fs/nfs/sysfs.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2019 Hammerspace Inc
  */

 #include <linux/module.h>
 #include <linux/kobject.h>
 #include <linux/sysfs.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/netdevice.h>
 #include <linux/string.h>
 #include <linux/nfs_fs.h>
 #include <linux/rcupdate.h>
 #include <linux/lockd/lockd.h>

 #include "nfs4_fs.h"
 #include "netns.h"
 #include "sysfs.h"

 static struct kset *nfs_kset;

 static void nfs_kset_release(struct kobject *kobj)
 {
 	struct kset *kset = container_of(kobj, struct kset, kobj);
 	kfree(kset);
 }

 static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type(
 		const struct kobject *kobj)
 {
 	return &net_ns_type_operations;
 }

 static struct kobj_type nfs_kset_type = {
 	.release = nfs_kset_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.child_ns_type = nfs_netns_object_child_ns_type,
 };

 int nfs_sysfs_init(void)
 {
 	int ret;

 	nfs_kset = kzalloc(sizeof(*nfs_kset), GFP_KERNEL);
 	if (!nfs_kset)
 		return -ENOMEM;

 	ret = kobject_set_name(&nfs_kset->kobj, "nfs");
 	if (ret) {
 		kfree(nfs_kset);
 		return ret;
 	}

 	nfs_kset->kobj.parent = fs_kobj;
 	nfs_kset->kobj.ktype = &nfs_kset_type;
 	nfs_kset->kobj.kset = NULL;

 	ret = kset_register(nfs_kset);
 	if (ret) {
 		kfree(nfs_kset);
 		return ret;
 	}

 	return 0;
 }

 void nfs_sysfs_exit(void)
 {
 	kset_unregister(nfs_kset);
 }

 static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
 	struct nfs_netns_client *c = container_of(kobj,
 			struct nfs_netns_client,
 			kobject);
 	ssize_t ret;

 	rcu_read_lock();
 	ret = sysfs_emit(buf, "%s\n", rcu_dereference(c->identifier));
 	rcu_read_unlock();
 	return ret;
 }

 /* Strip trailing '\n' */
 static size_t nfs_string_strip(const char *c, size_t len)
 {
 	while (len > 0 && c[len-1] == '\n')
 		--len;
 	return len;
 }

 static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
 		struct kobj_attribute *attr,
 		const char *buf, size_t count)
 {
 	struct nfs_netns_client *c = container_of(kobj,
 			struct nfs_netns_client,
 			kobject);
 	const char *old;
 	char *p;
 	size_t len;

 	len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
 	if (!len)
 		return 0;
 	p = kmemdup_nul(buf, len, GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
 	old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1);
 	if (old) {
 		synchronize_rcu();
 		kfree(old);
 	}
 	return count;
 }

 static void nfs_netns_client_release(struct kobject *kobj)
 {
 	struct nfs_netns_client *c = container_of(kobj,
 			struct nfs_netns_client,
 			kobject);

 	kfree(rcu_dereference_raw(c->identifier));
 }

 static const void *nfs_netns_client_namespace(const struct kobject *kobj)
 {
 	return container_of(kobj, struct nfs_netns_client, kobject)->net;
 }

 static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
 		0644, nfs_netns_identifier_show, nfs_netns_identifier_store);

 static struct attribute *nfs_netns_client_attrs[] = {
 	&nfs_netns_client_id.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(nfs_netns_client);

 static struct kobj_type nfs_netns_client_type = {
 	.release = nfs_netns_client_release,
 	.default_groups = nfs_netns_client_groups,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace = nfs_netns_client_namespace,
 };

 static void nfs_netns_object_release(struct kobject *kobj)
 {
 	struct nfs_netns_client *c = container_of(kobj,
 			struct nfs_netns_client,
 			nfs_net_kobj);
 	kfree(c);
 }

 static const void *nfs_netns_namespace(const struct kobject *kobj)
 {
 	return container_of(kobj, struct nfs_netns_client, nfs_net_kobj)->net;
 }

 static struct kobj_type nfs_netns_object_type = {
 	.release = nfs_netns_object_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace =  nfs_netns_namespace,
 };

 static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent,
 		struct net *net)
 {
 	struct nfs_netns_client *p;

 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (p) {
 		p->net = net;
 		p->kobject.kset = nfs_kset;
 		p->nfs_net_kobj.kset = nfs_kset;

 		if (kobject_init_and_add(&p->nfs_net_kobj, &nfs_netns_object_type,
 					parent, "net") != 0) {
 			kobject_put(&p->nfs_net_kobj);
 			return NULL;
 		}

 		if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
 					&p->nfs_net_kobj, "nfs_client") == 0)
 			return p;

 		kobject_put(&p->kobject);
 	}
 	return NULL;
 }

 void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net)
 {
 	struct nfs_netns_client *clp;

 	clp = nfs_netns_client_alloc(&nfs_kset->kobj, net);
 	if (clp) {
 		netns->nfs_client = clp;
 		kobject_uevent(&clp->kobject, KOBJ_ADD);
 	}
 }

 void nfs_netns_sysfs_destroy(struct nfs_net *netns)
 {
 	struct nfs_netns_client *clp = netns->nfs_client;

 	if (clp) {
 		kobject_uevent(&clp->kobject, KOBJ_REMOVE);
 		kobject_del(&clp->kobject);
 		kobject_put(&clp->kobject);
 		kobject_del(&clp->nfs_net_kobj);
 		kobject_put(&clp->nfs_net_kobj);
 		netns->nfs_client = NULL;
 	}
 }

 static bool shutdown_match_client(const struct rpc_task *task, const void *data)
 {
 	return true;
 }

 static void shutdown_client(struct rpc_clnt *clnt)
 {
 	clnt->cl_shutdown = 1;
 	rpc_cancel_tasks(clnt, -EIO, shutdown_match_client, NULL);
 }

 static ssize_t
 shutdown_show(struct kobject *kobj, struct kobj_attribute *attr,
 				char *buf)
 {
 	struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
 	bool shutdown = server->flags & NFS_MOUNT_SHUTDOWN;
 	return sysfs_emit(buf, "%d\n", shutdown);
 }

 static ssize_t
 shutdown_store(struct kobject *kobj, struct kobj_attribute *attr,
 				const char *buf, size_t count)
 {
 	struct nfs_server *server;
 	int ret, val;

 	server = container_of(kobj, struct nfs_server, kobj);

 	ret = kstrtoint(buf, 0, &val);
 	if (ret)
 		return ret;

 	if (val != 1)
 		return -EINVAL;

 	/* already shut down? */
 	if (server->flags & NFS_MOUNT_SHUTDOWN)
 		goto out;

 	server->flags |= NFS_MOUNT_SHUTDOWN;
 	shutdown_client(server->client);
 	shutdown_client(server->nfs_client->cl_rpcclient);

 	if (!IS_ERR(server->client_acl))
 		shutdown_client(server->client_acl);

 	if (server->nlm_host)
 		shutdown_client(server->nlm_host->h_rpcclnt);
 out:
 	return count;
 }

 static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);

 #define RPC_CLIENT_NAME_SIZE 64

 void nfs_sysfs_link_rpc_client(struct nfs_server *server,
 			struct rpc_clnt *clnt, const char *uniq)
 {
 	char name[RPC_CLIENT_NAME_SIZE];
 	int ret;

 	strcpy(name, clnt->cl_program->name);
 	strcat(name, uniq ? uniq : "");
 	strcat(name, "_client");

 	ret = sysfs_create_link_nowarn(&server->kobj,
 						&clnt->cl_sysfs->kobject, name);
 	if (ret < 0)
 		pr_warn("NFS: can't create link to %s in sysfs (%d)\n",
 			name, ret);
 }
 EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client);

 static void nfs_sysfs_sb_release(struct kobject *kobj)
 {
 	/* no-op: why? see lib/kobject.c kobject_cleanup() */
 }

 static const void *nfs_netns_server_namespace(const struct kobject *kobj)
 {
 	return container_of(kobj, struct nfs_server, kobj)->nfs_client->cl_net;
 }

