Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
6d66f5cd | 2 | * fs/sysfs/bin.c - sysfs binary file implementation |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Matthew Wilcox | |
6 | * Copyright (c) 2004 Silicon Graphics, Inc. | |
6d66f5cd TH |
7 | * Copyright (c) 2007 SUSE Linux Products GmbH |
8 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
9 | * | |
10 | * This file is released under the GPLv2. | |
11 | * | |
12 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
13 | */ |
14 | ||
15 | #undef DEBUG | |
16 | ||
17 | #include <linux/errno.h> | |
18 | #include <linux/fs.h> | |
995982ca | 19 | #include <linux/kernel.h> |
1da177e4 LT |
20 | #include <linux/kobject.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/slab.h> | |
869512ab | 23 | #include <linux/mutex.h> |
e0edd3c6 | 24 | #include <linux/mm.h> |
1da177e4 LT |
25 | |
26 | #include <asm/uaccess.h> | |
27 | ||
28 | #include "sysfs.h" | |
29 | ||
e0edd3c6 EB |
30 | /* |
31 | * There's one bin_buffer for each open file. | |
32 | * | |
33 | * filp->private_data points to bin_buffer and | |
34 | * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s | |
35 | * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock | |
36 | */ | |
37 | static DEFINE_MUTEX(sysfs_bin_lock); | |
38 | ||
eb361653 | 39 | struct bin_buffer { |
e0edd3c6 EB |
40 | struct mutex mutex; |
41 | void *buffer; | |
42 | int mmapped; | |
43 | struct vm_operations_struct *vm_ops; | |
44 | struct file *file; | |
45 | struct hlist_node list; | |
eb361653 TH |
46 | }; |
47 | ||
1da177e4 LT |
48 | static int |
49 | fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) | |
50 | { | |
3e519038 | 51 | struct sysfs_dirent *attr_sd = dentry->d_fsdata; |
b1fc3d61 TH |
52 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
53 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
0ab66088 TH |
54 | int rc; |
55 | ||
56 | /* need attr_sd for attr, its parent for kobj */ | |
57 | if (!sysfs_get_active_two(attr_sd)) | |
58 | return -ENODEV; | |
1da177e4 | 59 | |
0ab66088 TH |
60 | rc = -EIO; |
61 | if (attr->read) | |
91a69029 | 62 | rc = attr->read(kobj, attr, buffer, off, count); |
1da177e4 | 63 | |
0ab66088 TH |
64 | sysfs_put_active_two(attr_sd); |
65 | ||
66 | return rc; | |
1da177e4 LT |
67 | } |
68 | ||
69 | static ssize_t | |
93e3cd82 | 70 | read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) |
1da177e4 | 71 | { |
eb361653 | 72 | struct bin_buffer *bb = file->private_data; |
f427f5d5 | 73 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
74 | int size = dentry->d_inode->i_size; |
75 | loff_t offs = *off; | |
93e3cd82 | 76 | int count = min_t(size_t, bytes, PAGE_SIZE); |
b31ca3f5 | 77 | char *temp; |
1da177e4 | 78 | |
4503efd0 GKH |
79 | if (!bytes) |
80 | return 0; | |
81 | ||
1da177e4 LT |
82 | if (size) { |
83 | if (offs > size) | |
84 | return 0; | |
85 | if (offs + count > size) | |
86 | count = size - offs; | |
87 | } | |
88 | ||
b31ca3f5 NP |
89 | temp = kmalloc(count, GFP_KERNEL); |
90 | if (!temp) | |
91 | return -ENOMEM; | |
92 | ||
eb361653 TH |
93 | mutex_lock(&bb->mutex); |
94 | ||
95 | count = fill_read(dentry, bb->buffer, offs, count); | |
b31ca3f5 NP |
96 | if (count < 0) { |
97 | mutex_unlock(&bb->mutex); | |
98 | goto out_free; | |
99 | } | |
1da177e4 | 100 | |
b31ca3f5 NP |
101 | memcpy(temp, bb->buffer, count); |
102 | ||
103 | mutex_unlock(&bb->mutex); | |
