linux/fs/ext3/ialloc.c
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   1/*
   2 *  linux/fs/ext3/ialloc.c
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  BSD ufs-inspired inode and directory allocation by
  10 *  Stephen Tweedie (sct@redhat.com), 1993
  11 *  Big-endian to little-endian byte-swapping/bitmaps by
  12 *        David S. Miller (davem@caip.rutgers.edu), 1995
  13 */
  14
  15#include <linux/time.h>
  16#include <linux/fs.h>
  17#include <linux/jbd.h>
  18#include <linux/ext3_fs.h>
  19#include <linux/ext3_jbd.h>
  20#include <linux/stat.h>
  21#include <linux/string.h>
  22#include <linux/quotaops.h>
  23#include <linux/buffer_head.h>
  24#include <linux/random.h>
  25#include <linux/bitops.h>
  26
  27#include <asm/byteorder.h>
  28
  29#include "xattr.h"
  30#include "acl.h"
  31
  32/*
  33 * ialloc.c contains the inodes allocation and deallocation routines
  34 */
  35
  36/*
  37 * The free inodes are managed by bitmaps.  A file system contains several
  38 * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  39 * block for inodes, N blocks for the inode table and data blocks.
  40 *
  41 * The file system contains group descriptors which are located after the
  42 * super block.  Each descriptor contains the number of the bitmap block and
  43 * the free blocks count in the block.
  44 */
  45
  46
  47/*
  48 * Read the inode allocation bitmap for a given block_group, reading
  49 * into the specified slot in the superblock's bitmap cache.
  50 *
  51 * Return buffer_head of bitmap on success or NULL.
  52 */
  53static struct buffer_head *
  54read_inode_bitmap(struct super_block * sb, unsigned long block_group)
  55{
  56        struct ext3_group_desc *desc;
  57        struct buffer_head *bh = NULL;
  58
  59        desc = ext3_get_group_desc(sb, block_group, NULL);
  60        if (!desc)
  61                goto error_out;
  62
  63        bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
  64        if (!bh)
  65                ext3_error(sb, "read_inode_bitmap",
  66                            "Cannot read inode bitmap - "
  67                            "block_group = %lu, inode_bitmap = %u",
  68                            block_group, le32_to_cpu(desc->bg_inode_bitmap));
  69error_out:
  70        return bh;
  71}
  72
  73/*
  74 * NOTE! When we get the inode, we're the only people
  75 * that have access to it, and as such there are no
  76 * race conditions we have to worry about. The inode
  77 * is not on the hash-lists, and it cannot be reached
  78 * through the filesystem because the directory entry
  79 * has been deleted earlier.
  80 *
  81 * HOWEVER: we must make sure that we get no aliases,
  82 * which means that we have to call "clear_inode()"
  83 * _before_ we mark the inode not in use in the inode
  84 * bitmaps. Otherwise a newly created file might use
  85 * the same inode number (not actually the same pointer
  86 * though), and then we'd have two inodes sharing the
  87 * same inode number and space on the harddisk.
  88 */
  89void ext3_free_inode (handle_t *handle, struct inode * inode)
  90{
  91        struct super_block * sb = inode->i_sb;
  92        int is_directory;
  93        unsigned long ino;
  94        struct buffer_head *bitmap_bh = NULL;
  95        struct buffer_head *bh2;
  96        unsigned long block_group;
  97        unsigned long bit;
  98        struct ext3_group_desc * gdp;
  99        struct ext3_super_block * es;
 100        struct ext3_sb_info *sbi;
 101        int fatal = 0, err;
 102
 103        if (atomic_read(&inode->i_count) > 1) {
 104                printk ("ext3_free_inode: inode has count=%d\n",
 105                                        atomic_read(&inode->i_count));
 106                return;
 107        }
 108        if (inode->i_nlink) {
 109                printk ("ext3_free_inode: inode has nlink=%d\n",
 110                        inode->i_nlink);
 111                return;
 112        }
 113        if (!sb) {
 114                printk("ext3_free_inode: inode on nonexistent device\n");
 115                return;
 116        }
 117        sbi = EXT3_SB(sb);
 118
 119        ino = inode->i_ino;
 120        ext3_debug ("freeing inode %lu\n", ino);
 121
 122        /*
 123         * Note: we must free any quota before locking the superblock,
 124         * as writing the quota to disk may need the lock as well.
 125         */
 126        vfs_dq_init(inode);
 127        ext3_xattr_delete_inode(handle, inode);
 128        vfs_dq_free_inode(inode);
 129        vfs_dq_drop(inode);
 130
 131        is_directory = S_ISDIR(inode->i_mode);
 132
 133        /* Do this BEFORE marking the inode not in use or returning an error */
 134        clear_inode (inode);
 135
 136        es = EXT3_SB(sb)->s_es;
 137        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 138                ext3_error (sb, "ext3_free_inode",
 139                            "reserved or nonexistent inode %lu", ino);
 140                goto error_return;
 141        }
 142        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 143        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 144        bitmap_bh = read_inode_bitmap(sb, block_group);
 145        if (!bitmap_bh)
 146                goto error_return;
 147
 148        BUFFER_TRACE(bitmap_bh, "get_write_access");
 149        fatal = ext3_journal_get_write_access(handle, bitmap_bh);
 150        if (fatal)
 151                goto error_return;
 152
 153        /* Ok, now we can actually update the inode bitmaps.. */
 154        if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 155                                        bit, bitmap_bh->b_data))
 156                ext3_error (sb, "ext3_free_inode",
 157                              "bit already cleared for inode %lu", ino);
 158        else {
 159                gdp = ext3_get_group_desc (sb, block_group, &bh2);
 160
 161                BUFFER_TRACE(bh2, "get_write_access");
 162                fatal = ext3_journal_get_write_access(handle, bh2);
 163                if (fatal) goto error_return;
 164
 165                if (gdp) {
 166                        spin_lock(sb_bgl_lock(sbi, block_group));
 167                        le16_add_cpu(&gdp->bg_free_inodes_count, 1);
 168                        if (is_directory)
 169                                le16_add_cpu(&gdp->bg_used_dirs_count, -1);
 170                        spin_unlock(sb_bgl_lock(sbi, block_group));
 171                        percpu_counter_inc(&sbi->s_freeinodes_counter);
 172                        if (is_directory)
 173                                percpu_counter_dec(&sbi->s_dirs_counter);
 174
 175                }
 176                BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 177                err = ext3_journal_dirty_metadata(handle, bh2);
 178                if (!fatal) fatal = err;
 179        }
 180        BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
 181        err = ext3_journal_dirty_metadata(handle, bitmap_bh);
 182        if (!fatal)
 183                fatal = err;
 184
 185error_return:
 186        brelse(bitmap_bh);
 187        ext3_std_error(sb, fatal);
 188}
 189
 190/*
 191 * There are two policies for allocating an inode.  If the new inode is
 192 * a directory, then a forward search is made for a block group with both
 193 * free space and a low directory-to-inode ratio; if that fails, then of
 194 * the groups with above-average free space, that group with the fewest
 195 * directories already is chosen.
 196 *
 197 * For other inodes, search forward from the parent directory\'s block
 198 * group to find a free inode.
 199 */
 200static int find_group_dir(struct super_block *sb, struct inode *parent)
 201{
 202        int ngroups = EXT3_SB(sb)->s_groups_count;
 203        unsigned int freei, avefreei;
 204        struct ext3_group_desc *desc, *best_desc = NULL;
 205        int group, best_group = -1;
 206
 207        freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
 208        avefreei = freei / ngroups;
 209
 210        for (group = 0; group < ngroups; group++) {
 211                desc = ext3_get_group_desc (sb, group, NULL);
 212                if (!desc || !desc->bg_free_inodes_count)
 213                        continue;
 214                if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 215                        continue;
 216                if (!best_desc ||
 217                    (le16_to_cpu(desc->bg_free_blocks_count) >
 218                     le16_to_cpu(best_desc->bg_free_blocks_count))) {
 219                        best_group = group;
 220                        best_desc = desc;
 221                }
 222        }
 223        return best_group;
 224}
 225
 226/*
 227 * Orlov's allocator for directories.
 228 *
 229 * We always try to spread first-level directories.
 230 *
 231 * If there are blockgroups with both free inodes and free blocks counts
 232 * not worse than average we return one with smallest directory count.
 233 * Otherwise we simply return a random group.
 234 *
 235 * For the rest rules look so:
 236 *
 237 * It's OK to put directory into a group unless
 238 * it has too many directories already (max_dirs) or
 239 * it has too few free inodes left (min_inodes) or
 240 * it has too few free blocks left (min_blocks) or
 241 * it's already running too large debt (max_debt).
 242 * Parent's group is preferred, if it doesn't satisfy these
 243 * conditions we search cyclically through the rest. If none
 244 * of the groups look good we just look for a group with more
 245 * free inodes than average (starting at parent's group).
 246 *
 247 * Debt is incremented each time we allocate a directory and decremented
 248 * when we allocate an inode, within 0--255.
 249 */
 250
 251#define INODE_COST 64
 252#define BLOCK_COST 256
 253
 254static int find_group_orlov(struct super_block *sb, struct inode *parent)
 255{
 256        int parent_group = EXT3_I(parent)->i_block_group;
 257        struct ext3_sb_info *sbi = EXT3_SB(sb);
 258        struct ext3_super_block *es = sbi->s_es;
 259        int ngroups = sbi->s_groups_count;
 260        int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
 261        unsigned int freei, avefreei;
 262        ext3_fsblk_t freeb, avefreeb;
 263        ext3_fsblk_t blocks_per_dir;
 264        unsigned int ndirs;
 265        int max_debt, max_dirs, min_inodes;
 266        ext3_grpblk_t min_blocks;
 267        int group = -1, i;
 268        struct ext3_group_desc *desc;
 269
 270        freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 271        avefreei = freei / ngroups;
 272        freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 273        avefreeb = freeb / ngroups;
 274        ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 275
 276        if ((parent == sb->s_root->d_inode) ||
 277            (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
 278                int best_ndir = inodes_per_group;
 279                int best_group = -1;
 280
 281                get_random_bytes(&group, sizeof(group));
 282                parent_group = (unsigned)group % ngroups;
 283                for (i = 0; i < ngroups; i++) {
 284                        group = (parent_group + i) % ngroups;
 285                        desc = ext3_get_group_desc (sb, group, NULL);
 286                        if (!desc || !desc->bg_free_inodes_count)
 287                                continue;
 288                        if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 289                                continue;
 290                        if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 291                                continue;
 292                        if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 293                                continue;
 294                        best_group = group;
 295                        best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 296                }
 297                if (best_group >= 0)
 298                        return best_group;
 299                goto fallback;
 300        }
 301
 302        blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
 303
 304        max_dirs = ndirs / ngroups + inodes_per_group / 16;
 305        min_inodes = avefreei - inodes_per_group / 4;
 306        min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
 307
 308        max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, (ext3_fsblk_t)BLOCK_COST);
 309        if (max_debt * INODE_COST > inodes_per_group)
 310                max_debt = inodes_per_group / INODE_COST;
 311        if (max_debt > 255)
 312                max_debt = 255;
 313        if (max_debt == 0)
 314                max_debt = 1;
 315
 316        for (i = 0; i < ngroups; i++) {
 317                group = (parent_group + i) % ngroups;
 318                desc = ext3_get_group_desc (sb, group, NULL);
 319                if (!desc || !desc->bg_free_inodes_count)
 320                        continue;
 321                if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 322                        continue;
 323                if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 324                        continue;
 325                if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 326                        continue;
 327                return group;
 328        }
 329
 330fallback:
 331        for (i = 0; i < ngroups; i++) {
 332                group = (parent_group + i) % ngroups;
 333                desc = ext3_get_group_desc (sb, group, NULL);
 334                if (!desc || !desc->bg_free_inodes_count)
 335                        continue;
 336                if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 337                        return group;
 338        }
 339
 340        if (avefreei) {
 341                /*
 342                 * The free-inodes counter is approximate, and for really small
 343                 * filesystems the above test can fail to find any blockgroups
 344                 */
 345                avefreei = 0;
 346                goto fallback;
 347        }
 348
 349        return -1;
 350}
 351
 352static int find_group_other(struct super_block *sb, struct inode *parent)
 353{
 354        int parent_group = EXT3_I(parent)->i_block_group;
 355        int ngroups = EXT3_SB(sb)->s_groups_count;
 356        struct ext3_group_desc *desc;
 357        int group, i;
 358
 359        /*
 360         * Try to place the inode in its parent directory
 361         */
 362        group = parent_group;
 363        desc = ext3_get_group_desc (sb, group, NULL);
 364        if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 365                        le16_to_cpu(desc->bg_free_blocks_count))
 366                return group;
 367
 368        /*
 369         * We're going to place this inode in a different blockgroup from its
 370         * parent.  We want to cause files in a common directory to all land in
 371         * the same blockgroup.  But we want files which are in a different
 372         * directory which shares a blockgroup with our parent to land in a
 373         * different blockgroup.
 374         *
 375         * So add our directory's i_ino into the starting point for the hash.
 376         */
 377        group = (group + parent->i_ino) % ngroups;
 378
 379        /*
 380         * Use a quadratic hash to find a group with a free inode and some free
 381         * blocks.
 382         */
 383        for (i = 1; i < ngroups; i <<= 1) {
 384                group += i;
 385                if (group >= ngroups)
 386                        group -= ngroups;
 387                desc = ext3_get_group_desc (sb, group, NULL);
 388                if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 389                                le16_to_cpu(desc->bg_free_blocks_count))
 390                        return group;
 391        }
 392
 393        /*
 394         * That failed: try linear search for a free inode, even if that group
 395         * has no free blocks.
 396         */
 397        group = parent_group;
 398        for (i = 0; i < ngroups; i++) {
 399                if (++group >= ngroups)
 400                        group = 0;
 401                desc = ext3_get_group_desc (sb, group, NULL);
 402                if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 403                        return group;
 404        }
 405
 406        return -1;
 407}
 408
 409/*
 410 * There are two policies for allocating an inode.  If the new inode is
 411 * a directory, then a forward search is made for a block group with both
 412 * free space and a low directory-to-inode ratio; if that fails, then of
 413 * the groups with above-average free space, that group with the fewest
 414 * directories already is chosen.
 415 *
 416 * For other inodes, search forward from the parent directory's block
 417 * group to find a free inode.
 418 */
 419struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
 420{
 421        struct super_block *sb;
 422        struct buffer_head *bitmap_bh = NULL;
 423        struct buffer_head *bh2;
 424        int group;
 425        unsigned long ino = 0;
 426        struct inode * inode;
 427        struct ext3_group_desc * gdp = NULL;
 428        struct ext3_super_block * es;
 429        struct ext3_inode_info *ei;
 430        struct ext3_sb_info *sbi;
 431        int err = 0;
 432        struct inode *ret;
 433        int i;
 434
 435        /* Cannot create files in a deleted directory */
 436        if (!dir || !dir->i_nlink)
 437                return ERR_PTR(-EPERM);
 438
 439        sb = dir->i_sb;
 440        inode = new_inode(sb);
 441        if (!inode)
 442                return ERR_PTR(-ENOMEM);
 443        ei = EXT3_I(inode);
 444
 445        sbi = EXT3_SB(sb);
 446        es = sbi->s_es;
 447        if (S_ISDIR(mode)) {
 448                if (test_opt (sb, OLDALLOC))
 449                        group = find_group_dir(sb, dir);
 450                else
 451                        group = find_group_orlov(sb, dir);
 452        } else
 453                group = find_group_other(sb, dir);
 454
 455        err = -ENOSPC;
 456        if (group == -1)
 457                goto out;
 458
 459        for (i = 0; i < sbi->s_groups_count; i++) {
 460                err = -EIO;
 461
 462                gdp = ext3_get_group_desc(sb, group, &bh2);
 463                if (!gdp)
 464                        goto fail;
 465
 466                brelse(bitmap_bh);
 467                bitmap_bh = read_inode_bitmap(sb, group);
 468                if (!bitmap_bh)
 469                        goto fail;
 470
 471                ino = 0;
 472
 473repeat_in_this_group:
 474                ino = ext3_find_next_zero_bit((unsigned long *)
 475                                bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
 476                if (ino < EXT3_INODES_PER_GROUP(sb)) {
 477
 478                        BUFFER_TRACE(bitmap_bh, "get_write_access");
 479                        err = ext3_journal_get_write_access(handle, bitmap_bh);
 480                        if (err)
 481                                goto fail;
 482
 483                        if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
 484                                                ino, bitmap_bh->b_data)) {
 485                                /* we won it */
 486                                BUFFER_TRACE(bitmap_bh,
 487                                        "call ext3_journal_dirty_metadata");
 488                                err = ext3_journal_dirty_metadata(handle,
 489                                                                bitmap_bh);
 490                                if (err)
 491                                        goto fail;
 492                                goto got;
 493                        }
 494                        /* we lost it */
 495                        journal_release_buffer(handle, bitmap_bh);
 496
 497                        if (++ino < EXT3_INODES_PER_GROUP(sb))
 498                                goto repeat_in_this_group;
 499                }
 500
 501                /*
 502                 * This case is possible in concurrent environment.  It is very
 503                 * rare.  We cannot repeat the find_group_xxx() call because
 504                 * that will simply return the same blockgroup, because the
 505                 * group descriptor metadata has not yet been updated.
 506                 * So we just go onto the next blockgroup.
 507                 */
 508                if (++group == sbi->s_groups_count)
 509                        group = 0;
 510        }
 511        err = -ENOSPC;
 512        goto out;
 513
 514got:
 515        ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
 516        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 517                ext3_error (sb, "ext3_new_inode",
 518                            "reserved inode or inode > inodes count - "
 519                            "block_group = %d, inode=%lu", group, ino);
 520                err = -EIO;
 521                goto fail;
 522        }
 523
 524        BUFFER_TRACE(bh2, "get_write_access");
 525        err = ext3_journal_get_write_access(handle, bh2);
 526        if (err) goto fail;
 527        spin_lock(sb_bgl_lock(sbi, group));
 528        le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 529        if (S_ISDIR(mode)) {
 530                le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 531        }
 532        spin_unlock(sb_bgl_lock(sbi, group));
 533        BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 534        err = ext3_journal_dirty_metadata(handle, bh2);
 535        if (err) goto fail;
 536
 537        percpu_counter_dec(&sbi->s_freeinodes_counter);
 538        if (S_ISDIR(mode))
 539                percpu_counter_inc(&sbi->s_dirs_counter);
 540
 541        inode->i_uid = current_fsuid();
 542        if (test_opt (sb, GRPID))
 543                inode->i_gid = dir->i_gid;
 544        else if (dir->i_mode & S_ISGID) {
 545                inode->i_gid = dir->i_gid;
 546                if (S_ISDIR(mode))
 547                        mode |= S_ISGID;
 548        } else
 549                inode->i_gid = current_fsgid();
 550        inode->i_mode = mode;
 551
 552        inode->i_ino = ino;
 553        /* This is the optimal IO size (for stat), not the fs block size */
 554        inode->i_blocks = 0;
 555        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 556
 557        memset(ei->i_data, 0, sizeof(ei->i_data));
 558        ei->i_dir_start_lookup = 0;
 559        ei->i_disksize = 0;
 560
 561        ei->i_flags =
 562                ext3_mask_flags(mode, EXT3_I(dir)->i_flags & EXT3_FL_INHERITED);
 563#ifdef EXT3_FRAGMENTS
 564        ei->i_faddr = 0;
 565        ei->i_frag_no = 0;
 566        ei->i_frag_size = 0;
 567#endif
 568        ei->i_file_acl = 0;
 569        ei->i_dir_acl = 0;
 570        ei->i_dtime = 0;
 571        ei->i_block_alloc_info = NULL;
 572        ei->i_block_group = group;
 573
 574        ext3_set_inode_flags(inode);
 575        if (IS_DIRSYNC(inode))
 576                handle->h_sync = 1;
 577        if (insert_inode_locked(inode) < 0) {
 578                err = -EINVAL;
 579                goto fail_drop;
 580        }
 581        spin_lock(&sbi->s_next_gen_lock);
 582        inode->i_generation = sbi->s_next_generation++;
 583        spin_unlock(&sbi->s_next_gen_lock);
 584
 585        ei->i_state = EXT3_STATE_NEW;
 586        ei->i_extra_isize =
 587                (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) ?
 588                sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE : 0;
 589
 590        ret = inode;
 591        if (vfs_dq_alloc_inode(inode)) {
 592                err = -EDQUOT;
 593                goto fail_drop;
 594        }
 595
 596        err = ext3_init_acl(handle, inode, dir);
 597        if (err)
 598                goto fail_free_drop;
 599
 600        err = ext3_init_security(handle,inode, dir);
 601        if (err)
 602                goto fail_free_drop;
 603
 604        err = ext3_mark_inode_dirty(handle, inode);
 605        if (err) {
 606                ext3_std_error(sb, err);
 607                goto fail_free_drop;
 608        }
 609
 610        ext3_debug("allocating inode %lu\n", inode->i_ino);
 611        goto really_out;
 612fail:
 613        ext3_std_error(sb, err);
 614out:
 615        iput(inode);
 616        ret = ERR_PTR(err);
 617really_out:
 618        brelse(bitmap_bh);
 619        return ret;
 620
 621fail_free_drop:
 622        vfs_dq_free_inode(inode);
 623
 624fail_drop:
 625        vfs_dq_drop(inode);
 626        inode->i_flags |= S_NOQUOTA;
 627        inode->i_nlink = 0;
 628        unlock_new_inode(inode);
 629        iput(inode);
 630        brelse(bitmap_bh);
 631        return ERR_PTR(err);
 632}
 633
 634/* Verify that we are loading a valid orphan from disk */
 635struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
 636{
 637        unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
 638        unsigned long block_group;
 639        int bit;
 640        struct buffer_head *bitmap_bh;
 641        struct inode *inode = NULL;
 642        long err = -EIO;
 643
 644        /* Error cases - e2fsck has already cleaned up for us */
 645        if (ino > max_ino) {
 646                ext3_warning(sb, __func__,
 647                             "bad orphan ino %lu!  e2fsck was run?", ino);
 648                goto error;
 649        }
 650
 651        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 652        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 653        bitmap_bh = read_inode_bitmap(sb, block_group);
 654        if (!bitmap_bh) {
 655                ext3_warning(sb, __func__,
 656                             "inode bitmap error for orphan %lu", ino);
 657                goto error;
 658        }
 659
 660        /* Having the inode bit set should be a 100% indicator that this
 661         * is a valid orphan (no e2fsck run on fs).  Orphans also include
 662         * inodes that were being truncated, so we can't check i_nlink==0.
 663         */
 664        if (!ext3_test_bit(bit, bitmap_bh->b_data))
 665                goto bad_orphan;
 666
 667        inode = ext3_iget(sb, ino);
 668        if (IS_ERR(inode))
 669                goto iget_failed;
 670
 671        /*
 672         * If the orphans has i_nlinks > 0 then it should be able to be
 673         * truncated, otherwise it won't be removed from the orphan list
 674         * during processing and an infinite loop will result.
 675         */
 676        if (inode->i_nlink && !ext3_can_truncate(inode))
 677                goto bad_orphan;
 678
 679        if (NEXT_ORPHAN(inode) > max_ino)
 680                goto bad_orphan;
 681        brelse(bitmap_bh);
 682        return inode;
 683
 684iget_failed:
 685        err = PTR_ERR(inode);
 686        inode = NULL;
 687bad_orphan:
 688        ext3_warning(sb, __func__,
 689                     "bad orphan inode %lu!  e2fsck was run?", ino);
 690        printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
 691               bit, (unsigned long long)bitmap_bh->b_blocknr,
 692               ext3_test_bit(bit, bitmap_bh->b_data));
 693        printk(KERN_NOTICE "inode=%p\n", inode);
 694        if (inode) {
 695                printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 696                       is_bad_inode(inode));
 697                printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 698                       NEXT_ORPHAN(inode));
 699                printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 700                printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
 701                /* Avoid freeing blocks if we got a bad deleted inode */
 702                if (inode->i_nlink == 0)
 703                        inode->i_blocks = 0;
 704                iput(inode);
 705        }
 706        brelse(bitmap_bh);
 707error:
 708        return ERR_PTR(err);
 709}
 710
 711unsigned long ext3_count_free_inodes (struct super_block * sb)
 712{
 713        unsigned long desc_count;
 714        struct ext3_group_desc *gdp;
 715        int i;
 716#ifdef EXT3FS_DEBUG
 717        struct ext3_super_block *es;
 718        unsigned long bitmap_count, x;
 719        struct buffer_head *bitmap_bh = NULL;
 720
 721        es = EXT3_SB(sb)->s_es;
 722        desc_count = 0;
 723        bitmap_count = 0;
 724        gdp = NULL;
 725        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 726                gdp = ext3_get_group_desc (sb, i, NULL);
 727                if (!gdp)
 728                        continue;
 729                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 730                brelse(bitmap_bh);
 731                bitmap_bh = read_inode_bitmap(sb, i);
 732                if (!bitmap_bh)
 733                        continue;
 734
 735                x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
 736                printk("group %d: stored = %d, counted = %lu\n",
 737                        i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 738                bitmap_count += x;
 739        }
 740        brelse(bitmap_bh);
 741        printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 742                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 743        return desc_count;
 744#else
 745        desc_count = 0;
 746        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 747                gdp = ext3_get_group_desc (sb, i, NULL);
 748                if (!gdp)
 749                        continue;
 750                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 751                cond_resched();
 752        }
 753        return desc_count;
 754#endif
 755}
 756
 757/* Called at mount-time, super-block is locked */
 758unsigned long ext3_count_dirs (struct super_block * sb)
 759{
 760        unsigned long count = 0;
 761        int i;
 762
 763        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 764                struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
 765                if (!gdp)
 766                        continue;
 767                count += le16_to_cpu(gdp->bg_used_dirs_count);
 768        }
 769        return count;
 770}
 771
 772