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 static 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_setup_super(struct nilfs_sb_info *sbi, int is_mount);
  77 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  78
  79 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  80 {
  81         struct the_nilfs *nilfs = sbi->s_nilfs;
  82         struct nilfs_super_block **sbp;
  83
  84         down_write(&nilfs->ns_sem);
  85         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  86                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  87                 sbp = nilfs_prepare_super(sbi, 0);
  88                 if (likely(sbp)) {
  89                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  90                         if (sbp[1])
  91                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  92                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  93                 }
  94         }
  95         up_write(&nilfs->ns_sem);
  96 }
  97
  98 /**
  99  * nilfs_error() - report failure condition on a filesystem
 100  *
 101  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 102  * reporting an error message.  It should be called when NILFS detects
 103  * incoherences or defects of meta data on disk.  As for sustainable
 104  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 105  * function should be used instead.
 106  *
 107  * The segment constructor must not call this function because it can
 108  * kill itself.
 109  */
 110 void nilfs_error(struct super_block *sb, const char *function,
 111                  const char *fmt, ...)
 112 {
 113         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 114         va_list args;
 115
 116         va_start(args, fmt);
 117         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 118         vprintk(fmt, args);
 119         printk("\n");
 120         va_end(args);
 121
 122         if (!(sb->s_flags & MS_RDONLY)) {
 123                 nilfs_set_error(sbi);
 124
 125                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 126                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 127                         sb->s_flags |= MS_RDONLY;
 128                 }
 129         }
 130
 131         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 132                 panic("NILFS (device %s): panic forced after error\n",
 133                       sb->s_id);
 134 }
 135
 136 void nilfs_warning(struct super_block *sb, const char *function,
 137                    const char *fmt, ...)
 138 {
 139         va_list args;
 140
 141         va_start(args, fmt);
 142         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 143                sb->s_id, function);
 144         vprintk(fmt, args);
 145         printk("\n");
 146         va_end(args);
 147 }
 148
 149
 150 struct inode *nilfs_alloc_inode(struct super_block *sb)
 151 {
 152         struct nilfs_inode_info *ii;
 153
 154         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 155         if (!ii)
 156                 return NULL;
 157         ii->i_bh = NULL;
 158         ii->i_state = 0;
 159         ii->i_cno = 0;
 160         ii->vfs_inode.i_version = 1;
 161         nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
 162         return &ii->vfs_inode;
 163 }
 164
 165 void nilfs_destroy_inode(struct inode *inode)
 166 {
 167         struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 168
 169         if (mdi) {
 170                 kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 171                 kfree(mdi);
 172         }
 173         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 174 }
 175
 176 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 177 {
 178         struct the_nilfs *nilfs = sbi->s_nilfs;
 179         int err;
 180
 181  retry:
 182         set_buffer_dirty(nilfs->ns_sbh[0]);
 183         if (nilfs_test_opt(sbi, BARRIER)) {
 184                 err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 185                                           WRITE_SYNC | WRITE_FLUSH_FUA);
 186         } else {
 187                 err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 188         }
 189
 190         if (unlikely(err)) {
 191                 printk(KERN_ERR
 192                        "NILFS: unable to write superblock (err=%d)\n", err);
 193                 if (err == -EIO && nilfs->ns_sbh[1]) {
 194                         /*
 195                          * sbp[0] points to newer log than sbp[1],
 196                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 197                          */
 198                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 199                                nilfs->ns_sbsize);
 200                         nilfs_fall_back_super_block(nilfs);
 201                         goto retry;
 202                 }
 203         } else {
 204                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 205
 206                 nilfs->ns_sbwcount++;
 207
 208                 /*
 209                  * The latest segment becomes trailable from the position
 210                  * written in superblock.
 211                  */
 212                 clear_nilfs_discontinued(nilfs);
 213
 214                 /* update GC protection for recent segments */
 215                 if (nilfs->ns_sbh[1]) {
 216                         if (flag == NILFS_SB_COMMIT_ALL) {
 217                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 218                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 219                                         goto out;
 220                         }
 221                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 222                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 223                                 sbp = nilfs->ns_sbp[1];
 224                 }
 225
 226                 spin_lock(&nilfs->ns_last_segment_lock);
 227                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 228                 spin_unlock(&nilfs->ns_last_segment_lock);
 229         }
 230  out:
 231         return err;
 232 }
 233
 234 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 235                           struct the_nilfs *nilfs)
 236 {
 237         sector_t nfreeblocks;
 238
 239         /* nilfs->ns_sem must be locked by the caller. */
 240         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 241         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 242
 243         spin_lock(&nilfs->ns_last_segment_lock);
 244         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 245         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 246         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 247         spin_unlock(&nilfs->ns_last_segment_lock);
 248 }
 249
 250 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 251                                                int flip)
 252 {
 253         struct the_nilfs *nilfs = sbi->s_nilfs;
 254         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 255
 256         /* nilfs->ns_sem must be locked by the caller. */
 257         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 258                 if (sbp[1] &&
 259                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 260                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 261                 } else {
 262                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 263                                sbi->s_super->s_id);
 264                         return NULL;
 265                 }
 266         } else if (sbp[1] &&
 267                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 268                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 269         }
 270
 271         if (flip && sbp[1])
 272                 nilfs_swap_super_block(nilfs);
 273
 274         return sbp;
 275 }
 276
 277 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 278 {
 279         struct the_nilfs *nilfs = sbi->s_nilfs;
 280         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 281         time_t t;
 282
 283         /* nilfs->ns_sem must be locked by the caller. */
 284         t = get_seconds();
 285         nilfs->ns_sbwtime = t;
 286         sbp[0]->s_wtime = cpu_to_le64(t);
 287         sbp[0]->s_sum = 0;
 288         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 289                                              (unsigned char *)sbp[0],
 290                                              nilfs->ns_sbsize));
 291         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 292                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 293                 sbp[1]->s_sum = 0;
 294                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 295                                             (unsigned char *)sbp[1],
 296                                             nilfs->ns_sbsize));
 297         }
 298         clear_nilfs_sb_dirty(nilfs);
 299         return nilfs_sync_super(sbi, flag);
 300 }
 301
 302 /**
 303  * nilfs_cleanup_super() - write filesystem state for cleanup
 304  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 305  *
 306  * This function restores state flags in the on-disk super block.
 307  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 308  * filesystem was not clean previously.
 309  */
 310 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 311 {
 312         struct nilfs_super_block **sbp;
 313         int flag = NILFS_SB_COMMIT;
 314         int ret = -EIO;
 315
 316         sbp = nilfs_prepare_super(sbi, 0);
 317         if (sbp) {
 318                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 319                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 320                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 321                         /*
 322                          * make the "clean" flag also to the opposite
 323                          * super block if both super blocks point to
 324                          * the same checkpoint.
 325                          */
 326                         sbp[1]->s_state = sbp[0]->s_state;
 327                         flag = NILFS_SB_COMMIT_ALL;
 328                 }
 329                 ret = nilfs_commit_super(sbi, flag);
 330         }
 331         return ret;
 332 }
 333
 334 static void nilfs_put_super(struct super_block *sb)
 335 {
 336         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 337         struct the_nilfs *nilfs = sbi->s_nilfs;
 338
 339         nilfs_detach_segment_constructor(sbi);
 340
 341         if (!(sb->s_flags & MS_RDONLY)) {
 342                 down_write(&nilfs->ns_sem);
 343                 nilfs_cleanup_super(sbi);
 344                 up_write(&nilfs->ns_sem);
 345         }
 346
 347         iput(nilfs->ns_sufile);
 348         iput(nilfs->ns_cpfile);
 349         iput(nilfs->ns_dat);
 350
 351         destroy_nilfs(nilfs);
 352         sbi->s_super = NULL;
 353         sb->s_fs_info = NULL;
 354         kfree(sbi);
 355 }
 356
 357 static int nilfs_sync_fs(struct super_block *sb, int wait)
 358 {
 359         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 360         struct the_nilfs *nilfs = sbi->s_nilfs;
 361         struct nilfs_super_block **sbp;
 362         int err = 0;
 363
 364         /* This function is called when super block should be written back */
 365         if (wait)
 366                 err = nilfs_construct_segment(sb);
 367
 368         down_write(&nilfs->ns_sem);
