fs/nilfs2/super.c

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