Re: [PATCH] SUNRPC: remove the maximum number of retries in call_bind_status

[Chuck Lever III <chuck.lever@oracle.com>]

> On Mar 8, 2023, at 1:45 PM, Dai Ngo <dai.ngo@oracle.com> wrote:
> 
> Currently call_bind_status places a hard limit of 3 to the number of
> retries on EACCES error. This limit was done to accommodate the behavior
> of a buggy server that keeps returning garbage when the NLM daemon is
> killed on the NFS server. However this change causes problem for other
> servers that take a little longer than 9 seconds for the port mapper to
> become ready when the NFS server is restarted.
> 
> This patch removes this hard coded limit and let the RPC handles
> the retry according to whether the export is soft or hard mounted.
> 
> To avoid the hang with buggy server, the client can use soft mount for
> the export.
> 
> Fixes: 0b760113a3a1 ("NLM: Don't hang forever on NLM unlock requests")
> Reported-by: Helen Chao <helen.chao@oracle.com>
> Tested-by: Helen Chao <helen.chao@oracle.com>
> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>

Helen is the royal queen of ^C  ;-)

Did you try ^C on a mount while it waits for a rebind?


> ---
> include/linux/sunrpc/sched.h | 3 +--
> net/sunrpc/clnt.c            | 3 ---
> net/sunrpc/sched.c           | 1 -
> 3 files changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
> index b8ca3ecaf8d7..8ada7dc802d3 100644
> --- a/include/linux/sunrpc/sched.h
> +++ b/include/linux/sunrpc/sched.h
> @@ -90,8 +90,7 @@ struct rpc_task {
> #endif
> 	unsigned char		tk_priority : 2,/* Task priority */
> 				tk_garb_retry : 2,
> -				tk_cred_retry : 2,
> -				tk_rebind_retry : 2;
> +				tk_cred_retry : 2;
> };
> 
> typedef void			(*rpc_action)(struct rpc_task *);
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index 0b0b9f1eed46..63b438d8564b 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -2050,9 +2050,6 @@ call_bind_status(struct rpc_task *task)
> 			status = -EOPNOTSUPP;
> 			break;
> 		}
> -		if (task->tk_rebind_retry == 0)
> -			break;
> -		task->tk_rebind_retry--;
> 		rpc_delay(task, 3*HZ);
> 		goto retry_timeout;
> 	case -ENOBUFS:
> diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
> index be587a308e05..c8321de341ee 100644
> --- a/net/sunrpc/sched.c
> +++ b/net/sunrpc/sched.c
> @@ -817,7 +817,6 @@ rpc_init_task_statistics(struct rpc_task *task)
> 	/* Initialize retry counters */
> 	task->tk_garb_retry = 2;
> 	task->tk_cred_retry = 2;
> -	task->tk_rebind_retry = 2;
> 
> 	/* starting timestamp */
> 	task->tk_start = ktime_get();
> -- 
> 2.9.5
> 

--
Chuck Lever