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         is_directory = S_ISDIR(inode->i_mode);
 123
 124         es = EXT3_SB(sb)->s_es;
 125         if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 126                 ext3_error (sb, "ext3_free_inode",
 127                             "reserved or nonexistent inode %lu", ino);
 128                 goto error_return;
 129         }
 130         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 131         bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 132         bitmap_bh = read_inode_bitmap(sb, block_group);
 133         if (!bitmap_bh)
 134                 goto error_return;
 135
 136         BUFFER_TRACE(bitmap_bh, "get_write_access");
 137         fatal = ext3_journal_get_write_access(handle, bitmap_bh);
 138         if (fatal)
 139                 goto error_return;
 140
 141         /* Ok, now we can actually update the inode bitmaps.. */
 142         if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 143                                         bit, bitmap_bh->b_data))
 144                 ext3_error (sb, "ext3_free_inode",
 145                               "bit already cleared for inode %lu", ino);
 146         else {
 147                 gdp = ext3_get_group_desc (sb, block_group, &bh2);
 148
 149                 BUFFER_TRACE(bh2, "get_write_access");
 150                 fatal = ext3_journal_get_write_access(handle, bh2);
 151                 if (fatal) goto error_return;
 152
 153                 if (gdp) {
 154                         spin_lock(sb_bgl_lock(sbi, block_group));
 155                         le16_add_cpu(&gdp->bg_free_inodes_count, 1);
 156                         if (is_directory)
 157                                 le16_add_cpu(&gdp->bg_used_dirs_count, -1);
 158                         spin_unlock(sb_bgl_lock(sbi, block_group));
 159                         percpu_counter_inc(&sbi->s_freeinodes_counter);
 160                         if (is_directory)
 161                                 percpu_counter_dec(&sbi->s_dirs_counter);
 162
 163                 }
 164                 BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 165                 err = ext3_journal_dirty_metadata(handle, bh2);
 166                 if (!fatal) fatal = err;
 167         }
 168         BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
 169         err = ext3_journal_dirty_metadata(handle, bitmap_bh);
 170         if (!fatal)
 171                 fatal = err;
 172
 173 error_return:
 174         brelse(bitmap_bh);
 175         ext3_std_error(sb, fatal);
 176 }
 177
 178 /*
 179  * There are two policies for allocating an inode.  If the new inode is
 180  * a directory, then a forward search is made for a block group with both
 181  * free space and a low directory-to-inode ratio; if that fails, then of
 182  * the groups with above-average free space, that group with the fewest
 183  * directories already is chosen.
 184  *
 185  * For other inodes, search forward from the parent directory\'s block
 186  * group to find a free inode.
 187  */
 188 static int find_group_dir(struct super_block *sb, struct inode *parent)
 189 {
 190         int ngroups = EXT3_SB(sb)->s_groups_count;
 191         unsigned int freei, avefreei;
 192         struct ext3_group_desc *desc, *best_desc = NULL;
 193         int group, best_group = -1;
 194
 195         freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
 196         avefreei = freei / ngroups;
 197
 198         for (group = 0; group < ngroups; group++) {
 199                 desc = ext3_get_group_desc (sb, group, NULL);
 200                 if (!desc || !desc->bg_free_inodes_count)
 201                         continue;
 202                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 203                         continue;
 204                 if (!best_desc ||
 205                     (le16_to_cpu(desc->bg_free_blocks_count) >
 206                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 207                         best_group = group;
 208                         best_desc = desc;
 209                 }
 210         }
 211         return best_group;
 212 }
 213
 214 /*
 215  * Orlov's allocator for directories.
 216  *
 217  * We always try to spread first-level directories.
 218  *
 219  * If there are blockgroups with both free inodes and free blocks counts
 220  * not worse than average we return one with smallest directory count.
 221  * Otherwise we simply return a random group.
 222  *
 223  * For the rest rules look so:
 224  *
 225  * It's OK to put directory into a group unless
 226  * it has too many directories already (max_dirs) or
 227  * it has too few free inodes left (min_inodes) or
 228  * it has too few free blocks left (min_blocks) or
 229  * it's already running too large debt (max_debt).
 230  * Parent's group is preferred, if it doesn't satisfy these
 231  * conditions we search cyclically through the rest. If none
 232  * of the groups look good we just look for a group with more
 233  * free inodes than average (starting at parent's group).
 234  *
 235  * Debt is incremented each time we allocate a directory and decremented
 236  * when we allocate an inode, within 0--255.
 237  */
 238
 239 #define INODE_COST 64
 240 #define BLOCK_COST 256
 241
 242 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 243 {
 244         int parent_group = EXT3_I(parent)->i_block_group;
 245         struct ext3_sb_info *sbi = EXT3_SB(sb);
 246         struct ext3_super_block *es = sbi->s_es;
 247         int ngroups = sbi->s_groups_count;
 248         int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
 249         unsigned int freei, avefreei;
 250         ext3_fsblk_t freeb, avefreeb;
 251         ext3_fsblk_t blocks_per_dir;
 252         unsigned int ndirs;
 253         int max_debt, max_dirs, min_inodes;
 254         ext3_grpblk_t min_blocks;
 255         int group = -1, i;
 256         struct ext3_group_desc *desc;
 257
 258         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 259         avefreei = freei / ngroups;
 260         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 261         avefreeb = freeb / ngroups;
 262         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 263
 264         if ((parent == sb->s_root->d_inode) ||
 265             (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
 266                 int best_ndir = inodes_per_group;
 267                 int best_group = -1;
 268
 269                 get_random_bytes(&group, sizeof(group));
 270                 parent_group = (unsigned)group % ngroups;
 271                 for (i = 0; i < ngroups; i++) {
 272                         group = (parent_group + i) % ngroups;
 273                         desc = ext3_get_group_desc (sb, group, NULL);
 274                         if (!desc || !desc->bg_free_inodes_count)
 275                                 continue;
 276                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 277                                 continue;
 278                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 279                                 continue;
 280                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 281                                 continue;
 282                         best_group = group;
 283                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 284                 }
 285                 if (best_group >= 0)
 286                         return best_group;
 287                 goto fallback;
 288         }
 289
 290         blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
 291
 292         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 293         min_inodes = avefreei - inodes_per_group / 4;
 294         min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
 295
 296         max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, (ext3_fsblk_t)BLOCK_COST);
 297         if (max_debt * INODE_COST > inodes_per_group)
 298                 max_debt = inodes_per_group / INODE_COST;
 299         if (max_debt > 255)
 300                 max_debt = 255;
 301         if (max_debt == 0)
 302                 max_debt = 1;
 303
 304         for (i = 0; i < ngroups; i++) {
 305                 group = (parent_group + i) % ngroups;
 306                 desc = ext3_get_group_desc (sb, group, NULL);
 307                 if (!desc || !desc->bg_free_inodes_count)
 308                         continue;
 309                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 310                         continue;
 311                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 312                         continue;
 313                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 314                         continue;
 315                 return group;
 316         }
 317
 318 fallback:
 319         for (i = 0; i < ngroups; i++) {
 320                 group = (parent_group + i) % ngroups;
 321                 desc = ext3_get_group_desc (sb, group, NULL);
 322                 if (!desc || !desc->bg_free_inodes_count)
 323                         continue;
 324                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 325                         return group;
 326         }
 327
 328         if (avefreei) {
 329                 /*
 330                  * The free-inodes counter is approximate, and for really small
 331                  * filesystems the above test can fail to find any blockgroups
 332                  */
 333                 avefreei = 0;
 334                 goto fallback;
 335         }
 336
 337         return -1;
 338 }
 339
 340 static int find_group_other(struct super_block *sb, struct inode *parent)
 341 {
 342         int parent_group = EXT3_I(parent)->i_block_group;
 343         int ngroups = EXT3_SB(sb)->s_groups_count;
 344         struct ext3_group_desc *desc;
 345         int group, i;
 346
 347         /*
 348          * Try to place the inode in its parent directory
 349          */
 350         group = parent_group;
 351         desc = ext3_get_group_desc (sb, group, NULL);
 352         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 353                         le16_to_cpu(desc->bg_free_blocks_count))
 354                 return group;
 355
 356         /*
 357          * We're going to place this inode in a different blockgroup from its
 358          * parent.  We want to cause files in a common directory to all land in
 359          * the same blockgroup.  But we want files which are in a different
 360          * directory which shares a blockgroup with our parent to land in a
 361          * different blockgroup.
 362          *
 363          * So add our directory's i_ino into the starting point for the hash.
 364          */
 365         group = (group + parent->i_ino) % ngroups;
 366
 367         /*
 368          * Use a quadratic hash to find a group with a free inode and some free
 369          * blocks.
 370          */
 371         for (i = 1; i < ngroups; i <<= 1) {
 372                 group += i;
 373                 if (group >= ngroups)
 374                         group -= ngroups;
 375                 desc = ext3_get_group_desc (sb, group, NULL);
 376                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 377                                 le16_to_cpu(desc->bg_free_blocks_count))
 378                         return group;
 379         }
 380
 381         /*
 382          * That failed: try linear search for a free inode, even if that group
 383          * has no free blocks.
 384          */
 385         group = parent_group;
 386         for (i = 0; i < ngroups; i++) {
 387                 if (++group >= ngroups)
 388                         group = 0;
 389                 desc = ext3_get_group_desc (sb, group, NULL);
 390                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 391                         return group;
 392         }
 393
 394         return -1;
 395 }
 396
 397 /*
 398  * There are two policies for allocating an inode.  If the new inode is
 399  * a directory, then a forward search is made for a block group with both
 400  * free space and a low directory-to-inode ratio; if that fails, then of
 401  * the groups with above-average free space, that group with the fewest
 402  * directories already is chosen.
 403  *
 404  * For other inodes, search forward from the parent directory's block
 405  * group to find a free inode.
 406  */
 407 struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
 408 {
 409         struct super_block *sb;
 410         struct buffer_head *bitmap_bh = NULL;
 411         struct buffer_head *bh2;
 412         int group;
 413         unsigned long ino = 0;
 414         struct inode * inode;
 415         struct ext3_group_desc * gdp = NULL;
 416         struct ext3_super_block * es;
 417         struct ext3_inode_info *ei;
 418         struct ext3_sb_info *sbi;
 419         int err = 0;
 420         struct inode *ret;
 421         int i;
 422
 423         /* Cannot create files in a deleted directory */
 424         if (!dir || !dir->i_nlink)
 425                 return ERR_PTR(-EPERM);
 426
 427         sb = dir->i_sb;
 428         inode = new_inode(sb);
 429         if (!inode)
 430                 return ERR_PTR(-ENOMEM);
 431         ei = EXT3_I(inode);
 432
 433         sbi = EXT3_SB(sb);
 434         es = sbi->s_es;
 435         if (S_ISDIR(mode)) {
 436                 if (test_opt (sb, OLDALLOC))
 437                         group = find_group_dir(sb, dir);
 438                 else
 439                         group = find_group_orlov(sb, dir);
 440         } else
 441                 group = find_group_other(sb, dir);
 442
 443         err = -ENOSPC;
 444         if (group == -1)
 445                 goto out;
 446
 447         for (i = 0; i < sbi->s_groups_count; i++) {
 448                 err = -EIO;
 449
 450                 gdp = ext3_get_group_desc(sb, group, &bh2);
 451                 if (!gdp)
 452                         goto fail;
 453
 454                 brelse(bitmap_bh);
 455                 bitmap_bh = read_inode_bitmap(sb, group);
 456                 if (!bitmap_bh)
 457                         goto fail;
 458
 459                 ino = 0;
 460
 461 repeat_in_this_group:
 462                 ino = ext3_find_next_zero_bit((unsigned long *)
 463                                 bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
 464                 if (ino < EXT3_INODES_PER_GROUP(sb)) {
 465
 466                         BUFFER_TRACE(bitmap_bh, "get_write_access");
 467                         err = ext3_journal_get_write_access(handle, bitmap_bh);
 468                         if (err)
 469                                 goto fail;
 470
 471                         if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
 472                                                 ino, bitmap_bh->b_data)) {
 473                                 /* we won it */
 474                                 BUFFER_TRACE(bitmap_bh,
 475                                         "call ext3_journal_dirty_metadata");
 476                                 err = ext3_journal_dirty_metadata(handle,
 477                                                                 bitmap_bh);
 478                                 if (err)
 479                                         goto fail;
 480                                 goto got;
 481                         }
 482                         /* we lost it */
 483                         journal_release_buffer(handle, bitmap_bh);
 484
 485                         if (++ino < EXT3_INODES_PER_GROUP(sb))
 486                                 goto repeat_in_this_group;
 487                 }
 488
 489                 /*
 490                  * This case is possible in concurrent environment.  It is very
 491                  * rare.  We cannot repeat the find_group_xxx() call because
 492                  * that will simply return the same blockgroup, because the
 493                  * group descriptor metadata has not yet been updated.
 494                  * So we just go onto the next blockgroup.
 495                  */
 496                 if (++group == sbi->s_groups_count)
 497                         group = 0;
 498         }
 499         err = -ENOSPC;
 500         goto out;
 501
 502 got:
 503         ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
 504         if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 505                 ext3_error (sb, "ext3_new_inode",
 506                             "reserved inode or inode > inodes count - "
 507                             "block_group = %d, inode=%lu", group, ino);
 508                 err = -EIO;
 509                 goto fail;
 510         }
 511
 512         BUFFER_TRACE(bh2, "get_write_access");
 513         err = ext3_journal_get_write_access(handle, bh2);
 514         if (err) goto fail;
 515         spin_lock(sb_bgl_lock(sbi, group));
 516         le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 517         if (S_ISDIR(mode)) {
 518                 le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 519         }
 520         spin_unlock(sb_bgl_lock(sbi, group));
 521         BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
 522         err = ext3_journal_dirty_metadata(handle, bh2);
 523         if (err) goto fail;
 524
 525         percpu_counter_dec(&sbi->s_freeinodes_counter);
 526         if (S_ISDIR(mode))
 527                 percpu_counter_inc(&sbi->s_dirs_counter);
 528
 529
 530         if (test_opt(sb, GRPID)) {
 531                 inode->i_mode = mode;
 532                 inode->i_uid = current_fsuid();
 533                 inode->i_gid = dir->i_gid;
 534         } else
 535                 inode_init_owner(inode, dir, mode);
 536
 537         inode->i_ino = ino;
 538         /* This is the optimal IO size (for stat), not the fs block size */
 539         inode->i_blocks = 0;
 540         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 541
 542         memset(ei->i_data, 0, sizeof(ei->i_data));
 543         ei->i_dir_start_lookup = 0;
 544         ei->i_disksize = 0;
 545
 546         ei->i_flags =
 547                 ext3_mask_flags(mode, EXT3_I(dir)->i_flags & EXT3_FL_INHERITED);
 548 #ifdef EXT3_FRAGMENTS
 549         ei->i_faddr = 0;
 550         ei->i_frag_no = 0;
 551         ei->i_frag_size = 0;
 552 #endif
 553         ei->i_file_acl = 0;
 554         ei->i_dir_acl = 0;
 555         ei->i_dtime = 0;
 556         ei->i_block_alloc_info = NULL;
 557         ei->i_block_group = group;
 558
 559         ext3_set_inode_flags(inode);
 560         if (IS_DIRSYNC(inode))
 561                 handle->h_sync = 1;
 562         if (insert_inode_locked(inode) < 0) {
 563                 err = -EINVAL;
 564                 goto fail_drop;
 565         }
 566         spin_lock(&sbi->s_next_gen_lock);
 567         inode->i_generation = sbi->s_next_generation++;
 568         spin_unlock(&sbi->s_next_gen_lock);
 569
 570         ei->i_state_flags = 0;
 571         ext3_set_inode_state(inode, EXT3_STATE_NEW);
 572
 573         ei->i_extra_isize =
 574                 (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) ?
 575                 sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE : 0;
 576
 577         ret = inode;
 578         dquot_initialize(inode);
 579         err = dquot_alloc_inode(inode);
 580         if (err)
 581                 goto fail_drop;
 582
 583         err = ext3_init_acl(handle, inode, dir);
 584         if (err)
 585                 goto fail_free_drop;
 586
 587         err = ext3_init_security(handle,inode, dir);
 588         if (err)
 589                 goto fail_free_drop;
 590
 591         err = ext3_mark_inode_dirty(handle, inode);
 592         if (err) {
 593                 ext3_std_error(sb, err);
 594                 goto fail_free_drop;
 595         }
 596
 597         ext3_debug("allocating inode %lu\n", inode->i_ino);
 598         goto really_out;
 599 fail:
 600         ext3_std_error(sb, err);
 601 out:
 602         iput(inode);
 603         ret = ERR_PTR(err);
 604 really_out:
 605         brelse(bitmap_bh);
 606         return ret;
 607
 608 fail_free_drop:
 609         dquot_free_inode(inode);
 610
 611 fail_drop:
 612         dquot_drop(inode);
 613         inode->i_flags |= S_NOQUOTA;
 614         inode->i_nlink = 0;
 615         unlock_new_inode(inode);
 616         iput(inode);
 617         brelse(bitmap_bh);
 618         return ERR_PTR(err);
 619 }
 620
 621 /* Verify that we are loading a valid orphan from disk */
 622 struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
 623 {
 624         unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
 625         unsigned long block_group;
 626         int bit;
 627         struct buffer_head *bitmap_bh;
 628         struct inode *inode = NULL;
 629         long err = -EIO;
 630
 631         /* Error cases - e2fsck has already cleaned up for us */
 632         if (ino > max_ino) {
 633                 ext3_warning(sb, __func__,
 634                              "bad orphan ino %lu!  e2fsck was run?", ino);
 635                 goto error;
 636         }
 637
 638         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
 639         bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
 640         bitmap_bh = read_inode_bitmap(sb, block_group);
 641         if (!bitmap_bh) {
 642                 ext3_warning(sb, __func__,
 643                              "inode bitmap error for orphan %lu", ino);
 644                 goto error;
 645         }
 646
 647         /* Having the inode bit set should be a 100% indicator that this
 648          * is a valid orphan (no e2fsck run on fs).  Orphans also include
 649          * inodes that were being truncated, so we can't check i_nlink==0.
 650          */
 651         if (!ext3_test_bit(bit, bitmap_bh->b_data))
 652                 goto bad_orphan;
 653
 654         inode = ext3_iget(sb, ino);
 655         if (IS_ERR(inode))
 656                 goto iget_failed;
 657
 658         /*
 659          * If the orphans has i_nlinks > 0 then it should be able to be
 660          * truncated, otherwise it won't be removed from the orphan list
 661          * during processing and an infinite loop will result.
 662          */
 663         if (inode->i_nlink && !ext3_can_truncate(inode))
 664                 goto bad_orphan;
 665
 666         if (NEXT_ORPHAN(inode) > max_ino)
 667                 goto bad_orphan;
 668         brelse(bitmap_bh);
 669         return inode;
 670
 671 iget_failed:
 672         err = PTR_ERR(inode);
 673         inode = NULL;
 674 bad_orphan:
 675         ext3_warning(sb, __func__,
 676                      "bad orphan inode %lu!  e2fsck was run?", ino);
 677         printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
 678                bit, (unsigned long long)bitmap_bh->b_blocknr,
 679                ext3_test_bit(bit, bitmap_bh->b_data));
 680         printk(KERN_NOTICE "inode=%p\n", inode);
 681         if (inode) {
 682                 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 683                        is_bad_inode(inode));
 684                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 685                        NEXT_ORPHAN(inode));
 686                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 687                 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
 688                 /* Avoid freeing blocks if we got a bad deleted inode */
 689                 if (inode->i_nlink == 0)
 690                         inode->i_blocks = 0;
 691                 iput(inode);
 692         }
 693         brelse(bitmap_bh);
 694 error:
 695         return ERR_PTR(err);
 696 }
 697
 698 unsigned long ext3_count_free_inodes (struct super_block * sb)
 699 {
 700         unsigned long desc_count;
 701         struct ext3_group_desc *gdp;
 702         int i;
 703 #ifdef EXT3FS_DEBUG
 704         struct ext3_super_block *es;
 705         unsigned long bitmap_count, x;
 706         struct buffer_head *bitmap_bh = NULL;
 707
 708         es = EXT3_SB(sb)->s_es;
 709         desc_count = 0;
 710         bitmap_count = 0;
 711         gdp = NULL;
 712         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 713                 gdp = ext3_get_group_desc (sb, i, NULL);
 714                 if (!gdp)
 715                         continue;
 716                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 717                 brelse(bitmap_bh);
 718                 bitmap_bh = read_inode_bitmap(sb, i);
 719                 if (!bitmap_bh)
 720                         continue;
 721
 722                 x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
 723                 printk("group %d: stored = %d, counted = %lu\n",
 724                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 725                 bitmap_count += x;
 726         }
 727         brelse(bitmap_bh);
 728         printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 729                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 730         return desc_count;
 731 #else
 732         desc_count = 0;
 733         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 734                 gdp = ext3_get_group_desc (sb, i, NULL);
 735                 if (!gdp)
 736                         continue;
 737                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 738                 cond_resched();
 739         }
 740         return desc_count;
 741 #endif
 742 }
 743
 744 /* Called at mount-time, super-block is locked */
 745 unsigned long ext3_count_dirs (struct super_block * sb)
 746 {
 747         unsigned long count = 0;
 748         int i;
 749
 750         for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
 751                 struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
 752                 if (!gdp)
 753                         continue;
 754                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 755         }
 756         return count;
 757 }
 758