diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index de67d2a12515..51824c764294 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -31,21 +31,26 @@
 #include "dat.h"
 #include "alloc.h"
 
+static struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
+{
+	return nilfs_dat_inode(NILFS_I_NILFS(bmap->b_inode));
+}
+
 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
 			       __u64 *ptrp)
 {
-	__u64 ptr;
+	sector_t blocknr;
 	int ret;
 
 	down_read(&bmap->b_sem);
 	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
 	if (ret < 0)
 		goto out;
-	if (bmap->b_pops->bpop_translate != NULL) {
-		ret = bmap->b_pops->bpop_translate(bmap, *ptrp, &ptr);
-		if (ret < 0)
-			goto out;
-		*ptrp = ptr;
+	if (NILFS_BMAP_USE_VBN(bmap)) {
+		ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
+					  &blocknr);
+		if (!ret)
+			*ptrp = blocknr;
 	}
 
  out:
@@ -442,11 +447,6 @@ __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 		return NILFS_BMAP_INVALID_PTR;
 }
 
-static struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
-{
-	return nilfs_dat_inode(NILFS_I_NILFS(bmap->b_inode));
-}
-
 #define NILFS_BMAP_GROUP_DIV	8
 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 {
@@ -459,20 +459,20 @@ __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 		(entries_per_group / NILFS_BMAP_GROUP_DIV);
 }
 
-static int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
+int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *bmap,
+				 union nilfs_bmap_ptr_req *req)
 {
 	return nilfs_dat_prepare_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 }
 
-static void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
+void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *bmap,
+				 union nilfs_bmap_ptr_req *req)
 {
 	nilfs_dat_commit_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 }
 
-static void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *bmap,
-				     union nilfs_bmap_ptr_req *req)
+void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *bmap,
+			      union nilfs_bmap_ptr_req *req)
 {
 	nilfs_dat_abort_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 }
@@ -489,26 +489,21 @@ int nilfs_bmap_start_v(struct nilfs_bmap *bmap, union nilfs_bmap_ptr_req *req,
 	return ret;
 }
 
-static int nilfs_bmap_prepare_end_v(struct nilfs_bmap *bmap,
-				    union nilfs_bmap_ptr_req *req)
+int nilfs_bmap_prepare_end_v(struct nilfs_bmap *bmap,
+			     union nilfs_bmap_ptr_req *req)
 {
 	return nilfs_dat_prepare_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 }
 
-static void nilfs_bmap_commit_end_v(struct nilfs_bmap *bmap,
-				    union nilfs_bmap_ptr_req *req)
+void nilfs_bmap_commit_end_v(struct nilfs_bmap *bmap,
+			     union nilfs_bmap_ptr_req *req)
 {
-	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 0);
+	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req,
+			     bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 }
 
-static void nilfs_bmap_commit_end_vmdt(struct nilfs_bmap *bmap,
-				       union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 1);
-}
-
-static void nilfs_bmap_abort_end_v(struct nilfs_bmap *bmap,
-				   union nilfs_bmap_ptr_req *req)
+void nilfs_bmap_abort_end_v(struct nilfs_bmap *bmap,
+			    union nilfs_bmap_ptr_req *req)
 {
 	nilfs_dat_abort_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 }
@@ -524,116 +519,44 @@ int nilfs_bmap_mark_dirty(const struct nilfs_bmap *bmap, __u64 vblocknr)
 	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), vblocknr);
 }
 
-int nilfs_bmap_prepare_update(struct nilfs_bmap *bmap,
-			      union nilfs_bmap_ptr_req *oldreq,
-			      union nilfs_bmap_ptr_req *newreq)
+int nilfs_bmap_prepare_update_v(struct nilfs_bmap *bmap,
+				union nilfs_bmap_ptr_req *oldreq,
+				union nilfs_bmap_ptr_req *newreq)
 {
+	struct inode *dat = nilfs_bmap_get_dat(bmap);
 	int ret;
 
