Add notification messages framework

connection.go

@@ -240,7 +240,19 @@ func (c *Connection) beginOp(
 	// should not record any state keyed on their ID.
 	//
 	// Cf. https://github.com/osxfuse/osxfuse/issues/208
-	if opCode != fusekernel.OpForget {
+
+	// Special case: For notify ops ,it is issued by the userspace filesystem to
+	// fuse kernel. The ops's kernel opCode is 0 in kernel' viewpoint or kernel not
+	// care whether what the iopcode is .But the ops have the notifycode  from 1
+	// to 6 now. For adapt the notfiy ops to the BeginOP ,we fake an opcode as
+	// notfiycode + 100. Now opcode range of ops from kernel including origin
+	// from userspace and just from kernel is < 100. The notify ops's opcode
+	// range is [101-106].
+	// Then we can process all ops consistently.
+	// Cf. func (c *Connection) SetNotifyContext(op interface{})
+	//                (context.Context, error) {
+
+	if opCode != fusekernel.OpForget && opCode < 100 {
 		var cancel func()
 		ctx, cancel = context.WithCancel(ctx)
 		c.recordCancelFunc(fuseID, cancel)
@@ -410,6 +422,38 @@ func (c *Connection) ReadOp() (ctx context.Context, op interface{}, err error) {
 	}
 }
 
+// The SetNotifyContext set context according with value of the notify op's
+// fuseops.Notify*Op.
+func (c *Connection) SetNotifyContext(op interface{}) (context.Context, error) {
+
+	outMsg := c.getOutMessage()
+
+	err := c.buildNotify(outMsg, op)
+	if err != nil {
+		return nil, err
+	}
+
+	ctx := context.Background()
+
+	switch op.(type) {
+	case *fuseops.NotifyInvalInodeOp:
+		ctx = c.beginOp(100+uint32(fusekernel.NotifyCodeInvalInode), 0)
+
+	case *fuseops.NotifyInvalEntryOp:
+		ctx = c.beginOp(100+uint32(fusekernel.NotifyCodeInvalEntry), 0)
+
+	case *fuseops.NotifyDeleteOp:
+		ctx = c.beginOp(100+uint32(fusekernel.NotifyCodeDelete), 0)
+
+	default:
+		panic(fmt.Sprintf("Unexpected op: %#v", op))
+	}
+
+	ctx = context.WithValue(ctx, contextKey, opState{nil, outMsg, op})
+	return ctx, nil
+
+}
+
 // Skip errors that happen as a matter of course, since they spook users.
 func (c *Connection) shouldLogError(
 	op interface{},
@@ -497,6 +541,29 @@ func (c *Connection) Reply(ctx context.Context, opErr error) {
 	}
 }
 
+// The NotifyKernel is same as Reply func of Connection.But the diff is
+// that the func only send to kernel.
+func (c *Connection) NotifyKernel(ctx context.Context) {
+
+	// we should get outmsg from context
+	var key interface{} = contextKey
+	foo := ctx.Value(key)
+	state, ok := foo.(opState)
+	if !ok {
+		panic(fmt.Sprintf("Reply called with invalid context: %#v", ctx))
+	}
+
+	outMsg := state.outMsg
+	defer c.putOutMessage(outMsg)
+
+	c.debugLogger.Println("dev fd is:unique:notifycode ", c.dev.Fd(), outMsg.OutHeader().Unique, outMsg.OutHeader().Error)
+	err := c.writeMessage(outMsg.Bytes())
+	if err != nil && c.errorLogger != nil {
+		c.errorLogger.Printf("writeMessage: %v %v", err, outMsg.Bytes())
+	}
+
+}
+
 // Close the connection. Must not be called until operations that were read
 // from the connection have been responded to.
 func (c *Connection) close() (err error) {

