[PATCH v5 1/3] NFSD: convert write_threads to netlink command

Lorenzo Bianconi
2023-11-29T17:13:12Z

Introduce write_threads netlink command similar to the ones available
through the procfs.

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(+)

diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlink/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

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 @@

#include <uapi/linux/nfsd_netlink.h>

+/* NFSD_CMD_THREADS_SET - do */
+static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_THREADS + 1] = {
+ [NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
+};
+
/* Ops table for nfsd */
static const struct genl_split_ops nfsd_nl_ops[] = {
{
@@ -19,6 +24,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
.done = nfsd_nl_rpc_status_get_done,
.flags = GENL_CMD_CAP_DUMP,
},
+ {
+ .cmd = NFSD_CMD_THREADS_SET,
+ .doit = nfsd_nl_threads_set_doit,
+ .policy = nfsd_threads_set_nl_policy,
+ .maxattr = NFSD_A_SERVER_WORKER_THREADS,
+ .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+ },
+ {
+ .cmd = NFSD_CMD_THREADS_GET,
+ .doit = nfsd_nl_threads_get_doit,
+ .flags = GENL_CMD_CAP_DO,
+ },
};

struct genl_family nfsd_nl_family __ro_after_init = {
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);

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);

extern struct genl_family nfsd_nl_family;

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_callback *cb)
return 0;
}

+/**
+ * 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 = nla_get_u32(info->attrs[NFSD_A_SERVER_WORKER_THREADS]);
+ ret = nfsd_svc(nthreads, genl_info_net(info), get_current_cred());
+
+ return ret == 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 = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!skb)
+ return -ENOMEM;
+
+ hdr = genlmsg_iput(skb, info);
+ if (!hdr) {
+ err = -EMSGSIZE;
+ goto err_free_msg;
+ }
+
+ if (nla_put_u32(skb, NFSD_A_SERVER_WORKER_THREADS,
+ nfsd_nrthreads(genl_info_net(info)))) {
+ err = -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 = (__NFSD_A_RPC_STATUS_MAX - 1)
};

+enum {
+ NFSD_A_SERVER_WORKER_THREADS = 1,
+
+ __NFSD_A_SERVER_WORKER_MAX,
+ NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
+};
+
enum {
NFSD_CMD_RPC_STATUS_GET = 1,
+ NFSD_CMD_THREADS_SET,
+ NFSD_CMD_THREADS_GET,

__NFSD_CMD_MAX,
NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)
diff --git a/tools/net/ynl/generated/nfsd-user.c b/tools/net/ynl/generated/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[] = {
[NFSD_CMD_RPC_STATUS_GET] = "rpc-status-get",
+ [NFSD_CMD_THREADS_SET] = "threads-set",
+ [NFSD_CMD_THREADS_GET] = "threads-get",
};

const char *nfsd_op_str(int op)
@@ -47,6 +49,15 @@ struct ynl_policy_nest nfsd_rpc_status_nest = {
.table = nfsd_rpc_status_policy,
};

+struct ynl_policy_attr nfsd_server_worker_policy[NFSD_A_SERVER_WORKER_MAX + 1] = {
+ [NFSD_A_SERVER_WORKER_THREADS] = { .name = "threads", .type = YNL_PT_U32, },
+};
+
+struct ynl_policy_nest nfsd_server_worker_nest = {
+ .max_attr = NFSD_A_SERVER_WORKER_MAX,
+ .table = nfsd_server_worker_policy,
+};
+
/* Common nested types */
/* ============== NFSD_CMD_RPC_STATUS_GET ============== */
/* NFSD_CMD_RPC_STATUS_GET - dump */
@@ -198,6 +209,87 @@ nfsd_rpc_status_get_dump(struct ynl_sock *ys)
return NULL;
}

+/* ============== NFSD_CMD_THREADS_SET ============== */
+/* 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 *req)
+{
+ struct nlmsghdr *nlh;
+ int err;
+
+ nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_THREADS_SET, 1);
+ ys->req_policy = &nfsd_server_worker_nest;
+
+ if (req->_present.threads)
+ mnl_attr_put_u32(nlh, NFSD_A_SERVER_WORKER_THREADS, req->threads);
+
+ err = ynl_exec(ys, nlh, NULL);
+ if (err < 0)
+ return -1;
+
+ return 0;
+}
+
+/* ============== NFSD_CMD_THREADS_GET ============== */
+/* 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 = data;
+ struct nfsd_threads_get_rsp *dst;
+ const struct nlattr *attr;
+
+ dst = yarg->data;
+
+ mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
+ unsigned int type = mnl_attr_get_type(attr);
+
+ if (type == NFSD_A_SERVER_WORKER_THREADS) {
+ if (ynl_attr_validate(yarg, attr))
+ return MNL_CB_ERROR;
+ dst->_present.threads = 1;
+ dst->threads = 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 = { .yarg = { .ys = ys, }, };
+ struct nfsd_threads_get_rsp *rsp;
+ struct nlmsghdr *nlh;
+ int err;
+
+ nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_THREADS_GET, 1);
+ ys->req_policy = &nfsd_server_worker_nest;
+ yrs.yarg.rsp_policy = &nfsd_server_worker_nest;
+
+ rsp = calloc(1, sizeof(*rsp));
+ yrs.yarg.data = rsp;
+ yrs.cb = nfsd_threads_get_rsp_parse;
+ yrs.rsp_cmd = NFSD_CMD_THREADS_GET;
+
+ err = 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 = {
.name = "nfsd",
};
diff --git a/tools/net/ynl/generated/nfsd-user.h b/tools/net/ynl/generated/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_status_get_rsp_list *rsp);
struct nfsd_rpc_status_get_rsp_list *
nfsd_rpc_status_get_dump(struct ynl_sock *ys);

+/* ============== NFSD_CMD_THREADS_SET ============== */
+/* 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(void)
+{
+ 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 = 1;
+ req->threads = threads;
+}
+
+/*
+ * set the number of running threads
+ */
+int nfsd_threads_set(struct ynl_sock *ys, struct nfsd_threads_set_req *req);
+
+/* ============== NFSD_CMD_THREADS_GET ============== */
+/* 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 */
--
2.43.0