 369         if (nilfs_sb_dirty(nilfs)) {
 370                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 371                 if (likely(sbp)) {
 372                         nilfs_set_log_cursor(sbp[0], nilfs);
 373                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 374                 }
 375         }
 376         up_write(&nilfs->ns_sem);
 377
 378         return err;
 379 }
 380
 381 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 382                             struct nilfs_root **rootp)
 383 {
 384         struct the_nilfs *nilfs = sbi->s_nilfs;
 385         struct nilfs_root *root;
 386         struct nilfs_checkpoint *raw_cp;
 387         struct buffer_head *bh_cp;
 388         int err = -ENOMEM;
 389
 390         root = nilfs_find_or_create_root(
 391                 nilfs, curr_mnt ? NILFS_CPTREE_CURRENT_CNO : cno);
 392         if (!root)
 393                 return err;
 394
 395         if (root->ifile)
 396                 goto reuse; /* already attached checkpoint */
 397
 398         down_read(&nilfs->ns_segctor_sem);
 399         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 400                                           &bh_cp);
 401         up_read(&nilfs->ns_segctor_sem);
 402         if (unlikely(err)) {
 403                 if (err == -ENOENT || err == -EINVAL) {
 404                         printk(KERN_ERR
 405                                "NILFS: Invalid checkpoint "
 406                                "(checkpoint number=%llu)\n",
 407                                (unsigned long long)cno);
 408                         err = -EINVAL;
 409                 }
 410                 goto failed;
 411         }
 412
 413         err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size,
 414                                &raw_cp->cp_ifile_inode, &root->ifile);
 415         if (err)
 416                 goto failed_bh;
 417
 418         atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 419         atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 420
 421         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 422
 423  reuse:
 424         *rootp = root;
 425         return 0;
 426
 427  failed_bh:
 428         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 429  failed:
 430         nilfs_put_root(root);
 431
 432         return err;
 433 }
 434
 435 static int nilfs_freeze(struct super_block *sb)
 436 {
 437         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 438         struct the_nilfs *nilfs = sbi->s_nilfs;
 439         int err;
 440
 441         if (sb->s_flags & MS_RDONLY)
 442                 return 0;
 443
 444         /* Mark super block clean */
 445         down_write(&nilfs->ns_sem);
 446         err = nilfs_cleanup_super(sbi);
 447         up_write(&nilfs->ns_sem);
 448         return err;
 449 }
 450
 451 static int nilfs_unfreeze(struct super_block *sb)
 452 {
 453         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 454         struct the_nilfs *nilfs = sbi->s_nilfs;
 455
 456         if (sb->s_flags & MS_RDONLY)
 457                 return 0;
 458
 459         down_write(&nilfs->ns_sem);
 460         nilfs_setup_super(sbi, false);
 461         up_write(&nilfs->ns_sem);
 462         return 0;
 463 }
 464
 465 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 466 {
 467         struct super_block *sb = dentry->d_sb;
 468         struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
 469         struct the_nilfs *nilfs = root->nilfs;
 470         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 471         unsigned long long blocks;
 472         unsigned long overhead;
 473         unsigned long nrsvblocks;
 474         sector_t nfreeblocks;
 475         int err;
 476
 477         /*
 478          * Compute all of the segment blocks
 479          *
 480          * The blocks before first segment and after last segment
 481          * are excluded.
 482          */
 483         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 484                 - nilfs->ns_first_data_block;
 485         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 486
 487         /*
 488          * Compute the overhead
 489          *
 490          * When distributing meta data blocks outside segment structure,
 491          * We must count them as the overhead.
 492          */
 493         overhead = 0;
 494
 495         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 496         if (unlikely(err))
 497                 return err;
 498
 499         buf->f_type = NILFS_SUPER_MAGIC;
 500         buf->f_bsize = sb->s_blocksize;
 501         buf->f_blocks = blocks - overhead;
 502         buf->f_bfree = nfreeblocks;
 503         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 504                 (buf->f_bfree - nrsvblocks) : 0;
 505         buf->f_files = atomic_read(&root->inodes_count);
 506         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 507         buf->f_namelen = NILFS_NAME_LEN;
 508         buf->f_fsid.val[0] = (u32)id;
 509         buf->f_fsid.val[1] = (u32)(id >> 32);
 510
 511         return 0;
 512 }
 513
 514 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 515 {
 516         struct super_block *sb = vfs->mnt_sb;
 517         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 518         struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
 519
 520         if (!nilfs_test_opt(sbi, BARRIER))
 521                 seq_puts(seq, ",nobarrier");
 522         if (root->cno != NILFS_CPTREE_CURRENT_CNO)
 523                 seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
 524         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 525                 seq_puts(seq, ",errors=panic");
 526         if (nilfs_test_opt(sbi, ERRORS_CONT))
 527                 seq_puts(seq, ",errors=continue");
 528         if (nilfs_test_opt(sbi, STRICT_ORDER))
 529                 seq_puts(seq, ",order=strict");
 530         if (nilfs_test_opt(sbi, NORECOVERY))
 531                 seq_puts(seq, ",norecovery");
 532         if (nilfs_test_opt(sbi, DISCARD))
 533                 seq_puts(seq, ",discard");
 534
 535         return 0;
 536 }
 537
 538 static const struct super_operations nilfs_sops = {
 539         .alloc_inode    = nilfs_alloc_inode,
 540         .destroy_inode  = nilfs_destroy_inode,
 541         .dirty_inode    = nilfs_dirty_inode,
 542         /* .write_inode    = nilfs_write_inode, */
 543         /* .put_inode      = nilfs_put_inode, */
 544         /* .drop_inode    = nilfs_drop_inode, */
 545         .evict_inode    = nilfs_evict_inode,
 546         .put_super      = nilfs_put_super,
 547         /* .write_super    = nilfs_write_super, */
 548         .sync_fs        = nilfs_sync_fs,
 549         .freeze_fs      = nilfs_freeze,
 550         .unfreeze_fs    = nilfs_unfreeze,
 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
 585         if (!options)
 586                 return 1;
 587
 588         while ((p = strsep(&options, ",")) != NULL) {
 589                 int token;
 590                 if (!*p)
 591                         continue;
 592
 593                 token = match_token(p, tokens, args);
 594                 switch (token) {
 595                 case Opt_barrier:
 596                         nilfs_set_opt(sbi, BARRIER);
 597                         break;
 598                 case Opt_nobarrier:
 599                         nilfs_clear_opt(sbi, BARRIER);
 600                         break;
 601                 case Opt_order:
 602                         if (strcmp(args[0].from, "relaxed") == 0)
 603                                 /* Ordered data semantics */
 604                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 605                         else if (strcmp(args[0].from, "strict") == 0)
 606                                 /* Strict in-order semantics */
 607                                 nilfs_set_opt(sbi, STRICT_ORDER);
 608                         else
 609                                 return 0;
 610                         break;
 611                 case Opt_err_panic:
 612                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 613                         break;
 614                 case Opt_err_ro:
 615                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 616                         break;
 617                 case Opt_err_cont:
 618                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 619                         break;
 620                 case Opt_snapshot:
 621                         if (is_remount) {
 622                                 printk(KERN_ERR
 623                                        "NILFS: \"%s\" option is invalid "
 624                                        "for remount.\n", p);
 625                                 return 0;
 626                         }
 627                         break;
 628                 case Opt_norecovery:
 629                         nilfs_set_opt(sbi, NORECOVERY);
 630                         break;
 631                 case Opt_discard:
 632                         nilfs_set_opt(sbi, DISCARD);
 633                         break;
 634                 case Opt_nodiscard:
 635                         nilfs_clear_opt(sbi, DISCARD);
 636                         break;
 637                 default:
 638                         printk(KERN_ERR
 639                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 640                         return 0;
 641                 }
 642         }
 643         return 1;
 644 }
 645
 646 static inline void
 647 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 648                           struct nilfs_super_block *sbp)
 649 {
 650         sbi->s_mount_opt =
 651                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 652 }
 653
 654 static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount)
 655 {
 656         struct the_nilfs *nilfs = sbi->s_nilfs;
 657         struct nilfs_super_block **sbp;
 658         int max_mnt_count;
 659         int mnt_count;
 660
 661         /* nilfs->ns_sem must be locked by the caller. */
 662         sbp = nilfs_prepare_super(sbi, 0);
 663         if (!sbp)
 664                 return -EIO;
 665
 666         if (!is_mount)
 667                 goto skip_mount_setup;
 668
 669         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 670         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 671
 672         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 673                 printk(KERN_WARNING
 674                        "NILFS warning: mounting fs with errors\n");
 675 #if 0
 676         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 677                 printk(KERN_WARNING
 678                        "NILFS warning: maximal mount count reached\n");
 679 #endif
 680         }
 681         if (!max_mnt_count)
 682                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 683
 684         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 685         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 686
 687 skip_mount_setup:
 688         sbp[0]->s_state =
 689                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 690         /* synchronize sbp[1] with sbp[0] */
 691         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 692         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 693 }
 694
 695 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 696                                                  u64 pos, int blocksize,
 697                                                  struct buffer_head **pbh)
 698 {
 699         unsigned long long sb_index = pos;
 700         unsigned long offset;
 701
 702         offset = do_div(sb_index, blocksize);
 703         *pbh = sb_bread(sb, sb_index);
 704         if (!*pbh)
 705                 return NULL;
 706         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 707 }
 708
 709 int nilfs_store_magic_and_option(struct super_block *sb,
 710                                  struct nilfs_super_block *sbp,
 711                                  char *data)
 712 {
 713         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 714
 715         sb->s_magic = le16_to_cpu(sbp->s_magic);
 716
 717         /* FS independent flags */
 718 #ifdef NILFS_ATIME_DISABLE
 719         sb->s_flags |= MS_NOATIME;
 720 #endif
 721
 722         nilfs_set_default_options(sbi, sbp);
 723
 724         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 725         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 726         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 727         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 728
 729         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 730 }
 731
 732 int nilfs_check_feature_compatibility(struct super_block *sb,
 733                                       struct nilfs_super_block *sbp)
 734 {
 735         __u64 features;
 736
 737         features = le64_to_cpu(sbp->s_feature_incompat) &
 738                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 739         if (features) {
 740                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 741                        "optional features (%llx)\n",
 742                        (unsigned long long)features);
 743                 return -EINVAL;
 744         }
 745         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 746                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 747         if (!(sb->s_flags & MS_RDONLY) && features) {
 748                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 749                        "unsupported optional features (%llx)\n",
 750                        (unsigned long long)features);
 751                 return -EINVAL;
 752         }
 753         return 0;
 754 }
 755
 756 static int nilfs_get_root_dentry(struct super_block *sb,
 757                                  struct nilfs_root *root,
 758                                  struct dentry **root_dentry)
 759 {
 760         struct inode *inode;
 761         struct dentry *dentry;
 762         int ret = 0;
 763
 764         inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
 765         if (IS_ERR(inode)) {
 766                 printk(KERN_ERR "NILFS: get root inode failed\n");
 767                 ret = PTR_ERR(inode);
 768                 goto out;
 769         }
 770         if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
 771                 iput(inode);
 772                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 773                 ret = -EINVAL;
 774                 goto out;
 775         }
 776
 777         if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
 778                 dentry = d_find_alias(inode);
 779                 if (!dentry) {
 780                         dentry = d_alloc_root(inode);
 781                         if (!dentry) {
 782                                 iput(inode);
 783                                 ret = -ENOMEM;
 784                                 goto failed_dentry;
 785                         }
 786                 } else {
 787                         iput(inode);
 788                 }
 789         } else {
 790                 dentry = d_obtain_alias(inode);
 791                 if (IS_ERR(dentry)) {
 792                         ret = PTR_ERR(dentry);
 793                         goto failed_dentry;
 794                 }
 795         }
 796         *root_dentry = dentry;
 797  out:
 798         return ret;
 799
 800  failed_dentry:
 801         printk(KERN_ERR "NILFS: get root dentry failed\n");
 802         goto out;
 803 }
 804
 805 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 806                                  struct dentry **root_dentry)
 807 {
 808         struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
 809         struct nilfs_root *root;
 810         int ret;
 811
 812         down_read(&nilfs->ns_segctor_sem);
 813         ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
 814         up_read(&nilfs->ns_segctor_sem);
 815         if (ret < 0) {
 816                 ret = (ret == -ENOENT) ? -EINVAL : ret;
 817                 goto out;
 818         } else if (!ret) {
 819                 printk(KERN_ERR "NILFS: The specified checkpoint is "
 820                        "not a snapshot (checkpoint number=%llu).\n",
 821                        (unsigned long long)cno);
 822                 ret = -EINVAL;
 823                 goto out;
 824         }
 825
 826         ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
 827         if (ret) {
 828                 printk(KERN_ERR "NILFS: error loading snapshot "
 829                        "(checkpoint number=%llu).\n",
 830                (unsigned long long)cno);
 831                 goto out;
 832         }
 833         ret = nilfs_get_root_dentry(s, root, root_dentry);
 834         nilfs_put_root(root);
 835  out:
 836         return ret;
 837 }
 838
 839 static int nilfs_tree_was_touched(struct dentry *root_dentry)
 840 {
 841         return atomic_read(&root_dentry->d_count) > 1;
 842 }
 843
 844 /**
 845  * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
 846  * @root_dentry: root dentry of the tree to be shrunk
 847  *
 848  * This function returns true if the tree was in-use.
 849  */
 850 static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
 851 {
 852         if (have_submounts(root_dentry))
 853                 return true;
 854         shrink_dcache_parent(root_dentry);
 855         return nilfs_tree_was_touched(root_dentry);
 856 }
 857
 858 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
 859 {
 860         struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
 861         struct nilfs_root *root;
 862         struct inode *inode;
 863         struct dentry *dentry;
 864         int ret;
 865
 866         if (cno < 0 || cno > nilfs->ns_cno)
 867                 return false;
 868
 869         if (cno >= nilfs_last_cno(nilfs))
 870                 return true;    /* protect recent checkpoints */
 871
 872         ret = false;
 873         root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
 874         if (root) {
 875                 inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
 876                 if (inode) {
 877                         dentry = d_find_alias(inode);
 878                         if (dentry) {
 879                                 if (nilfs_tree_was_touched(dentry))
 880                                         ret = nilfs_try_to_shrink_tree(dentry);
 881                                 dput(dentry);
 882                         }
 883                         iput(inode);
 884                 }
 885                 nilfs_put_root(root);
 886         }
 887         return ret;
 888 }
 889
 890 /**
 891  * nilfs_fill_super() - initialize a super block instance
 892  * @sb: super_block
 893  * @data: mount options
 894  * @silent: silent mode flag
 895  *
 896  * This function is called exclusively by nilfs->ns_mount_mutex.
 897  * So, the recovery process is protected from other simultaneous mounts.
 898  */
 899 static int
 900 nilfs_fill_super(struct super_block *sb, void *data, int silent)
 901 {
 902         struct the_nilfs *nilfs;
 903         struct nilfs_sb_info *sbi;
 904         struct nilfs_root *fsroot;
 905         struct backing_dev_info *bdi;
 906         __u64 cno;
 907         int err;
 908
 909         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 910         if (!sbi)
 911                 return -ENOMEM;
 912
 913         sb->s_fs_info = sbi;
 914         sbi->s_super = sb;
 915
 916         nilfs = alloc_nilfs(sb->s_bdev);
 917         if (!nilfs) {
 918                 err = -ENOMEM;
 919                 goto failed_sbi;
 920         }
 921         sbi->s_nilfs = nilfs;
 922
 923         err = init_nilfs(nilfs, sbi, (char *)data);
 924         if (err)
 925                 goto failed_nilfs;
 926
 927         spin_lock_init(&sbi->s_inode_lock);
 928         INIT_LIST_HEAD(&sbi->s_dirty_files);
 929
 930         /*
 931          * Following initialization is overlapped because
 932          * nilfs_sb_info structure has been cleared at the beginning.
 933          * But we reserve them to keep our interest and make ready
 934          * for the future change.
 935          */
 936         get_random_bytes(&sbi->s_next_generation,
 937                          sizeof(sbi->s_next_generation));
 938         spin_lock_init(&sbi->s_next_gen_lock);
 939
 940         sb->s_op = &nilfs_sops;
 941         sb->s_export_op = &nilfs_export_ops;
 942         sb->s_root = NULL;
 943         sb->s_time_gran = 1;
 944
 945         bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 946         sb->s_bdi = bdi ? : &default_backing_dev_info;
 947
 948         err = load_nilfs(nilfs, sbi);
 949         if (err)
 950                 goto failed_nilfs;
 951
 952         cno = nilfs_last_cno(nilfs);
 953         err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
 954         if (err) {
 955                 printk(KERN_ERR "NILFS: error loading last checkpoint "
 956                        "(checkpoint number=%llu).\n", (unsigned long long)cno);
 957                 goto failed_unload;
 958         }
 959
 960         if (!(sb->s_flags & MS_RDONLY)) {
 961                 err = nilfs_attach_segment_constructor(sbi, fsroot);
 962                 if (err)
 963                         goto failed_checkpoint;
 964         }
 965
 966         err = nilfs_get_root_dentry(sb, fsroot, &sb->s_root);
 967         if (err)
 968                 goto failed_segctor;
 969
 970         nilfs_put_root(fsroot);
 971
 972         if (!(sb->s_flags & MS_RDONLY)) {
 973                 down_write(&nilfs->ns_sem);
 974                 nilfs_setup_super(sbi, true);
 975                 up_write(&nilfs->ns_sem);
 976         }
 977
 978         return 0;
 979
 980  failed_segctor:
 981         nilfs_detach_segment_constructor(sbi);
 982
 983  failed_checkpoint:
 984         nilfs_put_root(fsroot);
 985
 986  failed_unload:
 987         iput(nilfs->ns_sufile);
 988         iput(nilfs->ns_cpfile);
 989         iput(nilfs->ns_dat);
 990
 991  failed_nilfs:
 992         destroy_nilfs(nilfs);
 993
 994  failed_sbi:
 995         sb->s_fs_info = NULL;
 996         kfree(sbi);
 997         return err;
 998 }
 999
1000 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
1001 {
1002         struct nilfs_sb_info *sbi = NILFS_SB(sb);
1003         struct the_nilfs *nilfs = sbi->s_nilfs;
1004         unsigned long old_sb_flags;
1005         struct nilfs_mount_options old_opts;
1006         int err;
1007
1008         old_sb_flags = sb->s_flags;
1009         old_opts.mount_opt = sbi->s_mount_opt;
1010
1011         if (!parse_options(data, sb, 1)) {
1012                 err = -EINVAL;
1013                 goto restore_opts;
1014         }
1015         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
1016
1017         err = -EINVAL;
1018
1019         if (!nilfs_valid_fs(nilfs)) {
1020                 printk(KERN_WARNING "NILFS (device %s): couldn't "
1021                        "remount because the filesystem is in an "
1022                        "incomplete recovery state.\n", sb->s_id);
1023                 goto restore_opts;
1024         }
1025
1026         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1027                 goto out;
1028         if (*flags & MS_RDONLY) {
1029                 /* Shutting down the segment constructor */
1030                 nilfs_detach_segment_constructor(sbi);
1031                 sb->s_flags |= MS_RDONLY;
1032
1033                 /*
1034                  * Remounting a valid RW partition RDONLY, so set
1035                  * the RDONLY flag and then mark the partition as valid again.
1036                  */
1037                 down_write(&nilfs->ns_sem);
1038                 nilfs_cleanup_super(sbi);
1039                 up_write(&nilfs->ns_sem);
1040         } else {
1041                 __u64 features;
1042                 struct nilfs_root *root;
1043
1044                 /*
1045                  * Mounting a RDONLY partition read-write, so reread and
1046                  * store the current valid flag.  (It may have been changed
1047                  * by fsck since we originally mounted the partition.)
