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 buffer_head *bh;
 181         struct ext2_group_desc * gdp;
 182         struct backing_dev_info *bdi;
 183
 184         bdi = inode->i_mapping->backing_dev_info;
 185         if (bdi_read_congested(bdi))
 186                 return;
 187         if (bdi_write_congested(bdi))
 188                 return;
 189
 190         block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
 191         gdp = ext2_get_group_desc(inode->i_sb, block_group, &bh);
 192         if (gdp == NULL)
 193                 return;
 194
 195         /*
 196          * Figure out the offset within the block group inode table
 197          */
 198         offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
 199                                 EXT2_INODE_SIZE(inode->i_sb);
 200         block = le32_to_cpu(gdp->bg_inode_table) +
 201                                 (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
 202         sb_breadahead(inode->i_sb, block);
 203 }
 204
 205 /*
 206  * There are two policies for allocating an inode.  If the new inode is
 207  * a directory, then a forward search is made for a block group with both
 208  * free space and a low directory-to-inode ratio; if that fails, then of
 209  * the groups with above-average free space, that group with the fewest
 210  * directories already is chosen.
 211  *
 212  * For other inodes, search forward from the parent directory\'s block
 213  * group to find a free inode.
 214  */
 215 static int find_group_dir(struct super_block *sb, struct inode *parent)
 216 {
 217         int ngroups = EXT2_SB(sb)->s_groups_count;
 218         int avefreei = ext2_count_free_inodes(sb) / ngroups;
 219         struct ext2_group_desc *desc, *best_desc = NULL;
 220         struct buffer_head *bh, *best_bh = NULL;
 221         int group, best_group = -1;
 222
 223         for (group = 0; group < ngroups; group++) {
 224                 desc = ext2_get_group_desc (sb, group, &bh);
 225                 if (!desc || !desc->bg_free_inodes_count)
 226                         continue;
 227                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 228                         continue;
 229                 if (!best_desc ||
 230                     (le16_to_cpu(desc->bg_free_blocks_count) >
 231                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 232                         best_group = group;
 233                         best_desc = desc;
 234                         best_bh = bh;
 235                 }
 236         }
 237         if (!best_desc)
 238                 return -1;
 239
 240         return best_group;
 241 }
 242
 243 /*
 244  * Orlov's allocator for directories.
 245  *
 246  * We always try to spread first-level directories.
 247  *
 248  * If there are blockgroups with both free inodes and free blocks counts
 249  * not worse than average we return one with smallest directory count.
 250  * Otherwise we simply return a random group.
 251  *
 252  * For the rest rules look so:
 253  *
 254  * It's OK to put directory into a group unless
 255  * it has too many directories already (max_dirs) or
 256  * it has too few free inodes left (min_inodes) or
 257  * it has too few free blocks left (min_blocks) or
 258  * it's already running too large debt (max_debt).
 259  * Parent's group is prefered, if it doesn't satisfy these
 260  * conditions we search cyclically through the rest. If none
 261  * of the groups look good we just look for a group with more
 262  * free inodes than average (starting at parent's group).
 263  *
 264  * Debt is incremented each time we allocate a directory and decremented
 265  * when we allocate an inode, within 0--255.
 266  */
 267
 268 #define INODE_COST 64
 269 #define BLOCK_COST 256
 270
 271 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 272 {
 273         int parent_group = EXT2_I(parent)->i_block_group;
 274         struct ext2_sb_info *sbi = EXT2_SB(sb);
 275         struct ext2_super_block *es = sbi->s_es;
 276         int ngroups = sbi->s_groups_count;
 277         int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
 278         int freei;
 279         int avefreei;
 280         int free_blocks;
 281         int avefreeb;
 282         int blocks_per_dir;
 283         int ndirs;
 284         int max_debt, max_dirs, min_blocks, min_inodes;
 285         int group = -1, i;
 286         struct ext2_group_desc *desc;
 287         struct buffer_head *bh;
 288
 289         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 290         avefreei = freei / ngroups;
 291         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 292         avefreeb = free_blocks / ngroups;
 293         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 294
 295         if ((parent == sb->s_root->d_inode) ||
 296             (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
 297                 struct ext2_group_desc *best_desc = NULL;
 298                 struct buffer_head *best_bh = NULL;
 299                 int best_ndir = inodes_per_group;
 300                 int best_group = -1;
 301
 302                 get_random_bytes(&group, sizeof(group));
 303                 parent_group = (unsigned)group % ngroups;
 304                 for (i = 0; i < ngroups; i++) {
 305                         group = (parent_group + i) % ngroups;
 306                         desc = ext2_get_group_desc (sb, group, &bh);
 307                         if (!desc || !desc->bg_free_inodes_count)
 308                                 continue;
 309                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 310                                 continue;
 311                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 312                                 continue;
 313                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 314                                 continue;
 315                         best_group = group;
 316                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 317                         best_desc = desc;
 318                         best_bh = bh;
 319                 }
 320                 if (best_group >= 0) {
 321                         desc = best_desc;
 322                         bh = best_bh;
 323                         group = best_group;
 324                         goto found;
 325                 }
 326                 goto fallback;
 327         }
 328
 329         if (ndirs == 0)
 330                 ndirs = 1;      /* percpu_counters are approximate... */
 331
 332         blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
 333
 334         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 335         min_inodes = avefreei - inodes_per_group / 4;
 336         min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
 337
 338         max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
 339         if (max_debt * INODE_COST > inodes_per_group)
 340                 max_debt = inodes_per_group / INODE_COST;
 341         if (max_debt > 255)
 342                 max_debt = 255;
 343         if (max_debt == 0)
 344                 max_debt = 1;
 345
 346         for (i = 0; i < ngroups; i++) {
 347                 group = (parent_group + i) % ngroups;
 348                 desc = ext2_get_group_desc (sb, group, &bh);
 349                 if (!desc || !desc->bg_free_inodes_count)
 350                         continue;
 351                 if (sbi->s_debts[group] >= max_debt)
 352                         continue;
 353                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 354                         continue;
 355                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 356                         continue;
 357                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 358                         continue;
 359                 goto found;
 360         }
 361
 362 fallback:
 363         for (i = 0; i < ngroups; i++) {
 364                 group = (parent_group + i) % ngroups;
 365                 desc = ext2_get_group_desc (sb, group, &bh);
 366                 if (!desc || !desc->bg_free_inodes_count)
 367                         continue;
 368                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 369                         goto found;
 370         }
 371
 372         if (avefreei) {
 373                 /*
 374                  * The free-inodes counter is approximate, and for really small
 375                  * filesystems the above test can fail to find any blockgroups
 376                  */
 377                 avefreei = 0;
 378                 goto fallback;
 379         }
 380
 381         return -1;
 382
 383 found:
 384         return group;
 385 }
 386
 387 static int find_group_other(struct super_block *sb, struct inode *parent)
 388 {
 389         int parent_group = EXT2_I(parent)->i_block_group;
 390         int ngroups = EXT2_SB(sb)->s_groups_count;
 391         struct ext2_group_desc *desc;
 392         struct buffer_head *bh;
 393         int group, i;
 394
 395         /*
 396          * Try to place the inode in its parent directory
 397          */
 398         group = parent_group;
 399         desc = ext2_get_group_desc (sb, group, &bh);
 400         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 401                         le16_to_cpu(desc->bg_free_blocks_count))
 402                 goto found;
 403
 404         /*
 405          * We're going to place this inode in a different blockgroup from its
 406          * parent.  We want to cause files in a common directory to all land in
 407          * the same blockgroup.  But we want files which are in a different
 408          * directory which shares a blockgroup with our parent to land in a
 409          * different blockgroup.
 410          *
 411          * So add our directory's i_ino into the starting point for the hash.
 412          */
 413         group = (group + parent->i_ino) % ngroups;
 414
 415         /*
 416          * Use a quadratic hash to find a group with a free inode and some
 417          * free blocks.
 418          */
 419         for (i = 1; i < ngroups; i <<= 1) {
 420                 group += i;
 421                 if (group >= ngroups)
 422                         group -= ngroups;
 423                 desc = ext2_get_group_desc (sb, group, &bh);
 424                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 425                                 le16_to_cpu(desc->bg_free_blocks_count))
 426                         goto found;
 427         }
 428
 429         /*
 430          * That failed: try linear search for a free inode, even if that group
 431          * has no free blocks.
 432          */
 433         group = parent_group;
 434         for (i = 0; i < ngroups; i++) {
 435                 if (++group >= ngroups)
 436                         group = 0;
 437                 desc = ext2_get_group_desc (sb, group, &bh);
 438                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 439                         goto found;
 440         }
 441
 442         return -1;
 443
 444 found:
 445         return group;
 446 }
 447
 448 struct inode *ext2_new_inode(struct inode *dir, int mode)
 449 {
 450         struct super_block *sb;
 451         struct buffer_head *bitmap_bh = NULL;
 452         struct buffer_head *bh2;
 453         int group, i;
 454         ino_t ino = 0;
 455         struct inode * inode;
 456         struct ext2_group_desc *gdp;
 457         struct ext2_super_block *es;
 458         struct ext2_inode_info *ei;
 459         struct ext2_sb_info *sbi;
 460         int err;
 461
 462         sb = dir->i_sb;
 463         inode = new_inode(sb);
 464         if (!inode)
 465                 return ERR_PTR(-ENOMEM);
 466
 467         ei = EXT2_I(inode);
 468         sbi = EXT2_SB(sb);
 469         es = sbi->s_es;
 470         if (S_ISDIR(mode)) {
 471                 if (test_opt(sb, OLDALLOC))
 472                         group = find_group_dir(sb, dir);
 473                 else
 474                         group = find_group_orlov(sb, dir);
 475         } else
 476                 group = find_group_other(sb, dir);
 477
 478         if (group == -1) {
 479                 err = -ENOSPC;
 480                 goto fail;
 481         }
 482
 483         for (i = 0; i < sbi->s_groups_count; i++) {
 484                 gdp = ext2_get_group_desc(sb, group, &bh2);
 485                 brelse(bitmap_bh);
 486                 bitmap_bh = read_inode_bitmap(sb, group);
 487                 if (!bitmap_bh) {
 488                         err = -EIO;
 489                         goto fail;
 490                 }
 491                 ino = 0;
 492
 493 repeat_in_this_group:
 494                 ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
 495                                               EXT2_INODES_PER_GROUP(sb), ino);
 496                 if (ino >= EXT2_INODES_PER_GROUP(sb)) {
 497                         /*
 498                          * Rare race: find_group_xx() decided that there were
 499                          * free inodes in this group, but by the time we tried
 500                          * to allocate one, they're all gone.  This can also
 501                          * occur because the counters which find_group_orlov()
 502                          * uses are approximate.  So just go and search the
 503                          * next block group.
 504                          */
 505                         if (++group == sbi->s_groups_count)
 506                                 group = 0;
 507                         continue;
 508                 }
 509                 if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
 510                                                 ino, bitmap_bh->b_data)) {
 511                         /* we lost this inode */
 512                         if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
 513                                 /* this group is exhausted, try next group */
 514                                 if (++group == sbi->s_groups_count)
 515                                         group = 0;
 516                                 continue;
 517                         }
 518                         /* try to find free inode in the same group */
 519                         goto repeat_in_this_group;
 520                 }
 521                 goto got;
 522         }
 523
 524         /*
 525          * Scanned all blockgroups.
 526          */
 527         err = -ENOSPC;
 528         goto fail;
 529 got:
 530         mark_buffer_dirty(bitmap_bh);
 531         if (sb->s_flags & MS_SYNCHRONOUS)
 532                 sync_dirty_buffer(bitmap_bh);
 533         brelse(bitmap_bh);
 534
 535         ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
 536         if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 537                 ext2_error (sb, "ext2_new_inode",
 538                             "reserved inode or inode > inodes count - "
 539                             "block_group = %d,inode=%lu", group,
 540                             (unsigned long) ino);
 541                 err = -EIO;
 542                 goto fail;
 543         }
 544
 545         percpu_counter_mod(&sbi->s_freeinodes_counter, -1);
 546         if (S_ISDIR(mode))
 547                 percpu_counter_inc(&sbi->s_dirs_counter);
 548
 549         spin_lock(sb_bgl_lock(sbi, group));
 550         gdp->bg_free_inodes_count =
 551                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
 552         if (S_ISDIR(mode)) {
 553                 if (sbi->s_debts[group] < 255)
 554                         sbi->s_debts[group]++;
 555                 gdp->bg_used_dirs_count =
 556                         cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
 557         } else {
 558                 if (sbi->s_debts[group])
 559                         sbi->s_debts[group]--;
 560         }
 561         spin_unlock(sb_bgl_lock(sbi, group));
 562
 563         sb->s_dirt = 1;
 564         mark_buffer_dirty(bh2);
 565         inode->i_uid = current->fsuid;
 566         if (test_opt (sb, GRPID))
 567                 inode->i_gid = dir->i_gid;
 568         else if (dir->i_mode & S_ISGID) {
 569                 inode->i_gid = dir->i_gid;
 570                 if (S_ISDIR(mode))
 571                         mode |= S_ISGID;
 572         } else
 573                 inode->i_gid = current->fsgid;
 574         inode->i_mode = mode;
 575
 576         inode->i_ino = ino;
 577         inode->i_blocks = 0;
 578         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 579         memset(ei->i_data, 0, sizeof(ei->i_data));
 580         ei->i_flags = EXT2_I(dir)->i_flags & ~EXT2_BTREE_FL;
 581         if (S_ISLNK(mode))
 582                 ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL);
 583         /* dirsync is only applied to directories */
 584         if (!S_ISDIR(mode))
 585                 ei->i_flags &= ~EXT2_DIRSYNC_FL;
 586         ei->i_faddr = 0;
 587         ei->i_frag_no = 0;
 588         ei->i_frag_size = 0;
 589         ei->i_file_acl = 0;
 590         ei->i_dir_acl = 0;
 591         ei->i_dtime = 0;
 592         ei->i_block_group = group;
 593         ei->i_next_alloc_block = 0;
 594         ei->i_next_alloc_goal = 0;
 595         ei->i_prealloc_block = 0;
 596         ei->i_prealloc_count = 0;
 597         ei->i_dir_start_lookup = 0;
 598         ei->i_state = EXT2_STATE_NEW;
 599         ext2_set_inode_flags(inode);
 600         spin_lock(&sbi->s_next_gen_lock);
 601         inode->i_generation = sbi->s_next_generation++;
 602         spin_unlock(&sbi->s_next_gen_lock);
 603         insert_inode_hash(inode);
 604
 605         if (DQUOT_ALLOC_INODE(inode)) {
 606                 err = -EDQUOT;
 607                 goto fail_drop;
 608         }
 609
 610         err = ext2_init_acl(inode, dir);
 611         if (err)
 612                 goto fail_free_drop;
 613
 614         err = ext2_init_security(inode,dir);
 615         if (err)
 616                 goto fail_free_drop;
 617
 618         mark_inode_dirty(inode);
 619         ext2_debug("allocating inode %lu\n", inode->i_ino);
 620         ext2_preread_inode(inode);
 621         return inode;
 622
 623 fail_free_drop:
 624         DQUOT_FREE_INODE(inode);
 625
 626 fail_drop:
 627         DQUOT_DROP(inode);
 628         inode->i_flags |= S_NOQUOTA;
 629         inode->i_nlink = 0;
 630         iput(inode);
 631         return ERR_PTR(err);
 632
 633 fail:
 634         make_bad_inode(inode);
 635         iput(inode);
 636         return ERR_PTR(err);
 637 }
 638
 639 unsigned long ext2_count_free_inodes (struct super_block * sb)
 640 {
 641         struct ext2_group_desc *desc;
 642         unsigned long desc_count = 0;
 643         int i;
 644
 645 #ifdef EXT2FS_DEBUG
 646         struct ext2_super_block *es;
 647         unsigned long bitmap_count = 0;
 648         struct buffer_head *bitmap_bh = NULL;
 649
 650         es = EXT2_SB(sb)->s_es;
 651         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 652                 unsigned x;
 653
 654                 desc = ext2_get_group_desc (sb, i, NULL);
 655                 if (!desc)
 656                         continue;
 657                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 658                 brelse(bitmap_bh);
 659                 bitmap_bh = read_inode_bitmap(sb, i);
 660                 if (!bitmap_bh)
 661                         continue;
 662
 663                 x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
 664                 printk("group %d: stored = %d, counted = %u\n",
 665                         i, le16_to_cpu(desc->bg_free_inodes_count), x);
 666                 bitmap_count += x;
 667         }
 668         brelse(bitmap_bh);
 669         printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
 670                 percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
 671                 desc_count, bitmap_count);
 672         return desc_count;
 673 #else
 674         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 675                 desc = ext2_get_group_desc (sb, i, NULL);
 676                 if (!desc)
 677                         continue;
 678                 desc_count += le16_to_cpu(desc->bg_free_inodes_count);
 679         }
 680         return desc_count;
 681 #endif
 682 }
 683
 684 /* Called at mount-time, super-block is locked */
 685 unsigned long ext2_count_dirs (struct super_block * sb)
 686 {
 687         unsigned long count = 0;
 688         int i;
 689
 690         for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
 691                 struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
 692                 if (!gdp)
 693                         continue;
 694                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 695         }
 696         return count;
 697 }
 698