On 19 Jun 2024, at 9:51, cel@xxxxxxxxxx wrote:
> From: Chuck Lever <chuck.lever@xxxxxxxxxx>
>
> 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: 57331a59ac0d ("NFSv4.1: Use the nfs_client's rpc timeouts for backchannel")
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
That makes sense - I guess we were getting some random stack value in there?
Reviewed-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Ben
> ---
> net/sunrpc/svc.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index 965a27806bfd..e03f14024e47 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -1588,9 +1588,11 @@ void svc_process(struct svc_rqst *rqstp)
> */
> 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;
> @@ -1643,6 +1645,7 @@ 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);
>
> --
> 2.45.1
