1 files changed, 273 insertions, 163 deletions

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 1673b3d9984..8c532b2ca3a 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -43,7 +43,6 @@
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/parser.h>
-#include <linux/random.h>
 #include <linux/crc32.h>
 #include <linux/vfs.h>
 #include <linux/writeback.h>
@@ -57,6 +56,7 @@
 #include "btnode.h"
 #include "page.h"
 #include "cpfile.h"
+#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
 #include "ifile.h"
 #include "dat.h"
 #include "segment.h"
@@ -72,23 +72,23 @@ struct kmem_cache *nilfs_transaction_cachep;
 struct kmem_cache *nilfs_segbuf_cachep;
 struct kmem_cache *nilfs_btree_path_cache;
 
-static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount);
+static int nilfs_setup_super(struct super_block *sb, int is_mount);
 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
 
-static void nilfs_set_error(struct nilfs_sb_info *sbi)
+static void nilfs_set_error(struct super_block *sb)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	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);
+		sbp = nilfs_prepare_super(sb, 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);
+			nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
 		}
 	}
 	up_write(&nilfs->ns_sem);
@@ -109,7 +109,7 @@ static void nilfs_set_error(struct nilfs_sb_info *sbi)
 void nilfs_error(struct super_block *sb, const char *function,
 		 const char *fmt, ...)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct va_format vaf;
 	va_list args;
 
@@ -124,15 +124,15 @@ void nilfs_error(struct super_block *sb, const char *function,
 	va_end(args);
 
 	if (!(sb->s_flags & MS_RDONLY)) {
-		nilfs_set_error(sbi);
+		nilfs_set_error(sb);
 
-		if (nilfs_test_opt(sbi, ERRORS_RO)) {
+		if (nilfs_test_opt(nilfs, ERRORS_RO)) {
 			printk(KERN_CRIT "Remounting filesystem read-only\n");
 			sb->s_flags |= MS_RDONLY;
 		}
 	}
 
-	if (nilfs_test_opt(sbi, ERRORS_PANIC))
+	if (nilfs_test_opt(nilfs, ERRORS_PANIC))
 		panic("NILFS (device %s): panic forced after error\n",
 		      sb->s_id);
 }
@@ -166,7 +166,7 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
 	ii->i_state = 0;
 	ii->i_cno = 0;
 	ii->vfs_inode.i_version = 1;
-	nilfs_btnode_cache_init(&ii->i_btnode_cache, sb->s_bdi);
+	nilfs_mapping_init(&ii->i_btnode_cache, &ii->vfs_inode, sb->s_bdi);
 	return &ii->vfs_inode;
 }
 
@@ -175,8 +175,6 @@ static void nilfs_i_callback(struct rcu_head *head)
 	struct inode *inode = container_of(head, struct inode, i_rcu);
 	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
-	INIT_LIST_HEAD(&inode->i_dentry);
-
 	if (mdi) {
 		kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
 		kfree(mdi);
@@ -189,14 +187,14 @@ void nilfs_destroy_inode(struct inode *inode)
 	call_rcu(&inode->i_rcu, nilfs_i_callback);
 }
 
-static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
+static int nilfs_sync_super(struct super_block *sb, int flag)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	int err;
 
  retry:
 	set_buffer_dirty(nilfs->ns_sbh[0]);
-	if (nilfs_test_opt(sbi, BARRIER)) {
+	if (nilfs_test_opt(nilfs, BARRIER)) {
 		err = __sync_dirty_buffer(nilfs->ns_sbh[0],
 					  WRITE_SYNC | WRITE_FLUSH_FUA);
 	} else {
@@ -263,10 +261,10 @@ void nilfs_set_log_cursor(struct nilfs_super_block *sbp,
 	spin_unlock(&nilfs->ns_last_segment_lock);
 }
 
-struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
+struct nilfs_super_block **nilfs_prepare_super(struct super_block *sb,
 					       int flip)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
 
 	/* nilfs->ns_sem must be locked by the caller. */
@@ -276,7 +274,7 @@ struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 			memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
 		} else {
 			printk(KERN_CRIT "NILFS: superblock broke on dev %s\n",
-			       sbi->s_super->s_id);
+			       sb->s_id);
 			return NULL;
 		}
 	} else if (sbp[1] &&
@@ -290,9 +288,9 @@ struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *sbi,
 	return sbp;
 }
 