1048                  */
1049                 down_read(&nilfs->ns_sem);
1050                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1051                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
1052                 up_read(&nilfs->ns_sem);
1053                 if (features) {
1054                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1055                                "remount RDWR because of unsupported optional "
1056                                "features (%llx)\n",
1057                                sb->s_id, (unsigned long long)features);
1058                         err = -EROFS;
1059                         goto restore_opts;
1060                 }
1061
1062                 sb->s_flags &= ~MS_RDONLY;
1063
1064                 root = NILFS_I(sb->s_root->d_inode)->i_root;
1065                 err = nilfs_attach_segment_constructor(sbi, root);
1066                 if (err)
1067                         goto restore_opts;
1068
1069                 down_write(&nilfs->ns_sem);
1070                 nilfs_setup_super(sbi, true);
1071                 up_write(&nilfs->ns_sem);
1072         }
1073  out:
1074         return 0;
1075
1076  restore_opts:
1077         sb->s_flags = old_sb_flags;
1078         sbi->s_mount_opt = old_opts.mount_opt;
1079         return err;
1080 }
1081
1082 struct nilfs_super_data {
1083         struct block_device *bdev;
1084         struct nilfs_sb_info *sbi;
1085         __u64 cno;
1086         int flags;
1087 };
1088
1089 /**
1090  * nilfs_identify - pre-read mount options needed to identify mount instance
1091  * @data: mount options
1092  * @sd: nilfs_super_data
1093  */
1094 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1095 {
1096         char *p, *options = data;
1097         substring_t args[MAX_OPT_ARGS];
1098         int token;
1099         int ret = 0;
1100
1101         do {
1102                 p = strsep(&options, ",");
1103                 if (p != NULL && *p) {
1104                         token = match_token(p, tokens, args);
1105                         if (token == Opt_snapshot) {
1106                                 if (!(sd->flags & MS_RDONLY)) {
1107                                         ret++;
1108                                 } else {
1109                                         sd->cno = simple_strtoull(args[0].from,
1110                                                                   NULL, 0);
1111                                         /*
1112                                          * No need to see the end pointer;
1113                                          * match_token() has done syntax
1114                                          * checking.
1115                                          */
1116                                         if (sd->cno == 0)
1117                                                 ret++;
1118                                 }
1119                         }
1120                         if (ret)
1121                                 printk(KERN_ERR
1122                                        "NILFS: invalid mount option: %s\n", p);
1123                 }
1124                 if (!options)
1125                         break;
1126                 BUG_ON(options == data);
1127                 *(options - 1) = ',';
1128         } while (!ret);
1129         return ret;
1130 }
1131
1132 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1133 {
1134         s->s_bdev = data;
1135         s->s_dev = s->s_bdev->bd_dev;
1136         return 0;
1137 }
1138
1139 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1140 {
1141         return (void *)s->s_bdev == data;
1142 }
1143
1144 static struct dentry *
1145 nilfs_mount(struct file_system_type *fs_type, int flags,
1146              const char *dev_name, void *data)
1147 {
1148         struct nilfs_super_data sd;
1149         struct super_block *s;
1150         fmode_t mode = FMODE_READ;
1151         struct dentry *root_dentry;
1152         int err, s_new = false;
1153
1154         if (!(flags & MS_RDONLY))
1155                 mode |= FMODE_WRITE;
1156
1157         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1158         if (IS_ERR(sd.bdev))
1159                 return ERR_CAST(sd.bdev);
1160
1161         sd.cno = 0;
1162         sd.flags = flags;
1163         if (nilfs_identify((char *)data, &sd)) {
1164                 err = -EINVAL;
1165                 goto failed;
1166         }
1167
1168         /*
1169          * once the super is inserted into the list by sget, s_umount
1170          * will protect the lockfs code from trying to start a snapshot
1171          * while we are mounting
1172          */
1173         mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
1174         if (sd.bdev->bd_fsfreeze_count > 0) {
1175                 mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1176                 err = -EBUSY;
1177                 goto failed;
1178         }
1179         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
1180         mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
1181         if (IS_ERR(s)) {
1182                 err = PTR_ERR(s);
1183                 goto failed;
1184         }
1185
1186         if (!s->s_root) {
1187                 char b[BDEVNAME_SIZE];
1188
1189                 s_new = true;
1190
1191                 /* New superblock instance created */
1192                 s->s_flags = flags;
1193                 s->s_mode = mode;
1194                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1195                 sb_set_blocksize(s, block_size(sd.bdev));
1196
1197                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
1198                 if (err)
1199                         goto failed_super;
1200
1201                 s->s_flags |= MS_ACTIVE;
1202         } else if (!sd.cno) {
1203                 int busy = false;
1204
1205                 if (nilfs_tree_was_touched(s->s_root)) {
1206                         busy = nilfs_try_to_shrink_tree(s->s_root);
1207                         if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
1208                                 printk(KERN_ERR "NILFS: the device already "
1209                                        "has a %s mount.\n",
1210                                        (s->s_flags & MS_RDONLY) ?
