Package fuse provides APIs to implement filesystems in userspace in terms of raw FUSE protocol.

A filesystem is implemented by implementing its server that provides a RawFileSystem interface. Typically the server embeds NewDefaultRawFileSystem() and implements only subset of filesystem methods:

type MyFS struct {

func NewMyFS() *MyFS {
	return &MyFS{
		RawFileSystem: fuse.NewDefaultRawFileSystem(),

// Mkdir implements "mkdir" request handler.
// For other requests - not explicitly implemented by MyFS - ENOSYS
// will be typically returned to client.
func (fs *MyFS) Mkdir(...) {

Then the filesystem can be mounted and served to a client (typically OS kernel) by creating Server:

fs := NewMyFS() // implements RawFileSystem
fssrv, err := fuse.NewServer(fs, mountpoint, &fuse.MountOptions{...})
if err != nil {

and letting the server do its work:

// either synchronously - .Serve() blocks until the filesystem is unmounted.

// or in the background - .Serve() is spawned in another goroutine, but
// before interacting with fssrv from current context we have to wait
// until the filesystem mounting is complete.
go fssrv.Serve()
err = fssrv.WaitMount()
if err != nil {

The server will serve clients by dispatching their requests to the filesystem implementation and conveying responses back. For example "mkdir" FUSE request dispatches to call

fs.Mkdir(*MkdirIn, ..., *EntryOut)

"stat" to call

fs.GetAttr(*GetAttrIn, *AttrOut)

etc. Please refer to RawFileSystem documentation for details.

Typically, each call of the API happens in its own goroutine, so take care to make the file system thread-safe.

Higher level interfaces

As said above this packages provides way to implement filesystems in terms of raw FUSE protocol. Additionally packages nodefs and pathfs provide ways to implement filesystem at higher levels:

Package provides way to implement filesystems in terms of inodes. This resembles kernel's idea of what a filesystem looks like.

Package provides way to implement filesystems in terms of path names. Working with path names is somewhat easier compared to inodes, however renames can be racy. Do not use pathfs if you care about correctness.



View Source
const (

	FUSE_UNKNOWN_INO = 0xffffffff


	FUSE_LK_FLOCK = (1 << 0)




	S_IFDIR = syscall.S_IFDIR
	S_IFREG = syscall.S_IFREG
	S_IFLNK = syscall.S_IFLNK
	S_IFIFO = syscall.S_IFIFO

	CUSE_INIT = 4096

	O_ANYWRITE = uint32(os.O_WRONLY | os.O_RDWR | os.O_APPEND | os.O_CREATE | os.O_TRUNC)
View Source
const (
	OK = Status(0)

	// EACCESS Permission denied
	EACCES = Status(syscall.EACCES)

	// EBUSY Device or resource busy
	EBUSY = Status(syscall.EBUSY)

	// EAGAIN Resource temporarily unavailable
	EAGAIN = Status(syscall.EAGAIN)

	// EINVAL Invalid argument
	EINVAL = Status(syscall.EINVAL)

	// EIO I/O error
	EIO = Status(syscall.EIO)

	// ENOENT No such file or directory
	ENOENT = Status(syscall.ENOENT)

	// ENOSYS Function not implemented
	ENOSYS = Status(syscall.ENOSYS)

	// ENODATA No data available
	ENODATA = Status(syscall.ENODATA)

	// ENOTDIR Not a directory
	ENOTDIR = Status(syscall.ENOTDIR)

	// EISDIR Is a directory
	EISDIR = Status(syscall.EISDIR)

	// EPERM Operation not permitted
	EPERM = Status(syscall.EPERM)

	// ERANGE Math result not representable
	ERANGE = Status(syscall.ERANGE)

	// EXDEV Cross-device link
	EXDEV = Status(syscall.EXDEV)

	// EBADF Bad file number
	EBADF = Status(syscall.EBADF)

	// ENODEV No such device
	ENODEV = Status(syscall.ENODEV)

	// EROFS Read-only file system
	EROFS = Status(syscall.EROFS)
View Source
const (
	FATTR_MODE      = (1 << 0)
	FATTR_UID       = (1 << 1)
	FATTR_GID       = (1 << 2)
	FATTR_SIZE      = (1 << 3)
	FATTR_ATIME     = (1 << 4)
	FATTR_MTIME     = (1 << 5)
	FATTR_FH        = (1 << 6)
	FATTR_ATIME_NOW = (1 << 7)
	FATTR_MTIME_NOW = (1 << 8)
	FATTR_CTIME     = (1 << 10)
View Source
const (
	// OpenOut.Flags
	FOPEN_DIRECT_IO   = (1 << 0)
	FOPEN_KEEP_CACHE  = (1 << 1)
View Source
const (
	CAP_ASYNC_READ         = (1 << 0)
	CAP_POSIX_LOCKS        = (1 << 1)
	CAP_FILE_OPS           = (1 << 2)
	CAP_ATOMIC_O_TRUNC     = (1 << 3)
	CAP_EXPORT_SUPPORT     = (1 << 4)
	CAP_BIG_WRITES         = (1 << 5)
	CAP_DONT_MASK          = (1 << 6)
	CAP_SPLICE_WRITE       = (1 << 7)
	CAP_SPLICE_MOVE        = (1 << 8)
	CAP_SPLICE_READ        = (1 << 9)
	CAP_FLOCK_LOCKS        = (1 << 10)
	CAP_IOCTL_DIR          = (1 << 11)
	CAP_AUTO_INVAL_DATA    = (1 << 12)
	CAP_READDIRPLUS        = (1 << 13)
	CAP_ASYNC_DIO          = (1 << 15)
	CAP_WRITEBACK_CACHE    = (1 << 16)
	CAP_NO_OPEN_SUPPORT    = (1 << 17)
	CAP_PARALLEL_DIROPS    = (1 << 18)
	CAP_HANDLE_KILLPRIV    = (1 << 19)
	CAP_POSIX_ACL          = (1 << 20)
	CAP_ABORT_ERROR        = (1 << 21)
	CAP_MAX_PAGES          = (1 << 22)
	CAP_CACHE_SYMLINKS     = (1 << 23)

    To be set in InitIn/InitOut.Flags.

    View Source
    const (
    	FUSE_IOCTL_COMPAT       = (1 << 0)
    	FUSE_IOCTL_RETRY        = (1 << 2)
    View Source
    const (
    	X_OK = 1
    	W_OK = 2
    	R_OK = 4
    	F_OK = 0

      For AccessIn.Mask.

      View Source
      const (
      	//	NOTIFY_POLL         = -1 // notify kernel that a poll waiting for IO on a file handle should wake up
      	NOTIFY_INVAL_INODE    = -2 // notify kernel that an inode should be invalidated
      	NOTIFY_INVAL_ENTRY    = -3 // notify kernel that a directory entry should be invalidated
      	NOTIFY_STORE_CACHE    = -4 // store data into kernel cache of an inode
      	NOTIFY_RETRIEVE_CACHE = -5 // retrieve data from kernel cache of an inode
      	NOTIFY_DELETE         = -6 // notify kernel that a directory entry has been deleted
      View Source
      const (
      	WRITE_CACHE     = (1 << 0)
      	WRITE_LOCKOWNER = (1 << 1)
      View Source
      const (
      	ENOATTR = Status(syscall.ENODATA) // On Linux, ENOATTR is an alias for ENODATA.
      	// EREMOTEIO Remote I/O error
      	EREMOTEIO = Status(syscall.EREMOTEIO)
      View Source
      const (
      	// Mask for GetAttrIn.Flags. If set, GetAttrIn has a file handle set.
      	FUSE_GETATTR_FH = (1 << 0)
      View Source
      const (
      	// The kernel caps writes at 128k.
      	MAX_KERNEL_WRITE = 128 * 1024
      View Source
      const (
      	READ_LOCKOWNER = (1 << 1)
      View Source
      const RELEASE_FLUSH = (1 << 0)


      View Source
      var FuseOpenFlagNames map[int64]string
      View Source
      var OpenFlagNames map[int64]string


      func FlagString

      func FlagString(names map[int64]string, fl int64, def string) string

      func Print

      func Print(obj interface{}) string

        Print pretty prints FUSE data types for kernel communication

        func ToStatT

        func ToStatT(f os.FileInfo) *syscall.Stat_t

        func UtimeToTimespec

        func UtimeToTimespec(t *time.Time) (ts syscall.Timespec)

          UtimeToTimespec converts a "Time" pointer as passed to Utimens to a "Timespec" that can be passed to the utimensat syscall. A nil pointer is converted to the special UTIME_OMIT value.


          type AccessIn

          type AccessIn struct {
          	Mask    uint32
          	Padding uint32

          type Attr

          type Attr struct {
          	Ino       uint64
          	Size      uint64
          	Blocks    uint64
          	Atime     uint64
          	Mtime     uint64
          	Ctime     uint64
          	Atimensec uint32
          	Mtimensec uint32
          	Ctimensec uint32
          	Mode      uint32
          	Nlink     uint32
          	Rdev    uint32
          	Blksize uint32
          	Padding uint32

          func ToAttr

          func ToAttr(f os.FileInfo) *Attr

          func (*Attr) AccessTime

          func (a *Attr) AccessTime() time.Time

          func (*Attr) ChangeTime

          func (a *Attr) ChangeTime() time.Time

          func (*Attr) FromStat

          func (a *Attr) FromStat(s *syscall.Stat_t)

          func (*Attr) IsBlock

          func (a *Attr) IsBlock() bool

            IsBlock reports whether the FileInfo describes a block special file.