-int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
+int nilfs_commit_super(struct super_block *sb, int flag)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
 	time_t t;
 
@@ -312,27 +310,28 @@ int nilfs_commit_super(struct nilfs_sb_info *sbi, int flag)
 					    nilfs->ns_sbsize));
 	}
 	clear_nilfs_sb_dirty(nilfs);
-	return nilfs_sync_super(sbi, flag);
+	return nilfs_sync_super(sb, flag);
 }
 
 /**
  * nilfs_cleanup_super() - write filesystem state for cleanup
- * @sbi: nilfs_sb_info to be unmounted or degraded to read-only
+ * @sb: super block instance 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)
+int nilfs_cleanup_super(struct super_block *sb)
 {
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_super_block **sbp;
 	int flag = NILFS_SB_COMMIT;
 	int ret = -EIO;
 
-	sbp = nilfs_prepare_super(sbi, 0);
+	sbp = nilfs_prepare_super(sb, 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);
+		sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
+		nilfs_set_log_cursor(sbp[0], nilfs);
 		if (sbp[1] && sbp[0]->s_last_cno == sbp[1]->s_last_cno) {
 			/*
 			 * make the "clean" flag also to the opposite
@@ -342,21 +341,148 @@ int nilfs_cleanup_super(struct nilfs_sb_info *sbi)
 			sbp[1]->s_state = sbp[0]->s_state;
 			flag = NILFS_SB_COMMIT_ALL;
 		}
-		ret = nilfs_commit_super(sbi, flag);
+		ret = nilfs_commit_super(sb, flag);
+	}
+	return ret;
+}
+
+/**
+ * nilfs_move_2nd_super - relocate secondary super block
+ * @sb: super block instance
+ * @sb2off: new offset of the secondary super block (in bytes)
+ */
+static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
+{
+	struct the_nilfs *nilfs = sb->s_fs_info;
+	struct buffer_head *nsbh;
+	struct nilfs_super_block *nsbp;
+	sector_t blocknr, newblocknr;
+	unsigned long offset;
+	int sb2i = -1;  /* array index of the secondary superblock */
+	int ret = 0;
+
+	/* nilfs->ns_sem must be locked by the caller. */
+	if (nilfs->ns_sbh[1] &&
+	    nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
+		sb2i = 1;
+		blocknr = nilfs->ns_sbh[1]->b_blocknr;
+	} else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
+		sb2i = 0;
+		blocknr = nilfs->ns_sbh[0]->b_blocknr;
+	}
+	if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
+		goto out;  /* super block location is unchanged */
+
+	/* Get new super block buffer */
+	newblocknr = sb2off >> nilfs->ns_blocksize_bits;
+	offset = sb2off & (nilfs->ns_blocksize - 1);
+	nsbh = sb_getblk(sb, newblocknr);
+	if (!nsbh) {
+		printk(KERN_WARNING
+		       "NILFS warning: unable to move secondary superblock "
+		       "to block %llu\n", (unsigned long long)newblocknr);
+		ret = -EIO;
+		goto out;
+	}
+	nsbp = (void *)nsbh->b_data + offset;
+	memset(nsbp, 0, nilfs->ns_blocksize);
+
+	if (sb2i >= 0) {
+		memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
+		brelse(nilfs->ns_sbh[sb2i]);
+		nilfs->ns_sbh[sb2i] = nsbh;
+		nilfs->ns_sbp[sb2i] = nsbp;
+	} else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
+		/* secondary super block will be restored to index 1 */
+		nilfs->ns_sbh[1] = nsbh;
+		nilfs->ns_sbp[1] = nsbp;
+	} else {
+		brelse(nsbh);
+	}
+out:
+	return ret;
+}
+
+/**
+ * nilfs_resize_fs - resize the filesystem
+ * @sb: super block instance
+ * @newsize: new size of the filesystem (in bytes)
+ */
+int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
+{
+	struct the_nilfs *nilfs = sb->s_fs_info;
+	struct nilfs_super_block **sbp;
+	__u64 devsize, newnsegs;
+	loff_t sb2off;
+	int ret;
+
+	ret = -ERANGE;
+	devsize = i_size_read(sb->s_bdev->bd_inode);
+	if (newsize > devsize)
+		goto out;
+
+	/*
+	 * Write lock is required to protect some functions depending
+	 * on the number of segments, the number of reserved segments,
+	 * and so forth.
+	 */
+	down_write(&nilfs->ns_segctor_sem);
+
+	sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
+	newnsegs = sb2off >> nilfs->ns_blocksize_bits;
+	do_div(newnsegs, nilfs->ns_blocks_per_segment);
+
+	ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
+	up_write(&nilfs->ns_segctor_sem);
+	if (ret < 0)
+		goto out;
+
+	ret = nilfs_construct_segment(sb);
+	if (ret < 0)
+		goto out;
+
+	down_write(&nilfs->ns_sem);
+	nilfs_move_2nd_super(sb, sb2off);
+	ret = -EIO;
+	sbp = nilfs_prepare_super(sb, 0);
+	if (likely(sbp)) {
+		nilfs_set_log_cursor(sbp[0], nilfs);
+		/*
+		 * Drop NILFS_RESIZE_FS flag for compatibility with
+		 * mount-time resize which may be implemented in a
+		 * future release.
+		 */
+		sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
+					      ~NILFS_RESIZE_FS);
+		sbp[0]->s_dev_size = cpu_to_le64(newsize);
+		sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
+		if (sbp[1])
+			memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+		ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
 	}
+	up_write(&nilfs->ns_sem);
+
+	/*
+	 * Reset the range of allocatable segments last.  This order
+	 * is important in the case of expansion because the secondary
+	 * superblock must be protected from log write until migration
+	 * completes.
+	 */
+	if (!ret)
+		nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
+out:
 	return ret;
 }
 
 static void nilfs_put_super(struct super_block *sb)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 
-	nilfs_detach_segment_constructor(sbi);
+	nilfs_detach_log_writer(sb);
 
 	if (!(sb->s_flags & MS_RDONLY)) {
 		down_write(&nilfs->ns_sem);
-		nilfs_cleanup_super(sbi);
+		nilfs_cleanup_super(sb);
 		up_write(&nilfs->ns_sem);
 	}
 
@@ -365,15 +491,12 @@ static void nilfs_put_super(struct super_block *sb)
 	iput(nilfs->ns_dat);
 
 	destroy_nilfs(nilfs);
-	sbi->s_super = NULL;
 	sb->s_fs_info = NULL;
-	kfree(sbi);
 }
 
 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 the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_super_block **sbp;
 	int err = 0;
 
@@ -383,10 +506,10 @@ static int nilfs_sync_fs(struct super_block *sb, int wait)
 
 	down_write(&nilfs->ns_sem);
 	if (nilfs_sb_dirty(nilfs)) {
-		sbp = nilfs_prepare_super(sbi, nilfs_sb_will_flip(nilfs));
+		sbp = nilfs_prepare_super(sb, nilfs_sb_will_flip(nilfs));
 		if (likely(sbp)) {
 			nilfs_set_log_cursor(sbp[0], nilfs);
-			nilfs_commit_super(sbi, NILFS_SB_COMMIT);
+			nilfs_commit_super(sb, NILFS_SB_COMMIT);
 		}
 	}
 	up_write(&nilfs->ns_sem);
@@ -394,10 +517,10 @@ static int nilfs_sync_fs(struct super_block *sb, int wait)
 	return err;
 }
 
-int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
+int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
 			    struct nilfs_root **rootp)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_root *root;
 	struct nilfs_checkpoint *raw_cp;
 	struct buffer_head *bh_cp;
@@ -426,13 +549,15 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 		goto failed;
 	}
 
-	err = nilfs_ifile_read(sbi->s_super, root, nilfs->ns_inode_size,
+	err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
 			       &raw_cp->cp_ifile_inode, &root->ifile);
 	if (err)
 		goto failed_bh;
 
