Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (21 commits)
  fs/Kconfig: move nilfs2 outside misc filesystems
  nilfs2: convert nilfs_bmap_lookup to an inline function
  nilfs2: allow btree code to directly call dat operations
  nilfs2: add update functions of virtual block address to dat
  nilfs2: remove individual gfp constants for each metadata file
  nilfs2: stop zero-fill of btree path just before free it
  nilfs2: remove unused btree argument from btree functions
  nilfs2: remove nilfs_dat_abort_start and nilfs_dat_abort_free
  nilfs2: shorten freeze period due to GC in write operation v3
  nilfs2: add more check routines in mount process
  nilfs2: An unassigned variable is assigned to a never used structure member
  nilfs2: use GFP_NOIO for bio_alloc instead of GFP_NOWAIT
  nilfs2: stop using periodic write_super callback
  nilfs2: clean up nilfs_write_super
  nilfs2: fix disorder of nilfs_write_super in nilfs_sync_fs
  nilfs2: remove redundant super block commit
  nilfs2: implement nilfs_show_options to display mount options in /proc/mounts
  nilfs2: always lookup disk block address before reading metadata block
  nilfs2: use semaphore to protect pointer to a writable FS-instance
  nilfs2: fix format string compile warning (ino_t)
  ...

1 files changed, 295 insertions, 330 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index aa412724b64e..e25b507a474f 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -71,21 +71,17 @@ void nilfs_btree_path_cache_destroy(void)
 	kmem_cache_destroy(nilfs_btree_path_cache);
 }
 
-static inline struct nilfs_btree_path *
-nilfs_btree_alloc_path(const struct nilfs_btree *btree)
+static inline struct nilfs_btree_path *nilfs_btree_alloc_path(void)
 {
-	return (struct nilfs_btree_path *)
-		kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
+	return kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
 }
 
-static inline void nilfs_btree_free_path(const struct nilfs_btree *btree,
-					 struct nilfs_btree_path *path)
+static inline void nilfs_btree_free_path(struct nilfs_btree_path *path)
 {
 	kmem_cache_free(nilfs_btree_path_cache, path);
 }
 
-static void nilfs_btree_init_path(const struct nilfs_btree *btree,
-				  struct nilfs_btree_path *path)
+static void nilfs_btree_init_path(struct nilfs_btree_path *path)
 {
 	int level;
 
@@ -101,26 +97,13 @@ static void nilfs_btree_init_path(const struct nilfs_btree *btree,
 	}
 }
 
-static void nilfs_btree_clear_path(const struct nilfs_btree *btree,
-				   struct nilfs_btree_path *path)
+static void nilfs_btree_release_path(struct nilfs_btree_path *path)
 {
 	int level;
 
-	for (level = NILFS_BTREE_LEVEL_DATA;
-	     level < NILFS_BTREE_LEVEL_MAX;
-	     level++) {
-		if (path[level].bp_bh != NULL) {
-			brelse(path[level].bp_bh);
-			path[level].bp_bh = NULL;
-		}
-		/* sib_bh is released or deleted by prepare or commit
-		 * operations. */
-		path[level].bp_sib_bh = NULL;
-		path[level].bp_index = 0;
-		path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
-		path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
-		path[level].bp_op = NULL;
-	}
+	for (level = NILFS_BTREE_LEVEL_DATA; level < NILFS_BTREE_LEVEL_MAX;
+	     level++)
+		brelse(path[level].bp_bh);
 }
 
 /*
@@ -148,129 +131,110 @@ static int nilfs_btree_get_new_block(const struct nilfs_btree *btree,
 }
 
 static inline int
-nilfs_btree_node_get_flags(const struct nilfs_btree *btree,
-			   const struct nilfs_btree_node *node)
+nilfs_btree_node_get_flags(const struct nilfs_btree_node *node)
 {
 	return node->bn_flags;
 }
 
 static inline void
-nilfs_btree_node_set_flags(struct nilfs_btree *btree,
-			   struct nilfs_btree_node *node,
-			   int flags)
+nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags)
 {
 	node->bn_flags = flags;
 }
 
-static inline int nilfs_btree_node_root(const struct nilfs_btree *btree,
-					const struct nilfs_btree_node *node)
+static inline int nilfs_btree_node_root(const struct nilfs_btree_node *node)
 {
-	return nilfs_btree_node_get_flags(btree, node) & NILFS_BTREE_NODE_ROOT;
+	return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT;
 }
 
 static inline int
-nilfs_btree_node_get_level(const struct nilfs_btree *btree,
-			   const struct nilfs_btree_node *node)
+nilfs_btree_node_get_level(const struct nilfs_btree_node *node)
 {
 	return node->bn_level;
 }
 
 static inline void
-nilfs_btree_node_set_level(struct nilfs_btree *btree,
-			   struct nilfs_btree_node *node,
-			   int level)
+nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level)
 {
 	node->bn_level = level;
 }
 
 static inline int
-nilfs_btree_node_get_nchildren(const struct nilfs_btree *btree,
-			       const struct nilfs_btree_node *node)
+nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node)
 {
 	return le16_to_cpu(node->bn_nchildren);
 }
 
 static inline void
-nilfs_btree_node_set_nchildren(struct nilfs_btree *btree,
-			       struct nilfs_btree_node *node,
-			       int nchildren)
+nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren)
 {
 	node->bn_nchildren = cpu_to_le16(nchildren);
 }
 
-static inline int
-nilfs_btree_node_size(const struct nilfs_btree *btree)
+static inline int nilfs_btree_node_size(const struct nilfs_btree *btree)
 {
 	return 1 << btree->bt_bmap.b_inode->i_blkbits;
 }
 
 static inline int
-nilfs_btree_node_nchildren_min(const struct nilfs_btree *btree,
-			       const struct nilfs_btree_node *node)
+nilfs_btree_node_nchildren_min(const struct nilfs_btree_node *node,
+			       const struct nilfs_btree *btree)
 {
-	return nilfs_btree_node_root(btree, node) ?
+	return nilfs_btree_node_root(node) ?
 		NILFS_BTREE_ROOT_NCHILDREN_MIN :
 		NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
 }
 
 static inline int
-nilfs_btree_node_nchildren_max(const struct nilfs_btree *btree,
-			       const struct nilfs_btree_node *node)
+nilfs_btree_node_nchildren_max(const struct nilfs_btree_node *node,
+			       const struct nilfs_btree *btree)
 {
-	return nilfs_btree_node_root(btree, node) ?
+	return nilfs_btree_node_root(node) ?
 		NILFS_BTREE_ROOT_NCHILDREN_MAX :
 		NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(btree));
 }
 
 static inline __le64 *
-nilfs_btree_node_dkeys(const struct nilfs_btree *btree,
-		       const struct nilfs_btree_node *node)
+nilfs_btree_node_dkeys(const struct nilfs_btree_node *node)
 {
 	return (__le64 *)((char *)(node + 1) +
-			  (nilfs_btree_node_root(btree, node) ?
+			  (nilfs_btree_node_root(node) ?
 			   0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
 }
 
 static inline __le64 *
-nilfs_btree_node_dptrs(const struct nilfs_btree *btree,
-		       const struct nilfs_btree_node *node)
+nilfs_btree_node_dptrs(const struct nilfs_btree_node *node,
+		       const struct nilfs_btree *btree)
 {
-	return (__le64 *)(nilfs_btree_node_dkeys(btree, node) +
-			  nilfs_btree_node_nchildren_max(btree, node));
+	return (__le64 *)(nilfs_btree_node_dkeys(node) +
+			  nilfs_btree_node_nchildren_max(node, btree));
 }
 
 static inline __u64
-nilfs_btree_node_get_key(const struct nilfs_btree *btree,
-			 const struct nilfs_btree_node *node, int index)
+nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index)
 {
-	return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(btree, node) +
-					index));
+	return nilfs_bmap_dkey_to_key(*(nilfs_btree_node_dkeys(node) + index));
 }
 
