fs/ext4/ialloc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/ialloc.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  BSD ufs-inspired inode and directory allocation by
  11  *  Stephen Tweedie (sct@redhat.com), 1993
  12  *  Big-endian to little-endian byte-swapping/bitmaps by
  13  *        David S. Miller (davem@caip.rutgers.edu), 1995
  14  */
  15
  16 #include <linux/time.h>
  17 #include <linux/fs.h>
  18 #include <linux/stat.h>
  19 #include <linux/string.h>
  20 #include <linux/quotaops.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/random.h>
  23 #include <linux/bitops.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/cred.h>
  26
  27 #include <asm/byteorder.h>
  28
  29 #include "ext4.h"
  30 #include "ext4_jbd2.h"
  31 #include "xattr.h"
  32 #include "acl.h"
  33
  34 #include <trace/events/ext4.h>
  35
  36 /*
  37  * ialloc.c contains the inodes allocation and deallocation routines
  38  */
  39
  40 /*
  41  * The free inodes are managed by bitmaps.  A file system contains several
  42  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
  43  * block for inodes, N blocks for the inode table and data blocks.
  44  *
  45  * The file system contains group descriptors which are located after the
  46  * super block.  Each descriptor contains the number of the bitmap block and
  47  * the free blocks count in the block.
  48  */
  49
  50 /*
  51  * To avoid calling the atomic setbit hundreds or thousands of times, we only
  52  * need to use it within a single byte (to ensure we get endianness right).
  53  * We can use memset for the rest of the bitmap as there are no other users.
  54  */
  55 void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
  56 {
  57         int i;
  58
  59         if (start_bit >= end_bit)
  60                 return;
  61
  62         ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
  63         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
  64                 ext4_set_bit(i, bitmap);
  65         if (i < end_bit)
  66                 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
  67 }
  68
  69 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
  70 {
  71         if (uptodate) {
  72                 set_buffer_uptodate(bh);
  73                 set_bitmap_uptodate(bh);
  74         }
  75         unlock_buffer(bh);
  76         put_bh(bh);
  77 }
  78
  79 static int ext4_validate_inode_bitmap(struct super_block *sb,
  80                                       struct ext4_group_desc *desc,
  81                                       ext4_group_t block_group,
  82                                       struct buffer_head *bh)
  83 {
  84         ext4_fsblk_t    blk;
  85         struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
  86         struct ext4_sb_info *sbi = EXT4_SB(sb);
  87
  88         if (buffer_verified(bh))
  89                 return 0;
  90         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
  91                 return -EFSCORRUPTED;
  92
  93         ext4_lock_group(sb, block_group);
  94         if (buffer_verified(bh))
  95                 goto verified;
  96         blk = ext4_inode_bitmap(sb, desc);
  97         if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
  98                                            EXT4_INODES_PER_GROUP(sb) / 8)) {
  99                 ext4_unlock_group(sb, block_group);
 100                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 101                            "inode_bitmap = %llu", block_group, blk);
 102                 grp = ext4_get_group_info(sb, block_group);
 103                 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 104                         int count;
 105                         count = ext4_free_inodes_count(sb, desc);
 106                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 107                                            count);
 108                 }
 109                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
 110                 return -EFSBADCRC;
 111         }
 112         set_buffer_verified(bh);
 113 verified:
 114         ext4_unlock_group(sb, block_group);
 115         return 0;
 116 }
 117
 118 /*
 119  * Read the inode allocation bitmap for a given block_group, reading
 120  * into the specified slot in the superblock's bitmap cache.
 121  *
 122  * Return buffer_head of bitmap on success or NULL.
 123  */
 124 static struct buffer_head *
 125 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 126 {
 127         struct ext4_group_desc *desc;
 128         struct ext4_sb_info *sbi = EXT4_SB(sb);
 129         struct buffer_head *bh = NULL;
 130         ext4_fsblk_t bitmap_blk;
 131         int err;
 132
 133         desc = ext4_get_group_desc(sb, block_group, NULL);
 134         if (!desc)
 135                 return ERR_PTR(-EFSCORRUPTED);
 136
 137         bitmap_blk = ext4_inode_bitmap(sb, desc);
 138         if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
 139             (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
 140                 ext4_error(sb, "Invalid inode bitmap blk %llu in "
 141                            "block_group %u", bitmap_blk, block_group);
 142                 return ERR_PTR(-EFSCORRUPTED);
 143         }
 144         bh = sb_getblk(sb, bitmap_blk);
 145         if (unlikely(!bh)) {
 146                 ext4_error(sb, "Cannot read inode bitmap - "
 147                             "block_group = %u, inode_bitmap = %llu",
 148                             block_group, bitmap_blk);
 149                 return ERR_PTR(-EIO);
 150         }
 151         if (bitmap_uptodate(bh))
 152                 goto verify;
 153
 154         lock_buffer(bh);
 155         if (bitmap_uptodate(bh)) {
 156                 unlock_buffer(bh);
 157                 goto verify;
 158         }
 159
 160         ext4_lock_group(sb, block_group);
 161         if (ext4_has_group_desc_csum(sb) &&
 162             (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
 163                 if (block_group == 0) {
 164                         ext4_unlock_group(sb, block_group);
 165                         unlock_buffer(bh);
 166                         ext4_error(sb, "Inode bitmap for bg 0 marked "
 167                                    "uninitialized");
 168                         err = -EFSCORRUPTED;
 169                         goto out;
 170                 }
 171                 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 172                 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
 173                                      sb->s_blocksize * 8, bh->b_data);
 174                 set_bitmap_uptodate(bh);
 175                 set_buffer_uptodate(bh);
 176                 set_buffer_verified(bh);
 177                 ext4_unlock_group(sb, block_group);
 178                 unlock_buffer(bh);
 179                 return bh;
 180         }
 181         ext4_unlock_group(sb, block_group);
 182
 183         if (buffer_uptodate(bh)) {
 184                 /*
 185                  * if not uninit if bh is uptodate,
 186                  * bitmap is also uptodate
 187                  */
 188                 set_bitmap_uptodate(bh);
 189                 unlock_buffer(bh);
 190                 goto verify;
 191         }
 192         /*
 193          * submit the buffer_head for reading
 194          */
 195         trace_ext4_load_inode_bitmap(sb, block_group);
 196         bh->b_end_io = ext4_end_bitmap_read;
 197         get_bh(bh);
 198         submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 199         wait_on_buffer(bh);
 200         if (!buffer_uptodate(bh)) {
 201                 put_bh(bh);
 202                 ext4_error(sb, "Cannot read inode bitmap - "
 203                            "block_group = %u, inode_bitmap = %llu",
 204                            block_group, bitmap_blk);
 205                 return ERR_PTR(-EIO);
 206         }
 207
 208 verify:
 209         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 210         if (err)
 211                 goto out;
 212         return bh;
 213 out:
 214         put_bh(bh);
 215         return ERR_PTR(err);
 216 }
 217
 218 /*
 219  * NOTE! When we get the inode, we're the only people
 220  * that have access to it, and as such there are no
 221  * race conditions we have to worry about. The inode
 222  * is not on the hash-lists, and it cannot be reached
 223  * through the filesystem because the directory entry
 224  * has been deleted earlier.
