fs/nilfs2/super.c

   1 /*
   2  * super.c - NILFS module and super block management.
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21  */
  22 /*
  23  *  linux/fs/ext2/super.c
  24  *
  25  * Copyright (C) 1992, 1993, 1994, 1995
  26  * Remy Card (card@masi.ibp.fr)
  27  * Laboratoire MASI - Institut Blaise Pascal
  28  * Universite Pierre et Marie Curie (Paris VI)
  29  *
  30  *  from
  31  *
  32  *  linux/fs/minix/inode.c
  33  *
  34  *  Copyright (C) 1991, 1992  Linus Torvalds
  35  *
  36  *  Big-endian to little-endian byte-swapping/bitmaps by
  37  *        David S. Miller (davem@caip.rutgers.edu), 1995
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/string.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/parser.h>
  46 #include <linux/random.h>
  47 #include <linux/crc32.h>
  48 #include <linux/smp_lock.h>
  49 #include <linux/vfs.h>
  50 #include <linux/writeback.h>
  51 #include <linux/kobject.h>
  52 #include <linux/exportfs.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/mount.h>
  55 #include "nilfs.h"
  56 #include "mdt.h"
  57 #include "alloc.h"
  58 #include "btree.h"
  59 #include "btnode.h"
  60 #include "page.h"
  61 #include "cpfile.h"
  62 #include "ifile.h"
  63 #include "dat.h"
  64 #include "segment.h"
  65 #include "segbuf.h"
  66
  67 MODULE_AUTHOR("NTT Corp.");
  68 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  69                    "(NILFS)");
  70 MODULE_LICENSE("GPL");
  71
  72 struct kmem_cache *nilfs_inode_cachep;
  73 struct kmem_cache *nilfs_transaction_cachep;
  74 struct kmem_cache *nilfs_segbuf_cachep;
  75 struct kmem_cache *nilfs_btree_path_cache;
  76
  77 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  78
  79 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  80 {
  81         struct the_nilfs *nilfs = sbi->s_nilfs;
  82         struct nilfs_super_block **sbp;
  83
  84         down_write(&nilfs->ns_sem);
  85         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  86                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  87                 sbp = nilfs_prepare_super(sbi, 0);
  88                 if (likely(sbp)) {
  89                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  90                         if (sbp[1])
  91                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  92                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  93                 }
  94         }
  95         up_write(&nilfs->ns_sem);
  96 }
  97
  98 /**
  99  * nilfs_error() - report failure condition on a filesystem
 100  *
 101  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 102  * reporting an error message.  It should be called when NILFS detects
 103  * incoherences or defects of meta data on disk.  As for sustainable
 104  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 105  * function should be used instead.
 106  *
 107  * The segment constructor must not call this function because it can
 108  * kill itself.
 109  */
 110 void nilfs_error(struct super_block *sb, const char *function,
 111                  const char *fmt, ...)
 112 {
 113         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 114         va_list args;
 115
 116         va_start(args, fmt);
 117         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 118         vprintk(fmt, args);
 119         printk("\n");
 120         va_end(args);
 121
 122         if (!(sb->s_flags & MS_RDONLY)) {
 123                 nilfs_set_error(sbi);
 124
 125                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 126                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 127                         sb->s_flags |= MS_RDONLY;
 128                 }
 129         }
 130
 131         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 132                 panic("NILFS (device %s): panic forced after error\n",
 133                       sb->s_id);
 134 }
 135
 136 void nilfs_warning(struct super_block *sb, const char *function,
 137                    const char *fmt, ...)
 138 {
 139         va_list args;
 140
 141         va_start(args, fmt);
 142         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 143                sb->s_id, function);
 144         vprintk(fmt, args);
 145         printk("\n");
 146         va_end(args);
 147 }
 148
 149
 150 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 151 {
 152         struct nilfs_inode_info *ii;
 153
 154         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 155         if (!ii)
 156                 return NULL;
 157         ii->i_bh = NULL;
 158         ii->i_state = 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         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 172 }
 173
 174 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 175 {
 176         struct the_nilfs *nilfs = sbi->s_nilfs;
 177         int err;
 178
 179  retry:
 180         set_buffer_dirty(nilfs->ns_sbh[0]);
 181         if (nilfs_test_opt(sbi, BARRIER)) {
 182                 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 183                                           WRITE_SYNC | WRITE_FLUSH_FUA);
 184         } else {
 185                 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 186         }
 187
 188         if (unlikely(err)) {
 189                 printk(KERN_ERR
 190                        "NILFS: unable to write superblock (err=%d)\n", err);
 191                 if (err == -EIO && nilfs->ns_sbh[1]) {
 192                         /*
 193                          * sbp[0] points to newer log than sbp[1],
 194                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 195                          */
 196                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 197                                nilfs->ns_sbsize);
 198                         nilfs_fall_back_super_block(nilfs);
 199                         goto retry;
 200                 }
 201         } else {
 202                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 203
 204                 nilfs->ns_sbwcount++;
 205
 206                 /*
 207                  * The latest segment becomes trailable from the position
 208                  * written in superblock.
