actions/image-partition: truncate filesystem label to maximum supported length

actions/image_partition_action.go

@@ -43,6 +43,7 @@ Yaml syntax for partitions:
      - name: partition name
 	   partlabel: partition label
 	   fs: filesystem
+	   fslabel: filesystem label
 	   start: offset
 	   end: offset
 	   features: list of filesystem features
@@ -72,6 +73,12 @@ Optional properties:
 - partlabel -- label for the partition in the GPT partition table. Defaults
 to the `name` property of the partition. May only be used for GPT partitions.
 
+- fslabel -- (optional) Sets the volume name (label) of the filesystem. Defaults
+to the `name` property of the partition. The filesystem label can be up to 11
+characters long for vfat, 16 characters long for ext2/3/4, 255 characters long
+for btrfs, 512 characters long for hfs/hfsplus and 12 characters long for xfs.
+Any longer labels will be automatically truncated.
+
 - parttype -- set the partition type in the partition table. The string should
 be in a hexadecimal format (2-characters) for msdos partition tables and GUID format
 (36-characters) for GPT partition tables. For instance, "82" for msdos sets the
@@ -168,6 +175,7 @@ type Partition struct {
 	number    int
 	Name      string
 	PartLabel string
+	FSLabel   string
 	PartType  string
 	Start     string
 	End       string
@@ -305,37 +313,37 @@ func (i ImagePartitionAction) formatPartition(p *Partition, context debos.DebosC
 	cmdline := []string{}
 	switch p.FS {
 	case "vfat":
-		cmdline = append(cmdline, "mkfs.vfat", "-F32", "-n", p.Name)
+		cmdline = append(cmdline, "mkfs.vfat", "-F32", "-n", p.FSLabel)
 	case "btrfs":
 		// Force formatting to prevent failure in case if partition was formatted already
-		cmdline = append(cmdline, "mkfs.btrfs", "-L", p.Name, "-f")
+		cmdline = append(cmdline, "mkfs.btrfs", "-L", p.FSLabel, "-f")
 		if len(p.Features) > 0 {
 			cmdline = append(cmdline, "-O", strings.Join(p.Features, ","))
 		}
 		if len(p.FSUUID) > 0 {
 			cmdline = append(cmdline, "-U", p.FSUUID)
 		}
 	case "f2fs":
-		cmdline = append(cmdline, "mkfs.f2fs", "-l", p.Name)
+		cmdline = append(cmdline, "mkfs.f2fs", "-l", p.FSLabel)
 		if len(p.Features) > 0 {
 			cmdline = append(cmdline, "-O", strings.Join(p.Features, ","))
 		}
 	case "hfs":
-		cmdline = append(cmdline, "mkfs.hfs", "-h", "-v", p.Name)
+		cmdline = append(cmdline, "mkfs.hfs", "-h", "-v", p.FSLabel)
 	case "hfsplus":
-		cmdline = append(cmdline, "mkfs.hfsplus", "-v", p.Name)
+		cmdline = append(cmdline, "mkfs.hfsplus", "-v", p.FSLabel)
 	case "hfsx":
-		cmdline = append(cmdline, "mkfs.hfsplus", "-s", "-v", p.Name)
+		cmdline = append(cmdline, "mkfs.hfsplus", "-s", "-v", p.FSLabel)
 		// hfsx is case-insensitive hfs+, should be treated as "normal" hfs+ from now on
 		p.FS = "hfsplus"
 	case "xfs":
-		cmdline = append(cmdline, "mkfs.xfs", "-L", p.Name)
+		cmdline = append(cmdline, "mkfs.xfs", "-L", p.FSLabel)
 		if len(p.FSUUID) > 0 {
 			cmdline = append(cmdline, "-m", "uuid="+p.FSUUID)
 		}
 	case "none":
 	default:
-		cmdline = append(cmdline, fmt.Sprintf("mkfs.%s", p.FS), "-L", p.Name)
+		cmdline = append(cmdline, fmt.Sprintf("mkfs.%s", p.FS), "-L", p.FSLabel)
 		if len(p.Features) > 0 {
 			cmdline = append(cmdline, "-O", strings.Join(p.Features, ","))
 		}
@@ -599,6 +607,7 @@ func (i *ImagePartitionAction) Verify(context *debos.DebosContext) error {
 
 	num := 1
 	for idx, _ := range i.Partitions {
+		var maxLength int = 0
 		p := &i.Partitions[idx]
 		p.number = num
 		num++
@@ -654,6 +663,31 @@ func (i *ImagePartitionAction) Verify(context *debos.DebosContext) error {
 		case "":
 			return fmt.Errorf("Partition %s missing fs type", p.Name)
 		}
+
+		if p.FSLabel == "" {
+			p.FSLabel = p.Name
+		}
+
+		switch p.FS {
+			case "vfat":
+				maxLength = 11
+			case "ext2", "ext3", "ext4":
+				maxLength = 16
+			case "btrfs":
+				maxLength = 255
+			case "f2fs":
+				maxLength = 512
+			case "hfs", "hfsplus":
+				maxLength = 255
+			case "xfs":
+				maxLength = 12
+		}
+
+		if maxLength > 0 && len(p.FSLabel) > maxLength {
+			truncated := p.FSLabel[0:maxLength]
+			log.Printf("Warning: fs label for %s '%s' is too long; truncated to '%s'", p.Name, p.FSLabel, truncated)
+			p.FSLabel = truncated
+		}
 	}
 
 	for idx, _ := range i.Mountpoints {