 static inline void
-nilfs_btree_node_set_key(struct nilfs_btree *btree,
-			 struct nilfs_btree_node *node, int index, __u64 key)
+nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key)
 {
-	*(nilfs_btree_node_dkeys(btree, node) + index) =
-		nilfs_bmap_key_to_dkey(key);
+	*(nilfs_btree_node_dkeys(node) + index) = nilfs_bmap_key_to_dkey(key);
 }
 
 static inline __u64
 nilfs_btree_node_get_ptr(const struct nilfs_btree *btree,
-			 const struct nilfs_btree_node *node,
-			 int index)
+			 const struct nilfs_btree_node *node, int index)
 {
-	return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(btree, node) +
+	return nilfs_bmap_dptr_to_ptr(*(nilfs_btree_node_dptrs(node, btree) +
 					index));
 }
 
 static inline void
 nilfs_btree_node_set_ptr(struct nilfs_btree *btree,
-			 struct nilfs_btree_node *node,
-			 int index,
-			 __u64 ptr)
+			 struct nilfs_btree_node *node, int index, __u64 ptr)
 {
-	*(nilfs_btree_node_dptrs(btree, node) + index) =
+	*(nilfs_btree_node_dptrs(node, btree) + index) =
 		nilfs_bmap_ptr_to_dptr(ptr);
 }
 
@@ -283,12 +247,12 @@ static void nilfs_btree_node_init(struct nilfs_btree *btree,
 	__le64 *dptrs;
 	int i;
 
-	nilfs_btree_node_set_flags(btree, node, flags);
-	nilfs_btree_node_set_level(btree, node, level);
-	nilfs_btree_node_set_nchildren(btree, node, nchildren);
+	nilfs_btree_node_set_flags(node, flags);
+	nilfs_btree_node_set_level(node, level);
+	nilfs_btree_node_set_nchildren(node, nchildren);
 
-	dkeys = nilfs_btree_node_dkeys(btree, node);
-	dptrs = nilfs_btree_node_dptrs(btree, node);
+	dkeys = nilfs_btree_node_dkeys(node);
+	dptrs = nilfs_btree_node_dptrs(node, btree);
 	for (i = 0; i < nchildren; i++) {
 		dkeys[i] = nilfs_bmap_key_to_dkey(keys[i]);
 		dptrs[i] = nilfs_bmap_ptr_to_dptr(ptrs[i]);
@@ -305,13 +269,13 @@ static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
 	__le64 *ldptrs, *rdptrs;
 	int lnchildren, rnchildren;
 
-	ldkeys = nilfs_btree_node_dkeys(btree, left);
-	ldptrs = nilfs_btree_node_dptrs(btree, left);
-	lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+	ldkeys = nilfs_btree_node_dkeys(left);
+	ldptrs = nilfs_btree_node_dptrs(left, btree);
+	lnchildren = nilfs_btree_node_get_nchildren(left);
 
-	rdkeys = nilfs_btree_node_dkeys(btree, right);
-	rdptrs = nilfs_btree_node_dptrs(btree, right);
-	rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+	rdkeys = nilfs_btree_node_dkeys(right);
+	rdptrs = nilfs_btree_node_dptrs(right, btree);
+	rnchildren = nilfs_btree_node_get_nchildren(right);
 
 	memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
 	memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
@@ -320,8 +284,8 @@ static void nilfs_btree_node_move_left(struct nilfs_btree *btree,
 
 	lnchildren += n;
 	rnchildren -= n;
-	nilfs_btree_node_set_nchildren(btree, left, lnchildren);
-	nilfs_btree_node_set_nchildren(btree, right, rnchildren);
+	nilfs_btree_node_set_nchildren(left, lnchildren);
+	nilfs_btree_node_set_nchildren(right, rnchildren);
 }
 
 /* Assume that the buffer heads corresponding to left and right are locked. */
@@ -334,13 +298,13 @@ static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
 	__le64 *ldptrs, *rdptrs;
 	int lnchildren, rnchildren;
 
-	ldkeys = nilfs_btree_node_dkeys(btree, left);
-	ldptrs = nilfs_btree_node_dptrs(btree, left);
-	lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+	ldkeys = nilfs_btree_node_dkeys(left);
+	ldptrs = nilfs_btree_node_dptrs(left, btree);
+	lnchildren = nilfs_btree_node_get_nchildren(left);
 
-	rdkeys = nilfs_btree_node_dkeys(btree, right);
-	rdptrs = nilfs_btree_node_dptrs(btree, right);
-	rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+	rdkeys = nilfs_btree_node_dkeys(right);
+	rdptrs = nilfs_btree_node_dptrs(right, btree);
+	rnchildren = nilfs_btree_node_get_nchildren(right);
 
 	memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
 	memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
@@ -349,8 +313,8 @@ static void nilfs_btree_node_move_right(struct nilfs_btree *btree,
 
 	lnchildren -= n;
 	rnchildren += n;
-	nilfs_btree_node_set_nchildren(btree, left, lnchildren);
-	nilfs_btree_node_set_nchildren(btree, right, rnchildren);
+	nilfs_btree_node_set_nchildren(left, lnchildren);
+	nilfs_btree_node_set_nchildren(right, rnchildren);
 }
 
 /* Assume that the buffer head corresponding to node is locked. */
@@ -362,9 +326,9 @@ static void nilfs_btree_node_insert(struct nilfs_btree *btree,
 	__le64 *dptrs;
 	int nchildren;
 
-	dkeys = nilfs_btree_node_dkeys(btree, node);
-	dptrs = nilfs_btree_node_dptrs(btree, node);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
+	dkeys = nilfs_btree_node_dkeys(node);
+	dptrs = nilfs_btree_node_dptrs(node, btree);
+	nchildren = nilfs_btree_node_get_nchildren(node);
 	if (index < nchildren) {
 		memmove(dkeys + index + 1, dkeys + index,
 			(nchildren - index) * sizeof(*dkeys));
@@ -374,7 +338,7 @@ static void nilfs_btree_node_insert(struct nilfs_btree *btree,
 	dkeys[index] = nilfs_bmap_key_to_dkey(key);
 	dptrs[index] = nilfs_bmap_ptr_to_dptr(ptr);
 	nchildren++;
-	nilfs_btree_node_set_nchildren(btree, node, nchildren);
+	nilfs_btree_node_set_nchildren(node, nchildren);
 }
 
 /* Assume that the buffer head corresponding to node is locked. */
@@ -388,11 +352,11 @@ static void nilfs_btree_node_delete(struct nilfs_btree *btree,
 	__le64 *dptrs;
 	int nchildren;
 
-	dkeys = nilfs_btree_node_dkeys(btree, node);
-	dptrs = nilfs_btree_node_dptrs(btree, node);
+	dkeys = nilfs_btree_node_dkeys(node);
+	dptrs = nilfs_btree_node_dptrs(node, btree);
 	key = nilfs_bmap_dkey_to_key(dkeys[index]);
 	ptr = nilfs_bmap_dptr_to_ptr(dptrs[index]);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
+	nchildren = nilfs_btree_node_get_nchildren(node);
 	if (keyp != NULL)
 		*keyp = key;
 	if (ptrp != NULL)
@@ -405,11 +369,10 @@ static void nilfs_btree_node_delete(struct nilfs_btree *btree,
 			(nchildren - index - 1) * sizeof(*dptrs));
 	}
 	nchildren--;
-	nilfs_btree_node_set_nchildren(btree, node, nchildren);
+	nilfs_btree_node_set_nchildren(node, nchildren);
 }
 
-static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
-				   const struct nilfs_btree_node *node,
+static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
 				   __u64 key, int *indexp)
 {
 	__u64 nkey;
@@ -417,12 +380,12 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
 
 	/* binary search */
 	low = 0;
-	high = nilfs_btree_node_get_nchildren(btree, node) - 1;
+	high = nilfs_btree_node_get_nchildren(node) - 1;
 	index = 0;
 	s = 0;
 	while (low <= high) {
 		index = (low + high) / 2;
-		nkey = nilfs_btree_node_get_key(btree, node, index);
+		nkey = nilfs_btree_node_get_key(node, index);
 		if (nkey == key) {
 			s = 0;
 			goto out;
@@ -436,9 +399,8 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
 	}
 
 	/* adjust index */
-	if (nilfs_btree_node_get_level(btree, node) >
-	    NILFS_BTREE_LEVEL_NODE_MIN) {
-		if ((s > 0) && (index > 0))
+	if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) {
+		if (s > 0 && index > 0)
 			index--;
 	} else if (s < 0)
 		index++;
@@ -456,25 +418,20 @@ nilfs_btree_get_root(const struct nilfs_btree *btree)
 }
 
 static inline struct nilfs_btree_node *
-nilfs_btree_get_nonroot_node(const struct nilfs_btree *btree,
-			     const struct nilfs_btree_path *path,
-			     int level)
+nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level)
 {
 	return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
 }
 
 static inline struct nilfs_btree_node *
-nilfs_btree_get_sib_node(const struct nilfs_btree *btree,
-			 const struct nilfs_btree_path *path,
-			 int level)
+nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level)
 {
 	return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
 }
 
 static inline int nilfs_btree_height(const struct nilfs_btree *btree)
 {
-	return nilfs_btree_node_get_level(btree, nilfs_btree_get_root(btree))
-		+ 1;
+	return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1;
 }
 
 static inline struct nilfs_btree_node *
@@ -484,7 +441,7 @@ nilfs_btree_get_node(const struct nilfs_btree *btree,
 {
 	return (level == nilfs_btree_height(btree) - 1) ?
 		nilfs_btree_get_root(btree) :
-		nilfs_btree_get_nonroot_node(btree, path, level);
+		nilfs_btree_get_nonroot_node(path, level);
 }
 
 static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
@@ -496,12 +453,11 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
 	int level, index, found, ret;
 
 	node = nilfs_btree_get_root(btree);
-	level = nilfs_btree_node_get_level(btree, node);
-	if ((level < minlevel) ||
-	    (nilfs_btree_node_get_nchildren(btree, node) <= 0))
+	level = nilfs_btree_node_get_level(node);
+	if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0)
 		return -ENOENT;
 
-	found = nilfs_btree_node_lookup(btree, node, key, &index);
+	found = nilfs_btree_node_lookup(node, key, &index);
 	ptr = nilfs_btree_node_get_ptr(btree, node, index);
 	path[level].bp_bh = NULL;
 	path[level].bp_index = index;
@@ -510,14 +466,13 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
 		ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
 		if (ret < 0)
 			return ret;
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
-		BUG_ON(level != nilfs_btree_node_get_level(btree, node));
+		node = nilfs_btree_get_nonroot_node(path, level);
+		BUG_ON(level != nilfs_btree_node_get_level(node));
 		if (!found)
-			found = nilfs_btree_node_lookup(btree, node, key,
-							&index);
+			found = nilfs_btree_node_lookup(node, key, &index);
 		else
 			index = 0;
-		if (index < nilfs_btree_node_nchildren_max(btree, node))
+		if (index < nilfs_btree_node_nchildren_max(node, btree))
 			ptr = nilfs_btree_node_get_ptr(btree, node, index);
 		else {
 			WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
@@ -544,10 +499,10 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
 	int index, level, ret;
 
 	node = nilfs_btree_get_root(btree);
-	index = nilfs_btree_node_get_nchildren(btree, node) - 1;
+	index = nilfs_btree_node_get_nchildren(node) - 1;
 	if (index < 0)
 		return -ENOENT;
-	level = nilfs_btree_node_get_level(btree, node);
+	level = nilfs_btree_node_get_level(node);
 	ptr = nilfs_btree_node_get_ptr(btree, node, index);
 	path[level].bp_bh = NULL;
 	path[level].bp_index = index;
@@ -556,15 +511,15 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_btree *btree,
 		ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
 		if (ret < 0)
 			return ret;
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
-		BUG_ON(level != nilfs_btree_node_get_level(btree, node));
-		index = nilfs_btree_node_get_nchildren(btree, node) - 1;
+		node = nilfs_btree_get_nonroot_node(path, level);
+		BUG_ON(level != nilfs_btree_node_get_level(node));
+		index = nilfs_btree_node_get_nchildren(node) - 1;
 		ptr = nilfs_btree_node_get_ptr(btree, node, index);
 		path[level].bp_index = index;
 	}
 
 	if (keyp != NULL)
-		*keyp = nilfs_btree_node_get_key(btree, node, index);
+		*keyp = nilfs_btree_node_get_key(node, index);
 	if (ptrp != NULL)
 		*ptrp = ptr;
 
@@ -580,18 +535,18 @@ static int nilfs_btree_lookup(const struct nilfs_bmap *bmap,
 	int ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
 
 	if (ptrp != NULL)
 		*ptrp = ptr;
 
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 
 	return ret;
 }
@@ -608,10 +563,10 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
 	int level = NILFS_BTREE_LEVEL_NODE_MIN;
 	int ret, cnt, index, maxlevel;
 
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 	ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level);
 	if (ret < 0)
 		goto out;
@@ -631,8 +586,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
 	node = nilfs_btree_get_node(btree, path, level);
 	index = path[level].bp_index + 1;
 	for (;;) {
-		while (index < nilfs_btree_node_get_nchildren(btree, node)) {
-			if (nilfs_btree_node_get_key(btree, node, index) !=
+		while (index < nilfs_btree_node_get_nchildren(node)) {
+			if (nilfs_btree_node_get_key(node, index) !=
 			    key + cnt)
 				goto end;
 			ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
@@ -653,8 +608,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
 		/* look-up right sibling node */
 		node = nilfs_btree_get_node(btree, path, level + 1);
 		index = path[level + 1].bp_index + 1;
-		if (index >= nilfs_btree_node_get_nchildren(btree, node) ||
-		    nilfs_btree_node_get_key(btree, node, index) != key + cnt)
+		if (index >= nilfs_btree_node_get_nchildren(node) ||
+		    nilfs_btree_node_get_key(node, index) != key + cnt)
 			break;
 		ptr2 = nilfs_btree_node_get_ptr(btree, node, index);
 		path[level + 1].bp_index = index;
@@ -664,7 +619,7 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
 		ret = nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh);
 		if (ret < 0)
 			goto out;
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
+		node = nilfs_btree_get_nonroot_node(path, level);
 		index = 0;
 		path[level].bp_index = index;
 	}
@@ -672,8 +627,8 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *bmap,
 	*ptrp = ptr;
 	ret = cnt;
  out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 	return ret;
 }
 
@@ -685,9 +640,7 @@ static void nilfs_btree_promote_key(struct nilfs_btree *btree,
 		do {
 			lock_buffer(path[level].bp_bh);
 			nilfs_btree_node_set_key(
-				btree,
-				nilfs_btree_get_nonroot_node(
-					btree, path, level),
+				nilfs_btree_get_nonroot_node(path, level),
 				path[level].bp_index, key);
 			if (!buffer_dirty(path[level].bp_bh))
 				nilfs_btnode_mark_dirty(path[level].bp_bh);
@@ -698,8 +651,7 @@ static void nilfs_btree_promote_key(struct nilfs_btree *btree,
 
 	/* root */
 	if (level == nilfs_btree_height(btree) - 1) {
-		nilfs_btree_node_set_key(btree,
-					 nilfs_btree_get_root(btree),
+		nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
 					 path[level].bp_index, key);
 	}
 }
@@ -712,7 +664,7 @@ static void nilfs_btree_do_insert(struct nilfs_btree *btree,
 
 	if (level < nilfs_btree_height(btree) - 1) {
 		lock_buffer(path[level].bp_bh);
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
+		node = nilfs_btree_get_nonroot_node(path, level);
 		nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
 					path[level].bp_index);
 		if (!buffer_dirty(path[level].bp_bh))
@@ -721,8 +673,8 @@ static void nilfs_btree_do_insert(struct nilfs_btree *btree,
 
 		if (path[level].bp_index == 0)
 			nilfs_btree_promote_key(btree, path, level + 1,
-						nilfs_btree_node_get_key(
-							btree, node, 0));
+						nilfs_btree_node_get_key(node,
+									 0));
 	} else {
 		node = nilfs_btree_get_root(btree);
 		nilfs_btree_node_insert(btree, node, *keyp, *ptrp,
@@ -740,10 +692,10 @@ static void nilfs_btree_carry_left(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	left = nilfs_btree_get_sib_node(btree, path, level);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
-	lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	left = nilfs_btree_get_sib_node(path, level);
+	nchildren = nilfs_btree_node_get_nchildren(node);
+	lnchildren = nilfs_btree_node_get_nchildren(left);
 	move = 0;
 
 	n = (nchildren + lnchildren + 1) / 2 - lnchildren;
@@ -764,7 +716,7 @@ static void nilfs_btree_carry_left(struct nilfs_btree *btree,
 	unlock_buffer(path[level].bp_sib_bh);
 
 	nilfs_btree_promote_key(btree, path, level + 1,
-				nilfs_btree_node_get_key(btree, node, 0));
+				nilfs_btree_node_get_key(node, 0));
 
 	if (move) {
 		brelse(path[level].bp_bh);
@@ -791,10 +743,10 @@ static void nilfs_btree_carry_right(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	right = nilfs_btree_get_sib_node(btree, path, level);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
-	rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	right = nilfs_btree_get_sib_node(path, level);
+	nchildren = nilfs_btree_node_get_nchildren(node);
+	rnchildren = nilfs_btree_node_get_nchildren(right);
 	move = 0;
 
 	n = (nchildren + rnchildren + 1) / 2 - rnchildren;
@@ -816,15 +768,14 @@ static void nilfs_btree_carry_right(struct nilfs_btree *btree,
 
 	path[level + 1].bp_index++;
 	nilfs_btree_promote_key(btree, path, level + 1,
-				nilfs_btree_node_get_key(btree, right, 0));
+				nilfs_btree_node_get_key(right, 0));
 	path[level + 1].bp_index--;
 
 	if (move) {
 		brelse(path[level].bp_bh);
 		path[level].bp_bh = path[level].bp_sib_bh;
 		path[level].bp_sib_bh = NULL;
-		path[level].bp_index -=
-			nilfs_btree_node_get_nchildren(btree, node);
+		path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
 		path[level + 1].bp_index++;
 	} else {
 		brelse(path[level].bp_sib_bh);
@@ -846,9 +797,9 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	right = nilfs_btree_get_sib_node(btree, path, level);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	right = nilfs_btree_get_sib_node(path, level);
+	nchildren = nilfs_btree_node_get_nchildren(node);
 	move = 0;
 
 	n = (nchildren + 1) / 2;
@@ -867,16 +818,15 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
 	unlock_buffer(path[level].bp_bh);
 	unlock_buffer(path[level].bp_sib_bh);
 
-	newkey = nilfs_btree_node_get_key(btree, right, 0);
+	newkey = nilfs_btree_node_get_key(right, 0);
 	newptr = path[level].bp_newreq.bpr_ptr;
 
 	if (move) {
-		path[level].bp_index -=
-			nilfs_btree_node_get_nchildren(btree, node);
+		path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
 		nilfs_btree_node_insert(btree, right, *keyp, *ptrp,
 					path[level].bp_index);
 
-		*keyp = nilfs_btree_node_get_key(btree, right, 0);
+		*keyp = nilfs_btree_node_get_key(right, 0);
 		*ptrp = path[level].bp_newreq.bpr_ptr;
 
 		brelse(path[level].bp_bh);
@@ -885,7 +835,7 @@ static void nilfs_btree_split(struct nilfs_btree *btree,
 	} else {
 		nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
 
-		*keyp = nilfs_btree_node_get_key(btree, right, 0);
+		*keyp = nilfs_btree_node_get_key(right, 0);
 		*ptrp = path[level].bp_newreq.bpr_ptr;
 
 		brelse(path[level].bp_sib_bh);
@@ -905,12 +855,12 @@ static void nilfs_btree_grow(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_sib_bh);
 
 	root = nilfs_btree_get_root(btree);
-	child = nilfs_btree_get_sib_node(btree, path, level);
+	child = nilfs_btree_get_sib_node(path, level);
 
-	n = nilfs_btree_node_get_nchildren(btree, root);
+	n = nilfs_btree_node_get_nchildren(root);
 
 	nilfs_btree_node_move_right(btree, root, child, n);
-	nilfs_btree_node_set_level(btree, root, level + 1);
+	nilfs_btree_node_set_level(root, level + 1);
 
 	if (!buffer_dirty(path[level].bp_sib_bh))
 		nilfs_btnode_mark_dirty(path[level].bp_sib_bh);
@@ -922,7 +872,7 @@ static void nilfs_btree_grow(struct nilfs_btree *btree,
 
 	nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
 
-	*keyp = nilfs_btree_node_get_key(btree, child, 0);
+	*keyp = nilfs_btree_node_get_key(child, 0);
 	*ptrp = path[level].bp_newreq.bpr_ptr;
 }
 
@@ -990,26 +940,29 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 	struct nilfs_btree_node *node, *parent, *sib;
 	__u64 sibptr;
 	int pindex, level, ret;
+	struct inode *dat = NULL;
 
 	stats->bs_nblocks = 0;
 	level = NILFS_BTREE_LEVEL_DATA;
 
 	/* allocate a new ptr for data block */
-	if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
+	if (NILFS_BMAP_USE_VBN(&btree->bt_bmap)) {
 		path[level].bp_newreq.bpr_ptr =
 			nilfs_btree_find_target_v(btree, path, key);
+		dat = nilfs_bmap_get_dat(&btree->bt_bmap);
+	}
 
 	ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
-					   &path[level].bp_newreq);
+					   &path[level].bp_newreq, dat);
 	if (ret < 0)
 		goto err_out_data;
 
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN;
 	     level < nilfs_btree_height(btree) - 1;
 	     level++) {
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
-		if (nilfs_btree_node_get_nchildren(btree, node) <
-		    nilfs_btree_node_nchildren_max(btree, node)) {
+		node = nilfs_btree_get_nonroot_node(path, level);
+		if (nilfs_btree_node_get_nchildren(node) <
+		    nilfs_btree_node_nchildren_max(node, btree)) {
 			path[level].bp_op = nilfs_btree_do_insert;
 			stats->bs_nblocks++;
 			goto out;
@@ -1026,8 +979,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 			if (ret < 0)
 				goto err_out_child_node;
 			sib = (struct nilfs_btree_node *)bh->b_data;
-			if (nilfs_btree_node_get_nchildren(btree, sib) <
-			    nilfs_btree_node_nchildren_max(btree, sib)) {
+			if (nilfs_btree_node_get_nchildren(sib) <
+			    nilfs_btree_node_nchildren_max(sib, btree)) {
 				path[level].bp_sib_bh = bh;
 				path[level].bp_op = nilfs_btree_carry_left;
 				stats->bs_nblocks++;
@@ -1038,15 +991,15 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
 		/* right sibling */
 		if (pindex <
-		    nilfs_btree_node_get_nchildren(btree, parent) - 1) {
+		    nilfs_btree_node_get_nchildren(parent) - 1) {
 			sibptr = nilfs_btree_node_get_ptr(btree, parent,
 							  pindex + 1);
 			ret = nilfs_btree_get_block(btree, sibptr, &bh);
 			if (ret < 0)
 				goto err_out_child_node;
 			sib = (struct nilfs_btree_node *)bh->b_data;
-			if (nilfs_btree_node_get_nchildren(btree, sib) <
-			    nilfs_btree_node_nchildren_max(btree, sib)) {
+			if (nilfs_btree_node_get_nchildren(sib) <
+			    nilfs_btree_node_nchildren_max(sib, btree)) {
 				path[level].bp_sib_bh = bh;
 				path[level].bp_op = nilfs_btree_carry_right;
 				stats->bs_nblocks++;
@@ -1059,7 +1012,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 		path[level].bp_newreq.bpr_ptr =
 			path[level - 1].bp_newreq.bpr_ptr + 1;
 		ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
-						   &path[level].bp_newreq);
+						   &path[level].bp_newreq, dat);
 		if (ret < 0)
 			goto err_out_child_node;
 		ret = nilfs_btree_get_new_block(btree,
@@ -1081,8 +1034,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
 	/* root */
 	node = nilfs_btree_get_root(btree);
-	if (nilfs_btree_node_get_nchildren(btree, node) <
-	    nilfs_btree_node_nchildren_max(btree, node)) {
+	if (nilfs_btree_node_get_nchildren(node) <
+	    nilfs_btree_node_nchildren_max(node, btree)) {
 		path[level].bp_op = nilfs_btree_do_insert;
 		stats->bs_nblocks++;
 		goto out;
@@ -1091,7 +1044,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 	/* grow */
 	path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
 	ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
-					   &path[level].bp_newreq);
+					   &path[level].bp_newreq, dat);
 	if (ret < 0)
 		goto err_out_child_node;
 	ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
@@ -1119,16 +1072,18 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
 	/* error */
  err_out_curr_node:
-	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
+	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq,
+				   dat);
  err_out_child_node:
 	for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
 		nilfs_btnode_delete(path[level].bp_sib_bh);
 		nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap,
-					   &path[level].bp_newreq);
+					   &path[level].bp_newreq, dat);
 
 	}
 
-	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
+	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq,
+				   dat);
  err_out_data:
 	*levelp = level;
 	stats->bs_nblocks = 0;
@@ -1139,16 +1094,19 @@ static void nilfs_btree_commit_insert(struct nilfs_btree *btree,
 				      struct nilfs_btree_path *path,
 				      int maxlevel, __u64 key, __u64 ptr)
 {
+	struct inode *dat = NULL;
 	int level;
 
 	set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
 	ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
-	if (NILFS_BMAP_USE_VBN(&btree->bt_bmap))
+	if (NILFS_BMAP_USE_VBN(&btree->bt_bmap)) {
 		nilfs_btree_set_target_v(btree, key, ptr);
+		dat = nilfs_bmap_get_dat(&btree->bt_bmap);
+	}
 
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
 		nilfs_bmap_commit_alloc_ptr(&btree->bt_bmap,
-					    &path[level - 1].bp_newreq);
+					    &path[level - 1].bp_newreq, dat);
 		path[level].bp_op(btree, path, level, &key, &ptr);
 	}
 
@@ -1164,10 +1122,10 @@ static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 	int level, ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	ret = nilfs_btree_do_lookup(btree, path, key, NULL,
 				    NILFS_BTREE_LEVEL_NODE_MIN);
@@ -1184,8 +1142,8 @@ static int nilfs_btree_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 	nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 
  out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 	return ret;
 }
 
@@ -1197,7 +1155,7 @@ static void nilfs_btree_do_delete(struct nilfs_btree *btree,
 
 	if (level < nilfs_btree_height(btree) - 1) {
 		lock_buffer(path[level].bp_bh);
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
+		node = nilfs_btree_get_nonroot_node(path, level);
 		nilfs_btree_node_delete(btree, node, keyp, ptrp,
 					path[level].bp_index);
 		if (!buffer_dirty(path[level].bp_bh))
@@ -1205,7 +1163,7 @@ static void nilfs_btree_do_delete(struct nilfs_btree *btree,
 		unlock_buffer(path[level].bp_bh);
 		if (path[level].bp_index == 0)
 			nilfs_btree_promote_key(btree, path, level + 1,
-				nilfs_btree_node_get_key(btree, node, 0));
+				nilfs_btree_node_get_key(node, 0));
 	} else {
 		node = nilfs_btree_get_root(btree);
 		nilfs_btree_node_delete(btree, node, keyp, ptrp,
@@ -1225,10 +1183,10 @@ static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	left = nilfs_btree_get_sib_node(btree, path, level);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
-	lnchildren = nilfs_btree_node_get_nchildren(btree, left);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	left = nilfs_btree_get_sib_node(path, level);
+	nchildren = nilfs_btree_node_get_nchildren(node);
+	lnchildren = nilfs_btree_node_get_nchildren(left);
 
 	n = (nchildren + lnchildren) / 2 - nchildren;
 
@@ -1243,7 +1201,7 @@ static void nilfs_btree_borrow_left(struct nilfs_btree *btree,
 	unlock_buffer(path[level].bp_sib_bh);
 
 	nilfs_btree_promote_key(btree, path, level + 1,
-				nilfs_btree_node_get_key(btree, node, 0));
+				nilfs_btree_node_get_key(node, 0));
 
 	brelse(path[level].bp_sib_bh);
 	path[level].bp_sib_bh = NULL;
@@ -1262,10 +1220,10 @@ static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	right = nilfs_btree_get_sib_node(btree, path, level);
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
-	rnchildren = nilfs_btree_node_get_nchildren(btree, right);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	right = nilfs_btree_get_sib_node(path, level);
+	nchildren = nilfs_btree_node_get_nchildren(node);
+	rnchildren = nilfs_btree_node_get_nchildren(right);
 
 	n = (nchildren + rnchildren) / 2 - nchildren;
 
@@ -1281,7 +1239,7 @@ static void nilfs_btree_borrow_right(struct nilfs_btree *btree,
 
 	path[level + 1].bp_index++;
 	nilfs_btree_promote_key(btree, path, level + 1,
-				nilfs_btree_node_get_key(btree, right, 0));
+				nilfs_btree_node_get_key(right, 0));
 	path[level + 1].bp_index--;
 
 	brelse(path[level].bp_sib_bh);
@@ -1300,10 +1258,10 @@ static void nilfs_btree_concat_left(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	left = nilfs_btree_get_sib_node(btree, path, level);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	left = nilfs_btree_get_sib_node(path, level);
 
-	n = nilfs_btree_node_get_nchildren(btree, node);
+	n = nilfs_btree_node_get_nchildren(node);
 
 	nilfs_btree_node_move_left(btree, left, node, n);
 
@@ -1316,7 +1274,7 @@ static void nilfs_btree_concat_left(struct nilfs_btree *btree,
 	nilfs_btnode_delete(path[level].bp_bh);
 	path[level].bp_bh = path[level].bp_sib_bh;
 	path[level].bp_sib_bh = NULL;
-	path[level].bp_index += nilfs_btree_node_get_nchildren(btree, left);
+	path[level].bp_index += nilfs_btree_node_get_nchildren(left);
 }
 
 static void nilfs_btree_concat_right(struct nilfs_btree *btree,
@@ -1331,10 +1289,10 @@ static void nilfs_btree_concat_right(struct nilfs_btree *btree,
 	lock_buffer(path[level].bp_bh);
 	lock_buffer(path[level].bp_sib_bh);
 
-	node = nilfs_btree_get_nonroot_node(btree, path, level);
-	right = nilfs_btree_get_sib_node(btree, path, level);
+	node = nilfs_btree_get_nonroot_node(path, level);
+	right = nilfs_btree_get_sib_node(path, level);
 
