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
21 static struct kset *nfs_kset;
22
23 static void nfs_kset_release(struct kobject *kobj)
24 {
25 struct kset *kset = container_of(kobj, struct kset, kobj);
26 kfree(kset);
27 }
28
29 static 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
35 static 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
41 int 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
68 void nfs_sysfs_exit(void)
69 {
70 kset_unregister(nfs_kset);
71 }
72
73 static 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' */
88 static 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
95 static 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
120 static 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
129 static const void *nfs_netns_client_namespace(const struct kobject *kobj)
130 {
131 return container_of(kobj, struct nfs_netns_client, kobject)->net;
132 }
133
134 static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
135 0644, nfs_netns_identifier_show, nfs_netns_identifier_store);
136
137 static struct attribute *nfs_netns_client_attrs[] = {
138 &nfs_netns_client_id.attr,
139 NULL,
140 };
141 ATTRIBUTE_GROUPS(nfs_netns_client);
142
143 static 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
150 static 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
158 static 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
163 static 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
169 static 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
195 void 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
206 void 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
220 static bool shutdown_match_client(const struct rpc_task *task, const void *data)
221 {
222 return true;
223 }
224
225 static 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
231 static ssize_t
232 shutdown_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
240 static ssize_t
241 shutdown_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);
269 out:
270 return count;
271 }
272
273 static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);
274
275 #define RPC_CLIENT_NAME_SIZE 64
276
277 void 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 }
293 EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client);
294
295 static void nfs_sysfs_sb_release(struct kobject *kobj)
296 {
297 /* no-op: why? see lib/kobject.c kobject_cleanup() */
298 }
299
300 static 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
305 static 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
312 void 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 }
329 EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);
330
331 void 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
342 void 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 */
358 void nfs_sysfs_remove_server(struct nfs_server *server)
359 {
360 kobject_del(&server->kobj);
361 }
362
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