            func (*Attr) IsChar

            func (a *Attr) IsChar() bool

              IsChar reports whether the FileInfo describes a character special file.

              func (*Attr) IsDir

              func (a *Attr) IsDir() bool

                IsDir reports whether the FileInfo describes a directory.

                func (*Attr) IsFifo

                func (a *Attr) IsFifo() bool

                func (*Attr) IsRegular

                func (a *Attr) IsRegular() bool

                  IsRegular reports whether the FileInfo describes a regular file.

                  func (*Attr) IsSocket

                  func (a *Attr) IsSocket() bool

                    IsSocket reports whether the FileInfo describes a socket.

                    func (a *Attr) IsSymlink() bool

                      IsSymlink reports whether the FileInfo describes a symbolic link.

                      func (*Attr) ModTime

                      func (a *Attr) ModTime() time.Time

                      func (*Attr) SetTimes

                      func (a *Attr) SetTimes(access *time.Time, mod *time.Time, chstatus *time.Time)

                      func (*Attr) String

                      func (a *Attr) String() string

                      type AttrOut

                      type AttrOut struct {
                      	AttrValid     uint64
                      	AttrValidNsec uint32
                      	Dummy         uint32

                      func (*AttrOut) SetTimeout

                      func (o *AttrOut) SetTimeout(dt time.Duration)

                      type BufferPool

                      type BufferPool interface {
                      	// AllocBuffer creates a buffer of at least the given size. After use,
                      	// it should be deallocated with FreeBuffer().
                      	AllocBuffer(size uint32) []byte
                      	// FreeBuffer takes back a buffer if it was allocated through
                      	// AllocBuffer.  It is not an error to call FreeBuffer() on a slice
                      	// obtained elsewhere.
                      	FreeBuffer(slice []byte)

                        BufferPool implements explicit memory management. It is used for minimizing the GC overhead of communicating with the kernel.

                        func NewBufferPool

                        func NewBufferPool() BufferPool

                          NewBufferPool returns a BufferPool implementation that that returns slices with capacity of a multiple of page size, which have possibly been used, and may contain random contents. When using NewBufferPool, file system handlers may not hang on to passed-in buffers beyond the handler's return.

                          func NewGcBufferPool

                          func NewGcBufferPool() BufferPool

                            NewGcBufferPool is a fallback to the standard allocation routines.

                            type Context

                            type Context struct {
                            	Pid uint32

                            type CreateIn

                            type CreateIn struct {
                            	Flags uint32
                            	// Mode for the new file; already takes Umask into account.
                            	Mode uint32
                            	// Umask used for this create call.
                            	Umask   uint32
                            	Padding uint32

                            type CreateOut

                            type CreateOut struct {

                            type DirEntry

                            type DirEntry struct {
                            	// Mode is the file's mode. Only the high bits (eg. S_IFDIR)
                            	// are considered.
                            	Mode uint32
                            	// Name is the basename of the file in the directory.
                            	Name string
                            	// Ino is the inode number.
                            	Ino uint64

                              DirEntry is a type for PathFileSystem and NodeFileSystem to return directory contents in.

                              func (DirEntry) String

                              func (d DirEntry) String() string

                              type DirEntryList

                              type DirEntryList struct {
                              	// contains filtered or unexported fields

                                DirEntryList holds the return value for READDIR and READDIRPLUS opcodes.

                                func NewDirEntryList

                                func NewDirEntryList(data []byte, off uint64) *DirEntryList

                                  NewDirEntryList creates a DirEntryList with the given data buffer and offset.

                                  func (*DirEntryList) Add

                                  func (l *DirEntryList) Add(prefix int, name string, inode uint64, mode uint32) bool

                                    Add adds a direntry to the DirEntryList, returning whether it succeeded.

                                    func (*DirEntryList) AddDirEntry

                                    func (l *DirEntryList) AddDirEntry(e DirEntry) bool

                                      AddDirEntry tries to add an entry, and reports whether it succeeded.

                                      func (*DirEntryList) AddDirLookupEntry

                                      func (l *DirEntryList) AddDirLookupEntry(e DirEntry) *EntryOut

                                        AddDirLookupEntry is used for ReadDirPlus. It serializes a DirEntry and returns the space for entry. If no space is left, returns a nil pointer.

                                        type EntryOut

                                        type EntryOut struct {
                                        	NodeId         uint64
                                        	Generation     uint64
                                        	EntryValid     uint64
                                        	AttrValid      uint64
                                        	EntryValidNsec uint32
                                        	AttrValidNsec  uint32

                                        func (*EntryOut) SetAttrTimeout

                                        func (o *EntryOut) SetAttrTimeout(dt time.Duration)

                                        func (*EntryOut) SetEntryTimeout

                                        func (o *EntryOut) SetEntryTimeout(dt time.Duration)

                                        type FallocateIn

                                        type FallocateIn struct {
                                        	Fh      uint64
                                        	Offset  uint64
                                        	Length  uint64
                                        	Mode    uint32
                                        	Padding uint32

                                        type FileLock

                                        type FileLock struct {
                                        	Start uint64
                                        	End   uint64
                                        	Typ   uint32
                                        	Pid   uint32

                                        func (*FileLock) FromFlockT

                                        func (lk *FileLock) FromFlockT(flockT *syscall.Flock_t)

                                        func (*FileLock) ToFlockT

                                        func (lk *FileLock) ToFlockT(flockT *syscall.Flock_t)

                                        type FlushIn

                                        type FlushIn struct {
                                        	Fh        uint64
                                        	Unused    uint32
                                        	Padding   uint32
                                        	LockOwner uint64

                                        type ForgetIn

                                        type ForgetIn struct {
                                        	Nlookup uint64

                                        type FsyncIn

                                        type FsyncIn struct {
                                        	Fh         uint64
                                        	FsyncFlags uint32
                                        	Padding    uint32

                                        type GetAttrIn

                                        type GetAttrIn struct {
                                        	Flags_ uint32
                                        	Dummy  uint32
                                        	Fh_    uint64

                                        func (*GetAttrIn) Fh

                                        func (g *GetAttrIn) Fh() uint64

                                          Fh accesses the file handle. This is a method, because OSXFuse does not have GetAttrIn flags.

                                          func (*GetAttrIn) Flags

                                          func (g *GetAttrIn) Flags() uint32

                                            Flags accesses the flags. This is a method, because OSXFuse does not have GetAttrIn flags.

                                            type GetXAttrIn

                                            type GetXAttrIn struct {
                                            	Size    uint32
                                            	Padding uint32

                                            type GetXAttrOut

                                            type GetXAttrOut struct {
                                            	Size    uint32
                                            	Padding uint32

                                            type InHeader

                                            type InHeader struct {
                                            	Length uint32
                                            	Opcode int32
                                            	Unique uint64
                                            	NodeId uint64
                                            	Padding uint32

                                            type InitIn

                                            type InitIn struct {
                                            	Major        uint32
                                            	Minor        uint32
                                            	MaxReadAhead uint32
                                            	Flags        uint32

                                            func (*InitIn) SupportsNotify

                                            func (in *InitIn) SupportsNotify(notifyType int) bool

                                              SupportsNotify returns whether a certain notification type is supported. Pass any of the NOTIFY_* types as argument.

                                              func (*InitIn) SupportsVersion

                                              func (in *InitIn) SupportsVersion(maj, min uint32) bool

                                                SupportsVersion returns true if the kernel supports the given protocol version or newer.

                                                type InitOut

                                                type InitOut struct {
                                                	Major               uint32
                                                	Minor               uint32
                                                	MaxReadAhead        uint32
                                                	Flags               uint32
                                                	MaxBackground       uint16
                                                	CongestionThreshold uint16
                                                	MaxWrite            uint32
                                                	TimeGran            uint32
                                                	Unused              [9]uint32

                                                type InterruptIn

                                                type InterruptIn struct {
                                                	Unique uint64

                                                type LatencyMap

                                                type LatencyMap interface {
                                                	Add(name string, dt time.Duration)

                                                  This type may be provided for recording latencies of each FUSE operation.

                                                  type LinkIn

                                                  type LinkIn struct {
                                                  	Oldnodeid uint64

                                                  type LkIn

                                                  type LkIn struct {
                                                  	Fh      uint64
                                                  	Owner   uint64
                                                  	Lk      FileLock
                                                  	LkFlags uint32
                                                  	Padding uint32

                                                  type LkOut

                                                  type LkOut struct {
                                                  	Lk FileLock

                                                  type MkdirIn

                                                  type MkdirIn struct {
                                                  	// The mode for the new directory. The calling process' umask
                                                  	// is already factored into the mode.
                                                  	Mode  uint32
                                                  	Umask uint32

                                                  type MknodIn

                                                  type MknodIn struct {
                                                  	// Mode to use, including the Umask value
                                                  	Mode    uint32
                                                  	Rdev    uint32
                                                  	Umask   uint32
                                                  	Padding uint32

