]>
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 | ||
13c589d5 TH |
50 | static struct sysfs_open_file *sysfs_of(struct file *file) |
51 | { | |
52 | return ((struct seq_file *)file->private_data)->private; | |
53 | } | |
54 | ||
f6acf8bb TH |
55 | /* |
56 | * Determine the kernfs_ops for the given sysfs_dirent. This function must | |
57 | * be called while holding an active reference. | |
58 | */ | |
59 | static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) | |
60 | { | |
517e64f5 | 61 | if (sd->s_flags & SYSFS_FLAG_LOCKDEP) |
f6acf8bb TH |
62 | lockdep_assert_held(sd); |
63 | return sd->s_attr.ops; | |
64 | } | |
65 | ||
375b611e TH |
66 | /* |
67 | * Determine ktype->sysfs_ops for the given sysfs_dirent. This function | |
68 | * must be called while holding an active reference. | |
69 | */ | |
70 | static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) | |
71 | { | |
7c6e2d36 | 72 | struct kobject *kobj = sd->s_parent->priv; |
375b611e | 73 | |
517e64f5 | 74 | if (sd->s_flags & SYSFS_FLAG_LOCKDEP) |
785a162d | 75 | lockdep_assert_held(sd); |
375b611e TH |
76 | return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; |
77 | } | |
78 | ||
13c589d5 TH |
79 | /* |
80 | * Reads on sysfs are handled through seq_file, which takes care of hairy | |
81 | * details like buffering and seeking. The following function pipes | |
82 | * sysfs_ops->show() result through seq_file. | |
1da177e4 | 83 | */ |
c2b19daf | 84 | static int sysfs_kf_seq_show(struct seq_file *sf, void *v) |
1da177e4 | 85 | { |
13c589d5 | 86 | struct sysfs_open_file *of = sf->private; |
7c6e2d36 | 87 | struct kobject *kobj = of->sd->s_parent->priv; |
c2b19daf | 88 | const struct sysfs_ops *ops = sysfs_file_ops(of->sd); |
1da177e4 | 89 | ssize_t count; |
c2b19daf | 90 | char *buf; |
1da177e4 | 91 | |
13c589d5 TH |
92 | /* acquire buffer and ensure that it's >= PAGE_SIZE */ |
93 | count = seq_get_buf(sf, &buf); | |
94 | if (count < PAGE_SIZE) { | |
95 | seq_commit(sf, -1); | |
96 | return 0; | |
97 | } | |
1da177e4 | 98 | |
13c589d5 | 99 | /* |
c2b19daf TH |
100 | * Invoke show(). Control may reach here via seq file lseek even |
101 | * if @ops->show() isn't implemented. | |
13c589d5 | 102 | */ |
c2b19daf | 103 | if (ops->show) { |
7c6e2d36 | 104 | count = ops->show(kobj, of->sd->priv, buf); |
c2b19daf TH |
105 | if (count < 0) |
106 | return count; | |
107 | } | |
0ab66088 | 108 | |
8118a859 MX |
109 | /* |
110 | * The code works fine with PAGE_SIZE return but it's likely to | |
111 | * indicate truncated result or overflow in normal use cases. | |
112 | */ | |
815d2d50 AM |
113 | if (count >= (ssize_t)PAGE_SIZE) { |
114 | print_symbol("fill_read_buffer: %s returned bad count\n", | |
115 | (unsigned long)ops->show); | |
116 | /* Try to struggle along */ | |
117 | count = PAGE_SIZE - 1; | |
118 | } | |
13c589d5 TH |
119 | seq_commit(sf, count); |
120 | return 0; | |
1da177e4 LT |
121 | } |
122 | ||
c2b19daf TH |
123 | static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, |
124 | size_t count, loff_t pos) | |
2f0c6b75 | 125 | { |
7c6e2d36 TH |
126 | struct bin_attribute *battr = of->sd->priv; |
127 | struct kobject *kobj = of->sd->s_parent->priv; | |
c2b19daf | 128 | loff_t size = file_inode(of->file)->i_size; |
2f0c6b75 | 129 | |
c2b19daf | 130 | if (!count) |
2f0c6b75 TH |
131 | return 0; |
132 | ||
133 | if (size) { | |
c2b19daf | 134 | if (pos > size) |
2f0c6b75 | 135 | return 0; |
c2b19daf TH |
136 | if (pos + count > size) |
137 | count = size - pos; | |
2f0c6b75 TH |
138 | } |
139 | ||
c2b19daf TH |
140 | if (!battr->read) |
141 | return -EIO; | |
142 | ||
143 | return battr->read(of->file, kobj, battr, buf, pos, count); | |
144 | } | |
145 | ||
146 | static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) | |
147 | { | |
148 | struct sysfs_open_file *of = sf->private; | |
d19b9846 | 149 | const struct kernfs_ops *ops; |
c2b19daf TH |
150 | |
151 | /* | |
152 | * @of->mutex nests outside active ref and is just to ensure that | |
153 | * the ops aren't called concurrently for the same open file. | |
154 | */ | |
155 | mutex_lock(&of->mutex); | |
156 | if (!sysfs_get_active(of->sd)) | |
157 | return ERR_PTR(-ENODEV); | |
158 | ||
d19b9846 TH |
159 | ops = kernfs_ops(of->sd); |
160 | if (ops->seq_start) { | |
161 | return ops->seq_start(sf, ppos); | |
162 | } else { | |
163 | /* | |
164 | * The same behavior and code as single_open(). Returns | |
165 | * !NULL if pos is at the beginning; otherwise, NULL. | |
166 | */ | |
167 | return NULL + !*ppos; | |
168 | } | |
c2b19daf TH |
169 | } |
170 | ||
171 | static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) | |
172 | { | |
d19b9846 TH |
173 | struct sysfs_open_file *of = sf->private; |
174 | const struct kernfs_ops *ops = kernfs_ops(of->sd); | |
175 | ||
176 | if (ops->seq_next) { | |
177 | return ops->seq_next(sf, v, ppos); | |
178 | } else { | |
179 | /* | |
180 | * The same behavior and code as single_open(), always | |
181 | * terminate after the initial read. | |
182 | */ | |
183 | ++*ppos; | |
184 | return NULL; | |
185 | } | |
c2b19daf TH |
186 | } |
187 | ||
188 | static void kernfs_seq_stop(struct seq_file *sf, void *v) | |
189 | { | |
190 | struct sysfs_open_file *of = sf->private; | |
d19b9846 TH |
191 | const struct kernfs_ops *ops = kernfs_ops(of->sd); |
192 | ||
193 | if (ops->seq_stop) | |
194 | ops->seq_stop(sf, v); | |
c2b19daf TH |
195 | |
196 | sysfs_put_active(of->sd); | |
197 | mutex_unlock(&of->mutex); | |
198 | } | |
199 | ||
200 | static int kernfs_seq_show(struct seq_file *sf, void *v) | |
201 | { | |
202 | struct sysfs_open_file *of = sf->private; | |
203 | ||
204 | of->event = atomic_read(&of->sd->s_attr.open->event); | |
205 | ||
f6acf8bb | 206 | return of->sd->s_attr.ops->seq_show(sf, v); |
c2b19daf TH |
207 | } |
208 | ||
209 | static const struct seq_operations kernfs_seq_ops = { | |
210 | .start = kernfs_seq_start, | |
211 | .next = kernfs_seq_next, | |
212 | .stop = kernfs_seq_stop, | |
213 | .show = kernfs_seq_show, | |
214 | }; | |
215 | ||
216 | /* | |
217 | * As reading a bin file can have side-effects, the exact offset and bytes | |
218 | * specified in read(2) call should be passed to the read callback making | |
219 | * it difficult to use seq_file. Implement simplistic custom buffering for | |
220 | * bin files. | |
221 | */ | |
222 | static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, | |
223 | char __user *user_buf, size_t count, | |
224 | loff_t *ppos) | |
225 | { | |
226 | ssize_t len = min_t(size_t, count, PAGE_SIZE); | |
f6acf8bb | 227 | const struct kernfs_ops *ops; |
c2b19daf TH |
228 | char *buf; |
229 | ||
230 | buf = kmalloc(len, GFP_KERNEL); | |
2f0c6b75 TH |
231 | if (!buf) |
232 | return -ENOMEM; | |
233 | ||
c2b19daf TH |
234 | /* |
235 | * @of->mutex nests outside active ref and is just to ensure that | |
236 | * the ops aren't called concurrently for the same open file. | |
237 | */ | |
2f0c6b75 TH |
238 | mutex_lock(&of->mutex); |
239 | if (!sysfs_get_active(of->sd)) { | |
c2b19daf | 240 | len = -ENODEV; |
2f0c6b75 TH |
241 | mutex_unlock(&of->mutex); |
242 | goto out_free; | |
243 | } | |
244 | ||
f6acf8bb TH |
245 | ops = kernfs_ops(of->sd); |
246 | if (ops->read) | |
247 | len = ops->read(of, buf, len, *ppos); | |
248 | else | |
249 | len = -EINVAL; | |
2f0c6b75 TH |
250 | |
251 | sysfs_put_active(of->sd); | |
252 | mutex_unlock(&of->mutex); | |
253 | ||
c2b19daf | 254 | if (len < 0) |
2f0c6b75 TH |
255 | goto out_free; |
256 | ||
c2b19daf TH |
257 | if (copy_to_user(user_buf, buf, len)) { |
258 | len = -EFAULT; | |
2f0c6b75 TH |
259 | goto out_free; |
260 | } | |
261 | ||
c2b19daf | 262 | *ppos += len; |
2f0c6b75 TH |
263 | |
264 | out_free: | |
265 | kfree(buf); | |
c2b19daf TH |
266 | return len; |
267 | } | |
268 | ||
269 | /** | |
270 | * kernfs_file_read - kernfs vfs read callback | |
271 | * @file: file pointer | |
272 | * @user_buf: data to write | |
273 | * @count: number of bytes | |
274 | * @ppos: starting offset | |
275 | */ | |
276 | static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, | |
277 | size_t count, loff_t *ppos) | |
278 | { | |
279 | struct sysfs_open_file *of = sysfs_of(file); | |
280 | ||
f6acf8bb | 281 | if (of->sd->s_flags & SYSFS_FLAG_HAS_SEQ_SHOW) |
c2b19daf | 282 | return seq_read(file, user_buf, count, ppos); |
f6acf8bb TH |
283 | else |
284 | return kernfs_file_direct_read(of, user_buf, count, ppos); | |
2f0c6b75 TH |
285 | } |
286 | ||
50b38ca0 TH |
287 | /* kernfs write callback for regular sysfs files */ |
288 | static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, | |
289 | size_t count, loff_t pos) | |
1da177e4 | 290 | { |
50b38ca0 | 291 | const struct sysfs_ops *ops = sysfs_file_ops(of->sd); |
7c6e2d36 | 292 | struct kobject *kobj = of->sd->s_parent->priv; |
0ab66088 | 293 | |
50b38ca0 TH |
294 | if (!count) |
295 | return 0; | |
0ab66088 | 296 | |
50b38ca0 TH |
297 | return ops->store(kobj, of->sd->priv, buf, count); |
298 | } | |
f9b9a621 | 299 | |
50b38ca0 TH |
300 | /* kernfs write callback for bin sysfs files */ |
301 | static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, | |
302 | size_t count, loff_t pos) | |
303 | { | |
304 | struct bin_attribute *battr = of->sd->priv; | |
305 | struct kobject *kobj = of->sd->s_parent->priv; | |
306 | loff_t size = file_inode(of->file)->i_size; | |
f9b9a621 | 307 | |
50b38ca0 TH |
308 | if (size) { |
309 | if (size <= pos) | |
310 | return 0; | |
311 | count = min_t(ssize_t, count, size - pos); | |
f9b9a621 | 312 | } |
50b38ca0 TH |
313 | if (!count) |
314 | return 0; | |
0ab66088 | 315 | |
50b38ca0 TH |
316 | if (!battr->write) |
317 | return -EIO; | |
1da177e4 | 318 | |
50b38ca0 | 319 | return battr->write(of->file, kobj, battr, buf, pos, count); |
1da177e4 LT |
320 | } |
321 | ||
1da177e4 | 322 | /** |
50b38ca0 | 323 | * kernfs_file_write - kernfs vfs write callback |
8ef445f0 TH |
324 | * @file: file pointer |
325 | * @user_buf: data to write | |
326 | * @count: number of bytes | |
327 | * @ppos: starting offset | |
328 | * | |
50b38ca0 TH |
329 | * Copy data in from userland and pass it to the matching kernfs write |
330 | * operation. | |
1da177e4 | 331 | * |
8ef445f0 TH |
332 | * There is no easy way for us to know if userspace is only doing a partial |
333 | * write, so we don't support them. We expect the entire buffer to come on | |
334 | * the first write. Hint: if you're writing a value, first read the file, | |
335 | * modify only the the value you're changing, then write entire buffer | |
336 | * back. | |
1da177e4 | 337 | */ |
50b38ca0 TH |
338 | static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, |
339 | size_t count, loff_t *ppos) | |
1da177e4 | 340 | { |
13c589d5 | 341 | struct sysfs_open_file *of = sysfs_of(file); |
f9b9a621 | 342 | ssize_t len = min_t(size_t, count, PAGE_SIZE); |
f6acf8bb | 343 | const struct kernfs_ops *ops; |
8ef445f0 | 344 | char *buf; |
1da177e4 | 345 | |
8ef445f0 TH |
346 | buf = kmalloc(len + 1, GFP_KERNEL); |
347 | if (!buf) | |
348 | return -ENOMEM; | |
349 | ||
350 | if (copy_from_user(buf, user_buf, len)) { | |
351 | len = -EFAULT; | |
352 | goto out_free; | |
353 | } | |
354 | buf[len] = '\0'; /* guarantee string termination */ | |
355 | ||
50b38ca0 TH |
356 | /* |
357 | * @of->mutex nests outside active ref and is just to ensure that | |
358 | * the ops aren't called concurrently for the same open file. | |
359 | */ | |
360 | mutex_lock(&of->mutex); | |
361 | if (!sysfs_get_active(of->sd)) { | |
362 | mutex_unlock(&of->mutex); | |
363 | len = -ENODEV; | |
364 | goto out_free; | |
365 | } | |
366 | ||
f6acf8bb TH |
