ceph: flush cap releases when the session is flushed

MDS expects the completed cap release prior to responding to the
session flush for cache drop.

Cc: stable@vger.kernel.org
Link: http://tracker.ceph.com/issues/38009
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index e163f58..27a245d 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3685,6 +3685,12 @@ static void handle_session(struct ceph_mds_session *session,
                break;
 
        case CEPH_SESSION_FLUSHMSG:
+               /* flush cap releases */
+               spin_lock(&session->s_cap_lock);
+               if (session->s_num_cap_releases)
+                       ceph_flush_cap_releases(mdsc, session);
+               spin_unlock(&session->s_cap_lock);
+
                send_flushmsg_ack(mdsc, session, seq);
                break;