Move subvol.go to btrfs/io3_fs.go

4 files changed, 93 insertions, 94 deletions

diff --git a/cmd/btrfs-mount/main.go b/cmd/btrfs-mount/main.go
index e059351..64cae30 100644
--- a/cmd/btrfs-mount/main.go
+++ b/cmd/btrfs-mount/main.go
@@ -71,10 +71,12 @@ func Main(ctx context.Context, mountpoint string, imgfilenames ...string) (err e
 	grp.Go("main", func(ctx context.Context) error {
 		defer atomic.StoreUint32(&mounted, 0)
 		rootSubvol := &Subvolume{
-			FS:         fs,
+			Subvolume: btrfs.Subvolume{
+				FS:     fs,
+				TreeID: btrfs.FS_TREE_OBJECTID,
+			},
 			DeviceName: tryAbs(imgfilenames[0]),
 			Mountpoint: mountpoint,
-			TreeID:     btrfs.FS_TREE_OBJECTID,
 		}
 		return rootSubvol.Run(ctx)
 	})
diff --git a/cmd/btrfs-mount/subvol_fuse.go b/cmd/btrfs-mount/subvol_fuse.go
index 6f3f267..1163e9f 100644
--- a/cmd/btrfs-mount/subvol_fuse.go
+++ b/cmd/btrfs-mount/subvol_fuse.go
@@ -6,6 +6,9 @@ import (
 	"sync/atomic"
 	"syscall"
 
+	"github.com/datawire/dlib/dcontext"
+	"github.com/datawire/dlib/dlog"
+	"github.com/jacobsa/fuse"
 	"github.com/jacobsa/fuse/fuseops"
 	"github.com/jacobsa/fuse/fuseutil"
 
@@ -15,21 +18,45 @@ import (
 )
 
 type dirState struct {
-	Dir *dir
+	Dir *btrfs.Dir
 }
 
 type fileState struct {
-	File *file
+	File *btrfs.File
 }
 
-type subvolumeFUSE struct {
+type Subvolume struct {
+	btrfs.Subvolume
+	DeviceName string
+	Mountpoint string
+
 	fuseutil.NotImplementedFileSystem
 	lastHandle  uint64
 	dirHandles  util.SyncMap[fuseops.HandleID, *dirState]
 	fileHandles util.SyncMap[fuseops.HandleID, *fileState]
 }
 
-func (sv *subvolumeFUSE) newHandle() fuseops.HandleID {
+func (sv *Subvolume) Run(ctx context.Context) error {
+	mount, err := fuse.Mount(
+		sv.Mountpoint,
+		fuseutil.NewFileSystemServer(sv),
+		&fuse.MountConfig{
+			OpContext:   ctx,
+			ErrorLogger: dlog.StdLogger(ctx, dlog.LogLevelError),
+			DebugLogger: dlog.StdLogger(ctx, dlog.LogLevelDebug),
+
+			FSName:  sv.DeviceName,
+			Subtype: "btrfs",
+
+			ReadOnly: true,
+		})
+	if err != nil {
+		return err
+	}
+	return mount.Join(dcontext.HardContext(ctx))
+}
+
+func (sv *Subvolume) newHandle() fuseops.HandleID {
 	return fuseops.HandleID(atomic.AddUint64(&sv.lastHandle, 1))
 }
 
@@ -73,14 +100,14 @@ func (sv *Subvolume) StatFS(_ context.Context, op *fuseops.StatFSOp) error {
 
 func (sv *Subvolume) LookUpInode(_ context.Context, op *fuseops.LookUpInodeOp) error {
 	if op.Parent == fuseops.RootInodeID {
-		parent, err := sv.getRootInode()
+		parent, err := sv.GetRootInode()
 		if err != nil {
 			return err
 		}
 		op.Parent = fuseops.InodeID(parent)
 	}
 
-	dir, err := sv.loadDir(btrfs.ObjID(op.Parent))
+	dir, err := sv.LoadDir(btrfs.ObjID(op.Parent))
 	if err != nil {
 		return err
 	}
@@ -91,7 +118,7 @@ func (sv *Subvolume) LookUpInode(_ context.Context, op *fuseops.LookUpInodeOp) e
 	if entry.Location.ItemType != btrfsitem.INODE_ITEM_KEY {
 		return fmt.Errorf("child %q is not an inode: %w", op.Name, syscall.ENOSYS)
 	}
-	bareInode, err := sv.loadBareInode(entry.Location.ObjectID)
+	bareInode, err := sv.LoadBareInode(entry.Location.ObjectID)
 	if err != nil {
 		return err
 	}
@@ -105,14 +132,14 @@ func (sv *Subvolume) LookUpInode(_ context.Context, op *fuseops.LookUpInodeOp) e
 
 func (sv *Subvolume) GetInodeAttributes(_ context.Context, op *fuseops.GetInodeAttributesOp) error {
 	if op.Inode == fuseops.RootInodeID {
-		inode, err := sv.getRootInode()
+		inode, err := sv.GetRootInode()
 		if err != nil {
 			return err
 		}
 		op.Inode = fuseops.InodeID(inode)
 	}
 
-	bareInode, err := sv.loadBareInode(btrfs.ObjID(op.Inode))
+	bareInode, err := sv.LoadBareInode(btrfs.ObjID(op.Inode))
 	if err != nil {
 		return err
 	}
@@ -123,14 +150,14 @@ func (sv *Subvolume) GetInodeAttributes(_ context.Context, op *fuseops.GetInodeA
 
 func (sv *Subvolume) OpenDir(_ context.Context, op *fuseops.OpenDirOp) error {
 	if op.Inode == fuseops.RootInodeID {
-		inode, err := sv.getRootInode()
+		inode, err := sv.GetRootInode()
 		if err != nil {
 			return err
 		}
 		op.Inode = fuseops.InodeID(inode)
 	}
 
-	dir, err := sv.loadDir(btrfs.ObjID(op.Inode))
+	dir, err := sv.LoadDir(btrfs.ObjID(op.Inode))
 	if err != nil {
 		return err
 	}
@@ -184,7 +211,7 @@ func (sv *Subvolume) ReleaseDirHandle(_ context.Context, op *fuseops.ReleaseDirH
 }
 
 func (sv *Subvolume) OpenFile(_ context.Context, op *fuseops.OpenFileOp) error {
-	file, err := sv.loadFile(btrfs.ObjID(op.Inode))
+	file, err := sv.LoadFile(btrfs.ObjID(op.Inode))
 	if err != nil {
 		return err
 	}
diff --git a/cmd/btrfs-mount/subvol.go b/pkg/btrfs/io3_fs.go
index 1d5e9db..a418b05 100644
--- a/cmd/btrfs-mount/subvol.go
+++ b/pkg/btrfs/io3_fs.go
@@ -1,89 +1,59 @@
-package main
+package btrfs
 
 import (
-	"context"
 	"fmt"
 	"io"
 	"reflect"
 	"sort"
 	"sync"
 
-	"github.com/datawire/dlib/dcontext"
 	"github.com/datawire/dlib/derror"
-	"github.com/datawire/dlib/dlog"
-	"github.com/jacobsa/fuse"
-	"github.com/jacobsa/fuse/fuseutil"
 
-	"lukeshu.com/btrfs-tools/pkg/btrfs"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsvol"
 	"lukeshu.com/btrfs-tools/pkg/util"
 )
 
-type bareInode struct {
-	Inode     btrfs.ObjID
+type BareInode struct {
+	Inode     ObjID
 	InodeItem *btrfsitem.Inode
 	Errs      derror.MultiError
 }
 
-type fullInode struct {
-	bareInode
-	OtherItems []btrfs.Item
+type FullInode struct {
+	BareInode
+	OtherItems []Item
 }
 
-type dir struct {
-	fullInode
+type Dir struct {
+	FullInode
 	ChildrenByName  map[string]btrfsitem.DirEntry
 	ChildrenByIndex map[uint64]btrfsitem.DirEntry
 }
 
-type fileExtent struct {
+type FileExtent struct {
 	OffsetWithinFile int64
 	btrfsitem.FileExtent
 }
 
-type file struct {
-	fullInode
-	Extents []fileExtent
-	FS      *btrfs.FS
+type File struct {
+	FullInode
+	Extents []FileExtent
+	FS      *FS
 }
 
 type Subvolume struct {
-	FS         *btrfs.FS
-	DeviceName string
-	Mountpoint string
-	TreeID     btrfs.ObjID
+	FS     *FS
+	TreeID ObjID
 
 	rootOnce sync.Once
 	rootVal  btrfsitem.Root
 	rootErr  error
 
-	bareInodeCache LRUCache[btrfs.ObjID, *bareInode]
-	fullInodeCache LRUCache[btrfs.ObjID, *fullInode]
-	dirCache       LRUCache[btrfs.ObjID, *dir]
-	fileCache      LRUCache[btrfs.ObjID, *file]
-
-	subvolumeFUSE
-}
-
-func (sv *Subvolume) Run(ctx context.Context) error {
-	mount, err := fuse.Mount(
-		sv.Mountpoint,
-		fuseutil.NewFileSystemServer(sv),
-		&fuse.MountConfig{
-			OpContext:   ctx,
-			ErrorLogger: dlog.StdLogger(ctx, dlog.LogLevelError),
-			DebugLogger: dlog.StdLogger(ctx, dlog.LogLevelDebug),
-
-			FSName:  sv.DeviceName,
-			Subtype: "btrfs",
-
-			ReadOnly: true,
-		})
-	if err != nil {
-		return err
-	}
-	return mount.Join(dcontext.HardContext(ctx))
+	bareInodeCache util.LRUCache[ObjID, *BareInode]
+	fullInodeCache util.LRUCache[ObjID, *FullInode]
+	dirCache       util.LRUCache[ObjID, *Dir]
+	fileCache      util.LRUCache[ObjID, *File]
 }
 
 func (sv *Subvolume) init() {
@@ -94,7 +64,7 @@ func (sv *Subvolume) init() {
 			return
 		}
 
-		root, err := sv.FS.TreeLookup(sb.Data.RootTree, btrfs.Key{
+		root, err := sv.FS.TreeLookup(sb.Data.RootTree, Key{
 			ObjectID: sv.TreeID,
 			ItemType: btrfsitem.ROOT_ITEM_KEY,
 			Offset:   0,
@@ -114,27 +84,27 @@ func (sv *Subvolume) init() {
 	})
 }
 
-func (sv *Subvolume) getRootInode() (btrfs.ObjID, error) {
+func (sv *Subvolume) GetRootInode() (ObjID, error) {
 	sv.init()
 	return sv.rootVal.RootDirID, sv.rootErr
 }
 
-func (sv *Subvolume) getFSTree() (btrfsvol.LogicalAddr, error) {
+func (sv *Subvolume) GetFSTree() (btrfsvol.LogicalAddr, error) {
 	sv.init()
 	return sv.rootVal.ByteNr, sv.rootErr
 }
 
-func (sv *Subvolume) loadBareInode(inode btrfs.ObjID) (*bareInode, error) {
-	val := sv.bareInodeCache.GetOrElse(inode, func() (val *bareInode) {
-		val = &bareInode{
+func (sv *Subvolume) LoadBareInode(inode ObjID) (*BareInode, error) {
+	val := sv.bareInodeCache.GetOrElse(inode, func() (val *BareInode) {
+		val = &BareInode{
 			Inode: inode,
 		}
-		tree, err := sv.getFSTree()
+		tree, err := sv.GetFSTree()
 		if err != nil {
 			val.Errs = append(val.Errs, err)
 			return
 		}
-		item, err := sv.FS.TreeLookup(tree, btrfs.Key{
+		item, err := sv.FS.TreeLookup(tree, Key{
 			ObjectID: inode,
 			ItemType: btrfsitem.INODE_ITEM_KEY,
 			Offset:   0,
@@ -159,19 +129,19 @@ func (sv *Subvolume) loadBareInode(inode btrfs.ObjID) (*bareInode, error) {
 	return val, nil
 }
 
-func (sv *Subvolume) loadFullInode(inode btrfs.ObjID) (*fullInode, error) {
-	val := sv.fullInodeCache.GetOrElse(inode, func() (val *fullInode) {
-		val = &fullInode{
-			bareInode: bareInode{
+func (sv *Subvolume) LoadFullInode(inode ObjID) (*FullInode, error) {
+	val := sv.fullInodeCache.GetOrElse(inode, func() (val *FullInode) {
+		val = &FullInode{
+			BareInode: BareInode{
 				Inode: inode,
 			},
 		}
-		tree, err := sv.getFSTree()
+		tree, err := sv.GetFSTree()
 		if err != nil {
 			val.Errs = append(val.Errs, err)
 			return
 		}
-		items, err := sv.FS.TreeSearchAll(tree, func(key btrfs.Key) int {
+		items, err := sv.FS.TreeSearchAll(tree, func(key Key) int {
 			return util.CmpUint(inode, key.ObjectID)
 		})
 		if err != nil {
@@ -203,15 +173,15 @@ func (sv *Subvolume) loadFullInode(inode btrfs.ObjID) (*fullInode, error) {
 	return val, nil
 }
 