 static struct kobj_type nfs_sb_ktype = {
 	.release = nfs_sysfs_sb_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace = nfs_netns_server_namespace,
 	.child_ns_type = nfs_netns_object_child_ns_type,
 };

 void nfs_sysfs_add_server(struct nfs_server *server)
 {
 	int ret;

 	ret = kobject_init_and_add(&server->kobj, &nfs_sb_ktype,
 				&nfs_kset->kobj, "server-%d", server->s_sysfs_id);
 	if (ret < 0) {
 		pr_warn("NFS: nfs sysfs add server-%d failed (%d)\n",
 					server->s_sysfs_id, ret);
 		return;
 	}
 	ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_shutdown.attr,
 				nfs_netns_server_namespace(&server->kobj));
 	if (ret < 0)
 		pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
 			server->s_sysfs_id, ret);
 }
 EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);

 void nfs_sysfs_move_server_to_sb(struct super_block *s)
 {
 	struct nfs_server *server = s->s_fs_info;
 	int ret;

 	ret = kobject_rename(&server->kobj, s->s_id);
 	if (ret < 0)
 		pr_warn("NFS: rename sysfs %s failed (%d)\n",
 					server->kobj.name, ret);
 }

 void nfs_sysfs_move_sb_to_server(struct nfs_server *server)
 {
 	const char *s;
 	int ret = -ENOMEM;

 	s = kasprintf(GFP_KERNEL, "server-%d", server->s_sysfs_id);
 	if (s)
 		ret = kobject_rename(&server->kobj, s);
 	if (ret < 0)
 		pr_warn("NFS: rename sysfs %s failed (%d)\n",
 					server->kobj.name, ret);
 }

 /* unlink, not dec-ref */
 void nfs_sysfs_remove_server(struct nfs_server *server)
 {
 	kobject_del(&server->kobj);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (c) 2019 Hammerspace Inc
	*/

	#include <linux/module.h>
	#include <linux/kobject.h>
	#include <linux/sysfs.h>
	#include <linux/fs.h>
	#include <linux/slab.h>
	#include <linux/netdevice.h>
	#include <linux/string.h>
	#include <linux/nfs_fs.h>
	#include <linux/rcupdate.h>
	#include <linux/lockd/lockd.h>

	#include "nfs4_fs.h"
	#include "netns.h"
	#include "sysfs.h"

	static struct kset *nfs_kset;

	static void nfs_kset_release(struct kobject *kobj)
	{
	struct kset *kset = container_of(kobj, struct kset, kobj);
	kfree(kset);
	}

	static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type(
	const struct kobject *kobj)
	{
	return &net_ns_type_operations;
	}

	static struct kobj_type nfs_kset_type = {
	.release = nfs_kset_release,
	.sysfs_ops = &kobj_sysfs_ops,
	.child_ns_type = nfs_netns_object_child_ns_type,
	};

	int nfs_sysfs_init(void)
	{
	int ret;

	nfs_kset = kzalloc(sizeof(*nfs_kset), GFP_KERNEL);
	if (!nfs_kset)
	return -ENOMEM;

	ret = kobject_set_name(&nfs_kset->kobj, "nfs");
	if (ret) {
	kfree(nfs_kset);
	return ret;
	}

	nfs_kset->kobj.parent = fs_kobj;
	nfs_kset->kobj.ktype = &nfs_kset_type;
	nfs_kset->kobj.kset = NULL;

	ret = kset_register(nfs_kset);
	if (ret) {
	kfree(nfs_kset);
	return ret;
	}

	return 0;
	}

	void nfs_sysfs_exit(void)
	{
	kset_unregister(nfs_kset);
	}

	static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
	struct kobj_attribute attr, char buf)
	{
	struct nfs_netns_client *c = container_of(kobj,
	struct nfs_netns_client,
	kobject);
	ssize_t ret;

	rcu_read_lock();
	ret = sysfs_emit(buf, "%s\n", rcu_dereference(c->identifier));
	rcu_read_unlock();
	return ret;
	}

	/* Strip trailing '\n' */
	static size_t nfs_string_strip(const char *c, size_t len)
	{
	while (len > 0 && c[len-1] == '\n')
	--len;
	return len;
	}

	static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
	struct kobj_attribute *attr,
	const char *buf, size_t count)
	{
	struct nfs_netns_client *c = container_of(kobj,
	struct nfs_netns_client,
	kobject);
	const char *old;
	char *p;
	size_t len;

	len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
	if (!len)
	return 0;
	p = kmemdup_nul(buf, len, GFP_KERNEL);
	if (!p)
	return -ENOMEM;
	old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1);
	if (old) {
	synchronize_rcu();
	kfree(old);
	}
	return count;
	}

	static void nfs_netns_client_release(struct kobject *kobj)
	{
	struct nfs_netns_client *c = container_of(kobj,
	struct nfs_netns_client,
	kobject);

	kfree(rcu_dereference_raw(c->identifier));
	}

	static const void nfs_netns_client_namespace(const struct kobject kobj)
	{
	return container_of(kobj, struct nfs_netns_client, kobject)->net;
	}

	static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
	0644, nfs_netns_identifier_show, nfs_netns_identifier_store);

	static struct attribute *nfs_netns_client_attrs[] = {
	&nfs_netns_client_id.attr,
	NULL,
	};
	ATTRIBUTE_GROUPS(nfs_netns_client);

	static struct kobj_type nfs_netns_client_type = {
	.release = nfs_netns_client_release,
	.default_groups = nfs_netns_client_groups,
	.sysfs_ops = &kobj_sysfs_ops,
	.namespace = nfs_netns_client_namespace,
	};

	static void nfs_netns_object_release(struct kobject *kobj)
	{
	struct nfs_netns_client *c = container_of(kobj,
	struct nfs_netns_client,
	nfs_net_kobj);
	kfree(c);
	}

	static const void nfs_netns_namespace(const struct kobject kobj)
	{
	return container_of(kobj, struct nfs_netns_client, nfs_net_kobj)->net;
	}

	static struct kobj_type nfs_netns_object_type = {
	.release = nfs_netns_object_release,
	.sysfs_ops = &kobj_sysfs_ops,
	.namespace = nfs_netns_namespace,
	};

	static struct nfs_netns_client nfs_netns_client_alloc(struct kobject parent,
	struct net *net)
	{
	struct nfs_netns_client *p;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (p) {
	p->net = net;
	p->kobject.kset = nfs_kset;
	p->nfs_net_kobj.kset = nfs_kset;

	if (kobject_init_and_add(&p->nfs_net_kobj, &nfs_netns_object_type,
	parent, "net") != 0) {
	kobject_put(&p->nfs_net_kobj);
	return NULL;
	}

	if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
	&p->nfs_net_kobj, "nfs_client") == 0)
	return p;

	kobject_put(&p->kobject);
	}
	return NULL;
	}

	void nfs_netns_sysfs_setup(struct nfs_net netns, struct net net)
	{
	struct nfs_netns_client *clp;

	clp = nfs_netns_client_alloc(&nfs_kset->kobj, net);
	if (clp) {
	netns->nfs_client = clp;
	kobject_uevent(&clp->kobject, KOBJ_ADD);
	}
	}

	void nfs_netns_sysfs_destroy(struct nfs_net *netns)
	{
	struct nfs_netns_client *clp = netns->nfs_client;

	if (clp) {
	kobject_uevent(&clp->kobject, KOBJ_REMOVE);
	kobject_del(&clp->kobject);
	kobject_put(&clp->kobject);
	kobject_del(&clp->nfs_net_kobj);
	kobject_put(&clp->nfs_net_kobj);
	netns->nfs_client = NULL;
	}
	}

	static bool shutdown_match_client(const struct rpc_task task, const void data)
	{
	return true;
	}

	static void shutdown_client(struct rpc_clnt *clnt)
	{
	clnt->cl_shutdown = 1;
	rpc_cancel_tasks(clnt, -EIO, shutdown_match_client, NULL);
	}

