On 11/28/2018 2:08 PM, Leon Romanovsky wrote: > On Wed, Nov 28, 2018 at 10:02:04PM +0200, Leon Romanovsky wrote: >> On Wed, Nov 28, 2018 at 01:34:14PM -0600, Steve Wise wrote: >>> ... >>> >>>>>> + 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). >>> >> Shouldn't extack provide such information as part of NLM_F_ACK flag? >> >> just shooting into the air, will take more close look tomorrow. > OK, it was easier than I thought. > > You are right, need both send and receive to get the reason. > > Can you prepare general function and update rename part too? > Something like send_receive(...) with dummy callback for receive path. > > Thanks Sure, I'll whip something up for the next version of the patch series...
