From patchwork Thu Apr 18 13:00:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wan, Kaike" X-Patchwork-Id: 10907257 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F7571515 for ; Thu, 18 Apr 2019 13:00:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5F9F028C9F for ; Thu, 18 Apr 2019 13:00:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5DFE528CA2; Thu, 18 Apr 2019 13:00:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 84FD028CA2 for ; Thu, 18 Apr 2019 13:00:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388253AbfDRNAi (ORCPT ); Thu, 18 Apr 2019 09:00:38 -0400 Received: from mga12.intel.com ([192.55.52.136]:44305 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726162AbfDRNAi (ORCPT ); Thu, 18 Apr 2019 09:00:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Apr 2019 06:00:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,366,1549958400"; d="scan'208";a="338648431" Received: from scymds02.sc.intel.com ([10.82.195.37]) by fmsmga006.fm.intel.com with ESMTP; 18 Apr 2019 06:00:37 -0700 Received: from scvm10.sc.intel.com (scvm10.sc.intel.com [10.82.195.27]) by scymds02.sc.intel.com with ESMTP id x3ID0bSb032183; Thu, 18 Apr 2019 06:00:37 -0700 Received: from scvm10.sc.intel.com (localhost [127.0.0.1]) by scvm10.sc.intel.com with ESMTP id x3ID0bHY011550; Thu, 18 Apr 2019 06:00:37 -0700 Subject: [PATCH] IB/hfi1: Failed to drain send queue when QP is put into error state To: stable@vger.kernel.org From: Kaike Wan Cc: linux-rdma@vger.kernel.org, stable-commits@vger.kernel.org Date: Thu, 18 Apr 2019 06:00:37 -0700 Message-ID: <20190418130033.11508.931.stgit@scvm10.sc.intel.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP commit 662d66466637862ef955f7f6e78a286d8cf0ebef upstream. When a QP is put into error state, all pending requests in the send work queue should be drained. The following sequence of events could lead to a failure, causing a request to hang: (1) The QP builds a packet and tries to send through SDMA engine. However, PIO engine is still busy. Consequently, this packet is put on the QP's tx list and the QP is put on the PIO waiting list. The field qp->s_flags is set with HFI1_S_WAIT_PIO_DRAIN; (2) The QP is put into error state by the user application and notify_error_qp() is called, which removes the QP from the PIO waiting list and the packet from the QP's tx list. In addition, qp->s_flags is cleared of RVT_S_ANY_WAIT_IO bits, which does not include HFI1_S_WAIT_PIO_DRAIN bit; (3) The hfi1_schdule_send() function is called to drain the QP's send queue. Subsequently, hfi1_do_send() is called. Since the flag bit HFI1_S_WAIT_PIO_DRAIN is set in qp->s_flags, hfi1_send_ok() fails. As a result, hfi1_do_send() bails out without draining any request from the send queue; (4) The PIO engine completes the sending and tries to wake up any QP on its waiting list. But the QP has been removed from the PIO waiting list and therefore is kept in sleep forever. The fix is to clear qp->s_flags of HFI1_S_ANY_WAIT_IO bits in step (2). HFI1_S_ANY_WAIT_IO includes RVT_S_ANY_WAIT_IO and HFI1_S_WAIT_PIO_DRAIN. [ Corrected commit message to match upstream ] Fixes: 2e2ba09e48b7 ("IB/rdmavt, IB/hfi1: Create device dependent s_flags") Cc: # 4.19.x+ Reviewed-by: Mike Marciniszyn Reviewed-by: Alex Estrin Signed-off-by: Kaike Wan Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/hfi1/qp.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/qp.c b/drivers/infiniband/hw/hfi1/qp.c index 9b1e84a..63c5ba6 100644 --- a/drivers/infiniband/hw/hfi1/qp.c +++ b/drivers/infiniband/hw/hfi1/qp.c @@ -784,7 +784,7 @@ void notify_error_qp(struct rvt_qp *qp) write_seqlock(lock); if (!list_empty(&priv->s_iowait.list) && !(qp->s_flags & RVT_S_BUSY)) { - qp->s_flags &= ~RVT_S_ANY_WAIT_IO; + qp->s_flags &= ~HFI1_S_ANY_WAIT_IO; list_del_init(&priv->s_iowait.list); priv->s_iowait.lock = NULL; rvt_put_qp(qp);