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   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 static void nilfs_write_super(struct super_block *sb);
  71 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  72
  73 /**
  74  * nilfs_error() - report failure condition on a filesystem
  75  *
  76  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
  77  * reporting an error message.  It should be called when NILFS detects
  78  * incoherences or defects of meta data on disk.  As for sustainable
  79  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
  80  * function should be used instead.
  81  *
  82  * The segment constructor must not call this function because it can
  83  * kill itself.
  84  */
  85 void nilfs_error(struct super_block *sb, const char *function,
  86                  const char *fmt, ...)
  87 {
  88         struct nilfs_sb_info *sbi = NILFS_SB(sb);
  89         va_list args;
  90
  91         va_start(args, fmt);
  92         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
  93         vprintk(fmt, args);
  94         printk("\n");
  95         va_end(args);
  96
  97         if (!(sb->s_flags & MS_RDONLY)) {
  98                 struct the_nilfs *nilfs = sbi->s_nilfs;
  99
 100                 if (!nilfs_test_opt(sbi, ERRORS_CONT))
 101                         nilfs_detach_segment_constructor(sbi);
 102
 103                 down_write(&nilfs->ns_sem);
 104                 if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
 105                         nilfs->ns_mount_state |= NILFS_ERROR_FS;
 106                         nilfs->ns_sbp[0]->s_state |=
 107                                 cpu_to_le16(NILFS_ERROR_FS);
 108                         nilfs_commit_super(sbi, 1);
 109                 }
 110                 up_write(&nilfs->ns_sem);
 111
 112                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 113                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 114                         sb->s_flags |= MS_RDONLY;
 115                 }
 116         }
 117
 118         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 119                 panic("NILFS (device %s): panic forced after error\n",
 120                       sb->s_id);
 121 }
 122
 123 void nilfs_warning(struct super_block *sb, const char *function,
 124                    const char *fmt, ...)
 125 {
 126         va_list args;
 127
 128         va_start(args, fmt);
 129         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 130                sb->s_id, function);
 131         vprintk(fmt, args);
 132         printk("\n");
 133         va_end(args);
 134 }
 135
 136 static struct kmem_cache *nilfs_inode_cachep;
 137
 138 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 139 {
 140         struct nilfs_inode_info *ii;
 141
 142         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 143         if (!ii)
 144                 return NULL;
 145         ii->i_bh = NULL;
 146         ii->i_state = 0;
 147         ii->vfs_inode.i_version = 1;
 148         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
 149         return &ii->vfs_inode;
 150 }
 151
 152 struct inode *nilfs_alloc_inode(struct super_block *sb)
 153 {
 154         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
 155 }
 156
 157 void nilfs_destroy_inode(struct inode *inode)
 158 {
 159         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 160 }
 161
 162 static void init_once(void *obj)
 163 {
 164         struct nilfs_inode_info *ii = obj;
 165
 166         INIT_LIST_HEAD(&ii->i_dirty);
 167 #ifdef CONFIG_NILFS_XATTR
 168         init_rwsem(&ii->xattr_sem);
 169 #endif
 170         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
 171         ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
 172         inode_init_once(&ii->vfs_inode);
 173 }
 174
 175 static int nilfs_init_inode_cache(void)
 176 {
 177         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
 178                                                sizeof(struct nilfs_inode_info),
 179                                                0, SLAB_RECLAIM_ACCOUNT,
 180                                                init_once);
 181
 182         return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
 183 }
 184
 185 static inline void nilfs_destroy_inode_cache(void)
 186 {
 187         kmem_cache_destroy(nilfs_inode_cachep);
 188 }
 189
 190 static void nilfs_clear_inode(struct inode *inode)
 191 {
 192         struct nilfs_inode_info *ii = NILFS_I(inode);
 193
 194         /*
 195          * Free resources allocated in nilfs_read_inode(), here.
 196          */
 197         BUG_ON(!list_empty(&ii->i_dirty));
 198         brelse(ii->i_bh);
 199         ii->i_bh = NULL;
 200
 201         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 202                 nilfs_bmap_clear(ii->i_bmap);
 203
 204         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 205 }
 206
 207 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
 208 {
 209         struct the_nilfs *nilfs = sbi->s_nilfs;
 210         int err;
 211         int barrier_done = 0;
 212
 213         if (nilfs_test_opt(sbi, BARRIER)) {
 214                 set_buffer_ordered(nilfs->ns_sbh[0]);
 215                 barrier_done = 1;
 216         }
 217  retry:
 218         set_buffer_dirty(nilfs->ns_sbh[0]);
 219         err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 220         if (err == -EOPNOTSUPP && barrier_done) {
 221                 nilfs_warning(sbi->s_super, __func__,
 222                               "barrier-based sync failed. "
 223                               "disabling barriers\n");
 224                 nilfs_clear_opt(sbi, BARRIER);
 225                 barrier_done = 0;
 226                 clear_buffer_ordered(nilfs->ns_sbh[0]);
 227                 goto retry;
 228         }
 229         if (unlikely(err)) {
 230                 printk(KERN_ERR
 231                        "NILFS: unable to write superblock (err=%d)\n", err);
 232                 if (err == -EIO && nilfs->ns_sbh[1]) {
 233                         nilfs_fall_back_super_block(nilfs);
 234                         goto retry;
 235                 }
 236         } else {
 237                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 238
 239                 /*
 240                  * The latest segment becomes trailable from the position
 241                  * written in superblock.
 242                  */
 243                 clear_nilfs_discontinued(nilfs);
 244
 245                 /* update GC protection for recent segments */
 246                 if (nilfs->ns_sbh[1]) {
 247                         sbp = NULL;
 248                         if (dupsb) {
 249                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 250                                 if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
 251                                         sbp = nilfs->ns_sbp[1];
 252                         }
 253                 }
 254                 if (sbp) {
 255                         spin_lock(&nilfs->ns_last_segment_lock);
 256                         nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 257                         spin_unlock(&nilfs->ns_last_segment_lock);
 258                 }
 259         }
 260
 261         return err;
 262 }
 263
 264 int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
 265 {
 266         struct the_nilfs *nilfs = sbi->s_nilfs;
 267         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 268         sector_t nfreeblocks;
 269         time_t t;
 270         int err;
 271
 272         /* nilfs->sem must be locked by the caller. */
 273         if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
 274                 if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
 275                         nilfs_swap_super_block(nilfs);
 276                 else {
 277                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 278                                sbi->s_super->s_id);
 279                         return -EIO;
 280                 }
 281         }
 282         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 283         if (unlikely(err)) {
 284                 printk(KERN_ERR "NILFS: failed to count free blocks\n");
 285                 return err;
 286         }
 287         spin_lock(&nilfs->ns_last_segment_lock);
 288         sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 289         sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 290         sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 291         spin_unlock(&nilfs->ns_last_segment_lock);
 292
 293         t = get_seconds();
 294         nilfs->ns_sbwtime[0] = t;
 295         sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 296         sbp[0]->s_wtime = cpu_to_le64(t);
 297         sbp[0]->s_sum = 0;
 298         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 299                                              (unsigned char *)sbp[0],
 300                                              nilfs->ns_sbsize));
 301         if (dupsb && sbp[1]) {
 302                 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 303                 nilfs->ns_sbwtime[1] = t;
 304         }
 305         sbi->s_super->s_dirt = 0;
 306         return nilfs_sync_super(sbi, dupsb);
 307 }
 308
 309 static void nilfs_put_super(struct super_block *sb)
 310 {
 311         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 312         struct the_nilfs *nilfs = sbi->s_nilfs;
 313
 314         lock_kernel();
 315
 316         nilfs_detach_segment_constructor(sbi);
 317
 318         if (!(sb->s_flags & MS_RDONLY)) {
 319                 down_write(&nilfs->ns_sem);
 320                 nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
 321                 nilfs_commit_super(sbi, 1);
 322                 up_write(&nilfs->ns_sem);
 323         }
 324         down_write(&nilfs->ns_super_sem);
 325         if (nilfs->ns_current == sbi)
 326                 nilfs->ns_current = NULL;
 327         up_write(&nilfs->ns_super_sem);
 328
 329         nilfs_detach_checkpoint(sbi);
 330         put_nilfs(sbi->s_nilfs);
 331         sbi->s_super = NULL;
 332         sb->s_fs_info = NULL;
 333         nilfs_put_sbinfo(sbi);
 334
 335         unlock_kernel();
 336 }
 337
 338 /**
 339  * nilfs_write_super - write super block(s) of NILFS
 340  * @sb: super_block
 341  *
 342  * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
 343  * clears s_dirt.  This function is called in the section protected by
 344  * lock_super().
 345  *
 346  * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
 347  * of the struct the_nilfs.  Lock order must be as follows:
 348  *
 349  *   1. lock_super()
 350  *   2.    down_write(&nilfs->ns_sem)
 351  *
 352  * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
 353  * of the super block (nilfs->ns_sbp[]).
 354  *
 355  * In most cases, VFS functions call lock_super() before calling these
 356  * methods.  So we must be careful not to bring on deadlocks when using
 357  * lock_super();  see generic_shutdown_super(), write_super(), and so on.
 358  *
 359  * Note that order of lock_kernel() and lock_super() depends on contexts
 360  * of VFS.  We should also note that lock_kernel() can be used in its
 361  * protective section and only the outermost one has an effect.
 362  */
 363 static void nilfs_write_super(struct super_block *sb)
 364 {
 365         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 366         struct the_nilfs *nilfs = sbi->s_nilfs;
 367
 368         down_write(&nilfs->ns_sem);
 369         if (!(sb->s_flags & MS_RDONLY)) {
 370                 struct nilfs_super_block **sbp = nilfs->ns_sbp;
 371                 u64 t = get_seconds();
 372                 int dupsb;
 373
 374                 if (!nilfs_discontinued(nilfs) && t >= nilfs->ns_sbwtime[0] &&
 375                     t < nilfs->ns_sbwtime[0] + NILFS_SB_FREQ) {
 376                         up_write(&nilfs->ns_sem);
 377                         return;
 378                 }
 379                 dupsb = sbp[1] && t > nilfs->ns_sbwtime[1] + NILFS_ALTSB_FREQ;
 380                 nilfs_commit_super(sbi, dupsb);
 381         }
 382         sb->s_dirt = 0;
 383         up_write(&nilfs->ns_sem);
 384 }
 385
 386 static int nilfs_sync_fs(struct super_block *sb, int wait)
 387 {
 388         int err = 0;
 389
 390         nilfs_write_super(sb);
 391
 392         /* This function is called when super block should be written back */
 393         if (wait)
 394                 err = nilfs_construct_segment(sb);
 395         return err;
 396 }
 397
 398 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
 399 {
 400         struct the_nilfs *nilfs = sbi->s_nilfs;
 401         struct nilfs_checkpoint *raw_cp;
 402         struct buffer_head *bh_cp;
 403         int err;
 404
 405         down_write(&nilfs->ns_super_sem);
 406         list_add(&sbi->s_list, &nilfs->ns_supers);
 407         up_write(&nilfs->ns_super_sem);
 408
 409         sbi->s_ifile = nilfs_mdt_new(
 410                 nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP);
 411         if (!sbi->s_ifile)
 412                 return -ENOMEM;
 413
 414         err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size);
 415         if (unlikely(err))
 416                 goto failed;
 417
 418         down_read(&nilfs->ns_segctor_sem);
 419         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 420                                           &bh_cp);
 421         up_read(&nilfs->ns_segctor_sem);
 422         if (unlikely(err)) {
 423                 if (err == -ENOENT || err == -EINVAL) {
 424                         printk(KERN_ERR
 425                                "NILFS: Invalid checkpoint "
 426                                "(checkpoint number=%llu)\n",
 427                                (unsigned long long)cno);
 428                         err = -EINVAL;
 429                 }
 430                 goto failed;
 431         }
 432         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
 433         if (unlikely(err))
 434                 goto failed_bh;
 435         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 436         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 437
 438         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 439         return 0;
 440
 441  failed_bh:
 442         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 443  failed:
 444         nilfs_mdt_destroy(sbi->s_ifile);
 445         sbi->s_ifile = NULL;
 446
 447         down_write(&nilfs->ns_super_sem);
 448         list_del_init(&sbi->s_list);
 449         up_write(&nilfs->ns_super_sem);
 450
 451         return err;
 452 }
 453
 454 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
 455 {
 456         struct the_nilfs *nilfs = sbi->s_nilfs;
 457
 458         nilfs_mdt_clear(sbi->s_ifile);
 459         nilfs_mdt_destroy(sbi->s_ifile);
 460         sbi->s_ifile = NULL;
 461         down_write(&nilfs->ns_super_sem);
 462         list_del_init(&sbi->s_list);
 463         up_write(&nilfs->ns_super_sem);
 464 }
 465
 466 static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
 467 {
 468         struct the_nilfs *nilfs = sbi->s_nilfs;
 469         int err = 0;
 470
 471         down_write(&nilfs->ns_sem);
 472         if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
 473                 nilfs->ns_mount_state |= NILFS_VALID_FS;
 474                 err = nilfs_commit_super(sbi, 1);
 475                 if (likely(!err))
 476                         printk(KERN_INFO "NILFS: recovery complete.\n");
 477         }
 478         up_write(&nilfs->ns_sem);
 479         return err;
 480 }
 481
 482 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 483 {
 484         struct super_block *sb = dentry->d_sb;
 485         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 486         struct the_nilfs *nilfs = sbi->s_nilfs;
 487         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 488         unsigned long long blocks;
 489         unsigned long overhead;
 490         unsigned long nrsvblocks;
 491         sector_t nfreeblocks;
 492         int err;
 493
 494         /*
 495          * Compute all of the segment blocks
 496          *
 497          * The blocks before first segment and after last segment
 498          * are excluded.
 499          */
 500         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 501                 - nilfs->ns_first_data_block;
 502         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 503
 504         /*
 505          * Compute the overhead
 506          *
 507          * When distributing meta data blocks outside semgent structure,
 508          * We must count them as the overhead.
 509          */
 510         overhead = 0;
 511
 512         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 513         if (unlikely(err))
 514                 return err;
 515
 516         buf->f_type = NILFS_SUPER_MAGIC;
 517         buf->f_bsize = sb->s_blocksize;
 518         buf->f_blocks = blocks - overhead;
 519         buf->f_bfree = nfreeblocks;
 520         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 521                 (buf->f_bfree - nrsvblocks) : 0;
 522         buf->f_files = atomic_read(&sbi->s_inodes_count);
 523         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 524         buf->f_namelen = NILFS_NAME_LEN;
 525         buf->f_fsid.val[0] = (u32)id;
 526         buf->f_fsid.val[1] = (u32)(id >> 32);
 527
 528         return 0;
 529 }
 530
 531 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 532 {
 533         struct super_block *sb = vfs->mnt_sb;
 534         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 535
 536         if (!nilfs_test_opt(sbi, BARRIER))
 537                 seq_printf(seq, ",barrier=off");
 538         if (nilfs_test_opt(sbi, SNAPSHOT))
 539                 seq_printf(seq, ",cp=%llu",
 540                            (unsigned long long int)sbi->s_snapshot_cno);
 541         if (nilfs_test_opt(sbi, ERRORS_RO))
 542                 seq_printf(seq, ",errors=remount-ro");
 543         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 544                 seq_printf(seq, ",errors=panic");
 545         if (nilfs_test_opt(sbi, STRICT_ORDER))
 546                 seq_printf(seq, ",order=strict");
 547
 548         return 0;
 549 }
 550
 551 static struct super_operations nilfs_sops = {
 552         .alloc_inode    = nilfs_alloc_inode,
 553         .destroy_inode  = nilfs_destroy_inode,
 554         .dirty_inode    = nilfs_dirty_inode,
 555         /* .write_inode    = nilfs_write_inode, */
 556         /* .put_inode      = nilfs_put_inode, */
 557         /* .drop_inode    = nilfs_drop_inode, */
 558         .delete_inode   = nilfs_delete_inode,
 559         .put_super      = nilfs_put_super,
 560         .write_super    = nilfs_write_super,
 561         .sync_fs        = nilfs_sync_fs,
 562         /* .write_super_lockfs */
 563         /* .unlockfs */
 564         .statfs         = nilfs_statfs,
 565         .remount_fs     = nilfs_remount,
 566         .clear_inode    = nilfs_clear_inode,
 567         /* .umount_begin */
 568         .show_options = nilfs_show_options
 569 };
 570
 571 static struct inode *
 572 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 573 {
 574         struct inode *inode;
 575
 576         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
 577             ino != NILFS_SKETCH_INO)
 578                 return ERR_PTR(-ESTALE);
 579
 580         inode = nilfs_iget(sb, ino);
 581         if (IS_ERR(inode))
 582                 return ERR_CAST(inode);
 583         if (generation && inode->i_generation != generation) {
 584                 iput(inode);
 585                 return ERR_PTR(-ESTALE);
 586         }
 587
 588         return inode;
 589 }
 590
 591 static struct dentry *
 592 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
 593                    int fh_type)
 594 {
 595         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 596                                     nilfs_nfs_get_inode);
 597 }
 598
 599 static struct dentry *
 600 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
 601                    int fh_type)
 602 {
 603         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 604                                     nilfs_nfs_get_inode);
 605 }
 606
 607 static struct export_operations nilfs_export_ops = {
 608         .fh_to_dentry = nilfs_fh_to_dentry,
 609         .fh_to_parent = nilfs_fh_to_parent,
 610         .get_parent = nilfs_get_parent,
 611 };
 612
 613 enum {
 614         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 615         Opt_barrier, Opt_snapshot, Opt_order,
 616         Opt_err,
 617 };
 618
 619 static match_table_t tokens = {
 620         {Opt_err_cont, "errors=continue"},
 621         {Opt_err_panic, "errors=panic"},
 622         {Opt_err_ro, "errors=remount-ro"},
 623         {Opt_barrier, "barrier=%s"},
 624         {Opt_snapshot, "cp=%u"},
 625         {Opt_order, "order=%s"},
 626         {Opt_err, NULL}
 627 };
 628
 629 static int match_bool(substring_t *s, int *result)
 630 {
 631         int len = s->to - s->from;
 632
 633         if (strncmp(s->from, "on", len) == 0)
 634                 *result = 1;
 635         else if (strncmp(s->from, "off", len) == 0)
 636                 *result = 0;
 637         else
 638                 return 1;
 639         return 0;
 640 }
 641
 642 static int parse_options(char *options, struct super_block *sb)
 643 {
 644         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 645         char *p;
 646         substring_t args[MAX_OPT_ARGS];
 647         int option;
 648
 649         if (!options)
 650                 return 1;
 651
 652         while ((p = strsep(&options, ",")) != NULL) {
 653                 int token;
 654                 if (!*p)
 655                         continue;
 656
 657                 token = match_token(p, tokens, args);
 658                 switch (token) {
 659                 case Opt_barrier:
 660                         if (match_bool(&args[0], &option))
 661                                 return 0;
 662                         if (option)
 663                                 nilfs_set_opt(sbi, BARRIER);
 664                         else
 665                                 nilfs_clear_opt(sbi, BARRIER);
 666                         break;
 667                 case Opt_order:
 668                         if (strcmp(args[0].from, "relaxed") == 0)
 669                                 /* Ordered data semantics */
 670                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 671                         else if (strcmp(args[0].from, "strict") == 0)
 672                                 /* Strict in-order semantics */
 673                                 nilfs_set_opt(sbi, STRICT_ORDER);
 674                         else
 675                                 return 0;
 676                         break;
 677                 case Opt_err_panic:
 678                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 679                         break;
 680                 case Opt_err_ro:
 681                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 682                         break;
 683                 case Opt_err_cont:
 684                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 685                         break;
 686                 case Opt_snapshot:
 687                         if (match_int(&args[0], &option) || option <= 0)
 688                                 return 0;
 689                         if (!(sb->s_flags & MS_RDONLY))
 690                                 return 0;
 691                         sbi->s_snapshot_cno = option;
 692                         nilfs_set_opt(sbi, SNAPSHOT);
 693                         break;
 694                 default:
 695                         printk(KERN_ERR
 696                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 697                         return 0;
 698                 }
 699         }
 700         return 1;
 701 }
 702
 703 static inline void
 704 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 705                           struct nilfs_super_block *sbp)
 706 {
 707         sbi->s_mount_opt =
 708                 NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
 709 }
 710
 711 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 712 {
 713         struct the_nilfs *nilfs = sbi->s_nilfs;
 714         struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 715         int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
 716         int mnt_count = le16_to_cpu(sbp->s_mnt_count);
 717
 718         /* nilfs->sem must be locked by the caller. */
 719         if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
 720                 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
 721         } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 722                 printk(KERN_WARNING
 723                        "NILFS warning: mounting fs with errors\n");
 724 #if 0
 725         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 726                 printk(KERN_WARNING
 727                        "NILFS warning: maximal mount count reached\n");
 728 #endif
 729         }
 730         if (!max_mnt_count)
 731                 sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 732
 733         sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
 734         sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
 735         sbp->s_mtime = cpu_to_le64(get_seconds());
 736         return nilfs_commit_super(sbi, 1);
 737 }
 738
 739 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 740                                                  u64 pos, int blocksize,
 741                                                  struct buffer_head **pbh)
 742 {
 743         unsigned long long sb_index = pos;
 744         unsigned long offset;
 745
 746         offset = do_div(sb_index, blocksize);
 747         *pbh = sb_bread(sb, sb_index);
 748         if (!*pbh)
 749                 return NULL;
 750         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 751 }
 752
 753 int nilfs_store_magic_and_option(struct super_block *sb,
 754                                  struct nilfs_super_block *sbp,
 755                                  char *data)
 756 {
 757         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 758
 759         sb->s_magic = le16_to_cpu(sbp->s_magic);
 760
 761         /* FS independent flags */
 762 #ifdef NILFS_ATIME_DISABLE
 763         sb->s_flags |= MS_NOATIME;
 764 #endif
 765
 766         nilfs_set_default_options(sbi, sbp);
 767
 768         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 769         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 770         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 771         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 772
 773         return !parse_options(data, sb) ? -EINVAL : 0 ;
 774 }
 775
 776 /**
 777  * nilfs_fill_super() - initialize a super block instance
 778  * @sb: super_block
 779  * @data: mount options
 780  * @silent: silent mode flag
 781  * @nilfs: the_nilfs struct
 782  *
 783  * This function is called exclusively by nilfs->ns_mount_mutex.
 784  * So, the recovery process is protected from other simultaneous mounts.
 785  */
 786 static int
 787 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 788                  struct the_nilfs *nilfs)
 789 {
 790         struct nilfs_sb_info *sbi;
 791         struct inode *root;
 792         __u64 cno;
 793         int err;
 794
 795         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 796         if (!sbi)
 797                 return -ENOMEM;
 798
 799         sb->s_fs_info = sbi;
 800
 801         get_nilfs(nilfs);
 802         sbi->s_nilfs = nilfs;
 803         sbi->s_super = sb;
 804         atomic_set(&sbi->s_count, 1);
 805
 806         err = init_nilfs(nilfs, sbi, (char *)data);
 807         if (err)
 808                 goto failed_sbi;
 809
 810         spin_lock_init(&sbi->s_inode_lock);
 811         INIT_LIST_HEAD(&sbi->s_dirty_files);
 812         INIT_LIST_HEAD(&sbi->s_list);
 813
 814         /*
 815          * Following initialization is overlapped because
 816          * nilfs_sb_info structure has been cleared at the beginning.
 817          * But we reserve them to keep our interest and make ready
 818          * for the future change.
 819          */
 820         get_random_bytes(&sbi->s_next_generation,
 821                          sizeof(sbi->s_next_generation));
 822         spin_lock_init(&sbi->s_next_gen_lock);
 823
 824         sb->s_op = &nilfs_sops;
 825         sb->s_export_op = &nilfs_export_ops;
 826         sb->s_root = NULL;
 827         sb->s_time_gran = 1;
 828
 829         if (!nilfs_loaded(nilfs)) {
 830                 err = load_nilfs(nilfs, sbi);
 831                 if (err)
 832                         goto failed_sbi;
 833         }
 834         cno = nilfs_last_cno(nilfs);
 835
 836         if (sb->s_flags & MS_RDONLY) {
 837                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 838                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
 839                                                        sbi->s_snapshot_cno);
 840                         if (err < 0)
 841                                 goto failed_sbi;
 842                         if (!err) {
 843                                 printk(KERN_ERR
 844                                        "NILFS: The specified checkpoint is "
 845                                        "not a snapshot "
 846                                        "(checkpoint number=%llu).\n",
 847                                        (unsigned long long)sbi->s_snapshot_cno);
 848                                 err = -EINVAL;
 849                                 goto failed_sbi;
 850                         }
 851                         cno = sbi->s_snapshot_cno;
 852                 } else
 853                         /* Read-only mount */
 854                         sbi->s_snapshot_cno = cno;
 855         }
 856
 857         err = nilfs_attach_checkpoint(sbi, cno);
 858         if (err) {
 859                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 860                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 861                 goto failed_sbi;
 862         }
 863
 864         if (!(sb->s_flags & MS_RDONLY)) {
 865                 err = nilfs_attach_segment_constructor(sbi);
 866                 if (err)
 867                         goto failed_checkpoint;
 868         }
 869
 870         root = nilfs_iget(sb, NILFS_ROOT_INO);
 871         if (IS_ERR(root)) {
 872                 printk(KERN_ERR "NILFS: get root inode failed\n");
 873                 err = PTR_ERR(root);
 874                 goto failed_segctor;
 875         }
 876         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 877                 iput(root);
 878                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 879                 err = -EINVAL;
 880                 goto failed_segctor;
 881         }
 882         sb->s_root = d_alloc_root(root);
 883         if (!sb->s_root) {
 884                 iput(root);
 885                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 886                 err = -ENOMEM;
 887                 goto failed_segctor;
 888         }
 889
 890         if (!(sb->s_flags & MS_RDONLY)) {
 891                 down_write(&nilfs->ns_sem);
 892                 nilfs_setup_super(sbi);
 893                 up_write(&nilfs->ns_sem);
 894         }
 895
 896         err = nilfs_mark_recovery_complete(sbi);
 897         if (unlikely(err)) {
 898                 printk(KERN_ERR "NILFS: recovery failed.\n");
 899                 goto failed_root;
 900         }
 901
 902         down_write(&nilfs->ns_super_sem);
 903         if (!nilfs_test_opt(sbi, SNAPSHOT))
 904                 nilfs->ns_current = sbi;
 905         up_write(&nilfs->ns_super_sem);
 906
 907         return 0;
 908
 909  failed_root:
 910         dput(sb->s_root);
 911         sb->s_root = NULL;
 912
 913  failed_segctor:
 914         nilfs_detach_segment_constructor(sbi);
 915
 916  failed_checkpoint:
 917         nilfs_detach_checkpoint(sbi);
 918
 919  failed_sbi:
 920         put_nilfs(nilfs);
 921         sb->s_fs_info = NULL;
 922         nilfs_put_sbinfo(sbi);
 923         return err;
 924 }
 925
 926 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 927 {
 928         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 929         struct nilfs_super_block *sbp;
 930         struct the_nilfs *nilfs = sbi->s_nilfs;
 931         unsigned long old_sb_flags;
 932         struct nilfs_mount_options old_opts;
 933         int err;
 934
 935         lock_kernel();
 936
 937         down_write(&nilfs->ns_super_sem);
 938         old_sb_flags = sb->s_flags;
 939         old_opts.mount_opt = sbi->s_mount_opt;
 940         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 941
 942         if (!parse_options(data, sb)) {
 943                 err = -EINVAL;
 944                 goto restore_opts;
 945         }
 946         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 947
 948         if ((*flags & MS_RDONLY) &&
 949             sbi->s_snapshot_cno != old_opts.snapshot_cno) {
 950                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 951                        "remount to a different snapshot. \n",
 952                        sb->s_id);
 953                 err = -EINVAL;
 954                 goto restore_opts;
 955         }
 956
 957         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 958                 goto out;
 959         if (*flags & MS_RDONLY) {
 960                 /* Shutting down the segment constructor */
 961                 nilfs_detach_segment_constructor(sbi);
 962                 sb->s_flags |= MS_RDONLY;
 963
 964                 sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
 965                 /* nilfs_set_opt(sbi, SNAPSHOT); */
 966
 967                 /*
 968                  * Remounting a valid RW partition RDONLY, so set
 969                  * the RDONLY flag and then mark the partition as valid again.
 970                  */
 971                 down_write(&nilfs->ns_sem);
 972                 sbp = nilfs->ns_sbp[0];
 973                 if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
 974                     (nilfs->ns_mount_state & NILFS_VALID_FS))
 975                         sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
 976                 sbp->s_mtime = cpu_to_le64(get_seconds());
 977                 nilfs_commit_super(sbi, 1);
 978                 up_write(&nilfs->ns_sem);
 979         } else {
 980                 /*
 981                  * Mounting a RDONLY partition read-write, so reread and
 982                  * store the current valid flag.  (It may have been changed
 983                  * by fsck since we originally mounted the partition.)
 984                  */
 985                 if (nilfs->ns_current && nilfs->ns_current != sbi) {
 986                         printk(KERN_WARNING "NILFS (device %s): couldn't "
 987                                "remount because an RW-mount exists.\n",
 988                                sb->s_id);
 989                         err = -EBUSY;
 990                         goto restore_opts;
 991                 }
 992                 if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
 993                         printk(KERN_WARNING "NILFS (device %s): couldn't "
 994                                "remount because the current RO-mount is not "
 995                                "the latest one.\n",
 996                                sb->s_id);
 997                         err = -EINVAL;
 998                         goto restore_opts;
 999                 }
1000                 sb->s_flags &= ~MS_RDONLY;
1001                 nilfs_clear_opt(sbi, SNAPSHOT);
1002                 sbi->s_snapshot_cno = 0;
1003
1004                 err = nilfs_attach_segment_constructor(sbi);
1005                 if (err)
1006                         goto restore_opts;
1007
1008                 down_write(&nilfs->ns_sem);
1009                 nilfs_setup_super(sbi);
1010                 up_write(&nilfs->ns_sem);
1011
1012                 nilfs->ns_current = sbi;
1013         }
1014  out:
1015         up_write(&nilfs->ns_super_sem);
1016         unlock_kernel();
1017         return 0;
1018
1019  restore_opts:
1020         sb->s_flags = old_sb_flags;
1021         sbi->s_mount_opt = old_opts.mount_opt;
1022         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1023         up_write(&nilfs->ns_super_sem);
1024         unlock_kernel();
1025         return err;
1026 }
1027
1028 struct nilfs_super_data {
1029         struct block_device *bdev;
1030         struct nilfs_sb_info *sbi;
1031         __u64 cno;
1032         int flags;
1033 };
1034
1035 /**
1036  * nilfs_identify - pre-read mount options needed to identify mount instance
1037  * @data: mount options
1038  * @sd: nilfs_super_data
1039  */
1040 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1041 {
1042         char *p, *options = data;
1043         substring_t args[MAX_OPT_ARGS];
1044         int option, token;
1045         int ret = 0;
1046
1047         do {
1048                 p = strsep(&options, ",");
1049                 if (p != NULL && *p) {
1050                         token = match_token(p, tokens, args);
1051                         if (token == Opt_snapshot) {
1052                                 if (!(sd->flags & MS_RDONLY))
1053                                         ret++;
1054                                 else {
1055                                         ret = match_int(&args[0], &option);
1056                                         if (!ret) {
1057                                                 if (option > 0)
1058                                                         sd->cno = option;
1059                                                 else
1060                                                         ret++;
1061                                         }
1062                                 }
1063                         }
1064                         if (ret)
1065                                 printk(KERN_ERR
1066                                        "NILFS: invalid mount option: %s\n", p);
1067                 }
1068                 if (!options)
1069                         break;
1070                 BUG_ON(options == data);
1071                 *(options - 1) = ',';
1072         } while (!ret);
1073         return ret;
1074 }
1075
1076 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1077 {
1078         struct nilfs_super_data *sd = data;
1079
1080         s->s_bdev = sd->bdev;
1081         s->s_dev = s->s_bdev->bd_dev;
1082         return 0;
1083 }
1084
1085 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1086 {
1087         struct nilfs_super_data *sd = data;
1088
1089         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1090 }
1091
1092 static int
1093 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1094              const char *dev_name, void *data, struct vfsmount *mnt)
1095 {
1096         struct nilfs_super_data sd;
1097         struct super_block *s;
1098         struct the_nilfs *nilfs;
1099         int err, need_to_close = 1;
1100
1101         sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
1102         if (IS_ERR(sd.bdev))
1103                 return PTR_ERR(sd.bdev);
1104
1105         /*
1106          * To get mount instance using sget() vfs-routine, NILFS needs
1107          * much more information than normal filesystems to identify mount
1108          * instance.  For snapshot mounts, not only a mount type (ro-mount
1109          * or rw-mount) but also a checkpoint number is required.
1110          */
1111         sd.cno = 0;
1112         sd.flags = flags;
1113         if (nilfs_identify((char *)data, &sd)) {
1114                 err = -EINVAL;
1115                 goto failed;
1116         }
1117
1118         nilfs = find_or_create_nilfs(sd.bdev);
1119         if (!nilfs) {
1120                 err = -ENOMEM;
1121                 goto failed;
1122         }
1123
1124         mutex_lock(&nilfs->ns_mount_mutex);
1125
1126         if (!sd.cno) {
1127                 /*
1128                  * Check if an exclusive mount exists or not.
1129                  * Snapshot mounts coexist with a current mount
1130                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1131                  * ro-mount are mutually exclusive.
1132                  */
1133                 down_read(&nilfs->ns_super_sem);
1134                 if (nilfs->ns_current &&
1135                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1136                      & MS_RDONLY)) {
1137                         up_read(&nilfs->ns_super_sem);
1138                         err = -EBUSY;
1139                         goto failed_unlock;
1140                 }
1141                 up_read(&nilfs->ns_super_sem);
1142         }
1143
1144         /*
1145          * Find existing nilfs_sb_info struct
1146          */
1147         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1148
1149         if (!sd.cno)
1150                 /* trying to get the latest checkpoint.  */
1151                 sd.cno = nilfs_last_cno(nilfs);
1152
1153         /*
1154          * Get super block instance holding the nilfs_sb_info struct.
1155          * A new instance is allocated if no existing mount is present or
1156          * existing instance has been unmounted.
1157          */
1158         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1159         if (sd.sbi)
1160                 nilfs_put_sbinfo(sd.sbi);
1161
1162         if (IS_ERR(s)) {
1163                 err = PTR_ERR(s);
1164                 goto failed_unlock;
1165         }
1166
1167         if (!s->s_root) {
1168                 char b[BDEVNAME_SIZE];
1169
1170                 /* New superblock instance created */
1171                 s->s_flags = flags;
1172                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1173                 sb_set_blocksize(s, block_size(sd.bdev));
1174
1175                 err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
1176                 if (err)
1177                         goto cancel_new;
1178
1179                 s->s_flags |= MS_ACTIVE;
1180                 need_to_close = 0;
1181         }
1182
1183         mutex_unlock(&nilfs->ns_mount_mutex);
1184         put_nilfs(nilfs);
1185         if (need_to_close)
1186                 close_bdev_exclusive(sd.bdev, flags);
1187         simple_set_mnt(mnt, s);
1188         return 0;
1189
1190  failed_unlock:
1191         mutex_unlock(&nilfs->ns_mount_mutex);
1192         put_nilfs(nilfs);
1193  failed:
1194         close_bdev_exclusive(sd.bdev, flags);
1195
1196         return err;
1197
1198  cancel_new:
1199         /* Abandoning the newly allocated superblock */
1200         mutex_unlock(&nilfs->ns_mount_mutex);
1201         put_nilfs(nilfs);
1202         up_write(&s->s_umount);
1203         deactivate_super(s);
1204         /*
1205          * deactivate_super() invokes close_bdev_exclusive().
1206          * We must finish all post-cleaning before this call;
1207          * put_nilfs() needs the block device.
1208          */
1209         return err;
1210 }
1211
1212 struct file_system_type nilfs_fs_type = {
1213         .owner    = THIS_MODULE,
1214         .name     = "nilfs2",
1215         .get_sb   = nilfs_get_sb,
1216         .kill_sb  = kill_block_super,
1217         .fs_flags = FS_REQUIRES_DEV,
1218 };
1219
1220 static int __init init_nilfs_fs(void)
1221 {
1222         int err;
1223
1224         err = nilfs_init_inode_cache();
1225         if (err)
1226                 goto failed;
1227
1228         err = nilfs_init_transaction_cache();
1229         if (err)
1230                 goto failed_inode_cache;
1231
1232         err = nilfs_init_segbuf_cache();
1233         if (err)
1234                 goto failed_transaction_cache;
1235
1236         err = nilfs_btree_path_cache_init();
1237         if (err)
1238                 goto failed_segbuf_cache;
1239
1240         err = register_filesystem(&nilfs_fs_type);
1241         if (err)
1242                 goto failed_btree_path_cache;
1243
1244         return 0;
1245
1246  failed_btree_path_cache:
1247         nilfs_btree_path_cache_destroy();
1248
1249  failed_segbuf_cache:
1250         nilfs_destroy_segbuf_cache();
1251
1252  failed_transaction_cache:
1253         nilfs_destroy_transaction_cache();
1254
1255  failed_inode_cache:
1256         nilfs_destroy_inode_cache();
1257
1258  failed:
1259         return err;
1260 }
1261
1262 static void __exit exit_nilfs_fs(void)
1263 {
1264         nilfs_destroy_segbuf_cache();
1265         nilfs_destroy_transaction_cache();
1266         nilfs_destroy_inode_cache();
1267         nilfs_btree_path_cache_destroy();
1268         unregister_filesystem(&nilfs_fs_type);
1269 }
1270
1271 module_init(init_nilfs_fs)
1272 module_exit(exit_nilfs_fs)