-	atomic_set(&root->inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
-	atomic_set(&root->blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
+	atomic64_set(&root->inodes_count,
+			le64_to_cpu(raw_cp->cp_inodes_count));
+	atomic64_set(&root->blocks_count,
+			le64_to_cpu(raw_cp->cp_blocks_count));
 
 	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
 
@@ -450,8 +575,7 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt,
 
 static int nilfs_freeze(struct super_block *sb)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	int err;
 
 	if (sb->s_flags & MS_RDONLY)
@@ -459,21 +583,20 @@ static int nilfs_freeze(struct super_block *sb)
 
 	/* Mark super block clean */
 	down_write(&nilfs->ns_sem);
-	err = nilfs_cleanup_super(sbi);
+	err = nilfs_cleanup_super(sb);
 	up_write(&nilfs->ns_sem);
 	return err;
 }
 
 static int nilfs_unfreeze(struct super_block *sb)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 
 	if (sb->s_flags & MS_RDONLY)
 		return 0;
 
 	down_write(&nilfs->ns_sem);
-	nilfs_setup_super(sbi, false);
+	nilfs_setup_super(sb, false);
 	up_write(&nilfs->ns_sem);
 	return 0;
 }
@@ -488,6 +611,7 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	unsigned long overhead;
 	unsigned long nrsvblocks;
 	sector_t nfreeblocks;
+	u64 nmaxinodes, nfreeinodes;
 	int err;
 
 	/*
@@ -512,14 +636,34 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	if (unlikely(err))
 		return err;
 
+	err = nilfs_ifile_count_free_inodes(root->ifile,
+					    &nmaxinodes, &nfreeinodes);
+	if (unlikely(err)) {
+		printk(KERN_WARNING
+			"NILFS warning: fail to count free inodes: err %d.\n",
+			err);
+		if (err == -ERANGE) {
+			/*
+			 * If nilfs_palloc_count_max_entries() returns
+			 * -ERANGE error code then we simply treat
+			 * curent inodes count as maximum possible and
+			 * zero as free inodes value.
+			 */
+			nmaxinodes = atomic64_read(&root->inodes_count);
+			nfreeinodes = 0;
+			err = 0;
+		} else
+			return err;
+	}
+
 	buf->f_type = NILFS_SUPER_MAGIC;
 	buf->f_bsize = sb->s_blocksize;
 	buf->f_blocks = blocks - overhead;
 	buf->f_bfree = nfreeblocks;
 	buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
 		(buf->f_bfree - nrsvblocks) : 0;
-	buf->f_files = atomic_read(&root->inodes_count);
-	buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
+	buf->f_files = nmaxinodes;
+	buf->f_ffree = nfreeinodes;
 	buf->f_namelen = NILFS_NAME_LEN;
 	buf->f_fsid.val[0] = (u32)id;
 	buf->f_fsid.val[1] = (u32)(id >> 32);
@@ -527,25 +671,25 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
-static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
+static int nilfs_show_options(struct seq_file *seq, struct dentry *dentry)
 {
-	struct super_block *sb = vfs->mnt_sb;
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
-	struct nilfs_root *root = NILFS_I(vfs->mnt_root->d_inode)->i_root;
+	struct super_block *sb = dentry->d_sb;
+	struct the_nilfs *nilfs = sb->s_fs_info;
+	struct nilfs_root *root = NILFS_I(dentry->d_inode)->i_root;
 
-	if (!nilfs_test_opt(sbi, BARRIER))
+	if (!nilfs_test_opt(nilfs, BARRIER))
 		seq_puts(seq, ",nobarrier");
 	if (root->cno != NILFS_CPTREE_CURRENT_CNO)
 		seq_printf(seq, ",cp=%llu", (unsigned long long)root->cno);
-	if (nilfs_test_opt(sbi, ERRORS_PANIC))
+	if (nilfs_test_opt(nilfs, ERRORS_PANIC))
 		seq_puts(seq, ",errors=panic");
-	if (nilfs_test_opt(sbi, ERRORS_CONT))
+	if (nilfs_test_opt(nilfs, ERRORS_CONT))
 		seq_puts(seq, ",errors=continue");
-	if (nilfs_test_opt(sbi, STRICT_ORDER))
+	if (nilfs_test_opt(nilfs, STRICT_ORDER))
 		seq_puts(seq, ",order=strict");
-	if (nilfs_test_opt(sbi, NORECOVERY))
+	if (nilfs_test_opt(nilfs, NORECOVERY))
 		seq_puts(seq, ",norecovery");
-	if (nilfs_test_opt(sbi, DISCARD))
+	if (nilfs_test_opt(nilfs, DISCARD))
 		seq_puts(seq, ",discard");
 
