Added ReadSymlinkOp.

fuseops/convert.go

@@ -226,6 +226,13 @@ func Convert(
 		io = to
 		co = &to.commonOp
 
+	case *bazilfuse.ReadlinkRequest:
+		to := &ReadSymlinkOp{
+			Inode: InodeID(typed.Header.Node),
+		}
+		io = to
+		co = &to.commonOp
+
 	default:
 		to := &unknownOp{}
 		io = to

fuseops/ops.go

@@ -886,3 +886,23 @@ type unknownOp struct {
 func (o *unknownOp) toBazilfuseResponse() (bfResp interface{}) {
 	panic(fmt.Sprintf("Should never get here for unknown op: %s", o.ShortDesc()))
 }
+
+////////////////////////////////////////////////////////////////////////
+// Reading symlinks
+////////////////////////////////////////////////////////////////////////
+
+// Read the target of a symlink inode.
+type ReadSymlinkOp struct {
+	commonOp
+
+	// The symlink inode that we are reading.
+	Inode InodeID
+
+	// Set by the file system: the target of the symlink.
+	Target string
+}
+
+func (o *ReadSymlinkOp) toBazilfuseResponse() (bfResp interface{}) {
+	bfResp = o.Target
+	return
+}

fuseutil/file_system.go

@@ -57,6 +57,7 @@ type FileSystem interface {
 	SyncFile(*fuseops.SyncFileOp)
 	FlushFile(*fuseops.FlushFileOp)
 	ReleaseFileHandle(*fuseops.ReleaseFileHandleOp)
+	ReadSymlink(*fuseops.ReadSymlinkOp)
 }
 
 // Create a fuse.Server that handles ops by calling the associated FileSystem
@@ -185,5 +186,8 @@ func (s fileSystemServer) handleOp(op fuseops.Op) {
 
 	case *fuseops.ReleaseFileHandleOp:
 		s.fs.ReleaseFileHandle(typed)
+
+	case *fuseops.ReadSymlinkOp:
+		s.fs.ReadSymlink(typed)
 	}
 }

fuseutil/not_implemented_file_system.go

@@ -122,3 +122,8 @@ func (fs *NotImplementedFileSystem) ReleaseFileHandle(
 	op *fuseops.ReleaseFileHandleOp) {
 	op.Respond(fuse.ENOSYS)
 }
+
+func (fs *NotImplementedFileSystem) ReadSymlink(
+	op *fuseops.ReadSymlinkOp) {
+	op.Respond(fuse.ENOSYS)
+}

samples/memfs/fs.go

@@ -406,6 +406,9 @@ func (fs *memFS) CreateSymlink(
 	childID, child := fs.allocateInode(childAttrs)
 	defer child.mu.Unlock()
 
+	// Set up its target.
+	child.target = op.Target
+
 	// Add an entry in the parent.
 	parent.AddChild(childID, op.Name, fuseutil.DT_Link)
 
@@ -597,3 +600,21 @@ func (fs *memFS) WriteFile(
 
 	return
 }
+
+func (fs *memFS) ReadSymlink(
+	op *fuseops.ReadSymlinkOp) {
+	var err error
+	defer fuseutil.RespondToOp(op, &err)
+
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+
+	// Find the inode in question.
+	inode := fs.getInodeForReadingOrDie(op.Inode)
+	defer inode.mu.Unlock()
+
+	// Serve the request.
+	op.Target = inode.target
+
+	return
+}