162 /**
163  * ubifs_orphan_start_commit - start commit of orphans.
164  * @c: UBIFS file-system description object
165  *
166  * Start commit of orphans.
167  */
168 int ubifs_orphan_start_commit(struct ubifs_info *c)
169 {
170         struct ubifs_orphan *orphan, **last;
171 
172         spin_lock(&c->orphan_lock);
173         last = &c->orph_cnext;
174         list_for_each_entry(orphan, &c->orph_new, new_list) {
175                 ubifs_assert(orphan->new);
176                 ubifs_assert(!orphan->cmt);
177                 orphan->new = 0;
178                 orphan->cmt = 1;
179                 *last = orphan;
180                 last = &orphan->cnext;
181         }
182         *last = NULL;
183         c->cmt_orphans = c->new_orphans;
184         c->new_orphans = 0;
185         dbg_cmt("%d orphans to commit", c->cmt_orphans);
186         INIT_LIST_HEAD(&c->orph_new);
187         if (c->tot_orphans == 0)
188                 c->no_orphs = 1;
189         else
190                 c->no_orphs = 0;
191         spin_unlock(&c->orphan_lock);
192         return 0;
193 }
194 
195 /**
196  * avail_orphs - calculate available space.
197  * @c: UBIFS file-system description object
198  *
199  * This function returns the number of orphans that can be written in the
200  * available space.
201  */
202 static int avail_orphs(struct ubifs_info *c)
203 {
204         int avail_lebs, avail, gap;
205 
206         avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1;
207         avail = avail_lebs *
208                ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
209         gap = c->leb_size - c->ohead_offs;
210         if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64))
211                 avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
212         return avail;
213 }
214 
215 /**
216  * tot_avail_orphs - calculate total space.
217  * @c: UBIFS file-system description object
218  *
219  * This function returns the number of orphans that can be written in half
220  * the total space. That leaves half the space for adding new orphans.
221  */
222 static int tot_avail_orphs(struct ubifs_info *c)
223 {
224         int avail_lebs, avail;
225 
226         avail_lebs = c->orph_lebs;
227         avail = avail_lebs *
228                ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
229         return avail / 2;
230 }
231 
232 /**
233  * do_write_orph_node - write a node to the orphan head.
234  * @c: UBIFS file-system description object
235  * @len: length of node
236  * @atomic: write atomically
237  *
238  * This function writes a node to the orphan head from the orphan buffer. If
239  * %atomic is not zero, then the write is done atomically. On success, %0 is
240  * returned, otherwise a negative error code is returned.
241  */
242 static int do_write_orph_node(struct ubifs_info *c, int len, int atomic)
243 {
244         int err = 0;
245 
246         if (atomic) {
247                 ubifs_assert(c->ohead_offs == 0);
248                 ubifs_prepare_node(c, c->orph_buf, len, 1);
249                 len = ALIGN(len, c->min_io_size);
250                 err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len);
251         } else {
252                 if (c->ohead_offs == 0) {
253                         /* Ensure LEB has been unmapped */
254                         err = ubifs_leb_unmap(c, c->ohead_lnum);
255                         if (err)
256                                 return err;
257                 }
258                 err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum,
259                                        c->ohead_offs);
260         }
261         return err;
262 }
263 
264 /**
265  * write_orph_node - write an orphan node.
266  * @c: UBIFS file-system description object
267  * @atomic: write atomically
268  *
269  * This function builds an orphan node from the cnext list and writes it to the
270  * orphan head. On success, %0 is returned, otherwise a negative error code
271  * is returned.
272  */
273 static int write_orph_node(struct ubifs_info *c, int atomic)
274 {
275         struct ubifs_orphan *orphan, *cnext;
276         struct ubifs_orph_node *orph;
277         int gap, err, len, cnt, i;
278 
279         ubifs_assert(c->cmt_orphans > 0);
280         gap = c->leb_size - c->ohead_offs;
281         if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) {
282                 c->ohead_lnum += 1;
283                 c->ohead_offs = 0;
284                 gap = c->leb_size;
285                 if (c->ohead_lnum > c->orph_last) {
286                         /*
287                          * We limit the number of orphans so that this should
288                          * never happen.
