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