fs/ubifs/orphan.c

   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 }