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/vfs.h>
  49 #include <linux/writeback.h>
  50 #include <linux/kobject.h>
  51 #include <linux/seq_file.h>
  52 #include <linux/mount.h>
  53 #include "nilfs.h"
  54 #include "export.h"
  55 #include "mdt.h"
  56 #include "alloc.h"
  57 #include "btree.h"
  58 #include "btnode.h"
  59 #include "page.h"
  60 #include "cpfile.h"
  61 #include "ifile.h"
  62 #include "dat.h"
  63 #include "segment.h"
  64 #include "segbuf.h"
  65
  66 MODULE_AUTHOR("NTT Corp.");
  67 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  68                    "(NILFS)");
  69 MODULE_LICENSE("GPL");
  70
  71 struct kmem_cache *nilfs_inode_cachep;
  72 struct kmem_cache *nilfs_transaction_cachep;
  73 struct kmem_cache *nilfs_segbuf_cachep;
  74 struct kmem_cache *nilfs_btree_path_cache;
  75
  76 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  77
  78 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  79 {
  80         struct the_nilfs *nilfs = sbi->s_nilfs;
  81         struct nilfs_super_block **sbp;
  82
  83         down_write(&nilfs->ns_sem);
  84         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  85                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  86                 sbp = nilfs_prepare_super(sbi, 0);
  87                 if (likely(sbp)) {
  88                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  89                         if (sbp[1])
  90                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  91                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  92                 }
  93         }
  94         up_write(&nilfs->ns_sem);
  95 }
  96
  97 /**
  98  * nilfs_error() - report failure condition on a filesystem
  99  *
 100  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 101  * reporting an error message.  It should be called when NILFS detects
 102  * incoherences or defects of meta data on disk.  As for sustainable
 103  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 104  * function should be used instead.
 105  *
 106  * The segment constructor must not call this function because it can
 107  * kill itself.
 108  */
 109 void nilfs_error(struct super_block *sb, const char *function,
 110                  const char *fmt, ...)
 111 {
 112         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 113         va_list args;
 114
 115         va_start(args, fmt);
 116         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 117         vprintk(fmt, args);
 118         printk("\n");
 119         va_end(args);
 120
 121         if (!(sb->s_flags & MS_RDONLY)) {
 122                 nilfs_set_error(sbi);
 123
 124                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 125                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 126                         sb->s_flags |= MS_RDONLY;
 127                 }
 128         }
 129
 130         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 131                 panic("NILFS (device %s): panic forced after error\n",
 132                       sb->s_id);
 133 }
 134
 135 void nilfs_warning(struct super_block *sb, const char *function,
 136                    const char *fmt, ...)
 137 {
 138         va_list args;
 139
 140         va_start(args, fmt);
 141         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 142                sb->s_id, function);
 143         vprintk(fmt, args);
 144         printk("\n");
 145         va_end(args);
 146 }
 147
 148
 149 struct inode *nilfs_alloc_inode(struct super_block *sb)
 150 {
 151         struct nilfs_inode_info *ii;
 152
 153         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 154         if (!ii)
 155                 return NULL;
 156         ii->i_bh = NULL;
 157         ii->i_state = 0;
 158         ii->i_cno = 0;
 159         ii->vfs_inode.i_version = 1;
 160         nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
 161         return &ii->vfs_inode;
 162 }
 163
 164 void nilfs_destroy_inode(struct inode *inode)
 165 {
 166         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 167
 168         if (mdi) {
 169                 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 170                 kfree(mdi);
 171         }
 172         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 173 }
 174
 175 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 176 {
 177         struct the_nilfs *nilfs = sbi->s_nilfs;
 178         int err;
 179
 180  retry:
 181         set_buffer_dirty(nilfs->ns_sbh[0]);
 182
 183         if (nilfs_test_opt(sbi, BARRIER)) {
 184                 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 185                                           WRITE_SYNC | WRITE_BARRIER);
 186                 if (err == -EOPNOTSUPP) {
 187                         nilfs_warning(sbi->s_super, __func__,
 188                                       "barrier-based sync failed. "
 189                                       "disabling barriers\n");
 190                         nilfs_clear_opt(sbi, BARRIER);
 191                         goto retry;
 192                 }
 193         } else {
 194                 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 195         }
 196
 197         if (unlikely(err)) {
 198                 printk(KERN_ERR
 199                        "NILFS: unable to write superblock (err=%d)\n", err);
 200                 if (err == -EIO && nilfs->ns_sbh[1]) {
 201                         /*
 202                          * sbp[0] points to newer log than sbp[1],
 203                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 204                          */
 205                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 206                                nilfs->ns_sbsize);
 207                         nilfs_fall_back_super_block(nilfs);
 208                         goto retry;
 209                 }
 210         } else {
 211                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 212
 213                 nilfs->ns_sbwcount++;
 214
 215                 /*
 216                  * The latest segment becomes trailable from the position
 217                  * written in superblock.
 218                  */
 219                 clear_nilfs_discontinued(nilfs);
 220
 221                 /* update GC protection for recent segments */
 222                 if (nilfs->ns_sbh[1]) {
 223                         if (flag == NILFS_SB_COMMIT_ALL) {
 224                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 225                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 226                                         goto out;
 227                         }
 228                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 229                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 230                                 sbp = nilfs->ns_sbp[1];
 231                 }
 232
 233                 spin_lock(&nilfs->ns_last_segment_lock);
 234                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 235                 spin_unlock(&nilfs->ns_last_segment_lock);
 236         }
 237  out:
 238         return err;
 239 }
 240
 241 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 242                           struct the_nilfs *nilfs)
 243 {
 244         sector_t nfreeblocks;
 245
 246         /* nilfs->ns_sem must be locked by the caller. */
 247         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 248         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 249
 250         spin_lock(&nilfs->ns_last_segment_lock);
 251         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 252         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 253         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 254         spin_unlock(&nilfs->ns_last_segment_lock);
 255 }
 256
 257 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 258                                                int flip)
 259 {
 260         struct the_nilfs *nilfs = sbi->s_nilfs;
 261         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 262
 263         /* nilfs->ns_sem must be locked by the caller. */
 264         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 265                 if (sbp[1] &&
 266                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 267                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 268                 } else {
 269                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 270                                sbi->s_super->s_id);
 271                         return NULL;
 272                 }
 273         } else if (sbp[1] &&
 274                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 275                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 276         }
 277
 278         if (flip && sbp[1])
 279                 nilfs_swap_super_block(nilfs);
 280
 281         return sbp;
 282 }
 283
 284 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 285 {
 286         struct the_nilfs *nilfs = sbi->s_nilfs;
 287         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 288         time_t t;
 289
 290         /* nilfs->ns_sem must be locked by the caller. */
 291         t = get_seconds();
 292         nilfs->ns_sbwtime = t;
 293         sbp[0]->s_wtime = cpu_to_le64(t);
 294         sbp[0]->s_sum = 0;
 295         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 296                                              (unsigned char *)sbp[0],
 297                                              nilfs->ns_sbsize));
 298         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 299                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 300                 sbp[1]->s_sum = 0;
 301                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 302                                             (unsigned char *)sbp[1],
 303                                             nilfs->ns_sbsize));
 304         }
 305         clear_nilfs_sb_dirty(nilfs);
 306         return nilfs_sync_super(sbi, flag);
 307 }
 308
 309 /**
 310  * nilfs_cleanup_super() - write filesystem state for cleanup
 311  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 312  *
 313  * This function restores state flags in the on-disk super block.
 314  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 315  * filesystem was not clean previously.
 316  */
 317 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 318 {
 319         struct nilfs_super_block **sbp;
 320         int flag = NILFS_SB_COMMIT;
 321         int ret = -EIO;
 322
 323         sbp = nilfs_prepare_super(sbi, 0);
 324         if (sbp) {
 325                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 326                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 327                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 328                         /*
 329                          * make the "clean" flag also to the opposite
 330                          * super block if both super blocks point to
 331                          * the same checkpoint.
 332                          */
 333                         sbp[1]->s_state = sbp[0]->s_state;
 334                         flag = NILFS_SB_COMMIT_ALL;
 335                 }
 336                 ret = nilfs_commit_super(sbi, flag);
 337         }
 338         return ret;
 339 }
 340
 341 static void nilfs_put_super(struct super_block *sb)
 342 {
 343         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 344         struct the_nilfs *nilfs = sbi->s_nilfs;
 345
 346         nilfs_detach_segment_constructor(sbi);
 347
 348         if (!(sb->s_flags & MS_RDONLY)) {
 349                 down_write(&nilfs->ns_sem);
 350                 nilfs_cleanup_super(sbi);
 351                 up_write(&nilfs->ns_sem);
 352         }
 353
 354         iput(nilfs->ns_sufile);
 355         iput(nilfs->ns_cpfile);
 356         iput(nilfs->ns_dat);
 357
 358         destroy_nilfs(nilfs);
 359         sbi->s_super = NULL;
 360         sb->s_fs_info = NULL;
 361         kfree(sbi);
 362 }
 363
 364 static int nilfs_sync_fs(struct super_block *sb, int wait)
 365 {
 366         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 367         struct the_nilfs *nilfs = sbi->s_nilfs;
 368         struct nilfs_super_block **sbp;
 369         int err = 0;
 370
 371         /* This function is called when super block should be written back */
 372         if (wait)
 373                 err = nilfs_construct_segment(sb);
 374
 375         down_write(&nilfs->ns_sem);
 376         if (nilfs_sb_dirty(nilfs)) {
 377                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 378                 if (likely(sbp)) {
 379                         nilfs_set_log_cursor(sbp[0], nilfs);
 380                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 381                 }
 382         }
 383         up_write(&nilfs->ns_sem);
 384
 385         return err;
 386 }
 387
 388 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 389                             struct nilfs_root **rootp)
 390 {
 391         struct the_nilfs *nilfs = sbi->s_nilfs;
 392         struct nilfs_root *root;
 393         struct nilfs_checkpoint *raw_cp;
 394         struct buffer_head *bh_cp;
 395         int err = -ENOMEM;
 396
 397         root = nilfs_find_or_create_root(
 398                 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
 399         if (!root)
 400                 return err;
 401
 402         if (root->ifile)
 403                 goto reuse; /* already attached checkpoint */
 404
 405         down_read(&nilfs->ns_segctor_sem);
 406         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 407                                           &bh_cp);
 408         up_read(&nilfs->ns_segctor_sem);
 409         if (unlikely(err)) {
 410                 if (err == -ENOENT || err == -EINVAL) {
 411                         printk(KERN_ERR
 412                                "NILFS: Invalid checkpoint "
 413                                "(checkpoint number=%llu)\n",
 414                                (unsigned long long)cno);
 415                         err = -EINVAL;
 416                 }
 417                 goto failed;
 418         }
 419
 420         err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size,
 421                                &raw_cp->cp_ifile_inode, &root->ifile);
 422         if (err)
 423                 goto failed_bh;
 424
 425         atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 426         atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 427
 428         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 429
 430  reuse:
 431         *rootp = root;
 432         return 0;
 433
 434  failed_bh:
 435         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 436  failed:
 437         nilfs_put_root(root);
 438
 439         return err;
 440 }
 441
 442 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 443 {
 444         struct super_block *sb = dentry->d_sb;
 445         struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
 446         struct the_nilfs *nilfs = root->nilfs;
 447         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 448         unsigned long long blocks;
 449         unsigned long overhead;
 450         unsigned long nrsvblocks;
 451         sector_t nfreeblocks;
 452         int err;
 453
 454         /*
 455          * Compute all of the segment blocks
 456          *
 457          * The blocks before first segment and after last segment
 458          * are excluded.
 459          */
 460         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 461                 - nilfs->ns_first_data_block;
 462         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 463
 464         /*
 465          * Compute the overhead
 466          *
 467          * When distributing meta data blocks outside segment structure,
 468          * We must count them as the overhead.
 469          */
 470         overhead = 0;
 471
 472         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 473         if (unlikely(err))
 474                 return err;
 475
 476         buf->f_type = NILFS_SUPER_MAGIC;
 477         buf->f_bsize = sb->s_blocksize;
 478         buf->f_blocks = blocks - overhead;
 479         buf->f_bfree = nfreeblocks;
 480         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 481                 (buf->f_bfree - nrsvblocks) : 0;
 482         buf->f_files = atomic_read(&root->inodes_count);
 483         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 484         buf->f_namelen = NILFS_NAME_LEN;
 485         buf->f_fsid.val[0] = (u32)id;
 486         buf->f_fsid.val[1] = (u32)(id >> 32);
 487
 488         return 0;
 489 }
 490
 491 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 492 {
 493         struct super_block *sb = vfs->mnt_sb;
 494         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 495         struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
 496
 497         if (!nilfs_test_opt(sbi, BARRIER))
 498                 seq_puts(seq, ",nobarrier");
 499         if (root->cno != NILFS_CPTREE_CURRENT_CNO)
 500                 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
 501         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 502                 seq_puts(seq, ",errors=panic");
 503         if (nilfs_test_opt(sbi, ERRORS_CONT))
 504                 seq_puts(seq, ",errors=continue");
 505         if (nilfs_test_opt(sbi, STRICT_ORDER))
 506                 seq_puts(seq, ",order=strict");
 507         if (nilfs_test_opt(sbi, NORECOVERY))
 508                 seq_puts(seq, ",norecovery");
 509         if (nilfs_test_opt(sbi, DISCARD))
 510                 seq_puts(seq, ",discard");
 511
 512         return 0;
 513 }
 514
 515 static const struct super_operations nilfs_sops = {
 516         .alloc_inode    = nilfs_alloc_inode,
 517         .destroy_inode  = nilfs_destroy_inode,
 518         .dirty_inode    = nilfs_dirty_inode,
 519         /* .write_inode    = nilfs_write_inode, */
 520         /* .put_inode      = nilfs_put_inode, */
 521         /* .drop_inode    = nilfs_drop_inode, */
 522         .evict_inode    = nilfs_evict_inode,
 523         .put_super      = nilfs_put_super,
 524         /* .write_super    = nilfs_write_super, */
 525         .sync_fs        = nilfs_sync_fs,
 526         /* .write_super_lockfs */
 527         /* .unlockfs */
 528         .statfs         = nilfs_statfs,
 529         .remount_fs     = nilfs_remount,
 530         /* .umount_begin */
 531         .show_options = nilfs_show_options
 532 };
 533
 534 enum {
 535         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 536         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 537         Opt_discard, Opt_nodiscard, Opt_err,
 538 };
 539
 540 static match_table_t tokens = {
