Clean up. @rqst is set up differently for backchannel Replies. For
example, rqst->rq_task and task->tk_client are both NULL. So it is
easier to understand and maintain this code path if it is separated.
Also, we can get rid of the confusing rl_connect_cookie hack in
rpcrdma_bc_receive_call.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/backchannel.c | 48 +++++++++++++++++++++++++++++--------
net/sunrpc/xprtrdma/rpc_rdma.c | 5 ----
net/sunrpc/xprtrdma/transport.c | 27 ++++++++-------------
net/sunrpc/xprtrdma/xprt_rdma.h | 2 +-
4 files changed, 50 insertions(+), 32 deletions(-)
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 11fb38f..6c66a4f 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -187,13 +187,7 @@ size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt)
return maxmsg - RPCRDMA_HDRLEN_MIN;
}
-/**
- * rpcrdma_bc_marshal_reply - Send backwards direction reply
- * @rqst: buffer containing RPC reply data
- *
- * Returns zero on success.
- */
-int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
+static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
{
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
@@ -221,6 +215,43 @@ int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
}
/**
+ * xprt_rdma_bc_send_reply - marshal and send a backchannel reply
+ * @rqst: RPC rqst with a backchannel RPC reply in rq_snd_buf
+ *
+ * Caller holds the transport's write lock.
+ *
+ * Returns:
+ * %0 if the RPC message has been sent
+ * %-ENOTCONN if the caller should reconnect and call again
+ * %-EIO if a permanent error occurred and the request was not
+ * sent. Do not try to send this message again.
+ */
+int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst)
+{
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
+ struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+ int rc;
+
+ if (!xprt_connected(rqst->rq_xprt))
+ goto drop_connection;
+
+ rc = rpcrdma_bc_marshal_reply(rqst);
+ if (rc < 0)
+ goto failed_marshal;
+
+ if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
+ goto drop_connection;
+ return 0;
+
+failed_marshal:
+ if (rc != -ENOTCONN)
+ return rc;
+drop_connection:
+ xprt_disconnect_done(rqst->rq_xprt);
+ return -ENOTCONN;
+}
+
+/**
* xprt_rdma_bc_destroy - Release resources for handling backchannel requests
* @xprt: transport associated with these backchannel resources
* @reqs: number of incoming requests to destroy; ignored
@@ -330,9 +361,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
__func__, rep, req);
req->rl_reply = rep;
- /* Defeat the retransmit detection logic in send_request */
- req->rl_connect_cookie = 0;
-
/* Queue rqst for ULP's callback service */
bc_serv = xprt->bc_serv;
spin_lock(&bc_serv->sv_cb_lock);
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index dd7c0aa..9207aea 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -754,11 +754,6 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
__be32 *p;
int ret;
-#if defined(CONFIG_SUNRPC_BACKCHANNEL)
- if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
- return rpcrdma_bc_marshal_reply(rqst);
-#endif
-
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
xdr_init_encode(xdr, &req->rl_hdrbuf,
req->rl_rdmabuf->rg_base);
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index d0cd6d4..be8c4e6 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -699,22 +699,12 @@
*
* Caller holds the transport's write lock.
*
- * Return values:
- * 0: The request has been sent
- * ENOTCONN: Caller needs to invoke connect logic then call again
- * ENOBUFS: Call again later to send the request
- * EIO: A permanent error occurred. The request was not sent,
- * and don't try it again
- *
- * send_request invokes the meat of RPC RDMA. It must do the following:
- *
- * 1. Marshal the RPC request into an RPC RDMA request, which means
- * putting a header in front of data, and creating IOVs for RDMA
- * from those in the request.
- * 2. In marshaling, detect opportunities for RDMA, and use them.
- * 3. Post a recv message to set up asynch completion, then send
- * the request (rpcrdma_ep_post).
- * 4. No partial sends are possible in the RPC-RDMA protocol (as in UDP).
+ * Returns:
+ * %0 if the RPC message has been sent
+ * %-ENOTCONN if the caller should reconnect and call again
+ * %-ENOBUFS if the caller should call again later
+ * %-EIO if a permanent error occurred and the request was not
+ * sent. Do not try to send this message again.
*/
static int
xprt_rdma_send_request(struct rpc_task *task)
@@ -725,6 +715,11 @@
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
int rc = 0;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+ if (unlikely(!rqst->rq_buffer))
+ return xprt_rdma_bc_send_reply(rqst);
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
if (!xprt_connected(xprt))
goto drop_connection;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index ed7e513..e084130 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -666,7 +666,7 @@ static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
-int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
+int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
--
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