summaryrefslogtreecommitdiff
path: root/fs/nfs/sysfs.c
blob: a6f740366963100b24a8fd8d6cdac139385283b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
// 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 "nfs4_fs.h"
#include "netns.h"
#include "sysfs.h"

struct kobject *nfs_client_kobj;
static struct kset *nfs_client_kset;

static void nfs_netns_object_release(struct kobject *kobj)
{
	kfree(kobj);
}

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

static struct kobj_type nfs_netns_object_type = {
	.release = nfs_netns_object_release,
	.sysfs_ops = &kobj_sysfs_ops,
	.child_ns_type = nfs_netns_object_child_ns_type,
};

static struct kobject *nfs_netns_object_alloc(const char *name,
		struct kset *kset, struct kobject *parent)
{
	struct kobject *kobj;

	kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
	if (kobj) {
		kobj->kset = kset;
		if (kobject_init_and_add(kobj, &nfs_netns_object_type,
					parent, "%s", name) == 0)
			return kobj;
		kobject_put(kobj);
	}
	return NULL;
}

int nfs_sysfs_init(void)
{
	nfs_client_kset = kset_create_and_add("nfs", NULL, fs_kobj);
	if (!nfs_client_kset)
		return -ENOMEM;
	nfs_client_kobj = nfs_netns_object_alloc("net", nfs_client_kset, NULL);
	if  (!nfs_client_kobj) {
		kset_unregister(nfs_client_kset);
		nfs_client_kset = NULL;
		return -ENOMEM;
	}
	return 0;
}

void nfs_sysfs_exit(void)
{
	kobject_put(nfs_client_kobj);
	kset_unregister(nfs_client_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 = scnprintf(buf, PAGE_SIZE, "%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));
	kfree(c);
}

static const void *nfs_netns_client_namespace(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 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_client_kset;
		if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
					parent, "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_client_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);
		netns->nfs_client = NULL;
	}
}