fs/nilfs2/super.c

   1 /*
   2  * super.c - NILFS module and super block management.
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21  */
  22 /*
  23  *  linux/fs/ext2/super.c
  24  *
  25  * Copyright (C) 1992, 1993, 1994, 1995
  26  * Remy Card (card@masi.ibp.fr)
  27  * Laboratoire MASI - Institut Blaise Pascal
  28  * Universite Pierre et Marie Curie (Paris VI)
  29  *
  30  *  from
  31  *
  32  *  linux/fs/minix/inode.c
  33  *
  34  *  Copyright (C) 1991, 1992  Linus Torvalds
  35  *
  36  *  Big-endian to little-endian byte-swapping/bitmaps by
  37  *        David S. Miller (davem@caip.rutgers.edu), 1995
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/string.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/parser.h>
  46 #include <linux/random.h>
  47 #include <linux/crc32.h>
  48 #include <linux/smp_lock.h>
  49 #include <linux/vfs.h>
  50 #include <linux/writeback.h>
  51 #include <linux/kobject.h>
  52 #include <linux/exportfs.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/mount.h>
  55 #include "nilfs.h"
  56 #include "mdt.h"
  57 #include "alloc.h"
  58 #include "btree.h"
  59 #include "btnode.h"
  60 #include "page.h"
  61 #include "cpfile.h"
  62 #include "ifile.h"
  63 #include "dat.h"
  64 #include "segment.h"
  65 #include "segbuf.h"
  66
  67 MODULE_AUTHOR("NTT Corp.");
  68 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
  69                    "(NILFS)");
  70 MODULE_LICENSE("GPL");
  71
  72 struct kmem_cache *nilfs_inode_cachep;
  73 struct kmem_cache *nilfs_transaction_cachep;
  74 struct kmem_cache *nilfs_segbuf_cachep;
  75 struct kmem_cache *nilfs_btree_path_cache;
  76
  77 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
  78
  79 static void nilfs_set_error(struct nilfs_sb_info *sbi)
  80 {
  81         struct the_nilfs *nilfs = sbi->s_nilfs;
  82         struct nilfs_super_block **sbp;
  83
  84         down_write(&nilfs->ns_sem);
  85         if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
  86                 nilfs->ns_mount_state |= NILFS_ERROR_FS;
  87                 sbp = nilfs_prepare_super(sbi, 0);
  88                 if (likely(sbp)) {
  89                         sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  90                         if (sbp[1])
  91                                 sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
  92                         nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
  93                 }
  94         }
  95         up_write(&nilfs->ns_sem);
  96 }
  97
  98 /**
  99  * nilfs_error() - report failure condition on a filesystem
 100  *
 101  * nilfs_error() sets an ERROR_FS flag on the superblock as well as
 102  * reporting an error message.  It should be called when NILFS detects
 103  * incoherences or defects of meta data on disk.  As for sustainable
 104  * errors such as a single-shot I/O error, nilfs_warning() or the printk()
 105  * function should be used instead.
 106  *
 107  * The segment constructor must not call this function because it can
 108  * kill itself.
 109  */
 110 void nilfs_error(struct super_block *sb, const char *function,
 111                  const char *fmt, ...)
 112 {
 113         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 114         va_list args;
 115
 116         va_start(args, fmt);
 117         printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
 118         vprintk(fmt, args);
 119         printk("\n");
 120         va_end(args);
 121
 122         if (!(sb->s_flags & MS_RDONLY)) {
 123                 nilfs_set_error(sbi);
 124
 125                 if (nilfs_test_opt(sbi, ERRORS_RO)) {
 126                         printk(KERN_CRIT "Remounting filesystem read-only\n");
 127                         sb->s_flags |= MS_RDONLY;
 128                 }
 129         }
 130
 131         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 132                 panic("NILFS (device %s): panic forced after error\n",
 133                       sb->s_id);
 134 }
 135
 136 void nilfs_warning(struct super_block *sb, const char *function,
 137                    const char *fmt, ...)
 138 {
 139         va_list args;
 140
 141         va_start(args, fmt);
 142         printk(KERN_WARNING "NILFS warning (device %s): %s: ",
 143                sb->s_id, function);
 144         vprintk(fmt, args);
 145         printk("\n");
 146         va_end(args);
 147 }
 148
 149
 150 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 151 {
 152         struct nilfs_inode_info *ii;
 153
 154         ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
 155         if (!ii)
 156                 return NULL;
 157         ii->i_bh = NULL;
 158         ii->i_state = 0;
 159         ii->vfs_inode.i_version = 1;
 160         nilfs_btnode_cache_init(&ii->i_btnode_cache, nilfs->ns_bdi);
 161         return &ii->vfs_inode;
 162 }
 163
 164 struct inode *nilfs_alloc_inode(struct super_block *sb)
 165 {
 166         return nilfs_alloc_inode_common(NILFS_SB(sb)->s_nilfs);
 167 }
 168
 169 void nilfs_destroy_inode(struct inode *inode)
 170 {
 171         kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 172 }
 173
 174 static void nilfs_clear_inode(struct inode *inode)
 175 {
 176         struct nilfs_inode_info *ii = NILFS_I(inode);
 177
 178         /*
 179          * Free resources allocated in nilfs_read_inode(), here.
