[RFC PATCH 1/1] SUNRPC: increase max timeout for rebind to handle NFS server restart

[Dai Ngo <dai.ngo@oracle.com>]

Occasionally NLM lock and unlock request fail with EIO and ENOLCK
respectively. This usually happens when the NFS server is restarted
while NLM lock test is running.

Currently there is a 9 seconds limit for retrying the bind operation.
If the server is under load the port mapper might take more than 9
seconds to become ready after the NFS server restarted.

This patch increases the timeout for rebind from 9 to 30 seconds
allowing a bit more time for the port mapper to become ready.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 include/linux/sunrpc/clnt.h  | 3 +++
 include/linux/sunrpc/sched.h | 4 ++--
 net/sunrpc/clnt.c            | 2 +-
 net/sunrpc/sched.c           | 3 ++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 770ef2cb5775..7f2dee56c121 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -162,6 +162,9 @@ struct rpc_add_xprt_test {
 #define RPC_CLNT_CREATE_REUSEPORT	(1UL << 11)
 #define RPC_CLNT_CREATE_CONNECTED	(1UL << 12)
 
+#define	RPC_CLNT_REBIND_DELAY		3
+#define	RPC_CLNT_REBIND_MAX_TIMEOUT	30
+
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
 				const struct rpc_program *, u32);
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index b8ca3ecaf8d7..e9dc142f10bb 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -90,8 +90,8 @@ struct rpc_task {
 #endif
 	unsigned char		tk_priority : 2,/* Task priority */
 				tk_garb_retry : 2,
-				tk_cred_retry : 2,
-				tk_rebind_retry : 2;
+				tk_cred_retry : 2;
+	unsigned char		tk_rebind_retry;
 };
 
 typedef void			(*rpc_action)(struct rpc_task *);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 0b0b9f1eed46..6c89a1fa40bf 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2053,7 +2053,7 @@ call_bind_status(struct rpc_task *task)
 		if (task->tk_rebind_retry == 0)
 			break;
 		task->tk_rebind_retry--;
-		rpc_delay(task, 3*HZ);
+		rpc_delay(task, RPC_CLNT_REBIND_DELAY * HZ);
 		goto retry_timeout;
 	case -ENOBUFS:
 		rpc_delay(task, HZ >> 2);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index be587a308e05..5c18a35752aa 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -817,7 +817,8 @@ rpc_init_task_statistics(struct rpc_task *task)
 	/* Initialize retry counters */
 	task->tk_garb_retry = 2;
 	task->tk_cred_retry = 2;
-	task->tk_rebind_retry = 2;
+	task->tk_rebind_retry = RPC_CLNT_REBIND_MAX_TIMEOUT /
+					RPC_CLNT_REBIND_DELAY;
 
 	/* starting timestamp */
 	task->tk_start = ktime_get();
-- 
2.9.5