subvolumes working, kinda

5 files changed, 57 insertions, 42 deletions

diff --git a/pkg/btrfs/btrfsitem/item_inoderef.go b/pkg/btrfs/btrfsitem/item_inoderef.go
index 78dd677..2c26df6 100644
--- a/pkg/btrfs/btrfsitem/item_inoderef.go
+++ b/pkg/btrfs/btrfsitem/item_inoderef.go
@@ -4,36 +4,9 @@ import (
 	"lukeshu.com/btrfs-tools/pkg/binstruct"
 )
 
-type InodeRefList []InodeRef // INODE_REF=12
-
-func (o *InodeRefList) UnmarshalBinary(dat []byte) (int, error) {
-	*o = nil
-	n := 0
-	for n < len(dat) {
-		var ref InodeRef
-		_n, err := binstruct.Unmarshal(dat, &ref)
-		n += _n
-		if err != nil {
-			return n, err
-		}
-		*o = append(*o, ref)
-	}
-	return n, nil
-}
-
-func (o InodeRefList) MarshalBinary() ([]byte, error) {
-	var ret []byte
-	for _, ref := range o {
-		bs, err := binstruct.Marshal(ref)
-		ret = append(ret, bs...)
-		if err != nil {
-			return ret, err
-		}
-	}
-	return ret, nil
-}
-
-type InodeRef struct {
+// key.objectid = inode number of the file
+// key.offset = inode number of the parent file
+type InodeRef struct { // INODE_REF=12
 	Index         int64  `bin:"off=0x0, siz=0x8"`
 	NameLen       uint16 `bin:"off=0x8, siz=0x2"` // [ignored-when-writing]
 	binstruct.End `bin:"off=0xa"`
diff --git a/pkg/btrfs/btrfsitem/items.txt b/pkg/btrfs/btrfsitem/items.txt
index 2820788..7898775 100644
--- a/pkg/btrfs/btrfsitem/items.txt
+++ b/pkg/btrfs/btrfsitem/items.txt
@@ -12,7 +12,7 @@ FREE_SPACE_BITMAP=200 FreeSpaceBitmap
 FREE_SPACE_EXTENT=199 Empty
 FREE_SPACE_INFO=198 FreeSpaceInfo
 INODE_ITEM=1 Inode
-INODE_REF=12 InodeRefList
+INODE_REF=12 InodeRef
 METADATA_ITEM=169 Metadata
 ORPHAN_ITEM=48 Empty
 PERSISTENT_ITEM=249 DevStats
diff --git a/pkg/btrfs/btrfsitem/items_gen.go b/pkg/btrfs/btrfsitem/items_gen.go
index 030202b..b5b64bd 100644
--- a/pkg/btrfs/btrfsitem/items_gen.go
+++ b/pkg/btrfs/btrfsitem/items_gen.go
@@ -55,7 +55,7 @@ var keytype2gotype = map[Type]reflect.Type{
 	FREE_SPACE_EXTENT_KEY:    reflect.TypeOf(Empty{}),
 	FREE_SPACE_INFO_KEY:      reflect.TypeOf(FreeSpaceInfo{}),
 	INODE_ITEM_KEY:           reflect.TypeOf(Inode{}),
-	INODE_REF_KEY:            reflect.TypeOf(InodeRefList{}),
+	INODE_REF_KEY:            reflect.TypeOf(InodeRef{}),
 	METADATA_ITEM_KEY:        reflect.TypeOf(Metadata{}),
 	ORPHAN_ITEM_KEY:          reflect.TypeOf(Empty{}),
 	PERSISTENT_ITEM_KEY:      reflect.TypeOf(DevStats{}),
@@ -89,7 +89,7 @@ func (FreeSpaceBitmap) isItem() {}
 func (FreeSpaceHeader) isItem() {}
 func (FreeSpaceInfo) isItem()   {}
 func (Inode) isItem()           {}
-func (InodeRefList) isItem()    {}
+func (InodeRef) isItem()        {}
 func (Metadata) isItem()        {}
 func (Root) isItem()            {}
 func (RootRef) isItem()         {}
diff --git a/pkg/btrfs/io3_fs.go b/pkg/btrfs/io3_fs.go
index a418b05..75b973b 100644
--- a/pkg/btrfs/io3_fs.go
+++ b/pkg/btrfs/io3_fs.go
@@ -3,6 +3,7 @@ package btrfs
 import (
 	"fmt"
 	"io"
+	"path/filepath"
 	"reflect"
 	"sort"
 	"sync"
@@ -25,10 +26,17 @@ type FullInode struct {
 	OtherItems []Item
 }
 
