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 ([email protected])
   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 ([email protected]), 1993
  12  *  Big-endian to little-endian byte-swapping/bitmaps by
  13  *        David S. Miller ([email protected]), 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;
  86
  87         if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
  88                 return 0;
  89
  90         if (buffer_verified(bh))
  91                 return 0;
  92
  93         grp = ext4_get_group_info(sb, block_group);
  94         if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
  95                 return -EFSCORRUPTED;
  96
  97         ext4_lock_group(sb, block_group);
  98         if (buffer_verified(bh))
  99                 goto verified;
 100         blk = ext4_inode_bitmap(sb, desc);
 101         if (!ext4_inode_bitmap_csum_verify(sb, desc, bh) ||
 102             ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
 103                 ext4_unlock_group(sb, block_group);
 104                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 105                            "inode_bitmap = %llu", block_group, blk);
 106                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 107                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 108                 return -EFSBADCRC;
 109         }
 110         set_buffer_verified(bh);
 111 verified:
 112         ext4_unlock_group(sb, block_group);
 113         return 0;
 114 }
 115
 116 /*
 117  * Read the inode allocation bitmap for a given block_group, reading
 118  * into the specified slot in the superblock's bitmap cache.
 119  *
 120  * Return buffer_head of bitmap on success, or an ERR_PTR on error.
 121  */
 122 static struct buffer_head *
 123 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 124 {
 125         struct ext4_group_desc *desc;
 126         struct ext4_sb_info *sbi = EXT4_SB(sb);
 127         struct buffer_head *bh = NULL;
 128         ext4_fsblk_t bitmap_blk;
 129         int err;
 130
 131         desc = ext4_get_group_desc(sb, block_group, NULL);
 132         if (!desc)
 133                 return ERR_PTR(-EFSCORRUPTED);
 134
 135         bitmap_blk = ext4_inode_bitmap(sb, desc);
 136         if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
 137             (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
 138                 ext4_error(sb, "Invalid inode bitmap blk %llu in "
 139                            "block_group %u", bitmap_blk, block_group);
 140                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 141                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 142                 return ERR_PTR(-EFSCORRUPTED);
 143         }
 144         bh = sb_getblk(sb, bitmap_blk);
 145         if (unlikely(!bh)) {
 146                 ext4_warning(sb, "Cannot read inode bitmap - "
 147                              "block_group = %u, inode_bitmap = %llu",
 148                              block_group, bitmap_blk);
 149                 return ERR_PTR(-ENOMEM);
 150         }
 151         if (bitmap_uptodate(bh))
 152                 goto verify;
 153
 154         lock_buffer(bh);
 155         if (bitmap_uptodate(bh)) {
 156                 unlock_buffer(bh);
 157                 goto verify;
 158         }
 159
 160         ext4_lock_group(sb, block_group);
 161         if (ext4_has_group_desc_csum(sb) &&
 162             (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
 163                 if (block_group == 0) {
 164                         ext4_unlock_group(sb, block_group);
 165                         unlock_buffer(bh);
 166                         ext4_error(sb, "Inode bitmap for bg 0 marked "
 167                                    "uninitialized");
 168                         err = -EFSCORRUPTED;
 169                         goto out;
 170                 }
 171                 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 172                 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
 173                                      sb->s_blocksize * 8, bh->b_data);
 174                 set_bitmap_uptodate(bh);
 175                 set_buffer_uptodate(bh);
 176                 set_buffer_verified(bh);
 177                 ext4_unlock_group(sb, block_group);
 178                 unlock_buffer(bh);
 179                 return bh;
 180         }
 181         ext4_unlock_group(sb, block_group);
 182
 183         if (buffer_uptodate(bh)) {
 184                 /*
 185                  * if not uninit if bh is uptodate,
 186                  * bitmap is also uptodate
 187                  */
 188                 set_bitmap_uptodate(bh);
 189                 unlock_buffer(bh);
 190                 goto verify;
 191         }
 192         /*
 193          * submit the buffer_head for reading
 194          */
 195         trace_ext4_load_inode_bitmap(sb, block_group);
 196         ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
 197         ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
 198         if (!buffer_uptodate(bh)) {
 199                 put_bh(bh);
 200                 ext4_error_err(sb, EIO, "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         if (IS_ERR(bitmap_bh)) {
 289                 fatal = PTR_ERR(bitmap_bh);
 290                 bitmap_bh = NULL;
 291                 goto error_return;
 292         }
 293         if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
 294                 grp = ext4_get_group_info(sb, block_group);
 295                 if (!grp || unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 296                         fatal = -EFSCORRUPTED;
 297                         goto error_return;
 298                 }
 299         }
 300
 301         BUFFER_TRACE(bitmap_bh, "get_write_access");
 302         fatal = ext4_journal_get_write_access(handle, sb, bitmap_bh,
 303                                               EXT4_JTR_NONE);
 304         if (fatal)
 305                 goto error_return;
 306
 307         fatal = -ESRCH;
 308         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 309         if (gdp) {
 310                 BUFFER_TRACE(bh2, "get_write_access");
 311                 fatal = ext4_journal_get_write_access(handle, sb, bh2,
 312                                                       EXT4_JTR_NONE);
 313         }
 314         ext4_lock_group(sb, block_group);
 315         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 316         if (fatal || !cleared) {
 317                 ext4_unlock_group(sb, block_group);
 318                 goto out;
 319         }
 320
 321         count = ext4_free_inodes_count(sb, gdp) + 1;
 322         ext4_free_inodes_set(sb, gdp, count);
 323         if (is_directory) {
 324                 count = ext4_used_dirs_count(sb, gdp) - 1;
 325                 ext4_used_dirs_set(sb, gdp, count);
 326                 if (percpu_counter_initialized(&sbi->s_dirs_counter))
 327                         percpu_counter_dec(&sbi->s_dirs_counter);
 328         }
 329         ext4_inode_bitmap_csum_set(sb, gdp, bitmap_bh);
 330         ext4_group_desc_csum_set(sb, block_group, gdp);
 331         ext4_unlock_group(sb, block_group);
 332
 333         if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
 334                 percpu_counter_inc(&sbi->s_freeinodes_counter);
 335         if (sbi->s_log_groups_per_flex) {
 336                 struct flex_groups *fg;
 337
 338                 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
 339                                          ext4_flex_group(sbi, block_group));
 340                 atomic_inc(&fg->free_inodes);
 341                 if (is_directory)
 342                         atomic_dec(&fg->used_dirs);
 343         }
 344         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
 345         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
 346 out:
 347         if (cleared) {
 348                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
 349                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 350                 if (!fatal)
 351                         fatal = err;
 352         } else {
 353                 ext4_error(sb, "bit already cleared for inode %lu", ino);
 354                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 355                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 356         }
 357
 358 error_return:
 359         brelse(bitmap_bh);
 360         ext4_std_error(sb, fatal);
 361 }
 362
 363 struct orlov_stats {
 364         __u64 free_clusters;
 365         __u32 free_inodes;
 366         __u32 used_dirs;
 367 };
 368
 369 /*
 370  * Helper function for Orlov's allocator; returns critical information
 371  * for a particular block group or flex_bg.  If flex_size is 1, then g
 372  * is a block group number; otherwise it is flex_bg number.