conversions.go

@@ -623,6 +623,59 @@ func (c *Connection) kernelResponse(
 	return
 }
 
+func (c *Connection) buildNotify(
+	m *buffer.OutMessage,
+	op interface{}) error {
+
+	h := m.OutHeader()
+	h.Unique = 0
+	// Create the appropriate output message
+	switch o := op.(type) {
+	case *fuseops.NotifyInvalInodeOp:
+		h.Error = fusekernel.NotifyCodeInvalInode
+		size := fusekernel.NotifyInvalInodeOutSize
+		out := (*fusekernel.NotifyInvalInodeOut)(m.Grow(size))
+		out.Ino = uint64(o.Ino)
+		out.Off = int64(o.Off)
+		out.Len = int64(o.Len)
+
+	case *fuseops.NotifyInvalEntryOp:
+		err := checkName(o.Name)
+		if err != nil {
+			return err
+		}
+		h.Error = fusekernel.NotifyCodeInvalEntry
+		size := fusekernel.NotifyInvalEntryOutSize
+		out := (*fusekernel.NotifyInvalEntryOut)(m.Grow(size))
+		out.Parent = uint64(o.Parent)
+		out.Namelen = uint32(len(o.Name))
+		m.Append([]byte(o.Name))
+		b := []byte{'\x00'}
+		m.Append(b)
+
+	case *fuseops.NotifyDeleteOp:
+		err := checkName(o.Name)
+		if err != nil {
+			return err
+		}
+		h.Error = fusekernel.NotifyCodeDelete
+		size := fusekernel.NotifyDeleteOutSize
+		out := (*fusekernel.NotifyDeleteOut)(m.Grow(size))
+		out.Parent = uint64(o.Parent)
+		out.Child = uint64(o.Child)
+		out.Namelen = uint32(len(o.Name))
+		m.Append([]byte(o.Name))
+		b := []byte{'\x00'}
+		m.Append(b)
+
+	default:
+		return errors.New("unexpectedop")
+	}
+	h.Len = uint32(m.Len())
+
+	return nil
+}
+
 // Like kernelResponse, but assumes the user replied with a nil error to the
 // op.
 func (c *Connection) kernelResponseForOp(
@@ -922,3 +975,11 @@ func writeXattrSize(m *buffer.OutMessage, size uint32) {
 	out := (*fusekernel.GetxattrOut)(m.Grow(int(unsafe.Sizeof(fusekernel.GetxattrOut{}))))
 	out.Size = size
 }
+func checkName(name string) error {
+	const maxUint32 = ^uint32(0)
+	if uint64(len(name)) > uint64(maxUint32) {
+		// very unlikely, but we don't want to silently truncate
+		return syscall.ENAMETOOLONG
+	}
+	return nil
+}

fuseops/ops.go

@@ -865,3 +865,62 @@ type SetXattrOp struct {
 	// simply replace the value if the attribute exists.
 	Flags uint32
 }
+
+// Notify IO readiness event
+type NotifyPollOp struct {
+}
+
+// Notify to invalidate cache for an inode.
+// Added in FUSE protocol version 7.12. If the kernel does not support this
+// (or a newer) version, the op will return -ENOSYS and do nothing
+type NotifyInvalInodeOp struct {
+	// inode to invalidatej
+	Ino InodeID
+
+	// the offset in the inode where to start invalidating or negative to invalidate attributes only
+	Off int64
+
+	// the amount of cache to invalidate or 0 for all
+	Len int64
+}
+
+// Notify to invalidate parent attributes and the dentry matching parent/name
+// Added in FUSE protocol version 7.12. If the kernel does not support this
+// (or a newer) version, the op will return -ENOSYS and do nothing
+type NotifyInvalEntryOp struct {
+	// the inode number
+	Parent InodeID
+
+	// the child entry file name
+	Name string
+}
+
+// Store data to the kernel buffers
+// Cf:http://libfuse.github.io/doxygen/fuse__lowlevel_8h.html#a9cb974af9745294ff446d11cba2422f1
+type NotifyStoreOp struct {
+}
+
+// Retrieve data from the kernel buffers
+type NotifyRetrieveOp struct {
+}
+
+// This op behaves like NotifyInvalEntryOp with the following additional
+// effect (at least as of Linux kernel 4.8):
+
+// If the provided child inode matches the inode that is currently
+// associated with the cached dentry, and if there are any inotify
+// watches registered for the dentry, then the watchers are informed
+// that the dentry has been deleted.
+// Added in FUSE protocol version 7.18. If the kernel does not
+// support this (or a newer) version, op will return -ENOSYS and do nothing.
+
+type NotifyDeleteOp struct {
+	// the inode number
+	Parent InodeID
+
+	// the child entry's inode
+	Child InodeID
+
+	// the child entry file name
+	Name string
+}

fuseutil/file_system.go

@@ -90,6 +90,8 @@ func NewFileSystemServer(fs FileSystem) fuse.Server {
 type fileSystemServer struct {
 	fs          FileSystem
 	opsInFlight sync.WaitGroup
+	//use set/get to use mfs not Mfs
+	Mfs *fuse.MountedFileSystem
 }
 
 func (s *fileSystemServer) ServeOps(c *fuse.Connection) {
@@ -123,6 +125,59 @@ func (s *fileSystemServer) ServeOps(c *fuse.Connection) {
 	}
 }
 
