Add FS option support

Author: ashald

README.md

@@ -9,9 +9,22 @@ chown -1:-1
 
 ```
 
+### Sparse
+
+|FS   | Sparse        | Regular    |
+| --- | ------------- | ---------- |
+|xfs  | 0%/1%         | 100%/100%  |
+|ext4 | 0%/3%         | 100%/3%    |
+
+
 ## Development
 Go 1.11
 ```bash
 go mod vendor
 go mod tidy
-```
+```
+
+## Test
+ext4/xfs - sparse/regular
+on ext4/xfs vs ext3
+not enough space

driver/driver.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -90,6 +91,17 @@ func (d Driver) Create(req *v.CreateRequest) error {
 		}
 	}
 
+	var fs string
+	fsInput, fsPresent := req.Options["fs"]
+	if fsPresent && len(fsInput) > 0 {
+		fs = strings.ToLower(strings.TrimSpace(fsInput))
+	} else {
+		fs = "xfs"
+		logger.Debug().
+			Str("default", fs).
+			Msg("no fs opt found, using default")
+	}
+
 	uid := -1
 	uidStr, uidPresent := req.Options["uid"]
 	if uidPresent && len(uidStr) > 0 {
@@ -151,7 +163,7 @@ func (d Driver) Create(req *v.CreateRequest) error {
 
 	logger.Debug().Msg("starting creation")
 
-	err = d.manager.Create(req.Name, sizeInBytes, sparse, uid, gid, mode)
+	err = d.manager.Create(req.Name, sizeInBytes, sparse, fs, uid, gid, mode)
 	if err != nil {
 		return err
 	}
@@ -214,8 +226,9 @@ func (d Driver) Get(req *v.GetRequest) (*v.GetResponse, error) {
 		CreatedAt:  fmt.Sprintf(vol.CreatedAt.Format(time.RFC3339)),
 		Mountpoint: vol.MountPointPath,
 		Status: map[string]interface{}{
-			"size-max":     strconv.FormatUint(vol.MaxSizeInBytes, 10),
-			"size-current": strconv.FormatUint(vol.CurrentSizeInBytes, 10),
+			"fs":             vol.Fs,
+			"size-max":       strconv.FormatUint(vol.MaxSizeInBytes, 10),
+			"size-allocated": strconv.FormatUint(vol.AllocatedSizeInBytes, 10),
 		},
 	}
 

main.go

@@ -29,7 +29,7 @@ var (
 		StateDir:    "/run/docker-volume-loopback",
 		DataDir:     "/var/lib/docker-volume-loopback",
 		MountDir:    "/mnt",
-		DefaultSize: "1G",
+		DefaultSize: "1GiB",
 		Debug:       false,
 	}
 )

manager/manager.go

@@ -29,47 +29,6 @@ type Config struct {
 	MountDir string
 }
 
-func (m Manager) getVolume(name string) (vol Volume, err error) {
-	volumeDataFilePath := filepath.Join(m.dataDir, name)
-
-	volumeDataFileInfo, err := os.Stat(volumeDataFilePath)
-
-	if err != nil {
-		if os.IsNotExist(err) {
-			err = errors.Errorf("Volume '%s' does not exist", name)
-		}
-		return
-	}
-
-	if !volumeDataFileInfo.Mode().IsRegular() {
-		err = errors.Errorf(
-			"Volume data path expected to point toa file but it appears to be something else: '%s'",
-			volumeDataFilePath)
-		return
-	}
-
-	details, ok := volumeDataFileInfo.Sys().(*syscall.Stat_t)
-	if !ok {
-		err = errors.Errorf(
-			"An issue occurred while retrieving details about volume '%s' - cannot stat '%s'",
-			name, volumeDataFilePath)
-	}
-
-	mountPointPath := filepath.Join(m.mountDir, name)
-
-	vol = Volume{
-		Name:               name,
-		CurrentSizeInBytes: uint64(details.Blocks * 512),
-		MaxSizeInBytes:     uint64(details.Size),
-		StateDir:           filepath.Join(m.stateDir, name),
-		DataFilePath:       volumeDataFilePath,
-		MountPointPath:     mountPointPath,
-		CreatedAt:          volumeDataFileInfo.ModTime(),
-	}
-
-	return
-}
-
 func New(cfg Config) (manager Manager, err error) {
 	// state dir
 	if cfg.StateDir == "" {
@@ -127,7 +86,8 @@ func (m Manager) List() ([]Volume, error) {
 