-	ret = bmap->b_pops->bpop_prepare_end_ptr(bmap, oldreq);
+	ret = nilfs_dat_prepare_end(dat, &oldreq->bpr_req);
 	if (ret < 0)
 		return ret;
-	ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, newreq);
+	ret = nilfs_dat_prepare_alloc(dat, &newreq->bpr_req);
 	if (ret < 0)
-		bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
+		nilfs_dat_abort_end(dat, &oldreq->bpr_req);
 
 	return ret;
 }
 
-void nilfs_bmap_commit_update(struct nilfs_bmap *bmap,
-			      union nilfs_bmap_ptr_req *oldreq,
-			      union nilfs_bmap_ptr_req *newreq)
+void nilfs_bmap_commit_update_v(struct nilfs_bmap *bmap,
+				union nilfs_bmap_ptr_req *oldreq,
+				union nilfs_bmap_ptr_req *newreq)
 {
-	bmap->b_pops->bpop_commit_end_ptr(bmap, oldreq);
-	bmap->b_pops->bpop_commit_alloc_ptr(bmap, newreq);
+	struct inode *dat = nilfs_bmap_get_dat(bmap);
+
+	nilfs_dat_commit_end(dat, &oldreq->bpr_req,
+			     bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
+	nilfs_dat_commit_alloc(dat, &newreq->bpr_req);
 }
 
-void nilfs_bmap_abort_update(struct nilfs_bmap *bmap,
-			     union nilfs_bmap_ptr_req *oldreq,
-			     union nilfs_bmap_ptr_req *newreq)
+void nilfs_bmap_abort_update_v(struct nilfs_bmap *bmap,
+			       union nilfs_bmap_ptr_req *oldreq,
+			       union nilfs_bmap_ptr_req *newreq)
 {
-	bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
-	bmap->b_pops->bpop_abort_alloc_ptr(bmap, newreq);
+	struct inode *dat = nilfs_bmap_get_dat(bmap);
+
+	nilfs_dat_abort_end(dat, &oldreq->bpr_req);
+	nilfs_dat_abort_alloc(dat, &newreq->bpr_req);
 }
 
-static int nilfs_bmap_translate_v(const struct nilfs_bmap *bmap, __u64 ptr,
-				  __u64 *ptrp)
-{
-	sector_t blocknr;
-	int ret;
-
-	ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), ptr, &blocknr);
-	if (ret < 0)
-		return ret;
-	if (ptrp != NULL)
-		*ptrp = blocknr;
-	return 0;
-}
-
-static int nilfs_bmap_prepare_alloc_p(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	/* ignore target ptr */
-	req->bpr_ptr = bmap->b_last_allocated_ptr++;
-	return 0;
-}
-
-static void nilfs_bmap_commit_alloc_p(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	/* do nothing */
-}
-
-static void nilfs_bmap_abort_alloc_p(struct nilfs_bmap *bmap,
-				     union nilfs_bmap_ptr_req *req)
-{
-	bmap->b_last_allocated_ptr--;
-}
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_v = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
-	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
-	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_v,
-	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
-
-	.bpop_translate		=	nilfs_bmap_translate_v,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_vmdt = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
-	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
-	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_vmdt,
-	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
-
-	.bpop_translate		=	nilfs_bmap_translate_v,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_p = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_p,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_p,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_p,
-	.bpop_prepare_end_ptr	=	NULL,
-	.bpop_commit_end_ptr	=	NULL,
-	.bpop_abort_end_ptr	=	NULL,
-
-	.bpop_translate		=	NULL,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_gc = {
-	.bpop_prepare_alloc_ptr	=	NULL,
-	.bpop_commit_alloc_ptr	=	NULL,
-	.bpop_abort_alloc_ptr	=	NULL,
-	.bpop_prepare_end_ptr	=	NULL,
-	.bpop_commit_end_ptr	=	NULL,
-	.bpop_abort_end_ptr	=	NULL,
-
-	.bpop_translate		=	NULL,
-};
-
 static struct lock_class_key nilfs_bmap_dat_lock_key;
 
 /**
@@ -660,20 +583,20 @@ int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 	switch (bmap->b_inode->i_ino) {
 	case NILFS_DAT_INO:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_p;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_P;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 		break;
 	case NILFS_CPFILE_INO:
 	case NILFS_SUFILE_INO:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_vmdt;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 		break;
 	default:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_v;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 		break;
 	}
@@ -705,7 +628,7 @@ void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 	memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 	init_rwsem(&bmap->b_sem);
 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
-	bmap->b_pops = &nilfs_bmap_ptr_ops_gc;
+	bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 	bmap->b_last_allocated_key = 0;
 	bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 	bmap->b_state = 0;
diff --git a/fs/nilfs2/bmap.h b/fs/nilfs2/bmap.h
index 28c77bb71bb7..47f5b74713c0 100644
--- a/fs/nilfs2/bmap.h
+++ b/fs/nilfs2/bmap.h
@@ -86,27 +86,6 @@ struct nilfs_bmap_operations {
 };
 
 
-/**
- * struct nilfs_bmap_ptr_operations - bmap ptr operation table
- */
-struct nilfs_bmap_ptr_operations {
-	int (*bpop_prepare_alloc_ptr)(struct nilfs_bmap *,
-				      union nilfs_bmap_ptr_req *);
-	void (*bpop_commit_alloc_ptr)(struct nilfs_bmap *,
-				      union nilfs_bmap_ptr_req *);
-	void (*bpop_abort_alloc_ptr)(struct nilfs_bmap *,
-				     union nilfs_bmap_ptr_req *);
-	int (*bpop_prepare_end_ptr)(struct nilfs_bmap *,
-				    union nilfs_bmap_ptr_req *);
-	void (*bpop_commit_end_ptr)(struct nilfs_bmap *,
-				    union nilfs_bmap_ptr_req *);
-	void (*bpop_abort_end_ptr)(struct nilfs_bmap *,
-				   union nilfs_bmap_ptr_req *);
-
-	int (*bpop_translate)(const struct nilfs_bmap *, __u64, __u64 *);
-};
-
-
 #define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
 #define NILFS_BMAP_KEY_BIT	(sizeof(unsigned long) * 8 /* CHAR_BIT */)
 #define NILFS_BMAP_NEW_PTR_INIT	\
@@ -124,9 +103,9 @@ static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
  * @b_sem: semaphore
  * @b_inode: owner of bmap
  * @b_ops: bmap operation table
- * @b_pops: bmap ptr operation table
  * @b_last_allocated_key: last allocated key for data block
  * @b_last_allocated_ptr: last allocated ptr for data block
+ * @b_ptr_type: pointer type
  * @b_state: state
  */
 struct nilfs_bmap {
@@ -137,12 +116,22 @@ struct nilfs_bmap {
 	struct rw_semaphore b_sem;
 	struct inode *b_inode;
 	const struct nilfs_bmap_operations *b_ops;
-	const struct nilfs_bmap_ptr_operations *b_pops;
 	__u64 b_last_allocated_key;
 	__u64 b_last_allocated_ptr;
+	int b_ptr_type;
 	int b_state;
 };
 
+/* pointer type */
+#define NILFS_BMAP_PTR_P	0	/* physical block number (i.e. LBN) */
+#define NILFS_BMAP_PTR_VS	1	/* virtual block number (single
+					   version) */
+#define NILFS_BMAP_PTR_VM	2	/* virtual block number (has multiple
+					   versions) */
+#define NILFS_BMAP_PTR_U	(-1)	/* never perform pointer operations */
+
+#define NILFS_BMAP_USE_VBN(bmap)	((bmap)->b_ptr_type > 0)
+
 /* state */
 #define NILFS_BMAP_DIRTY	0x00000001
 
