Add total and used field to device response

it will be user friendly if we have total,
free,used field in device response.

total size= total size of device.
free size= available size of device for
volume creation.
used size= space used for volume creation.

Signed-off-by: Madhu Rajanna <mrajanna@redhat.com>

Author: Madhu-1

plugins/device/api/resp.go

@@ -10,7 +10,9 @@ import (
 type Info struct {
 	Device        string    `json:"device"`
 	State         string    `json:"state"`
-	AvailableSize uint64    `json:"available-size"`
+	AvailableSize uint64    `json:"free-size"`
+	TotalSize     uint64    `json:"total-size"`
+	UsedSize      uint64    `json:"used-size"`
 	ExtentSize    uint64    `json:"extent-size"`
 	Used          bool      `json:"device-used"`
 	PeerID        uuid.UUID `json:"peer-id"`

plugins/device/deviceutils/store-utils.go

@@ -109,6 +109,7 @@ func UpdateDeviceFreeSize(peerID, device string) error {
 		return err
 	}
 	dev.AvailableSize = availableSize
+	dev.UsedSize = dev.TotalSize - availableSize
 	dev.ExtentSize = extentSize
 	return AddOrUpdateDevice(*dev)
 }
@@ -127,6 +128,7 @@ func UpdateDeviceFreeSizeByVg(peerID, vgname string) error {
 				return err
 			}
 			dev.AvailableSize = availableSize
+			dev.UsedSize = dev.TotalSize - availableSize
 			dev.ExtentSize = extentSize
 			return AddOrUpdateDevice(dev)
 		}

plugins/device/transaction.go

@@ -48,6 +48,8 @@ func txnPrepareDevice(c transaction.TxnCtx) error {
 		Device:        device,
 		State:         deviceapi.DeviceEnabled,
 		AvailableSize: availableSize,
+		TotalSize:     availableSize,
+		UsedSize:      0,
 		ExtentSize:    extentSize,
 		PeerID:        peerID,
 	}