fs/ext4/ialloc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/ialloc.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  BSD ufs-inspired inode and directory allocation by
  11  *  Stephen Tweedie (sct@redhat.com), 1993
  12  *  Big-endian to little-endian byte-swapping/bitmaps by
  13  *        David S. Miller (davem@caip.rutgers.edu), 1995
  14  */
  15
  16 #include <linux/time.h>
  17 #include <linux/fs.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 <linux/cred.h>
  26
  27 #include <asm/byteorder.h>
  28
  29 #include "ext4.h"
  30 #include "ext4_jbd2.h"
  31 #include "xattr.h"
  32 #include "acl.h"
  33
  34 #include <trace/events/ext4.h>
  35
  36 /*
  37  * ialloc.c contains the inodes allocation and deallocation routines
  38  */
  39
  40 /*
  41  * The free inodes are managed by bitmaps.  A file system contains several
  42  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  43  * block for inodes, N blocks for the inode table and data blocks.
  44  *
  45  * The file system contains group descriptors which are located after the
  46  * super block.  Each descriptor contains the number of the bitmap block and
  47  * the free blocks count in the block.
  48  */
  49
  50 /*
  51  * To avoid calling the atomic setbit hundreds or thousands of times, we only
  52  * need to use it within a single byte (to ensure we get endianness right).
  53  * We can use memset for the rest of the bitmap as there are no other users.
  54  */
  55 void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
  56 {
  57         int i;
  58
  59         if (start_bit >= end_bit)
  60                 return;
  61
  62         ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
  63         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
  64                 ext4_set_bit(i, bitmap);
  65         if (i < end_bit)
  66                 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
  67 }
  68
  69 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
  70 {
  71         if (uptodate) {
  72                 set_buffer_uptodate(bh);
  73                 set_bitmap_uptodate(bh);
  74         }
  75         unlock_buffer(bh);
  76         put_bh(bh);
  77 }
  78
  79 static int ext4_validate_inode_bitmap(struct super_block *sb,
  80                                       struct ext4_group_desc *desc,
  81                                       ext4_group_t block_group,
  82                                       struct buffer_head *bh)
  83 {
  84         ext4_fsblk_t    blk;
  85         struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
  86
  87         if (buffer_verified(bh))
  88                 return 0;
  89         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
  90                 return -EFSCORRUPTED;
  91
  92         ext4_lock_group(sb, block_group);
  93         if (buffer_verified(bh))
  94                 goto verified;
  95         blk = ext4_inode_bitmap(sb, desc);
  96         if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
  97                                            EXT4_INODES_PER_GROUP(sb) / 8) ||
  98             ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
  99                 ext4_unlock_group(sb, block_group);
 100                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 101                            "inode_bitmap = %llu", block_group, blk);
 102                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 103                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 104                 return -EFSBADCRC;
 105         }
 106         set_buffer_verified(bh);
 107 verified:
 108         ext4_unlock_group(sb, block_group);
 109         return 0;
 110 }
 111
 112 /*
 113  * Read the inode allocation bitmap for a given block_group, reading
 114  * into the specified slot in the superblock's bitmap cache.
 115  *
 116  * Return buffer_head of bitmap on success, or an ERR_PTR on error.
 117  */
 118 static struct buffer_head *
 119 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 120 {
 121         struct ext4_group_desc *desc;
 122         struct ext4_sb_info *sbi = EXT4_SB(sb);
 123         struct buffer_head *bh = NULL;
 124         ext4_fsblk_t bitmap_blk;
 125         int err;
 126
 127         desc = ext4_get_group_desc(sb, block_group, NULL);
 128         if (!desc)
 129                 return ERR_PTR(-EFSCORRUPTED);
 130
 131         bitmap_blk = ext4_inode_bitmap(sb, desc);
 132         if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
 133             (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
 134                 ext4_error(sb, "Invalid inode bitmap blk %llu in "
 135                            "block_group %u", bitmap_blk, block_group);
 136                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 137                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 138                 return ERR_PTR(-EFSCORRUPTED);
 139         }
 140         bh = sb_getblk(sb, bitmap_blk);
 141         if (unlikely(!bh)) {
 142                 ext4_warning(sb, "Cannot read inode bitmap - "
 143                              "block_group = %u, inode_bitmap = %llu",
 144                              block_group, bitmap_blk);
 145                 return ERR_PTR(-ENOMEM);
 146         }
 147         if (bitmap_uptodate(bh))
 148                 goto verify;
 149
 150         lock_buffer(bh);
 151         if (bitmap_uptodate(bh)) {
 152                 unlock_buffer(bh);
 153                 goto verify;
 154         }
 155
 156         ext4_lock_group(sb, block_group);
 157         if (ext4_has_group_desc_csum(sb) &&
 158             (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
 159                 if (block_group == 0) {
 160                         ext4_unlock_group(sb, block_group);
 161                         unlock_buffer(bh);
 162                         ext4_error(sb, "Inode bitmap for bg 0 marked "
 163                                    "uninitialized");
 164                         err = -EFSCORRUPTED;
 165                         goto out;
 166                 }
 167                 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 168                 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
 169                                      sb->s_blocksize * 8, bh->b_data);
 170                 set_bitmap_uptodate(bh);
 171                 set_buffer_uptodate(bh);
 172                 set_buffer_verified(bh);
 173                 ext4_unlock_group(sb, block_group);
 174                 unlock_buffer(bh);
 175                 return bh;
 176         }
 177         ext4_unlock_group(sb, block_group);
 178
 179         if (buffer_uptodate(bh)) {
 180                 /*
 181                  * if not uninit if bh is uptodate,
 182                  * bitmap is also uptodate
 183                  */
 184                 set_bitmap_uptodate(bh);
 185                 unlock_buffer(bh);
 186                 goto verify;
 187         }
 188         /*
 189          * submit the buffer_head for reading
 190          */
 191         trace_ext4_load_inode_bitmap(sb, block_group);
 192         bh->b_end_io = ext4_end_bitmap_read;
 193         get_bh(bh);
 194         submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 195         wait_on_buffer(bh);
 196         ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
 197         if (!buffer_uptodate(bh)) {
 198                 put_bh(bh);
 199                 ext4_error_err(sb, EIO, "Cannot read inode bitmap - "
 200                                "block_group = %u, inode_bitmap = %llu",
 201                                block_group, bitmap_blk);
 202                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 203                                 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 204                 return ERR_PTR(-EIO);
 205         }
 206
 207 verify:
 208         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 209         if (err)
 210                 goto out;
 211         return bh;
 212 out:
 213         put_bh(bh);
 214         return ERR_PTR(err);
 215 }
 216
 217 /*
 218  * NOTE! When we get the inode, we're the only people
 219  * that have access to it, and as such there are no
 220  * race conditions we have to worry about. The inode
 221  * is not on the hash-lists, and it cannot be reached
 222  * through the filesystem because the directory entry
 223  * has been deleted earlier.
