diskio.File: Add .Close() and don't have .Size() return an error

9 files changed, 88 insertions, 56 deletions

diff --git a/lib/btrfs/btrfsvol/lvm.go b/lib/btrfs/btrfsvol/lvm.go
index 4d40ccd..149c8cd 100644
--- a/lib/btrfs/btrfsvol/lvm.go
+++ b/lib/btrfs/btrfsvol/lvm.go
@@ -10,6 +10,8 @@ import (
 	"os"
 	"reflect"
 
+	"github.com/datawire/dlib/derror"
+
 	"git.lukeshu.com/btrfs-progs-ng/lib/containers"
 	"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
 )
@@ -58,15 +60,27 @@ func (lv *LogicalVolume[PhysicalVolume]) Name() string {
 	return lv.name
 }
 
-func (lv *LogicalVolume[PhysicalVolume]) Size() (LogicalAddr, error) {
+func (lv *LogicalVolume[PhysicalVolume]) Size() LogicalAddr {
 	lv.init()
 	lastChunk := lv.logical2physical.Max()
 	if lastChunk == nil {
-		return 0, nil
+		return 0
 	}
-	return lastChunk.Value.LAddr.Add(lastChunk.Value.Size), nil
+	return lastChunk.Value.LAddr.Add(lastChunk.Value.Size)
 }
 
+func (lv *LogicalVolume[PhysicalVolume]) Close() error {
+	var errs derror.MultiError
+	for _, dev := range lv.id2pv {
+		if err := dev.Close(); err != nil && err == nil {
+			errs = append(errs, err)
+		}
+	}
+	if errs != nil {
+		return errs
+	}
+	return nil
+}
 func (lv *LogicalVolume[PhysicalVolume]) AddPhysicalVolume(id DeviceID, dev PhysicalVolume) error {
 	lv.init()
 	if other, exists := lv.id2pv[id]; exists {
diff --git a/lib/btrfs/io1_pv.go b/lib/btrfs/io1_pv.go
index 10b6e32..df31671 100644
--- a/lib/btrfs/io1_pv.go
+++ b/lib/btrfs/io1_pv.go
@@ -6,7 +6,6 @@ package btrfs
 
 import (
 	"fmt"
-	"os"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
@@ -14,7 +13,7 @@ import (
 )
 
 type Device struct {
-	*os.File
+	diskio.File[btrfsvol.PhysicalAddr]
 
 	cacheSuperblocks []*diskio.Ref[btrfsvol.PhysicalAddr, Superblock]
 	cacheSuperblock  *Superblock
@@ -22,22 +21,6 @@ type Device struct {
 
 var _ diskio.File[btrfsvol.PhysicalAddr] = (*Device)(nil)
 
-func (dev Device) Size() (btrfsvol.PhysicalAddr, error) {
-	fi, err := dev.Stat()
-	if err != nil {
-		return 0, err
-	}
-	return btrfsvol.PhysicalAddr(fi.Size()), nil
-}
-
-func (dev *Device) ReadAt(dat []byte, paddr btrfsvol.PhysicalAddr) (int, error) {
-	return dev.File.ReadAt(dat, int64(paddr))
-}
-
-func (dev *Device) WriteAt(dat []byte, paddr btrfsvol.PhysicalAddr) (int, error) {
-	return dev.File.WriteAt(dat, int64(paddr))
-}
-
 var SuperblockAddrs = []btrfsvol.PhysicalAddr{
 	0x00_0001_0000, // 64KiB
 	0x00_0400_0000, // 64MiB
@@ -50,10 +33,7 @@ func (dev *Device) Superblocks() ([]*diskio.Ref[btrfsvol.PhysicalAddr, Superbloc
 	}
 	superblockSize := btrfsvol.PhysicalAddr(binstruct.StaticSize(Superblock{}))
 
-	sz, err := dev.Size()
-	if err != nil {
-		return nil, err
-	}
+	sz := dev.Size()
 
 	var ret []*diskio.Ref[btrfsvol.PhysicalAddr, Superblock]
 	for i, addr := range SuperblockAddrs {
diff --git a/lib/btrfs/io2_lv.go b/lib/btrfs/io2_lv.go
index 47ab474..9316e27 100644
--- a/lib/btrfs/io2_lv.go
+++ b/lib/btrfs/io2_lv.go
@@ -57,7 +57,7 @@ func (fs *FS) Name() string {
 	return name
 }
 
-func (fs *FS) Size() (btrfsvol.LogicalAddr, error) {
+func (fs *FS) Size() btrfsvol.LogicalAddr {
 	return fs.LV.Size()
 }
 
@@ -185,16 +185,7 @@ func (fs *FS) initDev(ctx context.Context, sb Superblock) error {
 }
 
 func (fs *FS) Close() error {
-	var errs derror.MultiError
-	for _, dev := range fs.LV.PhysicalVolumes() {
-		if err := dev.Close(); err != nil && err == nil {
-			errs = append(errs, err)
-		}
-	}
-	if errs != nil {
-		return errs
-	}
-	return nil
+	return fs.LV.Close()
 }
 
 var _ io.Closer = (*FS)(nil)
diff --git a/lib/btrfsprogs/btrfsinspect/recoverchunks.go b/lib/btrfsprogs/btrfsinspect/recoverchunks.go
index 27ac85b..257a4fd 100644
--- a/lib/btrfsprogs/btrfsinspect/recoverchunks.go
+++ b/lib/btrfsprogs/btrfsinspect/recoverchunks.go
@@ -155,7 +155,7 @@ func ScanOneDev(ctx context.Context, dev *btrfs.Device, superblock btrfs.Superbl
 		FoundNodes: make(map[btrfsvol.LogicalAddr][]btrfsvol.PhysicalAddr),
 	}
 