 373  */
 374 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 375                             int flex_size, struct orlov_stats *stats)
 376 {
 377         struct ext4_group_desc *desc;
 378
 379         if (flex_size > 1) {
 380                 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
 381                                                              s_flex_groups, g);
 382                 stats->free_inodes = atomic_read(&fg->free_inodes);
 383                 stats->free_clusters = atomic64_read(&fg->free_clusters);
 384                 stats->used_dirs = atomic_read(&fg->used_dirs);
 385                 return;
 386         }
 387
 388         desc = ext4_get_group_desc(sb, g, NULL);
 389         if (desc) {
 390                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 391                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 392                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 393         } else {
 394                 stats->free_inodes = 0;
 395                 stats->free_clusters = 0;
 396                 stats->used_dirs = 0;
 397         }
 398 }
 399
 400 /*
 401  * Orlov's allocator for directories.
 402  *
 403  * We always try to spread first-level directories.
 404  *
 405  * If there are blockgroups with both free inodes and free clusters counts
 406  * not worse than average we return one with smallest directory count.
 407  * Otherwise we simply return a random group.
 408  *
 409  * For the rest rules look so:
 410  *
 411  * It's OK to put directory into a group unless
 412  * it has too many directories already (max_dirs) or
 413  * it has too few free inodes left (min_inodes) or
 414  * it has too few free clusters left (min_clusters) or
 415  * Parent's group is preferred, if it doesn't satisfy these
 416  * conditions we search cyclically through the rest. If none
 417  * of the groups look good we just look for a group with more
 418  * free inodes than average (starting at parent's group).
 419  */
 420
 421 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 422                             ext4_group_t *group, umode_t mode,
 423                             const struct qstr *qstr)
 424 {
 425         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 426         struct ext4_sb_info *sbi = EXT4_SB(sb);
 427         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 428         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 429         unsigned int freei, avefreei, grp_free;
 430         ext4_fsblk_t freec, avefreec;
 431         unsigned int ndirs;
 432         int max_dirs, min_inodes;
 433         ext4_grpblk_t min_clusters;
 434         ext4_group_t i, grp, g, ngroups;
 435         struct ext4_group_desc *desc;
 436         struct orlov_stats stats;
 437         int flex_size = ext4_flex_bg_size(sbi);
 438         struct dx_hash_info hinfo;
 439
 440         ngroups = real_ngroups;
 441         if (flex_size > 1) {
 442                 ngroups = (real_ngroups + flex_size - 1) >>
 443                         sbi->s_log_groups_per_flex;
 444                 parent_group >>= sbi->s_log_groups_per_flex;
 445         }
 446
 447         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 448         avefreei = freei / ngroups;
 449         freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
 450         avefreec = freec;
 451         do_div(avefreec, ngroups);
 452         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 453
 454         if (S_ISDIR(mode) &&
 455             ((parent == d_inode(sb->s_root)) ||
 456              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 457                 int best_ndir = inodes_per_group;
 458                 int ret = -1;
 459
 460                 if (qstr) {
 461                         hinfo.hash_version = DX_HASH_HALF_MD4;
 462                         hinfo.seed = sbi->s_hash_seed;
 463                         ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 464                         parent_group = hinfo.hash % ngroups;
 465                 } else
 466                         parent_group = get_random_u32_below(ngroups);
 467                 for (i = 0; i < ngroups; i++) {
 468                         g = (parent_group + i) % ngroups;
 469                         get_orlov_stats(sb, g, flex_size, &stats);
 470                         if (!stats.free_inodes)
 471                                 continue;
 472                         if (stats.used_dirs >= best_ndir)
 473                                 continue;
 474                         if (stats.free_inodes < avefreei)
 475                                 continue;
 476                         if (stats.free_clusters < avefreec)
 477                                 continue;
 478                         grp = g;
 479                         ret = 0;
 480                         best_ndir = stats.used_dirs;
 481                 }
 482                 if (ret)
 483                         goto fallback;
 484         found_flex_bg:
 485                 if (flex_size == 1) {
 486                         *group = grp;
 487                         return 0;
 488                 }
 489
 490                 /*
 491                  * We pack inodes at the beginning of the flexgroup's
 492                  * inode tables.  Block allocation decisions will do
 493                  * something similar, although regular files will
 494                  * start at 2nd block group of the flexgroup.  See
 495                  * ext4_ext_find_goal() and ext4_find_near().
 496                  */
 497                 grp *= flex_size;
 498                 for (i = 0; i < flex_size; i++) {
 499                         if (grp+i >= real_ngroups)
 500                                 break;
 501                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 502                         if (desc && ext4_free_inodes_count(sb, desc)) {
 503                                 *group = grp+i;
 504                                 return 0;
 505                         }
 506                 }
 507                 goto fallback;
 508         }
 509
 510         max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
 511         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 512         if (min_inodes < 1)
 513                 min_inodes = 1;
 514         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 515         if (min_clusters < 0)
 516                 min_clusters = 0;
 517
 518         /*
 519          * Start looking in the flex group where we last allocated an
 520          * inode for this parent directory
 521          */
 522         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 523                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 524                 if (flex_size > 1)
 525                         parent_group >>= sbi->s_log_groups_per_flex;
 526         }
 527
 528         for (i = 0; i < ngroups; i++) {
 529                 grp = (parent_group + i) % ngroups;
 530                 get_orlov_stats(sb, grp, flex_size, &stats);
 531                 if (stats.used_dirs >= max_dirs)
 532                         continue;
 533                 if (stats.free_inodes < min_inodes)
 534                         continue;
 535                 if (stats.free_clusters < min_clusters)
 536                         continue;
 537                 goto found_flex_bg;
 538         }
 539
 540 fallback:
 541         ngroups = real_ngroups;
 542         avefreei = freei / ngroups;
 543 fallback_retry:
 544         parent_group = EXT4_I(parent)->i_block_group;
 545         for (i = 0; i < ngroups; i++) {
 546                 grp = (parent_group + i) % ngroups;
 547                 desc = ext4_get_group_desc(sb, grp, NULL);
 548                 if (desc) {
 549                         grp_free = ext4_free_inodes_count(sb, desc);
 550                         if (grp_free && grp_free >= avefreei) {
 551                                 *group = grp;
 552                                 return 0;
 553                         }
 554                 }
 555         }
 556
 557         if (avefreei) {
 558                 /*
 559                  * The free-inodes counter is approximate, and for really small
 560                  * filesystems the above test can fail to find any blockgroups
 561                  */
 562                 avefreei = 0;
 563                 goto fallback_retry;
 564         }
 565
 566         return -1;
 567 }
 568
 569 static int find_group_other(struct super_block *sb, struct inode *parent,
 570                             ext4_group_t *group, umode_t mode)
 571 {
 572         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 573         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 574         struct ext4_group_desc *desc;
 575         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 576
 577         /*
 578          * Try to place the inode is the same flex group as its
 579          * parent.  If we can't find space, use the Orlov algorithm to
 580          * find another flex group, and store that information in the
 581          * parent directory's inode information so that use that flex
 582          * group for future allocations.
 583          */
 584         if (flex_size > 1) {
 585                 int retry = 0;
 586
 587         try_again:
 588                 parent_group &= ~(flex_size-1);
 589                 last = parent_group + flex_size;
 590                 if (last > ngroups)
 591                         last = ngroups;
 592                 for  (i = parent_group; i < last; i++) {
 593                         desc = ext4_get_group_desc(sb, i, NULL);
 594                         if (desc && ext4_free_inodes_count(sb, desc)) {
 595                                 *group = i;
 596                                 return 0;
 597                         }
 598                 }
 599                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 600                         retry = 1;
 601                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 602                         goto try_again;
 603                 }
 604                 /*
 605                  * If this didn't work, use the Orlov search algorithm
 606                  * to find a new flex group; we pass in the mode to
 607                  * avoid the topdir algorithms.
 608                  */
 609                 *group = parent_group + flex_size;
 610                 if (*group > ngroups)
 611                         *group = 0;
 612                 return find_group_orlov(sb, parent, group, mode, NULL);
 613         }
 614
 615         /*
 616          * Try to place the inode in its parent directory
 617          */
 618         *group = parent_group;
 619         desc = ext4_get_group_desc(sb, *group, NULL);
 620         if (desc && ext4_free_inodes_count(sb, desc) &&
 621             ext4_free_group_clusters(sb, desc))
 622                 return 0;
 623
 624         /*
 625          * We're going to place this inode in a different blockgroup from its
 626          * parent.  We want to cause files in a common directory to all land in
 627          * the same blockgroup.  But we want files which are in a different
 628          * directory which shares a blockgroup with our parent to land in a
 629          * different blockgroup.
 630          *
 631          * So add our directory's i_ino into the starting point for the hash.
 632          */
 633         *group = (*group + parent->i_ino) % ngroups;
 634
 635         /*
 636          * Use a quadratic hash to find a group with a free inode and some free
 637          * blocks.
 638          */
 639         for (i = 1; i < ngroups; i <<= 1) {
 640                 *group += i;
 641                 if (*group >= ngroups)
 642                         *group -= ngroups;
 643                 desc = ext4_get_group_desc(sb, *group, NULL);
 644                 if (desc && ext4_free_inodes_count(sb, desc) &&
 645                     ext4_free_group_clusters(sb, desc))
 646                         return 0;
 647         }
 648
 649         /*
 650          * That failed: try linear search for a free inode, even if that group
 651          * has no free blocks.
 652          */
 653         *group = parent_group;
 654         for (i = 0; i < ngroups; i++) {
 655                 if (++*group >= ngroups)
 656                         *group = 0;
 657                 desc = ext4_get_group_desc(sb, *group, NULL);
 658                 if (desc && ext4_free_inodes_count(sb, desc))
 659                         return 0;
 660         }
 661
 662         return -1;
 663 }
 664
 665 /*
 666  * In no journal mode, if an inode has recently been deleted, we want
 667  * to avoid reusing it until we're reasonably sure the inode table
 668  * block has been written back to disk.  (Yes, these values are
 669  * somewhat arbitrary...)
 670  */
 671 #define RECENTCY_MIN    60
 672 #define RECENTCY_DIRTY  300
 673
 674 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 675 {
 676         struct ext4_group_desc  *gdp;
 677         struct ext4_inode       *raw_inode;
 678         struct buffer_head      *bh;
 679         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 680         int offset, ret = 0;
 681         int recentcy = RECENTCY_MIN;
 682         u32 dtime, now;
 683
 684         gdp = ext4_get_group_desc(sb, group, NULL);
 685         if (unlikely(!gdp))
 686                 return 0;
 687
 688         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 689                        (ino / inodes_per_block));
 690         if (!bh || !buffer_uptodate(bh))
 691                 /*
 692                  * If the block is not in the buffer cache, then it
 693                  * must have been written out.
 694                  */
 695                 goto out;
 696
 697         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 698         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 699
 700         /* i_dtime is only 32 bits on disk, but we only care about relative
 701          * times in the range of a few minutes (i.e. long enough to sync a
 702          * recently-deleted inode to disk), so using the low 32 bits of the
 703          * clock (a 68 year range) is enough, see time_before32() */
 704         dtime = le32_to_cpu(raw_inode->i_dtime);
 705         now = ktime_get_real_seconds();
 706         if (buffer_dirty(bh))
 707                 recentcy += RECENTCY_DIRTY;
 708
 709         if (dtime && time_before32(dtime, now) &&
 710             time_before32(now, dtime + recentcy))
 711                 ret = 1;
 712 out:
 713         brelse(bh);
 714         return ret;
 715 }
 716
 717 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 718                           struct buffer_head *bitmap, unsigned long *ino)
 719 {
 720         bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
 721         unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
 722
 723 next:
 724         *ino = ext4_find_next_zero_bit((unsigned long *)
 725                                        bitmap->b_data,
 726                                        EXT4_INODES_PER_GROUP(sb), *ino);
 727         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 728                 goto not_found;
 729
 730         if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
 731                 recently_deleted_ino = *ino;
 732                 *ino = *ino + 1;
 733                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 734                         goto next;
 735                 goto not_found;
 736         }
 737         return 1;
 738 not_found:
 739         if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
 740                 return 0;
 741         /*
 742          * Not reusing recently deleted inodes is mostly a preference. We don't
 743          * want to report ENOSPC or skew allocation patterns because of that.
 744          * So return even recently deleted inode if we could find better in the
 745          * given range.
 746          */
 747         *ino = recently_deleted_ino;
 748         return 1;
 749 }
 750
 751 int ext4_mark_inode_used(struct super_block *sb, int ino)
 752 {
 753         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 754         struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;
 755         struct ext4_group_desc *gdp;
 756         ext4_group_t group;
 757         int bit;
 758         int err;
 759
 760         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
 761                 return -EFSCORRUPTED;
 762
 763         group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 764         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 765         inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 766         if (IS_ERR(inode_bitmap_bh))
 767                 return PTR_ERR(inode_bitmap_bh);
 768
 769         if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {
 770                 err = 0;
 771                 goto out;
 772         }
 773
 774         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 775         if (!gdp) {
 776                 err = -EINVAL;
 777                 goto out;
 778         }
 779
 780         ext4_set_bit(bit, inode_bitmap_bh->b_data);
 781
 782         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 783         err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);
 784         if (err) {
 785                 ext4_std_error(sb, err);
 786                 goto out;
 787         }
 788         err = sync_dirty_buffer(inode_bitmap_bh);
 789         if (err) {
 790                 ext4_std_error(sb, err);
 791                 goto out;
 792         }
 793
 794         /* We may have to initialize the block bitmap if it isn't already */
 795         if (ext4_has_group_desc_csum(sb) &&
 796             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 797                 struct buffer_head *block_bitmap_bh;
 798
 799                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
 800                 if (IS_ERR(block_bitmap_bh)) {
 801                         err = PTR_ERR(block_bitmap_bh);
 802                         goto out;
 803                 }
 804
 805                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
 806                 err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);
 807                 sync_dirty_buffer(block_bitmap_bh);
 808
 809                 /* recheck and clear flag under lock if we still need to */
 810                 ext4_lock_group(sb, group);
 811                 if (ext4_has_group_desc_csum(sb) &&
 812                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
 813                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 814                         ext4_free_group_clusters_set(sb, gdp,
 815                                 ext4_free_clusters_after_init(sb, group, gdp));
 816                         ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
 817                         ext4_group_desc_csum_set(sb, group, gdp);
 818                 }
 819                 ext4_unlock_group(sb, group);
 820                 brelse(block_bitmap_bh);
 821
 822                 if (err) {
 823                         ext4_std_error(sb, err);
 824                         goto out;
 825                 }
 826         }
 827
 828         /* Update the relevant bg descriptor fields */
 829         if (ext4_has_group_desc_csum(sb)) {
 830                 int free;
 831
 832                 ext4_lock_group(sb, group); /* while we modify the bg desc */
 833                 free = EXT4_INODES_PER_GROUP(sb) -
 834                         ext4_itable_unused_count(sb, gdp);
 835                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 836                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
 837                         free = 0;
 838                 }
 839
 840                 /*
 841                  * Check the relative inode number against the last used
 842                  * relative inode number in this group. if it is greater
 843                  * we need to update the bg_itable_unused count
 844                  */
 845                 if (bit >= free)
 846                         ext4_itable_unused_set(sb, gdp,
 847                                         (EXT4_INODES_PER_GROUP(sb) - bit - 1));
 848         } else {
 849                 ext4_lock_group(sb, group);
 850         }
 851
 852         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
 853         if (ext4_has_group_desc_csum(sb)) {
 854                 ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
 855                 ext4_group_desc_csum_set(sb, group, gdp);
 856         }
 857
 858         ext4_unlock_group(sb, group);
 859         err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
 860         sync_dirty_buffer(group_desc_bh);
 861 out:
 862         brelse(inode_bitmap_bh);
 863         return err;
 864 }
 865
 866 static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
 867                                             bool encrypt)
 868 {
 869         struct super_block *sb = dir->i_sb;
 870         int nblocks = 0;
 871 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 872         struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);
 873
 874         if (IS_ERR(p))
 875                 return PTR_ERR(p);
 876         if (p) {
 877                 int acl_size = p->a_count * sizeof(ext4_acl_entry);
 878
 879                 nblocks += (S_ISDIR(mode) ? 2 : 1) *
 880                         __ext4_xattr_set_credits(sb, NULL /* inode */,
 881                                                  NULL /* block_bh */, acl_size,
 882                                                  true /* is_create */);
 883                 posix_acl_release(p);
 884         }
 885 #endif
 886
 887 #ifdef CONFIG_SECURITY
 888         {
 889                 int num_security_xattrs = 1;
 890
 891 #ifdef CONFIG_INTEGRITY
 892                 num_security_xattrs++;
 893 #endif
 894                 /*
 895                  * We assume that security xattrs are never more than 1k.
 896                  * In practice they are under 128 bytes.
 897                  */
 898                 nblocks += num_security_xattrs *
 899                         __ext4_xattr_set_credits(sb, NULL /* inode */,
 900                                                  NULL /* block_bh */, 1024,
 901                                                  true /* is_create */);
 902         }
 903 #endif
 904         if (encrypt)
 905                 nblocks += __ext4_xattr_set_credits(sb,
 906                                                     NULL /* inode */,
 907                                                     NULL /* block_bh */,
 908                                                     FSCRYPT_SET_CONTEXT_MAX_SIZE,
 909                                                     true /* is_create */);
 910         return nblocks;
 911 }
 912
 913 /*
 914  * There are two policies for allocating an inode.  If the new inode is
 915  * a directory, then a forward search is made for a block group with both
 916  * free space and a low directory-to-inode ratio; if that fails, then of
 917  * the groups with above-average free space, that group with the fewest
 918  * directories already is chosen.
 919  *
 920  * For other inodes, search forward from the parent directory's block
 921  * group to find a free inode.
 922  */
 923 struct inode *__ext4_new_inode(struct mnt_idmap *idmap,
 924                                handle_t *handle, struct inode *dir,
 925                                umode_t mode, const struct qstr *qstr,
 926                                __u32 goal, uid_t *owner, __u32 i_flags,
 927                                int handle_type, unsigned int line_no,
 928                                int nblocks)
 929 {
 930         struct super_block *sb;
 931         struct buffer_head *inode_bitmap_bh = NULL;
 932         struct buffer_head *group_desc_bh;
 933         ext4_group_t ngroups, group = 0;
 934         unsigned long ino = 0;
 935         struct inode *inode;
 936         struct ext4_group_desc *gdp = NULL;
 937         struct ext4_inode_info *ei;
 938         struct ext4_sb_info *sbi;
 939         int ret2, err;
 940         struct inode *ret;
 941         ext4_group_t i;
 942         ext4_group_t flex_group;
 943         struct ext4_group_info *grp = NULL;
 944         bool encrypt = false;
 945
 946         /* Cannot create files in a deleted directory */
 947         if (!dir || !dir->i_nlink)
 948                 return ERR_PTR(-EPERM);
 949
 950         sb = dir->i_sb;
 951         sbi = EXT4_SB(sb);
 952
 953         if (unlikely(ext4_forced_shutdown(sb)))
 954                 return ERR_PTR(-EIO);
 955
 956         ngroups = ext4_get_groups_count(sb);
 957         trace_ext4_request_inode(dir, mode);
 958         inode = new_inode(sb);
 959         if (!inode)
 960                 return ERR_PTR(-ENOMEM);
 961         ei = EXT4_I(inode);
 962
 963         /*
 964          * Initialize owners and quota early so that we don't have to account
 965          * for quota initialization worst case in standard inode creating
 966          * transaction
 967          */
 968         if (owner) {
 969                 inode->i_mode = mode;
 970                 i_uid_write(inode, owner[0]);
 971                 i_gid_write(inode, owner[1]);
 972         } else if (test_opt(sb, GRPID)) {
 973                 inode->i_mode = mode;
 974                 inode_fsuid_set(inode, idmap);
 975                 inode->i_gid = dir->i_gid;
 976         } else
 977                 inode_init_owner(idmap, inode, dir, mode);
 978
 979         if (ext4_has_feature_project(sb) &&
 980             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 981                 ei->i_projid = EXT4_I(dir)->i_projid;
 982         else
 983                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 984
 985         if (!(i_flags & EXT4_EA_INODE_FL)) {
 986                 err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
 987                 if (err)
 988                         goto out;
 989         }
 990
 991         err = dquot_initialize(inode);
 992         if (err)
 993                 goto out;
 994
 995         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 996                 ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
 997                 if (ret2 < 0) {
 998                         err = ret2;
 999                         goto out;
1000                 }
1001                 nblocks += ret2;
1002         }
1003
1004         if (!goal)
1005                 goal = sbi->s_inode_goal;
1006
1007         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
1008                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
1009                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
1010                 ret2 = 0;
1011                 goto got_group;
1012         }
1013
1014         if (S_ISDIR(mode))
1015                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
1016         else
1017                 ret2 = find_group_other(sb, dir, &group, mode);
1018
1019 got_group:
1020         EXT4_I(dir)->i_last_alloc_group = group;
1021         err = -ENOSPC;
1022         if (ret2 == -1)
1023                 goto out;
1024
1025         /*
1026          * Normally we will only go through one pass of this loop,
1027          * unless we get unlucky and it turns out the group we selected
1028          * had its last inode grabbed by someone else.
1029          */
1030         for (i = 0; i < ngroups; i++, ino = 0) {
1031                 err = -EIO;
1032
1033                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1034                 if (!gdp)
1035                         goto out;
1036
1037                 /*
1038                  * Check free inodes count before loading bitmap.