104 | ||
105 | if (copy_to_user(userbuf, temp, count)) { | |
eb361653 | 106 | count = -EFAULT; |
b31ca3f5 | 107 | goto out_free; |
eb361653 | 108 | } |
1da177e4 | 109 | |
93e3cd82 | 110 | pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); |
1da177e4 LT |
111 | |
112 | *off = offs + count; | |
113 | ||
b31ca3f5 NP |
114 | out_free: |
115 | kfree(temp); | |
1da177e4 LT |
116 | return count; |
117 | } | |
118 | ||
119 | static int | |
120 | flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) | |
121 | { | |
3e519038 | 122 | struct sysfs_dirent *attr_sd = dentry->d_fsdata; |
b1fc3d61 TH |
123 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
124 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
0ab66088 TH |
125 | int rc; |
126 | ||
127 | /* need attr_sd for attr, its parent for kobj */ | |
128 | if (!sysfs_get_active_two(attr_sd)) | |
129 | return -ENODEV; | |
1da177e4 | 130 | |
0ab66088 TH |
131 | rc = -EIO; |
132 | if (attr->write) | |
91a69029 | 133 | rc = attr->write(kobj, attr, buffer, offset, count); |
1da177e4 | 134 | |
0ab66088 TH |
135 | sysfs_put_active_two(attr_sd); |
136 | ||
137 | return rc; | |
1da177e4 LT |
138 | } |
139 | ||
93e3cd82 TH |
140 | static ssize_t write(struct file *file, const char __user *userbuf, |
141 | size_t bytes, loff_t *off) | |
1da177e4 | 142 | { |
eb361653 | 143 | struct bin_buffer *bb = file->private_data; |
f427f5d5 | 144 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
145 | int size = dentry->d_inode->i_size; |
146 | loff_t offs = *off; | |
93e3cd82 | 147 | int count = min_t(size_t, bytes, PAGE_SIZE); |
b31ca3f5 | 148 | char *temp; |
1da177e4 | 149 | |
4503efd0 GKH |
150 | if (!bytes) |
151 | return 0; | |
152 | ||
1da177e4 LT |
153 | if (size) { |
154 | if (offs > size) | |
155 | return 0; | |
156 | if (offs + count > size) | |
157 | count = size - offs; | |
158 | } | |
159 | ||
b31ca3f5 NP |
160 | temp = kmalloc(count, GFP_KERNEL); |
161 | if (!temp) | |
162 | return -ENOMEM; | |
eb361653 | 163 | |
b31ca3f5 | 164 | if (copy_from_user(temp, userbuf, count)) { |
eb361653 | 165 | count = -EFAULT; |
b31ca3f5 | 166 | goto out_free; |
eb361653 | 167 | } |
1da177e4 | 168 | |
b31ca3f5 NP |
169 | mutex_lock(&bb->mutex); |
170 | ||
171 | memcpy(bb->buffer, temp, count); | |
172 | ||
eb361653 | 173 | count = flush_write(dentry, bb->buffer, offs, count); |
b31ca3f5 NP |
174 | mutex_unlock(&bb->mutex); |
175 | ||
1da177e4 LT |
176 | if (count > 0) |
177 | *off = offs + count; | |
eb361653 | 178 | |
b31ca3f5 NP |
179 | out_free: |
180 | kfree(temp); | |
1da177e4 LT |
181 | return count; |
182 | } | |
183 | ||
e0edd3c6 EB |
184 | static void bin_vma_open(struct vm_area_struct *vma) |
185 | { | |
186 | struct file *file = vma->vm_file; | |
187 | struct bin_buffer *bb = file->private_data; | |
188 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
189 | ||
190 | if (!bb->vm_ops || !bb->vm_ops->open) | |
191 | return; | |
192 | ||
193 | if (!sysfs_get_active_two(attr_sd)) | |
194 | return; | |
195 | ||
196 | bb->vm_ops->open(vma); | |
197 | ||
198 | sysfs_put_active_two(attr_sd); | |
199 | } | |
200 | ||
201 | static void bin_vma_close(struct vm_area_struct *vma) | |
202 | { | |
203 | struct file *file = vma->vm_file; | |
204 | struct bin_buffer *bb = file->private_data; | |
205 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
206 | ||
207 | if (!bb->vm_ops || !bb->vm_ops->close) | |
208 | return; | |
209 | ||
210 | if (!sysfs_get_active_two(attr_sd)) | |
211 | return; | |
212 | ||
213 | bb->vm_ops->close(vma); | |
214 | ||
215 | sysfs_put_active_two(attr_sd); | |
216 | } | |
217 | ||
218 | static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
219 | { | |
220 | struct file *file = vma->vm_file; | |
221 | struct bin_buffer *bb = file->private_data; | |
222 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
223 | int ret; | |
224 | ||
225 | if (!bb->vm_ops || !bb->vm_ops->fault) | |
226 | return VM_FAULT_SIGBUS; | |
227 | ||
228 | if (!sysfs_get_active_two(attr_sd)) | |
229 | return VM_FAULT_SIGBUS; | |
230 | ||
231 | ret = bb->vm_ops->fault(vma, vmf); | |
232 | ||
233 | sysfs_put_active_two(attr_sd); | |
234 | return ret; | |
235 | } | |
236 | ||
237 | static int bin_page_mkwrite(struct vm_area_struct *vma, struct page *page) | |
238 | { | |
239 | struct file *file = vma->vm_file; | |
240 | struct bin_buffer *bb = file->private_data; | |
241 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
242 | int ret; | |
243 | ||
095160ae | 244 | if (!bb->vm_ops) |
e0edd3c6 EB |
245 | return -EINVAL; |
246 | ||
095160ae HD |
247 | if (!bb->vm_ops->page_mkwrite) |
248 | return 0; | |
249 | ||
e0edd3c6 EB |
250 | if (!sysfs_get_active_two(attr_sd)) |
251 | return -EINVAL; | |
252 | ||
253 | ret = bb->vm_ops->page_mkwrite(vma, page); | |
254 | ||
255 | sysfs_put_active_two(attr_sd); | |
256 | return ret; | |
257 | } | |
258 | ||
259 | static int bin_access(struct vm_area_struct *vma, unsigned long addr, | |
260 | void *buf, int len, int write) | |
261 | { | |
262 | struct file *file = vma->vm_file; | |
263 | struct bin_buffer *bb = file->private_data; | |
264 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
265 | int ret; | |
266 | ||
267 | if (!bb->vm_ops || !bb->vm_ops->access) | |
268 | return -EINVAL; | |
269 | ||
270 | if (!sysfs_get_active_two(attr_sd)) | |
271 | return -EINVAL; | |
272 | ||
273 | ret = bb->vm_ops->access(vma, addr, buf, len, write); | |
274 | ||
275 | sysfs_put_active_two(attr_sd); | |
276 | return ret; | |
277 | } | |
278 | ||
095160ae HD |
279 | #ifdef CONFIG_NUMA |
280 | static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) | |
281 | { | |
282 | struct file *file = vma->vm_file; | |
283 | struct bin_buffer *bb = file->private_data; | |
284 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
285 | int ret; | |
286 | ||
287 | if (!bb->vm_ops || !bb->vm_ops->set_policy) | |
288 | return 0; | |
289 | ||
290 | if (!sysfs_get_active_two(attr_sd)) | |
291 | return -EINVAL; | |
292 | ||
293 | ret = bb->vm_ops->set_policy(vma, new); | |
294 | ||
295 | sysfs_put_active_two(attr_sd); | |
296 | return ret; | |
297 | } | |
298 | ||
299 | static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, | |
300 | unsigned long addr) | |
301 | { | |
302 | struct file *file = vma->vm_file; | |
303 | struct bin_buffer *bb = file->private_data; | |
304 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
305 | struct mempolicy *pol; | |
306 | ||
307 | if (!bb->vm_ops || !bb->vm_ops->get_policy) | |
308 | return vma->vm_policy; | |
309 | ||
310 | if (!sysfs_get_active_two(attr_sd)) | |
311 | return vma->vm_policy; | |
312 | ||
313 | pol = bb->vm_ops->get_policy(vma, addr); | |
314 | ||
315 | sysfs_put_active_two(attr_sd); | |
316 | return pol; | |
317 | } | |
318 | ||
