Merge tag 'nfs-rdma-for-5.5-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFSoRDMA Client Updates for Linux 5.5

New Features:
- New tracepoints for congestion control and Local Invalidate WRs

Bugfixes and Cleanups:
- Eliminate log noise in call_reserveresult
- Fix unstable connections after a reconnect
- Clean up some code duplication
- Close race between waking a sender and posting a receive
- Fix MR list corruption, and clean up MR usage
- Remove unused rpcrdma_sendctx fields
- Try to avoid DMA mapping pages if it is too costly
- Wake pending tasks if connection fails
- Replace some dprintk()s with tracepoints

include/trace/events/rpcrdma.h

···
 				),					\
 				TP_ARGS(r_xprt))
 
+DECLARE_EVENT_CLASS(xprtrdma_connect_class,
+	TP_PROTO(
+		const struct rpcrdma_xprt *r_xprt,
+		int rc
+	),
+
+	TP_ARGS(r_xprt, rc),
+
+	TP_STRUCT__entry(
+		__field(const void *, r_xprt)
+		__field(int, rc)
+		__field(int, connect_status)
+		__string(addr, rpcrdma_addrstr(r_xprt))
+		__string(port, rpcrdma_portstr(r_xprt))
+	),
+
+	TP_fast_assign(
+		__entry->r_xprt = r_xprt;
+		__entry->rc = rc;
+		__entry->connect_status = r_xprt->rx_ep.rep_connected;
+		__assign_str(addr, rpcrdma_addrstr(r_xprt));
+		__assign_str(port, rpcrdma_portstr(r_xprt));
+	),
+
+	TP_printk("peer=[%s]:%s r_xprt=%p: rc=%d connect status=%d",
+		__get_str(addr), __get_str(port), __entry->r_xprt,
+		__entry->rc, __entry->connect_status
+	)
+);
+
+#define DEFINE_CONN_EVENT(name)						\
+		DEFINE_EVENT(xprtrdma_connect_class, xprtrdma_##name,	\
+				TP_PROTO(				\
+					const struct rpcrdma_xprt *r_xprt, \
+					int rc				\
+				),					\
+				TP_ARGS(r_xprt, rc))
+
 DECLARE_EVENT_CLASS(xprtrdma_rdch_event,
 	TP_PROTO(
 		const struct rpc_task *task,
···
 	)
 );
 
-TRACE_EVENT(xprtrdma_disconnect,
+TRACE_EVENT(xprtrdma_inline_thresh,
 	TP_PROTO(
-		const struct rpcrdma_xprt *r_xprt,
-		int status
+		const struct rpcrdma_xprt *r_xprt
 	),
 
-	TP_ARGS(r_xprt, status),
+	TP_ARGS(r_xprt),
 
 	TP_STRUCT__entry(
 		__field(const void *, r_xprt)
-		__field(int, status)
-		__field(int, connected)
+		__field(unsigned int, inline_send)
+		__field(unsigned int, inline_recv)
+		__field(unsigned int, max_send)
+		__field(unsigned int, max_recv)
+		__string(addr, rpcrdma_addrstr(r_xprt))
+		__string(port, rpcrdma_portstr(r_xprt))
+	),
+
+	TP_fast_assign(
+		const struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+
+		__entry->r_xprt = r_xprt;
+		__entry->inline_send = ep->rep_inline_send;
+		__entry->inline_recv = ep->rep_inline_recv;
+		__entry->max_send = ep->rep_max_inline_send;
+		__entry->max_recv = ep->rep_max_inline_recv;
+		__assign_str(addr, rpcrdma_addrstr(r_xprt));
+		__assign_str(port, rpcrdma_portstr(r_xprt));
+	),
+
+	TP_printk("peer=[%s]:%s r_xprt=%p neg send/recv=%u/%u, calc send/recv=%u/%u",
+		__get_str(addr), __get_str(port), __entry->r_xprt,
+		__entry->inline_send, __entry->inline_recv,
+		__entry->max_send, __entry->max_recv
+	)
+);
+
+DEFINE_CONN_EVENT(connect);
+DEFINE_CONN_EVENT(disconnect);
+
+DEFINE_RXPRT_EVENT(xprtrdma_create);
+DEFINE_RXPRT_EVENT(xprtrdma_op_destroy);
+DEFINE_RXPRT_EVENT(xprtrdma_remove);
+DEFINE_RXPRT_EVENT(xprtrdma_reinsert);
+DEFINE_RXPRT_EVENT(xprtrdma_op_inject_dsc);
+DEFINE_RXPRT_EVENT(xprtrdma_op_close);
+DEFINE_RXPRT_EVENT(xprtrdma_op_setport);
+
+TRACE_EVENT(xprtrdma_op_connect,
+	TP_PROTO(
+		const struct rpcrdma_xprt *r_xprt,
+		unsigned long delay
+	),
+
+	TP_ARGS(r_xprt, delay),
+
+	TP_STRUCT__entry(
+		__field(const void *, r_xprt)
+		__field(unsigned long, delay)
 		__string(addr, rpcrdma_addrstr(r_xprt))
 		__string(port, rpcrdma_portstr(r_xprt))
 	),
 
 	TP_fast_assign(
 		__entry->r_xprt = r_xprt;
-		__entry->status = status;
-		__entry->connected = r_xprt->rx_ep.rep_connected;
+		__entry->delay = delay;
 		__assign_str(addr, rpcrdma_addrstr(r_xprt));
 		__assign_str(port, rpcrdma_portstr(r_xprt));
 	),
 
-	TP_printk("peer=[%s]:%s r_xprt=%p: status=%d %sconnected",
-		__get_str(addr), __get_str(port),
-		__entry->r_xprt, __entry->status,
-		__entry->connected == 1 ? "still " : "dis"
+	TP_printk("peer=[%s]:%s r_xprt=%p delay=%lu",
+		__get_str(addr), __get_str(port), __entry->r_xprt,
+		__entry->delay
 	)
 );
 
-DEFINE_RXPRT_EVENT(xprtrdma_conn_start);
-DEFINE_RXPRT_EVENT(xprtrdma_conn_tout);
-DEFINE_RXPRT_EVENT(xprtrdma_create);
-DEFINE_RXPRT_EVENT(xprtrdma_op_destroy);
-DEFINE_RXPRT_EVENT(xprtrdma_remove);
-DEFINE_RXPRT_EVENT(xprtrdma_reinsert);
-DEFINE_RXPRT_EVENT(xprtrdma_reconnect);
-DEFINE_RXPRT_EVENT(xprtrdma_op_inject_dsc);
-DEFINE_RXPRT_EVENT(xprtrdma_op_close);
-DEFINE_RXPRT_EVENT(xprtrdma_op_connect);
 
 TRACE_EVENT(xprtrdma_op_set_cto,
 	TP_PROTO(
···
 DEFINE_WRCH_EVENT(reply);
 
 TRACE_DEFINE_ENUM(rpcrdma_noch);
+TRACE_DEFINE_ENUM(rpcrdma_noch_pullup);
+TRACE_DEFINE_ENUM(rpcrdma_noch_mapped);
 TRACE_DEFINE_ENUM(rpcrdma_readch);
 TRACE_DEFINE_ENUM(rpcrdma_areadch);
 TRACE_DEFINE_ENUM(rpcrdma_writech);
···
 #define xprtrdma_show_chunktype(x)					\
 		__print_symbolic(x,					\
 				{ rpcrdma_noch, "inline" },		\
+				{ rpcrdma_noch_pullup, "pullup" },	\
+				{ rpcrdma_noch_mapped, "mapped" },	\
 				{ rpcrdma_readch, "read list" },	\
 				{ rpcrdma_areadch, "*read list" },	\
 				{ rpcrdma_writech, "write list" },	\
···
 		__entry->client_id = rqst->rq_task->tk_client ?
 				     rqst->rq_task->tk_client->cl_clid : -1;
 		__entry->req = req;
-		__entry->num_sge = req->rl_sendctx->sc_wr.num_sge;
-		__entry->signaled = req->rl_sendctx->sc_wr.send_flags &
-				    IB_SEND_SIGNALED;
+		__entry->num_sge = req->rl_wr.num_sge;
+		__entry->signaled = req->rl_wr.send_flags & IB_SEND_SIGNALED;
 		__entry->status = status;
 	),
 
