mount: add --devname to set the device name sent to FUSE for mount display

Before this change, the device name was always the remote:path rclone
was configured with. However this can contain sensitive information
and it appears in the `mount` output, so `--devname` allows the user
to configure it.

See: https://forum.rclone.org/t/rclone-mount-blomp-problem/29151/11

cmd/cmount/mount.go

@@ -168,7 +168,7 @@ func mount(VFS *vfs.VFS, mountPath string, opt *mountlib.Options) (<-chan error,
 	host.SetCapCaseInsensitive(f.Features().CaseInsensitive)
 
 	// Create options
-	options := mountOptions(VFS, f.Name()+":"+f.Root(), mountpoint, opt)
+	options := mountOptions(VFS, opt.DeviceName, mountpoint, opt)
 	fs.Debugf(f, "Mounting with options: %q", options)
 
 	// Serve the mount point in the background returning error to errChan

cmd/mount/mount.go

@@ -86,7 +86,7 @@ func mount(VFS *vfs.VFS, mountpoint string, opt *mountlib.Options) (<-chan error
 
 	f := VFS.Fs()
 	fs.Debugf(f, "Mounting on %q", mountpoint)
-	c, err := fuse.Mount(mountpoint, mountOptions(VFS, f.Name()+":"+f.Root(), opt)...)
+	c, err := fuse.Mount(mountpoint, mountOptions(VFS, opt.DeviceName, opt)...)
 	if err != nil {
 		return nil, nil, err
 	}

cmd/mount2/mount.go

@@ -25,11 +25,10 @@ func init() {
 // mountOptions configures the options from the command line flags
 //
 // man mount.fuse for more info and note the -o flag for other options
-func mountOptions(fsys *FS, f fs.Fs) (mountOpts *fuse.MountOptions) {
-	device := f.Name() + ":" + f.Root()
+func mountOptions(fsys *FS, f fs.Fs, opt *mountlib.Options) (mountOpts *fuse.MountOptions) {
 	mountOpts = &fuse.MountOptions{
 		AllowOther:    fsys.opt.AllowOther,
-		FsName:        device,
+		FsName:        opt.DeviceName,
 		Name:          "rclone",
 		DisableXAttrs: true,
 		Debug:         fsys.opt.DebugFUSE,
@@ -120,7 +119,7 @@ func mountOptions(fsys *FS, f fs.Fs) (mountOpts *fuse.MountOptions) {
 	if runtime.GOOS == "darwin" {
 		opts = append(opts,
 			// VolumeName sets the volume name shown in Finder.
-			fmt.Sprintf("volname=%s", device),
+			fmt.Sprintf("volname=%s", opt.VolumeName),
 
 			// NoAppleXattr makes OSXFUSE disallow extended attributes with the
 			// prefix "com.apple.". This disables persistent Finder state and
@@ -167,7 +166,7 @@ func mount(VFS *vfs.VFS, mountpoint string, opt *mountlib.Options) (<-chan error
 	//mOpts.Debug = mountlib.DebugFUSE
 
 	//conn := fusefs.NewFileSystemConnector(nodeFs.Root(), mOpts)
-	mountOpts := mountOptions(fsys, f)
+	mountOpts := mountOptions(fsys, f, opt)
 
 	// FIXME fill out
 	opts := fusefs.Options{

cmd/mountlib/mount.go

@@ -40,6 +40,7 @@ type Options struct {
 	ExtraOptions       []string
 	ExtraFlags         []string
 	AttrTimeout        time.Duration // how long the kernel caches attribute for
+	DeviceName         string
 	VolumeName         string
 	NoAppleDouble      bool
 	NoAppleXattr       bool
@@ -125,6 +126,7 @@ func AddFlags(flagSet *pflag.FlagSet) {
 	flags.BoolVarP(flagSet, &Opt.AsyncRead, "async-read", "", Opt.AsyncRead, "Use asynchronous reads (not supported on Windows)")
 	flags.FVarP(flagSet, &Opt.MaxReadAhead, "max-read-ahead", "", "The number of bytes that can be prefetched for sequential reads (not supported on Windows)")
 	flags.BoolVarP(flagSet, &Opt.WritebackCache, "write-back-cache", "", Opt.WritebackCache, "Makes kernel buffer writes before sending them to rclone (without this, writethrough caching is used) (not supported on Windows)")
+	flags.StringVarP(flagSet, &Opt.DeviceName, "devname", "", Opt.DeviceName, "Set the device name - default is remote:path")
 	// Windows and OSX
 	flags.StringVarP(flagSet, &Opt.VolumeName, "volname", "", Opt.VolumeName, "Set the volume name (supported on Windows and OSX only)")
 	// OSX only
@@ -235,6 +237,7 @@ func (m *MountPoint) Mount() (daemon *os.Process, err error) {
 		return nil, err
 	}
 	m.SetVolumeName(m.MountOpt.VolumeName)
+	m.SetDeviceName(m.MountOpt.DeviceName)
 
 	// Start background task if --daemon is specified
 	if m.MountOpt.Daemon {

cmd/mountlib/utils.go

@@ -87,7 +87,7 @@ func (m *MountPoint) CheckAllowings() error {
 // SetVolumeName with sensible default
 func (m *MountPoint) SetVolumeName(vol string) {
 	if vol == "" {
-		vol = m.Fs.Name() + ":" + m.Fs.Root()
+		vol = fs.ConfigString(m.Fs)
 	}
 	m.MountOpt.SetVolumeName(vol)
 }
@@ -102,3 +102,11 @@ func (o *Options) SetVolumeName(vol string) {
 	}
 	o.VolumeName = vol
 }
+
+// SetDeviceName with sensible default
+func (m *MountPoint) SetDeviceName(dev string) {
+	if dev == "" {
+		dev = fs.ConfigString(m.Fs)
+	}
+	m.MountOpt.DeviceName = dev
+}