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(objp: 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(size: sizeof(*nfs_kset), GFP_KERNEL);
46 if (!nfs_kset)
47 return -ENOMEM;
48
49 ret = kobject_set_name(kobj: &nfs_kset->kobj, name: "nfs");
50 if (ret) {
51 kfree(objp: 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(kset: nfs_kset);
60 if (ret) {
61 kfree(objp: nfs_kset);
62 return ret;
63 }
64
65 return 0;
66}
67
68void nfs_sysfs_exit(void)
69{
70 kset_unregister(kset: 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, fmt: "%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(c: buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
107 if (!len)
108 return 0;
109 p = kmemdup_nul(s: 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(objp: 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(objp: 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(size: 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(kobj: &p->nfs_net_kobj, ktype: &nfs_netns_object_type,
181 parent, fmt: "net") != 0) {
182 kobject_put(kobj: &p->nfs_net_kobj);
183 return NULL;
184 }
185
186 if (kobject_init_and_add(kobj: &p->kobject, ktype: &nfs_netns_client_type,
187 parent: &p->nfs_net_kobj, fmt: "nfs_client") == 0)
188 return p;
189
190 kobject_put(kobj: &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(parent: &nfs_kset->kobj, net);
200 if (clp) {
201 netns->nfs_client = clp;
202 kobject_uevent(kobj: &clp->kobject, action: 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(kobj: &clp->kobject, action: KOBJ_REMOVE);
212 kobject_del(kobj: &clp->kobject);
213 kobject_put(kobj: &clp->kobject);
214 kobject_del(kobj: &clp->nfs_net_kobj);
215 kobject_put(kobj: &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, error: -EIO, fnmatch: 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, fmt: "%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(s: buf, base: 0, res: &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(clnt: server->client);
262 shutdown_client(clnt: server->nfs_client->cl_rpcclient);
263
264 if (!IS_ERR(ptr: server->client_acl))
265 shutdown_client(clnt: server->client_acl);
266
267 if (server->nlm_host)
268 shutdown_client(clnt: 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(p: name, q: clnt->cl_program->name);
284 strcat(p: name, q: uniq ? uniq : "");
285 strcat(p: name, q: "_client");
286
287 ret = sysfs_create_link_nowarn(kobj: &server->kobj,
288 target: &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(kobj: &server->kobj, ktype: &nfs_sb_ktype,
317 parent: &nfs_kset->kobj, fmt: "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(kobj: &server->kobj, attr: &nfs_sysfs_attr_shutdown.attr,
324 ns: nfs_netns_server_namespace(kobj: &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, new_name: 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, fmt: "server-%d", server->s_sysfs_id);
348 if (s) {
349 ret = kobject_rename(&server->kobj, new_name: s);
350 kfree(objp: 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(kobj: &server->kobj);
361}
362

source code of linux/fs/nfs/sysfs.c