fs: return correct file size of symlink

Signed-off-by: Kohei Tokunaga <[email protected]>

fs/layer/node.go

@@ -619,6 +619,9 @@ func (sf *statFile) updateStatUnlocked() ([]byte, error) {
 func entryToAttr(ino uint64, e metadata.Attr, out *fuse.Attr) fusefs.StableAttr {
 	out.Ino = ino
 	out.Size = uint64(e.Size)
+	if e.Mode&os.ModeSymlink != 0 {
+		out.Size = uint64(len(e.LinkName))
+	}
 	out.Blksize = blockSize
 	out.Blocks = out.Size / uint64(out.Blksize)
 	if out.Size%uint64(out.Blksize) > 0 {

fs/layer/testutil.go

@@ -501,6 +501,15 @@ func testExistence(t *testing.T, factory metadata.Store) {
 				hasExtraMode("test", os.ModeSticky),
 			},
 		},
+		{
+			name: "symlink_size",
+			in: []testutil.TarEntry{
+				testutil.Symlink("test", "target"),
+			},
+			want: []check{
+				hasSize("test", len("target")),
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -598,6 +607,22 @@ func hasFileDigest(filename string, digest string) check {
 	}
 }
 
+func hasSize(name string, size int) check {
+	return func(t *testing.T, root *node) {
+		_, n, err := getDirentAndNode(t, root, name)
+		if err != nil {
+			t.Fatalf("failed to get node %q: %v", name, err)
+		}
+		var ao fuse.AttrOut
+		if errno := n.Operations().(fusefs.NodeGetattrer).Getattr(context.Background(), nil, &ao); errno != 0 {
+			t.Fatalf("failed to get attributes of node %q: %v", name, errno)
+		}
+		if ao.Attr.Size != uint64(size) {
+			t.Fatalf("got size = %d, want %d", ao.Attr.Size, size)
+		}
+	}
+}
+
 func hasExtraMode(name string, mode os.FileMode) check {
 	return func(t *testing.T, root *node) {
 		_, n, err := getDirentAndNode(t, root, name)