289                          */
290                         ubifs_err(c, "out of space in orphan area");
291                         return -EINVAL;
292                 }
293         }
294         cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
295         if (cnt > c->cmt_orphans)
296                 cnt = c->cmt_orphans;
297         len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64);
298         ubifs_assert(c->orph_buf);
299         orph = c->orph_buf;
300         orph->ch.node_type = UBIFS_ORPH_NODE;
301         spin_lock(&c->orphan_lock);
302         cnext = c->orph_cnext;
303         for (i = 0; i < cnt; i++) {
304                 orphan = cnext;
305                 ubifs_assert(orphan->cmt);
306                 orph->inos[i] = cpu_to_le64(orphan->inum);
307                 orphan->cmt = 0;
308                 cnext = orphan->cnext;
309                 orphan->cnext = NULL;
310         }
311         c->orph_cnext = cnext;
312         c->cmt_orphans -= cnt;
313         spin_unlock(&c->orphan_lock);
314         if (c->cmt_orphans)
315                 orph->cmt_no = cpu_to_le64(c->cmt_no);
316         else
317                 /* Mark the last node of the commit */
318                 orph->cmt_no = cpu_to_le64((c->cmt_no) | (1ULL << 63));
319         ubifs_assert(c->ohead_offs + len <= c->leb_size);
320         ubifs_assert(c->ohead_lnum >= c->orph_first);
321         ubifs_assert(c->ohead_lnum <= c->orph_last);
322         err = do_write_orph_node(c, len, atomic);
323         c->ohead_offs += ALIGN(len, c->min_io_size);
324         c->ohead_offs = ALIGN(c->ohead_offs, 8);
325         return err;
326 }
327 
328 /**
329  * write_orph_nodes - write orphan nodes until there are no more to commit.
330  * @c: UBIFS file-system description object
331  * @atomic: write atomically
332  *
333  * This function writes orphan nodes for all the orphans to commit. On success,
334  * %0 is returned, otherwise a negative error code is returned.
335  */
336 static int write_orph_nodes(struct ubifs_info *c, int atomic)
337 {
338         int err;
339 
340         while (c->cmt_orphans > 0) {
341                 err = write_orph_node(c, atomic);
342                 if (err)
343                         return err;
344         }
345         if (atomic) {
346                 int lnum;
347 
348                 /* Unmap any unused LEBs after consolidation */
349                 for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
350                         err = ubifs_leb_unmap(c, lnum);
351                         if (err)
352                                 return err;
353                 }
354         }
355         return 0;
356 }
357 
358 /**
359  * consolidate - consolidate the orphan area.
360  * @c: UBIFS file-system description object
361  *
362  * This function enables consolidation by putting all the orphans into the list
363  * to commit. The list is in the order that the orphans were added, and the
364  * LEBs are written atomically in order, so at no time can orphans be lost by
365  * an unclean unmount.
366  *
367  * This function returns %0 on success and a negative error code on failure.
368  */
369 static int consolidate(struct ubifs_info *c)
370 {
371         int tot_avail = tot_avail_orphs(c), err = 0;
372 
373         spin_lock(&c->orphan_lock);
374         dbg_cmt("there is space for %d orphans and there are %d",
375                 tot_avail, c->tot_orphans);
376         if (c->tot_orphans - c->new_orphans <= tot_avail) {
377                 struct ubifs_orphan *orphan, **last;
378                 int cnt = 0;
379 
380                 /* Change the cnext list to include all non-new orphans */
381                 last = &c->orph_cnext;
382                 list_for_each_entry(orphan, &c->orph_list, list) {
383                         if (orphan->new)
384                                 continue;
385                         orphan->cmt = 1;
386                         *last = orphan;
387                         last = &orphan->cnext;
388                         cnt += 1;
389                 }
390                 *last = NULL;
391                 ubifs_assert(cnt == c->tot_orphans - c->new_orphans);
392                 c->cmt_orphans = cnt;
393                 c->ohead_lnum = c->orph_first;
394                 c->ohead_offs = 0;
395         } else {
396                 /*
397                  * We limit the number of orphans so that this should
398                  * never happen.
399                  */
400                 ubifs_err(c, "out of space in orphan area");
401                 err = -EINVAL;
402         }
403         spin_unlock(&c->orphan_lock);
404         return err;
405 }
406 
407 /**
408  * commit_orphans - commit orphans.
409  * @c: UBIFS file-system description object
410  *
411  * This function commits orphans to flash. On success, %0 is returned,
412  * otherwise a negative error code is returned.
