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;
 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                 return;
 139         }
 140         block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
 141         bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
 142         bitmap_bh = read_inode_bitmap(sb, block_group);
 143         if (!bitmap_bh)
 144                 return;
 145
 146         /* Ok, now we can actually update the inode bitmaps.. */
 147         if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
 148                                 bit, (void *) bitmap_bh->b_data))
 149                 ext2_error (sb, "ext2_free_inode",
 150                               "bit already cleared for inode %lu", ino);
 151         else
 152                 ext2_release_inode(sb, block_group, is_directory);
 153         mark_buffer_dirty(bitmap_bh);
 154         if (sb->s_flags & MS_SYNCHRONOUS)
 155                 sync_dirty_buffer(bitmap_bh);
 156
 157         brelse(bitmap_bh);
 158 }
 159
 160 /*
 161  * We perform asynchronous prereading of the new inode's inode block when
 162  * we create the inode, in the expectation that the inode will be written
 163  * back soon.  There are two reasons:
 164  *
 165  * - When creating a large number of files, the async prereads will be
 166  *   nicely merged into large reads
 167  * - When writing out a large number of inodes, we don't need to keep on
 168  *   stalling the writes while we read the inode block.
 169  *
 170  * FIXME: ext2_get_group_desc() needs to be simplified.
 171  */
 172 static void ext2_preread_inode(struct inode *inode)
 173 {
 174         unsigned long block_group;
 175         unsigned long offset;
 176         unsigned long block;
 177         struct ext2_group_desc * gdp;
 178         struct backing_dev_info *bdi;
 179
 180         bdi = inode->i_mapping->backing_dev_info;
 181         if (bdi_read_congested(bdi))
 182                 return;
 183         if (bdi_write_congested(bdi))
 184                 return;
 185
 186         block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 187         gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
 188         if (gdp == NULL)
 189                 return;
 190
 191         /*
 192          * Figure out the offset within the block group inode table
 193          */
 194         offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
 195                                 EXT2_INODE_SIZE(inode->i_sb);
 196         block = le32_to_cpu(gdp->bg_inode_table) +
 197                                 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
 198         sb_breadahead(inode->i_sb, block);
 199 }
 200
 201 /*
 202  * There are two policies for allocating an inode.  If the new inode is
 203  * a directory, then a forward search is made for a block group with both
 204  * free space and a low directory-to-inode ratio; if that fails, then of
 205  * the groups with above-average free space, that group with the fewest
 206  * directories already is chosen.
 207  *
 208  * For other inodes, search forward from the parent directory\'s block
 209  * group to find a free inode.
 210  */
 211 static int find_group_dir(struct super_block *sb, struct inode *parent)
 212 {
 213         int ngroups = EXT2_SB(sb)->s_groups_count;
 214         int avefreei = ext2_count_free_inodes(sb) / ngroups;
 215         struct ext2_group_desc *desc, *best_desc = NULL;
 216         int group, best_group = -1;
 217
 218         for (group = 0; group < ngroups; group++) {
 219                 desc = ext2_get_group_desc (sb, group, NULL);
 220                 if (!desc || !desc->bg_free_inodes_count)
 221                         continue;
 222                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 223                         continue;
 224                 if (!best_desc ||
 225                     (le16_to_cpu(desc->bg_free_blocks_count) >
 226                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 227                         best_group = group;
 228                         best_desc = desc;
 229                 }
 230         }
 231         if (!best_desc)
 232                 return -1;
 233
 234         return best_group;
 235 }
 236
 237 /*
 238  * Orlov's allocator for directories.
 239  *
 240  * We always try to spread first-level directories.
 241  *
 242  * If there are blockgroups with both free inodes and free blocks counts
 243  * not worse than average we return one with smallest directory count.
 244  * Otherwise we simply return a random group.
 245  *
 246  * For the rest rules look so:
 247  *
 248  * It's OK to put directory into a group unless
 249  * it has too many directories already (max_dirs) or
 250  * it has too few free inodes left (min_inodes) or
 251  * it has too few free blocks left (min_blocks) or
 252  * it's already running too large debt (max_debt).
 253  * Parent's group is preferred, if it doesn't satisfy these
 254  * conditions we search cyclically through the rest. If none
 255  * of the groups look good we just look for a group with more
 256  * free inodes than average (starting at parent's group).
