subvolumes

7 files changed, 90 insertions, 18 deletions

diff --git a/cmd/btrfs-ls-files/main.go b/cmd/btrfs-ls-files/main.go
index 375f427..9f5b85d 100644
--- a/cmd/btrfs-ls-files/main.go
+++ b/cmd/btrfs-ls-files/main.go
@@ -37,23 +37,12 @@ func Main(imgfilenames ...string) (err error) {
 		maybeSetErr(fs.Close())
 	}()
 
-	sb, err := fs.Superblock()
-	if err != nil {
-		return err
-	}
-
-	fsTreeRoot, err := fs.TreeLookup(sb.Data.RootTree, btrfs.Key{
+	printSubvol(fs, "", "", "/", btrfs.Key{
 		ObjectID: btrfs.FS_TREE_OBJECTID,
 		ItemType: btrfsitem.ROOT_ITEM_KEY,
 		Offset:   0,
 	})
-	if err != nil {
-		return fmt.Errorf("look up FS_TREE: %w", err)
-	}
-	fsTreeRootBody := fsTreeRoot.Body.(btrfsitem.Root)
-	fsTree := fsTreeRootBody.ByteNr
 
-	printDir(fs, fsTree, "", "", "/", fsTreeRootBody.RootDirID)
 	return nil
 }
 
@@ -64,6 +53,23 @@ const (
 	tL = "└── "
 )
 
+func printSubvol(fs *btrfs.FS, prefix0, prefix1, name string, key btrfs.Key) {
+	sb, err := fs.Superblock()
+	if err != nil {
+		fmt.Printf("%s%q error: could not read superblock: %v\n", prefix0, name, err)
+		return
+	}
+
+	root, err := fs.TreeLookup(sb.Data.RootTree, key)
+	if err != nil {
+		fmt.Printf("%s%q error: could not look up root %v: %v\n", prefix0, name, key, err)
+		return
+	}
+	rootBody := root.Body.(btrfsitem.Root)
+
+	printDir(fs, rootBody.ByteNr, prefix0, prefix1, name, rootBody.RootDirID)
+}
+
 func printDir(fs *btrfs.FS, fsTree btrfsvol.LogicalAddr, prefix0, prefix1, dirName string, dirInode btrfs.ObjID) {
 	var errs derror.MultiError
 	items, err := fs.TreeSearchAll(fsTree, func(key btrfs.Key) int {
@@ -176,7 +182,17 @@ func printDirEntry(fs *btrfs.FS, fsTree btrfsvol.LogicalAddr, prefix0, prefix1 s
 	}
 	switch entry.Type {
 	case btrfsitem.FT_DIR:
-		printDir(fs, fsTree, prefix0, prefix1, string(entry.Name), entry.Location.ObjectID)
+		switch entry.Location.ItemType {
+		case btrfsitem.INODE_ITEM_KEY:
+			printDir(fs, fsTree, prefix0, prefix1, string(entry.Name), entry.Location.ObjectID)
+		case btrfsitem.ROOT_ITEM_KEY:
+			key := entry.Location
+			key.Offset = 0
+			printSubvol(fs, prefix0, prefix1, string(entry.Name), key)
+		default:
+			fmt.Printf("%s%q\t[location=%v type=%v] error: I'm not sure how to print a %v directory\n",
+				prefix0, entry.Name, entry.Location, entry.Type, entry.Location.ItemType)
+		}
 	default:
 		fmt.Printf("%s%q\t[location=%v type=%v]\n", prefix0, entry.Name, entry.Location, entry.Type)
 	}
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()         {}
diff --git a/pkg/btrfs/internal/itemtype.go b/pkg/btrfs/internal/itemtype.go
index e4b1302..60731aa 100644
--- a/pkg/btrfs/internal/itemtype.go
+++ b/pkg/btrfs/internal/itemtype.go
@@ -26,7 +26,9 @@ const (
 	ORPHAN_ITEM_KEY          = ItemType(48)
 	PERSISTENT_ITEM_KEY      = ItemType(249)
 	QGROUP_RELATION_KEY      = ItemType(246)
+	ROOT_BACKREF_KEY         = ItemType(144)
 	ROOT_ITEM_KEY            = ItemType(132)
+	ROOT_REF_KEY             = ItemType(156)
 	SHARED_BLOCK_REF_KEY     = ItemType(182)
 	SHARED_DATA_REF_KEY      = ItemType(184)
 	TREE_BLOCK_REF_KEY       = ItemType(176)
@@ -57,7 +59,9 @@ func (t ItemType) String() string {
 		ORPHAN_ITEM_KEY:          "ORPHAN_ITEM",
 		PERSISTENT_ITEM_KEY:      "PERSISTENT_ITEM",
 		QGROUP_RELATION_KEY:      "QGROUP_RELATION",
+		ROOT_BACKREF_KEY:         "ROOT_BACKREF",
 		ROOT_ITEM_KEY:            "ROOT_ITEM",
+		ROOT_REF_KEY:             "ROOT_REF",
 		SHARED_BLOCK_REF_KEY:     "SHARED_BLOCK_REF",
 		SHARED_DATA_REF_KEY:      "SHARED_DATA_REF",
 		TREE_BLOCK_REF_KEY:       "TREE_BLOCK_REF",
diff --git a/pkg/btrfsmisc/print_tree.go b/pkg/btrfsmisc/print_tree.go
index 76eb19c..f78f653 100644
--- a/pkg/btrfsmisc/print_tree.go
+++ b/pkg/btrfsmisc/print_tree.go
@@ -97,10 +97,18 @@ func PrintTree(fs *btrfs.FS, root btrfsvol.LogicalAddr) error {
 					fmt.Printf("\t\tstime %v\n", fmtTime(body.STime))
 					fmt.Printf("\t\trtime %v\n", fmtTime(body.RTime))
 				}
-			//case btrfsitem.ROOT_REF_KEY:
-			//	// TODO
-			//case btrfsitem.ROOT_BACKREF_KEY:
-			//	// TODO
+			case btrfsitem.RootRef:
+				var tag string
+				switch item.Head.Key.ItemType {
+				case btrfsitem.ROOT_REF_KEY:
+					tag = "ref"
+				case btrfsitem.ROOT_BACKREF_KEY:
+					tag = "backref"
+				default:
+					tag = fmt.Sprintf("(error: unhandled RootRef item type: %v)", item.Head.Key.ItemType)
+				}
+				fmt.Printf("\t\troot %v key dirid %v sequence %v name %s\n",
+					tag, body.DirID, body.Sequence, body.Name)
 			case btrfsitem.Extent:
 				fmt.Printf("\t\trefs %v gen %v flags %v\n",
 					body.Head.Refs, body.Head.Generation, body.Head.Flags)
@@ -340,7 +348,7 @@ func FmtKey(key btrfs.Key) string {
 	case btrfsitem.QGROUP_RELATION_KEY: //TODO, btrfsitem.QGROUP_INFO_KEY, btrfsitem.QGROUP_LIMIT_KEY:
 		panic("not implemented")
 	case btrfsitem.UUID_SUBVOL_KEY, btrfsitem.UUID_RECEIVED_SUBVOL_KEY:
-		fmt.Fprintf(&out, " %v)", btrfsvol.PhysicalAddr(key.Offset))
+		fmt.Fprintf(&out, " %#08x)", key.Offset)
 	case btrfsitem.ROOT_ITEM_KEY:
 		fmt.Fprintf(&out, " %v)", btrfs.ObjID(key.Offset))
 	default: