loopback: Utimens: enable Nsec precision for dates after 1970

syscall.NsecToTimespec is broken for dates before 1970 but works fine otherwise. Fix hanwen#100 as well and add a testcase.
rfjakob · Sep 25, 2016 · 16972fd · 16972fd
1 parent 41c29e1
commit 16972fd
Show file tree

Hide file tree

Showing 3 changed files with 50 additions and 5 deletions.
diff --git a/fuse/nodefs/files_linux.go b/fuse/nodefs/files_linux.go
@@ -32,14 +32,19 @@ func (f *loopbackFile) Utimens(a *time.Time, m *time.Time) fuse.Status {
 		ts[0].Nsec = _UTIME_OMIT
 	} else {
 		ts[0] = syscall.NsecToTimespec(a.UnixNano())
-		ts[0].Nsec = 0
+		if ts[0].Nsec < 0 {
+			// Go bug https://github.com/golang/go/issues/12777/
+			ts[0].Nsec = 0
+		}
 	}
 
 	if m == nil {
 		ts[1].Nsec = _UTIME_OMIT
 	} else {
-		ts[1] = syscall.NsecToTimespec(a.UnixNano())
-		ts[1].Nsec = 0
+		ts[1] = syscall.NsecToTimespec(m.UnixNano())
+		if ts[1].Nsec < 0 {
+			ts[1].Nsec = 0
+		}
 	}
 
 	f.lock.Lock()

diff --git a/fuse/pathfs/loopback_linux.go b/fuse/pathfs/loopback_linux.go
@@ -50,14 +50,19 @@ func (fs *loopbackFileSystem) Utimens(path string, a *time.Time, m *time.Time, c
 		ts[0].Nsec = _UTIME_OMIT
 	} else {
 		ts[0] = syscall.NsecToTimespec(a.UnixNano())
-		ts[0].Nsec = 0
+		if ts[0].Nsec < 0 {
+			// Go bug https://github.com/golang/go/issues/12777/
+			ts[0].Nsec = 0
+		}
 	}
 
 	if m == nil {
 		ts[1].Nsec = _UTIME_OMIT
 	} else {
 		ts[1] = syscall.NsecToTimespec(m.UnixNano())
-		ts[1].Nsec = 0
+		if ts[1].Nsec < 0 {
+			ts[1].Nsec = 0
+		}
 	}
 
 	err := sysUtimensat(0, fs.GetPath(path), &ts, _AT_SYMLINK_NOFOLLOW)

diff --git a/fuse/test/loopback_linux_test.go b/fuse/test/loopback_linux_test.go
@@ -70,6 +70,41 @@ func TestNegativeTime(t *testing.T) {
 	}
 }
 
+// Setting nanoseconds should work for dates after 1970
+func TestUtimesNano(t *testing.T) {
+	tc := NewTestCase(t)
+	defer tc.Cleanup()
+
+	path := tc.mountFile
+	err := ioutil.WriteFile(path, []byte("xyz"), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts := make([]syscall.Timespec, 2)
+	// atime
+	ts[0].Sec = 1
+	ts[0].Nsec = 2
+	// mtime
+	ts[1].Sec = 3
+	ts[1].Nsec = 4
+	err = syscall.UtimesNano(path, ts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var st syscall.Stat_t
+	err = syscall.Stat(path, &st)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if st.Atim != ts[0] {
+		t.Errorf("Wrong atime: %v, want: %v", st.Atim, ts[0])
+	}
+	if st.Mtim != ts[1] {
+		t.Errorf("Wrong mtime: %v, want: %v", st.Mtim, ts[1])
+	}
+}
+
 func clearStatfs(s *syscall.Statfs_t) {
 	empty := syscall.Statfs_t{}
 	s.Type = 0