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Message-ID: <f53a3516ed477e9c74aee20eddd99411a9a0a264.camel@kernel.org>
Subject: Re: [PATCH 2 02/14] NFSD: Convert the callback workqueue to use
 delayed_work
From: Jeff Layton <jlayton@kernel.org>
To: Chuck Lever <cel@kernel.org>, linux-nfs@vger.kernel.org
Date: Fri, 26 Jan 2024 14:09:57 -0500
In-Reply-To: <170629112325.20612.15691160218281370004.stgit@manet.1015granger.net>
References: 
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On Fri, 2024-01-26 at 12:45 -0500, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
>=20
> Normally, NFSv4 callback operations are supposed to be sent to the
> client as soon as they are queued up.
>=20
> 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.
>=20
> 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.
>=20
> 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(-)
>=20
> 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;
> =20
>  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);
>  }
> =20
>  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 =3D
> -		container_of(work, struct nfsd4_callback, cb_work);
> +		container_of(work, struct nfsd4_callback, cb_work.work);
>  	struct nfs4_client *clp =3D cb->cb_clp;
>  	struct rpc_clnt *clnt;
>  	int flags;
> @@ -1415,7 +1415,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struc=
t nfs4_client *clp,
>  	cb->cb_msg.rpc_argp =3D cb;
>  	cb->cb_msg.rpc_resp =3D cb;
>  	cb->cb_ops =3D ops;
> -	INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
> +	INIT_DELAYED_WORK(&cb->cb_work, nfsd4_run_cb_work);
>  	cb->cb_seq_status =3D 1;
>  	cb->cb_status =3D 0;
>  	cb->cb_need_restart =3D 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;
>=20
>=20
>=20

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