fs/ext2/ialloc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext2/ialloc.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  BSD ufs-inspired inode and directory allocation by
  11  *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
  12  *  Big-endian to little-endian byte-swapping/bitmaps by
  13  *        David S. Miller (davem@caip.rutgers.edu), 1995
  14  */
  15
  16 #include <linux/quotaops.h>
  17 #include <linux/sched.h>
  18 #include <linux/backing-dev.h>
  19 #include <linux/buffer_head.h>
  20 #include <linux/random.h>
  21 #include "ext2.h"
  22 #include "xattr.h"
  23 #include "acl.h"
  24
  25 /*
  26  * ialloc.c contains the inodes allocation and deallocation routines
  27  */
  28
  29 /*
  30  * The free inodes are managed by bitmaps.  A file system contains several
  31  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  32  * block for inodes, N blocks for the inode table and data blocks.
  33  *
  34  * The file system contains group descriptors which are located after the
  35  * super block.  Each descriptor contains the number of the bitmap block and
  36  * the free blocks count in the block.
  37  */
  38
  39
  40 /*
  41  * Read the inode allocation bitmap for a given block_group, reading
  42  * into the specified slot in the superblock's bitmap cache.
  43  *
  44  * Return buffer_head of bitmap on success or NULL.
  45  */
  46 static struct buffer_head *
  47 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
  48 {
  49         struct ext2_group_desc *desc;
  50         struct buffer_head *bh = NULL;
  51
  52         desc = ext2_get_group_desc(sb, block_group, NULL);
  53         if (!desc)
  54                 goto error_out;
  55
  56         bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
  57         if (!bh)
  58                 ext2_error(sb, "read_inode_bitmap",
  59                             "Cannot read inode bitmap - "
  60                             "block_group = %lu, inode_bitmap = %u",
  61                             block_group, le32_to_cpu(desc->bg_inode_bitmap));
  62 error_out:
  63         return bh;
  64 }
  65
  66 static void ext2_release_inode(struct super_block *sb, int group, int dir)
  67 {
  68         struct ext2_group_desc * desc;
  69         struct buffer_head *bh;
  70
  71         desc = ext2_get_group_desc(sb, group, &bh);
  72         if (!desc) {
  73                 ext2_error(sb, "ext2_release_inode",
  74                         "can't get descriptor for group %d", group);
  75                 return;
  76         }
  77
  78         spin_lock(sb_bgl_lock(EXT2_SB(sb), group));
  79         le16_add_cpu(&desc->bg_free_inodes_count, 1);
  80         if (dir)
  81                 le16_add_cpu(&desc->bg_used_dirs_count, -1);
  82         spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
  83         percpu_counter_inc(&EXT2_SB(sb)->s_freeinodes_counter);
  84         if (dir)
  85                 percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
  86         mark_buffer_dirty(bh);
  87 }
  88
  89 /*
  90  * NOTE! When we get the inode, we're the only people
  91  * that have access to it, and as such there are no
  92  * race conditions we have to worry about. The inode
  93  * is not on the hash-lists, and it cannot be reached
  94  * through the filesystem because the directory entry
  95  * has been deleted earlier.
  96  *
  97  * HOWEVER: we must make sure that we get no aliases,
  98  * which means that we have to call "clear_inode()"
  99  * _before_ we mark the inode not in use in the inode
 100  * bitmaps. Otherwise a newly created file might use
 101  * the same inode number (not actually the same pointer
 102  * though), and then we'd have two inodes sharing the
 103  * same inode number and space on the harddisk.
 104  */
 105 void ext2_free_inode (struct inode * inode)
 106 {
 107         struct super_block * sb = inode->i_sb;
 108         int is_directory;
 109         unsigned long ino;
 110         struct buffer_head *bitmap_bh;
 111         unsigned long block_group;
 112         unsigned long bit;
 113         struct ext2_super_block * es;
 114
 115         ino = inode->i_ino;
 116         ext2_debug ("freeing inode %lu\n", ino);
 117
 118         /*
 119          * Note: we must free any quota before locking the superblock,
 120          * as writing the quota to disk may need the lock as well.
 121          */
 122         /* Quota is already initialized in iput() */
 123         dquot_free_inode(inode);
 124         dquot_drop(inode);
 125
 126         es = EXT2_SB(sb)->s_es;
 127         is_directory = S_ISDIR(inode->i_mode);
 128
 129         if (ino < EXT2_FIRST_INO(sb) ||
 130             ino > le32_to_cpu(es->s_inodes_count)) {
 131                 ext2_error (sb, "ext2_free_inode",
 132                             "reserved or nonexistent inode %lu", ino);
 133                 return;
 134         }
 135         block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
 136         bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
 137         bitmap_bh = read_inode_bitmap(sb, block_group);
 138         if (!bitmap_bh)
 139                 return;
 140
 141         /* Ok, now we can actually update the inode bitmaps.. */
 142         if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
 143                                 bit, (void *) bitmap_bh->b_data))
 144                 ext2_error (sb, "ext2_free_inode",
 145                               "bit already cleared for inode %lu", ino);
 146         else
 147                 ext2_release_inode(sb, block_group, is_directory);
 148         mark_buffer_dirty(bitmap_bh);
 149         if (sb->s_flags & MS_SYNCHRONOUS)
 150                 sync_dirty_buffer(bitmap_bh);
 151
 152         brelse(bitmap_bh);
 153 }
 154
 155 /*
 156  * We perform asynchronous prereading of the new inode's inode block when
 157  * we create the inode, in the expectation that the inode will be written
 158  * back soon.  There are two reasons:
 159  *
 160  * - When creating a large number of files, the async prereads will be
 161  *   nicely merged into large reads
 162  * - When writing out a large number of inodes, we don't need to keep on
 163  *   stalling the writes while we read the inode block.
 164  *
 165  * FIXME: ext2_get_group_desc() needs to be simplified.
 166  */
 167 static void ext2_preread_inode(struct inode *inode)
 168 {
 169         unsigned long block_group;
 170         unsigned long offset;
 171         unsigned long block;
 172         struct ext2_group_desc * gdp;
 173         struct backing_dev_info *bdi;
 174
 175         bdi = inode_to_bdi(inode);
 176         if (bdi_read_congested(bdi))
 177                 return;
 178         if (bdi_write_congested(bdi))
 179                 return;
 180
 181         block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 182         gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
 183         if (gdp == NULL)
 184                 return;
 185
 186         /*
 187          * Figure out the offset within the block group inode table
 188          */
 189         offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
 190                                 EXT2_INODE_SIZE(inode->i_sb);
 191         block = le32_to_cpu(gdp->bg_inode_table) +
 192                                 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
 193         sb_breadahead(inode->i_sb, block);
 194 }
 195
 196 /*
 197  * There are two policies for allocating an inode.  If the new inode is
 198  * a directory, then a forward search is made for a block group with both
 199  * free space and a low directory-to-inode ratio; if that fails, then of
 200  * the groups with above-average free space, that group with the fewest
 201  * directories already is chosen.
 202  *
 203  * For other inodes, search forward from the parent directory\'s block
 204  * group to find a free inode.
 205  */
 206 static int find_group_dir(struct super_block *sb, struct inode *parent)
 207 {
 208         int ngroups = EXT2_SB(sb)->s_groups_count;
 209         int avefreei = ext2_count_free_inodes(sb) / ngroups;
 210         struct ext2_group_desc *desc, *best_desc = NULL;
 211         int group, best_group = -1;
 212
 213         for (group = 0; group < ngroups; group++) {
 214                 desc = ext2_get_group_desc (sb, group, NULL);
 215                 if (!desc || !desc->bg_free_inodes_count)
 216                         continue;
 217                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 218                         continue;
 219                 if (!best_desc ||
 220                     (le16_to_cpu(desc->bg_free_blocks_count) >
 221                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 222                         best_group = group;
 223                         best_desc = desc;
 224                 }
 225         }
 226         if (!best_desc)
 227                 return -1;
 228
 229         return best_group;
 230 }
 231
 232 /*
 233  * Orlov's allocator for directories.
 234  *
 235  * We always try to spread first-level directories.
 236  *
 237  * If there are blockgroups with both free inodes and free blocks counts
 238  * not worse than average we return one with smallest directory count.
 239  * Otherwise we simply return a random group.
 240  *
 241  * For the rest rules look so:
 242  *
 243  * It's OK to put directory into a group unless
 244  * it has too many directories already (max_dirs) or
 245  * it has too few free inodes left (min_inodes) or
 246  * it has too few free blocks left (min_blocks) or
 247  * it's already running too large debt (max_debt).
 248  * Parent's group is preferred, if it doesn't satisfy these
 249  * conditions we search cyclically through the rest. If none
 250  * of the groups look good we just look for a group with more
 251  * free inodes than average (starting at parent's group).
 252  *
 253  * Debt is incremented each time we allocate a directory and decremented
 254  * when we allocate an inode, within 0--255.