 225  *
 226  * HOWEVER: we must make sure that we get no aliases,
 227  * which means that we have to call "clear_inode()"
 228  * _before_ we mark the inode not in use in the inode
 229  * bitmaps. Otherwise a newly created file might use
 230  * the same inode number (not actually the same pointer
 231  * though), and then we'd have two inodes sharing the
 232  * same inode number and space on the harddisk.
 233  */
 234 void ext4_free_inode(handle_t *handle, struct inode *inode)
 235 {
 236         struct super_block *sb = inode->i_sb;
 237         int is_directory;
 238         unsigned long ino;
 239         struct buffer_head *bitmap_bh = NULL;
 240         struct buffer_head *bh2;
 241         ext4_group_t block_group;
 242         unsigned long bit;
 243         struct ext4_group_desc *gdp;
 244         struct ext4_super_block *es;
 245         struct ext4_sb_info *sbi;
 246         int fatal = 0, err, count, cleared;
 247         struct ext4_group_info *grp;
 248
 249         if (!sb) {
 250                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 251                        "nonexistent device\n", __func__, __LINE__);
 252                 return;
 253         }
 254         if (atomic_read(&inode->i_count) > 1) {
 255                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 256                          __func__, __LINE__, inode->i_ino,
 257                          atomic_read(&inode->i_count));
 258                 return;
 259         }
 260         if (inode->i_nlink) {
 261                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 262                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 263                 return;
 264         }
 265         sbi = EXT4_SB(sb);
 266
 267         ino = inode->i_ino;
 268         ext4_debug("freeing inode %lu\n", ino);
 269         trace_ext4_free_inode(inode);
 270
 271         /*
 272          * Note: we must free any quota before locking the superblock,
 273          * as writing the quota to disk may need the lock as well.
 274          */
 275         dquot_initialize(inode);
 276         dquot_free_inode(inode);
 277         dquot_drop(inode);
 278
 279         is_directory = S_ISDIR(inode->i_mode);
 280
 281         /* Do this BEFORE marking the inode not in use or returning an error */
 282         ext4_clear_inode(inode);
 283
 284         es = EXT4_SB(sb)->s_es;
 285         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 286                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 287                 goto error_return;
 288         }
 289         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 290         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 291         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 292         /* Don't bother if the inode bitmap is corrupt. */
 293         grp = ext4_get_group_info(sb, block_group);
 294         if (IS_ERR(bitmap_bh)) {
 295                 fatal = PTR_ERR(bitmap_bh);
 296                 bitmap_bh = NULL;
 297                 goto error_return;
 298         }
 299         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 300                 fatal = -EFSCORRUPTED;
 301                 goto error_return;
 302         }
 303
 304         BUFFER_TRACE(bitmap_bh, "get_write_access");
 305         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 306         if (fatal)
 307                 goto error_return;
 308
 309         fatal = -ESRCH;
 310         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 311         if (gdp) {
 312                 BUFFER_TRACE(bh2, "get_write_access");
 313                 fatal = ext4_journal_get_write_access(handle, bh2);
 314         }
 315         ext4_lock_group(sb, block_group);
 316         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 317         if (fatal || !cleared) {
 318                 ext4_unlock_group(sb, block_group);
 319                 goto out;
 320         }
 321
 322         count = ext4_free_inodes_count(sb, gdp) + 1;
 323         ext4_free_inodes_set(sb, gdp, count);
 324         if (is_directory) {
 325                 count = ext4_used_dirs_count(sb, gdp) - 1;
 326                 ext4_used_dirs_set(sb, gdp, count);
 327                 percpu_counter_dec(&sbi->s_dirs_counter);
 328         }
 329         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 330                                    EXT4_INODES_PER_GROUP(sb) / 8);
 331         ext4_group_desc_csum_set(sb, block_group, gdp);
 332         ext4_unlock_group(sb, block_group);
 333
 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                 if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 355                         int count;
 356                         count = ext4_free_inodes_count(sb, gdp);
 357                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 358                                            count);
 359                 }
 360                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
 361         }
 362
 363 error_return:
 364         brelse(bitmap_bh);
 365         ext4_std_error(sb, fatal);
 366 }
 367
 368 struct orlov_stats {
 369         __u64 free_clusters;
 370         __u32 free_inodes;
 371         __u32 used_dirs;
 372 };
 373
 374 /*
 375  * Helper function for Orlov's allocator; returns critical information
 376  * for a particular block group or flex_bg.  If flex_size is 1, then g
 377  * is a block group number; otherwise it is flex_bg number.
