1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2019 Hammerspace Inc
4 */
5
6#include <linux/module.h>
7#include <linux/kobject.h>
8#include <linux/sysfs.h>
9#include <linux/fs.h>
10#include <linux/slab.h>
11#include <linux/netdevice.h>
12#include <linux/string.h>
13#include <linux/nfs_fs.h>
14#include <linux/rcupdate.h>
15#include <linux/lockd/lockd.h>
16
17#include "nfs4_fs.h"
18#include "netns.h"
19#include "sysfs.h"
20
21static struct kset *nfs_kset;
22
23static void nfs_kset_release(struct kobject *kobj)
24{
25	struct kset *kset = container_of(kobj, struct kset, kobj);
26	kfree(kset);
27}
28
29static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type(
30		const struct kobject *kobj)
31{
32	return &net_ns_type_operations;
33}
34
35static struct kobj_type nfs_kset_type = {
36	.release = nfs_kset_release,
37	.sysfs_ops = &kobj_sysfs_ops,
38	.child_ns_type = nfs_netns_object_child_ns_type,
39};
40
41int nfs_sysfs_init(void)
42{
43	int ret;
44
45	nfs_kset = kzalloc(sizeof(*nfs_kset), GFP_KERNEL);
46	if (!nfs_kset)
47		return -ENOMEM;
48
49	ret = kobject_set_name(&nfs_kset->kobj, "nfs");
50	if (ret) {
51		kfree(nfs_kset);
52		return ret;
53	}
54
55	nfs_kset->kobj.parent = fs_kobj;
56	nfs_kset->kobj.ktype = &nfs_kset_type;
57	nfs_kset->kobj.kset = NULL;
58
59	ret = kset_register(nfs_kset);
60	if (ret) {
61		kfree(nfs_kset);
62		return ret;
63	}
64
65	return 0;
66}
67
68void nfs_sysfs_exit(void)
69{
70	kset_unregister(nfs_kset);
71}
72
73static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
74		struct kobj_attribute *attr, char *buf)
75{
76	struct nfs_netns_client *c = container_of(kobj,
77			struct nfs_netns_client,
78			kobject);
79	ssize_t ret;
80
81	rcu_read_lock();
82	ret = sysfs_emit(buf, "%s\n", rcu_dereference(c->identifier));
83	rcu_read_unlock();
84	return ret;
85}
86
87/* Strip trailing '\n' */
88static size_t nfs_string_strip(const char *c, size_t len)
89{
90	while (len > 0 && c[len-1] == '\n')
91		--len;
92	return len;
93}
94
95static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
96		struct kobj_attribute *attr,
97		const char *buf, size_t count)
98{
99	struct nfs_netns_client *c = container_of(kobj,
100			struct nfs_netns_client,
101			kobject);
102	const char *old;
103	char *p;
104	size_t len;
105
106	len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
107	if (!len)
108		return 0;
109	p = kmemdup_nul(buf, len, GFP_KERNEL);
110	if (!p)
111		return -ENOMEM;
112	old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1);
113	if (old) {
114		synchronize_rcu();
115		kfree(old);
116	}
117	return count;
118}
119
120static void nfs_netns_client_release(struct kobject *kobj)
121{
122	struct nfs_netns_client *c = container_of(kobj,
123			struct nfs_netns_client,
124			kobject);
125
126	kfree(rcu_dereference_raw(c->identifier));
127}
128
129static const void *nfs_netns_client_namespace(const struct kobject *kobj)
130{
131	return container_of(kobj, struct nfs_netns_client, kobject)->net;
132}
133
134static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
135		0644, nfs_netns_identifier_show, nfs_netns_identifier_store);
136
137static struct attribute *nfs_netns_client_attrs[] = {
138	&nfs_netns_client_id.attr,
139	NULL,
140};
141ATTRIBUTE_GROUPS(nfs_netns_client);
142
143static struct kobj_type nfs_netns_client_type = {
144	.release = nfs_netns_client_release,
145	.default_groups = nfs_netns_client_groups,
146	.sysfs_ops = &kobj_sysfs_ops,
147	.namespace = nfs_netns_client_namespace,
148};
149
150static void nfs_netns_object_release(struct kobject *kobj)
151{
152	struct nfs_netns_client *c = container_of(kobj,
153			struct nfs_netns_client,
154			nfs_net_kobj);
155	kfree(c);
156}
157
158static const void *nfs_netns_namespace(const struct kobject *kobj)
159{
160	return container_of(kobj, struct nfs_netns_client, nfs_net_kobj)->net;
161}
162
163static struct kobj_type nfs_netns_object_type = {
164	.release = nfs_netns_object_release,
165	.sysfs_ops = &kobj_sysfs_ops,
166	.namespace =  nfs_netns_namespace,
167};
168
169static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent,
170		struct net *net)
171{
172	struct nfs_netns_client *p;
173
174	p = kzalloc(sizeof(*p), GFP_KERNEL);
175	if (p) {
176		p->net = net;
177		p->kobject.kset = nfs_kset;
178		p->nfs_net_kobj.kset = nfs_kset;
179
180		if (kobject_init_and_add(&p->nfs_net_kobj, &nfs_netns_object_type,
181					parent, "net") != 0) {
182			kobject_put(&p->nfs_net_kobj);
183			return NULL;
184		}
185
186		if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
187					&p->nfs_net_kobj, "nfs_client") == 0)
188			return p;
189
190		kobject_put(&p->kobject);
191	}
192	return NULL;
193}
194
195void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net)
196{
197	struct nfs_netns_client *clp;
198
199	clp = nfs_netns_client_alloc(&nfs_kset->kobj, net);
200	if (clp) {
201		netns->nfs_client = clp;
202		kobject_uevent(&clp->kobject, KOBJ_ADD);
203	}
204}
205
206void nfs_netns_sysfs_destroy(struct nfs_net *netns)
207{
208	struct nfs_netns_client *clp = netns->nfs_client;
209
210	if (clp) {
211		kobject_uevent(&clp->kobject, KOBJ_REMOVE);
212		kobject_del(&clp->kobject);
213		kobject_put(&clp->kobject);
214		kobject_del(&clp->nfs_net_kobj);
215		kobject_put(&clp->nfs_net_kobj);
216		netns->nfs_client = NULL;
217	}
218}
219
220static bool shutdown_match_client(const struct rpc_task *task, const void *data)
221{
222	return true;
223}
224
225static void shutdown_client(struct rpc_clnt *clnt)
226{
227	clnt->cl_shutdown = 1;
228	rpc_cancel_tasks(clnt, -EIO, shutdown_match_client, NULL);
229}
230
231static ssize_t
232shutdown_show(struct kobject *kobj, struct kobj_attribute *attr,
233				char *buf)
234{
235	struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
236	bool shutdown = server->flags & NFS_MOUNT_SHUTDOWN;
237	return sysfs_emit(buf, "%d\n", shutdown);
238}
239
240static ssize_t
241shutdown_store(struct kobject *kobj, struct kobj_attribute *attr,
242				const char *buf, size_t count)
243{
244	struct nfs_server *server;
245	int ret, val;
246
247	server = container_of(kobj, struct nfs_server, kobj);
248
249	ret = kstrtoint(buf, 0, &val);
250	if (ret)
251		return ret;
252
253	if (val != 1)
254		return -EINVAL;
255
256	/* already shut down? */
257	if (server->flags & NFS_MOUNT_SHUTDOWN)
258		goto out;
259
260	server->flags |= NFS_MOUNT_SHUTDOWN;
261	shutdown_client(server->client);
262	shutdown_client(server->nfs_client->cl_rpcclient);
263
264	if (!IS_ERR(server->client_acl))
265		shutdown_client(server->client_acl);
266
267	if (server->nlm_host)
268		shutdown_client(server->nlm_host->h_rpcclnt);
269out:
270	return count;
271}
272
273static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);
274
275#define RPC_CLIENT_NAME_SIZE 64
276
277void nfs_sysfs_link_rpc_client(struct nfs_server *server,
278			struct rpc_clnt *clnt, const char *uniq)
279{
280	char name[RPC_CLIENT_NAME_SIZE];
281	int ret;
282
283	strcpy(name, clnt->cl_program->name);
284	strcat(name, uniq ? uniq : "");
285	strcat(name, "_client");
286
287	ret = sysfs_create_link_nowarn(&server->kobj,
288						&clnt->cl_sysfs->kobject, name);
289	if (ret < 0)
290		pr_warn("NFS: can't create link to %s in sysfs (%d)\n",
291			name, ret);
292}
293EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client);
294
295static void nfs_sysfs_sb_release(struct kobject *kobj)
296{
297	/* no-op: why? see lib/kobject.c kobject_cleanup() */
298}
299
300static const void *nfs_netns_server_namespace(const struct kobject *kobj)
301{
302	return container_of(kobj, struct nfs_server, kobj)->nfs_client->cl_net;
303}
304
305static struct kobj_type nfs_sb_ktype = {
306	.release = nfs_sysfs_sb_release,
307	.sysfs_ops = &kobj_sysfs_ops,
308	.namespace = nfs_netns_server_namespace,
309	.child_ns_type = nfs_netns_object_child_ns_type,
310};
311
312void nfs_sysfs_add_server(struct nfs_server *server)
313{
314	int ret;
315
316	ret = kobject_init_and_add(&server->kobj, &nfs_sb_ktype,
317				&nfs_kset->kobj, "server-%d", server->s_sysfs_id);
318	if (ret < 0) {
319		pr_warn("NFS: nfs sysfs add server-%d failed (%d)\n",
320					server->s_sysfs_id, ret);
321		return;
322	}
323	ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_shutdown.attr,
324				nfs_netns_server_namespace(&server->kobj));
325	if (ret < 0)
326		pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
327			server->s_sysfs_id, ret);
328}
329EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);
330
331void nfs_sysfs_move_server_to_sb(struct super_block *s)
332{
333	struct nfs_server *server = s->s_fs_info;
334	int ret;
335
336	ret = kobject_rename(&server->kobj, s->s_id);
337	if (ret < 0)
338		pr_warn("NFS: rename sysfs %s failed (%d)\n",
339					server->kobj.name, ret);
340}
341
342void nfs_sysfs_move_sb_to_server(struct nfs_server *server)
343{
344	const char *s;
345	int ret = -ENOMEM;
346
347	s = kasprintf(GFP_KERNEL, "server-%d", server->s_sysfs_id);
348	if (s) {
349		ret = kobject_rename(&server->kobj, s);
350		kfree(s);
351	}
352	if (ret < 0)
353		pr_warn("NFS: rename sysfs %s failed (%d)\n",
354					server->kobj.name, ret);
355}
356
357/* unlink, not dec-ref */
358void nfs_sysfs_remove_server(struct nfs_server *server)
359{
360	kobject_del(&server->kobj);
361}
362