kernel/2.6.29.6-aldebaran-rt/fs/ext2/ialloc.c

   1 /*
   2  *  linux/fs/ext2/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@dcs.ed.ac.uk), 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/quotaops.h>
  16 #include <linux/sched.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/buffer_head.h>
  19 #include <linux/random.h>
  20 #include "ext2.h"
  21 #include "xattr.h"
  22 #include "acl.h"
  23
  24 /*
  25  * ialloc.c contains the inodes allocation and deallocation routines
  26  */
  27
  28 /*
  29  * The free inodes are managed by bitmaps.  A file system contains several
  30  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  31  * block for inodes, N blocks for the inode table and data blocks.
  32  *
  33  * The file system contains group descriptors which are located after the
  34  * super block.  Each descriptor contains the number of the bitmap block and
  35  * the free blocks count in the block.
  36  */
  37
  38
  39 /*
  40  * Read the inode allocation bitmap for a given block_group, reading
  41  * into the specified slot in the superblock's bitmap cache.
  42  *
  43  * Return buffer_head of bitmap on success or NULL.
  44  */
  45 static struct buffer_head *
  46 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
  47 {
  48         struct ext2_group_desc *desc;
  49         struct buffer_head *bh = NULL;
  50
  51         desc = ext2_get_group_desc(sb, block_group, NULL);
  52         if (!desc)
  53                 goto error_out;
  54
  55         bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
  56         if (!bh)
  57                 ext2_error(sb, "read_inode_bitmap",
  58                             "Cannot read inode bitmap - "
  59                             "block_group = %lu, inode_bitmap = %u",
  60                             block_group, le32_to_cpu(desc->bg_inode_bitmap));
  61 error_out:
  62         return bh;
  63 }
  64
  65 static void ext2_release_inode(struct super_block *sb, int group, int dir)
  66 {
  67         struct ext2_group_desc * desc;
  68         struct buffer_head *bh;
  69
  70         desc = ext2_get_group_desc(sb, group, &bh);
  71         if (!desc) {
  72                 ext2_error(sb, "ext2_release_inode",
  73                         "can't get descriptor for group %d", group);
  74                 return;
  75         }
  76
  77         spin_lock(sb_bgl_lock(EXT2_SB(sb), group));
  78         le16_add_cpu(&desc->bg_free_inodes_count, 1);
  79         if (dir)
  80                 le16_add_cpu(&desc->bg_used_dirs_count, -1);
  81         spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
  82         if (dir)
  83                 percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
  84         sb->s_dirt = 1;
  85         mark_buffer_dirty(bh);
  86 }
  87
  88 /*
  89  * NOTE! When we get the inode, we're the only people
  90  * that have access to it, and as such there are no
  91  * race conditions we have to worry about. The inode
  92  * is not on the hash-lists, and it cannot be reached
  93  * through the filesystem because the directory entry
  94  * has been deleted earlier.
  95  *
  96  * HOWEVER: we must make sure that we get no aliases,
  97  * which means that we have to call "clear_inode()"
  98  * _before_ we mark the inode not in use in the inode
  99  * bitmaps. Otherwise a newly created file might use
 100  * the same inode number (not actually the same pointer
 101  * though), and then we'd have two inodes sharing the
 102  * same inode number and space on the harddisk.
 103  */
 104 void ext2_free_inode (struct inode * inode)
 105 {
 106         struct super_block * sb = inode->i_sb;
 107         int is_directory;
 108         unsigned long ino;
 109         struct buffer_head *bitmap_bh = NULL;
 110         unsigned long block_group;
 111         unsigned long bit;
 112         struct ext2_super_block * es;
 113
 114         ino = inode->i_ino;
 115         ext2_debug ("freeing inode %lu\n", ino);
 116
 117         /*
 118          * Note: we must free any quota before locking the superblock,
 119          * as writing the quota to disk may need the lock as well.
