xprtrdma: Clear xprt->reestablish_timeout on close

Ensure that the re-establishment delay does not grow exponentially
on each good reconnect. This probably should have been part of
commit 675dd90 ("xprtrdma: Modernize ops->connect").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -1261,8 +1261,6 @@ void rpcrdma_complete_rqst(struct rpcrdma_rep *rep)
 	struct rpc_rqst *rqst = rep->rr_rqst;
 	int status;
 
-	xprt->reestablish_timeout = 0;
-
 	switch (rep->rr_proc) {
 	case rdma_msg:
 		status = rpcrdma_decode_msg(r_xprt, rep, rqst);
@@ -1321,6 +1319,12 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 	u32 credits;
 	__be32 *p;
 
+	/* Any data means we had a useful conversation, so
+	 * then we don't need to delay the next reconnect.
+	 */
+	if (xprt->reestablish_timeout)
+		xprt->reestablish_timeout = 0;
+
 	/* Fixed transport header fields */
 	xdr_init_decode(&rep->rr_stream, &rep->rr_hdrbuf,
 			rep->rr_hdrbuf.head[0].iov_base, NULL);

net/sunrpc/xprtrdma/transport.c

@@ -423,8 +423,6 @@ void xprt_rdma_close(struct rpc_xprt *xprt)
 
 	if (ep->rep_connected == -ENODEV)
 		return;
-	if (ep->rep_connected > 0)
-		xprt->reestablish_timeout = 0;
 	rpcrdma_ep_disconnect(ep, ia);
 
 	/* Prepare @xprt for the next connection by reinitializing
@@ -434,6 +432,7 @@ void xprt_rdma_close(struct rpc_xprt *xprt)
 	xprt->cwnd = RPC_CWNDSHIFT;
 
 out:
+	xprt->reestablish_timeout = 0;
 	++xprt->connect_cookie;
 	xprt_disconnect_done(xprt);
 }

net/sunrpc/xprtrdma/verbs.c

@@ -731,6 +731,8 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 	if (rc)
 		goto out;
 
+	if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
+		xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 	wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
 	if (ep->rep_connected <= 0) {
 		if (ep->rep_connected == -EAGAIN)