fs/f2fs/super.c

   1 /*
   2  * fs/f2fs/super.c
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *             http://www.samsung.com/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/fs.h>
  14 #include <linux/statfs.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/kthread.h>
  19 #include <linux/parser.h>
  20 #include <linux/mount.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/random.h>
  23 #include <linux/exportfs.h>
  24 #include <linux/f2fs_fs.h>
  25
  26 #include "f2fs.h"
  27 #include "node.h"
  28 #include "xattr.h"
  29
  30 static struct kmem_cache *f2fs_inode_cachep;
  31
  32 enum {
  33         Opt_gc_background_off,
  34         Opt_disable_roll_forward,
  35         Opt_discard,
  36         Opt_noheap,
  37         Opt_nouser_xattr,
  38         Opt_noacl,
  39         Opt_active_logs,
  40         Opt_disable_ext_identify,
  41         Opt_err,
  42 };
  43
  44 static match_table_t f2fs_tokens = {
  45         {Opt_gc_background_off, "background_gc_off"},
  46         {Opt_disable_roll_forward, "disable_roll_forward"},
  47         {Opt_discard, "discard"},
  48         {Opt_noheap, "no_heap"},
  49         {Opt_nouser_xattr, "nouser_xattr"},
  50         {Opt_noacl, "noacl"},
  51         {Opt_active_logs, "active_logs=%u"},
  52         {Opt_disable_ext_identify, "disable_ext_identify"},
  53         {Opt_err, NULL},
  54 };
  55
  56 static void init_once(void *foo)
  57 {
  58         struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
  59
  60         inode_init_once(&fi->vfs_inode);
  61 }
  62
  63 static struct inode *f2fs_alloc_inode(struct super_block *sb)
  64 {
  65         struct f2fs_inode_info *fi;
  66
  67         fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_NOFS | __GFP_ZERO);
  68         if (!fi)
  69                 return NULL;
  70
  71         init_once((void *) fi);
  72
  73         /* Initilize f2fs-specific inode info */
  74         fi->vfs_inode.i_version = 1;
  75         atomic_set(&fi->dirty_dents, 0);
  76         fi->i_current_depth = 1;
  77         fi->i_advise = 0;
  78         rwlock_init(&fi->ext.ext_lock);
  79
  80         set_inode_flag(fi, FI_NEW_INODE);
  81
  82         return &fi->vfs_inode;
  83 }
  84
  85 static void f2fs_i_callback(struct rcu_head *head)
  86 {
  87         struct inode *inode = container_of(head, struct inode, i_rcu);
  88         kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
  89 }
  90
  91 static void f2fs_destroy_inode(struct inode *inode)
  92 {
  93         call_rcu(&inode->i_rcu, f2fs_i_callback);
  94 }
  95
  96 static void f2fs_put_super(struct super_block *sb)
  97 {
  98         struct f2fs_sb_info *sbi = F2FS_SB(sb);
  99
 100         f2fs_destroy_stats(sbi);
 101         stop_gc_thread(sbi);
 102
 103         write_checkpoint(sbi, false, true);
 104
 105         iput(sbi->node_inode);
 106         iput(sbi->meta_inode);
 107
 108         /* destroy f2fs internal modules */
 109         destroy_node_manager(sbi);
 110         destroy_segment_manager(sbi);
 111
 112         kfree(sbi->ckpt);
 113
 114         sb->s_fs_info = NULL;
 115         brelse(sbi->raw_super_buf);
 116         kfree(sbi);
 117 }
 118
 119 int f2fs_sync_fs(struct super_block *sb, int sync)
 120 {
 121         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 122
 123         if (!sbi->s_dirty && !get_pages(sbi, F2FS_DIRTY_NODES))
 124                 return 0;
 125
 126         if (sync)
 127                 write_checkpoint(sbi, false, false);
 128
 129         return 0;
 130 }
 131
 132 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 133 {
 134         struct super_block *sb = dentry->d_sb;
 135         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 136         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 137         block_t total_count, user_block_count, start_count, ovp_count;
 138
 139         total_count = le64_to_cpu(sbi->raw_super->block_count);
 140         user_block_count = sbi->user_block_count;
 141         start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
 142         ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
 143         buf->f_type = F2FS_SUPER_MAGIC;
 144         buf->f_bsize = sbi->blocksize;
 145
 146         buf->f_blocks = total_count - start_count;
 147         buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
