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 /* Initializes an uninitialized inode bitmap */
  70 static int ext4_init_inode_bitmap(struct super_block *sb,
  71                                        struct buffer_head *bh,
  72                                        ext4_group_t block_group,
  73                                        struct ext4_group_desc *gdp)
  74 {
  75         struct ext4_group_info *grp;
  76         struct ext4_sb_info *sbi = EXT4_SB(sb);
  77         J_ASSERT_BH(bh, buffer_locked(bh));
  78
  79         /* If checksum is bad mark all blocks and inodes use to prevent
  80          * allocation, essentially implementing a per-group read-only flag. */
  81         if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
  82                 grp = ext4_get_group_info(sb, block_group);
  83                 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
  84                         percpu_counter_sub(&sbi->s_freeclusters_counter,
  85                                            grp->bb_free);
  86                 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
  87                 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
  88                         int count;
  89                         count = ext4_free_inodes_count(sb, gdp);
  90                         percpu_counter_sub(&sbi->s_freeinodes_counter,
  91                                            count);
  92                 }
  93                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
  94                 return -EFSBADCRC;
  95         }
  96
  97         memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
  98         ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
  99                         bh->b_data);
 100         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
 101                                    EXT4_INODES_PER_GROUP(sb) / 8);
 102         ext4_group_desc_csum_set(sb, block_group, gdp);
 103
 104         return 0;
 105 }
 106
 107 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
 108 {
 109         if (uptodate) {
 110                 set_buffer_uptodate(bh);
 111                 set_bitmap_uptodate(bh);
 112         }
 113         unlock_buffer(bh);
 114         put_bh(bh);
 115 }
 116
 117 static int ext4_validate_inode_bitmap(struct super_block *sb,
 118                                       struct ext4_group_desc *desc,
 119                                       ext4_group_t block_group,
 120                                       struct buffer_head *bh)
 121 {
 122         ext4_fsblk_t    blk;
 123         struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
 124         struct ext4_sb_info *sbi = EXT4_SB(sb);
 125
 126         if (buffer_verified(bh))
 127                 return 0;
 128         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 129                 return -EFSCORRUPTED;
 130
 131         ext4_lock_group(sb, block_group);
 132         blk = ext4_inode_bitmap(sb, desc);
 133         if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
 134                                            EXT4_INODES_PER_GROUP(sb) / 8)) {
 135                 ext4_unlock_group(sb, block_group);
 136                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
 137                            "inode_bitmap = %llu", block_group, blk);
 138                 grp = ext4_get_group_info(sb, block_group);
 139                 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 140                         int count;
 141                         count = ext4_free_inodes_count(sb, desc);
 142                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 143                                            count);
 144                 }
 145                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
 146                 return -EFSBADCRC;
 147         }
 148         set_buffer_verified(bh);
 149         ext4_unlock_group(sb, block_group);
 150         return 0;
 151 }
 152
 153 /*
 154  * Read the inode allocation bitmap for a given block_group, reading
 155  * into the specified slot in the superblock's bitmap cache.
 156  *
 157  * Return buffer_head of bitmap on success or NULL.
 158  */
 159 static struct buffer_head *
 160 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 161 {
 162         struct ext4_group_desc *desc;
 163         struct buffer_head *bh = NULL;
 164         ext4_fsblk_t bitmap_blk;
 165         int err;
 166
 167         desc = ext4_get_group_desc(sb, block_group, NULL);
 168         if (!desc)
 169                 return ERR_PTR(-EFSCORRUPTED);
 170
 171         bitmap_blk = ext4_inode_bitmap(sb, desc);
 172         bh = sb_getblk(sb, bitmap_blk);
 173         if (unlikely(!bh)) {
 174                 ext4_error(sb, "Cannot read inode bitmap - "
 175                             "block_group = %u, inode_bitmap = %llu",
 176                             block_group, bitmap_blk);
 177                 return ERR_PTR(-EIO);
 178         }
 179         if (bitmap_uptodate(bh))
 180                 goto verify;
 181
 182         lock_buffer(bh);
 183         if (bitmap_uptodate(bh)) {
 184                 unlock_buffer(bh);
 185                 goto verify;
 186         }
 187
 188         ext4_lock_group(sb, block_group);
 189         if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
 190                 err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
 191                 set_bitmap_uptodate(bh);
 192                 set_buffer_uptodate(bh);
 193                 set_buffer_verified(bh);
 194                 ext4_unlock_group(sb, block_group);
 195                 unlock_buffer(bh);
 196                 if (err) {
 197                         ext4_error(sb, "Failed to init inode bitmap for group "
 198                                    "%u: %d", block_group, err);
 199                         goto out;
 200                 }
 201                 return bh;
 202         }
 203         ext4_unlock_group(sb, block_group);
 204
 205         if (buffer_uptodate(bh)) {
 206                 /*
 207                  * if not uninit if bh is uptodate,
 208                  * bitmap is also uptodate
 209                  */
 210                 set_bitmap_uptodate(bh);
 211                 unlock_buffer(bh);
 212                 goto verify;
 213         }
 214         /*
 215          * submit the buffer_head for reading
 216          */
 217         trace_ext4_load_inode_bitmap(sb, block_group);
 218         bh->b_end_io = ext4_end_bitmap_read;
 219         get_bh(bh);
 220         submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 221         wait_on_buffer(bh);
 222         if (!buffer_uptodate(bh)) {
 223                 put_bh(bh);
 224                 ext4_error(sb, "Cannot read inode bitmap - "
 225                            "block_group = %u, inode_bitmap = %llu",
 226                            block_group, bitmap_blk);
 227                 return ERR_PTR(-EIO);
 228         }
 229
 230 verify:
 231         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
 232         if (err)
 233                 goto out;
 234         return bh;
 235 out:
 236         put_bh(bh);
 237         return ERR_PTR(err);
 238 }
 239
 240 /*
 241  * NOTE! When we get the inode, we're the only people
 242  * that have access to it, and as such there are no
 243  * race conditions we have to worry about. The inode
 244  * is not on the hash-lists, and it cannot be reached
 245  * through the filesystem because the directory entry
 246  * has been deleted earlier.
 247  *
 248  * HOWEVER: we must make sure that we get no aliases,
 249  * which means that we have to call "clear_inode()"
 250  * _before_ we mark the inode not in use in the inode
 251  * bitmaps. Otherwise a newly created file might use
 252  * the same inode number (not actually the same pointer
 253  * though), and then we'd have two inodes sharing the
 254  * same inode number and space on the harddisk.
 255  */
 256 void ext4_free_inode(handle_t *handle, struct inode *inode)
 257 {
 258         struct super_block *sb = inode->i_sb;
 259         int is_directory;
 260         unsigned long ino;
 261         struct buffer_head *bitmap_bh = NULL;
 262         struct buffer_head *bh2;
 263         ext4_group_t block_group;
 264         unsigned long bit;
 265         struct ext4_group_desc *gdp;
 266         struct ext4_super_block *es;
 267         struct ext4_sb_info *sbi;
 268         int fatal = 0, err, count, cleared;
 269         struct ext4_group_info *grp;
 270
 271         if (!sb) {
 272                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
 273                        "nonexistent device\n", __func__, __LINE__);
 274                 return;
 275         }
 276         if (atomic_read(&inode->i_count) > 1) {
 277                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
 278                          __func__, __LINE__, inode->i_ino,
 279                          atomic_read(&inode->i_count));
 280                 return;
 281         }
 282         if (inode->i_nlink) {
 283                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
 284                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
 285                 return;
 286         }
 287         sbi = EXT4_SB(sb);
 288
 289         ino = inode->i_ino;
 290         ext4_debug("freeing inode %lu\n", ino);
 291         trace_ext4_free_inode(inode);
 292
 293         /*
 294          * Note: we must free any quota before locking the superblock,
 295          * as writing the quota to disk may need the lock as well.
 296          */
 297         dquot_initialize(inode);
 298         dquot_free_inode(inode);
 299         dquot_drop(inode);
 300
 301         is_directory = S_ISDIR(inode->i_mode);
 302
 303         /* Do this BEFORE marking the inode not in use or returning an error */
 304         ext4_clear_inode(inode);
 305
 306         es = EXT4_SB(sb)->s_es;
 307         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 308                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 309                 goto error_return;
 310         }
 311         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 312         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 313         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 314         /* Don't bother if the inode bitmap is corrupt. */
 315         grp = ext4_get_group_info(sb, block_group);
 316         if (IS_ERR(bitmap_bh)) {
 317                 fatal = PTR_ERR(bitmap_bh);
 318                 bitmap_bh = NULL;
 319                 goto error_return;
 320         }
 321         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
 322                 fatal = -EFSCORRUPTED;
 323                 goto error_return;
 324         }
 325
 326         BUFFER_TRACE(bitmap_bh, "get_write_access");
 327         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
 328         if (fatal)
 329                 goto error_return;
 330
 331         fatal = -ESRCH;
 332         gdp = ext4_get_group_desc(sb, block_group, &bh2);
 333         if (gdp) {
 334                 BUFFER_TRACE(bh2, "get_write_access");
 335                 fatal = ext4_journal_get_write_access(handle, bh2);
 336         }
 337         ext4_lock_group(sb, block_group);
 338         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
 339         if (fatal || !cleared) {
 340                 ext4_unlock_group(sb, block_group);
 341                 goto out;
 342         }
 343
 344         count = ext4_free_inodes_count(sb, gdp) + 1;
 345         ext4_free_inodes_set(sb, gdp, count);
 346         if (is_directory) {
 347                 count = ext4_used_dirs_count(sb, gdp) - 1;
 348                 ext4_used_dirs_set(sb, gdp, count);
 349                 percpu_counter_dec(&sbi->s_dirs_counter);
 350         }
 351         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
 352                                    EXT4_INODES_PER_GROUP(sb) / 8);
 353         ext4_group_desc_csum_set(sb, block_group, gdp);
 354         ext4_unlock_group(sb, block_group);
 355
 356         percpu_counter_inc(&sbi->s_freeinodes_counter);
 357         if (sbi->s_log_groups_per_flex) {
 358                 ext4_group_t f = ext4_flex_group(sbi, block_group);
 359
 360                 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
 361                 if (is_directory)
 362                         atomic_dec(&sbi->s_flex_groups[f].used_dirs);
 363         }
 364         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
 365         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
 366 out:
 367         if (cleared) {
 368                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
 369                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 370                 if (!fatal)
 371                         fatal = err;
 372         } else {
 373                 ext4_error(sb, "bit already cleared for inode %lu", ino);
 374                 if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 375                         int count;
 376                         count = ext4_free_inodes_count(sb, gdp);
 377                         percpu_counter_sub(&sbi->s_freeinodes_counter,
 378                                            count);
 379                 }
 380                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
 381         }
 382
 383 error_return:
 384         brelse(bitmap_bh);
 385         ext4_std_error(sb, fatal);
 386 }
 387
 388 struct orlov_stats {
 389         __u64 free_clusters;
 390         __u32 free_inodes;
 391         __u32 used_dirs;
 392 };
 393
 394 /*
 395  * Helper function for Orlov's allocator; returns critical information
 396  * for a particular block group or flex_bg.  If flex_size is 1, then g
 397  * is a block group number; otherwise it is flex_bg number.
 398  */
 399 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
 400                             int flex_size, struct orlov_stats *stats)
 401 {
 402         struct ext4_group_desc *desc;
 403         struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
 404
 405         if (flex_size > 1) {
 406                 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
 407                 stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
 408                 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
 409                 return;
 410         }
 411
 412         desc = ext4_get_group_desc(sb, g, NULL);
 413         if (desc) {
 414                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
 415                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
 416                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
 417         } else {
 418                 stats->free_inodes = 0;
 419                 stats->free_clusters = 0;
 420                 stats->used_dirs = 0;
 421         }
 422 }
 423
 424 /*
 425  * Orlov's allocator for directories.