@@ -171,6 +160,63 @@ void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 /*
  * Internal use only
  */
+int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *,
+			       union nilfs_bmap_ptr_req *);
+void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *,
+			       union nilfs_bmap_ptr_req *);
+void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *,
+			      union nilfs_bmap_ptr_req *);
+
+static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
+					       union nilfs_bmap_ptr_req *req)
+{
+	if (NILFS_BMAP_USE_VBN(bmap))
+		return nilfs_bmap_prepare_alloc_v(bmap, req);
+	/* ignore target ptr */
+	req->bpr_ptr = bmap->b_last_allocated_ptr++;
+	return 0;
+}
+
+static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
+					       union nilfs_bmap_ptr_req *req)
+{
+	if (NILFS_BMAP_USE_VBN(bmap))
+		nilfs_bmap_commit_alloc_v(bmap, req);
+}
+
+static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
+					      union nilfs_bmap_ptr_req *req)
+{
+	if (NILFS_BMAP_USE_VBN(bmap))
+		nilfs_bmap_abort_alloc_v(bmap, req);
+	else
+		bmap->b_last_allocated_ptr--;
+}
+
+int nilfs_bmap_prepare_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
+void nilfs_bmap_commit_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
+void nilfs_bmap_abort_end_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *);
+
+static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
+					     union nilfs_bmap_ptr_req *req)
+{
+	return NILFS_BMAP_USE_VBN(bmap) ?
+		nilfs_bmap_prepare_end_v(bmap, req) : 0;
+}
+
+static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
+					     union nilfs_bmap_ptr_req *req)
+{
+	if (NILFS_BMAP_USE_VBN(bmap))
+		nilfs_bmap_commit_end_v(bmap, req);
+}
+
+static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
+					    union nilfs_bmap_ptr_req *req)
+{
+	if (NILFS_BMAP_USE_VBN(bmap))
+		nilfs_bmap_abort_end_v(bmap, req);
+}
 
 int nilfs_bmap_start_v(struct nilfs_bmap *, union nilfs_bmap_ptr_req *,
 		       sector_t);
@@ -184,15 +230,15 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 
-int nilfs_bmap_prepare_update(struct nilfs_bmap *,
-			      union nilfs_bmap_ptr_req *,
-			      union nilfs_bmap_ptr_req *);
-void nilfs_bmap_commit_update(struct nilfs_bmap *,
-			      union nilfs_bmap_ptr_req *,
-			      union nilfs_bmap_ptr_req *);
-void nilfs_bmap_abort_update(struct nilfs_bmap *,
-			     union nilfs_bmap_ptr_req *,
-			     union nilfs_bmap_ptr_req *);
+int nilfs_bmap_prepare_update_v(struct nilfs_bmap *,
+				union nilfs_bmap_ptr_req *,
+				union nilfs_bmap_ptr_req *);
+void nilfs_bmap_commit_update_v(struct nilfs_bmap *,
+				union nilfs_bmap_ptr_req *,
+				union nilfs_bmap_ptr_req *);
+void nilfs_bmap_abort_update_v(struct nilfs_bmap *,
+			       union nilfs_bmap_ptr_req *,
+			       union nilfs_bmap_ptr_req *);
 
 void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index f5a0ec64e1aa..20e3fd0f4d4f 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -917,8 +917,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 		path[level].bp_newreq.bpr_ptr =
 			btree->bt_ops->btop_find_target(btree, path, key);
 
-	ret = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-		&btree->bt_bmap, &path[level].bp_newreq);
+	ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+					   &path[level].bp_newreq);
 	if (ret < 0)
 		goto err_out_data;
 
@@ -976,8 +976,8 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 		/* split */
 		path[level].bp_newreq.bpr_ptr =
 			path[level - 1].bp_newreq.bpr_ptr + 1;
-		ret = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-			&btree->bt_bmap, &path[level].bp_newreq);
+		ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+						   &path[level].bp_newreq);
 		if (ret < 0)
 			goto err_out_child_node;
 		ret = nilfs_btree_get_new_block(btree,
@@ -1008,8 +1008,8 @@ 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 = btree->bt_bmap.b_pops->bpop_prepare_alloc_ptr(
-		&btree->bt_bmap, &path[level].bp_newreq);
+	ret = nilfs_bmap_prepare_alloc_ptr(&btree->bt_bmap,
+					   &path[level].bp_newreq);
 	if (ret < 0)
 		goto err_out_child_node;
 	ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
@@ -1037,18 +1037,16 @@ static int nilfs_btree_prepare_insert(struct nilfs_btree *btree,
 
