Added FUSE support (#55)

This exposes the watches' file system over FUSE. This way, we can access files on the watch without having to go through `itctl` or developing 3rd party tools.

**Features**

- [x] read/write access to the file system
- [x] read access to momentary sensor data
- [x] live access to sensor data (i.e. WatchMotion rather than Motion)
- [x] configuration of mount point

Co-authored-by: Yannick Ulrich <yannick.ulrich@durham.ac.uk>
Reviewed-on: https://gitea.arsenm.dev/Arsen6331/itd/pulls/55
Co-authored-by: yannickulrich <yannick.ulrich@protonmail.com>
Co-committed-by: yannickulrich <yannick.ulrich@protonmail.com>

config.go

@@ -106,5 +106,8 @@ func setCfgDefaults() {
 		"notifs.ignore.body":    []string{},
 
 		"music.vol.interval": 5,
+
+		"fuse.enabled": false,
+		"fuse.mountpoint": "/tmp/itd/mnt",
 	}, "."), nil)
 }

fuse.go

@@ -0,0 +1,60 @@
+package main
+import (
+	"go.arsenm.dev/itd/internal/fusefs"
+	"os"
+	"github.com/hanwen/go-fuse/v2/fs"
+	"github.com/hanwen/go-fuse/v2/fuse"
+	"go.arsenm.dev/logger/log"
+	"context"
+	"go.arsenm.dev/infinitime"
+)
+
+func startFUSE(ctx context.Context, dev *infinitime.Device) error {
+	// This is where we'll mount the FS
+	err := os.MkdirAll(k.String("fuse.mountpoint"), 0755)
+	if err != nil && !os.IsExist(err) {
+		return err
+	}
+
+	// Ignore the error because nothing might be mounted on the mountpoint
+	_ = fusefs.Unmount(k.String("fuse.mountpoint"))
+
+
+	root, err := fusefs.BuildRootNode(dev)
+	if err != nil {
+		log.Error("Building root node failed").
+			Err(err).
+			Send()
+		return err
+	}
+
+	server, err := fs.Mount(k.String("fuse.mountpoint"), root, &fs.Options{
+		MountOptions: fuse.MountOptions{
+			// Set to true to see how the file system works.
+			Debug: false,
+			SingleThreaded: true,
+		},
+	})
+	if err != nil {
+		log.Error("Mounting failed").
+			Str("target", k.String("fuse.mountpoint")).
+			Err(err).
+			Send()
+			return err
+	}
+
+	log.Info("Mounted on target").
+		Str("target", k.String("fuse.mountpoint")).
+		Send()
+
+	fusefs.BuildProperties(dev)
+
+	if err != nil {
+		log.Warn("Error getting BLE filesystem").Err(err).Send()
+		return err
+	}
+
+	// Wait until unmount before exiting
+	go server.Serve()
+	return nil
+}

go.mod

@@ -45,6 +45,7 @@ require (
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/gookit/color v1.5.1 // indirect
 	github.com/gopherjs/gopherjs v1.17.2 // indirect
+	github.com/hanwen/go-fuse/v2 v2.2.0 // indirect
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/jsummers/gobmp v0.0.0-20151104160322-e2ba15ffa76e // indirect
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 // indirect

