add open/close utility functions

6 files changed, 70 insertions, 44 deletions

diff --git a/cmd/btrfs-dbg/main.go b/cmd/btrfs-dbg/main.go
index 3f30915..4b4a7a2 100644
--- a/cmd/btrfs-dbg/main.go
+++ b/cmd/btrfs-dbg/main.go
@@ -25,20 +25,13 @@ func Main(imgfilename string) (err error) {
 		}
 	}
 
-	fh, err := os.Open(imgfilename)
+	fs, err := btrfsmisc.Open(os.O_RDONLY, imgfilename)
 	if err != nil {
 		return err
 	}
 	defer func() {
-		maybeSetErr(fh.Close())
+		maybeSetErr(fs.Close())
 	}()
-	dev := &btrfs.Device{
-		File: fh,
-	}
-	fs := new(btrfs.FS)
-	if err := fs.AddDevice(dev); err != nil {
-		return err
-	}
 
 	superblocks, err := fs.Superblocks()
 	if err != nil {
@@ -61,17 +54,19 @@ func Main(imgfilename string) (err error) {
 	}
 	spew.Dump(syschunks)
 
-	if err := btrfsmisc.ScanForNodes(dev, superblocks[0].Data, func(nodeRef *util.Ref[btrfs.PhysicalAddr, btrfs.Node], err error) {
-		if err != nil {
-			fmt.Println(err)
-		} else {
-			fmt.Printf("node@%v: physical_addr=%v logical_addr=%v generation=%v owner=%v level=%v\n",
-				nodeRef.Addr,
-				nodeRef.Addr, nodeRef.Data.Head.Addr,
-				nodeRef.Data.Head.Generation, nodeRef.Data.Head.Owner, nodeRef.Data.Head.Level)
+	for _, dev := range fs.LV.PhysicalVolumes() {
+		if err := btrfsmisc.ScanForNodes(dev, superblocks[0].Data, func(nodeRef *util.Ref[btrfs.PhysicalAddr, btrfs.Node], err error) {
+			if err != nil {
+				fmt.Println(err)
+			} else {
+				fmt.Printf("node@%v: physical_addr=%v logical_addr=%v generation=%v owner=%v level=%v\n",
+					nodeRef.Addr,
+					nodeRef.Addr, nodeRef.Data.Head.Addr,
+					nodeRef.Data.Head.Generation, nodeRef.Data.Head.Owner, nodeRef.Data.Head.Level)
+			}
+		}, nil); err != nil {
+			return err
 		}
-	}, nil); err != nil {
-		return err
 	}
 
 	return nil
diff --git a/cmd/btrfs-dump-tree/main.go b/cmd/btrfs-dump-tree/main.go
index ded7a39..b226af3 100644
--- a/cmd/btrfs-dump-tree/main.go
+++ b/cmd/btrfs-dump-tree/main.go
@@ -25,19 +25,14 @@ func Main(imgfilename string) (err error) {
 		}
 	}
 
-	fh, err := os.Open(imgfilename)
+	fs, err := btrfsmisc.Open(os.O_RDONLY, imgfilename)
 	if err != nil {
 		return err
 	}
 	defer func() {
-		maybeSetErr(fh.Close())
+		maybeSetErr(fs.Close())
 	}()
 
-	fs := new(btrfs.FS)
-	if err := fs.AddDevice(&btrfs.Device{File: fh}); err != nil {
-		fmt.Printf("(error) %v\n", err)
-	}
-
 	superblock, err := fs.Superblock()
 	if err != nil {
 		return err
diff --git a/cmd/btrfs-fsck/main.go b/cmd/btrfs-fsck/main.go
index e51aae9..ebbaff7 100644
--- a/cmd/btrfs-fsck/main.go
+++ b/cmd/btrfs-fsck/main.go
@@ -19,22 +19,13 @@ func Main(imgfilenames ...string) (err error) {
 		}
 	}
 
-	var imgfiles []*os.File
-	for _, imgfilename := range imgfilenames {
-		fh, err := os.OpenFile(imgfilename, os.O_RDWR, 0)
-		if err != nil {
-			return err
-		}
-		defer func() {
-			maybeSetErr(fh.Close())
-		}()
-		imgfiles = append(imgfiles, fh)
-	}
-
-	fs, sb, err := pass0(imgfiles...)
+	fs, sb, err := pass0(imgfilenames...)
 	if err != nil {
 		return err
 	}
+	defer func() {
+		maybeSetErr(fs.Close())
+	}()
 
 	foundNodes, err := pass1(fs, sb)
 	if err != nil {
diff --git a/cmd/btrfs-fsck/pass0.go b/cmd/btrfs-fsck/pass0.go
index 2a8e20a..c0c872b 100644
--- a/cmd/btrfs-fsck/pass0.go
+++ b/cmd/btrfs-fsck/pass0.go
@@ -8,19 +8,27 @@ import (
 	"lukeshu.com/btrfs-tools/pkg/util"
 )
 
-func pass0(imgfiles ...*os.File) (*btrfs.FS, *util.Ref[btrfs.PhysicalAddr, btrfs.Superblock], error) {
+func pass0(filenames ...string) (*btrfs.FS, *util.Ref[btrfs.PhysicalAddr, btrfs.Superblock], error) {
 	fmt.Printf("\nPass 0: init and superblocks...\n")
 
 	fs := new(btrfs.FS)
-	for _, imgfile := range imgfiles {
-		fmt.Printf("Pass 0: ... adding device %q...\n", imgfile.Name())
-		if err := fs.AddDevice(&btrfs.Device{File: imgfile}); err != nil {
-			fmt.Printf("Pass 0: ... add device %q: error: %v\n", imgfile.Name(), err)
+	for _, filename := range filenames {
+		fmt.Printf("Pass 0: ... adding device %q...\n", filename)
+
+		fh, err := os.OpenFile(filename, os.O_RDWR, 0)
+		if err != nil {
+			_ = fs.Close()
+			return nil, nil, fmt.Errorf("device %q: %w", filename, err)
+		}
+
+		if err := fs.AddDevice(&btrfs.Device{File: fh}); err != nil {
+			fmt.Printf("Pass 0: ... add device %q: error: %v\n", filename, err)
 		}
 	}
 
 	sb, err := fs.Superblock()
 	if err != nil {
+		_ = fs.Close()
 		return nil, nil, err
 	}
 
diff --git a/pkg/btrfs/io2_fs.go b/pkg/btrfs/io2_fs.go
index dcf7df8..740e6e6 100644
--- a/pkg/btrfs/io2_fs.go
+++ b/pkg/btrfs/io2_fs.go
@@ -2,6 +2,7 @@ package btrfs
 
 import (
 	"fmt"
+	"io"
 
 	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsitem"
 	"lukeshu.com/btrfs-tools/pkg/btrfs/btrfsvol"
@@ -166,3 +167,15 @@ func (fs *FS) initDev(sb *util.Ref[PhysicalAddr, Superblock]) error {
 	}
 	return nil
 }
+
+func (fs *FS) Close() error {
+	var err error
+	for _, dev := range fs.LV.PhysicalVolumes() {
+		if _err := dev.Close(); _err != nil && err == nil {
+			err = _err
+		}
+	}
+	return err
+}
+
+var _ io.Closer = (*FS)(nil)
diff --git a/pkg/btrfsmisc/open.go b/pkg/btrfsmisc/open.go
new file mode 100644
index 0000000..bf72670
--- /dev/null
+++ b/pkg/btrfsmisc/open.go
@@ -0,0 +1,24 @@
+package btrfsmisc
+
+import (
+	"fmt"
+	"os"
+
+	"lukeshu.com/btrfs-tools/pkg/btrfs"
+)
+
+func Open(flag int, filenames ...string) (*btrfs.FS, error) {
+	fs := new(btrfs.FS)
+	for _, filename := range filenames {
+		fh, err := os.OpenFile(filename, flag, 0)
+		if err != nil {
+			_ = fs.Close()
+			return nil, fmt.Errorf("file %q: %w", filename, err)
+		}
+		if err := fs.AddDevice(&btrfs.Device{File: fh}); err != nil {
+			_ = fs.Close()
+			return nil, fmt.Errorf("file %q: %w", filename, err)
+		}
+	}
+	return fs, nil
+}