···
 	TP_printk("peer=[%s]:%s r_xprt=%p: %u new recvs, %d active (rc %d)",
 		__get_str(addr), __get_str(port), __entry->r_xprt,
 		__entry->count, __entry->posted, __entry->status
+	)
+);
+
+TRACE_EVENT(xprtrdma_post_linv,
+	TP_PROTO(
+		const struct rpcrdma_req *req,
+		int status
+	),
+
+	TP_ARGS(req, status),
+
+	TP_STRUCT__entry(
+		__field(const void *, req)
+		__field(int, status)
+		__field(u32, xid)
+	),
+
+	TP_fast_assign(
+		__entry->req = req;
+		__entry->status = status;
+		__entry->xid = be32_to_cpu(req->rl_slot.rq_xid);
+	),
+
+	TP_printk("req=%p xid=0x%08x status=%d",
+		__entry->req, __entry->xid, __entry->status
 	)
 );
 
···
 TRACE_EVENT(xprtrdma_fixup,
 	TP_PROTO(
 		const struct rpc_rqst *rqst,
-		int len,
-		int hdrlen
+		unsigned long fixup
 	),
 
-	TP_ARGS(rqst, len, hdrlen),
+	TP_ARGS(rqst, fixup),
 
 	TP_STRUCT__entry(
 		__field(unsigned int, task_id)
 		__field(unsigned int, client_id)
-		__field(const void *, base)
-		__field(int, len)
-		__field(int, hdrlen)
+		__field(unsigned long, fixup)
+		__field(size_t, headlen)
+		__field(unsigned int, pagelen)
+		__field(size_t, taillen)
 	),
 
 	TP_fast_assign(
 		__entry->task_id = rqst->rq_task->tk_pid;
 		__entry->client_id = rqst->rq_task->tk_client->cl_clid;
-		__entry->base = rqst->rq_rcv_buf.head[0].iov_base;
-		__entry->len = len;
-		__entry->hdrlen = hdrlen;
+		__entry->fixup = fixup;
+		__entry->headlen = rqst->rq_rcv_buf.head[0].iov_len;
+		__entry->pagelen = rqst->rq_rcv_buf.page_len;
+		__entry->taillen = rqst->rq_rcv_buf.tail[0].iov_len;
 	),
 
-	TP_printk("task:%u@%u base=%p len=%d hdrlen=%d",
-		__entry->task_id, __entry->client_id,
-		__entry->base, __entry->len, __entry->hdrlen
-	)
-);
-
-TRACE_EVENT(xprtrdma_fixup_pg,
-	TP_PROTO(
-		const struct rpc_rqst *rqst,
-		int pageno,
-		const void *pos,
-		int len,
-		int curlen
-	),
-
-	TP_ARGS(rqst, pageno, pos, len, curlen),
-
-	TP_STRUCT__entry(
-		__field(unsigned int, task_id)
-		__field(unsigned int, client_id)
-		__field(const void *, pos)
-		__field(int, pageno)
-		__field(int, len)
-		__field(int, curlen)
-	),
-
-	TP_fast_assign(
-		__entry->task_id = rqst->rq_task->tk_pid;
-		__entry->client_id = rqst->rq_task->tk_client->cl_clid;
-		__entry->pos = pos;
-		__entry->pageno = pageno;
-		__entry->len = len;
-		__entry->curlen = curlen;
-	),
-
-	TP_printk("task:%u@%u pageno=%d pos=%p len=%d curlen=%d",
-		__entry->task_id, __entry->client_id,
-		__entry->pageno, __entry->pos, __entry->len, __entry->curlen
+	TP_printk("task:%u@%u fixup=%lu xdr=%zu/%u/%zu",
+		__entry->task_id, __entry->client_id, __entry->fixup,
+		__entry->headlen, __entry->pagelen, __entry->taillen
 	)
 );
 

include/trace/events/sunrpc.h

···
 			__get_str(addr), __get_str(port), __entry->status)
 );
 
+DECLARE_EVENT_CLASS(xprt_writelock_event,
+	TP_PROTO(
+		const struct rpc_xprt *xprt, const struct rpc_task *task
+	),
+
+	TP_ARGS(xprt, task),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, task_id)
+		__field(unsigned int, client_id)
+		__field(unsigned int, snd_task_id)
+	),
+
+	TP_fast_assign(
+		if (task) {
+			__entry->task_id = task->tk_pid;
+			__entry->client_id = task->tk_client ?
+					     task->tk_client->cl_clid : -1;
+		} else {
+			__entry->task_id = -1;
+			__entry->client_id = -1;
+		}
+		__entry->snd_task_id = xprt->snd_task ?
+					xprt->snd_task->tk_pid : -1;
+	),
+
+	TP_printk("task:%u@%u snd_task:%u",
+			__entry->task_id, __entry->client_id,
+			__entry->snd_task_id)
+);
+
+#define DEFINE_WRITELOCK_EVENT(name) \
+	DEFINE_EVENT(xprt_writelock_event, xprt_##name, \
+			TP_PROTO( \
+				const struct rpc_xprt *xprt, \
+				const struct rpc_task *task \
+			), \
+			TP_ARGS(xprt, task))
+
+DEFINE_WRITELOCK_EVENT(reserve_xprt);
+DEFINE_WRITELOCK_EVENT(release_xprt);
+
+DECLARE_EVENT_CLASS(xprt_cong_event,
+	TP_PROTO(
+		const struct rpc_xprt *xprt, const struct rpc_task *task
+	),
+
+	TP_ARGS(xprt, task),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, task_id)
+		__field(unsigned int, client_id)
+		__field(unsigned int, snd_task_id)
+		__field(unsigned long, cong)
+		__field(unsigned long, cwnd)
+		__field(bool, wait)
+	),
+
+	TP_fast_assign(
+		if (task) {
+			__entry->task_id = task->tk_pid;
+			__entry->client_id = task->tk_client ?
+					     task->tk_client->cl_clid : -1;
+		} else {
+			__entry->task_id = -1;
+			__entry->client_id = -1;
+		}
+		__entry->snd_task_id = xprt->snd_task ?
+					xprt->snd_task->tk_pid : -1;
+		__entry->cong = xprt->cong;
+		__entry->cwnd = xprt->cwnd;
+		__entry->wait = test_bit(XPRT_CWND_WAIT, &xprt->state);
+	),
+
+	TP_printk("task:%u@%u snd_task:%u cong=%lu cwnd=%lu%s",
+			__entry->task_id, __entry->client_id,
+			__entry->snd_task_id, __entry->cong, __entry->cwnd,
+			__entry->wait ? " (wait)" : "")
+);
+
+#define DEFINE_CONG_EVENT(name) \
+	DEFINE_EVENT(xprt_cong_event, xprt_##name, \
+			TP_PROTO( \
+				const struct rpc_xprt *xprt, \
+				const struct rpc_task *task \
+			), \
+			TP_ARGS(xprt, task))
+
+DEFINE_CONG_EVENT(reserve_cong);
+DEFINE_CONG_EVENT(release_cong);
+DEFINE_CONG_EVENT(get_cong);
+DEFINE_CONG_EVENT(put_cong);
+
 TRACE_EVENT(xs_stream_read_data,
 	TP_PROTO(struct rpc_xprt *xprt, ssize_t err, size_t total),
 

net/sunrpc/clnt.c

···
 			return;
 		}
 
-		printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
-				__func__, status);
 		rpc_call_rpcerror(task, -EIO);
 		return;
 	}
···
 	 * Even though there was an error, we may have acquired
 	 * a request slot somehow.  Make sure not to leak it.
 	 */
-	if (task->tk_rqstp) {
-		printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
-				__func__, status);
+	if (task->tk_rqstp)
 		xprt_release(task);
-	}
 
 	switch (status) {
 	case -ENOMEM:
···
 	case -EAGAIN:	/* woken up; retry */
 		task->tk_action = call_retry_reserve;
 		return;
-	case -EIO:	/* probably a shutdown */
-		break;
 	default:
-		printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
-				__func__, status);
-		break;
+		rpc_call_rpcerror(task, status);
 	}
-	rpc_call_rpcerror(task, status);
 }
 
 /*

net/sunrpc/xprt.c

···
 
 	if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
 		if (task == xprt->snd_task)
-			return 1;
+			goto out_locked;
 		goto out_sleep;
 	}
 	if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
 		goto out_unlock;
 	xprt->snd_task = task;
 
+out_locked:
+	trace_xprt_reserve_xprt(xprt, task);
 	return 1;
 
 out_unlock:
 	xprt_clear_locked(xprt);
 out_sleep:
-	dprintk("RPC: %5u failed to lock transport %p\n",
-			task->tk_pid, xprt);
 	task->tk_status = -EAGAIN;
 	if  (RPC_IS_SOFT(task))
 		rpc_sleep_on_timeout(&xprt->sending, task, NULL,
···
 
 	if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
 		if (task == xprt->snd_task)
-			return 1;
+			goto out_locked;
 		goto out_sleep;
 	}
 	if (req == NULL) {
 		xprt->snd_task = task;
-		return 1;
+		goto out_locked;
 	}
 	if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
 		goto out_unlock;
 	if (!xprt_need_congestion_window_wait(xprt)) {
 		xprt->snd_task = task;
-		return 1;
+		goto out_locked;
 	}
 out_unlock:
 	xprt_clear_locked(xprt);
 out_sleep:
-	dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
 	task->tk_status = -EAGAIN;
 	if (RPC_IS_SOFT(task))
 		rpc_sleep_on_timeout(&xprt->sending, task, NULL,
···
 	else
 		rpc_sleep_on(&xprt->sending, task, NULL);
 	return 0;
+out_locked:
+	trace_xprt_reserve_cong(xprt, task);
+	return 1;
 }
 EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
 
···
 		xprt_clear_locked(xprt);
 		__xprt_lock_write_next(xprt);
 	}
+	trace_xprt_release_xprt(xprt, task);
 }
 EXPORT_SYMBOL_GPL(xprt_release_xprt);
 
···
 		xprt_clear_locked(xprt);
 		__xprt_lock_write_next_cong(xprt);
 	}
+	trace_xprt_release_cong(xprt, task);
 }
 EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
 
···
 {
 	if (req->rq_cong)
 		return 1;
-	dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
-			req->rq_task->tk_pid, xprt->cong, xprt->cwnd);
+	trace_xprt_get_cong(xprt, req->rq_task);
 	if (RPCXPRT_CONGESTED(xprt)) {
 		xprt_set_congestion_window_wait(xprt);
 		return 0;
···
 	req->rq_cong = 0;
 	xprt->cong -= RPC_CWNDSCALE;
 	xprt_test_and_clear_congestion_window_wait(xprt);
+	trace_xprt_put_cong(xprt, req->rq_task);
 	__xprt_lock_write_next_cong(xprt);
 }
 

net/sunrpc/xprtrdma/backchannel.c

···
 	*p = xdr_zero;
 
 	if (rpcrdma_prepare_send_sges(r_xprt, req, RPCRDMA_HDRLEN_MIN,
-				      &rqst->rq_snd_buf, rpcrdma_noch))
+				      &rqst->rq_snd_buf, rpcrdma_noch_pullup))
 		return -EIO;
 
 	trace_xprtrdma_cb_reply(rqst);

net/sunrpc/xprtrdma/frwr_ops.c

···
  * connect worker from running concurrently.
  *
  * When the underlying transport disconnects, MRs that are in flight
- * are flushed and are likely unusable. Thus all flushed MRs are
- * destroyed. New MRs are created on demand.
+ * are flushed and are likely unusable. Thus all MRs are destroyed.
+ * New MRs are created on demand.
  */
 
 #include <linux/sunrpc/rpc_rdma.h>
···
 	kfree(mr);
 }
 
-static void frwr_mr_recycle(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr)
+static void frwr_mr_recycle(struct rpcrdma_mr *mr)
 {
+	struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
+
 	trace_xprtrdma_mr_recycle(mr);
 
 	if (mr->mr_dir != DMA_NONE) {
···
 	spin_unlock(&r_xprt->rx_buf.rb_lock);
 
 	frwr_release_mr(mr);
-}
-
-/* MRs are dynamically allocated, so simply clean up and release the MR.
- * A replacement MR will subsequently be allocated on demand.
- */
-static void
-frwr_mr_recycle_worker(struct work_struct *work)
-{
-	struct rpcrdma_mr *mr = container_of(work, struct rpcrdma_mr,
-					     mr_recycle);
-
-	frwr_mr_recycle(mr->mr_xprt, mr);
-}
-
-/* frwr_recycle - Discard MRs
- * @req: request to reset
- *
- * Used after a reconnect. These MRs could be in flight, we can't
- * tell. Safe thing to do is release them.
- */
-void frwr_recycle(struct rpcrdma_req *req)
-{
-	struct rpcrdma_mr *mr;
-
-	while ((mr = rpcrdma_mr_pop(&req->rl_registered)))
-		frwr_mr_recycle(mr->mr_xprt, mr);
 }
 
 /* frwr_reset - Place MRs back on the free list
···
 	struct ib_mr *frmr;
 	int rc;
 
-	/* NB: ib_alloc_mr and device drivers typically allocate
-	 *     memory with GFP_KERNEL.
-	 */
 	frmr = ib_alloc_mr(ia->ri_pd, ia->ri_mrtype, depth);
 	if (IS_ERR(frmr))
 		goto out_mr_err;
···
 	mr->frwr.fr_mr = frmr;
 	mr->mr_dir = DMA_NONE;
 	INIT_LIST_HEAD(&mr->mr_list);
-	INIT_WORK(&mr->mr_recycle, frwr_mr_recycle_worker);
 	init_completion(&mr->frwr.fr_linv_done);
 
 	sg_init_table(sg, depth);
···
 	struct ib_send_wr *post_wr;
 	struct rpcrdma_mr *mr;
 
-	post_wr = &req->rl_sendctx->sc_wr;
+	post_wr = &req->rl_wr;
 	list_for_each_entry(mr, &req->rl_registered, mr_list) {
 		struct rpcrdma_frwr *frwr;
 
···
 		post_wr = &frwr->fr_regwr.wr;
 	}
 
-	/* If ib_post_send fails, the next ->send_request for
-	 * @req will queue these MRs for recovery.
-	 */
 	return ib_post_send(ia->ri_id->qp, post_wr, NULL);
 }
 
···
 static void __frwr_release_mr(struct ib_wc *wc, struct rpcrdma_mr *mr)
 {
 	if (wc->status != IB_WC_SUCCESS)
-		rpcrdma_mr_recycle(mr);
+		frwr_mr_recycle(mr);
 	else
 		rpcrdma_mr_put(mr);
 }
···
 	 */
 	bad_wr = NULL;
 	rc = ib_post_send(r_xprt->rx_ia.ri_id->qp, first, &bad_wr);
-	trace_xprtrdma_post_send(req, rc);
 
 	/* The final LOCAL_INV WR in the chain is supposed to
 	 * do the wake. If it was never posted, the wake will
···
 
 	/* Recycle MRs in the LOCAL_INV chain that did not get posted.
 	 */
+	trace_xprtrdma_post_linv(req, rc);
 	while (bad_wr) {
 		frwr = container_of(bad_wr, struct rpcrdma_frwr,
 				    fr_invwr);
···
 		bad_wr = bad_wr->next;
 
 		list_del_init(&mr->mr_list);
-		rpcrdma_mr_recycle(mr);
+		frwr_mr_recycle(mr);
 	}
 }
 
···
 	 */
 	bad_wr = NULL;
 	rc = ib_post_send(r_xprt->rx_ia.ri_id->qp, first, &bad_wr);
-	trace_xprtrdma_post_send(req, rc);
 	if (!rc)
 		return;
 
 	/* Recycle MRs in the LOCAL_INV chain that did not get posted.
 	 */
+	trace_xprtrdma_post_linv(req, rc);
 	while (bad_wr) {
 		frwr = container_of(bad_wr, struct rpcrdma_frwr, fr_invwr);
 		mr = container_of(frwr, struct rpcrdma_mr, frwr);
 		bad_wr = bad_wr->next;
 
-		rpcrdma_mr_recycle(mr);
+		frwr_mr_recycle(mr);
 	}
 
 	/* The final LOCAL_INV WR in the chain is supposed to

net/sunrpc/xprtrdma/rpc_rdma.c

···
 	size += rpcrdma_segment_maxsz * sizeof(__be32);
 	size += sizeof(__be32);	/* list discriminator */
 
-	dprintk("RPC:       %s: max call header size = %u\n",
-		__func__, size);
 	return size;
 }
 
···
 	size += maxsegs * rpcrdma_segment_maxsz * sizeof(__be32);
 	size += sizeof(__be32);	/* list discriminator */
 
-	dprintk("RPC:       %s: max reply header size = %u\n",
-		__func__, size);
 	return size;
 }
 
···
 out_getmr_err:
 	trace_xprtrdma_nomrs(req);
 	xprt_wait_for_buffer_space(&r_xprt->rx_xprt);
-	if (r_xprt->rx_ep.rep_connected != -ENODEV)
-		schedule_work(&r_xprt->rx_buf.rb_refresh_worker);
+	rpcrdma_mrs_refresh(r_xprt);
 	return ERR_PTR(-EAGAIN);
 }
 
···
 	unsigned int pos;
 	int nsegs;
 
-	if (rtype == rpcrdma_noch)
+	if (rtype == rpcrdma_noch_pullup || rtype == rpcrdma_noch_mapped)
 		goto done;
 
 	pos = rqst->rq_snd_buf.head[0].iov_len;
···
  */
 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc)
 {
+	struct rpcrdma_regbuf *rb = sc->sc_req->rl_sendbuf;
 	struct ib_sge *sge;
 
 	if (!sc->sc_unmap_count)
···
 	 */
 	for (sge = &sc->sc_sges[2]; sc->sc_unmap_count;
 	     ++sge, --sc->sc_unmap_count)
-		ib_dma_unmap_page(sc->sc_device, sge->addr, sge->length,
+		ib_dma_unmap_page(rdmab_device(rb), sge->addr, sge->length,
 				  DMA_TO_DEVICE);
 
 	kref_put(&sc->sc_req->rl_kref, rpcrdma_sendctx_done);
···
 {
 	struct rpcrdma_sendctx *sc = req->rl_sendctx;
 	struct rpcrdma_regbuf *rb = req->rl_rdmabuf;
-	struct ib_sge *sge = sc->sc_sges;
+	struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
 
 	if (!rpcrdma_regbuf_dma_map(r_xprt, rb))
-		goto out_regbuf;
+		return false;
 	sge->addr = rdmab_addr(rb);
 	sge->length = len;
 	sge->lkey = rdmab_lkey(rb);
 
 	ib_dma_sync_single_for_device(rdmab_device(rb), sge->addr, sge->length,
 				      DMA_TO_DEVICE);
-	sc->sc_wr.num_sge++;
+	return true;
+}
+
+/* The head iovec is straightforward, as it is usually already
+ * DMA-mapped. Sync the content that has changed.
+ */
+static bool rpcrdma_prepare_head_iov(struct rpcrdma_xprt *r_xprt,
+				     struct rpcrdma_req *req, unsigned int len)
+{
+	struct rpcrdma_sendctx *sc = req->rl_sendctx;
+	struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
+	struct rpcrdma_regbuf *rb = req->rl_sendbuf;
+
+	if (!rpcrdma_regbuf_dma_map(r_xprt, rb))
+		return false;
+
+	sge->addr = rdmab_addr(rb);
+	sge->length = len;
+	sge->lkey = rdmab_lkey(rb);
+
+	ib_dma_sync_single_for_device(rdmab_device(rb), sge->addr, sge->length,
+				      DMA_TO_DEVICE);
+	return true;
+}
+
+/* If there is a page list present, DMA map and prepare an
+ * SGE for each page to be sent.
+ */
+static bool rpcrdma_prepare_pagelist(struct rpcrdma_req *req,
+				     struct xdr_buf *xdr)
+{
+	struct rpcrdma_sendctx *sc = req->rl_sendctx;
+	struct rpcrdma_regbuf *rb = req->rl_sendbuf;
+	unsigned int page_base, len, remaining;
+	struct page **ppages;
+	struct ib_sge *sge;
+
+	ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
+	page_base = offset_in_page(xdr->page_base);
+	remaining = xdr->page_len;
+	while (remaining) {
+		sge = &sc->sc_sges[req->rl_wr.num_sge++];
+		len = min_t(unsigned int, PAGE_SIZE - page_base, remaining);
+		sge->addr = ib_dma_map_page(rdmab_device(rb), *ppages,
+					    page_base, len, DMA_TO_DEVICE);
+		if (ib_dma_mapping_error(rdmab_device(rb), sge->addr))
+			goto out_mapping_err;
+
+		sge->length = len;
+		sge->lkey = rdmab_lkey(rb);
+
+		sc->sc_unmap_count++;
+		ppages++;
+		remaining -= len;
+		page_base = 0;
+	}
+
 	return true;
 
-out_regbuf:
-	pr_err("rpcrdma: failed to DMA map a Send buffer\n");
+out_mapping_err:
+	trace_xprtrdma_dma_maperr(sge->addr);
 	return false;
 }
 
-/* Prepare the Send SGEs. The head and tail iovec, and each entry
- * in the page list, gets its own SGE.
+/* The tail iovec may include an XDR pad for the page list,
+ * as well as additional content, and may not reside in the
+ * same page as the head iovec.
  */
-static bool rpcrdma_prepare_msg_sges(struct rpcrdma_xprt *r_xprt,
-				     struct rpcrdma_req *req,
+static bool rpcrdma_prepare_tail_iov(struct rpcrdma_req *req,
 				     struct xdr_buf *xdr,
-				     enum rpcrdma_chunktype rtype)
+				     unsigned int page_base, unsigned int len)
 {
 	struct rpcrdma_sendctx *sc = req->rl_sendctx;
-	unsigned int sge_no, page_base, len, remaining;
+	struct ib_sge *sge = &sc->sc_sges[req->rl_wr.num_sge++];
 	struct rpcrdma_regbuf *rb = req->rl_sendbuf;
-	struct ib_sge *sge = sc->sc_sges;
-	struct page *page, **ppages;
+	struct page *page = virt_to_page(xdr->tail[0].iov_base);
 
-	/* The head iovec is straightforward, as it is already
-	 * DMA-mapped. Sync the content that has changed.
-	 */
-	if (!rpcrdma_regbuf_dma_map(r_xprt, rb))
-		goto out_regbuf;
-	sc->sc_device = rdmab_device(rb);
-	sge_no = 1;
-	sge[sge_no].addr = rdmab_addr(rb);
-	sge[sge_no].length = xdr->head[0].iov_len;
-	sge[sge_no].lkey = rdmab_lkey(rb);
-	ib_dma_sync_single_for_device(rdmab_device(rb), sge[sge_no].addr,
-				      sge[sge_no].length, DMA_TO_DEVICE);
+	sge->addr = ib_dma_map_page(rdmab_device(rb), page, page_base, len,
+				    DMA_TO_DEVICE);
+	if (ib_dma_mapping_error(rdmab_device(rb), sge->addr))
+		goto out_mapping_err;
 
-	/* If there is a Read chunk, the page list is being handled
-	 * via explicit RDMA, and thus is skipped here. However, the
-	 * tail iovec may include an XDR pad for the page list, as
-	 * well as additional content, and may not reside in the
-	 * same page as the head iovec.
-	 */
-	if (rtype == rpcrdma_readch) {
-		len = xdr->tail[0].iov_len;
-
-		/* Do not include the tail if it is only an XDR pad */
-		if (len < 4)
-			goto out;
-
-		page = virt_to_page(xdr->tail[0].iov_base);
-		page_base = offset_in_page(xdr->tail[0].iov_base);
-
-		/* If the content in the page list is an odd length,
-		 * xdr_write_pages() has added a pad at the beginning
-		 * of the tail iovec. Force the tail's non-pad content
-		 * to land at the next XDR position in the Send message.
-		 */
-		page_base += len & 3;
-		len -= len & 3;
-		goto map_tail;
-	}
-
-	/* If there is a page list present, temporarily DMA map
-	 * and prepare an SGE for each page to be sent.
-	 */
-	if (xdr->page_len) {
-		ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
-		page_base = offset_in_page(xdr->page_base);
-		remaining = xdr->page_len;
-		while (remaining) {
-			sge_no++;
-			if (sge_no > RPCRDMA_MAX_SEND_SGES - 2)
-				goto out_mapping_overflow;
-
-			len = min_t(u32, PAGE_SIZE - page_base, remaining);
-			sge[sge_no].addr =
-				ib_dma_map_page(rdmab_device(rb), *ppages,
-						page_base, len, DMA_TO_DEVICE);
-			if (ib_dma_mapping_error(rdmab_device(rb),
-						 sge[sge_no].addr))
-				goto out_mapping_err;
-			sge[sge_no].length = len;
-			sge[sge_no].lkey = rdmab_lkey(rb);
-
-			sc->sc_unmap_count++;
-			ppages++;
-			remaining -= len;
-			page_base = 0;
-		}
-	}
-
-	/* The tail iovec is not always constructed in the same
-	 * page where the head iovec resides (see, for example,
-	 * gss_wrap_req_priv). To neatly accommodate that case,
-	 * DMA map it separately.
-	 */
-	if (xdr->tail[0].iov_len) {
-		page = virt_to_page(xdr->tail[0].iov_base);
-		page_base = offset_in_page(xdr->tail[0].iov_base);
-		len = xdr->tail[0].iov_len;
-
-map_tail:
-		sge_no++;
-		sge[sge_no].addr =
-			ib_dma_map_page(rdmab_device(rb), page, page_base, len,
-					DMA_TO_DEVICE);
-		if (ib_dma_mapping_error(rdmab_device(rb), sge[sge_no].addr))
-			goto out_mapping_err;
-		sge[sge_no].length = len;
-		sge[sge_no].lkey = rdmab_lkey(rb);
-		sc->sc_unmap_count++;
-	}
-
-out:
-	sc->sc_wr.num_sge += sge_no;
-	if (sc->sc_unmap_count)
-		kref_get(&req->rl_kref);
+	sge->length = len;
+	sge->lkey = rdmab_lkey(rb);
+	++sc->sc_unmap_count;
 	return true;
 
-out_regbuf:
-	pr_err("rpcrdma: failed to DMA map a Send buffer\n");
-	return false;
-
-out_mapping_overflow:
-	rpcrdma_sendctx_unmap(sc);
-	pr_err("rpcrdma: too many Send SGEs (%u)\n", sge_no);
-	return false;
-
 out_mapping_err:
-	rpcrdma_sendctx_unmap(sc);
-	trace_xprtrdma_dma_maperr(sge[sge_no].addr);
+	trace_xprtrdma_dma_maperr(sge->addr);
 	return false;
+}
+
+/* Copy the tail to the end of the head buffer.
+ */
+static void rpcrdma_pullup_tail_iov(struct rpcrdma_xprt *r_xprt,
+				    struct rpcrdma_req *req,
+				    struct xdr_buf *xdr)
+{
+	unsigned char *dst;
+
+	dst = (unsigned char *)xdr->head[0].iov_base;
+	dst += xdr->head[0].iov_len + xdr->page_len;
+	memmove(dst, xdr->tail[0].iov_base, xdr->tail[0].iov_len);
+	r_xprt->rx_stats.pullup_copy_count += xdr->tail[0].iov_len;
+}
+
+/* Copy pagelist content into the head buffer.
+ */
+static void rpcrdma_pullup_pagelist(struct rpcrdma_xprt *r_xprt,
+				    struct rpcrdma_req *req,
+				    struct xdr_buf *xdr)
+{
+	unsigned int len, page_base, remaining;
+	struct page **ppages;
+	unsigned char *src, *dst;
+
+	dst = (unsigned char *)xdr->head[0].iov_base;
+	dst += xdr->head[0].iov_len;
+	ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
+	page_base = offset_in_page(xdr->page_base);
+	remaining = xdr->page_len;
+	while (remaining) {
+		src = page_address(*ppages);
+		src += page_base;
+		len = min_t(unsigned int, PAGE_SIZE - page_base, remaining);
+		memcpy(dst, src, len);
+		r_xprt->rx_stats.pullup_copy_count += len;
+
+		ppages++;
+		dst += len;
+		remaining -= len;
+		page_base = 0;
+	}
+}
+
+/* Copy the contents of @xdr into @rl_sendbuf and DMA sync it.
+ * When the head, pagelist, and tail are small, a pull-up copy
+ * is considerably less costly than DMA mapping the components
+ * of @xdr.
+ *
+ * Assumptions:
+ *  - the caller has already verified that the total length
+ *    of the RPC Call body will fit into @rl_sendbuf.
+ */
+static bool rpcrdma_prepare_noch_pullup(struct rpcrdma_xprt *r_xprt,
+					struct rpcrdma_req *req,
+					struct xdr_buf *xdr)
+{
+	if (unlikely(xdr->tail[0].iov_len))
+		rpcrdma_pullup_tail_iov(r_xprt, req, xdr);
+
+	if (unlikely(xdr->page_len))
+		rpcrdma_pullup_pagelist(r_xprt, req, xdr);
+
+	/* The whole RPC message resides in the head iovec now */
+	return rpcrdma_prepare_head_iov(r_xprt, req, xdr->len);
+}
+
+static bool rpcrdma_prepare_noch_mapped(struct rpcrdma_xprt *r_xprt,
+					struct rpcrdma_req *req,
+					struct xdr_buf *xdr)
+{
+	struct kvec *tail = &xdr->tail[0];
+
+	if (!rpcrdma_prepare_head_iov(r_xprt, req, xdr->head[0].iov_len))
+		return false;
+	if (xdr->page_len)
+		if (!rpcrdma_prepare_pagelist(req, xdr))
+			return false;
+	if (tail->iov_len)
+		if (!rpcrdma_prepare_tail_iov(req, xdr,
+					      offset_in_page(tail->iov_base),
+					      tail->iov_len))
+			return false;
+
+	if (req->rl_sendctx->sc_unmap_count)
+		kref_get(&req->rl_kref);
+	return true;
+}
+
+static bool rpcrdma_prepare_readch(struct rpcrdma_xprt *r_xprt,
+				   struct rpcrdma_req *req,
+				   struct xdr_buf *xdr)
+{
+	if (!rpcrdma_prepare_head_iov(r_xprt, req, xdr->head[0].iov_len))
+		return false;
+
+	/* If there is a Read chunk, the page list is being handled
+	 * via explicit RDMA, and thus is skipped here.
+	 */
+
+	/* Do not include the tail if it is only an XDR pad */
+	if (xdr->tail[0].iov_len > 3) {
+		unsigned int page_base, len;
+
+		/* If the content in the page list is an odd length,
+		 * xdr_write_pages() adds a pad at the beginning of
+		 * the tail iovec. Force the tail's non-pad content to
+		 * land at the next XDR position in the Send message.
+		 */
+		page_base = offset_in_page(xdr->tail[0].iov_base);
+		len = xdr->tail[0].iov_len;
+		page_base += len & 3;
+		len -= len & 3;
+		if (!rpcrdma_prepare_tail_iov(req, xdr, page_base, len))
+			return false;
+		kref_get(&req->rl_kref);
+	}
+
+	return true;
 }
 
 /**
···
  *
  * Returns 0 on success; otherwise a negative errno is returned.
  */
-int
-rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
-			  struct rpcrdma_req *req, u32 hdrlen,
-			  struct xdr_buf *xdr, enum rpcrdma_chunktype rtype)
+inline int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
+				     struct rpcrdma_req *req, u32 hdrlen,
+				     struct xdr_buf *xdr,
+				     enum rpcrdma_chunktype rtype)
 {
 	int ret;
 
 	ret = -EAGAIN;
 	req->rl_sendctx = rpcrdma_sendctx_get_locked(r_xprt);
 	if (!req->rl_sendctx)
-		goto err;
-	req->rl_sendctx->sc_wr.num_sge = 0;
+		goto out_nosc;
 	req->rl_sendctx->sc_unmap_count = 0;
 	req->rl_sendctx->sc_req = req;
 	kref_init(&req->rl_kref);
+	req->rl_wr.wr_cqe = &req->rl_sendctx->sc_cqe;
+	req->rl_wr.sg_list = req->rl_sendctx->sc_sges;
+	req->rl_wr.num_sge = 0;
+	req->rl_wr.opcode = IB_WR_SEND;
 
 	ret = -EIO;
 	if (!rpcrdma_prepare_hdr_sge(r_xprt, req, hdrlen))
-		goto err;
-	if (rtype != rpcrdma_areadch)
-		if (!rpcrdma_prepare_msg_sges(r_xprt, req, xdr, rtype))
-			goto err;
+		goto out_unmap;
+
+	switch (rtype) {
+	case rpcrdma_noch_pullup:
+		if (!rpcrdma_prepare_noch_pullup(r_xprt, req, xdr))
+			goto out_unmap;
+		break;
+	case rpcrdma_noch_mapped:
+		if (!rpcrdma_prepare_noch_mapped(r_xprt, req, xdr))
+			goto out_unmap;
+		break;
+	case rpcrdma_readch:
+		if (!rpcrdma_prepare_readch(r_xprt, req, xdr))
+			goto out_unmap;
+		break;
+	case rpcrdma_areadch:
+		break;
+	default:
+		goto out_unmap;
+	}
+
 	return 0;
 
-err:
+out_unmap:
+	rpcrdma_sendctx_unmap(req->rl_sendctx);
+out_nosc:
 	trace_xprtrdma_prepsend_failed(&req->rl_slot, ret);
 	return ret;
 }
···
 	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 	struct xdr_stream *xdr = &req->rl_stream;
 	enum rpcrdma_chunktype rtype, wtype;
+	struct xdr_buf *buf = &rqst->rq_snd_buf;
 	bool ddp_allowed;
 	__be32 *p;
 	int ret;
···
 	 */
 	if (rpcrdma_args_inline(r_xprt, rqst)) {
 		*p++ = rdma_msg;
-		rtype = rpcrdma_noch;
-	} else if (ddp_allowed && rqst->rq_snd_buf.flags & XDRBUF_WRITE) {
+		rtype = buf->len < rdmab_length(req->rl_sendbuf) ?
+			rpcrdma_noch_pullup : rpcrdma_noch_mapped;
+	} else if (ddp_allowed && buf->flags & XDRBUF_WRITE) {
 		*p++ = rdma_msg;
 		rtype = rpcrdma_readch;
 	} else {
···
 		*p++ = rdma_nomsg;
 		rtype = rpcrdma_areadch;
 	}
-
-	/* If this is a retransmit, discard previously registered
-	 * chunks. Very likely the connection has been replaced,
-	 * so these registrations are invalid and unusable.
-	 */
-	frwr_recycle(req);
 
 	/* This implementation supports the following combinations
 	 * of chunk lists in one RPC-over-RDMA Call message:
···
 		goto out_err;
 
 	ret = rpcrdma_prepare_send_sges(r_xprt, req, req->rl_hdrbuf.len,
-					&rqst->rq_snd_buf, rtype);
+					buf, rtype);
 	if (ret)
 		goto out_err;
 
···
 	r_xprt->rx_stats.failed_marshal_count++;
 	frwr_reset(req);
 	return ret;
+}
+
+static void __rpcrdma_update_cwnd_locked(struct rpc_xprt *xprt,
+					 struct rpcrdma_buffer *buf,
+					 u32 grant)
+{
+	buf->rb_credits = grant;
+	xprt->cwnd = grant << RPC_CWNDSHIFT;
+}
+
+static void rpcrdma_update_cwnd(struct rpcrdma_xprt *r_xprt, u32 grant)
+{
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+
+	spin_lock(&xprt->transport_lock);
+	__rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, grant);
+	spin_unlock(&xprt->transport_lock);
+}
+
+/**
+ * rpcrdma_reset_cwnd - Reset the xprt's congestion window
+ * @r_xprt: controlling transport instance
+ *
+ * Prepare @r_xprt for the next connection by reinitializing
+ * its credit grant to one (see RFC 8166, Section 3.3.3).
+ */
+void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt)
+{
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+
+	spin_lock(&xprt->transport_lock);
+	xprt->cong = 0;
+	__rpcrdma_update_cwnd_locked(xprt, &r_xprt->rx_buf, 1);
+	spin_unlock(&xprt->transport_lock);
 }
 
 /**
···
 	curlen = rqst->rq_rcv_buf.head[0].iov_len;
 	if (curlen > copy_len)
 		curlen = copy_len;
-	trace_xprtrdma_fixup(rqst, copy_len, curlen);
 	srcp += curlen;
 	copy_len -= curlen;
 
···
 			if (curlen > pagelist_len)
 				curlen = pagelist_len;
 
-			trace_xprtrdma_fixup_pg(rqst, i, srcp,
-						copy_len, curlen);
 			destp = kmap_atomic(ppages[i]);
 			memcpy(destp + page_base, srcp, curlen);
 			flush_dcache_page(ppages[i]);
···
 		rqst->rq_private_buf.tail[0].iov_base = srcp;
 	}
 
+	if (fixup_copy_count)
+		trace_xprtrdma_fixup(rqst, fixup_copy_count);
 	return fixup_copy_count;
 }
 
···
 		credits = 1;	/* don't deadlock */
 	else if (credits > buf->rb_max_requests)
 		credits = buf->rb_max_requests;
-	if (buf->rb_credits != credits) {
-		spin_lock(&xprt->transport_lock);
-		buf->rb_credits = credits;
-		xprt->cwnd = credits << RPC_CWNDSHIFT;
-		spin_unlock(&xprt->transport_lock);
-	}
+	if (buf->rb_credits != credits)
+		rpcrdma_update_cwnd(r_xprt, credits);
+	rpcrdma_post_recvs(r_xprt, false);
 
 	req = rpcr_to_rdmar(rqst);
 	if (req->rl_reply) {

net/sunrpc/xprtrdma/transport.c

···
 	rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 	xprt_clear_connecting(xprt);
 	if (r_xprt->rx_ep.rep_connected > 0) {
-		if (!xprt_test_and_set_connected(xprt)) {
-			xprt->stat.connect_count++;
-			xprt->stat.connect_time += (long)jiffies -
-						   xprt->stat.connect_start;
-			xprt_wake_pending_tasks(xprt, -EAGAIN);
-		}
-	} else {
-		if (xprt_test_and_clear_connected(xprt))
-			xprt_wake_pending_tasks(xprt, rc);
+		xprt->stat.connect_count++;
+		xprt->stat.connect_time += (long)jiffies -
+					   xprt->stat.connect_start;
+		xprt_set_connected(xprt);
+		rc = -EAGAIN;
 	}
+	xprt_wake_pending_tasks(xprt, rc);
 }
 
 /**
···
 		return;
 	rpcrdma_ep_disconnect(ep, ia);
 
-	/* Prepare @xprt for the next connection by reinitializing
-	 * its credit grant to one (see RFC 8166, Section 3.3.3).
-	 */
-	r_xprt->rx_buf.rb_credits = 1;
-	xprt->cwnd = RPC_CWNDSHIFT;
-
 out:
 	xprt->reestablish_timeout = 0;
 	++xprt->connect_cookie;
···
 	struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 	char buf[8];
 
-	dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
-		__func__, xprt,
-		xprt->address_strings[RPC_DISPLAY_ADDR],
-		xprt->address_strings[RPC_DISPLAY_PORT],
-		port);
-
 	rpc_set_port(sap, port);
 
 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
···
 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 	snprintf(buf, sizeof(buf), "%4hx", port);
 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
+
+	trace_xprtrdma_op_setport(container_of(xprt, struct rpcrdma_xprt,
+					       rx_xprt));
 }
 
 /**
···
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 	unsigned long delay;
 
-	trace_xprtrdma_op_connect(r_xprt);
-
 	delay = 0;
 	if (r_xprt->rx_ep.rep_connected != 0) {
 		delay = xprt_reconnect_delay(xprt);
 		xprt_reconnect_backoff(xprt, RPCRDMA_INIT_REEST_TO);
 	}
+	trace_xprtrdma_op_connect(r_xprt, delay);
 	queue_delayed_work(xprtiod_workqueue, &r_xprt->rx_connect_worker,
 			   delay);
 }

net/sunrpc/xprtrdma/verbs.c

···
 /*
  * internal functions
  */
-static void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc);
+static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
+				       struct rpcrdma_sendctx *sc);
+static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt);
 static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf);
 static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
-static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
-static void rpcrdma_mr_free(struct rpcrdma_mr *mr);
+static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt);
 static struct rpcrdma_regbuf *
 rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
 		     gfp_t flags);
 static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb);
 static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb);
-static void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
 
