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
  55static 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 */
  65int 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("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 */
 115void 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("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 */
 168int 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 */
 202static 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 */
 222static 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 */
 242static 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 */
 273static 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("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 */
 336static 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                lnum = c->ohead_lnum + 1;
 350                for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
 351                        err = ubifs_leb_unmap(c, lnum);
 352                        if (err)
 353                                return err;
 354                }
 355        }
 356        return 0;
 357}
 358
 359/**
 360 * consolidate - consolidate the orphan area.
 361 * @c: UBIFS file-system description object
 362 *
 363 * This function enables consolidation by putting all the orphans into the list
 364 * to commit. The list is in the order that the orphans were added, and the
 365 * LEBs are written atomically in order, so at no time can orphans be lost by
 366 * an unclean unmount.
 367 *
 368 * This function returns %0 on success and a negative error code on failure.
 369 */
 370static int consolidate(struct ubifs_info *c)
 371{
 372        int tot_avail = tot_avail_orphs(c), err = 0;
 373
 374        spin_lock(&c->orphan_lock);
 375        dbg_cmt("there is space for %d orphans and there are %d",
 376                tot_avail, c->tot_orphans);
 377        if (c->tot_orphans - c->new_orphans <= tot_avail) {
 378                struct ubifs_orphan *orphan, **last;
 379                int cnt = 0;
 380
 381                /* Change the cnext list to include all non-new orphans */
 382                last = &c->orph_cnext;
 383                list_for_each_entry(orphan, &c->orph_list, list) {
 384                        if (orphan->new)
 385                                continue;
 386                        orphan->cmt = 1;
 387                        *last = orphan;
 388                        last = &orphan->cnext;
 389                        cnt += 1;
 390                }
 391                *last = NULL;
 392                ubifs_assert(cnt == c->tot_orphans - c->new_orphans);
 393                c->cmt_orphans = cnt;
 394                c->ohead_lnum = c->orph_first;
 395                c->ohead_offs = 0;
 396        } else {
 397                /*
 398                 * We limit the number of orphans so that this should
 399                 * never happen.
 400                 */
 401                ubifs_err("out of space in orphan area");
 402                err = -EINVAL;
 403        }
 404        spin_unlock(&c->orphan_lock);
 405        return err;
 406}
 407
 408/**
 409 * commit_orphans - commit orphans.
 410 * @c: UBIFS file-system description object
 411 *
 412 * This function commits orphans to flash. On success, %0 is returned,
 413 * otherwise a negative error code is returned.
 414 */
 415static int commit_orphans(struct ubifs_info *c)
 416{
 417        int avail, atomic = 0, err;
 418
 419        ubifs_assert(c->cmt_orphans > 0);
 420        avail = avail_orphs(c);
 421        if (avail < c->cmt_orphans) {
 422                /* Not enough space to write new orphans, so consolidate */
 423                err = consolidate(c);
 424                if (err)
 425                        return err;
 426                atomic = 1;
 427        }
 428        err = write_orph_nodes(c, atomic);
 429        return err;
 430}
 431
 432/**
 433 * erase_deleted - erase the orphans marked for deletion.
 434 * @c: UBIFS file-system description object
 435 *
 436 * During commit, the orphans being committed cannot be deleted, so they are
 437 * marked for deletion and deleted by this function. Also, the recovery
 438 * adds killed orphans to the deletion list, and therefore they are deleted
 439 * here too.
 440 */
 441static void erase_deleted(struct ubifs_info *c)
 442{
 443        struct ubifs_orphan *orphan, *dnext;
 444
 445        spin_lock(&c->orphan_lock);
 446        dnext = c->orph_dnext;
 447        while (dnext) {
 448                orphan = dnext;
 449                dnext = orphan->dnext;
 450                ubifs_assert(!orphan->new);
 451                ubifs_assert(orphan->del);
 452                rb_erase(&orphan->rb, &c->orph_tree);
 453                list_del(&orphan->list);
 454                c->tot_orphans -= 1;
 455                dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum);
 456                kfree(orphan);
 457        }
 458        c->orph_dnext = NULL;
 459        spin_unlock(&c->orphan_lock);
 460}
 461
 462/**
 463 * ubifs_orphan_end_commit - end commit of orphans.
 464 * @c: UBIFS file-system description object
 465 *
 466 * End commit of orphans.
 467 */
 468int ubifs_orphan_end_commit(struct ubifs_info *c)
 469{
 470        int err;
 471
 472        if (c->cmt_orphans != 0) {
 473                err = commit_orphans(c);
 474                if (err)
 475                        return err;
 476        }
 477        erase_deleted(c);
 478        err = dbg_check_orphans(c);
 479        return err;
 480}
 481
 482/**
 483 * ubifs_clear_orphans - erase all LEBs used for orphans.
 484 * @c: UBIFS file-system description object
 485 *
 486 * If recovery is not required, then the orphans from the previous session
 487 * are not needed. This function locates the LEBs used to record
 488 * orphans, and un-maps them.
 489 */
 490int ubifs_clear_orphans(struct ubifs_info *c)
 491{
 492        int lnum, err;
 493
 494        for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
 495                err = ubifs_leb_unmap(c, lnum);
 496                if (err)
 497                        return err;
 498        }
 499        c->ohead_lnum = c->orph_first;
 500        c->ohead_offs = 0;
 501        return 0;
 502}
 503
 504/**
 505 * insert_dead_orphan - insert an orphan.
 506 * @c: UBIFS file-system description object
 507 * @inum: orphan inode number
 508 *
 509 * This function is a helper to the 'do_kill_orphans()' function. The orphan
 510 * must be kept until the next commit, so it is added to the rb-tree and the
 511 * deletion list.
 512 */
 513static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
 514{
 515        struct ubifs_orphan *orphan, *o;
 516        struct rb_node **p, *parent = NULL;
 517
 518        orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
 519        if (!orphan)
 520                return -ENOMEM;
 521        orphan->inum = inum;
 522
 523        p = &c->orph_tree.rb_node;
 524        while (*p) {
 525                parent = *p;
 526                o = rb_entry(parent, struct ubifs_orphan, rb);
 527                if (inum < o->inum)
 528                        p = &(*p)->rb_left;
 529                else if (inum > o->inum)
 530                        p = &(*p)->rb_right;
 531                else {
 532                        /* Already added - no problem */
 533                        kfree(orphan);
 534                        return 0;
 535                }
 536        }
 537        c->tot_orphans += 1;
 538        rb_link_node(&orphan->rb, parent, p);
 539        rb_insert_color(&orphan->rb, &c->orph_tree);
 540        list_add_tail(&orphan->list, &c->orph_list);
 541        orphan->del = 1;
 542        orphan->dnext = c->orph_dnext;
 543        c->orph_dnext = orphan;
 544        dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
 545                c->new_orphans, c->tot_orphans);
 546        return 0;
 547}
 548
 549/**
 550 * do_kill_orphans - remove orphan inodes from the index.
 551 * @c: UBIFS file-system description object
 552 * @sleb: scanned LEB
 553 * @last_cmt_no: cmt_no of last orphan node read is passed and returned here
 554 * @outofdate: whether the LEB is out of date is returned here
 555 * @last_flagged: whether the end orphan node is encountered
 556 *
 557 * This function is a helper to the 'kill_orphans()' function. It goes through
 558 * every orphan node in a LEB and for every inode number recorded, removes
 559 * all keys for that inode from the TNC.
 560 */
 561static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 562                           unsigned long long *last_cmt_no, int *outofdate,
 563                           int *last_flagged)
 564{
 565        struct ubifs_scan_node *snod;
 566        struct ubifs_orph_node *orph;
 567        unsigned long long cmt_no;
 568        ino_t inum;
 569        int i, n, err, first = 1;
 570
 571        list_for_each_entry(snod, &sleb->nodes, list) {
 572                if (snod->type != UBIFS_ORPH_NODE) {
 573                        ubifs_err("invalid node type %d in orphan area at %d:%d",
 574                                  snod->type, sleb->lnum, snod->offs);
 575                        ubifs_dump_node(c, snod->node);
 576                        return -EINVAL;
 577                }
 578
 579                orph = snod->node;
 580
 581                /* Check commit number */
 582                cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
 583                /*
 584                 * The commit number on the master node may be less, because
 585                 * of a failed commit. If there are several failed commits in a
 586                 * row, the commit number written on orphan nodes will continue
 587                 * to increase (because the commit number is adjusted here) even
 588                 * though the commit number on the master node stays the same
 589                 * because the master node has not been re-written.
 590                 */
 591                if (cmt_no > c->cmt_no)
 592                        c->cmt_no = cmt_no;
 593                if (cmt_no < *last_cmt_no && *last_flagged) {
 594                        /*
 595                         * The last orphan node had a higher commit number and
 596                         * was flagged as the last written for that commit
 597                         * number. That makes this orphan node, out of date.
 598                         */
 599                        if (!first) {
 600                                ubifs_err("out of order commit number %llu in orphan node at %d:%d",
 601                                          cmt_no, sleb->lnum, snod->offs);
 602                                ubifs_dump_node(c, snod->node);
 603                                return -EINVAL;
 604                        }
 605                        dbg_rcvry("out of date LEB %d", sleb->lnum);
 606                        *outofdate = 1;
 607                        return 0;
 608                }
 609
 610                if (first)
 611                        first = 0;
 612
 613                n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
 614                for (i = 0; i < n; i++) {
 615                        inum = le64_to_cpu(orph->inos[i]);
 616                        dbg_rcvry("deleting orphaned inode %lu",
 617                                  (unsigned long)inum);
 618                        err = ubifs_tnc_remove_ino(c, inum);
 619                        if (err)
 620                                return err;
 621                        err = insert_dead_orphan(c, inum);
 622                        if (err)
 623                                return err;
 624                }
 625
 626                *last_cmt_no = cmt_no;
 627                if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
 628                        dbg_rcvry("last orph node for commit %llu at %d:%d",
 629                                  cmt_no, sleb->lnum, snod->offs);
 630                        *last_flagged = 1;
 631                } else
 632                        *last_flagged = 0;
 633        }
 634
 635        return 0;
 636}
 637
 638/**
 639 * kill_orphans - remove all orphan inodes from the index.
 640 * @c: UBIFS file-system description object
 641 *
 642 * If recovery is required, then orphan inodes recorded during the previous
 643 * session (which ended with an unclean unmount) must be deleted from the index.
 644 * This is done by updating the TNC, but since the index is not updated until
 645 * the next commit, the LEBs where the orphan information is recorded are not
 646 * erased until the next commit.
 647 */
 648static int kill_orphans(struct ubifs_info *c)
 649{
 650        unsigned long long last_cmt_no = 0;
 651        int lnum, err = 0, outofdate = 0, last_flagged = 0;
 652
 653        c->ohead_lnum = c->orph_first;
 654        c->ohead_offs = 0;
 655        /* Check no-orphans flag and skip this if no orphans */
 656        if (c->no_orphs) {
 657                dbg_rcvry("no orphans");
 658                return 0;
 659        }
 660        /*
 661         * Orph nodes always start at c->orph_first and are written to each
 662         * successive LEB in turn. Generally unused LEBs will have been unmapped
 663         * but may contain out of date orphan nodes if the unmap didn't go
 664         * through. In addition, the last orphan node written for each commit is
 665         * marked (top bit of orph->cmt_no is set to 1). It is possible that
 666         * there are orphan nodes from the next commit (i.e. the commit did not
 667         * complete successfully). In that case, no orphans will have been lost
 668         * due to the way that orphans are written, and any orphans added will
 669         * be valid orphans anyway and so can be deleted.
 670         */
 671        for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
 672                struct ubifs_scan_leb *sleb;
 673
 674                dbg_rcvry("LEB %d", lnum);
 675                sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
 676                if (IS_ERR(sleb)) {
 677                        if (PTR_ERR(sleb) == -EUCLEAN)
 678                                sleb = ubifs_recover_leb(c, lnum, 0,
 679                                                         c->sbuf, -1);
 680                        if (IS_ERR(sleb)) {
 681                                err = PTR_ERR(sleb);
 682                                break;
 683                        }
 684                }
 685                err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
 686                                      &last_flagged);
 687                if (err || outofdate) {
 688                        ubifs_scan_destroy(sleb);
 689                        break;
 690                }
 691                if (sleb->endpt) {
 692                        c->ohead_lnum = lnum;
 693                        c->ohead_offs = sleb->endpt;
 694                }
 695                ubifs_scan_destroy(sleb);
 696        }
 697        return err;
 698}
 699
 700/**
 701 * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
 702 * @c: UBIFS file-system description object
 703 * @unclean: indicates recovery from unclean unmount
 704 * @read_only: indicates read only mount
 705 *
 706 * This function is called when mounting to erase orphans from the previous
 707 * session. If UBIFS was not unmounted cleanly, then the inodes recorded as
 708 * orphans are deleted.
 709 */
 710int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
 711{
 712        int err = 0;
 713
 714        c->max_orphans = tot_avail_orphs(c);
 715
 716        if (!read_only) {
 717                c->orph_buf = vmalloc(c->leb_size);
 718                if (!c->orph_buf)
 719                        return -ENOMEM;
 720        }
 721
 722        if (unclean)
 723                err = kill_orphans(c);
 724        else if (!read_only)
 725                err = ubifs_clear_orphans(c);
 726
 727        return err;
 728}
 729
 730/*
 731 * Everything below is related to debugging.
 732 */
 733
 734struct check_orphan {
 735        struct rb_node rb;
 736        ino_t inum;
 737};
 738
 739struct check_info {
 740        unsigned long last_ino;
 741        unsigned long tot_inos;
 742        unsigned long missing;
 743        unsigned long long leaf_cnt;
 744        struct ubifs_ino_node *node;
 745        struct rb_root root;
 746};
 747
 748static int dbg_find_orphan(struct ubifs_info *c, ino_t inum)
 749{
 750        struct ubifs_orphan *o;
 751        struct rb_node *p;
 752
 753        spin_lock(&c->orphan_lock);
 754        p = c->orph_tree.rb_node;
 755        while (p) {
 756                o = rb_entry(p, struct ubifs_orphan, rb);
 757                if (inum < o->inum)
 758                        p = p->rb_left;
 759                else if (inum > o->inum)
 760                        p = p->rb_right;
 761                else {
 762                        spin_unlock(&c->orphan_lock);
 763                        return 1;
 764                }
 765        }
 766        spin_unlock(&c->orphan_lock);
 767        return 0;
 768}
 769
 770static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
 771{
 772        struct check_orphan *orphan, *o;
 773        struct rb_node **p, *parent = NULL;
 774
 775        orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
 776        if (!orphan)
 777                return -ENOMEM;
 778        orphan->inum = inum;
 779
 780        p = &root->rb_node;
 781        while (*p) {
 782                parent = *p;
 783                o = rb_entry(parent, struct check_orphan, rb);
 784                if (inum < o->inum)
 785                        p = &(*p)->rb_left;
 786                else if (inum > o->inum)
 787                        p = &(*p)->rb_right;
 788                else {
 789                        kfree(orphan);
 790                        return 0;
 791                }
 792        }
 793        rb_link_node(&orphan->rb, parent, p);
 794        rb_insert_color(&orphan->rb, root);
 795        return 0;
 796}
 797
 798static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
 799{
 800        struct check_orphan *o;
 801        struct rb_node *p;
 802
 803        p = root->rb_node;
 804        while (p) {
 805                o = rb_entry(p, struct check_orphan, rb);
 806                if (inum < o->inum)
 807                        p = p->rb_left;
 808                else if (inum > o->inum)
 809                        p = p->rb_right;
 810                else
 811                        return 1;
 812        }
 813        return 0;
 814}
 815
 816static void dbg_free_check_tree(struct rb_root *root)
 817{
 818        struct rb_node *this = root->rb_node;
 819        struct check_orphan *o;
 820
 821        while (this) {
 822                if (this->rb_left) {
 823                        this = this->rb_left;
 824                        continue;
 825                } else if (this->rb_right) {
 826                        this = this->rb_right;
 827                        continue;
 828                }
 829                o = rb_entry(this, struct check_orphan, rb);
 830                this = rb_parent(this);
 831                if (this) {
 832                        if (this->rb_left == &o->rb)
 833                                this->rb_left = NULL;
 834                        else
 835                                this->rb_right = NULL;
 836                }
 837                kfree(o);
 838        }
 839}
 840
 841static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
 842                            void *priv)
 843{
 844        struct check_info *ci = priv;
 845        ino_t inum;
 846        int err;
 847
 848        inum = key_inum(c, &zbr->key);
 849        if (inum != ci->last_ino) {
 850                /* Lowest node type is the inode node, so it comes first */