 378  */
 379 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 380                             int flex_size, struct orlov_stats *stats)
 381 {
 382         struct ext4_group_desc *desc;
 383
 384         if (flex_size > 1) {
 385                 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
 386                                                              s_flex_groups, g);
 387                 stats->free_inodes = atomic_read(&fg->free_inodes);
 388                 stats->free_clusters = atomic64_read(&fg->free_clusters);
 389                 stats->used_dirs = atomic_read(&fg->used_dirs);
 390                 return;
 391         }
 392
 393         desc = ext4_get_group_desc(sb, g, NULL);
 394         if (desc) {
 395                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 396                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 397                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 398         } else {
 399                 stats->free_inodes = 0;
 400                 stats->free_clusters = 0;
 401                 stats->used_dirs = 0;
 402         }
 403 }
 404
 405 /*
 406  * Orlov's allocator for directories.
 407  *
 408  * We always try to spread first-level directories.
 409  *
 410  * If there are blockgroups with both free inodes and free clusters counts
 411  * not worse than average we return one with smallest directory count.
 412  * Otherwise we simply return a random group.
 413  *
 414  * For the rest rules look so:
 415  *
 416  * It's OK to put directory into a group unless
 417  * it has too many directories already (max_dirs) or
 418  * it has too few free inodes left (min_inodes) or
 419  * it has too few free clusters left (min_clusters) or
 420  * Parent's group is preferred, if it doesn't satisfy these
 421  * conditions we search cyclically through the rest. If none
 422  * of the groups look good we just look for a group with more
 423  * free inodes than average (starting at parent's group).
 424  */
 425
 426 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 427                             ext4_group_t *group, umode_t mode,
 428                             const struct qstr *qstr)
 429 {
 430         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 431         struct ext4_sb_info *sbi = EXT4_SB(sb);
 432         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 433         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 434         unsigned int freei, avefreei, grp_free;
 435         ext4_fsblk_t freec, avefreec;
 436         unsigned int ndirs;
 437         int max_dirs, min_inodes;
 438         ext4_grpblk_t min_clusters;
 439         ext4_group_t i, grp, g, ngroups;
 440         struct ext4_group_desc *desc;
 441         struct orlov_stats stats;
 442         int flex_size = ext4_flex_bg_size(sbi);
 443         struct dx_hash_info hinfo;
 444
 445         ngroups = real_ngroups;
 446         if (flex_size > 1) {
 447                 ngroups = (real_ngroups + flex_size - 1) >>
 448                         sbi->s_log_groups_per_flex;
 449                 parent_group >>= sbi->s_log_groups_per_flex;
 450         }
 451
 452         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 453         avefreei = freei / ngroups;
 454         freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
 455         avefreec = freec;
 456         do_div(avefreec, ngroups);
 457         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 458
 459         if (S_ISDIR(mode) &&
 460             ((parent == d_inode(sb->s_root)) ||
 461              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 462                 int best_ndir = inodes_per_group;
 463                 int ret = -1;
 464
 465                 if (qstr) {
 466                         hinfo.hash_version = DX_HASH_HALF_MD4;
 467                         hinfo.seed = sbi->s_hash_seed;
 468                         ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
 469                         grp = hinfo.hash;
 470                 } else
 471                         grp = prandom_u32();
 472                 parent_group = (unsigned)grp % ngroups;
 473                 for (i = 0; i < ngroups; i++) {
 474                         g = (parent_group + i) % ngroups;
 475                         get_orlov_stats(sb, g, flex_size, &stats);
 476                         if (!stats.free_inodes)
 477                                 continue;
 478                         if (stats.used_dirs >= best_ndir)
 479                                 continue;
 480                         if (stats.free_inodes < avefreei)
 481                                 continue;
 482                         if (stats.free_clusters < avefreec)
 483                                 continue;
 484                         grp = g;
 485                         ret = 0;
 486                         best_ndir = stats.used_dirs;
 487                 }
 488                 if (ret)
 489                         goto fallback;
 490         found_flex_bg:
 491                 if (flex_size == 1) {
 492                         *group = grp;
 493                         return 0;
 494                 }
 495
 496                 /*
 497                  * We pack inodes at the beginning of the flexgroup's
 498                  * inode tables.  Block allocation decisions will do
 499                  * something similar, although regular files will
 500                  * start at 2nd block group of the flexgroup.  See
 501                  * ext4_ext_find_goal() and ext4_find_near().
 502                  */
 503                 grp *= flex_size;
 504                 for (i = 0; i < flex_size; i++) {
 505                         if (grp+i >= real_ngroups)
 506                                 break;
 507                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 508                         if (desc && ext4_free_inodes_count(sb, desc)) {
 509                                 *group = grp+i;
 510                                 return 0;
 511                         }
 512                 }
 513                 goto fallback;
 514         }
 515
 516         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 517         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 518         if (min_inodes < 1)
 519                 min_inodes = 1;
 520         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 521
 522         /*
 523          * Start looking in the flex group where we last allocated an
 524          * inode for this parent directory
 525          */
 526         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 527                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 528                 if (flex_size > 1)
 529                         parent_group >>= sbi->s_log_groups_per_flex;
 530         }
 531
 532         for (i = 0; i < ngroups; i++) {
 533                 grp = (parent_group + i) % ngroups;
 534                 get_orlov_stats(sb, grp, flex_size, &stats);
 535                 if (stats.used_dirs >= max_dirs)
 536                         continue;
 537                 if (stats.free_inodes < min_inodes)
 538                         continue;
 539                 if (stats.free_clusters < min_clusters)
 540                         continue;
 541                 goto found_flex_bg;
 542         }
 543
 544 fallback:
 545         ngroups = real_ngroups;
 546         avefreei = freei / ngroups;
 547 fallback_retry:
 548         parent_group = EXT4_I(parent)->i_block_group;
 549         for (i = 0; i < ngroups; i++) {
 550                 grp = (parent_group + i) % ngroups;
 551                 desc = ext4_get_group_desc(sb, grp, NULL);
 552                 if (desc) {
 553                         grp_free = ext4_free_inodes_count(sb, desc);
 554                         if (grp_free && grp_free >= avefreei) {
 555                                 *group = grp;
 556                                 return 0;
 557                         }
 558                 }
 559         }
 560
 561         if (avefreei) {
 562                 /*
 563                  * The free-inodes counter is approximate, and for really small
 564                  * filesystems the above test can fail to find any blockgroups
 565                  */
 566                 avefreei = 0;
 567                 goto fallback_retry;
 568         }
 569
 570         return -1;
 571 }
 572
 573 static int find_group_other(struct super_block *sb, struct inode *parent,
 574                             ext4_group_t *group, umode_t mode)
 575 {
 576         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 577         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 578         struct ext4_group_desc *desc;
 579         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 580
 581         /*
 582          * Try to place the inode is the same flex group as its
 583          * parent.  If we can't find space, use the Orlov algorithm to
 584          * find another flex group, and store that information in the
 585          * parent directory's inode information so that use that flex
 586          * group for future allocations.
 587          */
 588         if (flex_size > 1) {
 589                 int retry = 0;
 590
 591         try_again:
 592                 parent_group &= ~(flex_size-1);
 593                 last = parent_group + flex_size;
 594                 if (last > ngroups)
 595                         last = ngroups;
 596                 for  (i = parent_group; i < last; i++) {
 597                         desc = ext4_get_group_desc(sb, i, NULL);
 598                         if (desc && ext4_free_inodes_count(sb, desc)) {
 599                                 *group = i;
 600                                 return 0;
 601                         }
 602                 }
 603                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 604                         retry = 1;
 605                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 606                         goto try_again;
 607                 }
 608                 /*
 609                  * If this didn't work, use the Orlov search algorithm
 610                  * to find a new flex group; we pass in the mode to
 611                  * avoid the topdir algorithms.
 612                  */
 613                 *group = parent_group + flex_size;
 614                 if (*group > ngroups)
 615                         *group = 0;
 616                 return find_group_orlov(sb, parent, group, mode, NULL);
 617         }
 618
 619         /*
 620          * Try to place the inode in its parent directory
 621          */
 622         *group = parent_group;
 623         desc = ext4_get_group_desc(sb, *group, NULL);
 624         if (desc && ext4_free_inodes_count(sb, desc) &&
 625             ext4_free_group_clusters(sb, desc))
 626                 return 0;
 627
 628         /*
 629          * We're going to place this inode in a different blockgroup from its
 630          * parent.  We want to cause files in a common directory to all land in
 631          * the same blockgroup.  But we want files which are in a different
 632          * directory which shares a blockgroup with our parent to land in a
 633          * different blockgroup.
 634          *
 635          * So add our directory's i_ino into the starting point for the hash.
 636          */
 637         *group = (*group + parent->i_ino) % ngroups;
 638
 639         /*
 640          * Use a quadratic hash to find a group with a free inode and some free
 641          * blocks.
 642          */
 643         for (i = 1; i < ngroups; i <<= 1) {
 644                 *group += i;
 645                 if (*group >= ngroups)
 646                         *group -= ngroups;
 647                 desc = ext4_get_group_desc(sb, *group, NULL);
 648                 if (desc && ext4_free_inodes_count(sb, desc) &&
 649                     ext4_free_group_clusters(sb, desc))
 650                         return 0;
 651         }
 652
 653         /*
 654          * That failed: try linear search for a free inode, even if that group
 655          * has no free blocks.
 656          */
 657         *group = parent_group;
 658         for (i = 0; i < ngroups; i++) {
 659                 if (++*group >= ngroups)
 660                         *group = 0;
 661                 desc = ext4_get_group_desc(sb, *group, NULL);
 662                 if (desc && ext4_free_inodes_count(sb, desc))
 663                         return 0;
 664         }
 665
 666         return -1;
 667 }
 668
 669 /*
 670  * In no journal mode, if an inode has recently been deleted, we want
 671  * to avoid reusing it until we're reasonably sure the inode table
 672  * block has been written back to disk.  (Yes, these values are
 673  * somewhat arbitrary...)
 674  */
 675 #define RECENTCY_MIN    60
 676 #define RECENTCY_DIRTY  300
 677
 678 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 679 {
 680         struct ext4_group_desc  *gdp;
 681         struct ext4_inode       *raw_inode;
 682         struct buffer_head      *bh;
 683         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 684         int offset, ret = 0;
 685         int recentcy = RECENTCY_MIN;
 686         u32 dtime, now;
 687
 688         gdp = ext4_get_group_desc(sb, group, NULL);
 689         if (unlikely(!gdp))
 690                 return 0;
 691
 692         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 693                        (ino / inodes_per_block));
 694         if (!bh || !buffer_uptodate(bh))
 695                 /*
 696                  * If the block is not in the buffer cache, then it
 697                  * must have been written out.
 698                  */
 699                 goto out;
 700
 701         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 702         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 703
 704         /* i_dtime is only 32 bits on disk, but we only care about relative
 705          * times in the range of a few minutes (i.e. long enough to sync a
 706          * recently-deleted inode to disk), so using the low 32 bits of the
 707          * clock (a 68 year range) is enough, see time_before32() */
 708         dtime = le32_to_cpu(raw_inode->i_dtime);
 709         now = ktime_get_real_seconds();
 710         if (buffer_dirty(bh))
 711                 recentcy += RECENTCY_DIRTY;
 712
 713         if (dtime && time_before32(dtime, now) &&
 714             time_before32(now, dtime + recentcy))
 715                 ret = 1;
 716 out:
 717         brelse(bh);
 718         return ret;
 719 }
 720
 721 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 722                           struct buffer_head *bitmap, unsigned long *ino)
 723 {
 724 next:
 725         *ino = ext4_find_next_zero_bit((unsigned long *)
 726                                        bitmap->b_data,
 727                                        EXT4_INODES_PER_GROUP(sb), *ino);
 728         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 729                 return 0;
 730
 731         if ((EXT4_SB(sb)->s_journal == NULL) &&
 732             recently_deleted(sb, group, *ino)) {
 733                 *ino = *ino + 1;
 734                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 735                         goto next;
 736                 return 0;
 737         }
 738
 739         return 1;
 740 }
 741
 742 /*
 743  * There are two policies for allocating an inode.  If the new inode is
 744  * a directory, then a forward search is made for a block group with both
 745  * free space and a low directory-to-inode ratio; if that fails, then of
 746  * the groups with above-average free space, that group with the fewest
 747  * directories already is chosen.
