fs/nilfs2/super.c

   1 /*
   2  * super.c - NILFS module and super block management.
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21  */
  22 /*
  23  *  linux/fs/ext2/super.c
  24  *
  25  * Copyright (C) 1992, 1993, 1994, 1995
  26  * Remy Card (card@masi.ibp.fr)
  27  * Laboratoire MASI - Institut Blaise Pascal
  28  * Universite Pierre et Marie Curie (Paris VI)
  29  *
  30  *  from
  31  *
  32  *  linux/fs/minix/inode.c
  33  *
  34  *  Copyright (C) 1991, 1992  Linus Torvalds
  35  *
  36  *  Big-endian to little-endian byte-swapping/bitmaps by
  37  *        David S. Miller (davem@caip.rutgers.edu), 1995
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/string.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/parser.h>
  46 #include <linux/random.h>
  47 #include <linux/crc32.h>
  48 #include <linux/smp_lock.h>
  49 #include <linux/vfs.h>
  50 #include <linux/writeback.h>
  51 #include <linux/kobject.h>
  52 #include <linux/exportfs.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/mount.h>
  55 #include "nilfs.h"
  56 #include "mdt.h"
  57 #include "alloc.h"
  58 #include "page.h"
  59 #include "cpfile.h"
  60 #include "ifile.h"
  61 #include "dat.h"
  62 #include "segment.h"
  63 #include "segbuf.h"
  64
  65 MODULE_AUTHOR("NTT Corp.");
  66 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  67                    "(NILFS)");
  68 MODULE_LICENSE("GPL");
  69
  70 struct kmem_cache *nilfs_inode_cachep;
  71 struct kmem_cache *nilfs_transaction_cachep;
  72 struct kmem_cache *nilfs_segbuf_cachep;
  73 struct kmem_cache *nilfs_btree_path_cache;
  74
  75 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  76
  77 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  78 {
  79         struct the_nilfs *nilfs = sbi->s_nilfs;
  80         struct nilfs_super_block **sbp;
  81
  82         down_write(&nilfs->ns_sem);
  83         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  84                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  85                 sbp = nilfs_prepare_super(sbi, 0);
  86                 if (likely(sbp)) {
  87                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  88                         if (sbp[1])
  89                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  90                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  91                 }
  92         }
  93         up_write(&nilfs->ns_sem);
  94 }
  95
  96 /**
  97  * nilfs_error() - report failure condition on a filesystem
  98  *
  99  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 100  * reporting an error message.  It should be called when NILFS detects
 101  * incoherences or defects of meta data on disk.  As for sustainable
 102  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 103  * function should be used instead.
 104  *
 105  * The segment constructor must not call this function because it can
 106  * kill itself.
 107  */
 108 void nilfs_error(struct super_block *sb, const char *function,
 109                  const char *fmt, ...)
 110 {
 111         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 112         va_list args;
 113
 114         va_start(args, fmt);
 115         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 116         vprintk(fmt, args);
 117         printk("\n");
 118         va_end(args);
 119
 120         if (!(sb->s_flags & MS_RDONLY)) {
 121                 nilfs_set_error(sbi);
 122
 123                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 124                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 125                         sb->s_flags |= MS_RDONLY;
 126                 }
 127         }
 128
 129         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 130                 panic("NILFS (device %s): panic forced after error\n",
 131                       sb->s_id);
 132 }
 133
 134 void nilfs_warning(struct super_block *sb, const char *function,
 135                    const char *fmt, ...)
 136 {
 137         va_list args;
 138
 139         va_start(args, fmt);
 140         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 141                sb->s_id, function);
 142         vprintk(fmt, args);
 143         printk("\n");
 144         va_end(args);
 145 }
 146
 147
 148 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 149 {
 150         struct nilfs_inode_info *ii;
 151
 152         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 153         if (!ii)
 154                 return NULL;
 155         ii->i_bh = NULL;
 156         ii->i_state = 0;
 157         ii->vfs_inode.i_version = 1;
 158         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
 159         return &ii->vfs_inode;
 160 }
 161
 162 struct inode *nilfs_alloc_inode(struct super_block *sb)
 163 {
 164         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
 165 }
 166
 167 void nilfs_destroy_inode(struct inode *inode)
 168 {
 169         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 170 }
 171
 172 static void nilfs_clear_inode(struct inode *inode)
 173 {
 174         struct nilfs_inode_info *ii = NILFS_I(inode);
 175
 176         /*
 177          * Free resources allocated in nilfs_read_inode(), here.
 178          */
 179         BUG_ON(!list_empty(&ii->i_dirty));
 180         brelse(ii->i_bh);
 181         ii->i_bh = NULL;
 182
 183         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 184                 nilfs_bmap_clear(ii->i_bmap);
 185
 186         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 187 }
 188
 189 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 190 {
 191         struct the_nilfs *nilfs = sbi->s_nilfs;
 192         int err;
 193         int barrier_done = 0;
 194
 195         if (nilfs_test_opt(sbi, BARRIER)) {
 196                 set_buffer_ordered(nilfs->ns_sbh[0]);
 197                 barrier_done = 1;
 198         }
 199  retry:
 200         set_buffer_dirty(nilfs->ns_sbh[0]);
 201         err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 202         if (err == -EOPNOTSUPP && barrier_done) {
 203                 nilfs_warning(sbi->s_super, __func__,
 204                               "barrier-based sync failed. "
 205                               "disabling barriers\n");
 206                 nilfs_clear_opt(sbi, BARRIER);
 207                 barrier_done = 0;
 208                 clear_buffer_ordered(nilfs->ns_sbh[0]);
 209                 goto retry;
 210         }
 211         if (unlikely(err)) {
 212                 printk(KERN_ERR
 213                        "NILFS: unable to write superblock (err=%d)\n", err);
 214                 if (err == -EIO && nilfs->ns_sbh[1]) {
 215                         /*
 216                          * sbp[0] points to newer log than sbp[1],
 217                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 218                          */
 219                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 220                                nilfs->ns_sbsize);
 221                         nilfs_fall_back_super_block(nilfs);
 222                         goto retry;
 223                 }
 224         } else {
 225                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 226
 227                 nilfs->ns_sbwcount++;
 228
 229                 /*
 230                  * The latest segment becomes trailable from the position
 231                  * written in superblock.
 232                  */
 233                 clear_nilfs_discontinued(nilfs);
 234
 235                 /* update GC protection for recent segments */
 236                 if (nilfs->ns_sbh[1]) {
 237                         if (flag == NILFS_SB_COMMIT_ALL) {
 238                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 239                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 240                                         goto out;
 241                         }
 242                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 243                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 244                                 sbp = nilfs->ns_sbp[1];
 245                 }
 246
 247                 spin_lock(&nilfs->ns_last_segment_lock);
 248                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 249                 spin_unlock(&nilfs->ns_last_segment_lock);
 250         }
 251  out:
 252         return err;
 253 }
 254
 255 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 256                           struct the_nilfs *nilfs)
 257 {
 258         sector_t nfreeblocks;
 259
 260         /* nilfs->ns_sem must be locked by the caller. */
 261         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 262         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 263
 264         spin_lock(&nilfs->ns_last_segment_lock);
 265         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 266         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 267         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 268         spin_unlock(&nilfs->ns_last_segment_lock);
 269 }
 270
 271 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 272                                                int flip)
 273 {
 274         struct the_nilfs *nilfs = sbi->s_nilfs;
 275         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 276
 277         /* nilfs->ns_sem must be locked by the caller. */
 278         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 279                 if (sbp[1] &&
 280                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 281                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 282                 } else {
 283                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 284                                sbi->s_super->s_id);
 285                         return NULL;
 286                 }
 287         } else if (sbp[1] &&
 288                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 289                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 290         }
 291
 292         if (flip && sbp[1])
 293                 nilfs_swap_super_block(nilfs);
 294
 295         return sbp;
 296 }
 297
 298 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 299 {
 300         struct the_nilfs *nilfs = sbi->s_nilfs;
 301         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 302         time_t t;
 303
 304         /* nilfs->ns_sem must be locked by the caller. */
 305         t = get_seconds();
 306         nilfs->ns_sbwtime = t;
 307         sbp[0]->s_wtime = cpu_to_le64(t);
 308         sbp[0]->s_sum = 0;
 309         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 310                                              (unsigned char *)sbp[0],
 311                                              nilfs->ns_sbsize));
 312         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 313                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 314                 sbp[1]->s_sum = 0;
 315                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 316                                             (unsigned char *)sbp[1],
 317                                             nilfs->ns_sbsize));
 318         }
 319         clear_nilfs_sb_dirty(nilfs);
 320         return nilfs_sync_super(sbi, flag);
 321 }
 322
 323 /**
 324  * nilfs_cleanup_super() - write filesystem state for cleanup
 325  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 326  *
 327  * This function restores state flags in the on-disk super block.
 328  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 329  * filesystem was not clean previously.
 330  */
 331 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 332 {
 333         struct nilfs_super_block **sbp;
 334         int flag = NILFS_SB_COMMIT;
 335         int ret = -EIO;
 336
 337         sbp = nilfs_prepare_super(sbi, 0);
 338         if (sbp) {
 339                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 340                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 341                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 342                         /*
 343                          * make the "clean" flag also to the opposite
 344                          * super block if both super blocks point to
 345                          * the same checkpoint.
 346                          */
 347                         sbp[1]->s_state = sbp[0]->s_state;
 348                         flag = NILFS_SB_COMMIT_ALL;
 349                 }
 350                 ret = nilfs_commit_super(sbi, flag);
 351         }
 352         return ret;
 353 }
 354
 355 static void nilfs_put_super(struct super_block *sb)
 356 {
 357         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 358         struct the_nilfs *nilfs = sbi->s_nilfs;
 359
 360         lock_kernel();
 361
 362         nilfs_detach_segment_constructor(sbi);
 363
 364         if (!(sb->s_flags & MS_RDONLY)) {
 365                 down_write(&nilfs->ns_sem);
 366                 nilfs_cleanup_super(sbi);
 367                 up_write(&nilfs->ns_sem);
 368         }
 369         down_write(&nilfs->ns_super_sem);
 370         if (nilfs->ns_current == sbi)
 371                 nilfs->ns_current = NULL;
 372         up_write(&nilfs->ns_super_sem);
 373
 374         nilfs_detach_checkpoint(sbi);
 375         put_nilfs(sbi->s_nilfs);
 376         sbi->s_super = NULL;
 377         sb->s_fs_info = NULL;
 378         nilfs_put_sbinfo(sbi);
 379
 380         unlock_kernel();
 381 }
 382
 383 static int nilfs_sync_fs(struct super_block *sb, int wait)
 384 {
 385         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 386         struct the_nilfs *nilfs = sbi->s_nilfs;
 387         struct nilfs_super_block **sbp;
 388         int err = 0;
 389
 390         /* This function is called when super block should be written back */
 391         if (wait)
 392                 err = nilfs_construct_segment(sb);
 393
 394         down_write(&nilfs->ns_sem);
 395         if (nilfs_sb_dirty(nilfs)) {
 396                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 397                 if (likely(sbp)) {
 398                         nilfs_set_log_cursor(sbp[0], nilfs);
 399                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 400                 }
 401         }
 402         up_write(&nilfs->ns_sem);
 403
 404         return err;
 405 }
 406
 407 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
 408 {
 409         struct the_nilfs *nilfs = sbi->s_nilfs;
 410         struct nilfs_checkpoint *raw_cp;
 411         struct buffer_head *bh_cp;
 412         int err;
 413
 414         down_write(&nilfs->ns_super_sem);
 415         list_add(&sbi->s_list, &nilfs->ns_supers);
 416         up_write(&nilfs->ns_super_sem);
 417
 418         sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
 419         if (!sbi->s_ifile)
 420                 return -ENOMEM;
 421
 422         down_read(&nilfs->ns_segctor_sem);
 423         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 424                                           &bh_cp);
 425         up_read(&nilfs->ns_segctor_sem);
 426         if (unlikely(err)) {
 427                 if (err == -ENOENT || err == -EINVAL) {
 428                         printk(KERN_ERR
 429                                "NILFS: Invalid checkpoint "
 430                                "(checkpoint number=%llu)\n",
 431                                (unsigned long long)cno);
 432                         err = -EINVAL;
 433                 }
 434                 goto failed;
 435         }
 436         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
 437         if (unlikely(err))
 438                 goto failed_bh;
 439         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 440         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 441
 442         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 443         return 0;
 444
 445  failed_bh:
 446         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 447  failed:
 448         nilfs_mdt_destroy(sbi->s_ifile);
 449         sbi->s_ifile = NULL;
 450
 451         down_write(&nilfs->ns_super_sem);
 452         list_del_init(&sbi->s_list);
 453         up_write(&nilfs->ns_super_sem);
 454
 455         return err;
 456 }
 457
 458 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
 459 {
 460         struct the_nilfs *nilfs = sbi->s_nilfs;
 461
 462         nilfs_mdt_destroy(sbi->s_ifile);
 463         sbi->s_ifile = NULL;
 464         down_write(&nilfs->ns_super_sem);
 465         list_del_init(&sbi->s_list);
 466         up_write(&nilfs->ns_super_sem);
 467 }
 468
 469 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 470 {
 471         struct super_block *sb = dentry->d_sb;
 472         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 473         struct the_nilfs *nilfs = sbi->s_nilfs;
 474         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 475         unsigned long long blocks;
 476         unsigned long overhead;
 477         unsigned long nrsvblocks;
 478         sector_t nfreeblocks;
 479         int err;
 480
 481         /*
 482          * Compute all of the segment blocks
 483          *
 484          * The blocks before first segment and after last segment
 485          * are excluded.
 486          */
 487         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 488                 - nilfs->ns_first_data_block;
 489         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 490
 491         /*
 492          * Compute the overhead
 493          *
 494          * When distributing meta data blocks outside segment structure,
 495          * We must count them as the overhead.