 426  *
 427  * We always try to spread first-level directories.
 428  *
 429  * If there are blockgroups with both free inodes and free blocks counts
 430  * not worse than average we return one with smallest directory count.
 431  * Otherwise we simply return a random group.
 432  *
 433  * For the rest rules look so:
 434  *
 435  * It's OK to put directory into a group unless
 436  * it has too many directories already (max_dirs) or
 437  * it has too few free inodes left (min_inodes) or
 438  * it has too few free blocks left (min_blocks) or
 439  * Parent's group is preferred, if it doesn't satisfy these
 440  * conditions we search cyclically through the rest. If none
 441  * of the groups look good we just look for a group with more
 442  * free inodes than average (starting at parent's group).
 443  */
 444
 445 static int find_group_orlov(struct super_block *sb, struct inode *parent,
 446                             ext4_group_t *group, umode_t mode,
 447                             const struct qstr *qstr)
 448 {
 449         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 450         struct ext4_sb_info *sbi = EXT4_SB(sb);
 451         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
 452         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
 453         unsigned int freei, avefreei, grp_free;
 454         ext4_fsblk_t freeb, avefreec;
 455         unsigned int ndirs;
 456         int max_dirs, min_inodes;
 457         ext4_grpblk_t min_clusters;
 458         ext4_group_t i, grp, g, ngroups;
 459         struct ext4_group_desc *desc;
 460         struct orlov_stats stats;
 461         int flex_size = ext4_flex_bg_size(sbi);
 462         struct dx_hash_info hinfo;
 463
 464         ngroups = real_ngroups;
 465         if (flex_size > 1) {
 466                 ngroups = (real_ngroups + flex_size - 1) >>
 467                         sbi->s_log_groups_per_flex;
 468                 parent_group >>= sbi->s_log_groups_per_flex;
 469         }
 470
 471         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
 472         avefreei = freei / ngroups;
 473         freeb = EXT4_C2B(sbi,
 474                 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
 475         avefreec = freeb;
 476         do_div(avefreec, ngroups);
 477         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
 478
 479         if (S_ISDIR(mode) &&
 480             ((parent == d_inode(sb->s_root)) ||
 481              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
 482                 int best_ndir = inodes_per_group;
 483                 int ret = -1;
 484
 485                 if (qstr) {
 486                         hinfo.hash_version = DX_HASH_HALF_MD4;
 487                         hinfo.seed = sbi->s_hash_seed;
 488                         ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
 489                         grp = hinfo.hash;
 490                 } else
 491                         grp = prandom_u32();
 492                 parent_group = (unsigned)grp % ngroups;
 493                 for (i = 0; i < ngroups; i++) {
 494                         g = (parent_group + i) % ngroups;
 495                         get_orlov_stats(sb, g, flex_size, &stats);
 496                         if (!stats.free_inodes)
 497                                 continue;
 498                         if (stats.used_dirs >= best_ndir)
 499                                 continue;
 500                         if (stats.free_inodes < avefreei)
 501                                 continue;
 502                         if (stats.free_clusters < avefreec)
 503                                 continue;
 504                         grp = g;
 505                         ret = 0;
 506                         best_ndir = stats.used_dirs;
 507                 }
 508                 if (ret)
 509                         goto fallback;
 510         found_flex_bg:
 511                 if (flex_size == 1) {
 512                         *group = grp;
 513                         return 0;
 514                 }
 515
 516                 /*
 517                  * We pack inodes at the beginning of the flexgroup's
 518                  * inode tables.  Block allocation decisions will do
 519                  * something similar, although regular files will
 520                  * start at 2nd block group of the flexgroup.  See
 521                  * ext4_ext_find_goal() and ext4_find_near().
 522                  */
 523                 grp *= flex_size;
 524                 for (i = 0; i < flex_size; i++) {
 525                         if (grp+i >= real_ngroups)
 526                                 break;
 527                         desc = ext4_get_group_desc(sb, grp+i, NULL);
 528                         if (desc && ext4_free_inodes_count(sb, desc)) {
 529                                 *group = grp+i;
 530                                 return 0;
 531                         }
 532                 }
 533                 goto fallback;
 534         }
 535
 536         max_dirs = ndirs / ngroups + inodes_per_group / 16;
 537         min_inodes = avefreei - inodes_per_group*flex_size / 4;
 538         if (min_inodes < 1)
 539                 min_inodes = 1;
 540         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
 541
 542         /*
 543          * Start looking in the flex group where we last allocated an
 544          * inode for this parent directory
 545          */
 546         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
 547                 parent_group = EXT4_I(parent)->i_last_alloc_group;
 548                 if (flex_size > 1)
 549                         parent_group >>= sbi->s_log_groups_per_flex;
 550         }
 551
 552         for (i = 0; i < ngroups; i++) {
 553                 grp = (parent_group + i) % ngroups;
 554                 get_orlov_stats(sb, grp, flex_size, &stats);
 555                 if (stats.used_dirs >= max_dirs)
 556                         continue;
 557                 if (stats.free_inodes < min_inodes)
 558                         continue;
 559                 if (stats.free_clusters < min_clusters)
 560                         continue;
 561                 goto found_flex_bg;
 562         }
 563
 564 fallback:
 565         ngroups = real_ngroups;
 566         avefreei = freei / ngroups;
 567 fallback_retry:
 568         parent_group = EXT4_I(parent)->i_block_group;
 569         for (i = 0; i < ngroups; i++) {
 570                 grp = (parent_group + i) % ngroups;
 571                 desc = ext4_get_group_desc(sb, grp, NULL);
 572                 if (desc) {
 573                         grp_free = ext4_free_inodes_count(sb, desc);
 574                         if (grp_free && grp_free >= avefreei) {
 575                                 *group = grp;
 576                                 return 0;
 577                         }
 578                 }
 579         }
 580
 581         if (avefreei) {
 582                 /*
 583                  * The free-inodes counter is approximate, and for really small
 584                  * filesystems the above test can fail to find any blockgroups
 585                  */
 586                 avefreei = 0;
 587                 goto fallback_retry;
 588         }
 589
 590         return -1;
 591 }
 592
 593 static int find_group_other(struct super_block *sb, struct inode *parent,
 594                             ext4_group_t *group, umode_t mode)
 595 {
 596         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 597         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
 598         struct ext4_group_desc *desc;
 599         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
 600
 601         /*
 602          * Try to place the inode is the same flex group as its
 603          * parent.  If we can't find space, use the Orlov algorithm to
 604          * find another flex group, and store that information in the
 605          * parent directory's inode information so that use that flex
 606          * group for future allocations.
