devmapper: Update device-mapper-tool

This makes the device mapper tool work again and adds new features
to get pool status, device status and to list all devices.

graphdriver/devmapper/deviceset.go

@@ -57,6 +57,16 @@ type Status struct {
 	MetadataLoopback string
 	Data             DiskUsage
 	Metadata         DiskUsage
+	SectorSize       uint64
+}
+
+type DevStatus struct {
+	DeviceId            int
+	Size                uint64
+	TransactionId       uint64
+	SizeInSectors       uint64
+	MappedSectors       uint64
+	HighestMappedSector uint64
 }
 
 func getDevName(name string) string {
@@ -357,13 +367,24 @@ func minor(device uint64) uint64 {
 	return (device & 0xff) | ((device >> 12) & 0xfff00)
 }
 
-func (devices *DeviceSet) initDevmapper() error {
+func (devices *DeviceSet) initDevmapper(doInit bool) error {
 	logInit(devices)
 
 	// Make sure the sparse images exist in <root>/devicemapper/data and
 	// <root>/devicemapper/metadata
 
-	createdLoopback := !devices.hasImage("data") || !devices.hasImage("metadata")
+	hasData := devices.hasImage("data")
+	hasMetadata := devices.hasImage("metadata")
+
+	if !doInit && !hasData {
+		return fmt.Errorf("Looback data file not found %s")
+	}
+
+	if !doInit && !hasMetadata {
+		return fmt.Errorf("Looback metadata file not found %s")
+	}
+
+	createdLoopback := !hasData || !hasMetadata
 	data, err := devices.ensureImage("data", DefaultDataLoopbackSize)
 	if err != nil {
 		utils.Debugf("Error device ensureImage (data): %s\n", err)
@@ -438,9 +459,11 @@ func (devices *DeviceSet) initDevmapper() error {
 	}
 
 	// Setup the base image
-	if err := devices.setupBaseImage(); err != nil {
-		utils.Debugf("Error device setupBaseImage: %s\n", err)
-		return err
+	if doInit {
+		if err := devices.setupBaseImage(); err != nil {
+			utils.Debugf("Error device setupBaseImage: %s\n", err)
+			return err
+		}
 	}
 
 	return nil
@@ -757,6 +780,69 @@ func (devices *DeviceSet) setInitialized(hash string) error {
 	return nil
 }
 
+func (devices *DeviceSet) List() []string {
+	devices.Lock()
+	defer devices.Unlock()
+
+	ids := make([]string, len(devices.Devices))
+	i := 0
+	for k := range devices.Devices {
+		ids[i] = k
+		i++
+	}
+	return ids
+}
+
+func (devices *DeviceSet) deviceStatus(devName string) (sizeInSectors, mappedSectors, highestMappedSector uint64, err error) {
+	var params string
+	_, sizeInSectors, _, params, err = getStatus(devName)
+	if err != nil {
+		return
+	}
+	if _, err = fmt.Sscanf(params, "%d %d", &mappedSectors, &highestMappedSector); err == nil {
+		return
+	}
+	return
+}
+
+func (devices *DeviceSet) GetDeviceStatus(hash string) (*DevStatus, error) {
+	devices.Lock()
+	defer devices.Unlock()
+
+	info := devices.Devices[hash]
+	if info == nil {
+		return nil, fmt.Errorf("No device %s", hash)
+	}
+
+	status := &DevStatus{
+		DeviceId:      info.DeviceId,
+		Size:          info.Size,
+		TransactionId: info.TransactionId,
+	}
+
+	if err := devices.activateDeviceIfNeeded(hash); err != nil {
+		return nil, fmt.Errorf("Error activating devmapper device for '%s': %s", hash, err)
+	}
+
+	if sizeInSectors, mappedSectors, highestMappedSector, err := devices.deviceStatus(info.DevName()); err != nil {
+		return nil, err
+	} else {
+		status.SizeInSectors = sizeInSectors
+		status.MappedSectors = mappedSectors
+		status.HighestMappedSector = highestMappedSector
+	}
+
+	return status, nil
+}
+
+func (devices *DeviceSet) poolStatus() (totalSizeInSectors, transactionId, dataUsed, dataTotal, metadataUsed, metadataTotal uint64, err error) {
+	var params string
+	if _, totalSizeInSectors, _, params, err = getStatus(devices.getPoolName()); err == nil {
+		_, err = fmt.Sscanf(params, "%d %d/%d %d/%d", &transactionId, &metadataUsed, &metadataTotal, &dataUsed, &dataTotal)
+	}
+	return
+}
+
 func (devices *DeviceSet) Status() *Status {
 	devices.Lock()
 	defer devices.Unlock()
@@ -767,26 +853,25 @@ func (devices *DeviceSet) Status() *Status {
 	status.DataLoopback = path.Join(devices.loopbackDir(), "data")
 	status.MetadataLoopback = path.Join(devices.loopbackDir(), "metadata")
 
-	_, totalSizeInSectors, _, params, err := getStatus(devices.getPoolName())
+	totalSizeInSectors, _, dataUsed, dataTotal, metadataUsed, metadataTotal, err := devices.poolStatus()
 	if err == nil {
-		var transactionId, dataUsed, dataTotal, metadataUsed, metadataTotal uint64
-		if _, err := fmt.Sscanf(params, "%d %d/%d %d/%d", &transactionId, &metadataUsed, &metadataTotal, &dataUsed, &dataTotal); err == nil {
-			// Convert from blocks to bytes
-			blockSizeInSectors := totalSizeInSectors / dataTotal
+		// Convert from blocks to bytes
+		blockSizeInSectors := totalSizeInSectors / dataTotal
 
-			status.Data.Used = dataUsed * blockSizeInSectors * 512
-			status.Data.Total = dataTotal * blockSizeInSectors * 512
+		status.Data.Used = dataUsed * blockSizeInSectors * 512
+		status.Data.Total = dataTotal * blockSizeInSectors * 512
 
-			// metadata blocks are always 4k
-			status.Metadata.Used = metadataUsed * 4096
-			status.Metadata.Total = metadataTotal * 4096
-		}
+		// metadata blocks are always 4k
+		status.Metadata.Used = metadataUsed * 4096
+		status.Metadata.Total = metadataTotal * 4096
+
+		status.SectorSize = blockSizeInSectors * 512
 	}
 
 	return status
 }
 
-func NewDeviceSet(root string) (*DeviceSet, error) {
+func NewDeviceSet(root string, doInit bool) (*DeviceSet, error) {
 	SetDevDir("/dev")
 
 	devices := &DeviceSet{
@@ -795,7 +880,7 @@ func NewDeviceSet(root string) (*DeviceSet, error) {
 		activeMounts: make(map[string]int),
 	}
 
-	if err := devices.initDevmapper(); err != nil {
+	if err := devices.initDevmapper(doInit); err != nil {
 		return nil, err
 	}
 

graphdriver/devmapper/docker-device-tool/device_tool.go

@@ -1,59 +1,112 @@
 package main
 
 import (
+	"flag"
 	"fmt"
-	"github.com/dotcloud/docker/devmapper"
+	"github.com/dotcloud/docker/graphdriver/devmapper"
 	"os"
+	"path"
+	"sort"
 )
 
 func usage() {
-	fmt.Printf("Usage: %s [snap new-id base-id] | [remove id] | [mount id mountpoint]\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "Usage: %s <flags>  [status] | [list] | [device id] | [snap new-id base-id] | [remove id] | [mount id mountpoint]\n", os.Args[0])
+	flag.PrintDefaults()
 	os.Exit(1)
 }
 
 func main() {
-	devices := devmapper.NewDeviceSet("/var/lib/docker")
+	root := flag.String("r", "/var/lib/docker", "Docker root dir")
+	flDebug := flag.Bool("D", false, "Debug mode")
 
-	if len(os.Args) < 2 {
+	flag.Parse()
+
+	if *flDebug {
+		os.Setenv("DEBUG", "1")
+	}
+
+	if flag.NArg() < 1 {
 		usage()
 	}
 
-	cmd := os.Args[1]
-	if cmd == "snap" {
-		if len(os.Args) < 4 {
+	args := flag.Args()
+
+	home := path.Join(*root, "devicemapper")
+	devices, err := devmapper.NewDeviceSet(home, false)
+	if err != nil {
+		fmt.Println("Can't initialize device mapper: ", err)
+		os.Exit(1)
+	}
+
+	switch args[0] {
+	case "status":
+		status := devices.Status()
+		fmt.Printf("Pool name: %s\n", status.PoolName)
+		fmt.Printf("Data Loopback file: %s\n", status.DataLoopback)
+		fmt.Printf("Metadata Loopback file: %s\n", status.MetadataLoopback)
+		fmt.Printf("Sector size: %d\n", status.SectorSize)
+		fmt.Printf("Data use: %d of %d (%.1f %%)\n", status.Data.Used, status.Data.Total, 100.0*float64(status.Data.Used)/float64(status.Data.Total))
+		fmt.Printf("Metadata use: %d of %d (%.1f %%)\n", status.Metadata.Used, status.Metadata.Total, 100.0*float64(status.Metadata.Used)/float64(status.Metadata.Total))
+		break
+	case "list":
+		ids := devices.List()
+		sort.Strings(ids)
+		for _, id := range ids {
+			fmt.Println(id)
+		}
+		break
+	case "device":
+		if flag.NArg() < 2 {
+			usage()
+		}
+		status, err := devices.GetDeviceStatus(args[1])
+		if err != nil {
+			fmt.Println("Can't get device info: ", err)
+			os.Exit(1)
+		}
+		fmt.Printf("Id: %d\n", status.DeviceId)
+		fmt.Printf("Size: %d\n", status.Size)
+		fmt.Printf("Transaction Id: %d\n", status.TransactionId)
+		fmt.Printf("Size in Sectors: %d\n", status.SizeInSectors)
+		fmt.Printf("Mapped Sectors: %d\n", status.MappedSectors)
+		fmt.Printf("Highest Mapped Sector: %d\n", status.HighestMappedSector)
+		break
+	case "snap":
+		if flag.NArg() < 3 {
 			usage()
 		}
 
-		err := devices.AddDevice(os.Args[2], os.Args[3])
+		err := devices.AddDevice(args[1], args[2])
 		if err != nil {
 			fmt.Println("Can't create snap device: ", err)
 			os.Exit(1)
 		}
-	} else if cmd == "remove" {
-		if len(os.Args) < 3 {
+		break
+	case "remove":
+		if flag.NArg() < 2 {
 			usage()
 		}
 
-		err := devices.RemoveDevice(os.Args[2])
+		err := devices.RemoveDevice(args[1])
 		if err != nil {
 			fmt.Println("Can't remove device: ", err)
 			os.Exit(1)
 		}
-	} else if cmd == "mount" {
-		if len(os.Args) < 4 {
+		break
+	case "mount":
+		if flag.NArg() < 3 {
 			usage()
 		}
 
-		err := devices.MountDevice(os.Args[2], os.Args[3])
+		err := devices.MountDevice(args[1], args[2], false)
 		if err != nil {
 			fmt.Println("Can't create snap device: ", err)
 			os.Exit(1)
 		}
-	} else {
-		fmt.Printf("Unknown command %s\n", cmd)
-		if len(os.Args) < 4 {
-			usage()
-		}
+		break
+	default:
+		fmt.Printf("Unknown command %s\n", args[0])
+		usage()
 
 		os.Exit(1)
 	}

graphdriver/devmapper/driver.go

@@ -22,7 +22,7 @@ type Driver struct {
 }
 
 func Init(home string) (graphdriver.Driver, error) {
-	deviceSet, err := NewDeviceSet(home)
+	deviceSet, err := NewDeviceSet(home, true)
 	if err != nil {
 		return nil, err
 	}