Root/
1 | /* |
2 | * inode.c - securityfs |
3 | * |
4 | * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de> |
5 | * |
6 | * This program is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU General Public License version |
8 | * 2 as published by the Free Software Foundation. |
9 | * |
10 | * Based on fs/debugfs/inode.c which had the following copyright notice: |
11 | * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> |
12 | * Copyright (C) 2004 IBM Inc. |
13 | */ |
14 | |
15 | /* #define DEBUG */ |
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 | |
25 | static struct vfsmount *mount; |
26 | static int mount_count; |
27 | |
28 | static inline int positive(struct dentry *dentry) |
29 | { |
30 | return dentry->d_inode && !d_unhashed(dentry); |
31 | } |
32 | |
33 | static int fill_super(struct super_block *sb, void *data, int silent) |
34 | { |
35 | static struct tree_descr files[] = {{""}}; |
36 | |
37 | return simple_fill_super(sb, SECURITYFS_MAGIC, files); |
38 | } |
39 | |
40 | static struct dentry *get_sb(struct file_system_type *fs_type, |
41 | int flags, const char *dev_name, |
42 | void *data) |
43 | { |
44 | return mount_single(fs_type, flags, data, fill_super); |
45 | } |
46 | |
47 | static struct file_system_type fs_type = { |
48 | .owner = THIS_MODULE, |
49 | .name = "securityfs", |
50 | .mount = get_sb, |
51 | .kill_sb = kill_litter_super, |
52 | }; |
53 | |
54 | /** |
55 | * securityfs_create_file - create a file in the securityfs filesystem |
56 | * |
57 | * @name: a pointer to a string containing the name of the file to create. |
58 | * @mode: the permission that the file should have |
59 | * @parent: a pointer to the parent dentry for this file. This should be a |
60 | * directory dentry if set. If this parameter is %NULL, then the |
61 | * file will be created in the root of the securityfs filesystem. |
62 | * @data: a pointer to something that the caller will want to get to later |
63 | * on. The inode.i_private pointer will point to this value on |
64 | * the open() call. |
65 | * @fops: a pointer to a struct file_operations that should be used for |
66 | * this file. |
67 | * |
68 | * This is the basic "create a file" function for securityfs. It allows for a |
69 | * wide range of flexibility in creating a file, or a directory (if you |
70 | * want to create a directory, the securityfs_create_dir() function is |
71 | * recommended to be used instead). |
72 | * |
73 | * This function returns a pointer to a dentry if it succeeds. This |
74 | * pointer must be passed to the securityfs_remove() function when the file is |
75 | * to be removed (no automatic cleanup happens if your module is unloaded, |
76 | * you are responsible here). If an error occurs, the function will return |
77 | * the erorr value (via ERR_PTR). |
78 | * |
79 | * If securityfs is not enabled in the kernel, the value %-ENODEV is |
80 | * returned. |
81 | */ |
82 | struct dentry *securityfs_create_file(const char *name, umode_t mode, |
83 | struct dentry *parent, void *data, |
84 | const struct file_operations *fops) |
85 | { |
86 | struct dentry *dentry; |
87 | int is_dir = S_ISDIR(mode); |
88 | struct inode *dir, *inode; |
89 | int error; |
90 | |
91 | if (!is_dir) { |
92 | BUG_ON(!fops); |
93 | mode = (mode & S_IALLUGO) | S_IFREG; |
94 | } |
95 | |
96 | pr_debug("securityfs: creating file '%s'\n",name); |
97 | |
98 | error = simple_pin_fs(&fs_type, &mount, &mount_count); |
99 | if (error) |
100 | return ERR_PTR(error); |
101 | |
102 | if (!parent) |
103 | parent = mount->mnt_root; |
104 | |
105 | dir = parent->d_inode; |
106 | |
107 | mutex_lock(&dir->i_mutex); |
108 | dentry = lookup_one_len(name, parent, strlen(name)); |
109 | if (IS_ERR(dentry)) |
110 | goto out; |
111 | |
112 | if (dentry->d_inode) { |
113 | error = -EEXIST; |
114 | goto out1; |
115 | } |
116 | |
117 | inode = new_inode(dir->i_sb); |
118 | if (!inode) { |
119 | error = -ENOMEM; |
120 | goto out1; |
121 | } |
122 | |
123 | inode->i_ino = get_next_ino(); |
124 | inode->i_mode = mode; |
