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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#include <linux/slab.h>
33
34#include <linux/configfs.h>
35#include "configfs_internal.h"
36
37
38#define CONFIGFS_MAGIC 0x62656570
39
40struct vfsmount * configfs_mount = NULL;
41struct super_block * configfs_sb = NULL;
42struct kmem_cache *configfs_dir_cachep;
43static int configfs_mnt_count = 0;
44
45static const struct super_operations configfs_ops = {
46 .statfs = simple_statfs,
47 .drop_inode = generic_delete_inode,
48};
49
50static struct config_group configfs_root_group = {
51 .cg_item = {
52 .ci_namebuf = "root",
53 .ci_name = configfs_root_group.cg_item.ci_namebuf,
54 },
55};
56
57int configfs_is_root(struct config_item *item)
58{
59 return item == &configfs_root_group.cg_item;
60}
61
62static struct configfs_dirent configfs_root = {
63 .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
64 .s_children = LIST_HEAD_INIT(configfs_root.s_children),
65 .s_element = &configfs_root_group.cg_item,
66 .s_type = CONFIGFS_ROOT,
67 .s_iattr = NULL,
68};
69
70static int configfs_fill_super(struct super_block *sb, void *data, int silent)
71{
72 struct inode *inode;
73 struct dentry *root;
74
75 sb->s_blocksize = PAGE_CACHE_SIZE;
76 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
77 sb->s_magic = CONFIGFS_MAGIC;
78 sb->s_op = &configfs_ops;
79 sb->s_time_gran = 1;
80 configfs_sb = sb;
81
82 inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
83 &configfs_root);
84 if (inode) {
85 inode->i_op = &configfs_dir_inode_operations;
86 inode->i_fop = &configfs_dir_operations;
87
88 inc_nlink(inode);
89 } else {
90 pr_debug("configfs: could not get root inode\n");
91 return -ENOMEM;
92 }
93
94 root = d_alloc_root(inode);
95 if (!root) {
96 pr_debug("%s: could not get root dentry!\n",__func__);
97 iput(inode);
98 return -ENOMEM;
99 }
100 config_group_init(&configfs_root_group);
101 configfs_root_group.cg_item.ci_dentry = root;
102 root->d_fsdata = &configfs_root;
103 sb->s_root = root;
104 sb->s_d_op = &configfs_dentry_ops;
105 return 0;
106}
107
108static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
109 int flags, const char *dev_name, void *data)
110{
111 return mount_single(fs_type, flags, data, configfs_fill_super);
112}
113
114static struct file_system_type configfs_fs_type = {
115 .owner = THIS_MODULE,
116 .name = "configfs",
117 .mount = configfs_do_mount,
118 .kill_sb = kill_litter_super,
119};
120
121int configfs_pin_fs(void)
122{
123 return simple_pin_fs(&configfs_fs_type, &configfs_mount,
124 &configfs_mnt_count);
125}
126
127void configfs_release_fs(void)
128{
129 simple_release_fs(&configfs_mount, &configfs_mnt_count);
130}
131
132
133static struct kobject *config_kobj;
134
135static int __init configfs_init(void)
136{
137 int err = -ENOMEM;
138
139 configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
140 sizeof(struct configfs_dirent),
141 0, 0, NULL);
142 if (!configfs_dir_cachep)
143 goto out;
144
145 config_kobj = kobject_create_and_add("config", kernel_kobj);
146 if (!config_kobj) {
147 kmem_cache_destroy(configfs_dir_cachep);
148 configfs_dir_cachep = NULL;
149 goto out;
150 }
151
152 err = register_filesystem(&configfs_fs_type);
153 if (err) {
154 printk(KERN_ERR "configfs: Unable to register filesystem!\n");
155 kobject_put(config_kobj);
156 kmem_cache_destroy(configfs_dir_cachep);
157 configfs_dir_cachep = NULL;
158 goto out;
159 }
160
161 err = configfs_inode_init();
162 if (err) {
163 unregister_filesystem(&configfs_fs_type);
164 kobject_put(config_kobj);
165 kmem_cache_destroy(configfs_dir_cachep);
166 configfs_dir_cachep = NULL;
167 }
168out:
169 return err;
170}
171
172static void __exit configfs_exit(void)
173{
174 unregister_filesystem(&configfs_fs_type);
175 kobject_put(config_kobj);
176 kmem_cache_destroy(configfs_dir_cachep);
177 configfs_dir_cachep = NULL;
178 configfs_inode_exit();
179}
180
181MODULE_AUTHOR("Oracle");
182MODULE_LICENSE("GPL");
183MODULE_VERSION("0.0.2");
184MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
185
186module_init(configfs_init);
187module_exit(configfs_exit);
188
