overlay: fix check for rootless native diff

make sure "userxattr" is specified, otherwise the "user.overlay." xattrs are not treated specially and copied up as for the root case. Closes: #947 Signed-off-by: Giuseppe Scrivano <[email protected]>
containers · Jun 22, 2021 · 1e81ec1 · 1e81ec1
1 parent b83d218
commit 1e81ec1
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/drivers/overlay/check.go b/drivers/overlay/check.go
@@ -60,7 +60,12 @@ func doesSupportNativeDiff(d, mountOpts string) error {
 		return errors.Wrap(err, "failed to set opaque flag on middle layer")
 	}
 
-	opts := fmt.Sprintf("lowerdir=%s:%s,upperdir=%s,workdir=%s", path.Join(td, "l2"), path.Join(td, "l1"), path.Join(td, "l3"), path.Join(td, "work"))
+	mountFlags := "lowerdir=%s:%s,upperdir=%s,workdir=%s"
+	if unshare.IsRootless() {
+		mountFlags = mountFlags + ",userxattr"
+	}
+
+	opts := fmt.Sprintf(mountFlags, path.Join(td, "l2"), path.Join(td, "l1"), path.Join(td, "l3"), path.Join(td, "work"))
 	flags, data := mount.ParseOptions(mountOpts)
 	if data != "" {
 		opts = fmt.Sprintf("%s,%s", opts, data)