nilfs2: add barrier mount option
[pandora-kernel.git] / fs / nilfs2 / super.c
index 48145f5..13b0e95 100644 (file)
@@ -67,8 +67,32 @@ MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
                   "(NILFS)");
 MODULE_LICENSE("GPL");
 
+struct kmem_cache *nilfs_inode_cachep;
+struct kmem_cache *nilfs_transaction_cachep;
+struct kmem_cache *nilfs_segbuf_cachep;
+struct kmem_cache *nilfs_btree_path_cache;
+
 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
 
+static void nilfs_set_error(struct nilfs_sb_info *sbi)
+{
+       struct the_nilfs *nilfs = sbi->s_nilfs;
+       struct nilfs_super_block **sbp;
+
+       down_write(&nilfs->ns_sem);
+       if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
+               nilfs->ns_mount_state |= NILFS_ERROR_FS;
+               sbp = nilfs_prepare_super(sbi, 0);
+               if (likely(sbp)) {
+                       sbp[0]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
+                       if (sbp[1])
+                               sbp[1]->s_state |= cpu_to_le16(NILFS_ERROR_FS);
+                       nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
+               }
+       }
+       up_write(&nilfs->ns_sem);
+}
+
 /**
  * nilfs_error() - report failure condition on a filesystem
  *
@@ -94,16 +118,7 @@ void nilfs_error(struct super_block *sb, const char *function,
        va_end(args);
 
        if (!(sb->s_flags & MS_RDONLY)) {
-               struct the_nilfs *nilfs = sbi->s_nilfs;
-
-               down_write(&nilfs->ns_sem);
-               if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
-                       nilfs->ns_mount_state |= NILFS_ERROR_FS;
-                       nilfs->ns_sbp[0]->s_state |=
-                               cpu_to_le16(NILFS_ERROR_FS);
-                       nilfs_commit_super(sbi, 1);
-               }
-               up_write(&nilfs->ns_sem);
+               nilfs_set_error(sbi);
 
                if (nilfs_test_opt(sbi, ERRORS_RO)) {
                        printk(KERN_CRIT "Remounting filesystem read-only\n");
@@ -129,7 +144,6 @@ void nilfs_warning(struct super_block *sb, const char *function,
        va_end(args);
 }
 
-static struct kmem_cache *nilfs_inode_cachep;
 
 struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
 {
@@ -155,34 +169,6 @@ void nilfs_destroy_inode(struct inode *inode)
        kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
 }
 
-static void init_once(void *obj)
-{
-       struct nilfs_inode_info *ii = obj;
-
-       INIT_LIST_HEAD(&ii->i_dirty);
-#ifdef CONFIG_NILFS_XATTR
-       init_rwsem(&ii->xattr_sem);
-#endif
-       nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
-       ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
-       inode_init_once(&ii->vfs_inode);
-}
-
-static int nilfs_init_inode_cache(void)
-{
-       nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
-                                              sizeof(struct nilfs_inode_info),
-                                              0, SLAB_RECLAIM_ACCOUNT,
-                                              init_once);
-
-       return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
-}
-
-static inline void nilfs_destroy_inode_cache(void)
-{
-       kmem_cache_destroy(nilfs_inode_cachep);
-}
-
 static void nilfs_clear_inode(struct inode *inode)
 {
        struct nilfs_inode_info *ii = NILFS_I(inode);
@@ -200,7 +186,7 @@ static void nilfs_clear_inode(struct inode *inode)
        nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 }
 
-static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
+static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
 {
        struct the_nilfs *nilfs = sbi->s_nilfs;
        int err;
@@ -226,12 +212,20 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
                printk(KERN_ERR
                       "NILFS: unable to write superblock (err=%d)\n", err);
                if (err == -EIO && nilfs->ns_sbh[1]) {
+                       /*
+                        * sbp[0] points to newer log than sbp[1],
+                        * so copy sbp[0] to sbp[1] to take over sbp[0].
+                        */
+                       memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
+                              nilfs->ns_sbsize);
                        nilfs_fall_back_super_block(nilfs);
                        goto retry;
                }
        } else {
                struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
 
+               nilfs->ns_sbwcount++;
+
                /*
                 * The latest segment becomes trailable from the position
                 * written in superblock.
@@ -240,66 +234,122 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
 
                /* update GC protection for recent segments */
                if (nilfs->ns_sbh[1]) {
-                       sbp = NULL;
-                       if (dupsb) {
+                       if (flag == NILFS_SB_COMMIT_ALL) {
                                set_buffer_dirty(nilfs->ns_sbh[1]);
-                               if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
-                                       sbp = nilfs->ns_sbp[1];
+                               if (sync_dirty_buffer(nilfs->ns_sbh[1]) < 0)
+                                       goto out;
                        }
+                       if (le64_to_cpu(nilfs->ns_sbp[1]->s_last_cno) <
+                           le64_to_cpu(nilfs->ns_sbp[0]->s_last_cno))
+                               sbp = nilfs->ns_sbp[1];
                }
-               if (sbp) {
-                       spin_lock(&nilfs->ns_last_segment_lock);
-                       nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
-                       spin_unlock(&nilfs->ns_last_segment_lock);
-               }
-       }
 
+               spin_lock(&nilfs->ns_last_segment_lock);
+               nilfs->ns_prot_seq = le64_to_cpu(sbp->s_last_seq);
+               spin_unlock(&nilfs->ns_last_segment_lock);
+       }
+ out:
        return err;
 }
 
-int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
+void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
+                         struct the_nilfs *nilfs)
+{
+       sector_t nfreeblocks;
+
+       /* nilfs->ns_sem must be locked by the caller. */
+       nilfs_count_free_blocks(nilfs, &nfreeblocks);
+       sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
+
+       spin_lock(&nilfs->ns_last_segment_lock);
+       sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
+       sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
+       sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
+       spin_unlock(&nilfs->ns_last_segment_lock);
+}
+
+struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
+                                              int flip)
 {
        struct the_nilfs *nilfs = sbi->s_nilfs;
        struct nilfs_super_block **sbp = nilfs->ns_sbp;
-       sector_t nfreeblocks;
-       time_t t;
-       int err;
 
-       /* nilfs->sem must be locked by the caller. */
-       if (sbp[0]->s_magic != NILFS_SUPER_MAGIC) {
-               if (sbp[1] && sbp[1]->s_magic == NILFS_SUPER_MAGIC)
-                       nilfs_swap_super_block(nilfs);
-               else {
+       /* nilfs->ns_sem must be locked by the caller. */
+       if (sbp[0]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
+               if (sbp[1] &&
+                   sbp[1]->s_magic == cpu_to_le16(NILFS_SUPER_MAGIC)) {
+                       memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
+               } else {
                        printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
                               sbi->s_super->s_id);
-                       return -EIO;
+                       return NULL;
                }
+       } else if (sbp[1] &&
+                  sbp[1]->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
+                       memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
        }
-       err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
-       if (unlikely(err)) {
-               printk(KERN_ERR "NILFS: failed to count free blocks\n");
-               return err;
-       }
-       spin_lock(&nilfs->ns_last_segment_lock);
-       sbp[0]->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
-       sbp[0]->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
-       sbp[0]->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
-       spin_unlock(&nilfs->ns_last_segment_lock);
 
+       if (flip && sbp[1])
+               nilfs_swap_super_block(nilfs);
+
+       return sbp;
+}
+
+int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
+{
+       struct the_nilfs *nilfs = sbi->s_nilfs;
+       struct nilfs_super_block **sbp = nilfs->ns_sbp;
+       time_t t;
+
+       /* nilfs->ns_sem must be locked by the caller. */
        t = get_seconds();
-       nilfs->ns_sbwtime[0] = t;
-       sbp[0]->s_free_blocks_count = cpu_to_le64(nfreeblocks);
+       nilfs->ns_sbwtime = t;
        sbp[0]->s_wtime = cpu_to_le64(t);
        sbp[0]->s_sum = 0;
        sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
                                             (unsigned char *)sbp[0],
                                             nilfs->ns_sbsize));
-       if (dupsb && sbp[1]) {
-               memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
-               nilfs->ns_sbwtime[1] = t;
+       if (flag == NILFS_SB_COMMIT_ALL && sbp[1]) {
+               sbp[1]->s_wtime = sbp[0]->s_wtime;
+               sbp[1]->s_sum = 0;
+               sbp[1]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
+                                           (unsigned char *)sbp[1],
+                                           nilfs->ns_sbsize));
        }
        clear_nilfs_sb_dirty(nilfs);
-       return nilfs_sync_super(sbi, dupsb);
+       return nilfs_sync_super(sbi, flag);
+}
+
+/**
+ * nilfs_cleanup_super() - write filesystem state for cleanup
+ * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
+ *
+ * This function restores state flags in the on-disk super block.
+ * This will set "clean" flag (i.e. NILFS_VALID_FS) unless the
+ * filesystem was not clean previously.
+ */
+int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
+{
+       struct nilfs_super_block **sbp;
+       int flag = NILFS_SB_COMMIT;
+       int ret = -EIO;
+
+       sbp = nilfs_prepare_super(sbi, 0);
+       if (sbp) {
+               sbp[0]->s_state = cpu_to_le16(sbi->s_nilfs->ns_mount_state);
+               nilfs_set_log_cursor(sbp[0], sbi->s_nilfs);
+               if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
+                       /*
+                        * make the "clean" flag also to the opposite
+                        * super block if both super blocks point to
+                        * the same checkpoint.
+                        */
+                       sbp[1]->s_state = sbp[0]->s_state;
+                       flag = NILFS_SB_COMMIT_ALL;
+               }
+               ret = nilfs_commit_super(sbi, flag);
+       }
+       return ret;
 }
 
 static void nilfs_put_super(struct super_block *sb)
@@ -313,8 +363,7 @@ static void nilfs_put_super(struct super_block *sb)
 
        if (!(sb->s_flags & MS_RDONLY)) {
                down_write(&nilfs->ns_sem);
-               nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
-               nilfs_commit_super(sbi, 1);
+               nilfs_cleanup_super(sbi);
                up_write(&nilfs->ns_sem);
        }
        down_write(&nilfs->ns_super_sem);
@@ -335,6 +384,7 @@ static int nilfs_sync_fs(struct super_block *sb, int wait)
 {
        struct nilfs_sb_info *sbi = NILFS_SB(sb);
        struct the_nilfs *nilfs = sbi->s_nilfs;
+       struct nilfs_super_block **sbp;
        int err = 0;
 
        /* This function is called when super block should be written back */
@@ -342,8 +392,13 @@ static int nilfs_sync_fs(struct super_block *sb, int wait)
                err = nilfs_construct_segment(sb);
 
        down_write(&nilfs->ns_sem);
-       if (nilfs_sb_dirty(nilfs))
-               nilfs_commit_super(sbi, 1);
+       if (nilfs_sb_dirty(nilfs)) {
+               sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
+               if (likely(sbp)) {
+                       nilfs_set_log_cursor(sbp[0], nilfs);
+                       nilfs_commit_super(sbi, NILFS_SB_COMMIT);
+               }
+       }
        up_write(&nilfs->ns_sem);
 
        return err;
@@ -470,10 +525,10 @@ static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
        if (nilfs_test_opt(sbi, SNAPSHOT))
                seq_printf(seq, ",cp=%llu",
                           (unsigned long long int)sbi->s_snapshot_cno);
-       if (nilfs_test_opt(sbi, ERRORS_RO))
-               seq_printf(seq, ",errors=remount-ro");
        if (nilfs_test_opt(sbi, ERRORS_PANIC))
                seq_printf(seq, ",errors=panic");
+       if (nilfs_test_opt(sbi, ERRORS_CONT))
+               seq_printf(seq, ",errors=continue");
        if (nilfs_test_opt(sbi, STRICT_ORDER))
                seq_printf(seq, ",order=strict");
        if (nilfs_test_opt(sbi, NORECOVERY))
@@ -548,7 +603,7 @@ static const struct export_operations nilfs_export_ops = {
 
 enum {
        Opt_err_cont, Opt_err_panic, Opt_err_ro,
-       Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
+       Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
        Opt_discard, Opt_err,
 };
 
@@ -556,6 +611,7 @@ static match_table_t tokens = {
        {Opt_err_cont, "errors=continue"},
        {Opt_err_panic, "errors=panic"},
        {Opt_err_ro, "errors=remount-ro"},
+       {Opt_barrier, "barrier"},
        {Opt_nobarrier, "nobarrier"},
        {Opt_snapshot, "cp=%u"},
        {Opt_order, "order=%s"},
@@ -581,6 +637,9 @@ static int parse_options(char *options, struct super_block *sb)
 
                token = match_token(p, tokens, args);
                switch (token) {
+               case Opt_barrier:
+                       nilfs_set_opt(sbi, BARRIER);
+                       break;
                case Opt_nobarrier:
                        nilfs_clear_opt(sbi, BARRIER);
                        break;
@@ -631,17 +690,24 @@ nilfs_set_default_options(struct nilfs_sb_info *sbi,
                          struct nilfs_super_block *sbp)
 {
        sbi->s_mount_opt =
-               NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
+               NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 }
 
 static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 {
        struct the_nilfs *nilfs = sbi->s_nilfs;
-       struct nilfs_super_block *sbp = nilfs->ns_sbp[0];
-       int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
-       int mnt_count = le16_to_cpu(sbp->s_mnt_count);
+       struct nilfs_super_block **sbp;
+       int max_mnt_count;
+       int mnt_count;
+
+       /* nilfs->ns_sem must be locked by the caller. */
+       sbp = nilfs_prepare_super(sbi, 0);
+       if (!sbp)
+               return -EIO;
+
+       max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);
+       mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
 
-       /* nilfs->sem must be locked by the caller. */
        if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
                printk(KERN_WARNING
                       "NILFS warning: mounting fs with errors\n");
@@ -652,12 +718,15 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi)
 #endif
        }
        if (!max_mnt_count)
-               sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
-
-       sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
-       sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
-       sbp->s_mtime = cpu_to_le64(get_seconds());
-       return nilfs_commit_super(sbi, 1);
+               sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
+
+       sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
+       sbp[0]->s_state =
+               cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
+       sbp[0]->s_mtime = cpu_to_le64(get_seconds());
+       /* synchronize sbp[1] with sbp[0] */
+       memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+       return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
 }
 
 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
@@ -778,9 +847,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
                                goto failed_sbi;
                        }
                        cno = sbi->s_snapshot_cno;
-               } else
-                       /* Read-only mount */
-                       sbi->s_snapshot_cno = cno;
+               }
        }
 
        err = nilfs_attach_checkpoint(sbi, cno);
@@ -845,11 +912,10 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent,
 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 {
        struct nilfs_sb_info *sbi = NILFS_SB(sb);
-       struct nilfs_super_block *sbp;
        struct the_nilfs *nilfs = sbi->s_nilfs;
        unsigned long old_sb_flags;
        struct nilfs_mount_options old_opts;
-       int err;
+       int was_snapshot, err;
 
        lock_kernel();
 
@@ -857,6 +923,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
        old_sb_flags = sb->s_flags;
        old_opts.mount_opt = sbi->s_mount_opt;
        old_opts.snapshot_cno = sbi->s_snapshot_cno;
+       was_snapshot = nilfs_test_opt(sbi, SNAPSHOT);
 
        if (!parse_options(data, sb)) {
                err = -EINVAL;
@@ -864,20 +931,32 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
        }
        sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
 
-       if ((*flags & MS_RDONLY) &&
-           sbi->s_snapshot_cno != old_opts.snapshot_cno) {
-               printk(KERN_WARNING "NILFS (device %s): couldn't "
-                      "remount to a different snapshot.\n",
-                      sb->s_id);
-               err = -EINVAL;
-               goto restore_opts;
+       err = -EINVAL;
+       if (was_snapshot) {
+               if (!(*flags & MS_RDONLY)) {
+                       printk(KERN_ERR "NILFS (device %s): cannot remount "
+                              "snapshot read/write.\n",
+                              sb->s_id);
+                       goto restore_opts;
+               } else if (sbi->s_snapshot_cno != old_opts.snapshot_cno) {
+                       printk(KERN_ERR "NILFS (device %s): cannot "
+                              "remount to a different snapshot.\n",
+                              sb->s_id);
+                       goto restore_opts;
+               }
+       } else {
+               if (nilfs_test_opt(sbi, SNAPSHOT)) {
+                       printk(KERN_ERR "NILFS (device %s): cannot change "
+                              "a regular mount to a snapshot.\n",
+                              sb->s_id);
+                       goto restore_opts;
+               }
        }
 
