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
  87         if (buffer_verified(bh))
  88                 return 0;
  89         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
  90                 return -EFSCORRUPTED;
  91
  92         ext4_lock_group(sb, block_group);
  93         if (buffer_verified(bh))
  94                 goto verified;
  95         blk = ext4_inode_bitmap(sb, desc);
  96         if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
  97                                            EXT4_INODES_PER_GROUP(sb) / 8)) {
  98                 ext4_unlock_group(sb, block_group);
  99                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 100                            "inode_bitmap = %llu", block_group, blk);
 101                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 102                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 103                 return -EFSBADCRC;
 104         }
 105         set_buffer_verified(bh);
 106 verified:
 107         ext4_unlock_group(sb, block_group);
 108         return 0;
 109 }
 110
 111 /*
 112  * Read the inode allocation bitmap for a given block_group, reading
 113  * into the specified slot in the superblock's bitmap cache.
 114  *
 115  * Return buffer_head of bitmap on success or NULL.
 116  */
 117 static struct buffer_head *
 118 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 119 {
 120         struct ext4_group_desc *desc;
 121         struct ext4_sb_info *sbi = EXT4_SB(sb);
 122         struct buffer_head *bh = NULL;
 123         ext4_fsblk_t bitmap_blk;
 124         int err;
 125
 126         desc = ext4_get_group_desc(sb, block_group, NULL);
 127         if (!desc)
 128                 return ERR_PTR(-EFSCORRUPTED);
 129
 130         bitmap_blk = ext4_inode_bitmap(sb, desc);
 131         if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
 132             (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
 133                 ext4_error(sb, "Invalid inode bitmap blk %llu in "
 134                            "block_group %u", bitmap_blk, block_group);
 135                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 136                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 137                 return ERR_PTR(-EFSCORRUPTED);
 138         }
 139         bh = sb_getblk(sb, bitmap_blk);
 140         if (unlikely(!bh)) {
 141                 ext4_warning(sb, "Cannot read inode bitmap - "
 142                              "block_group = %u, inode_bitmap = %llu",
 143                              block_group, bitmap_blk);
 144                 return ERR_PTR(-ENOMEM);
 145         }
 146         if (bitmap_uptodate(bh))
 147                 goto verify;
 148
 149         lock_buffer(bh);
 150         if (bitmap_uptodate(bh)) {
 151                 unlock_buffer(bh);
 152                 goto verify;
 153         }
 154
 155         ext4_lock_group(sb, block_group);
 156         if (ext4_has_group_desc_csum(sb) &&
 157             (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
 158                 if (block_group == 0) {
 159                         ext4_unlock_group(sb, block_group);
 160                         unlock_buffer(bh);
 161                         ext4_error(sb, "Inode bitmap for bg 0 marked "
 162                                    "uninitialized");
 163                         err = -EFSCORRUPTED;
 164                         goto out;
 165                 }
 166                 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
 167                 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
 168                                      sb->s_blocksize * 8, bh->b_data);
 169                 set_bitmap_uptodate(bh);
 170                 set_buffer_uptodate(bh);
 171                 set_buffer_verified(bh);
 172                 ext4_unlock_group(sb, block_group);
 173                 unlock_buffer(bh);
 174                 return bh;
 175         }
 176         ext4_unlock_group(sb, block_group);
 177
 178         if (buffer_uptodate(bh)) {
 179                 /*
 180                  * if not uninit if bh is uptodate,
 181                  * bitmap is also uptodate
 182                  */
 183                 set_bitmap_uptodate(bh);
 184                 unlock_buffer(bh);
 185                 goto verify;
 186         }
 187         /*
 188          * submit the buffer_head for reading
 189          */
 190         trace_ext4_load_inode_bitmap(sb, block_group);
 191         bh->b_end_io = ext4_end_bitmap_read;
 192         get_bh(bh);
 193         submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 194         wait_on_buffer(bh);
 195         if (!buffer_uptodate(bh)) {
 196                 put_bh(bh);
 197                 ext4_error(sb, "Cannot read inode bitmap - "
 198                            "block_group = %u, inode_bitmap = %llu",
 199                            block_group, bitmap_blk);
 200                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 201                                 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 202                 return ERR_PTR(-EIO);
 203         }
 204
 205 verify:
 206         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 207         if (err)
 208                 goto out;
 209         return bh;
 210 out:
 211         put_bh(bh);
 212         return ERR_PTR(err);
 213 }
 214
 215 /*
 216  * NOTE! When we get the inode, we're the only people
 217  * that have access to it, and as such there are no
 218  * race conditions we have to worry about. The inode
 219  * is not on the hash-lists, and it cannot be reached
 220  * through the filesystem because the directory entry
 221  * has been deleted earlier.
 222  *
 223  * HOWEVER: we must make sure that we get no aliases,
 224  * which means that we have to call "clear_inode()"
 225  * _before_ we mark the inode not in use in the inode
 226  * bitmaps. Otherwise a newly created file might use
 227  * the same inode number (not actually the same pointer
 228  * though), and then we'd have two inodes sharing the
 229  * same inode number and space on the harddisk.
 230  */
 231 void ext4_free_inode(handle_t *handle, struct inode *inode)
 232 {
 233         struct super_block *sb = inode->i_sb;
 234         int is_directory;
 235         unsigned long ino;
 236         struct buffer_head *bitmap_bh = NULL;
 237         struct buffer_head *bh2;
 238         ext4_group_t block_group;
 239         unsigned long bit;
 240         struct ext4_group_desc *gdp;
 241         struct ext4_super_block *es;
 242         struct ext4_sb_info *sbi;
 243         int fatal = 0, err, count, cleared;
 244         struct ext4_group_info *grp;
 245
 246         if (!sb) {
 247                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 248                        "nonexistent device\n", __func__, __LINE__);
 249                 return;
 250         }
 251         if (atomic_read(&inode->i_count) > 1) {
 252                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 253                          __func__, __LINE__, inode->i_ino,
 254                          atomic_read(&inode->i_count));
 255                 return;
 256         }
 257         if (inode->i_nlink) {
 258                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 259                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 260                 return;
 261         }
 262         sbi = EXT4_SB(sb);
 263
 264         ino = inode->i_ino;
 265         ext4_debug("freeing inode %lu\n", ino);
 266         trace_ext4_free_inode(inode);
 267
 268         /*
 269          * Note: we must free any quota before locking the superblock,
 270          * as writing the quota to disk may need the lock as well.
 271          */
 272         dquot_initialize(inode);
 273         dquot_free_inode(inode);
 274         dquot_drop(inode);
 275
 276         is_directory = S_ISDIR(inode->i_mode);
 277
 278         /* Do this BEFORE marking the inode not in use or returning an error */
 279         ext4_clear_inode(inode);
 280
 281         es = sbi->s_es;
 282         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 283                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 284                 goto error_return;
 285         }
 286         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 287         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 288         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 289         /* Don't bother if the inode bitmap is corrupt. */
 290         grp = ext4_get_group_info(sb, block_group);
 291         if (IS_ERR(bitmap_bh)) {
 292                 fatal = PTR_ERR(bitmap_bh);
 293                 bitmap_bh = NULL;
 294                 goto error_return;
 295         }
 296         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 297                 fatal = -EFSCORRUPTED;
 298                 goto error_return;
 299         }
 300
 301         BUFFER_TRACE(bitmap_bh, "get_write_access");
 302         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 303         if (fatal)
 304                 goto error_return;
 305
 306         fatal = -ESRCH;
 307         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 308         if (gdp) {
 309                 BUFFER_TRACE(bh2, "get_write_access");
 310                 fatal = ext4_journal_get_write_access(handle, bh2);
 311         }
 312         ext4_lock_group(sb, block_group);
 313         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 314         if (fatal || !cleared) {
 315                 ext4_unlock_group(sb, block_group);
 316                 goto out;
 317         }
 318
 319         count = ext4_free_inodes_count(sb, gdp) + 1;
 320         ext4_free_inodes_set(sb, gdp, count);
 321         if (is_directory) {
 322                 count = ext4_used_dirs_count(sb, gdp) - 1;
 323                 ext4_used_dirs_set(sb, gdp, count);
 324                 percpu_counter_dec(&sbi->s_dirs_counter);
 325         }
 326         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 327                                    EXT4_INODES_PER_GROUP(sb) / 8);
 328         ext4_group_desc_csum_set(sb, block_group, gdp);
 329         ext4_unlock_group(sb, block_group);
 330
 331         percpu_counter_inc(&sbi->s_freeinodes_counter);
 332         if (sbi->s_log_groups_per_flex) {
 333                 struct flex_groups *fg;
 334
 335                 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
 336                                          ext4_flex_group(sbi, block_group));
 337                 atomic_inc(&fg->free_inodes);
 338                 if (is_directory)
 339                         atomic_dec(&fg->used_dirs);
 340         }
 341         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
 342         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
 343 out:
 344         if (cleared) {
 345                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
 346                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 347                 if (!fatal)
 348                         fatal = err;
 349         } else {
 350                 ext4_error(sb, "bit already cleared for inode %lu", ino);
 351                 ext4_mark_group_bitmap_corrupted(sb, block_group,
 352                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 353         }
 354
 355 error_return:
 356         brelse(bitmap_bh);
 357         ext4_std_error(sb, fatal);
 358 }
 359
 360 struct orlov_stats {
 361         __u64 free_clusters;
 362         __u32 free_inodes;
 363         __u32 used_dirs;
 364 };
 365
 366 /*
 367  * Helper function for Orlov's allocator; returns critical information
 368  * for a particular block group or flex_bg.  If flex_size is 1, then g
 369  * is a block group number; otherwise it is flex_bg number.
 370  */
 371 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 372                             int flex_size, struct orlov_stats *stats)
 373 {
 374         struct ext4_group_desc *desc;
 375
 376         if (flex_size > 1) {
 377                 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
 378                                                              s_flex_groups, g);
 379                 stats->free_inodes = atomic_read(&fg->free_inodes);
 380                 stats->free_clusters = atomic64_read(&fg->free_clusters);
 381                 stats->used_dirs = atomic_read(&fg->used_dirs);
 382                 return;
 383         }
 384
 385         desc = ext4_get_group_desc(sb, g, NULL);
 386         if (desc) {
 387                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 388                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 389                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 390         } else {
 391                 stats->free_inodes = 0;
 392                 stats->free_clusters = 0;
 393                 stats->used_dirs = 0;
 394         }
 395 }
 396
 397 /*
 398  * Orlov's allocator for directories.
 399  *
 400  * We always try to spread first-level directories.
 401  *
 402  * If there are blockgroups with both free inodes and free clusters counts
 403  * not worse than average we return one with smallest directory count.
 404  * Otherwise we simply return a random group.
 405  *
 406  * For the rest rules look so:
 407  *
 408  * It's OK to put directory into a group unless
 409  * it has too many directories already (max_dirs) or
 410  * it has too few free inodes left (min_inodes) or
 411  * it has too few free clusters left (min_clusters) or
 412  * Parent's group is preferred, if it doesn't satisfy these
 413  * conditions we search cyclically through the rest. If none
 414  * of the groups look good we just look for a group with more
 415  * free inodes than average (starting at parent's group).