-	n = nilfs_btree_node_get_nchildren(btree, right);
+	n = nilfs_btree_node_get_nchildren(right);
 
 	nilfs_btree_node_move_left(btree, node, right, n);
 
@@ -1360,11 +1318,11 @@ static void nilfs_btree_shrink(struct nilfs_btree *btree,
 
 	lock_buffer(path[level].bp_bh);
 	root = nilfs_btree_get_root(btree);
-	child = nilfs_btree_get_nonroot_node(btree, path, level);
+	child = nilfs_btree_get_nonroot_node(path, level);
 
 	nilfs_btree_node_delete(btree, root, NULL, NULL, 0);
-	nilfs_btree_node_set_level(btree, root, level);
-	n = nilfs_btree_node_get_nchildren(btree, child);
+	nilfs_btree_node_set_level(root, level);
+	n = nilfs_btree_node_get_nchildren(child);
 	nilfs_btree_node_move_left(btree, root, child, n);
 	unlock_buffer(path[level].bp_bh);
 
@@ -1376,7 +1334,8 @@ static void nilfs_btree_shrink(struct nilfs_btree *btree,
 static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 				      struct nilfs_btree_path *path,
 				      int *levelp,
-				      struct nilfs_bmap_stats *stats)
+				      struct nilfs_bmap_stats *stats,
+				      struct inode *dat)
 {
 	struct buffer_head *bh;
 	struct nilfs_btree_node *node, *parent, *sib;
@@ -1388,17 +1347,17 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN;
 	     level < nilfs_btree_height(btree) - 1;
 	     level++) {
-		node = nilfs_btree_get_nonroot_node(btree, path, level);
+		node = nilfs_btree_get_nonroot_node(path, level);
 		path[level].bp_oldreq.bpr_ptr =
 			nilfs_btree_node_get_ptr(btree, node,
 						 path[level].bp_index);
 		ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
-						 &path[level].bp_oldreq);
+						 &path[level].bp_oldreq, dat);
 		if (ret < 0)
 			goto err_out_child_node;
 
-		if (nilfs_btree_node_get_nchildren(btree, node) >
-		    nilfs_btree_node_nchildren_min(btree, node)) {
+		if (nilfs_btree_node_get_nchildren(node) >
+		    nilfs_btree_node_nchildren_min(node, btree)) {
 			path[level].bp_op = nilfs_btree_do_delete;
 			stats->bs_nblocks++;
 			goto out;
@@ -1415,8 +1374,8 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 			if (ret < 0)
 				goto err_out_curr_node;
 			sib = (struct nilfs_btree_node *)bh->b_data;
-			if (nilfs_btree_node_get_nchildren(btree, sib) >
-			    nilfs_btree_node_nchildren_min(btree, sib)) {
+			if (nilfs_btree_node_get_nchildren(sib) >
+			    nilfs_btree_node_nchildren_min(sib, btree)) {
 				path[level].bp_sib_bh = bh;
 				path[level].bp_op = nilfs_btree_borrow_left;
 				stats->bs_nblocks++;
@@ -1428,7 +1387,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 				/* continue; */
 			}
 		} else if (pindex <
-			   nilfs_btree_node_get_nchildren(btree, parent) - 1) {
+			   nilfs_btree_node_get_nchildren(parent) - 1) {
 			/* right sibling */
 			sibptr = nilfs_btree_node_get_ptr(btree, parent,
 							  pindex + 1);
@@ -1436,8 +1395,8 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 			if (ret < 0)
 				goto err_out_curr_node;
 			sib = (struct nilfs_btree_node *)bh->b_data;
-			if (nilfs_btree_node_get_nchildren(btree, sib) >
-			    nilfs_btree_node_nchildren_min(btree, sib)) {
+			if (nilfs_btree_node_get_nchildren(sib) >
+			    nilfs_btree_node_nchildren_min(sib, btree)) {
 				path[level].bp_sib_bh = bh;
 				path[level].bp_op = nilfs_btree_borrow_right;
 				stats->bs_nblocks++;
@@ -1452,7 +1411,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 			/* no siblings */
 			/* the only child of the root node */
 			WARN_ON(level != nilfs_btree_height(btree) - 2);
-			if (nilfs_btree_node_get_nchildren(btree, node) - 1 <=
+			if (nilfs_btree_node_get_nchildren(node) - 1 <=
 			    NILFS_BTREE_ROOT_NCHILDREN_MAX) {
 				path[level].bp_op = nilfs_btree_shrink;
 				stats->bs_nblocks += 2;
@@ -1471,7 +1430,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 		nilfs_btree_node_get_ptr(btree, node, path[level].bp_index);
 
 	ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
-					 &path[level].bp_oldreq);
+					 &path[level].bp_oldreq, dat);
 	if (ret < 0)
 		goto err_out_child_node;
 
@@ -1486,12 +1445,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 
 	/* error */
  err_out_curr_node:
-	nilfs_bmap_abort_end_ptr(&btree->bt_bmap, &path[level].bp_oldreq);
+	nilfs_bmap_abort_end_ptr(&btree->bt_bmap, &path[level].bp_oldreq, dat);
  err_out_child_node:
 	for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
 		brelse(path[level].bp_sib_bh);
 		nilfs_bmap_abort_end_ptr(&btree->bt_bmap,
-					 &path[level].bp_oldreq);
+					 &path[level].bp_oldreq, dat);
 	}
 	*levelp = level;
 	stats->bs_nblocks = 0;
@@ -1500,13 +1459,13 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 
 static void nilfs_btree_commit_delete(struct nilfs_btree *btree,
 				      struct nilfs_btree_path *path,
-				      int maxlevel)
+				      int maxlevel, struct inode *dat)
 {
 	int level;
 
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
 		nilfs_bmap_commit_end_ptr(&btree->bt_bmap,
-					  &path[level].bp_oldreq);
+					  &path[level].bp_oldreq, dat);
 		path[level].bp_op(btree, path, level, NULL, NULL);
 	}
 
@@ -1520,27 +1479,32 @@ static int nilfs_btree_delete(struct nilfs_bmap *bmap, __u64 key)
 	struct nilfs_btree *btree;
 	struct nilfs_btree_path *path;
 	struct nilfs_bmap_stats stats;
+	struct inode *dat;
 	int level, ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 	ret = nilfs_btree_do_lookup(btree, path, key, NULL,
 				    NILFS_BTREE_LEVEL_NODE_MIN);
 	if (ret < 0)
 		goto out;
 
-	ret = nilfs_btree_prepare_delete(btree, path, &level, &stats);
+
+	dat = NILFS_BMAP_USE_VBN(&btree->bt_bmap) ?
+		nilfs_bmap_get_dat(&btree->bt_bmap) : NULL;
+
+	ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
 	if (ret < 0)
 		goto out;
-	nilfs_btree_commit_delete(btree, path, level);
+	nilfs_btree_commit_delete(btree, path, level, dat);
 	nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 
 out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 	return ret;
 }
 
@@ -1551,15 +1515,15 @@ static int nilfs_btree_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
 	int ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
 
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 
 	return ret;
 }
@@ -1581,7 +1545,7 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
 		node = root;
 		break;
 	case 3:
-		nchildren = nilfs_btree_node_get_nchildren(btree, root);
+		nchildren = nilfs_btree_node_get_nchildren(root);
 		if (nchildren > 1)
 			return 0;
 		ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
@@ -1594,10 +1558,10 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *bmap, __u64 key)
 		return 0;
 	}
 
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
-	maxkey = nilfs_btree_node_get_key(btree, node, nchildren - 1);
+	nchildren = nilfs_btree_node_get_nchildren(node);
+	maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
 	nextmaxkey = (nchildren > 1) ?
-		nilfs_btree_node_get_key(btree, node, nchildren - 2) : 0;
+		nilfs_btree_node_get_key(node, nchildren - 2) : 0;
 	if (bh != NULL)
 		brelse(bh);
 
