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