svcrdma: trace cc_release calls

This event brackets the svcrdma_post_* trace points. If this trace
event is enabled but does not appear as expected, that indicates a
chunk_ctxt leak.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/trace/events/rpcrdma.h

@@ -2112,6 +2112,14 @@ DEFINE_POST_CHUNK_EVENT(read);
 DEFINE_POST_CHUNK_EVENT(write);
 DEFINE_POST_CHUNK_EVENT(reply);
 
+DEFINE_EVENT(svcrdma_post_chunk_class, svcrdma_cc_release,
+	TP_PROTO(
+		const struct rpc_rdma_cid *cid,
+		int sqecount
+	),
+	TP_ARGS(cid, sqecount)
+);
+
 TRACE_EVENT(svcrdma_wc_read,
 	TP_PROTO(
 		const struct ib_wc *wc,

net/sunrpc/xprtrdma/svc_rdma_rw.c

@@ -191,6 +191,8 @@ static void svc_rdma_cc_release(struct svc_rdma_chunk_ctxt *cc,
 	struct svc_rdma_rw_ctxt *ctxt;
 	LLIST_HEAD(free);
 
+	trace_svcrdma_cc_release(&cc->cc_cid, cc->cc_sqecount);
+
 	first = last = NULL;
 	while ((ctxt = svc_rdma_next_ctxt(&cc->cc_rwctxts)) != NULL) {
 		list_del(&ctxt->rw_list);