                                                  type MountOptions

                                                  type MountOptions struct {
                                                  	AllowOther bool
                                                  	// Options are passed as -o string to fusermount.
                                                  	Options []string
                                                  	// Default is _DEFAULT_BACKGROUND_TASKS, 12.  This numbers
                                                  	// controls the allowed number of requests that relate to
                                                  	// async I/O.  Concurrency for synchronous I/O is not limited.
                                                  	MaxBackground int
                                                  	// Write size to use.  If 0, use default. This number is
                                                  	// capped at the kernel maximum.
                                                  	MaxWrite int
                                                  	// Max read ahead to use.  If 0, use default. This number is
                                                  	// capped at the kernel maximum.
                                                  	MaxReadAhead int
                                                  	// If IgnoreSecurityLabels is set, all security related xattr
                                                  	// requests will return NO_DATA without passing through the
                                                  	// user defined filesystem.  You should only set this if you
                                                  	// file system implements extended attributes, and you are not
                                                  	// interested in security labels.
                                                  	IgnoreSecurityLabels bool // ignoring labels should be provided as a fusermount mount option.
                                                  	// If given, use this buffer pool instead of the global one.
                                                  	Buffers BufferPool
                                                  	// If RememberInodes is set, we will never forget inodes.
                                                  	// This may be useful for NFS.
                                                  	RememberInodes bool
                                                  	// Values shown in "df -T" and friends
                                                  	// First column, "Filesystem"
                                                  	FsName string
                                                  	// Second column, "Type", will be shown as "fuse." + Name
                                                  	Name string
                                                  	// If set, wrap the file system in a single-threaded locking wrapper.
                                                  	SingleThreaded bool
                                                  	// If set, return ENOSYS for Getxattr calls, so the kernel does not issue any
                                                  	// Xattr operations at all.
                                                  	DisableXAttrs bool
                                                  	// If set, print debugging information.
                                                  	Debug bool
                                                  	// If set, ask kernel to forward file locks to FUSE. If using,
                                                  	// you must implement the GetLk/SetLk/SetLkw methods.
                                                  	EnableLocks bool

                                                  type NotifyInvalDeleteOut

                                                  type NotifyInvalDeleteOut struct {
                                                  	Parent  uint64
                                                  	Child   uint64
                                                  	NameLen uint32
                                                  	Padding uint32

                                                  type NotifyInvalEntryOut

                                                  type NotifyInvalEntryOut struct {
                                                  	Parent  uint64
                                                  	NameLen uint32
                                                  	Padding uint32

                                                  type NotifyInvalInodeOut

                                                  type NotifyInvalInodeOut struct {
                                                  	Ino    uint64
                                                  	Off    int64
                                                  	Length int64

                                                  type NotifyRetrieveIn

                                                  type NotifyRetrieveIn struct {
                                                  	Dummy1 uint64
                                                  	Offset uint64
                                                  	Size   uint32
                                                  	Dummy2 uint32
                                                  	Dummy3 uint64
                                                  	Dummy4 uint64

                                                  type NotifyRetrieveOut

                                                  type NotifyRetrieveOut struct {
                                                  	NotifyUnique uint64
                                                  	Nodeid       uint64
                                                  	Offset       uint64
                                                  	Size         uint32
                                                  	Padding      uint32

                                                  type NotifyStoreOut

                                                  type NotifyStoreOut struct {
                                                  	Nodeid  uint64
                                                  	Offset  uint64
                                                  	Size    uint32
                                                  	Padding uint32

                                                  type OpenIn

                                                  type OpenIn struct {
                                                  	Flags uint32
                                                  	Mode  uint32

                                                  type OpenOut

                                                  type OpenOut struct {
                                                  	Fh        uint64
                                                  	OpenFlags uint32
                                                  	Padding   uint32

                                                  type OutHeader

                                                  type OutHeader struct {
                                                  	Length uint32
                                                  	Status int32
                                                  	Unique uint64

                                                  type Owner

                                                  type Owner struct {
                                                  	Uid uint32
                                                  	Gid uint32

