This source file includes following definitions.
- __kernfs_iattrs
- kernfs_iattrs_noalloc
- __kernfs_setattr
- kernfs_setattr
- kernfs_iop_setattr
- kernfs_iop_listxattr
- set_default_inode_attr
- set_inode_attr
- kernfs_refresh_inode
- kernfs_iop_getattr
- kernfs_init_inode
- kernfs_get_inode
- kernfs_evict_inode
- kernfs_iop_permission
- kernfs_xattr_get
- kernfs_xattr_set
- kernfs_vfs_xattr_get
- kernfs_vfs_xattr_set
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10 #include <linux/pagemap.h>
11 #include <linux/backing-dev.h>
12 #include <linux/capability.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/xattr.h>
16 #include <linux/security.h>
17
18 #include "kernfs-internal.h"
19
20 static const struct address_space_operations kernfs_aops = {
21 .readpage = simple_readpage,
22 .write_begin = simple_write_begin,
23 .write_end = simple_write_end,
24 };
25
26 static const struct inode_operations kernfs_iops = {
27 .permission = kernfs_iop_permission,
28 .setattr = kernfs_iop_setattr,
29 .getattr = kernfs_iop_getattr,
30 .listxattr = kernfs_iop_listxattr,
31 };
32
33 static struct kernfs_iattrs *__kernfs_iattrs(struct kernfs_node *kn, int alloc)
34 {
35 static DEFINE_MUTEX(iattr_mutex);
36 struct kernfs_iattrs *ret;
37
38 mutex_lock(&iattr_mutex);
39
40 if (kn->iattr || !alloc)
41 goto out_unlock;
42
43 kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);
44 if (!kn->iattr)
45 goto out_unlock;
46
47
48 kn->iattr->ia_uid = GLOBAL_ROOT_UID;
49 kn->iattr->ia_gid = GLOBAL_ROOT_GID;
50
51 ktime_get_real_ts64(&kn->iattr->ia_atime);
52 kn->iattr->ia_mtime = kn->iattr->ia_atime;
53 kn->iattr->ia_ctime = kn->iattr->ia_atime;
54
55 simple_xattrs_init(&kn->iattr->xattrs);
56 out_unlock:
57 ret = kn->iattr;
58 mutex_unlock(&iattr_mutex);
59 return ret;
60 }
61
62 static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
63 {
64 return __kernfs_iattrs(kn, 1);
65 }
66
67 static struct kernfs_iattrs *kernfs_iattrs_noalloc(struct kernfs_node *kn)
68 {
69 return __kernfs_iattrs(kn, 0);
70 }
71
72 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
73 {
74 struct kernfs_iattrs *attrs;
75 unsigned int ia_valid = iattr->ia_valid;
76
77 attrs = kernfs_iattrs(kn);
78 if (!attrs)
79 return -ENOMEM;
80
81 if (ia_valid & ATTR_UID)
82 attrs->ia_uid = iattr->ia_uid;
83 if (ia_valid & ATTR_GID)
84 attrs->ia_gid = iattr->ia_gid;
85 if (ia_valid & ATTR_ATIME)
86 attrs->ia_atime = iattr->ia_atime;
87 if (ia_valid & ATTR_MTIME)
88 attrs->ia_mtime = iattr->ia_mtime;
89 if (ia_valid & ATTR_CTIME)
90 attrs->ia_ctime = iattr->ia_ctime;
91 if (ia_valid & ATTR_MODE)
92 kn->mode = iattr->ia_mode;
93 return 0;
94 }
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102
103 int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
104 {
105 int ret;
106
107 mutex_lock(&kernfs_mutex);
108 ret = __kernfs_setattr(kn, iattr);
109 mutex_unlock(&kernfs_mutex);
110 return ret;
111 }
112
113 int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr)
114 {
115 struct inode *inode = d_inode(dentry);
116 struct kernfs_node *kn = inode->i_private;
117 int error;
118
119 if (!kn)
120 return -EINVAL;
121
122 mutex_lock(&kernfs_mutex);
123 error = setattr_prepare(dentry, iattr);
124 if (error)
125 goto out;
126
127 error = __kernfs_setattr(kn, iattr);
128 if (error)
129 goto out;
130
131
132 setattr_copy(inode, iattr);
133
134 out:
135 mutex_unlock(&kernfs_mutex);
136 return error;
137 }
138
139 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
140 {
141 struct kernfs_node *kn = kernfs_dentry_node(dentry);
142 struct kernfs_iattrs *attrs;
143
144 attrs = kernfs_iattrs(kn);
145 if (!attrs)
146 return -ENOMEM;
147
148 return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size);
149 }
150
151 static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
152 {
153 inode->i_mode = mode;
154 inode->i_atime = inode->i_mtime =
155 inode->i_ctime = current_time(inode);
156 }
157
158 static inline void set_inode_attr(struct inode *inode,
159 struct kernfs_iattrs *attrs)
160 {
161 inode->i_uid = attrs->ia_uid;
162 inode->i_gid = attrs->ia_gid;
163 inode->i_atime = timestamp_truncate(attrs->ia_atime, inode);
164 inode->i_mtime = timestamp_truncate(attrs->ia_mtime, inode);
