From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 931BAC433ED for ; Mon, 20 Jul 2020 16:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6EF7E22CB1 for ; Mon, 20 Jul 2020 16:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261414; bh=BP5p3xvMdM2LHrjqsnq4+2Ifc19baMI8Cqa1u5Fe9vI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XaJ0EwiKCPkYggNetftvlqf48h4vtrXYVaZHVyo9YWqYnTJT4nxBg/OElgM3upplj 6DqTX8lFqV8PxzmkERob8MN7jclsBL+Yii9JBolHIiU4azehvd7rabB1F7jPV+rT0u mkJv6nHcn1fyk6xHQTcPICXtmHFc5cAZ/Qbr/wyQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387640AbgGTQKN (ORCPT ); Mon, 20 Jul 2020 12:10:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:48438 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387628AbgGTQKJ (ORCPT ); Mon, 20 Jul 2020 12:10:09 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8FA1320672; Mon, 20 Jul 2020 16:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261409; bh=BP5p3xvMdM2LHrjqsnq4+2Ifc19baMI8Cqa1u5Fe9vI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nd20TkyZau7HN2ZogBj8gCRXC6PB5EeKm2h/oS/P+4OPXow4IbBjIOug/UHtcQgvI gJUPYqx9Jg1iP+CsVO7KKt/2HsJmTp0LrmWbeLwPvASut7SLA5tfughV61EpR8w6Y+ bNKKOcmILxEETTomW50HW2xVP85vZK5uDBHEKdxk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Aloni , Chuck Lever , Anna Schumaker , Sasha Levin Subject: [PATCH 5.7 104/244] xprtrdma: Fix recursion into rpcrdma_xprt_disconnect() Date: Mon, 20 Jul 2020 17:36:15 +0200 Message-Id: <20200720152830.777325100@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152825.863040590@linuxfoundation.org> References: <20200720152825.863040590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chuck Lever [ Upstream commit 4cf44be6f1e86da302085bf3e1dc2c86f3cdaaaa ] Both Dan and I have observed two processes invoking rpcrdma_xprt_disconnect() concurrently. In my case: 1. The connect worker invokes rpcrdma_xprt_disconnect(), which drains the QP and waits for the final completion 2. This causes the newly posted Receive to flush and invoke xprt_force_disconnect() 3. xprt_force_disconnect() sets CLOSE_WAIT and wakes up the RPC task that is holding the transport lock 4. The RPC task invokes xprt_connect(), which calls ->ops->close 5. xprt_rdma_close() invokes rpcrdma_xprt_disconnect(), which tries to destroy the QP. Deadlock. To prevent xprt_force_disconnect() from waking anything, handle the clean up after a failed connection attempt in the xprt's sndtask. The retry loop is removed from rpcrdma_xprt_connect() to ensure that the newly allocated ep and id are properly released before a REJECTED connection attempt can be retried. Reported-by: Dan Aloni Fixes: e28ce90083f0 ("xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt") Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- net/sunrpc/xprtrdma/transport.c | 5 +++++ net/sunrpc/xprtrdma/verbs.c | 10 ++-------- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 659da37020a46..3b5fb1f57aeb7 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -249,6 +249,11 @@ xprt_rdma_connect_worker(struct work_struct *work) xprt->stat.connect_start; xprt_set_connected(xprt); rc = -EAGAIN; + } else { + /* Force a call to xprt_rdma_close to clean up */ + spin_lock(&xprt->transport_lock); + set_bit(XPRT_CLOSE_WAIT, &xprt->state); + spin_unlock(&xprt->transport_lock); } xprt_wake_pending_tasks(xprt, rc); } diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 4cb91dde849b9..00ee62579137b 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -288,7 +288,7 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event) sap, rdma_reject_msg(id, event->status)); ep->re_connect_status = -ECONNREFUSED; if (event->status == IB_CM_REJ_STALE_CONN) - ep->re_connect_status = -EAGAIN; + ep->re_connect_status = -ENOTCONN; goto disconnected; case RDMA_CM_EVENT_DISCONNECTED: ep->re_connect_status = -ECONNABORTED; @@ -519,8 +519,6 @@ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt) struct rpcrdma_ep *ep; int rc; -retry: - rpcrdma_xprt_disconnect(r_xprt); rc = rpcrdma_ep_create(r_xprt); if (rc) return rc; @@ -549,17 +547,13 @@ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt) wait_event_interruptible(ep->re_connect_wait, ep->re_connect_status != 0); if (ep->re_connect_status <= 0) { - if (ep->re_connect_status == -EAGAIN) - goto retry; rc = ep->re_connect_status; goto out; } rc = rpcrdma_reqs_setup(r_xprt); - if (rc) { - rpcrdma_xprt_disconnect(r_xprt); + if (rc) goto out; - } rpcrdma_mrs_create(r_xprt); out: -- 2.25.1