                                                  func CurrentOwner

                                                  func CurrentOwner() *Owner

                                                  type RawFileSystem

                                                  type RawFileSystem interface {
                                                  	String() string
                                                  	// If called, provide debug output through the log package.
                                                  	SetDebug(debug bool)
                                                  	// Lookup is called by the kernel when the VFS wants to know
                                                  	// about a file inside a directory. Many lookup calls can
                                                  	// occur in parallel, but only one call happens for each (dir,
                                                  	// name) pair.
                                                  	Lookup(header *InHeader, name string, out *EntryOut) (status Status)
                                                  	// Forget is called when the kernel discards entries from its
                                                  	// dentry cache. This happens on unmount, and when the kernel
                                                  	// is short on memory. Since it is not guaranteed to occur at
                                                  	// any moment, and since there is no return value, Forget
                                                  	// should not do I/O, as there is no channel to report back
                                                  	// I/O errors.
                                                  	Forget(nodeid, nlookup uint64)
                                                  	// Attributes.
                                                  	GetAttr(input *GetAttrIn, out *AttrOut) (code Status)
                                                  	SetAttr(input *SetAttrIn, out *AttrOut) (code Status)
                                                  	// Modifying structure.
                                                  	Mknod(input *MknodIn, name string, out *EntryOut) (code Status)
                                                  	Mkdir(input *MkdirIn, name string, out *EntryOut) (code Status)
                                                  	Unlink(header *InHeader, name string) (code Status)
                                                  	Rmdir(header *InHeader, name string) (code Status)
                                                  	Rename(input *RenameIn, oldName string, newName string) (code Status)
                                                  	Link(input *LinkIn, filename string, out *EntryOut) (code Status)
                                                  	Symlink(header *InHeader, pointedTo string, linkName string, out *EntryOut) (code Status)
                                                  	Readlink(header *InHeader) (out []byte, code Status)
                                                  	Access(input *AccessIn) (code Status)
                                                  	// Extended attributes.
                                                  	GetXAttrSize(header *InHeader, attr string) (sz int, code Status)
                                                  	GetXAttrData(header *InHeader, attr string) (data []byte, code Status)
                                                  	ListXAttr(header *InHeader) (attributes []byte, code Status)
                                                  	SetXAttr(input *SetXAttrIn, attr string, data []byte) Status
                                                  	RemoveXAttr(header *InHeader, attr string) (code Status)
                                                  	// File handling.
                                                  	Create(input *CreateIn, name string, out *CreateOut) (code Status)
                                                  	Open(input *OpenIn, out *OpenOut) (status Status)
                                                  	Read(input *ReadIn, buf []byte) (ReadResult, Status)
                                                  	// File locking
                                                  	GetLk(input *LkIn, out *LkOut) (code Status)
                                                  	SetLk(input *LkIn) (code Status)
                                                  	SetLkw(input *LkIn) (code Status)
                                                  	Release(input *ReleaseIn)
                                                  	Write(input *WriteIn, data []byte) (written uint32, code Status)
                                                  	Flush(input *FlushIn) Status
                                                  	Fsync(input *FsyncIn) (code Status)
                                                  	Fallocate(input *FallocateIn) (code Status)
                                                  	// Directory handling
                                                  	OpenDir(input *OpenIn, out *OpenOut) (status Status)
                                                  	ReadDir(input *ReadIn, out *DirEntryList) Status
                                                  	ReadDirPlus(input *ReadIn, out *DirEntryList) Status
                                                  	ReleaseDir(input *ReleaseIn)
                                                  	FsyncDir(input *FsyncIn) (code Status)
                                                  	StatFs(input *InHeader, out *StatfsOut) (code Status)
                                                  	// This is called on processing the first request. The
                                                  	// filesystem implementation can use the server argument to
                                                  	// talk back to the kernel (through notify methods).

                                                    RawFileSystem is an interface close to the FUSE wire protocol.

                                                    Unless you really know what you are doing, you should not implement this, but rather the nodefs.Node or pathfs.FileSystem interfaces; the details of getting interactions with open files, renames, and threading right etc. are somewhat tricky and not very interesting.

                                                    Each FUSE request results in a corresponding method called by Server. Several calls may be made simultaneously, because the server typically calls each method in separate goroutine.

                                                    A null implementation is provided by NewDefaultRawFileSystem.

                                                    func NewDefaultRawFileSystem

                                                    func NewDefaultRawFileSystem() RawFileSystem

                                                      NewDefaultRawFileSystem returns ENOSYS (not implemented) for all operations.

                                                      func NewLockingRawFileSystem

                                                      func NewLockingRawFileSystem(fs RawFileSystem) RawFileSystem

                                                        Returns a Wrap

                                                        func NewRawFileSystem

                                                        func NewRawFileSystem(fs interface{}) RawFileSystem

                                                          NewRawFileSystem adds the methods missing for implementing a RawFileSystem to any object.

                                                          type ReadIn

                                                          type ReadIn struct {
                                                          	Fh        uint64
                                                          	Offset    uint64
                                                          	Size      uint32
                                                          	ReadFlags uint32
                                                          	LockOwner uint64
                                                          	Flags     uint32
                                                          	Padding   uint32

                                                          type ReadResult

                                                          type ReadResult interface {
                                                          	// Returns the raw bytes for the read, possibly using the
                                                          	// passed buffer. The buffer should be larger than the return
                                                          	// value from Size.
                                                          	Bytes(buf []byte) ([]byte, Status)
                                                          	// Size returns how many bytes this return value takes at most.
                                                          	Size() int
                                                          	// Done() is called after sending the data to the kernel.

                                                            The result of Read is an array of bytes, but for performance reasons, we can also return data as a file-descriptor/offset/size tuple. If the backing store for a file is another filesystem, this reduces the amount of copying between the kernel and the FUSE server. The ReadResult interface captures both cases.

                                                            func ReadResultData

                                                            func ReadResultData(b []byte) ReadResult

                                                            func ReadResultFd

                                                            func ReadResultFd(fd uintptr, off int64, sz int) ReadResult

                                                            type ReleaseIn

                                                            type ReleaseIn struct {
                                                            	Fh           uint64
                                                            	Flags        uint32
                                                            	ReleaseFlags uint32
                                                            	LockOwner    uint64

                                                            type Rename1In

                                                            type Rename1In struct {
                                                            	Newdir uint64

                                                            type RenameIn

                                                            type RenameIn struct {
                                                            	Newdir  uint64
                                                            	Flags   uint32
                                                            	Padding uint32

                                                            type Server

                                                            type Server struct {
                                                            	// contains filtered or unexported fields

                                                              Server contains the logic for reading from the FUSE device and translating it to RawFileSystem interface calls.

                                                              func NewServer

                                                              func NewServer(fs RawFileSystem, mountPoint string, opts *MountOptions) (*Server, error)

                                                                NewServer creates a server and attaches it to the given directory.

                                                                func (*Server) DebugData

                                                                func (ms *Server) DebugData() string

                                                                  DebugData returns internal status information for debugging purposes.

                                                                  func (*Server) DeleteNotify

                                                                  func (ms *Server) DeleteNotify(parent uint64, child uint64, name string) Status

                                                                    DeleteNotify notifies the kernel that an entry is removed from a directory. In many cases, this is equivalent to EntryNotify, except when the directory is in use, eg. as working directory of some process. You should not hold any FUSE filesystem locks, as that can lead to deadlock.

                                                                    func (*Server) EntryNotify

                                                                    func (ms *Server) EntryNotify(parent uint64, name string) Status

                                                                      EntryNotify should be used if the existence status of an entry within a directory changes. You should not hold any FUSE filesystem locks, as that can lead to deadlock.

                                                                      func (*Server) InodeNotify

                                                                      func (ms *Server) InodeNotify(node uint64, off int64, length int64) Status

                                                                        InodeNotify invalidates the information associated with the inode (ie. data cache, attributes, etc.)

                                                                        func (*Server) InodeNotifyStoreCache

                                                                        func (ms *Server) InodeNotifyStoreCache(node uint64, offset int64, data []byte) Status

                                                                          InodeNotifyStoreCache tells kernel to store data into inode's cache.

                                                                          This call is similar to InodeNotify, but instead of only invalidating a data region, it gives updated data directly to the kernel.

                                                                          func (*Server) InodeRetrieveCache

                                                                          func (ms *Server) InodeRetrieveCache(node uint64, offset int64, dest []byte) (n int, st Status)

                                                                            InodeRetrieveCache retrieves data from kernel's inode cache.

                                                                            InodeRetrieveCache asks kernel to return data from its cache for inode at [offset:offset+len(dest)) and waits for corresponding reply. If kernel cache has fewer consecutive data starting at offset, that fewer amount is returned. In particular if inode data at offset is not cached (0, OK) is returned.

                                                                            The kernel returns ENOENT if it does not currently have entry for this inode in its dentry cache.

                                                                            func (*Server) KernelSettings

                                                                            func (ms *Server) KernelSettings() *InitIn

                                                                              KernelSettings returns the Init message from the kernel, so filesystems can adapt to availability of features of the kernel driver. The message should not be altered.

                                                                              func (*Server) RecordLatencies

                                                                              func (ms *Server) RecordLatencies(l LatencyMap)

                                                                                RecordLatencies switches on collection of timing for each request coming from the kernel.P assing a nil argument switches off the

                                                                                func (*Server) Serve

                                                                                func (ms *Server) Serve()

                                                                                  Serve initiates the FUSE loop. Normally, callers should run Serve() and wait for it to exit, but tests will want to run this in a goroutine.

                                                                                  Each filesystem operation executes in a separate goroutine.

                                                                                  func (*Server) SetDebug

                                                                                  func (ms *Server) SetDebug(dbg bool)

                                                                                    SetDebug is deprecated. Use MountOptions.Debug instead.

                                                                                    func (*Server) Unmount

                                                                                    func (ms *Server) Unmount() (err error)

                                                                                      Unmount calls fusermount -u on the mount. This has the effect of shutting down the filesystem. After the Server is unmounted, it should be discarded.

                                                                                      func (*Server) WaitMount

                                                                                      func (ms *Server) WaitMount() error

                                                                                        WaitMount waits for the first request to be served. Use this to avoid racing between accessing the (empty or not yet mounted) mountpoint, and the OS trying to setup the user-space mount.

                                                                                        type SetAttrIn

                                                                                        type SetAttrIn struct {

                                                                                        type SetAttrInCommon

                                                                                        type SetAttrInCommon struct {
                                                                                        	Valid     uint32
                                                                                        	Padding   uint32
                                                                                        	Fh        uint64
                                                                                        	Size      uint64
                                                                                        	LockOwner uint64
                                                                                        	Atime     uint64
                                                                                        	Mtime     uint64
                                                                                        	Ctime     uint64
                                                                                        	Atimensec uint32
                                                                                        	Mtimensec uint32
                                                                                        	Ctimensec uint32
                                                                                        	Mode      uint32
                                                                                        	Unused4   uint32
                                                                                        	Unused5 uint32

                                                                                        func (*SetAttrInCommon) GetATime

                                                                                        func (s *SetAttrInCommon) GetATime() (time.Time, bool)

                                                                                        func (*SetAttrInCommon) GetCTime

                                                                                        func (s *SetAttrInCommon) GetCTime() (time.Time, bool)

                                                                                        func (*SetAttrInCommon) GetFh

                                                                                        func (s *SetAttrInCommon) GetFh() (uint64, bool)

                                                                                        func (*SetAttrInCommon) GetGID

                                                                                        func (s *SetAttrInCommon) GetGID() (uint32, bool)

                                                                                        func (*SetAttrInCommon) GetMTime

                                                                                        func (s *SetAttrInCommon) GetMTime() (time.Time, bool)

                                                                                        func (*SetAttrInCommon) GetMode

                                                                                        func (s *SetAttrInCommon) GetMode() (uint32, bool)

                                                                                        func (*SetAttrInCommon) GetSize

                                                                                        func (s *SetAttrInCommon) GetSize() (uint64, bool)

                                                                                        func (*SetAttrInCommon) GetUID

                                                                                        func (s *SetAttrInCommon) GetUID() (uint32, bool)

                                                                                        type SetXAttrIn

                                                                                        type SetXAttrIn struct {
                                                                                        	Size  uint32
                                                                                        	Flags uint32

                                                                                        type StatfsOut

                                                                                        type StatfsOut struct {
                                                                                        	Blocks  uint64
                                                                                        	Bfree   uint64
                                                                                        	Bavail  uint64
                                                                                        	Files   uint64
                                                                                        	Ffree   uint64
                                                                                        	Bsize   uint32
                                                                                        	NameLen uint32
                                                                                        	Frsize  uint32
                                                                                        	Padding uint32
                                                                                        	Spare   [6]uint32

                                                                                        func (*StatfsOut) FromStatfsT

                                                                                        func (s *StatfsOut) FromStatfsT(statfs *syscall.Statfs_t)

                                                                                        type Status

                                                                                        type Status int32

                                                                                          Status is the errno number that a FUSE call returns to the kernel.

                                                                                          func ToStatus

                                                                                          func ToStatus(err error) Status

                                                                                            ToStatus extracts an errno number from Go error objects. If it fails, it logs an error and returns ENOSYS.

                                                                                            func (Status) Ok

                                                                                            func (code Status) Ok() bool

                                                                                            func (Status) String

                                                                                            func (code Status) String() string

                                                                                            type WriteIn

                                                                                            type WriteIn struct {
                                                                                            	Fh         uint64
                                                                                            	Offset     uint64
                                                                                            	Size       uint32
                                                                                            	WriteFlags uint32
                                                                                            	LockOwner  uint64
                                                                                            	Flags      uint32
                                                                                            	Padding    uint32

                                                                                            type WriteOut

                                                                                            type WriteOut struct {
                                                                                            	Size    uint32
                                                                                            	Padding uint32


                                                                                            Path Synopsis
                                                                                            The nodefs package offers a high level API that resembles the kernel's idea of what an FS looks like.
                                                                                            The nodefs package offers a high level API that resembles the kernel's idea of what an FS looks like.
                                                                                            Package test holds the tests for Go-FUSE and is not for end-user consumption.
                                                                                            Package test holds the tests for Go-FUSE and is not for end-user consumption.