 148         buf->f_bavail = user_block_count - valid_user_blocks(sbi);
 149
 150         buf->f_files = sbi->total_node_count;
 151         buf->f_ffree = sbi->total_node_count - valid_inode_count(sbi);
 152
 153         buf->f_namelen = F2FS_MAX_NAME_LEN;
 154         buf->f_fsid.val[0] = (u32)id;
 155         buf->f_fsid.val[1] = (u32)(id >> 32);
 156
 157         return 0;
 158 }
 159
 160 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 161 {
 162         struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
 163
 164         if (test_opt(sbi, BG_GC))
 165                 seq_puts(seq, ",background_gc_on");
 166         else
 167                 seq_puts(seq, ",background_gc_off");
 168         if (test_opt(sbi, DISABLE_ROLL_FORWARD))
 169                 seq_puts(seq, ",disable_roll_forward");
 170         if (test_opt(sbi, DISCARD))
 171                 seq_puts(seq, ",discard");
 172         if (test_opt(sbi, NOHEAP))
 173                 seq_puts(seq, ",no_heap_alloc");
 174 #ifdef CONFIG_F2FS_FS_XATTR
 175         if (test_opt(sbi, XATTR_USER))
 176                 seq_puts(seq, ",user_xattr");
 177         else
 178                 seq_puts(seq, ",nouser_xattr");
 179 #endif
 180 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 181         if (test_opt(sbi, POSIX_ACL))
 182                 seq_puts(seq, ",acl");
 183         else
 184                 seq_puts(seq, ",noacl");
 185 #endif
 186         if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
 187                 seq_puts(seq, ",disable_ext_indentify");
 188
 189         seq_printf(seq, ",active_logs=%u", sbi->active_logs);
 190
 191         return 0;
 192 }
 193
 194 static struct super_operations f2fs_sops = {
 195         .alloc_inode    = f2fs_alloc_inode,
 196         .destroy_inode  = f2fs_destroy_inode,
 197         .write_inode    = f2fs_write_inode,
 198         .show_options   = f2fs_show_options,
 199         .evict_inode    = f2fs_evict_inode,
 200         .put_super      = f2fs_put_super,
 201         .sync_fs        = f2fs_sync_fs,
 202         .statfs         = f2fs_statfs,
 203 };
 204
 205 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
 206                 u64 ino, u32 generation)
 207 {
 208         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 209         struct inode *inode;
 210
 211         if (ino < F2FS_ROOT_INO(sbi))
 212                 return ERR_PTR(-ESTALE);
 213
 214         /*
 215          * f2fs_iget isn't quite right if the inode is currently unallocated!
 216          * However f2fs_iget currently does appropriate checks to handle stale
 217          * inodes so everything is OK.
 218          */
 219         inode = f2fs_iget(sb, ino);
 220         if (IS_ERR(inode))
 221                 return ERR_CAST(inode);
 222         if (generation && inode->i_generation != generation) {
 223                 /* we didn't find the right inode.. */
 224                 iput(inode);
 225                 return ERR_PTR(-ESTALE);
 226         }
 227         return inode;
 228 }
 229
 230 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 231                 int fh_len, int fh_type)
 232 {
 233         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 234                                     f2fs_nfs_get_inode);
 235 }
 236
 237 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
 238                 int fh_len, int fh_type)
 239 {
 240         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 241                                     f2fs_nfs_get_inode);
 242 }
 243
 244 static const struct export_operations f2fs_export_ops = {
 245         .fh_to_dentry = f2fs_fh_to_dentry,
 246         .fh_to_parent = f2fs_fh_to_parent,
 247         .get_parent = f2fs_get_parent,
 248 };
 249
 250 static int parse_options(struct f2fs_sb_info *sbi, char *options)
 251 {
 252         substring_t args[MAX_OPT_ARGS];
 253         char *p;
 254         int arg = 0;
 255
 256         if (!options)
 257                 return 0;
 258
 259         while ((p = strsep(&options, ",")) != NULL) {
 260                 int token;
 261                 if (!*p)
 262                         continue;
 263                 /*
 264                  * Initialize args struct so we know whether arg was
 265                  * found; some options take optional arguments.
 266                  */
 267                 args[0].to = args[0].from = NULL;
 268                 token = match_token(p, f2fs_tokens, args);
 269
 270                 switch (token) {
 271                 case Opt_gc_background_off:
 272                         clear_opt(sbi, BG_GC);
 273                         break;
 274                 case Opt_disable_roll_forward:
 275                         set_opt(sbi, DISABLE_ROLL_FORWARD);
 276                         break;
 277                 case Opt_discard:
 278                         set_opt(sbi, DISCARD);
 279                         break;
 280                 case Opt_noheap:
 281                         set_opt(sbi, NOHEAP);
 282                         break;
 283 #ifdef CONFIG_F2FS_FS_XATTR
 284                 case Opt_nouser_xattr:
 285                         clear_opt(sbi, XATTR_USER);
 286                         break;
 287 #else
 288                 case Opt_nouser_xattr:
 289                         pr_info("nouser_xattr options not supported\n");
 290                         break;
 291 #endif
 292 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 293                 case Opt_noacl:
 294                         clear_opt(sbi, POSIX_ACL);
 295                         break;
 296 #else
 297                 case Opt_noacl:
 298                         pr_info("noacl options not supported\n");
 299                         break;
 300 #endif
 301                 case Opt_active_logs:
 302                         if (args->from && match_int(args, &arg))
 303                                 return -EINVAL;
 304                         if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
 305                                 return -EINVAL;
 306                         sbi->active_logs = arg;
 307                         break;
 308                 case Opt_disable_ext_identify:
 309                         set_opt(sbi, DISABLE_EXT_IDENTIFY);
 310                         break;
 311                 default:
 312                         pr_err("Unrecognized mount option \"%s\" or missing value\n",
 313                                         p);
 314                         return -EINVAL;
 315                 }
 316         }
 317         return 0;
 318 }
 319
 320 static loff_t max_file_size(unsigned bits)
 321 {
 322         loff_t result = ADDRS_PER_INODE;
 323         loff_t leaf_count = ADDRS_PER_BLOCK;
 324
 325         /* two direct node blocks */
 326         result += (leaf_count * 2);
 327
 328         /* two indirect node blocks */
 329         leaf_count *= NIDS_PER_BLOCK;
 330         result += (leaf_count * 2);
 331
 332         /* one double indirect node block */
 333         leaf_count *= NIDS_PER_BLOCK;
 334         result += leaf_count;
 335
 336         result <<= bits;
 337         return result;
 338 }
 339
 340 static int sanity_check_raw_super(struct f2fs_super_block *raw_super)
 341 {
 342         unsigned int blocksize;
 343
 344         if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic))
 345                 return 1;
 346
 347         /* Currently, support only 4KB block size */
 348         blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
 349         if (blocksize != PAGE_CACHE_SIZE)
 350                 return 1;
 351         if (le32_to_cpu(raw_super->log_sectorsize) !=
 352                                         F2FS_LOG_SECTOR_SIZE)
 353                 return 1;
 354         if (le32_to_cpu(raw_super->log_sectors_per_block) !=
 355                                         F2FS_LOG_SECTORS_PER_BLOCK)
 356                 return 1;
 357         return 0;
 358 }
 359
 360 static int sanity_check_ckpt(struct f2fs_super_block *raw_super,
 361                                 struct f2fs_checkpoint *ckpt)
 362 {
 363         unsigned int total, fsmeta;
 364
 365         total = le32_to_cpu(raw_super->segment_count);
 366         fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
 367         fsmeta += le32_to_cpu(raw_super->segment_count_sit);
 368         fsmeta += le32_to_cpu(raw_super->segment_count_nat);
 369         fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
 370         fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
 371
 372         if (fsmeta >= total)
 373                 return 1;
 374         return 0;
 375 }
 376
 377 static void init_sb_info(struct f2fs_sb_info *sbi)
 378 {
 379         struct f2fs_super_block *raw_super = sbi->raw_super;
 380         int i;
 381
 382         sbi->log_sectors_per_block =
 383                 le32_to_cpu(raw_super->log_sectors_per_block);
 384         sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
 385         sbi->blocksize = 1 << sbi->log_blocksize;
 386         sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
