Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
6d66f5cd TH |
2 | * fs/sysfs/file.c - sysfs regular (text) file implementation |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | * | |
10 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #include <linux/module.h> | |
1da177e4 | 14 | #include <linux/kobject.h> |
815d2d50 | 15 | #include <linux/kallsyms.h> |
c6f87733 | 16 | #include <linux/slab.h> |
93265d13 | 17 | #include <linux/fsnotify.h> |
5f45f1a7 | 18 | #include <linux/namei.h> |
4508a7a7 | 19 | #include <linux/poll.h> |
94bebf4d | 20 | #include <linux/list.h> |
52e8c209 | 21 | #include <linux/mutex.h> |
ae87221d | 22 | #include <linux/limits.h> |
060cc749 | 23 | #include <linux/uaccess.h> |
13c589d5 | 24 | #include <linux/seq_file.h> |
73d97146 | 25 | #include <linux/mm.h> |
1da177e4 LT |
26 | |
27 | #include "sysfs.h" | |
28 | ||
85a4ffad | 29 | /* |
58282d8d | 30 | * There's one sysfs_open_file for each open file and one sysfs_open_dirent |
c75ec764 | 31 | * for each sysfs_dirent with one or more open files. |
85a4ffad | 32 | * |
c75ec764 TH |
33 | * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is |
34 | * protected by sysfs_open_dirent_lock. | |
35 | * | |
13c589d5 TH |
36 | * filp->private_data points to seq_file whose ->private points to |
37 | * sysfs_open_file. sysfs_open_files are chained at | |
58282d8d | 38 | * sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex. |
85a4ffad | 39 | */ |
d7b37889 | 40 | static DEFINE_SPINLOCK(sysfs_open_dirent_lock); |
c75ec764 | 41 | static DEFINE_MUTEX(sysfs_open_file_mutex); |
85a4ffad TH |
42 | |
43 | struct sysfs_open_dirent { | |
44 | atomic_t refcnt; | |
a4e8b912 TH |
45 | atomic_t event; |
46 | wait_queue_head_t poll; | |
58282d8d | 47 | struct list_head files; /* goes through sysfs_open_file.list */ |
85a4ffad TH |
48 | }; |
49 | ||
f9b9a621 TH |
50 | static bool sysfs_is_bin(struct sysfs_dirent *sd) |
51 | { | |
52 | return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR; | |
53 | } | |
54 | ||
13c589d5 TH |
55 | static struct sysfs_open_file *sysfs_of(struct file *file) |
56 | { | |
57 | return ((struct seq_file *)file->private_data)->private; | |
58 | } | |
59 | ||
f6acf8bb TH |
60 | /* |
61 | * Determine the kernfs_ops for the given sysfs_dirent. This function must | |
62 | * be called while holding an active reference. | |
63 | */ | |
64 | static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) | |
65 | { | |
66 | if (!sysfs_ignore_lockdep(sd)) | |
67 | lockdep_assert_held(sd); | |
68 | return sd->s_attr.ops; | |
69 | } | |
70 | ||
375b611e TH |
71 | /* |
72 | * Determine ktype->sysfs_ops for the given sysfs_dirent. This function | |
73 | * must be called while holding an active reference. | |
74 | */ | |
75 | static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) | |
76 | { | |
7c6e2d36 | 77 | struct kobject *kobj = sd->s_parent->priv; |
375b611e | 78 | |
785a162d TH |
79 | if (!sysfs_ignore_lockdep(sd)) |
80 | lockdep_assert_held(sd); | |
375b611e TH |
81 | return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; |
82 | } | |
83 | ||
13c589d5 TH |
84 | /* |
85 | * Reads on sysfs are handled through seq_file, which takes care of hairy | |
86 | * details like buffering and seeking. The following function pipes | |
87 | * sysfs_ops->show() result through seq_file. | |
1da177e4 | 88 | */ |
c2b19daf | 89 | static int sysfs_kf_seq_show(struct seq_file *sf, void *v) |
1da177e4 | 90 | { |
13c589d5 | 91 | struct sysfs_open_file *of = sf->private; |
7c6e2d36 | 92 | struct kobject *kobj = of->sd->s_parent->priv; |
c2b19daf | 93 | const struct sysfs_ops *ops = sysfs_file_ops(of->sd); |
1da177e4 | 94 | ssize_t count; |
c2b19daf | 95 | char *buf; |
1da177e4 | 96 | |
13c589d5 TH |
97 | /* acquire buffer and ensure that it's >= PAGE_SIZE */ |
98 | count = seq_get_buf(sf, &buf); | |
99 | if (count < PAGE_SIZE) { | |
100 | seq_commit(sf, -1); | |
101 | return 0; | |
102 | } | |
1da177e4 | 103 | |
13c589d5 | 104 | /* |
c2b19daf TH |
105 | * Invoke show(). Control may reach here via seq file lseek even |
106 | * if @ops->show() isn't implemented. | |
13c589d5 | 107 | */ |
c2b19daf | 108 | if (ops->show) { |
7c6e2d36 | 109 | count = ops->show(kobj, of->sd->priv, buf); |
c2b19daf TH |
110 | if (count < 0) |
111 | return count; | |
112 | } | |
0ab66088 | 113 | |
8118a859 MX |
114 | /* |
115 | * The code works fine with PAGE_SIZE return but it's likely to | |
116 | * indicate truncated result or overflow in normal use cases. | |
117 | */ | |
815d2d50 AM |
118 | if (count >= (ssize_t)PAGE_SIZE) { |
119 | print_symbol("fill_read_buffer: %s returned bad count\n", | |
120 | (unsigned long)ops->show); | |
121 | /* Try to struggle along */ | |
122 | count = PAGE_SIZE - 1; | |
123 | } | |
13c589d5 TH |
124 | seq_commit(sf, count); |
125 | return 0; | |
1da177e4 LT |
126 | } |
127 | ||
c2b19daf TH |
128 | static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, |
129 | size_t count, loff_t pos) | |
2f0c6b75 | 130 | { |
7c6e2d36 TH |
131 | struct bin_attribute *battr = of->sd->priv; |
132 | struct kobject *kobj = of->sd->s_parent->priv; | |
c2b19daf | 133 | loff_t size = file_inode(of->file)->i_size; |
2f0c6b75 | 134 | |
c2b19daf | 135 | if (!count) |
2f0c6b75 TH |
136 | return 0; |
137 | ||
138 | if (size) { | |
c2b19daf | 139 | if (pos > size) |
2f0c6b75 | 140 | return 0; |
c2b19daf TH |
141 | if (pos + count > size) |
142 | count = size - pos; | |
2f0c6b75 TH |
143 | } |
144 | ||
c2b19daf TH |
145 | if (!battr->read) |
146 | return -EIO; | |
147 | ||
148 | return battr->read(of->file, kobj, battr, buf, pos, count); | |
149 | } | |
150 | ||
151 | static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) | |