125 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
126 | inode->i_private = data; |
127 | if (is_dir) { |
128 | inode->i_op = &simple_dir_inode_operations; |
129 | inode->i_fop = &simple_dir_operations; |
130 | inc_nlink(inode); |
131 | inc_nlink(dir); |
132 | } else { |
133 | inode->i_fop = fops; |
134 | } |
135 | d_instantiate(dentry, inode); |
136 | dget(dentry); |
137 | mutex_unlock(&dir->i_mutex); |
138 | return dentry; |
139 | |
140 | out1: |
141 | dput(dentry); |
142 | dentry = ERR_PTR(error); |
143 | out: |
144 | mutex_unlock(&dir->i_mutex); |
145 | simple_release_fs(&mount, &mount_count); |
146 | return dentry; |
147 | } |
148 | EXPORT_SYMBOL_GPL(securityfs_create_file); |
149 | |
150 | /** |
151 | * securityfs_create_dir - create a directory in the securityfs filesystem |
152 | * |
153 | * @name: a pointer to a string containing the name of the directory to |
154 | * create. |
155 | * @parent: a pointer to the parent dentry for this file. This should be a |
156 | * directory dentry if set. If this parameter is %NULL, then the |
157 | * directory will be created in the root of the securityfs filesystem. |
158 | * |
159 | * This function creates a directory in securityfs with the given @name. |
160 | * |
161 | * This function returns a pointer to a dentry if it succeeds. This |
162 | * pointer must be passed to the securityfs_remove() function when the file is |
163 | * to be removed (no automatic cleanup happens if your module is unloaded, |
164 | * you are responsible here). If an error occurs, %NULL will be returned. |
165 | * |
166 | * If securityfs is not enabled in the kernel, the value %-ENODEV is |
167 | * returned. It is not wise to check for this value, but rather, check for |
168 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
169 | * code. |
170 | */ |
171 | struct dentry *securityfs_create_dir(const char *name, struct dentry *parent) |
172 | { |
173 | return securityfs_create_file(name, |
174 | S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
175 | parent, NULL, NULL); |
176 | } |
177 | EXPORT_SYMBOL_GPL(securityfs_create_dir); |
178 | |
179 | /** |
180 | * securityfs_remove - removes a file or directory from the securityfs filesystem |
181 | * |
182 | * @dentry: a pointer to a the dentry of the file or directory to be removed. |
183 | * |
184 | * This function removes a file or directory in securityfs that was previously |
185 | * created with a call to another securityfs function (like |
186 | * securityfs_create_file() or variants thereof.) |
187 | * |
188 | * This function is required to be called in order for the file to be |
189 | * removed. No automatic cleanup of files will happen when a module is |
190 | * removed; you are responsible here. |
191 | */ |
192 | void securityfs_remove(struct dentry *dentry) |
193 | { |
194 | struct dentry *parent; |
195 | |
196 | if (!dentry || IS_ERR(dentry)) |
197 | return; |
198 | |
199 | parent = dentry->d_parent; |
200 | if (!parent || !parent->d_inode) |
201 | return; |
202 | |
203 | mutex_lock(&parent->d_inode->i_mutex); |
204 | if (positive(dentry)) { |
205 | if (dentry->d_inode) { |
206 | if (S_ISDIR(dentry->d_inode->i_mode)) |
207 | simple_rmdir(parent->d_inode, dentry); |
208 | else |
209 | simple_unlink(parent->d_inode, dentry); |
210 | dput(dentry); |
211 | } |
212 | } |
213 | mutex_unlock(&parent->d_inode->i_mutex); |
214 | simple_release_fs(&mount, &mount_count); |
215 | } |
216 | EXPORT_SYMBOL_GPL(securityfs_remove); |
217 | |
218 | static struct kobject *security_kobj; |
219 | |
220 | static int __init securityfs_init(void) |
221 | { |
222 | int retval; |
223 | |
224 | security_kobj = kobject_create_and_add("security", kernel_kobj); |
225 | if (!security_kobj) |
226 | return -EINVAL; |
227 | |
228 | retval = register_filesystem(&fs_type); |
229 | if (retval) |
230 | kobject_put(security_kobj); |
231 | return retval; |
232 | } |
233 | |
234 | core_initcall(securityfs_init); |
235 | MODULE_LICENSE("GPL"); |
236 | |
237 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9