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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 <[email protected]> | |
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 | |
d5ce5b40 | 174 | kfree(temp); |
1da177e4 LT |
175 | return count; |
176 | } | |
177 | ||
e0edd3c6 EB |
178 | static void bin_vma_open(struct vm_area_struct *vma) |
179 | { | |
180 | struct file *file = vma->vm_file; | |
181 | struct bin_buffer *bb = file->private_data; | |
182 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
183 | ||
184 | if (!bb->vm_ops || !bb->vm_ops->open) | |
185 | return; | |
186 | ||
187 | if (!sysfs_get_active_two(attr_sd)) | |
188 | return; | |
189 | ||
190 | bb->vm_ops->open(vma); | |
191 | ||
192 | sysfs_put_active_two(attr_sd); | |
193 | } | |
194 | ||
195 | static void bin_vma_close(struct vm_area_struct *vma) | |
196 | { | |
197 | struct file *file = vma->vm_file; | |
198 | struct bin_buffer *bb = file->private_data; | |
199 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
200 | ||
201 | if (!bb->vm_ops || !bb->vm_ops->close) | |
202 | return; | |
203 | ||
204 | if (!sysfs_get_active_two(attr_sd)) | |
205 | return; | |
206 | ||
207 | bb->vm_ops->close(vma); | |
208 | ||
209 | sysfs_put_active_two(attr_sd); | |
210 | } | |
211 | ||
212 | static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
213 | { | |
214 | struct file *file = vma->vm_file; | |
215 | struct bin_buffer *bb = file->private_data; | |
216 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
217 | int ret; | |
218 | ||
219 | if (!bb->vm_ops || !bb->vm_ops->fault) | |
220 | return VM_FAULT_SIGBUS; | |
221 | ||
222 | if (!sysfs_get_active_two(attr_sd)) | |
223 | return VM_FAULT_SIGBUS; | |
224 | ||
225 | ret = bb->vm_ops->fault(vma, vmf); | |
226 | ||
227 | sysfs_put_active_two(attr_sd); | |
228 | return ret; | |
229 | } | |
230 | ||
851a039c | 231 | static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
e0edd3c6 EB |
232 | { |
233 | struct file *file = vma->vm_file; | |
234 | struct bin_buffer *bb = file->private_data; | |
235 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
236 | int ret; | |
237 | ||
095160ae | 238 | if (!bb->vm_ops) |
851a039c | 239 | return VM_FAULT_SIGBUS; |
e0edd3c6 | 240 | |
095160ae HD |
241 | if (!bb->vm_ops->page_mkwrite) |
242 | return 0; | |
243 | ||
e0edd3c6 | 244 | if (!sysfs_get_active_two(attr_sd)) |
851a039c | 245 | return VM_FAULT_SIGBUS; |
e0edd3c6 | 246 | |
851a039c | 247 | ret = bb->vm_ops->page_mkwrite(vma, vmf); |
e0edd3c6 EB |
248 | |
249 | sysfs_put_active_two(attr_sd); | |
250 | return ret; | |
251 | } | |
252 | ||
253 | static int bin_access(struct vm_area_struct *vma, unsigned long addr, | |
254 | void *buf, int len, int write) | |
255 | { | |
256 | struct file *file = vma->vm_file; | |
257 | struct bin_buffer *bb = file->private_data; | |
258 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
259 | int ret; | |
260 | ||
261 | if (!bb->vm_ops || !bb->vm_ops->access) | |
262 | return -EINVAL; | |
263 | ||
264 | if (!sysfs_get_active_two(attr_sd)) | |
265 | return -EINVAL; | |
266 | ||
267 | ret = bb->vm_ops->access(vma, addr, buf, len, write); | |
268 | ||
269 | sysfs_put_active_two(attr_sd); | |
270 | return ret; | |
271 | } | |
272 | ||
095160ae HD |
273 | #ifdef CONFIG_NUMA |
274 | static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) | |
275 | { | |
276 | struct file *file = vma->vm_file; | |
277 | struct bin_buffer *bb = file->private_data; | |
278 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
279 | int ret; | |
280 | ||
281 | if (!bb->vm_ops || !bb->vm_ops->set_policy) | |
282 | return 0; | |
283 | ||
284 | if (!sysfs_get_active_two(attr_sd)) | |
285 | return -EINVAL; | |
286 | ||
287 | ret = bb->vm_ops->set_policy(vma, new); | |