        if (!nilfs_valid_fs(nilfs)) {
                printk(KERN_WARNING "NILFS (device %s): couldn't "
                       "remount because the filesystem is in an "
                       "incomplete recovery state.\n", sb->s_id);
-               err = -EINVAL;
                goto restore_opts;
        }
 
@@ -888,20 +967,12 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
                nilfs_detach_segment_constructor(sbi);
                sb->s_flags |= MS_RDONLY;
 
-               sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
-               /* nilfs_set_opt(sbi, SNAPSHOT); */
-
                /*
                 * Remounting a valid RW partition RDONLY, so set
                 * the RDONLY flag and then mark the partition as valid again.
                 */
                down_write(&nilfs->ns_sem);
-               sbp = nilfs->ns_sbp[0];
-               if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
-                   (nilfs->ns_mount_state & NILFS_VALID_FS))
-                       sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
-               sbp->s_mtime = cpu_to_le64(get_seconds());
-               nilfs_commit_super(sbi, 1);
+               nilfs_cleanup_super(sbi);
                up_write(&nilfs->ns_sem);
        } else {
                /*
@@ -909,24 +980,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
                 * store the current valid flag.  (It may have been changed
                 * by fsck since we originally mounted the partition.)
                 */
-               if (nilfs->ns_current && nilfs->ns_current != sbi) {
-                       printk(KERN_WARNING "NILFS (device %s): couldn't "
-                              "remount because an RW-mount exists.\n",
-                              sb->s_id);
-                       err = -EBUSY;
-                       goto restore_opts;
-               }
-               if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
-                       printk(KERN_WARNING "NILFS (device %s): couldn't "
-                              "remount because the current RO-mount is not "
-                              "the latest one.\n",
-                              sb->s_id);
-                       err = -EINVAL;
-                       goto restore_opts;
-               }
                sb->s_flags &= ~MS_RDONLY;
-               nilfs_clear_opt(sbi, SNAPSHOT);
-               sbi->s_snapshot_cno = 0;
 
                err = nilfs_attach_segment_constructor(sbi);
                if (err)
@@ -935,8 +989,6 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
                down_write(&nilfs->ns_sem);
                nilfs_setup_super(sbi);
                up_write(&nilfs->ns_sem);
-
-               nilfs->ns_current = sbi;
        }
  out:
        up_write(&nilfs->ns_super_sem);
@@ -1022,10 +1074,14 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
 {
        struct nilfs_super_data sd;
        struct super_block *s;
+       fmode_t mode = FMODE_READ;
        struct the_nilfs *nilfs;
        int err, need_to_close = 1;
 
-       sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
+       if (!(flags & MS_RDONLY))
+               mode |= FMODE_WRITE;
+
+       sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
        if (IS_ERR(sd.bdev))
                return PTR_ERR(sd.bdev);
 
@@ -1092,10 +1148,12 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
 
                /* New superblock instance created */
                s->s_flags = flags;
+               s->s_mode = mode;
                strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
                sb_set_blocksize(s, block_size(sd.bdev));
 
-               err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
+               err = nilfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0,
+                                      nilfs);
                if (err)
                        goto cancel_new;
 
@@ -1106,7 +1164,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
        mutex_unlock(&nilfs->ns_mount_mutex);
        put_nilfs(nilfs);
        if (need_to_close)
-               close_bdev_exclusive(sd.bdev, flags);
+               close_bdev_exclusive(sd.bdev, mode);
        simple_set_mnt(mnt, s);
        return 0;
 
@@ -1114,7 +1172,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
        mutex_unlock(&nilfs->ns_mount_mutex);
        put_nilfs(nilfs);
  failed:
-       close_bdev_exclusive(sd.bdev, flags);
+       close_bdev_exclusive(sd.bdev, mode);
 
        return err;
 
@@ -1124,7 +1182,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
        put_nilfs(nilfs);
        deactivate_locked_super(s);
        /*
-        * deactivate_super() invokes close_bdev_exclusive().
+        * deactivate_locked_super() invokes close_bdev_exclusive().
         * We must finish all post-cleaning before this call;
         * put_nilfs() needs the block device.
         */
@@ -1139,54 +1197,93 @@ struct file_system_type nilfs_fs_type = {
        .fs_flags = FS_REQUIRES_DEV,
 };
 
-static int __init init_nilfs_fs(void)
+static void nilfs_inode_init_once(void *obj)
 {
-       int err;
-
-       err = nilfs_init_inode_cache();
-       if (err)
-               goto failed;
+       struct nilfs_inode_info *ii = obj;
 
-       err = nilfs_init_transaction_cache();
-       if (err)
-               goto failed_inode_cache;
+       INIT_LIST_HEAD(&ii->i_dirty);
+#ifdef CONFIG_NILFS_XATTR
+       init_rwsem(&ii->xattr_sem);
+#endif
+       nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
+       ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
+       inode_init_once(&ii->vfs_inode);
+}
 
-       err = nilfs_init_segbuf_cache();
-       if (err)
-               goto failed_transaction_cache;
+static void nilfs_segbuf_init_once(void *obj)
+{
+       memset(obj, 0, sizeof(struct nilfs_segment_buffer));
+}
 
-       err = nilfs_btree_path_cache_init();
-       if (err)
-               goto failed_segbuf_cache;
+static void nilfs_destroy_cachep(void)
+{
+       if (nilfs_inode_cachep)
+               kmem_cache_destroy(nilfs_inode_cachep);
+       if (nilfs_transaction_cachep)
+               kmem_cache_destroy(nilfs_transaction_cachep);
+       if (nilfs_segbuf_cachep)
+               kmem_cache_destroy(nilfs_segbuf_cachep);
+       if (nilfs_btree_path_cache)
+               kmem_cache_destroy(nilfs_btree_path_cache);
+}
 
-       err = register_filesystem(&nilfs_fs_type);
-       if (err)
-               goto failed_btree_path_cache;
+static int __init nilfs_init_cachep(void)
+{
+       nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
+                       sizeof(struct nilfs_inode_info), 0,
+                       SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
+       if (!nilfs_inode_cachep)
+               goto fail;
+
+       nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
+                       sizeof(struct nilfs_transaction_info), 0,
+                       SLAB_RECLAIM_ACCOUNT, NULL);
+       if (!nilfs_transaction_cachep)
+               goto fail;
+
+       nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
+                       sizeof(struct nilfs_segment_buffer), 0,
+                       SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
+       if (!nilfs_segbuf_cachep)
+               goto fail;
+
+       nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
+                       sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
+                       0, 0, NULL);
+       if (!nilfs_btree_path_cache)
+               goto fail;
 
        return 0;
 
- failed_btree_path_cache:
-       nilfs_btree_path_cache_destroy();
+fail:
+       nilfs_destroy_cachep();
+       return -ENOMEM;
+}
 
- failed_segbuf_cache:
-       nilfs_destroy_segbuf_cache();
+static int __init init_nilfs_fs(void)
+{
+       int err;
+
+       err = nilfs_init_cachep();
+       if (err)
+               goto fail;
 
- failed_transaction_cache:
-       nilfs_destroy_transaction_cache();
+       err = register_filesystem(&nilfs_fs_type);
+       if (err)
+               goto free_cachep;
 
- failed_inode_cache:
-       nilfs_destroy_inode_cache();
+       printk(KERN_INFO "NILFS version 2 loaded\n");
+       return 0;
 
- failed:
+free_cachep:
+       nilfs_destroy_cachep();
+fail:
        return err;
 }
 
 static void __exit exit_nilfs_fs(void)
 {
-       nilfs_destroy_segbuf_cache();
-       nilfs_destroy_transaction_cache();
-       nilfs_destroy_inode_cache();
-       nilfs_btree_path_cache_destroy();
+       nilfs_destroy_cachep();
        unregister_filesystem(&nilfs_fs_type);
 }