update a dir's mtime when we know that it's changed

fixes #219

Author: kahing

internal/dir.go

@@ -180,6 +180,7 @@ func (dh *DirHandle) listObjectsSlurp(prefix string) (resp *s3.ListObjectsOutput
 
 		if sealed || !*resp.IsTruncated {
 			d.dir.DirTime = time.Now()
+			d.Attributes.Mtime = d.findChildMaxTime()
 		}
 	}
 

internal/goofys.go

@@ -797,6 +797,7 @@ func (fs *Goofys) ReadDir(
 			// from S3 then update the cache time
 			if readFromS3 {
 				inode.dir.DirTime = time.Now()
+				inode.Attributes.Mtime = inode.findChildMaxTime()
 			}
 			break
 		}

internal/goofys_test.go

@@ -1864,3 +1864,40 @@ func (s *GoofysTest) TestWriteSeekWriteFuse(t *C) {
 
 	s.writeSeekWriteFuse(t, file, fh, "", "never", "minding")
 }
+
+func (s *GoofysTest) TestDirMtimeCreate(t *C) {
+	root := s.getRoot(t)
+
+	attr, _ := root.GetAttributes()
+	m1 := attr.Mtime
+	time.Sleep(time.Second)
+
+	_, _ = root.Create("foo")
+	attr2, _ := root.GetAttributes()
+	m2 := attr2.Mtime
+
+	t.Assert(m1.Before(m2), Equals, true)
+}
+
+func (s *GoofysTest) TestDirMtimeLs(t *C) {
+	root := s.getRoot(t)
+
+	attr, _ := root.GetAttributes()
+	m1 := attr.Mtime
+	time.Sleep(time.Second)
+
+	params := &s3.PutObjectInput{
+		Bucket: &s.fs.bucket,
+		Key:    aws.String("newfile"),
+		Body:   bytes.NewReader([]byte("foo")),
+	}
+	_, err := s.s3.PutObject(params)
+	t.Assert(err, IsNil)
+
+	s.readDirIntoCache(t, fuseops.RootInodeID)
+
+	attr2, _ := root.GetAttributes()
+	m2 := attr2.Mtime
+
+	t.Assert(m1.Before(m2), Equals, true)
+}

internal/handles.go

@@ -86,6 +86,10 @@ func (inode *Inode) FullName() *string {
 	}
 }
 
+func (inode *Inode) touch() {
+	inode.Attributes.Mtime = time.Now()
+}
+
 func (inode *Inode) InflateAttributes() (attr fuseops.InodeAttributes) {
 	attr = fuseops.InodeAttributes{
 		Size:   inode.Attributes.Size,
@@ -316,6 +320,8 @@ func (parent *Inode) Create(
 	fh.dirty = true
 	inode.fileHandles = 1
 
+	parent.touch()
+
 	return
 }
 
@@ -961,6 +967,18 @@ func (parent *Inode) insertSubTree(path string, obj *s3.Object, dirs map[*Inode]
 	}
 }
 
+func (parent *Inode) findChildMaxTime() time.Time {
+	maxTime := parent.Attributes.Mtime
+
+	for _, c := range parent.dir.Children {
+		if c.Attributes.Mtime.After(maxTime) {
+			maxTime = c.Attributes.Mtime
+		}
+	}
+
+	return maxTime
+}
+
 func (parent *Inode) readDirFromCache(offset fuseops.DirOffset) (en *DirHandleEntry, ok bool) {
 	parent.mu.Lock()
 	defer parent.mu.Unlock()