413  */
414 static int commit_orphans(struct ubifs_info *c)
415 {
416         int avail, atomic = 0, err;
417 
418         ubifs_assert(c->cmt_orphans > 0);
419         avail = avail_orphs(c);
420         if (avail < c->cmt_orphans) {
421                 /* Not enough space to write new orphans, so consolidate */
422                 err = consolidate(c);
423                 if (err)
424                         return err;
425                 atomic = 1;
426         }
427         err = write_orph_nodes(c, atomic);
428         return err;
429 }
430 
431 /**
432  * erase_deleted - erase the orphans marked for deletion.
433  * @c: UBIFS file-system description object
434  *
435  * During commit, the orphans being committed cannot be deleted, so they are
436  * marked for deletion and deleted by this function. Also, the recovery
437  * adds killed orphans to the deletion list, and therefore they are deleted
438  * here too.
439  */
440 static void erase_deleted(struct ubifs_info *c)
441 {
442         struct ubifs_orphan *orphan, *dnext;
443 
444         spin_lock(&c->orphan_lock);
445         dnext = c->orph_dnext;
446         while (dnext) {
447                 orphan = dnext;
448                 dnext = orphan->dnext;
449                 ubifs_assert(!orphan->new);
450                 ubifs_assert(orphan->del);
451                 rb_erase(&orphan->rb, &c->orph_tree);
452                 list_del(&orphan->list);
453                 c->tot_orphans -= 1;
454                 dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum);
455                 kfree(orphan);
456         }
457         c->orph_dnext = NULL;
458         spin_unlock(&c->orphan_lock);
459 }
460 
461 /**
462  * ubifs_orphan_end_commit - end commit of orphans.
463  * @c: UBIFS file-system description object
464  *
465  * End commit of orphans.
466  */
467 int ubifs_orphan_end_commit(struct ubifs_info *c)
468 {
469         int err;
470 
471         if (c->cmt_orphans != 0) {
472                 err = commit_orphans(c);
473                 if (err)
474                         return err;
475         }
476         erase_deleted(c);
477         err = dbg_check_orphans(c);
478         return err;
479 }
480 
481 /**
482  * ubifs_clear_orphans - erase all LEBs used for orphans.
483  * @c: UBIFS file-system description object
484  *
485  * If recovery is not required, then the orphans from the previous session
486  * are not needed. This function locates the LEBs used to record
487  * orphans, and un-maps them.
488  */
489 int ubifs_clear_orphans(struct ubifs_info *c)
490 {
491         int lnum, err;
492 
493         for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
494                 err = ubifs_leb_unmap(c, lnum);
495                 if (err)
496                         return err;
497         }
498         c->ohead_lnum = c->orph_first;
499         c->ohead_offs = 0;
500         return 0;
501 }
502 
503 /**
504  * insert_dead_orphan - insert an orphan.
505  * @c: UBIFS file-system description object
506  * @inum: orphan inode number
507  *
508  * This function is a helper to the 'do_kill_orphans()' function. The orphan
509  * must be kept until the next commit, so it is added to the rb-tree and the
510  * deletion list.
511  */
512 static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
513 {
514         struct ubifs_orphan *orphan, *o;
515         struct rb_node **p, *parent = NULL;
516 
517         orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
518         if (!orphan)
519                 return -ENOMEM;
520         orphan->inum = inum;
521 
522         p = &c->orph_tree.rb_node;
523         while (*p) {
524                 parent = *p;
525                 o = rb_entry(parent, struct ubifs_orphan, rb);
526                 if (inum < o->inum)
527                         p = &(*p)->rb_left;
528                 else if (inum > o->inum)
529                         p = &(*p)->rb_right;
530                 else {
531                         /* Already added - no problem */
532                         kfree(orphan);
533                         return 0;
534                 }
535         }
536         c->tot_orphans += 1;
537         rb_link_node(&orphan->rb, parent, p);
538         rb_insert_color(&orphan->rb, &c->orph_tree);
539         list_add_tail(&orphan->list, &c->orph_list);
540         orphan->del = 1;
541         orphan->dnext = c->orph_dnext;
542         c->orph_dnext = orphan;
543         dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
544                 c->new_orphans, c->tot_orphans);
545         return 0;
546 }
547 
548 /**
549  * do_kill_orphans - remove orphan inodes from the index.
550  * @c: UBIFS file-system description object
551  * @sleb: scanned LEB
552  * @last_cmt_no: cmt_no of last orphan node read is passed and returned here
553  * @outofdate: whether the LEB is out of date is returned here
554  * @last_flagged: whether the end orphan node is encountered
555  *
556  * This function is a helper to the 'kill_orphans()' function. It goes through
557  * every orphan node in a LEB and for every inode number recorded, removes
558  * all keys for that inode from the TNC.
559  */
560 static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
561                            unsigned long long *last_cmt_no, int *outofdate,
562                            int *last_flagged)
563 {
564         struct ubifs_scan_node *snod;
565         struct ubifs_orph_node *orph;
566         unsigned long long cmt_no;
567         ino_t inum;
568         int i, n, err, first = 1;
569 
570         list_for_each_entry(snod, &sleb->nodes, list) {
571                 if (snod->type != UBIFS_ORPH_NODE) {
572                         ubifs_err(c, "invalid node type %d in orphan area at %d:%d",
573                                   snod->type, sleb->lnum, snod->offs);
574                         ubifs_dump_node(c, snod->node);
575                         return -EINVAL;
576                 }
577 
578                 orph = snod->node;
579 
580                 /* Check commit number */
581                 cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
582                 /*
583                  * The commit number on the master node may be less, because
584                  * of a failed commit. If there are several failed commits in a
585                  * row, the commit number written on orphan nodes will continue
586                  * to increase (because the commit number is adjusted here) even
587                  * though the commit number on the master node stays the same
588                  * because the master node has not been re-written.
589                  */
590                 if (cmt_no > c->cmt_no)
591                         c->cmt_no = cmt_no;
592                 if (cmt_no < *last_cmt_no && *last_flagged) {
593                         /*
594                          * The last orphan node had a higher commit number and
595                          * was flagged as the last written for that commit
596                          * number. That makes this orphan node, out of date.
597                          */
598                         if (!first) {
599                                 ubifs_err(c, "out of order commit number %llu in orphan node at %d:%d",
600                                           cmt_no, sleb->lnum, snod->offs);
601                                 ubifs_dump_node(c, snod->node);
602                                 return -EINVAL;
603                         }
604                         dbg_rcvry("out of date LEB %d", sleb->lnum);
605                         *outofdate = 1;
606                         return 0;
607                 }
608 
609                 if (first)
610                         first = 0;
611 
612                 n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
613                 for (i = 0; i < n; i++) {
614                         inum = le64_to_cpu(orph->inos[i]);
615                         dbg_rcvry("deleting orphaned inode %lu",
616                                   (unsigned long)inum);
617                         err = ubifs_tnc_remove_ino(c, inum);
618                         if (err)
619                                 return err;
620                         err = insert_dead_orphan(c, inum);
621                         if (err)
622                                 return err;
623                 }
624 
625                 *last_cmt_no = cmt_no;
626                 if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
627                         dbg_rcvry("last orph node for commit %llu at %d:%d",
628                                   cmt_no, sleb->lnum, snod->offs);
629                         *last_flagged = 1;
630                 } else
631                         *last_flagged = 0;
632         }
633 
634         return 0;
635 }
636 
637 /**
638  * kill_orphans - remove all orphan inodes from the index.
639  * @c: UBIFS file-system description object
640  *
641  * If recovery is required, then orphan inodes recorded during the previous
642  * session (which ended with an unclean unmount) must be deleted from the index.
643  * This is done by updating the TNC, but since the index is not updated until
644  * the next commit, the LEBs where the orphan information is recorded are not
645  * erased until the next commit.
646  */
647 static int kill_orphans(struct ubifs_info *c)
648 {
649         unsigned long long last_cmt_no = 0;
650         int lnum, err = 0, outofdate = 0, last_flagged = 0;
651 
652         c->ohead_lnum = c->orph_first;
653         c->ohead_offs = 0;
654         /* Check no-orphans flag and skip this if no orphans */
655         if (c->no_orphs) {
656                 dbg_rcvry("no orphans");
657                 return 0;
658         }
659         /*
660          * Orph nodes always start at c->orph_first and are written to each
661          * successive LEB in turn. Generally unused LEBs will have been unmapped
662          * but may contain out of date orphan nodes if the unmap didn't go
663          * through. In addition, the last orphan node written for each commit is
664          * marked (top bit of orph->cmt_no is set to 1). It is possible that
665          * there are orphan nodes from the next commit (i.e. the commit did not
666          * complete successfully). In that case, no orphans will have been lost
667          * due to the way that orphans are written, and any orphans added will
668          * be valid orphans anyway and so can be deleted.