165 inode->i_ctime = timestamp_truncate(attrs->ia_ctime, inode);
166 }
167
168 static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
169 {
170 struct kernfs_iattrs *attrs = kn->iattr;
171
172 inode->i_mode = kn->mode;
173 if (attrs)
174
175
176
177
178 set_inode_attr(inode, attrs);
179
180 if (kernfs_type(kn) == KERNFS_DIR)
181 set_nlink(inode, kn->dir.subdirs + 2);
182 }
183
184 int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
185 u32 request_mask, unsigned int query_flags)
186 {
187 struct inode *inode = d_inode(path->dentry);
188 struct kernfs_node *kn = inode->i_private;
189
190 mutex_lock(&kernfs_mutex);
191 kernfs_refresh_inode(kn, inode);
192 mutex_unlock(&kernfs_mutex);
193
194 generic_fillattr(inode, stat);
195 return 0;
196 }
197
198 static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
199 {
200 kernfs_get(kn);
201 inode->i_private = kn;
202 inode->i_mapping->a_ops = &kernfs_aops;
203 inode->i_op = &kernfs_iops;
204 inode->i_generation = kn->id.generation;
205
206 set_default_inode_attr(inode, kn->mode);
207 kernfs_refresh_inode(kn, inode);
208
209
210 switch (kernfs_type(kn)) {
211 case KERNFS_DIR:
212 inode->i_op = &kernfs_dir_iops;
213 inode->i_fop = &kernfs_dir_fops;
214 if (kn->flags & KERNFS_EMPTY_DIR)
215 make_empty_dir_inode(inode);
216 break;
217 case KERNFS_FILE:
218 inode->i_size = kn->attr.size;
219 inode->i_fop = &kernfs_file_fops;
220 break;
221 case KERNFS_LINK:
222 inode->i_op = &kernfs_symlink_iops;
223 break;
224 default:
225 BUG();
226 }
227
228 unlock_new_inode(inode);
229 }
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245
246 struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn)
247 {
248 struct inode *inode;
249
250 inode = iget_locked(sb, kn->id.ino);
251 if (inode && (inode->i_state & I_NEW))
252 kernfs_init_inode(kn, inode);
253
254 return inode;
255 }
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263
264 void kernfs_evict_inode(struct inode *inode)
265 {
266 struct kernfs_node *kn = inode->i_private;
267
268 truncate_inode_pages_final(&inode->i_data);
269 clear_inode(inode);
270 kernfs_put(kn);
271 }
272
273 int kernfs_iop_permission(struct inode *inode, int mask)
274 {
275 struct kernfs_node *kn;
276
277 if (mask & MAY_NOT_BLOCK)
278 return -ECHILD;
279
280 kn = inode->i_private;
281
282 mutex_lock(&kernfs_mutex);
283 kernfs_refresh_inode(kn, inode);
284 mutex_unlock(&kernfs_mutex);
285
286 return generic_permission(inode, mask);
287 }
288
289 int kernfs_xattr_get(struct kernfs_node *kn, const char *name,
290 void *value, size_t size)
291 {
292 struct kernfs_iattrs *attrs = kernfs_iattrs_noalloc(kn);
293 if (!attrs)
294 return -ENODATA;
295
296 return simple_xattr_get(&attrs->xattrs, name, value, size);
297 }
298
299 int kernfs_xattr_set(struct kernfs_node *kn, const char *name,
300 const void *value, size_t size, int flags)
301 {
302 struct kernfs_iattrs *attrs = kernfs_iattrs(kn);
303 if (!attrs)
304 return -ENOMEM;
305
306 return simple_xattr_set(&attrs->xattrs, name, value, size, flags);
307 }
308
309 static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
310 struct dentry *unused, struct inode *inode,
311 const char *suffix, void *value, size_t size)
312 {
313 const char *name = xattr_full_name(handler, suffix);
314 struct kernfs_node *kn = inode->i_private;
315
316 return kernfs_xattr_get(kn, name, value, size);
317 }
318
319 static int kernfs_vfs_xattr_set(const struct xattr_handler *handler,
320 struct dentry *unused, struct inode *inode,
321 const char *suffix, const void *value,
322 size_t size, int flags)
323 {
324 const char *name = xattr_full_name(handler, suffix);
325 struct kernfs_node *kn = inode->i_private;
326
327 return kernfs_xattr_set(kn, name, value, size, flags);
328 }
329
330 static const struct xattr_handler kernfs_trusted_xattr_handler = {
331 .prefix = XATTR_TRUSTED_PREFIX,
332 .get = kernfs_vfs_xattr_get,
333 .set = kernfs_vfs_xattr_set,
334 };
335
336 static const struct xattr_handler kernfs_security_xattr_handler = {
337 .prefix = XATTR_SECURITY_PREFIX,
338 .get = kernfs_vfs_xattr_get,
339 .set = kernfs_vfs_xattr_set,
340 };
341
342 const struct xattr_handler *kernfs_xattr_handlers[] = {
343 &kernfs_trusted_xattr_handler,
344 &kernfs_security_xattr_handler,
345 NULL
346 };