git.oblomov.eu Git - linux-2.6/blob - fs/ext4/ialloc.c

   1 /*
   2  *  linux/fs/ext4/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/jbd2.h>
  18 #include <linux/ext4_fs.h>
  19 #include <linux/ext4_jbd2.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 #include <linux/blkdev.h>
  27 #include <asm/byteorder.h>
  28
  29 #include "xattr.h"
  30 #include "acl.h"
  31 #include "group.h"
  32
  33 /*
  34  * ialloc.c contains the inodes allocation and deallocation routines
  35  */
  36
  37 /*
  38  * The free inodes are managed by bitmaps.  A file system contains several
  39  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  40  * block for inodes, N blocks for the inode table and data blocks.
  41  *
  42  * The file system contains group descriptors which are located after the
  43  * super block.  Each descriptor contains the number of the bitmap block and
  44  * the free blocks count in the block.
  45  */
  46
  47 /*
  48  * To avoid calling the atomic setbit hundreds or thousands of times, we only
  49  * need to use it within a single byte (to ensure we get endianness right).
  50  * We can use memset for the rest of the bitmap as there are no other users.
  51  */
  52 void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
  53 {
  54         int i;
  55
  56         if (start_bit >= end_bit)
  57                 return;
  58
  59         ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
  60         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
  61                 ext4_set_bit(i, bitmap);
  62         if (i < end_bit)
  63                 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
  64 }
  65
  66 /* Initializes an uninitialized inode bitmap */
  67 unsigned ext4_init_inode_bitmap(struct super_block *sb,
  68                                 struct buffer_head *bh, int block_group,
  69                                 struct ext4_group_desc *gdp)
  70 {
  71         struct ext4_sb_info *sbi = EXT4_SB(sb);
  72
  73         J_ASSERT_BH(bh, buffer_locked(bh));
  74
  75         /* If checksum is bad mark all blocks and inodes use to prevent
  76          * allocation, essentially implementing a per-group read-only flag. */
  77         if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
  78                 ext4_error(sb, __FUNCTION__, "Checksum bad for group %u\n",
  79                            block_group);
  80                 gdp->bg_free_blocks_count = 0;
  81                 gdp->bg_free_inodes_count = 0;
  82                 gdp->bg_itable_unused = 0;
  83                 memset(bh->b_data, 0xff, sb->s_blocksize);
  84                 return 0;
  85         }
  86
  87         memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
  88         mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb),
  89                         bh->b_data);
  90
  91         return EXT4_INODES_PER_GROUP(sb);
  92 }
  93
  94 /*
  95  * Read the inode allocation bitmap for a given block_group, reading
  96  * into the specified slot in the superblock's bitmap cache.
  97  *
  98  * Return buffer_head of bitmap on success or NULL.
  99  */
 100 static struct buffer_head *
 101 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
 102 {
 103         struct ext4_group_desc *desc;
 104         struct buffer_head *bh = NULL;
 105
 106         desc = ext4_get_group_desc(sb, block_group, NULL);
 107         if (!desc)
 108                 goto error_out;
 109         if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 110                 bh = sb_getblk(sb, ext4_inode_bitmap(sb, desc));
 111                 if (!buffer_uptodate(bh)) {
 112                         lock_buffer(bh);
 113                         if (!buffer_uptodate(bh)) {
 114                                 ext4_init_inode_bitmap(sb, bh, block_group,
 115                                                        desc);
 116                                 set_buffer_uptodate(bh);
 117                         }
 118                         unlock_buffer(bh);
 119                 }
 120         } else {
 121                 bh = sb_bread(sb, ext4_inode_bitmap(sb, desc));
 122         }
 123         if (!bh)
 124                 ext4_error(sb, "read_inode_bitmap",
 125                             "Cannot read inode bitmap - "
 126                             "block_group = %lu, inode_bitmap = %llu",
 127                             block_group, ext4_inode_bitmap(sb, desc));
 128 error_out:
 129         return bh;
 130 }
 131
 132 /*
 133  * NOTE! When we get the inode, we're the only people
 134  * that have access to it, and as such there are no
 135  * race conditions we have to worry about. The inode
 136  * is not on the hash-lists, and it cannot be reached
 137  * through the filesystem because the directory entry
 138  * has been deleted earlier.