367 | ops = kernfs_ops(of->sd); |
368 | if (ops->write) | |
369 | len = ops->write(of, buf, len, *ppos); | |
50b38ca0 | 370 | else |
f6acf8bb | 371 | len = -EINVAL; |
50b38ca0 TH |
372 | |
373 | sysfs_put_active(of->sd); | |
374 | mutex_unlock(&of->mutex); | |
375 | ||
1da177e4 LT |
376 | if (len > 0) |
377 | *ppos += len; | |
8ef445f0 TH |
378 | out_free: |
379 | kfree(buf); | |
1da177e4 LT |
380 | return len; |
381 | } | |
382 | ||
fdbffaa4 TH |
383 | static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, |
384 | struct vm_area_struct *vma) | |
385 | { | |
386 | struct bin_attribute *battr = of->sd->priv; | |
387 | struct kobject *kobj = of->sd->s_parent->priv; | |
388 | ||
389 | if (!battr->mmap) | |
390 | return -ENODEV; | |
391 | ||
392 | return battr->mmap(of->file, kobj, battr, vma); | |
393 | } | |
394 | ||
395 | static void kernfs_vma_open(struct vm_area_struct *vma) | |
73d97146 TH |
396 | { |
397 | struct file *file = vma->vm_file; | |
398 | struct sysfs_open_file *of = sysfs_of(file); | |
399 | ||
400 | if (!of->vm_ops) | |
401 | return; | |
402 | ||
403 | if (!sysfs_get_active(of->sd)) | |
404 | return; | |
405 | ||
406 | if (of->vm_ops->open) | |
407 | of->vm_ops->open(vma); | |
408 | ||
409 | sysfs_put_active(of->sd); | |
410 | } | |
411 | ||
fdbffaa4 | 412 | static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
73d97146 TH |
413 | { |
414 | struct file *file = vma->vm_file; | |
415 | struct sysfs_open_file *of = sysfs_of(file); | |
416 | int ret; | |
417 | ||
418 | if (!of->vm_ops) | |
419 | return VM_FAULT_SIGBUS; | |
420 | ||
421 | if (!sysfs_get_active(of->sd)) | |
422 | return VM_FAULT_SIGBUS; | |
423 | ||
424 | ret = VM_FAULT_SIGBUS; | |
425 | if (of->vm_ops->fault) | |
426 | ret = of->vm_ops->fault(vma, vmf); | |
427 | ||
428 | sysfs_put_active(of->sd); | |
429 | return ret; | |
430 | } | |
431 | ||
fdbffaa4 TH |
432 | static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma, |
433 | struct vm_fault *vmf) | |
73d97146 TH |
434 | { |
435 | struct file *file = vma->vm_file; | |
436 | struct sysfs_open_file *of = sysfs_of(file); | |
437 | int ret; | |
438 | ||
439 | if (!of->vm_ops) | |
440 | return VM_FAULT_SIGBUS; | |
441 | ||
442 | if (!sysfs_get_active(of->sd)) | |
443 | return VM_FAULT_SIGBUS; | |
444 | ||
445 | ret = 0; | |
446 | if (of->vm_ops->page_mkwrite) | |
447 | ret = of->vm_ops->page_mkwrite(vma, vmf); | |
448 | else | |
449 | file_update_time(file); | |
450 | ||
451 | sysfs_put_active(of->sd); | |
452 | return ret; | |
453 | } | |
454 | ||
fdbffaa4 TH |
455 | static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr, |
456 | void *buf, int len, int write) | |
73d97146 TH |
457 | { |
458 | struct file *file = vma->vm_file; | |
459 | struct sysfs_open_file *of = sysfs_of(file); | |
460 | int ret; | |
461 | ||
462 | if (!of->vm_ops) | |
463 | return -EINVAL; | |
464 | ||
465 | if (!sysfs_get_active(of->sd)) | |
466 | return -EINVAL; | |
467 | ||
468 | ret = -EINVAL; | |
469 | if (of->vm_ops->access) | |
470 | ret = of->vm_ops->access(vma, addr, buf, len, write); | |
471 | ||
472 | sysfs_put_active(of->sd); | |
473 | return ret; | |
474 | } | |
475 | ||
476 | #ifdef CONFIG_NUMA | |
fdbffaa4 TH |
477 | static int kernfs_vma_set_policy(struct vm_area_struct *vma, |
478 | struct mempolicy *new) | |
73d97146 TH |
479 | { |
480 | struct file *file = vma->vm_file; | |
481 | struct sysfs_open_file *of = sysfs_of(file); | |
482 | int ret; | |
483 | ||
484 | if (!of->vm_ops) | |
485 | return 0; | |
486 | ||
487 | if (!sysfs_get_active(of->sd)) | |
488 | return -EINVAL; | |
489 | ||
490 | ret = 0; | |
491 | if (of->vm_ops->set_policy) | |
492 | ret = of->vm_ops->set_policy(vma, new); | |
493 | ||
494 | sysfs_put_active(of->sd); | |
495 | return ret; | |
496 | } | |
497 | ||
fdbffaa4 TH |
498 | static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, |
499 | unsigned long addr) | |
73d97146 TH |
500 | { |
501 | struct file *file = vma->vm_file; | |
502 | struct sysfs_open_file *of = sysfs_of(file); | |
503 | struct mempolicy *pol; | |
504 | ||
505 | if (!of->vm_ops) | |
506 | return vma->vm_policy; | |
507 | ||
508 | if (!sysfs_get_active(of->sd)) | |
509 | return vma->vm_policy; | |
510 | ||
511 | pol = vma->vm_policy; | |
512 | if (of->vm_ops->get_policy) | |
513 | pol = of->vm_ops->get_policy(vma, addr); | |
514 | ||
515 | sysfs_put_active(of->sd); | |
516 | return pol; | |
517 | } | |
518 | ||
fdbffaa4 TH |
519 | static int kernfs_vma_migrate(struct vm_area_struct *vma, |
520 | const nodemask_t *from, const nodemask_t *to, | |
521 | unsigned long flags) | |
73d97146 TH |
522 | { |
523 | struct file *file = vma->vm_file; | |
524 | struct sysfs_open_file *of = sysfs_of(file); | |
525 | int ret; | |
526 | ||
527 | if (!of->vm_ops) | |
528 | return 0; | |
529 | ||
530 | if (!sysfs_get_active(of->sd)) | |
531 | return 0; | |
532 | ||
533 | ret = 0; | |
534 | if (of->vm_ops->migrate) | |
535 | ret = of->vm_ops->migrate(vma, from, to, flags); | |
536 | ||
537 | sysfs_put_active(of->sd); | |
538 | return ret; | |
539 | } | |
540 | #endif | |
541 | ||
fdbffaa4 TH |
542 | static const struct vm_operations_struct kernfs_vm_ops = { |
543 | .open = kernfs_vma_open, | |
544 | .fault = kernfs_vma_fault, | |
545 | .page_mkwrite = kernfs_vma_page_mkwrite, | |
546 | .access = kernfs_vma_access, | |
73d97146 | 547 | #ifdef CONFIG_NUMA |
fdbffaa4 TH |
548 | .set_policy = kernfs_vma_set_policy, |
549 | .get_policy = kernfs_vma_get_policy, | |
550 | .migrate = kernfs_vma_migrate, | |
73d97146 TH |
551 | #endif |
552 | }; | |
553 | ||
fdbffaa4 | 554 | static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
73d97146 TH |
555 | { |
556 | struct sysfs_open_file *of = sysfs_of(file); | |
f6acf8bb | 557 | const struct kernfs_ops *ops; |
73d97146 TH |
558 | int rc; |
559 | ||
560 | mutex_lock(&of->mutex); | |
