Commit 5a939bea authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Chuck Lever
Browse files

NFSD: add write_version to netlink command 



Introduce write_version netlink command through a "declarative" interface.
This patch introduces a change in behavior since for version-set userspace
is expected to provide a NFS major/minor version list it wants to enable
while all the other ones will be disabled. (procfs write_version
command implements imperative interface where the admin writes +3/-3 to
enable/disable a single version.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Tested-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 924f4fb0

Documentation/netlink/specs/nfsd.yaml

+37 −0
Original line number Diff line number Diff line
@@ -78,6 +78,26 @@ attribute-sets: 
      -

        name: scope

        type: string

  -

    name: version

    attributes:

      -

        name: major

        type: u32

      -

        name: minor

        type: u32

      -

        name: enabled

        type: flag

  -

    name: server-proto

    attributes:

      -

        name: version

        type: nest

        nested-attributes: version

        multi-attr: true



operations:

  list:
@@ -126,3 +146,20 @@ operations: 
            - gracetime

            - leasetime

            - scope

    -

      name: version-set

      doc: set nfs enabled versions

      attribute-set: server-proto

      flags: [ admin-perm ]

      do:

        request:

          attributes:

            - version

    -

      name: version-get

      doc: get nfs enabled versions

      attribute-set: server-proto

      do:

        reply:

          attributes:

            - version

fs/nfsd/netlink.c

+24 −0
Original line number Diff line number Diff line
@@ -10,6 +10,13 @@ 


#include <uapi/linux/nfsd_netlink.h>



/* Common nested types */

const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1] = {

	[NFSD_A_VERSION_MAJOR] = { .type = NLA_U32, },

	[NFSD_A_VERSION_MINOR] = { .type = NLA_U32, },

	[NFSD_A_VERSION_ENABLED] = { .type = NLA_FLAG, },

};



/* NFSD_CMD_THREADS_SET - do */

static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_SCOPE + 1] = {

	[NFSD_A_SERVER_THREADS] = { .type = NLA_U32, },
@@ -18,6 +25,11 @@ static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_SCOPE + 
	[NFSD_A_SERVER_SCOPE] = { .type = NLA_NUL_STRING, },

};



/* NFSD_CMD_VERSION_SET - do */

static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_PROTO_VERSION + 1] = {

	[NFSD_A_SERVER_PROTO_VERSION] = NLA_POLICY_NESTED(nfsd_version_nl_policy),

};



/* Ops table for nfsd */

static const struct genl_split_ops nfsd_nl_ops[] = {

	{
@@ -39,6 +51,18 @@ 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_PROTO_VERSION,

		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,

	},

	{

		.cmd	= NFSD_CMD_VERSION_GET,

		.doit	= nfsd_nl_version_get_doit,

		.flags	= GENL_CMD_CAP_DO,

	},

};



struct genl_family nfsd_nl_family __ro_after_init = {

fs/nfsd/netlink.h

+5 −0
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@ 


#include <uapi/linux/nfsd_netlink.h>



/* Common nested types */

extern const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1];



int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb);

int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb);
@@ -18,6 +21,8 @@ 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_doit(struct sk_buff *skb, struct genl_info *info);



extern struct genl_family nfsd_nl_family;

fs/nfsd/netns.h

+1 −0
Original line number Diff line number Diff line
@@ -218,6 +218,7 @@ struct nfsd_net { 
/* Simple check to find out if a given net was properly initialized */

#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)



extern bool nfsd_support_version(int vers);

extern void nfsd_netns_free_versions(struct nfsd_net *nn);



extern unsigned int nfsd_net_id;

fs/nfsd/nfsctl.c

+150 −0
Original line number Diff line number Diff line
@@ -1796,6 +1796,156 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info) 
	return err;

}



/**

 * nfsd_nl_version_set_doit - set the nfs enabled versions

 * @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)

{

	const struct nlattr *attr;

	struct nfsd_net *nn;

	int i, rem;



	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_PROTO_VERSION))

		return -EINVAL;



	mutex_lock(&nfsd_mutex);



	nn = net_generic(genl_info_net(info), nfsd_net_id);

	if (nn->nfsd_serv) {

		mutex_unlock(&nfsd_mutex);

		return -EBUSY;

	}



	/* clear current supported versions. */

	nfsd_vers(nn, 2, NFSD_CLEAR);

	nfsd_vers(nn, 3, NFSD_CLEAR);

	for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)

		nfsd_minorversion(nn, i, NFSD_CLEAR);



	nlmsg_for_each_attr(attr, info->nlhdr, GENL_HDRLEN, rem) {

		struct nlattr *tb[NFSD_A_VERSION_MAX + 1];

		u32 major, minor = 0;

		bool enabled;



		if (nla_type(attr) != NFSD_A_SERVER_PROTO_VERSION)

			continue;



		if (nla_parse_nested(tb, NFSD_A_VERSION_MAX, attr,

				     nfsd_version_nl_policy, info->extack) < 0)

			continue;



		if (!tb[NFSD_A_VERSION_MAJOR])

			continue;



		major = nla_get_u32(tb[NFSD_A_VERSION_MAJOR]);

		if (tb[NFSD_A_VERSION_MINOR])

			minor = nla_get_u32(tb[NFSD_A_VERSION_MINOR]);



		enabled = nla_get_flag(tb[NFSD_A_VERSION_ENABLED]);



		switch (major) {

		case 4:

			nfsd_minorversion(nn, minor, enabled ? NFSD_SET : NFSD_CLEAR);

			break;

		case 3:

		case 2:

			if (!minor)

				nfsd_vers(nn, major, enabled ? NFSD_SET : NFSD_CLEAR);

			break;

		default:

			break;

		}

	}



	mutex_unlock(&nfsd_mutex);



	return 0;

}



/**

 * nfsd_nl_version_get_doit - get the enabled status for all supported nfs versions

 * @skb: reply buffer

 * @info: netlink metadata and command arguments

 *

 * Return 0 on success or a negative errno.

 */

int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct nfsd_net *nn;

	int i, err;

	void *hdr;



	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;

	}



	mutex_lock(&nfsd_mutex);

	nn = net_generic(genl_info_net(info), nfsd_net_id);



	for (i = 2; i <= 4; i++) {

		int j;



		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {

			struct nlattr *attr;



			/* Don't record any versions the kernel doesn't have

			 * compiled in

			 */

			if (!nfsd_support_version(i))

				continue;



			/* NFSv{2,3} does not support minor numbers */

			if (i < 4 && j)

				continue;



			attr = nla_nest_start(skb,

					      NFSD_A_SERVER_PROTO_VERSION);

			if (!attr) {

				err = -EINVAL;

				goto err_nfsd_unlock;

			}



			if (nla_put_u32(skb, NFSD_A_VERSION_MAJOR, i) ||

			    nla_put_u32(skb, NFSD_A_VERSION_MINOR, j)) {

				err = -EINVAL;

				goto err_nfsd_unlock;

			}



			/* Set the enabled flag if the version is enabled */

			if (nfsd_vers(nn, i, NFSD_TEST) &&

			    (i < 4 || nfsd_minorversion(nn, j, NFSD_TEST)) &&

			    nla_put_flag(skb, NFSD_A_VERSION_ENABLED)) {

				err = -EINVAL;

				goto err_nfsd_unlock;

			}



			nla_nest_end(skb, attr);

		}

	}



	mutex_unlock(&nfsd_mutex);

	genlmsg_end(skb, hdr);



	return genlmsg_reply(skb, info);



err_nfsd_unlock:

	mutex_unlock(&nfsd_mutex);

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