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Commit 0a90487b authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
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xprtrdma: Handle stale connection rejection 



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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 18c0fb31

net/sunrpc/xprtrdma/verbs.c

+21 −45
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/sunrpc/svc_rdma.h>

#include <asm/bitops.h>

#include <linux/module.h> /* try_module_get()/module_put() */

#include <rdma/ib_cm.h>



#include "xprt_rdma.h"
@@ -279,7 +280,14 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event) 
		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 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) 
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;
@@ -711,50 +720,17 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) 
	}



	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;

		goto out;

	}



	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;

			}

		}

	}

	if (extras)

		rpcrdma_ep_post_extra_recv(r_xprt, extras);



out:

	if (rc)