svcrdma: Introduce Receive completion IDs

Set up a completion ID in each svc_rdma_recv_ctxt. The ID is used
to match an incoming Receive completion to a transport and to a
previous ib_post_recv().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/linux/sunrpc/svc_rdma.h

@@ -46,6 +46,7 @@
 #include <linux/sunrpc/xdr.h>
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/rpc_rdma.h>
+#include <linux/sunrpc/rpc_rdma_cid.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
 
@@ -109,6 +110,8 @@ struct svcxprt_rdma {
 	struct work_struct   sc_work;
 
 	struct llist_head    sc_recv_ctxts;
+
+	atomic_t	     sc_completion_ids;
 };
 /* sc_flags */
 #define RDMAXPRT_CONN_PENDING	3
@@ -129,6 +132,7 @@ struct svc_rdma_recv_ctxt {
 	struct list_head	rc_list;
 	struct ib_recv_wr	rc_recv_wr;
 	struct ib_cqe		rc_cqe;
+	struct rpc_rdma_cid	rc_cid;
 	struct ib_sge		rc_recv_sge;
 	void			*rc_recv_buf;
 	struct xdr_buf		rc_arg;

include/trace/events/rpcrdma.h

@@ -59,8 +59,6 @@ DECLARE_EVENT_CLASS(rpcrdma_completion_class,
 				),					\
 				TP_ARGS(wc, cid))
 
-DEFINE_COMPLETION_EVENT(dummy);
-
 DECLARE_EVENT_CLASS(xprtrdma_reply_event,
 	TP_PROTO(
 		const struct rpcrdma_rep *rep
@@ -1849,57 +1847,48 @@ DEFINE_SENDCOMP_EVENT(send);
 
 TRACE_EVENT(svcrdma_post_recv,
 	TP_PROTO(
-		const struct ib_recv_wr *wr,
-		int status
+		const struct svc_rdma_recv_ctxt *ctxt
 	),
 
-	TP_ARGS(wr, status),
+	TP_ARGS(ctxt),
 
 	TP_STRUCT__entry(
-		__field(const void *, cqe)
-		__field(int, status)
+		__field(u32, cq_id)
+		__field(int, completion_id)
 	),
 
 	TP_fast_assign(
-		__entry->cqe = wr->wr_cqe;
-		__entry->status = status;
+		__entry->cq_id = ctxt->rc_cid.ci_queue_id;
+		__entry->completion_id = ctxt->rc_cid.ci_completion_id;
 	),
 
-	TP_printk("cqe=%p status=%d",
-		__entry->cqe, __entry->status
+	TP_printk("cq.id=%d cid=%d",
+		__entry->cq_id, __entry->completion_id
 	)
 );
 
-TRACE_EVENT(svcrdma_wc_receive,
+DEFINE_COMPLETION_EVENT(svcrdma_wc_receive);
+
+TRACE_EVENT(svcrdma_rq_post_err,
 	TP_PROTO(
-		const struct ib_wc *wc
+		const struct svcxprt_rdma *rdma,
+		int status
 	),
 
-	TP_ARGS(wc),
+	TP_ARGS(rdma, status),
 
 	TP_STRUCT__entry(
-		__field(const void *, cqe)
-		__field(u32, byte_len)
-		__field(unsigned int, status)
-		__field(u32, vendor_err)
+		__field(int, status)
+		__string(addr, rdma->sc_xprt.xpt_remotebuf)
 	),
 
 	TP_fast_assign(
-		__entry->cqe = wc->wr_cqe;
-		__entry->status = wc->status;
-		if (wc->status) {
-			__entry->byte_len = 0;
-			__entry->vendor_err = wc->vendor_err;
-		} else {
-			__entry->byte_len = wc->byte_len;
-			__entry->vendor_err = 0;
-		}
+		__entry->status = status;
+		__assign_str(addr, rdma->sc_xprt.xpt_remotebuf);
 	),
 
-	TP_printk("cqe=%p byte_len=%u status=%s (%u/0x%x)",
-		__entry->cqe, __entry->byte_len,
-		rdma_show_wc_status(__entry->status),
-		__entry->status, __entry->vendor_err
+	TP_printk("addr=%s status=%d",
+		__get_str(addr), __entry->status
 	)
 );
 

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

@@ -117,6 +117,13 @@ svc_rdma_next_recv_ctxt(struct list_head *list)
 					rc_list);
 }
 
+static void svc_rdma_recv_cid_init(struct svcxprt_rdma *rdma,
+				   struct rpc_rdma_cid *cid)
+{
+	cid->ci_queue_id = rdma->sc_rq_cq->res.id;
+	cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids);
+}
+
 static struct svc_rdma_recv_ctxt *
 svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 {
@@ -135,6 +142,8 @@ svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 	if (ib_dma_mapping_error(rdma->sc_pd->device, addr))
 		goto fail2;
 
+	svc_rdma_recv_cid_init(rdma, &ctxt->rc_cid);
+
 	ctxt->rc_recv_wr.next = NULL;
 	ctxt->rc_recv_wr.wr_cqe = &ctxt->rc_cqe;
 	ctxt->rc_recv_wr.sg_list = &ctxt->rc_recv_sge;
@@ -249,13 +258,14 @@ static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma,
 	int ret;
 
 	svc_xprt_get(&rdma->sc_xprt);
+	trace_svcrdma_post_recv(ctxt);
 	ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL);
-	trace_svcrdma_post_recv(&ctxt->rc_recv_wr, ret);
 	if (ret)
 		goto err_post;
 	return 0;
 
 err_post:
+	trace_svcrdma_rq_post_err(rdma, ret);
 	svc_rdma_recv_ctxt_put(rdma, ctxt);
 	svc_xprt_put(&rdma->sc_xprt);
 	return ret;
@@ -309,11 +319,10 @@ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
 	struct ib_cqe *cqe = wc->wr_cqe;
 	struct svc_rdma_recv_ctxt *ctxt;
 
-	trace_svcrdma_wc_receive(wc);
-
 	/* WARNING: Only wc->wr_cqe and wc->status are reliable */
 	ctxt = container_of(cqe, struct svc_rdma_recv_ctxt, rc_cqe);
 
+	trace_svcrdma_wc_receive(wc, &ctxt->rc_cid);
 	if (wc->status != IB_WC_SUCCESS)
 		goto flushed;