Hi, I've been pondering the messages receive_cb_reply: Got unrecognized reply: calldir 0x1 xpt_bc_xprt XXXXXXX xid XXXXXX that turn up occasionally. Google reports a variety of hits and I've seen them in a logs from a customer though I don't think they were directly related to the customer's problem. These messages suggest a callback reply from the client which the server was not expecting. I think the most likely cause that the server called rpc_shutdown_client(clp->cl_cb_client); while there were outstanding callbacks. This causes rpc_killall_tasks() to be called so that the tasks stop waiting for a reply and are discarded. The rpc_shutdown_client() call can come from nfsd4_process_cb_update() which gets runs whenever nfsd4_probe_callback() is called. This happens in quite a few places including when a new connection is bound to a session. So if a new connection is bound, the current callback channel is aborted even though it is working perfectly well. That is particularly problematic as callback request are not currently retransmitted. So I'm wondering if nfsd4_process_cb_update() should only shutdown the current cb client if there is evidence that it isn't work. I'm not certain how best to do that. One option might be to do a search similar to that in __nfsd4_find_backchannel() and see if the current session and xprt are still valid. There might be a better way. Thoughts? Thanks, NeilBrown
