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
|
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* mount.c - operations for initializing and mounting configfs.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/configfs.h>
#include "configfs_internal.h"
/* Random magic number */
#define CONFIGFS_MAGIC 0x62656570
struct vfsmount * configfs_mount = NULL;
struct super_block * configfs_sb = NULL;
struct kmem_cache *configfs_dir_cachep;
static int configfs_mnt_count = 0;
static const struct super_operations configfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static struct config_group configfs_root_group = {
.cg_item = {
.ci_namebuf = "root",
.ci_name = configfs_root_group.cg_item.ci_namebuf,
},
};
int configfs_is_root(struct config_item *item)
{
return item == &configfs_root_group.cg_item;
}
static struct configfs_dirent configfs_root = {
.s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
.s_children = LIST_HEAD_INIT(configfs_root.s_children),
.s_element = &configfs_root_group.cg_item,
.s_type = CONFIGFS_ROOT,
.s_iattr = NULL,
};
static int configfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
struct dentry *root;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = CONFIGFS_MAGIC;
sb->s_op = &configfs_ops;
sb->s_time_gran = 1;
configfs_sb = sb;
inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
&configfs_root);
if (inode) {
inode->i_op = &configfs_dir_inode_operations;
inode->i_fop = &configfs_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
} else {
pr_debug("configfs: could not get root inode\n");
return -ENOMEM;
}
root = d_alloc_root(inode);
if (!root) {
pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
iput(inode);
return -ENOMEM;
}
config_group_init(&configfs_root_group);
configfs_root_group.cg_item.ci_dentry = root;
root->d_fsdata = &configfs_root;
sb->s_root = root;
return 0;
}
static int configfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt);
}
static struct file_system_type configfs_fs_type = {
.owner = THIS_MODULE,
.name = "configfs",
.get_sb = configfs_get_sb,
.kill_sb = kill_litter_super,
};
int configfs_pin_fs(void)
{
return simple_pin_fs(&configfs_fs_type, &configfs_mount,
&configfs_mnt_count);
}
void configfs_release_fs(void)
{
simple_release_fs(&configfs_mount, &configfs_mnt_count);
}
static decl_subsys(config, NULL, NULL);
static int __init configfs_init(void)
{
int err = -ENOMEM;
configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
sizeof(struct configfs_dirent),
0, 0, NULL, NULL);
if (!configfs_dir_cachep)
goto out;
kobj_set_kset_s(&config_subsys, kernel_subsys);
err = subsystem_register(&config_subsys);
if (err) {
kmem_cache_destroy(configfs_dir_cachep);
configfs_dir_cachep = NULL;
goto out;
}
err = register_filesystem(&configfs_fs_type);
if (err) {
printk(KERN_ERR "configfs: Unable to register filesystem!\n");
subsystem_unregister(&config_subsys);
kmem_cache_destroy(configfs_dir_cachep);
configfs_dir_cachep = NULL;
}
out:
return err;
}
static void __exit configfs_exit(void)
{
unregister_filesystem(&configfs_fs_type);
subsystem_unregister(&config_subsys);
kmem_cache_destroy(configfs_dir_cachep);
configfs_dir_cachep = NULL;
}
MODULE_AUTHOR("Oracle");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.0.2");
MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
module_init(configfs_init);
module_exit(configfs_exit);
|