561 | ||
73d97146 TH |
562 | rc = -ENODEV; |
563 | if (!sysfs_get_active(of->sd)) | |
564 | goto out_unlock; | |
565 | ||
f6acf8bb TH |
566 | ops = kernfs_ops(of->sd); |
567 | if (ops->mmap) | |
568 | rc = ops->mmap(of, vma); | |
73d97146 TH |
569 | if (rc) |
570 | goto out_put; | |
571 | ||
572 | /* | |
573 | * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() | |
574 | * to satisfy versions of X which crash if the mmap fails: that | |
575 | * substitutes a new vm_file, and we don't then want bin_vm_ops. | |
576 | */ | |
577 | if (vma->vm_file != file) | |
578 | goto out_put; | |
579 | ||
580 | rc = -EINVAL; | |
581 | if (of->mmapped && of->vm_ops != vma->vm_ops) | |
582 | goto out_put; | |
583 | ||
584 | /* | |
585 | * It is not possible to successfully wrap close. | |
586 | * So error if someone is trying to use close. | |
587 | */ | |
588 | rc = -EINVAL; | |
589 | if (vma->vm_ops && vma->vm_ops->close) | |
590 | goto out_put; | |
591 | ||
592 | rc = 0; | |
593 | of->mmapped = 1; | |
594 | of->vm_ops = vma->vm_ops; | |
fdbffaa4 | 595 | vma->vm_ops = &kernfs_vm_ops; |
73d97146 TH |
596 | out_put: |
597 | sysfs_put_active(of->sd); | |
598 | out_unlock: | |
599 | mutex_unlock(&of->mutex); | |
600 | ||
601 | return rc; | |
602 | } | |
603 | ||
85a4ffad TH |
604 | /** |
605 | * sysfs_get_open_dirent - get or create sysfs_open_dirent | |
606 | * @sd: target sysfs_dirent | |
58282d8d | 607 | * @of: sysfs_open_file for this instance of open |
85a4ffad TH |
608 | * |
609 | * If @sd->s_attr.open exists, increment its reference count; | |
58282d8d | 610 | * otherwise, create one. @of is chained to the files list. |
85a4ffad TH |
611 | * |
612 | * LOCKING: | |
613 | * Kernel thread context (may sleep). | |
614 | * | |
615 | * RETURNS: | |
616 | * 0 on success, -errno on failure. | |
617 | */ | |
618 | static int sysfs_get_open_dirent(struct sysfs_dirent *sd, | |
58282d8d | 619 | struct sysfs_open_file *of) |
85a4ffad TH |
620 | { |
621 | struct sysfs_open_dirent *od, *new_od = NULL; | |
622 | ||
623 | retry: | |
c75ec764 | 624 | mutex_lock(&sysfs_open_file_mutex); |
83db93f4 | 625 | spin_lock_irq(&sysfs_open_dirent_lock); |
85a4ffad TH |
626 | |
627 | if (!sd->s_attr.open && new_od) { | |
628 | sd->s_attr.open = new_od; | |
629 | new_od = NULL; | |
630 | } | |
631 | ||
632 | od = sd->s_attr.open; | |
633 | if (od) { | |
634 | atomic_inc(&od->refcnt); | |
58282d8d | 635 | list_add_tail(&of->list, &od->files); |
85a4ffad TH |
636 | } |
637 | ||
83db93f4 | 638 | spin_unlock_irq(&sysfs_open_dirent_lock); |
c75ec764 | 639 | mutex_unlock(&sysfs_open_file_mutex); |
85a4ffad TH |
640 | |
641 | if (od) { | |
642 | kfree(new_od); | |
643 | return 0; | |
644 | } | |
645 | ||
646 | /* not there, initialize a new one and retry */ | |
647 | new_od = kmalloc(sizeof(*new_od), GFP_KERNEL); | |
648 | if (!new_od) | |
649 | return -ENOMEM; | |
650 | ||
651 | atomic_set(&new_od->refcnt, 0); | |
a4e8b912 TH |
652 | atomic_set(&new_od->event, 1); |
653 | init_waitqueue_head(&new_od->poll); | |
58282d8d | 654 | INIT_LIST_HEAD(&new_od->files); |
85a4ffad TH |
655 | goto retry; |
656 | } | |
657 | ||
658 | /** | |
659 | * sysfs_put_open_dirent - put sysfs_open_dirent | |
660 | * @sd: target sysfs_dirent | |
58282d8d | 661 | * @of: associated sysfs_open_file |
85a4ffad | 662 | * |
58282d8d TH |
663 | * Put @sd->s_attr.open and unlink @of from the files list. If |
664 | * reference count reaches zero, disassociate and free it. | |
85a4ffad TH |
665 | * |
666 | * LOCKING: | |
667 | * None. | |
668 | */ | |
669 | static void sysfs_put_open_dirent(struct sysfs_dirent *sd, | |
58282d8d | 670 | struct sysfs_open_file *of) |
85a4ffad TH |
671 | { |
672 | struct sysfs_open_dirent *od = sd->s_attr.open; | |
83db93f4 | 673 | unsigned long flags; |
85a4ffad | 674 | |
c75ec764 | 675 | mutex_lock(&sysfs_open_file_mutex); |
83db93f4 | 676 | spin_lock_irqsave(&sysfs_open_dirent_lock, flags); |
85a4ffad | 677 | |
73d97146 TH |
678 | if (of) |
679 | list_del(&of->list); | |
680 | ||
85a4ffad TH |
681 | if (atomic_dec_and_test(&od->refcnt)) |
682 | sd->s_attr.open = NULL; | |
683 | else | |
684 | od = NULL; | |
685 | ||
83db93f4 | 686 | spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); |
c75ec764 | 687 | mutex_unlock(&sysfs_open_file_mutex); |
85a4ffad TH |
688 | |
689 | kfree(od); | |
690 | } | |
691 | ||
c6fb4495 | 692 | static int kernfs_file_open(struct inode *inode, struct file *file) |
1da177e4 | 693 | { |
3e519038 | 694 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
f6acf8bb | 695 | const struct kernfs_ops *ops; |
58282d8d | 696 | struct sysfs_open_file *of; |
027a485d | 697 | bool has_read, has_write, has_mmap; |
000f2a4d | 698 | int error = -EACCES; |
1da177e4 | 699 | |
e72ceb8c | 700 | if (!sysfs_get_active(attr_sd)) |
0ab66088 | 701 | return -ENODEV; |
1da177e4 | 702 | |
f6acf8bb | 703 | ops = kernfs_ops(attr_sd); |
1da177e4 | 704 | |
f6acf8bb TH |
705 | has_read = ops->seq_show || ops->read || ops->mmap; |
706 | has_write = ops->write || ops->mmap; | |
707 | has_mmap = ops->mmap; | |
1da177e4 | 708 | |
49fe6047 TH |
709 | /* check perms and supported operations */ |
710 | if ((file->f_mode & FMODE_WRITE) && | |
711 | (!(inode->i_mode & S_IWUGO) || !has_write)) | |
712 | goto err_out; | |
713 | ||
714 | if ((file->f_mode & FMODE_READ) && | |
715 | (!(inode->i_mode & S_IRUGO) || !has_read)) | |
716 | goto err_out; | |
717 | ||
13c589d5 | 718 | /* allocate a sysfs_open_file for the file */ |
0ab66088 | 719 | error = -ENOMEM; |
58282d8d TH |
720 | of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL); |
721 | if (!of) | |
7b595756 | 722 | goto err_out; |
1da177e4 | 723 | |
027a485d TH |
724 | /* |
725 | * The following is done to give a different lockdep key to | |
726 | * @of->mutex for files which implement mmap. This is a rather | |
