fs/nilfs2/super.c

   1 /*
   2  * super.c - NILFS module and super block management.
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21  */
  22 /*
  23  *  linux/fs/ext2/super.c
  24  *
  25  * Copyright (C) 1992, 1993, 1994, 1995
  26  * Remy Card (card@masi.ibp.fr)
  27  * Laboratoire MASI - Institut Blaise Pascal
  28  * Universite Pierre et Marie Curie (Paris VI)
  29  *
  30  *  from
  31  *
  32  *  linux/fs/minix/inode.c
  33  *
  34  *  Copyright (C) 1991, 1992  Linus Torvalds
  35  *
  36  *  Big-endian to little-endian byte-swapping/bitmaps by
  37  *        David S. Miller (davem@caip.rutgers.edu), 1995
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/string.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/parser.h>
  46 #include <linux/random.h>
  47 #include <linux/crc32.h>
  48 #include <linux/vfs.h>
  49 #include <linux/writeback.h>
  50 #include <linux/kobject.h>
  51 #include <linux/seq_file.h>
  52 #include <linux/mount.h>
  53 #include "nilfs.h"
  54 #include "export.h"
  55 #include "mdt.h"
  56 #include "alloc.h"
  57 #include "btree.h"
  58 #include "btnode.h"
  59 #include "page.h"
  60 #include "cpfile.h"
  61 #include "ifile.h"
  62 #include "dat.h"
  63 #include "segment.h"
  64 #include "segbuf.h"
  65
  66 MODULE_AUTHOR("NTT Corp.");
  67 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  68                    "(NILFS)");
  69 MODULE_LICENSE("GPL");
  70
  71 struct kmem_cache *nilfs_inode_cachep;
  72 struct kmem_cache *nilfs_transaction_cachep;
  73 struct kmem_cache *nilfs_segbuf_cachep;
  74 struct kmem_cache *nilfs_btree_path_cache;
  75
  76 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  77
  78 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  79 {
  80         struct the_nilfs *nilfs = sbi->s_nilfs;
  81         struct nilfs_super_block **sbp;
  82
  83         down_write(&nilfs->ns_sem);
  84         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  85                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  86                 sbp = nilfs_prepare_super(sbi, 0);
  87                 if (likely(sbp)) {
  88                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  89                         if (sbp[1])
  90                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  91                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  92                 }
  93         }
  94         up_write(&nilfs->ns_sem);
  95 }
  96
  97 /**
  98  * nilfs_error() - report failure condition on a filesystem
  99  *
 100  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 101  * reporting an error message.  It should be called when NILFS detects
 102  * incoherences or defects of meta data on disk.  As for sustainable
 103  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 104  * function should be used instead.
 105  *
 106  * The segment constructor must not call this function because it can
 107  * kill itself.
 108  */
 109 void nilfs_error(struct super_block *sb, const char *function,
 110                  const char *fmt, ...)
 111 {
 112         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 113         va_list args;
 114
 115         va_start(args, fmt);
 116         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 117         vprintk(fmt, args);
 118         printk("\n");
 119         va_end(args);
 120
 121         if (!(sb->s_flags & MS_RDONLY)) {
 122                 nilfs_set_error(sbi);
 123
 124                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 125                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 126                         sb->s_flags |= MS_RDONLY;
 127                 }
 128         }
 129
 130         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 131                 panic("NILFS (device %s): panic forced after error\n",
 132                       sb->s_id);
 133 }
 134
 135 void nilfs_warning(struct super_block *sb, const char *function,
 136                    const char *fmt, ...)
 137 {
 138         va_list args;
 139
 140         va_start(args, fmt);
 141         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 142                sb->s_id, function);
 143         vprintk(fmt, args);
 144         printk("\n");
 145         va_end(args);
 146 }
 147
 148
 149 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 150 {
 151         struct nilfs_inode_info *ii;
 152
 153         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 154         if (!ii)
 155                 return NULL;
 156         ii->i_bh = NULL;
 157         ii->i_state = 0;
 158         ii->i_cno = 0;
 159         ii->vfs_inode.i_version = 1;
 160         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
 161         return &ii->vfs_inode;
 162 }
 163
 164 struct inode *nilfs_alloc_inode(struct super_block *sb)
 165 {
 166         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
 167 }
 168
 169 void nilfs_destroy_inode(struct inode *inode)
 170 {
 171         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 172
 173         if (mdi) {
 174                 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 175                 kfree(mdi);
 176         }
 177         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 178 }
 179
 180 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 181 {
 182         struct the_nilfs *nilfs = sbi->s_nilfs;
 183         int err;
 184
 185  retry:
 186         set_buffer_dirty(nilfs->ns_sbh[0]);
 187
 188         if (nilfs_test_opt(sbi, BARRIER)) {
 189                 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 190                                           WRITE_SYNC | WRITE_BARRIER);
 191                 if (err == -EOPNOTSUPP) {
 192                         nilfs_warning(sbi->s_super, __func__,
 193                                       "barrier-based sync failed. "
 194                                       "disabling barriers\n");
 195                         nilfs_clear_opt(sbi, BARRIER);
 196                         goto retry;
 197                 }
 198         } else {
 199                 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 200         }
 201
 202         if (unlikely(err)) {
 203                 printk(KERN_ERR
 204                        "NILFS: unable to write superblock (err=%d)\n", err);
 205                 if (err == -EIO && nilfs->ns_sbh[1]) {
 206                         /*
 207                          * sbp[0] points to newer log than sbp[1],
 208                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 209                          */
 210                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 211                                nilfs->ns_sbsize);
 212                         nilfs_fall_back_super_block(nilfs);
 213                         goto retry;
 214                 }
 215         } else {
 216                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 217
 218                 nilfs->ns_sbwcount++;
 219
 220                 /*
 221                  * The latest segment becomes trailable from the position
 222                  * written in superblock.
