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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 AF04EC83004 for ; Tue, 28 Apr 2020 18:34:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C0B92085B for ; Tue, 28 Apr 2020 18:34:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098873; bh=btOVB0RLFuHhmGmdNI83TsUryhSAp6OgTUHhyiHbk98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wdzWr7hV0nSjYXdVCDeqE0F3P3mImGzkoXGleVd3T661bAf9Cimh3XVzzSXas85ik oRltmqiB9Q/J0/oNCwbvixNSb1BZwkQn7ZGhbgcMV0+cmjytebTm5NhT9xK5nln7jp LMvX00v/RhyQ+wQT5sUn5F2Yz12EtSPjoR5H/Ctg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730055AbgD1Sec (ORCPT ); Tue, 28 Apr 2020 14:34:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:51188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730137AbgD1Se1 (ORCPT ); Tue, 28 Apr 2020 14:34:27 -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 3B1E621707; Tue, 28 Apr 2020 18:34:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098866; bh=btOVB0RLFuHhmGmdNI83TsUryhSAp6OgTUHhyiHbk98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ROrD2kjzvo2P7Sryqhl4tknFicZ13YzWqqJN0PyqybKBxY2AEN8P7vQ0W5xN4QXdo AGs6zvMqm78eec6a1lM00zZPCYE8I14Mp4u6CgSIeRTzbxm3xMbPoujebU5IwCuQPN IjLNRlEAYZann0EQx0eqrR4rRf7vwRNFxNA8Dbk0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust , Chuck Lever Subject: [PATCH 5.6 122/167] SUNRPC: Fix backchannel RPC soft lockups Date: Tue, 28 Apr 2020 20:24:58 +0200 Message-Id: <20200428182240.699650773@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@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 commit 6221f1d9b63fed6260273e59a2b89ab30537a811 upstream. Currently, after the forward channel connection goes away, backchannel operations are causing soft lockups on the server because call_transmit_status's SOFTCONN logic ignores ENOTCONN. Such backchannel Calls are aggressively retried until the client reconnects. Backchannel Calls should use RPC_TASK_NOCONNECT rather than RPC_TASK_SOFTCONN. If there is no forward connection, the server is not capable of establishing a connection back to the client, thus that backchannel request should fail before the server attempts to send it. Commit 58255a4e3ce5 ("NFSD: NFSv4 callback client should use RPC_TASK_SOFTCONN") was merged several years before RPC_TASK_NOCONNECT was available. Because setup_callback_client() explicitly sets NOPING, the NFSv4.0 callback connection depends on the first callback RPC to initiate a connection to the client. Thus NFSv4.0 needs to continue to use RPC_TASK_SOFTCONN. Suggested-by: Trond Myklebust Signed-off-by: Chuck Lever Cc: # v4.20+ Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4callback.c | 4 +++- net/sunrpc/svc_xprt.c | 2 ++ net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 2 ++ net/sunrpc/xprtsock.c | 1 + 4 files changed, 8 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1312,6 +1312,7 @@ nfsd4_run_cb_work(struct work_struct *wo container_of(work, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; + int flags; if (cb->cb_need_restart) { cb->cb_need_restart = false; @@ -1340,7 +1341,8 @@ nfsd4_run_cb_work(struct work_struct *wo } cb->cb_msg.rpc_cred = clp->cl_cb_cred; - rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, + flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; + rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags, cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); } --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -1028,6 +1028,8 @@ static void svc_delete_xprt(struct svc_x dprintk("svc: svc_delete_xprt(%p)\n", xprt); xprt->xpt_ops->xpo_detach(xprt); + if (xprt->xpt_bc_xprt) + xprt->xpt_bc_xprt->ops->close(xprt->xpt_bc_xprt); spin_lock_bh(&serv->sv_lock); list_del_init(&xprt->xpt_list); --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -242,6 +242,8 @@ static void xprt_rdma_bc_close(struct rpc_xprt *xprt) { dprintk("svcrdma: %s: xprt %p\n", __func__, xprt); + + xprt_disconnect_done(xprt); xprt->cwnd = RPC_CWNDSHIFT; } --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2714,6 +2714,7 @@ static int bc_send_request(struct rpc_rq static void bc_close(struct rpc_xprt *xprt) { + xprt_disconnect_done(xprt); } /*