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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 | ||
1c8542c7 LZ |
160 | temp = memdup_user(userbuf, count); |
161 | if (IS_ERR(temp)) | |
162 | return PTR_ERR(temp); | |
1da177e4 | 163 | |
b31ca3f5 NP |
164 | mutex_lock(&bb->mutex); |
165 | ||
166 | memcpy(bb->buffer, temp, count); | |
167 | ||
eb361653 | 168 | count = flush_write(dentry, bb->buffer, offs, count); |
b31ca3f5 NP |
169 | mutex_unlock(&bb->mutex); |
170 | ||
1da177e4 LT |
171 | if (count > 0) |
172 | *off = offs + count; | |
eb361653 | 173 | |
1da177e4 LT |
174 | return count; |
175 | } | |
176 | ||
e0edd3c6 EB |
177 | static void bin_vma_open(struct vm_area_struct *vma) |
178 | { | |
179 | struct file *file = vma->vm_file; | |
180 | struct bin_buffer *bb = file->private_data; | |
181 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
182 | ||
183 | if (!bb->vm_ops || !bb->vm_ops->open) | |
184 | return; | |
185 | ||
186 | if (!sysfs_get_active_two(attr_sd)) | |
187 | return; | |
188 | ||
189 | bb->vm_ops->open(vma); | |
190 | ||
191 | sysfs_put_active_two(attr_sd); | |
192 | } | |
193 | ||
194 | static void bin_vma_close(struct vm_area_struct *vma) | |
195 | { | |
196 | struct file *file = vma->vm_file; | |
197 | struct bin_buffer *bb = file->private_data; | |
198 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
199 | ||
200 | if (!bb->vm_ops || !bb->vm_ops->close) | |
201 | return; | |
202 | ||
203 | if (!sysfs_get_active_two(attr_sd)) | |
204 | return; | |
205 | ||
206 | bb->vm_ops->close(vma); | |
207 | ||
208 | sysfs_put_active_two(attr_sd); | |
209 | } | |
210 | ||
211 | static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
212 | { | |
213 | struct file *file = vma->vm_file; | |
214 | struct bin_buffer *bb = file->private_data; | |
215 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
216 | int ret; | |
217 | ||
218 | if (!bb->vm_ops || !bb->vm_ops->fault) | |
219 | return VM_FAULT_SIGBUS; | |
220 | ||
221 | if (!sysfs_get_active_two(attr_sd)) | |
222 | return VM_FAULT_SIGBUS; | |
223 | ||
224 | ret = bb->vm_ops->fault(vma, vmf); | |
225 | ||
226 | sysfs_put_active_two(attr_sd); | |
227 | return ret; | |
228 | } | |
229 | ||
851a039c | 230 | static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
e0edd3c6 EB |
231 | { |
232 | struct file *file = vma->vm_file; | |
233 | struct bin_buffer *bb = file->private_data; | |
234 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
235 | int ret; | |
236 | ||
095160ae | 237 | if (!bb->vm_ops) |
851a039c | 238 | return VM_FAULT_SIGBUS; |
e0edd3c6 | 239 | |
095160ae HD |
240 | if (!bb->vm_ops->page_mkwrite) |
241 | return 0; | |
242 | ||
e0edd3c6 | 243 | if (!sysfs_get_active_two(attr_sd)) |
851a039c | 244 | return VM_FAULT_SIGBUS; |
e0edd3c6 | 245 | |
851a039c | 246 | ret = bb->vm_ops->page_mkwrite(vma, vmf); |
e0edd3c6 EB |
247 | |
248 | sysfs_put_active_two(attr_sd); | |
249 | return ret; | |
250 | } | |
251 | ||
252 | static int bin_access(struct vm_area_struct *vma, unsigned long addr, | |
253 | void *buf, int len, int write) | |
254 | { | |
255 | struct file *file = vma->vm_file; | |
256 | struct bin_buffer *bb = file->private_data; | |
257 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
258 | int ret; | |
259 | ||
260 | if (!bb->vm_ops || !bb->vm_ops->access) | |
261 | return -EINVAL; | |
262 | ||
263 | if (!sysfs_get_active_two(attr_sd)) | |
264 | return -EINVAL; | |
265 | ||
266 | ret = bb->vm_ops->access(vma, addr, buf, len, write); | |
267 | ||
268 | sysfs_put_active_two(attr_sd); | |
269 | return ret; | |
270 | } | |
271 | ||
095160ae HD |
272 | #ifdef CONFIG_NUMA |
273 | static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) | |
274 | { | |
275 | struct file *file = vma->vm_file; | |
276 | struct bin_buffer *bb = file->private_data; | |
277 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
278 | int ret; | |
279 | ||
280 | if (!bb->vm_ops || !bb->vm_ops->set_policy) | |
281 | return 0; | |
282 | ||
283 | if (!sysfs_get_active_two(attr_sd)) | |
284 | return -EINVAL; | |
285 | ||
286 | ret = bb->vm_ops->set_policy(vma, new); | |
287 | ||
288 | sysfs_put_active_two(attr_sd); | |
289 | return ret; | |
290 | } | |
291 | ||
292 | static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, | |
293 | unsigned long addr) | |
294 | { | |
295 | struct file *file = vma->vm_file; | |
296 | struct bin_buffer *bb = file->private_data; | |
297 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
298 | struct mempolicy *pol; | |
299 | ||
300 | if (!bb->vm_ops || !bb->vm_ops->get_policy) | |
301 | return vma->vm_policy; | |
302 | ||
303 | if (!sysfs_get_active_two(attr_sd)) | |
304 | return vma->vm_policy; | |
305 | ||
306 | pol = bb->vm_ops->get_policy(vma, addr); | |
307 | ||
308 | sysfs_put_active_two(attr_sd); | |
309 | return pol; | |
310 | } | |
311 | ||
312 | static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, | |
313 | const nodemask_t *to, unsigned long flags) | |
314 | { | |
315 | struct file *file = vma->vm_file; | |
316 | struct bin_buffer *bb = file->private_data; | |
317 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
318 | int ret; | |
319 | ||
320 | if (!bb->vm_ops || !bb->vm_ops->migrate) | |
321 | return 0; | |
322 | ||
323 | if (!sysfs_get_active_two(attr_sd)) | |
324 | return 0; | |
325 | ||
326 | ret = bb->vm_ops->migrate(vma, from, to, flags); | |
327 | ||
328 | sysfs_put_active_two(attr_sd); | |
329 | return ret; | |
330 | } | |
331 | #endif | |
332 | ||
e0edd3c6 EB |
333 | static struct vm_operations_struct bin_vm_ops = { |
334 | .open = bin_vma_open, | |
335 | .close = bin_vma_close, | |
336 | .fault = bin_fault, | |
337 | .page_mkwrite = bin_page_mkwrite, | |
338 | .access = bin_access, | |
095160ae HD |
339 | #ifdef CONFIG_NUMA |
340 | .set_policy = bin_set_policy, | |
341 | .get_policy = bin_get_policy, | |
342 | .migrate = bin_migrate, | |
343 | #endif | |
e0edd3c6 EB |
344 | }; |
345 | ||
1da177e4 LT |
346 | static int mmap(struct file *file, struct vm_area_struct *vma) |
347 | { | |
eb361653 | 348 | struct bin_buffer *bb = file->private_data; |
3e519038 | 349 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 TH |
350 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
351 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
eb361653 | 352 | int rc; |
1da177e4 | 353 | |
eb361653 | 354 | mutex_lock(&bb->mutex); |
0ab66088 TH |
355 | |
356 | /* need attr_sd for attr, its parent for kobj */ | |
e0edd3c6 | 357 | rc = -ENODEV; |
0ab66088 | 358 | if (!sysfs_get_active_two(attr_sd)) |
e0edd3c6 | 359 | goto out_unlock; |
0ab66088 TH |
360 | |
361 | rc = -EINVAL; | |
e0edd3c6 EB |
362 | if (!attr->mmap) |
363 | goto out_put; | |
0ab66088 | 364 | |
e0edd3c6 | 365 | rc = attr->mmap(kobj, attr, vma); |
e0edd3c6 EB |
366 | if (rc) |
367 | goto out_put; | |
0ab66088 | 368 | |
095160ae HD |
369 | /* |
370 | * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() | |
371 | * to satisfy versions of X which crash if the mmap fails: that | |
372 | * substitutes a new vm_file, and we don't then want bin_vm_ops. | |
373 | */ | |
374 | if (vma->vm_file != file) | |
e0edd3c6 EB |
375 | goto out_put; |
376 | ||
e0edd3c6 | 377 | rc = -EINVAL; |
095160ae | 378 | if (bb->mmapped && bb->vm_ops != vma->vm_ops) |
e0edd3c6 | 379 | goto out_put; |
e0edd3c6 EB |
380 | |
381 | rc = 0; | |
382 | bb->mmapped = 1; | |
095160ae HD |
383 | bb->vm_ops = vma->vm_ops; |
384 | vma->vm_ops = &bin_vm_ops; | |
e0edd3c6 EB |
385 | out_put: |
386 | sysfs_put_active_two(attr_sd); | |
387 | out_unlock: | |
eb361653 TH |
388 | mutex_unlock(&bb->mutex); |
389 | ||
390 | return rc; | |
1da177e4 LT |
391 | } |
392 | ||
393 | static int open(struct inode * inode, struct file * file) | |
394 | { | |
3e519038 | 395 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 | 396 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
eb361653 | 397 | struct bin_buffer *bb = NULL; |
0ab66088 | 398 | int error; |
1da177e4 | 399 | |
078ce640 TH |
400 | /* binary file operations requires both @sd and its parent */ |
401 | if (!sysfs_get_active_two(attr_sd)) | |
0ab66088 | 402 | return -ENODEV; |
1da177e4 | 403 | |
1da177e4 LT |
404 | error = -EACCES; |
405 | if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) | |
7b595756 | 406 | goto err_out; |
1da177e4 | 407 | if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) |
7b595756 | 408 | goto err_out; |
1da177e4 LT |
409 | |
410 | error = -ENOMEM; | |
eb361653 TH |
411 | bb = kzalloc(sizeof(*bb), GFP_KERNEL); |
412 | if (!bb) | |
7b595756 | 413 | goto err_out; |
1da177e4 | 414 | |
eb361653 TH |
415 | bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
416 | if (!bb->buffer) | |
7b595756 | 417 | goto err_out; |
eb361653 TH |
418 | |
419 | mutex_init(&bb->mutex); | |
e0edd3c6 | 420 | bb->file = file; |
eb361653 TH |
421 | file->private_data = bb; |
422 | ||
e0edd3c6 EB |
423 | mutex_lock(&sysfs_bin_lock); |
424 | hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers); | |
425 | mutex_unlock(&sysfs_bin_lock); | |
426 | ||
078ce640 TH |
427 | /* open succeeded, put active references */ |
428 | sysfs_put_active_two(attr_sd); | |
0ab66088 | 429 | return 0; |
1da177e4 | 430 | |
7b595756 | 431 | err_out: |
078ce640 | 432 | sysfs_put_active_two(attr_sd); |
0ab66088 | 433 | kfree(bb); |
1da177e4 LT |
434 | return error; |
435 | } | |
436 | ||
437 | static int release(struct inode * inode, struct file * file) | |
438 | { | |
eb361653 | 439 | struct bin_buffer *bb = file->private_data; |
1da177e4 | 440 | |
e0edd3c6 EB |
441 | mutex_lock(&sysfs_bin_lock); |
442 | hlist_del(&bb->list); | |
443 | mutex_unlock(&sysfs_bin_lock); | |
444 | ||
eb361653 TH |
445 | kfree(bb->buffer); |
446 | kfree(bb); | |
1da177e4 LT |
447 | return 0; |
448 | } | |
449 | ||
4b6f5d20 | 450 | const struct file_operations bin_fops = { |
1da177e4 LT |
451 | .read = read, |
452 | .write = write, | |
453 | .mmap = mmap, | |
454 | .llseek = generic_file_llseek, | |
455 | .open = open, | |
456 | .release = release, | |
457 | }; | |
458 | ||
e0edd3c6 EB |
459 | |
460 | void unmap_bin_file(struct sysfs_dirent *attr_sd) | |
461 | { | |
462 | struct bin_buffer *bb; | |
463 | struct hlist_node *tmp; | |
464 | ||
465 | if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR) | |
466 | return; | |
467 | ||
468 | mutex_lock(&sysfs_bin_lock); | |
469 | ||
470 | hlist_for_each_entry(bb, tmp, &attr_sd->s_bin_attr.buffers, list) { | |
471 | struct inode *inode = bb->file->f_path.dentry->d_inode; | |
472 | ||
473 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
474 | } | |
475 | ||
476 | mutex_unlock(&sysfs_bin_lock); | |
477 | } | |
478 | ||
1da177e4 LT |
479 | /** |
480 | * sysfs_create_bin_file - create binary file for object. | |
481 | * @kobj: object. | |
482 | * @attr: attribute descriptor. | |
1da177e4 LT |
483 | */ |
484 | ||
485 | int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) | |
486 | { | |
608e266a | 487 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 488 | |
608e266a | 489 | return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); |
1da177e4 LT |
490 | } |
491 | ||
492 | ||
493 | /** | |
494 | * sysfs_remove_bin_file - remove binary file for object. | |
495 | * @kobj: object. | |
496 | * @attr: attribute descriptor. | |
1da177e4 LT |
497 | */ |
498 | ||
995982ca | 499 | void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) |
1da177e4 | 500 | { |
5f1835da | 501 | sysfs_hash_and_remove(kobj->sd, attr->attr.name); |
1da177e4 LT |
502 | } |
503 | ||
504 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
505 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |