feat: support full backup

ref: longhorn/longhorn 7070

Signed-off-by: Jack Lin <jack.lin@suse.com>

deltablock.go

@@ -175,7 +175,7 @@ func CreateDeltaBlockBackup(backupName string, config *DeltaBackupConfig) (isInc
 	}
 
 	backupRequest := &backupRequest{}
-	if volume.LastBackupName != "" {
+	if volume.LastBackupName != "" && !isFullBackup(config) {
 		lastBackupName := volume.LastBackupName
 		var backup, err = loadBackup(bsDriver, lastBackupName, volume.Name)
 		if err != nil {
@@ -208,6 +208,9 @@ func CreateDeltaBlockBackup(backupName string, config *DeltaBackupConfig) (isInc
 		}
 	}
 
+	logrus.Infof("[DEBUG] isFullBackup(config): %v", isFullBackup(config))
+	logrus.Infof("[DEBUG] backupRequest.lastBackup: %v", backupRequest.lastBackup)
+
 	log.WithFields(logrus.Fields{
 		LogFieldReason:       LogReasonStart,
 		LogFieldObject:       LogObjectSnapshot,
@@ -368,7 +371,7 @@ func backupBlock(bsDriver BackupStoreDriver, config *DeltaBackupConfig,
 	}()
 
 	blkFile := getBlockFilePath(volume.Name, checksum)
-	if bsDriver.FileExists(blkFile) {
+	if bsDriver.FileExists(blkFile) && !isFullBackup(config) {
 		log.Debugf("Found existing block matching at %v", blkFile)
 		return nil
 	}
@@ -1303,3 +1306,12 @@ func getBlockNamesForVolume(driver BackupStoreDriver, volumeName string) ([]stri
 
 	return util.ExtractNames(names, "", BLK_SUFFIX), nil
 }
+
+func isFullBackup(config *DeltaBackupConfig) bool {
+	if config.Labels != nil {
+		if backupMode, exist := config.Labels[types.GetLonghornLabelKey(types.LonghornBackupOptionBackupMode)]; exist {
+			return backupMode == types.LonghornBackupModeFull
+		}
+	}
+	return false
+}

types/types.go

@@ -1,5 +1,7 @@
 package types
 
+import "fmt"
+
 type ProgressState string
 
 const (
@@ -29,6 +31,12 @@ const (
 	NOProxy    = "NO_PROXY"
 
 	VirtualHostedStyle = "VIRTUAL_HOSTED_STYLE"
+
+	LonghornLabelKeyPrefix = "longhorn.io"
+
+	LonghornBackupOptionBackupMode = "backup-mode"
+	LonghornBackupModeFull         = "full"
+	LonghornBackupModeIncremental  = "incremental"
 )
 
 type Mapping struct {
@@ -65,3 +73,7 @@ const (
 const (
 	ErrorMsgRestoreCancelled = "backup restoration is cancelled"
 )
+
+func GetLonghornLabelKey(name string) string {
+	return fmt.Sprintf("%s/%s", LonghornLabelKeyPrefix, name)
+}