go.sum

@@ -257,6 +257,8 @@ github.com/goxjs/gl v0.0.0-20210104184919-e3fafc6f8f2a/go.mod h1:dy/f2gjY09hwVfI
 github.com/goxjs/glfw v0.0.0-20191126052801-d2efb5f20838/go.mod h1:oS8P8gVOT4ywTcjV6wZlOU4GuVFQ8F5328KY3MJ79CY=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
+github.com/hanwen/go-fuse/v2 v2.2.0 h1:jo5QZYmBLNcl9ovypWaQ5yXMSSV+Ch68xoC3rtZvvBM=
+github.com/hanwen/go-fuse/v2 v2.2.0/go.mod h1:B1nGE/6RBFyBRC1RRnf23UpwCdyJ31eukw34oAKukAc=
 github.com/hashicorp/consul/api v1.1.0/go.mod h1:VmuI/Lkw1nC05EYQWNKwWGbkg+FbDBtguAZLlVdkD9Q=
 github.com/hashicorp/consul/api v1.13.0/go.mod h1:ZlVrynguJKcYr54zGaDbaL3fOvKC9m72FhPvA8T35KQ=
 github.com/hashicorp/consul/sdk v0.1.1/go.mod h1:VKf9jXwCTEY1QZP2MOLRhb5i/I/ssyNV1vwHyQBF0x8=