 257  *
 258  * Debt is incremented each time we allocate a directory and decremented
 259  * when we allocate an inode, within 0--255.
 260  */
 261
 262 #define INODE_COST 64
 263 #define BLOCK_COST 256
 264
 265 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 266 {
 267         int parent_group = EXT2_I(parent)->i_block_group;
 268         struct ext2_sb_info *sbi = EXT2_SB(sb);
 269         struct ext2_super_block *es = sbi->s_es;
 270         int ngroups = sbi->s_groups_count;
 271         int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
 272         int freei;
 273         int avefreei;
 274         int free_blocks;
 275         int avefreeb;
 276         int blocks_per_dir;
 277         int ndirs;
 278         int max_debt, max_dirs, min_blocks, min_inodes;
 279         int group = -1, i;
 280         struct ext2_group_desc *desc;
 281
 282         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 283         avefreei = freei / ngroups;
 284         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 285         avefreeb = free_blocks / ngroups;
 286         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 287
 288         if ((parent == sb->s_root->d_inode) ||
 289             (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
 290                 struct ext2_group_desc *best_desc = NULL;
 291                 int best_ndir = inodes_per_group;
 292                 int best_group = -1;
 293
 294                 get_random_bytes(&group, sizeof(group));
 295                 parent_group = (unsigned)group % ngroups;
 296                 for (i = 0; i < ngroups; i++) {
 297                         group = (parent_group + i) % ngroups;
 298                         desc = ext2_get_group_desc (sb, group, NULL);
 299                         if (!desc || !desc->bg_free_inodes_count)
 300                                 continue;
 301                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 302                                 continue;
 303                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 304                                 continue;
 305                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 306                                 continue;
 307                         best_group = group;
 308                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 309                         best_desc = desc;
 310                 }
 311                 if (best_group >= 0) {
 312                         desc = best_desc;
 313                         group = best_group;
 314                         goto found;
 315                 }
 316                 goto fallback;
 317         }
 318
 319         if (ndirs == 0)
 320                 ndirs = 1;      /* percpu_counters are approximate... */
 321
 322         blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
 323
 324         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 325         min_inodes = avefreei - inodes_per_group / 4;
 326         min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
 327
 328         max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
 329         if (max_debt * INODE_COST > inodes_per_group)
 330                 max_debt = inodes_per_group / INODE_COST;
 331         if (max_debt > 255)
 332                 max_debt = 255;
 333         if (max_debt == 0)
 334                 max_debt = 1;
 335
 336         for (i = 0; i < ngroups; i++) {
 337                 group = (parent_group + i) % ngroups;
 338                 desc = ext2_get_group_desc (sb, group, NULL);
 339                 if (!desc || !desc->bg_free_inodes_count)
 340                         continue;
 341                 if (sbi->s_debts[group] >= max_debt)
 342                         continue;
 343                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 344                         continue;
 345                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 346                         continue;
 347                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 348                         continue;
 349                 goto found;
 350         }
 351
 352 fallback:
 353         for (i = 0; i < ngroups; i++) {
 354                 group = (parent_group + i) % ngroups;
 355                 desc = ext2_get_group_desc (sb, group, NULL);
 356                 if (!desc || !desc->bg_free_inodes_count)
 357                         continue;
 358                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 359                         goto found;
 360         }
 361
 362         if (avefreei) {
 363                 /*
 364                  * The free-inodes counter is approximate, and for really small
 365                  * filesystems the above test can fail to find any blockgroups
 366                  */
 367                 avefreei = 0;
 368                 goto fallback;
 369         }
 370
 371         return -1;
 372
 373 found:
 374         return group;
 375 }
 376
 377 static int find_group_other(struct super_block *sb, struct inode *parent)
 378 {
 379         int parent_group = EXT2_I(parent)->i_block_group;
 380         int ngroups = EXT2_SB(sb)->s_groups_count;
 381         struct ext2_group_desc *desc;
 382         int group, i;
 383
 384         /*
 385          * Try to place the inode in its parent directory
 386          */
 387         group = parent_group;
 388         desc = ext2_get_group_desc (sb, group, NULL);
 389         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 390                         le16_to_cpu(desc->bg_free_blocks_count))
 391                 goto found;
 392
 393         /*
 394          * We're going to place this inode in a different blockgroup from its
 395          * parent.  We want to cause files in a common directory to all land in
 396          * the same blockgroup.  But we want files which are in a different
 397          * directory which shares a blockgroup with our parent to land in a
 398          * different blockgroup.
 399          *
 400          * So add our directory's i_ino into the starting point for the hash.
 401          */
 402         group = (group + parent->i_ino) % ngroups;
 403
 404         /*
 405          * Use a quadratic hash to find a group with a free inode and some
 406          * free blocks.
 407          */
 408         for (i = 1; i < ngroups; i <<= 1) {
 409                 group += i;
 410                 if (group >= ngroups)
 411                         group -= ngroups;
 412                 desc = ext2_get_group_desc (sb, group, NULL);
 413                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 414                                 le16_to_cpu(desc->bg_free_blocks_count))
 415                         goto found;
 416         }
 417
 418         /*
 419          * That failed: try linear search for a free inode, even if that group
 420          * has no free blocks.
 421          */
 422         group = parent_group;
 423         for (i = 0; i < ngroups; i++) {
 424                 if (++group >= ngroups)
 425                         group = 0;
 426                 desc = ext2_get_group_desc (sb, group, NULL);
 427                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 428                         goto found;
 429         }
 430
 431         return -1;
 432
 433 found:
 434         return group;
 435 }
 436
 437 struct inode *ext2_new_inode(struct inode *dir, int mode)
 438 {
 439         struct super_block *sb;
 440         struct buffer_head *bitmap_bh = NULL;
 441         struct buffer_head *bh2;
 442         int group, i;
 443         ino_t ino = 0;
 444         struct inode * inode;
 445         struct ext2_group_desc *gdp;
 446         struct ext2_super_block *es;
 447         struct ext2_inode_info *ei;
 448         struct ext2_sb_info *sbi;
 449         int err;
 450
 451         sb = dir->i_sb;
 452         inode = new_inode(sb);
 453         if (!inode)
 454                 return ERR_PTR(-ENOMEM);
 455
 456         ei = EXT2_I(inode);
 457         sbi = EXT2_SB(sb);
 458         es = sbi->s_es;
 459         if (S_ISDIR(mode)) {
 460                 if (test_opt(sb, OLDALLOC))
 461                         group = find_group_dir(sb, dir);
 462                 else
 463                         group = find_group_orlov(sb, dir);
 464         } else
 465                 group = find_group_other(sb, dir);
 466
 467         if (group == -1) {
 468                 err = -ENOSPC;
 469                 goto fail;
 470         }
 471
 472         for (i = 0; i < sbi->s_groups_count; i++) {
 473                 gdp = ext2_get_group_desc(sb, group, &bh2);
 474                 brelse(bitmap_bh);
 475                 bitmap_bh = read_inode_bitmap(sb, group);
 476                 if (!bitmap_bh) {
 477                         err = -EIO;
 478                         goto fail;
 479                 }
 480                 ino = 0;
 481
 482 repeat_in_this_group:
 483                 ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
 484                                               EXT2_INODES_PER_GROUP(sb), ino);
 485                 if (ino >= EXT2_INODES_PER_GROUP(sb)) {
 486                         /*
 487                          * Rare race: find_group_xx() decided that there were
 488                          * free inodes in this group, but by the time we tried
 489                          * to allocate one, they're all gone.  This can also
 490                          * occur because the counters which find_group_orlov()
 491                          * uses are approximate.  So just go and search the
 492                          * next block group.
 493                          */
 494                         if (++group == sbi->s_groups_count)
 495                                 group = 0;
 496                         continue;
 497                 }
 498                 if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
 499                                                 ino, bitmap_bh->b_data)) {
 500                         /* we lost this inode */
 501                         if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
 502                                 /* this group is exhausted, try next group */
 503                                 if (++group == sbi->s_groups_count)
 504                                         group = 0;
 505                                 continue;
 506                         }
 507                         /* try to find free inode in the same group */
 508                         goto repeat_in_this_group;
 509                 }
 510                 goto got;
 511         }
 512
 513         /*
 514          * Scanned all blockgroups.