 851                if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
 852                        ubifs_err("found orphan node ino %lu, type %d",
 853                                  (unsigned long)inum, key_type(c, &zbr->key));
 854                ci->last_ino = inum;
 855                ci->tot_inos += 1;
 856                err = ubifs_tnc_read_node(c, zbr, ci->node);
 857                if (err) {
 858                        ubifs_err("node read failed, error %d", err);
 859                        return err;
 860                }
 861                if (ci->node->nlink == 0)
 862                        /* Must be recorded as an orphan */
 863                        if (!dbg_find_check_orphan(&ci->root, inum) &&
 864                            !dbg_find_orphan(c, inum)) {
 865                                ubifs_err("missing orphan, ino %lu",
 866                                          (unsigned long)inum);
 867                                ci->missing += 1;
 868                        }
 869        }
 870        ci->leaf_cnt += 1;
 871        return 0;
 872}
 873
 874static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
 875{
 876        struct ubifs_scan_node *snod;
 877        struct ubifs_orph_node *orph;
 878        ino_t inum;
 879        int i, n, err;
 880
 881        list_for_each_entry(snod, &sleb->nodes, list) {
 882                cond_resched();
 883                if (snod->type != UBIFS_ORPH_NODE)
 884                        continue;
 885                orph = snod->node;
 886                n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
 887                for (i = 0; i < n; i++) {
 888                        inum = le64_to_cpu(orph->inos[i]);
 889                        err = dbg_ins_check_orphan(&ci->root, inum);
 890                        if (err)
 891                                return err;
 892                }
 893        }
 894        return 0;
 895}
 896
 897static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
 898{
 899        int lnum, err = 0;
 900        void *buf;
 901
 902        /* Check no-orphans flag and skip this if no orphans */
 903        if (c->no_orphs)
 904                return 0;
 905
 906        buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
 907        if (!buf) {
 908                ubifs_err("cannot allocate memory to check orphans");
 909                return 0;
 910        }
 911
 912        for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
 913                struct ubifs_scan_leb *sleb;
 914
 915                sleb = ubifs_scan(c, lnum, 0, buf, 0);
 916                if (IS_ERR(sleb)) {
 917                        err = PTR_ERR(sleb);
 918                        break;
 919                }
 920
 921                err = dbg_read_orphans(ci, sleb);
 922                ubifs_scan_destroy(sleb);
 923                if (err)
 924                        break;
 925        }
 926
 927        vfree(buf);
 928        return err;
 929}
 930
 931static int dbg_check_orphans(struct ubifs_info *c)
 932{
 933        struct check_info ci;
 934        int err;
 935
 936        if (!dbg_is_chk_orph(c))
 937                return 0;
 938
 939        ci.last_ino = 0;
 940        ci.tot_inos = 0;
 941        ci.missing  = 0;
 942        ci.leaf_cnt = 0;
 943        ci.root = RB_ROOT;
 944        ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
 945        if (!ci.node) {
 946                ubifs_err("out of memory");
 947                return -ENOMEM;
 948        }
 949
 950        err = dbg_scan_orphans(c, &ci);
 951        if (err)
 952                goto out;
 953
 954        err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
 955        if (err) {
 956                ubifs_err("cannot scan TNC, error %d", err);
 957                goto out;
 958        }
 959
 960        if (ci.missing) {
 961                ubifs_err("%lu missing orphan(s)", ci.missing);
 962                err = -EINVAL;
 963                goto out;
 964        }
 965
 966        dbg_cmt("last inode number is %lu", ci.last_ino);
 967        dbg_cmt("total number of inodes is %lu", ci.tot_inos);
 968        dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
 969
 970out:
 971        dbg_free_check_tree(&ci.root);
 972        kfree(ci.node);
 973        return err;
 974}
 975
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