From: Chuck Lever <chuck.lever@oracle.com>
Date: Wed, 28 Feb 2018 15:30:54 -0500
Subject: xprtrdma: "Support" call-only RPCs
Patch-mainline: v4.17-rc1
Git-commit: fb14ae8853e4f0347950f98e604fa2f4f3b3abe1
References: bsc#1103992 FATE#326009
RPC-over-RDMA version 1 credit accounting relies on there being a
response message for every RPC Call. This means that RPC procedures
that have no reply will disrupt credit accounting, just in the same
way as a retransmit would (since it is sent because no reply has
arrived). Deal with the "no reply" case the same way.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/linux/sunrpc/clnt.h | 7 +++++++
net/sunrpc/sunrpc.h | 6 ------
net/sunrpc/xprtrdma/transport.c | 6 ++++++
3 files changed, 13 insertions(+), 6 deletions(-)
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -217,5 +217,12 @@ void rpc_clnt_xprt_switch_add_xprt(struc
bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
const struct sockaddr *sap);
void rpc_cleanup_clids(void);
+
+static inline int rpc_reply_expected(struct rpc_task *task)
+{
+ return (task->tk_msg.rpc_proc != NULL) &&
+ (task->tk_msg.rpc_proc->p_decode != NULL);
+}
+
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_CLNT_H */
--- a/net/sunrpc/sunrpc.h
+++ b/net/sunrpc/sunrpc.h
@@ -37,12 +37,6 @@ struct rpc_buffer {
char data[];
};
-static inline int rpc_reply_expected(struct rpc_task *task)
-{
- return (task->tk_msg.rpc_proc != NULL) &&
- (task->tk_msg.rpc_proc->p_decode != NULL);
-}
-
static inline int sock_is_loopback(struct sock *sk)
{
struct dst_entry *dst;
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -730,6 +730,12 @@ xprt_rdma_send_request(struct rpc_task *
rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
rqst->rq_bytes_sent = 0;
+
+ /* An RPC with no reply will throw off credit accounting,
+ * so drop the connection to reset the credit grant.
+ */
+ if (!rpc_reply_expected(task))
+ goto drop_connection;
return 0;
failed_marshal: