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;
  86
  87         if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
  88                 return 0;
  89
  90         grp = ext4_get_group_info(sb, block_group);
  91
  92         if (buffer_verified(bh))
  93                 return 0;
  94         if (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, block_group, desc, bh,
 102                                            EXT4_INODES_PER_GROUP(sb) / 8) ||
 103             ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
 104                 ext4_unlock_group(sb, block_group);
 105                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 106                            "inode_bitmap = %llu", block_group, blk);
 107                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 108                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 109                 return -EFSBADCRC;
 110         }
 111         set_buffer_verified(bh);
 112 verified:
 113         ext4_unlock_group(sb, block_group);
 114         return 0;
 115 }
 116
 117 /*
 118  * Read the inode allocation bitmap for a given block_group, reading
 119  * into the specified slot in the superblock's bitmap cache.
 120  *
 121  * Return buffer_head of bitmap on success, or an ERR_PTR on error.
 122  */
 123 static struct buffer_head *
 124 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 125 {
 126         struct ext4_group_desc *desc;
 127         struct ext4_sb_info *sbi = EXT4_SB(sb);
 128         struct buffer_head *bh = NULL;
 129         ext4_fsblk_t bitmap_blk;
 130         int err;
 131
 132         desc = ext4_get_group_desc(sb, block_group, NULL);
 133         if (!desc)
 134                 return ERR_PTR(-EFSCORRUPTED);
 135
 136         bitmap_blk = ext4_inode_bitmap(sb, desc);
 137         if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
 138             (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
 139                 ext4_error(sb, "Invalid inode bitmap blk %llu in "
 140                            "block_group %u", bitmap_blk, block_group);
 141                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 142                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 143                 return ERR_PTR(-EFSCORRUPTED);
 144         }
 145         bh = sb_getblk(sb, bitmap_blk);
 146         if (unlikely(!bh)) {
 147                 ext4_warning(sb, "Cannot read inode bitmap - "
 148                              "block_group = %u, inode_bitmap = %llu",
 149                              block_group, bitmap_blk);
 150                 return ERR_PTR(-ENOMEM);
 151         }
 152         if (bitmap_uptodate(bh))
 153                 goto verify;
 154
 155         lock_buffer(bh);
 156         if (bitmap_uptodate(bh)) {
 157                 unlock_buffer(bh);
 158                 goto verify;
 159         }
 160
 161         ext4_lock_group(sb, block_group);
 162         if (ext4_has_group_desc_csum(sb) &&
 163             (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
 164                 if (block_group == 0) {
 165                         ext4_unlock_group(sb, block_group);
 166                         unlock_buffer(bh);
 167                         ext4_error(sb, "Inode bitmap for bg 0 marked "
 168                                    "uninitialized");
 169                         err = -EFSCORRUPTED;
 170                         goto out;
 171                 }
 172                 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 173                 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
 174                                      sb->s_blocksize * 8, bh->b_data);
 175                 set_bitmap_uptodate(bh);
 176                 set_buffer_uptodate(bh);
 177                 set_buffer_verified(bh);
 178                 ext4_unlock_group(sb, block_group);
 179                 unlock_buffer(bh);
 180                 return bh;
 181         }
 182         ext4_unlock_group(sb, block_group);
 183
 184         if (buffer_uptodate(bh)) {
 185                 /*
 186                  * if not uninit if bh is uptodate,
 187                  * bitmap is also uptodate
 188                  */
 189                 set_bitmap_uptodate(bh);
 190                 unlock_buffer(bh);
 191                 goto verify;
 192         }
 193         /*
 194          * submit the buffer_head for reading
 195          */
 196         trace_ext4_load_inode_bitmap(sb, block_group);
 197         ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
 198         ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
 199         if (!buffer_uptodate(bh)) {
 200                 put_bh(bh);
 201                 ext4_error_err(sb, EIO, "Cannot read inode bitmap - "
 202                                "block_group = %u, inode_bitmap = %llu",
 203                                block_group, bitmap_blk);
 204                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 205                                 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 206                 return ERR_PTR(-EIO);
 207         }
 208
 209 verify:
 210         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 211         if (err)
 212                 goto out;
 213         return bh;
 214 out:
 215         put_bh(bh);
 216         return ERR_PTR(err);
 217 }
 218
 219 /*
 220  * NOTE! When we get the inode, we're the only people
 221  * that have access to it, and as such there are no
 222  * race conditions we have to worry about. The inode
 223  * is not on the hash-lists, and it cannot be reached
 224  * through the filesystem because the directory entry
 225  * has been deleted earlier.
 226  *
 227  * HOWEVER: we must make sure that we get no aliases,
 228  * which means that we have to call "clear_inode()"
 229  * _before_ we mark the inode not in use in the inode
 230  * bitmaps. Otherwise a newly created file might use
 231  * the same inode number (not actually the same pointer
 232  * though), and then we'd have two inodes sharing the
 233  * same inode number and space on the harddisk.
 234  */
 235 void ext4_free_inode(handle_t *handle, struct inode *inode)
 236 {
 237         struct super_block *sb = inode->i_sb;
 238         int is_directory;
 239         unsigned long ino;
 240         struct buffer_head *bitmap_bh = NULL;
 241         struct buffer_head *bh2;
 242         ext4_group_t block_group;
 243         unsigned long bit;
 244         struct ext4_group_desc *gdp;
 245         struct ext4_super_block *es;
 246         struct ext4_sb_info *sbi;
 247         int fatal = 0, err, count, cleared;
 248         struct ext4_group_info *grp;
 249
 250         if (!sb) {
 251                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 252                        "nonexistent device\n", __func__, __LINE__);
 253                 return;
 254         }
 255         if (atomic_read(&inode->i_count) > 1) {
 256                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 257                          __func__, __LINE__, inode->i_ino,
 258                          atomic_read(&inode->i_count));
 259                 return;
 260         }
 261         if (inode->i_nlink) {
 262                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 263                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 264                 return;
 265         }
 266         sbi = EXT4_SB(sb);
 267
 268         ino = inode->i_ino;
 269         ext4_debug("freeing inode %lu\n", ino);
 270         trace_ext4_free_inode(inode);
 271
 272         dquot_initialize(inode);
 273         dquot_free_inode(inode);
 274
 275         is_directory = S_ISDIR(inode->i_mode);
 276
 277         /* Do this BEFORE marking the inode not in use or returning an error */
 278         ext4_clear_inode(inode);
 279
 280         es = sbi->s_es;
 281         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 282                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 283                 goto error_return;
 284         }
 285         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 286         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 287         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 288         /* Don't bother if the inode bitmap is corrupt. */
 289         if (IS_ERR(bitmap_bh)) {
 290                 fatal = PTR_ERR(bitmap_bh);
 291                 bitmap_bh = NULL;
 292                 goto error_return;
 293         }
 294         if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
 295                 grp = ext4_get_group_info(sb, block_group);
 296                 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 297                         fatal = -EFSCORRUPTED;
 298                         goto error_return;
 299                 }
 300         }
 301
 302         BUFFER_TRACE(bitmap_bh, "get_write_access");
 303         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 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, bh2);
 312         }
 313         ext4_lock_group(sb, block_group);
 314         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 315         if (fatal || !cleared) {
 316                 ext4_unlock_group(sb, block_group);
 317                 goto out;
 318         }
 319
 320         count = ext4_free_inodes_count(sb, gdp) + 1;
 321         ext4_free_inodes_set(sb, gdp, count);
 322         if (is_directory) {
 323                 count = ext4_used_dirs_count(sb, gdp) - 1;
 324                 ext4_used_dirs_set(sb, gdp, count);
 325                 if (percpu_counter_initialized(&sbi->s_dirs_counter))
 326                         percpu_counter_dec(&sbi->s_dirs_counter);
 327         }
 328         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 329                                    EXT4_INODES_PER_GROUP(sb) / 8);
 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                         grp = hinfo.hash;
 465                 } else
 466                         grp = prandom_u32();
 467                 parent_group = (unsigned)grp % ngroups;
 468                 for (i = 0; i < ngroups; i++) {
 469                         g = (parent_group + i) % ngroups;
 470                         get_orlov_stats(sb, g, flex_size, &stats);
 471                         if (!stats.free_inodes)
 472                                 continue;
 473                         if (stats.used_dirs >= best_ndir)
 474                                 continue;
 475                         if (stats.free_inodes < avefreei)
 476                                 continue;
 477                         if (stats.free_clusters < avefreec)
 478                                 continue;
 479                         grp = g;
 480                         ret = 0;
 481                         best_ndir = stats.used_dirs;
 482                 }
 483                 if (ret)
 484                         goto fallback;
 485         found_flex_bg:
 486                 if (flex_size == 1) {
 487                         *group = grp;
 488                         return 0;
 489                 }
 490
 491                 /*
 492                  * We pack inodes at the beginning of the flexgroup's
 493                  * inode tables.  Block allocation decisions will do
 494                  * something similar, although regular files will
 495                  * start at 2nd block group of the flexgroup.  See
 496                  * ext4_ext_find_goal() and ext4_find_near().
 497                  */
 498                 grp *= flex_size;
 499                 for (i = 0; i < flex_size; i++) {
 500                         if (grp+i >= real_ngroups)
 501                                 break;
 502                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 503                         if (desc && ext4_free_inodes_count(sb, desc)) {
 504                                 *group = grp+i;
 505                                 return 0;
 506                         }
 507                 }
 508                 goto fallback;
 509         }
 510
 511         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 512         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 513         if (min_inodes < 1)
 514                 min_inodes = 1;
 515         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 516
 517         /*
 518          * Start looking in the flex group where we last allocated an
 519          * inode for this parent directory
 520          */
 521         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 522                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 523                 if (flex_size > 1)
 524                         parent_group >>= sbi->s_log_groups_per_flex;
 525         }
 526
 527         for (i = 0; i < ngroups; i++) {
 528                 grp = (parent_group + i) % ngroups;
 529                 get_orlov_stats(sb, grp, flex_size, &stats);
 530                 if (stats.used_dirs >= max_dirs)
 531                         continue;
 532                 if (stats.free_inodes < min_inodes)
 533                         continue;
 534                 if (stats.free_clusters < min_clusters)
 535                         continue;
 536                 goto found_flex_bg;
 537         }
 538
 539 fallback:
 540         ngroups = real_ngroups;
 541         avefreei = freei / ngroups;
 542 fallback_retry:
 543         parent_group = EXT4_I(parent)->i_block_group;
 544         for (i = 0; i < ngroups; i++) {
 545                 grp = (parent_group + i) % ngroups;
 546                 desc = ext4_get_group_desc(sb, grp, NULL);
 547                 if (desc) {
 548                         grp_free = ext4_free_inodes_count(sb, desc);
 549                         if (grp_free && grp_free >= avefreei) {
 550                                 *group = grp;
 551                                 return 0;
 552                         }
 553                 }
 554         }
 555
 556         if (avefreei) {
 557                 /*
 558                  * The free-inodes counter is approximate, and for really small
 559                  * filesystems the above test can fail to find any blockgroups
 560                  */
 561                 avefreei = 0;
 562                 goto fallback_retry;
 563         }
 564
 565         return -1;
 566 }
 567
 568 static int find_group_other(struct super_block *sb, struct inode *parent,
 569                             ext4_group_t *group, umode_t mode)
 570 {
 571         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 572         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 573         struct ext4_group_desc *desc;
 574         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 575
 576         /*
 577          * Try to place the inode is the same flex group as its
 578          * parent.  If we can't find space, use the Orlov algorithm to
 579          * find another flex group, and store that information in the
 580          * parent directory's inode information so that use that flex
 581          * group for future allocations.
 582          */
 583         if (flex_size > 1) {
 584                 int retry = 0;
 585
 586         try_again:
 587                 parent_group &= ~(flex_size-1);
 588                 last = parent_group + flex_size;
 589                 if (last > ngroups)
 590                         last = ngroups;
 591                 for  (i = parent_group; i < last; i++) {
 592                         desc = ext4_get_group_desc(sb, i, NULL);
 593                         if (desc && ext4_free_inodes_count(sb, desc)) {
 594                                 *group = i;
 595                                 return 0;
 596                         }
 597                 }
 598                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 599                         retry = 1;
 600                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 601                         goto try_again;
 602                 }
 603                 /*
 604                  * If this didn't work, use the Orlov search algorithm
 605                  * to find a new flex group; we pass in the mode to
 606                  * avoid the topdir algorithms.
 607                  */
 608                 *group = parent_group + flex_size;
 609                 if (*group > ngroups)
 610                         *group = 0;
 611                 return find_group_orlov(sb, parent, group, mode, NULL);
 612         }
 613
 614         /*
 615          * Try to place the inode in its parent directory
 616          */
 617         *group = parent_group;
 618         desc = ext4_get_group_desc(sb, *group, NULL);
 619         if (desc && ext4_free_inodes_count(sb, desc) &&
 620             ext4_free_group_clusters(sb, desc))
 621                 return 0;
 622
 623         /*
 624          * We're going to place this inode in a different blockgroup from its
 625          * parent.  We want to cause files in a common directory to all land in
 626          * the same blockgroup.  But we want files which are in a different
 627          * directory which shares a blockgroup with our parent to land in a
 628          * different blockgroup.
