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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * fs/kernfs/inode.c - kernfs inode implementation
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
8 */
9
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
20static 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
26static 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
33static 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 /* assign default attributes */
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);
56out_unlock:
57 ret = kn->iattr;
58 mutex_unlock(&iattr_mutex);
59 return ret;
60}
61
62static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
63{
64 return __kernfs_iattrs(kn, 1);
65}
66
67static struct kernfs_iattrs *kernfs_iattrs_noalloc(struct kernfs_node *kn)
68{
69 return __kernfs_iattrs(kn, 0);
70}
71
72int __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}
95
96/**
97 * kernfs_setattr - set iattr on a node
98 * @kn: target node
99 * @iattr: iattr to set
100 *
101 * Returns 0 on success, -errno on failure.
102 */
103int 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
113int 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 /* this ignores size changes */
132 setattr_copy(inode, iattr);
133
134out:
135 mutex_unlock(&kernfs_mutex);
136 return error;
137}
138
139ssize_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
151static 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
158static 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
168static 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 * kernfs_node has non-default attributes get them from
176 * persistent copy in kernfs_node.
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
184int 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
198static 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 /* initialize inode according to type */
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}
230
231/**
232 * kernfs_get_inode - get inode for kernfs_node
233 * @sb: super block
234 * @kn: kernfs_node to allocate inode for
235 *
236 * Get inode for @kn. If such inode doesn't exist, a new inode is
237 * allocated and basics are initialized. New inode is returned
238 * locked.
239 *
240 * LOCKING:
241 * Kernel thread context (may sleep).
242 *
243 * RETURNS:
244 * Pointer to allocated inode on success, NULL on failure.
245 */
246struct 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}
256
257/*
258 * The kernfs_node serves as both an inode and a directory entry for
259 * kernfs. To prevent the kernfs inode numbers from being freed
260 * prematurely we take a reference to kernfs_node from the kernfs inode. A
261 * super_operations.evict_inode() implementation is needed to drop that
262 * reference upon inode destruction.
263 */
264void 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
273int 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
289int 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
299int 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
309static 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
319static 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
330static 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
336static 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
342const struct xattr_handler *kernfs_xattr_handlers[] = {
343 &kernfs_trusted_xattr_handler,
344 &kernfs_security_xattr_handler,
345 NULL
346};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * fs/kernfs/inode.c - kernfs inode implementation
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
8 */
9
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
20static 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
26static 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
33static 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 /* assign default attributes */
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 atomic_set(&kn->iattr->nr_user_xattrs, 0);
57 atomic_set(&kn->iattr->user_xattr_size, 0);
58out_unlock:
59 ret = kn->iattr;
60 mutex_unlock(&iattr_mutex);
61 return ret;
62}
63
64static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
65{
66 return __kernfs_iattrs(kn, 1);
67}
68
69static struct kernfs_iattrs *kernfs_iattrs_noalloc(struct kernfs_node *kn)
70{
71 return __kernfs_iattrs(kn, 0);
72}
73
74int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
75{
76 struct kernfs_iattrs *attrs;
77 unsigned int ia_valid = iattr->ia_valid;
78
79 attrs = kernfs_iattrs(kn);
80 if (!attrs)
81 return -ENOMEM;
82
83 if (ia_valid & ATTR_UID)
84 attrs->ia_uid = iattr->ia_uid;
85 if (ia_valid & ATTR_GID)
86 attrs->ia_gid = iattr->ia_gid;
87 if (ia_valid & ATTR_ATIME)
88 attrs->ia_atime = iattr->ia_atime;
89 if (ia_valid & ATTR_MTIME)
90 attrs->ia_mtime = iattr->ia_mtime;
91 if (ia_valid & ATTR_CTIME)
92 attrs->ia_ctime = iattr->ia_ctime;
93 if (ia_valid & ATTR_MODE)
94 kn->mode = iattr->ia_mode;
95 return 0;
96}
97
98/**
99 * kernfs_setattr - set iattr on a node
100 * @kn: target node
101 * @iattr: iattr to set
102 *
103 * Returns 0 on success, -errno on failure.
