convert write_threads, write_version and write_ports to netlink commands

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 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(+)

Documentation/netlink/specs/nfsd.yaml +23 -0

index 05acc73e2e33..c92e1425d316 100644
@@ -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

fs/nfsd/netlink.c +17 -0

index 0e1d635ec5f9..1a59a8e6c7e2 100644
@@ -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 = {

fs/nfsd/netlink.h +2 -0

index d83dd6bdee92..4137fac477e4 100644
@@ -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;
 

fs/nfsd/nfsctl.c +58 -0

index d6eeee149370..130b3d937a79 100644
@@ -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

include/uapi/linux/nfsd_netlink.h +9 -0

index 3cd044edee5d..1b6fe1f9ed0e 100644
@@ -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)

tools/net/ynl/generated/nfsd-user.c +92 -0

index 360b6448c6e9..9768328a7751 100644
@@ -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",
 };

tools/net/ynl/generated/nfsd-user.h +38 -0

index 989c6e209ced..e162a4f20d91 100644
@@ -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;

Quoted 359 lines · Lorenzo Bianconi

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 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(+)

Documentation/netlink/specs/nfsd.yaml +23 -0

index 05acc73e2e33..c92e1425d316 100644
@@ -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

fs/nfsd/netlink.c +17 -0

index 0e1d635ec5f9..1a59a8e6c7e2 100644
@@ -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 = {

fs/nfsd/netlink.h +2 -0

index d83dd6bdee92..4137fac477e4 100644
@@ -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;
 

fs/nfsd/nfsctl.c +58 -0

index d6eeee149370..130b3d937a79 100644
@@ -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

include/uapi/linux/nfsd_netlink.h +9 -0

index 3cd044edee5d..1b6fe1f9ed0e 100644
@@ -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)

tools/net/ynl/generated/nfsd-user.c +92 -0

index 360b6448c6e9..9768328a7751 100644
@@ -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",
 };

tools/net/ynl/generated/nfsd-user.h +43 -0

index 989c6e209ced..e162a4f20d91 100644
@@ -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);
+
+/*

tools/net/ynl/generated/nfsd-user.h nfsd_rpc_status_get_rsp_list_free(struct nfsd_rpc_status_get_rsp_list *rsp); · line 114

Quoted 5 lines

tools/net/ynl/generated/nfsd-user.h +4 -0

+ * 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 <[email protected]>

Before applying these, I'd like an Acked-by from Jakub for the tools/net/ynl modifications, and at least a fresh sanity check from Jakub on the changes to the nfsd netlink protocol (though I don't anything problematic so far).

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NFSD_GEN_H */

Quoted 372 lines

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Quoted 43 lines

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NFSD_GEN_H */

Signature · 1 line

Jeff Layton <[email protected]>

Quoted 432 lines · Lorenzo Bianconi

Quoted 408 lines

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---

 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +0 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:

       -
         name: threads
         type: u32

Documentation/netlink/specs/nfsd.yaml +12 -0

+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8

 operations:
   list:

Documentation/netlink/specs/nfsd.yaml +0 -0

@@ -110,3 +122,23 @@ operations:

         reply:
           attributes:
             - threads

Documentation/netlink/specs/nfsd.yaml +20 -0

+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +0 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
  	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
  };

fs/nfsd/netlink.c +7 -0

+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+

 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = { {

fs/nfsd/netlink.c +12 -0

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
  		.doit	= nfsd_nl_threads_get_doit,
  		.flags	= GENL_CMD_CAP_DO,
  	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
  };

 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);

 extern struct genl_family nfsd_nl_family;

fs/nfsd/nfsctl.c +0 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
  	return err;
  }

fs/nfsd/nfsctl.c +105 -0

+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+

 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +0 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
  	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
  };

include/uapi/linux/nfsd_netlink.h +9 -0

+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+

 enum {
  NFSD_CMD_RPC_STATUS_GET = 1,
  NFSD_CMD_THREADS_SET,
  NFSD_CMD_THREADS_GET,

include/uapi/linux/nfsd_netlink.h +2 -0

+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,

  __NFSD_CMD_MAX,
  NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +2 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
  };

 const char *nfsd_op_str(int op)

tools/net/ynl/generated/nfsd-user.c +0 -0

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
  	.table = nfsd_server_worker_policy,
  };

tools/net/ynl/generated/nfsd-user.c +11 -0

+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+

 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */ /* NFSD_CMD_RPC_STATUS_GET - dump */

tools/net/ynl/generated/nfsd-user.c +0 -0

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
  	return NULL;
  }

tools/net/ynl/generated/nfsd-user.c +68 -0

+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+

 const struct ynl_family ynl_nfsd_family = {
  .name = "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +0 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
   */
  struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);

tools/net/ynl/generated/nfsd-user.h +4 -0

+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

Quoted 3 lines

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Ack. So far I have just converted the current implementation to netlink and I have not changed any logic. Anyway I am fine to change the current logic. Should we have 2 rpc.nfsd version in this case?

Quoted 48 lines

Quoted 42 lines

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+

 #endif /* _LINUX_NFSD_GEN_H */

Signature · 1 line

Jeff Layton <[email protected]>

Quoted 372 lines · Lorenzo Bianconi

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Quoted 42 lines

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NFSD_GEN_H */

Signature · 1 line

Jeff Layton <[email protected]>

Quoted 396 lines · Lorenzo Bianconi

Quoted 372 lines

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

Quoted 3 lines

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Jeff and Lorenzo, this sounds to me like a useful and narrow improvement to this interface, one that should be implemented as part of this patch series.

Ditto for Jeff's review comment on 3/3.

Quoted 46 lines

Quoted 42 lines

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NFSD_GEN_H */

Signature · 1 line

Jeff Layton <[email protected]>

Signature · 1 line

Chuck Lever

Quoted 401 lines · Jeff Layton

Quoted 399 lines · Lorenzo Bianconi

Quoted 372 lines

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Quoted 3 lines

Jeff and Lorenzo, this sounds to me like a useful and narrow improvement to this interface, one that should be implemented as part of this patch series.

ack, I am fine with it, I will work on patch 2/3 and 3/3. @Chuck: am I suppose to respin patch 1/3 too?

Regards,
Lorenzo

Quoted 53 lines

Ditto for Jeff's review comment on 3/3.

Quoted 46 lines

Quoted 42 lines

tools/net/ynl/generated/nfsd-user.h +41 -0

+static inline struct nfsd_version_set_req *nfsd_version_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct nfsd_version_set_req));
+}
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req);
+
+static inline void
+nfsd_version_set_req_set_major(struct nfsd_version_set_req *req, __u32 major)
+{
+	req->_present.major = 1;
+	req->major = major;
+}
+static inline void
+nfsd_version_set_req_set_minor(struct nfsd_version_set_req *req, __u32 minor)
+{
+	req->_present.minor = 1;
+	req->minor = minor;
+}
+static inline void
+nfsd_version_set_req_set_status(struct nfsd_version_set_req *req, __u8 status)
+{
+	req->_present.status = 1;
+	req->status = status;
+}
+
+/*
+ * enable/disable server version
+ */
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req);
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+struct nfsd_version_get_list {
+	struct nfsd_version_get_list *next;
+	struct nfsd_version_get_rsp obj __attribute__ ((aligned (8)));
+};
+
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp);
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NFSD_GEN_H */

Signature · 1 line

Jeff Layton <[email protected]>

Signature · 1 line

Chuck Lever

Quoted 405 lines · Lorenzo Bianconi

Quoted 404 lines · Jeff Layton

Quoted 396 lines · Lorenzo Bianconi

Quoted 372 lines

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

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 Documentation/netlink/specs/nfsd.yaml |  32 ++++++++
 fs/nfsd/netlink.c                     |  19 +++++
 fs/nfsd/netlink.h                     |   3 +
 fs/nfsd/nfsctl.c                      | 105 ++++++++++++++++++++++++++
 include/uapi/linux/nfsd_netlink.h     |  11 +++
 tools/net/ynl/generated/nfsd-user.c   |  81 ++++++++++++++++++++
 tools/net/ynl/generated/nfsd-user.h   |  55 ++++++++++++++
 7 files changed, 306 insertions(+)

Documentation/netlink/specs/nfsd.yaml +32 -0

index c92e1425d316..6c5e42bb20f6 100644
@@ -68,6 +68,18 @@ attribute-sets:
       -
         name: threads
         type: u32
+  -
+    name: server-version
+    attributes:
+      -
+        name: major
+        type: u32
+      -
+        name: minor
+        type: u32
+      -
+        name: status
+        type: u8
 
 operations:
   list:

@@ -110,3 +122,23 @@ operations:
         reply:
           attributes:
             - threads
+    -
+      name: version-set
+      doc: enable/disable server version
+      attribute-set: server-version
+      flags: [ admin-perm ]
+      do:
+        request:
+          attributes:
+            - major
+            - minor
+            - status
+    -
+      name: version-get
+      doc: dump server versions
+      attribute-set: server-version
+      dump:
+        reply:
+          attributes:
+            - major
+            - minor

fs/nfsd/netlink.c +19 -0

index 1a59a8e6c7e2..0608a7bd193b 100644
@@ -15,6 +15,13 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_WORKER_T
 	[NFSD_A_SERVER_WORKER_THREADS] = { .type = NLA_U32, },
 };
 
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_VERSION_STATUS + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .type = NLA_U8, },
+};
+
 /* Ops table for nfsd */
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{

@@ -36,6 +43,18 @@ static const struct genl_split_ops nfsd_nl_ops[] = {
 		.doit	= nfsd_nl_threads_get_doit,
 		.flags	= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_VERSION_STATUS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.dumpit	= nfsd_nl_version_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h +3 -0

index 4137fac477e4..7d203cec08e4 100644
@@ -18,6 +18,9 @@ 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);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb);
 
 extern struct genl_family nfsd_nl_family;
 

fs/nfsd/nfsctl.c +105 -0

index 130b3d937a79..f04430f79687 100644
@@ -1757,6 +1757,111 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+/**
+ * nfsd_nl_version_set_doit - enable/disable the provided nfs server version
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id);
+	enum vers_op cmd;
+	u32 major, minor;
+	u8 status;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MAJOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_MINOR) ||
+	    GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_VERSION_STATUS))
+		return -EINVAL;
+
+	major = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MAJOR]);
+	minor = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_MINOR]);
+
+	status = nla_get_u32(info->attrs[NFSD_A_SERVER_VERSION_STATUS]);
+	cmd = !!status ? NFSD_SET : NFSD_CLEAR;
+
+	mutex_lock(&nfsd_mutex);
+	switch (major) {
+	case 4:
+		ret = nfsd_minorversion(nn, minor, cmd);
+		break;
+	case 2:
+	case 3:
+		if (!minor) {
+			ret = nfsd_vers(nn, major, cmd);
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_version_get_doit - Handle verion_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_version_get_dumpit(struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	int i, ret = -ENOMEM;
+
+	mutex_lock(&nfsd_mutex);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		if (!nfsd_vers(nn, i, NFSD_AVAIL))
+			continue;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			void *hdr;
+
+			if (!nfsd_vers(nn, i, NFSD_TEST))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			if (i == 4 && !nfsd_minorversion(nn, j, NFSD_TEST))
+				continue;
+
+			hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+					  0, NFSD_CMD_VERSION_GET);
+			if (!hdr)
+				goto out;
+
+			if (nla_put_u32(skb, NFSD_A_SERVER_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_SERVER_VERSION_MINOR, j))
+				goto out;
+
+			genlmsg_end(skb, hdr);
+		}
+	}
+	cb->args[0] = i;
+	ret = skb->len;
+out:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
 /**
  * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
  * @net: a freshly-created network namespace

include/uapi/linux/nfsd_netlink.h +11 -0

index 1b6fe1f9ed0e..1b3340f31baa 100644
@@ -36,10 +36,21 @@ enum {
 	NFSD_A_SERVER_WORKER_MAX = (__NFSD_A_SERVER_WORKER_MAX - 1)
 };
 
+enum {
+	NFSD_A_SERVER_VERSION_MAJOR = 1,
+	NFSD_A_SERVER_VERSION_MINOR,
+	NFSD_A_SERVER_VERSION_STATUS,
+
+	__NFSD_A_SERVER_VERSION_MAX,
+	NFSD_A_SERVER_VERSION_MAX = (__NFSD_A_SERVER_VERSION_MAX - 1)
+};
+
 enum {
 	NFSD_CMD_RPC_STATUS_GET = 1,
 	NFSD_CMD_THREADS_SET,
 	NFSD_CMD_THREADS_GET,
+	NFSD_CMD_VERSION_SET,
+	NFSD_CMD_VERSION_GET,
 
 	__NFSD_CMD_MAX,
 	NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1)

tools/net/ynl/generated/nfsd-user.c +81 -0

index 9768328a7751..4cb71c3cd18d 100644
@@ -17,6 +17,8 @@ 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",
+	[NFSD_CMD_VERSION_SET] = "version-set",
+	[NFSD_CMD_VERSION_GET] = "version-get",
 };
 
 const char *nfsd_op_str(int op)

@@ -58,6 +60,17 @@ struct ynl_policy_nest nfsd_server_worker_nest = {
 	.table = nfsd_server_worker_policy,
 };
 
+struct ynl_policy_attr nfsd_server_version_policy[NFSD_A_SERVER_VERSION_MAX + 1] = {
+	[NFSD_A_SERVER_VERSION_MAJOR] = { .name = "major", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_MINOR] = { .name = "minor", .type = YNL_PT_U32, },
+	[NFSD_A_SERVER_VERSION_STATUS] = { .name = "status", .type = YNL_PT_U8, },
+};
+
+struct ynl_policy_nest nfsd_server_version_nest = {
+	.max_attr = NFSD_A_SERVER_VERSION_MAX,
+	.table = nfsd_server_version_policy,
+};
+
 /* Common nested types */
 /* ============== NFSD_CMD_RPC_STATUS_GET ============== */
 /* NFSD_CMD_RPC_STATUS_GET - dump */

@@ -290,6 +303,74 @@ struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys)
 	return NULL;
 }
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+void nfsd_version_set_req_free(struct nfsd_version_set_req *req)
+{
+	free(req);
+}
+
+int nfsd_version_set(struct ynl_sock *ys, struct nfsd_version_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NFSD_CMD_VERSION_SET, 1);
+	ys->req_policy = &nfsd_server_version_nest;
+
+	if (req->_present.major)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MAJOR, req->major);
+	if (req->_present.minor)
+		mnl_attr_put_u32(nlh, NFSD_A_SERVER_VERSION_MINOR, req->minor);
+	if (req->_present.status)
+		mnl_attr_put_u8(nlh, NFSD_A_SERVER_VERSION_STATUS, req->status);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
+/* ============== NFSD_CMD_VERSION_GET ============== */
+/* NFSD_CMD_VERSION_GET - dump */
+void nfsd_version_get_list_free(struct nfsd_version_get_list *rsp)
+{
+	struct nfsd_version_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct nfsd_version_get_list *nfsd_version_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct nfsd_version_get_list);
+	yds.cb = nfsd_version_get_rsp_parse;
+	yds.rsp_cmd = NFSD_CMD_VERSION_GET;
+	yds.rsp_policy = &nfsd_server_version_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NFSD_CMD_VERSION_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	nfsd_version_get_list_free(yds.first);
+	return NULL;
+}
+
 const struct ynl_family ynl_nfsd_family =  {
 	.name		= "nfsd",
 };

tools/net/ynl/generated/nfsd-user.h +4 -0

index e162a4f20d91..e61c5a9e46fb 100644
@@ -111,4 +111,59 @@ void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp);
  */
 struct nfsd_threads_get_rsp *nfsd_threads_get(struct ynl_sock *ys);
 
+/* ============== NFSD_CMD_VERSION_SET ============== */
+/* NFSD_CMD_VERSION_SET - do */
+struct nfsd_version_set_req {
+	struct {

tools/net/ynl/generated/nfsd-user.h void nfsd_threads_get_rsp_free(struct nfsd_threads_get_rsp *rsp); · line 127

Quoted 10 lines

tools/net/ynl/generated/nfsd-user.h +10 -0

+		__u32 major:1;
+		__u32 minor:1;
+		__u32 status:1;
+	} _present;
+
+	__u32 major;
+	__u32 minor;
+	__u8 status;
+};
+

This more or less mirrors how the "versions" file works today, but that interface is quite klunky.  We don't have a use case that requires that we do this piecemeal like this. I think we'd be better served with a more declarative interface that reconfigures the supported versions in one shot:

Instead of having "major,minor,status" and potentially having to call this command several times from userland, it seems like it would be nicer to just have userland send down a list "major,minor" that should be enabled, and then just let the kernel figure out whether to enable or disable each. An empty list could mean "disable everything".

Quoted 3 lines

That's simpler to reason out as an interface from userland too. Trying to keep track of the enabled and disabled versions and twiddle it is really tricky in rpc.nfsd today.

Jeff and Lorenzo, this sounds to me like a useful and narrow improvement to this interface, one that should be implemented as part of this patch series.