An RPC/RDMA client cannot retransmit on an unbroken connection,
doing so violates its flow control with the server.
Signed-off-by: Tom Talpey <talpey@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 2 ++
net/sunrpc/xprtrdma/transport.c | 16 ++++++++++++----
net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
3 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index e55427f..721dae7 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -681,6 +681,8 @@ rpcrdma_conn_func(struct rpcrdma_ep *ep)
struct rpc_xprt *xprt = ep->rep_xprt;
spin_lock_bh(&xprt->transport_lock);
+ if (++xprt->connect_cookie == 0) /* maintain a reserved value */
+ ++xprt->connect_cookie;
if (ep->rep_connected > 0) {
if (!xprt_test_and_set_connected(xprt))
xprt_wake_pending_tasks(xprt, 0);
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 89970b0..0aefc64 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -587,6 +587,7 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size)
}
dprintk("RPC: %s: size %zd, request 0x%p\n", __func__, size, req);
out:
+ req->rl_connect_cookie = 0; /* our reserved value */
return req->rl_xdr_buf;
outfail:
@@ -690,13 +691,20 @@ xprt_rdma_send_request(struct rpc_task *task)
req->rl_reply->rr_xprt = xprt;
}
- if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req)) {
- xprt_disconnect_done(xprt);
- return -ENOTCONN; /* implies disconnect */
- }
+ /* Must suppress retransmit to maintain credits */
+ if (req->rl_connect_cookie == xprt->connect_cookie)
+ goto drop_connection;
+ req->rl_connect_cookie = xprt->connect_cookie;
+
+ if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
+ goto drop_connection;
rqst->rq_bytes_sent = 0;
return 0;
+
+drop_connection:
+ xprt_disconnect_done(xprt);
+ return -ENOTCONN; /* implies disconnect */
}
static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 05b7898..2db2344 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -181,6 +181,7 @@ struct rpcrdma_req {
size_t rl_size; /* actual length of buffer */
unsigned int rl_niovs; /* 0, 2 or 4 */
unsigned int rl_nchunks; /* non-zero if chunks */
+ unsigned int rl_connect_cookie; /* retry detection */
struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
--
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