 	return 0;
@@ -555,20 +699,13 @@ static const struct super_operations nilfs_sops = {
 	.alloc_inode    = nilfs_alloc_inode,
 	.destroy_inode  = nilfs_destroy_inode,
 	.dirty_inode    = nilfs_dirty_inode,
-	/* .write_inode    = nilfs_write_inode, */
-	/* .put_inode      = nilfs_put_inode, */
-	/* .drop_inode	  = nilfs_drop_inode, */
 	.evict_inode    = nilfs_evict_inode,
 	.put_super      = nilfs_put_super,
-	/* .write_super    = nilfs_write_super, */
 	.sync_fs        = nilfs_sync_fs,
 	.freeze_fs	= nilfs_freeze,
 	.unfreeze_fs	= nilfs_unfreeze,
-	/* .write_super_lockfs */
-	/* .unlockfs */
 	.statfs         = nilfs_statfs,
 	.remount_fs     = nilfs_remount,
-	/* .umount_begin */
 	.show_options = nilfs_show_options
 };
 
@@ -594,7 +731,7 @@ static match_table_t tokens = {
 
 static int parse_options(char *options, struct super_block *sb, int is_remount)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 
@@ -609,29 +746,29 @@ static int parse_options(char *options, struct super_block *sb, int is_remount)
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_barrier:
-			nilfs_set_opt(sbi, BARRIER);
+			nilfs_set_opt(nilfs, BARRIER);
 			break;
 		case Opt_nobarrier:
-			nilfs_clear_opt(sbi, BARRIER);
+			nilfs_clear_opt(nilfs, BARRIER);
 			break;
 		case Opt_order:
 			if (strcmp(args[0].from, "relaxed") == 0)
 				/* Ordered data semantics */
-				nilfs_clear_opt(sbi, STRICT_ORDER);
+				nilfs_clear_opt(nilfs, STRICT_ORDER);
 			else if (strcmp(args[0].from, "strict") == 0)
 				/* Strict in-order semantics */
-				nilfs_set_opt(sbi, STRICT_ORDER);
+				nilfs_set_opt(nilfs, STRICT_ORDER);
 			else
 				return 0;
 			break;
 		case Opt_err_panic:
-			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
+			nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_PANIC);
 			break;
 		case Opt_err_ro:
-			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
+			nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_RO);
 			break;
 		case Opt_err_cont:
-			nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
+			nilfs_write_opt(nilfs, ERROR_MODE, ERRORS_CONT);
 			break;
 		case Opt_snapshot:
 			if (is_remount) {
@@ -642,13 +779,13 @@ static int parse_options(char *options, struct super_block *sb, int is_remount)
 			}
 			break;
 		case Opt_norecovery:
-			nilfs_set_opt(sbi, NORECOVERY);
+			nilfs_set_opt(nilfs, NORECOVERY);
 			break;
 		case Opt_discard:
-			nilfs_set_opt(sbi, DISCARD);
+			nilfs_set_opt(nilfs, DISCARD);
 			break;
 		case Opt_nodiscard:
-			nilfs_clear_opt(sbi, DISCARD);
+			nilfs_clear_opt(nilfs, DISCARD);
 			break;
 		default:
 			printk(KERN_ERR
@@ -660,22 +797,24 @@ static int parse_options(char *options, struct super_block *sb, int is_remount)
 }
 
 static inline void
-nilfs_set_default_options(struct nilfs_sb_info *sbi,
+nilfs_set_default_options(struct super_block *sb,
 			  struct nilfs_super_block *sbp)
 {
-	sbi->s_mount_opt =
+	struct the_nilfs *nilfs = sb->s_fs_info;
+
+	nilfs->ns_mount_opt =
 		NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;
 }
 
