fs/nilfs2/super.c

   1 /*
   2  * super.c - NILFS module and super block management.
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21  */
  22 /*
  23  *  linux/fs/ext2/super.c
  24  *
  25  * Copyright (C) 1992, 1993, 1994, 1995
  26  * Remy Card (card@masi.ibp.fr)
  27  * Laboratoire MASI - Institut Blaise Pascal
  28  * Universite Pierre et Marie Curie (Paris VI)
  29  *
  30  *  from
  31  *
  32  *  linux/fs/minix/inode.c
  33  *
  34  *  Copyright (C) 1991, 1992  Linus Torvalds
  35  *
  36  *  Big-endian to little-endian byte-swapping/bitmaps by
  37  *        David S. Miller (davem@caip.rutgers.edu), 1995
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/string.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/parser.h>
  46 #include <linux/random.h>
  47 #include <linux/crc32.h>
  48 #include <linux/smp_lock.h>
  49 #include <linux/vfs.h>
  50 #include <linux/writeback.h>
  51 #include <linux/kobject.h>
  52 #include <linux/exportfs.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/mount.h>
  55 #include "nilfs.h"
  56 #include "mdt.h"
  57 #include "alloc.h"
  58 #include "page.h"
  59 #include "cpfile.h"
  60 #include "ifile.h"
  61 #include "dat.h"
  62 #include "segment.h"
  63 #include "segbuf.h"
  64
  65 MODULE_AUTHOR("NTT Corp.");
  66 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  67                    "(NILFS)");
  68 MODULE_LICENSE("GPL");
  69
  70 struct kmem_cache *nilfs_inode_cachep;
  71 struct kmem_cache *nilfs_transaction_cachep;
  72 struct kmem_cache *nilfs_segbuf_cachep;
  73 struct kmem_cache *nilfs_btree_path_cache;
  74
  75 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  76
  77 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  78 {
  79         struct the_nilfs *nilfs = sbi->s_nilfs;
  80         struct nilfs_super_block **sbp;
  81
  82         down_write(&nilfs->ns_sem);
  83         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  84                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  85                 sbp = nilfs_prepare_super(sbi);
  86                 if (likely(sbp)) {
  87                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  88                         nilfs_commit_super(sbi, 1);
  89                 }
  90         }
  91         up_write(&nilfs->ns_sem);
  92 }
  93
  94 /**
  95  * nilfs_error() - report failure condition on a filesystem
  96  *
  97  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
  98  * reporting an error message.  It should be called when NILFS detects
  99  * incoherences or defects of meta data on disk.  As for sustainable
 100  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 101  * function should be used instead.
 102  *
 103  * The segment constructor must not call this function because it can
 104  * kill itself.
 105  */
 106 void nilfs_error(struct super_block *sb, const char *function,
 107                  const char *fmt, ...)
 108 {
 109         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 110         va_list args;
 111
 112         va_start(args, fmt);
 113         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 114         vprintk(fmt, args);
 115         printk("\n");
 116         va_end(args);
 117
 118         if (!(sb->s_flags & MS_RDONLY)) {
 119                 nilfs_set_error(sbi);
 120
 121                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 122                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 123                         sb->s_flags |= MS_RDONLY;
 124                 }
 125         }
 126
 127         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 128                 panic("NILFS (device %s): panic forced after error\n",
 129                       sb->s_id);
 130 }
 131
 132 void nilfs_warning(struct super_block *sb, const char *function,
 133                    const char *fmt, ...)
 134 {
 135         va_list args;
 136
 137         va_start(args, fmt);
 138         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 139                sb->s_id, function);
 140         vprintk(fmt, args);
 141         printk("\n");
 142         va_end(args);
 143 }
 144
 145
 146 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 147 {
 148         struct nilfs_inode_info *ii;
 149
 150         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 151         if (!ii)
 152                 return NULL;
 153         ii->i_bh = NULL;
 154         ii->i_state = 0;
 155         ii->vfs_inode.i_version = 1;
 156         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
 157         return &ii->vfs_inode;
 158 }
 159
 160 struct inode *nilfs_alloc_inode(struct super_block *sb)
 161 {
 162         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
 163 }
 164
 165 void nilfs_destroy_inode(struct inode *inode)
 166 {
 167         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 168 }
 169
 170 static void nilfs_clear_inode(struct inode *inode)
 171 {
 172         struct nilfs_inode_info *ii = NILFS_I(inode);
 173
 174         /*
 175          * Free resources allocated in nilfs_read_inode(), here.