1039                  */
1040                 if (ext4_free_inodes_count(sb, gdp) == 0)
1041                         goto next_group;
1042
1043                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1044                         grp = ext4_get_group_info(sb, group);
1045                         /*
1046                          * Skip groups with already-known suspicious inode
1047                          * tables
1048                          */
1049                         if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1050                                 goto next_group;
1051                 }
1052
1053                 brelse(inode_bitmap_bh);
1054                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
1055                 /* Skip groups with suspicious inode tables */
1056                 if (IS_ERR(inode_bitmap_bh)) {
1057                         inode_bitmap_bh = NULL;
1058                         goto next_group;
1059                 }
1060                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY) &&
1061                     EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1062                         goto next_group;
1063
1064                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1065                 if (!ret2)
1066                         goto next_group;
1067
1068                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
1069                         ext4_error(sb, "reserved inode found cleared - "
1070                                    "inode=%lu", ino + 1);
1071                         ext4_mark_group_bitmap_corrupted(sb, group,
1072                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1073                         goto next_group;
1074                 }
1075
1076                 if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
1077                         BUG_ON(nblocks <= 0);
1078                         handle = __ext4_journal_start_sb(NULL, dir->i_sb,
1079                                  line_no, handle_type, nblocks, 0,
1080                                  ext4_trans_default_revoke_credits(sb));
1081                         if (IS_ERR(handle)) {
1082                                 err = PTR_ERR(handle);
1083                                 ext4_std_error(sb, err);
1084                                 goto out;
1085                         }
1086                 }
1087                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
1088                 err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
1089                                                     EXT4_JTR_NONE);
1090                 if (err) {
1091                         ext4_std_error(sb, err);
1092                         goto out;
1093                 }
1094                 ext4_lock_group(sb, group);
1095                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
1096                 if (ret2) {
1097                         /* Someone already took the bit. Repeat the search
1098                          * with lock held.
1099                          */
1100                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1101                         if (ret2) {
1102                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
1103                                 ret2 = 0;
1104                         } else {
1105                                 ret2 = 1; /* we didn't grab the inode */
1106                         }
1107                 }
1108                 ext4_unlock_group(sb, group);
1109                 ino++;          /* the inode bitmap is zero-based */
1110                 if (!ret2)
1111                         goto got; /* we grabbed the inode! */
1112
1113 next_group:
1114                 if (++group == ngroups)
1115                         group = 0;
1116         }
1117         err = -ENOSPC;
1118         goto out;
1119
1120 got:
1121         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1122         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1123         if (err) {
1124                 ext4_std_error(sb, err);
1125                 goto out;
1126         }
1127
1128         BUFFER_TRACE(group_desc_bh, "get_write_access");
1129         err = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1130                                             EXT4_JTR_NONE);
1131         if (err) {
1132                 ext4_std_error(sb, err);
1133                 goto out;
1134         }
1135
1136         /* We may have to initialize the block bitmap if it isn't already */
1137         if (ext4_has_group_desc_csum(sb) &&
1138             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1139                 struct buffer_head *block_bitmap_bh;
1140
1141                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1142                 if (IS_ERR(block_bitmap_bh)) {
1143                         err = PTR_ERR(block_bitmap_bh);
1144                         goto out;
1145                 }
1146                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1147                 err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,
1148                                                     EXT4_JTR_NONE);
1149                 if (err) {
1150                         brelse(block_bitmap_bh);
1151                         ext4_std_error(sb, err);
1152                         goto out;
1153                 }
1154
1155                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1156                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1157
1158                 /* recheck and clear flag under lock if we still need to */
1159                 ext4_lock_group(sb, group);
1160                 if (ext4_has_group_desc_csum(sb) &&
1161                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1162                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1163                         ext4_free_group_clusters_set(sb, gdp,
1164                                 ext4_free_clusters_after_init(sb, group, gdp));
1165                         ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
1166                         ext4_group_desc_csum_set(sb, group, gdp);
1167                 }
1168                 ext4_unlock_group(sb, group);
1169                 brelse(block_bitmap_bh);
1170
1171                 if (err) {
1172                         ext4_std_error(sb, err);
1173                         goto out;
1174                 }
1175         }
1176
1177         /* Update the relevant bg descriptor fields */
1178         if (ext4_has_group_desc_csum(sb)) {
1179                 int free;
1180                 struct ext4_group_info *grp = NULL;
1181
1182                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1183                         grp = ext4_get_group_info(sb, group);
1184                         if (!grp) {
1185                                 err = -EFSCORRUPTED;
1186                                 goto out;
1187                         }
1188                         down_read(&grp->alloc_sem); /*
1189                                                      * protect vs itable
1190                                                      * lazyinit
1191                                                      */
1192                 }
1193                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1194                 free = EXT4_INODES_PER_GROUP(sb) -
1195                         ext4_itable_unused_count(sb, gdp);
1196                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1197                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1198                         free = 0;
1199                 }
1200                 /*
1201                  * Check the relative inode number against the last used
1202                  * relative inode number in this group. if it is greater
1203                  * we need to update the bg_itable_unused count
1204                  */
1205                 if (ino > free)
1206                         ext4_itable_unused_set(sb, gdp,
1207                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1208                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1209                         up_read(&grp->alloc_sem);
1210         } else {
1211                 ext4_lock_group(sb, group);
1212         }
1213
1214         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1215         if (S_ISDIR(mode)) {
1216                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1217                 if (sbi->s_log_groups_per_flex) {
1218                         ext4_group_t f = ext4_flex_group(sbi, group);
1219
1220                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1221                                                         f)->used_dirs);
1222                 }
1223         }
1224         if (ext4_has_group_desc_csum(sb)) {
1225                 ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
1226                 ext4_group_desc_csum_set(sb, group, gdp);
1227         }
1228         ext4_unlock_group(sb, group);
1229
1230         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1231         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1232         if (err) {
1233                 ext4_std_error(sb, err);
1234                 goto out;
1235         }
1236
1237         percpu_counter_dec(&sbi->s_freeinodes_counter);
1238         if (S_ISDIR(mode))
1239                 percpu_counter_inc(&sbi->s_dirs_counter);
1240
1241         if (sbi->s_log_groups_per_flex) {
1242                 flex_group = ext4_flex_group(sbi, group);
1243                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1244                                                 flex_group)->free_inodes);
1245         }
1246
1247         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1248         /* This is the optimal IO size (for stat), not the fs block size */
1249         inode->i_blocks = 0;
1250         simple_inode_init_ts(inode);
1251         ei->i_crtime = inode_get_mtime(inode);
1252
1253         memset(ei->i_data, 0, sizeof(ei->i_data));
1254         ei->i_dir_start_lookup = 0;
1255         ei->i_disksize = 0;
1256
1257         /* Don't inherit extent flag from directory, amongst others. */
1258         ei->i_flags =
1259                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1260         ei->i_flags |= i_flags;
1261         ei->i_file_acl = 0;
1262         ei->i_dtime = 0;
1263         ei->i_block_group = group;
1264         ei->i_last_alloc_group = ~0;
1265
1266         ext4_set_inode_flags(inode, true);
1267         if (IS_DIRSYNC(inode))
1268                 ext4_handle_sync(handle);
1269         if (insert_inode_locked(inode) < 0) {
1270                 /*
1271                  * Likely a bitmap corruption causing inode to be allocated
1272                  * twice.
1273                  */
1274                 err = -EIO;
1275                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1276                            inode->i_ino);
1277                 ext4_mark_group_bitmap_corrupted(sb, group,
1278                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1279                 goto out;
1280         }
1281         inode->i_generation = get_random_u32();
1282
1283         /* Precompute checksum seed for inode metadata */
1284         if (ext4_has_metadata_csum(sb)) {
1285                 __u32 csum;
1286                 __le32 inum = cpu_to_le32(inode->i_ino);
1287                 __le32 gen = cpu_to_le32(inode->i_generation);
1288                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1289                                    sizeof(inum));
1290                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1291                                               sizeof(gen));
1292         }
1293
1294         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1295         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1296
1297         ei->i_extra_isize = sbi->s_want_extra_isize;
1298         ei->i_inline_off = 0;
1299         if (ext4_has_feature_inline_data(sb) &&
1300             (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1301                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1302         ret = inode;
1303         err = dquot_alloc_inode(inode);
1304         if (err)
1305                 goto fail_drop;
1306
1307         /*
1308          * Since the encryption xattr will always be unique, create it first so
1309          * that it's less likely to end up in an external xattr block and
1310          * prevent its deduplication.
1311          */
1312         if (encrypt) {
1313                 err = fscrypt_set_context(inode, handle);
1314                 if (err)
1315                         goto fail_free_drop;
1316         }
1317
1318         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1319                 err = ext4_init_acl(handle, inode, dir);
1320                 if (err)
1321                         goto fail_free_drop;
1322
1323                 err = ext4_init_security(handle, inode, dir, qstr);
1324                 if (err)
1325                         goto fail_free_drop;
1326         }
1327
1328         if (ext4_has_feature_extents(sb)) {
1329                 /* set extent flag only for directory, file and normal symlink*/
1330                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1331                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1332                         ext4_ext_tree_init(handle, inode);
1333                 }
1334         }
1335
1336         ext4_update_inode_fsync_trans(handle, inode, 1);
1337
1338         err = ext4_mark_inode_dirty(handle, inode);
1339         if (err) {
1340                 ext4_std_error(sb, err);
1341                 goto fail_free_drop;
1342         }
1343
1344         ext4_debug("allocating inode %lu\n", inode->i_ino);
1345         trace_ext4_allocate_inode(inode, dir, mode);
1346         brelse(inode_bitmap_bh);
1347         return ret;
1348
1349 fail_free_drop:
1350         dquot_free_inode(inode);
1351 fail_drop:
1352         clear_nlink(inode);
1353         unlock_new_inode(inode);
1354 out:
1355         dquot_drop(inode);
1356         inode->i_flags |= S_NOQUOTA;
1357         iput(inode);
1358         brelse(inode_bitmap_bh);
1359         return ERR_PTR(err);
1360 }
1361
1362 /* Verify that we are loading a valid orphan from disk */
1363 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1364 {
1365         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1366         ext4_group_t block_group;
1367         int bit;
1368         struct buffer_head *bitmap_bh = NULL;
1369         struct inode *inode = NULL;
1370         int err = -EFSCORRUPTED;
1371
1372         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1373                 goto bad_orphan;
1374
1375         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1376         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1377         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1378         if (IS_ERR(bitmap_bh))
1379                 return ERR_CAST(bitmap_bh);
1380
1381         /* Having the inode bit set should be a 100% indicator that this
1382          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1383          * inodes that were being truncated, so we can't check i_nlink==0.
1384          */
1385         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1386                 goto bad_orphan;
1387
1388         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1389         if (IS_ERR(inode)) {
1390                 err = PTR_ERR(inode);
1391                 ext4_error_err(sb, -err,
1392                                "couldn't read orphan inode %lu (err %d)",
1393                                ino, err);
1394                 brelse(bitmap_bh);
1395                 return inode;
1396         }
1397
1398         /*
1399          * If the orphans has i_nlinks > 0 then it should be able to
1400          * be truncated, otherwise it won't be removed from the orphan
1401          * list during processing and an infinite loop will result.
1402          * Similarly, it must not be a bad inode.
