From patchwork Tue Feb 4 09:12:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krishnamraju Eraparaju X-Patchwork-Id: 11364223 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1DDE3112B for ; Tue, 4 Feb 2020 09:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F14842087E for ; Tue, 4 Feb 2020 09:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbgBDJMq (ORCPT ); Tue, 4 Feb 2020 04:12:46 -0500 Received: from stargate.chelsio.com ([12.32.117.8]:9961 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727040AbgBDJMq (ORCPT ); Tue, 4 Feb 2020 04:12:46 -0500 Received: from localhost (pvp1.blr.asicdesigners.com [10.193.80.26]) by stargate.chelsio.com (8.13.8/8.13.8) with ESMTP id 0149CY3O012734; Tue, 4 Feb 2020 01:12:36 -0800 From: Krishnamraju Eraparaju To: jgg@ziepe.ca, dledford@redhat.com Cc: linux-rdma@vger.kernel.org, bharat@chelsio.com, nirranjan@chelsio.com, krishna2@chelsio.com Subject: [PATCH for-rc] RDMA/iw_cxgb4: initiate CLOSE when entering TERM Date: Tue, 4 Feb 2020 14:42:30 +0530 Message-Id: <20200204091230.7210-1-krishna2@chelsio.com> X-Mailer: git-send-email 2.23.0.rc0 MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org - As per draft-hilland-iwarp-verbs-v1.0, sec 6.2.3, always initiate a CLOSE when entering into TERM state. - In c4iw_modify_qp(), disconnect operation should only be performed when the modify_qp call is invoked from ib_core. And all other internal modify_qp calls(invoked within iw_cxgb4) that needs 'disconnect' should call c4iw_ep_disconnect() explicitly after modify_qp. Otherwise, deadlocks like below can occur: Call Trace: schedule+0x2f/0xa0 schedule_preempt_disabled+0xa/0x10 __mutex_lock.isra.5+0x2d0/0x4a0 c4iw_ep_disconnect+0x39/0x430 => tries to reacquire ep lock again c4iw_modify_qp+0x468/0x10d0 rx_data+0x218/0x570 => acquires ep lock process_work+0x5f/0x70 process_one_work+0x1a7/0x3b0 worker_thread+0x30/0x390 kthread+0x112/0x130 ret_from_fork+0x35/0x40 Fixes: d2c33370ae73 ("RDMA/iw_cxgb4: Always disconnect when QP is transitioning to TERMINATE state") Signed-off-by: Krishnamraju Eraparaju --- drivers/infiniband/hw/cxgb4/cm.c | 4 ++++ drivers/infiniband/hw/cxgb4/qp.c | 4 ++-- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index ee1182f9b627..d69dece3b1d5 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -3036,6 +3036,10 @@ static int terminate(struct c4iw_dev *dev, struct sk_buff *skb) C4IW_QP_ATTR_NEXT_STATE, &attrs, 1); } + /* As per draft-hilland-iwarp-verbs-v1.0, sec 6.2.3, + * when entering the TERM state the RNIC MUST initiate a CLOSE. + */ + c4iw_ep_disconnect(ep, 1, GFP_KERNEL); c4iw_put_ep(&ep->com); } else pr_warn("TERM received tid %u no ep/qp\n", tid); diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c index bbcac539777a..89ac2f9ae6dd 100644 --- a/drivers/infiniband/hw/cxgb4/qp.c +++ b/drivers/infiniband/hw/cxgb4/qp.c @@ -1948,10 +1948,10 @@ int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp, qhp->attr.layer_etype = attrs->layer_etype; qhp->attr.ecode = attrs->ecode; ep = qhp->ep; - c4iw_get_ep(&ep->com); - disconnect = 1; if (!internal) { + c4iw_get_ep(&ep->com); terminate = 1; + disconnect = 1; } else { terminate = qhp->attr.send_term; ret = rdma_fini(rhp, qhp, ep);