 176          */
 177         BUG_ON(!list_empty(&ii->i_dirty));
 178         brelse(ii->i_bh);
 179         ii->i_bh = NULL;
 180
 181         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 182                 nilfs_bmap_clear(ii->i_bmap);
 183
 184         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 185 }
 186
 187 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
 188 {
 189         struct the_nilfs *nilfs = sbi->s_nilfs;
 190         int err;
 191         int barrier_done = 0;
 192
 193         if (nilfs_test_opt(sbi, BARRIER)) {
 194                 set_buffer_ordered(nilfs->ns_sbh[0]);
 195                 barrier_done = 1;
 196         }
 197  retry:
 198         set_buffer_dirty(nilfs->ns_sbh[0]);
 199         err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 200         if (err == -EOPNOTSUPP && barrier_done) {
 201                 nilfs_warning(sbi->s_super, __func__,
 202                               "barrier-based sync failed. "
 203                               "disabling barriers\n");
 204                 nilfs_clear_opt(sbi, BARRIER);
 205                 barrier_done = 0;
 206                 clear_buffer_ordered(nilfs->ns_sbh[0]);
 207                 goto retry;
 208         }
 209         if (unlikely(err)) {
 210                 printk(KERN_ERR
 211                        "NILFS: unable to write superblock (err=%d)\n", err);
 212                 if (err == -EIO && nilfs->ns_sbh[1]) {
 213                         nilfs_fall_back_super_block(nilfs);
 214                         goto retry;
 215                 }
 216         } else {
 217                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 218
 219                 /*
 220                  * The latest segment becomes trailable from the position
 221                  * written in superblock.
 222                  */
 223                 clear_nilfs_discontinued(nilfs);
 224
 225                 /* update GC protection for recent segments */
 226                 if (nilfs->ns_sbh[1]) {
 227                         sbp = NULL;
 228                         if (dupsb) {
 229                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 230                                 if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
 231                                         sbp = nilfs->ns_sbp[1];
 232                         }
 233                 }
 234                 if (sbp) {
 235                         spin_lock(&nilfs->ns_last_segment_lock);
 236                         nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 237                         spin_unlock(&nilfs->ns_last_segment_lock);
 238                 }
 239         }
 240
 241         return err;
 242 }
 243
 244 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 245                           struct the_nilfs *nilfs)
 246 {
 247         sector_t nfreeblocks;
 248
 249         /* nilfs->ns_sem must be locked by the caller. */
 250         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 251         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 252
 253         spin_lock(&nilfs->ns_last_segment_lock);
 254         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 255         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 256         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 257         spin_unlock(&nilfs->ns_last_segment_lock);
 258 }
 259
 260 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi)
 261 {
 262         struct the_nilfs *nilfs = sbi->s_nilfs;
 263         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 264
 265         /* nilfs->ns_sem must be locked by the caller. */
 266         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 267                 if (sbp[1] &&
 268                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 269                         nilfs_swap_super_block(nilfs);
 270                 } else {
 271                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 272                                sbi->s_super->s_id);
 273                         return NULL;
 274                 }
 275         }
 276         return sbp;
 277 }
 278
 279 int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
 280 {
 281         struct the_nilfs *nilfs = sbi->s_nilfs;
 282         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 283         time_t t;
 284
 285         /* nilfs->ns_sem must be locked by the caller. */
 286         nilfs_set_log_cursor(sbp[0], nilfs);
 287
 288         t = get_seconds();
 289         nilfs->ns_sbwtime[0] = t;
 290         sbp[0]->s_wtime = cpu_to_le64(t);
 291         sbp[0]->s_sum = 0;
 292         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 293                                              (unsigned char *)sbp[0],
 294                                              nilfs->ns_sbsize));
 295         if (dupsb && sbp[1]) {
 296                 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 297                 nilfs->ns_sbwtime[1] = t;
 298         }
 299         clear_nilfs_sb_dirty(nilfs);
 300         return nilfs_sync_super(sbi, dupsb);
 301 }
 302
 303 /**
 304  * nilfs_cleanup_super() - write filesystem state for cleanup
 305  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 306  *
 307  * This function restores state flags in the on-disk super block.
 308  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 309  * filesystem was not clean previously.
