Return-Path: Received: from mail-io0-f196.google.com ([209.85.223.196]:35574 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbdAaSic (ORCPT ); Tue, 31 Jan 2017 13:38:32 -0500 Subject: [PATCH v2 2/7] xprtrdma: Handle stale connection rejection From: Chuck Lever To: anna.schumaker@netapp.com Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Tue, 31 Jan 2017 13:38:25 -0500 Message-ID: <20170131183825.5325.26488.stgit@manet.1015granger.net> In-Reply-To: <20170131183345.5325.47072.stgit@manet.1015granger.net> References: <20170131183345.5325.47072.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: A server rejects a connection attempt with STALE_CONNECTION when a client attempts to connect to a working remote service, but uses a QPN and GUID that corresponds to an old connection that was abandoned. This might occur after a client crashes and restarts. Fix rpcrdma_conn_upcall() to distinguish between a normal rejection and rejection of stale connection parameters. As an additional clean-up, remove the code that retries the connection attempt with different ORD/IRD values. Code audit of other ULP initiators shows no similar special case handling of initiator_depth or responder_resources. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/verbs.c | 66 ++++++++++++++----------------------------- 1 file changed, 21 insertions(+), 45 deletions(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 61d16c3..d1ee33f 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -54,6 +54,7 @@ #include #include #include /* try_module_get()/module_put() */ +#include #include "xprt_rdma.h" @@ -279,7 +280,14 @@ connstate = -ENETDOWN; goto connected; case RDMA_CM_EVENT_REJECTED: +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) + pr_info("rpcrdma: connection to %pIS:%u on %s rejected: %s\n", + sap, rpc_get_port(sap), ia->ri_device->name, + rdma_reject_msg(id, event->status)); +#endif connstate = -ECONNREFUSED; + if (event->status == IB_CM_REJ_STALE_CONN) + connstate = -EAGAIN; goto connected; case RDMA_CM_EVENT_DISCONNECTED: connstate = -ECONNABORTED; @@ -643,20 +651,21 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) int rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) { + struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt, + rx_ia); struct rdma_cm_id *id, *old; + struct sockaddr *sap; + unsigned int extras; int rc = 0; - int retry_count = 0; if (ep->rep_connected != 0) { - struct rpcrdma_xprt *xprt; retry: dprintk("RPC: %s: reconnecting...\n", __func__); rpcrdma_ep_disconnect(ep, ia); - xprt = container_of(ia, struct rpcrdma_xprt, rx_ia); - id = rpcrdma_create_id(xprt, ia, - (struct sockaddr *)&xprt->rx_data.addr); + sap = (struct sockaddr *)&r_xprt->rx_data.addr; + id = rpcrdma_create_id(r_xprt, ia, sap); if (IS_ERR(id)) { rc = -EHOSTUNREACH; goto out; @@ -711,51 +720,18 @@ static void rpcrdma_destroy_id(struct rdma_cm_id *id) } wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0); - - /* - * Check state. A non-peer reject indicates no listener - * (ECONNREFUSED), which may be a transient state. All - * others indicate a transport condition which has already - * undergone a best-effort. - */ - if (ep->rep_connected == -ECONNREFUSED && - ++retry_count <= RDMA_CONNECT_RETRY_MAX) { - dprintk("RPC: %s: non-peer_reject, retry\n", __func__); - goto retry; - } if (ep->rep_connected <= 0) { - /* Sometimes, the only way to reliably connect to remote - * CMs is to use same nonzero values for ORD and IRD. */ - if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 && - (ep->rep_remote_cma.responder_resources == 0 || - ep->rep_remote_cma.initiator_depth != - ep->rep_remote_cma.responder_resources)) { - if (ep->rep_remote_cma.responder_resources == 0) - ep->rep_remote_cma.responder_resources = 1; - ep->rep_remote_cma.initiator_depth = - ep->rep_remote_cma.responder_resources; + if (ep->rep_connected == -EAGAIN) goto retry; - } rc = ep->rep_connected; - } else { - struct rpcrdma_xprt *r_xprt; - unsigned int extras; - - dprintk("RPC: %s: connected\n", __func__); - - r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia); - extras = r_xprt->rx_buf.rb_bc_srv_max_requests; - - if (extras) { - rc = rpcrdma_ep_post_extra_recv(r_xprt, extras); - if (rc) { - pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n", - __func__, rc); - rc = 0; - } - } + goto out; } + dprintk("RPC: %s: connected\n", __func__); + extras = r_xprt->rx_buf.rb_bc_srv_max_requests; + if (extras) + rpcrdma_ep_post_extra_recv(r_xprt, extras); + out: if (rc) ep->rep_connected = rc;