ceph: fix authentication races, auth_none oops

Call __validate_auth() under monc->mutex, and use helper for
initial hello so that the pending_auth flag is set.  This fixes
possible races in which we have an authentication request (hello
or otherwise) pending and send another one.  In particular, with
auth_none, we _never_ want to call ceph_build_auth() from
__validate_auth(), since the ->build_request() method is NULL.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 13 insertions, 16 deletions

diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
index 542276e60798..40d7d90bbed1 100644
--- a/fs/ceph/mon_client.c
+++ b/fs/ceph/mon_client.c
@@ -96,6 +96,18 @@ int ceph_monmap_contains(struct ceph_monmap *m, struct ceph_entity_addr *addr)
 }
 
 /*
+ * Send an auth request.
+ */
+static void __send_prepared_auth_request(struct ceph_mon_client *monc, int len)
+{
+        monc->pending_auth = 1;
+        monc->m_auth->front.iov_len = len;
+        monc->m_auth->hdr.front_len = cpu_to_le32(len);
+        ceph_msg_get(monc->m_auth);  /* keep our ref */
+        ceph_con_send(monc->con, monc->m_auth);
+}
+
+/*
  * Close monitor session, if any.
  */
 static void __close_session(struct ceph_mon_client *monc)
@@ -137,10 +149,7 @@ static int __open_session(struct ceph_mon_client *monc)
                 ret = ceph_auth_build_hello(monc->auth,
                                             monc->m_auth->front.iov_base,
                                             monc->m_auth->front_max);
-                monc->m_auth->front.iov_len = ret;
-                monc->m_auth->hdr.front_len = cpu_to_le32(ret);
-                ceph_msg_get(monc->m_auth);  /* keep our ref */
-                ceph_con_send(monc->con, monc->m_auth);
+                __send_prepared_auth_request(monc, ret);
         } else {
                 dout("open_session mon%d already open\n", monc->cur_mon);
         }
@@ -507,11 +516,9 @@ static void delayed_work(struct work_struct *work)
                 __open_session(monc);  /* continue hunting */
         } else {
                 ceph_con_keepalive(monc->con);
-                mutex_unlock(&monc->mutex);
 
                 __validate_auth(monc);
 
-                mutex_lock(&monc->mutex);
                 if (monc->auth->ops->is_authenticated(monc->auth))
                         __send_subscribe(monc);
         }
@@ -650,16 +657,6 @@ void ceph_monc_stop(struct ceph_mon_client *monc)
         kfree(monc->monmap);
 }
 
-static void __send_prepared_auth_request(struct ceph_mon_client *monc, int len)
-{
-        monc->pending_auth = 1;
-        monc->m_auth->front.iov_len = len;
-        monc->m_auth->hdr.front_len = cpu_to_le32(len);
-        ceph_msg_get(monc->m_auth);  /* keep our ref */
-        ceph_con_send(monc->con, monc->m_auth);
-}
-
-
 static void handle_auth_reply(struct ceph_mon_client *monc,
                               struct ceph_msg *msg)
 {