 224  *
 225  * HOWEVER: we must make sure that we get no aliases,
 226  * which means that we have to call "clear_inode()"
 227  * _before_ we mark the inode not in use in the inode
 228  * bitmaps. Otherwise a newly created file might use
 229  * the same inode number (not actually the same pointer
 230  * though), and then we'd have two inodes sharing the
 231  * same inode number and space on the harddisk.
 232  */
 233 void ext4_free_inode(handle_t *handle, struct inode *inode)
 234 {
 235         struct super_block *sb = inode->i_sb;
 236         int is_directory;
 237         unsigned long ino;
 238         struct buffer_head *bitmap_bh = NULL;
 239         struct buffer_head *bh2;
 240         ext4_group_t block_group;
 241         unsigned long bit;
 242         struct ext4_group_desc *gdp;
 243         struct ext4_super_block *es;
 244         struct ext4_sb_info *sbi;
 245         int fatal = 0, err, count, cleared;
 246         struct ext4_group_info *grp;
 247
 248         if (!sb) {
 249                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 250                        "nonexistent device\n", __func__, __LINE__);
 251                 return;
 252         }
 253         if (atomic_read(&inode->i_count) > 1) {
 254                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 255                          __func__, __LINE__, inode->i_ino,
 256                          atomic_read(&inode->i_count));
 257                 return;
 258         }
 259         if (inode->i_nlink) {
 260                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 261                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 262                 return;
 263         }
 264         sbi = EXT4_SB(sb);
 265
 266         ino = inode->i_ino;
 267         ext4_debug("freeing inode %lu\n", ino);
 268         trace_ext4_free_inode(inode);
 269
 270         dquot_initialize(inode);
 271         dquot_free_inode(inode);
 272
 273         is_directory = S_ISDIR(inode->i_mode);
 274
 275         /* Do this BEFORE marking the inode not in use or returning an error */
 276         ext4_clear_inode(inode);
 277
 278         es = sbi->s_es;
 279         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 280                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 281                 goto error_return;
 282         }
 283         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 284         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 285         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 286         /* Don't bother if the inode bitmap is corrupt. */
 287         grp = ext4_get_group_info(sb, block_group);
 288         if (IS_ERR(bitmap_bh)) {
 289                 fatal = PTR_ERR(bitmap_bh);
 290                 bitmap_bh = NULL;
 291                 goto error_return;
 292         }
 293         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 294                 fatal = -EFSCORRUPTED;
 295                 goto error_return;
 296         }
 297
 298         BUFFER_TRACE(bitmap_bh, "get_write_access");
 299         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 300         if (fatal)
 301                 goto error_return;
 302
 303         fatal = -ESRCH;
 304         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 305         if (gdp) {
 306                 BUFFER_TRACE(bh2, "get_write_access");
 307                 fatal = ext4_journal_get_write_access(handle, bh2);
 308         }
 309         ext4_lock_group(sb, block_group);
 310         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 311         if (fatal || !cleared) {
 312                 ext4_unlock_group(sb, block_group);
 313                 goto out;
 314         }
 315
 316         count = ext4_free_inodes_count(sb, gdp) + 1;
 317         ext4_free_inodes_set(sb, gdp, count);
 318         if (is_directory) {
 319                 count = ext4_used_dirs_count(sb, gdp) - 1;
 320                 ext4_used_dirs_set(sb, gdp, count);
 321                 percpu_counter_dec(&sbi->s_dirs_counter);
 322         }
 323         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 324                                    EXT4_INODES_PER_GROUP(sb) / 8);
 325         ext4_group_desc_csum_set(sb, block_group, gdp);
 326         ext4_unlock_group(sb, block_group);
 327
 328         percpu_counter_inc(&sbi->s_freeinodes_counter);
 329         if (sbi->s_log_groups_per_flex) {
 330                 struct flex_groups *fg;
 331
 332                 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
 333                                          ext4_flex_group(sbi, block_group));
 334                 atomic_inc(&fg->free_inodes);
 335                 if (is_directory)
 336                         atomic_dec(&fg->used_dirs);
 337         }
 338         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
 339         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
 340 out:
 341         if (cleared) {
 342                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
 343                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 344                 if (!fatal)
 345                         fatal = err;
 346         } else {
 347                 ext4_error(sb, "bit already cleared for inode %lu", ino);
 348                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 349                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 350         }
 351
 352 error_return:
 353         brelse(bitmap_bh);
 354         ext4_std_error(sb, fatal);
 355 }
 356
 357 struct orlov_stats {
 358         __u64 free_clusters;
 359         __u32 free_inodes;
 360         __u32 used_dirs;
 361 };
 362
 363 /*
 364  * Helper function for Orlov's allocator; returns critical information
 365  * for a particular block group or flex_bg.  If flex_size is 1, then g
 366  * is a block group number; otherwise it is flex_bg number.
 367  */
 368 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 369                             int flex_size, struct orlov_stats *stats)
 370 {
 371         struct ext4_group_desc *desc;
 372
 373         if (flex_size > 1) {
 374                 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
 375                                                              s_flex_groups, g);
 376                 stats->free_inodes = atomic_read(&fg->free_inodes);
 377                 stats->free_clusters = atomic64_read(&fg->free_clusters);
 378                 stats->used_dirs = atomic_read(&fg->used_dirs);
 379                 return;
 380         }
 381
 382         desc = ext4_get_group_desc(sb, g, NULL);
 383         if (desc) {
 384                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 385                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 386                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 387         } else {
 388                 stats->free_inodes = 0;
 389                 stats->free_clusters = 0;
 390                 stats->used_dirs = 0;
 391         }
 392 }
 393
 394 /*
 395  * Orlov's allocator for directories.
 396  *
 397  * We always try to spread first-level directories.
 398  *
 399  * If there are blockgroups with both free inodes and free blocks counts
 400  * not worse than average we return one with smallest directory count.
 401  * Otherwise we simply return a random group.
 402  *
 403  * For the rest rules look so:
 404  *
 405  * It's OK to put directory into a group unless
 406  * it has too many directories already (max_dirs) or
 407  * it has too few free inodes left (min_inodes) or
 408  * it has too few free blocks left (min_blocks) or
 409  * Parent's group is preferred, if it doesn't satisfy these
 410  * conditions we search cyclically through the rest. If none
 411  * of the groups look good we just look for a group with more
 412  * free inodes than average (starting at parent's group).
 413  */
 414
 415 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 416                             ext4_group_t *group, umode_t mode,
 417                             const struct qstr *qstr)
 418 {
 419         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 420         struct ext4_sb_info *sbi = EXT4_SB(sb);
 421         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 422         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 423         unsigned int freei, avefreei, grp_free;
 424         ext4_fsblk_t freeb, avefreec;
 425         unsigned int ndirs;
 426         int max_dirs, min_inodes;
 427         ext4_grpblk_t min_clusters;
 428         ext4_group_t i, grp, g, ngroups;
 429         struct ext4_group_desc *desc;
 430         struct orlov_stats stats;
 431         int flex_size = ext4_flex_bg_size(sbi);
 432         struct dx_hash_info hinfo;
 433
 434         ngroups = real_ngroups;
 435         if (flex_size > 1) {
 436                 ngroups = (real_ngroups + flex_size - 1) >>
 437                         sbi->s_log_groups_per_flex;
 438                 parent_group >>= sbi->s_log_groups_per_flex;
 439         }
 440
 441         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 442         avefreei = freei / ngroups;
 443         freeb = EXT4_C2B(sbi,
 444                 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
 445         avefreec = freeb;
 446         do_div(avefreec, ngroups);
 447         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 448
 449         if (S_ISDIR(mode) &&
 450             ((parent == d_inode(sb->s_root)) ||
 451              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 452                 int best_ndir = inodes_per_group;
 453                 int ret = -1;
 454
 455                 if (qstr) {
 456                         hinfo.hash_version = DX_HASH_HALF_MD4;
 457                         hinfo.seed = sbi->s_hash_seed;
 458                         ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 459                         grp = hinfo.hash;
 460                 } else
 461                         grp = prandom_u32();
 462                 parent_group = (unsigned)grp % ngroups;
 463                 for (i = 0; i < ngroups; i++) {
 464                         g = (parent_group + i) % ngroups;
 465                         get_orlov_stats(sb, g, flex_size, &stats);
 466                         if (!stats.free_inodes)
 467                                 continue;
 468                         if (stats.used_dirs >= best_ndir)
 469                                 continue;
 470                         if (stats.free_inodes < avefreei)
 471                                 continue;
 472                         if (stats.free_clusters < avefreec)
 473                                 continue;
 474                         grp = g;
 475                         ret = 0;
 476                         best_ndir = stats.used_dirs;
 477                 }
 478                 if (ret)
 479                         goto fallback;
 480         found_flex_bg:
 481                 if (flex_size == 1) {
 482                         *group = grp;
 483                         return 0;
 484                 }
 485
 486                 /*
 487                  * We pack inodes at the beginning of the flexgroup's
 488                  * inode tables.  Block allocation decisions will do
 489                  * something similar, although regular files will
 490                  * start at 2nd block group of the flexgroup.  See
 491                  * ext4_ext_find_goal() and ext4_find_near().
 492                  */
 493                 grp *= flex_size;
 494                 for (i = 0; i < flex_size; i++) {
 495                         if (grp+i >= real_ngroups)
 496                                 break;
 497                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 498                         if (desc && ext4_free_inodes_count(sb, desc)) {
 499                                 *group = grp+i;
 500                                 return 0;
 501                         }
 502                 }
 503                 goto fallback;
 504         }
 505
 506         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 507         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 508         if (min_inodes < 1)
 509                 min_inodes = 1;
 510         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 511
 512         /*
 513          * Start looking in the flex group where we last allocated an
 514          * inode for this parent directory
 515          */
 516         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 517                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 518                 if (flex_size > 1)
 519                         parent_group >>= sbi->s_log_groups_per_flex;
 520         }
 521
 522         for (i = 0; i < ngroups; i++) {
 523                 grp = (parent_group + i) % ngroups;
 524                 get_orlov_stats(sb, grp, flex_size, &stats);
 525                 if (stats.used_dirs >= max_dirs)
 526                         continue;
 527                 if (stats.free_inodes < min_inodes)
 528                         continue;
 529                 if (stats.free_clusters < min_clusters)
 530                         continue;
 531                 goto found_flex_bg;
 532         }
 533
 534 fallback:
 535         ngroups = real_ngroups;
 536         avefreei = freei / ngroups;
 537 fallback_retry:
 538         parent_group = EXT4_I(parent)->i_block_group;
 539         for (i = 0; i < ngroups; i++) {
 540                 grp = (parent_group + i) % ngroups;
 541                 desc = ext4_get_group_desc(sb, grp, NULL);
 542                 if (desc) {
 543                         grp_free = ext4_free_inodes_count(sb, desc);
 544                         if (grp_free && grp_free >= avefreei) {
 545                                 *group = grp;
 546                                 return 0;
 547                         }
 548                 }
 549         }
 550
 551         if (avefreei) {
 552                 /*
 553                  * The free-inodes counter is approximate, and for really small
 554                  * filesystems the above test can fail to find any blockgroups
 555                  */
 556                 avefreei = 0;
 557                 goto fallback_retry;
 558         }
 559
 560         return -1;
 561 }
 562
 563 static int find_group_other(struct super_block *sb, struct inode *parent,
 564                             ext4_group_t *group, umode_t mode)
 565 {
 566         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 567         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 568         struct ext4_group_desc *desc;
 569         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 570
 571         /*
 572          * Try to place the inode is the same flex group as its
 573          * parent.  If we can't find space, use the Orlov algorithm to
 574          * find another flex group, and store that information in the
 575          * parent directory's inode information so that use that flex
 576          * group for future allocations.
 577          */
 578         if (flex_size > 1) {
 579                 int retry = 0;
 580
 581         try_again:
 582                 parent_group &= ~(flex_size-1);
 583                 last = parent_group + flex_size;
 584                 if (last > ngroups)
 585                         last = ngroups;
 586                 for  (i = parent_group; i < last; i++) {
 587                         desc = ext4_get_group_desc(sb, i, NULL);
 588                         if (desc && ext4_free_inodes_count(sb, desc)) {
 589                                 *group = i;
 590                                 return 0;
 591                         }
 592                 }
 593                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 594                         retry = 1;
 595                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 596                         goto try_again;
 597                 }
 598                 /*
 599                  * If this didn't work, use the Orlov search algorithm
 600                  * to find a new flex group; we pass in the mode to
 601                  * avoid the topdir algorithms.
 602                  */
 603                 *group = parent_group + flex_size;
 604                 if (*group > ngroups)
 605                         *group = 0;
 606                 return find_group_orlov(sb, parent, group, mode, NULL);
 607         }
 608
 609         /*
 610          * Try to place the inode in its parent directory
 611          */
 612         *group = parent_group;
 613         desc = ext4_get_group_desc(sb, *group, NULL);
 614         if (desc && ext4_free_inodes_count(sb, desc) &&
 615             ext4_free_group_clusters(sb, desc))
 616                 return 0;
 617
 618         /*
 619          * We're going to place this inode in a different blockgroup from its
 620          * parent.  We want to cause files in a common directory to all land in
 621          * the same blockgroup.  But we want files which are in a different
 622          * directory which shares a blockgroup with our parent to land in a
 623          * different blockgroup.
 624          *
 625          * So add our directory's i_ino into the starting point for the hash.
 626          */
 627         *group = (*group + parent->i_ino) % ngroups;
 628
 629         /*
 630          * Use a quadratic hash to find a group with a free inode and some free
 631          * blocks.
 632          */
 633         for (i = 1; i < ngroups; i <<= 1) {
 634                 *group += i;
 635                 if (*group >= ngroups)
 636                         *group -= ngroups;
 637                 desc = ext4_get_group_desc(sb, *group, NULL);
 638                 if (desc && ext4_free_inodes_count(sb, desc) &&
 639                     ext4_free_group_clusters(sb, desc))
 640                         return 0;
 641         }
 642
 643         /*
 644          * That failed: try linear search for a free inode, even if that group
 645          * has no free blocks.
 646          */
 647         *group = parent_group;
 648         for (i = 0; i < ngroups; i++) {
 649                 if (++*group >= ngroups)
 650                         *group = 0;
 651                 desc = ext4_get_group_desc(sb, *group, NULL);
 652                 if (desc && ext4_free_inodes_count(sb, desc))
 653                         return 0;
 654         }
 655
 656         return -1;
 657 }
 658
 659 /*
 660  * In no journal mode, if an inode has recently been deleted, we want
 661  * to avoid reusing it until we're reasonably sure the inode table
 662  * block has been written back to disk.  (Yes, these values are
 663  * somewhat arbitrary...)
 664  */
 665 #define RECENTCY_MIN    60
 666 #define RECENTCY_DIRTY  300
 667
 668 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 669 {
 670         struct ext4_group_desc  *gdp;
 671         struct ext4_inode       *raw_inode;
 672         struct buffer_head      *bh;
 673         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 674         int offset, ret = 0;
 675         int recentcy = RECENTCY_MIN;
 676         u32 dtime, now;
 677
 678         gdp = ext4_get_group_desc(sb, group, NULL);
 679         if (unlikely(!gdp))
 680                 return 0;
 681
 682         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 683                        (ino / inodes_per_block));
 684         if (!bh || !buffer_uptodate(bh))
 685                 /*
 686                  * If the block is not in the buffer cache, then it
 687                  * must have been written out.
 688                  */
 689                 goto out;
 690
 691         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 692         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 693
 694         /* i_dtime is only 32 bits on disk, but we only care about relative
 695          * times in the range of a few minutes (i.e. long enough to sync a
 696          * recently-deleted inode to disk), so using the low 32 bits of the
 697          * clock (a 68 year range) is enough, see time_before32() */
 698         dtime = le32_to_cpu(raw_inode->i_dtime);
 699         now = ktime_get_real_seconds();
 700         if (buffer_dirty(bh))
 701                 recentcy += RECENTCY_DIRTY;
 702
 703         if (dtime && time_before32(dtime, now) &&
 704             time_before32(now, dtime + recentcy))
 705                 ret = 1;
 706 out:
 707         brelse(bh);
 708         return ret;
 709 }
 710
 711 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 712                           struct buffer_head *bitmap, unsigned long *ino)
 713 {
 714         bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
 715         unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
 716
 717 next:
 718         *ino = ext4_find_next_zero_bit((unsigned long *)
 719                                        bitmap->b_data,
 720                                        EXT4_INODES_PER_GROUP(sb), *ino);
 721         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 722                 goto not_found;
 723
 724         if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
 725                 recently_deleted_ino = *ino;
 726                 *ino = *ino + 1;
 727                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 728                         goto next;
 729                 goto not_found;
 730         }
 731         return 1;
 732 not_found:
 733         if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
 734                 return 0;
 735         /*
 736          * Not reusing recently deleted inodes is mostly a preference. We don't
 737          * want to report ENOSPC or skew allocation patterns because of that.
