mount: Make fsync be a no-op rather than returning an error - fixes #1045

cmd/mount/file.go

@@ -144,3 +144,13 @@ func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenR
 	*/
 	return nil, errors.New("can't figure out how to open")
 }
+
+// Check interface satisfied
+var _ fusefs.NodeFsyncer = (*File)(nil)
+
+// Fsync the file
+//
+// Note that we don't do anything except return OK
+func (f *File) Fsync(ctx context.Context, req *fuse.FsyncRequest) error {
+	return nil
+}

cmd/mount/write_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 // Test writing a file with no write()'s to it
@@ -101,3 +102,18 @@ func TestWriteFileDoubleClose(t *testing.T) {
 
 	run.rm(t, "testdoubleclose")
 }
+
+// Test Fsync
+//
+// NB the code for this is in file.go rather than write.go
+func TestWriteFileFsync(t *testing.T) {
+	filepath := run.path("to be synced")
+	fd, err := os.Create(filepath)
+	require.NoError(t, err)
+	_, err = fd.Write([]byte("hello"))
+	require.NoError(t, err)
+	err = fd.Sync()
+	require.NoError(t, err)
+	err = fd.Close()
+	require.NoError(t, err)
+}