 310  */
 311 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 312 {
 313         struct nilfs_super_block **sbp;
 314         int ret = -EIO;
 315
 316         sbp = nilfs_prepare_super(sbi);
 317         if (sbp) {
 318                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 319                 ret = nilfs_commit_super(sbi, 1);
 320         }
 321         return ret;
 322 }
 323
 324 static void nilfs_put_super(struct super_block *sb)
 325 {
 326         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 327         struct the_nilfs *nilfs = sbi->s_nilfs;
 328
 329         lock_kernel();
 330
 331         nilfs_detach_segment_constructor(sbi);
 332
 333         if (!(sb->s_flags & MS_RDONLY)) {
 334                 down_write(&nilfs->ns_sem);
 335                 nilfs_cleanup_super(sbi);
 336                 up_write(&nilfs->ns_sem);
 337         }
 338         down_write(&nilfs->ns_super_sem);
 339         if (nilfs->ns_current == sbi)
 340                 nilfs->ns_current = NULL;
 341         up_write(&nilfs->ns_super_sem);
 342
 343         nilfs_detach_checkpoint(sbi);
 344         put_nilfs(sbi->s_nilfs);
 345         sbi->s_super = NULL;
 346         sb->s_fs_info = NULL;
 347         nilfs_put_sbinfo(sbi);
 348
 349         unlock_kernel();
 350 }
 351
 352 static int nilfs_sync_fs(struct super_block *sb, int wait)
 353 {
 354         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 355         struct the_nilfs *nilfs = sbi->s_nilfs;
 356         struct nilfs_super_block **sbp;
 357         int err = 0;
 358
 359         /* This function is called when super block should be written back */
 360         if (wait)
 361                 err = nilfs_construct_segment(sb);
 362
 363         down_write(&nilfs->ns_sem);
 364         if (nilfs_sb_dirty(nilfs)) {
 365                 sbp = nilfs_prepare_super(sbi);
 366                 if (likely(sbp))
 367                         nilfs_commit_super(sbi, 1);
 368         }
 369         up_write(&nilfs->ns_sem);
 370
 371         return err;
 372 }
 373
 374 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
 375 {
 376         struct the_nilfs *nilfs = sbi->s_nilfs;
 377         struct nilfs_checkpoint *raw_cp;
 378         struct buffer_head *bh_cp;
 379         int err;
 380
 381         down_write(&nilfs->ns_super_sem);
 382         list_add(&sbi->s_list, &nilfs->ns_supers);
 383         up_write(&nilfs->ns_super_sem);
 384
 385         sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
 386         if (!sbi->s_ifile)
 387                 return -ENOMEM;
 388
 389         down_read(&nilfs->ns_segctor_sem);
 390         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 391                                           &bh_cp);
 392         up_read(&nilfs->ns_segctor_sem);
 393         if (unlikely(err)) {
 394                 if (err == -ENOENT || err == -EINVAL) {
 395                         printk(KERN_ERR
 396                                "NILFS: Invalid checkpoint "
 397                                "(checkpoint number=%llu)\n",
 398                                (unsigned long long)cno);
 399                         err = -EINVAL;
 400                 }
 401                 goto failed;
 402         }
 403         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
 404         if (unlikely(err))
 405                 goto failed_bh;
 406         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 407         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 408
 409         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 410         return 0;
 411
 412  failed_bh:
 413         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 414  failed:
 415         nilfs_mdt_destroy(sbi->s_ifile);
 416         sbi->s_ifile = NULL;
 417
 418         down_write(&nilfs->ns_super_sem);
 419         list_del_init(&sbi->s_list);
 420         up_write(&nilfs->ns_super_sem);
 421
 422         return err;
 423 }
 424
 425 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
 426 {
 427         struct the_nilfs *nilfs = sbi->s_nilfs;
 428
 429         nilfs_mdt_destroy(sbi->s_ifile);
 430         sbi->s_ifile = NULL;
 431         down_write(&nilfs->ns_super_sem);
 432         list_del_init(&sbi->s_list);
 433         up_write(&nilfs->ns_super_sem);
 434 }
 435
 436 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 437 {
 438         struct super_block *sb = dentry->d_sb;
 439         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 440         struct the_nilfs *nilfs = sbi->s_nilfs;
 441         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 442         unsigned long long blocks;
 443         unsigned long overhead;
 444         unsigned long nrsvblocks;
 445         sector_t nfreeblocks;
 446         int err;
 447
 448         /*
 449          * Compute all of the segment blocks
 450          *
 451          * The blocks before first segment and after last segment
 452          * are excluded.
 453          */
 454         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 455                 - nilfs->ns_first_data_block;
 456         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 457
 458         /*
 459          * Compute the overhead
 460          *
 461          * When distributing meta data blocks outside segment structure,
 462          * We must count them as the overhead.
 463          */
 464         overhead = 0;
 465
 466         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 467         if (unlikely(err))
 468                 return err;
 469
 470         buf->f_type = NILFS_SUPER_MAGIC;
 471         buf->f_bsize = sb->s_blocksize;
 472         buf->f_blocks = blocks - overhead;
 473         buf->f_bfree = nfreeblocks;
 474         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 475                 (buf->f_bfree - nrsvblocks) : 0;
 476         buf->f_files = atomic_read(&sbi->s_inodes_count);
 477         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 478         buf->f_namelen = NILFS_NAME_LEN;
 479         buf->f_fsid.val[0] = (u32)id;
 480         buf->f_fsid.val[1] = (u32)(id >> 32);
 481
 482         return 0;
 483 }
 484
 485 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 486 {
 487         struct super_block *sb = vfs->mnt_sb;
 488         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 489
 490         if (!nilfs_test_opt(sbi, BARRIER))
 491                 seq_printf(seq, ",nobarrier");
 492         if (nilfs_test_opt(sbi, SNAPSHOT))
 493                 seq_printf(seq, ",cp=%llu",
 494                            (unsigned long long int)sbi->s_snapshot_cno);
 495         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 496                 seq_printf(seq, ",errors=panic");
 497         if (nilfs_test_opt(sbi, ERRORS_CONT))
 498                 seq_printf(seq, ",errors=continue");
 499         if (nilfs_test_opt(sbi, STRICT_ORDER))
 500                 seq_printf(seq, ",order=strict");
 501         if (nilfs_test_opt(sbi, NORECOVERY))
 502                 seq_printf(seq, ",norecovery");
 503         if (nilfs_test_opt(sbi, DISCARD))
 504                 seq_printf(seq, ",discard");
 505
 506         return 0;
 507 }
 508
 509 static const struct super_operations nilfs_sops = {
 510         .alloc_inode    = nilfs_alloc_inode,
 511         .destroy_inode  = nilfs_destroy_inode,
 512         .dirty_inode    = nilfs_dirty_inode,
 513         /* .write_inode    = nilfs_write_inode, */
 514         /* .put_inode      = nilfs_put_inode, */
 515         /* .drop_inode    = nilfs_drop_inode, */
 516         .delete_inode   = nilfs_delete_inode,
 517         .put_super      = nilfs_put_super,
 518         /* .write_super    = nilfs_write_super, */
 519         .sync_fs        = nilfs_sync_fs,
 520         /* .write_super_lockfs */
 521         /* .unlockfs */
 522         .statfs         = nilfs_statfs,
 523         .remount_fs     = nilfs_remount,
 524         .clear_inode    = nilfs_clear_inode,
 525         /* .umount_begin */
 526         .show_options = nilfs_show_options
 527 };
 528
 529 static struct inode *
 530 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 531 {
 532         struct inode *inode;
 533
 534         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
 535             ino != NILFS_SKETCH_INO)
 536                 return ERR_PTR(-ESTALE);
 537
 538         inode = nilfs_iget(sb, ino);
 539         if (IS_ERR(inode))
 540                 return ERR_CAST(inode);
 541         if (generation && inode->i_generation != generation) {
 542                 iput(inode);
 543                 return ERR_PTR(-ESTALE);
 544         }
 545
 546         return inode;
 547 }
 548
 549 static struct dentry *
 550 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
 551                    int fh_type)
 552 {
 553         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 554                                     nilfs_nfs_get_inode);
 555 }
 556
 557 static struct dentry *
 558 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
 559                    int fh_type)
 560 {
 561         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 562                                     nilfs_nfs_get_inode);
 563 }
 564
 565 static const struct export_operations nilfs_export_ops = {
 566         .fh_to_dentry = nilfs_fh_to_dentry,
 567         .fh_to_parent = nilfs_fh_to_parent,
 568         .get_parent = nilfs_get_parent,
 569 };
 570
 571 enum {
 572         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 573         Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 574         Opt_discard, Opt_err,
 575 };
 576
 577 static match_table_t tokens = {
 578         {Opt_err_cont, "errors=continue"},
 579         {Opt_err_panic, "errors=panic"},
 580         {Opt_err_ro, "errors=remount-ro"},
 581         {Opt_nobarrier, "nobarrier"},
 582         {Opt_snapshot, "cp=%u"},
 583         {Opt_order, "order=%s"},
 584         {Opt_norecovery, "norecovery"},
 585         {Opt_discard, "discard"},
 586         {Opt_err, NULL}
 587 };
 588
 589 static int parse_options(char *options, struct super_block *sb)
 590 {
 591         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 592         char *p;
 593         substring_t args[MAX_OPT_ARGS];
 594         int option;
 595
 596         if (!options)
 597                 return 1;
 598
 599         while ((p = strsep(&options, ",")) != NULL) {
 600                 int token;
 601                 if (!*p)
 602                         continue;
 603
 604                 token = match_token(p, tokens, args);
 605                 switch (token) {
 606                 case Opt_nobarrier:
 607                         nilfs_clear_opt(sbi, BARRIER);
 608                         break;
 609                 case Opt_order:
 610                         if (strcmp(args[0].from, "relaxed") == 0)
 611                                 /* Ordered data semantics */
 612                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 613                         else if (strcmp(args[0].from, "strict") == 0)
 614                                 /* Strict in-order semantics */
 615                                 nilfs_set_opt(sbi, STRICT_ORDER);
 616                         else
