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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
37#define CONFIGFS_MAGIC 0x62656570
38
39struct vfsmount * configfs_mount = NULL;
40struct super_block * configfs_sb = NULL;
41struct kmem_cache *configfs_dir_cachep;
42static int configfs_mnt_count = 0;
43
44static const struct super_operations configfs_ops = {
45 .statfs = simple_statfs,
46 .drop_inode = generic_delete_inode,
47};
48
49static struct config_group configfs_root_group = {
50 .cg_item = {
51 .ci_namebuf = "root",
52 .ci_name = configfs_root_group.cg_item.ci_namebuf,
53 },
54};
55
56int configfs_is_root(struct config_item *item)
57{
58 return item == &configfs_root_group.cg_item;
59}
60
61static struct configfs_dirent configfs_root = {
62 .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
63 .s_children = LIST_HEAD_INIT(configfs_root.s_children),
64 .s_element = &configfs_root_group.cg_item,
65 .s_type = CONFIGFS_ROOT,
66 .s_iattr = NULL,
67};
68
69static int configfs_fill_super(struct super_block *sb, void *data, int silent)
70{
71 struct inode *inode;
72 struct dentry *root;
73
74 sb->s_blocksize = PAGE_CACHE_SIZE;
75 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
76 sb->s_magic = CONFIGFS_MAGIC;
77 sb->s_op = &configfs_ops;
78 sb->s_time_gran = 1;
79 configfs_sb = sb;
80
81 inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
82 &configfs_root);
83 if (inode) {
84 inode->i_op = &configfs_dir_inode_operations;
85 inode->i_fop = &configfs_dir_operations;
86
87 inc_nlink(inode);
88 } else {
89 pr_debug("configfs: could not get root inode\n");
90 return -ENOMEM;
91 }
92
93 root = d_alloc_root(inode);
94 if (!root) {
95 pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
96 iput(inode);
97 return -ENOMEM;
98 }
99 config_group_init(&configfs_root_group);
100 configfs_root_group.cg_item.ci_dentry = root;
101 root->d_fsdata = &configfs_root;
102 sb->s_root = root;
103 return 0;
104}
105
106static int configfs_get_sb(struct file_system_type *fs_type,
107 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
108{
109 return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt);
110}
111
112static struct file_system_type configfs_fs_type = {
113 .owner = THIS_MODULE,
114 .name = "configfs",
115 .get_sb = configfs_get_sb,
116 .kill_sb = kill_litter_super,
117};
118
119int configfs_pin_fs(void)
120{
121 return simple_pin_fs(&configfs_fs_type, &configfs_mount,
122 &configfs_mnt_count);
123}
124
125void configfs_release_fs(void)
126{
127 simple_release_fs(&configfs_mount, &configfs_mnt_count);
128}
129
130
131static decl_subsys(config, NULL, NULL);
132
133static int __init configfs_init(void)
134{
135 int err = -ENOMEM;
136
137 configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
138 sizeof(struct configfs_dirent),
139 0, 0, NULL);
140 if (!configfs_dir_cachep)
141 goto out;
142
143 kobj_set_kset_s(&config_subsys, kernel_subsys);
144 err = subsystem_register(&config_subsys);
145 if (err) {
146 kmem_cache_destroy(configfs_dir_cachep);
147 configfs_dir_cachep = NULL;
148 goto out;
149 }
150
151 err = register_filesystem(&configfs_fs_type);
152 if (err) {
153 printk(KERN_ERR "configfs: Unable to register filesystem!\n");
154 subsystem_unregister(&config_subsys);
155 kmem_cache_destroy(configfs_dir_cachep);
156 configfs_dir_cachep = NULL;
157 goto out;
158 }
159
160 err = configfs_inode_init();
161 if (err) {
162 unregister_filesystem(&configfs_fs_type);
163 subsystem_unregister(&config_subsys);
164 kmem_cache_destroy(configfs_dir_cachep);
165 configfs_dir_cachep = NULL;
166 }
167out:
168 return err;
169}
170
171static void __exit configfs_exit(void)
172{
173 unregister_filesystem(&configfs_fs_type);
174 subsystem_unregister(&config_subsys);
175 kmem_cache_destroy(configfs_dir_cachep);
176 configfs_dir_cachep = NULL;
177 configfs_inode_exit();
178}
179
180MODULE_AUTHOR("Oracle");
181MODULE_LICENSE("GPL");
182MODULE_VERSION("0.0.2");
183MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
184
185module_init(configfs_init);
186module_exit(configfs_exit);
187
