diff --git a/build/version.go b/build/version.go
index a5980a922..095ce8d0c 100644
--- a/build/version.go
+++ b/build/version.go
@@ -3,7 +3,7 @@ package build
 var CurrentCommit string
 
 // Version is the local build version, set by build system
-const Version = "0.1.1"
+const Version = "0.1.2"
 
 var UserVersion = Version + CurrentCommit
 
@@ -16,7 +16,7 @@ var UserVersion = Version + CurrentCommit
 //                   R R  H
 //                   |\vv/|
 //                   vv  vv
-const APIVersion = 0x000101
+const APIVersion = 0x000102
 
 const (
 	MajorMask = 0xff0000
diff --git a/cmd/lotus-seal-worker/transfer.go b/cmd/lotus-seal-worker/transfer.go
index e091edadf..af4681a1f 100644
--- a/cmd/lotus-seal-worker/transfer.go
+++ b/cmd/lotus-seal-worker/transfer.go
@@ -132,7 +132,7 @@ func (w *worker) fetchSector(sectorID uint64, typ sectorbuilder.WorkerTaskType)
 	var err error
 	switch typ {
 	case sectorbuilder.WorkerPreCommit:
-		err = w.fetch("staged", sectorID)
+		err = w.fetch("staging", sectorID)
 	case sectorbuilder.WorkerCommit:
 		err = w.fetch("sealed", sectorID)
 		if err != nil {
diff --git a/lib/sectorbuilder/files.go b/lib/sectorbuilder/files.go
index 0e2cee0d2..88dbec988 100644
--- a/lib/sectorbuilder/files.go
+++ b/lib/sectorbuilder/files.go
@@ -17,11 +17,11 @@ func (sb *SectorBuilder) SectorName(sectorID uint64) string {
 }
 
 func (sb *SectorBuilder) StagedSectorPath(sectorID uint64) string {
-	return filepath.Join(sb.filesystem.staging(), sb.SectorName(sectorID))
+	return filepath.Join(sb.filesystem.pathFor(dataStaging), sb.SectorName(sectorID))
 }
 
 func (sb *SectorBuilder) unsealedSectorPath(sectorID uint64) string {
-	return filepath.Join(sb.filesystem.unsealed(), sb.SectorName(sectorID))
+	return filepath.Join(sb.filesystem.pathFor(dataUnsealed), sb.SectorName(sectorID))
 }
 
 func (sb *SectorBuilder) stagedSectorFile(sectorID uint64) (*os.File, error) {
@@ -29,13 +29,13 @@ func (sb *SectorBuilder) stagedSectorFile(sectorID uint64) (*os.File, error) {
 }
 
 func (sb *SectorBuilder) SealedSectorPath(sectorID uint64) (string, error) {
-	path := filepath.Join(sb.filesystem.sealed(), sb.SectorName(sectorID))
+	path := filepath.Join(sb.filesystem.pathFor(dataSealed), sb.SectorName(sectorID))
 
 	return path, nil
 }
 
 func (sb *SectorBuilder) sectorCacheDir(sectorID uint64) (string, error) {
-	dir := filepath.Join(sb.filesystem.cache(), sb.SectorName(sectorID))
+	dir := filepath.Join(sb.filesystem.pathFor(dataCache), sb.SectorName(sectorID))
 
 	err := os.Mkdir(dir, 0755)
 	if os.IsExist(err) {
@@ -46,16 +46,12 @@ func (sb *SectorBuilder) sectorCacheDir(sectorID uint64) (string, error) {
 }
 
 func (sb *SectorBuilder) GetPath(typ string, sectorName string) (string, error) {
-	switch typ {
-	case "staged":
-		return filepath.Join(sb.filesystem.staging(), sectorName), nil
-	case "sealed":
-		return filepath.Join(sb.filesystem.sealed(), sectorName), nil
-	case "cache":
-		return filepath.Join(sb.filesystem.cache(), sectorName), nil
-	default:
-		return "", xerrors.Errorf("unknown sector type for write: %s", typ)
+	_, found := overheadMul[dataType(typ)]
+	if !found {
+		return "", xerrors.Errorf("unknown sector type: %s", typ)
 	}
+
+	return sb.filesystem.pathFor(dataType(typ)), nil
 }
 
 func (sb *SectorBuilder) TrimCache(sectorID uint64) error {
diff --git a/lib/sectorbuilder/fs.go b/lib/sectorbuilder/fs.go
index adc2a621f..ac8de3a4d 100644
--- a/lib/sectorbuilder/fs.go
+++ b/lib/sectorbuilder/fs.go
@@ -9,18 +9,16 @@ import (
 	"syscall"
 )
 
