Merge lp:~sergiusens/goget-ubuntu-touch/unmapErr into lp:goget-ubuntu-touch

[Sergio Schvezov]

Expose unmap error after formatting

[John Lenton (chipaca)]

review: Approve

=== modified file 'diskimage/common.go'
--- diskimage/common.go	2015-06-23 10:23:50 +0000
+++ diskimage/common.go	2015-07-09 10:02:11 +0000
@@ -60,8 +60,6 @@
 	Unmount() error
 	Format() error
 	Partition() error
-	Map() error
-	Unmap() error
 	BaseMount() string
 }
 
@@ -200,7 +198,7 @@
 
 // Mount mounts the image. This also maps the loop device.
 func (img *BaseImage) Mount() error {
-	if err := img.Map(); err != nil {
+	if err := img.doMap(); err != nil {
 		return err
 	}
 
@@ -260,6 +258,12 @@
 
 // Unmount unmounts the image. This also unmaps the loop device.
 func (img *BaseImage) Unmount() error {
+	defer func() {
+		if isMapped(img.parts) {
+			fmt.Println("WARNING: could not unmap partitions")
+		}
+	}()
+
 	if img.baseMount == "" {
 		panic("No base mountpoint set")
 	}
@@ -285,11 +289,11 @@
 	}
 	img.baseMount = ""
 
-	return img.Unmap()
+	return img.doUnmap()
 }
 
-// Map maps the image to loop devices
-func (img *BaseImage) Map() error {
+// doMap maps the image to loop devices
+func (img *BaseImage) doMap() error {
 	if isMapped(img.parts) {
 		panic("cannot double map partitions")
 	}
@@ -332,8 +336,8 @@
 	return nil
 }
 
-//Unmap destroys loop devices for the partitions
-func (img *BaseImage) Unmap() error {
+// doUnmap destroys loop devices for the partitions
+func (img *BaseImage) doUnmap() error {
 	if img.baseMount != "" {
 		panic("cannot unmap mounted partitions")
 	}
@@ -355,7 +359,20 @@
 
 // Format formats the image following the partition types and labels them
 // accordingly.
-func (img BaseImage) Format() error {
+func (img BaseImage) Format() (err error) {
+	if err := img.doMap(); err != nil {
+		return err
+	}
+	defer func() {
+		if errUnmap := img.doUnmap(); errUnmap != nil {
+			if err == nil {
+				err = errUnmap
+			} else {
+				fmt.Println("WARNING: could not unmap partitions after error:", errUnmap)
+			}
+		}
+	}()
+
 	for _, part := range img.parts {
 		dev := filepath.Join("/dev/mapper", part.loop)
 

=== modified file 'ubuntu-device-flash/snappy.go'
--- ubuntu-device-flash/snappy.go	2015-06-24 12:53:54 +0000
+++ ubuntu-device-flash/snappy.go	2015-07-09 10:02:11 +0000
@@ -402,7 +402,8 @@
 	}
 	defer sysutils.DropPrivs()
 
-	if err := format(s.img); err != nil {
+	printOut("Formatting...")
+	if err := s.img.Format(); err != nil {
 		return err
 	}
 
@@ -413,17 +414,6 @@
 	return nil
 }
 
-func format(img diskimage.Image) error {
-	printOut("Mapping...")
-	if err := img.Map(); err != nil {
-		return fmt.Errorf("issue while mapping partitions: %s", err)
-	}
-	defer img.Unmap()
-
-	printOut("Formatting...")
-	return img.Format()
-}
-
 func (s Snapper) printSummary() {
 	fmt.Println("New image complete")
 	fmt.Println("Summary:")