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/crc32.h>
  47 #include <linux/vfs.h>
  48 #include <linux/writeback.h>
  49 #include <linux/seq_file.h>
  50 #include <linux/mount.h>
  51 #include "nilfs.h"
  52 #include "export.h"
  53 #include "mdt.h"
  54 #include "alloc.h"
  55 #include "btree.h"
  56 #include "btnode.h"
  57 #include "page.h"
  58 #include "cpfile.h"
  59 #include "ifile.h"
  60 #include "dat.h"
  61 #include "segment.h"
  62 #include "segbuf.h"
  63
  64 MODULE_AUTHOR("NTT Corp.");
  65 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  66                    "(NILFS)");
  67 MODULE_LICENSE("GPL");
  68
  69 static struct kmem_cache *nilfs_inode_cachep;
  70 struct kmem_cache *nilfs_transaction_cachep;
  71 struct kmem_cache *nilfs_segbuf_cachep;
  72 struct kmem_cache *nilfs_btree_path_cache;
  73
  74 static int nilfs_setup_super(struct super_block *sb, int is_mount);
  75 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  76
  77 static void nilfs_set_error(struct super_block *sb)
  78 {
  79         struct the_nilfs *nilfs = sb->s_fs_info;
  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(sb, 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(sb, 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 the_nilfs *nilfs = sb->s_fs_info;
 112         struct va_format vaf;
 113         va_list args;
 114
 115         va_start(args, fmt);
 116
 117         vaf.fmt = fmt;
 118         vaf.va = &args;
 119
 120         printk(KERN_CRIT "NILFS error (device %s): %s: %pV\n",
 121                sb->s_id, function, &vaf);
 122
 123         va_end(args);
 124
 125         if (!(sb->s_flags & MS_RDONLY)) {
 126                 nilfs_set_error(sb);
 127
 128                 if (nilfs_test_opt(nilfs, ERRORS_RO)) {
 129                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 130                         sb->s_flags |= MS_RDONLY;
 131                 }
 132         }
 133
 134         if (nilfs_test_opt(nilfs, ERRORS_PANIC))
 135                 panic("NILFS (device %s): panic forced after error\n",
 136                       sb->s_id);
 137 }
 138
 139 void nilfs_warning(struct super_block *sb, const char *function,
 140                    const char *fmt, ...)
 141 {
 142         struct va_format vaf;
 143         va_list args;
 144
 145         va_start(args, fmt);
 146
 147         vaf.fmt = fmt;
 148         vaf.va = &args;
 149
 150         printk(KERN_WARNING "NILFS warning (device %s): %s: %pV\n",
 151                sb->s_id, function, &vaf);
 152
 153         va_end(args);
 154 }
 155
 156
 157 struct inode *nilfs_alloc_inode(struct super_block *sb)
 158 {
 159         struct nilfs_inode_info *ii;
 160
 161         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 162         if (!ii)
 163                 return NULL;
 164         ii->i_bh = NULL;
 165         ii->i_state = 0;
 166         ii->i_cno = 0;
 167         ii->vfs_inode.i_version = 1;
 168         nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
 169         return &ii->vfs_inode;
 170 }
 171
 172 static void nilfs_i_callback(struct rcu_head *head)
 173 {
 174         struct inode *inode = container_of(head, struct inode, i_rcu);
 175         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 176
 177         INIT_LIST_HEAD(&inode->i_dentry);
 178
 179         if (mdi) {
 180                 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 181                 kfree(mdi);
 182         }
 183         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 184 }
 185
 186 void nilfs_destroy_inode(struct inode *inode)
 187 {
 188         call_rcu(&inode->i_rcu, nilfs_i_callback);
 189 }
 190
 191 static int nilfs_sync_super(struct super_block *sb, int flag)
 192 {
 193         struct the_nilfs *nilfs = sb->s_fs_info;
 194         int err;
 195
 196  retry:
 197         set_buffer_dirty(nilfs->ns_sbh[0]);
 198         if (nilfs_test_opt(nilfs, BARRIER)) {
 199                 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 200                                           WRITE_SYNC | WRITE_FLUSH_FUA);
 201         } else {
 202                 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 203         }
 204
 205         if (unlikely(err)) {
 206                 printk(KERN_ERR
 207                        "NILFS: unable to write superblock (err=%d)\n", err);
 208                 if (err == -EIO && nilfs->ns_sbh[1]) {
 209                         /*
 210                          * sbp[0] points to newer log than sbp[1],
 211                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 212                          */
 213                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 214                                nilfs->ns_sbsize);
 215                         nilfs_fall_back_super_block(nilfs);
 216                         goto retry;
 217                 }
 218         } else {
 219                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 220
 221                 nilfs->ns_sbwcount++;
 222
 223                 /*
 224                  * The latest segment becomes trailable from the position
 225                  * written in superblock.