 180          */
 181         BUG_ON(!list_empty(&ii->i_dirty));
 182         brelse(ii->i_bh);
 183         ii->i_bh = NULL;
 184
 185         if (test_bit(NILFS_I_BMAP, &ii->i_state))
 186                 nilfs_bmap_clear(ii->i_bmap);
 187
 188         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 189 }
 190
 191 static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 192 {
 193         struct the_nilfs *nilfs = sbi->s_nilfs;
 194         int err;
 195         int barrier_done = 0;
 196
 197         if (nilfs_test_opt(sbi, BARRIER)) {
 198                 set_buffer_ordered(nilfs->ns_sbh[0]);
 199                 barrier_done = 1;
 200         }
 201  retry:
 202         set_buffer_dirty(nilfs->ns_sbh[0]);
 203         err = sync_dirty_buffer(nilfs->ns_sbh[0]);
 204         if (err == -EOPNOTSUPP && barrier_done) {
 205                 nilfs_warning(sbi->s_super, __func__,
 206                               "barrier-based sync failed. "
 207                               "disabling barriers\n");
 208                 nilfs_clear_opt(sbi, BARRIER);
 209                 barrier_done = 0;
 210                 clear_buffer_ordered(nilfs->ns_sbh[0]);
 211                 goto retry;
 212         }
 213         if (unlikely(err)) {
 214                 printk(KERN_ERR
 215                        "NILFS: unable to write superblock (err=%d)\n", err);
 216                 if (err == -EIO && nilfs->ns_sbh[1]) {
 217                         /*
 218                          * sbp[0] points to newer log than sbp[1],
 219                          * so copy sbp[0] to sbp[1] to take over sbp[0].
 220                          */
 221                         memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
 222                                nilfs->ns_sbsize);
 223                         nilfs_fall_back_super_block(nilfs);
 224                         goto retry;
 225                 }
 226         } else {
 227                 struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 228
 229                 nilfs->ns_sbwcount++;
 230
 231                 /*
 232                  * The latest segment becomes trailable from the position
 233                  * written in superblock.
 234                  */
 235                 clear_nilfs_discontinued(nilfs);
 236
 237                 /* update GC protection for recent segments */
 238                 if (nilfs->ns_sbh[1]) {
 239                         if (flag == NILFS_SB_COMMIT_ALL) {
 240                                 set_buffer_dirty(nilfs->ns_sbh[1]);
 241                                 if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
 242                                         goto out;
 243                         }
 244                         if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
 245                             le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
 246                                 sbp = nilfs->ns_sbp[1];
 247                 }
 248
 249                 spin_lock(&nilfs->ns_last_segment_lock);
 250                 nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
 251                 spin_unlock(&nilfs->ns_last_segment_lock);
 252         }
 253  out:
 254         return err;
 255 }
 256
 257 void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 258                           struct the_nilfs *nilfs)
 259 {
 260         sector_t nfreeblocks;
 261
 262         /* nilfs->ns_sem must be locked by the caller. */
 263         nilfs_count_free_blocks(nilfs, &nfreeblocks);
 264         sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
 265
 266         spin_lock(&nilfs->ns_last_segment_lock);
 267         sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
 268         sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
 269         sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
 270         spin_unlock(&nilfs->ns_last_segment_lock);
 271 }
 272
 273 struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 274                                                int flip)
 275 {
 276         struct the_nilfs *nilfs = sbi->s_nilfs;
 277         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 278
 279         /* nilfs->ns_sem must be locked by the caller. */
 280         if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 281                 if (sbp[1] &&
 282                     sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
 283                         memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 284                 } else {
 285                         printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
 286                                sbi->s_super->s_id);
 287                         return NULL;
 288                 }
 289         } else if (sbp[1] &&
 290                    sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
 291                         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 292         }
 293
 294         if (flip && sbp[1])
 295                 nilfs_swap_super_block(nilfs);
 296
 297         return sbp;
 298 }
 299
 300 int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 301 {
 302         struct the_nilfs *nilfs = sbi->s_nilfs;
 303         struct nilfs_super_block **sbp = nilfs->ns_sbp;
 304         time_t t;
 305
 306         /* nilfs->ns_sem must be locked by the caller. */
 307         t = get_seconds();
 308         nilfs->ns_sbwtime = t;
 309         sbp[0]->s_wtime = cpu_to_le64(t);
 310         sbp[0]->s_sum = 0;
 311         sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 312                                              (unsigned char *)sbp[0],
 313                                              nilfs->ns_sbsize));
 314         if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
 315                 sbp[1]->s_wtime = sbp[0]->s_wtime;
 316                 sbp[1]->s_sum = 0;
 317                 sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
 318                                             (unsigned char *)sbp[1],
 319                                             nilfs->ns_sbsize));
 320         }
 321         clear_nilfs_sb_dirty(nilfs);
 322         return nilfs_sync_super(sbi, flag);
 323 }
 324
 325 /**
 326  * nilfs_cleanup_super() - write filesystem state for cleanup
 327  * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
 328  *
 329  * This function restores state flags in the on-disk super block.
 330  * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
 331  * filesystem was not clean previously.
 332  */
 333 int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 334 {
 335         struct nilfs_super_block **sbp;
 336         int flag = NILFS_SB_COMMIT;
 337         int ret = -EIO;
 338
 339         sbp = nilfs_prepare_super(sbi, 0);
 340         if (sbp) {
 341                 sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
 342                 nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
 343                 if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 344                         /*
 345                          * make the "clean" flag also to the opposite
 346                          * super block if both super blocks point to
 347                          * the same checkpoint.
