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16#include <linux/module.h>
17#include <linux/fs.h>
18#include <linux/mount.h>
19#include <linux/pagemap.h>
20#include <linux/init.h>
21#include <linux/namei.h>
22#include <linux/security.h>
23#include <linux/magic.h>
24
25static struct vfsmount *mount;
26static int mount_count;
27
28static int fill_super(struct super_block *sb, void *data, int silent)
29{
30 static struct tree_descr files[] = {{""}};
31
32 return simple_fill_super(sb, SECURITYFS_MAGIC, files);
33}
34
35static struct dentry *get_sb(struct file_system_type *fs_type,
36 int flags, const char *dev_name,
37 void *data)
38{
39 return mount_single(fs_type, flags, data, fill_super);
40}
41
42static struct file_system_type fs_type = {
43 .owner = THIS_MODULE,
44 .name = "securityfs",
45 .mount = get_sb,
46 .kill_sb = kill_litter_super,
47};
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77struct dentry *securityfs_create_file(const char *name, umode_t mode,
78 struct dentry *parent, void *data,
79 const struct file_operations *fops)
80{
81 struct dentry *dentry;
82 int is_dir = S_ISDIR(mode);
83 struct inode *dir, *inode;
84 int error;
85
86 if (!is_dir) {
87 BUG_ON(!fops);
88 mode = (mode & S_IALLUGO) | S_IFREG;
89 }
90
91 pr_debug("securityfs: creating file '%s'\n",name);
92
93 error = simple_pin_fs(&fs_type, &mount, &mount_count);
94 if (error)
95 return ERR_PTR(error);
96
97 if (!parent)
98 parent = mount->mnt_root;
99
100 dir = d_inode(parent);
101
102 inode_lock(dir);
103 dentry = lookup_one_len(name, parent, strlen(name));
104 if (IS_ERR(dentry))
105 goto out;
106
107 if (d_really_is_positive(dentry)) {
108 error = -EEXIST;
109 goto out1;
110 }
111
112 inode = new_inode(dir->i_sb);
113 if (!inode) {
114 error = -ENOMEM;
115 goto out1;
116 }
117
118 inode->i_ino = get_next_ino();
119 inode->i_mode = mode;
120 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
121 inode->i_private = data;
122 if (is_dir) {
123 inode->i_op = &simple_dir_inode_operations;
124 inode->i_fop = &simple_dir_operations;
125 inc_nlink(inode);
126 inc_nlink(dir);
127 } else {
128 inode->i_fop = fops;
129 }
130 d_instantiate(dentry, inode);
131 dget(dentry);
132 inode_unlock(dir);
133 return dentry;
134
135out1:
136 dput(dentry);
137 dentry = ERR_PTR(error);
138out:
139 inode_unlock(dir);
140 simple_release_fs(&mount, &mount_count);
141 return dentry;
142}
143EXPORT_SYMBOL_GPL(securityfs_create_file);
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165struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
166{
167 return securityfs_create_file(name,
168 S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
169 parent, NULL, NULL);
170}
171EXPORT_SYMBOL_GPL(securityfs_create_dir);
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185
186void securityfs_remove(struct dentry *dentry)
187{
188 struct inode *dir;
189
190 if (!dentry || IS_ERR(dentry))
191 return;
192
193 dir = d_inode(dentry->d_parent);
194 inode_lock(dir);
195 if (simple_positive(dentry)) {
196 if (d_is_dir(dentry))
197 simple_rmdir(dir, dentry);
198 else
199 simple_unlink(dir, dentry);
200 dput(dentry);
201 }
202 inode_unlock(dir);
203 simple_release_fs(&mount, &mount_count);
204}
205EXPORT_SYMBOL_GPL(securityfs_remove);
206
207static int __init securityfs_init(void)
208{
209 int retval;
210
211 retval = sysfs_create_mount_point(kernel_kobj, "security");
212 if (retval)
213 return retval;
214
215 retval = register_filesystem(&fs_type);
216 if (retval)
217 sysfs_remove_mount_point(kernel_kobj, "security");
218 return retval;
219}
220
221core_initcall(securityfs_init);
222MODULE_LICENSE("GPL");
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