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/stat.h>
  19 #include <linux/string.h>
  20 #include <linux/quotaops.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/random.h>
  23 #include <linux/bitops.h>
  24 #include <linux/blkdev.h>
  25 #include <asm/byteorder.h>
  26 #include "ext4.h"
  27 #include "ext4_jbd2.h"
  28 #include "xattr.h"
  29 #include "acl.h"
  30 #include "group.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  * To avoid calling the atomic setbit hundreds or thousands of times, we only
  48  * need to use it within a single byte (to ensure we get endianness right).
  49  * We can use memset for the rest of the bitmap as there are no other users.
  50  */
  51 void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
  52 {
  53         int i;
  54
  55         if (start_bit >= end_bit)
  56                 return;
  57
  58         ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
  59         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
  60                 ext4_set_bit(i, bitmap);
  61         if (i < end_bit)
  62                 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
  63 }
  64
  65 /* Initializes an uninitialized inode bitmap */
  66 unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh,
  67                                 ext4_group_t block_group,
  68                                 struct ext4_group_desc *gdp)
  69 {
  70         struct ext4_sb_info *sbi = EXT4_SB(sb);
  71
  72         J_ASSERT_BH(bh, buffer_locked(bh));
  73
  74         /* If checksum is bad mark all blocks and inodes use to prevent
  75          * allocation, essentially implementing a per-group read-only flag. */
  76         if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
  77                 ext4_error(sb, __func__, "Checksum bad for group %lu\n",
  78                            block_group);
  79                 gdp->bg_free_blocks_count = 0;
  80                 gdp->bg_free_inodes_count = 0;
  81                 gdp->bg_itable_unused = 0;
  82                 memset(bh->b_data, 0xff, sb->s_blocksize);
  83                 return 0;
  84         }
  85
  86         memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
  87         mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb),
  88                         bh->b_data);
  89
  90         return EXT4_INODES_PER_GROUP(sb);
  91 }
  92
  93 /*
  94  * Read the inode allocation bitmap for a given block_group, reading
  95  * into the specified slot in the superblock's bitmap cache.
  96  *
  97  * Return buffer_head of bitmap on success or NULL.
  98  */
  99 static struct buffer_head *
 100 read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 101 {
 102         struct ext4_group_desc *desc;
 103         struct buffer_head *bh = NULL;
 104
 105         desc = ext4_get_group_desc(sb, block_group, NULL);
 106         if (!desc)
 107                 goto error_out;
 108         if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 109                 bh = sb_getblk(sb, ext4_inode_bitmap(sb, desc));
 110                 if (!buffer_uptodate(bh)) {
 111                         lock_buffer(bh);
 112                         if (!buffer_uptodate(bh)) {
 113                                 ext4_init_inode_bitmap(sb, bh, block_group,
 114                                                        desc);
 115                                 set_buffer_uptodate(bh);
 116                         }
 117                         unlock_buffer(bh);
 118                 }
 119         } else {
 120                 bh = sb_bread(sb, ext4_inode_bitmap(sb, desc));
 121         }
 122         if (!bh)
 123                 ext4_error(sb, "read_inode_bitmap",
 124                             "Cannot read inode bitmap - "
 125                             "block_group = %lu, inode_bitmap = %llu",
 126                             block_group, ext4_inode_bitmap(sb, desc));
 127 error_out:
 128         return bh;
 129 }
 130
 131 /*
 132  * NOTE! When we get the inode, we're the only people
 133  * that have access to it, and as such there are no
 134  * race conditions we have to worry about. The inode
 135  * is not on the hash-lists, and it cannot be reached
 136  * through the filesystem because the directory entry
 137  * has been deleted earlier.
 138  *
 139  * HOWEVER: we must make sure that we get no aliases,
 140  * which means that we have to call "clear_inode()"
 141  * _before_ we mark the inode not in use in the inode
 142  * bitmaps. Otherwise a newly created file might use
 143  * the same inode number (not actually the same pointer
 144  * though), and then we'd have two inodes sharing the
 145  * same inode number and space on the harddisk.