1403          */
1404         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1405             is_bad_inode(inode))
1406                 goto bad_orphan;
1407
1408         if (NEXT_ORPHAN(inode) > max_ino)
1409                 goto bad_orphan;
1410         brelse(bitmap_bh);
1411         return inode;
1412
1413 bad_orphan:
1414         ext4_error(sb, "bad orphan inode %lu", ino);
1415         if (bitmap_bh)
1416                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1417                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1418                        ext4_test_bit(bit, bitmap_bh->b_data));
1419         if (inode) {
1420                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1421                        is_bad_inode(inode));
1422                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1423                        NEXT_ORPHAN(inode));
1424                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1425                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1426                 /* Avoid freeing blocks if we got a bad deleted inode */
1427                 if (inode->i_nlink == 0)
1428                         inode->i_blocks = 0;
1429                 iput(inode);
1430         }
1431         brelse(bitmap_bh);
1432         return ERR_PTR(err);
1433 }
1434
1435 unsigned long ext4_count_free_inodes(struct super_block *sb)
1436 {
1437         unsigned long desc_count;
1438         struct ext4_group_desc *gdp;
1439         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1440 #ifdef EXT4FS_DEBUG
1441         struct ext4_super_block *es;
1442         unsigned long bitmap_count, x;
1443         struct buffer_head *bitmap_bh = NULL;
1444
1445         es = EXT4_SB(sb)->s_es;
1446         desc_count = 0;
1447         bitmap_count = 0;
1448         gdp = NULL;
1449         for (i = 0; i < ngroups; i++) {
1450                 gdp = ext4_get_group_desc(sb, i, NULL);
1451                 if (!gdp)
1452                         continue;
1453                 desc_count += ext4_free_inodes_count(sb, gdp);
1454                 brelse(bitmap_bh);
1455                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1456                 if (IS_ERR(bitmap_bh)) {
1457                         bitmap_bh = NULL;
1458                         continue;
1459                 }
1460
1461                 x = ext4_count_free(bitmap_bh->b_data,
1462                                     EXT4_INODES_PER_GROUP(sb) / 8);
1463                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1464                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1465                 bitmap_count += x;
1466         }
1467         brelse(bitmap_bh);
1468         printk(KERN_DEBUG "ext4_count_free_inodes: "
1469                "stored = %u, computed = %lu, %lu\n",
1470                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1471         return desc_count;
1472 #else
1473         desc_count = 0;
1474         for (i = 0; i < ngroups; i++) {
1475                 gdp = ext4_get_group_desc(sb, i, NULL);
1476                 if (!gdp)
1477                         continue;
1478                 desc_count += ext4_free_inodes_count(sb, gdp);
1479                 cond_resched();
1480         }
1481         return desc_count;
1482 #endif
1483 }
1484
1485 /* Called at mount-time, super-block is locked */
1486 unsigned long ext4_count_dirs(struct super_block * sb)
1487 {
1488         unsigned long count = 0;
1489         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1490
1491         for (i = 0; i < ngroups; i++) {
1492                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1493                 if (!gdp)
1494                         continue;
1495                 count += ext4_used_dirs_count(sb, gdp);
1496         }
1497         return count;
1498 }
1499
1500 /*
1501  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1502  * inode table. Must be called without any spinlock held. The only place
1503  * where it is called from on active part of filesystem is ext4lazyinit
1504  * thread, so we do not need any special locks, however we have to prevent
1505  * inode allocation from the current group, so we take alloc_sem lock, to
1506  * block ext4_new_inode() until we are finished.
1507  */
1508 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1509                                  int barrier)
1510 {
1511         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1512         struct ext4_sb_info *sbi = EXT4_SB(sb);
1513         struct ext4_group_desc *gdp = NULL;
1514         struct buffer_head *group_desc_bh;
1515         handle_t *handle;
1516         ext4_fsblk_t blk;
1517         int num, ret = 0, used_blks = 0;
1518         unsigned long used_inos = 0;
1519
1520         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1521         if (!gdp || !grp)
1522                 goto out;
1523
1524         /*
1525          * We do not need to lock this, because we are the only one
1526          * handling this flag.
1527          */
1528         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1529                 goto out;
1530
1531         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1532         if (IS_ERR(handle)) {
1533                 ret = PTR_ERR(handle);
1534                 goto out;
1535         }
1536
1537         down_write(&grp->alloc_sem);
1538         /*
1539          * If inode bitmap was already initialized there may be some
1540          * used inodes so we need to skip blocks with used inodes in
1541          * inode table.
1542          */
1543         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1544                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1545                             ext4_itable_unused_count(sb, gdp);
1546                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1547
1548                 /* Bogus inode unused count? */
1549                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1550                         ext4_error(sb, "Something is wrong with group %u: "
1551                                    "used itable blocks: %d; "
1552                                    "itable unused count: %u",
1553                                    group, used_blks,
1554                                    ext4_itable_unused_count(sb, gdp));
1555                         ret = 1;
1556                         goto err_out;
1557                 }
1558
1559                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1560                 /*
1561                  * Are there some uninitialized inodes in the inode table
1562                  * before the first normal inode?
1563                  */
1564                 if ((used_blks != sbi->s_itb_per_group) &&
1565                      (used_inos < EXT4_FIRST_INO(sb))) {
1566                         ext4_error(sb, "Something is wrong with group %u: "
1567                                    "itable unused count: %u; "
1568                                    "itables initialized count: %ld",
1569                                    group, ext4_itable_unused_count(sb, gdp),
1570                                    used_inos);
1571                         ret = 1;
1572                         goto err_out;
1573                 }
1574         }
1575
1576         blk = ext4_inode_table(sb, gdp) + used_blks;
1577         num = sbi->s_itb_per_group - used_blks;
1578
1579         BUFFER_TRACE(group_desc_bh, "get_write_access");
1580         ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1581                                             EXT4_JTR_NONE);
1582         if (ret)
1583                 goto err_out;
1584
1585         /*
1586          * Skip zeroout if the inode table is full. But we set the ZEROED
1587          * flag anyway, because obviously, when it is full it does not need
1588          * further zeroing.
1589          */
1590         if (unlikely(num == 0))
1591                 goto skip_zeroout;
1592
1593         ext4_debug("going to zero out inode table in group %d\n",
1594                    group);
1595         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1596         if (ret < 0)
1597                 goto err_out;
1598         if (barrier)
1599                 blkdev_issue_flush(sb->s_bdev);
1600
1601 skip_zeroout:
1602         ext4_lock_group(sb, group);
1603         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1604         ext4_group_desc_csum_set(sb, group, gdp);
1605         ext4_unlock_group(sb, group);
1606
1607         BUFFER_TRACE(group_desc_bh,
1608                      "call ext4_handle_dirty_metadata");
1609         ret = ext4_handle_dirty_metadata(handle, NULL,
1610                                          group_desc_bh);
1611
1612 err_out:
1613         up_write(&grp->alloc_sem);
1614         ext4_journal_stop(handle);
1615 out:
1616         return ret;
1617 }