diff -r a858d3de0d32 -r fe9db58b0b2d mercurial/subrepo.py
--- a/mercurial/subrepo.py	Mon Jul 07 18:45:46 2014 +0900
+++ b/mercurial/subrepo.py	Fri Jun 20 00:21:19 2014 +0900
@@ -525,8 +525,14 @@
         self._initrepo(r, state[0], create)
 
     def storeclean(self, path):
+        lock = self._repo.lock()
+        try:
+            return self._storeclean(path)
+        finally:
+            lock.release()
+
+    def _storeclean(self, path):
         clean = True
-        lock = self._repo.lock()
         itercache = self._calcstorehash(path)
         try:
             for filehash in self._readstorehashcache(path):
@@ -543,7 +549,6 @@
                 clean = False
             except StopIteration:
                 pass
-        lock.release()
         return clean
 
     def _calcstorehash(self, remotepath):