@@ -1623,7 +1587,7 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
 		node = root;
 		break;
 	case 3:
-		nchildren = nilfs_btree_node_get_nchildren(btree, root);
+		nchildren = nilfs_btree_node_get_nchildren(root);
 		WARN_ON(nchildren > 1);
 		ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
 		ret = nilfs_btree_get_block(btree, ptr, &bh);
@@ -1636,11 +1600,11 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
 		return -EINVAL;
 	}
 
-	nchildren = nilfs_btree_node_get_nchildren(btree, node);
+	nchildren = nilfs_btree_node_get_nchildren(node);
 	if (nchildren < nitems)
 		nitems = nchildren;
-	dkeys = nilfs_btree_node_dkeys(btree, node);
-	dptrs = nilfs_btree_node_dptrs(btree, node);
+	dkeys = nilfs_btree_node_dkeys(node);
+	dptrs = nilfs_btree_node_dptrs(node, btree);
 	for (i = 0; i < nitems; i++) {
 		keys[i] = nilfs_bmap_dkey_to_key(dkeys[i]);
 		ptrs[i] = nilfs_bmap_dptr_to_ptr(dptrs[i]);
@@ -1660,18 +1624,20 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 				       struct nilfs_bmap_stats *stats)
 {
 	struct buffer_head *bh;
-	struct nilfs_btree *btree;
+	struct nilfs_btree *btree = (struct nilfs_btree *)bmap;
+	struct inode *dat = NULL;
 	int ret;
 
-	btree = (struct nilfs_btree *)bmap;
 	stats->bs_nblocks = 0;
 
 	/* for data */
 	/* cannot find near ptr */
-	if (NILFS_BMAP_USE_VBN(bmap))
+	if (NILFS_BMAP_USE_VBN(bmap)) {
 		dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
+		dat = nilfs_bmap_get_dat(bmap);
+	}
 
-	ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq);
+	ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq, dat);
 	if (ret < 0)
 		return ret;
 
@@ -1679,7 +1645,7 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 	stats->bs_nblocks++;
 	if (nreq != NULL) {
 		nreq->bpr_ptr = dreq->bpr_ptr + 1;
-		ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq);
+		ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq, dat);
 		if (ret < 0)
 			goto err_out_dreq;
 
@@ -1696,9 +1662,9 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 
 	/* error */
  err_out_nreq:
-	nilfs_bmap_abort_alloc_ptr(bmap, nreq);
+	nilfs_bmap_abort_alloc_ptr(bmap, nreq, dat);
  err_out_dreq:
-	nilfs_bmap_abort_alloc_ptr(bmap, dreq);
+	nilfs_bmap_abort_alloc_ptr(bmap, dreq, dat);
 	stats->bs_nblocks = 0;
 	return ret;
 
@@ -1713,8 +1679,9 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
 				      union nilfs_bmap_ptr_req *nreq,
 				      struct buffer_head *bh)
 {
-	struct nilfs_btree *btree;
+	struct nilfs_btree *btree = (struct nilfs_btree *)bmap;
 	struct nilfs_btree_node *node;
+	struct inode *dat;
 	__u64 tmpptr;
 
 	/* free resources */
@@ -1725,11 +1692,11 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
 	set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
 
 	/* convert and insert */
-	btree = (struct nilfs_btree *)bmap;
+	dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
 	nilfs_btree_init(bmap);
 	if (nreq != NULL) {
-		nilfs_bmap_commit_alloc_ptr(bmap, dreq);
-		nilfs_bmap_commit_alloc_ptr(bmap, nreq);
+		nilfs_bmap_commit_alloc_ptr(bmap, dreq, dat);
+		nilfs_bmap_commit_alloc_ptr(bmap, nreq, dat);
 
 		/* create child node at level 1 */
 		lock_buffer(bh);
@@ -1751,7 +1718,7 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
 		nilfs_btree_node_init(btree, node, NILFS_BTREE_NODE_ROOT,
 				      2, 1, &keys[0], &tmpptr);
 	} else {
-		nilfs_bmap_commit_alloc_ptr(bmap, dreq);
+		nilfs_bmap_commit_alloc_ptr(bmap, dreq, dat);
 
 		/* create root node at level 1 */
 		node = nilfs_btree_get_root(btree);
@@ -1822,7 +1789,7 @@ static int nilfs_btree_propagate_p(struct nilfs_btree *btree,
 
 static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
 					struct nilfs_btree_path *path,
-					int level)
+					int level, struct inode *dat)
 {
 	struct nilfs_btree_node *parent;
 	int ret;
@@ -1832,9 +1799,8 @@ static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
 		nilfs_btree_node_get_ptr(btree, parent,
 					 path[level + 1].bp_index);
 	path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
-	ret = nilfs_bmap_prepare_update_v(&btree->bt_bmap,
-					  &path[level].bp_oldreq,
-					  &path[level].bp_newreq);
+	ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
+				       &path[level].bp_newreq.bpr_req);
 	if (ret < 0)
 		return ret;
 
@@ -1846,9 +1812,9 @@ static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
 			&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
 			&path[level].bp_ctxt);
 		if (ret < 0) {
-			nilfs_bmap_abort_update_v(&btree->bt_bmap,
-						  &path[level].bp_oldreq,
-						  &path[level].bp_newreq);
+			nilfs_dat_abort_update(dat,
+					       &path[level].bp_oldreq.bpr_req,
+					       &path[level].bp_newreq.bpr_req);
 			return ret;
 		}
 	}
@@ -1858,13 +1824,13 @@ static int nilfs_btree_prepare_update_v(struct nilfs_btree *btree,
 
 static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
 					struct nilfs_btree_path *path,
-					int level)
+					int level, struct inode *dat)
 {
 	struct nilfs_btree_node *parent;
 
-	nilfs_bmap_commit_update_v(&btree->bt_bmap,
-				   &path[level].bp_oldreq,
-				   &path[level].bp_newreq);
+	nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
+				&path[level].bp_newreq.bpr_req,
+				btree->bt_bmap.b_ptr_type == NILFS_BMAP_PTR_VS);
 
 	if (buffer_nilfs_node(path[level].bp_bh)) {
 		nilfs_btnode_commit_change_key(
@@ -1881,11 +1847,10 @@ static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
 
 static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
 				       struct nilfs_btree_path *path,
-				       int level)
+				       int level, struct inode *dat)
 {
-	nilfs_bmap_abort_update_v(&btree->bt_bmap,
-				  &path[level].bp_oldreq,
-				  &path[level].bp_newreq);
+	nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
+			       &path[level].bp_newreq.bpr_req);
 	if (buffer_nilfs_node(path[level].bp_bh))
 		nilfs_btnode_abort_change_key(
 			&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
@@ -1894,14 +1859,14 @@ static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
 
 static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
 					   struct nilfs_btree_path *path,
-					   int minlevel,
-					   int *maxlevelp)
+					   int minlevel, int *maxlevelp,
+					   struct inode *dat)
 {
 	int level, ret;
 
 	level = minlevel;
 	if (!buffer_nilfs_volatile(path[level].bp_bh)) {
-		ret = nilfs_btree_prepare_update_v(btree, path, level);
+		ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
 		if (ret < 0)
 			return ret;
 	}
@@ -1909,7 +1874,7 @@ static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
 	       !buffer_dirty(path[level].bp_bh)) {
 