669          */
670         for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
671                 struct ubifs_scan_leb *sleb;
672 
673                 dbg_rcvry("LEB %d", lnum);
674                 sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
675                 if (IS_ERR(sleb)) {
676                         if (PTR_ERR(sleb) == -EUCLEAN)
677                                 sleb = ubifs_recover_leb(c, lnum, 0,
678                                                          c->sbuf, -1);
679                         if (IS_ERR(sleb)) {
680                                 err = PTR_ERR(sleb);
681                                 break;
682                         }
683                 }
684                 err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
685                                       &last_flagged);
686                 if (err || outofdate) {
687                         ubifs_scan_destroy(sleb);
688                         break;
689                 }
690                 if (sleb->endpt) {
691                         c->ohead_lnum = lnum;
692                         c->ohead_offs = sleb->endpt;
693                 }
694                 ubifs_scan_destroy(sleb);
695         }
696         return err;
697 }
698 
699 /**
700  * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
701  * @c: UBIFS file-system description object
702  * @unclean: indicates recovery from unclean unmount
703  * @read_only: indicates read only mount
704  *
705  * This function is called when mounting to erase orphans from the previous
706  * session. If UBIFS was not unmounted cleanly, then the inodes recorded as
707  * orphans are deleted.
708  */
709 int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
710 {
711         int err = 0;
712 
713         c->max_orphans = tot_avail_orphs(c);
714 
715         if (!read_only) {
716                 c->orph_buf = vmalloc(c->leb_size);
717                 if (!c->orph_buf)
718                         return -ENOMEM;
719         }
720 
721         if (unclean)
722                 err = kill_orphans(c);
723         else if (!read_only)
724                 err = ubifs_clear_orphans(c);
725 
726         return err;
727 }
728 
729 /*
730  * Everything below is related to debugging.
731  */
732 
733 struct check_orphan {
734         struct rb_node rb;
735         ino_t inum;
736 };
737 
738 struct check_info {
739         unsigned long last_ino;
740         unsigned long tot_inos;
741         unsigned long missing;
742         unsigned long long leaf_cnt;
743         struct ubifs_ino_node *node;
744         struct rb_root root;
745 };
746 
747 static int dbg_find_orphan(struct ubifs_info *c, ino_t inum)
748 {
749         struct ubifs_orphan *o;
750         struct rb_node *p;
751 
752         spin_lock(&c->orphan_lock);
753         p = c->orph_tree.rb_node;
754         while (p) {
755                 o = rb_entry(p, struct ubifs_orphan, rb);
756                 if (inum < o->inum)
757                         p = p->rb_left;
758                 else if (inum > o->inum)
759                         p = p->rb_right;
760                 else {
761                         spin_unlock(&c->orphan_lock);
762                         return 1;
763                 }
764         }
765         spin_unlock(&c->orphan_lock);
766         return 0;
767 }
768 
769 static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
770 {
771         struct check_orphan *orphan, *o;
772         struct rb_node **p, *parent = NULL;
773 
774         orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
775         if (!orphan)
776                 return -ENOMEM;
777         orphan->inum = inum;
778 
779         p = &root->rb_node;
780         while (*p) {
781                 parent = *p;
782                 o = rb_entry(parent, struct check_orphan, rb);
783                 if (inum < o->inum)
784                         p = &(*p)->rb_left;
785                 else if (inum > o->inum)
786                         p = &(*p)->rb_right;
787                 else {
788                         kfree(orphan);
789                         return 0;
790                 }
791         }
792         rb_link_node(&orphan->rb, parent, p);
793         rb_insert_color(&orphan->rb, root);
794         return 0;
795 }
796 
797 static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
798 {
799         struct check_orphan *o;
800         struct rb_node *p;
801 
802         p = root->rb_node;
803         while (p) {
804                 o = rb_entry(p, struct check_orphan, rb);
805                 if (inum < o->inum)
806                         p = p->rb_left;
807                 else if (inum > o->inum)
808                         p = p->rb_right;
809                 else
810                         return 1;
811         }
812         return 0;
813 }
814 
815 static void dbg_free_check_tree(struct rb_root *root)
816 {