 617                                 return 0;
 618                         break;
 619                 case Opt_err_panic:
 620                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 621                         break;
 622                 case Opt_err_ro:
 623                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 624                         break;
 625                 case Opt_err_cont:
 626                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 627                         break;
 628                 case Opt_snapshot:
 629                         if (match_int(&args[0], &option) || option <= 0)
 630                                 return 0;
 631                         if (!(sb->s_flags & MS_RDONLY))
 632                                 return 0;
 633                         sbi->s_snapshot_cno = option;
 634                         nilfs_set_opt(sbi, SNAPSHOT);
 635                         break;
 636                 case Opt_norecovery:
 637                         nilfs_set_opt(sbi, NORECOVERY);
 638                         break;
 639                 case Opt_discard:
 640                         nilfs_set_opt(sbi, DISCARD);
 641                         break;
 642                 default:
 643                         printk(KERN_ERR
 644                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 645                         return 0;
 646                 }
 647         }
 648         return 1;
 649 }
 650
 651 static inline void
 652 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 653                           struct nilfs_super_block *sbp)
 654 {
 655         sbi->s_mount_opt =
 656                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 657 }
 658
 659 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 660 {
 661         struct the_nilfs *nilfs = sbi->s_nilfs;
 662         struct nilfs_super_block **sbp;
 663         int max_mnt_count;
 664         int mnt_count;
 665
 666         /* nilfs->ns_sem must be locked by the caller. */
 667         sbp = nilfs_prepare_super(sbi);
 668         if (!sbp)
 669                 return -EIO;
 670
 671         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 672         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 673
 674         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 675                 printk(KERN_WARNING
 676                        "NILFS warning: mounting fs with errors\n");
 677 #if 0
 678         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 679                 printk(KERN_WARNING
 680                        "NILFS warning: maximal mount count reached\n");
 681 #endif
 682         }
 683         if (!max_mnt_count)
 684                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 685
 686         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 687         sbp[0]->s_state =
 688                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 689         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 690         return nilfs_commit_super(sbi, 1);
 691 }
 692
 693 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 694                                                  u64 pos, int blocksize,
 695                                                  struct buffer_head **pbh)
 696 {
 697         unsigned long long sb_index = pos;
 698         unsigned long offset;
 699
 700         offset = do_div(sb_index, blocksize);
 701         *pbh = sb_bread(sb, sb_index);
 702         if (!*pbh)
 703                 return NULL;
 704         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 705 }
 706
 707 int nilfs_store_magic_and_option(struct super_block *sb,
 708                                  struct nilfs_super_block *sbp,
 709                                  char *data)
 710 {
 711         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 712
 713         sb->s_magic = le16_to_cpu(sbp->s_magic);
 714
 715         /* FS independent flags */
 716 #ifdef NILFS_ATIME_DISABLE
 717         sb->s_flags |= MS_NOATIME;
 718 #endif
 719
 720         nilfs_set_default_options(sbi, sbp);
 721
 722         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 723         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 724         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 725         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 726
 727         return !parse_options(data, sb) ? -EINVAL : 0 ;
 728 }
 729
 730 /**
 731  * nilfs_fill_super() - initialize a super block instance
 732  * @sb: super_block
 733  * @data: mount options
 734  * @silent: silent mode flag
 735  * @nilfs: the_nilfs struct
 736  *
 737  * This function is called exclusively by nilfs->ns_mount_mutex.
 738  * So, the recovery process is protected from other simultaneous mounts.
 739  */
 740 static int
 741 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 742                  struct the_nilfs *nilfs)
 743 {
 744         struct nilfs_sb_info *sbi;
 745         struct inode *root;
 746         __u64 cno;
 747         int err;
 748
 749         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 750         if (!sbi)
 751                 return -ENOMEM;
 752
 753         sb->s_fs_info = sbi;
 754
 755         get_nilfs(nilfs);
 756         sbi->s_nilfs = nilfs;
 757         sbi->s_super = sb;
 758         atomic_set(&sbi->s_count, 1);
 759
 760         err = init_nilfs(nilfs, sbi, (char *)data);
 761         if (err)
 762                 goto failed_sbi;
 763
 764         spin_lock_init(&sbi->s_inode_lock);
 765         INIT_LIST_HEAD(&sbi->s_dirty_files);
 766         INIT_LIST_HEAD(&sbi->s_list);
 767
 768         /*
 769          * Following initialization is overlapped because
 770          * nilfs_sb_info structure has been cleared at the beginning.
 771          * But we reserve them to keep our interest and make ready
 772          * for the future change.