 226                  */
 227                 clear_nilfs_discontinued(nilfs);
 228
 229                 /* update GC protection for recent segments */
 230                 if (nilfs->ns_sbh[1]) {
 231                         if (flag == NILFS_SB_COMMIT_ALL) {
 232                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 233                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 234                                         goto out;
 235                         }
 236                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 237                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 238                                 sbp = nilfs->ns_sbp[1];
 239                 }
 240
 241                 spin_lock(&nilfs->ns_last_segment_lock);
 242                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 243                 spin_unlock(&nilfs->ns_last_segment_lock);
 244         }
 245  out:
 246         return err;
 247 }
 248
 249 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 250                           struct the_nilfs *nilfs)
 251 {
 252         sector_t nfreeblocks;
 253
 254         /* nilfs->ns_sem must be locked by the caller. */
 255         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 256         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 257
 258         spin_lock(&nilfs->ns_last_segment_lock);
 259         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 260         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 261         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 262         spin_unlock(&nilfs->ns_last_segment_lock);
 263 }
 264
 265 struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
 266                                                int flip)
 267 {
 268         struct the_nilfs *nilfs = sb->s_fs_info;
 269         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 270
 271         /* nilfs->ns_sem must be locked by the caller. */
 272         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 273                 if (sbp[1] &&
 274                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 275                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 276                 } else {
 277                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 278                                sb->s_id);
 279                         return NULL;
 280                 }
 281         } else if (sbp[1] &&
 282                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 283                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 284         }
 285
 286         if (flip && sbp[1])
 287                 nilfs_swap_super_block(nilfs);
 288
 289         return sbp;
 290 }
 291
 292 int nilfs_commit_super(struct super_block *sb, int flag)
 293 {
 294         struct the_nilfs *nilfs = sb->s_fs_info;
 295         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 296         time_t t;
 297
 298         /* nilfs->ns_sem must be locked by the caller. */
 299         t = get_seconds();
 300         nilfs->ns_sbwtime = t;
 301         sbp[0]->s_wtime = cpu_to_le64(t);
 302         sbp[0]->s_sum = 0;
 303         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 304                                              (unsigned char *)sbp[0],
 305                                              nilfs->ns_sbsize));
 306         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 307                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 308                 sbp[1]->s_sum = 0;
 309                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 310                                             (unsigned char *)sbp[1],
 311                                             nilfs->ns_sbsize));
 312         }
 313         clear_nilfs_sb_dirty(nilfs);
 314         return nilfs_sync_super(sb, flag);
 315 }
 316
 317 /**
 318  * nilfs_cleanup_super() - write filesystem state for cleanup
 319  * @sb: super block instance to be unmounted or degraded to read-only
 320  *
 321  * This function restores state flags in the on-disk super block.
 322  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 323  * filesystem was not clean previously.
 324  */
 325 int nilfs_cleanup_super(struct super_block *sb)
 326 {
 327         struct the_nilfs *nilfs = sb->s_fs_info;
 328         struct nilfs_super_block **sbp;
 329         int flag = NILFS_SB_COMMIT;
 330         int ret = -EIO;
 331
 332         sbp = nilfs_prepare_super(sb, 0);
 333         if (sbp) {
 334                 sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
 335                 nilfs_set_log_cursor(sbp[0], nilfs);
 336                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 337                         /*
 338                          * make the "clean" flag also to the opposite
 339                          * super block if both super blocks point to
 340                          * the same checkpoint.
 341                          */
 342                         sbp[1]->s_state = sbp[0]->s_state;
 343                         flag = NILFS_SB_COMMIT_ALL;
 344                 }
 345                 ret = nilfs_commit_super(sb, flag);
 346         }
 347         return ret;
 348 }
 349
 350 static void nilfs_put_super(struct super_block *sb)
 351 {
 352         struct the_nilfs *nilfs = sb->s_fs_info;
 353
 354         nilfs_detach_log_writer(sb);
 355
 356         if (!(sb->s_flags & MS_RDONLY)) {
 357                 down_write(&nilfs->ns_sem);
 358                 nilfs_cleanup_super(sb);
 359                 up_write(&nilfs->ns_sem);
 360         }
 361
 362         iput(nilfs->ns_sufile);
 363         iput(nilfs->ns_cpfile);
 364         iput(nilfs->ns_dat);
 365
 366         destroy_nilfs(nilfs);
 367         sb->s_fs_info = NULL;
 368 }
 369
 370 static int nilfs_sync_fs(struct super_block *sb, int wait)
 371 {
 372         struct the_nilfs *nilfs = sb->s_fs_info;
 373         struct nilfs_super_block **sbp;
 374         int err = 0;
 375
 376         /* This function is called when super block should be written back */
 377         if (wait)
 378                 err = nilfs_construct_segment(sb);
 379
 380         down_write(&nilfs->ns_sem);
 381         if (nilfs_sb_dirty(nilfs)) {
 382                 sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
 383                 if (likely(sbp)) {
 384                         nilfs_set_log_cursor(sbp[0], nilfs);
 385                         nilfs_commit_super(sb, NILFS_SB_COMMIT);
 386                 }
 387         }
 388         up_write(&nilfs->ns_sem);
 389
 390         return err;
 391 }
 392
 393 int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
 394                             struct nilfs_root **rootp)
 395 {
 396         struct the_nilfs *nilfs = sb->s_fs_info;
 397         struct nilfs_root *root;
 398         struct nilfs_checkpoint *raw_cp;
 399         struct buffer_head *bh_cp;
 400         int err = -ENOMEM;
 401
 402         root = nilfs_find_or_create_root(
 403                 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
 404         if (!root)
 405                 return err;
 406
 407         if (root->ifile)
 408                 goto reuse; /* already attached checkpoint */
 409
 410         down_read(&nilfs->ns_segctor_sem);
 411         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 412                                           &bh_cp);
 413         up_read(&nilfs->ns_segctor_sem);
 414         if (unlikely(err)) {
 415                 if (err == -ENOENT || err == -EINVAL) {
 416                         printk(KERN_ERR
 417                                "NILFS: Invalid checkpoint "
 418                                "(checkpoint number=%llu)\n",
 419                                (unsigned long long)cno);
 420                         err = -EINVAL;
 421                 }
 422                 goto failed;
 423         }
 424
 425         err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
 426                                &raw_cp->cp_ifile_inode, &root->ifile);
 427         if (err)
 428                 goto failed_bh;
 429
 430         atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 431         atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 432
 433         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 434
 435  reuse:
 436         *rootp = root;
 437         return 0;
 438
 439  failed_bh:
 440         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 441  failed:
 442         nilfs_put_root(root);
 443
 444         return err;
 445 }
 446
 447 static int nilfs_freeze(struct super_block *sb)
 448 {
 449         struct the_nilfs *nilfs = sb->s_fs_info;
 450         int err;
 451
 452         if (sb->s_flags & MS_RDONLY)
 453                 return 0;
 454
 455         /* Mark super block clean */
 456         down_write(&nilfs->ns_sem);
 457         err = nilfs_cleanup_super(sb);
 458         up_write(&nilfs->ns_sem);
 459         return err;
 460 }
 461
 462 static int nilfs_unfreeze(struct super_block *sb)
 463 {
 464         struct the_nilfs *nilfs = sb->s_fs_info;
 465
 466         if (sb->s_flags & MS_RDONLY)
 467                 return 0;
 468
 469         down_write(&nilfs->ns_sem);
 470         nilfs_setup_super(sb, false);
 471         up_write(&nilfs->ns_sem);
 472         return 0;
 473 }
 474
 475 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 476 {
 477         struct super_block *sb = dentry->d_sb;
 478         struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
 479         struct the_nilfs *nilfs = root->nilfs;
 480         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 481         unsigned long long blocks;
 482         unsigned long overhead;
 483         unsigned long nrsvblocks;
 484         sector_t nfreeblocks;
 485         int err;
 486
 487         /*
 488          * Compute all of the segment blocks
 489          *
 490          * The blocks before first segment and after last segment
 491          * are excluded.
 492          */
 493         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 494                 - nilfs->ns_first_data_block;
 495         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 496
 497         /*
 498          * Compute the overhead
 499          *
 500          * When distributing meta data blocks outside segment structure,
 501          * We must count them as the overhead.
 502          */
 503         overhead = 0;
 504
 505         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 506         if (unlikely(err))
 507                 return err;
 508
 509         buf->f_type = NILFS_SUPER_MAGIC;
 510         buf->f_bsize = sb->s_blocksize;
 511         buf->f_blocks = blocks - overhead;
 512         buf->f_bfree = nfreeblocks;
 513         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 514                 (buf->f_bfree - nrsvblocks) : 0;
 515         buf->f_files = atomic_read(&root->inodes_count);
 516         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 517         buf->f_namelen = NILFS_NAME_LEN;
 518         buf->f_fsid.val[0] = (u32)id;
 519         buf->f_fsid.val[1] = (u32)(id >> 32);
 520
 521         return 0;
 522 }
 523
 524 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 525 {
 526         struct super_block *sb = vfs->mnt_sb;
 527         struct the_nilfs *nilfs = sb->s_fs_info;
 528         struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
 529
 530         if (!nilfs_test_opt(nilfs, BARRIER))
 531                 seq_puts(seq, ",nobarrier");
 532         if (root->cno != NILFS_CPTREE_CURRENT_CNO)
 533                 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
 534         if (nilfs_test_opt(nilfs, ERRORS_PANIC))
 535                 seq_puts(seq, ",errors=panic");
 536         if (nilfs_test_opt(nilfs, ERRORS_CONT))
 537                 seq_puts(seq, ",errors=continue");
 538         if (nilfs_test_opt(nilfs, STRICT_ORDER))
 539                 seq_puts(seq, ",order=strict");
 540         if (nilfs_test_opt(nilfs, NORECOVERY))
 541                 seq_puts(seq, ",norecovery");
 542         if (nilfs_test_opt(nilfs, DISCARD))
 543                 seq_puts(seq, ",discard");
 544
 545         return 0;
 546 }
 547
 548 static const struct super_operations nilfs_sops = {
 549         .alloc_inode    = nilfs_alloc_inode,
 550         .destroy_inode  = nilfs_destroy_inode,
 551         .dirty_inode    = nilfs_dirty_inode,
 552         /* .write_inode    = nilfs_write_inode, */
 553         /* .put_inode      = nilfs_put_inode, */
 554         /* .drop_inode    = nilfs_drop_inode, */
 555         .evict_inode    = nilfs_evict_inode,
 556         .put_super      = nilfs_put_super,
 557         /* .write_super    = nilfs_write_super, */
 558         .sync_fs        = nilfs_sync_fs,
 559         .freeze_fs      = nilfs_freeze,
 560         .unfreeze_fs    = nilfs_unfreeze,
 561         /* .write_super_lockfs */
 562         /* .unlockfs */
 563         .statfs         = nilfs_statfs,
 564         .remount_fs     = nilfs_remount,
 565         /* .umount_begin */
 566         .show_options = nilfs_show_options
 567 };
 568
 569 enum {
 570         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 571         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 572         Opt_discard, Opt_nodiscard, Opt_err,
 573 };
 574
 575 static match_table_t tokens = {
 576         {Opt_err_cont, "errors=continue"},
 577         {Opt_err_panic, "errors=panic"},
 578         {Opt_err_ro, "errors=remount-ro"},
 579         {Opt_barrier, "barrier"},
 580         {Opt_nobarrier, "nobarrier"},
 581         {Opt_snapshot, "cp=%u"},
 582         {Opt_order, "order=%s"},
 583         {Opt_norecovery, "norecovery"},
 584         {Opt_discard, "discard"},
 585         {Opt_nodiscard, "nodiscard"},
 586         {Opt_err, NULL}
 587 };
 588
 589 static int parse_options(char *options, struct super_block *sb, int is_remount)
 590 {
 591         struct the_nilfs *nilfs = sb->s_fs_info;
 592         char *p;
 593         substring_t args[MAX_OPT_ARGS];
 594
 595         if (!options)
 596                 return 1;
 597
 598         while ((p = strsep(&options, ",")) != NULL) {
 599                 int token;
 600                 if (!*p)
 601                         continue;
 602
 603                 token = match_token(p, tokens, args);
 604                 switch (token) {
 605                 case Opt_barrier:
 606                         nilfs_set_opt(nilfs, BARRIER);
 607                         break;
 608                 case Opt_nobarrier:
 609                         nilfs_clear_opt(nilfs, BARRIER);
 610                         break;
 611                 case Opt_order:
 612                         if (strcmp(args[0].from, "relaxed") == 0)
 613                                 /* Ordered data semantics */
 614                                 nilfs_clear_opt(nilfs, STRICT_ORDER);
 615                         else if (strcmp(args[0].from, "strict") == 0)
 616                                 /* Strict in-order semantics */
 617                                 nilfs_set_opt(nilfs, STRICT_ORDER);
 618                         else
 619                                 return 0;
 620                         break;
 621                 case Opt_err_panic:
 622                         nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
 623                         break;
 624                 case Opt_err_ro:
 625                         nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
 626                         break;
 627                 case Opt_err_cont:
 628                         nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
 629                         break;
 630                 case Opt_snapshot:
 631                         if (is_remount) {
 632                                 printk(KERN_ERR
 633                                        "NILFS: \"%s\" option is invalid "
 634                                        "for remount.\n", p);
 635                                 return 0;
 636                         }
 637                         break;
 638                 case Opt_norecovery:
 639                         nilfs_set_opt(nilfs, NORECOVERY);
 640                         break;
 641                 case Opt_discard:
 642                         nilfs_set_opt(nilfs, DISCARD);
 643                         break;
 644                 case Opt_nodiscard:
 645                         nilfs_clear_opt(nilfs, DISCARD);
 646                         break;
 647                 default:
 648                         printk(KERN_ERR
 649                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 650                         return 0;
 651                 }
 652         }
 653         return 1;
 654 }
 655
 656 static inline void
 657 nilfs_set_default_options(struct super_block *sb,
 658                           struct nilfs_super_block *sbp)
 659 {
 660         struct the_nilfs *nilfs = sb->s_fs_info;
 661
 662         nilfs->ns_mount_opt =
 663                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 664 }
 665
 666 static int nilfs_setup_super(struct super_block *sb, int is_mount)
 667 {
 668         struct the_nilfs *nilfs = sb->s_fs_info;
 669         struct nilfs_super_block **sbp;
 670         int max_mnt_count;
 671         int mnt_count;
 672
 673         /* nilfs->ns_sem must be locked by the caller. */
 674         sbp = nilfs_prepare_super(sb, 0);
 675         if (!sbp)
 676                 return -EIO;
 677
 678         if (!is_mount)
 679                 goto skip_mount_setup;
 680
 681         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 682         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 683
 684         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 685                 printk(KERN_WARNING
 686                        "NILFS warning: mounting fs with errors\n");
 687 #if 0
 688         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 689                 printk(KERN_WARNING
 690                        "NILFS warning: maximal mount count reached\n");
 691 #endif
 692         }
 693         if (!max_mnt_count)
 694                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 695
 696         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 697         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 698
 699 skip_mount_setup:
 700         sbp[0]->s_state =
 701                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 702         /* synchronize sbp[1] with sbp[0] */
 703         if (sbp[1])
 704                 memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 705         return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
 706 }
 707
 708 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 709                                                  u64 pos, int blocksize,
 710                                                  struct buffer_head **pbh)
 711 {
 712         unsigned long long sb_index = pos;
 713         unsigned long offset;
 714
 715         offset = do_div(sb_index, blocksize);
 716         *pbh = sb_bread(sb, sb_index);
 717         if (!*pbh)
 718                 return NULL;
 719         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 720 }
 721
 722 int nilfs_store_magic_and_option(struct super_block *sb,
 723                                  struct nilfs_super_block *sbp,
 724                                  char *data)
 725 {
 726         struct the_nilfs *nilfs = sb->s_fs_info;
 727
 728         sb->s_magic = le16_to_cpu(sbp->s_magic);
 729
 730         /* FS independent flags */
 731 #ifdef NILFS_ATIME_DISABLE
 732         sb->s_flags |= MS_NOATIME;
 733 #endif
 734
 735         nilfs_set_default_options(sb, sbp);
 736
 737         nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
 738         nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
 739         nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
 740         nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
 741
 742         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 743 }
 744
 745 int nilfs_check_feature_compatibility(struct super_block *sb,
 746                                       struct nilfs_super_block *sbp)
 747 {
 748         __u64 features;
 749
 750         features = le64_to_cpu(sbp->s_feature_incompat) &
 751                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 752         if (features) {
 753                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 754                        "optional features (%llx)\n",
 755                        (unsigned long long)features);
 756                 return -EINVAL;
 757         }
 758         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 759                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 760         if (!(sb->s_flags & MS_RDONLY) && features) {
 761                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 762                        "unsupported optional features (%llx)\n",
 763                        (unsigned long long)features);
 764                 return -EINVAL;
 765         }
 766         return 0;
 767 }
 768
 769 static int nilfs_get_root_dentry(struct super_block *sb,
 770                                  struct nilfs_root *root,
 771                                  struct dentry **root_dentry)
 772 {
 773         struct inode *inode;
 774         struct dentry *dentry;
 775         int ret = 0;
 776
 777         inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
 778         if (IS_ERR(inode)) {
 779                 printk(KERN_ERR "NILFS: get root inode failed\n");
 780                 ret = PTR_ERR(inode);
 781                 goto out;
 782         }
 783         if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
 784                 iput(inode);
 785                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 786                 ret = -EINVAL;
 787                 goto out;
 788         }
 789
 790         if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
 791                 dentry = d_find_alias(inode);
 792                 if (!dentry) {
 793                         dentry = d_alloc_root(inode);
 794                         if (!dentry) {
 795                                 iput(inode);
 796                                 ret = -ENOMEM;
 797                                 goto failed_dentry;
 798                         }
 799                 } else {
 800                         iput(inode);
 801                 }
 802         } else {
 803                 dentry = d_obtain_alias(inode);
 804                 if (IS_ERR(dentry)) {
 805                         ret = PTR_ERR(dentry);
 806                         goto failed_dentry;
 807                 }
 808         }
 809         *root_dentry = dentry;
 810  out:
 811         return ret;
 812
 813  failed_dentry:
 814         printk(KERN_ERR "NILFS: get root dentry failed\n");
 815         goto out;
 816 }
 817
 818 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 819                                  struct dentry **root_dentry)
 820 {
 821         struct the_nilfs *nilfs = s->s_fs_info;
 822         struct nilfs_root *root;
 823         int ret;
 824
 825         down_read(&nilfs->ns_segctor_sem);
 826         ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
 827         up_read(&nilfs->ns_segctor_sem);
 828         if (ret < 0) {
 829                 ret = (ret == -ENOENT) ? -EINVAL : ret;
 830                 goto out;
 831         } else if (!ret) {
 832                 printk(KERN_ERR "NILFS: The specified checkpoint is "
 833                        "not a snapshot (checkpoint number=%llu).\n",
 834                        (unsigned long long)cno);
 835                 ret = -EINVAL;
 836                 goto out;
 837         }
 838
 839         ret = nilfs_attach_checkpoint(s, cno, false, &root);
 840         if (ret) {
 841                 printk(KERN_ERR "NILFS: error loading snapshot "
 842                        "(checkpoint number=%llu).\n",
 843                (unsigned long long)cno);
 844                 goto out;
 845         }
 846         ret = nilfs_get_root_dentry(s, root, root_dentry);
 847         nilfs_put_root(root);
 848  out:
 849         return ret;
 850 }
 851
 852 static int nilfs_tree_was_touched(struct dentry *root_dentry)
 853 {
 854         return root_dentry->d_count > 1;
 855 }
 856
 857 /**
 858  * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
 859  * @root_dentry: root dentry of the tree to be shrunk
 860  *
 861  * This function returns true if the tree was in-use.
 862  */
 863 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
 864 {
 865         if (have_submounts(root_dentry))
 866                 return true;
 867         shrink_dcache_parent(root_dentry);
 868         return nilfs_tree_was_touched(root_dentry);
 869 }
 870
 871 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
 872 {
 873         struct the_nilfs *nilfs = sb->s_fs_info;
 874         struct nilfs_root *root;
 875         struct inode *inode;
 876         struct dentry *dentry;
 877         int ret;
 878
 879         if (cno < 0 || cno > nilfs->ns_cno)
 880                 return false;
 881
 882         if (cno >= nilfs_last_cno(nilfs))
 883                 return true;    /* protect recent checkpoints */
 884
 885         ret = false;
 886         root = nilfs_lookup_root(nilfs, cno);
 887         if (root) {
 888                 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
 889                 if (inode) {
 890                         dentry = d_find_alias(inode);
 891                         if (dentry) {
 892                                 if (nilfs_tree_was_touched(dentry))
 893                                         ret = nilfs_try_to_shrink_tree(dentry);
 894                                 dput(dentry);
 895                         }
 896                         iput(inode);
 897                 }
 898                 nilfs_put_root(root);
 899         }
 900         return ret;
 901 }
 902
 903 /**
 904  * nilfs_fill_super() - initialize a super block instance
 905  * @sb: super_block
 906  * @data: mount options
 907  * @silent: silent mode flag
 908  *
 909  * This function is called exclusively by nilfs->ns_mount_mutex.
 910  * So, the recovery process is protected from other simultaneous mounts.
 911  */
 912 static int
 913 nilfs_fill_super(struct super_block *sb, void *data, int silent)
 914 {
 915         struct the_nilfs *nilfs;
 916         struct nilfs_root *fsroot;
 917         struct backing_dev_info *bdi;
 918         __u64 cno;
 919         int err;
 920
 921         nilfs = alloc_nilfs(sb->s_bdev);
 922         if (!nilfs)
 923                 return -ENOMEM;
 924
 925         sb->s_fs_info = nilfs;
 926
 927         err = init_nilfs(nilfs, sb, (char *)data);
 928         if (err)
 929                 goto failed_nilfs;
 930
 931         sb->s_op = &nilfs_sops;
 932         sb->s_export_op = &nilfs_export_ops;
 933         sb->s_root = NULL;
 934         sb->s_time_gran = 1;
 935
 936         bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 937         sb->s_bdi = bdi ? : &default_backing_dev_info;
 938
 939         err = load_nilfs(nilfs, sb);
 940         if (err)
 941                 goto failed_nilfs;
 942
 943         cno = nilfs_last_cno(nilfs);
 944         err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
 945         if (err) {
 946                 printk(KERN_ERR "NILFS: error loading last checkpoint "
 947                        "(checkpoint number=%llu).\n", (unsigned long long)cno);
 948                 goto failed_unload;
 949         }
 950
 951         if (!(sb->s_flags & MS_RDONLY)) {
 952                 err = nilfs_attach_log_writer(sb, fsroot);
 953                 if (err)
 954                         goto failed_checkpoint;
 955         }
 956
 957         err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
 958         if (err)
 959                 goto failed_segctor;
 960
 961         nilfs_put_root(fsroot);
 962
 963         if (!(sb->s_flags & MS_RDONLY)) {
 964                 down_write(&nilfs->ns_sem);
 965                 nilfs_setup_super(sb, true);
 966                 up_write(&nilfs->ns_sem);
 967         }
 968
 969         return 0;
 970
 971  failed_segctor:
 972         nilfs_detach_log_writer(sb);
 973
 974  failed_checkpoint:
 975         nilfs_put_root(fsroot);
 976
 977  failed_unload:
 978         iput(nilfs->ns_sufile);
 979         iput(nilfs->ns_cpfile);
 980         iput(nilfs->ns_dat);
 981
 982  failed_nilfs:
 983         destroy_nilfs(nilfs);
 984         return err;
 985 }
 986
 987 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 988 {
 989         struct the_nilfs *nilfs = sb->s_fs_info;
 990         unsigned long old_sb_flags;
 991         unsigned long old_mount_opt;
 992         int err;
 993
 994         old_sb_flags = sb->s_flags;
 995         old_mount_opt = nilfs->ns_mount_opt;
 996
 997         if (!parse_options(data, sb, 1)) {
 998                 err = -EINVAL;
 999                 goto restore_opts;
1000         }
1001         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
1002
1003         err = -EINVAL;
1004
1005         if (!nilfs_valid_fs(nilfs)) {
1006                 printk(KERN_WARNING "NILFS (device %s): couldn't "
1007                        "remount because the filesystem is in an "
1008                        "incomplete recovery state.\n", sb->s_id);
1009                 goto restore_opts;
1010         }
1011
1012         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1013                 goto out;
1014         if (*flags & MS_RDONLY) {
1015                 /* Shutting down log writer */
1016                 nilfs_detach_log_writer(sb);
1017                 sb->s_flags |= MS_RDONLY;
1018
1019                 /*
1020                  * Remounting a valid RW partition RDONLY, so set
1021                  * the RDONLY flag and then mark the partition as valid again.
1022                  */
1023                 down_write(&nilfs->ns_sem);
1024                 nilfs_cleanup_super(sb);
1025                 up_write(&nilfs->ns_sem);
1026         } else {
1027                 __u64 features;
1028                 struct nilfs_root *root;
1029
1030                 /*
1031                  * Mounting a RDONLY partition read-write, so reread and
1032                  * store the current valid flag.  (It may have been changed
1033                  * by fsck since we originally mounted the partition.)
1034                  */
1035                 down_read(&nilfs->ns_sem);
1036                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1037                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
1038                 up_read(&nilfs->ns_sem);
1039                 if (features) {
1040                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1041                                "remount RDWR because of unsupported optional "
1042                                "features (%llx)\n",
1043                                sb->s_id, (unsigned long long)features);
1044                         err = -EROFS;
1045                         goto restore_opts;
1046                 }
1047
1048                 sb->s_flags &= ~MS_RDONLY;
1049
1050                 root = NILFS_I(sb->s_root->d_inode)->i_root;
1051                 err = nilfs_attach_log_writer(sb, root);
1052                 if (err)
1053                         goto restore_opts;
1054
1055                 down_write(&nilfs->ns_sem);
1056                 nilfs_setup_super(sb, true);
1057                 up_write(&nilfs->ns_sem);
1058         }
1059  out:
1060         return 0;
1061
1062  restore_opts:
1063         sb->s_flags = old_sb_flags;
1064         nilfs->ns_mount_opt = old_mount_opt;
1065         return err;
1066 }
1067
1068 struct nilfs_super_data {
1069         struct block_device *bdev;
1070         __u64 cno;
1071         int flags;
1072 };
1073
1074 /**
1075  * nilfs_identify - pre-read mount options needed to identify mount instance
1076  * @data: mount options
1077  * @sd: nilfs_super_data
1078  */
1079 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1080 {
1081         char *p, *options = data;
1082         substring_t args[MAX_OPT_ARGS];
1083         int token;
1084         int ret = 0;
1085
1086         do {
1087                 p = strsep(&options, ",");
1088                 if (p != NULL && *p) {
1089                         token = match_token(p, tokens, args);
1090                         if (token == Opt_snapshot) {
1091                                 if (!(sd->flags & MS_RDONLY)) {
1092                                         ret++;
1093                                 } else {
1094                                         sd->cno = simple_strtoull(args[0].from,
1095                                                                   NULL, 0);
1096                                         /*
1097                                          * No need to see the end pointer;
1098                                          * match_token() has done syntax
1099                                          * checking.
1100                                          */
1101                                         if (sd->cno == 0)
1102                                                 ret++;
1103                                 }
1104                         }
1105                         if (ret)
1106                                 printk(KERN_ERR
1107                                        "NILFS: invalid mount option: %s\n", p);
1108                 }
1109                 if (!options)
1110                         break;
1111                 BUG_ON(options == data);
1112                 *(options - 1) = ',';
1113         } while (!ret);
1114         return ret;
1115 }
1116
1117 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1118 {
1119         s->s_bdev = data;
1120         s->s_dev = s->s_bdev->bd_dev;
1121         return 0;
1122 }
1123
1124 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1125 {
1126         return (void *)s->s_bdev == data;
1127 }
1128
1129 static struct dentry *
1130 nilfs_mount(struct file_system_type *fs_type, int flags,
1131              const char *dev_name, void *data)
1132 {
1133         struct nilfs_super_data sd;
1134         struct super_block *s;
1135         fmode_t mode = FMODE_READ | FMODE_EXCL;
1136         struct dentry *root_dentry;
1137         int err, s_new = false;
1138
1139         if (!(flags & MS_RDONLY))
1140                 mode |= FMODE_WRITE;
1141
1142         sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1143         if (IS_ERR(sd.bdev))
1144                 return ERR_CAST(sd.bdev);
1145
1146         sd.cno = 0;
1147         sd.flags = flags;
1148         if (nilfs_identify((char *)data, &sd)) {
1149                 err = -EINVAL;
1150                 goto failed;
1151         }
1152
1153         /*
1154          * once the super is inserted into the list by sget, s_umount
1155          * will protect the lockfs code from trying to start a snapshot
1156          * while we are mounting
1157          */
1158         mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1159         if (sd.bdev->bd_fsfreeze_count > 0) {
1160                 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1161                 err = -EBUSY;
1162                 goto failed;
1163         }
1164         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1165         mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1166         if (IS_ERR(s)) {
1167                 err = PTR_ERR(s);
1168                 goto failed;
1169         }
1170
1171         if (!s->s_root) {
1172                 char b[BDEVNAME_SIZE];
1173
1174                 s_new = true;
1175
1176                 /* New superblock instance created */
1177                 s->s_flags = flags;
1178                 s->s_mode = mode;
1179                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1180                 sb_set_blocksize(s, block_size(sd.bdev));
1181
1182                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1183                 if (err)
1184                         goto failed_super;
1185
1186                 s->s_flags |= MS_ACTIVE;
1187         } else if (!sd.cno) {
1188                 int busy = false;
1189
1190                 if (nilfs_tree_was_touched(s->s_root)) {
1191                         busy = nilfs_try_to_shrink_tree(s->s_root);
1192                         if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1193                                 printk(KERN_ERR "NILFS: the device already "
1194                                        "has a %s mount.\n",
1195                                        (s->s_flags & MS_RDONLY) ?