 416  */
 417
 418 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 419                             ext4_group_t *group, umode_t mode,
 420                             const struct qstr *qstr)
 421 {
 422         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 423         struct ext4_sb_info *sbi = EXT4_SB(sb);
 424         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 425         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 426         unsigned int freei, avefreei, grp_free;
 427         ext4_fsblk_t freec, avefreec;
 428         unsigned int ndirs;
 429         int max_dirs, min_inodes;
 430         ext4_grpblk_t min_clusters;
 431         ext4_group_t i, grp, g, ngroups;
 432         struct ext4_group_desc *desc;
 433         struct orlov_stats stats;
 434         int flex_size = ext4_flex_bg_size(sbi);
 435         struct dx_hash_info hinfo;
 436
 437         ngroups = real_ngroups;
 438         if (flex_size > 1) {
 439                 ngroups = (real_ngroups + flex_size - 1) >>
 440                         sbi->s_log_groups_per_flex;
 441                 parent_group >>= sbi->s_log_groups_per_flex;
 442         }
 443
 444         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 445         avefreei = freei / ngroups;
 446         freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
 447         avefreec = freec;
 448         do_div(avefreec, ngroups);
 449         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 450
 451         if (S_ISDIR(mode) &&
 452             ((parent == d_inode(sb->s_root)) ||
 453              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 454                 int best_ndir = inodes_per_group;
 455                 int ret = -1;
 456
 457                 if (qstr) {
 458                         hinfo.hash_version = DX_HASH_HALF_MD4;
 459                         hinfo.seed = sbi->s_hash_seed;
 460                         ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
 461                         grp = hinfo.hash;
 462                 } else
 463                         grp = prandom_u32();
 464                 parent_group = (unsigned)grp % ngroups;
 465                 for (i = 0; i < ngroups; i++) {
 466                         g = (parent_group + i) % ngroups;
 467                         get_orlov_stats(sb, g, flex_size, &stats);
 468                         if (!stats.free_inodes)
 469                                 continue;
 470                         if (stats.used_dirs >= best_ndir)
 471                                 continue;
 472                         if (stats.free_inodes < avefreei)
 473                                 continue;
 474                         if (stats.free_clusters < avefreec)
 475                                 continue;
 476                         grp = g;
 477                         ret = 0;
 478                         best_ndir = stats.used_dirs;
 479                 }
 480                 if (ret)
 481                         goto fallback;
 482         found_flex_bg:
 483                 if (flex_size == 1) {
 484                         *group = grp;
 485                         return 0;
 486                 }
 487
 488                 /*
 489                  * We pack inodes at the beginning of the flexgroup's
 490                  * inode tables.  Block allocation decisions will do
 491                  * something similar, although regular files will
 492                  * start at 2nd block group of the flexgroup.  See
 493                  * ext4_ext_find_goal() and ext4_find_near().
 494                  */
 495                 grp *= flex_size;
 496                 for (i = 0; i < flex_size; i++) {
 497                         if (grp+i >= real_ngroups)
 498                                 break;
 499                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 500                         if (desc && ext4_free_inodes_count(sb, desc)) {
 501                                 *group = grp+i;
 502                                 return 0;
 503                         }
 504                 }
 505                 goto fallback;
 506         }
 507
 508         max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
 509         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 510         if (min_inodes < 1)
 511                 min_inodes = 1;
 512         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 513
 514         /*
 515          * Start looking in the flex group where we last allocated an
 516          * inode for this parent directory
 517          */
 518         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 519                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 520                 if (flex_size > 1)
 521                         parent_group >>= sbi->s_log_groups_per_flex;
 522         }
 523
 524         for (i = 0; i < ngroups; i++) {
 525                 grp = (parent_group + i) % ngroups;
 526                 get_orlov_stats(sb, grp, flex_size, &stats);
 527                 if (stats.used_dirs >= max_dirs)
 528                         continue;
 529                 if (stats.free_inodes < min_inodes)
 530                         continue;
 531                 if (stats.free_clusters < min_clusters)
 532                         continue;
 533                 goto found_flex_bg;
 534         }
 535
 536 fallback:
 537         ngroups = real_ngroups;
 538         avefreei = freei / ngroups;
 539 fallback_retry:
 540         parent_group = EXT4_I(parent)->i_block_group;
 541         for (i = 0; i < ngroups; i++) {
 542                 grp = (parent_group + i) % ngroups;
 543                 desc = ext4_get_group_desc(sb, grp, NULL);
 544                 if (desc) {
 545                         grp_free = ext4_free_inodes_count(sb, desc);
 546                         if (grp_free && grp_free >= avefreei) {
 547                                 *group = grp;
 548                                 return 0;
 549                         }
 550                 }
 551         }
 552
 553         if (avefreei) {
 554                 /*
 555                  * The free-inodes counter is approximate, and for really small
 556                  * filesystems the above test can fail to find any blockgroups
 557                  */
 558                 avefreei = 0;
 559                 goto fallback_retry;
 560         }
 561
 562         return -1;
 563 }
 564
 565 static int find_group_other(struct super_block *sb, struct inode *parent,
 566                             ext4_group_t *group, umode_t mode)
 567 {
 568         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 569         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 570         struct ext4_group_desc *desc;
 571         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 572
 573         /*
 574          * Try to place the inode is the same flex group as its
 575          * parent.  If we can't find space, use the Orlov algorithm to
 576          * find another flex group, and store that information in the
 577          * parent directory's inode information so that use that flex
 578          * group for future allocations.
 579          */
 580         if (flex_size > 1) {
 581                 int retry = 0;
 582
 583         try_again:
 584                 parent_group &= ~(flex_size-1);
 585                 last = parent_group + flex_size;
 586                 if (last > ngroups)
 587                         last = ngroups;
 588                 for  (i = parent_group; i < last; i++) {
 589                         desc = ext4_get_group_desc(sb, i, NULL);
 590                         if (desc && ext4_free_inodes_count(sb, desc)) {
 591                                 *group = i;
 592                                 return 0;
 593                         }
 594                 }
 595                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 596                         retry = 1;
 597                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 598                         goto try_again;
 599                 }
 600                 /*
 601                  * If this didn't work, use the Orlov search algorithm
 602                  * to find a new flex group; we pass in the mode to
 603                  * avoid the topdir algorithms.
 604                  */
 605                 *group = parent_group + flex_size;
 606                 if (*group > ngroups)
 607                         *group = 0;
 608                 return find_group_orlov(sb, parent, group, mode, NULL);
 609         }
 610
 611         /*
 612          * Try to place the inode in its parent directory
 613          */
 614         *group = parent_group;
 615         desc = ext4_get_group_desc(sb, *group, NULL);
 616         if (desc && ext4_free_inodes_count(sb, desc) &&
 617             ext4_free_group_clusters(sb, desc))
 618                 return 0;
 619
 620         /*
 621          * We're going to place this inode in a different blockgroup from its
 622          * parent.  We want to cause files in a common directory to all land in
 623          * the same blockgroup.  But we want files which are in a different
 624          * directory which shares a blockgroup with our parent to land in a
 625          * different blockgroup.
 626          *
 627          * So add our directory's i_ino into the starting point for the hash.
 628          */
 629         *group = (*group + parent->i_ino) % ngroups;
 630
 631         /*
 632          * Use a quadratic hash to find a group with a free inode and some free
 633          * blocks.
 634          */
 635         for (i = 1; i < ngroups; i <<= 1) {
 636                 *group += i;
 637                 if (*group >= ngroups)
 638                         *group -= ngroups;
 639                 desc = ext4_get_group_desc(sb, *group, NULL);
 640                 if (desc && ext4_free_inodes_count(sb, desc) &&
 641                     ext4_free_group_clusters(sb, desc))
 642                         return 0;
 643         }
 644
 645         /*
 646          * That failed: try linear search for a free inode, even if that group
 647          * has no free blocks.
 648          */
 649         *group = parent_group;
 650         for (i = 0; i < ngroups; i++) {
 651                 if (++*group >= ngroups)
 652                         *group = 0;
 653                 desc = ext4_get_group_desc(sb, *group, NULL);
 654                 if (desc && ext4_free_inodes_count(sb, desc))
 655                         return 0;
 656         }
 657
 658         return -1;
 659 }
 660
 661 /*
 662  * In no journal mode, if an inode has recently been deleted, we want
 663  * to avoid reusing it until we're reasonably sure the inode table
 664  * block has been written back to disk.  (Yes, these values are
 665  * somewhat arbitrary...)
 666  */
 667 #define RECENTCY_MIN    60
 668 #define RECENTCY_DIRTY  300
 669
 670 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 671 {
 672         struct ext4_group_desc  *gdp;
 673         struct ext4_inode       *raw_inode;
 674         struct buffer_head      *bh;
 675         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 676         int offset, ret = 0;
 677         int recentcy = RECENTCY_MIN;
 678         u32 dtime, now;
 679
 680         gdp = ext4_get_group_desc(sb, group, NULL);
 681         if (unlikely(!gdp))
 682                 return 0;
 683
 684         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 685                        (ino / inodes_per_block));
 686         if (!bh || !buffer_uptodate(bh))
 687                 /*
 688                  * If the block is not in the buffer cache, then it
 689                  * must have been written out.
 690                  */
 691                 goto out;
 692
 693         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 694         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 695
 696         /* i_dtime is only 32 bits on disk, but we only care about relative
 697          * times in the range of a few minutes (i.e. long enough to sync a
 698          * recently-deleted inode to disk), so using the low 32 bits of the
 699          * clock (a 68 year range) is enough, see time_before32() */
 700         dtime = le32_to_cpu(raw_inode->i_dtime);
 701         now = ktime_get_real_seconds();
 702         if (buffer_dirty(bh))
 703                 recentcy += RECENTCY_DIRTY;
 704
 705         if (dtime && time_before32(dtime, now) &&
 706             time_before32(now, dtime + recentcy))
 707                 ret = 1;
 708 out:
 709         brelse(bh);
 710         return ret;
 711 }
 712
 713 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 714                           struct buffer_head *bitmap, unsigned long *ino)
 715 {
 716 next:
 717         *ino = ext4_find_next_zero_bit((unsigned long *)
 718                                        bitmap->b_data,
 719                                        EXT4_INODES_PER_GROUP(sb), *ino);
 720         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 721                 return 0;
 722
 723         if ((EXT4_SB(sb)->s_journal == NULL) &&
 724             recently_deleted(sb, group, *ino)) {
 725                 *ino = *ino + 1;
 726                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 727                         goto next;
 728                 return 0;
 729         }
 730
 731         return 1;
 732 }
 733
 734 /*
 735  * There are two policies for allocating an inode.  If the new inode is
 736  * a directory, then a forward search is made for a block group with both
 737  * free space and a low directory-to-inode ratio; if that fails, then of
 738  * the groups with above-average free space, that group with the fewest
 739  * directories already is chosen.
 740  *
 741  * For other inodes, search forward from the parent directory's block
 742  * group to find a free inode.