 146  */
 147 void ext4_free_inode (handle_t *handle, struct inode * inode)
 148 {
 149         struct super_block * sb = inode->i_sb;
 150         int is_directory;
 151         unsigned long ino;
 152         struct buffer_head *bitmap_bh = NULL;
 153         struct buffer_head *bh2;
 154         ext4_group_t block_group;
 155         unsigned long bit;
 156         struct ext4_group_desc * gdp;
 157         struct ext4_super_block * es;
 158         struct ext4_sb_info *sbi;
 159         int fatal = 0, err;
 160
 161         if (atomic_read(&inode->i_count) > 1) {
 162                 printk ("ext4_free_inode: inode has count=%d\n",
 163                                         atomic_read(&inode->i_count));
 164                 return;
 165         }
 166         if (inode->i_nlink) {
 167                 printk ("ext4_free_inode: inode has nlink=%d\n",
 168                         inode->i_nlink);
 169                 return;
 170         }
 171         if (!sb) {
 172                 printk("ext4_free_inode: inode on nonexistent device\n");
 173                 return;
 174         }
 175         sbi = EXT4_SB(sb);
 176
 177         ino = inode->i_ino;
 178         ext4_debug ("freeing inode %lu\n", ino);
 179
 180         /*
 181          * Note: we must free any quota before locking the superblock,
 182          * as writing the quota to disk may need the lock as well.
 183          */
 184         DQUOT_INIT(inode);
 185         ext4_xattr_delete_inode(handle, inode);
 186         DQUOT_FREE_INODE(inode);
 187         DQUOT_DROP(inode);
 188
 189         is_directory = S_ISDIR(inode->i_mode);
 190
 191         /* Do this BEFORE marking the inode not in use or returning an error */
 192         clear_inode (inode);
 193
 194         es = EXT4_SB(sb)->s_es;
 195         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 196                 ext4_error (sb, "ext4_free_inode",
 197                             "reserved or nonexistent inode %lu", ino);
 198                 goto error_return;
 199         }
 200         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 201         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 202         bitmap_bh = read_inode_bitmap(sb, block_group);
 203         if (!bitmap_bh)
 204                 goto error_return;
 205
 206         BUFFER_TRACE(bitmap_bh, "get_write_access");
 207         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 208         if (fatal)
 209                 goto error_return;
 210
 211         /* Ok, now we can actually update the inode bitmaps.. */
 212         if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 213                                         bit, bitmap_bh->b_data))
 214                 ext4_error (sb, "ext4_free_inode",
 215                               "bit already cleared for inode %lu", ino);
 216         else {
 217                 gdp = ext4_get_group_desc (sb, block_group, &bh2);
 218
 219                 BUFFER_TRACE(bh2, "get_write_access");
 220                 fatal = ext4_journal_get_write_access(handle, bh2);
 221                 if (fatal) goto error_return;
 222
 223                 if (gdp) {
 224                         spin_lock(sb_bgl_lock(sbi, block_group));
 225                         le16_add_cpu(&gdp->bg_free_inodes_count, 1);
 226                         if (is_directory)
 227                                 le16_add_cpu(&gdp->bg_used_dirs_count, -1);
 228                         gdp->bg_checksum = ext4_group_desc_csum(sbi,
 229                                                         block_group, gdp);
 230                         spin_unlock(sb_bgl_lock(sbi, block_group));
 231                         percpu_counter_inc(&sbi->s_freeinodes_counter);
 232                         if (is_directory)
 233                                 percpu_counter_dec(&sbi->s_dirs_counter);
 234
 235                 }
 236                 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
 237                 err = ext4_journal_dirty_metadata(handle, bh2);
 238                 if (!fatal) fatal = err;
 239         }
 240         BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
 241         err = ext4_journal_dirty_metadata(handle, bitmap_bh);
 242         if (!fatal)
 243                 fatal = err;
 244         sb->s_dirt = 1;
 245 error_return:
 246         brelse(bitmap_bh);
 247         ext4_std_error(sb, fatal);
 248 }
 249
 250 /*
 251  * There are two policies for allocating an inode.  If the new inode is
 252  * a directory, then a forward search is made for a block group with both
 253  * free space and a low directory-to-inode ratio; if that fails, then of
 254  * the groups with above-average free space, that group with the fewest
 255  * directories already is chosen.
 256  *
 257  * For other inodes, search forward from the parent directory\'s block
 258  * group to find a free inode.