 	for _, file := range files {
 		if file.Mode().IsRegular() {
-			vol, err := m.getVolume(file.Name())
+			name := strings.TrimSuffix(file.Name(), filepath.Ext(file.Name()))
+			vol, err := m.getVolume(name)
 			if err != nil {
 				return nil, err
 			}
@@ -151,7 +111,7 @@ func (m Manager) Get(name string) (vol Volume, err error) {
 	return
 }
 
-func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid int, mode uint32) error {
+func (m Manager) Create(name string, sizeInBytes int64, sparse bool, fs string, uid, gid int, mode uint32) error {
 	err := validateName(name)
 	if err != nil {
 		return errors.Wrapf(err,
@@ -165,15 +125,27 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			name, sizeInBytes)
 	}
 
+	// We perform fs validation and construct mkfs flags array on the way
+	var mkfsFlags []string
+	if fs == "xfs" {
+		mkfsFlags = []string{}
+	} else if fs == "ext4" {
+		mkfsFlags = []string{"-F"}
+	} else {
+		return errors.Errorf(
+			"Error creating volume '%s' - only xfs and ext4 filesystems are supported, '%s' requested",
+			name, fs)
+	}
+
 	err = os.MkdirAll(m.dataDir, 0755)
 	if err != nil {
 		return errors.Wrapf(err,
-			"Error creating volume '%s' - data dir does not exist: '%s'",
+			"Error creating volume '%s' - cannot create data dir: '%s'",
 			name, m.dataDir)
 	}
 
 	// create data file
-	dataFilePath := filepath.Join(m.dataDir, name)
+	dataFilePath := filepath.Join(m.dataDir, name+"."+fs)
 	dataFileInfo, err := os.Create(dataFilePath)
 	if err != nil {
 		_ = os.Remove(dataFilePath) // attempt to cleanup
@@ -207,7 +179,7 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			}
 
 			// Here we assume that FS is unsupported and will fall back to 'dd' which is slow but should work everywhere
-			of := fmt.Sprintf("of=%s", dataFilePath)
+			of := "of=" + dataFilePath
 			bs := int64(1000000)
 			count := sizeInBytes / bs // we lose some precision here but it's likely to be negligible
 			errBytes, err = exec.Command(
@@ -226,12 +198,12 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 	}
 
 	// format data file
-	_, err = exec.Command("mkfs.ext4", "-F", dataFilePath).Output()
+	_, err = exec.Command(fmt.Sprintf("mkfs.%s", fs), append(mkfsFlags, dataFilePath)...).Output()
 	if err != nil {
 		_ = os.Remove(dataFilePath) // attempt to cleanup
 		return errors.Wrapf(err,
-			"Error creating volume '%s' - cannot format datafile as ext4 filesystem",
-			name, sizeInBytes)
+			"Error creating volume '%s' - cannot format datafile as %s filesystem",
+			name, fs)
 	}
 
 	// At this point we're done - last step is to adjust ownership if required.
@@ -243,7 +215,7 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			_ = os.Remove(dataFilePath) // attempt to cleanup
 			return errors.Wrapf(err,
 				"Error creating volume '%s' - cannot mount volume to adjust its root owner/permissions",
-				name, sizeInBytes)
+				name)
 		}
 
 		if mode > 0 {
@@ -253,7 +225,7 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 				_ = os.Remove(dataFilePath) // attempt to cleanup
 				return errors.Wrapf(err,
 					"Error creating volume '%s' - cannot adjust volume root permissions",
-					name, sizeInBytes)
+					name)
 			}
 		}
 		err = os.Chown(mountPath, uid, gid)
@@ -262,15 +234,15 @@ func (m Manager) Create(name string, sizeInBytes int64, sparse bool, uid, gid in
 			_ = os.Remove(dataFilePath) // attempt to cleanup
 			return errors.Wrapf(err,
 				"Error creating volume '%s' - cannot adjust volume root owner",
-				name, sizeInBytes)
+				name)
 		}
 
 		err = m.UnMount(name, lease)
 		if err != nil {
 			_ = os.Remove(dataFilePath) // attempt to cleanup
 			return errors.Wrapf(err,
 				"Error creating volume '%s' - cannot unmount volume after adjusting its root owner/permissions",
-				name, sizeInBytes)
+				name)
 		}
 	}
 
@@ -450,3 +422,61 @@ func validateName(name string) error {
 	}
 	return nil
 }
+
+func (m Manager) getVolume(name string) (vol Volume, err error) {
+	prefix := filepath.Join(m.dataDir, name) + ".*"
+	matches, err := filepath.Glob(prefix)
+	if err != nil {
+		err = errors.Wrapf(err,
+			"An issue occurred while retrieving details about volume '%s' - cannot glob data dir", name)
+		return
+	}
+	if len(matches) > 1 {
+		err = errors.Errorf("More than 1 data file found for volume '%s'", name)
+		return
+	} else if len(matches) == 0 {
+		err = errors.Errorf("Volume '%s' does not exist", name)
+		return
+	}
+
+	volumeDataFilePath := matches[0]
+	fs := strings.TrimLeft(filepath.Ext(volumeDataFilePath), ".")
+
+	volumeDataFileInfo, err := os.Stat(volumeDataFilePath)
+
+	if err != nil {
+		if os.IsNotExist(err) { // this should not happen but...
+			err = errors.Errorf("Volume '%s' disappeared just a moment ago", name)
+		}
+		return
+	}
+
+	if !volumeDataFileInfo.Mode().IsRegular() {
+		err = errors.Errorf(
+			"Volume data path expected to point to a file but it appears to be something else: '%s'",
+			volumeDataFilePath)
+		return
+	}
+
+	details, ok := volumeDataFileInfo.Sys().(*syscall.Stat_t)
+	if !ok {
+		err = errors.Errorf(
+			"An issue occurred while retrieving details about volume '%s' - cannot stat '%s'",
+			name, volumeDataFilePath)
+	}
+
+	mountPointPath := filepath.Join(m.mountDir, name)
+
+	vol = Volume{
+		Name:                 name,
+		Fs:                   fs,
+		AllocatedSizeInBytes: uint64(details.Blocks * 512),
+		MaxSizeInBytes:       uint64(details.Size),
+		StateDir:             filepath.Join(m.stateDir, name),
+		DataFilePath:         volumeDataFilePath,
+		MountPointPath:       mountPointPath,
+		CreatedAt:            volumeDataFileInfo.ModTime(),
+	}
+
+	return
+}

manager/volume.go

@@ -8,13 +8,14 @@ import (
 )
 
 type Volume struct {
-	Name               string
-	CurrentSizeInBytes uint64
-	MaxSizeInBytes     uint64
-	StateDir           string
-	DataFilePath       string
-	MountPointPath     string
-	CreatedAt          time.Time
+	Name                 string
+	AllocatedSizeInBytes uint64
+	Fs                   string
+	MaxSizeInBytes       uint64
+	StateDir             string
+	DataFilePath         string
+	MountPointPath       string
+	CreatedAt            time.Time
 }
 
 func (v Volume) IsMounted() (mounted bool, err error) {

plugin/config.json

@@ -27,7 +27,7 @@
             "Description": "Default size to apply to volumes when no value is specified",
             "Name": "DEFAULT_SIZE",
             "Settable": ["value"],
-            "Value": "1G"
+            "Value": "1GiB"
         }
     ],
     "Interface": {