 743  */
 744 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 745                                umode_t mode, const struct qstr *qstr,
 746                                __u32 goal, uid_t *owner, __u32 i_flags,
 747                                int handle_type, unsigned int line_no,
 748                                int nblocks)
 749 {
 750         struct super_block *sb;
 751         struct buffer_head *inode_bitmap_bh = NULL;
 752         struct buffer_head *group_desc_bh;
 753         ext4_group_t ngroups, group = 0;
 754         unsigned long ino = 0;
 755         struct inode *inode;
 756         struct ext4_group_desc *gdp = NULL;
 757         struct ext4_inode_info *ei;
 758         struct ext4_sb_info *sbi;
 759         int ret2, err;
 760         struct inode *ret;
 761         ext4_group_t i;
 762         ext4_group_t flex_group;
 763         struct ext4_group_info *grp;
 764         int encrypt = 0;
 765
 766         /* Cannot create files in a deleted directory */
 767         if (!dir || !dir->i_nlink)
 768                 return ERR_PTR(-EPERM);
 769
 770         sb = dir->i_sb;
 771         sbi = EXT4_SB(sb);
 772
 773         if (unlikely(ext4_forced_shutdown(sbi)))
 774                 return ERR_PTR(-EIO);
 775
 776         if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
 777             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
 778             !(i_flags & EXT4_EA_INODE_FL)) {
 779                 err = fscrypt_get_encryption_info(dir);
 780                 if (err)
 781                         return ERR_PTR(err);
 782                 if (!fscrypt_has_encryption_key(dir))
 783                         return ERR_PTR(-ENOKEY);
 784                 encrypt = 1;
 785         }
 786
 787         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 788 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 789                 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 790
 791                 if (IS_ERR(p))
 792                         return ERR_CAST(p);
 793                 if (p) {
 794                         int acl_size = p->a_count * sizeof(ext4_acl_entry);
 795
 796                         nblocks += (S_ISDIR(mode) ? 2 : 1) *
 797                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 798                                         NULL /* block_bh */, acl_size,
 799                                         true /* is_create */);
 800                         posix_acl_release(p);
 801                 }
 802 #endif
 803
 804 #ifdef CONFIG_SECURITY
 805                 {
 806                         int num_security_xattrs = 1;
 807
 808 #ifdef CONFIG_INTEGRITY
 809                         num_security_xattrs++;
 810 #endif
 811                         /*
 812                          * We assume that security xattrs are never
 813                          * more than 1k.  In practice they are under
 814                          * 128 bytes.
 815                          */
 816                         nblocks += num_security_xattrs *
 817                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 818                                         NULL /* block_bh */, 1024,
 819                                         true /* is_create */);
 820                 }
 821 #endif
 822                 if (encrypt)
 823                         nblocks += __ext4_xattr_set_credits(sb,
 824                                         NULL /* inode */, NULL /* block_bh */,
 825                                         FSCRYPT_SET_CONTEXT_MAX_SIZE,
 826                                         true /* is_create */);
 827         }
 828
 829         ngroups = ext4_get_groups_count(sb);
 830         trace_ext4_request_inode(dir, mode);
 831         inode = new_inode(sb);
 832         if (!inode)
 833                 return ERR_PTR(-ENOMEM);
 834         ei = EXT4_I(inode);
 835
 836         /*
 837          * Initialize owners and quota early so that we don't have to account
 838          * for quota initialization worst case in standard inode creating
 839          * transaction
 840          */
 841         if (owner) {
 842                 inode->i_mode = mode;
 843                 i_uid_write(inode, owner[0]);
 844                 i_gid_write(inode, owner[1]);
 845         } else if (test_opt(sb, GRPID)) {
 846                 inode->i_mode = mode;
 847                 inode->i_uid = current_fsuid();
 848                 inode->i_gid = dir->i_gid;
 849         } else
 850                 inode_init_owner(inode, dir, mode);
 851
 852         if (ext4_has_feature_project(sb) &&
 853             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 854                 ei->i_projid = EXT4_I(dir)->i_projid;
 855         else
 856                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 857
 858         err = dquot_initialize(inode);
 859         if (err)
 860                 goto out;
 861
 862         if (!goal)
 863                 goal = sbi->s_inode_goal;
 864
 865         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
 866                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
 867                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
 868                 ret2 = 0;
 869                 goto got_group;
 870         }
 871
 872         if (S_ISDIR(mode))
 873                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
 874         else
 875                 ret2 = find_group_other(sb, dir, &group, mode);
 876
 877 got_group:
 878         EXT4_I(dir)->i_last_alloc_group = group;
 879         err = -ENOSPC;
 880         if (ret2 == -1)
 881                 goto out;
 882
 883         /*
 884          * Normally we will only go through one pass of this loop,
 885          * unless we get unlucky and it turns out the group we selected
 886          * had its last inode grabbed by someone else.
 887          */
 888         for (i = 0; i < ngroups; i++, ino = 0) {
 889                 err = -EIO;
 890
 891                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 892                 if (!gdp)
 893                         goto out;
 894
 895                 /*
 896                  * Check free inodes count before loading bitmap.
 897                  */
 898                 if (ext4_free_inodes_count(sb, gdp) == 0)
 899                         goto next_group;
 900
 901                 grp = ext4_get_group_info(sb, group);
 902                 /* Skip groups with already-known suspicious inode tables */
 903                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 904                         goto next_group;
 905
 906                 brelse(inode_bitmap_bh);
 907                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 908                 /* Skip groups with suspicious inode tables */
 909                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 910                     IS_ERR(inode_bitmap_bh)) {
 911                         inode_bitmap_bh = NULL;
 912                         goto next_group;
 913                 }
 914
 915 repeat_in_this_group:
 916                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 917                 if (!ret2)
 918                         goto next_group;
 919
 920                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 921                         ext4_error(sb, "reserved inode found cleared - "
 922                                    "inode=%lu", ino + 1);
 923                         ext4_mark_group_bitmap_corrupted(sb, group,
 924                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
 925                         goto next_group;
 926                 }
 927
 928                 if (!handle) {
 929                         BUG_ON(nblocks <= 0);
 930                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
 931                                                          handle_type, nblocks,
 932                                                          0);
 933                         if (IS_ERR(handle)) {
 934                                 err = PTR_ERR(handle);
 935                                 ext4_std_error(sb, err);
 936                                 goto out;
 937                         }
 938                 }
 939                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
 940                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
 941                 if (err) {
 942                         ext4_std_error(sb, err);
 943                         goto out;
 944                 }
 945                 ext4_lock_group(sb, group);
 946                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
 947                 if (ret2) {
 948                         /* Someone already took the bit. Repeat the search
 949                          * with lock held.