 /* Wait for outstanding transport work to finish. ib_drain_qp
  * handles the drains in the wrong order for us, so open code
···
 
 /**
  * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
- * @cq:	completion queue (ignored)
+ * @cq:	completion queue
  * @wc:	completed WR
  *
  */
···
 
 	/* WARNING: Only wr_cqe and status are reliable at this point */
 	trace_xprtrdma_wc_send(sc, wc);
-	rpcrdma_sendctx_put_locked(sc);
+	rpcrdma_sendctx_put_locked((struct rpcrdma_xprt *)cq->cq_context, sc);
 }
 
 /**
···
 				   rdmab_addr(rep->rr_rdmabuf),
 				   wc->byte_len, DMA_FROM_DEVICE);
 
-	rpcrdma_post_recvs(r_xprt, false);
 	rpcrdma_reply_handler(rep);
 	return;
 
···
 	rpcrdma_recv_buffer_put(rep);
 }
 
-static void
-rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
-			       struct rdma_conn_param *param)
+static void rpcrdma_update_cm_private(struct rpcrdma_xprt *r_xprt,
+				      struct rdma_conn_param *param)
 {
 	const struct rpcrdma_connect_private *pmsg = param->private_data;
+	struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 	unsigned int rsize, wsize;
 
 	/* Default settings for RPC-over-RDMA Version One */
···
 		wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
 	}
 
-	if (rsize < r_xprt->rx_ep.rep_inline_recv)
-		r_xprt->rx_ep.rep_inline_recv = rsize;
-	if (wsize < r_xprt->rx_ep.rep_inline_send)
-		r_xprt->rx_ep.rep_inline_send = wsize;
-	dprintk("RPC:       %s: max send %u, max recv %u\n", __func__,
-		r_xprt->rx_ep.rep_inline_send,
-		r_xprt->rx_ep.rep_inline_recv);
+	if (rsize < ep->rep_inline_recv)
+		ep->rep_inline_recv = rsize;
+	if (wsize < ep->rep_inline_send)
+		ep->rep_inline_send = wsize;
+
 	rpcrdma_set_max_header_sizes(r_xprt);
 }
 
···
 	case RDMA_CM_EVENT_ESTABLISHED:
 		++xprt->connect_cookie;
 		ep->rep_connected = 1;
-		rpcrdma_update_connect_private(r_xprt, &event->param.conn);
+		rpcrdma_update_cm_private(r_xprt, &event->param.conn);
+		trace_xprtrdma_inline_thresh(r_xprt);
 		wake_up_all(&ep->rep_connect_wait);
 		break;
 	case RDMA_CM_EVENT_CONNECT_ERROR:
···
 	struct rdma_cm_id *id;
 	int rc;
 
-	trace_xprtrdma_conn_start(xprt);
-
 	init_completion(&ia->ri_done);
 	init_completion(&ia->ri_remove_done);
 
···
 	if (rc)
 		goto out;
 	rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
-	if (rc < 0) {
-		trace_xprtrdma_conn_tout(xprt);
+	if (rc < 0)
 		goto out;
-	}
 
 	rc = ia->ri_async_rc;
 	if (rc)
···
 	if (rc)
 		goto out;
 	rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
-	if (rc < 0) {
-		trace_xprtrdma_conn_tout(xprt);
+	if (rc < 0)
 		goto out;
-	}
 	rc = ia->ri_async_rc;
 	if (rc)
 		goto out;
···
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_req *req;
 
-	cancel_work_sync(&buf->rb_refresh_worker);
-
 	/* This is similar to rpcrdma_ep_destroy, but:
 	 * - Don't cancel the connect worker.
 	 * - Don't call rpcrdma_ep_disconnect, which waits
···
 		rpcrdma_regbuf_dma_unmap(req->rl_sendbuf);
 		rpcrdma_regbuf_dma_unmap(req->rl_recvbuf);
 	}
-	rpcrdma_mrs_destroy(buf);
+	rpcrdma_mrs_destroy(r_xprt);
 	ib_dealloc_pd(ia->ri_pd);
 	ia->ri_pd = NULL;
 
···
 	init_waitqueue_head(&ep->rep_connect_wait);
 	ep->rep_receive_count = 0;
 
-	sendcq = ib_alloc_cq_any(ia->ri_id->device, NULL,
+	sendcq = ib_alloc_cq_any(ia->ri_id->device, r_xprt,
 				 ep->rep_attr.cap.max_send_wr + 1,
 				 IB_POLL_WORKQUEUE);
 	if (IS_ERR(sendcq)) {
···
 		pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
 		goto out3;
 	}
-
-	rpcrdma_mrs_create(r_xprt);
 	return 0;
 
 out3:
···
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rdma_cm_id *id, *old;
 	int err, rc;
-
-	trace_xprtrdma_reconnect(r_xprt);
 
 	rpcrdma_ep_disconnect(&r_xprt->rx_ep, ia);
 
···
 	memcpy(&qp_init_attr, &ep->rep_attr, sizeof(qp_init_attr));
 	switch (ep->rep_connected) {
 	case 0:
-		dprintk("RPC:       %s: connecting...\n", __func__);
 		rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &qp_init_attr);
 		if (rc) {
 			rc = -ENETUNREACH;
···
 	ep->rep_connected = 0;
 	xprt_clear_connected(xprt);
 
+	rpcrdma_reset_cwnd(r_xprt);
 	rpcrdma_post_recvs(r_xprt, true);
 
 	rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
···
 		goto out;
 	}
 
-	dprintk("RPC:       %s: connected\n", __func__);
+	rpcrdma_mrs_create(r_xprt);
 
 out:
 	if (rc)
 		ep->rep_connected = rc;
 
 out_noupdate:
+	trace_xprtrdma_connect(r_xprt, rc);
 	return rc;
 }
 
···
  * @ep: endpoint to disconnect
  * @ia: associated interface adapter
  *
- * This is separate from destroy to facilitate the ability
- * to reconnect without recreating the endpoint.
- *
- * This call is not reentrant, and must not be made in parallel
- * on the same endpoint.
+ * Caller serializes. Either the transport send lock is held,
+ * or we're being called to destroy the transport.
  */
 void
 rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
···
 	trace_xprtrdma_disconnect(r_xprt, rc);
 
 	rpcrdma_xprt_drain(r_xprt);
+	rpcrdma_reqs_reset(r_xprt);
+	rpcrdma_mrs_destroy(r_xprt);
 }
 
 /* Fixed-size circular FIFO queue. This implementation is wait-free and
···
 	if (!sc)
 		return NULL;
 
-	sc->sc_wr.wr_cqe = &sc->sc_cqe;
-	sc->sc_wr.sg_list = sc->sc_sges;
-	sc->sc_wr.opcode = IB_WR_SEND;
 	sc->sc_cqe.done = rpcrdma_wc_send;
 	return sc;
 }
···
 		if (!sc)
 			return -ENOMEM;
 
-		sc->sc_xprt = r_xprt;
 		buf->rb_sc_ctxs[i] = sc;
 	}
 
···
 
 /**
  * rpcrdma_sendctx_put_locked - Release a send context
+ * @r_xprt: controlling transport instance
  * @sc: send context to release
  *
  * Usage: Called from Send completion to return a sendctxt
···
  *
  * The caller serializes calls to this function (per transport).
  */
-static void
-rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
+static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
+				       struct rpcrdma_sendctx *sc)
 {
-	struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	unsigned long next_tail;
 
 	/* Unmap SGEs of previously completed but unsignaled
···
 	/* Paired with READ_ONCE */
 	smp_store_release(&buf->rb_sc_tail, next_tail);
 