727 | * crude way to avoid false positive lockdep warning around | |
728 | * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and | |
729 | * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under | |
730 | * which mm->mmap_sem nests, while holding @of->mutex. As each | |
731 | * open file has a separate mutex, it's okay as long as those don't | |
732 | * happen on the same file. At this point, we can't easily give | |
733 | * each file a separate locking class. Let's differentiate on | |
734 | * whether the file has mmap or not for now. | |
735 | */ | |
736 | if (has_mmap) | |
737 | mutex_init(&of->mutex); | |
738 | else | |
739 | mutex_init(&of->mutex); | |
740 | ||
bcafe4ee TH |
741 | of->sd = attr_sd; |
742 | of->file = file; | |
13c589d5 TH |
743 | |
744 | /* | |
49fe6047 TH |
745 | * Always instantiate seq_file even if read access doesn't use |
746 | * seq_file or is not requested. This unifies private data access | |
747 | * and readable regular files are the vast majority anyway. | |
13c589d5 | 748 | */ |
f6acf8bb | 749 | if (ops->seq_show) |
c2b19daf | 750 | error = seq_open(file, &kernfs_seq_ops); |
f6acf8bb TH |
751 | else |
752 | error = seq_open(file, NULL); | |
13c589d5 TH |
753 | if (error) |
754 | goto err_free; | |
755 | ||
c2b19daf TH |
756 | ((struct seq_file *)file->private_data)->private = of; |
757 | ||
13c589d5 TH |
758 | /* seq_file clears PWRITE unconditionally, restore it if WRITE */ |
759 | if (file->f_mode & FMODE_WRITE) | |
760 | file->f_mode |= FMODE_PWRITE; | |
0ab66088 | 761 | |
85a4ffad | 762 | /* make sure we have open dirent struct */ |
58282d8d | 763 | error = sysfs_get_open_dirent(attr_sd, of); |
85a4ffad | 764 | if (error) |
13c589d5 | 765 | goto err_close; |
85a4ffad | 766 | |
b05f0548 | 767 | /* open succeeded, put active references */ |
e72ceb8c | 768 | sysfs_put_active(attr_sd); |
0ab66088 TH |
769 | return 0; |
770 | ||
13c589d5 | 771 | err_close: |
c2b19daf | 772 | seq_release(inode, file); |
13c589d5 | 773 | err_free: |
58282d8d | 774 | kfree(of); |
13c589d5 | 775 | err_out: |
e72ceb8c | 776 | sysfs_put_active(attr_sd); |
1da177e4 LT |
777 | return error; |
778 | } | |
779 | ||
c6fb4495 | 780 | static int kernfs_file_release(struct inode *inode, struct file *filp) |
1da177e4 | 781 | { |
85a4ffad | 782 | struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; |
13c589d5 | 783 | struct sysfs_open_file *of = sysfs_of(filp); |
1da177e4 | 784 | |
58282d8d | 785 | sysfs_put_open_dirent(sd, of); |
c2b19daf | 786 | seq_release(inode, filp); |
58282d8d | 787 | kfree(of); |
50ab1a72 | 788 | |
1da177e4 LT |
789 | return 0; |
790 | } | |
791 | ||
73d97146 TH |
792 | void sysfs_unmap_bin_file(struct sysfs_dirent *sd) |
793 | { | |
794 | struct sysfs_open_dirent *od; | |
795 | struct sysfs_open_file *of; | |
796 | ||
f6acf8bb | 797 | if (!(sd->s_flags & SYSFS_FLAG_HAS_MMAP)) |
73d97146 TH |
798 | return; |
799 | ||
800 | spin_lock_irq(&sysfs_open_dirent_lock); | |
801 | od = sd->s_attr.open; | |
802 | if (od) | |
803 | atomic_inc(&od->refcnt); | |
804 | spin_unlock_irq(&sysfs_open_dirent_lock); | |
805 | if (!od) | |
806 | return; | |
807 | ||
808 | mutex_lock(&sysfs_open_file_mutex); | |
809 | list_for_each_entry(of, &od->files, list) { | |
810 | struct inode *inode = file_inode(of->file); | |
811 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
812 | } | |
813 | mutex_unlock(&sysfs_open_file_mutex); | |
814 | ||
815 | sysfs_put_open_dirent(sd, NULL); | |
816 | } | |
817 | ||
4508a7a7 N |
818 | /* Sysfs attribute files are pollable. The idea is that you read |
819 | * the content and then you use 'poll' or 'select' to wait for | |
820 | * the content to change. When the content changes (assuming the | |
821 | * manager for the kobject supports notification), poll will | |
822 | * return POLLERR|POLLPRI, and select will return the fd whether | |
823 | * it is waiting for read, write, or exceptions. | |
824 | * Once poll/select indicates that the value has changed, you | |
2424b5dd | 825 | * need to close and re-open the file, or seek to 0 and read again. |
4508a7a7 N |
826 | * Reminder: this only works for attributes which actively support |
827 | * it, and it is not possible to test an attribute from userspace | |
a93720ee | 828 | * to see if it supports poll (Neither 'poll' nor 'select' return |
4508a7a7 N |
829 | * an appropriate error code). When in doubt, set a suitable timeout value. |
830 | */ | |
c6fb4495 | 831 | static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) |
4508a7a7 | 832 | { |
13c589d5 | 833 | struct sysfs_open_file *of = sysfs_of(filp); |
0ab66088 | 834 | struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; |
a4e8b912 | 835 | struct sysfs_open_dirent *od = attr_sd->s_attr.open; |
0ab66088 TH |
836 | |
837 | /* need parent for the kobj, grab both */ | |
e72ceb8c | 838 | if (!sysfs_get_active(attr_sd)) |
0ab66088 | 839 | goto trigger; |
4508a7a7 | 840 | |
a4e8b912 | 841 | poll_wait(filp, &od->poll, wait); |
4508a7a7 | 842 | |
e72ceb8c | 843 | sysfs_put_active(attr_sd); |
0ab66088 | 844 | |
58282d8d | 845 | if (of->event != atomic_read(&od->event)) |
0ab66088 | 846 | goto trigger; |
4508a7a7 | 847 | |
1af3557a | 848 | return DEFAULT_POLLMASK; |
0ab66088 TH |
849 | |
850 | trigger: | |
1af3557a | 851 | return DEFAULT_POLLMASK|POLLERR|POLLPRI; |
4508a7a7 N |
852 | } |
853 | ||
024f6471 TH |
854 | /** |
855 | * kernfs_notify - notify a kernfs file | |
856 | * @sd: file to notify | |
857 | * | |
858 | * Notify @sd such that poll(2) on @sd wakes up. | |
859 | */ | |
860 | void kernfs_notify(struct sysfs_dirent *sd) | |
f1282c84 NB |
861 | { |
862 | struct sysfs_open_dirent *od; | |
83db93f4 | 863 | unsigned long flags; |
f1282c84 | 864 | |
83db93f4 | 865 | spin_lock_irqsave(&sysfs_open_dirent_lock, flags); |
f1282c84 | 866 | |
fc60bb83 ND |
867 | if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) { |
868 | od = sd->s_attr.open; | |
869 | if (od) { | |
870 | atomic_inc(&od->event); | |
871 | wake_up_interruptible(&od->poll); | |
872 | } | |
f1282c84 NB |
873 | } |
874 | ||
83db93f4 | 875 | spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); |
f1282c84 | 876 | } |
024f6471 | 877 | EXPORT_SYMBOL_GPL(kernfs_notify); |
f1282c84 | 878 | |
8c0e3998 | 879 | void sysfs_notify(struct kobject *k, const char *dir, const char *attr) |
4508a7a7 | 880 | { |
024f6471 | 881 | struct sysfs_dirent *sd = k->sd, *tmp; |
51225039 TH |
882 | |
883 | if (sd && dir) | |
ccf73cf3 | 884 | sd = kernfs_find_and_get(sd, dir); |
024f6471 | 885 | else |
ccf73cf3 | 886 | kernfs_get(sd); |
024f6471 TH |
887 | |
888 | if (sd && attr) { | |
ccf73cf3 TH |
889 | tmp = kernfs_find_and_get(sd, attr); |
890 | kernfs_put(sd); | |
024f6471 TH |
891 | sd = tmp; |
892 | } | |
51225039 | 893 | |
024f6471 TH |
894 | if (sd) { |
895 | kernfs_notify(sd); | |
ccf73cf3 | 896 | kernfs_put(sd); |
024f6471 | 897 | } |
4508a7a7 N |
898 | } |
899 | EXPORT_SYMBOL_GPL(sysfs_notify); | |
900 | ||
c6fb4495 | 901 | const struct file_operations kernfs_file_operations = { |
c2b19daf | 902 | .read = kernfs_file_read, |
50b38ca0 | 903 | .write = kernfs_file_write, |
044e3bc3 | 904 | .llseek = generic_file_llseek, |
fdbffaa4 | 905 | .mmap = kernfs_file_mmap, |
c6fb4495 TH |
906 | .open = kernfs_file_open, |
907 | .release = kernfs_file_release, | |
908 | .poll = kernfs_file_poll, | |
f9b9a621 TH |
909 | }; |
910 | ||
f6acf8bb TH |
911 | static const struct kernfs_ops sysfs_file_kfops_empty = { |
912 | }; | |
913 | ||
914 | static const struct kernfs_ops sysfs_file_kfops_ro = { | |
915 | .seq_show = sysfs_kf_seq_show, | |
916 | }; | |
917 | ||
918 | static const struct kernfs_ops sysfs_file_kfops_wo = { | |
919 | .write = sysfs_kf_write, | |
920 | }; | |
921 | ||
922 | static const struct kernfs_ops sysfs_file_kfops_rw = { | |
923 | .seq_show = sysfs_kf_seq_show, | |
924 | .write = sysfs_kf_write, | |
925 | }; | |
926 | ||
927 | static const struct kernfs_ops sysfs_bin_kfops_ro = { | |
928 | .read = sysfs_kf_bin_read, | |
929 | }; | |
930 | ||
931 | static const struct kernfs_ops sysfs_bin_kfops_wo = { | |
932 | .write = sysfs_kf_bin_write, | |
933 | }; | |
934 | ||
935 | static const struct kernfs_ops sysfs_bin_kfops_rw = { | |
936 | .read = sysfs_kf_bin_read, | |
937 | .write = sysfs_kf_bin_write, | |
938 | .mmap = sysfs_kf_bin_mmap, | |
939 | }; | |
940 | ||
58292cbe | 941 | int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, |
a7dc66df | 942 | const struct attribute *attr, bool is_bin, |
496f7394 | 943 | umode_t mode, const void *ns) |
1da177e4 | 944 | { |
517e64f5 | 945 | struct lock_class_key *key = NULL; |
f6acf8bb | 946 | const struct kernfs_ops *ops; |
a26cd722 | 947 | struct sysfs_dirent *sd; |
471bd7b7 | 948 | loff_t size; |
1da177e4 | 949 | |
a7dc66df | 950 | if (!is_bin) { |
f6acf8bb TH |
951 | struct kobject *kobj = dir_sd->priv; |
952 | const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; | |
953 | ||
954 | /* every kobject with an attribute needs a ktype assigned */ | |
955 | if (WARN(!sysfs_ops, KERN_ERR | |
956 | "missing sysfs attribute operations for kobject: %s\n", | |
957 | kobject_name(kobj))) | |
958 | return -EINVAL; | |
959 | ||
960 | if (sysfs_ops->show && sysfs_ops->store) | |
961 | ops = &sysfs_file_kfops_rw; | |
962 | else if (sysfs_ops->show) | |
963 | ops = &sysfs_file_kfops_ro; | |
964 | else if (sysfs_ops->store) | |
965 | ops = &sysfs_file_kfops_wo; | |
966 | else | |
967 | ops = &sysfs_file_kfops_empty; | |
471bd7b7 TH |
968 | |
969 | size = PAGE_SIZE; | |
f6acf8bb TH |
970 | } else { |
971 | struct bin_attribute *battr = (void *)attr; | |
972 | ||
973 | if ((battr->read && battr->write) || battr->mmap) | |
974 | ops = &sysfs_bin_kfops_rw; | |
975 | else if (battr->read) | |
976 | ops = &sysfs_bin_kfops_ro; | |
977 | else if (battr->write) | |
978 | ops = &sysfs_bin_kfops_wo; | |
979 | else | |
980 | ops = &sysfs_file_kfops_empty; | |
471bd7b7 TH |
981 | |
982 | size = battr->size; | |
f6acf8bb TH |
983 | } |
984 | ||
517e64f5 TH |
985 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
986 | if (!attr->ignore_lockdep) | |
987 | key = attr->key ?: (struct lock_class_key *)&attr->skey; | |
988 | #endif | |
989 | sd = kernfs_create_file_ns_key(dir_sd, attr->name, mode, size, | |
990 | ops, (void *)attr, ns, key); | |
496f7394 TH |
991 | if (IS_ERR(sd)) { |
992 | if (PTR_ERR(sd) == -EEXIST) | |
993 | sysfs_warn_dup(dir_sd, attr->name); | |
994 | return PTR_ERR(sd); | |
995 | } | |
996 | return 0; | |
997 | } | |
998 | ||
999 | /** | |
517e64f5 | 1000 | * kernfs_create_file_ns_key - create a file |
496f7394 TH |
1001 | * @parent: directory to create the file in |
1002 | * @name: name of the file | |
1003 | * @mode: mode of the file | |
1004 | * @size: size of the file | |
1005 | * @ops: kernfs operations for the file | |
1006 | * @priv: private data for the file | |
1007 | * @ns: optional namespace tag of the file | |
517e64f5 | 1008 | * @key: lockdep key for the file's active_ref, %NULL to disable lockdep |
496f7394 TH |
1009 | * |
1010 | * Returns the created node on success, ERR_PTR() value on error. | |
1011 | */ | |
517e64f5 TH |
1012 | struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, |
1013 | const char *name, | |
1014 | umode_t mode, loff_t size, | |
1015 | const struct kernfs_ops *ops, | |
1016 | void *priv, const void *ns, | |
1017 | struct lock_class_key *key) | |
496f7394 TH |
1018 | { |
1019 | struct sysfs_addrm_cxt acxt; | |
1020 | struct sysfs_dirent *sd; | |
1021 | int rc; | |
1022 | ||
1023 | sd = sysfs_new_dirent(name, (mode & S_IALLUGO) | S_IFREG, | |
1024 | SYSFS_KOBJ_ATTR); | |
3007e997 | 1025 | if (!sd) |
