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, struct buffer_head *bh,
  68                                 ext4_group_t 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 %lu\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, ext4_group_t 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         ext4_group_t 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                                 ext4_group_t *best_group)
 265 {
 266         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 267         unsigned int freei, avefreei;
 268         struct ext4_group_desc *desc, *best_desc = NULL;
 269         ext4_group_t group;
 270         int ret = -1;
 271
 272         freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
 273         avefreei = freei / ngroups;
 274
 275         for (group = 0; group < ngroups; group++) {
 276                 desc = ext4_get_group_desc (sb, group, NULL);
 277                 if (!desc || !desc->bg_free_inodes_count)
 278                         continue;
 279                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 280                         continue;
 281                 if (!best_desc ||
 282                     (le16_to_cpu(desc->bg_free_blocks_count) >
 283                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
 284                         *best_group = group;
 285                         best_desc = desc;
 286                         ret = 0;
 287                 }
 288         }
 289         return ret;
 290 }
 291
 292 /*
 293  * Orlov's allocator for directories.
 294  *
 295  * We always try to spread first-level directories.
 296  *
 297  * If there are blockgroups with both free inodes and free blocks counts
 298  * not worse than average we return one with smallest directory count.
 299  * Otherwise we simply return a random group.
 300  *
 301  * For the rest rules look so:
 302  *
 303  * It's OK to put directory into a group unless
 304  * it has too many directories already (max_dirs) or
 305  * it has too few free inodes left (min_inodes) or
 306  * it has too few free blocks left (min_blocks) or
 307  * it's already running too large debt (max_debt).
 308  * Parent's group is prefered, if it doesn't satisfy these
 309  * conditions we search cyclically through the rest. If none
 310  * of the groups look good we just look for a group with more
 311  * free inodes than average (starting at parent's group).
 312  *
 313  * Debt is incremented each time we allocate a directory and decremented
 314  * when we allocate an inode, within 0--255.
 315  */
 316
 317 #define INODE_COST 64
 318 #define BLOCK_COST 256
 319
 320 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 321                                 ext4_group_t *group)
 322 {
 323         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 324         struct ext4_sb_info *sbi = EXT4_SB(sb);
 325         struct ext4_super_block *es = sbi->s_es;
 326         ext4_group_t ngroups = sbi->s_groups_count;
 327         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 328         unsigned int freei, avefreei;
 329         ext4_fsblk_t freeb, avefreeb;
 330         ext4_fsblk_t blocks_per_dir;
 331         unsigned int ndirs;
 332         int max_debt, max_dirs, min_inodes;
 333         ext4_grpblk_t min_blocks;
 334         ext4_group_t i;
 335         struct ext4_group_desc *desc;
 336
 337         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 338         avefreei = freei / ngroups;
 339         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 340         avefreeb = freeb;
 341         do_div(avefreeb, ngroups);
 342         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 343
 344         if ((parent == sb->s_root->d_inode) ||
 345             (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
 346                 int best_ndir = inodes_per_group;
 347                 ext4_group_t grp;
 348                 int ret = -1;
 349
 350                 get_random_bytes(&grp, sizeof(grp));
 351                 parent_group = (unsigned)grp % ngroups;
 352                 for (i = 0; i < ngroups; i++) {
 353                         grp = (parent_group + i) % ngroups;
 354                         desc = ext4_get_group_desc(sb, grp, NULL);
 355                         if (!desc || !desc->bg_free_inodes_count)
 356                                 continue;
 357                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
 358                                 continue;
 359                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
 360                                 continue;
 361                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
 362                                 continue;
 363                         *group = grp;
 364                         ret = 0;
 365                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
 366                 }
 367                 if (ret == 0)
 368                         return ret;
 369                 goto fallback;
 370         }
 371
 372         blocks_per_dir = ext4_blocks_count(es) - freeb;
 373         do_div(blocks_per_dir, ndirs);
 374
 375         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 376         min_inodes = avefreei - inodes_per_group / 4;
 377         min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
 378
 379         max_debt = EXT4_BLOCKS_PER_GROUP(sb);
 380         max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
 381         if (max_debt * INODE_COST > inodes_per_group)
 382                 max_debt = inodes_per_group / INODE_COST;
 383         if (max_debt > 255)
 384                 max_debt = 255;
 385         if (max_debt == 0)
 386                 max_debt = 1;
 387
 388         for (i = 0; i < ngroups; i++) {
 389                 *group = (parent_group + i) % ngroups;
 390                 desc = ext4_get_group_desc(sb, *group, NULL);
 391                 if (!desc || !desc->bg_free_inodes_count)
 392                         continue;
 393                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
 394                         continue;
 395                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
 396                         continue;
 397                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
 398                         continue;
 399                 return 0;
 400         }
 401
 402 fallback:
 403         for (i = 0; i < ngroups; i++) {
 404                 *group = (parent_group + i) % ngroups;
 405                 desc = ext4_get_group_desc(sb, *group, NULL);
 406                 if (desc && desc->bg_free_inodes_count &&
 407                         le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
 408                         return 0;
 409         }
 410
 411         if (avefreei) {
 412                 /*
 413                  * The free-inodes counter is approximate, and for really small
 414                  * filesystems the above test can fail to find any blockgroups
 415                  */
 416                 avefreei = 0;
 417                 goto fallback;
 418         }
 419
 420         return -1;
 421 }
 422
 423 static int find_group_other(struct super_block *sb, struct inode *parent,
 424                                 ext4_group_t *group)
 425 {
 426         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 427         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 428         struct ext4_group_desc *desc;
 429         ext4_group_t i;
 430
 431         /*
 432          * Try to place the inode in its parent directory
 433          */
 434         *group = parent_group;
 435         desc = ext4_get_group_desc(sb, *group, NULL);
 436         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 437                         le16_to_cpu(desc->bg_free_blocks_count))
 438                 return 0;
 439
 440         /*
 441          * We're going to place this inode in a different blockgroup from its
 442          * parent.  We want to cause files in a common directory to all land in
 443          * the same blockgroup.  But we want files which are in a different
 444          * directory which shares a blockgroup with our parent to land in a
 445          * different blockgroup.
 446          *
 447          * So add our directory's i_ino into the starting point for the hash.
 448          */
 449         *group = (*group + parent->i_ino) % ngroups;
 450
 451         /*
 452          * Use a quadratic hash to find a group with a free inode and some free
 453          * blocks.
 454          */
 455         for (i = 1; i < ngroups; i <<= 1) {
 456                 *group += i;
 457                 if (*group >= ngroups)
 458                         *group -= ngroups;
 459                 desc = ext4_get_group_desc(sb, *group, NULL);
 460                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
 461                                 le16_to_cpu(desc->bg_free_blocks_count))
 462                         return 0;
 463         }
 464
 465         /*
 466          * That failed: try linear search for a free inode, even if that group
 467          * has no free blocks.
 468          */
 469         *group = parent_group;
 470         for (i = 0; i < ngroups; i++) {
 471                 if (++*group >= ngroups)
 472                         *group = 0;
 473                 desc = ext4_get_group_desc(sb, *group, NULL);
 474                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
 475                         return 0;
 476         }
 477
 478         return -1;
 479 }
 480
 481 /*
 482  * There are two policies for allocating an inode.  If the new inode is
 483  * a directory, then a forward search is made for a block group with both
 484  * free space and a low directory-to-inode ratio; if that fails, then of
 485  * the groups with above-average free space, that group with the fewest
 486  * directories already is chosen.
 487  *
 488  * For other inodes, search forward from the parent directory's block
 489  * group to find a free inode.
 490  */
 491 struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 492 {
 493         struct super_block *sb;
 494         struct buffer_head *bitmap_bh = NULL;
 495         struct buffer_head *bh2;
 496         ext4_group_t group = 0;
 497         unsigned long ino = 0;
 498         struct inode * inode;
 499         struct ext4_group_desc * gdp = NULL;
 500         struct ext4_super_block * es;
 501         struct ext4_inode_info *ei;
 502         struct ext4_sb_info *sbi;
 503         int ret2, err = 0;
 504         struct inode *ret;
 505         ext4_group_t i;
 506         int free = 0;
 507
 508         /* Cannot create files in a deleted directory */
 509         if (!dir || !dir->i_nlink)
 510                 return ERR_PTR(-EPERM);
 511
 512         sb = dir->i_sb;
 513         inode = new_inode(sb);
 514         if (!inode)
 515                 return ERR_PTR(-ENOMEM);
 516         ei = EXT4_I(inode);
 517
 518         sbi = EXT4_SB(sb);
 519         es = sbi->s_es;
 520         if (S_ISDIR(mode)) {
 521                 if (test_opt (sb, OLDALLOC))
 522                         ret2 = find_group_dir(sb, dir, &group);
 523                 else
 524                         ret2 = find_group_orlov(sb, dir, &group);
 525         } else
 526                 ret2 = find_group_other(sb, dir, &group);
 527
 528         err = -ENOSPC;
 529         if (ret2 == -1)
 530                 goto out;
 531
 532         for (i = 0; i < sbi->s_groups_count; i++) {
 533                 err = -EIO;
 534
 535                 gdp = ext4_get_group_desc(sb, group, &bh2);
 536                 if (!gdp)
 537                         goto fail;
 538
 539                 brelse(bitmap_bh);
 540                 bitmap_bh = read_inode_bitmap(sb, group);
 541                 if (!bitmap_bh)
 542                         goto fail;
 543
 544                 ino = 0;
 545
 546 repeat_in_this_group:
 547                 ino = ext4_find_next_zero_bit((unsigned long *)
 548                                 bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
 549                 if (ino < EXT4_INODES_PER_GROUP(sb)) {
 550
 551                         BUFFER_TRACE(bitmap_bh, "get_write_access");
 552                         err = ext4_journal_get_write_access(handle, bitmap_bh);
 553                         if (err)
 554                                 goto fail;
 555
 556                         if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
 557                                                 ino, bitmap_bh->b_data)) {
 558                                 /* we won it */
 559                                 BUFFER_TRACE(bitmap_bh,
 560                                         "call ext4_journal_dirty_metadata");
 561                                 err = ext4_journal_dirty_metadata(handle,
 562                                                                 bitmap_bh);
 563                                 if (err)
 564                                         goto fail;
 565                                 goto got;
 566                         }
 567                         /* we lost it */
 568                         jbd2_journal_release_buffer(handle, bitmap_bh);
 569
 570                         if (++ino < EXT4_INODES_PER_GROUP(sb))
 571                                 goto repeat_in_this_group;
 572                 }
 573
 574                 /*
 575                  * This case is possible in concurrent environment.  It is very
 576                  * rare.  We cannot repeat the find_group_xxx() call because
 577                  * that will simply return the same blockgroup, because the
 578                  * group descriptor metadata has not yet been updated.
 579                  * So we just go onto the next blockgroup.
 580                  */
 581                 if (++group == sbi->s_groups_count)
 582                         group = 0;
 583         }
 584         err = -ENOSPC;
 585         goto out;
 586
 587 got:
 588         ino++;
 589         if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
 590             ino > EXT4_INODES_PER_GROUP(sb)) {
 591                 ext4_error(sb, __FUNCTION__,
 592                            "reserved inode or inode > inodes count - "
 593                            "block_group = %lu, inode=%lu", group,
 594                            ino + group * EXT4_INODES_PER_GROUP(sb));
 595                 err = -EIO;
 596                 goto fail;
 597         }
 598
 599         BUFFER_TRACE(bh2, "get_write_access");
 600         err = ext4_journal_get_write_access(handle, bh2);
 601         if (err) goto fail;
 602
 603         /* We may have to initialize the block bitmap if it isn't already */
 604         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 605             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 606                 struct buffer_head *block_bh = read_block_bitmap(sb, group);
 607
 608                 BUFFER_TRACE(block_bh, "get block bitmap access");
 609                 err = ext4_journal_get_write_access(handle, block_bh);
 610                 if (err) {
 611                         brelse(block_bh);
 612                         goto fail;
 613                 }
 614
 615                 free = 0;
 616                 spin_lock(sb_bgl_lock(sbi, group));
 617                 /* recheck and clear flag under lock if we still need to */
 618                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 619                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 620                         free = ext4_free_blocks_after_init(sb, group, gdp);
 621                         gdp->bg_free_blocks_count = cpu_to_le16(free);
 622                 }
 623                 spin_unlock(sb_bgl_lock(sbi, group));
 624
 625                 /* Don't need to dirty bitmap block if we didn't change it */
 626                 if (free) {
 627                         BUFFER_TRACE(block_bh, "dirty block bitmap");
 628                         err = ext4_journal_dirty_metadata(handle, block_bh);
 629                 }
 630
 631                 brelse(block_bh);
 632                 if (err)
 633                         goto fail;
 634         }
 635
 636         spin_lock(sb_bgl_lock(sbi, group));
 637         /* If we didn't allocate from within the initialized part of the inode
 638          * table then we need to initialize up to this inode. */
 639         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 640                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 641                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
 642
 643                         /* When marking the block group with
 644                          * ~EXT4_BG_INODE_UNINIT we don't want to depend
 645                          * on the value of bg_itable_unsed even though
 646                          * mke2fs could have initialized the same for us.
 647                          * Instead we calculated the value below
 648                          */
 649
 650                         free = 0;
 651                 } else {
 652                         free = EXT4_INODES_PER_GROUP(sb) -
 653                                 le16_to_cpu(gdp->bg_itable_unused);
 654                 }
 655
 656                 /*
 657                  * Check the relative inode number against the last used
 658                  * relative inode number in this group. if it is greater
 659                  * we need to  update the bg_itable_unused count
 660                  *
 661                  */
 662                 if (ino > free)
 663                         gdp->bg_itable_unused =
 664                                 cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
 665         }
 666
 667         gdp->bg_free_inodes_count =
 668                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
 669         if (S_ISDIR(mode)) {
 670                 gdp->bg_used_dirs_count =
 671                         cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
 672         }
 673         gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
 674         spin_unlock(sb_bgl_lock(sbi, group));
 675         BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
 676         err = ext4_journal_dirty_metadata(handle, bh2);
 677         if (err) goto fail;
 678
 679         percpu_counter_dec(&sbi->s_freeinodes_counter);
 680         if (S_ISDIR(mode))
 681                 percpu_counter_inc(&sbi->s_dirs_counter);
 682         sb->s_dirt = 1;
 683
 684         inode->i_uid = current->fsuid;
 685         if (test_opt (sb, GRPID))
 686                 inode->i_gid = dir->i_gid;
 687         else if (dir->i_mode & S_ISGID) {
 688                 inode->i_gid = dir->i_gid;
 689                 if (S_ISDIR(mode))
 690                         mode |= S_ISGID;
 691         } else
 692                 inode->i_gid = current->fsgid;
 693         inode->i_mode = mode;
 694
 695         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
 696         /* This is the optimal IO size (for stat), not the fs block size */
 697         inode->i_blocks = 0;
 698         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
 699                                                        ext4_current_time(inode);
 700
 701         memset(ei->i_data, 0, sizeof(ei->i_data));
 702         ei->i_dir_start_lookup = 0;
 703         ei->i_disksize = 0;
 704
 705         /*
 706          * Don't inherit extent flag from directory. We set extent flag on
 707          * newly created directory and file only if -o extent mount option is
 708          * specified
 709          */
 710         ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL);
 711         if (S_ISLNK(mode))
 712                 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
 713         /* dirsync only applies to directories */
 714         if (!S_ISDIR(mode))
 715                 ei->i_flags &= ~EXT4_DIRSYNC_FL;
 716         ei->i_file_acl = 0;
 717         ei->i_dtime = 0;
 718         ei->i_block_alloc_info = NULL;
 719         ei->i_block_group = group;
 720
 721         ext4_set_inode_flags(inode);
 722         if (IS_DIRSYNC(inode))
 723                 handle->h_sync = 1;
 724         insert_inode_hash(inode);
 725         spin_lock(&sbi->s_next_gen_lock);
 726         inode->i_generation = sbi->s_next_generation++;
 727         spin_unlock(&sbi->s_next_gen_lock);
 728
 729         ei->i_state = EXT4_STATE_NEW;
 730
 731         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
 732
 733         ret = inode;
 734         if(DQUOT_ALLOC_INODE(inode)) {
 735                 err = -EDQUOT;
 736                 goto fail_drop;
 737         }
 738
 739         err = ext4_init_acl(handle, inode, dir);
 740         if (err)
 741                 goto fail_free_drop;
 742
 743         err = ext4_init_security(handle,inode, dir);
 744         if (err)
 745                 goto fail_free_drop;
 746
 747         err = ext4_mark_inode_dirty(handle, inode);
 748         if (err) {
 749                 ext4_std_error(sb, err);
 750                 goto fail_free_drop;
 751         }
 752         if (test_opt(sb, EXTENTS)) {
 753                 /* set extent flag only for directory and file */
 754                 if (S_ISDIR(mode) || S_ISREG(mode)) {
 755                         EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
 756                         ext4_ext_tree_init(handle, inode);
 757                         err = ext4_update_incompat_feature(handle, sb,
 758                                         EXT4_FEATURE_INCOMPAT_EXTENTS);
 759                         if (err)
 760                                 goto fail;
 761                 }
 762         }
 763
 764         ext4_debug("allocating inode %lu\n", inode->i_ino);
 765         goto really_out;
 766 fail:
 767         ext4_std_error(sb, err);
 768 out:
 769         iput(inode);
 770         ret = ERR_PTR(err);
 771 really_out:
 772         brelse(bitmap_bh);
 773         return ret;
 774
 775 fail_free_drop:
 776         DQUOT_FREE_INODE(inode);
 777
 778 fail_drop:
 779         DQUOT_DROP(inode);
 780         inode->i_flags |= S_NOQUOTA;
 781         inode->i_nlink = 0;
 782         iput(inode);
 783         brelse(bitmap_bh);
 784         return ERR_PTR(err);
 785 }
 786
 787 /* Verify that we are loading a valid orphan from disk */
 788 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 789 {
 790         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 791         ext4_group_t block_group;
 792         int bit;
 793         struct buffer_head *bitmap_bh;
 794         struct inode *inode = NULL;
 795         long err = -EIO;
 796
 797         /* Error cases - e2fsck has already cleaned up for us */
 798         if (ino > max_ino) {
 799                 ext4_warning(sb, __FUNCTION__,
 800                              "bad orphan ino %lu!  e2fsck was run?", ino);
 801                 goto error;
 802         }
 803
 804         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 805         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 806         bitmap_bh = read_inode_bitmap(sb, block_group);
 807         if (!bitmap_bh) {
 808                 ext4_warning(sb, __FUNCTION__,
 809                              "inode bitmap error for orphan %lu", ino);
 810                 goto error;
 811         }
 812
 813         /* Having the inode bit set should be a 100% indicator that this
 814          * is a valid orphan (no e2fsck run on fs).  Orphans also include
 815          * inodes that were being truncated, so we can't check i_nlink==0.
 816          */
 817         if (!ext4_test_bit(bit, bitmap_bh->b_data))
 818                 goto bad_orphan;
 819
 820         inode = ext4_iget(sb, ino);
 821         if (IS_ERR(inode))
 822                 goto iget_failed;
 823
 824         if (NEXT_ORPHAN(inode) > max_ino)
 825                 goto bad_orphan;
 826         brelse(bitmap_bh);
 827         return inode;
 828
 829 iget_failed:
 830         err = PTR_ERR(inode);
 831         inode = NULL;
 832 bad_orphan:
 833         ext4_warning(sb, __FUNCTION__,
 834                      "bad orphan inode %lu!  e2fsck was run?", ino);
 835         printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
 836                bit, (unsigned long long)bitmap_bh->b_blocknr,
 837                ext4_test_bit(bit, bitmap_bh->b_data));
 838         printk(KERN_NOTICE "inode=%p\n", inode);
 839         if (inode) {
 840                 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
 841                        is_bad_inode(inode));
 842                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
 843                        NEXT_ORPHAN(inode));
 844                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
 845                 /* Avoid freeing blocks if we got a bad deleted inode */
 846                 if (inode->i_nlink == 0)
 847                         inode->i_blocks = 0;
 848                 iput(inode);
 849         }
 850         brelse(bitmap_bh);
 851 error:
 852         return ERR_PTR(err);
 853 }
 854
 855 unsigned long ext4_count_free_inodes (struct super_block * sb)
 856 {
 857         unsigned long desc_count;
 858         struct ext4_group_desc *gdp;
 859         ext4_group_t i;
 860 #ifdef EXT4FS_DEBUG
 861         struct ext4_super_block *es;
 862         unsigned long bitmap_count, x;
 863         struct buffer_head *bitmap_bh = NULL;
 864
 865         es = EXT4_SB(sb)->s_es;
 866         desc_count = 0;
 867         bitmap_count = 0;
 868         gdp = NULL;
 869         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 870                 gdp = ext4_get_group_desc (sb, i, NULL);
 871                 if (!gdp)
 872                         continue;
 873                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 874                 brelse(bitmap_bh);
 875                 bitmap_bh = read_inode_bitmap(sb, i);
 876                 if (!bitmap_bh)
 877                         continue;
 878
 879                 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
 880                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
 881                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
 882                 bitmap_count += x;
 883         }
 884         brelse(bitmap_bh);
 885         printk("ext4_count_free_inodes: stored = %u, computed = %lu, %lu\n",
 886                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
 887         return desc_count;
 888 #else
 889         desc_count = 0;
 890         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 891                 gdp = ext4_get_group_desc (sb, i, NULL);
 892                 if (!gdp)
 893                         continue;
 894                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
 895                 cond_resched();
 896         }
 897         return desc_count;
 898 #endif
 899 }
 900
 901 /* Called at mount-time, super-block is locked */
 902 unsigned long ext4_count_dirs (struct super_block * sb)
 903 {
 904         unsigned long count = 0;
 905         ext4_group_t i;
 906
 907         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
 908                 struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
 909                 if (!gdp)
 910                         continue;
 911                 count += le16_to_cpu(gdp->bg_used_dirs_count);
 912         }
 913         return count;
 914 }
 915