fuse: Add MountOptions.SingleThreaded.

fuse/api.go

@@ -57,9 +57,12 @@ type MountOptions struct {
 	// This may be useful for NFS.
 	RememberInodes bool
 
-	// The Name will show up on the output of the mount. Keep this string
+	// The name will show up on the output of the mount. Keep this string
 	// small.
 	Name string
+
+	// If set, wrap the file system in a single-threaded wrapper.
+	SingleThreaded bool
 }
 
 // RawFileSystem is an interface close to the FUSE wire protocol.

fuse/server.go

@@ -78,6 +78,9 @@ func (ms *Server) RecordLatencies(l LatencyMap) {
 	ms.latencies = l
 }
 
+// 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 (ms *Server) Unmount() (err error) {
 	if ms.mountPoint == "" {
 		return nil
@@ -112,6 +115,10 @@ func NewServer(fs RawFileSystem, mountPoint string, opts *MountOptions) (*Server
 		}
 	}
 	o := *opts
+	if o.SingleThreaded {
+		fs = NewLockingRawFileSystem(fs)
+	}
+
 	if o.Buffers == nil {
 		o.Buffers = defaultBufferPool
 	}

fuse/test/loopback_test.go

@@ -76,7 +76,6 @@ func NewTestCase(t *testing.T) *testCase {
 	pfs = pathfs.NewLoopbackFileSystem(me.orig)
 	pfs = pathfs.NewLockingFileSystem(pfs)
 
-	var rfs fuse.RawFileSystem
 	me.pathFs = pathfs.NewPathNodeFs(pfs, &pathfs.PathNodeFsOptions{
 		ClientInodes: true})
 	me.connector = nodefs.NewFileSystemConnector(me.pathFs,
@@ -85,10 +84,9 @@ func NewTestCase(t *testing.T) *testCase {
 			AttrTimeout:     testTtl,
 			NegativeTimeout: 0.0,
 		})
-	rfs = fuse.NewLockingRawFileSystem(me.connector.RawFS())
-
 	me.connector.SetDebug(fuse.VerboseTest())
-	me.state, err = fuse.NewServer(rfs, me.mnt, nil)
+	me.state, err = fuse.NewServer(
+		me.connector.RawFS(), me.mnt, &fuse.MountOptions{SingleThreaded: true})
 	if err != nil {
 		t.Fatal("NewServer:", err)
 	}