 139  *
 140  * HOWEVER: we must make sure that we get no aliases,
 141  * which means that we have to call "clear_inode()"
 142  * _before_ we mark the inode not in use in the inode
 143  * bitmaps. Otherwise a newly created file might use
 144  * the same inode number (not actually the same pointer
 145  * though), and then we'd have two inodes sharing the
 146  * same inode number and space on the harddisk.
 147  */
 148 void ext4_free_inode (handle_t *handle, struct inode * inode)
 149 {
 150         struct super_block * sb = inode->i_sb;
 151         int is_directory;
 152         unsigned long ino;
 153         struct buffer_head *bitmap_bh = NULL;
 154         struct buffer_head *bh2;
 155         unsigned long block_group;
 156         unsigned long bit;
 157         struct ext4_group_desc * gdp;
 158         struct ext4_super_block * es;
 159         struct ext4_sb_info *sbi;
 160         int fatal = 0, err;
 161
 162         if (atomic_read(&inode->i_count) > 1) {
 163                 printk ("ext4_free_inode: inode has count=%d\n",
 164                                         atomic_read(&inode->i_count));
 165                 return;
 166         }
 167         if (inode->i_nlink) {
 168                 printk ("ext4_free_inode: inode has nlink=%d\n",
 169                         inode->i_nlink);
 170                 return;
 171         }
 172         if (!sb) {
 173                 printk("ext4_free_inode: inode on nonexistent device\n");
 174                 return;
 175         }
 176         sbi = EXT4_SB(sb);
 177
 178         ino = inode->i_ino;
 179         ext4_debug ("freeing inode %lu\n", ino);
 180
 181         /*
 182          * Note: we must free any quota before locking the superblock,
 183          * as writing the quota to disk may need the lock as well.
 184          */
 185         DQUOT_INIT(inode);
 186         ext4_xattr_delete_inode(handle, inode);
 187         DQUOT_FREE_INODE(inode);
 188         DQUOT_DROP(inode);
 189
 190         is_directory = S_ISDIR(inode->i_mode);
 191
 192         /* Do this BEFORE marking the inode not in use or returning an error */
 193         clear_inode (inode);
 194
 195         es = EXT4_SB(sb)->s_es;
 196         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 197                 ext4_error (sb, "ext4_free_inode",
 198                             "reserved or nonexistent inode %lu", ino);
 199                 goto error_return;
 200         }
 201         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 202         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 203         bitmap_bh = read_inode_bitmap(sb, block_group);
 204         if (!bitmap_bh)
 205                 goto error_return;
 206
 207         BUFFER_TRACE(bitmap_bh, "get_write_access");
 208         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 209         if (fatal)
 210                 goto error_return;
 211
 212         /* Ok, now we can actually update the inode bitmaps.. */
 213         if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 214                                         bit, bitmap_bh->b_data))
 215                 ext4_error (sb, "ext4_free_inode",
 216                               "bit already cleared for inode %lu", ino);
 217         else {
 218                 gdp = ext4_get_group_desc (sb, block_group, &bh2);
 219
 220                 BUFFER_TRACE(bh2, "get_write_access");
 221                 fatal = ext4_journal_get_write_access(handle, bh2);
 222                 if (fatal) goto error_return;
 223
 224                 if (gdp) {
 225                         spin_lock(sb_bgl_lock(sbi, block_group));
 226                         gdp->bg_free_inodes_count = cpu_to_le16(
 227                                 le16_to_cpu(gdp->bg_free_inodes_count) + 1);
 228                         if (is_directory)
 229                                 gdp->bg_used_dirs_count = cpu_to_le16(
 230                                   le16_to_cpu(gdp->bg_used_dirs_count) - 1);
 231                         gdp->bg_checksum = ext4_group_desc_csum(sbi,
 232                                                         block_group, gdp);
 233                         spin_unlock(sb_bgl_lock(sbi, block_group));
 234                         percpu_counter_inc(&sbi->s_freeinodes_counter);
 235                         if (is_directory)
 236                                 percpu_counter_dec(&sbi->s_dirs_counter);
 237
 238                 }
 239                 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
 240                 err = ext4_journal_dirty_metadata(handle, bh2);
 241                 if (!fatal) fatal = err;
 242         }
 243         BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
 244         err = ext4_journal_dirty_metadata(handle, bitmap_bh);
 245         if (!fatal)
 246                 fatal = err;
 247         sb->s_dirt = 1;
 248 error_return:
 249         brelse(bitmap_bh);
 250         ext4_std_error(sb, fatal);
 251 }
 252
 253 /*
 254  * There are two policies for allocating an inode.  If the new inode is
 255  * a directory, then a forward search is made for a block group with both
 256  * free space and a low directory-to-inode ratio; if that fails, then of
 257  * the groups with above-average free space, that group with the fewest
 258  * directories already is chosen.
 259  *
 260  * For other inodes, search forward from the parent directory\'s block
 261  * group to find a free inode.
 262  */
 263 static int find_group_dir(struct super_block *sb, struct inode *parent)
 264 {
 265         int ngroups = EXT4_SB(sb)->s_groups_count;
 266         unsigned int freei, avefreei;
 267         struct ext4_group_desc *desc, *best_desc = NULL;
 268         int group, best_group = -1;
 269
 270         freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
 271         avefreei = freei / ngroups;
 272
 273         for (group = 0; group < ngroups; group++) {
 274                 desc = ext4_get_group_desc (sb, group, NULL);
 275                 if (!desc || !desc->bg_free_inodes_count)
 276                         continue;
 277                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 278                         continue;
 279                 if (!best_desc ||
 280                     (le16_to_cpu(desc->bg_free_blocks_count) >
 281                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 282                         best_group = group;
 283                         best_desc = desc;
 284                 }
 285         }
 286         return best_group;
 287 }
 288
 289 /*
 290  * Orlov's allocator for directories.
 291  *
 292  * We always try to spread first-level directories.
 293  *
 294  * If there are blockgroups with both free inodes and free blocks counts
 295  * not worse than average we return one with smallest directory count.
 296  * Otherwise we simply return a random group.
 297  *
 298  * For the rest rules look so:
 299  *
 300  * It's OK to put directory into a group unless
 301  * it has too many directories already (max_dirs) or
 302  * it has too few free inodes left (min_inodes) or
 303  * it has too few free blocks left (min_blocks) or
 304  * it's already running too large debt (max_debt).
 305  * Parent's group is prefered, if it doesn't satisfy these
 306  * conditions we search cyclically through the rest. If none
 307  * of the groups look good we just look for a group with more
 308  * free inodes than average (starting at parent's group).
 309  *
 310  * Debt is incremented each time we allocate a directory and decremented
 311  * when we allocate an inode, within 0--255.
 312  */
 313
 314 #define INODE_COST 64
 315 #define BLOCK_COST 256
 316
 317 static int find_group_orlov(struct super_block *sb, struct inode *parent)
 318 {
 319         int parent_group = EXT4_I(parent)->i_block_group;
 320         struct ext4_sb_info *sbi = EXT4_SB(sb);
 321         struct ext4_super_block *es = sbi->s_es;
 322         int ngroups = sbi->s_groups_count;
 323         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 324         unsigned int freei, avefreei;
 325         ext4_fsblk_t freeb, avefreeb;
 326         ext4_fsblk_t blocks_per_dir;
 327         unsigned int ndirs;
 328         int max_debt, max_dirs, min_inodes;
 329         ext4_grpblk_t min_blocks;
 330         int group = -1, i;
 331         struct ext4_group_desc *desc;
 332
 333         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 334         avefreei = freei / ngroups;
 335         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 336         avefreeb = freeb;
 337         do_div(avefreeb, ngroups);
 338         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 339
 340         if ((parent == sb->s_root->d_inode) ||
 341             (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
 342                 int best_ndir = inodes_per_group;
 343                 int best_group = -1;
 344
 345                 get_random_bytes(&group, sizeof(group));
 346                 parent_group = (unsigned)group % ngroups;
 347                 for (i = 0; i < ngroups; i++) {
 348                         group = (parent_group + i) % ngroups;
 349                         desc = ext4_get_group_desc (sb, group, NULL);
 350                         if (!desc || !desc->bg_free_inodes_count)
 351                                 continue;
 352                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 353                                 continue;
 354                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 355                                 continue;
 356                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 357                                 continue;
 358                         best_group = group;
 359                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 360                 }
 361                 if (best_group >= 0)
 362                         return best_group;
 363                 goto fallback;
 364         }
 365
 366         blocks_per_dir = ext4_blocks_count(es) - freeb;
 367         do_div(blocks_per_dir, ndirs);
 368
 369         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 370         min_inodes = avefreei - inodes_per_group / 4;
 371         min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
 372
 373         max_debt = EXT4_BLOCKS_PER_GROUP(sb);
 374         max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
 375         if (max_debt * INODE_COST > inodes_per_group)
 376                 max_debt = inodes_per_group / INODE_COST;
 377         if (max_debt > 255)
 378                 max_debt = 255;
 379         if (max_debt == 0)
 380                 max_debt = 1;
 381
 382         for (i = 0; i < ngroups; i++) {
 383                 group = (parent_group + i) % ngroups;
 384                 desc = ext4_get_group_desc (sb, group, NULL);
 385                 if (!desc || !desc->bg_free_inodes_count)
 386                         continue;
 387                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 388                         continue;
 389                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 390                         continue;
 391                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 392                         continue;
 393                 return group;
 394         }
 395
 396 fallback:
 397         for (i = 0; i < ngroups; i++) {
 398                 group = (parent_group + i) % ngroups;
 399                 desc = ext4_get_group_desc (sb, group, NULL);
 400                 if (!desc || !desc->bg_free_inodes_count)
 401                         continue;
 402                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 403                         return group;
 404         }
 405
 406         if (avefreei) {
 407                 /*
 408                  * The free-inodes counter is approximate, and for really small
 409                  * filesystems the above test can fail to find any blockgroups
 410                  */
 411                 avefreei = 0;
 412                 goto fallback;
 413         }
 414
 415         return -1;
 416 }
 417
 418 static int find_group_other(struct super_block *sb, struct inode *parent)
 419 {
 420         int parent_group = EXT4_I(parent)->i_block_group;
 421         int ngroups = EXT4_SB(sb)->s_groups_count;
 422         struct ext4_group_desc *desc;
 423         int group, i;
 424
 425         /*
 426          * Try to place the inode in its parent directory
 427          */
 428         group = parent_group;
 429         desc = ext4_get_group_desc (sb, group, NULL);
 430         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 431                         le16_to_cpu(desc->bg_free_blocks_count))
 432                 return group;
 433
 434         /*
 435          * We're going to place this inode in a different blockgroup from its
 436          * parent.  We want to cause files in a common directory to all land in
 437          * the same blockgroup.  But we want files which are in a different
 438          * directory which shares a blockgroup with our parent to land in a
 439          * different blockgroup.
 440          *
 441          * So add our directory's i_ino into the starting point for the hash.
 442          */
 443         group = (group + parent->i_ino) % ngroups;
 444
 445         /*
 446          * Use a quadratic hash to find a group with a free inode and some free
 447          * blocks.
 448          */
 449         for (i = 1; i < ngroups; i <<= 1) {
 450                 group += i;
 451                 if (group >= ngroups)
 452                         group -= ngroups;
 453                 desc = ext4_get_group_desc (sb, group, NULL);
 454                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 455                                 le16_to_cpu(desc->bg_free_blocks_count))
 456                         return group;
 457         }
 458
 459         /*
 460          * That failed: try linear search for a free inode, even if that group
 461          * has no free blocks.
 462          */
 463         group = parent_group;
 464         for (i = 0; i < ngroups; i++) {
 465                 if (++group >= ngroups)
 466                         group = 0;
 467                 desc = ext4_get_group_desc (sb, group, NULL);
 468                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 469                         return group;
 470         }
 471
 472         return -1;
 473 }
 474
 475 /*
 476  * There are two policies for allocating an inode.  If the new inode is
 477  * a directory, then a forward search is made for a block group with both
 478  * free space and a low directory-to-inode ratio; if that fails, then of
 479  * the groups with above-average free space, that group with the fewest
 480  * directories already is chosen.
 481  *
 482  * For other inodes, search forward from the parent directory's block
 483  * group to find a free inode.
 484  */
 485 struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 486 {
 487         struct super_block *sb;
 488         struct buffer_head *bitmap_bh = NULL;
 489         struct buffer_head *bh2;
 490         int group;
 491         unsigned long ino = 0;
 492         struct inode * inode;
 493         struct ext4_group_desc * gdp = NULL;
 494         struct ext4_super_block * es;
 495         struct ext4_inode_info *ei;
 496         struct ext4_sb_info *sbi;
 497         int err = 0;
 498         struct inode *ret;
 499         int i, free = 0;
 500
 501         /* Cannot create files in a deleted directory */
 502         if (!dir || !dir->i_nlink)
 503                 return ERR_PTR(-EPERM);
 504
 505         sb = dir->i_sb;
 506         inode = new_inode(sb);
 507         if (!inode)
 508                 return ERR_PTR(-ENOMEM);
 509         ei = EXT4_I(inode);
 510
 511         sbi = EXT4_SB(sb);
 512         es = sbi->s_es;
 513         if (S_ISDIR(mode)) {
 514                 if (test_opt (sb, OLDALLOC))
 515                         group = find_group_dir(sb, dir);
 516                 else
 517                         group = find_group_orlov(sb, dir);
 518         } else
 519                 group = find_group_other(sb, dir);
 520
 521         err = -ENOSPC;
 522         if (group == -1)
 523                 goto out;
 524
 525         for (i = 0; i < sbi->s_groups_count; i++) {
 526                 err = -EIO;
 527
 528                 gdp = ext4_get_group_desc(sb, group, &bh2);
 529                 if (!gdp)
 530                         goto fail;
 531
 532                 brelse(bitmap_bh);
 533                 bitmap_bh = read_inode_bitmap(sb, group);
 534                 if (!bitmap_bh)
 535                         goto fail;
 536
 537                 ino = 0;
 538
 539 repeat_in_this_group:
 540                 ino = ext4_find_next_zero_bit((unsigned long *)
 541                                 bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
 542                 if (ino < EXT4_INODES_PER_GROUP(sb)) {
 543
 544                         BUFFER_TRACE(bitmap_bh, "get_write_access");
 545                         err = ext4_journal_get_write_access(handle, bitmap_bh);
 546                         if (err)
 547                                 goto fail;
 548
 549                         if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
 550                                                 ino, bitmap_bh->b_data)) {
 551                                 /* we won it */
 552                                 BUFFER_TRACE(bitmap_bh,
 553                                         "call ext4_journal_dirty_metadata");
 554                                 err = ext4_journal_dirty_metadata(handle,
 555                                                                 bitmap_bh);
 556                                 if (err)
 557                                         goto fail;
 558                                 goto got;
 559                         }
 560                         /* we lost it */
 561                         jbd2_journal_release_buffer(handle, bitmap_bh);
 562
 563                         if (++ino < EXT4_INODES_PER_GROUP(sb))
 564                                 goto repeat_in_this_group;
 565                 }
 566
 567                 /*
 568                  * This case is possible in concurrent environment.  It is very
 569                  * rare.  We cannot repeat the find_group_xxx() call because
 570                  * that will simply return the same blockgroup, because the
 571                  * group descriptor metadata has not yet been updated.
 572                  * So we just go onto the next blockgroup.
 573                  */
 574                 if (++group == sbi->s_groups_count)
 575                         group = 0;
 576         }
 577         err = -ENOSPC;
 578         goto out;
 579
 580 got:
 581         ino++;
 582         if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
 583             ino > EXT4_INODES_PER_GROUP(sb)) {
 584                 ext4_error(sb, __FUNCTION__,
 585                            "reserved inode or inode > inodes count - "
 586                            "block_group = %d, inode=%lu", group,
 587                            ino + group * EXT4_INODES_PER_GROUP(sb));
 588                 err = -EIO;
 589                 goto fail;
 590         }
 591
 592         BUFFER_TRACE(bh2, "get_write_access");
 593         err = ext4_journal_get_write_access(handle, bh2);
 594         if (err) goto fail;
 595
 596         /* We may have to initialize the block bitmap if it isn't already */
 597         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 598             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 599                 struct buffer_head *block_bh = read_block_bitmap(sb, group);
 600
 601                 BUFFER_TRACE(block_bh, "get block bitmap access");
 602                 err = ext4_journal_get_write_access(handle, block_bh);
 603                 if (err) {
 604                         brelse(block_bh);
 605                         goto fail;
 606                 }
 607
 608                 free = 0;
 609                 spin_lock(sb_bgl_lock(sbi, group));
 610                 /* recheck and clear flag under lock if we still need to */
 611                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 612                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 613                         free = ext4_free_blocks_after_init(sb, group, gdp);
 614                         gdp->bg_free_blocks_count = cpu_to_le16(free);
 615                 }
 616                 spin_unlock(sb_bgl_lock(sbi, group));
 617
 618                 /* Don't need to dirty bitmap block if we didn't change it */
 619                 if (free) {
 620                         BUFFER_TRACE(block_bh, "dirty block bitmap");
 621                         err = ext4_journal_dirty_metadata(handle, block_bh);
 622                 }
 623
 624                 brelse(block_bh);
 625                 if (err)
 626                         goto fail;
 627         }
 628
 629         spin_lock(sb_bgl_lock(sbi, group));
 630         /* If we didn't allocate from within the initialized part of the inode
 631          * table then we need to initialize up to this inode. */
 632         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 633                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 634                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
 635
 636                         /* When marking the block group with
 637                          * ~EXT4_BG_INODE_UNINIT we don't want to depend
 638                          * on the value of bg_itable_unsed even though
 639                          * mke2fs could have initialized the same for us.
 640                          * Instead we calculated the value below
 641                          */
 642
 643                         free = 0;
 644                 } else {
 645                         free = EXT4_INODES_PER_GROUP(sb) -
 646                                 le16_to_cpu(gdp->bg_itable_unused);
 647                 }
 648
 649                 /*
 650                  * Check the relative inode number against the last used
 651                  * relative inode number in this group. if it is greater
 652                  * we need to  update the bg_itable_unused count
 653                  *
 654                  */
 655                 if (ino > free)
 656                         gdp->bg_itable_unused =
 657                                 cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
 658         }
 659
 660         gdp->bg_free_inodes_count =
 661                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
 662         if (S_ISDIR(mode)) {
 663                 gdp->bg_used_dirs_count =
 664                         cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
 665         }
 666         gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
 667         spin_unlock(sb_bgl_lock(sbi, group));
 668         BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
 669         err = ext4_journal_dirty_metadata(handle, bh2);
 670         if (err) goto fail;
 671
 672         percpu_counter_dec(&sbi->s_freeinodes_counter);
 673         if (S_ISDIR(mode))
 674                 percpu_counter_inc(&sbi->s_dirs_counter);
 675         sb->s_dirt = 1;
 676
 677         inode->i_uid = current->fsuid;
 678         if (test_opt (sb, GRPID))
 679                 inode->i_gid = dir->i_gid;
 680         else if (dir->i_mode & S_ISGID) {
 681                 inode->i_gid = dir->i_gid;
 682                 if (S_ISDIR(mode))
 683                         mode |= S_ISGID;
 684         } else
 685                 inode->i_gid = current->fsgid;
 686         inode->i_mode = mode;
 687
 688         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
 689         /* This is the optimal IO size (for stat), not the fs block size */
 690         inode->i_blocks = 0;
 691         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
 692                                                        ext4_current_time(inode);
 693
 694         memset(ei->i_data, 0, sizeof(ei->i_data));
 695         ei->i_dir_start_lookup = 0;
 696         ei->i_disksize = 0;
 697
 698         ei->i_flags = EXT4_I(dir)->i_flags & ~EXT4_INDEX_FL;
 699         if (S_ISLNK(mode))
 700                 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
 701         /* dirsync only applies to directories */
 702         if (!S_ISDIR(mode))
 703                 ei->i_flags &= ~EXT4_DIRSYNC_FL;
 704         ei->i_file_acl = 0;
 705         ei->i_dir_acl = 0;
 706         ei->i_dtime = 0;
 707         ei->i_block_alloc_info = NULL;
 708         ei->i_block_group = group;
 709
 710         ext4_set_inode_flags(inode);
 711         if (IS_DIRSYNC(inode))
 712                 handle->h_sync = 1;
 713         insert_inode_hash(inode);
 714         spin_lock(&sbi->s_next_gen_lock);
 715         inode->i_generation = sbi->s_next_generation++;
 716         spin_unlock(&sbi->s_next_gen_lock);
 717
 718         ei->i_state = EXT4_STATE_NEW;
 719
 720         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
 721
 722         ret = inode;
 723         if(DQUOT_ALLOC_INODE(inode)) {
 724                 err = -EDQUOT;
 725                 goto fail_drop;
 726         }
 727
 728         err = ext4_init_acl(handle, inode, dir);
 729         if (err)
 730                 goto fail_free_drop;
 731
 732         err = ext4_init_security(handle,inode, dir);
 733         if (err)
 734                 goto fail_free_drop;
 735
 736         err = ext4_mark_inode_dirty(handle, inode);
 737         if (err) {
 738                 ext4_std_error(sb, err);
 739                 goto fail_free_drop;
 740         }
 741         if (test_opt(sb, EXTENTS)) {
 742                 EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
 743                 ext4_ext_tree_init(handle, inode);
 744                 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 745                         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
 746                         if (err) goto fail;
 747                         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS);
 748                         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "call ext4_journal_dirty_metadata");
 749                         err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
 750                 }
 751         }
 752
 753         ext4_debug("allocating inode %lu\n", inode->i_ino);
 754         goto really_out;
 755 fail:
 756         ext4_std_error(sb, err);
 757 out:
 758         iput(inode);
 759         ret = ERR_PTR(err);
 760 really_out:
 761         brelse(bitmap_bh);
 762         return ret;
 763
 764 fail_free_drop:
 765         DQUOT_FREE_INODE(inode);
 766
 767 fail_drop:
 768         DQUOT_DROP(inode);
 769         inode->i_flags |= S_NOQUOTA;
 770         inode->i_nlink = 0;
 771         iput(inode);
 772         brelse(bitmap_bh);
 773         return ERR_PTR(err);
 774 }
 775
 776 /* Verify that we are loading a valid orphan from disk */
 777 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 778 {
 779         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 780         unsigned long block_group;
 781         int bit;
 782         struct buffer_head *bitmap_bh = NULL;
 783         struct inode *inode = NULL;
 784
 785         /* Error cases - e2fsck has already cleaned up for us */
 786         if (ino > max_ino) {
 787                 ext4_warning(sb, __FUNCTION__,
 788                              "bad orphan ino %lu!  e2fsck was run?", ino);
 789                 goto out;
 790         }
 791
 792         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 793         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 794         bitmap_bh = read_inode_bitmap(sb, block_group);
 795         if (!bitmap_bh) {
 796                 ext4_warning(sb, __FUNCTION__,
 797                              "inode bitmap error for orphan %lu", ino);
 798                 goto out;
 799         }
 800
 801         /* Having the inode bit set should be a 100% indicator that this
 802          * is a valid orphan (no e2fsck run on fs).  Orphans also include
 803          * inodes that were being truncated, so we can't check i_nlink==0.
