SUNRPC: Fix backchannel reply, again

I still see "RPC: Could not send backchannel reply error: -110"
quite often, along with slow-running tests. Debugging shows that the
backchannel is still stumbling when it has to queue a callback reply
on a busy transport.

Note that every one of these timeouts causes a connection loss by
virtue of the xprt_conditional_disconnect() call in that arm of
call_cb_transmit_status().

I found that setting to_maxval is necessary to get the RPC timeout
logic to behave whenever to_exponential is not set.

Fixes: 57331a59ac ("NFSv4.1: Use the nfs_client's rpc timeouts for backchannel")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Chuck Lever 2024-06-19 09:51:08 -04:00 committed by Trond Myklebust
parent 6ba59ff422
commit 6ddc9deacc

View File

@ -1557,9 +1557,11 @@ out_drop:
*/
void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp)
{
struct rpc_timeout timeout = {
.to_increment = 0,
};
struct rpc_task *task;
int proc_error;
struct rpc_timeout timeout;
/* Build the svc_rqst used by the common processing routine */
rqstp->rq_xid = req->rq_xid;
@ -1612,6 +1614,7 @@ void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp)
timeout.to_initval = req->rq_xprt->timeout->to_initval;
timeout.to_retries = req->rq_xprt->timeout->to_retries;
}
timeout.to_maxval = timeout.to_initval;
memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
task = rpc_run_bc_task(req, &timeout);