From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Wise Subject: Re: [PATCH RFC iproute2-next 1/2] rdma: add 'link add/delete' commands Date: Wed, 28 Nov 2018 13:34:14 -0600 Message-ID: References: <7026be07534b14fd74e592c315523c57fde05a0a.1543422310.git.swise@opengridcomputing.com> <20181128182645.GJ4559@mtr-leonro.mtl.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Cc: dsahern@gmail.com, stephen@networkplumber.org, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, BMT@zurich.ibm.com To: Leon Romanovsky Return-path: Received: from opengridcomputing.com ([72.48.214.68]:36000 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725870AbeK2Ggx (ORCPT ); Thu, 29 Nov 2018 01:36:53 -0500 In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: ... >>> + rd_prepare_msg(rd, RDMA_NLDEV_CMD_NEWLINK, &seq, >>> + (NLM_F_REQUEST | NLM_F_ACK)); >>> + mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_DEV_NAME, name); >>> + mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_LINK_TYPE, type); >>> + mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_NDEV_NAME, dev); >>> + ret = rd_send_msg(rd); >>> + if (ret) >>> + return ret; >>> + >>> + ret = rd_recv_msg(rd, link_add_parse_cb, rd, seq); >>> + if (ret) >>> + perror(NULL); >> Why do you need rd_recv_msg()? I think that it is not needed, at least >> for rename, I didn't need it. >> https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/tree/rdma/dev.c#n244 > To get the response of if it was successfully added.  It provides the > errno value. If I don't do the rd_recv_msg, then adding the same name twice fails without any error notification.  Ditto for deleting a non-existent link.  So the rd_recv_msg() allows getting the failure reason (and detecting the failure).