} else if (req->r_dentry) {
                        path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
                                                    &pathbase, 0);
+                       if (IS_ERR(path))
+                               path = NULL;
                        spin_lock(&req->r_dentry->d_lock);
                        seq_printf(s, " #%llx/%.*s (%s)",
                                   ceph_ino(req->r_dentry->d_parent->d_inode),
                if (req->r_old_dentry) {
                        path = ceph_mdsc_build_path(req->r_old_dentry, &pathlen,
                                                    &pathbase, 0);
+                       if (IS_ERR(path))
+                               path = NULL;
                        spin_lock(&req->r_old_dentry->d_lock);
                        seq_printf(s, " #%llx/%.*s (%s)",
                           ceph_ino(req->r_old_dentry->d_parent->d_inode),