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         desc->bg_free_inodes_count =
  79                 cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1);
  80         if (dir)
  81                 desc->bg_used_dirs_count =
  82                         cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1);
  83         spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
  84         if (dir)
  85                 percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
  86         sb->s_dirt = 1;
  87         mark_buffer_dirty(bh);
  88 }
  89
  90 /*
  91  * NOTE! When we get the inode, we're the only people
  92  * that have access to it, and as such there are no
  93  * race conditions we have to worry about. The inode
  94  * is not on the hash-lists, and it cannot be reached
  95  * through the filesystem because the directory entry
  96  * has been deleted earlier.
  97  *
  98  * HOWEVER: we must make sure that we get no aliases,
  99  * which means that we have to call "clear_inode()"
 100  * _before_ we mark the inode not in use in the inode
 101  * bitmaps. Otherwise a newly created file might use
 102  * the same inode number (not actually the same pointer
 103  * though), and then we'd have two inodes sharing the
 104  * same inode number and space on the harddisk.
 105  */
 106 void ext2_free_inode (struct inode * inode)
 107 {
 108         struct super_block * sb = inode->i_sb;
 109         int is_directory;
 110         unsigned long ino;
 111         struct buffer_head *bitmap_bh = NULL;
 112         unsigned long block_group;
 113         unsigned long bit;
 114         struct ext2_super_block * es;
 115
 116         ino = inode->i_ino;
 117         ext2_debug ("freeing inode %lu\n", ino);
 118
 119         /*
 120          * Note: we must free any quota before locking the superblock,
 121          * as writing the quota to disk may need the lock as well.
 122          */
 123         if (!is_bad_inode(inode)) {
 124                 /* Quota is already initialized in iput() */
 125                 ext2_xattr_delete_inode(inode);
 126                 DQUOT_FREE_INODE(inode);
 127                 DQUOT_DROP(inode);
 128         }
 129
 130         es = EXT2_SB(sb)->s_es;
 131         is_directory = S_ISDIR(inode->i_mode);
 132
 133         /* Do this BEFORE marking the inode not in use or returning an error */
 134         clear_inode (inode);
 135
 136         if (ino < EXT2_FIRST_INO(sb) ||
 137             ino > le32_to_cpu(es->s_inodes_count)) {
 138                 ext2_error (sb, "ext2_free_inode",
 139                             "reserved or nonexistent inode %lu", ino);
 140                 goto error_return;
 141         }
 142         block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
 143         bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
 144         brelse(bitmap_bh);
 145         bitmap_bh = read_inode_bitmap(sb, block_group);
 146         if (!bitmap_bh)
 147                 goto error_return;
 148
 149         /* Ok, now we can actually update the inode bitmaps.. */
 150         if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
 151                                 bit, (void *) bitmap_bh->b_data))
 152                 ext2_error (sb, "ext2_free_inode",
 153                               "bit already cleared for inode %lu", ino);
 154         else
 155                 ext2_release_inode(sb, block_group, is_directory);
 156         mark_buffer_dirty(bitmap_bh);
 157         if (sb->s_flags & MS_SYNCHRONOUS)
 158                 sync_dirty_buffer(bitmap_bh);
 159 error_return:
 160         brelse(bitmap_bh);
 161 }
 162
 163 /*
 164  * We perform asynchronous prereading of the new inode's inode block when
 165  * we create the inode, in the expectation that the inode will be written
 166  * back soon.  There are two reasons:
 167  *
 168  * - When creating a large number of files, the async prereads will be
 169  *   nicely merged into large reads
 170  * - When writing out a large number of inodes, we don't need to keep on
 171  *   stalling the writes while we read the inode block.
 172  *
 173  * FIXME: ext2_get_group_desc() needs to be simplified.
 174  */
 175 static void ext2_preread_inode(struct inode *inode)
 176 {
 177         unsigned long block_group;
 178         unsigned long offset;
 179         unsigned long block;
 180         struct ext2_group_desc * gdp;
 181         struct backing_dev_info *bdi;
 182
 183         bdi = inode->i_mapping->backing_dev_info;
 184         if (bdi_read_congested(bdi))
 185                 return;
 186         if (bdi_write_congested(bdi))
 187                 return;
 188
 189         block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 190         gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
 191         if (gdp == NULL)
 192                 return;
 193
 194         /*
 195          * Figure out the offset within the block group inode table
 196          */
 197         offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
 198                                 EXT2_INODE_SIZE(inode->i_sb);
 199         block = le32_to_cpu(gdp->bg_inode_table) +
 200                                 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
 201         sb_breadahead(inode->i_sb, block);
 202 }
 203
 204 /*
 205  * There are two policies for allocating an inode.  If the new inode is
 206  * a directory, then a forward search is made for a block group with both
 207  * free space and a low directory-to-inode ratio; if that fails, then of
 208  * the groups with above-average free space, that group with the fewest
 209  * directories already is chosen.
 210  *
 211  * For other inodes, search forward from the parent directory\'s block
 212  * group to find a free inode.
 213  */
 214 static int find_group_dir(struct super_block *sb, struct inode *parent)
 215 {
 216         int ngroups = EXT2_SB(sb)->s_groups_count;
 217         int avefreei = ext2_count_free_inodes(sb) / ngroups;
 218         struct ext2_group_desc *desc, *best_desc = NULL;
 219         int group, best_group = -1;
 220
 221         for (group = 0; group < ngroups; group++) {
 222                 desc = ext2_get_group_desc (sb, group, NULL);
 223                 if (!desc || !desc->bg_free_inodes_count)
 224                         continue;
 225                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 226                         continue;
 227                 if (!best_desc ||
 228                     (le16_to_cpu(desc->bg_free_blocks_count) >
 229                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 230                         best_group = group;
 231                         best_desc = desc;
 232                 }
 233         }
 234         if (!best_desc)
 235                 return -1;
 236
 237         return best_group;
 238 }
 239
 240 /*
 241  * Orlov's allocator for directories.
 242  *
 243  * We always try to spread first-level directories.
 244  *
 245  * If there are blockgroups with both free inodes and free blocks counts
 246  * not worse than average we return one with smallest directory count.
 247  * Otherwise we simply return a random group.
 248  *
 249  * For the rest rules look so:
 250  *
 251  * It's OK to put directory into a group unless
 252  * it has too many directories already (max_dirs) or
 253  * it has too few free inodes left (min_inodes) or
 254  * it has too few free blocks left (min_blocks) or
 255  * it's already running too large debt (max_debt).
 256  * Parent's group is preferred, if it doesn't satisfy these
 257  * conditions we search cyclically through the rest. If none
 258  * of the groups look good we just look for a group with more
 259  * free inodes than average (starting at parent's group).
 260  *
 261  * Debt is incremented each time we allocate a directory and decremented
 262  * when we allocate an inode, within 0--255.
 263  */
 264
 265 #define INODE_COST 64
 266 #define BLOCK_COST 256
 267
 268 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 269 {
 270         int parent_group = EXT2_I(parent)->i_block_group;
 271         struct ext2_sb_info *sbi = EXT2_SB(sb);
 272         struct ext2_super_block *es = sbi->s_es;
 273         int ngroups = sbi->s_groups_count;
 274         int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
 275         int freei;
 276         int avefreei;
 277         int free_blocks;
 278         int avefreeb;
 279         int blocks_per_dir;
 280         int ndirs;
 281         int max_debt, max_dirs, min_blocks, min_inodes;
 282         int group = -1, i;
 283         struct ext2_group_desc *desc;
 284
 285         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 286         avefreei = freei / ngroups;
 287         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 288         avefreeb = free_blocks / ngroups;
 289         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 290
 291         if ((parent == sb->s_root->d_inode) ||
 292             (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
 293                 struct ext2_group_desc *best_desc = NULL;
 294                 int best_ndir = inodes_per_group;
 295                 int best_group = -1;
 296
 297                 get_random_bytes(&group, sizeof(group));
 298                 parent_group = (unsigned)group % ngroups;
 299                 for (i = 0; i < ngroups; i++) {
 300                         group = (parent_group + i) % ngroups;