319 | static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, | |
320 | const nodemask_t *to, unsigned long flags) | |
321 | { | |
322 | struct file *file = vma->vm_file; | |
323 | struct bin_buffer *bb = file->private_data; | |
324 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
325 | int ret; | |
326 | ||
327 | if (!bb->vm_ops || !bb->vm_ops->migrate) | |
328 | return 0; | |
329 | ||
330 | if (!sysfs_get_active_two(attr_sd)) | |
331 | return 0; | |
332 | ||
333 | ret = bb->vm_ops->migrate(vma, from, to, flags); | |
334 | ||
335 | sysfs_put_active_two(attr_sd); | |
336 | return ret; | |
337 | } | |
338 | #endif | |
339 | ||
e0edd3c6 EB |
340 | static struct vm_operations_struct bin_vm_ops = { |
341 | .open = bin_vma_open, | |
342 | .close = bin_vma_close, | |
343 | .fault = bin_fault, | |
344 | .page_mkwrite = bin_page_mkwrite, | |
345 | .access = bin_access, | |
095160ae HD |
346 | #ifdef CONFIG_NUMA |
347 | .set_policy = bin_set_policy, | |
348 | .get_policy = bin_get_policy, | |
349 | .migrate = bin_migrate, | |
350 | #endif | |
e0edd3c6 EB |
351 | }; |
352 | ||
1da177e4 LT |
353 | static int mmap(struct file *file, struct vm_area_struct *vma) |
354 | { | |
eb361653 | 355 | struct bin_buffer *bb = file->private_data; |
3e519038 | 356 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 TH |
357 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
358 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
eb361653 | 359 | int rc; |
1da177e4 | 360 | |
eb361653 | 361 | mutex_lock(&bb->mutex); |
0ab66088 TH |
362 | |
363 | /* need attr_sd for attr, its parent for kobj */ | |
e0edd3c6 | 364 | rc = -ENODEV; |
0ab66088 | 365 | if (!sysfs_get_active_two(attr_sd)) |
e0edd3c6 | 366 | goto out_unlock; |
0ab66088 TH |
367 | |
368 | rc = -EINVAL; | |
e0edd3c6 EB |
369 | if (!attr->mmap) |
370 | goto out_put; | |
0ab66088 | 371 | |
e0edd3c6 | 372 | rc = attr->mmap(kobj, attr, vma); |
e0edd3c6 EB |
373 | if (rc) |
374 | goto out_put; | |
0ab66088 | 375 | |
095160ae HD |
376 | /* |
377 | * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() | |
378 | * to satisfy versions of X which crash if the mmap fails: that | |
379 | * substitutes a new vm_file, and we don't then want bin_vm_ops. | |
380 | */ | |
381 | if (vma->vm_file != file) | |
e0edd3c6 EB |
382 | goto out_put; |
383 | ||
e0edd3c6 | 384 | rc = -EINVAL; |
095160ae | 385 | if (bb->mmapped && bb->vm_ops != vma->vm_ops) |
e0edd3c6 | 386 | goto out_put; |
e0edd3c6 EB |
387 | |
388 | rc = 0; | |
389 | bb->mmapped = 1; | |
095160ae HD |
390 | bb->vm_ops = vma->vm_ops; |
391 | vma->vm_ops = &bin_vm_ops; | |
e0edd3c6 EB |
392 | out_put: |
393 | sysfs_put_active_two(attr_sd); | |
394 | out_unlock: | |
eb361653 TH |
395 | mutex_unlock(&bb->mutex); |
396 | ||
397 | return rc; | |
1da177e4 LT |
398 | } |
399 | ||
400 | static int open(struct inode * inode, struct file * file) | |
401 | { | |
3e519038 | 402 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 | 403 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
eb361653 | 404 | struct bin_buffer *bb = NULL; |
0ab66088 | 405 | int error; |
1da177e4 | 406 | |
078ce640 TH |
407 | /* binary file operations requires both @sd and its parent */ |
408 | if (!sysfs_get_active_two(attr_sd)) | |
0ab66088 | 409 | return -ENODEV; |
1da177e4 | 410 | |
1da177e4 LT |
411 | error = -EACCES; |
412 | if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) | |
7b595756 | 413 | goto err_out; |
1da177e4 | 414 | if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) |
7b595756 | 415 | goto err_out; |
1da177e4 LT |
416 | |
417 | error = -ENOMEM; | |
eb361653 TH |
418 | bb = kzalloc(sizeof(*bb), GFP_KERNEL); |
419 | if (!bb) | |
7b595756 | 420 | goto err_out; |
1da177e4 | 421 | |
eb361653 TH |
422 | bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
423 | if (!bb->buffer) | |
7b595756 | 424 | goto err_out; |
eb361653 TH |
425 | |
426 | mutex_init(&bb->mutex); | |
e0edd3c6 | 427 | bb->file = file; |
eb361653 TH |
428 | file->private_data = bb; |
429 | ||
e0edd3c6 EB |
430 | mutex_lock(&sysfs_bin_lock); |
431 | hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers); | |
432 | mutex_unlock(&sysfs_bin_lock); | |
433 | ||
078ce640 TH |
434 | /* open succeeded, put active references */ |
435 | sysfs_put_active_two(attr_sd); | |
0ab66088 | 436 | return 0; |
1da177e4 | 437 | |
7b595756 | 438 | err_out: |
078ce640 | 439 | sysfs_put_active_two(attr_sd); |
0ab66088 | 440 | kfree(bb); |
1da177e4 LT |
441 | return error; |
442 | } | |
443 | ||
444 | static int release(struct inode * inode, struct file * file) | |
445 | { | |
eb361653 | 446 | struct bin_buffer *bb = file->private_data; |
1da177e4 | 447 | |
e0edd3c6 EB |
448 | mutex_lock(&sysfs_bin_lock); |
449 | hlist_del(&bb->list); | |
450 | mutex_unlock(&sysfs_bin_lock); | |
451 | ||
eb361653 TH |
452 | kfree(bb->buffer); |
453 | kfree(bb); | |
1da177e4 LT |
454 | return 0; |
455 | } | |
456 | ||
4b6f5d20 | 457 | const struct file_operations bin_fops = { |
1da177e4 LT |
458 | .read = read, |
459 | .write = write, | |
460 | .mmap = mmap, | |
461 | .llseek = generic_file_llseek, | |
462 | .open = open, | |
463 | .release = release, | |
464 | }; | |
465 | ||
e0edd3c6 EB |
466 | |
467 | void unmap_bin_file(struct sysfs_dirent *attr_sd) | |
468 | { | |
469 | struct bin_buffer *bb; | |
470 | struct hlist_node *tmp; | |
471 | ||
472 | if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR) | |
473 | return; | |
474 | ||
475 | mutex_lock(&sysfs_bin_lock); | |
476 | ||
477 | hlist_for_each_entry(bb, tmp, &attr_sd->s_bin_attr.buffers, list) { | |
478 | struct inode *inode = bb->file->f_path.dentry->d_inode; | |
479 | ||
480 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
481 | } | |
482 | ||
483 | mutex_unlock(&sysfs_bin_lock); | |
484 | } | |
485 | ||
1da177e4 LT |
486 | /** |
487 | * sysfs_create_bin_file - create binary file for object. | |
488 | * @kobj: object. | |
489 | * @attr: attribute descriptor. | |
1da177e4 LT |
490 | */ |
491 | ||
492 | int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) | |
493 | { | |
608e266a | 494 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 495 | |
608e266a | 496 | return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); |
1da177e4 LT |
497 | } |
498 | ||
499 | ||
500 | /** | |
501 | * sysfs_remove_bin_file - remove binary file for object. | |
502 | * @kobj: object. | |
503 | * @attr: attribute descriptor. | |
1da177e4 LT |
504 | */ |
505 | ||
995982ca | 506 | void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) |
1da177e4 | 507 | { |
5f1835da | 508 | sysfs_hash_and_remove(kobj->sd, attr->attr.name); |
1da177e4 LT |
509 | } |
510 | ||
511 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
512 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |