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 NULL.
 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_set_errno(sb, EIO);
 200                 ext4_error(sb, "Cannot read inode bitmap - "
 201                            "block_group = %u, inode_bitmap = %llu",
 202                            block_group, bitmap_blk);
 203                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 204                                 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 205                 return ERR_PTR(-EIO);
 206         }
 207
 208 verify:
 209         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 210         if (err)
 211                 goto out;
 212         return bh;
 213 out:
 214         put_bh(bh);
 215         return ERR_PTR(err);
 216 }
 217
 218 /*
 219  * NOTE! When we get the inode, we're the only people
 220  * that have access to it, and as such there are no
 221  * race conditions we have to worry about. The inode
 222  * is not on the hash-lists, and it cannot be reached
 223  * through the filesystem because the directory entry
 224  * has been deleted earlier.
 225  *
 226  * HOWEVER: we must make sure that we get no aliases,
 227  * which means that we have to call "clear_inode()"
 228  * _before_ we mark the inode not in use in the inode
 229  * bitmaps. Otherwise a newly created file might use
 230  * the same inode number (not actually the same pointer
 231  * though), and then we'd have two inodes sharing the
 232  * same inode number and space on the harddisk.
 233  */
 234 void ext4_free_inode(handle_t *handle, struct inode *inode)
 235 {
 236         struct super_block *sb = inode->i_sb;
 237         int is_directory;
 238         unsigned long ino;
 239         struct buffer_head *bitmap_bh = NULL;
 240         struct buffer_head *bh2;
 241         ext4_group_t block_group;
 242         unsigned long bit;
 243         struct ext4_group_desc *gdp;
 244         struct ext4_super_block *es;
 245         struct ext4_sb_info *sbi;
 246         int fatal = 0, err, count, cleared;
 247         struct ext4_group_info *grp;
 248
 249         if (!sb) {
 250                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 251                        "nonexistent device\n", __func__, __LINE__);
 252                 return;
 253         }
 254         if (atomic_read(&inode->i_count) > 1) {
 255                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 256                          __func__, __LINE__, inode->i_ino,
 257                          atomic_read(&inode->i_count));
 258                 return;
 259         }
 260         if (inode->i_nlink) {
 261                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 262                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 263                 return;
 264         }
 265         sbi = EXT4_SB(sb);
 266
 267         ino = inode->i_ino;
 268         ext4_debug("freeing inode %lu\n", ino);
 269         trace_ext4_free_inode(inode);
 270
 271         dquot_initialize(inode);
 272         dquot_free_inode(inode);
 273
 274         is_directory = S_ISDIR(inode->i_mode);
 275
 276         /* Do this BEFORE marking the inode not in use or returning an error */
 277         ext4_clear_inode(inode);
 278
 279         es = sbi->s_es;
 280         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 281                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 282                 goto error_return;
 283         }
 284         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 285         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 286         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 287         /* Don't bother if the inode bitmap is corrupt. */
 288         grp = ext4_get_group_info(sb, block_group);
 289         if (IS_ERR(bitmap_bh)) {
 290                 fatal = PTR_ERR(bitmap_bh);
 291                 bitmap_bh = NULL;
 292                 goto error_return;
 293         }
 294         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 295                 fatal = -EFSCORRUPTED;
 296                 goto error_return;
 297         }
 298
 299         BUFFER_TRACE(bitmap_bh, "get_write_access");
 300         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 301         if (fatal)
 302                 goto error_return;
 303
 304         fatal = -ESRCH;
 305         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 306         if (gdp) {
 307                 BUFFER_TRACE(bh2, "get_write_access");
 308                 fatal = ext4_journal_get_write_access(handle, bh2);
 309         }
 310         ext4_lock_group(sb, block_group);
 311         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 312         if (fatal || !cleared) {
 313                 ext4_unlock_group(sb, block_group);
 314                 goto out;
 315         }
 316
 317         count = ext4_free_inodes_count(sb, gdp) + 1;
 318         ext4_free_inodes_set(sb, gdp, count);
 319         if (is_directory) {
 320                 count = ext4_used_dirs_count(sb, gdp) - 1;
 321                 ext4_used_dirs_set(sb, gdp, count);
 322                 percpu_counter_dec(&sbi->s_dirs_counter);
 323         }
 324         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 325                                    EXT4_INODES_PER_GROUP(sb) / 8);
 326         ext4_group_desc_csum_set(sb, block_group, gdp);
 327         ext4_unlock_group(sb, block_group);
 328
 329         percpu_counter_inc(&sbi->s_freeinodes_counter);
 330         if (sbi->s_log_groups_per_flex) {
 331                 struct flex_groups *fg;
 332
 333                 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
 334                                          ext4_flex_group(sbi, block_group));
 335                 atomic_inc(&fg->free_inodes);
 336                 if (is_directory)
 337                         atomic_dec(&fg->used_dirs);
 338         }
 339         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
 340         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
 341 out:
 342         if (cleared) {
 343                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
 344                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 345                 if (!fatal)
 346                         fatal = err;
 347         } else {
 348                 ext4_error(sb, "bit already cleared for inode %lu", ino);
 349                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 350                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 351         }
 352
 353 error_return:
 354         brelse(bitmap_bh);
 355         ext4_std_error(sb, fatal);
 356 }
 357
 358 struct orlov_stats {
 359         __u64 free_clusters;
 360         __u32 free_inodes;
 361         __u32 used_dirs;
 362 };
 363
 364 /*
 365  * Helper function for Orlov's allocator; returns critical information
 366  * for a particular block group or flex_bg.  If flex_size is 1, then g
 367  * is a block group number; otherwise it is flex_bg number.
 368  */
 369 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 370                             int flex_size, struct orlov_stats *stats)
 371 {
 372         struct ext4_group_desc *desc;
 373
 374         if (flex_size > 1) {
 375                 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
 376                                                              s_flex_groups, g);
 377                 stats->free_inodes = atomic_read(&fg->free_inodes);
 378                 stats->free_clusters = atomic64_read(&fg->free_clusters);
 379                 stats->used_dirs = atomic_read(&fg->used_dirs);
 380                 return;
 381         }
 382
 383         desc = ext4_get_group_desc(sb, g, NULL);
 384         if (desc) {
 385                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 386                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 387                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 388         } else {
 389                 stats->free_inodes = 0;
 390                 stats->free_clusters = 0;
 391                 stats->used_dirs = 0;
 392         }
 393 }
 394
 395 /*
 396  * Orlov's allocator for directories.
 397  *
 398  * We always try to spread first-level directories.
 399  *
 400  * If there are blockgroups with both free inodes and free blocks counts
 401  * not worse than average we return one with smallest directory count.
 402  * Otherwise we simply return a random group.
 403  *
 404  * For the rest rules look so:
 405  *
 406  * It's OK to put directory into a group unless
 407  * it has too many directories already (max_dirs) or
 408  * it has too few free inodes left (min_inodes) or
 409  * it has too few free blocks left (min_blocks) or
 410  * Parent's group is preferred, if it doesn't satisfy these
 411  * conditions we search cyclically through the rest. If none
 412  * of the groups look good we just look for a group with more
 413  * free inodes than average (starting at parent's group).
 414  */
 415
 416 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 417                             ext4_group_t *group, umode_t mode,
 418                             const struct qstr *qstr)
 419 {
 420         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 421         struct ext4_sb_info *sbi = EXT4_SB(sb);
 422         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 423         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 424         unsigned int freei, avefreei, grp_free;
 425         ext4_fsblk_t freeb, avefreec;
 426         unsigned int ndirs;
 427         int max_dirs, min_inodes;
 428         ext4_grpblk_t min_clusters;
 429         ext4_group_t i, grp, g, ngroups;
 430         struct ext4_group_desc *desc;
 431         struct orlov_stats stats;
 432         int flex_size = ext4_flex_bg_size(sbi);
 433         struct dx_hash_info hinfo;
 434
 435         ngroups = real_ngroups;
 436         if (flex_size > 1) {
 437                 ngroups = (real_ngroups + flex_size - 1) >>
 438                         sbi->s_log_groups_per_flex;
 439                 parent_group >>= sbi->s_log_groups_per_flex;
 440         }
 441
 442         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 443         avefreei = freei / ngroups;
 444         freeb = EXT4_C2B(sbi,
 445                 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
 446         avefreec = freeb;
 447         do_div(avefreec, ngroups);
 448         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 449
 450         if (S_ISDIR(mode) &&
 451             ((parent == d_inode(sb->s_root)) ||
 452              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 453                 int best_ndir = inodes_per_group;
 454                 int ret = -1;
 455
 456                 if (qstr) {
 457                         hinfo.hash_version = DX_HASH_HALF_MD4;
 458                         hinfo.seed = sbi->s_hash_seed;
 459                         ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 460                         grp = hinfo.hash;
 461                 } else
 462                         grp = prandom_u32();
 463                 parent_group = (unsigned)grp % ngroups;
 464                 for (i = 0; i < ngroups; i++) {
 465                         g = (parent_group + i) % ngroups;
 466                         get_orlov_stats(sb, g, flex_size, &stats);
 467                         if (!stats.free_inodes)
 468                                 continue;
 469                         if (stats.used_dirs >= best_ndir)
 470                                 continue;
 471                         if (stats.free_inodes < avefreei)
 472                                 continue;
 473                         if (stats.free_clusters < avefreec)
 474                                 continue;
 475                         grp = g;
 476                         ret = 0;
 477                         best_ndir = stats.used_dirs;
 478                 }
 479                 if (ret)
 480                         goto fallback;
 481         found_flex_bg:
 482                 if (flex_size == 1) {
 483                         *group = grp;
 484                         return 0;
 485                 }
 486
 487                 /*
 488                  * We pack inodes at the beginning of the flexgroup's
 489                  * inode tables.  Block allocation decisions will do
 490                  * something similar, although regular files will
 491                  * start at 2nd block group of the flexgroup.  See
 492                  * ext4_ext_find_goal() and ext4_find_near().
 493                  */
 494                 grp *= flex_size;
 495                 for (i = 0; i < flex_size; i++) {
 496                         if (grp+i >= real_ngroups)
 497                                 break;
 498                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 499                         if (desc && ext4_free_inodes_count(sb, desc)) {
 500                                 *group = grp+i;
 501                                 return 0;
 502                         }
 503                 }
 504                 goto fallback;
 505         }
 506
 507         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 508         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 509         if (min_inodes < 1)
 510                 min_inodes = 1;
 511         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 512
 513         /*
 514          * Start looking in the flex group where we last allocated an
 515          * inode for this parent directory
 516          */
 517         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 518                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 519                 if (flex_size > 1)
 520                         parent_group >>= sbi->s_log_groups_per_flex;
 521         }
 522
 523         for (i = 0; i < ngroups; i++) {
 524                 grp = (parent_group + i) % ngroups;
 525                 get_orlov_stats(sb, grp, flex_size, &stats);
 526                 if (stats.used_dirs >= max_dirs)
 527                         continue;
 528                 if (stats.free_inodes < min_inodes)
 529                         continue;
 530                 if (stats.free_clusters < min_clusters)
 531                         continue;
 532                 goto found_flex_bg;
 533         }
 534
 535 fallback:
 536         ngroups = real_ngroups;
 537         avefreei = freei / ngroups;
 538 fallback_retry:
 539         parent_group = EXT4_I(parent)->i_block_group;
 540         for (i = 0; i < ngroups; i++) {
 541                 grp = (parent_group + i) % ngroups;
 542                 desc = ext4_get_group_desc(sb, grp, NULL);
 543                 if (desc) {
 544                         grp_free = ext4_free_inodes_count(sb, desc);
 545                         if (grp_free && grp_free >= avefreei) {
 546                                 *group = grp;
 547                                 return 0;
 548                         }
 549                 }
 550         }
 551
 552         if (avefreei) {
 553                 /*
 554                  * The free-inodes counter is approximate, and for really small
 555                  * filesystems the above test can fail to find any blockgroups
 556                  */
 557                 avefreei = 0;
 558                 goto fallback_retry;
 559         }
 560
 561         return -1;
 562 }
 563
 564 static int find_group_other(struct super_block *sb, struct inode *parent,
 565                             ext4_group_t *group, umode_t mode)
 566 {
 567         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 568         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 569         struct ext4_group_desc *desc;
 570         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 571
 572         /*
 573          * Try to place the inode is the same flex group as its
 574          * parent.  If we can't find space, use the Orlov algorithm to
 575          * find another flex group, and store that information in the
 576          * parent directory's inode information so that use that flex
 577          * group for future allocations.
 578          */
 579         if (flex_size > 1) {
 580                 int retry = 0;
 581
 582         try_again:
 583                 parent_group &= ~(flex_size-1);
 584                 last = parent_group + flex_size;
 585                 if (last > ngroups)
 586                         last = ngroups;
 587                 for  (i = parent_group; i < last; i++) {
 588                         desc = ext4_get_group_desc(sb, i, NULL);
 589                         if (desc && ext4_free_inodes_count(sb, desc)) {
 590                                 *group = i;
 591                                 return 0;
 592                         }
 593                 }
 594                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 595                         retry = 1;
 596                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 597                         goto try_again;
 598                 }
 599                 /*
 600                  * If this didn't work, use the Orlov search algorithm
 601                  * to find a new flex group; we pass in the mode to
 602                  * avoid the topdir algorithms.
 603                  */
 604                 *group = parent_group + flex_size;
 605                 if (*group > ngroups)
 606                         *group = 0;
 607                 return find_group_orlov(sb, parent, group, mode, NULL);
 608         }
 609
 610         /*
 611          * Try to place the inode in its parent directory
 612          */
 613         *group = parent_group;
 614         desc = ext4_get_group_desc(sb, *group, NULL);
 615         if (desc && ext4_free_inodes_count(sb, desc) &&
 616             ext4_free_group_clusters(sb, desc))
 617                 return 0;
 618
 619         /*
 620          * We're going to place this inode in a different blockgroup from its
 621          * parent.  We want to cause files in a common directory to all land in
 622          * the same blockgroup.  But we want files which are in a different
 623          * directory which shares a blockgroup with our parent to land in a
 624          * different blockgroup.
 625          *
 626          * So add our directory's i_ino into the starting point for the hash.
 627          */
 628         *group = (*group + parent->i_ino) % ngroups;
 629
 630         /*
 631          * Use a quadratic hash to find a group with a free inode and some free
 632          * blocks.
 633          */
 634         for (i = 1; i < ngroups; i <<= 1) {
 635                 *group += i;
 636                 if (*group >= ngroups)
 637                         *group -= ngroups;
 638                 desc = ext4_get_group_desc(sb, *group, NULL);
 639                 if (desc && ext4_free_inodes_count(sb, desc) &&
 640                     ext4_free_group_clusters(sb, desc))
 641                         return 0;
 642         }
 643
 644         /*
 645          * That failed: try linear search for a free inode, even if that group
 646          * has no free blocks.
 647          */
 648         *group = parent_group;
 649         for (i = 0; i < ngroups; i++) {
 650                 if (++*group >= ngroups)
 651                         *group = 0;
 652                 desc = ext4_get_group_desc(sb, *group, NULL);
 653                 if (desc && ext4_free_inodes_count(sb, desc))
 654                         return 0;
 655         }
 656
 657         return -1;
 658 }
 659
 660 /*
 661  * In no journal mode, if an inode has recently been deleted, we want
 662  * to avoid reusing it until we're reasonably sure the inode table
 663  * block has been written back to disk.  (Yes, these values are
 664  * somewhat arbitrary...)
 665  */
 666 #define RECENTCY_MIN    5
 667 #define RECENTCY_DIRTY  300
 668
 669 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 670 {
 671         struct ext4_group_desc  *gdp;
 672         struct ext4_inode       *raw_inode;
 673         struct buffer_head      *bh;
 674         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 675         int offset, ret = 0;
 676         int recentcy = RECENTCY_MIN;
 677         u32 dtime, now;
 678
 679         gdp = ext4_get_group_desc(sb, group, NULL);
 680         if (unlikely(!gdp))
 681                 return 0;
 682
 683         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 684                        (ino / inodes_per_block));
 685         if (!bh || !buffer_uptodate(bh))
 686                 /*
 687                  * If the block is not in the buffer cache, then it
 688                  * must have been written out.
 689                  */
 690                 goto out;
 691
 692         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 693         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 694
 695         /* i_dtime is only 32 bits on disk, but we only care about relative
 696          * times in the range of a few minutes (i.e. long enough to sync a
 697          * recently-deleted inode to disk), so using the low 32 bits of the
 698          * clock (a 68 year range) is enough, see time_before32() */
 699         dtime = le32_to_cpu(raw_inode->i_dtime);
 700         now = ktime_get_real_seconds();
 701         if (buffer_dirty(bh))
 702                 recentcy += RECENTCY_DIRTY;
 703
 704         if (dtime && time_before32(dtime, now) &&
 705             time_before32(now, dtime + recentcy))
 706                 ret = 1;
 707 out:
 708         brelse(bh);
 709         return ret;
 710 }
 711
 712 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 713                           struct buffer_head *bitmap, unsigned long *ino)
 714 {
 715 next:
 716         *ino = ext4_find_next_zero_bit((unsigned long *)
 717                                        bitmap->b_data,
 718                                        EXT4_INODES_PER_GROUP(sb), *ino);
 719         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 720                 return 0;
 721
 722         if ((EXT4_SB(sb)->s_journal == NULL) &&
 723             recently_deleted(sb, group, *ino)) {
 724                 *ino = *ino + 1;
 725                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 726                         goto next;
 727                 return 0;
 728         }
 729
 730         return 1;
 731 }
 732
 733 /*
 734  * There are two policies for allocating an inode.  If the new inode is
 735  * a directory, then a forward search is made for a block group with both
 736  * free space and a low directory-to-inode ratio; if that fails, then of
 737  * the groups with above-average free space, that group with the fewest
 738  * directories already is chosen.
 739  *
 740  * For other inodes, search forward from the parent directory's block
 741  * group to find a free inode.
 742  */
 743 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 744                                umode_t mode, const struct qstr *qstr,
 745                                __u32 goal, uid_t *owner, __u32 i_flags,
 746                                int handle_type, unsigned int line_no,
 747                                int nblocks)
 748 {
 749         struct super_block *sb;
 750         struct buffer_head *inode_bitmap_bh = NULL;
 751         struct buffer_head *group_desc_bh;
 752         ext4_group_t ngroups, group = 0;
 753         unsigned long ino = 0;
 754         struct inode *inode;
 755         struct ext4_group_desc *gdp = NULL;
 756         struct ext4_inode_info *ei;
 757         struct ext4_sb_info *sbi;
 758         int ret2, err;
 759         struct inode *ret;
 760         ext4_group_t i;
 761         ext4_group_t flex_group;
 762         struct ext4_group_info *grp;
 763         int encrypt = 0;
 764
 765         /* Cannot create files in a deleted directory */
 766         if (!dir || !dir->i_nlink)
 767                 return ERR_PTR(-EPERM);
 768
 769         sb = dir->i_sb;
 770         sbi = EXT4_SB(sb);
 771
 772         if (unlikely(ext4_forced_shutdown(sbi)))
 773                 return ERR_PTR(-EIO);
 774
 775         if ((IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
 776             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
 777             !(i_flags & EXT4_EA_INODE_FL)) {
 778                 err = fscrypt_get_encryption_info(dir);
 779                 if (err)
 780                         return ERR_PTR(err);
 781                 if (!fscrypt_has_encryption_key(dir))
 782                         return ERR_PTR(-ENOKEY);
 783                 encrypt = 1;
 784         }
 785
 786         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 787 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 788                 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 789
 790                 if (IS_ERR(p))
 791                         return ERR_CAST(p);
 792                 if (p) {
 793                         int acl_size = p->a_count * sizeof(ext4_acl_entry);
 794
 795                         nblocks += (S_ISDIR(mode) ? 2 : 1) *
 796                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 797                                         NULL /* block_bh */, acl_size,
 798                                         true /* is_create */);
 799                         posix_acl_release(p);
 800                 }
 801 #endif
 802
 803 #ifdef CONFIG_SECURITY
 804                 {
 805                         int num_security_xattrs = 1;
 806
 807 #ifdef CONFIG_INTEGRITY
 808                         num_security_xattrs++;
 809 #endif
 810                         /*
 811                          * We assume that security xattrs are never
 812                          * more than 1k.  In practice they are under
 813                          * 128 bytes.
 814                          */
 815                         nblocks += num_security_xattrs *
 816                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 817                                         NULL /* block_bh */, 1024,
 818                                         true /* is_create */);
 819                 }
 820 #endif
 821                 if (encrypt)
 822                         nblocks += __ext4_xattr_set_credits(sb,
 823                                         NULL /* inode */, NULL /* block_bh */,
 824                                         FSCRYPT_SET_CONTEXT_MAX_SIZE,
 825                                         true /* is_create */);
 826         }
 827
 828         ngroups = ext4_get_groups_count(sb);
 829         trace_ext4_request_inode(dir, mode);
 830         inode = new_inode(sb);
 831         if (!inode)
 832                 return ERR_PTR(-ENOMEM);
 833         ei = EXT4_I(inode);
 834
 835         /*
 836          * Initialize owners and quota early so that we don't have to account
 837          * for quota initialization worst case in standard inode creating
 838          * transaction
 839          */
 840         if (owner) {
 841                 inode->i_mode = mode;
 842                 i_uid_write(inode, owner[0]);
 843                 i_gid_write(inode, owner[1]);
 844         } else if (test_opt(sb, GRPID)) {
 845                 inode->i_mode = mode;
 846                 inode->i_uid = current_fsuid();
 847                 inode->i_gid = dir->i_gid;
 848         } else
 849                 inode_init_owner(inode, dir, mode);
 850
 851         if (ext4_has_feature_project(sb) &&
 852             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 853                 ei->i_projid = EXT4_I(dir)->i_projid;
 854         else
 855                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 856
 857         err = dquot_initialize(inode);
 858         if (err)
 859                 goto out;
 860
 861         if (!goal)
 862                 goal = sbi->s_inode_goal;
 863
 864         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
 865                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
 866                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
 867                 ret2 = 0;
 868                 goto got_group;
 869         }
 870
 871         if (S_ISDIR(mode))
 872                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
 873         else
 874                 ret2 = find_group_other(sb, dir, &group, mode);
 875
 876 got_group:
 877         EXT4_I(dir)->i_last_alloc_group = group;
 878         err = -ENOSPC;
 879         if (ret2 == -1)
 880                 goto out;
 881
 882         /*
 883          * Normally we will only go through one pass of this loop,
 884          * unless we get unlucky and it turns out the group we selected
 885          * had its last inode grabbed by someone else.
 886          */
 887         for (i = 0; i < ngroups; i++, ino = 0) {
 888                 err = -EIO;
 889
 890                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 891                 if (!gdp)
 892                         goto out;
 893
 894                 /*
 895                  * Check free inodes count before loading bitmap.
 896                  */
 897                 if (ext4_free_inodes_count(sb, gdp) == 0)
 898                         goto next_group;
 899
 900                 grp = ext4_get_group_info(sb, group);
 901                 /* Skip groups with already-known suspicious inode tables */
 902                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 903                         goto next_group;
 904
 905                 brelse(inode_bitmap_bh);
 906                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 907                 /* Skip groups with suspicious inode tables */
 908                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 909                     IS_ERR(inode_bitmap_bh)) {
 910                         inode_bitmap_bh = NULL;
 911                         goto next_group;
 912                 }
 913
 914 repeat_in_this_group:
 915                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 916                 if (!ret2)
 917                         goto next_group;
 918
 919                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 920                         ext4_error(sb, "reserved inode found cleared - "
 921                                    "inode=%lu", ino + 1);
 922                         ext4_mark_group_bitmap_corrupted(sb, group,
 923                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 924                         goto next_group;
 925                 }
 926
 927                 if (!handle) {
 928                         BUG_ON(nblocks <= 0);
 929                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
 930                                  handle_type, nblocks, 0,
 931                                  ext4_trans_default_revoke_credits(sb));
 932                         if (IS_ERR(handle)) {
 933                                 err = PTR_ERR(handle);
 934                                 ext4_std_error(sb, err);
 935                                 goto out;
 936                         }
 937                 }
 938                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
 939                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
 940                 if (err) {
 941                         ext4_std_error(sb, err);
 942                         goto out;
 943                 }
 944                 ext4_lock_group(sb, group);
 945                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
 946                 if (ret2) {
 947                         /* Someone already took the bit. Repeat the search
 948                          * with lock held.
 949                          */
 950                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 951                         if (ret2) {
 952                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
 953                                 ret2 = 0;
 954                         } else {
 955                                 ret2 = 1; /* we didn't grab the inode */
 956                         }
 957                 }
 958                 ext4_unlock_group(sb, group);
 959                 ino++;          /* the inode bitmap is zero-based */
 960                 if (!ret2)
 961                         goto got; /* we grabbed the inode! */
 962
 963                 if (ino < EXT4_INODES_PER_GROUP(sb))
 964                         goto repeat_in_this_group;
 965 next_group:
 966                 if (++group == ngroups)
 967                         group = 0;
 968         }
 969         err = -ENOSPC;
 970         goto out;
 971
 972 got:
 973         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 974         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
 975         if (err) {
 976                 ext4_std_error(sb, err);
 977                 goto out;
 978         }
 979
 980         BUFFER_TRACE(group_desc_bh, "get_write_access");
 981         err = ext4_journal_get_write_access(handle, group_desc_bh);
 982         if (err) {
 983                 ext4_std_error(sb, err);
 984                 goto out;
 985         }
 986
 987         /* We may have to initialize the block bitmap if it isn't already */
 988         if (ext4_has_group_desc_csum(sb) &&
 989             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 990                 struct buffer_head *block_bitmap_bh;
 991
 992                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
 993                 if (IS_ERR(block_bitmap_bh)) {
 994                         err = PTR_ERR(block_bitmap_bh);
 995                         goto out;
 996                 }
 997                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
 998                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
 999                 if (err) {
1000                         brelse(block_bitmap_bh);
1001                         ext4_std_error(sb, err);
1002                         goto out;
1003                 }
1004
1005                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1006                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1007
1008                 /* recheck and clear flag under lock if we still need to */
1009                 ext4_lock_group(sb, group);
1010                 if (ext4_has_group_desc_csum(sb) &&
1011                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1012                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1013                         ext4_free_group_clusters_set(sb, gdp,
1014                                 ext4_free_clusters_after_init(sb, group, gdp));
1015                         ext4_block_bitmap_csum_set(sb, group, gdp,
1016                                                    block_bitmap_bh);
1017                         ext4_group_desc_csum_set(sb, group, gdp);
1018                 }
1019                 ext4_unlock_group(sb, group);
1020                 brelse(block_bitmap_bh);
1021
1022                 if (err) {
1023                         ext4_std_error(sb, err);
1024                         goto out;
1025                 }
1026         }
1027
1028         /* Update the relevant bg descriptor fields */
1029         if (ext4_has_group_desc_csum(sb)) {
1030                 int free;
1031                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1032
1033                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1034                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1035                 free = EXT4_INODES_PER_GROUP(sb) -
1036                         ext4_itable_unused_count(sb, gdp);
1037                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1038                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1039                         free = 0;
1040                 }
1041                 /*
1042                  * Check the relative inode number against the last used
1043                  * relative inode number in this group. if it is greater
1044                  * we need to update the bg_itable_unused count
1045                  */
1046                 if (ino > free)
1047                         ext4_itable_unused_set(sb, gdp,
1048                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1049                 up_read(&grp->alloc_sem);
1050         } else {
1051                 ext4_lock_group(sb, group);
1052         }
1053
1054         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1055         if (S_ISDIR(mode)) {
1056                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1057                 if (sbi->s_log_groups_per_flex) {
1058                         ext4_group_t f = ext4_flex_group(sbi, group);
1059
1060                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1061                                                         f)->used_dirs);
1062                 }
1063         }
1064         if (ext4_has_group_desc_csum(sb)) {
1065                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1066                                            EXT4_INODES_PER_GROUP(sb) / 8);
1067                 ext4_group_desc_csum_set(sb, group, gdp);
1068         }
1069         ext4_unlock_group(sb, group);
1070
1071         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1072         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1073         if (err) {
1074                 ext4_std_error(sb, err);
1075                 goto out;
1076         }
1077
1078         percpu_counter_dec(&sbi->s_freeinodes_counter);
1079         if (S_ISDIR(mode))
1080                 percpu_counter_inc(&sbi->s_dirs_counter);
1081
1082         if (sbi->s_log_groups_per_flex) {
1083                 flex_group = ext4_flex_group(sbi, group);
1084                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1085                                                 flex_group)->free_inodes);
1086         }
1087
1088         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1089         /* This is the optimal IO size (for stat), not the fs block size */
1090         inode->i_blocks = 0;
1091         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1092         ei->i_crtime = inode->i_mtime;
1093
1094         memset(ei->i_data, 0, sizeof(ei->i_data));
1095         ei->i_dir_start_lookup = 0;
1096         ei->i_disksize = 0;
1097
1098         /* Don't inherit extent flag from directory, amongst others. */
1099         ei->i_flags =
1100                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1101         ei->i_flags |= i_flags;
1102         ei->i_file_acl = 0;
1103         ei->i_dtime = 0;
1104         ei->i_block_group = group;
1105         ei->i_last_alloc_group = ~0;
1106
1107         ext4_set_inode_flags(inode);
1108         if (IS_DIRSYNC(inode))
1109                 ext4_handle_sync(handle);
1110         if (insert_inode_locked(inode) < 0) {
1111                 /*
1112                  * Likely a bitmap corruption causing inode to be allocated
1113                  * twice.
1114                  */
1115                 err = -EIO;
1116                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1117                            inode->i_ino);
1118                 ext4_mark_group_bitmap_corrupted(sb, group,
1119                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1120                 goto out;
1121         }
1122         inode->i_generation = prandom_u32();
1123
1124         /* Precompute checksum seed for inode metadata */
1125         if (ext4_has_metadata_csum(sb)) {
1126                 __u32 csum;
1127                 __le32 inum = cpu_to_le32(inode->i_ino);
1128                 __le32 gen = cpu_to_le32(inode->i_generation);
1129                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1130                                    sizeof(inum));
1131                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1132                                               sizeof(gen));
1133         }
1134
1135         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1136         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1137
1138         ei->i_extra_isize = sbi->s_want_extra_isize;
1139         ei->i_inline_off = 0;
1140         if (ext4_has_feature_inline_data(sb))
1141                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1142         ret = inode;
1143         err = dquot_alloc_inode(inode);
1144         if (err)
1145                 goto fail_drop;
1146
1147         /*
1148          * Since the encryption xattr will always be unique, create it first so
1149          * that it's less likely to end up in an external xattr block and
1150          * prevent its deduplication.
1151          */
1152         if (encrypt) {
1153                 err = fscrypt_inherit_context(dir, inode, handle, true);
1154                 if (err)
1155                         goto fail_free_drop;
1156         }
1157
1158         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1159                 err = ext4_init_acl(handle, inode, dir);
1160                 if (err)
1161                         goto fail_free_drop;
1162
1163                 err = ext4_init_security(handle, inode, dir, qstr);
1164                 if (err)
1165                         goto fail_free_drop;
1166         }
1167
1168         if (ext4_has_feature_extents(sb)) {
1169                 /* set extent flag only for directory, file and normal symlink*/
1170                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1171                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1172                         ext4_ext_tree_init(handle, inode);
1173                 }
1174         }
1175
1176         if (ext4_handle_valid(handle)) {
1177                 ei->i_sync_tid = handle->h_transaction->t_tid;
1178                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1179         }
1180
1181         err = ext4_mark_inode_dirty(handle, inode);
1182         if (err) {
1183                 ext4_std_error(sb, err);
1184                 goto fail_free_drop;
1185         }
1186
1187         ext4_debug("allocating inode %lu\n", inode->i_ino);
1188         trace_ext4_allocate_inode(inode, dir, mode);
1189         brelse(inode_bitmap_bh);
1190         return ret;
1191
1192 fail_free_drop:
1193         dquot_free_inode(inode);
1194 fail_drop:
1195         clear_nlink(inode);
1196         unlock_new_inode(inode);
1197 out:
1198         dquot_drop(inode);
1199         inode->i_flags |= S_NOQUOTA;
1200         iput(inode);
1201         brelse(inode_bitmap_bh);
1202         return ERR_PTR(err);
1203 }
1204
1205 /* Verify that we are loading a valid orphan from disk */
1206 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1207 {
1208         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1209         ext4_group_t block_group;
1210         int bit;
1211         struct buffer_head *bitmap_bh = NULL;
1212         struct inode *inode = NULL;
1213         int err = -EFSCORRUPTED;
1214
1215         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1216                 goto bad_orphan;
1217
1218         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1219         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1220         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1221         if (IS_ERR(bitmap_bh))
1222                 return ERR_CAST(bitmap_bh);
1223
1224         /* Having the inode bit set should be a 100% indicator that this
1225          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1226          * inodes that were being truncated, so we can't check i_nlink==0.
1227          */
1228         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1229                 goto bad_orphan;
1230
1231         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1232         if (IS_ERR(inode)) {
1233                 err = PTR_ERR(inode);
1234                 ext4_set_errno(sb, -err);
1235                 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1236                            ino, err);
1237                 return inode;
1238         }
1239
1240         /*
1241          * If the orphans has i_nlinks > 0 then it should be able to
1242          * be truncated, otherwise it won't be removed from the orphan
1243          * list during processing and an infinite loop will result.
1244          * Similarly, it must not be a bad inode.
1245          */
1246         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1247             is_bad_inode(inode))
1248                 goto bad_orphan;
1249
1250         if (NEXT_ORPHAN(inode) > max_ino)
1251                 goto bad_orphan;
1252         brelse(bitmap_bh);
1253         return inode;
1254
1255 bad_orphan:
1256         ext4_error(sb, "bad orphan inode %lu", ino);
1257         if (bitmap_bh)
1258                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1259                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1260                        ext4_test_bit(bit, bitmap_bh->b_data));
1261         if (inode) {
1262                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1263                        is_bad_inode(inode));
1264                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1265                        NEXT_ORPHAN(inode));
1266                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1267                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1268                 /* Avoid freeing blocks if we got a bad deleted inode */
1269                 if (inode->i_nlink == 0)
1270                         inode->i_blocks = 0;
1271                 iput(inode);
1272         }
1273         brelse(bitmap_bh);
1274         return ERR_PTR(err);
1275 }
1276
1277 unsigned long ext4_count_free_inodes(struct super_block *sb)
1278 {
1279         unsigned long desc_count;
1280         struct ext4_group_desc *gdp;
1281         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1282 #ifdef EXT4FS_DEBUG
1283         struct ext4_super_block *es;
1284         unsigned long bitmap_count, x;
1285         struct buffer_head *bitmap_bh = NULL;
1286
1287         es = EXT4_SB(sb)->s_es;
1288         desc_count = 0;
1289         bitmap_count = 0;
1290         gdp = NULL;
1291         for (i = 0; i < ngroups; i++) {
1292                 gdp = ext4_get_group_desc(sb, i, NULL);
1293                 if (!gdp)
1294                         continue;
1295                 desc_count += ext4_free_inodes_count(sb, gdp);
1296                 brelse(bitmap_bh);
1297                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1298                 if (IS_ERR(bitmap_bh)) {
1299                         bitmap_bh = NULL;
1300                         continue;
1301                 }
1302
1303                 x = ext4_count_free(bitmap_bh->b_data,
1304                                     EXT4_INODES_PER_GROUP(sb) / 8);
1305                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1306                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1307                 bitmap_count += x;
1308         }
1309         brelse(bitmap_bh);
1310         printk(KERN_DEBUG "ext4_count_free_inodes: "
1311                "stored = %u, computed = %lu, %lu\n",
1312                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1313         return desc_count;
1314 #else
1315         desc_count = 0;
1316         for (i = 0; i < ngroups; i++) {
1317                 gdp = ext4_get_group_desc(sb, i, NULL);
1318                 if (!gdp)
1319                         continue;
1320                 desc_count += ext4_free_inodes_count(sb, gdp);
1321                 cond_resched();
1322         }
1323         return desc_count;
1324 #endif
1325 }
1326
1327 /* Called at mount-time, super-block is locked */
1328 unsigned long ext4_count_dirs(struct super_block * sb)
1329 {
1330         unsigned long count = 0;
1331         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1332
1333         for (i = 0; i < ngroups; i++) {
1334                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1335                 if (!gdp)
1336                         continue;
1337                 count += ext4_used_dirs_count(sb, gdp);
1338         }
1339         return count;
1340 }
1341
1342 /*
1343  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1344  * inode table. Must be called without any spinlock held. The only place
1345  * where it is called from on active part of filesystem is ext4lazyinit
1346  * thread, so we do not need any special locks, however we have to prevent
1347  * inode allocation from the current group, so we take alloc_sem lock, to
1348  * block ext4_new_inode() until we are finished.
1349  */
1350 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1351                                  int barrier)
1352 {
1353         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1354         struct ext4_sb_info *sbi = EXT4_SB(sb);
1355         struct ext4_group_desc *gdp = NULL;
1356         struct buffer_head *group_desc_bh;
1357         handle_t *handle;
1358         ext4_fsblk_t blk;
1359         int num, ret = 0, used_blks = 0;
1360
1361         /* This should not happen, but just to be sure check this */
1362         if (sb_rdonly(sb)) {
1363                 ret = 1;
1364                 goto out;
1365         }
1366
1367         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1368         if (!gdp)
1369                 goto out;
1370
1371         /*
1372          * We do not need to lock this, because we are the only one
1373          * handling this flag.
1374          */
1375         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1376                 goto out;
1377
1378         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1379         if (IS_ERR(handle)) {
1380                 ret = PTR_ERR(handle);
1381                 goto out;
1382         }
1383
1384         down_write(&grp->alloc_sem);
1385         /*
1386          * If inode bitmap was already initialized there may be some
1387          * used inodes so we need to skip blocks with used inodes in
1388          * inode table.
1389          */
1390         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1391                 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1392                             ext4_itable_unused_count(sb, gdp)),
1393                             sbi->s_inodes_per_block);
1394
1395         if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) ||
1396             ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) -
1397                                ext4_itable_unused_count(sb, gdp)) <
1398                               EXT4_FIRST_INO(sb)))) {
1399                 ext4_error(sb, "Something is wrong with group %u: "
1400                            "used itable blocks: %d; "
1401                            "itable unused count: %u",
1402                            group, used_blks,
1403                            ext4_itable_unused_count(sb, gdp));
1404                 ret = 1;
1405                 goto err_out;
1406         }
1407
1408         blk = ext4_inode_table(sb, gdp) + used_blks;
1409         num = sbi->s_itb_per_group - used_blks;
1410
1411         BUFFER_TRACE(group_desc_bh, "get_write_access");
1412         ret = ext4_journal_get_write_access(handle,
1413                                             group_desc_bh);
1414         if (ret)
1415                 goto err_out;
1416
1417         /*
1418          * Skip zeroout if the inode table is full. But we set the ZEROED
1419          * flag anyway, because obviously, when it is full it does not need
1420          * further zeroing.
1421          */
1422         if (unlikely(num == 0))
1423                 goto skip_zeroout;
1424
1425         ext4_debug("going to zero out inode table in group %d\n",
1426                    group);
1427         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1428         if (ret < 0)
1429                 goto err_out;
1430         if (barrier)
1431                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1432
1433 skip_zeroout:
1434         ext4_lock_group(sb, group);
1435         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1436         ext4_group_desc_csum_set(sb, group, gdp);
1437         ext4_unlock_group(sb, group);
1438
1439         BUFFER_TRACE(group_desc_bh,
1440                      "call ext4_handle_dirty_metadata");
1441         ret = ext4_handle_dirty_metadata(handle, NULL,
1442                                          group_desc_bh);
1443
1444 err_out:
1445         up_write(&grp->alloc_sem);
1446         ext4_journal_stop(handle);
1447 out:
1448         return ret;
1449 }