 209                  */
 210                 clear_nilfs_discontinued(nilfs);
 211
 212                 /* update GC protection for recent segments */
 213                 if (nilfs->ns_sbh[1]) {
 214                         if (flag == NILFS_SB_COMMIT_ALL) {
 215                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 216                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 217                                         goto out;
 218                         }
 219                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 220                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 221                                 sbp = nilfs->ns_sbp[1];
 222                 }
 223
 224                 spin_lock(&nilfs->ns_last_segment_lock);
 225                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 226                 spin_unlock(&nilfs->ns_last_segment_lock);
 227         }
 228  out:
 229         return err;
 230 }
 231
 232 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 233                           struct the_nilfs *nilfs)
 234 {
 235         sector_t nfreeblocks;
 236
 237         /* nilfs->ns_sem must be locked by the caller. */
 238         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 239         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 240
 241         spin_lock(&nilfs->ns_last_segment_lock);
 242         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 243         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 244         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 245         spin_unlock(&nilfs->ns_last_segment_lock);
 246 }
 247
 248 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 249                                                int flip)
 250 {
 251         struct the_nilfs *nilfs = sbi->s_nilfs;
 252         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 253
 254         /* nilfs->ns_sem must be locked by the caller. */
 255         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 256                 if (sbp[1] &&
 257                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 258                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 259                 } else {
 260                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 261                                sbi->s_super->s_id);
 262                         return NULL;
 263                 }
 264         } else if (sbp[1] &&
 265                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 266                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 267         }
 268
 269         if (flip && sbp[1])
 270                 nilfs_swap_super_block(nilfs);
 271
 272         return sbp;
 273 }
 274
 275 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 276 {
 277         struct the_nilfs *nilfs = sbi->s_nilfs;
 278         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 279         time_t t;
 280
 281         /* nilfs->ns_sem must be locked by the caller. */
 282         t = get_seconds();
 283         nilfs->ns_sbwtime = t;
 284         sbp[0]->s_wtime = cpu_to_le64(t);
 285         sbp[0]->s_sum = 0;
 286         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 287                                              (unsigned char *)sbp[0],
 288                                              nilfs->ns_sbsize));
 289         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 290                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 291                 sbp[1]->s_sum = 0;
 292                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 293                                             (unsigned char *)sbp[1],
 294                                             nilfs->ns_sbsize));
 295         }
 296         clear_nilfs_sb_dirty(nilfs);
 297         return nilfs_sync_super(sbi, flag);
 298 }
 299
 300 /**
 301  * nilfs_cleanup_super() - write filesystem state for cleanup
 302  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 303  *
 304  * This function restores state flags in the on-disk super block.
 305  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 306  * filesystem was not clean previously.
 307  */
 308 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 309 {
 310         struct nilfs_super_block **sbp;
 311         int flag = NILFS_SB_COMMIT;
 312         int ret = -EIO;
 313
 314         sbp = nilfs_prepare_super(sbi, 0);
 315         if (sbp) {
 316                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 317                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 318                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 319                         /*
 320                          * make the "clean" flag also to the opposite
 321                          * super block if both super blocks point to
 322                          * the same checkpoint.
 323                          */
 324                         sbp[1]->s_state = sbp[0]->s_state;
 325                         flag = NILFS_SB_COMMIT_ALL;
 326                 }
 327                 ret = nilfs_commit_super(sbi, flag);
 328         }
 329         return ret;
 330 }
 331
 332 static void nilfs_put_super(struct super_block *sb)
 333 {
 334         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 335         struct the_nilfs *nilfs = sbi->s_nilfs;
 336
 337         lock_kernel();
 338
 339         nilfs_detach_segment_constructor(sbi);
 340
 341         if (!(sb->s_flags & MS_RDONLY)) {
 342                 down_write(&nilfs->ns_sem);
 343                 nilfs_cleanup_super(sbi);
 344                 up_write(&nilfs->ns_sem);
 345         }
 346         down_write(&nilfs->ns_super_sem);
 347         if (nilfs->ns_current == sbi)
 348                 nilfs->ns_current = NULL;
 349         up_write(&nilfs->ns_super_sem);
 350
 351         nilfs_detach_checkpoint(sbi);
 352         put_nilfs(sbi->s_nilfs);
 353         sbi->s_super = NULL;
 354         sb->s_fs_info = NULL;
 355         nilfs_put_sbinfo(sbi);
 356
 357         unlock_kernel();
 358 }
 359
 360 static int nilfs_sync_fs(struct super_block *sb, int wait)
 361 {
 362         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 363         struct the_nilfs *nilfs = sbi->s_nilfs;
 364         struct nilfs_super_block **sbp;
 365         int err = 0;
 366
 367         /* This function is called when super block should be written back */
 368         if (wait)
 369                 err = nilfs_construct_segment(sb);
 370
 371         down_write(&nilfs->ns_sem);
 372         if (nilfs_sb_dirty(nilfs)) {
 373                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 374                 if (likely(sbp)) {
 375                         nilfs_set_log_cursor(sbp[0], nilfs);
 376                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 377                 }
 378         }
 379         up_write(&nilfs->ns_sem);
 380
 381         return err;
 382 }
 383
 384 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
 385 {
 386         struct the_nilfs *nilfs = sbi->s_nilfs;
 387         struct nilfs_checkpoint *raw_cp;
 388         struct buffer_head *bh_cp;
 389         int err;
 390
 391         down_write(&nilfs->ns_super_sem);
 392         list_add(&sbi->s_list, &nilfs->ns_supers);
 393         up_write(&nilfs->ns_super_sem);
 394
 395         err = -ENOMEM;
 396         sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
 397         if (!sbi->s_ifile)
 398                 goto delist;
 399
 400         down_read(&nilfs->ns_segctor_sem);
 401         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 402                                           &bh_cp);
 403         up_read(&nilfs->ns_segctor_sem);
 404         if (unlikely(err)) {
 405                 if (err == -ENOENT || err == -EINVAL) {
 406                         printk(KERN_ERR
 407                                "NILFS: Invalid checkpoint "
 408                                "(checkpoint number=%llu)\n",
 409                                (unsigned long long)cno);
 410                         err = -EINVAL;
 411                 }
 412                 goto failed;
 413         }
 414         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
 415         if (unlikely(err))
 416                 goto failed_bh;
 417         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 418         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 419
 420         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 421         return 0;
 422
 423  failed_bh:
 424         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 425  failed:
 426         nilfs_mdt_destroy(sbi->s_ifile);
 427         sbi->s_ifile = NULL;
 428
 429  delist:
 430         down_write(&nilfs->ns_super_sem);
 431         list_del_init(&sbi->s_list);
 432         up_write(&nilfs->ns_super_sem);
 433
 434         return err;
 435 }
 436
 437 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
 438 {
 439         struct the_nilfs *nilfs = sbi->s_nilfs;
 440
 441         nilfs_mdt_destroy(sbi->s_ifile);
 442         sbi->s_ifile = NULL;
 443         down_write(&nilfs->ns_super_sem);
 444         list_del_init(&sbi->s_list);
 445         up_write(&nilfs->ns_super_sem);
 446 }
 447
 448 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 449 {
 450         struct super_block *sb = dentry->d_sb;
 451         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 452         struct the_nilfs *nilfs = sbi->s_nilfs;
 453         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 454         unsigned long long blocks;
 455         unsigned long overhead;
 456         unsigned long nrsvblocks;
 457         sector_t nfreeblocks;
 458         int err;
 459
 460         /*
 461          * Compute all of the segment blocks
 462          *
 463          * The blocks before first segment and after last segment
 464          * are excluded.
 465          */
 466         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 467                 - nilfs->ns_first_data_block;
 468         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 469
 470         /*
 471          * Compute the overhead
 472          *
 473          * When distributing meta data blocks outside segment structure,
 474          * We must count them as the overhead.
 475          */
 476         overhead = 0;
 477
 478         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 479         if (unlikely(err))
 480                 return err;
 481
 482         buf->f_type = NILFS_SUPER_MAGIC;
 483         buf->f_bsize = sb->s_blocksize;
 484         buf->f_blocks = blocks - overhead;
 485         buf->f_bfree = nfreeblocks;
 486         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 487                 (buf->f_bfree - nrsvblocks) : 0;
 488         buf->f_files = atomic_read(&sbi->s_inodes_count);
 489         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 490         buf->f_namelen = NILFS_NAME_LEN;
 491         buf->f_fsid.val[0] = (u32)id;
 492         buf->f_fsid.val[1] = (u32)(id >> 32);
 493
 494         return 0;
 495 }
 496
 497 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 498 {
 499         struct super_block *sb = vfs->mnt_sb;
 500         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 501
 502         if (!nilfs_test_opt(sbi, BARRIER))
 503                 seq_puts(seq, ",nobarrier");
 504         if (nilfs_test_opt(sbi, SNAPSHOT))
 505                 seq_printf(seq, ",cp=%llu",
 506                            (unsigned long long int)sbi->s_snapshot_cno);
 507         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 508                 seq_puts(seq, ",errors=panic");
 509         if (nilfs_test_opt(sbi, ERRORS_CONT))
 510                 seq_puts(seq, ",errors=continue");
 511         if (nilfs_test_opt(sbi, STRICT_ORDER))
 512                 seq_puts(seq, ",order=strict");
 513         if (nilfs_test_opt(sbi, NORECOVERY))
 514                 seq_puts(seq, ",norecovery");
 515         if (nilfs_test_opt(sbi, DISCARD))
 516                 seq_puts(seq, ",discard");
 517
 518         return 0;
 519 }
 520
 521 static const struct super_operations nilfs_sops = {
 522         .alloc_inode    = nilfs_alloc_inode,
 523         .destroy_inode  = nilfs_destroy_inode,
 524         .dirty_inode    = nilfs_dirty_inode,