 	/* error */
  err_out_curr_node:
-	btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(&btree->bt_bmap,
-						    &path[level].bp_newreq);
+	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
  err_out_child_node:
 	for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
 		nilfs_btnode_delete(path[level].bp_sib_bh);
-		btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(
-			&btree->bt_bmap, &path[level].bp_newreq);
+		nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap,
+					   &path[level].bp_newreq);
 
 	}
 
-	btree->bt_bmap.b_pops->bpop_abort_alloc_ptr(&btree->bt_bmap,
-						       &path[level].bp_newreq);
+	nilfs_bmap_abort_alloc_ptr(&btree->bt_bmap, &path[level].bp_newreq);
  err_out_data:
 	*levelp = level;
 	stats->bs_nblocks = 0;
@@ -1067,8 +1065,8 @@ static void nilfs_btree_commit_insert(struct nilfs_btree *btree,
 		btree->bt_ops->btop_set_target(btree, key, ptr);
 
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
-		btree->bt_bmap.b_pops->bpop_commit_alloc_ptr(
-			&btree->bt_bmap, &path[level - 1].bp_newreq);
+		nilfs_bmap_commit_alloc_ptr(&btree->bt_bmap,
+					    &path[level - 1].bp_newreq);
 		path[level].bp_op(btree, path, level, &key, &ptr);
 	}
 
@@ -1312,12 +1310,10 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 		path[level].bp_oldreq.bpr_ptr =
 			nilfs_btree_node_get_ptr(btree, node,
 						 path[level].bp_index);
-		if (btree->bt_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
-			ret = btree->bt_bmap.b_pops->bpop_prepare_end_ptr(
-				&btree->bt_bmap, &path[level].bp_oldreq);
-			if (ret < 0)
-				goto err_out_child_node;
-		}
+		ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
+						 &path[level].bp_oldreq);
+		if (ret < 0)
+			goto err_out_child_node;
 
 		if (nilfs_btree_node_get_nchildren(btree, node) >
 		    nilfs_btree_node_nchildren_min(btree, node)) {
@@ -1391,12 +1387,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 	node = nilfs_btree_get_root(btree);
 	path[level].bp_oldreq.bpr_ptr =
 		nilfs_btree_node_get_ptr(btree, node, path[level].bp_index);
-	if (btree->bt_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
-		ret = btree->bt_bmap.b_pops->bpop_prepare_end_ptr(
-			&btree->bt_bmap, &path[level].bp_oldreq);
-		if (ret < 0)
-			goto err_out_child_node;
-	}
+
+	ret = nilfs_bmap_prepare_end_ptr(&btree->bt_bmap,
+					 &path[level].bp_oldreq);
+	if (ret < 0)
+		goto err_out_child_node;
+
 	/* child of the root node is deleted */
 	path[level].bp_op = nilfs_btree_do_delete;
 	stats->bs_nblocks++;
@@ -1408,15 +1404,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
 
 	/* error */
  err_out_curr_node:
-	if (btree->bt_bmap.b_pops->bpop_abort_end_ptr != NULL)
-		btree->bt_bmap.b_pops->bpop_abort_end_ptr(
-			&btree->bt_bmap, &path[level].bp_oldreq);
+	nilfs_bmap_abort_end_ptr(&btree->bt_bmap, &path[level].bp_oldreq);
  err_out_child_node:
 	for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
 		brelse(path[level].bp_sib_bh);
-		if (btree->bt_bmap.b_pops->bpop_abort_end_ptr != NULL)
-			btree->bt_bmap.b_pops->bpop_abort_end_ptr(
-				&btree->bt_bmap, &path[level].bp_oldreq);
+		nilfs_bmap_abort_end_ptr(&btree->bt_bmap,
+					 &path[level].bp_oldreq);
 	}
 	*levelp = level;
 	stats->bs_nblocks = 0;
@@ -1430,9 +1423,8 @@ static void nilfs_btree_commit_delete(struct nilfs_btree *btree,
 	int level;
 