152 | { | |
153 | struct sysfs_open_file *of = sf->private; | |
154 | ||
155 | /* | |
156 | * @of->mutex nests outside active ref and is just to ensure that | |
157 | * the ops aren't called concurrently for the same open file. | |
158 | */ | |
159 | mutex_lock(&of->mutex); | |
160 | if (!sysfs_get_active(of->sd)) | |
161 | return ERR_PTR(-ENODEV); | |
162 | ||
163 | /* | |
164 | * The same behavior and code as single_open(). Returns !NULL if | |
165 | * pos is at the beginning; otherwise, NULL. | |
166 | */ | |
167 | return NULL + !*ppos; | |
168 | } | |
169 | ||
170 | static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) | |
171 | { | |
172 | /* | |
173 | * The same behavior and code as single_open(), always terminate | |
174 | * after the initial read. | |
175 | */ | |
176 | ++*ppos; | |
177 | return NULL; | |
178 | } | |
179 | ||
180 | static void kernfs_seq_stop(struct seq_file *sf, void *v) | |
181 | { | |
182 | struct sysfs_open_file *of = sf->private; | |
183 | ||
184 | sysfs_put_active(of->sd); | |
185 | mutex_unlock(&of->mutex); | |
186 | } | |
187 | ||
188 | static int kernfs_seq_show(struct seq_file *sf, void *v) | |
189 | { | |
190 | struct sysfs_open_file *of = sf->private; | |
191 | ||
192 | of->event = atomic_read(&of->sd->s_attr.open->event); | |
193 | ||
f6acf8bb | 194 | return of->sd->s_attr.ops->seq_show(sf, v); |
c2b19daf TH |
195 | } |
196 | ||
197 | static const struct seq_operations kernfs_seq_ops = { | |
198 | .start = kernfs_seq_start, | |
199 | .next = kernfs_seq_next, | |
200 | .stop = kernfs_seq_stop, | |
201 | .show = kernfs_seq_show, | |
202 | }; | |
203 | ||
204 | /* | |
205 | * As reading a bin file can have side-effects, the exact offset and bytes | |
206 | * specified in read(2) call should be passed to the read callback making | |
207 | * it difficult to use seq_file. Implement simplistic custom buffering for | |
208 | * bin files. | |
209 | */ | |
210 | static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, | |
211 | char __user *user_buf, size_t count, | |
212 | loff_t *ppos) | |
213 | { | |
214 | ssize_t len = min_t(size_t, count, PAGE_SIZE); | |
f6acf8bb | 215 | const struct kernfs_ops *ops; |
c2b19daf TH |
216 | char *buf; |
217 | ||
218 | buf = kmalloc(len, GFP_KERNEL); | |
2f0c6b75 TH |
219 | if (!buf) |
220 | return -ENOMEM; | |
221 | ||
c2b19daf TH |
222 | /* |
223 | * @of->mutex nests outside active ref and is just to ensure that | |
224 | * the ops aren't called concurrently for the same open file. | |
225 | */ | |
2f0c6b75 TH |
226 | mutex_lock(&of->mutex); |
227 | if (!sysfs_get_active(of->sd)) { | |
c2b19daf | 228 | len = -ENODEV; |
2f0c6b75 TH |
229 | mutex_unlock(&of->mutex); |
230 | goto out_free; | |
231 | } | |
232 | ||
f6acf8bb TH |
233 | ops = kernfs_ops(of->sd); |
234 | if (ops->read) | |
235 | len = ops->read(of, buf, len, *ppos); | |
236 | else | |
237 | len = -EINVAL; | |
2f0c6b75 TH |
238 | |
239 | sysfs_put_active(of->sd); | |
240 | mutex_unlock(&of->mutex); | |
241 | ||
c2b19daf | 242 | if (len < 0) |
2f0c6b75 TH |
243 | goto out_free; |
244 | ||
c2b19daf TH |
245 | if (copy_to_user(user_buf, buf, len)) { |
246 | len = -EFAULT; | |
2f0c6b75 TH |
247 | goto out_free; |
248 | } | |
249 | ||
c2b19daf | 250 | *ppos += len; |
2f0c6b75 TH |
251 | |
252 | out_free: | |
253 | kfree(buf); | |
c2b19daf TH |
254 | return len; |
255 | } | |
256 | ||
257 | /** | |
258 | * kernfs_file_read - kernfs vfs read callback | |
259 | * @file: file pointer | |
260 | * @user_buf: data to write | |
261 | * @count: number of bytes | |
262 | * @ppos: starting offset | |
263 | */ | |
264 | static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, | |
265 | size_t count, loff_t *ppos) | |
266 | { | |
267 | struct sysfs_open_file *of = sysfs_of(file); | |
268 | ||
f6acf8bb | 269 | if (of->sd->s_flags & SYSFS_FLAG_HAS_SEQ_SHOW) |
c2b19daf | 270 | return seq_read(file, user_buf, count, ppos); |
f6acf8bb TH |
271 | else |
272 | return kernfs_file_direct_read(of, user_buf, count, ppos); | |
2f0c6b75 TH |
273 | } |
274 | ||
50b38ca0 TH |
275 | /* kernfs write callback for regular sysfs files */ |
276 | static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, | |
277 | size_t count, loff_t pos) | |
1da177e4 | 278 | { |
50b38ca0 | 279 | const struct sysfs_ops *ops = sysfs_file_ops(of->sd); |
7c6e2d36 | 280 | struct kobject *kobj = of->sd->s_parent->priv; |
0ab66088 | 281 | |
50b38ca0 TH |
282 | if (!count) |
283 | return 0; | |
0ab66088 | 284 | |
50b38ca0 TH |
285 | return ops->store(kobj, of->sd->priv, buf, count); |
286 | } | |
f9b9a621 | 287 | |
50b38ca0 TH |
288 | /* kernfs write callback for bin sysfs files */ |
289 | static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, | |
290 | size_t count, loff_t pos) | |
291 | { | |
292 | struct bin_attribute *battr = of->sd->priv; | |
293 | struct kobject *kobj = of->sd->s_parent->priv; | |
294 | loff_t size = file_inode(of->file)->i_size; | |
f9b9a621 | 295 | |
50b38ca0 TH |
296 | if (size) { |
297 | if (size <= pos) | |
298 | return 0; | |
299 | count = min_t(ssize_t, count, size - pos); | |
f9b9a621 | 300 | } |
50b38ca0 TH |
301 | if (!count) |
302 | return 0; | |
0ab66088 | 303 | |
50b38ca0 TH |
304 | if (!battr->write) |
305 | return -EIO; | |
1da177e4 | 306 | |
50b38ca0 | 307 | return battr->write(of->file, kobj, battr, buf, pos, count); |
1da177e4 LT |
308 | } |
309 | ||
1da177e4 | 310 | /** |
50b38ca0 | 311 | * kernfs_file_write - kernfs vfs write callback |
8ef445f0 TH |
312 | * @file: file pointer |
313 | * @user_buf: data to write | |
314 | * @count: number of bytes | |
315 | * @ppos: starting offset | |
316 | * | |
50b38ca0 TH |
317 | * Copy data in from userland and pass it to the matching kernfs write |
318 | * operation. | |
1da177e4 | 319 | * |
8ef445f0 TH |
320 | * There is no easy way for us to know if userspace is only doing a partial |
321 | * write, so we don't support them. We expect the entire buffer to come on | |
322 | * the first write. Hint: if you're writing a value, first read the file, | |
323 | * modify only the the value you're changing, then write entire buffer | |
324 | * back. | |
1da177e4 | 325 | */ |
50b38ca0 TH |
326 | static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, |
327 | size_t count, loff_t *ppos) | |
1da177e4 | 328 | { |
13c589d5 | 329 | struct sysfs_open_file *of = sysfs_of(file); |
f9b9a621 | 330 | ssize_t len = min_t(size_t, count, PAGE_SIZE); |
f6acf8bb | 331 | const struct kernfs_ops *ops; |
8ef445f0 | 332 | char *buf; |
1da177e4 | 333 | |
8ef445f0 TH |
334 | buf = kmalloc(len + 1, GFP_KERNEL); |
335 | if (!buf) | |
336 | return -ENOMEM; | |
337 | ||
338 | if (copy_from_user(buf, user_buf, len)) { | |
339 | len = -EFAULT; | |
340 | goto out_free; | |
341 | } | |
342 | buf[len] = '\0'; /* guarantee string termination */ | |
343 | ||
50b38ca0 TH |
344 | /* |
345 | * @of->mutex nests outside active ref and is just to ensure that | |
346 | * the ops aren't called concurrently for the same open file. | |
347 | */ | |
348 | mutex_lock(&of->mutex); | |
349 | if (!sysfs_get_active(of->sd)) { | |
350 | mutex_unlock(&of->mutex); | |
351 | len = -ENODEV; | |
352 | goto out_free; | |
353 | } | |
354 | ||
f6acf8bb TH |
355 | ops = kernfs_ops(of->sd); |
356 | if (ops->write) | |
357 | len = ops->write(of, buf, len, *ppos); | |
50b38ca0 | 358 | else |
f6acf8bb | 359 | len = -EINVAL; |
50b38ca0 TH |
360 | |
361 | sysfs_put_active(of->sd); | |
362 | mutex_unlock(&of->mutex); | |
363 | ||
1da177e4 LT |
364 | if (len > 0) |
365 | *ppos += len; | |
8ef445f0 TH |
366 | out_free: |
367 | kfree(buf); | |
1da177e4 LT |
368 | return len; |
369 | } | |
370 | ||
fdbffaa4 TH |
371 | static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, |
372 | struct vm_area_struct *vma) | |
373 | { | |
374 | struct bin_attribute *battr = of->sd->priv; | |
375 | struct kobject *kobj = of->sd->s_parent->priv; | |
376 | ||
377 | if (!battr->mmap) | |
378 | return -ENODEV; | |
379 | ||
380 | return battr->mmap(of->file, kobj, battr, vma); | |
381 | } | |
382 | ||
383 | static void kernfs_vma_open(struct vm_area_struct *vma) | |
73d97146 TH |
384 | { |
385 | struct file *file = vma->vm_file; | |
386 | struct sysfs_open_file *of = sysfs_of(file); | |
387 | ||
388 | if (!of->vm_ops) | |
389 | return; | |
390 | ||
391 | if (!sysfs_get_active(of->sd)) | |
392 | return; | |
393 | ||
394 | if (of->vm_ops->open) | |
395 | of->vm_ops->open(vma); | |
396 | ||
397 | sysfs_put_active(of->sd); | |
398 | } | |
399 | ||
fdbffaa4 | 400 | static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
73d97146 TH |
401 | { |
402 | struct file *file = vma->vm_file; | |
403 | struct sysfs_open_file *of = sysfs_of(file); | |
404 | int ret; | |
405 | ||
406 | if (!of->vm_ops) | |
407 | return VM_FAULT_SIGBUS; | |
408 | ||
409 | if (!sysfs_get_active(of->sd)) | |
410 | return VM_FAULT_SIGBUS; | |
411 | ||
412 | ret = VM_FAULT_SIGBUS; | |
413 | if (of->vm_ops->fault) | |
414 | ret = of->vm_ops->fault(vma, vmf); | |
415 | ||
416 | sysfs_put_active(of->sd); | |
417 | return ret; | |
418 | } | |
419 | ||
fdbffaa4 TH |
420 | static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma, |
421 | struct vm_fault *vmf) | |
73d97146 TH |
422 | { |
423 | struct file *file = vma->vm_file; | |
424 | struct sysfs_open_file *of = sysfs_of(file); | |
425 | int ret; | |
426 | ||
427 | if (!of->vm_ops) | |
428 | return VM_FAULT_SIGBUS; | |
429 | ||
430 | if (!sysfs_get_active(of->sd)) | |
431 | return VM_FAULT_SIGBUS; | |
432 | ||
433 | ret = 0; | |
434 | if (of->vm_ops->page_mkwrite) | |
435 | ret = of->vm_ops->page_mkwrite(vma, vmf); | |
436 | else | |
437 | file_update_time(file); | |
438 | ||
439 | sysfs_put_active(of->sd); | |
440 | return ret; | |
441 | } | |
442 | ||
fdbffaa4 TH |
443 | static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr, |
444 | void *buf, int len, int write) | |
73d97146 TH |
445 | { |
446 | struct file *file = vma->vm_file; | |
447 | struct sysfs_open_file *of = sysfs_of(file); | |
448 | int ret; | |
449 | ||
450 | if (!of->vm_ops) | |
451 | return -EINVAL; | |
452 | ||
453 | if (!sysfs_get_active(of->sd)) | |
454 | return -EINVAL; | |
455 | ||
456 | ret = -EINVAL; | |
457 | if (of->vm_ops->access) | |
458 | ret = of->vm_ops->access(vma, addr, buf, len, write); | |
459 | ||
460 | sysfs_put_active(of->sd); | |
461 | return ret; | |
462 | } | |
463 | ||
464 | #ifdef CONFIG_NUMA | |
fdbffaa4 TH |
465 | static int kernfs_vma_set_policy(struct vm_area_struct *vma, |
466 | struct mempolicy *new) | |
73d97146 TH |
467 | { |
468 | struct file *file = vma->vm_file; | |
469 | struct sysfs_open_file *of = sysfs_of(file); | |
470 | int ret; | |
471 | ||
472 | if (!of->vm_ops) | |
473 | return 0; | |
474 | ||
475 | if (!sysfs_get_active(of->sd)) | |
476 | return -EINVAL; | |
477 | ||
478 | ret = 0; | |
479 | if (of->vm_ops->set_policy) | |
480 | ret = of->vm_ops->set_policy(vma, new); | |
481 | ||
482 | sysfs_put_active(of->sd); | |
483 | return ret; | |
484 | } | |
485 | ||
fdbffaa4 TH |
486 | static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, |
487 | unsigned long addr) | |
73d97146 TH |
488 | { |
489 | struct file *file = vma->vm_file; | |
490 | struct sysfs_open_file *of = sysfs_of(file); | |
491 | struct mempolicy *pol; | |
492 | ||
493 | if (!of->vm_ops) | |
494 | return vma->vm_policy; | |
495 | ||
496 | if (!sysfs_get_active(of->sd)) | |
497 | return vma->vm_policy; | |
498 | ||
499 | pol = vma->vm_policy; | |
500 | if (of->vm_ops->get_policy) | |
501 | pol = of->vm_ops->get_policy(vma, addr); | |
502 | ||
503 | sysfs_put_active(of->sd); | |
504 | return pol; | |
505 | } | |
506 | ||
fdbffaa4 TH |
507 | static int kernfs_vma_migrate(struct vm_area_struct *vma, |
508 | const nodemask_t *from, const nodemask_t *to, | |
509 | unsigned long flags) | |
73d97146 TH |
510 | { |
511 | struct file *file = vma->vm_file; | |
512 | struct sysfs_open_file *of = sysfs_of(file); | |
513 | int ret; | |
514 | ||
515 | if (!of->vm_ops) | |
516 | return 0; | |
517 | ||
518 | if (!sysfs_get_active(of->sd)) | |
519 | return 0; | |
520 | ||
521 | ret = 0; | |
522 | if (of->vm_ops->migrate) | |
523 | ret = of->vm_ops->migrate(vma, from, to, flags); | |
524 | ||
525 | sysfs_put_active(of->sd); | |
526 | return ret; | |
527 | } | |
528 | #endif | |
529 | ||
fdbffaa4 TH |
530 | static const struct vm_operations_struct kernfs_vm_ops = { |
531 | .open = kernfs_vma_open, | |
532 | .fault = kernfs_vma_fault, | |
533 | .page_mkwrite = kernfs_vma_page_mkwrite, | |
534 | .access = kernfs_vma_access, | |
73d97146 | 535 | #ifdef CONFIG_NUMA |
fdbffaa4 TH |
536 | .set_policy = kernfs_vma_set_policy, |
537 | .get_policy = kernfs_vma_get_policy, | |
538 | .migrate = kernfs_vma_migrate, | |
73d97146 TH |
539 | #endif |
540 | }; | |
541 | ||
fdbffaa4 | 542 | static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
73d97146 TH |
543 | { |
544 | struct sysfs_open_file *of = sysfs_of(file); | |
f6acf8bb | 545 | const struct kernfs_ops *ops; |
73d97146 TH |
546 | int rc; |
547 | ||
548 | mutex_lock(&of->mutex); | |
549 | ||
73d97146 TH |
550 | rc = -ENODEV; |
551 | if (!sysfs_get_active(of->sd)) | |
552 | goto out_unlock; | |
553 | ||
f6acf8bb TH |
554 | ops = kernfs_ops(of->sd); |
555 | if (ops->mmap) | |
556 | rc = ops->mmap(of, vma); | |
73d97146 TH |
557 | if (rc) |
558 | goto out_put; | |
559 | ||
560 | /* | |
561 | * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() | |
562 | * to satisfy versions of X which crash if the mmap fails: that | |
563 | * substitutes a new vm_file, and we don't then want bin_vm_ops. | |
564 | */ | |
565 | if (vma->vm_file != file) | |
566 | goto out_put; | |
567 | ||
568 | rc = -EINVAL; | |
569 | if (of->mmapped && of->vm_ops != vma->vm_ops) | |
570 | goto out_put; | |
571 | ||
572 | /* | |
573 | * It is not possible to successfully wrap close. | |
574 | * So error if someone is trying to use close. | |
575 | */ | |
576 | rc = -EINVAL; | |
577 | if (vma->vm_ops && vma->vm_ops->close) | |
578 | goto out_put; | |
579 | ||
580 | rc = 0; | |
581 | of->mmapped = 1; | |
582 | of->vm_ops = vma->vm_ops; | |
fdbffaa4 | 583 | vma->vm_ops = &kernfs_vm_ops; |
73d97146 TH |
584 | out_put: |
585 | sysfs_put_active(of->sd); | |
586 | out_unlock: | |
587 | mutex_unlock(&of->mutex); | |
588 | ||
589 | return rc; | |
590 | } | |
591 | ||
85a4ffad TH |
592 | /** |
593 | * sysfs_get_open_dirent - get or create sysfs_open_dirent | |
594 | * @sd: target sysfs_dirent | |
58282d8d | 595 | * @of: sysfs_open_file for this instance of open |
85a4ffad TH |
596 | * |
597 | * If @sd->s_attr.open exists, increment its reference count; | |
58282d8d | 598 | * otherwise, create one. @of is chained to the files list. |
85a4ffad TH |
599 | * |
600 | * LOCKING: | |
601 | * Kernel thread context (may sleep). | |
602 | * | |
603 | * RETURNS: | |
604 | * 0 on success, -errno on failure. | |
605 | */ | |
606 | static int sysfs_get_open_dirent(struct sysfs_dirent *sd, | |
58282d8d | 607 | struct sysfs_open_file *of) |
85a4ffad TH |
608 | { |
609 | struct sysfs_open_dirent *od, *new_od = NULL; | |
610 | ||
611 | retry: | |
c75ec764 | 612 | mutex_lock(&sysfs_open_file_mutex); |
83db93f4 | 613 | spin_lock_irq(&sysfs_open_dirent_lock); |
85a4ffad TH |
614 | |
615 | if (!sd->s_attr.open && new_od) { | |
616 | sd->s_attr.open = new_od; | |
617 | new_od = NULL; | |
618 | } | |
619 | ||
620 | od = sd->s_attr.open; | |
621 | if (od) { | |
622 | atomic_inc(&od->refcnt); | |
58282d8d | 623 | list_add_tail(&of->list, &od->files); |
85a4ffad TH |
624 | } |
625 | ||
83db93f4 | 626 | spin_unlock_irq(&sysfs_open_dirent_lock); |
c75ec764 | 627 | mutex_unlock(&sysfs_open_file_mutex); |
85a4ffad TH |
628 | |
629 | if (od) { | |
630 | kfree(new_od); | |
631 | return 0; | |
632 | } | |
633 | ||
634 | /* not there, initialize a new one and retry */ | |
635 | new_od = kmalloc(sizeof(*new_od), GFP_KERNEL); | |
636 | if (!new_od) | |
637 | return -ENOMEM; | |
638 | ||
639 | atomic_set(&new_od->refcnt, 0); | |
a4e8b912 TH |
640 | atomic_set(&new_od->event, 1); |
641 | init_waitqueue_head(&new_od->poll); | |
58282d8d | 642 | INIT_LIST_HEAD(&new_od->files); |
85a4ffad TH |
643 | goto retry; |
644 | } | |
645 | ||
646 | /** | |
647 | * sysfs_put_open_dirent - put sysfs_open_dirent | |
648 | * @sd: target sysfs_dirent | |
58282d8d | 649 | * @of: associated sysfs_open_file |
85a4ffad | 650 | * |
58282d8d TH |
651 | * Put @sd->s_attr.open and unlink @of from the files list. If |
652 | * reference count reaches zero, disassociate and free it. | |
85a4ffad TH |
653 | * |
654 | * LOCKING: | |
655 | * None. | |
656 | */ | |
657 | static void sysfs_put_open_dirent(struct sysfs_dirent *sd, | |
58282d8d | 658 | struct sysfs_open_file *of) |
85a4ffad TH |
659 | { |
660 | struct sysfs_open_dirent *od = sd->s_attr.open; | |
83db93f4 | 661 | unsigned long flags; |
85a4ffad | 662 | |
c75ec764 | 663 | mutex_lock(&sysfs_open_file_mutex); |
83db93f4 | 664 | spin_lock_irqsave(&sysfs_open_dirent_lock, flags); |
85a4ffad | 665 | |
73d97146 TH |
666 | if (of) |
667 | list_del(&of->list); | |
