Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * file.c - operations for regular (text) files. | |
3 | */ | |
4 | ||
5 | #include <linux/module.h> | |
0eeca283 | 6 | #include <linux/fsnotify.h> |
1da177e4 | 7 | #include <linux/kobject.h> |
5f45f1a7 | 8 | #include <linux/namei.h> |
4508a7a7 | 9 | #include <linux/poll.h> |
94bebf4d | 10 | #include <linux/list.h> |
1da177e4 LT |
11 | #include <asm/uaccess.h> |
12 | #include <asm/semaphore.h> | |
13 | ||
14 | #include "sysfs.h" | |
15 | ||
16 | #define to_subsys(k) container_of(k,struct subsystem,kset.kobj) | |
17 | #define to_sattr(a) container_of(a,struct subsys_attribute,attr) | |
18 | ||
3d41088f | 19 | /* |
1da177e4 LT |
20 | * Subsystem file operations. |
21 | * These operations allow subsystems to have files that can be | |
22 | * read/written. | |
23 | */ | |
24 | static ssize_t | |
25 | subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page) | |
26 | { | |
27 | struct subsystem * s = to_subsys(kobj); | |
28 | struct subsys_attribute * sattr = to_sattr(attr); | |
c76d0abd | 29 | ssize_t ret = -EIO; |
1da177e4 LT |
30 | |
31 | if (sattr->show) | |
32 | ret = sattr->show(s,page); | |
33 | return ret; | |
34 | } | |
35 | ||
36 | static ssize_t | |
37 | subsys_attr_store(struct kobject * kobj, struct attribute * attr, | |
38 | const char * page, size_t count) | |
39 | { | |
40 | struct subsystem * s = to_subsys(kobj); | |
41 | struct subsys_attribute * sattr = to_sattr(attr); | |
c76d0abd | 42 | ssize_t ret = -EIO; |
1da177e4 LT |
43 | |
44 | if (sattr->store) | |
45 | ret = sattr->store(s,page,count); | |
46 | return ret; | |
47 | } | |
48 | ||
49 | static struct sysfs_ops subsys_sysfs_ops = { | |
50 | .show = subsys_attr_show, | |
51 | .store = subsys_attr_store, | |
52 | }; | |
53 | ||
94bebf4d ON |
54 | /** |
55 | * add_to_collection - add buffer to a collection | |
56 | * @buffer: buffer to be added | |
f95d882d | 57 | * @node: inode of set to add to |
94bebf4d | 58 | */ |
1da177e4 | 59 | |
94bebf4d ON |
60 | static inline void |
61 | add_to_collection(struct sysfs_buffer *buffer, struct inode *node) | |
62 | { | |
63 | struct sysfs_buffer_collection *set = node->i_private; | |
1da177e4 | 64 | |
94bebf4d ON |
65 | mutex_lock(&node->i_mutex); |
66 | list_add(&buffer->associates, &set->associates); | |
67 | mutex_unlock(&node->i_mutex); | |
68 | } | |
69 | ||
70 | static inline void | |
71 | remove_from_collection(struct sysfs_buffer *buffer, struct inode *node) | |
72 | { | |
73 | mutex_lock(&node->i_mutex); | |
74 | list_del(&buffer->associates); | |
75 | mutex_unlock(&node->i_mutex); | |
76 | } | |
1da177e4 LT |
77 | |
78 | /** | |
79 | * fill_read_buffer - allocate and fill buffer from object. | |
80 | * @dentry: dentry pointer. | |
81 | * @buffer: data buffer for file. | |
82 | * | |
83 | * Allocate @buffer->page, if it hasn't been already, then call the | |
84 | * kobject's show() method to fill the buffer with this attribute's | |
85 | * data. | |
82244b16 ON |
86 | * This is called only once, on the file's first read unless an error |
87 | * is returned. | |
1da177e4 LT |
88 | */ |
89 | static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer) | |
90 | { | |
4508a7a7 | 91 | struct sysfs_dirent * sd = dentry->d_fsdata; |
1da177e4 LT |
92 | struct attribute * attr = to_attr(dentry); |
93 | struct kobject * kobj = to_kobj(dentry->d_parent); | |
94 | struct sysfs_ops * ops = buffer->ops; | |
95 | int ret = 0; | |
96 | ssize_t count; | |
97 | ||
98 | if (!buffer->page) | |
99 | buffer->page = (char *) get_zeroed_page(GFP_KERNEL); | |
100 | if (!buffer->page) | |
101 | return -ENOMEM; | |
102 | ||
4508a7a7 | 103 | buffer->event = atomic_read(&sd->s_event); |
1da177e4 | 104 | count = ops->show(kobj,attr,buffer->page); |
1da177e4 | 105 | BUG_ON(count > (ssize_t)PAGE_SIZE); |
82244b16 ON |
106 | if (count >= 0) { |
107 | buffer->needs_read_fill = 0; | |
1da177e4 | 108 | buffer->count = count; |
82244b16 | 109 | } else { |
1da177e4 | 110 | ret = count; |
82244b16 | 111 | } |
1da177e4 LT |
112 | return ret; |
113 | } | |
114 | ||
115 | ||
116 | /** | |
117 | * flush_read_buffer - push buffer to userspace. | |
118 | * @buffer: data buffer for file. | |
67be2dd1 | 119 | * @buf: user-passed buffer. |
1da177e4 LT |
120 | * @count: number of bytes requested. |
121 | * @ppos: file position. | |
122 | * | |
123 | * Copy the buffer we filled in fill_read_buffer() to userspace. | |
124 | * This is done at the reader's leisure, copying and advancing | |
125 | * the amount they specify each time. | |
126 | * This may be called continuously until the buffer is empty. | |
127 | */ | |
128 | static int flush_read_buffer(struct sysfs_buffer * buffer, char __user * buf, | |
129 | size_t count, loff_t * ppos) | |
130 | { | |
131 | int error; | |
132 | ||
133 | if (*ppos > buffer->count) | |
134 | return 0; | |
135 | ||
136 | if (count > (buffer->count - *ppos)) | |
137 | count = buffer->count - *ppos; | |
138 | ||
139 | error = copy_to_user(buf,buffer->page + *ppos,count); | |
140 | if (!error) | |
141 | *ppos += count; | |
142 | return error ? -EFAULT : count; | |
143 | } | |
144 | ||
145 | /** | |
146 | * sysfs_read_file - read an attribute. | |
147 | * @file: file pointer. | |
148 | * @buf: buffer to fill. | |
149 | * @count: number of bytes to read. | |
150 | * @ppos: starting offset in file. | |
151 | * | |
152 | * Userspace wants to read an attribute file. The attribute descriptor | |
153 | * is in the file's ->d_fsdata. The target object is in the directory's | |
154 | * ->d_fsdata. | |
155 | * | |
156 | * We call fill_read_buffer() to allocate and fill the buffer from the | |
157 | * object's show() method exactly once (if the read is happening from | |
158 | * the beginning of the file). That should fill the entire buffer with | |
159 | * all the data the object has to offer for that attribute. | |
160 | * We then call flush_read_buffer() to copy the buffer to userspace | |
161 | * in the increments specified. | |
162 | */ | |
163 | ||
164 | static ssize_t | |
165 | sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
166 | { | |
167 | struct sysfs_buffer * buffer = file->private_data; | |
168 | ssize_t retval = 0; | |
169 | ||
170 | down(&buffer->sem); | |
94bebf4d ON |
171 | if (buffer->orphaned) { |
172 | retval = -ENODEV; | |
173 | goto out; | |
174 | } | |
1da177e4 | 175 | if (buffer->needs_read_fill) { |
f427f5d5 | 176 | if ((retval = fill_read_buffer(file->f_path.dentry,buffer))) |
1da177e4 LT |
177 | goto out; |
178 | } | |
5c1fdf41 ZB |
179 | pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", |
180 | __FUNCTION__, count, *ppos, buffer->page); | |
1da177e4 LT |
181 | retval = flush_read_buffer(buffer,buf,count,ppos); |
182 | out: | |
183 | up(&buffer->sem); | |
184 | return retval; | |
185 | } | |
186 | ||
1da177e4 LT |
187 | /** |
188 | * fill_write_buffer - copy buffer from userspace. | |
189 | * @buffer: data buffer for file. | |
67be2dd1 | 190 | * @buf: data from user. |
1da177e4 LT |
191 | * @count: number of bytes in @userbuf. |
192 | * | |
193 | * Allocate @buffer->page if it hasn't been already, then | |
194 | * copy the user-supplied buffer into it. | |
195 | */ | |
196 | ||
197 | static int | |
198 | fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t count) | |
199 | { | |
200 | int error; | |
201 | ||
202 | if (!buffer->page) | |
203 | buffer->page = (char *)get_zeroed_page(GFP_KERNEL); | |
204 | if (!buffer->page) | |
205 | return -ENOMEM; | |
206 | ||
207 | if (count >= PAGE_SIZE) | |
6e0dd741 | 208 | count = PAGE_SIZE - 1; |
1da177e4 LT |
209 | error = copy_from_user(buffer->page,buf,count); |
210 | buffer->needs_read_fill = 1; | |
035ed7a4 TM |
211 | /* if buf is assumed to contain a string, terminate it by \0, |
212 | so e.g. sscanf() can scan the string easily */ | |
213 | buffer->page[count] = 0; | |
1da177e4 LT |
214 | return error ? -EFAULT : count; |
215 | } | |
216 | ||
217 | ||
218 | /** | |
219 | * flush_write_buffer - push buffer to kobject. | |
3d41088f | 220 | * @dentry: dentry to the attribute |
1da177e4 | 221 | * @buffer: data buffer for file. |
3d41088f | 222 | * @count: number of bytes |
1da177e4 LT |
223 | * |
224 | * Get the correct pointers for the kobject and the attribute we're | |
225 | * dealing with, then call the store() method for the attribute, | |
226 | * passing the buffer that we acquired in fill_write_buffer(). | |
227 | */ | |
228 | ||
229 | static int | |
230 | flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count) | |
231 | { | |
232 | struct attribute * attr = to_attr(dentry); | |
233 | struct kobject * kobj = to_kobj(dentry->d_parent); | |
234 | struct sysfs_ops * ops = buffer->ops; | |
235 | ||
236 | return ops->store(kobj,attr,buffer->page,count); | |
237 | } | |
238 | ||
239 | ||
240 | /** | |
241 | * sysfs_write_file - write an attribute. | |
242 | * @file: file pointer | |
243 | * @buf: data to write | |
244 | * @count: number of bytes | |
245 | * @ppos: starting offset | |
246 | * | |
247 | * Similar to sysfs_read_file(), though working in the opposite direction. | |
248 | * We allocate and fill the data from the user in fill_write_buffer(), | |
249 | * then push it to the kobject in flush_write_buffer(). | |
250 | * There is no easy way for us to know if userspace is only doing a partial | |
251 | * write, so we don't support them. We expect the entire buffer to come | |
252 | * on the first write. | |
253 | * Hint: if you're writing a value, first read the file, modify only the | |
254 | * the value you're changing, then write entire buffer back. | |
255 | */ | |
256 | ||
257 | static ssize_t | |
258 | sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
259 | { | |
260 | struct sysfs_buffer * buffer = file->private_data; | |
261 | ssize_t len; | |
262 | ||
263 | down(&buffer->sem); | |
94bebf4d ON |
264 | if (buffer->orphaned) { |
265 | len = -ENODEV; | |
266 | goto out; | |
267 | } | |
1da177e4 LT |
268 | len = fill_write_buffer(buffer, buf, count); |
269 | if (len > 0) | |
f427f5d5 | 270 | len = flush_write_buffer(file->f_path.dentry, buffer, len); |
1da177e4 LT |
271 | if (len > 0) |
272 | *ppos += len; | |
94bebf4d | 273 | out: |
1da177e4 LT |
274 | up(&buffer->sem); |
275 | return len; | |
276 | } | |
277 | ||
94bebf4d | 278 | static int sysfs_open_file(struct inode *inode, struct file *file) |
1da177e4 | 279 | { |
f427f5d5 JJS |
280 | struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent); |
281 | struct attribute * attr = to_attr(file->f_path.dentry); | |
94bebf4d | 282 | struct sysfs_buffer_collection *set; |
1da177e4 LT |
283 | struct sysfs_buffer * buffer; |
284 | struct sysfs_ops * ops = NULL; | |
285 | int error = 0; | |
286 | ||
287 | if (!kobj || !attr) | |
288 | goto Einval; | |
289 | ||
290 | /* Grab the module reference for this attribute if we have one */ | |
291 | if (!try_module_get(attr->owner)) { | |
292 | error = -ENODEV; | |
293 | goto Done; | |
294 | } | |
295 | ||
296 | /* if the kobject has no ktype, then we assume that it is a subsystem | |
297 | * itself, and use ops for it. | |
298 | */ | |
299 | if (kobj->kset && kobj->kset->ktype) | |
300 | ops = kobj->kset->ktype->sysfs_ops; | |
301 | else if (kobj->ktype) | |
302 | ops = kobj->ktype->sysfs_ops; | |
303 | else | |
304 | ops = &subsys_sysfs_ops; | |
305 | ||
306 | /* No sysfs operations, either from having no subsystem, | |
307 | * or the subsystem have no operations. | |
308 | */ | |
309 | if (!ops) | |
310 | goto Eaccess; | |
311 | ||
94bebf4d ON |
312 | /* make sure we have a collection to add our buffers to */ |
313 | mutex_lock(&inode->i_mutex); | |
314 | if (!(set = inode->i_private)) { | |
315 | if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL))) { | |
316 | error = -ENOMEM; | |
317 | goto Done; | |
318 | } else { | |
319 | INIT_LIST_HEAD(&set->associates); | |
320 | } | |
321 | } | |
322 | mutex_unlock(&inode->i_mutex); | |
323 | ||
1da177e4 LT |
324 | /* File needs write support. |
325 | * The inode's perms must say it's ok, | |
326 | * and we must have a store method. | |
327 | */ | |
328 | if (file->f_mode & FMODE_WRITE) { | |
329 | ||
330 | if (!(inode->i_mode & S_IWUGO) || !ops->store) | |
331 | goto Eaccess; | |
332 | ||
333 | } | |
334 | ||
335 | /* File needs read support. | |
336 | * The inode's perms must say it's ok, and we there | |
337 | * must be a show method for it. | |
338 | */ | |
339 | if (file->f_mode & FMODE_READ) { | |
340 | if (!(inode->i_mode & S_IRUGO) || !ops->show) | |
341 | goto Eaccess; | |
342 | } | |
343 | ||
344 | /* No error? Great, allocate a buffer for the file, and store it | |
345 | * it in file->private_data for easy access. | |
346 | */ | |
58d49283 | 347 | buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL); |
1da177e4 | 348 | if (buffer) { |
94bebf4d | 349 | INIT_LIST_HEAD(&buffer->associates); |
1da177e4 LT |
350 | init_MUTEX(&buffer->sem); |
351 | buffer->needs_read_fill = 1; | |
352 | buffer->ops = ops; | |
94bebf4d | 353 | add_to_collection(buffer, inode); |
1da177e4 LT |
354 | file->private_data = buffer; |
355 | } else | |
356 | error = -ENOMEM; | |
357 | goto Done; | |
358 | ||
359 | Einval: | |
360 | error = -EINVAL; | |
361 | goto Done; | |
362 | Eaccess: | |
363 | error = -EACCES; | |
364 | module_put(attr->owner); | |
365 | Done: | |
f7506536 | 366 | if (error) |
1da177e4 LT |
367 | kobject_put(kobj); |
368 | return error; | |
369 | } | |
370 | ||
1da177e4 LT |
371 | static int sysfs_release(struct inode * inode, struct file * filp) |
372 | { | |
f427f5d5 JJS |
373 | struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent); |
374 | struct attribute * attr = to_attr(filp->f_path.dentry); | |
1da177e4 LT |
375 | struct module * owner = attr->owner; |
376 | struct sysfs_buffer * buffer = filp->private_data; | |
377 | ||
94bebf4d ON |
378 | if (buffer) |
379 | remove_from_collection(buffer, inode); | |
f7506536 | 380 | kobject_put(kobj); |
1da177e4 LT |
381 | /* After this point, attr should not be accessed. */ |
382 | module_put(owner); | |
383 | ||
384 | if (buffer) { | |
385 | if (buffer->page) | |
386 | free_page((unsigned long)buffer->page); | |
387 | kfree(buffer); | |
388 | } | |
389 | return 0; | |
390 | } | |
391 | ||
4508a7a7 N |
392 | /* Sysfs attribute files are pollable. The idea is that you read |
393 | * the content and then you use 'poll' or 'select' to wait for | |
394 | * the content to change. When the content changes (assuming the | |
395 | * manager for the kobject supports notification), poll will | |
396 | * return POLLERR|POLLPRI, and select will return the fd whether | |
397 | * it is waiting for read, write, or exceptions. | |
398 | * Once poll/select indicates that the value has changed, you | |
399 | * need to close and re-open the file, as simply seeking and reading | |
400 | * again will not get new data, or reset the state of 'poll'. | |
401 | * Reminder: this only works for attributes which actively support | |
402 | * it, and it is not possible to test an attribute from userspace | |
403 | * to see if it supports poll (Nether 'poll' or 'select' return | |
404 | * an appropriate error code). When in doubt, set a suitable timeout value. | |
405 | */ | |
406 | static unsigned int sysfs_poll(struct file *filp, poll_table *wait) | |
407 | { | |
408 | struct sysfs_buffer * buffer = filp->private_data; | |
f427f5d5 JJS |
409 | struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent); |
410 | struct sysfs_dirent * sd = filp->f_path.dentry->d_fsdata; | |
4508a7a7 N |
411 | int res = 0; |
412 | ||
413 | poll_wait(filp, &kobj->poll, wait); | |
414 | ||
415 | if (buffer->event != atomic_read(&sd->s_event)) { | |
416 | res = POLLERR|POLLPRI; | |
417 | buffer->needs_read_fill = 1; | |
418 | } | |
419 | ||
420 | return res; | |
421 | } | |
422 | ||
423 | ||
424 | static struct dentry *step_down(struct dentry *dir, const char * name) | |
425 | { | |
426 | struct dentry * de; | |
427 | ||
428 | if (dir == NULL || dir->d_inode == NULL) | |
429 | return NULL; | |
430 | ||
431 | mutex_lock(&dir->d_inode->i_mutex); | |
432 | de = lookup_one_len(name, dir, strlen(name)); | |
433 | mutex_unlock(&dir->d_inode->i_mutex); | |
434 | dput(dir); | |
435 | if (IS_ERR(de)) | |
436 | return NULL; | |
437 | if (de->d_inode == NULL) { | |
438 | dput(de); | |
439 | return NULL; | |
440 | } | |
441 | return de; | |
442 | } | |
443 | ||
444 | void sysfs_notify(struct kobject * k, char *dir, char *attr) | |
445 | { | |
446 | struct dentry *de = k->dentry; | |
447 | if (de) | |
448 | dget(de); | |
449 | if (de && dir) | |
450 | de = step_down(de, dir); | |
451 | if (de && attr) | |
452 | de = step_down(de, attr); | |
453 | if (de) { | |
454 | struct sysfs_dirent * sd = de->d_fsdata; | |
455 | if (sd) | |
456 | atomic_inc(&sd->s_event); | |
457 | wake_up_interruptible(&k->poll); | |
458 | dput(de); | |
459 | } | |
460 | } | |
461 | EXPORT_SYMBOL_GPL(sysfs_notify); | |
462 | ||
4b6f5d20 | 463 | const struct file_operations sysfs_file_operations = { |
1da177e4 LT |
464 | .read = sysfs_read_file, |
465 | .write = sysfs_write_file, | |
466 | .llseek = generic_file_llseek, | |
467 | .open = sysfs_open_file, | |
468 | .release = sysfs_release, | |
4508a7a7 | 469 | .poll = sysfs_poll, |
1da177e4 LT |
470 | }; |
471 | ||
472 | ||
473 | int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type) | |
474 | { | |
475 | struct sysfs_dirent * parent_sd = dir->d_fsdata; | |
476 | umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; | |
c516865c | 477 | int error = -EEXIST; |
1da177e4 | 478 | |
1b1dcc1b | 479 | mutex_lock(&dir->d_inode->i_mutex); |
c516865c MS |
480 | if (!sysfs_dirent_exist(parent_sd, attr->name)) |
481 | error = sysfs_make_dirent(parent_sd, NULL, (void *)attr, | |
482 | mode, type); | |
1b1dcc1b | 483 | mutex_unlock(&dir->d_inode->i_mutex); |
1da177e4 LT |
484 | |
485 | return error; | |
486 | } | |
487 | ||
488 | ||
489 | /** | |
490 | * sysfs_create_file - create an attribute file for an object. | |
491 | * @kobj: object we're creating for. | |
492 | * @attr: atrribute descriptor. | |
493 | */ | |
494 | ||
495 | int sysfs_create_file(struct kobject * kobj, const struct attribute * attr) | |
496 | { | |
497 | BUG_ON(!kobj || !kobj->dentry || !attr); | |
498 | ||
499 | return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR); | |
500 | ||
501 | } | |
502 | ||
503 | ||
504 | /** | |
505 | * sysfs_update_file - update the modified timestamp on an object attribute. | |
506 | * @kobj: object we're acting for. | |
507 | * @attr: attribute descriptor. | |
1da177e4 LT |
508 | */ |
509 | int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) | |
510 | { | |
511 | struct dentry * dir = kobj->dentry; | |
512 | struct dentry * victim; | |
513 | int res = -ENOENT; | |
514 | ||
1b1dcc1b | 515 | mutex_lock(&dir->d_inode->i_mutex); |
5f45f1a7 | 516 | victim = lookup_one_len(attr->name, dir, strlen(attr->name)); |
1da177e4 LT |
517 | if (!IS_ERR(victim)) { |
518 | /* make sure dentry is really there */ | |
519 | if (victim->d_inode && | |
520 | (victim->d_parent->d_inode == dir->d_inode)) { | |
521 | victim->d_inode->i_mtime = CURRENT_TIME; | |
0eeca283 | 522 | fsnotify_modify(victim); |
1da177e4 LT |
523 | res = 0; |
524 | } else | |
525 | d_drop(victim); | |
526 | ||
527 | /** | |
97a50184 | 528 | * Drop the reference acquired from lookup_one_len() above. |
1da177e4 LT |
529 | */ |
530 | dput(victim); | |
531 | } | |
1b1dcc1b | 532 | mutex_unlock(&dir->d_inode->i_mutex); |
1da177e4 LT |
533 | |
534 | return res; | |
535 | } | |
536 | ||
537 | ||
31e5abe9 KS |
538 | /** |
539 | * sysfs_chmod_file - update the modified mode value on an object attribute. | |
540 | * @kobj: object we're acting for. | |
541 | * @attr: attribute descriptor. | |
542 | * @mode: file permissions. | |
543 | * | |
544 | */ | |
545 | int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) | |
546 | { | |
547 | struct dentry *dir = kobj->dentry; | |
548 | struct dentry *victim; | |
bc062b1b MS |
549 | struct inode * inode; |
550 | struct iattr newattrs; | |
31e5abe9 KS |
551 | int res = -ENOENT; |
552 | ||
1b1dcc1b | 553 | mutex_lock(&dir->d_inode->i_mutex); |
5f45f1a7 | 554 | victim = lookup_one_len(attr->name, dir, strlen(attr->name)); |
31e5abe9 KS |
555 | if (!IS_ERR(victim)) { |
556 | if (victim->d_inode && | |
557 | (victim->d_parent->d_inode == dir->d_inode)) { | |
bc062b1b | 558 | inode = victim->d_inode; |
1b1dcc1b | 559 | mutex_lock(&inode->i_mutex); |
bc062b1b MS |
560 | newattrs.ia_mode = (mode & S_IALLUGO) | |
561 | (inode->i_mode & ~S_IALLUGO); | |
562 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
563 | res = notify_change(victim, &newattrs); | |
1b1dcc1b | 564 | mutex_unlock(&inode->i_mutex); |
31e5abe9 | 565 | } |
bc062b1b | 566 | dput(victim); |
31e5abe9 | 567 | } |
1b1dcc1b | 568 | mutex_unlock(&dir->d_inode->i_mutex); |
31e5abe9 KS |
569 | |
570 | return res; | |
571 | } | |
572 | EXPORT_SYMBOL_GPL(sysfs_chmod_file); | |
573 | ||
574 | ||
1da177e4 LT |
575 | /** |
576 | * sysfs_remove_file - remove an object attribute. | |
577 | * @kobj: object we're acting for. | |
578 | * @attr: attribute descriptor. | |
579 | * | |
580 | * Hash the attribute name and kill the victim. | |
581 | */ | |
582 | ||
583 | void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr) | |
584 | { | |
94bebf4d | 585 | sysfs_hash_and_remove(kobj->dentry, attr->name); |
1da177e4 LT |
586 | } |
587 | ||
588 | ||
589 | EXPORT_SYMBOL_GPL(sysfs_create_file); | |
590 | EXPORT_SYMBOL_GPL(sysfs_remove_file); | |
591 | EXPORT_SYMBOL_GPL(sysfs_update_file); |