 515          */
 516         err = -ENOSPC;
 517         goto fail;
 518 got:
 519         mark_buffer_dirty(bitmap_bh);
 520         if (sb->s_flags & MS_SYNCHRONOUS)
 521                 sync_dirty_buffer(bitmap_bh);
 522         brelse(bitmap_bh);
 523
 524         ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
 525         if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 526                 ext2_error (sb, "ext2_new_inode",
 527                             "reserved inode or inode > inodes count - "
 528                             "block_group = %d,inode=%lu", group,
 529                             (unsigned long) ino);
 530                 err = -EIO;
 531                 goto fail;
 532         }
 533
 534         percpu_counter_add(&sbi->s_freeinodes_counter, -1);
 535         if (S_ISDIR(mode))
 536                 percpu_counter_inc(&sbi->s_dirs_counter);
 537
 538         spin_lock(sb_bgl_lock(sbi, group));
 539         le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 540         if (S_ISDIR(mode)) {
 541                 if (sbi->s_debts[group] < 255)
 542                         sbi->s_debts[group]++;
 543                 le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 544         } else {
 545                 if (sbi->s_debts[group])
 546                         sbi->s_debts[group]--;
 547         }
 548         spin_unlock(sb_bgl_lock(sbi, group));
 549
 550         sb->s_dirt = 1;
 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_SEC;
 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                 err = -EINVAL;
 581                 goto fail_drop;
 582         }
 583
 584         dquot_initialize(inode);
 585         err = dquot_alloc_inode(inode);
 586         if (err)
 587                 goto fail_drop;
 588
 589         err = ext2_init_acl(inode, dir);
 590         if (err)
 591                 goto fail_free_drop;
 592
 593         err = ext2_init_security(inode,dir);
 594         if (err)
 595                 goto fail_free_drop;
 596
 597         mark_inode_dirty(inode);
 598         ext2_debug("allocating inode %lu\n", inode->i_ino);
 599         ext2_preread_inode(inode);
 600         return inode;
 601
 602 fail_free_drop:
 603         dquot_free_inode(inode);
 604
 605 fail_drop:
 606         dquot_drop(inode);
 607         inode->i_flags |= S_NOQUOTA;
 608         inode->i_nlink = 0;
 609         unlock_new_inode(inode);
 610         iput(inode);
 611         return ERR_PTR(err);
 612
 613 fail:
 614         make_bad_inode(inode);
 615         iput(inode);
 616         return ERR_PTR(err);
 617 }
 618
 619 unsigned long ext2_count_free_inodes (struct super_block * sb)
 620 {
 621         struct ext2_group_desc *desc;
 622         unsigned long desc_count = 0;
 623         int i;
 624
 625 #ifdef EXT2FS_DEBUG
 626         struct ext2_super_block *es;
 627         unsigned long bitmap_count = 0;
 628         struct buffer_head *bitmap_bh = NULL;
 629
 630         es = EXT2_SB(sb)->s_es;
 631         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 632                 unsigned x;
 633
 634                 desc = ext2_get_group_desc (sb, i, NULL);
 635                 if (!desc)
 636                         continue;
 637                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 638                 brelse(bitmap_bh);
 639                 bitmap_bh = read_inode_bitmap(sb, i);
 640                 if (!bitmap_bh)
 641                         continue;
 642
 643                 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
 644                 printk("group %d: stored = %d, counted = %u\n",
 645                         i, le16_to_cpu(desc->bg_free_inodes_count), x);
 646                 bitmap_count += x;
 647         }
 648         brelse(bitmap_bh);
 649         printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
 650                 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
 651                 desc_count, bitmap_count);
 652         return desc_count;
 653 #else
 654         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 655                 desc = ext2_get_group_desc (sb, i, NULL);
 656                 if (!desc)
 657                         continue;
 658                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 659         }
 660         return desc_count;
 661 #endif
 662 }
 663
 664 /* Called at mount-time, super-block is locked */
 665 unsigned long ext2_count_dirs (struct super_block * sb)
 666 {
 667         unsigned long count = 0;
 668         int i;
 669
 670         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 671                 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
 672                 if (!gdp)
 673                         continue;
 674                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 675         }
 676         return count;
 677 }
 678