-static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount)
+static int nilfs_setup_super(struct super_block *sb, int is_mount)
 {
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	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);
+	sbp = nilfs_prepare_super(sb, 0);
 	if (!sbp)
 		return -EIO;
 
@@ -706,7 +845,7 @@ skip_mount_setup:
 	/* synchronize sbp[1] with sbp[0] */
 	if (sbp[1])
 		memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
-	return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
+	return nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
 }
 
 struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
@@ -727,7 +866,7 @@ int nilfs_store_magic_and_option(struct super_block *sb,
 				 struct nilfs_super_block *sbp,
 				 char *data)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
+	struct the_nilfs *nilfs = sb->s_fs_info;
 
 	sb->s_magic = le16_to_cpu(sbp->s_magic);
 
@@ -736,12 +875,12 @@ int nilfs_store_magic_and_option(struct super_block *sb,
 	sb->s_flags |= MS_NOATIME;
 #endif
 
-	nilfs_set_default_options(sbi, sbp);
+	nilfs_set_default_options(sb, sbp);
 
-	sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
-	sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
-	sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
-	sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
+	nilfs->ns_resuid = le16_to_cpu(sbp->s_def_resuid);
+	nilfs->ns_resgid = le16_to_cpu(sbp->s_def_resgid);
+	nilfs->ns_interval = le32_to_cpu(sbp->s_c_interval);
+	nilfs->ns_watermark = le32_to_cpu(sbp->s_c_block_max);
 
 	return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 }
@@ -794,9 +933,8 @@ static int nilfs_get_root_dentry(struct super_block *sb,
 	if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
 		dentry = d_find_alias(inode);
 		if (!dentry) {
-			dentry = d_alloc_root(inode);
+			dentry = d_make_root(inode);
 			if (!dentry) {
-				iput(inode);
 				ret = -ENOMEM;
 				goto failed_dentry;
 			}
@@ -822,10 +960,12 @@ static int nilfs_get_root_dentry(struct super_block *sb,
 static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 				 struct dentry **root_dentry)
 {
-	struct the_nilfs *nilfs = NILFS_SB(s)->s_nilfs;
+	struct the_nilfs *nilfs = s->s_fs_info;
 	struct nilfs_root *root;
 	int ret;
 
+	mutex_lock(&nilfs->ns_snapshot_mount_mutex);
+
 	down_read(&nilfs->ns_segctor_sem);
 	ret = nilfs_cpfile_is_snapshot(nilfs->ns_cpfile, cno);
 	up_read(&nilfs->ns_segctor_sem);
@@ -840,7 +980,7 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 		goto out;
 	}
 
-	ret = nilfs_attach_checkpoint(NILFS_SB(s), cno, false, &root);
+	ret = nilfs_attach_checkpoint(s, cno, false, &root);
 	if (ret) {
 		printk(KERN_ERR "NILFS: error loading snapshot "
 		       "(checkpoint number=%llu).\n",
@@ -850,31 +990,25 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno,
 	ret = nilfs_get_root_dentry(s, root, root_dentry);
 	nilfs_put_root(root);
  out:
+	mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
 	return ret;
 }
 
-static int nilfs_tree_was_touched(struct dentry *root_dentry)
-{
-	return root_dentry->d_count > 1;
-}
-
 /**
- * nilfs_try_to_shrink_tree() - try to shrink dentries of a checkpoint
+ * nilfs_tree_is_busy() - try to shrink dentries of a checkpoint
  * @root_dentry: root dentry of the tree to be shrunk
  *
  * This function returns true if the tree was in-use.
  */
-static int nilfs_try_to_shrink_tree(struct dentry *root_dentry)
+static bool nilfs_tree_is_busy(struct dentry *root_dentry)
 {
-	if (have_submounts(root_dentry))
-		return true;
 	shrink_dcache_parent(root_dentry);
-	return nilfs_tree_was_touched(root_dentry);
+	return d_count(root_dentry) > 1;
 }
 
 int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
 {
-	struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_root *root;
 	struct inode *inode;
 	struct dentry *dentry;
@@ -887,14 +1021,13 @@ int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno)
 		return true;	/* protect recent checkpoints */
 
 	ret = false;
-	root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
+	root = nilfs_lookup_root(nilfs, cno);
 	if (root) {
 		inode = nilfs_ilookup(sb, root, NILFS_ROOT_INO);
 		if (inode) {
 			dentry = d_find_alias(inode);
 			if (dentry) {
-				if (nilfs_tree_was_touched(dentry))
-					ret = nilfs_try_to_shrink_tree(dentry);
+				ret = nilfs_tree_is_busy(dentry);
 				dput(dentry);
 			}
 			iput(inode);
@@ -917,57 +1050,36 @@ static int
 nilfs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct the_nilfs *nilfs;
-	struct nilfs_sb_info *sbi;
 	struct nilfs_root *fsroot;
 	struct backing_dev_info *bdi;
 	__u64 cno;
 	int err;
 
-	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
-	if (!sbi)
+	nilfs = alloc_nilfs(sb->s_bdev);
+	if (!nilfs)
 		return -ENOMEM;
 
-	sb->s_fs_info = sbi;
-	sbi->s_super = sb;
+	sb->s_fs_info = nilfs;
 
-	nilfs = alloc_nilfs(sb->s_bdev);
-	if (!nilfs) {
-		err = -ENOMEM;
-		goto failed_sbi;
-	}
-	sbi->s_nilfs = nilfs;
-
-	err = init_nilfs(nilfs, sbi, (char *)data);
+	err = init_nilfs(nilfs, sb, (char *)data);
 	if (err)
 		goto failed_nilfs;
 
-	spin_lock_init(&sbi->s_inode_lock);
-	INIT_LIST_HEAD(&sbi->s_dirty_files);
-
-	/*
-	 * Following initialization is overlapped because
-	 * nilfs_sb_info structure has been cleared at the beginning.
-	 * But we reserve them to keep our interest and make ready
-	 * for the future change.
-	 */
-	get_random_bytes(&sbi->s_next_generation,
-			 sizeof(sbi->s_next_generation));
-	spin_lock_init(&sbi->s_next_gen_lock);
-
 	sb->s_op = &nilfs_sops;
 	sb->s_export_op = &nilfs_export_ops;
 	sb->s_root = NULL;
 	sb->s_time_gran = 1;
+	sb->s_max_links = NILFS_LINK_MAX;
 
 	bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 	sb->s_bdi = bdi ? : &default_backing_dev_info;
 
-	err = load_nilfs(nilfs, sbi);
+	err = load_nilfs(nilfs, sb);
 	if (err)
 		goto failed_nilfs;
 
 	cno = nilfs_last_cno(nilfs);
-	err = nilfs_attach_checkpoint(sbi, cno, true, &fsroot);
+	err = nilfs_attach_checkpoint(sb, cno, true, &fsroot);
 	if (err) {
 		printk(KERN_ERR "NILFS: error loading last checkpoint "
 		       "(checkpoint number=%llu).\n", (unsigned long long)cno);
@@ -975,7 +1087,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	if (!(sb->s_flags & MS_RDONLY)) {
-		err = nilfs_attach_segment_constructor(sbi, fsroot);
+		err = nilfs_attach_log_writer(sb, fsroot);
 		if (err)
 			goto failed_checkpoint;
 	}
@@ -988,14 +1100,14 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	if (!(sb->s_flags & MS_RDONLY)) {
 		down_write(&nilfs->ns_sem);
-		nilfs_setup_super(sbi, true);
+		nilfs_setup_super(sb, true);
 		up_write(&nilfs->ns_sem);
 	}
 
 	return 0;
 
  failed_segctor:
-	nilfs_detach_segment_constructor(sbi);
+	nilfs_detach_log_writer(sb);
 
  failed_checkpoint:
 	nilfs_put_root(fsroot);
@@ -1007,23 +1119,19 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent)
 
  failed_nilfs:
 	destroy_nilfs(nilfs);
-
- failed_sbi:
-	sb->s_fs_info = NULL;
-	kfree(sbi);
 	return err;
 }
 
 static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 {
-	struct nilfs_sb_info *sbi = NILFS_SB(sb);
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sb->s_fs_info;
 	unsigned long old_sb_flags;
 	unsigned long old_mount_opt;
 	int err;
 