 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
-		if (btree->bt_bmap.b_pops->bpop_commit_end_ptr != NULL)
-			btree->bt_bmap.b_pops->bpop_commit_end_ptr(
-				&btree->bt_bmap, &path[level].bp_oldreq);
+		nilfs_bmap_commit_end_ptr(&btree->bt_bmap,
+					  &path[level].bp_oldreq);
 		path[level].bp_op(btree, path, level, NULL, NULL);
 	}
 
@@ -1597,7 +1589,7 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 	if (btree->bt_ops->btop_find_target != NULL)
 		dreq->bpr_ptr
 			= btree->bt_ops->btop_find_target(btree, NULL, key);
-	ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, dreq);
+	ret = nilfs_bmap_prepare_alloc_ptr(bmap, dreq);
 	if (ret < 0)
 		return ret;
 
@@ -1605,7 +1597,7 @@ 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 = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, nreq);
+		ret = nilfs_bmap_prepare_alloc_ptr(bmap, nreq);
 		if (ret < 0)
 			goto err_out_dreq;
 
@@ -1622,9 +1614,9 @@ nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *bmap, __u64 key,
 
 	/* error */
  err_out_nreq:
-	bmap->b_pops->bpop_abort_alloc_ptr(bmap, nreq);
+	nilfs_bmap_abort_alloc_ptr(bmap, nreq);
  err_out_dreq:
-	bmap->b_pops->bpop_abort_alloc_ptr(bmap, dreq);
+	nilfs_bmap_abort_alloc_ptr(bmap, dreq);
 	stats->bs_nblocks = 0;
 	return ret;
 
@@ -1654,8 +1646,8 @@ nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *bmap,
 	btree = (struct nilfs_btree *)bmap;
 	nilfs_btree_init(bmap);
 	if (nreq != NULL) {
-		bmap->b_pops->bpop_commit_alloc_ptr(bmap, dreq);
-		bmap->b_pops->bpop_commit_alloc_ptr(bmap, nreq);
+		nilfs_bmap_commit_alloc_ptr(bmap, dreq);
+		nilfs_bmap_commit_alloc_ptr(bmap, nreq);
 
 		/* create child node at level 1 */
 		lock_buffer(bh);
@@ -1677,7 +1669,7 @@ 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 {
-		bmap->b_pops->bpop_commit_alloc_ptr(bmap, dreq);
+		nilfs_bmap_commit_alloc_ptr(bmap, dreq);
 
 		/* create root node at level 1 */
 		node = nilfs_btree_get_root(btree);
@@ -1758,9 +1750,9 @@ 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(&btree->bt_bmap,
-					&path[level].bp_oldreq,
-					&path[level].bp_newreq);
+	ret = nilfs_bmap_prepare_update_v(&btree->bt_bmap,
+					  &path[level].bp_oldreq,
+					  &path[level].bp_newreq);
 	if (ret < 0)
 		return ret;
 
@@ -1772,9 +1764,9 @@ 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(&btree->bt_bmap,
-						&path[level].bp_oldreq,
-						&path[level].bp_newreq);
+			nilfs_bmap_abort_update_v(&btree->bt_bmap,
+						  &path[level].bp_oldreq,
+						  &path[level].bp_newreq);
 			return ret;
 		}
 	}
@@ -1788,9 +1780,9 @@ static void nilfs_btree_commit_update_v(struct nilfs_btree *btree,
 {
 	struct nilfs_btree_node *parent;
 
-	nilfs_bmap_commit_update(&btree->bt_bmap,
-				 &path[level].bp_oldreq,
-				 &path[level].bp_newreq);
+	nilfs_bmap_commit_update_v(&btree->bt_bmap,
+				   &path[level].bp_oldreq,
+				   &path[level].bp_newreq);
 
 	if (buffer_nilfs_node(path[level].bp_bh)) {
 		nilfs_btnode_commit_change_key(
@@ -1809,9 +1801,9 @@ static void nilfs_btree_abort_update_v(struct nilfs_btree *btree,
 				       struct nilfs_btree_path *path,
 				       int level)
 {
-	nilfs_bmap_abort_update(&btree->bt_bmap,
-				&path[level].bp_oldreq,
-				&path[level].bp_newreq);
+	nilfs_bmap_abort_update_v(&btree->bt_bmap,
+				  &path[level].bp_oldreq,
+				  &path[level].bp_newreq);
 	if (buffer_nilfs_node(path[level].bp_bh))
 		nilfs_btnode_abort_change_key(
 			&NILFS_BMAP_I(&btree->bt_bmap)->i_btnode_cache,
diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
index 8e8095c2e1bb..2a546c8f784e 100644
--- a/fs/nilfs2/direct.c
+++ b/fs/nilfs2/direct.c
@@ -92,8 +92,7 @@ static int nilfs_direct_prepare_insert(struct nilfs_direct *direct,
 
 	if (direct->d_ops->dop_find_target != NULL)
 		req->bpr_ptr = direct->d_ops->dop_find_target(direct, key);
-	ret = direct->d_bmap.b_pops->bpop_prepare_alloc_ptr(&direct->d_bmap,
-							       req);
+	ret = nilfs_bmap_prepare_alloc_ptr(&direct->d_bmap, req);
 	if (ret < 0)
 		return ret;
 
@@ -111,7 +110,7 @@ static void nilfs_direct_commit_insert(struct nilfs_direct *direct,
 	bh = (struct buffer_head *)((unsigned long)ptr);
 	set_buffer_nilfs_volatile(bh);
 
-	direct->d_bmap.b_pops->bpop_commit_alloc_ptr(&direct->d_bmap, req);
+	nilfs_bmap_commit_alloc_ptr(&direct->d_bmap, req);
 	nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
 
 	if (!nilfs_bmap_dirty(&direct->d_bmap))
@@ -150,25 +149,18 @@ static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
 {
 	int ret;
 
-	if (direct->d_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
-		req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
-		ret = direct->d_bmap.b_pops->bpop_prepare_end_ptr(
-			&direct->d_bmap, req);
-		if (ret < 0)
-			return ret;
-	}
-
-	stats->bs_nblocks = 1;
-	return 0;
+	req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
+	ret = nilfs_bmap_prepare_end_ptr(&direct->d_bmap, req);
+	if (!ret)
+		stats->bs_nblocks = 1;
+	return ret;
 }
 
 static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
 				       union nilfs_bmap_ptr_req *req,
 				       __u64 key)
 {
-	if (direct->d_bmap.b_pops->bpop_commit_end_ptr != NULL)
-		direct->d_bmap.b_pops->bpop_commit_end_ptr(
-			&direct->d_bmap, req);
+	nilfs_bmap_commit_end_ptr(&direct->d_bmap, req);
 	nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 }
 
@@ -289,11 +281,11 @@ static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
 	if (!buffer_nilfs_volatile(bh)) {
 		oldreq.bpr_ptr = ptr;
 		newreq.bpr_ptr = ptr;
-		ret = nilfs_bmap_prepare_update(&direct->d_bmap, &oldreq,
-						&newreq);
+		ret = nilfs_bmap_prepare_update_v(&direct->d_bmap, &oldreq,
+						  &newreq);
 		if (ret < 0)
 			return ret;
-		nilfs_bmap_commit_update(&direct->d_bmap, &oldreq, &newreq);
+		nilfs_bmap_commit_update_v(&direct->d_bmap, &oldreq, &newreq);
 		set_buffer_nilfs_volatile(bh);
 		nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
 	} else