1211                                        "read-only" : "read/write");
1212                                 err = -EBUSY;
1213                                 goto failed_super;
1214                         }
1215                 }
1216                 if (!busy) {
1217                         /*
1218                          * Try remount to setup mount states if the current
1219                          * tree is not mounted and only snapshots use this sb.
1220                          */
1221                         err = nilfs_remount(s, &flags, data);
1222                         if (err)
1223                                 goto failed_super;
1224                 }
1225         }
1226
1227         if (sd.cno) {
1228                 err = nilfs_attach_snapshot(s, sd.cno, &root_dentry);
1229                 if (err)
1230                         goto failed_super;
1231         } else {
1232                 root_dentry = dget(s->s_root);
1233         }
1234
1235         if (!s_new)
1236                 close_bdev_exclusive(sd.bdev, mode);
1237
1238         return root_dentry;
1239
1240  failed_super:
1241         deactivate_locked_super(s);
1242
1243  failed:
1244         if (!s_new)
1245                 close_bdev_exclusive(sd.bdev, mode);
1246         return ERR_PTR(err);
1247 }
1248
1249 struct file_system_type nilfs_fs_type = {
1250         .owner    = THIS_MODULE,
1251         .name     = "nilfs2",
1252         .mount    = nilfs_mount,
1253         .kill_sb  = kill_block_super,
1254         .fs_flags = FS_REQUIRES_DEV,
1255 };
1256
1257 static void nilfs_inode_init_once(void *obj)
1258 {
1259         struct nilfs_inode_info *ii = obj;
1260
1261         INIT_LIST_HEAD(&ii->i_dirty);
1262 #ifdef CONFIG_NILFS_XATTR
1263         init_rwsem(&ii->xattr_sem);
1264 #endif
1265         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1266         ii->i_bmap = &ii->i_bmap_data;
1267         inode_init_once(&ii->vfs_inode);
1268 }
1269
1270 static void nilfs_segbuf_init_once(void *obj)
1271 {
1272         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1273 }
1274
1275 static void nilfs_destroy_cachep(void)
1276 {
1277         if (nilfs_inode_cachep)
1278                 kmem_cache_destroy(nilfs_inode_cachep);
1279         if (nilfs_transaction_cachep)
1280                 kmem_cache_destroy(nilfs_transaction_cachep);
1281         if (nilfs_segbuf_cachep)
1282                 kmem_cache_destroy(nilfs_segbuf_cachep);
1283         if (nilfs_btree_path_cache)
1284                 kmem_cache_destroy(nilfs_btree_path_cache);
1285 }
1286
1287 static int __init nilfs_init_cachep(void)
1288 {
1289         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1290                         sizeof(struct nilfs_inode_info), 0,
1291                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1292         if (!nilfs_inode_cachep)
1293                 goto fail;
1294
1295         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1296                         sizeof(struct nilfs_transaction_info), 0,
1297                         SLAB_RECLAIM_ACCOUNT, NULL);
1298         if (!nilfs_transaction_cachep)
1299                 goto fail;
1300
1301         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1302                         sizeof(struct nilfs_segment_buffer), 0,
1303                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1304         if (!nilfs_segbuf_cachep)
1305                 goto fail;
1306
1307         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1308                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1309                         0, 0, NULL);
1310         if (!nilfs_btree_path_cache)
1311                 goto fail;
1312
1313         return 0;
1314
1315 fail:
1316         nilfs_destroy_cachep();
1317         return -ENOMEM;
1318 }
1319
1320 static int __init init_nilfs_fs(void)
1321 {
1322         int err;
1323
1324         err = nilfs_init_cachep();
1325         if (err)
1326                 goto fail;
1327
1328         err = register_filesystem(&nilfs_fs_type);
1329         if (err)
1330                 goto free_cachep;
1331
1332         printk(KERN_INFO "NILFS version 2 loaded\n");
1333         return 0;
1334
1335 free_cachep:
1336         nilfs_destroy_cachep();
1337 fail:
1338         return err;
1339 }
1340
1341 static void __exit exit_nilfs_fs(void)
1342 {
1343         nilfs_destroy_cachep();
1344         unregister_filesystem(&nilfs_fs_type);
1345 }
1346
1347 module_init(init_nilfs_fs)
1348 module_exit(exit_nilfs_fs)