diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index f135660a2479d26cbb7affac7d93c2fae43c03e0..d555d27906198faccc9a5c8f801ca292316d69a5 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2044,12 +2044,24 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
 			if (mutex_trylock(&session->s_mutex) == 0) {
 				dout("inverting session/ino locks on %p\n",
 				     session);
+				session = ceph_get_mds_session(session);
 				spin_unlock(&ci->i_ceph_lock);
 				if (took_snap_rwsem) {
 					up_read(&mdsc->snap_rwsem);
 					took_snap_rwsem = 0;
 				}
-				mutex_lock(&session->s_mutex);
+				if (session) {
+					mutex_lock(&session->s_mutex);
+					ceph_put_mds_session(session);
+				} else {
+					/*
+					 * Because we take the reference while
+					 * holding the i_ceph_lock, it should
+					 * never be NULL. Throw a warning if it
+					 * ever is.
+					 */
+					WARN_ON_ONCE(true);
+				}
 				goto retry;
 			}
 		}