Re: [PATCH 2 02/14] NFSD: Convert the callback workqueue to use delayed_work

[Jeff Layton <jlayton@kernel.org>]

On Fri, 2024-01-26 at 12:45 -0500, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> Normally, NFSv4 callback operations are supposed to be sent to the
> client as soon as they are queued up.
> 
> In a moment, I will introduce a recovery path where the server has
> to wait for the client to reconnect. We don't want a hard busy wait
> here -- the callback should be requeued to try again in several
> milliseconds.
> 
> For now, convert nfsd4_callback from struct work_struct to struct
> delayed_work, and queue with a zero delay argument. This should
> avoid behavior changes for current operation.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfs4callback.c |    6 +++---
>  fs/nfsd/state.h        |    2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> index 43b0a34a5d5b..1ed2512b3648 100644
> --- a/fs/nfsd/nfs4callback.c
> +++ b/fs/nfsd/nfs4callback.c
> @@ -887,7 +887,7 @@ static struct workqueue_struct *callback_wq;
>  
>  static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
>  {
> -	return queue_work(callback_wq, &cb->cb_work);
> +	return queue_delayed_work(callback_wq, &cb->cb_work, 0);
>  }
>  
>  static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
> @@ -1370,7 +1370,7 @@ static void
>  nfsd4_run_cb_work(struct work_struct *work)
>  {
>  	struct nfsd4_callback *cb =
> -		container_of(work, struct nfsd4_callback, cb_work);
> +		container_of(work, struct nfsd4_callback, cb_work.work);
>  	struct nfs4_client *clp = cb->cb_clp;
>  	struct rpc_clnt *clnt;
>  	int flags;
> @@ -1415,7 +1415,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
>  	cb->cb_msg.rpc_argp = cb;
>  	cb->cb_msg.rpc_resp = cb;
>  	cb->cb_ops = ops;
> -	INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
> +	INIT_DELAYED_WORK(&cb->cb_work, nfsd4_run_cb_work);
>  	cb->cb_seq_status = 1;
>  	cb->cb_status = 0;
>  	cb->cb_need_restart = false;
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 41bdc913fa71..87c4372ba36a 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -68,7 +68,7 @@ struct nfsd4_callback {
>  	struct nfs4_client *cb_clp;
>  	struct rpc_message cb_msg;
>  	const struct nfsd4_callback_ops *cb_ops;
> -	struct work_struct cb_work;
> +	struct delayed_work cb_work;
>  	int cb_seq_status;
>  	int cb_status;
>  	bool cb_need_restart;
> 
> 
> 

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