util.{hh,cc}: Split out namespaces.{hh,cc}

Change-Id: I8fd3f3b50c15ede29d489066b4e8d99c2c4636a6

1 files changed, 20 insertions, 0 deletions

diff --git a/src/libutil/namespaces.hh b/src/libutil/namespaces.hh
index 0b7eeb66c..3a920e665 100644
--- a/src/libutil/namespaces.hh
+++ b/src/libutil/namespaces.hh
@@ -3,6 +3,26 @@
 
 namespace nix {
 
+/**
+ * Save the current mount namespace. Ignored if called more than
+ * once.
+ */
+void saveMountNamespace();
+
+/**
+ * Restore the mount namespace saved by saveMountNamespace(). Ignored
+ * if saveMountNamespace() was never called.
+ */
+void restoreMountNamespace();
+
+/**
+ * Cause this thread to not share any FS attributes with the main
+ * thread, because this causes setns() in restoreMountNamespace() to
+ * fail.
+ */
+void unshareFilesystem();
+
+
 #if __linux__
 
 bool userNamespacesSupported();