blob: 1a2f6f6a4d917da58791d8f1287f29a90e14bed1 [file] [log] [blame]
Joel Becker7063fbf2005-12-15 14:29:43 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * mount.c - operations for initializing and mounting configfs.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 *
21 * Based on sysfs:
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
23 *
24 * configfs Copyright (C) 2005 Oracle. All rights reserved.
25 */
26
27#include <linux/fs.h>
28#include <linux/module.h>
29#include <linux/mount.h>
30#include <linux/pagemap.h>
31#include <linux/init.h>
32
33#include <linux/configfs.h>
34#include "configfs_internal.h"
35
36/* Random magic number */
37#define CONFIGFS_MAGIC 0x62656570
38
39struct vfsmount * configfs_mount = NULL;
40struct super_block * configfs_sb = NULL;
41static int configfs_mnt_count = 0;
42
43static struct super_operations configfs_ops = {
44 .statfs = simple_statfs,
45 .drop_inode = generic_delete_inode,
46};
47
48static struct config_group configfs_root_group = {
49 .cg_item = {
50 .ci_namebuf = "root",
51 .ci_name = configfs_root_group.cg_item.ci_namebuf,
52 },
53};
54
55int configfs_is_root(struct config_item *item)
56{
57 return item == &configfs_root_group.cg_item;
58}
59
60static struct configfs_dirent configfs_root = {
61 .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
62 .s_children = LIST_HEAD_INIT(configfs_root.s_children),
63 .s_element = &configfs_root_group.cg_item,
64 .s_type = CONFIGFS_ROOT,
65};
66
67static int configfs_fill_super(struct super_block *sb, void *data, int silent)
68{
69 struct inode *inode;
70 struct dentry *root;
71
72 sb->s_blocksize = PAGE_CACHE_SIZE;
73 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
74 sb->s_magic = CONFIGFS_MAGIC;
75 sb->s_op = &configfs_ops;
76 configfs_sb = sb;
77
78 inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
79 if (inode) {
80 inode->i_op = &configfs_dir_inode_operations;
81 inode->i_fop = &configfs_dir_operations;
82 /* directory inodes start off with i_nlink == 2 (for "." entry) */
83 inode->i_nlink++;
84 } else {
85 pr_debug("configfs: could not get root inode\n");
86 return -ENOMEM;
87 }
88
89 root = d_alloc_root(inode);
90 if (!root) {
91 pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
92 iput(inode);
93 return -ENOMEM;
94 }
95 config_group_init(&configfs_root_group);
96 configfs_root_group.cg_item.ci_dentry = root;
97 root->d_fsdata = &configfs_root;
98 sb->s_root = root;
99 return 0;
100}
101
102static struct super_block *configfs_get_sb(struct file_system_type *fs_type,
103 int flags, const char *dev_name, void *data)
104{
105 return get_sb_single(fs_type, flags, data, configfs_fill_super);
106}
107
108static struct file_system_type configfs_fs_type = {
109 .owner = THIS_MODULE,
110 .name = "configfs",
111 .get_sb = configfs_get_sb,
112 .kill_sb = kill_litter_super,
113};
114
115int configfs_pin_fs(void)
116{
117 return simple_pin_fs("configfs", &configfs_mount,
118 &configfs_mnt_count);
119}
120
121void configfs_release_fs(void)
122{
123 simple_release_fs(&configfs_mount, &configfs_mnt_count);
124}
125
126
127static decl_subsys(config, NULL, NULL);
128
129static int __init configfs_init(void)
130{
131 int err;
132
133 kset_set_kset_s(&config_subsys, kernel_subsys);
134 err = subsystem_register(&config_subsys);
135 if (err)
136 return err;
137
138 err = register_filesystem(&configfs_fs_type);
139 if (err) {
140 printk(KERN_ERR "configfs: Unable to register filesystem!\n");
141 subsystem_unregister(&config_subsys);
142 }
143
144 return err;
145}
146
147static void __exit configfs_exit(void)
148{
149 unregister_filesystem(&configfs_fs_type);
150 subsystem_unregister(&config_subsys);
151}
152
153MODULE_AUTHOR("Oracle");
154MODULE_LICENSE("GPL");
155MODULE_VERSION("0.0.1");
156MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
157
158module_init(configfs_init);
159module_exit(configfs_exit);