 348                          */
 349                         sbp[1]->s_state = sbp[0]->s_state;
 350                         flag = NILFS_SB_COMMIT_ALL;
 351                 }
 352                 ret = nilfs_commit_super(sbi, flag);
 353         }
 354         return ret;
 355 }
 356
 357 static void nilfs_put_super(struct super_block *sb)
 358 {
 359         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 360         struct the_nilfs *nilfs = sbi->s_nilfs;
 361
 362         lock_kernel();
 363
 364         nilfs_detach_segment_constructor(sbi);
 365
 366         if (!(sb->s_flags & MS_RDONLY)) {
 367                 down_write(&nilfs->ns_sem);
 368                 nilfs_cleanup_super(sbi);
 369                 up_write(&nilfs->ns_sem);
 370         }
 371         down_write(&nilfs->ns_super_sem);
 372         if (nilfs->ns_current == sbi)
 373                 nilfs->ns_current = NULL;
 374         up_write(&nilfs->ns_super_sem);
 375
 376         nilfs_detach_checkpoint(sbi);
 377         put_nilfs(sbi->s_nilfs);
 378         sbi->s_super = NULL;
 379         sb->s_fs_info = NULL;
 380         nilfs_put_sbinfo(sbi);
 381
 382         unlock_kernel();
 383 }
 384
 385 static int nilfs_sync_fs(struct super_block *sb, int wait)
 386 {
 387         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 388         struct the_nilfs *nilfs = sbi->s_nilfs;
 389         struct nilfs_super_block **sbp;
 390         int err = 0;
 391
 392         /* This function is called when super block should be written back */
 393         if (wait)
 394                 err = nilfs_construct_segment(sb);
 395
 396         down_write(&nilfs->ns_sem);
 397         if (nilfs_sb_dirty(nilfs)) {
 398                 sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
 399                 if (likely(sbp)) {
 400                         nilfs_set_log_cursor(sbp[0], nilfs);
 401                         nilfs_commit_super(sbi, NILFS_SB_COMMIT);
 402                 }
 403         }
 404         up_write(&nilfs->ns_sem);
 405
 406         return err;
 407 }
 408
 409 int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
 410 {
 411         struct the_nilfs *nilfs = sbi->s_nilfs;
 412         struct nilfs_checkpoint *raw_cp;
 413         struct buffer_head *bh_cp;
 414         int err;
 415
 416         down_write(&nilfs->ns_super_sem);
 417         list_add(&sbi->s_list, &nilfs->ns_supers);
 418         up_write(&nilfs->ns_super_sem);
 419
 420         sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size);
 421         if (!sbi->s_ifile)
 422                 return -ENOMEM;
 423
 424         down_read(&nilfs->ns_segctor_sem);
 425         err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
 426                                           &bh_cp);
 427         up_read(&nilfs->ns_segctor_sem);
 428         if (unlikely(err)) {
 429                 if (err == -ENOENT || err == -EINVAL) {
 430                         printk(KERN_ERR
 431                                "NILFS: Invalid checkpoint "
 432                                "(checkpoint number=%llu)\n",
 433                                (unsigned long long)cno);
 434                         err = -EINVAL;
 435                 }
 436                 goto failed;
 437         }
 438         err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
 439         if (unlikely(err))
 440                 goto failed_bh;
 441         atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
 442         atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
 443
 444         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 445         return 0;
 446
 447  failed_bh:
 448         nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 449  failed:
 450         nilfs_mdt_destroy(sbi->s_ifile);
 451         sbi->s_ifile = NULL;
 452
 453         down_write(&nilfs->ns_super_sem);
 454         list_del_init(&sbi->s_list);
 455         up_write(&nilfs->ns_super_sem);
 456
 457         return err;
 458 }
 459
 460 void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
 461 {
 462         struct the_nilfs *nilfs = sbi->s_nilfs;
 463
 464         nilfs_mdt_destroy(sbi->s_ifile);
 465         sbi->s_ifile = NULL;
 466         down_write(&nilfs->ns_super_sem);
 467         list_del_init(&sbi->s_list);
 468         up_write(&nilfs->ns_super_sem);
 469 }
 470
 471 static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 472 {
 473         struct super_block *sb = dentry->d_sb;
 474         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 475         struct the_nilfs *nilfs = sbi->s_nilfs;
 476         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 477         unsigned long long blocks;
 478         unsigned long overhead;
 479         unsigned long nrsvblocks;
 480         sector_t nfreeblocks;
 481         int err;
 482
 483         /*
 484          * Compute all of the segment blocks
 485          *
 486          * The blocks before first segment and after last segment
 487          * are excluded.
 488          */
 489         blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
 490                 - nilfs->ns_first_data_block;
 491         nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
 492
 493         /*
 494          * Compute the overhead
 495          *
 496          * When distributing meta data blocks outside segment structure,
 497          * We must count them as the overhead.