104 */
105int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
106{
107 int ret;
108
109 mutex_lock(&kernfs_mutex);
110 ret = __kernfs_setattr(kn, iattr);
111 mutex_unlock(&kernfs_mutex);
112 return ret;
113}
114
115int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr)
116{
117 struct inode *inode = d_inode(dentry);
118 struct kernfs_node *kn = inode->i_private;
119 int error;
120
121 if (!kn)
122 return -EINVAL;
123
124 mutex_lock(&kernfs_mutex);
125 error = setattr_prepare(dentry, iattr);
126 if (error)
127 goto out;
128
129 error = __kernfs_setattr(kn, iattr);
130 if (error)
131 goto out;
132
133 /* this ignores size changes */
134 setattr_copy(inode, iattr);
135
136out:
137 mutex_unlock(&kernfs_mutex);
138 return error;
139}
140
141ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
142{
143 struct kernfs_node *kn = kernfs_dentry_node(dentry);
144 struct kernfs_iattrs *attrs;
145
146 attrs = kernfs_iattrs(kn);
147 if (!attrs)
148 return -ENOMEM;
149
150 return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size);
151}
152
153static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
154{
155 inode->i_mode = mode;
156 inode->i_atime = inode->i_mtime =
157 inode->i_ctime = current_time(inode);
158}
159
160static inline void set_inode_attr(struct inode *inode,
161 struct kernfs_iattrs *attrs)
162{
163 inode->i_uid = attrs->ia_uid;
164 inode->i_gid = attrs->ia_gid;
165 inode->i_atime = attrs->ia_atime;
166 inode->i_mtime = attrs->ia_mtime;
167 inode->i_ctime = attrs->ia_ctime;
168}
169
170static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
171{
172 struct kernfs_iattrs *attrs = kn->iattr;
173
174 inode->i_mode = kn->mode;
175 if (attrs)
176 /*
177 * kernfs_node has non-default attributes get them from
178 * persistent copy in kernfs_node.
179 */
180 set_inode_attr(inode, attrs);
181
182 if (kernfs_type(kn) == KERNFS_DIR)
183 set_nlink(inode, kn->dir.subdirs + 2);
184}
185
186int kernfs_iop_getattr(const struct path *path, struct kstat *stat,
187 u32 request_mask, unsigned int query_flags)
188{
189 struct inode *inode = d_inode(path->dentry);
190 struct kernfs_node *kn = inode->i_private;
191
192 mutex_lock(&kernfs_mutex);
193 kernfs_refresh_inode(kn, inode);
194 mutex_unlock(&kernfs_mutex);
195
196 generic_fillattr(inode, stat);
197 return 0;
198}
199
200static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
201{
202 kernfs_get(kn);
203 inode->i_private = kn;
204 inode->i_mapping->a_ops = &kernfs_aops;
205 inode->i_op = &kernfs_iops;
206 inode->i_generation = kernfs_gen(kn);
207
208 set_default_inode_attr(inode, kn->mode);
209 kernfs_refresh_inode(kn, inode);
210
211 /* initialize inode according to type */
212 switch (kernfs_type(kn)) {
213 case KERNFS_DIR:
214 inode->i_op = &kernfs_dir_iops;
215 inode->i_fop = &kernfs_dir_fops;
216 if (kn->flags & KERNFS_EMPTY_DIR)
217 make_empty_dir_inode(inode);
218 break;
219 case KERNFS_FILE:
220 inode->i_size = kn->attr.size;
221 inode->i_fop = &kernfs_file_fops;
222 break;
223 case KERNFS_LINK:
224 inode->i_op = &kernfs_symlink_iops;
225 break;
226 default:
227 BUG();
228 }
229
230 unlock_new_inode(inode);
231}
232
233/**
234 * kernfs_get_inode - get inode for kernfs_node
235 * @sb: super block
236 * @kn: kernfs_node to allocate inode for
237 *
238 * Get inode for @kn. If such inode doesn't exist, a new inode is
239 * allocated and basics are initialized. New inode is returned
240 * locked.
241 *
242 * LOCKING:
243 * Kernel thread context (may sleep).
244 *
245 * RETURNS:
246 * Pointer to allocated inode on success, NULL on failure.
247 */
248struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn)
249{
250 struct inode *inode;
251
252 inode = iget_locked(sb, kernfs_ino(kn));
253 if (inode && (inode->i_state & I_NEW))
254 kernfs_init_inode(kn, inode);
255
256 return inode;
257}
258
259/*
260 * The kernfs_node serves as both an inode and a directory entry for
261 * kernfs. To prevent the kernfs inode numbers from being freed
262 * prematurely we take a reference to kernfs_node from the kernfs inode. A
263 * super_operations.evict_inode() implementation is needed to drop that
264 * reference upon inode destruction.
265 */
266void kernfs_evict_inode(struct inode *inode)
267{
268 struct kernfs_node *kn = inode->i_private;
269
270 truncate_inode_pages_final(&inode->i_data);
271 clear_inode(inode);
272 kernfs_put(kn);
273}
274
275int kernfs_iop_permission(struct inode *inode, int mask)
276{
277 struct kernfs_node *kn;
278
279 if (mask & MAY_NOT_BLOCK)
280 return -ECHILD;
281
282 kn = inode->i_private;
283
284 mutex_lock(&kernfs_mutex);
285 kernfs_refresh_inode(kn, inode);
286 mutex_unlock(&kernfs_mutex);
287
288 return generic_permission(inode, mask);
289}
290
291int kernfs_xattr_get(struct kernfs_node *kn, const char *name,
292 void *value, size_t size)
293{
294 struct kernfs_iattrs *attrs = kernfs_iattrs_noalloc(kn);
295 if (!attrs)
296 return -ENODATA;
297
298 return simple_xattr_get(&attrs->xattrs, name, value, size);
299}
300
301int kernfs_xattr_set(struct kernfs_node *kn, const char *name,
302 const void *value, size_t size, int flags)
303{
304 struct kernfs_iattrs *attrs = kernfs_iattrs(kn);
305 if (!attrs)
306 return -ENOMEM;
307
308 return simple_xattr_set(&attrs->xattrs, name, value, size, flags, NULL);
309}
310
311static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
312 struct dentry *unused, struct inode *inode,
313 const char *suffix, void *value, size_t size)
314{
315 const char *name = xattr_full_name(handler, suffix);
316 struct kernfs_node *kn = inode->i_private;
317
318 return kernfs_xattr_get(kn, name, value, size);
319}
320
321static int kernfs_vfs_xattr_set(const struct xattr_handler *handler,
322 struct dentry *unused, struct inode *inode,
323 const char *suffix, const void *value,
324 size_t size, int flags)
325{
326 const char *name = xattr_full_name(handler, suffix);
327 struct kernfs_node *kn = inode->i_private;
328
329 return kernfs_xattr_set(kn, name, value, size, flags);
330}
331
332static int kernfs_vfs_user_xattr_add(struct kernfs_node *kn,
333 const char *full_name,
334 struct simple_xattrs *xattrs,
335 const void *value, size_t size, int flags)
336{
337 atomic_t *sz = &kn->iattr->user_xattr_size;
338 atomic_t *nr = &kn->iattr->nr_user_xattrs;
339 ssize_t removed_size;
340 int ret;
341
342 if (atomic_inc_return(nr) > KERNFS_MAX_USER_XATTRS) {
343 ret = -ENOSPC;
344 goto dec_count_out;
345 }
346
347 if (atomic_add_return(size, sz) > KERNFS_USER_XATTR_SIZE_LIMIT) {
348 ret = -ENOSPC;
349 goto dec_size_out;
350 }
351
352 ret = simple_xattr_set(xattrs, full_name, value, size, flags,
353 &removed_size);
354
355 if (!ret && removed_size >= 0)
356 size = removed_size;
357 else if (!ret)
358 return 0;
359dec_size_out:
360 atomic_sub(size, sz);
361dec_count_out:
362 atomic_dec(nr);
363 return ret;
364}
365
366static int kernfs_vfs_user_xattr_rm(struct kernfs_node *kn,
367 const char *full_name,
368 struct simple_xattrs *xattrs,
369 const void *value, size_t size, int flags)
370{
371 atomic_t *sz = &kn->iattr->user_xattr_size;
372 atomic_t *nr = &kn->iattr->nr_user_xattrs;
373 ssize_t removed_size;
374 int ret;
375
376 ret = simple_xattr_set(xattrs, full_name, value, size, flags,
377 &removed_size);
378
379 if (removed_size >= 0) {
380 atomic_sub(removed_size, sz);
381 atomic_dec(nr);
382 }
383
384 return ret;
385}
386
387static int kernfs_vfs_user_xattr_set(const struct xattr_handler *handler,
388 struct dentry *unused, struct inode *inode,
389 const char *suffix, const void *value,
390 size_t size, int flags)
391{
392 const char *full_name = xattr_full_name(handler, suffix);
393 struct kernfs_node *kn = inode->i_private;
394 struct kernfs_iattrs *attrs;
395
396 if (!(kernfs_root(kn)->flags & KERNFS_ROOT_SUPPORT_USER_XATTR))
397 return -EOPNOTSUPP;
398
399 attrs = kernfs_iattrs(kn);
400 if (!attrs)
401 return -ENOMEM;
402
403 if (value)
404 return kernfs_vfs_user_xattr_add(kn, full_name, &attrs->xattrs,
405 value, size, flags);
406 else
407 return kernfs_vfs_user_xattr_rm(kn, full_name, &attrs->xattrs,
408 value, size, flags);
409
410}
411
412static const struct xattr_handler kernfs_trusted_xattr_handler = {
413 .prefix = XATTR_TRUSTED_PREFIX,
414 .get = kernfs_vfs_xattr_get,
415 .set = kernfs_vfs_xattr_set,
416};
417
418static const struct xattr_handler kernfs_security_xattr_handler = {
419 .prefix = XATTR_SECURITY_PREFIX,
420 .get = kernfs_vfs_xattr_get,
421 .set = kernfs_vfs_xattr_set,
422};
423
424static const struct xattr_handler kernfs_user_xattr_handler = {
425 .prefix = XATTR_USER_PREFIX,
426 .get = kernfs_vfs_xattr_get,
427 .set = kernfs_vfs_user_xattr_set,
428};
429
430const struct xattr_handler *kernfs_xattr_handlers[] = {
431 &kernfs_trusted_xattr_handler,
432 &kernfs_security_xattr_handler,
433 &kernfs_user_xattr_handler,
434 NULL
435};