 387         sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
 388         sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
 389         sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
 390         sbi->total_sections = le32_to_cpu(raw_super->section_count);
 391         sbi->total_node_count =
 392                 (le32_to_cpu(raw_super->segment_count_nat) / 2)
 393                         * sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
 394         sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
 395         sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
 396         sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
 397
 398         for (i = 0; i < NR_COUNT_TYPE; i++)
 399                 atomic_set(&sbi->nr_pages[i], 0);
 400 }
 401
 402 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 403 {
 404         struct f2fs_sb_info *sbi;
 405         struct f2fs_super_block *raw_super;
 406         struct buffer_head *raw_super_buf;
 407         struct inode *root;
 408         long err = -EINVAL;
 409         int i;
 410
 411         /* allocate memory for f2fs-specific super block info */
 412         sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
 413         if (!sbi)
 414                 return -ENOMEM;
 415
 416         /* set a temporary block size */
 417         if (!sb_set_blocksize(sb, F2FS_BLKSIZE))
 418                 goto free_sbi;
 419
 420         /* read f2fs raw super block */
 421         raw_super_buf = sb_bread(sb, 0);
 422         if (!raw_super_buf) {
 423                 err = -EIO;
 424                 goto free_sbi;
 425         }
 426         raw_super = (struct f2fs_super_block *)
 427                         ((char *)raw_super_buf->b_data + F2FS_SUPER_OFFSET);
 428
 429         /* init some FS parameters */
 430         sbi->active_logs = NR_CURSEG_TYPE;
 431
 432         set_opt(sbi, BG_GC);
 433
 434 #ifdef CONFIG_F2FS_FS_XATTR
 435         set_opt(sbi, XATTR_USER);
 436 #endif
 437 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 438         set_opt(sbi, POSIX_ACL);
 439 #endif
 440         /* parse mount options */
 441         if (parse_options(sbi, (char *)data))
 442                 goto free_sb_buf;
 443
 444         /* sanity checking of raw super */
 445         if (sanity_check_raw_super(raw_super))
 446                 goto free_sb_buf;
 447
 448         sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
 449         sb->s_max_links = F2FS_LINK_MAX;
 450         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 451
 452         sb->s_op = &f2fs_sops;
 453         sb->s_xattr = f2fs_xattr_handlers;
 454         sb->s_export_op = &f2fs_export_ops;
 455         sb->s_magic = F2FS_SUPER_MAGIC;
 456         sb->s_fs_info = sbi;
 457         sb->s_time_gran = 1;
 458         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 459                 (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
 460         memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
 461
 462         /* init f2fs-specific super block info */
 463         sbi->sb = sb;
 464         sbi->raw_super = raw_super;
 465         sbi->raw_super_buf = raw_super_buf;
 466         mutex_init(&sbi->gc_mutex);
 467         mutex_init(&sbi->write_inode);
 468         mutex_init(&sbi->writepages);
 469         mutex_init(&sbi->cp_mutex);
 470         for (i = 0; i < NR_LOCK_TYPE; i++)
 471                 mutex_init(&sbi->fs_lock[i]);
 472         sbi->por_doing = 0;
 473         spin_lock_init(&sbi->stat_lock);
 474         init_rwsem(&sbi->bio_sem);
 475         init_sb_info(sbi);
 476
 477         /* get an inode for meta space */
 478         sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
 479         if (IS_ERR(sbi->meta_inode)) {
 480                 err = PTR_ERR(sbi->meta_inode);
 481                 goto free_sb_buf;
 482         }
 483
 484         err = get_valid_checkpoint(sbi);
 485         if (err)
 486                 goto free_meta_inode;
 487
 488         /* sanity checking of checkpoint */
 489         err = -EINVAL;
 490         if (sanity_check_ckpt(raw_super, sbi->ckpt))
 491                 goto free_cp;
 492
 493         sbi->total_valid_node_count =
 494                                 le32_to_cpu(sbi->ckpt->valid_node_count);
 495         sbi->total_valid_inode_count =
 496                                 le32_to_cpu(sbi->ckpt->valid_inode_count);
 497         sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
 498         sbi->total_valid_block_count =
 499                                 le64_to_cpu(sbi->ckpt->valid_block_count);
 500         sbi->last_valid_block_count = sbi->total_valid_block_count;
 501         sbi->alloc_valid_block_count = 0;
 502         INIT_LIST_HEAD(&sbi->dir_inode_list);
 503         spin_lock_init(&sbi->dir_inode_lock);
 504
 505         /* init super block */
 506         if (!sb_set_blocksize(sb, sbi->blocksize))
 507                 goto free_cp;
 508
 509         init_orphan_info(sbi);
 510
 511         /* setup f2fs internal modules */
 512         err = build_segment_manager(sbi);
 513         if (err)
 514                 goto free_sm;
 515         err = build_node_manager(sbi);
 516         if (err)
 517                 goto free_nm;
 518
 519         build_gc_manager(sbi);
 520
 521         /* get an inode for node space */
 522         sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
 523         if (IS_ERR(sbi->node_inode)) {
 524                 err = PTR_ERR(sbi->node_inode);
 525                 goto free_nm;
 526         }
 527
 528         /* if there are nt orphan nodes free them */
 529         err = -EINVAL;
 530         if (recover_orphan_inodes(sbi))
 531                 goto free_node_inode;
 532
 533         /* read root inode and dentry */
 534         root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
 535         if (IS_ERR(root)) {
 536                 err = PTR_ERR(root);
 537                 goto free_node_inode;
 538         }
 539         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size)
 540                 goto free_root_inode;
 541
 542         sb->s_root = d_make_root(root); /* allocate root dentry */
 543         if (!sb->s_root) {
 544                 err = -ENOMEM;
 545                 goto free_root_inode;
 546         }
 547
 548         /* recover fsynced data */
 549         if (!test_opt(sbi, DISABLE_ROLL_FORWARD))
 550                 recover_fsync_data(sbi);
 551
 552         /* After POR, we can run background GC thread */
 553         err = start_gc_thread(sbi);
 554         if (err)
 555                 goto fail;
 556
 557         err = f2fs_build_stats(sbi);
 558         if (err)
 559                 goto fail;
 560
 561         return 0;
 562 fail:
 563         stop_gc_thread(sbi);
 564 free_root_inode:
 565         dput(sb->s_root);
 566         sb->s_root = NULL;
 567 free_node_inode:
 568         iput(sbi->node_inode);
 569 free_nm:
 570         destroy_node_manager(sbi);
 571 free_sm:
 572         destroy_segment_manager(sbi);
 573 free_cp:
 574         kfree(sbi->ckpt);
 575 free_meta_inode:
 576         make_bad_inode(sbi->meta_inode);
 577         iput(sbi->meta_inode);
 578 free_sb_buf:
 579         brelse(raw_super_buf);
 580 free_sbi:
 581         kfree(sbi);
 582         return err;
 583 }
 584
 585 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
 586                         const char *dev_name, void *data)
 587 {
 588         return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
 589 }
 590
 591 static struct file_system_type f2fs_fs_type = {
 592         .owner          = THIS_MODULE,
 593         .name           = "f2fs",
 594         .mount          = f2fs_mount,
 595         .kill_sb        = kill_block_super,
 596         .fs_flags       = FS_REQUIRES_DEV,
 597 };
 598
 599 static int init_inodecache(void)
 600 {
 601         f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
 602                         sizeof(struct f2fs_inode_info), NULL);
 603         if (f2fs_inode_cachep == NULL)
 604                 return -ENOMEM;
 605         return 0;
 606 }
 607
 608 static void destroy_inodecache(void)
 609 {
 610         /*
 611          * Make sure all delayed rcu free inodes are flushed before we
 612          * destroy cache.
 613          */
 614         rcu_barrier();
 615         kmem_cache_destroy(f2fs_inode_cachep);
 616 }
 617
 618 static int __init init_f2fs_fs(void)
 619 {
 620         int err;
 621
 622         err = init_inodecache();
 623         if (err)
 624                 goto fail;
 625         err = create_node_manager_caches();
 626         if (err)
 627                 goto fail;
 628         err = create_gc_caches();
 629         if (err)
 630                 goto fail;
 631         err = create_checkpoint_caches();
 632         if (err)
 633                 goto fail;
 634         return register_filesystem(&f2fs_fs_type);
 635 fail:
 636         return err;
 637 }
 638
 639 static void __exit exit_f2fs_fs(void)
 640 {
 641         destroy_root_stats();
 642         unregister_filesystem(&f2fs_fs_type);
 643         destroy_checkpoint_caches();
 644         destroy_gc_caches();
 645         destroy_node_manager_caches();
 646         destroy_inodecache();
 647 }
 648
 649 module_init(init_f2fs_fs)
 650 module_exit(exit_f2fs_fs)
 651
 652 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
 653 MODULE_DESCRIPTION("Flash Friendly File System");
 654 MODULE_LICENSE("GPL");