 498          */
 499         overhead = 0;
 500
 501         err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
 502         if (unlikely(err))
 503                 return err;
 504
 505         buf->f_type = NILFS_SUPER_MAGIC;
 506         buf->f_bsize = sb->s_blocksize;
 507         buf->f_blocks = blocks - overhead;
 508         buf->f_bfree = nfreeblocks;
 509         buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 510                 (buf->f_bfree - nrsvblocks) : 0;
 511         buf->f_files = atomic_read(&sbi->s_inodes_count);
 512         buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 513         buf->f_namelen = NILFS_NAME_LEN;
 514         buf->f_fsid.val[0] = (u32)id;
 515         buf->f_fsid.val[1] = (u32)(id >> 32);
 516
 517         return 0;
 518 }
 519
 520 static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 521 {
 522         struct super_block *sb = vfs->mnt_sb;
 523         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 524
 525         if (!nilfs_test_opt(sbi, BARRIER))
 526                 seq_puts(seq, ",nobarrier");
 527         if (nilfs_test_opt(sbi, SNAPSHOT))
 528                 seq_printf(seq, ",cp=%llu",
 529                            (unsigned long long int)sbi->s_snapshot_cno);
 530         if (nilfs_test_opt(sbi, ERRORS_PANIC))
 531                 seq_puts(seq, ",errors=panic");
 532         if (nilfs_test_opt(sbi, ERRORS_CONT))
 533                 seq_puts(seq, ",errors=continue");
 534         if (nilfs_test_opt(sbi, STRICT_ORDER))
 535                 seq_puts(seq, ",order=strict");
 536         if (nilfs_test_opt(sbi, NORECOVERY))
 537                 seq_puts(seq, ",norecovery");
 538         if (nilfs_test_opt(sbi, DISCARD))
 539                 seq_puts(seq, ",discard");
 540
 541         return 0;
 542 }
 543
 544 static const struct super_operations nilfs_sops = {
 545         .alloc_inode    = nilfs_alloc_inode,
 546         .destroy_inode  = nilfs_destroy_inode,
 547         .dirty_inode    = nilfs_dirty_inode,
 548         /* .write_inode    = nilfs_write_inode, */
 549         /* .put_inode      = nilfs_put_inode, */
 550         /* .drop_inode    = nilfs_drop_inode, */
 551         .delete_inode   = nilfs_delete_inode,
 552         .put_super      = nilfs_put_super,
 553         /* .write_super    = nilfs_write_super, */
 554         .sync_fs        = nilfs_sync_fs,
 555         /* .write_super_lockfs */
 556         /* .unlockfs */
 557         .statfs         = nilfs_statfs,
 558         .remount_fs     = nilfs_remount,
 559         .clear_inode    = nilfs_clear_inode,
 560         /* .umount_begin */
 561         .show_options = nilfs_show_options
 562 };
 563
 564 static struct inode *
 565 nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 566 {
 567         struct inode *inode;
 568
 569         if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
 570             ino != NILFS_SKETCH_INO)
 571                 return ERR_PTR(-ESTALE);
 572
 573         inode = nilfs_iget(sb, ino);
 574         if (IS_ERR(inode))
 575                 return ERR_CAST(inode);
 576         if (generation && inode->i_generation != generation) {
 577                 iput(inode);
 578                 return ERR_PTR(-ESTALE);
 579         }
 580
 581         return inode;
 582 }
 583
 584 static struct dentry *
 585 nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
 586                    int fh_type)
 587 {
 588         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 589                                     nilfs_nfs_get_inode);
 590 }
 591
 592 static struct dentry *
 593 nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
 594                    int fh_type)
 595 {
 596         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 597                                     nilfs_nfs_get_inode);
 598 }
 599
 600 static const struct export_operations nilfs_export_ops = {
 601         .fh_to_dentry = nilfs_fh_to_dentry,
 602         .fh_to_parent = nilfs_fh_to_parent,
 603         .get_parent = nilfs_get_parent,
 604 };
 605
 606 enum {
 607         Opt_err_cont, Opt_err_panic, Opt_err_ro,
 608         Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
 609         Opt_discard, Opt_nodiscard, Opt_err,
 610 };
 611
 612 static match_table_t tokens = {
 613         {Opt_err_cont, "errors=continue"},
 614         {Opt_err_panic, "errors=panic"},
 615         {Opt_err_ro, "errors=remount-ro"},
 616         {Opt_barrier, "barrier"},
 617         {Opt_nobarrier, "nobarrier"},
 618         {Opt_snapshot, "cp=%u"},
 619         {Opt_order, "order=%s"},
 620         {Opt_norecovery, "norecovery"},
 621         {Opt_discard, "discard"},
 622         {Opt_nodiscard, "nodiscard"},
 623         {Opt_err, NULL}
 624 };
 625
 626 static int parse_options(char *options, struct super_block *sb, int is_remount)
 627 {
 628         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 629         char *p;
 630         substring_t args[MAX_OPT_ARGS];
 631         int option;
 632
 633         if (!options)
 634                 return 1;
 635
 636         while ((p = strsep(&options, ",")) != NULL) {
 637                 int token;
 638                 if (!*p)
 639                         continue;
 640
 641                 token = match_token(p, tokens, args);
 642                 switch (token) {
 643                 case Opt_barrier:
 644                         nilfs_set_opt(sbi, BARRIER);
 645                         break;
 646                 case Opt_nobarrier:
 647                         nilfs_clear_opt(sbi, BARRIER);
 648                         break;
 649                 case Opt_order:
 650                         if (strcmp(args[0].from, "relaxed") == 0)
 651                                 /* Ordered data semantics */
 652                                 nilfs_clear_opt(sbi, STRICT_ORDER);
 653                         else if (strcmp(args[0].from, "strict") == 0)
 654                                 /* Strict in-order semantics */
 655                                 nilfs_set_opt(sbi, STRICT_ORDER);
 656                         else
 657                                 return 0;
 658                         break;
 659                 case Opt_err_panic:
 660                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
 661                         break;
 662                 case Opt_err_ro:
 663                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
 664                         break;
 665                 case Opt_err_cont:
 666                         nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
 667                         break;
 668                 case Opt_snapshot:
 669                         if (match_int(&args[0], &option) || option <= 0)
 670                                 return 0;
 671                         if (is_remount) {
 672                                 if (!nilfs_test_opt(sbi, SNAPSHOT)) {
 673                                         printk(KERN_ERR
 674                                                "NILFS: cannot change regular "
 675                                                "mount to snapshot.\n");
 676                                         return 0;
 677                                 } else if (option != sbi->s_snapshot_cno) {
 678                                         printk(KERN_ERR
 679                                                "NILFS: cannot remount to a "
 680                                                "different snapshot.\n");
 681                                         return 0;
 682                                 }
 683                                 break;
 684                         }
 685                         if (!(sb->s_flags & MS_RDONLY)) {
 686                                 printk(KERN_ERR "NILFS: cannot mount snapshot "
 687                                        "read/write.  A read-only option is "
 688                                        "required.\n");
 689                                 return 0;
 690                         }
 691                         sbi->s_snapshot_cno = option;
 692                         nilfs_set_opt(sbi, SNAPSHOT);
 693                         break;
 694                 case Opt_norecovery:
 695                         nilfs_set_opt(sbi, NORECOVERY);
 696                         break;
 697                 case Opt_discard:
 698                         nilfs_set_opt(sbi, DISCARD);
 699                         break;
 700                 case Opt_nodiscard:
 701                         nilfs_clear_opt(sbi, DISCARD);
 702                         break;
 703                 default:
 704                         printk(KERN_ERR
 705                                "NILFS: Unrecognized mount option \"%s\"\n", p);
 706                         return 0;
 707                 }
 708         }
 709         return 1;
 710 }
 711
 712 static inline void
 713 nilfs_set_default_options(struct nilfs_sb_info *sbi,
 714                           struct nilfs_super_block *sbp)
 715 {
 716         sbi->s_mount_opt =
 717                 NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 718 }
 719
 720 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 721 {
 722         struct the_nilfs *nilfs = sbi->s_nilfs;
 723         struct nilfs_super_block **sbp;
 724         int max_mnt_count;
 725         int mnt_count;
 726
 727         /* nilfs->ns_sem must be locked by the caller. */
 728         sbp = nilfs_prepare_super(sbi, 0);
 729         if (!sbp)
 730                 return -EIO;
 731
 732         max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
 733         mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 734
 735         if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
 736                 printk(KERN_WARNING
 737                        "NILFS warning: mounting fs with errors\n");
 738 #if 0
 739         } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
 740                 printk(KERN_WARNING
 741                        "NILFS warning: maximal mount count reached\n");
 742 #endif
 743         }
 744         if (!max_mnt_count)
 745                 sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
 746
 747         sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
 748         sbp[0]->s_state =
 749                 cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
 750         sbp[0]->s_mtime = cpu_to_le64(get_seconds());
 751         /* synchronize sbp[1] with sbp[0] */
 752         memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 753         return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 754 }
 755
 756 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
 757                                                  u64 pos, int blocksize,
 758                                                  struct buffer_head **pbh)
 759 {
 760         unsigned long long sb_index = pos;
 761         unsigned long offset;
 762
 763         offset = do_div(sb_index, blocksize);
 764         *pbh = sb_bread(sb, sb_index);
 765         if (!*pbh)
 766                 return NULL;
 767         return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
 768 }
 769
 770 int nilfs_store_magic_and_option(struct super_block *sb,
 771                                  struct nilfs_super_block *sbp,
 772                                  char *data)
 773 {
 774         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 775
 776         sb->s_magic = le16_to_cpu(sbp->s_magic);
 777
 778         /* FS independent flags */
 779 #ifdef NILFS_ATIME_DISABLE
 780         sb->s_flags |= MS_NOATIME;
 781 #endif
 782
 783         nilfs_set_default_options(sbi, sbp);
 784
 785         sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
 786         sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
 787         sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
 788         sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
 789
 790         return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 791 }
 792
 793 int nilfs_check_feature_compatibility(struct super_block *sb,
 794                                       struct nilfs_super_block *sbp)
 795 {
 796         __u64 features;
 797
 798         features = le64_to_cpu(sbp->s_feature_incompat) &
 799                 ~NILFS_FEATURE_INCOMPAT_SUPP;
 800         if (features) {
 801                 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
 802                        "optional features (%llx)\n",
 803                        (unsigned long long)features);
 804                 return -EINVAL;
 805         }
 806         features = le64_to_cpu(sbp->s_feature_compat_ro) &
 807                 ~NILFS_FEATURE_COMPAT_RO_SUPP;
 808         if (!(sb->s_flags & MS_RDONLY) && features) {
 809                 printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
 810                        "unsupported optional features (%llx)\n",
 811                        (unsigned long long)features);
 812                 return -EINVAL;
 813         }
 814         return 0;
 815 }
 816
 817 /**
 818  * nilfs_fill_super() - initialize a super block instance
 819  * @sb: super_block
 820  * @data: mount options
 821  * @silent: silent mode flag
 822  * @nilfs: the_nilfs struct
 823  *
 824  * This function is called exclusively by nilfs->ns_mount_mutex.
 825  * So, the recovery process is protected from other simultaneous mounts.
 826  */
 827 static int
 828 nilfs_fill_super(struct super_block *sb, void *data, int silent,
 829                  struct the_nilfs *nilfs)
 830 {
 831         struct nilfs_sb_info *sbi;
 832         struct inode *root;
 833         __u64 cno;
 834         int err;
 835
 836         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 837         if (!sbi)
 838                 return -ENOMEM;
 839
 840         sb->s_fs_info = sbi;
 841
 842         get_nilfs(nilfs);
 843         sbi->s_nilfs = nilfs;
 844         sbi->s_super = sb;
 845         atomic_set(&sbi->s_count, 1);
 846
 847         err = init_nilfs(nilfs, sbi, (char *)data);
 848         if (err)
 849                 goto failed_sbi;
 850
 851         spin_lock_init(&sbi->s_inode_lock);
 852         INIT_LIST_HEAD(&sbi->s_dirty_files);
 853         INIT_LIST_HEAD(&sbi->s_list);
 854
 855         /*
 856          * Following initialization is overlapped because
 857          * nilfs_sb_info structure has been cleared at the beginning.
 858          * But we reserve them to keep our interest and make ready
 859          * for the future change.
 860          */
 861         get_random_bytes(&sbi->s_next_generation,
 862                          sizeof(sbi->s_next_generation));
 863         spin_lock_init(&sbi->s_next_gen_lock);
 864
 865         sb->s_op = &nilfs_sops;
 866         sb->s_export_op = &nilfs_export_ops;
 867         sb->s_root = NULL;
 868         sb->s_time_gran = 1;
 869         sb->s_bdi = nilfs->ns_bdi;
 870
 871         err = load_nilfs(nilfs, sbi);
 872         if (err)
 873                 goto failed_sbi;
 874
 875         cno = nilfs_last_cno(nilfs);
 876
 877         if (sb->s_flags & MS_RDONLY) {
 878                 if (nilfs_test_opt(sbi, SNAPSHOT)) {
 879                         down_read(&nilfs->ns_segctor_sem);
 880                         err = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
 881                                                        sbi->s_snapshot_cno);
 882                         up_read(&nilfs->ns_segctor_sem);
 883                         if (err < 0) {
 884                                 if (err == -ENOENT)
 885                                         err = -EINVAL;
 886                                 goto failed_sbi;
 887                         }
 888                         if (!err) {
 889                                 printk(KERN_ERR
 890                                        "NILFS: The specified checkpoint is "
 891                                        "not a snapshot "
 892                                        "(checkpoint number=%llu).\n",
 893                                        (unsigned long long)sbi->s_snapshot_cno);
 894                                 err = -EINVAL;
 895                                 goto failed_sbi;
 896                         }
 897                         cno = sbi->s_snapshot_cno;
 898                 }
 899         }
 900
 901         err = nilfs_attach_checkpoint(sbi, cno);
 902         if (err) {
 903                 printk(KERN_ERR "NILFS: error loading a checkpoint"
 904                        " (checkpoint number=%llu).\n", (unsigned long long)cno);
 905                 goto failed_sbi;
 906         }
 907
 908         if (!(sb->s_flags & MS_RDONLY)) {
 909                 err = nilfs_attach_segment_constructor(sbi);
 910                 if (err)
 911                         goto failed_checkpoint;
 912         }
 913
 914         root = nilfs_iget(sb, NILFS_ROOT_INO);
 915         if (IS_ERR(root)) {
 916                 printk(KERN_ERR "NILFS: get root inode failed\n");
 917                 err = PTR_ERR(root);
 918                 goto failed_segctor;
 919         }
 920         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 921                 iput(root);
 922                 printk(KERN_ERR "NILFS: corrupt root inode.\n");
 923                 err = -EINVAL;
 924                 goto failed_segctor;
 925         }
 926         sb->s_root = d_alloc_root(root);
 927         if (!sb->s_root) {
 928                 iput(root);
 929                 printk(KERN_ERR "NILFS: get root dentry failed\n");
 930                 err = -ENOMEM;
 931                 goto failed_segctor;
 932         }
 933
 934         if (!(sb->s_flags & MS_RDONLY)) {
 935                 down_write(&nilfs->ns_sem);
 936                 nilfs_setup_super(sbi);
 937                 up_write(&nilfs->ns_sem);
 938         }
 939
 940         down_write(&nilfs->ns_super_sem);
 941         if (!nilfs_test_opt(sbi, SNAPSHOT))
 942                 nilfs->ns_current = sbi;
 943         up_write(&nilfs->ns_super_sem);
 944
 945         return 0;
 946
 947  failed_segctor:
 948         nilfs_detach_segment_constructor(sbi);
 949
 950  failed_checkpoint:
 951         nilfs_detach_checkpoint(sbi);
 952
 953  failed_sbi:
 954         put_nilfs(nilfs);
 955         sb->s_fs_info = NULL;
 956         nilfs_put_sbinfo(sbi);
 957         return err;
 958 }
 959
 960 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 961 {
 962         struct nilfs_sb_info *sbi = NILFS_SB(sb);
 963         struct the_nilfs *nilfs = sbi->s_nilfs;
 964         unsigned long old_sb_flags;
 965         struct nilfs_mount_options old_opts;
 966         int was_snapshot, err;
 967
 968         lock_kernel();
 969
 970         down_write(&nilfs->ns_super_sem);
 971         old_sb_flags = sb->s_flags;
 972         old_opts.mount_opt = sbi->s_mount_opt;
 973         old_opts.snapshot_cno = sbi->s_snapshot_cno;
 974         was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 975
 976         if (!parse_options(data, sb, 1)) {
 977                 err = -EINVAL;
 978                 goto restore_opts;
 979         }
 980         sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 981
 982         err = -EINVAL;
 983         if (was_snapshot && !(*flags & MS_RDONLY)) {
 984                 printk(KERN_ERR "NILFS (device %s): cannot remount snapshot "
 985                        "read/write.\n", sb->s_id);
 986                 goto restore_opts;
 987         }
 988
 989         if (!nilfs_valid_fs(nilfs)) {
 990                 printk(KERN_WARNING "NILFS (device %s): couldn't "
 991                        "remount because the filesystem is in an "
 992                        "incomplete recovery state.\n", sb->s_id);
 993                 goto restore_opts;
 994         }
 995
 996         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 997                 goto out;
 998         if (*flags & MS_RDONLY) {
 999                 /* Shutting down the segment constructor */
1000                 nilfs_detach_segment_constructor(sbi);
1001                 sb->s_flags |= MS_RDONLY;
1002
1003                 /*
1004                  * Remounting a valid RW partition RDONLY, so set
1005                  * the RDONLY flag and then mark the partition as valid again.
1006                  */
1007                 down_write(&nilfs->ns_sem);
1008                 nilfs_cleanup_super(sbi);
1009                 up_write(&nilfs->ns_sem);
1010         } else {
1011                 __u64 features;
1012
1013                 /*
1014                  * Mounting a RDONLY partition read-write, so reread and
1015                  * store the current valid flag.  (It may have been changed
1016                  * by fsck since we originally mounted the partition.)
1017                  */
1018                 down_read(&nilfs->ns_sem);
1019                 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
1020                         ~NILFS_FEATURE_COMPAT_RO_SUPP;
1021                 up_read(&nilfs->ns_sem);
1022                 if (features) {
1023                         printk(KERN_WARNING "NILFS (device %s): couldn't "
1024                                "remount RDWR because of unsupported optional "
1025                                "features (%llx)\n",
1026                                sb->s_id, (unsigned long long)features);
1027                         err = -EROFS;
1028                         goto restore_opts;
1029                 }
1030
1031                 sb->s_flags &= ~MS_RDONLY;
1032
1033                 err = nilfs_attach_segment_constructor(sbi);
1034                 if (err)
1035                         goto restore_opts;
1036
1037                 down_write(&nilfs->ns_sem);
1038                 nilfs_setup_super(sbi);
1039                 up_write(&nilfs->ns_sem);
1040         }
1041  out:
1042         up_write(&nilfs->ns_super_sem);
1043         unlock_kernel();
1044         return 0;
1045
1046  restore_opts:
1047         sb->s_flags = old_sb_flags;
1048         sbi->s_mount_opt = old_opts.mount_opt;
1049         sbi->s_snapshot_cno = old_opts.snapshot_cno;
1050         up_write(&nilfs->ns_super_sem);
1051         unlock_kernel();
1052         return err;
1053 }
1054
1055 struct nilfs_super_data {
1056         struct block_device *bdev;
1057         struct nilfs_sb_info *sbi;
1058         __u64 cno;
1059         int flags;
1060 };
1061
1062 /**
1063  * nilfs_identify - pre-read mount options needed to identify mount instance
1064  * @data: mount options
1065  * @sd: nilfs_super_data
1066  */
1067 static int nilfs_identify(char *data, struct nilfs_super_data *sd)
1068 {
1069         char *p, *options = data;
1070         substring_t args[MAX_OPT_ARGS];
1071         int option, token;
1072         int ret = 0;
1073
1074         do {
1075                 p = strsep(&options, ",");
1076                 if (p != NULL && *p) {
1077                         token = match_token(p, tokens, args);
1078                         if (token == Opt_snapshot) {
1079                                 if (!(sd->flags & MS_RDONLY))
1080                                         ret++;
1081                                 else {
1082                                         ret = match_int(&args[0], &option);
1083                                         if (!ret) {
1084                                                 if (option > 0)
1085                                                         sd->cno = option;
1086                                                 else
1087                                                         ret++;
1088                                         }
1089                                 }
1090                         }
1091                         if (ret)
1092                                 printk(KERN_ERR
1093                                        "NILFS: invalid mount option: %s\n", p);
1094                 }
1095                 if (!options)
1096                         break;
1097                 BUG_ON(options == data);
1098                 *(options - 1) = ',';
1099         } while (!ret);
1100         return ret;
1101 }
1102
1103 static int nilfs_set_bdev_super(struct super_block *s, void *data)
1104 {
1105         struct nilfs_super_data *sd = data;
1106
1107         s->s_bdev = sd->bdev;
1108         s->s_dev = s->s_bdev->bd_dev;
1109         return 0;
1110 }
1111
1112 static int nilfs_test_bdev_super(struct super_block *s, void *data)
1113 {
1114         struct nilfs_super_data *sd = data;
1115
1116         return sd->sbi && s->s_fs_info == (void *)sd->sbi;
1117 }
1118
1119 static int
1120 nilfs_get_sb(struct file_system_type *fs_type, int flags,
1121              const char *dev_name, void *data, struct vfsmount *mnt)
1122 {
1123         struct nilfs_super_data sd;
1124         struct super_block *s;
1125         fmode_t mode = FMODE_READ;
1126         struct the_nilfs *nilfs;
1127         int err, need_to_close = 1;
1128
1129         if (!(flags & MS_RDONLY))
1130                 mode |= FMODE_WRITE;
1131
1132         sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
1133         if (IS_ERR(sd.bdev))
1134                 return PTR_ERR(sd.bdev);
1135
1136         /*
1137          * To get mount instance using sget() vfs-routine, NILFS needs
1138          * much more information than normal filesystems to identify mount
1139          * instance.  For snapshot mounts, not only a mount type (ro-mount
1140          * or rw-mount) but also a checkpoint number is required.
1141          */
1142         sd.cno = 0;
1143         sd.flags = flags;
1144         if (nilfs_identify((char *)data, &sd)) {
1145                 err = -EINVAL;
1146                 goto failed;
1147         }
1148
1149         nilfs = find_or_create_nilfs(sd.bdev);
1150         if (!nilfs) {
1151                 err = -ENOMEM;
1152                 goto failed;
1153         }
1154
1155         mutex_lock(&nilfs->ns_mount_mutex);
1156
1157         if (!sd.cno) {
1158                 /*
1159                  * Check if an exclusive mount exists or not.
1160                  * Snapshot mounts coexist with a current mount
1161                  * (i.e. rw-mount or ro-mount), whereas rw-mount and
1162                  * ro-mount are mutually exclusive.