288 | ||
289 | sysfs_put_active_two(attr_sd); | |
290 | return ret; | |
291 | } | |
292 | ||
293 | static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, | |
294 | unsigned long addr) | |
295 | { | |
296 | struct file *file = vma->vm_file; | |
297 | struct bin_buffer *bb = file->private_data; | |
298 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
299 | struct mempolicy *pol; | |
300 | ||
301 | if (!bb->vm_ops || !bb->vm_ops->get_policy) | |
302 | return vma->vm_policy; | |
303 | ||
304 | if (!sysfs_get_active_two(attr_sd)) | |
305 | return vma->vm_policy; | |
306 | ||
307 | pol = bb->vm_ops->get_policy(vma, addr); | |
308 | ||
309 | sysfs_put_active_two(attr_sd); | |
310 | return pol; | |
311 | } | |
312 | ||
313 | static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, | |
314 | const nodemask_t *to, unsigned long flags) | |
315 | { | |
316 | struct file *file = vma->vm_file; | |
317 | struct bin_buffer *bb = file->private_data; | |
318 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; | |
319 | int ret; | |
320 | ||
321 | if (!bb->vm_ops || !bb->vm_ops->migrate) | |
322 | return 0; | |
323 | ||
324 | if (!sysfs_get_active_two(attr_sd)) | |
325 | return 0; | |
326 | ||
327 | ret = bb->vm_ops->migrate(vma, from, to, flags); | |
328 | ||
329 | sysfs_put_active_two(attr_sd); | |
330 | return ret; | |
331 | } | |
332 | #endif | |
333 | ||
e0edd3c6 EB |
334 | static struct vm_operations_struct bin_vm_ops = { |
335 | .open = bin_vma_open, | |
336 | .close = bin_vma_close, | |
337 | .fault = bin_fault, | |
338 | .page_mkwrite = bin_page_mkwrite, | |
339 | .access = bin_access, | |
095160ae HD |
340 | #ifdef CONFIG_NUMA |
341 | .set_policy = bin_set_policy, | |
342 | .get_policy = bin_get_policy, | |
343 | .migrate = bin_migrate, | |
344 | #endif | |
e0edd3c6 EB |
345 | }; |
346 | ||
1da177e4 LT |
347 | static int mmap(struct file *file, struct vm_area_struct *vma) |
348 | { | |
eb361653 | 349 | struct bin_buffer *bb = file->private_data; |
3e519038 | 350 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 TH |
351 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
352 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
eb361653 | 353 | int rc; |
1da177e4 | 354 | |
eb361653 | 355 | mutex_lock(&bb->mutex); |
0ab66088 TH |
356 | |
357 | /* need attr_sd for attr, its parent for kobj */ | |
e0edd3c6 | 358 | rc = -ENODEV; |
0ab66088 | 359 | if (!sysfs_get_active_two(attr_sd)) |
e0edd3c6 | 360 | goto out_unlock; |
0ab66088 TH |
361 | |
362 | rc = -EINVAL; | |
e0edd3c6 EB |
363 | if (!attr->mmap) |
364 | goto out_put; | |
0ab66088 | 365 | |
e0edd3c6 | 366 | rc = attr->mmap(kobj, attr, vma); |
e0edd3c6 EB |
367 | if (rc) |
368 | goto out_put; | |
0ab66088 | 369 | |
095160ae HD |
370 | /* |
371 | * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() | |
372 | * to satisfy versions of X which crash if the mmap fails: that | |
373 | * substitutes a new vm_file, and we don't then want bin_vm_ops. | |
374 | */ | |
375 | if (vma->vm_file != file) | |
e0edd3c6 EB |
376 | goto out_put; |
377 | ||
e0edd3c6 | 378 | rc = -EINVAL; |
095160ae | 379 | if (bb->mmapped && bb->vm_ops != vma->vm_ops) |
e0edd3c6 | 380 | goto out_put; |
e0edd3c6 EB |
381 | |
382 | rc = 0; | |
383 | bb->mmapped = 1; | |
095160ae HD |
384 | bb->vm_ops = vma->vm_ops; |
385 | vma->vm_ops = &bin_vm_ops; | |
e0edd3c6 EB |
386 | out_put: |
387 | sysfs_put_active_two(attr_sd); | |
388 | out_unlock: | |
eb361653 TH |
389 | mutex_unlock(&bb->mutex); |
390 | ||
391 | return rc; | |
1da177e4 LT |
392 | } |
393 | ||
394 | static int open(struct inode * inode, struct file * file) | |
395 | { | |
3e519038 | 396 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 | 397 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
