Ensures files get closed properly. Closes #6213

Docker-DCO-1.1-Signed-off-by: Tibor Vass <teabee89@gmail.com> (github: tiborvass)

daemon/graphdriver/devmapper/README.md

@@ -4,7 +4,7 @@
 
 The device mapper graphdriver uses the device mapper thin provisioning
 module (dm-thinp) to implement CoW snapshots. For each devicemapper
-graph locaion (typically `/var/lib/docker/devicemapper`, $graph below)
+graph location (typically `/var/lib/docker/devicemapper`, $graph below)
 a thin pool is created based on two block devices, one for data and
 one for metadata.  By default these block devices are created
 automatically by using loopback mounts of automatically creates sparse

daemon/graphdriver/devmapper/deviceset.go

@@ -307,7 +307,6 @@ func (devices *DeviceSet) createFilesystem(info *DevInfo) error {
 		err = fmt.Errorf("Unsupported filesystem type %s", devices.filesystem)
 	}
 	if err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
@@ -317,12 +316,10 @@ func (devices *DeviceSet) createFilesystem(info *DevInfo) error {
 func (devices *DeviceSet) initMetaData() error {
 	_, _, _, params, err := getStatus(devices.getPoolName())
 	if err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
 	if _, err := fmt.Sscanf(params, "%d", &devices.TransactionId); err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 	devices.NewTransactionId = devices.TransactionId
@@ -331,7 +328,6 @@ func (devices *DeviceSet) initMetaData() error {
 
 	jsonData, err := ioutil.ReadFile(devices.oldMetadataFile())
 	if err != nil && !os.IsNotExist(err) {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
@@ -339,7 +335,6 @@ func (devices *DeviceSet) initMetaData() error {
 		m := MetaData{Devices: make(map[string]*DevInfo)}
 
 		if err := json.Unmarshal(jsonData, &m); err != nil {
-			utils.Debugf("\n--->Err: %s\n", err)
 			return err
 		}
 
@@ -389,7 +384,6 @@ func (devices *DeviceSet) setupBaseImage() error {
 	if oldInfo != nil && !oldInfo.Initialized {
 		utils.Debugf("Removing uninitialized base image")
 		if err := devices.deleteDevice(oldInfo); err != nil {
-			utils.Debugf("\n--->Err: %s\n", err)
 			return err
 		}
 	}
@@ -400,7 +394,6 @@ func (devices *DeviceSet) setupBaseImage() error {
 
 	// Create initial device
 	if err := createDevice(devices.getPoolDevName(), &id); err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
@@ -411,26 +404,22 @@ func (devices *DeviceSet) setupBaseImage() error {
 	info, err := devices.registerDevice(id, "", devices.baseFsSize)
 	if err != nil {
 		_ = deleteDevice(devices.getPoolDevName(), id)
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
 	utils.Debugf("Creating filesystem on base device-manager snapshot")
 
 	if err = devices.activateDeviceIfNeeded(info); err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
 	if err := devices.createFilesystem(info); err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
 	info.Initialized = true
 	if err = devices.saveMetadata(info); err != nil {
 		info.Initialized = false
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 
@@ -610,16 +599,15 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 
 			dataFile, err = attachLoopDevice(data)
 			if err != nil {
-				utils.Debugf("\n--->Err: %s\n", err)
 				return err
 			}
-			defer dataFile.Close()
 		} else {
 			dataFile, err = os.OpenFile(devices.dataDevice, os.O_RDWR, 0600)
 			if err != nil {
 				return err
 			}
 		}
+		defer dataFile.Close()
 
 		if devices.metadataDevice == "" {
 			// Make sure the sparse images exist in <root>/devicemapper/metadata
@@ -642,19 +630,17 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 
 			metadataFile, err = attachLoopDevice(metadata)
 			if err != nil {
-				utils.Debugf("\n--->Err: %s\n", err)
 				return err
 			}
-			defer metadataFile.Close()
 		} else {
 			metadataFile, err = os.OpenFile(devices.metadataDevice, os.O_RDWR, 0600)
 			if err != nil {
 				return err
 			}
 		}
+		defer metadataFile.Close()
 
 		if err := createPool(devices.getPoolName(), dataFile, metadataFile); err != nil {
-			utils.Debugf("\n--->Err: %s\n", err)
 			return err
 		}
 	}
@@ -663,7 +649,6 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 	// load the transaction id and migrate old metadata
 	if !createdLoopback {
 		if err = devices.initMetaData(); err != nil {
-			utils.Debugf("\n--->Err: %s\n", err)
 			return err
 		}
 	}
@@ -775,7 +760,6 @@ func (devices *DeviceSet) deactivatePool() error {
 	devname := devices.getPoolDevName()
 	devinfo, err := getInfo(devname)
 	if err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 	if devinfo.Exists != 0 {
@@ -797,12 +781,10 @@ func (devices *DeviceSet) deactivateDevice(info *DevInfo) error {
 
 	devinfo, err := getInfo(info.Name())
 	if err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 	if devinfo.Exists != 0 {
 		if err := devices.removeDeviceAndWait(info.Name()); err != nil {
-			utils.Debugf("\n--->Err: %s\n", err)
 			return err
 		}
 	}
@@ -1032,7 +1014,6 @@ func (devices *DeviceSet) UnmountDevice(hash string) error {
 
 	utils.Debugf("[devmapper] Unmount(%s)", info.mountPath)
 	if err := syscall.Unmount(info.mountPath, 0); err != nil {
-		utils.Debugf("\n--->Err: %s\n", err)
 		return err
 	}
 	utils.Debugf("[devmapper] Unmount done")