 773          */
 774         get_random_bytes(&sbi->s_next_generation,
 775                          sizeof(sbi->s_next_generation));
 776         spin_lock_init(&sbi->s_next_gen_lock);
 777
 778         sb->s_op = &nilfs_sops;
 779         sb->s_export_op = &nilfs_export_ops;
 780         sb->s_root = NULL;
 781         sb->s_time_gran = 1;
 782         sb->s_bdi = nilfs->ns_bdi;
 783
 784         err = load_nilfs(nilfs, sbi);
 785         if (err)
 786                 goto failed_sbi;
 787
 788         cno = nilfs_last_cno(nilfs);
 789
 790         if (sb->s_flags & MS_RDONLY) {
 791                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 792                         down_read(&nilfs->ns_segctor_sem);
 793                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
 794                                                        sbi->s_snapshot_cno);
 795                         up_read(&nilfs->ns_segctor_sem);
 796                         if (err < 0) {
 797                                 if (err == -ENOENT)
 798                                         err = -EINVAL;
 799                                 goto failed_sbi;
 800                         }
 801                         if (!err) {
 802                                 printk(KERN_ERR
 803                                        "NILFS: The specified checkpoint is "
 804                                        "not a snapshot "
 805                                        "(checkpoint number=%llu).\n",
 806                                        (unsigned long long)sbi->s_snapshot_cno);
 807                                 err = -EINVAL;
 808                                 goto failed_sbi;
 809                         }
 810                         cno = sbi->s_snapshot_cno;
 811                 }
 812         }
 813
 814         err = nilfs_attach_checkpoint(sbi, cno);
 815         if (err) {
 816                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 817                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 818                 goto failed_sbi;
 819         }
 820
 821         if (!(sb->s_flags & MS_RDONLY)) {
 822                 err = nilfs_attach_segment_constructor(sbi);
 823                 if (err)
 824                         goto failed_checkpoint;
 825         }
 826
 827         root = nilfs_iget(sb, NILFS_ROOT_INO);
 828         if (IS_ERR(root)) {
 829                 printk(KERN_ERR "NILFS: get root inode failed\n");
 830                 err = PTR_ERR(root);
 831                 goto failed_segctor;
 832         }
 833         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 834                 iput(root);
 835                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 836                 err = -EINVAL;
 837                 goto failed_segctor;
 838         }
 839         sb->s_root = d_alloc_root(root);
 840         if (!sb->s_root) {
 841                 iput(root);
 842                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 843                 err = -ENOMEM;
 844                 goto failed_segctor;
 845         }
 846
 847         if (!(sb->s_flags & MS_RDONLY)) {
 848                 down_write(&nilfs->ns_sem);
 849                 nilfs_setup_super(sbi);
 850                 up_write(&nilfs->ns_sem);
 851         }
 852
 853         down_write(&nilfs->ns_super_sem);
 854         if (!nilfs_test_opt(sbi, SNAPSHOT))
 855                 nilfs->ns_current = sbi;
 856         up_write(&nilfs->ns_super_sem);
 857
 858         return 0;
 859
 860  failed_segctor:
 861         nilfs_detach_segment_constructor(sbi);
 862
 863  failed_checkpoint:
 864         nilfs_detach_checkpoint(sbi);
 865
 866  failed_sbi:
 867         put_nilfs(nilfs);
 868         sb->s_fs_info = NULL;
 869         nilfs_put_sbinfo(sbi);
 870         return err;
 871 }
 872
 873 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 874 {
 875         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 876         struct the_nilfs *nilfs = sbi->s_nilfs;
 877         unsigned long old_sb_flags;
 878         struct nilfs_mount_options old_opts;
 879         int was_snapshot, err;
 880
 881         lock_kernel();
 882
 883         down_write(&nilfs->ns_super_sem);
 884         old_sb_flags = sb->s_flags;
 885         old_opts.mount_opt = sbi->s_mount_opt;
 886         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 887         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 888
 889         if (!parse_options(data, sb)) {
 890                 err = -EINVAL;
 891                 goto restore_opts;
 892         }
 893         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 894
 895         err = -EINVAL;
 896         if (was_snapshot) {
 897                 if (!(*flags & MS_RDONLY)) {
 898                         printk(KERN_ERR "NILFS (device %s): cannot remount "
 899                                "snapshot read/write.\n",
 900                                sb->s_id);
 901                         goto restore_opts;
 902                 } else if (sbi->s_snapshot_cno != old_opts.snapshot_cno) {
 903                         printk(KERN_ERR "NILFS (device %s): cannot "
 904                                "remount to a different snapshot.\n",
 905                                sb->s_id);
 906                         goto restore_opts;
 907                 }
 908         } else {
 909                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 910                         printk(KERN_ERR "NILFS (device %s): cannot change "
 911                                "a regular mount to a snapshot.\n",
 912                                sb->s_id);
 913                         goto restore_opts;
 914                 }
 915         }
 916
 917         if (!nilfs_valid_fs(nilfs)) {
 918                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 919                        "remount because the filesystem is in an "
 920                        "incomplete recovery state.\n", sb->s_id);
 921                 goto restore_opts;
 922         }
 923
 924         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 925                 goto out;
 926         if (*flags & MS_RDONLY) {
 927                 /* Shutting down the segment constructor */
 928                 nilfs_detach_segment_constructor(sbi);
 929                 sb->s_flags |= MS_RDONLY;
 930
 931                 /*
 932                  * Remounting a valid RW partition RDONLY, so set
 933                  * the RDONLY flag and then mark the partition as valid again.
 934                  */
 935                 down_write(&nilfs->ns_sem);
 936                 nilfs_cleanup_super(sbi);
 937                 up_write(&nilfs->ns_sem);
 938         } else {
 939                 /*
 940                  * Mounting a RDONLY partition read-write, so reread and
 941                  * store the current valid flag.  (It may have been changed
 942                  * by fsck since we originally mounted the partition.)
 943                  */
 944                 sb->s_flags &= ~MS_RDONLY;
 945
 946                 err = nilfs_attach_segment_constructor(sbi);
 947                 if (err)
 948                         goto restore_opts;
 949
 950                 down_write(&nilfs->ns_sem);
 951                 nilfs_setup_super(sbi);
 952                 up_write(&nilfs->ns_sem);
 953         }
 954  out:
 955         up_write(&nilfs->ns_super_sem);
 956         unlock_kernel();
 957         return 0;
 958
 959  restore_opts:
 960         sb->s_flags = old_sb_flags;
 961         sbi->s_mount_opt = old_opts.mount_opt;
 962         sbi->s_snapshot_cno = old_opts.snapshot_cno;
 963         up_write(&nilfs->ns_super_sem);
 964         unlock_kernel();
 965         return err;
 966 }
 967
 968 struct nilfs_super_data {
 969         struct block_device *bdev;
 970         struct nilfs_sb_info *sbi;
 971         __u64 cno;
 972         int flags;
 973 };
 974
 975 /**
 976  * nilfs_identify - pre-read mount options needed to identify mount instance
 977  * @data: mount options
 978  * @sd: nilfs_super_data
 979  */
 980 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
 981 {
 982         char *p, *options = data;
 983         substring_t args[MAX_OPT_ARGS];
 984         int option, token;
 985         int ret = 0;
 986
 987         do {
 988                 p = strsep(&options, ",");
 989                 if (p != NULL && *p) {
 990                         token = match_token(p, tokens, args);
 991                         if (token == Opt_snapshot) {
 992                                 if (!(sd->flags & MS_RDONLY))
 993                                         ret++;
 994                                 else {
 995                                         ret = match_int(&args[0], &option);
 996                                         if (!ret) {
 997                                                 if (option > 0)
 998                                                         sd->cno = option;
 999                                                 else
1000                                                         ret++;
1001                                         }
1002                                 }
1003                         }
1004                         if (ret)
1005                                 printk(KERN_ERR
1006                                        "NILFS: invalid mount option: %s\n", p);
1007                 }
1008                 if (!options)
1009                         break;
1010                 BUG_ON(options == data);
1011                 *(options - 1) = ',';
1012         } while (!ret);
1013         return ret;
1014 }
1015
1016 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1017 {
1018         struct nilfs_super_data *sd = data;
1019
1020         s->s_bdev = sd->bdev;
1021         s->s_dev = s->s_bdev->bd_dev;
1022         return 0;
1023 }
1024
1025 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1026 {
1027         struct nilfs_super_data *sd = data;
1028
1029         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1030 }
1031
1032 static int
1033 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1034              const char *dev_name, void *data, struct vfsmount *mnt)
1035 {
1036         struct nilfs_super_data sd;
1037         struct super_block *s;
1038         fmode_t mode = FMODE_READ;
1039         struct the_nilfs *nilfs;
1040         int err, need_to_close = 1;
1041
1042         if (!(flags & MS_RDONLY))
1043                 mode |= FMODE_WRITE;
1044
1045         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1046         if (IS_ERR(sd.bdev))
1047                 return PTR_ERR(sd.bdev);
1048
1049         /*
1050          * To get mount instance using sget() vfs-routine, NILFS needs
1051          * much more information than normal filesystems to identify mount
1052          * instance.  For snapshot mounts, not only a mount type (ro-mount
1053          * or rw-mount) but also a checkpoint number is required.
1054          */
1055         sd.cno = 0;
1056         sd.flags = flags;
1057         if (nilfs_identify((char *)data, &sd)) {
1058                 err = -EINVAL;
1059                 goto failed;
1060         }
1061
1062         nilfs = find_or_create_nilfs(sd.bdev);
1063         if (!nilfs) {
1064                 err = -ENOMEM;
1065                 goto failed;
1066         }
1067
1068         mutex_lock(&nilfs->ns_mount_mutex);
1069
1070         if (!sd.cno) {
1071                 /*
1072                  * Check if an exclusive mount exists or not.
1073                  * Snapshot mounts coexist with a current mount
1074                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1075                  * ro-mount are mutually exclusive.
1076                  */
1077                 down_read(&nilfs->ns_super_sem);
1078                 if (nilfs->ns_current &&
1079                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1080                      & MS_RDONLY)) {
1081                         up_read(&nilfs->ns_super_sem);
1082                         err = -EBUSY;
1083                         goto failed_unlock;
1084                 }
1085                 up_read(&nilfs->ns_super_sem);
1086         }
1087
1088         /*
1089          * Find existing nilfs_sb_info struct
1090          */
1091         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1092
1093         /*
1094          * Get super block instance holding the nilfs_sb_info struct.
1095          * A new instance is allocated if no existing mount is present or
1096          * existing instance has been unmounted.
1097          */
1098         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1099         if (sd.sbi)
1100                 nilfs_put_sbinfo(sd.sbi);
1101
1102         if (IS_ERR(s)) {
1103                 err = PTR_ERR(s);
1104                 goto failed_unlock;
1105         }
1106
1107         if (!s->s_root) {
1108                 char b[BDEVNAME_SIZE];
1109
1110                 /* New superblock instance created */
1111                 s->s_flags = flags;
1112                 s->s_mode = mode;
1113                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1114                 sb_set_blocksize(s, block_size(sd.bdev));
1115
1116                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1117                                        nilfs);
1118                 if (err)
1119                         goto cancel_new;
1120
1121                 s->s_flags |= MS_ACTIVE;
1122                 need_to_close = 0;
1123         }
1124
1125         mutex_unlock(&nilfs->ns_mount_mutex);
1126         put_nilfs(nilfs);
1127         if (need_to_close)
1128                 close_bdev_exclusive(sd.bdev, mode);
1129         simple_set_mnt(mnt, s);
1130         return 0;
1131
1132  failed_unlock:
1133         mutex_unlock(&nilfs->ns_mount_mutex);
1134         put_nilfs(nilfs);
1135  failed:
1136         close_bdev_exclusive(sd.bdev, mode);
1137
1138         return err;
1139
1140  cancel_new:
1141         /* Abandoning the newly allocated superblock */
1142         mutex_unlock(&nilfs->ns_mount_mutex);
1143         put_nilfs(nilfs);
1144         deactivate_locked_super(s);
1145         /*
1146          * deactivate_locked_super() invokes close_bdev_exclusive().
1147          * We must finish all post-cleaning before this call;
1148          * put_nilfs() needs the block device.
1149          */
1150         return err;
1151 }
1152
1153 struct file_system_type nilfs_fs_type = {
1154         .owner    = THIS_MODULE,
1155         .name     = "nilfs2",
1156         .get_sb   = nilfs_get_sb,
1157         .kill_sb  = kill_block_super,
1158         .fs_flags = FS_REQUIRES_DEV,
1159 };
1160
1161 static void nilfs_inode_init_once(void *obj)
1162 {
1163         struct nilfs_inode_info *ii = obj;
1164
1165         INIT_LIST_HEAD(&ii->i_dirty);
1166 #ifdef CONFIG_NILFS_XATTR
1167         init_rwsem(&ii->xattr_sem);
1168 #endif
1169         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1170         ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
1171         inode_init_once(&ii->vfs_inode);
1172 }
1173
1174 static void nilfs_segbuf_init_once(void *obj)
1175 {
1176         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1177 }
1178
1179 static void nilfs_destroy_cachep(void)
1180 {
1181         if (nilfs_inode_cachep)
1182                 kmem_cache_destroy(nilfs_inode_cachep);
1183         if (nilfs_transaction_cachep)
1184                 kmem_cache_destroy(nilfs_transaction_cachep);
1185         if (nilfs_segbuf_cachep)
1186                 kmem_cache_destroy(nilfs_segbuf_cachep);
1187         if (nilfs_btree_path_cache)
1188                 kmem_cache_destroy(nilfs_btree_path_cache);
1189 }
1190
1191 static int __init nilfs_init_cachep(void)
1192 {
1193         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1194                         sizeof(struct nilfs_inode_info), 0,
1195                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1196         if (!nilfs_inode_cachep)
1197                 goto fail;
1198
1199         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1200                         sizeof(struct nilfs_transaction_info), 0,
1201                         SLAB_RECLAIM_ACCOUNT, NULL);
1202         if (!nilfs_transaction_cachep)
1203                 goto fail;
1204
1205         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1206                         sizeof(struct nilfs_segment_buffer), 0,
1207                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1208         if (!nilfs_segbuf_cachep)
1209                 goto fail;
1210
1211         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1212                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1213                         0, 0, NULL);
1214         if (!nilfs_btree_path_cache)
1215                 goto fail;
1216
1217         return 0;
1218
1219 fail:
1220         nilfs_destroy_cachep();
1221         return -ENOMEM;
1222 }
1223
1224 static int __init init_nilfs_fs(void)
1225 {
1226         int err;
1227
1228         err = nilfs_init_cachep();
1229         if (err)
1230                 goto fail;
1231
1232         err = register_filesystem(&nilfs_fs_type);
1233         if (err)
1234                 goto free_cachep;
1235
1236         printk(KERN_INFO "NILFS version 2 loaded\n");
1237         return 0;
1238
1239 free_cachep:
1240         nilfs_destroy_cachep();
1241 fail:
1242         return err;
1243 }
1244
1245 static void __exit exit_nilfs_fs(void)
1246 {
1247         nilfs_destroy_cachep();
1248         unregister_filesystem(&nilfs_fs_type);
1249 }
1250
1251 module_init(init_nilfs_fs)
1252 module_exit(exit_nilfs_fs)