817         struct check_orphan *o, *n;
818 
819         rbtree_postorder_for_each_entry_safe(o, n, root, rb)
820                 kfree(o);
821 }
822 
823 static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
824                             void *priv)
825 {
826         struct check_info *ci = priv;
827         ino_t inum;
828         int err;
829 
830         inum = key_inum(c, &zbr->key);
831         if (inum != ci->last_ino) {
832                 /* Lowest node type is the inode node, so it comes first */
833                 if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
834                         ubifs_err(c, "found orphan node ino %lu, type %d",
835                                   (unsigned long)inum, key_type(c, &zbr->key));
836                 ci->last_ino = inum;
837                 ci->tot_inos += 1;
838                 err = ubifs_tnc_read_node(c, zbr, ci->node);
839                 if (err) {
840                         ubifs_err(c, "node read failed, error %d", err);
841                         return err;
842                 }
843                 if (ci->node->nlink == 0)
844                         /* Must be recorded as an orphan */
845                         if (!dbg_find_check_orphan(&ci->root, inum) &&
846                             !dbg_find_orphan(c, inum)) {
847                                 ubifs_err(c, "missing orphan, ino %lu",
848                                           (unsigned long)inum);
849                                 ci->missing += 1;
850                         }
851         }
852         ci->leaf_cnt += 1;
853         return 0;
854 }
855 
856 static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
857 {
858         struct ubifs_scan_node *snod;
859         struct ubifs_orph_node *orph;
860         ino_t inum;
861         int i, n, err;
862 
863         list_for_each_entry(snod, &sleb->nodes, list) {
864                 cond_resched();
865                 if (snod->type != UBIFS_ORPH_NODE)
866                         continue;
867                 orph = snod->node;
868                 n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
869                 for (i = 0; i < n; i++) {
870                         inum = le64_to_cpu(orph->inos[i]);
871                         err = dbg_ins_check_orphan(&ci->root, inum);
872                         if (err)
873                                 return err;
874                 }
875         }
876         return 0;
877 }
878 
879 static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
880 {
881         int lnum, err = 0;
882         void *buf;
883 
884         /* Check no-orphans flag and skip this if no orphans */
885         if (c->no_orphs)
886                 return 0;
887 
888         buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
889         if (!buf) {
890                 ubifs_err(c, "cannot allocate memory to check orphans");
891                 return 0;
892         }
893 
894         for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
895                 struct ubifs_scan_leb *sleb;
896 
897                 sleb = ubifs_scan(c, lnum, 0, buf, 0);
898                 if (IS_ERR(sleb)) {
899                         err = PTR_ERR(sleb);
900                         break;
901                 }
902 
903                 err = dbg_read_orphans(ci, sleb);
904                 ubifs_scan_destroy(sleb);
905                 if (err)
906                         break;
907         }
908 
909         vfree(buf);
910         return err;
911 }
912 
913 static int dbg_check_orphans(struct ubifs_info *c)
914 {
915         struct check_info ci;
916         int err;
917 
918         if (!dbg_is_chk_orph(c))
919                 return 0;
920 
921         ci.last_ino = 0;
922         ci.tot_inos = 0;
923         ci.missing  = 0;
924         ci.leaf_cnt = 0;
925         ci.root = RB_ROOT;
926         ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
927         if (!ci.node) {
928                 ubifs_err(c, "out of memory");
929                 return -ENOMEM;
930         }
931 
932         err = dbg_scan_orphans(c, &ci);
933         if (err)
934                 goto out;
935 
936         err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
937         if (err) {
938                 ubifs_err(c, "cannot scan TNC, error %d", err);
939                 goto out;
940         }
941 
942         if (ci.missing) {
943                 ubifs_err(c, "%lu missing orphan(s)", ci.missing);
944                 err = -EINVAL;
945                 goto out;
946         }
947 
948         dbg_cmt("last inode number is %lu", ci.last_ino);
949         dbg_cmt("total number of inodes is %lu", ci.tot_inos);
950         dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
951 
952 out:
953         dbg_free_check_tree(&ci.root);
954         kfree(ci.node);
955         return err;
956 }
957 

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