 255  */
 256
 257 #define INODE_COST 64
 258 #define BLOCK_COST 256
 259
 260 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 261 {
 262         int parent_group = EXT2_I(parent)->i_block_group;
 263         struct ext2_sb_info *sbi = EXT2_SB(sb);
 264         struct ext2_super_block *es = sbi->s_es;
 265         int ngroups = sbi->s_groups_count;
 266         int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
 267         int freei;
 268         int avefreei;
 269         int free_blocks;
 270         int avefreeb;
 271         int blocks_per_dir;
 272         int ndirs;
 273         int max_debt, max_dirs, min_blocks, min_inodes;
 274         int group = -1, i;
 275         struct ext2_group_desc *desc;
 276
 277         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 278         avefreei = freei / ngroups;
 279         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 280         avefreeb = free_blocks / ngroups;
 281         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 282
 283         if ((parent == d_inode(sb->s_root)) ||
 284             (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
 285                 struct ext2_group_desc *best_desc = NULL;
 286                 int best_ndir = inodes_per_group;
 287                 int best_group = -1;
 288
 289                 group = prandom_u32();
 290                 parent_group = (unsigned)group % ngroups;
 291                 for (i = 0; i < ngroups; i++) {
 292                         group = (parent_group + i) % ngroups;
 293                         desc = ext2_get_group_desc (sb, group, NULL);
 294                         if (!desc || !desc->bg_free_inodes_count)
 295                                 continue;
 296                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 297                                 continue;
 298                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 299                                 continue;
 300                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 301                                 continue;
 302                         best_group = group;
 303                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 304                         best_desc = desc;
 305                 }
 306                 if (best_group >= 0) {
 307                         desc = best_desc;
 308                         group = best_group;
 309                         goto found;
 310                 }
 311                 goto fallback;
 312         }
 313
 314         if (ndirs == 0)
 315                 ndirs = 1;      /* percpu_counters are approximate... */
 316
 317         blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
 318
 319         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 320         min_inodes = avefreei - inodes_per_group / 4;
 321         min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
 322
 323         max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
 324         if (max_debt * INODE_COST > inodes_per_group)
 325                 max_debt = inodes_per_group / INODE_COST;
 326         if (max_debt > 255)
 327                 max_debt = 255;
 328         if (max_debt == 0)
 329                 max_debt = 1;
 330
 331         for (i = 0; i < ngroups; i++) {
 332                 group = (parent_group + i) % ngroups;
 333                 desc = ext2_get_group_desc (sb, group, NULL);
 334                 if (!desc || !desc->bg_free_inodes_count)
 335                         continue;
 336                 if (sbi->s_debts[group] >= max_debt)
 337                         continue;
 338                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 339                         continue;
 340                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 341                         continue;
 342                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 343                         continue;
 344                 goto found;
 345         }
 346
 347 fallback:
 348         for (i = 0; i < ngroups; i++) {
 349                 group = (parent_group + i) % ngroups;
 350                 desc = ext2_get_group_desc (sb, group, NULL);
 351                 if (!desc || !desc->bg_free_inodes_count)
 352                         continue;
 353                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 354                         goto found;
 355         }
 356
 357         if (avefreei) {
 358                 /*
 359                  * The free-inodes counter is approximate, and for really small
 360                  * filesystems the above test can fail to find any blockgroups
 361                  */
 362                 avefreei = 0;
 363                 goto fallback;
 364         }
 365
 366         return -1;
 367
 368 found:
 369         return group;
 370 }
 371
 372 static int find_group_other(struct super_block *sb, struct inode *parent)
 373 {
 374         int parent_group = EXT2_I(parent)->i_block_group;
 375         int ngroups = EXT2_SB(sb)->s_groups_count;
 376         struct ext2_group_desc *desc;
 377         int group, i;
 378
 379         /*
 380          * Try to place the inode in its parent directory
 381          */
 382         group = parent_group;
 383         desc = ext2_get_group_desc (sb, group, NULL);
 384         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 385                         le16_to_cpu(desc->bg_free_blocks_count))
 386                 goto found;
 387
 388         /*
 389          * We're going to place this inode in a different blockgroup from its
 390          * parent.  We want to cause files in a common directory to all land in
 391          * the same blockgroup.  But we want files which are in a different
 392          * directory which shares a blockgroup with our parent to land in a
 393          * different blockgroup.
 394          *
 395          * So add our directory's i_ino into the starting point for the hash.
 396          */
 397         group = (group + parent->i_ino) % ngroups;
 398
 399         /*
 400          * Use a quadratic hash to find a group with a free inode and some
 401          * free blocks.
 402          */
 403         for (i = 1; i < ngroups; i <<= 1) {
 404                 group += i;
 405                 if (group >= ngroups)
 406                         group -= ngroups;
 407                 desc = ext2_get_group_desc (sb, group, NULL);
 408                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 409                                 le16_to_cpu(desc->bg_free_blocks_count))
 410                         goto found;
 411         }
 412
 413         /*
 414          * That failed: try linear search for a free inode, even if that group
 415          * has no free blocks.
 416          */
 417         group = parent_group;
 418         for (i = 0; i < ngroups; i++) {
 419                 if (++group >= ngroups)
 420                         group = 0;
 421                 desc = ext2_get_group_desc (sb, group, NULL);
 422                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 423                         goto found;
 424         }
 425
 426         return -1;
 427
 428 found:
 429         return group;
 430 }
 431
 432 struct inode *ext2_new_inode(struct inode *dir, umode_t mode,
 433                              const struct qstr *qstr)
 434 {
 435         struct super_block *sb;
 436         struct buffer_head *bitmap_bh = NULL;
 437         struct buffer_head *bh2;
 438         int group, i;
 439         ino_t ino = 0;
 440         struct inode * inode;
 441         struct ext2_group_desc *gdp;
 442         struct ext2_super_block *es;
 443         struct ext2_inode_info *ei;
 444         struct ext2_sb_info *sbi;
 445         int err;
 446
 447         sb = dir->i_sb;
 448         inode = new_inode(sb);
 449         if (!inode)
 450                 return ERR_PTR(-ENOMEM);
 451
 452         ei = EXT2_I(inode);
 453         sbi = EXT2_SB(sb);
 454         es = sbi->s_es;
 455         if (S_ISDIR(mode)) {
 456                 if (test_opt(sb, OLDALLOC))
 457                         group = find_group_dir(sb, dir);
 458                 else
 459                         group = find_group_orlov(sb, dir);
 460         } else
 461                 group = find_group_other(sb, dir);
 462
 463         if (group == -1) {
 464                 err = -ENOSPC;
 465                 goto fail;
 466         }
 467
 468         for (i = 0; i < sbi->s_groups_count; i++) {
 469                 gdp = ext2_get_group_desc(sb, group, &bh2);
 470                 if (!gdp) {
 471                         if (++group == sbi->s_groups_count)
 472                                 group = 0;
 473                         continue;
 474                 }
 475                 brelse(bitmap_bh);
 476                 bitmap_bh = read_inode_bitmap(sb, group);
 477                 if (!bitmap_bh) {
 478                         err = -EIO;
 479                         goto fail;
 480                 }
 481                 ino = 0;
 482
 483 repeat_in_this_group:
 484                 ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
 485                                               EXT2_INODES_PER_GROUP(sb), ino);
 486                 if (ino >= EXT2_INODES_PER_GROUP(sb)) {
 487                         /*
 488                          * Rare race: find_group_xx() decided that there were
 489                          * free inodes in this group, but by the time we tried
 490                          * to allocate one, they're all gone.  This can also
 491                          * occur because the counters which find_group_orlov()
 492                          * uses are approximate.  So just go and search the
 493                          * next block group.
 494                          */
 495                         if (++group == sbi->s_groups_count)
 496                                 group = 0;
 497                         continue;
 498                 }
 499                 if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
 500                                                 ino, bitmap_bh->b_data)) {
 501                         /* we lost this inode */
 502                         if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
 503                                 /* this group is exhausted, try next group */
 504                                 if (++group == sbi->s_groups_count)
 505                                         group = 0;
 506                                 continue;
 507                         }
 508                         /* try to find free inode in the same group */
 509                         goto repeat_in_this_group;
 510                 }
 511                 goto got;
 512         }
 513
 514         /*
 515          * Scanned all blockgroups.