 301                         desc = ext2_get_group_desc (sb, group, NULL);
 302                         if (!desc || !desc->bg_free_inodes_count)
 303                                 continue;
 304                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 305                                 continue;
 306                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 307                                 continue;
 308                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 309                                 continue;
 310                         best_group = group;
 311                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 312                         best_desc = desc;
 313                 }
 314                 if (best_group >= 0) {
 315                         desc = best_desc;
 316                         group = best_group;
 317                         goto found;
 318                 }
 319                 goto fallback;
 320         }
 321
 322         if (ndirs == 0)
 323                 ndirs = 1;      /* percpu_counters are approximate... */
 324
 325         blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
 326
 327         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 328         min_inodes = avefreei - inodes_per_group / 4;
 329         min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
 330
 331         max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
 332         if (max_debt * INODE_COST > inodes_per_group)
 333                 max_debt = inodes_per_group / INODE_COST;
 334         if (max_debt > 255)
 335                 max_debt = 255;
 336         if (max_debt == 0)
 337                 max_debt = 1;
 338
 339         for (i = 0; i < ngroups; i++) {
 340                 group = (parent_group + i) % ngroups;
 341                 desc = ext2_get_group_desc (sb, group, NULL);
 342                 if (!desc || !desc->bg_free_inodes_count)
 343                         continue;
 344                 if (sbi->s_debts[group] >= max_debt)
 345                         continue;
 346                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 347                         continue;
 348                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 349                         continue;
 350                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 351                         continue;
 352                 goto found;
 353         }
 354
 355 fallback:
 356         for (i = 0; i < ngroups; i++) {
 357                 group = (parent_group + i) % ngroups;
 358                 desc = ext2_get_group_desc (sb, group, NULL);
 359                 if (!desc || !desc->bg_free_inodes_count)
 360                         continue;
 361                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 362                         goto found;
 363         }
 364
 365         if (avefreei) {
 366                 /*
 367                  * The free-inodes counter is approximate, and for really small
 368                  * filesystems the above test can fail to find any blockgroups
 369                  */
 370                 avefreei = 0;
 371                 goto fallback;
 372         }
 373
 374         return -1;
 375
 376 found:
 377         return group;
 378 }
 379
 380 static int find_group_other(struct super_block *sb, struct inode *parent)
 381 {
 382         int parent_group = EXT2_I(parent)->i_block_group;
 383         int ngroups = EXT2_SB(sb)->s_groups_count;
 384         struct ext2_group_desc *desc;
 385         int group, i;
 386
 387         /*
 388          * Try to place the inode in its parent directory
 389          */
 390         group = parent_group;
 391         desc = ext2_get_group_desc (sb, group, NULL);
 392         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 393                         le16_to_cpu(desc->bg_free_blocks_count))
 394                 goto found;
 395
 396         /*
 397          * We're going to place this inode in a different blockgroup from its
 398          * parent.  We want to cause files in a common directory to all land in
 399          * the same blockgroup.  But we want files which are in a different
 400          * directory which shares a blockgroup with our parent to land in a
 401          * different blockgroup.
 402          *
 403          * So add our directory's i_ino into the starting point for the hash.
 404          */
 405         group = (group + parent->i_ino) % ngroups;
 406
 407         /*
 408          * Use a quadratic hash to find a group with a free inode and some
 409          * free blocks.
 410          */
 411         for (i = 1; i < ngroups; i <<= 1) {
 412                 group += i;
 413                 if (group >= ngroups)
 414                         group -= ngroups;
 415                 desc = ext2_get_group_desc (sb, group, NULL);
 416                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 417                                 le16_to_cpu(desc->bg_free_blocks_count))
 418                         goto found;
 419         }
 420
 421         /*
 422          * That failed: try linear search for a free inode, even if that group
 423          * has no free blocks.
 424          */
 425         group = parent_group;
 426         for (i = 0; i < ngroups; i++) {
 427                 if (++group >= ngroups)
 428                         group = 0;
 429                 desc = ext2_get_group_desc (sb, group, NULL);
 430                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 431                         goto found;
 432         }
 433
 434         return -1;
 435
 436 found:
 437         return group;
 438 }
 439
 440 struct inode *ext2_new_inode(struct inode *dir, int mode)
 441 {
 442         struct super_block *sb;
 443         struct buffer_head *bitmap_bh = NULL;
 444         struct buffer_head *bh2;
 445         int group, i;
 446         ino_t ino = 0;
 447         struct inode * inode;
 448         struct ext2_group_desc *gdp;
 449         struct ext2_super_block *es;
 450         struct ext2_inode_info *ei;
 451         struct ext2_sb_info *sbi;
 452         int err;
 453
 454         sb = dir->i_sb;
 455         inode = new_inode(sb);
 456         if (!inode)
 457                 return ERR_PTR(-ENOMEM);
 458
 459         ei = EXT2_I(inode);
 460         sbi = EXT2_SB(sb);
 461         es = sbi->s_es;
 462         if (S_ISDIR(mode)) {
 463                 if (test_opt(sb, OLDALLOC))
 464                         group = find_group_dir(sb, dir);
 465                 else
 466                         group = find_group_orlov(sb, dir);
 467         } else
 468                 group = find_group_other(sb, dir);
 469
 470         if (group == -1) {
 471                 err = -ENOSPC;
 472                 goto fail;
 473         }
 474
 475         for (i = 0; i < sbi->s_groups_count; i++) {
 476                 gdp = ext2_get_group_desc(sb, group, &bh2);
 477                 brelse(bitmap_bh);
 478                 bitmap_bh = read_inode_bitmap(sb, group);
 479                 if (!bitmap_bh) {
 480                         err = -EIO;
 481                         goto fail;
 482                 }
 483                 ino = 0;
 484
 485 repeat_in_this_group:
 486                 ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
 487                                               EXT2_INODES_PER_GROUP(sb), ino);
 488                 if (ino >= EXT2_INODES_PER_GROUP(sb)) {
 489                         /*
 490                          * Rare race: find_group_xx() decided that there were
 491                          * free inodes in this group, but by the time we tried
 492                          * to allocate one, they're all gone.  This can also
 493                          * occur because the counters which find_group_orlov()
 494                          * uses are approximate.  So just go and search the
 495                          * next block group.
 496                          */
 497                         if (++group == sbi->s_groups_count)
 498                                 group = 0;
 499                         continue;
 500                 }
 501                 if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
 502                                                 ino, bitmap_bh->b_data)) {
 503                         /* we lost this inode */
 504                         if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
 505                                 /* this group is exhausted, try next group */
 506                                 if (++group == sbi->s_groups_count)
 507                                         group = 0;
 508                                 continue;
 509                         }
 510                         /* try to find free inode in the same group */
 511                         goto repeat_in_this_group;
 512                 }
 513                 goto got;
 514         }
 515
 516         /*
 517          * Scanned all blockgroups.
 518          */
 519         err = -ENOSPC;
 520         goto fail;
 521 got:
 522         mark_buffer_dirty(bitmap_bh);
 523         if (sb->s_flags & MS_SYNCHRONOUS)
 524                 sync_dirty_buffer(bitmap_bh);
 525         brelse(bitmap_bh);
 526
 527         ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
 528         if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 529                 ext2_error (sb, "ext2_new_inode",
 530                             "reserved inode or inode > inodes count - "
 531                             "block_group = %d,inode=%lu", group,
 532                             (unsigned long) ino);
 533                 err = -EIO;
 534                 goto fail;
 535         }
 536
 537         percpu_counter_add(&sbi->s_freeinodes_counter, -1);
 538         if (S_ISDIR(mode))
 539                 percpu_counter_inc(&sbi->s_dirs_counter);
 540
 541         spin_lock(sb_bgl_lock(sbi, group));
 542         gdp->bg_free_inodes_count =
 543                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
 544         if (S_ISDIR(mode)) {
 545                 if (sbi->s_debts[group] < 255)
 546                         sbi->s_debts[group]++;
 547                 gdp->bg_used_dirs_count =
 548                         cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
 549         } else {
 550                 if (sbi->s_debts[group])
 551                         sbi->s_debts[group]--;
 552         }
 553         spin_unlock(sb_bgl_lock(sbi, group));
 554
 555         sb->s_dirt = 1;
 556         mark_buffer_dirty(bh2);
 557         inode->i_uid = current->fsuid;
 558         if (test_opt (sb, GRPID))
 559                 inode->i_gid = dir->i_gid;
 560         else if (dir->i_mode & S_ISGID) {
 561                 inode->i_gid = dir->i_gid;
 562                 if (S_ISDIR(mode))
 563                         mode |= S_ISGID;
 564         } else
 565                 inode->i_gid = current->fsgid;
 566         inode->i_mode = mode;
 567
 568         inode->i_ino = ino;
 569         inode->i_blocks = 0;
 570         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 571         memset(ei->i_data, 0, sizeof(ei->i_data));
 572         ei->i_flags = EXT2_I(dir)->i_flags & ~EXT2_BTREE_FL;
 573         if (S_ISLNK(mode))
 574                 ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL);
 575         /* dirsync is only applied to directories */
 576         if (!S_ISDIR(mode))
 577                 ei->i_flags &= ~EXT2_DIRSYNC_FL;
 578         ei->i_faddr = 0;
 579         ei->i_frag_no = 0;
 580         ei->i_frag_size = 0;
 581         ei->i_file_acl = 0;
 582         ei->i_dir_acl = 0;
 583         ei->i_dtime = 0;
 584         ei->i_block_alloc_info = NULL;
 585         ei->i_block_group = group;
 586         ei->i_dir_start_lookup = 0;
 587         ei->i_state = EXT2_STATE_NEW;
 588         ext2_set_inode_flags(inode);
 589         spin_lock(&sbi->s_next_gen_lock);
 590         inode->i_generation = sbi->s_next_generation++;
 591         spin_unlock(&sbi->s_next_gen_lock);
 592         insert_inode_hash(inode);
 593
 594         if (DQUOT_ALLOC_INODE(inode)) {
 595                 err = -EDQUOT;
 596                 goto fail_drop;
 597         }
 598
 599         err = ext2_init_acl(inode, dir);
 600         if (err)
 601                 goto fail_free_drop;
 602
 603         err = ext2_init_security(inode,dir);
 604         if (err)
 605                 goto fail_free_drop;
 606
 607         mark_inode_dirty(inode);
 608         ext2_debug("allocating inode %lu\n", inode->i_ino);
 609         ext2_preread_inode(inode);
 610         return inode;
 611
 612 fail_free_drop:
 613         DQUOT_FREE_INODE(inode);
 614
 615 fail_drop:
 616         DQUOT_DROP(inode);
 617         inode->i_flags |= S_NOQUOTA;
 618         inode->i_nlink = 0;
 619         iput(inode);
 620         return ERR_PTR(err);
 621
 622 fail:
 623         make_bad_inode(inode);
 624         iput(inode);
 625         return ERR_PTR(err);
 626 }
 627
 628 unsigned long ext2_count_free_inodes (struct super_block * sb)
 629 {
 630         struct ext2_group_desc *desc;
 631         unsigned long desc_count = 0;
 632         int i;
 633
 634 #ifdef EXT2FS_DEBUG
 635         struct ext2_super_block *es;
 636         unsigned long bitmap_count = 0;
 637         struct buffer_head *bitmap_bh = NULL;
 638
 639         es = EXT2_SB(sb)->s_es;
 640         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 641                 unsigned x;
 642
 643                 desc = ext2_get_group_desc (sb, i, NULL);
 644                 if (!desc)
 645                         continue;
 646                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 647                 brelse(bitmap_bh);
 648                 bitmap_bh = read_inode_bitmap(sb, i);
 649                 if (!bitmap_bh)
 650                         continue;
 651
 652                 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
 653                 printk("group %d: stored = %d, counted = %u\n",
 654                         i, le16_to_cpu(desc->bg_free_inodes_count), x);
 655                 bitmap_count += x;
 656         }
 657         brelse(bitmap_bh);
 658         printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
 659                 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
 660                 desc_count, bitmap_count);
 661         return desc_count;
 662 #else
 663         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 664                 desc = ext2_get_group_desc (sb, i, NULL);
 665                 if (!desc)
 666                         continue;
 667                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 668         }
 669         return desc_count;
 670 #endif
 671 }
 672
 673 /* Called at mount-time, super-block is locked */
 674 unsigned long ext2_count_dirs (struct super_block * sb)
 675 {
 676         unsigned long count = 0;
 677         int i;
 678
 679         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 680                 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
 681                 if (!gdp)
 682                         continue;
 683                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 684         }
 685         return count;
 686 }
 687