 738          * So return even recently deleted inode if we could find better in the
 739          * given range.
 740          */
 741         *ino = recently_deleted_ino;
 742         return 1;
 743 }
 744
 745 /*
 746  * There are two policies for allocating an inode.  If the new inode is
 747  * a directory, then a forward search is made for a block group with both
 748  * free space and a low directory-to-inode ratio; if that fails, then of
 749  * the groups with above-average free space, that group with the fewest
 750  * directories already is chosen.
 751  *
 752  * For other inodes, search forward from the parent directory's block
 753  * group to find a free inode.
 754  */
 755 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 756                                umode_t mode, const struct qstr *qstr,
 757                                __u32 goal, uid_t *owner, __u32 i_flags,
 758                                int handle_type, unsigned int line_no,
 759                                int nblocks)
 760 {
 761         struct super_block *sb;
 762         struct buffer_head *inode_bitmap_bh = NULL;
 763         struct buffer_head *group_desc_bh;
 764         ext4_group_t ngroups, group = 0;
 765         unsigned long ino = 0;
 766         struct inode *inode;
 767         struct ext4_group_desc *gdp = NULL;
 768         struct ext4_inode_info *ei;
 769         struct ext4_sb_info *sbi;
 770         int ret2, err;
 771         struct inode *ret;
 772         ext4_group_t i;
 773         ext4_group_t flex_group;
 774         struct ext4_group_info *grp;
 775         int encrypt = 0;
 776
 777         /* Cannot create files in a deleted directory */
 778         if (!dir || !dir->i_nlink)
 779                 return ERR_PTR(-EPERM);
 780
 781         sb = dir->i_sb;
 782         sbi = EXT4_SB(sb);
 783
 784         if (unlikely(ext4_forced_shutdown(sbi)))
 785                 return ERR_PTR(-EIO);
 786
 787         if ((IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
 788             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
 789             !(i_flags & EXT4_EA_INODE_FL)) {
 790                 err = fscrypt_get_encryption_info(dir);
 791                 if (err)
 792                         return ERR_PTR(err);
 793                 if (!fscrypt_has_encryption_key(dir))
 794                         return ERR_PTR(-ENOKEY);
 795                 encrypt = 1;
 796         }
 797
 798         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 799 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 800                 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 801
 802                 if (IS_ERR(p))
 803                         return ERR_CAST(p);
 804                 if (p) {
 805                         int acl_size = p->a_count * sizeof(ext4_acl_entry);
 806
 807                         nblocks += (S_ISDIR(mode) ? 2 : 1) *
 808                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 809                                         NULL /* block_bh */, acl_size,
 810                                         true /* is_create */);
 811                         posix_acl_release(p);
 812                 }
 813 #endif
 814
 815 #ifdef CONFIG_SECURITY
 816                 {
 817                         int num_security_xattrs = 1;
 818
 819 #ifdef CONFIG_INTEGRITY
 820                         num_security_xattrs++;
 821 #endif
 822                         /*
 823                          * We assume that security xattrs are never
 824                          * more than 1k.  In practice they are under
 825                          * 128 bytes.
 826                          */
 827                         nblocks += num_security_xattrs *
 828                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 829                                         NULL /* block_bh */, 1024,
 830                                         true /* is_create */);
 831                 }
 832 #endif
 833                 if (encrypt)
 834                         nblocks += __ext4_xattr_set_credits(sb,
 835                                         NULL /* inode */, NULL /* block_bh */,
 836                                         FSCRYPT_SET_CONTEXT_MAX_SIZE,
 837                                         true /* is_create */);
 838         }
 839
 840         ngroups = ext4_get_groups_count(sb);
 841         trace_ext4_request_inode(dir, mode);
 842         inode = new_inode(sb);
 843         if (!inode)
 844                 return ERR_PTR(-ENOMEM);
 845         ei = EXT4_I(inode);
 846
 847         /*
 848          * Initialize owners and quota early so that we don't have to account
 849          * for quota initialization worst case in standard inode creating
 850          * transaction
 851          */
 852         if (owner) {
 853                 inode->i_mode = mode;
 854                 i_uid_write(inode, owner[0]);
 855                 i_gid_write(inode, owner[1]);
 856         } else if (test_opt(sb, GRPID)) {
 857                 inode->i_mode = mode;
 858                 inode->i_uid = current_fsuid();
 859                 inode->i_gid = dir->i_gid;
 860         } else
 861                 inode_init_owner(inode, dir, mode);
 862
 863         if (ext4_has_feature_project(sb) &&
 864             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 865                 ei->i_projid = EXT4_I(dir)->i_projid;
 866         else
 867                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 868
 869         err = dquot_initialize(inode);
 870         if (err)
 871                 goto out;
 872
 873         if (!goal)
 874                 goal = sbi->s_inode_goal;
 875
 876         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
 877                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
 878                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
 879                 ret2 = 0;
 880                 goto got_group;
 881         }
 882
 883         if (S_ISDIR(mode))
 884                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
 885         else
 886                 ret2 = find_group_other(sb, dir, &group, mode);
 887
 888 got_group:
 889         EXT4_I(dir)->i_last_alloc_group = group;
 890         err = -ENOSPC;
 891         if (ret2 == -1)
 892                 goto out;
 893
 894         /*
 895          * Normally we will only go through one pass of this loop,
 896          * unless we get unlucky and it turns out the group we selected
 897          * had its last inode grabbed by someone else.
 898          */
 899         for (i = 0; i < ngroups; i++, ino = 0) {
 900                 err = -EIO;
 901
 902                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 903                 if (!gdp)
 904                         goto out;
 905
 906                 /*
 907                  * Check free inodes count before loading bitmap.
 908                  */
 909                 if (ext4_free_inodes_count(sb, gdp) == 0)
 910                         goto next_group;
 911
 912                 grp = ext4_get_group_info(sb, group);
 913                 /* Skip groups with already-known suspicious inode tables */
 914                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 915                         goto next_group;
 916
 917                 brelse(inode_bitmap_bh);
 918                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 919                 /* Skip groups with suspicious inode tables */
 920                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 921                     IS_ERR(inode_bitmap_bh)) {
 922                         inode_bitmap_bh = NULL;
 923                         goto next_group;
 924                 }
 925
 926 repeat_in_this_group:
 927                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 928                 if (!ret2)
 929                         goto next_group;
 930
 931                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 932                         ext4_error(sb, "reserved inode found cleared - "
 933                                    "inode=%lu", ino + 1);
 934                         ext4_mark_group_bitmap_corrupted(sb, group,
 935                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 936                         goto next_group;
 937                 }
 938
 939                 if (!handle) {
 940                         BUG_ON(nblocks <= 0);
 941                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
 942                                  handle_type, nblocks, 0,
 943                                  ext4_trans_default_revoke_credits(sb));
 944                         if (IS_ERR(handle)) {
 945                                 err = PTR_ERR(handle);
 946                                 ext4_std_error(sb, err);
 947                                 goto out;
 948                         }
 949                 }
 950                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
 951                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
 952                 if (err) {
 953                         ext4_std_error(sb, err);
 954                         goto out;
 955                 }
 956                 ext4_lock_group(sb, group);
 957                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
 958                 if (ret2) {
 959                         /* Someone already took the bit. Repeat the search
 960                          * with lock held.
 961                          */
 962                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 963                         if (ret2) {
 964                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
 965                                 ret2 = 0;
 966                         } else {
 967                                 ret2 = 1; /* we didn't grab the inode */
 968                         }
 969                 }
 970                 ext4_unlock_group(sb, group);
 971                 ino++;          /* the inode bitmap is zero-based */
 972                 if (!ret2)
 973                         goto got; /* we grabbed the inode! */
 974
 975                 if (ino < EXT4_INODES_PER_GROUP(sb))
 976                         goto repeat_in_this_group;
 977 next_group:
 978                 if (++group == ngroups)
 979                         group = 0;
 980         }
 981         err = -ENOSPC;
 982         goto out;
 983
 984 got:
 985         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 986         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
 987         if (err) {
 988                 ext4_std_error(sb, err);
 989                 goto out;
 990         }
 991
 992         BUFFER_TRACE(group_desc_bh, "get_write_access");
 993         err = ext4_journal_get_write_access(handle, group_desc_bh);
 994         if (err) {
 995                 ext4_std_error(sb, err);
 996                 goto out;
 997         }
 998
 999         /* We may have to initialize the block bitmap if it isn't already */
1000         if (ext4_has_group_desc_csum(sb) &&
1001             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1002                 struct buffer_head *block_bitmap_bh;
1003
1004                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1005                 if (IS_ERR(block_bitmap_bh)) {
1006                         err = PTR_ERR(block_bitmap_bh);
1007                         goto out;
1008                 }
1009                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1010                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1011                 if (err) {
1012                         brelse(block_bitmap_bh);
1013                         ext4_std_error(sb, err);
1014                         goto out;
1015                 }
1016
1017                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1018                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1019
1020                 /* recheck and clear flag under lock if we still need to */
1021                 ext4_lock_group(sb, group);
1022                 if (ext4_has_group_desc_csum(sb) &&
1023                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1024                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1025                         ext4_free_group_clusters_set(sb, gdp,
1026                                 ext4_free_clusters_after_init(sb, group, gdp));
1027                         ext4_block_bitmap_csum_set(sb, group, gdp,
1028                                                    block_bitmap_bh);
1029                         ext4_group_desc_csum_set(sb, group, gdp);
1030                 }
1031                 ext4_unlock_group(sb, group);
1032                 brelse(block_bitmap_bh);
1033
1034                 if (err) {
1035                         ext4_std_error(sb, err);
1036                         goto out;
1037                 }
1038         }
1039
1040         /* Update the relevant bg descriptor fields */
1041         if (ext4_has_group_desc_csum(sb)) {
1042                 int free;
1043                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1044
1045                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1046                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1047                 free = EXT4_INODES_PER_GROUP(sb) -
1048                         ext4_itable_unused_count(sb, gdp);
1049                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1050                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1051                         free = 0;
1052                 }
1053                 /*
1054                  * Check the relative inode number against the last used
1055                  * relative inode number in this group. if it is greater
1056                  * we need to update the bg_itable_unused count
1057                  */
1058                 if (ino > free)
1059                         ext4_itable_unused_set(sb, gdp,
1060                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1061                 up_read(&grp->alloc_sem);
1062         } else {
1063                 ext4_lock_group(sb, group);
1064         }
1065
1066         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1067         if (S_ISDIR(mode)) {
1068                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1069                 if (sbi->s_log_groups_per_flex) {
1070                         ext4_group_t f = ext4_flex_group(sbi, group);
1071
1072                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1073                                                         f)->used_dirs);
1074                 }
1075         }
1076         if (ext4_has_group_desc_csum(sb)) {
1077                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1078                                            EXT4_INODES_PER_GROUP(sb) / 8);
1079                 ext4_group_desc_csum_set(sb, group, gdp);
1080         }
1081         ext4_unlock_group(sb, group);
1082
1083         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1084         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1085         if (err) {
1086                 ext4_std_error(sb, err);
1087                 goto out;
1088         }
1089
1090         percpu_counter_dec(&sbi->s_freeinodes_counter);
1091         if (S_ISDIR(mode))
1092                 percpu_counter_inc(&sbi->s_dirs_counter);
1093
1094         if (sbi->s_log_groups_per_flex) {
1095                 flex_group = ext4_flex_group(sbi, group);
1096                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1097                                                 flex_group)->free_inodes);
1098         }
1099
1100         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1101         /* This is the optimal IO size (for stat), not the fs block size */
1102         inode->i_blocks = 0;
1103         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1104         ei->i_crtime = inode->i_mtime;
1105
1106         memset(ei->i_data, 0, sizeof(ei->i_data));
1107         ei->i_dir_start_lookup = 0;
1108         ei->i_disksize = 0;
1109
1110         /* Don't inherit extent flag from directory, amongst others. */
1111         ei->i_flags =
1112                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1113         ei->i_flags |= i_flags;
1114         ei->i_file_acl = 0;
1115         ei->i_dtime = 0;
1116         ei->i_block_group = group;
1117         ei->i_last_alloc_group = ~0;
1118
1119         ext4_set_inode_flags(inode, true);
1120         if (IS_DIRSYNC(inode))
1121                 ext4_handle_sync(handle);
1122         if (insert_inode_locked(inode) < 0) {
1123                 /*
1124                  * Likely a bitmap corruption causing inode to be allocated
1125                  * twice.
1126                  */
1127                 err = -EIO;
1128                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1129                            inode->i_ino);
1130                 ext4_mark_group_bitmap_corrupted(sb, group,
1131                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1132                 goto out;
1133         }
1134         inode->i_generation = prandom_u32();
1135
1136         /* Precompute checksum seed for inode metadata */
1137         if (ext4_has_metadata_csum(sb)) {
1138                 __u32 csum;
1139                 __le32 inum = cpu_to_le32(inode->i_ino);
1140                 __le32 gen = cpu_to_le32(inode->i_generation);
1141                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1142                                    sizeof(inum));
1143                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1144                                               sizeof(gen));
1145         }
1146
1147         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1148         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1149
1150         ei->i_extra_isize = sbi->s_want_extra_isize;
1151         ei->i_inline_off = 0;
1152         if (ext4_has_feature_inline_data(sb))
1153                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1154         ret = inode;
1155         err = dquot_alloc_inode(inode);
1156         if (err)
1157                 goto fail_drop;
1158
1159         /*
1160          * Since the encryption xattr will always be unique, create it first so
1161          * that it's less likely to end up in an external xattr block and
1162          * prevent its deduplication.
1163          */
1164         if (encrypt) {
1165                 err = fscrypt_inherit_context(dir, inode, handle, true);
1166                 if (err)
1167                         goto fail_free_drop;
1168         }
1169
1170         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1171                 err = ext4_init_acl(handle, inode, dir);
1172                 if (err)
1173                         goto fail_free_drop;
1174
1175                 err = ext4_init_security(handle, inode, dir, qstr);
1176                 if (err)
1177                         goto fail_free_drop;
1178         }
1179
1180         if (ext4_has_feature_extents(sb)) {
1181                 /* set extent flag only for directory, file and normal symlink*/
1182                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1183                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1184                         ext4_ext_tree_init(handle, inode);
1185                 }
1186         }
1187
1188         if (ext4_handle_valid(handle)) {
1189                 ei->i_sync_tid = handle->h_transaction->t_tid;
1190                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1191         }
1192
1193         err = ext4_mark_inode_dirty(handle, inode);
1194         if (err) {
1195                 ext4_std_error(sb, err);
1196                 goto fail_free_drop;
1197         }
1198
1199         ext4_debug("allocating inode %lu\n", inode->i_ino);
1200         trace_ext4_allocate_inode(inode, dir, mode);
1201         brelse(inode_bitmap_bh);
1202         return ret;
1203
1204 fail_free_drop:
1205         dquot_free_inode(inode);
1206 fail_drop:
1207         clear_nlink(inode);
1208         unlock_new_inode(inode);
1209 out:
1210         dquot_drop(inode);
1211         inode->i_flags |= S_NOQUOTA;
1212         iput(inode);
1213         brelse(inode_bitmap_bh);
1214         return ERR_PTR(err);
1215 }
1216
1217 /* Verify that we are loading a valid orphan from disk */
1218 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1219 {
1220         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1221         ext4_group_t block_group;
1222         int bit;
1223         struct buffer_head *bitmap_bh = NULL;
1224         struct inode *inode = NULL;
1225         int err = -EFSCORRUPTED;
1226
1227         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1228                 goto bad_orphan;
1229
1230         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1231         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1232         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1233         if (IS_ERR(bitmap_bh))
1234                 return ERR_CAST(bitmap_bh);
1235
1236         /* Having the inode bit set should be a 100% indicator that this
1237          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1238          * inodes that were being truncated, so we can't check i_nlink==0.
1239          */
1240         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1241                 goto bad_orphan;
1242
1243         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1244         if (IS_ERR(inode)) {
1245                 err = PTR_ERR(inode);
1246                 ext4_error_err(sb, -err,
1247                                "couldn't read orphan inode %lu (err %d)",
1248                                ino, err);
1249                 brelse(bitmap_bh);
1250                 return inode;
1251         }
1252
1253         /*
1254          * If the orphans has i_nlinks > 0 then it should be able to
1255          * be truncated, otherwise it won't be removed from the orphan
1256          * list during processing and an infinite loop will result.
1257          * Similarly, it must not be a bad inode.
1258          */
1259         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1260             is_bad_inode(inode))
1261                 goto bad_orphan;
1262
1263         if (NEXT_ORPHAN(inode) > max_ino)
1264                 goto bad_orphan;
1265         brelse(bitmap_bh);
1266         return inode;
1267
1268 bad_orphan:
1269         ext4_error(sb, "bad orphan inode %lu", ino);
1270         if (bitmap_bh)
1271                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1272                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1273                        ext4_test_bit(bit, bitmap_bh->b_data));
1274         if (inode) {
1275                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1276                        is_bad_inode(inode));
1277                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1278                        NEXT_ORPHAN(inode));
1279                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1280                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1281                 /* Avoid freeing blocks if we got a bad deleted inode */
1282                 if (inode->i_nlink == 0)
1283                         inode->i_blocks = 0;
1284                 iput(inode);
1285         }
1286         brelse(bitmap_bh);
1287         return ERR_PTR(err);
1288 }
1289
1290 unsigned long ext4_count_free_inodes(struct super_block *sb)
1291 {
1292         unsigned long desc_count;
1293         struct ext4_group_desc *gdp;
1294         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1295 #ifdef EXT4FS_DEBUG
1296         struct ext4_super_block *es;
1297         unsigned long bitmap_count, x;
1298         struct buffer_head *bitmap_bh = NULL;
1299
1300         es = EXT4_SB(sb)->s_es;
1301         desc_count = 0;
1302         bitmap_count = 0;
1303         gdp = NULL;
1304         for (i = 0; i < ngroups; i++) {
1305                 gdp = ext4_get_group_desc(sb, i, NULL);
1306                 if (!gdp)
1307                         continue;
1308                 desc_count += ext4_free_inodes_count(sb, gdp);
1309                 brelse(bitmap_bh);
1310                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1311                 if (IS_ERR(bitmap_bh)) {
1312                         bitmap_bh = NULL;
1313                         continue;
1314                 }
1315
1316                 x = ext4_count_free(bitmap_bh->b_data,
1317                                     EXT4_INODES_PER_GROUP(sb) / 8);
1318                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1319                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1320                 bitmap_count += x;
1321         }
1322         brelse(bitmap_bh);
1323         printk(KERN_DEBUG "ext4_count_free_inodes: "
1324                "stored = %u, computed = %lu, %lu\n",
1325                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1326         return desc_count;
1327 #else
1328         desc_count = 0;
1329         for (i = 0; i < ngroups; i++) {
1330                 gdp = ext4_get_group_desc(sb, i, NULL);
1331                 if (!gdp)
1332                         continue;
1333                 desc_count += ext4_free_inodes_count(sb, gdp);
1334                 cond_resched();
1335         }
1336         return desc_count;
1337 #endif
1338 }
1339
1340 /* Called at mount-time, super-block is locked */
1341 unsigned long ext4_count_dirs(struct super_block * sb)
1342 {
1343         unsigned long count = 0;
1344         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1345
1346         for (i = 0; i < ngroups; i++) {
1347                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1348                 if (!gdp)
1349                         continue;
1350                 count += ext4_used_dirs_count(sb, gdp);
1351         }
1352         return count;
1353 }
1354
1355 /*
1356  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1357  * inode table. Must be called without any spinlock held. The only place
1358  * where it is called from on active part of filesystem is ext4lazyinit
1359  * thread, so we do not need any special locks, however we have to prevent
1360  * inode allocation from the current group, so we take alloc_sem lock, to
1361  * block ext4_new_inode() until we are finished.
1362  */
1363 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1364                                  int barrier)
1365 {
1366         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1367         struct ext4_sb_info *sbi = EXT4_SB(sb);
1368         struct ext4_group_desc *gdp = NULL;
1369         struct buffer_head *group_desc_bh;
1370         handle_t *handle;
1371         ext4_fsblk_t blk;
1372         int num, ret = 0, used_blks = 0;
1373
1374         /* This should not happen, but just to be sure check this */
1375         if (sb_rdonly(sb)) {
1376                 ret = 1;
1377                 goto out;
1378         }
1379
1380         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1381         if (!gdp)
1382                 goto out;
1383
1384         /*
1385          * We do not need to lock this, because we are the only one
1386          * handling this flag.
1387          */
1388         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1389                 goto out;
1390
1391         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1392         if (IS_ERR(handle)) {
1393                 ret = PTR_ERR(handle);
1394                 goto out;
1395         }
1396
1397         down_write(&grp->alloc_sem);
1398         /*
1399          * If inode bitmap was already initialized there may be some
1400          * used inodes so we need to skip blocks with used inodes in
1401          * inode table.
1402          */
1403         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1404                 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1405                             ext4_itable_unused_count(sb, gdp)),
1406                             sbi->s_inodes_per_block);
1407
1408         if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) ||
1409             ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) -
1410                                ext4_itable_unused_count(sb, gdp)) <
1411                               EXT4_FIRST_INO(sb)))) {
1412                 ext4_error(sb, "Something is wrong with group %u: "
1413                            "used itable blocks: %d; "
1414                            "itable unused count: %u",
1415                            group, used_blks,
1416                            ext4_itable_unused_count(sb, gdp));
1417                 ret = 1;
1418                 goto err_out;
1419         }
1420
1421         blk = ext4_inode_table(sb, gdp) + used_blks;
1422         num = sbi->s_itb_per_group - used_blks;
1423
1424         BUFFER_TRACE(group_desc_bh, "get_write_access");
1425         ret = ext4_journal_get_write_access(handle,
1426                                             group_desc_bh);
1427         if (ret)
1428                 goto err_out;
1429
1430         /*
1431          * Skip zeroout if the inode table is full. But we set the ZEROED
1432          * flag anyway, because obviously, when it is full it does not need
1433          * further zeroing.
1434          */
1435         if (unlikely(num == 0))
1436                 goto skip_zeroout;
1437
1438         ext4_debug("going to zero out inode table in group %d\n",
1439                    group);
1440         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1441         if (ret < 0)
1442                 goto err_out;
1443         if (barrier)
1444                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS);
1445
1446 skip_zeroout:
1447         ext4_lock_group(sb, group);
1448         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1449         ext4_group_desc_csum_set(sb, group, gdp);
1450         ext4_unlock_group(sb, group);
1451
1452         BUFFER_TRACE(group_desc_bh,
1453                      "call ext4_handle_dirty_metadata");
1454         ret = ext4_handle_dirty_metadata(handle, NULL,
1455                                          group_desc_bh);
1456
1457 err_out:
1458         up_write(&grp->alloc_sem);
1459         ext4_journal_stop(handle);
1460 out:
1461         return ret;
1462 }