 223                  */
 224                 clear_nilfs_discontinued(nilfs);
 225
 226                 /* update GC protection for recent segments */
 227                 if (nilfs->ns_sbh[1]) {
 228                         if (flag == NILFS_SB_COMMIT_ALL) {
 229                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 230                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 231                                         goto out;
 232                         }
 233                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 234                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 235                                 sbp = nilfs->ns_sbp[1];
 236                 }
 237
 238                 spin_lock(&nilfs->ns_last_segment_lock);
 239                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 240                 spin_unlock(&nilfs->ns_last_segment_lock);
 241         }
 242  out:
 243         return err;
 244 }
 245
 246 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 247                           struct the_nilfs *nilfs)
 248 {
 249         sector_t nfreeblocks;
 250
 251         /* nilfs->ns_sem must be locked by the caller. */
 252         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 253         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 254
 255         spin_lock(&nilfs->ns_last_segment_lock);
 256         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 257         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 258         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 259         spin_unlock(&nilfs->ns_last_segment_lock);
 260 }
 261
 262 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 263                                                int flip)
 264 {
 265         struct the_nilfs *nilfs = sbi->s_nilfs;
 266         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 267
 268         /* nilfs->ns_sem must be locked by the caller. */
 269         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 270                 if (sbp[1] &&
 271                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 272                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 273                 } else {
 274                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 275                                sbi->s_super->s_id);
 276                         return NULL;
 277                 }
 278         } else if (sbp[1] &&
 279                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 280                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 281         }
 282
 283         if (flip && sbp[1])
 284                 nilfs_swap_super_block(nilfs);
 285
 286         return sbp;
 287 }
 288
 289 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 290 {
 291         struct the_nilfs *nilfs = sbi->s_nilfs;
 292         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 293         time_t t;
 294
 295         /* nilfs->ns_sem must be locked by the caller. */
 296         t = get_seconds();
 297         nilfs->ns_sbwtime = t;
 298         sbp[0]->s_wtime = cpu_to_le64(t);
 299         sbp[0]->s_sum = 0;
 300         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 301                                              (unsigned char *)sbp[0],
 302                                              nilfs->ns_sbsize));
 303         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 304                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 305                 sbp[1]->s_sum = 0;
 306                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 307                                             (unsigned char *)sbp[1],
 308                                             nilfs->ns_sbsize));
 309         }
 310         clear_nilfs_sb_dirty(nilfs);
 311         return nilfs_sync_super(sbi, flag);
 312 }
 313
 314 /**
 315  * nilfs_cleanup_super() - write filesystem state for cleanup
 316  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 317  *
 318  * This function restores state flags in the on-disk super block.
 319  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 320  * filesystem was not clean previously.
 321  */
 322 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 323 {
 324         struct nilfs_super_block **sbp;
 325         int flag = NILFS_SB_COMMIT;
 326         int ret = -EIO;
 327
 328         sbp = nilfs_prepare_super(sbi, 0);
 329         if (sbp) {
 330                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 331                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 332                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 333                         /*
 334                          * make the "clean" flag also to the opposite
 335                          * super block if both super blocks point to
 336                          * the same checkpoint.
 337                          */
 338                         sbp[1]->s_state = sbp[0]->s_state;
 339                         flag = NILFS_SB_COMMIT_ALL;
 340                 }
 341                 ret = nilfs_commit_super(sbi, flag);
 342         }
 343         return ret;
 344 }
 345
 346 static void nilfs_put_super(struct super_block *sb)
 347 {
 348         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 349         struct the_nilfs *nilfs = sbi->s_nilfs;
 350
 351         nilfs_detach_segment_constructor(sbi);
 352
 353         if (!(sb->s_flags & MS_RDONLY)) {
 354                 down_write(&nilfs->ns_sem);
 355                 nilfs_cleanup_super(sbi);
 356                 up_write(&nilfs->ns_sem);
 357         }
 358         down_write(&nilfs->ns_super_sem);
 359         if (nilfs->ns_current == sbi)
 360                 nilfs->ns_current = NULL;
 361         list_del_init(&sbi->s_list);
 362         up_write(&nilfs->ns_super_sem);
 363
 364         put_nilfs(sbi->s_nilfs);
 365         sbi->s_super = NULL;
 366         sb->s_fs_info = NULL;
 367         nilfs_put_sbinfo(sbi);
 368 }
 369
 370 static int nilfs_sync_fs(struct super_block *sb, int wait)
 371 {
 372         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 373         struct the_nilfs *nilfs = sbi->s_nilfs;
 374         struct nilfs_super_block **sbp;
 375         int err = 0;
 376
 377         /* This function is called when super block should be written back */
 378         if (wait)
 379                 err = nilfs_construct_segment(sb);
 380
 381         down_write(&nilfs->ns_sem);
 382         if (nilfs_sb_dirty(nilfs)) {
 383                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 384                 if (likely(sbp)) {
 385                         nilfs_set_log_cursor(sbp[0], nilfs);
 386                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 387                 }
 388         }
 389         up_write(&nilfs->ns_sem);
 390
 391         return err;
 392 }
 393
 394 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 395                             struct nilfs_root **rootp)
 396 {
 397         struct the_nilfs *nilfs = sbi->s_nilfs;
 398         struct nilfs_root *root;
 399         struct nilfs_checkpoint *raw_cp;
 400         struct buffer_head *bh_cp;
 401         int err = -ENOMEM;
 402
 403         root = nilfs_find_or_create_root(
 404                 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
 405         if (!root)
 406                 return err;
 407
 408         if (root->ifile)
 409                 goto reuse; /* already attached checkpoint */
 410
 411         root->ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
 412         if (!root->ifile)
 413                 goto failed;
 414
 415         down_read(&nilfs->ns_segctor_sem);
 416         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 417                                           &bh_cp);
 418         up_read(&nilfs->ns_segctor_sem);
 419         if (unlikely(err)) {
 420                 if (err == -ENOENT || err == -EINVAL) {
 421                         printk(KERN_ERR
 422                                "NILFS: Invalid checkpoint "
 423                                "(checkpoint number=%llu)\n",
 424                                (unsigned long long)cno);
 425                         err = -EINVAL;
 426                 }
 427                 goto failed;
 428         }
 429         err = nilfs_read_inode_common(root->ifile, &raw_cp->cp_ifile_inode);
 430         if (unlikely(err))
 431                 goto failed_bh;
 432
 433         atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 434         atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 435
 436         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 437
 438  reuse:
 439         *rootp = root;
 440         return 0;
 441
 442  failed_bh:
 443         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 444  failed:
 445         nilfs_put_root(root);
 446
 447         return err;
 448 }
 449
 450 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 451 {
 452         struct super_block *sb = dentry->d_sb;
 453         struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
 454         struct the_nilfs *nilfs = root->nilfs;
 455         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 456         unsigned long long blocks;
 457         unsigned long overhead;
 458         unsigned long nrsvblocks;
 459         sector_t nfreeblocks;
 460         int err;
 461
 462         /*
 463          * Compute all of the segment blocks
 464          *
 465          * The blocks before first segment and after last segment
 466          * are excluded.
 467          */
 468         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 469                 - nilfs->ns_first_data_block;
 470         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 471
 472         /*
 473          * Compute the overhead
 474          *
 475          * When distributing meta data blocks outside segment structure,
 476          * We must count them as the overhead.
 477          */
 478         overhead = 0;
 479
 480         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 481         if (unlikely(err))
 482                 return err;
 483
 484         buf->f_type = NILFS_SUPER_MAGIC;
 485         buf->f_bsize = sb->s_blocksize;
 486         buf->f_blocks = blocks - overhead;
 487         buf->f_bfree = nfreeblocks;
 488         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 489                 (buf->f_bfree - nrsvblocks) : 0;
 490         buf->f_files = atomic_read(&root->inodes_count);
 491         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 492         buf->f_namelen = NILFS_NAME_LEN;
 493         buf->f_fsid.val[0] = (u32)id;
 494         buf->f_fsid.val[1] = (u32)(id >> 32);
 495
 496         return 0;
 497 }
 498
 499 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 500 {
 501         struct super_block *sb = vfs->mnt_sb;
 502         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 503
 504         if (!nilfs_test_opt(sbi, BARRIER))
 505                 seq_puts(seq, ",nobarrier");
 506         if (nilfs_test_opt(sbi, SNAPSHOT))
 507                 seq_printf(seq, ",cp=%llu",
 508                            (unsigned long long int)sbi->s_snapshot_cno);
 509         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 510                 seq_puts(seq, ",errors=panic");
 511         if (nilfs_test_opt(sbi, ERRORS_CONT))
 512                 seq_puts(seq, ",errors=continue");
 513         if (nilfs_test_opt(sbi, STRICT_ORDER))
 514                 seq_puts(seq, ",order=strict");
 515         if (nilfs_test_opt(sbi, NORECOVERY))
 516                 seq_puts(seq, ",norecovery");
 517         if (nilfs_test_opt(sbi, DISCARD))
 518                 seq_puts(seq, ",discard");
 519
 520         return 0;
 521 }
 522
 523 static const struct super_operations nilfs_sops = {
 524         .alloc_inode    = nilfs_alloc_inode,
 525         .destroy_inode  = nilfs_destroy_inode,
 526         .dirty_inode    = nilfs_dirty_inode,
 527         /* .write_inode    = nilfs_write_inode, */
 528         /* .put_inode      = nilfs_put_inode, */
 529         /* .drop_inode    = nilfs_drop_inode, */
 530         .evict_inode    = nilfs_evict_inode,
 531         .put_super      = nilfs_put_super,
 532         /* .write_super    = nilfs_write_super, */
 533         .sync_fs        = nilfs_sync_fs,
 534         /* .write_super_lockfs */
 535         /* .unlockfs */
 536         .statfs         = nilfs_statfs,
 537         .remount_fs     = nilfs_remount,
 538         /* .umount_begin */
 539         .show_options = nilfs_show_options
 540 };
 541
 542 enum {
 543         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 544         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 545         Opt_discard, Opt_nodiscard, Opt_err,
 546 };
 547
 548 static match_table_t tokens = {
 549         {Opt_err_cont, "errors=continue"},
 550         {Opt_err_panic, "errors=panic"},
 551         {Opt_err_ro, "errors=remount-ro"},
 552         {Opt_barrier, "barrier"},
 553         {Opt_nobarrier, "nobarrier"},
 554         {Opt_snapshot, "cp=%u"},
 555         {Opt_order, "order=%s"},
 556         {Opt_norecovery, "norecovery"},
 557         {Opt_discard, "discard"},
 558         {Opt_nodiscard, "nodiscard"},
 559         {Opt_err, NULL}
 560 };
 561
 562 static int parse_options(char *options, struct super_block *sb, int is_remount)
 563 {
 564         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 565         char *p;
 566         substring_t args[MAX_OPT_ARGS];
 567         int option;
 568
 569         if (!options)
 570                 return 1;
 571
 572         while ((p = strsep(&options, ",")) != NULL) {
 573                 int token;
 574                 if (!*p)
 575                         continue;
 576
 577                 token = match_token(p, tokens, args);
 578                 switch (token) {
 579                 case Opt_barrier:
 580                         nilfs_set_opt(sbi, BARRIER);
 581                         break;
 582                 case Opt_nobarrier:
 583                         nilfs_clear_opt(sbi, BARRIER);
 584                         break;
 585                 case Opt_order:
 586                         if (strcmp(args[0].from, "relaxed") == 0)
 587                                 /* Ordered data semantics */
 588                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 589                         else if (strcmp(args[0].from, "strict") == 0)
 590                                 /* Strict in-order semantics */
 591                                 nilfs_set_opt(sbi, STRICT_ORDER);
 592                         else
 593                                 return 0;
 594                         break;
 595                 case Opt_err_panic:
 596                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 597                         break;
 598                 case Opt_err_ro:
 599                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 600                         break;
 601                 case Opt_err_cont:
 602                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 603                         break;
 604                 case Opt_snapshot:
 605                         if (match_int(&args[0], &option) || option <= 0)
 606                                 return 0;
 607                         if (is_remount) {
 608                                 if (!nilfs_test_opt(sbi, SNAPSHOT)) {
 609                                         printk(KERN_ERR
 610                                                "NILFS: cannot change regular "
 611                                                "mount to snapshot.\n");
 612                                         return 0;
 613                                 } else if (option != sbi->s_snapshot_cno) {
 614                                         printk(KERN_ERR
 615                                                "NILFS: cannot remount to a "
 616                                                "different snapshot.\n");
 617                                         return 0;
 618                                 }
 619                                 break;
 620                         }
 621                         if (!(sb->s_flags & MS_RDONLY)) {
 622                                 printk(KERN_ERR "NILFS: cannot mount snapshot "
 623                                        "read/write.  A read-only option is "
 624                                        "required.\n");
 625                                 return 0;
 626                         }
 627                         sbi->s_snapshot_cno = option;
 628                         nilfs_set_opt(sbi, SNAPSHOT);
 629                         break;
 630                 case Opt_norecovery:
 631                         nilfs_set_opt(sbi, NORECOVERY);
 632                         break;
 633                 case Opt_discard:
 634                         nilfs_set_opt(sbi, DISCARD);
 635                         break;
 636                 case Opt_nodiscard:
 637                         nilfs_clear_opt(sbi, DISCARD);
 638                         break;
 639                 default:
 640                         printk(KERN_ERR
 641                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 642                         return 0;
 643                 }
 644         }
 645         return 1;
 646 }
 647
 648 static inline void
 649 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 650                           struct nilfs_super_block *sbp)
 651 {
 652         sbi->s_mount_opt =
 653                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 654 }
 655
 656 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 657 {
 658         struct the_nilfs *nilfs = sbi->s_nilfs;
 659         struct nilfs_super_block **sbp;
 660         int max_mnt_count;
 661         int mnt_count;
 662
 663         /* nilfs->ns_sem must be locked by the caller. */
 664         sbp = nilfs_prepare_super(sbi, 0);
 665         if (!sbp)
 666                 return -EIO;
 667
 668         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 669         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 670
 671         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 672                 printk(KERN_WARNING
 673                        "NILFS warning: mounting fs with errors\n");
 674 #if 0
 675         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 676                 printk(KERN_WARNING
 677                        "NILFS warning: maximal mount count reached\n");
 678 #endif