668 | ||
85a4ffad TH |
669 | if (atomic_dec_and_test(&od->refcnt)) |
670 | sd->s_attr.open = NULL; | |
671 | else | |
672 | od = NULL; | |
673 | ||
83db93f4 | 674 | spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); |
c75ec764 | 675 | mutex_unlock(&sysfs_open_file_mutex); |
85a4ffad TH |
676 | |
677 | kfree(od); | |
678 | } | |
679 | ||
c6fb4495 | 680 | static int kernfs_file_open(struct inode *inode, struct file *file) |
1da177e4 | 681 | { |
3e519038 | 682 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
f6acf8bb | 683 | const struct kernfs_ops *ops; |
58282d8d | 684 | struct sysfs_open_file *of; |
027a485d | 685 | bool has_read, has_write, has_mmap; |
000f2a4d | 686 | int error = -EACCES; |
1da177e4 | 687 | |
e72ceb8c | 688 | if (!sysfs_get_active(attr_sd)) |
0ab66088 | 689 | return -ENODEV; |
1da177e4 | 690 | |
f6acf8bb | 691 | ops = kernfs_ops(attr_sd); |
1da177e4 | 692 | |
f6acf8bb TH |
693 | has_read = ops->seq_show || ops->read || ops->mmap; |
694 | has_write = ops->write || ops->mmap; | |
695 | has_mmap = ops->mmap; | |
1da177e4 | 696 | |
49fe6047 TH |
697 | /* check perms and supported operations */ |
698 | if ((file->f_mode & FMODE_WRITE) && | |
699 | (!(inode->i_mode & S_IWUGO) || !has_write)) | |
700 | goto err_out; | |
701 | ||
702 | if ((file->f_mode & FMODE_READ) && | |
703 | (!(inode->i_mode & S_IRUGO) || !has_read)) | |
704 | goto err_out; | |
705 | ||
13c589d5 | 706 | /* allocate a sysfs_open_file for the file */ |
0ab66088 | 707 | error = -ENOMEM; |
58282d8d TH |
708 | of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL); |
709 | if (!of) | |
7b595756 | 710 | goto err_out; |
1da177e4 | 711 | |
027a485d TH |
712 | /* |
713 | * The following is done to give a different lockdep key to | |
714 | * @of->mutex for files which implement mmap. This is a rather | |
715 | * crude way to avoid false positive lockdep warning around | |
716 | * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and | |
717 | * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under | |
718 | * which mm->mmap_sem nests, while holding @of->mutex. As each | |
719 | * open file has a separate mutex, it's okay as long as those don't | |
720 | * happen on the same file. At this point, we can't easily give | |
721 | * each file a separate locking class. Let's differentiate on | |
722 | * whether the file has mmap or not for now. | |
723 | */ | |
724 | if (has_mmap) | |
725 | mutex_init(&of->mutex); | |
726 | else | |
727 | mutex_init(&of->mutex); | |
728 | ||
bcafe4ee TH |
729 | of->sd = attr_sd; |
730 | of->file = file; | |
13c589d5 TH |
731 | |
732 | /* | |
49fe6047 TH |
733 | * Always instantiate seq_file even if read access doesn't use |
734 | * seq_file or is not requested. This unifies private data access | |
735 | * and readable regular files are the vast majority anyway. | |
13c589d5 | 736 | */ |
f6acf8bb | 737 | if (ops->seq_show) |
c2b19daf | 738 | error = seq_open(file, &kernfs_seq_ops); |
f6acf8bb TH |
739 | else |
740 | error = seq_open(file, NULL); | |
13c589d5 TH |
741 | if (error) |
742 | goto err_free; | |
743 | ||
c2b19daf TH |
744 | ((struct seq_file *)file->private_data)->private = of; |
745 | ||
13c589d5 TH |
746 | /* seq_file clears PWRITE unconditionally, restore it if WRITE */ |
747 | if (file->f_mode & FMODE_WRITE) | |
748 | file->f_mode |= FMODE_PWRITE; | |
0ab66088 | 749 | |
85a4ffad | 750 | /* make sure we have open dirent struct */ |
58282d8d | 751 | error = sysfs_get_open_dirent(attr_sd, of); |
85a4ffad | 752 | if (error) |
13c589d5 | 753 | goto err_close; |
85a4ffad | 754 | |
b05f0548 | 755 | /* open succeeded, put active references */ |
e72ceb8c | 756 | sysfs_put_active(attr_sd); |
0ab66088 TH |
757 | return 0; |
758 | ||
13c589d5 | 759 | err_close: |
c2b19daf | 760 | seq_release(inode, file); |
13c589d5 | 761 | err_free: |
58282d8d | 762 | kfree(of); |
13c589d5 | 763 | err_out: |
e72ceb8c | 764 | sysfs_put_active(attr_sd); |
1da177e4 LT |
765 | return error; |
766 | } | |
767 | ||
c6fb4495 | 768 | static int kernfs_file_release(struct inode *inode, struct file *filp) |
1da177e4 | 769 | { |
85a4ffad | 770 | struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; |
13c589d5 | 771 | struct sysfs_open_file *of = sysfs_of(filp); |
1da177e4 | 772 | |
58282d8d | 773 | sysfs_put_open_dirent(sd, of); |
c2b19daf | 774 | seq_release(inode, filp); |
58282d8d | 775 | kfree(of); |
50ab1a72 | 776 | |
1da177e4 LT |
777 | return 0; |
778 | } | |
779 | ||
73d97146 TH |
780 | void sysfs_unmap_bin_file(struct sysfs_dirent *sd) |
781 | { | |
782 | struct sysfs_open_dirent *od; | |
783 | struct sysfs_open_file *of; | |
784 | ||
f6acf8bb | 785 | if (!(sd->s_flags & SYSFS_FLAG_HAS_MMAP)) |
73d97146 TH |
786 | return; |
787 | ||
788 | spin_lock_irq(&sysfs_open_dirent_lock); | |
789 | od = sd->s_attr.open; | |
790 | if (od) | |
791 | atomic_inc(&od->refcnt); | |
792 | spin_unlock_irq(&sysfs_open_dirent_lock); | |
793 | if (!od) | |
794 | return; | |
795 | ||
796 | mutex_lock(&sysfs_open_file_mutex); | |
797 | list_for_each_entry(of, &od->files, list) { | |
798 | struct inode *inode = file_inode(of->file); | |
799 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
800 | } | |
801 | mutex_unlock(&sysfs_open_file_mutex); | |
802 | ||
803 | sysfs_put_open_dirent(sd, NULL); | |
804 | } | |
805 | ||
4508a7a7 N |
806 | /* Sysfs attribute files are pollable. The idea is that you read |
807 | * the content and then you use 'poll' or 'select' to wait for | |
808 | * the content to change. When the content changes (assuming the | |
809 | * manager for the kobject supports notification), poll will | |
810 | * return POLLERR|POLLPRI, and select will return the fd whether | |
811 | * it is waiting for read, write, or exceptions. | |
812 | * Once poll/select indicates that the value has changed, you | |
2424b5dd | 813 | * need to close and re-open the file, or seek to 0 and read again. |
4508a7a7 N |
814 | * Reminder: this only works for attributes which actively support |
815 | * it, and it is not possible to test an attribute from userspace | |
a93720ee | 816 | * to see if it supports poll (Neither 'poll' nor 'select' return |
4508a7a7 N |
817 | * an appropriate error code). When in doubt, set a suitable timeout value. |
818 | */ | |
c6fb4495 | 819 | static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) |
4508a7a7 | 820 | { |
13c589d5 | 821 | struct sysfs_open_file *of = sysfs_of(filp); |
0ab66088 | 822 | struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; |
a4e8b912 | 823 | struct sysfs_open_dirent *od = attr_sd->s_attr.open; |
0ab66088 TH |
824 | |
825 | /* need parent for the kobj, grab both */ | |
e72ceb8c | 826 | if (!sysfs_get_active(attr_sd)) |
0ab66088 | 827 | goto trigger; |
4508a7a7 | 828 | |
a4e8b912 | 829 | poll_wait(filp, &od->poll, wait); |
4508a7a7 | 830 | |
e72ceb8c | 831 | sysfs_put_active(attr_sd); |
0ab66088 | 832 | |
58282d8d | 833 | if (of->event != atomic_read(&od->event)) |
0ab66088 | 834 | goto trigger; |
4508a7a7 | 835 | |
1af3557a | 836 | return DEFAULT_POLLMASK; |
0ab66088 TH |
837 | |
838 | trigger: | |
1af3557a | 839 | return DEFAULT_POLLMASK|POLLERR|POLLPRI; |
4508a7a7 N |
840 | } |
841 | ||
f1282c84 NB |
842 | void sysfs_notify_dirent(struct sysfs_dirent *sd) |
843 | { | |
844 | struct sysfs_open_dirent *od; | |
83db93f4 | 845 | unsigned long flags; |
f1282c84 | 846 | |
83db93f4 | 847 | spin_lock_irqsave(&sysfs_open_dirent_lock, flags); |
f1282c84 | 848 | |
fc60bb83 ND |
849 | if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) { |
850 | od = sd->s_attr.open; | |
851 | if (od) { | |
852 | atomic_inc(&od->event); | |
853 | wake_up_interruptible(&od->poll); | |
854 | } | |
f1282c84 NB |
855 | } |
856 | ||
83db93f4 | 857 | spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); |
f1282c84 NB |
858 | } |
859 | EXPORT_SYMBOL_GPL(sysfs_notify_dirent); | |
860 | ||
8c0e3998 | 861 | void sysfs_notify(struct kobject *k, const char *dir, const char *attr) |
4508a7a7 | 862 | { |
51225039 | 863 | struct sysfs_dirent *sd = k->sd; |
4508a7a7 | 864 | |
51225039 TH |
865 | mutex_lock(&sysfs_mutex); |
866 | ||
867 | if (sd && dir) | |
cfec0bc8 | 868 | sd = sysfs_find_dirent(sd, dir, NULL); |
51225039 | 869 | if (sd && attr) |
cfec0bc8 | 870 | sd = sysfs_find_dirent(sd, attr, NULL); |
f1282c84 NB |
871 | if (sd) |
872 | sysfs_notify_dirent(sd); | |
51225039 TH |
873 | |
874 | mutex_unlock(&sysfs_mutex); | |
4508a7a7 N |
875 | } |
876 | EXPORT_SYMBOL_GPL(sysfs_notify); | |
877 | ||
c6fb4495 | 878 | const struct file_operations kernfs_file_operations = { |
c2b19daf | 879 | .read = kernfs_file_read, |
50b38ca0 | 880 | .write = kernfs_file_write, |
044e3bc3 | 881 | .llseek = generic_file_llseek, |
fdbffaa4 | 882 | .mmap = kernfs_file_mmap, |
c6fb4495 TH |
883 | .open = kernfs_file_open, |
884 | .release = kernfs_file_release, | |
885 | .poll = kernfs_file_poll, | |
f9b9a621 TH |
886 | }; |
887 | ||
f6acf8bb TH |
888 | static const struct kernfs_ops sysfs_file_kfops_empty = { |
889 | }; | |
890 | ||
891 | static const struct kernfs_ops sysfs_file_kfops_ro = { | |
892 | .seq_show = sysfs_kf_seq_show, | |
893 | }; | |
894 | ||
895 | static const struct kernfs_ops sysfs_file_kfops_wo = { | |
896 | .write = sysfs_kf_write, | |
897 | }; | |
898 | ||
899 | static const struct kernfs_ops sysfs_file_kfops_rw = { | |
900 | .seq_show = sysfs_kf_seq_show, | |
901 | .write = sysfs_kf_write, | |
902 | }; | |
903 | ||
904 | static const struct kernfs_ops sysfs_bin_kfops_ro = { | |
905 | .read = sysfs_kf_bin_read, | |
906 | }; | |
907 | ||
908 | static const struct kernfs_ops sysfs_bin_kfops_wo = { | |
909 | .write = sysfs_kf_bin_write, | |
910 | }; | |
911 | ||
912 | static const struct kernfs_ops sysfs_bin_kfops_rw = { | |
913 | .read = sysfs_kf_bin_read, | |
914 | .write = sysfs_kf_bin_write, | |
915 | .mmap = sysfs_kf_bin_mmap, | |
916 | }; | |
917 | ||
58292cbe TH |
918 | int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, |
919 | const struct attribute *attr, int type, | |
920 | umode_t amode, const void *ns) | |
1da177e4 | 921 | { |
0f423895 | 922 | umode_t mode = (amode & S_IALLUGO) | S_IFREG; |
f6acf8bb | 923 | const struct kernfs_ops *ops; |
fb6896da | 924 | struct sysfs_addrm_cxt acxt; |
a26cd722 | 925 | struct sysfs_dirent *sd; |
23dc2799 | 926 | int rc; |
1da177e4 | 927 | |
f6acf8bb TH |
928 | if (type == SYSFS_KOBJ_ATTR) { |
929 | struct kobject *kobj = dir_sd->priv; | |
930 | const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; | |
931 | ||
932 | /* every kobject with an attribute needs a ktype assigned */ | |
933 | if (WARN(!sysfs_ops, KERN_ERR | |
934 | "missing sysfs attribute operations for kobject: %s\n", | |
935 | kobject_name(kobj))) | |
936 | return -EINVAL; | |
937 | ||
938 | if (sysfs_ops->show && sysfs_ops->store) | |
939 | ops = &sysfs_file_kfops_rw; | |
940 | else if (sysfs_ops->show) | |
941 | ops = &sysfs_file_kfops_ro; | |
942 | else if (sysfs_ops->store) | |
943 | ops = &sysfs_file_kfops_wo; | |
944 | else | |
945 | ops = &sysfs_file_kfops_empty; | |
946 | } else { | |
947 | struct bin_attribute *battr = (void *)attr; | |
948 | ||
949 | if ((battr->read && battr->write) || battr->mmap) | |
950 | ops = &sysfs_bin_kfops_rw; | |
951 | else if (battr->read) | |
952 | ops = &sysfs_bin_kfops_ro; | |
953 | else if (battr->write) | |
954 | ops = &sysfs_bin_kfops_wo; | |
955 | else | |
956 | ops = &sysfs_file_kfops_empty; | |
957 | } | |
958 | ||
3007e997 TH |
959 | sd = sysfs_new_dirent(attr->name, mode, type); |
960 | if (!sd) | |
961 | return -ENOMEM; | |
487505c2 | 962 | |
f6acf8bb | 963 | sd->s_attr.ops = ops; |
487505c2 | 964 | sd->s_ns = ns; |
7c6e2d36 | 965 | sd->priv = (void *)attr; |
a2db6842 | 966 | sysfs_dirent_init_lockdep(sd); |
1da177e4 | 967 | |
f6acf8bb TH |
968 | /* |
969 | * sd->s_attr.ops is accesible only while holding active ref. We | |
970 | * need to know whether some ops are implemented outside active | |
971 | * ref. Cache their existence in flags. | |
972 | */ | |
973 | if (ops->seq_show) | |
974 | sd->s_flags |= SYSFS_FLAG_HAS_SEQ_SHOW; | |
975 | if (ops->mmap) | |
976 | sd->s_flags |= SYSFS_FLAG_HAS_MMAP; | |
977 | ||
d69ac5a0 TH |
978 | sysfs_addrm_start(&acxt); |
979 | rc = sysfs_add_one(&acxt, sd, dir_sd); | |
23dc2799 | 980 | sysfs_addrm_finish(&acxt); |
a26cd722 | 981 | |
23dc2799 | 982 | if (rc) |
967e35dc | 983 | sysfs_put(sd); |
3007e997 | 984 | |
23dc2799 | 985 | return rc; |
1da177e4 LT |
986 | } |
987 | ||
988 | ||
0f423895 JB |
989 | int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, |
990 | int type) | |
991 | { | |
58292cbe | 992 | return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL); |
0f423895 JB |
993 | } |
994 | ||
1da177e4 | 995 | /** |
58292cbe TH |
996 | * sysfs_create_file_ns - create an attribute file for an object with custom ns |
997 | * @kobj: object we're creating for | |
998 | * @attr: attribute descriptor | |
999 | * @ns: namespace the new file should belong to | |
1da177e4 | 1000 | */ |
58292cbe TH |
1001 | int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, |
1002 | const void *ns) | |
1da177e4 | 1003 | { |
608e266a | 1004 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 1005 | |
58292cbe TH |
1006 | return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR, |
1007 | attr->mode, ns); | |
1da177e4 LT |
1008 | |
1009 | } | |
58292cbe | 1010 | EXPORT_SYMBOL_GPL(sysfs_create_file_ns); |
1da177e4 | 1011 | |
1c205ae1 AK |
1012 | int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr) |
1013 | { | |
1014 | int err = 0; | |
1015 | int i; | |
1016 | ||
1017 | for (i = 0; ptr[i] && !err; i++) | |
1018 | err = sysfs_create_file(kobj, ptr[i]); | |
1019 | if (err) | |
1020 | while (--i >= 0) | |
1021 | sysfs_remove_file(kobj, ptr[i]); | |
1022 | return err; | |
1023 | } | |
1b866757 | 1024 | EXPORT_SYMBOL_GPL(sysfs_create_files); |
1da177e4 | 1025 | |
dfa87c82 AS |
1026 | /** |
1027 | * sysfs_add_file_to_group - add an attribute file to a pre-existing group. | |
1028 | * @kobj: object we're acting for. | |
1029 | * @attr: attribute descriptor. | |
1030 | * @group: group name. | |
1031 | */ | |
1032 | int sysfs_add_file_to_group(struct kobject *kobj, | |
1033 | const struct attribute *attr, const char *group) | |
1034 | { | |
608e266a | 1035 | struct sysfs_dirent *dir_sd; |
dfa87c82 AS |
1036 | int error; |
1037 | ||
11f24fbd | 1038 | if (group) |
388975cc | 1039 | dir_sd = sysfs_get_dirent(kobj->sd, group); |
11f24fbd JB |
1040 | else |
1041 | dir_sd = sysfs_get(kobj->sd); | |
1042 | ||
608e266a TH |
1043 | if (!dir_sd) |
1044 | return -ENOENT; | |
1045 | ||
1046 | error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR); | |
1047 | sysfs_put(dir_sd); | |
1048 | ||
dfa87c82 AS |
1049 | return error; |
1050 | } | |
1051 | EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); | |
1052 | ||
31e5abe9 KS |
1053 | /** |
1054 | * sysfs_chmod_file - update the modified mode value on an object attribute. | |
1055 | * @kobj: object we're acting for. | |
1056 | * @attr: attribute descriptor. | |
1057 | * @mode: file permissions. | |
1058 | * | |
1059 | */ | |
49c19400 | 1060 | int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, |
48176a97 | 1061 | umode_t mode) |
31e5abe9 | 1062 | { |
06fc0d66 | 1063 | struct sysfs_dirent *sd; |
bc062b1b | 1064 | struct iattr newattrs; |
51225039 TH |
1065 | int rc; |
1066 | ||
5d60418e | 1067 | sd = sysfs_get_dirent(kobj->sd, attr->name); |
06fc0d66 | 1068 | if (!sd) |
5d60418e | 1069 | return -ENOENT; |
f88123ea | 1070 | |
06fc0d66 | 1071 | newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); |
4c6974f5 | 1072 | newattrs.ia_valid = ATTR_MODE; |
f88123ea | 1073 | |
5d60418e TH |
1074 | rc = kernfs_setattr(sd, &newattrs); |
1075 | ||
1076 | sysfs_put(sd); | |
51225039 | 1077 | return rc; |
31e5abe9 KS |
1078 | } |
1079 | EXPORT_SYMBOL_GPL(sysfs_chmod_file); | |
1080 | ||
1da177e4 | 1081 | /** |
58292cbe TH |
1082 | * sysfs_remove_file_ns - remove an object attribute with a custom ns tag |
1083 | * @kobj: object we're acting for | |
1084 | * @attr: attribute descriptor | |
1085 | * @ns: namespace tag of the file to remove | |
1da177e4 | 1086 | * |
58292cbe | 1087 | * Hash the attribute name and namespace tag and kill the victim. |
1da177e4 | 1088 | */ |
58292cbe TH |
1089 | void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, |
1090 | const void *ns) | |
1da177e4 | 1091 | { |
58292cbe | 1092 | struct sysfs_dirent *dir_sd = kobj->sd; |
487505c2 | 1093 | |
879f40d1 | 1094 | kernfs_remove_by_name_ns(dir_sd, attr->name, ns); |
1da177e4 | 1095 | } |
58292cbe | 1096 | EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); |
1da177e4 | 1097 | |
1b18dc2b | 1098 | void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr) |
1c205ae1 AK |
1099 | { |
1100 | int i; | |
1101 | for (i = 0; ptr[i]; i++) | |
1102 | sysfs_remove_file(kobj, ptr[i]); | |
1103 | } | |
1b866757 | 1104 | EXPORT_SYMBOL_GPL(sysfs_remove_files); |
1da177e4 | 1105 | |
dfa87c82 AS |
1106 | /** |
1107 | * sysfs_remove_file_from_group - remove an attribute file from a group. | |
1108 | * @kobj: object we're acting for. | |
1109 | * @attr: attribute descriptor. | |
1110 | * @group: group name. | |
1111 | */ | |
1112 | void sysfs_remove_file_from_group(struct kobject *kobj, | |
1113 | const struct attribute *attr, const char *group) | |
1114 | { | |
608e266a | 1115 | struct sysfs_dirent *dir_sd; |
dfa87c82 | 1116 | |
11f24fbd | 1117 | if (group) |
388975cc | 1118 | dir_sd = sysfs_get_dirent(kobj->sd, group); |
11f24fbd JB |
1119 | else |
1120 | dir_sd = sysfs_get(kobj->sd); | |
608e266a | 1121 | if (dir_sd) { |
879f40d1 | 1122 | kernfs_remove_by_name(dir_sd, attr->name); |
608e266a | 1123 | sysfs_put(dir_sd); |
dfa87c82 AS |
1124 | } |
1125 | } | |
1126 | EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); | |
1127 | ||
3124eb16 TH |
1128 | /** |
1129 | * sysfs_create_bin_file - create binary file for object. | |
1130 | * @kobj: object. | |
1131 | * @attr: attribute descriptor. | |
1132 | */ | |
1133 | int sysfs_create_bin_file(struct kobject *kobj, | |
1134 | const struct bin_attribute *attr) | |
1135 | { | |
1136 | BUG_ON(!kobj || !kobj->sd || !attr); | |
1137 | ||
1138 | return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); | |
1139 | } | |
1140 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
1141 | ||
1142 | /** | |
1143 | * sysfs_remove_bin_file - remove binary file for object. | |
1144 | * @kobj: object. | |
1145 | * @attr: attribute descriptor. | |
1146 | */ | |
1147 | void sysfs_remove_bin_file(struct kobject *kobj, | |
1148 | const struct bin_attribute *attr) | |
1149 | { | |
879f40d1 | 1150 | kernfs_remove_by_name(kobj->sd, attr->attr.name); |
3124eb16 TH |
1151 | } |
1152 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); | |
1153 | ||
d9a9cdfb | 1154 | struct sysfs_schedule_callback_struct { |
66942064 AC |
1155 | struct list_head workq_list; |
1156 | struct kobject *kobj; | |
d9a9cdfb AS |
1157 | void (*func)(void *); |
1158 | void *data; | |
523ded71 | 1159 | struct module *owner; |
d9a9cdfb AS |
1160 | struct work_struct work; |
1161 | }; | |
1162 | ||
d110271e | 1163 | static struct workqueue_struct *sysfs_workqueue; |
66942064 AC |
1164 | static DEFINE_MUTEX(sysfs_workq_mutex); |
1165 | static LIST_HEAD(sysfs_workq); | |
d9a9cdfb AS |
1166 | static void sysfs_schedule_callback_work(struct work_struct *work) |
1167 | { | |
1168 | struct sysfs_schedule_callback_struct *ss = container_of(work, | |
1169 | struct sysfs_schedule_callback_struct, work); | |
1170 | ||
1171 | (ss->func)(ss->data); | |
1172 | kobject_put(ss->kobj); | |
523ded71 | 1173 | module_put(ss->owner); |
66942064 AC |
1174 | mutex_lock(&sysfs_workq_mutex); |
1175 | list_del(&ss->workq_list); | |
1176 | mutex_unlock(&sysfs_workq_mutex); | |
d9a9cdfb AS |
1177 | kfree(ss); |
1178 | } | |
1179 | ||
1180 | /** | |
1181 | * sysfs_schedule_callback - helper to schedule a callback for a kobject | |
1182 | * @kobj: object we're acting for. | |
1183 | * @func: callback function to invoke later. | |
1184 | * @data: argument to pass to @func. | |
523ded71 | 1185 | * @owner: module owning the callback code |
d9a9cdfb AS |
1186 | * |
1187 | * sysfs attribute methods must not unregister themselves or their parent | |
1188 | * kobject (which would amount to the same thing). Attempts to do so will | |
1189 | * deadlock, since unregistration is mutually exclusive with driver | |
1190 | * callbacks. | |
1191 | * | |
1192 | * Instead methods can call this routine, which will attempt to allocate | |
1193 | * and schedule a workqueue request to call back @func with @data as its | |
1194 | * argument in the workqueue's process context. @kobj will be pinned | |
1195 | * until @func returns. | |
1196 | * | |
1197 | * Returns 0 if the request was submitted, -ENOMEM if storage could not | |
66942064 AC |
1198 | * be allocated, -ENODEV if a reference to @owner isn't available, |
1199 | * -EAGAIN if a callback has already been scheduled for @kobj. | |
d9a9cdfb AS |
1200 | */ |
1201 | int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), | |
523ded71 | 1202 | void *data, struct module *owner) |
d9a9cdfb | 1203 | { |
66942064 | 1204 | struct sysfs_schedule_callback_struct *ss, *tmp; |
d9a9cdfb | 1205 | |
523ded71 AS |
1206 | if (!try_module_get(owner)) |
1207 | return -ENODEV; | |
66942064 AC |
1208 | |
1209 | mutex_lock(&sysfs_workq_mutex); | |
1210 | list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list) | |
1211 | if (ss->kobj == kobj) { | |
d110271e | 1212 | module_put(owner); |
66942064 AC |
1213 | mutex_unlock(&sysfs_workq_mutex); |
1214 | return -EAGAIN; | |
1215 | } | |
1216 | mutex_unlock(&sysfs_workq_mutex); | |
1217 | ||
d110271e | 1218 | if (sysfs_workqueue == NULL) { |
086a377e | 1219 | sysfs_workqueue = create_singlethread_workqueue("sysfsd"); |
d110271e AC |
1220 | if (sysfs_workqueue == NULL) { |
1221 | module_put(owner); | |
1222 | return -ENOMEM; | |
1223 | } | |
1224 | } | |
1225 | ||
d9a9cdfb | 1226 | ss = kmalloc(sizeof(*ss), GFP_KERNEL); |
523ded71 AS |
1227 | if (!ss) { |
1228 | module_put(owner); | |
d9a9cdfb | 1229 | return -ENOMEM; |
523ded71 | 1230 | } |
d9a9cdfb AS |
1231 | kobject_get(kobj); |
1232 | ss->kobj = kobj; | |
1233 | ss->func = func; | |
1234 | ss->data = data; | |
523ded71 | 1235 | ss->owner = owner; |
d9a9cdfb | 1236 | INIT_WORK(&ss->work, sysfs_schedule_callback_work); |
66942064 AC |
1237 | INIT_LIST_HEAD(&ss->workq_list); |
1238 | mutex_lock(&sysfs_workq_mutex); | |
1239 | list_add_tail(&ss->workq_list, &sysfs_workq); | |
1240 | mutex_unlock(&sysfs_workq_mutex); | |
d110271e | 1241 | queue_work(sysfs_workqueue, &ss->work); |
d9a9cdfb AS |
1242 | return 0; |
1243 | } | |
1244 | EXPORT_SYMBOL_GPL(sysfs_schedule_callback); |