 629          *
 630          * So add our directory's i_ino into the starting point for the hash.
 631          */
 632         *group = (*group + parent->i_ino) % ngroups;
 633
 634         /*
 635          * Use a quadratic hash to find a group with a free inode and some free
 636          * blocks.
 637          */
 638         for (i = 1; i < ngroups; i <<= 1) {
 639                 *group += i;
 640                 if (*group >= ngroups)
 641                         *group -= ngroups;
 642                 desc = ext4_get_group_desc(sb, *group, NULL);
 643                 if (desc && ext4_free_inodes_count(sb, desc) &&
 644                     ext4_free_group_clusters(sb, desc))
 645                         return 0;
 646         }
 647
 648         /*
 649          * That failed: try linear search for a free inode, even if that group
 650          * has no free blocks.
 651          */
 652         *group = parent_group;
 653         for (i = 0; i < ngroups; i++) {
 654                 if (++*group >= ngroups)
 655                         *group = 0;
 656                 desc = ext4_get_group_desc(sb, *group, NULL);
 657                 if (desc && ext4_free_inodes_count(sb, desc))
 658                         return 0;
 659         }
 660
 661         return -1;
 662 }
 663
 664 /*
 665  * In no journal mode, if an inode has recently been deleted, we want
 666  * to avoid reusing it until we're reasonably sure the inode table
 667  * block has been written back to disk.  (Yes, these values are
 668  * somewhat arbitrary...)
 669  */
 670 #define RECENTCY_MIN    60
 671 #define RECENTCY_DIRTY  300
 672
 673 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 674 {
 675         struct ext4_group_desc  *gdp;
 676         struct ext4_inode       *raw_inode;
 677         struct buffer_head      *bh;
 678         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 679         int offset, ret = 0;
 680         int recentcy = RECENTCY_MIN;
 681         u32 dtime, now;
 682
 683         gdp = ext4_get_group_desc(sb, group, NULL);
 684         if (unlikely(!gdp))
 685                 return 0;
 686
 687         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 688                        (ino / inodes_per_block));
 689         if (!bh || !buffer_uptodate(bh))
 690                 /*
 691                  * If the block is not in the buffer cache, then it
 692                  * must have been written out.
 693                  */
 694                 goto out;
 695
 696         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 697         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 698
 699         /* i_dtime is only 32 bits on disk, but we only care about relative
 700          * times in the range of a few minutes (i.e. long enough to sync a
 701          * recently-deleted inode to disk), so using the low 32 bits of the
 702          * clock (a 68 year range) is enough, see time_before32() */
 703         dtime = le32_to_cpu(raw_inode->i_dtime);
 704         now = ktime_get_real_seconds();
 705         if (buffer_dirty(bh))
 706                 recentcy += RECENTCY_DIRTY;
 707
 708         if (dtime && time_before32(dtime, now) &&
 709             time_before32(now, dtime + recentcy))
 710                 ret = 1;
 711 out:
 712         brelse(bh);
 713         return ret;
 714 }
 715
 716 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 717                           struct buffer_head *bitmap, unsigned long *ino)
 718 {
 719         bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
 720         unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
 721
 722 next:
 723         *ino = ext4_find_next_zero_bit((unsigned long *)
 724                                        bitmap->b_data,
 725                                        EXT4_INODES_PER_GROUP(sb), *ino);
 726         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 727                 goto not_found;
 728
 729         if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
 730                 recently_deleted_ino = *ino;
 731                 *ino = *ino + 1;
 732                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 733                         goto next;
 734                 goto not_found;
 735         }
 736         return 1;
 737 not_found:
 738         if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
 739                 return 0;
 740         /*
 741          * Not reusing recently deleted inodes is mostly a preference. We don't
 742          * want to report ENOSPC or skew allocation patterns because of that.
 743          * So return even recently deleted inode if we could find better in the
 744          * given range.
 745          */
 746         *ino = recently_deleted_ino;
 747         return 1;
 748 }
 749
 750 int ext4_mark_inode_used(struct super_block *sb, int ino)
 751 {
 752         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 753         struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;
 754         struct ext4_group_desc *gdp;
 755         ext4_group_t group;
 756         int bit;
 757         int err = -EFSCORRUPTED;
 758
 759         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
 760                 goto out;
 761
 762         group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 763         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 764         inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 765         if (IS_ERR(inode_bitmap_bh))
 766                 return PTR_ERR(inode_bitmap_bh);
 767
 768         if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {
 769                 err = 0;
 770                 goto out;
 771         }
 772
 773         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 774         if (!gdp || !group_desc_bh) {
 775                 err = -EINVAL;
 776                 goto out;
 777         }
 778
 779         ext4_set_bit(bit, inode_bitmap_bh->b_data);
 780
 781         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 782         err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);
 783         if (err) {
 784                 ext4_std_error(sb, err);
 785                 goto out;
 786         }
 787         err = sync_dirty_buffer(inode_bitmap_bh);
 788         if (err) {
 789                 ext4_std_error(sb, err);
 790                 goto out;
 791         }
 792
 793         /* We may have to initialize the block bitmap if it isn't already */
 794         if (ext4_has_group_desc_csum(sb) &&
 795             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 796                 struct buffer_head *block_bitmap_bh;
 797
 798                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
 799                 if (IS_ERR(block_bitmap_bh)) {
 800                         err = PTR_ERR(block_bitmap_bh);
 801                         goto out;
 802                 }
 803
 804                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
 805                 err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);
 806                 sync_dirty_buffer(block_bitmap_bh);
 807
 808                 /* recheck and clear flag under lock if we still need to */
 809                 ext4_lock_group(sb, group);
 810                 if (ext4_has_group_desc_csum(sb) &&
 811                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
 812                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
 813                         ext4_free_group_clusters_set(sb, gdp,
 814                                 ext4_free_clusters_after_init(sb, group, gdp));
 815                         ext4_block_bitmap_csum_set(sb, group, gdp,
 816                                                    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, group, gdp, inode_bitmap_bh,
 855                                            EXT4_INODES_PER_GROUP(sb) / 8);
 856                 ext4_group_desc_csum_set(sb, group, gdp);
 857         }
 858
 859         ext4_unlock_group(sb, group);
 860         err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
 861         sync_dirty_buffer(group_desc_bh);
 862 out:
 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_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 user_namespace *mnt_userns,
 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(sbi)))
 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, mnt_userns);
 975                 inode->i_gid = dir->i_gid;
 976         } else
 977                 inode_init_owner(mnt_userns, 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 (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 (((!(sbi->s_mount_state & EXT4_FC_REPLAY))
1057                      && EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) ||
1058                     IS_ERR(inode_bitmap_bh)) {
1059                         inode_bitmap_bh = NULL;
1060                         goto next_group;
1061                 }
1062
1063 repeat_in_this_group:
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(dir->i_sb, line_no,
1079                                  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, inode_bitmap_bh);
1089                 if (err) {
1090                         ext4_std_error(sb, err);
1091                         goto out;
1092                 }
1093                 ext4_lock_group(sb, group);
1094                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
1095                 if (ret2) {
1096                         /* Someone already took the bit. Repeat the search
1097                          * with lock held.
1098                          */
1099                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1100                         if (ret2) {
1101                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
1102                                 ret2 = 0;
1103                         } else {
1104                                 ret2 = 1; /* we didn't grab the inode */
1105                         }
1106                 }
1107                 ext4_unlock_group(sb, group);
1108                 ino++;          /* the inode bitmap is zero-based */
1109                 if (!ret2)
1110                         goto got; /* we grabbed the inode! */
1111
1112                 if (ino < EXT4_INODES_PER_GROUP(sb))
1113                         goto repeat_in_this_group;
1114 next_group:
1115                 if (++group == ngroups)
1116                         group = 0;
1117         }
1118         err = -ENOSPC;
1119         goto out;
1120
1121 got:
1122         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1123         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1124         if (err) {
1125                 ext4_std_error(sb, err);
1126                 goto out;
1127         }
1128
1129         BUFFER_TRACE(group_desc_bh, "get_write_access");
1130         err = ext4_journal_get_write_access(handle, group_desc_bh);
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, block_bitmap_bh);
1148                 if (err) {
1149                         brelse(block_bitmap_bh);
1150                         ext4_std_error(sb, err);
1151                         goto out;
1152                 }
1153
1154                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1155                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1156
1157                 /* recheck and clear flag under lock if we still need to */
1158                 ext4_lock_group(sb, group);
1159                 if (ext4_has_group_desc_csum(sb) &&
1160                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1161                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1162                         ext4_free_group_clusters_set(sb, gdp,
1163                                 ext4_free_clusters_after_init(sb, group, gdp));
1164                         ext4_block_bitmap_csum_set(sb, group, gdp,
1165                                                    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                         down_read(&grp->alloc_sem); /*
1185                                                      * protect vs itable
1186                                                      * lazyinit
1187                                                      */
1188                 }
1189                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1190                 free = EXT4_INODES_PER_GROUP(sb) -
1191                         ext4_itable_unused_count(sb, gdp);
1192                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1193                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1194                         free = 0;
1195                 }
1196                 /*
1197                  * Check the relative inode number against the last used
1198                  * relative inode number in this group. if it is greater
1199                  * we need to update the bg_itable_unused count
1200                  */
1201                 if (ino > free)
1202                         ext4_itable_unused_set(sb, gdp,
1203                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1204                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1205                         up_read(&grp->alloc_sem);
1206         } else {
1207                 ext4_lock_group(sb, group);
1208         }
1209
1210         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1211         if (S_ISDIR(mode)) {
1212                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1213                 if (sbi->s_log_groups_per_flex) {
1214                         ext4_group_t f = ext4_flex_group(sbi, group);
1215
1216                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1217                                                         f)->used_dirs);
1218                 }
1219         }
1220         if (ext4_has_group_desc_csum(sb)) {
1221                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1222                                            EXT4_INODES_PER_GROUP(sb) / 8);
1223                 ext4_group_desc_csum_set(sb, group, gdp);
1224         }
1225         ext4_unlock_group(sb, group);
1226
1227         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1228         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1229         if (err) {
1230                 ext4_std_error(sb, err);
1231                 goto out;
1232         }
1233
1234         percpu_counter_dec(&sbi->s_freeinodes_counter);
1235         if (S_ISDIR(mode))
1236                 percpu_counter_inc(&sbi->s_dirs_counter);
1237
1238         if (sbi->s_log_groups_per_flex) {
1239                 flex_group = ext4_flex_group(sbi, group);
1240                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1241                                                 flex_group)->free_inodes);
1242         }
1243
1244         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1245         /* This is the optimal IO size (for stat), not the fs block size */
1246         inode->i_blocks = 0;
1247         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1248         ei->i_crtime = inode->i_mtime;
1249
1250         memset(ei->i_data, 0, sizeof(ei->i_data));
1251         ei->i_dir_start_lookup = 0;
1252         ei->i_disksize = 0;
1253
1254         /* Don't inherit extent flag from directory, amongst others. */
1255         ei->i_flags =
1256                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1257         ei->i_flags |= i_flags;
1258         ei->i_file_acl = 0;
1259         ei->i_dtime = 0;
1260         ei->i_block_group = group;
1261         ei->i_last_alloc_group = ~0;
1262
1263         ext4_set_inode_flags(inode, true);
1264         if (IS_DIRSYNC(inode))
1265                 ext4_handle_sync(handle);
1266         if (insert_inode_locked(inode) < 0) {
1267                 /*
1268                  * Likely a bitmap corruption causing inode to be allocated
1269                  * twice.
1270                  */
1271                 err = -EIO;
1272                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1273                            inode->i_ino);
1274                 ext4_mark_group_bitmap_corrupted(sb, group,
1275                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1276                 goto out;
1277         }
1278         inode->i_generation = prandom_u32();
1279
1280         /* Precompute checksum seed for inode metadata */
1281         if (ext4_has_metadata_csum(sb)) {
1282                 __u32 csum;
1283                 __le32 inum = cpu_to_le32(inode->i_ino);
1284                 __le32 gen = cpu_to_le32(inode->i_generation);
1285                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1286                                    sizeof(inum));
1287                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1288                                               sizeof(gen));
1289         }
1290
1291         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1292         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1293
1294         ei->i_extra_isize = sbi->s_want_extra_isize;
1295         ei->i_inline_off = 0;
1296         if (ext4_has_feature_inline_data(sb) &&
1297             (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1298                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1299         ret = inode;
1300         err = dquot_alloc_inode(inode);
1301         if (err)
1302                 goto fail_drop;
1303
1304         /*
1305          * Since the encryption xattr will always be unique, create it first so
1306          * that it's less likely to end up in an external xattr block and
1307          * prevent its deduplication.
1308          */
1309         if (encrypt) {
1310                 err = fscrypt_set_context(inode, handle);
1311                 if (err)
1312                         goto fail_free_drop;
1313         }
1314
1315         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1316                 err = ext4_init_acl(handle, inode, dir);
1317                 if (err)
1318                         goto fail_free_drop;
1319
1320                 err = ext4_init_security(handle, inode, dir, qstr);
1321                 if (err)
1322                         goto fail_free_drop;
1323         }
1324
1325         if (ext4_has_feature_extents(sb)) {
1326                 /* set extent flag only for directory, file and normal symlink*/
1327                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1328                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1329                         ext4_ext_tree_init(handle, inode);
1330                 }
1331         }
1332
1333         if (ext4_handle_valid(handle)) {
1334                 ei->i_sync_tid = handle->h_transaction->t_tid;
1335                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1336         }
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         /* This should not happen, but just to be sure check this */
1521         if (sb_rdonly(sb)) {
1522                 ret = 1;
1523                 goto out;
1524         }
1525
1526         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1527         if (!gdp)
1528                 goto out;
1529
1530         /*
1531          * We do not need to lock this, because we are the only one
1532          * handling this flag.
1533          */
1534         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1535                 goto out;
1536
1537         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1538         if (IS_ERR(handle)) {
1539                 ret = PTR_ERR(handle);
1540                 goto out;
1541         }
1542
1543         down_write(&grp->alloc_sem);
1544         /*
1545          * If inode bitmap was already initialized there may be some
1546          * used inodes so we need to skip blocks with used inodes in
1547          * inode table.
1548          */
1549         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1550                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1551                             ext4_itable_unused_count(sb, gdp);
1552                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1553
1554                 /* Bogus inode unused count? */
1555                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1556                         ext4_error(sb, "Something is wrong with group %u: "
1557                                    "used itable blocks: %d; "
1558                                    "itable unused count: %u",
1559                                    group, used_blks,
1560                                    ext4_itable_unused_count(sb, gdp));
1561                         ret = 1;
1562                         goto err_out;
1563                 }
1564
1565                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1566                 /*
1567                  * Are there some uninitialized inodes in the inode table
1568                  * before the first normal inode?
1569                  */
1570                 if ((used_blks != sbi->s_itb_per_group) &&
1571                      (used_inos < EXT4_FIRST_INO(sb))) {
1572                         ext4_error(sb, "Something is wrong with group %u: "
1573                                    "itable unused count: %u; "
1574                                    "itables initialized count: %ld",
1575                                    group, ext4_itable_unused_count(sb, gdp),
1576                                    used_inos);
1577                         ret = 1;
1578                         goto err_out;
1579                 }
1580         }
1581
1582         blk = ext4_inode_table(sb, gdp) + used_blks;
1583         num = sbi->s_itb_per_group - used_blks;
1584
1585         BUFFER_TRACE(group_desc_bh, "get_write_access");
1586         ret = ext4_journal_get_write_access(handle,
1587                                             group_desc_bh);
1588         if (ret)
1589                 goto err_out;
1590
1591         /*
1592          * Skip zeroout if the inode table is full. But we set the ZEROED
1593          * flag anyway, because obviously, when it is full it does not need
1594          * further zeroing.
1595          */
1596         if (unlikely(num == 0))
1597                 goto skip_zeroout;
1598
1599         ext4_debug("going to zero out inode table in group %d\n",
1600                    group);
1601         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1602         if (ret < 0)
1603                 goto err_out;
1604         if (barrier)
1605                 blkdev_issue_flush(sb->s_bdev);
1606
1607 skip_zeroout:
1608         ext4_lock_group(sb, group);
1609         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1610         ext4_group_desc_csum_set(sb, group, gdp);
1611         ext4_unlock_group(sb, group);
1612
1613         BUFFER_TRACE(group_desc_bh,
1614                      "call ext4_handle_dirty_metadata");
1615         ret = ext4_handle_dirty_metadata(handle, NULL,
1616                                          group_desc_bh);
1617
1618 err_out:
1619         up_write(&grp->alloc_sem);
1620         ext4_journal_stop(handle);
1621 out:
1622         return ret;
1623 }