3 files changed, 31 insertions, 2 deletions
diff --git a/pkg/btrfs/btrfsitem/item_chunk.go b/pkg/btrfs/btrfsitem/item_chunk.go
index a77ae33..efd9d31 100644
--- a/pkg/btrfs/btrfsitem/item_chunk.go
+++ b/pkg/btrfs/btrfsitem/item_chunk.go
@@ -32,12 +32,28 @@ type ChunkHeader struct {
 }
 
 type ChunkStripe struct {
-	DeviceID      internal.ObjID        `bin:"off=0x0,  siz=0x8"`
+	DeviceID      btrfsvol.DeviceID     `bin:"off=0x0,  siz=0x8"`
 	Offset        btrfsvol.PhysicalAddr `bin:"off=0x8,  siz=0x8"`
 	DeviceUUID    util.UUID             `bin:"off=0x10, siz=0x10"`
 	binstruct.End `bin:"off=0x20"`
 }
 
+func (chunk Chunk) Mappings(key internal.Key) []btrfsvol.Mapping {
+	ret := make([]btrfsvol.Mapping, 0, len(chunk.Stripes))
+	for _, stripe := range chunk.Stripes {
+		ret = append(ret, btrfsvol.Mapping{
+			LAddr: btrfsvol.LogicalAddr(key.Offset),
+			PAddr: btrfsvol.QualifiedPhysicalAddr{
+				Dev:  stripe.DeviceID,
+				Addr: stripe.Offset,
+			},
+			Size:  chunk.Head.Size,
+			Flags: &chunk.Head.Type,
+		})
+	}
+	return ret
+}
+
 func (chunk *Chunk) UnmarshalBinary(dat []byte) (int, error) {
 	n, err := binstruct.Unmarshal(dat, &chunk.Head)
 	if err != nil {
diff --git a/pkg/btrfs/btrfsitem/item_dev.go b/pkg/btrfs/btrfsitem/item_dev.go
index 848f338..1c0fea0 100644
--- a/pkg/btrfs/btrfsitem/item_dev.go
+++ b/pkg/btrfs/btrfsitem/item_dev.go
@@ -2,12 +2,13 @@ package btrfsitem
 
 import (
 	"lukeshu.com/btrfs-tools/pkg/binstruct"
+	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsvol"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/internal"
 	"lukeshu.com/btrfs-tools/pkg/util"
 )
 
 type Dev struct { // DEV_ITEM=216
-	DeviceID internal.ObjID `bin:"off=0x0,    siz=0x8"`
+	DevID btrfsvol.DeviceID `bin:"off=0x0,    siz=0x8"`
 
 	NumBytes     uint64 `bin:"off=0x8,    siz=0x8"`
 	NumBytesUsed uint64 `bin:"off=0x10,   siz=0x8"`
diff --git a/pkg/btrfs/btrfsitem/item_devextent.go b/pkg/btrfs/btrfsitem/item_devextent.go
index 03d696a..c7707bd 100644
--- a/pkg/btrfs/btrfsitem/item_devextent.go
+++ b/pkg/btrfs/btrfsitem/item_devextent.go
@@ -17,3 +17,15 @@ type DevExtent struct { // DEV_EXTENT=204
 	ChunkTreeUUID util.UUID            `bin:"off=32, siz=16"`
 	binstruct.End `bin:"off=48"`
 }
+
+func (devext DevExtent) Mapping(key internal.Key) btrfsvol.Mapping {
+	return btrfsvol.Mapping{
+		LAddr: devext.ChunkOffset,
+		PAddr: btrfsvol.QualifiedPhysicalAddr{
+			Dev:  btrfsvol.DeviceID(key.ObjectID),
+			Addr: btrfsvol.PhysicalAddr(key.Offset),
+		},
+		Size:  devext.Length,
+		Flags: nil,
+	}
+}