SUNRPC: Refactor the transport request pinning

We are going to need to pin for both send and receive.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/sched.h

@@ -142,8 +142,7 @@ struct rpc_task_setup {
 #define RPC_TASK_ACTIVE		2
 #define RPC_TASK_NEED_XMIT	3
 #define RPC_TASK_NEED_RECV	4
-#define RPC_TASK_MSG_RECV	5
-#define RPC_TASK_MSG_RECV_WAIT	6
+#define RPC_TASK_MSG_PIN_WAIT	5
 
 #define RPC_IS_RUNNING(t)	test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 #define rpc_set_running(t)	set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)

include/linux/sunrpc/xprt.h

@@ -103,6 +103,7 @@ struct rpc_rqst {
 						/* A cookie used to track the
 						   state of the transport
 						   connection */
+	atomic_t		rq_pin;
 	
 	/*
 	 * Partial send handling