	static ssize_t
	shutdown_show(struct kobject kobj, struct kobj_attribute attr,
	char *buf)
	{
	struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
	bool shutdown = server->flags & NFS_MOUNT_SHUTDOWN;
	return sysfs_emit(buf, "%d\n", shutdown);
	}

	static ssize_t
	shutdown_store(struct kobject kobj, struct kobj_attribute attr,
	const char *buf, size_t count)
	{
	struct nfs_server *server;
	int ret, val;

	server = container_of(kobj, struct nfs_server, kobj);

	ret = kstrtoint(buf, 0, &val);
	if (ret)
	return ret;

	if (val != 1)
	return -EINVAL;

	/* already shut down? */
	if (server->flags & NFS_MOUNT_SHUTDOWN)
	goto out;

	server->flags \|= NFS_MOUNT_SHUTDOWN;
	shutdown_client(server->client);
	shutdown_client(server->nfs_client->cl_rpcclient);

	if (!IS_ERR(server->client_acl))
	shutdown_client(server->client_acl);

	if (server->nlm_host)
	shutdown_client(server->nlm_host->h_rpcclnt);
	out:
	return count;
	}

	static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);

	#define RPC_CLIENT_NAME_SIZE 64

	void nfs_sysfs_link_rpc_client(struct nfs_server *server,
	struct rpc_clnt clnt, const char uniq)
	{
	char name[RPC_CLIENT_NAME_SIZE];
	int ret;

	strcpy(name, clnt->cl_program->name);
	strcat(name, uniq ? uniq : "");
	strcat(name, "_client");

	ret = sysfs_create_link_nowarn(&server->kobj,
	&clnt->cl_sysfs->kobject, name);
	if (ret < 0)
	pr_warn("NFS: can't create link to %s in sysfs (%d)\n",
	name, ret);
	}
	EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client);

	static void nfs_sysfs_sb_release(struct kobject *kobj)
	{
	/* no-op: why? see lib/kobject.c kobject_cleanup() */
	}

	static const void nfs_netns_server_namespace(const struct kobject kobj)
	{
	return container_of(kobj, struct nfs_server, kobj)->nfs_client->cl_net;
	}

	static struct kobj_type nfs_sb_ktype = {
	.release = nfs_sysfs_sb_release,
	.sysfs_ops = &kobj_sysfs_ops,
	.namespace = nfs_netns_server_namespace,
	.child_ns_type = nfs_netns_object_child_ns_type,
	};

	void nfs_sysfs_add_server(struct nfs_server *server)
	{
	int ret;

	ret = kobject_init_and_add(&server->kobj, &nfs_sb_ktype,
	&nfs_kset->kobj, "server-%d", server->s_sysfs_id);
	if (ret < 0) {
	pr_warn("NFS: nfs sysfs add server-%d failed (%d)\n",
	server->s_sysfs_id, ret);
	return;
	}
	ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_shutdown.attr,
	nfs_netns_server_namespace(&server->kobj));
	if (ret < 0)
	pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
	server->s_sysfs_id, ret);
	}
	EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);

	void nfs_sysfs_move_server_to_sb(struct super_block *s)
	{
	struct nfs_server *server = s->s_fs_info;
	int ret;

	ret = kobject_rename(&server->kobj, s->s_id);
	if (ret < 0)
	pr_warn("NFS: rename sysfs %s failed (%d)\n",
	server->kobj.name, ret);
	}

	void nfs_sysfs_move_sb_to_server(struct nfs_server *server)
	{
	const char *s;
	int ret = -ENOMEM;

	s = kasprintf(GFP_KERNEL, "server-%d", server->s_sysfs_id);
	if (s)
	ret = kobject_rename(&server->kobj, s);
	if (ret < 0)
	pr_warn("NFS: rename sysfs %s failed (%d)\n",
	server->kobj.name, ret);
	}

	/* unlink, not dec-ref */
	void nfs_sysfs_remove_server(struct nfs_server *server)
	{
	kobject_del(&server->kobj);
	}