linux/fs/ext4/ialloc.c
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   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 */
  55void 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
  69void 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
  79static 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);
 112verified:
 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 */
 123static struct buffer_head *
 124ext4_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
 209verify:
 210        err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 211        if (err)
 212                goto out;
 213        return bh;
 214out:
 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 */
 235void 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);
 346out:
 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
 358error_return:
 359        brelse(bitmap_bh);
 360        ext4_std_error(sb, fatal);
 361}
 362
 363struct 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 */
 374static 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
 421static 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
 539fallback:
 540        ngroups = real_ngroups;
 541        avefreei = freei / ngroups;
 542fallback_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
 568static 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
 673static 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;
 711out:
 712        brelse(bh);
 713        return ret;
 714}
 715
 716static 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
 722next:
 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;
 737not_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
 750int 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);
 862out:
 863        return err;
 864}
 865
 866static 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 */
 923struct 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
1019got_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
1063repeat_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;
1114next_group:
1115                if (++group == ngroups)
1116                        group = 0;
1117        }
1118        err = -ENOSPC;
1119        goto out;
1120
1121got:
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
1349fail_free_drop:
1350        dquot_free_inode(inode);
1351fail_drop:
1352        clear_nlink(inode);
1353        unlock_new_inode(inode);
1354out:
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 */
1363struct 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
1413bad_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
1435unsigned 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 */
1486unsigned 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 */
1508int 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
1607skip_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
1618err_out:
1619        up_write(&grp->alloc_sem);
1620        ext4_journal_stop(handle);
1621out:
1622        return ret;
1623}
1624