 120          */
 121         if (!is_bad_inode(inode)) {
 122                 /* Quota is already initialized in iput() */
 123                 ext2_xattr_delete_inode(inode);
 124                 DQUOT_FREE_INODE(inode);
 125                 DQUOT_DROP(inode);
 126         }
 127
 128         es = EXT2_SB(sb)->s_es;
 129         is_directory = S_ISDIR(inode->i_mode);
 130
 131         /* Do this BEFORE marking the inode not in use or returning an error */
 132         clear_inode (inode);
 133
 134         if (ino < EXT2_FIRST_INO(sb) ||
 135             ino > le32_to_cpu(es->s_inodes_count)) {
 136                 ext2_error (sb, "ext2_free_inode",
 137                             "reserved or nonexistent inode %lu", ino);
 138                 goto error_return;
 139         }
 140         block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
 141         bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
 142         brelse(bitmap_bh);
 143         bitmap_bh = read_inode_bitmap(sb, block_group);
 144         if (!bitmap_bh)
 145                 goto error_return;
 146
 147         /* Ok, now we can actually update the inode bitmaps.. */
 148         if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
 149                                 bit, (void *) bitmap_bh->b_data))
 150                 ext2_error (sb, "ext2_free_inode",
 151                               "bit already cleared for inode %lu", ino);
 152         else
 153                 ext2_release_inode(sb, block_group, is_directory);
 154         mark_buffer_dirty(bitmap_bh);
 155         if (sb->s_flags & MS_SYNCHRONOUS)
 156                 sync_dirty_buffer(bitmap_bh);
 157 error_return:
 158         brelse(bitmap_bh);
 159 }
 160
 161 /*
 162  * We perform asynchronous prereading of the new inode's inode block when
 163  * we create the inode, in the expectation that the inode will be written
 164  * back soon.  There are two reasons:
 165  *
 166  * - When creating a large number of files, the async prereads will be
 167  *   nicely merged into large reads
 168  * - When writing out a large number of inodes, we don't need to keep on
 169  *   stalling the writes while we read the inode block.
 170  *
 171  * FIXME: ext2_get_group_desc() needs to be simplified.
 172  */
 173 static void ext2_preread_inode(struct inode *inode)
 174 {
 175         unsigned long block_group;
 176         unsigned long offset;
 177         unsigned long block;
 178         struct ext2_group_desc * gdp;
 179         struct backing_dev_info *bdi;
 180
 181         bdi = inode->i_mapping->backing_dev_info;
 182         if (bdi_read_congested(bdi))
 183                 return;
 184         if (bdi_write_congested(bdi))
 185                 return;
 186
 187         block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 188         gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
 189         if (gdp == NULL)
 190                 return;
 191
 192         /*
 193          * Figure out the offset within the block group inode table
 194          */
 195         offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
 196                                 EXT2_INODE_SIZE(inode->i_sb);
 197         block = le32_to_cpu(gdp->bg_inode_table) +
 198                                 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
 199         sb_breadahead(inode->i_sb, block);
 200 }
 201
 202 /*
 203  * There are two policies for allocating an inode.  If the new inode is
 204  * a directory, then a forward search is made for a block group with both
 205  * free space and a low directory-to-inode ratio; if that fails, then of
 206  * the groups with above-average free space, that group with the fewest
 207  * directories already is chosen.
 208  *
 209  * For other inodes, search forward from the parent directory\'s block
 210  * group to find a free inode.
 211  */
 212 static int find_group_dir(struct super_block *sb, struct inode *parent)
 213 {
 214         int ngroups = EXT2_SB(sb)->s_groups_count;
 215         int avefreei = ext2_count_free_inodes(sb) / ngroups;
 216         struct ext2_group_desc *desc, *best_desc = NULL;
 217         int group, best_group = -1;
 218
 219         for (group = 0; group < ngroups; group++) {
 220                 desc = ext2_get_group_desc (sb, group, NULL);
 221                 if (!desc || !desc->bg_free_inodes_count)
 222                         continue;
 223                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 224                         continue;
 225                 if (!best_desc ||
 226                     (le16_to_cpu(desc->bg_free_blocks_count) >
 227                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 228                         best_group = group;
 229                         best_desc = desc;
 230                 }
 231         }
 232         if (!best_desc)
 233                 return -1;
 234
 235         return best_group;
 236 }
 237
 238 /*
 239  * Orlov's allocator for directories.