+func (s *fileSystemServer) InvalidateEntry(parent fuseops.InodeID, name string) error {
+	c := s.GetMfs().Conn.(*fuse.Connection)
+
+	op := &fuseops.NotifyInvalEntryOp{
+		Parent: fuseops.InodeID(parent),
+		Name:   string(name),
+	}
+	ctx, _ := c.SetNotifyContext(op)
+	s.opsInFlight.Add(1)
+	go func(ctx context.Context) {
+		defer s.opsInFlight.Done()
+		c.NotifyKernel(ctx)
+	}(ctx)
+	return nil
+}
+func (s *fileSystemServer) NotifyDelete(
+	parent fuseops.InodeID,
+	child fuseops.InodeID,
+	name string) error {
+	c := s.GetMfs().Conn.(*fuse.Connection)
+	op := &fuseops.NotifyDeleteOp{
+		Parent: fuseops.InodeID(parent),
+		Child:  fuseops.InodeID(child),
+		Name:   string(name),
+	}
+	ctx, _ := c.SetNotifyContext(op)
+	s.opsInFlight.Add(1)
+	go func(ctx context.Context) {
+		defer s.opsInFlight.Done()
+		c.NotifyKernel(ctx)
+	}(ctx)
+	return nil
+
+}
+func (s *fileSystemServer) InvalidateInode(
+	ino fuseops.InodeID,
+	off int64,
+	len int64) error {
+	c := s.GetMfs().Conn.(*fuse.Connection)
+	op := &fuseops.NotifyInvalInodeOp{
+		Ino: fuseops.InodeID(ino),
+		Off: off,
+		Len: len,
+	}
+	ctx, _ := c.SetNotifyContext(op)
+	s.opsInFlight.Add(1)
+	go func(ctx context.Context) {
+		defer s.opsInFlight.Done()
+		c.NotifyKernel(ctx)
+	}(ctx)
+	return nil
+
+}
 func (s *fileSystemServer) handleOp(
 	c *fuse.Connection,
 	ctx context.Context,
@@ -219,3 +274,12 @@ func (s *fileSystemServer) handleOp(
 
 	c.Reply(ctx, err)
 }
+
+func (s *fileSystemServer) GetMfs() *fuse.MountedFileSystem {
+	return s.Mfs
+
+}
+func (s *fileSystemServer) SetMfs(mfs *fuse.MountedFileSystem) {
+	s.Mfs = mfs
+
+}

internal/fusekernel/fuse_kernel.go

@@ -756,6 +756,9 @@ const (
 	NotifyCodePoll       int32 = 1
 	NotifyCodeInvalInode int32 = 2
 	NotifyCodeInvalEntry int32 = 3
+	NotifyCodeStore      int32 = 4
+	NotifyCodeRetrieve   int32 = 5
+	NotifyCodeDelete     int32 = 6
 )
 
 type NotifyInvalInodeOut struct {
@@ -764,8 +767,46 @@ type NotifyInvalInodeOut struct {
 	Len int64
 }
 
+const NotifyInvalInodeOutSize = int(unsafe.Sizeof(NotifyInvalInodeOut{}))
+
 type NotifyInvalEntryOut struct {
 	Parent  uint64
 	Namelen uint32
 	padding uint32
 }
+
+const NotifyInvalEntryOutSize = int(unsafe.Sizeof(NotifyInvalEntryOut{}))
+
+type NotifyDeleteOut struct {
+	Parent  uint64
+	Child   uint64
+	Namelen uint32
+	padding uint32
+}
+
+const NotifyDeleteOutSize = int(unsafe.Sizeof(NotifyDeleteOut{}))
+
+type NotifyStoreOut struct {
+	Nodeid  uint64
+	Offset  uint64
+	Size    uint32
+	padding uint32
+}
+
+type NotifyRetrieveOut struct {
+	NotifyUnique uint64
+	Nodeid       uint64
+	Offset       uint64
+	Size         uint32
+	padding      uint32
+}
+
+/* Matches the size of fuse_write_in */
+type NotifyRetrieveIn struct {
+	Dummy1 uint64
+	Offset uint64
+	Size   uint32
+	Dummy2 uint32
+	Dummy3 uint64
+	Dummy4 uint64
+}

mount.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"github.com/jacobsa/fuse/fuseops"
 )
 
 // Server is an interface for any type that knows how to serve ops read from a
@@ -27,6 +28,11 @@ type Server interface {
 	// until all operations have been responded to. Must not be called more than
 	// once.
 	ServeOps(*Connection)
+	InvalidateEntry(fuseops.InodeID, string) error
+	InvalidateInode(fuseops.InodeID, int64, int64) error
+	NotifyDelete(fuseops.InodeID, fuseops.InodeID, string) error
+	SetMfs(*MountedFileSystem)
+	GetMfs() *MountedFileSystem
 }
 
 // Mount attempts to mount a file system on the given directory, using the
@@ -84,7 +90,10 @@ func Mount(
 		return
 	}
 
-	// Serve the connection in the background. When done, set the join status.
+	mfs.Conn = connection
+	server.SetMfs(mfs)
+
+	// Serve the connection in the background. When done, set the join status
 	go func() {
 		server.ServeOps(connection)
 		mfs.joinStatus = connection.close()