-	xprt_write_space(&sc->sc_xprt->rx_xprt);
+	xprt_write_space(&r_xprt->rx_xprt);
 }
 
 static void
···
 		mr->mr_xprt = r_xprt;
 
 		spin_lock(&buf->rb_lock);
-		list_add(&mr->mr_list, &buf->rb_mrs);
+		rpcrdma_mr_push(mr, &buf->rb_mrs);
 		list_add(&mr->mr_all, &buf->rb_all_mrs);
 		spin_unlock(&buf->rb_lock);
 	}
···
 
 	rpcrdma_mrs_create(r_xprt);
 	xprt_write_space(&r_xprt->rx_xprt);
+}
+
+/**
+ * rpcrdma_mrs_refresh - Wake the MR refresh worker
+ * @r_xprt: controlling transport instance
+ *
+ */
+void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt)
+{
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+
+	/* If there is no underlying device, it's no use to
+	 * wake the refresh worker.
+	 */
+	if (ep->rep_connected != -ENODEV) {
+		/* The work is scheduled on a WQ_MEM_RECLAIM
+		 * workqueue in order to prevent MR allocation
+		 * from recursing into NFS during direct reclaim.
+		 */
+		queue_work(xprtiod_workqueue, &buf->rb_refresh_worker);
+	}
 }
 
 /**
···
 	kfree(req);
 out1:
 	return NULL;
+}
+
+/**
+ * rpcrdma_reqs_reset - Reset all reqs owned by a transport
+ * @r_xprt: controlling transport instance
+ *
+ * ASSUMPTION: the rb_allreqs list is stable for the duration,
+ * and thus can be walked without holding rb_lock. Eg. the
+ * caller is holding the transport send lock to exclude
+ * device removal or disconnection.
+ */
+static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt)
+{
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpcrdma_req *req;
+
+	list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
+		/* Credits are valid only for one connection */
+		req->rl_slot.rq_cong = 0;
+	}
 }
 
 static struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
···
 	INIT_LIST_HEAD(&buf->rb_all_mrs);
 	INIT_WORK(&buf->rb_refresh_worker, rpcrdma_mr_refresh_worker);
 
-	rpcrdma_mrs_create(r_xprt);
-
 	INIT_LIST_HEAD(&buf->rb_send_bufs);
 	INIT_LIST_HEAD(&buf->rb_allreqs);
 
···
 	for (i = 0; i < buf->rb_max_requests; i++) {
 		struct rpcrdma_req *req;
 
-		req = rpcrdma_req_create(r_xprt, RPCRDMA_V1_DEF_INLINE_SIZE,
+		req = rpcrdma_req_create(r_xprt, RPCRDMA_V1_DEF_INLINE_SIZE * 2,
 					 GFP_KERNEL);
 		if (!req)
 			goto out;
 		list_add(&req->rl_list, &buf->rb_send_bufs);
 	}
 
-	buf->rb_credits = 1;
 	init_llist_head(&buf->rb_free_reps);
 
 	rc = rpcrdma_sendctxs_create(r_xprt);
···
  * rpcrdma_req_destroy - Destroy an rpcrdma_req object
  * @req: unused object to be destroyed
  *
- * This function assumes that the caller prevents concurrent device
- * unload and transport tear-down.
+ * Relies on caller holding the transport send lock to protect
+ * removing req->rl_all from buf->rb_all_reqs safely.
  */
 void rpcrdma_req_destroy(struct rpcrdma_req *req)
 {
+	struct rpcrdma_mr *mr;
+
 	list_del(&req->rl_all);
 
-	while (!list_empty(&req->rl_free_mrs))
-		rpcrdma_mr_free(rpcrdma_mr_pop(&req->rl_free_mrs));
+	while ((mr = rpcrdma_mr_pop(&req->rl_free_mrs))) {
+		struct rpcrdma_buffer *buf = &mr->mr_xprt->rx_buf;
+
+		spin_lock(&buf->rb_lock);
+		list_del(&mr->mr_all);
+		spin_unlock(&buf->rb_lock);
+
+		frwr_release_mr(mr);
+	}
 
 	rpcrdma_regbuf_free(req->rl_recvbuf);
 	rpcrdma_regbuf_free(req->rl_sendbuf);
···
 	kfree(req);
 }
 
-static void
-rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
+/**
+ * rpcrdma_mrs_destroy - Release all of a transport's MRs
+ * @r_xprt: controlling transport instance
+ *
+ * Relies on caller holding the transport send lock to protect
+ * removing mr->mr_list from req->rl_free_mrs safely.
+ */
+static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt)
 {
-	struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
-						   rx_buf);
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_mr *mr;
-	unsigned int count;
 
-	count = 0;
+	cancel_work_sync(&buf->rb_refresh_worker);
+
 	spin_lock(&buf->rb_lock);
 	while ((mr = list_first_entry_or_null(&buf->rb_all_mrs,
 					      struct rpcrdma_mr,
 					      mr_all)) != NULL) {
+		list_del(&mr->mr_list);
 		list_del(&mr->mr_all);
 		spin_unlock(&buf->rb_lock);
 
 		frwr_release_mr(mr);
-		count++;
+
 		spin_lock(&buf->rb_lock);
 	}
 	spin_unlock(&buf->rb_lock);
-	r_xprt->rx_stats.mrs_allocated = 0;
 }
 
 /**
···
 void
 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
 {
-	cancel_work_sync(&buf->rb_refresh_worker);
-
 	rpcrdma_sendctxs_destroy(buf);
 	rpcrdma_reps_destroy(buf);
 
···
 		list_del(&req->rl_list);
 		rpcrdma_req_destroy(req);
 	}
-
-	rpcrdma_mrs_destroy(buf);
 }
 
 /**
···
 	}
 
 	rpcrdma_mr_push(mr, &mr->mr_req->rl_free_mrs);
-}
-
-static void rpcrdma_mr_free(struct rpcrdma_mr *mr)
-{
-	struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
-	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
-
-	mr->mr_req = NULL;
-	spin_lock(&buf->rb_lock);
-	rpcrdma_mr_push(mr, &buf->rb_mrs);
-	spin_unlock(&buf->rb_lock);
 }
 
 /**
···
 		struct rpcrdma_ep *ep,
 		struct rpcrdma_req *req)
 {
-	struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
+	struct ib_send_wr *send_wr = &req->rl_wr;
 	int rc;
 
 	if (!ep->rep_send_count || kref_read(&req->rl_kref) > 1) {
···
 	return 0;
 }
 
-static void
-rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
+/**
+ * rpcrdma_post_recvs - Refill the Receive Queue
+ * @r_xprt: controlling transport instance
+ * @temp: mark Receive buffers to be deleted after use
+ *
+ */
+void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
 {
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_ep *ep = &r_xprt->rx_ep;

net/sunrpc/xprtrdma/xprt_rdma.h

···
 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
  */
 struct rpcrdma_req;
-struct rpcrdma_xprt;
 struct rpcrdma_sendctx {
-	struct ib_send_wr	sc_wr;
 	struct ib_cqe		sc_cqe;
-	struct ib_device	*sc_device;
-	struct rpcrdma_xprt	*sc_xprt;
 	struct rpcrdma_req	*sc_req;
 	unsigned int		sc_unmap_count;
 	struct ib_sge		sc_sges[];
···
 	u32			mr_handle;
 	u32			mr_length;
 	u64			mr_offset;
-	struct work_struct	mr_recycle;
 	struct list_head	mr_all;
 };
 
···
 	struct rpcrdma_rep	*rl_reply;
 	struct xdr_stream	rl_stream;
 	struct xdr_buf		rl_hdrbuf;
+	struct ib_send_wr	rl_wr;
 	struct rpcrdma_sendctx	*rl_sendctx;
 	struct rpcrdma_regbuf	*rl_rdmabuf;	/* xprt header */
 	struct rpcrdma_regbuf	*rl_sendbuf;	/* rq_snd_buf */
···
 
 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 				struct rpcrdma_req *);
+void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
 
 /*
  * Buffer calls - xprtrdma/verbs.c
···
 
 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
 void rpcrdma_mr_put(struct rpcrdma_mr *mr);
-
-static inline void
-rpcrdma_mr_recycle(struct rpcrdma_mr *mr)
-{
-	schedule_work(&mr->mr_recycle);
-}
+void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
 
 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
···
 /* Memory registration calls xprtrdma/frwr_ops.c
  */
 bool frwr_is_supported(struct ib_device *device);
-void frwr_recycle(struct rpcrdma_req *req);
 void frwr_reset(struct rpcrdma_req *req);
 int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep);
 int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr);
···
 
 enum rpcrdma_chunktype {
 	rpcrdma_noch = 0,
+	rpcrdma_noch_pullup,
+	rpcrdma_noch_mapped,
 	rpcrdma_readch,
 	rpcrdma_areadch,
 	rpcrdma_writech,
···
 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
+void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);