SUNRPC don't resend a task on an offlined transport

When a task is being retried, due to an NFS error, if the assigned
transport has been put offline and the task is relocatable pick a new
transport.

Fixes: 6f081693 ("sunrpc: remove an offlined xprt using sysfs")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

net/sunrpc/clnt.c

@@ -1065,7 +1065,9 @@ rpc_task_get_next_xprt(struct rpc_clnt *clnt)
 static
 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 {
-	if (task->tk_xprt)
+	if (task->tk_xprt &&
+			!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
+                        (task->tk_flags & RPC_TASK_MOVEABLE)))
 		return;
 	if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
 		task->tk_xprt = rpc_task_get_first_xprt(clnt);