 525         /* .write_inode    = nilfs_write_inode, */
 526         /* .put_inode      = nilfs_put_inode, */
 527         /* .drop_inode    = nilfs_drop_inode, */
 528         .evict_inode    = nilfs_evict_inode,
 529         .put_super      = nilfs_put_super,
 530         /* .write_super    = nilfs_write_super, */
 531         .sync_fs        = nilfs_sync_fs,
 532         /* .write_super_lockfs */
 533         /* .unlockfs */
 534         .statfs         = nilfs_statfs,
 535         .remount_fs     = nilfs_remount,
 536         /* .umount_begin */
 537         .show_options = nilfs_show_options
 538 };
 539
 540 static struct inode *
 541 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 542 {
 543         struct inode *inode;
 544
 545         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
 546             ino != NILFS_SKETCH_INO)
 547                 return ERR_PTR(-ESTALE);
 548
 549         inode = nilfs_iget(sb, ino);
 550         if (IS_ERR(inode))
 551                 return ERR_CAST(inode);
 552         if (generation && inode->i_generation != generation) {
 553                 iput(inode);
 554                 return ERR_PTR(-ESTALE);
 555         }
 556
 557         return inode;
 558 }
 559
 560 static struct dentry *
 561 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
 562                    int fh_type)
 563 {
 564         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 565                                     nilfs_nfs_get_inode);
 566 }
 567
 568 static struct dentry *
 569 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
 570                    int fh_type)
 571 {
 572         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 573                                     nilfs_nfs_get_inode);
 574 }
 575
 576 static const struct export_operations nilfs_export_ops = {
 577         .fh_to_dentry = nilfs_fh_to_dentry,
 578         .fh_to_parent = nilfs_fh_to_parent,
 579         .get_parent = nilfs_get_parent,
 580 };
 581
 582 enum {
 583         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 584         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 585         Opt_discard, Opt_nodiscard, Opt_err,
 586 };
 587
 588 static match_table_t tokens = {
 589         {Opt_err_cont, "errors=continue"},
 590         {Opt_err_panic, "errors=panic"},
 591         {Opt_err_ro, "errors=remount-ro"},
 592         {Opt_barrier, "barrier"},
 593         {Opt_nobarrier, "nobarrier"},
 594         {Opt_snapshot, "cp=%u"},
 595         {Opt_order, "order=%s"},
 596         {Opt_norecovery, "norecovery"},
 597         {Opt_discard, "discard"},
 598         {Opt_nodiscard, "nodiscard"},
 599         {Opt_err, NULL}
 600 };
 601
 602 static int parse_options(char *options, struct super_block *sb, int is_remount)
 603 {
 604         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 605         char *p;
 606         substring_t args[MAX_OPT_ARGS];
 607         int option;
 608
 609         if (!options)
 610                 return 1;
 611
 612         while ((p = strsep(&options, ",")) != NULL) {
 613                 int token;
 614                 if (!*p)
 615                         continue;
 616
 617                 token = match_token(p, tokens, args);
 618                 switch (token) {
 619                 case Opt_barrier:
 620                         nilfs_set_opt(sbi, BARRIER);
 621                         break;
 622                 case Opt_nobarrier:
 623                         nilfs_clear_opt(sbi, BARRIER);
 624                         break;
 625                 case Opt_order:
 626                         if (strcmp(args[0].from, "relaxed") == 0)
 627                                 /* Ordered data semantics */
 628                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 629                         else if (strcmp(args[0].from, "strict") == 0)
 630                                 /* Strict in-order semantics */
 631                                 nilfs_set_opt(sbi, STRICT_ORDER);
 632                         else
 633                                 return 0;
 634                         break;
 635                 case Opt_err_panic:
 636                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 637                         break;
 638                 case Opt_err_ro:
 639                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 640                         break;
 641                 case Opt_err_cont:
 642                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 643                         break;
 644                 case Opt_snapshot:
 645                         if (match_int(&args[0], &option) || option <= 0)
 646                                 return 0;
 647                         if (is_remount) {
 648                                 if (!nilfs_test_opt(sbi, SNAPSHOT)) {
 649                                         printk(KERN_ERR
 650                                                "NILFS: cannot change regular "
 651                                                "mount to snapshot.\n");
 652                                         return 0;
 653                                 } else if (option != sbi->s_snapshot_cno) {
 654                                         printk(KERN_ERR
 655                                                "NILFS: cannot remount to a "
 656                                                "different snapshot.\n");
 657                                         return 0;
 658                                 }
 659                                 break;
 660                         }
 661                         if (!(sb->s_flags & MS_RDONLY)) {
 662                                 printk(KERN_ERR "NILFS: cannot mount snapshot "
 663                                        "read/write.  A read-only option is "
 664                                        "required.\n");
 665                                 return 0;
 666                         }
 667                         sbi->s_snapshot_cno = option;
 668                         nilfs_set_opt(sbi, SNAPSHOT);
 669                         break;
 670                 case Opt_norecovery:
 671                         nilfs_set_opt(sbi, NORECOVERY);
 672                         break;
 673                 case Opt_discard:
 674                         nilfs_set_opt(sbi, DISCARD);
 675                         break;
 676                 case Opt_nodiscard:
 677                         nilfs_clear_opt(sbi, DISCARD);
 678                         break;
 679                 default:
 680                         printk(KERN_ERR
 681                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 682                         return 0;
 683                 }
 684         }
 685         return 1;
 686 }
 687
 688 static inline void
 689 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 690                           struct nilfs_super_block *sbp)
 691 {
 692         sbi->s_mount_opt =
 693                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 694 }
 695
 696 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 697 {
 698         struct the_nilfs *nilfs = sbi->s_nilfs;
 699         struct nilfs_super_block **sbp;
 700         int max_mnt_count;
 701         int mnt_count;
 702
 703         /* nilfs->ns_sem must be locked by the caller. */
 704         sbp = nilfs_prepare_super(sbi, 0);
 705         if (!sbp)
 706                 return -EIO;
 707
 708         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 709         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 710
 711         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 712                 printk(KERN_WARNING
 713                        "NILFS warning: mounting fs with errors\n");
 714 #if 0
 715         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 716                 printk(KERN_WARNING
 717                        "NILFS warning: maximal mount count reached\n");
 718 #endif
 719         }
 720         if (!max_mnt_count)
 721                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 722
 723         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 724         sbp[0]->s_state =
 725                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 726         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 727         /* synchronize sbp[1] with sbp[0] */
 728         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 729         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 730 }
 731
 732 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 733                                                  u64 pos, int blocksize,
 734                                                  struct buffer_head **pbh)
 735 {
 736         unsigned long long sb_index = pos;
 737         unsigned long offset;
 738
 739         offset = do_div(sb_index, blocksize);
 740         *pbh = sb_bread(sb, sb_index);
 741         if (!*pbh)
 742                 return NULL;
 743         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 744 }
 745
 746 int nilfs_store_magic_and_option(struct super_block *sb,
 747                                  struct nilfs_super_block *sbp,
 748                                  char *data)
 749 {
 750         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 751
 752         sb->s_magic = le16_to_cpu(sbp->s_magic);
 753
 754         /* FS independent flags */
 755 #ifdef NILFS_ATIME_DISABLE
 756         sb->s_flags |= MS_NOATIME;
 757 #endif
 758
 759         nilfs_set_default_options(sbi, sbp);
 760
 761         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 762         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 763         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 764         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 765
 766         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 767 }
 768
 769 int nilfs_check_feature_compatibility(struct super_block *sb,
 770                                       struct nilfs_super_block *sbp)
 771 {
 772         __u64 features;
 773
 774         features = le64_to_cpu(sbp->s_feature_incompat) &
 775                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 776         if (features) {
 777                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 778                        "optional features (%llx)\n",
 779                        (unsigned long long)features);
 780                 return -EINVAL;
 781         }
 782         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 783                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 784         if (!(sb->s_flags & MS_RDONLY) && features) {
 785                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 786                        "unsupported optional features (%llx)\n",
 787                        (unsigned long long)features);
 788                 return -EINVAL;
 789         }
 790         return 0;
 791 }
 792
 793 /**
 794  * nilfs_fill_super() - initialize a super block instance
 795  * @sb: super_block
 796  * @data: mount options
 797  * @silent: silent mode flag
 798  * @nilfs: the_nilfs struct
 799  *
 800  * This function is called exclusively by nilfs->ns_mount_mutex.
 801  * So, the recovery process is protected from other simultaneous mounts.
 802  */
 803 static int
 804 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 805                  struct the_nilfs *nilfs)
 806 {
 807         struct nilfs_sb_info *sbi;
 808         struct inode *root;
 809         __u64 cno;
 810         int err;
 811
 812         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 813         if (!sbi)
 814                 return -ENOMEM;
 815
 816         sb->s_fs_info = sbi;
 817
 818         get_nilfs(nilfs);
 819         sbi->s_nilfs = nilfs;
 820         sbi->s_super = sb;
 821         atomic_set(&sbi->s_count, 1);
 822
 823         err = init_nilfs(nilfs, sbi, (char *)data);
 824         if (err)
 825                 goto failed_sbi;
 826
 827         spin_lock_init(&sbi->s_inode_lock);
 828         INIT_LIST_HEAD(&sbi->s_dirty_files);
 829         INIT_LIST_HEAD(&sbi->s_list);
 830
 831         /*
 832          * Following initialization is overlapped because
 833          * nilfs_sb_info structure has been cleared at the beginning.
 834          * But we reserve them to keep our interest and make ready
 835          * for the future change.