 259  */
 260 static int find_group_dir(struct super_block *sb, struct inode *parent,
 261                                 ext4_group_t *best_group)
 262 {
 263         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 264         unsigned int freei, avefreei;
 265         struct ext4_group_desc *desc, *best_desc = NULL;
 266         ext4_group_t group;
 267         int ret = -1;
 268
 269         freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
 270         avefreei = freei / ngroups;
 271
 272         for (group = 0; group < ngroups; group++) {
 273                 desc = ext4_get_group_desc (sb, group, NULL);
 274                 if (!desc || !desc->bg_free_inodes_count)
 275                         continue;
 276                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 277                         continue;
 278                 if (!best_desc ||
 279                     (le16_to_cpu(desc->bg_free_blocks_count) >
 280                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 281                         *best_group = group;
 282                         best_desc = desc;
 283                         ret = 0;
 284                 }
 285         }
 286         return ret;
 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 preferred, 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                                 ext4_group_t *group)
 319 {
 320         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 321         struct ext4_sb_info *sbi = EXT4_SB(sb);
 322         struct ext4_super_block *es = sbi->s_es;
 323         ext4_group_t ngroups = sbi->s_groups_count;
 324         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 325         unsigned int freei, avefreei;
 326         ext4_fsblk_t freeb, avefreeb;
 327         ext4_fsblk_t blocks_per_dir;
 328         unsigned int ndirs;
 329         int max_debt, max_dirs, min_inodes;
 330         ext4_grpblk_t min_blocks;
 331         ext4_group_t i;
 332         struct ext4_group_desc *desc;
 333
 334         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 335         avefreei = freei / ngroups;
 336         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 337         avefreeb = freeb;
 338         do_div(avefreeb, ngroups);
 339         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 340
 341         if ((parent == sb->s_root->d_inode) ||
 342             (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
 343                 int best_ndir = inodes_per_group;
 344                 ext4_group_t grp;
 345                 int ret = -1;
 346
 347                 get_random_bytes(&grp, sizeof(grp));
 348                 parent_group = (unsigned)grp % ngroups;
 349                 for (i = 0; i < ngroups; i++) {
 350                         grp = (parent_group + i) % ngroups;
 351                         desc = ext4_get_group_desc(sb, grp, NULL);
 352                         if (!desc || !desc->bg_free_inodes_count)
 353                                 continue;
 354                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 355                                 continue;
 356                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 357                                 continue;
 358                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 359                                 continue;
 360                         *group = grp;
 361                         ret = 0;
 362                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 363                 }
 364                 if (ret == 0)
 365                         return ret;
 366                 goto fallback;
 367         }
 368
 369         blocks_per_dir = ext4_blocks_count(es) - freeb;
 370         do_div(blocks_per_dir, ndirs);
 371
 372         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 373         min_inodes = avefreei - inodes_per_group / 4;
 374         min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
 375
 376         max_debt = EXT4_BLOCKS_PER_GROUP(sb);
 377         max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
 378         if (max_debt * INODE_COST > inodes_per_group)
 379                 max_debt = inodes_per_group / INODE_COST;
 380         if (max_debt > 255)
 381                 max_debt = 255;
 382         if (max_debt == 0)
 383                 max_debt = 1;
 384
 385         for (i = 0; i < ngroups; i++) {
 386                 *group = (parent_group + i) % ngroups;
 387                 desc = ext4_get_group_desc(sb, *group, NULL);
 388                 if (!desc || !desc->bg_free_inodes_count)
 389                         continue;
 390                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 391                         continue;
 392                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 393                         continue;
 394                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 395                         continue;
 396                 return 0;
 397         }
 398
 399 fallback:
 400         for (i = 0; i < ngroups; i++) {
 401                 *group = (parent_group + i) % ngroups;
 402                 desc = ext4_get_group_desc(sb, *group, NULL);
 403                 if (desc && desc->bg_free_inodes_count &&
 404                         le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 405                         return 0;
 406         }
 407
 408         if (avefreei) {
 409                 /*
 410                  * The free-inodes counter is approximate, and for really small
 411                  * filesystems the above test can fail to find any blockgroups
 412                  */
 413                 avefreei = 0;
 414                 goto fallback;
 415         }
 416
 417         return -1;
 418 }
 419
 420 static int find_group_other(struct super_block *sb, struct inode *parent,
 421                                 ext4_group_t *group)
 422 {
 423         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 424         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 425         struct ext4_group_desc *desc;
 426         ext4_group_t i;
 427
 428         /*
 429          * Try to place the inode in its parent directory
 430          */
 431         *group = parent_group;
 432         desc = ext4_get_group_desc(sb, *group, NULL);
 433         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 434                         le16_to_cpu(desc->bg_free_blocks_count))
 435                 return 0;
 436
 437         /*
 438          * We're going to place this inode in a different blockgroup from its
 439          * parent.  We want to cause files in a common directory to all land in
 440          * the same blockgroup.  But we want files which are in a different
 441          * directory which shares a blockgroup with our parent to land in a
 442          * different blockgroup.
 443          *
 444          * So add our directory's i_ino into the starting point for the hash.
 445          */
 446         *group = (*group + parent->i_ino) % ngroups;
 447
 448         /*
 449          * Use a quadratic hash to find a group with a free inode and some free
 450          * blocks.
 451          */
 452         for (i = 1; i < ngroups; i <<= 1) {
 453                 *group += i;
 454                 if (*group >= ngroups)
 455                         *group -= ngroups;
 456                 desc = ext4_get_group_desc(sb, *group, NULL);
 457                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 458                                 le16_to_cpu(desc->bg_free_blocks_count))
 459                         return 0;
 460         }
 461
 462         /*
 463          * That failed: try linear search for a free inode, even if that group
 464          * has no free blocks.
 465          */
 466         *group = parent_group;
 467         for (i = 0; i < ngroups; i++) {
 468                 if (++*group >= ngroups)
 469                         *group = 0;
 470                 desc = ext4_get_group_desc(sb, *group, NULL);
 471                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 472                         return 0;
 473         }
 474
 475         return -1;
 476 }
 477
 478 /*
 479  * There are two policies for allocating an inode.  If the new inode is
 480  * a directory, then a forward search is made for a block group with both
 481  * free space and a low directory-to-inode ratio; if that fails, then of
 482  * the groups with above-average free space, that group with the fewest
 483  * directories already is chosen.
 484  *
 485  * For other inodes, search forward from the parent directory's block
 486  * group to find a free inode.
 487  */
 488 struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 489 {
 490         struct super_block *sb;
 491         struct buffer_head *bitmap_bh = NULL;
 492         struct buffer_head *bh2;
 493         ext4_group_t group = 0;
 494         unsigned long ino = 0;
 495         struct inode * inode;
 496         struct ext4_group_desc * gdp = NULL;
 497         struct ext4_super_block * es;
 498         struct ext4_inode_info *ei;
 499         struct ext4_sb_info *sbi;
 500         int ret2, err = 0;
 501         struct inode *ret;
 502         ext4_group_t i;
 503         int free = 0;
 504
 505         /* Cannot create files in a deleted directory */
 506         if (!dir || !dir->i_nlink)
 507                 return ERR_PTR(-EPERM);
 508
 509         sb = dir->i_sb;
 510         inode = new_inode(sb);
 511         if (!inode)
 512                 return ERR_PTR(-ENOMEM);
 513         ei = EXT4_I(inode);
 514
 515         sbi = EXT4_SB(sb);
 516         es = sbi->s_es;
 517         if (S_ISDIR(mode)) {
 518                 if (test_opt (sb, OLDALLOC))
 519                         ret2 = find_group_dir(sb, dir, &group);
 520                 else
 521                         ret2 = find_group_orlov(sb, dir, &group);
 522         } else
 523                 ret2 = find_group_other(sb, dir, &group);
 524
 525         err = -ENOSPC;
 526         if (ret2 == -1)
 527                 goto out;
 528
 529         for (i = 0; i < sbi->s_groups_count; i++) {
 530                 err = -EIO;
 531
 532                 gdp = ext4_get_group_desc(sb, group, &bh2);
 533                 if (!gdp)
 534                         goto fail;
 535
 536                 brelse(bitmap_bh);
 537                 bitmap_bh = read_inode_bitmap(sb, group);
 538                 if (!bitmap_bh)
 539                         goto fail;
 540
 541                 ino = 0;
 542
 543 repeat_in_this_group:
 544                 ino = ext4_find_next_zero_bit((unsigned long *)
 545                                 bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
 546                 if (ino < EXT4_INODES_PER_GROUP(sb)) {
 547
 548                         BUFFER_TRACE(bitmap_bh, "get_write_access");
 549                         err = ext4_journal_get_write_access(handle, bitmap_bh);
 550                         if (err)
 551                                 goto fail;
 552
 553                         if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
 554                                                 ino, bitmap_bh->b_data)) {
 555                                 /* we won it */
 556                                 BUFFER_TRACE(bitmap_bh,
 557                                         "call ext4_journal_dirty_metadata");
 558                                 err = ext4_journal_dirty_metadata(handle,
 559                                                                 bitmap_bh);
 560                                 if (err)
 561                                         goto fail;
 562                                 goto got;
 563                         }
 564                         /* we lost it */
 565                         jbd2_journal_release_buffer(handle, bitmap_bh);
 566
 567                         if (++ino < EXT4_INODES_PER_GROUP(sb))
 568                                 goto repeat_in_this_group;
 569                 }
 570
 571                 /*
 572                  * This case is possible in concurrent environment.  It is very
 573                  * rare.  We cannot repeat the find_group_xxx() call because
 574                  * that will simply return the same blockgroup, because the
 575                  * group descriptor metadata has not yet been updated.
 576                  * So we just go onto the next blockgroup.
 577                  */
 578                 if (++group == sbi->s_groups_count)
 579                         group = 0;
 580         }
 581         err = -ENOSPC;
 582         goto out;
 583
 584 got:
 585         ino++;
 586         if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
 587             ino > EXT4_INODES_PER_GROUP(sb)) {
 588                 ext4_error(sb, __func__,
 589                            "reserved inode or inode > inodes count - "
 590                            "block_group = %lu, inode=%lu", group,
 591                            ino + group * EXT4_INODES_PER_GROUP(sb));
 592                 err = -EIO;
 593                 goto fail;
 594         }
 595
 596         BUFFER_TRACE(bh2, "get_write_access");
 597         err = ext4_journal_get_write_access(handle, bh2);
 598         if (err) goto fail;
 599
 600         /* We may have to initialize the block bitmap if it isn't already */
 601         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 602             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 603                 struct buffer_head *block_bh = read_block_bitmap(sb, group);
 604
 605                 BUFFER_TRACE(block_bh, "get block bitmap access");
 606                 err = ext4_journal_get_write_access(handle, block_bh);
 607                 if (err) {
 608                         brelse(block_bh);
 609                         goto fail;
 610                 }
 611
 612                 free = 0;
 613                 spin_lock(sb_bgl_lock(sbi, group));
 614                 /* recheck and clear flag under lock if we still need to */
 615                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 616                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 617                         free = ext4_free_blocks_after_init(sb, group, gdp);
 618                         gdp->bg_free_blocks_count = cpu_to_le16(free);
 619                 }
 620                 spin_unlock(sb_bgl_lock(sbi, group));
 621
 622                 /* Don't need to dirty bitmap block if we didn't change it */
 623                 if (free) {
 624                         BUFFER_TRACE(block_bh, "dirty block bitmap");
 625                         err = ext4_journal_dirty_metadata(handle, block_bh);
 626                 }
 627
 628                 brelse(block_bh);
 629                 if (err)
 630                         goto fail;
 631         }
 632
 633         spin_lock(sb_bgl_lock(sbi, group));
 634         /* If we didn't allocate from within the initialized part of the inode
 635          * table then we need to initialize up to this inode. */
 636         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 637                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 638                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
 639
 640                         /* When marking the block group with
 641                          * ~EXT4_BG_INODE_UNINIT we don't want to depend
 642                          * on the value of bg_itable_unsed even though
 643                          * mke2fs could have initialized the same for us.
 644                          * Instead we calculated the value below
 645                          */
 646
 647                         free = 0;
 648                 } else {
 649                         free = EXT4_INODES_PER_GROUP(sb) -
 650                                 le16_to_cpu(gdp->bg_itable_unused);
 651                 }
 652
 653                 /*
 654                  * Check the relative inode number against the last used
 655                  * relative inode number in this group. if it is greater
 656                  * we need to  update the bg_itable_unused count
 657                  *
 658                  */
 659                 if (ino > free)
 660                         gdp->bg_itable_unused =
 661                                 cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
 662         }
 663
 664         le16_add_cpu(&gdp->bg_free_inodes_count, -1);
 665         if (S_ISDIR(mode)) {
 666                 le16_add_cpu(&gdp->bg_used_dirs_count, 1);
 667         }
 668         gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
 669         spin_unlock(sb_bgl_lock(sbi, group));
 670         BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
 671         err = ext4_journal_dirty_metadata(handle, bh2);
 672         if (err) goto fail;
 673
 674         percpu_counter_dec(&sbi->s_freeinodes_counter);
 675         if (S_ISDIR(mode))
 676                 percpu_counter_inc(&sbi->s_dirs_counter);
 677         sb->s_dirt = 1;
 678
 679         inode->i_uid = current->fsuid;
 680         if (test_opt (sb, GRPID))
 681                 inode->i_gid = dir->i_gid;
 682         else if (dir->i_mode & S_ISGID) {
 683                 inode->i_gid = dir->i_gid;
 684                 if (S_ISDIR(mode))
 685                         mode |= S_ISGID;
 686         } else
 687                 inode->i_gid = current->fsgid;
 688         inode->i_mode = mode;
 689
 690         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
 691         /* This is the optimal IO size (for stat), not the fs block size */
 692         inode->i_blocks = 0;
 693         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
 694                                                        ext4_current_time(inode);
 695
 696         memset(ei->i_data, 0, sizeof(ei->i_data));
 697         ei->i_dir_start_lookup = 0;
 698         ei->i_disksize = 0;
 699
 700         /*
 701          * Don't inherit extent flag from directory. We set extent flag on
 702          * newly created directory and file only if -o extent mount option is
 703          * specified
 704          */
 705         ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL);
 706         if (S_ISLNK(mode))
 707                 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
 708         /* dirsync only applies to directories */
 709         if (!S_ISDIR(mode))
 710                 ei->i_flags &= ~EXT4_DIRSYNC_FL;
 711         ei->i_file_acl = 0;
 712         ei->i_dtime = 0;
 713         ei->i_block_alloc_info = NULL;
 714         ei->i_block_group = group;
 715
 716         ext4_set_inode_flags(inode);
 717         if (IS_DIRSYNC(inode))
 718                 handle->h_sync = 1;
 719         insert_inode_hash(inode);
 720         spin_lock(&sbi->s_next_gen_lock);
 721         inode->i_generation = sbi->s_next_generation++;
 722         spin_unlock(&sbi->s_next_gen_lock);
 723
 724         ei->i_state = EXT4_STATE_NEW;
 725
 726         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
 727
 728         ret = inode;
 729         if(DQUOT_ALLOC_INODE(inode)) {
 730                 err = -EDQUOT;
 731                 goto fail_drop;
 732         }
 733
 734         err = ext4_init_acl(handle, inode, dir);
 735         if (err)
 736                 goto fail_free_drop;
 737
 738         err = ext4_init_security(handle,inode, dir);
 739         if (err)
 740                 goto fail_free_drop;
 741
 742         if (test_opt(sb, EXTENTS)) {
 743                 /* set extent flag only for diretory, file and normal symlink*/
 744                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
 745                         EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
 746                         ext4_ext_tree_init(handle, inode);
 747                         err = ext4_update_incompat_feature(handle, sb,
 748                                         EXT4_FEATURE_INCOMPAT_EXTENTS);
 749                         if (err)
 750                                 goto fail_free_drop;
 751                 }
 752         }
 753
 754         err = ext4_mark_inode_dirty(handle, inode);
 755         if (err) {
 756                 ext4_std_error(sb, err);
 757                 goto fail_free_drop;
 758         }
 759
 760         ext4_debug("allocating inode %lu\n", inode->i_ino);
 761         goto really_out;
 762 fail:
 763         ext4_std_error(sb, err);
 764 out:
 765         iput(inode);
 766         ret = ERR_PTR(err);
 767 really_out:
 768         brelse(bitmap_bh);
 769         return ret;
 770
 771 fail_free_drop:
 772         DQUOT_FREE_INODE(inode);
 773
 774 fail_drop:
 775         DQUOT_DROP(inode);
 776         inode->i_flags |= S_NOQUOTA;
 777         inode->i_nlink = 0;
 778         iput(inode);
 779         brelse(bitmap_bh);
 780         return ERR_PTR(err);
 781 }
 782
 783 /* Verify that we are loading a valid orphan from disk */
 784 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 785 {
 786         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 787         ext4_group_t block_group;
 788         int bit;
 789         struct buffer_head *bitmap_bh;
 790         struct inode *inode = NULL;
 791         long err = -EIO;
 792
 793         /* Error cases - e2fsck has already cleaned up for us */
 794         if (ino > max_ino) {
 795                 ext4_warning(sb, __func__,
 796                              "bad orphan ino %lu!  e2fsck was run?", ino);
 797                 goto error;
 798         }
 799
 800         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 801         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 802         bitmap_bh = read_inode_bitmap(sb, block_group);
 803         if (!bitmap_bh) {
 804                 ext4_warning(sb, __func__,
 805                              "inode bitmap error for orphan %lu", ino);
 806                 goto error;
 807         }
 808
 809         /* Having the inode bit set should be a 100% indicator that this
 810          * is a valid orphan (no e2fsck run on fs).  Orphans also include
 811          * inodes that were being truncated, so we can't check i_nlink==0.
