Mark some linux-only files as such.

Change-Id: I265108f96471b9b472c29c2d9fbbd1d4dd6b44d0

fuse/pathfs/syscall_test.go

+// +build linux
+
 package pathfs
 
 import (
@@ -8,7 +10,6 @@ import (
 )
 
 func TestSysUtimensat(t *testing.T) {
-
 	symlink := "/tmp/TestSysUtimensat"
 	os.Remove(symlink)
 	err := os.Symlink("/nonexisting/file", symlink)
@@ -24,6 +25,7 @@ func TestSysUtimensat(t *testing.T) {
 	ts[1].Nsec = 3333
 	ts[1].Sec = 4444
 
+	// Linux specific.
 	err = sysUtimensat(0, symlink, &ts, _AT_SYMLINK_NOFOLLOW)
 	if err != nil {
 		t.Fatal(err)

fuse/pathfs/xattr_test.go

+// +build linux
+
 package pathfs
 
 import (

fuse/test/loopback_linux_test.go

@@ -101,3 +101,20 @@ func TestFallocate(t *testing.T) {
 			fi.Size())
 	}
 }
+
+// Check that "." and ".." exists. syscall.Getdents is linux specific.
+func TestSpecialEntries(t *testing.T) {
+	tc := NewTestCase(t)
+	defer tc.Cleanup()
+
+	d, err := os.Open(tc.mnt)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	defer d.Close()
+	buf := make([]byte, 100)
+	n, err := syscall.Getdents(int(d.Fd()), buf)
+	if n == 0 {
+		t.Errorf("directory is empty, entries '.' and '..' are missing")
+	}
+}

fuse/test/loopback_test.go

@@ -925,23 +925,6 @@ func TestUmask(t *testing.T) {
 	}
 }
 
-// Check that "." and ".." exists
-func TestSpecialEntries(t *testing.T) {
-	tc := NewTestCase(t)
-	defer tc.Cleanup()
-
-	d, err := os.Open(tc.mnt)
-	if err != nil {
-		t.Fatalf("Open failed: %v", err)
-	}
-	defer d.Close()
-	buf := make([]byte, 100)
-	n, err := syscall.Getdents(int(d.Fd()), buf)
-	if n == 0 {
-		t.Errorf("directory is empty, entries '.' and '..' are missing")
-	}
-}
-
 // Check that chgrp(1) works
 func TestChgrp(t *testing.T) {
 	tc := NewTestCase(t)

fuse/test/xattr_test.go

+// +build linux
+
 package test
 
 import (
@@ -11,6 +13,8 @@ import (
 	"github.com/hanwen/go-fuse/fuse/nodefs"
 )
 
+// this file is linux-only, since it uses syscall.Getxattr.
+
 type xattrNode struct {
 	nodefs.Node
 }

fuse/test/xfs_test.go

+// +build linux
+
 package test
 
 import (