Re: [PATCH RFC 01/13] NFSD: Reset cb_seq_status after NFS4ERR_DELAY

[Jeff Layton <jlayton@kernel.org>]

On Thu, 2024-01-25 at 11:28 -0500, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> I noticed that once an NFSv4.1 callback operation gets a
> NFS4ERR_DELAY status on CB_SEQUENCE and then the connection is lost,
> the callback client loops, resending it indefinitely.
> 
> The switch arm in nfsd4_cb_sequence_done() that handles
> NFS4ERR_DELAY uses rpc_restart_call() to rearm the RPC state machine
> for the retransmit, but that path does not call the rpc_prepare_call
> callback again. Thus cb_seq_status is set to -10008 by the first
> NFS4ERR_DELAY result, but is never set back to 1 for the retransmits.
> 
> nfsd4_cb_sequence_done() thinks it's getting nothing but a
> long series of CB_SEQUENCE NFS4ERR_DELAY replies.
> 
> 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 |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> index 926c29879c6a..43b0a34a5d5b 100644
> --- a/fs/nfsd/nfs4callback.c
> +++ b/fs/nfsd/nfs4callback.c
> @@ -1178,6 +1178,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
>  		ret = false;
>  		break;
>  	case -NFS4ERR_DELAY:
> +		cb->cb_seq_status = 1;
>  		if (!rpc_restart_call(task))
>  			goto out;
>  
> 
> 
> 

Nice catch!

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