+type InodeRef struct {
+	Inode ObjID
+	btrfsitem.InodeRef
+}
+
 type Dir struct {
 	FullInode
+	DotDot          *InodeRef
 	ChildrenByName  map[string]btrfsitem.DirEntry
 	ChildrenByIndex map[uint64]btrfsitem.DirEntry
+	SV              *Subvolume
 }
 
 type FileExtent struct {
@@ -39,7 +47,7 @@ type FileExtent struct {
 type File struct {
 	FullInode
 	Extents []FileExtent
-	FS      *FS
+	SV      *Subvolume
 }
 
 type Subvolume struct {
@@ -182,6 +190,7 @@ func (sv *Subvolume) LoadDir(inode ObjID) (*Dir, error) {
 			return
 		}
 		val.FullInode = *fullInode
+		val.SV = sv
 		val.populate()
 		return
 	})
@@ -197,7 +206,17 @@ func (ret *Dir) populate() {
 	for _, item := range ret.OtherItems {
 		switch item.Head.Key.ItemType {
 		case btrfsitem.INODE_REF_KEY:
-			// TODO
+			ref := InodeRef{
+				Inode:    ObjID(item.Head.Key.Offset),
+				InodeRef: item.Body.(btrfsitem.InodeRef),
+			}
+			if ret.DotDot != nil {
+				if !reflect.DeepEqual(ref, *ret.DotDot) {
+					ret.Errs = append(ret.Errs, fmt.Errorf("multiple INODE_REF items on a directory"))
+				}
+				continue
+			}
+			ret.DotDot = &ref
 		case btrfsitem.DIR_ITEM_KEY:
 			body := item.Body.(btrfsitem.DirEntries)
 			if len(body) != 1 {
@@ -265,6 +284,28 @@ func (ret *Dir) populate() {
 	return
 }
 
+func (dir *Dir) AbsPath() (string, error) {
+	rootInode, err := dir.SV.GetRootInode()
+	if err != nil {
+		return "", err
+	}
+	if rootInode == dir.Inode {
+		return "/", nil
+	}
+	if dir.DotDot == nil {
+		return "", fmt.Errorf("missing .. entry in dir inode %v", dir.Inode)
+	}
+	parent, err := dir.SV.LoadDir(dir.DotDot.Inode)
+	if err != nil {
+		return "", err
+	}
+	parentName, err := parent.AbsPath()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(parentName, string(dir.DotDot.Name)), nil
+}
+
 func (sv *Subvolume) LoadFile(inode ObjID) (*File, error) {
 	val := sv.fileCache.GetOrElse(inode, func() (val *File) {
 		val = new(File)
@@ -274,7 +315,7 @@ func (sv *Subvolume) LoadFile(inode ObjID) (*File, error) {
 			return
 		}
 		val.FullInode = *fullInode
-		val.FS = sv.FS
+		val.SV = sv
 		val.populate()
 		return
 	})
@@ -370,12 +411,15 @@ func (file *File) maybeShortReadAt(dat []byte, off int64) (int, error) {
 		case btrfsitem.FILE_EXTENT_INLINE:
 			return copy(dat, extent.BodyInline[offsetWithinExt:offsetWithinExt+readSize]), nil
 		case btrfsitem.FILE_EXTENT_REG, btrfsitem.FILE_EXTENT_PREALLOC:
-			return file.FS.ReadAt(dat[:readSize],
+			return file.SV.FS.ReadAt(dat[:readSize],
 				extent.BodyExtent.DiskByteNr.
 					Add(extent.BodyExtent.Offset).
 					Add(btrfsvol.AddrDelta(offsetWithinExt)))
 		}
 	}
+	if file.InodeItem != nil && off >= file.InodeItem.Size {
+		return 0, io.EOF
+	}
 	return 0, fmt.Errorf("read: could not map position %v", off)
 }
 
diff --git a/pkg/btrfsmisc/print_tree.go b/pkg/btrfsmisc/print_tree.go
index 61c5423..c03cb4a 100644
--- a/pkg/btrfsmisc/print_tree.go
+++ b/pkg/btrfsmisc/print_tree.go
@@ -57,11 +57,9 @@ func PrintTree(fs *btrfs.FS, root btrfsvol.LogicalAddr) error {
 				fmt.Printf("\t\tctime %v\n", fmtTime(body.CTime))
 				fmt.Printf("\t\tmtime %v\n", fmtTime(body.MTime))
 				fmt.Printf("\t\totime %v\n", fmtTime(body.OTime))
-			case btrfsitem.InodeRefList:
-				for _, ref := range body {
-					fmt.Printf("\t\tindex %v namelen %v name: %s\n",
-						ref.Index, ref.NameLen, ref.Name)
-				}
+			case btrfsitem.InodeRef:
+				fmt.Printf("\t\tindex %v namelen %v name: %s\n",
+					body.Index, body.NameLen, body.Name)
 			//case btrfsitem.INODE_EXTREF_KEY:
 			//	// TODO
 			case btrfsitem.DirEntries: