ceph: close out mds, osd connections before stopping auth

The auth module (part of the mon_client) is needed to free any
ceph_authorizer(s) used by the mds and osd connections.  Flush the msgr
workqueue before stopping monc to ensure that the destroy_authorizer
auth op is available when those connections are closed out.
Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/messenger.c

@@ -120,6 +120,12 @@ void ceph_msgr_exit(void)
 	destroy_workqueue(ceph_msgr_wq);
 }
 
+void ceph_msgr_flush()
+{
+	flush_workqueue(ceph_msgr_wq);
+}
+
+
 /*
  * socket callback functions
  */

fs/ceph/messenger.h

@@ -213,6 +213,7 @@ extern int ceph_parse_ips(const char *c, const char *end,
 
 extern int ceph_msgr_init(void);
 extern void ceph_msgr_exit(void);
+extern void ceph_msgr_flush(void);
 
 extern struct ceph_messenger *ceph_messenger_create(
 	struct ceph_entity_addr *myaddr);

fs/ceph/super.c

@@ -669,9 +669,17 @@ static void ceph_destroy_client(struct ceph_client *client)
 
 	/* unmount */
 	ceph_mdsc_stop(&client->mdsc);
-	ceph_monc_stop(&client->monc);
 	ceph_osdc_stop(&client->osdc);
 
+	/*
+	 * make sure mds and osd connections close out before destroying
+	 * the auth module, which is needed to free those connections'
+	 * ceph_authorizers.
+	 */
+	ceph_msgr_flush();
+
+	ceph_monc_stop(&client->monc);
+
 	ceph_adjust_min_caps(-client->min_caps);
 
 	ceph_debugfs_client_cleanup(client);