Mount the new system as 'postinstall_file' in postinstall.
When mounting the new filesystem on /postinstall, we need to override
the file attributes from the new system (unknown to the current selinux
policies) with a consistent label that will be used only in the context
of postinstall. This patch passes an extra option to mount(2) in
Brillo and Android to achieve this.
Bug: 27177071
TEST=Deployed a postinstall script with `ls -laZ`, contents show "postinstall_file".
Change-Id: Ia43b45c92e4c4cd340a884818ac00f24a418f9e7
diff --git a/common/platform_constants.h b/common/platform_constants.h
index d1786ff..6eaa940 100644
--- a/common/platform_constants.h
+++ b/common/platform_constants.h
@@ -50,6 +50,10 @@
// The stateful directory used by update_engine.
extern const char kNonVolatileDirectory[];
+// Options passed to the filesystem when mounting the new partition during
+// postinstall.
+extern const char kPostinstallMountOptions[];
+
} // namespace constants
} // namespace chromeos_update_engine