-type dataType int
+type dataType string
 
 const (
-	dataCache dataType = iota
-	dataStaging
-	dataSealed
-	dataUnsealed
-
-	nDataTypes
+	dataCache    dataType = "cache"
+	dataStaging  dataType = "staging"
+	dataSealed   dataType = "sealed"
+	dataUnsealed dataType = "unsealed"
 )
 
-var overheadMul = []uint64{ // * sectorSize
+var overheadMul = map[dataType]uint64{ // * sectorSize
 	dataCache:    11, // TODO: check if true for 32G sectors
 	dataStaging:  1,
 	dataSealed:   1,
@@ -32,19 +30,24 @@ type fs struct {
 
 	// in progress actions
 
-	reserved [nDataTypes]uint64
+	reserved map[dataType]uint64
 
 	lk sync.Mutex
 }
 
 func openFs(dir string) *fs {
 	return &fs{
-		path: dir,
+		path:     dir,
+		reserved: map[dataType]uint64{},
 	}
 }
 
 func (f *fs) init() error {
-	for _, dir := range []string{f.path, f.cache(), f.staging(), f.sealed(), f.unsealed()} {
+	for _, dir := range []string{f.path,
+		f.pathFor(dataCache),
+		f.pathFor(dataStaging),
+		f.pathFor(dataSealed),
+		f.pathFor(dataUnsealed)} {
 		if err := os.Mkdir(dir, 0755); err != nil {
 			if os.IsExist(err) {
 				continue
@@ -56,20 +59,13 @@ func (f *fs) init() error {
 	return nil
 }
 
-func (f *fs) cache() string {
-	return filepath.Join(f.path, "cache")
-}
+func (f *fs) pathFor(typ dataType) string {
+	_, found := overheadMul[typ]
+	if !found {
+		panic("unknown data path requested")
+	}
 
-func (f *fs) staging() string {
-	return filepath.Join(f.path, "staging")
-}
-
-func (f *fs) sealed() string {
-	return filepath.Join(f.path, "sealed")
-}
-
-func (f *fs) unsealed() string {
-	return filepath.Join(f.path, "unsealed")
+	return filepath.Join(f.path, string(typ))
 }
 
 func (f *fs) reservedBytes() int64 {
@@ -86,7 +82,7 @@ func (f *fs) reserve(typ dataType, size uint64) error {
 
 	var fsstat syscall.Statfs_t
 
-	if err := syscall.Statfs(f.path, &fsstat); err != nil {
+	if err := syscall.Statfs(f.pathFor(typ), &fsstat); err != nil {
 		return err
 	}
 
diff --git a/lib/sectorbuilder/sectorbuilder.go b/lib/sectorbuilder/sectorbuilder.go
index 013a5eda6..59f8bd176 100644
--- a/lib/sectorbuilder/sectorbuilder.go
+++ b/lib/sectorbuilder/sectorbuilder.go
@@ -699,15 +699,15 @@ func fallbackPostChallengeCount(sectors uint64) uint64 {
 }
 
 func (sb *SectorBuilder) ImportFrom(osb *SectorBuilder, symlink bool) error {
-	if err := migrate(osb.filesystem.cache(), sb.filesystem.cache(), symlink); err != nil {
+	if err := migrate(osb.filesystem.pathFor(dataCache), sb.filesystem.pathFor(dataCache), symlink); err != nil {
 		return err
 	}
 
-	if err := migrate(osb.filesystem.sealed(), sb.filesystem.sealed(), symlink); err != nil {
+	if err := migrate(osb.filesystem.pathFor(dataStaging), sb.filesystem.pathFor(dataStaging), symlink); err != nil {
 		return err
 	}
 
-	if err := migrate(osb.filesystem.staging(), sb.filesystem.staging(), symlink); err != nil {
+	if err := migrate(osb.filesystem.pathFor(dataSealed), sb.filesystem.pathFor(dataSealed), symlink); err != nil {
 		return err
 	}