eb361653 | 398 | struct bin_buffer *bb = NULL; |
0ab66088 | 399 | int error; |
1da177e4 | 400 | |
078ce640 TH |
401 | /* binary file operations requires both @sd and its parent */ |
402 | if (!sysfs_get_active_two(attr_sd)) | |
0ab66088 | 403 | return -ENODEV; |
1da177e4 | 404 | |
1da177e4 LT |
405 | error = -EACCES; |
406 | if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) | |
7b595756 | 407 | goto err_out; |
1da177e4 | 408 | if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) |
7b595756 | 409 | goto err_out; |
1da177e4 LT |
410 | |
411 | error = -ENOMEM; | |
eb361653 TH |
412 | bb = kzalloc(sizeof(*bb), GFP_KERNEL); |
413 | if (!bb) | |
7b595756 | 414 | goto err_out; |
1da177e4 | 415 | |
eb361653 TH |
416 | bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
417 | if (!bb->buffer) | |
7b595756 | 418 | goto err_out; |
eb361653 TH |
419 | |
420 | mutex_init(&bb->mutex); | |
e0edd3c6 | 421 | bb->file = file; |
eb361653 TH |
422 | file->private_data = bb; |
423 | ||
e0edd3c6 EB |
424 | mutex_lock(&sysfs_bin_lock); |
425 | hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers); | |
426 | mutex_unlock(&sysfs_bin_lock); | |
427 | ||
078ce640 TH |
428 | /* open succeeded, put active references */ |
429 | sysfs_put_active_two(attr_sd); | |
0ab66088 | 430 | return 0; |
1da177e4 | 431 | |
7b595756 | 432 | err_out: |
078ce640 | 433 | sysfs_put_active_two(attr_sd); |
0ab66088 | 434 | kfree(bb); |
1da177e4 LT |
435 | return error; |
436 | } | |
437 | ||
438 | static int release(struct inode * inode, struct file * file) | |
439 | { | |
eb361653 | 440 | struct bin_buffer *bb = file->private_data; |
1da177e4 | 441 | |
e0edd3c6 EB |
442 | mutex_lock(&sysfs_bin_lock); |
443 | hlist_del(&bb->list); | |
444 | mutex_unlock(&sysfs_bin_lock); | |
445 | ||
eb361653 TH |
446 | kfree(bb->buffer); |
447 | kfree(bb); | |
1da177e4 LT |
448 | return 0; |
449 | } | |
450 | ||
4b6f5d20 | 451 | const struct file_operations bin_fops = { |
1da177e4 LT |
452 | .read = read, |
453 | .write = write, | |
454 | .mmap = mmap, | |
455 | .llseek = generic_file_llseek, | |
456 | .open = open, | |
457 | .release = release, | |
458 | }; | |
459 | ||
e0edd3c6 EB |
460 | |
461 | void unmap_bin_file(struct sysfs_dirent *attr_sd) | |
462 | { | |
463 | struct bin_buffer *bb; | |
464 | struct hlist_node *tmp; | |
465 | ||
466 | if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR) | |
467 | return; | |
468 | ||
469 | mutex_lock(&sysfs_bin_lock); | |
470 | ||
471 | hlist_for_each_entry(bb, tmp, &attr_sd->s_bin_attr.buffers, list) { | |
472 | struct inode *inode = bb->file->f_path.dentry->d_inode; | |
473 | ||
474 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
475 | } | |
476 | ||
477 | mutex_unlock(&sysfs_bin_lock); | |
478 | } | |
479 | ||
1da177e4 LT |
480 | /** |
481 | * sysfs_create_bin_file - create binary file for object. | |
482 | * @kobj: object. | |
483 | * @attr: attribute descriptor. | |
1da177e4 LT |
484 | */ |
485 | ||
486 | int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) | |
487 | { | |
608e266a | 488 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 489 | |
608e266a | 490 | return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); |
1da177e4 LT |
491 | } |
492 | ||
493 | ||
494 | /** | |
495 | * sysfs_remove_bin_file - remove binary file for object. | |
496 | * @kobj: object. | |
497 | * @attr: attribute descriptor. | |
1da177e4 LT |
498 | */ |
499 | ||
995982ca | 500 | void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) |
1da177e4 | 501 | { |
5f1835da | 502 | sysfs_hash_and_remove(kobj->sd, attr->attr.name); |
1da177e4 LT |
503 | } |
504 | ||
505 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
506 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |