fs/ext3/ialloc.c

   1 /*
   2  *  linux/fs/ext3/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@redhat.com), 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/time.h>
  16 #include <linux/fs.h>
  17 #include <linux/jbd.h>
  18 #include <linux/ext3_fs.h>
  19 #include <linux/ext3_jbd.h>
  20 #include <linux/stat.h>
  21 #include <linux/string.h>
  22 #include <linux/quotaops.h>
  23 #include <linux/buffer_head.h>
  24 #include <linux/random.h>
  25 #include <linux/bitops.h>
  26
  27 #include <asm/byteorder.h>
  28
  29 #include "xattr.h"
  30 #include "acl.h"
  31
  32 /*
  33  * ialloc.c contains the inodes allocation and deallocation routines
  34  */
  35
  36 /*
  37  * The free inodes are managed by bitmaps.  A file system contains several
  38  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  39  * block for inodes, N blocks for the inode table and data blocks.
  40  *
  41  * The file system contains group descriptors which are located after the
  42  * super block.  Each descriptor contains the number of the bitmap block and
  43  * the free blocks count in the block.
  44  */
  45
  46
  47 /*
  48  * Read the inode allocation bitmap for a given block_group, reading
  49  * into the specified slot in the superblock's bitmap cache.
  50  *
  51  * Return buffer_head of bitmap on success or NULL.
  52  */
  53 static struct buffer_head *
  54 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
  55 {
  56         struct ext3_group_desc *desc;
  57         struct buffer_head *bh = NULL;
  58
  59         desc = ext3_get_group_desc(sb, block_group, NULL);
  60         if (!desc)
  61                 goto error_out;
  62
  63         bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
  64         if (!bh)
  65                 ext3_error(sb, "read_inode_bitmap",
  66                             "Cannot read inode bitmap - "
  67                             "block_group = %lu, inode_bitmap = %u",
  68                             block_group, le32_to_cpu(desc->bg_inode_bitmap));
  69 error_out:
  70         return bh;
  71 }
  72
  73 /*
  74  * NOTE! When we get the inode, we're the only people
  75  * that have access to it, and as such there are no
  76  * race conditions we have to worry about. The inode
  77  * is not on the hash-lists, and it cannot be reached
  78  * through the filesystem because the directory entry
  79  * has been deleted earlier.
  80  *
  81  * HOWEVER: we must make sure that we get no aliases,
  82  * which means that we have to call "clear_inode()"
  83  * _before_ we mark the inode not in use in the inode
  84  * bitmaps. Otherwise a newly created file might use
  85  * the same inode number (not actually the same pointer
  86  * though), and then we'd have two inodes sharing the
  87  * same inode number and space on the harddisk.
  88  */
  89 void ext3_free_inode (handle_t *handle, struct inode * inode)
  90 {
  91         struct super_block * sb = inode->i_sb;
  92         int is_directory;
  93         unsigned long ino;
  94         struct buffer_head *bitmap_bh = NULL;
  95         struct buffer_head *bh2;
  96         unsigned long block_group;
  97         unsigned long bit;
  98         struct ext3_group_desc * gdp;
  99         struct ext3_super_block * es;
 100         struct ext3_sb_info *sbi;
 101         int fatal = 0, err;
 102
 103         if (atomic_read(&inode->i_count) > 1) {
 104                 printk ("ext3_free_inode: inode has count=%d\n",
 105                                         atomic_read(&inode->i_count));
 106                 return;
 107         }
 108         if (inode->i_nlink) {
 109                 printk ("ext3_free_inode: inode has nlink=%d\n",
 110                         inode->i_nlink);
 111                 return;
 112         }
 113         if (!sb) {
 114                 printk("ext3_free_inode: inode on nonexistent device\n");
 115                 return;
 116         }
 117         sbi = EXT3_SB(sb);
 118
 119         ino = inode->i_ino;
 120         ext3_debug ("freeing inode %lu\n", ino);
 121
 122         /*
 123          * Note: we must free any quota before locking the superblock,
 124          * as writing the quota to disk may need the lock as well.
 125          */
 126         DQUOT_INIT(inode);
 127         ext3_xattr_delete_inode(handle, inode);
 128         DQUOT_FREE_INODE(inode);
 129         DQUOT_DROP(inode);
 130
 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         es = EXT3_SB(sb)->s_es;
 137         if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 138                 ext3_error (sb, "ext3_free_inode",
 139                             "reserved or nonexistent inode %lu", ino);
 140                 goto error_return;
 141         }
 142         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 143         bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 144         bitmap_bh = read_inode_bitmap(sb, block_group);
 145         if (!bitmap_bh)
 146                 goto error_return;
 147
 148         BUFFER_TRACE(bitmap_bh, "get_write_access");
 149         fatal = ext3_journal_get_write_access(handle, bitmap_bh);
 150         if (fatal)
 151                 goto error_return;
 152
 153         /* Ok, now we can actually update the inode bitmaps.. */
 154         if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 155                                         bit, bitmap_bh->b_data))
 156                 ext3_error (sb, "ext3_free_inode",
 157                               "bit already cleared for inode %lu", ino);
 158         else {
 159                 gdp = ext3_get_group_desc (sb, block_group, &bh2);
 160
 161                 BUFFER_TRACE(bh2, "get_write_access");
 162                 fatal = ext3_journal_get_write_access(handle, bh2);
 163                 if (fatal) goto error_return;
 164
 165                 if (gdp) {
 166                         spin_lock(sb_bgl_lock(sbi, block_group));
 167                         le16_add_cpu(&gdp->bg_free_inodes_count, 1);
 168                         if (is_directory)
 169                                 le16_add_cpu(&gdp->bg_used_dirs_count, -1);
 170                         spin_unlock(sb_bgl_lock(sbi, block_group));
 171                         percpu_counter_inc(&sbi->s_freeinodes_counter);
 172                         if (is_directory)
 173                                 percpu_counter_dec(&sbi->s_dirs_counter);
 174
 175                 }
 176                 BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 177                 err = ext3_journal_dirty_metadata(handle, bh2);
 178                 if (!fatal) fatal = err;
 179         }
 180         BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
 181         err = ext3_journal_dirty_metadata(handle, bitmap_bh);
 182         if (!fatal)
 183                 fatal = err;
 184         sb->s_dirt = 1;
 185 error_return:
 186         brelse(bitmap_bh);
 187         ext3_std_error(sb, fatal);
 188 }
 189
 190 /*
 191  * There are two policies for allocating an inode.  If the new inode is
 192  * a directory, then a forward search is made for a block group with both
 193  * free space and a low directory-to-inode ratio; if that fails, then of
 194  * the groups with above-average free space, that group with the fewest
 195  * directories already is chosen.
 196  *
 197  * For other inodes, search forward from the parent directory\'s block
 198  * group to find a free inode.
 199  */
 200 static int find_group_dir(struct super_block *sb, struct inode *parent)
 201 {
 202         int ngroups = EXT3_SB(sb)->s_groups_count;
 203         unsigned int freei, avefreei;
 204         struct ext3_group_desc *desc, *best_desc = NULL;
 205         int group, best_group = -1;
 206
 207         freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
 208         avefreei = freei / ngroups;
 209
 210         for (group = 0; group < ngroups; group++) {
 211                 desc = ext3_get_group_desc (sb, group, NULL);
 212                 if (!desc || !desc->bg_free_inodes_count)
 213                         continue;
 214                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 215                         continue;
 216                 if (!best_desc ||
 217                     (le16_to_cpu(desc->bg_free_blocks_count) >
 218                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 219                         best_group = group;
 220                         best_desc = desc;
 221                 }
 222         }
 223         return best_group;
 224 }
 225
 226 /*
 227  * Orlov's allocator for directories.
 228  *
 229  * We always try to spread first-level directories.
 230  *
 231  * If there are blockgroups with both free inodes and free blocks counts
 232  * not worse than average we return one with smallest directory count.
 233  * Otherwise we simply return a random group.
 234  *
 235  * For the rest rules look so:
 236  *
 237  * It's OK to put directory into a group unless
 238  * it has too many directories already (max_dirs) or
 239  * it has too few free inodes left (min_inodes) or
 240  * it has too few free blocks left (min_blocks) or
 241  * it's already running too large debt (max_debt).
 242  * Parent's group is preferred, if it doesn't satisfy these
 243  * conditions we search cyclically through the rest. If none
 244  * of the groups look good we just look for a group with more
 245  * free inodes than average (starting at parent's group).
 246  *
 247  * Debt is incremented each time we allocate a directory and decremented
 248  * when we allocate an inode, within 0--255.
 249  */
 250
 251 #define INODE_COST 64
 252 #define BLOCK_COST 256
 253
 254 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 255 {
 256         int parent_group = EXT3_I(parent)->i_block_group;
 257         struct ext3_sb_info *sbi = EXT3_SB(sb);
 258         struct ext3_super_block *es = sbi->s_es;
 259         int ngroups = sbi->s_groups_count;
 260         int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
 261         unsigned int freei, avefreei;
 262         ext3_fsblk_t freeb, avefreeb;
 263         ext3_fsblk_t blocks_per_dir;
 264         unsigned int ndirs;
 265         int max_debt, max_dirs, min_inodes;
 266         ext3_grpblk_t min_blocks;
 267         int group = -1, i;
 268         struct ext3_group_desc *desc;
 269
 270         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 271         avefreei = freei / ngroups;
 272         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 273         avefreeb = freeb / ngroups;
 274         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 275
 276         if ((parent == sb->s_root->d_inode) ||
 277             (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
 278                 int best_ndir = inodes_per_group;
 279                 int best_group = -1;
 280
 281                 get_random_bytes(&group, sizeof(group));
 282                 parent_group = (unsigned)group % ngroups;
 283                 for (i = 0; i < ngroups; i++) {
 284                         group = (parent_group + i) % ngroups;
 285                         desc = ext3_get_group_desc (sb, group, NULL);
 286                         if (!desc || !desc->bg_free_inodes_count)
 287                                 continue;
 288                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 289                                 continue;
 290                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 291                                 continue;
 292                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 293                                 continue;
 294                         best_group = group;
 295                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 296                 }
 297                 if (best_group >= 0)
 298                         return best_group;
 299                 goto fallback;
 300         }
 301
 302         blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
 303
 304         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 305         min_inodes = avefreei - inodes_per_group / 4;
 306         min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
 307
 308         max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, (ext3_fsblk_t)BLOCK_COST);
 309         if (max_debt * INODE_COST > inodes_per_group)
 310                 max_debt = inodes_per_group / INODE_COST;
 311         if (max_debt > 255)
 312                 max_debt = 255;
 313         if (max_debt == 0)
 314                 max_debt = 1;
 315
 316         for (i = 0; i < ngroups; i++) {
 317                 group = (parent_group + i) % ngroups;
 318                 desc = ext3_get_group_desc (sb, group, NULL);
 319                 if (!desc || !desc->bg_free_inodes_count)
 320                         continue;
 321                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 322                         continue;
 323                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 324                         continue;
 325                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 326                         continue;
 327                 return group;
 328         }
 329
 330 fallback:
 331         for (i = 0; i < ngroups; i++) {
 332                 group = (parent_group + i) % ngroups;
 333                 desc = ext3_get_group_desc (sb, group, NULL);
 334                 if (!desc || !desc->bg_free_inodes_count)
 335                         continue;
 336                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 337                         return group;
 338         }
 339
 340         if (avefreei) {
 341                 /*
 342                  * The free-inodes counter is approximate, and for really small
 343                  * filesystems the above test can fail to find any blockgroups
 344                  */
 345                 avefreei = 0;
 346                 goto fallback;
 347         }
 348
 349         return -1;
 350 }
 351
 352 static int find_group_other(struct super_block *sb, struct inode *parent)
 353 {
 354         int parent_group = EXT3_I(parent)->i_block_group;
 355         int ngroups = EXT3_SB(sb)->s_groups_count;
 356         struct ext3_group_desc *desc;
 357         int group, i;
 358
 359         /*
 360          * Try to place the inode in its parent directory
 361          */
 362         group = parent_group;
 363         desc = ext3_get_group_desc (sb, group, NULL);
 364         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 365                         le16_to_cpu(desc->bg_free_blocks_count))
 366                 return group;
 367
 368         /*
 369          * We're going to place this inode in a different blockgroup from its
 370          * parent.  We want to cause files in a common directory to all land in
 371          * the same blockgroup.  But we want files which are in a different
 372          * directory which shares a blockgroup with our parent to land in a
 373          * different blockgroup.
 374          *
 375          * So add our directory's i_ino into the starting point for the hash.
 376          */
 377         group = (group + parent->i_ino) % ngroups;
 378
 379         /*
 380          * Use a quadratic hash to find a group with a free inode and some free
 381          * blocks.
 382          */
 383         for (i = 1; i < ngroups; i <<= 1) {
 384                 group += i;
 385                 if (group >= ngroups)
 386                         group -= ngroups;
 387                 desc = ext3_get_group_desc (sb, group, NULL);
 388                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 389                                 le16_to_cpu(desc->bg_free_blocks_count))
 390                         return group;
 391         }
 392
 393         /*
 394          * That failed: try linear search for a free inode, even if that group
 395          * has no free blocks.
 396          */
 397         group = parent_group;
 398         for (i = 0; i < ngroups; i++) {
 399                 if (++group >= ngroups)
 400                         group = 0;
 401                 desc = ext3_get_group_desc (sb, group, NULL);
 402                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 403                         return group;
 404         }
 405
 406         return -1;
 407 }
 408
 409 /*
 410  * There are two policies for allocating an inode.  If the new inode is
 411  * a directory, then a forward search is made for a block group with both
 412  * free space and a low directory-to-inode ratio; if that fails, then of
 413  * the groups with above-average free space, that group with the fewest
 414  * directories already is chosen.
 415  *
 416  * For other inodes, search forward from the parent directory's block
 417  * group to find a free inode.
 418  */
 419 struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
 420 {
 421         struct super_block *sb;
 422         struct buffer_head *bitmap_bh = NULL;
 423         struct buffer_head *bh2;
 424         int group;
 425         unsigned long ino = 0;
 426         struct inode * inode;
 427         struct ext3_group_desc * gdp = NULL;
 428         struct ext3_super_block * es;
 429         struct ext3_inode_info *ei;
 430         struct ext3_sb_info *sbi;
 431         int err = 0;
 432         struct inode *ret;
 433         int i;
 434
 435         /* Cannot create files in a deleted directory */
 436         if (!dir || !dir->i_nlink)
 437                 return ERR_PTR(-EPERM);
 438
 439         sb = dir->i_sb;
 440         inode = new_inode(sb);
 441         if (!inode)
 442                 return ERR_PTR(-ENOMEM);
 443         ei = EXT3_I(inode);
 444
 445         sbi = EXT3_SB(sb);
 446         es = sbi->s_es;
 447         if (S_ISDIR(mode)) {
 448                 if (test_opt (sb, OLDALLOC))
 449                         group = find_group_dir(sb, dir);
 450                 else
 451                         group = find_group_orlov(sb, dir);
 452         } else
 453                 group = find_group_other(sb, dir);
 454
 455         err = -ENOSPC;
 456         if (group == -1)
 457                 goto out;
 458
 459         for (i = 0; i < sbi->s_groups_count; i++) {
 460                 err = -EIO;
 461
 462                 gdp = ext3_get_group_desc(sb, group, &bh2);
 463                 if (!gdp)
 464                         goto fail;
 465
 466                 brelse(bitmap_bh);
 467                 bitmap_bh = read_inode_bitmap(sb, group);
 468                 if (!bitmap_bh)
 469                         goto fail;
 470
 471                 ino = 0;
 472
 473 repeat_in_this_group:
 474                 ino = ext3_find_next_zero_bit((unsigned long *)
 475                                 bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
 476                 if (ino < EXT3_INODES_PER_GROUP(sb)) {
 477
 478                         BUFFER_TRACE(bitmap_bh, "get_write_access");
 479                         err = ext3_journal_get_write_access(handle, bitmap_bh);
 480                         if (err)
 481                                 goto fail;
 482
 483                         if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
 484                                                 ino, bitmap_bh->b_data)) {
 485                                 /* we won it */
 486                                 BUFFER_TRACE(bitmap_bh,
 487                                         "call ext3_journal_dirty_metadata");
 488                                 err = ext3_journal_dirty_metadata(handle,
 489                                                                 bitmap_bh);
 490                                 if (err)
 491                                         goto fail;
 492                                 goto got;
 493                         }
 494                         /* we lost it */
 495                         journal_release_buffer(handle, bitmap_bh);
 496
 497                         if (++ino < EXT3_INODES_PER_GROUP(sb))
 498                                 goto repeat_in_this_group;
 499                 }
 500
 501                 /*
 502                  * This case is possible in concurrent environment.  It is very
 503                  * rare.  We cannot repeat the find_group_xxx() call because
 504                  * that will simply return the same blockgroup, because the
 505                  * group descriptor metadata has not yet been updated.
 506                  * So we just go onto the next blockgroup.
 507                  */
 508                 if (++group == sbi->s_groups_count)
 509                         group = 0;
 510         }
 511         err = -ENOSPC;
 512         goto out;
 513
 514 got:
 515         ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
 516         if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 517                 ext3_error (sb, "ext3_new_inode",
 518                             "reserved inode or inode > inodes count - "
 519                             "block_group = %d, inode=%lu", group, ino);
 520                 err = -EIO;
 521                 goto fail;
 522         }
 523
 524         BUFFER_TRACE(bh2, "get_write_access");
 525         err = ext3_journal_get_write_access(handle, bh2);
 526         if (err) goto fail;
 527         spin_lock(sb_bgl_lock(sbi, group));
 528         le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 529         if (S_ISDIR(mode)) {
 530                 le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 531         }
 532         spin_unlock(sb_bgl_lock(sbi, group));
 533         BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 534         err = ext3_journal_dirty_metadata(handle, bh2);
 535         if (err) goto fail;
 536
 537         percpu_counter_dec(&sbi->s_freeinodes_counter);
 538         if (S_ISDIR(mode))
 539                 percpu_counter_inc(&sbi->s_dirs_counter);
 540         sb->s_dirt = 1;
 541
 542         inode->i_uid = current->fsuid;
 543         if (test_opt (sb, GRPID))
 544                 inode->i_gid = dir->i_gid;
 545         else if (dir->i_mode & S_ISGID) {
 546                 inode->i_gid = dir->i_gid;
 547                 if (S_ISDIR(mode))
 548                         mode |= S_ISGID;
 549         } else
 550                 inode->i_gid = current->fsgid;
 551         inode->i_mode = mode;
 552
 553         inode->i_ino = ino;
 554         /* This is the optimal IO size (for stat), not the fs block size */
 555         inode->i_blocks = 0;
 556         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 557
 558         memset(ei->i_data, 0, sizeof(ei->i_data));
 559         ei->i_dir_start_lookup = 0;
 560         ei->i_disksize = 0;
 561
 562         ei->i_flags = EXT3_I(dir)->i_flags & ~EXT3_INDEX_FL;
 563         if (S_ISLNK(mode))
 564                 ei->i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
 565         /* dirsync only applies to directories */
 566         if (!S_ISDIR(mode))
 567                 ei->i_flags &= ~EXT3_DIRSYNC_FL;
 568 #ifdef EXT3_FRAGMENTS
 569         ei->i_faddr = 0;
 570         ei->i_frag_no = 0;
 571         ei->i_frag_size = 0;
 572 #endif
 573         ei->i_file_acl = 0;
 574         ei->i_dir_acl = 0;
 575         ei->i_dtime = 0;
 576         ei->i_block_alloc_info = NULL;
 577         ei->i_block_group = group;
 578
 579         ext3_set_inode_flags(inode);
 580         if (IS_DIRSYNC(inode))
 581                 handle->h_sync = 1;
 582         insert_inode_hash(inode);
 583         spin_lock(&sbi->s_next_gen_lock);
 584         inode->i_generation = sbi->s_next_generation++;
 585         spin_unlock(&sbi->s_next_gen_lock);
 586
 587         ei->i_state = EXT3_STATE_NEW;
 588         ei->i_extra_isize =
 589                 (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) ?
 590                 sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE : 0;
 591
 592         ret = inode;
 593         if(DQUOT_ALLOC_INODE(inode)) {
 594                 err = -EDQUOT;
 595                 goto fail_drop;
 596         }
 597
 598         err = ext3_init_acl(handle, inode, dir);
 599         if (err)
 600                 goto fail_free_drop;
 601
 602         err = ext3_init_security(handle,inode, dir);
 603         if (err)
 604                 goto fail_free_drop;
 605
 606         err = ext3_mark_inode_dirty(handle, inode);
 607         if (err) {
 608                 ext3_std_error(sb, err);
 609                 goto fail_free_drop;
 610         }
 611
 612         ext3_debug("allocating inode %lu\n", inode->i_ino);
 613         goto really_out;
 614 fail:
 615         ext3_std_error(sb, err);
 616 out:
 617         iput(inode);
 618         ret = ERR_PTR(err);
 619 really_out:
 620         brelse(bitmap_bh);
 621         return ret;
 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         brelse(bitmap_bh);
 632         return ERR_PTR(err);
 633 }
 634
 635 /* Verify that we are loading a valid orphan from disk */
 636 struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
 637 {
 638         unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
 639         unsigned long block_group;
 640         int bit;
 641         struct buffer_head *bitmap_bh;
 642         struct inode *inode = NULL;
 643         long err = -EIO;
 644
 645         /* Error cases - e2fsck has already cleaned up for us */
 646         if (ino > max_ino) {
 647                 ext3_warning(sb, __func__,
 648                              "bad orphan ino %lu!  e2fsck was run?", ino);
 649                 goto error;
 650         }
 651
 652         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 653         bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 654         bitmap_bh = read_inode_bitmap(sb, block_group);
 655         if (!bitmap_bh) {
 656                 ext3_warning(sb, __func__,
 657                              "inode bitmap error for orphan %lu", ino);
 658                 goto error;
 659         }
 660
 661         /* Having the inode bit set should be a 100% indicator that this
 662          * is a valid orphan (no e2fsck run on fs).  Orphans also include
 663          * inodes that were being truncated, so we can't check i_nlink==0.
 664          */
 665         if (!ext3_test_bit(bit, bitmap_bh->b_data))
 666                 goto bad_orphan;
 667
 668         inode = ext3_iget(sb, ino);
 669         if (IS_ERR(inode))
 670                 goto iget_failed;
 671
 672         /*
 673          * If the orphans has i_nlinks > 0 then it should be able to be
 674          * truncated, otherwise it won't be removed from the orphan list
 675          * during processing and an infinite loop will result.
 676          */
 677         if (inode->i_nlink && !ext3_can_truncate(inode))
 678                 goto bad_orphan;
 679
 680         if (NEXT_ORPHAN(inode) > max_ino)
 681                 goto bad_orphan;
 682         brelse(bitmap_bh);
 683         return inode;
 684
 685 iget_failed:
 686         err = PTR_ERR(inode);
 687         inode = NULL;
 688 bad_orphan:
 689         ext3_warning(sb, __func__,
 690                      "bad orphan inode %lu!  e2fsck was run?", ino);
 691         printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
 692                bit, (unsigned long long)bitmap_bh->b_blocknr,
 693                ext3_test_bit(bit, bitmap_bh->b_data));
 694         printk(KERN_NOTICE "inode=%p\n", inode);
 695         if (inode) {
 696                 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 697                        is_bad_inode(inode));
 698                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 699                        NEXT_ORPHAN(inode));
 700                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 701                 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
 702                 /* Avoid freeing blocks if we got a bad deleted inode */
 703                 if (inode->i_nlink == 0)
 704                         inode->i_blocks = 0;
 705                 iput(inode);
 706         }
 707         brelse(bitmap_bh);
 708 error:
 709         return ERR_PTR(err);
 710 }
 711
 712 unsigned long ext3_count_free_inodes (struct super_block * sb)
 713 {
 714         unsigned long desc_count;
 715         struct ext3_group_desc *gdp;
 716         int i;
 717 #ifdef EXT3FS_DEBUG
 718         struct ext3_super_block *es;
 719         unsigned long bitmap_count, x;
 720         struct buffer_head *bitmap_bh = NULL;
 721
 722         es = EXT3_SB(sb)->s_es;
 723         desc_count = 0;
 724         bitmap_count = 0;
 725         gdp = NULL;
 726         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 727                 gdp = ext3_get_group_desc (sb, i, NULL);
 728                 if (!gdp)
 729                         continue;
 730                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 731                 brelse(bitmap_bh);
 732                 bitmap_bh = read_inode_bitmap(sb, i);
 733                 if (!bitmap_bh)
 734                         continue;
 735
 736                 x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
 737                 printk("group %d: stored = %d, counted = %lu\n",
 738                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 739                 bitmap_count += x;
 740         }
 741         brelse(bitmap_bh);
 742         printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 743                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 744         return desc_count;
 745 #else
 746         desc_count = 0;
 747         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 748                 gdp = ext3_get_group_desc (sb, i, NULL);
 749                 if (!gdp)
 750                         continue;
 751                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 752                 cond_resched();
 753         }
 754         return desc_count;
 755 #endif
 756 }
 757
 758 /* Called at mount-time, super-block is locked */
 759 unsigned long ext3_count_dirs (struct super_block * sb)
 760 {
 761         unsigned long count = 0;
 762         int i;
 763
 764         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 765                 struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
 766                 if (!gdp)
 767                         continue;
 768                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 769         }
 770         return count;
 771 }
 772