2 files changed, 13 insertions, 0 deletions
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 1b6467eb2..43fea1b1e 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1660,6 +1660,14 @@ void restoreMountNamespace()
 #endif
 }
 
+void unshareFilesystem()
+{
+#ifdef __linux__
+    if (unshare(CLONE_FS) != 0 && errno != EPERM)
+        throw SysError("unsharing filesystem state in download thread");
+#endif
+}
+
 void restoreProcessContext(bool restoreMounts)
 {
     restoreSignals();
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index bc96bfed1..4cc043a84 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -311,6 +311,11 @@ void saveMountNamespace();
    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();
+
 
 class ExecError : public Error
 {