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 blocks 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 blocks left (min_blocks) 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 freeb, 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         freeb = EXT4_C2B(sbi,
 450                 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
 451         avefreec = freeb;
 452         do_div(avefreec, ngroups);
 453         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 454
 455         if (S_ISDIR(mode) &&
 456             ((parent == d_inode(sb->s_root)) ||
 457              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 458                 int best_ndir = inodes_per_group;
 459                 int ret = -1;
 460
 461                 if (qstr) {
 462                         hinfo.hash_version = DX_HASH_HALF_MD4;
 463                         hinfo.seed = sbi->s_hash_seed;
 464                         ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 465                         grp = hinfo.hash;
 466                 } else
 467                         grp = prandom_u32();
 468                 parent_group = (unsigned)grp % ngroups;
 469                 for (i = 0; i < ngroups; i++) {
 470                         g = (parent_group + i) % ngroups;
 471                         get_orlov_stats(sb, g, flex_size, &stats);
 472                         if (!stats.free_inodes)
 473                                 continue;
 474                         if (stats.used_dirs >= best_ndir)
 475                                 continue;
 476                         if (stats.free_inodes < avefreei)
 477                                 continue;
 478                         if (stats.free_clusters < avefreec)
 479                                 continue;
 480                         grp = g;
 481                         ret = 0;
 482                         best_ndir = stats.used_dirs;
 483                 }
 484                 if (ret)
 485                         goto fallback;
 486         found_flex_bg:
 487                 if (flex_size == 1) {
 488                         *group = grp;
 489                         return 0;
 490                 }
 491
 492                 /*
 493                  * We pack inodes at the beginning of the flexgroup's
 494                  * inode tables.  Block allocation decisions will do
 495                  * something similar, although regular files will
 496                  * start at 2nd block group of the flexgroup.  See
 497                  * ext4_ext_find_goal() and ext4_find_near().
 498                  */
 499                 grp *= flex_size;
 500                 for (i = 0; i < flex_size; i++) {
 501                         if (grp+i >= real_ngroups)
 502                                 break;
 503                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 504                         if (desc && ext4_free_inodes_count(sb, desc)) {
 505                                 *group = grp+i;
 506                                 return 0;
 507                         }
 508                 }
 509                 goto fallback;
 510         }
 511
 512         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 513         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 514         if (min_inodes < 1)
 515                 min_inodes = 1;
 516         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 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 = -EFSCORRUPTED;
 759
 760         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
 761                 goto out;
 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 || !group_desc_bh) {
 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, group, gdp,
 817                                                    block_bitmap_bh);
 818                         ext4_group_desc_csum_set(sb, group, gdp);
 819                 }
 820                 ext4_unlock_group(sb, group);
 821                 brelse(block_bitmap_bh);
 822
 823                 if (err) {
 824                         ext4_std_error(sb, err);
 825                         goto out;
 826                 }
 827         }
 828
 829         /* Update the relevant bg descriptor fields */
 830         if (ext4_has_group_desc_csum(sb)) {
 831                 int free;
 832
 833                 ext4_lock_group(sb, group); /* while we modify the bg desc */
 834                 free = EXT4_INODES_PER_GROUP(sb) -
 835                         ext4_itable_unused_count(sb, gdp);
 836                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 837                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
 838                         free = 0;
 839                 }
 840
 841                 /*
 842                  * Check the relative inode number against the last used
 843                  * relative inode number in this group. if it is greater
 844                  * we need to update the bg_itable_unused count
 845                  */
 846                 if (bit >= free)
 847                         ext4_itable_unused_set(sb, gdp,
 848                                         (EXT4_INODES_PER_GROUP(sb) - bit - 1));
 849         } else {
 850                 ext4_lock_group(sb, group);
 851         }
 852
 853         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
 854         if (ext4_has_group_desc_csum(sb)) {
 855                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
 856                                            EXT4_INODES_PER_GROUP(sb) / 8);
 857                 ext4_group_desc_csum_set(sb, group, gdp);
 858         }
 859
 860         ext4_unlock_group(sb, group);
 861         err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
 862         sync_dirty_buffer(group_desc_bh);
 863 out:
 864         return err;
 865 }
 866
 867 static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
 868                                             bool encrypt)
 869 {
 870         struct super_block *sb = dir->i_sb;
 871         int nblocks = 0;
 872 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 873         struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 874
 875         if (IS_ERR(p))
 876                 return PTR_ERR(p);
 877         if (p) {
 878                 int acl_size = p->a_count * sizeof(ext4_acl_entry);
 879
 880                 nblocks += (S_ISDIR(mode) ? 2 : 1) *
 881                         __ext4_xattr_set_credits(sb, NULL /* inode */,
 882                                                  NULL /* block_bh */, acl_size,
 883                                                  true /* is_create */);
 884                 posix_acl_release(p);
 885         }
 886 #endif
 887
 888 #ifdef CONFIG_SECURITY
 889         {
 890                 int num_security_xattrs = 1;
 891
 892 #ifdef CONFIG_INTEGRITY
 893                 num_security_xattrs++;
 894 #endif
 895                 /*
 896                  * We assume that security xattrs are never more than 1k.
 897                  * In practice they are under 128 bytes.
 898                  */
 899                 nblocks += num_security_xattrs *
 900                         __ext4_xattr_set_credits(sb, NULL /* inode */,
 901                                                  NULL /* block_bh */, 1024,
 902                                                  true /* is_create */);
 903         }
 904 #endif
 905         if (encrypt)
 906                 nblocks += __ext4_xattr_set_credits(sb,
 907                                                     NULL /* inode */,
 908                                                     NULL /* block_bh */,
 909                                                     FSCRYPT_SET_CONTEXT_MAX_SIZE,
 910                                                     true /* is_create */);
 911         return nblocks;
 912 }
 913
 914 /*
 915  * There are two policies for allocating an inode.  If the new inode is
 916  * a directory, then a forward search is made for a block group with both
 917  * free space and a low directory-to-inode ratio; if that fails, then of
 918  * the groups with above-average free space, that group with the fewest
 919  * directories already is chosen.
 920  *
 921  * For other inodes, search forward from the parent directory's block
 922  * group to find a free inode.
 923  */
 924 struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 925                                handle_t *handle, struct inode *dir,
 926                                umode_t mode, const struct qstr *qstr,
 927                                __u32 goal, uid_t *owner, __u32 i_flags,
 928                                int handle_type, unsigned int line_no,
 929                                int nblocks)
 930 {
 931         struct super_block *sb;
 932         struct buffer_head *inode_bitmap_bh = NULL;
 933         struct buffer_head *group_desc_bh;
 934         ext4_group_t ngroups, group = 0;
 935         unsigned long ino = 0;
 936         struct inode *inode;
 937         struct ext4_group_desc *gdp = NULL;
 938         struct ext4_inode_info *ei;
 939         struct ext4_sb_info *sbi;
 940         int ret2, err;
 941         struct inode *ret;
 942         ext4_group_t i;
 943         ext4_group_t flex_group;
 944         struct ext4_group_info *grp = NULL;
 945         bool encrypt = false;
 946
 947         /* Cannot create files in a deleted directory */
 948         if (!dir || !dir->i_nlink)
 949                 return ERR_PTR(-EPERM);
 950
 951         sb = dir->i_sb;
 952         sbi = EXT4_SB(sb);
 953
 954         if (unlikely(ext4_forced_shutdown(sbi)))
 955                 return ERR_PTR(-EIO);
 956
 957         ngroups = ext4_get_groups_count(sb);
 958         trace_ext4_request_inode(dir, mode);
 959         inode = new_inode(sb);
 960         if (!inode)
 961                 return ERR_PTR(-ENOMEM);
 962         ei = EXT4_I(inode);
 963
 964         /*
 965          * Initialize owners and quota early so that we don't have to account
 966          * for quota initialization worst case in standard inode creating
 967          * transaction
 968          */
 969         if (owner) {
 970                 inode->i_mode = mode;
 971                 i_uid_write(inode, owner[0]);
 972                 i_gid_write(inode, owner[1]);
 973         } else if (test_opt(sb, GRPID)) {
 974                 inode->i_mode = mode;
 975                 inode_fsuid_set(inode, mnt_userns);
 976                 inode->i_gid = dir->i_gid;
 977         } else
 978                 inode_init_owner(mnt_userns, inode, dir, mode);
 979
 980         if (ext4_has_feature_project(sb) &&
 981             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 982                 ei->i_projid = EXT4_I(dir)->i_projid;
 983         else
 984                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 985
