Re: [PATCH RFC 03/13] NFSD: Retransmit callbacks after client reconnects

[Jeff Layton <jlayton@kernel.org>]

On Thu, 2024-01-25 at 11:28 -0500, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> NFSv4.1 clients assume that if they disconnect, that will force the
> server to resend pending callback operations once a fresh connection
> has been established.
> 
> Turns out NFSD has not been resending after reconnect.
> 
> Fixes: 7ba6cad6c88f ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors")
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfs4callback.c |   13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> index b2844abcb51f..1ff64efe1f5c 100644
> --- a/fs/nfsd/nfs4callback.c
> +++ b/fs/nfsd/nfs4callback.c
> @@ -1171,12 +1171,21 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
>  		break;
>  	case -ESERVERFAULT:
>  		++session->se_cb_seq_nr;
> -		fallthrough;
> +		nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
> +		ret = false;
> +		break;
>  	case 1:
> +		/*
> +		 * cb_seq_status remains 1 if an RPC Reply was never
> +		 * received. NFSD can't know if the client processed
> +		 * the CB_SEQUENCE operation. Ask the client to send a
> +		 * DESTROY_SESSION to recover.
> +		 */
> +		fallthrough;
>  	case -NFS4ERR_BADSESSION:
>  		nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
>  		ret = false;
> -		break;
> +		goto need_restart;
>  	case -NFS4ERR_DELAY:
>  		cb->cb_seq_status = 1;
>  		if (!rpc_restart_call(task))
> 
> 
> 

Nice work tracking that down.

Reviewed-by: Jeff Layton <jlayton@kernel.org>