-	devSize, _ := dev.Size()
+	devSize := dev.Size()
 	lastProgress := -1
 
 	err := btrfsutil.ScanForNodes(ctx, dev, superblock, func(nodeRef *diskio.Ref[btrfsvol.PhysicalAddr, btrfs.Node], err error) {
diff --git a/lib/btrfsprogs/btrfsutil/open.go b/lib/btrfsprogs/btrfsutil/open.go
index c237b54..0f3b32a 100644
--- a/lib/btrfsprogs/btrfsutil/open.go
+++ b/lib/btrfsprogs/btrfsutil/open.go
@@ -12,18 +12,26 @@ import (
 	"github.com/datawire/dlib/dlog"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol"
+	"git.lukeshu.com/btrfs-progs-ng/lib/diskio"
 )
 
 func Open(ctx context.Context, flag int, filenames ...string) (*btrfs.FS, error) {
 	fs := new(btrfs.FS)
 	for i, filename := range filenames {
 		dlog.Debugf(ctx, "Adding device file %d/%d %q...", i, len(filenames), filename)
-		fh, err := os.OpenFile(filename, flag, 0)
+		osFile, err := os.OpenFile(filename, flag, 0)
 		if err != nil {
 			_ = fs.Close()
 			return nil, fmt.Errorf("device file %q: %w", filename, err)
 		}
-		if err := fs.AddDevice(ctx, &btrfs.Device{File: fh}); err != nil {
+		typedFile := &diskio.OSFile[btrfsvol.PhysicalAddr]{
+			File: osFile,
+		}
+		devFile := &btrfs.Device{
+			File: typedFile,
+		}
+		if err := fs.AddDevice(ctx, devFile); err != nil {
 			return nil, fmt.Errorf("device file %q: %w", filename, err)
 		}
 	}
diff --git a/lib/btrfsprogs/btrfsutil/scan.go b/lib/btrfsprogs/btrfsutil/scan.go
index dd77747..d5d3d8d 100644
--- a/lib/btrfsprogs/btrfsutil/scan.go
+++ b/lib/btrfsprogs/btrfsutil/scan.go
@@ -20,10 +20,7 @@ import (
 // doing something itself when it finds a node, it simply calls a
 // callback function.
 func ScanForNodes(ctx context.Context, dev *btrfs.Device, sb btrfs.Superblock, fn func(*diskio.Ref[btrfsvol.PhysicalAddr, btrfs.Node], error), prog func(btrfsvol.PhysicalAddr)) error {
-	devSize, err := dev.Size()
-	if err != nil {
-		return err
-	}
+	devSize := dev.Size()
 
 	if sb.NodeSize < sb.SectorSize {
 		return fmt.Errorf("node_size(%v) < sector_size(%v)",
diff --git a/lib/diskio/file_iface.go b/lib/diskio/file_iface.go
new file mode 100644
index 0000000..206db0c
--- /dev/null
+++ b/lib/diskio/file_iface.go
@@ -0,0 +1,24 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package diskio
+
+import (
+	"io"
+)
+
+type File[A ~int64] interface {
+	Name() string
+	Size() A
+	Close() error
+	ReadAt(p []byte, off A) (n int, err error)
+	WriteAt(p []byte, off A) (n int, err error)
+}
+
+type assertAddr int64
+
+var (
+	_ io.WriterAt = File[int64](nil)
+	_ io.ReaderAt = File[int64](nil)
+)
diff --git a/lib/diskio/file_os.go b/lib/diskio/file_os.go
new file mode 100644
index 0000000..2fa521d
--- /dev/null
+++ b/lib/diskio/file_os.go
@@ -0,0 +1,31 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package diskio
+
+import (
+	"os"
+)
+
+type OSFile[A ~int64] struct {
+	*os.File
+}
+
+var _ File[assertAddr] = (*OSFile[assertAddr])(nil)
+
+func (f *OSFile[A]) Size() A {
+	fi, err := f.Stat()
+	if err != nil {
+		return 0
+	}
+	return A(fi.Size())
+}
+
+func (f *OSFile[A]) ReadAt(dat []byte, paddr A) (int, error) {
+	return f.File.ReadAt(dat, int64(paddr))
+}
+
+func (f *OSFile[A]) WriteAt(dat []byte, paddr A) (int, error) {
+	return f.File.WriteAt(dat, int64(paddr))
+}
diff --git a/lib/diskio/ref.go b/lib/diskio/ref.go
index 9782743..137701d 100644
--- a/lib/diskio/ref.go
+++ b/lib/diskio/ref.go
@@ -6,23 +6,10 @@ package diskio
 
 import (
 	"fmt"
-	"io"
 
 	"git.lukeshu.com/btrfs-progs-ng/lib/binstruct"
 )
 
-type File[A ~int64] interface {
-	Name() string
-	Size() (A, error)
-	ReadAt(p []byte, off A) (n int, err error)
-	WriteAt(p []byte, off A) (n int, err error)
-}
-
-var (
-	_ io.WriterAt = File[int64](nil)
-	_ io.ReaderAt = File[int64](nil)
-)
-
 type Ref[A ~int64, T any] struct {
 	File File[A]
 	Addr A