From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935583AbdLRQUs (ORCPT ); Mon, 18 Dec 2017 11:20:48 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45912 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965131AbdLRQTI (ORCPT ); Mon, 18 Dec 2017 11:19:08 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chuck Lever , Anna Schumaker , Sasha Levin Subject: [PATCH 4.14 162/178] xprtrdma: Dont defer fencing an async RPCs chunks Date: Mon, 18 Dec 2017 16:49:58 +0100 Message-Id: <20171218152927.593718395@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171218152920.567991776@linuxfoundation.org> References: <20171218152920.567991776@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 8f66b1a529047a972cb9602a919c53a95f3d7a2b ] In current kernels, waiting in xprt_release appears to be safe to do. I had erroneously believed that for ASYNC RPCs, waiting of any kind in xprt_release->xprt_rdma_free would result in deadlock. I've done injection testing and consulted with Trond to confirm that waiting in the RPC release path is safe. For the very few times where RPC resources haven't yet been released earlier by the reply handler, it is safe to wait synchronously in xprt_rdma_free for invalidation rather than defering it to MR recovery. Note: When the QP is error state, posting a LocalInvalidate should flush and mark the MR as bad. There is no way the remote HCA can access that MR via a QP in error state, so it is effectively already inaccessible and thus safe for the Upper Layer to access. The next time the MR is used it should be recognized and cleaned up properly by frwr_op_map. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtrdma/transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -686,7 +686,7 @@ xprt_rdma_free(struct rpc_task *task) dprintk("RPC: %s: called on 0x%p\n", __func__, req->rl_reply); if (!list_empty(&req->rl_registered)) - ia->ri_ops->ro_unmap_safe(r_xprt, req, !RPC_IS_ASYNC(task)); + ia->ri_ops->ro_unmap_sync(r_xprt, &req->rl_registered); rpcrdma_unmap_sges(ia, req); rpcrdma_buffer_put(req); }