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