+	sync_filesystem(sb);
 	old_sb_flags = sb->s_flags;
-	old_mount_opt = sbi->s_mount_opt;
+	old_mount_opt = nilfs->ns_mount_opt;
 
 	if (!parse_options(data, sb, 1)) {
 		err = -EINVAL;
@@ -1043,8 +1151,8 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 		goto out;
 	if (*flags & MS_RDONLY) {
-		/* Shutting down the segment constructor */
-		nilfs_detach_segment_constructor(sbi);
+		/* Shutting down log writer */
+		nilfs_detach_log_writer(sb);
 		sb->s_flags |= MS_RDONLY;
 
 		/*
@@ -1052,7 +1160,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 		 * the RDONLY flag and then mark the partition as valid again.
 		 */
 		down_write(&nilfs->ns_sem);
-		nilfs_cleanup_super(sbi);
+		nilfs_cleanup_super(sb);
 		up_write(&nilfs->ns_sem);
 	} else {
 		__u64 features;
@@ -1079,12 +1187,12 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 		sb->s_flags &= ~MS_RDONLY;
 
 		root = NILFS_I(sb->s_root->d_inode)->i_root;
-		err = nilfs_attach_segment_constructor(sbi, root);
+		err = nilfs_attach_log_writer(sb, root);
 		if (err)
 			goto restore_opts;
 
 		down_write(&nilfs->ns_sem);
-		nilfs_setup_super(sbi, true);
+		nilfs_setup_super(sb, true);
 		up_write(&nilfs->ns_sem);
 	}
  out:
@@ -1092,13 +1200,12 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 
  restore_opts:
 	sb->s_flags = old_sb_flags;
-	sbi->s_mount_opt = old_mount_opt;
+	nilfs->ns_mount_opt = old_mount_opt;
 	return err;
 }
 
 struct nilfs_super_data {
 	struct block_device *bdev;
-	struct nilfs_sb_info *sbi;
 	__u64 cno;
 	int flags;
 };
@@ -1193,7 +1300,8 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
 		err = -EBUSY;
 		goto failed;
 	}
-	s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);
+	s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
+		 sd.bdev);
 	mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
 	if (IS_ERR(s)) {
 		err = PTR_ERR(s);
@@ -1206,7 +1314,6 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
 		s_new = true;
 
 		/* 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));
@@ -1217,11 +1324,8 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
 
 		s->s_flags |= MS_ACTIVE;
 	} else if (!sd.cno) {
-		int busy = false;
-
-		if (nilfs_tree_was_touched(s->s_root)) {
-			busy = nilfs_try_to_shrink_tree(s->s_root);
-			if (busy && (flags ^ s->s_flags) & MS_RDONLY) {
+		if (nilfs_tree_is_busy(s->s_root)) {
+			if ((flags ^ s->s_flags) & MS_RDONLY) {
 				printk(KERN_ERR "NILFS: the device already "
 				       "has a %s mount.\n",
 				       (s->s_flags & MS_RDONLY) ?
@@ -1229,8 +1333,7 @@ nilfs_mount(struct file_system_type *fs_type, int flags,
 				err = -EBUSY;
 				goto failed_super;
 			}
-		}
-		if (!busy) {
+		} else {
 			/*
 			 * Try remount to setup mount states if the current
 			 * tree is not mounted and only snapshots use this sb.
@@ -1270,6 +1373,7 @@ struct file_system_type nilfs_fs_type = {
 	.kill_sb  = kill_block_super,
 	.fs_flags = FS_REQUIRES_DEV,
 };
+MODULE_ALIAS_FS("nilfs2");
 
 static void nilfs_inode_init_once(void *obj)
 {
@@ -1291,6 +1395,12 @@ static void nilfs_segbuf_init_once(void *obj)
 
 static void nilfs_destroy_cachep(void)
 {
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+
 	if (nilfs_inode_cachep)
 		kmem_cache_destroy(nilfs_inode_cachep);
 	if (nilfs_transaction_cachep)