subvolumes

4 files changed, 44 insertions, 0 deletions

diff --git a/pkg/btrfs/btrfsitem/item_rootref.go b/pkg/btrfs/btrfsitem/item_rootref.go
new file mode 100644
index 0000000..567e9c7
--- /dev/null
+++ b/pkg/btrfs/btrfsitem/item_rootref.go
@@ -0,0 +1,34 @@
+package btrfsitem
+
+import (
+	"lukeshu.com/btrfs-tools/pkg/binstruct"
+	"lukeshu.com/btrfs-tools/pkg/btrfs/internal"
+)
+
+type RootRef struct { // ROOT_REF=156 ROOT_BACKREF=144
+	DirID         internal.ObjID `bin:"off=0x00, siz=0x8"`
+	Sequence      int64          `bin:"off=0x08, siz=0x8"`
+	NameLen       uint16         `bin:"off=0x10, siz=0x2"` // [ignored-when-writing]
+	binstruct.End `bin:"off=0x12"`
+	Name          []byte `bin:"-"`
+}
+
+func (o *RootRef) UnmarshalBinary(dat []byte) (int, error) {
+	n, err := binstruct.UnmarshalWithoutInterface(dat, o)
+	if err != nil {
+		return n, err
+	}
+	o.Name = dat[n : n+int(o.NameLen)]
+	n += int(o.NameLen)
+	return n, nil
+}
+
+func (o RootRef) MarshalBinary() ([]byte, error) {
+	o.NameLen = uint16(len(o.Name))
+	dat, err := binstruct.MarshalWithoutInterface(o)
+	if err != nil {
+		return dat, err
+	}
+	dat = append(dat, o.Name...)
+	return dat, nil
+}
diff --git a/pkg/btrfs/btrfsitem/item_uuid.go b/pkg/btrfs/btrfsitem/item_uuid.go
index d66e102..6b47547 100644
--- a/pkg/btrfs/btrfsitem/item_uuid.go
+++ b/pkg/btrfs/btrfsitem/item_uuid.go
@@ -7,6 +7,9 @@ import (
 
 // The Key for this item is a UUID, and the item is a list of
 // subvolume IDs (ObjectIDs) that that UUID maps to.
+//
+// key.objectid = first half of UUID
+// key.offset = second half of UUID
 type UUIDMap []internal.ObjID // UUID_SUBVOL=251 UUID_RECEIVED_SUBVOL=252
 
 func (o *UUIDMap) UnmarshalBinary(dat []byte) (int, error) {
diff --git a/pkg/btrfs/btrfsitem/items.txt b/pkg/btrfs/btrfsitem/items.txt
index a5f247f..2820788 100644
--- a/pkg/btrfs/btrfsitem/items.txt
+++ b/pkg/btrfs/btrfsitem/items.txt
@@ -17,7 +17,9 @@ METADATA_ITEM=169 Metadata
 ORPHAN_ITEM=48 Empty
 PERSISTENT_ITEM=249 DevStats
 QGROUP_RELATION=246 Empty
+ROOT_BACKREF=144 RootRef
 ROOT_ITEM=132 Root
+ROOT_REF=156 RootRef
 SHARED_BLOCK_REF=182 Empty
 SHARED_DATA_REF=184 SharedDataRef
 TREE_BLOCK_REF=176 Empty
diff --git a/pkg/btrfs/btrfsitem/items_gen.go b/pkg/btrfs/btrfsitem/items_gen.go
index 92e2523..030202b 100644
--- a/pkg/btrfs/btrfsitem/items_gen.go
+++ b/pkg/btrfs/btrfsitem/items_gen.go
@@ -28,7 +28,9 @@ const (
 	ORPHAN_ITEM_KEY          = internal.ORPHAN_ITEM_KEY
 	PERSISTENT_ITEM_KEY      = internal.PERSISTENT_ITEM_KEY
 	QGROUP_RELATION_KEY      = internal.QGROUP_RELATION_KEY
+	ROOT_BACKREF_KEY         = internal.ROOT_BACKREF_KEY
 	ROOT_ITEM_KEY            = internal.ROOT_ITEM_KEY
+	ROOT_REF_KEY             = internal.ROOT_REF_KEY
 	SHARED_BLOCK_REF_KEY     = internal.SHARED_BLOCK_REF_KEY
 	SHARED_DATA_REF_KEY      = internal.SHARED_DATA_REF_KEY
 	TREE_BLOCK_REF_KEY       = internal.TREE_BLOCK_REF_KEY
@@ -58,7 +60,9 @@ var keytype2gotype = map[Type]reflect.Type{
 	ORPHAN_ITEM_KEY:          reflect.TypeOf(Empty{}),
 	PERSISTENT_ITEM_KEY:      reflect.TypeOf(DevStats{}),
 	QGROUP_RELATION_KEY:      reflect.TypeOf(Empty{}),
+	ROOT_BACKREF_KEY:         reflect.TypeOf(RootRef{}),
 	ROOT_ITEM_KEY:            reflect.TypeOf(Root{}),
+	ROOT_REF_KEY:             reflect.TypeOf(RootRef{}),
 	SHARED_BLOCK_REF_KEY:     reflect.TypeOf(Empty{}),
 	SHARED_DATA_REF_KEY:      reflect.TypeOf(SharedDataRef{}),
 	TREE_BLOCK_REF_KEY:       reflect.TypeOf(Empty{}),
@@ -88,5 +92,6 @@ func (Inode) isItem()           {}
 func (InodeRefList) isItem()    {}
 func (Metadata) isItem()        {}
 func (Root) isItem()            {}
+func (RootRef) isItem()         {}
 func (SharedDataRef) isItem()   {}
 func (UUIDMap) isItem()         {}