1163                  */
1164                 down_read(&nilfs->ns_super_sem);
1165                 if (nilfs->ns_current &&
1166                     ((nilfs->ns_current->s_super->s_flags ^ flags)
1167                      & MS_RDONLY)) {
1168                         up_read(&nilfs->ns_super_sem);
1169                         err = -EBUSY;
1170                         goto failed_unlock;
1171                 }
1172                 up_read(&nilfs->ns_super_sem);
1173         }
1174
1175         /*
1176          * Find existing nilfs_sb_info struct
1177          */
1178         sd.sbi = nilfs_find_sbinfo(nilfs, !(flags & MS_RDONLY), sd.cno);
1179
1180         /*
1181          * Get super block instance holding the nilfs_sb_info struct.
1182          * A new instance is allocated if no existing mount is present or
1183          * existing instance has been unmounted.
1184          */
1185         s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
1186         if (sd.sbi)
1187                 nilfs_put_sbinfo(sd.sbi);
1188
1189         if (IS_ERR(s)) {
1190                 err = PTR_ERR(s);
1191                 goto failed_unlock;
1192         }
1193
1194         if (!s->s_root) {
1195                 char b[BDEVNAME_SIZE];
1196
1197                 /* New superblock instance created */
1198                 s->s_flags = flags;
1199                 s->s_mode = mode;
1200                 strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
1201                 sb_set_blocksize(s, block_size(sd.bdev));
1202
1203                 err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
1204                                        nilfs);
1205                 if (err)
1206                         goto cancel_new;
1207
1208                 s->s_flags |= MS_ACTIVE;
1209                 need_to_close = 0;
1210         }
1211
1212         mutex_unlock(&nilfs->ns_mount_mutex);
1213         put_nilfs(nilfs);
1214         if (need_to_close)
1215                 close_bdev_exclusive(sd.bdev, mode);
1216         simple_set_mnt(mnt, s);
1217         return 0;
1218
1219  failed_unlock:
1220         mutex_unlock(&nilfs->ns_mount_mutex);
1221         put_nilfs(nilfs);
1222  failed:
1223         close_bdev_exclusive(sd.bdev, mode);
1224
1225         return err;
1226
1227  cancel_new:
1228         /* Abandoning the newly allocated superblock */
1229         mutex_unlock(&nilfs->ns_mount_mutex);
1230         put_nilfs(nilfs);
1231         deactivate_locked_super(s);
1232         /*
1233          * deactivate_locked_super() invokes close_bdev_exclusive().
1234          * We must finish all post-cleaning before this call;
1235          * put_nilfs() needs the block device.
1236          */
1237         return err;
1238 }
1239
1240 struct file_system_type nilfs_fs_type = {
1241         .owner    = THIS_MODULE,
1242         .name     = "nilfs2",
1243         .get_sb   = nilfs_get_sb,
1244         .kill_sb  = kill_block_super,
1245         .fs_flags = FS_REQUIRES_DEV,
1246 };
1247
1248 static void nilfs_inode_init_once(void *obj)
1249 {
1250         struct nilfs_inode_info *ii = obj;
1251
1252         INIT_LIST_HEAD(&ii->i_dirty);
1253 #ifdef CONFIG_NILFS_XATTR
1254         init_rwsem(&ii->xattr_sem);
1255 #endif
1256         nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
1257         ii->i_bmap = &ii->i_bmap_data;
1258         inode_init_once(&ii->vfs_inode);
1259 }
1260
1261 static void nilfs_segbuf_init_once(void *obj)
1262 {
1263         memset(obj, 0, sizeof(struct nilfs_segment_buffer));
1264 }
1265
1266 static void nilfs_destroy_cachep(void)
1267 {
1268         if (nilfs_inode_cachep)
1269                 kmem_cache_destroy(nilfs_inode_cachep);
1270         if (nilfs_transaction_cachep)
1271                 kmem_cache_destroy(nilfs_transaction_cachep);
1272         if (nilfs_segbuf_cachep)
1273                 kmem_cache_destroy(nilfs_segbuf_cachep);
1274         if (nilfs_btree_path_cache)
1275                 kmem_cache_destroy(nilfs_btree_path_cache);
1276 }
1277
1278 static int __init nilfs_init_cachep(void)
1279 {
1280         nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
1281                         sizeof(struct nilfs_inode_info), 0,
1282                         SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
1283         if (!nilfs_inode_cachep)
1284                 goto fail;
1285
1286         nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
1287                         sizeof(struct nilfs_transaction_info), 0,
1288                         SLAB_RECLAIM_ACCOUNT, NULL);
1289         if (!nilfs_transaction_cachep)
1290                 goto fail;
1291
1292         nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
1293                         sizeof(struct nilfs_segment_buffer), 0,
1294                         SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
1295         if (!nilfs_segbuf_cachep)
1296                 goto fail;
1297
1298         nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
1299                         sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
1300                         0, 0, NULL);
1301         if (!nilfs_btree_path_cache)
1302                 goto fail;
1303
1304         return 0;
1305
1306 fail:
1307         nilfs_destroy_cachep();
1308         return -ENOMEM;
1309 }
1310
1311 static int __init init_nilfs_fs(void)
1312 {
1313         int err;
1314
1315         err = nilfs_init_cachep();
1316         if (err)
1317                 goto fail;
1318
1319         err = register_filesystem(&nilfs_fs_type);
1320         if (err)
1321                 goto free_cachep;
1322
1323         printk(KERN_INFO "NILFS version 2 loaded\n");
1324         return 0;
1325
1326 free_cachep:
1327         nilfs_destroy_cachep();
1328 fail:
1329         return err;
1330 }
1331
1332 static void __exit exit_nilfs_fs(void)
1333 {
1334         nilfs_destroy_cachep();
1335         unregister_filesystem(&nilfs_fs_type);
1336 }
1337
1338 module_init(init_nilfs_fs)
1339 module_exit(exit_nilfs_fs)