 748  *
 749  * For other inodes, search forward from the parent directory's block
 750  * group to find a free inode.
 751  */
 752 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 753                                umode_t mode, const struct qstr *qstr,
 754                                __u32 goal, uid_t *owner, __u32 i_flags,
 755                                int handle_type, unsigned int line_no,
 756                                int nblocks)
 757 {
 758         struct super_block *sb;
 759         struct buffer_head *inode_bitmap_bh = NULL;
 760         struct buffer_head *group_desc_bh;
 761         ext4_group_t ngroups, group = 0;
 762         unsigned long ino = 0;
 763         struct inode *inode;
 764         struct ext4_group_desc *gdp = NULL;
 765         struct ext4_inode_info *ei;
 766         struct ext4_sb_info *sbi;
 767         int ret2, err;
 768         struct inode *ret;
 769         ext4_group_t i;
 770         ext4_group_t flex_group;
 771         struct ext4_group_info *grp;
 772         int encrypt = 0;
 773
 774         /* Cannot create files in a deleted directory */
 775         if (!dir || !dir->i_nlink)
 776                 return ERR_PTR(-EPERM);
 777
 778         sb = dir->i_sb;
 779         sbi = EXT4_SB(sb);
 780
 781         if (unlikely(ext4_forced_shutdown(sbi)))
 782                 return ERR_PTR(-EIO);
 783
 784         if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
 785             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
 786             !(i_flags & EXT4_EA_INODE_FL)) {
 787                 err = fscrypt_get_encryption_info(dir);
 788                 if (err)
 789                         return ERR_PTR(err);
 790                 if (!fscrypt_has_encryption_key(dir))
 791                         return ERR_PTR(-ENOKEY);
 792                 encrypt = 1;
 793         }
 794
 795         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 796 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 797                 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 798
 799                 if (IS_ERR(p))
 800                         return ERR_CAST(p);
 801                 if (p) {
 802                         int acl_size = p->a_count * sizeof(ext4_acl_entry);
 803
 804                         nblocks += (S_ISDIR(mode) ? 2 : 1) *
 805                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 806                                         NULL /* block_bh */, acl_size,
 807                                         true /* is_create */);
 808                         posix_acl_release(p);
 809                 }
 810 #endif
 811
 812 #ifdef CONFIG_SECURITY
 813                 {
 814                         int num_security_xattrs = 1;
 815
 816 #ifdef CONFIG_INTEGRITY
 817                         num_security_xattrs++;
 818 #endif
 819                         /*
 820                          * We assume that security xattrs are never
 821                          * more than 1k.  In practice they are under
 822                          * 128 bytes.
 823                          */
 824                         nblocks += num_security_xattrs *
 825                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 826                                         NULL /* block_bh */, 1024,
 827                                         true /* is_create */);
 828                 }
 829 #endif
 830                 if (encrypt)
 831                         nblocks += __ext4_xattr_set_credits(sb,
 832                                         NULL /* inode */, NULL /* block_bh */,
 833                                         FSCRYPT_SET_CONTEXT_MAX_SIZE,
 834                                         true /* is_create */);
 835         }
 836
 837         ngroups = ext4_get_groups_count(sb);
 838         trace_ext4_request_inode(dir, mode);
 839         inode = new_inode(sb);
 840         if (!inode)
 841                 return ERR_PTR(-ENOMEM);
 842         ei = EXT4_I(inode);
 843
 844         /*
 845          * Initialize owners and quota early so that we don't have to account
 846          * for quota initialization worst case in standard inode creating
 847          * transaction
 848          */
 849         if (owner) {
 850                 inode->i_mode = mode;
 851                 i_uid_write(inode, owner[0]);
 852                 i_gid_write(inode, owner[1]);
 853         } else if (test_opt(sb, GRPID)) {
 854                 inode->i_mode = mode;
 855                 inode->i_uid = current_fsuid();
 856                 inode->i_gid = dir->i_gid;
 857         } else
 858                 inode_init_owner(inode, dir, mode);
 859
 860         if (ext4_has_feature_project(sb) &&
 861             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 862                 ei->i_projid = EXT4_I(dir)->i_projid;
 863         else
 864                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 865
 866         err = dquot_initialize(inode);
 867         if (err)
 868                 goto out;
 869
 870         if (!goal)
 871                 goal = sbi->s_inode_goal;
 872
 873         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
 874                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
 875                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
 876                 ret2 = 0;
 877                 goto got_group;
 878         }
 879
 880         if (S_ISDIR(mode))
 881                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
 882         else
 883                 ret2 = find_group_other(sb, dir, &group, mode);
 884
 885 got_group:
 886         EXT4_I(dir)->i_last_alloc_group = group;
 887         err = -ENOSPC;
 888         if (ret2 == -1)
 889                 goto out;
 890
 891         /*
 892          * Normally we will only go through one pass of this loop,
 893          * unless we get unlucky and it turns out the group we selected
 894          * had its last inode grabbed by someone else.
 895          */
 896         for (i = 0; i < ngroups; i++, ino = 0) {
 897                 err = -EIO;
 898
 899                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 900                 if (!gdp)
 901                         goto out;
 902
 903                 /*
 904                  * Check free inodes count before loading bitmap.
 905                  */
 906                 if (ext4_free_inodes_count(sb, gdp) == 0)
 907                         goto next_group;
 908
 909                 grp = ext4_get_group_info(sb, group);
 910                 /* Skip groups with already-known suspicious inode tables */
 911                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 912                         goto next_group;
 913
 914                 brelse(inode_bitmap_bh);
 915                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 916                 /* Skip groups with suspicious inode tables */
 917                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 918                     IS_ERR(inode_bitmap_bh)) {
 919                         inode_bitmap_bh = NULL;
 920                         goto next_group;
 921                 }
 922
 923 repeat_in_this_group:
 924                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 925                 if (!ret2)
 926                         goto next_group;
 927
 928                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 929                         ext4_error(sb, "reserved inode found cleared - "
 930                                    "inode=%lu", ino + 1);
 931                         goto next_group;
 932                 }
 933
 934                 if (!handle) {
 935                         BUG_ON(nblocks <= 0);
 936                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
 937                                                          handle_type, nblocks,
 938                                                          0);
 939                         if (IS_ERR(handle)) {
 940                                 err = PTR_ERR(handle);
 941                                 ext4_std_error(sb, err);
 942                                 goto out;
 943                         }
 944                 }
 945                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
 946                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
 947                 if (err) {
 948                         ext4_std_error(sb, err);
 949                         goto out;
 950                 }
 951                 ext4_lock_group(sb, group);
 952                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
 953                 if (ret2) {
 954                         /* Someone already took the bit. Repeat the search
 955                          * with lock held.
 956                          */
 957                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 958                         if (ret2) {
 959                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
 960                                 ret2 = 0;
 961                         } else {
 962                                 ret2 = 1; /* we didn't grab the inode */
 963                         }
 964                 }
 965                 ext4_unlock_group(sb, group);
 966                 ino++;          /* the inode bitmap is zero-based */
 967                 if (!ret2)
 968                         goto got; /* we grabbed the inode! */
 969
 970                 if (ino < EXT4_INODES_PER_GROUP(sb))
 971                         goto repeat_in_this_group;
 972 next_group:
 973                 if (++group == ngroups)
 974                         group = 0;
 975         }
 976         err = -ENOSPC;
 977         goto out;
 978
 979 got:
 980         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 981         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
 982         if (err) {
 983                 ext4_std_error(sb, err);
 984                 goto out;
 985         }
 986
 987         BUFFER_TRACE(group_desc_bh, "get_write_access");
 988         err = ext4_journal_get_write_access(handle, group_desc_bh);
 989         if (err) {
 990                 ext4_std_error(sb, err);
 991                 goto out;
 992         }
 993
 994         /* We may have to initialize the block bitmap if it isn't already */
 995         if (ext4_has_group_desc_csum(sb) &&
 996             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 997                 struct buffer_head *block_bitmap_bh;
 998
 999                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1000                 if (IS_ERR(block_bitmap_bh)) {
1001                         err = PTR_ERR(block_bitmap_bh);
1002                         goto out;
1003                 }
1004                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1005                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1006                 if (err) {
1007                         brelse(block_bitmap_bh);
1008                         ext4_std_error(sb, err);
1009                         goto out;
1010                 }
1011
1012                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1013                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1014
1015                 /* recheck and clear flag under lock if we still need to */
1016                 ext4_lock_group(sb, group);
1017                 if (ext4_has_group_desc_csum(sb) &&
1018                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1019                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1020                         ext4_free_group_clusters_set(sb, gdp,
1021                                 ext4_free_clusters_after_init(sb, group, gdp));
1022                         ext4_block_bitmap_csum_set(sb, group, gdp,
1023                                                    block_bitmap_bh);
1024                         ext4_group_desc_csum_set(sb, group, gdp);
1025                 }
1026                 ext4_unlock_group(sb, group);
1027                 brelse(block_bitmap_bh);
1028
1029                 if (err) {
1030                         ext4_std_error(sb, err);
1031                         goto out;
1032                 }
1033         }
1034
1035         /* Update the relevant bg descriptor fields */
1036         if (ext4_has_group_desc_csum(sb)) {
1037                 int free;
1038                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1039
1040                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1041                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1042                 free = EXT4_INODES_PER_GROUP(sb) -
1043                         ext4_itable_unused_count(sb, gdp);
1044                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1045                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1046                         free = 0;
1047                 }
1048                 /*
1049                  * Check the relative inode number against the last used
1050                  * relative inode number in this group. if it is greater
1051                  * we need to update the bg_itable_unused count
1052                  */
1053                 if (ino > free)
1054                         ext4_itable_unused_set(sb, gdp,
1055                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1056                 up_read(&grp->alloc_sem);
1057         } else {
1058                 ext4_lock_group(sb, group);
1059         }
1060
1061         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1062         if (S_ISDIR(mode)) {
1063                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1064                 if (sbi->s_log_groups_per_flex) {
1065                         ext4_group_t f = ext4_flex_group(sbi, group);
1066
1067                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1068                                                         f)->used_dirs);
1069                 }
1070         }
1071         if (ext4_has_group_desc_csum(sb)) {
1072                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1073                                            EXT4_INODES_PER_GROUP(sb) / 8);
1074                 ext4_group_desc_csum_set(sb, group, gdp);
1075         }
1076         ext4_unlock_group(sb, group);
1077
1078         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1079         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1080         if (err) {
1081                 ext4_std_error(sb, err);
1082                 goto out;
1083         }
1084
1085         percpu_counter_dec(&sbi->s_freeinodes_counter);
1086         if (S_ISDIR(mode))
1087                 percpu_counter_inc(&sbi->s_dirs_counter);
1088
1089         if (sbi->s_log_groups_per_flex) {
1090                 flex_group = ext4_flex_group(sbi, group);
1091                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1092                                                 flex_group)->free_inodes);
1093         }
1094
1095         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1096         /* This is the optimal IO size (for stat), not the fs block size */
1097         inode->i_blocks = 0;
1098         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
1099                                                        current_time(inode);
1100
1101         memset(ei->i_data, 0, sizeof(ei->i_data));
1102         ei->i_dir_start_lookup = 0;
1103         ei->i_disksize = 0;
1104
1105         /* Don't inherit extent flag from directory, amongst others. */
1106         ei->i_flags =
1107                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1108         ei->i_flags |= i_flags;
1109         ei->i_file_acl = 0;
1110         ei->i_dtime = 0;
1111         ei->i_block_group = group;
1112         ei->i_last_alloc_group = ~0;
1113
1114         ext4_set_inode_flags(inode);
1115         if (IS_DIRSYNC(inode))
1116                 ext4_handle_sync(handle);
1117         if (insert_inode_locked(inode) < 0) {
1118                 /*
1119                  * Likely a bitmap corruption causing inode to be allocated
1120                  * twice.
1121                  */
1122                 err = -EIO;
1123                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1124                            inode->i_ino);
1125                 goto out;
1126         }
1127         spin_lock(&sbi->s_next_gen_lock);
1128         inode->i_generation = sbi->s_next_generation++;
1129         spin_unlock(&sbi->s_next_gen_lock);
1130
1131         /* Precompute checksum seed for inode metadata */
1132         if (ext4_has_metadata_csum(sb)) {
1133                 __u32 csum;
1134                 __le32 inum = cpu_to_le32(inode->i_ino);
1135                 __le32 gen = cpu_to_le32(inode->i_generation);
1136                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1137                                    sizeof(inum));
1138                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1139                                               sizeof(gen));
1140         }
1141
1142         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1143         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1144
1145         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
1146         ei->i_inline_off = 0;
1147         if (ext4_has_feature_inline_data(sb))
1148                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1149         ret = inode;
1150         err = dquot_alloc_inode(inode);
1151         if (err)
1152                 goto fail_drop;
1153
1154         /*
1155          * Since the encryption xattr will always be unique, create it first so
1156          * that it's less likely to end up in an external xattr block and
1157          * prevent its deduplication.
1158          */
1159         if (encrypt) {
1160                 err = fscrypt_inherit_context(dir, inode, handle, true);
1161                 if (err)
1162                         goto fail_free_drop;
1163         }
1164
1165         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1166                 err = ext4_init_acl(handle, inode, dir);
1167                 if (err)
1168                         goto fail_free_drop;
1169
1170                 err = ext4_init_security(handle, inode, dir, qstr);
1171                 if (err)
1172                         goto fail_free_drop;
1173         }
1174
1175         if (ext4_has_feature_extents(sb)) {
1176                 /* set extent flag only for directory, file and normal symlink*/
1177                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1178                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1179                         ext4_ext_tree_init(handle, inode);
1180                 }
1181         }
1182
1183         if (ext4_handle_valid(handle)) {
1184                 ei->i_sync_tid = handle->h_transaction->t_tid;
1185                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1186         }
1187
1188         err = ext4_mark_inode_dirty(handle, inode);
1189         if (err) {
1190                 ext4_std_error(sb, err);
1191                 goto fail_free_drop;
1192         }
1193
1194         ext4_debug("allocating inode %lu\n", inode->i_ino);
1195         trace_ext4_allocate_inode(inode, dir, mode);
1196         brelse(inode_bitmap_bh);
1197         return ret;
1198
1199 fail_free_drop:
1200         dquot_free_inode(inode);
1201 fail_drop:
1202         clear_nlink(inode);
1203         unlock_new_inode(inode);
1204 out:
1205         dquot_drop(inode);
1206         inode->i_flags |= S_NOQUOTA;
1207         iput(inode);
1208         brelse(inode_bitmap_bh);
1209         return ERR_PTR(err);
1210 }
1211
1212 /* Verify that we are loading a valid orphan from disk */
1213 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1214 {
1215         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1216         ext4_group_t block_group;
1217         int bit;
1218         struct buffer_head *bitmap_bh = NULL;
1219         struct inode *inode = NULL;
1220         int err = -EFSCORRUPTED;
1221
1222         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1223                 goto bad_orphan;
1224
1225         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1226         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1227         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1228         if (IS_ERR(bitmap_bh)) {
1229                 ext4_error(sb, "inode bitmap error %ld for orphan %lu",
1230                            ino, PTR_ERR(bitmap_bh));
1231                 return (struct inode *) bitmap_bh;
1232         }
1233
1234         /* Having the inode bit set should be a 100% indicator that this
1235          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1236          * inodes that were being truncated, so we can't check i_nlink==0.
1237          */
1238         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1239                 goto bad_orphan;
1240
1241         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1242         if (IS_ERR(inode)) {
1243                 err = PTR_ERR(inode);
1244                 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1245                            ino, err);
1246                 return inode;
1247         }
1248
1249         /*
1250          * If the orphans has i_nlinks > 0 then it should be able to
1251          * be truncated, otherwise it won't be removed from the orphan
1252          * list during processing and an infinite loop will result.
1253          * Similarly, it must not be a bad inode.
1254          */
1255         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1256             is_bad_inode(inode))
1257                 goto bad_orphan;
1258
1259         if (NEXT_ORPHAN(inode) > max_ino)
1260                 goto bad_orphan;
1261         brelse(bitmap_bh);
1262         return inode;
1263
1264 bad_orphan:
1265         ext4_error(sb, "bad orphan inode %lu", ino);
1266         if (bitmap_bh)
1267                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1268                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1269                        ext4_test_bit(bit, bitmap_bh->b_data));
1270         if (inode) {
1271                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1272                        is_bad_inode(inode));
1273                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1274                        NEXT_ORPHAN(inode));
1275                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1276                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1277                 /* Avoid freeing blocks if we got a bad deleted inode */
1278                 if (inode->i_nlink == 0)
1279                         inode->i_blocks = 0;
1280                 iput(inode);
1281         }
1282         brelse(bitmap_bh);
1283         return ERR_PTR(err);
1284 }
1285
1286 unsigned long ext4_count_free_inodes(struct super_block *sb)
1287 {
1288         unsigned long desc_count;
1289         struct ext4_group_desc *gdp;
1290         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1291 #ifdef EXT4FS_DEBUG
1292         struct ext4_super_block *es;
1293         unsigned long bitmap_count, x;
1294         struct buffer_head *bitmap_bh = NULL;
1295
1296         es = EXT4_SB(sb)->s_es;
1297         desc_count = 0;
1298         bitmap_count = 0;
1299         gdp = NULL;
1300         for (i = 0; i < ngroups; i++) {
1301                 gdp = ext4_get_group_desc(sb, i, NULL);
1302                 if (!gdp)
1303                         continue;
1304                 desc_count += ext4_free_inodes_count(sb, gdp);
1305                 brelse(bitmap_bh);
1306                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1307                 if (IS_ERR(bitmap_bh)) {
1308                         bitmap_bh = NULL;
1309                         continue;
1310                 }
1311
1312                 x = ext4_count_free(bitmap_bh->b_data,
1313                                     EXT4_INODES_PER_GROUP(sb) / 8);
1314                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1315                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1316                 bitmap_count += x;
1317         }
1318         brelse(bitmap_bh);
1319         printk(KERN_DEBUG "ext4_count_free_inodes: "
1320                "stored = %u, computed = %lu, %lu\n",
1321                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1322         return desc_count;
1323 #else
1324         desc_count = 0;
1325         for (i = 0; i < ngroups; i++) {
1326                 gdp = ext4_get_group_desc(sb, i, NULL);
1327                 if (!gdp)
1328                         continue;
1329                 desc_count += ext4_free_inodes_count(sb, gdp);
1330                 cond_resched();
1331         }
1332         return desc_count;
1333 #endif
1334 }
1335
1336 /* Called at mount-time, super-block is locked */
1337 unsigned long ext4_count_dirs(struct super_block * sb)
1338 {
1339         unsigned long count = 0;
1340         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1341
1342         for (i = 0; i < ngroups; i++) {
1343                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1344                 if (!gdp)
1345                         continue;
1346                 count += ext4_used_dirs_count(sb, gdp);
1347         }
1348         return count;
1349 }
1350
1351 /*
1352  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1353  * inode table. Must be called without any spinlock held. The only place
1354  * where it is called from on active part of filesystem is ext4lazyinit
1355  * thread, so we do not need any special locks, however we have to prevent
1356  * inode allocation from the current group, so we take alloc_sem lock, to
1357  * block ext4_new_inode() until we are finished.
1358  */
1359 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1360                                  int barrier)
1361 {
1362         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1363         struct ext4_sb_info *sbi = EXT4_SB(sb);
1364         struct ext4_group_desc *gdp = NULL;
1365         struct buffer_head *group_desc_bh;
1366         handle_t *handle;
1367         ext4_fsblk_t blk;
1368         int num, ret = 0, used_blks = 0;
1369         unsigned long used_inos = 0;
1370
1371         /* This should not happen, but just to be sure check this */
1372         if (sb_rdonly(sb)) {
1373                 ret = 1;
1374                 goto out;
1375         }
1376
1377         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1378         if (!gdp)
1379                 goto out;
1380
1381         /*
1382          * We do not need to lock this, because we are the only one
1383          * handling this flag.
1384          */
1385         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1386                 goto out;
1387
1388         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1389         if (IS_ERR(handle)) {
1390                 ret = PTR_ERR(handle);
1391                 goto out;
1392         }
1393
1394         down_write(&grp->alloc_sem);
1395         /*
1396          * If inode bitmap was already initialized there may be some
1397          * used inodes so we need to skip blocks with used inodes in
1398          * inode table.
1399          */
1400         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1401                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1402                             ext4_itable_unused_count(sb, gdp);
1403                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1404
1405                 /* Bogus inode unused count? */
1406                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1407                         ext4_error(sb, "Something is wrong with group %u: "
1408                                    "used itable blocks: %d; "
1409                                    "itable unused count: %u",
1410                                    group, used_blks,
1411                                    ext4_itable_unused_count(sb, gdp));
1412                         ret = 1;
1413                         goto err_out;
1414                 }
1415
1416                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1417                 /*
1418                  * Are there some uninitialized inodes in the inode table
1419                  * before the first normal inode?
1420                  */
1421                 if ((used_blks != sbi->s_itb_per_group) &&
1422                      (used_inos < EXT4_FIRST_INO(sb))) {
1423                         ext4_error(sb, "Something is wrong with group %u: "
1424                                    "itable unused count: %u; "
1425                                    "itables initialized count: %ld",
1426                                    group, ext4_itable_unused_count(sb, gdp),
1427                                    used_inos);
1428                         ret = 1;
1429                         goto err_out;
1430                 }
1431         }
1432
1433         blk = ext4_inode_table(sb, gdp) + used_blks;
1434         num = sbi->s_itb_per_group - used_blks;
1435
1436         BUFFER_TRACE(group_desc_bh, "get_write_access");
1437         ret = ext4_journal_get_write_access(handle,
1438                                             group_desc_bh);
1439         if (ret)
1440                 goto err_out;
1441
1442         /*
1443          * Skip zeroout if the inode table is full. But we set the ZEROED
1444          * flag anyway, because obviously, when it is full it does not need
1445          * further zeroing.
1446          */
1447         if (unlikely(num == 0))
1448                 goto skip_zeroout;
1449
1450         ext4_debug("going to zero out inode table in group %d\n",
1451                    group);
1452         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1453         if (ret < 0)
1454                 goto err_out;
1455         if (barrier)
1456                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1457
1458 skip_zeroout:
1459         ext4_lock_group(sb, group);
1460         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1461         ext4_group_desc_csum_set(sb, group, gdp);
1462         ext4_unlock_group(sb, group);
1463
1464         BUFFER_TRACE(group_desc_bh,
1465                      "call ext4_handle_dirty_metadata");
1466         ret = ext4_handle_dirty_metadata(handle, NULL,
1467                                          group_desc_bh);
1468
1469 err_out:
1470         up_write(&grp->alloc_sem);
1471         ext4_journal_stop(handle);
1472 out:
1473         return ret;
1474 }