496f7394 | 1026 | return ERR_PTR(-ENOMEM); |
487505c2 | 1027 | |
f6acf8bb | 1028 | sd->s_attr.ops = ops; |
471bd7b7 | 1029 | sd->s_attr.size = size; |
487505c2 | 1030 | sd->s_ns = ns; |
496f7394 | 1031 | sd->priv = priv; |
517e64f5 TH |
1032 | |
1033 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
1034 | if (key) { | |
1035 | lockdep_init_map(&sd->dep_map, "s_active", key, 0); | |
1036 | sd->s_flags |= SYSFS_FLAG_LOCKDEP; | |
1037 | } | |
1038 | #endif | |
1da177e4 | 1039 | |
f6acf8bb TH |
1040 | /* |
1041 | * sd->s_attr.ops is accesible only while holding active ref. We | |
1042 | * need to know whether some ops are implemented outside active | |
1043 | * ref. Cache their existence in flags. | |
1044 | */ | |
1045 | if (ops->seq_show) | |
1046 | sd->s_flags |= SYSFS_FLAG_HAS_SEQ_SHOW; | |
1047 | if (ops->mmap) | |
1048 | sd->s_flags |= SYSFS_FLAG_HAS_MMAP; | |
1049 | ||
d69ac5a0 | 1050 | sysfs_addrm_start(&acxt); |
2d0cfbec | 1051 | rc = sysfs_add_one(&acxt, sd, parent); |
23dc2799 | 1052 | sysfs_addrm_finish(&acxt); |
a26cd722 | 1053 | |
496f7394 | 1054 | if (rc) { |
ccf73cf3 | 1055 | kernfs_put(sd); |
496f7394 TH |
1056 | return ERR_PTR(rc); |
1057 | } | |
1058 | return sd; | |
1da177e4 LT |
1059 | } |
1060 | ||
0f423895 | 1061 | int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, |
a7dc66df | 1062 | bool is_bin) |
0f423895 | 1063 | { |
a7dc66df | 1064 | return sysfs_add_file_mode_ns(dir_sd, attr, is_bin, attr->mode, NULL); |
0f423895 JB |
1065 | } |
1066 | ||
1da177e4 | 1067 | /** |
58292cbe TH |
1068 | * sysfs_create_file_ns - create an attribute file for an object with custom ns |
1069 | * @kobj: object we're creating for | |
1070 | * @attr: attribute descriptor | |
1071 | * @ns: namespace the new file should belong to | |
1da177e4 | 1072 | */ |
58292cbe TH |
1073 | int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, |
1074 | const void *ns) | |
1da177e4 | 1075 | { |
608e266a | 1076 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 1077 | |
a7dc66df | 1078 | return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns); |
1da177e4 LT |
1079 | |
1080 | } | |
58292cbe | 1081 | EXPORT_SYMBOL_GPL(sysfs_create_file_ns); |
1da177e4 | 1082 | |
1c205ae1 AK |
1083 | int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr) |
1084 | { | |
1085 | int err = 0; | |
1086 | int i; | |
1087 | ||
1088 | for (i = 0; ptr[i] && !err; i++) | |
1089 | err = sysfs_create_file(kobj, ptr[i]); | |
1090 | if (err) | |
1091 | while (--i >= 0) | |
1092 | sysfs_remove_file(kobj, ptr[i]); | |
1093 | return err; | |
1094 | } | |
1b866757 | 1095 | EXPORT_SYMBOL_GPL(sysfs_create_files); |
1da177e4 | 1096 | |
dfa87c82 AS |
1097 | /** |
1098 | * sysfs_add_file_to_group - add an attribute file to a pre-existing group. | |
1099 | * @kobj: object we're acting for. | |
1100 | * @attr: attribute descriptor. | |
1101 | * @group: group name. | |
1102 | */ | |
1103 | int sysfs_add_file_to_group(struct kobject *kobj, | |
1104 | const struct attribute *attr, const char *group) | |
1105 | { | |
608e266a | 1106 | struct sysfs_dirent *dir_sd; |
dfa87c82 AS |
1107 | int error; |
1108 | ||
ccf73cf3 TH |
1109 | if (group) { |
1110 | dir_sd = kernfs_find_and_get(kobj->sd, group); | |
1111 | } else { | |
1112 | dir_sd = kobj->sd; | |
1113 | kernfs_get(dir_sd); | |
1114 | } | |
11f24fbd | 1115 | |
608e266a TH |
1116 | if (!dir_sd) |
1117 | return -ENOENT; | |
1118 | ||
a7dc66df | 1119 | error = sysfs_add_file(dir_sd, attr, false); |
ccf73cf3 | 1120 | kernfs_put(dir_sd); |
608e266a | 1121 | |
dfa87c82 AS |
1122 | return error; |
1123 | } | |
1124 | EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); | |
1125 | ||
31e5abe9 KS |
1126 | /** |
1127 | * sysfs_chmod_file - update the modified mode value on an object attribute. | |
1128 | * @kobj: object we're acting for. | |
1129 | * @attr: attribute descriptor. | |
1130 | * @mode: file permissions. | |
1131 | * | |
1132 | */ | |
49c19400 | 1133 | int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, |
48176a97 | 1134 | umode_t mode) |
31e5abe9 | 1135 | { |
06fc0d66 | 1136 | struct sysfs_dirent *sd; |
bc062b1b | 1137 | struct iattr newattrs; |
51225039 TH |
1138 | int rc; |
1139 | ||
ccf73cf3 | 1140 | sd = kernfs_find_and_get(kobj->sd, attr->name); |
06fc0d66 | 1141 | if (!sd) |
5d60418e | 1142 | return -ENOENT; |
f88123ea | 1143 | |
06fc0d66 | 1144 | newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); |
4c6974f5 | 1145 | newattrs.ia_valid = ATTR_MODE; |
f88123ea | 1146 | |
5d60418e TH |
1147 | rc = kernfs_setattr(sd, &newattrs); |
1148 | ||
ccf73cf3 | 1149 | kernfs_put(sd); |
51225039 | 1150 | return rc; |
31e5abe9 KS |
1151 | } |
1152 | EXPORT_SYMBOL_GPL(sysfs_chmod_file); | |
1153 | ||
1da177e4 | 1154 | /** |
58292cbe TH |
1155 | * sysfs_remove_file_ns - remove an object attribute with a custom ns tag |
1156 | * @kobj: object we're acting for | |
1157 | * @attr: attribute descriptor | |
1158 | * @ns: namespace tag of the file to remove | |
1da177e4 | 1159 | * |
58292cbe | 1160 | * Hash the attribute name and namespace tag and kill the victim. |
1da177e4 | 1161 | */ |
58292cbe TH |
1162 | void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, |
1163 | const void *ns) | |
1da177e4 | 1164 | { |
58292cbe | 1165 | struct sysfs_dirent *dir_sd = kobj->sd; |
487505c2 | 1166 | |
879f40d1 | 1167 | kernfs_remove_by_name_ns(dir_sd, attr->name, ns); |
1da177e4 | 1168 | } |
58292cbe | 1169 | EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); |
1da177e4 | 1170 | |
1b18dc2b | 1171 | void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr) |
1c205ae1 AK |
1172 | { |
1173 | int i; | |
1174 | for (i = 0; ptr[i]; i++) | |
1175 | sysfs_remove_file(kobj, ptr[i]); | |
1176 | } | |
1b866757 | 1177 | EXPORT_SYMBOL_GPL(sysfs_remove_files); |
1da177e4 | 1178 | |
dfa87c82 AS |
1179 | /** |
1180 | * sysfs_remove_file_from_group - remove an attribute file from a group. | |
1181 | * @kobj: object we're acting for. | |
1182 | * @attr: attribute descriptor. | |
1183 | * @group: group name. | |
1184 | */ | |
1185 | void sysfs_remove_file_from_group(struct kobject *kobj, | |
1186 | const struct attribute *attr, const char *group) | |
1187 | { | |
608e266a | 1188 | struct sysfs_dirent *dir_sd; |
dfa87c82 | 1189 | |
ccf73cf3 TH |
1190 | if (group) { |
1191 | dir_sd = kernfs_find_and_get(kobj->sd, group); | |
1192 | } else { | |
1193 | dir_sd = kobj->sd; | |
1194 | kernfs_get(dir_sd); | |
1195 | } | |
1196 | ||
608e266a | 1197 | if (dir_sd) { |
879f40d1 | 1198 | kernfs_remove_by_name(dir_sd, attr->name); |
ccf73cf3 | 1199 | kernfs_put(dir_sd); |
dfa87c82 AS |
1200 | } |
1201 | } | |
1202 | EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); | |
1203 | ||
3124eb16 TH |
1204 | /** |
1205 | * sysfs_create_bin_file - create binary file for object. | |
1206 | * @kobj: object. | |
1207 | * @attr: attribute descriptor. | |
1208 | */ | |
1209 | int sysfs_create_bin_file(struct kobject *kobj, | |
1210 | const struct bin_attribute *attr) | |
1211 | { | |
1212 | BUG_ON(!kobj || !kobj->sd || !attr); | |
1213 | ||
a7dc66df | 1214 | return sysfs_add_file(kobj->sd, &attr->attr, true); |
3124eb16 TH |
1215 | } |
1216 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
1217 | ||
1218 | /** | |
1219 | * sysfs_remove_bin_file - remove binary file for object. | |
1220 | * @kobj: object. | |
1221 | * @attr: attribute descriptor. | |
1222 | */ | |
1223 | void sysfs_remove_bin_file(struct kobject *kobj, | |
1224 | const struct bin_attribute *attr) | |
1225 | { | |
879f40d1 | 1226 | kernfs_remove_by_name(kobj->sd, attr->attr.name); |
3124eb16 TH |
1227 | } |
1228 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); | |
1229 | ||
d9a9cdfb | 1230 | struct sysfs_schedule_callback_struct { |
66942064 AC |
1231 | struct list_head workq_list; |
1232 | struct kobject *kobj; | |
d9a9cdfb AS |
1233 | void (*func)(void *); |
1234 | void *data; | |
523ded71 | 1235 | struct module *owner; |
d9a9cdfb AS |
1236 | struct work_struct work; |
1237 | }; | |
1238 | ||
d110271e | 1239 | static struct workqueue_struct *sysfs_workqueue; |
66942064 AC |
1240 | static DEFINE_MUTEX(sysfs_workq_mutex); |
1241 | static LIST_HEAD(sysfs_workq); | |
d9a9cdfb AS |
1242 | static void sysfs_schedule_callback_work(struct work_struct *work) |
1243 | { | |
1244 | struct sysfs_schedule_callback_struct *ss = container_of(work, | |
1245 | struct sysfs_schedule_callback_struct, work); | |
1246 | ||
1247 | (ss->func)(ss->data); | |
1248 | kobject_put(ss->kobj); | |
523ded71 | 1249 | module_put(ss->owner); |
66942064 AC |
1250 | mutex_lock(&sysfs_workq_mutex); |
1251 | list_del(&ss->workq_list); | |
1252 | mutex_unlock(&sysfs_workq_mutex); | |
d9a9cdfb AS |
1253 | kfree(ss); |
1254 | } | |
1255 | ||
1256 | /** | |
1257 | * sysfs_schedule_callback - helper to schedule a callback for a kobject | |
1258 | * @kobj: object we're acting for. | |
1259 | * @func: callback function to invoke later. | |
1260 | * @data: argument to pass to @func. | |
523ded71 | 1261 | * @owner: module owning the callback code |
d9a9cdfb AS |
1262 | * |
1263 | * sysfs attribute methods must not unregister themselves or their parent | |
1264 | * kobject (which would amount to the same thing). Attempts to do so will | |
1265 | * deadlock, since unregistration is mutually exclusive with driver | |
1266 | * callbacks. | |
1267 | * | |
1268 | * Instead methods can call this routine, which will attempt to allocate | |
1269 | * and schedule a workqueue request to call back @func with @data as its | |
1270 | * argument in the workqueue's process context. @kobj will be pinned | |
1271 | * until @func returns. | |
1272 | * | |
1273 | * Returns 0 if the request was submitted, -ENOMEM if storage could not | |
66942064 AC |
1274 | * be allocated, -ENODEV if a reference to @owner isn't available, |
1275 | * -EAGAIN if a callback has already been scheduled for @kobj. | |
d9a9cdfb AS |
1276 | */ |
1277 | int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), | |
523ded71 | 1278 | void *data, struct module *owner) |
d9a9cdfb | 1279 | { |
66942064 | 1280 | struct sysfs_schedule_callback_struct *ss, *tmp; |
d9a9cdfb | 1281 | |
523ded71 AS |
1282 | if (!try_module_get(owner)) |
1283 | return -ENODEV; | |
66942064 AC |
1284 | |
1285 | mutex_lock(&sysfs_workq_mutex); | |
1286 | list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list) | |
1287 | if (ss->kobj == kobj) { | |
d110271e | 1288 | module_put(owner); |
66942064 AC |
1289 | mutex_unlock(&sysfs_workq_mutex); |
1290 | return -EAGAIN; | |
1291 | } | |
1292 | mutex_unlock(&sysfs_workq_mutex); | |
1293 | ||
d110271e | 1294 | if (sysfs_workqueue == NULL) { |
086a377e | 1295 | sysfs_workqueue = create_singlethread_workqueue("sysfsd"); |
d110271e AC |
1296 | if (sysfs_workqueue == NULL) { |
1297 | module_put(owner); | |
1298 | return -ENOMEM; | |
1299 | } | |
1300 | } | |
1301 | ||
d9a9cdfb | 1302 | ss = kmalloc(sizeof(*ss), GFP_KERNEL); |
523ded71 AS |
1303 | if (!ss) { |
1304 | module_put(owner); | |
d9a9cdfb | 1305 | return -ENOMEM; |
523ded71 | 1306 | } |
d9a9cdfb AS |
1307 | kobject_get(kobj); |
1308 | ss->kobj = kobj; | |
1309 | ss->func = func; | |
1310 | ss->data = data; | |
523ded71 | 1311 | ss->owner = owner; |
d9a9cdfb | 1312 | INIT_WORK(&ss->work, sysfs_schedule_callback_work); |
66942064 AC |
1313 | INIT_LIST_HEAD(&ss->workq_list); |
1314 | mutex_lock(&sysfs_workq_mutex); | |
1315 | list_add_tail(&ss->workq_list, &sysfs_workq); | |
1316 | mutex_unlock(&sysfs_workq_mutex); | |
d110271e | 1317 | queue_work(sysfs_workqueue, &ss->work); |
d9a9cdfb AS |
1318 | return 0; |
1319 | } | |
1320 | EXPORT_SYMBOL_GPL(sysfs_schedule_callback); |