 679         }
 680         if (!max_mnt_count)
 681                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 682
 683         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 684         sbp[0]->s_state =
 685                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 686         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 687         /* synchronize sbp[1] with sbp[0] */
 688         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 689         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 690 }
 691
 692 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 693                                                  u64 pos, int blocksize,
 694                                                  struct buffer_head **pbh)
 695 {
 696         unsigned long long sb_index = pos;
 697         unsigned long offset;
 698
 699         offset = do_div(sb_index, blocksize);
 700         *pbh = sb_bread(sb, sb_index);
 701         if (!*pbh)
 702                 return NULL;
 703         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 704 }
 705
 706 int nilfs_store_magic_and_option(struct super_block *sb,
 707                                  struct nilfs_super_block *sbp,
 708                                  char *data)
 709 {
 710         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 711
 712         sb->s_magic = le16_to_cpu(sbp->s_magic);
 713
 714         /* FS independent flags */
 715 #ifdef NILFS_ATIME_DISABLE
 716         sb->s_flags |= MS_NOATIME;
 717 #endif
 718
 719         nilfs_set_default_options(sbi, sbp);
 720
 721         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 722         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 723         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 724         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 725
 726         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 727 }
 728
 729 int nilfs_check_feature_compatibility(struct super_block *sb,
 730                                       struct nilfs_super_block *sbp)
 731 {
 732         __u64 features;
 733
 734         features = le64_to_cpu(sbp->s_feature_incompat) &
 735                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 736         if (features) {
 737                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 738                        "optional features (%llx)\n",
 739                        (unsigned long long)features);
 740                 return -EINVAL;
 741         }
 742         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 743                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 744         if (!(sb->s_flags & MS_RDONLY) && features) {
 745                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 746                        "unsupported optional features (%llx)\n",
 747                        (unsigned long long)features);
 748                 return -EINVAL;
 749         }
 750         return 0;
 751 }
 752
 753 static int nilfs_get_root_dentry(struct super_block *sb,
 754                                  struct nilfs_root *root,
 755                                  struct dentry **root_dentry)
 756 {
 757         struct inode *inode;
 758         struct dentry *dentry;
 759         int ret = 0;
 760
 761         inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
 762         if (IS_ERR(inode)) {
 763                 printk(KERN_ERR "NILFS: get root inode failed\n");
 764                 ret = PTR_ERR(inode);
 765                 goto out;
 766         }
 767         if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
 768                 iput(inode);
 769                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 770                 ret = -EINVAL;
 771                 goto out;
 772         }
 773
 774         dentry = d_alloc_root(inode);
 775         if (!dentry) {
 776                 iput(inode);
 777                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 778                 ret = -ENOMEM;
 779                 goto out;
 780         }
 781         *root_dentry = dentry;
 782  out:
 783         return ret;
 784 }
 785
 786 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 787                                  struct dentry **root_dentry)
 788 {
 789         struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
 790         struct nilfs_root *root;
 791         int ret;
 792
 793         down_read(&nilfs->ns_segctor_sem);
 794         ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
 795         up_read(&nilfs->ns_segctor_sem);
 796         if (ret < 0) {
 797                 ret = (ret == -ENOENT) ? -EINVAL : ret;
 798                 goto out;
 799         } else if (!ret) {
 800                 printk(KERN_ERR "NILFS: The specified checkpoint is "
 801                        "not a snapshot (checkpoint number=%llu).\n",
 802                        (unsigned long long)cno);
 803                 ret = -EINVAL;
 804                 goto out;
 805         }
 806
 807         ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
 808         if (ret) {
 809                 printk(KERN_ERR "NILFS: error loading snapshot "
 810                        "(checkpoint number=%llu).\n",
 811                (unsigned long long)cno);
 812                 goto out;
 813         }
 814         ret = nilfs_get_root_dentry(s, root, root_dentry);
 815         nilfs_put_root(root);
 816  out:
 817         return ret;
 818 }
 819
 820 /**
 821  * nilfs_fill_super() - initialize a super block instance
 822  * @sb: super_block
 823  * @data: mount options
 824  * @silent: silent mode flag
 825  * @nilfs: the_nilfs struct
 826  *
 827  * This function is called exclusively by nilfs->ns_mount_mutex.
 828  * So, the recovery process is protected from other simultaneous mounts.
 829  */
 830 static int
 831 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 832                  struct the_nilfs *nilfs)
 833 {
 834         struct nilfs_sb_info *sbi;
 835         struct nilfs_root *fsroot;
 836         __u64 cno;
 837         int err;
 838
 839         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 840         if (!sbi)
 841                 return -ENOMEM;
 842
 843         sb->s_fs_info = sbi;
 844
 845         get_nilfs(nilfs);
 846         sbi->s_nilfs = nilfs;
 847         sbi->s_super = sb;
 848         atomic_set(&sbi->s_count, 1);
 849
 850         err = init_nilfs(nilfs, sbi, (char *)data);
 851         if (err)
 852                 goto failed_sbi;
 853
 854         spin_lock_init(&sbi->s_inode_lock);
 855         INIT_LIST_HEAD(&sbi->s_dirty_files);
 856         INIT_LIST_HEAD(&sbi->s_list);
 857
 858         /*
 859          * Following initialization is overlapped because
 860          * nilfs_sb_info structure has been cleared at the beginning.
 861          * But we reserve them to keep our interest and make ready
 862          * for the future change.
 863          */
 864         get_random_bytes(&sbi->s_next_generation,
 865                          sizeof(sbi->s_next_generation));
 866         spin_lock_init(&sbi->s_next_gen_lock);
 867
 868         sb->s_op = &nilfs_sops;
 869         sb->s_export_op = &nilfs_export_ops;
 870         sb->s_root = NULL;
 871         sb->s_time_gran = 1;
 872         sb->s_bdi = nilfs->ns_bdi;
 873
 874         err = load_nilfs(nilfs, sbi);
 875         if (err)
 876                 goto failed_sbi;
 877
 878         if (nilfs_test_opt(sbi, SNAPSHOT)) {
 879                 err = nilfs_attach_snapshot(sb, sbi->s_snapshot_cno,
 880                                             &sb->s_root);
 881                 if (err)
 882                         goto failed_sbi;
 883
 884                 goto add_to_supers;
 885         }
 886
 887         cno = nilfs_last_cno(nilfs);
 888         err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
 889         if (err) {
 890                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 891                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 892                 goto failed_sbi;
 893         }
 894
 895         if (!(sb->s_flags & MS_RDONLY)) {
 896                 err = nilfs_attach_segment_constructor(sbi, fsroot);
 897                 if (err)
 898                         goto failed_checkpoint;
 899         }
 900
 901         err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
 902         if (err)
 903                 goto failed_segctor;
 904
 905         nilfs_put_root(fsroot);
 906
 907         if (!(sb->s_flags & MS_RDONLY)) {
 908                 down_write(&nilfs->ns_sem);
 909                 nilfs_setup_super(sbi);
 910                 up_write(&nilfs->ns_sem);
 911         }
 912
 913  add_to_supers:
 914         down_write(&nilfs->ns_super_sem);
 915         list_add(&sbi->s_list, &nilfs->ns_supers);
 916         if (!nilfs_test_opt(sbi, SNAPSHOT))
 917                 nilfs->ns_current = sbi;
 918         up_write(&nilfs->ns_super_sem);
 919
 920         return 0;
 921
 922  failed_segctor:
 923         nilfs_detach_segment_constructor(sbi);
 924
 925  failed_checkpoint:
 926         nilfs_put_root(fsroot);
 927
 928  failed_sbi:
 929         put_nilfs(nilfs);
 930         sb->s_fs_info = NULL;
 931         nilfs_put_sbinfo(sbi);
 932         return err;
 933 }
 934
 935 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 936 {
 937         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 938         struct the_nilfs *nilfs = sbi->s_nilfs;
 939         unsigned long old_sb_flags;
 940         struct nilfs_mount_options old_opts;
 941         int was_snapshot, err;
 942
 943         down_write(&nilfs->ns_super_sem);
 944         old_sb_flags = sb->s_flags;
 945         old_opts.mount_opt = sbi->s_mount_opt;
 946         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 947         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 948
 949         if (!parse_options(data, sb, 1)) {
 950                 err = -EINVAL;
 951                 goto restore_opts;
 952         }
 953         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 954
 955         err = -EINVAL;
 956         if (was_snapshot && !(*flags & MS_RDONLY)) {
 957                 printk(KERN_ERR "NILFS (device %s): cannot remount snapshot "
 958                        "read/write.\n", sb->s_id);
 959                 goto restore_opts;
 960         }
 961
 962         if (!nilfs_valid_fs(nilfs)) {
 963                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 964                        "remount because the filesystem is in an "
 965                        "incomplete recovery state.\n", sb->s_id);
 966                 goto restore_opts;
 967         }
 968
 969         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 970                 goto out;
 971         if (*flags & MS_RDONLY) {
 972                 /* Shutting down the segment constructor */
 973                 nilfs_detach_segment_constructor(sbi);
 974                 sb->s_flags |= MS_RDONLY;
 975
 976                 /*
 977                  * Remounting a valid RW partition RDONLY, so set
 978                  * the RDONLY flag and then mark the partition as valid again.
 979                  */
 980                 down_write(&nilfs->ns_sem);
 981                 nilfs_cleanup_super(sbi);
 982                 up_write(&nilfs->ns_sem);
 983         } else {
 984                 __u64 features;
 985                 struct nilfs_root *root;
 986
 987                 /*
 988                  * Mounting a RDONLY partition read-write, so reread and
 989                  * store the current valid flag.  (It may have been changed
 990                  * by fsck since we originally mounted the partition.)