 986         if (!(i_flags & EXT4_EA_INODE_FL)) {
 987                 err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
 988                 if (err)
 989                         goto out;
 990         }
 991
 992         err = dquot_initialize(inode);
 993         if (err)
 994                 goto out;
 995
 996         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 997                 ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
 998                 if (ret2 < 0) {
 999                         err = ret2;
1000                         goto out;
1001                 }
1002                 nblocks += ret2;
1003         }
1004
1005         if (!goal)
1006                 goal = sbi->s_inode_goal;
1007
1008         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
1009                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
1010                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
1011                 ret2 = 0;
1012                 goto got_group;
1013         }
1014
1015         if (S_ISDIR(mode))
1016                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
1017         else
1018                 ret2 = find_group_other(sb, dir, &group, mode);
1019
1020 got_group:
1021         EXT4_I(dir)->i_last_alloc_group = group;
1022         err = -ENOSPC;
1023         if (ret2 == -1)
1024                 goto out;
1025
1026         /*
1027          * Normally we will only go through one pass of this loop,
1028          * unless we get unlucky and it turns out the group we selected
1029          * had its last inode grabbed by someone else.
1030          */
1031         for (i = 0; i < ngroups; i++, ino = 0) {
1032                 err = -EIO;
1033
1034                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1035                 if (!gdp)
1036                         goto out;
1037
1038                 /*
1039                  * Check free inodes count before loading bitmap.
1040                  */
1041                 if (ext4_free_inodes_count(sb, gdp) == 0)
1042                         goto next_group;
1043
1044                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1045                         grp = ext4_get_group_info(sb, group);
1046                         /*
1047                          * Skip groups with already-known suspicious inode
1048                          * tables
1049                          */
1050                         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1051                                 goto next_group;
1052                 }
1053
1054                 brelse(inode_bitmap_bh);
1055                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
1056                 /* Skip groups with suspicious inode tables */
1057                 if (((!(sbi->s_mount_state & EXT4_FC_REPLAY))
1058                      && EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) ||
1059                     IS_ERR(inode_bitmap_bh)) {
1060                         inode_bitmap_bh = NULL;
1061                         goto next_group;
1062                 }
1063
1064 repeat_in_this_group:
1065                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1066                 if (!ret2)
1067                         goto next_group;
1068
1069                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
1070                         ext4_error(sb, "reserved inode found cleared - "
1071                                    "inode=%lu", ino + 1);
1072                         ext4_mark_group_bitmap_corrupted(sb, group,
1073                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1074                         goto next_group;
1075                 }
1076
1077                 if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
1078                         BUG_ON(nblocks <= 0);
1079                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
1080                                  handle_type, nblocks, 0,
1081                                  ext4_trans_default_revoke_credits(sb));
1082                         if (IS_ERR(handle)) {
1083                                 err = PTR_ERR(handle);
1084                                 ext4_std_error(sb, err);
1085                                 goto out;
1086                         }
1087                 }
1088                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
1089                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
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                 if (ino < EXT4_INODES_PER_GROUP(sb))
1114                         goto repeat_in_this_group;
1115 next_group:
1116                 if (++group == ngroups)
1117                         group = 0;
1118         }
1119         err = -ENOSPC;
1120         goto out;
1121
1122 got:
1123         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1124         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1125         if (err) {
1126                 ext4_std_error(sb, err);
1127                 goto out;
1128         }
1129
1130         BUFFER_TRACE(group_desc_bh, "get_write_access");
1131         err = ext4_journal_get_write_access(handle, group_desc_bh);
1132         if (err) {
1133                 ext4_std_error(sb, err);
1134                 goto out;
1135         }
1136
1137         /* We may have to initialize the block bitmap if it isn't already */
1138         if (ext4_has_group_desc_csum(sb) &&
1139             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1140                 struct buffer_head *block_bitmap_bh;
1141
1142                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1143                 if (IS_ERR(block_bitmap_bh)) {
1144                         err = PTR_ERR(block_bitmap_bh);
1145                         goto out;
1146                 }
1147                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1148                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
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, group, gdp,
1166                                                    block_bitmap_bh);
1167                         ext4_group_desc_csum_set(sb, group, gdp);
1168                 }
1169                 ext4_unlock_group(sb, group);
1170                 brelse(block_bitmap_bh);
1171
1172                 if (err) {
1173                         ext4_std_error(sb, err);
1174                         goto out;
1175                 }
1176         }
1177
1178         /* Update the relevant bg descriptor fields */
1179         if (ext4_has_group_desc_csum(sb)) {
1180                 int free;
1181                 struct ext4_group_info *grp = NULL;
1182
1183                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1184                         grp = ext4_get_group_info(sb, group);
1185                         down_read(&grp->alloc_sem); /*
1186                                                      * protect vs itable
1187                                                      * lazyinit
1188                                                      */
1189                 }
1190                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1191                 free = EXT4_INODES_PER_GROUP(sb) -
1192                         ext4_itable_unused_count(sb, gdp);
1193                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1194                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1195                         free = 0;
1196                 }
1197                 /*
1198                  * Check the relative inode number against the last used
1199                  * relative inode number in this group. if it is greater
1200                  * we need to update the bg_itable_unused count
1201                  */
1202                 if (ino > free)
1203                         ext4_itable_unused_set(sb, gdp,
1204                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1205                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1206                         up_read(&grp->alloc_sem);
1207         } else {
1208                 ext4_lock_group(sb, group);
1209         }
1210
1211         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1212         if (S_ISDIR(mode)) {
1213                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1214                 if (sbi->s_log_groups_per_flex) {
1215                         ext4_group_t f = ext4_flex_group(sbi, group);
1216
1217                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1218                                                         f)->used_dirs);
1219                 }
1220         }
1221         if (ext4_has_group_desc_csum(sb)) {
1222                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1223                                            EXT4_INODES_PER_GROUP(sb) / 8);
1224                 ext4_group_desc_csum_set(sb, group, gdp);
1225         }
1226         ext4_unlock_group(sb, group);
1227
1228         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1229         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1230         if (err) {
1231                 ext4_std_error(sb, err);
1232                 goto out;
1233         }
1234
1235         percpu_counter_dec(&sbi->s_freeinodes_counter);
1236         if (S_ISDIR(mode))
1237                 percpu_counter_inc(&sbi->s_dirs_counter);
1238
1239         if (sbi->s_log_groups_per_flex) {
1240                 flex_group = ext4_flex_group(sbi, group);
1241                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1242                                                 flex_group)->free_inodes);
1243         }
1244
1245         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1246         /* This is the optimal IO size (for stat), not the fs block size */
1247         inode->i_blocks = 0;
1248         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1249         ei->i_crtime = inode->i_mtime;
1250
1251         memset(ei->i_data, 0, sizeof(ei->i_data));
1252         ei->i_dir_start_lookup = 0;
1253         ei->i_disksize = 0;
1254
1255         /* Don't inherit extent flag from directory, amongst others. */
1256         ei->i_flags =
1257                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1258         ei->i_flags |= i_flags;
1259         ei->i_file_acl = 0;
1260         ei->i_dtime = 0;
1261         ei->i_block_group = group;
1262         ei->i_last_alloc_group = ~0;
1263
1264         ext4_set_inode_flags(inode, true);
1265         if (IS_DIRSYNC(inode))
1266                 ext4_handle_sync(handle);
1267         if (insert_inode_locked(inode) < 0) {
1268                 /*
1269                  * Likely a bitmap corruption causing inode to be allocated
1270                  * twice.
1271                  */
1272                 err = -EIO;
1273                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1274                            inode->i_ino);
1275                 ext4_mark_group_bitmap_corrupted(sb, group,
1276                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1277                 goto out;
1278         }
1279         inode->i_generation = prandom_u32();
1280
1281         /* Precompute checksum seed for inode metadata */
1282         if (ext4_has_metadata_csum(sb)) {
1283                 __u32 csum;
1284                 __le32 inum = cpu_to_le32(inode->i_ino);
1285                 __le32 gen = cpu_to_le32(inode->i_generation);
1286                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1287                                    sizeof(inum));
1288                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1289                                               sizeof(gen));
1290         }
1291
1292         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1293         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1294
1295         ei->i_extra_isize = sbi->s_want_extra_isize;
1296         ei->i_inline_off = 0;
1297         if (ext4_has_feature_inline_data(sb) &&
1298             (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1299                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1300         ret = inode;
1301         err = dquot_alloc_inode(inode);
1302         if (err)
1303                 goto fail_drop;
1304
1305         /*
1306          * Since the encryption xattr will always be unique, create it first so
1307          * that it's less likely to end up in an external xattr block and
1308          * prevent its deduplication.
1309          */
1310         if (encrypt) {
1311                 err = fscrypt_set_context(inode, handle);
1312                 if (err)
1313                         goto fail_free_drop;
1314         }
1315
1316         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1317                 err = ext4_init_acl(handle, inode, dir);
1318                 if (err)
1319                         goto fail_free_drop;
1320
1321                 err = ext4_init_security(handle, inode, dir, qstr);
1322                 if (err)
1323                         goto fail_free_drop;
1324         }
1325
1326         if (ext4_has_feature_extents(sb)) {
1327                 /* set extent flag only for directory, file and normal symlink*/
1328                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1329                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1330                         ext4_ext_tree_init(handle, inode);
1331                 }
1332         }
1333
1334         if (ext4_handle_valid(handle)) {
1335                 ei->i_sync_tid = handle->h_transaction->t_tid;
1336                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1337         }
1338
1339         err = ext4_mark_inode_dirty(handle, inode);
1340         if (err) {
1341                 ext4_std_error(sb, err);
1342                 goto fail_free_drop;
1343         }
1344
1345         ext4_debug("allocating inode %lu\n", inode->i_ino);
1346         trace_ext4_allocate_inode(inode, dir, mode);
1347         brelse(inode_bitmap_bh);
1348         return ret;
1349
1350 fail_free_drop:
1351         dquot_free_inode(inode);
1352 fail_drop:
1353         clear_nlink(inode);
1354         unlock_new_inode(inode);
1355 out:
1356         dquot_drop(inode);
1357         inode->i_flags |= S_NOQUOTA;
1358         iput(inode);
1359         brelse(inode_bitmap_bh);
1360         return ERR_PTR(err);
1361 }
1362
1363 /* Verify that we are loading a valid orphan from disk */
1364 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1365 {
1366         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1367         ext4_group_t block_group;
1368         int bit;
1369         struct buffer_head *bitmap_bh = NULL;
1370         struct inode *inode = NULL;
1371         int err = -EFSCORRUPTED;
1372
1373         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1374                 goto bad_orphan;
1375
1376         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1377         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1378         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1379         if (IS_ERR(bitmap_bh))
1380                 return ERR_CAST(bitmap_bh);
1381
1382         /* Having the inode bit set should be a 100% indicator that this
1383          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1384          * inodes that were being truncated, so we can't check i_nlink==0.
1385          */
1386         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1387                 goto bad_orphan;
1388
1389         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1390         if (IS_ERR(inode)) {
1391                 err = PTR_ERR(inode);
1392                 ext4_error_err(sb, -err,
1393                                "couldn't read orphan inode %lu (err %d)",
1394                                ino, err);
1395                 brelse(bitmap_bh);
1396                 return inode;
1397         }
1398
1399         /*
1400          * If the orphans has i_nlinks > 0 then it should be able to
1401          * be truncated, otherwise it won't be removed from the orphan
1402          * list during processing and an infinite loop will result.
1403          * Similarly, it must not be a bad inode.
1404          */
1405         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1406             is_bad_inode(inode))
1407                 goto bad_orphan;
1408
1409         if (NEXT_ORPHAN(inode) > max_ino)
1410                 goto bad_orphan;
1411         brelse(bitmap_bh);
1412         return inode;
1413
1414 bad_orphan:
1415         ext4_error(sb, "bad orphan inode %lu", ino);
1416         if (bitmap_bh)
1417                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1418                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1419                        ext4_test_bit(bit, bitmap_bh->b_data));
1420         if (inode) {
1421                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1422                        is_bad_inode(inode));
1423                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1424                        NEXT_ORPHAN(inode));
1425                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1426                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1427                 /* Avoid freeing blocks if we got a bad deleted inode */
1428                 if (inode->i_nlink == 0)
1429                         inode->i_blocks = 0;
1430                 iput(inode);
1431         }
1432         brelse(bitmap_bh);
1433         return ERR_PTR(err);
1434 }
1435
1436 unsigned long ext4_count_free_inodes(struct super_block *sb)
1437 {
1438         unsigned long desc_count;
1439         struct ext4_group_desc *gdp;
1440         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1441 #ifdef EXT4FS_DEBUG
1442         struct ext4_super_block *es;
1443         unsigned long bitmap_count, x;
1444         struct buffer_head *bitmap_bh = NULL;
1445
1446         es = EXT4_SB(sb)->s_es;
1447         desc_count = 0;
1448         bitmap_count = 0;
1449         gdp = NULL;
1450         for (i = 0; i < ngroups; i++) {
1451                 gdp = ext4_get_group_desc(sb, i, NULL);
1452                 if (!gdp)
1453                         continue;
1454                 desc_count += ext4_free_inodes_count(sb, gdp);
1455                 brelse(bitmap_bh);
1456                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1457                 if (IS_ERR(bitmap_bh)) {
1458                         bitmap_bh = NULL;
1459                         continue;
1460                 }
1461
1462                 x = ext4_count_free(bitmap_bh->b_data,
1463                                     EXT4_INODES_PER_GROUP(sb) / 8);
1464                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1465                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1466                 bitmap_count += x;
1467         }
1468         brelse(bitmap_bh);
1469         printk(KERN_DEBUG "ext4_count_free_inodes: "
1470                "stored = %u, computed = %lu, %lu\n",
1471                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1472         return desc_count;
1473 #else
1474         desc_count = 0;
1475         for (i = 0; i < ngroups; i++) {
1476                 gdp = ext4_get_group_desc(sb, i, NULL);
1477                 if (!gdp)
1478                         continue;
1479                 desc_count += ext4_free_inodes_count(sb, gdp);
1480                 cond_resched();
1481         }
1482         return desc_count;
1483 #endif
1484 }
1485
1486 /* Called at mount-time, super-block is locked */
1487 unsigned long ext4_count_dirs(struct super_block * sb)
1488 {
1489         unsigned long count = 0;
1490         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1491
1492         for (i = 0; i < ngroups; i++) {
1493                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1494                 if (!gdp)
1495                         continue;
1496                 count += ext4_used_dirs_count(sb, gdp);
1497         }
1498         return count;
1499 }
1500
1501 /*
1502  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1503  * inode table. Must be called without any spinlock held. The only place
1504  * where it is called from on active part of filesystem is ext4lazyinit
1505  * thread, so we do not need any special locks, however we have to prevent
1506  * inode allocation from the current group, so we take alloc_sem lock, to
1507  * block ext4_new_inode() until we are finished.
1508  */
1509 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1510                                  int barrier)
1511 {
1512         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1513         struct ext4_sb_info *sbi = EXT4_SB(sb);
1514         struct ext4_group_desc *gdp = NULL;
1515         struct buffer_head *group_desc_bh;
1516         handle_t *handle;
1517         ext4_fsblk_t blk;
1518         int num, ret = 0, used_blks = 0;
1519         unsigned long used_inos = 0;
1520
1521         /* This should not happen, but just to be sure check this */
1522         if (sb_rdonly(sb)) {
1523                 ret = 1;
1524                 goto out;
1525         }
1526
1527         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1528         if (!gdp)
1529                 goto out;
1530
1531         /*
1532          * We do not need to lock this, because we are the only one
1533          * handling this flag.
1534          */
1535         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1536                 goto out;
1537
1538         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1539         if (IS_ERR(handle)) {
1540                 ret = PTR_ERR(handle);
1541                 goto out;
1542         }
1543
1544         down_write(&grp->alloc_sem);
1545         /*
1546          * If inode bitmap was already initialized there may be some
1547          * used inodes so we need to skip blocks with used inodes in
1548          * inode table.
1549          */
1550         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1551                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1552                             ext4_itable_unused_count(sb, gdp);
1553                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1554
1555                 /* Bogus inode unused count? */
1556                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1557                         ext4_error(sb, "Something is wrong with group %u: "
1558                                    "used itable blocks: %d; "
1559                                    "itable unused count: %u",
1560                                    group, used_blks,
1561                                    ext4_itable_unused_count(sb, gdp));
1562                         ret = 1;
1563                         goto err_out;
1564                 }
1565
1566                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1567                 /*
1568                  * Are there some uninitialized inodes in the inode table
1569                  * before the first normal inode?
1570                  */
1571                 if ((used_blks != sbi->s_itb_per_group) &&
1572                      (used_inos < EXT4_FIRST_INO(sb))) {
1573                         ext4_error(sb, "Something is wrong with group %u: "
1574                                    "itable unused count: %u; "
1575                                    "itables initialized count: %ld",
1576                                    group, ext4_itable_unused_count(sb, gdp),
1577                                    used_inos);
1578                         ret = 1;
1579                         goto err_out;
1580                 }
1581         }
1582
1583         blk = ext4_inode_table(sb, gdp) + used_blks;
1584         num = sbi->s_itb_per_group - used_blks;
1585
1586         BUFFER_TRACE(group_desc_bh, "get_write_access");
1587         ret = ext4_journal_get_write_access(handle,
1588                                             group_desc_bh);
1589         if (ret)
1590                 goto err_out;
1591
1592         /*
1593          * Skip zeroout if the inode table is full. But we set the ZEROED
1594          * flag anyway, because obviously, when it is full it does not need
1595          * further zeroing.
1596          */
1597         if (unlikely(num == 0))
1598                 goto skip_zeroout;
1599
1600         ext4_debug("going to zero out inode table in group %d\n",
1601                    group);
1602         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1603         if (ret < 0)
1604                 goto err_out;
1605         if (barrier)
1606                 blkdev_issue_flush(sb->s_bdev);
1607
1608 skip_zeroout:
1609         ext4_lock_group(sb, group);
1610         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1611         ext4_group_desc_csum_set(sb, group, gdp);
1612         ext4_unlock_group(sb, group);
1613
1614         BUFFER_TRACE(group_desc_bh,
1615                      "call ext4_handle_dirty_metadata");
1616         ret = ext4_handle_dirty_metadata(handle, NULL,
1617                                          group_desc_bh);
1618
1619 err_out:
1620         up_write(&grp->alloc_sem);
1621         ext4_journal_stop(handle);
1622 out:
1623         return ret;
1624 }