 516          */
 517         err = -ENOSPC;
 518         goto fail;
 519 got:
 520         mark_buffer_dirty(bitmap_bh);
 521         if (sb->s_flags & MS_SYNCHRONOUS)
 522                 sync_dirty_buffer(bitmap_bh);
 523         brelse(bitmap_bh);
 524
 525         ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
 526         if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 527                 ext2_error (sb, "ext2_new_inode",
 528                             "reserved inode or inode > inodes count - "
 529                             "block_group = %d,inode=%lu", group,
 530                             (unsigned long) ino);
 531                 err = -EIO;
 532                 goto fail;
 533         }
 534
 535         percpu_counter_dec(&sbi->s_freeinodes_counter);
 536         if (S_ISDIR(mode))
 537                 percpu_counter_inc(&sbi->s_dirs_counter);
 538
 539         spin_lock(sb_bgl_lock(sbi, group));
 540         le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 541         if (S_ISDIR(mode)) {
 542                 if (sbi->s_debts[group] < 255)
 543                         sbi->s_debts[group]++;
 544                 le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 545         } else {
 546                 if (sbi->s_debts[group])
 547                         sbi->s_debts[group]--;
 548         }
 549         spin_unlock(sb_bgl_lock(sbi, group));
 550
 551         mark_buffer_dirty(bh2);
 552         if (test_opt(sb, GRPID)) {
 553                 inode->i_mode = mode;
 554                 inode->i_uid = current_fsuid();
 555                 inode->i_gid = dir->i_gid;
 556         } else
 557                 inode_init_owner(inode, dir, mode);
 558
 559         inode->i_ino = ino;
 560         inode->i_blocks = 0;
 561         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 562         memset(ei->i_data, 0, sizeof(ei->i_data));
 563         ei->i_flags =
 564                 ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED);
 565         ei->i_faddr = 0;
 566         ei->i_frag_no = 0;
 567         ei->i_frag_size = 0;
 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         ei->i_dir_start_lookup = 0;
 574         ei->i_state = EXT2_STATE_NEW;
 575         ext2_set_inode_flags(inode);
 576         spin_lock(&sbi->s_next_gen_lock);
 577         inode->i_generation = sbi->s_next_generation++;
 578         spin_unlock(&sbi->s_next_gen_lock);
 579         if (insert_inode_locked(inode) < 0) {
 580                 ext2_error(sb, "ext2_new_inode",
 581                            "inode number already in use - inode=%lu",
 582                            (unsigned long) ino);
 583                 err = -EIO;
 584                 goto fail;
 585         }
 586
 587         err = dquot_initialize(inode);
 588         if (err)
 589                 goto fail_drop;
 590
 591         err = dquot_alloc_inode(inode);
 592         if (err)
 593                 goto fail_drop;
 594
 595         err = ext2_init_acl(inode, dir);
 596         if (err)
 597                 goto fail_free_drop;
 598
 599         err = ext2_init_security(inode, dir, qstr);
 600         if (err)
 601                 goto fail_free_drop;
 602
 603         mark_inode_dirty(inode);
 604         ext2_debug("allocating inode %lu\n", inode->i_ino);
 605         ext2_preread_inode(inode);
 606         return inode;
 607
 608 fail_free_drop:
 609         dquot_free_inode(inode);
 610
 611 fail_drop:
 612         dquot_drop(inode);
 613         inode->i_flags |= S_NOQUOTA;
 614         clear_nlink(inode);
 615         unlock_new_inode(inode);
 616         iput(inode);
 617         return ERR_PTR(err);
 618
 619 fail:
 620         make_bad_inode(inode);
 621         iput(inode);
 622         return ERR_PTR(err);
 623 }
 624
 625 unsigned long ext2_count_free_inodes (struct super_block * sb)
 626 {
 627         struct ext2_group_desc *desc;
 628         unsigned long desc_count = 0;
 629         int i;
 630
 631 #ifdef EXT2FS_DEBUG
 632         struct ext2_super_block *es;
 633         unsigned long bitmap_count = 0;
 634         struct buffer_head *bitmap_bh = NULL;
 635
 636         es = EXT2_SB(sb)->s_es;
 637         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 638                 unsigned x;
 639
 640                 desc = ext2_get_group_desc (sb, i, NULL);
 641                 if (!desc)
 642                         continue;
 643                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 644                 brelse(bitmap_bh);
 645                 bitmap_bh = read_inode_bitmap(sb, i);
 646                 if (!bitmap_bh)
 647                         continue;
 648
 649                 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
 650                 printk("group %d: stored = %d, counted = %u\n",
 651                         i, le16_to_cpu(desc->bg_free_inodes_count), x);
 652                 bitmap_count += x;
 653         }
 654         brelse(bitmap_bh);
 655         printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
 656                 (unsigned long)
 657                 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
 658                 desc_count, bitmap_count);
 659         return desc_count;
 660 #else
 661         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 662                 desc = ext2_get_group_desc (sb, i, NULL);
 663                 if (!desc)
 664                         continue;
 665                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 666         }
 667         return desc_count;
 668 #endif
 669 }
 670
 671 /* Called at mount-time, super-block is locked */
 672 unsigned long ext2_count_dirs (struct super_block * sb)
 673 {
 674         unsigned long count = 0;
 675         int i;
 676
 677         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 678                 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
 679                 if (!gdp)
 680                         continue;
 681                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 682         }
 683         return count;
 684 }
 685