 240  *
 241  * We always try to spread first-level directories.
 242  *
 243  * If there are blockgroups with both free inodes and free blocks counts
 244  * not worse than average we return one with smallest directory count.
 245  * Otherwise we simply return a random group.
 246  *
 247  * For the rest rules look so:
 248  *
 249  * It's OK to put directory into a group unless
 250  * it has too many directories already (max_dirs) or
 251  * it has too few free inodes left (min_inodes) or
 252  * it has too few free blocks left (min_blocks) or
 253  * it's already running too large debt (max_debt).
 254  * Parent's group is preferred, if it doesn't satisfy these
 255  * conditions we search cyclically through the rest. If none
 256  * of the groups look good we just look for a group with more
 257  * free inodes than average (starting at parent's group).
 258  *
 259  * Debt is incremented each time we allocate a directory and decremented
 260  * when we allocate an inode, within 0--255.
 261  */
 262
 263 #define INODE_COST 64
 264 #define BLOCK_COST 256
 265
 266 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 267 {
 268         int parent_group = EXT2_I(parent)->i_block_group;
 269         struct ext2_sb_info *sbi = EXT2_SB(sb);
 270         struct ext2_super_block *es = sbi->s_es;
 271         int ngroups = sbi->s_groups_count;
 272         int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
 273         int freei;
 274         int avefreei;
 275         int free_blocks;
 276         int avefreeb;
 277         int blocks_per_dir;
 278         int ndirs;
 279         int max_debt, max_dirs, min_blocks, min_inodes;
 280         int group = -1, i;
 281         struct ext2_group_desc *desc;
 282
 283         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 284         avefreei = freei / ngroups;
 285         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 286         avefreeb = free_blocks / ngroups;
 287         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 288
 289         if ((parent == sb->s_root->d_inode) ||
 290             (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
 291                 struct ext2_group_desc *best_desc = NULL;
 292                 int best_ndir = inodes_per_group;
 293                 int best_group = -1;
 294
 295                 get_random_bytes(&group, sizeof(group));
 296                 parent_group = (unsigned)group % ngroups;
 297                 for (i = 0; i < ngroups; i++) {
 298                         group = (parent_group + i) % ngroups;
 299                         desc = ext2_get_group_desc (sb, group, NULL);
 300                         if (!desc || !desc->bg_free_inodes_count)
 301                                 continue;
 302                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 303                                 continue;
 304                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 305                                 continue;
 306                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 307                                 continue;
 308                         best_group = group;
 309                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 310                         best_desc = desc;
 311                 }
 312                 if (best_group >= 0) {
 313                         desc = best_desc;
 314                         group = best_group;
 315                         goto found;
 316                 }
 317                 goto fallback;
 318         }
 319
 320         if (ndirs == 0)
 321                 ndirs = 1;      /* percpu_counters are approximate... */
 322
 323         blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
 324
 325         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 326         min_inodes = avefreei - inodes_per_group / 4;
 327         min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
 328
 329         max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
 330         if (max_debt * INODE_COST > inodes_per_group)
 331                 max_debt = inodes_per_group / INODE_COST;
 332         if (max_debt > 255)
 333                 max_debt = 255;
 334         if (max_debt == 0)
 335                 max_debt = 1;
 336
 337         for (i = 0; i < ngroups; i++) {
 338                 group = (parent_group + i) % ngroups;
 339                 desc = ext2_get_group_desc (sb, group, NULL);
 340                 if (!desc || !desc->bg_free_inodes_count)
 341                         continue;
 342                 if (sbi->s_debts[group] >= max_debt)
 343                         continue;
 344                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 345                         continue;