 991                  */
 992                 down_read(&nilfs->ns_sem);
 993                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
 994                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
 995                 up_read(&nilfs->ns_sem);
 996                 if (features) {
 997                         printk(KERN_WARNING "NILFS (device %s): couldn't "
 998                                "remount RDWR because of unsupported optional "
 999                                "features (%llx)\n",
1000                                sb->s_id, (unsigned long long)features);
1001                         err = -EROFS;
1002                         goto restore_opts;
1003                 }
1004
1005                 sb->s_flags &= ~MS_RDONLY;
1006
1007                 root = NILFS_I(sb->s_root->d_inode)->i_root;
1008                 err = nilfs_attach_segment_constructor(sbi, root);
1009                 if (err)
1010                         goto restore_opts;
1011
1012                 down_write(&nilfs->ns_sem);
1013                 nilfs_setup_super(sbi);
1014                 up_write(&nilfs->ns_sem);
1015         }
1016  out:
1017         up_write(&nilfs->ns_super_sem);
1018         return 0;
1019
1020  restore_opts:
1021         sb->s_flags = old_sb_flags;
1022         sbi->s_mount_opt = old_opts.mount_opt;
1023         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1024         up_write(&nilfs->ns_super_sem);
1025         return err;
1026 }
1027
1028 struct nilfs_super_data {
1029         struct block_device *bdev;
1030         struct nilfs_sb_info *sbi;
1031         __u64 cno;
1032         int flags;
1033 };
1034
1035 /**
1036  * nilfs_identify - pre-read mount options needed to identify mount instance
1037  * @data: mount options
1038  * @sd: nilfs_super_data
1039  */
1040 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1041 {
1042         char *p, *options = data;
1043         substring_t args[MAX_OPT_ARGS];
1044         int option, token;
1045         int ret = 0;
1046
1047         do {
1048                 p = strsep(&options, ",");
1049                 if (p != NULL && *p) {
1050                         token = match_token(p, tokens, args);
1051                         if (token == Opt_snapshot) {
1052                                 if (!(sd->flags & MS_RDONLY))
1053                                         ret++;
1054                                 else {
1055                                         ret = match_int(&args[0], &option);
1056                                         if (!ret) {
1057                                                 if (option > 0)
1058                                                         sd->cno = option;
1059                                                 else
1060                                                         ret++;
1061                                         }
1062                                 }
1063                         }
1064                         if (ret)
1065                                 printk(KERN_ERR
1066                                        "NILFS: invalid mount option: %s\n", p);
1067                 }
1068                 if (!options)
1069                         break;
1070                 BUG_ON(options == data);
1071                 *(options - 1) = ',';
1072         } while (!ret);
1073         return ret;
1074 }
1075
1076 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1077 {
1078         struct nilfs_super_data *sd = data;
1079
1080         s->s_bdev = sd->bdev;
1081         s->s_dev = s->s_bdev->bd_dev;
1082         return 0;
1083 }
1084
1085 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1086 {
1087         struct nilfs_super_data *sd = data;
1088
1089         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1090 }
1091
1092 static int
1093 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1094              const char *dev_name, void *data, struct vfsmount *mnt)
1095 {
1096         struct nilfs_super_data sd;
1097         struct super_block *s;
1098         fmode_t mode = FMODE_READ;
1099         struct the_nilfs *nilfs;
1100         int err, need_to_close = 1;
1101
1102         if (!(flags & MS_RDONLY))
1103                 mode |= FMODE_WRITE;
1104
1105         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1106         if (IS_ERR(sd.bdev))
1107                 return PTR_ERR(sd.bdev);
1108
1109         /*
1110          * To get mount instance using sget() vfs-routine, NILFS needs
1111          * much more information than normal filesystems to identify mount
1112          * instance.  For snapshot mounts, not only a mount type (ro-mount
1113          * or rw-mount) but also a checkpoint number is required.
1114          */
1115         sd.cno = 0;
1116         sd.flags = flags;
1117         if (nilfs_identify((char *)data, &sd)) {
1118                 err = -EINVAL;
1119                 goto failed;
1120         }
1121
1122         nilfs = find_or_create_nilfs(sd.bdev);
1123         if (!nilfs) {
1124                 err = -ENOMEM;
1125                 goto failed;
1126         }
1127
1128         mutex_lock(&nilfs->ns_mount_mutex);
1129
1130         if (!sd.cno) {
1131                 /*
1132                  * Check if an exclusive mount exists or not.
1133                  * Snapshot mounts coexist with a current mount
1134                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1135                  * ro-mount are mutually exclusive.
1136                  */
1137                 down_read(&nilfs->ns_super_sem);
1138                 if (nilfs->ns_current &&
1139                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1140                      & MS_RDONLY)) {
1141                         up_read(&nilfs->ns_super_sem);
1142                         err = -EBUSY;
1143                         goto failed_unlock;
1144                 }
1145                 up_read(&nilfs->ns_super_sem);
1146         }
1147
1148         /*
1149          * Find existing nilfs_sb_info struct
1150          */
1151         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1152
1153         /*
1154          * Get super block instance holding the nilfs_sb_info struct.
1155          * A new instance is allocated if no existing mount is present or
1156          * existing instance has been unmounted.
1157          */
1158         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1159         if (sd.sbi)
1160                 nilfs_put_sbinfo(sd.sbi);
1161
1162         if (IS_ERR(s)) {
1163                 err = PTR_ERR(s);
1164                 goto failed_unlock;
1165         }
1166
1167         if (!s->s_root) {
1168                 char b[BDEVNAME_SIZE];
1169
1170                 /* New superblock instance created */
1171                 s->s_flags = flags;
1172                 s->s_mode = mode;
1173                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1174                 sb_set_blocksize(s, block_size(sd.bdev));
1175
1176                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1177                                        nilfs);
1178                 if (err)
1179                         goto cancel_new;
1180
1181                 s->s_flags |= MS_ACTIVE;
1182                 need_to_close = 0;
1183         }
1184
1185         mutex_unlock(&nilfs->ns_mount_mutex);
1186         put_nilfs(nilfs);
1187         if (need_to_close)
1188                 close_bdev_exclusive(sd.bdev, mode);
1189         simple_set_mnt(mnt, s);
1190         return 0;
1191
1192  failed_unlock:
1193         mutex_unlock(&nilfs->ns_mount_mutex);
1194         put_nilfs(nilfs);
1195  failed:
1196         close_bdev_exclusive(sd.bdev, mode);
1197         return err;
1198
1199  cancel_new:
1200         /* Abandoning the newly allocated superblock */
1201         mutex_unlock(&nilfs->ns_mount_mutex);
1202         put_nilfs(nilfs);
1203         deactivate_locked_super(s);
1204         /*
1205          * deactivate_locked_super() invokes close_bdev_exclusive().
1206          * We must finish all post-cleaning before this call;
1207          * put_nilfs() needs the block device.
1208          */
1209         return err;
1210 }
1211
1212 struct file_system_type nilfs_fs_type = {
1213         .owner    = THIS_MODULE,
1214         .name     = "nilfs2",
1215         .get_sb   = nilfs_get_sb,
1216         .kill_sb  = kill_block_super,
1217         .fs_flags = FS_REQUIRES_DEV,
1218 };
1219
1220 static void nilfs_inode_init_once(void *obj)
1221 {
1222         struct nilfs_inode_info *ii = obj;
1223
1224         INIT_LIST_HEAD(&ii->i_dirty);
1225 #ifdef CONFIG_NILFS_XATTR
1226         init_rwsem(&ii->xattr_sem);
1227 #endif
1228         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1229         ii->i_bmap = &ii->i_bmap_data;
1230         inode_init_once(&ii->vfs_inode);
1231 }
1232
1233 static void nilfs_segbuf_init_once(void *obj)
1234 {
1235         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1236 }
1237
1238 static void nilfs_destroy_cachep(void)
1239 {
1240         if (nilfs_inode_cachep)
1241                 kmem_cache_destroy(nilfs_inode_cachep);
1242         if (nilfs_transaction_cachep)
1243                 kmem_cache_destroy(nilfs_transaction_cachep);
1244         if (nilfs_segbuf_cachep)
1245                 kmem_cache_destroy(nilfs_segbuf_cachep);
1246         if (nilfs_btree_path_cache)
1247                 kmem_cache_destroy(nilfs_btree_path_cache);
1248 }
1249
1250 static int __init nilfs_init_cachep(void)
1251 {
1252         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1253                         sizeof(struct nilfs_inode_info), 0,
1254                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1255         if (!nilfs_inode_cachep)
1256                 goto fail;
1257
1258         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1259                         sizeof(struct nilfs_transaction_info), 0,
1260                         SLAB_RECLAIM_ACCOUNT, NULL);
1261         if (!nilfs_transaction_cachep)
1262                 goto fail;
1263
1264         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1265                         sizeof(struct nilfs_segment_buffer), 0,
1266                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1267         if (!nilfs_segbuf_cachep)
1268                 goto fail;
1269
1270         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1271                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1272                         0, 0, NULL);
1273         if (!nilfs_btree_path_cache)
1274                 goto fail;
1275
1276         return 0;
1277
1278 fail:
1279         nilfs_destroy_cachep();
1280         return -ENOMEM;
1281 }
1282
1283 static int __init init_nilfs_fs(void)
1284 {
1285         int err;
1286
1287         err = nilfs_init_cachep();
1288         if (err)
1289                 goto fail;
1290
1291         err = register_filesystem(&nilfs_fs_type);
1292         if (err)
1293                 goto free_cachep;
1294
1295         printk(KERN_INFO "NILFS version 2 loaded\n");
1296         return 0;
1297
1298 free_cachep:
1299         nilfs_destroy_cachep();
1300 fail:
1301         return err;
1302 }
1303
1304 static void __exit exit_nilfs_fs(void)
1305 {
1306         nilfs_destroy_cachep();
1307         unregister_filesystem(&nilfs_fs_type);
1308 }
1309
1310 module_init(init_nilfs_fs)
1311 module_exit(exit_nilfs_fs)