 496          */
 497         overhead = 0;
 498
 499         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 500         if (unlikely(err))
 501                 return err;
 502
 503         buf->f_type = NILFS_SUPER_MAGIC;
 504         buf->f_bsize = sb->s_blocksize;
 505         buf->f_blocks = blocks - overhead;
 506         buf->f_bfree = nfreeblocks;
 507         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 508                 (buf->f_bfree - nrsvblocks) : 0;
 509         buf->f_files = atomic_read(&sbi->s_inodes_count);
 510         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 511         buf->f_namelen = NILFS_NAME_LEN;
 512         buf->f_fsid.val[0] = (u32)id;
 513         buf->f_fsid.val[1] = (u32)(id >> 32);
 514
 515         return 0;
 516 }
 517
 518 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 519 {
 520         struct super_block *sb = vfs->mnt_sb;
 521         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 522
 523         if (!nilfs_test_opt(sbi, BARRIER))
 524                 seq_printf(seq, ",nobarrier");
 525         if (nilfs_test_opt(sbi, SNAPSHOT))
 526                 seq_printf(seq, ",cp=%llu",
 527                            (unsigned long long int)sbi->s_snapshot_cno);
 528         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 529                 seq_printf(seq, ",errors=panic");
 530         if (nilfs_test_opt(sbi, ERRORS_CONT))
 531                 seq_printf(seq, ",errors=continue");
 532         if (nilfs_test_opt(sbi, STRICT_ORDER))
 533                 seq_printf(seq, ",order=strict");
 534         if (nilfs_test_opt(sbi, NORECOVERY))
 535                 seq_printf(seq, ",norecovery");
 536         if (nilfs_test_opt(sbi, DISCARD))
 537                 seq_printf(seq, ",discard");
 538
 539         return 0;
 540 }
 541
 542 static const struct super_operations nilfs_sops = {
 543         .alloc_inode    = nilfs_alloc_inode,
 544         .destroy_inode  = nilfs_destroy_inode,
 545         .dirty_inode    = nilfs_dirty_inode,
 546         /* .write_inode    = nilfs_write_inode, */
 547         /* .put_inode      = nilfs_put_inode, */
 548         /* .drop_inode    = nilfs_drop_inode, */
 549         .delete_inode   = nilfs_delete_inode,
 550         .put_super      = nilfs_put_super,
 551         /* .write_super    = nilfs_write_super, */
 552         .sync_fs        = nilfs_sync_fs,
 553         /* .write_super_lockfs */
 554         /* .unlockfs */
 555         .statfs         = nilfs_statfs,
 556         .remount_fs     = nilfs_remount,
 557         .clear_inode    = nilfs_clear_inode,
 558         /* .umount_begin */
 559         .show_options = nilfs_show_options
 560 };
 561
 562 static struct inode *
 563 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 564 {
 565         struct inode *inode;
 566
 567         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
 568             ino != NILFS_SKETCH_INO)
 569                 return ERR_PTR(-ESTALE);
 570
 571         inode = nilfs_iget(sb, ino);
 572         if (IS_ERR(inode))
 573                 return ERR_CAST(inode);
 574         if (generation && inode->i_generation != generation) {
 575                 iput(inode);
 576                 return ERR_PTR(-ESTALE);
 577         }
 578
 579         return inode;
 580 }
 581
 582 static struct dentry *
 583 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
 584                    int fh_type)
 585 {
 586         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 587                                     nilfs_nfs_get_inode);
 588 }
 589
 590 static struct dentry *
 591 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
 592                    int fh_type)
 593 {
 594         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 595                                     nilfs_nfs_get_inode);
 596 }
 597
 598 static const struct export_operations nilfs_export_ops = {
 599         .fh_to_dentry = nilfs_fh_to_dentry,
 600         .fh_to_parent = nilfs_fh_to_parent,
 601         .get_parent = nilfs_get_parent,
 602 };
 603
 604 enum {
 605         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 606         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 607         Opt_discard, Opt_err,
 608 };
 609
 610 static match_table_t tokens = {
 611         {Opt_err_cont, "errors=continue"},
 612         {Opt_err_panic, "errors=panic"},
 613         {Opt_err_ro, "errors=remount-ro"},
 614         {Opt_barrier, "barrier"},
 615         {Opt_nobarrier, "nobarrier"},
 616         {Opt_snapshot, "cp=%u"},
 617         {Opt_order, "order=%s"},
 618         {Opt_norecovery, "norecovery"},
 619         {Opt_discard, "discard"},
 620         {Opt_err, NULL}
 621 };
 622
 623 static int parse_options(char *options, struct super_block *sb)
 624 {
 625         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 626         char *p;
 627         substring_t args[MAX_OPT_ARGS];
 628         int option;
 629
 630         if (!options)
 631                 return 1;
 632
 633         while ((p = strsep(&options, ",")) != NULL) {
 634                 int token;
 635                 if (!*p)
 636                         continue;
 637
 638                 token = match_token(p, tokens, args);
 639                 switch (token) {
 640                 case Opt_barrier:
 641                         nilfs_set_opt(sbi, BARRIER);
 642                         break;
 643                 case Opt_nobarrier:
 644                         nilfs_clear_opt(sbi, BARRIER);
 645                         break;
 646                 case Opt_order:
 647                         if (strcmp(args[0].from, "relaxed") == 0)
 648                                 /* Ordered data semantics */
 649                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 650                         else if (strcmp(args[0].from, "strict") == 0)
 651                                 /* Strict in-order semantics */
 652                                 nilfs_set_opt(sbi, STRICT_ORDER);
 653                         else
 654                                 return 0;
 655                         break;
 656                 case Opt_err_panic:
 657                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 658                         break;
 659                 case Opt_err_ro:
 660                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 661                         break;
 662                 case Opt_err_cont:
 663                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 664                         break;
 665                 case Opt_snapshot:
 666                         if (match_int(&args[0], &option) || option <= 0)
 667                                 return 0;
 668                         if (!(sb->s_flags & MS_RDONLY))
 669                                 return 0;
 670                         sbi->s_snapshot_cno = option;
 671                         nilfs_set_opt(sbi, SNAPSHOT);
 672                         break;
 673                 case Opt_norecovery:
 674                         nilfs_set_opt(sbi, NORECOVERY);
 675                         break;
 676                 case Opt_discard:
 677                         nilfs_set_opt(sbi, DISCARD);
 678                         break;
 679                 default:
 680                         printk(KERN_ERR
 681                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 682                         return 0;
 683                 }
 684         }
 685         return 1;
 686 }
 687
 688 static inline void
 689 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 690                           struct nilfs_super_block *sbp)
 691 {
 692         sbi->s_mount_opt =
 693                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 694 }
 695
 696 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 697 {
 698         struct the_nilfs *nilfs = sbi->s_nilfs;
 699         struct nilfs_super_block **sbp;
 700         int max_mnt_count;
 701         int mnt_count;
 702
 703         /* nilfs->ns_sem must be locked by the caller. */
 704         sbp = nilfs_prepare_super(sbi, 0);
 705         if (!sbp)
 706                 return -EIO;
 707
 708         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 709         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 710
 711         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 712                 printk(KERN_WARNING
 713                        "NILFS warning: mounting fs with errors\n");
 714 #if 0
 715         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 716                 printk(KERN_WARNING
 717                        "NILFS warning: maximal mount count reached\n");
 718 #endif
 719         }
 720         if (!max_mnt_count)
 721                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 722
 723         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 724         sbp[0]->s_state =
 725                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 726         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 727         /* synchronize sbp[1] with sbp[0] */
 728         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 729         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 730 }
 731
 732 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 733                                                  u64 pos, int blocksize,
 734                                                  struct buffer_head **pbh)
 735 {
 736         unsigned long long sb_index = pos;
 737         unsigned long offset;
 738
 739         offset = do_div(sb_index, blocksize);
 740         *pbh = sb_bread(sb, sb_index);
 741         if (!*pbh)
 742                 return NULL;
 743         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 744 }
 745
 746 int nilfs_store_magic_and_option(struct super_block *sb,
 747                                  struct nilfs_super_block *sbp,
 748                                  char *data)
 749 {
 750         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 751
 752         sb->s_magic = le16_to_cpu(sbp->s_magic);
 753
 754         /* FS independent flags */
 755 #ifdef NILFS_ATIME_DISABLE
 756         sb->s_flags |= MS_NOATIME;
 757 #endif
 758
 759         nilfs_set_default_options(sbi, sbp);
 760
 761         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 762         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 763         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 764         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 765
 766         return !parse_options(data, sb) ? -EINVAL : 0 ;
 767 }
 768
 769 /**
 770  * nilfs_fill_super() - initialize a super block instance
 771  * @sb: super_block
 772  * @data: mount options
 773  * @silent: silent mode flag
 774  * @nilfs: the_nilfs struct
 775  *
 776  * This function is called exclusively by nilfs->ns_mount_mutex.
 777  * So, the recovery process is protected from other simultaneous mounts.
 778  */
 779 static int
 780 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 781                  struct the_nilfs *nilfs)
 782 {
 783         struct nilfs_sb_info *sbi;
 784         struct inode *root;
 785         __u64 cno;
 786         int err;
 787
 788         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 789         if (!sbi)
 790                 return -ENOMEM;
 791
 792         sb->s_fs_info = sbi;
 793
 794         get_nilfs(nilfs);
 795         sbi->s_nilfs = nilfs;
 796         sbi->s_super = sb;
 797         atomic_set(&sbi->s_count, 1);
 798
 799         err = init_nilfs(nilfs, sbi, (char *)data);
 800         if (err)
 801                 goto failed_sbi;
 802
 803         spin_lock_init(&sbi->s_inode_lock);
 804         INIT_LIST_HEAD(&sbi->s_dirty_files);
 805         INIT_LIST_HEAD(&sbi->s_list);
 806
 807         /*
 808          * Following initialization is overlapped because
 809          * nilfs_sb_info structure has been cleared at the beginning.
 810          * But we reserve them to keep our interest and make ready
 811          * for the future change.
 812          */
 813         get_random_bytes(&sbi->s_next_generation,
 814                          sizeof(sbi->s_next_generation));
 815         spin_lock_init(&sbi->s_next_gen_lock);
 816
 817         sb->s_op = &nilfs_sops;
 818         sb->s_export_op = &nilfs_export_ops;
 819         sb->s_root = NULL;
 820         sb->s_time_gran = 1;
 821         sb->s_bdi = nilfs->ns_bdi;
 822
 823         err = load_nilfs(nilfs, sbi);
 824         if (err)
 825                 goto failed_sbi;
 826
 827         cno = nilfs_last_cno(nilfs);
 828
 829         if (sb->s_flags & MS_RDONLY) {
 830                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 831                         down_read(&nilfs->ns_segctor_sem);
 832                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
 833                                                        sbi->s_snapshot_cno);
 834                         up_read(&nilfs->ns_segctor_sem);
 835                         if (err < 0) {
 836                                 if (err == -ENOENT)
 837                                         err = -EINVAL;
 838                                 goto failed_sbi;
 839                         }
 840                         if (!err) {
 841                                 printk(KERN_ERR
 842                                        "NILFS: The specified checkpoint is "
 843                                        "not a snapshot "
 844                                        "(checkpoint number=%llu).\n",
 845                                        (unsigned long long)sbi->s_snapshot_cno);
 846                                 err = -EINVAL;
 847                                 goto failed_sbi;
 848                         }
 849                         cno = sbi->s_snapshot_cno;
 850                 }
 851         }
 852
 853         err = nilfs_attach_checkpoint(sbi, cno);
 854         if (err) {
 855                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 856                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 857                 goto failed_sbi;
 858         }
 859
 860         if (!(sb->s_flags & MS_RDONLY)) {
 861                 err = nilfs_attach_segment_constructor(sbi);
 862                 if (err)
 863                         goto failed_checkpoint;
 864         }
 865
 866         root = nilfs_iget(sb, NILFS_ROOT_INO);
 867         if (IS_ERR(root)) {
 868                 printk(KERN_ERR "NILFS: get root inode failed\n");
 869                 err = PTR_ERR(root);
 870                 goto failed_segctor;
 871         }
 872         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 873                 iput(root);
 874                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 875                 err = -EINVAL;
 876                 goto failed_segctor;
 877         }
 878         sb->s_root = d_alloc_root(root);
 879         if (!sb->s_root) {
 880                 iput(root);
 881                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 882                 err = -ENOMEM;
 883                 goto failed_segctor;
 884         }
 885
 886         if (!(sb->s_flags & MS_RDONLY)) {
 887                 down_write(&nilfs->ns_sem);
 888                 nilfs_setup_super(sbi);
 889                 up_write(&nilfs->ns_sem);
 890         }
 891
 892         down_write(&nilfs->ns_super_sem);
 893         if (!nilfs_test_opt(sbi, SNAPSHOT))
 894                 nilfs->ns_current = sbi;
 895         up_write(&nilfs->ns_super_sem);
 896
 897         return 0;
 898
 899  failed_segctor:
 900         nilfs_detach_segment_constructor(sbi);
 901
 902  failed_checkpoint:
 903         nilfs_detach_checkpoint(sbi);
 904
 905  failed_sbi:
 906         put_nilfs(nilfs);
 907         sb->s_fs_info = NULL;
 908         nilfs_put_sbinfo(sbi);
 909         return err;
 910 }
 911
 912 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 913 {
 914         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 915         struct the_nilfs *nilfs = sbi->s_nilfs;
 916         unsigned long old_sb_flags;
 917         struct nilfs_mount_options old_opts;
 918         int was_snapshot, err;
 919
 920         lock_kernel();
 921
 922         down_write(&nilfs->ns_super_sem);
 923         old_sb_flags = sb->s_flags;
 924         old_opts.mount_opt = sbi->s_mount_opt;
 925         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 926         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 927
 928         if (!parse_options(data, sb)) {
 929                 err = -EINVAL;
 930                 goto restore_opts;
 931         }
 932         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 933
 934         err = -EINVAL;
 935         if (was_snapshot) {
 936                 if (!(*flags & MS_RDONLY)) {
 937                         printk(KERN_ERR "NILFS (device %s): cannot remount "
 938                                "snapshot read/write.\n",
 939                                sb->s_id);
 940                         goto restore_opts;
 941                 } else if (sbi->s_snapshot_cno != old_opts.snapshot_cno) {
 942                         printk(KERN_ERR "NILFS (device %s): cannot "
 943                                "remount to a different snapshot.\n",
 944                                sb->s_id);
 945                         goto restore_opts;
 946                 }
 947         } else {
 948                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 949                         printk(KERN_ERR "NILFS (device %s): cannot change "
 950                                "a regular mount to a snapshot.\n",
 951                                sb->s_id);
 952                         goto restore_opts;
 953                 }
 954         }
 955
 956         if (!nilfs_valid_fs(nilfs)) {
 957                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 958                        "remount because the filesystem is in an "
 959                        "incomplete recovery state.\n", sb->s_id);
 960                 goto restore_opts;
 961         }
 962
 963         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 964                 goto out;
 965         if (*flags & MS_RDONLY) {
 966                 /* Shutting down the segment constructor */
 967                 nilfs_detach_segment_constructor(sbi);
 968                 sb->s_flags |= MS_RDONLY;
 969
 970                 /*
 971                  * Remounting a valid RW partition RDONLY, so set
 972                  * the RDONLY flag and then mark the partition as valid again.
 973                  */
 974                 down_write(&nilfs->ns_sem);
 975                 nilfs_cleanup_super(sbi);
 976                 up_write(&nilfs->ns_sem);
 977         } else {
 978                 /*
 979                  * Mounting a RDONLY partition read-write, so reread and
 980                  * store the current valid flag.  (It may have been changed
 981                  * by fsck since we originally mounted the partition.)
 982                  */
 983                 sb->s_flags &= ~MS_RDONLY;
 984
 985                 err = nilfs_attach_segment_constructor(sbi);
 986                 if (err)
 987                         goto restore_opts;
 988
 989                 down_write(&nilfs->ns_sem);
 990                 nilfs_setup_super(sbi);
 991                 up_write(&nilfs->ns_sem);
 992         }
 993  out:
 994         up_write(&nilfs->ns_super_sem);
 995         unlock_kernel();
 996         return 0;
 997
 998  restore_opts:
 999         sb->s_flags = old_sb_flags;
1000         sbi->s_mount_opt = old_opts.mount_opt;
1001         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1002         up_write(&nilfs->ns_super_sem);
1003         unlock_kernel();
1004         return err;
1005 }
1006
1007 struct nilfs_super_data {
1008         struct block_device *bdev;
1009         struct nilfs_sb_info *sbi;
1010         __u64 cno;
1011         int flags;
1012 };
1013
1014 /**
1015  * nilfs_identify - pre-read mount options needed to identify mount instance
1016  * @data: mount options
1017  * @sd: nilfs_super_data
1018  */
1019 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1020 {
1021         char *p, *options = data;
1022         substring_t args[MAX_OPT_ARGS];
1023         int option, token;
1024         int ret = 0;
1025
1026         do {
1027                 p = strsep(&options, ",");
1028                 if (p != NULL && *p) {
1029                         token = match_token(p, tokens, args);
1030                         if (token == Opt_snapshot) {
1031                                 if (!(sd->flags & MS_RDONLY))
1032                                         ret++;
1033                                 else {
1034                                         ret = match_int(&args[0], &option);
1035                                         if (!ret) {
1036                                                 if (option > 0)
1037                                                         sd->cno = option;
1038                                                 else
1039                                                         ret++;
1040                                         }
1041                                 }
1042                         }
1043                         if (ret)
1044                                 printk(KERN_ERR
1045                                        "NILFS: invalid mount option: %s\n", p);
1046                 }
1047                 if (!options)
1048                         break;
1049                 BUG_ON(options == data);
1050                 *(options - 1) = ',';
1051         } while (!ret);
1052         return ret;
1053 }
1054
1055 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1056 {
1057         struct nilfs_super_data *sd = data;
1058
1059         s->s_bdev = sd->bdev;
1060         s->s_dev = s->s_bdev->bd_dev;
1061         return 0;
1062 }
1063
1064 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1065 {
1066         struct nilfs_super_data *sd = data;
1067
1068         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1069 }
1070
1071 static int
1072 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1073              const char *dev_name, void *data, struct vfsmount *mnt)
1074 {
1075         struct nilfs_super_data sd;
1076         struct super_block *s;
1077         fmode_t mode = FMODE_READ;
1078         struct the_nilfs *nilfs;
1079         int err, need_to_close = 1;
1080
1081         if (!(flags & MS_RDONLY))
1082                 mode |= FMODE_WRITE;
1083
1084         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1085         if (IS_ERR(sd.bdev))
1086                 return PTR_ERR(sd.bdev);
1087
1088         /*
1089          * To get mount instance using sget() vfs-routine, NILFS needs
1090          * much more information than normal filesystems to identify mount
1091          * instance.  For snapshot mounts, not only a mount type (ro-mount
1092          * or rw-mount) but also a checkpoint number is required.
1093          */
1094         sd.cno = 0;
1095         sd.flags = flags;
1096         if (nilfs_identify((char *)data, &sd)) {
1097                 err = -EINVAL;
1098                 goto failed;
1099         }
1100
1101         nilfs = find_or_create_nilfs(sd.bdev);
1102         if (!nilfs) {
1103                 err = -ENOMEM;
1104                 goto failed;
1105         }
1106
1107         mutex_lock(&nilfs->ns_mount_mutex);
1108
1109         if (!sd.cno) {
1110                 /*
1111                  * Check if an exclusive mount exists or not.
1112                  * Snapshot mounts coexist with a current mount
1113                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1114                  * ro-mount are mutually exclusive.
1115                  */
1116                 down_read(&nilfs->ns_super_sem);
1117                 if (nilfs->ns_current &&
1118                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1119                      & MS_RDONLY)) {
1120                         up_read(&nilfs->ns_super_sem);
1121                         err = -EBUSY;
1122                         goto failed_unlock;
1123                 }
1124                 up_read(&nilfs->ns_super_sem);
1125         }
1126
1127         /*
1128          * Find existing nilfs_sb_info struct
1129          */
1130         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1131
1132         /*
1133          * Get super block instance holding the nilfs_sb_info struct.
1134          * A new instance is allocated if no existing mount is present or
1135          * existing instance has been unmounted.
1136          */
1137         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1138         if (sd.sbi)
1139                 nilfs_put_sbinfo(sd.sbi);
1140
1141         if (IS_ERR(s)) {
1142                 err = PTR_ERR(s);
1143                 goto failed_unlock;
1144         }
1145
1146         if (!s->s_root) {
1147                 char b[BDEVNAME_SIZE];
1148
1149                 /* New superblock instance created */
1150                 s->s_flags = flags;
1151                 s->s_mode = mode;
1152                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1153                 sb_set_blocksize(s, block_size(sd.bdev));
1154
1155                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1156                                        nilfs);
1157                 if (err)
1158                         goto cancel_new;
1159
1160                 s->s_flags |= MS_ACTIVE;
1161                 need_to_close = 0;
1162         }
1163
1164         mutex_unlock(&nilfs->ns_mount_mutex);
1165         put_nilfs(nilfs);
1166         if (need_to_close)
1167                 close_bdev_exclusive(sd.bdev, mode);
1168         simple_set_mnt(mnt, s);
1169         return 0;
1170
1171  failed_unlock:
1172         mutex_unlock(&nilfs->ns_mount_mutex);
1173         put_nilfs(nilfs);
1174  failed:
1175         close_bdev_exclusive(sd.bdev, mode);
1176
1177         return err;
1178
1179  cancel_new:
1180         /* Abandoning the newly allocated superblock */
1181         mutex_unlock(&nilfs->ns_mount_mutex);
1182         put_nilfs(nilfs);
1183         deactivate_locked_super(s);
1184         /*
1185          * deactivate_locked_super() invokes close_bdev_exclusive().
1186          * We must finish all post-cleaning before this call;
1187          * put_nilfs() needs the block device.
1188          */
1189         return err;
1190 }
1191
1192 struct file_system_type nilfs_fs_type = {
1193         .owner    = THIS_MODULE,
1194         .name     = "nilfs2",
1195         .get_sb   = nilfs_get_sb,
1196         .kill_sb  = kill_block_super,
1197         .fs_flags = FS_REQUIRES_DEV,
1198 };
1199
1200 static void nilfs_inode_init_once(void *obj)
1201 {
1202         struct nilfs_inode_info *ii = obj;
1203
1204         INIT_LIST_HEAD(&ii->i_dirty);
1205 #ifdef CONFIG_NILFS_XATTR
1206         init_rwsem(&ii->xattr_sem);
1207 #endif
1208         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1209         ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
1210         inode_init_once(&ii->vfs_inode);
1211 }
1212
1213 static void nilfs_segbuf_init_once(void *obj)
1214 {
1215         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1216 }
1217
1218 static void nilfs_destroy_cachep(void)
1219 {
1220         if (nilfs_inode_cachep)
1221                 kmem_cache_destroy(nilfs_inode_cachep);
1222         if (nilfs_transaction_cachep)
1223                 kmem_cache_destroy(nilfs_transaction_cachep);
1224         if (nilfs_segbuf_cachep)
1225                 kmem_cache_destroy(nilfs_segbuf_cachep);
1226         if (nilfs_btree_path_cache)
1227                 kmem_cache_destroy(nilfs_btree_path_cache);
1228 }
1229
1230 static int __init nilfs_init_cachep(void)
1231 {
1232         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1233                         sizeof(struct nilfs_inode_info), 0,
1234                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1235         if (!nilfs_inode_cachep)
1236                 goto fail;
1237
1238         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1239                         sizeof(struct nilfs_transaction_info), 0,
1240                         SLAB_RECLAIM_ACCOUNT, NULL);
1241         if (!nilfs_transaction_cachep)
1242                 goto fail;
1243
1244         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1245                         sizeof(struct nilfs_segment_buffer), 0,
1246                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1247         if (!nilfs_segbuf_cachep)
1248                 goto fail;
1249
1250         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1251                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1252                         0, 0, NULL);
1253         if (!nilfs_btree_path_cache)
1254                 goto fail;
1255
1256         return 0;
1257
1258 fail:
1259         nilfs_destroy_cachep();
1260         return -ENOMEM;
1261 }
1262
1263 static int __init init_nilfs_fs(void)
1264 {
1265         int err;
1266
1267         err = nilfs_init_cachep();
1268         if (err)
1269                 goto fail;
1270
1271         err = register_filesystem(&nilfs_fs_type);
1272         if (err)
1273                 goto free_cachep;
1274
1275         printk(KERN_INFO "NILFS version 2 loaded\n");
1276         return 0;
1277
1278 free_cachep:
1279         nilfs_destroy_cachep();
1280 fail:
1281         return err;
1282 }
1283
1284 static void __exit exit_nilfs_fs(void)
1285 {
1286         nilfs_destroy_cachep();
1287         unregister_filesystem(&nilfs_fs_type);
1288 }
1289
1290 module_init(init_nilfs_fs)
1291 module_exit(exit_nilfs_fs)