Don't fool around with rpm __db.00* files

index 764ab72..a8360fe 100644
@@ -299,9 +299,6 @@ class RpmPkgsList(PkgsList):
             # bb.note(cmd)
             tmp_output = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True).strip()
 
-            rpm_db_locks = glob.glob('%s/var/lib/rpm/__db.*' % self.rootfs_dir)
-            for f in rpm_db_locks:
-                bb.utils.remove(f, True)
         except subprocess.CalledProcessError as e:
             bb.fatal("Cannot get the installed packages list. Command '%s' "
                      "returned %d:\n%s" % (cmd, e.returncode, e.output))

@@ -1101,7 +1098,6 @@ class RpmPM(PackageManager):
             output = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True).strip()
             bb.note(output)
             os.chmod(saved_dir, 0755)
-            self._unlock_rpm_db()
         except subprocess.CalledProcessError as e:
             bb.fatal("Invoke save_rpmpostinst failed. Command '%s' "
                      "returned %d:\n%s" % (cmd, e.returncode, e.output))

@@ -1117,14 +1113,12 @@ class RpmPM(PackageManager):
             self._invoke_smart('flag --set ignore-recommends %s' % i)
         self._invoke_smart('channel --add rpmsys type=rpm-sys -y')
 
-        self._unlock_rpm_db()
-
     '''
     The rpm db lock files were produced after invoking rpm to query on
     build system, and they caused the rpm on target didn't work, so we
     need to unlock the rpm db by removing the lock files.
     '''
-    def _unlock_rpm_db(self):
+    def unlock_rpm_db(self):
         # Remove rpm db lock files
         rpm_db_locks = glob.glob('%s/var/lib/rpm/__db.*' % self.target_rootfs)
         for f in rpm_db_locks:

index 0e6c8bc..3eac3c9 100644
@@ -50,6 +50,15 @@ class Rootfs(object):
     def _handle_intercept_failure(self, failed_script):
         pass
 
+    """
+    The _cleanup() method should be used to clean-up stuff that we don't really
+    want to end up on target. For example, in the case of RPM, the DB locks.
+    The method is called, once, at the end of create() method.
+    """
+    @abstractmethod
+    def _cleanup(self):
+        pass
+
     def _exec_shell_cmd(self, cmd):
         fakerootcmd = self.d.getVar('FAKEROOT', True)
         if fakerootcmd is not None:

@@ -117,6 +126,8 @@ class Rootfs(object):
 
         self._generate_kernel_module_deps()
 
+        self._cleanup()
+
     def _uninstall_uneeded(self):
         if base_contains("IMAGE_FEATURES", "package-management",
                          True, False, self.d):

@@ -358,6 +369,13 @@ class RpmRootfs(Rootfs):
         for pkg in registered_pkgs.split():
             self.pm.save_rpmpostinst(pkg)
 
+    def _cleanup(self):
+        # during the execution of postprocess commands, rpm is called several
+        # times to get the files installed, dependencies, etc. This creates the
+        # __db.00* (Berkeley DB files that hold locks, rpm specific environment
+        # settings, etc.), that should not get into the final rootfs
+        self.pm.unlock_rpm_db()
+
 
 class DpkgRootfs(Rootfs):
     def __init__(self, d, manifest_dir):

@@ -431,6 +449,9 @@ class DpkgRootfs(Rootfs):
     def _log_check(self):
         pass
 
+    def _cleanup(self):
+        pass
+
 
 class OpkgRootfs(Rootfs):
     def __init__(self, d, manifest_dir):

@@ -694,6 +715,10 @@ class OpkgRootfs(Rootfs):
     def _log_check(self):
         pass
 
+    def _cleanup(self):
+        pass
+
+
 def create_rootfs(d, manifest_dir=None):
     env_bkp = os.environ.copy()