 607          */
 608         if (flex_size > 1) {
 609                 int retry = 0;
 610
 611         try_again:
 612                 parent_group &= ~(flex_size-1);
 613                 last = parent_group + flex_size;
 614                 if (last > ngroups)
 615                         last = ngroups;
 616                 for  (i = parent_group; i < last; i++) {
 617                         desc = ext4_get_group_desc(sb, i, NULL);
 618                         if (desc && ext4_free_inodes_count(sb, desc)) {
 619                                 *group = i;
 620                                 return 0;
 621                         }
 622                 }
 623                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
 624                         retry = 1;
 625                         parent_group = EXT4_I(parent)->i_last_alloc_group;
 626                         goto try_again;
 627                 }
 628                 /*
 629                  * If this didn't work, use the Orlov search algorithm
 630                  * to find a new flex group; we pass in the mode to
 631                  * avoid the topdir algorithms.
 632                  */
 633                 *group = parent_group + flex_size;
 634                 if (*group > ngroups)
 635                         *group = 0;
 636                 return find_group_orlov(sb, parent, group, mode, NULL);
 637         }
 638
 639         /*
 640          * Try to place the inode in its parent directory
 641          */
 642         *group = parent_group;
 643         desc = ext4_get_group_desc(sb, *group, NULL);
 644         if (desc && ext4_free_inodes_count(sb, desc) &&
 645             ext4_free_group_clusters(sb, desc))
 646                 return 0;
 647
 648         /*
 649          * We're going to place this inode in a different blockgroup from its
 650          * parent.  We want to cause files in a common directory to all land in
 651          * the same blockgroup.  But we want files which are in a different
 652          * directory which shares a blockgroup with our parent to land in a
 653          * different blockgroup.
 654          *
 655          * So add our directory's i_ino into the starting point for the hash.
 656          */
 657         *group = (*group + parent->i_ino) % ngroups;
 658
 659         /*
 660          * Use a quadratic hash to find a group with a free inode and some free
 661          * blocks.
 662          */
 663         for (i = 1; i < ngroups; i <<= 1) {
 664                 *group += i;
 665                 if (*group >= ngroups)
 666                         *group -= ngroups;
 667                 desc = ext4_get_group_desc(sb, *group, NULL);
 668                 if (desc && ext4_free_inodes_count(sb, desc) &&
 669                     ext4_free_group_clusters(sb, desc))
 670                         return 0;
 671         }
 672
 673         /*
 674          * That failed: try linear search for a free inode, even if that group
 675          * has no free blocks.
 676          */
 677         *group = parent_group;
 678         for (i = 0; i < ngroups; i++) {
 679                 if (++*group >= ngroups)
 680                         *group = 0;
 681                 desc = ext4_get_group_desc(sb, *group, NULL);
 682                 if (desc && ext4_free_inodes_count(sb, desc))
 683                         return 0;
 684         }
 685
 686         return -1;
 687 }
 688
 689 /*
 690  * In no journal mode, if an inode has recently been deleted, we want
 691  * to avoid reusing it until we're reasonably sure the inode table
 692  * block has been written back to disk.  (Yes, these values are
 693  * somewhat arbitrary...)
 694  */
 695 #define RECENTCY_MIN    5
 696 #define RECENTCY_DIRTY  300
 697
 698 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 699 {
 700         struct ext4_group_desc  *gdp;
 701         struct ext4_inode       *raw_inode;
 702         struct buffer_head      *bh;
 703         int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 704         int offset, ret = 0;
 705         int recentcy = RECENTCY_MIN;
 706         u32 dtime, now;
 707
 708         gdp = ext4_get_group_desc(sb, group, NULL);
 709         if (unlikely(!gdp))
 710                 return 0;
 711
 712         bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 713                        (ino / inodes_per_block));
 714         if (!bh || !buffer_uptodate(bh))
 715                 /*
 716                  * If the block is not in the buffer cache, then it
 717                  * must have been written out.
 718                  */
 719                 goto out;
 720
 721         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 722         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
 723
 724         /* i_dtime is only 32 bits on disk, but we only care about relative
 725          * times in the range of a few minutes (i.e. long enough to sync a
 726          * recently-deleted inode to disk), so using the low 32 bits of the
 727          * clock (a 68 year range) is enough, see time_before32() */
 728         dtime = le32_to_cpu(raw_inode->i_dtime);
 729         now = ktime_get_real_seconds();
 730         if (buffer_dirty(bh))
 731                 recentcy += RECENTCY_DIRTY;
 732
 733         if (dtime && time_before32(dtime, now) &&
 734             time_before32(now, dtime + recentcy))
 735                 ret = 1;
 736 out:
 737         brelse(bh);
 738         return ret;
 739 }
 740
 741 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
 742                           struct buffer_head *bitmap, unsigned long *ino)
 743 {
 744 next:
 745         *ino = ext4_find_next_zero_bit((unsigned long *)
 746                                        bitmap->b_data,
 747                                        EXT4_INODES_PER_GROUP(sb), *ino);
 748         if (*ino >= EXT4_INODES_PER_GROUP(sb))
 749                 return 0;
 750
 751         if ((EXT4_SB(sb)->s_journal == NULL) &&
 752             recently_deleted(sb, group, *ino)) {
 753                 *ino = *ino + 1;
 754                 if (*ino < EXT4_INODES_PER_GROUP(sb))
 755                         goto next;
 756                 return 0;
 757         }
 758
 759         return 1;
 760 }
 761
 762 /*
 763  * There are two policies for allocating an inode.  If the new inode is
 764  * a directory, then a forward search is made for a block group with both
 765  * free space and a low directory-to-inode ratio; if that fails, then of
 766  * the groups with above-average free space, that group with the fewest
 767  * directories already is chosen.
 768  *
 769  * For other inodes, search forward from the parent directory's block
 770  * group to find a free inode.
 771  */
 772 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 773                                umode_t mode, const struct qstr *qstr,
 774                                __u32 goal, uid_t *owner, __u32 i_flags,
 775                                int handle_type, unsigned int line_no,
 776                                int nblocks)
 777 {
 778         struct super_block *sb;
 779         struct buffer_head *inode_bitmap_bh = NULL;
 780         struct buffer_head *group_desc_bh;
 781         ext4_group_t ngroups, group = 0;
 782         unsigned long ino = 0;
 783         struct inode *inode;
 784         struct ext4_group_desc *gdp = NULL;
 785         struct ext4_inode_info *ei;
 786         struct ext4_sb_info *sbi;
 787         int ret2, err;
 788         struct inode *ret;
 789         ext4_group_t i;
 790         ext4_group_t flex_group;
 791         struct ext4_group_info *grp;
 792         int encrypt = 0;
 793
 794         /* Cannot create files in a deleted directory */
 795         if (!dir || !dir->i_nlink)
 796                 return ERR_PTR(-EPERM);
 797
 798         sb = dir->i_sb;
 799         sbi = EXT4_SB(sb);
 800
 801         if (unlikely(ext4_forced_shutdown(sbi)))
 802                 return ERR_PTR(-EIO);
 803
 804         if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
 805             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
 806             !(i_flags & EXT4_EA_INODE_FL)) {
 807                 err = fscrypt_get_encryption_info(dir);
 808                 if (err)
 809                         return ERR_PTR(err);
 810                 if (!fscrypt_has_encryption_key(dir))
 811                         return ERR_PTR(-ENOKEY);
 812                 encrypt = 1;
 813         }
 814
 815         if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
 816 #ifdef CONFIG_EXT4_FS_POSIX_ACL
 817                 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
 818
 819                 if (IS_ERR(p))
 820                         return ERR_CAST(p);
 821                 if (p) {
 822                         int acl_size = p->a_count * sizeof(ext4_acl_entry);
 823
 824                         nblocks += (S_ISDIR(mode) ? 2 : 1) *
 825                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 826                                         NULL /* block_bh */, acl_size,
 827                                         true /* is_create */);
 828                         posix_acl_release(p);
 829                 }
 830 #endif
 831
 832 #ifdef CONFIG_SECURITY
 833                 {
 834                         int num_security_xattrs = 1;
 835
 836 #ifdef CONFIG_INTEGRITY
 837                         num_security_xattrs++;
 838 #endif
 839                         /*
 840                          * We assume that security xattrs are never
 841                          * more than 1k.  In practice they are under
 842                          * 128 bytes.
 843                          */
 844                         nblocks += num_security_xattrs *
 845                                 __ext4_xattr_set_credits(sb, NULL /* inode */,
 846                                         NULL /* block_bh */, 1024,
 847                                         true /* is_create */);
 848                 }
 849 #endif
 850                 if (encrypt)
 851                         nblocks += __ext4_xattr_set_credits(sb,
 852                                         NULL /* inode */, NULL /* block_bh */,
 853                                         FSCRYPT_SET_CONTEXT_MAX_SIZE,
 854                                         true /* is_create */);
 855         }
 856
 857         ngroups = ext4_get_groups_count(sb);
 858         trace_ext4_request_inode(dir, mode);
 859         inode = new_inode(sb);
 860         if (!inode)
 861                 return ERR_PTR(-ENOMEM);
 862         ei = EXT4_I(inode);
 863
 864         /*
 865          * Initialize owners and quota early so that we don't have to account
 866          * for quota initialization worst case in standard inode creating
 867          * transaction
 868          */
 869         if (owner) {
 870                 inode->i_mode = mode;
 871                 i_uid_write(inode, owner[0]);
 872                 i_gid_write(inode, owner[1]);
 873         } else if (test_opt(sb, GRPID)) {
 874                 inode->i_mode = mode;
 875                 inode->i_uid = current_fsuid();
 876                 inode->i_gid = dir->i_gid;
 877         } else
 878                 inode_init_owner(inode, dir, mode);
 879
 880         if (ext4_has_feature_project(sb) &&
 881             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
 882                 ei->i_projid = EXT4_I(dir)->i_projid;
 883         else
 884                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
 885
 886         err = dquot_initialize(inode);
 887         if (err)
 888                 goto out;
 889
 890         if (!goal)
 891                 goal = sbi->s_inode_goal;
 892
 893         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
 894                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
 895                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
 896                 ret2 = 0;
 897                 goto got_group;
 898         }
 899
 900         if (S_ISDIR(mode))
 901                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
 902         else
 903                 ret2 = find_group_other(sb, dir, &group, mode);
 904
 905 got_group:
 906         EXT4_I(dir)->i_last_alloc_group = group;
 907         err = -ENOSPC;
 908         if (ret2 == -1)
 909                 goto out;
 910
 911         /*
 912          * Normally we will only go through one pass of this loop,
 913          * unless we get unlucky and it turns out the group we selected
 914          * had its last inode grabbed by someone else.
 915          */
 916         for (i = 0; i < ngroups; i++, ino = 0) {
 917                 err = -EIO;
 918
 919                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
 920                 if (!gdp)
 921                         goto out;
 922
 923                 /*
 924                  * Check free inodes count before loading bitmap.
 925                  */
 926                 if (ext4_free_inodes_count(sb, gdp) == 0)
 927                         goto next_group;
 928
 929                 grp = ext4_get_group_info(sb, group);
 930                 /* Skip groups with already-known suspicious inode tables */
 931                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
 932                         goto next_group;
 933
 934                 brelse(inode_bitmap_bh);
 935                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
 936                 /* Skip groups with suspicious inode tables */
 937                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 938                     IS_ERR(inode_bitmap_bh)) {
 939                         inode_bitmap_bh = NULL;
 940                         goto next_group;
 941                 }
 942
 943 repeat_in_this_group:
 944                 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 945                 if (!ret2)
 946                         goto next_group;
 947
 948                 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 949                         ext4_error(sb, "reserved inode found cleared - "
 950                                    "inode=%lu", ino + 1);
 951                         goto next_group;
 952                 }
 953
 954                 if (!handle) {
 955                         BUG_ON(nblocks <= 0);
 956                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
 957                                                          handle_type, nblocks,
 958                                                          0);
 959                         if (IS_ERR(handle)) {
 960                                 err = PTR_ERR(handle);
 961                                 ext4_std_error(sb, err);
 962                                 goto out;
 963                         }
 964                 }
 965                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
 966                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
 967                 if (err) {
 968                         ext4_std_error(sb, err);
 969                         goto out;
 970                 }
 971                 ext4_lock_group(sb, group);
 972                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
 973                 if (ret2) {
 974                         /* Someone already took the bit. Repeat the search
 975                          * with lock held.
 976                          */
 977                         ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
 978                         if (ret2) {
 979                                 ext4_set_bit(ino, inode_bitmap_bh->b_data);
 980                                 ret2 = 0;
 981                         } else {
 982                                 ret2 = 1; /* we didn't grab the inode */
 983                         }
 984                 }
 985                 ext4_unlock_group(sb, group);
 986                 ino++;          /* the inode bitmap is zero-based */
 987                 if (!ret2)
 988                         goto got; /* we grabbed the inode! */
 989
 990                 if (ino < EXT4_INODES_PER_GROUP(sb))
 991                         goto repeat_in_this_group;
 992 next_group:
 993                 if (++group == ngroups)
 994                         group = 0;
 995         }
 996         err = -ENOSPC;
 997         goto out;
 998
 999 got:
1000         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1001         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1002         if (err) {
1003                 ext4_std_error(sb, err);
1004                 goto out;
1005         }
1006
1007         BUFFER_TRACE(group_desc_bh, "get_write_access");
1008         err = ext4_journal_get_write_access(handle, group_desc_bh);
1009         if (err) {
1010                 ext4_std_error(sb, err);
1011                 goto out;
1012         }
1013
1014         /* We may have to initialize the block bitmap if it isn't already */
1015         if (ext4_has_group_desc_csum(sb) &&
1016             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1017                 struct buffer_head *block_bitmap_bh;
1018
1019                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1020                 if (IS_ERR(block_bitmap_bh)) {
1021                         err = PTR_ERR(block_bitmap_bh);
1022                         goto out;
1023                 }
1024                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1025                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1026                 if (err) {
1027                         brelse(block_bitmap_bh);
1028                         ext4_std_error(sb, err);
1029                         goto out;
1030                 }
1031
1032                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1033                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1034
1035                 /* recheck and clear flag under lock if we still need to */
1036                 ext4_lock_group(sb, group);
1037                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1038                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1039                         ext4_free_group_clusters_set(sb, gdp,
1040                                 ext4_free_clusters_after_init(sb, group, gdp));
1041                         ext4_block_bitmap_csum_set(sb, group, gdp,
1042                                                    block_bitmap_bh);
1043                         ext4_group_desc_csum_set(sb, group, gdp);
1044                 }
1045                 ext4_unlock_group(sb, group);
1046                 brelse(block_bitmap_bh);
1047
1048                 if (err) {
1049                         ext4_std_error(sb, err);
1050                         goto out;
1051                 }
1052         }
1053
1054         /* Update the relevant bg descriptor fields */
1055         if (ext4_has_group_desc_csum(sb)) {
1056                 int free;
1057                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1058
1059                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1060                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1061                 free = EXT4_INODES_PER_GROUP(sb) -
1062                         ext4_itable_unused_count(sb, gdp);
1063                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1064                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1065                         free = 0;
1066                 }
1067                 /*
1068                  * Check the relative inode number against the last used
1069                  * relative inode number in this group. if it is greater
1070                  * we need to update the bg_itable_unused count
1071                  */
1072                 if (ino > free)
1073                         ext4_itable_unused_set(sb, gdp,
1074                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1075                 up_read(&grp->alloc_sem);
1076         } else {
1077                 ext4_lock_group(sb, group);
1078         }
1079
1080         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1081         if (S_ISDIR(mode)) {
1082                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1083                 if (sbi->s_log_groups_per_flex) {
1084                         ext4_group_t f = ext4_flex_group(sbi, group);
1085
1086                         atomic_inc(&sbi->s_flex_groups[f].used_dirs);
1087                 }
1088         }
1089         if (ext4_has_group_desc_csum(sb)) {
1090                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1091                                            EXT4_INODES_PER_GROUP(sb) / 8);
1092                 ext4_group_desc_csum_set(sb, group, gdp);
1093         }
1094         ext4_unlock_group(sb, group);
1095
1096         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1097         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1098         if (err) {
1099                 ext4_std_error(sb, err);
1100                 goto out;
1101         }
1102
1103         percpu_counter_dec(&sbi->s_freeinodes_counter);
1104         if (S_ISDIR(mode))
1105                 percpu_counter_inc(&sbi->s_dirs_counter);
1106
1107         if (sbi->s_log_groups_per_flex) {
1108                 flex_group = ext4_flex_group(sbi, group);
1109                 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
1110         }
1111
1112         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1113         /* This is the optimal IO size (for stat), not the fs block size */
1114         inode->i_blocks = 0;
1115         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
1116                                                        current_time(inode);
1117
1118         memset(ei->i_data, 0, sizeof(ei->i_data));
1119         ei->i_dir_start_lookup = 0;
1120         ei->i_disksize = 0;
1121
1122         /* Don't inherit extent flag from directory, amongst others. */
1123         ei->i_flags =
1124                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1125         ei->i_flags |= i_flags;
1126         ei->i_file_acl = 0;
1127         ei->i_dtime = 0;
1128         ei->i_block_group = group;
1129         ei->i_last_alloc_group = ~0;
1130
1131         ext4_set_inode_flags(inode);
1132         if (IS_DIRSYNC(inode))
1133                 ext4_handle_sync(handle);
1134         if (insert_inode_locked(inode) < 0) {
1135                 /*
1136                  * Likely a bitmap corruption causing inode to be allocated
1137                  * twice.
1138                  */
1139                 err = -EIO;
1140                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1141                            inode->i_ino);
1142                 goto out;
1143         }
1144         inode->i_generation = prandom_u32();
1145
1146         /* Precompute checksum seed for inode metadata */
1147         if (ext4_has_metadata_csum(sb)) {
1148                 __u32 csum;
1149                 __le32 inum = cpu_to_le32(inode->i_ino);
1150                 __le32 gen = cpu_to_le32(inode->i_generation);
1151                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1152                                    sizeof(inum));
1153                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1154                                               sizeof(gen));
1155         }
1156
1157         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1158         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1159
1160         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
1161         ei->i_inline_off = 0;
1162         if (ext4_has_feature_inline_data(sb))
1163                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1164         ret = inode;
1165         err = dquot_alloc_inode(inode);
1166         if (err)
1167                 goto fail_drop;
1168
1169         /*
1170          * Since the encryption xattr will always be unique, create it first so
1171          * that it's less likely to end up in an external xattr block and
1172          * prevent its deduplication.
1173          */
1174         if (encrypt) {
1175                 err = fscrypt_inherit_context(dir, inode, handle, true);
1176                 if (err)
1177                         goto fail_free_drop;
1178         }
1179
1180         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1181                 err = ext4_init_acl(handle, inode, dir);
1182                 if (err)
1183                         goto fail_free_drop;
1184
1185                 err = ext4_init_security(handle, inode, dir, qstr);
1186                 if (err)
1187                         goto fail_free_drop;
1188         }
1189
1190         if (ext4_has_feature_extents(sb)) {
1191                 /* set extent flag only for directory, file and normal symlink*/
1192                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1193                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1194                         ext4_ext_tree_init(handle, inode);
1195                 }
1196         }
1197
1198         if (ext4_handle_valid(handle)) {
1199                 ei->i_sync_tid = handle->h_transaction->t_tid;
1200                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1201         }
1202
1203         err = ext4_mark_inode_dirty(handle, inode);
1204         if (err) {
1205                 ext4_std_error(sb, err);
1206                 goto fail_free_drop;
1207         }
1208
1209         ext4_debug("allocating inode %lu\n", inode->i_ino);
1210         trace_ext4_allocate_inode(inode, dir, mode);
1211         brelse(inode_bitmap_bh);
1212         return ret;
1213
1214 fail_free_drop:
1215         dquot_free_inode(inode);
1216 fail_drop:
1217         clear_nlink(inode);
1218         unlock_new_inode(inode);
1219 out:
1220         dquot_drop(inode);
1221         inode->i_flags |= S_NOQUOTA;
1222         iput(inode);
1223         brelse(inode_bitmap_bh);
1224         return ERR_PTR(err);
1225 }
1226
1227 /* Verify that we are loading a valid orphan from disk */
1228 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1229 {
1230         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1231         ext4_group_t block_group;
1232         int bit;
1233         struct buffer_head *bitmap_bh = NULL;
1234         struct inode *inode = NULL;
1235         int err = -EFSCORRUPTED;
1236
1237         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1238                 goto bad_orphan;
1239
1240         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1241         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1242         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1243         if (IS_ERR(bitmap_bh)) {
1244                 ext4_error(sb, "inode bitmap error %ld for orphan %lu",
1245                            ino, PTR_ERR(bitmap_bh));
1246                 return (struct inode *) bitmap_bh;
1247         }
1248
1249         /* Having the inode bit set should be a 100% indicator that this
1250          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1251          * inodes that were being truncated, so we can't check i_nlink==0.
1252          */
1253         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1254                 goto bad_orphan;
1255
1256         inode = ext4_iget(sb, ino);
1257         if (IS_ERR(inode)) {
1258                 err = PTR_ERR(inode);
1259                 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1260                            ino, err);
1261                 return inode;
1262         }
1263
1264         /*
1265          * If the orphans has i_nlinks > 0 then it should be able to
1266          * be truncated, otherwise it won't be removed from the orphan
1267          * list during processing and an infinite loop will result.
1268          * Similarly, it must not be a bad inode.
1269          */
1270         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1271             is_bad_inode(inode))
1272                 goto bad_orphan;
1273
1274         if (NEXT_ORPHAN(inode) > max_ino)
1275                 goto bad_orphan;
1276         brelse(bitmap_bh);
1277         return inode;
1278
1279 bad_orphan:
1280         ext4_error(sb, "bad orphan inode %lu", ino);
1281         if (bitmap_bh)
1282                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1283                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1284                        ext4_test_bit(bit, bitmap_bh->b_data));
1285         if (inode) {
1286                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1287                        is_bad_inode(inode));
1288                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1289                        NEXT_ORPHAN(inode));
1290                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1291                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1292                 /* Avoid freeing blocks if we got a bad deleted inode */
1293                 if (inode->i_nlink == 0)
1294                         inode->i_blocks = 0;
1295                 iput(inode);
1296         }
1297         brelse(bitmap_bh);
1298         return ERR_PTR(err);
1299 }
1300
1301 unsigned long ext4_count_free_inodes(struct super_block *sb)
1302 {
1303         unsigned long desc_count;
1304         struct ext4_group_desc *gdp;
1305         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1306 #ifdef EXT4FS_DEBUG
1307         struct ext4_super_block *es;
1308         unsigned long bitmap_count, x;
1309         struct buffer_head *bitmap_bh = NULL;
1310
1311         es = EXT4_SB(sb)->s_es;
1312         desc_count = 0;
1313         bitmap_count = 0;
1314         gdp = NULL;
1315         for (i = 0; i < ngroups; i++) {
1316                 gdp = ext4_get_group_desc(sb, i, NULL);
1317                 if (!gdp)
1318                         continue;
1319                 desc_count += ext4_free_inodes_count(sb, gdp);
1320                 brelse(bitmap_bh);
1321                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1322                 if (IS_ERR(bitmap_bh)) {
1323                         bitmap_bh = NULL;
1324                         continue;
1325                 }
1326
1327                 x = ext4_count_free(bitmap_bh->b_data,
1328                                     EXT4_INODES_PER_GROUP(sb) / 8);
1329                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1330                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1331                 bitmap_count += x;
1332         }
1333         brelse(bitmap_bh);
1334         printk(KERN_DEBUG "ext4_count_free_inodes: "
1335                "stored = %u, computed = %lu, %lu\n",
1336                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1337         return desc_count;
1338 #else
1339         desc_count = 0;
1340         for (i = 0; i < ngroups; i++) {
1341                 gdp = ext4_get_group_desc(sb, i, NULL);
1342                 if (!gdp)
1343                         continue;
1344                 desc_count += ext4_free_inodes_count(sb, gdp);
1345                 cond_resched();
1346         }
1347         return desc_count;
1348 #endif
1349 }
1350
1351 /* Called at mount-time, super-block is locked */
1352 unsigned long ext4_count_dirs(struct super_block * sb)
1353 {
1354         unsigned long count = 0;
1355         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1356
1357         for (i = 0; i < ngroups; i++) {
1358                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1359                 if (!gdp)
1360                         continue;
1361                 count += ext4_used_dirs_count(sb, gdp);
1362         }
1363         return count;
1364 }
1365
1366 /*
1367  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1368  * inode table. Must be called without any spinlock held. The only place
1369  * where it is called from on active part of filesystem is ext4lazyinit
1370  * thread, so we do not need any special locks, however we have to prevent
1371  * inode allocation from the current group, so we take alloc_sem lock, to
1372  * block ext4_new_inode() until we are finished.
1373  */
1374 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1375                                  int barrier)
1376 {
1377         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1378         struct ext4_sb_info *sbi = EXT4_SB(sb);
1379         struct ext4_group_desc *gdp = NULL;
1380         struct buffer_head *group_desc_bh;
1381         handle_t *handle;
1382         ext4_fsblk_t blk;
1383         int num, ret = 0, used_blks = 0;
1384
1385         /* This should not happen, but just to be sure check this */
1386         if (sb_rdonly(sb)) {
1387                 ret = 1;
1388                 goto out;
1389         }
1390
1391         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1392         if (!gdp)
1393                 goto out;
1394
1395         /*
1396          * We do not need to lock this, because we are the only one
1397          * handling this flag.
1398          */
1399         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1400                 goto out;
1401
1402         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1403         if (IS_ERR(handle)) {
1404                 ret = PTR_ERR(handle);
1405                 goto out;
1406         }
1407
1408         down_write(&grp->alloc_sem);
1409         /*
1410          * If inode bitmap was already initialized there may be some
1411          * used inodes so we need to skip blocks with used inodes in
1412          * inode table.
1413          */
1414         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1415                 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1416                             ext4_itable_unused_count(sb, gdp)),
1417                             sbi->s_inodes_per_block);
1418
1419         if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1420                 ext4_error(sb, "Something is wrong with group %u: "
1421                            "used itable blocks: %d; "
1422                            "itable unused count: %u",
1423                            group, used_blks,
1424                            ext4_itable_unused_count(sb, gdp));
1425                 ret = 1;
1426                 goto err_out;
1427         }
1428
1429         blk = ext4_inode_table(sb, gdp) + used_blks;
1430         num = sbi->s_itb_per_group - used_blks;
1431
1432         BUFFER_TRACE(group_desc_bh, "get_write_access");
1433         ret = ext4_journal_get_write_access(handle,
1434                                             group_desc_bh);
1435         if (ret)
1436                 goto err_out;
1437
1438         /*
1439          * Skip zeroout if the inode table is full. But we set the ZEROED
1440          * flag anyway, because obviously, when it is full it does not need
1441          * further zeroing.
1442          */
1443         if (unlikely(num == 0))
1444                 goto skip_zeroout;
1445
1446         ext4_debug("going to zero out inode table in group %d\n",
1447                    group);
1448         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1449         if (ret < 0)
1450                 goto err_out;
1451         if (barrier)
1452                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1453
1454 skip_zeroout:
1455         ext4_lock_group(sb, group);
1456         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1457         ext4_group_desc_csum_set(sb, group, gdp);
1458         ext4_unlock_group(sb, group);
1459
1460         BUFFER_TRACE(group_desc_bh,
1461                      "call ext4_handle_dirty_metadata");
1462         ret = ext4_handle_dirty_metadata(handle, NULL,
1463                                          group_desc_bh);
1464
1465 err_out:
1466         up_write(&grp->alloc_sem);
1467         ext4_journal_stop(handle);
1468 out:
1469         return ret;
1470 }