 804          */
 805         if (!ext4_test_bit(bit, bitmap_bh->b_data) ||
 806                         !(inode = iget(sb, ino)) || is_bad_inode(inode) ||
 807                         NEXT_ORPHAN(inode) > max_ino) {
 808                 ext4_warning(sb, __FUNCTION__,
 809                              "bad orphan inode %lu!  e2fsck was run?", ino);
 810                 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
 811                        bit, (unsigned long long)bitmap_bh->b_blocknr,
 812                        ext4_test_bit(bit, bitmap_bh->b_data));
 813                 printk(KERN_NOTICE "inode=%p\n", inode);
 814                 if (inode) {
 815                         printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 816                                is_bad_inode(inode));
 817                         printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 818                                NEXT_ORPHAN(inode));
 819                         printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 820                 }
 821                 /* Avoid freeing blocks if we got a bad deleted inode */
 822                 if (inode && inode->i_nlink == 0)
 823                         inode->i_blocks = 0;
 824                 iput(inode);
 825                 inode = NULL;
 826         }
 827 out:
 828         brelse(bitmap_bh);
 829         return inode;
 830 }
 831
 832 unsigned long ext4_count_free_inodes (struct super_block * sb)
 833 {
 834         unsigned long desc_count;
 835         struct ext4_group_desc *gdp;
 836         int i;
 837 #ifdef EXT4FS_DEBUG
 838         struct ext4_super_block *es;
 839         unsigned long bitmap_count, x;
 840         struct buffer_head *bitmap_bh = NULL;
 841
 842         es = EXT4_SB(sb)->s_es;
 843         desc_count = 0;
 844         bitmap_count = 0;
 845         gdp = NULL;
 846         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 847                 gdp = ext4_get_group_desc (sb, i, NULL);
 848                 if (!gdp)
 849                         continue;
 850                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 851                 brelse(bitmap_bh);
 852                 bitmap_bh = read_inode_bitmap(sb, i);
 853                 if (!bitmap_bh)
 854                         continue;
 855
 856                 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
 857                 printk("group %d: stored = %d, counted = %lu\n",
 858                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 859                 bitmap_count += x;
 860         }
 861         brelse(bitmap_bh);
 862         printk("ext4_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 863                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 864         return desc_count;
 865 #else
 866         desc_count = 0;
 867         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 868                 gdp = ext4_get_group_desc (sb, i, NULL);
 869                 if (!gdp)
 870                         continue;
 871                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 872                 cond_resched();
 873         }
 874         return desc_count;
 875 #endif
 876 }
 877
 878 /* Called at mount-time, super-block is locked */
 879 unsigned long ext4_count_dirs (struct super_block * sb)
 880 {
 881         unsigned long count = 0;
 882         int i;
 883
 884         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 885                 struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
 886                 if (!gdp)
 887                         continue;
 888                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 889         }
 890         return count;
 891 }
 892