-func (sv *Subvolume) loadDir(inode btrfs.ObjID) (*dir, error) {
-	val := sv.dirCache.GetOrElse(inode, func() (val *dir) {
-		val = new(dir)
-		fullInode, err := sv.loadFullInode(inode)
+func (sv *Subvolume) LoadDir(inode ObjID) (*Dir, error) {
+	val := sv.dirCache.GetOrElse(inode, func() (val *Dir) {
+		val = new(Dir)
+		fullInode, err := sv.LoadFullInode(inode)
 		if err != nil {
 			val.Errs = append(val.Errs, err)
 			return
 		}
-		val.fullInode = *fullInode
+		val.FullInode = *fullInode
 		val.populate()
 		return
 	})
@@ -221,7 +191,7 @@ func (sv *Subvolume) loadDir(inode btrfs.ObjID) (*dir, error) {
 	return val, nil
 }
 
-func (ret *dir) populate() {
+func (ret *Dir) populate() {
 	ret.ChildrenByName = make(map[string]btrfsitem.DirEntry)
 	ret.ChildrenByIndex = make(map[uint64]btrfsitem.DirEntry)
 	for _, item := range ret.OtherItems {
@@ -295,15 +265,15 @@ func (ret *dir) populate() {
 	return
 }
 
-func (sv *Subvolume) loadFile(inode btrfs.ObjID) (*file, error) {
-	val := sv.fileCache.GetOrElse(inode, func() (val *file) {
-		val = new(file)
-		fullInode, err := sv.loadFullInode(inode)
+func (sv *Subvolume) LoadFile(inode ObjID) (*File, error) {
+	val := sv.fileCache.GetOrElse(inode, func() (val *File) {
+		val = new(File)
+		fullInode, err := sv.LoadFullInode(inode)
 		if err != nil {
 			val.Errs = append(val.Errs, err)
 			return
 		}
-		val.fullInode = *fullInode
+		val.FullInode = *fullInode
 		val.FS = sv.FS
 		val.populate()
 		return
@@ -314,13 +284,13 @@ func (sv *Subvolume) loadFile(inode btrfs.ObjID) (*file, error) {
 	return val, nil
 }
 
-func (ret *file) populate() {
+func (ret *File) populate() {
 	for _, item := range ret.OtherItems {
 		switch item.Head.Key.ItemType {
 		case btrfsitem.INODE_REF_KEY:
 			// TODO
 		case btrfsitem.EXTENT_DATA_KEY:
-			ret.Extents = append(ret.Extents, fileExtent{
+			ret.Extents = append(ret.Extents, FileExtent{
 				OffsetWithinFile: int64(item.Head.Key.Offset),
 				FileExtent:       item.Body.(btrfsitem.FileExtent),
 			})
@@ -364,7 +334,7 @@ func (ret *file) populate() {
 	}
 }
 
-func (file *file) ReadAt(dat []byte, off int64) (int, error) {
+func (file *File) ReadAt(dat []byte, off int64) (int, error) {
 	// These stateles maybe-short-reads each do an O(n) extent
 	// lookup, so reading a file is O(n^2), but we expect n to be
 	// small, so whatev.  Turn file.Extents it in to an rbtree if
@@ -380,7 +350,7 @@ func (file *file) ReadAt(dat []byte, off int64) (int, error) {
 	return done, nil
 }
 
-func (file *file) maybeShortReadAt(dat []byte, off int64) (int, error) {
+func (file *File) maybeShortReadAt(dat []byte, off int64) (int, error) {
 	for _, extent := range file.Extents {
 		extBeg := extent.OffsetWithinFile
 		if extBeg > off {
@@ -409,4 +379,4 @@ func (file *file) maybeShortReadAt(dat []byte, off int64) (int, error) {
 	return 0, fmt.Errorf("read: could not map position %v", off)
 }
 
-var _ io.ReaderAt = (*file)(nil)
+var _ io.ReaderAt = (*File)(nil)
diff --git a/cmd/btrfs-mount/lru.go b/pkg/util/lru.go
index bf91c5e..2b62e69 100644
--- a/cmd/btrfs-mount/lru.go
+++ b/pkg/util/lru.go
@@ -1,4 +1,4 @@
-package main
+package util
 
 import (
 	"sync"