 541         {Opt_err_cont, "errors=continue"},
 542         {Opt_err_panic, "errors=panic"},
 543         {Opt_err_ro, "errors=remount-ro"},
 544         {Opt_barrier, "barrier"},
 545         {Opt_nobarrier, "nobarrier"},
 546         {Opt_snapshot, "cp=%u"},
 547         {Opt_order, "order=%s"},
 548         {Opt_norecovery, "norecovery"},
 549         {Opt_discard, "discard"},
 550         {Opt_nodiscard, "nodiscard"},
 551         {Opt_err, NULL}
 552 };
 553
 554 static int parse_options(char *options, struct super_block *sb, int is_remount)
 555 {
 556         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 557         char *p;
 558         substring_t args[MAX_OPT_ARGS];
 559
 560         if (!options)
 561                 return 1;
 562
 563         while ((p = strsep(&options, ",")) != NULL) {
 564                 int token;
 565                 if (!*p)
 566                         continue;
 567
 568                 token = match_token(p, tokens, args);
 569                 switch (token) {
 570                 case Opt_barrier:
 571                         nilfs_set_opt(sbi, BARRIER);
 572                         break;
 573                 case Opt_nobarrier:
 574                         nilfs_clear_opt(sbi, BARRIER);
 575                         break;
 576                 case Opt_order:
 577                         if (strcmp(args[0].from, "relaxed") == 0)
 578                                 /* Ordered data semantics */
 579                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 580                         else if (strcmp(args[0].from, "strict") == 0)
 581                                 /* Strict in-order semantics */
 582                                 nilfs_set_opt(sbi, STRICT_ORDER);
 583                         else
 584                                 return 0;
 585                         break;
 586                 case Opt_err_panic:
 587                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 588                         break;
 589                 case Opt_err_ro:
 590                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 591                         break;
 592                 case Opt_err_cont:
 593                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 594                         break;
 595                 case Opt_snapshot:
 596                         if (is_remount) {
 597                                 printk(KERN_ERR
 598                                        "NILFS: \"%s\" option is invalid "
 599                                        "for remount.\n", p);
 600                                 return 0;
 601                         }
 602                         break;
 603                 case Opt_norecovery:
 604                         nilfs_set_opt(sbi, NORECOVERY);
 605                         break;
 606                 case Opt_discard:
 607                         nilfs_set_opt(sbi, DISCARD);
 608                         break;
 609                 case Opt_nodiscard:
 610                         nilfs_clear_opt(sbi, DISCARD);
 611                         break;
 612                 default:
 613                         printk(KERN_ERR
 614                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 615                         return 0;
 616                 }
 617         }
 618         return 1;
 619 }
 620
 621 static inline void
 622 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 623                           struct nilfs_super_block *sbp)
 624 {
 625         sbi->s_mount_opt =
 626                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 627 }
 628
 629 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 630 {
 631         struct the_nilfs *nilfs = sbi->s_nilfs;
 632         struct nilfs_super_block **sbp;
 633         int max_mnt_count;
 634         int mnt_count;
 635
 636         /* nilfs->ns_sem must be locked by the caller. */
 637         sbp = nilfs_prepare_super(sbi, 0);
 638         if (!sbp)
 639                 return -EIO;
 640
 641         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 642         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 643
 644         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 645                 printk(KERN_WARNING
 646                        "NILFS warning: mounting fs with errors\n");
 647 #if 0
 648         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 649                 printk(KERN_WARNING
 650                        "NILFS warning: maximal mount count reached\n");
 651 #endif
 652         }
 653         if (!max_mnt_count)
 654                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 655
 656         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 657         sbp[0]->s_state =
 658                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 659         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 660         /* synchronize sbp[1] with sbp[0] */
 661         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 662         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 663 }
 664
 665 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 666                                                  u64 pos, int blocksize,
 667                                                  struct buffer_head **pbh)
 668 {
 669         unsigned long long sb_index = pos;
 670         unsigned long offset;
 671
 672         offset = do_div(sb_index, blocksize);
 673         *pbh = sb_bread(sb, sb_index);
 674         if (!*pbh)
 675                 return NULL;
 676         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 677 }
 678
 679 int nilfs_store_magic_and_option(struct super_block *sb,
 680                                  struct nilfs_super_block *sbp,
 681                                  char *data)
 682 {
 683         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 684
 685         sb->s_magic = le16_to_cpu(sbp->s_magic);
 686
 687         /* FS independent flags */
 688 #ifdef NILFS_ATIME_DISABLE
 689         sb->s_flags |= MS_NOATIME;
 690 #endif
 691
 692         nilfs_set_default_options(sbi, sbp);
 693
 694         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 695         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 696         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 697         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 698
 699         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 700 }
 701
 702 int nilfs_check_feature_compatibility(struct super_block *sb,
 703                                       struct nilfs_super_block *sbp)
 704 {
 705         __u64 features;
 706
 707         features = le64_to_cpu(sbp->s_feature_incompat) &
 708                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 709         if (features) {
 710                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 711                        "optional features (%llx)\n",
 712                        (unsigned long long)features);
 713                 return -EINVAL;
 714         }
 715         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 716                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 717         if (!(sb->s_flags & MS_RDONLY) && features) {
 718                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 719                        "unsupported optional features (%llx)\n",
 720                        (unsigned long long)features);
 721                 return -EINVAL;
 722         }
 723         return 0;
 724 }
 725
 726 static int nilfs_get_root_dentry(struct super_block *sb,
 727                                  struct nilfs_root *root,
 728                                  struct dentry **root_dentry)
 729 {
 730         struct inode *inode;
 731         struct dentry *dentry;
 732         int ret = 0;
 733
 734         inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
 735         if (IS_ERR(inode)) {
 736                 printk(KERN_ERR "NILFS: get root inode failed\n");
 737                 ret = PTR_ERR(inode);
 738                 goto out;
 739         }
 740         if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
 741                 iput(inode);
 742                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 743                 ret = -EINVAL;
 744                 goto out;
 745         }
 746
 747         if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
 748                 dentry = d_find_alias(inode);
 749                 if (!dentry) {
 750                         dentry = d_alloc_root(inode);
 751                         if (!dentry) {
 752                                 iput(inode);
 753                                 ret = -ENOMEM;
 754                                 goto failed_dentry;
 755                         }
 756                 } else {
 757                         iput(inode);
 758                 }
 759         } else {
 760                 dentry = d_obtain_alias(inode);
 761                 if (IS_ERR(dentry)) {
 762                         ret = PTR_ERR(dentry);
 763                         goto failed_dentry;
 764                 }
 765         }
 766         *root_dentry = dentry;
 767  out:
 768         return ret;
 769
 770  failed_dentry:
 771         printk(KERN_ERR "NILFS: get root dentry failed\n");
 772         goto out;
 773 }
 774
 775 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 776                                  struct dentry **root_dentry)
 777 {
 778         struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
 779         struct nilfs_root *root;
 780         int ret;
 781
 782         down_read(&nilfs->ns_segctor_sem);
 783         ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
 784         up_read(&nilfs->ns_segctor_sem);
 785         if (ret < 0) {
 786                 ret = (ret == -ENOENT) ? -EINVAL : ret;
 787                 goto out;
 788         } else if (!ret) {
 789                 printk(KERN_ERR "NILFS: The specified checkpoint is "
 790                        "not a snapshot (checkpoint number=%llu).\n",
 791                        (unsigned long long)cno);
 792                 ret = -EINVAL;
 793                 goto out;
 794         }
 795
 796         ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
 797         if (ret) {
 798                 printk(KERN_ERR "NILFS: error loading snapshot "
 799                        "(checkpoint number=%llu).\n",
 800                (unsigned long long)cno);
 801                 goto out;
 802         }
 803         ret = nilfs_get_root_dentry(s, root, root_dentry);
 804         nilfs_put_root(root);
 805  out:
 806         return ret;
 807 }
 808
 809 static int nilfs_tree_was_touched(struct dentry *root_dentry)
 810 {
 811         return atomic_read(&root_dentry->d_count) > 1;
 812 }
 813
 814 /**
 815  * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
 816  * @root_dentry: root dentry of the tree to be shrunk
 817  *
 818  * This function returns true if the tree was in-use.
 819  */
 820 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
 821 {
 822         if (have_submounts(root_dentry))
 823                 return true;
 824         shrink_dcache_parent(root_dentry);
 825         return nilfs_tree_was_touched(root_dentry);
 826 }
 827
 828 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
 829 {
 830         struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
 831         struct nilfs_root *root;
 832         struct inode *inode;
 833         struct dentry *dentry;
 834         int ret;
 835
 836         if (cno < 0 || cno > nilfs->ns_cno)
 837                 return false;
 838
 839         if (cno >= nilfs_last_cno(nilfs))
 840                 return true;    /* protect recent checkpoints */
 841
 842         ret = false;
 843         root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
 844         if (root) {
 845                 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
 846                 if (inode) {
 847                         dentry = d_find_alias(inode);
 848                         if (dentry) {
 849                                 if (nilfs_tree_was_touched(dentry))
 850                                         ret = nilfs_try_to_shrink_tree(dentry);
 851                                 dput(dentry);
 852                         }
 853                         iput(inode);
 854                 }
 855                 nilfs_put_root(root);
 856         }
 857         return ret;
 858 }
 859
 860 /**
 861  * nilfs_fill_super() - initialize a super block instance
 862  * @sb: super_block
 863  * @data: mount options
 864  * @silent: silent mode flag
 865  *
 866  * This function is called exclusively by nilfs->ns_mount_mutex.
 867  * So, the recovery process is protected from other simultaneous mounts.
 868  */
 869 static int
 870 nilfs_fill_super(struct super_block *sb, void *data, int silent)
 871 {
 872         struct the_nilfs *nilfs;
 873         struct nilfs_sb_info *sbi;
 874         struct nilfs_root *fsroot;
 875         __u64 cno;
 876         int err;
 877
 878         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 879         if (!sbi)
 880                 return -ENOMEM;
 881
 882         sb->s_fs_info = sbi;
 883         sbi->s_super = sb;
 884
 885         nilfs = alloc_nilfs(sb->s_bdev);
 886         if (!nilfs) {
 887                 err = -ENOMEM;
 888                 goto failed_sbi;
 889         }
 890         sbi->s_nilfs = nilfs;
 891
 892         err = init_nilfs(nilfs, sbi, (char *)data);
 893         if (err)
 894                 goto failed_nilfs;
 895
 896         spin_lock_init(&sbi->s_inode_lock);
 897         INIT_LIST_HEAD(&sbi->s_dirty_files);
 898
 899         /*
 900          * Following initialization is overlapped because
 901          * nilfs_sb_info structure has been cleared at the beginning.
 902          * But we reserve them to keep our interest and make ready
 903          * for the future change.
 904          */
 905         get_random_bytes(&sbi->s_next_generation,
 906                          sizeof(sbi->s_next_generation));
 907         spin_lock_init(&sbi->s_next_gen_lock);
 908
 909         sb->s_op = &nilfs_sops;
 910         sb->s_export_op = &nilfs_export_ops;
 911         sb->s_root = NULL;
 912         sb->s_time_gran = 1;
 913         sb->s_bdi = nilfs->ns_bdi;
 914
 915         err = load_nilfs(nilfs, sbi);
 916         if (err)
 917                 goto failed_nilfs;
 918
 919         cno = nilfs_last_cno(nilfs);
 920         err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
 921         if (err) {
 922                 printk(KERN_ERR "NILFS: error loading last checkpoint "
 923                        "(checkpoint number=%llu).\n", (unsigned long long)cno);
 924                 goto failed_unload;
 925         }
 926
 927         if (!(sb->s_flags & MS_RDONLY)) {
 928                 err = nilfs_attach_segment_constructor(sbi, fsroot);
 929                 if (err)
 930                         goto failed_checkpoint;
 931         }
 932
 933         err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
 934         if (err)
 935                 goto failed_segctor;
 936
 937         nilfs_put_root(fsroot);
 938
 939         if (!(sb->s_flags & MS_RDONLY)) {
 940                 down_write(&nilfs->ns_sem);
 941                 nilfs_setup_super(sbi);
 942                 up_write(&nilfs->ns_sem);
 943         }
 944
 945         return 0;
 946
 947  failed_segctor:
 948         nilfs_detach_segment_constructor(sbi);
 949
 950  failed_checkpoint:
 951         nilfs_put_root(fsroot);
 952
 953  failed_unload:
 954         iput(nilfs->ns_sufile);
 955         iput(nilfs->ns_cpfile);
 956         iput(nilfs->ns_dat);
 957
 958  failed_nilfs:
 959         destroy_nilfs(nilfs);
 960
 961  failed_sbi:
 962         sb->s_fs_info = NULL;
 963         kfree(sbi);
 964         return err;
 965 }
 966
 967 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 968 {
 969         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 970         struct the_nilfs *nilfs = sbi->s_nilfs;
 971         unsigned long old_sb_flags;
 972         struct nilfs_mount_options old_opts;
 973         int err;
 974
 975         old_sb_flags = sb->s_flags;
 976         old_opts.mount_opt = sbi->s_mount_opt;
 977
 978         if (!parse_options(data, sb, 1)) {
 979                 err = -EINVAL;
 980                 goto restore_opts;
 981         }
 982         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 983
 984         err = -EINVAL;
 985
 986         if (!nilfs_valid_fs(nilfs)) {
 987                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 988                        "remount because the filesystem is in an "
 989                        "incomplete recovery state.\n", sb->s_id);
 990                 goto restore_opts;
 991         }
 992
 993         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 994                 goto out;
 995         if (*flags & MS_RDONLY) {
 996                 /* Shutting down the segment constructor */
 997                 nilfs_detach_segment_constructor(sbi);
 998                 sb->s_flags |= MS_RDONLY;
 999
1000                 /*
1001                  * Remounting a valid RW partition RDONLY, so set
1002                  * the RDONLY flag and then mark the partition as valid again.
1003                  */
1004                 down_write(&nilfs->ns_sem);
1005                 nilfs_cleanup_super(sbi);
1006                 up_write(&nilfs->ns_sem);
1007         } else {
1008                 __u64 features;
1009                 struct nilfs_root *root;
1010
1011                 /*
1012                  * Mounting a RDONLY partition read-write, so reread and
1013                  * store the current valid flag.  (It may have been changed
1014                  * by fsck since we originally mounted the partition.)
1015                  */
1016                 down_read(&nilfs->ns_sem);
1017                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1018                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
1019                 up_read(&nilfs->ns_sem);
1020                 if (features) {
1021                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1022                                "remount RDWR because of unsupported optional "
1023                                "features (%llx)\n",
1024                                sb->s_id, (unsigned long long)features);
1025                         err = -EROFS;
1026                         goto restore_opts;
1027                 }
1028
1029                 sb->s_flags &= ~MS_RDONLY;
1030
1031                 root = NILFS_I(sb->s_root->d_inode)->i_root;
1032                 err = nilfs_attach_segment_constructor(sbi, root);
1033                 if (err)
1034                         goto restore_opts;
1035
1036                 down_write(&nilfs->ns_sem);
1037                 nilfs_setup_super(sbi);
1038                 up_write(&nilfs->ns_sem);
1039         }
1040  out:
1041         return 0;
1042
1043  restore_opts:
1044         sb->s_flags = old_sb_flags;
1045         sbi->s_mount_opt = old_opts.mount_opt;
1046         return err;
1047 }
1048
1049 struct nilfs_super_data {
1050         struct block_device *bdev;
1051         struct nilfs_sb_info *sbi;
1052         __u64 cno;
1053         int flags;
1054 };
1055
1056 /**
1057  * nilfs_identify - pre-read mount options needed to identify mount instance
1058  * @data: mount options
1059  * @sd: nilfs_super_data
1060  */
1061 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1062 {
1063         char *p, *options = data;
1064         substring_t args[MAX_OPT_ARGS];
1065         int token;
1066         int ret = 0;
1067
1068         do {
1069                 p = strsep(&options, ",");
1070                 if (p != NULL && *p) {
1071                         token = match_token(p, tokens, args);
1072                         if (token == Opt_snapshot) {
1073                                 if (!(sd->flags & MS_RDONLY)) {
1074                                         ret++;
1075                                 } else {
1076                                         sd->cno = simple_strtoull(args[0].from,
1077                                                                   NULL, 0);
1078                                         /*
1079                                          * No need to see the end pointer;
1080                                          * match_token() has done syntax
1081                                          * checking.
1082                                          */
1083                                         if (sd->cno == 0)
1084                                                 ret++;
1085                                 }
1086                         }
1087                         if (ret)
1088                                 printk(KERN_ERR
1089                                        "NILFS: invalid mount option: %s\n", p);
1090                 }
1091                 if (!options)
1092                         break;
1093                 BUG_ON(options == data);
1094                 *(options - 1) = ',';
1095         } while (!ret);
1096         return ret;
1097 }
1098
1099 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1100 {
1101         s->s_bdev = data;
1102         s->s_dev = s->s_bdev->bd_dev;
1103         return 0;
1104 }
1105
1106 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1107 {
1108         return (void *)s->s_bdev == data;
1109 }
1110
1111 static int
1112 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1113              const char *dev_name, void *data, struct vfsmount *mnt)
1114 {
1115         struct nilfs_super_data sd;
1116         struct super_block *s;
1117         fmode_t mode = FMODE_READ;
1118         struct dentry *root_dentry;
1119         int err, s_new = false;
1120
1121         if (!(flags & MS_RDONLY))
1122                 mode |= FMODE_WRITE;
1123
1124         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1125         if (IS_ERR(sd.bdev))
1126                 return PTR_ERR(sd.bdev);
1127
1128         sd.cno = 0;
1129         sd.flags = flags;
1130         if (nilfs_identify((char *)data, &sd)) {
1131                 err = -EINVAL;
1132                 goto failed;
1133         }
1134
1135         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1136         if (IS_ERR(s)) {
1137                 err = PTR_ERR(s);
1138                 goto failed;
1139         }
1140
1141         if (!s->s_root) {
1142                 char b[BDEVNAME_SIZE];
1143
1144                 s_new = true;
1145
1146                 /* New superblock instance created */
1147                 s->s_flags = flags;
1148                 s->s_mode = mode;
1149                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1150                 sb_set_blocksize(s, block_size(sd.bdev));
1151
1152                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1153                 if (err)
1154                         goto failed_super;
1155
1156                 s->s_flags |= MS_ACTIVE;
1157         } else if (!sd.cno) {
1158                 int busy = false;
1159
1160                 if (nilfs_tree_was_touched(s->s_root)) {
1161                         busy = nilfs_try_to_shrink_tree(s->s_root);
1162                         if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1163                                 printk(KERN_ERR "NILFS: the device already "
1164                                        "has a %s mount.\n",
1165                                        (s->s_flags & MS_RDONLY) ?
1166                                        "read-only" : "read/write");
1167                                 err = -EBUSY;
1168                                 goto failed_super;
1169                         }
1170                 }
1171                 if (!busy) {
1172                         /*
1173                          * Try remount to setup mount states if the current
1174                          * tree is not mounted and only snapshots use this sb.
1175                          */
1176                         err = nilfs_remount(s, &flags, data);
1177                         if (err)
1178                                 goto failed_super;
1179                 }
1180         }
1181
1182         if (sd.cno) {
1183                 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1184                 if (err)
1185                         goto failed_super;
1186         } else {
1187                 root_dentry = dget(s->s_root);
1188         }
1189
1190         if (!s_new)
1191                 close_bdev_exclusive(sd.bdev, mode);
1192
1193         mnt->mnt_sb = s;
1194         mnt->mnt_root = root_dentry;
1195         return 0;
1196
1197  failed_super:
1198         deactivate_locked_super(s);
1199
1200  failed:
1201         if (!s_new)
1202                 close_bdev_exclusive(sd.bdev, mode);
1203         return err;
1204 }
1205
1206 struct file_system_type nilfs_fs_type = {
1207         .owner    = THIS_MODULE,
1208         .name     = "nilfs2",
1209         .get_sb   = nilfs_get_sb,
1210         .kill_sb  = kill_block_super,
1211         .fs_flags = FS_REQUIRES_DEV,
1212 };
1213
1214 static void nilfs_inode_init_once(void *obj)
1215 {
1216         struct nilfs_inode_info *ii = obj;
1217
1218         INIT_LIST_HEAD(&ii->i_dirty);
1219 #ifdef CONFIG_NILFS_XATTR
1220         init_rwsem(&ii->xattr_sem);
1221 #endif
1222         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1223         ii->i_bmap = &ii->i_bmap_data;
1224         inode_init_once(&ii->vfs_inode);
1225 }
1226
1227 static void nilfs_segbuf_init_once(void *obj)
1228 {
1229         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1230 }
1231
1232 static void nilfs_destroy_cachep(void)
1233 {
1234         if (nilfs_inode_cachep)
1235                 kmem_cache_destroy(nilfs_inode_cachep);
1236         if (nilfs_transaction_cachep)
1237                 kmem_cache_destroy(nilfs_transaction_cachep);
1238         if (nilfs_segbuf_cachep)
1239                 kmem_cache_destroy(nilfs_segbuf_cachep);
1240         if (nilfs_btree_path_cache)
1241                 kmem_cache_destroy(nilfs_btree_path_cache);
1242 }
1243
1244 static int __init nilfs_init_cachep(void)
1245 {
1246         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1247                         sizeof(struct nilfs_inode_info), 0,
1248                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1249         if (!nilfs_inode_cachep)
1250                 goto fail;
1251
1252         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1253                         sizeof(struct nilfs_transaction_info), 0,
1254                         SLAB_RECLAIM_ACCOUNT, NULL);
1255         if (!nilfs_transaction_cachep)
1256                 goto fail;
1257
1258         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1259                         sizeof(struct nilfs_segment_buffer), 0,
1260                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1261         if (!nilfs_segbuf_cachep)
1262                 goto fail;
1263
1264         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1265                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1266                         0, 0, NULL);
1267         if (!nilfs_btree_path_cache)
1268                 goto fail;
1269
1270         return 0;
1271
1272 fail:
1273         nilfs_destroy_cachep();
1274         return -ENOMEM;
1275 }
1276
1277 static int __init init_nilfs_fs(void)
1278 {
1279         int err;
1280
1281         err = nilfs_init_cachep();
1282         if (err)
1283                 goto fail;
1284
1285         err = register_filesystem(&nilfs_fs_type);
1286         if (err)
1287                 goto free_cachep;
1288
1289         printk(KERN_INFO "NILFS version 2 loaded\n");
1290         return 0;
1291
1292 free_cachep:
1293         nilfs_destroy_cachep();
1294 fail:
1295         return err;
1296 }
1297
1298 static void __exit exit_nilfs_fs(void)
1299 {
1300         nilfs_destroy_cachep();
1301         unregister_filesystem(&nilfs_fs_type);
1302 }
1303
1304 module_init(init_nilfs_fs)
1305 module_exit(exit_nilfs_fs)