 		WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
-		ret = nilfs_btree_prepare_update_v(btree, path, level);
+		ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
 		if (ret < 0)
 			goto out;
 	}
@@ -1921,39 +1886,40 @@ static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
 	/* error */
  out:
 	while (--level > minlevel)
-		nilfs_btree_abort_update_v(btree, path, level);
+		nilfs_btree_abort_update_v(btree, path, level, dat);
 	if (!buffer_nilfs_volatile(path[level].bp_bh))
-		nilfs_btree_abort_update_v(btree, path, level);
+		nilfs_btree_abort_update_v(btree, path, level, dat);
 	return ret;
 }
 
 static void nilfs_btree_commit_propagate_v(struct nilfs_btree *btree,
 					   struct nilfs_btree_path *path,
-					   int minlevel,
-					   int maxlevel,
-					   struct buffer_head *bh)
+					   int minlevel, int maxlevel,
+					   struct buffer_head *bh,
+					   struct inode *dat)
 {
 	int level;
 
 	if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
-		nilfs_btree_commit_update_v(btree, path, minlevel);
+		nilfs_btree_commit_update_v(btree, path, minlevel, dat);
 
 	for (level = minlevel + 1; level <= maxlevel; level++)
-		nilfs_btree_commit_update_v(btree, path, level);
+		nilfs_btree_commit_update_v(btree, path, level, dat);
 }
 
 static int nilfs_btree_propagate_v(struct nilfs_btree *btree,
 				   struct nilfs_btree_path *path,
-				   int level,
-				   struct buffer_head *bh)
+				   int level, struct buffer_head *bh)
 {
 	int maxlevel, ret;
 	struct nilfs_btree_node *parent;
+	struct inode *dat = nilfs_bmap_get_dat(&btree->bt_bmap);
 	__u64 ptr;
 
 	get_bh(bh);
 	path[level].bp_bh = bh;
-	ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel);
+	ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
+					      dat);
 	if (ret < 0)
 		goto out;
 
@@ -1961,12 +1927,12 @@ static int nilfs_btree_propagate_v(struct nilfs_btree *btree,
 		parent = nilfs_btree_get_node(btree, path, level + 1);
 		ptr = nilfs_btree_node_get_ptr(btree, parent,
 					       path[level + 1].bp_index);
-		ret = nilfs_bmap_mark_dirty(&btree->bt_bmap, ptr);
+		ret = nilfs_dat_mark_dirty(dat, ptr);
 		if (ret < 0)
 			goto out;
 	}
 
-	nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh);
+	nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
 
  out:
 	brelse(path[level].bp_bh);
@@ -1986,15 +1952,15 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
 	WARN_ON(!buffer_dirty(bh));
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	if (buffer_nilfs_node(bh)) {
 		node = (struct nilfs_btree_node *)bh->b_data;
-		key = nilfs_btree_node_get_key(btree, node, 0);
-		level = nilfs_btree_node_get_level(btree, node);
+		key = nilfs_btree_node_get_key(node, 0);
+		level = nilfs_btree_node_get_level(node);
 	} else {
 		key = nilfs_bmap_data_get_key(bmap, bh);
 		level = NILFS_BTREE_LEVEL_DATA;
@@ -2013,8 +1979,8 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
 		nilfs_btree_propagate_p(btree, path, level, bh);
 
  out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 
 	return ret;
 }
@@ -2022,7 +1988,7 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
 static int nilfs_btree_propagate_gc(const struct nilfs_bmap *bmap,
 				    struct buffer_head *bh)
 {
-	return nilfs_bmap_mark_dirty(bmap, bh->b_blocknr);
+	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), bh->b_blocknr);
 }
 
 static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree,
@@ -2037,12 +2003,12 @@ static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree,
 
 	get_bh(bh);
 	node = (struct nilfs_btree_node *)bh->b_data;
-	key = nilfs_btree_node_get_key(btree, node, 0);
-	level = nilfs_btree_node_get_level(btree, node);
+	key = nilfs_btree_node_get_key(node, 0);
+	level = nilfs_btree_node_get_level(node);
 	list_for_each(head, &lists[level]) {
 		cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
 		cnode = (struct nilfs_btree_node *)cbh->b_data;
-		ckey = nilfs_btree_node_get_key(btree, cnode, 0);
+		ckey = nilfs_btree_node_get_key(cnode, 0);
 		if (key < ckey)
 			break;
 	}
@@ -2120,8 +2086,7 @@ static int nilfs_btree_assign_p(struct nilfs_btree *btree,
 	nilfs_btree_node_set_ptr(btree, parent,
 				 path[level + 1].bp_index, blocknr);
 
-	key = nilfs_btree_node_get_key(btree, parent,
-				       path[level + 1].bp_index);
+	key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
 	/* on-disk format */
 	binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 	binfo->bi_dat.bi_level = level;
@@ -2137,6 +2102,7 @@ static int nilfs_btree_assign_v(struct nilfs_btree *btree,
 				union nilfs_binfo *binfo)
 {
 	struct nilfs_btree_node *parent;
+	struct inode *dat = nilfs_bmap_get_dat(&btree->bt_bmap);
 	__u64 key;
 	__u64 ptr;
 	union nilfs_bmap_ptr_req req;
@@ -2146,12 +2112,12 @@ static int nilfs_btree_assign_v(struct nilfs_btree *btree,
 	ptr = nilfs_btree_node_get_ptr(btree, parent,
 				       path[level + 1].bp_index);
 	req.bpr_ptr = ptr;
-	ret = nilfs_bmap_start_v(&btree->bt_bmap, &req, blocknr);
-	if (unlikely(ret < 0))
+	ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
+	if (ret < 0)
 		return ret;
+	nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
 
-	key = nilfs_btree_node_get_key(btree, parent,
-				       path[level + 1].bp_index);
+	key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
 	/* on-disk format */
 	binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 	binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
@@ -2171,15 +2137,15 @@ static int nilfs_btree_assign(struct nilfs_bmap *bmap,
 	int level, ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	if (buffer_nilfs_node(*bh)) {
 		node = (struct nilfs_btree_node *)(*bh)->b_data;
-		key = nilfs_btree_node_get_key(btree, node, 0);
-		level = nilfs_btree_node_get_level(btree, node);
+		key = nilfs_btree_node_get_key(node, 0);
+		level = nilfs_btree_node_get_level(node);
 	} else {
 		key = nilfs_bmap_data_get_key(bmap, *bh);
 		level = NILFS_BTREE_LEVEL_DATA;
@@ -2196,8 +2162,8 @@ static int nilfs_btree_assign(struct nilfs_bmap *bmap,
 		nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
 
  out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 
 	return ret;
 }
@@ -2207,19 +2173,18 @@ static int nilfs_btree_assign_gc(struct nilfs_bmap *bmap,
 				 sector_t blocknr,
 				 union nilfs_binfo *binfo)
 {
-	struct nilfs_btree *btree;
 	struct nilfs_btree_node *node;
 	__u64 key;
 	int ret;
 
-	btree = (struct nilfs_btree *)bmap;
-	ret = nilfs_bmap_move_v(bmap, (*bh)->b_blocknr, blocknr);
+	ret = nilfs_dat_move(nilfs_bmap_get_dat(bmap), (*bh)->b_blocknr,
+			     blocknr);
 	if (ret < 0)
 		return ret;
 
 	if (buffer_nilfs_node(*bh)) {
 		node = (struct nilfs_btree_node *)(*bh)->b_data;
-		key = nilfs_btree_node_get_key(btree, node, 0);
+		key = nilfs_btree_node_get_key(node, 0);
 	} else
 		key = nilfs_bmap_data_get_key(bmap, *bh);
 
@@ -2239,10 +2204,10 @@ static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 	int ret;
 
 	btree = (struct nilfs_btree *)bmap;
-	path = nilfs_btree_alloc_path(btree);
+	path = nilfs_btree_alloc_path();
 	if (path == NULL)
 		return -ENOMEM;
-	nilfs_btree_init_path(btree, path);
+	nilfs_btree_init_path(path);
 
 	ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1);
 	if (ret < 0) {
@@ -2262,8 +2227,8 @@ static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 		nilfs_bmap_set_dirty(&btree->bt_bmap);
 
  out:
-	nilfs_btree_clear_path(btree, path);
-	nilfs_btree_free_path(btree, path);
+	nilfs_btree_release_path(path);
+	nilfs_btree_free_path(path);
 	return ret;
 }