 346                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 347                         continue;
 348                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 349                         continue;
 350                 goto found;
 351         }
 352
 353 fallback:
 354         for (i = 0; i < ngroups; i++) {
 355                 group = (parent_group + i) % ngroups;
 356                 desc = ext2_get_group_desc (sb, group, NULL);
 357                 if (!desc || !desc->bg_free_inodes_count)
 358                         continue;
 359                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 360                         goto found;
 361         }
 362
 363         if (avefreei) {
 364                 /*
 365                  * The free-inodes counter is approximate, and for really small
 366                  * filesystems the above test can fail to find any blockgroups
 367                  */
 368                 avefreei = 0;
 369                 goto fallback;
 370         }
 371
 372         return -1;
 373
 374 found:
 375         return group;
 376 }
 377
 378 static int find_group_other(struct super_block *sb, struct inode *parent)
 379 {
 380         int parent_group = EXT2_I(parent)->i_block_group;
 381         int ngroups = EXT2_SB(sb)->s_groups_count;
 382         struct ext2_group_desc *desc;
 383         int group, i;
 384
 385         /*
 386          * Try to place the inode in its parent directory
 387          */
 388         group = parent_group;
 389         desc = ext2_get_group_desc (sb, group, NULL);
 390         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 391                         le16_to_cpu(desc->bg_free_blocks_count))
 392                 goto found;
 393
 394         /*
 395          * We're going to place this inode in a different blockgroup from its
 396          * parent.  We want to cause files in a common directory to all land in
 397          * the same blockgroup.  But we want files which are in a different
 398          * directory which shares a blockgroup with our parent to land in a
 399          * different blockgroup.
 400          *
 401          * So add our directory's i_ino into the starting point for the hash.
 402          */
 403         group = (group + parent->i_ino) % ngroups;
 404
 405         /*
 406          * Use a quadratic hash to find a group with a free inode and some
 407          * free blocks.
 408          */
 409         for (i = 1; i < ngroups; i <<= 1) {
 410                 group += i;
 411                 if (group >= ngroups)
 412                         group -= ngroups;
 413                 desc = ext2_get_group_desc (sb, group, NULL);
 414                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 415                                 le16_to_cpu(desc->bg_free_blocks_count))
 416                         goto found;
 417         }
 418
 419         /*
 420          * That failed: try linear search for a free inode, even if that group
 421          * has no free blocks.
 422          */
 423         group = parent_group;
 424         for (i = 0; i < ngroups; i++) {
 425                 if (++group >= ngroups)
 426                         group = 0;
 427                 desc = ext2_get_group_desc (sb, group, NULL);
 428                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 429                         goto found;
 430         }
 431
 432         return -1;
 433
 434 found:
 435         return group;
 436 }
 437
 438 struct inode *ext2_new_inode(struct inode *dir, int mode)
 439 {
 440         struct super_block *sb;
 441         struct buffer_head *bitmap_bh = NULL;
 442         struct buffer_head *bh2;
 443         int group, i;
 444         ino_t ino = 0;
 445         struct inode * inode;
 446         struct ext2_group_desc *gdp;
 447         struct ext2_super_block *es;
 448         struct ext2_inode_info *ei;
 449         struct ext2_sb_info *sbi;
 450         int err;
 451
 452         sb = dir->i_sb;
 453         inode = new_inode(sb);
 454         if (!inode)
 455                 return ERR_PTR(-ENOMEM);
 456
 457         ei = EXT2_I(inode);
 458         sbi = EXT2_SB(sb);
 459         es = sbi->s_es;
 460         if (S_ISDIR(mode)) {
 461                 if (test_opt(sb, OLDALLOC))
 462                         group = find_group_dir(sb, dir);
 463                 else
 464                         group = find_group_orlov(sb, dir);
 465         } else
 466                 group = find_group_other(sb, dir);
 467
 468         if (group == -1) {
 469                 err = -ENOSPC;
 470                 goto fail;
 471         }
 472
 473         for (i = 0; i < sbi->s_groups_count; i++) {
 474                 gdp = ext2_get_group_desc(sb, group, &bh2);
 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_add(&sbi->s_freeinodes_counter, -1);
 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         sb->s_dirt = 1;
 552         mark_buffer_dirty(bh2);
 553         inode->i_uid = current_fsuid();
 554         if (test_opt (sb, GRPID))
 555                 inode->i_gid = dir->i_gid;
 556         else if (dir->i_mode & S_ISGID) {
 557                 inode->i_gid = dir->i_gid;
 558                 if (S_ISDIR(mode))
 559                         mode |= S_ISGID;
 560         } else
 561                 inode->i_gid = current_fsgid();
 562         inode->i_mode = mode;
 563
 564         inode->i_ino = ino;
 565         inode->i_blocks = 0;
 566         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 567         memset(ei->i_data, 0, sizeof(ei->i_data));
 568         ei->i_flags =
 569                 ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED);
 570         ei->i_faddr = 0;
 571         ei->i_frag_no = 0;
 572         ei->i_frag_size = 0;
 573         ei->i_file_acl = 0;
 574         ei->i_dir_acl = 0;
 575         ei->i_dtime = 0;
 576         ei->i_block_alloc_info = NULL;
 577         ei->i_block_group = group;
 578         ei->i_dir_start_lookup = 0;
 579         ei->i_state = EXT2_STATE_NEW;
 580         ext2_set_inode_flags(inode);
 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         if (insert_inode_locked(inode) < 0) {
 585                 err = -EINVAL;
 586                 goto fail_drop;
 587         }
 588
 589         if (DQUOT_ALLOC_INODE(inode)) {
 590                 err = -EDQUOT;
 591                 goto fail_drop;
 592         }
 593
 594         err = ext2_init_acl(inode, dir);
 595         if (err)
 596                 goto fail_free_drop;
 597
 598         err = ext2_init_security(inode,dir);
 599         if (err)
 600                 goto fail_free_drop;
 601
 602         mark_inode_dirty(inode);
 603         ext2_debug("allocating inode %lu\n", inode->i_ino);
 604         ext2_preread_inode(inode);
 605         return inode;
 606
 607 fail_free_drop:
 608         DQUOT_FREE_INODE(inode);
 609
 610 fail_drop:
 611         DQUOT_DROP(inode);
 612         inode->i_flags |= S_NOQUOTA;
 613         inode->i_nlink = 0;
 614         unlock_new_inode(inode);
 615         iput(inode);
 616         return ERR_PTR(err);
 617
 618 fail:
 619         make_bad_inode(inode);
 620         iput(inode);
 621         return ERR_PTR(err);
 622 }
 623
 624 unsigned long ext2_count_free_inodes (struct super_block * sb)
 625 {
 626         struct ext2_group_desc *desc;
 627         unsigned long desc_count = 0;
 628         int i;
 629
 630 #ifdef EXT2FS_DEBUG
 631         struct ext2_super_block *es;
 632         unsigned long bitmap_count = 0;
 633         struct buffer_head *bitmap_bh = NULL;
 634
 635         es = EXT2_SB(sb)->s_es;
 636         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 637                 unsigned x;
 638
 639                 desc = ext2_get_group_desc (sb, i, NULL);
 640                 if (!desc)
 641                         continue;
 642                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 643                 brelse(bitmap_bh);
 644                 bitmap_bh = read_inode_bitmap(sb, i);
 645                 if (!bitmap_bh)
 646                         continue;
 647
 648                 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
 649                 printk("group %d: stored = %d, counted = %u\n",
 650                         i, le16_to_cpu(desc->bg_free_inodes_count), x);
 651                 bitmap_count += x;
 652         }
 653         brelse(bitmap_bh);
 654         printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
 655                 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
 656                 desc_count, bitmap_count);
 657         return desc_count;
 658 #else
 659         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 660                 desc = ext2_get_group_desc (sb, i, NULL);
 661                 if (!desc)
 662                         continue;
 663                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 664         }
 665         return desc_count;
 666 #endif
 667 }
 668
 669 /* Called at mount-time, super-block is locked */
 670 unsigned long ext2_count_dirs (struct super_block * sb)
 671 {
 672         unsigned long count = 0;
 673         int i;
 674
 675         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 676                 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
 677                 if (!gdp)
 678                         continue;
 679                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 680         }
 681         return count;
 682 }
 683