 836          */
 837         get_random_bytes(&sbi->s_next_generation,
 838                          sizeof(sbi->s_next_generation));
 839         spin_lock_init(&sbi->s_next_gen_lock);
 840
 841         sb->s_op = &nilfs_sops;
 842         sb->s_export_op = &nilfs_export_ops;
 843         sb->s_root = NULL;
 844         sb->s_time_gran = 1;
 845         sb->s_bdi = nilfs->ns_bdi;
 846
 847         err = load_nilfs(nilfs, sbi);
 848         if (err)
 849                 goto failed_sbi;
 850
 851         cno = nilfs_last_cno(nilfs);
 852
 853         if (sb->s_flags & MS_RDONLY) {
 854                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 855                         down_read(&nilfs->ns_segctor_sem);
 856                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
 857                                                        sbi->s_snapshot_cno);
 858                         up_read(&nilfs->ns_segctor_sem);
 859                         if (err < 0) {
 860                                 if (err == -ENOENT)
 861                                         err = -EINVAL;
 862                                 goto failed_sbi;
 863                         }
 864                         if (!err) {
 865                                 printk(KERN_ERR
 866                                        "NILFS: The specified checkpoint is "
 867                                        "not a snapshot "
 868                                        "(checkpoint number=%llu).\n",
 869                                        (unsigned long long)sbi->s_snapshot_cno);
 870                                 err = -EINVAL;
 871                                 goto failed_sbi;
 872                         }
 873                         cno = sbi->s_snapshot_cno;
 874                 }
 875         }
 876
 877         err = nilfs_attach_checkpoint(sbi, cno);
 878         if (err) {
 879                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 880                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 881                 goto failed_sbi;
 882         }
 883
 884         if (!(sb->s_flags & MS_RDONLY)) {
 885                 err = nilfs_attach_segment_constructor(sbi);
 886                 if (err)
 887                         goto failed_checkpoint;
 888         }
 889
 890         root = nilfs_iget(sb, NILFS_ROOT_INO);
 891         if (IS_ERR(root)) {
 892                 printk(KERN_ERR "NILFS: get root inode failed\n");
 893                 err = PTR_ERR(root);
 894                 goto failed_segctor;
 895         }
 896         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 897                 iput(root);
 898                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 899                 err = -EINVAL;
 900                 goto failed_segctor;
 901         }
 902         sb->s_root = d_alloc_root(root);
 903         if (!sb->s_root) {
 904                 iput(root);
 905                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 906                 err = -ENOMEM;
 907                 goto failed_segctor;
 908         }
 909
 910         if (!(sb->s_flags & MS_RDONLY)) {
 911                 down_write(&nilfs->ns_sem);
 912                 nilfs_setup_super(sbi);
 913                 up_write(&nilfs->ns_sem);
 914         }
 915
 916         down_write(&nilfs->ns_super_sem);
 917         if (!nilfs_test_opt(sbi, SNAPSHOT))
 918                 nilfs->ns_current = sbi;
 919         up_write(&nilfs->ns_super_sem);
 920
 921         return 0;
 922
 923  failed_segctor:
 924         nilfs_detach_segment_constructor(sbi);
 925
 926  failed_checkpoint:
 927         nilfs_detach_checkpoint(sbi);
 928
 929  failed_sbi:
 930         put_nilfs(nilfs);
 931         sb->s_fs_info = NULL;
 932         nilfs_put_sbinfo(sbi);
 933         return err;
 934 }
 935
 936 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 937 {
 938         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 939         struct the_nilfs *nilfs = sbi->s_nilfs;
 940         unsigned long old_sb_flags;
 941         struct nilfs_mount_options old_opts;
 942         int was_snapshot, err;
 943
 944         lock_kernel();
 945
 946         down_write(&nilfs->ns_super_sem);
 947         old_sb_flags = sb->s_flags;
 948         old_opts.mount_opt = sbi->s_mount_opt;
 949         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 950         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 951
 952         if (!parse_options(data, sb, 1)) {
 953                 err = -EINVAL;
 954                 goto restore_opts;
 955         }
 956         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 957
 958         err = -EINVAL;
 959         if (was_snapshot && !(*flags & MS_RDONLY)) {
 960                 printk(KERN_ERR "NILFS (device %s): cannot remount snapshot "
 961                        "read/write.\n", sb->s_id);
 962                 goto restore_opts;
 963         }
 964
 965         if (!nilfs_valid_fs(nilfs)) {
 966                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 967                        "remount because the filesystem is in an "
 968                        "incomplete recovery state.\n", sb->s_id);
 969                 goto restore_opts;
 970         }
 971
 972         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 973                 goto out;
 974         if (*flags & MS_RDONLY) {
 975                 /* Shutting down the segment constructor */
 976                 nilfs_detach_segment_constructor(sbi);
 977                 sb->s_flags |= MS_RDONLY;
 978
 979                 /*
 980                  * Remounting a valid RW partition RDONLY, so set
 981                  * the RDONLY flag and then mark the partition as valid again.
 982                  */
 983                 down_write(&nilfs->ns_sem);
 984                 nilfs_cleanup_super(sbi);
 985                 up_write(&nilfs->ns_sem);
 986         } else {
 987                 __u64 features;
 988
 989                 /*
 990                  * Mounting a RDONLY partition read-write, so reread and
 991                  * store the current valid flag.  (It may have been changed
 992                  * by fsck since we originally mounted the partition.)
 993                  */
 994                 down_read(&nilfs->ns_sem);
 995                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
 996                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
 997                 up_read(&nilfs->ns_sem);
 998                 if (features) {
 999                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1000                                "remount RDWR because of unsupported optional "
1001                                "features (%llx)\n",
1002                                sb->s_id, (unsigned long long)features);
1003                         err = -EROFS;
1004                         goto restore_opts;
1005                 }
1006
1007                 sb->s_flags &= ~MS_RDONLY;
1008
1009                 err = nilfs_attach_segment_constructor(sbi);
1010                 if (err)
1011                         goto restore_opts;
1012
1013                 down_write(&nilfs->ns_sem);
1014                 nilfs_setup_super(sbi);
1015                 up_write(&nilfs->ns_sem);
1016         }
1017  out:
1018         up_write(&nilfs->ns_super_sem);
1019         unlock_kernel();
1020         return 0;
1021
1022  restore_opts:
1023         sb->s_flags = old_sb_flags;
1024         sbi->s_mount_opt = old_opts.mount_opt;
1025         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1026         up_write(&nilfs->ns_super_sem);
1027         unlock_kernel();
1028         return err;
1029 }
1030
1031 struct nilfs_super_data {
1032         struct block_device *bdev;
1033         struct nilfs_sb_info *sbi;
1034         __u64 cno;
1035         int flags;
1036 };
1037
1038 /**
1039  * nilfs_identify - pre-read mount options needed to identify mount instance
1040  * @data: mount options
1041  * @sd: nilfs_super_data
1042  */
1043 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1044 {
1045         char *p, *options = data;
1046         substring_t args[MAX_OPT_ARGS];
1047         int option, token;
1048         int ret = 0;
1049
1050         do {
1051                 p = strsep(&options, ",");
1052                 if (p != NULL && *p) {
1053                         token = match_token(p, tokens, args);
1054                         if (token == Opt_snapshot) {
1055                                 if (!(sd->flags & MS_RDONLY))
1056                                         ret++;
1057                                 else {
1058                                         ret = match_int(&args[0], &option);
1059                                         if (!ret) {
1060                                                 if (option > 0)
1061                                                         sd->cno = option;
1062                                                 else
1063                                                         ret++;
1064                                         }
1065                                 }
1066                         }
1067                         if (ret)
1068                                 printk(KERN_ERR
1069                                        "NILFS: invalid mount option: %s\n", p);
1070                 }
1071                 if (!options)
1072                         break;
1073                 BUG_ON(options == data);
1074                 *(options - 1) = ',';
1075         } while (!ret);
1076         return ret;
1077 }
1078
1079 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1080 {
1081         struct nilfs_super_data *sd = data;
1082
1083         s->s_bdev = sd->bdev;
1084         s->s_dev = s->s_bdev->bd_dev;
1085         return 0;
1086 }
1087
1088 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1089 {
1090         struct nilfs_super_data *sd = data;
1091
1092         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1093 }
1094
1095 static int
1096 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1097              const char *dev_name, void *data, struct vfsmount *mnt)
1098 {
1099         struct nilfs_super_data sd;
1100         struct super_block *s;
1101         fmode_t mode = FMODE_READ;
1102         struct the_nilfs *nilfs;
1103         int err, need_to_close = 1;
1104
1105         if (!(flags & MS_RDONLY))
1106                 mode |= FMODE_WRITE;
1107
1108         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1109         if (IS_ERR(sd.bdev))
1110                 return PTR_ERR(sd.bdev);
1111
1112         /*
1113          * To get mount instance using sget() vfs-routine, NILFS needs
1114          * much more information than normal filesystems to identify mount
1115          * instance.  For snapshot mounts, not only a mount type (ro-mount
1116          * or rw-mount) but also a checkpoint number is required.
1117          */
1118         sd.cno = 0;
1119         sd.flags = flags;
1120         if (nilfs_identify((char *)data, &sd)) {
1121                 err = -EINVAL;
1122                 goto failed;
1123         }
1124
1125         nilfs = find_or_create_nilfs(sd.bdev);
1126         if (!nilfs) {
1127                 err = -ENOMEM;
1128                 goto failed;
1129         }
1130
1131         mutex_lock(&nilfs->ns_mount_mutex);
1132
1133         if (!sd.cno) {
1134                 /*
1135                  * Check if an exclusive mount exists or not.
1136                  * Snapshot mounts coexist with a current mount
1137                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1138                  * ro-mount are mutually exclusive.
1139                  */
1140                 down_read(&nilfs->ns_super_sem);
1141                 if (nilfs->ns_current &&
1142                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1143                      & MS_RDONLY)) {
1144                         up_read(&nilfs->ns_super_sem);
1145                         err = -EBUSY;
1146                         goto failed_unlock;
1147                 }
1148                 up_read(&nilfs->ns_super_sem);
1149         }
1150
1151         /*
1152          * Find existing nilfs_sb_info struct
1153          */
1154         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1155
1156         /*
1157          * Get super block instance holding the nilfs_sb_info struct.
1158          * A new instance is allocated if no existing mount is present or
1159          * existing instance has been unmounted.
1160          */
1161         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1162         if (sd.sbi)
1163                 nilfs_put_sbinfo(sd.sbi);
1164
1165         if (IS_ERR(s)) {
1166                 err = PTR_ERR(s);
1167                 goto failed_unlock;
1168         }
1169
1170         if (!s->s_root) {
1171                 char b[BDEVNAME_SIZE];
1172
1173                 /* New superblock instance created */
1174                 s->s_flags = flags;
1175                 s->s_mode = mode;
1176                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1177                 sb_set_blocksize(s, block_size(sd.bdev));
1178
1179                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1180                                        nilfs);
1181                 if (err)
1182                         goto cancel_new;
1183
1184                 s->s_flags |= MS_ACTIVE;
1185                 need_to_close = 0;
1186         }
1187
1188         mutex_unlock(&nilfs->ns_mount_mutex);
1189         put_nilfs(nilfs);
1190         if (need_to_close)
1191                 close_bdev_exclusive(sd.bdev, mode);
1192         simple_set_mnt(mnt, s);
1193         return 0;
1194
1195  failed_unlock:
1196         mutex_unlock(&nilfs->ns_mount_mutex);
1197         put_nilfs(nilfs);
1198  failed:
1199         close_bdev_exclusive(sd.bdev, mode);
1200
1201         return err;
1202
1203  cancel_new:
1204         /* Abandoning the newly allocated superblock */
1205         mutex_unlock(&nilfs->ns_mount_mutex);
1206         put_nilfs(nilfs);
1207         deactivate_locked_super(s);
1208         /*
1209          * deactivate_locked_super() invokes close_bdev_exclusive().
1210          * We must finish all post-cleaning before this call;
1211          * put_nilfs() needs the block device.
1212          */
1213         return err;
1214 }
1215
1216 struct file_system_type nilfs_fs_type = {
1217         .owner    = THIS_MODULE,
1218         .name     = "nilfs2",
1219         .get_sb   = nilfs_get_sb,
1220         .kill_sb  = kill_block_super,
1221         .fs_flags = FS_REQUIRES_DEV,
1222 };
1223
1224 static void nilfs_inode_init_once(void *obj)
1225 {
1226         struct nilfs_inode_info *ii = obj;
1227
1228         INIT_LIST_HEAD(&ii->i_dirty);
1229 #ifdef CONFIG_NILFS_XATTR
1230         init_rwsem(&ii->xattr_sem);
1231 #endif
1232         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1233         ii->i_bmap = &ii->i_bmap_data;
1234         inode_init_once(&ii->vfs_inode);
1235 }
1236
1237 static void nilfs_segbuf_init_once(void *obj)
1238 {
1239         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1240 }
1241
1242 static void nilfs_destroy_cachep(void)
1243 {
1244         if (nilfs_inode_cachep)
1245                 kmem_cache_destroy(nilfs_inode_cachep);
1246         if (nilfs_transaction_cachep)
1247                 kmem_cache_destroy(nilfs_transaction_cachep);
1248         if (nilfs_segbuf_cachep)
1249                 kmem_cache_destroy(nilfs_segbuf_cachep);
1250         if (nilfs_btree_path_cache)
1251                 kmem_cache_destroy(nilfs_btree_path_cache);
1252 }
1253
1254 static int __init nilfs_init_cachep(void)
1255 {
1256         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1257                         sizeof(struct nilfs_inode_info), 0,
1258                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1259         if (!nilfs_inode_cachep)
1260                 goto fail;
1261
1262         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1263                         sizeof(struct nilfs_transaction_info), 0,
1264                         SLAB_RECLAIM_ACCOUNT, NULL);
1265         if (!nilfs_transaction_cachep)
1266                 goto fail;
1267
1268         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1269                         sizeof(struct nilfs_segment_buffer), 0,
1270                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1271         if (!nilfs_segbuf_cachep)
1272                 goto fail;
1273
1274         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1275                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1276                         0, 0, NULL);
1277         if (!nilfs_btree_path_cache)
1278                 goto fail;
1279
1280         return 0;
1281
1282 fail:
1283         nilfs_destroy_cachep();
1284         return -ENOMEM;
1285 }
1286
1287 static int __init init_nilfs_fs(void)
1288 {
1289         int err;
1290
1291         err = nilfs_init_cachep();
1292         if (err)
1293                 goto fail;
1294
1295         err = register_filesystem(&nilfs_fs_type);
1296         if (err)
1297                 goto free_cachep;
1298
1299         printk(KERN_INFO "NILFS version 2 loaded\n");
1300         return 0;
1301
1302 free_cachep:
1303         nilfs_destroy_cachep();
1304 fail:
1305         return err;
1306 }
1307
1308 static void __exit exit_nilfs_fs(void)
1309 {
1310         nilfs_destroy_cachep();
1311         unregister_filesystem(&nilfs_fs_type);
1312 }
1313
1314 module_init(init_nilfs_fs)
1315 module_exit(exit_nilfs_fs)