 950                          */
 951                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 952                         if (ret2) {
 953                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
 954                                 ret2 = 0;
 955                         } else {
 956                                 ret2 = 1; /* we didn't grab the inode */
 957                         }
 958                 }
 959                 ext4_unlock_group(sb, group);
 960                 ino++;          /* the inode bitmap is zero-based */
 961                 if (!ret2)
 962                         goto got; /* we grabbed the inode! */
 963
 964                 if (ino < EXT4_INODES_PER_GROUP(sb))
 965                         goto repeat_in_this_group;
 966 next_group:
 967                 if (++group == ngroups)
 968                         group = 0;
 969         }
 970         err = -ENOSPC;
 971         goto out;
 972
 973 got:
 974         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
 975         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
 976         if (err) {
 977                 ext4_std_error(sb, err);
 978                 goto out;
 979         }
 980
 981         BUFFER_TRACE(group_desc_bh, "get_write_access");
 982         err = ext4_journal_get_write_access(handle, group_desc_bh);
 983         if (err) {
 984                 ext4_std_error(sb, err);
 985                 goto out;
 986         }
 987
 988         /* We may have to initialize the block bitmap if it isn't already */
 989         if (ext4_has_group_desc_csum(sb) &&
 990             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
 991                 struct buffer_head *block_bitmap_bh;
 992
 993                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
 994                 if (IS_ERR(block_bitmap_bh)) {
 995                         err = PTR_ERR(block_bitmap_bh);
 996                         goto out;
 997                 }
 998                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
 999                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1000                 if (err) {
1001                         brelse(block_bitmap_bh);
1002                         ext4_std_error(sb, err);
1003                         goto out;
1004                 }
1005
1006                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1007                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1008
1009                 /* recheck and clear flag under lock if we still need to */
1010                 ext4_lock_group(sb, group);
1011                 if (ext4_has_group_desc_csum(sb) &&
1012                     (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1013                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1014                         ext4_free_group_clusters_set(sb, gdp,
1015                                 ext4_free_clusters_after_init(sb, group, gdp));
1016                         ext4_block_bitmap_csum_set(sb, group, gdp,
1017                                                    block_bitmap_bh);
1018                         ext4_group_desc_csum_set(sb, group, gdp);
1019                 }
1020                 ext4_unlock_group(sb, group);
1021                 brelse(block_bitmap_bh);
1022
1023                 if (err) {
1024                         ext4_std_error(sb, err);
1025                         goto out;
1026                 }
1027         }
1028
1029         /* Update the relevant bg descriptor fields */
1030         if (ext4_has_group_desc_csum(sb)) {
1031                 int free;
1032                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1033
1034                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1035                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1036                 free = EXT4_INODES_PER_GROUP(sb) -
1037                         ext4_itable_unused_count(sb, gdp);
1038                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1039                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1040                         free = 0;
1041                 }
1042                 /*
1043                  * Check the relative inode number against the last used
1044                  * relative inode number in this group. if it is greater
1045                  * we need to update the bg_itable_unused count
1046                  */
1047                 if (ino > free)
1048                         ext4_itable_unused_set(sb, gdp,
1049                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1050                 up_read(&grp->alloc_sem);
1051         } else {
1052                 ext4_lock_group(sb, group);
1053         }
1054
1055         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1056         if (S_ISDIR(mode)) {
1057                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1058                 if (sbi->s_log_groups_per_flex) {
1059                         ext4_group_t f = ext4_flex_group(sbi, group);
1060
1061                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1062                                                         f)->used_dirs);
1063                 }
1064         }
1065         if (ext4_has_group_desc_csum(sb)) {
1066                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1067                                            EXT4_INODES_PER_GROUP(sb) / 8);
1068                 ext4_group_desc_csum_set(sb, group, gdp);
1069         }
1070         ext4_unlock_group(sb, group);
1071
1072         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1073         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1074         if (err) {
1075                 ext4_std_error(sb, err);
1076                 goto out;
1077         }
1078
1079         percpu_counter_dec(&sbi->s_freeinodes_counter);
1080         if (S_ISDIR(mode))
1081                 percpu_counter_inc(&sbi->s_dirs_counter);
1082
1083         if (sbi->s_log_groups_per_flex) {
1084                 flex_group = ext4_flex_group(sbi, group);
1085                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1086                                                 flex_group)->free_inodes);
1087         }
1088
1089         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1090         /* This is the optimal IO size (for stat), not the fs block size */
1091         inode->i_blocks = 0;
1092         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1093         ei->i_crtime = inode->i_mtime;
1094
1095         memset(ei->i_data, 0, sizeof(ei->i_data));
1096         ei->i_dir_start_lookup = 0;
1097         ei->i_disksize = 0;
1098
1099         /* Don't inherit extent flag from directory, amongst others. */
1100         ei->i_flags =
1101                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1102         ei->i_flags |= i_flags;
1103         ei->i_file_acl = 0;
1104         ei->i_dtime = 0;
1105         ei->i_block_group = group;
1106         ei->i_last_alloc_group = ~0;
1107
1108         ext4_set_inode_flags(inode);
1109         if (IS_DIRSYNC(inode))
1110                 ext4_handle_sync(handle);
1111         if (insert_inode_locked(inode) < 0) {
1112                 /*
1113                  * Likely a bitmap corruption causing inode to be allocated
1114                  * twice.
