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Message-ID: <ffbbdd1ce7c87b02f75095f0146924d996268957.camel@kernel.org>
Subject: Re: [PATCH v5 1/3] NFSD: convert write_threads to netlink command
From: Jeff Layton <jlayton@kernel.org>
To: Lorenzo Bianconi <lorenzo@kernel.org>, linux-nfs@vger.kernel.org
Cc: lorenzo.bianconi@redhat.com, neilb@suse.de, netdev@vger.kernel.org, 
	kuba@kernel.org
Date: Wed, 29 Nov 2023 13:13:34 -0500
In-Reply-To: <d9461e660b5f47df7b869f0f809485c9b4bf60ea.1701277475.git.lorenzo@kernel.org>
References: <cover.1701277475.git.lorenzo@kernel.org>
	 <d9461e660b5f47df7b869f0f809485c9b4bf60ea.1701277475.git.lorenzo@kernel.org>
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On Wed, 2023-11-29 at 18:12 +0100, Lorenzo Bianconi wrote:
> Introduce write_threads netlink command similar to the ones available
> through the procfs.
>=20
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  Documentation/netlink/specs/nfsd.yaml | 23 +++++++
>  fs/nfsd/netlink.c                     | 17 +++++
>  fs/nfsd/netlink.h                     |  2 +
>  fs/nfsd/nfsctl.c                      | 58 +++++++++++++++++
>  include/uapi/linux/nfsd_netlink.h     |  9 +++
>  tools/net/ynl/generated/nfsd-user.c   | 92 +++++++++++++++++++++++++++
>  tools/net/ynl/generated/nfsd-user.h   | 47 ++++++++++++++
>  7 files changed, 248 insertions(+)
>=20
> diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlin=
k/specs/nfsd.yaml
> index 05acc73e2e33..c92e1425d316 100644
> --- a/Documentation/netlink/specs/nfsd.yaml
> +++ b/Documentation/netlink/specs/nfsd.yaml
> @@ -62,6 +62,12 @@ attribute-sets:
>          name: compound-ops
>          type: u32
>          multi-attr: true
> +  -
> +    name: server-worker
> +    attributes:
> +      -
> +        name: threads
> +        type: u32
> =20
>  operations:
>    list:
> @@ -87,3 +93,20 @@ operations:
>              - sport
>              - dport
>              - compound-ops
> +    -
> +      name: threads-set
> +      doc: set the number of running threads
> +      attribute-set: server-worker
> +      flags: [ admin-perm ]
> +      do:
> +        request:
> +          attributes:
> +            - threads
> +    -
> +      name: threads-get
> +      doc: get the number of running threads
> +      attribute-set: server-worker
> +      do:
> +        reply:
> +          attributes:
> +            - threads
> diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c
> index 0e1d635ec5f9..1a59a8e6c7e2 100644
> --- a/fs/nfsd/netlink.c
> +++ b/fs/nfsd/netlink.c
> @@ -10,6 +10,11 @@
> =20
>  #include <uapi/linux/nfsd_netlink.h>
> =20
> +/* NFSD_CMD_THREADS_SET - do */
> +static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_=
WORKER_THREADS + 1] =3D {
> +	[NFSD_A_SERVER_WORKER_THREADS] =3D { .type =3D NLA_U32, },
> +};
> +
>  /* Ops table for nfsd */
>  static const struct genl_split_ops nfsd_nl_ops[] =3D {
>  	{
> @@ -19,6 +24,18 @@ static const struct genl_split_ops nfsd_nl_ops[] =3D {
>  		.done	=3D nfsd_nl_rpc_status_get_done,
>  		.flags	=3D GENL_CMD_CAP_DUMP,
>  	},
> +	{
> +		.cmd		=3D NFSD_CMD_THREADS_SET,
> +		.doit		=3D nfsd_nl_threads_set_doit,
> +		.policy		=3D nfsd_threads_set_nl_policy,
> +		.maxattr	=3D NFSD_A_SERVER_WORKER_THREADS,
> +		.flags		=3D GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
> +	},
> +	{
> +		.cmd	=3D NFSD_CMD_THREADS_GET,
> +		.doit	=3D nfsd_nl_threads_get_doit,
> +		.flags	=3D GENL_CMD_CAP_DO,
> +	},
>  };
> =20
>  struct genl_family nfsd_nl_family __ro_after_init =3D {
> diff --git a/fs/nfsd/netlink.h b/fs/nfsd/netlink.h
> index d83dd6bdee92..4137fac477e4 100644
> --- a/fs/nfsd/netlink.h
> +++ b/fs/nfsd/netlink.h
> @@ -16,6 +16,8 @@ int nfsd_nl_rpc_status_get_done(struct netlink_callback=
 *cb);
> =20
>  int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
>  				  struct netlink_callback *cb);
> +int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info=
);
> +int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info=
);
> =20
>  extern struct genl_family nfsd_nl_family;
> =20
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index d6eeee149370..130b3d937a79 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -1699,6 +1699,64 @@ int nfsd_nl_rpc_status_get_done(struct netlink_cal=
lback *cb)
>  	return 0;
>  }
> =20
> +/**
> + * nfsd_nl_threads_set_doit - set the number of running threads
> + * @skb: reply buffer
> + * @info: netlink metadata and command arguments
> + *
> + * Return 0 on success or a negative errno.
> + */
> +int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info=
)
> +{
> +	u32 nthreads;
> +	int ret;
> +
> +	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_WORKER_THREADS))
> +		return -EINVAL;
> +
> +	nthreads =3D nla_get_u32(info->attrs[NFSD_A_SERVER_WORKER_THREADS]);
> +	ret =3D nfsd_svc(nthreads, genl_info_net(info), get_current_cred());
> +
> +	return ret =3D=3D nthreads ? 0 : ret;
> +}
> +
> +/**
> + * nfsd_nl_threads_get_doit - get the number of running threads
> + * @skb: reply buffer
> + * @info: netlink metadata and command arguments
> + *
> + * Return 0 on success or a negative errno.
> + */
> +int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info=
)
> +{
> +	void *hdr;
> +	int err;
> +
> +	skb =3D genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
> +	if (!skb)
> +		return -ENOMEM;
> +
> +	hdr =3D genlmsg_iput(skb, info);
> +	if (!hdr) {
> +		err =3D -EMSGSIZE;
> +		goto err_free_msg;
> +	}
> +
> +	if (nla_put_u32(skb, NFSD_A_SERVER_WORKER_THREADS,
> +			nfsd_nrthreads(genl_info_net(info)))) {
> +		err =3D -EINVAL;
> +		goto err_free_msg;
> +	}
> +
> +	genlmsg_end(skb, hdr);
> +
> +	return genlmsg_reply(skb, info);
> +
> +err_free_msg:
> +	nlmsg_free(skb);
> +	return err;
> +}
> +
>  /**
>   * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
>   * @net: a freshly-created network namespace
> diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/nfsd_=
netlink.h
> index 3cd044edee5d..1b6fe1f9ed0e 100644
> --- a/include/uapi/linux/nfsd_netlink.h
> +++ b/include/uapi/linux/nfsd_netlink.h
> @@ -29,8 +29,17 @@ enum {
>  	NFSD_A_RPC_STATUS_MAX =3D (__NFSD_A_RPC_STATUS_MAX - 1)
>  };
> =20
> +enum {
> +	NFSD_A_SERVER_WORKER_THREADS =3D 1,
> +
> +	__NFSD_A_SERVER_WORKER_MAX,
> +	NFSD_A_SERVER_WORKER_MAX =3D (__NFSD_A_SERVER_WORKER_MAX - 1)
> +};
> +
>  enum {
>  	NFSD_CMD_RPC_STATUS_GET =3D 1,
> +	NFSD_CMD_THREADS_SET,
> +	NFSD_CMD_THREADS_GET,
> =20
>  	__NFSD_CMD_MAX,
>  	NFSD_CMD_MAX =3D (__NFSD_CMD_MAX - 1)
> diff --git a/tools/net/ynl/generated/nfsd-user.c b/tools/net/ynl/generate=
d/nfsd-user.c
> index 360b6448c6e9..9768328a7751 100644
> --- a/tools/net/ynl/generated/nfsd-user.c
> +++ b/tools/net/ynl/generated/nfsd-user.c
> @@ -15,6 +15,8 @@
>  /* Enums */
>  static const char * const nfsd_op_strmap[] =3D {
>  	[NFSD_CMD_RPC_STATUS_GET] =3D "rpc-status-get",
> +	[NFSD_CMD_THREADS_SET] =3D "threads-set",
> +	[NFSD_CMD_THREADS_GET] =3D "threads-get",
>  };
> =20
>  const char *nfsd_op_str(int op)
> @@ -47,6 +49,15 @@ struct ynl_policy_nest nfsd_rpc_status_nest =3D {
>  	.table =3D nfsd_rpc_status_policy,
>  };
> =20
> +struct ynl_policy_attr nfsd_server_worker_policy[NFSD_A_SERVER_WORKER_MA=
X + 1] =3D {
> +	[NFSD_A_SERVER_WORKER_THREADS] =3D { .name =3D "threads", .type =3D YNL=
_PT_U32, },
> +};
> +
> +struct ynl_policy_nest nfsd_server_worker_nest =3D {
> +	.max_attr =3D NFSD_A_SERVER_WORKER_MAX,
> +	.table =3D nfsd_server_worker_policy,
> +};
> +
>  /* Common nested types */
>  /* =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D NFSD_CMD_RPC_STATUS_GET =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D */
>  /* NFSD_CMD_RPC_STATUS_GET - dump */
> @@ -198,6 +209,87 @@ nfsd_rpc_status_get_dump(struct ynl_sock *ys)
>  	return NULL;
>  }
> =20
> +/* =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D NFSD_CMD_THREADS_SET =3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D */
> +/* NFSD_CMD_THREADS_SET - do */
> +void nfsd_threads_set_req_free(struct nfsd_threads_set_req *req)
> +{
> +	free(req);
> +}
> +
> +int nfsd_threads_set(struct ynl_sock *ys, struct nfsd_threads_set_req *r=
eq)
> +{
> +	struct nlmsghdr *nlh;
> +	int err;
> +
> +	nlh =3D ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_THREADS_SET, 1)=
;
> +	ys->req_policy =3D &nfsd_server_worker_nest;
> +
> +	if (req->_present.threads)
> +		mnl_attr_put_u32(nlh, NFSD_A_SERVER_WORKER_THREADS, req->threads);
> +
> +	err =3D ynl_exec(ys, nlh, NULL);
> +	if (err < 0)
> +		return -1;
> +
> +	return 0;
> +}
> +
> +/* =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D NFSD_CMD_THREADS_GET =3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D */
> +/* NFSD_CMD_THREADS_GET - do */
> +void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp)
> +{
> +	free(rsp);
> +}
> +
> +int nfsd_threads_get_rsp_parse(const struct nlmsghdr *nlh, void *data)
> +{
> +	struct ynl_parse_arg *yarg =3D data;
> +	struct nfsd_threads_get_rsp *dst;
> +	const struct nlattr *attr;
> +
> +	dst =3D yarg->data;
> +
> +	mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
> +		unsigned int type =3D mnl_attr_get_type(attr);
> +
> +		if (type =3D=3D NFSD_A_SERVER_WORKER_THREADS) {
> +			if (ynl_attr_validate(yarg, attr))
> +				return MNL_CB_ERROR;
> +			dst->_present.threads =3D 1;
> +			dst->threads =3D mnl_attr_get_u32(attr);
> +		}
> +	}
> +
> +	return MNL_CB_OK;
> +}
> +
> +struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
> +{
> +	struct ynl_req_state yrs =3D { .yarg =3D { .ys =3D ys, }, };
> +	struct nfsd_threads_get_rsp *rsp;
> +	struct nlmsghdr *nlh;
> +	int err;
> +
> +	nlh =3D ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_THREADS_GET, 1)=
;
> +	ys->req_policy =3D &nfsd_server_worker_nest;
> +	yrs.yarg.rsp_policy =3D &nfsd_server_worker_nest;
> +
> +	rsp =3D calloc(1, sizeof(*rsp));
> +	yrs.yarg.data =3D rsp;
> +	yrs.cb =3D nfsd_threads_get_rsp_parse;
> +	yrs.rsp_cmd =3D NFSD_CMD_THREADS_GET;
> +
> +	err =3D ynl_exec(ys, nlh, &yrs);
> +	if (err < 0)
> +		goto err_free;
> +
> +	return rsp;
> +
> +err_free:
> +	nfsd_threads_get_rsp_free(rsp);
> +	return NULL;
> +}
> +
>  const struct ynl_family ynl_nfsd_family =3D  {
>  	.name		=3D "nfsd",
>  };
> diff --git a/tools/net/ynl/generated/nfsd-user.h b/tools/net/ynl/generate=
d/nfsd-user.h
> index 989c6e209ced..e162a4f20d91 100644
> --- a/tools/net/ynl/generated/nfsd-user.h
> +++ b/tools/net/ynl/generated/nfsd-user.h
> @@ -64,4 +64,51 @@ nfsd_rpc_status_get_rsp_list_free(struct nfsd_rpc_stat=
us_get_rsp_list *rsp);
>  struct nfsd_rpc_status_get_rsp_list *
>  nfsd_rpc_status_get_dump(struct ynl_sock *ys);
> =20
> +/* =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D NFSD_CMD_THREADS_SET =3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D */
> +/* NFSD_CMD_THREADS_SET - do */
> +struct nfsd_threads_set_req {
> +	struct {
> +		__u32 threads:1;
> +	} _present;
> +
> +	__u32 threads;
> +};
> +
> +static inline struct nfsd_threads_set_req *nfsd_threads_set_req_alloc(vo=
id)
> +{
> +	return calloc(1, sizeof(struct nfsd_threads_set_req));
> +}
> +void nfsd_threads_set_req_free(struct nfsd_threads_set_req *req);
> +
> +static inline void
> +nfsd_threads_set_req_set_threads(struct nfsd_threads_set_req *req,
> +				 __u32 threads)
> +{
> +	req->_present.threads =3D 1;
> +	req->threads =3D threads;
> +}
> +
> +/*
> + * set the number of running threads
> + */
> +int nfsd_threads_set(struct ynl_sock *ys, struct nfsd_threads_set_req *r=
eq);
> +
> +/* =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D NFSD_CMD_THREADS_GET =3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D */
> +/* NFSD_CMD_THREADS_GET - do */
> +
> +struct nfsd_threads_get_rsp {
> +	struct {
> +		__u32 threads:1;
> +	} _present;
> +
> +	__u32 threads;
> +};
> +
> +void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
> +
> +/*
> + * get the number of running threads
> + */
> +struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
> +
>  #endif /* _LINUX_NFSD_GEN_H */

Ok, Uncle! I'll relent on the quest for a single netlink command to
start the server. This patch looks reasonable to me.

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