1196                                        "read-only" : "read/write");
1197                                 err = -EBUSY;
1198                                 goto failed_super;
1199                         }
1200                 }
1201                 if (!busy) {
1202                         /*
1203                          * Try remount to setup mount states if the current
1204                          * tree is not mounted and only snapshots use this sb.
1205                          */
1206                         err = nilfs_remount(s, &flags, data);
1207                         if (err)
1208                                 goto failed_super;
1209                 }
1210         }
1211
1212         if (sd.cno) {
1213                 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1214                 if (err)
1215                         goto failed_super;
1216         } else {
1217                 root_dentry = dget(s->s_root);
1218         }
1219
1220         if (!s_new)
1221                 blkdev_put(sd.bdev, mode);
1222
1223         return root_dentry;
1224
1225  failed_super:
1226         deactivate_locked_super(s);
1227
1228  failed:
1229         if (!s_new)
1230                 blkdev_put(sd.bdev, mode);
1231         return ERR_PTR(err);
1232 }
1233
1234 struct file_system_type nilfs_fs_type = {
1235         .owner    = THIS_MODULE,
1236         .name     = "nilfs2",
1237         .mount    = nilfs_mount,
1238         .kill_sb  = kill_block_super,
1239         .fs_flags = FS_REQUIRES_DEV,
1240 };
1241
1242 static void nilfs_inode_init_once(void *obj)
1243 {
1244         struct nilfs_inode_info *ii = obj;
1245
1246         INIT_LIST_HEAD(&ii->i_dirty);
1247 #ifdef CONFIG_NILFS_XATTR
1248         init_rwsem(&ii->xattr_sem);
1249 #endif
1250         address_space_init_once(&ii->i_btnode_cache);
1251         ii->i_bmap = &ii->i_bmap_data;
1252         inode_init_once(&ii->vfs_inode);
1253 }
1254
1255 static void nilfs_segbuf_init_once(void *obj)
1256 {
1257         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1258 }
1259
1260 static void nilfs_destroy_cachep(void)
1261 {
1262         if (nilfs_inode_cachep)
1263                 kmem_cache_destroy(nilfs_inode_cachep);
1264         if (nilfs_transaction_cachep)
1265                 kmem_cache_destroy(nilfs_transaction_cachep);
1266         if (nilfs_segbuf_cachep)
1267                 kmem_cache_destroy(nilfs_segbuf_cachep);
1268         if (nilfs_btree_path_cache)
1269                 kmem_cache_destroy(nilfs_btree_path_cache);
1270 }
1271
1272 static int __init nilfs_init_cachep(void)
1273 {
1274         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1275                         sizeof(struct nilfs_inode_info), 0,
1276                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1277         if (!nilfs_inode_cachep)
1278                 goto fail;
1279
1280         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1281                         sizeof(struct nilfs_transaction_info), 0,
1282                         SLAB_RECLAIM_ACCOUNT, NULL);
1283         if (!nilfs_transaction_cachep)
1284                 goto fail;
1285
1286         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1287                         sizeof(struct nilfs_segment_buffer), 0,
1288                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1289         if (!nilfs_segbuf_cachep)
1290                 goto fail;
1291
1292         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1293                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1294                         0, 0, NULL);
1295         if (!nilfs_btree_path_cache)
1296                 goto fail;
1297
1298         return 0;
1299
1300 fail:
1301         nilfs_destroy_cachep();
1302         return -ENOMEM;
1303 }
1304
1305 static int __init init_nilfs_fs(void)
1306 {
1307         int err;
1308
1309         err = nilfs_init_cachep();
1310         if (err)
1311                 goto fail;
1312
1313         err = register_filesystem(&nilfs_fs_type);
1314         if (err)
1315                 goto free_cachep;
1316
1317         printk(KERN_INFO "NILFS version 2 loaded\n");
1318         return 0;
1319
1320 free_cachep:
1321         nilfs_destroy_cachep();
1322 fail:
1323         return err;
1324 }
1325
1326 static void __exit exit_nilfs_fs(void)
1327 {
1328         nilfs_destroy_cachep();
1329         unregister_filesystem(&nilfs_fs_type);
1330 }
1331
1332 module_init(init_nilfs_fs)
1333 module_exit(exit_nilfs_fs)