 812          */
 813         if (!ext4_test_bit(bit, bitmap_bh->b_data))
 814                 goto bad_orphan;
 815
 816         inode = ext4_iget(sb, ino);
 817         if (IS_ERR(inode))
 818                 goto iget_failed;
 819
 820         if (NEXT_ORPHAN(inode) > max_ino)
 821                 goto bad_orphan;
 822         brelse(bitmap_bh);
 823         return inode;
 824
 825 iget_failed:
 826         err = PTR_ERR(inode);
 827         inode = NULL;
 828 bad_orphan:
 829         ext4_warning(sb, __func__,
 830                      "bad orphan inode %lu!  e2fsck was run?", ino);
 831         printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
 832                bit, (unsigned long long)bitmap_bh->b_blocknr,
 833                ext4_test_bit(bit, bitmap_bh->b_data));
 834         printk(KERN_NOTICE "inode=%p\n", inode);
 835         if (inode) {
 836                 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 837                        is_bad_inode(inode));
 838                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 839                        NEXT_ORPHAN(inode));
 840                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 841                 /* Avoid freeing blocks if we got a bad deleted inode */
 842                 if (inode->i_nlink == 0)
 843                         inode->i_blocks = 0;
 844                 iput(inode);
 845         }
 846         brelse(bitmap_bh);
 847 error:
 848         return ERR_PTR(err);
 849 }
 850
 851 unsigned long ext4_count_free_inodes (struct super_block * sb)
 852 {
 853         unsigned long desc_count;
 854         struct ext4_group_desc *gdp;
 855         ext4_group_t i;
 856 #ifdef EXT4FS_DEBUG
 857         struct ext4_super_block *es;
 858         unsigned long bitmap_count, x;
 859         struct buffer_head *bitmap_bh = NULL;
 860
 861         es = EXT4_SB(sb)->s_es;
 862         desc_count = 0;
 863         bitmap_count = 0;
 864         gdp = NULL;
 865         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 866                 gdp = ext4_get_group_desc (sb, i, NULL);
 867                 if (!gdp)
 868                         continue;
 869                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 870                 brelse(bitmap_bh);
 871                 bitmap_bh = read_inode_bitmap(sb, i);
 872                 if (!bitmap_bh)
 873                         continue;
 874
 875                 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
 876                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
 877                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 878                 bitmap_count += x;
 879         }
 880         brelse(bitmap_bh);
 881         printk("ext4_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 882                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 883         return desc_count;
 884 #else
 885         desc_count = 0;
 886         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 887                 gdp = ext4_get_group_desc (sb, i, NULL);
 888                 if (!gdp)
 889                         continue;
 890                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 891                 cond_resched();
 892         }
 893         return desc_count;
 894 #endif
 895 }
 896
 897 /* Called at mount-time, super-block is locked */
 898 unsigned long ext4_count_dirs (struct super_block * sb)
 899 {
 900         unsigned long count = 0;
 901         ext4_group_t i;
 902
 903         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 904                 struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
 905                 if (!gdp)
 906                         continue;
 907                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 908         }
 909         return count;
 910 }
 911