internal/fusefs/fuse.go

@@ -0,0 +1,572 @@
+package fusefs
+
+import (
+	"go.arsenm.dev/infinitime"
+	"go.arsenm.dev/infinitime/blefs"
+	"go.arsenm.dev/logger/log"
+	"context"
+	"syscall"
+	"github.com/hanwen/go-fuse/v2/fs"
+	"github.com/hanwen/go-fuse/v2/fuse"
+	"io"
+	"bytes"
+	"strconv"
+)
+
+type ITProperty struct {
+	name string
+	Ino uint64
+	gen func() ([]byte, error)
+}
+
+
+type DirEntry struct {
+	isDir    bool
+	modtime  uint64
+	size     uint32
+	path     string
+}
+
+type ITNode struct {
+	fs.Inode
+	kind int
+	Ino uint64
+
+	lst []DirEntry
+	self DirEntry
+	path string
+}
+
+var myfs *blefs.FS = nil
+var inodemap map[string]uint64 = nil
+
+func BuildRootNode(dev *infinitime.Device) (*ITNode, error) {
+	var err error
+	inodemap = make(map[string]uint64)
+	myfs, err = dev.FS()
+	if err != nil {
+		log.Error("FUSE Failed to get filesystem").Err(err).Send()
+		return nil, err
+	}
+
+	return &ITNode{kind: 0}, nil
+}
+
+var properties = make([]ITProperty, 6)
+
+func BuildProperties(dev *infinitime.Device) {
+	properties[0] = ITProperty{"heartrate", 2,
+		func() ([]byte, error) {
+			ans, err := dev.HeartRate()
+			return []byte(strconv.Itoa(int(ans)) + "\n"), err
+	}}
+	properties[1] = ITProperty{"battery", 3,
+		func() ([]byte, error) {
+			ans, err := dev.BatteryLevel()
+			return []byte(strconv.Itoa(int(ans)) + "\n"), err
+	}}
+	properties[2] = ITProperty{"motion", 4,
+		func() ([]byte, error) {
+			ans, err := dev.Motion()
+			return []byte(strconv.Itoa(int(ans.X)) + " " + strconv.Itoa(int(ans.Y)) + " " + strconv.Itoa(int(ans.Z)) + "\n"), err
+	}}
+	properties[3] = ITProperty{"stepcount", 6,
+		func() ([]byte, error) {
+			ans, err := dev.StepCount()
+			return []byte(strconv.Itoa(int(ans)) + "\n"), err
+	}}
+	properties[4] = ITProperty{"version", 7,
+		func() ([]byte, error) {
+			ans, err := dev.Version()
+			return []byte(ans + "\n"), err
+	}}
+	properties[5] = ITProperty{"address", 8,
+		func() ([]byte, error) {
+			ans := dev.Address()
+			return []byte(ans + "\n"), nil
+	}}
+
+}
+
+
+var _ fs.NodeReaddirer = (*ITNode)(nil)
+
+// Readdir is part of the NodeReaddirer interface
+func (n *ITNode) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
+	switch n.kind {
+	case 0:
+		// root folder
+		r := make([]fuse.DirEntry, 2)
+		r[0] = fuse.DirEntry{
+			Name: "info",
+			Ino:  0,
+			Mode: fuse.S_IFDIR,
+		}
+		r[1] = fuse.DirEntry{
+			Name: "fs",
+			Ino:  1,
+			Mode: fuse.S_IFDIR,
+		}
+		return fs.NewListDirStream(r), 0
+
+	case 1:
+		// info folder
+		r := make([]fuse.DirEntry, 6)
+		for ind, value := range properties {
+			r[ind] = fuse.DirEntry{
+				Name: value.name,
+				Ino:  value.Ino,
+				Mode: fuse.S_IFREG,
+			}
+		}
+
+		return fs.NewListDirStream(r), 0
+
+	case 2:
+		// on info
+		files, err := myfs.ReadDir(n.path)
+		if err != nil {
+			log.Error("FUSE ReadDir failed").Str("path", n.path).Err(err).Send()
+			return nil, syscallErr(err)
+		}
+
+		log.Debug("FUSE ReadDir succeeded").Str("path", n.path).Int("objects", len(files)).Send()
+		r := make([]fuse.DirEntry, len(files))
+		n.lst = make([]DirEntry, len(files))
+		for ind, entry := range files {
+			info, err := entry.Info()
+			if err != nil {
+				log.Error("FUSE Info failed").Str("path", n.path).Err(err).Send()
+				return nil, syscallErr(err)
+			}
+			name := info.Name()
+
+			file := DirEntry{
+				path: n.path + "/" + name,
+				size: uint32(info.Size()),
+				modtime: uint64(info.ModTime().Unix()),
+				isDir: info.IsDir(),
+			}
+			n.lst[ind] = file
+
+			ino := inodemap[file.path]
+			if ino == 0 {
+				ino = uint64(len(inodemap)) + 1
+				inodemap[file.path] = ino
+			}
+
+			if file.isDir {
+				r[ind] = fuse.DirEntry{
+					Name: name,
+					Mode: fuse.S_IFDIR,
+					Ino : ino + 10,
+				}
+			} else {
+				r[ind] = fuse.DirEntry{
+					Name: name,
+					Mode: fuse.S_IFREG,
+					Ino : ino + 10,
+				}
+			}
+		}
+		return fs.NewListDirStream(r), 0
+	}
+	r := make([]fuse.DirEntry, 0)
+	return fs.NewListDirStream(r), 0
+}
+
+var _ fs.NodeLookuper = (*ITNode)(nil)
+func (n *ITNode) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
+	switch n.kind {
+	case 0:
+		// root folder
+		if name == "info" {
+			stable := fs.StableAttr{
+				Mode: fuse.S_IFDIR,
+				Ino: uint64(0),
+			}
+			operations := &ITNode{kind: 1, Ino: 0}
+			child := n.NewInode(ctx, operations, stable)
+			return child, 0
+		} else if name == "fs" {
+			stable := fs.StableAttr{
+				Mode: fuse.S_IFDIR,
+				Ino: uint64(1),
+			}
+			operations := &ITNode{kind: 2, Ino: 1, path : ""}
+			child := n.NewInode(ctx, operations, stable)
+			return child, 0
+		}
+	case 1:
+		// info folder
+		for _, value := range properties {
+			if value.name == name {
+				stable := fs.StableAttr{
+					Mode: fuse.S_IFREG,
+					Ino: uint64(value.Ino),
+				}
+				operations := &ITNode{kind: 3, Ino: value.Ino}
+				child := n.NewInode(ctx, operations, stable)
+				return child, 0
+			}
+		}
+
+	case 2:
+		// FS object
+		if len(n.lst) == 0 {
+			n.Readdir(ctx)
+		}
+
+		for _, file := range n.lst {
+			if file.path != n.path + "/" + name {
+				continue
+			}
+			log.Debug("FUSE Lookup successful").Str("path", file.path).Send()
+
+			if file.isDir {
+				stable := fs.StableAttr{
+					Mode: fuse.S_IFDIR,
+					Ino: inodemap[file.path],
+				}
+				operations := &ITNode{kind: 2, path: file.path}
+				child := n.NewInode(ctx, operations, stable)
+				return child, 0
+			} else {
+				stable := fs.StableAttr{
+					Mode: fuse.S_IFREG,
+					Ino: inodemap[file.path],
+				}
+				operations := &ITNode{
+					kind: 2, path: file.path,
+					self: file,
+				}
+				child := n.NewInode(ctx, operations, stable)
+				return child, 0
+			}
+			break
+		}
+		log.Warn("FUSE Lookup failed").Str("path", n.path + "/" + name).Send()
+	}
+	return nil, syscall.ENOENT
+}
+
+type bytesFileReadHandle struct {
+	content []byte
+}
+
+var _ fs.FileReader = (*bytesFileReadHandle)(nil)
+func (fh *bytesFileReadHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
+	log.Debug("FUSE Executing Read").Int("size", len(fh.content)).Send()
+	end := off + int64(len(dest))
+	if end > int64(len(fh.content)) {
+		end = int64(len(fh.content))
+	}
+	return fuse.ReadResultData(fh.content[off:end]), 0
+}
+
+type sensorFileReadHandle struct {
+	content []byte
+}
+var _ fs.FileReader = (*sensorFileReadHandle)(nil)
+func (fh *sensorFileReadHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
+	log.Info("Executing Read").Int("size", len(fh.content)).Send()
+	end := off + int64(len(dest))
+	if end > int64(len(fh.content)) {
+		end = int64(len(fh.content))
+	}
+	return fuse.ReadResultData(fh.content[off:end]), 0
+}
+
+var _ fs.FileFlusher = (*sensorFileReadHandle)(nil)
+func (fh *sensorFileReadHandle) Flush(ctx context.Context) (errno syscall.Errno) {
+	return 0
+}
+
+
+type bytesFileWriteHandle struct {
+	content []byte
+	path string
+}
+
+var _ fs.FileWriter = (*bytesFileWriteHandle)(nil)
+func (fh *bytesFileWriteHandle) Write(ctx context.Context, data []byte, off int64) (written uint32, errno syscall.Errno) {
+	log.Info("Executing Write").Str("path", fh.path).Int("prev_size", len(fh.content)).Int("next_size", len(data)).Send()
+	if off != int64(len(fh.content)) {
+		log.Error("FUSE Write file size changed unexpectedly").Int("expect", int(off)).Int("received", len(fh.content)).Send()
+		return 0, syscall.ENXIO
+	}
+	fh.content = append(fh.content[:], data[:]...)
+	return uint32(len(data)), 0
+}
+
+var _ fs.FileFlusher = (*bytesFileWriteHandle)(nil)
+func (fh *bytesFileWriteHandle) Flush(ctx context.Context) (errno syscall.Errno) {
+
+	log.Debug("FUSE Attempting flush").Str("path", fh.path).Send()
+	fp, err := myfs.Create(fh.path, uint32(len(fh.content)))
+	if err != nil {
+		log.Error("FUSE Flush failed: create").Str("path", fh.path).Err(err).Send()
+		return syscallErr(err)
+	}
+
+	if len(fh.content) == 0 {
+		log.Debug("FUSE Flush no data to write").Str("path", fh.path).Send()
+		err = fp.Close()
+		if err != nil {
+			log.Error("FUSE Flush failed during close").Str("path", fh.path).Err(err).Send()
+			return syscallErr(err)
+		}
+		return 0
+	}
+
+	go func() {
+		// For every progress event
+		for sent := range fp.Progress() {
+			log.Debug("FUSE Flush progress").Int("bytes", int(sent)).Int("total", len(fh.content)).Send()
+		}
+	}()
+
+	r := bytes.NewReader(fh.content)
+	nread, err := io.Copy(fp, r)
+	if err != nil {
+		log.Error("FUSE Flush failed during write").Str("path", fh.path).Err(err).Send()
+		fp.Close()
+		return syscallErr(err)
+	}
+	if int(nread) != len(fh.content) {
+		log.Error("FUSE Flush failed during write").Str("path", fh.path).Int("expect", len(fh.content)).Int("got", int(nread)).Send()
+		fp.Close()
+		return syscall.EIO
+	}
+	err = fp.Close()
+	if err != nil {
+		log.Error("FUSE Flush failed during close").Str("path", fh.path).Err(err).Send()
+		return syscallErr(err)
+	}
+	log.Debug("FUSE Flush done").Str("path", fh.path).Int("size", len(fh.content)).Send()
+
+	return 0
+}
+var _ fs.FileFsyncer = (*bytesFileWriteHandle)(nil)
+func (fh *bytesFileWriteHandle) Fsync(ctx context.Context, flags uint32) (errno syscall.Errno) {
+	return fh.Flush(ctx)
+}
+
+var _ fs.NodeGetattrer = (*ITNode)(nil)
+func (bn *ITNode) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
+	log.Debug("FUSE getattr").Str("path", bn.path).Send()
+	out.Ino = bn.Ino
+	out.Mtime = bn.self.modtime
+	out.Ctime = bn.self.modtime
+	out.Atime = bn.self.modtime
+	out.Size = uint64(bn.self.size)
+	return 0
+}
+
+var _ fs.NodeSetattrer = (*ITNode)(nil)
+func (bn *ITNode) Setattr(ctx context.Context, fh fs.FileHandle, in *fuse.SetAttrIn, out *fuse.AttrOut) syscall.Errno {
+	log.Debug("FUSE setattr").Str("path", bn.path).Send()
+	out.Size = 0
+	out.Mtime = 0
+	return 0
+}
+
+var _ fs.NodeOpener = (*ITNode)(nil)
+func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
+	switch f.kind {
+	case 2:
+		// FS file
+		if openFlags&syscall.O_RDWR != 0 {
+			log.Error("FUSE Open failed: RDWR").Str("path", f.path).Send()
+			return nil, 0, syscall.EROFS
+		}
+
+		if openFlags & syscall.O_WRONLY != 0 {
+			log.Debug("FUSE Opening for write").Str("path", f.path).Send()
+			fh = &bytesFileWriteHandle{
+				path : f.path,
+				content : make([]byte, 0),
+			}
+			return fh, fuse.FOPEN_DIRECT_IO, 0
+		} else {
+			log.Debug("FUSE Opening for read").Str("path", f.path).Send()
+			fp, err := myfs.Open(f.path)
+			if err != nil {
+				log.Error("FUSE: Opening failed").Str("path", f.path).Err(err).Send()
+				return nil, 0, syscallErr(err)
+			}
+
+			defer fp.Close()
+
+			b := &bytes.Buffer{}
+
+			go func() {
+				// For every progress event
+				for sent := range fp.Progress() {
+					log.Debug("FUSE Read progress").Int("bytes", int(sent)).Int("total", int(f.self.size)).Send()
+				}
+			}()
+
+			_, err = io.Copy(b, fp)
+			if err != nil {
+				log.Error("FUSE Read failed").Str("path", f.path).Err(err).Send()
+				fp.Close()
+				return nil, 0, syscallErr(err)
+			}
+
+			fh = &bytesFileReadHandle{
+				content: b.Bytes(),
+			}
+			return fh, fuse.FOPEN_DIRECT_IO, 0
+		}
+
+	case 3:
+		// Device file
+
+		// disallow writes
+		if openFlags&(syscall.O_RDWR|syscall.O_WRONLY) != 0 {
+			return nil, 0, syscall.EROFS
+		}
+
+		for _, value := range properties {
+			if value.Ino == f.Ino {
+				ans, err := value.gen()
+				if err != nil {
+					return nil, 0, syscallErr(err)
+				}
+
+				fh = &sensorFileReadHandle{
+					content : ans,
+				}
+				return fh, fuse.FOPEN_DIRECT_IO, 0
+			}
+		}
+	}
+	return nil, 0, syscall.EINVAL
+}
+
+var _ fs.NodeCreater = (*ITNode)(nil)
+func (f *ITNode) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (node *fs.Inode, fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
+	if f.kind != 2 {
+		return nil, nil, 0, syscall.EROFS
+	}
+
+	path := f.path + "/" + name
+	ino := uint64(len(inodemap)) + 11
+	inodemap[path] = ino
+
+	stable := fs.StableAttr{
+		Mode: fuse.S_IFREG,
+		Ino: ino,
+	}
+	operations := &ITNode{
+		kind: 2, Ino: ino,
+		path : path,
+	}
+	node = f.NewInode(ctx, operations, stable)
+
+	fh = &bytesFileWriteHandle{
+		path : path,
+		content : make([]byte, 0),
+	}
+
+	log.Debug("FUSE Creating file").Str("path", path).Send()
+
+	errno = 0
+	return node, fh, fuseFlags, 0
+}
+
+var _ fs.NodeMkdirer = (*ITNode)(nil)
+func (f *ITNode) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
+	if f.kind != 2 {
+		return nil, syscall.EROFS
+	}
+
+	path := f.path + "/" + name
+	err := myfs.Mkdir(path)
+	if err != nil {
+		log.Error("FUSE Mkdir failed").
+			Str("path", path).
+			Err(err).
+			Send()
+		return nil, syscallErr(err)
+	}
+
+	ino := uint64(len(inodemap)) + 11
+	inodemap[path] = ino
+
+	stable := fs.StableAttr{
+		Mode: fuse.S_IFDIR,
+		Ino: ino,
+	}
+	operations := &ITNode{
+		kind: 2, Ino: ino,
+		path : path,
+	}
+	node := f.NewInode(ctx, operations, stable)
+
+	log.Debug("FUSE Mkdir success").
+		Str("path", path).
+		Int("ino", int(ino)).
+		Send()
+	return node, 0
+}
+
+var _ fs.NodeRenamer = (*ITNode)(nil)
+func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbedder, newName string, flags uint32) syscall.Errno {
+	if f.kind != 2 {
+		return syscall.EROFS
+	}
+
+	p1 := f.path + "/" + name
+	p2 := newParent.EmbeddedInode().Path(nil)[2:] + "/" + newName
+
+	err := myfs.Rename(p1, p2)
+	if err != nil {
+		log.Error("FUSE Rename failed").
+			Str("src", p1).
+			Str("dest", p2).
+			Err(err).
+			Send()
+
+		return syscallErr(err)
+	}
+	log.Debug("FUSE Rename sucess").
+		Str("src", p1).
+		Str("dest", p2).
+		Send()
+
+	ino := inodemap[p1]
+	delete(inodemap, p1)
+	inodemap[p2] = ino
+
+	return 0
+}
+
+var _ fs.NodeUnlinker = (*ITNode)(nil)
+func (f *ITNode) Unlink(ctx context.Context, name string) syscall.Errno {
+	if f.kind != 2 {
+		return syscall.EROFS
+	}
+
+	delete(inodemap, f.path + "/" + name)
+	err := myfs.Remove(f.path + "/" + name)
+	if err != nil {
+		log.Error("FUSE Unlink failed").
+			Str("file", f.path + "/" + name).
+			Err(err).
+			Send()
+
+		return syscallErr(err)
+	}
+
+	log.Debug("FUSE Unlink success").
+		Str("file", f.path + "/" + name).
+		Send()
+	return 0
+}
+
+var _ fs.NodeRmdirer = (*ITNode)(nil)
+func (f *ITNode) Rmdir(ctx context.Context, name string) syscall.Errno {
+	return f.Unlink(ctx, name)
+}

