Documentation

Overview

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 {
	fuse.RawFileSystem
	...
}

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.
fssrv.Serve()

// 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 github.com/hanwen/go-fuse/fuse/nodefs provides way to implement filesystems in terms of inodes. This resembles kernel's idea of what a filesystem looks like.

Package github.com/hanwen/go-fuse/fuse/pathfs 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.

Index

Constants

View Source
const (
	FUSE_ROOT_ID = 1

	FUSE_UNKNOWN_INO = 0xffffffff

	CUSE_UNRESTRICTED_IOCTL = (1 << 0)

	FUSE_LK_FLOCK = (1 << 0)

	FUSE_IOCTL_MAX_IOV = 256

	FUSE_POLL_SCHEDULE_NOTIFY = (1 << 0)

	CUSE_INIT_INFO_MAX = 4096

	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_LOCKOWNER = (1 << 9)
	FATTR_CTIME     = (1 << 10)
)
View Source
const (
	// OpenOut.Flags
	FOPEN_DIRECT_IO   = (1 << 0)
	FOPEN_KEEP_CACHE  = (1 << 1)
	FOPEN_NONSEEKABLE = (1 << 2)
)
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_READDIRPLUS_AUTO   = (1 << 14)
	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)
	CAP_NO_OPENDIR_SUPPORT = (1 << 24)
)

To be set in InitIn/InitOut.Flags.

View Source
const (
	FUSE_IOCTL_COMPAT       = (1 << 0)
	FUSE_IOCTL_UNRESTRICTED = (1 << 1)
	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)

Variables

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

Functions

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.

Types

type AccessIn

type AccessIn struct {
	InHeader
	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
	Owner
	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
	Attr
}

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 {
	Owner
	Pid uint32
}

type CreateIn

type CreateIn struct {
	InHeader
	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 {
	EntryOut
	OpenOut
}

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
	Attr
}

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 {
	InHeader
	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 {
	InHeader
	Fh        uint64
	Unused    uint32
	Padding   uint32
	LockOwner uint64
}

type ForgetIn

type ForgetIn struct {
	InHeader

	Nlookup uint64
}

type FsyncIn

type FsyncIn struct {
	InHeader
	Fh         uint64
	FsyncFlags uint32
	Padding    uint32
}

type GetAttrIn

type GetAttrIn struct {
	InHeader

	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 {
	InHeader
	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
	Context
	Padding uint32
}

type InitIn

type InitIn struct {
	InHeader

	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 {
	InHeader
	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 {
	InHeader
	Oldnodeid uint64
}

type LkIn

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

type LkOut

type LkOut struct {
	Lk FileLock
}

type MkdirIn

type MkdirIn struct {
	InHeader

	// 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 {
	InHeader

	// 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 {
	InHeader
	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 {
	InHeader
	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).
	Init(*Server)
}

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 {
	InHeader
	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.
	Done()
}

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 {
	InHeader
	Fh           uint64
	Flags        uint32
	ReleaseFlags uint32
	LockOwner    uint64
}

type Rename1In

type Rename1In struct {
	InHeader
	Newdir uint64
}

type RenameIn

type RenameIn struct {
	InHeader
	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 {
	SetAttrInCommon
}

type SetAttrInCommon

type SetAttrInCommon struct {
	InHeader

	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
	Owner
	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 {
	InHeader
	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 {
	InHeader
	Fh         uint64
	Offset     uint64
	Size       uint32
	WriteFlags uint32
	LockOwner  uint64
	Flags      uint32
	Padding    uint32
}

type WriteOut

type WriteOut struct {
	Size    uint32
	Padding uint32
}

Directories

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.