SUNRPC: Support for congestion control when queuing is enabled
Both RDMA and UDP transports require the request to get a "congestion control"
credit before they can be transmitted. Right now, this is done when
the request locks the socket. We'd like it to happen when a request attempts
to be transmitted for the first time.
In order to support retransmission of requests that already hold such
credits, we also want to ensure that they get queued first, so that we
don't deadlock with requests that have yet to obtain a credit.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index ed58761..e7c445c 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -200,6 +200,9 @@ int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst)
if (!xprt_connected(rqst->rq_xprt))
goto drop_connection;
+ if (!xprt_request_get_cong(rqst->rq_xprt, rqst))
+ return -EBADSLT;
+
rc = rpcrdma_bc_marshal_reply(rqst);
if (rc < 0)
goto failed_marshal;