internal/fusefs/syscallerr.go

@@ -0,0 +1,67 @@
+package fusefs
+import (
+	"go.arsenm.dev/infinitime/blefs"
+	"syscall"
+)
+
+func syscallErr(err error) syscall.Errno {
+	if err == nil {
+		return 0
+	}
+
+	switch err {
+	case blefs.FSError{0x02}: // filesystem error
+		return syscall.EIO // TODO
+	case blefs.FSError{0x05}: // read-only filesystem
+		return syscall.EROFS
+	case blefs.FSError{0x03}: // no such file
+		return syscall.ENOENT
+	case blefs.FSError{0x04}: // protocol error
+		return syscall.EPROTO
+	case blefs.FSError{-5}: // input/output error
+		return syscall.EIO
+	case blefs.FSError{-84}: // filesystem is corrupted
+		return syscall.ENOTRECOVERABLE // TODO
+	case blefs.FSError{-2}: // no such directory entry
+		return syscall.ENOENT
+	case blefs.FSError{-17}: // entry already exists
+		return syscall.EEXIST
+	case blefs.FSError{-20}: // entry is not a directory
+		return syscall.ENOTDIR
+	case blefs.FSError{-39}: // directory is not empty
+		return syscall.ENOTEMPTY
+	case blefs.FSError{-9}: // bad file number
+		return syscall.EBADF
+	case blefs.FSError{-27}: // file is too large
+		return syscall.EFBIG
+	case blefs.FSError{-22}: // invalid parameter
+		return syscall.EINVAL
+	case blefs.FSError{-28}: // no space left on device
+		return syscall.ENOSPC
+	case blefs.FSError{-12}: // no more memory available
+		return syscall.ENOMEM
+	case blefs.FSError{-61}: // no attr available
+		return syscall.ENODATA // TODO
+	case blefs.FSError{-36}: // file name is too long
+		return syscall.ENAMETOOLONG
+	case blefs.ErrFileNotExists: // file does not exist
+		return syscall.ENOENT
+	case blefs.ErrFileReadOnly: // file is read only
+		return syscall.EACCES
+	case blefs.ErrFileWriteOnly: // file is write only
+		return syscall.EACCES
+	case blefs.ErrInvalidOffset: // invalid file offset
+		return syscall.EFAULT  // TODO
+	case blefs.ErrOffsetChanged: // offset has already been changed
+		return syscall.ESPIPE
+	case blefs.ErrReadOpen: // only one file can be opened for reading at a time
+		return syscall.ENFILE
+	case blefs.ErrWriteOpen: // only one file can be opened for writing at a time
+		return syscall.ENFILE
+	case blefs.ErrNoRemoveRoot: // refusing to remove root directory
+		return syscall.EPERM
+	}
+
+	return syscall.EIO // TODO
+
+}

internal/fusefs/unmount.go

@@ -0,0 +1,15 @@
+package fusefs
+
+import (
+	_ "unsafe"
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+func Unmount(mountPoint string) error {
+	return unmount(mountPoint, &fuse.MountOptions{DirectMount: false})
+}
+
+// Unfortunately, the FUSE library does not export its unmount function,
+// so this is required until that changes
+//go:linkname unmount github.com/hanwen/go-fuse/v2/fuse.unmount
+func unmount(mountPoint string, opts *fuse.MountOptions) error

main.go

@@ -181,6 +181,14 @@ func main() {
 		log.Error("Error intializing puremaps integration").Err(err).Send()
 	}
 
+	// Start fuse socket
+	if k.Bool("fuse.enabled") {
+		err = startFUSE(ctx, dev)
+		if err != nil {
+			log.Error("Error starting fuse socket").Err(err).Send()
+		}
+	}
+
 	// Start control socket
 	err = startSocket(ctx, dev)
 	if err != nil {