1115                  */
1116                 err = -EIO;
1117                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1118                            inode->i_ino);
1119                 ext4_mark_group_bitmap_corrupted(sb, group,
1120                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1121                 goto out;
1122         }
1123         inode->i_generation = prandom_u32();
1124
1125         /* Precompute checksum seed for inode metadata */
1126         if (ext4_has_metadata_csum(sb)) {
1127                 __u32 csum;
1128                 __le32 inum = cpu_to_le32(inode->i_ino);
1129                 __le32 gen = cpu_to_le32(inode->i_generation);
1130                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1131                                    sizeof(inum));
1132                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1133                                               sizeof(gen));
1134         }
1135
1136         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1137         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1138
1139         ei->i_extra_isize = sbi->s_want_extra_isize;
1140         ei->i_inline_off = 0;
1141         if (ext4_has_feature_inline_data(sb))
1142                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1143         ret = inode;
1144         err = dquot_alloc_inode(inode);
1145         if (err)
1146                 goto fail_drop;
1147
1148         /*
1149          * Since the encryption xattr will always be unique, create it first so
1150          * that it's less likely to end up in an external xattr block and
1151          * prevent its deduplication.
1152          */
1153         if (encrypt) {
1154                 err = fscrypt_inherit_context(dir, inode, handle, true);
1155                 if (err)
1156                         goto fail_free_drop;
1157         }
1158
1159         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1160                 err = ext4_init_acl(handle, inode, dir);
1161                 if (err)
1162                         goto fail_free_drop;
1163
1164                 err = ext4_init_security(handle, inode, dir, qstr);
1165                 if (err)
1166                         goto fail_free_drop;
1167         }
1168
1169         if (ext4_has_feature_extents(sb)) {
1170                 /* set extent flag only for directory, file and normal symlink*/
1171                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1172                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1173                         ext4_ext_tree_init(handle, inode);
1174                 }
1175         }
1176
1177         if (ext4_handle_valid(handle)) {
1178                 ei->i_sync_tid = handle->h_transaction->t_tid;
1179                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1180         }
1181
1182         err = ext4_mark_inode_dirty(handle, inode);
1183         if (err) {
1184                 ext4_std_error(sb, err);
1185                 goto fail_free_drop;
1186         }
1187
1188         ext4_debug("allocating inode %lu\n", inode->i_ino);
1189         trace_ext4_allocate_inode(inode, dir, mode);
1190         brelse(inode_bitmap_bh);
1191         return ret;
1192
1193 fail_free_drop:
1194         dquot_free_inode(inode);
1195 fail_drop:
1196         clear_nlink(inode);
1197         unlock_new_inode(inode);
1198 out:
1199         dquot_drop(inode);
1200         inode->i_flags |= S_NOQUOTA;
1201         iput(inode);
1202         brelse(inode_bitmap_bh);
1203         return ERR_PTR(err);
1204 }
1205
1206 /* Verify that we are loading a valid orphan from disk */
1207 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1208 {
1209         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1210         ext4_group_t block_group;
1211         int bit;
1212         struct buffer_head *bitmap_bh = NULL;
1213         struct inode *inode = NULL;
1214         int err = -EFSCORRUPTED;
1215
1216         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1217                 goto bad_orphan;
1218
1219         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1220         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1221         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1222         if (IS_ERR(bitmap_bh))
1223                 return (struct inode *) bitmap_bh;
1224
1225         /* Having the inode bit set should be a 100% indicator that this
1226          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1227          * inodes that were being truncated, so we can't check i_nlink==0.
1228          */
1229         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1230                 goto bad_orphan;
1231
1232         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1233         if (IS_ERR(inode)) {
1234                 err = PTR_ERR(inode);
1235                 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1236                            ino, err);
1237                 return inode;
1238         }
1239
1240         /*
1241          * If the orphans has i_nlinks > 0 then it should be able to
1242          * be truncated, otherwise it won't be removed from the orphan
1243          * list during processing and an infinite loop will result.
1244          * Similarly, it must not be a bad inode.
1245          */
1246         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1247             is_bad_inode(inode))
1248                 goto bad_orphan;
1249
1250         if (NEXT_ORPHAN(inode) > max_ino)
1251                 goto bad_orphan;
1252         brelse(bitmap_bh);
1253         return inode;
1254
1255 bad_orphan:
1256         ext4_error(sb, "bad orphan inode %lu", ino);
1257         if (bitmap_bh)
1258                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1259                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1260                        ext4_test_bit(bit, bitmap_bh->b_data));
1261         if (inode) {
1262                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1263                        is_bad_inode(inode));
1264                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1265                        NEXT_ORPHAN(inode));
1266                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1267                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1268                 /* Avoid freeing blocks if we got a bad deleted inode */
1269                 if (inode->i_nlink == 0)
1270                         inode->i_blocks = 0;
1271                 iput(inode);
1272         }
1273         brelse(bitmap_bh);
1274         return ERR_PTR(err);
1275 }
1276
1277 unsigned long ext4_count_free_inodes(struct super_block *sb)
1278 {
1279         unsigned long desc_count;
1280         struct ext4_group_desc *gdp;
1281         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1282 #ifdef EXT4FS_DEBUG
1283         struct ext4_super_block *es;
1284         unsigned long bitmap_count, x;
1285         struct buffer_head *bitmap_bh = NULL;
1286
1287         es = EXT4_SB(sb)->s_es;
1288         desc_count = 0;
1289         bitmap_count = 0;
1290         gdp = NULL;
1291         for (i = 0; i < ngroups; i++) {
1292                 gdp = ext4_get_group_desc(sb, i, NULL);
1293                 if (!gdp)
1294                         continue;
1295                 desc_count += ext4_free_inodes_count(sb, gdp);
1296                 brelse(bitmap_bh);
1297                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1298                 if (IS_ERR(bitmap_bh)) {
1299                         bitmap_bh = NULL;
1300                         continue;
1301                 }
1302
1303                 x = ext4_count_free(bitmap_bh->b_data,
1304                                     EXT4_INODES_PER_GROUP(sb) / 8);
1305                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1306                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1307                 bitmap_count += x;
1308         }
1309         brelse(bitmap_bh);
1310         printk(KERN_DEBUG "ext4_count_free_inodes: "
1311                "stored = %u, computed = %lu, %lu\n",
1312                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1313         return desc_count;
1314 #else
1315         desc_count = 0;
1316         for (i = 0; i < ngroups; i++) {
1317                 gdp = ext4_get_group_desc(sb, i, NULL);
1318                 if (!gdp)
1319                         continue;
1320                 desc_count += ext4_free_inodes_count(sb, gdp);
1321                 cond_resched();
1322         }
1323         return desc_count;
1324 #endif
1325 }
1326
1327 /* Called at mount-time, super-block is locked */
1328 unsigned long ext4_count_dirs(struct super_block * sb)
1329 {
1330         unsigned long count = 0;
1331         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1332
1333         for (i = 0; i < ngroups; i++) {
1334                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1335                 if (!gdp)
1336                         continue;
1337                 count += ext4_used_dirs_count(sb, gdp);
1338         }
1339         return count;
1340 }
1341
1342 /*
1343  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1344  * inode table. Must be called without any spinlock held. The only place
1345  * where it is called from on active part of filesystem is ext4lazyinit
1346  * thread, so we do not need any special locks, however we have to prevent
1347  * inode allocation from the current group, so we take alloc_sem lock, to
1348  * block ext4_new_inode() until we are finished.
1349  */
1350 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1351                                  int barrier)
1352 {
1353         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1354         struct ext4_sb_info *sbi = EXT4_SB(sb);
1355         struct ext4_group_desc *gdp = NULL;
1356         struct buffer_head *group_desc_bh;
1357         handle_t *handle;
1358         ext4_fsblk_t blk;
1359         int num, ret = 0, used_blks = 0;
1360         unsigned long used_inos = 0;
1361
1362         /* This should not happen, but just to be sure check this */
1363         if (sb_rdonly(sb)) {
1364                 ret = 1;
1365                 goto out;
1366         }
1367
1368         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1369         if (!gdp)
1370                 goto out;
1371
1372         /*
1373          * We do not need to lock this, because we are the only one
1374          * handling this flag.
1375          */
1376         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1377                 goto out;
1378
1379         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1380         if (IS_ERR(handle)) {
1381                 ret = PTR_ERR(handle);
1382                 goto out;
1383         }
1384
1385         down_write(&grp->alloc_sem);
1386         /*
1387          * If inode bitmap was already initialized there may be some
1388          * used inodes so we need to skip blocks with used inodes in
1389          * inode table.
1390          */
1391         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1392                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1393                             ext4_itable_unused_count(sb, gdp);
1394                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1395
1396                 /* Bogus inode unused count? */
1397                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1398                         ext4_error(sb, "Something is wrong with group %u: "
1399                                    "used itable blocks: %d; "
1400                                    "itable unused count: %u",
1401                                    group, used_blks,
1402                                    ext4_itable_unused_count(sb, gdp));
1403                         ret = 1;
1404                         goto err_out;
1405                 }
1406
1407                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1408                 /*
1409                  * Are there some uninitialized inodes in the inode table
1410                  * before the first normal inode?
1411                  */
1412                 if ((used_blks != sbi->s_itb_per_group) &&
1413                      (used_inos < EXT4_FIRST_INO(sb))) {
1414                         ext4_error(sb, "Something is wrong with group %u: "
1415                                    "itable unused count: %u; "
1416                                    "itables initialized count: %ld",
1417                                    group, ext4_itable_unused_count(sb, gdp),
1418                                    used_inos);
1419                         ret = 1;
1420                         goto err_out;
1421                 }
1422         }
1423
1424         blk = ext4_inode_table(sb, gdp) + used_blks;
1425         num = sbi->s_itb_per_group - used_blks;
1426
1427         BUFFER_TRACE(group_desc_bh, "get_write_access");
1428         ret = ext4_journal_get_write_access(handle,
1429                                             group_desc_bh);
1430         if (ret)
1431                 goto err_out;
1432
1433         /*
1434          * Skip zeroout if the inode table is full. But we set the ZEROED
1435          * flag anyway, because obviously, when it is full it does not need
1436          * further zeroing.
1437          */
1438         if (unlikely(num == 0))
1439                 goto skip_zeroout;
1440
1441         ext4_debug("going to zero out inode table in group %d\n",
1442                    group);
1443         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1444         if (ret < 0)
1445                 goto err_out;
1446         if (barrier)
1447                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1448
1449 skip_zeroout:
1450         ext4_lock_group(sb, group);
1451         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1452         ext4_group_desc_csum_set(sb, group, gdp);
1453         ext4_unlock_group(sb, group);
1454
1455         BUFFER_TRACE(group_desc_bh,
1456                      "call ext4_handle_dirty_metadata");
1457         ret = ext4_handle_dirty_metadata(handle, NULL,
1458                                          group_desc_bh);
1459
1460 err_out:
1461         up_write(&grp->alloc_sem);
1462         ext4_journal_stop(handle);
1463 out:
1464         return ret;
1465 }